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  • Hjelm, Olof
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Industriell miljöteknik. Linköpings universitet, Tekniska fakulteten.
    Halvarsson Lundqvist, Agneta
    Linköpings universitet, Institutionen för beteendevetenskap och lärande, Pedagogik och sociologi. Linköpings universitet, Filosofiska fakulteten.
    Eklund, Jörgen
    Kungliga Tekniska Högskolan, Stockholm.
    Kambanou, Marianna Lena
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Industriell miljöteknik. Linköpings universitet, Tekniska fakulteten.
    Spyrou, Eleftherios
    Grön omställning i svenska små och medelstora industriföretag: Åtta strategier för ett verkningsfullt stödsystem2025Rapport (Annet vitenskapelig)
    Abstract [sv]

    I detta Vinnovafinansierade forskningsprojekt, Interaktiv forskning för grön omställning, IFGO, har vi undersökt hur små och medelstora industriföretag (SMF) kan stöttas i sin gröna omställning för ökad resurseffektivitet, minskad klimatpåverkan och ökad konkurrenskraft. Forskningsprojektet genomfördes av Linköpings universitet under perioden september 2021 – december 2024. Projektet omfattar en förstudie och fyra efterföljande fördjupande delstudier som fokuserade olika aktörer som stöttar SMF (rapporteras i bilaga 1–5 i denna rapport). Samhällspolicyer på nationell och internationell nivå har ökat förväntningarna att näringslivet aktivt ska bidra till att lösa miljö- och hållbarhetsutmaningar. Många aktörer inklusive forskningsfinansiärer vill öka farten i denna gröna omställning. För att stötta SMF har ett stödsystem vuxit fram bestående av aktörer som på olika sätt hjälper företag och entreprenörer i deras omställningsarbete. Ett stödsystem kan definieras som ”alla aktörer, institutionella miljöer och resurser som hjälper entreprenörer att arbeta framgångsrikt med innovation och utveckling”. Några aktörer verkar på en övergripande nivå, andra främst regionalt eller lokalt. Rapporten fokuserar aktörer som är offentligt ägda eller delvis finansierade av offentliga medel. 

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  • Bössa, Clara
    et al.
    Linköpings universitet, Institutionen för beteendevetenskap och lärande. Linköpings universitet, Utbildningsvetenskap.
    Melchersson, Maja
    Linköpings universitet, Institutionen för beteendevetenskap och lärande. Linköpings universitet, Utbildningsvetenskap.
    Viktiga vär(l)den: LIU-FG1-3-N-G--25/07--SE2025Independent thesis Basic level (professional degree), 10 poäng / 15 hpOppgave
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  • Syssner, Josefina
    Linköpings universitet, Institutionen för kultur och samhälle, Centrum för kommunstrategiska studier. Linköpings universitet, Filosofiska fakulteten.
    Geografens guide till glesbygden2025Bok (Annet (populærvitenskap, debatt, mm))
    Abstract [sv]

    Min forskning handlar om lokal utveckling, politik och planering i områden som har ett vikande befolkningsunderlag, en svag ekonomi och som ligger långt ifrån de stora tillväxtnoderna. Ibland kallas sådana områden för glesbygd, landsbygd eller för krympande geografier. Ibland kallas de perifera, ibland för eftersatta, ibland för platser med geografiska lägesnackdelar. Min forskning handlar om hur det är att leva och verka på sådana platser. Den handlar om hur det är att vara kommunpolitiker eller att jobba i den kommunala förvaltningen där. Vad kan kommunerna göra för att få den lokala demokratin, beslutsfattandet, planeringen, verksamheten och utvecklingen att fungera även om man har lite uppförsbacke?

    Syftet med min text är att synliggöra forskningens betydelse för dessa platser och för de som lever och verkar där. Men innan jag fördjupar mig i den uppgiften vill jag diskutera forskningens betydelse i samhället mer generellt.

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  • Navisotschnig, Genevieve
    Linköpings universitet, Institutionen för beteendevetenskap och lärande.
    Teaching and Learning in Higher Education Intercultural Classrooms:: Educators’ Perspective on Classroom Challenges & Solutions Towards Inclusive Practice2024Independent thesis Advanced level (degree of Master (Two Years)), 10 poäng / 15 hpOppgave
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  • Grujicic, Danijel
    Linköpings universitet, Institutionen för datavetenskap, Programvara och system.
    Automated Parameter Tuning of Finance Surveillance Frameworks Using Mixed-Variable Differential Evolution: An Implementation of a Black-Box Optimization Strategy2025Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    The challenges of parameter optimization can be complex and require custom-made solutions for a specific problem. One such issue is within market surveillance frameworks. Market surveillance frameworks are tools for detecting potentially illegal market activity by analyzing stock market data. However, their detection functions called alert rules, use varying amounts of parameters that require time-consuming tuning, the work aims to develop an automated method for adjusting unique sets of parameters belonging to alert rules which detect suspicious activity in various financial marketplaces. This is to achieve a desired number of triggered alerts, to save time and therefore also resources when tuning. This thesis explores the approach of using Differential Evolution, a black-box optimization algorithm that has been successful in solving optimization tasks, to solve this problem. The thesis also looks into the key features of anomaly detection in surveillance frameworks and evaluates the effectiveness of implementing the Differential Evolution algorithm with mixed-variable handling. Differential Evolution will be assessed on convergence speed and fitness score with regard to data set size. By identifying an effective hyperparameter configuration for the algorithm, this research aims to contribute to improved market surveillance and thus also to a more transparent financial market. This thesis has been conducted in collaboration with the company Scila which specializes in market surveillance. The results show that a more exploitive approach is beneficial for the Differential evolution algorithm when optimizing the alert rule parameters. Mutation factors F ď 0.5 consistently displayed better mean fitness across generations, faster convergence, and better best solutions close to the desired target number of alerts. The proposed implementation was therefore successful in optimizing the problem’s objective function contributing to the development of tools that could enable a more transparent and even financial market for its participants while simultaneously aiding authorities in surveilling the aforementioned market by potentially decreasing the time requirement of manually tuning alert rules within a finance surveillance framework.

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  • Disputas: 2025-06-13 09:15 Schrödinger (E324), Fysikhuset, LinköpingBestill onlineKjøp publikasjonen >>
    Van Poucke, Enya
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    Breaking the Shell of Stress: Buffering Early Stress in Commercially Hatched Laying Hens2025Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Approximately eight billion laying hens currently support the global demand for eggs. To sustain this growing worldwide commercial demand, a continuous supply of laying hens in their peak production stage is required. These hens begin their lives in large-scale commercial hatcheries, where, as newly hatched chicks, they undergo a highly efficient industrial process. Shortly after hatching in large incubators, chicks are transferred onto a conveyor belt system that moves them through several stations, each handling a specific task: separation from the eggshell, sex-sorting, vaccination, and machine-packing for transportation to the rearing farm. This process has previously been shown to elicit a stress response with both short- and long-term effects on behaviour, physiology, and affective states, which could lead to future welfare issues. The primary focus of this thesis revolves around mitigating the stress chicks have incurred at the commercial hatchery upon hatching.

    In paper I, we enriched chicks by providing them with a more complex environment and a stuffed mother hen on which the chicks were imprinted. Among hatchery-hatched chicks, those provided with enrichment exhibited a reduced stress response to a restraint; however, no other effects of enrichment were found. Overall, hatchery chicks showed more pessimism and higher stress levels when socially isolated, which is consistent with previous studies indicating that the commercial hatching conditions are stressful.

    Similarly, in paper II, we investigated whether enriching the early environment with natural-like elements could buffer hatchery stress. Enriched chicks completed a spatial memory test more quickly while making less immediate errors, were more optimistic in a cognitive judgment bias test, and had fewer feather fault bars, which indicate lower levels of acute stress. We concluded that the provided naturalistic enrichment helped reduce early stress and improved welfare.

    In paper III, we explored whether stimulating play behaviours in an arena with objects during the first weeks of life could buffer early stress sustained during the commercial hatching process. Play-stimulated chicks exhibited reduced fear in response to a novel object; however, contrary to our expectations, they also showed more pessimism in a cognitive bias test. No effects of play were observed in the other assays. Our results suggest that play stimulation can help chicks tackle future challenges, but its impact on emotional states requires further research.

    In the final paper, paper IV, we examined how the commercial hatchery process affected stress events that occur at later stages in a laying hen’s life, such as transportation and introductions to novel environments and new social groups. Control chicks exhibited reduced tonic immobility durations following transportation. Comb temperatures of hatchery-hatched chicks indicated both stress-induced hyperthermia after a regrouping procedure and a stronger autonomic response to an acute stressor. This demonstrates the long-lasting effects of commercial hatching on the hens’ abilities to cope with routine events encountered in rearing environments.

    In summary, these findings further illustrate the negative impact commercial hatching procedures have on both the stress response and welfare of laying hens, even affecting their ability to cope with stressors encountered later in life. Fortunately, enriching chicks’ lives with more complex environments and providing opportunities to enhance play can moderate stress sensitivity, reduce fearfulness, and improve positive affective states which in turn enhances welfare outcomes. Together, these papers bring support to the need to refine the early-life environments of hens to help buffer stress and in turn improve their long-term welfare.

    Delarbeid
    1. Can Early Environmental Enrichment Buffer Stress from Commercial Hatchery Processing in Laying Hens?
    Åpne denne publikasjonen i ny fane eller vindu >>Can Early Environmental Enrichment Buffer Stress from Commercial Hatchery Processing in Laying Hens?
    2022 (engelsk)Inngår i: Poultry, E-ISSN 2674-1164, Vol. 1, nr 2, s. 125-137Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Under commercial conditions, laying hen chicks are exposed to a range of stressful events immediately after hatch. Here, we studied whether environmental enrichment was able to reduce the stress sensitivity of these chicks. A total of 50 hatchery chicks (HC) and 50 control chicks (CC) were raised in enriched pens (E), while 53 HC + 53 CC were raised in standard non-enriched floor pens (NE). HC weighed less on day one, but there was no effect of hatchery treatment at later ages. HC were more pessimistic in a cognitive judgement bias test and emitted more distress calls when socially isolated, indicating that hatchery stress affected behaviour and stress sensitivity. However, enrichment did not affect the behaviour in any of these tests. We found no effects of hatchery stress in a novel environment, but indications that enrichment may have increased fearfulness of HC. The sensitivity of the hypothalamic-pituitary-adrenal (HPA) axis was reduced in HC-E compared to HC-NE, indicating that enrichment buffered the physiological stress sensitivity in HC; however, the opposite pattern was found in CC. In conclusion, our results show complex and somewhat contradictory effects on the ability of enrichment to buffer the consequences of stress in commercial hatcheries.

    sted, utgiver, år, opplag, sider
    MDPI, 2022
    Emneord
    hatchery stress; white leghorn; enrichment; corticosterone; behaviour; early stress
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-188040 (URN)10.3390/poultry1020011 (DOI)001353115500001 ()
    Forskningsfinansiär
    Swedish Research Council Formas, 2016-01728Swedish Research Council Formas, 2019-02084
    Tilgjengelig fra: 2022-09-02 Laget: 2022-09-02 Sist oppdatert: 2025-05-09
    2. Play stimulation as a possible means to buffer early stress from commercial hatchery treatment in laying hen chicks
    Åpne denne publikasjonen i ny fane eller vindu >>Play stimulation as a possible means to buffer early stress from commercial hatchery treatment in laying hen chicks
    2024 (engelsk)Inngår i: Applied Animal Behaviour Science, ISSN 0168-1591, E-ISSN 1872-9045, Vol. 274, artikkel-id 106264Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    In commercial hatcheries, laying hen chicks are exposed to a range of stressors that have previously been shown to induce long-term negative effects on their welfare. It has been suggested that stimulation of play behaviour, a self-rewarding activity associated with positive emotions, may be a way to improve animal welfare. We have previously found that chicks play extensively during their first weeks of life if offered the possibility. Our hypothesis was therefore that stimulating play in chicks could buffer the long-term consequences of stress from commercial hatchery routines. Sixty female Lohmann LSL chicks were hatched at a commercial hatchery and transported for four hours before being randomly allocated to two different treatments. Play-stimulated chicks (PC) were taken out of the home pens and introduced in groups of five into a spacious, object-enriched play arena 3x30 min per week for five weeks starting from 9 days of age. Control chicks (CC) were taken out of the home pens at the same time as PC and placed in cardboard boxes for the same amount of time as PC were allowed to play. Between 46 and 57 days of age,behavioural and corticosterone reactivity tests were conducted. There were no differences between the treatment groups in open field activity, but in a novel object test PC were more active and interacted more with the novel object, indicating reduced fear. There were no differences between the treatment groups in duration of tonic immobility or in corticosterone reaction to a brief restraint. Contrary to our predictions, PC showed a more negative bias compared to CC in a cognitive judgement bias test. In conclusion, play stimulation may reduce fearfulness in early-stressed chickens, but the reason for the opposite reaction in the cognitive judgement bias needs further investigation.

    sted, utgiver, år, opplag, sider
    ELSEVIER, 2024
    Emneord
    Early stress; Hatchery stress; Play; Stimulation; Fear; Cognitive judgement bias
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-204358 (URN)10.1016/j.applanim.2024.106264 (DOI)001233668100001 ()
    Merknad

    Funding Agencies|Swedish Research Agency Formas [2019-02084]

    Tilgjengelig fra: 2024-06-12 Laget: 2024-06-12 Sist oppdatert: 2025-05-09
    3. Commercial hatchery processing may affect susceptibility to stress in laying hens
    Åpne denne publikasjonen i ny fane eller vindu >>Commercial hatchery processing may affect susceptibility to stress in laying hens
    2023 (engelsk)Inngår i: PLOS ONE, E-ISSN 1932-6203, Vol. 18, nr 9, artikkel-id e0291324Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Directly upon hatching, laying hen chicks are exposed to multiple stressful events during large-scale hatchery processing, which may affect their later coping abilities. Commercial hatchery chicks (HC) were compared to chicks that were incubated and hatched simultaneously under calm conditions (CC). After being raised under similar, non-stressful conditions for 36 days, all chicks were exposed to a series of stressors: transportation and introduction into a novel environment followed by a regrouping event in order to characterize long-lasting consequences of hatchery treatment. Tonic immobility, corticosterone levels, and peripheral body temperature were used to assess reactions to the stress events. Tonic immobility was not affected by treatment but was significantly reduced in CC after transport. Corticosterone levels did not differ between treatments when assessed two days before and two days after regrouping. Comb temperature was significantly higher in HC following regrouping, indicating stress-induced hyperthermia. Furthermore, comb temperature dropped more following blood sampling in HC than in CC, indicating a stronger autonomic response to acute stress. In conclusion, the results suggest possible long-term negative effects of commercial hatchery processing, compared to hatching under silent and less stressful conditions, on the coping ability of laying hens to later stressful experiences.

    sted, utgiver, år, opplag, sider
    PUBLIC LIBRARY SCIENCE, 2023
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-198679 (URN)10.1371/journal.pone.0291324 (DOI)001066971400011 ()37695788 (PubMedID)
    Merknad

    Funding Agencies|We thank Lohmann Sverige AB for collaboration and the CBR technicians for their animal care.; Lohmann Sverige AB

    Tilgjengelig fra: 2023-10-24 Laget: 2023-10-24 Sist oppdatert: 2025-05-09
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  • Pantic-Dragisic, Svjetlana
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Företagsekonomi. Linköpings universitet, Filosofiska fakulteten.
    Pemer, Frida
    Handelshögskolan i Stockholm.
    Populärvetenskaplig rapport: Att leda och samarbeta i team på distans - effekter av Covid-19 i projektbaserade organisationer2025Rapport (Annet (populærvitenskap, debatt, mm))
    Abstract [sv]

    Denna rapport är en sammanfattning av de huvudresultat och praktiska implikationer från forskningsprojektet ”Att leda och samarbeta i team på distans - effekter av Covid-19 i projektbaserade organisationer” (200 354). Projektet har finansierats av AFA Försäkring och har pågått 2021–2024.

    COVID-19 pandemin föranledde många organisationer att övergå till att arbeta i hybridformat. Denna övergång blev särskilt kännbar i projektbaserade kunskapsintensiva företag, som bygger på att medarbetarna samarbetar i team. Teamen är centrala för innovation, upplärning och kompetensutveckling, och utgör grunden för företagens fortlevnad. Projektet undersöker vilka konsekvenser övergången till hybridarbete får för hur teamen samarbetar, organiserar sitt arbete, och leds.

    Projektet syftar till att utvinna ny teoretiskt och praktiskt relevant kunskap om hur samarbete och teamkänsla i projektbaserade kunskapsintensiva företag påverkas av att arbetet utförs via digitala verktyg istället för i fysisk närhet. Vi studerar hur arbetet organiseras och leds, hur rekrytering och insocialisering av nya medlemmar sker, hur teamen arbetar med kunskapsutveckling, lärande och innovation, samt hur känslan av tillhörighet påverkas av att arbeta på distans via digitala verktyg.

    Vi har genomfört en kvalitativ flerfallsstudie av åtta konsultbolag inom management/strategi, teknik/IT, policy och HR, vilket genererat 65 intervjuer med konsulter i olika roller. Intervjuerna har givit nya insikter hur övergången till hybridarbete påverkar hur arbetet organiseras och leds, samt för kunskapsutveckling och innovation. Observationer har utförts på workshops och strategidagar i ett av fallföretagen. Vi har även samlat in dokument om processer, policies, etc, från fallföretagen.

    Våra resultat visar att hybridarbete skapar spänningar och stress hos kunskapsarbetare, vilket gör det svårt att utveckla en tydlig professionell identitet. Organisationer som använder lärlingsmodellen är särskilt sårbara, då juniora medarbetare behöver mer vägledning från seniora kollegor. Hybridarbete påverkar också ledar- och följarrelationer, där digitala verktyg ersätter fysisk närhet och förändrar hur identiteter och tillhörighet konstrueras. Pandemin har dessutom skapat utmaningar för teamarbete, med både fördelar och nackdelar för distansarbete, och har påverkat socialiseringen av nyanställda negativt.

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  • Larsson, William
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Mekanik och hållfasthetslära.
    Nordahl, Johan
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Mekanik och hållfasthetslära.
    Predictions of Vibrations in Aircraft Structure: Random Response Analysis of a Conceptual Aircraft Subject to Sound Pressure from Flow Over an Internal Weapon Bay2024Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Vibration is a vital field in physics, especially within the aeronautical industry, where precise vibration prediction is crucial to prevent structural failures and equipment damage. During the conceptual phase of aircraft design, the prediction of the vibrational environment is highly valu-able. This thesis examines the vibrational environment in an aircraft structure subjected to cavity oscillations caused by an internal weapon bay. The study uses the ESDU 18011 standard to model a continuous non-deterministic excitation resulting from these oscillations. The aims are to in-vestigate the necessary model fidelity to accurately capture the vibrational environment in the frequency range, to model and install damping mats to investigate the influence on the dynamical behaviour, and to examine the effect of equipment mounting on local vibration responses. The methodology begins with designing the downstream wall of the internal weapon bay to withstand fatigue and resonance due to increased sound pressure. This redesigned wall is then incorporated into the aircraft structure. Structural fidelity is assessed by implementing reinforcements, point masses, and fuel. The effects of damping mats on the vibrational environment are evaluated by modelling and mounting them. Furthermore, the study analyses the local impact of the mount-ing of the equipment on vibrations. The results show that high model fidelity is crucial near the internal weapon bay, a dense mesh is required to accurately capture the wave propagation for higher frequencies, damping mats influence the dynamic behaviour, and equipment mounting substantially decreases local vibrational amplitudes.

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  • Ahlén Rashid, Natalie
    Linköpings universitet, Institutionen för hälsa, medicin och vård.
    När ingen lyssnar, stödet brister och jobb saknas blir spelvärlden en fristad: en studie om unga vuxna med kognitiv funktionsnedsättning2024Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [sv]

    Forskning har visat att unga vuxna med kognitiv funktionsnedsättning ofta har digitala spel som intresse samtidigt som de löper hög risk för socialt utanförskap med begränsade möjligheter att påverka insatser som berör dem. Fler studier som utgår från personer med kognitiv funktionsnedsättnings perspektiv behövs.

    Syftet med studien är att utforska aktivitetsrepertoar och upplevelse av digitala spel hos unga vuxna gamers med kognitiv funktionsnedsättning, samt att undersöka deras upplevda möjligheter och hinder till arbete eller annan sysselsättning och värde av att ha ett arbete.

    Studien bygger på sekundärdata. Genom ett strategiskt urval rekryterades 10 personer med kognitiv funktionsnedsättning i åldern 20 till 31 med ett självupplevt stort intresse för digitala spel och berättigade sysselsättning via LSS eller SoL. All data samlades in av forskargruppen under sommaren, hösten och vintern 2021 genom individuella intervjuer och fokusgruppsdiskussioner. I uppsatsen genomfördes en reflexiv tematisk analys av kvalitativa data som inte tidigare analyserats. Det gjordes även en deskriptiv sammanfattning av kvantitativa data som forskargruppen samlade in med instrumentet COPM i samband med intervjuer. 

    Resultatet visade att deltagarnas aktivitetsrepertoar dominerades av fritid och centrerade runt digitala spel som möjliggjorde ett socialt och aktivt liv för deltagarna. Trots att aktiviteter inom produktivitet upplevdes begränsade drömde många deltagare om ett betalt arbete. Bristen på långsiktiga och individuellt utformade stöd samt bristande samverkan mellan olika aktörer upplevdes hindra deltagarnas möjligheter till arbete. En större förståelse för deltagarnas intressen och styrkor vid utformning av insatser och stöd behövs för att möjliggöra delaktighet i arbetslivet, vardagliga sysslor och fritidsaktiviteter utanför nätet. 

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  • Jacobsson, Jacob
    et al.
    Linköpings universitet, Institutionen för kultur och samhälle.
    Larsson, Albin
    Linköpings universitet, Institutionen för kultur och samhälle.
    All världens europeiska historia: En systematisk litteraturstudie om eurocentriska tendenser i svenska och internationella historieläroböcker på högstadiet2023Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    I denna studien undersöker vi hur eurocentrism tar form i historieläroböcker på högstadienivå. Arbetet presenterar tre frågeställningar och för att besvara dessa har vi använt oss av befintlig forskning som tagits fram genom en systematisk litteraturanalys. Frågeställningar behandlar de eurocentriska tendenser forskningen hittar i historieläroböcker, hur den riskerar att påverka undervisningen och vilka strategier skolan kan använda för att arbeta mot en interkulturell historieundervisning. Den tidigare forskningen har bearbetats med en innehållsanalys och genom analysmetoden skapades fyra kategorier för att besvara frågeställningen. De eurocentriska tendenserna som hittades var olika typer av vinklade representationer, felaktig historisk information och förskjutning av ansvar från historiska aktörer. Påverkan som riskerar att komma till följd av en eurocentrisk undervisning är att elever får ett "vi" och "dem"-perspektiv på historien och det riskerar att förvränga deras identitetsskapande process i samband med historia. Med den sista frågeställningen så togs det fram en punktlista med fyra olika strategier och åtgärder som kan tillämpas för att motverka eller arbeta runt en eurocentrisk historieundervisning.

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  • Alturkmani, Bayan
    et al.
    Linköpings universitet, Institutionen för beteendevetenskap och lärande.
    Abdulrahman, Roushin
    Linköpings universitet, Institutionen för beteendevetenskap och lärande.
    Det är smidigt Genom att koppla teorin till praktiken kan eleverna få en djupare förståelse för ämnet: Öppna laborationer i kemiundervisning- öppna sinnen2024Independent thesis Basic level (professional degree), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Laboratoriearbete anses vara en viktig del av utbildningsprocessen eftersom eleverna därigenom får färdigheter och en fördjupad förståelse för materialens egenskaper och deras samverkan. Genom att med egna ögon se hur teoretisk kunskap tillämpas i praktiken, får de en bättre förståelse för ämnets innehåll. Målet är att bekräfta vikten av att öppna laboratorier i kemilektioner ur lärarnas perspektiv samt att identifiera de utmaningar och svårigheter de står inför.

    Detta verifierades genom att genomföra en kvalitativ undersökning bland ett antal kvalificerade kemilärare på mellanstadiet och gymnasiet. De tillfrågades med hjälp av flera frågor om laboratoriernas betydelse och hur dessa bidrar till att höja elevernas förståelsenivå för att uppnå målen med kemistudier. 

    Resultaten visade att lärarna är positiva till att öppna laboratorier i kemilektioner för eleverna och tror att eleverna får en ökad förståelse under laborationer. Resultaten visade också att det finns utmaningar som lärare stöter på under laborativt arbete, inklusive brist på resurser, kemikalier, tidsbegränsningar och variationer i elevernas nivåer, vilket orsakar stress för läraren. Vissa elever har svårigheter med förståelse eller språk, vilket försenar laborativt arbete eftersom de saknar kunskap och behöver mer tid.

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  • Tufvesson, Daniel
    Linköpings universitet, Institutionen för datavetenskap.
    Automatic Speech Act Classification: Bootstrapping an embedding-based classifier from a rule-based classifier for Swedish sentences2024Independent thesis Basic level (degree of Bachelor), 12 poäng / 18 hpOppgave
    Abstract [en]

    When we speak, we carry out social actions that are mediated through spoken words. For example, through speech, we may ask for directions. These spoken actions are referred to as speech acts. We humans unconsciously understand and categorize speech acts all the time. But, how can we make computers do the same? 

     The objective of this thesis was to develop an automatic classifier for speech acts in Swedish sentences. To do this, I first annotated a test set of speech acts, following the MATTER development cycle. The sentences in this test set originate from online discussion forums. I then developed and trained a rule-based classifier using a subsample of these sentences. Finally, this rule-based classifier was used for automatically annotating a large training set, which was then used for training a neural network for classifying speech acts—essentially bootstrapping the network from the rule-based classifier. This neural network uses SBERT to compute the sentence embeddings of the sentences and then classifies their speech acts based on these embeddings. 

     The results indicate that using the MATTER cycle is a feasible approach for creating a test set for speech acts. Furthermore, the results show that the embedding-based classifier outperforms the rule-based classifier, but also that the rule-based classifier vastly outperforms the baseline. However, it was not possible to conclude if the embedding-based classifier's higher performance was due to the increase in data or because of its differing architecture. 

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  • Stendahl, Karin
    Linköpings universitet, Institutionen för datavetenskap.
    From Beeps to Melodies: Implementing and Evaluating Sound Design in Delivery Robots2024Independent thesis Basic level (degree of Bachelor), 12 poäng / 18 hpOppgave
    Abstract [en]

    This thesis applies and evaluates a  framework for sound design drawing on ethnomethodology and conversation analysis (EMCA) to explore how sound design can enhance real-world human-robot interactions. The framework is applied on the case of delivery robots used for last-mile deliveries. After analyzing video material of real interactions involving the delivery robots, workshops were conducted where sound designs were developed using vocal sketching and digital sound prototyping. The sound designs and interactions during the workshops were transcribed and analyzed, resulting in a set of sound design suggestions. These were intended by the designers to enhance interactions by clearly communicating the robots' states and actions, potentially improving safety and accessibility in public spaces as well as positively affecting the perception of the robot. However, testing and broader application is necessary to validate and generalize the sound designs as well as the framework itself. Future work should involve implementing these sounds in real-world settings and exploring the framework's applicability to other robot contexts and other groups of designers.

    Fulltekst (pdf)
    fulltext
  • Meng, Bin
    Linköpings universitet, Institutionen för tema.
    Växjö's Fossil Fuel-Free Ambition: A Case Study on the Challenges of Achieving Carbon Neutrality in a Small City2025Independent thesis Advanced level (degree of Master (Two Years)), 80 poäng / 120 hpOppgave
    Abstract [en]

    The Swedish municipality of Växjö has set the ambitious climate goal of becoming a fossil fuel-free city by 2030. Växjö has long strived to become an eco-smart, green and healthy, growing and inclusive city, and create a community that stops causing any negative climate impacts by 2030. The study uses the qualitative research method of case study. The policy document and municipal published reports from Växjö municipality provide the empirical data. Four online interviews were conducted to provide the first-hand data. This thesis aims to critically analyze the challenges and constraints that Växjö faces in its process of fossil fuel-free ambition achievement. And answering three research questions: the current strategies, challenges (in technology, policies, and social aspects), and solutions implemented by Växjö Municipality. The conclusion shows that Växjö has fall behind in achieving carbon neutrality by other Swedish peer cities, and there are gaps between symbolic actions (e.g. green branding) and real sustainable practices. The transition to a just and inclusive framework is needed to reconcile the rhetoric with reality for Växjö. This research fills the gap of a deeper understanding of complex dynamics in a small municipality like Växjö to achieve carbon neutrality and fossil fuel-free ambition, contributes to understanding the complex dynamics of local sustainability efforts, and contributes to the growing literature on energy transition theory in a specific city. It also offers practical insights for other municipalities, especially the small cities that pursue the similar climate goals. 

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  • Disputas: 2025-06-05 13:00 Hasselqvistsalen, Building 511, LinköpingBestill onlineKjøp publikasjonen >>
    Aspeqvist, Erik
    Linköpings universitet, Institutionen för biomedicinska och kliniska vetenskaper, Centrum för social och affektiv neurovetenskap. Linköpings universitet, Medicinska fakulteten.
    Prevention Targeting Mental Health and Nonsuicidal Self-injury in Adolescents2025Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Adolescent mental health is today a topic raising great concern, and reports of rising rates of mental health problems have led some to call the situation a mental health crisis. In parallel with this, there has been a realization that nonsuicidal self-injury (NSSI) is something affecting an increasingly large share of adolescents. The fact that resources are limited together with the knowledge of the burden of mental health problems have spurred a great interest in prevention. Schools are seen as arenas with great potential for deploying preventive interventions targeting adolescents. The available evidence for such interventions is, however, limited and there is a need to better understand how they could be more effective. The present thesis aims to contribute to the scientific knowledge about school-based mental health prevention by investigating the effects of a whole-school prevention program, to explore adolescents’ experiences of taking part in such a program and to shed light on heterogeneity among adolescents with a history of NSSI as well as mechanisms underlying engagement in NSSI.

    In Study I, the aim was to investigate emotion regulation and trauma symptoms as potential mediators of the association between childhood abuse and NSSI. In a sample (N = 3,169) of data from community adolescents, mediation was investigated using structural equation modeling. Both emotion regulation and trauma symptoms were found to partly mediate the relationship between childhood abuse and NSSI, and together to mediate this association completely. Study conclusions were that emotion regulation and trauma symptoms seem to be what drives NSSI rather than experiences of childhood abuse themselves.

    Study II aimed to investigate characteristics of the subgroups of adolescents acknowledging NSSI when answering a dichotomous yes/no question versus a checklist with NSSI behaviors, in a sample (N = 266) of community adolescents. These groups were found to be large and to differ from each other in several respects, with implications both in clinical and research settings. Further, cluster analysis was employed in order to identify subgroups among adolescents with NSSI and, finding such subgroups to be different from each other, it was concluded that there was a need for greater awareness of the heterogeneity within NSSI.

    In Study III, the effects of a whole-school preventive intervention were evaluated in longitudinal data from the same sample as in Study II (N = 183 with complete data from three points of measurement), harnessing the cluster-randomized, controlled design of the overall project. Effects were found on NSSI frequency, which decreased at post-intervention, and on Stigma Awareness, which increased. Conclusions of Study III was that a whole-school preventive intervention can be effective in reducing NSSI frequency and in increasing adolescents’ awareness of mental health stigma.

    Study IV was a qualitative group interview study employing thematic analysis in order to explore adolescents’ experiences of taking part in the whole-school preventive intervention as well as their perspectives on mental health. Key findings were the identification of a autonomy/help-seeking dilemma, and the perceived need of interventions targeting mental health among adolescents.

    In conclusion, the present thesis adds to the knowledge about prevention targeting NSSI and mental health among adolescents by documenting effects of a whole-school prevention program. Further, the thesis provides insights related to school-based prevention, including adolescents’ experiences, information on NSSI measurement and subgroups among individuals with a history of NSSI.

    Delarbeid
    1. Emotional Dysregulation and Trauma Symptoms Mediate the Relationship Between Childhood Abuse and Nonsuicidal Self-Injury in Adolescents
    Åpne denne publikasjonen i ny fane eller vindu >>Emotional Dysregulation and Trauma Symptoms Mediate the Relationship Between Childhood Abuse and Nonsuicidal Self-Injury in Adolescents
    Vise andre…
    2022 (engelsk)Inngår i: Frontiers in Psychiatry, E-ISSN 1664-0640, Vol. 13, artikkel-id 897081Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    BackgroundNonsuicidal self-injury (NSSI) is common in adolescents. Emotion dysregulation has been identified as a core mechanism in the development and maintenance of NSSI and it is therefore an important target when addressing NSSI. The pathogenic connection between different kinds of childhood abuse, difficulties in emotion regulation and NSSI needs further investigation. The objective of this study was to examine whether difficulties with emotion regulation and trauma symptoms, separately and together, mediate the relationships between sexual, physical and emotional abuse and NSSI. MethodCross-sectional data was collected from 3,169 adolescent high-school students aged 16-19 years (M = 18.12, SD = 0.45). Data from self-reported experiences of childhood abuse, current difficulties with emotion regulation (measured with the Difficulties with Emotion Regulation Scale, DERS-16) and trauma symptoms (measured with the Trauma Symptom Checklist for Children, TSCC), and NSSI were collected. Structural Equation Modeling (SEM) was used to test the proposed relationships between variables. ResultsThe prevalence of life-time NSSI was 27.4%. Prevalence of reported childhood abuse was 9.2, 17.5, and 18.0% for sexual, physical, and emotional abuse, respectively. Childhood abuse, difficulties with emotion regulation and trauma symptoms exhibited significant positive associations with NSSI in adolescents. Emotional dysregulation and trauma symptoms were both found to mediate the relationship between childhood abuse and NSSI. Latent variable models were found to fit data well. ConclusionResults indicate that increased levels of emotional dysregulation and trauma symptoms in relation to childhood abuse contribute to the increased risk of NSSI. Further, results point to some aspects of emotional dysregulation and trauma symptoms being more important in this regard. Clinical implications are discussed.

    sted, utgiver, år, opplag, sider
    Frontiers Media SA, 2022
    Emneord
    emotional dysregulation; childhood abuse; sexual abuse; physical abuse; emotional abuse; nonsuicidal self-injury; trauma; mediation
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-188154 (URN)10.3389/fpsyt.2022.897081 (DOI)000840658000001 ()35966492 (PubMedID)
    Merknad

    Funding Agencies|Swedish Ministry of Health and Social Affairs through Childrens Welfare Foundation Sweden [A2019/01729/MR]; Swedbank Scientific Research Foundation [17/20171208]; Swedish Research Council [2018-05820]

    Tilgjengelig fra: 2022-09-06 Laget: 2022-09-06 Sist oppdatert: 2025-05-07
    2. Measurement and stratification of nonsuicidal self-injury in adolescents
    Åpne denne publikasjonen i ny fane eller vindu >>Measurement and stratification of nonsuicidal self-injury in adolescents
    Vise andre…
    2024 (engelsk)Inngår i: BMC Psychiatry, E-ISSN 1471-244X, Vol. 24, nr 1, artikkel-id 107Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    BackgroundNonsuicidal self-injury (NSSI) is highly prevalent in adolescents. In survey and interview studies assessing NSSI, methods of assessment have been shown to influence prevalence estimates. However, knowledge of which groups of adolescents that are identified with different measurement methods is lacking, and the characteristics of identified groups are yet to be investigated. Further, only a handful of studies have been carried out using exploratory methods to identify subgroups among adolescents with NSSI.MethodsThe performance of two prevalence measures (single-item vs. behavioral checklist) in the same cross-sectional community sample (n = 266, age M = 14.21, 58.3% female) of adolescents was compared regarding prevalence estimates and also characterization of the identified groups with lifetime NSSI prevalence. A cluster analysis was carried out in the same sample. Identified clusters were compared to the two groups defined using the prevalence measures.ResultsA total of 118 (44.4%) participants acknowledged having engaged in NSSI at least once. Of these, a group of 55 (20.7%) adolescents confirmed NSSI on a single item and 63 (23.7%) adolescents confirmed NSSI only on a behavioral checklist, while denying NSSI on the single item. Groups differed significantly, with the single-item group being more severely affected and having higher mean scores on difficulties in emotion regulation, self-criticism, number of methods, higher frequency of NSSI, higher rates of suicidal ideation and suicidal behavior and lower mean score on health-related quality of life. All cases with higher severity were not identified by the single-item question. Cluster analysis identified three clusters, two of which fit well with the groups identified by single-item and behavioral checklist measures.ConclusionsWhen investigating NSSI prevalence in adolescents, findings are influenced by the researchers' choice of measures. The present study provides some directions toward what kind of influence to expect given the type of measure used, both with regards to the size of the identified group and its composition. Implications for future research as well as clinical and preventive work are discussed.

    sted, utgiver, år, opplag, sider
    BMC, 2024
    Emneord
    Nonsuicidal self-injury; Adolescence; Community sample; Measurement; Cluster analysis
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-200907 (URN)10.1186/s12888-024-05535-3 (DOI)001158455100002 ()38326791 (PubMedID)
    Forskningsfinansiär
    Linköpings universitet
    Merknad

    Funding: Linköping University

    Tilgjengelig fra: 2024-02-17 Laget: 2024-02-17 Sist oppdatert: 2025-05-07
    3. Adolescents’ experiences of a whole-school preventive intervention addressing mental health and nonsuicidal self-injury: a qualitative study
    Åpne denne publikasjonen i ny fane eller vindu >>Adolescents’ experiences of a whole-school preventive intervention addressing mental health and nonsuicidal self-injury: a qualitative study
    Vise andre…
    2024 (engelsk)Inngår i: BMC Public Health, E-ISSN 1471-2458, Vol. 24, nr 1, artikkel-id 3350Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Background Programs for mental health promotion and prevention of nonsuicidal self-injury (NSSI) in schools have gained increased focus during the last decades, but less is known about adolescents’ experiences of such interventions.

    Methods A whole-school preventive intervention targeting mental health and NSSI was delivered to six secondary schools. Adolescents participated in the Youth Aware of Mental Health program combined with an NSSI-focused psychoeducation module. Caregivers and teachers were given online psychoeducation on NSSI, and school health care staff were given a workshop on self-injury. Eleven group interviews (n = 65 participants) were conducted with adolescents (ages 13–15 years, 65% females) exploring participant experiences. Interviews were analyzed using thematic analysis and interpreted in light of a biopsychosocial understanding of adolescence.

    Results The analysis generated two main themes. The first theme, Mental health in the context of adolescence, centered around adolescents’ conception of mental health, after having taken part in the intervention, framed in a context of coping with external stressors. The dilemma of autonomy versus help-seeking was also identified as part of the first main theme. The second theme, The who, when, what, and how of the intervention, described adolescents’ experiences of the intervention. This theme included increased awareness and knowledge of mental ill-health. The participants generally agreed that the topics included are important to adolescents and emphasized that the content needs to be relatable. Several factors that influence how a school-based program is received by adolescents were identified, such as who should be targeted and when. Adolescents also identified challenges and gave recommendations for future similar projects.

    Conclusions Adolescents generally perceived addressing mental health and NSSI in schools as important. Help-seeking initiatives need to be balanced against adolescents’ need for autonomy when planning mental health prevention and intervention.

    sted, utgiver, år, opplag, sider
    BMC, 2024
    Emneord
    Adolescents; Mental health; Intervention; Nonsuicidal self-injury; Self-harm; School; Community sample; Thematic analysis
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-210262 (URN)10.1186/s12889-024-20832-y (DOI)001376858300003 ()2-s2.0-85211182770 (Scopus ID)
    Forskningsfinansiär
    Linköpings universitetSwedish Research Council, 2018–05820
    Merknad

    Funding Agencies|Swedish Research Council [2018-05820]; Linkoeping university

    Tilgjengelig fra: 2024-12-06 Laget: 2024-12-06 Sist oppdatert: 2025-05-12
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  • Rundin, Linus
    Linköpings universitet, Institutionen för datavetenskap, Artificiell intelligens och integrerade datorsystem.
    Machine Learning-Based CloudCost Estimation: Developing and Evaluating Predictive Models2025Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
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  • Zackrisson, Matilda
    Linköpings universitet, Institutionen för datavetenskap.
    Safer Collaboration Between Safety Drivers and Autonomous Trucks2024Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Autonomous vehicles are thought of as tools for increasing safety on the roads. However, automated vehicles have on multiple occasions been involved in accidents. This thesis is centered around the experience of safety drivers who test autonomous trucks. The aim is to improve safety for safety driver. I approach the task with acceptance of the fact that errors will occur due to being human (formerly known as human error). Studies in the field of human factors indicate that automation can result in decreased levels of situation awareness and mental underload, and overtrust or undertrust. There is also an increased risk of mode confusion and difficulties sustaining attention, which is a problem since the automation level of the vehicle in question is rising and the safety driver will still be neededfor the foreseeable future. I take a research through design approach and use observation,contextual interviews, co-creation, workshops, the wizard of oz method, enactment, back-casting and user testing. Through these methods, my participants and I identify critical traffic situations and propose design solutions that can make the work of the safety driver safer. The proposed design solutions are as follows: reducing the mental workload of the handover process by simplifying it; adding a feature that allows safety drivers to see what the system perceives through its sensors, which can improve their situational awareness (SA) and foster appropriate trust levels; using a colored bar on a screen behind the steerin wheel to communicate the mode; and enabling safety drivers to receive instructions for engaging auto mode.

    Fulltekst (pdf)
    Safer_collaboration_safety_drivers_autonomous_trucks
  • Disputas: 2025-06-13 10:00 K3, Kåkenhus, NorrköpingBestill onlineKjøp publikasjonen >>
    Zahabi, Najmeh
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Laboratoriet för organisk elektronik. Linköpings universitet, Tekniska fakulteten.
    Simulation and Modelling of Organic Thermoelectric Materials and Devices2025Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    As the need for autonomous and on-site renewable power sources grows, developing efficient energy solutions for distributed sensors, wearable electronics, cooling systems, and other low-power applications has become increasingly critical. Organic thermoelectric generators (TEGs), which convert low-grade heat into electrical energy through the Seebeck effect, offer a promising solution for powering these devices. Organic TEGs possess some advantages over inorganic TEGs in the context of sustainable energy harvesting because the active materials are often solution-processable at room temperature, which enables scalable patterning and printing techniques. Furthermore, these semiconductors are typically derived from Earth-abundant, non-toxic elements, making them environmentally friendly and sustainable. Among organic semiconductors, conducting polymers, particularly PEDOT (Poly(3,4-ethylenedioxythiophene)), emerge as pivotal materials in organic TEGs due to their favorable electrical and thermal properties. Thus, a deep understanding of these polymers is essential for guiding material design and optimizing device performance. In this regard, computational methods represent an important tool in studies of organic thermoelectric materials and devices since they not only provide insights into the electronic and thermal properties of materials on atomic and molecular levels but also allow for the prediction of the device's performance without the need for extensive experimental work.

    This thesis employs multi-scale computational modeling to advance the understanding and optimization of organic thermoelectric materials and devices, including: (I) Finite element method modeling to analyze and optimize the micro-TEGs, (II) Ab initio molecular dynamics simulations to investigate charge transport mechanisms in PEDOT conducting polymer, and (III) Machine learning approaches to predict and study the electronic properties of PEDOT thin films.

    Part (I) presents that achieving power densities in the range of mW cm−2 at a temperature gradient of 10 K is feasible through geometrical optimization and utilizing advanced organic thermoelectric inks. Particularly, we simulated the PEDOT:PSS/BBL:PEI micro-TEGs and improved device efficiency under varying thermal gradients using COMSOL software.

    In part (II), we developed a computational technique based on ab initio molecular dynamics to trace the temporal motion of charge carriers in a single PEDOT chain and in coupled chains with varying degrees of interaction. Subsequently, we used ab initio molecular dynamics to demonstrate that charge transport along the chains is band-like, while transport across chains follows a hopping-like mechanism. The calculated polaron mobility along the chains reached 4 cm2V−1s−1, providing a theoretical upper limit for thiophene-based conducting polymers. Also, we quantified the hopping rate between chains, consistent with Marcus theory, by analyzing polaron jumps.

    Part (III) integrates computational modeling with machine learning to explore changes in morphological and transport properties of PEDOT:Tos prepared using different solvents. We employed convolutional neural networks to achieve high accuracy (r2>0.99) in predicting electronic coupling values and significantly accelerated the analysis compared to density functional theory calculations. This approach enabled detailed investigations into how different solvents affect the electronic coupling of PEDOT dimers.

    We believe that our findings on organic thermoelectric material and devices provide a comprehensive framework for improving the performance and scalability of organic TEGs and open new avenues for further research.

    Delarbeid
    1. Charge carrier dynamics in conducting polymer PEDOT using ab initio molecular dynamics simulations
    Åpne denne publikasjonen i ny fane eller vindu >>Charge carrier dynamics in conducting polymer PEDOT using ab initio molecular dynamics simulations
    2023 (engelsk)Inngår i: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 159, nr 15, artikkel-id 154801Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    As conducting polymers become increasingly important in electronic devices, understanding their charge transport is essential for material and device development. Various semi-empirical approaches have been used to describe temporal charge carrier dynamics in these materials, but there have yet to be any theoretical approaches utilizing ab initio molecular dynamics. In this work, we develop a computational technique based on ab initio Car-Parrinello molecular dynamics to trace charge carrier temporal motion in archetypical conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT). Particularly, we analyze charge dynamics in a single PEDOT chain and in two coupled chains with different degrees of coupling and study the effect of temperature. In our model we first initiate a positively charged polaron (compensated by a negative counterion) at one end of the chain, and subsequently displace the counterion to the other end of the chain and trace polaron dynamics in the system by monitoring bond length alternation in the PEDOT backbone and charge density distribution. We find that at low temperature (T = 1 K) the polaron distortion gradually disappears from its initial location and reappears near the new position of the counterion. At the room temperature (T = 300 K), we find that the distortions induced by polaron, and atomic vibrations are of the same magnitude, which makes tracking the polaron distortion challenging because it is hidden behind the temperature-induced vibrations. The novel approach developed in this work can be used to study polaron mobility along and between the chains, investigate charge transport in highly doped polymers, and explore other flexible polymers, including n-doped ones.

    sted, utgiver, år, opplag, sider
    AIP Publishing, 2023
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-199570 (URN)10.1063/5.0169363 (DOI)001099545500009 ()37843059 (PubMedID)
    Merknad

    Funding Agencies|This work was supported by the European Commission through the Marie Sklstrok;odowska-Curie projects HORATES (Grant No. GA-955837). The computations were conducted on resources provided by the Swedish National Infrastructure for Computing (SNIC) at NSC an [GA-955837]; European Commission

    Tilgjengelig fra: 2023-12-18 Laget: 2023-12-18 Sist oppdatert: 2025-05-06
    2. Band Versus Hopping Transport in Conducting Polymers by Ab Initio Molecular Dynamics: Exploring the Effect of Electric Field, Trapping and Temperature
    Åpne denne publikasjonen i ny fane eller vindu >>Band Versus Hopping Transport in Conducting Polymers by Ab Initio Molecular Dynamics: Exploring the Effect of Electric Field, Trapping and Temperature
    2025 (engelsk)Inngår i: Advanced Electronic Materials, E-ISSN 2199-160X, Vol. 11, nr 2, artikkel-id 2400239Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Understanding charge carrier transport in conductive polymers is imperative for the materials' synthesis and optimizing devices. While most theoretical studies utilize time-independent approaches for describing charge transport, there is an interest in addressing temporal charge carrier dynamics, which provides more information than time-independent methods. In this study, ab initio molecular dynamics is utilized to gain microscopic insights into charge carrier temporal dynamics in PEDOT. It is demonstrated that transport along the chains is band-like and across the chains is hopping-like. Polaron mobility is calculated along the chains to be 4 cm2 V-1 s-1, providing a theoretical upper limit in thiophene-based conducting polymers. Also, by tracing polaron jumps between chains, the hopping rate, aligning with Marcus' theory is extracted. If an electric field can release polarons from Coulomb traps is investigated, finding that the necessary field strength surpasses typical experimental values. Two regimes of intrachain polaron movement are found: under low/intermediate electric fields, polaron moves velocity-constantly with coupled charge and lattice distortion, while under high electric fields, charge and lattice distortion decouple. The methodology applies to studying mobilities in p- and n-doped conjugated polymers, including highly doped systems with more polymer chains, and incorporates dielectric screening to address the impact of shallow and deep traps. In this study, the researchers employ the ab initio molecular dynamics technique to acquire microscopic insights into charge carrier temporal dynamics in PEDOT. It is demonstrated that transport along the chains is band-like (temperature-independent), and across the chains is hopping-like (temperature-induced). The calculated polaron mobility along the chains establishes a theoretical upper limit for charge carrier mobility in thiophene-based conducting polymers. image

    sted, utgiver, år, opplag, sider
    WILEY, 2025
    Emneord
    ab initio molecular dynamics; charge transport; conductive polymer; mobility
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-207950 (URN)10.1002/aelm.202400239 (DOI)001309880600001 ()2-s2.0-85203522922 (Scopus ID)
    Merknad

    Funding Agencies|European Commission [GA-955837]; AFM@LIU and KAW (Project "Stable Doping of Organic Semiconductors") - Swedish Research Council [2022-06725]

    Tilgjengelig fra: 2024-10-02 Laget: 2024-10-02 Sist oppdatert: 2025-05-06
    3. A Rolled Organic Thermoelectric Generator with High Thermocouple Density
    Åpne denne publikasjonen i ny fane eller vindu >>A Rolled Organic Thermoelectric Generator with High Thermocouple Density
    Vise andre…
    2024 (engelsk)Inngår i: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 34, nr 30, artikkel-id 2400982Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    The surge in the number of distributed microelectronics and sensors requires versatile, scalable, and affordable power sources. Heat-harvesting organic thermoelectric generators (TEGs) are regarded as potential key components of the future energy landscape. Recent advances in the performance of organic thermoelectric materials have made practical applications of organic TEGs more feasible than ever before, yet the challenges of designing and fabricating organic TEGs suitable for real scenarios are scarcely addressed. Specifically, small sensors and wearables demand for micro-thermoelectric generators (mu TEGs) with high power density architectures and small form factors, while typical demonstrations of organic TEGs are characterized by < 10 thermocouples (TCs) per cm(2). This work presents a rolled, organic mu TEG architecture combining large-area, solution-based deposition techniques, such as inkjet and spray-coating, and an ultrathin parylene substrate to achieve a thermocouple density of 1842 TCs cm(-2). Such demonstrative mu TEG reaches a thermoelectric conversion performance of 0.15 mu W cm(-2) at Delta T = 50 K. Such power output is well in line with finite element method simulations, which highlight the benefit of the architecture and show that remarkable power densities, in the mW cm(-2) range at Delta T = 10 K, are realistically achievable with geometrical improvements and already ongoing advancements in organic thermoelectric inks.

    sted, utgiver, år, opplag, sider
    WILEY-V C H VERLAG GMBH, 2024
    Emneord
    energy harvesting; flexible electronics; organic semiconductors; organic thermoelectrics; thermoelectric generators
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-202337 (URN)10.1002/adfm.202400982 (DOI)001174275700001 ()2-s2.0-85185505638 (Scopus ID)
    Merknad

    Funding Agencies|H2020 Marie Sklstrok;odowska-Curie Actions [955837 - HORATES]

    Tilgjengelig fra: 2024-04-12 Laget: 2024-04-12 Sist oppdatert: 2025-05-06bibliografisk kontrollert
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  • Narveby, Lisa
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Statsvetenskap. Linköpings universitet, Filosofiska fakulteten.
    Kaharevic, Ahmed
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Statsvetenskap. Linköpings universitet, Filosofiska fakulteten.
    Förorten beskriver: Digital delaktighet i Skäggetorp och Navestad2025Rapport (Annet vitenskapelig)
    Abstract [sv]

    Syftet med föreliggande rapport är att beskriva bostadsområdena och stadsdelarna Skäggetorp i Linköpings kommun och Navestad i Norrköpings kommun. Båda områden är socioekonomiskt utsatta och tidigare forskning visar att digitalt utanförskap kan kopplas till ett socioekonomiskt utanförskap. Digital delaktighet kan således vara ett sätt att öka inkludering och välstånd, därför står det särskilt i fokus i denna rapport. Digital delaktighet avgränsas till begreppen tillgång, kompetens och användning av digital teknik.

    Skäggetorp och Navestad beskrivs först med hänsyn till geografiska attribut och statistik om invånarna. Stadsdelarna jämförs främst med andra stadsdelar inom respektive kommun, men även med varandra. Skäggetorp är befolkningsmässigt större än Navestad men de har liknande förutsättningar i form av geografiskt läge, där områdena befinner sig utanför stadskärnorna. Invånarna i båda stadsdelarna skiljer sig från andra stadsdelar och kommunen som helhet i att andelen med utländsk bakgrund är högre, utbildningsnivåer lägre och den socioekonomiska standarden är generellt sett lägre, bland annat.

    Utifrån invånarna själva genom fokusgrupper, och intervjuer med professionella som arbetar i Skäggetorp och/eller Navestad beskrivs här områdena och upplevelser och praktiska erfarenheter av digital delaktighet. Totalt deltog 26 respondenter i studien. Trots olika erfarenheter och bakgrund delade respondenterna flera upplevelser om situationen kring digital delaktighet i Skäggetorp och Navestad, samt vad som behöver utvecklas.

    Tillgång till digital teknik är, enligt invånarna, inte ett stort problem. Däremot de som arbetar med service och i olika verksamheter i stadsdelarna har mer delade meningar om tillgången till digital teknik. Det är därmed inte självklart att invånare i Skäggetorp och Navestad har tillgång till telefoner och datorer, men trots bristerna så upplevs det som ett mindre hinder.

    Det största hindret för vuxna invånare i Skäggetorp och Navestad är kunskap om digital teknik. I ett samhälle där välfärdstjänster har digitaliserats och att kunna använda tekniken är grundläggande för att kunna ansöka om bidrag, deklarera och söka jobb utgör denna kunskapsbrist ett mycket akut problem. Det påpekar såväl invånare som professionella. Att tekniken utvecklas snabbt gör att de digitala klyftorna i samhället ökar i samma takt. Ungdomar och unga vuxna invånare har däremot mycket god kunskap om digital teknik, vilket gör att de måste hjälpa vuxna och äldre invånare.

    För att invånare i Skäggetorp och Navestad ska kunna använda digitala välfärdstjänster, och för att öka jämlikheten, krävs utbildande insatser och stöd från offentlig sektor i den digitala omställningen. Ett förslag som väckts av våra respondenter var att inkludera digital kompetens i SFI-utbildningen och möjlighet till fortsatta kurser i datorkunskap.

    I diskussioner om politisk delaktighet menar såväl invånare som professionella att tillit till politiker är låg generellt i Skäggetorp och Navestad. Misstro mot socialtjänsten är ytterligare ett problem som är utbrett i stadsdelarna. Det finns behov av att politiker och tjänstepersoner besöker områdena och pratar med invånarna om frågor som berör dem. Sådana insatser har tidigare gett resultat. Skriftlig information ger inte effekt enligt respondenter, utan det behövs mer frekventa besök, inte endast under valår. Dessa slutsatser är viktiga för dem som utvecklar policyer och stöttar dem som bor i utsatta stadsdelar, men även för fortsatt forskning.

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  • Gonnabathula, Venkata Satyanarayana Vamsy
    Linköpings universitet, Institutionen för datavetenskap, Artificiell intelligens och integrerade datorsystem.
    Autonomous Email Categorization using Machine Learning Models in Thunderbird Client2025Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Email categorization is a significant challenge in today's digital workplace, where sorting through messages may become complicated. This thesis addresses this problem by developing and evaluating the Thunderbird email client's autonomous email categorization system.

    Specifically, the study explores several machine learning models: Traditional algorithms (Logistic Regression, Support Vector Machines (SVM), Random Forest, XGBoost) and a Deep Learning model, Distil-BERT.

    The study also showcases the development of a custom Thunderbird extension that integrates fine-tuned machine learning models through a FastAPI backend service, providing empirical verification of the proposed approach. This implementation supports single and ensemble model predictions, offering flexibility in dealing with the trade-off between accuracy and computational resource usage.

    The findings of this research provide insights and lessons learned regarding the implementation, practical challenges, and future opportunities of automated email categorization, enriching the general understanding of using machine learning solutions for everyday productivity problems. 

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  • Stenberg, Rebecca
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Företagsekonomi. Linköpings universitet, Filosofiska fakulteten.
    Samverkan på liv och död: Samverkansutmaningar i sökandet efter ett försvunnet barn2025Rapport (Annet vitenskapelig)
    Abstract [sv]

    Organisatorisk innovation förknippas sällan med krishantering. Ändå omfattar lärandet från organisering i kriser ofta nya insikter, kunskaper och arbetssätt om det tas till vara. I det här kapitlet diskuteras samverkan i situationer där mycket står på spel. I kris och räddning möts för varandra obekanta organisationer i respons på oväntade och ofta oönskade situationer. Med utgångspunkt i den för sin tid största sökinsatsen i Sverige efter ett försvunnet barn, identifieras i det följande samverkansformer som fungerar i kris och räddning respektive sådana som inte gör det.

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  • Disputas: 2025-06-05 13:15 KEY 1, Key-huset, LinköpingBestill onlineKjøp publikasjonen >>
    Larsen, Pontus
    Linköpings universitet, Institutionen för kultur och samhälle, Avdelningen för historia, konstvetenskap och religionsvetenskap. Linköpings universitet, Utbildningsvetenskap.
    Skola, historia och fostran: Nationell identitet, värdegrundsarbete och presentism i mellanstadiets historieundervisning2025Doktoravhandling, monografi (Annet vitenskapelig)
    Abstract [sv]

    I denna avhandling undersöks historieundervisningen i årskurs 4–6 med fokus på vilka värden och normer som (re)produceras hos elever i klassrummet. Syftet är att belysa historia som fostrande praktik och att förstå vilka ”vi” är och blir genom en historieundervisning i en grundskola som både ska upprätthålla och utveckla en särskild värdegrund. Studien bygger på 70 klassrumsobservationer i årskurs 4, 5 och 6, intervjuer, läromedel, elevtexter och prov insamlade 2020–2021. Med stöd i teorier om nationalism, social identitet och meningserbjudande förstås och analyseras historiebruk som en institutionell praktik.

    Resultaten visar att undervisningen konstruerar kollektiva identiteter och påverkar elevers förståelser av det förflutna. Den ”historiske andre” framträder både som oönskad och oumbärlig för skolans värdefostran – ett hot mot ordningen men nödvändig för att definiera vad som är normalt och önskvärt. Tre delvis konkurrerande historiebruk och ”vi:n” identifieras i klassrummet: ett ”demokrati-presentistiskt”, där ett mörkt och svårt förflutet kontrasteras mot ett upplyst och moraliskt värdegrundsdrivet nu; ett ”storsvenskt”, där elever socialiseras in i traditionella dygder via ett tidsöverskridande svenskt pronomen, berättelser med kontinuitet och estetik med rötter i 1900-talets tidiga folkskola; samt ett ”individualistiskt” bruk, där agens och persona betonas i elevers och lärares tolkningar av historiska aktörer såsom drottning Kristina. Tillsammans formar dessa en samhällsbevarande och ”nygammal” värdegrund som bekräftas av majoriteten av eleverna.

    Samtidigt finns motstånd, med elever i etniskt heterogena klassrum som ställer sig utanför det svenska ”vi:et” och ifrågasätter skolans bild av ett moraliskt fulländat Sverige genom att lyfta erfarenheter av rasism och ojämlikhet. Sammantaget bidrar avhandlingen med en praktiknära förståelse för hur historia används i fostrande syften och hur svenskhet reproduceras genom undervisningen i grundskolan.   

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  • Fransson, Alva
    Linköpings universitet, Filosofiska fakulteten. Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Affärsrätt.
    Frivilligorganisationers arbetsmiljöansvar: En utredning om huruvida ett arbetsmiljöansvar finns för frivilliga i räddningsinsatser och vem som eventuellt innehar ett sådant ansvar2025Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [sv]

    Frivilliga som deltar i räddningsinsatser är inte ovanligt i dagens samhälle, och vissa typer avfrivilliga väntas öka kommande år. Organisationen av de frivilliga kan variera och ibland kanorganisation saknas helt. Det finns exempelvis frivilliga i föreningar, frivilliga som har anslutitsig till appar och frivilliga som saknar tillhörighet överhuvudtaget. Arbetsmiljöansvaret kanvariera över de frivilliga baserat på de organisatoriska skillnaderna.

    Regler om räddningsinsatser och vem som ansvarar för räddningsinsatserna finns i lagen omskydd mot olyckor (2003:778). Lagen fastställer att det huvudsakligen är kommunen somansvarar för räddningsinsatser enligt 3 kap. 7 § lagen om skydd mot olyckor. Ansvaret kanibland även ligga på staten. Det finns dessutom vissa skyldigheter för en enskild att medverkai en räddningsinsats. Möjligheter finns även för kommuner att delegera vissa åtgärder till andra,både frivilligt och genom att begära att enskilda fullgör sin tjänsteplikt.

    Arbetsmiljölagen (1977:1160) är som huvudregel tillämplig för arbetsgivare som hararbetstagare vilka utför arbete för dennes räkning enligt 1 kap. 2 § arbetsmiljölagen. Närfrivilliga som deltar i räddningsinsatser inte är arbetstagare i traditionell mening omfattas deinte av huvudregeln. Det finns även krav på en verksamhet att tillämpa reglerna om arbetsmiljö,även om den inte omfattas av huvudregeln. Om en verksamhet antingen yrkesmässigt bedriververksamhet eller innehar ett rådighetsansvar ska den tillämpa arbetsmiljölagen i vissutsträckning.

    Inom arbetsmiljöområdet får föreskrifter meddelas av Arbetsmiljöverket och dessa föreskrifterdetaljreglerar arbetsmiljön eftersom arbetsmiljölagen är en ramlag. Föreskrifterna kan påverkavilka krav som ställs på arbetsmiljön för de typer av räddningsinsatser som frivilliga deltar i.Vilka föreskrifterna är tillämpliga för kan variera från föreskrift till föreskrift.

    I uppsatsen presenteras en analys av rättsläget avseende arbetsmiljö kopplat till frivilliga inomräddningsinsatser. För att frivilliga inom räddningsinsatser ska omfattas av arbetsmiljöreglernaoch kunna ta del av skyddet som lagen erbjuder, konstateras att det krävs att någon annanbestämmelse är tillämplig än huvudregeln. Ansvar kan därtill ligga hos räddningstjänsten somansvarar för räddningsinsatsen.

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  • Glad, Wiktoria
    et al.
    Linköpings universitet, Institutionen för tema, Tema teknik och social förändring. Linköpings universitet, Filosofiska fakulteten.
    Ingemark, Anna
    Linköpings universitet, Filosofiska fakulteten. Linköpings universitet, Institutionen för kultur och samhälle, Avdelningen för historia, konstvetenskap och religionsvetenskap.
    Gestaltning av passivhus: I skärningspunkten mellan arkitektur, hållbarhet och boendekvalitet2025Inngår i: Plan: Tidskriften för samhällsplanering, ISSN 0032-0560, nr 1, s. 4-7Artikkel i tidsskrift (Annet (populærvitenskap, debatt, mm))
    Abstract [sv]

    I regeringspropositionen Politik för gestaltad livsmiljö från 2018, kopplas arkitekturen till frågor om kvalitet, hållbarhet och demokrati. Men vad innebär egentligen en ”omsorgsfullt gestaltad livsmiljö” och hur kan det omsättas i praktiken? Är de sociala, upplevelsemässiga kvaliteterna förenliga med resurseffektiva lösningar? Hur hanterar man energikraven utan att göra avkall på andra arkitektoniska värden?

    Byggsektorns materialtillverkning och uppförandeprocesser står för en betydande del av klimatavtrycket, men även energiförbrukningen i våra bostäder. Energin, som i Sverige används för att värma upp våra hem under höst, vinter och vår samt för att skapa svalka under sommaren, är resurskrävande. Därför är energiförbrukning i relation till en behaglig inomhustemperatur i våra bostäder, men också upplevelsen av boendekvalitet viktigt att lyfta fram. Om inte byggnadernas orientering, design och installerad energiteknik svarar mot de boendes förväntningar, kan det även i lågenergihus leda till att kylanläggningar installeras – vilket motverkar syftet att sänka energiförbrukningen.

    Med utgångspunkt från tidigare forskning och konkreta exempel på passivhus i Linköpings Vallastaden vill vi här peka på några utmaningar i skärningspunkten mellan arkitektur, hållbarhet och boendekvalitet.

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  • Aronsson, Josefine
    et al.
    Linköpings universitet, Institutionen för beteendevetenskap och lärande. Linköpings universitet, Utbildningsvetenskap, Kansliet för utbildningsvetenskap.
    Lindberg, Hanna
    Linköpings universitet, Institutionen för beteendevetenskap och lärande. Linköpings universitet, Utbildningsvetenskap, Kansliet för utbildningsvetenskap.
    Särskilt begåvade elevers matematikutveckling: En systematisk litteraturstudie om hur lärare kan stötta särskilt begåvade elevers matematikutveckling2025Independent thesis Basic level (professional degree), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Syftet med denna litteraturstudie var att undersöka hur läraren kan stötta särskilt begåvade elevers matematikutveckling. Datainsamlingen skedde genom databassökning i UniSearch och ERIC samt genom manuell sökning. Litteraturen granskades och analyserades med avsikt att besvara frågeställningen och syftet. Studiens resultat konstaterar att motivation är avgörande för elevernas prestation. Lärarens kunskap om särskilt begåvade elever samt lärarens förmåga att differentiera undervisningen är några av de viktigaste faktorerna för matematikutveckling eftersom eleverna behöver acceleration och berikning. Läraren kan stötta eleverna genom att stimulera högre ordningens tänkande, skapa en trygg klassrumsmiljö och ge utmanande uppgifter. Dessutom framkommer det att undervisning i grupp med likasinnade är gynnsamt.

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  • Disputas: 2025-06-10 10:00 K3, NorrköpingBestill onlineKjøp publikasjonen >>
    Liao, Mingna
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Laboratoriet för organisk elektronik. Linköpings universitet, Tekniska fakulteten.
    Opto-Thermal Management for Ionic Thermoelectric Systems2025Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    The transition to sustainable energy systems necessitates innovative approaches to energy generation, conversion, and utilization. This dissertation explores the integration of opto-thermal and ionic thermoelectric effects to develop energy-efficient solutions for thermal management and energy harvesting.

    In this thesis, we explore how temperature gradients—established and controlled through opto-thermal processes—can drive ionic thermoelectric energy conversion and be leveraged for practical applications. By integrating solar heating, radiative cooling, and evaporative cooling effects, we aim to develop a comprehensive framework for managing thermal energy to enhance energy harvesting, storage, and utilization.

    We begin by investigating how passive cooling and solar heating can be combined to generate temperature gradients, enabling continuous ionic thermoelectric energy conversion. By tuning the solar absorption and thermal radiation, we demonstrate a strategy to optimize temperature differentials for energy harvesting. Building on this study, we then introduce evaporative cooling as an additional mechanism to dynamically modulate temperature gradients. This allows for intermittent thermal regulation, which is particularly advantageous for applications requiring periodic thermal energy input, such as ionic thermoelectric supercapacitors (iTESCs).

    With these controlled thermal gradients, we then explore their application in self-powered electronics. We develop an approach that directly applying the charging/discharging current signal from iTESCs to operate resistive sensors, demonstrating a pathway toward energy-autonomous sensing technologies. These sensors harness naturally occurring temperature variations to sustain operation, reducing reliance on external power sources.

    Through this integrated approach, we establish a systematic methodology for utilizing solar-thermal-electrical pathways to drive energy applications. By coupling material design with energy conversion strategies, we hope the findings in this thesis advances the potential of ionic thermoelectric systems for sustainable power generation and adaptive energy management.

    Delarbeid
    1. Cellulose-Based Radiative Cooling and Solar Heating Powers Ionic Thermoelectrics
    Åpne denne publikasjonen i ny fane eller vindu >>Cellulose-Based Radiative Cooling and Solar Heating Powers Ionic Thermoelectrics
    Vise andre…
    2023 (engelsk)Inngår i: Advanced Science, E-ISSN 2198-3844, Vol. 10, nr 8, artikkel-id 2206510Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Cellulose opens for sustainable materials suitable for radiative cooling thanks to inherent high thermal emissivity combined with low solar absorptance. When desired, solar absorptance can be introduced by additives such as carbon black. However, such materials still shows high thermal emissivity and therefore performs radiative cooling that counteracts the heating process if exposed to the sky. Here, this is addressed by a cellulose-carbon black composite with low mid-infrared (MIR) emissivity and corresponding suppressed radiative cooling thanks to a transparent IR-reflecting indium tin oxide coating. The resulting solar heater provides opposite optical properties in both the solar and thermal ranges compared to the cooler material in the form of solar-reflecting electrospun cellulose. Owing to these differences, exposing the two materials to the sky generated spontaneous temperature differences, as used to power an ionic thermoelectric device in both daytime and nighttime. The study characterizes these effects in detail using solar and sky simulators and through outdoor measurements. Using the concept to power ionic thermoelectric devices shows thermovoltages of >60 mV and 10 degrees C temperature differences already at moderate solar irradiance of approximate to 400 W m(-2).

    sted, utgiver, år, opplag, sider
    WILEY, 2023
    Emneord
    cellulose; ionic thermoelectrics; IR emissivity controlling; radiative cooling; solar heating
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-191629 (URN)10.1002/advs.202206510 (DOI)000914108200001 ()36646654 (PubMedID)
    Merknad

    Funding Agencies|Wallenberg Wood Science Center; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University [2009 00971]; Swedish Research Council [2018-04037, 2020-00287]; Knut and Alice Wallenberg Foundation; Linkoeping University

    Tilgjengelig fra: 2023-02-06 Laget: 2023-02-06 Sist oppdatert: 2025-05-05bibliografisk kontrollert
    2. Solar Heating Modulated by Evaporative Cooling Provides Intermittent Temperature Gradients for Ionic Thermoelectric Supercapacitors
    Åpne denne publikasjonen i ny fane eller vindu >>Solar Heating Modulated by Evaporative Cooling Provides Intermittent Temperature Gradients for Ionic Thermoelectric Supercapacitors
    2024 (engelsk)Inngår i: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028Artikkel i tidsskrift (Fagfellevurdert) Epub ahead of print
    Abstract [en]

    Solar heating is important for many applications but less attractive for concepts requiring intermittent heating, such as ionic thermoelectric supercapacitors (ITESCs). However, the heating process even at constant solar illumination can be converted to temperature oscillations through water infiltration and evaporation. Here, this process is demonstrated for a carbon nanotube-cellulose membrane and used to induce temporally varying temperature gradients across an ITESC, which enables continuous operation through repeated charge and discharge cycles. A temperature variation of 10 K can be generated on the top electrode, which leads to a variation in the temperature difference across the ITESC of 7.5 K. Precise control over charge and discharge durations can be achieved by adjusting the volume and interval of the added water. The concept of temporarily adjusting temperatures by evaporative cooling may be extended to create intermittent heating also for other heat sources that are typically constant. A vertical ionic thermoelectric supercapacitor (ITESC) is driven by intermittent temperature gradients as induced by constant solar heating and periodic evaporative cooling. As shown, a solar absorber provides temperature oscillations on the top electrodes through water infiltration and evaporation. This concept enables continuous operation of ITESCs through repeated charge and discharge cycles. image

    sted, utgiver, år, opplag, sider
    WILEY-V C H VERLAG GMBH, 2024
    Emneord
    evaporative cooling; intermittent heating; ionic thermoelectric supercapacitor; solar heating; water evaporation
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-204293 (URN)10.1002/adfm.202407948 (DOI)001237443300001 ()
    Merknad

    Funding Agencies|Knut and Alice Wallenberg Foundation, Linkoping University, and industry through the Wallenberg Wood Science Center; AForsk Foundation; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University [2009 00971]; Swedish Research Council [2018-04037, 2020-00287]

    Tilgjengelig fra: 2024-06-10 Laget: 2024-06-10 Sist oppdatert: 2025-05-05
    3. Ionic Thermoelectric-Powered Resistive Sensors
    Åpne denne publikasjonen i ny fane eller vindu >>Ionic Thermoelectric-Powered Resistive Sensors
    Vise andre…
    2025 (engelsk)Inngår i: Advanced Science, E-ISSN 2198-3844, Vol. 12, nr 6, artikkel-id 2413093Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Ionic thermoelectric supercapacitors (ITESCs) are noted for their high ionic Seebeck coefficient (alpha) to convert thermal energy into electrical current through charging. This work demonstrates the utilization of the charging and discharging current from ITESCs to directly operate resistive sensors. The humidity monitoring is powered by applying a periodic temperature gradient to a connected ITESC. By leveraging these properties and residual environmental heat, ITESCs can offer a promising method for autonomously powered portable sensors.

    sted, utgiver, år, opplag, sider
    WILEY, 2025
    Emneord
    ionic thermoelectric supercapacitor; power supplying; resistive sensor
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-210709 (URN)10.1002/advs.202413093 (DOI)001377996200001 ()39679806 (PubMedID)2-s2.0-85212211521 (Scopus ID)
    Merknad

    Funding Agencies|Knut and Alice Wallenberg foundation; Linkoping University; Wallenberg Wood Science Center; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University (Faculty Grant SFO-Mat-LiU) [2009 00971]; Swedish Research Council [2020-00287, 2024-04196]; AForsk Foundation; STINT foundation [MG2021-9011]; National Natural Science Foundation of the China [22211530046, 22074010]

    Tilgjengelig fra: 2025-01-10 Laget: 2025-01-10 Sist oppdatert: 2025-05-06
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  • Barbosa, Filipe
    et al.
    Linköpings universitet, Institutionen för systemteknik, Reglerteknik. Linköpings universitet, Tekniska fakulteten.
    Löfberg, Johan
    Linköpings universitet, Institutionen för systemteknik, Reglerteknik. Linköpings universitet, Tekniska fakulteten.
    Exponential cone approach to joint chance constraints in stochastic model predictive control2025Inngår i: International Journal of Control, ISSN 0020-7179, E-ISSN 1366-5820Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Stochastic model predictive control addresses uncertainties by incorporating the probabilistic description of the disturbances into joint chance constraints. Yet, the classic methods for handling this class of constraints are often computationally inefficient and overly conservative. To overcome this, we propose to replace the nonconvex inverse cumulative distribution function of the standard normal distribution in the deterministic counterpart of these constraints with a highly accurate, exponential cone-representable approximation. This allows the constraints to be formulated as exponential cone functions, and the problem is solved as an exponential cone optimization with risk allocation as decision variables. The main advantage of the proposed approach is that the optimization problem is efficiently solved with off-the-shelf software, and with reduced conservativeness. Moreover, it applies to any problem with linear joint chance constraints subject to normally distributed disturbances. We validate our method with numerical examples of stochastic model predictive control applications.

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  • Disputas: 2025-06-04 09:00 Birgittasalen, building 240, LinköpingBestill onlineKjøp publikasjonen >>
    Eleftheriou, Andreas
    Linköpings universitet, Institutionen för biomedicinska och kliniska vetenskaper, Avdelningen för cell- och neurobiologi. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Sinnescentrum, Neurologiska kliniken i Linköping.
    Idiopathic Normal Pressure Hydrocephalus: Focus on Imaging and Clinical Symptoms2025Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Idiopathic normal pressure hydrocephalus (iNPH) is a disease that often appears in elderly population, causing gait and/or balance disturbance, cognitive decline and urinary incontinence. The prevalence of iNPH is around 3.7% and there are a lot of patients with the disease without receiving a shunt. The diagnosis of iNPH is based on International Guidelines which are updated twice since 2005. The disease has an insidious onset and progress gradually. The patients describe that the symptoms may were caused by age-related reason. The major difference of iNPH with other neurodegenerative diseases is that it is treatable with a shunt surgery and that could improve patients’ symptoms up to 84% raising the hypothesis of reversibility. Hence, iNPH is a big challenge for the neurologists. Additionally, the pathophysiological mechanism behind this disease is still unclear.

    The overall aim of this thesis is to increase the knowledge of the clinical and radiological signs in patients with iNPH and identify predicting factors for better shunt surgery outcomes.

    Paper I

    To identify any disturbance of circadian rhythm in iNPH-patients. The aim was to study any changes of the diurnal rhythm (mesor and circadian period) as well as any changes of the diurnal amplitude and acrophase of the activity in iNPH-patients before and after a shunt operation.  

    Paper II

    To identify, with the use of DTI, significant changes in hydrocephalus patients compared to controls. To correlate the radiological DTI results with the clinical features (cognition and gait) before and after a shunt surgery. To investigate early white matters changes in patients with iNPH and possibly reversibility after a shunt surgery. To establish a new technique in investigation of patients with iNPH and early identify this group. A significant correlation between ROIs results in one or more brain areas with the iNPH-results will give us the opportunity to use a specific DTI protocol to easier identify iNPH-patients who will have positive results with a shunt operation.

    Paper III

    To identify any retinal changes (retinal nerve fiber layer [RNFL] thickness, ganglion cell layer [GCL] thickness, optic disc area, rim area, and optic volume) in patients with iNPH compared with healthy individuals. Additionally, to identify any changes in the clinical symptoms before and after a CSF tap test corresponding to the OCT findings.  

    Paper IV

    To identify possible urinary and bowel symptoms in patients with iNPH and compare them to healthy individuals. The secondary aim is to evaluate possible improvement after the shunt operation.  

    Delarbeid
    1. Circadian rhythm in idiopathic normal pressure hydrocephalus
    Åpne denne publikasjonen i ny fane eller vindu >>Circadian rhythm in idiopathic normal pressure hydrocephalus
    2018 (engelsk)Inngår i: Clinical neurology and neurosurgery (Dutch-Flemish ed. Print), ISSN 0303-8467, E-ISSN 1872-6968, Vol. 164, s. 72-74Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Objectives: The pathogenesis of idiopathic normal pressure hydrocephalus (iNPH) takes place in structures close to the cerebral ventricular system. Suprachiasmatic nucleus (SCN), situated close to the third ventricle, is involved in circadian rhythm. Diurnal disturbances are well-known in demented patients. The cognitive decline in iNPH is potentially reversible after a shunt operation. Diurnal rhythm has never been studied in iNPH. We hypothesize that there is a disturbance of circadian rhythm in iNPH-patients and the aim was to study any changes of the diurnal rhythm (mesor and circadian period) as well as any changes of the diurnal amplitude and acrophase of the activity in iNPH-patients before and after a shunt operation. Patients and methods: Twenty consecutive iNPH-patients fulfilling the criteria of the American iNPH-guidelines, 9 males and 11 females, mean age 73 (49-81) years were included. The patients underwent a pre-operative clinical work-up including 10 m walk time (w10mt) steps (w10 ms), TUG-time (TUGt) and steps (TUGs) and for cognitive function an MMSE score was measured. In order to receive circadian rhythm data actigraphic recordings were performed using the SenseWear 2 (BodyMedia Inc Pittsburgh, PA, USA) actigraph. Cosinor analyses of accelerometry data were performed in "R" using non-linear regression with Levenburg-Marquardt estimation. Pre- and post-operative data regarding mesor, amplitude and circadian period were compared using Wilcoxon-Mann-Whitney test for paired data. Results: Twenty patients were evaluated before and three month post-operatively. Motor function (w10mt, w10 ms, TUGt, TUGs) was significantly improved while MMSE was not significantly changed. Actigraphic measurements (mesor, amplitude and circadian period) showed no significant changes after shunt operation. Conclusion: This is the first systematic study of circadian rhythm in iNPH-patients. We found no significant changes in circadian rhythm after shunt surgery. The conceptual idea of diurnal rhythm changes in hydrocephalus is still interesting from a theoretical standpoint and warrants further studies that could include a combination of better designed actigraphic studies in combination with neuroendocrine markers and imaging methods

    sted, utgiver, år, opplag, sider
    ELSEVIER SCIENCE BV, 2018
    Emneord
    Idiopathic normal pressure hydrocephalus; Circadian rhythm; Suprachiasmatic nucleus
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-145480 (URN)10.1016/j.clineuro.2017.11.018 (DOI)000424727200016 ()29202376 (PubMedID)
    Tilgjengelig fra: 2018-03-05 Laget: 2018-03-05 Sist oppdatert: 2025-05-05
    2. Publisher correction: Indication of Thalamo-Cortical Circuit Dysfunction in Idiopathic Normal Pressure Hydrocephalus: A Tensor Imaging Study
    Åpne denne publikasjonen i ny fane eller vindu >>Publisher correction: Indication of Thalamo-Cortical Circuit Dysfunction in Idiopathic Normal Pressure Hydrocephalus: A Tensor Imaging Study
    Vise andre…
    2020 (engelsk)Inngår i: Scientific Reports, E-ISSN 2045-2322, Vol. 10, nr 1, artikkel-id 12014Artikkel i tidsskrift (Annet vitenskapelig) Published
    sted, utgiver, år, opplag, sider
    Nature Publishing Group, 2020
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-174338 (URN)10.1038/s41598-020-69149-x (DOI)000550057500002 ()32678296 (PubMedID)2-s2.0-85087937747 (Scopus ID)
    Merknad

    Correction to: Scientific Reports https://doi.org/10.1038/s41598-020-63238-7

    Tilgjengelig fra: 2021-03-20 Laget: 2021-03-20 Sist oppdatert: 2025-05-05bibliografisk kontrollert
    3. Optical Coherence Tomography Revealing Ganglion Cell Loss in Idiopathic Normal Pressure Hydrocephalus
    Åpne denne publikasjonen i ny fane eller vindu >>Optical Coherence Tomography Revealing Ganglion Cell Loss in Idiopathic Normal Pressure Hydrocephalus
    2021 (engelsk)Inngår i: World Neurosurgery, ISSN 1878-8750, E-ISSN 1878-8769, Vol. 149, s. E1061-E1066Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    BACKGROUND: Although there may theoretically be a disturbance in the eye or the visual pathways due to abnormal cerebrospinal fluid (CSF) dynamics in idiopathic normal pressure hydrocephalus (iNPH), it has not been studied systemically. Optical coherence tomography (OCT) is a noninvasive, reproducible procedure for quantitative and qualitative analysis of retinal morphology. METHODS: OCT was used to study the eye fundus before and after a CSF tap test in patients with iNPH compared with healthy individuals (HIs). Twelve patients with iNPH (6 females and 6 males) with a median age of 76 years (64-84 years) and 21 HIs (11 females and 10 males) with a median age of 73 years (64-79 years) were included. The patients underwent neurological, cognitive, and physiotherapeutic evaluation. Brain magnetic resonance imaging, CSF tap test via lumbar puncture, and subsequently CSF analysis were performed. OCT was performed before and after CSF removal. HIs underwent OCT once. RESULTS: The patients had significantly reduced retinal ganglion cell layer thickness 71 mu m (56-81 mu m) compared with the HIs, 79.5 mu m (72-90 mu m) (P = 0.001), but no sig -ificant changes were observed before or after the CSF tap test. All patients improved in motor function in a 10-m walk test after the CSF tap test. The median CSF pressure was 15 and 1 cm H2O, respectively, before and after lumbar puncture with removal of median 43.5 mL CSF. CONCLUSIONS: This pilot study shows OCT findings that differ from HIs and implies a rational for becoming a valuable tool in the diagnosis of iNPH. Further studies are warranted to elucidate the pathology of the retina in iNPH.

    sted, utgiver, år, opplag, sider
    Elsevier Science, 2021
    Emneord
    CSF tap test; Degeneration; Ganglion cell layer; Idiopathic normal pressure hydrocephalus; Optical coherence tomography
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-175983 (URN)10.1016/j.wneu.2021.01.003 (DOI)000645617600003 ()33444824 (PubMedID)
    Tilgjengelig fra: 2021-06-01 Laget: 2021-06-01 Sist oppdatert: 2025-05-05
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  • Thelin, Johanna
    et al.
    Linköpings universitet, Institutionen för kultur och samhälle.
    Fust, Ellen
    Linköpings universitet, Institutionen för kultur och samhälle.
    Att navigera genom lässvårigheter: En systematisk litteraturstudie om metoder för ökad läsförståelse hos elever2024Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Internationella rapporter vittnar om sjunkande resultat hos svenska elever. Ett av områdena där man sett denna tendens är läsförståelse. Svenskundervisningen ska ge elever möjlighet att läsa, analysera och resonera kring olika typer av texter, och dessutom är läsning en väsentlig del genom hela skolgången. Läroplanen fastslår också skolans ansvar att bemöta och stötta elever i behov av stöd. Syftet med denna systematiska litteraturstudie är därför att granska och sammanfatta vad forskning säger om hur lärare i grundskolan kan hjälpa elever med lässvårigheter till ökad läsförståelse. Studiens resultat bygger på fyra teman som har identifierats under läsning av befintlig forskning. Dessa fyra teman är: undervisning av språkliga baskunskaper, undervisningsmetoder, självreglerat lärande genom metakognition och digitala hjälpmedel. Majoriteten av forskningen visade på att interventionerna som implementerades gav förbättrade resultat under tiden som studien pågick. Däremot kan det inte konstateras att dessa implementeringar har gett långsiktiga resultat eller att det skulle fungera i en klassrumskontext. Studien ger insikter om vikten av att våga sätta in stöd i ett tidigt skede. Samtidigt som skolan ska hjälpa varje enskild elev att utvecklas behöver också läraren ha en kritisk syn på sin egen undervisning och våga förändra den.

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  • Disputas: 2025-06-05 09:00 Temcas, T-building, LinköpingBestill onlineKjøp publikasjonen >>
    Odland, Toby
    Linköpings universitet, Institutionen för tema, Tema Genus. Linköpings universitet, Filosofiska fakulteten.
    Re-framing in Friction: On Trans-inclusive Enactment of Gender Equality Aims2025Doktoravhandling, monografi (Annet vitenskapelig)
    Abstract [en]

    How and why do inequalities become reproduced in interventions that aim to combat them? In my thesis, this question about recursive dynamics is explored with a focus on the complexity of, and ambiguity in, practical labor that is carried out around aims to change how work for change is enacted. I consider these dynamics both around the organization of labor of addressing and intervening in inequalities, and around various modes of framing gendersexed inequalities (what they are, what they do, and how they are most efficiently combated). Drawing on accounts from gender equality practitioners about their practical labor around Trans-inclusive enactment of gender equality aims, I follow their situated criticality and articulations about promises and fears around what interventions to combat gendersexed inequalities do. At sites of complication, as formal aims are to be translated into transformed organizational practice and actions, I study how practitioners experience friction both as resistance to, and as traction for, their re-framing efforts. I argue that it is through attending to such sites of dense texture that insights can be gained into the recursive dynamics through which inequalities persist despite contestation. Through an interdisciplinary inquiry, I want to speak both to institutionalization of gender equality work and aims in public organizations in Sweden, and to how some ideas of Trans-inclusive enactment become possible, desirable, and hopeful, while others become impossible, undesirable, and fearsome.

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  • Kindong, Theodore
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Informationssystem och digitalisering. Linköpings universitet, Filosofiska fakulteten.
    Johansson, Björn
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Informationssystem och digitalisering. Linköpings universitet, Filosofiska fakulteten.
    Paulsson, Victoria
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Informationssystem och digitalisering. Linköpings universitet, Filosofiska fakulteten.
    AI-Enabled Predictive Analytics in Smart Grids: The Case of Sweden2025Inngår i: Complex Systems Informatics and Modeling Quarterly, E-ISSN 2255-9922, nr 42, s. 43-62Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Smart grids (SGs) revolutionize existing power grids by using a wide range of developing disruptive technologies to generate clean, efficient, and predictable energy. Our study uses an action research method and focuses solely on the first two stages of the action research process, diagnosis and action planning, to evaluate ways to adopt artificial intelligence (AI) applications in SGs for predictive analytics in practice. The diagnosis stage of the study entails conducting a systematic literature review on AI applications in SGs, highlighting four areas of potential for predictive analytics: power outage prediction, demand response, control and coordination, and AI-enabled security to optimize decision-making, diagnose faults, and improve grid stability and security. The action planning step included a document analysis to devise methods to enable the practical implementation of AI in smart grids for predictive analytics. Finally, we address practical ways for implementing transparent AI for predictive analytics, followed by a conclusion and future research direction. The study’s key conclusion is that more research is needed to complete the action taking (implementing the solution), evaluation (assessing the results), and learning (reflecting on lessons learned) phases of the action research cycle.

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  • Jonson, Martin
    et al.
    Linköpings universitet, Institutionen för datavetenskap.
    Törnqvist, Simon
    Linköpings universitet, Institutionen för datavetenskap.
    Analyzing Root Causes and Smells of Test Flakiness by Simulating Resource Usage: A study about how system resource limitations can induce flaky behavior2025Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Flaky tests, which intermittently pass or fail when no changes have been made to the code, are a significant challenge in regression testing. Such flakiness affects the reliability of test outcomes, forcing developers to debug false alerts. Current research suggests that some test flakiness is associated with computational resource availability. In this thesis, we investigate the impact of computational resource availability, specifically CPU time, on the frequency of test flakiness in an industrial C++ codebase. We conduct experiments by rerunning tests under simulated CPU usage to quantify this impact. Furthermore, we analyze test source code characteristics and known flakiness root causes to provide insight.

    The findings reveal that CPU usage significantly influences certain types of flakiness. While concurrency-related flakiness is varyingly affected, flakiness associated with waiting asynchronously is shown to be completely dependent on CPU usage. Additionally, the study suggests that maintainability and thread sleep-related software characteristics could serve as predictors of resource-affected flakiness. These insights highlight the importance of considering computational resources in test design and suggest potential areas for improving test reliability through resource management and code analysis practices.

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  • Disputas: 2025-08-25 13:15 TEMCAS, LinköpingBestill onlineKjøp publikasjonen >>
    Törnblom, John
    Linköpings universitet, Institutionen för datavetenskap, Programvara och system. Linköpings universitet, Tekniska fakulteten. Business Area Aeronautics, Saab AB, Linköping (Real-Time Systems Laboratory).
    Efficient Formal Reasoning about the Trustworthiness of Tree Ensembles2025Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Recent advances in machine learning (ML) have demonstrated that statistical models can be trained to recognize complicated patterns and make sophisticated decisions, often outperforming human capabilities. However, current ML-based systems sometimes exhibit faulty behavior, which prevents their use in safety-critical applications. Furthermore, the increased autonomy and complexity of ML-based systems raise additional trustworthiness concerns such as explainability. To mitigate risks associated with these concerns, the European Union has agreed on a legal framework called the AI Act that governs ML-based products that are placed on the European market.

    To meet the goals set out by the AI Act with diligence, manufacturers of critical systems that leverage machine learning need new rigorous and scalable approaches to ensure trustworthiness. One natural pathway towards this aim is to leverage formal methods, a class of reasoning approaches that has proved useful in the past when arguing for safety. Unfortunately, these methods often suffer from computational scalability issues, a problem that becomes even more challenging when applied to complex ML-based systems.

    This dissertation seeks to assess and improve the trustworthiness of a class of machine learning models called tree ensembles. To this end, a reasoning engine based on abstract interpretation is developed from the ground up, exploiting unique characteristics of tree ensembles for improved runtime performance. The engine is designed to support deductive and abductive reasoning with soundness and completeness guarantees, hence enabling formal verification and the ability to accurately explain why a tree ensemble arrives at a certain prediction.

    Through extensive experimentation, we demonstrate speedup improvements of several orders of magnitude compared to current state-of-the-art approaches. More importantly, we show that many classifiers based on tree ensembles are extremely sensitive to additive noise, despite demonstrating high accuracy. For example, in one case study involving the classification of images of handwritten digits, we find that changing the light intensity of a single pixel in an image by as little as 0.1% causes some tree ensembles to misclassify the depicted digit. However, we also show that it is possible to compute provably correct explanations without superfluous information, called minimal explanations, for predictions made by complex tree ensembles. These types of explanations can help to pinpoint exactly which inputs are relevant in a particular classification. Moreover, we explore approaches for computing explanations that are also globally optimal with respect to a cost function, called minimum explanations. These types of explanations can be tailored for specific target audiences, e.g., for engineers trying to improve robustness, for system operators making critical decisions, or for incident investigators seeking the root cause of a hazard.

    Delarbeid
    1. Formal Verification of Input-Output Mappings of Tree Ensembles
    Åpne denne publikasjonen i ny fane eller vindu >>Formal Verification of Input-Output Mappings of Tree Ensembles
    2020 (engelsk)Inngår i: Science of Computer Programming, ISSN 0167-6423, E-ISSN 1872-7964, Vol. 194Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Recent advances in machine learning and artificial intelligence are now beingconsidered in safety-critical autonomous systems where software defects maycause severe harm to humans and the environment. Design organizations in thesedomains are currently unable to provide convincing arguments that their systemsare safe to operate when machine learning algorithms are used to implement theirsoftware.

    In this paper, we present an efficient method to extract equivalence classes from decision trees and tree ensembles, and to formally verify that their input-output mappings comply with requirements. The idea is that, given that safety requirements can be traced to desirable properties on system input-output patterns, we can use positive verification outcomes in safety arguments.

    This paper presents the implementation of the method in the tool VoTE (Verifier of Tree Ensembles), and evaluates its scalability on two case studies presented in current literature. We demonstrate that our method is practical for tree ensembles trained on low-dimensional data with up to 25 decision trees and tree depths of up to 20.Our work also studies the limitations of the method with high-dimensionaldata and preliminarily investigates the trade-off between large number of trees and time taken for verification.

    Emneord
    Formal verification, Decision tree, Tree ensemble, Random forest, Gradient boosting machine
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-164563 (URN)10.1016/j.scico.2020.102450 (DOI)000528192400002 ()
    Forskningsfinansiär
    Wallenberg AI, Autonomous Systems and Software Program (WASP)
    Merknad

    Funding agencies: Wallenberg AI, Autonomous Systems and Software Program (WASP) - Knut and Alice Wallenberg Foundation

    Tilgjengelig fra: 2020-03-24 Laget: 2020-03-24 Sist oppdatert: 2025-04-30
    2. An Abstraction-Refinement Approach to Formal Verification of Tree Ensembles
    Åpne denne publikasjonen i ny fane eller vindu >>An Abstraction-Refinement Approach to Formal Verification of Tree Ensembles
    2019 (engelsk)Inngår i: Computer Safety, Reliability, and Security: SAFECOMP 2019 Workshops, ASSURE, DECSoS, SASSUR, STRIVE, and WAISE, Turku, Finland, September 10, 2019, Proceedings, Springer, 2019, s. 301-313Konferansepaper, Publicerat paper (Fagfellevurdert)
    Abstract [en]

    Recent advances in machine learning are now being considered for integration in safety-critical systems such as vehicles, medical equipment and critical infrastructure. However, organizations in these domains are currently unable to provide convincing arguments that systems integrating machine learning technologies are safe to operate in their intended environments.

    In this paper, we present a formal verification method for tree ensembles that leverage an abstraction-refinement approach to counteract combinatorial explosion. We implemented the method as an extension to a tool named VoTE, and demonstrate its applicability by verifying the robustness against perturbations in random forests and gradient boosting machines in two case studies. Our abstraction-refinement based extension to VoTE improves the performance by several orders of magnitude, scaling to tree ensembles with up to 50 trees with depth 10, trained on high-dimensional data.

    sted, utgiver, år, opplag, sider
    Springer, 2019
    Serie
    Lecture Notes in Computer Science, ISSN 0302-9743, E-ISSN 1611-3349 ; 11699
    Emneord
    Formal verification, Decision trees, Tree ensembles
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-160869 (URN)10.1007/978-3-030-26250-1_24 (DOI)000561031400027 ()978-3-030-26249-5 (ISBN)978-3-030-26250-1 (ISBN)
    Konferanse
    ​Second International Workshop on Artificial Intelligence Safety Engineering
    Forskningsfinansiär
    Wallenberg AI, Autonomous Systems and Software Program (WASP)
    Merknad

    Funding agencies: Wallenberg AI, Autonomous Systems and Software Program (WASP) - Knut and Alice Wallenberg Foundation

    Tilgjengelig fra: 2019-10-11 Laget: 2019-10-11 Sist oppdatert: 2025-04-30
    3. Finding Minimum-Cost Explanations for Predictions made by Tree Ensembles
    Åpne denne publikasjonen i ny fane eller vindu >>Finding Minimum-Cost Explanations for Predictions made by Tree Ensembles
    (engelsk)Manuskript (preprint) (Annet vitenskapelig)
    Abstract [en]

    The ability to reliably explain why a machine learning model arrives at a particular prediction is crucial when used as decision support by human operators of critical systems. The provided explanations must be provably correct, and preferably without redundant information, called minimal explanations. In this paper, we aim at finding explanations for predictions made by tree ensembles that are not only minimal, but also minimum with respect to a cost function.

    To this end, we first present a highly efficient oracle that can determine the correctness of explanations, surpassing the runtime performance of current state-of-the-art alternatives by several orders of magnitude. 

    Secondly, we adapt an algorithm called MARCO from the optimization field (calling the adaptation m-MARCO) to compute a single minimum explanation per prediction, and demonstrate an overall speedup factor of 2.7 compared to a state-of-the-art algorithm based on minimum hitting sets, and a speedup factor of 27 compared to the standard MARCO algorithm which enumerates all minimal explanations.

    Emneord
    explainable AI, abstract interpretation, tree ensembles, optimization
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-213142 (URN)10.48550/arXiv.2303.09271 (DOI)
    Forskningsfinansiär
    Wallenberg AI, Autonomous Systems and Software Program (WASP)
    Merknad

    This is a pre-print publication also published at ArXiv, which has not been under subject to peer-review.

    Tilgjengelig fra: 2025-04-22 Laget: 2025-04-22 Sist oppdatert: 2025-04-30
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  • Disputas: 2025-06-05 09:00 Fornborgen, VINgården, NorrköpingBestill onlineKjøp publikasjonen >>
    Lundqvist, Erik
    Linköpings universitet, Institutionen för biomedicinska och kliniska vetenskaper, Avdelningen för kirurgi, ortopedi och onkologi. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Centrum för kirurgi, ortopedi och cancervård, Kirurgiska kliniken ViN.
    Early-Onset Colorectal Cancer: Risk Factors and Outcomes2025Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Colorectal cancer is one of the most common and lethal forms of cancer, and the Western world is experiencing an increase in the incidence among adults aged under 50 years. Up to one third of these patients, referred to as ´early-onset colorectal cancer´ (EOCRC) have a family history of the disease. Lifestyle-related risk factors and a personal history of inflammatory bowel disease (IBD), such as ulcerative colitis and Crohn’s disease, are other important risk factors. The aim of this thesis was to explore hereditary and non-hereditary risk factors associated with early-onset colorectal cancer (EOCRC) and to study the outcomes for patients with IBD coinciding with colorectal cancer.

    Study I was a population-based observational study that evaluated the awareness of hereditary colorectal cancer, measured by the number of patients referred for genetic counselling. Patients diagnosed with EOCRC in the South-Eastern Healthcare Region of Sweden from 2008 to 2017 were included, and all electronic medical records were reviewed. Of the 278 patients, 116 (42%) had been referred to genetic counselling, among whom 74 (64%) completed their genetic investigation. In 13 (18%) patients, a germline mutation was found.

    Studies II, III, and IV used the Swedish Colorectal Cancer Database as a data source, which provided multi-linkage between several national health registers.

    Study II was a case– control study of non-hereditary risk factors, such as metabolic and autoimmune disorders, and their association with EOCRC. The study examined data from 2,626 patients with EOCRC who were diagnosed in Sweden between 2007 and 2016, along with 15,759 comparators matched for age, sex, and county of residence. Metabolic disease nearly doubled the incidence of EOCRC, and IBD was associated with a sixfold increase in the incidence of EOCRC. Presence of non-inflammatory bowel disease was not associated with an increased incidence of EOCRC.

    Study III compared the recurrence-free survival (RFS) rates for patients who underwent surgical resection for rectal cancer, diagnosed between 1997 and 2021, with or without IBD. Flexible parametric survival models were used and were adjusted for time since surgery, year of diagnosis, sex, age at diagnosis, and Charlson comorbidity index score. Of the 22,082 patients included, 323 (1.5%) had IBD. Neoadjuvant radiotherapy and chemoradiotherapy were administered to 55% and 63% of patients, respectively. The overall RFS was similar between the groups (HR 1.05, 95% CI 0.87–1.26); however, a poorer RFS was observed during the first year after surgery (1-year HR 1.36, 95% CI 1.06–1.73) in patients with IBD.

    Study IV compared the overall survival, RFS, and cancer-specific survival rates for patients with and without IBDs, who were diagnosed with colon cancer from 2007 to 2021 and surgically resected with curative intent. The Cox proportional hazards model was used, adjusted for sex, age, date of colon cancer surgery, Charlson comorbidity index score, and primary sclerosing cholangitis. Among the 35,640 patients studied, 675 

    Delarbeid
    1. Hereditary evaluation and genetic counselling in young individuals with colorectal cancer in a population-based cohort
    Åpne denne publikasjonen i ny fane eller vindu >>Hereditary evaluation and genetic counselling in young individuals with colorectal cancer in a population-based cohort
    Vise andre…
    2022 (engelsk)Inngår i: Surgial oncology, ISSN 0960-7404, E-ISSN 1879-3320, Vol. 41, artikkel-id 101741Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Aim: Early-onset colorectal cancer should raise suspicions of a hereditary colorectal cancer (CRC) syndrome, including Lynch syndrome (LS) and Familial Adenomatous Polyposis (FAP). Collection of family history and genetic counselling (GC) is mandatory but previous studies have revealed low awareness of hereditary CRC among clinicians why there has been an incentive to implement universal LS screening. In this population-based cohort study, we aimed to observe the uptake of GC in the Swedish South-Eastern medical care region for young CRC patients and to investigate the frequency of patients diagnosed with LS.& nbsp;Methods: Patients below 50 years of age diagnosed with CRC between 2008 and 2017 were identified from the national Swedish Colorectal Cancer Registry. Medical records were reviewed regarding family history, co-morbidity and referral for GC, with a follow-up time of at least three years.& nbsp;Results: The analysis included 278 patients with 287 tumours, 108 (38%) located in rectum and 179 (62%) in colon. One hundred sixteen (42%) individuals were referred to the Regional Clinical Genetics service, whereof 74 (27%) underwent complete investigation. Thirteen (18%) patients were identified with a mutation, eleven (15%) had LS and two (3%) FAP. The remaining 61 (82%), without proven mutation, were considered as familial CRC. Younger age correlated with a higher chance of referral for GC.& nbsp;Conclusion: The study found that only a minority of young CRC patients underwent genetic counselling, contrary to clinical guidelines. Hereditary CRC is therefore probably underdiagnosed even among young individuals.

    sted, utgiver, år, opplag, sider
    Elsevier Science Ltd, 2022
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-185367 (URN)10.1016/j.suronc.2022.101741 (DOI)000789993900011 ()35325783 (PubMedID)
    Tilgjengelig fra: 2022-05-31 Laget: 2022-05-31 Sist oppdatert: 2025-04-30
    2. Autoimmune and Metabolic Diseases and the Risk of Early-Onset Colorectal Cancer, a Nationwide Nested Case-Control Study
    Åpne denne publikasjonen i ny fane eller vindu >>Autoimmune and Metabolic Diseases and the Risk of Early-Onset Colorectal Cancer, a Nationwide Nested Case-Control Study
    Vise andre…
    2023 (engelsk)Inngår i: Cancers, ISSN 2072-6694, Vol. 15, nr 3, artikkel-id 688Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Simple Summary Early onset of colorectal cancer (EOCRC) is increasing in developed countries. The aim was to investigate autoimmune and metabolic conditions as risk factors for EOCRC. We investigated preexisting autoimmune and metabolic diagnoses of 2626 EOCRC patients in Sweden, diagnosed in 2007-2016, together with 15,756 controls matched for birth year, sex, and county. Comorbid diagnoses were collected from the National Patient Register. A history of metabolic disease nearly doubled the incidence of EOCRC, and presence of inflammatory bowel disease (IBD) was associated with a sixfold increased incidence of EOCRC. Patients with both IBD and metabolic disease had a lower incidence of EOCRC compared with IBD patients without metabolic condition. Non-IBD autoimmune disease was not associated with an increased incidence of EOCRC. IBD and metabolic disease are risk factors for EOCRC and should be considered in screening guidelines. Incidence of early-onset (<50 years) colorectal cancer (EOCRC) is increasing in developed countries. The aim was to investigate autoimmune and metabolic conditions as risk factors for EOCRC. In a nationwide nested case-control study, we included all EOCRC cases in Sweden diagnosed during 2007-2016, together with controls, matched for birth year, sex, and county. Information on exposure of autoimmune or metabolic disease was collected from the National Patient Register and Prescribed Drugs Registry. Hazard ratios (HR) as measures of the association between EOCRC and the exposures were estimated using conditional logistic regression. In total, 2626 EOCRC patients and 15,756 controls were included. A history of metabolic disease nearly doubled the incidence hazard of EOCRC (HR 1.82, 95% CI 1.66-1.99). A sixfold increased incidence hazard of EOCRC (HR 5.98, 95% CI 4.78-7.48) was seen in those with inflammatory bowel disease (IBD), but the risk increment decreased in presence of concomitant metabolic disease (HR 3.65, 95% CI 2.57-5.19). Non-IBD autoimmune disease was not statistically significantly associated with EOCRC. IBD and metabolic disease are risk factors for EOCRC and should be considered in screening guidelines.

    sted, utgiver, år, opplag, sider
    MDPI, 2023
    Emneord
    early-onset colorectal cancer; risk factors; autoimmune disease; inflammatory bowel disease; metabolic disease; hypertension; diabetes mellitus; hyperlipidemia; obesity
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-192472 (URN)10.3390/cancers15030688 (DOI)000933814200001 ()36765646 (PubMedID)
    Merknad

    Funding Agencies|Swedish Research Council; Swedish Cancer Society; Stockholm Cancer Society; Medical Research Council of Southeast Sweden; Region Stockholm (ALF project); Bengt Ihre Foundation; Mag-Tarmfonden

    Tilgjengelig fra: 2023-03-20 Laget: 2023-03-20 Sist oppdatert: 2025-04-30
    3. Treatment and survival of non-metastatic rectal cancer in patients with inflammatory bowel disease: nationwide cohort study
    Åpne denne publikasjonen i ny fane eller vindu >>Treatment and survival of non-metastatic rectal cancer in patients with inflammatory bowel disease: nationwide cohort study
    Vise andre…
    2025 (engelsk)Inngår i: BJS Open, E-ISSN 2474-9842, Vol. 9, nr 2, artikkel-id zraf014Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Background

    Patients with inflammatory bowel disease have an increased risk of colorectal cancer. There is a scarcity of large studies with a focus on rectal cancer in patients with inflammatory bowel disease. This study aimed to compare survival in resected patients with rectal cancer with and without inflammatory bowel disease.

    Methods

    This national population-based study used the Colorectal Cancer Data Base. All Swedish patients ≥18 years of age with a diagnosis of stage I–III rectal cancer between 1997 and 2021, surgically treated with curative intent, were included and followed up until 2022. The outcome of interest was recurrence-free survival. Flexible parametric survival models adjusted for time since surgery, year of diagnosis, sex, age at diagnosis, and Charlson Co-morbidity Index were used to estimate proportional and time-dependent hazard ratios of recurrence-free survival with 95% confidence intervals.

    Results

    Overall, 22 082 patients with rectal cancer were included, among whom 323 (1.5%) had inflammatory bowel disease. Neoadjuvant radiotherapy/chemoradiotherapy was given to 55% and 63% of patients with and without inflammatory bowel disease respectively. The median follow-up time was 5.2 years (interquartile range (i.q.r.) 2.3–10) in patients with inflammatory bowel disease and 5.9 years (i.q.r. 2.9–10) in patients without inflammatory bowel disease. Based on the adjusted proportional hazards model, no overall difference in recurrence-free survival was found (HR 1.05, 95% c.i. 0.87 to 1.26). In the time-dependent adjusted model, patients with rectal cancer with inflammatory bowel disease experienced a lower recurrence-free survival during the first year after surgery (1 year HR 1.36, 95% c.i. 1.06 to 1.73), after which there was no difference in comparison with patients without inflammatory bowel disease (5 years HR 0.77, 95% c.i. 0.56 to 1.06).

    Conclusion

    Despite lower recurrence-free survival during the first year among those with inflammatory bowel disease, there were no long-term differences between patients with or without inflammatory bowel disease.

    sted, utgiver, år, opplag, sider
    Oxford University Press, 2025
    Emneord
    General Surgery, Lower Gastrointestinal Surgery
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-213361 (URN)10.1093/bjsopen/zraf014 (DOI)001468837200001 ()40131793 (PubMedID)2-s2.0-105001725046 (Scopus ID)
    Forskningsfinansiär
    Swedish Cancer SocietyThe Cancer Society in StockholmMedical Research Council of Southeast Sweden (FORSS)
    Merknad

    Funding Agencies|Swedish Cancer Society; Cancer and Allergy Foundation; Cancerforeningen i Stockholm, Bengt Ihre Research Fellowship; Bengt Ihres Foundation; Region Stockholm (ALF project); Medical Research Council of Southeast Sweden

    Tilgjengelig fra: 2025-04-30 Laget: 2025-04-30 Sist oppdatert: 2025-05-06
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  • Bennett, E
    et al.
    McGill University.
    Biggs, O
    Stellenbosch University.
    Calderón Contreras, R
    Universidad Autónoma Metropolitana.
    Golden Kroner, R
    Wolrd Wildlife Fund - US.
    Vianna Mansur, A
    Saint Andrew First-Called Georgian University of the Patriarchate of Georgia.
    Woroniecki, S
    Wildfowl & Wetlands Trust.
    Acar, S
    Boğaziçi University.
    Aksoy, Z
    Boğaziçi University.
    Alpizar, F
    Wageningen University & Research.
    Lam, D
    Leuphana University of Lüneburg.
    Horcea-Milcu, A-I
    University of Kassel.
    Linnér, Björn-Ola
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten. Linköpings universitet, Centrum för klimatpolitisk forskning, CSPR.
    Mehta, L
    Norwegian University of Life Sciences.
    Campos, C
    Instituto Argentino de Investigaciones de las Zonas Áridas (IADIZA, CONICET-Universidad Nacional de Cuyo-Gob. Mendoza).
    Nishi, M
    United Nations University Institute for the Advanced Study of Sustainability.
    Rahiri, N
    Massey University.
    Richardson, M
    University of Derby.
    Sabinot, C
    Institut de Recherche pour le Développement.
    Simão Seixas, C
    Universidade Estadual de Campinas (UNICAMP).
    Stokland, H
    Norwegian Institute for Nature Research.
    Balvanera, Patricia
    Mexico.
    Chan, Kai
    Canada.
    Guibal, C
    Université de Montpellier, .
    Garibaldi, L
    National University of Río Negro, Argentina.
    Chapter 3: How transformative change occurs2024Inngår i: Thematic Assessment Report on the Underlying Causes of Biodiversity Loss and the Determinants of Transformative Change and Options for Achieving the 2050 Vision for Biodiversity of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services / [ed] O’Brien, K., Garibaldi, L., and Agrawal, A., Bonn, Germany: IPBES Secretariat , 2024, s. 1-81Kapittel i bok, del av antologi (Annet vitenskapelig)
    Abstract [en]

    Chapter 3 assesses the literature and a set of cases on how transformative change occurs. Based on this assessment, it identifies six broad approaches to transformative change and synthesizes key insights for achieving the 2050 Vision for Biodiversity and global sustainability. In combination, these six approaches can promote, accelerate and scale transformative change for global sustainability in diverse contexts. Chapter 3 recognizes that transformative change takes place in a complex world and that navigating such change calls for adaptability, agility, transparency, continuous monitoring, evaluation and adaptive learning across multiple scales. Other elements for navigating transformative change are delineated by the findings of the assessment below.  

    Fulltekst (pdf)
    fulltext
  • Nilsson, Hannes
    Linköpings universitet, Institutionen för teknik och naturvetenskap.
    The Renewal of Water and Sewage Networks: Is the Process Possible to improve?2025Independent thesis Basic level (degree of Bachelor), 10,5 poäng / 16 hpOppgave
    Abstract [en]

    The delays of the exchanging of the water and sewage systems in Sweden is as of today a fact that emerge two questions, how did we end up in this situation and what can be done to catch up? The purpose of this thesis has been to investigate, analyze and to find answers to some of the underlying questions regarding why we are where we are today, and what we can do to get back on track. The objective of the thesis has been to map out both the historical and the current as well as the future perspective to identify potential efficiency measures that can be taken within the exchange of the water and sewage networks. The method of the study has been to investigate three question formulations, the investment situation, strategies, and communication in dialogue with two different water and sewage operators, Tekniska Verken in Linköping, and Nodra in Norrköping, and an engineering consultancy firm, Sweco. The approach of the study has been to break down the question formulations into multiple underlying questions and answer these with literature review and data collection through surveys and interviews. The theory section points out that the major problem of the current investment situation is that the operators are not allowed to create funds for future use. Also, the section states that the most successful strategy is to have long-term plans and how the communication should be conducted in shorter and more direct chains. The result section summarizes the responses gathered in the surveys and interviews. In the analysis of the results some short comings were identified that can be directly tied to what the theory section discusses about how the current legislation regarding funding is an obstacle as well as that the communication chain currently is too long, complex, and ineffective. Multiple conclusions can be drawn with these findings at hand, for instance regarding how the current investment situation needs an overhaul and that the legislation may have to change, to make sure that the operators can keep up with the need of increased exchange rate. Concerning strategies the two operators have partly different approaches, that both have their pros and cons, and that an exchange of strategies and knowledge between the two of them could be beneficial. Lastly, regarding the communication, a conclusion is drawn that there are room for improvement in the usage of better tools and that there is a need for training and education to be conducted throughout the different instances of the chain. In the discussion section some ideas are presented that could be of use to find ways to further increase the efficiency in the exchange of the water and sewage systems with implementation of IoT-systems as one example.

    Fulltekst (pdf)
    fulltext
  • Lundqvist, Erik
    et al.
    Linköpings universitet, Medicinska fakulteten. Region Östergötland, Centrum för kirurgi, ortopedi och cancervård, Kirurgiska kliniken ViN. Linköpings universitet, Institutionen för biomedicinska och kliniska vetenskaper, Avdelningen för kirurgi, ortopedi och onkologi.
    Westberg, Karin
    Division of Surgery, Danderyd Hospital, Stockholm; Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm.
    Dietrich, Caroline E
    Department of Medicine Solna, Clinical Epidemiology Division, Karolinska Institutet, Stockholm.
    Everhov, Åsa H
    Department of Medicine Solna, Clinical Epidemiology Division, Karolinska Institutet, Stockholm; Department of Clinical Science and Education, Södersjukhuset, Stockholm.
    Myrelid, Pär
    Linköpings universitet, Institutionen för biomedicinska och kliniska vetenskaper, Avdelningen för kirurgi, ortopedi och onkologi. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Centrum för kirurgi, ortopedi och cancervård, Kirurgiska kliniken US.
    Glimelius, Bengt
    Department of Oncology and Pathology, Karolinska Institutet, Stockholm; Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala.
    Martling, Anna
    Department of Molecular Medicine and Surgery, Karolinska Institutet , Stockholm ,;Department of Pelvic Cancer, Karolinska University Hospital , Stockholm ,.
    Nordenvall, Caroline
    Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm; Department of Pelvic Cancer, Karolinska University Hospital, Stockholm.
    Treatment and survival of non-metastatic rectal cancer in patients with inflammatory bowel disease: nationwide cohort study2025Inngår i: BJS Open, E-ISSN 2474-9842, Vol. 9, nr 2, artikkel-id zraf014Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background

    Patients with inflammatory bowel disease have an increased risk of colorectal cancer. There is a scarcity of large studies with a focus on rectal cancer in patients with inflammatory bowel disease. This study aimed to compare survival in resected patients with rectal cancer with and without inflammatory bowel disease.

    Methods

    This national population-based study used the Colorectal Cancer Data Base. All Swedish patients ≥18 years of age with a diagnosis of stage I–III rectal cancer between 1997 and 2021, surgically treated with curative intent, were included and followed up until 2022. The outcome of interest was recurrence-free survival. Flexible parametric survival models adjusted for time since surgery, year of diagnosis, sex, age at diagnosis, and Charlson Co-morbidity Index were used to estimate proportional and time-dependent hazard ratios of recurrence-free survival with 95% confidence intervals.

    Results

    Overall, 22 082 patients with rectal cancer were included, among whom 323 (1.5%) had inflammatory bowel disease. Neoadjuvant radiotherapy/chemoradiotherapy was given to 55% and 63% of patients with and without inflammatory bowel disease respectively. The median follow-up time was 5.2 years (interquartile range (i.q.r.) 2.3–10) in patients with inflammatory bowel disease and 5.9 years (i.q.r. 2.9–10) in patients without inflammatory bowel disease. Based on the adjusted proportional hazards model, no overall difference in recurrence-free survival was found (HR 1.05, 95% c.i. 0.87 to 1.26). In the time-dependent adjusted model, patients with rectal cancer with inflammatory bowel disease experienced a lower recurrence-free survival during the first year after surgery (1 year HR 1.36, 95% c.i. 1.06 to 1.73), after which there was no difference in comparison with patients without inflammatory bowel disease (5 years HR 0.77, 95% c.i. 0.56 to 1.06).

    Conclusion

    Despite lower recurrence-free survival during the first year among those with inflammatory bowel disease, there were no long-term differences between patients with or without inflammatory bowel disease.

    Fulltekst (pdf)
    fulltext
  • Disputas: 2025-06-05 10:15 Ada Lovelace, LinköpingBestill onlineKjøp publikasjonen >>
    Ho, Du
    Linköpings universitet, Institutionen för systemteknik, Reglerteknik. Linköpings universitet, Tekniska fakulteten.
    Closed-loop Diagnosis Using Submodels: With Applications to Quadcopters2025Doktoravhandling, monografi (Annet vitenskapelig)
    Abstract [en]

    Drones, like many other mechanical systems, operate under closed-loop control to ensure safety and economic efficiency. Real-time feedback is crucial for a drone to follow its predefined missions and to deal with hazardous conditions. Achieving optimal performance in such systems often requires a mathematical model, typically obtained using system identification techniques. Furthermore, monitoring changes in the system is essential, before an unexpected change leads to a fault and eventually a failure, causing costly disruptions of the system.

    This thesis investigates ways of obtaining robust fault detection and accurate parameter estimation in a closed-loop system. In detail, we focus on subsystems of larger systems where the parameters or changes are observable. This approach, referred to as submodeling, is adopted since examining the entire system dynamics can be challenging due to the complexities and interconnections between components. Moreover, it involves selecting and measuring only a subset of signals, which reduces the number of sensors required. However, the resulting submodels use certain measurements as the outputs and others as the inputs, yielding closed-loop errors-in-variables (EIV) problems.

    The first contribution addresses fault detection in closed-loop EIV systems. We apply a projection-based nonadditive fault detection method where the residual is projected to a subspace that is orthogonal to additive faults and disturbances. By doing so, we demonstrate that additive and nonadditive faults can be decoupled, making residuals sensitive only to the nonadditive ones. This allows the nonadditive fault to be detected accurately despite the occurrence of additive faults, closed-loop effects, and disturbances.

    In the second contribution, we establish a specific equivalence concept related to the residuals of models concerning input-output repartitionings, which is useful for studying estimators. Moreover, we show that the basic instrumental Variable (IV) estimator can yield equivalent estimates which are independent of the input-output partitionings, unlike other standard system identification methods. The algebraic equivalence of the basic IV estimates holds regardless of the true system structure, noise properties, and data length.

    The third contribution is to utilize the approach to derive submodels of a quadcopter. More specifically, we exploit the cancellation of shared dynamics between actual inputs and measured outputs, allowing for the elimination of some input signals. These submodels, addressing various aspects of the quadcopter’s dynamics, are simpler than a complete model but still sufficient for the intended applications.

    The fourth contribution is to validate all methods developed in this thesis using simulated and experimental data from a quadcopter. To do so, we apply a standard motion-planning framework based on the simulation model of the drone to establish a detailed experimental procedure. This procedure allows us to define scenarios similar to real-world tasks of the drone in a testbed and to obtain excitation trajectories that produce informative data. Both the simulated and experimental data-based validations show promising results.

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  • Disputas: 2025-06-05 14:00 K3, Kåkenhus, NorrköpingBestill onlineKjøp publikasjonen >>
    Andersson, Magdalena
    Linköpings universitet, Institutionen för beteendevetenskap och lärande, Avdelningen för lärande, estetik och naturvetenskap. Linköpings universitet, Utbildningsvetenskap.
    Känslors plats i grundskolans NO-undervisning: Praktiknära studier om förundran och meningsskapande kring evolutionära processer2025Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [sv]

    Det övergripande syftet med denna avhandling är att bidra med ny kunskap om hur lärare kan skapa utrymme för förundran i grundskolans NO-undervisning och hur detta kan påverka elevers engagemang i, och meningsskapande om, ett planerat lärandemål. Förundran är ett känslotillstånd som uppstår då en person konfronteras med något som går utanför det man förväntar sig eller i mötet med något som upplevs som obegripligt. Förundran kan också uppstå i samband med en oväntad insikt om komplexiteten eller skönheten i något vanligt eller om man plötsligt ser något ur ett helt nytt perspektiv. Denna känsla klassificeras som epistemisk eftersom den ofta leder till en vilja att förstå mer och ett engagemang i att utforska och inhämta ny kunskap. Avhandlingen fokuserar på hur förundran kan användas som ett pedagogiskt verktyg i samband med evolutionsundervisning, ett ämnesområde som visat sig vara utmanande både för elever och lärare.

    Tidigare forskning om förundrans roll för elevers lärande och engagemang är till övervägande del baserad på teoretiska och filosofiska resonemang eller genomförda som kliniska studier eller via enkäter. I avhandlingens delstudier prövas föreslagna undervisningsupplägg från dessa studier i klassrumssituationer. Avhandlingens studie bygger på så kallade formativa interventioner, där lärare och forskare samarbetar om hur undervisning kan planeras och genomföras. Avhandlingen innefattar två delstudier, båda genomförda vid en F-9 skola i Mellansverige. Den första delstudien involverade elever och lärare i årskurs 2, 3 och 4 och fokuserade på att utveckla och pröva de teoretiskt beskrivna undervisningsuppläggen samt metoder för empiriinsamling och analys. Den andra delstudien genomfördes i en årskurs 7 under ett avsnitt om evolution.

    Empirin samlades in genom videofilmade klassrumsobservationer, ljudinspelade lärar- och elevintervjuer samt skriftliga elevreflektioner. Empirin analyserades med hjälp av kvalitativa innehållsanalyser samt fördjupande multimodal analys av filmat material i delstudie två.

    Sammanfattningsvis visar resultaten på några gemensamma förhållningssätt som gav utrymme för elevers förundran; att använda berättande för att skapa en miljö som gynnar förundran, att ge eleverna möjlighet att påverka hur objekt eller processer undersöks, att skapa en trygg miljö där känslor får uttryckas och att ge eleverna möjlighet att stanna upp och stanna kvar i sitt meningsskapande.  

    Resultaten pekar även på att undervisningsformer som inkluderade tävlingsmoment eller tidspress begränsade elevernas möjligheter att uppleva förundran. I vissa fall gav detta dock utrymme för andra epistemiska känslor, såsom förvirring, frustration och nyfikenhet, som tillsammans bidrog till att fördjupa elevernas resonemang kring komplexa evolutionära begrepp.

    Delarbeid
    1. The Role of Wonder in Students’ Conception of and Learning About Evolution
    Åpne denne publikasjonen i ny fane eller vindu >>The Role of Wonder in Students’ Conception of and Learning About Evolution
    2023 (engelsk)Inngår i: Center for Educational Policy Studies Journal (C·E·P·S Journal), ISSN 1855-9719, E-ISSN 2232-2647, Vol. 13, nr 1, s. 35-61Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Learning about evolution can be challenging for students, as a full understanding may require them to see the world in new ways, to master a disciplinary language and to understand complex processes. Drawing on a long line of theoretically grounded arguments of philosophers and researchers for including wonder in science teaching, we report on the results of an empirical study with the primary aim of investigating the role of wonder in students’ learning about evolution. The study was carried out through a formative intervention in which two researchers in science education collaborated with a seventh-grade teacher. Over a period of six weeks, 45 students participated in lessons and workshops aimed at eliciting a sense of wonder in relation to concepts that are known to impact the learning of evolution. We incorporated four ‘triggers’ to elicit students’ wonder in the science class: aesthetic experiences, defiance of expectations, agency and awareness of a mystery within the ordinary. Logbook entries and interviews with student pairs provided empirical material for a qualitative analysis of the role of wonder in the students’ meaning-making about, learning of and engagement in evolu-tion. The results show that it is possible to design science teaching that triggers students’ wonder in relation to an intended learning object. The results also reveal that the participating students described their sense of wonder in qualitatively different ways and that they still struggle

    Emneord
    evolution, formative intervention, lower secondary school, threshold concepts, wonder
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-213353 (URN)10.26529/cepsj.1489 (DOI)2-s2.0-85160403834 (Scopus ID)
    Tilgjengelig fra: 2025-04-30 Laget: 2025-04-30 Sist oppdatert: 2025-05-05bibliografisk kontrollert
    2. Att skapa en känsla för evolution: högstadieelevers epistemiska känslor och meningsskapande om naturligt urval
    Åpne denne publikasjonen i ny fane eller vindu >>Att skapa en känsla för evolution: högstadieelevers epistemiska känslor och meningsskapande om naturligt urval
    2025 (engelsk)Inngår i: Forskul - Forskning om undervisning och lärande, E-ISSN 2001-6131, Vol. 13, nr 2Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [sv]

    Denna artikel bygger på resultat från ett samverkansprojekt där en högstadie-lärare och forskare gemensamt genomförde formativa interventioner för att undersöka epistemiska känslor – särskilt förundran – som pedagogiskt verktyg i undervisning om evolutionära processer. Förundran beskrivs ofta som en känsla med stor potential att stärka elevers engagemang och förståelse av naturvetenskap. Trots detta finns det få empiriska studier som har undersökt fenomenet i autentiska klassrumssammanhang. I denna studie analyserades ljud- och videoinspelningar av en lektion som utformats för att främja upplevelser av förundran. Genom kvalitativ innehållsanalys i kombination med multimodal interaktionsanalys identifierades hur elever skapade mening om, och uttryckte känslor i relation till undervisningens innehåll. Resultaten visar att eleverna resonerade mer djupgående kring begreppen konkurrens, variation och anpassning – processer som de även visat känslomässigt engagemang inför. Studien belyser den pedagogiska potentialen i att skapa utrymme för epistemiska känslor i undervisning om komplexa naturvetenskapliga processer.

    Abstract [en]

    This study is based on a collaborative project in which a lower secondary science teacher and researchers carried out formative interventions to explore epistemic emotions – particularly wonder – as a pedagogical tool in teaching evolutionary processes. Wonder is frequently highlighted as an emotion with strong potential to enhance students’ engagement in and understanding of science. However, few empirical studies have examined this phenomenon in authentic classroom settings. By using qualitative content analysis combined with multimodal interaction analysis of an audio- and video-recorded lesson designed for wonder, the study identified how students made meaning of and expressed emotions in relation to the subject matter. The results show that students engaged in more in-depth reasoning around the concepts of competition, variation, and adaptation – processes that also evoked emotional engagement. The study highlights the pedagogical potential of intentionally creating space for epistemic emotions in the teaching of complex scientific processes.

    sted, utgiver, år, opplag, sider
    Lärarstiftelsen, 2025
    Emneord
    epistemic emotions, evolution, formative intervention, secondary school, wonder, epistemiska känslor, evolution, formativ intervention, förundran, grundskola
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-213354 (URN)10.61998/forskul.v13i2.24322 (DOI)
    Tilgjengelig fra: 2025-04-30 Laget: 2025-04-30 Sist oppdatert: 2025-04-30bibliografisk kontrollert
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  • Andersson, Magdalena
    et al.
    Linköpings universitet, Institutionen för beteendevetenskap och lärande, Avdelningen för lärande, estetik och naturvetenskap. Linköpings universitet, Utbildningsvetenskap.
    Ottander, Christina
    Institutionen för naturvetenskapernas och matematikens didaktik, Umeå universitet, Umeå, Sverige.
    Sundberg, Bodil
    Institutionen för biologi och miljö, Linnéuniversitetet, Kalmar, Sverige.
    Att skapa en känsla för evolution: högstadieelevers epistemiska känslor och meningsskapande om naturligt urval2025Inngår i: Forskul - Forskning om undervisning och lärande, E-ISSN 2001-6131, Vol. 13, nr 2Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [sv]

    Denna artikel bygger på resultat från ett samverkansprojekt där en högstadie-lärare och forskare gemensamt genomförde formativa interventioner för att undersöka epistemiska känslor – särskilt förundran – som pedagogiskt verktyg i undervisning om evolutionära processer. Förundran beskrivs ofta som en känsla med stor potential att stärka elevers engagemang och förståelse av naturvetenskap. Trots detta finns det få empiriska studier som har undersökt fenomenet i autentiska klassrumssammanhang. I denna studie analyserades ljud- och videoinspelningar av en lektion som utformats för att främja upplevelser av förundran. Genom kvalitativ innehållsanalys i kombination med multimodal interaktionsanalys identifierades hur elever skapade mening om, och uttryckte känslor i relation till undervisningens innehåll. Resultaten visar att eleverna resonerade mer djupgående kring begreppen konkurrens, variation och anpassning – processer som de även visat känslomässigt engagemang inför. Studien belyser den pedagogiska potentialen i att skapa utrymme för epistemiska känslor i undervisning om komplexa naturvetenskapliga processer.

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  • Sundberg, Bodil
    et al.
    School of Science and Technology, Örebro University, Örebro, Sweden.
    Andersson, Magdalena
    School of Science and Technology, Örebro University, Örebro, Sweden.
    The Role of Wonder in Students’ Conception of and Learning About Evolution2023Inngår i: Center for Educational Policy Studies Journal (C·E·P·S Journal), ISSN 1855-9719, E-ISSN 2232-2647, Vol. 13, nr 1, s. 35-61Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Learning about evolution can be challenging for students, as a full understanding may require them to see the world in new ways, to master a disciplinary language and to understand complex processes. Drawing on a long line of theoretically grounded arguments of philosophers and researchers for including wonder in science teaching, we report on the results of an empirical study with the primary aim of investigating the role of wonder in students’ learning about evolution. The study was carried out through a formative intervention in which two researchers in science education collaborated with a seventh-grade teacher. Over a period of six weeks, 45 students participated in lessons and workshops aimed at eliciting a sense of wonder in relation to concepts that are known to impact the learning of evolution. We incorporated four ‘triggers’ to elicit students’ wonder in the science class: aesthetic experiences, defiance of expectations, agency and awareness of a mystery within the ordinary. Logbook entries and interviews with student pairs provided empirical material for a qualitative analysis of the role of wonder in the students’ meaning-making about, learning of and engagement in evolu-tion. The results show that it is possible to design science teaching that triggers students’ wonder in relation to an intended learning object. The results also reveal that the participating students described their sense of wonder in qualitatively different ways and that they still struggle

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  • Disputas: 2025-06-04 10:15 TEMCAS, T-building, LinköpingBestill onlineKjøp publikasjonen >>
    Axelsson Bjerg, Mette
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Improved utilization of agricultural residues in biogas processes: Applications of combined post-treatment and post-digestion2025Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Agricultural residues and lignocellulosic materials (such as manure and plant residues) are important resources due to their abundance. Their extended usage in anaerobic digestion (AD), at which organic matter (OM) is degraded in the absence of oxygen to produce biomethane, is important in the effort to increase both Sweden’s biomethane production towards 10 TWh by 2030 and reaching EUs goal of 350 TWh by 2030. Agricultural residues are known to be hard to degrade in AD processes, therefore exploring new ways to improve their degradation is strategic to expand biogas production, mainly consisting of biomethane and carbon dioxide. AD has many applications, such as nutrients recovery in waste management, biofuel production, renewable heating and electricity generation, and production of green chemicals and fodder. Promoting the use of AD processes is an important step towards the establishment of sustainable waste handling of organic residues as well as industrial and agricultural activities.

    In this thesis, novel approaches are evaluated to enhance the biogas production from agricultural residues. The thesis focuses on post-processing of residues from AD, so called digestate, to harness biogas potentials from organic resources rich in lignocellulose that are currently underutilized. The potential for improving the degradation of residual OM through post-treatment and post-digestion was investigated through several long-term studies using semi-continuously fed stirred reactors and a batch study. For the first study semi-continuous-stirred tank reactors were used to evaluate moderate thermal treatment (70 °C, 1 h) on different types of digestate from full-scale biogas plants (food waste, agricultural waste and mainly manure-based agricultural waste) to target residual OM. In the second study the solid fraction of phase-separated agricultural digestate was post-digested with starch in batch to determine if a priming effect (i.e., increased turnover of OM due to the addition of easily degradable carbon) could be obtained. In the third experimental study priming was investigated in a semi-continuous system and a main digester and post-digester were operated using a substrate mix of agricultural waste and manure. Starch was added every other day to evaluate if a priming effect was detected. In the final study, the effects on recirculation of digestate were evaluated to stabilize a perturbed system consisting of a main digester and post-digester operating on plant based agricultural waste, highlighting the advantages of a post-digester for a perturbed system. For all studies biogas and biomethane production was evaluated, in addition to process parameters such as pH, total solids, volatile solids, and ammonium-nitrogen concentrations. Microbial communities were analyzed to investigate if any structural community changes occurred when a priming agent was added, and how the microbial community changed during process disturbances.

    The results showed that moderate thermal treatment efficiency varied depending on the type of digestate origin. Food waste digestate showed the highest improvement (21-22 %) in biomethane production, followed by the plant based agricultural waste (9 %). The manure and agricultural digestate gave inconclusive results due to process disturbances. A significant increase in the dissolved organic carbon due to thermal treatment was observed for all three digestate types (110-200, 24-92 and 4-73 % for food waste, agricultural waste, and manure-based agricultural waste, respectively). Priming effects, due to small share of starch amendment, could be observed both in batch and semi-continuous systems which had a positive impact on the rate of the process as well as the overall biogas production and specific methane production. Starch addition led to a shift in the microbial community structure, which likely benefited lignocellulolytic activities as an increased degradation of cellulose, hemicellulose and total sugar were detected. Finally, recirculation of whole digestate from the post-digester was proved to stabilize the perturbed AD process by increasing the pH, ammonium-nitrogen concentration, and alkalinity in the main digester. Mechanistically, the post-treatments can be related to increased dissolution of organic matter (thermal treatment), increased hydrolytic, fermentative, and methanogenic activity (priming) and recirculation of nutrients and biomass as well as increased solids content (recirculation).

    The thesis highlights the advantages that post-treatments and post-digestion can provide, both for increased degradation of residual organic structures but also overall stabilization for agricultural processes. All the post-treatments investigated relate to current processes such as hygienization, redirection of substrates and digestate management which highlights their opportunities for further applications in full-scale.

    Delarbeid
    1. Moderate thermal post-treatment of digestate to improve biomethane production from agricultural- and food waste
    Åpne denne publikasjonen i ny fane eller vindu >>Moderate thermal post-treatment of digestate to improve biomethane production from agricultural- and food waste
    Vise andre…
    2024 (engelsk)Inngår i: Bioresource Technology Reports, E-ISSN 2589-014X, Vol. 27, artikkel-id 101887Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    The aim of this study was to assess the feasibility of moderate thermal treatment (70 C for one hour) of digestate in combination with post-digestion targeting residual biomethane potentials from three full-scale biogas plants digesting food waste (FW), agricultural waste (AW) and a mixture of AW and manure (AWM). Dissolved organic carbon (DOC), biomethane production, and digestate quality were investigated. For the study six laboratory-scale continuously stirred tank biogas reactors working as post-digesters, with thermally-treated and non-treated digestate were used. DOC for thermally-treated digestates increased significantly (t-test, p < 0.05); FW-digestate (110–200 %), AW-digestate (24–92 %) and for AWM-digestate (4–73 %). Indexes for corresponding DOC quality showed lower apparent organic molecular weights and decreased aromaticity (with the exception of FW-digestate). Thermal treatment of digestate improved the biomethane production during post-digestion by 21–22 % (FW-digestate) and 9 % (AW-digestate). For AMW-digestate no clear positive effect was observed, most likely due to biogas plant operational process disturbances. 

    sted, utgiver, år, opplag, sider
    ELSEVIER, 2024
    Emneord
    Biogas, Digestate, Thermal treatment, Post-treatment, Post-digestion, Agricultural waste, Food waste
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-206134 (URN)10.1016/j.biteb.2024.101887 (DOI)001261070100001 ()
    Forskningsfinansiär
    Swedish Energy Agency, 35624-2
    Merknad

    Funding Agencies|Swedish Energy Agency [35624-2]

    Tilgjengelig fra: 2024-08-06 Laget: 2024-08-06 Sist oppdatert: 2025-04-30bibliografisk kontrollert
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  • Gestrin, Elliot
    Linköpings universitet, Institutionen för datavetenskap, Artificiell intelligens och integrerade datorsystem.
    NL2Plan: Robust LLM-Driven Planning from Minimal Text Descriptions2024Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Today's classical planners are powerful, but modeling input tasks in formats such as PDDL is tedious and error-prone. In contrast, planning with Large Language Models (LLMs) allows for almost any input text, but offers no guarantees on plan quality or even soundness. In an attempt to merge the best of these two approaches, some work has begun to use LLMs to automate parts of the PDDL creation process. However, these methods still require various degrees of expert input. We present NL2Plan, the first domain-agnostic offline LLM-driven planning system. NL2Plan uses an LLM to incrementally extract the necessary information from a short text prompt before creating a complete PDDL description of both the domain and the problem, which is finally solved by a classical planner. We evaluate NL2Plan on four planning domains and find that it solves 10 out of 15 tasks — a clear improvement over a plain chain-of-thought reasoning LLM approach, which only solves 2 tasks. Moreover, in two out of the five failure cases, instead of returning an invalid plan, NL2Plan reports that it failed to solve the task. In addition to using NL2Plan in end-to-end mode, users can inspect and correct all of its intermediate results, such as the PDDL representation, increasing explainability and making it an assistive tool for PDDL creation. 

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  • Disputas: 2025-06-05 13:15 TEMCAS, Temahuset, LinköpingBestill onlineKjøp publikasjonen >>
    Francisco, Marie
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Making Sense of Artificial Intelligence for Global Environmental Governance: Ideas, Power, and Policy Pathways2025Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    This compilation thesis investigates how international actors make sense of the roles of artificial intelligence (AI) systems in environmental policy in their broader geopolitical context. Sense-making refers to the processes by which actors understand, describe, and relate to a phenomenon. In this work, I take ideas as an important tool through which sense-making occurs. I rely on the tools developed by discursive institutionalism to explore ideational power. AI is often defined as a general-purpose technology. This means that there is a variety of ways AI can be used, developed, with multiple opportunities and risks. As such, “AI” can be defined, steered, regulated, utilised and developed in a multitude of ways with a variety of governance implications. As a strong component of policymaking and institutions, ideas suggest (1) practical suggestions for action to (2) defined problems, and (3) what values and parameters should be considered. Ideas are consequently important factors in how AI is made sense of, both as a tool and as an object of environmental governance.

    To explore how AI is made sense of in environmental policy, I focus on how international actors construe their ideas about AI in and for environmental governance (Paper I, Paper II, and Paper III). In addition, I explore how these ideas reflect broader geopolitical dynamics, in particular the power relations and the climate security perspectives that are upheld by them (Paper III and Paper IV). Finally, I seek to identify potential shortcomings and suggest some path forward to make sure the governance of AI will truly support sustainability transformation. This is done by exploring how researchers working with or on AI understand sustainability within responsible AI discussions (Paper V). Overall, I pay attention to ideas about AI -both as a tool and as an object of global environmental governance- and the broader discursive, institutional and geopolitical context within which they are constituted.

    This research has a theoretical and an empirical contribution. Theoretically, it contributes to the discursive institutionalist literature by using AI as a case to explore three features of ideational power: power through, in and over ideas, paying particular attention to what ideals and perceived challenges motivate the use or governance of AI, and how these ideas are articulated within broader institutional, geopolitical and discursive contexts. Empirically, this research provides an overview of different ideas linking AI and global environmental governance, with a particular focus on climate policy.

    Delarbeid
    1. AI and the governance of sustainable development. An idea analysis of the European Union, the United Nations, and the World Economic Forum
    Åpne denne publikasjonen i ny fane eller vindu >>AI and the governance of sustainable development. An idea analysis of the European Union, the United Nations, and the World Economic Forum
    2023 (engelsk)Inngår i: Environmental Science and Policy, ISSN 1462-9011, E-ISSN 1873-6416, Vol. 150, artikkel-id 103590Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    This paper presents an idea analysis of AI in the policy documents and reports of the United Nations, the European Union, and the World Economic Forum. The three organisations expect AI to contribute to sustainability and a prosperous future with better data analysis, greater amounts of quantitative knowledge, and by making economic and social activities less wasteful and more energy efficient. Several challenges are also named: ethics, human rights, cybersecurity, access to reliable data, transparency, and the digital gap. The solutions presented are multi-stakeholder collaboration, cohesive but flexible governance frameworks, but also taking the lead to push for ethical and value-based AI and making sure AI is sustainable. Ideas about AI appear to stem from discourses of ecological modernisation and green governmentality. This framing turns political and structural challenges into technical issues to be solved with more data, greater collaboration, and technical progress. The similarities in ideas between the EU, the UN, and the World Economic Forum also suggest that ideas about AI and sustainable development have reached discourse institutionalisation. Ideas about AI are therefore likely to reinforce already existing institutional and discursive settings.

    sted, utgiver, år, opplag, sider
    Elsevier, 2023
    Emneord
    Idea analysis; Artificial intelligence; Sustainable development; Global environmental governance; Discourse
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-198096 (URN)10.1016/j.envsci.2023.103590 (DOI)001082779500001 ()
    Tilgjengelig fra: 2023-09-25 Laget: 2023-09-25 Sist oppdatert: 2025-04-29
    2. Artificial intelligence for environmental security: national, international, human and ecological perspectives
    Åpne denne publikasjonen i ny fane eller vindu >>Artificial intelligence for environmental security: national, international, human and ecological perspectives
    2023 (engelsk)Inngår i: Current Opinion in Environmental Sustainability, ISSN 1877-3435, E-ISSN 1877-3443, Vol. 61, artikkel-id 101250Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Scientists and decision-makers recognise artificial intelligence (AI) as a potential tool to solve sustainability issues. However, AI solutions can be leveraged for different ends and through different means. This paper presupposes that this process is contingent upon overarching environmental security discourses. It reviews how the use of AI as presented in the literature fits into national, international, human and ecological security perspectives. A national climate security discourse could emphasise military uses of AI and its role in propaganda and misinformation. The international security discourse suggests that international organisations can take advantage of AI to conduct their mission. However, transnational companies can also benefit from AI, with potential negative outcomes on consumption and resource extraction. Public–private collaboration for military AI grants transnational companies and states tools to hinder environmental movements. A human security discourse emphasises the role of AI in reaching the sustainable development goals but should consider potential power imbalances to prevent inequalities. Finally, an ecological understanding of climate security emphasises the role of algorithms in shaping our vision of the environment, and how it potentially estranges us from other cosmologies and the environmental impact of AI. This reflection opens avenues to explore the interplay between AI, geopolitics and environmental protection.

    sted, utgiver, år, opplag, sider
    Elsevier, 2023
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-191131 (URN)10.1016/j.cosust.2022.101250 (DOI)000960509100001 ()2-s2.0-85146452832 (Scopus ID)
    Tilgjengelig fra: 2023-01-19 Laget: 2023-01-19 Sist oppdatert: 2025-04-29bibliografisk kontrollert
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  • Keating, Thomas P.
    et al.
    Linköpings universitet, Institutionen för tema, Tema teknik och social förändring. Linköpings universitet, Filosofiska fakulteten.
    Storm, Anna
    Linköpings universitet, Institutionen för tema, Tema teknik och social förändring. Linköpings universitet, Filosofiska fakulteten.
    Writing the Forsmark Key Information File: Concluding Report2025Rapport (Annet (populærvitenskap, debatt, mm))
    Abstract [en]

    Countries with nuclear facilities are considering ways to safely store radioactiveleftovers from their nuclear activities over long timescales, including spentnuclear fuel. In Sweden, this work has come relatively far with the constructionphase now beginning for a deep geological repository for spent nuclear fuel at Forsmark. In parallel to the development of storage technologies, work is being carried out internationally to develop ways of communicating the long-term hazards of the radioactive remains to future generations. One such approach for communicating information about repositories and their content is called the Key Information File (KIF), a concept advanced through international expert groupsled by the Nuclear Energy Agency (NEA) within the Organisation for Economic Co-operation and Development (OECD).

    This is the concluding report about the work to write a Key Information File for the prospective Forsmark Spent Fuel Repository, in a project commissioned by the Swedish Nuclear Fuel and Waste Management Company (SKB) over theperiod 2021-2024. It outlines project activities, insights gained, and recommendations for further work. In the report, it is argued: (1) for the KIF tosuccessfully work as tool for information transfer to future generations means accepting it is a document aimed at the widest possible audience, and therefore must be presented in a manner open to various readers; (2) that there is a need for a mechanism that supports the continuous renewal of the KIF, and here the projectuniquely proposes the SHIRE method, which stands for Share-Imagine-Renew; and (3) that the KIF also has an important role to play in contemporary conversations around memory transfer concerning nuclear waste repositories. This is because the work to rewrite a given KIF will in itself form a social practice, which could keep complex and critical questions about the memory of underground repositories relevant through time.

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  • Gustavson, Stefan
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Medie- och Informationsteknik. Linköpings universitet, Tekniska fakulteten.
    Noise is Beautiful: Part 1: Procedural textures2025 (oppl. 1st (2025-04-24))Bok (Annet (populærvitenskap, debatt, mm))
    Abstract [en]

    Ever since the advent of computer graphics, procedural generation of content has been part of its diverse toolbox. At first, its only field of application was in off-line, software rendering, because CPUs didn’t have enough processing power to render procedural content in real time, and hardware acceleration had its development focus put elsewhere. In recent years, however, we have seen an introduction of massively parallel and programmable graphics hardware with absolutely astoun­ding processing power. This means that procedural methods can now be quite useful even in real time rendering, and there is renewed interest in the field.

    The subject is deeply fascinating to me: challenging but rewarding, visually creative in a hands-on manner, and fun. Alongside my academic work in the field, it has been an enjoyable hobby over the years.

    It’s not a universal tool, far from it, but it deserves to be considered. Like with all tools, it’s useful to know about its capabilities as well as its limitations so that you can make an informed decision on what to use for a particular task.

    This book aims at teaching you how to create procedural content, to give you the clues you need in order to decide when to use procedural methods, and also to know when you are better off leaving this particular creative tool in the drawer.

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  • Disputas: 2025-06-04 13:00 Berzeliussalen, LinköpingBestill onlineKjøp publikasjonen >>
    Hörlin, Erika
    Linköpings universitet, Institutionen för biomedicinska och kliniska vetenskaper, Avdelningen för klinisk kemi och farmakologi. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Närsjukvården i centrala Östergötland, Akutkliniken i Linköping.
    Assessing Frailty in the Emergency Department: Feasibility and Performance of the Clinical Frailty Scale in a Swedish context2025Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    With increasing age, the risk of frailty rises due to deterioration of several physiological systems, reducing the body’s reserve capacity. Recognising this vulnerability during care encounters is important both for understanding prognosis and recovery goals, and for planning care to reduce adverse outcomes.

    Traditional emergency department (ED) risk stratification methods often fail to detect risks related to frailty, which is why interest in incorporating frailty assessment in EDs has grown. Several instruments have been developed, including the Clinical Frailty Scale (CFS). The CFS has been evaluated across many specialties and is recommended for use in the ED. However, no such research has been conducted in Swedish EDs, and studies under real clinical conditions remain limited.

    Therefore, this thesis aims to examine whether the CFS is a useful tool for assessing frailty in older ED patients in Sweden. Specifically, we sought to evaluate its interrater reliability, prognostic accuracy, feasibility and the perspectives of patients.Study I was an observational study assessing IRR by collecting independent CFS assessments from the physician, registered nurse, and assistant nurse responsible for the patient. IRR was assessed in 100 patients, with 300 assessments conducted. IRR was moderate to good, with an ICC of 0.78 (95% CI 0.72–0.84).

    Study II examined the prognostic value of the CFS by collecting staff-assessed CFS scores for 1840 older patients. The primary outcome was 30-day mortality, compared between patients with and without frailty. We found that 30-day mortality was significantly higher in patients with frailty compared to those considered robust (7.9% vs 0.9%). Frailty was independently associated with 30-day mortality, with an odds ratio of 6.0 (95% CI 3.0–12.2) after adjusting for confounding factors.

    Study III employed a mixed methods design to examine the feasibility of the CFS in an ED setting. We collected data on 4235 ED visits and explored staff experiences through a questionnaire. The overall assessment completion rate was 47%, with more completed in older age groups. The most frequently reported barrier to assessment was high workload. Staff generally perceived the CFS to be relevant, although some questioned its benefits for patients in the ED.

    Study IV had a qualitative design and included video-recorded CFS assessments and interviews with patients. A thematic analysis was conducted. Most older patients perceived frailty screening as positive or indifferent, though the experience could further benefit from a better understanding of the assessment’s purpose and consequences. Patients emphasised the importance of relationship-oriented communication, influencing their willingness to share information about their lives.

    The CFS demonstrates moderate to good IRR and a strong association with mortality, supporting its usefulness in the ED. However, barriers such as high ED workload and mixed staff perceptions regarding its relevance to ED care impact routine use. Older patients generally respond positively to CFS while it is indicated that it can be further improved with clearer explanations of its purpose and potential consequences.

    Delarbeid
    1. Inter-rater reliability of the Clinical Frailty Scale by staff members in a Swedish emergency department setting
    Åpne denne publikasjonen i ny fane eller vindu >>Inter-rater reliability of the Clinical Frailty Scale by staff members in a Swedish emergency department setting
    Vise andre…
    2022 (engelsk)Inngår i: Academic Emergency Medicine, ISSN 1069-6563, E-ISSN 1553-2712, Vol. 29, nr 12, s. 1431-1437Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Introduction As frailty among the elderly is receiving increasing attention in emergency departments (EDs) around the world, the use of frailty assessment tools is growing. An often used such tool is the Clinical Frailty Scale (CFS), whose inter-rater reliability has been sparingly investigated in ED settings. No inter-rater reliability study regarding CFS has previously been performed within the Scandinavian ED context. The primary aim of this study was to evaluate the inter-rater reliability of the CFS in a Swedish ED setting. Methods This was a prospective observational study conducted at three Swedish EDs. Patients &gt;= 65 years were independently assessed with CFS by their responsible physician, registered nurse, and assistant nurse. Demographic information for each assessor was collected, along with frailty status (frail/not frail) on the basis of clinical judgment. Inter-rater reliability was calculated using intraclass correlation coefficient (ICC), whereas agreement of frailty assessed by CFS (dichotomized between frail/not frail, cutoff at &gt;= 5 points) versus solely by clinical judgment was calculated by using cross-tabulation. Results One-hundred patients were included. We found inter-rater reliability to be moderate to good (ICC 0.78, 95% confidence interval [CI] 0.72-0.84), regardless of whether the care team included an emergency physician (ICC 0.74, 95% CI 0.62-0.83) or an intern/resident from another specialty (ICC 0.83, 95% CI 0.74-0.89). The agreement of clinically judged frailty compared to frailty according to CFS was 84%. In the opposing cases, staff tended to assess patients as frail to a higher extent using clinical judgment than by applying CFS on the same patient. Conclusions The CFS appears to have a moderate to good inter-rater reliability when used in a clinical ED setting. When guiding clinical decisions, we advise that the CFS score should be discussed within the team. Further research needs to be performed on the accuracy of clinical judgment to identify frailty in ED patients.

    sted, utgiver, år, opplag, sider
    Wiley, 2022
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-189772 (URN)10.1111/acem.14603 (DOI)000870039100001 ()36200372 (PubMedID)2-s2.0-85139988797 (Scopus ID)
    Tilgjengelig fra: 2022-11-08 Laget: 2022-11-08 Sist oppdatert: 2025-04-28bibliografisk kontrollert
    2. Frailty is associated with 30-day mortality: a multicentre study of Swedish emergency departments
    Åpne denne publikasjonen i ny fane eller vindu >>Frailty is associated with 30-day mortality: a multicentre study of Swedish emergency departments
    Vise andre…
    2024 (engelsk)Inngår i: Emergency Medicine Journal, ISSN 1472-0205, E-ISSN 1472-0213, Vol. 41, nr 9, s. 514-519Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Background Older patients living with frailty have an increased risk for adverse events. The Clinical Frailty Scale (CFS) is a 9-point frailty assessment instrument that has shown promise to identify frail emergency department (ED) patients at increased risk of adverse outcomes. The aim of this study was to investigate the association between CFS scores and 30-day mortality in an ED setting when assessments are made by regular ED staff.Method This was a prospective multicentre observational study carried out between May and November 2021 at three EDs in Sweden, where frailty via CFS is routinely assessed by ED staff. All patients &gt;= 65 years of age were eligible for inclusion. Mortality at 7, 30 and 90 days, admission rate, ED and hospital length of stay (LOS) were compared between patients living with frailty (CFS &gt;= 5) and robust patients. Logistic regression was used to adjust for confounders.Results A total of 1840 ED visits of patients aged &gt;= 65 years with CFS assessments done during the study period were analysed, of which 606 (32.9%) were patients living with frailty. Mortality after the index visit was higher in patients living with frailty at 7 days (2.6% vs 0.2%), 30 days (7.9% vs 0.9%) and 90 days (15.5% vs 2.4%). Adjusted ORs for mortality for those with frailty compared with more robust patients were 9.9 (95% CI 2.1 to 46.5) for 7-day, 6.0 (95% CI 3.0 to 12.2) for 30-day and 5.7 (95% CI 3.6 to 9.1) 90-day mortality. Patients living with frailty had higher admission rates, 58% versus 36%, a difference of 22% (95% CI 17% to 26%), longer ED LOS, 5 hours:08 min versus 4 hours:36 min, a difference of 31 min (95% CI 14 to 50), and longer in-hospital LOS, 4.8 days versus 2.7 days, a difference of 2.2 days (95% CI 1.2 to 3.0).Conclusion Patients living with frailty, had significantly higher mortality and admission rates as well as longer ED and in-hospital LOS compared with robust patients. The results confirm the capability of the CFS to risk stratify short-term mortality in older ED patients.Trial registration number NCT04877028.

    sted, utgiver, år, opplag, sider
    BMJ PUBLISHING GROUP, 2024
    Emneord
    frailty; emergency department; triage; geriatrics; clinical assessment
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-206308 (URN)10.1136/emermed-2023-213444 (DOI)001278779500001 ()39053972 (PubMedID)
    Merknad

    Funding Agencies|Region Ostergotland [RO-965951]

    Tilgjengelig fra: 2024-08-15 Laget: 2024-08-15 Sist oppdatert: 2025-04-28bibliografisk kontrollert
    3. Is the clinical frailty scale feasible to use in an emergency department setting? A mixed methods study
    Åpne denne publikasjonen i ny fane eller vindu >>Is the clinical frailty scale feasible to use in an emergency department setting? A mixed methods study
    Vise andre…
    2023 (engelsk)Inngår i: BMC Emergency Medicine, E-ISSN 1471-227X, Vol. 23, nr 1, artikkel-id 124Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Background: The Clinical Frailty Scale (CFS) is a frailty assessment tool used to identify frailty in older patients visitingthe emergency department (ED). However, the current understanding of how it is used and accepted in ED clinicalpractice is limited. This study aimed to assess the feasibility of CFS in an ED setting.

    Methods :This was a prospective, mixed methods study conducted in three Swedish EDs where CFS had recentlybeen introduced. We examined the completion rate of CFS assessments in relation to patient- and organisationalfactors. A survey on staff experience of using CFS was also conducted. All quantitative data were analyseddescriptively, while free text comments underwent a qualitative content analysis.

    Results: A total of 4235 visits were analysed, and CFS assessments were performed in 47%. The completion rate exceeded 50% for patients over the age of 80. Patients with low triage priority were assessed to a low degree (24%). There was a diurnal variation with the highest completion rates seen for arrivals between 6 and 12 a.m. (58%). The survey response rate was 48%. The respondents rated the perceived relevance and the ease of use of the CFS with a median of 5 (IQR 2) on a scale with 7 being the highest. High workload, forgetfulness and critical illness were rankedas the top three barriers to assessment. The qualitative analysis showed that CFS assessments benefit from a clearroutine and a sense of apparent relevance to emergency care.

    Conclusion: Most emergency staff perceived CFS as relevant and easy to use, yet far from all older ED patientswere assessed. The most common barrier to assessment was high workload. Measures to facilitate use may includeclarifying the purpose of the assessment with explicit follow-up actions, as well as formulating a clear routine for the assessment.

    Registration: The study was registered on ClinicalTrials.gov 2021-06-18 (identifier: NCT04931472).

    sted, utgiver, år, opplag, sider
    BioMed Central (BMC), 2023
    Emneord
    Clinical frailty scale; Feasibility; Frailty; Implementation; Emergency medicine; Geriatric medicine; Mixed methods
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-198798 (URN)10.1186/s12873-023-00894-8 (DOI)37880591 (PubMedID)
    Merknad

    Funding: Open access funding provided by Linköping University

    Tilgjengelig fra: 2023-10-30 Laget: 2023-10-30 Sist oppdatert: 2025-04-28
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  • Disputas: 2025-05-30 13:15 K3, Kåkenhus, NorrköpingBestill onlineKjøp publikasjonen >>
    Lemetti, Anastasia
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Kommunikations- och transportsystem. Linköpings universitet, Tekniska fakulteten.
    Enhancing Air Traffic Management: Weather and Controller Workload Challenges2025Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Air Traffic Management (ATM) faces significant challenges in ensuring efficiency, safety, and sustainability. Among these, weather conditions and Air Traffic Controller (ATCO) workload play crucial roles in overall system performance. Adverse weather frequently disrupts operations, leading to inefficient flight trajectories, increased fuel consumption, and environmental impact. It also elevates ATCO workload, thereby complicating ATCOs’ ability to maintain safe and efficient air traffic flow. This thesis explores data-driven and analytical approaches to address these challenges, focusing on the impact of weather on flight efficiency, airspace capacity, and ATCO scheduling in remote tower centers. Additionally, it examines ATCO workload prediction using behavioral and physiological data. The study covers applications in airspace capacity management, staff scheduling, and ATCO workload assessment.

    The thesis examines historical flight and weather data from Stockholm Arlanda and Gothenburg Landvetter airports over a two-year period (2019–2020), revealing persistent inefficiencies in arrival operations despite the overall reduction in traffic during the COVID-19 pandemic. It presents a methodology grounded in statistical analysis to identify the key factors influencing arrival performance, with particular emphasis on the impact of adverse weather conditions and traffic intensity. The proposed approach systematically determines the most influential variables affecting arrival performance in both the horizontal and vertical flight dimensions.

    Adverse weather conditions, such as convective weather, can lead to restrictions on aircraft movements, reduce available routes, and necessitate adjustments in ATM strategies. As a result, understanding and predicting weather-related impacts on airspace capacity is essential for optimizing air traffic flow and minimizing delays. In this thesis, we develop a methodology, based on the continuous maxflow/mincut theory, to estimate reductions in Air Traffic Control (ATC) sector capacity due to predicted convective weather activity. The uncertainty in meteorological forecasts is quantified using Ensemble Weather Forecasting. We demonstrate the application of this methodology for assessing congestion in ATC sectors, using a realistic sector and a full sector configuration as examples. Additionally, we introduce a probabilistic framework for presenting congestion status, aimed at supporting decision-making processes at the Flow Management Position.

    The thesis presents probabilistic models that incorporate the impact of adverse weather conditions into a Mixed-Integer Linear Programming framework for ATCO shift scheduling in remote and conventional towers. Building on previous project developments, these models specifically address the influence of weather on ATCO operations in remote towers. Probabilistic weather products are used to generate ensembles of staffing solutions, enabling the derivation of probability distributions for the required number of ATCOs. The modeling approach leverages recently developed techniques to tackle challenges associated with weather uncertainty. The proposed solutions are validated using historical flight and weather data from five Swedish airports designated for future remote operation.

    The final part of this thesis focuses on developing unobtrusive methods for predicting ATCO workload by exploring the feasibility of non-intrusive data collection techniques combined with machine learning algorithms. Eye-tracking data, previously identified as a promising indicator of ATCO workload, were collected from controllers in simulated environments and used as predictive features. Subjective workload assessments, based on self-reported Cooper-Harper scale ratings, serve as label variables. Multiple machine learning models are evaluated for workload prediction, and feature selection techniques are applied to identify a minimal yet effective set of eye-tracking features. This approach provides a seamless, non-intrusive means of continuously assessing workload, making it a valuable tool for both research and operational applications in ATC environments.

    By addressing critical challenges in ATM, this thesis contributes to a safer, more efficient, and environmentally sustainable air transport system. The findings of this thesis have significant implications for the future of ATM, particularly in an era of increasing air traffic demand and evolving weather challenges. The integration of data-driven techniques, optimization, and probabilistic modeling offers a powerful framework for improving decision-making in ATM. The methodologies proposed in this thesis can serve as a foundation for future research and industry applications, enabling continuous improvements in ATM performance and resilience against external disruptions.

    Delarbeid
    1. Identification of Significant Impact Factors on Arrival Flight Efficiency within TMA
    Åpne denne publikasjonen i ny fane eller vindu >>Identification of Significant Impact Factors on Arrival Flight Efficiency within TMA
    Vise andre…
    2020 (engelsk)Konferansepaper, Publicerat paper (Fagfellevurdert)
    Abstract [en]

    An important step towards improving the flight performance within Terminal Maneuvering Area (TMA) is the identification of the factors causing inefficiencies. Without knowing which exact factors have high impact on which performance indicators, it is difficult to identify which areas could be improved. In this work, we quantify the flight efficiency using average additional time in TMA, average time flown level and additional fuel consumption associated with the inefficient flight profiles. We apply statistical learning methods to assess the impact of different weather phenomena on the arrival flight efficiency, taking into account the current traffic situation. We utilize multiple data sources for obtaining both historical flight trajectories and historical weather measurements, which facilitates a comprehensive analysis of the variety of factors influencing TMA performance. We demonstrate our approach by identifying that wind gust and snow had the most significant impact on Stockholm Arlanda airport arrivals in 2018

    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-169123 (URN)
    Konferanse
    ICRAT 2020
    Tilgjengelig fra: 2020-09-09 Laget: 2020-09-09 Sist oppdatert: 2025-04-28bibliografisk kontrollert
    2. Arrival flight efficiency in pre- and post-Covid-19 pandemics
    Åpne denne publikasjonen i ny fane eller vindu >>Arrival flight efficiency in pre- and post-Covid-19 pandemics
    2023 (engelsk)Inngår i: Journal of Air Transport Management, ISSN 0969-6997, E-ISSN 1873-2089, Vol. 107, artikkel-id 102327Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Covid-19 pandemic affected aviation severely, resulting in unprecedented reduction of air traffic. While aviation is slowly re-gaining traffic volumes, we use the opportunity to study the arrival performance in the Terminal Maneuvering Area (TMA) in non-congested scenarios. Applying flight efficiency and environmental performance indicators (PIs) to the historical data of arrivals to Stockholm Arlanda and Gothenburg Landvetter airports, we discover noticeable inefficiencies, despite significant reduction of traffic intensity. We analyze the impact of such factors as weather and traffic intensity on arrival efficiency in isolated scenarios when only one factor dominates: isolated scenario with low traffic and isolated scenario with good weather conditions. Our analysis uncovers that weather has a stronger influence than traffic intensity on the vertical efficiency, while traffic intensity has stronger effect on the lateral efficiency. Impact of traffic intensity on the lateral efficiency might be explained by frequent hold-on patterns and flight trajectory extensions due to vectoring in high traffic conditions. Further investigation is needed to explain weather and vertical/lateral efficiency correlations, the conclusions might be country-specific.

    sted, utgiver, år, opplag, sider
    ELSEVIER SCI LTD, 2023
    Emneord
    TMA performance; Arrival flight efficiency; Continuous descent operations; Fuel consumption; Key performance indicators; Weather impact
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-191358 (URN)10.1016/j.jairtraman.2022.102327 (DOI)000901804500001 ()36408128 (PubMedID)
    Merknad

    Funding Agencies|SESAR Joint Undertaking under the European Union [783287]; Swedish Transport Agency (Transportstyrelsen); Swedish Transport Administration (Trafikverket)

    Tilgjengelig fra: 2023-01-30 Laget: 2023-01-30 Sist oppdatert: 2025-04-28
    3. Probabilistic Analysis of Airspace Capacity in Adverse Weather Scenarios
    Åpne denne publikasjonen i ny fane eller vindu >>Probabilistic Analysis of Airspace Capacity in Adverse Weather Scenarios
    Vise andre…
    2022 (engelsk)Konferansepaper, Publicerat paper (Fagfellevurdert)
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-209419 (URN)
    Konferanse
    Sesar Innovation Days 2022
    Tilgjengelig fra: 2024-11-12 Laget: 2024-11-12 Sist oppdatert: 2025-04-28
    4. Integrating weather impact in air traffic controller shift scheduling in remote and conventional towers
    Åpne denne publikasjonen i ny fane eller vindu >>Integrating weather impact in air traffic controller shift scheduling in remote and conventional towers
    Vise andre…
    2022 (engelsk)Inngår i: EURO Journal on Transportation and Logistics, ISSN 2192-4376, E-ISSN 2192-4384, Vol. 11Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Weather affects the work of air traffic controllers, however, for staff scheduling in Remote Tower Centers (RTCs) it has not been taken into account. We study the impact of various weather phenomena on air traffic controller (ATCO) taskload through structured interviews with ATCOs. We deduce taskload-driven impact factors and the corresponding thresholds for the intensity of the weather phenomena at several Swedish airports. To account for the uncertainty in the weather prediction, we obtain probabilistic weather data from Ensemble Prediction Systems (EPSs). Then we adjust our prior Mixed Integer Programming (MIP) model for RTC staff scheduling to account for uncertain impactful weather occurrences and yield a distribution for the necessary number of ATCOs for RTC staff scheduling. Our framework can be used for conventional towers as well. We quantify the impact of weather by comparing the number of controllers necessary to operate at five Swedish airports from a remote tower during two example days in 2020, with and without taking weather events into account. In our calculations we use historical weather and flight data to show that ignoring weather impact may lead to significant understaffing at a RTC.

    sted, utgiver, år, opplag, sider
    Elsevier, 2022
    Emneord
    ATCO workload; Weather; RTC staff scheduling
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-185424 (URN)10.1016/j.ejtl.2022.100076 (DOI)000795089300003 ()
    Merknad

    Funding Agencies|Swedish Transport Administration (Trafikverket); SESAR JU under the European Union [783287]

    Tilgjengelig fra: 2022-06-03 Laget: 2022-06-03 Sist oppdatert: 2025-04-28
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  • Trygg, Kristina
    et al.
    Linköpings universitet, Institutionen för tema, Tema teknik och social förändring. Linköpings universitet, Filosofiska fakulteten.
    Grundel, Ida
    Linköpings universitet, Institutionen för tema, Tema teknik och social förändring. Linköpings universitet, Filosofiska fakulteten.
    Styrning av mobilitetshubbar: En handbok för svenska kommuner2024Rapport (Annet vitenskapelig)
    Abstract [sv]

    I svenska kommuner har mobilitetshubbar kommit att bli en del av den strategiska planeringen för en hållbar stad. Som ett led i den strategiska planeringen har kommunerna kommit att experimentera genom att testa nya lösningar. Här har mobilitetshubbar vuxit fram som en ny trend för att skapa attraktiva städer och mer hållbara resor. En mobilitetshubb kan beskrivas som en plats där olika färdmedel är paketerade i kombination med olika tjänster för att på så sätt förenkla för ett hållbart resande. I Sverige är planeringen och implementeringen av mobilitetshubbar ett relativt nytt fenomen. Det har dock genomförts ett fåtal pilotstudier och det finns ett antal olika exempel där implementering har skett. I denna bok visar vi hur fyra kommuner, på olika sätt, planerar för en hållbar mobilitet genom att studera mobilitetshubbar. Vi vill med denna bok inspirera planerare på kommunal och regional nivå, samt andra samhällsaktörer som vill leda förändring genom att testa (experimentera) för en hållbar energi- och mobilitetsomställning.

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  • Disputas: 2025-05-28 09:00 Jordan/Fermi, F-building, LinköpingBestill onlineKjøp publikasjonen >>
    Hjort, Victor
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Thermoelectric properties of CrN alloy thin films2025Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    A thermoelectric material can be used to convert heat to electricity, and vice versa, all without moving parts. Thermoelectric devices can be used for a multitude of applications, such as thermoelectric generators (TEGs) and Peltier heaters/coolers. TEGs can be used to generate electricity from e.g. waste heat, and small and efficient Peltier coolers could have a use in microelectronics. The lack of moving parts means that thermoelectric devices generally are robust.

    Transition metal nitrides are versatile, durable, and have found use in many different applications. CrN, for instance, is known for its hardness, corrosion resistance, near room-temperature magnetic phase transition as well as its thermoelectric properties. Especially crystalline CrN has interesting thermoelectric properties, including a high power-factor and low thermal conductivity. These properties are essential for the constituent materials of thermoelectric devices. For durability, the stability and mechanical properties of CrN would be a bonus. The thermoelectric properties of CrN have a strong correlation to the stoichiometry, which then becomes crucial to control.

    The focus of this thesis is on the thermoelectric properties of CrN, with and without alloying transition metals V and Mo. Doping and alloying can help change properties, both electrical and thermal. I have grown thin films of CrN with and without alloying elements, using reactive magnetron sputtering. Film growth using this technique happens far from thermodynamic equilibrium and thus, not all aspects are easy to control, stoichiometry being one. The films were grown on c-plane sapphire (Al2O3 (0001)) substrates.

    I investigated thin, epitaxial films of CrMoVN, i.e. CrN thin films co-doped with Mo and V. They were grown on c-plane sapphire substrates, which allows the rock-salt cubic structured CrN to be grown epitaxially, albeit with a non-negligible strain. I investigated the effect of co-doping on phase composition and thermoelectric properties. While the effects of singly doped films (CrVN and CrMoN) were similar to other reports, co-doping with V and Mo resulted in the retention of the rock-salt cubic phase at much higher Mo-content than what has previously been reported. Furthermore, I tackled the issue with stoichiometry, motivated by discrepancies in literature correlating thermoelectric properties and stoichiometry of CrN. After growing sets of thin films of CrN, some epitaxial and some mix-phased, the samples were annealed in ammonia environment to approach the thermodynamic equilibrium of Cr:N = 1:1. The films that were closest to stoichiometry before annealing turned insulator – in line with theory and some articles. The films with larger under-stoichiometry got significantly improved thermoelectric properties, one by as much as 900%.   

    Delarbeid
    1. Phase Composition and Thermoelectric Properties of Epitaxial CrMoVN Thin Films
    Åpne denne publikasjonen i ny fane eller vindu >>Phase Composition and Thermoelectric Properties of Epitaxial CrMoVN Thin Films
    Vise andre…
    2023 (engelsk)Inngår i: Advanced Energy & Sustainability Research, E-ISSN 2699-9412, Vol. 4, nr 12, artikkel-id 2300119Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Thin films of CrMoVN are deposited on c-plane sapphire (Al2O3 (0001)) by direct current reactive magnetron sputtering, to investigate the effects of Mo and V addition to CrN-based films. All films grow epitaxially, but Mo incorporation affects the crystal structure and nitrogen content. All films in the CrMoVN series are understoichiometric in nitrogen, but largely retain the NaCl B1 structure of stoichiometric CrN films. Addition of vanadium increases the phase-stability range of the cubic phase, allowing for higher solubility of Mo than what has previously been reported for cubic CrN. The Seebeck coefficient and electrical resistivity are greatly affected by the alloying, showing a decrease of the Seebeck coefficient along with a decrease in resistivity. Cr0.83Mo0.11V0.06Nz shows a 70% increase in power factor (S2 sigma = 0.22 mW m-1 K-2) compared to the reference CrNz (S2 sigma = 0.13 mW m-1 K-2). Thermoelectric (TE) materials are in use in several applications, but often have too low efficiency. For more widespread use of these materials, fundamental research on TE material system is necessary. In this work, alloying in CrN, with the hope of pushing a material with great promise closer to applications, is investigated.image (c) 2023 WILEY-VCH GmbH

    sted, utgiver, år, opplag, sider
    WILEY, 2023
    Emneord
    alloys; chromium; CrN; epitaxy; nitrides; thermoelectrics; thin films
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-198835 (URN)10.1002/aesr.202300119 (DOI)001080324100001 ()2-s2.0-85171194991 (Scopus ID)
    Merknad

    Funding Agencies|Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University [SFO-Mat-LiU No. 2009 00971]; Knut and Alice Wallenberg foundation through the Wallenberg Academy Fellows program [KAW-2020.0196]; Swedish Research Council (VR) [2021-03826]; Swedish Energy Agency [2022-00213]; IUVSTA through the Medard W. Welch International Scholarship; Swedish Research Council VR-RFI [2019-00191]; Swedish Foundation for Strategic Research [RIF14-0053]

    Tilgjengelig fra: 2023-11-02 Laget: 2023-11-02 Sist oppdatert: 2025-04-25
    2. Influence of Ammonia Annealing on Cr-N Thin Films and Their Thermoelectric Properties
    Åpne denne publikasjonen i ny fane eller vindu >>Influence of Ammonia Annealing on Cr-N Thin Films and Their Thermoelectric Properties
    Vise andre…
    2024 (engelsk)Inngår i: ACS Applied Energy Materials, E-ISSN 2574-0962, Vol. 7, nr 15, s. 6785-6792Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    CrN-based thin films are emerging as thermoelectric materials for energy harvesting. Their thermoelectric properties depend on phase composition and stoichiometry, necessitating control over the nitrogen content and how it affects the phase composition. Here, the effect of high-temperature ammonia annealing on the thermoelectric properties as well as crystal structure of thin films of Cr-N on c-plane sapphire (Al2O3(0001)) was investigated. Single-phase (cubic CrN) and mix-phase (cubic CrN + hexagonal-Cr2N) Cr-N films were annealed in ammonia, converting any secondary phase of hexagonal Cr2N to cubic CrN. The thermoelectric properties of the films that contained a secondary phase of hexagonal (CrN)-N-2 greatly improved upon annealing, with an increase of 900% to 0.5 x 10-3 W m(-1) K-2 for the film annealed at 800 degrees C for 2 h. Annealing of single-phase films of cubic CrN resulted in films with near-insulating electrical properties. For the thermoelectric applications of CrN, ammonia annealing can be beneficial over meticulous deposition control.

    sted, utgiver, år, opplag, sider
    AMER CHEMICAL SOC, 2024
    Emneord
    CrN; thermoelectrics; thin film; ammonia; annealing; chromium
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-206289 (URN)10.1021/acsaem.4c01491 (DOI)001280925300001 ()
    Merknad

    Funding Agencies|Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University (Faculty Grant SFO-Mat-LiU) [2009 00971]; Knut and Alice Wallenberg Foundation through the Wallenberg Academy Fellows program [KAW-2020.0196]; Swedish Research Council (VR) [2021-03826]; Swedish Energy Agency [52740-1]; Swedish Research Council VR-RFI [2019-00191]; Swedish Foundation for Strategic Research [RIF14-0053]

    Tilgjengelig fra: 2024-08-14 Laget: 2024-08-14 Sist oppdatert: 2025-04-25bibliografisk kontrollert
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