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  • Danev, Stefan
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Phantong, Chaichana
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Preliminary study on potential material movement with AGV systems - A case study at Batterifabrik AB2024Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Rapporten är en förstudie som kan använda av Batterifabrik AB när de tar beslut om de ska implementera AGV i deras produktion.

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  • Blomberg, Stefan
    et al.
    Linköping University, Department of Behavioural Sciences and Learning, Psychology. Linköping University, Faculty of Arts and Sciences. Linköping University, Department of Health, Medicine and Caring Sciences. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Medicine Center, Occupational and Environmental Medicine Center.
    Rosander, Michael
    Linköping University, Department of Behavioural Sciences and Learning, Psychology. Linköping University, Faculty of Arts and Sciences.
    Einarsen, Ståle Valvatne
    Department of Psychosocial Science, Faculty of Psychology, University of Bergen, Norway.
    Role ambiguity as an antecedent to workplace bullying: Hostile work climate and supportive leadership as intermediate factors2024In: Scandinavian Journal of Management, ISSN 0956-5221, E-ISSN 1873-3387, Vol. 40, no 2, article id 101328Article in journal (Refereed)
    Abstract [en]

    Previous studies have shown role stress to be an important antecedent of workplace bullying. The present study investigated when and how a long-term effect of role ambiguity on exposure to bullying may be present. Based on the work environment hypothesis, we hypothesized that (a) there is a long-term effect of role ambiguity on exposure of bullying, (b) that this relationship is mediated by hostile work climate, and (c) moderated by supportive leadership. Using a three-wave design, with a time lag of 41–45 months, we showed support for all three hypotheses. The study underscores the importance of clear work-related roles as well as the importance of supportive leadership to prevent the onset of bullying following role stress and hostile climates.

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  • Algotson, Albin
    et al.
    Linköping University, Department of Management and Engineering, Political Science. Linköping University, Faculty of Arts and Sciences.
    Ekholm, David
    Linköping University, Department of Culture and Society, Division of Social Work. Linköping University, Faculty of Arts and Sciences. Linköping University, Department of Culture and Society, Centre for Local Government Studies.
    Kommunal styrning av folkhälsoarbete: I spänningsfältet mellan operativt och strategiskt arbete2024Report (Other academic)
    Abstract [sv]

    Denna rapport handlar om villkor och förutsättningar för folkhälsoarbete i svenska kommuner. Kommunernas roll i folkhälsopolitiken är komplex, föränderlig och saknar tydlig reglering. Samtidigt som rollen är oklar, ansvarar kommunerna för mycket av det som påverkar befolkningens hälsa, såsom skola och utbildning, sociala verksamheter, fritid och stadsplanering. Dessutom möter Sveriges kommuner idag ökade förväntningar när det kommer till att hantera en tilltagande ojämlikhet i hälsa bland barn och unga. I rapporten undersöks de institutionella och organisatoriska villkor som påverkar kommunernas folkhälsoarbete genom en fallstudie av Generation Peps pilotprojekt Pep Kommun.

    Pep Kommun är ett pilotprojekt initierat av Generation Pep, en icke-vinstdrivande organisation. Pilotprojektet syftar till att utveckla och testa insatser för att främja barns och ungas hälsa i sex kommuner. Genom fokusgruppsintervjuer med deltagare från de sex deltagande kommunerna nås en djupare förståelse för de spänningar och ibland skiftande logiker som formar villkoren för hur lokalt folkhälsoarbete kan bedrivas.

    Rapporten visar på en klyfta mellan det strategiska, kommunövergripande arbetet som Pep Kommun haft för ambition att utveckla, och det operativa arbetet med framförallt barn och unga som bedrivs inom ramen för kommunernas välfärdsarbete med skola, fritid och social verksamhet. Framför allt identifieras utmaningar i att implementera och utveckla lokala arbetsformer för folkhälsoarbete i relation till den sektoriserade förvaltningen. Denna utmaning förstås som en spänning mellan den traditionella och sektoriserade välfärdspolitiken visavi den tvärsektoriella folkhälsopolitiken.

    Resultaten innebär inte att tvärsektoriellt och strategiskt folkhälsoarbete är helt skilt ifrån det sektoriserade välfärdsarbetet. Men det innebär att olika delar av kommunal verksamhet med bäring på barn och ungas hälsa vilar på olika traditioner, olika former för styrning, olika professionell kunskap liksom skilda organisatoriska och politiska kontexter. Detta behöver hanteras för att ett tvärsektoriellt och kommungemensamt folkhälsoarbete ska kunna utvecklas.

    Avslutningsvis diskuteras behovet av att förstå den lokala kontexten som en dynamisk spelplan liksom vikten av att hantera förändring istället för att etablera en fixerad ordning för lokalt folkhälsoarbete. Vi menar också att det krävs ett kontinuerligt arbete att skapa klarhet kring vad kommunerna vill med sitt folkhälsoarbete (exempelvis i form av medverkan i Pep Kommun). Därtill menar vi att en större konceptuell klarhet kring vad kommunalt folkhälsoarbete är och förväntas vara måste utvecklas i dialog mellan statliga myndigheter, regioner och kommuner.

    Sammanfattningsvis bidrar rapporten med kunskap om villkor och förutsättning för folkhälsoarbete på kommunal nivå genom att peka på centrala institutionella och organisatoriska spänningar. Samtidigt pekar rapporten på att det finns ett stort behov av att fortsatt – i framtida praktiknära forskning – utveckla förståelsen för lokalt folkhälsoarbete genom att integrera kunskap om interventioner och medicinska aspekter av hälsa, med kontextuell och implementeringsinriktad kunskap om folkhälsoarbetets kommunala styrning och organisering.

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  • Classon, Linus
    Linköping University, Department of Electrical Engineering, Vehicular Systems.
    State of Health measuring of NiMH batteries using simple electronic components.2024Independent thesis Basic level (degree of Bachelor), 14 HE creditsStudent thesis
    Abstract [en]

    The possibility of measuring the state of health of a NiMH battery without doing it in a lab is evaluated, the goal was to see if it was possible to perceive any differences between batteries of different states of health and whether it’s worth further exploring this solution in a more detailed manner. In order to try and extract and analyze the state of health of the batteries a series of tests consisting of discharging batteries at different lengths of times and different resistive loads were made, the voltage of the batteries being captured by a multimeter. The study shows that getting the state of health of a battery with simple components is a possibility and is useful for battery-powered items. Situations where batteries can’t deliver enough energy for the item to function can be prevented by measuring the health of the batteries and then subsequently switching out the batteries if needed.

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  • Molin, Alice
    et al.
    Linköping University, Department of Science and Technology, Media and Information Technology. Linköping University, Faculty of Science & Engineering.
    Johnstone, Julia
    Linköping University, Department of Science and Technology, Media and Information Technology. Linköping University, Faculty of Science & Engineering.
    Space Weather Simulation Model Integration2023Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Space weather is the field within the space sciences that studies how the Earths magnetosphere is influenced by the Sun. The Sun is constantly emitting dangerous radiation and plasma which in some cases can affect or damage the systems on Earth. Scientists have an interest in studying this interaction and therefore visualizations of space weather data are useful. OpenSpace is an interactive software that visualizes the entire known universe with real-time data. OpenSpace supports a range of different visualization methods and techniques, for this work, the relevant visualization tools are field lines and cut planes. GAMERA is a simulation model that simulates a wide range of situations where plasma is subjected to the influence of magnetic fields, the simulations are based on curvilinear grids. This project focuses on implementing data from GAMERA into OpenSpace. OpenSpace already supports a variety of different simulation models, although none that uses curvilinear grids for the data. The curvilinear grid can adapt to the specific shape and geometry of the data, allowing for more accurate data representation. The project aims to create a pipeline for reading data files from simulation runs and visualize it as field lines and cut planes. The files used in this project contain data suitable for volumes and field lines. The method was to first develop a reader to extract and manage desired data from HDF5 files in which the simulation data is stored. The data used to visualize field lines is rendered with an already existing component in OpenSpace. Secondly, a slice operation was developed to extract cut planes from the files containing data for volume visualization, these are then visualized with the help of a component for rendering cut planes which was developed during this work. The work led to a pipeline that reads and manages simulation data from GAMERA and the data is successfully visualized. However, there is room for improvement in color rendering, robustness and level of user interaction during runtime.

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  • Gren, Lisa
    et al.
    Linköping University, Department of Science and Technology, Media and Information Technology. Linköping University, Faculty of Science & Engineering.
    Lindberg, Denny
    Linköping University, Department of Science and Technology, Media and Information Technology. Linköping University, Faculty of Science & Engineering.
    The State of Live Facial Puppetry in Online Entertainment2024Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Avatars are used more and more in online communication, in both games and socialmedia. At the same time technology for facial puppetry, where expressions of the user aretransferred to the avatar, has developed rapidly. Why is it that facial puppetry, despite this,is conspicuous by its absence?

    This thesis analyzes the available and upcoming solutions for facial puppetry, if a com-mon framework or library can exist and what can be done to simplify the process for de-velopers who wants to implement facial puppetry.

    A survey was conducted to get a better understanding of the technology. It showedthat there is no standard yet for how to describe facial expressions, but part of the marketis converging towards a common format. It also showed that there is no existing inter-face that can handle communication with tracking devices or translation between differentexpression formats.

    Several prototypes for recording and streaming facial expression data from differentsources were implemented as a practical test. This was done to evaluate the complexity ofimplementing real-time facial puppetry. It showed that it is not always possible to integratethe available tracking solutions into an existing project. When integration was possible itrequired a lot of work. The best way to get tracking right now seems to be to implement astandalone program for tracking that streams the tracked data to the main application.

    In summary it is the poor integrability of the solutions that makes it problematic forthe developers, together with a wide variety of facial expression formats. A software thatacts like a bridge between the tracking solutions and the game could allow for translationbetween different formats and simplify implementation of support.

    In the future, instead of working towards making all tracking solutions output stan-dardized tracking data, research further how to build a framework that can handle differ-ent configurations.

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  • Sproge, Sofia
    Linköping University, Department of Science and Technology, Media and Information Technology. Linköping University, Faculty of Science & Engineering.
    Night Vision Goggle Simulation in a Mixed Reality Flight Simulator with Seamless Integrated Real World2024Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Night vision goggles (NVGs) are optical devices used to enhance human vision at low light conditions such as nighttime. The image seen through the goggles is brightened but with the consequence of introduced visual limitations and illusions. Because of this, fighter pilots need to undergo proper training with such equipment before operating with them in real-life. An NVG simulation within a Mixed Reality (MR) flight simulator can in theory be used to build the skills needed and directly translate them into real life. In this thesis, an NVG effect was added to a video see-through camera feed(VST) such that a whole NVG simulation could be experienced in an MR flight simulator. Furthermore, a method to seamlessly integrate the VST into the nocturnal virtual world was proposed. By conducting a semi structured interview with an NVG expert, the experienced realism, presence, and training value of the implemented effects were measured. A thematic analysis of the gathered interview data provided insight into the most important themes regarding NVG simulations within an MR flight simulator.

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  • Edepil, Jennie
    et al.
    Linköping University, Department of Health, Medicine and Caring Sciences.
    Elvin, Cecilia
    Linköping University, Department of Health, Medicine and Caring Sciences.
    Konsten att balansera på viktpreventionens sköra lina: En bloggstudie om föräldrars erfarenheter av viktkontroll inom Barnhälsovården i Sverige2023Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Background: Both overweight and underweight risk negative health effects. Obesity is a growing concern and has developed into a bigger health problem than underweight. Nurses in swedishChildren´s health centre reach the majority of all children and their parents and thus have a unique position for detecting weight abnormalities at an early stage.Purpose: To illuminate how parents experienced the interaction with the nurse in Children´s health centre in conjunction with weight control of children.Method: A qualitative blog study with an inductive approach and empirical design. The data is analyzed with qualitative content analysis according to Elo and Kyngäs. A total of 46 blogs wereincluded in the study.Result: The outcome resulted in four categories; Relationships and partnerships, Emotional storms, Anxiety about weight and Strategies for dealing with the situation. The categories further resulted in a total of eleven subcategories. The visits in Children´s health centre was associated with many strong emotions and the communication and social care had a great impact on the parents' experience of the meeting and the weight control.Conclusion: The study can contribute to increased knowledge and understanding around the complexity that exists in connection with weight control in child health care and thus lead to improved experiences for parents. Creating a trusting relationship based on a family-centered approach seems to be the key to success. 

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  • Persson Lidholm, Hillevi
    et al.
    Linköping University, Department of Behavioural Sciences and Learning.
    Gullström, Claudia
    Linköping University, Department of Behavioural Sciences and Learning.
    Lyckoparadoxen: Motsättningen mellan lycka, sociala relationer och användandet av sociala medier2023Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Social relationships are fundamental to the experience of happiness and social media is designed to facilitate these. Paradoxically, the use of social media does not always increasethe experience of happiness. The purpose of the study has therefore been to investigate and increase understanding of how women born in the 70s and 80s feel that their happiness is affected by the use of social media. Six women, aged between 35 and 51, who use social media daily, were recruited via social media. Data were collected via semi-structured interviews and analyzed through Interpretative Phenomenological Analysis (IPA). Four overarching themes were identified - Social belonging, Endless scrolling, Social comparison and Conscious use. The results show that the participants feel that a clear purpose for using social media increases their happiness, simultaneously as the lack of a conscious mindset leads to destructive user behaviors that reduce happiness. The coexistence of positive and negative emotions therefore prevents the participants from feeling long-term and overall happiness when using social media.

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  • Fridahl, Mathias
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Centre for Climate Science and Policy Research, CSPR.
    Handel med utsläppskrediter inom ramen för Sveriges nationella och internationella klimatåtaganden2024Report (Other academic)
    Abstract [sv]

    Sveriges långsiktiga nationella klimatmål är ett av världens mest ambitiösa. Sverige ska nå noll nettoutsläpp av växthusgaser till år 2045. Det ska ske genom att minska utsläppen med minst 85 procent jämfört med 1990. Kvarvarande utsläpp ska kompenseras genom så kallade kompletterande åtgärder, både inhemska åtgärder och internationella klimatsinaster.

    På senare tid har regeringens intresse för internationella klimatinsatser ökat. En delförklaring kan vara att Sveriges ekonomi präglas av en mycket låg koldioxidintensitet. Sverige har en av världens mest klimateffektiva ekonomier, i paritet med Schweiz och Danmark (Gütschow och Pflüger, 2022). Den låga koldioxidintensiteten innebär att marginalkostnaden för klimatåtgärder inom Sveriges territorium i många fall är hög i jämförelse med andra länder. En annan förklaring bakom det svenska intresset för internationella klimatinsatser är Sveriges historiskt stora engagemang i internationell politik. Relativt storleken på Sveriges ekonomi har Sverige en lång historia av att vara världsledande inom klimatrelaterat bistånd och klimatfinansiering. En del av detta engagemang tar sig uttryck genom svenska statens satsningar på internationella klimatinsatser inom ramkonventionen om klimatförändringar. Satsningen består dels av klimatrelaterat bistånd, bilateralt liksom genom stora bidrag till multilaterala fonder som den globala miljöfonden, gröna klimatfonden och anpassningsfonden, dels av Energimyndighetens program för internationella klimatinsatser.

    Parisavtalets Artikel 6 reglerar hur stater kan samarbeta internationellt. Skärningspunkten mellan FN:s reglering av samarbeten under Artikel 6, Sveriges ambitioner inom kompletterande åtgärder för att uppfylla nationella klimatmål och EU:s begräsningar av det svenska handlingsutrymmet är komplex. Denna rapport syftar till att skapa underlag för att förstå om den svenska satsningen på Artikel 6 bidrar till möjligheten att nå de svenska klimatmålen. Rapporten försöker reda ut:

    1. I hur stor utsträckning kan Sverige använda Artikel 6 som kompletterande åtgärd för att nå Sveriges nationella klimatmål givet de begräsningar som ges av EU:s klimatpolitiska rättsakter?
    2. Hur påverkas utrymmet att använda Artikel 6 för att uppnå Sveriges nationella klimatmål av möjligheterna att använda andra kompletterande åtgärder för att uppfylla svenska åtaganden gentemot EU?
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  • Andersson, Per
    et al.
    Linköping University, Department of Behavioural Sciences and Learning, Education and Adult Learning. Linköping University, Faculty of Educational Sciences.
    Ahn, Song-ee
    Linköping University, Department of Behavioural Sciences and Learning, Education and Adult Learning. Linköping University, Faculty of Educational Sciences.
    Johannesen Skonhoft, Hedvig
    OsloMet – Oslo Metropolitan University, Norway.
    Köpsén, Johanna
    Linköping University, Department of Behavioural Sciences and Learning, Education and Adult Learning. Linköping University, Faculty of Arts and Sciences.
    Louw, Arnt
    Aalborg University, Denmark.
    Editorial: Autumn 20232023In: Nordic Journal of Vocational Education and Training, E-ISSN 2242-458X, no 2, p. iii-vArticle in journal (Other academic)
    Abstract [en]

    Welcome to a new issue of the Nordic Journal of Vocational Education and Training(NJVET), which completes volume 13 of our journal. We want to create an activeforum for critical research on vocational and professional education and training,and we are proud that so many researchers in this area choose to submit andpublish their work in this journal. We are also thankful for the work completedby all our anonymous reviewers, whose efforts are invaluable for the quality ofthe research articles that are published.This issue includes five research articles from four Nordic countries: two articles from Norway, one from Finland, one from Sweden, and one written in cooperation between Finland and Denmark – an example of the broad interest in disseminating research findings through NJVET.

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  • Mossberg, Olof Samuel
    Linköping University, Department of Mathematics, Applied Mathematics. Linköping University, Faculty of Science & Engineering.
    Geometry of high dimensional Gaussian data2024Independent thesis Basic level (degree of Bachelor), 14 HE creditsStudent thesis
    Abstract [en]

    Collected data may simultaneously be of low sample size and high dimension. Such data exhibit some geometric regularities consisting of a single observation being a rotation on a sphere, and a pair of observations being orthogonal.

    This thesis investigates these geometric properties in some detail. Background is provided and various approaches to the result are discussed. An approach based on the mean value theorem is eventually chosen, being the only candidate investigated that gives explicit convergence bounds. The bounds are tested employing Monte Carlo simulation and found to be adequate.

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  • Ingerstad, Erica
    et al.
    Linköping University, Department of Electrical Engineering, Computer Vision.
    Kåreborn, Liv
    Linköping University, Department of Electrical Engineering, Computer Vision.
    Planet-NeRF: Neural Radiance Fields for 3D Reconstruction on Satellite Imagery in Season Changing Environments2024Independent thesis Advanced level (degree of Master (Two Years)), 28 HE creditsStudent thesis
    Abstract [en]

    This thesis investigates the seasonal predictive capabilities of Neural Radiance Fields (NeRF) applied to satellite images. Focusing on the utilization of satellite data, the study explores how Sat-NeRF, a novel approach in computer vision, per- forms in predicting seasonal variations across different months. Through compre- hensive analysis and visualization, the study examines the model’s ability to cap- ture and predict seasonal changes, highlighting specific challenges and strengths. Results showcase the impact of the sun on predictions, revealing nuanced details in seasonal transitions, such as snow cover, color accuracy, and texture represen- tation in different landscapes. The research introduces modifications to the Sat- NeRF network. The implemented versions of the network include geometrically rendered shadows, a signed distance function, and a month embedding vector, where the last version mentioned resulted in Planet-NeRF. Comparative evalua- tions reveal that Planet-NeRF outperforms prior models, particularly in refining seasonal predictions. This advancement contributes to the field by presenting a more effective approach for seasonal representation in satellite imagery analysis, offering promising avenues for future research in this domain.

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  • Public defence: 2024-03-19 13:15 K1, NorrköpingOrder onlineBuy this publication >>
    Fürsich, Laura
    Linköping University, The Institute for Analytical Sociology, IAS. Linköping University, Faculty of Arts and Sciences.
    The Urban Tapestry: Essays on the Relationship Between Social Networks and Residential Segregation2024Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Dominant explanations of segregation argue that patterns of spatial residential sorting are shaped by the aggregation of individual residential choices, guided by discrimination, differences in resources, and preference-based explanations of neighborhood ethnic composition. However, research on social networks indicates that social influence can serve as a driver of collective outcomes that result in social organization. I reconsider interactive behavior in line with the sociological literature on networks and social influence to advance the literature on how social contexts shape opportunities for interaction and how the social influence of social contexts may affect residential choices and subsequent segregation. To this end, I present three essays that address: 1) the macro implications of networked behavior in space, 2) the social influence effects of school peers during adulthood, and 3) how social contexts in neighborhoods, particularly in the form of local social infrastructure, modify the effects of social influence. In doing so, I demonstrate that network and institutional effects are empirically observable and show how they operate as mechanisms of segregation.

    In the introductory chapter, I address the emerging literature on social structural sorting and detail how it can benefit from the adoption of an Analytical sociology perspective. In particular, I highlight the importance of considering interactions in space and social contexts and their importance to an understanding of persistent patterns of spatial residential segregation.

    In Essay I, I provide an analytical account of how network features can shape residential segregation. I develop an Agent-based simulation similar to the seminal Schelling model but with the agents embedded in a social network structure. This allows me to experimentally manipulate network homophily, clustering, and degree to measure how each of these network features shapes segregation levels, patterns, and the stability of the social-spatial system. I show that depending on the combination of each of these features, network models can lead to even higher levels of residential sorting, driven by the interactive behavior of agents, than the seminal Schelling model. The results tie in with the classic sociological literature on social networks and highlight the importance of weak ties in tipping a social system into a segregated state.

    Essay II examines the role of social influence among school peers in young adulthood. Scholarship has previously highlighted the role of kin in residential choices. However, there is less evidence about how non-kin ties can affect intra-urban residential choices. Drawing on the push-pull and housing-search model, our hypothesis posits that school peers serve as a potential pool of friends that influence one’s residential decisions. To unravel the dynamics of social influence and selection into neighborhoods, we utilize population register data and employ a cross-cohort design. Using conditional logistic regression models, we see that the influence of school peers from both the 9th and 12th grades affects residential choices during adulthood. Moreover, our analysis demonstrates that various life stages have distinct social foci, but that the persistent influence of school peers remains evident throughout.

    Essay III examines how social contexts can modify social influence effects by providing an opportunity for interaction. We combine population register data with OpenStreetMap data to map the amenity landscape in Stockholm and test whether neighborhood-level infrastructure mitigates tendencies towards white flight behavior. We employ coarsened exact matching to address selection bias into neighborhoods and estimate weighted linear probability regressions to assess the probability of majority group members’ out-mobility. We find that local social amenities located on the city block can indeed reduce tendencies towards white flight behavior. However, with increasing amenity density in the neighborhoods, majority group members become more likely to engage in white flight. We conclude that amenity density allows neighborhood residents to sort into different establishments, which does not promote intergroup contact. However, if amenities are local, which presumably facilitates frequent contact with neighbors, opportunities for interaction can reduce intolerant behavior, highlighting how social contexts are important mechanisms of segregation.

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  • Public defence: 2024-04-12 13:00 Belladonna, LinköpingOrder onlineBuy this publication >>
    Mattelin, Erica
    Linköping University, Department of Biomedical and Clinical Sciences, Barnafrid. Linköping University, Faculty of Medicine and Health Sciences.
    Resilience, mental health, and exposure to violence among individuals with former or current experiences of being a refugee in Sweden: quantitative and qualitative studies2024Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Studies indicate that individuals with current or former experiences of being a refugee are more likely to have experienced adverse events, like violence, and face mental health challenges in their host countries. After arrival in host countries, people with refugee experiences often confront various post-migration adversities like discrimination. However, research in this area has been hampered by limitations and a lack of child perspective. This thesis aims to examine both pre-, peri- and post-migration factors that impact the health, well-being, and experiences of children and adults who have migrated to Sweden as refugees.

    Article I is a systematic review of Nordic studies on resilience, risk and protective factors for health in refugee children. We found that adversity was consistently identified as a risk factor for poorer health, but otherwise, findings were inconsistent. No study explicitly examined resilience. Article II examined the relationship between refugee experiences in childhood and health in adulthood in a nationally representative sample. The study found no clear link between childhood refugee experiences and worse health in adulthood. Article III investigated differences in health and health-related behaviours between sexual and gender minority refugees, migrants, and Swedish/Western-born individuals and their heterosexual peers. We found higher rates of mental and general ill-health and worse health-related behaviours in sexualand gender-minority individuals regardless of whether they were refugees, migrants, or Swedish and Western-born. Surprisingly, our study revealed no indications of inferior health outcomes among refugee or migrant sexual and gender minorities in comparison to Swedish/Western-born individuals. Article IV investigated mental health and functioning of refugee children and young adults in Sweden. We found lower rates of mental ill-health than previously reported in other studies on refugee children and young adults. Unaccompanied refugee children had worse outcomes than those accompanied. Article V explored the experiences of refugee children and their agency in constructing their own lives during migration. We found that child refugees express a longing for a good life and demonstrate active agency despite facing diverse challenges.

    Overall, the prevalence rates for mental ill-health were lower than in many previously published studies even though the prevalence rates are higher than in many studies published on the general population of children in Sweden. Further, the results suggest that these effects are transient. The studies highlight the need to focus on the heterogeneity of the population, for example, by addressing factors that pose a risk to health and rights in refugee children and adults. Moreover, the research emphasizes the importance of adopting a perspective that simultaneously acknowledges both the strengths and vulnerabilities of refugee children. Additionally, this perspective should recognize individual differences, rights, and goals.

    List of papers
    1. A systematic review of studies on resilience and risk and protective factors for health among refugee children in Nordic countries
    Open this publication in new window or tab >>A systematic review of studies on resilience and risk and protective factors for health among refugee children in Nordic countries
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    2024 (English)In: European Child and Adolescent Psychiatry, ISSN 1018-8827, E-ISSN 1435-165X, p. 667-700Article, review/survey (Refereed) Published
    Abstract [en]

    The Nordic welfare model is often used as an example for the promotion of health and wellbeing, even in vulnerable groups of children, such as refugees. Nonetheless, there are no published reviews on resilience and/or risk and protective factors for physical and mental health among refugee children living in Nordic countries. In this systematic review, we identified 5181 studies on the topic, screened titles, and abstracts, viewed 632, and finally included 26 studies. These studies described 18 samples with a total of 34,080 individuals ranging in ages 0–18 years. Overall, the studies were of good quality. Nearly all studies assessed adversity. Six studies reported physical health outcomes and all studies mental health outcomes, most often post-traumatic stress disorder and anxiety. None explicitly studied resilience. While we found that age and sex are the most frequently studied  risk- and protective factors, findings are inconclusive, since the direction of the associations was different in the different studies. This systematic review indicates that there is still a need for well-designed and -powered studies using clear definitions of key study concepts to examine health outcomes and resilience among refugee children in Nordic countries.

    Place, publisher, year, edition, pages
    Berlin, Germany: Springer, 2024
    National Category
    Public Health, Global Health, Social Medicine and Epidemiology
    Identifiers
    urn:nbn:se:liu:diva-184444 (URN)10.1007/s00787-022-01975-y (DOI)000784912400001 ()2-s2.0-85128482498 (Scopus ID)
    Note

    Funding: Open access funding provided by Linköping University. FORTE (Dnr 2019–12-01).

    Available from: 2022-04-21 Created: 2022-04-21 Last updated: 2024-03-15Bibliographically approved
    2. Is refugee experience in childhood a risk for poorer health in adulthood?—A Swedish national survey study
    Open this publication in new window or tab >>Is refugee experience in childhood a risk for poorer health in adulthood?—A Swedish national survey study
    Show others...
    2023 (English)In: PLOS Global Public Health, E-ISSN 2767-3375, Vol. 3, no 11, p. e0002433-e0002433Article in journal (Refereed) Published
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-199835 (URN)10.1371/journal.pgph.0002433 (DOI)
    Available from: 2023-12-23 Created: 2023-12-23 Last updated: 2024-03-01
    3. Health and health-related behaviours in refugees and migrants who self-identify as sexual or gender minority – A National population-based study in Sweden
    Open this publication in new window or tab >>Health and health-related behaviours in refugees and migrants who self-identify as sexual or gender minority – A National population-based study in Sweden
    2022 (English)In: eClinicalMedicine, E-ISSN 2589-5370, Vol. 52Article in journal (Refereed) Published
    Abstract [en]

    Background To examine health and health-related behaviors in migrant and refugee individuals who identify as sexual or gender minority, and in comparison to their heterosexual peers. Methods The study included 168,952 individuals (aged 16-84 years, males: 45.9%, sexual or gender minorities: 3.1%) who answered the Swedish National Public Health Survey in 2018 and 2020. Participants were grouped into Swedish-and Western-born (White) heterosexual, White sexual- or gender minority, migrant heterosexual, migrant sexual- or gender minority, refugee heterosexual, and refugee sexual- or gender minority. Outcomes included mental health (for example suicidal ideation, wellbeing), general health, risky behaviors (risk alcohol use, risk gambling, and substance use), and experiences of violence. Associations between 1) sexual- or gender -ethnic identities and 2) gender-ethnic identities and all outcomes were analyzed using logistic and linear regression adjusting for sex, age, and educational level. Findings Being a sexual- or gender minority, regardless of ethnic minority status, was associated with worse general health and mental ill-health compared to heterosexual peers including suicidal ideation in refugee sexual- or gender minority individuals (OR 2.42, 95 % CI 1.44-4.08). Ethnic minorities (heterosexual and sexual- or gender minority migrants and refugees) had lower odds of drug and risk alcohol use compared to White heterosexual peers but higher odds of risk gambling (1.88, 1.49-2.37 for refugee heterosexuals). Transgender refugees had high odds for risk gambling (8.62, 1.94-38.40) and exposure to physical violence (7.46, 2.97-18.70). Interpretation In this national population-based study, sexual and gender minority individuals have worse mental and general health regardless of ethnic minority status. We did not find evidence for worse health in sexual- or gender minority refugees in comparison to migrant, and White sexual- or gender minorities and their heterosexual peers. Transgender individuals (White and ethnic minority) experienced significantly higher levels of physical violence. Public health policy should emphasize preventive measures to reduce exposure to violence and discrimination in sexual- and gender minority individuals, increase access and use of mental healthcare services and sensitise healthcare professionals about higher rates of health and related issues faced by sexual- and gender minority individuals including those with multiple minority identities.

    Place, publisher, year, edition, pages
    Elsevier, 2022
    Keywords
    Ethnicity; Migrant; Refugee; Sexual minority; Gender minority; LGBTQ; Transgender health; Mental health; Inequalities; Sweden
    National Category
    Public Health, Global Health, Social Medicine and Epidemiology
    Identifiers
    urn:nbn:se:liu:diva-188028 (URN)10.1016/j.eclinm.2022.101641 (DOI)000880311500001 ()36313143 (PubMedID)
    Note

    Funding: Linkoping University; Save the Children Sweden

    Available from: 2022-09-02 Created: 2022-09-02 Last updated: 2024-03-01Bibliographically approved
    4. “You cannot just stop life for just that”: a qualitative study on children’s experiences on refugee journey to Sweden
    Open this publication in new window or tab >>“You cannot just stop life for just that”: a qualitative study on children’s experiences on refugee journey to Sweden
    2024 (English)In: European Child and Adolescent Psychiatry, ISSN 1018-8827, E-ISSN 1435-165XArticle in journal (Refereed) Epub ahead of print
    Abstract [en]

    Children with refugee backgrounds are often exposed to violence and other adverse experiences with well-known detrimental consequences on mental health. However, the current group of approximately 40 million child refugees is heterogeneous, stressing the importance of first-person perspectives in understanding children's unique experiences and needs related to the migration process. Identifying contextual factors promoting health and resilience is also essential. For instance, the roles children play as active agents in constructing their own lives and adapting to different environments are poorly described in contemporary research on child refugees and their mental health. To address these knowledge gaps, we conducted qualitative interviews with a reflexive thematic analysis with eighteen children with refugee backgrounds in Sweden. This resulted in two main themes: Longing for a good life that cannot be taken for granted and Challenged agency and changing rights. The narratives indicate that children, although exposed to different challenges in different migration phases and based on gender and asylum status, have experiences of ordinary childhood with a desire for a good life with prospects. The results also show that children execute active and adaptable agency that is impacted by various factors. Reaching the full age appears to be a confusing and ambivalent transition due to changes in rights. The results pinpoint several possibilities to address factors that pose a risk to health and restrictions of rights among child refugees.

    Place, publisher, year, edition, pages
    SPRINGER, 2024
    Keywords
    Refugee; Adversity; Resilience; Agency; Human rights; Thematic analysis
    National Category
    Social Work
    Identifiers
    urn:nbn:se:liu:diva-200906 (URN)10.1007/s00787-024-02387-w (DOI)001162118900001 ()38360923 (PubMedID)
    Funder
    Linköpings universitet
    Note

    Funding: Linkoping University; Swedish Research Council for Health, Working Life and Welfare (FORTE) [Dnr 2019-12-01, Dnr 2022-01059]; Cocozza Foundation [Dnr LIU-2022-02135]

    Available from: 2024-02-17 Created: 2024-02-17 Last updated: 2024-03-01
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  • Hugoo, Olivia (Editor)
    Linköping University, Prioriteringscentrum.
    Året som gått 2023: Prioriteringscentrums verksamhetsberättelse2023Report (Other (popular science, discussion, etc.))
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  • Hjertstedt Otterström, Oliver
    Linköping University, Department of Management and Engineering, Product Realisation.
    Package Concept for High Variation Products to Improve Production: Package Development and Implementation to Improve Production of Heavy and High Variation Products2023Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Within the Master’s program in mechanical engineering at Linköping University, this thesis project unfolds in collaboration with Metso Sweden, specifically at their Sala factory. Focused on addressing challenges in packaging processes for Metso’s VASA-line slurry pumps, the project endeavors to devise a concept that not only meets global shipping requirements but also enhances factory output.

    The research unfolds with an exploration of the background, emphasizing the complexities of manufacturing large-scale pumps for heavy-duty industries. Operating in 45 countries with a workforce of approximately 16,000 employees, Metso’s site in Sala specializes in pump production, particularly for the mining industry. The unique nature of slurry pumps, designed to handle liquid solutions containing solid particles, necessitates a tailored approach to packaging.

    The identified problem lies in the high variation of pump configurations, demanding flexibility in production and packaging. Currently, custom-made packages are crafted by experienced operators, who are lacking feedback on their performance. The packaging process involves standard pallets or custom-made packages, with the latter lacking standardization and documentation, introducing uncertainties in transport.

    This study aims to improve overall efficiency at Metso by addressing bottlenecks and knowledge gaps in packaging, focusing on the VASA-line slurry pumps. The goal is to present a concept that aligns with global shipping requirements and has the potential to significantly increase factory output. The findings, supported by production analysis and a detailed implementation plan, estimating a 3.38-fold increase in current production capacity.

    The thesis utilizes production analysis methods in supporting product development and optimizing packaging processes. It further highlights the influence of global shipping requirements on production dynamics, necessitating additional steps in package assembly. With a focus on time rather than costs, this thesis positions itself as a practical guide for enhancing production efficiency within a constrained time frame.

    In summary, this thesis unfolds as an exploration of packaging challenges, offering tangible insights for product development in a production setting and package development, especially in the context of global shipping.

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  • Alexandersson, Karl-Johan
    et al.
    Linköping University, Department of Management and Engineering.
    Karlsson, Anton
    Linköping University, Department of Management and Engineering.
    Upplevelsebaserat lärande och EU: En litteraturstudie om simuleringar och ett komplext politiskt system2024Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Inom samhällskunskapen i svensk skola ställer sig EU-undervisningen till synes vid sidolinjen. De studier som har gjorts på området visar på att det är ett ämne som få elever eller lärare är särskilt entusiastiska kring. Vidare tyder forskningen på att den undervisning som bedrivs om ämnet sällan är särskilt djupgående. Istället ligger fokus på att ge en mer övergripande och elementär undervisningen om unionen, avgränsat från kunskaper om demokrati och medborgarskap. Syftet med denna litteraturstudie är att undersöka hur upplevelsebaserat lärande kan användas inom EU-undervisning. Den primära frågan uppsatsen ämnar besvara är hur simuleringars potentiella inkludering i EU-undervisning kan se ut och vilka för- och nackdelar denna form av undervisning kan associeras med. Genom analys av tidigare forskning om EU-undervisning och simuleringar har en rad slutsatser kunnat dras. Litteraturstudien visar bland annat att simuleringar kan lämpa sig i undervisningen men att det beror på vad undervisningen ska ha för lärandemål. Simuleringar har bland annat önskvärda effekter såsom ökad motivation och engagemang hos eleverna och en ökad förståelse för det politiska systemet. Simuleringar konkretiserar och förenklar även studieobjektet till en hanterbar nivå vilket tillåter eleverna att enklare hantera ett annars komplext politiskt system.

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  • Lindskog, Sofia
    Linköping University, Department of Management and Engineering, Political Science.
    Ekonomiska Intressen och Politisk Makt: En Analys av Syriens Väg mot Predatorstat2023Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This study examines the concept and implementation of the rentierstate theory, and it aims to conduct a historical background analysis of the political developments in Syria, with a specific focus on the authoritarian rule of the Al-Assad family and its role in the onset of the ongoing civil war. By examining the governance periods of Hafez al-Assad and his son Bashar al-Assad, the political, economic, and social factors shaping Syria's transition into a predatory state are analyzed. The civil war, which erupted in 2011 in the aftermath of the Arab Spring, is scrutinized with an emphasis on its complexity and root causes. The thesis also provides an overview of prior research on Syria, with an emphasis on political, economic, and conflict studies. The research and analysis methodology employed is qualitative, relying on a thorough review of a qualitative literature review.  

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  • Hedengren, Simon
    Linköping University, Department of Management and Engineering.
    Medier och medborgarskap i en digitaliserad värld: En strukturerad litteraturstudie om metoder, fördelar och utmaningar gällande undervisning i medielitteracitet2024Student paper second term, 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Den digitala världen utvecklas i rask takt, och elever i dagens skola spenderar mycket tid på mediala plattformar. Trots att styrdokument fastslår att samhällskunskapsundervisningen ska utveckla de kompetenser som elever behöver för att navigera detta har undervisningen inte följt med i utvecklingen. Denna litteraturstudie har som syfte att undersöka hur undervisning i medielitteracitet kan genomföras, varför sådan undervisning är nödvändig och vilka utmaningar som behöver adresseras för att undervisningen ska vara möjlig. Empirisk data från nio forskningsartiklar analyserades utifrån pragmatisk lärandeteori. Resultatet visade att undervisningen inte sällan bedrivs med lärarcentrerad metodik, att innehållet fokuserar på de grundläggande delarna av medielitteracitet och att lärare saknar förståelse och förmåga relaterat till detta begrepp. Uppsatsen presenterar elevcentrerade aktiviteter med inslag av produktion som förslag på hur medielitteracitet kan utvecklas genom adekvat undervisning. Detta kan gestaltas i erfarenhetsbaserat lärande med inslag av inquiry. Behovet av undervisning uttrycks av såväl lärare och elever som av politiska aktörer på nationell, europeisk och global nivå, och blir uppenbart i ljuset av elevernas mediala vanor. För att lärare ska kunna undervisa i dessa frågor krävs det att de förses med möjligheter till fort- och utbildning inom ämnesområdet. Om läraren utvecklar en god medielitterär förmåga kommer eleverna lättare kunna guidas till att använda mediala plattformar på ett ändamålsenligt sätt vad gäller både konsumtion och produktion av innehåll – en förutsättning för kritiska, ansvarstagande och demokratiska samhällsmedborgare.

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  • Suta, Hana
    Linköping University, Department of Management and Engineering.
    Hållbar utveckling i Bosnien och Hercegovinas gymnasieskolor: En uppsats om hur hållbar utveckling appliceras i Bosnien och Hercegovinas gymnasieskolor2023Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Denna uppsats tar utgångspunkt i Bosnien och Hercegovina (BiH) och undersöker hur hållbar utveckling undervisas i gymnasieskolor. Inom hållbar utveckling tillämpas även agenda 2030 och de 17 globala målen. Alltfler människor, företag och andra aktörer beaktar sin påverkan på hållbar utveckling genom att se över sin produktion och konsumtion. I skolan undervisas hållbar utveckling för att lära unga att se över sin påverkan på hållbar utveckling och eventuellt förändra ens vardagsrutiner. UNESCO har skapat ett ramverk i syfte att utbilda fler människor i hållbar utveckling. I detta ramverk beskriver UNESCO vilka kunskaper som är relevanta för undervisningen, olika undervisningsmetoder samt prioriteringsområden i undervisningen. Ramverket används i uppsatsen som utgångspunkt för vad lärare bör ha i åtanke och efterfråga i undervisningen när det gäller hållbar utveckling. En kvalitativ undersökningsmetod har tillämpats i form av intervjuer och enkäter. Enkäterna har skickats till samma deltagare som har intervjuats. Syftet med enkäterna var att få mer information om hur mycket kunskap/förståelse deltagarna har om hållbar utveckling. Intervjuerna genomfördes för att samla in mer djupgående svar. Deltagarna är gymnasielärare i olika ämnen i distriktet Sarajevo. Studien visar att i BiH undervisas ämnet hållbar utveckling bara i enstaka ämnen, men inte på en djupare nivå. Utifrån resultatet visar det sig att lärare väljer att inte fokusera på hållbar utveckling mer än att eleverna ska känna till vad det är. Ämnet finns inte heller konkret i deras läroplan eller anger att elever ska ha förståelse för hållbar utveckling.

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  • Public defence: 2024-04-05 14:00 TEMCAS, TEMA building, LinköpingOrder onlineBuy this publication >>
    Hordijk, Ruben
    Linköping University, Department of Thematic Studies, The Department of Gender Studies. Linköping University, Faculty of Arts and Sciences.
    Spectral Inheritance: Unlearning the Maturity-trope2024Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Drawing on continental and decolonial feminist philosophy, Spectral Inheritance: Unlearning the Maturity-trope addresses the centrality of the notions of “maturity” and “development” in discussions of human subjectivity, temporality and ethics. Building on Sylvia Wynter’s framework, the dissertation proposes to read the Euromodern genres of Man in developmental terms. The notion of im/maturity organizes who is capable of sovereign self-governance and who must be governed. By analogy with a normative developmental model of a racialized figure of “the Child,” immaturity-status is assigned to populations and demographics deemed incapable of self- governance. This invention of the civilizational figure of the Child is central to Developmental Man’s atomistic ontology, which is premised on hierarchy, the denial of vulnerability and the severance from a constitutive web of relationality. Such severance is embedded in histories of colonization and separation of children from their communities in Euromodernity and the transgenerational inheritances thereof. In dialogue with Sylvia Wynter, Alia Al-Saji, María Lugones, Judith Butler and others, this dissertation proposes spectral inheritance as an alternative reconfiguration of the nexus of subjectivity, ethics and temporality. Displacing chrononormative developmental tropes of maturation, spectral inheritance acknowledges the coexistence of the plural past in a structure of reinvention, reconfiguration and response to and through its haunting. It insists on unlearning the response-debilitating legacies of Developmental Man and relearning a response-enabling relation to the plural past. Employing feminist figurations, Fanonian sociogeny, genealogical theories of subjectivation, and engaging feminist theories of response-ability, this text is an exercise in such spectral inheritance, asking what it means to inherit the catastrophic worlds of Developmental Man response-ably as an ongoing work of unlearning and co-becoming through a responsive relation to the plural past. 

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  • Public defence: 2024-03-25 10:30 TEMCAS, LinköpingOrder onlineBuy this publication >>
    Kaplan, Ahmet
    Linköping University, Department of Electrical Engineering, Communication Systems. Linköping University, Faculty of Science & Engineering.
    Signal Processing Aspects of Bistatic Backscatter Communication2024Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Passive Internet-of-Things (IoT), a new paradigm based on battery-free devices, is a promising technology to enable several use cases that require connectivity with stringent requirements in terms of cost, complexity, and energy efficiency. These use cases span critical sectors, such as healthcare, transportation, and agriculture. Passive IoT relies on the development of technologies such as radio frequency (RF) energy harvesting, low-power computing, and backscatter communication. Particularly, backscatter communication allows devices to modulate its information on external RF signals that are backscattered to the receiver or reader.

    BC considers the following elements: a carrier emitter (CE), a reader, and a backscatter device (BD). The main BC configurations are monostatic BC (MoBC), ambient BC (AmBC) and bistatic BC (BiBC). In a MoBC setup, the CE and reader are co-located and share parts of the same infrastructure. A monostatic system suffers from round-trip path loss, and requires full-duplex technology if the same antennas are simultaneously used for transmission and reception. In an AmBC setup, CE and reader are in different locations, while the CE is not considered dedicated. AmBC uses ambient sources to transmit information, such as Wi-Fi, Bluetooth, and TV signals. In BiBC, the CE and reader are also spatially separated from each other, but there is a dedicated CE. In addition, BiBC can operate in half duplex mode, thus avoiding the complexity associated to the full-duplex operation.

    Due to the double path-loss effect on the two-way backscatter link, the received backscattered signal is typically weak compared to the direct link interference (DLI) from a CE. This requires a high dynamic range of the circuitry in the reader. As a result, a high-resolution analog-to-digital converter (ADC) is required to detect the weak backscattered signal under heavy DLI; this represents a great limitation because ADCs are major power consumers. Nonetheless, the benefits provided by multiple-antenna and distributed multiple-input multiple-output (MIMO) technologies can be explored to circumvent the limitations of BiBC, which is the main focus of this thesis.

    In this context, the contributions of this thesis are two-fold. First, we propose a novel transmission scheme that includes a protocol for channel estimation at the multiple-antenna CE as well as a transmit beamformer design to suppress the DLI between the two ends of a bistatic link (namely CE and reader) and increase the detection performance of the BD symbol. Further, we derive a generalized log-likelihood ratio test (GLRT) to detect the symbol/presence of the BD and provide an iterative algorithm to estimate the unknown parameters in the GLRT. Simulation results show that the required dynamic range of the system is significantly decreased while the detection performance of the BD symbol is increased, by the proposed algorithm compared to a system not using beamforming at the CE.

    For the second part, we consider BiBC in the context of cell-free MIMO networks by exploring the optimal selection of CE and reader among multiple access points, leveraging prior knowledge about the area where the BD is located. First, a maximum a posteriori probability (MAP) detector to decode the BD information bits is derived. Then, the exact probability of error for this detector is obtained. In addition, an algorithm to select the best CE-reader pair for serving the specified area is proposed. Finally, simulation results show that the error performance of the backscatter communication (BC) is improved by the proposed algorithm compared to the benchmark scenario.

    List of papers
    1. Dynamic Range Improvement in Bistatic Backscatter Communication Using Distributed MIMO
    Open this publication in new window or tab >>Dynamic Range Improvement in Bistatic Backscatter Communication Using Distributed MIMO
    2022 (English)In: 2022 IEEE GLOBAL COMMUNICATIONS CONFERENCE (GLOBECOM 2022), IEEE , 2022, p. 2486-2492Conference paper, Published paper (Refereed)
    Abstract [en]

    Backscatter communication (BSC) is a promising solution for Internet-of-Things (IoT) connections due to its lowcomplexity, low-cost, and energy-efficient solution for sensors. There are several network infrastructure setups that can be used for BSC with IoT nodes/passive devices. One of them is a bistatic setup where there is a need for high dynamic range and high-resolution analog-to-digital converters at the reader side. In this paper, we investigate a bistatic BSC setup with multiple antennas. We propose a novel algorithm to suppress direct link interference between the carrier emitter (CE) and the reader using beamforming into the nullspace of the CEreader direct link to decrease the dynamic range of the system and increase the detection performance of the backscatter device (BSD). Further, we derive a Neyman-Pearson (NP) test and an exact closed-form expression for its performance in the detection of the BSD. Finally, simulation results show that the dynamic range of the system is significantly decreased and the detection performance of the BSD is increased by the proposed algorithm compared to a system not using beamforming in the CE, which could then be used in a host of different practical fields such as agriculture, transportation, factories, hospitals, smart cities, and smart homes.

    Place, publisher, year, edition, pages
    IEEE, 2022
    Series
    IEEE Global Communications Conference, ISSN 2334-0983
    Keywords
    Bistatic backscatter communication; dynamic; range; interference suppression; internet of things (IoT); multipleinput multiple-output (MIMO)
    National Category
    Communication Systems
    Identifiers
    urn:nbn:se:liu:diva-193481 (URN)10.1109/GLOBECOM48099.2022.10000927 (DOI)000922633502086 ()9781665435406 (ISBN)9781665435413 (ISBN)
    Conference
    IEEE Global Communications Conference (GLOBECOM), Rio de Janeiro, BRAZIL, dec 04-08, 2022
    Note

    Funding Agencies|European Union [101013425]; ELLIIT; KAW foundation

    Available from: 2023-05-09 Created: 2023-05-09 Last updated: 2024-02-29
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  • Axelsson, Karin
    et al.
    Linköping University, Department of Management and Engineering, Information Systems and Digitalization. Linköping University, Faculty of Arts and Sciences.
    Melin, Ulf
    Linköping University, Department of Management and Engineering, Information Systems and Digitalization. Linköping University, Faculty of Arts and Sciences.
    Granath, Malin
    Linköping University, Department of Management and Engineering, Information Systems and Digitalization. Linköping University, Faculty of Arts and Sciences.
    Exploring services in a smart city through socio-technical design principles: Revealing five tensions in a smart living context2024In: Government Information Quarterly, ISSN 0740-624X, E-ISSN 1872-9517, Vol. 41, no 1, article id 101915Article in journal (Refereed)
    Abstract [en]

    Smart cities have been studied for many years, but smart homes and the citizens' actual living in these smart homes are less researched. We argue that for digital government research, and for governments to be successful in smart city development in practice, it is necessary not only to understand living on a societal level, but also living aspects in the narrow context of homes. Citizens populate the smart city and are the ones who are supposed to use the services provided by the government. In this article we explore and analyze digital and analogue services in smart homes developed in a new city district. We have conducted observational studies in 53 apartments during an urban living expo which we analyze by applying a set of socio-technical design principles. The research question that guides the analysis is: “What tensions between values in digital and analogue services for a smart living can be revealed by a socio-technical perspective?”. We identify five tensions between: 1) being in control and being controlled, 2) intended and undesirable use of personal data, 3) digital and analogue smartness, 4) smart home visions and practices, and 5) environmental and social sustainability. By revealing these tensions, we contribute to an understanding of the complexity of smart living. We also contribute by highlighting the importance of applying a perspective that captures both technology and citizen and user issues (i.e., social aspects) when developing services in the smart home context.

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  • Nzulu, Gabriel Kofi
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    Högberg, Hans
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    Eklund, Per
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    Hultman, Lars
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    Nude, Prosper M.
    University of Ghana, Accra, Ghana.
    Yaya, Abu
    University of Ghana, Accra, Ghana.
    Magnuson, Martin
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    Chemical Reactivity and Alteration of Pyrite Mineral in the Kubi Gold Concession in Ghana2024In: Mining, Metallurgy & Exploration, ISSN 2524-3462Article in journal (Refereed)
    Abstract [en]

    Pyrite is the most common among the group of sulfide minerals in the Earth and abundant in most geological settings. This gangue mineral in association with garnet, hematite, magnetite, and other sulfide minerals acts as an indicator mineral in the Kubi concession of the Asante Gold corporation in Ghana. X-ray diffraction (XRD), air annealing in a furnace, energy-dispersive x-ray spectroscopy (EDX), and X-ray photoelectron spectroscopy (XPS) were applied to investigate the crystal structure, identify individual elements, permanence, transformation, and chemical/electronic properties of such pyrite. The study aims to identify individual elements and to gain an understanding of the surface reaction mechanisms, as well as the properties of precipitated pyrite particles observed during the hydrothermal formation of the ore deposit. XRD shows that pristine and annealed samples contain some hematite and quartz besides pyrite. Results from air annealing indicate that the relationship between pyrite and hematite-magnetite is controlled by temperature. EDX reveals that the sample has O and C as contaminants, while XPS in addition reveals Ba, Au, P, Al, and N. These elements are attributed to pyrite that bonds metallically or covalently to neighboring ligands/impurity minerals such as oxides, chalcogenide sulfides, as well as the gangue alteration minerals of magnetite and hematite in the pyrite sample.

    These findings suggest that during the hydrothermal flow regime, pyrite, pathfinder elements, and impurity minerals/metals were in contact with quartz minerals before undergoing hematite transformation, which thus becomes an indicator mineral in the Kubi gold concession.

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  • Metson, Genevieve
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Ecological and Environmental Modeling. Linköping University, Faculty of Science & Engineering. Department of Geography and Environment, Western University, London, Ontario, Canada. .
    Tonderski, Karin
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, Faculty of Science & Engineering.
    Carlsson, Elizabeth
    Flöden i stadsodlingar: ett konstnärligt och vetenskapligt utforskande av hur näringsämnen rör sig i Linköpings trädgårdar2024Report (Other academic)
    Abstract [sv]

    Denna broschyr har tagits fram i anslutning till en utställning där en forskargrupp samverkar med en konstnär. Den utforskar hur stadsodling kan bidra till hållbara resursflöden och därigenom stödja produktion av livsmedel, rekreation och god vattenkvalitet.

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  • Metson, Genevieve
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Ecological and Environmental Modeling. Linköping University, Faculty of Science & Engineering. Department of Geography and Environment, Western University, London, Ontario, Canada .
    Tonderski, Karin
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, Faculty of Science & Engineering.
    Carlsson, Elizabeth
    Flowing through urban agriculture: Art-science explorations of nutrient movement through Linköping's gardens2024Report (Other academic)
    Abstract [en]

    This document accompanies an art & science collaborative exhibit exploring how urban agriculture can contribute to sustainable resource flows to support food production, recreation, and water quality.

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  • Larsson, Isac
    et al.
    Linköping University, Department of Management and Engineering.
    Henriksson, Jacob
    Linköping University, Department of Management and Engineering.
    Identitet och Säkerhet: Drivkrafterna bakom Rysslands invasion av Ukraina 20222024Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The objective of this study is to examine the explanatory capabilities of the international theories, constructivism and structural realism, both separately and complementary. The explanatory capabilities of the theories are examined in the context of explaining the driving forces of Russia's invasion of Ukraine February 24, 2022. This study employs a qualitative research design and a theory-testing method to examine the theories capabilities. This is accomplished by analyzing compiled empirical material from numerous sources. Constructivism posits that the international system is socially constructed and underscores the importance of social norms, shared perceptions and identity in shaping political behavior. Structural realism however, diverges from this perspective and instead highlights the importance of security and power in an anarchic international system. The study concludes that structural realism and constructivism complement each other in their explanatory powers of understanding the driving forces of Russia's invasion of Ukraine. Structural realism is however by far the strongest of the theories in independently explaining the driving forces of the invasion. 

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  • Moa, Jonsson
    et al.
    Linköping University, Department of Health, Medicine and Caring Sciences, Division of Nursing Sciences and Reproductive Health.
    Emma, Gustafsson
    Linköping University, Department of Health, Medicine and Caring Sciences, Division of Nursing Sciences and Reproductive Health.
    Att vårda under en pandemi: - En litteraturstudie om sjuksköterskors upplevelse av att vårda patienter med Covid-192023Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Bakgrund: Covid-19 var en pandemi som orsakades av coronaviruset SARS-CoV-2 som sedan i slutet av 2019 spridit sig snabbt över stora delar av världen. Studier från utbrott av tidigare coronavirus har visat att sjuksköterskors upplevelse av att vårda patienter med liknande infektionssjukdomar har varit utmanande. Att beskriva sjuksköterskors erfarenheter av att vårda patienter under Covid-19-pandemin kan användas till eventuella framtida infektionsutbrott. 

    Syfte: Syftet med studien var att undersöka sjuksköterskors upplevelse av att vårda patienter med misstänkt eller bekräftad Covid-19 inom slutenvården. 

    Metod: En allmän litteraturstudie med systematisk ansats som är baserad på elva kvalitativa artiklar. Datainsamlingen gjordes i databaserna CINAHL och PubMed. 

    Resultat: Analysen resulterade i två huvudteman och åtta subteman. Huvudtemat fysiska och psykiska utmaningar inkluderar subtemana utmanande arbetsmiljö, rädsla för smittspridning, utmaningar gällande personlig skyddsutrustning, brist på kunskap och kompetens samt utmaningar vid omvårdnad. Huvudtemat upplevelser av ledning och medarbetare inkluderar subtemana ledning och organisationens roll, sjuksköterskornas behov av stöd samt teamarbete. 

    Slutsats: Studien visade att sjuksköterskor som arbetar i en pandemi behöver få tillgång till stöd av både kollegor och ledning samt få tydliga riktlinjer och utbildning för att kunna erbjuda en god och säker vård. 

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  • Wittwång, Arvid
    et al.
    Linköping University, Department of Management and Engineering, Product Realisation.
    Storck, Markus
    Linköping University, Department of Management and Engineering, Product Realisation.
    Användarcentrerad konceptutveckling: Förbättrad användarupplevelse genom välgrundade designändringar i Husqvarnas batteridrivna motorsågar2023Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    With Husqvarna as the case company, this master’s thesis explores the desired features of a battery-powered chainsaw and how they can be achieved. This research is done in light of Husqvarna’s implementation of a centrifugal clutch in the battery-powered model 542i XP – at launch during the autumn of 2023, the first of its kind. The research is carried out through qualitative methods, with data from interviews held at multiple of Husqvarna’s departments as a central part. This data is extended through interviews with resellers and professional users, to map the terrain of the appreciated and problematic characteristics of battery-powered chainsaws. As a brand-new product, the aforementioned Husqvarna 542i XP is not available in stores at the time of writing this report. Therefore, experience-focused research is emphasized in-house at Husqvarna, with employees familiar with the product from the development phase. Complementary data is collected through practical testing by the authors of this report, and tests of prototypes, in collaboration with professionals.

    The collected empirical data is categorized and grouped, combine with theory and technical data, and distilled to a design criteria list. A function/means tree is created on this foundation, and used alongside the methods to generate concepts to meet the requests and demands. Concepts are created on an overarching level, with more weight put on concepts focused on details, evaluated through weighted and comparative methods. Three final concepts are chosen for further refinement.

    The concept FrivarvD with its idea of delayed inertia to enhance the starting behaviour is considered unjustifiably complex. However, the concepts Tomgång and Propeller show great potential. The former is proposed as an added, optional mode, excelling through rapid response to the throttle and continuous cooling. The latter is a compliant mechanism version of a centrifugal clutch. The duo also addresses the desired and well-known start and stop behaviours. A transition from a sensor-less electric motor to a more exact and sensor-controlled version is suggested as an enhancement to the two concepts.

    This master’s thesis results in a summary of the distinguished problems and insights of preferable properties of using a battery-powered chainsaw. Further, the tried-and-true centrifugal clutch has an important role in preventing sudden stops, but is evidently only one of many solutions to address the identified criteria. However, it is reliable and highly realistic. Finally, the authors of this report recommend Husqvarna to upgrade the motor, and realize the concept Tomgång to achieve an improved user-experience for batterypowered chainsaws

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    Användarcentrerad konceptutveckling – Förbättrad användarupplevelse genom välgrundade designändringar i Husqvarnas batteridrivna motorsågar
  • Carlborg, Sara
    et al.
    Linköping University, Department of Health, Medicine and Caring Sciences.
    Wiberg, Marcus
    Linköping University, Department of Health, Medicine and Caring Sciences.
    Anhörigas upplevelser av plötslig hjärtdöd: De emotionella och praktiska konsekvenserna av plötslig död inom familjen2023Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Introduction: Unexpected death such as sudden cardiac death, leaves no time forfamilies to prepare and provides different challenges than in the case of expected death. To better understand the needs of families, healthcare workers must have knowledge about the bereavement experience of families following sudden cardiac death.

    Aim: To describe families experience of losing a family member by sudden cardiac death.

    Method: A qualitative approach was applied in this literature review. A database search was conducted in PubMed, CINAHL and PsycINFO and nine original articles were selected for content analysis.

    Result: Three main themes were identified: The sudden death, Fear of another death, and To live with loss. The result highlights the first reactions to the death, the fear of potentially losing another person to sudden death, and how the families dealt with the loss and found ways to move forwards.

    Conclusion: Healthcare workers have an important role in informing families about the cause of death to facilitate the bereavement process. It is important for health care workers to be empathic and available, to improve the family’s experiences. Peer support may help with families need for psychosocial support.

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  • Thorén, Tobias
    Linköping University, Department of Physics, Chemistry and Biology, Bioinformatics.
    Prediction of multiple conformational states of membrane proteins2024Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Predicting protein structures has long been an area of active research in the field ofbioinformatics. Great strides have recently been made in this area by googles DeepMindteam. They developed an AI called AlphaFold which is able to make the most accuratepredictions of protein structures as of date. With the advent of AlphaFold some considerthe problem solved. There is however an area in protein prediction that has lagged be-hind, that of multi conformational prediction. There are proteins that can take on oneout of several active forms in the body. Making predictions for these are harder than forsingle conformational proteins due to an increase in complexity and a lack of data. Apromising solution to this problem is to introduce noise to the input data AlphaFold usesto create a wider range of predictions. In this thesis multi conformational prediction withdifferent methods to introduce noise is evaluated. Dropout, disclosing templates, untar-geted Multiple sequence alignment(MSA) subsampling and targeted MSA subsamplingwere used. It was concluded introducing noise did indeed improve the prediction of mul-tiple conformations. Among them, MSA subsampling seemed to be the most effective,especially untargeted MSA subsampling. Dropout also seemed to slightly improve theresults while excluding template information did little to nothing. AlphaFold was unableto predict both structures for 6 out of 16 structures, even with introduced noise. No clearreason for why this could be determined, but the leading hypothesis is that AlhpaFoldwas unable to extract sufficient information about both conformations from the MSAdata for these proteins.

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  • Saber, Simon
    Linköping University, Department of Electrical Engineering.
    Battery Degradation and Health Monitoring in Lithium-Ion Batteries: An Evaluation of Parameterization and Sensor Fusion Strategies2024Independent thesis Advanced level (degree of Master (Two Years)), 28 HE creditsStudent thesis
    Abstract [en]

    The purpose of this project was to perform model-based diagnosis on Li-ion batteries using real-world data and sensor fusion algorithms. The data used in this project was collected and distributed by NASA and mainly consists of voltage and current measurements collected on numerous batteries that were repeatedly charged and discharged from their beginning of life, and until surpassing their end of life. The health of the batteries was decided by estimating their state of health through the increase in internal resistance. To validate the results, the increase in resistance was later compared with the decrease in charge capacity. Firstly an attempt was made to parameterize equivalent circuit models by fitting the model parameters to the data with a forgetting-factor recursive least squares filter, and a batch-wise recursive least squares filter. The forgetting-factor recursive least squares filter proved unreliable and unable to consistently be able to parameterize the models. The batch-wise recursive least squares filter was able to consistently parameterize the models providing a root mean squared error of around 0.35V in simulated voltage response tests. In total 20 equivalent circuit models were parameterized for four batteries. The models were then used in conjunction with a standard Kalman filter and an unscented Kalman filter to fur-ther estimate the increase in internal resistance of the batteries throughout their lifetime. In addition, the state of charge of the batteries was tracked through Coulomb counting and later attempted to refine via the Kalman filters. The results were partly successful as both the standard and unscented Kalman filters were able to track the state of health of the batteries, albeit to a varying degree. However, the Kalman filters were unable to improve the state of charge estimation, thus highlighting a limitation in their application. While the Kalman filters showcased limitations in tracking the state of charge, their effectiveness intracking the state of health thus proved that model-based approaches and sensorfusion algorithms can be utilized with both the standard Kalman filter and the unscented Kalman filter for meaningful health tracking.

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  • Papadakou, Despoina
    Linköping University, Department of Thematic Studies.
    "How you make friends in Finland": An intersectional analysis of friendship formation in adulthood2023Independent thesis Advanced level (degree of Master (Two Years)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The present thesis explores how people’s gender with its various intersections shape theirexperiences of making friends in adulthood in the Finnish context and presents anintersectional analysis of the processes and challenges of making friends. The intersections Ifocused on were those of gender with ethnicity, race, religion and migrant or non-migrantstatus. Additionally, it discusses how the decolonial concepts of “world”-travelling anddiatopical hermeneutics can be used to explore how making friends could become easier. Thedata was collected through two focus group discussions with participants I recruited at anevent which provides a space for people of various backgrounds to meet people and makefriends. The research shows that making friends requires conscious effort and the challengesfor people who inhabit certain intersections can be bigger than for others. There are manybarriers that need to disappear for friendship formation to become easier, and that can happenby challenging our own prejudice and having an open mind. Making friends requires us to beable to travel to others’ “worlds” and welcome them to our own, which can only becomepossible if we encounter people that are different to us without prejudice. Meeting andlistening to each other is key to making friends, while also education from a young age maybe the key to combat and most importantly prevent discrimination and promote positiverelationships between people of different backgrounds.

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  • Lundvik, Axel
    Linköping University, Department of Management and Engineering, Product Realisation.
    Effektivisering av produktframtagningen för kundanpassade hydraulcylindrar genom användning av automationsramverk2023Independent thesis Advanced level (degree of Master (Two Years)), 28 HE creditsStudent thesis
    Abstract [en]

    The thesis detailed in this report was carried out on behalf of the company Xperdi AB, designautomation experts whose goal for the project was to demonstrate the effectiveness of designautomation. The project proposal includes development and use of an automation framework for automatic generation of unique hydraulic cylinder models based on specific design requirements. To execute the work, various tools and methods were combined. The model's subcomponents were constructed in the CAD program SolidWorks and supplemented with the necessary data to prepare the CAD files for configuration. XCC (Xperdi CAD Configurator) is a configuration tool that manages data from CAD and offers external control and configuration of the CAD model. To automate the configuration enabled by XCC, an interface for design choices and various executive operations was created in the Visual Studio program, with accompanying code written in the object-oriented language Visual Basic. The code in Visual Studio communicates with XCC and contains configurative instructions for the model based on selected inputs, as well as directly with SolidWorks to perform specific SolidWorks functions. The project has resulted in an adaptive hydraulic cylinder model whose specifications are controlled from the interface, with functionality for automatic generation of hole patterns and drawings for all unique configurations in the design space. The time savings of design automation have also been examined. The results indicate that the work of establishing an automation framework has significant benefits, both in terms of the speed of design changes measured and the added value that comes from reducing repetitive work. However, it should be noted that the benefits of design automation should be weighed against the resource investments required.

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  • Vernqvist, Johanna
    Linköping University, Department of Culture and Society, Division of Communication, Literature and Swedish. Linköping University, Faculty of Arts and Sciences.
    Subversive Bodies and the Sense of the Senses: Lavinia Fontana, Tullia d’Aragona and Gaspara Stampa2024In: Body, Gender, Senses: Subversive Expressions in Early Modern Art and Literature / [ed] Carin Franzén, Johanna Vernqvist, Boston: Walter de Gruyter, 2024, 1, p. 31-55Chapter in book (Refereed)
    Abstract [en]

    This chapter explores Epicurean traces in the works of early modern artists, writ-ers and poets Tullia d’Aragona (c. 1501–1556), Gaspara Stampa (c. 1523–1554) andLavinia Fontana (1552–1614). Reintroduced mainly through Poggio Bracciolini’sdiscovery of Lucretius’De rerum natura(On the Nature of Things), Epicureanismstands in contrast to early modern hegemonic ideas striving to separate body andmind. In this chapter, I argue that the writings and paintings of Fontana, d’Ara-gona and Stampa embody views on how“knowledge cannot be separated fromthe bodily world of feeling and sensation”(Ahmed 2004, 171), and that their suc-cessful representations of the (female) body and the senses show awareness ofthe“bodily habits and feelings that express [. . .] domination, so that they, alongwith oppressive social conditions that generate them, can be overcome”(Shuster-man 2006, 6). Thus, in line with Sara Ahmed’s assessment of the relation betweenknowledge and sensations, and Richard Shusterman’s theory of the essentialunion of body-mind summed up as the concept of“somaesthetic,”the analysis ex-plores how early modern literary and artistic expressions of philosophical ideaswere challenged through subversive expressions in women’s art.

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  • Franzén, Carin
    et al.
    Stockholms universitet, Sweden.
    Vernqvist, Johanna
    Linköping University, Department of Culture and Society, Division of Communication, Literature and Swedish. Linköping University, Faculty of Arts and Sciences.
    Introduction2024In: Body, Gender, Senses: Subversive Expressions in Early Modern Art and Literature / [ed] Carin Franzén, Johanna Vernqvist, Boston: Walter de Gruyter, 2024, 1, p. 1-9Chapter in book (Refereed)
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  • Franzén, Carin
    et al.
    Stockholms universitet, Sweden.
    Vernqvist, JohannaLinköping University, Department of Culture and Society, Division of Communication, Literature and Swedish. Linköping University, Faculty of Arts and Sciences.
    Body, Gender, Senses: Subversive Expressions in Early Modern Art and Literature2024Collection (editor) (Refereed)
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  • Public defence: 2024-03-22 09:00 Berzeliussalen, building 463, LinköpingOrder onlineBuy this publication >>
    Karlsson, Jerker
    Linköping University, Department of Health, Medicine and Caring Sciences, Division of Diagnostics and Specialist Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart Center, Department of Clinical Physiology in Linköping.
    Abdominal Aortic Wall Mechanics - Stress, Strain and Stiffness in A Medical Perspective: An Experimental Study in Man2024Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Background:  

    The stiffness of the abdominal aorta is considered a significant factor affecting the morbidity and mortality of cardiovascular disease. Estimating vascular stiffness is an integral part in cardiovascular risk assessment. Wall stress of the abdominal aorta appears to be a crucial factor in the remodeling of the arterial wall and the growth of aneurysms. Consequently, arterial mechanics plays a vital role in the function of the cardiovascular system. Therefore, there is a need for comprehensive studies of mechanical forces in the vessel wall to better understand the mechanisms behind normal and pathological changes that are significant for hypertension, atherosclerosis, and the development of arterial aneurysms. The aim of this study was to explore the blood pressure-induced forces in the aortic wall using a computational mechanical model, with particular attention to the effects of age, sex, and blood pressure on the remodeling process of the vessel wall.  

    Methods:  

    A computational model, comprising a solid mechanical model and a parameter identification process known as the Parameter Identification Method for Mechanical Parameters (PIMMP), was used to investigate the mechanical properties of the abdominal aortic vessel wall. Data for the model were obtained from the human abdominal aorta of volunteers: 30 healthy individuals, females (n=15) and males, divided into three age groups with an equal number of females and males (n=5 in each age group). Invasive blood pressure, measured via catheter, and diameter variation in the abdominal aorta, measured via ultrasound, were acquired to be used as input data for PIMMP. This dataset was utilized in Papers I, III, and IV. In Paper II, 24 datasets were generated, based on model parameters presented in the scientific literature.   

    Results:  

    Paper I reveals that elderly males exhibit both higher aortic wall stress and higher isotropic stress component, than females. With age, males show an increase in isotropic load-bearing fraction and a decrease in anisotropic load-bearing fraction, a trend not observed in females.  

    Paper II validates an in silico aortic model against a computerized membrane model of an abdominal aorta. The membrane model accurately predicts stress states as well as the load-bearing fraction of anisotropic material across all blood pressure levels, independent of the transmural stress gradient. However, the model’s accuracy is limited due to insufficient in vivo axial loading information.  

    Paper III demonstrates that changes in circumferential stretch have a more pronounced effect on longitudinal stress than the other way around. Both circumferential and longitudinal stiffnesses increase with age, irrespective of sex. However, sex-based differences in stiffness are observed when comparing younger and older groups.  

    Paper IV investigates pulse wave velocity (PWV) calculations using the Moens-Korteweg equation and the Bramwell-Hill equation. PWV shows a positive association with both isotropic and anisotropic material properties, with a transition zone observed between diastolic and systolic blood pressures, to a positive association with anisotropic properties at systolic blood pressure. Furthermore, an increase in PWV with age, with no significant difference between sexes, is observed.  

    The Extra Material suggests a deficiency in age-related wall stress regulation in males, potentially due to insufficient stiffness of anisotropic materials such as collagen. In contrast, females show an age-related increase in abdominal aortic wall thickness and anisotropic material stiffness, indicating adequate wall stress regulation.  

    Conclusions:  

    This doctoral dissertation focused on the effects of age and sex on the abdominal aortic wall. Overall, the findings suggest potential alterations in the collagen and elastin content during the remodeling of the abdominal aorta, which may differ between sexes. These alterations could be induced chemically or mechanically. The model has shown potential in identifying healthy individuals within a population. These insights may contribute to the understanding of cardiovascular health and disease progression. 

    List of papers
    1. An in vivo study of isotropic and anisotropic wall stress in a hyperelastic holzapfel-gasser-ogden model in the human abdominal aorta: Effects of age and sex
    Open this publication in new window or tab >>An in vivo study of isotropic and anisotropic wall stress in a hyperelastic holzapfel-gasser-ogden model in the human abdominal aorta: Effects of age and sex
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    2023 (English)In: Frontiers in Physiology, E-ISSN 1664-042X, Vol. 14, article id 1128131Article in journal (Refereed) Published
    Abstract [en]

    Background: Wall stress of the abdominal aorta (AA) appears to be an important factor in the assessment of risk for rupture based on the relationship between blood pressure and aortic diameter. We therefore investigated peak wall stress as well as isotropic and anisotropic wall stress of AA.Methods: Thirty healthy adults (male = 15) were included. Pulsatile diameter changes were determined non-invasively by an echo-tracking system, and intra-aortic pressure was measured simultaneously. A computer based mechanical model was used to compute the isotropic and anisotropic components of circumferential and longitudinal stresses.Results: Elderly males had higher total wall stress and a higher isotropic stress component in the circumferential direction and higher total longitudinal wall stress than elderly females. The isotropic component increased with age in males but not in females, whereas the anisotropic component decreased with age in both sexes.Conclusion: We found that isotropic and anisotropic properties of the abdominal aortic wall differ between young and elderly participants and between the sexes. A possible explanation could relate to chemical alterations (e.g., due to sex hormones) and changes over time in the physical distribution of fibers. Modeling of wall stress components of the human AA may contribute to a better understanding of elastin-collagen interactions during remodeling of the aortic wall.

    Place, publisher, year, edition, pages
    FRONTIERS MEDIA SA, 2023
    Keywords
    abdominal aorta, remodeling, wall stress, sex, age
    National Category
    Clinical Medicine
    Identifiers
    urn:nbn:se:liu:diva-192572 (URN)10.3389/fphys.2023.1128131 (DOI)000958802000001 ()
    Note

    Funding: Region OEstergoetland [ROE-965959]; Medical Faculty Linkoeping University; Swedish Research Council [12,661]; Swedish Heart-Lung Foundation

    Available from: 2023-03-22 Created: 2023-03-22 Last updated: 2024-02-23
    2. Abdominal Aortic Wall Cross-coupled Stiffness Could Potentially Contribute to Aortic Length Remodeling
    Open this publication in new window or tab >>Abdominal Aortic Wall Cross-coupled Stiffness Could Potentially Contribute to Aortic Length Remodeling
    Show others...
    2022 (English)In: Artery Research, ISSN 1872-9312, Vol. 28, p. 113-127Article in journal (Refereed) Published
    Abstract [en]

    Background: Wall stiffness of the abdominal aorta is an important factor in the cardiovascular risk assessment. We investigated abdominal aortic wall stiffness divided in direct and cross‑coupled stiffness components with respect to sex and age.Methods: Thirty healthy adult males (n = 15) and females were recruited and divided into three age groups: young, middle aged and elderly. Pulsatile diameter changes were determined noninvasively by an echo‑tracking system, and intra‑aortic pressure was measured simultaneously. A mechanical model was used to compute stress and stiffness in circumferential and longitudinal directions.Results: Circumferential stretch had a higher impact on longitudinal wall stress than longitudinal stretch had on circumferential wall stress. Furthermore, there were an age‑related and sex‑independent increase in circumferential and longitudinal direct and cross‑coupled stiffnesses and a decrease in circumferential and longitudinal stretch of the abdominal aortic wall. For the young group, females had a stiffer wall compared to males, while the male aortic wall grew stiffer with age at a higher rate, reaching a similar level to that of the females in the elderly group.Conclusion: Temporal changes in aortic stiffness suggest an age‑related change in wall constituents that is expressed in terms of circumferential remodeling impacting longitudinal stress. These mechanisms may be active in the development of aortic tortuosity. We observed an age‑dependent increase in circumferential and longitudinal stiffnesses as well as decrease in stretch. A possible mechanism related to the observed changes could act via chemi‑cal alterations of wall constituents and changes in the physical distribution of fibers. Furthermore, modeling of force distribution in the wall of the human abdominal aorta may contribute to a better understanding of elastin–collagen interactions during remodeling of the aortic wall.

    Place, publisher, year, edition, pages
    BioMed Central (BMC), 2022
    Keywords
    Abdominal aorta, cardiovascular disease, wall stress, cross-coupled stiffness, sex, age, remodeling
    National Category
    Clinical Medicine
    Identifiers
    urn:nbn:se:liu:diva-190181 (URN)10.1007/s44200-022-00022-0 (DOI)000888711800001 ()
    Funder
    Swedish Research Council, 12661Swedish Heart Lung FoundationLinköpings universitetSwedish Research Council, 12661
    Note

    Funding: Linkoping University; Region Ostergotland; Medical Faculty Linkoping University; Swedish Research Council [12661]; Swedish Heart-Lung Foundation

    Available from: 2022-11-28 Created: 2022-11-28 Last updated: 2024-02-23Bibliographically approved
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  • Kopsida, Maria
    et al.
    Linköping University, Department of Biomedical and Clinical Sciences, Division of Surgery, Orthopedics and Oncology. Linköping University, Faculty of Medicine and Health Sciences.
    Liu, Na
    Second Affiliated Hospital of Xi’an Jiaotong University, Xi’an, China.
    Kotti, Angeliki
    Linköping University, Department of Biomedical and Clinical Sciences, Division of Surgery, Orthopedics and Oncology. Linköping University, Faculty of Medicine and Health Sciences.
    Wang, Jing
    Linköping University, Department of Biomedical and Clinical Sciences, Division of Cell Biology. Linköping University, Faculty of Medicine and Health Sciences.
    Jensen, Lasse D
    Linköping University, Department of Health, Medicine and Caring Sciences, Division of Diagnostics and Specialist Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Diagnostics, Department of Clinical Pharmacology.
    Jothimani, Ganesan
    Chettinad Academy of Research and Education, Kelambakkam, Tamil Nadu, India.
    Hildesjö, Camilla
    Linköping University, Faculty of Medicine and Health Sciences. Linköping University, Department of Biomedical and Clinical Sciences, Division of Surgery, Orthopedics and Oncology. Region Östergötland, Regionledningskontoret, Regional Cancer Center.
    Haapaniemi, Staffan
    Region Östergötland, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Surgery in Norrköping. Linköping University, Faculty of Medicine and Health Sciences. Linköping University, Department of Biomedical and Clinical Sciences, Division of Surgery, Orthopedics and Oncology.
    Zhong, Wen
    Linköping University, Department of Biomedical and Clinical Sciences, Division of Cell Biology. Linköping University, Faculty of Medicine and Health Sciences.
    Pathak, Surajit
    Linköping University, Faculty of Medicine and Health Sciences. Linköping University, Department of Biomedical and Clinical Sciences, Division of Surgery, Orthopedics and Oncology. Chettinad Academy of Research and Education, Kelambakkam, Tamil Nadu, India .
    Sun, Xiao-Feng
    Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Oncology. Linköping University, Department of Biomedical and Clinical Sciences, Division of Surgery, Orthopedics and Oncology.
    RhoB expression associated with chemotherapy response and prognosis in colorectal cancer2024In: Cancer Cell International, E-ISSN 1475-2867, Vol. 24, no 1, article id 75Article in journal (Refereed)
    Abstract [en]

    Purpose: To examine the role of RhoB expression in relation to chemotherapy response, clinical outcomes and associated signaling pathways in colorectal cancer patients.

    Materials and methods: The study included 5 colon cancer cell lines, zebrafish embryos and 260 colorectal cancer patients treated with 5-fluorouracil (5-FU) and oxaliplatin (OXL). The methods consisted of CRISPR/Cas9, reactive oxygen species (ROS), caspase-3 activity, autophagy flux, in-silico RNA sequencing and immunohistochemistry. Gene expression analysis and pathway analysis were conducted using RNA-seq data.

    Results: All cancer lines tested, including SW480, SW480-KO13 (RhoB knockout), SW480-KO55 (RhoB knockout), HCT116 and HCT116-OE (RhoB overexpressed), exhibited cytotoxicity to 5-FU and OXL. RhoB knockout cell lines demonstrated significantly reduced migration compared to the control cell lines. Furthermore, RhoB played a role in caspase-3-dependent apoptosis, regulation of ROS production and autophagic flux. The mRNA sequencing data indicated lower expression levels of oncogenes in RhoB knockout cell lines. The zebrafish model bearing SW480-KO showed a light trend toward tumor regression. RhoB expression by immunohistochemistry in patients was increased from normal mucosa to tumor samples. In patients who received chemotherapy, high RhoB expression was related to worse survival compared to low RhoB expression. Furthermore, the molecular docking analysis revealed that OXL had a higher binding affinity for RhoB than 5-FU, with a binding affinity of -7.8 kcal/mol and HADDOCK predicted molecular interactions between RhoB and caspase 3 protein. Gene-set enrichment analysis supported these findings, showing that enrichment of DNA damage response pathway and p53 signaling in RhoB overexpression treatment group, while the RhoB knockout treatment group exhibited enrichment in the negative regulation pathway of cell migration.

    Conclusion: RhoB was negatively associated with chemotherapy response and survival in colorectal cancers. Therefore, RhoB inhibition may enhance chemotherapeutic responses and patient survival.

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  • Hansson, Eli
    et al.
    Linköping University, Department of Health, Medicine and Caring Sciences. Linköping University, Faculty of Medicine and Health Sciences.
    Isacsson, Astrid
    Linköping University, Department of Health, Medicine and Caring Sciences. Linköping University, Faculty of Medicine and Health Sciences.
    Föräldrars upplevelse av aktiviteter i vardagen när barnet med funktionsnedsättning flyttat hemifrån: - En kvalitativ intervjustudie2023Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Att få ett barn med funktionsnedsättning kan påverka livet på många olika sätt eller inte alls. Föräldrarnas liv påverkas olika mycket och på olika sätt av ett intensivt föräldraskap. Något som både kan påverka och begränsa föräldrarnas möjlighet till delaktighet i aktiviteter i vardagen. Syftet var att undersöka hur föräldrar till barn med funktionsnedsättning upplever delaktighet i aktiviteter i vardagen och sin föräldraroll när barnet har flyttat hemifrån. Metoden som används var en kvalitativ semistrukturerad intervjustudie samt analys utifrån Kristenssons (2014) sex steg. I Resultatet framkom två huvudkategorier och fyra underkategorier som belyser aspekter av föräldrarnas upplevelse av delaktighet i aktiviteter i vardagen och föräldraroll efter att barnet flyttat hemifrån; Aktiviteter i vardagen samt Föräldrarollen. Underkategorier: Möjlighet till att prioritera aktiviteter, Möta barnet i aktiviteter i vardagen, Förespråka barnets rättigheter samt Oro inför framtiden. Konklusionen är att den här studien kan bidra med en utökad förståelse för hur föräldrarna upplever delaktighet i aktiviteter i vardagen och föräldrarollen efter att barnet flyttat hemifrån. Fortsatt forskning inom området tas upp.

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    Föräldrars upplevelse av aktiviteter i vardagen när barnet med funktionsnedsättning flyttat hemifrån - En kvalitativ intervjustudie
  • Andersson, Simon
    Linköping University, Department of Electrical Engineering, Vehicular Systems.
    Modeling and Control of Fuel Cell Stacks in Autonomous Underwater Vehicles2024Independent thesis Advanced level (degree of Master (Two Years)), 28 HE creditsStudent thesis
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  • Public defence: 2024-03-26 13:15 BL32 (Nobel), B-building, LinköpingOrder onlineBuy this publication >>
    Chepkorir, Jennifer
    Linköping University, Department of Mathematics, Analysis and Mathematics Education. Linköping University, Faculty of Science & Engineering.
    Regularization methods for solving Cauchy problems for elliptic and degenerate elliptic equations2024Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    In this thesis, we study Cauchy problems for the elliptic and degenerate elliptic equations. These problems are ill-posed. We split the boundary of the domain into two parts. On one of them, say Γ0, we have available Cauchy data and on remaining part Γ1 we introduce unknown Robin data. To construct the operator equation which replaces our Cauchy problem we use two boundary value problems (BVP). The first one is the mixed BVP with Robin condition on Γ1 and with Dirichlet condition on Γ0 and the second BVP with Dirichlet Data on Γ1 and with Robin data on Γ0. The well–posedness of these problems is achieved by an appropriate choice of parameters in Robin boundary conditions. The first Dirichlet–Robin BVP is used to construct the operator equation replacing the Cauchy problem and the second Robin–Dirichlet problem for adjoint operator. Using these problems we can apply various regularization methods for stable reconstruction of the solution. In Paper I, the Cauchy problem for the elliptic equation with variable coefficients, which includes Helmholtz type equations, is analyzed. A proof showing that the Dirichlet–Robin alternating algorithm is convergent is given, provided that the parameters in the Robin conditions are chosen appropriately. Numerical experiments that shows the behaviour of the algorithm are given. In particular, we show how the speed of convergence depends on the choice of Robin parameters. 

    In Paper II, the Cauchy problem for the Helmholtz equation, for moderate wave numbers k2, is considered. The Cauchy problem is reformulated as an operator equation and iterative method based on Krylov subspaces are implemented. The aim is to achieve faster convergence in comparison to the Alternating algorithm from the previous paper. Methods such as the Landweber iteration, the Conjugate gradient method and the generalized minimal residual method are considered. We also discuss how the algorithms can be adapted to also cover the case of non–symmetric differential operators. 

    In Paper III, we look at a steady state heat conduction problem in a thin plate. The plate connects two cylindrical containers and fix their relative positions. A two dimensional mathematical model of heat conduction in the plate is derived. Since the plate has sharp edges on the sides we obtained a degenerate elliptic equation. We seek to find the temperature on the interior cylinder by using data on the exterior cylinder. We reformulate the Cauchy problem as an operator equation, with a compact operator. The operator equation is solved using the Landweber method and the convergence is investigated. 

    In Paper IV, the Cauchy problem for a more general degenerate elliptic equation is considered. We stabilize the computations using Tikhonov regularization. The normal equation, in the Tikhonov algorithm, is solved using the Conjugate gradient method. The regularization parameter is picked using either the L–curve or the Discrepancy principle. 

    In all papers, numerical examples are given where we solve the various boundary value problems using a finite difference scheme. The results show that the suggested methods work quite well. 

    List of papers
    1. Analysis of Dirichlet–Robin Iterations for Solving the Cauchy Problem for Elliptic Equations
    Open this publication in new window or tab >>Analysis of Dirichlet–Robin Iterations for Solving the Cauchy Problem for Elliptic Equations
    2021 (English)In: Bulletin of the Iranian Mathematical Society, ISSN 1735-8515, Vol. 47, p. 1681-1699Article in journal (Refereed) Published
    Abstract [en]

    The Cauchy problem for general elliptic equations of second order is considered. In a previous paper (Berntsson et al. in Inverse Probl Sci Eng 26(7):1062–1078, 2018), it was suggested that the alternating iterative algorithm suggested by Kozlov and Maz’ya can be convergent, even for large wavenumbers k2, in the Helmholtz equation, if the Neumann boundary conditions are replaced by Robin conditions. In this paper, we provide a proof that shows that the Dirichlet–Robin alternating algorithm is indeed convergent for general elliptic operators provided that the parameters in the Robin conditions are chosen appropriately. We also give numerical experiments intended to investigate the precise behaviour of the algorithm for different values of k2 in the Helmholtz equation. In particular, we show how the speed of the convergence depends on the choice of Robin parameters.

    Place, publisher, year, edition, pages
    Springer, 2021
    Keywords
    Helmholtz equation, Cauchy problem, Inverse problem, Ill-posed problem
    National Category
    Mathematical Analysis
    Identifiers
    urn:nbn:se:liu:diva-170834 (URN)10.1007/s41980-020-00466-7 (DOI)000575739300001 ()2-s2.0-85092146699 (Scopus ID)
    Available from: 2020-10-26 Created: 2020-10-26 Last updated: 2024-02-22Bibliographically approved
    2. Accelerated Dirichlet-Robin alternating algorithms for solving the Cauchy problem for the Helmholtz equation
    Open this publication in new window or tab >>Accelerated Dirichlet-Robin alternating algorithms for solving the Cauchy problem for the Helmholtz equation
    2021 (English)In: IMA Journal of Applied Mathematics, ISSN 0272-4960, E-ISSN 1464-3634, Vol. 86, no 6, p. 1181-1203Article in journal (Refereed) Published
    Abstract [en]

    The Cauchy problem for Helmholtz equation, for moderate wave number k(2), is considered. In the previous paper of Achieng et al. (2020, Analysis of Dirichlet-Robin iterations for solving the Cauchy problem for elliptic equations. Bull. Iran. Math. Soc.), a proof of convergence for the Dirichlet-Robin alternating algorithm was given for general elliptic operators of second order, provided that appropriate Robin parameters were used. Also, it has been noted that the rate of convergence for the alternating iterative algorithm is quite slow. Thus, we reformulate the Cauchy problem as an operator equation and implement iterative methods based on Krylov subspaces. The aim is to achieve faster convergence. In particular, we consider the Landweber method, the conjugate gradient method and the generalized minimal residual method. The numerical results show that all the methods work well. In this work, we discuss also how one can approach non-symmetric differential operators by similar operator equations and model problems which are used for symmetric differential operators.

    Place, publisher, year, edition, pages
    OXFORD UNIV PRESS, 2021
    Keywords
    Helmholtz equation; Cauchy problem; ill-posed; Dirichlet-Robin iterations; Krylov subspace methods
    National Category
    Computational Mathematics
    Identifiers
    urn:nbn:se:liu:diva-182796 (URN)10.1093/imamat/hxab034 (DOI)000743933700001 ()
    Available from: 2022-02-11 Created: 2022-02-11 Last updated: 2024-02-22
    3. Solving stationary inverse heat conduction in a thin plate
    Open this publication in new window or tab >>Solving stationary inverse heat conduction in a thin plate
    2023 (English)In: Partial Differential Equations and Applications, ISSN 2662-2971, Vol. 4, no 6Article in journal (Refereed) Published
    Abstract [en]

    We consider a steady state heat conduction problem in a thin plate. In the application, it is used to connect two cylindrical containers and fix their relative positions. At the same time it serves to measure the temperature on the inner cylinder. We derive a two dimensional mathematical model, and use it to approximate the heat conduction in the thin plate. Since the plate has sharp edges on the sides the resulting problem is described by a degenerate elliptic equation. To find the temperature in the interior part from the exterior measurements, we formulate the problem as a Cauchy problem for stationary heat equation. We also reformulate the Cauchy problem as an operator equation, with a compact operator, and apply the Landweber iteration method to solve the equation. The case of the degenerate elliptic equation has not been previously studied in this context. For numerical computation, we consider the case where noisy data is present and analyse the convergence.

    Keywords
    Cauchy problem, Stationary heat equation, Degenerate elliptic equation, Landweber iterative method
    National Category
    Mathematical Analysis
    Identifiers
    urn:nbn:se:liu:diva-201113 (URN)10.1007/s42985-023-00267-7 (DOI)
    Available from: 2024-02-22 Created: 2024-02-22 Last updated: 2024-02-22Bibliographically approved
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  • Chepkorir, Jennifer
    et al.
    Linköping University, Department of Mathematics, Analysis and Mathematics Education. Linköping University, Faculty of Science & Engineering. Department of Applied Mathematics, University of Nairobi, Nairobi, Kenya.
    Berntsson, Fredrik
    Linköping University, Department of Mathematics, Applied Mathematics. Linköping University, Faculty of Science & Engineering.
    Kozlov, Vladimir
    Linköping University, Department of Mathematics, Analysis and Mathematics Education. Linköping University, Faculty of Science & Engineering.
    Solving stationary inverse heat conduction in a thin plate2023In: Partial Differential Equations and Applications, ISSN 2662-2971, Vol. 4, no 6Article in journal (Refereed)
    Abstract [en]

    We consider a steady state heat conduction problem in a thin plate. In the application, it is used to connect two cylindrical containers and fix their relative positions. At the same time it serves to measure the temperature on the inner cylinder. We derive a two dimensional mathematical model, and use it to approximate the heat conduction in the thin plate. Since the plate has sharp edges on the sides the resulting problem is described by a degenerate elliptic equation. To find the temperature in the interior part from the exterior measurements, we formulate the problem as a Cauchy problem for stationary heat equation. We also reformulate the Cauchy problem as an operator equation, with a compact operator, and apply the Landweber iteration method to solve the equation. The case of the degenerate elliptic equation has not been previously studied in this context. For numerical computation, we consider the case where noisy data is present and analyse the convergence.

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  • Åkesson, Emilia
    Linköping University, Department of Behavioural Sciences and Learning, Education, Teaching and Learning. Linköping University, Faculty of Educational Sciences.
    The longing to just be – a belonging body in teacher education2024In: European Journal of Teacher Education, ISSN 0261-9768, E-ISSN 1469-5928Article in journal (Refereed)
    Abstract [en]

    This paper examines teacher education, with a focus on student experiences of comfort, discomfort, and sense of belonging or not belonging in the educational setting. The analysis is conducted with an intersectional corpomaterial perspective and based on 12 individual and two group interviews with student teachers, who identify as breaching norms within an intersectional power dynamic, or as interested in discussing such norms. The participants describe situations where they felt excluded and where they adjusted to try to fit their educational spaces. In contrast, some talk about a desirable, but rare, state of comfort, belonging or ?just being?. This state is intertwined with the spatiality and embodiment of class, racialisation, dis/ability and gender. The analysis challenges a dualistic understanding of comfort and discomfort in education, and shows how the participants? critique of teacher education could be formulated as a longing for, and a simultaneous production of, another kind of education.

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  • Rosenquist, Hampus
    Linköping University, Department of Computer and Information Science.
    Characterizing Bitcoin Use For Illicit Activities2023Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Bitcoin's decentralized nature enables reasonably anonymous exchange of money outside of the authorities' control. This has led to Bitcoin being popular for various illegal activities, including scams, ransomware attacks, money laundering, black markets, etc.  In this thesis, we characterize this landscape, providing insights into similarities and differences in the use of Bitcoin for such activities.  Our analysis and the derived insights contributes to the understanding of Bitcoin transactions associated with illegal activities through three main aspects. First, it offers a comprehensive characterization of money flows to and from Bitcoin addresses linked to different abuse categories, revealing variations in flow patterns and success rates. Second, a temporal analysis captures long-term trends and weekly patterns across categories. Finally, an analysis of outflow from reported addresses uncovers differences in graph properties and flow patterns among illicit addresses and between abuse categories. These findings provide valuable insights into the distribution, temporal dynamics, and interconnections within various categories of Bitcoin transactions related to illicit activities.

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  • Malmström, Magnus
    et al.
    Linköping University, Department of Electrical Engineering, Automatic Control. Linköping University, Faculty of Science & Engineering. The Swedish Defence Research Agency (FOI), Sweden.
    Kullberg, Anton
    Linköping University, Department of Electrical Engineering, Automatic Control. Linköping University, Faculty of Science & Engineering.
    Skog, Isaac
    Uppsala University, Sweden.
    Axehill, Daniel
    Linköping University, Department of Electrical Engineering, Automatic Control. Linköping University, Faculty of Science & Engineering.
    Gustafsson, Fredrik
    Linköping University, Department of Electrical Engineering, Automatic Control. Linköping University, Faculty of Science & Engineering.
    Extended Target Tracking Utilizing Machine-Learning Software–With Applications to Animal Classification2024In: IEEE Signal Processing Letters, ISSN 1070-9908, E-ISSN 1558-2361, Vol. 31, p. 376-380Article in journal (Refereed)
    Abstract [en]

    This letter considers the problem of detecting and tracking objects in a sequence of images. The problem is formulated in a filtering framework, using the output of object-detection algorithms as measurements. An extension to the filtering formulation is proposed that incorporates class information from the previous frame to robustify the classification. Further, the properties of the object-detection algorithm are exploited to quantify the uncertainty of the bounding box detection in each frame. The complete filtering method is evaluated on camera trap images of the four large Swedish carnivores, bear, lynx, wolf, and wolverine. The experiments show that the class tracking formulation leads to a more robust classification.

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  • Hosseini, Kian
    Linköping University, Department of Computer and Information Science.
    Real-Time System Benchmarking with Embedded Linux and RT Linux on a Multi-Core Hardware Platform2024Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    To catch up with the growing trend of parallelism, this thesis work focuses on the adaption of embedded real-time systems to a multicore platform. We use the embedded system of Xilinx ZCU-102, a multicore board, as an example of an embedded system without getting deep into its architecture. First, we deal with the tasks required to be able to make an embedded system operational and discuss why they are different from those for normal computer systems. The processes it takes to make a custom operating system for the given Xilinx embedded system are examined and patching the custom operating system along with customizing it is studied. We then take a look at related work in the field of benchmarking real-time systems and embedded systems and with a good understanding of related work propose a design similar to the related work for benchmarking embedded systems. The benchmarks we use run on multiple cores and aim at challenging the Xilinx board’s capabilities of running real-time tasks when the other cores on the board are occupied with performing independent tasks. We test the designed benchmarks on different conditions under two different operating systems of RT-Linux and Embedded Linux to study the differences between them. We then note how the RT-Linux would be a real upgrade for real-time systems if multicore operations are considered. The final result we have obtained is that core idling might decrease the performance of real-time tasks and RT-Linux might experience more interrupts but it is also better at recovering from interrupts.

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    Real-Time System Benchmarking with Embedded Linux and RT Linux on a Multi-Core Hardware Platform
  • Udała, Katarzyna Agnieszka
    Linköping University, Department of Thematic Studies.
    Exploring artificial intelligence bias: a comparative study of societal bias patterns in leading AI-powered chatbots.2023Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The development of artificial intelligence (AI) has revolutionised the way we interact with technology and each other, both in society and in professional careers. Although they come with great potential for productivity and automation, AI systems have been found to exhibit biases that reflect and perpetuate existing societal inequalities. With the recent rise of artificial intelligence tools exploiting the large language model (LLM) technology, such as ChatGPT, Bing Chat and Bard AI, this research project aims to investigate the extent of AI bias in said tools and explore its ethical implications. By reviewing and analysing responses to carefully crafted prompts generated by three different AI chatbot tools, the author will intend to determine whether the content generated by these tools indeed exhibits patterns of bias related to various social identities, as well as compare the extent to which such bias is present across all three tools. This study will contribute to the growing body of literature on AI ethics and inform efforts to develop more equitable and inclusive AI systems. By exploring the ethical dimensions of AI bias in selected LLMs, this research will shed light on the broader societal implications of AI and the role of technology in shaping our future.

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    AI_Bias_Chatbots_KUdala
  • Noori, Safa
    Linköping University, Department of Behavioural Sciences and Learning.
    Jag har ju lärt mig de här orden han säger ’khalas’ och ’maj’ och ’halib: En kvalitativ studie om förskollärares erfarenheter av arbetet med nyanlända barns språkutveckling.2022Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    I denna studie undersöker jag hur förskollärare, som arbetar i både privata och kommunala

    förskolor i en mellanstor stad i Sverige, beskriver och resonerar kring sitt arbetssätt med

    nyanlända och flerspråkiga barns språkutveckling. Syftet är att bidra med kunskap om

    språkutvecklande arbetssätt med nyanlända barn i förskolan. Studien presenterar de utmaningar

    som möter personal i förskolan när det gäller barns trygghet, kommunikation, deltagande och

    även när det gäller omsorg och lärande i förskolan. Metoden som jag använde till datainsamling

    var semistrukturerade intervjuar med förskollärarna från olika förskolor. Intervjuerna skedde

    skriftlig via mejlet och muntlig via Zoom. Både svensktalande förskollärare och förskollärare

    som har svenska som sitt andra språk intervjuades. Detta för att samla in olika synpunkter och

    perspektiv på arbetet med nyanlända barns språkutveckling. Studien fokuserar på arbetet med

    nyanlända barn med fokus på transpråkande, kultur och interkulturalitet. Avsikten är att veta

    hur mångfalden påverkar arbetet i förskolan. Det insamlade materialet har analyserats.

    Resultatet visar att pedagogerna anser sig arbeta på ett inkluderande förhållningssätt genom att

    lyfta alla språk och kulturer som finns i barngruppen. Pedagogerna resonerade kring

    möjligheter och utmaningar som de har i förskolan. Möjligheterna enligt förskollärarnas

    resonemang ligger i att pedagogerna som har samma modersmål underlättar arbetet med

    flerspråkighet i förskolan. Utmaningarna är svårigheter i att få tillgång till logopeder och

    specialpedagoger samt att det fattas tydliga riktlinjer i läroplanen om arbetet med nyanlända

    barns språkutveckling. Pedagogerna beskriver att de använder sig av både verbala och icke

    verbala kommunikationssätt i samspelet med nyanlända barn.

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