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  • Public defence: 2019-06-04 10:15 Ada Lovelace, Linköping
    Boström-Rost, Per
    Linköping University, Department of Electrical Engineering, Automatic Control. Linköping University, Faculty of Science & Engineering.
    On Informative Path Planning for Tracking and Surveillance2019Licentiate thesis, monograph (Other academic)
    Abstract [en]

    This thesis studies a class of sensor management problems called informative path planning (IPP). Sensor management refers to the problem of optimizing control inputs for sensor systems in dynamic environments in order to achieve operational objectives. The problems are commonly formulated as stochastic optimal control problems, where to objective is to maximize the information gained from future measurements. In IPP, the control inputs affect the movement of the sensor platforms, and the goal is to compute trajectories from where the sensors can obtain measurements that maximize the estimation performance. The core challenge lies in making decisions based on the predicted utility of future measurements.

    In linear Gaussian settings, the estimation performance is independent of the actual measurements. This means that IPP becomes a deterministic optimal control problem, for which standard numerical optimization techniques can be applied. This is exploited in the first part of this thesis. A surveillance application is considered, where a mobile sensor is gathering information about features of interest while avoiding being tracked by an adversarial observer. The problem is formulated as an optimization problem that allows for a trade-off between informativeness and stealth. We formulate a theorem that makes it possible to reformulate a class of nonconvex optimization problems with matrix-valued variables as convex optimization problems. This theorem is then used to prove that the seemingly intractable IPP problem can be solved to global optimality using off-the-shelf optimization tools.

    The second part of this thesis considers tracking of a maneuvering target using a mobile sensor with limited field of view. The problem is formulated as an IPP problem, where the goal is to generate a sensor trajectory that maximizes the expected tracking performance, captured by a measure of the covariance matrix of the target state estimate. When the measurements are nonlinear functions of the target state, the tracking performance depends on the actual measurements, which depend on the target’s trajectory. Since these are unavailable in the planning stage, the problem becomes a stochastic optimal control problem. An approximation of the problem based on deterministic sampling of the distribution of the predicted target trajectory is proposed. It is demonstrated in a simulation study that the proposed method significantly increases the tracking performance compared to a conventional approach that neglects the uncertainty in the future target trajectory.

  • Neshro, Barmano
    et al.
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Department of Internal Medicine, County Hospital Ryhov, Jönköping, Sweden,.
    Charitakis, Emmanouil
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Kronstrand, Robert
    Linköping University, Department of Medical and Health Sciences, Division of Drug Research. Linköping University, Faculty of Medicine and Health Sciences. National Board of Forensic Medicine, Linko¨ping, Sweden.
    Walfridsson, Ulla
    Linköping University, Department of Medical and Health Sciences, Division of Nursing Science. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Cardiology in Linköping.
    Karlsson, Jan-Erik
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Department of Internal Medicine, County Hospital Ryhov, Jönköping, Sweden.
    Walfridsson, Håkan
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Region Östergötland, Heart and Medicine Center, Department of Cardiology in Linköping. Linköping University, Faculty of Medicine and Health Sciences.
    Nyström, Fredrik
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Endocrinology.
    The association between alcohol consumption, cardiac biomarkers, left atrial size and re-ablation in patients with atrial fibrillation referred for catheter ablation2019In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 14, no 4, article id e0215121Article in journal (Refereed)
    Abstract [en]

    Background Information on alcohol consumption in patients undergoing radiofrequency ablation (RFA) of atrial fibrillation (AF) is often limited by the reliance on self-reports. The aim of this study was to describe the long-term alcohol consumption, measured as ethyl glucuronide in hair (hEtG), in patients undergoing RFA due to AF, and to examine potential associations with cardiac biomarkers, left atrial size and re-ablation within one year after the initial RFA. Methods The amount of hEtG was measured in patients referred for RFA, and a cut-off of 7 pg/mg was used. N-terminal pro B-type natriuretic peptide (NT-proBNP) and the mid-regional fragment of pro atrial natriuretic peptide (MR-proANP) were examined and maximum left atrium volume index (LAVI) was measured. The number of re-ablations was examined up to one year after the initial RFA. Analyses were stratified by gender, and adjusted for age, systolic blood pressure, body mass index, presence of heart failure and heart rhythm for analyses regarding NT-proBNP, MR-proANP and LAVI and heart rhythm being replaced by type of AF for analyses regarding re-ablation. Results In total, 192 patients were included in the study. Median (25th– 75th percentile) NT-proBNP in men with hEtG ≥ 7 vs. < 7 pg/mg was 250 (96–695) vs. 130 (49–346) pg/ml (p = 0.010), and in women it was 230 (125–480) vs. 230 (125–910) pg/ml (p = 0.810). Median MR-proANP in men with hEtG ≥ 7 vs. < 7 pg/mg was 142 (100–224) vs. 117 (83–179) pmol/l (p = 0.120) and in women it was 139 (112–206) vs. 153 (93–249) pmol/l (p = 0.965). The median of maximum LAVI was 30.1 (26.7–33.9) vs. 25.8 (21.4–32.0) ml/m2 (p = 0.017) in men, and 25.0 (18.9–29.6) vs. 25.7 (21.7–34.6) ml/m2 (p = 0.438) in women, with hEtG ≥ 7 vs. < 7 pg/ml, respectively. Adjusted analyses showed similar results, except for MR-proANP turning out significant in men with hEtG ≥ 7 vs. < 7 pg/mg (p = 0.047). The odds ratio of having a re-ablation was 3.5 (95% CI 1.3–9.6, p = 0.017) in men with hEtG ≥ 7 vs. < 7 pg/mg, while there was no significant difference in women. Conclusions In male patients with AF and hEtG ≥ 7 pg/mg, NT-proBNP and MR-proANP were higher, LA volumes larger, and there was a higher rate of re-ablations, as compared to men with hEtG < 7 pg/mg. This implies that men with an alcohol consumption corresponding to an hEtG-value ≥ 7, have a higher risk for LA remodelling that could potentially lead to a deterioration of the AF situation.

  • Neshro, Barmano
    et al.
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Department of Internal Medicine, County hospital Ryhov, Jönköping, Sweden;Jönköping Academy, Jönköping University,Jönköping, Sweden..
    Walfridsson, Ulla
    Linköping University, Department of Medical and Health Sciences, Division of Nursing Science. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Cardiology in Linköping.
    Walfridsson, Håkan
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Region Östergötland, Heart and Medicine Center, Department of Cardiology in Linköping. Linköping University, Faculty of Medicine and Health Sciences.
    Karlsson, Jan-Erik
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Department of Internal Medicine, County hospital Ryhov, Jönköping, Sweden;Jönköping Academy, Jönköping University,Jönköping, Sweden..
    Structured care of patients with atrial fibrillation improves guideline adherence2016In: Journal of Atrial Fibrillation, ISSN 1941-6911, Vol. 9, no 4Article in journal (Refereed)
    Abstract [en]

    There are many reports of lack of guideline adherence in the treatment of patients with atrial fibrillation (AF), and AF affects health-related quality of life (HRQoL) negatively. The aim of this study was to investigate whether structured care compared to standard care of a general AF population could improve guideline adherence and HRQoL, and reduce symptoms,anxiety and depression.

    Methods

    In total, 176 patients were recruited to the intervention and 146 patients to the control group.The intervention consisted of a structured follow-up program, while patients serving as controls received standard care. The primary outcome was guideline adherence evaluated through: appropriate use of oral anticoagulants (OAC) and antiarrhythmics, whether echocardiogram and thyroid lab tests were performed, and patient-reported outcome measures (PROMs), assessed with the questionnaires SF-36, EQ-5D, HADS and ASTA at baseline and after one year.

    Results

    Guideline adherence was significantly better in the intervention group, 91% vs. 63% (p < 0.01), mainly due to appropriate OAC treatment 94% vs. 74% (p < 0.01). Symptoms assessed with ASTA were less frequent and the negative impact of AF was reduced in the intervention group after one year/ at follow-up. Five scales in SF-36, and the visual analogue scale for current health status in EQ-5D (EQ-VAS), improved significantly in both groups.

    Conclusion

    Structured care of patients with AF significantly improved guideline adherence and patients reported fewer symptoms and a reduced negative impact on disease-specific HRQoL compared to standard care at one year follow-up.

  • Public defence: 2019-06-10 10:15 ACAS, A-huset, Linköping
    Lindsay Haldimann, Mirella
    Linköping University, Department of Management and Engineering. Linköping University, Faculty of Arts and Sciences.
    Business Model Design for Social Goods and Services in Developing Economies2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Over the past decade there have been increasing calls for alternative ways of tackling poverty problems in developing economies. Rather than aid or charity approaches that have traditionally dominated this area, an alternative line of discussion around base-of-the-pyramid approaches has emerged which emphasizes the role of innovation and pro-poor entrepreneurship. These developments are consequently reshaping our current views on organizational sectors, vulnerable communities, and sources of value creation.

    Social businesses trailblazing these approaches however may find it difficult to provide customers at the very base of the economic pyramid with products and services in financially sustainable ways. Markets in remote rural areas are characterized by severe resource scarcity and pervasive institutional voids which make the pursuit of designing adequate value creation and appropriation mechanisms a challenging undertaking. Additionally, the commercialization of social goods further compounds these challenges, because hybrid missions demand the simultaneous generation of social and commercial value.

    In this dissertation, I aim to shed light on these issues and examine how successful social businesses have emerged in the context of the unfolding pro-poor informal water market. This setting lent itself especially well to such study because the lack of safe and affordable water access prominently affects severely poor and secluded geographies to which sustainable solutions in profit, non-profit or governmental form have not yet emerged; yet successful solutions by social businesses have.

    Building on the emergent research on social businesses, I suggest that these organizations established viable business ventures by designing a type of business model that caters to the needs of socially constrained base-of-the-pyramid communities despite the afore-mentioned managerial challenges. With a focus on theory development, I employ a multi-qualitative approach consisting of multiple case studies to develop a conceptual framework of these social business models and various propositions as to what may underpin their successful development.

    The empirical foundation for these elaborations consists of five studies. These highlight distinct value creation and appropriation mechanisms as well as capabilities that social businesses employ to circumnavigate resource scarcity and institutional voids. Consequently, focusing on the design of value creation and appropriation mechanisms, we gain deeper insights as to why some social businesses may outperform other organizations. The thesis concludes with implications for base-of-the-pyramid, social entrepreneurship and business model literature, as well as avenues for future research. 

    List of papers
    1. Business model innovation in base of the pyramid markets
    Open this publication in new window or tab >>Business model innovation in base of the pyramid markets
    2017 (English)In: Journal of Business Strategy, ISSN 0275-6668, E-ISSN 2052-1197, Vol. 38, no 4, p. 38-46Article in journal (Refereed) Published
    Abstract [en]

    Purpose

    This paper aims to highlight how initial business models can be converted into a larger-scale solution for tapping into the emerging base-of-the-pyramid markets.

    Design/methodology/approach

    This study uses a qualitative, multi-case research design with 20 organizations tapping into the water market at the base-of-the-pyramid.

    Findings

    This paper explores three business models innovations: fostering value-in-context, allowing for modifiability and embracing organizational ambidexterity.

    Research limitations/implications

    Due to our qualitative research approach, generalizability of our findings is limited.

    Practical implications

    The description of the three business model innovations offers guidance for executives to make their business models financially more sustainable in base-of-the-pyramid markets.

    Social implications

    The water sector represents one especially interesting sector to examine business model innovations. For, among social goods, safe water remains a huge challenge to date where 700 million people remain without access to an improved water source.

    Originality/value

    Previous business model discussion in base-of-the-pyramid markets focuses on commercial goods. The authors focus on water as a social good. They demonstrate that the existing recommendations that business models in base-of-the-pyramid markets should be inclusive, complex, collaborative and scalable are mandatory, but not sufficient. In addition, business models should foster value-in-context, allow for modifiability and embrace organizational ambidexterity.

    Place, publisher, year, edition, pages
    Emerald, 2017
    Keywords
    Value-in-use, Business model innovation, Emerging market, Business models, Organizational ambidexterity, Base of the pyramid
    National Category
    Business Administration
    Identifiers
    urn:nbn:se:liu:diva-157028 (URN)10.1108/JBS-05-2016-0051 (DOI)
    Conference
    2019/05/23
    Available from: 2019-05-23 Created: 2019-05-23 Last updated: 2019-05-23
    2. Business model innovations for overcoming barriers in the base-of-the-pyramid market
    Open this publication in new window or tab >>Business model innovations for overcoming barriers in the base-of-the-pyramid market
    2017 (English)In: Industry and Innovation, ISSN 1366-2716, E-ISSN 1469-8390, Vol. 24, no 5, p. 543-568Article in journal (Refereed) Published
    Abstract [en]

    Many barriers must be overcome when entering the base-of-the-pyramid (BoP) market. Firms facing these barriers need to innovate new business models and reinvent existing ones to suit the BoP context. While previous literature has focused on the innovations of particular components of business models in BoP markets, we investigate the reconfigurations in the business model components that underpin the successful business model innovations. This study is based on multiple case studies in the water sector that we carried out in several different countries. Our findings suggest five business model innovations: (a) design, (b) renewal, (c) expansion, (d) diversification and (e) replication. Each business model innovation is a specific response to the barriers met in the BoP market and requires consistent configuration between its various components (i.e. value proposition, value creation and profit equation). These findings add, in two important aspects, to the academic realm of the business model domain: by contributing to the debate of business models in BoP markets and by advancing the configurational view of business models.

    Place, publisher, year, edition, pages
    ROUTLEDGE JOURNALS, TAYLOR & FRANCIS LTD, 2017
    Keywords
    Business models; business model innovations; base-of-the-pyramid markets; business model design; expansion; diversification; replication
    National Category
    Business Administration
    Identifiers
    urn:nbn:se:liu:diva-138308 (URN)10.1080/13662716.2017.1310033 (DOI)000400854600006 ()
    Conference
    DRUID Summer Conference
    Note

    Funding Agencies|Swiss Agency for Development and Cooperation

    Available from: 2017-06-13 Created: 2017-06-13 Last updated: 2019-05-23
  • Skoglund, Marcus
    Linköping University, Faculty of Arts and Sciences. Linköping University, Department of Management and Engineering, Commercial and Business Law.
    3:12-reglernas inverkan på generationsskiften: En analys av regeringens förslag om att införa ett undantag från bestämmelsen om samma eller likartad verksamhetvid ett ägarskifte till närstående2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Neutralitetsprincipen är en av de mest grundläggande byggstenarna inom den svenska skattelagstiftningen. Att enskildas handlingsalternativ inte skall styras av skatteutfallet var ett av de huvudsakliga ändamålen, tillsammans med grundidén om att motverka inkomstomvandling, vid genomförandet av århundradets skattereform i början på 1990-talet. Generationsskiftesförfarandet har dessvärre hamnat i kläm mellan strävan mot en neutral beskattning och strävan till att motverka inkomstomvandling. Problematiken grundar sig i bestämmelsen om samma eller likartad verksamhetsom återfinns i 57 kap. 4 § IL. Det är vanligt förekommande vid ägarskiften att överlåtaren vid en försäljning nyttjar sig av ett trädabolag. Det innebär att verksamhetsföretaget först överlåts till ett nybildat aktiebolag för att därefter avyttras till antingen närstående eller utomstående. De likvida medlen som finns kvar i trädabolaget efter försäljningen är skattefria, med anledning av att de avyttrade andelarna var näringsbetingade. Efter att bolaget legat fem år i karens är andelarna inte längre kvalificerade och vinstmedlen kan därefter tillgodogöras med en beskattning enbart i inkomstslaget kapital, det vill säga, utanför 3:12-reglernas räckvidd. Bestämmelsen om samma eller likartad verksamhetresulterar i att karenstiden om fem år för ett trädabolag aldrig börja löpa så länge en närstående bedriver samma eller likartad verksamhetsom andelsägaren. Andelarna i trädabolaget blir således aldrig av med sin klassificering som kvalificerade andelar och kan därmed inte avyttras som icke kvalificerade andelar, vilket hade varit möjligt om avyttring skett till utomstående. Det leder till att beskattningsutfallet ofta blir procentuellt högre vid en överlåtelse av ett fåmansföretag till närstående kontra överlåtelse till en extern part. Anledningen till att bestämmelsen om samma eller likartad verksamhetexisterar är för att närstående besitter en sådan närhet som generellt inte finns mellan utomstående. Systemet riskerar således att utnyttjas av närstående för att omvandla inkomst av tjänst till inkomst av kapital. Neutralitetsprincipen står därmed åt sidan för att premiera motarbetandet av inkomstomvandling. 

     

    Den 7 mars 2019 presenterade regeringen en proposition innehållande ett förslag om att införa ett undantag från bestämmelsen samma eller likartad verksamhetnär överlåtelse sker till närstående. Förslaget som regeringen föreslår presenterades som huvudförslag i SOU 2016:75,vars uppdrag var att se över beskattningen vid ägarskiften i fåmansföretag. I denna uppsats har en diskussion förts kring vilket förslag, regeringens eller de övriga av utredningen presenterade förslagen, som torde vara mest förenlig med en god skattelagstiftning och primärt neutralitetsprincipen. 

  • Public defence: 2019-06-14 10:00 I:101, I-huset, Linköping
    Åkerblom, Erika
    Linköping University, Department of Behavioural Sciences and Learning, Education and Adult Learning. Linköping University, Faculty of Educational Sciences. Avdelningen för utbildningsvetenskap, Akademin för utbildning och ekonomi, Gävle, Sverige.
    Utbildning och hälsa i nationens intresse: Styrningsteknologier och formering av en förädlad befolkning2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis consists of four articles about civic education in order to create a well-functioning nation. The purpose of the thesis is to problematise how education and health operate as governing technologies aimed at the population within today's refinement discourse. The theoretical and analytical framework is based on Foucault's concepts of governmentality, biopolitics, discourse analyse and genealogy. The empirical material consists, among other things, of official documents such as SOUs, project reports and web pages. The results show that even if the population and its problems are described as different, it is assumed to be based on, and originate from, ignorance. To address this, education and educative measures operates to create a well-functioning population. The citizens are governed and regulated by neoliberal governance, where techniques such as control and discipline enable mapping, educational efforts, categorisation and regulation. The healthy citizen is expected to be autonomous, to have the will to constantly learn and be healthy in accordance with the norm. 

    List of papers
    1. Constructing a healthy, knowledgeable and well-educated citizen: Motivational interviews and physical activity on prescription
    Open this publication in new window or tab >>Constructing a healthy, knowledgeable and well-educated citizen: Motivational interviews and physical activity on prescription
    2017 (English)In: Studies in Continuing Education, ISSN 0158-037X, E-ISSN 1470-126X, Vol. 39, no 3, p. 320-332Article in journal (Refereed) Published
    Abstract [en]

    In recent decades education has been suggested as an importantvsolution to current problems of the population’s health. A high level of education in general is construed as essential for the nation’s well-being and competitiveness. In this article we problematise the ways in which discourses on education, learning and health have become interlinked. Drawing on a post-structural theorisation inspired by Michel Foucault, we analyse Swedish policy documents on education and public health and direct our attention to how the healthy citizen is shaped and fostered. We illustrate how the healthy citizen emerges in opposition to the non-healthy, non-desirable and abnormal citizen. Citizens are made responsible for identifying their deficits and suggesting solutions. Governing techniques, such as motivational interviews and physical activity on prescription, operates in order to shape such citizens. Through these techniques, a confessional relation emerges, where citizens are invited to disclose their deficits and problems and in so doing shape themselves in a desired way.

    Keywords
    Education, Health, motivational interviews, physical activity on prescription, Foucault, Confession
    National Category
    Pedagogy
    Identifiers
    urn:nbn:se:liu:diva-138394 (URN)10.1080/0158037X.2017.1334641 (DOI)000410888200006 ()
    Available from: 2017-06-14 Created: 2017-06-14 Last updated: 2019-05-20
    2. Discourses of lifelong learning: health as a governing technique in the shaping of the Swedish population
    Open this publication in new window or tab >>Discourses of lifelong learning: health as a governing technique in the shaping of the Swedish population
    2019 (English)In: International Journal of Lifelong Education, ISSN 0260-1370, E-ISSN 1464-519X, p. 1-14Article in journal (Refereed) Published
    Abstract [en]

    This article focus on how the Swedish population is shaped into desirable citizens as resources for the nation?s prosperity. The aim is to analyse how health operates as a governing technique in discourses of lifelong learning. Within such current discourses the population is today described as generally well-educated and healthy, but not educated or healthy enough. When constructed as being in need of enhancement, measures of learning are suggested for regulating certain groups of the population into becoming what is regarded as desirable. Making use of Foucault?s notions of governmentality and genealogy, white and green papers from the Ministry of Health and Social Affairs from 1930s and today (2017) are analysed. The analysis shows that although the population is described as having different problems originating from ignorance, the solutions that are suggested in the different time periods are basically the same. The relation between learning and health is described in different ways in the 1930s and the present. In the 1930s learning is explained merely as a means to achieve a healthy population while in the present health is described both as a prerequisite and as an effect of learning. Further, there is also a difference in how the governing is conducted.

    Place, publisher, year, edition, pages
    Routledge, 2019
    National Category
    Learning
    Identifiers
    urn:nbn:se:liu:diva-156983 (URN)10.1080/02601370.2019.1592252 (DOI)
    Available from: 2019-05-20 Created: 2019-05-20 Last updated: 2019-05-20
  • Åkerblom, Erika
    Department of Educational Sciences, Faculty of Education and Business Studies, Gävle, Sweden.
    Discourses of lifelong learning: health as a governing technique in the shaping of the Swedish population2019In: International Journal of Lifelong Education, ISSN 0260-1370, E-ISSN 1464-519X, p. 1-14Article in journal (Refereed)
    Abstract [en]

    This article focus on how the Swedish population is shaped into desirable citizens as resources for the nation?s prosperity. The aim is to analyse how health operates as a governing technique in discourses of lifelong learning. Within such current discourses the population is today described as generally well-educated and healthy, but not educated or healthy enough. When constructed as being in need of enhancement, measures of learning are suggested for regulating certain groups of the population into becoming what is regarded as desirable. Making use of Foucault?s notions of governmentality and genealogy, white and green papers from the Ministry of Health and Social Affairs from 1930s and today (2017) are analysed. The analysis shows that although the population is described as having different problems originating from ignorance, the solutions that are suggested in the different time periods are basically the same. The relation between learning and health is described in different ways in the 1930s and the present. In the 1930s learning is explained merely as a means to achieve a healthy population while in the present health is described both as a prerequisite and as an effect of learning. Further, there is also a difference in how the governing is conducted.

  • Jakobsson, Jennie
    et al.
    Linköping University, Department of Social and Welfare Studies. Linköping University, Faculty of Educational Sciences.
    Lindroos, Richard
    Linköping University, Department of Social and Welfare Studies. Linköping University, Faculty of Educational Sciences.
    Kan musikundervisning gynna matematikinlärning?: En konsumtionsuppsats om hur musikutövande över tid kan stärka matematiska förmågor.2018Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Denna uppsats granskar forskning som gjorts kring kopplingar mellan musik och matematik i en didaktisk kontext och diskuterar hur sådana kopplingar kan användas i musikundervisning i årskurs 1–6 för att förbättra elevers matematikkunskaper. Syftet är att belysa likheter mellan musik och matematik och ta reda om och i så fall hur en konkretisering av och ett fokus på dessa likheter kan gynna elevers lärande i matematik.

    Resultatet visar att det finns flera olika sätt på vilka musikundervisning kan leda till att elever presterar bättre i matematik. Tydligast effekt verkar uppstå för lågpresterande elever och när likheter mellan ämnena uttrycks explicit. Några av de granskade studierna har inte sett samma effekt på lärande, medan andra ser endast en korrelation mellan musikutövande och matematikförmågor, alternativt upptäcker andra förmågor som möjligen medierar en effekt från musikutövande till matematikförmågor. Med hjälp av det sociokulturella perspektivet och Gardners teori om multipla intelligenser diskuteras vad som kan göra att effekten uppstår. Diskussionen leder fram till en modell som gör anspråk på att förklara att musikutövande över tid tillsammans med någon ytterligare påverkan kan leda till ökade matematiska förmågor.

  • Forslund, Matilda
    et al.
    Linköping University, Department of Behavioural Sciences and Learning, Education, Teaching and Learning. Linköping University, Faculty of Educational Sciences.
    Bartlewska, Dorota
    Linköping University, Department of Behavioural Sciences and Learning, Education, Teaching and Learning. Linköping University, Faculty of Educational Sciences.
    Nivågruppering inom matematikundervisning: framgångskoncept eller fiasko?: En systematisk litteraturstudie om hur elever påverkas av och upplever nivågruppering2019Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Denna systematiska litteraturstudie hade som syfte att undersöka vad tidigare forskning funnit gällande nivågrupperings inverkan på elevers prestationer, hur eleverna upplever nivågruppering och vilken undervisningstyp som bedrivs i de olika nivåerna inom matematikundervisning. Detta för att undersöka om nivågruppering skulle kunna vara en lösning inom matematikundervisningen gällande elevernas varierade kunskapsnivåer. Data samlades in från databasen ERIC och Linköpings Universitets egen söktjänst UniSearch. Resultatet visade att nivågruppering påverkar elevernas prestationer, akademiska självbild och deras aktivitetsgrad i klassrummet. Resultatet visade vidare att eleverna i de olika nivågrupperna upplever sin matematikundervisning på olika sätt. Vilken undervisningstyp som bedrivits inom de olika nivåerna i studierna var i de flesta fall ej specificerat. Detta problematiseras i diskussionen som en brist i den valda forskningen.

  • Lam, Benny
    et al.
    Linköping University, Department of Computer and Information Science.
    Nilsson, Jakob
    Linköping University, Department of Computer and Information Science.
    Creating Good User Experience in a Hand-Gesture-Based Augmented Reality Game2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The dissemination of new innovative technology requires feasibility and simplicity. The problem with marker-based augmented reality is similar to glove-based hand gesture recognition: they both require an additional component to function. This thesis investigates the possibility of combining markerless augmented reality together with appearance-based hand gesture recognition by implementing a game with good user experience.

    The methods employed in this research consist of a game implementation and a pre-study meant for measuring interactive accuracy and precision, and for deciding upon which gestures should be utilized in the game. A test environment was realized in Unity using ARKit and Manomotion SDK. Similarly, the implementation of the game used the same development tools. However, Blender was used for creating the 3D models.

    The results from 15 testers showed that the pinching gesture was the most favorable one. The game was evaluated with a System Usability Scale (SUS) and received a score of 70.77 among 12 game testers, which indicates that the augmented reality game, which interaction method is solely based on bare-hands, can be quite enjoyable.

  • Dahlstedt, Magnus
    et al.
    Linköping University, Department of Social and Welfare Studies, Social Work. Linköping University, Faculty of Arts and Sciences.
    Ekholm, David
    Linköping University, Department for Studies of Social Change and Culture, Centre for Municipality Studies – CKS. Linköping University, Faculty of Arts and Sciences.
    Midnattsfotboll – ett svar eller symptom på ojämlikhet?2019In: Idrotten och (o)jämlikheten – I medlemmarnas eller samhällets intresse? / [ed] Christine Dartsch, Johan R Norberg och Johan Pihlblad, Stockholm: Centrum för idrottsforskning , 2019, p. 109-130Chapter in book (Other academic)
  • Ekholm, David
    Linköping University, Department for Studies of Social Change and Culture, Centre for Municipality Studies – CKS. Linköping University, Faculty of Arts and Sciences.
    Idrott som lokal socialpolitik: Kommun och civilsamhälle i samverkan2019Report (Other academic)
    Abstract [sv]

    Den här rapporten presenterar resultat av en studie som bedrivits inom forskningsprojektet ”Idrott som en väg till social inkludering: styrning genom demokratisk fostran och organisatorisk samverkan”. I rapporten redovisas specifikt hur den idrottsbaserade sociala verksamheten midnattsfotboll har etablerats i två olika städer (”Västerstad” och ”Österstad”) i samverkan mellan idrottsföreningar, en nationell stiftelse och kommunerna i dessa städer. Midnattsfotboll är ett slags fotbollsverksamhet med sociala ändamål för ungdomar i åldern 12 till cirka 25 år som bedrivs under lördagskvällar i socioekonomiskt utsatta områden. Verksamheterna har följts framförallt genom intervjuer med företrädare för verksamheterna och observationer på plats.

    Syftet är att beskriva hur samverkan mellan olika aktörer både upplevs och går till i praktiken, identifiera olika förutsättningar för att kunna etablera verksamhet samt att bidra till reflektion kring vilken plats och betydelse en sådan verksamhet kan ha lokalt och politiskt.

    Rapporten vänder sig till läsare med intresse för kultur- och fritidsaktiviteter, såsom idrott, men särskilt till verksamma i beslutsfattande eller verksamhetsnära positioner i kommuner eller andra myndigheter, på idrottsförbund, i föreningar och i civilsamhället i allmänhet. Ambitionen med studien är att den kunskap som redovisas i rapporten ska kunna ligga till grund för både verksamhetsutveckling och diskussioner om kultur- och fritids liksom socialpolitik och betydelsen av idrott inom dessa politikområden.

    Rapporten behandlar återkommande flera viktiga teman som har med gränser och gränsöverskridanden att göra. Det gäller dels (sektors-) gränser mellan civilsamhällets aktörer och offentliga aktörer, och dels (administrativa) gränser mellan vad som uppfattas som olika politikområden, såsom kultur- och fritidspolitik och socialpolitik. Därtill bidrar studien med nära beskrivningar av hur arbetet med att utveckla en social verksamhet i samverkan mellan olika aktörer med olika bakgrunder tar form i praktiken.

    Bland de huvudsakliga resultat som rapporten bidrar med kan följande lyftas fram särskilt:

    • Verksamheternas etablering har sett väldigt olika ut i de två städerna trots liknande upplägg och relation till stiftelsen. Verksamheten i Västerstad har haft svårt att etablera sig långsiktigt och på ett formaliserat sätt; verksamheten i Österstad har etablerats tydligare och har dessutom kunnat utvecklas och expandera lokalt.
    • De båda verksamheterna har haft olika organisatoriska förutsättningar och ekonomiska möjligheter, vilket påverkat hur de utvecklats. Ekonomin är beroende av de organisatoriska förmågorna i verksamheterna. Mycket av kontinuiteten och engagemanget i verksamheterna bygger på ledarna och för att kunna rekrytera dem behövs ekonomiska resurser.
    • För att en verksamhet ska etableras lokalt är de specifika förutsättningarna både i städerna och i områdena där verksamheten bedrivs centrala. Det gäller dels ifråga om den befintliga föreningsverksamheten lokalt (som kan kanalisera verksamheter) och dels ifråga om möjligheter till stöd av politiska beslutsfattare och förvaltning på lokal nivå.
    • För att en verksamhet ska kunna etableras lokalt är det viktigt att det inte bara finns en utarbetad plan för själva fotbollsaktiviteten (praktik) utan även för organisation, ledning och samverkan med andra involverade aktörer (program). När en utarbetad plan för verksamhetens program saknas lokalt blir enskilda företrädare och ledares individuella förmågor att navigera i relation till andra aktörers viljor och organisationer avgörande. Detta gäller särskilt ifråga om strategisk kommunikation och förmåga att anpassa målbilder.
    • I de fall som kommuner vill stödja verksamheter som midnattsfotboll är det viktigt att reflektera kring sådana verksamheters politiska betydelse och deras potential för att uppnå politiska mål. Det gäller bland annat den mer generella betydelsen av samverkan med civilsamhället som utförare av tjänster och service, men det berör också avvägningar mellan professionella färdigheter och personliga egenskaper i sociala insatser och verksamheter. Projekt av det här slaget väcker också frågor om hur civilsamhällets (förmodade) självständighet kan värnas vid samverkansrelationer samt huruvida jämlik tillgång till idrottsaktiviteter för unga behöver motiveras med just socialpolitiska ändamål. Inte minst gäller det här att ha en rimlig tilltro till den kraft som tillskrivs just idrott ifråga om att bidra till integration och allmän samhällsutveckling. Inkludering i idrott (som ett mål i sig självt) behöver värderas i relation till tilltron till idrott som ett sätt (som ett verktyg) att skapa inkludering i samhället.
  • Santini, Marina
    et al.
    RISE Research Institutes of Sweden, Sweden.
    Jönsson, Arne
    Linköping University, Department of Computer and Information Science, Human-Centered systems. Linköping University, Faculty of Science & Engineering. RISE Research Institutes of Sweden, Sweden.
    Strandqvist, Wiktor
    Linköping University, Department of Computer and Information Science, Human-Centered systems. Linköping University, Faculty of Science & Engineering. RISE Research Institutes of Sweden, Sweden.
    Cederblad, Gustav
    Linköping University, Department of Computer and Information Science. Linköping University, Faculty of Science & Engineering.
    Nyström, Mikael
    Linköping University, Department of Biomedical Engineering, Division of Biomedical Engineering. Linköping University, Faculty of Science & Engineering. RISE Research Institutes of Sweden, Sweden.
    Alirezaie, Marjan
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Lind, Leili
    Linköping University, Department of Biomedical Engineering, Division of Biomedical Engineering. Linköping University, Faculty of Science & Engineering. RISE Research Institutes of Sweden, Sweden.
    Blomqvist, Eva
    Linköping University, Department of Computer and Information Science, Human-Centered systems. Linköping University, Faculty of Science & Engineering. RISE Research Institutes of Sweden, Sweden.
    Lindén, Maria
    Mälardalen University, Sweden.
    Kristoffersson, Annica
    Institutionen för naturvetenskap och teknik, Örebro universitet.
    Designing an Extensible Domain-Specific Web Corpus for “Layfication”: A Case Study in eCare at Home2019In: Cyber-Physical Systems for Social Applications / [ed] Maya Dimitrova and Hiroaki Wagatsuma, Hershey, PA, USA: IGI Global, 2019, p. 98-155Chapter in book (Refereed)
    Abstract [en]

    In the era of data-driven science, corpus-based language technology is an essential part of cyber physical systems. In this chapter, the authors describe the design and the development of an extensible domain-specific web corpus to be used in a distributed social application for the care of the elderly at home. The domain of interest is the medical field of chronic diseases. The corpus is conceived as a flexible and extensible textual resource, where additional documents and additional languages will be appended over time. The main purpose of the corpus is to be used for building and training language technology applications for the “layfication” of the specialized medical jargon. “Layfication” refers to the automatic identification of more intuitive linguistic expressions that can help laypeople (e.g., patients, family caregivers, and home care aides) understand medical terms, which often appear opaque. Exploratory experiments are presented and discussed.

  • Häggblom, Johan
    et al.
    Linköping University, Department of Electrical Engineering, Vehicular Systems.
    Jerner, Jonathan
    Linköping University, Department of Electrical Engineering, Vehicular Systems.
    Photovoltaic Power Production and Energy Storage Systems in Low-Voltage Power Grids2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In recent years, photovoltaic (PV) power production have seen an increase and the PV power systems are often located in the distribution grids close to the consumers. Since the distributions grids rarely are designed for power production, investigation of its effects is needed. It is seen in this thesis that PV power production will cause voltages to rise, potentially to levels exceeding the limits that grid owners have to abide by.

    A model of a distribution grid is developed in MathWorks MATLAB. The model contains a transformer, cables, households, energy storage systems (ESS:s) and photovoltaic power systems. The system is simulated by implementing a numerical Forward Backward Sweep Method, solving for powers, currents and voltages in the grid. PV power systems are added in different configurations along with different configurations of ESS:s. The results are analysed, primarily concerning voltages and voltage limits.

    It is concluded that addition of PV power production in the distribution grid affects voltages, more or less depending on where in the grid the systems are placed and what peak power they have. It is also concluded that having energy storage systems in the grid, changing the power factor of the inverter for the PV systems or lowering the transformer secondary-side voltage can bring the voltages down.

  • Samuelsson, Elin
    et al.
    Linköping University, Department of Social and Welfare Studies.
    Dobros, Christos
    Linköping University, Department of Social and Welfare Studies, Learning, Aesthetics, Natural science.
    Är det verkligen sant? Att hitta, sortera och värdera information i skolans undervisning: En litteraturstudie om hur skolan arbetar med källkritik, informationskompetens och kritiskt tänkande2018Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Det här är en systematisk litteraturstudie i syfte att utforska hur begreppen och förmågorna källkritik, informationskompetens och kritiskt tänkande tas upp och arbetas med i dagens skola. Vi har här utgått från tre frågeställningar som är: Hur arbetar lärare och elever med att utveckla sin informationskompetens i grundskolan? Vilka undervisningsstrategier används i dagens skola om källkritik och kritiskt tänkande? Varför bör skolan och lärare undervisa i källkritik och kritiskt tänkande? Vi har i denna studie använt oss av databassökning och manuell sökning för att få fram ett sådant bra utbud av litteratur som möjligt. Resultatet av forskningen visade att dessa begrepp är svåra att arbeta med då de är ytterst komplexa. Lärare bör ha dessa begrepp i åtanke under all typ av undervisning som sker i skolan då det har blivit allt viktigare att vara källkritiskt och ha ett kritiskt tänkande i dagens samhälle. Det framgick även i studien att lärare och bibliotekarier anser att det är svårt att veta vems ansvar det är att lära ut om dessa begrepp/förmågor.

  • Jern, Robin
    et al.
    Linköping University, Department of Behavioural Sciences and Learning, Education, Teaching and Learning. Linköping University, Faculty of Educational Sciences.
    Gröndahl, Emelie
    Linköping University, Department of Behavioural Sciences and Learning, Education, Teaching and Learning. Linköping University, Faculty of Educational Sciences.
    Programmering i matematikundervisningen: Vilka effekter har programmering på elevers lärande i matematikundervisningen i lägre åldrar?2019Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Syftet med den här studien har varit att ta reda på vilka fördelar det finns med att implementera programmering i matematikundervisningen. För att ta reda på detta har vi letat fram ett flertal olika studier som berör programmering inom skolväsendet på något sätt. För att hitta dessa studier har vi sökt i olika databaser efter relevanta artiklar. Dessa har vi valt utifrån valda kriterier.

    I studierna som vi har tagit del av användes både digital programmering, Scratch och LOGO, samt fysisk programmering, Bee-Bots. Resultatet av vår studie har visat att flera av elevernas matematiska förmågor gynnas av att arbeta med programmering i matematiken. I de flesta fallen visade studierna att eleverna fick ännu bättre resultat i jämförelse med traditionella metoder. Förmågorna som eleverna utvecklade var bland annat: aritmetik, problemlösningsförmåga, spatialt tänkande, algoritmer och resonemangsförmåga. Utöver elevernas matematiska förmågor visade det sig även att programmeringsövningar hade en positiv inverkan på elevernas motivation och intresse. Detta kan i sin tur leda till indirekta positiva effekter på elevernas lärande.

  • Public defence: 2019-06-07 10:15 Planck, Fysikhuset, Linköping
    Persson, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    Surface characterization of 2D transition metal carbides (MXenes)2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Research on two-dimensional (2D) materials is a rapidly growing field owing to the wide range of new interesting properties found in 2D structures that are vastly different from their three-dimensional (3D) analogues. In addition, 2D materials embodies a significant surface area that facilitates a high degree of surface reactions per unit volume or mass, that is imperative in many applications such as catalysis, energy storage, energy conversion, filtration, and single molecule sensing. MXenes constitute a family of 2D materials consisting of transition metal carbides and/or nitrides, which are typically formed after selective etching of their 3D parent MAX phases. The latter, are a family of nanolaminated compounds that typically follow the formula Mn+1AXn (n=1-3), where M is a transition metal, A is a group 13 or 14 element, and X is C and or N. Selective etching by aqueous F- containing acids removes the A layer leaving 2D Mn+1Xn slabs instantly terminated by a mix of O-, OH- and F-groups. The first and most investigated MXene is Ti3C2TX, where TX stands for surface termination, which has shown record properties in a range of applications (eg. electrode in Li-batteries, supercapacitors, sieving membrane, electromagnetic interference shielding, and carbon capture). Adding to that, over 30 different MXenes have been discovered since 2011, exhibiting alternative or superior properties. Most importantly, elegant routes for property design in the MXene family has been demonstrated, by means of either varying the chemistry in the Mn+1Xn compound, by alloying two M elements, or by changing the structure of the MXene by introducing vacancies.

    The present work has a led to an additional route for post synthesis property tuning in MXenes by manipulation of surface termination elements. This enables a unique toolbox for property tuning which is not available to other 2D materials and is highly beneficial for applications that is dependent on surface reactions. Furthermore, chemical and structural characterization of terminations on single sheets is essential to rule out the influence of intercalants or contamination that is typically present in multilayer MXene samples or thin films. For that purpose, a method for preparing isolated contamination free single sheets of MXene samples for transmission electron microscopy (TEM) characterization was established. In order to determine vacancy and termination sites, atomically resolved scanning (S)TEM imaging and image simulations was carried out. Two main processes were employed to substitute the termination elements.

    1) An initial thermal treatment in vacuum facilitates F desorption and it was shown that O-terminations rearranges on the evacuated sites. H2 gas exposure in a controlled environment demonstrated a removal of the remaining O-terminations. As a result, termination-free MXene is possible to realize under vacuum conditions.

    2) CO2 was introduced as a first non-inherent termination on MXene by in situ CO2 gas exposure at low temperatures. That was a first demonstration of Ti3C2TX as promising material for carbon capture. Additionally, O-saturated surfaces were demonstrated after introduction of O2 gas on the F-depleted Ti3C2TX MXene, which is highly relevant for hydrogen evolution reactions where fully O-terminated Ti3C2TX are predicted to improve efficiency.

    A Lewis acid melt synthesis method was used to realize the first MXene exclusively terminated with Cl. Moreover, this was the first report of a MXene directly synthesised with terminations other than O, OH, and F.

    Furthermore, we have expanded the space of property tuning by introduction of chemical ordering, by selective etching of Y in an alloyed (Mo2/3Y1/3)2CTX MXene. This either produced chemical ordering with one M (Mo) element and vacancies, or ordering between two M (Mo and Y) elements. This was further reported to significantly increase volumetric capacitance because of the increased number of active sites around vacancies, leading to an increasing charge density. As a final note, the stability of Nb2CTX MXene under ambient conditions was investigated. It was found that the surface Nb adatoms, present after etching, got oxidized over time which resulted in local clustering and effectively degraded the MXene.

    This work has demonstrated reproducible surface characterization methods for determining termination elements and sites in 2D MXenes, that is ultimately governing MXene properties. Most importantly, we report on a new approach for MXene property tuning as well as contributing to several existing property tuning approaches. 

    List of papers
    1. On the organization and thermal behavior of functional groups on Ti3C2 MXene surfaces in vacuum
    Open this publication in new window or tab >>On the organization and thermal behavior of functional groups on Ti3C2 MXene surfaces in vacuum
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    2018 (English)In: 2D MATERIALS, ISSN 2053-1583, Vol. 5, no 1, article id 015002Article in journal (Refereed) Published
    Abstract [en]

    The two-dimensional (2D) MXene Ti(3)C(2)Tx is functionalized by surface groups (T-x) that determine its surface properties for, e.g. electrochemical applications. The coordination and thermal properties of these surface groups has, to date, not been investigated at the atomic level, despite strong variations in the MXene properties that are predicted from different coordinations and from the identity of the functional groups. To alleviate this deficiency, and to characterize the functionalized surfaces of single MXene sheets, the present investigation combines atomically resolved in situ heating in a scanning transmission electron microscope (STEM) and STEM simulations with temperature-programmed x-ray photoelectron spectroscopy (TP-XPS) in the room temperature to 750 degrees C range. Using these techniques, we follow the surface group coordination at the atomic level. It is concluded that the F and O atoms compete for the DFT-predicted thermodynamically preferred site and that at room temperature that site is mostly occupied by F. At higher temperatures, F desorbs and is replaced by O. Depending on the O/F ratio, the surface bare MXene is exposed as F desorbs, which enables a route for tailored surface functionalization.

    Place, publisher, year, edition, pages
    Institute of Physics Publishing (IOPP), 2018
    Keywords
    MXene; Ti3C2Tx in situ heating; STEM; temperature-programmed XPS; surface functionalization
    National Category
    Materials Chemistry
    Identifiers
    urn:nbn:se:liu:diva-142131 (URN)10.1088/2053-1583/aa89cd (DOI)000412302100002 ()
    Note

    Funding Agencies|Swedish Research Council [621-20124359, 622-2008-405, 2013-5580, 2016-04412, 642-2013-8020]; Knut and Alice Wallenbergs Foundation [KAW 2015.0043]; Swedish Foundation for Strategic Research (SSF) [RIF14-0074]; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University [2009 00971]

    Available from: 2017-10-24 Created: 2017-10-24 Last updated: 2019-05-15Bibliographically approved
    2. 2D Transition Metal Carbides (MXenes) for Carbon Capture
    Open this publication in new window or tab >>2D Transition Metal Carbides (MXenes) for Carbon Capture
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    2019 (English)In: Advanced Materials, ISSN 0935-9648, E-ISSN 1521-4095, Vol. 31, no 2, article id 1805472Article in journal (Refereed) Published
    Abstract [en]

    Global warming caused by burning of fossil fuels is indisputably one of mankinds greatest challenges in the 21st century. To reduce the ever-increasing CO2 emissions released into the atmosphere, dry solid adsorbents with large surface-to-volume ratio such as carbonaceous materials, zeolites, and metal-organic frameworks have emerged as promising material candidates for capturing CO2. However, challenges remain because of limited CO2/N-2 selectivity and long-term stability. The effective adsorption of CO2 gas (approximate to 12 mol kg(-1)) on individual sheets of 2D transition metal carbides (referred to as MXenes) is reported here. It is shown that exposure to N-2 gas results in no adsorption, consistent with first-principles calculations. The adsorption efficiency combined with the CO2/N-2 selectivity, together with a chemical and thermal stability, identifies the archetype Ti3C2 MXene as a new material for carbon capture (CC) applications.

    Place, publisher, year, edition, pages
    WILEY-V C H VERLAG GMBH, 2019
    Keywords
    carbon capture; environmental TEM; MXene; surface terminations
    National Category
    Materials Chemistry
    Identifiers
    urn:nbn:se:liu:diva-154119 (URN)10.1002/adma.201805472 (DOI)000455111100003 ()30393920 (PubMedID)
    Note

    Funding Agencies|Swedish Research Council [2016-04412, 2016-00889, 642-2013-8020]; Knut and Alice Wallenbergs Foundation [KAW 2015.0043]; Swedish Foundation for Strategic Research (SSF) [EM16-0004, RIF 14-0074, FL12-0181]; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University (Faculty Grant SFO-Mat-LiU) [2009 00971]

    Available from: 2019-01-29 Created: 2019-01-29 Last updated: 2019-05-15Bibliographically approved
    3. Tailoring Structure, Composition, and Energy Storage Properties of MXenes from Selective Etching of In-Plane, Chemically Ordered MAX Phases
    Open this publication in new window or tab >>Tailoring Structure, Composition, and Energy Storage Properties of MXenes from Selective Etching of In-Plane, Chemically Ordered MAX Phases
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    2018 (English)In: Small, ISSN 1613-6810, E-ISSN 1613-6829, Vol. 14, no 17, article id 1703676Article in journal (Refereed) Published
    Abstract [en]

    The exploration of 2D solids is one of our times generators of materials discoveries. A recent addition to the 2D world is MXenes that possses a rich chemistry due to the large parent family of MAX phases. Recently, a new type of atomic laminated phases (coined i-MAX) is reported, in which two different transition metal atoms are ordered in the basal planes. Herein, these i-MAX phases are used in a new route for tailoriong the MXene structure and composition. By employing different etching protocols to the parent i-MAX phase (Mo2/3Y1/3)(2)AlC, the resulting MXene can be either: i) (Mo2/3Y1/3)(2)C with in-plane elemental order through selective removal of Al atoms or ii) Mo1.33C with ordered vacancies through selective removal of both Al and Y atoms. When (Mo2/3Y1/3)(2)C (ideal stoichiometry) is used as an electrode in a supercapacitor-with KOH electrolytea volumetric capacitance exceeding 1500 F cm(-3) is obtained, which is 40% higher than that of its Mo1.33C counterpart. With H2SO4, the trend is reversed, with the latter exhibiting the higher capacitance (approximate to 1200 F cm(-3)). This additional ability for structural tailoring will indubitably prove to be a powerful tool in property-tailoring of 2D materials, as exemplified here for supercapacitors.

    Place, publisher, year, edition, pages
    WILEY-V C H VERLAG GMBH, 2018
    Keywords
    2D materials; capacitance; in-plane order; MXene; vacancies
    National Category
    Materials Chemistry
    Identifiers
    urn:nbn:se:liu:diva-147926 (URN)10.1002/smll.201703676 (DOI)000430922100010 ()29611285 (PubMedID)
    Note

    Funding Agencies|Swedish Research Council [2016-04412, 621-2012-4359, 622-2008-405, 2013-5580, 642-2013-8020, 2016-00889]; Knut and Alice Wallenbergs Foundation [KAW 2015.0043]; Swedish Foundation for Strategic Research (SSF) through the Synergy Grant FUNCASE; Swedish Foundation for Strategic Research (SSF) [RIF 14-0074]; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University (Faculty Grant SFO-Mat-LiU) [2009 00971]

    Available from: 2018-05-23 Created: 2018-05-23 Last updated: 2019-05-15
    4. On the Structural Stability of MXene and the Role of Transition Metal Adatoms
    Open this publication in new window or tab >>On the Structural Stability of MXene and the Role of Transition Metal Adatoms
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    2018 (English)In: Nanoscale, ISSN 2040-3364, E-ISSN 2040-3372, Vol. 10, no 23, p. 10850-10855Article in journal (Refereed) Published
    Abstract [en]

    In the present communication, the atomic structure and coordination of surface adsorbed species on Nb2C MXene is investigated over time. In particular, the influence of the Nb adatoms on the structural stability and oxidation behavior of the MXene is addressed. This investigation is based on plan-view geometry observations of single Nb2C MXene sheets by a combination of atomic-resolution scanning transmission electron microscopy (STEM), electron energy loss spectroscopy (EELS) and STEM image simulations.

    Place, publisher, year, edition, pages
    Royal Society of Chemistry, 2018
    Keywords
    2D material; MXene; Scanning Transmission Electron Microscopy; Structural Stability; Adatoms
    National Category
    Chemical Sciences
    Identifiers
    urn:nbn:se:liu:diva-148143 (URN)10.1039/C8NR01986J (DOI)000435358600004 ()29870038 (PubMedID)
    Note

    Funding agencies:The authors acknowledge the Swedish Research Council for funding under grants no. 2016- 04412 and 642-2013-8020, the Knut and Alice Wallenberg’s Foundation for support of the electron microscopy laboratory in Linköping, a Fellowship grant and a project grant (KAW 2015.0043). The authors also acknowledge Swedish Foundation for Strategic Research (SSF) through the Research Infrastructure Fellow program no. RIF 14-0074. The authors finally acknowledge support from the Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linköping University (Faculty Grant SFO-Mat-LiU No 2009 00971

    Available from: 2018-05-31 Created: 2018-05-31 Last updated: 2019-05-20Bibliographically approved
  • Roxbo, Daniel
    Linköping University, Department of Computer and Information Science, Human-Centered systems.
    A Detailed Analysis of Semantic Dependency Parsing with Deep Neural Networks2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The use of Long Short Term Memory (LSTM) networks continues to yield better results in natural language processing tasks. One area which recently has seen significant improvements is semantic dependency parsing, where the current state-of-the-art model uses a multilayer LSTM combined with an attention-based scoring function to predict the dependencies.

    In this thesis the state of the art model is first replicated and then extended to include features based on syntactical trees, which was found to be useful in a similar model. In addition, the effect of part-of-speech tags is studied.

    The replicated model achieves a labeled F1 score of 93.6 on the in-domain data and 89.2 on the out-of-domain data on the DM dataset, which shows that the model is indeed replicable. Using multiple features extracted from syntactic gold standard trees of the DELPH-IN Derivation Tree (DT) type increased the labeled scores to 97.1 and 94.1 respectively, while the use of predicted trees of the Stanford Basic (SB) type did not improve the results at all. The usefulness of part-of-speech tags was found to be diminished in the presence of other features.

  • Lindell, Elin
    et al.
    Linköping University, Department of Social and Welfare Studies, Learning, Aesthetics, Natural science.
    Steisjö, Julia
    Linköping University, Department of Social and Welfare Studies, Learning, Aesthetics, Natural science.
    I skuggan av ett ljus: En systematisk litteraturstudie med fokus på barns uppfattningar om ljus och skuggor2019Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    According to previous research, young children ́s perceptions of light and shadows are often based on everyday experiences. This study is a systematic literature review aiming to investigate and analyse previous empirical research of children ́s perceptions of light and shadows and the role representations have on teaching in the subject. The report was conducted in response to what characterizes children's understanding of light and shadows and how children's knowledge and understanding of physical concepts and phenomena are affected by the use of varied forms of representations in teaching.

    In this systematic literature review different databases were used to search for previous research, such as ERIC and Swepub. To narrow down the results from the database searches the following limiters were used: peer reviewed articles and published year 2007 – 2018. Results from previous research, within the scope of the purpose for this report, have systematically been analysed and critically reviewed. A total of 12 peer-reviewed, international articles have been analysed which indicates that children at an early age have perceptions of light and shadows. However, the results indicate also that children have a primitive approach in explaining light and shadows. Results from the articles revealed that the teacher has an important role regarding children's learning. Also, the majority of articles described the importance of representations in the development of children's understanding of natural sciences. The conclusion is therefore that the teacher can provide children with meaning and context by utilizing the children ́s conceptions of light and shadows and by using varying forms of representations. Lastly, as an implication for further research it is suggested to empirically examine the teaching contents of light and shadows in year F-3, in order to obtain new perspectives and opportunities for development in the field of light and shadows.

  • Public defence: 2019-06-07 09:00 Originalet, Jönköping
    Axelsson, Daniel
    Linköping University, Department of Clinical and Experimental Medicine, Division of Children's and Women's health. Linköping University, Faculty of Medicine and Health Sciences. Department of Obstetrics and Gynecology, Ryhov County Hospital, Jönköping.
    Postpartum infections; prevalence, associated obstetric factors and the role of vitamin D2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Background: Postpartum infections are a major cause of maternal mortality and morbidity worldwide. Breast infection, endometritis, urinary tract infection and wound infections are the most common postpartum infections and together they affect almost 20% of women after childbirth. Some risk factors for postpartum infections, for example cesarean section, have been relatively well studied, but other presumable risk factors are yet to be confirmed.

    The proportion of pregnant women who are overweight or obese is increasing in most parts of the world. Increased maternal body mass index (BMI) is associated with maternal and infant morbidity. The association between overweight / obesity and postpartum infections is incompletely understood. Vitamin D deficiency has in epidemiological studies been shown to increase the risk of various infections. Furthermore, vitamin D is an important factor in the human immune system. Concomitantly, vitamin D supplementation seems protective against some types of infections. Whether vitamin D deficiency is a risk factor for postpartum infections has not been studied.

    Material and Methods: In a population-based observational study using questionnaires, the prevalences of postpartum wound infections, endometritis, urinary tract infections and mastitis in the southeast region of Sweden were estimated (Paper I). All women giving birth in the region during one year (n=11 124) were asked to participate. Papers II and III were cohort studies based on all deliveries in Sweden during eight years (2005-2012). Data sources were the Swedish Medical Birth Register, the Swedish National Patient Register and the Swedish Prescribed Drugs Register. In paper II all term deliveries were included (n=795 072). Risk factors for postpartum wound infections, endometritis and urinary tract infection were evaluated. Paper III included all deliveries (n=841 780) and examined the impact of BMI on the risk of postpartum wound infections, endometritis and breast abscess after different modes of delivery. Infections were defined as the presence of applicable ICD-10 codes. The Mantel-Haenszel technique was used to calculate adjusted odds ratios. In paper IV the association between vitamin D deficiency and overall postpartum infectious morbidity was analyzed. Serum samples from the Pregnancy Biobank in Linköping, drawn at the time of delivery, were used to determine concentrations of 25-hydroxyvitamin D in 1397 women. ICD-10 codes were extracted from the women’s medical records. The prevalence of vitamin D deficiency was calculated and adjusted odds ratios for postpartum infections were estimated with multivariable logistic regression analysis.

    Results: More than one out of ten women in southeast Sweden reported wound infections; endometritis, urinary tract infection or mastitis postpartum and 7.5% reported antibiotic treatment for infection. Cesarean section was the strongest risk factor for wound infection, followed by obstetric anal sphincter injuries and episiotomy. For endometritis, the strongest risk factors were anemia, manual placental removal and emergency cesarean section. Urinary tract infection was associated with anemia, instrumental vaginal delivery and emergency cesarean section. There was a dose-dependent increased risk of postpartum infection with higher BMI. For morbidly obese women the risk of infection was over 50% higher than for normal weight women. The risk of endometritis after normal vaginal delivery increased the higher the BMI, as did the risk of wound infection after cesarean section, regardless of the type of cesarean section. For breast abscess, there was an inverse association with BMI.

    Vitamin D deficiency was present among almost 60% of pregnant women at the time of delivery. No association between vitamin D deficiency and postpartum infections was found.

    Conclusions: Every tenth Swedish woman acquired an infection postpartum and three quarters of them received antibiotics for infection. Anemia was an important risk factor for postpartum infection, and the strongest risk factor for endometritis and urinary tract infection. Strong efforts should be made to reduce blood loss during and after childbirth. This thesis confirmed cesarean section as a major risk factor for postpartum infection, especially wound infection. The risk increased if the woman was overweight or obese, regardless of whether it was a planned or an emergency cesarean section.

    Vitamin D deficiency was common among Swedish pregnant women, but it was not found to be associated with postpartum infections.

    List of papers
    1. Prevalence of postpartum infections: a population-based observational study
    Open this publication in new window or tab >>Prevalence of postpartum infections: a population-based observational study
    2014 (English)In: Acta Obstetricia et Gynecologica Scandinavica, ISSN 0001-6349, E-ISSN 1600-0412, Vol. 93, no 10, p. 1065-1068Article in journal (Refereed) Published
    Abstract [en]

    We investigated the prevalence of postpartum infections among women giving birth during 1year in a population-based observational/questionnaire study at seven hospitals in the southeast region of Sweden. Of the women greater than99% (n=11124) received a questionnaire to inquire if they had endometritis, mastitis, or wound, urinary tract or any other infection within 2months postpartum and whether they received antibiotics for this. Prevalence rates for infections and antibiotic treatment were estimated. The response rate was 60.1%. At least one infectious episode was reported by 10.3% of the women and 7.5% had received antibiotics. The prevalence for infections with and without antibiotics were, respectively, mastitis 4.7% and 2.9%, urinary tract infection 3.0% and 2.4%, endometritis 2.0% and 1.7%, wound infection 1.8% and 1.2%. There was no inter-county difference in infection prevalence. Clinical postpartum infections in a high-resource setting are relatively common.

    Place, publisher, year, edition, pages
    Informa Healthcare / Wiley: 12 months, 2014
    Keywords
    Infections; postpartum; mastitis; urinary tract infection; endometritis; wound infection
    National Category
    Obstetrics, Gynecology and Reproductive Medicine
    Identifiers
    urn:nbn:se:liu:diva-111744 (URN)10.1111/aogs.12455 (DOI)000342582800016 ()25132521 (PubMedID)
    Note

    Funding Agencies|Medical Research Council of Southeast Sweden

    Available from: 2014-10-31 Created: 2014-10-31 Last updated: 2019-05-15
    2. Postpartum infection in relation to maternal characteristics, obstetric interventions and complications
    Open this publication in new window or tab >>Postpartum infection in relation to maternal characteristics, obstetric interventions and complications
    2018 (English)In: Journal of Perinatal Medicine, ISSN 0300-5577, E-ISSN 1619-3997, Vol. 46, no 3, p. 271-278Article in journal (Refereed) Published
    Abstract [en]

    The purpose was to evaluate the association between maternal characteristics, obstetrical interventions/complications and postpartum wound infections (WI), urinary tract infection (UTI) and endometritis. Furthermore, this study aimed to determine the time from delivery to onset of infections after discharge from the hospital. Three large Swedish Medical Health Registers were scrutinized for the period 2005-2012. A total of 582,576 women had 795,072 deliveries. Women with diagnosis codes for WIs, UTIs or endometritis, from delivery to 8 weeks postpartum, were compared to non-infected women. Adjusted odds ratios (OR) and 95% confidence intervals (CI) were estimated. Increasing age and body mass index (BMI) were both associated with increasing prevalence of postpartum infections. WIs were most strongly associated with cesarean section (CS) (OR 17.2; 95% CI 16.1-18.3), 3rd and 4th degree tears (OR 10.7%; 95% CI 9.80-11.9) and episiotomy (OR 10.2; 95% CI 8.94-11.5). Endometritis was associated with anemia (OR 3.16; 95% CI 3.01-3.31) and manual placental removal (OR 2.72; 95% CI 2.51-2.95). UTI was associated with emergency CS (OR 3.46; 95% CI 3.07-3.89) and instrumental delivery (OR 3.70; 95% CI 3.29-4.16). For women discharged from the delivery hospital the peak occurrence of UTI was 6 days postpartum, while for WIs and endometritis it was 7 days postpartum.

    Place, publisher, year, edition, pages
    WALTER DE GRUYTER GMBH, 2018
    Keywords
    Anemia; cesarean; endometritis; postpartum infection; urinary tract infection; wound infection
    National Category
    Obstetrics, Gynecology and Reproductive Medicine
    Identifiers
    urn:nbn:se:liu:diva-147575 (URN)10.1515/jpm-2016-0389 (DOI)000429429900006 ()28672754 (PubMedID)
    Note

    Funding Agencies|Futurum - the academy for healthcare, Region Jonkoping County, Sweden

    Available from: 2018-04-26 Created: 2018-04-26 Last updated: 2019-05-15
  • Public defence: 2019-06-12 10:15 Ada Lovelace, Linköping
    Larsson, Roger
    Linköping University, Department of Electrical Engineering, Automatic Control. Linköping University, Faculty of Science & Engineering.
    Flight Test System Identification2019Doctoral thesis, monograph (Other academic)
    Abstract [en]

    With the demand for more advanced fighter aircraft, relying on unstable flight mechanical characteristics to gain flight performance, more focus has been put on model-based system engineering to help with the design work. The flight control system design is one important part that relies on this modeling. Therefore, it has become more important to develop flight mechanical models that are highly accurate in the whole flight envelope. For today’s modern fighter aircraft, the basic flight mechanical characteristics change between linear and nonlinear as well as stable and unstable as an effect of the desired capability of advanced maneuvering at subsonic, transonic and supersonic speeds.

    This thesis combines the subject of system identification, which is the art of building mathematical models of dynamical systems based on measurements, with aeronautical engineering in order to find methods for identifying flight mechanical characteristics. Here, some challenging aeronautical identification problems, estimating model parameters from flight-testing, are treated.

    Two aspects are considered. The first is online identification during flight-testing with the intent to aid the engineers in the analysis process when looking at the flight mechanical characteristics. This will also ensure that enough information is available in the resulting test data for post-flight analysis. Here, a frequency domain method is used. An existing method has been developed further by including an Instrumental Variable approach to take care of noisy data including atmospheric turbulence and by a sensor-fusion step to handle varying excitation during an experiment. The method treats linear systems that can be both stable and unstable working under feedback control. An experiment has been performed on a radio-controlled demonstrator aircraft. For this, multisine input signals have been designed and the results show that it is possible to perform more time-efficient flight-testing compared with standard input signals.

    The other aspect is post-flight identification of nonlinear characteristics. Here the properties of a parameterized observer approach, using a prediction-error method, are investigated. This approach is compared with four other methods for some test cases. It is shown that this parameterized observer approach is the most robust one with respect to noise disturbances and initial offsets. Another attractive property is that no user parameters have to be tuned by the engineers in order to get the best performance.

    All methods in this thesis have been validated on simulated data where the system is known, and have also been tested on real flight test data. Both of the investigated approaches show promising results.

  • Gassner, Gregor J
    et al.
    Mathematisches Institut, Universität zu Köln, Köln, Germany.
    Winters, Andrew R
    Mathematisches Institut, Universität zu Köln, Köln, Germany.
    Kopriva, David A
    Department of Mathematics, The Florida State University, Tallahassee, US.
    Split form nodal discontinuous Galerkin schemes with summation-by-parts property for the compressible Euler equations2016In: Journal of Computational Physics, ISSN 0021-9991, Vol. 327, p. 39-66Article in journal (Refereed)
    Abstract [en]

    Fisher and Carpenter (High-order entropy stable finite difference schemes for non-linear conservation laws: Finite domains, Journal of Computational Physics, 252:518–557, 2013) found a remarkable equivalence of general diagonal norm high-order summation-by- parts operators to a subcell based high-order finite volume formulation. This equivalence enables the construction of provably entropy stable schemes by a specific choice of the sub-cell finite volume flux. We show that besides the construction of entropy stable high order schemes, a careful choice of subcell finite volume fluxes generates split formulations of quadratic or cubic terms. Thus, by changing the subcell finite volume flux to a specific choice, we are able to generate, in a systematic way, all common split forms of the compressible Euler advection terms, such as the Ducros splitting and the Kennedy and Gruber splitting. Although these split forms are not entropy stable, we present a systematic way to prove which of those split forms are at least kinetic energy preserving. With this, we show we construct a unified high-order split form DG framework. We investigate with three dimensional numerical simulations of the inviscid Taylor-Green vortex and show that the new split forms enhance the robustness of high order simulations in comparison to the standard scheme when solving turbulent vortex dominated flows. In fact, we show that for certain test cases, the novel split form discontinuous Galerkin schemes are more robust than the discontinuous Galerkin scheme with over-integration.

  • Winters, Andrew R.
    et al.
    Mathematical Institute, University of Cologne, Cologne, Germany.
    Gassner, Gregor J.
    Mathematical Institute, University of Cologne, Cologne, Germany.
    An entropy stable finite volume scheme for the equations of shallow water magnetohydrodynamics2016In: Journal of Scientific Computing, ISSN 0885-7474, Vol. 67, no 2, p. 514-539Article in journal (Refereed)
    Abstract [en]

    In this work, we design an entropy stable, finite volume approximation for the shallow water magnetohydrodynamics (SWMHD) equations. The method is novel as we design an affordable analytical expression of the numerical interface flux function that exactly preserves the entropy, which is also the total energy for the SWMHD equations. To guarantee the discrete conservation of entropy requires a special treatment of a consistent source term for the SWMHD equations. With the goal of solving problems that may develop shocks, we determine a dissipation term to guarantee entropy stability for the numerical scheme. Numerical tests are performed to demonstrate the theoretical findings of entropy conservation and robustness.

  • Schmidtmann, Birte
    et al.
    MathCCES, RWTH Aachen University, Aachen, Germany.
    Winters, Andrew R.
    Mathematisches Institut, Universität zu Köln, Köln, Germany.
    Hybrid entropy stable HLL-type Riemann solvers for hyperbolic conservation laws2017In: Journal of Computational Physics, ISSN 0021-9991, Vol. 330, p. 566-570Article in journal (Refereed)
    Abstract [en]

    It is known that HLL-type schemes are more dissipative than schemes based on characteristic decompositions. However, HLL-type methods offer greater flexibility to large systems of hyperbolic conservation laws because the eigenstructure of the flux Jacobian is not needed. We demonstrate in the present work that several HLL-type Riemann solvers are provably entropy stable. Further, we provide convex combinations of standard dissipation terms to create hybrid HLL-type methods that have less dissipation while retaining entropy stability. The decrease in dissipation is demonstrated for the ideal MHD equations with a numerical example.

  • Friedrich, Lucas
    et al.
    Mathematical Institute, University of Cologne, Cologne, Germany.
    Fernández, David C Del Rey
    Institute for Aerospace Studies, University of Toronto, Toronto, Canada.
    Winters, Andrew R.
    Mathematical Institute, University of Cologne, Cologne, Germany.
    Gassner, Gregor J
    Mathematical Institute, University of Cologne, Cologne, Germany.
    Zingg, David W
    Institute for Aerospace Studies, University of Toronto, Toronto, Canada.
    Hicken, Jason
    Department of Mechanical, Aerospace, and Nuclear Engineering, Rensselaer Polytechnic Institute, Troy, USA.
    Conservative and stable degree preserving SBP operators for non-conforming meshes2018In: Journal of Scientific Computing, ISSN 0885-7474, Vol. 75, no 2, p. 657-686Article in journal (Refereed)
    Abstract [en]

    Non-conforming numerical approximations offer increased flexibility for applications that require high resolution in a localized area of the computational domain or near complex geometries. Two key properties for non-conforming methods to be applicable to real world applications are conservation and energy stability. The summation-by-parts (SBP) property, which certain finite-difference and discontinuous Galerkin methods have, finds success for the numerical approximation of hyperbolic conservation laws, because the proofs of energy stability and conservation can discretely mimic the continuous analysis of partial differential equations. In addition, SBP methods can be developed with high-order accuracy, which is useful for simulations that contain multiple spatial and temporal scales. However, existing non-conforming SBP schemes result in a reduction of the overall degree of the scheme, which leads to a reduction in the order of the solution error. This loss of degree is due to the particular interface coupling through a simultaneous-approximation-term (SAT). We present in this work a novel class of SBP-SAT operators that maintain conservation, energy stability, and have no loss of the degree of the scheme for non-conforming approximations. The new degree preserving discretizations require an ansatz that the norm matrix of the SBP operator is of a degree ≥ 2p, in contrast to, for example, existing finite difference SBP operators, where the norm matrix is 2p − 1 accurate. We demonstrate the fundamental properties of the new scheme with rigorous mathematical analysis as well as numerical verification.

  • Friedrich, Lucas
    et al.
    Mathematical Institute, University of Cologne, Cologne, Germany.
    Winters, Andrew Ross
    Mathematical Institute, University of Cologne, Cologne, Germany.
    Fernández, David C Del Rey
    National Institute of Aerospace and Computational Aero, Sciences Branch, NASA Langley Research Center, Hampton, USA.
    Gassner, Gregor J
    Mathematical Institute, University of Cologne, Cologne, Germany.
    Parsani, Matteo
    King Abdullah University of Science and Technology (KAUST), Computer Electrical and Mathematical Science and Engineering Division (CEMSE), Extreme Computing Research Center (ECRC), Thuwal, Saudi Arabia.
    Carpenter, Mark H
    Computational Aero, Sciences Branch, NASA Langley Research Center, Hampton, USANASA Langley Research Center.
    An Entropy Stable h/p Non-Conforming Discontinuous Galerkin Method with the Summation-by-Parts Property2018In: Journal of Scientific Computing, ISSN 0885-7474, E-ISSN 1573-7691, Vol. 77, no 2, p. 689-725Article in journal (Refereed)
    Abstract [en]

    This work presents an entropy stable discontinuous Galerkin (DG) spectral element approximation for systems of non-linear conservation laws with general geometric (h) and polynomial order (p) non-conforming rectangular meshes. The crux of the proofs presented is that the nodal DG method is constructed with the collocated Legendre–Gauss–Lobatto nodes. This choice ensures that the derivative/mass matrix pair is a summation-by-parts (SBP) operator such that entropy stability proofs from the continuous analysis are discretely mimicked. Special attention is given to the coupling between non-conforming elements as we demonstrate that the standard mortar approach for DG methods does not guarantee entropy stability for non-linear problems, which can lead to instabilities. As such, we describe a precise procedure and modify the mortar method to guarantee entropy stability for general non-linear hyperbolic systems on h / p non-conforming meshes. We verify the high-order accuracy and the entropy conservation/stability of fully non-conforming approximation with numerical examples.

  • Winters, Andrew Ross
    et al.
    Mathematisches Institut, Universität zu Köln, Köln, Germany.
    Derigs, Dominik
    I. Physikalisches Institut, Universität zu Köln, Köln, Germany.
    Gassner, Gregor J
    Mathematisches Institut, Universität zu Köln, Köln, Germany.
    Walch, Stefanie
    I. Physikalisches Institut, Universität zu Köln, Köln, Germany.
    A uniquely defined entropy stable matrix dissipation operator for high Mach number ideal MHD and compressible Euler simulations2017In: Journal of Computational Physics, ISSN 0021-9991, E-ISSN 1090-2716, Vol. 332, p. 274-289Article in journal (Refereed)
    Abstract [en]

    We describe a unique averaging procedure to design an entropy stable dissipation operator for the ideal magnetohydrodynamic (MHD) and compressible Euler equations. Often in the derivation of an entropy conservative numerical flux function much care is taken in the design and averaging of the entropy conservative numerical flux. We demonstrate in this work that if the discrete dissipation operator is not carefully chosen as well it can have deleterious effects on the numerical approximation. This is particularly true for very strong shocks or high Mach number flows present, for example, in astrophysical simulations. We present the underlying technique of how to construct a unique averaging technique for the discrete dissipation operator. We also demonstrate numerically the increased robustness of the approximation.

  • Bohm, Marvin
    et al.
    Mathematisches Institut, Universität zu Köln, Köln, Germany.
    Winters, Andrew Ross
    Mathematisches Institut, Universität zu Köln, Köln, Germany.
    Gassner, Gregor J
    Mathematisches Institut, Universität zu Köln, Köln, Germany.
    Derigs, Dominik
    I. Physikalisches Institut, Universität zu Köln, Köln, Germany.
    Hindenlang, Florian
    Max-Planck Institut für Plasmaphysik, Garching, Germany.
    Saur, Joachim
    Institut für Geophysik und Meteorologie, Universität zu Köln, Köln, Germany.
    An entropy stable nodal discontinuous Galerkin method for the resistive MHD equations. Part I: Theory and numerical verification2018In: Journal of Computational Physics, ISSN 0021-9991, E-ISSN 1090-2716Article in journal (Refereed)
    Abstract [en]

    The first paper of this series presents a discretely entropy stable discontinuous Galerkin (DG) method for the resistive magnetohydrodynamics (MHD) equations on three-dimensional curvilinear unstructured hexahedral meshes. Compared to other fluid dynamics systems such as the shallow water equations or the compressible Navier-Stokes equations, the resistive MHD equations need special considerations because of the divergence-free constraint on the magnetic field. For instance, it is well known that for the symmetrization of the ideal MHD system as well as the continuous entropy analysis a non-conservative term proportional to the divergence of the magnetic field, typically referred to as the Powell term, must be included. As a consequence, the mimicry of the continuous entropy analysis in the discrete sense demands a suitable DG approximation of the non-conservative terms in addition to the ideal MHD terms.

    This paper focuses on the resistive MHD equations: Our first contribution is a proof that the resistive terms are symmetric and positive-definite when formulated in entropy space as gradients of the entropy variables, which enables us to show that the entropy inequality holds for the resistive MHD equations. This continuous analysis is the key for our DG discretization and guides the path for the construction of an approximation that discretely mimics the entropy inequality, typically termed entropy stability. Our second contribution is a detailed derivation and analysis of the discretization on three-dimensional curvilinear meshes. The discrete analysis relies on the summation-by-parts property, which is satisfied by the DG spectral element method (DGSEM) with Legendre-Gauss-Lobatto (LGL) nodes. Although the divergence-free constraint is included in the non-conservative terms, the resulting method has no particular treatment of the magnetic field divergence errors, which might pollute the solution quality. Our final contribution is the extension of the standard resistive MHD equations and our DG approximation with a divergence cleaning mechanism that is based on a generalized Lagrange multiplier (GLM).

    As a conclusion to the first part of this series, we provide detailed numerical validations of our DGSEM method that underline our theoretical derivations. In addition, we show a numerical example where the entropy stable DGSEM demonstrates increased robustness compared to the standard DGSEM.

  • Derigs, Dominik
    et al.
    I. Physikalisches Institut, Universität zu Köln, Köln, Germany.
    Gassner, Gregor J
    Mathematisches Institut, Universität zu Köln, Köln, Germany.
    Walch, Stefanie
    I. Physikalisches Institut, Universität zu Köln, Köln, Germany.
    Winters, Andrew Ross
    Mathematisches Institut, Universität zu Köln, Köln, Germany.
    Entropy Stable Finite Volume Approximations for Ideal Magnetohydrodynamics2018In: Jahresbericht der Deutschen Mathematiker-Vereinigung (Teubner), ISSN 0012-0456, E-ISSN 1869-7135, Vol. 120, no 3, p. 153-219Article in journal (Refereed)
    Abstract [en]

    This article serves as a summary outlining the mathematical entropy analysis of the ideal magnetohydrodynamic (MHD) equations. We select the ideal MHD equations as they are particularly useful for mathematically modeling a wide variety of magnetized fluids. In order to be self-contained we first motivate the physical properties of a magnetic fluid and how it should behave under the laws of thermodynamics. Next, we introduce a mathematical model built from hyperbolic partial differential equations (PDEs) that translate physical laws into mathematical equations. After an overview of the continuous analysis, we thoroughly describe the derivation of a numerical approximation of the ideal MHD system that remains consistent to the continuous thermodynamic principles. The derivation of the method and the theorems contained within serve as the bulk of the review article. We demonstrate that the derived numerical approximation retains the correct entropic properties of the continuous model and show its applicability to a variety of standard numerical test cases for MHD schemes. We close with our conclusions and a brief discussion on future work in the area of entropy consistent numerical methods and the modeling of plasmas.

  • Derigs, Dominik
    et al.
    I. Physikalisches Institut, Universität zu Köln, Köln, Germany.
    Winters, Andrew Ross
    Mathematisches Institut, Universität zu Köln, Köln, Germany.
    Gassner, Gregor J
    Mathematisches Institut, Universität zu Köln, Köln, Germany.
    Walch, Stefanie
    I. Physikalisches Institut, Universität zu Köln, Köln, Germany.
    A novel averaging technique for discrete entropy-stable dissipation operators for ideal MHD2017In: Journal of Computational Physics, ISSN 0021-9991, E-ISSN 1090-2716, Vol. 330, p. 624-632Article in journal (Refereed)
    Abstract [en]

    Entropy stable schemes can be constructed with a specific choice of the numerical flux function. First, an entropy conserving flux is constructed. Secondly, an entropy stable dissipation term is added to this flux to guarantee dissipation of the discrete entropy. Present works in the field of entropy stable numerical schemes are concerned with thorough derivations of entropy conservative fluxes for ideal MHD. However, as we show in this work, if the dissipation operator is not constructed in a very specific way, it cannot lead to a generally stable numerical scheme. The two main findings presented in this paper are that the entropy conserving flux of Ismail & Roe can easily break down for certain initial conditions commonly found in astrophysical simulations, and that special care must be taken in the derivation of a discrete dissipation matrix for an entropy stable numerical scheme to be robust. We present a convenient novel averaging procedure to evaluate the entropy Jacobians of the ideal MHD and the compressible Euler equations that yields a discretization with favorable robustness properties.

  • Gassner, Gregor J
    et al.
    Mathematical Institute, University of Cologne, Germany.
    Winters, Andrew Ross
    Mathematical Institute, University of Cologne, Germany.
    Kopriva, David A
    Department of Mathematics, The Florida State University Weyertal, Cologne Germany, USA.
    A well balanced and entropy conservative discontinuous Galerkin spectral element method for the shallow water equations2016In: Applied Mathematics and Computation, ISSN 0096-3003, E-ISSN 1873-5649, Vol. 272, no 2, p. 291-308Article in journal (Refereed)
    Abstract [en]

    In this work, we design an arbitrary high order accurate nodal discontinuous Galerkin spectral element type method for the one dimensional shallow water equations. The novel method uses a skew-symmetric formulation of the continuous problem. We prove that this discretisation exactly preserves the local mass and momentum. Furthermore, we show that combined with a special numerical interface flux function, the method exactly preserves the entropy, which is also the total energy for the shallow water equations. Finally, we prove that the surface fluxes, the skew-symmetric volume integrals, and the source term are well balanced. Numerical tests are performed to demonstrate the theoretical findings.

  • Winters, Andrew Ross
    et al.
    Mathematisches Institut, Universität zu Köln, Köln, Germany.
    Gassner, Gregor J.
    Mathematisches Institut, Universität zu Köln, Köln, Germany.
    Affordable, entropy conserving and entropy stable flux functions for the ideal MHD equations2016In: Journal of Computational Physics, ISSN 0021-9991, E-ISSN 1090-2716, Vol. 304, p. 72-108Article in journal (Refereed)
    Abstract [en]

    In this work, we design an entropy stable, finite volume approximation for the ideal magnetohydrodynamics (MHD) equations. The method is novel as we design an affordable analytical expression of the numerical interface flux function that discretely preserves the entropy of the system. To guarantee the discrete conservation of entropy requires the addition of a particular source term to the ideal MHD system. Exact entropy conserving schemes cannot dissipate energy at shocks, thus to compute accurate solutions to problems that may develop shocks, we determine a dissipation term to guarantee entropy stability for the numerical scheme. Numerical tests are performed to demonstrate the theoretical findings of entropy conservation and robustness.

  • Kopriva, David A
    et al.
    Department of Mathematics, The Florida State University, Tallahassee, USA.
    Winters, Andrew Ross
    Mathematisches Institut, Universität zu Köln, Köln, Germany.
    Bohm, Marvin
    Mathematisches Institut, Universität zu Köln, Köln, Germany.
    Gassner, Gregor J
    Mathematisches Institut, Universität zu Köln, Köln, Germany.
    A provably stable discontinuous Galerkin spectral element approximation for moving hexahedral meshes2016In: Computers & Fluids, ISSN 0045-7930, E-ISSN 1879-0747, Vol. 139, p. 148-160Article in journal (Refereed)
    Abstract [en]

    We design a novel provably stable discontinuous Galerkin spectral element (DGSEM) approximation to solve systems of conservation laws on moving domains. To incorporate the motion of the domain, we use an arbitrary Lagrangian-Eulerian formulation to map the governing equations to a fixed reference domain. The approximation is made stable by a discretization of a skew-symmetric formulation of the problem. We prove that the discrete approximation is stable, conservative and, for constant coefficient problems, maintains the free- stream preservation property. We also provide details on how to add the new skew-symmetric ALE approximation to an existing discontinuous Galerkin spectral element code. Lastly, we provide numerical support of the theoretical results.

  • Derigs, Dominik
    et al.
    I. Physikalisches Institut, Universität zu Köln, Köln, Germany.
    Winters, Andrew Ross
    Mathematisches Institut, Universität zu Köln, Köln, Germany.
    Gassner, Gregor J
    Mathematisches Institut, Universität zu Köln, Köln, Germany.
    Walch, Stefanie
    I. Physikalisches Institut, Universität zu Köln, Köln, Germany.
    A novel high-order, entropy stable, 3D AMR MHD solver with guaranteed positive pressure2016In: Journal of Computational Physics, ISSN 0021-9991, E-ISSN 1090-2716, Vol. 317, p. 223-256Article in journal (Refereed)
    Abstract [en]

    We describe a high-order numerical magnetohydrodynamics (MHD) solver built upon a novel non-linear entropy stable numerical flux function that supports eight travelling wave solutions. By construction the solver conserves mass, momentum, and energy and is entropy stable. The method is designed to treat the divergence-free constraint on the magnetic field in a similar fashion to a hyperbolic divergence cleaning technique. The solver described herein is especially well-suited for flows involving strong discontinuities. Furthermore, we present a new formulation to guarantee positivity of the pressure. We present the underlying theory and implementation of the new solver into the multi-physics, multi-scale adaptive mesh refinement (AMR) simulation code FLASH (http://flash.uchicago.edu). The accuracy, robustness and computational efficiency is demonstrated with a number of tests, including comparisons to available MHD implementations in FLASH.

  • Winters, Andrew Ross
    et al.
    Mathematisches Institut, Universität zu Köln, Köln, Germany.
    Gassner, Gregor J.
    Mathematisches Institut, Universität zu Köln, Köln, Germany.
    A comparison of two entropy stable discontinuous Galerkin spectral element approximations for the shallow water equations with non-constant topography2015In: Journal of Computational Physics, ISSN 0021-9991, E-ISSN 1090-2716, Vol. 301, p. 357-376Article in journal (Refereed)
    Abstract [en]

    In this work, we compare and contrast two provably entropy stable and high-order accurate nodal discontinuous Galerkin spectral element methods applied to the one dimensional shallow water equations for problems with non-constant bottom topography. Of particular importance for numerical approximations of the shallow water equations is the well-balanced property. The well-balanced property is an attribute that a numerical approximation can preserve a steady-state solution of constant water height in the presence of a bottom topography. Numerical tests are performed to explore similarities and differences in the two high-order schemes.

  • Winters, Andrew Ross
    et al.
    Department of Mathematics, The Florida State University, Tallahassee, USA.
    Kopriva, David A.
    Department of Mathematics, The Florida State University, Tallahassee, USA.
    High-order local time stepping on moving DG spectral element meshes2014In: Journal of Scientific Computing, ISSN 0885-7474, E-ISSN 1573-7691, Vol. 58, no 1, p. 176-202Article in journal (Refereed)
    Abstract [en]

    We derive and evaluate an explicit local time stepping (LTS) integration for the discontinuous Galerkin spectral element method (DGSEM) on moving meshes. The LTS procedure is derived from Adams-Bashforth multirate time integration methods. We also present speedup and memory estimates, which show that the explicit LTS integration scales well with problem size. Time-step refinement studies with static and moving meshes show that the approximations are spectrally accurate in space and have design temporal accuracy. The numerical tests validate theoretical estimates that the LTS procedure can reduce computational cost by as much as an order of magnitude for time accurate problems.

  • Ingvarsson, Sanne
    Linköping University, Department of Computer and Information Science.
    Using Machine Learning to Learn from Bug Reports: Towards Improved Testing Efficiency2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The evolution of a software system originates from its changes, whether it comes from changed user needs or adaption to its current environment. These changes are as encouraged as they are inevitable, although every change to a software system comes with a risk of introducing an error or a bug. This thesis aimed to investigate the possibilities of using the description of bug reports as a decision basis for detecting the provenance of a bug by using machine learning. K-means and agglomerative clustering have been applied to free text documents by using Natural Language Processing to initially divide the investigated software system into sub parts. Topic labelling is further on performed on the found clusters to find suitable names and get an overall understanding for the clusters.Finally, it was investigated if it was possible to find which cluster that were more likely to cause a bug from certain clusters and should be tested more thoroughly. By evaluating a subset of known causes, it was found that possible direct connections could be found in 50% of the cases, while this number increased to 58% if the cause were attached to clusters. 

  • Public defence: 2019-05-29 13:15 Planck, Linköping
    Smeds, Magdalena
    Linköping University, Department of Management and Engineering, Logistics & Quality Management. Linköping University, Faculty of Science & Engineering.
    Managing care pathways for patients with complex care needs2019Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    One of the central challenges for the healthcare system today is how to manage care for patients with complex needs. This patient group is not well-defined but covers patients with serious diseases and comorbidities, or with a limited ability to perform basic daily functions due to physical, mental or psychosocial challenges. This group has a high service and resource utilisation resulting in high costs for the healthcare system and, typically, poor health outcomes. To improve care for these patients, it is necessary to implement strategies to manage the differentiated care needs, the additional support needs, the uncertainty in care delivery, and the coordination needs of the involved providers and the patient.

    Care pathways are increasingly used internationally to make care more patient-centred and to structure and design care processes for individual patient groups. Important elements in care pathways include structuring care activities, by defining their content and sequence; coordinating between providers and professionals; and involving patients in their care process. In this thesis, care pathways are proposed as the overall strategy for managing care for patients with complex care needs.

    The purpose of this thesis is thus to contribute with knowledge on how care pathways can be managed for patients with complex care needs. This is achieved by analysing how the practices coordination, standardisation, customisation and personalisation can support management of care pathways and by discussing how these practices influence quality of care. The quality of care dimensions discussed are accessible, timely, equitable, and patient-centred care.

    The empirical context in this thesis is the Standardised Cancer Care Pathways (CCPs) which were implemented in Sweden from 2015 to 2018. CCPs is the umbrella term for the national initiative to shorten waiting times, decrease regional differences and reduce fragmentation in care processes. CCPs include elements such as diagnosis-specific pathways and guidelines, introduction of CPP coordinators, and mandatory reporting of waiting times. Focus has been on implementing care pathways for 31 cancer diagnoses in all Swedish healthcare regions.

    Both qualitative and quantitative research methods have been used. A case study was conducted to examine standardised and customised care pathways, and coordination and multidisciplinary work in care pathways. A document study of regional reports on CCPs was analysed to study effects of care pathways on accessibility, timeliness and equitability. Finally, a national survey was conducted to deepen the understanding of the role of coordination, as performed by coordinators, in care pathways.

    This thesis argues that standardised and customised care pathways should be combined to manage care for patients with complex care needs. The customised pathway in particular benefits patients with serious unspecific symptoms, unknown primary tumour or more complex care needs, while patients with care needs that can be treated independently of the main diagnosis benefit from following a standardised care pathway.

    Coordinators are an important means to manage coordination, customisation and personalisation in the care pathway. The coordinators’ role is twofold: the first role is to manage care pathways by customising the care pathway and coordinating involved providers; the second role is to support and guide patients through the care pathway. This can be achieved by adapting interpersonal communication with patients through personalisation.

    This thesis further argues that care pathways have most potential to positively influence accessibility, timeliness, equitability, and patient-centredness. Accessibility has been positively influenced, especially for patients with ambiguous symptoms where symptoms indicating cancer have improved their chances of accessing cancer diagnostics. A negative aspect of prioritising patients who follow CCPs has been the potentially longer waiting times for other patient groups in equal need of urgent care. Notwithstanding, prioritised access to care is perceived to positively influence timeliness for patients following CCPs. Care pathways are perceived to have positively influenced patient-centredness by shifting the focus from what to deliver to how to deliver it.

    List of papers
    1. The management of cancer care pathways in a coordination centre
    Open this publication in new window or tab >>The management of cancer care pathways in a coordination centre
    2018 (English)Conference paper, Published paper (Refereed)
    Abstract [en]

    PurposeCoordination, patient centeredness and accessibility of care are important aspects for patients with complex care needs. Variations in symptoms, morbidity, care needs, and individual prerequisites are large within these patient groups which complicates diagnostics and treatment. New ways of organising health care is needed to handle these challenges and the use of solutions as multidisciplinary cancer centres and coordination centres are becoming more common.The purpose of this paper is to study how health care can be organised to care for patients with complex care needs. This is done by describing how one coordination centre works with management and coordination of care pathways in cancer care.

    Design/methodology/approachThis paper is based on a qualitative single case study where the implementation of CCPs was studied in the Region of Östergötland. Three main data collection methods were used: semi-structured interviews, observations and document studies. Sixteen interviews were held with three physicians, seven nurses, two care unit managers, two general practitioners and the coordination centres two project leaders. Ten observational studies in the form of participative and non-participative observations in meetings were conducted. A retrospective document study was also conducted where internal public documents were systematically reviewed. Pilot study reports and implementation reports, during the period 2014 to 2018 were read and analysed by conducting content analysis.

    FindingsThe UCCD was designed to take care of all potential cancer patients under ‘one roof’. This implied the need to find routines for handling a large amount of patients, with several different cancer diagnoses, and widely diverse care needs. The organisational design resulted in two diagnostic pathways: a standardised and a customised. The standardised diagnostic pathway works well for patients with clear symptoms and care needs with low complexity where the care can be standardised to follow rules and guidelines. The customised diagnostic pathway works well for patients with ambiguous symptoms care needs with high complexity where the care pathway need to be tailored and diagnostics are done by problem solving based on intuition and experience.

    Originality/Value of paperThis paper contributes with knowledge on how coordination centres can work with care pathways to improve health care coordination and quality for patients with complex care needs.

    Keywords
    Health care, cancer care pathways, coordination centre, patient centeredness, standardisation
    National Category
    Reliability and Maintenance
    Identifiers
    urn:nbn:se:liu:diva-155094 (URN)
    Conference
    21st QMOD conference, Cardiff UK, 22-24 August, 2018
    Available from: 2019-03-18 Created: 2019-03-18 Last updated: 2019-05-14
    2. The effects of cancer care pathways on waiting times
    Open this publication in new window or tab >>The effects of cancer care pathways on waiting times
    2018 (English)In: International Journal of Quality and Service Sciences, ISSN 1756-669X, E-ISSN 1756-6703Article in journal (Refereed) Epub ahead of print
    Abstract [en]

    Purpose

    The Swedish health-care system currently implements cancer care pathways (CCPs) for better and more timely cancer diagnostics. The purpose of this paper is to elucidate and define “crowding out” effects associated with the CCP implementation.

    Design/methodology/approach

    A document study based on implementation reports and action plans from Swedish county councils (n = 21) and a case study in one county council were conducted. Qualitative data collection and analysis were used to acquire more knowledge about the “crowding out” effects associated with the CCP implementation.

    Findings

    Three effects discussed under “crowding out” were defined. The first effect, called the push-out effect, occurs when other patients have to wait for care longer in favour of CCP patients. Another effect is the inclusion effect, whereby “crowding out” is reduced for vulnerable patients due to the standardised procedures and criteria in the referral process. The final effect is the exclusion effect, where patients in need of cancer diagnostics are, for some reason, not referred to CCP. These patients are either not diagnosed at all or diagnosed outside CCP by a non-standard process, with the risk of longer waiting times.

    Originality/value

    “Crowding out” effects are an urgent topic related to CCP implementation. While these effects have been reported in international research studies, no shared definition has been established to describe them. The present paper creates a common base to measure the “crowding out” effects and support further development of CCPs to avoid the negative effects on waiting times.

    Place, publisher, year, edition, pages
    Emerald Group Publishing Limited, 2018
    Keywords
    Health care, Standardisation, Patient care, Quality management, Health care management, Quality of health care
    National Category
    Reliability and Maintenance Health Care Service and Management, Health Policy and Services and Health Economy
    Identifiers
    urn:nbn:se:liu:diva-154049 (URN)10.1108/IJQSS-04-2018-0041 (DOI)2-s2.0-85058658565 (Scopus ID)
    Available from: 2019-01-24 Created: 2019-01-24 Last updated: 2019-05-14Bibliographically approved
  • Gambino, Davide
    Linköping University, Department of Physics, Chemistry and Biology, Theoretical Physics. Linköping University, Faculty of Science & Engineering.
    Structural and magnetic disorder in crystalline materials: a first principles study2019Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Disorder in crystalline materials can take different forms and originate from different sources. In particular, temperature introduces disorder in any kind of material. This can be observed as the appearance of vacant lattice sites in an otherwise perfect crystal, or as a random distribution of different elements on the same lattice in an alloy; at the same time, if the material is magnetic, temperature induces disorder also on the magnetic degrees of freedom. In this thesis, different levels of disorder associated to structure and magnetism are investigated by means of density functional theory and thermodynamic models.

    I start with diffusion of Ti vacancies in TiN, which is studied by means of nonequilibrium ab initio molecular dynamics using the color diffusion algorithm at different temperatures. The result is an Arrhenius behavior of Ti vacancy jump rates.

    A method to perform structural relaxations in magnetic materials in their hightemperature paramagnetic phase is then developed based on the disordered local moments approach in order to study vacancies, interstitial atoms, and combinations of defects in paramagnetic bcc Fe and B1 CrN, as well as the mixing enthalpy of bcc Fe1−xCrx random alloys. A correction to the energetics of every system due to the relaxation in the disordered magnetic state is observed in all cases.

    Not related to temperature and disorder, but very important for an accurate description of magnetic materials, is the choice of the exchange and correlation functional to be employed in the first principles calculations. We have investigated the performance of a recently developed meta-GGA functional, the strongly constrained and appropriately normed (SCAN) functional, in comparison with the more commonly used LDA and PBE on the ferromagnetic elemental solids bcc Fe, fcc Ni, and hcp Co, and SCAN it is found to give negligible improvements, if not a worsening, in the description of these materials.

    Finally, the coupling between vibrational and magnetic degrees of freedom is discussed by reviewing the literature and proposing an investigation of the influence of vibrations on longitudinal spin fluctuations. These excitations are here studied by means of thermodynamic models based on Landau expansion of the energy in even powers of the magnitude of the local magnetic moments. We find that vibrational and magnetic disorder alter the energy landscapes as a function of moment size also in bcc Fe, which is often considered a Heisenberg system, inducing a more itinerant electron behavior.

    List of papers
    1. Nonequilibrium ab initio molecular dynamics determination of Ti monovacancy migration rates in B1 TiN
    Open this publication in new window or tab >>Nonequilibrium ab initio molecular dynamics determination of Ti monovacancy migration rates in B1 TiN
    2017 (English)In: Physical Review B, ISSN 2469-9950, E-ISSN 2469-9969, Vol. 96, no 10, article id 104306Article in journal (Refereed) Published
    Abstract [en]

    We use the color diffusion (CD) algorithm in nonequilibrium (accelerated) ab initio molecular dynamics simulations to determine Ti monovacancy jump frequencies in NaCl-structure titanium nitride (TiN), at temperatures ranging from 2200 to 3000 K. Our results showthat theCDmethod extended beyond the linear-fitting rate-versus-force regime [Sangiovanni et al., Phys. Rev. B 93, 094305 (2016)] can efficiently determine metal vacancy migration rates in TiN, despite the low mobilities of lattice defects in this type of ceramic compound. We propose a computational method based on gamma-distribution statistics, which provides unambiguous definition of nonequilibrium and equilibrium (extrapolated) vacancy jump rates with corresponding statistical uncertainties. The acceleration-factor achieved in our implementation of nonequilibrium molecular dynamics increases dramatically for decreasing temperatures from 500 for T close to the melting point T-m, up to 33 000 for T approximate to 0.7 T-m

    Place, publisher, year, edition, pages
    AMER PHYSICAL SOC, 2017
    National Category
    Condensed Matter Physics
    Identifiers
    urn:nbn:se:liu:diva-141712 (URN)10.1103/PhysRevB.96.104306 (DOI)000411076000005 ()
    Note

    Funding Agencies|Swedish Foundation for Strategic Research (SSF) project SRL [10-0026]; Swedish Research Council (VR) [621-2011-4417, 2015-04391, 330-2014-6336]; Swedish Government Strategic Research Area Grant in Materials Science on Advanced Functional Materials [MatLiU 2009-00971]; Ministry of Education and Science of the Russian Federation [14.Y26.31.0005]; Marie Sklodowska Curie Actions [INCA 600398]; Swedish Foundation for Strategic Research; Stiftelsen Olle Engkvist Byggmastare

    Available from: 2017-10-05 Created: 2017-10-05 Last updated: 2019-05-14
    2. Lattice relaxations in disordered Fe-based materials in the paramagnetic state from first principles
    Open this publication in new window or tab >>Lattice relaxations in disordered Fe-based materials in the paramagnetic state from first principles
    2018 (English)In: Physical Review B, ISSN 2469-9950, E-ISSN 2469-9969, Vol. 98, no 6, article id 064105Article in journal (Refereed) Published
    Abstract [en]

    The first-principles calculation of many material properties, in particular related to defects and disorder, starts with the relaxation of the atomic positions of the system under investigation. This procedure is routine for nonmagnetic and magnetically ordered materials. However, when it comes to magnetically disordered systems, in particular the paramagnetic phase of magnetic materials, it is not clear how the relaxation procedure should be performed or which geometry should be used. Here we propose a method for the structural relaxation of magnetic materials in the paramagnetic regime, in an adiabatic fast-magnetism approximation within the disordered local moment (DLM) picture in the framework of density functional theory. The method is straightforward to implement using any ab initio code that allows for structural relaxations. We illustrate the importance of considering the disordered magnetic state during lattice relaxations by calculating formation energies and geometries for an Fe vacancy and C insterstitial atom in body-centered cubic (bcc) Fe as well as bcc Fe1-xCrx random alloys in the paramagnetic state. In the vacancy case, the nearest neighbors to the vacancy relax toward the vacancy of 0.14 angstrom (-5% of the ideal bcc nearest-neighbor distance), which is twice as large as the relaxation in the ferromagnetic case. The vacancy formation energy calculated in the DLM state on these positions is 1.60 eV, which corresponds to a reduction of about 0.1 eV compared to the formation energy calculated using DLM but on ferromagnetic-relaxed positions. The carbon interstitial formation energy is found to be 0.41 eV when the DLM relaxed positions are used, as compared to 0.59 eV when the FM-relaxed positions are employed. For bcc Fe0.5Cr0.5 alloys, the mixing enthalpy is reduced by 5 meV/atom, or about 10%, when the DLM state relaxation is considered, as compared to positions relaxed in the ferromagnetic state.

    Place, publisher, year, edition, pages
    AMER PHYSICAL SOC, 2018
    National Category
    Condensed Matter Physics
    Identifiers
    urn:nbn:se:liu:diva-151199 (URN)10.1103/PhysRevB.98.064105 (DOI)000443139600004 ()
    Note

    Funding Agencies|Swedish Research Council (VR) [2014-6336]; Marie Sklodowska Curie Actions, Cofund [INCA 600398]; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University (Faculty Grant SFOMatLiU) [2009 00971]; Swedish Foundation for Strategic Research

    Available from: 2018-09-13 Created: 2018-09-13 Last updated: 2019-05-14
    3. Assessing the SCAN functional for itinerant electron ferromagnets
    Open this publication in new window or tab >>Assessing the SCAN functional for itinerant electron ferromagnets
    Show others...
    2018 (English)In: Physical Review B, ISSN 2469-9950, E-ISSN 2469-9969, Vol. 98, no 9, article id 094413Article in journal (Refereed) Published
    Abstract [en]

    Density functional theory is a standard model for condensed-matter theory and computational material science. The accuracy of density functional theory is limited by the accuracy of the employed approximation to the exchange-correlation functional. Recently, the so-called strongly constrained appropriately normed (SCAN) [Sun, Ruzsinszky, and Perdew, Phys. Rev. Lett. 115, 036402 (2015)] functional has received a lot of attention due to promising results for covalent, metallic, ionic, as well as hydrogen- and van der Waals-bonded systems alike. In this work, we focus on assessing the performance of the SCAN functional for itinerant magnets by calculating basic structural and magnetic properties of the transition metals Fe, Co, and Ni. We find that although structural properties of bcc-Fe seem to be in good agreement with experiment, SCAN performs worse than standard local and semilocal functionals for fcc-Ni and hcp-Co. In all three cases, the magnetic moment is significantly overestimated by SCAN, and the 3d states are shifted to lower energies, as compared to experiments.

    Place, publisher, year, edition, pages
    AMER PHYSICAL SOC, 2018
    National Category
    Theoretical Chemistry
    Identifiers
    urn:nbn:se:liu:diva-151640 (URN)10.1103/PhysRevB.98.094413 (DOI)000444348500004 ()
    Note

    Funding Agencies|Swedish e-Science Research Centre (SeRC); Swedish Research Council (VR) through the International Career Grant [20146336]; Marie Sklodowska CurieActions, Cofund, Project [INCA 600398]; Swedish Foundation for Strategic Research (SSF) through the Future Research Leaders 6 program; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University (Faculty Grant SFO-Mat-LiU) [2009-00971]; competence center FunMat-II - Vinnova [201605156]; Russian Science Foundation [18-12-00492]

    Available from: 2018-09-27 Created: 2018-09-27 Last updated: 2019-05-14
  • Public defence: 2019-06-14 13:15 ACAS, A building, Linköping
    Pantic-Dragisic, Svjetlana
    Linköping University, Department of Management and Engineering, Business Administration. Linköping University, Faculty of Arts and Sciences.
    The interplay between organizational capabilities and individual skills: Studies of technical and engineering consulting firms2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The number of professional service firms has increased rapidly in the recent decades. This thesis focuses on a type of professional service firm that has, thus far, been under-researched, namely the technical and engineering consulting (TEC) firm. TEC firms are important actors with regard to innovation, knowledge development, and the transfer of knowledge among problemsolving contexts. This thesis addresses the organization and development of engineering knowledge and the roles of the TEC firm and the technical consultants in the transfer of knowledge among assignments, projects, client organizations, and industries.

    This thesis consists of a compilation of four papers and an extended summary. It builds on four qualitative studies and takes a multilevel perspective by utilizing an embedded case-study design to examine both the organizational level and the individual level as well as the interaction between the two levels. The thesis draws upon interviews with managers, consultants, client representatives, and industry experts and analysts. Moreover, it presents findings from an in-depth study of a competence development program for technical consultants.

    This thesis contributes to the professional service firm literature by uncovering the knowledgebased advantages accrued by TEC firms through the organization and development of engineering knowledge. This thesis identifies two capabilities, swift transition and knowledge cycling, and argues that the link between these capabilities creates the foundation for the successful organization of engineering knowledge. The thesis demonstrates that the capabilities developed by TEC firms are formed through the interaction between the organizational level and the individual level. In addition, this thesis illustrates that capabilities differ among TEC firms. These differences stem from the organizational processes of the firm and the individual skills of the technical consultants. Based on these differences, the thesis identifies two ideal types of firms: resource-capitalizer and project-capitalizer. Furthermore, it develops the notion of knowledge cycling which demonstrates how the mobility inherent in the technical consultants’ work facilitates the transfer and development of knowledge within and among problem-solving contexts. This process highlights the roles of the individual consultant, the TEC firm, and the client organization in the transfer of knowledge within and among assignments, projects, client organizations, and industries. Finally, this thesis provides insight into how formal training can develop the consultants’ ability to transfer knowledge among problem-solving contexts by enhancing their liminality competence.

    List of papers
    1. On the move to stay current: Knowledge cycling and scheduled labor mobility
    Open this publication in new window or tab >>On the move to stay current: Knowledge cycling and scheduled labor mobility
    2018 (English)In: Management Learning, ISSN 1350-5076, E-ISSN 1461-7307, Vol. 49, no 4, p. 429-452Article in journal (Refereed) Published
    Abstract [en]

    Technical consulting plays an increasingly important role in developing and transferring knowledge in a wide range of industries and sectors. We present a case study of Swift Tech, a leading Scandinavian technical consulting firm, to identify and assess the importance of knowledge cyclinga knowledge process based on scheduled and recurrent rotation of technical consultants among organizational and problem-solving contexts. Our study identifies four main phases of knowledge cycling: entering an assignment, building experience, contributing to the project, and shifting to a new assignment. These phases underpin our model of knowledge cycling, which demonstrates that two aspects of local knowledge processes are critical: project task familiarization and project organization familiarization. We show that knowledge cycling relies on a dynamic interaction between client organization, consulting firm, and individual consultant in the ongoing transfer of knowledge among distinct contexts and communities. Knowledge cycling demonstrates the significance of mobile knowledge for the development of situated knowledge; hence, our results have important implications for situated learning theory.

    Place, publisher, year, edition, pages
    SAGE PUBLICATIONS LTD, 2018
    Keywords
    Knowledge cycling; knowledge transfer; labor mobility; liminality; project-based work; technical consultants
    National Category
    Business Administration
    Identifiers
    urn:nbn:se:liu:diva-151496 (URN)10.1177/1350507618772258 (DOI)000443429800003 ()
    Note

    Funding Agencies|Swedish Research Council; Jan Wallanders and Tom Hedelius foundation

    Available from: 2018-09-24 Created: 2018-09-24 Last updated: 2019-05-14
    2. Creating the mobile engineer: a study of a training program for engineering consultants
    Open this publication in new window or tab >>Creating the mobile engineer: a study of a training program for engineering consultants
    2018 (English)In: European Journal of Training and Development, ISSN 2046-9012, E-ISSN 2046-9020, European Journal of Training and Development, ISSN 2046-9012, Vol. 42, no 7/8, p. 381-399Article in journal (Refereed) Published
    Abstract [en]

    Purpose

    The purpose of this paper is to explore how a technical consulting firm approaches the development of engineering consultants, to prepare them to deal with their liminal, i.e. mobile and transient work situation. More specifically, this paper addresses how a training program, designed for newly graduated engineers, can increase the consultants’ liminality competence.

    Design/methodology/approach

    This paper reports on a qualitative case study of an introductory development program in a Scandinavian technical consulting firm. The study is based on observations of training sessions and meetings, and interviews with developers, leaders and participants of the program.

    Findings

    This study identifies three processes, which develop the engineering consultants’ ability to master their mobile and transient work situation: identifying the core of an assignment, embracing “in-betweenness” and broadening the scope of action.

    Originality/value

    This paper enhances the understanding of formal training in the context of technical consulting and adds to the knowledge of how engineering consultants can master their liminal work positions; in particular, the study identifies how liminality competence can be elevated through formal training.

    Place, publisher, year, edition, pages
    Emerald Group Publishing Limited, 2018
    Keywords
    Knowledge transfer, Liminality, Engineering consultants, Formal training, Liminality competence, Mobile engineers
    National Category
    Economics and Business Business Administration Work Sciences Learning
    Identifiers
    urn:nbn:se:liu:diva-156832 (URN)10.1108/EJTD-12-2017-0117 (DOI)000448530200002 ()2-s2.0-85053274684 (Scopus ID)
    Available from: 2019-05-14 Created: 2019-05-14 Last updated: 2019-05-21Bibliographically approved
  • Public defence: 2019-06-04 13:15 BL32, B-huset, Linköping
    Banda, Adson
    Linköping University, Department of Mathematics, Mathematics and Applied Mathematics. Linköping University, Faculty of Science & Engineering.
    Coherent functors and asymptotic properties2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    In this thesis we study properties of the so called coherent functors. Coherent functors were first introduced by Auslander in 1966 in a general setting. Coherent functors have been used since then as powerful tools for different purposes: to describe infinitesimal deformation theory, to describe algebraicity of a stack or to study properties of Rees algebras.

    In 1998, Hartshorne proved that half exact coherent functors over a discrete valuation ring 𝐴 are direct sums of the identity functor, Hom-functors of quotient modules of 𝐴 and tensor products of quotient modules of 𝐴𝐴. In our first article (Paper A), we obtain a similar characterization for half exact coherent functors over a much wider class of rings: Dedekind domains. This fact allows us to classify half exact coherent functors over Dedekind domains.

    In our second article (Paper B), coherent functors over noetherian rings are considered. We study asymptotic properties of sets of prime ideals connected with coherent functors applied to artinian modules or finitely generated modules. Also considering quotient modules M /anM, where 𝑎𝑎𝑛𝑛 is the nthpower of an ideal 𝑎𝑎, one obtains that the Betti and Bass numbers of the images under a coherent functor of the quotient modules above are polynomials in n for large n. Furthermore, the lengths of these image modules are polynomial in 𝑛𝑛, for large 𝑛𝑛, under the condition that the image modules have finite length.

    List of papers
    1. Half–Exact Coherent Functors over PIDs and Dedekind Domains
    Open this publication in new window or tab >>Half–Exact Coherent Functors over PIDs and Dedekind Domains
    2016 (English)Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    The focus of this thesis is to characterize half–exact coherent functors over principal ideal domains (PIDs) and Dedekind domains. Ever since they where discovered, coherent functors have been useful in the study of some mathematical objects. We aim to explore a little more about them in this thesis.

    We first give here a review of the general categorical notions relevant to the characterization. We also review the functors Ext(M,−) and Tor(M,−)  on the category on A–modules, where A is a commutative ring and M is an A–module.

    With the assumption that A is a commutative noetherian ring, we introduce coherent functors defined on the category of finitely generated A–modules. It is then shown in the paper that any half–exact coherent functor over a PID, and more generally over a Dedekind domain, arises from a complex of projective modules.

    Place, publisher, year, edition, pages
    Linköping: Linköping University Electronic Press, 2016. p. 40
    Series
    Linköping Studies in Science and Technology. Thesis, ISSN 0280-7971 ; 1752
    National Category
    Mathematics
    Identifiers
    urn:nbn:se:liu:diva-128616 (URN)978-91-7685-750-2 (ISBN)
    Presentation
    2016-06-08, Nobel (BL32), B-huset, Campus Valla, Linköping, 15:15 (English)
    Opponent
    Supervisors
    Note

    The thesis serie title Linköping Studies in Science and Technology. Licentiate Thesis is incorrect. The correct title is Linköping Studies in Science and Technology. Thesis.

    Available from: 2016-05-25 Created: 2016-05-25 Last updated: 2019-05-13Bibliographically approved
    2. Coherent functors and asymptotic stability
    Open this publication in new window or tab >>Coherent functors and asymptotic stability
    2019 (English)In: Journal of Algebra, ISSN 0021-8693, E-ISSN 1090-266X, Vol. 522Article in journal (Refereed) Published
    Abstract [en]

    Asymptotic properties of high powers of an ideal related to a coherent functor F are investigated. It is shown that when N is an artinian module the sets of attached prime ideals Att(A) F(0 :(N) a(n)) are the same for n large enough. Also it is shown that for an artinian module N if the modules F(0 :(N) a(n)) have finite length and for a finitely generated module M if the modules F(M/a(n) M) have finite length, their lengths are given by polynomials in n, for large n. When A is local it is shown that, the Betti numbers beta(i)(F(M /a(n) M)) and the Bass numbers mu(i)(F(M / a(n) M)) are given by polynomials in n for large n. (C) 2018 Elsevier Inc. All rights reserved.

    Place, publisher, year, edition, pages
    ACADEMIC PRESS INC ELSEVIER SCIENCE, 2019
    Keywords
    Asymptotic prime ideal; Coherent functor; Hilbert polynomial; Betti number; Bass number
    National Category
    Algebra and Logic
    Identifiers
    urn:nbn:se:liu:diva-154529 (URN)10.1016/j.jalgebra.2018.11.035 (DOI)000457509500001 ()
    Note

    Funding Agencies|ISP through EAUMP

    Available from: 2019-02-20 Created: 2019-02-20 Last updated: 2019-05-13
  • Köhler, Helena
    et al.
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences.
    Trygg, Kristina
    Linköping University, Department of Thematic Studies, Technology and Social Change. Linköping University, Faculty of Arts and Sciences.
    A time-geographical mixed-methods approach: studying the complexities of energy and water use in households2019In: Fennia, ISSN 0015-0010, Vol. 197, no 1, p. 108-120Article in journal (Refereed)
    Abstract [en]

    The objective of this study is to describe and assess a methodology based on a time geographical approach for studying energy and water use in households. Energy and water resources are often used in routinized activities, and in activities considered as private, normal and ordinary, which makes them difficult to explore in research. In this article, we give an account of a mixed-methods approach using time diaries, metering data, interviews and simple observations, and analyse and discuss its methodological and empirical implications from two Swedish case studies. We conclude that the suggested combination of methods, despite some complications, provides a comprehensive account of household energy and water use to which various theoretical perspectives could apply. Energy and water using activities are defined in terms of time, place, quantity, material and social context, and are related to user perspectives on resource use and usage data. Such knowledge provides important input for information campaigns, technological retrofitting and other systemic changes in striving towards sustainability.

  • Public defence: 2019-06-04 13:00 Belladonna, Linköping
    Levin, Sara
    Linköping University, Department of Medical and Health Sciences, Division of Community Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    The challenges of using structured risk assessment instruments in forensic psychiatric care2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Background: The purpose of psychiatric forensic care is to provide treatment for mentally ill offenders and to prevent future acts of violence and other adverse events. During care, the type of restrictions of freedom, the patient’s continuous need for involuntary treatment and readiness for discharge, are continuously evaluated based on the assessment of risk the patient pose to themselves and others as well as the progress achieved with treatment. The use of structured risk assessment instruments is recommended in clinical guidelines to assess such risks. However, unstructured clinical assessments, considered to be less valid, are often used in clinical practice. There is insufficient research evidence concerning several aspects related to the clinical use of structured risk assessment instruments in terms of guiding the planning and realization of care and risk management interventions. There is also a lack of knowledge about what patients themselves perceive to be mediating factors for their use of violence. Overall aim: The overarching aim of this thesis was to investigate the implementation and use of structured risk assessment instruments to prevent violence and other adverse events in forensic settings and to improve understanding of the factors that influence such events among forensic patients.

    Methods: Several methods were used for data collection and data were analysed by different types of content analysis. In the first paper, a systematic review of previous research studies on implementation determinants for structured risk assessment instruments in forensic settings was conducted to investigate implementation determinants for such instruments. The second paper evaluates a pilot project of the implementation of a structured risk assessment instrument at a forensic clinic in Östergötland using focus group interviews with staff members who had used the instrument. Their perceptions of the instrument and barriers and facilitators to its implementation and clinical use were investigated. The third paper investigated the actual clinical use of structured risk assessments to guide the planning and realization of care and risk management interventions documented in forensic patients’ records. In the fourth paper, patient perspectives of factors increasing and decreasing the risk for violence were investigated by individual semi-structured interviews with forensic patients.

    Results: There is a wide variety of determinants for the implementation and clinical use of structured risk assessment instruments, which make such missions complicated. The determinants relate to the characteristics of the implementation object, characteristics of users, the inner setting in which the implementation occurs and the implementation process. Limiting the need to change current routines, and hence the strain on the organization by reducing complexity, and the need for resource allocation seem especially important. Most of the planned risk management interventions in structured risk assessments were realized according to patient records. However, structured risk assessments largely overlap with unstructured risk assessments in terms of planned care and risk management interventions. Noteworthy, most of the interventions realized were not documented as planned. Forensic patients described several risk factors that increased and decreased their use of violence. These factors related to themselves, external influences, social and relational aspects and situational factors. Most patient accounts of mediating factors overlapped with those listed in commonly used risk assessment instruments and previous research. Additional factors identified by patients related to the outer context and interpersonal aspects.

    Conclusions: There are many barriers and facilitators to the implementation and use of structured risk assessment instruments, implying the need for a multifaceted approach to address determinants at several system levels. Considering the clinical context is important when selecting a structured risk assessment instrument to be implemented, but also the complexity of the instrument, the required change of routines and the provision of continuous resources and interventions to achieve and maintain clinical use. Despite the many barriers, there is evidence of clinical use of both unstructured clinical and structured risk assessments in terms of informing and guiding care and risk management interventions. The large overlap, however, makes it difficult to draw definite conclusion about which type of assessment actually influenced the interventions that were realized. Realized care and risk management interventions are most often not documented as planned. This increases the risk of subjective decisions and provision of interventions, which also make such interventions difficult to evaluate. Forensic patients are actively managing their risk of violence and are capable of identifying and communicating many different mediating factors for their violence risk. They are knowledgeable and important stakeholders and should be involved in their own risk assessments, as well as in research.

    List of papers
    1. Structured Risk Assessment Instruments: A Systematic Review of Implementation Determinants
    Open this publication in new window or tab >>Structured Risk Assessment Instruments: A Systematic Review of Implementation Determinants
    2016 (English)In: Psychiatry, Psychology and Law, ISSN 1321-8719, E-ISSN 1934-1687, Vol. 23, no 4, p. 602-628Article in journal (Refereed) Published
    Abstract [en]

    Research-based structured risk assessment instruments (SRAIs) can improve violence risk assessment and clinical judgements in mental health and correctional services. Practical challenges of implementing SRAIs have led to calls for more research to understand the determinants influencing this process. Studies describing determinants for SRAI implementation in psychiatric, correctional, or community in-patient settings were systematically reviewed. Findings were analysed according to the Consolidated Framework for Implementation Research. A total of 11 studies were included. Four types of main implementation determinants were found: characteristics of the SRAI; users of the SRAI; inner setting; and process. Findings underscore the importance of applying a multifactorial approach to the implementation of SRAIs to address many different barriers and facilitators. More stringent research is needed to obtain more solid evidence of factors that impede or enable SRAI implementation, especially regarding patient perspectives and outer setting determinants. Constructing shared concepts of determinants across research fields could further aid information transferences.

    Place, publisher, year, edition, pages
    Routledge, 2016
    Keywords
    determinants; implementation; structured risk assessment; systematic review; violence
    National Category
    Pediatrics
    Identifiers
    urn:nbn:se:liu:diva-131922 (URN)10.1080/13218719.2015.1084661 (DOI)000383249100010 ()
    Available from: 2016-10-13 Created: 2016-10-11 Last updated: 2019-05-13
    2. Staff Perceptions of Facilitators and Barriers to the Use of a Short- Term Risk Assessment Instrument in Forensic Psychiatry
    Open this publication in new window or tab >>Staff Perceptions of Facilitators and Barriers to the Use of a Short- Term Risk Assessment Instrument in Forensic Psychiatry
    2018 (English)In: Journal of Forensic Psychology Research and Practice, ISSN 2473-2850, Vol. 18, no 3, p. 199-228Article in journal (Refereed) Published
    Abstract [en]

    Prospective adverse events within forensic settings should be assessed using structured risk assessment instruments. Our aim was to identify the barriers and facilitators of a structured instrument for assessment of short-term risk within inpatient forensic psychiatric care. The instrument was piloted at a forensic psychiatric clinic. Three focus group interviews were conducted with staff. Content analysis revealed three main categories of barriers and facilitators for clinical use: implementation object, context, and users. Complexity of the instrument, insufficient continuous training and support, difficulties retrieving assessments on wards, and insecurity about translating assessments into actions were perceived barriers to clinical use. Routines for documentation improved communication and the inclusion of protective and short-term dynamic clinical factors were perceived as clinically relevant. Problem-solving ability, attitude, and motivation of staff were facilitating factors. Comprehensive risk assessment instruments require substantial support for staff to find them manageable. Systematic documentation is required to measure actual daily clinical use.

    Place, publisher, year, edition, pages
    Routledge, 2018
    Keywords
    tructured risk assessment;START; implementation;clinical use of researchevidence
    National Category
    Psychiatry
    Identifiers
    urn:nbn:se:liu:diva-154051 (URN)10.1080/24732850.2018.1466260 (DOI)000452643000001 ()
    Available from: 2019-01-24 Created: 2019-01-24 Last updated: 2019-05-13
    3. Adherence to planned risk management interventions in Swedish forensic care: What is said and done according to patient records
    Open this publication in new window or tab >>Adherence to planned risk management interventions in Swedish forensic care: What is said and done according to patient records
    2019 (English)In: International Journal of Law and Psychiatry, ISSN 0160-2527, E-ISSN 1873-6386, Vol. 64, p. 71-82Article in journal (Refereed) Published
    Abstract [en]

    Both structured and unstructured clinical risk assessments within forensic care aim to prevent violence by informing risk management, but research about their preventive role is inconclusive. The aim of this study was to investigate risk management interventions that were planned and realized during forensic care by analysing patient records. Records from a forensic clinic in Sweden, covering 14 patients and 526 months, were reviewed. Eight main types of risk management interventions were evaluated by content analysis: monitoring, supervision, assessment, treatment, victim protection, acute coercion, security level and police interventions. Most planned risk management interventions were realized, both in structured and clinical risk assessments. However, most realized interventions were not planned, making them more open to subjective decisions. Analysing risk management interventions actually planned and realized in clinical settings can reveal the preventive role of structured risk assessments and how different interventions mediate violence risk.

    Place, publisher, year, edition, pages
    Elsevier, 2019
    Keywords
    Risk assessment, Risk management, Forensic care, Violence risk
    National Category
    Forensic Science
    Identifiers
    urn:nbn:se:liu:diva-156724 (URN)10.1016/j.ijlp.2019.02.003 (DOI)2-s2.0-85062027323 (Scopus ID)
    Available from: 2019-05-13 Created: 2019-05-13 Last updated: 2019-05-21Bibliographically approved
  • Ahlstrand, Alexander
    et al.
    Linköping University, Department of Behavioural Sciences and Learning, Education, Teaching and Learning. Linköping University, Faculty of Educational Sciences.
    Ivarsson, Erik
    Linköping University, Department of Behavioural Sciences and Learning, Education, Teaching and Learning. Linköping University, Faculty of Educational Sciences.
    Lärares högläsning som undervisningsform: Undervisningsstrategier som främjar elevers språkutveckling2019Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Högläsning kan ses som ett verktyg för att utveckla elevers språk och har samtidigt visat sig vara betydelsefull för elevers egen läsutveckling. Att lärare högläser för elever är därför av största vikt. Syftet med denna studie är att undersöka vilka strategier forskare förespråkar att lärare kan använda sig av under högläsningen för att främja elevers språk. Syftet är också att undersöka vilka betydelser deförespråkade strategierna kan ha på elevers lärande. Högläsning avser i denna studie den form när läraren läser högt för eleverna. Formen inkluderar även interaktioner mellan lärare och elever likt ett socialkonstruktivistiskt synsätt på lärande där elever lär i samspel med andra. Förståelsen och förmågan att röra sig i andra texter är också viktiga aspekter som utvecklar elevers literacy. I denna studie har vi använt oss av manuella sökningar och sökningar i databasen ERIC. Litteraturstudien är baserad på resultat från elva olika studier. Resultatet visar att de förespråkade strategierna kan delas upp i tre kategorier: 1. Förberedelser innan högläsning. 2. Texters struktur och innehåll. 3. Ordförrådsstrategier. Utifrån studiens resultat rekommenderar vi att lärare med fördel kan tillämpa strategier från respektive resultatdel. Lärare har inför högläsning didaktiska val att ta ställning till, exempelvis strategin bokval. För att främja förståelsen av texters struktur och innehåll kan lärare till exempel utnyttja strategierna berättelsens komponenteroch dramatisera. Slutligen bör lärare använda sig av planerade ordförrådsstrategier där exempelvis ord placeras i ny kontext eller att elever konstruerar nya meningar med ord.  

  • Public defence: 2019-06-05 13:00 Berzeliussalen, Linköping
    Grossmann, Benjamin
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Anaesthetics, Operations and Specialty Surgery Center, Department of Anaesthesiology and Intensive Care in Linköping.
    Procedural sedation: Aspects on methods, safety and effectiveness2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Background: Safety and effectiveness are fundamental principles within the healthcare sector to provide quality of care and health improvement for patients. By ensuring that care is provided based on evidence-based knowledge, risks and complications can be minimised and the use of scarce resources optimised. An increasing demand for diagnostic and therapeutic procedures challenges the traditional methods for sedation regarding safety and effectiveness. It is desirable that the fundamental principles are improved when refining existing or developing new sedation methods. In this doctoral thesis, safety and effectiveness were evaluated for adult patient-controlled sedation (PCS) using propofol during two endoscopic procedures: endoscopic retrograde cholangiopancreaticography (ERCP) and flexible bronchoscopy (FB); and different doses of rectal racemic ketamine for paediatric (< 4 years) burn wound care.

    Methods: Data on vital functions, sedation level, safety interventions, procedure feasibility, patient-reported outcome and experience measures, and recovery, from three clinical randomised controlled trials were collected. Costs of sedation for the endoscopic procedures were compiled in a cost-analysis study.

    Results: PCS with propofol and bedside anaesthetic personnel was shown to be a safe and effective alternative method of sedation during ERCP and FB compared with intravenous sedation with midazolam. The PCS method gives stable cardiorespiratory conditions with few adverse events and interventions, with a low risk of oversedation. PCS offers similar (FB) or better (ERCP) procedure feasibility and patient satisfaction during the procedures than midazolam. Recovery after PCS is quick, minimises the risk for prolonged hospitalisation and is thereby a potential cost-saving sedation method. The optimal dose of rectal racemic ketamine, 6 mg/kg with the addition of 0.5 mg/kg midazolam during severely painful procedures, gives minimal risk for outbreaks of pain, offers stable vital signs conditions and allows rapid recovery without affecting procedure feasibility.

    Conclusions: The sedation method can be adjusted to type of procedure and patient population. PCS with propofol offers an alternative and reliable method for adult sedation during endoscopic procedures, whereas rectal racemic ketamine combined with midazolam provides good conditions for burn care dressing procedures in young children.

    List of papers
    1. Sedation during endoscopic retrograde cholangiopancreatography: A randomised controlled study of patient-controlled propofol sedation and that given by a nurse anaesthetist
    Open this publication in new window or tab >>Sedation during endoscopic retrograde cholangiopancreatography: A randomised controlled study of patient-controlled propofol sedation and that given by a nurse anaesthetist
    Show others...
    2015 (English)In: Scandinavian Journal of Gastroenterology, ISSN 0036-5521, E-ISSN 1502-7708, Vol. 50, no 10, p. 1285-1292Article in journal (Refereed) Published
    Abstract [en]

    Objective: Different regimens are used for sedation during ERCP (endoscopic retrograde cholangiopancreatography). Our objectives were to compare safety, ease of treatment, time to recovery and patients’ experiences using PCS (patient-controlled sedation) with propofol as well as sedation given by a nurse anaesthetist (ACS) with propofol or midazolam during ERCP.

    Material and methods: The study included 281 adults in 301 procedures. The PCS group (n=101) delivered bolus doses of 5 mg of propofol according to their need for sedation. The ACS group (n=100) had 2-8 mg/kg/hour of propofol infused, with the target for sedation being Level 3 of the Observer’s Assessment of Alertness/Sedation scale (OAA/S). The control group was given 2-3 mg of midazolam for induction and additional 1 mg if required.

    Results: PCS and ACS increased the ease of the procedure and reduced the numbers of sedation failures compared to midazolam sedation (ACS n=0; PCS n=4; midazolam n=20). The ACS group had more deeply sedated patients (OAA/S Level 2), desaturations and obstructed airways than the PCS and midazolam groups. Over 90% of all patients had recovered (Aldrete score≥9) by the time they returned to the ward. PCS resulted in the least fatigue and pain after the procedure. Patients’ preference for PCS and ACS were the same.

    Conclusion: PCS with propofol is superior to midazolam and comparable to ACS. PCS resulted in a rapid recovery, tended to be the safest and was almost as effective as ACS in ensuring a successful examination.

    Place, publisher, year, edition, pages
    Taylor & Francis, 2015
    Keywords
    Conscious sedation, propofol, Cholangiopancreatography, Endoscopic Retrograde
    National Category
    Anesthesiology and Intensive Care
    Identifiers
    urn:nbn:se:liu:diva-112371 (URN)10.3109/00365521.2015.1038848 (DOI)000361324600013 ()
    Available from: 2014-11-24 Created: 2014-11-24 Last updated: 2019-05-13Bibliographically approved
    2. Rectal ketamine during paediatric burn wound dressing procedures: a randomised dose-finding study
    Open this publication in new window or tab >>Rectal ketamine during paediatric burn wound dressing procedures: a randomised dose-finding study
    2019 (English)In: Burns, ISSN 0305-4179, E-ISSN 1879-1409Article in journal (Refereed) Epub ahead of print
    Abstract [en]

    Background

    Worldwide, ketamine is used during paediatric procedures, but no recommendations are available regarding a suitable dose for rectal administration during procedures involving high levels of pain and/or anxiety such as burn wound dressing change.

    Methods

    We evaluated three different single doses of rectally administered racemic ketamine mixed with a fixed dose of 0.5 mg/kg of midazolam. In total, 90 children – aged 6 months to 4 years – were randomised 1:1:1 to receive 4 mg/kg (K-4 group), 6 mg/kg (K-6 group) or 8 mg/kg (K-8 group) of racemic ketamine for a maximum of three consecutive procedures. Primary outcome measure was procedural pain evaluated by Face, Legs, Activity, Cry, Consolability (FLACC) behavioural scale. Secondary outcome included feasibility and recovery time. Patient safety was evaluated using surrogate outcomes.

    Results

    In total, 201 procedures in 90 children aged 19 ± 8 months were completed. The median maximum pain was FLACC 0 in all groups (p = 0.141). The feasibility was better for groups K-6 (p = 0.049) and K-8 (p = 0.027) compared with K-4, and the mean recovery time was the longest for group K-8 (36 ± 22 min) compared with groups K-4 (25 ± 15 min; p = 0.003) and K-6 (27 ± 20 min; p = 0.025). Median maximum sedation measured by the University of Michigan Sedation Scale (UMSS) was higher in group K-8 compared with group K-4 (p < 0.0001) and K-6 (p = 0.023). One child in group K-8 had a study drug-related serious adverse event — laryngospasm/airway obstruction. No rescue analgosedative medication was administered for group K-6.

    Conclusions

    A rectally administered mixture of racemic ketamine (6 mg/kg) and midazolam (0.5 mg/kg) during paediatric burn dressing procedures with a duration of approximately 30 min provides optimal conditions regarding pain relief, feasibility, recovery time and patient safety, with no need for rescue analgosedative medication.

    Place, publisher, year, edition, pages
    Pergamon Press, 2019
    National Category
    Anesthesiology and Intensive Care Public Health, Global Health, Social Medicine and Epidemiology Surgery
    Identifiers
    urn:nbn:se:liu:diva-156837 (URN)10.1016/j.burns.2018.12.012 (DOI)31060760 (PubMedID)2-s2.0-85065014700 (Scopus ID)
    Available from: 2019-05-14 Created: 2019-05-14 Last updated: 2019-05-21Bibliographically approved
  • Public defence: 2019-05-29 13:00 Berzeliussalen, Linköping
    Hultkvist, Henrik
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Thoracic and Vascular Surgery.
    Implications of myocardial dysfunction before and after aortic valve intervention2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    BACKGROUND

    Postoperative heart failure in the setting of aortic valve surgery results in poor long-term survival. We hypothesized that there could be a myocardial factor that is not addressed by risk scores currently available. We speculated that this myocardial factor could be diastolic dysfunction. By evaluating postoperative heart failure, the EuroSCORE, the NT-proBNP level, and diastolic function, we might achieve a deeper understanding of the outcome for individuals with postoperative heart failure.

    METHODS

    This research project was built upon four cohort studies. The first two studies (I and II) were retrospective in nature, and studies III and IV were prospective, observational, and longitudinal. All work was based on data from clinical and national databases. In Study I, we compared the outcome of patients with or without postoperative heart failure, evaluated according to the preoperative risk score. In Study II, we explored the effect of underlying heart disease on the preoperative level of NT-proBNP and the relationships between NT-proBNP and severe postoperative heart failure and short-term mortality. In Study III, we described the dynamics

    of NT-proBNP, from a preoperative evaluation to a six-month follow-up, in patients that underwent one of two different procedures: a surgical aortic valve replacement and a transcatheter implantation. We related both pre- and postprocedural NT-proBNP levels to one-year mortality. In Study IV, we evaluated diastolic function in patients that underwent surgical aortic valve replacement and its influence on outcome. We also evaluated NT-proBNP levels and postoperative heart failure as predictors of long-term mortality.

    RESULTS

    Study I

    This study included 397 patients that underwent isolated surgical aortic valve replacements. Of these, 45 patients (11%) were treated for postoperative heart failure. With an average follow-up of 8.1 years (range 5.2-11.2), among patients at low risk (EuroSCORE≤7), the crude five-year survival rates were 58% in patients with postoperative heart failure and 89% in those without postoperative heart failure (p<0.001). Among patients with postoperative heart failure, those classified as low risk had the same poor long-term prognosis as those classified as high risk (EuroSCORE>7). In the high risk group, survival rates were similar between patients with or without postoperative heart failure (57% vs. 64%; p=0.60).

    Study II

    This study included a cohort of 2978 patients with coronary artery disease, aortic stenosis, and mitral regurgitation. Preoperative NTproBNP levels were found to be 1.7-fold higher in patients with aortic stenosis than in patients with coronary artery disease and 1.4-fold higher in patients with mitral regurgitation than in patients with coronary disease. The power of preoperative NT-proBNP for predicting severe postoperative heart conditions was good among patients with coronary heart disease and patients with mitral regurgitation, but not as good among patients with aortic stenosis. NT-proBNP also showed good discriminating power for short-term mortality among patients with coronary artery disease. Moreover, NT-proBNP was found to be an independent predictor for both severe postoperative heart failure and short-term mortality in patients with coronary artery disease.

    Study III

    This study included 462 patients that underwent preoperative evaluations for aortic valve disease. Aortic valve interventions elicited a rise in NT-proBNP that was more pronounced in patients undergoing surgical aortic valve replacement compared to patients undergoing transcatheter valve implantation. No deterioration in NT-proBNP was observed during the waiting time before the intervention, despite a median duration of four months. At six months after the intervention, NT-proBNP levels had decreased to or below the preoperative levels in all groups. Among patients that received surgical aortic valve replacements, pre-and early postoperative NT-proBNP levels showed good discriminatory power for oneyear mortality. This discriminatory power was not observed among patients that had undergone a transcatheter procedure; those patients had higher levels of both pre- and postoperative NT-proBNP compared to patients that had undergone surgery.

    Study IV

    We evaluated 273 patients that underwent aortic valve surgery. High left ventricular filling pressure was present in 22% (n=54) of patients at the time of surgery. At six months after surgery, diastolic function deteriorated in 24/193 (12%) patients and improved in 27/54 (50%) patients. Diastolic dysfunction was not found to be associated with long-term mortality. However, both postoperative heart failure and preoperative NTproBNP levels were associated with increases in long-term mortality. In a multivariable Cox analysis, NT-proBNP remained predictive of long-term mortality.

    CONCLUSION

    Postoperative heart failure contributed to long-term mortality, even in patients considered to be at low risk preoperatively. Our results suggested that pressure overload, followed by a volume overload led to a NTproBNP response that was more pronounced than the ischemia response. Elevated levels of NT-proBNP were associated with both short- and long-term mortality. In these studies, we could not corroborate the notion that high left ventricular filling pressure was associated with long-term mortality.

    List of papers
    1. The combined impact of postoperative heart failure and euroScore on long-term outcome after surgery for aortic stenosis
    Open this publication in new window or tab >>The combined impact of postoperative heart failure and euroScore on long-term outcome after surgery for aortic stenosis
    2011 (English)In: Journal of Heart Valve Disease, ISSN 0966-8519, E-ISSN 2053-2644, Vol. 20, no 6, p. 633-638Article in journal (Refereed) Published
    Abstract [en]

    BACKGROUND AND AIM OF THE STUDY:

    Although the EuroSCORE was developed for predicting operative mortality after cardiac surgery, it has also been shown to predict long-term mortality. It has been reported that postoperative heart failure (PHF) in association with surgery, albeit comparatively benign in the short term, has a profound impact on five-year survival after surgery for aortic stenosis (AS). The study aim was to determine the combined impact of EuroSCORE and PHF on long-term survival after isolated aortic valve replacement (AVR) for AS.

    METHODS:

    A total of 397 patients (48% females; average age 70 +/- 10 years) who underwent AVR for AS at the authors' institution between 1995 and 2000 was studied. The cohort was subdivided according to the additive EuroSCORE into a high-risk group (EuroSCORE >7) and a low-risk group (EuroSCORE < or = 7), and further analyzed in relation to PHF.

    RESULTS:

    The average follow up was 8.1 years (range: 5.2-11.2 years). Forty-five patients (11%) were treated for procedure-associated PHF. Patients with or without PHF and a high-risk EuroSCORE had crude five-year survivals of 57% and 64%, respectively (p = 0.6), whereas those with or without PHF but with a low-risk EuroSCORE had crude five-year survivals of 58% and 89%, respectively (p = 0.0003).

    CONCLUSION:

    Both PHF and a high EuroSCORE were associated with poor long-term survival. The role of PHF per se for the long-term prognosis was illustrated by the fact that the negative impact on long-term survival was almost as profound in patients of the low-risk group as of the high-risk group.

    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-73431 (URN)000306675200005 ()22655493 (PubMedID)
    Available from: 2012-01-03 Created: 2012-01-03 Last updated: 2019-05-13Bibliographically approved
    2. Impact of underlying heart disease per se on the utility of preoperative NT-proBNP in adult cardiac surgery
    Open this publication in new window or tab >>Impact of underlying heart disease per se on the utility of preoperative NT-proBNP in adult cardiac surgery
    Show others...
    2018 (English)In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 13, no 2, article id e0192503Article in journal (Refereed) Published
    Abstract [en]

    Objective The primary aim was to investigate the role of underlying heart disease on preoperative NT-proBNP levels in patients admitted for adult cardiac surgery, after adjusting for the known confounders age, gender, obesity and renal function. The second aim was to investigate the predictive value of preoperative NT-proBNP with regard to severe postoperative heart failure (SPHF) and postoperative mortality. Methods A retrospective cohort study based on preoperative NT-proBNP measurements in an unselected cohort including all patients undergoing first time surgery for coronary artery disease (CAD; n = 2226), aortic stenosis (AS; n = 406) or mitral regurgitation (MR; n = 346) from April 2010 to August 2016 in the southeast region of Sweden (n = 2978). Concomitant procedures were not included, with the exception of Maze or tricuspid valve procedures. Results Preoperative NT-proBNP was 1.67 times (pamp;lt;0.0001) and 1.41 times (pamp;lt;0.0001) higher in patients with AS or MR respectively, than in patients with CAD after adjusting for confounders. NT-proBNP demonstrated significant discrimination with regard to SPHF in CAD (AUC = 0.79, 95% CI 0.73 +/- 0.85, pamp;lt;0.0001), MR (AUC = 0.80, 95% CI 0.72 +/- 0.87, pamp;lt;0.0001) and AS (AUC = 0.66, 95% CI 0.51 +/- 0.81, p = 0.047). In CAD patients NT-proBNP demonstrated significant discrimination with regard to postoperative 30-day or in-hospital mortality (AUC = 0.78; 95% CI 0.71 +/- 0.85, pamp;lt;0.0001). The number of deaths was too few in the AS and MR group to permit analysis. Elevated NT-proBNP emerged as an independent risk factor for SPHF, and postoperative mortality in CAD. Conclusions Patients with AS or MR have higher preoperative NT-proBNP than CAD patients even after adjusting for confounders. The predictive value of NT-proBNP with regard to SPHF was confirmed in CAD and MR patients but was less convincing in AS patients.

    Place, publisher, year, edition, pages
    PUBLIC LIBRARY SCIENCE, 2018
    National Category
    Cardiac and Cardiovascular Systems
    Identifiers
    urn:nbn:se:liu:diva-145771 (URN)10.1371/journal.pone.0192503 (DOI)000424517900085 ()29420603 (PubMedID)
    Note

    Funding Agencies|Region Ostergotland [LIO-443891]

    Available from: 2018-03-22 Created: 2018-03-22 Last updated: 2019-05-13
    3. Rise and fall of NT-proBNP in aortic valve intervention.
    Open this publication in new window or tab >>Rise and fall of NT-proBNP in aortic valve intervention.
    2018 (English)In: Open heart, E-ISSN 2053-3624, Vol. 5, no 1, article id e000739Article in journal (Refereed) Published
    Abstract [en]

    Objectives: To describe the dynamics of N-terminal pro-B-type natriuretic peptide (NT-proBNP) from preoperative evaluation to 6-month follow-up in patients undergoing aortic valve intervention, and to evaluate NT-proBNP with regard to 1-year mortality.

    Methods: At preoperative evaluation, we prospectively included 462 patients accepted for aortic valve intervention. The median time to surgical aortic valve replacement (SAVR; n=336) or transcatheter aortic valve implantation (TAVI; n=126) was 4 months. NT-proBNP was measured at enrolment for preoperative evaluation, on the day of surgery, postoperatively on day 1, day 3 and at the 6-month follow-up. Subgroups of patients undergoing SAVR with aortic regurgitation and aortic stenosis with and without coronary artery bypass were also analysed.

    Results: NT-proBNP remained stable in all subgroups during the preoperative waiting period, but displayed a substantial transient early postoperative increase with a peak on day 3 except in the TAVI group, which peaked on day 1. At the 6-month follow-up, NT-proBNP had decreased to or below the preoperative level in all groups. In the SAVR group, NT-proBNP preoperatively and on postoperative days 1 and 3 revealed significant discriminatory power with regard to 1-year mortality (area under the curve (AUC)=0.79, P=0.0001; AUC=0.71, P=0.03; and AUC=0.79, P=0.002, respectively). This was not found in the TAVI group, which had higher levels of NT-proBNP both preoperatively and at the 6-month follow-up compared with the SAVR group.

    Conclusions: The dynamic profile of NT-proBNP differed between patients undergoing TAVI and SAVR. NT-proBNP in the perioperative course was associated with increased risk of 1-year mortality in SAVR but not in TAVI.

    Keywords
    aortic valve disease, heart failure, surgery-valve
    National Category
    Cardiac and Cardiovascular Systems
    Identifiers
    urn:nbn:se:liu:diva-149013 (URN)10.1136/openhrt-2017-000739 (DOI)29632678 (PubMedID)
    Available from: 2018-06-25 Created: 2018-06-25 Last updated: 2019-05-13
  • Reidarman, Karin
    Linköping University, Department of Science and Technology, Media and Information Technology. Linköping University, Faculty of Science & Engineering.
    Exoplanets: Interactive Visualization of Data and Discovery Method2018Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This report provides a description of the development and implementation of an Exoplanet visualization within the interactive astro-visualization software OpenSpace. Orbital Data from The Exoplanet Orbit Database were used to render the planetary systems around stars known to have exoplanets in orbit. The uncertainties of the data in the database were incorporated into the design of the visualization. A feature that visualizes the discovery method of exoplanets was also implemented.

  • Anany, Hossam
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Effectiveness of a speed advisory traffic signal system for Conventional and Automated vehicles in a smart city2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This thesis project presents a traffic micro simulation study that investigates the state-of-the-art in traffic management "Green Light Optimal Speed Advisory (GLOSA)" for vehicles in a smart city. GLOSA utilizes infrastructure and vehicles communication through using current signal plan settings and updated vehicular information in order to influence the intersection approach speeds. The project involves simulations for a mixed traffic environment of conventional and automated vehicles both connected to the intersection control and guided by a speed advisory traffic management system. Among the project goals is to assess the effects on traffic performance when human drivers comply to the speed advice. The GLOSA management approach is also accessed for its potential to improve traffic efficiency in a full market penetration of connected automated vehicles with enhanced capabilities such as having shorter time head ways.

  • Al-Sader, Mohamed
    Linköping University, Department of Science and Technology, Media and Information Technology. Linköping University, Faculty of Science & Engineering.
    Gaze-driven interaction in video games2018Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The introduction of input devices with natural user interfaces in gaming hardware has changed the way we interact with games. Hardware with motion-sensing and gesture recognizing capabilities remove the constraint of interacting with games through typical traditional devices like mouse-keyboard and gamepads. This changes the way we approach games and how the game communicates back to us as the player opening new levels of interactivity. This thesis covers how eye tracker technology can be used to affect rendering effects in games.

  • Larsson-Berge, Sofia
    Linköping University, Department of Computer and Information Science.
    Planera Mera: The perceived gaming experience of the application Planera Mera with adolescents with mild intellectual disability2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The purpose of this study is to examine the users’ experience of the game Planera Mera and what parts of the game that increases or decreasestheir gaming experience for adolescents with mild intellectual disability. 15 adolescents in the age of 16 to 20 years with mild intellectual disability from special needs upper secondary schoolparticipated in a user study on the applicationPlanera Merafor thisstudy.

    The results show that the perceived gaming experience increases when the users clearly understand how to solve the tasks, when the tasks are correctly executed and when the tasks are easy to solve properly and decreases when it is hard to understand the task, when the tasks given are to complex or when the tasks are not solved correctly. This is supported by the result that there is a correlation between the number of participants who completed each task and the average grade each task got from the participants. This suggests that the user might benefit from help in the game in the form of hints of how close the user is to a correct answer and the gaming experience might increase. This is also supported by the principle that people with mild intellectual disability benefits in their learning by physical and verbal prompting to guide correct responses (Browder & Spooner, 2005).