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  • Bae, Cheolyong
    et al.
    Linköpings universitet, Institutionen för systemteknik, Datorteknik.
    Gokhale, Madhur
    Linköpings universitet, Institutionen för systemteknik, Datorteknik.
    Implementation of High-Speed 512-Tap FIR Filters for Chromatic Dispersion Compensation2018Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    A digital filter is a system or a device that modifies a signal. This is an essential feature in digital communication. Using optical fibers in the communication has various advantages like higher bandwidth and distance capability over copper wires. However, at high-rate transmission, chromatic dispersion arises as a problem to be relieved in an optical communication system. Therefore, it is necessary to have a filter that compensates chromatic dispersion. In this thesis, we introduce the implementation of a new architecture of the filter and compare it with a previously proposed architecture.

  • Erhard-Olsson, Niklas
    Linköpings universitet, Institutionen för datavetenskap, Interaktiva och kognitiva system.
    Procedural Generation of 2D Levels for a Motion-based Platformer Game in Unity with Large Amount of Movement2018Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    This thesis mainly describes and implements a new way of analyzing motion generated when playing a motion controlled game. It also describes the implementation of automatic level generation together with the utilization of Unitys excellent new 2D tools. The motion controller used to play the prototype game is ported and implemented with Unitys own shader language and stored as a reusable prefab for any Unity project. A new specific method of analyzing the motion mapped to the level is implemented in Unity. Some game specific analysises is presented with the said method, and examples of how the method can be used for more and richer analysis’s is discussed.

  • Fur, Filip
    Linköpings universitet, Institutionen för datavetenskap.
    The Improvement of Automating the Guest OS Configuration of Virtual Machines Deployed from Templates: A Case Study2018Independent thesis Basic level (university diploma), 10 poäng / 15 hpOppgave
    Abstract [en]

    This paper investigates the effects of automating system administration within a virtualized server environment. For system administrators, creation and configuration of new Virtual Machines has shown to be a common, and yet time and manual labour consuming task. Thus, this process has been studied thoroughly to find out in what degree it will lend itself to automation. The nature of the process was found to be well-suited for a high degree of automation. The automation tool is developed, presented and evaluated. A series of quantitative tests were orchestrated, testing both manual configuration and configuration by using the tool. The results were analysed, and it became visible that the manual configuration has an interruptive behaviour which is not the case in the produced process. The time improvements of the automation are approximated from the gathered test data and the results show a significant improvement in process speed-up with a test average of 300% corresponding to roughly 22 minutes per configured VM. Note that when calculating time saving and process speed-up the assumption is made that two employees are depending on the configuration which has been seen often to be the case.

    This work has shed light on the need for a more holistic estimation model of calculating process speed-up when you have factors as multiple people being dependent on a process and added time due to loss of operator focus (e.g. due to interruptive behaviour during the process). Furthermore, a strong case is made for the implementation of process automation in administrat ive tasks within virtualized server environments.

  • Joensuu, Jenny
    Linköpings universitet, Institutionen för fysik, kemi och biologi. Linköpings universitet, Tekniska fakulteten.
    Online Image Analysis of Jurkat T Cells using in situ Microscopy2015Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Cell cultivation in bioreactors would benefit from developed monitoring systems with online real-time imaging to evaluate cell culture conditions and processes. This opportunity can be provided with the newly developed in situ Microscope also called ISM. The ISM probe is mounted into the wall of a bioreactor and consists of a measurement zone with an illuminating light source to obtain real-time images of moving cells in suspension. The instrument is linked to advanced imaging analysis software which can be specifically adapted for the objects in study. The aim of this project is to analyze the T lymphocyte cell line Jurkat T cells using the ISM equipment and identify specific features of the cells that can be obtained. The results show that the equipment and linked software are suitable for monitoring cell density, cell size distribution and cell surface analysis of the Jurkat cells during cultivation. The ISM could also detect induced changes in cell size caused by osmotic shifts and the course of an infection occurring in the cell suspension using a developed software for online real-time monitoring.

  • Disputas: 2019-01-18 13:15 K3, Kåkenhus, Norrköping
    Dahlberg, Joen
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Kommunikations- och transportsystem. Linköpings universitet, Tekniska fakulteten.
    Cost allocation methods in cooperative transportation planning2018Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Transportation, together with transportation planning for goods, provides good conditions for economic growth and is a natural part of modern society. However, transportation has negative side effects, including emissions and traffic congestion. A freight forwarder may consolidate shippers’ goods in order to reduce some of the negative side effects, thus reducing emissions and/or congestion as well as operational costs. The negative side effects as well as operational costs can be further reduced if a number of freight forwarders cooperate and consolidate their collective goods flows. Consolidation refers to the process of merging a number of the freight forwarders’ shipments of goods into a single shipment. In this case, the freight forwarders are cooperating with competitors (the other freight forwarders).

    Fair cost allocations are important for establishing and maintaining cost-efficient cooperation among competing stakeholders. Cooperative game theory defines a number of criteria for fair cost allocations and the problem associated with the decision process for allocating costs is referred to as the cost allocation problem. In this thesis, cooperative game theory is used as an academic tool to study cooperation among stakeholders in two transportation planning applications, namely 1) the distribution of goods bound for urban areas and 2) the transportation of wood between harvest areas and industries.

    In transportation planning application 1, there is a cooperation among a number of freight forwarders and a municipality. Freight forwarders’ goods bound for an urban area are consolidated at a facility located just outside the urban area. In this thesis, operational costs for distributing the goods are assessed by solving vehicle routing problems. Common methods from cooperative game theory are used for allocating the operational costs among the freight forwarders and the municipality. In transportation planning application 2, forest companies cooperate in terms of the supply and transportation of common resources, or more specifically, different types of wood. Each forest company has harvest areas and industries to which the wood is transported. The resources may be bartered, that is, the forest companies may transport wood from each other’s harvest areas.

    In the cooperative game theory literature, the stakeholders are often treated equally in the context of transportation planning. However, there seems to be a lack of studies on cooperations where at least one stakeholder differs from the other stakeholders in some fundamental way, for instance, as an initiator or an enabler of the cooperation. Such cooperations are considered in this thesis. The municipality and one of the forest companies are considered to be the initiators in their respective applications.

    Five papers are appended to this thesis and the overall aim is to contribute to the research into cooperative transportation planning by using concepts from cooperative game theory to develop methods for allocating costs among cooperating stakeholders. The purpose of this thesis is to provide decision support for planners in the decisionmaking process of transportation planning to establish cost-efficient and stable cooperations.

    Some of the main outcomes of this thesis are viable and practical methods that could be used in real-life situations to allocate costs among cooperating stakeholders, as well as support for decisionmakers who are concerned with transportation planning. This is done by demonstrating the potential of cooperation, such as cost reduction, and by suggesting how costs can be allocated fairly in the transportation planning applications considered. Lastly, a contribution to cooperative game theory is provided; the introduction of a development of the equal profit method for allocating costs. The proposed version is the equal profit method with lexicography, which, in contrast to the former, guarantees to yield at most one solution to any cost allocation problem. Lexicography is used to rank potential cost allocations and the unambiguously best cost allocation is chosen.  

    Delarbeid
    1. Consolidation in Urban Freight Transportation - Cost Allocation Models
    Åpne denne publikasjonen i ny fane eller vindu >>Consolidation in Urban Freight Transportation - Cost Allocation Models
    2018 (engelsk)Inngår i: Asia-Pacific journal of operational research, ISSN 0217-5959, E-ISSN 1793-7019, Vol. 35, nr 4, artikkel-id 1850023Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    In this paper, the focus is on the role of the municipality, as an enabler of a collaboration between freight forwarders and the municipality in which the consolidation of goods is considered as a means for goods flow improvement in urban freight transportation. We present a cost allocation model that is based on solution concepts from cooperative game theory, for allocating the operational costs associated with the collaboration. It is assumed that the municipality is willing to carry some cost to ensure a stable collaboration for the potential benefits received, e.g., reduced traffic congestion in the city. The model is applied to some illustrative examples, and the cost allocation results are discussed. It is shown that the role of the municipality may be decisive in achieving a stable collaboration between the freight forwarders, and further that the municipality does not necessarily need to contribute to covering the costs.

    sted, utgiver, år, opplag, sider
    WORLD SCIENTIFIC PUBL CO PTE LTD, 2018
    Emneord
    Collaboration; cost allocation; city distribution center; municipality
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-150486 (URN)10.1142/S0217595918500239 (DOI)000441395200005 ()
    Merknad

    Funding Agencies|Swedish Energy Agency; VINNOVA

    Tilgjengelig fra: 2018-08-24 Laget: 2018-08-24 Sist oppdatert: 2018-12-13
    2. A note on the nonuniqueness of the Equal Profit Method
    Åpne denne publikasjonen i ny fane eller vindu >>A note on the nonuniqueness of the Equal Profit Method
    2017 (engelsk)Inngår i: Applied Mathematics and Computation, ISSN 0096-3003, E-ISSN 1873-5649, Vol. 308, s. 84-89Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    When a set of players cooperate, they need to decide how the collective cost should be allocated amongst them. Cooperative game theory provides several methods or solution concepts, that can be used as a tool for cost allocation. In this note, we consider a specific solution concept called the Equal Profit Method (EPM). In some cases, a solution to the EPM is any one of infinitely many solutions. That is, it is not always unique. This leads to a lack of clarity in the characterization of the solutions obtained by the EPM. We present a modified version of the EPM, which unlike its precursor ensures a unique solution. In order to illustrate the differences, we present some numerical examples and comparisons between the two concepts.

    Emneord
    Game Theory, Unique Solution, Solution Concept, EPM, Linear Programming, Lexicography
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-121557 (URN)10.1016/j.amc.2017.03.018 (DOI)000399591500007 ()
    Merknad

    Funding agencies: Swedish Energy Agency

    Tilgjengelig fra: 2015-09-24 Laget: 2015-09-24 Sist oppdatert: 2018-12-13
    3. Incitements for transportation collaboration by cost allocation
    Åpne denne publikasjonen i ny fane eller vindu >>Incitements for transportation collaboration by cost allocation
    Vise andre…
    2018 (engelsk)Inngår i: Central European Journal of Operations Research, ISSN 1435-246X, E-ISSN 1613-9178Artikkel i tidsskrift (Fagfellevurdert) Epub ahead of print
    Abstract [en]

    In this paper, we focus on how cost allocation can be used as a means to create incentives for collaboration among companies, with the aim of reducing the total transportation cost. The collaboration is assumed to be preceded by a simultaneous invitation of the companies to collaborate. We make use of concepts from cooperative game theory, including the Shapley value, the Nucleolus and the EPM, and develop specific cost allocation mechanisms aiming to achieve large collaborations among many companies. The cost allocation mechanisms are tested on a case study that involves transportation planning activities. Although the case study is from a specific transportation sector, the findings in this paper can be adapted to collaborations in other types of transportation planning activities. Two of the cost allocation mechanisms ensure that any sequence of companies joining the collaboration represents a complete monotonic path, that is, any sequence of collaborating companies is such that the sequences of allocated costs are non-increasing for all companies.

    sted, utgiver, år, opplag, sider
    Springer, 2018
    Emneord
    Collaboration, Transportation planning, Monotonic Path, Cost Allocation, Cooperative game theory
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-121558 (URN)10.1007/s10100-018-0530-2 (DOI)
    Forskningsfinansiär
    Swedish Energy AgencyVINNOVA
    Tilgjengelig fra: 2015-09-24 Laget: 2015-09-24 Sist oppdatert: 2018-12-13bibliografisk kontrollert
  • Wildt-Persson, Jacob
    Linköpings universitet, Institutionen för kultur och kommunikation.
    Varför rädsla för kunskap?: En undersökning av olika ståndpunkter inom konstruktivism2018Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    De senaste decennierna har det i samhällsvetenskapliga och humanistiska discipliner funnits stark tendens till relativism. Wikforss skriver att "de senaste decennierna har en form av skepticism vad det gäller möjligheten att uppnå objektiv kunskap fått fäste, både inom delar av universitetsvärlden och samhället i stort". Relativism innebär ungefär att uppfattningen om sanning och falskhet, rätt och fel samt hur man resonerar och motiverar sin uppfattning är produkter av olika konventioner som utgör ramar för hur man bedömer studieobjekt. Detta innebär att uppfattningens auktoritet är begränsad till de sammanhang som gett upphov till den. 

    Vi har inte alltid sett empirisk bevisning som avgörande för kunskap. Eftersom samhällen konstruerat olika fakta speglar de vår konvention och våra intressen. En kunskapsteoretisk relativist vill poängtera att det finns flera system för att hantera kunskap. De bevis vi använder idag har inte nödvändigtvis använts historiskt, utan andra kunskapskällor har varit lika giltiga. Boghossian inleder med en nyhet från The New York Times, om en konflikt mellan den arkeologiska teorin och Sebastian LeBeau, företrädare för en indianstam i South Dakota. Arkeologerna blev kluvna, deras respekt för indianernas kultur var stor, men samtidigt var de engagerade i sin arkeologiska metod. Arkeologerna hade kommit närmare en kunskapsrelativism i sin förståelse för indianernas kultur och vetenskap. Relativisten ser inte från början något rationellt och icke rationellt som två skilda klasser med olika kvalitet. Ingenting är kontextfritt, menar relativisten. Egenskaperna kan därför inte vara rationella utan blir relativistiska antaganden. Boghossians tes är att undersöka relativismens roll i vad som i förhållande till konstruktion till vad som berättigar vad, och poängtera sociala faktorers roll för det vi tror oss tro. När vi bedrivit vetenskap finns har vi alltid haft bakomliggande intressen till vår verksamhet. Dessa intressen är centrala i Boghossians resonemang. Hans teser är det han huvudsakligen behandlar både med kritik och med försvar, och det är konsekvenserna från teserna jag följer i min frågeställning. Hans teser berör vilka fakta vi är berättigade att tro på, vilka fakta vi bör tro på, och vilka fakta vi faktiskt tror på.

    [1]   Carlshamre, Staffan. Recension Fear of Knowledge s. 1. Filosofisk tidskrift. No 1 (2013)

    [2]   Wikforss Åsa; Rädsla för kunskap s. 13,  Fri Tanke förlag, Oxford University Press, 2016

    [3]     Boghossian Paul; Rädsla för kunskap s. 23-24,  Fri Tanke förlag, Oxford University Press, 2016

    [4]   Boghossian (2016) s. 28,  Fri Tanke förlag, Oxford University Press,

    [5]   Boghossian(2016) s. 21,  Fri Tanke förlag, Oxford University Press,

    [6]   Wikforss (2016) s. 17,  Fri Tanke förlag, Oxford University Press,

  • Christerson, Johan
    et al.
    Linköpings universitet, Filosofiska fakulteten. Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Affärsrätt.
    Kihlstrand, Jakob
    Linköpings universitet, Filosofiska fakulteten. Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Affärsrätt.
    Det rättsliga utrymmet för implementering av elektroniska underskrifter vid uppfyllandet av formkrav: En studie av formkraven2018Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Elektroniska underskrifter är en relativt ny metod för att ingå bindande avtal. Tanken med tekniken är att den ska effektivisera, förenkla och öka säkerheten för användarna vid ingående av avtal. Det kan dock uppstå problem när lagstiftning anpassas till att reglera ny teknik, eftersom det är viktigt att lagstiftaren fortsätter att ta hänsyn till de skyddsintressen som ligger bakom gällande rätt. Denna uppsats belyser och diskuterar rättsliga hinder som föreligger vid användandet av elektroniska underskrifter, vid upprättande av de tre, privaträttsligt mest vanliga, rättshandlingarna som kräver en viss form för giltighet: överlåtelse av fast egendom, upprättande av testamente eller äktenskapsförord. Uppsatsen utreder hur den nya EU-förordningen eIDAS ((EU) nr 910/2014) har påverkat svenska myndigheters förhållningssätt till elektroniska underskrifter och elektroniska handlingar. Från presumtionen att det var fysiska handlingar som krävdes, om inte särskilda regler godkände elektroniska rutiner, till att elektroniska rutiner gäller om inte särskilda formkrav förbjuder det. Vidare förklaras förenklat tekniken bakom avancerade- och kvalificerade signaturer samt elektroniska dokument.

    Formkraven för skriftlighet, underskrift, bevittning och registrering och de skyddsintressen som ligger bakom dessa analyseras. Formkraven till ovan nämnda rättshandlingar kan till viss del tillgodoses med elektroniska signaturer och dokument, men i dagsläget krävs det en fysisk underskrift för att göra ovan nämnda rättshandlingar giltiga, på grund av den tolkning av begreppet underskrift som har gjorts i Ds 2003:29. Vidare analyseras hur sakrätten, rent teoretiskt, skulle kunna förändras genom en potentiell lagändring eller om en ny tolkning av begreppet underskrift medför att elektroniska signaturer kan användas vid överlåtelse av fast egendom. I uppsatsen diskuteras även de förtjänster och risker som en lagändring skulle kunna innebära, och hur dessa bör vägas mot varandra, för att sedan konstatera om en ökad implementering av elektroniska rutiner är önskvärd eller inte.

  • Ågren, Axel
    Linköpings universitet, Institutionen för samhälls- och välfärdsstudier, Avdelningen Åldrande och social förändring. Linköpings universitet, Filosofiska fakulteten.
    Loneliness among older people in the Swedish media: Constructions, discourses and the designation of responsibility2018Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Feelings of belonging or not belonging to other people are commonly seen as an essential and universal part of human existence. How loneliness is talked about and understood is, however, found to differ depending on historical, cultural and societal contexts. Today, there are intense discussions on loneliness among older people in the Swedish news-press. Constructions within mass media and - in this licentiate thesis - news-press are found to have a significant influence on how older people evaluate their own life and how older people are treated by the surrounding society. Research with this focus is, however, scarce despite the large amount of studies on loneliness and despite research on constructions of older people within mass media being a frequently addressed issue for ageing research. The aim of this thesis is to explore how loneliness among older people is constructed and how the responsibility for reducing loneliness is designated within the Swedish news-press.

    In Paper 1 the empirical material consisted of 94 news-press articles from the years 2013-2014. The prime finding was that loneliness was not the main focus in the articles from the Swedish news-press. The concept was used more to motivate the need for political change, enhancing the importance of volunteer work and described as a risk factor within research reports. The material analysed in Paper 2 consisted of 40 news-press articles from October 2016. The responsibility for reducing loneliness among older people was found to be designated between welfare state institutions on different levels. Institutions and political parties both defend the planned or performed measures to reduce loneliness, but also admit to not doing enough in this regard. Older people were found to be constructed as recipients of activities for reducing loneliness, and the “we” in “society” were those who should perform activities in order to reduce loneliness among older people.

    The main overall finding of the thesis is that loneliness was not the main focus in the articles from Swedish news-press. Instead, loneliness was used as a motive for political change and to enhance the value of volunteer work. Furthermore, loneliness among older people is understood as a problem that needs to be solved. The contexts and logics of the mass media were found to have an influence on how loneliness among older people was constructed, as the issue was mainly addressed in local debate articles with ambitions of achieving change.

    Delarbeid
    1. What are we talking about?: Constructions of loneliness among older people in the Swedish news-press
    Åpne denne publikasjonen i ny fane eller vindu >>What are we talking about?: Constructions of loneliness among older people in the Swedish news-press
    2017 (engelsk)Inngår i: Journal of Aging Studies, ISSN 0890-4065, E-ISSN 1879-193X, Vol. 41, s. 18-27Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Loneliness among older people is an issue that engages the general public and various professions and organizations in contemporary Swedish society. One public arena where this engagement is particularly evident is within the Swedish news-press, where articles on loneliness among older people are frequently published. Loneliness is commonly perceived as significantly related to ageing and older people. In addition, the mass media is considered to have a crucial influence in shaping general perceptions of older people. The aim of this study is to examine how loneliness among older people is constructed in the Swedish news-press and whether there is a prevailing “loneliness discourse” within this context. The empirical material consists of 94 articles from the Swedish news-press from the years 2013–2014. Two dominating discourses was found. Loneliness — within the discourse of eldercare, politics and the welfare society, is primarily written about in news articles and debate articles by a variety of authors, such as politicians and representatives from organizations. Within this discourse, loneliness is utilized as a concept to motivate the need for political change and the allocations of resources and to amplify deficiencies within eldercare, politics and the welfare society. The second discourse, Loneliness — within the discourse of volunteer work, is addressed in reportage articles written by journalists. In this discourse focus was on depicting volunteers and enhancing the importance of volunteer work. Here, loneliness serves as a motive for performing volunteer work. In addition, the discourse of Research reports on older people's health was found, although less significant compared to the two major discourses. Within this discourse ageing is presented as a risk, where loneliness is one of these risk factors. Despite some minor differences, loneliness, within all three discourses, is given the meaning of being a problem that needs to be solved. A central finding in this study is that focus in the articles, from Swedish news-press, is not mainly on loneliness but rather on eldercare, politics and the welfare state, volunteer work and health among older people. Loneliness is, consequently, used as a concept to motivate the need for political change and the allocation of resources for older people, to enhance the values of volunteer work and to emphasize the risks associated with ageing.

    sted, utgiver, år, opplag, sider
    Elsevier, 2017
    Emneord
    Loneliness, Older people, Mass media, Discourse theory
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-136131 (URN)10.1016/j.jaging.2017.03.002 (DOI)000404490400003 ()28610751 (PubMedID)
    Merknad

    Fundingagencies: Norrkepingsfonden [KS 2013/0721]

    Tilgjengelig fra: 2017-03-28 Laget: 2017-03-28 Sist oppdatert: 2018-12-13bibliografisk kontrollert
    2. Reducing loneliness among older people – who is responsible?
    Åpne denne publikasjonen i ny fane eller vindu >>Reducing loneliness among older people – who is responsible?
    2018 (engelsk)Inngår i: Ageing & Society, ISSN 0144-686X, E-ISSN 1469-1779Artikkel i tidsskrift (Fagfellevurdert) Epub ahead of print
    Abstract [en]

    In the Swedish news-press, loneliness among older people is presented as a severe problem that needs to be solved. The issue of who is responsible for reducing loneliness and how this responsibility is designated is, however, rarely discussed. In this study, we have analysed how responsibility is designated and constructed in articles from the Swedish news-press. Focus has been on identifying responsibility in discourses proceeding from the concept of subject positions. This concept has enabled analysis on how responsibility is negotiated and who is positioned as a responsible actor with the ability to perform actions that reduce loneliness. Three dominating discourses were found. In the discourse of responsibility within politics and the welfare state, the responsibility is both self-taken and designated to other institutions held responsible for not initiating sufficient measures to reduce loneliness. In the discourse of responsibility within societal and evolutionary perspectives on loneliness, developments beyond the individual's control are considered to contribute to loneliness. At the same time ‘we’ in ‘society’ are considered capable of reducing loneliness, thereby constructing individuals as responsible actors. Within the discourses of responsibility within senior organisations, both senior organisations and people who participate in activities are constructed as responsible actors. In conclusion, the responsibility for reducing loneliness is, apart from the discourse on senior organisations, designated to those working with older people.

    sted, utgiver, år, opplag, sider
    Cambridge: Cambridge University Press, 2018
    Emneord
    loneliness, responsibility, news-press, subject positions, discourses
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-153334 (URN)10.1017/S0144686X18001162 (DOI)
    Tilgjengelig fra: 2018-12-13 Laget: 2018-12-13 Sist oppdatert: 2018-12-14
  • Mikhaylevskaya, Valentina
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring.
    Consumer behavior analysis through nudging: A study on nudging of single-used hospital garments in healthcare sector of Region Östergötland2018Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Region Östergötland has encountered issue in ecological and economical overconsumption of single-used garments in healthcare sector among medical staff in Universitetssjukhuset Linköping. Proper approaches to reach solutions towards decrease of usage of single-used garments were targeted to be implemented for employees of healthcare sector. Two goals were established for this study. First of all, it was aimed to analyse consumer behaviour of employees in healthcare sector of Östergötland region to find out reasons that lay behind increase of single-time garments by employees. Secondly, the aim was targeted to examine what nudging techniques, if any, are feasible to use in positively changing current consumer behavior. The findings showed that nudging has a strong potential to be regarded as an effective tool in influencing healthcare workers of Linköping University Hospital disposable garments usage. Main behavioural reasons that triggered increase of disposable garments usage were detected as lack of information and old habits of medical staff. Application of information disclosure, framing, feedback and social norms nudging techniques were identified to have promising possibilities in impacting current behaviour and raise healthcare workers awareness about their consumption patterns.

  • Mannsdorff Djurberg, Christoffer
    Linköpings universitet, Institutionen för studier av samhällsutveckling och kultur, Avdelningen för Kultur, samhälle, mediegestaltning – KSM.
    Arbetsmoral som val: En innehållsanalys av intervjuer med fem arbetsgivare om deras syn på den icke-arbetande2018Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    Employers can be viewed as a center of a so called work ideology. This ideology is at least as old as the ancient greeks and effects how we view people who work, and people who for different reasons do not work. Work ethic as a choice is a content analysis of interviews with five employers regarding work and leisure. This study shows that the interviewed employers speak about labour as something everybody must, and will at some point in life, do. People who are on sick leave are to be respected, and all decisions regarding the persons use of their time should be decided by their doctor. No one should get money without first contributing to society by working in a wage paying job. Work is however something healthy and makes people feel good, mostly because of the social context and the feeling of being part of something; of contributing. The work ideology is highly present in the interviewees language and differs between them in accordance with difference in class and economic, social and cultural capital.

  • Vernmark, Kristofer
    et al.
    Linköpings universitet, Institutionen för beteendevetenskap och lärande, Psykologi. Linköpings universitet, Filosofiska fakulteten.
    Hesser, Hugo
    Linköpings universitet, Institutionen för beteendevetenskap och lärande, Psykologi. Linköpings universitet, Filosofiska fakulteten.
    Topooco, Naira
    Linköpings universitet, Institutionen för beteendevetenskap och lärande, Psykologi. Linköpings universitet, Filosofiska fakulteten.
    Berger, Thomas
    Department of Clinical Psychology and Psychotherapy, University of Bern, Bern, Switzerland.
    Riper, Heleen
    Department of Clinical, Neuro-, & Developmental Psychology, Faculty of Behavioural and Movement Sciences, VU Amsterdam, Amsterdam, The Netherlands.
    Luuk, Liisa
    Linköpings universitet, Institutionen för beteendevetenskap och lärande. Linköpings universitet, Filosofiska fakulteten.
    Backlund, Lisa
    Linköpings universitet, Institutionen för beteendevetenskap och lärande. Linköpings universitet, Filosofiska fakulteten.
    Carlbring, Per
    Department of Psychology, Stockholm University, Stockholm, Sweden; Department of Psychology, University of Southern Denmark, Denmark.
    Andersson, Gerhard
    Linköpings universitet, Institutionen för beteendevetenskap och lärande, Psykologi. Linköpings universitet, Filosofiska fakulteten. Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.
    Working alliance as a predictor of change in depression during blended cognitive behaviour therapy2018Inngår i: Cognitive Behaviour Therapy, ISSN 1650-6073, E-ISSN 1651-2316, s. 1-15Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Blended Cognitive Behaviour Therapy (bCBT) is a new form of treatment, mixing internet-based modules and face-to-face therapist sessions. How participants rate the therapeutic alliance in bCBT has not yet been thoroughly explored, and neither is it clear whether therapist- and patient-rated alliances are predictors of change in depression during treatment. Depression and alliance ratings from 73 participants in a treatment study on bCBT (part of the E-COMPARED project) were analysed using growth curve models. Alliance, as rated by both patients and therapists, was high. The therapist-rated working alliance was predictive of subsequent changes in depression scores during treatment, whereas the patient-rated alliance was not. A therapeutic alliance can be established in bCBT. The role of the therapist-rated alliance seems to be of particular importance and should be carefully considered when collecting data in future studies on bCBT.

  • Johansson, Viktor
    et al.
    Linköpings universitet, Institutionen för datavetenskap, Programvara och system.
    Vallén, Alexander
    Linköpings universitet, Institutionen för datavetenskap, Programvara och system.
    Random testing with sanitizers to detect concurrency bugs in embedded avionics software2018Independent thesis Basic level (degree of Bachelor), 10,5 poäng / 16 hpOppgave
    Abstract [en]

    Fuzz testing is a random testing technique that is effective at finding bugs in large software programs and protocols. We investigate if the technology can be used to find bugs in multi-threaded applications by fuzzing a real-time embedded avionics platform together with a tool specialized at finding data races between multiple threads. We choose to fuzz an API (available to applications executing on top) of the platform. This thesis evaluates aspects of integrating a fuzzing program, AFL and a sanitizer, ThreadSanitizer with an embedded system. We investigate the modifications needed to create a correct run-time environment for the system, including supplying test data in a safe manner and we discuss hardware dependencies. We present a setup where we show that the tools can be used to find planted data races, however slowdown introduced by the tools is significant and the fuzzer only managed to find very simple planted data races during the test runs. Our findings also indicate what appear to be conflicts in instrumentation between the fuzzer and the sanitizer.  

  • Johansson, Hanna
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Medie- och Informationsteknik. Linköpings universitet, Tekniska fakulteten.
    Khullar, Sofie
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Medie- och Informationsteknik. Linköpings universitet, Tekniska fakulteten.
    Graphical User Interfaces for Multi-Touch Displays supporting Public Exploration and Guided Storytelling of Astronomical Visualizations2018Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    This report presents the development and implementation of a graphical user interface (GUI) for multi-touch displays as well as an application programming interface (API) for guided storytelling of astronomical visualizations. The GUI and the API is built using web technologies and the GUI is rendered in an OpenGL environment. The API is meant to provide the infrastructure needed to create different stories for the public, based on astronomical data. Both the resulting GUI and the API is developed such that it can be further developed and customized for different purposes.

  • Arntén, Linnea
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Medie- och Informationsteknik. Linköpings universitet, Tekniska fakulteten.
    de Klerk, Paulina
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Medie- och Informationsteknik. Linköpings universitet, Tekniska fakulteten.
    Att döma hunden efter håren: En designstudie i bokomslagets utformning och dess betydelse för högstadiekillars läslust2018Independent thesis Basic level (degree of Bachelor), 10,5 poäng / 16 hpOppgave
    Abstract [en]

    Statistik visar på att unga, framför allt killar, läser allt mindre. Detta kan antas bero på en rad olika faktorer, bland annat de senaste årens teknologiska framsteg. Denna studie ämnar undersöka hur ett omslag inom genren ungdomslitteratur kan utformas för att tilltala högstadiekillar samt hur stor betydelse omslaget har för målgruppens läslust. Utifrån insamlad data från målgruppen och yrkesverksamma inom bokbranschen samt relevanta teorier, har sex olika designförslag tagits fram. Designförslagen baserades på befintliga titlar från 2017. För att kunna uppfylla studiens syfte lät vi målgruppen och personer i närliggande grupper rent demografiskt värdera dessa, såväl som en formgivare på Bonnier Carlsen. Värderingen påvisade att målgruppen anser att det viktigaste med ett bokomslag är att det förmedlar en känsla. Avbildande illustrationer eller fotografier och tilltalande färger verkar spela en central roll för ett bokomslags attraktionskraft hos målgruppen. Typografi har visat sig vara mindre viktigt än motivet, medan helheten är det som verkar vara viktigast. Studien visar även att bokomslag har en stor betydelse för högstadiekillars läslust.

  • Nilsson, Jerker
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Kommunikations- och transportsystem. Linköpings universitet, Tekniska fakulteten.
    Paket och styckegodshantering hos DB Schenker i Örebro - Flödeskartläggning för effektivare hantering2018Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Deutsche Bahn Schenker är ett tredjepartslogistikföretag som har en av sina terminaler placerade i Örebro. Schenker hanterar dagligen en mängd olika sorters produkter och varor antingen i formen av paket eller styckegods. Genom att efterfrågan på tredjepartslogistik ökar ställs större krav på Schenker att klara av att hantera allt fler paket och styckegods på kort tid. Eftersom det är en stor variation av anländande styckegods och paket ställs höga krav på att terminalpersonalen utför hanteringsarbetet effektivt. Tar det för lång tid att utföra arbetet eller någonting går fel kan leveranser riskera att bli försenade eller problem skapas för nästkommande arbetsmoment. Syftet med studien är att identifiera åtgärdsförslag till Schenker hur de kan förbättra hanteringsarbetet för paket och styckegods på sin terminal i Örebro. Genom att kartlägga nuvarande flöde med hjälp av bland annat intervjuer, observationer samt analys av historisk data har detta syfte besvarats. Studien resulterade i att totalt 13 problem identifierades samt elva åtgärdsförslag.

  • Postigo, Ivan
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Kommunikations- och transportsystem. Linköpings universitet, Tekniska fakulteten.
    Fingerprinting methods for positioning: A study on the adaptive enhanced cell identity method2018Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Fingerprinting methods for positioning is an area of great interest, this thesis presents a study on the Adaptive Enhanced Cell Identity (AECID) fingerprinting method for positioning. By creating a map of the radio characteristics in a geographical region, the AECID method is able to locate a UE by gathering information of the radio conditions of its current location. By performing positioning in this manner, there is no need for additional signaling, which is a better usage of the radio resources. This thesis presents a new approach for the creation of fingerprints together with alternative methodology at each step proposed by the AECID method. These alternatives are implemented and evaluated for real and simulated scenarios. Accuracy performance metrics are discussed based on different formats supported for reporting position. The alternatives presented in this thesis will show not only an enhancement on the accuracy levels but most importantly, the impact of each step on the final performance of the method.

  • Lampi, Maria
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för Kirurgi, Ortopedi och Onkologi. Linköpings universitet, Medicinska fakulteten.
    Junker, Johan
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för Kirurgi, Ortopedi och Onkologi. Linköpings universitet, Medicinska fakulteten.
    Tabu, John S.
    Department of Disaster Risk Management, Moi University College of Health and Science, Eldoret, Kenya.
    Berggren, Peter
    Linköpings universitet, Institutionen för datavetenskap, Interaktiva och kognitiva system. Linköpings universitet, Filosofiska fakulteten.
    Jonson, Carl-Oscar
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för Kirurgi, Ortopedi och Onkologi. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Katastrofmedicinskt centrum.
    Wladis, Andreas
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för Kirurgi, Ortopedi och Onkologi. Linköpings universitet, Medicinska fakulteten.
    Potential benefits of triage for the trauma patient in a Kenyan emergency department2018Inngår i: BMC Emergency Medicine, ISSN 1471-227X, E-ISSN 1471-227X, Vol. 18, nr 49, s. 1-7Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background

    Improved trauma management can reduce the time between injury and medical interventions, thus decreasing morbidity and mortality. Triage at the emergency department is essential to ensure prioritization and timely assessment of injured patients. The aim of the present study was to investigate how a lack of formal triage system impacts timely intervention and mortality in a sub-Saharan referral hospital. Further, the study attempts to assess potential benefits of triage towards efficient management of trauma patients in one middle income country.

    Methods

    A prospective descriptive study was conducted. Adult trauma patients admitted to the emergency department during an 8-month period at Moi Teaching and Referral Hospital in Eldoret, Kenya, were included. Mode of arrival and vital parameters were registered. Variables included in the analysis were Injury Severity Score, time before physician’s assessment, length of hospital stay, and mortality. The patients were retrospectively categorized according to the Rapid Emergency Triage and Treatment System (RETTS) from patient records.

    Results

    A total of 571 patients were analyzed, with a mean Injury Severity Score of 12.2 (SD 7.7) with a mean length of stay of 11.6 (SD 18.3) days. The mortality rate was 1.8%. The results obtained in this study illustrate that trauma patients admitted to the emergency department at Eldoret are not assessed in a timely fashion, and the time frame recommendations postulated by RETTS are not adhered to. Assessment of patients according to the triage algorithm used revealed a significantly higher average Injury Severity Score in the red category than in the other color categories.

    Conclusion

    The results from this study clearly illustrate a lack of correct prioritization of patients in relation to the need for timely assessment. This is further demonstrated by the retrospective triage classification of patients, which identified patients with high ISS as in urgent need of care. Since no significant difference in to time to assessment regardless of injury severity was observed, the need for a well-functioning triage system is apparent.

  • Åkesson, Julia
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Bioinformatik.
    Robust Community Predictions of Hubs in Gene Regulatory Networks2018Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Many diseases, such as cardiovascular diseases, cancer and diabetes, originate from several malfunctions in biological systems. The human body is regulated by a wide range of biological systems, composed of biological entities interacting in complex networks, responsible for carrying out specific functions. Some parts of the networks, such as hubs serving as master regulators, are more important for maintaining a function. To find the cause of diseases, where hubs are possible disease regulators, it is critical to know the structure of these biological systems. Such structures can be reverse engineered from high-throughput data with measured levels of biological entities. However, the complexity of biological systems makes inferring their structure a complicated task, demanding the use of computational methods, called network inference methods. Today, many network inference methods have been developed, that predicts the interactions of biological networks, with varying degree of success. In the DREAM5 challenge 35 network inference methods were evaluated on how well interactions in gene regulatory networks (GRNs) were predicted. Herein, in contrast to the DREAM5 challenge, we have evaluated network inference methods’ ability to predict hubs in GRNs. In accordance with the DREAM5 challenge, different methods performed the best on different data sets. Moreover, we discovered that network inference methods were not able to identify hubs from groups of similarly expressed genes. Also, we noticed that hubs in GRNs had a distinct expression in the data, leading to the development of a new method (the PCA method) for the prediction of hubs. Furthermore, the DREAM5 challenge showed that community predictions, combining the predictions from many network inference methods, resulted in more robust predictions of interactions. Herein, the community approach was applied on predicting hubs, with the conclusion that community predictions is the more robust approach. However, we also concluded that it was enough to combine 6-7 network inference methods to achieve robust predictions of hubs.

  • Olsson, Martin
    Linköpings universitet, Matematiska institutionen, Beräkningsmatematik.
    Vortex Formation in Free Space2018Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Aircraft trailing vortices is an inevitable side effect when an aircraft generates lift. The vortices represent a danger for following aircraft and forces large spacing between landing and take off at airports. Detailed knowledge about the dynamics of aircraft trailing vortices is therefore needed to increase airport capacity and aviation safety. In this thesis, an accurate numerical simulation of aircraft trailing vortices is performed. The vortices undergo an expected instability phenomena followed by a reconnection process. The reconnection process is studied in detail. During the reconnection, theoretically described structures can be observed.

  • Ekström, Joakim
    Linköpings universitet, Institutionen för systemteknik, Reglerteknik.
    3D Imaging Using Photon Counting Lidar on a Moving Platform2018Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    The problem of constructing high quality point clouds based on measurements from a moving and rotating single-photon counting lidar is considered in this report. The movement is along a straight rail while the lidar sensor rotates side to side. The point clouds are constructed in three steps, which are all studied in this master’s thesis. First, point clouds are constructed from raw lidar measurements from single sweeps with the lidar. In the second step, the sensor transformation between the point clouds constructed in the first step are obtained in a registration step using iterative closest point (ICP). In the third step the point clouds are combined to a coherent point cloud, using the full measurement. A method using simultaneous localization and mapping (SLAM) is developed for the third step. It is then compared to two other methods, constructing the final point cloud only using the registration, and to utilize odometric information in the combination step. It is also investigated which voxel discretization that should be used when extracting the point clouds.

    The methods developed are evaluated using experimental data from a prototype photon counting lidar system. The results show that the voxel discretization need to be at least as large as the range quantization in the lidar. No significant difference between using registration and SLAM in the third step is observed, but both methods outperform the odometric method.

  • Holgersson, Stefan
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Informatik. Linköpings universitet, Filosofiska fakulteten.
    Justitieministern: “Sätta hårt mot hårt” : En studie av polisens användning av våld och förmåga att hantera konflikter2018Rapport (Annet vitenskapelig)
    Abstract [sv]

    Denna rapport skulle kunna fylla en uppgift liknande en haveriutredning angående polisers förmåga att hantera konflikter och använda våld. När det gäller haveriutredningar, till exempel inom flygfarten väljer man att lyfta fram en situation som har gått fel och inte att studera alla lyckade landningar. I och med att fokus är på förbättringsbehov kan det finnas en risk att någon drar slutsatsen att övergrepp och otillåten våldsanvändning bland polispersonal är ett omfattande problem. Så är inte fallet. Det finns väldigt många bra poliser som mestadels gör bra ingripanden. Det hade gått att skriva en rapport om dessa ingripanden, men det finns en anledning att haveriutredningar inom flygfarten försöker lokalisera orsaker till problem och inte fokusera på bra landningar. Syftet med denna rapport är att komma tillrätta med problem och utveckla polisverksamheten. Därför är fokus på förbättringsbehov.

    Utbildning av poliser i konflikthantering och våldsanvändning

    I konfliktsituationer är det betydelsefullt att poliser har en god förmåga att kommunicera och om så behövs, en hög förmåga att bruka våld på ett väl avvägt sätt. Dessutom måste poliser ofta under stress fatta beslut med ett bristfälligt beslutsunderlag.

    Det förhållandevis nya konceptet POLKON (polisiär konflikthantering) lyfts i rapporten fram som ett stort steg i rätt riktning vad gäller polisens hantering av konflikter och användning av våld. Det framgår dock att det finns stora brister inom detta utbildningsområde. Det gäller både grundutbildning och fortbildning. Ett flertal av polisutbildningens praktiska moment skulle snarare kunna definieras som ett ”prova-på-tillfälle” än som övningar som syftar till att befästa kunskaperna. Exempelvis genomför en polisstudent i genomsnitt under hela sin utbildning en mörkerskjutning trots att de flesta skjutningarna inträffar under dåliga ljusförhållanden.

    Skjutträning är många gånger statisk för att klara av ett kompetensprov som inte är anpassat efter de krav som finns på hur poliserna ska agera i verkligheten. Det finns till exempel inget moment under kompetensprovet som handlar om att göra en bedömning om huruvida polis ska skjuta eller ej i en viss situation. Inte heller att skjuta ett varningsskott eller att skjuta i benet. Om en polis skjuter ett varningsskott eller träffar i benet under kompetensprovet får han eller hon underkänt. Övningar i taktisk reträtt förekommer sällan eller aldrig. Liksom träning att söka skydd framför att verka med vapnet och att deeskalera en situation. Både grund och fortbildningen brister även när det gäller andra typer av våldsanvändning. Det har bland annat vid intervjuer framförts att det är ett glapp/tomrum mellan de tekniker som övas för att hantera en relativt lugn person till de tekniker som övas för att kunna agera i ”värstascenarier”.

    En av de allvarligaste utbildningsbristerna i polisers konflikthantering är att praktiska moment i att öva kommunikation är så få att det inte finns förutsättningar att bygga upp en professionell kommunikationsförmåga i konfliktsituationer. Istället styr polisernas tidigare erfarenheter och personliga egenskaper denna förmåga. Att personer med en liten livserfarenhet rekryteras är därför ett problem i sammanhanget.

    Trots att nyutexaminerade poliser behöver utveckla ett antal förmågor har fortbildningen bara ambitionsnivån att utbildningen ska upprätthålla deras kunskap. I praktiken når man inte ens upp till detta mål. Polismyndigheten är beredd att frångå den absolut minsta mängd årlig fortbildning som myndigheten själva angett som nödvändig för att polispersonal ska upprätthålla en acceptabel kunskapsnivå inom ett område som man uttrycker är avgörande för polisers arbetsmiljö, medborgarnas rättssäkerhet och Polismyndighetens trovärdighet. Polismyndighetens hantering av utbildningsfrågor kan sammanfattas på det sätt en instruktör i polisiär konflikthantering gjorde: ”Det är fullkomligt vansinnigt”.

    Bristande kritisk reflektion och ett fokus på att presentera tilltalande bilder av verksamheten

    Ett problem i sammanhanget är att polisen har en låg förmåga att ta till sig av kritik och stora brister i att reflektera kritiskt kring sin egen del i situationer som uppkommit. Polismyndigheten är långt ifrån att vara en lärande organisation. I rapporten framgår att Polismyndigheten har en förkärlek till att skylla på externa faktorer för att förklara ett skeende och att stor kraft läggs på att presentera tilltalande bilder av verksamheten. Även om ett sådant förfaringssätt kan ge ett gott intryck av polisen, vilket ur vissa aspekter är positivt, undertrycker det ett behov av förändring (se t.ex. Holgersson och Wieslander, 2017; Holgersson, 2018b). Denna omständighet finns anledning att vara medveten om när Polismyndigheten hänvisar till framtida aktiviteter som exempelvis en utbildningsinsats eller ny inriktning på polisernas utbildning i polisiär konflikthantering. Man bör fästa samma tilltro till denna typ av budskap från Polismyndighetens sida som till information från ett kommersiellt företags marknadsavdelning (inom polisen kallad kommunikationsavdelning) som gör reklam för en produkt, där vare sig högsta ledning, kvalitetsansvarig, ansvarig för inköps- eller marknadsavdelningen behöver ta ansvar för om produkten inte lever upp till det som utlovats. Den som riskerar bli straffad om produkten visar sig vara farlig är den som arbetat i kassan och sålt produkten.

    Rekryteringsprocessen och att hantera signaler om olämpligt beteende

    Det finns indikationer på att rekryteringsprocessen av poliser har brister. Frågetecken finns kring utformningen och utfallet av den inledande rekryteringsprocessen. Vidare har individer fått anställning som polis trots att tydliga signaler kommit under utbildningstiden på att de inte är lämpliga. Många som intervjuats har uppgett att det finns indikationer på att kravet på att få ett visst antal poliser har gjort att kvantitet går före kvalitet. Eftersom ett felaktigt beteende från en enskild polis kan få stora konsekvenser anges detta förhållande som problematiskt.

    Stor vikt fästs vid att en juridisk process ska visa om ett agerande från polisens sida var korrekt eller ej. Det gör det svårare för Polismyndigheten att komma tillrätta med olämpliga individer och olämpligt beteende. Det är olyckligt när polisers handlingsutrymme definieras som att det är acceptabelt att agera på ett visst sätt så länge inte en juridisk prövning leder till en fällande dom. Problemet är att det kan ha begåtts juridiska fel som är så stora att det borde ha lett till en fällande dom, men att polisens Avdelning för särskilda utredningar (SU) gjort ett dåligt arbete. Det kan ha begåtts juridiska fel som borde lett till en fällande dom, men att detta är svårt att bevisa (även när utredningsprocessen skötts på ett bra sätt). Det kan även ha begåtts fel som inte är av den arten att de ens ska leda till åtal.

    Flygbranschen har valt en annan väg och delvis frångått att straffa enskilda. Till exempel genom att man i flera länder, bland annat Sverige, har gjort det möjligt för anställda att rapportera fel som de själva har begått utan att löpa risk att lagföras. Målet är istället att snabbt identifiera och rätta till säkerhetsproblem (se t.ex. Brandel, 2002). Polismyndighetens nuvarande förhållningsätt innebär i normalfallet försvar och inte att försöka få fram vilka lärdomar som kan dras av en händelse. Ett problem i sammanhanget är polisers anmälningsskyldighet. Får polis kännedom om brott som hör under allmänt åtal ska det rapporteras enligt polislagen. Här behövs en förändring som inte ligger inom Polismyndighetens beslutsmandat för att skapa bättre förutsättningar för att den ska bli något som skulle kunna betecknas som en lärande organisation.

    Hårda tag som lösningen

    En viss problematik kan ha olika orsaker som kan kräva olika åtgärder. Att mer eller mindre slentrianmässigt hävda att hårda tag är lösningen kan få motsatta effekter. Att agera på ett hårt sätt som inte är genomtänkt ökar risken för en polarisering, där förtroende och tillit till polisen och andra samhällsinstitutioner kan minska i vissa grupper. Att poliser i sin externa kommunikation om sitt arbete använder ord som ”utplåna”, ”neutraliserad” och ”anfall” kan ge intryck av att polisen är en stridande part i något som närmast kan liknas vid ett krig. Att måla upp polisen som en stridande part kan öka risken för angrepp mot poliser och även påverka hur polispersonalens agerar i vissa områden och mot vissa grupperingar. En ond cirkel kan uppstå.

    När polisen har utsatts för angrepp hävdar Polismyndigheten ofta att det är ett kvitto på att polisen har skapat ett tryck mot rätt personer och grupperingar. Angreppen tolkas inte sällan som att det finns anledning att öka trycket ytterligare. Att ensidigt tolka angreppen som ett bevis på lyckat polisarbete kan vara problematiskt om andra orsaker helt eller delvis ligger bakom angreppen. Att poliserna blir ”tuffare” kan få en motsatt effekt, förvärra en situation och exempelvis stärka gängidentiteten i löst sammansatta gäng. En genomgång av olika yttranden från Polismyndigheten visar att myndigheten ofta framställer sig själv som ett offer. Avsaknaden av kritisk reflektion kring att polisen faktiskt kan ha varit en medaktör till att en problematik har uppstått är tydlig i många fall. Hur strategiskt är det exempelvis att Polismyndigheten har upprättat en lista på särskilt utsatta områden när problemen verkar skilja sig åt mycket både i omfattning och i karaktär? Genom polisens definition finns en risk för stigmatisering och att det kan uppfattas finnas en liknande lösning på problem och konflikter i respektive område.

    I rapporten ges exempel på att Polismyndigheten skickar tydliga interna signaler om att repressiva och hårda tag premieras. Brottsförebyggande verksamhet som kan minska risken för framväxten av extremism och andra problem har helt hamnat i skymundan av en satsning på repressiva åtgärder. För att polisens verksamhet inte ska bli för ensidigt inriktad, och att även det brottsförebyggande arbetet ska kunna få genomslag krävs en medveten strategi och konkreta handlingar som visar att detta ses som viktigt. Inte bara ord.

    Användning av tilldelade resurser

    Data som framkommit vid intervjuer och deltagande observation visar att Polismyndigheten kan använda sina resurser på ett betydligt bättre sätt än vad som sker i dagsläget. Polismyndigheten kommer dock lätt undan med svepande förklaringar om resursbrist. Tillräcklig information presenteras inte för att underlätta för personer utanför polisens organisation att kunna göra adekvata värderingar om dess prioriteringar och fördelning av resurser till olika verksamhetsfält är rimliga, bland annat vad gäller omfattningen på utbildningsverksamheten.

    Behoven av omfördelning av resurser blir tydliga om man till exempel studerar polisarbete i glesbygd. Relativt små omfördelningar av resurser skulle ha stor betydelse för den polisiära förmågan i glesbygdsområden som till ytan utgör mer än sjuttiofem procent av Sverige. De fåtal polispatruller som Polismyndigheten levererar att utföra arbetet i dessa områden står inte i rimlig proportion till myndighetens totalt tilldelade resurser. Det finns ett behov av att på ett helt annat sätt reflektera över hur resurserna används inom Polismyndigheten bland annat gällande storlek på administration och staber, men också när det gäller andra former av prioriteringar. Vilken effekt skulle exempelvis förmågan att hantera dödligt våld fått om de 100 miljoner kronor och årliga driftskostnader som avsattes till inköp av två helikoptrar istället hade lagts på annat?

    Att Polismyndigheten har valt att ha en kommunikationsavdelning på nästan 200 anställda kan användas som utgångspunkt för att analysera om Polismyndigheten fördelar sina resurser på ett sätt som ger högsta möjliga marginalnytta. Det är svårt att se att denna nytta blir högre vid ett bibehållande av nuvarande storlek på kommunikationsavdelningen än vid en omfördelning av resurserna till kärnverksamheten. Rikspolischefen har dock försvarat nuvarande storlek på kommunikationsavdelningen. Inställningen att det är bättre att behålla en överdimensionerad kommunikationsavdelning än att omfördela resurserna till kärnverksamheten är logisk om det bedöms som viktigare att måla upp tilltalande bilder av verksamheten än hur verksamheten i praktiken fungerar. Dessutom finns en övertro gällande den interna effekten av skrivna texter (se Ekman, 1999; Ivarsson-Westerberg, 2004; Holgersson, 2018b). I rapporten framgår att detta förhållande är högst aktuellt vad gäller polisens användning av våld och förmåga att hantera konflikter.

    Smarta tag istället för hårda tag

    Ett kriterium på om Polismyndigheten agerar på ett smart sätt är huruvida beslut och handlingar är välgrundade i forskning kopplad till en analytisk process. I det näst sista kapitlet av denna rapport belyses ett antal viktiga behov av förändring kring de frågor rapporten berör.

  • Nordström, Jan
    et al.
    Linköpings universitet, Matematiska institutionen, Beräkningsmatematik. Linköpings universitet, Tekniska fakulteten.
    La Cognata, Cristina
    Linköpings universitet, Matematiska institutionen, Beräkningsmatematik. Linköpings universitet, Tekniska fakulteten.
    Energy Stable Boundary Conditions for the Nonlinear Incompressible Navier-Stokes Equations2019Inngår i: Mathematics of Computation, ISSN 0025-5718, E-ISSN 1088-6842, Vol. 88, nr 316, s. 665-690Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The nonlinear incompressible Navier-Stokes equations with different types of boundary conditions at far fields and solid walls is considered. Two different formulations of boundary conditions are derived using the energy method. Both formulations are implemented in both strong and weak form and lead to an estimate of the velocity field.

    Equipped with energy bounding boundary conditions, the problem is approximated by using discrete derivative operators on summation-by-parts form and weak boundary and initial conditions. By mimicking the continuous analysis, the resulting semi-discrete as well as fully discrete scheme are shown to be provably stable, divergence free, and high-order accurate.

  • Lidström, Tina
    Linköpings universitet, Institutionen för beteendevetenskap och lärande, Pedagogik och sociologi.
    Lärares professionalism ur ett OECD-perspektiv: En kritisk diskursanalys om lärares professionalism2018Independent thesis Advanced level (degree of Master (One Year)), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Syftet med studien var att beskriva, analysera samt problematisera diskursen, med tillhörande kunskap, om lärares professionalism. Studien genomfördes med utgångspunkt i dokument från organisationen OECD.

    Med inspiration från Norman Faircloughs modell för kritisk diskursanalys studerades ett OECD-dokument och analyserades i relation till Faircloughs och Michel Foucaults teorier samt tidigare forskning. Studiens resultat visade att en konceptualisering av lärares professionalism framträder inom OECD-diskursen samt att kvalitet, professionalism som kollektiv angelägenhet och i synnerhet effektivitet är centrala teman. I detta uttrycks kvalitet och kollektiv professionalism vara medel för att uppnå målet effektivitet. Studiens resultat visade vidare att de diskurstyper som framträder är en konceptualiseringsdiskurs, en stöddiskurs, en kollektivitetsdiskurs, en kvalitetsdiskurs, en effektivitetsdiskurs samt en policydiskurs. I studien framgår även att lärares professionalism tillskrivs en särskild betydelse vilket medför skapandet av en viss kunskap inom OECD-diskursen. Denna kunskap förefaller ha sin utgångspunkt i ett särskilt sätt att se på lärares professionalism.

    Studien visade slutligen att insatser kring lärares professionalism uttrycks, av OECD, vara prioriterade för nationell policy. Inom ramen för detta skrivs lärares professionalism fram som ett fokus för policy i termer av att "lösningar" kring detta även uttrycks vara lösningar för ett utbildningssystem "i kris".

  • Disputas: 2018-12-18 10:15 Planck, Fysikhuset, Linköping
    Lilja, Louise
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Halvledarmaterial. Linköpings universitet, Tekniska fakulteten.
    4H-SiC epitaxy investigating carrier lifetime and substrate off-axis dependence2018Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Silicon carbide (SiC) is a wide bandgap semiconductor with unique material properties making it useful for various device applications using high power, high frequency and high temperature. Compared to Si-based electronics, SiC based electronics have an improved energy efficiency. One of the most critical problems is to reduce this planets power consumption, where large improvements can be made enhancing the energy efficiency. Independent on how the electrical power is generated, power conversion is needed and about 10% of the electrical power is lost for every power conversion step using Si-based electronics. Since the efficiency is related to the performance of the semiconductor device, SiC can make contributions to the efficiency. Compared to Si, SiC has three times larger bandgap, about ten times higher breakdown electric field strength and about three times higher thermal conductivity. The wide bandgap together with the chemical stability of SiC makes it possible for SiC electronic devices to operate at much higher temperatures (>250°C) compared to Si-based devices and do not require large cooling units as with Si power converters.

    The current status for 4H-SiC devices regard unipolar devices (≤ 1700 V), such as metal-oxide-semiconductor field-effect transistors (MOSFETs) and Schottky barrier diodes (SBDs), are now on the market for mass production. The research focus is now on high-voltage (>10 kV) bipolar devices, such as, bipolar junction transistors (BJTs), p‑i‑n diodes and insulated-gate bipolar transistors (IGBTs).

    The focus of this thesis are material improvements relevant for the development of 4H-SiC high-voltage bipolar devices. A key parameter for such devices is the minority carrier lifetime, where long carrier lifetimes reduce the on-resistance through conductivity modulation. However, too long carrier lifetimes give long reverse recovery times leading to large switching losses. Thus, a tailored carrier lifetime is needed for the specific application. Carrier lifetimes of the epilayers can both be controlled by the CVD growth conditions and by post-growth processing, such as thermal oxidation and carbon implantation followed by thermal annealing. Emphasis in this thesis (Paper 1‑2) is to find optimal CVD growth conditions (growth temperature, C/Si ratio, growth rate, doping) improving the carrier lifetime. Since the main lifetime limiting defect has shown to be the Z1/2 center, identified as isolated carbon vacancies, growth conditions minimizing the Z1/2 concentration are strived for.

    To achieve high-voltage bipolar devices, thick epilayers of high quality is needed. An important factor is then the growth rate that needs to be relatively high in order to reduce the fabrication time, and thus the cost of the final device. In this thesis the growth process has been optimized for high growth rates (30 µm/h) using standard silane and propane chemistry (Paper 3), compared to other chemistries that includes chlorine, which results in corroded reactor parts and new defects in the epitaxial layers.

    Another important parameter for 4H-SiC bipolar devices is the basal plane dislocations (BPDs) in the substrate and epilayers, since the BPDs can act as source of nucleation and expansion of Shockley stacking faults (SSFs). The expanded SSFs give a lowered carrier lifetime and form a potential barrier for carrier transport leading to an increased forward voltage drop which in turn leads to bipolar degradation. The bipolar degradation is detrimental for 4H-SiC bipolar devices. Several strategies are developed to reduce the density of BPDs including buffer layers, growth interrupts and decreasing the substrates off-cut angle. Paper 4‑6 is focused on developing a CVD growth process for low substrate off-cut angles (1° and 2°) compared to the today’s standard off-cut angle of 4°. By reducing the substrate off-cut angle the number of BPDs intersecting the substrate surface is reduced. In addition, the conversion from BPDs to threading edge dislocations (TEDs) during epitaxial growth is increased with lower off-cut angles.

    Delarbeid
    1. Influence of Growth Temperature on Carrier Lifetime in 4H-SiC Epilayers
    Åpne denne publikasjonen i ny fane eller vindu >>Influence of Growth Temperature on Carrier Lifetime in 4H-SiC Epilayers
    Vise andre…
    2013 (engelsk)Konferansepaper, Publicerat paper (Fagfellevurdert)
    Abstract [en]

    Carrier lifetime and formation of defects have been investigated as a function of growth temperature in n-type 4H-SiC epitaxial layers, grown by horizontal hot-wall CVD. Emphasis has been put on having fixed conditions except for the growth temperature, hence growth rate, doping and epilayer thickness were constant in all epilayers independent of growth temperature. An increasing growth temperature gave higher Z1/2 concentrations along with decreasing carrier lifetime. A correlation between growth temperature and D1 defect was also observed.

    sted, utgiver, år, opplag, sider
    Trans Tech Publications Inc., 2013
    Emneord
    Atomic Force Microscopy, Carrier Lifetime, DLTS, Epitaxial Growth, Horizontal Hot-Wall CVD, Intrinsic Defect, Photoluminescence (PL)
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-88341 (URN)10.4028/www.scientific.net/MSF.740-742.637 (DOI)000319785500151 ()
    Konferanse
    9th European Conference on Silicon Carbide and Related Materials (ECSCRM 2012), 2-6 September 2012, St Petersburg, Russia
    Tilgjengelig fra: 2013-02-04 Laget: 2013-02-04 Sist oppdatert: 2018-12-10
    2. Smooth 4H-SiC epilayers grown with high growth rates with silane/propane chemistry using 4° off-cut substrates
    Åpne denne publikasjonen i ny fane eller vindu >>Smooth 4H-SiC epilayers grown with high growth rates with silane/propane chemistry using 4° off-cut substrates
    2016 (engelsk)Inngår i: Silicon Carbide and Related Materials 2015 / [ed] Fabrizio Roccaforte, Francesco La Via, Roberta Nipoti, Danilo Crippa, Filippo Giannazzo and Mario Saggio, Trans Tech Publications, 2016, Vol. 858, s. 209-212Konferansepaper, Publicerat paper (Fagfellevurdert)
    Abstract [en]

    4H-SiC epilayers with very smooth surfaces were grown with high growth rates on 4° off-cut substrates using standard silane/propane chemistry. Specular surfaces with RMS values below 0.2 nm are presented for epilayers grown with growth rates up to 30 μm/h using horizontal hot-wall chemical vapor deposition, with up to 100 μm thickness. Optimization of in-situ etching conditions and C/Si ratio are presented.

    sted, utgiver, år, opplag, sider
    Trans Tech Publications, 2016
    Serie
    Materials Science Forum, ISSN 1662-9752 ; 858
    Emneord
    Atomic force microscopy, Chemical vapor deposition, Epitaxial growth, Silicon carbide
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-153288 (URN)10.4028/www.scientific.net/MSF.858.209 (DOI)
    Konferanse
    The 16th International Conference on Silicon Carbide and Related Materials (ICSCRM2015), Giardini Naxos, Sicily, Italy, October 4th October 9th, 2015.
    Tilgjengelig fra: 2018-12-10 Laget: 2018-12-10 Sist oppdatert: 2018-12-10
    3. Improved Epilayer Surface Morphology on 2 degrees off-cut 4H-SiC Substrates
    Åpne denne publikasjonen i ny fane eller vindu >>Improved Epilayer Surface Morphology on 2 degrees off-cut 4H-SiC Substrates
    2014 (engelsk)Inngår i: SILICON CARBIDE AND RELATED MATERIALS 2013, PTS 1 AND 2, Trans Tech Publications , 2014, Vol. 778-780, s. 206-209Konferansepaper, Publicerat paper (Fagfellevurdert)
    Abstract [en]

    Homoepitaxial layers of 4H-SiC were grown with horizontal hot-wall CVD on 2 degrees off-cut substrates, with the purpose of improving the surface morphology of the epilayers and reducing the density of surface morphological defects. In-situ etching conditions in either pure hydrogen or in a mixture of silane and hydrogen prior to the growth were compared as well as C/Si ratios in the range 0.8 to 1.0 during growth. The smoothest epilayer surface, together with lowest defect density, was achieved with growth at a C/Si ratio of 0.9 after an in-situ etching in pure hydrogen atmosphere.

    sted, utgiver, år, opplag, sider
    Trans Tech Publications, 2014
    Serie
    Materials Science Forum, ISSN 1662-9752 ; 778-780
    Emneord
    epitaxial growth; horizontal hot-wall CVD; atomic force microscopy; vicinal off angle
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-108194 (URN)10.4028/www.scientific.net/MSF.778-780.206 (DOI)000336634100048 ()
    Konferanse
    SILICON CARBIDE AND RELATED MATERIALS 2013
    Tilgjengelig fra: 2014-06-26 Laget: 2014-06-26 Sist oppdatert: 2018-12-10
    4. In-grown stacking-faults in 4H-SiC epilayers grown on 2 degrees off-cut substrates
    Åpne denne publikasjonen i ny fane eller vindu >>In-grown stacking-faults in 4H-SiC epilayers grown on 2 degrees off-cut substrates
    2015 (engelsk)Inngår i: Physica status solidi. B, Basic research, ISSN 0370-1972, E-ISSN 1521-3951, Vol. 252, nr 6, s. 1319-1324Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    4H-SiC epilayers were grown on 2 degrees off-cut substrates using standard silane/propane chemistry, with the aim of characterizing in-grown stacking faults. The stacking faults were analyzed with low temperature photoluminescence spectroscopy, room temperature photoluminescence mappings, room temperature cathodoluminescence and synchrotron white beam X-ray topography. At least three different types of in-grown stacking faults were observed, including double Shockley stacking faults, triple Shockley stacking faults and bar-shaped stacking faults. Those stacking faults are all previously found in 4 degrees and 8 degrees off-cut epilayers; however, the geometrical size is larger in epilayers grown on 2 degrees off-cut substrates due to lower off-cut angle. The stacking faults were formed close to the epilayer/substrate interface during the epitaxial growth. (C) 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim

    sted, utgiver, år, opplag, sider
    WILEY-V C H VERLAG GMBH, 2015
    Emneord
    chemical vapor deposition; epitaxy; photoluminescence; SiC; stacking faults
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-120065 (URN)10.1002/pssb.201451710 (DOI)000355756200018 ()
    Merknad

    Funding Agencies|Swedish Research Council (VR); Advanced Functional Materials (AFM); Swedish Foundation for Strategic Research (SSF)

    Tilgjengelig fra: 2015-07-06 Laget: 2015-07-06 Sist oppdatert: 2018-12-10
  • Constantin, Robert
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Produktionsekonomi.
    Gerzic, Denis
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Produktionsekonomi.
    An Evaluation of Swedish Municipal Borrowing via Nikkei-linked Loans2018Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    In this master thesis, we compare three different types of funding alternatives from a Swedish municipality's point of view, with the main focus on analysing a Nikkei-linked loan. We do this by analysing the resulting interest rate and the expected exposures, taking collateral into consideration.

    We conclude, with certainty, that there are many alternatives for funding and that they each need to be analysed and compared on many levels to be able to make a correct decision as to which ones to choose. An important part of this is to consider the implications of the newest regulations and risk exposure, as it might greatly influence the final price for contracts.

    Between the cases that we considered, the SEK bond was the one with the lowest resulting spread, and the one which is the simplest considering the collateral involved. While other alternatives might be better depending on how profitable it is for the municipality to receive collateral, the SEK bond is the most transparent one and with least risk involved.

  • Disputas: 2018-12-19 13:15 Nobel BL32, B-Huset, Linköping
    Maghazeh, Arian
    Linköpings universitet, Institutionen för datavetenskap, Programvara och system. Linköpings universitet, Tekniska fakulteten.
    System-Level Design of GPU-Based Embedded Systems2018Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Modern embedded systems deploy several hardware accelerators, in a heterogeneous manner, to deliver high-performance computing. Among such devices, graphics processing units (GPUs) have earned a prominent position by virtue of their immense computing power. However, a system design that relies on sheer throughput of GPUs is often incapable of satisfying the strict power- and time-related constraints faced by the embedded systems.

    This thesis presents several system-level software techniques to optimize the design of GPU-based embedded systems under various graphics and non-graphics applications. As compared to the conventional application-level optimizations, the system-wide view of our proposed techniques brings about several advantages: First, it allows for fully incorporating the limitations and requirements of the various system parts in the design process. Second, it can unveil optimization opportunities through exposing the information flow between the processing components. Third, the techniques are generally applicable to a wide range of applications with similar characteristics. In addition, multiple system-level techniques can be combined together or with application-level techniques to further improve the performance.

    We begin by studying some of the unique attributes of GPU-based embedded systems and discussing several factors that distinguish the design of these systems from that of the conventional high-end GPU-based systems. We then proceed to develop two techniques that address an important challenge in the design of GPU-based embedded systems from different perspectives. The challenge arises from the fact that GPUs require a large amount of workload to be present at runtime in order to deliver a high throughput. However, for some embedded applications, collecting large batches of input data requires an unacceptable waiting time, prompting a trade-off between throughput and latency. We also develop an optimization technique for GPU-based applications to address the memory bottleneck issue by utilizing the GPU L2 cache to shorten data access time. Moreover, in the area of graphics applications, and in particular with a focus on mobile games, we propose a power management scheme to reduce the GPU power consumption by dynamically adjusting the display resolution, while considering the user's visual perception at various resolutions. We also discuss the collective impact of the proposed techniques in tackling the design challenges of emerging complex systems.

    The proposed techniques are assessed by real-life experimentations on GPU-based hardware platforms, which demonstrate the superior performance of our approaches as compared to the state-of-the-art techniques.

    Delarbeid
    1. General Purpose Computing on Low-Power Embedded GPUs: Has It Come of Age?
    Åpne denne publikasjonen i ny fane eller vindu >>General Purpose Computing on Low-Power Embedded GPUs: Has It Come of Age?
    2013 (engelsk)Inngår i: 13th International Conference on Embedded Computer Systems: Architectures, Modeling, and Simulation (SAMOS 2013), Samos, Greece, July 15-18, 2013., IEEE Press, 2013Konferansepaper, Publicerat paper (Fagfellevurdert)
    Abstract [en]

    In this paper we evaluate the promise held by low power GPUs for non-graphic workloads that arise in embedded systems. Towards this, we map and implement 5 benchmarks, that find utility in very different application domains, to an embedded GPU. Our results show that apart from accelerated performance, embedded GPUs are promising also because of their energy efficiency which is an important design goal for battery-driven mobile devices. We show that adopting the same optimization strategies as those used for programming high-end GPUs might lead to worse performance on embedded GPUs. This is due to restricted features of embedded GPUs, such as, limited or no user-defined memory, small instruction-set, limited number of registers, among others. We propose techniques to overcome such challenges, e.g., by distributing the workload between GPUs and multi-core CPUs, similar to the spirit of heterogeneous computation.

    sted, utgiver, år, opplag, sider
    IEEE Press, 2013
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-92626 (URN)10.1109/SAMOS.2013.6621099 (DOI)000332458100004 ()
    Konferanse
    SAMOS'13
    Tilgjengelig fra: 2013-05-14 Laget: 2013-05-14 Sist oppdatert: 2018-12-07
    2. Saving Energy without Defying Deadlines on Mobile GPU-based Heterogeneous Systems
    Åpne denne publikasjonen i ny fane eller vindu >>Saving Energy without Defying Deadlines on Mobile GPU-based Heterogeneous Systems
    Vise andre…
    2014 (engelsk)Inngår i: 2014 International Conference on Hardware/Software Codesign and System Synthesis, Association for Computing Machinery (ACM), 2014Konferansepaper, Publicerat paper (Fagfellevurdert)
    Abstract [en]

    With the advent of low-power programmable compute cores based on GPUs, GPU-equipped heterogeneous platforms are becoming common in a wide spectrum of industries including safety-critical domains like the automotive industry. While the suitability of GPUs for throughput oriented applications is well-accepted, their applicability for real-time applications remains an open issue. Moreover, in mobile/embedded systems, energy-efficient computing is a major concern and yet, there has been no systematic study on the energy savings that GPUs may potentially provide. In this paper, we propose an approach to utilize both the GPU and the CPU in a heterogeneous fashion to meet the deadlines of a real-time application while ensuring that we maximize the energy savings. We note that GPUs are inherently built to maximize the throughput and this poses a major challenge when deadlines must be satisfied. The problem becomes more acute when we consider the fact that GPUs are more energy efficient than CPUs and thus, a naive approach that is based on maximizing GPU utilization might easily lead to infeasible solutions from a deadline perspective.

    sted, utgiver, år, opplag, sider
    Association for Computing Machinery (ACM), 2014
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-112689 (URN)10.1145/2656075.2656097 (DOI)978-1-4503-3051-0 (ISBN)
    Konferanse
    International Conference on Hardware/Software Codesign and System Synthesis (CODES+ISSS 2014), New Delhi, India, October 12-17, 2014
    Tilgjengelig fra: 2014-12-08 Laget: 2014-12-08 Sist oppdatert: 2018-12-07bibliografisk kontrollert
    3. Perception-aware power management for mobile games via dynamic resolution scaling
    Åpne denne publikasjonen i ny fane eller vindu >>Perception-aware power management for mobile games via dynamic resolution scaling
    Vise andre…
    2015 (engelsk)Inngår i: 2015 IEEE/ACM INTERNATIONAL CONFERENCE ON COMPUTER-AIDED DESIGN (ICCAD), IEEE , 2015, s. 613-620Konferansepaper, Publicerat paper (Fagfellevurdert)
    Abstract [en]

    Modern mobile devices provide ultra-high resolutions in their display panels. This imposes ever increasing workload on the GPU leading to high power consumption and shortened battery life. In this paper, we first show that resolution scaling leads to significant power savings. Second, we propose a perception-aware adaptive scheme that sets the resolution during game play. We exploit the fact that game players are often willing to trade quality for longer battery life. Our scheme uses decision theory, where the predicted user perception is combined with a novel asymmetric loss function that encodes users' alterations in their willingness to save power.

    sted, utgiver, år, opplag, sider
    IEEE, 2015
    Serie
    ICCAD-IEEE ACM International Conference on Computer-Aided Design, ISSN 1933-7760
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-124543 (URN)10.1109/ICCAD.2015.7372626 (DOI)000368929600084 ()978-1-4673-8388-2 (ISBN)
    Konferanse
    Computer-Aided Design (ICCAD), 2015 IEEE/ACM International Conference on 2-6 Nov. 2015 Austin, TX
    Tilgjengelig fra: 2016-02-02 Laget: 2016-02-02 Sist oppdatert: 2018-12-07
    4. Latency-Aware Packet Processing on CPU-GPU Heterogeneous Systems
    Åpne denne publikasjonen i ny fane eller vindu >>Latency-Aware Packet Processing on CPU-GPU Heterogeneous Systems
    Vise andre…
    2017 (engelsk)Inngår i: DAC '17 Proceedings of the 54th Annual Design Automation Conference 2017, New York, NY, USA: Association for Computing Machinery (ACM), 2017Konferansepaper, Publicerat paper (Fagfellevurdert)
    Abstract [en]

    In response to the tremendous growth of the Internet, towards what we call the Internet of Things (IoT), there is a need to move from costly, high-time-to-market specific-purpose hardware to flexible, low-time-to-market general-purpose devices for packet processing. Among several such devices, GPUs have attracted attention in the past, mainly because the high computing demand of packet processing applications can, potentially, be satisfied by these throughput-oriented machines. However, another important aspect of such applications is the packet latency which, if not handled carefully, will overshadow the throughput benefits. Unfortunately, until now, this aspect has been mostly ignored. To address this issue, we propose a method that considers the variable bit rate of the traffic and, depending on the current rate, minimizes the latency, while meeting the rate demand. We propose a persistent kernel based software architecture to overcome the challenges inherent in GPU implementation like kernel invocation overhead, CPU-GPU communication and memory access overhead. We have chosen packet classification as the packet processing application to demonstrate our technique. Using the proposed approach, we are able to reduce the packet latency on average by a factor of 3.5, compared to the state-of-the-art solutions, without any packet drop.

    sted, utgiver, år, opplag, sider
    New York, NY, USA: Association for Computing Machinery (ACM), 2017
    Serie
    Design Automation Conference DAC, ISSN 0738-100X
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-141212 (URN)10.1145/3061639.3062269 (DOI)000424895400129 ()2-s2.0-85023612665 (Scopus ID)978-1-4503-4927-7 (ISBN)
    Konferanse
    54th ACM/EDAC/IEEE Design Automation Conference (DAC), Austin, TX, USA, June 18-22, 2017
    Tilgjengelig fra: 2017-09-27 Laget: 2017-09-27 Sist oppdatert: 2018-12-07bibliografisk kontrollert
  • Ali, Zaheer
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för kardiovaskulär medicin. Linköpings universitet, Medicinska fakulteten.
    Investigating mechanisms of angiogenesis in health and disease using zebrafish models2018Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Angiogenesis, the growth of blood vessels from an existing vasculature, can occur by sprouting from preexisting vessels or by vessel splitting (intussusception). Pathological angiogenesis drives choroidal neovascularization (CNV) in age related macular degeneration (AMD) which is commonly restricted under the retinal pigment epithelium (RPE), called occult CNV, but may also involve vessels penetrating through the RPE into the sub-retinal space. Pathological vessels are poorly developed, insufficiently perfused and highly leaky, phenotypes that are considered to drive disease progression and lead to poor prognosis. Currently, a number of anti-angiogenic drugs exists, the majority of which target vascular endothelial factor (VEGF), but although they often are highly beneficial for treating eye diseases in the short-term, they are generally of limited efficacy in other diseases such as cancer, and also have poorer efficacy when used for treatment of eye diseases in the long-term. A better understanding of the mechanisms underlying pathological angiogenesis can generate new targets for treatment leading to development of better drugs for cancer and retinopathies, but perhaps also other angiogenesis-dependent diseases, in the future. In this thesis mechanisms involved in developmental angiogenesis or pathological angiogenesis in the choroid, cornea or melanoma was identified. These findings highlight the need to further elaborate our knowledge related to angiogenesis in different tissues/conditions for a more targeted, and potentially effective treatment of diseases in the future.

    In paper I, we for the first time identified the choriocapillaries (CCs) in adult zebrafish and found that occult CNV could be induced by exposing the fish to severe hypoxia. Interestingly, we found that occult CNV relied on intussusception, involving not only de novo generation of intussusceptive pillars but also a previously poorly understood mechanism called pillar splitting. This involved HIF-VEGF-VEGFR2 signaling and evidence that this also occurred in both rats and humans suffering from AMD suggested that the mechanism was conserved and clinically relevant.

    In contrast, we found in paper II that the development of CCs in the zebrafish relies on sprouting angiogenesis, involve continuous remodeling, and delayed maturation of the vasculature in 2D. The initial development was found to occur by a unique process of tissuewide synchronized vasculogenesis. As expected, VEGFA via VEGFR2 was also critical for the development of these vessels in the zebrafish embryo, but surprisingly this was independent on hypoxia-inducible factor (HIF)-1.

    Inflammatory nuclear factor-kB (NF-kB) signaling is involved in the progression of angiogenesis, but this signaling pathway has mainly been studied in the inflammatory cells and the role of NF-kB in the endothelial cells during angiogenesis is poorly understood. In paper III, we found that blocking NF-kB signaling using a specific IKK2 blocker IMD0354, specifically blocks pathological as well as developmental angiogenesis by targeting endothelial cell NF-kB signaling in the endothelial cells. Using a rat model for suture-induced corneal neovascularization, IMD0354 treatment lead to reduced production of inflammatory C-C motif chemokine ligand 2 (CCL2), C-X-C motif chemokine ligand 5 (CXCL5) and VEGF, and thereby reduced pathological corneal angiogenesis in this model.

    Using the zebrafish tumor xenograft model in paper IV, we found an association between Microphthalmia associated transcription factor (MITF) and pigment epithelium derived factor (PEDF), which was involved in pathological tumor angiogenesis and metastasis. Similarly, in paper V we used zebrafish transplantation models to study and investigate the use of biocompatible polymers for the delivery of pro-angiogenic FGF-2 as a potential treatment strategy for ischemic diseases such as myocardial infarction (MI). Conclusively, this thesis provides new insights into diverse fields of angiogenic assays using zebrafish, and reveals new mechanisms of angiogenesis in health and disease. This work will hopefully provide a foundation for further studies into occult CNV related to AMD, a process that has not been possible to study previously in pre-clinical models. In addition, zebrafish xenograft or other transplantation models used in this work will likely be important to study cancer biology and to develop more attractive pharmaceutical preparations based on biocompatible hydrogels formulated as microspheres in the future.

    Delarbeid
    1. Selective IKK2 inhibitor IMD0354 disrupts NF-kappa B signaling to suppress corneal inflammation and angiogenesis
    Åpne denne publikasjonen i ny fane eller vindu >>Selective IKK2 inhibitor IMD0354 disrupts NF-kappa B signaling to suppress corneal inflammation and angiogenesis
    Vise andre…
    2018 (engelsk)Inngår i: Angiogenesis, ISSN 0969-6970, E-ISSN 1573-7209, Vol. 21, nr 2, s. 267-285Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Corneal neovascularization is a sight-threatening condition caused by angiogenesis in the normally avascular cornea. Neovascularization of the cornea is often associated with an inflammatory response, thus targeting VEGF-A alone yields only a limited efficacy. The NF-kappa B signaling pathway plays important roles in inflammation and angiogenesis. Here, we study consequences of the inhibition of NF-kappa B activation through selective blockade of the IKK complex I kappa B kinase beta (IKK2) using the compound IMD0354, focusing on the effects of inflammation and pathological angiogenesis in the cornea. In vitro, IMD0354 treatment diminished HUVEC migration and tube formation without an increase in cell death and arrested rat aortic ring sprouting. In HUVEC, the IMD0354 treatment caused a dose-dependent reduction in VEGF-A expression, suppressed TNF alpha-stimulated expression of chemokines CCL2 and CXCL5, and diminished actin filament fibers and cell filopodia formation. In developing zebrafish embryos, IMD0354 treatment reduced expression of Vegf-a and disrupted retinal angiogenesis. In inflammation-induced angiogenesis in the rat cornea, systemic selective IKK2 inhibition decreased inflammatory cell invasion, suppressed CCL2, CXCL5, Cxcr2, and TNF-alpha expression and exhibited anti-angiogenic effects such as reduced limbal vessel dilation, reduced VEGF-A expression and reduced angiogenic sprouting, without noticeable toxic effect. In summary, targeting NF-kappa B by selective IKK2 inhibition dampened the inflammatory and angiogenic responses in vivo by modulating the endothelial cell expression profile and motility, thus indicating an important role of NF-kappa B signaling in the development of pathologic corneal neovascularization.

    sted, utgiver, år, opplag, sider
    Springer Netherlands, 2018
    Emneord
    Cornea; Neovascularization; NF-kappa B; IMD0354; IKK2; VEGF
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-147373 (URN)10.1007/s10456-018-9594-9 (DOI)000428924500007 ()29332242 (PubMedID)2-s2.0-85041334437 (Scopus ID)
    Merknad

    Funding Agencies|Swedish Research Council [2012-2472]; Swedish Foundation Stiftelsen Synframjandets Forskningsfond/Ogonfonden; Svenska Sallskapet for Medicinsk Forskning; Linkoping Universitet; Jeanssons Stiftelser

    Tilgjengelig fra: 2018-05-18 Laget: 2018-05-18 Sist oppdatert: 2018-12-07bibliografisk kontrollert
    2. Regulatory and Functional Connection of Microphthalmia-Associated Transcription Factor and Anti-Metastatic Pigment Epithelium Derived Factor in Melanoma
    Åpne denne publikasjonen i ny fane eller vindu >>Regulatory and Functional Connection of Microphthalmia-Associated Transcription Factor and Anti-Metastatic Pigment Epithelium Derived Factor in Melanoma
    Vise andre…
    2014 (engelsk)Inngår i: Neoplasia, ISSN 1522-8002, E-ISSN 1476-5586, Vol. 16, nr 6, s. 529-542Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Pigment epithelium-derived factor (PEDF), a member of the serine protease inhibitor superfamily, has potent anti-metastatic effects in cutaneous melanoma through its direct actions on endothelial and melanoma cells. Here we show that PEDF expression positively correlates with microphthalmia-associated transcription factor ( MITF) in melanoma cell lines and human samples. High PEDF and MITF expression is characteristic of low aggressive melanomas classified according to molecular and pathological criteria, whereas both factors are decreased in senescent melanocytes and naevi. Importantly, MITF silencing down-regulates PEDF expression in melanoma cell lines and primary melanocytes, suggesting that the correlation in the expression reflects a causal relationship. In agreement, analysis of Chromatin immunoprecipitation coupled to high throughput sequencing (ChIP-seq) data sets revealed three MITF binding regions within the first intron of SERPINF1, and reporter assays demonstrated that the binding of MITF to these regions is sufficient to drive transcription. Finally, we demonstrate that exogenous PEDF expression efficiently halts in vitro migration and invasion, as well as in vivo dissemination of melanoma cells induced by MITF silencing. In summary, these results identify PEDF as a novel transcriptional target of MITF and support a relevant functional role for the MITF-PEDF axis in the biology of melanoma.

    sted, utgiver, år, opplag, sider
    Neoplasia, 2014
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-110497 (URN)10.1016/j.neo.2014.06.001 (DOI)000340553600007 ()25030625 (PubMedID)
    Merknad

    Funding Agencies|Ministerio de Ciencia y Competitividad of Spain [SAF-2010-19256, SAF-2011-24225, SAF-2012-32117, FIS 11/02568, RD09/0076/0101, PT13/0010/0012, PI12/01552]; LiU-Cancer; Svenska Sallskapet for Medicinsk Forskning; Ake Wibergs Stiftelse; Goesta Fraenkels Stifelse; Fundacion Cientifica de la Asociacion Espanola Contra el Cancer

    Tilgjengelig fra: 2014-09-15 Laget: 2014-09-12 Sist oppdatert: 2018-12-07
    3. Adjustable delivery of pro-angiogenic FGF-2 by alginate: collagen microspheres
    Åpne denne publikasjonen i ny fane eller vindu >>Adjustable delivery of pro-angiogenic FGF-2 by alginate: collagen microspheres
    Vise andre…
    2018 (engelsk)Inngår i: BIOLOGY OPEN, ISSN 2046-6390, Vol. 7, nr 3, artikkel-id UNSP bio027060Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Therapeutic induction of blood vessel growth (angiogenesis) in ischemic tissues holds great potential for treatment of myocardial infarction and stroke. Achieving sustained angiogenesis and vascular maturation has, however, been highly challenging. Here, we demonstrate that alginate: collagen hydrogels containing therapeutic, pro-angiogenic FGF-2, and formulated as microspheres, is a promising and clinically relevant vehicle for therapeutic angiogenesis. By titrating the amount of readily dissolvable and degradable collagen with more slowly degradable alginate in the hydrogel mixture, the degradation rates of the biomaterial controlling the release kinetics of embedded proangiogenic FGF-2 can be adjusted. Furthermore, we elaborate a microsphere synthesis protocol allowing accurate control over sphere size, also a critical determinant of degradation/release rate. As expected, alginate: collagen microspheres were completely biocompatible and did not cause any adverse reactions when injected in mice. Importantly, the amount of pro-angiogenic FGF-2 released from such microspheres led to robust induction of angiogenesis in zebrafish embryos similar to that achieved by injecting FGF-2-releasing cells. These findings highlight the use of microspheres constructed from alginate: collagen hydrogels as a promising and clinically relevant delivery system for pro-angiogenic therapy.

    sted, utgiver, år, opplag, sider
    COMPANY OF BIOLOGISTS LTD, 2018
    Emneord
    Hydrogels; Microspheres; Angiogenesis; Vasculature; Zebrafish
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-147419 (URN)10.1242/bio.027060 (DOI)000429100500002 ()29449216 (PubMedID)
    Merknad

    Funding Agencies|Svenska Sallskapet for Medicinsk Forskning; Ake-Wiberg Foundation; Goesta Fraenkel Foundation; Ahrens Stiftelse; Ollie och Elof Ericssons Stiftelse; Carmen och Bertil Ragners Stiftelse; KI Stiftelser och fonder; Loo och Hans Ostermans Stiftelse for Medicinsk Forskning; Vetenskapsradet; Linkoping University

    Tilgjengelig fra: 2018-05-17 Laget: 2018-05-17 Sist oppdatert: 2018-12-07
  • Granath, Lovisa
    et al.
    Linköpings universitet, Institutionen för samhälls- och välfärdsstudier, Socialt arbete.
    Sandström, Maria
    Linköpings universitet, Institutionen för samhälls- och välfärdsstudier, Socialt arbete.
    ‘Where do you draw the line?’: A study about how South African social workers understand their professional role when working with caregivers who use child corporal punishment.2018Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    Globally, there is an ongoing debate whether child corporal punishment should be banned or not in the home environment. While several countries have banned it already, South Africa is currently in a process of change. Research indicates that child corporal punishment is commonly used in South Africa and that social workers opinions on child corporal punishment seems to be formed by their personal experiences, which affects their assessments. Furthermore, according to research legal reforms are not enough to change a society’s attitudes and norms about child corporal punishment. There is a need of campaigns and leadership.

    The aim of this study was to comprehend how eight South African social workers described that they understood their professional role, when they worked with caregivers who used child corporal punishment. The informants worked, at the time of the interviews, at different workplaces in Cape Town and had experiences in their professional role of meeting caregivers who used child corporal punishment. Social constructionism was used as the theory of science. The study uses theories by Burr, Gergen and Gergen and Foucault to analyse the impacts of language and discourse in the social workers’ understandings.

    The empirical material was analysed with qualitative content analysis. We found four themes where all except the first one, are divided into two sub-themes. The first theme is ‘How could corporal punishment be defined?’. Followed by ‘Opinions about corporal punishment’ with the sub-themes: ‘We need one standard to protect our children’ and ‘Corporal punishment should be allowed if it is not abusive’. ‘The roles of the social worker’ is the third theme, divided into the two sub-themes: ‘Social workers and the law’ and ‘The opportunity to make a change’. The last theme is Challenges the social worker face, divided into the sub-themes ‘Corporal punishment rooted in a violent society’ and ‘Corporal punishment in a cultural society’.

    The results of the study indicate that most of the social workers understood their role, when they worked with caregivers who use child corporal punishment, was to educate by presenting other alternatives than corporal punishment. However, when exploring definitions, opinions, challenges and abilities they sometimes had quite different understandings to one another. Child corporal punishment would be defined both as equivalent as well as separated from abuse, creating confusion to where a line should be drawn. The caregivers’ rights to use corporal punishment would be compared to the children’s rights to be protected from it. Laws regarding child corporal punishment was both present and nonexistent in described assessments. The social workers action space varied greatly. They expressed the need to balance different aspects in the assessment and decide where to draw the line between them. Most of the informants, understood themselves as powerful to bring about change concerning the use of child corporal punishment in the specific families. However, they highlighted the challenges with South Africa’s history and general accepting of child corporal punishment.

  • Gunnarsson, Emelie
    et al.
    Linköpings universitet, Institutionen för samhälls- och välfärdsstudier, Socialt arbete.
    Waller, Sara
    Linköpings universitet, Institutionen för samhälls- och välfärdsstudier, Socialt arbete.
    "Jag vill berätta att man klarar sig, fastän att man faller tusen meter i sorg": En narrativ studie om anhörigas upplevelser av att förlora en närstående i suicid2018Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Syftet med denna studie är att ur ett narrativt perspektiv belysa anhörigas upplevelser av att förlora en närstående i suicid. Studien bygger på 12 berättelser från anhöriga som publicerats i en podcast. Utifrån Goffmans teori om stigma, Castelli Dransarts teori om sorgeprocessen och Clausens teori om vändpunkter kan studien fördjupa förståelsen för de anhörigas upplevelser av att förlora en närstående och hur de väljer att berätta om det i podcasten. Det empiriska materialet har analyserats genom en narrativ analys vilket resulterade i fem teman: livet förevändpunkter, suicidet, livet efter och sorgeprocessen.

    Genom att applicera teori och tidigare forskning på dessa fem teman har vi i resultat- och analysdelen samt i diskussionen kunnat besvara studiens fyra frågeställningar samt studiens syfte. Studien visar att hur själva handlingen gått till, hur tiden varit innan samt hur dödsbeskedet levererats har en inverkan på sorgeprocessen. Resonemang i diskussionen leder fram till att stöd till anhöriga är viktigt då de är en riskgrupp. Stöd behövs både i direkt anslutning till händelsen men också för de anhöriga som lever med någon som är suicidal. Det kan utifrån detta vara viktigt att involvera de anhöriga i vården. Berättandet framträder som en viktig del i de anhörigas sorgeprocess och bidrar till mer kunskap om suicid och hur processen ser ut. De anhöriga förmedlar kunskap till samhället genom sina berättelser i förhoppning om att de ska förändra samhällets bild av suicid och bemötandet av de drabbade.

  • Guinart Platero, David
    Linköpings universitet, Institutionen för systemteknik. Linköpings universitet, Tekniska fakulteten.
    Deterministic Analysis of the Accuracy in FFT Hardware Architectures2012Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    This Master Thesis studies the different quantization effects in hardware architecture due to the use of finite word lenght. This master thesis gives a deterministic analysis with relation to the accuracy and presents a relationship between input bits and coefficient bits for minimizing recourses and to obtained the best relation with the accuracy. Furthermore, the objective of this mater thesis is to find a direct relation between the input bits and coefficient bits. This can be used as guide for the design of FFT hardware architectures

  • Kozlov, Vladimir
    et al.
    Linköpings universitet, Matematiska institutionen, Matematik och tillämpad matematik. Linköpings universitet, Tekniska fakulteten.
    Orlof, Anna
    Linköpings universitet, Matematiska institutionen, Matematik och tillämpad matematik. Linköpings universitet, Tekniska fakulteten.
    Nazarov, Sergei
    Linköpings universitet, Matematiska institutionen, Matematik och tillämpad matematik. Linköpings universitet, Tekniska fakulteten.
    Trapped modes in armchair graphene nanoribbons2018Rapport (Annet vitenskapelig)
    Abstract [en]

    We study scattering on an ultra-low potential in armchair graphene nanorib bon. Using the continuous Dirac model and including a couple of articial waves in the scattering process, described by an augumented scattering matrix, we derive a condition for the existence of a trapped mode. We consider the threshold energies, where the the multiplicity of the continuous spectrum changes and show that a trapped mode may appear for energies slightly less than a thresold and its multiplicity does not exceed one. For energies which are higher than a threshold, there are no trapped modes, provided that the potential is suciently small.

  • Fältström, Anne
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för fysioterapi. Linköpings universitet, Medicinska fakulteten.
    Kvist, Joanna
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för fysioterapi. Linköpings universitet, Medicinska fakulteten. Division of Physiotherapy, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden.
    Gauffin, Håkan
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för Kirurgi, Ortopedi och Onkologi. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Centrum för kirurgi, ortopedi och cancervård, Ortopedkliniken i Linköping.
    Hägglund, Martin
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för fysioterapi. Linköpings universitet, Medicinska fakulteten. Football Research Group, Linköping University, Linköping, Sweden.
    Female Soccer Players With Anterior Cruciate Ligament Reconstruction Have a Higher Risk of New Knee Injuries and Quit Soccer to a Higher Degree Than Knee-Healthy Controls2018Inngår i: American Journal of Sports Medicine, ISSN 0363-5465, E-ISSN 1552-3365, s. 1-10Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background:

    Many patients with anterior cruciate ligament (ACL) reconstruction who return to sport suffer new ACL injuries or quit sports soon after returning.

    Purpose:

    To prospectively follow a cohort of female soccer players with primary unilateral ACL reconstruction and matched knee-healthy controls from the same soccer teams to compare (1) the rate of new traumatic and nontraumatic knee injuries and other injuries, (2) the proportion of players who quit soccer, and (3) player-reported activity level and satisfaction with activity level and knee function.

    Study Design:

    Cohort study; Level of evidence, 2.

    Methods:

    A total of 117 active female soccer players (mean ± SD age, 19.9 ± 2.5 years) 18.9 ± 8.7 months after ACL reconstruction and 119 knee-healthy female soccer players (19.5 ± 2.5 years) matched from the same teams were prospectively followed for 2 years for new knee injuries, other injuries, soccer playing level, activity level according to the Tegner Activity Scale, and satisfaction with activity level and knee function.

    Results:

    Players with ACL reconstruction had a higher rate of new ACL injuries (n = 29 vs 8; 19 vs 4 per 100 player years; rate ratio [RR], 4.82; 95% CI, 2.20-10.54; P < .001), other traumatic knee injuries (29 vs 16 per 100 player years; RR, 1.84; 95% CI, 1.16-2.93; P < .01), and nontraumatic knee injuries (33 vs 9 per 100 player years; RR, 3.62; 95% CI, 2.11-6.21; P < .001) as compared with controls. There was no difference in the rate of other (not knee) injuries (43 vs 48 per 100 player years; RR, 0.90; 95% CI, 0.65-1.23; P = .494). During the 2-year follow-up, 72 (62%) players with ACL reconstruction quit soccer, as opposed to 43 (36%) controls (P = .001). The median Tegner Activity Scale score decreased in both groups (P < .001) but more for the ACL-reconstructed group (P < .015).

    Conclusion:

    Female soccer players with ACL reconstruction had nearly a 5-fold-higher rate of new ACL injuries and a 2- to 4-fold-higher rate of other new knee injuries, quit soccer to a higher degree, and reduced their activity level to a greater extent as compared with knee-healthy controls.

  • Salomonsson, Leif
    Linköpings universitet, Institutionen för systemteknik, Elektroniska Kretsar och System.
    Low Latency Wireless Sensor and Actuator Networks: Analysis of LLDN and RT-WiFi2018Independent thesis Basic level (university diploma), 180 hpOppgave
    Abstract [en]

    In this bachelor thesis, low latency wireless sensor and actuator networks are studied.In particular IEEE 802.15.4e/LLDN and IEEE 802.11g/RT-WiFi protocols. It is in-vestigated if the protocols are suitable for being used in typical industrial automationenvironments with high update frequencies of around 100 Hz. The protocols are exam-ined on a low level to shed lights on the sources of latency and followed by an analysis ofa specific configuration. It is found that LLDN is limited by low transmission rate andRT-WiFi is limited by interference with itself and other appliances. They both work wellfor update frequencies around 100 Hz.

  • Imtiaz, Nasir
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Mekanisk värmeteori och strömningslära.
    CFD simulation of dip-lubricated single-stage gearboxes through coupling of multiphase flow and multiple body dynamics: an initial investigation2018Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Transmissions are an essential part of a vehicle powertrain. An optimally designed powertrain can result in energy savings, reduced environmental impact and increased comfort and reliability. Along with other components of the powertrain, efficiency is also a major concern in the design of transmissions. The churning power losses associated with the motion of gears through the oil represent a significant portion of the total power losses in a transmission and therefore need to be estimated. A lack of reliable empirical models for the prediction of these losses has led to the emergence of CFD (Computational Fluid Dynamics) as a means to (i) predict these losses and (ii) promote a deeper understanding of the physical phenomena responsible for theselosses in order to improve existing models.

    The commercial CFD solver STAR-CCM+ is used to investigate the oil distribution and the churning power losses inside two gearbox configurations namely an FZG (Technical Institute for the Study of Gears and Drive Mechanisms) gearbox and a planetary gearbox. A comparison of two motion handling techniques in STARCCM+ namely MRF (Moving Reference Frame) and RBM (Rigid Body Motion) models is made in terms of the accuracy of results and the computational requirements using the FZG gearbox. A sensitivity analysis on how the size of gap between the meshing gear teeth affects the flow and the computational requirements is also done using the FZG gearbox. Different modelling alternatives are investigated for the planetary gearbox and the best choices have been determined. The numerical simulations are solved in an unsteady framework where the VOF (Volume Of Fluid) multiphase model is used to track the interface between the immiscible phases. The overset meshing technique has been used to reconfigure the mesh at each time step.

    The results from the CFD simulations are presented and discussed in terms of the modelling choices made and their effect on the accuracy of the results. The MRF method is a cheaper alternative compared to the RBM model however, the former model does not accurately simulate the transient start-up and instead provides just a regime solution of the unsteady problem. As expected, the accuracy of the results suffers from having a large gap between the meshing gear teeth. The use of compressible ideal gas model for the air phase with a pressure boundary condition gives the optimum performance for the planetary gearbox. The outcomes can be used toeffectively study transmission flows using CFD and thereby improve the design of future transmissions for improved efficiency.

  • Nilsson, Alexander
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Maskinkonstruktion.
    Thönners, Martin
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Maskinkonstruktion.
    A Framework for Generative Product Design Powered by Deep Learning and Artificial Intelligence: Applied on Everyday Products2018Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    In this master’s thesis we explore the idea of using artificial intelligence in the product design process and seek to develop a conceptual framework for how it can be incorporated to make user customized products more accessible and affordable for everyone.

    We show how generative deep learning models such as Variational Auto Encoders and Generative Adversarial Networks can be implemented to generate design variations of windows and clarify the general implementation process along with insights from recent research in the field.

    The proposed framework consists of three parts: (1) A morphological matrix connecting several identified possibilities of implementation to specific parts of the product design process. (2) A general step-by-step process on how to incorporate generative deep learning. (3) A description of common challenges, strategies andsolutions related to the implementation process. Together with the framework we also provide a system for automatic gathering and cleaning of image data as well as a dataset containing 4564 images of windows in a front view perspective.

  • Henriksson, Martin
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för hälso- och sjukvårdsanalys. Linköpings universitet, Medicinska fakulteten. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV.
    Siverskog, Jonathan
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för hälso- och sjukvårdsanalys. Linköpings universitet, Medicinska fakulteten.
    Johannesen, Kasper
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för hälso- och sjukvårdsanalys. Linköpings universitet, Medicinska fakulteten.
    Eriksson, Thérèse
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för hälso- och sjukvårdsanalys. Linköpings universitet, Medicinska fakulteten.
    Tröskelvärden och kostnadseffektivitet: innebörd och implikationer för ekonomiska utvärderingar och beslutsfattande i hälso- och sjukvården2018Rapport (Annet vitenskapelig)
    Abstract [sv]

    Resultaten från hälsoekonomiska utvärderingar redovisas oftast som en inkrementell kostnadseffektivitetskvot (ICER efter engelskans incremental cost-efectiveness ratio) vilken anger kostnaden per uppnådd effektenhet för den åtgärd som utvärderas. En åtgärd kan vara ett preventionsprogram, en diagnostisk metod eller en behandling i form av ett kirurgiskt ingrepp eller ett läkemedel (vi använder fortsättningsvis begreppet interventioner som ett samlingsnamn för alla dessa åtgärder). Vanligtvis används ett hälsorelaterat mått såsom kvalitetsjusterade levnadsår (QALYs) som effektmått. För att en ICER på ett meningsfullt sätt skall kunna tolkas och tillämpas i beslutsfattande krävs att vi har en uppfattning om vad resultaten representerar och vad de kan jämföras med. Inte sällan anges ett gräns-värde för när en intervention kan anses vara kostnadseffektiv i litteraturen, ett så kallat tröskelvärde för kostnadseffektivitet. Ambitiösa försök att skatta detta värde har nyligen presenterats och bidrar med ny kunskap på området. I ljuset av denna forskning är det också tydligt att det finns olika tolkningar av tröskelvärdet, vilket kan bidra till otydlighet i både beslutsfattande och diskussioner om vad som kan anses vara en rimlig gräns för kostnadseffektivitet. Syftet med föreliggande rapport är att beskriva olika tolkningar av tröskelvärdet, sammanfatta vilken empirisk kunskap vi har om detta värde idag och slutligen diskutera vidare forskning i en svensk kontext.

    I rapporten illustreras de två huvudsakliga definitionerna av tröskelvärde som återfinns i litteraturen.

    Konsumtionsvärdet av hälsa kan tänkas representera vad individer på marginalen är villiga att ge upp i konsumtion för att erhålla ytterligare en QALY. I den internationella litteraturen har detta värde kommit att benämnas v.

    Marginalproduktiviteten i hälso- och sjukvårdssektorn kan tänkas representera kostnaden för att generera ytterligare en QALY på marginalen i hälso- och sjukvårdssektorn. Tröskelvärdet med denna tolkning bör utgöra kostnaden per QALY för den minst kostnadseffektiva interventionen som återfinns inom hälso- och sjukvårdssektorn. I den internationella litteraturen benämns detta värde k.

    I rapporten diskuteras implikationerna av att använda de olika definitionerna i beslutsfattande samt hur de hänger ihop med alternativkostnader i olika delar av samhället. När en intervention tar resurser i anspråk som annars skulle ha använts till sjukvård är alternativkostnaden förlorad hälsa. Denna alternativkostnad kan representeras av marginalproduktiviteten i hälso- och sjukvårdssektorn, k. När en intervention tar resurser i anspråk som annars skulle ha använts för privat konsumtion är alternativ-kostnaden istället förlorad konsumtion, vilken kan representeras av konsumtionsvärdet av hälsa, v. Vilket perspektiv som anses relevant samt i vilken sektor konsekvenserna av olika interventioner upp-står bör därmed vara avgörande för vilken eller vilka definitioner av tröskelvärdet som kan behöva beaktas.

    Empiriska studier har i större utsträckning försökt skatta konsumtionsvärdet av hälsa (v) jämfört med marginalproduktiviteten i hälso- och sjukvårdssektorn (k). Kunskapen om båda storheterna är begränsad ur ett svenskt perspektiv. En större studie från England utgör det första och mest ambitiösa försöket att explicit skatta tröskelvärdet ur ett marginalproduktivitetsperspektiv med hjälp av större data-material. I den studien skattades tröskelvärdet till en kostnad per QALY motsvarande ungefär 150 000 kronor. I ett försök att översätta dessa skattningar till tröskelvärden i andra länder redovisas en kostnad per QALY i intervallet 170 000 till 210 000 kronor för Sverige. Skattningarna får anses vara behäftade med en hög grad av osäkerhet. Nyligen publicerade studier från Australien och Spanien redovisar skattningar motsvarande 185 00 och 250 000 kronor per QALY. I studier som undersökt konsumtions-värdet av hälsa redovisas skattningar på 30 000 till flera miljoner kronor per QALY.

    En stor del av variationen i resultaten kan troligtvis hänföras till metodologiska aspekter. Studierna varierar i flera dimensioner; praktisk undersökningsmetod (online, intervjuer eller pappersenkäter), utformning av svarsalternativ, statistiska metoder för att analysera data, typ av hälsoförändring som värderats (enbart livskvalitet, enbart livslängd eller en kombination), om värderade hälsoförändringar uppnås med säkerhet eller med en viss sannolikhet samt om hälsoförändringen som värderas tillfaller respondenten själv eller någon annan. Få studier med data från svenska individer där generella hälso-förändringar värderats av ett urval från allmänheten har identifierats. Den enda studien som vi identifierat i referentgranskade tidskrifter redovisar skattningarna för Sverige i intervallet 150 000 till 350 000 kronor. I en relativt ny svensk rapport som finns tillgänglig på Institutet för Hälso- och Sjukvårds-ekonomis (IHE) hemsida redovisas skattningar på 2,4 miljoner kronor per QALY.

    En slutsats i vår rapport är att det behöver tydliggöras hur valet av perspektiv faktiskt påverkar vilken eller vilka definitioner av tröskelvärdet som bör vara relevanta när hälsoekonomiska utvärderingar används som underlag vid beslutsfattande inom hälso- och sjukvården. Om ett bredare samhällsperspektiv anses relevant kan både konsumtionsvärdet av hälsa (v) och marginalproduktiviteten i hälso- och sjukvården (k) behöva beaktas.

    En annan slutsats är att oavsett vilken definition av tröskelvärde som anses relevant så har vi mycket begränsad kunskap om både marginalproduktiviteten i hälso- och sjukvårdssektorn och konsumtions-värdet av hälsa i en svensk kontext. Statistisk modellering av befintliga datakällor kan vara en fram-komlig väg för att skatta marginalproduktiviteten medan välgjorda experiment eller metoder för att studera individers värderingar av hälsa via faktiska beslut och ageranden i icke-experimentella situationer kan vara en framkomlig väg för att studera konsumtionsvärdet av hälsa.

  • Schierup, Carl-Ulrik
    Linköpings universitet, REMESO - Institutet för forskning om Migration, Etnicitet och Samhälle. Linköpings universitet, Filosofiska fakulteten.
    Sob o arco-íris: Migracão, precariedade e poder popular na África do sul pós-apartheid2018Inngår i: REMHU - Revista Interdisciplinar da Mobilidade Humana, ISSN 1980-8585, Vol. 26, nr 54, s. 115-150Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [pt]

    O artigo discute a precariedade como um ponto de convergênciapara a resistência, assim como uma condição social ligada à transição daelite na África do Sul pós-apartheid. Concentrando-se nas forças sistêmicasque impulsionam pobreza, desigualdade e meios de subsistência precários,o artigo aborda a transformação da força de trabalho da África do Sul e seusistema migratório desde uma gestão centralizada de trabalho não-livrepela burocracia estatal do apartheid para um Estado de precariedade pósapartheidmovido pela “flexploitation”. O nexo entre o trabalho precário euma fratura da cidadania é visto como um “dualismo da flexibilidade” queliga práticas de emprego e controle do trabalho a áreas como benefíciossociais, status de cidadania, participação política e meios de subsistênciainformais. Isso é aplicável tanto aos migrantes como aos nativos, sendoos migrantes particularmente “flexíveis”. O autor conecta a questão daprecariedade com a política da xenofobia, vista como um estratagemapara a manutenção de uma hegemonia política pós-apartheid noenfrentamento das desafiadoras lutas laborais e uma cidadania insurgentedos pobres.

  • Rombach, Markus
    Linköpings universitet, Institutionen för systemteknik, Reglerteknik.
    Vehicle Speed Estimation for Articulated Heavy-Duty Vehicles2018Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Common trends in the vehicle industry are semiautonomous functions and autonomous solutions. This new type of functionality sets high requirements on the knowledge about the state of the vehicle. A precise vehicle speed is important for many functions, and one example is the positioning system which often is reliant on an accurate speed estimation.

    This thesis investigates how an IMU (Inertial Measurement Unit), consisting of a gyroscope and an accelerometer, can support the vehicle speed estimation from wheel speed sensors. The IMU was for this purpose mounted on a wheelloader. To investigate the speed estimation EKFs (Extended Kalman Filters) with different vehicle and sensor models are implemented. Furthermore all filters are extended to Kalman smoothers.

    First an analysis of the sensors was performed. The EKFs were then developed and verified using a simulation model developed by Volvo Construction Equipment. The filters were also implemented on the wheel loader and tested on data collected from real world scenarios.

  • Jonsson, Erik
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Energisystem.
    Ingvarsson, Erik
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Energisystem.
    Isproduktion genom absorptionskyla vid Linköpings ishall: Samt kylning av ishallens kompressorkylmaskiner genom fjärrkyla2018Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [sv]

    Under sommarmånaderna är behovet i fjärrvärmenät lågt, vilket innebär att fjärrvärmeproducenter i större utsträckning kan elda de mest lönsamma bränslena för att täcka behovet. Vid Linköpings kraftvärmeverk eldas under sommarperioden stora mängder billigt avfall vilket leder till låga och ibland negativa marginalkostnader i produktionen. Därmed är det intressant att utnyttja denna värme i så stor mån som möjligt, vilket kan göras via fjärrvärmedrivna absorptionskylmaskiner. Absorptionskylmaskiner används i dagsläget för produktion av fjärrkyla i Linköping, men är dessutom möjliga att använda för isproduktion.Denna rapport är tänkt att agera underlag för de beslut som fastighetsbolaget Lejonfastigheter AB i Linköping tar angående framtiden för kylsystemet vid Linköpings ishall. Rapporten syftar till att utreda möjligheterna för att installera en absorptionskylmaskin för isproduktion till ispistarna vid området Stångebro i Linköping. Som komplettering till den befintliga maskinparken bestående av eldrivna kompressorkylmaskiner skulle en absorptionskylmaskin kunna leda till en minskad elförbrukning i isproduktionen.Utöver detta syftar rapporten även till att undersöka effektiviseringsåtgärder för de befintliga kompressorkylmaskinerna, i form av en sänkning av kondenseringstemperaturen. Temperatursänkningen, som innebär att hela kompressorcykeln blir effektivare och att kompressorernas elförbrukning sänks, uppnås genom att använda fjärrkyla i kylningen av kondensorerna.

    Resultaten visar att den undersökta absorptionskylmaskinen inte leder till några kostnadsminskningar, utan är lika dyr eller dyrare än de befintliga kompressorkylmaskinerna under större delen av året. Däremot visar sig ett byte av kondensorkylning för de befintliga kompressorkylmaskinerna från dagens kylning mot utomhusluft till kylning med fjärrkyla, kunna ge en årlig besparing på runt 350 000 kr. Denna siffra inkluderar även ett byte av komfortkyla från dagens system med kompressorkylmaskin, till att istället använda sig av fjärrkyla direkt. Dessutom kan en sänkning av den årliga abonnerade toppeffekten för den inköpta elektriciteten erhållas i och med kylmaskinernas ökade effektivitet. Inkluderat investeringskostnader, så som rörläggning, fås en ungefärlig återbetalningstid på 13 år.

    Arbetet i denna rapport innehåller ett antal uppskattningar och osäkerheter vilket gör att det verkliga fallet kan komma att skilja sig från de resultat som här presenteras. Det är därmed intressant för framtiden att i mera detalj studera hur en eventuell absorptionskylmaskin skulle passa in i systemet med kompressorkylmaskiner, samt hur fjärrkylenätet på bästa sätt integreras i arenaområdets energisystem.

  • Boito, Deneb
    Linköpings universitet, Institutionen för medicin och hälsa.
    Assessment of Divergence Free Wavelet Transform Filtering of 4D flow MRI Data for Cardiovascular Applications2018Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    4D flow MRI is an imaging technique able to provide relevant information on patients’ cardiac health condition both from a visual and a quantitative point of view. Its applicability is however limited by uncertainty in the data due to the presence of noise. A new class of filters, called divergence free filters, was recently proposed. They incorporate physical knowledge into the filtering of 4D flow data. One way to implement divergence filters is via wavelet transform. The filtering process using the Divergence Free Wavelet Transform can be carried out in a completely automated fashion and was shown to hold promising results.

    The focus of this thesis was thus put towards assessing the effect produced by these filters on a large cohort of patients. Time-resolved segmentations were incorporated into the filtering process as this was thought to enhance divergence reduction. They were also used to investigate the filtering in every region of the thoracic cardiovascular system. The assessment of the filters was carried out both from a visual and a quantitative perspective. In-house tools were used to compute clinically used parameters on the data before and after the filtering to investigate the introduced change.

    The results showed that the used method was able to reduce divergence like noise while preserving all the relevant information contained in the original data, in all the regions of the heart. Flow quantifications were essentially unchanged by the filtering suggesting that the method can be safely applied on 4D flow data.

  • Sodhro, Ali Hassan
    et al.
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska fakulteten. Electrical Engineering Department Sukkur IBA, Pakistan.
    Pirbhulal, Sandeep
    CAS, SIAT, Shenzhen, China .
    Sodhro, Gul Hassan
    Physics Shah Abdul Latif, Pakistan .
    Gurtov, Andrei
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska fakulteten.
    Muzamal, Muhammad
    Department of Computer Science Bahria University, Pakistan.
    Luo, Zongwei
    Shenzhen Key Laboratory of Computational Intelligence, China .
    A Joint Transmission Power Control and Duty-Cycle Approach for Smart Healthcare System2018Inngår i: IEEE Sensors Journal, ISSN 1530-437X, E-ISSN 1558-1748Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Emerging revolution in the healthcare has caught the attention of both the industry and academia due to the rapid proliferation in the wearable devices and innovative techniques. In the mean-time, Body Sensor Networks (BSNs) have become the potential candidate in transforming the entire landscape of the medical world. However, large battery lifetime and less power drain are very vital for these resource-constrained sensor devices while collecting the bio-signals. Hence, minimizing their charge and energy depletions are still very challenging tasks. It is examined through large real-time data sets that due to the dynamic nature of the wireless channel, the traditional predictive transmission power control (PTPC) and a constant transmission power techniques are no more supportive and potential candidates for BSNs. Thus this paper first, proposes a novel joint transmission power control (TPC) and duty-cycle adaptation based framework for pervasive healthcare. Second, adaptive energy-efficient transmission power control (AETPC) algorithm is developed by adapting the temporal variation in the on-body wireless channel amid static (i.e., standing and walking at a constant speed) and dynamic (i.e., running) body postures. Third, a Feedback Control-based duty-cycle algorithm is proposed for adjusting the execution period of tasks (i.e., sensing and transmission). Fourth, system-level battery and energy harvesting models are proposed for body sensor nodes by examining the energy depletion of sensing and transmission tasks. It is validated through Monte Carlo experimental analysis that proposed algorithm saves more energy of 11.5% with reasonable packet loss ratio (PLR) by adjusting both transmission power and duty-cycle unlike the conventional constant TPC and PTPC methods.

  • Andersson, Hanna
    Linköpings universitet, Matematiska institutionen, Matematik och tillämpad matematik. Linköpings universitet, Tekniska fakulteten.
    Den flippade läxan: En systematisk litteraturstudie av läxor i det flippade matematikklassrummet2018Independent thesis Basic level (professional degree), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Syftet med denna litteraturstudie är att redogöra för läxans roll i det flippade matematiklassrummet. Arbetsmetoden ”Flippat klassrum” karaktäriseras av en förflyttning av traditionella föreläsningar ut ur klassrummet. Direkta instruktioner ges istället som läxa, ”flippad läxa”, ofta i form av videoföreläsningar. Litteraturstudien baserar sig på nio artiklar och behandlar den flippade matematikläxans utformning, elevers åsikter om arbetsmetoden, och vilka fördelar respektive nackdelar flippad läxa har i förhållande till traditionell läxa. ”Flippad läxa” är fortfarande är ett relativt outforskat begrepp, vilket gör det svårt att dra generella slutsatser. Studiens resultat tyder dock på att metoden kan ha flera fördelar, bland annat i att videoföreläsningar som läxa ger eleverna ett större ansvar för sitt eget lärande, och att videons bestämda speltid har potential att minska skillnaden i den tid, som olika elever använder för att göra samma läxa.

  • Mona, Al-Chalabi
    Linköpings universitet, Matematiska institutionen, Matematik och tillämpad matematik. Linköpings universitet, Tekniska fakulteten.
    Svenska gymnasieelevers matematiska svårigheter att lösa linjära ekvationer och linjära ekvationssystem: En fallstudie2018Independent thesis Advanced level (professional degree), 10 poäng / 15 hpOppgave
    Abstract [sv]

    I studien undersöks svenska gymnasieelevers svårigheter att lösa linjära ekvationer och linjära ekvationssystem. Elever från två klasser, 29 elever, fick skriva ett test inom linjära ekvationer och linjära ekvationssystem och därefter ordnades en gruppintervju där intervjun ljudinspelades. Elevernas lösningar analyserades och gruppintervjun transkriberades och de funna matematiska svårigheterna av elevlösningar identifierades. Funna svårigheter i det tidigare konsumtionsarbete användes i denna studie för att jämföra med de matematiska svårigheterna och finna nya hos svenska gymnasieelever som kan vara användbara för framtida yrket. De mest förekommande svårigheter som resultatet av elevlösningar visar är bland annat hantering och beräkning av negativa tecken och rationella tal vid lösning av linjära ekvationer och linjära ekvationssystem.

  • Fältström, Emma
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Industriell miljöteknik. Linköpings universitet, Tekniska fakulteten. Sweden Water Research, Lund, Sweden.
    Gustafsson, Sara
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Industriell miljöteknik. Linköpings universitet, Tekniska fakulteten.
    Hagman, Marinette
    Sweden Water Research, Lund, Sweden.
    Wittgren, Hans Bertil
    Sweden Water Research, Lund, Sweden.
    Anderberg, Stefan
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Industriell miljöteknik. Linköpings universitet, Tekniska fakulteten.
    Kommunperspektiv på uppströmsarbete i Sverige i dag och i framtiden2018Rapport (Annet vitenskapelig)
    Abstract [sv]

    Uppströmsarbete inom vattensektorn är viktigt för att minska miljöförore­ningar i samhället och förhindra att föroreningar hamnar i kretsloppet av vatten och näringsämnen. Rapporten är ett första försök att beskriva upp­strömsarbetet i svenska VA-organisationer och hur det kan komma att se ut i framtiden. För att utveckla uppströmsarbetet behöver kommunerna mer vägledning och plattformar för erfarenhetsutbyte.

    I kommunerna pågår det uppströmsarbete för olika sorters vatten: spill­vatten, dagvatten och råvatten till dricksvattenproduktion. Projektet har undersökt hur kommunerna arbetar med alla tre vattentyperna. De tre hänger också ihop eftersom dagvatten och vatten från reningsverk kan rinna ut i recipienter som även fungerar som råvattentäkter. Vanligast är uppströmsarbete för spillvatten, dels för att skydda reningsprocessen och recipienten, dels för att höja slammets kvalitet. Uppströmsarbete startade redan på 1960-talet med kontroll av industriavlopp, men begreppet lan­serades först på 1990-talet. I Svenskt Vattens Revaq-certifiering av slam är uppströmsarbete en viktig del. Uppströmsarbete för dagvatten är svårare att genomföra än för spill- och råvatten eftersom det saknas gränsvärden och riktlinjer.

    Projektet identifierade först genom en litteraturgenomgång de verktyg som kan användas i uppströmsarbete. En enkätundersökning genomfördes sedan med 44 VA-organisationer, och tolv av dem valdes ut för intervjuer. Totalt medverkade 87 kommuner. Organisationerna fick berätta om sina behov och bidra med goda exempel. Majoriteten av dem som svarade på enkäten har någon form av uppströmsarbete. Arbetet fungerar för det mesta bra och anses vara viktigt. De flesta av organisationerna har mindre än en heltidstjänst för uppströmsarbete. Flera upplever att man skulle kunna göra mer, men att det kan vara svårt att avsätta tid och pengar när det inte är klarlagt vad arbetet innebär eller går att visa mätbart positiva effekter. Sam­arbetet med tillsynsmyndigheterna är viktigt, men ser olika ut i olika kom­muner. Här behövs det mer kunskap när det gäller hur ett samarbete kan och bör se ut.

    Enkäten och intervjuerna visar att det finns behov av vägledning, framför allt när det gäller dagvatten och hantering av fett i avloppssystemet, men även för uppströmsarbetet i stort. Det behövs också möjligheter till erfa­renhetsutbyte, till exempel ett nationellt nätverk och en konferens eller ett seminarium med fokus på uppströmsarbete.

    Huvudförfattare till rapporten är Emma Fältström, doktorand på Linkö­pings universitet och Sweden Water Research.

  • Glad, Wiktoria
    Linköpings universitet, Institutionen för tema, Tema teknik och social förändring. Linköpings universitet, Filosofiska fakulteten.
    Spaces for waste: Everyday recycling and sociospatial relationships2018Inngår i: Scottish Geographical Journal, ISSN 1470-2541, E-ISSN 1751-665X, Vol. 134, nr 3-4, s. 141-157Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Recycling of household waste has been proposed on different geographical levels as the key to sustainable resource management. This paper explores the sociospatial relationships of a waste management system at local level in Sweden. In this system, all waste was considered recyclable and tenants were expected to adopt certain recycling practices, although some prerequisites, such as language skills, were lacking. Theoretical approaches from geographies of power and surveillance studies are combined to analyse how spaces for waste at recycling stations were transformed and imbued with political claims of sustainability. The analyses are based on a detailed case study conducted in a neighbourhood of blocks of flats, with a focus on the design and use of recycling stations. In both their design and use, authority strategies were adopted to legitimise actions and influence recycling practices. Control measures were eventually taken and technologies were installed to restrict improper practices. Practices of discrimination were identified together with how recycling excluded some people from participating in the scheme. By using another power strategy, i.e. seduction, it was possible to reach and include more tenants.

  • Wärner, Hugo
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Konstruktionsmaterial. Linköpings universitet, Tekniska fakulteten.
    High-Temperature Fatigue Behaviour of Austenitic Stainless Steel: Influence of Ageing on Thermomechanical Fatigue and Creep-Fatigue Interaction2018Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    The global energy consumption is increasing and together with global warming from greenhouse gas emission, create the need for more environmental friendly energy production processes. Higher efficiency of biomass power plants can be achieved by increasing temperature and pressure in the boiler section and this would increase the generation of electricity along with the reduction in emission of greenhouse gases e.g. CO2. The power generation must also be flexible to be able to follow the demands of the energy market, this results in a need for cyclic operating conditions with alternating output and multiple start-ups and shut-downs.

    Because of the demands of flexibility, higher temperature and higher pressure in the boiler section of future biomass power plants, the demands on improved mechanical properties of the materials of these components are also increased. Properties like creep strength, thermomechanical fatigue resistance and high temperature corrosion resistance are critical for materials used in the next generation biomass power plants. Austenitic stainless steels are known to possess such good high temperature properties and are relatively cheap compared to the nickel-base alloys, which are already operating at high temperature cyclic conditions in other applications. The behaviour of austenitic stainless steels during these widened operating conditions are not yet fully understood.

    The aim of this licentiate thesis is to increase the knowledge of the mechanical behaviour at high temperature cyclic conditions for austenitic stainless steels. This is done by the use of thermomechanical fatigue- and creepfatigue testing at elevated temperatures. For safety reasons, the effect of prolonged service degradation is investigated by pre-ageing before mechanical testing. Microscopy is used to investigate the microstructural development and resulting damage behaviour of the austenitic stainless steels after testing. The results show that creep-fatigue interaction damage, creep damage and oxidation assisted cracking are present at high temperature cyclic conditions. In addition, simulated service degradation resulted in a detrimental embrittling effect due to the deterioration by the microstructural evolution.

    Delarbeid
    1. Creep-Fatigue Interaction in Heat Resistant Austenitic Alloys
    Åpne denne publikasjonen i ny fane eller vindu >>Creep-Fatigue Interaction in Heat Resistant Austenitic Alloys
    2018 (engelsk)Inngår i: MATEC Web of Conferences 165 , 05001 (2018) / [ed] EDP Sciences, EDP Sciences, 2018, Vol. 165Konferansepaper, Publicerat paper (Fagfellevurdert)
    sted, utgiver, år, opplag, sider
    EDP Sciences, 2018
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-148182 (URN)10.1051/matecconf/2018165505001 (DOI)
    Konferanse
    Fatigue 2018 , 12th International Fatigue Congress, 27 May-1 June 2018, Poitiers, France
    Tilgjengelig fra: 2018-06-01 Laget: 2018-06-01 Sist oppdatert: 2018-11-27
  • Dzabic, Daniel
    et al.
    Linköpings universitet, Institutionen för datavetenskap.
    Mårtensson, Jacob
    Linköpings universitet, Institutionen för datavetenskap.
    HTTP Based Adaptive Bitrate Streaming Protocols in Live Surveillance Systems2018Independent thesis Basic level (degree of Bachelor), 10,5 poäng / 16 hpOppgave
    Abstract [en]

    This thesis explores possible solutions to replace Adobe Flash Player by using tools already built into modern web browsers, and explores the tradeoffs between bitrate, quality, and delay when using an adaptive bitrate for live streamed video. Using an adaptive bitrate for streamed video was found to reduce stalls in playback for the client by adapting to the available bandwidth. A newer codec can further compress the video file size while maintaining the same video quality. This can improve the viewing experience for clients on a restricted or a congested network. The tests conducted in this thesis show that producing an adaptive bitrate stream and changing codecs is a very CPU intensive process.

  • Wallheim, Henrik
    Litteraturvetenskapliga institutionen, Uppsala universitet.
    En underbar berättelse om ridderliga äventyr: V.F. Palmblad och den romantiska romanen2007Doktoravhandling, monografi (Annet vitenskapelig)
    Abstract [en]

    Vilhelm Fredrik Palmblad (1788–1852) was one of the leading men of the Romantic circle in Uppsala, known as the “New school” or the “fosforists”. Among the men in this group, Palmblad was the one devoting most attention to the novel, and he broke sharply with the dominating negative view of the genre. This thesis examines Palmblad’s conception of the novel genre, using his critical writings as well as his own novels.

    Palmblad holds that the novel originates from the chivalrous romances of the Middle Ages. Like these romances, the novel is, and should be, a “wonderful story”, dealing with adventures and heroic deeds in service of God and womanhood. It is of decisive importance that the novel is elevated from mundane life: the stature of the characters and the story are crucial criteria of value. Palmblad also emphasizes the importance of portraying characters and their circumstances in an individualized way.

    Influenced in particular by Walter Scott, Palmblad gradually opens his conception of the novel towards depictions of everyday life. However, this opening is surrounded by restrictions showing that Palmblad still adheres to his Romantic aesthetics. The study challenges the previous understanding of Palmblad’s development from Romantic to Realist. Instead, the shifts of his aesthetics towards a stronger connection with reality ought to be understood as endeavours to preserve the ideals of the Romantic novel at a time when they were contested.

    From a wider horizon, the study also questions the prevalent understanding of the transition from the Romantic to the realistic novel. The aesthetic contrast between “Romanticism” and “Realism” ought to be played down. The truly important opposition among the Swedish novelists of the time is rather a political conflict between conservatives and liberals.

  • Rondini, Alice
    et al.
    CELS – Research group on Industrial Engineering and Service Operations-Università degli studi di Bergamo, Italy.
    Matschewsky, Johannes
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Industriell miljöteknik. Linköpings universitet, Tekniska fakulteten.
    Pezzotta, Giuditta
    CELS – Research group on Industrial Engineering and Service Operations-Università degli studi di Bergamo, Italy.
    Bertoni, Marco
    Department of Mechanical Engineering, Blekinge Institute of Technology, Karlskrona, Sweden.
    A simplified approach towards customer and provider value in PSS for small and medium-sized enterprises2018Inngår i: 10th CIRP Conference on Industrial Product-Service Systems, IPS2 2018, 29-31 May 2018, Linköping, Sweden / [ed] Tomohiko Sakao, Mattias Lindahl, Yang Liu, Carl Dalhammar, Elsevier , 2018, s. 61-66Konferansepaper (Fagfellevurdert)
    Abstract [en]

    While the provision of PSS is becoming more and more common, the transition toward a servitized business model is still critical. This is particularly true for small and medium-sized enterprises (SMEs) due to their limited internal resources and ability to define a servitization strategy. A crucial aspect during this transition is the identification of the right solutions to be implemented into the business that must render high value capture for providers and create value for customers. While a literature review showed that a large number of evaluation methods are available, these are often complex and require substantial amounts of resources in order to be carried out. This paper aims at supporting companies in taking decisions during early design phases by proposing a method that combines two existing approaches: The EVA method and the ProVa method. The combined method simplifies the existing ones while aiming at an easy implementation and application in SMEs. It is composed of two steps, the first pursuing the identification of valuable concepts from both the customer and the provider perspective; the second pursuing an individual analysis of the components available for use in the concepts selected. The application of the simplified method in a student-case of a startup company seeking to enter the distributed mobility market highlights the ease of use of the method in rendering valuable PSS concepts and in evaluating its specific components. 

  • Nåbo, Henning
    Linköpings universitet, Institutionen för datavetenskap, Programvara och system.
    Automatic modeling and analysis of corporate communication through multiple mediums2018Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    This thesis describes the process of modeling and analysis of corporate communication through chat and telephone with data taken from the Briteback enterprise communication application. Phone communication is measured by the number and duration of calls, and chat communication by the minimum number of messages sent from one person to another. The measurements are used to calculate a communication score, different methods are tested and a version using principal component analysis is chosen. Different centrality measurements are performed on the graph model that and each tested measure is found to be useful in some way; eigenvector centrality fits the data best, PageRank is easy to understand and can be adapted for dirfferent situations, and betweenness centrality points out users in critical positions in the communication graphs. Personalized PageRank ’focused’ on users or a group of users is tested and shows potential to be of use for social network service companies in many different ways such as when ordering search results or when suggesting new members to a chat channel.