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  • Andersson, Filip
    et al.
    Linköping University, Department of Management and Engineering, Machine Design.
    Martinsson, Niklas
    Linköping University, Department of Management and Engineering, Machine Design.
    Filter cleaning device: for truck cab climate systems2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Scania has identified a problem among certain costumers in very dusty environments. The air filters for their truck’s climate system need extensive maintenance, replacement or manual cleaning, because of dust frequently loading up the filters. In this thesis the problem has been analyzed in order to find a solution. The process was initiated by the usage of the black box method, where needed transformations were found, resulting in three needed technical systems. Thereafter, brainstorming was used to find concepts for each technical system. Concepts were compared and ranked against each other. For the most critical of the three systems, the cleaning action, prototypes were built of the four highest ranked concepts. These prototypes were then used to compare the performance between the concepts.

    The selected filter cleaning device consists of a method to analyze filter blockage, alert the driver when cleaning is needed and a system to clean the filter for the Scania climate system. The system consists of a pressure sensor used to measuring filter blockage, an air pulse system which cleans the filter and a controller unit to control the cleaning cycle and to inform the driver. The air pulse system has two main parts, a pulse valve and an air tank. The pulse valve is used for releasing the air accumulated in the air tank. The complete system is supplied with 8.5 bar from the internal air pressure system in the truck and a 24 V power supply, also located in the truck.

    A suggestion on how a final implementation can be done has been developed, with a minimized number of variants and modifications of parts already in production. A proof of concept was built and mounted in a truck to validate the complete system. Numbers on cleaning performance and sound levels have been produced. The proof of concept manages to remove the restriction created from dust by approximately 50 %.

    Aside from developing a suitable filter cleaning device, figures on when the filter needs to be cleaned have been identified. To keep a good working environment within the cab a pressure drop over the filter of 936 Pa is recommended as a point of cleaning. This is to maintain the needed airflow of at least 123 m3/h with two persons seated in the cab to not exceed regulated levels of CO2 within the truck cab.

  • Wijma, Barbro
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Children's and Women's health. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center of Paediatrics and Gynaecology and Obstetrics, Department of Gynaecology and Obstetrics in Linköping.
    Persson, Alma
    Linköping University, Department of Thematic Studies, The Department of Gender Studies. Linköping University, Faculty of Arts and Sciences.
    Ockander, Marlene
    Jönköping Academy for Improvement of Health and Welfare, Jönköping University.
    Brüggemann, Adrianus Jelmer
    Linköping University, Department of Thematic Studies, Technology and Social Change. Linköping University, Faculty of Arts and Sciences.
    Kränkningar i vården är vanligt förekommande: Viktigt med aktivt arbete mot att patienter kränks2019In: Läkartidningen, ISSN 0023-7205, E-ISSN 1652-7518, p. 1-6Article in journal (Other academic)
    Abstract [sv]

    Trots goda intentioner hos vårdpersonal upplever patienter ofta möten i vården som misslyckade. Det kan vara möten där patienten har fått en helt korrekt medicinsk behandling, men av andra anledningar upplever sig kränkt eller överkörd. Ofta lägger vårdgivare inte ens märke till att det sker. Om patienten i efterhand försöker få upprättelse är det heller inte säkert att ett sådant samtal når sitt syfte. Ämnet kränkningar i vården är tabubelagt och känslomässigt laddat. För att ge legitimitet åt insatser att hjälpa personal att motverka kränkningar behövs därför en god kunskapsbas.

    Med denna utgångspunkt startades för 20 år sedan ett nytt forskningsfält om kränkningar i vården vid enheten för genus och medicin, Linköpings universitet. I denna artikel redovisar forskargruppen några av sina resultat och lärdomar.

  • Capshaw, Riley
    Linköping University, Department of Computer and Information Science, Human-Centered systems.
    Relation Classification using Semantically-Enhanced Syntactic Dependency Paths: Combining Semantic and Syntactic Dependencies for Relation Classification using Long Short-Term Memory Networks2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Many approaches to solving tasks in the field of Natural Language Processing (NLP) use syntactic dependency trees (SDTs) as a feature to represent the latent nonlinear structure within sentences. Recently, work in parsing sentences to graph-based structures which encode semantic relationships between words—called semantic dependency graphs (SDGs)—has gained interest. This thesis seeks to explore the use of SDGs in place of and alongside SDTs within a relation classification system based on long short-term memory (LSTM) neural networks. Two methods for handling the information in these graphs are presented and compared between two SDG formalisms. Three new relation extraction system architectures have been created based on these methods and are compared to a recent state-of-the-art LSTM-based system, showing comparable results when semantic dependencies are used to enhance syntactic dependencies, but with significantly fewer training parameters.

  • Eklund, Olov
    Linköping University, Department of Computer and Information Science.
    Utvärderingsprogram för radomer2019Independent thesis Basic level (degree of Bachelor), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [sv]

    Under 1930-talet utvecklades RADAR (Radio Detection and Ranging) av många länder samtidigt och oberoende av varandra. Radarn utvecklades för att kunna upptäcka fientliga objekt, till exempel flygplan. Ett problem var att radarantennen utsätts för väder, vind och andra miljörelaterade påfrestningar. Lösningen till detta problem var att sätta ett skydd ovanpå radarn. Detta skydd kallas för en radom. Radom är en akronym från engelskans radar dome.

    SAAB Applied Composites AB, ACAB (tidigare GKN Applied Composites AB ) tillverkar och utvecklar bland annat radomer i form av noskoner till flygplan. Radomen fungerar som skydd för radarantennen. För att undersöka radomens radaregenskaper utförs mätningar på radarn med och utan radom. Detta generar en stor mängd mätdata. Examensarbetets syfte är att ta fram ett datorprogram som samlar och behandlar denna mätdata samt presenterar data grafiskt. Programmet som utveklades heter OErep.

    Examensarbetet har resulterat i ett program OErep som fungerar som ett ramverk för vidare utveckling av ett testprogram för utvärdering av radomemätdata. För detta har C++ använts som programeringsspråk. Arbetet har utförts delvis på Applied Composites AB och delvis på Linköpings Universitet.

    Avgränsningar

    I detta examensarbetet behandlas enbart funktionerna Transmission Efficiency, Sidelobe Level och Main Lobe Beam Width. Det finns betydligt fler funktioner som inte behandlats i detta arbete.

    Syfte

    Vid mätningar av radomer generas stora mängder mätdata som behandlas på ett semi-manuelt sätt. Syftet med detta examensarbetet är att utveckla ett program som underlättar sammanställning och behandlingen av den insamlade datan.

  • Frisk, Johan
    Linköping University, Department of Computer and Information Science, Database and information techniques.
    Cross Continental Access of Information and the Boarder Gateway Protocol2019Independent thesis Basic level (university diploma), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [en]

    The usage of technical equipment and the interconnection of all these devices has become essential to our every day life and to provide as good service as possible for the internet of today. However, many have the opportunity to inspect the data as it is being rushed across the globe to provide users with information at the press of a button.

    This study examines the routing patterns from hundred thousands of trace routes going from user to server around the globe. Using this trace data, we demonstrate not only the number of companies involved in data transfers on other continents then where they are currently not residing, but also give some insight into the amount of routes pertaining to same continent data transfers which takes paths not contained within that same continent.

    In doing so, we try to explain the inner workings of the protocols used within the process of data transfer, answer a number of security related questions regarding the protocols used, as well as discuss which other circumstances can affect the decision making process.

  • Karlsson, Malin
    et al.
    Linköping University, Department of Social and Welfare Studies.
    Jarlinius, Mikaela
    Linköping University, Department of Social and Welfare Studies.
    "Jag letar efter något som heter 'integritet'": -Värdegrundsarbete genom barnlitteratur i årskurs F-32018Student paper other, 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Syftet med denna strukturerade litteraturstudie är att undersöka hur skönlitteratur som verktyg kan användas i värdegrundsarbetet, med inriktning på integritet som en mänsklig rättighet.  I studien har både manuella sökningar och databassökningar genomförts för att hitta relevant forskning. Detta är en latent kvalitativ innehållsanalys där syftet är preciserat i en frågeställning: Vad säger litteraturvetenskaplig forskning om barnlitteraturens användningsområden gällande värdegrundsfrågor i samhällskunskapsdidaktik, i årskurs F-3? Vårt resultat visar att skönlitteraturen öppnar upp för möjligheter att arbeta med integritet som en mänsklig rättighet i samhällskunskapsundervisningen för årskurs F-3. Resultatet visar att skönlitteraturens möjligheter, förankrat i kunskapsarbetet, kan leda till en reflekterad och genomtänkt värdegrundsundervisning.

  • Thunberg, Anna
    et al.
    Linköping University, Department of Social and Welfare Studies. 1994.
    Bergvich, Felicia
    Linköping University, Department of Social and Welfare Studies.
    Att samtala om döden: En litteraturstudie om hur ämnet döden behandlas  i religionsundervisningen för grundskolan2018Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Det här är en strukturerad litteraturstudie med syfte att undersöka vad tidigare forskning säger om hur lärare samtalar om döden i religionsundervisningen samt vilka svårigheter som kan uppkomma. Insamling av material har gjorts både med manuella sökningsmetoder samt olika databassökningar, såsom ERIC, UniSearch och Google Scholar. Sökningen resulterade i elva utvalda artiklar som noga granskats för att sedan analyseras. Resultatet av detta arbete visar att döden är ett väldigt komplext ämne som många lärare väljer att undvika. Det beror bland annat på bristande didaktiska kunskaper hos lärarna. Lärare som granskats i denna studie anser att döden är ett väldigt känsligt ämne som det inte finns ett tydligt tillvägagångsätt för hur de ska samtala om det med eleverna. En annan svårighet som gör ämnet mer komplext är religionstillhörighet och föräldrars tankar om döden. Lärare anser att det är svårt att samtala om det på grund av mångfalden av trosuppfattningar i dagens samhälle. Resultatet visar även en tydligt bristande förståelse för barns tankar om döden från lärarnas sida.

  • Säll, Jakob
    Linköping University, Department of Computer and Information Science.
    Augmented Remote Guidance in Final Assembly of Military Aircraft2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    With today’s smartphones and smart glasses, and the progression of augmented reality, the possibilities to interact over distance has made it feasible to guide one another in an intuitive and effective way. This combination of technology and software principles allows a local operator to record a scenario from his or her point of view and show this to a remotely located expert. An expert can, in turn, help the operator by interacting through that video feed by highlighting aspects and overlaying information for the operator to see. The aim of this study was to investigate how such a system should be configured if it were to be implemented in the context of final assembly of military aircraft.

    An understanding of the context and situations where external help might be needed was established through an ethnographical study. User tests were conducted with an existing system in comparable cases, inspired by results from the first study. This in order to evaluate the configuration of the hardware and interactivity. Results indicate that it is useful to implement a remote guidance system which allows augmented overlays in the context of final assembly. A greater need for such a system was found in situations in which a subject matter expert must investigate and assess issues and errors that has occurred. These scenarios are often characterized by differentiating environment, from cases where there is a good overview to situations in which the mirrors must be used to see from the right angle beyond one’s field of view. A remote guidance system should be able to support both cases and must, therefore, be modular in a way so that an external camera can be used to reach in while the screen can be seen simultaneously. Regarding the need for interaction between interactors in such situations are limited. The user studies indicate that simple referential gestures on frozen images of a video feed might be enough.

  • Bäck, Jesper
    Linköping University, Department of Computer and Information Science, Human-Centered systems.
    Domain similarity metrics for predicting transfer learning performance2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The lack of training data is a common problem in machine learning. One solution to thisproblem is to use transfer learning to remove or reduce the requirement of training data.Selecting datasets for transfer learning can be difficult however. As a possible solution, thisstudy proposes the domain similarity metrics document vector distance (DVD) and termfrequency-inverse document frequency (TF-IDF) distance. DVD and TF-IDF could aid inselecting datasets for good transfer learning when there is no data from the target domain.The simple metric, shared vocabulary, is used as a baseline to check whether DVD or TF-IDF can indicate a better choice for a fine-tuning dataset. SQuAD is a popular questionanswering dataset which has been proven useful for pre-training models for transfer learn-ing. The results were therefore measured by pre-training a model on the SQuAD datasetand fine-tuning on a selection of different datasets. The proposed metrics were used tomeasure the similarity between the datasets to see whether there was a correlation betweentransfer learning effect and similarity. The results found a clear relation between a smalldistance according to the DVD metric and good transfer learning. This could prove usefulfor a target domain without training data, a model could be trained on a big dataset andfine-tuned on a small dataset that is very similar to the target domain. It was also foundthat even small amount of training data from the target domain can be used to fine-tune amodel pre-trained on another domain of data, achieving better performance compared toonly training on data from the target domain.

  • Berkesand, Peter
    Linköping University, University Library.
    Teknisk utvärdering av elektroniska publiceringsplattformar2003Report (Other academic)
    Abstract [sv]

    I samband med universitetets utredning Universitetets informationsförsörjning tillsattes resursgrupper. En av dessa grupper var tekniska gruppen som fick i uppgift att se över vilka publiceringssystem som finns.

    Gruppen har undersökt vilka publiceringsplattformar tillgängliga för elektronisk publicering av vetenskapliga publikationer som kan vara intressanta för E-press. Inom gruppen har diskussioner förts kring de olika plattformarna.

    Vid studiebesök och egna tester framstår för närvarande DiVA som det mest genomarbetade systemet för elektronisk publicering. Vi får ett helt igenom färdigt publiceringssystem som går att använda efter några justeringar för att anpassa det till våra behov.

    Både EPrints och DSpace bör utvärderas mer. I synnerhet DSpace som inte ännu används i Sverige. Eventuellt kommer både DSpace och EPrints att installeras och utvärderas närmare under hösten 2003.

  • Gustavsson, Erik
    et al.
    Linköping University, Department of Culture and Communication, Culture and Aesthetics. Linköping University, Faculty of Arts and Sciences.
    Sandman, Lars
    Linköping University, Department of Medical and Health Sciences, Division of Health Care Analysis. Linköping University, Faculty of Medicine and Health Sciences.
    Etisk analys av pre-expositionsprofylax (PrEP) för hiv2018Report (Other academic)
    Abstract [sv]

    Föreliggande etiska analys rör pre- expositionsprofylax (PrEP) mot hiv som en hivnegativ person kan ta för att minska risken för att drabbas av en hivinfektion. Om PrEP tas som ordinerat ger det en ungefärlig skyddsgrad mot hiv på 85 % jämfört med en kontrollgrupp. Eftersom PrEP inte ger 100 % skydd och inte heller skyddar mot andra sexuellt överförbara sjukdomar så är rekommendationen att det tas i kombination med praktiserandet av säkert sex.

    Den här etiska analysen har gjorts på uppdrag av NT-rådet och behandlar följande två frågeställningar: 1) finns det etiska skäl som talar emot förskrivning av PrEP; (2) hur bör PrEP prioriteras i relation till den etiska plattformen med ett särskilt fokus på huruvida PrEP bör egenfinanseras. Det finns starka skäl att minska smittspridningen av hiv utifrån såväl ett individ- som ett samhällsperspektiv vilket talar för förskrivning av PrEP. I diskussionen kring PrEP har det dock framförts att PrEP skiljer sig från annan preventiv behandling för att minska smittspridning på ett sätt som talar emot att PrEP förskrivs. Den etiska analysen diskuterar ett antal sådana argument: att friska personer utan medicinskt behov behandlas, att det handlar om ett socialt riskbeteende, att individer själva bör ta ansvar för smittspridning genom att ändra sitt beteende, samt risken för resistensproblematik. Slutsatsen är att inte något av dessa motargument är tillräckligt starkt för att tala emot förskrivningen av PrEP.

    När det gäller prioritering av PrEP i relation till den etiska plattformen dras slutsatsen att PrEP hamnar i den lägre delen av prioriteringsskalan baserat på svårighetsgraden hos tillståndet som PrEP riktar sig emot. Det innebär att PrEP skulle kunna vara en kandidat för egenfinansiering.

    Eftersom den etiska plattformen säger mycket lite om vilka åtgärder som bör egenfinaiseras så har analysen utgått från två ramverk presenterade i den internationella literaturen. Trots att flera aspekter av dessa ramverk talar för att PrEP skulle vara passande för egenfinansiering så väger aspekten av minskad smittspridning tungt. Dessa positiva externa effekter tillsammans med svårigheten att bedöma huruvida patientpopulationen skulle kunna egenfinansiera PrEP bidrar till bedömningen att PrEP bör finansieras inom ramen för det offentliga åtagandet.

  • Tranell, Victor
    Linköping University, Department of Electrical Engineering, Computer Vision.
    Semantic Segmentation of Oblique Views in a 3D-Environment2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This thesis presents and evaluates different methods to semantically segment 3D-models by rendered 2D-views. The 2D-views are segmented separately and then merged together. The thesis evaluates three different merge strategies, two different classification architectures, how many views should be rendered and how these rendered views should be arranged. The results are evaluated both quantitatively and qualitatively and then compared with the current classifier at Vricon presented in [30].

    The conclusion of this thesis is that there is a performance gain to be had using this method. The best model was using two views and attains an accuracy of 90.89% which can be compared with 84.52% achieved by the single view network from [30]. The best nine view system achieved a 87.72%. The difference in accuracy between the two and the nine view system is attributed to the higher quality mesh on the sunny side of objects, which typically is the south side.

    The thesis provides a proof of concept and there are still many areas where the system can be improved. One of them being the extraction of training data which seemingly would have a huge impact on the performance.

  • Komulainen, Oscar
    et al.
    Linköping University, Department of Science and Technology, Media and Information Technology. Linköping University, Faculty of Science & Engineering.
    Lögdlund, Måns
    Linköping University, Department of Science and Technology, Media and Information Technology. Linköping University, Faculty of Science & Engineering.
    Navigation and tools in a virtual crime scene2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Revisiting a crime scene is a vital part of investigating a crime. When physically visiting a crime scene there is however always a risk of contaminating the scene, and when working on a cold case, chances are that the physical crime has been altered. This thesis aims to explore what tools a criminal investigator would need to investigate a crime in a virtual environment and if a virtual reconstruction of a crime scene can be used to aid investigators when solving crimes. To explore these questions, an application has been developed in Unreal Engine that uses virtual reality (VR) to investigate a scene, reconstructed from data that has been obtained through laser scanning. The result is an application where the user is located in the court of Stockholm city, which was scanned with a laser scanner by NFC in conjunction with the terror attack on Drottninggatan in April 2017. The user can choose between a set of tools, e.g. a measuring tool and to place certain objects in the scene, in order to draw conclusions of what has happened. User tests with criminal investigators show that this type of application might be of use in some way for the Swedish police. It is however not clear how or when this would be possible which can be expected since this is a new type of application that has not been used by the police before.

  • Aldén, Fanny
    et al.
    Linköping University, Department of Science and Technology, Media and Information Technology. Linköping University, Faculty of Science & Engineering.
    Juopperi, Emil
    Linköping University, Department of Science and Technology, Media and Information Technology. Linköping University, Faculty of Science & Engineering.
    UX-verktyg för prototyputveckling med AI-baserat automationsstöd för omvandling av skisser till gränssnittskomponenter2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Att skapa prototyper för att testa idéer är vanligt, oavsett vad det är som ska testas. Prototyper kan förekomma i oändligt olika former och vara mer eller mindre verklighetstrogna. Hur verklighetstrogen en prototyp är beror på vad som ska testas och hur mycket tid som läggs på prototypskapandet. I teknikbranschen är prototyperna vanligen digitala och skapas med prototypprogram. Eftersom tid är pengar så försöker företag effektivisera prototyprocessen genom att utforska nya tekniker, som exempelvis artificiell intelligens. Syftet med examensarbetet som beskrivs i den här rapporten är att undersöka hur ett prototypverktyg med automation bör utformas samt vilka eventuella användningsområde verktyget har. Under examensarbetet genomfördes intervjuer med anställda på konsultföretaget Exsitec. Syftet med intervjuerna var att ta reda på hur Exsitec arbetar med prototyper i uppstarten av sina projekt. Med hjälp av informationen identifierades svårigheter i arbetsprocessen. Utifrån den informationen utvecklades prototypverktyget ProtoDraw. Verktyget är utrustat med artificiell intelligens, som känner igen skisser och ger utifrån dem rekommendationer på webbkomponenter. Prototypverktyget utvecklades, tränades och testades som en del av fallstudien. Målet med fallstudien var att testa användares förtroende för verktyget samt hur förtroendet berodde på verktygets automationsnivå. Prototypverktyget utrustades med tre automationsnivåer interaktionsmodell A, interaktionsmodell B och interaktionsmodell C. Interaktionsmodell A gav alla förslag till användaren och rekommenderade de mest lika komponenterna genom att rama in dem. I interaktionsmodell B fick användaren endast de tre bästa resultaten. I interaktionsmodell C fick användaren endast ett förslag från automationen. Totalt genomfördes 15 användartester, fem stycken på varje nivå. Resultatet från användartesterna visade att interaktionsmodell B hade högst och stadigast förtroende. Interaktionsmodell B var även nivån som användarna ansåg var mest användbar. Trots detta var A nivån som användarna utförde uppgifterna i användartesterna på kortast tid. C hade den långsammaste tiden och det berodde på att den höga automationsnivån bidrog till att gränssnittet blev känsligt för fel.

  • Astudillo, Miguel
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Ferneborg, Oskar
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Samplanering av allmän och särskild kollektivtrafik i Dalarnas län, för ett effektivare utnyttjande av tillgängliga resurser2018Independent thesis Basic level (degree of Bachelor), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [en]

    Kollektivtrafiken är en vital del för att ett samhälle ska fungera på ett effektivt sätt. Idag är det många personer som är beroende av att kollektivtrafiken ska fungera som utlovat för att exempelvis ta sig till arbetet eller för att få den vård de behöver. Kollektivtrafiken delas ofta upp i två genrer: den allmänna kollektivtrafiken och den särskilda kollektivtrafiken. Den allmänna kollektivtrafiken är bland annat den, som de flesta tänker på när de hör ordet kollektivtrafik, linjestyrda kollektivtrafiken. Kollektivtrafiken innefattar dock även bland sjukresor, skolskjuts och färdtjänst vilket inkluderas i den särskilda kollektivtrafiken. Syftet med detta examensarbete var att undersöka vilka förutsättningar som är nödvändiga för att en samplanering mellan den allmänna – och särskilda kollektivtrafiken ska vara möjlig. Samt presentera vilka konsekvenser en ökad samplanering av kollektivtrafiken i Ludvika kommun skulle medföra. Med en teoretisk bakgrund, undersökningar av lämpliga metoder, den data Dalatrafik gjorde tillgänglig och genom intervjuer genomförda med Dalatrafik, Västtrafik och Kalmar länstrafik lades den kunskapsgrund som krävdes för att arbetet skulle kunna ta form. Materialet som erhölls utifrån intervjuerna och den informationen som kunde utläsas från Dalatrafiks data användes sedan för att beskriva hur kollektivtrafikssituationen såg ut för Ludvika kommun och utifrån detta nuläge identifierades förbättringsområden. Utifrån dessa förbättringsområden togs det fram åtgärdsförslag för att på ett konkret vis belysa möjliga tillvägagångssätt för att förbättra kollektivtrafikssituationen genom en ökad samplanering i Ludvika kommun. Slutligen diskuteras de resultat och åtgärdsförslag som tagits fram och även de förutsättningar som behövs för att en samplanering ska vara möjlig. Bland annat föreslås en utökning av flexlinjen och en justering av skolstarter. Dessutom ges förslag om hur Dalatrafik skulle kunna ta till sig detta examensarbete och fortsätta arbetet.

  • berglund, Mattias
    Linköping University, Department of Electrical Engineering, Communication Systems.
    Bluetooth LE Mesh Network in an Industrial Environment2018Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    With wireless signals, it is possible to send all kind of data through a communication system. Many companies today having problems implementing wireless communication system because of big areas and many obstacles that blocks the wireless signals. Recent releases of mesh network standards that has the main objective to provide a network over a large area. Toyota Material Handling Europe (TMHE) that develops and produce trucks is one company that wants to use this new network topology to get to the next level of communication.

    TMHE is developing a new communication system between their trucks and the goal is to be independent of Wi-Fi and fixed structures in an industry. The aim is to establish communication through Bluetooth and create a mesh network between the trucks at a site. This kind of communication can create many new possibilities for new features, which can make the daily work easier.

    The problem with obstacles and interferences is still a problem and TMHE created a thesis to research Bluetooth mesh networks to see if this kind of implementation is suitable for the environments that exists in an industry. This thesis research the architecture of a Bluetooth mesh network and different setups of a network and tests how it stands in an industry with many different surrounding.

  • Bjurström, Anna
    et al.
    Linköping University, Department of Social and Welfare Studies, Division of Occupational Therapy. Linköping University, Faculty of Medicine and Health Sciences.
    Kindmark, Sofie
    Linköping University, Department of Social and Welfare Studies, Division of Occupational Therapy. Linköping University, Faculty of Medicine and Health Sciences.
    Levnadsvanor och delaktighet bland patienter i den rättspsykiatriska slutenvården: En kvalitativ studie utifrån ett professionellt perspektiv2018Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Ohälsosamma levnadsvanor är ett problem bland patienter som vårdas inom den rättspsykiatriska slutenvården. Patienter med psykisk ohälsa har en sårbarhet och löper större risk att drabbas av livsstilsrelaterade sjukdomar och för tidig död. Syftet är att beskriva hur personalen inom rättspsykiatrisk slutenvård upplever patienternas förutsättningar till att skapa hälsofrämjande levnadsvanor. Studien omfattar kvalitativ studiedesign där åtta personer som arbetar inom rättspsykiatrisk slutenvård intervjuades. I resultatet framkommer det att begränsningen av valet och möjligheten att engagera sig i aktiviteter inverkar negativt på en persons hälsa. Patienterna på kliniken har olika förutsättningar till delaktighet i aktivitet. Resultatet visar att patienternas tidigare vanemönster har inverkan på vilka levnadsvanor patienten har inom slutenvården. Personer med psykisk ohälsa stöter på många hinder i att skapa hälsofrämjande levnadsvanor då de beskrivs ha bristande insikt över vilka konsekvenser deras handlade får i relation till deras hälsa Patientgruppen framställs som rädda för livet utanför den rättspsykiatriska slutenvården och beskrivs trygga i det hospitaliserade klimatet. Detta resulterar i att många vill och blir kvar. Arbetsterapeutens kunskap kring vanor och roller är betydande vid förändring av patienternas levnadsvanor och arbetsterapeutiska insatser kan riktas mot att främja återgång i samhällslivet. Omfattningen forskning inom ämnet är bristande och det behövs mer kunskap om hur rättspsykiatriska kliniker kan arbeta för att främja hälsa och välmående för målgruppen.

  • Engblom, Karolina
    et al.
    Linköping University, Department of Behavioural Sciences and Learning.
    Trygg, Karolina
    Linköping University, Department of Behavioural Sciences and Learning.
    Läsförståelsestrategiernas betydelse: En litteraturstudie om läsförståelestrategier och deras påverkan på elevers läsförståelseinlärning i årskurs F-32018Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Syftet med denna studie är att beskriva lärares och elevers arbete med läsförståelse i årskurs F-3 samt undersöka vilka svårigheter och vinster arbetet kan innebära. I denna kvalitativa litteraturstudie har metodinsamlingen inneburit sökningar i databaser. Sammanlagt har 16 vetenskapliga forskningsartiklar legat till grund för resultaten av denna studie.

    Resultaten visar att F-3 lärare ger en explicit undervisning i läsförståelsestrategier innan, under och efter läsning. Resultaten visar vidare att läsförståelsestrategierna används under muntligt och skriftligt textarbete samt under den tysta läsningen. Läsförståelsestrategierna förutspå, visualisera, göra inferenser, ställa frågor, övervaka sin egen läsning, ta ut viktiga delar ur texten och sammanfatta används under samtliga arbetsformer. Instruktioner av läsförståelsestrategier, lärarens modellering och en guidning i hur läsförståelsestrategierna ska användas är grunden för att eleverna efter hand ska uppnå ett självreglerat lärande. Studien visar att undervisning i läsförståelsestrategier ger en ökad läsförståelseförmåga för alla elever, oavsett etnisk bakgrund eller kunskapsnivå. Det framkom att strategierna visualisera och sammanfatta var svårast. Lyckas inte eleverna att tillämpa dessa strategier påverkas elevernas lärande negativt. Forskningen framhåller därför vikten av mycket modellering och träning i dessa strategier. Resultatet visar även att elevers lärande påverkas positivt av arbete med strategin visualisera. Eleverna tar då hjälp av grafiska och visuella hjälpmedel för att utveckla förmågan att skapa inre bilder och konkretisera textens innehåll.

    I diskussionen framhålls betydelsen av att läraren använder scaffolding i strategiundervisningen. En form av scaffolding utgörs av skriftligt stöd, lärarens modellering samt via elevutbyte i grupper. Undervisning i läsförståelsestrategier med scaffolding som stöd skapar goda förutsättningar för eleverna att återge viktiga delar ur texten och föra resonemang om textens innehåll, vilket innefattar kunskapskraven för årskurs 1 i den svenska läroplanen.

  • Dianne, Mwanje
    Linköping University, Department of Thematic Studies, Tema Environmental Change.
    Smokeless homes: Challenges for Increasing Use of Improved Biomass Cookstoves in Kisumu, Kenya.2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In Kenya, 69 percent of populations depend on biomass fuels to meet their cooking needs. The incomplete combustion of biomass is performed in insufficiently ventilated settings thus exposing human health and environment to toxic pollution. To date, women and children in resource limited settings have been most vulnerable to severe respiratory infections. The promotion of the Improved Biomass Cookstoves has become a popular issue in policy, research and practice. Community Based Organizations have however faced serious challenges in increasing sustainable use of the cookstoves among users. This qualitative study investigates the role of Community Based Organizations in promoting the Improved Biomass Cookstoves through women’s empowerment initiatives. It applies focus group interviews, questionnaire and formal interviews. 11 interview forms were administered to 30 women, 2 key informants and 3 implementing Community Based Organization representatives in Dunga wetland community. A combination of previous research and this empirical study show that economic resources, small diameter stove designs as well as insufficient policy support hinder effective stove programmes. While there is general adoption, women lack sufficient income and ownership of land which is a significant resource to empowerment. Women informal financial networks are instrumental in driving behavioral change towards clean cooking in the community. Sufficient gender sensitive policy intervention and support can provide effective channels to ensure sustainable incomes of women, livelihoods and stove use.

  • Dehlin, Carl
    Linköping University, Department of Electrical Engineering, Computer Vision.
    Visual Tracking Using Stereo Images2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Visual tracking concerns the problem of following an arbitrary object in a video sequence. In this thesis, we examine how to use stereo images to extend existing visual tracking algorithms, which methods exists to obtain information from stereo images, and how the results change as the parameters to each tracker vary. For this purpose, four abstract approaches are identified, with five distinct implementations. Each tracker implementation is an extension of a baseline algorithm, MOSSE. The free parameters of each model are optimized with respect to two different evaluation strategies called nor- and wir-tests, and four different objective functions, which are then fixed when comparing the models against each other. The results are created on single target tracks extracted from the KITTI tracking dataset, and the optimization results show that none of the objective functions are sensitive to the exposed parameters under the joint selection of model and dataset. The evaluation results also shows that none of the extensions improve the results of the baseline tracker.

  • Persson, Malin
    et al.
    Linköping University, Department of Behavioural Sciences and Learning.
    Addén, Ida
    Linköping University, Department of Behavioural Sciences and Learning.
    Högläsningens betydelse i klassrummet: En litteraturstudie över arbetssätt och effekter av högläsning2018Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Syftet med denna litteraturstudie är att undersöka högläsningens betydelse i klassrummet med inriktning mot förskoleklass till årskurs tre. I studien granskas arbetssätt kring högläsning och högläsningens effekter på eleverna.

     

    Materialinsamlingen för den här kvalitativa litteraturstudien har genomförts via databaser och manuella sökningar. Resultatet av våra sökningar gav oss tolv vetenskapliga artiklar som ligger till grund för denna litteraturstudie. Genom artiklarna har vi hittat följande teman: boksamtal, modeller för arbete med högläsning, läsning i grupp, ordförråd, förståelse av text och motivation.

     

    Litteraturstudien visar att lärarens högläsning har betydande effekter på elevernas språkutveckling. Forskningen visar att högläsning kan genomföras på olika sätt där det interaktiva samspelet blir en viktig del för en givande högläsning. När undervisningen grundar sig i dessa arbetssätt bidrar det till många påtagliga effekter hos eleverna. De främsta effekterna är en utveckling av ordförråd, förståelse och motivation. 

  • Skoogh, Frida
    et al.
    Linköping University, Department of Social and Welfare Studies, Social Work.
    Fast, Isabelle
    Linköping University, Department of Social and Welfare Studies, Social Work.
    Den omhändertagna sexualiteten: En diskursanalys av hur flickors sexualitet konstrueras i förvaltningsrättsliga domar enligt §3 LVU2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Syftet med denna kvalitativa dokumentstudie är att med feministisk kritisk teori belysa hur flickors sexualitet konstrueras som en del av en problembild i förvaltningsrättsliga domar vid beslut om tvångsvård enligt §3 Lag (1990:52) med särskilda bestämmelser om vård av unga och specifikt enligt rekvisitet annat socialt nedbrytande beteende. Studiens empiri består av domskälen i 17 rättsfall i första instans där flickorna i domarna är 15–18 år gamla. Genom att studera domskälen vid tillämpandet av rekvisitet så kan vi synliggöra vad förvaltningsrätten tar fasta på som skäl för tvångsvård vid flickans egna beteende när det inte primärt handlar om kriminalitet eller missbruk. Studien utgår ifrån ett socialkonstruktionistiskt perspektiv med fokus på feministisk kritisk teori och teorin om sexuella script.

    Analysen har genomförts med hjälp av Carol Lee Bacchis diskursanalytiska verktyg ”What’s the problem represented to be?” där vi använt fem av de sex frågor som ingår i verktyget och formulerat om dessa för att passa vårt syfte. Dessa frågor lyder; 1) Hur framställs flickors sexualitet som ett problem?, 2) Vad underförstås och impliceras kring flickors sexualitet?, 3) Vilka följder får problemframställningarna och vilka subjekt konstrueras?, 4) Vad lämnas oproblematiserat när flickors sexualitet konstrueras som ett problem? samt 5) Hur skulle lösningen skilja sig om flickors sexualitet framställdes annorlunda? Den första och andra frågeställningen besvarade vi genom att kategorisera fram tre teman vilka innehöll tre framträdande diskurser; 1) Den vagabonderande flickan som ljuger, 2) Den sexuellt utåtagerande flickan och 3) Flickan som utsätter sig för risker. Med hjälp av dessa teman har vi kunnat besvara våra frågeställningar. Studiens resultat visar bland annat att problembilden som presenteras om flickorna handlar om att de frångår samhällets grundläggande normer genom att befinna sig i miljöer som inte anses lämpliga, att de har ett normbrytande sätt att uttrycka sin sexualitet på samt genom att ljuga och avvika från hemmet eller placeringar. Vi menar att detta konstruerande av flicknormen innebär ett begränsat handlingsutrymme och aktörskap för flickor att uttrycka sin sexualitet och ha rätt till självbestämmande. Tidigare studier visar att den vård som flickor många gånger hamnar i efter ett beslut om tvångsvård enligt LVU dessutom sällan har kunskaper för att hjälpa flickorna med de problem som antingen de själva eller samhället anser att de har.

  • Mohsen, Thaer
    Linköping University, Department of Behavioural Sciences and Learning.
    Ett kort studievägsval som påverkar livet: - Om lågutbildade invandrade kvinnors utbildningsstrategier2018Independent thesis Advanced level (degree of Master (Two Years)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Summary 

    The study examines the phenomenon of low educated immigrant women`s education strategies in choosing short vocational education and training programs. Women`s choises take place i relation to socal structures as well as local (family) as social and educational. The reality surrouding women is changing and unpredictable, which has both limiting and enabling effects om women`s actions. The essay also deals with women`s experience of their closest structures in relation to how the majority society/institutional society system looks at them. The study uses Bourdieu`s educational sociological theory of habitus, capital and field. The theory is the basis for the analysis of pronouncments that appear i open interviews. 

    The discussion of the outcome explains women`s educaton strategies as being guided by their inherited ways of being, feeling, thinking and acting - habitus. Women`s choice of healthcare opens up opportunities for them to free themselves both socially and economically, aswell as contribute to changes in social welfare and care. 

  • Ackerstierna, Joel
    et al.
    Linköping University, Department of Management and Engineering.
    Gullbrandsson, Marcus
    Linköping University, Department of Management and Engineering.
    Framtidens fastighetsbransch: PropTech och co-workings påverkan på kundvärdet i kontorslokaler: Identifikationen av de faktorer som möjliggör kundvärde och dess påverkan på tjänsteerbjudandet2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Problem definition: Digital innovation affects the world's economies and markets, where business-independent industry changes its way of working. The commercial real estate industry faces a change, where the two concepts of smart home and mobility change the appearance of the future market. On the market, there is an exponential increase in the number of companies utilizing the two concepts, companies collectively called PropTech companies, which act as catalysts for the transformation. Another trend is co-working, a new flexible office solution that utilizes the mobility change and disrupts the current value chain. These trends affect existing property managers, who should review their business model in view of the new technology to remain competitive. A major challenge with PropTech is the lack of understanding of the benefits it brings and what customer value it actually creates, making it difficult to create value offers that actually meet customer needs. The different types of PropTech and co-working provide a potential for new types of services that benefit the tenants in their business and can provide an easier work life balance.

    Purpose of the study: The purpose of this master thesis is to identify the impact PropTech and co-working has on commercial real estate tenants in Stockholm.

    Methodology: The study is of an exploratory character and aimed to explore what contributes to customer value for commercial tenants in Stockholm today and the impact PropTech and co-working has on it. The performance of the study was a combination of a cross-sectional approach, a qualitative, deductive and partly an inductive approach. A total of 16 semi-structured interviews were conducted, consisting of 11 property managers with internal management and five tenants working in the consulting industry. By interviewing tenants simultaneously with the property manager, it was established that the property managers' insight into the tenants' needs were in line with reality. The collected empirical data was analyzed on the basis of the applied reference framework and its factors that drive the customer value of tenants in office premises in Stockholm.

    Conclusions: The impact of digitization is of a complex nature and ranges from negative to positive aspects and everything in-between. The study identified four PropTech-services that can benefit company tenants in various ways and their impacts on customer value: property management, quantification & efficiency, office services and search platforms for working places. Co-working was also included as a service that affects customer value in office spaces.Identified factors creating customer value for company tenants were quality, adaptability, cost reduction and price. Each factor was further dissected to describe more accurately how it impacts tenants, these under factors consisted of tangibles, reliability, assurance, customer focus, co-creation, mass customization, flexibility, monetary costs, non-monetary costs, low cost and premium price.The study found that the most important aspect of property management, in order to have a positive impact on the tenants, is assurance. There also exists a potential positive impact for the service via non-monetary cost reductions. Furthermore, property management has a negative impact on customer focus and assurance. 

    The most important aspects of quantification & efficiency, in order to have a positive impact on the tenants, are tangibles, non-monetary cost reductions and flexibility. There also exists both a potential positive impact as well as a negligible impact for the service via monetary cost reductions.The most important aspect of office services, in order to have a positive impact on the tenants, is low price. There also exists a negligible impact for the service via non-monetary cost reductions.The most important aspects of search platforms for working places, in order to have a positive impact on the tenants, are flexibility and monetary cost reductions.The most important aspects of co-working, in order to have a positive impact on the tenants, are mass customization, flexibility and monetary cost reductions. There also exists a negative impact for the service via tangibles.The authors of this study encourage for further quantitative research regarding the subject.

  • Nilsson, Abraham
    et al.
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Orthopaedics in Linköping.
    Alkner, Björn
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Medicine and Health Sciences. Department of Orthopedics, Regional Hospital Eksjö, Region Jönköping County, Sweden.
    Wetterlöv, Patrick
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Medicine and Health Sciences. Department of Orthopedics, Regional Hospital Eksjö, Region Jönköping County, Sweden.
    Wetterstad, Stefan
    Department of Orthopedics, Region Hospital Kalmar, Kalmar, Sweden.
    Palm, Lars
    Linköping University, Department of Clinical and Experimental Medicine, Division of Surgery, Orthopedics and Oncology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Orthopaedics in Linköping.
    Schilcher, Jörg
    Linköping University, Department of Clinical and Experimental Medicine, Division of Surgery, Orthopedics and Oncology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Orthopaedics in Linköping.
    Low compartment pressure and myoglobin levels in tibial fractures with suspected acute compartment syndrome.2019In: BMC Musculoskeletal Disorders, ISSN 1471-2474, E-ISSN 1471-2474, Vol. 20, no 1, article id 15Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: The intense ischemic pain of acute compartment syndrome can be difficult to discriminate from the pain related to an associated fracture. Lacking objective measures, the decision to perform fasciotomy is often only based on clinical findings and performed at a low threshold. Biomarkers of muscle cell damage might help to identify and monitor patients at risk. In patients with fractures, however, markers of muscle cell damage could be elevated because of other reasons associated with the trauma, which would make interpretation difficult. In a review of all patients who underwent emergency fasciotomy in our health care district we aimed to investigate the decision-making process and specifically the use of biomarkers in patients with and without fractures.

    METHODS: In the southeast health care region of Sweden 79 patients (60 men) with fractures (median age 26 years) and 42 patients (34 men) without associated fractures (median age 44 years) were treated with emergency fasciotomy of the lower leg between 2007 and 2016. Differences in clinical findings, p-myoglobin and p-creatine phosphokinase as well as pressure measurements were investigated.

    RESULTS: P-myoglobin was analyzed preoperatively in 20% of all cases and p-creatine phosphokinase in 8%. Preoperative levels of p-myoglobin were lower in patients with fractures (median 1065 μg/L, range 200-3700 μg/L) compared with those without fractures (median 7450 μg/L, range 29-31,000 μg/L), p < 0.05. Preoperative intracompartmental pressure was lower in the fracture group (median 45 mmHg, range 25-90 mmHg) compared with those without fractures (median 83 mmHg, range 18-130 mmHg), p < 0.05.

    CONCLUSIONS: Biomarkers are seldom used in the context of acute fasciotomy of the lower leg. Contrary to our expectations, preoperative levels of p-myoglobin and intracompartmental pressures were lower in fracture patients. These findings support differences in the underlying pathomechanism between the groups and indicate that biomarkers of muscle cell necrosis might play a more important role in the diagnosis of acute compartment syndrome than previously thought.

  • Lindgren, Marcus
    Linköping University, Department of Behavioural Sciences and Learning.
    Verklighets- och vardagskontexter i textuppgifter: Hur kan Lärare påverka och välja ut rätt kontexter för sina elever?2017Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Syftet med denna litteraturstudie var att undersöka vilken roll vardagskontexter och verklighetsbaserade kontexter spelar för hur elever förstår uppgifter i matematiken. Arbetet syftar även till att undersöka hur läraren kan använda sig av språk och kontexter för att underlätta elevers förståelse i matematiken. Den teoretiska bakgrund som arbetet utgår ifrån är Bronfenbrenners utvecklingsekologiska modell. Artikelinsamlingen har gjorts via Unisearch. Resultatdelen visar att olika kulturer och vardagsbakgrunder kan spela in i hur elever tolkar kontexter. Läraren som känner sina elever väl blir därför mycket viktig när det kommer till att välja ut och anpassa uppgifter som passar sina elever då hen vet vad som ligger nära eleverna.

  • Eriksson, Oskar
    Linköping University, Department of Computer and Information Science, Software and Systems.
    Evaluation of BizTalk360: From a business value perspective2019Independent thesis Basic level (degree of Bachelor), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [en]

    This thesis was requested by Solution Xperts in Linköping and is an evaluation of the software BizTalk360, which is a add-on to the very well known application integration software BizTalk Server. One problem that many face with BizTalk Server is how to handle the post-implementation operations of their implementation. Referring to such factors as monitoring and security for instance. The built-in tools are very limited and lack a variety of functions that are very desirable. BizTalk360 tries to solve this. In order to evaluate the value that BizTalk360 brings to its users, two factors were taken into account. How important are the functions provided for the company? And how difficult would these be to implement independently?. After testing the BizTalk360 core functions and features and also implementing a representative function of BizTalk360, everything learnt were presented to group of experienced BizTalk Sever developers in order to receive estimates regarding their individual importance and theoretical implementation time. The importance of the functions proved quite minor. The platform offers a lot of smart solutions to various problems but these wont see enough use to justify the cost. The difficulty of implementing a similar platform were also estimated to be quite low, only time consuming. Estimated to take (through average) 653 man hours.

  • Brüggemann, Jelmer
    et al.
    Linköping University, Department of Thematic Studies, Technology and Social Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Department of Clinical and Experimental Medicine, Division of Children's and Women's health. Linköping University, Faculty of Medicine and Health Sciences.
    Persson, Alma
    Linköping University, Department of Thematic Studies, The Department of Gender Studies. Linköping University, Faculty of Arts and Sciences. Linköping University, Department of Clinical and Experimental Medicine, Division of Children's and Women's health. Linköping University, Faculty of Medicine and Health Sciences.
    Wijma, Barbro
    Linköping University, Department of Clinical and Experimental Medicine, Division of Children's and Women's health. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center of Paediatrics and Gynaecology and Obstetrics, Department of Gynaecology and Obstetrics in Linköping.
    Understanding and preventing situations of abuse in health care: Navigation work in a Swedish palliative care setting2019In: Social Science and Medicine, ISSN 0277-9536, E-ISSN 1873-5347, Vol. 222, p. 52-58Article in journal (Refereed)
    Abstract [en]

    In their everyday work, health professionals find themselves in situations that they perceive to be abusive to patients. Such situations can trigger feelings of shame and guilt, making efforts to address the problem among colleagues a challenge. This article analyzes how health professionals conceptualize abusive situations, and how they develop collective learning and explore preventive strategies. It is based on an interactive research collaboration with a hospice and palliative care clinic in Sweden during 2016–2017. The empirical material consists of group discussions and participant observations collected during interactive drama workshops for all clinic staff. Based on three types of challenges in the material, identified through thematic analysis, we establish the concept of navigation work to show how health professionals prevent or find ways out of challenging and potentially abusive situations. First, the navigation of care landscapes shows how staff navigate the different territories of the home and the ward, reflecting how spatial settings construct the scope of care and what professionals consider to be potentially abusive situations. Second, the negotiation of collective navigations addresses the professionals' shared efforts to protect patients through the use of physical and relational boundaries, or mediating disrupted relationships. Third, the navigation of tensions in care highlights professionals’ strategies in the confined action space between coercing and neglecting patients who oppose necessary care procedures. Theoretically, the concept of navigation work draws upon work on care in practice, and sheds light on the particular kind of work care professionals do, and reflect on doing, in order to navigate the challenges of potentially abusive situations. By providing a perspective and shared vocabulary, the concept may also elicit ways in which this work can be verbalized, shared, and developed in clinical practice.

  • Mollén, Christopher
    et al.
    Linköping University, Department of Electrical Engineering, Communication Systems. Linköping University, Faculty of Science & Engineering. Ericsson, Sweden; Ericsson, Peoples R China; Eidgenoss TH Zurich, Switzerland; Univ Texas Austin, TX 78712 USA; Apple, CA 92307 USA.
    Gustavsson, Ulf
    Ericsson Res, Sweden.
    Eriksson, Thomas
    Chalmers Univ Technol, Sweden.
    Larsson, Erik G
    Linköping University, Department of Electrical Engineering, Communication Systems. Linköping University, Faculty of Science & Engineering.
    Impact of Spatial Filtering on Distortion From Low-Noise Amplifiers in Massive MIMO Base Stations2018In: IEEE Transactions on Communications, ISSN 0090-6778, E-ISSN 1558-0857, Vol. 66, no 12, p. 6050-6067Article in journal (Refereed)
    Abstract [en]

    In massive multiple-input-multiple-output base stations, power consumption and cost of the low-noise amplifiers (LNAs) can be substantial because of the many antennas. We investigate the feasibility of inexpensive, power efficient LNAs, which inherently are less linear. A polynomial model is used to characterize the nonlinear LNAs and to derive the second-order statistics and spatial correlation of the distortion. We show that, with spatial matched filtering (maximum-ratio combining) at the receiver, some distortion terms combine coherently, and that the signal-to-interference-and-noise ratio of the symbol estimates therefore is limited by the linearity of the LNAs. Furthermore, it is studied how the power from a blocker in the adjacent frequency band leaks into the main band and creates distortion. The distortion term that scales cubically with the power received from the blocker has a spatial correlation that can be filtered out by spatial processing and only the coherent term that scales quadratically with the power remains. When the blocker is in free-space line-of-sight and the LNAs are identical, this quadratic term has the same spatial direction as the desired signal, and hence cannot be removed by linear receiver processing.

  • Public defence: 2019-02-08 09:00 Berzeliussalen, Linköping
    Kalsum, Sadaf
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Characterizing phenotypes of Mycobacterium tuberculosis and exploring anti-mycobacterial compounds through high content screening2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Tuberculosis (TB), an airborne disease and one of the top 10 causes of death globally, is caused by Mycobacterium tuberculosis (Mtb). Current standard therapy for TB treatment includes multiple drugs for a period of at least 6 months. The long therapy duration is to sterilize a small sub-population of drug-tolerant bacteria, a characteristic related to biofilm formation, which otherwise responsible for disease relapse. On the other hand, because of such a long treatment period, patient adherence to therapy becomes difficult, which results in the emergence of multidrug-resistant (MDR) or, in worst cases, extensively drug-resistant (XDR)-TB. TB is primarily a disease of lungs and alveolar macrophages are one of the first host cell types to encounter Mtb following aerosol transmission. A well-established role of macrophages in immune defense is phagocytosis, but recent studies also demonstrated that upon interaction with large aggregates of microbes or cord-forming mycobacterial species, macrophages could produce extracellular traps known as macrophage extracellular traps (METs). METs have a DNA backbone with embeds histones and could trap a wide range of microorganisms, but may or may not be able to kill them. Natural products are always a promising starting point for drug discovery because of their wide range of activity. A large number of world’s population is still using extracts from different parts of plants as the primary source of medicines against diseases including TB. Today much effort is being invested by academia in screening campaigns that allows for fast discovery of new active compounds. Thanks to the use of automated technology such as automated microscopy or automated image analysis (known as high content screening, HCS) phenotypic drug discovery has become easier to perform. Therefore, the identification of highly effective compounds to combat infectious diseases like TB can be facilitated by the use of host-pathogen assays at the early stages of drug screening studies.

    This thesis describes the characterization and antibiotic sensitivity of different phenotypes of Mtb namely planktonic, cord-forming and biofilm-producing phenotypes that arise due to different culture conditions. The culture of Mtb with a high percentage of a detergent (Tween-80) and standing condition promoted planktonic phenotype while a culture with a low amount of Tween-80 and more aeration due to shaking promoted cording and biofilm phenotypes. Primary human macrophages upon interaction with the shaken culture of wild-type Mtb died by releasing METs. Whereas, the shaken cultures of early secreted antigenic target-6 (ESAT-6), an important virulence factor of Mtb, deletion mutant strain could not induce MET formation showing that the cord formation is related to virulence. Moreover, the biofilm phenotype of Mtb is more tolerant to two first-line antibiotics isoniazid (INH) and rifampicin (RIF) as compared to cording and planktonic phenotypes which demand a search of more effective TB therapy. A screening campaign based on a whole-cell assay using different ethanolic crude extracts of many African plants lead to the discovery of a hit, i.e., a chloroform fraction of Khaya senegalensis bark, which showed non-significant inhibition of intracellular growth of a virulent strain of Mtb was selected for further purification and evaluation. Lastly, we have also developed and validated an HCS assay to explore new compounds against intracellular Mtb in human macrophages. INH and RIF, which were found most effective in our system were used in a combination as a positive control to calculate a Z’ factor value, which confirmed our assay to be suitable for HCS.

    In conclusion, this thesis not only highlights the biology of TB infection, but also discusses the development of a pathophysiologically relevant assay that can be used in the identification of novel compound(s) that has either direct anti-mycobacterial activity (antibiotic), acts by stimulating the host cell immune mechanisms (immunomodulator) or acts by counteracting virulence factors (virulence blocker).  

    List of papers
    1. The Cording Phenotype of Mycobacterium tuberculosis Induces the Formation of Extracellular Traps in Human Macrophages
    Open this publication in new window or tab >>The Cording Phenotype of Mycobacterium tuberculosis Induces the Formation of Extracellular Traps in Human Macrophages
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    2017 (English)In: Frontiers in Cellular and Infection Microbiology, E-ISSN 2235-2988, Vol. 7, article id 278Article in journal (Refereed) Published
    Abstract [en]

    The causative agent of tuberculosis, Mycobacterium tuberculosis, shares several characteristics with organisms that produce biofilms during infections. One of these is the ability to form tight bundles also known as cords. However, little is known of the physiological relevance of the cording phenotype. In this study, we investigated whether cord-forming M. tuberculosis induce the formation of macrophage extracellular traps (METs) in human monocyte-derived macrophages. Macrophages have previously been shown to produce extracellular traps in response to various stimuli. We optimized bacterial culturing conditions that favored the formation of the cord-forming phenotype as verified by scanning electron microscopy. Microscopy analysis of METs formation during experimental infection of macrophages with M. tuberculosis revealed that cord-forming M. tuberculosis induced significantly more METs compared to the non-cording phenotype. Deletion of early secreted antigenic target-6 which is an important virulence factor of M. tuberculosis, abrogated the ability of the bacteria to induce METs. The release of extracellular DNA from host cells during infection may represent a defense mechanism against pathogens that are difficult to internalize, including cord-forming M. tuberculosis.

    Place, publisher, year, edition, pages
    FRONTIERS MEDIA SA, 2017
    Keywords
    Mycobacterium tuberculosis; macrophage extracellular traps (METs); cording; Tween-80; virulence; early secreted antigenic target-6 (ESAT-6)
    National Category
    Microbiology in the medical area
    Identifiers
    urn:nbn:se:liu:diva-139276 (URN)10.3389/fcimb.2017.00278 (DOI)000404073500001 ()
    Note

    Funding Agencies|Swedish Research Council [2012-3349, 2015-02593]; Swedish Heart Lung Foundation [20130685, 20150709]

    Available from: 2017-07-07 Created: 2017-07-07 Last updated: 2019-01-07
    2. Antimycobacterial activity of selected medicinal plants traditionally used in Sudan to treat infectious diseases
    Open this publication in new window or tab >>Antimycobacterial activity of selected medicinal plants traditionally used in Sudan to treat infectious diseases
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    2014 (English)In: Journal of Ethnopharmacology, ISSN 0378-8741, E-ISSN 1872-7573, Vol. 157, p. 134-139Article in journal (Refereed) Published
    Abstract [en]

    Ethnopharmacological relevance: The emergence of multidrug-resistant strains of Mycobacterium tuberculosis underscores the need for continuous development of new and efficient methods to determine the susceptibility of isolates of Mycobacterium tuberculosis in the search for novel antimycobacterial agents. Natural products constitute an important source of new drugs, and design and implementation of antimycobacterial susceptibility testing methods are necessary to evaluate the different extracts and compounds. In this study we have explored the antimycobacterial properties of 50 ethanolic extracts from different parts of 46 selected medicinal plants traditionally used in Sudan to treat infectious diseases. Materials and methods: Plants were harvested and ethanolic extracts were prepared. For selected extracts, fractionation with hydrophilic and hydrophobic solvents was undertaken. A luminometry-based assay was used for determination of mycobacterial growth in broth cultures and inside primary human macrophages in the presence or absence of plant extracts and fractions of extracts. Cytotoxicity was also assessed for active fractions of plant extracts. Results: Of the tested extracts, three exhibited a significant inhibitory effect on an avirulent strain of Mycobacterium tubercluosis (H37Ra) at the initial screening doses (125 and 6.25 mu g/ml). These were bark and leaf extracts of Khaya senegalensis and the leaf extract of Rosmarinus officinalis L. Further fractions of these plant extracts were prepared with n-hexane, chloroform, ethyl acetate, n-butanol, ethanol and water, and the activity of these extracts was retained in hydrophobic fractions. Cytotoxicity assays revealed that the chloroform fraction of Khaya senegalensis bark was non-toxic to human monocyte-derived macrophages and other cell types at the concentrations used and hence, further analysis, including assessment of IC50 and intracellular activity was done with this fraction. Conclusion: These results encourage further investigations to identify the active compound(s) within the chloroform fraction of Khaya senegalensis bark. (C) 2014 Elsevier Ireland Ltd. All rights reserved.

    Place, publisher, year, edition, pages
    Elsevier, 2014
    Keywords
    Mycobacterium tuberculosis; Sudanese medicinal plants; Primary human macrophages; Luminescence reporter assay; Cytotoxicity assay
    National Category
    Clinical Medicine
    Identifiers
    urn:nbn:se:liu:diva-113785 (URN)10.1016/j.jep.2014.09.020 (DOI)000347022700016 ()25261689 (PubMedID)
    Note

    Funding Agencies|Ekhaga Foundation [2011-33]; Swedish Insitute

    Available from: 2015-02-02 Created: 2015-01-30 Last updated: 2019-01-07
  • Public defence: 2019-02-15 13:00 Hugo Theorell-salen, Linköping
    Trzebiatowska-Krzynska, Aleksandra
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    The right ventricle in volume or pressure overload: Insights from novel imaging techniques2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This study is inspired by the gap in knowledge regarding the timing of cardiac surgery and interventions in adult patients with congenital heart disease. There are many parameters used assessing right ventricular function; however, most of them have pitfalls. Understanding the pathomechanisms by which the heart adapts to congenital defects is probably key to find the answer when it is time to intervene and start discussing treatment options. Heart defects are the most frequently occurring congenital disorders. Less than 50% of individuals with moderate to severe congenital heart defects, e.g. transposition of the great arteries (TGA) or tetralogy of Fallot (TOF), survive to adulthood without intervention. Advances in cardiac surgery and better identification of individuals at risk for sudden cardiac death have increased survival rates. Currently, more than 96% of patients with congenital heart disease survive to at least 16 years of age; most undergo corrective surgery but are not cured, and only a few have normal physiology and anatomy. In many cases, the heart must develop mechanisms of adaptation to the changed conditions after surgery. Consequently, correction of the defect creates residual disease with a risk of future complications.

    To prevent clinical deterioration and to identify the development of complications, patients need lifelong, regular follow up. The choice of followup modalities depends on the cardiac malformation.

    The right ventricle (RV) plays an important role, as it is often part of the defect or is influenced by the surgery. In the past, research was focused on assessment of left ventricular function (LV), and the RV was “the forgotten ventricle.” Observations and studies in the last few decades brought increased interest into the RV and revealed the importance of the RV in the prognosis of various cardiac diseases.

    An understanding of RV morphology, pathophysiology and adaptive mechanisms is crucial for further studies of prognosis as well as for research linked to the use of particular diagnostic modalities.

    When the RV is exposed to increased pressure load, e.g. in atrially corrected transposition of the great arteries (TGA), adaptation affects the cavity volume as well as the wall thickness. When the RV is volume overloaded, adaptation involves enhancement of the RV cavity volume while the wall thickness often remains unchanged under long time. RV ejection fraction (RVEF) gives some information about changes in RV function, but information on myocardial contractility and contractile reserve is also needed. New functional parameters such as strain—also known as myocardial deformation—provide some information about intrinsic myocardial function.

    In Paper I, we studied functional parameters such as ejection fraction and strain (radial and longitudinal strain for both ventricles) in patients with Tetralogy of Fallot (TOF) and TGA. Longitudinal RV strain was depressed in both patient groups in comparison with that in healthy individuals, and there were additional differences between the two patient groups.

    In Paper II, we validated three-dimensional echocardiography (3DEcho) against the cardiac magnetic resonance (CMR) gold standard. The study population was limited to patients with TOF. In general, 3DEcho underestimated RV volumes but was able to identify patients with RV dilatation on CMR with high sensitivity. RV longitudinal free wall strain measured by CMR with a cut-off set at -14% identified patients with depressed exercise capacity and low peak oxygen uptake.

    In Paper III, we studied a new CMR method to quantify and visualise turbulent flow in the heart and vessels. Turbulent flow can be harmful to tissue, blood cells, and endothelium and can contribute to tissue remodeling. In patients with TOF, turbulent flow can be seen as variance in 2DEcho color Doppler. In CMR, increased turbulent kinetic energy (TKE) could be seen with four-dimensional flow. The RV TKE was increased in patients with TOF with pulmonary regurgitation compared with that in healthy controls.

    In Paper IV, we validated “knowledge-based reconstruction” (KBR), a novel method to calculate RV volume, against CMR in patients with various types of congenital heart defects. Two-dimensional echocardiogram-based threedimensional RV reconstruction is a relatively uncomplicated method that creates a three-dimensional RV model based on a limited number of predefined points of interest (RV structures such as tricuspid annulus, RV free wall, or pulmonary valve).

    KBR showed good agreement with CMR (intraclass correlation coefficient = 0.84 for RV end-diastolic volume and 0.89 for ejection fraction) but tended to underestimate RV volumes, which is in line with other methods based on ultrasound.

    Conclusions: 3DEcho is an evolving modality that is able to identify patients with RV dilatation. It can be used clinically for the follow up of patients with congenital heart diseases, especially those with mildly to moderately dilated RVs. When an intervention seems likely, 3DEcho results should be verified by CMR. CMR-derived measurements of longitudinal and radial strain provide a new understanding of RV remodeling and ventricular interdependence in patients with TOF and TGA. Depressed longitudinal strain may indicate a risk of depressed exercise capacity and, in patients with TGA, clinical deterioration.

    Further studies in larger populations of patients with congenital heart defects are needed, as the altered RV morphology in such patients makes quantitative assessment especially challenging.

    List of papers
    1. Afterload dependence of right ventricular myocardial deformation: A comparison between tetralogy of Fallot and atrially corrected transposition of the great arteries in adult patients
    Open this publication in new window or tab >>Afterload dependence of right ventricular myocardial deformation: A comparison between tetralogy of Fallot and atrially corrected transposition of the great arteries in adult patients
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    2018 (English)In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 13, no 9, article id e0204435Article in journal (Refereed) Published
    Abstract [en]

    Background

    Prior studies suggested that myocardial deformation is superior to conventional measures for assessing ventricular function. This study aimed to evaluate right ventricular (RV) myocardial deformation in response to increased afterload. Patients with the RV in the systemic position were compared with patients with the RV in the sub-pulmonic position with normal or only slightly elevated systolic right ventricular pressure. Correlations between global longitudinal strain (GLS), radial strain, atrioventricular plane displacement (AVPD), and exercise capacity were evaluated.

    Methods

    44 patients with congenital heart defect were enrolled in the study. The control group consisted of seven healthy volunteers. All patients underwent cardiovascular magnetic resonance (CMR) and cardiopulmonary exercise testing. We assessed biventricular myocardial function using CMR based feature tracking and compared the results to anatomic volumes.

    Results

    Strain analysis and displacement measurements were feasible in all participants. RVGLS and RVAVPD were reduced in both study groups compared to the control group (p<0.001). Left ventricular (LV) radial strain was significantly lower in patients with a systemic RV than in those with a subpulmonic RV and lower than in controls (p<0.001). Both LVAVPD and RVAVPD were significantly depressed in patients compared to controls (p<0.05). RVAVPD was more depressed in patients with a high systolic RV pressure than in those with normal RV pressure (p<0.001). RVAVPD did not correlate with exercise capacity in either study group. Exercise capacity in both patient groups was depressed to levels reported in previous studies, and did not correlate with RVGLS.

    Conclusions

    Both study groups had abnormal myocardial deformation and increased RV volumes. RVGLS in patients was lower than in controls, confirming the effect of increased afterload on myocardial performance.

    Place, publisher, year, edition, pages
    San Francisco, CA, United States: Public Library of Science, 2018
    National Category
    Cardiac and Cardiovascular Systems
    Identifiers
    urn:nbn:se:liu:diva-152085 (URN)10.1371/journal.pone.0204435 (DOI)000445907400049 ()30261015 (PubMedID)2-s2.0-85054059580 (Scopus ID)
    Note

    Funding Agencies|ALF Grant, Region Ostergotland [LIO-281281]

    Available from: 2018-10-17 Created: 2018-10-17 Last updated: 2019-01-07Bibliographically approved
    2. Turbulent kinetic energy in the right ventricle: Potential MR marker for risk stratification of adults with repaired Tetralogy of Fallot
    Open this publication in new window or tab >>Turbulent kinetic energy in the right ventricle: Potential MR marker for risk stratification of adults with repaired Tetralogy of Fallot
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    2018 (English)In: Journal of Magnetic Resonance Imaging, ISSN 1053-1807, E-ISSN 1522-2586, Vol. 47, no 4, p. 1043-1053Article in journal (Refereed) Published
    Abstract [en]

    Purpose: To assess right ventricular (RV) turbulent kinetic energy (TKE) in patients with repaired Tetralogy of Fallot (rToF) and a spectrum of pulmonary regurgitation (PR), as well as to investigate the relationship between these 4D flow markers and RV remodeling.

    Materials and Methods: Seventeen patients with rToF and 10 healthy controls were included in the study. Patients were divided into two groups based on PR fraction: one lower PR fraction group (11%) and one higher PR fraction group (>11%). Field strength/sequences: 3D cine phase contrast (4D flow), 2D cine phase contrast (2D flow), and balanced steady-state free precession (bSSFP) at 1.5T. Assessment: The RV volume was segmented in the morphologic short-axis images and TKE parameters were computed inside the segmented RV volume throughout diastole. Statistical tests: One-way analysis of variance with Bonferroni post-hoc test; unpaired t-test; Pearson correlation coefficients; simple and stepwise multiple regression models; intraclass correlation coefficient (ICC).

    Results: The higher PR fraction group had more remodeled RVs (140 6 25 vs. 107 6 22 [lower PR fraction, P < 0.01] and 93 6 15 ml/m2[healthy, P < 0.001] for RV end-diastolic volume index [RVEDVI]) and higher TKE values (5.95 6 3.15 vs. 2.23 6 0.81 [lower PR fraction, P < 0.01] and 1.91 6 0.78 mJ [healthy, P < 0.001] for Peak Total RV TKE). Multiple regression analysis between RVEDVI and 4D/2D flow parameters showed that Peak Total RV TKE was the strongest predictor of RVEDVI (R25 0.47, P 5 0.002).

    Conclusion: The 4D flow-specific TKE markers showed a slightly stronger association with RV remodeling than conventional 2D flow PR parameters. These results suggest novel hemodynamic aspects of PR in the development of late complications after ToF repair.

    Place, publisher, year, edition, pages
    Hoboken: John Wiley & Sons, 2018
    Keywords
    4D flow, MRI, Turbulence, Tetralogy of Fallot, Turbulent kinetic energy
    National Category
    Radiology, Nuclear Medicine and Medical Imaging Cardiac and Cardiovascular Systems Medical Laboratory and Measurements Technologies Anesthesiology and Intensive Care Medical Image Processing
    Identifiers
    urn:nbn:se:liu:diva-143780 (URN)10.1002/jmri.25830 (DOI)000427125300016 ()28766919 (PubMedID)2-s2.0-85026745981 (Scopus ID)
    Note

    Funding agencies:  European Research Council [310612]; Swedish Heart and Lung Foundation [20140398]; County Council of Ostergotland; Medical Research Council of Southeast Sweden (FORSS); Swedish Research Council [2013-6077, 2014-6191]

    Available from: 2017-12-18 Created: 2017-12-18 Last updated: 2019-01-07Bibliographically approved
    3. Knowledge-based 3D reconstruction of the right ventricle: comparison with cardiac magnetic resonance in adults with congenital heart disease
    Open this publication in new window or tab >>Knowledge-based 3D reconstruction of the right ventricle: comparison with cardiac magnetic resonance in adults with congenital heart disease
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    2015 (English)In: Echo research and practice, ISSN 2055-0464, Vol. 2, no 4, p. 109-116Article in journal (Refereed) Published
    Abstract [en]

    AIM: Assessment of right ventricular (RV) function is a challenge, especially in patients with congenital heart disease (CHD). The aim of the present study is to assess whether knowledge-based RV reconstruction, used in the everyday practice of an echo-lab for adult CHD in a tertiary referral center, is accurate when compared to cardiac magnetic resonance (CMR) examination.

    SUBJECTS AND METHODS: Adult patients who would undergo CMR for assessment of the RV were asked to undergo an echo of the heart for further knowledge-based reconstruction (KBR). Echocardiographic images were acquired in standard views using a predefined imaging protocol. RV volumes and ejection fraction (EF) calculated using knowledge-based technology were compared with the CMR data of the same patient.

    RESULTS: Nineteen consecutive patients with congenital right heart disease were studied. Median age of the patients was 28 years (range 46 years). Reconstruction was possible in 16 out of 19 patients (85%). RV volumes assessed with this new method were smaller than with CMR. Indexed end diastolic volumes were 114±17 ml vs 121±19 ml, P<0.05 and EFs were 45±8% vs 47±9%, P<0.05 respectively. The correlation between the methods was good with an intraclass correlation of 0.84 for EDV and 0.89 for EF, P value <0.001 in both cases.

    CONCLUSION: KBR enables reliable measurement of RVs in patients with CHDs and can be used in clinical practice for analysis of volumes and EFs.

    Keywords
    congenital heart disease; knowledge-based reconstruction; right ventricle volume; ventripoint system
    National Category
    Cardiac and Cardiovascular Systems
    Identifiers
    urn:nbn:se:liu:diva-124289 (URN)10.1530/ERP-15-0029 (DOI)26796613 (PubMedID)
    Available from: 2016-01-25 Created: 2016-01-25 Last updated: 2019-01-07
  • Ronsten, Linnéa
    et al.
    Linköping University, Department of Behavioural Sciences and Learning.
    Qvist, Fredrik
    Linköping University, Department of Behavioural Sciences and Learning.
    Hur kommunicerar elever vid problemlösning i matematik?: Kommunikation mellan elever och faktorer som påverkar kommunikationen2018Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Syftet med denna litteraturstudie var att undersöka vad forskning säger om elevers kommunikation vid problemlösning i matematik och vilka faktorer som påverkar kommunikationen. Problemlösning har gett människan många verktyg som vi idag ser som livsviktiga och för att utveckla samhället ytterligare behöver skolan utbilda kompetenta problemlösare. Genom att söka i databaserna ERIC, MathEduc och allt-i-ett-söktjänsten UniSearch samt leta manuellt i referenslistor hittades data för den här litteraturstudien. Resultatet visar att elever som kommunicerar väl ser varandras idéer som gemensamma resurser. För det ska vara möjligt krävs att eleverna får undervisning i vad det innebär och att de arbetar med rätt uppgiftstyp.

  • Eliasson, Karin
    Linköping University, Department of Thematic Studies, Tema Environmental Change.
    Spatially explicit nitrogen and phosphorus footprinting: Linking consumption activities to nutrient leaching risk for Brazilian soy production2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    An increasing demand for food, and in particular animal products, is putting high pressure on natural resources, often at places distant from the consumption. Nitrogen and phosphorus are essential nutrients in food production but an excessive use can cause environmental impacts such as eutrophication that can harm ecosystems services vital to local communities. This study developed sub-national spatially explicit N and P footprints that were extended with an assessment of nutrient leaching risk and risk of impact on biodiversity. The consumption of N and P in Brazilian soybean production at municipal level was estimated for the whole of Brazil as well as for UK soybean demand. This was then combined with the risk of nutrient leaching (Nrisk and Prisk) and species richness (Nbio and Pbio). The results showed high Nbio and Pbio in Mato Grosso, Paraná, and Rio Grande do Sul. The same analysis of the effects of UK soybean demand showed a higher risk of impacts in Rondônia and less in Paraná and Rio Grande do Sul compared to total Brazilian soybean production. A municipal case study showed that the demand of Brazilian soybean in the UK, EU, and China generated different spatial patterns of impact risks at municipal level. Spatially explicit footprints that also encompass risks of impacts are important for being able to identify the responsible consumer and parts of the supply chain where sustainability interventions will be most effective. There are several opportunities for future development within this research field as data availability is continuingly increasing.

  • Public defence: 2019-01-31 13:15 John von Neumann, B-huset, Linköping
    Touqir Pasha, Muhammad
    Linköping University, Department of Electrical Engineering, Integrated Circuits and Systems. Linköping University, Faculty of Science & Engineering.
    All-Digital PWM Transmitters2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Electronic devices with wireless connectivity are fast becoming a part of daily life. According to some estimates, in the next five years, 10 billion new devices with internet connectivity would be produced. To lower the costs and extend the battery life of electronic circuits, there is an increased interest in using lowcost, low-power CMOS circuits. By taking advantage of the higher integration capabilities of modern CMOS, the analog, digital, and radio circuits can be integrated on a single die, typically called a radio-frequency system-on-chip (RF-SoC).

    In an RF-SoC, most of the power is usually consumed by the radio circuits, especially the power amplifier (PA). Hence, to take advantage of the improved switching capability of transistors in modern CMOS, the use of switch-mode PAs (SMPAs) is becoming more popular. SMPAs exhibit a much higher efficiency as compared to their linear counterparts and can be easily integrated with the digital baseband circuits.

    To satisfy the demand for higher data throughput, modern wireless standards like LTE and IEEE 802.11 generate envelope-varying signals using advanced modulation schemes like M-QAM and OFDM. Among several other techniques, pulse-width modulation (PWM) allows for the amplification of the envelopevarying signals using SMPAs.

    The first part of this thesis explores techniques to improve the spectral performance of PWM-based transmitters. The proposed transmitters are fully digital, and the entire signal chain up to the PA can be implemented using the digital design flow, which is especially beneficial in sub-micron CMOS processes with low voltage headroom. A new transmitter is proposed that compensates for the aliasing distortion in polar PWM transmitters by using outphasing. The transmitter exhibits an improvement of up to 9 dB in dynamic range for a 1.4 MHz LTE uplink signal. The idea is extended to compensate for both image and aliasing distortions in all-digital implementations of polar PWM transmitters. By using a field programmable gate array (FPGA) and Class-D SMPAs, the proposed transmitter shows an improvement of up to 6.9 dBc in the adjacent channel leakage ratio (ACLR) and 10% in the error vector magnitude (EVM) for a 20 MHz LTE uplink signal. The proposed transmitter is fully programmable and can be easily adapted for multi-band and multi-standard transmission.

    To enhance the phase linearity of all-digital PWM transmitters, a new transmitter architecture based on outphasing is presented. The proposed transmitter uses outphasing to improve the phase resolution and exhibits an improvement of 2.8 dBc and 3.3% in ACLR and EVM, respectively.

    The difference between the polar and quadrature implementations of RFPWM based transmitters is explored. By using mathematical derivations and simulations, it is shown that the polar implementation outperforms the quadrature implementation due to the lower quantization noise. An RF-PWM based transmitter that eliminates both image and aliasing distortions is presented. The proposed transmitter has an all-digital implementation, uses a single SMPA, and eliminates the need for a power combiner resulting in a more compact design. For a 1.4 MHz LTE uplink signal, the proposed transmitter exhibits an improvement of up to 11.3 dBc in ACLR.

    The second part of this work focuses on the design of all-digital area-efficient architectures of time-to-digital converters (TDCs). A TDC is essentially a stopwatch with a pico-second resolution and can be used to accurately quantify the pulse width and position of PWM signals.

    A Vernier delay line-based TDC is presented that replaces the conventionally used sampling D flip-flops by a single transistor. This resulting implementation does not suffer from blackout time associated with D flip-flops allowing for a more compact design. The proposed TDC achieves a time resolution of 5.7 ps, and consumes 1.85 mW of power while operating at 50 MS/s.

    A modified switching scheme to reduce the power consumed by the thermometerto- binary encoder used in the TDCs is presented. By taking advantage of the operating nature of the TDCs, the proposed switching scheme reduces the power consumption by up to 40% for a 256-bit encoder.

    List of papers
    1. Aliasing-Compensated Polar PWM Transmitter
    Open this publication in new window or tab >>Aliasing-Compensated Polar PWM Transmitter
    2017 (English)In: IEEE Transactions on Circuits and Systems - II - Express Briefs, ISSN 1549-7747, E-ISSN 1558-3791, Vol. 64, no 8, p. 912-916Article in journal (Refereed) Published
    Abstract [en]

    This paper presents a novel pulse-width modulation (PWM) transmitter architecture that compensates for aliasing distortion by combining PWM and outphasing. The proposed transmitter can use either switch-mode PAs (SMPAs) or linear PAs at peak power, ensuring maximum efficiency. The transmitter shows better linearity, improved spectral performance and increased dynamic range compared to other polar PWM transmitters as it does not suffer from AM-AM distortion of the PAs and aliasing distortion due to digital PWM. Measurement results show that the proposed architecture achieves an improvement of 8 dB and 4 dB in the dynamic range compared to the digital polar PWM transmitter (PPWMT) and the aliasing-free PWM transmitter (AF-PWMT), respectively. The proposed architecture also shows better efficiency compared to the AF-PWMT.

    Place, publisher, year, edition, pages
    IEEE, 2017
    National Category
    Electrical Engineering, Electronic Engineering, Information Engineering
    Identifiers
    urn:nbn:se:liu:diva-136819 (URN)10.1109/TCSII.2016.2614433 (DOI)000407087200012 ()
    Available from: 2017-04-27 Created: 2017-04-27 Last updated: 2019-01-07
    2. A Modified All-Digital Polar PWM Transmitter
    Open this publication in new window or tab >>A Modified All-Digital Polar PWM Transmitter
    2018 (English)In: IEEE Transactions on Circuits and Systems Part 1: Regular Papers, ISSN 1549-8328, E-ISSN 1558-0806, Vol. 65, no 2, p. 758-768Article in journal (Refereed) Published
    Abstract [en]

    This paper presents an all-digital polar pulsewidth modulated (PWM) transmitter for wireless communications. The transmitter combines baseband PWM and outphasing to compensate for the amplitude error in the transmitted signal due to aliasing and image distortion. The PWM is implemented in a field programmable gate array (FPGA) core. The outphasing is implemented as pulse-position modulation using the FPGA transceivers, which drive two switch-mode power amplifiers fabricated in 130-nm standard CMOS. The transmitter has an all-digital implementation that offers the flexibility to adapt it to multi-standard and multi-band signals. As the proposed transmitter compensates for aliasing and image distortion, an improvement in the linearity and spectral performance is observed as compared with a digital-PWM transmitter. For a 20-MHz LTE uplink signal, the measurement results show an improvement of up to 6.9 dBc in the adjacent channel leakage ratio.

    Place, publisher, year, edition, pages
    IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2018
    Keywords
    Software-defined radio (SDR); CMOS; FPGA; switch-mode PA (SMPA); outphasing; polar pulse-width modulation (P-PWM); aliasing distortion; image distortion; LTE
    National Category
    Other Electrical Engineering, Electronic Engineering, Information Engineering
    Identifiers
    urn:nbn:se:liu:diva-145245 (URN)10.1109/TCSI.2017.2725980 (DOI)000423559000029 ()
    Available from: 2018-03-07 Created: 2018-03-07 Last updated: 2019-01-07
    3. An All-Digital PWM Transmitter With Enhanced Phase Resolution
    Open this publication in new window or tab >>An All-Digital PWM Transmitter With Enhanced Phase Resolution
    2018 (English)In: IEEE Transactions on Circuits and Systems - II - Express Briefs, ISSN 1549-7747, E-ISSN 1558-3791, Vol. 65, no 11, p. 1634-1638Article in journal (Refereed) Published
    Abstract [en]

    An all-digital pulse width modulated (PWM) transmitter using outphasing is proposed. The transmitter uses PWM to encode the amplitude, and outphasing for enhanced phase control. In this way, the phase resolution of the transmitter is doubled. The proposed scheme was implemented using Stratix IV FGPA and class-D PAs fabricated in a 130 nm standard CMOS. From the measurement results, a spectral performance improvement is observed due to the enhanced phase resolution. As compared to an all-digital polar PWM transmitter, the error vector magnitude for proposed transmitter is reduced by 4.1% and the adjacent channel leakage ratio shows an improvement of 5.6 dB for a 1.4 MHz LTE up-link signal for a carrier frequency of 700 MHz at the saturated output power of 25 dBm.

    Place, publisher, year, edition, pages
    IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2018
    Keywords
    Switch-mode power amplifier; polar PWM; image distortion; aliasing distortion; FPGA
    National Category
    Telecommunications
    Identifiers
    urn:nbn:se:liu:diva-152816 (URN)10.1109/TCSII.2017.2766099 (DOI)000448935400029 ()
    Available from: 2018-11-22 Created: 2018-11-22 Last updated: 2019-01-07
    4. Power-efficient time-to-digital converter for all-digital frequency locked loops
    Open this publication in new window or tab >>Power-efficient time-to-digital converter for all-digital frequency locked loops
    2015 (English)In: 2015 EUROPEAN CONFERENCE ON CIRCUIT THEORY AND DESIGN (ECCTD), Institute of Electrical and Electronics Engineers (IEEE), 2015, p. 300-303Conference paper, Published paper (Refereed)
    Abstract [en]

    An 8-bit time-to-digital converter (TDC) for all-digital frequency-locked loops ispresented. The selected architecture uses a Vernier delay line where the commonlyused D flip-flops are replaced with a single enable transistor in the delay elements.This architecture allows for an area efficient and power efficient implementation. Thetarget application for the TDC is an all-digital frequency-locked loop which is alsooverviewed in the paper. A prototype chip has been implemented in a 65 nm CMOSprocess with an active core area of 75μmˆ120μm. The time resolution is 5.7 ps with apower consumption of 1.85 mW measured at 50 MHz sampling frequency.

    Place, publisher, year, edition, pages
    Institute of Electrical and Electronics Engineers (IEEE), 2015
    National Category
    Electrical Engineering, Electronic Engineering, Information Engineering
    Identifiers
    urn:nbn:se:liu:diva-112589 (URN)10.1109/ECCTD.2015.7300008 (DOI)000380498200010 ()978-1-4799-9877-7 (ISBN)
    Conference
    European Conference on Circuit Theory and Design (ECCTD)
    Available from: 2014-12-04 Created: 2014-12-04 Last updated: 2019-01-07Bibliographically approved
    5. A modified switching scheme for multiplexer based thermometer-to-binary encoders
    Open this publication in new window or tab >>A modified switching scheme for multiplexer based thermometer-to-binary encoders
    2014 (English)In: 32nd NORCHIP Conference, 27-28 October 2014, Tampere, Finland, IEEE , 2014, p. 1-4Conference paper, Oral presentation only (Refereed)
    Abstract [en]

    A modified switching scheme for thermometer-to-binary encoders used in time-to-digital converters (TDCs) is presented. The proposed scheme enables power savings up to 40% for a 256 bit encoder by taking advantage of the operating nature of the TDCs and by preventing unnecessary switchings to pass through the encoder tree. The efficiency of the proposed scheme is verified for thermometer encoders of different word lengths. It is observed that the power savings increase with the length of the thermometer encoder.

    Place, publisher, year, edition, pages
    IEEE, 2014
    National Category
    Electrical Engineering, Electronic Engineering, Information Engineering
    Identifiers
    urn:nbn:se:liu:diva-113278 (URN)10.1109/NORCHIP.2014.7004733 (DOI)978-1-4799-5442-1 (ISBN)
    Conference
    NORCHIP 2014. The Nordic Microelectronics event, 32nd Norchip Conference 27-28 October 2014, Tampere, Finland
    Available from: 2015-01-14 Created: 2015-01-14 Last updated: 2019-01-07Bibliographically approved
  • Fotouhi, Omid
    et al.
    German Cancer Consortium (DKTK) partner site Freiburg, German Cancer Research Center (DKFZ) and Department of Urology, Medical Center-University of Freiburg, Germany.
    Zedenius, Jan
    Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden; Department of Breast and Endocrine Surgery, Karolinska University Hospital, Stockholm, Sweden.
    Höög, Anders
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Diagnostics, Clinical pathology. Department of Oncology-Pathology, Karolinska Institutet, Stockholm, Sweden; Department of Pathology and Cytology, Karolinska University Hospital, Stockholm, Sweden.
    Juhlin, Carl Christofer
    Department of Oncology-Pathology, Karolinska Institutet, Stockholm, Sweden; Department of Pathology and Cytology, Karolinska University Hospital, Stockholm, Sweden.
    Regional differences in somatostatin receptor 2 (SSTR2) immunoreactivity is coupled to level of bowel invasion in small intestinal neuroendocrine tumors2018In: Neuro - endocrinology letters, ISSN 0172-780X, Vol. 39, no 4, p. 305-309Article in journal (Refereed)
    Abstract [en]

    OBJECTIVE: Somatostatin receptor (SSTR) expression constitutes a pivotal cornerstone for accurate radiological detection and medical treatment of small intestinal neuroendocrine tumors (SI-NETs), and the development of somatostatin analogues for these purposes have revolutionized the clinical work-up. Previous assessments of SSTR isoform expression in SI-NETs have found correlations to overall prognosis and treatment response, however these analyses usually report overall tumoral immunoreactivity, and little is reported regarding histo-regional differences in expressional patterns.

    METHODS: Thirty-seven primary SI-NETs (WHO grade I, n=32 and WHO grade II, n=5) were collected and assessed for SSTR2 immunohistochemistry. Samples were stratified with regards to histological level of bowel infiltration and spread (mucosal region, muscularis propria region, subserosal region) and each of these tumoral regions was separately scored by SSTR2 staining localization (membrane, cytoplasmic), overall staining intensity and local staining differences within each region.

    RESULTS: SSTR2 immunoreactivity was progressively weaker as the tumor cells advanced through the small intestinal layers. This was exemplified by a reduction in the amount of tumor samples with strong SSTR2 expression in the deeper histological levels of the section; 56% of tumors displayed strong SSTR2 expression in the mucosal region, as compared to 29% and 30% of tumors within muscularis propria and subserosal layers, respectively.

    CONCLUSIONS: This observation indicates a down-regulation of SSTR2 expression as the tumors progress through the intestinal wall, which might signify underlying biological processes of importance for SI-NET invasion behavior.

  • Abdelrahman, Islam
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Surgery, Orthopedics and Oncology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Anaesthetics, Operations and Specialty Surgery Center, Department of Hand and Plastic Surgery. Plastic Surgery Unit, Surgery Department, Suez Canal University, Ismailia, Egypt.
    Elmasry, Moustafa
    Linköping University, Department of Clinical and Experimental Medicine, Division of Surgery, Orthopedics and Oncology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Anaesthetics, Operations and Specialty Surgery Center, Department of Hand and Plastic Surgery. Plastic Surgery Unit, Surgery Department, Suez Canal University, Ismailia, Egypt.
    Steinvall, Ingrid
    Linköping University, Department of Clinical and Experimental Medicine, Division of Surgery, Orthopedics and Oncology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Anaesthetics, Operations and Specialty Surgery Center, Department of Hand and Plastic Surgery.
    Olofsson, Pia
    Linköping University, Department of Clinical and Experimental Medicine, Division of Surgery, Orthopedics and Oncology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Anaesthetics, Operations and Specialty Surgery Center, Department of Hand and Plastic Surgery.
    Nettelblad, Hans
    Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Anaesthetics, Operations and Specialty Surgery Center, Department of Hand and Plastic Surgery. Linköping University, Department of Clinical and Experimental Medicine, Division of Surgery, Orthopedics and Oncology.
    Zdolsek, Johann
    Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Anaesthetics, Operations and Specialty Surgery Center, Department of Hand and Plastic Surgery. Linköping University, Department of Clinical and Experimental Medicine, Division of Surgery, Orthopedics and Oncology.
    Versatility of the Extensor Digitorum Brevis Muscle Flap in Lower Limb Reconstruction2018In: Plastic and Reconstructive Surgery – Global Open, E-ISSN 2169-7574Article in journal (Refereed)
    Abstract [en]

    Background: Reconstruction of complex defects in the lower leg is a challenge. Although microvascular free tissue transfer is a popular technique, experience and available resources limit its use. Furthermore, free tissue transfer is not always required in the reconstruction of small lower leg defects, as many of them can be reconstructed with local alternatives such as an extensor digitorum brevis flap (EDB). Our aim was to describe our experience of the last 20 years with the EDB as a local muscle flap to cover small complex lower leg defects to establish its clinical feasibility and to document its associated complications. Methods: All adult patients who were operated with EDB flap reconstruction of the lower limb during 1997–2017 at the Department of Hand and Plastic Surgery, Linköping University Hospital, were included in this retrospective study. Results: Of 64 patients operated, only 7 had total flap failure, and the rate of complete success was 73% (47/64). Most of the skin defects were associated with fractures or complications thereof and were located in the ankle region, the dorsum of the foot, and the distal third of tibia or even the proximal tibia. Defects in the malleolar region and coexisting cardiovascular condition were factors associated with flap loss (either partial or total). Conclusion: The pedicled EDB-flap has, in our hands, proved to be a versatile and safe reconstructive option in the reconstruction of small defects in the lower leg and foot. Long-time follow-up is, however, recommended. 

  • Abtahi, Jahan
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Anaesthetics, Operations and Specialty Surgery Center, Maxillofacial Unit.
    Ajan, Aida
    Linköping University, Department of Clinical and Experimental Medicine, Division of Surgery, Orthopedics and Oncology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Anaesthetics, Operations and Specialty Surgery Center, Maxillofacial Unit.
    Malignant Transformation of Ossifying Fibroma into Parosteal Osteosarcoma with High-grade Component: Presentation of an Unusual Case and Review of the Literature2018In: The Open Dentistry Journal, E-ISSN 1874-2106, Vol. 12, p. 1059-1068Article in journal (Refereed)
    Abstract [en]

    Background: Parosteal Osteosarcoma of the Jaw (POSJ) is a rare entity that is associated with a high survival rate. Several case reports and case series of POSJ have been published in the literature, but few authors have described development of this tumor by possible transformation from a fibro-osseous neoplasm. Objective: We present a rare occurrence of parosteal osteosarcoma with involvement of the posterior maxilla, orbit floor, and infra-temporal fossa in a 20-year-old man. Furthermore, we performed a literature review regarding clinical, radiological, and histological features; treatment strategies; and etiology/pathophysiology. Methods: A PubMed search yielded a total of 74 articles and the articles were sorted according to their corresponding key area of focus. Results: This was a case of POSJ with high-grade component in the maxillofacial region of a 20-year old male. Co-expression of MDM2 and CDK4 was confirmed. At 2.5-year follow-up, the patient had died. The literature review revealed 18 articles including 20 cases of POSJ. Four cases represent the possible development of this tumor by transformation from a fibro-osseous neoplasm: Two cases of fibrous dysplasia, one case of cemento-ossifying fibroma, and the case of Ossifying Fibroma (OF) in the present study. Conclusion: In conclusion, we found an unusual case of POSJ of the midface in a patient with a previous diagnosis of OF in the same region. To our knowledge, there have been no previous reports of development of POSJ in OF. Furthermore, this is the first described case of high-grade surface osteosarcoma in the craniofacial region.

  • Public defence: 2019-01-25 09:15 Hugo Theorells sal, Linköping
    Drissi, Natasha Morales
    Linköping University, Department of Medical and Health Sciences, Division of Radiological Sciences. Linköping University, Faculty of Medicine and Health Sciences. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Brain Networks and Dynamics in Narcolepsy2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Narcolepsy is a chronic sleep disorder, characterised by excessive daytime sleepiness with frequent uncontrollable sleep attacks. In addition to sleeprelated problems, changes in cognition have also been observed in patients with narcolepsy and has been linked to the loss of Orexin-A in a number of studies. Results from previous functional and structural neuroimaging studies would suggest that the loss of Orexin-A has numerous downstream effects in terms of both resting state glucose metabolism and perfusion and reduction in cortical grey matter.

    Specifically, studies investigating narcolepsy with positron emission tomography (PET) and single photon emission computed tomography (SPECT) have observed aberrant perfusion and glucose metabolism in the hypothalamus and thalamus, as well as in prefrontal cortex. A very recent PET study in a large cohort of adolescents with type 1 narcolepsy further observed that the hypoand hypermetabolism in many of these cortico-frontal and subcortical brain regions also exhibited significant correlations with performance on a number of neurocognitive tests. These findings parallel those found in structural neuroimaging studies, where a reduction of cortical grey matter in frontotemporal areas has been observed.

    The Aim of this thesis was to investigate mechanisms and aetiology behind the symptoms in narcolepsy through the application of different neuroimaging techniques. I present in this thesis evidence supporting that the complaints about subjective memory deficits in narcolepsy are related to a misallocation of resources.

    I further describe how this has its seat in defective default mode network activation, possibly involving alterations to GABA and Glutamate signaling. In addition to this, I present our findings of a structural deviation in an area of the brainstem previously not described in the aetiology of narcolepsy.

    This finding may have implications for further understanding the aetiology of the disease and the specific neuronal populations involved.

    In addition to this, I show evidence from adipose tissue measurements in specific compartments, confirming that weight gain in narcolepsy is characterized by centrally located weight gain and may be specifically related to OX changes, but maybe not brown adipose tissue volume.

    The findings presented in this thesis provides new insights to the pathophysiology of narcolepsy beyond the well-known depletion of OX producing neurons in the hypothalamus.

    List of papers
    1. Altered Brain Microstate Dynamics in Adolescents with Narcolepsy
    Open this publication in new window or tab >>Altered Brain Microstate Dynamics in Adolescents with Narcolepsy
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    2016 (English)In: Frontiers in Human Neuroscience, ISSN 1662-5161, E-ISSN 1662-5161, Vol. 10, no 369Article in journal (Refereed) Published
    Abstract [en]

    Narcolepsy is a chronic sleep disorder caused by a loss of hypocretin-1 producing neurons in the hypothalamus. Previous neuroimaging studies have investigated brain function in narcolepsy during rest using positron emission tomography (PET) and single photon emission computed tomography (SPECT). In addition to hypothalamic and thalamic dysfunction they showed aberrant prefrontal perfusion and glucose metabolism in narcolepsy. Given these findings in brain structure and metabolism in narcolepsy, we anticipated that changes in functional magnetic resonance imaging (fMRI) resting state network (RSN) dynamics might also be apparent in patients with narcolepsy. The objective of this study was to investigate and describe brain microstate activity in adolescents with narcolepsy and correlate these to RSNs using simultaneous fMRI and electroencephalography (EEG). Sixteen adolescents (ages 13-20) with a confirmed diagnosis of narcolepsy were recruited and compared to age-matched healthy controls. Simultaneous EEG and fMRI data were collected during 10 min of wakeful rest. EEG data were analyzed for microstates, which are discrete epochs of stable global brain states obtained from topographical EEG analysis. Functional fMRI data were analyzed for RSNs. Data showed that narcolepsy patients were less likely than controls to spend time in a microstate which we found to be related to the default mode network and may suggest a disruption of this network that is disease specific. We concluded that adolescents with narcolepsy have altered resting state brain dynamics.

    Place, publisher, year, edition, pages
    FRONTIERS MEDIA SA, 2016
    Keywords
    narcolepsy; default mode network; functional magnetic resonance imaging (fMRI); electroencephalography (EEG); microstates; resting state networks; orexin; sleep
    National Category
    Neurology
    Identifiers
    urn:nbn:se:liu:diva-131167 (URN)10.3389/fnhum.2016.00369 (DOI)000380989900001 ()27536225 (PubMedID)
    Note

    Funding Agencies|Research Council of South East Sweden (FORSS); Knut and Alice Wallenberg foundation (KAW); strategic research area of systems neurobiology at Linkoping University; Country council of Ostergotland Sweden

    Available from: 2016-09-20 Created: 2016-09-12 Last updated: 2019-01-04
    2. Evidence for cognitive resource imbalance in adolescents with narcolepsy
    Open this publication in new window or tab >>Evidence for cognitive resource imbalance in adolescents with narcolepsy
    Show others...
    2018 (English)In: Brain Imaging and Behavior, ISSN 1931-7557, E-ISSN 1931-7565, Vol. 12, no 2, p. 411-424Article in journal (Refereed) Published
    Abstract [en]

    The study investigated brain activity changes during performance of a verbal working memory task in a population of adolescents with narcolepsy. Seventeen narcolepsy patients and twenty healthy controls performed a verbal working memory task during simultaneous fMRI and EEG acquisition. All subjects also underwent MRS to measure GABA and Glutamate concentrations in the medial prefrontal cortex. Activation levels in the default mode network and left middle frontal gyrus were examined to investigate whether narcolepsy is characterized by an imbalance in cognitive resources. Significantly increased deactivation within the default mode network during task performance was observed for the narcolepsy patients for both the encoding and recognition phases of the task. No evidence for task performance deficits or reduced activation within the left middle frontal gyrus was noted for the narcolepsy patients. Correlation analyses between the spectroscopy and fMRI data indicated that deactivation of the anterior aspect of the default mode in narcolepsy patients correlated more with increased concentrations of Glutamate and decreased concentrations of GABA. In contrast, deactivation in the default mode was correlated with increased concentrations of GABA and decreased concentrations of Glutamate in controls. The results suggested that narcolepsy is not characterized by a deficit in working memory but rather an imbalance of cognitive resources in favor of monitoring and maintaining attention over actual task performance. This points towards dysregulation within the sustained attention system being the origin behind self-reported cognitive difficulties in narcolepsy.

    Place, publisher, year, edition, pages
    Springer-Verlag New York, 2018
    Keywords
    EEG, GABA, MRS, Narcolepsy, Working memory, fMRI
    National Category
    Radiology, Nuclear Medicine and Medical Imaging
    Identifiers
    urn:nbn:se:liu:diva-145535 (URN)10.1007/s11682-017-9706-y (DOI)000429029000011 ()28321606 (PubMedID)2-s2.0-85015625386 (Scopus ID)
    Available from: 2018-03-05 Created: 2018-03-05 Last updated: 2019-01-04Bibliographically approved
    3. Unexpected Fat Distribution in Adolescents With Narcolepsy
    Open this publication in new window or tab >>Unexpected Fat Distribution in Adolescents With Narcolepsy
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    2018 (English)In: Frontiers in Endocrinology, ISSN 1664-2392, E-ISSN 1664-2392, Vol. 9, article id 728Article in journal (Refereed) Published
    Abstract [en]

    Narcolepsy type 1 is a chronic sleep disorder with significantly higher BMI reported in more than 50% of adolescent patients, putting them at a higher risk for metabolic syndrome in adulthood. Although well-documented, the body fat distribution and mechanisms behind weight gain in narcolepsy are still not fully understood but may be related to the loss of orexin associated with the disease. Orexin has been linked to the regulation of brown adipose tissue (BAT), a metabolically active fat involved in energy homeostasis. Previous studies have used BMI and waist circumference to characterize adipose tissue increases in narcolepsy but none have investigated its specific distribution. Here, we examine adipose tissue distribution in 19 adolescent patients with narcolepsy type 1 and compare them to 17 of their healthy peers using full body magnetic resonance imaging (MRI). In line with previous findings we saw that the narcolepsy patients had more overall fat than the healthy controls, but contrary to our expectations there were no group differences in supraclavicular BAT, suggesting that orexin may have no effect at all on BAT, at least under thermoneutral conditions. Also, in line with previous reports, we observed that patients had more total abdominal adipose tissue (TAAT), however, we found that they had a lower ratio between visceral adipose tissue (VAT) and TAAT indicating a relative increase of subcutaneous abdominal adipose tissue (ASAT). This relationship between VAT and ASAT has been associated with a lower risk for metabolic disease. We conclude that while weight gain in adolescents with narcolepsy matches that of central obesity, the lower VAT ratio may suggest a lower risk of developing metabolic disease.

    Place, publisher, year, edition, pages
    FRONTIERS MEDIA SA, 2018
    Keywords
    orexin; hypocretin; brown adipose tissue; visceral adipose tissue; subcutaneous adipose tissue; BMI; magnetic resonance imaging (MRI); obesity
    National Category
    Endocrinology and Diabetes
    Identifiers
    urn:nbn:se:liu:diva-153502 (URN)10.3389/fendo.2018.00728 (DOI)000452268600001 ()
    Note

    Funding Agencies|Research Council of South East Sweden [FORSS-480551]; Knut and Alice Wallenberg foundation [KAW 2013.0076]

    Available from: 2019-01-02 Created: 2019-01-02 Last updated: 2019-01-04
  • Public defence: 2019-02-01 09:00 Hugo Theorell salen, Linköping
    Holm, Anna
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Cardiology in Linköping.
    Acute coronary syndrome: bleeding, platelets and gender2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    BACKGROUND

    Bleeding complications increase mortality in patients with acute coronary syndrome (ACS). Potential gender difference in bleeding regarding prevalence, location, severity and prognostic impact is still controversial and not well investigated. In regard to this aspect the relevance of triple antithrombotic therapy (TAT) is questioned. There is an ongoing debate on the clinical implications of TAT and furthermore assumed that bleeding complications, except impact on outcome, also are associated with great influence on health economy.

    The main focus of this thesis was to further investigate the incidence and impact of bleeding complications in patients treated for ACS, with special reference to gender disparities, TAT and health economics. The thesis will highlight the importance of improved bleeding prevention strategies for both men and women.

    METHOD

    Paper I, II and III

    Observational studies from the SWEDEHEART register.

    In paper I we investigated patients hospitalised with myocardial infarction (MI) during 2006–2008. Outcomes were in-hospital bleedings, in-hospital mortality and one-year mortality in hospital survivors.

    In paper II, all patients with MI, in the County of Östergötland, Sweden during 2010 were included and followed for one year. The patients' medical records were evaluated, in relation to short and long-term bleeding complications, bleeding location, withdrawal of platelet inhibiting drugs and nonfatal MI and death.

    Paper III included all patients discharged with (TAT) in the County of Östergötland 2009-2015. Information about bleeds and ischemic complications during one-year follow-up were retrieved from the medical records. Estimation of the health care costs associated with bleeding episodes were added to the evaluation.

    Paper IV

    Patients with MI, scheduled for coronary angiography were recruited. All patients received clopidogrel and aspirin. A subgroup of patients received GP IIb/IIIa-inhibitor. Outcomes were platelet aggregation assessed at several time points, using a Multiplate impedance aggregometer, measurement of P-selectin in plasma, evaluation of high residual platelet reactivity (HRPR) and low residual platelet reactivity (LRPR) respectively and incidence of bleeding complications. A comparison between women and men was performed.

    RESULTS

    Paper I

    A total number of 50.399 patients were included, 36.6% women. In-hospital bleedings were more common in women (1.9% vs. 3.1%, p<0.001) even after multivariable adjustment (OR 1.17, 95%, CI 1.01–1.37). The increased risk for women was found in STEMI (OR 1.46, 95% CI 1.10–1.94) and in those who underwent PCI (OR 1.80, 95% CI 1.45–2.24).

    In contrast the risk was lower in medically treated women (OR 0.79, 95% CI 0.62–1.00). After adjustment, in-hospital bleeding was associated with higher risk of oneyear mortality in men (OR 1.35, 95% CI 1.04–1.74), whereas this was not the case in women (OR 0.97, 95% CI 0.72–1.31).

    Paper II

    In total 850 consecutive patients were included. The total incidence of bleeding events was 24.4% (81 women and 126 men, p=ns). The incidence of all in hospital bleeding events was 13.2%, with no gender difference. Women had significantly more minor nonsurgery related bleeding events than men (5% vs 2.2%, p=0.02). During follow-up, 13.5% had a bleeding, with more non-surgery related bleeding events among women, 14.7% vs 9.7% (p=0.03). The most common bleeding localisation was the gastrointestinal tract, more in women than men (12.1% vs 7.6%, p=0.03). Women also had more access site bleeding complications (4% vs 1.7%, p=0.04), while men had more surgery related bleeding complications (6.4% vs 0.9%, p≤0.001). Increased mortality was found only in men with non-surgery related bleeding events (p=0.008).

    Paper III

    Among 272 identified patients, 156 bleeds occurred post-discharge, of which 28.8% were of gastrointestinal origin. In total 54.4% had at least one bleed during or after the index event and 40.1% bled post-discharge of whom 28.7% experienced a TIMI major or minor bleeding. Women discontinued TAT prematurely more often than men (52.9 vs 36.1%, p=0.01) and bled more (48.6 vs. 37.1%, p=0.09). One-year mean health care costs were EUR 575 and EUR 5787 in non-bleeding and bleeding patients, respectively.

    Paper IV

    We recruited 125 patients (37 women and 88 men). We observed significantly more inhospital bleeding events in women as compared to men (18.9% vs 6.8%, p=0.04). There were no differences in platelet aggregation using three different agonists, reflecting treatment of GPIIb/IIIa inhibitors, clopidogrel and aspirin, at four different time-points nor were there any differences in p-selectin in plasma 3 days after admission.

    CONCLUSION

    There is a remarkably high bleeding incidence among patients treated with DAPT and even more so if treated with TAT. Female gender is an independent risk factor of inhospital bleeding after myocardial infarction, this higher bleeding risk in women appears to be restricted to invasively treated patients and STEMI patients. Even if women had higher short- and long-term mortality, there was no difference between the genders among those who bled. After multivariable adjustment the prognostic impact of bleeding complications was higher in men

    Women seem to experience more minor/minimal bleeding complications than men, predominantly GI bleeding events and access site bleeding events, with no apparent impact on outcome.

    In contrast men with non-surgery related bleeding complications had higher mortality. There is a lack of differences between the genders concerning platelet aggregation. Our results do not support gender disparities in platelet reactivity and excess dosing as a major explanation for increased bleeding risk in women. Improved bleeding prevention strategies are warranted for both men and women.

    List of papers
    1. Gender difference in prognostic impact of in-hospital bleeding after myocardial infarction - data from the SWEDEHEART registry.
    Open this publication in new window or tab >>Gender difference in prognostic impact of in-hospital bleeding after myocardial infarction - data from the SWEDEHEART registry.
    2016 (English)In: European heart journal. Acute cardiovascular care, ISSN 2048-8734, Vol. 6, p. 463-472Article in journal (Refereed) Published
    Abstract [en]

    BACKGROUND: Bleeding complications increase mortality in myocardial infarction patients. Potential gender difference in bleeding regarding prevalence and prognostic impact is still controversial.

    OBJECTIVES: Gender comparison regarding incidence and prognostic impact of bleeding in patients hospitalised with myocardial infarction during 2006-2008.

    METHODS: Observational study from the SWEDEHEART register. Outcomes were in-hospital bleedings, in-hospital mortality and one-year mortality in hospital survivors.

    RESULTS: A total number of 50,399 myocardial infarction patients were included, 36.6% women. In-hospital bleedings were more common in women (1.9% vs. 3.1%, p<0.001) even after multivariable adjustment (odds ratio (OR) 1.17, 95% confidence interval (CI) 1.01-1.37). The increased risk for women was found in ST-elevation myocardial infarction (OR 1.46, 95% CI 1.10-1.94) and in those who underwent percutaneous coronary intervention (OR 1.80, 95% CI 1.45-2.24). In contrast the risk was lower in medically treated women (OR 0.79, 95% CI 0.62-1.00). After adjustment, in-hospital bleeding was associated with higher risk of one-year mortality in men (OR 1.35, 95% CI 1.04-1.74), whereas this was not the case in women (OR 0.97, 95% CI 0.72-1.31).

    CONCLUSIONS: Female gender is an independent risk factor of in-hospital bleeding after myocardial infarction. A higher bleeding risk in women appeared to be restricted to invasively treated patients and ST-elevation myocardial infarction patients. Even though women have higher short- and long-term mortality, there was no difference between the genders among bleeders. After multivariable adjustment the prognostic impact of bleeding complications was higher in men.

    Place, publisher, year, edition, pages
    Sage Publications, 2016
    Keywords
    Myocardial infarction; bleeding; gender; prognosis
    National Category
    Cardiac and Cardiovascular Systems
    Identifiers
    urn:nbn:se:liu:diva-124287 (URN)10.1177/2048872615610884 (DOI)000385817800008 ()26450782 (PubMedID)
    Available from: 2016-01-25 Created: 2016-01-25 Last updated: 2019-01-10
    2. Bleeding complications after myocardial infarction in a real world population - An observational retrospective study with a sex perspective
    Open this publication in new window or tab >>Bleeding complications after myocardial infarction in a real world population - An observational retrospective study with a sex perspective
    Show others...
    2018 (English)In: Thrombosis Research, ISSN 0049-3848, E-ISSN 1879-2472, Vol. 167, p. 156-163Article in journal (Refereed) Published
    Abstract [en]

    Introduction: The aim of the current study was to assess bleeding events, including severity, localisation and prognostic impact, in a real world population of men and women with myocardial infarction (MI). Methods and results: In total 850 consecutive patients were included during 2010 and followed for one year. Bleeding complications were identified by searching of each patients medical records and characterised according to the TIMI criteria. For this analysis, only the first event was calculated. The total incidence of bleeding events was 24.4% (81 women and 126 men, p=ns). The incidence of all inhospital bleeding events was 13.2%, with no sex difference. Women had significantly more minor non-surgery related bleeding events than men (5% vs 2.2%, p=0.02). During follow-up, 13.5% had a bleeding, with more non-surgery related bleeding events among women, 14.7% vs 9.7% (p=0.03). The most common bleeding localisation was the gastrointestinal tract, more in women than men (12.1% vs 7.6%, p=0.03). Women had also more access site bleeding complications (4% vs 1.7%, p=0.04), while men had more surgery related bleeding complications (6.4% vs 0.9%, p=0.001). Increased mortality was found only in men with non-surgery related bleeding events (p=0.008). Conclusions: Almost one in four patients experienced a bleeding complication through 12 months follow-up after a myocardial infarction. Women experienced more non-surgery related minor/minimal bleeding complications than men, predominantly GI bleeding events and access site bleeding events, with no apparent impact on outcome. In contrast men with non-surgery related bleeding complications had higher mortality. Improved bleeding prevention strategies are warranted for both men and women.

    Place, publisher, year, edition, pages
    PERGAMON-ELSEVIER SCIENCE LTD, 2018
    Keywords
    Myocardial infarction; Bleeding; Sex; Mortality
    National Category
    Cardiac and Cardiovascular Systems
    Identifiers
    urn:nbn:se:liu:diva-149865 (URN)10.1016/j.thromres.2018.05.023 (DOI)000437845800027 ()29857272 (PubMedID)
    Note

    Funding Agencies|Ostergotland County Council [LIO610841]

    Available from: 2018-08-02 Created: 2018-08-02 Last updated: 2019-01-04
  • Public defence: 2019-01-31 09:00 Almen, Ingång 64, Linköping
    Johnson, Christina
    Linköping University, Department of Medical and Health Sciences, Division of Nursing Science. Linköping University, Faculty of Medicine and Health Sciences.
    Telephone advice nursing: communication, patient satisfaction and tool development2018Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Background: Telenursing has rapidly expanded in many countries. In Sweden, a national telephone advisory nursing service reaches the entire nation and receives approximately 4,5 million calls per year. The six phase nursing process – assessment, nursing diagnosis, setting goals, planning, implementation and evaluation – can be used when managing a caller’s health problem. In telenursing, a person-centred approach makes for more satisfied and appreciative callers. The core component of interaction is the verbal communication between the telenurse and caller. Several studies have revealed the need for the development of communication competence in telenursing. Structured analyses of conversations between telenurses and callers is one way to increase telenurses’ awareness of their communication and interpersonal competence. This type of analysis requires a valid formative self-assessment tool. To evaluate communicative effectiveness, the patient perspective of the interpersonal aspects of interaction are described as a necessary component, and satisfaction surveys designed for a telenursing context are recommended. Therefore, a questionnaire is needed that evaluates the effects of telenurse communication training from the caller’s perspective.

    Aims: The overall aim of these two studies was to develop tools to enable improvements and evaluations in communication and interpersonal competence in telenursing from the perspective of both the telenurse and the caller.

    Study 1: To develop a self-assessment tool aiming to raise telenurses’ awareness of their communication and interpersonal competence and highlight areas in need of improvement.

    Study 2: To develop and assess content validity of a theoretically anchored questionnaire that explores caller satisfaction in TAN as a result of the interaction between the caller and the telenurse.

    Methods:

    Study 1: The development and the evaluation of content validity of the Telenursing Self-Assessment Tool (TSAT) started with a literature search and domain identification, which were used to generate the items. The assessment of the content validity was performed in two steps. First, an expert group completed two rounds of assessments using Content Validity Index (CVI). Second, telenurses tested the tool and assessed the content validity using CVI. Thereafter, the telenurses participated in consensus discussions. Refinements of the tool were done after every assessment.

    Study 2: The development and the evaluation of content validity of the Telenursing Interaction and Satisfaction Questionnaire (TISQ) started with a literature search and domain identification, which were used to generate the items. The assessment of the content validity was performed in two steps. First, cognitive interviews were performed with the callers, the target population. Next, experts evaluated the content validity using CVI. Refinements of the tool were done after every assessment. The Interaction Model of Client Health Behavior (IMCHB) provided theoretical guidance and support.

    Results:

    Study 1: The TSAT with 58 items was developed. The items were structured according to the nursing process and the tool was judged as having good content validity.

    Study 2: The TISQ consisting of 60 items based on the IMCHB was developed. The questionnaire was found to exhibit good content validity.

    Conclusions: This thesis describes the development and assessment of content validity of two theoretically anchored tools aimed to improve and evaluate communication and interpersonal competence in telenursing from the perspective of both the telenurse and the caller. The TSAT is meant to create learning opportunities, to provide self-direction, feedback, and coaching, and to guide the telenurse through the nursing process using a person-centred approach. The TISQ aims to explore the callers’ satisfaction and the callers’ perceptions of the interaction with the telenurse. With better knowledge about this, communication improvement and education in telenursing can be tailored to enhance caller satisfaction.

    List of papers
    1. Improvement of communication and interpersonal competence in telenursing - development of a self-assessment tool
    Open this publication in new window or tab >>Improvement of communication and interpersonal competence in telenursing - development of a self-assessment tool
    2015 (English)In: Journal of Clinical Nursing, ISSN 0962-1067, E-ISSN 1365-2702, Vol. 24, no 11-12, p. 1489-1501Article in journal (Refereed) Published
    Abstract [en]

    Aims and objectivesThe aim of this study was to develop a self-assessment tool aiming to raise telenurses awareness of their communication and interpersonal competence, and highlight areas in need of improvement. BackgroundSeveral studies have revealed the need for development of communication competence in telenursing. Structured analyses of conversations with patients/callers, is one way to increase telenurses awareness of their unique communication and interpersonal competence. DesignInstrument development, Validation assessment using the method Content Validity Index. MethodThe process to determine content validity was done in two stages; the development stage and the assessment stage. The development stage started with a literature search. The assessment stage was separated into two phases, assessment by an expert group and assessment and test by telenurses. The telenurses also participated in consensus discussions. ResultsA telenursing self-assessment tool with 58 items was developed. The items were sorted into five sections according to the nursing process. ConclusionThis study describes the thorough development process of the telenursing self-assessment tool to be used by telenurses in order to become aware of their unique communication and interpersonal competence when analysing their own conversations with patients/callers. As a formative tool it is meant to provide self-direction, feedback and coaching, and create learning opportunities. Relevance to clinical practiceThe self-assessment tool helps the telenurse to follow the nursing process, to be patient-centred, and it is meant to provide self-direction, feedback, and coaching, as well as create learning opportunities. The tool can contribute to the development of communication and interpersonal competence in telephone advice nursing. Further development of the tool may provide an objective scoring instrument for evaluating communication training and education in the field.

    Place, publisher, year, edition, pages
    Wiley: 12 months, 2015
    Keywords
    clinical competence; communication; hotlines; instrument development; nurse-patient relations; self-assessment; telenursing; triage
    National Category
    Communication Studies
    Identifiers
    urn:nbn:se:liu:diva-119577 (URN)10.1111/jocn.12705 (DOI)000355331300006 ()25393698 (PubMedID)
    Note

    Funding Agencies|National Medical Advisory Service Ltd (in Swedish Sjukvardsradgivningen SVR AB); County Council of Ostergotland, Sweden

    Available from: 2015-06-23 Created: 2015-06-22 Last updated: 2019-01-04
  • Public defence: 2019-01-25 09:19 ACAS, A-huset, Linköping
    Palmert, Frans
    Linköping University, Department of Management and Engineering, Engineering Materials. Linköping University, Faculty of Science & Engineering.
    Crack growth in single crystal nickel base superalloys under isothermal and thermomechanical fatigue2019Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    This work concerns the fatigue crack growth behaviour of nickel base single crystal superalloys. The main industrial application of this class of materials is in gas turbine blades, where the ability to withstand severe mechanical loading in combination with high temperatures is required. In order to ensure the structural integrity of gas turbine blades, knowledge of the fatigue crack growth behaviour under service-like conditions is of utmost importance. The aim of the present work is both to improve the understanding of the crack growth behaviour of single crystal superalloys and also to improve the testing and evaluation methodology for crack propagation under thermomechanical fatigue loading conditions. Single crystal superalloys have anisotropic mechanical properties and are prone to localization of inelastic deformation along the close-packed planes of the crystal lattice. Under some conditions, crystallographic crack growth occurs along these planes and this is a complicating factor throughout the whole chain of crack propagation life simulation; from material data generation to component calculation. Fatigue crack growth testing has been performed, both using conventional isothermal testing methods and also using thermomechanical fatigue crack growth testing. Experimental observations regarding crystallographic crack growth have been made and its dependence on crystal orientation and testing temperature has been investigated. Quantitative crack growth data are however only presented for the case of Mode I crack growth under isothermal as well as thermomechanical fatigue conditions. Microstructural investigations have been undertaken to investigate the deformation mechanisms governing the crack growth behaviour. A compliance based method for the evaluation of crack opening force under thermomechanical fatigue conditions was developed, in order to enable a detailed analysis of the test data. The crack opening force evaluation proved to be of key importance in the understanding of the crack driving force under different testing conditions.

    List of papers
    1. Fatigue crack growth behaviour of an alternative single crystal nickel base superalloy
    Open this publication in new window or tab >>Fatigue crack growth behaviour of an alternative single crystal nickel base superalloy
    2018 (English)In: International Journal of Fatigue, ISSN 0142-1123, E-ISSN 1879-3452, Vol. 109, p. 166-181Article in journal (Refereed) Published
    Abstract [en]

    The fatigue crack growth behaviour of a single crystal nickel base superalloy was studied at three different temperatures (20 degrees C, 500 degrees C and 750 degrees C) and three different crystallographic orientations. At the highest testing temperature, the influence of hold time at maximum load was also evaluated. Under some of the testing conditions, crystallographic crack growth occurred along {1 1 1} planes, which were non-perpendicular to the loading direction. The propensity for crystallographic cracking was observed to be strongly temperature dependent with a maximum occurring at the intermediate testing temperature of 500 degrees C. During non-crystallographic, Mode I crack growth the crack tended to avoid the gamma particles and propagated preferentially through the gamma matrix.

    Place, publisher, year, edition, pages
    ELSEVIER SCI LTD, 2018
    Keywords
    Single crystal superalloy; Fatigue; Crack growth; Crystallographic crack growth; Temperature dependence; Orientation dependence; Hold time influence
    National Category
    Applied Mechanics
    Identifiers
    urn:nbn:se:liu:diva-145431 (URN)10.1016/j.ijfatigue.2017.12.003 (DOI)000425073100017 ()
    Note

    Funding Agencies|Siemens Industrial Turbomachinery AB in Finspang, Sweden; Swedish Energy Agency, via the Research Consortium of Materials Technology for Thermal Energy Processes [KME-702]

    Available from: 2018-04-03 Created: 2018-04-03 Last updated: 2019-01-04
  • Public defence: 2019-01-18 10:15 Planck, Fysikhouset, Linköping
    Xia, Yuxin
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Polymer/polymer blends in organic photovoltaic and photodiode devices2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Organic photovoltaics devices (OPV) have attracted attentions of scientist for their potential as inexpensive, lightweight, flexible and suitable for roll-to-roll production. In recent years, considerable attention has been focused on new acceptor materials, either polymeric or small molecules, to replace the once dominating fullerene derivatives. The emergence of numerous new non-fullerene materials has driven power conversion efficiency (PCE) up to 17%, attracting more and more interests of commercialization.

    Polymer acceptors with more morphology stability, more absorption and more desired energy levels has been intensively studied and show great potential for large area and low-cost production in the future. OPV at this moment is not yet competitive with inorganic solar cells in PCE but is more attractive in flexibility, low weight and semitransparency. In this thesis, some basic knowledges of OPV is introduced in the first few chapters, while the next chapters are focusing on polymer-polymer blends and investigating novel structures and techniques for large scale production of solar cells and photodetectors aiming at maximizing these advantages to compete with inorganic counterpart.

    Thermal annealing effects on polymer-polymer solar cells based is studied. Annealed devices show doubled power conversion efficiency compared to non-annealed devices. Based on the morphology—mobility examination, we conclude that the better charge transport is achieved by higher order and better interconnected networks of the bulk heterojunction in the annealed active layers. The annealing improves charge transport and extends the conjugation length of the polymers, which do help charge generation and meanwhile reduce recombination. The blend of an amorphous polymer and a semi-crystalline polymer can thus be modified by thermal annealing to double the power conversion efficiency.

    A novel concept of all-polymer organic photovoltaics device is demonstrated in this thesis where all the layers are made out of polymers. We use PEDOT:PSS as semitransparent anode and polyethyleneimine modified PEDOT:PSS as semitransparent cathode, both of which are slot-die printed on polyethylene terephthalate(PET). Active layers are deposited on cathode and anode surfaces by spin coating separately. These layers are then joined through a roll-to-roll compatible lamination process. This forms a semitransparent and flexible solar cell. By laminating a thin layer acceptor polymer to a thick polymer-polymer blend, we can further improve the performance by reducing traps comparing to laminating blend to blend.

    Flexible and semitransparent all-polymer photodiodes with different geometries can be fabricated through lamination. By choosing high band gap polymers and appropriate combination of two or more polymers, organic photodiode with low noise and high specific detectivity can be obtained. Comparison between bilayer and bulk heterojunction devices gives better understanding of the origin of noise and provides ways to improve the performance of photodiodes as detector.

    Noise level is a critical parameter for photodetectors. The difficulties of measuring the noise of photodetectors make some researchers prefer the estimated shot noise as the dominating one and ignore the thermal noise and 1/f noise. The latter two terms are sometimes several orders higher than the former, noting the importance of experimentally measuring noise.

    The use of semi-transparent photovoltaic devices causes an inevitable loss of photocurrent, as light transmitted has not been absorbed. This trivial effect also leads to a loss of photovoltage, an effect partially due to the lower photocurrent but also due to the geometry of the semitransparent photovoltaic device. We here demonstrate and evaluate this photovoltage loss in semi-transparent organic photovoltaic devices, compared with non-transparent solar cells of the same material. Semi-transparent solar cells in addition introduce photovoltage loss when formed by lamination. We document and analyze these effects for a number of polymer blends in the form of bulk heterojunctions.

    List of papers
    1. Inverted all-polymer solar cells based on a quinoxaline-thiophene/naphthalene-diimide polymer blend improved by annealing
    Open this publication in new window or tab >>Inverted all-polymer solar cells based on a quinoxaline-thiophene/naphthalene-diimide polymer blend improved by annealing
    Show others...
    2016 (English)In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 4, no 10, p. 3835-3843Article in journal (Refereed) Published
    Abstract [en]

    We have investigated the effect of thermal annealing on the photovoltaic parameters of all-polymer solar cells based on a quinoxaline-thiophene donor polymer (TQ1) and a naphthalene diimide acceptor polymer (N2200). The annealed devices show a doubled power conversion efficiency compared to nonannealed devices, due to the higher short-circuit current (J(sc)) and fill factor (FF), but with a lower open circuit voltage (V-oc). On the basis of the morphology-mobility examination by several scanning force microscopy techniques, and by grazing-incidence wide-angle X-ray scattering, we conclude that better charge transport is achieved by higher order and better interconnected networks of the bulk heterojunction in the annealed active layers. The annealing improves charge transport and extends the conjugation length of the polymers, which do help in charge generation and meanwhile reduce recombination. Photoluminescence, electroluminescence, and light intensity dependence measurements reveal how this morphological change affects charge generation and recombination. As a result, the J(sc) and FF are significantly improved. However, the smaller band gap and the higher HOMO level of TQ1 upon annealing causes a lower V-oc. The blend of an amorphous polymer TQ1, and a semi-crystalline polymer N2200, can thus be modified by thermal annealing to double the power conversion efficiency.

    Place, publisher, year, edition, pages
    ROYAL SOC CHEMISTRY, 2016
    National Category
    Biological Sciences
    Identifiers
    urn:nbn:se:liu:diva-127066 (URN)10.1039/c6ta00531d (DOI)000371967000030 ()
    Note

    Funding Agencies|Swedish Energy Agency; Swedish Research council, NSFC [21504006, 21534003]; Knut and Alice Wallenberg Foundation through a Wallenberg scholar grant; China Scholarship Council (CSC); graduate student short-term abroad research project of Jinan University; program for the Excellent Doctoral Dissertations of Guangdong Province [ybzzxm201114]; U.S. Department of Energy [DE-AC02-05CH11231]

    Available from: 2016-04-13 Created: 2016-04-13 Last updated: 2019-01-04
    2. Semitransparent all-polymer solar cells through lamination
    Open this publication in new window or tab >>Semitransparent all-polymer solar cells through lamination
    2018 (English)In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 6, no 42, p. 21186-21192Article in journal (Refereed) Published
    Abstract [en]

    In this work, we demonstrate all-polymer solar cells where all the layers are made from polymers. We use PEDOT:PSS as the semitransparent anode and polyethyleneimine modified PEDOT:PSS as the semitransparent cathode, both of which are slot-die printed on polyethylene terephthalate (PET). Active layers are deposited on the cathode and anode surfaces by spin coating separately. These layers are then joined through a roll-to-roll compatible lamination process. This results in a semitransparent and flexible solar cell. We have used two polymer-polymer systems and several combinations, and the highest power conversion efficiency (PCE) obtained is 2.3% with a mean transparency amp;gt;35% within the visible light range. By laminating a thin layer acceptor polymer to a thick polymer-polymer blend, we can improve the performance by reducing recombination, compared to laminating blend to blend, which is verified by the trap-limited charge transport, CELIV and electroluminescence.

    Place, publisher, year, edition, pages
    ROYAL SOC CHEMISTRY, 2018
    National Category
    Polymer Chemistry
    Identifiers
    urn:nbn:se:liu:diva-153535 (URN)10.1039/c8ta07992g (DOI)000451600200066 ()
    Note

    Funding Agencies|Swedish Energy Agency; Knut and Alice Wallenberg foundation (KAW); China Scholarship Council (CSC)

    Available from: 2018-12-20 Created: 2018-12-20 Last updated: 2019-01-04
    3. Large-Area, Semitransparent, and Flexible All-Polymer Photodetectors
    Open this publication in new window or tab >>Large-Area, Semitransparent, and Flexible All-Polymer Photodetectors
    Show others...
    2018 (English)In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 28, no 48, article id 1805570Article in journal (Refereed) Published
    Abstract [en]

    Photodetectors, converting optical signals from specific wavelengths to electrical signals, have many applications on photoimaging, optical communication, and environmental monitoring. Solution-processed organic photodetectors (OPDs) based on organic materials emerge promise especially for wearable electronics and smart buildings. In this work, new all-polymer photodetectors (all-PPDs) are developed based on bulk-heterojunction active layers which incorporate a donor polymer and an acceptor polymer. The inverted all-PPDs exhibit outstanding external quantum efficiency over 70%, low dark current density (J(d)) of 1.1 x 10(-8) A cm(-2), and high detectivity (D*) over 3.0 x 10(12) Jones with planar response over the entire visible range. It is one of the best-performing all-PPDs reported so far and is also comparable with many organic and inorganic photodetectors. By using lamination technique, large-area, semitransparent, flexible, and "fully" polymeric photodetectors are successfully fabricated for the first time, with D* over 10(11) Jones for double-side light detection. The results highlight the great potential for producing high-performance all-PPDs by taking advantages of various device architecture and solution-processing techniques.

    Place, publisher, year, edition, pages
    WILEY-V C H VERLAG GMBH, 2018
    Keywords
    all-polymer photodetectors; conjugated polymers; flexible electronics; semitransparent electronics
    National Category
    Materials Chemistry
    Identifiers
    urn:nbn:se:liu:diva-153367 (URN)10.1002/adfm.201805570 (DOI)000451118800014 ()
    Note

    Funding Agencies|Knut and Alice Wallenberg foundation through a Wallenberg Scholar grant; Ocean University of China; Ministry of Science and Technology [2016YFA0200700]; National Natural Science Foundation of China [21704082, 21875182, 21534003, 51320105014]; China Postdoctoral Science Foundation [2017M623162]; Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy [DE-AC02-05CH11231]; China Scholarship Council (CSC)

    Available from: 2018-12-18 Created: 2018-12-18 Last updated: 2019-01-04
  • Tsagalidis, Helena
    Linköping University, Department of Behavioural Sciences and Learning, Education and Adult Learning. Linköping University, Faculty of Educational Sciences.
    Tävlingsdomarnas bäst praxis-bedömning av yrkeskunnande i en yrkestävling [Competition judges' best-practice assessment of vocational knowledge and skills in a skills competition]2018In: Nordic Journal of Vocational Education and Training, ISSN 2242-458X, E-ISSN 2242-458X, Vol. 8, no 2, p. 93-120Article in journal (Refereed)
    Abstract [en]

    This article presents the results of a study of a youth cooking contest for upper secondary schools in Sweden, which was part of the Swedish Skills Competition. The material consists of observations, in the form of shadowing, of the competition judges during the competition, and conversations with judges before and during the competition. The text has a vocational knowledge and skills perspective and relates to answering the question: what vocational knowledge and skills are valued as significant by the competition judges in the school competition? The analyses employ the concepts of key qualifications, specific vocational knowledge and skills, and forms of knowledge, that together contribute to understanding how vocational knowledge and skills can be described and valued. This article focuses on the competition judges' best-practice assessments of five contest teams' performance, from preparation of menu to tasting of it and their work afterwards. It also demonstrates that professionalism (skilful performance) and judicious action are the most important aspects of what the competition judgments focused on in this competition.

  • Andersson, Rasmus
    et al.
    Linköping University, Department of Management and Engineering, Machine Design.
    Engström, Fredrik
    Linköping University, Department of Management and Engineering, Machine Design.
    Compact lifting mechanism of autonomous vehicle: Concept development and guidelines for implementation2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The material handling industry is facing new challenges with the divergence from the established EUR-pallet. In correlation with the autonomous technology which is becoming more advanced, available and affordable than ever before, new demands are created. The industry calls for innovative material handling automated guided vehicles to meet the requirements. These vehicles will increase the owners profit by being more efficient in terms of time, size and cost. The aim for this study is to develop suitable lifting mechanisms for an ultra-compact automated guided vehicle. A generic product development process is utilized. The requirements for the lifting mechanism is defined and presented in a specification. A selection of employees are involved in the ideation and concept generation to add in-house knowledge and experience. The concepts are developed with component research, 3D visualizations and concept descriptions. The concepts are evaluated and the most promising are selected. The selected concepts are further developed with CAD-models, calculations and a selection of components. The concepts are compared with each other and the initial specification to assess the most suitable lifting mechanism. The single acting hydraulic system, including a Micro Power Pack and four small hydraulic cylinders, is considered the best suitable choice for an ultracompact material handling automated guided vehicle.

  • Pastuhov, Annika
    Vuxenpedagogik, Fakulteten för pedagogik och välfärdsstudier, Åbo Akademi, Turku, Finland.
    Att vara och agera medborgare: En etnografisk studie i folkbildande praktiker2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis is directed towards examining the relation between the ideals of Nordic popular education, such as freedom and equality, and the expressions of these ideals in the popular education practices. This was explored by conducting a study that assumed the perspective of the participant (i.e. the party for which popular education is making knowledge and education accessible). More specifically, the interest of this thesis is aimed towards the relationship between citizenship education as an ideal and the expressions of citizenship education in study circle practices.

    The purpose of this thesis is to contribute ethnographic knowledge about what expressions of citizenship can be identified within institutionalised popular education practices. The thesis draws upon a definition of study circles as arenas where the participants exchange experiences and explore knowledge concurrently with others in order to understand and change their living conditions. Citizenship in popular education practices is understood to consist of identification (i.e. being) and deeds (i.e. acting). Citizenship in this context takes place in social interactions where differences are encountered and private issues are translated into public concerns. In order to capture citizenship in its complexity and contextuality, an overarching research question was formulated for the present study: What expressions does citizenship take in study circle practices? This research question was specified through the following three questions: (1) How are the participants being citizens in study circle practices? (2) How are the participants acting as citizens in study circle practices? (3) How are private perspectives transcended in favour of common concerns in the study circle practices?

    This ethnographic study was conducted examining three different popular education practices: a senior carpenter circle (13 participants), a philosophy study circle (9 participants) and an English study circle (12 participants). The data mainly consist of field notes, written during and after the fieldwork, and audio recordings of the meetings. The ambition was to illuminate popular education practices as observed first-hand from a citizenship perspective. The three mentioned practices were chosen to complement each other and to shed light on the different sides of the multitude of institutionalised study circle practices. The overarching aim of the analysis was both to explore what was said and done in each study group and to portray these data in a manner that at once accurately derives from the activities in the group and is still understandable to an outsider.

    The citizenship of popular education is expressed in different ways depending on how the study groups perceive their shared identity and what the participants strive to accomplish together. In all three groups, the participants orient themselves and the practices of their groups towards their studies and thereby agree on what the group is supposed to be doing and how the socialising should take place. Through social interaction and cooperation, the participants gain new knowledge and deepen interests already chosen before entering the study circles. In all three cases, this was made possible because the groups consisted to a high degree of likeminded participants. The findings of the three studies are summarised and categorised through the notions of identity, involvement (delaktighet) and view on education (bildningssyn). This is developed into a discussion of different kinds of freedom within the citizenship of popular education in light of the three field studies—freedom from, freedom to and a temporary lack of freedom.

    In the three field studies, the citizenship of popular education is expressed as counterweights and second chances in relation to the everyday lives of the participants at large. The study circles provide opportunities to be and act as citizens in alternative ways than everyday life makes possible. At the same time, participation in the study circles reinforce already existing perceptions the participants have of themselves. Participation also contributes to the deepening of interests already chosen before the participants sought out the study circles.

    List of papers
    1. Att snickra medborgarskap?
    Open this publication in new window or tab >>Att snickra medborgarskap?
    2015 (Swedish)In: Nordisk kulturpolitisk tidskrift, ISSN 1403-3216, E-ISSN 2000-8325, Vol. 18, no 2, p. 219-232Article in journal (Refereed) Published
    Abstract [sv]

    Syftet för artikeln är att studera snickrandets medborgarskap som det tar sig uttryck i det sociala umgänget på en snickarkurs för seniorer inom institutionaliserad folkbildning i Finland (kallat «kansalaisopisto» på finska, «medborgarinstitut» på svenska). Folkbildning anses bidra till en fungerande demokrati genom sina kollektiva och deltagarorienterade verksamhetsformer och sitt innehåll. Målet med artikeln är att bidra med kunskap om hur detta ideal förverkligas och hur deltagandet i verksamhet inom den institutionaliserade folkbildningen kan förstås som uttrycksformer för medborgarskap. Studien har utförts som en etnografisk fältstudie med forskaren som en av deltagarna på kursen. Kursen pågick under 15 veckor, tre gånger i veckan. Gruppen består av tolv män och en kvinna i åldrarna mellan 60 och 80 år. Forskaren har strävat efter att bli en del av gruppen på dess villkor och att analysera och tolka verksamheten utgående från dess egna utgångspunkter. Snickrandet bland seniorerna i denna studie organiseras som en arbetsgemenskap. I denna gemenskap kan man agera som medborgare utgående från en gemensam värdegrund. Dessa värderingar tar sig uttryck som en strävan mot att uppfylla ett skötsamhetsideal för att kunna upprätthålla en handlingsberedskap som produktiv medborgare.

    Abstract [en]

    The purpose of this article is to study how the social interactions exhibited at a woodworking course for seniors within institutionalized popular education in Finland («kansalaisopisto» in Finnish, «medborgarinstitut» in Swedish) contribute to the participants' conceptualization of their citizenship. Popular education is considered to contribute to a functioning democracy through its collective and participant-centered activities and content. The aim of the article is to shed some light on how this ideal is realized and contribute knowledge about how participation in institutionalized popular education can be understood as an expression of citizenship. The study was conducted as an ethnographic field study with the researcher as a participant in the course. The course was held three times a week for 15 weeks. The participants consisted of 12 men and a woman between the ages of 60 and 80. The researcher aspired to become a part of the group in order to clarify what goes on in the course through thick descriptions relying on neither going native nor mimicking them. The seniors organize their woodworking in the course as a work community. Within this community, it is possible to act as a citizen in relation to shared basic values. These values are an aspiration to live up to ideals of conscientiousness and diligence in order to remain ready to act as a productive citizen.

    Place, publisher, year, edition, pages
    Högskolan i Borås, 2015
    Keywords
    democracy, citizenship, popular education, handicrafts, woodwork, ethnography, demokrati, medborgarskap, folkbildning, hantverk, snickeri, etnografi
    National Category
    Pedagogy
    Identifiers
    urn:nbn:se:liu:diva-143179 (URN)
    Available from: 2017-11-21 Created: 2017-11-21 Last updated: 2019-01-02Bibliographically approved
    2. Medborgarskap mellan närhet och distans: en etnografisk studie i en studiecirkel i filosofi
    Open this publication in new window or tab >>Medborgarskap mellan närhet och distans: en etnografisk studie i en studiecirkel i filosofi
    2017 (Swedish)In: Nordic Studies in Education, ISSN 1891-5914, E-ISSN 1891-5949, Vol. 37, no 2, p. 116-129Article in journal (Refereed) Published
    Abstract [en]

    The purpose of this article is to contribute to the understanding of enactments of citizenship through participation in a study circle in philosophy. Citizenship is viewed as comprising acting and being in-and-through the study circle. This links citizenship to social contexts, actions and education. The study was conducted as an ethnographic field study over eight months. In total nine people, men and women of different ages, gathered once a month. The participants shared an ambition to form an open group for all interested in philosophy. Here, the ideals of freedom and voluntary participation led to both inclusion and exclusion.

    Place, publisher, year, edition, pages
    Universitetsforlaget, 2017
    Keywords
    popular education, liberal adult education, study circle, citizenship, ethnography
    National Category
    Pedagogy
    Identifiers
    urn:nbn:se:liu:diva-143176 (URN)10.18261/issn.1891-5949-2017-02-05 (DOI)2-s2.0-85025650194 (Scopus ID)
    Available from: 2017-11-21 Created: 2017-11-21 Last updated: 2019-01-02Bibliographically approved
    3. Citizenship as individual responsibility through personal investment: an ethnographic study in a study circle
    Open this publication in new window or tab >>Citizenship as individual responsibility through personal investment: an ethnographic study in a study circle
    2017 (English)In: European Journal for Research on the Education and Learning of Adults, ISSN 2000-7426, E-ISSN 2000-7426Article in journal (Refereed) Published
    Abstract [en]

    The aim of this article is to shed light on how the democratic ideal of institutionalised Nordic popular education is realised through an ethnographic field study in an English as a foreign language study circle. The study focuses on how participants express their citizenship when taking part in the study circle. Citizenship is viewed as a dynamic concept comprising the aspects of ‘being’ and ‘acting’ and constructed in and through social interaction. The study circle is arranged as a classroom practice: The study circle leader organises the activities, while the participants engage in exercises and attempt to learn correct usage. Through their participation, the participants take individual responsibility for what they see as their lack of sufficient knowledge of English. The participants describe their participation as a personal and voluntary investment in themselves. In light of the study, the individual stance is discussed as limiting possibilities for responsibility and thus expressions of citizenship.

    Place, publisher, year, edition, pages
    Linköping University Electronic Press, 2017
    Keywords
    Citizenship; popular education; liberal adult education; study circle; ethnography
    National Category
    Pedagogy
    Identifiers
    urn:nbn:se:liu:diva-143175 (URN)10.3384/rela.2000-7426.relaojs99 (DOI)
    Available from: 2017-11-21 Created: 2017-11-21 Last updated: 2019-01-02Bibliographically approved
  • Fayad, Adel
    Linköping University, Department of Electrical Engineering, Communication Systems.
    Analysis and Compensationfor Clipping-like Distortion of the Transmitted Signal in Massive MIMO Systems2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This project consists of analyzing and finding solutions to the effect of non-linear distortionon the performance of a Massive Multiple Input Multiple Output (MIMO) system interms of Spectral Efficiency (SE) and Symbol Error Rate (SER). Massive MIMO is one ofthe technologies that are considered the backbone of the 5th generation of wireless communicationsand therefore this technology has gathered much interest from researchersand companies alike [19], as it is proven that this kind of system greatly improves thecapacity of the wireless connection [8]. Since Massive MIMO is still a relatively newtechnology and it is yet to be implemented for commercial use, there are several challengesthat arise when trying to implement such a system. One of these problems arisefrom the fact that the Power Amplifiers (PAs) in the transmitters of Massive MIMO systemsare non-linear and thus impose a distortion on the transmitted signals of the system[12]. The thesis aims to study this non-linear effect on the performance of massive MIMOsystems by first modelling the distortion effect on the transmitted signals using two differentnon-linear models. Moreover, closed-form expressions for one of the models areformed to facilitate the simulation of the non-linear model and facilitate the analysis ofthe distortion effect on the performance metrics. Then the established system model issimulated and based on the results, the effect of each of the power amplifier non-lineardistortion models on the performance metrics of the Massive MIMO system is studied.Furthermore, based on the analysis of the simulation results, a compensation mechanismis introduced to the Massive MIMO system in order to mitigate the distortion effect onthe system performance in terms of SER and SE.

  • Lönn, Emma
    Linköping University, Department of Behavioural Sciences and Learning.
    Samverkan som möjlighet och begränsning: Att stärka inkludering och måluppfyllelse i skolan genom samverkan2018Independent thesis Advanced level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Syftet med denna studie är att, utifrån en kvalitativ metod, analysera lärares erfarenheter och uppfattningar om samverkan i skolan. Studien undersöker hur lärares samverkan kan påverka elevers inkludering, och lärares uppfattningar om hur inkludering skapar möjligheter eller hinder för elevers måluppfyllelse. Studiens kunskapsbidrag är att ge ökade insikter om den process som uppstår, då lärares samverkan sker eller uteblir med interna och externa parter. Studien har utifrån en ekologisk systemteori och sociokulturell teori analyserat lärares erfarenheter kring samverkan i skolan. Den datainsamlingsmetod som tillämpas i studien är semistrukturerade kvalitativa intervjuer. I resultatet framkom att lärarnas erfarenhet kring samverkan för att öka måluppfyllelse och öka känslan av att vara inkluderad i skolan kan kopplas till vad lärare upplever som framgångsfaktorer och vad lärare upplever som hinder och dilemman för samverkan. Kommunikation, relationer, stöd utifrån och från ledning samt att ta vara på varandras kompetenser belyses som framgångsfaktorer. De hinder och dilemman som lärarna upplever är i form av samverkan med stora organisationer med tröga processer, otydliga roller och mål samt fel använda resurser. Detta leder till att samverkan blir kontraproduktiv eller obefintlig vilket har påverkan på elevens situation utifrån inkludering och måluppfyllelse. Dock framträder en viktig skillnad mellan lärarna rörande synen på syftet med samverkan. Samverkan för att inkludera och därmed öka måluppfyllelsen i den ordinarie verksamheten, eller att samverka för att möjliggöra att eleven lyfts ut till ett annat sammanhang där eleven kan känna sig inkluderad och därmed tillgodogöra sig kunskaper och högre måluppfyllelse än tidigare.

  • Örnerheim, Mattias
    et al.
    Linköping University, Department of Management and Engineering, Political Science. Linköping University, Faculty of Arts and Sciences.
    Elg, Mattias
    Linköping University, Department of Management and Engineering, Logistics & Quality Management. Linköping University, Faculty of Science & Engineering.
    Implementering i vården: En kunskapsöversikt om beslutsnivåer och professionsperspektiv2018Report (Other academic)
    Abstract [sv]

    Hälso- och sjukvården liksom socialtjänsten är under ständig förändring – medicinska framsteg skapar nya möjligheter till behandling samtidigt som behoven av hälso- och sjukvård och socialtjänst ökar i takt med att allt fler lever längre med kroniska sjukdomar. Socialtjänsten kommer att behöva stödja fler med långvariga och komplexa behov, vilket band annat kommer att ställa krav på ändrade arbetssätt. En fortsatt utveckling i vården och omsorgen är viktigt för att i dag och i framtiden kunna tillhandahålla en god vård och omsorg som patienter och brukare känner förtroende för.Samtidigt finns tecken på att utvecklingen och lärandet inte sker i den omfattning som behövs. I olika analyser har Vårdanalys genom åren visat att lärandet mellan olika verksamheter och huvudmän är begränsat. Orsakerna bakom det är flera.Hösten 2017 initierade vi ett forskningsuppdrag med ambitionen att utifrån litteraturen identifiera övergripande utmaningar när det gäller implementering i hälso- och sjukvården och socialtjänsten. Vi gav professor Mattias Elg och postdoktor Mattias Örnerheim vid institutionen för ekonomisk och industriell utveckling (IEI), Linköpings universitet, uppdraget att presentera en kunskapsöversikt på detta tema.Deras översikt har varit ett värdefullt bidrag till Vårdanalys arbeten under 2017 och 2018 som på olika sätt analyserat utvecklingsarbete och deras förutsättningar att bidra till långsiktig utveckling. Det är vår förhoppning att den här promemorian kan tjäna som ett kunskapsunderlag i den fortsatta diskussionen om hur vi kan skapa bättre förutsättningar till lärande och utveckling i vården och omsorgen.Den här promemorian är författarnas redovisning av forskningsuppdraget i sin helhet och de står själva för innehållet.

  • Public defence: 2019-01-18 09:00 Berzeliussalen, ingång 65, Linköping
    Fredlund, Cecilia
    Linköping University, Department of Clinical and Experimental Medicine, Center for Social and Affective Neuroscience. Linköping University, Faculty of Medicine and Health Sciences.
    Adolescents Selling Sex and Sex as Self-Injury2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    There are today only a few population-based studies in the world investigating the prevalence of and associated risk-factors with adolescents selling sex and so far no earlier population-based study has been found investigating adolescents motives for selling sex. Further, to use sex in means of self-injury (SASI) is a behaviour that has been highlighted in Sweden the last years but it is a new field of research and a behaviour in need of conceptualization.

    The aim of this thesis was to investigate the prevalence of, associated risk factors with, motives for and manifestations of adolescents selling sex and the use of sex as self-injury (SASI). For the thesis, two nationally representative cross-sectional population surveys with third year students at Swedish high schools were collected in 2009 (n = 3498, mean age 18.3 +/- 0.6 years, response rate 60.4%) and in 2014 (n = 5839, mean age 18.0 +/- 0.6 years, response rate 59.7%). Further, the motives and manifestations of SASI were investigated in an anonymous self-selected, open-ended questionnaire published on websites of non-governmental organizations offering help and support to women and adolescents (n = 199, mean age 27.9 +/- 9.3 years). Quantitative and qualitative methods were used for data analyses.

    In the 2009 population-based survey, 1.5% (n = 51) of the adolescents reported having sold sex on at least one occasion, but in 2014 the prevalence was slightly lower at 0.9% (n = 51). SASI was reported by 3.2% of girls (n = 100) and 0.8% of boys (n = 20). Both selling sex and SASI were associated with various adverse factors such as experience of sexual abuse, emotional and physical abuse, poor mental health and self-injury. Adolescents selling sex had sought help and support for different problems and worries to a greater extent compared to peers. Contact with healthcare for various psychiatric problems such as suicide attempts, depression and eating disorders was common for adolescents using SASI. Further analysis showed that adolescents selling sex are a heterogeneous group in regard to underlying motives for selling sex, which included emotional and material reasons as well as pleasure. Depending on their underlying motives, adolescents selling sex were found to differ in regard to compensation received, age of the buyer, means of contact with the buyer, sexual orientation, experience of sexual abuse and the use of SASI. By using data from an open-ended questionnaire, SASI was described as deliberate or self-inflicted sexual situations that could include psychological and physical harm. SASI was used as a way to regulate negative feelings, such as anxiety, or to get positive or negative confirmation and the behaviour could be hard to stop.

    In conclusion, selling sex and SASI occurs among Swedish adolescents and the behaviours are associated with sexual, physical and emotional abuse and poor mental health, including trauma symptoms. In regard of the motives and manifestations of SASI, the behaviour could be compared to direct self-injurious behaviours. Data from this thesis suggest that more attention should be paid in healthcare to recognizing adolescents selling sex and SASI in order to prevent further traumatization and victimization.

    List of papers
    1. Adolescents selling sex: Exposure to abuse, mental health, self-harm behaviour and the need for help and support - a study of a Swedish national sample
    Open this publication in new window or tab >>Adolescents selling sex: Exposure to abuse, mental health, self-harm behaviour and the need for help and support - a study of a Swedish national sample
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    2013 (English)In: Nordic Journal of Psychiatry, ISSN 0803-9488, E-ISSN 1502-4725, Vol. 67, no 2, p. 81-88Article in journal (Refereed) Published
    Abstract [en]

    Selling sex is not uncommon among adolescents and we need to increase our knowledge of how this affects them. The aim of this study was to investigate adolescents who sell sex regarding sexual, mental and physical abuse, mental health as estimated by using the Hopkins Symptom Check List-25 (HSCL-25), self-harm behaviour and the adolescents' experience of receiving help and support. The study was carried out on a national representative sample of adolescents (mean age 18.3 years) in Swedish high schools in the final year of their 3-year programme. The study had 3498 participants and a response rate of 60.4%. Of the adolescents, 1.5% stated that they had sold sexual services. The selling of sex was associated with a history of sexual, mental and physical abuse. Poorer mental health and a higher degree of self-harm behaviour were reported among the adolescents who had sold sex. Help and support was sought to a greater extent by adolescents who had sold sex but these adolescents were not as satisfied with this help and support as the other adolescents. Adolescents that sell sex are a group especially exposed to sexual, mental and physical abuse. They have poorer metnal health and engage in more self-harm behaviour than other adolescents. They are in need of more help and support than other adolescents ant it is reasonable to assert that more resources, research and attention should be directed to this group to provide better help and support in the future.

    Place, publisher, year, edition, pages
    Informa Healthcare, 2013
    Keywords
    adolescents, child abuse, help and support, mental health, self-harm behaviour, selling sex
    National Category
    Other Medical Sciences
    Identifiers
    urn:nbn:se:liu:diva-91850 (URN)10.3109/08039488.2012.679968 (DOI)000316956800001 ()
    Available from: 2013-05-03 Created: 2013-05-03 Last updated: 2018-12-21Bibliographically approved
    2. Adolescents motives for selling sex in a welfare state - A Swedish national study
    Open this publication in new window or tab >>Adolescents motives for selling sex in a welfare state - A Swedish national study
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    2018 (English)In: International Journal of Child Abuse & Neglect, ISSN 0145-2134, E-ISSN 1873-7757, Vol. 81, p. 286-295Article in journal (Refereed) Published
    Abstract [en]

    In addition to money or other compensation, other motives for selling sex may be important in a welfare country such as Sweden. The aim of this study was to carry out an exploratory investigation of adolescents motives for selling sex in a population-based survey in Sweden. A total of 5839 adolescents from the third year of Swedish high school, mean age 18.0 years, participated in the study. The response rate was 59.7% and 51 students (0.9%) reported having sold sex. Exploratory factor analysis and hierarchical cluster analysis were used to identify groups of adolescents according to underlying motives for selling sex. Further analyses were carried out for characteristics of selling sex and risk factors. Three groups of adolescents were categorized according to their motives for selling sex: Adolescents reporting; 1) Emotional reasons, being at a greater risk of sexual abuse, using sex as a means of self-injury and having a non-heterosexual orientation. 2) Material but no Emotional reasons, who more often receive money as compensation and selling sex to a person over 25 years of age, and 3) Pleasure or no underlying motive for selling sex reported, who were mostly heterosexual males selling sex to a person under 25 years of age, the buyer was not known from the Internet, the reward was seldom money and this group was less exposed to penetrative sexual abuse or using sex as a means of self-injury. In conclusion, adolescents selling sex are a heterogeneous group in regard to underlying motives.

    Place, publisher, year, edition, pages
    PERGAMON-ELSEVIER SCIENCE LTD, 2018
    Keywords
    Selling sex; Adolescent; Child sexual exploitation; Motives; Prostitution
    National Category
    Psychiatry
    Identifiers
    urn:nbn:se:liu:diva-149697 (URN)10.1016/j.chiabu.2018.04.030 (DOI)000436375800026 ()29775872 (PubMedID)
    Note

    Funding Agencies|Ministry of Health and Social Affairs/the Childrens Welfare Foundation Sweden; County of Stockholm, Sweden

    Available from: 2018-07-24 Created: 2018-07-24 Last updated: 2018-12-21
    3. Self-reported frequency of sex as self-injury (SASI) in a national study of Swedish adolescents and association to sociodemographic factors, sexual behaviors, abuse and mental health
    Open this publication in new window or tab >>Self-reported frequency of sex as self-injury (SASI) in a national study of Swedish adolescents and association to sociodemographic factors, sexual behaviors, abuse and mental health
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    2017 (English)In: Child and Adolescent Psychiatry and Mental Health, ISSN 1753-2000, E-ISSN 1753-2000, Vol. 11, no 1Article in journal (Refereed) Published
    Abstract [en]

    Sex as self-injury has become a concept in Swedish society; however it is a largely unexplored area of research, not yet conceptualized and far from accepted in the research field. The use of sex as a way of affect regulation is known in the literature and has, in interviews with young women who sell sex, been compared to direct self-injury, such as cutting or burning the skin. The aim of this study was to investigate the self-reported frequency of sex as self-injury and the association to sociodemographic factors, sexual orientation, voluntary sexual experiences, sexual risk-taking behaviors, sexual, physical and mental abuse, trauma symptoms, healthcare for psychiatric disorders and non-suicidal self-injury.

    Place, publisher, year, edition, pages
    BioMed Central, 2017
    National Category
    Neurosciences Rheumatology and Autoimmunity Psychiatry
    Identifiers
    urn:nbn:se:liu:diva-134927 (URN)10.1186/s13034-017-0146-7 (DOI)000395328600001 ()
    Available from: 2017-03-02 Created: 2017-03-02 Last updated: 2018-12-21Bibliographically approved
  • Olausson, Albin
    et al.
    Linköping University, Department of Management and Engineering, Political Science. Linköping University, Faculty of Arts and Sciences.
    Syssner, Josefina
    Linköping University, Department for Studies of Social Change and Culture, Centre for Municipality Studies – CKS. Linköping University, Faculty of Arts and Sciences.
    Mot en ny lokal utvecklingspolitik?: Om svenska kommuners arbete för en stärkt lokal attraktionskraft2018Report (Other academic)
    Abstract [sv]

    Svenska kommuner gör varje år åtskilliga insatser i syfte att främja den egna kommunens attraktivitet, konkurrenskraft eller tillväxtpotential. I forskningslitteraturen går dessa insatser ofta under benämningen lokal utvecklingspolitik. I denna rapport undersöks hur lokalt utvecklingsarbete egentligen går till. Vad gör kommunerna och med vilka metoder? Hur väcks utvecklingspolitiska initiativ? Och hur organiseras genomförandet av utvecklingspolitiken?

    Rapporten bygger på ett interaktivt följeforskningsprojekt där författarna under tre år har följt lokala utvecklingsinitiativ i tio kommuner runt om i Sverige. De studerade kommunerna har under undersökningsperioden ingått i Tillväxtverkets projekt Stärkt lokal attraktionskraft, 2015-2018.

    I de fyra resultatkapitlen beskrivs 1) hur kommunala företrädare strategiskt ser på kommunens roll och funktion i det lokala utvecklingsarbetet, 2) vilka metoder kommunerna utvecklar och arbetar med, 3) hur utvecklingsinsatser förankras och blir legitima under okonventionella policyprocesser samt 4) vilka roller utvecklingsprofessionella tjänstepersoner har i utvecklingspolitikens policyprocesser.

    Resultaten i denna studie kan förstås i ljuset av en mer övergripande policyförändring som äger rum på det regionalpolitiska området. Tidigare har lokal och regional utvecklingspolitik varit direkt associerat med näringslivsutveckling och skapande av nya arbetstillfällen. Vi menar dock att en annan bredare form av utvecklingspolitik håller på att ta form, inte minst på den lokala nivån. Denna nya utvecklingspolitik fokuserar på samhällsutveckling i vid mening. Ofta betyder det att frågorna är svåra för kommunen att styra och att de inte enkelt kan inordnas under någon traditionell politisk sektor (förvaltning).

    Med denna policyförändring för ögonen ser vi att kommunerna hittills har haft svårt att finna arbetssätt, metoder och organisationsformer som matchar den breda, interaktiva och tvärsektoriella utvecklingspolitiken. Resultaten visar att kommunerna uttrycker en tydlig diskrepans mellan hur de vill jobba och hur de tycker att de faktiskt jobbar. Vidare är metodutvecklingen på området fokuserad på intern organisations- och processutveckling. De utvecklingsinitiativ som studerats har ofta initierats och drivits av enskilda medarbetare som inte sällan saknat organisatoriska stödstrukturer för tvärsektoriellt och interaktivt arbete. Därtill har dessa medarbetare ibland mött legitimitetsproblem när deras arbete saknar förankring eller när olika legitimitetsgrunder har krockat med varandra.