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  • 1.
    Erni, Jonas
    et al.
    Linköping University, Department of Management and Engineering, Business Administration. Linköping University, Faculty of Arts and Sciences.
    Smedberg, Kåre
    Linköping University, Department of Management and Engineering, Business Administration. Linköping University, Faculty of Arts and Sciences.
    2011 års uppdatering av Skuldsaneringslagen (2006:548): En granskning av hur uppdateringen påverkat enskilda näringsidkare och borgenärer2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Background

    The Government considered despite the introduction of the 1994 debt rescheduling act (1994:334) that a solution was needed to the problem that individual traders neither could be granted debt relief or corporate restructuring to thus be able to continue operations if they got into financial insolvency. Therefore in 2007 a special investigator was added to investigate and make proposals for debt relief for individual traders. This study was the basis for the Government bill that the Parliament in October 2010 decided upon.

    The main issue

    What impact has the new debt rescheduling act meant for traders as well as creditors?

    Purpose

    Our purpose of the bachelor thesis is to explore if the new debt rescheduling act (2006:548) has achieved the expected goals, the study will also investigate if the new debt rescheduling act has resulted in any other effects.

    Method

    The study's purpose is answered by a personal interview and several questionnaires that have been collected for the empirical material. The processing of the empirical material was made by a qualitative method. Referrals and propositions have also been used to help answer the bachelor thesis purpose, when the reference frame and the conclusion were set against each other.

    Conclusion

    The actual impact of the new debt rescheduling act (2006:548) is that individual traders can get debt relief if the insolvency was because the trader could not work for a long period of time and therefore ended up in financial trouble. In an insolvency situation the age of the debts are not considered in the same way as before, which meant that a debtor can apply for debt relief in an earlier stage. That this would contribute to deterioration in payment behavior and elevated interest rates appears unchanged. At the change of a criterion such as the age of the debt, a clear effect on the number of debt applications can be seen.

  • 2.
    Auer, Cornelia
    et al.
    Zuse Institute Berlin, Berlin, Germany.
    Nair, Jaya
    IIIT – Bangalore, Electronics City, Hosur Road, Bangalore, India.
    Zobel, Valentin
    Zuse Institue Berlin, Berlin, Germany.
    Hotz, Ingrid
    Zuse Institue Berlin, Berlin, Germany.
    2D Tensor Field Segmentation2011In: Dagstuhl Follow-Ups, E-ISSN 1868-8977, Vol. 2, 17-35 p.Article in journal (Refereed)
    Abstract [en]

    We present a topology-based segmentation as means for visualizing 2D symmetric tensor fields. The segmentation uses directional as well as eigenvalue characteristics of the underlying field to delineate cells of similar (or dissimilar) behavior in the tensor field. A special feature of the resulting cells is that their shape expresses the tensor behavior inside the cells and thus also can be considered as a kind of glyph representation. This allows a qualitative comprehension of important structures of the field. The resulting higher-level abstraction of the field provides valuable analysis. The extraction of the integral topological skeleton using both major and minor eigenvector fields serves as a structural pre-segmentation and renders all directional structures in the field. The resulting curvilinear cells are bounded by tensorlines and already delineate regions of equivalent eigenvector behavior. This pre-segmentation is further adaptively refined to achieve a segmentation reflecting regions of similar eigenvalue and eigenvector characteristics. Cell refinement involves both subdivision and merging of cells achieving a predetermined resolution, accuracy and uniformity of the segmentation. The buildingblocks of the approach can be intuitively customized to meet the demands or different applications. Application to tensor fields from numerical stress simulations demonstrates the effectiveness of our method.

  • 3. Comina, German
    et al.
    Suska, Anke
    Linköping University, Department of Physics, Chemistry and Biology, Chemical and Optical Sensor Systems. Linköping University, Faculty of Science & Engineering.
    Filippini, Daniel
    Linköping University, Department of Physics, Chemistry and Biology, Chemical and Optical Sensor Systems. Linköping University, Faculty of Science & Engineering.
    3D Printed Unibody Lab-on-a-Chip: Features Survey and Check-Valves Integration dagger2015In: Micromachines, ISSN 2072-666X, E-ISSN 2072-666X, Vol. 6, no 4, 437-451 p.Article in journal (Refereed)
    Abstract [en]

    The unibody lab-on-a-chip (ULOC) concept entails a fast and affordable micro-prototyping system built around a single monolithic 3D printed element (unibody). A consumer-grade stereo lithography (SL) 3D printer can configure ULOCs with different forms of sample delivery, transport, handling and readout, while minimizing material costs and fabrication time. ULOC centralizes all complex fabrication procedures and replaces the need for clean room resources, delivering prototypes for less than 1 US$, which can be printed in 10 min and ready for testing in less than 30 min. Recent examples of ULOC integration of transport, chemical sensing for optical readout and flow mixing capabilities are discussed, as well as the integration of the first check-valves for ULOC devices. ULOC valves are strictly unidirectional up to 100 psi, show an exponential forward flow behavior up to 70 psi and can be entirely fabricated with the ULOC approach.

  • 4.
    Andersson, Gerhard
    et al.
    Linköping University, Department of Behavioural Sciences and Learning, Psychology. Linköping University, Faculty of Arts and Sciences. Karolinska Institute, Sweden.
    Topooco, Naira
    Linköping University, Department of Behavioural Sciences and Learning, Psychology. Linköping University, Faculty of Arts and Sciences.
    Havik, Odd
    University of Bergen, Norway; Haukeland Hospital, Norway.
    Nordgreen, Tine
    University of Bergen, Norway; Haukeland Hospital, Norway.
    6 Internet-supported versus face-to-face cognitive behavior therapy for depression2016In: Expert Review of Neurotherapeutics, ISSN 1473-7175, E-ISSN 1744-8360, Vol. 16, no 1, 55-60 p.Article, review/survey (Refereed)
    Abstract [en]

    Major depression and depressive symptoms are highly prevalent and there is a need for different forms of psychological treatments that can be delivered from a distance at a low cost. In the present review the authors contrast face-to-face and Internet-delivered cognitive behavior therapy (ICBT) for depression. A total of five studies are reviewed in which guided ICBT was directly compared against face-to-face CBT. Meta-analytic summary statistics were calculated for the five studies involving a total of 429 participants. The average effect size difference was Hedges g=0.12 (95% CI: -0.06-0.30) in the direction of favoring guided ICBT. The small difference in effect has no implication for clinical practice. The overall empirical status of clinician-guided ICBT for depression is commented on and future challenges are highlighted. Among these are developing treatments for patients with more severe and long-standing depression and for children, adolescents and the elderly. Also, there is a need to investigate mechanisms of change.

  • 5.
    Heimann, Mikael
    et al.
    University of Bergen, Norway.
    Nilheim, Katarina
    Göteborg University, Sweden.
    6-month-olds and delayed actions: An early sign of an early explicit memory?2004In: Cogniţie, Creier, Comportament/Cognition, Brain, Behavior, ISSN 1224-8398, Vol. VIII, no 3-4, 249-254 p.Article in journal (Refereed)
    Abstract [en]

    In 1996 Barr, Dowden and Hayne reported that 6 month old infants imitate new actions with objects after a substantial delay. This is a finding in need of independent replications and the study reported here presents one such attempt. Forty-five 6 months old Swedish infants (22 girls) participated in the study. They were randomly assigned to either an experimental (n=30) or acontrol condition (n=15). The procedure replicates the method used by Barret al. with one exception: The imposed delay was 10 minutes instead of 24 hours. Overall it was found that the children in the imitation group displayed significantly more target acts than the children in the control group and it is concluded that infants are capable of using deferred imitation as means for learning new actions already at 6 months.

  • 6.
    Clark, Charlotte
    et al.
    Queen Mary University of London, England .
    Sörqvist, Patrik
    Linköping University, Faculty of Arts and Sciences. Linköping University, Department of Behavioural Sciences and Learning.
    A 3 year update on the influence of noise on performance and behavior2012In: Noise & Health, ISSN 1463-1741, E-ISSN 1998-4030, Vol. 14, no 61, 292-296 p.Article in journal (Refereed)
    Abstract [en]

    The effect of noise exposure on human performance and behavior continues to be a focus for research activities. This paper reviews developments in the field over the past 3 years, highlighting current areas of research, recent findings, and ongoing research in two main research areas: Field studies of noise effects on childrens cognition and experimental studies of auditory distraction. Overall, the evidence for the effects of external environmental noise on childrens cognition has strengthened in recent years, with the use of larger community samples and better noise characterization. Studies have begun to establish exposure-effect thresholds for noise effects on cognition. However, the evidence remains predominantly cross-sectional and future research needs to examine whether sound insulation might lessen the effects of external noise on childrens learning. Research has also begun to explore the link between internal classroom acoustics and childrens learning, aiming to further inform the design of the internal acoustic environment. Experimental studies of the effects of noise on cognitive performance are also reviewed, including functional differences in varieties of auditory distraction, semantic auditory distraction, individual differences in susceptibility to auditory distraction, and the role of cognitive control on the effects of noise on understanding and memory of target speech materials. In general, the results indicate that there are at least two functionally different types of auditory distraction: One due to the interruption of processes (as a result of attention being captured by the sound), another due to interference between processes. The magnitude of the former type is related to individual differences in cognitive control capacities (e.g., working memory capacity); the magnitude of the latter is not. Few studies address noise effects on behavioral outcomes, emphasizing the need for researchers to explore noise effects on behavior in more detail.

  • 7.
    Andersson, Gerhard
    et al.
    Linköping University, Department of Behavioural Sciences and Learning, Psychology. Linköping University, Faculty of Arts and Sciences.
    Hesser, Hugo
    Linköping University, The Swedish Institute for Disability Research. Linköping University, Department of Behavioural Sciences and Learning, Psychology. Linköping University, Faculty of Arts and Sciences.
    Hummerdal, Daniel
    Linköping University, Department of Behavioural Sciences and Learning. Linköping University, Faculty of Arts and Sciences.
    Bergman Nordgren, Lise
    Linköping University, The Swedish Institute for Disability Research. Linköping University, Department of Behavioural Sciences and Learning, Psychology. Linköping University, Faculty of Arts and Sciences.
    Carlbring, Per
    Linköping University, The Swedish Institute for Disability Research. Linköping University, Faculty of Arts and Sciences. Department of Psychology , Umeå University, Umeå, Sweden.
    A 3.5-year follow-up of Internet-delivered cognitive behavior therapy for major depression2013In: Journal of Mental Health, ISSN 0963-8237, E-ISSN 1360-0567, Vol. 22, no 2, 155-164 p.Article in journal (Refereed)
    Abstract [en]

    BackgroundInternet-delivered cognitive behavior therapy (ICBT) for major depression has been tested in several trials, but only with follow-ups up to 1.5 years.

    AimThe aim of this study was to evaluate the outcome of ICBT 3.5 years after treatment completion.Methods

    A total of 88 people with major depression were randomized to either guided self-help or e-mail therapy in the original trial. One-third was initially on a waiting-list. Treatment was provided for eight weeks and in this report long-term follow-up data were collected. Also included were data from post-treatment and six-month follow-up. A total of 58% (51/88) completed the 3.5-year follow-up. Analyses were performed using a random effects repeated measures piecewise growth model to estimate trajectory shape over time and account for missing data.

    ResultsResults showed continued lowered scores on the Beck Depression Inventory (BDI). No differences were found between the treatment conditions. A large proportion of participants (55%) had sought and received additional treatments in the follow-up period. A majority (56.9%) of participants had a BDI score lower than 10 at the 3.5-year follow-up.

    ConclusionsPeople with mild to moderate major depression may benefit from ICBT 3.5-years after treatment completion.

  • 8.
    Hedman, Erik
    et al.
    Karolinska University Hospital.
    Furmark, Tomas
    Uppsala University.
    Carlbring, Per
    Umea University.
    Ljotsson, Brjann
    Karolinska University Hospital.
    Ruck, Christian
    Karolinska University Hospital.
    Lindefors, Nils
    Karolinska University Hospital.
    Andersson, Gerhard
    Linköping University, Department of Behavioural Sciences and Learning, Clinical and Social Psychology. Linköping University, Faculty of Arts and Sciences. Linköping University, Department of Behavioural Sciences and Learning, Psychology.
    A 5-Year Follow-up of Internet-Based Cognitive Behavior Therapy for Social Anxiety Disorder2011In: Journal of Medical Internet Research, ISSN 1438-8871, E-ISSN 1438-8871, Vol. 13, no 2Article in journal (Refereed)
    Abstract [en]

    Background: Internet-based cognitive behavior therapy (CBT) has been shown to be a promising method to disseminate cognitive behavior therapy for social anxiety disorder (SAD). Several trials have demonstrated that Internet-based CBT can be effective for SAD in the shorter term. However, the long-term effects of Internet-based CBT for SAD are less well known. less thanbrgreater than less thanbrgreater thanObjective: Our objective was to investigate the effect of Internet-based CBT for SAD 5 years after completed treatment. less thanbrgreater than less thanbrgreater thanMethod: We conducted a 5-year follow-up study of 80 persons with SAD who had undergone Internet-based CBT. The assessment comprised a diagnostic interview and self-report questionnaires. The main outcome measure was the Liebowitz Social Anxiety Scale-Self-Report (LSAS-SR). Additional measures of social anxiety were the Social Interaction Anxiety Scale (SIAS) and the Social Phobia Scale (SPS). Attrition rates were low: 89% (71/80) of the participants completed the diagnostic interview and 80% (64/80) responded to the questionnaires. less thanbrgreater than less thanbrgreater thanResults: Mixed-effect models analysis showed a significant effect of time on the three social anxiety measures, LSAS-SR, SIAS, and SPS (F(3,98-102) = 16.05 -29.20, P andlt; .001) indicating improvement. From baseline to 5-year follow-up, participants mean scores on the LSAS-SR were reduced from 71.3 (95% confidence interval [CI] 66.1-76.5) to 40.3 (95% CI 35.2 - 45.3). The effect sizes of the LSAS-SR were large (Cohens d range 1.30 - 1.40, 95% CI 0.77 - 1.90). Improvements gained at the 1-year follow-up were sustained 5 years after completed treatment. less thanbrgreater than less thanbrgreater thanConclusions: Internet-based CBT for SAD is a treatment that can result in large and enduring effects. Trial registration: Clinicaltrials.gov NCT01145690; http://clinicaltrials.gov/ct2/show/NCT01145690 (Archived by WebCite at http://www.webcitation.org/5ygRxDLfK)

  • 9.
    Härkegård, Ola
    et al.
    Linköping University, Department of Electrical Engineering, Automatic Control. Linköping University, The Institute of Technology.
    Glad, Torkel
    Linköping University, Department of Electrical Engineering, Automatic Control. Linköping University, The Institute of Technology.
    A Backstepping Design for Flight Path Angle Control2000In: Proceedings of the 39th IEEE Conference on Decision and Control, 2000, 3570-3575 p.Conference paper (Refereed)
    Abstract [en]

    A nonlinear approach to flight path angle control is presented. Using backstepping, a globally stabilizing control law is derived. Although the nonlinear nature of the lift force is considered, the pitching moment to be produced is only linear in the measured states. Thus, the resulting control law is much simpler than if feedback linearization had been used. The free parameters that spring from the backstepping design are used to achieve a desired linear behavior around the operating point.

  • 10.
    Härkegård, Ola
    et al.
    Linköping University, Department of Electrical Engineering, Automatic Control. Linköping University, The Institute of Technology.
    Glad, Torkel
    Linköping University, Department of Electrical Engineering, Automatic Control. Linköping University, The Institute of Technology.
    A Backstepping Design for Flight Path Angle Control2000Report (Other academic)
    Abstract [en]

    A nonlinear approach to flight path angle control is presented. Using backstepping, a globally stabilizing control law is derived. Although the nonlinear nature of the lift force is considered, the pitching moment to be produced is only linear in the measured states. Thus, the resulting control law is much simpler than if feedback linearization had been used. The free parameters that spring from the backstepping design are used to achieve a desired linear behavior around the operating point.

  • 11.
    Saifullah, Mohammad
    Linköping University, Department of Computer and Information Science. Linköping University, The Institute of Technology.
    A Biologically Inspired Model for Occluded Patterns2011In: Neural Information Processing: proceedings of the 18th International Conference on Neural Information Processing, ICONIP 2011,  Shanghai, China, November 2011., 2011, 88-96 p.Conference paper (Refereed)
    Abstract [en]

    In this paper a biologically-inspired model for partly occluded patterns is proposed. The model is based on the hypothesis that in human visual system occluding patterns play a key role in recognition as well as in reconstructing internal representation for a pattern’s occluding parts. The proposed model is realized with a bidirectional hierarchical neural network. In this network top-down cues, generated by direct connections from the lower to higher levels of hierarchy, interact with the bottom-up information, generated from the un-occluded parts, to recognize occluded patterns. Moreover, positional cues of the occluded as well as occluding patterns, that are computed separately but in the same network, modulate the top-down and bottom-up processing to reconstruct the occluded patterns. Simulation results support the presented hypothesis as well as effectiveness of the model in providing a solution to recognition of occluded patterns. The behavior of the model is in accordance to the known human behavior on the occluded patterns.

  • 12.
    Saifullah, Mohammad
    Linköping University, Department of Computer and Information Science. Linköping University, The Institute of Technology.
    A Biologically-Inspired Model for Recognition of Overlapped Patterns2011In: Proceedings International ICST Conference on Bio-Inspired Models of Network, Information and Computing Systems, 2011Conference paper (Refereed)
    Abstract [en]

    In this paper a biologically-inspired model for recognition of overlapped patterns is proposed. Information processing in the two visual information processing pathways, i.e., the dorsal and the ventral pathway, is modeled as a solution to the problem. We hypothesize that dorsal pathway, in addition to encoding the spatial information, learns the shape representation of the patterns and, later uses this knowledge as a top-down guidance signal to segment the bottom-up, image-based saliency map. This process of segmentation in the dorsal pathway is implemented as an interactive process, where interaction between bottom-up image information and top-down shape cues lead to incremental development of a segmented saliency map for one of the overlapped object at a time. This segmented map encodes spatial as well as shape information of the respective pattern in the input. The interaction of the dorsal channel with the ventral channel leads to modulation and selective processing of the respective pattern in the ventral pathway for final recognition. Simulation results support the presented hypothesis as well as effectiveness of the model in providing a solution to the recognition of overlapped patterns. The behavior of the model is in accordance to the known human behavior on the occluded patterns.

  • 13.
    Agnafors, Sara
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences. Västra Götalandsregionen, Södra Älvsborgs Sjukhus, Barn- och ungdomspsykiatriska kliniken.
    A Biopsychosocial and Long Term Perspective on Child Behavioral Problems: Impact of Risk and Resilience2016Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Mental health has become a prominent issue in society. Yet, much remains unknown about the etiology of psychiatric disorders. The aim of the present thesis was to investigate the association between biological, psychological and social factors of risk and resilience and behavioral problems in a birth cohort of Swedish children. 1723 mothers and their children were followed from birth to the age of 12 as part of the South East Sweden Birth Cohort Study (the SESBiC study). Information was gathered through register data, standardized questionnaires and DNA samples.

    In study I, stability of maternal symptoms of depression and the impact on child behavior at age 12 were investigated. The prevalence of depressive symptoms was found to be 12.0 % postpartum. Symptoms of postpartum depression significantly increased the risk for subsequent depressive symptoms 12 years later in women. Children whose mothers reported concurrent symptoms of depression and anxiety had an increased risk for both internalizing and externalizing problems at age 12, but no long term effect on child behavior was seen for postpartum depressive symptoms. The greatest risk was seen for children whose mothers reported symptoms of depression on both occasions. In study II, the impact of gene-environment interaction of 5-HTTLPR and BDNF Val66Met and experience of life events together with symptoms of maternal depression and anxiety on child behavior at age 12 was studied. A main effect of 5-HTTLPR was noticed, but no geneenvironment effects were shown. Similarly to study I, concurrent symptoms of maternal depression and anxiety were an important predictor of child behavioral problems. A high degree of psychosocial stress around childbirth was found to have long lasting detrimental effects on child behavior, increasing the risk for internalizing problems at age 12. Study III investigated the impact of geneenvironment interactions of 5-HTTLPR and BDNF Val66Met and life events together with symptoms of maternal depression and birth characteristics on behavioral problems at age 3. Symptoms of postpartum depression were found to predict internalizing as well as externalizing problems in children three years later. Child experience of life events was a stable predictor of behavioral problems across the scales similar to sociodemographic factors such as parental immigration status and unemployment. No gene-environment interaction effects of 5-HTTLPR or BDNF Val66Met were shown. Study IV used the risk factors identified in studies I-III to investigate factors of resilience to behavioral problems at age 12. The l/l genotype of 5-HTTLPR was associated with a lower risk for behavioral problems at age 12, especially for children facing low adversity. Good social functioning was found to be a general resource factor, independent of the level of risk, while an easy temperament was associated with resilience for children with a high degree of adversity. However, effect sizes were small.

    In summary, the results from the present thesis emphasize the importance of maternal mental health and sociodemographic factors for child mental health at ages 3 and 12, which must be taken into account in clinical settings. Moreover, it adds to the null-findings of the gene-environment effect of 5-HTTLPR and BDNF Val66Met on behavioral problems in children, but indicates a main effect of 5-HTTLPR on internalizing symptoms at age 12.

    List of papers
    1. Symptoms of Depression Postpartum and 12 years Later-Associations to Child Mental Health at 12 years of Age
    Open this publication in new window or tab >>Symptoms of Depression Postpartum and 12 years Later-Associations to Child Mental Health at 12 years of Age
    2013 (English)In: Maternal and Child Health Journal, ISSN 1092-7875, E-ISSN 1573-6628, Vol. 17, no 3, 405-414 p.Article in journal (Refereed) Published
    Abstract [en]

    Children of depressed mothers have been shown to express behaviour problems to a greater extent than children of non-depressed mothers. The purpose of this study was to examine the persistence of depressive symptoms in mothers and to evaluate the relative importance of symptoms of postpartum depression (PPD) and concurrent maternal symptoms of depression, on child behaviour at age 12. A birth cohort of 1,707 children and their mothers was followed from 3 months after birth to 12 years after birth. Self-reported symptoms of depression in mothers were assessed at baseline and 12-year follow-up where 893 mothers (52.3 %) and their children participated. The mothers reports on the behaviour of their children at age 12 were used. Multivariate analysis was used to assess factors that increased the risk of child behaviour problems. At baseline, 10.4 % scored above the cutoff for symptoms of postpartum depression. At follow up, 18.2 % scored above the cutoff for depressive symptoms. Multivariate analysis showed that ongoing maternal symptoms of depression, as distinct from PPD-symptoms, was the strongest predictor of child behaviour problems at age 12. The gender of the child and socio-demographic factors at baseline were additional factors that affected the risk of behaviour problems in the 12 year old children. Children of mothers who reported symptoms of depression, both postpartum and at follow-up, were at a greater risk of behaviour problems compared to children of women with no depressive symptoms on either occasion. Our findings indicate that recurrent and ongoing maternal depressive symptoms significantly increase the risk of child behaviour problems as reported by mothers, while symptoms of PPD do not seem to result in an increased risk of behaviour problems in 12 year olds. High maternal socio-demographic life stress at childbirth constitutes an important risk factor for later child behaviour problems.

    Place, publisher, year, edition, pages
    Springer Verlag (Germany), 2013
    Keyword
    CBCL, Children, Mental health, Postpartum depression, SESBiC-study
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-90750 (URN)10.1007/s10995-012-0985-z (DOI)000316021200003 ()
    Available from: 2013-04-05 Created: 2013-04-05 Last updated: 2017-12-06
    2. Effect of gene, environment and maternal depressive symptoms on pre-adolescence behavior problems - a longitudinal study.
    Open this publication in new window or tab >>Effect of gene, environment and maternal depressive symptoms on pre-adolescence behavior problems - a longitudinal study.
    Show others...
    2013 (English)In: Child and Adolescent Psychiatry and Mental Health, ISSN 1753-2000, E-ISSN 1753-2000, Vol. 7, no 1, 10- p.Article in journal (Refereed) Published
    Abstract [en]

    BACKGROUND: Depression is a common and disabling condition with a high relapse frequency. Maternal mental health problems and experience of traumatic life events are known to increase the risk of behavior problems in children. Recently, genetic factors, in particular gene-by-environment interaction models, have been implicated to explain depressive etiology. However, results are inconclusive.

    METHODS: Study participants were members of the SESBiC-study. A total of 889 mothers and their children were followed during the child's age of 3 months to 12 years. Information on maternal depressive symptoms was gathered postpartum and at a 12 year follow-up. Mothers reported on child behavior and traumatic life events experienced by the child at age 12. Saliva samples were obtained from children for analysis of 5-HTTLPR and BDNF Val66Met polymorphisms.

    RESULTS: Multivariate analysis showed a significant association between maternal symptoms of depression and anxiety, and internalizing problems in 12-year-old children (OR 5.72, 95% CI 3.30-9.91). Furthermore, carriers of two short alleles (s/s) of the 5-HTTLPR showed a more than 4-fold increased risk of internalizing problems at age 12 compared to l/l carriers (OR 4.73, 95% CI 2.14-10.48). No gene-by-environment interaction was found and neither depressive symptoms postpartum or traumatic experiences during childhood stayed significant in the final model.

    CONCLUSIONS: Concurrent maternal symptoms of depression and anxiety are significant risk factors for behavior problems in children, which need to be taken into account in clinical practice. Furthermore, we found a main effect of 5-HTTLPR on internalizing symptoms in 12-year-old children, a finding that needs to be confirmed in future studies.

    Place, publisher, year, edition, pages
    BioMed Central, 2013
    National Category
    Psychiatry
    Identifiers
    urn:nbn:se:liu:diva-104869 (URN)10.1186/1753-2000-7-10 (DOI)23518193 (PubMedID)
    Available from: 2014-02-28 Created: 2014-02-28 Last updated: 2017-12-05Bibliographically approved
    3. Early predictors of behavioural problems in pre-schoolers: a longitudinal study of constitutional and environmental main and interaction effects
    Open this publication in new window or tab >>Early predictors of behavioural problems in pre-schoolers: a longitudinal study of constitutional and environmental main and interaction effects
    Show others...
    2016 (English)In: BMC Pediatrics, ISSN 1471-2431, E-ISSN 1471-2431, Vol. 16Article in journal (Refereed) Published
    Abstract [en]

    Background: The early environment is important for child development and wellbeing. Gene-by-environment studies investigating the impact of the serotonin transporter genelinked polymorphic region (5-HTTLPR) and the Brain Derived Neurotrophic Factor (BDNF) Val66Met polymorphisms by life events on mental health and behaviour problems have been inconclusive. Methodological differences regarding sample sizes, study population, definitions of adversities and measures of mental health problems obstacle their comparability. Furthermore, very few studies included children. The aim of this study was to examine the associations between a broad range of risk factors covering pregnancy and birth, genetic polymorphism, experience of multiple life events and psychosocial environment, and child behaviour at age three, using a comparably large, representative, population-based sample.

    Methods: A total of 1,106 children, and their mothers, were followed from pregnancy to age three. Information on pregnancy and birth-related factors was retrieved from the Medical Birth Register. Questionnaires on depressive symptoms, child behaviour and child experiences of life events were filled in by the mothers. Child saliva samples were used for genotyping the 5-HTTLPR and BDNF Val66Met polymorphisms. Multiple logistic regression was used to investigate the association between psychological scales and genetic polymorphisms.

    Results: Symptoms of postpartum depression increased the risk of both internalizing and externalizing problems. Experience of multiple life events was also a predictor of behavioural problems across the scales. No gene-by-environment or gene-bygene-by-environment interactions were found. Children of immigrants had an increased risk of internalizing problems and parental unemployment was significantly associated with both internalizing and externalizing type of problems.

    Conclusion: This study shows the importance of the psychosocial environment for psychosocial health in preschool children, and adds to  the literature of null-findings of gene-by-environment effects of 5-HTTLPR and BDNF in children

    National Category
    Psychiatry
    Identifiers
    urn:nbn:se:liu:diva-124207 (URN)10.1186/s12887-016-0614-x (DOI)000377535800002 ()
    Note

    Funding agencies:Funding was obtained from the Swedish Council for Working Life and Social Research (FAS), the Swedish Research Council (VR), the Clas Groschinsky Memorial Foundation, Stockholm, Samariten Foundation, Stockholm, the Hallsten Research Foundation and ALF, County Council of Ostergotland.

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    Available from: 2016-01-22 Created: 2016-01-22 Last updated: 2017-11-30Bibliographically approved
    4. A biopsychosocial approach to risk and resilience on behavior in children followed from birth to age twelve
    Open this publication in new window or tab >>A biopsychosocial approach to risk and resilience on behavior in children followed from birth to age twelve
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    2016 (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    An increasing prevalence of mental health problems calls for more knowledge into factors associated with resilience in the context of child behavior. Biological factors are seldom considered in psychosocial models of resilience. The present study used multiple statistical methodologies to examine a biopsychosocial model of risk and resilience on behavior at preadolescence. Data from 889 children and their mothers were used. A cumulative adversity score was created by combining maternal symptoms of depression, psychosocial risk and children’s experiences of life events. The proposed resilience factors investigated were candidate genetic polymorphisms, child temperament and social functioning, and maternal sense of coherence. Results show that the l/l genotype of the serotonin transporter linked polymorphic region (5-HTTLPR) was associated with lower internalizing scores, especially for children exposed to low adversity. An easy temperament was associated with resilient outcomes for children exposed to high adversity. Child social functioning was found to be more of a general resource variable buffering risk in both high and low adversity groups. The results support a multiple level model of resilience indicating effects, though small, of both biological and psychosocial factors. The present findings call for both preventive actions and further studies on biopsychosocial models in resilience research.

    Keyword
    Child, genotype, longitudinal, mental health, resilience
    National Category
    Psychiatry
    Identifiers
    urn:nbn:se:liu:diva-124208 (URN)
    Available from: 2016-01-22 Created: 2016-01-22 Last updated: 2016-01-22Bibliographically approved
  • 14.
    Agnafors, Sara
    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.
    Svedin, Carl Göran
    Linköping University, Department of Clinical and Experimental Medicine, Barnafrid. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Local Health Care Services in Central Östergötland, Department of Child and Adolescent Psychiatry in Linköping.
    Oreland, Lars
    Uppsala University, Sweden.
    Bladh, Marie
    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.
    Comasco, Erika
    Uppsala University, Sweden.
    Sydsjö, Gunilla
    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.
    A Biopsychosocial Approach to Risk and Resilience on Behavior in Children Followed from Birth to Age 122017In: Child Psychiatry and Human Development, ISSN 0009-398X, E-ISSN 1573-3327, Vol. 48, no 4, 584-596 p.Article in journal (Refereed)
    Abstract [en]

    An increasing prevalence of mental health problems calls for more knowledge into factors associated with resilience. The present study used multiple statistical methodologies to examine a biopsychosocial model of risk and resilience on preadolescence behavior. Data from 889 children and mothers from a birth cohort were used. An adversity score was created by combining maternal symptoms of depression, psychosocial risk and childrens experiences of life events. The proposed resilience factors investigated were candidate genetic polymorphisms, child temperament, social functioning, and maternal sense of coherence. The l/ l genotype of the serotonin transporter linked polymorphic region was associated with lower internalizing scores, but not mainly related to the level of adversity. An easy temperament was associated with resilience for children exposed to high adversity. Social functioning was found to be promotive independent of the risk level. The results support a multiple-level model of resilience indicating effects, though small, of both biological and psychosocial factors.

  • 15.
    Agnafors, Sara
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences.
    Svedin, Carl Göran
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Local Health Care Services in Central Östergötland, Department of Child and Adolescent Psychiatry in Linköping.
    Oreland, Lars
    Department of Neuroscience, Uppsala University, Uppsala, Sweden.
    Bladh, Marie
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center of Paediatrics and Gynaecology and Obstetrics, Department of Gynaecology and Obstetrics in Linköping.
    Comasco, Erika
    Department of Neuroscience, Uppsala University, Uppsala, Sweden.
    Sydsjö, Gunilla
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center of Paediatrics and Gynaecology and Obstetrics, Department of Gynaecology and Obstetrics in Linköping.
    A biopsychosocial approach to risk and resilience on behavior in children followed from birth to age twelve2016Manuscript (preprint) (Other academic)
    Abstract [en]

    An increasing prevalence of mental health problems calls for more knowledge into factors associated with resilience in the context of child behavior. Biological factors are seldom considered in psychosocial models of resilience. The present study used multiple statistical methodologies to examine a biopsychosocial model of risk and resilience on behavior at preadolescence. Data from 889 children and their mothers were used. A cumulative adversity score was created by combining maternal symptoms of depression, psychosocial risk and children’s experiences of life events. The proposed resilience factors investigated were candidate genetic polymorphisms, child temperament and social functioning, and maternal sense of coherence. Results show that the l/l genotype of the serotonin transporter linked polymorphic region (5-HTTLPR) was associated with lower internalizing scores, especially for children exposed to low adversity. An easy temperament was associated with resilient outcomes for children exposed to high adversity. Child social functioning was found to be more of a general resource variable buffering risk in both high and low adversity groups. The results support a multiple level model of resilience indicating effects, though small, of both biological and psychosocial factors. The present findings call for both preventive actions and further studies on biopsychosocial models in resilience research.

  • 16.
    Ceragioli, Francesca
    et al.
    Politécnico di Torino, Dip. di Mathematica.
    Lindmark, Gustav
    Linköping University, Department of Electrical Engineering, Automatic Control. Linköping University, Faculty of Science & Engineering.
    Veibäck, Clas
    Linköping University, Department of Electrical Engineering, Automatic Control. Linköping University, Faculty of Science & Engineering.
    Wahlström, Niklas
    Linköping University, Department of Electrical Engineering, Automatic Control. Linköping University, Faculty of Science & Engineering.
    Lindfors, Martin
    Linköping University, Department of Electrical Engineering, Automatic Control. Linköping University, Faculty of Science & Engineering.
    Altafini, Claudio
    Linköping University, Department of Electrical Engineering, Automatic Control. Linköping University, Faculty of Science & Engineering.
    A bounded confidence model that preserves the signs of the opinions2016In: Proceedings of the 2016 European Control Conference, Institute of Electrical and Electronics Engineers (IEEE), 2016, 543-548 p.Conference paper (Refereed)
    Abstract [en]

    The aim of this paper is to suggest a modification to the usual bounded confidence model of opinion dynamics, so that “changes of opinion” (intended as changes of the sign of the initial state) of an agent are never induced by the dynamics. In order to do so, a bipartite consensus model is used, endowing it with a confidence range. The resulting signed bounded confidence model has a state-dependent connectivity and a behavior similar to its standard counterpart, but in addition it preserves the sign of the opinions by “repelling away” opinions localized near the origin but on different sides with respect to 0.

  • 17.
    Rustichini, Aldo
    et al.
    University of Minnesota.
    Dickhaut, John
    University of Minnesota.
    Ghirardato, Paolo
    Università di Torino.
    Smith, Christian Skinner
    Kansas State University.
    Pardo, José V.
    University of Minnesota.
    A Brain Imaging Study of the Choice Procedure2005In: Games and Economic Behavior, ISSN 0899-8256, E-ISSN 1090-2473, Vol. 52, no 2, 257-282 p.Article in journal (Refereed)
    Abstract [en]

    We study the behavior of subjects facing choices between certain, risky, and ambiguous lotteries. Subjects' choices are consistent with the economic theories modeling ambiguity aversion. Our results support the conjecture that subjects face choice tasks as an estimation of the value of the lotteries, and that the difficulty of the choice is an important explanatory variable (in addition to risk and ambiguity aversion).

    The brain imaging data suggest that such estimation is of an approximate nature when the choices involve ambiguous and risky lotteries, as the regions in the brain that are activated are typically located in parietal lobes. Thus such choices require mental faculties that are shared by all mammals, and in particular are independent of language. In contrast, choices involving partial ambiguous lotteries additionally produce an activation of the frontal region, which indicates a different, more sophisticated cognitive process.

  • 18. Deak, P
    et al.
    Gali, Adam
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology.
    Hajnal, Z
    Frauenheim, T
    Nguyen, Tien Son
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, The Institute of Technology.
    Janzén, Erik
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials.
    Choyke, WJ
    Ordejon, P
    A cause for SiC/SiO2 interface states: The site selection of oxygen in SiC2003In: Materials Science Forum, Vols. 433-436, 2003, Vol. 433-4, 535-538 p.Conference paper (Refereed)
    Abstract [en]

    We show that in the SiC/SiO2 system the interface states in the lower half of the gap are the consequence of the behavior of oxygen in SiC. Investigating the elemental steps of oxidation on a simple model by means of ab initio density functional calculations we find that, in course of the oxidation, carbon-vacancy (V-C) - oxygen complexes constantly arise. The V-C+O complexes have donor states around E-V+0.8 eV. Their presence gives rise to a thin transition layer which is not SiO2 but an oxygen contaminated Si-rich interface layer producing the aforementioned gap states.

  • 19.
    Ulfendahl, Mats
    et al.
    Karolinska Institutet and Karolinska University Hospital, Stockholm, Sweden.
    Hu, Zhengqing
    Karolinska Institutet and Karolinska University Hospital, Stockholm, Sweden.
    Olivius, Petri
    Karolinska Institutet and Karolinska University Hospital, Stockholm, Sweden.
    Duan, Maoli
    Karolinska Institutet and Karolinska University Hospital, Stockholm, Sweden.
    Wei, Dongguang
    Karolinska Institutet and Karolinska University Hospital, Stockholm, Sweden.
    A cell therapy approach to substitute neural elements in the inner ear2007In: Physiology and Behavior, ISSN 0031-9384, E-ISSN 1873-507X, Vol. 92, no 1-2, 75-79 p.Article in journal (Refereed)
    Abstract [en]

    Three different donor tissues were tested for their capacity to survive, integrate and differentiate in the adult inner ear. Surviving embryonic dorsal root ganglion cells were found within the spiral ganglion neuron region and along the auditory nerve fibers. In the presence of exogenous nerve growth factor (NGF), the dorsal root ganglion cells formed extensive growth of neurites that seemed to contact the host neurons. Adult neural stem cells survived relative poorly in the inner car whereas embryonic stem cells showed a somewhat greater capacity for survival and integration. Overall, the survival rate of implanted tissue was quite low in the cochlea. It is concluded that an inner ear cell therapy approach based on the implantation of exogenous cells will require that important survival factors are identified and supplied. In addition, it is possible that the physical properties of the cochlea, e.g., fluid-filled compartments and very limited space for cell proliferation, are unfavorable, at least in the normal cochlea.

  • 20.
    Johansson, Anja
    et al.
    Linköping University, Department of Science and Technology, Media and Information Technology. Linköping University, The Institute of Technology.
    Dell’Acqua, Pierangelo
    Linköping University, Department of Science and Technology, Media and Information Technology. Linköping University, The Institute of Technology.
    A Comparison Between Emotional Behavior Networks and Behavior Trees for Virtual CharactersManuscript (preprint) (Other academic)
    Abstract [en]

    Behavior trees have become increasingly popular as an action selection mechanism for non-player characters in games. A different approach to the action selection problem is represented by emotional behavior networks. They are a dynamic, goal-driven decision-making model, which focuses on using emotions for decision making, incorporating various psychological theories concerning emotions. In this paper, we compare behavior trees to emotional behavior networks from a design and functionality point of view.

  • 21.
    Zetterqvist, Maria
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Child and Adolescent Psychiatry. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Local Health Care Services in Central Östergötland, Department of Child and Adolescent Psychiatry in Linköping.
    Lundh, Lars-Gunnar
    Lund University, Sweden .
    Svedin, Carl Göran
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Health Sciences.
    A Comparison of Adolescents Engaging in Self-Injurious Behaviors With and Without Suicidal Intent: Self-Reported Experiences of Adverse Life Events and Trauma Symptoms2013In: Journal of Youth and Adolescence, ISSN 0047-2891, E-ISSN 1573-6601, Vol. 42, no 8, 1257-1272 p.Article in journal (Refereed)
    Abstract [en]

    Research comparing adolescents engaging in suicidal and non-suicidal self-injury (NSSI), both separately and in combination, is still at an early stage. The purpose of the present study was to examine overlapping and distinguishable features in groups with different types of self-injurious behaviors, using a large community sample of 2,964 (50.6 % female) Swedish adolescents aged 15-17 years. Adolescents were grouped into six categories based on self-reported lifetime prevalence of self-injurious behaviors. Of the total sample, 1,651 (55.7 %) adolescents reported no self-injurious behavior, 630 (21.2 %) reported NSSI 1-4 times, 177 (6.0 %) reported NSSI 5-10 times, 311 (10.5 %) reported NSSI a parts per thousand yen 11 times, 26 (0.9 %) reported lifetime prevalence of suicide attempt and 169 (5.7 %) adolescents reported both NSSI and suicide attempt. After controlling for gender, parental occupation and living conditions, there were significant differences between groups. Pairwise comparisons showed that adolescents with both NSSI and suicide attempt reported significantly more adverse life events and trauma symptoms than adolescents with only NSSI, regardless of NSSI frequency. The largest differences (effect sizes) were found for interpersonal negative events and for symptoms of depression and posttraumatic stress. Adolescents with frequent NSSI reported more adversities and trauma symptoms than those with less frequent NSSI. There were also significant differences between all the NSSI groups and adolescents without any self-injurious behavior. These findings draw attention to the importance of considering the cumulative exposure of different types of adversities and trauma symptoms when describing self-injurious behaviors, with and without suicidal intent.

  • 22.
    Albert, Frank W.
    et al.
    Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany, and Lewis Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey, United States of America,.
    Somel, Mehmet
    Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany, CAS–MPG Partner Institute for Computational Biology SIBS, Shanghai, China.
    Carneiro, Miguel
    CIBIO, Centro de Investigac¸a˜o em Biodiversidade e Recursos Gene´ ticos, Vaira˜o, Portugal, and Departamento de Zoologia e Antropologia–Faculdade de Cieˆncias da Universidade do Porto, Porto, Po.
    Aximu-Petri, Ayinuer
    Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany.
    Halbwax, Michael
    Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany and Fernan Vaz Gorilla Project, Port-Gentil, Gabon.
    Thalmann, Olaf
    Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany and Department of Biology, University of Turku, Turku, Finland.
    Blanco-Aguiar, Jose A.
    CIBIO, Centro de Investigac¸a˜o em Biodiversidade e Recursos Gene´ ticos, Vaira˜o, Portugal, 5 Departamento de Zoologia e Antropologia–Faculdade de Cieˆncias da Universidade do Porto, Porto, Portugal and Instituto de Investigacio´n en Recursos Cinege´ticos, IREC (CSIC, UCLM, JCCM), Ciudad Real, Spain.
    Plyusnina, Irina Z.
    Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia.
    Trut, Lyudmila
    Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia.
    Villafuerte, Rafael
    Instituto de Investigacio´n en Recursos Cinege´ticos, IREC (CSIC, UCLM, JCCM), Ciudad Real, Spain.
    Ferrand, Nuno
    CIBIO, Centro de Investigac¸a˜o em Biodiversidade e Recursos Gene´ ticos, Vaira˜o, Portugal, and Departamento de Zoologia e Antropologia–Faculdade de Cieˆncias da Universidade do Porto, Porto, Portugal.
    Kaiser, Sylvia
    Department of Behavioural Biology, University of Mu¨ nster, Mu¨ nster, Germany.
    Jensen, Per
    Linköping University, Department of Physics, Chemistry and Biology, Zoology. Linköping University, The Institute of Technology.
    Pääbo, Svante
    Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany.
    A Comparison of Brain Gene Expression Levels in Domesticated and Wild Animals2012In: PLOS Genetics, ISSN 1553-7390, Vol. 8, no 9, e1002962- p.Article in journal (Refereed)
    Abstract [en]

    Domestication has led to similar changes in morphology and behavior in several animal species, raising the questionwhether similarities between different domestication events also exist at the molecular level. We used mRNA sequencing toanalyze genome-wide gene expression patterns in brain frontal cortex in three pairs of domesticated and wild species (dogsand wolves, pigs and wild boars, and domesticated and wild rabbits). We compared the expression differences with thosebetween domesticated guinea pigs and a distant wild relative (Cavia aperea) as well as between two lines of rats selectedfor tameness or aggression towards humans. There were few gene expression differences between domesticated and wilddogs, pigs, and rabbits (30–75 genes (less than 1%) of expressed genes were differentially expressed), while guinea pigs andC. aperea differed more strongly. Almost no overlap was found between the genes with differential expression in thedifferent domestication events. In addition, joint analyses of all domesticated and wild samples provided only suggestiveevidence for the existence of a small group of genes that changed their expression in a similar fashion in differentdomesticated species. The most extreme of these shared expression changes include up-regulation in domesticates of SOX6and PROM1, two modulators of brain development. There was almost no overlap between gene expression in domesticatedanimals and the tame and aggressive rats. However, two of the genes with the strongest expression differences betweenthe rats (DLL3 and DHDH) were located in a genomic region associated with tameness and aggression, suggesting a role ininfluencing tameness. In summary, the majority of brain gene expression changes in domesticated animals are specific tothe given domestication event, suggesting that the causative variants of behavioral domestication traits may likewise bedifferent.

  • 23.
    Falkmer, Torbjörn
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Neuroscience and Locomotion, Rehabilitation Medicine. Östergötlands Läns Landsting, Local Health Care Services in Central Östergötland, Paediatric Habilitation Community Service.
    Gregersen, Nils-Petter
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Department of Health and Society, Division of Preventive and Social Medicine and Public Health Science.
    A comparison of eye movement behavior of inexperienced and experienced drivers in real traffic environments2005In: Optometry and Vision Science, ISSN 1040-5488, E-ISSN 1538-9235, Vol. 82, no 8, 732-739 p.Article in journal (Refereed)
    Abstract [en]

    Purpose. The importance of the visual system as the input channel for sensory information necessary when driving is often stated. There are several reports on differences in visual search strategies between experienced and inexperienced drivers, as well as in relation to the roadway. However, the results are ambiguous and are not sampled by similar procedures. Based on previous findings, the aim of the present study was to gain further knowledge on these differences by testing the hypotheses that inexperienced drivers, in comparison to experienced drivers, fixate closer to the vehicle, fixate more often on in-vehicle objects, spread their fixations less along the horizontal meridian, fixate more often on relevant traffic cues, and fixate more often on objects classified as potential hazards. Methods. Data from eye-tracker recordings of visual search strategies of the driver in real-world traffic were used for the analyses. Results. The results confirmed all stated hypotheses regarding differences between inexperienced and experienced drivers, with the exception of fixations closer to the vehicle, in which ambiguous results were found. Conclusions. The present study provides normative data for the understanding of the development of visual search strategies among drivers. The methodology used in the present study, i.e., to combine a quantitative analysis with a qualitative analysis proved, to be useful to compare visual search strategies among inexperienced and experienced drivers. Copyright © 2005 American Academy of Optometry.

  • 24.
    Lagerqvist, Victor
    Linköping University, Department of Computer and Information Science, TCSLAB - Theoretical Computer Science Laboratory.
    A comparison of SL- and unit-resolution search rules for stratified logic programs2010Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    There are two symmetrical resolution rules applicable to logic programs - SL-resolution which yields a top-down refutation and unit-resolution which yields a bottom-up refutation. Both resolution principles need to be coupled with a search rule before they can be used in practice. The search rule determines in which order program clauses are used in the refutation and affects both performance, completeness and quality of solutions. The thesis surveys exhaustive and heuristic search rules for SL-resolution and transformation techniques for (general) logic programs that makes unit-resolution goal oriented.

    The search rules were implemented as meta-interpreters for Prolog and were benchmarked on a suite of programs incorporating both deterministic and nondeterministic code. Whenever deemed applicable benchmark programs were permuted with respect to clause and goal ordering to see if it affected the interpreters performance and termination.

    With the help of the evaluation the conclusion was that alternative search rules for SL-resolution should not be used for performance gains but can in some cases greatly improve the quality of solutions, e.g. in planning or other applications where the quality of an answer correlates with the length of the refutation. It was also established that A* is more flexible than exhaustive search rules since its behavior can be fine-tuned with weighting, and can in some cases be more efficient than both iterative deepening and breadth-first search. The bottom-up interpreter based on unit-resolution and magic transformation had several advantages over the top-down interpreters. Notably for programs where subgoals are recomputed many times. The great disparity in implementation techniques made direct performance comparisons hard however, and it is not clear if even an optimized bottom-up interpreter is competitive against a top-down interpreter with tabling of answers.

  • 25.
    Edlund, Ulf
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Engineering Mechanics.
    Volgers, Pieter
    A composite ply failure model based on continuum damage mechanics2004In: Composite structures, ISSN 0263-8223, E-ISSN 1879-1085, Vol. 65, no 3-4, 347-355 p.Article in journal (Refereed)
    Abstract [en]

    A material model including the failure behaviour is derived for a thin unidirectional (UD) composite ply. The model is derived within a thermodynamic framework and the failure behaviour is modelled using continuum damage mechanics. The following features describe the model: (i) The ply is assumed to be in a plane state of stress. (ii) Three damage variables associated with the stress in the fibre-, transverse and shear directions, respectively, are used. (iii) The plastic behaviour of the matrix material is modelled. (iv) The difference in the material response in tensile and compressive loading is modelled. (v) Rate dependent behavior of plasticity and damage (i.e. strength) is modelled.

  • 26.
    Yasar, Ansar-Ul-Haque
    et al.
    Linköping University, Department of Computer and Information Science.
    Jameel, Adeel
    Linköping University, Department of Computer and Information Science.
    A Computational Analysis of Driving Variations in a Distributed Simulated Driving Environment2007Independent thesis Basic level (professional degree), 20 points / 30 hpStudent thesis
    Abstract [en]

    This Master thesis report is the research conducted at the Linköping University (LiU) in the Cognitive Engineering group. This report describes and discusses the possible driving variations at T-intersections. In this study we tested how voice based command (GPS) system and traffic lights did influence the driving behavior. This computational study was conducted on a multi user driving simulation environment at Linköping University. A total of 12 groups each consisting of 4 persons participated in this study. The participants also completed a survey on paper with their valuable comments. To study the driving behavior we analyzed the conflict indicators at the Tintersection. We selected Post Encroachment Time (PET), speed and acceleration as good conflict indicators.

  • 27.
    Durbeej, Bo
    Linköping University, Department of Physics, Chemistry and Biology, Computational Physics. Linköping University, The Institute of Technology.
    A computational perspective on the photochemistry of photosensory proteins: phytochromes and Anabaena sensory rhodopsin2012In: Quantum Simulations of Materials and Biological Systems / [ed] Jun Zeng, Rui-Qin Zhang and Herbert R. Treutlein, Springer Netherlands, 2012, 169-194 p.Chapter in book (Refereed)
    Abstract [en]

    The merits of quantum simulations in photobiology are illustrated by presenting recent computational studies investigating the basic photochemistry of phytochromes, a ubiquitous family of photosensory proteins, and Anabaena sensory rhodopsin, a recently discovered member of the rhodopsins. Focusing on the chromophore photoisomerization reactions that trigger these proteins’ responses to light and using density functional methods and multiconfigurational ab initio methods in combination with molecular mechanics, three surprising results can be singled out. First, it is found that the photochemical reactivity of the bilin chromophores of phytochromes is fundamentally different in solution and in the protein, with different photoisomerization channels being preferred. Second, it is found that the two retinal photoisomerizations that govern the interconversion of Anabaena sensory rhodopsin between its two major forms proceed in such a way that the chromophore completes a full 360° rotation during one photocycle. This means that this protein is a biological realization of a light-driven molecular rotor. Third, and finally, it is demonstrated that the stereochemical origin of this remarkable behavior is actually a key element for the function of a class of synthetic light-driven molecular rotors developed from overcrowded alkenes, thereby identifying Anabaena sensory rhodopsin as a possible source of inspiration for the future design and construction of such molecular machines.

  • 28.
    Mishra, Rajesh
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biochemistry.
    Olofsson, Linus
    Karlsson, Martin
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biochemistry.
    Carlsson, Uno
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biochemistry.
    Nicholls, Ian A.
    Hammarström, Per
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biochemistry.
    A conformationally isoformic thermophilic protein with high kinetic unfolding barriers2008In: Cellular and Molecular Life Sciences (CMLS), ISSN 1420-682X, E-ISSN 1420-9071, Vol. 65, no 5, 827-839 p.Article in journal (Refereed)
    Abstract [en]

    The basis for the stability of thermophilic proteins is of fundamental interest for extremophile biology. We investigated the folding and unfolding processes of the homotetrameric Thermoanaerobacter brockii alcohol dehydrogenase (TBADH). TBADH subunits were 4.8 kcal/mol less stable towards guanidinium chloride (GdmCl) unfolding compared to urea, indicating ionic modulation of TBADH stability. Strongly denaturing conditions promoted mono-exponential unfolding kinetics with linear dependence on denaturant concentration. Here TBADH unfolded >40-fold slower when extrapolated from urea as compared to GdmCl unfolding. A marked unfolding hysteresis was shown when comparing refolding and unfolding in urea. An unusual biphasic unfolding trajectory with an exceptionally slow phase at intermediate concentrations of GdmCl and urea was also observed. We advocate that TBADH forms two distinctly different tetrameric isoforms, and likely an ensemble of native states. This unusual supramolecular folding behavior has been shown responsible for formation of amyloidotic yeast prion strains and can have functional importance for TBADH. © 2008 Birkhaueser.

  • 29.
    Sharifimajd, Babak
    et al.
    Linköping University, Department of Management and Engineering, Mechanics. Linköping University, The Institute of Technology.
    Stålhand, Jonas
    Linköping University, Department of Management and Engineering, Mechanics. Linköping University, The Institute of Technology.
    A continuum model for excitation–contraction of smooth muscle under finite deformations2014In: Journal of Theoretical Biology, ISSN 0022-5193, E-ISSN 1095-8541, Vol. 355, 1-9 p.Article in journal (Refereed)
    Abstract [en]

    The main focus in most of continuum based muscle models is the muscle contraction dynamics while other physiological processes governing muscle contraction, e.g., the cell membrane excitation and the activation, are ignored. These latter processes are essential to initiate contraction and to determine the amount of generated force, and by excluding them, the developed model cannot replicate the true behavior of the muscle in question. The aim of this study is to establish a thermodynamically and physiologically consistent framework which allows to model smooth muscle contraction by including cell membrane excitability and kinetics of myosin phosphorylation, along with dynamics of smooth muscle contraction. The model accounts for these processes through a set of coupled dissipative constitutive equations derived by applying the first principles. To show the performance of the derived model, it is evaluated for two different cases: a mechanochemical study of pig taenia coli cells where the excitation process is excluded, and a complete excitation–contraction process of rat myometrium. The results show that the model is able to replicate important aspects of the smooth muscle EC process acceptably.

  • 30.
    Sharifimajd, Babak
    et al.
    Linköping University, Department of Management and Engineering, Mechanics. Linköping University, The Institute of Technology.
    Stålhand, Jonas
    Linköping University, Department of Management and Engineering, Mechanics. Linköping University, The Institute of Technology.
    A continuum model for skeletal muscle contraction at homogeneous finite deformations2013In: Biomechanics and Modeling in Mechanobiology, ISSN 1617-7959, E-ISSN 1617-7940, Vol. 12, no 5, 965-973 p.Article in journal (Refereed)
    Abstract [en]

    The contractile force in skeletal muscle models is commonly postulated to be the isometric force multiplied by a set of experimentally motivated functions which account for the muscle’s active properties. Although both flexible and simple, this approach does not automatically guarantee a thermodynamically consistent behavior. In contrast, the continuum mechanical model proposed herein is derived from fundamental principles in mechanics and guarantees a dissipative behavior. Further, the contractile force is associated with a friction clutch which provides a simple and well-defined macroscopic model for cycling cross-bridges. To show the performance of the model, it is specialized to standard experiments for rabbit tibialis anterior muscle. The results show that the model is able to capture important characteristics of skeletal muscle.

  • 31.
    Arkad, Jenny
    et al.
    Linköping University, Department of Electrical Engineering, Automatic Control.
    Andersson, Tomas
    Linköping University, Department of Electrical Engineering, Automatic Control.
    A Control Algorithm for an Ultrasonic Motor2011Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This report is the result of a master thesis work where the goal was to develop acontrol system for a type of ultrasonic motor. The ultrasonic motors use ultrasonicvibrations from a piezoelectric material to produce a rotating motion. They arepowered by two sinusoidal voltages and their control signals generally are thevoltages amplitude, frequency and the phase difference between the two voltages.In this work the focus is on control using only amplitude and frequency. A feedbacksignal was provided by an encoder, giving an angular position. The behavior of themotors were investigated for various sets of control signals. From collected data alinearized static model was derived for the motor speed. This derived model wasused to create a two part control system, with an inner control loop to managethe speed of the motors using a PI controller and an outer control loop to managethe position of the motors. A simple algorithm was used for the position controland the result was a control system able to position the motors with a 0.1 degreeaccuracy. The motors show potential for greater accuracy with a position feedback,but the result in this work is limited by the encoder used in the experiments.

  • 32.
    Andersson, Gerhard
    et al.
    Linköping University, Faculty of Arts and Sciences. Linköping University, Department of Behavioural Sciences, Clinical and Social Psychology.
    Asmundson, Gordon J
    Denev, Johanna
    Nilsson, Johanna
    Hans-Christian, Larsen
    A controlled trial of cognitive-behavior therapy combined with vestibular rehabilitation in the treatment of dizziness2006In: Behaviour Research and Therapy, ISSN 0005-7967, E-ISSN 1873-622X, Vol. 44, no 9, 1265-1273 p.Article in journal (Refereed)
    Abstract [en]

    Dizziness is a common and often untreated symptom in the general population. The aim of this study was to investigate the effects of a combined cognitive-behavioral/vestibular rehabilitation (VR) program, using a randomized control design. A total of 29 participants were randomized to treatment consisting of psychoeducation, vestibular exercises, relaxation and cognitive interventions, or to serve as waiting list controls. Measures of dizziness-related handicap, dizziness-provoking movements, and daily diary registrations of dizziness symptoms at pre- and post-treatment showed statistically significant improvements in many domains, which translated to moderate effect sizes. These findings provide preliminary support for the combination of Cognitive-behavioral therapy (CBT) and VR methods in the treatment of dizziness. © 2005 Elsevier Ltd. All rights reserved.

  • 33.
    Haglund, Lena
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Social and Welfare Studies, Health, Activity, Care.
    Kjellberg, Anette
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Social and Welfare Studies, Health, Activity, Care.
    A critical analysis of the Model of Human Occupation.1999In: Canadian Journal of Occupational Therapy / Revue Canadienne d`Ergotèrapie, ISSN 0008-4174, no 2, 102-1089 p.Article in journal (Refereed)
    Abstract [en]

    Examination of the applicability of the Model of Human Occupation in Swedish occupational therapy concludes that the environment is a central factor in understanding occupational behavior, but the model does not accurately or adequately depict the relationship between individuals and the environment. Volition is also an important factor in occupational-therapy intervention

  • 34.
    Svärd, Carl
    et al.
    Linköping University, Department of Electrical Engineering, Vehicular Systems. Linköping University, The Institute of Technology.
    Nyberg, Mattias
    Linköping University, Department of Electrical Engineering, Vehicular Systems. Linköping University, The Institute of Technology.
    Frisk, Erik
    Linköping University, Department of Electrical Engineering, Vehicular Systems. Linköping University, The Institute of Technology.
    Krysander, Mattias
    Linköping University, Department of Electrical Engineering, Vehicular Systems. Linköping University, The Institute of Technology.
    A Data-Driven and Probabilistic Approach to Residual Evaluation for Fault Diagnosis2011In: 50th IEEE Conference on Decision and Control and European Control Conference (CDC-ECC), 2011, Institute of Electrical and Electronics Engineers (IEEE), 2011, 95-102 p.Conference paper (Refereed)
    Abstract [en]

    An important step in fault detection and isolation is residual evaluation where residuals, signals ideally zero in the no-fault case, are evaluated with the aim to detect changes in their behavior caused by faults. Generally, residuals deviate from zero even in the no-fault case and their probability distributions exhibit non-stationary features due to, e.g., modeling errors, measurement noise, and different operating conditions. To handle these issues, this paper proposes a data-driven approach to residual evaluation based on an explicit comparison of the residual distribution estimated on-line and a no-fault distribution, estimated off-line using training data. The comparison is done within the framework of statistical hypothesis testing. With the Generalized Likelihood Ratio test statistic as starting point, a more powerful and computational efficient test statistic is derived by a properly chosen approximation to one of the emerging likelihood maximization problems. The proposed approach is evaluated with measurement data on a residual for diagnosis of the gas-flow system of a Scania truck diesel engine. The proposed test statistic performs well, small faults can for example be reliable detected in cases where regular methods based on constant thresholding fail.

  • 35.
    Carvalho Bittencourt, André
    et al.
    Linköping University, Department of Electrical Engineering, Automatic Control. Linköping University, The Institute of Technology.
    Saarinen, Kari
    ABB Corporate Research.
    Sander Tavallaey, Shiva
    ABB Corporate Research.
    Gunnarsson, Svante
    Linköping University, Department of Electrical Engineering, Automatic Control. Linköping University, The Institute of Technology.
    A Data-Driven Method for Monitoring of Repetitive Systems: Applications to Robust Wear Monitoring of a Robot Joint2013Report (Other academic)
    Abstract [en]

    This paper presents a method for monitoring of systems that operate in a repetitive manner. Considering that data batches collected from a repetitive operation will be similar unless in the presence of an abnormality, a condition change is inferred by comparing the monitored data against a nominal batch. The method proposed considers the comparison of data in the distribution domain, which reveals information of the data amplitude. This is achieved with the use of kernel density estimates and the Kullback-Leibler distance. To decrease sensitivity to unknown disturbances while increasing sensitivity to faults, the use of a weighting vector is suggested which is chosen based on a labeled dataset. The framework is simple to implement and can be used without process interruption, in a batch manner. The method was developed with interests in industrial robotics where a repetitive behavior is commonly found. The problem of wear monitoring in a robot joint is studied based on data collected from a test-cycle. Real data from accelerated wear tests and simulations are considered. Promising results are achieved where the method output shows a clear response to the wear increases.

  • 36.
    Winters, Michael
    et al.
    Department of Microtechnology and Nanoscience (Chalmers) Göteborg, Sweden.
    Thorsell, Mattias
    Department of Microtechnology and Nanoscience (Chalmers) Göteborg, Sweden.
    ul Hassan, Jawad
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, The Institute of Technology.
    Rorsman, N
    Department of Microtechnology and Nanoscience (Chalmers) Göteborg, Sweden.
    Janzén, Erik
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, The Institute of Technology.
    Zirath, H
    Department of Microtechnology and Nanoscience (Chalmers) Göteborg, Sweden.
    A DC Comparison Study Between H-Intercalated and Native epigrapheneson SiC substrates2013In: Materials Science Forum (Volumes 740 - 742), Trans Tech Publications Inc., 2013, 129-132 p.Conference paper (Refereed)
    Abstract [en]

    The aim of this study is to compare DC characteristics of ‘as-grown’ and hydrogen (H)-intercalated epitaxial graphenes on SiC substrates [1,2]. Epitaxial graphene is grown on SiC at1400-1600C, and H-intercalation is performed via in-situ introduction of Hydrogen during thegraphitization process [5]. The fabrication processing steps used to define test structures areidentical for the two materials. Results on the DC behavior and uniformity issues with respect toboth materials are reported. The as-grown material behaves as a linear resistance, while Hintercalateddemonstrates a non-linear characteristic. Hysteresis effects and time dependentbehaviors are also observed in both materials. Extensive Hall measurements are performed on bothmaterials with the aim of providing a qualitative understanding of material uniformity in both epigraphenes.

  • 37.
    Gällström, Andreas
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, The Institute of Technology.
    Magnusson, Björn
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, The Institute of Technology.
    Ellison, A.
    Gali, Adam
    Wigner Research Center for Physics, Hungarian Academy of Sciences / Department of Atomic Physics, Budapest University of Technology and Economics, Hungary.
    Ivanov, Ivan G.
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, The Institute of Technology.
    Janzén, Erik
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, The Institute of Technology.
    A defect center for quantum computing: Mo in SiCManuscript (preprint) (Other academic)
    Abstract [en]

    The electronic structure and vibrational properties of molybdenum (Mo) in SiC are analyzed and investigated in detail. Mo is considered as occupying the silicon-carbon divacancy in the so-called asymmetric split vacancy (ASV) configuration. Group-theoretical considerations within this model are used to explain the experimental results (optical properties and behavior in magnetic field). The vibrational properties of the defect are studied using simple the “defect molecule” model with parameters determined phenomenologically from the experimental data. The position of Mo in the ASV configuration deduced from this model is shown to be in good agreement with the earlier reported data from ab initio supercell calculations. The usefulness of molybdenum in SiC in quantum computing is investigated, and it shown that Mo is a highly promising candidate for quantum computing.

  • 38.
    Fahleson, Tobias
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Computational Physics. Linköping University, The Institute of Technology.
    Norman, Patrick
    Linköping University, Department of Physics, Chemistry and Biology, Computational Physics. Linköping University, The Institute of Technology.
    Coriani, Sonia
    University of Trieste, Italy .
    Rizzo, Antonio
    UOS Pisa, Italy .
    Rikken, Geert L J A
    CNRS INSA UJF UPS, France .
    A density functional theory study of magneto-electric Jones birefringence of noble gases, furan homologues, and mono-substituted benzenes2013In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 139, no 19, 194311- p.Article in journal (Refereed)
    Abstract [en]

    We report on the results of a systematic ab initio study of the Jones birefringence of noble gases, of furan homologues, and of monosubstituted benzenes, in the gas phase, with the aim of analyzing the behavior and the trends within a list of systems of varying size and complexity, and of identifying candidates for a combined experimental/theoretical study of the effect. We resort here to analytic linear and nonlinear response functions in the framework of time-dependent density functional theory. A correlation is made between the observable (the Jones constant) and the atomic radius for noble gases, or the permanent electric dipole and a structure/chemical reactivity descriptor as the para Hammett constant for substituted benzenes.

  • 39.
    Engelson, Vadim
    et al.
    Linköping University, Department of Computer and Information Science.
    Larsson, Håkan
    Linköping University, Department of Computer and Information Science.
    Fritzson, Peter
    Linköping University, Department of Computer and Information Science.
    A design, simulation and visualization environment for object-oriented mechanical and multi-domain models in Modelica1999In: 1999 IEEE International Conference on Information Visualization, Proceedings / [ed] E. Banissi, F. Khosrowshahi, M. Sarfraz, E. Tatham, A. Ursyn, 1999, 188-193 p.Conference paper (Refereed)
    Abstract [en]

    The complexity of mechanical and multi-domain simulation models is rapidly increasing. Therefore new methods and standards are needed for model design. A new language, Modelica, has been proposed by an international design committee as a standard, object oriented, equation based language suitable for description of the dynamics of systems containing mechanical, electrical, chemical and other types of components. However, it is complicated to describe the system models in textual form, whereas CAD systems are convenient tools for this purpose. We have designed an environment that supports the translation from CAD models to standard Modelica notation. This notation is then used for simulation and visualization. Assembly information is extracted from the CAD models, from which a Modelica model is generated. By solving equations expressed in Modelica, the system is simulated. A 3D visualization tool based on OpenGL visualizes expected and actual model behavior, as well as additional parameters. The environment has been applied for robot and flight simulation

  • 40.
    Asghar, Malik Summair
    Linköping University, Department of Electrical Engineering. Linköping University, The Institute of Technology.
    A “Divide-by-Odd Number” Injection-Locked Frequency Divider.2013Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The use of resonant CMOS frequency dividers with direct injection in frequencysynthesizers has increased in recent years due to their lower power consumptioncompared to conventional digital prescalers. The theoretical and experimentalaspects of these dividers have received great attention. This masters thesis workis a continuation of earlier work, based on the fundamentals of Injection-LockedFrequency Dividers (ILFD’s). The LC CMOS ILFD with direct injection is wellknownfor its divide-by-2 capability. However, it does not divide well by oddnumbers. The goal of this master thesis work is to modify the LC CMOS ILFDwith direct injection so that it can divide equally well by odd and even integers.In this master thesis report, an introduction to the basic concepts behindInjection-Locked frequency dividers is first presented. Some of the previous workand the background of a reference LC CMOS ILFD design are studied. The author,studied the reference design, and the experimental setup used for characterizingit’s locking behavior. The algorithm used to characterize the locking behavior ofthis ILFD are explored to reproduce the results for divide-by-even numbers for theexisting ILFD topology. Using a Spice model these results are also reproduced insimulations.Over the years, numerous ILFD circuit topologies have been proposed, most ofwhich have been optimized for division by even numbers, especially divide-by-2.It has been more difficult to realize division by odd numbers, such as divide-by-3.This master thesis work develops a simple modification to an LC CMOS injectionlocked frequency divider (ILFD) with direct injection, which gives it a wide lockingrange both in the “divide-by-odd number” mode and in the conventional “divideby-even number” regime, thereby opening up applications which require frequencydivision by an odd number. The work presents the circuit architecture, SPICEsimulations and experimental validation.

  • 41.
    Landelius, Tomas
    et al.
    n/a.
    Knutsson, Hans
    Linköping University, Department of Electrical Engineering, Computer Vision. Linköping University, The Institute of Technology.
    A Dynamic Tree Structure for Incremental Reinforcement Learning of Good Behavior1994Report (Other academic)
    Abstract [en]

    This paper addresses the idea of learning by reinforcement, within the theory of behaviorism. The reason for this choice is its generality and especially that the reinforcement learning paradigm allows systems to be designed, which can improve their behavior beyond that of their teacher. The role of the teacher is to define the reinforcement function, which acts as a description of the problem the machine is to solve. Gained knowledge is represented by a behavior probability density function which is approximated with a number of normal distributions, stored in the nodes of a binary tree. It is argued that a meaningful partitioning into local models can only be accomplished in a fused space consisting of both stimuli and responses. Given a stimulus, the system searches for responses likely to result in highly reinforced decisions by treating the sum of the two normal distributions on each level in the tree as a distribution describing the system's behavior at that resolution. The resolution of the response, as well as the tree growing and pruning processes, are controlled by a random variable based on the difference in performance between two consecutive levels in the tree. This results in a system that will never be content but will indefinitely continue to search for better solutions.

  • 42.
    Ghaeini, Bentolhoda
    Linköping University, Department of Computer and Information Science. Linköping University, The Institute of Technology.
    A Fault-Aware Resource Manager for Multi-Processor System-on-Chip2013Independent thesis Advanced level (degree of Master (Two Years)), 80 credits / 120 HE creditsStudent thesis
    Abstract [en]

    The semiconductor technology development empowers fabrication of extremelycomplex integrated circuits (ICs) that may contain billions of transistors. Suchhigh integration density enables designing an entire system onto a single chip,commonly referred to as a System-on-Chip (SoC). In order to boost performance,it is increasingly common to design SoCs that contain a number of processors, socalled multi-processor system-on-chips (MPSoCs).While on one hand, recent semiconductor technologies enable fabrication ofdevices such as MPSoCs which provide high performance, on the other hand thereis a drawback that these devices are becoming increasingly susceptible to faults.These faults may occur due to escapes from manufacturing test, aging effects orenvironmental impacts. When present in a system, faults may disrupt functionalityand can cause incorrect system operation. Therefore, it is very importantwhen designing systems to consider methods to tolerate potential faults. To copewith faults, there is a need of fault handling which implies automatic detection,identification and recovery from faults which may occur during the system’s operation.This work is about the design and implementation of a fault handling methodsfor an MPSoC. A fault aware Resource Manager (RM) is designed and implementedto obtain correct system operation and maximize the system’s throughputin the presence of faults. The RM has the responsibility of scheduling jobs to availableresources, collecting fault states from resources in the system and performingfault handling tasks, based on fault states. The RM is also employed in multipleexperiments in order to study its behavior in different situations.

  • 43.
    Schmidt, Peter
    et al.
    Linköping University, Department of Management and Engineering, Mechanics. Linköping University, The Institute of Technology.
    Edlund, Ulf
    Linköping University, Department of Management and Engineering, Mechanics. Linköping University, The Institute of Technology.
    A finite element method for failure analysis of adhesively bonded structures2010In: International Journal of Adhesion and Adhesives, ISSN 0143-7496, Vol. 30, no 8, 665-681 p.Article in journal (Refereed)
    Abstract [en]

    The solid bodies constituting the adhesively bonded joint, i.e. the adhesive and the adherends, are treated as material surfaces. The result can be regarded as a structural element model of the compound joint. The adhesive is modelled as a softening material due to local material damage. As a consequence, the propagation of a crack front in the adhesive layer can be followed, and the failure load of the structure becomes a computational result. A one-parameter viscous regularization of the softening adhesive material law is used in order to improve the numerical behavior. Several applications are presented

  • 44.
    Busse, Christian
    et al.
    Linköping University, Department of Management and Engineering, Solid Mechanics. Linköping University, Faculty of Science & Engineering.
    Loureiro Homs, Jordi
    Siemens Ind Turbomachinery AB, Sweden.
    Gustafsson, David
    Siemens Ind Turbomachinery AB, Sweden.
    Palmert, Frans
    Siemens Ind Turbomachinery AB, Sweden.
    Sjodin, Bjorn
    Siemens Ind Turbomachinery AB, Sweden.
    Moverare, Johan
    Linköping University, Department of Management and Engineering, Engineering Materials. Linköping University, Faculty of Science & Engineering.
    Simonsson, Kjell
    Linköping University, Department of Management and Engineering, Solid Mechanics. Linköping University, Faculty of Science & Engineering.
    Leidermark, Daniel
    Linköping University, Department of Management and Engineering, Solid Mechanics. Linköping University, Faculty of Science & Engineering.
    A FINITE ELEMENT STUDY OF THE EFFECT OF CRYSTAL ORIENTATION AND MISALIGNMENT ON THE CRACK DRIVING FORCE IN A SINGLE-CRYSTAL SUPERALLOY2016In: PROCEEDINGS OF THE ASME TURBO EXPO: TURBINE TECHNICAL CONFERENCE AND EXPOSITION, 2016, VOL 7A, AMER SOC MECHANICAL ENGINEERS , 2016, no UNSP V07AT28A002Conference paper (Refereed)
    Abstract [en]

    The elastic and plastic anisotropy of the single-crystal materials bring many difficulties in terms of modeling, evaluation and prediction of fatigue crack growth. In this paper a single-crystal material model has been adopted to a finite element-environment, which is paired with a crack growth tool. All simulations are performed in a three-dimensional context. This methodology makes it possible to analyze complex finite element-models, which are more application-near than traditional two-dimensional models. The influence of the crystal orientation, as well as the influence of misalignments of the crystal orientation due to the casting process are investigated. It is shown that both the crystal orientation and the misalignment from the ideal crystal orientation are important for the crack driving force. The realistic maximum limit of 10 degrees misalignment is considered. It can be seen that crack growth behavior is highly influenced by the misalignment. This knowledge is of great interest for the industry in order to evaluate the crack growth in single-crystal components more accurately.

  • 45.
    Josefsson, Ann
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Obstetrics and gynecology . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre of Paediatrics and Gynecology and Obstetrics, Department of Gynecology and Obstetrics in Linköping.
    Sydsjö, Gunilla
    Linköping University, Department of Clinical and Experimental Medicine, Obstetrics and gynecology . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre of Paediatrics and Gynecology and Obstetrics, Department of Gynecology and Obstetrics in Linköping.
    A follow-up study of postnatal depressed women: Recurrent maternal depressive symptoms and child behaviour after four years2007In: Archives of Women's Mental Health, ISSN 1434-1816, Vol. 10, no 4, 141-145 p.Article in journal (Refereed)
    Abstract [en]

    Objective: To investigate the prevalence of depressive symptoms and self reported health of women who have shown previous postpartum depressive symptoms. To examine the behavior of four-year-old children born to mothers affected by postpartum depression.

    Methods: Longitudinal study. The index group (n = 251) constituted of all women with postpartum depressive symptoms on the Edinburgh Postnatal Depression Scale (EPDS), in a population-based study made in the late 1990s. The control group (n = 502) consisted of women without postpartum depressive symptoms on the EPDS at the same occasion. Approximately four years after delivery these women were asked to answer a short questionnaire on general health, the EPDS, and also to assess their child’s behavior with the Richman Pre-School Behaviour Checklist. Results: Women with a history of postpartum depressive symptoms were approximately 6 times more likely to have recurrent depressive symptoms (OR = 5.82, 95% CI: 3.79–8.93), compared to those without postpartum depressive symptoms, and they were also more likely to experience physical and mental illness. Although postpartum depressive symptoms in the mothers were involved in explaining the likelihood of behavioral problems in their four-year-old children, mothers with current depressive symptoms were the most likely to have a child with behavioral problems (OR = 4.71, 95% CI: 1.88–11.78). Conclusion: Postpartum depressive illness constitutes a risk for future illness as well as maternal perceived behavioral problems in offspring. In order to diminish long-term adverse consequences for the mother and the child there is a great need to recognize and treat women with postpartum depressive symptoms as early as possible.

  • 46.
    Abbasi, Rizwan
    Linköping University, Department of Computer and Information Science. Linköping University, The Institute of Technology.
    A Framework For Interacting With Parameterized and Infinite State Verification Tools2013Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    We develop a tool to explore the behavior of parameterized systems (i.e., systems consisting of an arbitrary number of identical processes that synchronize using shared variables or global communications) and to ease user interaction with tools that verify them. The tool includes a user friendly GUI that allows the user to describe a parameterized system and to perform guided, interactive or random simulation. This tool empowers the user to plug in several independent verifiers to perform verification. A mockup verifier is developed in order to facilitate the development of the tool and testing the required functionalities. The mockup verifier involves parsing descriptions of the parameterized systems to be analyzed. In order to interact with the verifier, the tool is user friendly and flexible in the sense that the user can plug in a verifier developed in any language as long as it allows to perform a number of basic computations on the parameterized system (such as the set of enabled transitions or the set of successor configurations). In order to plug in a new tool, our tool needs to be able to make use of these operations, for instance using a wrapper written for a verifier particular to a class of parameterized systems. Given these operations, our tool enables the user to carry out various types of simulations like random, interactive or guided simulations. Moreover, our tool can submit verification queries to the underlying verifier and walk the user through the generated counter examples as if it was a simulation session.

  • 47.
    Wzorek, Mariusz
    et al.
    Linköping University, Department of Computer and Information Science, Artificial Intelligence and Integrated Computer Systems. Linköping University, Faculty of Science & Engineering.
    Berger, Cyrille
    Linköping University, Department of Computer and Information Science, Artificial Intelligence and Integrated Computer Systems. Linköping University, Faculty of Science & Engineering.
    Doherty, Patrick
    Linköping University, Department of Computer and Information Science, Artificial Intelligence and Integrated Computer Systems. Linköping University, Faculty of Science & Engineering.
    A Framework for Safe Navigation of Unmanned Aerial Vehicles in Unknown Environments2017In: 25th International Conference on Systems Engineering, 2017Conference paper (Refereed)
    Abstract [en]

    This paper presents a software framework which combines reactive collision avoidance control approach with path planning techniques for the purpose of safe navigation of multiple Unmanned Aerial Vehicles (UAVs) operating in unknown environments. The system proposed leverages advantages of using a fast local sense-and-react type control which guarantees real-time execution with computationally demanding path planning algorithms which generate globally optimal plans. A number of probabilistic path planning algorithms based on Probabilistic Roadmaps and Rapidly- Exploring Random Trees have been integrated. Additionally, the system uses a reactive controller based on Optimal Reciprocal Collision Avoidance (ORCA) for path execution and fast sense-and-avoid behavior. During the mission execution a 3D map representation of the environment is build incrementally and used for path planning. A prototype implementation on a small scale quad-rotor platform has been developed. The UAV used in the experiments was equipped with a structured-light depth sensor to obtain information about the environment in form of occupancy grid map. The system has been tested in a number of simulated missions as well as in real flights and the results of the evaluations are presented. 

  • 48.
    Olstam, Johan
    et al.
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Lundgren, Jan
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Adlers, Mikael
    Swedish National Road and Transport Research Institute (VTI), VTI, SE-581 95 Linköping, Sweden.
    Matstoms, Pontus
    Swedish National Road and Transport Research Institute (VTI), VTI, SE-581 95 Linköping, Sweden.
    A Framework for Simulation of Surrounding Vehicles in Driving Simulators2008In: ACM Transactions on Modeling and Computer Simulation, ISSN 1049-3301, E-ISSN 1558-1195, Vol. 18, no 3Article in journal (Refereed)
    Abstract [en]

    This article describes a framework for generation and simulation of surrounding vehicles in a driving simulator. The proposed framework generates a traffic stream, corresponding to a given target flow and simulates realistic interactions between vehicles. The framework is based on an approach in which only a limited area around the driving simulator vehicle is simulated. This closest neighborhood is divided into one inner area and two outer areas. Vehicles in the inner area are simulated according to a microscopic simulation model including advanced submodels for driving behavior while vehicles in the outer areas are updated according to a less time-consuming mesoscopic simulation model. The presented work includes a new framework for generating and simulating vehicles within a moving area. It also includes the development of an enhanced model for overtakings and a simple mesoscopic traffic model. The framework has been validated on the number of vehicles that catch up with the driving simulator vehicle and vice versa. The agreement is good for active and passive catch-ups on rural roads and for passive catch-ups on freeways, but less good for active catch-ups on freeways. The reason for this seems to be deficiencies in the utilized lane-changing model. It has been verified that the framework is able to achieve the target flow and that there is a gain in computational time of using the outer areas. The framework has also been tested within the VTI Driving simulator III.

  • 49.
    Ahlström, Christer
    et al.
    Swedish National Road and Transport Research Institute, Linköping, Sweden.
    Kircher, Katja
    Swedish National Road and Transport Research Institute, Linköping, Sweden.
    Kircher, Albert
    Östergötlands Läns Landsting, Heart and Medicine Center, Department of Clinical Physiology in Linköping.
    A Gaze-Based Driver Distraction Warning System and Its Effect on Visual Behavior2013In: IEEE transactions on intelligent transportation systems (Print), ISSN 1524-9050, E-ISSN 1558-0016, Vol. 14, no 2, 965-973 p.Article in journal (Refereed)
    Abstract [en]

    Driver distraction is a contributing factor to many crashes; therefore, a real-time distraction warning system should have the potential to mitigate or circumvent many of these crashes. The objective of this paper is to investigate the usefulness of a real-time distraction detection algorithm called AttenD. The evaluation is based on data from an extended field study comprising seven drivers who drove on an average of 4351 +/- 2181 km in a naturalistic setting. Visual behavior was investigated both on a global scale and on a local scale in the surroundings of each warning. An increase in the percentage of glances at the rear-view mirror and a decrease in the amount of glances at the center console were found. The results also show that visual time sharing decreased in duration from 9.94 to 9.20 s due to the warnings, that the time from fully attentive to warning decreased from 3.20 to 3.03 s, and that the time from warning to full attentiveness decreased from 6.02 to 5.46 s. The limited number of participants does not allow any generalizable conclusions, but a trend toward improved visual behavior could be observed. This is a promising start for further improvements of the algorithm and the warning strategy.

  • 50.
    Edell-Gustafsson, Ulla
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Nursing Science.
    Svanborg, Eva
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Neuroscience and Locomotion, Clinical Neurophysiology. Östergötlands Läns Landsting, Reconstruction Centre, Department of Neurophysiology UHL.
    Swahn, Eva
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Cardiology. Östergötlands Läns Landsting, Heart Centre, Department of Cardiology.
    A gender perspective on sleeplessness behavior, effects of sleep loss, and coping resources in patients with stable coronary artery disease2006In: Heart & Lung, ISSN 0147-9563, E-ISSN 1527-3288, Vol. 35, no 2, 75-89 p.Article in journal (Refereed)
    Abstract [en]

    OBJECTIVE: The primary aim of this study was to systematically compare perceived sleep quality, sleeplessness behavior, sense of mastery, self-esteem, depression, subjective health, and effects of sleep loss in men and women with stable coronary artery disease (CAD). Further aims were to determine possible predictors of poor sleep quality and sense of mastery, as well as the consequences of too little sleep. METHODS: Comparative-correlation and predictive design were used. Patients with a history of stable angina pectoris scheduled to undergo coronary angiography at Linköping University Hospital in Sweden were included. There were 47 women and 88 men (mean age 62.4 years) with CAD. Structured interviews using validated questionnaires covered sleep quality and sleep habits, effects of sleep loss, psychologic resources, and depression. RESULTS: Multiple stepwise regression analysis showed that sleeplessness behavior, depressed mood, female gender, and pharmacologic treatments with inflammation inhibitors significantly (P < .0001) accounted for the variance of poorer sleep quality. The analysis also showed that the following factors in descending order significantly accounted (P < .0001) for the outcome of sleep quality: inability to feel refreshed by sleep, difficulty in maintaining sleep, gastrointestinal problems, too little sleep, final morning awakening time, sleep onset latency, lying down because of daytime tiredness, and daytime physical tiredness. CONCLUSIONS: Compared with men, women with stable CAD may be especially at risk of experiencing poor sleep quality, even when sleeplessness behavior and pharmacologic treatments with inflammation inhibitors are controlled. It is also possible that they may be more at risk of depressed mood. Copyright © 2006 by Mosby, Inc.

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