Today’s 3D imaging techniques offer significant benefits over conventional 2D imaging techniques. The presence of natural depth information in the scene affords the observer an overall improved sense of reality and naturalness. A variety of systems attempting to reach this goal have been designed by many independent research groups, such as stereoscopic and auto-stereoscopic systems. Though the images displayed by such systems tend to cause eye strain, fatigue and headaches after prolonged viewing as users are required to focus on the screen plane/accommodation to converge their eyes to a point in space in a different plane/convergence. Holoscopy is a 3D technology that targets overcoming the above limitations of current 3D technology and was recently developed at Brunel University. This work is part W4.1 of the 3D VIVANT project that is funded by the EU under the ICT program and coordinated by Dr. Aman Aggoun at Brunel University, West London, UK. The objective of the work described in this thesis is to develop estimation and segmentation techniques that are capable of estimating precise 3D depth, and are applicable for holoscopic 3D imaging system. Particular emphasis is given to the task of automatic techniques i.e. favours algorithms with broad generalisation abilities, as no constraints are placed on the setting. Algorithms that provide invariance to most appearance based variation of objects in the scene (e.g. viewpoint changes, deformable objects, presence of noise and changes in lighting). Moreover, have the ability to estimate depth information from both types of holoscopic 3D images i.e. Unidirectional and Omni-directional which gives horizontal parallax and full parallax (vertical and horizontal), respectively. The main aim of this research is to develop 3D depth estimation and 3D image segmentation techniques with great precision. In particular, emphasis on automation of thresholding techniques and cues identifications for development of robust algorithms. A method for depth-through-disparity feature analysis has been built based on the existing correlation between the pixels at a one micro-lens pitch which has been exploited to extract the viewpoint images (VPIs). The corresponding displacement among the VPIs has been exploited to estimate the depth information map via setting and extracting reliable sets of local features. ii Feature-based-point and feature-based-edge are two novel automatic thresholding techniques for detecting and extracting features that have been used in this approach. These techniques offer a solution to the problem of setting and extracting reliable features automatically to improve the performance of the depth estimation related to the generalizations, speed and quality. Due to the resolution limitation of the extracted VPIs, obtaining an accurate 3D depth map is challenging. Therefore, sub-pixel shift and integration is a novel interpolation technique that has been used in this approach to generate super-resolution VPIs. By shift and integration of a set of up-sampled low resolution VPIs, the new information contained in each viewpoint is exploited to obtain a super resolution VPI. This produces a high resolution perspective VPI with wide Field Of View (FOV). This means that the holoscopic 3D image system can be converted into a multi-view 3D image pixel format. Both depth accuracy and a fast execution time have been achieved that improved the 3D depth map. For a 3D object to be recognized the related foreground regions and depth information map needs to be identified. Two novel unsupervised segmentation methods that generate interactive depth maps from single viewpoint segmentation were developed. Both techniques offer new improvements over the existing methods due to their simple use and being fully automatic; therefore, producing the 3D depth interactive map without human interaction. The final contribution is a performance evaluation, to provide an equitable measurement for the extent of the success of the proposed techniques for foreground object segmentation, 3D depth interactive map creation and the generation of 2D super-resolution viewpoint techniques. The no-reference image quality assessment metrics and their correlation with the human perception of quality are used with the help of human participants in a subjective manner.

Although sitting is a large part of everyday life is the influence of the sitting positions and chair design on pressure and load distribution as well as comfort for transfemoral amputees quite unexplored. The aim of this study was therefore to examine this further. Two transfemorally amputated females (49 and 57 years old) participated in the study. Three positions were examined for each subject; sitting without foot support and sitting with the knee joints flexed 90◦ and 105◦. The pressure inside the socket was measured by two pressure sensors, placed distally and proximally on the posterior wall inside the socket. The lengthwise pressure distribution and the sidewise load distribution between the socket and the underlying material was measured by a pressure mat. In addition to this, the subjects answered a questionnaire regarding the subjective comfort for each position.  The result showed that the pressure underneath the socket were higher distally than proximally without foot support. The pressure transferred proximally as the knee became more flexed. The most even load distribution sidewise was found when the subjects sat with their knees flexed 105 degrees. Sitting with the knees flexed 90◦ was ranked as the most comfortable position. No conclusion could be made regarding the pressure inside of the socket. Additionally, according to this study the level of comfort does not have any clear relation with the sidewise load distribution or the longitudinal pressure distribution. / En stor del av livet spenderas sittandes, men den påverkan som sittposition och stoldesign har på tryckfördelning och komfort för transfemoralt amputerade är ganska outforskat. Studien ämnar därför undersöka detta. Två transfemoralt amputerade kvinnor (49 och 57 år) medverkade i studien. Tre sittpositioner undersöktes för varje testperson; sittande utan fotstöd samt sittande med knäleden i 90◦ respektive 105◦ flexion. Trycket inuti hylsan mättes med hjälp av två trycksensorer, som placerades distalt och proximalt på den bakre hylsväggen. Tryckfördelningen i längsriktningen och lastfördelningen i sidled mellan hylsan och underlaget mättes med en tryckmatta. Förutom detta svarade testpersonerna även på ett frågeformulär angående den subjektiva komforten för varje position. Resultatet visade att trycket under hylsan var högre distalt än proximalt när inget fotstöd användes. Trycket förflyttades proximalt då knät böjdes. Den mest jämna lastfördelningen mellan sidorna påträffades när knät var flekterat 105◦. Enligt frågeformuläret var den mest bekväma positionen den med 90◦ i knäleden. Ingen slutsats kunde göras angående trycket inuit hylsan. Ingen tydlig relation kunde heller inte hittas mellan den subjektiva komforten och tryck- eller lastfördelningen.

Kan lycka köpas för pengar? Prosocialt spenderande och lycka är ett nytt ämne inom forskning och har ännu inte studerats i Sverige. Föreliggande studie syftar till att utreda om prosocialt spenderande bidrar till en ökad grad av upplevd lycka hos studenter vilket tidigare forskning stödjer samt om det föreligger könsskillnader gällande prosocialt spenderande och upplevd lycka vilket inte forskningen stödjer inom området. Etthundratre personal- och arbetslivsstuderande varav 72 kvinnor och 31 män vid ett medelstort universitet i södra Sverige deltog. Ett randomiserat post-test-only experiment utfördes varav 51 deltagare utgjorde experimentgrupp och genomförde en intervention som innebar att de skänkte pengar till välgörenhet och 52 deltagare genomförde ett kognitivt test som kontrolluppgift. Efteråt uppmättes deltagarnas upplevda lycka med Subjective Happiness Scale. Statistisk prövning med tvåvägs-ANOVA visade ingen statistiskt signifikant skillnad mellan experiment och kontrollgrupp gällande upplevd lycka, vidare fanns inga skillnader mellan könen gällande upplevd lycka och prosocialt spenderande. Studiens resultat stöds inte av tidigare forskning. Studiens diskussion föreslår att vidare forskning inom området fokuserar på design och metodval. Storleken på summan som spenderas prosocialt påverkar troligen effekten gällande lycka i större utsträckning än vad som antagits. En undre gräns för att gynna lycka diskuteras. Relation till den som individen spenderar prosocialt på diskuteras och tros också påverka upplevd lycka. / Can happiness be bought with money? Prosocial spending and happiness is a new field within science and has yet to be studied in Sweden. The present study aims to investigate whether prosocial spending contributes to an increased level of happiness amongst students which previous research supports and also whether sexdifferences within prosocial spending and percieved happiness exists which current research does not support. One-hundred and three undergraduates of whom 72 were women and 31 men within a human resource and management-program participated, all studying at a medium-sized university in southern Sweden. A randomized post-test-only experiment was conducted in which 51 participants carried out a task where they were instructed to donate money to charity (experimental group) and 52 participants were instructed to complete a cognitive task (control group). Subsequently the participants levels of happiness were measured using the Subjective Happiness Scale. Statistical testing using a two-way ANOVA showed no statistically significant difference between the experimental and control groups regarding happiness, furthermore there were no sex differences regarding happiness and prosocial spending. The results of the present study are contradictory with previous research. The discussion of the present study suggests emphasis on method and design for further studies within the area. The amount of money spent prosocially is likely to have a greater impact on happiness than the present study presumed. A lower limit to promote happiness is discussed. Furthermore the relation between the individual who is prosocially spending and the recipient is discussed and is likely to have an impact on perceived happiness.

The overwhelming trend of the usage of multimedia services has raised the consumers' awareness about quality. Both service providers and consumers are interested in the delivered level of perceptual quality. The perceptual quality of an original video signal can get degraded due to compression and due to its transmission over a lossy network. Video quality assessment (VQA) has to be performed in order to gauge the level of video quality. Generally, it can be performed by following subjective methods, where a panel of humans judges the quality of video, or by using objective methods, where a computational model yields an estimate of the quality. Objective methods and specifically No-Reference (NR) or Reduced-Reference (RR) methods are preferable because they are practical for implementation in real-time scenarios. This doctoral thesis begins with a review of existing approaches proposed in the area of NR image and video quality assessment. In the review, recently proposed methods of visual quality assessment are classified into three categories. This is followed by the chapters related to the description of studies on the development of NR and RR methods as well as on conducting subjective experiments of VQA. In the case of NR methods, the required features are extracted from the coded bitstream of a video, and in the case of RR methods additional pixel-based information is used. Specifically, NR methods are developed with the help of suitable techniques of regression using artificial neural networks and least-squares support vector machines. Subsequently, in a later study, linear regression techniques are used to elaborate the interpretability of NR and RR models with respect to the selection of perceptually significant features. The presented studies on subjective experiments are performed using laboratory based and crowdsourcing platforms. In the laboratory based experiments, the focus has been on using standardized methods in order to generate datasets that can be used to validate objective methods of VQA. The subjective experiments performed through crowdsourcing relate to the investigation of non-standard methods in order to determine perceptual preference of various adaptation scenarios in the context of adaptive streaming of high-definition videos. Lastly, the use of adaptive gain equalizer in the modulation frequency domain for speech enhancement has been examined. To this end, two methods of demodulating speech signals namely spectral center of gravity carrier estimation and convex optimization have been studied.

This study examines whether eliciting self-evaluations increases or decreases the propensity of a productive agent to retaliate against an employer for paying compensation that the agent perceives to be too low for the work performed. Specifically, I consider a setting in which a principal knows more about the agent’s production than even the agent can observe. In such a setting, an agent might perceive that s/he is being underpaid if the principal pays less than the agent believes s/he deserves, especially if the agent is overconfident about his/her own productive ability. Such an agent could take retaliatory actions against the principal that would be costly to both parties. Self-evaluations could mitigate such tendencies if they result in compensation that is more aligned with agent self-perceptions. Alternatively, self-evaluations could worsen such tendencies if they reinforce the perceived inequity of compensation that does not match agent self-perceptions. I present experimental evidence from comparing a control condition without self-evaluations to three different forms of self-evaluation reports, finding evidence consistent with the premise that self-evaluations increase retaliatory actions and lower welfare. My findings show a cost to self-evaluations that thus far has not been sufficiently considered in the literature. / text

<p>Vilka faktorer som påverkar vår upplevelse av välbefinnande och lycka väcker stort intresse hos människor. Upplevt välbefinnande (subjective well-being) kan definieras som en individs subjektiva uppfattning om sin livstillfredställelse. Grunden för denna uppfattning bygger på hur den enskilda individen skattar och utvärderar sitt liv. Stabilitet i upplevt välbefinnande påverkas av såväl situationsbundna faktorer som personlighet och affekt. Syftet med denna kvantitativa rapport var att utifrån data från forskningsprogrammet IDA undersöka sambandsstrukturen mellan de olika delarna i begreppet upplevt välbefinnande: områdesspecifikt välbefinnande å ena sidan och generellt välbefinnande med allmän livstillfredställelse, positiv affekt och negativ affekt å andra sidan. Samt att hitta eventuella könsskillnader i dessa samband. Resultatet visade på starka samband mellan generellt och områdesspecifikt välbefinnande. Det allra starkaste sambandet konstaterades mellan tillfredställelse med familjeliv och allmän livstillfredställelse. Sambandet mellan yttre villkor för arbetstillfredställelse och generellt välbefinnande var starkare för män än för kvinnor, medan partialsambandet mellan tillfredställelse med partnerrelation och allmän livstillfredställelse var starkare för kvinnor. Diskussion förs kring resultatens överensstämmelse med tidigare forskning.</p>

<p>The present thesis concerns middle-aged women’s subjective well-being (SWB). The interest is focused on the importance of childhood factors, social circumstances, and personality for middle-aged women’s general SWB. Data were taken from the longitudinal research program Individual Development and Adaptation (IDA, Magnusson & Bergman, 2000) and concerned a sample of about 300 women. The main analyses were made on data collected at age 43, but data collected at age 13 and age 49 were also used to elucidate the purposes of this thesis. The results can be summarized as follows: 1) In a Swedish sample of middle-aged women, social circumstances had only a moderate effect on general SWB variables. The strongest relationship was found between marital status and global life satisfaction. When personality factors were controlled for, they wiped out nearly all relationships between the social circumstances variables and SWB, except for those between global life satisfaction and marital status or unemployment; 2) The level of general SWB was found to be considerably higher for Swedish employed women as compared to their counterparts in Lithuania and different socio-demographic variables predicted SWB in those two countries. For the Swedish sample, family-oriented variables were the strongest predictors of SWB, while for the Lithuanian sample income and educational level were more important; 3) Results from applying longitudinal structural equation modeling suggested that optimism in adolescence influenced optimism in middle age, which in its turn had both a direct influence on global life satisfaction and an indirect influence via the negative affect dimension. In relation to a number of different adjustment factors measured in adolescence it was found that optimism was the only factor that was constantly related to SWB 30 years later; 4) Typical patterns of general SWB were identified. Cluster analyses at age 43 and age 49 separately resulted in similar well-functioning six cluster solutions at both ages, indicating structural stability across six years. In addition to the typical high/low/average SWB clusters that could be to some degree expected from variable-oriented results, a cluster with intense affect and one with very low GLS emerged. All clusters except the latter one showed individual stability across six years.</p>

A particular field in research on judgment and decision making (JDM) is concerned with realism of confidence in one’s knowledge. An interesting finding is the so-called format dependence effect, which implies that assessment of the same probability distribution generates different conclusions about over- or underconfidence depending on the assessment format. In particular, expressing a belief about some unknown continuous quantity (e.g., a stock value) in the form of an intuitive confidence interval is severely prone to overconfidence as compared to expressing the belief as an assessment of a probability judgment. This thesis gives a tentative account of this finding in terms of a Naïve Sampling Model, which assumes that people accurately describe their available information stored in memory, but they are naïve in the sense that they treat sample properties as proper estimators of population properties (Study 1). The effect of this naivety is directly investigated empirically in Study 2. A prediction that short-term memory is a constraining factor for sample size in judgment, suggesting that experience per se does not eliminate overconfidence is investigated and verified in Study 3. Age-related increments in overconfidence were observed with intuitive confidence interval but not for probability judgment (Study 4). This thesis suggests that no cognitive processing bias (e.g., Tversky &amp; Kahneman, 1974) over and above naivety is needed to understand and explain the overconfidence “bias” with intuitive confidence interval and hence the format dependence effect.

Individualūs poreikiai ir asmeninė patirtis užima vis svarbesnę vietą sveikatos priežiūros sistemoje, plinta sveiko gyvenimo būdo idėjos. Subjektyviems poreikiams patenkinti šalia biomedicininio sveikatos gerinimo modelio atsiranda daugybė alternatyvių technikų bei sveikatos specialistų, siūlančių skirtingas sveikos gyvensenos strategijas. Šio darbo problema yra šiuolaikinėje visuomenėje atsirandantis sveikos gyvensenos strategijų pliuralizmas, siejamas su vartotojiškos kultūros, socialinės refleksijos ir pomaterialistinių vertybių atsiradimu. Biomedicina sveiką gyvenseną traktuoja kaip sveikatos gerinimo strategiją. Tačiau sveikos gyvensenos pasirinkimai susiję ne tik su sveikata, bet taip pat su tam tikro gyvenimo stiliaus pasirinkimu. Jei medicininės praktikos yra orientuotos į konkrečios problemos sprendimą, tai sveika gyvensena tampa kur kas platesniu reiškiniu. Todėl šiuo darbu siekiama atskleisti sveikos gyvensenos strategijų pasirinkimo motyvus, bei gyvenimo stiliaus raišką. Atlikus empirinių duomenų analizę paaiškėja, kad sveika gyvensena suvokiama kaip savirealizacijos, egzistencinio saugumo poreikio patenkinimo, subjektyvaus gerbūvio kūrimo priemonė. Sveikatos samprata peržengia vien biologinio poreikio ribas ir tampa saviraiškos piemone, sveikos gyvensenos vertybėmis grįstu savitu gyvenimo stiliumi. Sveikos gyvensenos praktikos ne tik stiprina sveikatą, bet subalansuojančiu ir kitas žmogaus gyvenimo sritis. / Individual needs and personal experience is gaining more importance in people’s health care system, and the patterns of healthy lifestyle are being spread along. To meet subjective needs of the people a number of alternative techniques and various health care specialists offering different lifestyle strategies appear next to the biomedical model of health promotion. The core question of the present paper is the plurality of healthy lifestyle strategies associated with the appearance of consumer culture, social reflection and post-materialistic values in today’s society. In biomedicine healthy lifestyle is seen as a strategy of health improvement. However, the patterns of healthy lifestyle are not only associated with health but also with certain choices of a living of life. If medical practice focuses on a specific problem, a healthy lifestyle then becomes a much broader phenomenon. Therefore this paper aims at revealing the motif choice of strategy of healthy lifestyle and the expression of lifestyle. The empirical analysis of the data showed that healthy lifestyle was perceived as a mean of self-realization, the satisfaction of the need of existential security and the development of subjective well-being. The concept of health goes beyond the limits of biological need becoming a mean of self-realization, a way of living based on values of healthy lifestyle. The practice of healthy lifestyle not only enhances one’s health but also becomes a much broader phenomenon equally... [to full text]

Psychosomatic health, including sleep, is important for adolescent well-being and daily functioning. Sleep difficulties are more seldom studied per se and whether there is socio-demographic variation in sleep difficulties among adolescents in Sweden is less known. The overall aim of the present study was to examine the frequency and social distribution of sleep difficulties among adolescents in Sweden. The child supplements of the Survey of Living Conditions, a Swedish nationally representative sample of ages 10-18, from years 2002 and 2003 were used (n=2531). Information from adolescents was linked to information from parents in a cross-sectional study design. Based on logistic regression analyses, variation in sleep difficulties was present according to gender, age, family structure, family economy, parent’s unemployment and residential area. No systematic sleep inequality by social class was found in the present study. The main results showed that adolescent girls, older age groups of adolescents, adolescents living in reconstituted families, living in families with a lack of cash margin, having unemployed parents and living in big cities reported sleep difficulties to a greater extent. Social factors, together with biological, psychological and cultural factors interact in explaining the variation in sleep difficulties.