In the last decades, computational models have become useful tools for studying biological neural networks. These models are typically constrained by either behavioural data from neuropsychological studies or by biological data from neuroscience. One model of the latter kind is the Bayesian Confidence Propagating Neural Network (BCPNN) - an attractor network with a Bayesian learning rule which has been proposed as a model for various types of memory. In this thesis, I have further studied the potential of the BCPNN in short-term sequential memory. More specifically, I have investigated if the network can be used to qualitatively replicate behaviours of immediate verbal serial recall, and thereby offer insight into the network-level mechanisms which give rise to these behaviours. The simulations showed that the model was able to reproduce various benchmark effects such as the word length and irrelevant speech effects. It could also simulate the bow shaped positional accuracy curve as well as some backward recall if the to-be recalled sequence was short enough. Finally, the model showed some ability to handle sequences with repeated patterns. However, the current model architecture was not sufficient for simulating the effects of rhythm such as temporally grouping the inputs or stressing a specific element in the sequence. Overall, even though the model is not complete, it showed promising results as a tool for investigating biological memory and it could explain various benchmark behaviours in immediate serial recall through neuroscientifically inspired learning rules and architecture. / Under de senaste årtionden har datorsimulationer blivit ett allt mer populärt verktyg för att undersöka biologiska neurala nätverk. Dessa modeller är vanligtvis inspirerade av antingen beteendedata från neuropsykologiska studier eller av biologisk data från neurovetenskapen. En modell av den senare typen är ett Bayesian Confidence Propagating Neural Network (BCPNN) - ett autoassociativt nätverk med en Bayesiansk inlärningsregel, vilket tidigare har använts för att modellera flera typer av minne. I det här examensarbetet har jag vidare undersökt om nätverket kan användas som en modell för sekventiellt korttidsminne genom att undersöka dess förmåga att replikera beteenden inom verbalt sekventiellt korttidsminne. Experimenten visade att modellen kunde simulera ett flertal viktiga nyckeleffekter såsom the word length effect och the irrelevant speech effect. Däröver kunde modellen även simulera den bågformade kurvan som beskriver andelen lyckade repetitioner som en funktion av position, och den kunde dessutom repetera korta sekvenser baklänges. Modellen visade också på viss förmåga att hantera sekvenser där ett element återkom senare i sekvensen. Den nuvarande modellen var däremot inte tillräcklig för att simulera effekterna som tillkommer av rytm, såsom temporär gruppering eller en betoning på specifika element i sekvensen. I sin helhet ser modellen däremot lovande ut, även om den inte är fullständig i sin nuvarande form, då den kunde simulera ett flertal viktiga nyckeleffekter och förklara dessa med hjälp av neurovetenskapligt inspirerade inlärningsregler.

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Master of Science / Department of Family Studies and Human Services / Jared Anderson / Using data from young adults (N = 224) living in Beijing and Guangzhou, China this study examined the direct association between frequency of pornography use and relationship confidence and indirect associations through depression symptoms and physical assault. Results using structural equation modeling demonstrated that higher frequency of pornography use was indirectly linked with lower relationship confidence via depression symptoms and physical assault. These findings are informed by Social Constructionist Theory (Gergen, 1985), which considers how individuals take what they understand from their culture, exposure to material such as pornography, and other social experiences to develop and make meaning of who they are within their relational context.

Published Article / First-year university students make judgements about their capabilities in mathematics which mainly stem from their past school experiences. It is against this background that the researchers decided to conduct a study with the aim of assessing the academic behavioural confidence of first-year students enrolled in the B.Ed. (FET): Natural Sciences programme and the B.Ed. (FET): Economic and Management Sciences programme offered by the School of Teacher Education at the Central University of Technology, Free State. Bandura's (1986) Social Cognitive Theory is the overarching theoretical framework of the self-efficacy construct and therefore also for this study. A quantitative approach was followed and the Academic Behavioural Confidence scale (ABC) designed by Sander and Sanders (2006), was adopted for use in the study. The study sought to first of all determine whether a significant difference in the academic behavioural confidence of the first-year students within the Natural Sciences and Economic and Management Sciences programmes does exist. It furthermore wanted to determine if a significant difference in the academic behavioural confidence between male and female students within these two programmes exists. The results indicated that there is a significant difference in the academic behavioural confidence of the NS and EMS groups. There is, however, no significant difference between male and female students within and between the two groups. Based on the findings some recommendations on dealing with first-year students have been made.

Electronic service in the public sector is a unique tool to facilitate communication between citizens and their government. These services have a lot of advantages such as making life easier for citizens, time saving, increasing reliability and reducing the cost on the government side. Delivering reliable and easy digital services is obviously a crucial demand for the satisfaction for the end user which is the Swedish citizen in this survey. When electronic services do not satisfy user needs, the cost increases and confidence against authorities decreases. This study aims to give an understanding of how authorities create their electronic services pursuing citizens’ confidence. The theoretical framework of the research aims to describe restrictions and facilities in the process of creating an electronic service. The study targeted four authorities: Arbetsförmedlingen, Försäkringskassan, Migrationsverket and Skatteverket, which all were interviewed through semi-structured interviews with open questions and answers and data has been collected. The study finds that involving users in the development process leads to increasing confidence. The theoretical framework and empirical study have resulted in a new model to identify restrictions while creating new electronic services, which are time and law- changes. / Lagändringar och krav som regeringen ställer på statliga myndigheter ger upphov till att dessa konsekvent måste digitalisera mer, arbeta effektivare och användarinvolverat. I samband med utökade digitaliseringen blir e-tjänsterna mer komplexa och därmed svåra för medborgarna att använda och lita på informationen. När e-tjänsterna inte uppfyller användarnas behov ökar kostnaderna och förtroendet för myndigheten minskar. Studien avser att ge förståelse om hur myndigheter utvecklar sina e-tjänster i strävan efter ökat förtroende. Studiens teoretiska ramverk ämnar beskriva vilka begränsningar och möjligheter myndigheterna kan identifiera i samband med skapandet av nya e-tjänster för att öka medborgarnas förtroende. Urvalet bestod av fyra statliga myndigheter som rangordnades först och sist i SOMs listan 2012-2013. Respondenterna var: Arbetsförmedlingen, Försäkringskassan, Migrationsverket och Skatteverket. Studiens empiriska data har inhämtats genom semistrukturerade intervjuer. I studien utgick vi från ett abduktivt angreppssätt där öppna frågor ställdes. Studien kom fram till att användarinvolvering under utvecklingsprocessen leder till ökat förtroende. Teoretiska ramverket och studiens empiri har gett upphov till en ny modell för att identifiera begränsningar vid skapandet av nya e-tjänster, vilka är tid och lagändringar.

Services based on the Information and Communications Technologies (ICT) are present more and more in the lives of people. The advancement of ICT in technical and social acceptance terms has led the creation of new models of service provision. These provision models involve further integration with people's activities so that are not only present in their professions or civic space but also in a more intimate areas related to their own identity. So it is now common to find services aware of user's health, their domestic habits, ideology, etc. Therefore, the analysis of existing services must be open out to include other aspects related to the way of being and feeling of their members. This way is possible to ensure both the technical correctness of its features as promoting safe and respectful solutions both of civic rights as the way of being and feeling of its members. From the engineering point of view, the user perspective has historically encompassed under the concept of technological acceptance. Within this field can be interpreted as friendly solutions adapted to users will encourage the acceptance by them. Solution acceptance is desirable although it is difficult to ensure. This difficulty is due to the lack of the number of variables that affect the acceptance of technological solutions and the difficulty of optimizing the known variables. In this thesis it is studied and characterized one of the variables that affect the acceptance of existing services: confidence. Confidence is defined in psychological terms, providing its characterization with the aim of be used in typical methods of engineering. Also different tools are proposed to facilitate the optimization of this confidence in services whose complexity establishes this variable in a basic issue to improve acceptance. Health services deployed in a home have been chosen as working context for this thesis. This scenario presents a number of acceptance restrictions on the technology used to create services and how they manage the acquired user information. It comes to highly sensitive and delocalized services that can affect to the user's perception of the environment, the home, and generate fear or rejection to prevent final adoption as a valid solution. Once defined the generic framework, the main objective of this dissertation is focused on promote the acceptance of new pervasive and personalized health services and their deployment in domestic intelligent environments through a layout that promotes a psychological state of confidence in users. To achieve this goal, a set of results, both conceptual, technological and experimental, have been provided. In particular, it has offered a complete characterization of the feeling of confidence from a viewpoint of engineering and a definition of sensitive or delocalized pervasive service. Furthermore, a method for the inclusion of the Interaction Design discipline in engineering processes of such services through a set of patterns of interaction is offered. Finally, this thesis provides the development of a software architecture to ensure proper deployment of these pervasive sensitive services in intelligent environments in a confident way. Discussion of the results suggests the extension of the deployment model to different services of the Information Society that handle sensitive data both in the context of the digital home and other settings where the user perform everyday activities such as work spaces or schools. The future work lines include the imminent need to apply the results to ongoing developments, within research projects in those the author takes part, and the development of new research lines aimed at creating new spaces and interaction technologies as advanced accessible interfaces, toys of the future, confident visualization systems or security systems based on the condition of the user. / Tjänster baserade på informations- och kommunikationsteknik (IKT) blir allt mer vanligare i människors liv. För att främja acceptansen för IKT i både tekniska och sociala aspekter av människors liv har nya modeller för dessa tjänster skapats. Dessa modeller har en närmare knytning till människors verksamhet så att de inte bara förekommer i deras yrken eller fritid men också i mer intima områden som anknyter till individens egen identitet. Det är nu därför vanligt att hitta tjänster som tar hänsyn till användarens hälsa, vanor, ideologi, etc.  En analys av befintliga tjänster måste inkludera dessa aspekter men även användarnas känsla av identitet och medlemskap. På detta sätt är det möjligt att säkerställa den tekniska riktigheten hos dessa funktioner som i sin tur borgar för säkra och respektfulla lösningar som tar hänsyn till medlemmarnas medborgerliga rättigheter likväl som deras känsla av identitet och medlemskap. Historiskt sett, och ur ett tekniskt perspektiv, har användarperspektivet omfattats under begreppet teknisk acceptans. Inom detta område har användarvänliga lösningar anpassade till användarna själva uppmuntrat acceptans av dem. Acceptans av lösningar är önskvärt även om det är svårt att säkerställa. Denna svårighet beror på avsaknaden av antalet variabler som påverkar acceptansen av tekniska lösningar och svårigheten att optimera de kända variablerna. I denna avhandling studeras och karaktäriseras en av de variabler som påverkar acceptansen av befintliga tjänster: förtroende. Förtroendet definieras i psykologiska termer med syftet att kunna använda termen i typiska metoder för teknik. Det föreslås också olika verktyg för att underlätta optimering av detta förtroende inom tjänstesektorn. Hälso- och sjukvård i hemmet har valts som scenario för denna avhandling. Detta scenario presenterar ett antal restriktioner med avseende på acceptansen av den teknik som används för att skapa tjänster och hur dessa tjänster hanterar den förvärvade användarinformationen. För användaren är situationen mycket känslig och de erbjudna tjänsterna kan påverka användarens uppfattning av miljön och hemmet och/eller generera rädsla eller avsmak för att acceptera lösningen. När den generiska ramen är etablerad är det huvudsakliga syftet med denna avhandling att främja acceptans av nya tjänster för personlig hälsovård och deras användning i hemmet. Detta skall uppnås genom en layout som främjar ett psykologiskt förtroende hos användarna. För att uppnå detta mål har en uppsättning resultat, både begreppsmässiga, tekniska och experimentella, analyserats. Framför allt har en fullständig karaktärisering gjorts av känslan av förtroende från en teknologisk synvinkel och en definition av en känslig och allomfattande tjänst. Dessutom framläggs en metod för införandet av interaktionsdesign i de aktuella tjänsterna genom ett antal interaktionsmönster. Slutligen behandlar denna avhandling utvecklingen av en mjukvaruarkitektur för att säkerställa en korrekt användning av dessa känsliga tjänster. Resultaten pekar på att distributionsmodellen även kan användas för andra tjänster i informationssamhället där användaren utför vardagliga sysslor, såsom i det digitala hemmet eller andra miljöer (t.ex. skolor och arbetsplatser), där känsliga uppgifter hanteras. De framtida arbetsuppgifterna omfattar det överhängande behovet av att tillämpa resultaten på den pågående utvecklingen av forskningsprojekt som författaren är involverad i. Detta omfattar även utveckling av ny forskning som syftar till att skapa ny interaktionsteknik t.ex. avancerade gränssnitt, framtida leksaker, säkra visualiseringssystem eller säkerhetssystem baserat på användarens hälsa/tillstånd. / <p>This PhD research has been conducted under a double PhD agreement degree between the School of Telecommunications Systems and Engineering (ETSIST) at the Technical University of Madrid (UPM) in Spain and the School of Technology and Health (STH) at the Royal Institute of Technology (KTH) in Sweden.</p><p>QC 20160129</p>

Thesis (PhD)--Stellenbosch University, 2011. / ENGLISH ABSTRACT: Measures of inequality, also used as measures of concentration or diversity, are very popular in economics and especially in measuring the inequality in income or wealth within a population and between populations. However, they have applications in many other fields, e.g. in ecology, linguistics, sociology, demography, epidemiology and information science. A large number of measures have been proposed to measure inequality. Examples include the Gini index, the generalized entropy, the Atkinson and the quintile share ratio measures. Inequality measures are inherently dependent on the tails of the population (underlying distribution) and therefore their estimators are typically sensitive to data from these tails (nonrobust). For example, income distributions often exhibit a long tail to the right, leading to the frequent occurrence of large values in samples. Since the usual estimators are based on the empirical distribution function, they are usually nonrobust to such large values. Furthermore, heavy-tailed distributions often occur in real life data sets, remedial action therefore needs to be taken in such cases. The remedial action can be either a trimming of the extreme data or a modification of the (traditional) estimator to make it more robust to extreme observations. In this thesis we follow the second option, modifying the traditional empirical distribution function as estimator to make it more robust. Using results from extreme value theory, we develop more reliable distribution estimators in a semi-parametric setting. These new estimators of the distribution then form the basis for more robust estimators of the measures of inequality. These estimators are developed for the four most popular classes of measures, viz. Gini, generalized entropy, Atkinson and quintile share ratio. Properties of such estimators are studied especially via simulation. Using limiting distribution theory and the bootstrap methodology, approximate confidence intervals were derived. Through the various simulation studies, the proposed estimators are compared to the standard ones in terms of mean squared error, relative impact of contamination, confidence interval length and coverage probability. In these studies the semi-parametric methods show a clear improvement over the standard ones. The theoretical properties of the quintile share ratio have not been studied much. Consequently, we also derive its influence function as well as the limiting normal distribution of its nonparametric estimator. These results have not previously been published. In order to illustrate the methods developed, we apply them to a number of real life data sets. Using such data sets, we show how the methods can be used in practice for inference. In order to choose between the candidate parametric distributions, use is made of a measure of sample representativeness from the literature. These illustrations show that the proposed methods can be used to reach satisfactory conclusions in real life problems. / AFRIKAANSE OPSOMMING: Maatstawwe van ongelykheid, wat ook gebruik word as maatstawwe van konsentrasie of diversiteit, is baie populêr in ekonomie en veral vir die kwantifisering van ongelykheid in inkomste of welvaart binne ’n populasie en tussen populasies. Hulle het egter ook toepassings in baie ander dissiplines, byvoorbeeld ekologie, linguistiek, sosiologie, demografie, epidemiologie en inligtingskunde. Daar bestaan reeds verskeie maatstawwe vir die meet van ongelykheid. Voorbeelde sluit in die Gini indeks, die veralgemeende entropie maatstaf, die Atkinson maatstaf en die kwintiel aandeel verhouding. Maatstawwe van ongelykheid is inherent afhanklik van die sterte van die populasie (onderliggende verdeling) en beramers daarvoor is tipies dus sensitief vir data uit sodanige sterte (nierobuust). Inkomste verdelings het byvoorbeeld dikwels lang regtersterte, wat kan lei tot die voorkoms van groot waardes in steekproewe. Die tradisionele beramers is gebaseer op die empiriese verdelingsfunksie, en hulle is gewoonlik dus nierobuust teenoor sodanige groot waardes nie. Aangesien swaarstert verdelings dikwels voorkom in werklike data, moet regstellings gemaak word in sulke gevalle. Hierdie regstellings kan bestaan uit of die afknip van ekstreme data of die aanpassing van tradisionele beramers om hulle meer robuust te maak teen ekstreme waardes. In hierdie tesis word die tweede opsie gevolg deurdat die tradisionele empiriese verdelingsfunksie as beramer aangepas word om dit meer robuust te maak. Deur gebruik te maak van resultate van ekstreemwaardeteorie, word meer betroubare beramers vir verdelings ontwikkel in ’n semi-parametriese opset. Hierdie nuwe beramers van die verdeling vorm dan die basis vir meer robuuste beramers van maatstawwe van ongelykheid. Hierdie beramers word ontwikkel vir die vier mees populêre klasse van maatstawwe, naamlik Gini, veralgemeende entropie, Atkinson en kwintiel aandeel verhouding. Eienskappe van hierdie beramers word bestudeer, veral met behulp van simulasie studies. Benaderde vertrouensintervalle word ontwikkel deur gebruik te maak van limietverdelingsteorie en die skoenlus metodologie. Die voorgestelde beramers word vergelyk met tradisionele beramers deur middel van verskeie simulasie studies. Die vergelyking word gedoen in terme van gemiddelde kwadraat fout, relatiewe impak van kontaminasie, vertrouensinterval lengte en oordekkingswaarskynlikheid. In hierdie studies toon die semi-parametriese metodes ’n duidelike verbetering teenoor die tradisionele metodes. Die kwintiel aandeel verhouding se teoretiese eienskappe het nog nie veel aandag in die literatuur geniet nie. Gevolglik lei ons die invloedfunksie asook die asimptotiese verdeling van die nie-parametriese beramer daarvoor af. Ten einde die metodes wat ontwikkel is te illustreer, word dit toegepas op ’n aantal werklike datastelle. Hierdie toepassings toon hoe die metodes gebruik kan word vir inferensie in die praktyk. ’n Metode in die literatuur vir steekproefverteenwoordiging word voorgestel en gebruik om ’n keuse tussen die kandidaat parametriese verdelings te maak. Hierdie voorbeelde toon dat die voorgestelde metodes met vrug gebruik kan word om bevredigende gevolgtrekkings in die praktyk te maak.

Dissertation (PhD)--Stellenbosch University, 2002. / ENGLISH ABSTRACT: In this thesis we construct a central confidence interval for a smooth scalar non-linear function of parameter vector f3 in a single general linear regression model Y = X f3 + c. We do this by first developing an Edgeworth expansion for the distribution function of a standardised point estimator. The confidence interval is then constructed in the manner discussed. Simulation studies reported at the end of the thesis show the interval to perform well in many small-sample situations. Central to the development of the Edgeworth expansion is our use of the index notation which, in statistics, has been popularised by McCullagh (1984, 1987). The contributions made in this thesis are of two kinds. We revisit the complex McCullagh Index Notation, modify and extend it in certain respects as well as repackage it in the manner that is more accessible to other researchers. On the new contributions, in addition to the introduction of a new small-sample confidence interval, we extend the theory of stochastic polynomials (SP) in three respects. A method, which we believe to be the simplest and most transparent to date, is proposed for deriving cumulants for these. Secondly, the theory of the cumulants of the SP is developed both in the context of Edgeworth expansion as well as in the regression setting. Thirdly, our new method enables us to propose a natural alternative to the method of Hall (1992a, 1992b) regarding skewness-reduction in Edgeworth expansions. / AFRIKAANSE OPSOMMING: In hierdie proefskrif word daar aandag gegee aan die konstruksie van 'n sentrale vertrouensinterval vir 'n gladde skalare nie-lineêre funksie van die parametervektor (3 in 'n enkele algemene lineêre regressiemodel y = X (3 + e.. Dit behels eerstens die ontwikkeling van 'n Edgeworth uitbreiding vir die verdelingsfunksie van 'n gestandaardiseerde puntberamer. Die vertrouensinterval word dan op grond van hierdie uitbreiding gekonstrueer. Simulasiestudies wat aan die einde van die proefskrif gerapporteer word, toon dat die voorgestelde interval goed vertoon in verskeie klein-steekproef gevalle. Die gebruik van indeksnotasie, wat in die statistiek deur McCullagh (1984, 1987) bekendgestel is, speel 'n sentrale rol in die ontwikkeling van die Edgeworth uitbreiding. Die bydrae wat in hierdie proefskrif gemaak word, is van 'n tweërlei aard. Die ingewikkelde Indeksnotasie van McCullagh word ondersoek, aangepas en ten opsigte van sekere aspekte uitgebrei. Die notasie word ook aangebied in 'n vorm wat dit hopelik meer toeganklik sal maak vir ander navorsers. Betreffende die bydrae wat gemaak word, word 'n nuwe klein-steekproef vertrouensinterval voorgestel, en word die teorie van stogastiese polinome (SP) ook in drie opsigte uitgebrei. 'n Metode word voorgestelom die kumulante van SP'e af te lei. Ons glo dat hierdie metode die duidelikste en eenvoudigste metode is wat tot dusver hiervoor voorgestel is. Tweedens word die teorie van die kumulante van SP'e ontwikkel binne die konteks van Edgeworth uitbreidings, sowel as die konteks van regressie. Derdens stelons nuwe metode ons in staat om 'n natuurlike alternatief voor te stel vir die metode van Hall (1992a, 1992b) vir die vermindering van skeefheid in Edgeworth uitbreidings.