O rápido crescimento das regiões urbanas tem impacto significativo nos sistemas de tráfego e transportes. Políticas de gerenciamento e estratégias de planejamento alternativas são claramente necessárias para o tratamento da capacidade limitada, e cada vez mais deficitária, das redes viárias. O conceito de Sistemas Inteligentes de Transportes (ITS) surge neste cenário; mais do que procurar aumentar a capacidade por meio de modificações físicas na infraestrutura, sua premissa baseia-se na utilização de tecnologias avançadas de comunicação e computação para melhor gerir os recursos de tráfego e transportes atuais. Influenciar o padrão do comportamento dos usuários é um desafio que tem estimulado muita pesquisa na área de ITS, onde fatores humanos passam a ter grande importância na modelagem, simulação e avaliação dessa abordagem inovadora. Este trabalho tem como foco a utilização de Sistemas Multiagentes (MAS) na representação dos sistemas de tráfego e transporte, com base nas novasmedidas de desempenho impostas pelas tecnologias ITS. As características de agentes têm grande potencial para representar componentes geográfica e funcionalmente distribuídos, como a maioria dos elementos no domínio da aplicação. Uma arquitetura BDI (beliefs, desires, intentions) é apresentada como alternativa a modelos tradicionais, usados para representar o comportamento do motorista em simulação microscópica, considerando-se a representação explícita dos estados mentais dos usuários. Os conceitos básicos de ITS e MAS são apresentados, assim como exemplos de aplicações relacionados com o tema do trabalho. Esta foi a motivação para a extensão de um simulador microscópico existente, no sentido de incorporar as características dos MAS para melhorar a representação dos motoristas. Assim, a demanda é gerada a partir de uma população de agentes, resultando da decisão sobre a rota e o tempo de partida ao longo de vários dias. O modelo estendido, que passa a suportar a interação de motoristas BDI, foi efetivamente implementado e foram executados diferentes experimentos para testar a abordagem em cenários de tráfego urbano. MAS permite uma abordagem direcionada a processos que facilita a construção de representações modulares, robustas, e extensíveis, características pouco presentes em abordagens voltadas ao resultado. Suas premissas de abstração permitem uma associação direta entre modelo e implementação. Incerteza e variabilidade são assim tratadas de maneira mais intuitiva, uma vez que arquiteturas cognitivas permitem uma fácil representação do comportamento humano na estrutura do motorista. Desta forma, MAS estende a simulação microscópica de tráfego no sentido de melhor representar a complexidade inerente às tecnologias ITS. / The rapid growth of urban areas has a significant impact on traffic and transportation systems. New management policies and planning strategies are clearly necessary to cope with the more than ever limited capacity of existing road networks. The concept of Intelligent Transportation System (ITS) arises in this scenario; rather than attempting to increase road capacity by means of physical modifications to the infrastructure, the premise of ITS relies on the use of advanced communication and computer technologies to handle today’s traffic and transportation facilities. Influencing users’ behaviour patterns is a challenge that has stimulated much research in the ITS field, where human factors start gaining great importance to modelling, simulating, and assessing such an innovative approach. This work is aimed at using Multi-agent Systems (MAS) to represent the traffic and transportation systems in the light of the new performance measures brought about by ITS technologies. Agent features have good potentialities to represent those components of a system that are geographically and functionally distributed, such as most components in traffic and transportation. A BDI (beliefs, desires, and intentions) architecture is presented as an alternative to traditional models used to represent the driver behaviour within microscopic simulation allowing for an explicit representation of users’ mental states. Basic concepts of ITS and MAS are presented, as well as some application examples related to the subject. This has motivated the extension of an existing microscopic simulation framework to incorporate MAS features to enhance the representation of drivers. This way demand is generated from a population of agents as the result of their decisions on route and departure time, on a daily basis. The extended simulation model that now supports the interaction of BDI driver agents was effectively implemented, and different experiments were performed to test this approach in commuter scenarios. MAS provides a process-driven approach that fosters the easy construction of modular, robust, and scalable models, characteristics that lack in former result-driven approaches. Its abstraction premises allow for a closer association between the model and its practical implementation. Uncertainty and variability are addressed in a straightforward manner, as an easier representation of humanlike behaviours within the driver structure is provided by cognitive architectures, such as the BDI approach used in this work. This way MAS extends microscopic simulation of traffic to better address the complexity inherent in ITS technologies.

O rápido crescimento das regiões urbanas tem impacto significativo nos sistemas de tráfego e transportes. Políticas de gerenciamento e estratégias de planejamento alternativas são claramente necessárias para o tratamento da capacidade limitada, e cada vez mais deficitária, das redes viárias. O conceito de Sistemas Inteligentes de Transportes (ITS) surge neste cenário; mais do que procurar aumentar a capacidade por meio de modificações físicas na infraestrutura, sua premissa baseia-se na utilização de tecnologias avançadas de comunicação e computação para melhor gerir os recursos de tráfego e transportes atuais. Influenciar o padrão do comportamento dos usuários é um desafio que tem estimulado muita pesquisa na área de ITS, onde fatores humanos passam a ter grande importância na modelagem, simulação e avaliação dessa abordagem inovadora. Este trabalho tem como foco a utilização de Sistemas Multiagentes (MAS) na representação dos sistemas de tráfego e transporte, com base nas novasmedidas de desempenho impostas pelas tecnologias ITS. As características de agentes têm grande potencial para representar componentes geográfica e funcionalmente distribuídos, como a maioria dos elementos no domínio da aplicação. Uma arquitetura BDI (beliefs, desires, intentions) é apresentada como alternativa a modelos tradicionais, usados para representar o comportamento do motorista em simulação microscópica, considerando-se a representação explícita dos estados mentais dos usuários. Os conceitos básicos de ITS e MAS são apresentados, assim como exemplos de aplicações relacionados com o tema do trabalho. Esta foi a motivação para a extensão de um simulador microscópico existente, no sentido de incorporar as características dos MAS para melhorar a representação dos motoristas. Assim, a demanda é gerada a partir de uma população de agentes, resultando da decisão sobre a rota e o tempo de partida ao longo de vários dias. O modelo estendido, que passa a suportar a interação de motoristas BDI, foi efetivamente implementado e foram executados diferentes experimentos para testar a abordagem em cenários de tráfego urbano. MAS permite uma abordagem direcionada a processos que facilita a construção de representações modulares, robustas, e extensíveis, características pouco presentes em abordagens voltadas ao resultado. Suas premissas de abstração permitem uma associação direta entre modelo e implementação. Incerteza e variabilidade são assim tratadas de maneira mais intuitiva, uma vez que arquiteturas cognitivas permitem uma fácil representação do comportamento humano na estrutura do motorista. Desta forma, MAS estende a simulação microscópica de tráfego no sentido de melhor representar a complexidade inerente às tecnologias ITS. / The rapid growth of urban areas has a significant impact on traffic and transportation systems. New management policies and planning strategies are clearly necessary to cope with the more than ever limited capacity of existing road networks. The concept of Intelligent Transportation System (ITS) arises in this scenario; rather than attempting to increase road capacity by means of physical modifications to the infrastructure, the premise of ITS relies on the use of advanced communication and computer technologies to handle today’s traffic and transportation facilities. Influencing users’ behaviour patterns is a challenge that has stimulated much research in the ITS field, where human factors start gaining great importance to modelling, simulating, and assessing such an innovative approach. This work is aimed at using Multi-agent Systems (MAS) to represent the traffic and transportation systems in the light of the new performance measures brought about by ITS technologies. Agent features have good potentialities to represent those components of a system that are geographically and functionally distributed, such as most components in traffic and transportation. A BDI (beliefs, desires, and intentions) architecture is presented as an alternative to traditional models used to represent the driver behaviour within microscopic simulation allowing for an explicit representation of users’ mental states. Basic concepts of ITS and MAS are presented, as well as some application examples related to the subject. This has motivated the extension of an existing microscopic simulation framework to incorporate MAS features to enhance the representation of drivers. This way demand is generated from a population of agents as the result of their decisions on route and departure time, on a daily basis. The extended simulation model that now supports the interaction of BDI driver agents was effectively implemented, and different experiments were performed to test this approach in commuter scenarios. MAS provides a process-driven approach that fosters the easy construction of modular, robust, and scalable models, characteristics that lack in former result-driven approaches. Its abstraction premises allow for a closer association between the model and its practical implementation. Uncertainty and variability are addressed in a straightforward manner, as an easier representation of humanlike behaviours within the driver structure is provided by cognitive architectures, such as the BDI approach used in this work. This way MAS extends microscopic simulation of traffic to better address the complexity inherent in ITS technologies.

Magister Psychologiae - MPsych / HIV and AIDS are disease conditions that have led to high mortality rates in Southern Africa since the late 1970s. The socio-economic system has led to the unequal spread of resources’ and vulnerability and exposure to HIV is more prevalent in poorer communities. The added burden of life stresses cause for many to be isolated and stigmatised and are often not equipped with the necessary support and coping skills to deal with the magnitude of these circumstances. There is a high prevalence of mental disorders and especially depression amongst individuals infected with either HIV or AIDS. Research shows that stressful life events can impact HIV course progression and impacts the QoL of those infected with HIV or AIDS. Given the social and psychological context of HIV and AIDS, the aim of the study was to examine the relationship between depression and QoL in a sample of adults diagnosed with HIV or AIDS. This quantitative, cross-sectional study used the Becks Depression Inventory II (BDI II) and the Quality of Life Enjoyment and Satisfaction Questionnaire (Q-LES-Q), to measure the variables concerned. This battery of questionnaires was administered to a purposive sample of adult individuals diagnosed with HIV or AIDS residing in a previously disadvantaged area in the Cape Metropole region. Using SPSS, data was analysed and descriptive and inferential statistics were conducted. The study found that there were more women than men with HIV or AIDS that were found to be depressed (mild, moderate and severe depression). Furthermore, the depressive state increased when the progression of the disease increased. There were generally no significant differences in the QoL experienced within various areas of life and overall life satisfaction experienced. However, the QoL experienced in work was lower. There was a significant relationship between the depressed state and QoL and life satisfaction experienced in household duties and tasks. The contribution of this study includes informing the larger research project, with regards to future treatment regimes. It will update statistics on the prevalence of depression and QoL of adults diagnosed with HIV or AIDS in the area. This study is framed within a biopsychosocial model and is theoretically underpinned by Beck’s theory of depression. Key words: HIV, AIDS, adults, depression, quality of life (QoL), Beck Depression Inventory II (BDI II), Quality of Life Enjoyment and Satisfaction Questionnaire (Q-LES-Q), Antiretrovirals (ARV’s), prevalence data, correlations. / South Africa

This term project desribes simulator of multiagent system implementation. It explains basic concepts of agent and multiagent systems. Simulator is implemented as a separated object, which allows to join various models of environment and agents acting in this environment. Evaluation of several types of agent cooperation behavior is in last section of this project.

Conventional method of development which repeats phases of design, implementation and testing is not adequate for systems like intelligent agents for which complex behavior is required but specification is unclear at the beginning of development process. Incremental design of agent's model during simulation seems more suitable for it enables direct feedback in behavioral changes of a system. This interactivity speeds up development process and helps to uncover parts of a space of all models to designer - thanks to new knowledge acquired during simulation. This thesis aims to provide comparison of suitability of two agent architectures and respective platforms in context of SmallDEVS modeling and simulation framework for this methodology of development. First approach is reactive and decentralized subsumption architecture based on DEVS formalism and the second one is PNagent, framework realizing deliberative BDI architecture using Object Oriented Petri Nets.

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Made available in DSpace on 2016-03-22T17:26:22Z (GMT). No. of bitstreams: 1 dm2_Luciano_vargas.pdf: 637463 bytes, checksum: b08b63e8c6a347cd2c86fc24fdfd8986 (MD5) Previous issue date: 2009-03-31 / The study and development of systems to control interactions in multiagent systems is an open problem in Artificial Intelligence. The system of social exchange values of Piaget is a social approach that allows for the foundations of the modeling of interactions between agents, where the interactions are seen as service exchanges between pairs of agents, with the evaluation of the realized or received services, thats is, the investments and profits in the exchange, and credits and debits to be charged or received, respectively, in future exchanges. This evaluation may be performed in different ways by the agents, considering that they may have different exchange personality traits. In an exchange process along the time, the different ways in the evaluation of profits and losses may cause disequilibrium in the exchange balances, where some agents may accumulate profits and others accumulate losses. To solve the exchange equilibrium problem, we use the Partially Observable Markov Decision Processes (POMDP) to help the agent decision of actions that can lead to the equilibrium of the social exchanges. Then, each agent has its own internal process to evaluate its current balance of the results of the exchange process between the other agents, observing its internal state, and with the observation of its partner s exchange behavior, it is able to deliberate on the best action it should perform in order to get the equilibrium of the exchanges. Considering an open multiagent system, it is necessary a mechanism to recognize the different personality traits, to build the POMDPs to manage the exchanges between the pairs of agents. This recognizing task is done by Hidden Markov Models (HMM), which, from models of known personality traits, can approximate the personality traits of the new partners, just by analyzing observations done on the agent behaviors in exchanges. The aim of this work is to develop an hybrid agent architecture for the self-regulation of social exchanges between personalitybased agents in a open multiagent system, based in the BDI (Beliefs, Desires, Intentions) architecture, where the agent plans are obtained from optimal policies of POMDPs, which model personality traits that are recognized by HMMs. To evaluate the proposed approach some simulations were done considering (known or new) different personality traits / O estudo e desenvolvimento de sistemas para o controle de interações em sistemas multiagentes é um tema em aberto dentro da Inteligência Artificial. O sistema de valores de trocas sociais de Piaget é uma abordagem social que possibilita fundamentar a modelagem de interações de agentes, onde as interações são vistas como trocas de serviços entre pares de agentes, com a valorização dos serviços realizados e recebidos, ou seja, investimentos e ganhos na troca realizada, e, também os créditos e débitos a serem cobrados ou recebidos, respectivamente, em trocas futuras. Esta avaliação pode ser realizada de maneira diferenciada pelos agentes envolvidos, considerando que estes apresentam traços de personalidade distintos. No decorrer de processo de trocas sociais a forma diferenciada de avaliar os ganhos e perdas nas interações pode causar desequilíbrio nos balanços de trocas dos agentes, onde alguns agentes acumulam ganhos e outros acumulam perdas. Para resolver a questão do equilíbrio das trocas, encontrou-se nos Processos de Decisão de Markov Parcialmente Observáveis (POMDP) uma metodologia capaz de auxiliar a tomada de decisões de cursos de ações na busca do equilíbrio interno dos agentes. Assim, cada agente conta com um mecanismo próprio para avaliar o seu estado interno, e, de posse das observações sobre o comportamento de troca dos parceiros, torna-se apto para deliberar sobre as melhores ações a seguir na busca do equilíbrio interno para o par de agentes. Com objetivo de operar em sistema multiagentes aberto, torna-se necessário um mecanismo para reconhecer os diferentes traços de personalidade, viabilizando o uso de POMDPs nestes ambientes. Esta tarefa de reconhecimento é desempenhada pelos Modelos de Estados Ocultos de Markov (HMM), que, a partir de modelos de traços de personalidade conhecidos, podem inferir os traços aproximados de novos parceiros de interações, através das observações sobre seus comportamentos nas trocas. O objetivo deste trabalho é desenvolver uma arquitetura de agentes híbrida para a auto-regulação de trocas sociais entre agentes baseados em traços de personalidade em sistemas multiagentes abertos. A arquitetura proposta é baseada na arquitetura BDI (Beliefs, Desires, Intentions), onde os planos dos agentes são obtidos através de políticas ótimas de POMDPs, que modelam traços de personalidade reconhecidos através de HMMs. Para avaliar a proposta, foram realizadas simulações envolvendo traços de personalidade conhecidos e novos traços

Psychologist and bariatric tretment of obesity PhDr.Jitka Herlesová Tutor: PhDr.Tamara Hrachovinová, CSc. Abstract The aim of the dissertation thesis is to map psychosocial characteristics associated with obesity and their changes after bariatric surgery. The Empirical part follows the points settled in the Theoretical part. Obesity is a disease, whose prevalence rises. Bariatric and metabolic surgery is one of the most effective treatment of obesity and its comorbidities. The mental diseases are associated with high levels of obesity. The standard part of pre-bariatric examination is the psychological assessment. Several changes accompany the weight loss after bariatric surgery, such as normalization of psychosocial functioning, the decrease of mental disorders but in some cases the changes might be also negative. The Empirical part focuses on the psychosocial characteristics of bariatric surgery candidates assessed during the psychological evaluation and the changes after operation. The data from semi-structured psychological interview, Three factor eating questionnaire, Beck Depression Inventory-II, Obesity Weight Loss Quality of Life and Weight Related Symptom Measure were evaluated. The changes after surgery were assessed after 6, 12 and 24 months. Statistically significant differences were ascertained...

This dissertation investigates high-level decision making for agents that are both goal and utility driven. We develop a partially observable Markov decision process (POMDP) planner which is an extension of an agent programming language called DTGolog, itself an extension of the Golog language. Golog is based on a logic for reasoning about action—the situation calculus. A POMDP planner on its own cannot cope well with dynamically changing environments and complicated goals. This is exactly a strength of the belief-desire-intention (BDI) model: BDI theory has been developed to design agents that can select goals intelligently, dynamically abandon and adopt new goals, and yet commit to intentions for achieving goals. The contribution of this research is twofold: (1) developing a relational POMDP planner for cognitive robotics, (2) specifying a preliminary BDI architecture that can deal with stochasticity in action and perception, by employing the planner. / Computing / M. Sc. (Computer Science)

Magister Psychologiae - MPsych / This study utilised secondary data from a larger study that looked at individuals that are already infected by HIV which is entitled Implicative personal dilemmas and cognitive conflicts in health decision making in HIV positive adults and adults with AIDS. The primary aim of the larger study was to examine the cognitive construction of the individual and how they utilised their individual resources to construct who they are and how they perceived the difficulties and challenges that they face and the decisions they make regarding their health. HIV and AIDS is a debilitating disease and it affects millions worldwide. South Africa, presently, has the largest burden of this disease with those between the ages of 15 – 49 years of age being most affected. As previously mentioned the decisions that individuals make can impact on their health. Decisions to take necessary precautions such as protected sex during sexual intercourse can decrease the progression of the disease. Decisions made regarding abstinence of risky behaviour as well as being committed to taking medication could also positively impact health. People living with HIV and AIDS find it difficult to adjust to the challenges that this disease presents. Depression is often experienced due to the changes in self image and perception. Studies show that females are twice more likely to experience depression than men. There has however been no conclusive evidence showing the reason for this, however, the perception of stress based on gender could shed some light on this matter and how these perceptions can increase the likelihood of women being more vulnerable to depression. Due to the limitation of this study, it will only look at depression as it relates to HIV and AIDS. Psychological problems such as depression can hamper the adjustment process and the effect of depression is evident in that it can lower the CD 4 + cells. Not only are those living with HIV and AIDS affected by depression, but they also have a lifetime prevalence to depression. It is important to have an effective screening tool for depression so that the detection of this disease can be made and effective treatment can be implemented to enhance health. The sample consisted of 113 adult participants that have already been diagnosed with HIV and AIDS. The primary aim of this study was to compare the Beck’s Depression Inventory II (BDI II) and the Hospital Anxiety and Depression Scale –(the Depression component) (HADS-D) as a screening tool for depression. Exploratory Factor Analysis revealed a 5 factor structure which accounted for 60.14 % of the total variance. The HADS yielded one factor accounting for 14.33% of total variance. The BDI II has proven to be more a reliable measure of depression with 0.89 according to the Cronbach’s Alpha co efficient opposed to 0.375 as per the HADS-D. The secondary aim was to establish the sociodemographic and disease profiles of the participants under study. / South Africa