One of the limitations of the BDI (Belief-Desire-Intention) model is the lack of any explicit mechanisms within the architecture to be able to learn. In particular, BDI agents do not possess the ability to adapt based on past experience. This is important in dynamic environments as they can change, causing previously successful methods for achieving goals to become inefficient or ineffective. We present a model in which learning, analogous reasoning, data pruning and learner accuracy evaluation can be utilised by a BDI agent and verify this model experimentally using Inductive and Statistical learning. Intelligent Agents are a new way of developing software applications. They are an amalgam of Artificial Intelligence (AI) and Software Engineering concepts that are highly suited to domains that are inherently complex and dynamic. Agents are software entities that are autonomous, reactive, proactive, situated and social. They are autonomous in that they are able to make decisions on their own volition. They are situated in some environment and are reactive to this environment yet are also capable of proactive behaviour where they actively pursue goals. They are capable of social behaviour where communication can occur between agents. BDI (Belief Desire Intention) agents are one popular type of agent that support complex behaviour in dynamic environments. Agent adaptation can be viewed as the process of changing the way in which an agent achieves its goals. We distinguish between 'reactive' or short-term adaptation, 'long-term' or historical adaptation and 'very long term' or evolutionary adaptation. Short-term adaptation, an ability that current BDI agents already possess, involves reacting to changes in the environment and choosing alternative plans of action which may involve choosing new plans if the current plan fails. 'Long-term' or historical adaptation entails the use of past cases during the reasoning process which enables agents to avoid repeating past mistak es. 'Evolutionary adaptation' could involve the use of genetic programming or similar techniques to mutate plans to lead to altered behaviour. Our work aims to improve BDI agents by introducing a framework that allows BDI agents to alter their behaviour based on past experience, i.e. to learn.

Um dos problemas do paradigma BDI quando se integram agentes a ambientes virtuais ou simuladores é a ausência de controle sobre as suas percepções. Não havendo alguma forma de percepção direcionada ao objetivo, o agente pode ser inundado por informações irrelevantes causando um aumento injustificado do tempo de processamento. Com o objetivo de fornecer um maior controle sobre as percepções do agente e reduzir o seu tempo de resposta, este trabalho apresenta um mecanismo de filtragem das percepções para o interpretador Jason que visa eliminar aquelas percepções que podem ser ignoradas. Para tal, foram propostos e implementados alguns tipos de filtros pré-definidos, que foram aplicados a três cenários diferentes. Através de validações estatísticas apropriadas, mostrou-se que a aplicação de filtros de percepção pode reduzir em até 80% o tempo de processamento de um agente, sem afetar significativamente o seu desempenho medido em termos de sua função de utilidade. / When agents are supposed to be integrated to virtual environments virtual or simulators, one of the BDI paradigms major concerns is the lack of control over the agents perceptions. Without having any form of goal directed perceptions, the agent may be flooded by irrelevant information thus causing an unjustified increase in processing time. In order to provide greater control on the agents perceptions and to reduce its time response, this work presents a filtering perception mechanism for the Jason interpreter, aimed at eliminating those perceptions that can be ignored. To this end, some types of pre-defined filters have been proposed, implemented, and applied to three different scenarios. Through appropriate statistical validation methods, it was shown that applying perception filters can reduce up to 80 % of an agents processing time, without significantly affecting its performance measured in terms of its utility function.

Um dos problemas do paradigma BDI quando se integram agentes a ambientes virtuais ou simuladores é a ausência de controle sobre as suas percepções. Não havendo alguma forma de percepção direcionada ao objetivo, o agente pode ser inundado por informações irrelevantes causando um aumento injustificado do tempo de processamento. Com o objetivo de fornecer um maior controle sobre as percepções do agente e reduzir o seu tempo de resposta, este trabalho apresenta um mecanismo de filtragem das percepções para o interpretador Jason que visa eliminar aquelas percepções que podem ser ignoradas. Para tal, foram propostos e implementados alguns tipos de filtros pré-definidos, que foram aplicados a três cenários diferentes. Através de validações estatísticas apropriadas, mostrou-se que a aplicação de filtros de percepção pode reduzir em até 80% o tempo de processamento de um agente, sem afetar significativamente o seu desempenho medido em termos de sua função de utilidade. / When agents are supposed to be integrated to virtual environments virtual or simulators, one of the BDI paradigms major concerns is the lack of control over the agents perceptions. Without having any form of goal directed perceptions, the agent may be flooded by irrelevant information thus causing an unjustified increase in processing time. In order to provide greater control on the agents perceptions and to reduce its time response, this work presents a filtering perception mechanism for the Jason interpreter, aimed at eliminating those perceptions that can be ignored. To this end, some types of pre-defined filters have been proposed, implemented, and applied to three different scenarios. Through appropriate statistical validation methods, it was shown that applying perception filters can reduce up to 80 % of an agents processing time, without significantly affecting its performance measured in terms of its utility function.

We investigate the problem of developing a formal language for specifying and reasoning about real-time embedded distributed computer systems. In particular we investigate the problem of developing a theoretical framework for specifying and analyzing different aspects of real-time embedded distributed coordination. In addition to the theoretical framework we also consider the practical aspects of developing real-time embedded distributed systems. (For complete abstract open document)

Le résumé en français n'a pas été communiqué par l'auteur. / Le résumé en anglais n'a pas été communiqué par l'auteur.

Pensando nas milhoes de pessoas que sao afetadas mundialmente pelos transtornos depressivos (322 milhoes, sendo mais de 11 milhoes no Brasil e quase 450 mil na Suecia), tentamos criar um instrumento para avaliar depressao de forma mais eficaz. Em geral, os transtornos depressivos sao caracterizados por tristeza, perda de interesse/prazer, sentimentos de culpa ou baixa autoestima, disturbios no sono e apetite, sentimentos de cansaco, e baixa concentracao. Alem dos criterios diagnosticos, diversos instrumentos avaliam quadros depressivos. Utilizamos o Inventario de Depressao de Beck para validar a Escala CR100 de BorgR para o escalonamento de sintomas depressivos. As Escalas de Borg comecaram a ser desenvolvidas na decada de 60 para avaliacao do esforco percebido. A CR100 e uma escala de 0 a 100, com categorias verbais posicionadas de acordo com uma escala numerica gerando dados de razao. Esse tipo de escala tem diversas vantagens, como permitir a comparacao entre e dentre sujeitos e grupos, criacao de perfis de sintomas, analise de sintomas individualmente e a razao de intensidade entre eles. Essa tese consta de tres artigos usando a CR100. O Estudo I investigou as propriedades da CR100 comparada ao BDI. Cinquenta estudantes de Psicologia suecos responderam a um questionario online e os resultados mostraram uma alta correlacao entre as duas escalas (r = 0.754, p < 0.001), demonstrando que a Escala de BorgR avalia depressao tao bem quanto o BDI, entretanto fornece mais resultados. O perfil de sintomas gerado e muito mais detalhado do que o BDI, alem dos dados serem mais precisos e nao serem tao sensiveis as transformacoes matematicas. O Estudo II trata-se da validacao da CR100 para o portugues brasileiro e tal qual o Estudo I, da aplicacao em 50 estudantes brasileiros. Os resultados tambem apontam a alta correlacao entre as escalas (r = 0.824, p<0,001) com todas as caracteristicas se mantendo em ambas as nacionalidades A primeira analise de confiabilidade revelou um alto valor de alfa (entre 0.952 e 0.947) e R2 (entre 0.778 e 0.976), maiores que o BDI. O Estudo III teve como principal objetivo investigar propriedades psicometricas da CR100 em participantes depressivos (N=25) e - 10 - saudaveis (N=25), e encontrar pontos de corte para depressao leve, media e severa. A analise de confiabilidade da Escala revelou um indice alpha de 0.954 e por meio de uma reducao fatorial, os 32 itens foram agrupados em sete componentes. Tambem foi possivel construir um perfil de sintomas entre as duas populacoes corroborando a sensibilidade da CR100 em diferenciar populacao saudavel e com depressao em um intervalo de confianca de 95%. Um indice da razao entre pacientes e sujeitos saudaveis pode ser criado, gerando uma mini escala com oito itens, com um valor alpha de 0.80, e correlacao com a escala completa de r = 0.915 (p <0.001) e com o BDI de r = 0.820 (p<0,001). Os tres estudos revelaram resultados satisfatorios que vao ao encontro do que ja foi corroborado pelas pesquisas com as Escalas de BorgR. Demonstrou-se tambem ser possivel fazer o uso da CR100 para avaliar sintomas depressivos com mais informacoes e cujos dados sao mais precisos do que os instrumentos analisados / Thinking about the millions of people who are affected worldwide by depressive disorders (322 million, more than 11 million in Brazil and almost 450.000 in Sweden), we tried to create an instrument to assess depression more effectively. In general, depressive disorders are characterized by sadness, loss of interest/pleasure, feelings of guilt or low self-esteem, changes in sleep and appetite, tiredness, and low concentration. In addition to the diagnostic criteria, several instruments evaluate depressive disorders. We used the Beck Depression Inventory to validate the Borg CR100 ScaleR for scaling depressive symptoms. The Borg ScalesR were developed in the 60\'s for the evaluation of perceived exertion. The CR100 is a scale from 0 to 100, with verbal categories placed in agreement with the numerical scale so as to obtain ratio data. This type of scale has several advantages, such as allowing comparison between and within subjects and groups, creating symptoms profile, analyzing individual symptoms and the intensity ratio between them. This thesis consists of three papers using the CR100. Study #1 investigated the properties of CR100 compared to BDI. Fifty Swedish students of Psychology answered an online questionnaire and the results pointed a high correlation between the two scales (r = 0.754, p <0.001), demonstrating that the Borg Scale evaluates depression as well as the BDI, providing more results though. The symptom profile generated was much more detailed than the BDI, in addition, the data was more accurate and not that sensitive to mathematical transformations. Study #2 looked after the validation of CR100 for Brazilian Portuguese and, like #1, the application in 50 Brazilian students. The results also pointed to the high correlation between the scales (r = 0.824, p <0.001) with all characteristics preserved in both nationalities. The first reliability analysis revealed a high alpha value (between 0.952 and 0.947) and R2 (between 0.778 and 0.976), higher than the BDI. The aim of Study #3 was to investigate the psychometric properties of CR100 in depressive (N = 25) and healthy participants (N = 25), and to find cutoff points for light, medium and severe depression. The reliability analysis of the Scale revealed an alpha of 0.954 and by running a factorial reduction, - 12 - the 32 items were grouped into seven components. It was also possible to construct a profile of symptoms between the two populations verifying the sensitivity of CR100 to differentiate healthy from depressive population, in a 95% confidence interval. An index of the ratio between patients and healthy subjects could be created, generating a mini scale with eight items with an alpha value of 0.80 and correlation with the full scale of r = 0.915 (p <0.001) and with the BDI of r = 0.820 (p <0.001). The three studies have shown satisfactory results that match with what has already been demonstrated by researches with the Borg ScalesR. It has also been presented the possibility of using the CR100 to assess depressive symptoms with more information and which data are more accurate than the instruments analyzed

Made available in DSpace on 2016-07-27T14:22:21Z (GMT). No. of bitstreams: 1 ADRIANA VEROLLA DE MOURA.pdf: 423562 bytes, checksum: 8041feec2eeae4f5fa4730ba13c0804d (MD5) Previous issue date: 2010-10-28 / O presente trabalho encontra-se dividido em dois artigos. O primeiro artigo, define infertilidade, suas causas e tratamentos atualmente disponíveis e analisa aspectos emocionais do paciente infértil em tratamento. As alterações psicológicas mais associadas nesses pacientes são a ansiedade e depressão e alguns aspectos tem sido identificados como influenciadores no surgimento desses transtornos. São abordados no artigo entre outros, o tempo de tratamento, expectativas dos pacientes em relação às probabilidades de sucesso, diferenças entre sexos na experiência da infertilidade, a existência ou não de uma rede de apoio provendo suporte social e diferenças culturais. Relações entre estes aspectos são realizadas e sugestões feitas para novas pesquisas na área. O segundo artigo apresentado relaciona o tratamento da infertilidade com duas alterações psicológicas, depressão e ansiedade, analisando a importância do suporte social para diminuição da severidade dos sintomas. Através da aplicação de três instrumentos, Inventário de Depressão de Beck (BDI), Inventário de Ansiedade de Beck (BAI) e Escala de Suporte Social, os níveis de depressão, ansiedade e suporte social foram acessados numa amostra de 148 sujeitos em tratamento para infertilidade. Correlacionando os dados dos três testes aplicados encontramos uma correlação significativa apenas entre os testes da Escala de Beck. Hipóteses para os achados são desenvolvidas no artigo empírico.

Rational agent behaviour is frequently achieved through the use of plans, particularly within the widely used BDI (Belief-Desire-Intention) model for intelligent agents. As a consequence, preventing or handling failure of planned activity is a vital component in building robust multiagent systems; this is especially true in realistic environments, where unpredictable exogenous change during plan execution may threaten intended activities. Although reactive approaches can be employed to respond to activity failure through replanning or plan-repair, failure may have debilitative effects that act to stymie recovery and, potentially, hinder subsequent activity. A further factor is that BDI agents typically employ deterministic world and plan models, as probabilistic planning methods are typical intractable in realistically complex environments. However, deterministic operator preconditions may fail to represent world states which increase the risk of activity failure. The primary contribution of this thesis is the algorithmic design of the CAMP-BDI (Capability Aware, Maintaining Plans) approach; a modification of the BDI reasoning cycle which provides agents with beliefs and introspective reasoning to anticipate increased risk of failure and pro-actively modify intended plans in response. We define a capability meta-knowledge model, providing information to identify and address threats to activity success using precondition modelling and quantitative quality estimation. This also facilitates semantic-independent communication of capability information for general advertisement and of dependency information - we define use of the latter, within a structured messaging approach, to extend local agent algorithms towards decentralized, distributed robustness. Finally, we define a policy based approach for dynamic modification of maintenance behaviour, allowing response to observations made during runtime and with potential to improve re-usability of agents in alternate environments. An implementation of CAMP-BDI is compared against an equivalent reactive system through experimentation in multiple perturbation configurations, using a logistics domain. Our empirical evaluation indicates CAMP-BDI has significant benefit if activity failure carries a strong risk of debilitative consequence.

Pensando nas milhoes de pessoas que sao afetadas mundialmente pelos transtornos depressivos (322 milhoes, sendo mais de 11 milhoes no Brasil e quase 450 mil na Suecia), tentamos criar um instrumento para avaliar depressao de forma mais eficaz. Em geral, os transtornos depressivos sao caracterizados por tristeza, perda de interesse/prazer, sentimentos de culpa ou baixa autoestima, disturbios no sono e apetite, sentimentos de cansaco, e baixa concentracao. Alem dos criterios diagnosticos, diversos instrumentos avaliam quadros depressivos. Utilizamos o Inventario de Depressao de Beck para validar a Escala CR100 de BorgR para o escalonamento de sintomas depressivos. As Escalas de Borg comecaram a ser desenvolvidas na decada de 60 para avaliacao do esforco percebido. A CR100 e uma escala de 0 a 100, com categorias verbais posicionadas de acordo com uma escala numerica gerando dados de razao. Esse tipo de escala tem diversas vantagens, como permitir a comparacao entre e dentre sujeitos e grupos, criacao de perfis de sintomas, analise de sintomas individualmente e a razao de intensidade entre eles. Essa tese consta de tres artigos usando a CR100. O Estudo I investigou as propriedades da CR100 comparada ao BDI. Cinquenta estudantes de Psicologia suecos responderam a um questionario online e os resultados mostraram uma alta correlacao entre as duas escalas (r = 0.754, p < 0.001), demonstrando que a Escala de BorgR avalia depressao tao bem quanto o BDI, entretanto fornece mais resultados. O perfil de sintomas gerado e muito mais detalhado do que o BDI, alem dos dados serem mais precisos e nao serem tao sensiveis as transformacoes matematicas. O Estudo II trata-se da validacao da CR100 para o portugues brasileiro e tal qual o Estudo I, da aplicacao em 50 estudantes brasileiros. Os resultados tambem apontam a alta correlacao entre as escalas (r = 0.824, p<0,001) com todas as caracteristicas se mantendo em ambas as nacionalidades A primeira analise de confiabilidade revelou um alto valor de alfa (entre 0.952 e 0.947) e R2 (entre 0.778 e 0.976), maiores que o BDI. O Estudo III teve como principal objetivo investigar propriedades psicometricas da CR100 em participantes depressivos (N=25) e - 10 - saudaveis (N=25), e encontrar pontos de corte para depressao leve, media e severa. A analise de confiabilidade da Escala revelou um indice alpha de 0.954 e por meio de uma reducao fatorial, os 32 itens foram agrupados em sete componentes. Tambem foi possivel construir um perfil de sintomas entre as duas populacoes corroborando a sensibilidade da CR100 em diferenciar populacao saudavel e com depressao em um intervalo de confianca de 95%. Um indice da razao entre pacientes e sujeitos saudaveis pode ser criado, gerando uma mini escala com oito itens, com um valor alpha de 0.80, e correlacao com a escala completa de r = 0.915 (p <0.001) e com o BDI de r = 0.820 (p<0,001). Os tres estudos revelaram resultados satisfatorios que vao ao encontro do que ja foi corroborado pelas pesquisas com as Escalas de BorgR. Demonstrou-se tambem ser possivel fazer o uso da CR100 para avaliar sintomas depressivos com mais informacoes e cujos dados sao mais precisos do que os instrumentos analisados / Thinking about the millions of people who are affected worldwide by depressive disorders (322 million, more than 11 million in Brazil and almost 450.000 in Sweden), we tried to create an instrument to assess depression more effectively. In general, depressive disorders are characterized by sadness, loss of interest/pleasure, feelings of guilt or low self-esteem, changes in sleep and appetite, tiredness, and low concentration. In addition to the diagnostic criteria, several instruments evaluate depressive disorders. We used the Beck Depression Inventory to validate the Borg CR100 ScaleR for scaling depressive symptoms. The Borg ScalesR were developed in the 60\'s for the evaluation of perceived exertion. The CR100 is a scale from 0 to 100, with verbal categories placed in agreement with the numerical scale so as to obtain ratio data. This type of scale has several advantages, such as allowing comparison between and within subjects and groups, creating symptoms profile, analyzing individual symptoms and the intensity ratio between them. This thesis consists of three papers using the CR100. Study #1 investigated the properties of CR100 compared to BDI. Fifty Swedish students of Psychology answered an online questionnaire and the results pointed a high correlation between the two scales (r = 0.754, p <0.001), demonstrating that the Borg Scale evaluates depression as well as the BDI, providing more results though. The symptom profile generated was much more detailed than the BDI, in addition, the data was more accurate and not that sensitive to mathematical transformations. Study #2 looked after the validation of CR100 for Brazilian Portuguese and, like #1, the application in 50 Brazilian students. The results also pointed to the high correlation between the scales (r = 0.824, p <0.001) with all characteristics preserved in both nationalities. The first reliability analysis revealed a high alpha value (between 0.952 and 0.947) and R2 (between 0.778 and 0.976), higher than the BDI. The aim of Study #3 was to investigate the psychometric properties of CR100 in depressive (N = 25) and healthy participants (N = 25), and to find cutoff points for light, medium and severe depression. The reliability analysis of the Scale revealed an alpha of 0.954 and by running a factorial reduction, - 12 - the 32 items were grouped into seven components. It was also possible to construct a profile of symptoms between the two populations verifying the sensitivity of CR100 to differentiate healthy from depressive population, in a 95% confidence interval. An index of the ratio between patients and healthy subjects could be created, generating a mini scale with eight items with an alpha value of 0.80 and correlation with the full scale of r = 0.915 (p <0.001) and with the BDI of r = 0.820 (p <0.001). The three studies have shown satisfactory results that match with what has already been demonstrated by researches with the Borg ScalesR. It has also been presented the possibility of using the CR100 to assess depressive symptoms with more information and which data are more accurate than the instruments analyzed

GDP and GDP per capita are widely used to gauge for living standards across countries. However, they have originally not been constructed for this purpose and are therefore subject to significant limitations. This paper aims at developing a better and non-monetary development index with which cross-country living standards can be assessed. This index, the BDI, can then be utilized for policy making. When constructing the BDI, this study utilizes time series analysis and panel unit root tests. A major finding of this study is that the BDI does indeed produce statistically significantly different results/ rankings for a special set of countries, compared to GDP and GDP per capita.