Stuttgart, University, Diss., 1999.

München, University der Bundeswehr, Diss., 2004.

Stuttgart, Universiẗat, Diss., 2002.

Stuttgart, Universiẗat, Diss., 2002.

Universiẗat, Diss., 1999--Freiburg (Breisgau).

Sharing common goals and acting cooperatively are critical issues in multiagent teamwork. Traditionally, agents cooperate with each other by inferring others' actions implicitly or explicitly, based on established norms for behavior or on knowledge about the preferences or interests of others. This kind of cooperation either requires that agents share a large amount of knowledge about the teamwork, which is unrealistic in a distributed team, or requires high-frequency message exchange, which weakens teamwork efficiency, especially for a team that may involve human members. In this research, we designed and developed a new approach called Proactive Communication, which helps to produce realistic behavior and interactions for multiagent teamwork. We emphasize that multi-agent teamwork is governed by the same principles that underlie human cooperation. Psychological studies of human teamwork have shown that members of an effective team often anticipate the needs of other members and choose to assist them proactively. Human team members are also naturally capable of observing the environment and others so they can establish certain parameters for performing actions without communicating with others. Proactive Communication endows agents with observabilities and enables agents use them to track others’ mental states. Additionally, Proactive Communication uses statistical analysis of the information production and need of team members and uses these data to capture the complex, interdependent decision processes between information needer and provider. Since not all these data are known, we use their expected values with respect to a dynamic estimation of distributions. The approach was evaluated by running several sets of experiments on a Multi- Agent Wumpus World application. The results showed that endowing agents with observability decreased communication load as well as enhanced team performance. The results also showed that with the support of dynamic distributions, estimation, and decision-theoretic modeling, teamwork efficiency were improved.

Debugging multi-agent systems, which are concurrent, distributed, and consist of complex components is difficult, yet crucial. The development of these complex systems is supported by agent-oriented software engineering methodologies which utilise agents as the central design metaphor. The systems that are developed are inherently complex since the components of these systems may interact in flexible and sophisticated ways and traditional debugging techniques are not appropriate. Despite this, very little effort has been applied to developing appropriate debugging tools and techniques. Debugging multi-agent systems without good debugging tools is highly impractical and without suitable debugging support developing and maintaining multi-agent systems will be more difficult than it need be. In this thesis we propose that the debugging process can be supported by following an agent-oriented design methodology, and then using the developed design artifacts in the debugging phase. We propose a domain independent debugging framework which comprises the developed processes and components that are necessary in using design artifacts as debugging artifacts. Our approach is to take a non-formal design artifact, such as an AUML protocol design, and encode it in a machine interpretable manner such that the design can be used as a model of correct system behaviour. These models are used by a run-time debugging system to compare observed behaviour against specified behaviour. We provide details for transforming two design artifact types into equivalent debugging artifacts and show how these can be used to detect bugs. During a debugging episode in which a bug has been identified our debugging approach can provide detailed information about the possible reason for the bug occurring. To determine if this information was useful in helping to debug programs we undertook a thorough empirical study and identified that use of the debugging tool translated to an improvement in debugging performance. We conclude that the debugging techniques developed in this thesis provide effective debugging support for multi-agent systems and by having an extensible framework new design artifacts can be explored and as translations are developed they can be added to the debugging system.

La durabilité des bétons est grandement affectée par la fissuration due au retrait (endogène et retrait empêché) et elle nécessite donc, une attention particulière. Le retrait empêché du béton engendre des contraintes de traction, responsables de la formation de microfissures voire des fissures traversantes qui permettent la pénétration des agents agressifs et une augmentation de la perméabilité. Pour maximiser la durabilité des bétons, il est essentiel d’éviter la formation des fissures dans les ouvrages en service. L’objectif global de la recherche est de développer une approche de formulation des bétons à retrait compensé pour éviter la formation de fissures. Cette approche de formulation est basée sur l’utilisation combinée d’un agent d’expansion interne et d’un agent réducteur de retrait. Ce projet de recherche a pour but d’étudier l’influence d’un agent d’expansion interne et d’un agent réducteur de retrait sur les variations volumiques libres et restreintes du béton. Trois méthodes (ASTM C878; ASTM C157; Capteurs à cordes vibrantes) sont utilisées avec différents pourcentages en agent d’expansion interne (0%, 3%, 6%, 10%) et 2% d’agent réducteur de retrait (ARR) pour évaluer les variations volumiques du béton. Cette étude est menée en deux phases pour analyser les variations volumiques libres (ASTM C157; Capteurs à cordes vibrantes) et restreintes (ASTM C878) du béton ainsi que l’influence de ces deux adjuvants combinés sur le retrait. La première phase consiste à étudier les variations volumiques libres et restreintes du béton avec l’agent d’expansion interne (Conex) et son influence sur le retrait (retrait total et retrait de séchage). La deuxième phase consiste à étudier l’influence de l’agent réducteur de retrait (ARR) sur les variations volumiques libres et restreintes, sur le retrait de séchage du béton contenant l’agent d’expansion interne (Conex). Un total de 16 formulations de béton de 25 MPa sans air entrainé a été étudié en laboratoire. L’analyse des bétons formulés avec différents pourcentages en agent d’expansion montre que les expansions libres et restreintes augmentent en fonction du dosage en Conex. L’expansion initiale créée (0 - 7 jours) par le Conex produit un retrait total faible par rapport au béton sans Conex et la diminution du retrait total est fonction de l’augmentation du dosage en Conex. L’ajout de l’agent réducteur de retrait (ARR) produit une diminution du retrait de séchage de 40% à 7 jours et de 30% à 224 jours. Le retrait total diminue de 72% à 7 jours et 43% à 224 jours. Les données expérimentales montrent qu’en plus de la diminution du retrait, on peut produire un béton à retrait compensé avec un dosage optimal de 3% Conex + 2% ARR. La formulation d’un béton à faible retrait par l’utilisation du Conex et ARR permet de réduire les risques de fissurations, d’améliorer la qualité du béton et de contrecarrer le retrait empêché. Les investigations menées dans ce mémoire permettent d’enrichir les connaissances sur les différents adjuvants utilisés (Conex et ARR), leurs influences sur le béton, principalement la diminution du retrait de séchage et d’évaluer un pourcentage optimal pour un béton sans retrait, donc plus durable.

The popularity of Craigslist has enabled users worldwide to find almost any product at prices significantly less than retail prices or market-prices. Craigslist has thus enabled lot of resellers to enter the market and has created a huge market for used/pre-owned products. The key to find products at prices less than their market-prices is to find the right classified and act immediately before other users. Craigslist search agents, with ability to search classifieds, that run on mobile/handheld devices are increasing in popularity with ubiquitous internet connectivity, convenience and speed. AnveShA is an automatic search and monitoring agent for craigslist that has been developed for Android platforms. AnveShA provides easy access and a rich feature-set that is not available in the state-of-the-art craigslist search applications available on the Android market. AnveShA has been developed to provide the user a rapid and intelligent search agent that can proactively search and monitor classifieds for desired products, contact sellers and increase the chances of obtaining the desired product at the best possible price. To achieve this, AnveShA has many unique features like the ability to schedule and execute automatic searches, search classifieds based on geographical location, automatically respond to classifieds, store price history for classifieds, get comparative prices from other retail/shopping websites, store favorite classifieds/reminder lists and predict the offer price based on a number of parameters. With such unique features, AnveSha assists users or resellers to find desired products at the best possible prices on Craigslist and hence have a significant advantage over the competition. / text

Title: Exogenous factors selected for the development of football talent Targets: The aim of this study was to characterize selected exogenous factors influencing the development of football talent. Find out how and how much these factors influence the football talents in the Czech Republic. Methods: In the work was used qualitative research. Structured interview method was applied to obtain information from agents and football coaches of youth teams. The questionnaire method with open questions was applied to the football talent and stakeholders of football grounds. Comparison method was used to compare the information. Results: The results summarize the degree of influence and share of each factor in the development of football talent in the Czech Republic. Results from questionnaires and interviews are presented in a written summary and presented in the same order in which questions were asked. Keywords: Talent, football, football agent