Real-Time Strategy (RTS) is a sub-genre of strategy games which is running in real-time, typically in a war setting. The player uses workers to gather resources, which in turn are used for creating new buildings, training combat units, build upgrades and do research. The game is won when all buildings of the opponent(s) have been destroyed. The numerous tasks that need to be handled in real-time can be very demanding for a player. Computer players (bots) for RTS games face the same challenges, and also have to navigate units in highly dynamic game worlds and deal with other low-level tasks such as attacking enemy units within fire range. This thesis is a compilation grouped into three parts. The first part deals with navigation in dynamic game worlds which can be a complex and resource demanding task. Typically it is solved by using pathfinding algorithms. We investigate an alternative approach based on Artificial Potential Fields and show how an APF based navigation system can be used without any need of pathfinding algorithms. In RTS games players usually have a limited visibility of the game world, known as Fog of War. Bots on the other hand often have complete visibility to aid the AI in making better decisions. We show that a Multi-Agent PF based bot with limited visibility can match and even surpass bots with complete visibility in some RTS scenarios. We also show how the bot can be extended and used in a full RTS scenario with base building and unit construction. In the next section we propose a flexible and expandable RTS game architecture that can be modified at several levels of abstraction to test different techniques and ideas. The proposed architecture is implemented in the famous RTS game StarCraft, and we show how the high-level architecture goals of flexibility and expandability can be achieved. In the last section we present two studies related to gameplay experience in RTS games. In games players usually have to select a static difficulty level when playing against computer oppo- nents. In the first study we use a bot that during runtime can adapt the difficulty level depending on the skills of the opponent, and study how it affects the perceived enjoyment and variation in playing against the bot. To create bots that are interesting and challenging for human players a goal is often to create bots that play more human-like. In the second study we asked participants to watch replays of recorded RTS games between bots and human players. The participants were asked to guess and motivate if a player was controlled by a human or a bot. This information was then used to identify human-like and bot-like characteristics for RTS game players.

Researchers have been studying virtual world culture for decades. However, little attention has been devoted to the intersection of virtual world culture and real world culture. Even less attention has been given to the study of comparing players' different virtual world game behaviors that have been influenced by their own real world cultural background. In this paper, I specifically focus on identifying the differences among American, Chinese, and Taiwanese cultures and the unique aspects of players with distinct cultural backgrounds that alter the atmosphere of the game. This is a mixed-method ﾓtrans ludicﾔ? study across three game servers that included participant observation, interviews, and surveys. The result of this study show that real world culture influences virtual world culture. Players in different countries bring real life experiences to the game and form their own emergent sub-cultures and sub-rules under the larger structure of the designated game rules and social conventions. When players immigrate from their original server to other countries' servers, initially they tend to find people from the same country to play with and follow their old social conventions, which are the sub-rules they create in their old servers, rather than play with the local players and adapt to new customs. However, over time, players develop hybrid cultures that adopt features from both the old cultures. This study also demonstrates that emergent behaviors are likely to occur when players face problems or difficult challenges.

The concept of emergent behavior is difficult to define, but can be considered as higher-level activity created by the individual actions of a population of simple agents. A potential means to model such behavior has been previously developed using Alfred North Whitehead's concept of Actual Entities. In computational form, actual entities are agents which evolve over time in response to interactions with their environment via the process of prehension. This occurs within the context of a Colony of Prehending Entities, a framework for implementation of AE concepts. This thesis explores the practical application of this framework in analysis of medical images, with specific focus on Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) scans. Specialized Slice COPEs are developed for analysis of individual image slices from these scans, focusing on the detection and segmentation of structures of interest (such as bone matter, ventricular tissue, and tumors). These structures exist in 3D and can be extracted across multiple consecutive scan slices. Therefore, a specialized Scan COPE is also proposed which aims to render the structure's volume via interpolation between previously analyzed slice images. The software developed for the specified application also provides visualization of a COPE's evolution toward its goal. This has additional value in general study of the COPE framework and the emergent behavior it generates.

This thesis presents work based on modeling multi-agent coalition formation in an agent organized network. Agents choose which agents to connect with in the network. Tasks are periodically introduced into the network. Each task is defined by a set of skills that agents must fill. Agents form a coalition to complete a task by either joining an existing coalition a network neighbor belongs to, or by proposing a new coalition for a task no agents have proposed a coalition for. We introduce task patience and strategic task selection and show that they improve the number of successful coalitions agents form. We also introduce new methods of choosing agents to connect to in the network and compare the performance of these and existing methods.

Reúso de software, principalmente quando apoiado por ferramentas computacionais, é uma forma de enfrentar os constantes desafios da Engenharia de Software em aumentar a produtividade e qualidade no desenvolvimento de software. Diversos ambientes de apoio ao reúso de software têm sido propostos, em sua maioria com objetivos específicos, por exemplo, repositórios de componentes, ferramentas para geração de aplicações e ferramentas para configuração de linhas de produtos. Entretanto, a integração desses ambientes é, muitas vezes, deficiente e deixada por conta do próprio desenvolvedor. Por outro lado, Sistemas-de-Sistemas (SoS) constituem uma forma de integrar sistemas independentes e seus relacionamentos, formando um todo maior que a soma das partes. Dessa forma, o SoS permite alcançar objetivos complexos que não poderiam ser facilmente alcançados individualmente pelos seus sistemas constituintes. Em um SoS, comportamentos emergentes podem surgir a qualquer momento ou terem sido previamente implementados. Por serem recentes, os conceitos de SoS ainda apresentam uma vasta gama de tópicos em aberto, entre eles sua aplicação a ambientes de reúso de software. Assim, neste trabalho, investigou-se como integrar ambientes de reúso com base nos conceitos de SoS. O SoS resultante, denominado SoS-Reúso, visa facilitar a implementação de comportamentos emergentes relacionados ao reúso de software. Com isso, pode-se potencializar a atividade de reúso, facilitando a busca por ativos reusáveis em diferentes sistemas constituintes. Para colocar em prática essa ideia, desenvolveu-se um simulador do SoS-Reúso, denominado P-SoS-Reúso. Realizou-se um estudo qualitativo da usabilidade e adequação funcional do P-SoS-Reúso, a fim de obter do usuário feedbacks em relação ao seu uso. A abordagem utilizada no desenvolvimento do SoS-Reúso poderá ser adaptada futuramente para integrar outros tipos de sistemas, os quais poderiam se beneficiar da abordagem baseada em SoS. / Software reuse, specially when supported by computational tools, is a way to face the constant challenges of Software Engineering in increasing productivity and quality in software development. Several enviroments to support software reuse have been proposed, mostly for specific purposes, for example, component repositories, application generation tools, and tools for configuring product lines. However, the integration among these environments is often deficient and left to the developerss responsibility. On the other hand, Systems-of-Systems (SoS) is a way of integrating independent systems and their relationships, forming a whole greater than the sum of the parts. In this way, SoS allows us to achieve complex goals that could not be easily achieved individually by their constituent systems. In a SoS, emergent behaviors can arise at any time or have been previously implemented. Because they are recent, SoS concepts still feature a variety of open research topics, including their application to software reuse environments. Thus, in this work, we investigated how to integrate reuse environments based on SoS concepts. The resulting SoS, called SoS-Reuse, aims to facilitate the implementation of emergent behaviors related to software reuse. This allows to enhance the reuse activity, facilitating the search for reusable assets in different constituent systems. To implement this idea, it was developed a simulator of the SoS-Reuse, named P-SoS-Reuse. An qualitative study of the usability and functional adequacy of the P-SoS-Reuse was performed to obtain feedback from users regarding its use. The approach used to develop SoS-Reuse can be adapted in the future to integrate other types of systems, which could benefit from the SoS-based approach.

Reúso de software, principalmente quando apoiado por ferramentas computacionais, é uma forma de enfrentar os constantes desafios da Engenharia de Software em aumentar a produtividade e qualidade no desenvolvimento de software. Diversos ambientes de apoio ao reúso de software têm sido propostos, em sua maioria com objetivos específicos, por exemplo, repositórios de componentes, ferramentas para geração de aplicações e ferramentas para configuração de linhas de produtos. Entretanto, a integração desses ambientes é, muitas vezes, deficiente e deixada por conta do próprio desenvolvedor. Por outro lado, Sistemas-de-Sistemas (SoS) constituem uma forma de integrar sistemas independentes e seus relacionamentos, formando um todo maior que a soma das partes. Dessa forma, o SoS permite alcançar objetivos complexos que não poderiam ser facilmente alcançados individualmente pelos seus sistemas constituintes. Em um SoS, comportamentos emergentes podem surgir a qualquer momento ou terem sido previamente implementados. Por serem recentes, os conceitos de SoS ainda apresentam uma vasta gama de tópicos em aberto, entre eles sua aplicação a ambientes de reúso de software. Assim, neste trabalho, investigou-se como integrar ambientes de reúso com base nos conceitos de SoS. O SoS resultante, denominado SoS-Reúso, visa facilitar a implementação de comportamentos emergentes relacionados ao reúso de software. Com isso, pode-se potencializar a atividade de reúso, facilitando a busca por ativos reusáveis em diferentes sistemas constituintes. Para colocar em prática essa ideia, desenvolveu-se um simulador do SoS-Reúso, denominado P-SoS-Reúso. Realizou-se um estudo qualitativo da usabilidade e adequação funcional do P-SoS-Reúso, a fim de obter do usuário feedbacks em relação ao seu uso. A abordagem utilizada no desenvolvimento do SoS-Reúso poderá ser adaptada futuramente para integrar outros tipos de sistemas, os quais poderiam se beneficiar da abordagem baseada em SoS. / Software reuse, specially when supported by computational tools, is a way to face the constant challenges of Software Engineering in increasing productivity and quality in software development. Several enviroments to support software reuse have been proposed, mostly for specific purposes, for example, component repositories, application generation tools, and tools for configuring product lines. However, the integration among these environments is often deficient and left to the developerss responsibility. On the other hand, Systems-of-Systems (SoS) is a way of integrating independent systems and their relationships, forming a whole greater than the sum of the parts. In this way, SoS allows us to achieve complex goals that could not be easily achieved individually by their constituent systems. In a SoS, emergent behaviors can arise at any time or have been previously implemented. Because they are recent, SoS concepts still feature a variety of open research topics, including their application to software reuse environments. Thus, in this work, we investigated how to integrate reuse environments based on SoS concepts. The resulting SoS, called SoS-Reuse, aims to facilitate the implementation of emergent behaviors related to software reuse. This allows to enhance the reuse activity, facilitating the search for reusable assets in different constituent systems. To implement this idea, it was developed a simulator of the SoS-Reuse, named P-SoS-Reuse. An qualitative study of the usability and functional adequacy of the P-SoS-Reuse was performed to obtain feedback from users regarding its use. The approach used to develop SoS-Reuse can be adapted in the future to integrate other types of systems, which could benefit from the SoS-based approach.

Abstract The global energy system is undergoing a slow but massive change, initiated by environmental concerns but it is increasingly driven also by the zero-marginal cost of renewable energy. This change includes an increase in the effort to make the electric power system the main transport path for energy in the future. A massive research and development effort has henceforth been put into modernizing the electricity grid towards a so-called Smart Grid, by combining the power grid with communication networks and automation, as well as modernized market systems and structures. This work contributes to this process by introducing two unique models. The first provides a tool for better understanding the impact of combined infrastructure networks with a simple yet complex model of a combined energy, communication and decision model. The second model provides a detailed agent-based environment of an electricity market, supporting various independent entities inside the market, as well as a high time resolution and the often-neglected aspect of coupled market stages. That is, all mis-predictions of the first market stage (day-ahead) have to be settled at the second (balancing) stage. Both models are then used to assess the problem of demand side management, in which the traditional practice of power production being adjusted to the demand is at least partially dropped and flexibility in the demand is used to match the supply – as such technologies are deemed crucial to integrate the unsteady supply from renewable resources, like wind and solar power. We find that complicated scaling effects can be found even in the simplified model, hinting at insufficient consideration of the complexities involved in the real world. We then go to show such unfavorable scaling effects also exist in the current market environment as modeled in our second model. Finally, we show how to circumvent these problems within the current environment as well as introduce a framework to analyze cyber-physical systems and better handle their complexity. / Tiivistelmä Globaali energiajärjestelmä on hitaan, mutta massiivisen muutoksen edessä. Tämän muutostarpeen on käynnistänyt ympäristöämme koskevat huolet, mutta lisääntyvässä määrin tähän vaikuttaa nykyään uusiutuvan energian marginaalikustannusten nollataso. Tähän muutokseen liittyy selkeä sähköverkkojen roolin korostuminen, ja pyrkimyksenä näyttää olevan muutos, jossa sähköverkot siirtävät suurimman osan käyttämästämme energiasta. Tämän seurauksena on käynnistetty merkittäviä tutkimus-ja tuotekehityspanostuksia, joiden tavoitteena on nykyaikaistaa sähköverkot älysähköverkoiksi. Älysähköverkoissa yhdistyvät sähköverkkoon integroidut tietoliikenneverkot ja automaatio sekä modernit sähkömarkkinajärjestelmät ja -rakenteet. Tämä työ tuottaa lisää ymmärrystä uudistumisprosessiin tuottamalla kaksi uutta malliratkaisua. Ensimmäisessä mallissa kehitetään työkalu, jonka avulla pystytään paremmin ymmärtämään toisiinsa yhdistettyjen infrastruktuuriverkkojen toimintaa yksinkertaisella, mutta kompleksisella mallilla, jossa energia- ja tietoliikenneverkot sekä tarvittava päätöksenteko yhdistetään. Toinen malli tuottaa yksityiskohtaisen agenttipohjaisen ympäristön sähkömarkkinasta. Malli tukee erilaisten itsenäisten sähkömarkkinaosapuolten mallintamista korkealla aikaresoluutiolla ja erityisesti usein huomiotta jätettyjen toisiinsa kytkeytyvien eri markkinavaiheiden mallintamista. Malli antaa eväitä vastata kysymykseen, miten ensimmäisessä markkinavaiheessa (vuorokausimarkkina) syntyvä ero tuotannon ja kulutuksen välillä tasapainotetaan toisessa markkinavaiheessa (tasapainotusmarkkina). Kumpaakin luotua mallia hyödynnetään arvioitaessa kulutushallintaa, jossa sähköverkkojen perinteisestä tuotannon ja kulutuksen tasapainosta ainakin osittain luovutaan ja kysyntä- eli kulutusjoustoa käytetään tasaamaan kulutus tuotannon suuruiseksi. Tämänkaltaiset mekanismit ovat oleellisia ja kriittisiä, kun sähköverkkoon liitetään suuria määriä vaihtelevatuottoista uusiutuvaa energiaa, kuten aurinko- ja tuulienergiaa. Tutkimuksessa huomasimme merkittäviä ja monimutkaisia skaalautuvuusilmiöitä, jotka kertovat, että sähköverkkojen tutkimuksessa reaalimaailman kompleksisuuden huomioiminen on ollut riittämätöntä. Sähkömarkkinamallia hyödyntämällä huomasimme vastaavia epätoivottuja skaalausilmiöitä esiintyvän myös nykyisessä sähkömarkkinassa. Erityisesti loimme keinoja, joilla skaalausilmiöistä on mahdollista päästä eroon nykyistä sähkömarkkinarakennetta käytettäessä. Tässä työssä luotuja malleja ja niiden viitekehystä hyödyntämällä pystymme paremmin analysoimaan kyberfysikaalisia järjestelmiä ja hallitsemaan niiden kompleksisuutta.

This thesis develops a simulation and visualization of a path finding algorithm based on ant pheromone paths created in 3D space. The simulation is useful as a demonstration of a heuristic approach to NP-complete problems and as an educational tool for demonstrating how ant colonies gather food. An interactive real time 3D visualization is built on top of the simulation. A graphical user interface layer allows user interaction with the simulation and visualization.

Made available in DSpace on 2016-06-02T20:30:11Z (GMT). No. of bitstreams: 1 6771.pdf: 2633293 bytes, checksum: 5e96d8a978a1500ee7076ecfbaf044d3 (MD5) Previous issue date: 2015-03-10 / Universidade Federal de Minas Gerais / Animal experimentation with several species contributes to knowledge and understanding of different learning principles and aspects of human behavior. The domestic dog has been appointed as interesting to the comparative study with humans because of the long history of sharing the same physical and social environment. Among the lines of research pursued with dogs, two are of greater importance for the studies presented in this Thesis: sensitivity to human social cues and investigation of potentially symbolic behavior. Article 1 aimed to investigate the role of ontogenetic learning in the sensitivity to social cues of puppies in two experiments. The main results showed that exposure to human social environment had a significant impact on the performance of subjects, as well as the different degrees of salience of the social cues. Article 2 provides a number of experimental techniques used in studies with dogs, monkeys and bees in attempts to establish visual arbitrary conditional relations between stimuli. These techniques were insufficient to produce such a repertoire in dogs and bees and were partially effective with capuchin monkeys. For dogs, there was a prominent interference of preference for positions or stimuli during the procedure. Article 3 presents an experiment of responding by exclusion in a context of simple discrimination with adult dogs. The results showed evidence of exclusion responding for almost all subjects. Finally, Article 4 aimed to replicate the exclusion results presented in Article 3, adding some experimental controls, and evaluate emergent learning as a result of exclusion trials. The data pointed that, again, the dogs showed exclusion responding, however, learning of new functions of stimuli only occurred after a few repetitions of exclusion trials. Combined, these results add data to the literature of behavioral repertoire with dogs and basic learning processes regarding both sensitivity to social cues and symbolic behavior. / O estudo com animais de diversas especies contribui para o conhecimento e compreensao de diferentes principios de aprendizagem e aspectos do comportamento humanos. O cao domestico tem sido apontado como interessante ao estudo comparativo com o homem devido a longa historia de compartilhamento do mesmo ambiente fisico e social entre ambos. Dentre as linhas de pesquisa desenvolvidas com caes, duas sao de grande importancia para o desenvolvimento dos trabalhos apresentados nessa Tese: sensibilidade a dicas sociais humanas e investigacoes sobre comportamento potencialmente simbolico. O Artigo 1 artigo teve o objetivo de investigar o papel da aprendizagem ontogenetica na sensibilidade a dicas sociais em filhotes de caes em dois experimentos. Como principais resultados, encontrou-se que a exposicao ao ambiente social humano teve importante impacto sobre o desempenho dos sujeitos, bem como os diferentes graus de saliencia das dicas usadas. O Artigo 2 apresenta uma serie de recursos experimentais usados em estudos com caes, abelhas e macacos-prego em tentativas de estabelecimento de relacoes condicionais arbitrarias visuais entre estimulos. Tais recursos foram insuficientes para produzir o repertorio desejado em caes e abelhas e foram parcialmente efetivos com macacos-prego. No caso dos caes, observou-se grande interferencia de preferencia por posicoes ou estimulos durante o procedimento. O Artigo 3 apresenta um experimento de responder por exclusao em um contexto de discriminacoes simples com caes adultos. Os resultados apontaram para evidencias de responder por exclusao para praticamente todos os sujeitos. Finalmente, o Artigo 4 teve o objetivo de replicar os dados de exclusao obtidos no Artigo 3 acrescentando alguns controles experimentais e avaliacao de aprendizagem emergente decorrente das tentativas de exclusao. Os dados apontaram que, novamente, os caes apresentaram responder por exclusao, no entanto, a aprendizagem das funcoes de novos estimulos so ocorreu apos algumas repeticoes de tentativas de exclusao. Em conjunto, os resultados acrescentam dados a literatura da area de estudos de repertorios comportamentais com caes e investigacao de processos basicos de aprendizagem tanto no que se refere a sensibilidade a dicas sociais, quanto comportamentos simbolicos.

No description available.