897 resultados para Abstraction.
Resumo:
Quantum mechanical calculations at the B3LYP theory level, together with the 6-31G* basis set, were employed to obtain the energy, ionization potential, and polarizabilites for dipyridamole and derivatives, which are compared with their biological activity. Density functional calculations of the spin densities were performed for radical formed by electron abstraction of dipyridamole and derivatives. The unpaired electron remains in dipyridamole is localized on the nitrogen atoms in the substituent positions 1, 3, 5, 7, 11, 12, 13, 14, with participation of the 9 and 10 carbons in the pyrimido-pyrimidine ring. The antioxidant activity is related with ionization potential, polarizability and Log P.
Resumo:
The thioxanthone-sensitized photodegradation of poly(alkyl methacrylate) films [alkyl = methyl, ethyl, butyl, and hexyl] was studied using near UV-vis light. The photooxidation process continued even after the total consumption of the sensitizer, possibly due to the excitation of the ketyl groups formed during the first stages of the process. The rate of oxidation, as well as the formation of hydroxy, peroxy, and ketyl groups was faster for polymers with larger ester groups. The decrease of the molecular weight of the degradated polymers was also larger for the hexyl substituted polymer. The side-chain size effect was attributed to the larger amount of secondary hydrogens available for abstraction by the triplet state of thioxanthone, present in the larger ester groups. The lower glass transition temperature of the hexyl substituted polymer allows a better diffusion of oxygen to the deeper layers of the films that also contributes to the faster photodegradation rate. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 115: 1283-1288, 2010
Resumo:
We propose a preliminary methodology for agent-oriented software engineering based on the idea of agent interaction analysis. This approach uses interactions between undetermined agents as the primary component of analysis and design. Agents as a basis for software engineering are useful because they provide a powerful and intuitive abstraction which can increase the comprehensiblity of a complex design. The paper describes a process by which the designer can derive the interactions that can occur in a system satisfying the given requirements and use them to design the structure of an agent-based system, including the identification of the agents themselves. We suggest that this approach has the flexibility necessary to provide agent-oriented designs for open and complex applications, and has value for future maintenance and extension of these systems.
Resumo:
The requirement for Grid middleware to be largely transparent to individual users and at the same time act in accordance with their personal needs is a difficult challenge. In e-science scenarios, users cannot be repeatedly interrogated for each operational decision made when enacting experiments on the Grid. It is thus important to specify and enforce policies that enable the environment to be configured to take user preferences into account automatically. In particular, we need to consider the context in which these policies are applied, because decisions are based not only on the rules of the policy but also on the current state of the system. Consideration of context is explicitly addressed, in the agent perspective, when deciding how to balance the achievement of goals and reaction to the environment. One commonly-applied abstraction that balances reaction to multiple events with context-based reasoning in the way suggested by our requirements is the belief-desire-intention (BDI) architecture, which has proven successful in many applications. In this paper, we argue that BDI is an appropriate model for policy enforcement, and describe the application of BDI to policy enforcement in personalising Grid service discovery. We show how this has been implemented in the myGrid registry to provide bioinformaticians with control over the services returned to them by the service discovery process.
Resumo:
BDI agent languages provide a useful abstraction for complex systems comprised of interactive autonomous entities, but they have been used mostly in the context of single agents with a static plan library of behaviours invoked reactively. These languages provide a theoretically sound basis for agent design but are very limited in providing direct support for autonomy and societal cooperation needed for large scale systems. Some techniques for autonomy and cooperation have been explored in the past in ad hoc implementations, but not incorporated in any agent language. In order to address these shortcomings we extend the well known AgentSpeak(L) BDI agent language to include behaviour generation through planning, declarative goals and motivated goal adoption. We also develop a language-specific multiagent cooperation scheme and, to address potential problems arising from autonomy in a multiagent system, we extend our agents with a mechanism for norm processing leveraging existing theoretical work. These extensions allow for greater autonomy in the resulting systems, enabling them to synthesise new behaviours at runtime and to cooperate in non-scripted patterns.
Resumo:
John Rawls’s A Theory of Justice (1971), his first major work articulating his theory of justice as fairness, was immediately recognized as a fundamental contribution to political philosophy in the twentieth century. Working within the tradition established by previous philosophers such as Kant and Locke, Rawls employed the contract theory approach. Taking it to a higher order of abstraction, he sought to determine not what the structure of social organization would be, but what the principles which governed social institutions would be under a hypothetical contracting situation. Rawls uses this contract theory approach to construct a society in which the morally irrelevant contingencies of nature and social arrangements are mitigated by principles of justice which govern the basic institutions of society. A common observation has been that Rawls left out any discussion of health care and how it might fit into his conception of a just society. Several philosophers have articulated expansions of the theory to account for health care. In the chapters that follow I will continue this tradition and consider how justice as fairness might be expanded to account for just health care allocation. In doing so, I hope to answer a particularly strong critique of the theory brought up by Amartya Sen and Martha Nussbaum, and to argue for a broadened conception of health care which takes into account the complex causal relationship between society and human health.
Resumo:
In retrospective, the Oxford movement of nineteenth century England provides one with an interesting study of the struggles between the spiritual and secular worlds. However, repeated abstraction in an interpretation of its significance has tended to distort accurate understanding of its historical development. Often this also has resulted n a misinterpretation of the nature of its major themes and their significance to the world. For these reasons, this study has attempted to describe the origin, maturity, and dissolution of the series of events which strictly speaking may be considered to be the Oxford movement. In conclusion, liberty has been taken to comment on the nature of the Movement's themes and their significance in their own age and to man today.
Resumo:
O estudo, fundamentado nas premissas teóricas sobre relações de trabalho, em especial de algumas variáveis que integram a categoria microssocial - organização do trabalho e condições de trabalho - aliadas às contribuições da Escola Dejouriana, que analisa os temas do prazer e do sofrimento vinculados ao trabalho, procura desvendar o processo de desgaste/prazer no trabalho dentro de um hospital universitário, trazido através do discurso dos trabalhadores de enfermagem ali atuantes, buscando captar suas realizações, dificuldades, alegrias, tramas e defesas, angústias, contradições, a luta pelo poder, as vivências subjetivas, os silêncios. A presente pesquisa de caráter exploratório, por meio de um roteiro com questões fechadas e entrevistas semi-estruturadas, envolvendo trinta e seis profissionais, representantes das categorias enfermeiro, técnico de enfermagem e auxiliar de enfermagem visou apreender a realidade laboral do Hospital Universitário de Juiz de Fora, tentando delinear os contextos de trabalho vividos como positivo ou negativos, denunciando pontos na convergência trabalhador-contexto de trabalho, a partir dos quais as mudanças devam ser impulsionadas, para que se possa criar novas.estratégias, dirimir conflitos e ampliar as possibilidades de auto-realização e prazer no trabalho. As categorias de análise definidas no estudo possibilitaram uma reflexão sobre os desafios e problemas que surgem da relação trabalhador/trabalho/instituição. O conhecimento dos fatores implicados na gênese do desgaste/prazer no trabalho de enfermagem abre espaço para que estes sejam gerenciados pelos trabalhadores em proveito de sua saúde e qualidade de vida. Em suma, temos que a trajetória da enfermagem de anjo de branco a profissional tem sido marcada por preconceitos, desgaste, sofrimento e luta por espaço laboral. Abandonando a posição de saber periférico e vulnerável, assistimos atualmente o esforço dos trabalhadores de enfermagem para a construção de uma nova imagem que contempla estratégias de revalorização do estatuto profissional, controle da formação, das carreiras e dos conteúdos do trabalho para que se tornem agentes privilegiados e ativos na melhoria das condições de saúde da comunidade e propulsoras de novas idéias para o avanço da gestão nas organizações hospitalares.
Resumo:
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.
Resumo:
The work described in this thesis aims to support the distributed design of integrated systems and considers specifically the need for collaborative interaction among designers. Particular emphasis was given to issues which were only marginally considered in previous approaches, such as the abstraction of the distribution of design automation resources over the network, the possibility of both synchronous and asynchronous interaction among designers and the support for extensible design data models. Such issues demand a rather complex software infrastructure, as possible solutions must encompass a wide range of software modules: from user interfaces to middleware to databases. To build such structure, several engineering techniques were employed and some original solutions were devised. The core of the proposed solution is based in the joint application of two homonymic technologies: CAD Frameworks and object-oriented frameworks. The former concept was coined in the late 80's within the electronic design automation community and comprehends a layered software environment which aims to support CAD tool developers, CAD administrators/integrators and designers. The latter, developed during the last decade by the software engineering community, is a software architecture model to build extensible and reusable object-oriented software subsystems. In this work, we proposed to create an object-oriented framework which includes extensible sets of design data primitives and design tool building blocks. Such object-oriented framework is included within a CAD Framework, where it plays important roles on typical CAD Framework services such as design data representation and management, versioning, user interfaces, design management and tool integration. The implemented CAD Framework - named Cave2 - followed the classical layered architecture presented by Barnes, Harrison, Newton and Spickelmier, but the possibilities granted by the use of the object-oriented framework foundations allowed a series of improvements which were not available in previous approaches: - object-oriented frameworks are extensible by design, thus this should be also true regarding the implemented sets of design data primitives and design tool building blocks. This means that both the design representation model and the software modules dealing with it can be upgraded or adapted to a particular design methodology, and that such extensions and adaptations will still inherit the architectural and functional aspects implemented in the object-oriented framework foundation; - the design semantics and the design visualization are both part of the object-oriented framework, but in clearly separated models. This allows for different visualization strategies for a given design data set, which gives collaborating parties the flexibility to choose individual visualization settings; - the control of the consistency between semantics and visualization - a particularly important issue in a design environment with multiple views of a single design - is also included in the foundations of the object-oriented framework. Such mechanism is generic enough to be also used by further extensions of the design data model, as it is based on the inversion of control between view and semantics. The view receives the user input and propagates such event to the semantic model, which evaluates if a state change is possible. If positive, it triggers the change of state of both semantics and view. Our approach took advantage of such inversion of control and included an layer between semantics and view to take into account the possibility of multi-view consistency; - to optimize the consistency control mechanism between views and semantics, we propose an event-based approach that captures each discrete interaction of a designer with his/her respective design views. The information about each interaction is encapsulated inside an event object, which may be propagated to the design semantics - and thus to other possible views - according to the consistency policy which is being used. Furthermore, the use of event pools allows for a late synchronization between view and semantics in case of unavailability of a network connection between them; - the use of proxy objects raised significantly the abstraction of the integration of design automation resources, as either remote or local tools and services are accessed through method calls in a local object. The connection to remote tools and services using a look-up protocol also abstracted completely the network location of such resources, allowing for resource addition and removal during runtime; - the implemented CAD Framework is completely based on Java technology, so it relies on the Java Virtual Machine as the layer which grants the independence between the CAD Framework and the operating system. All such improvements contributed to a higher abstraction on the distribution of design automation resources and also introduced a new paradigm for the remote interaction between designers. The resulting CAD Framework is able to support fine-grained collaboration based on events, so every single design update performed by a designer can be propagated to the rest of the design team regardless of their location in the distributed environment. This can increase the group awareness and allow a richer transfer of experiences among them, improving significantly the collaboration potential when compared to previously proposed file-based or record-based approaches. Three different case studies were conducted to validate the proposed approach, each one focusing one a subset of the contributions of this thesis. The first one uses the proxy-based resource distribution architecture to implement a prototyping platform using reconfigurable hardware modules. The second one extends the foundations of the implemented object-oriented framework to support interface-based design. Such extensions - design representation primitives and tool blocks - are used to implement a design entry tool named IBlaDe, which allows the collaborative creation of functional and structural models of integrated systems. The third case study regards the possibility of integration of multimedia metadata to the design data model. Such possibility is explored in the frame of an online educational and training platform.
Resumo:
Com a crise do modelo de produção fordista e o advento da última revolução industrial, mudaram a base técnica da produção e a organização do trabalho. Atualmente são outros os requerimentos que compõem o perfil do trabalhador. Há um privilegiamento da capacidade de abstração, do trabalho em equipe, do esprit de corps. A ênfase na preparação profissional passou a ser na formação geral. A pesar de alguns autores falarem de convergência de interesses com a classe trabalhadora, a ótica dessa formação continua sendo a do capital: não chega a questionar realmente a divisão entre trabalho manual e intelectual, por não estar inserida em projeto de mudança das relações sociais de exclusão e de alienação. Os trabalhadores, mergulhados no mundo da necessidade, da "preocupação", formulam representações sobre o trabalho, a educação e a preparação profissional baseando-se, sobretudo, no complexo fenomênico. Apesar de seus núcleos de bom senso, portanto, não alcançam uma compreensão concreta do real. Por isso, muitas vezes, buscam uma qualificação profissional que, no mínimo, a médio prazo, não servirá a seus interesses como cidadãos-trabalhadores. Na ótica do trabalho, é necessário pensar-se a formação escolar profissional com sólida base científica, com vistas à aquisição, por parte do trabalhador, de instrumental analítico, para a leitura do mundo e para a compreensão de sua inserção na produção e na trama de relações sociais.
Resumo:
O ensino dos Princípios de Física nas escolas de Ensino de Primeiro Grau oficial tem se mostrado ineficaz no que diz respeito ao preparo do aluno para compreender a Física do 2º grau, dificultando a integração do indivíduo na sociedade tecnológica contemporânea, quer no acesso a um mercado de trabalho de mão-de-obra especializada, como técnico, quer como candidato ao ensino de 3º grau. Os princípios da Ciência Contemporânea podem e devem ser mobilizados para a solução de problemas. A compreensão da Física contemporânea no nível de abstração em que se encontra, requer do indivíduo um pensamento favorito por estruturas que possibilitem operações abstratas. A Epistemologia Genética de Jean Piaget mostra que a explicação do mundo físico pelo indivíduo data dos primeiros contatos com a realidade. A estratutação dessa realidade vai-se tornando cada vez mais complexa de acordo com as possibilidades de raciocínio que o indivíduo possua para interpretá-la. O raciocínio é o resultado das operações realizadas pelo indivíduo, possibilitadas por estraturas mentais subjacentes. Essas estruturas se desenvolvem à medida que o indivíduo interage com o meio, permitindo de início uma interação sensório-motora, que, aos poucos, vai se operacionalizando até dominar o pensamento concreto, podendo então passar a realizar operações sobre operações que são chamadas de operações formais ou abstratas. Estas acontecem a partir da adolescência. Os princípios da Física lecionados nas escolas de Ensino de Primeiro Grau requerem para a sua compreensão, além do domínio do pensamento concreto, o pensamento formal. Realizou-se uma pesquisa com alunos de 7ª e 8ª séries do Ensino de Primeiro Grau e alunos da 2ª série do curso de formação de professores; verificou-se que esses sujeitos não haviam dominado as operações concretas nem tinham ainda atingido o início do pensamento formal. Consequentemente, a aprendizagem dos principios de Física que lhes são ministrados acha-se seriamente comprometido, fazendo-se necessária uma mudança de atitude do professor frente aos alunos, a fim de desenvolver o seu raciocfnio propiciando uma aprendizagem efetiva.
Resumo:
Nowadays, more than half of the computer development projects fail to meet the final users' expectations. One of the main causes is insufficient knowledge about the organization of the enterprise to be supported by the respective information system. The DEMO methodology (Design and Engineering Methodology for Organizations) has been proved as a well-defined method to specify, through models and diagrams, the essence of any organization at a high level of abstraction. However, this methodology is platform implementation independent, lacking the possibility of saving and propagating possible changes from the organization models to the implemented software, in a runtime environment. The Universal Enterprise Adaptive Object Model (UEAOM) is a conceptual schema being used as a basis for a wiki system, to allow the modeling of any organization, independent of its implementation, as well as the previously mentioned change propagation in a runtime environment. Based on DEMO and UEAOM, this project aims to develop efficient and standardized methods, to enable an automatic conversion of DEMO Ontological Models, based on UEAOM specification into BPMN (Business Process Model and Notation) models of processes, using clear semantics, without ambiguities, in order to facilitate the creation of processes, almost ready for being executed on workflow systems that support BPMN.
Resumo:
The development of robots has shown itself as a very complex interdisciplinary research field. The predominant procedure for these developments in the last decades is based on the assumption that each robot is a fully personalized project, with the direct embedding of hardware and software technologies in robot parts with no level of abstraction. Although this methodology has brought countless benefits to the robotics research, on the other hand, it has imposed major drawbacks: (i) the difficulty to reuse hardware and software parts in new robots or new versions; (ii) the difficulty to compare performance of different robots parts; and (iii) the difficulty to adapt development needs-in hardware and software levels-to local groups expertise. Large advances might be reached, for example, if physical parts of a robot could be reused in a different robot constructed with other technologies by other researcher or group. This paper proposes a framework for robots, TORP (The Open Robot Project), that aims to put forward a standardization in all dimensions (electrical, mechanical and computational) of a robot shared development model. This architecture is based on the dissociation between the robot and its parts, and between the robot parts and their technologies. In this paper, the first specification for a TORP family and the first humanoid robot constructed following the TORP specification set are presented, as well as the advances proposed for their improvement.
Resumo:
A avaliação do índice de qualidade da água (IQA) e do índice de estado trófico médio (IETm) pode subsidiar a formulação de planos de manejo e gestão de sistemas aquáticos. Neste trabalho, foi avaliada a qualidade da água da microbacia do Córrego Rico, que abastece a cidade de Jaboticabal (SP), utilizando o IQA e IETm. As amostragens de água foram realizadas entre setembro-2007 e agosto-2008, em três pontos: a) em uma das nascentes; b) após a Estação de Tratamento de Esgoto de Monte Alto, e c) na captação de água para abastecimento público de Jaboticabal. As amostras foram analisadas quanto aos parâmetros físicos, químicos e microbiológicos: temperatura, oxigênio dissolvido, pH, DBO5, nitrogênio total, fósforo total, turbidez, resíduo total, ortofosfato, clorofila-a e Escherichia coli. de acordo com os resultados obtidos, concluiu-se que: a) as atividades antrópicas às margens do Córrego Rico reduzem a qualidade de sua água, durante os diferentes períodos do ano; b) os valores médios de IQA nos três pontos analisados apresentaram relação direta com os valores médios de IETm, porém ocorreu maior discriminação da qualidade da água pelo IETm, identificando diferentes graus de trofia para os pontos e períodos de amostragens; c) o IQA apresentou melhor diferenciação da qualidade da água entre pontos no período seco e o IETm diferenciou melhor no período chuvoso; d) o processo de autodepuração e/ou a confluência do Córrego Tijuco com o Córrego Rico contribuem para melhor qualidade da água, tornando-a adequada ao abastecimento urbano após tratamento convencional.