Mostrando recursos 1 - 20 de 85

  1. Thereshold logic technology mapping for emerging nanotechnologies

    Neutzling, Augusto
    Threshold logic is a powerful alternative paradigm for realizing Boolean functions in digital circuit design. A threshold logic function (TLF) can be roughly defined as a Boolean function in which the output is evaluated in terms of input weights and a threshold value. Although the subject has been investigated since the 1960’s, the lack of effective hardware implementation for threshold functions led to a loss of interest in developing a threshold logic design flow. However, for some emerging technologies, such as memristors, spintronic, quantum cellular automata (QCA) and resonant tunneling devices (RTD), such a logic design strategy seems to be...

  2. Map point optimization in keyframe-based SLAM using covisibbility graph and information fusion

    Concha, Edison Kleiber Titito
    SLAM (do inglês Simultaneous Localization and Mapping) Monocular baseado em Keyframes é uma das principais abordagens de SLAM Visuais, usado para estimar o movimento da câmera juntamente com a reconstrução do mapa sobre frames selecionados. Estas técnicas representam o ambiente por pontos no mapa localizados em um espaço tri-dimensional, que podem ser reconhecidos e localizados no frame. Contudo, estas técnicas não podem decidir quando um ponto do mapa se torna um outlier ou uma informação obsoleta e que pode ser descartada, ou combinar pontos do mapa que correspondem ao mesmo ponto tri-dimensional. Neste trabalho, apresentamos um método robusto para manter...

  3. Aplicação de conceitos de bancos de dados de grafos e relacional na criação de proposta e análise comparativa de abordagens para armazenamento de processos

    Viégas, Rafael Pedroni
    Business Process Management (BPM) area has been increasingly attracted the interest of the business community because users are looking for documentation and optimization. These documents can be an important method in helping to gain results such as reduced costs and increased productivity. However, to model processes is not enough. It is necessary to pay attention to efficient storage methods, allowing information to be handled and used in a practical and intelligent way. The present article compares the use of relational databases and graph databases, considering aspects such as performance in the execution of operations and proximity of the approach of...

  4. A simulation workflow to evaluate the performance of dynamic load balancing with over decomposition for iterative parallel applications

    Tesser, Rafael Keller
    In this thesis we present a novel simulation workflow to evaluate the performance of dynamic load balancing with over-decomposition applied to iterative parallel applications at low-cost. Its goals are to perform such evaluation with minimal application modification and at a low cost in terms of time and of resource requirements. Many parallel applications suffer from dynamic (temporal) load imbalance that can not be treated at the application level. It may be caused by intrinsic characteristics of the application or by external software and hardware factors. As demonstrated in this thesis, such dynamic imbalance can be found even in applications whose...

  5. Uma abordagem para a integração de sistemas industriais aplicando o conceito de internet das coisas e de modelos semanticos no contexto da industria 4.0

    Steinmetz, Charles
    Com a chegada da era da computação ubíqua, o número de dispositivos com poder computacional vêm crescendo de forma acelerada. A conexão desses dispositivos em uma rede de comunicação traz novas possibilidades e serve como base para o conceito chamado Internet das Coisas (Internet of Things - IoT). Uma das aplicações desse conceito é no domínio industrial e está impulsionando uma nova revolução industrial, a chamada Indústria 4.0. Esta pesquisa apresenta uma abordagem de integração de componentes de forma automatizada, no contexto da Indústria 4.0, utilizando ontologias para representar os elementos do sistema e um middleware IoT para servir de...

  6. Aurora : seamless optimization of openMP applications

    Lorenzon, Arthur Francisco
    Efficiently exploiting thread-level parallelism has been challenging for software developers. As many parallel applications do not scale with the number of cores, blindly increasing the number of threads may not produce the best results in performance or energy. However, the task of rightly choosing the ideal amount of threads is not straightforward: many variables are involved (e.g. off-chip bus saturation and overhead of datasynchronization), which will change according to different aspects of the system at hand (e.g., input set, micro-architecture) and even during execution. To address this complex scenario, this thesis presents Aurora. It is capable of automatically finding, at...

  7. PDRM : a proactive data replication mechanism to improve content mobility support in NDN using location awareness

    Lehmann, Matheus Brenner
    The problem of handling user mobility has been around since mobile devices became capable of handling multimedia content and is still one of the most relevant challenges in networking. The conventional Internet architecture is inadequate in dealing with an ever-growing number of mobile devices that are both consuming and producing content. Named Data Networking (NDN) is a network architecture that can potentially overcome this mobility challenge. It supports consumer mobility by design but fails to offer the same level of support for content mobility. Content mobility requires guaranteeing that consumers manage to find and retrieve desired content even when the...

  8. Energy-efficient memory architecture design and management for parallel video coding

    Sampaio, Felipe Martin
    This Thesis presents the design of an energy-efficient hybrid scratchpad video memory architecture (called Hy-SVM) for parallel High-Efficiency Video Coding. Video coding stands out as a high complex part in the video processing applications. HEVC standard brought innovations that increase the memory requirements, mainly due to: (a) the novel coding structures, which aggravates the computational complexity by providing a wider range of possibilities to be analyzed; and (b) the high-level parallelism features provided by the Tiles partitioning, which provides performance acceleration, but, at the same time, strongly adds hard challenges to the memory infrastructure. The main bottleneck in terms of...

  9. Everyday visualization: discovering more about individuals

    Pagno, Bruno Lorandi
    People are becoming increasingly more interested in the use of activity monitors and selfimprovement. The availability of individuals’ data is also pushing the development of new applications and data visualization projects to be used at home, in science (e.g. to better understand the behavior of populations) or for governments interested in developing intelligent cities. In this work, we present an easy and intuitive set of visualizations to allow the exploration of personal data by common people. We focus on helping people to know themselves better and to make sense of their own data. Our visualizations are based on the metaphors...

  10. Exploração autônoma utilizando SLAM monocular esparso

    Pittol, Diego
    Nos últimos anos, observamos o alvorecer de uma grande quantidade de aplicações que utilizam robôs autônomos. Para que um robô seja considerado verdadeiramente autônomo, é primordial que ele possua a capacidade de aprender sobre o ambiente no qual opera. Métodos de SLAM (Localização e Mapeamento Simultâneos) constroem um mapa do ambiente por onde o robô trafega ao mesmo tempo em que estimam a trajetória correta do robô. No entanto, para obter um mapa completo do ambiente de forma autônoma é preciso guiar o robô por todo o ambiente, o que é feito no problema de exploração. Câmeras são sensores baratos...

  11. NFV-PEAR : posicionamento e encadeamento adaptativo de funções virtuais de rede

    Miotto, Gustavo
    O projeto de mecanismos flexíveis e eficientes para o posicionamento e encadeamento de funções virtualizadas de rede (VNFs) é essencial para o sucesso de Virtualização de Funções de Rede (Network Function Virtualization, NFV). A maioria das soluções existentes, no entanto, considera custos fixos (e imutáveis) de processamento de fluxos e de largura de banda ao posicionar as VNFs em Pontos de Presença da Rede (N-PoPs). Essa limitação torna-se crítica em redes NFV com fluxos cujos comportamentos são altamente dinâmicos e nas quais os requisitos de processamento e os recursos disponíveis nos NPoPs mudam constantemente. Para preencher essa lacuna, propõe-se o...

  12. Regret minimisation and system-efficiency in route choice

    Ramos, Gabriel de Oliveira
    Multiagent reinforcement learning (MARL) is a challenging task, where self-interested agents concurrently learn a policy that maximise their utilities. Learning here is difficult because agents must adapt to each other, which makes their objective a moving target. As a side effect, no convergence guarantees exist for the general MARL setting. This thesis exploits a particular MARL problem, namely route choice (where selfish drivers aim at choosing routes that minimise their travel costs), to deliver convergence guarantees. We are particularly interested in guaranteeing convergence to two fundamental solution concepts: the user equilibrium (UE, when no agent benefits from unilaterally changing its...

  13. Adaptive and polymorphic VLIW processor to dynamically balance performance, energy consumption, and fault tolerance

    Sartor, Anderson Luiz
    Performance is no longer the only optimization goal when designing a new processor. Reducing energy consumption is also mandatory: while most of the embedded devices are heavily dependent on battery power, General-Purpose Processors (GPPs) are being pulled back by the limits of Thermal Design Power (TDP). Moreover, due to technology scaling, soft error rate (i.e., transient faults) has been increasing in modern processors, which affects the reliability of both space and ground-level systems. In addition, most traditional homogeneous and heterogeneous processors have a fixed design, which limits its runtime adaptability. Therefore, they are not able to cope with the changing...

  14. Virtual network embedding in software-defined networks

    Bays, Leonardo Richter
    Research on network virtualization has been active for a number of years, during which a number of virtual network embedding (VNE) approaches have been proposed. These approaches, however, neglect important operational requirements imposed by the underlying virtualization platforms. In the case of SDN/OpenFlow-based virtualization, a crucial example of an operational requirement is the availability of enough memory space for storing flow rules in OpenFlow devices. Due to these circumstances, we advocate that VNE must be performed with some degree of knowledge of the underlying physical networks, otherwise the deployment may suffer from unpredictable or even unsatisfactory performance. Considering SDN/OpenFlow-based physical...

  15. Representação semântica de perfil dinâmico de usuários em comunidades de prática

    Pereira, Matheus
    Em comunidades de prática, a aprendizagem ocorre por meio da interação e colaboração constante de seus participantes, o caráter social destes ambientes é fundamental para a construção do conhecimento. Por este motivo, esta dissertação busca compreender a forma como os usuários interagem em comunidades de prática e propõe a estruturação destas informações em torno de um perfil dinâmico de usuário. A aplicação de perfis de usuário neste contexto permite entender o indivíduo, seus interesses e necessidades. A partir da representação dos participantes de comunidades de prática é possível desenvolver sistemas de aprendizagem inteligente, sistemas de recomendação, elementos de gamificação e...

  16. Evaluating immersive approaches to multidimensional information visualization

    Wagner Filho, Jorge Alberto
    The use of novel displays and interaction resources to support immersive data visualization and improve the analytical reasoning is a research trend in Information Visualization. In this work, we evaluate the use of HMD-based environments for the exploration of multidimensional data, represented in 3D scatterplots as a result of dimensionality reduction. We present a new modelling for the evaluation problem in such a context, accounting for the two factors whose interplay determine the impact on the overall task performance: the difference in errors introduced by performing dimensionality reduction to 2D or 3D, and the difference in human perception errors under...

  17. AwARE : an approach for adaptive recommendation of resources

    Machado, Guilherme Medeiros
    Sistemas de recomendação foram propostos no início da década de 1990 com o objetivo de auxiliar seus usuários a lidar com a sobrecarga cognitiva criada com o advento da internet e o aumento constante de documentos. De lá para cá tais sistemas passaram a assumir vários outros papéis, tais como “auxiliar usuários a explorar”, “melhorar a tomada de decisão”, ou até mesmo “entreter”. Para atingir tais novos objetivos, o sistema necessita olhar para características do usuário que auxiliem no entendimento da tarefa desempenhada pelo usuário e como a recomendação pode auxiliar tal tarefa. Nesse sentido, propõe-se nessa tese uma integração...

  18. Adaptação dinâmica do número de threads em aplicações paralelas openMP para otimizar EDP em sistemas embarcados

    Schwarzrock, Janaina
    Aplicações paralelas geralmente são executadas com o máximo número de threads de hardware disponíveis no sistema para maximizar o seu desempenho. Contudo, esta abordagem pode não ser a melhor escolha quando se busca eficiência energética e, em alguns casos, pode até mesmo degradar o desempenho. Desta maneira, o presente trabalho aplica a adaptação dinâmica do número de threads para otimizar o Energy-Delay Product (EDP) de aplicações paralelas OpenMP executadas em sistemas embarcados. Ao contrário de soluções anteriores, que focam em processadores de propósito geral (GPP, do inglês General Purpose Processors), o presente trabalho considera as características intrínsecas de sistemas embarcados,...

  19. Process modeling guidelines : systematic literature review and experiment

    Avila, Diego Toralles
    Process modeling is an indispensable task in the discipline of Business Process Management. The process models created in this task help its readers in to acquiring a higher comprehension of a process, allowing for the discovery of opportunities for its improvement. However, the comprehension of a process model is not guaranteed, as process modeling is a complex task that depends on the proficiency of the process modeler to avoid the creation of badly designed constructs. Process modeling guidelines are an essential tool in this regard, though they are dispersed across the many studies of the literature and not all of...

  20. A novel classification method applied to well log data calibrated by ontology based core descriptions

    Graciolli, Vinicius Medeiros
    A method for the automatic detection of lithological types and layer contacts was developed through the combined statistical analysis of a suite of conventional wireline logs, calibrated by the systematic description of cores. The intent of this project is to allow the integration of rock data into reservoir models. The cores are described with support of an ontology-based nomenclature system that extensively formalizes a large set of attributes of the rocks, including lithology, texture, primary and diagenetic composition and depositional, diagenetic and deformational structures. The descriptions are stored in a relational database along with the records of conventional wireline logs...

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