890 resultados para Minkowski metrics


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The Multiobjective Spanning Tree is a NP-hard Combinatorial Optimization problem whose application arises in several areas, especially networks design. In this work, we propose a solution to the biobjective version of the problem through a Transgenetic Algorithm named ATIS-NP. The Computational Transgenetic is a metaheuristic technique from Evolutionary Computation whose inspiration relies in the conception of cooperation (and not competition) as the factor of main influence to evolution. The algorithm outlined is the evolution of a work that has already yielded two other transgenetic algorithms. In this sense, the algorithms previously developed are also presented. This research also comprises an experimental analysis with the aim of obtaining information related to the performance of ATIS-NP when compared to other approaches. Thus, ATIS-NP is compared to the algorithms previously implemented and to other transgenetic already presented for the problem under consideration. The computational experiments also address the comparison to two recent approaches from literature that present good results, a GRASP and a genetic algorithms. The efficiency of the method described is evaluated with basis in metrics of solution quality and computational time spent. Considering the problem is within the context of Multiobjective Optimization, quality indicators are adopted to infer the criteria of solution quality. Statistical tests evaluate the significance of results obtained from computational experiments

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Software Product Line (SPL) consists of a software development paradigm, whose main focus is to identify features common and variability among applications in a specific domain. An LPS is designed to attend all products requirements from its product family. These requirements and LPS may have changes over time due to several factors, such as evolution of product requirements, evolution of the market, evolution of SLP process, evolution of the technologies used to develop the products. To handle these changes, LPS should be modified and evolve in order to not become obsolete, and adapt itself to new requirements. The Changes Impact Analysis is an activity that understand and identify what consequences these changes are cause on LPS. Impact Analysis on LPS may be supported by traceability relationships, which identify relationships between artefacts created during all phases of software development. Despite the solutions of change impact analysis based on traceability for software, there is a lack of solutions for assessing the change impact analysis based on traceability for LPS, since existing solutions do not include estimates specific to the artefacts of LPS. Thus, this paper proposes a process of change impact analysis and an tool for assessing the change impact through traceability of artefacts in LPS. For this purpose, we specified a process of change impact analysis that considers artifacts produced during the development of LPS. We have also implemented a tool which allows estimating and identifying artefacts and products of LPS affected from changes in other products, changes in class, changes in features, changes between releases of LPS and artefacts related to changes in core assets and variability. Finally, the results were evaluated through metrics

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Product derivation tools are responsible for automating the development process of software product lines. The configuration knowledge, which is responsible for mapping the problem space to the solution space, plays a fundamental role on product derivation approaches. Each product derivation approach adopts different strategies and techniques to manage the existing variabilities in code assets. There is a lack of empirical studies to analyze these different approaches. This dissertation has the aim of comparing systematically automatic product derivation approaches through of the development of two different empirical studies. The studies are analyzed under two perspectives: (i) qualitative that analyzes the characteristics of approaches using specific criteria; and (ii) quantitative that quantifies specific properties of product derivation artifacts produced for the different approaches. A set of criteria and metrics are also being proposed with the aim of providing support to the qualitative and quantitative analysis. Two software product lines from the web and mobile application domains are targets of our study

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There is a need for multi-agent system designers in determining the quality of systems in the earliest phases of the development process. The architectures of the agents are also part of the design of these systems, and therefore also need to have their quality evaluated. Motivated by the important role that emotions play in our daily lives, embodied agents researchers have aimed to create agents capable of producing affective and natural interaction with users that produces a beneficial or desirable result. For this, several studies proposing architectures of agents with emotions arose without the accompaniment of appropriate methods for the assessment of these architectures. The objective of this study is to propose a methodology for evaluating architectures emotional agents, which evaluates the quality attributes of the design of architectures, in addition to evaluation of human-computer interaction, the effects on the subjective experience of users of applications that implement it. The methodology is based on a model of well-defined metrics. In assessing the quality of architectural design, the attributes assessed are: extensibility, modularity and complexity. In assessing the effects on users' subjective experience, which involves the implementation of the architecture in an application and we suggest to be the domain of computer games, the metrics are: enjoyment, felt support, warm, caring, trust, cooperation, intelligence, interestingness, naturalness of emotional reactions, believabiliy, reducing of frustration and likeability, and the average time and average attempts. We experimented with this approach and evaluate five architectures emotional agents: BDIE, DETT, Camurra-Coglio, EBDI, Emotional-BDI. Two of the architectures, BDIE and EBDI, were implemented in a version of the game Minesweeper and evaluated for human-computer interaction. In the results, DETT stood out with the best architectural design. Users who have played the version of the game with emotional agents performed better than those who played without agents. In assessing the subjective experience of users, the differences between the architectures were insignificant

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Aspect-Oriented Software Development (AOSD) is a technique that complements the Object- Oriented Software Development (OOSD) modularizing several concepts that OOSD approaches do not modularize appropriately. However, the current state-of-the art on AOSD suffers with software evolution, mainly because aspect definition can stop to work correctly when base elements evolve. A promising approach to deal with that problem is the definition of model-based pointcuts, where pointcuts are defined based on a conceptual model. That strategy makes pointcut less prone to software evolution than model-base elements. Based on that strategy, this work defines a conceptual model at high abstraction level where we can specify software patterns and architectures that through Model Driven Development techniques they can be instantiated and composed in architecture description language that allows aspect modeling at architecture level. Our MDD approach allows propagate concepts in architecture level to another abstraction levels (design level, for example) through MDA transformation rules. Also, this work shows a plug-in implemented to Eclipse platform called AOADLwithCM. That plug-in was created to support our development process. The AOADLwithCM plug-in was used to describe a case study based on MobileMedia System. MobileMedia case study shows step-by-step how the Conceptual Model approach could minimize Pointcut Fragile Problems, due to software evolution. MobileMedia case study was used as input to analyses evolutions on software according to software metrics proposed by KHATCHADOURIAN, GREENWOOD and RASHID. Also, we analyze how evolution in base model could affect maintenance on aspectual model with and without Conceptual Model approaches

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The main goal of Regression Test (RT) is to reuse the test suite of the latest version of a software in its current version, in order to maximize the value of the tests already developed and ensure that old features continue working after the new changes. Even with reuse, it is common that not all tests need to be executed again. Because of that, it is encouraged to use Regression Tests Selection (RTS) techniques, which aims to select from all tests, only those that reveal faults, this reduces costs and makes this an interesting practice for the testing teams. Several recent research works evaluate the quality of the selections performed by RTS techniques, identifying which one presents the best results, measured by metrics such as inclusion and precision. The RTS techniques should seek in the System Under Test (SUT) for tests that reveal faults. However, because this is a problem without a viable solution, they alternatively seek for tests that reveal changes, where faults may occur. Nevertheless, these changes may modify the execution flow of the algorithm itself, leading some tests no longer exercise the same stretch. In this context, this dissertation investigates whether changes performed in a SUT would affect the quality of the selection of tests performed by an RTS, if so, which features the changes present which cause errors, leading the RTS to include or exclude tests wrongly. For this purpose, a tool was developed using the Java language to automate the measurement of inclusion and precision averages achieved by a regression test selection technique for a particular feature of change. In order to validate this tool, an empirical study was conducted to evaluate the RTS technique Pythia, based on textual differencing, on a large web information system, analyzing the feature of types of tasks performed to evolve the SUT

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Symbolic Data Analysis (SDA) main aims to provide tools for reducing large databases to extract knowledge and provide techniques to describe the unit of such data in complex units, as such, interval or histogram. The objective of this work is to extend classical clustering methods for symbolic interval data based on interval-based distance. The main advantage of using an interval-based distance for interval-based data lies on the fact that it preserves the underlying imprecision on intervals which is usually lost when real-valued distances are applied. This work includes an approach allow existing indices to be adapted to interval context. The proposed methods with interval-based distances are compared with distances punctual existing literature through experiments with simulated data and real data interval

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Control and automation of residential environments domotics is emerging area of computing application. The development of computational systems for domotics is complex, due to the diversity of potential users, and because it is immerse in a context of emotional relationships and familiar construction. Currently, the focus of the development of this kind of system is directed, mainly, to physical and technological aspects. Due to the fact, gestural interaction in the present research is investigated under the view of Human-Computer Interaction (HCI). First, we approach the subject through the construction of a conceptual framework for discussion of challenges from the area, integrated to the dimensions: people, interaction mode and domotics. A further analysis of the domain is accomplished using the theoretical-methodological referential of Organizational Semiotics. After, we define recommendations to the diversity that base/inspire the inclusive design, guided by physical, perceptual and cognitive abilities, which aim to better represent the concerned diversity. Although developers have the support of gestural recognition technologies that help a faster development, these professionals face another difficulty by not restricting the gestural commands of the application to the standard gestures provided by development frameworks. Therefore, an abstraction of the gestural interaction was idealized through a formalization, described syntactically by construction blocks that originates a grammar of the gestural interaction and, semantically, approached under the view of the residential system. So, we define a set of metrics grounded in the recommendations that are described with information from the preestablished grammar, and still, we conceive and implement in Java, under the foundation of this grammar, a residential system based on gestural interaction for usage with Microsoft Kinect. Lastly, we accomplish an experiment with potential end users of the system, aiming to better analyze the research results

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Currently the interest in large-scale systems with a high degree of complexity has been much discussed in the scientific community in various areas of knowledge. As an example, the Internet, protein interaction, collaboration of film actors, among others. To better understand the behavior of interconnected systems, several models in the area of complex networks have been proposed. Barabási and Albert proposed a model in which the connection between the constituents of the system could dynamically and which favors older sites, reproducing a characteristic behavior in some real systems: connectivity distribution of scale invariant. However, this model neglects two factors, among others, observed in real systems: homophily and metrics. Given the importance of these two terms in the global behavior of networks, we propose in this dissertation study a dynamic model of preferential binding to three essential factors that are responsible for competition for links: (i) connectivity (the more connected sites are privileged in the choice of links) (ii) homophily (similar connections between sites are more attractive), (iii) metric (the link is favored by the proximity of the sites). Within this proposal, we analyze the behavior of the distribution of connectivity and dynamic evolution of the network are affected by the metric by A parameter that controls the importance of distance in the preferential binding) and homophily by (characteristic intrinsic site). We realized that the increased importance as the distance in the preferred connection, the connections between sites and become local connectivity distribution is characterized by a typical range. In parallel, we adjust the curves of connectivity distribution, for different values of A, the equation P(k) = P0e

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Nowadays, there are many aspect-oriented middleware implementations that take advantage of the modularity provided by the aspect oriented paradigm. Although the works always present an assessment of the middleware according to some quality attribute, there is not a specific set of metrics to assess them in a comprehensive way, following various quality attributes. This work aims to propose a suite of metrics for the assessment of aspect-oriented middleware systems at different development stages: design, refactoring, implementation and runtime. The work presents the metrics and how they are applied at each development stage. The suite is composed of metrics associated to static properties (modularity, maintainability, reusability, exibility, complexity, stability, and size) and dynamic properties (performance and memory consumption). Such metrics are based on existing assessment approaches of object-oriented and aspect-oriented systems. The proposed metrics are used in the context of OiL (Orb in Lua), a middleware based on CORBA and implemented in Lua, and AO-OiL, the refactoring of OIL that follows a reference architecture for aspect-oriented middleware systems. The case study performed in OiL and AO-OiL is a system for monitoring of oil wells. This work also presents the CoMeTA-Lua tool to automate the collection of coupling and size metrics in Lua source code

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In order to evaluate the environmental condition of the Barra Bonita Reservoir, we adapted the Index of Biotic Integrity (IBI). We chose 24 sampling sites in which three types of habitats were sampled: the mouths of tributaries, the central reservoir and the lateral reservoir. Fish were caught in two seasons (dry and rainy) using 10 gillnet gangs, with meshes ranging from 3 to 12 cm between opposite knots, and funnel traps. Abiotic and biotic variables were measured. Due to the artificial nature of the reservoir, the term biotic integrity was considered inappropriate and the term RFAI (Reservoir Fish Assemblage Index) was adopted. Twelve metrics from sixteen possibles were selected using the Pearson correlation coefficient. The reference conditions were set up based on the criteria of the best condition observed. For each metric, a score of 1, 3 or 5 was assigned as it strongly departs (1), slightly departs (3) or approaches (5) the reference condition. The index value is the sum of the metrics partial scores and ranges from 12 to 60. To evaluate the importance of the unit of measurement of the metric, the index was calculated in fish number (RFAI(N)) and in weight (RFAI(w)). The correlation between RFAIN and RFAIw was very high (r = 0.90, n = 46) indicating that the unit of measurement does not influence the final result of the index. Most of the sampling sites were classified in the 'reasonable' RFAI category. Only the central sites were classified as 'poor'. To validate the RFAI, another index, the Habitat Quality Index (HQI), was built starting from the physiochemical and habitat variables collected. The correlation of the RFAI with the HQI was highly significant (RFAIN, r = 0.37; RFAI(w), r = 0.47; n = 46), indicating that they respond in the same way to environmental degradation. The HQI metrics which most affect RFAI were depth, surrounding landscape and macrophyte presence/absence. Copyright C) 2007 John Wiley & Sons, Ltd.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)