Orientador: Rodolfo Jardim de Azevedo / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Computação / Made available in DSpace on 2018-08-16T21:29:21Z (GMT). No. of bitstreams: 1 Firmino_RaoniFassina_M.pdf: 582747 bytes, checksum: c50225f2dc75c4235a785d90a82d71b2 (MD5) Previous issue date: 2010 / Resumo: Esta dissertação concentra-se no atual momento de transição entre as atuais e as novas arquiteturas de processadores, oferecendo uma alternativa para minimizar o impacto desta mudança. Para tal utiliza-se a plataforma Java, que possibilita que o desenvolvimento de aplicações seja independente da arquitetura em que serão executadas. Considerando a arquitetura Cell B.E. como uma nova plataforma que promete desempenho elevado, este trabalho propõe melhorias na Máquina Virtual Java que propiciem um ganho de desempenho na execução de aplicações Java executadas sobre o processador Cell. O objetivo proposto é atingido por meio da utilização do ambiente disponível na própria plataforma Java, o Java Native Interface (JNI), para a implementação de interfaces entre bibliotecas nativas construídas para a arquitetura Cell - com a intenção de obter o máximo desempenho possível - e as aplicações Java. É proposto um modelo para porte e criação das interfaces para bibliotecas e mostra-se a viabilidade da abordagem proposta através de implementações de bibliotecas selecionadas, consolidando a metodologia utilizada. Duas bibliotecas foram portadas completamente como prova de conceito, uma multiplicação de matrizes grandes e o algoritmo RC5. A multiplicação de matrizes obteve um desempenho e escalablidade comparável ao código original em C e em escala muitas vezes superior ao código JNI para arquitetura x86 a ao código Java executando em arquiteturas x86 e Cell. O RC5 executou apenas aproximadamente 0,3 segundos mais lento que o código C original (perda citada em segundos pois se manteve constante independente do tempo levado para as diferentes configurações de execução) / Abstract: This dissertation focuses on the present moment of transition between the current and new processor architectures, offering an alternative to minimize the impact of this change. For this, we use the Java platform, which enables an architecture-independent application development. Considering the Cell BE architecture as a new platform that promises high performance, this paper proposes improvements in the Java Virtual Machine that provide performance gains in the execution of Java applications running on the Cell processor. The proposed objective is achieved through the use of the environment available on the Java platform itself, the Java Native Interface (JNI), to implement interfaces between native libraries built for the Cell architecture - with the intention of obtaining the maximum possible performance - and the Java applications. It is proposed a model to port and build interfaces to libraries and it shows the viability of the proposed methodology with the implementation of selected libraries, consolidating the used methodology. Two libraries were completely ported as proof of concept, a multiplication of large matrices and a RC5 algorithm implementation. The matrices multiplication achieved scalability and performance in the same basis as the native implementation and incomparable with JNI implementation targering x86 architecture and Java implementation running in x86 and Cell architectures. The RC5 was just 0.3 seconds slower than the original C code (the loss is put in seconds since it was constant, independent of the execution time taken by different configurations of execution) / Mestrado / Computação / Mestre em Ciência da Computação

Orientadores: Marcos Lordello Chaim, Eliane Martins / Dissertação (mestrado profissional) - Universidade Estadual de Campinas, Instituto de Computação / Made available in DSpace on 2018-08-10T17:57:17Z (GMT). No. of bitstreams: 1 Moura_AndreToledoPizade_M.pdf: 1281133 bytes, checksum: 77e24a926c93bfe938f8d72bdd3140c6 (MD5) Previous issue date: 2006 / Resumo: Refatoração é o ato de modificar o código fonte de um programa de computador sem, contudo, modificar seu comportamento observável. Em outras palavras, é alterar a estrutura de um sistema de software sem que isso provoque qualquer efeito no resultado final de suas funcionalidades. As modificações são feitas visando deixar o código mais fácil de ser entendido por terceiros que venham a modificá-lo e, conseqüentemente, diminuir os custos de sua manutenção. Entretanto, esta atividade é complexa e sujeita a erros, uma vez que normalmente é realizada de forma manual e depende das habilidades e da obediência a padrões do mantenedor que está analisando o código. Os pontos do software onde refatorações devem ser aplicadas constituem oportunidades de refatoração. A construção de sistemas automáticos para a detecção de oportunidades de refatoração requer a implementação de ambientes para análise de código e de tratamento regras para identificação de padrões no código fonte. Este trabalho apresenta o SOCRATES ¿ Sistema Orientado a objetos para CaRacterização de refaToraçõES ¿ cujo objetivo é fornecer auxílio automático para a identificação dos pontos candidatos a serem refatorados, isto é, oportunidades de refatoração. Para atingir este objetivo, SOCRATES utiliza uma arquitetura leve. Essa arquitetura é baseada em ferramentas livres e disponíveis e requer pouca codificação adicional. A codificação adicional é utilizada para que as ferramentas trabalhem em conjunto e para que os algoritmos de identificação das oportunidades de refatoração sejam implementados de forma eficiente. A presente versão do SOCRATES identifica de maneira automática a oportunidade de refatoração parâmetro obsoleto e mostra que os conceitos arquiteturais utilizados são válidos / Abstract: Refactoring is the activity of modifying a computer program¿s source code without changing its external behavior. In other words, it consists of changing a software system¿s structure without affecting its functionalities. The changes are done in order to let the code more understandable for humans that might work on it. In this sense, its goal is to lower maintenance costs. Nevertheless, this activity is complex and error prone since it is usually carried out manually and is dependent on the maintainer¿s abilities and on his/her obedience to coding standards. The points of the software where refactorings should be applied are called refactoring opportunities. Building automatic systems to detect refactoring opportunities requires the implementation of environments which include source code analyzers and the treatment of rules to detect related patterns and standards. This work introduces SOCRATES ¿ Sistema Orientado a objetos para CaRacterização de refaToraçõES (Object Oriented System for Characterization of Refactorings) ¿ its main purpose is to automatically detect points to be refactored in the software, i.e., refactoring opportunities. To achieve this objective, SOCRATES is built upon a lightweight architecture. This architecture is based on open source tools and requires few additional coding. The additional coding was done to make the tools work together so that refactoring opportunities searcher algorithms could effectively work. The present version of SOCRATES identifies the obsolete parameter refactoring opportunity and shows that the architecture fundamentals used are valid / Mestrado / Engenharia de Computação / Mestre em Computação

With the rapid development of wireless technologies, traditional mobile devices, such as pagers and cellular phones, have evolved from a purely communications and messaging-oriented medium to one that supports mobile data communication in general and acts as an application platform. As shown in a recent survey conducted by MDA, easy access to the present-day wireless Internet has resulted in mobile devices gaining more and more attention and popularity. The growth of and demand for mobile Web applications is expected to increase rapidly in the near future, as a range of software companies and mobile device manufacturers release increasingly accessible tools for creating mobile Web application and services. From a variety of possible development environments of this kind, the author has selected and examined two leading contenders, the J2ME and the Microsoft .NET mobile Web application development environments. This document reports the product life cycle of pilot mobile web applications, designed and implemented in each host environment in tum. A feature-by-feature investigation and comparison of the J2ME and .NET environments was carried out, covering the range of issues necessary for a complete mobile Web application development life cycle. The resulting analysis addresses features and efficiencies of the application development environment and the target deployment environment, the degree to which the resultant services are compatible on a variety of platforms, and the ease with which applications can be designed to be extensible. The thesis offers an objective evaluation of the J2ME and the .NET mobile development environments, which highlights their strengths and weaknesses, and suggests guidelines for designing, creating, and deploying high quality mobile Web applications. The research uncovers no clear winner across all categories assessed. J2ME currently favours situations in which bandwidth is limited and client side processing power is relatively sufficient, it exerts the processing power of mobile devices over distributed network environments. .NET requires a less constrained network throughput, but performs adequately on clients with more limited processing power, supports a more diverse target platform range, and offers a more efficient, in terms of development time, development environment. Both technologies are likely to receive significant user support for some time. / KMBT_363 / Adobe Acrobat 9.54 Paper Capture Plug-in

A number of essential issues in translating Smalltalk to Java are addressed. The fIrst chapter gives a brief overview of Smalltalk and Java with respect to the relevant language features that will be translated. In the next section a convention is proposed for mapping Smalltalk method selectors to Java method names. The dynamic nature of Smalltalk instance methods is compared with Java's static type model as well as a solution to simulate the dynamic nature of Smalltalk in Java. A Java class hierarchy that parallels the Smalltalk class hierarchy (including the metaclass objects) is suggested. A further proposal is given for translating the dynamic attributes of Smalltalk class methods to the same behaviour to Java. These proposals are used to support ways of mapping both Smalltalk instance methods, as well as Smalltalk class methods to their Java counterparts. Ways of translating Smalltalk class variables, Smalltalk class instance variables and Smalltalk global variables are illustrated. A method for translating Smalltalk blocks to Java inner classes is implemented using Java exceptions to unwind the call stack. Various types of Small talk blocks are translated with increasing complexity. The various types of blocks translated are simple blocks; blocks with references to variables in the enclosing context; blocks with block arguments; blocks that need to refer to their own context executed from other contexts; blocks with multiple exit points as well as nested blocks. Some performance tests to illustrate the impact of using exceptions in Java are also reported. The next section introduces the Small talk grammar with the necessary productions used to implement a parser. Lexical and syntax analysis are explained. A brief overview of a recursive descent parser is given where an example of Smalltalk source code is parsed and all the relevant parse nodes illustrated. The encoding in each parse node to Java source is shown. The last section focuses on similar initiatives being pursued and compares the solutions in the dissertation against them. This dissertation focuses on key areas of the Smalltalk to Java translation process, but a few peculiar and unique Smalltalk features are not addressed. These are discussed in the last section and some suggestions are made on how the translations can be achieved. / Dissertation (MSc (Computer Science))--University of Pretoria, 2006. / Computer Science / unrestricted

The goal of this master project is to promote and facilitate the use of new web-based and Java-based technologies in the development of self-evaluation systems for computer science; in particular, analysis of sorting algorithms.

The purpose of the project is to use Java Server Page (JSP) technology to create a web application that could be used by any person who has the basic knowledge of browsing through the Web. There are many programs on the market that aid users in creating web pages, but the process involved in creating web pages using the available software and hosting their website is fairly complex for general people.

The goal of this project is to design a tool to help users translate any logic statement into Disjunctive Normal Form and present the result as an AND/OR TABLE, which makes the logic relation easier to express by using a two-dimensional grid of values or expressions. This tool is implemented through a web-based and Java-based application. Thus, the user can utilize this tool via World Wide Web.

No description available.

No description available.

Wireless communication provides an effective means by which mobile robots can be operated, field tested, and trained remotely. This thesis explores a design that is intended to simplify the process of creating communication software for these and other similar purposes. The proposed software is responsible for generating client-server modules that are able to be readily loaded into any number of wirelessly connected mobile robots and handheld devices. In general, the system is designed to be low-cost, simple to use, and robust, with particular design considerations for software portability and modularity. Portability is obtained by using the Java™ platform and modularity is obtained by incorporating object-oriented design. The test platform for this system is comprised of a Palm OS® handheld device, a Linux-based mobile robot, and a wireless Ethernet connection.