Com o crescimento e o desenvolvimento de aplicações para Redes de Sensores sem Fio (RSSF), os nós-sensores passaram a realizar o tratamento de eventos mais complexos, exigindo um maior desempenho de processamento e flexibilidade do hardware. Estas novas características visam atender os requisitos de diversas aplicações, assim como, apresentarem plataformas customizáveis que possuem somente os recursos necessários para atender estes requisitos. As RSSF, muitas vezes, necessitam de uma arquitetura flexível e que estejam aptas a adaptar-se a alterações de projeto ou do próprio ambiente em que se encontram inserido. A utilização de arquiteturas reconfiguráveis é uma solução que introduz esta flexibilidade e uma grande capacidade de processamento ao nó-sensor. Comparando com as arquiteturas ASICs (Application Specific Integrated Circuit), as arquiteturas reconfiguráveis apresentam um custo reduzido no desenvolvimento de aplicações, visto que a plataforma não fica fixa a somente uma aplicação. A reconfigurabilidade permite um ganho no custo e tempo de projeto, além de possibilitar o desenvolvimento de plataformas genéricas para atender um número maior de aplicações. A proposta destas plataformas é, não apenas oferecer uma plataforma eficiente e flexível, mas também potencializar a aplicação em sistemas mais complexos que necessitem de uma maior capacidade de processamento. Este trabalho apresenta o desenvolvimento de um nó-sensor reconfigurável e customizável para RSSF denominado FemtoNode. O FemtoNode possui em sua plataforma reconfigurável um processador especificado a partir de uma linguagem orientada a objetos Java e um módulo de comunicação sem fio para suportar comunicação entre os nós da rede. A arquitetura proposta foi validada com o estudo de caso de uma rede de sensores heterogênea composta por nós-sensores com plataformas distintas, sendo a análise realizada na presente dissertação. / With the growth and the development of new applications for Wireless Sensor Networks (WSN), sensors nodes are able to handle more complex events that require higher processing performance and hardware flexibility. These new features are intended to meet the requirements of various applications, as well to provide customized platforms that have only the resources needed to meet these requirements. WSNs often need a flexible architecture able to adapt to design and environment changes. The use of reconfigurable architectures is an alternative to bring more flexibility and more processing capability for the sensor-node. Compared with ASICs (Application Specific Integrated Circuit) architectures, which have a high cost in production setup, reconfigurable architectures enable a reduction in these costs because its architecture is not fixed to a single application. Reconfigurability allows a gain in the project costs and time development, and it enables the development of generic platforms to deal with a greater number of applications. Therefore, the proposal target architecture that aims to provide a flexible and efficient platform that require greater processing capacity which support the development of applications. In this work a reconfigurable and customizable sensor-node called FemtoNode is proposed. The FemtoNode has a reconfigurable platform and a wireless module to support applications for WSNs, using an object-oriented language Java as specification language of its architecture. The proposed concepts were validated with a case study of an heterogeneous wireless sensor composed of sensors nodes with different platforms, whose results are described in this work.

Com o crescimento e o desenvolvimento de aplicações para Redes de Sensores sem Fio (RSSF), os nós-sensores passaram a realizar o tratamento de eventos mais complexos, exigindo um maior desempenho de processamento e flexibilidade do hardware. Estas novas características visam atender os requisitos de diversas aplicações, assim como, apresentarem plataformas customizáveis que possuem somente os recursos necessários para atender estes requisitos. As RSSF, muitas vezes, necessitam de uma arquitetura flexível e que estejam aptas a adaptar-se a alterações de projeto ou do próprio ambiente em que se encontram inserido. A utilização de arquiteturas reconfiguráveis é uma solução que introduz esta flexibilidade e uma grande capacidade de processamento ao nó-sensor. Comparando com as arquiteturas ASICs (Application Specific Integrated Circuit), as arquiteturas reconfiguráveis apresentam um custo reduzido no desenvolvimento de aplicações, visto que a plataforma não fica fixa a somente uma aplicação. A reconfigurabilidade permite um ganho no custo e tempo de projeto, além de possibilitar o desenvolvimento de plataformas genéricas para atender um número maior de aplicações. A proposta destas plataformas é, não apenas oferecer uma plataforma eficiente e flexível, mas também potencializar a aplicação em sistemas mais complexos que necessitem de uma maior capacidade de processamento. Este trabalho apresenta o desenvolvimento de um nó-sensor reconfigurável e customizável para RSSF denominado FemtoNode. O FemtoNode possui em sua plataforma reconfigurável um processador especificado a partir de uma linguagem orientada a objetos Java e um módulo de comunicação sem fio para suportar comunicação entre os nós da rede. A arquitetura proposta foi validada com o estudo de caso de uma rede de sensores heterogênea composta por nós-sensores com plataformas distintas, sendo a análise realizada na presente dissertação. / With the growth and the development of new applications for Wireless Sensor Networks (WSN), sensors nodes are able to handle more complex events that require higher processing performance and hardware flexibility. These new features are intended to meet the requirements of various applications, as well to provide customized platforms that have only the resources needed to meet these requirements. WSNs often need a flexible architecture able to adapt to design and environment changes. The use of reconfigurable architectures is an alternative to bring more flexibility and more processing capability for the sensor-node. Compared with ASICs (Application Specific Integrated Circuit) architectures, which have a high cost in production setup, reconfigurable architectures enable a reduction in these costs because its architecture is not fixed to a single application. Reconfigurability allows a gain in the project costs and time development, and it enables the development of generic platforms to deal with a greater number of applications. Therefore, the proposal target architecture that aims to provide a flexible and efficient platform that require greater processing capacity which support the development of applications. In this work a reconfigurable and customizable sensor-node called FemtoNode is proposed. The FemtoNode has a reconfigurable platform and a wireless module to support applications for WSNs, using an object-oriented language Java as specification language of its architecture. The proposed concepts were validated with a case study of an heterogeneous wireless sensor composed of sensors nodes with different platforms, whose results are described in this work.

Com o crescimento e o desenvolvimento de aplicações para Redes de Sensores sem Fio (RSSF), os nós-sensores passaram a realizar o tratamento de eventos mais complexos, exigindo um maior desempenho de processamento e flexibilidade do hardware. Estas novas características visam atender os requisitos de diversas aplicações, assim como, apresentarem plataformas customizáveis que possuem somente os recursos necessários para atender estes requisitos. As RSSF, muitas vezes, necessitam de uma arquitetura flexível e que estejam aptas a adaptar-se a alterações de projeto ou do próprio ambiente em que se encontram inserido. A utilização de arquiteturas reconfiguráveis é uma solução que introduz esta flexibilidade e uma grande capacidade de processamento ao nó-sensor. Comparando com as arquiteturas ASICs (Application Specific Integrated Circuit), as arquiteturas reconfiguráveis apresentam um custo reduzido no desenvolvimento de aplicações, visto que a plataforma não fica fixa a somente uma aplicação. A reconfigurabilidade permite um ganho no custo e tempo de projeto, além de possibilitar o desenvolvimento de plataformas genéricas para atender um número maior de aplicações. A proposta destas plataformas é, não apenas oferecer uma plataforma eficiente e flexível, mas também potencializar a aplicação em sistemas mais complexos que necessitem de uma maior capacidade de processamento. Este trabalho apresenta o desenvolvimento de um nó-sensor reconfigurável e customizável para RSSF denominado FemtoNode. O FemtoNode possui em sua plataforma reconfigurável um processador especificado a partir de uma linguagem orientada a objetos Java e um módulo de comunicação sem fio para suportar comunicação entre os nós da rede. A arquitetura proposta foi validada com o estudo de caso de uma rede de sensores heterogênea composta por nós-sensores com plataformas distintas, sendo a análise realizada na presente dissertação. / With the growth and the development of new applications for Wireless Sensor Networks (WSN), sensors nodes are able to handle more complex events that require higher processing performance and hardware flexibility. These new features are intended to meet the requirements of various applications, as well to provide customized platforms that have only the resources needed to meet these requirements. WSNs often need a flexible architecture able to adapt to design and environment changes. The use of reconfigurable architectures is an alternative to bring more flexibility and more processing capability for the sensor-node. Compared with ASICs (Application Specific Integrated Circuit) architectures, which have a high cost in production setup, reconfigurable architectures enable a reduction in these costs because its architecture is not fixed to a single application. Reconfigurability allows a gain in the project costs and time development, and it enables the development of generic platforms to deal with a greater number of applications. Therefore, the proposal target architecture that aims to provide a flexible and efficient platform that require greater processing capacity which support the development of applications. In this work a reconfigurable and customizable sensor-node called FemtoNode is proposed. The FemtoNode has a reconfigurable platform and a wireless module to support applications for WSNs, using an object-oriented language Java as specification language of its architecture. The proposed concepts were validated with a case study of an heterogeneous wireless sensor composed of sensors nodes with different platforms, whose results are described in this work.

Made available in DSpace on 2014-06-12T15:53:28Z (GMT). No. of bitstreams: 2 arquivo1916_1.pdf: 1434494 bytes, checksum: 1b590044040a8dcd13c8953148aade5a (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2009 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Constraint Handling Object-oriented Rules with Disjunctions (CHORD), é uma extensão orientada a objetos (OO) de CHRv, uma linguagem relacional baseada em regras que foi inicialmente desenhada para a especificação em caixa branca de resolvedores de restrições mas veio a mostrar-se uma linguagem bastante flexível. Flexibilidade esta que vêm sendo demonstrada nos últimos anos pelo grande número de serviços de raciocínio e algoritmos que foram descritos concisamente por meio desta linguagem. Para definir a sintaxe de nossa extensão, nós nos baseamos na abordagem seguida na extensão de Prolog realizada por Frame Logic que é similar à nossa, na qual, a sintaxe de frames foi introduzida para representar construtores OO em cima dos relacionais originais. Além disso, em vez de forçar o usuário (programador) a se adequar à uma semântica pré-definida para esses novos construtores, nós escolhemos uma estratégia inovadora: desacoplar a sintaxe da semântica da linguagem permitindo que o conjunto de hipóteses semânticas seja totalmente configurável. Estes avanços claramente contribuem para o domínio do Raciocínio Automático e da Representação do Conhecimento (AR/KR), dentro do qual CHRv é a linguagem de representa ção do conhecimento mais versátil. Este trabalho também permite a integração dos serviços de raciocínio já providos por CHRv ao estado da arte em linguagens orientadas a objetos reduzindo a quebra de paradigma entre elas. Há também contribuições a outros domínios: em programação declarativa, ao disponibilizar a primeira linguagem a integrar as formas mais poderosas de programação orientada a objetos, baseada em regras e baseada em restrições. No domínio da Web Semântica, nós mostramos que nossa linguagem generaliza a semântica de três dos mais importantes padrões de linguagem de representação do conhecimento, provendo uma solução para o problema recorrente de integração nesta área. No domínio da engenharia guiado por modelos (MDE), este trabalho provê o primeiro mapeamento semântico para modelos UML/OCL, MOF/OCL e transformações de modelo explícitamente configurável e com fundamentação axiomática declarativa e operacional em CFOL. Neste trabalho nós apresentamos as sintaxes abstrata e contreta de CHORD, suas semânticas operacional e declarativa em CFOL, e uma ontologia de hipóteses semânticas para herança. Para validá-lo, nós apresentamos três estudos de caso mostrando que CHORD generaliza UML/OCL, Frame Logic e OWL

Doctorat en philosophie et lettres / info:eu-repo/semantics/nonPublished

Doctor of Philosophy / Department of Secondary Education / Diane McGrath / The primary purpose of this study was to determine if a semi-automated reasoning tool that provides a set of searchable cases would improve a student’s understanding of the more difficult concepts in an object-oriented programming course. Also investigated were the relationships between the dependent variable student performance with independent variables of motivation, background knowledge, and student attitudes towards the semi-automated reasoning tool. Subjects for the study were randomly assigned from two sections of an introductory object-oriented programming course at an NCAA, Division II university in the Midwest region of the United States. Posttests were used to measure the effects of the semi-automated reasoning tool on learner competency. Background knowledge was collected through student transcripts. Motivation and student attitudes data were collected from surveys. All data were collected during the Spring 2005 semester. Data were analyzed at the p < .05 level of significance using a Wilcoxon Signed Ranks test, mixed-design ANOVA, Mann-Whitney U test, Spearman rho correlations, and thematic analysis as well as other statistical techniques. Results of the study indicated a significant difference between the group who used the semi-automated reasoning tool on complex questions and the group who did not. No significant difference was indicated between the groups on simple questions. A strong positive correlation was indicated between background knowledge and the total test scores for both content areas tested. Results of the correlational analysis between motivation and learner competencies indicated that the type of motivation, be it intrinsic or extrinsic, plays a minimal role in how students performed in this online course. Finally, students overwhelmingly felt that the semi-automated reasoning tool was an effective instructional-support tool. Results of this study suggested recommendations for practice as well as for further research. Recommendations for practice include the need for effective use of course management systems, supporting complex content through examples, using performance on background coursework when considering an online course covering complex topics, providing a case-based instructional aid for complex topics, and minimizing the economic costs in using a case-based instructional aid. Recommendations for future research include more research on relationships between background coursework and online courses, effects of a case-based instructional aid on face-to-face courses, development of overarching examples containing content from multiple computer science courses, improvements to the CBJava framework, and extending the framework to other disciplines.

A new distributed object-oriented discrete event-driven simulation environment, DODESE, is developed to provide a common framework for simulation model design and implementation. The DODESE can be used to define a simulation including all the simulation objects participating in the simulation while the execution of the simulation can be interactively monitored on DODESE. The DODESE system has combined the strengths of both object-oriented paradigms and data base technology to make computer simulation more powerful and has achieved the goals of object-orientation, distribution, reusability, maintainability and extensibility. The system runs on two Sun workstations concurrently connected by an Ethernet. One of the workstations performs the simulation tasks while the other workstation displays the status of the simulation interactively. Both workstations communicate through the GemStone data base, thus a mechanism is designed for synchronization and concurrency control. The DODESE is implemented using OPAL, GemStone’s data definition and manipulation language, C and Xlib.

We introduce a class of program editors that present a program using a rich set of transformations; we call these kinds of editors composable presentation editors. Proper use of these kinds of editors appears to lead to more expressive programs-programs whose structure are aligned with the problem they are trying to solve. By default, the composable presentation editor presents program elements textually as concrete syntax and enables typical editor commands on the program. Metadata on program elements control how the transformations are applied. Customized metadata can re-order, pictorialize, collapse, duplicate, or expand the displayed form of program elements and can additionally alter the available editor commands. We have developed a set of presentation techniques to be used by presentation designers (i.e., the programmers who design how a program is presented in the editor. These techniques relate to well-understood programming language design, editor design, and programming best-practices techniques including scoping, higher order functions, refactoring, prettyprinting, naming conventions, syntax highlighting, and text hovers. We introduce two implementations of composable presentation editors and a number of examples showing how programs can be made more expressive when presentation techniques are properly used. The first implementation is the ETMOP, an open editor, where a metaobject protocol is provided that allows language and editor designers to customize the way program elements are displayed. These customizations are called presenta- tion extensions and the corresponding presentation extension protocol acts in a way similar to the way that syntax macros extend the syntax of a language. The second implementation is Embedded CAL, a closed editor that uses these presentation techniques to embed one language (CAL) inside a host language (Java) through the use of presentation techniques, without changing the syntax or compiler of either language. / Science, Faculty of / Computer Science, Department of / Graduate

The path along which a high voltage cable needs to travel within the production facility is designed by a combination of straight and curved segments. As segments are available only in standard sizes, the path must be standardized. The transformation of an initial path into standardized path is a manual and time-consuming process. Tools are developed to automate this process using Knowledge-Based Engineering (KBE). The MOKA-methodology has been followed to capture and store the knowledge behind the standardization of the path. Designs of truss segments which are currently in use are studied and modified to make the models more efficient. Finite Element Analysis (FEA) is performed to evaluate the strength of segments of both old and new models which shows that new models are more efficient. To rapidly obtain segments of different dimensions, parametric models of segments are designed.

The use of Computer Aided Software Engineering (CASE) tools for teaching object-oriented systems analysis and design (OOSAD) has many potential benefits, but there are also several problems associated with the usage of these tools. A large portion of these problems relate to the usability and learnability of these tools. Learnability is one of the most important attributes of usability and refers to the capability of the system to enable the user to learn its application. The main research question that this study aims to address is “How can the learnability of OO CASE tools for computing education in South Africa be evaluated?”. In order to answer this question several frameworks for evaluating CASE tool usability and learnability were investigated. One of these frameworks, as proposed by Senapathi, was selected as being the most appropriate for evaluating CASE tool learnability for computing education. This framework maintains that the learnability of a CASE tool is dependent on context of use factors such as the tool used, as well as user characteristics such as gender. The primary aim of this research was thus to validate Senapathi's framework for CASE tool learnability in a South African context. A secondary aim of the research was to extend the implementation of the framework in order to enable the comparison of two CASE tools and to support the inclusion of other user characteristics. An experiment was performed at the Nelson Mandela Metropolitan University (NMMU) in 2006. The participants recruited for this experiment were second year computing students at NMMU. During this experiment, the learnability of two OO CASE tools, namely IBM's Rational Software Modeller and Microsoft's Visio, was evaluated and compared. The quantitative and qualitative results supported Senapathi's results and showed that her framework could be used to evaluate CASE tool learnability and could be adapted to evaluate two CASE tools. The results also showed that the majority of the participants rated the learnability of Microsoft Visio higher for both tasks and that the main reasons participants preferred Visio was due to its simplicity, familiarity and recoverability.