Thesis (M.Tech.: Computer Studies)-Dept. of Computer Science, Durban Institute of Technology, 2002. / Computer programming has been a science for approximately 50 years. It this time there havebeen two major paradigm shifts that have taken place. The first was from “spaghetti code” to structured programs. The second paradigm shift is from procedural programs to object oriented programs. The change in paradigm involves a change in the way in which a problem is approached, can be solved, as well as a difference in the language that is used. The languages that were chosen to be studied, are COBOL and Java. These programming languages were identified as key languages, and the languages that software development are the most reliant on. COBOL, the procedural language for existing business systems, and Java the object oriented language, the most likely to be used for future development. To complete this study, both languages were studied in detail. The similarities and differences between the programming languages are discussed. Some key issues that a COBOL programmer has to keep in mind when moving to Java were identified.

Thesis (MSc)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: In this dissertation we present a software tool, Artemis, that symbolically executes Java virtual machine bytecode to find bugs and automatically generate test cases to trigger the bugs found. Symbolic execution is a technique of static software analysis that entails analysing code over symbolic inputs—essentially, classes of inputs—where each class is formulated as constraints over some input domain. The analysis then proceeds in a path-sensitive way adding the constraints resulting from a symbolic choice at a program branch to a path condition, and branching non-deterministically over the path condition. When a possible error state is reached, the path condition can be solved, and if soluble, value assignments retrieved to be used to generate explicit test cases in a unit testing framework. This last step enhances confidence that bugs are real, because testing is forced through normal language semantics, which could prevent certain states from being reached. We illustrate and evaluate Artemis on a number of examples with known errors, as well as on a large, complex code base. A preliminary version of this work was successfully presented at the SAICSIT conference held on 1–3 October 2012, in Centurion, South Africa. / AFRIKAANSE OPSOMMING: In die dissertasie bied ons ’n stuk sagtewaregereedskap, Artemis, aan wat biskode van die Java virtuele masjien simbolies uitvoer om foute op te spoor en toetsgevalle outomaties voort te bring om die foute te ontketen. Simboliese uitvoering is ’n tegniek van statiese sagteware-analise wat behels dat kode oor simboliese toevoere—in wese, klasse van toevoer—geanaliseer word, waar elke klas geformuleer word as beperkinge oor ’n domein. Die analise volg dan ’n pad-sensitiewe benadering deur die domeinbeperkinge, wat volg uit ’n simboliese keuse by ’n programvertakking, tot ’n padvoorwaarde by te voeg en dan nie-deterministies vertakkings oor die padvoorwaarde te volg. Wanneer ’n moontlike fouttoestand bereik word, kan die padvoorwaarde opgelos word, en indien dit oplaasbaar is, kan waardetoekennings verkry word om eksplisiete toetsgevalle in ’n eenheidstoetsingsraamwerk te formuleer. Die laaste stap verhoog vertroue dat die foute gevind werklik is, want toetsing word deur die normale semantiek van die taal geforseer, wat sekere toestande onbereikbaar maak. Ons illustreer en evalueer Artemis met ’n aantal voorbeelde waar die foute bekend is, asook op ’n groot, komplekse versameling kode. ’n Voorlopige weergawe van die´ werk is suksesvol by die SAICSIT-konferensie, wat van 1 tot 3 Oktober 2012 in Centurion, Suid-Afrika, gehou is, aangebied.

Orientador: Paulo Lício de Geus / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Computação / Made available in DSpace on 2018-10-08T19:16:40Z (GMT). No. of bitstreams: 1 Afonso_VitorMonte_M.pdf: 1149302 bytes, checksum: 7db349dd13a346a3b3e7175d2f7eeaae (MD5) Previous issue date: 2011 / Resumo: Páginas Web com conteúdo malicioso são uma das grandes ameaças à segurança de sistemas atualmente. Elas são a principal forma utilizada por atacantes para instalar programas maliciosos (malware) no sistema operacional dos usuários. Para desenvolver mecanismos de proteção contra essas páginas, elas precisam ser estudadas e entendidas profundamente. Existem diversos sistemas de análise que são capazes de analisar páginas Web, prover informações sobre elas e classificá-las como maliciosas ou benignas. Entretanto, estes sistemas possuem diversas limitações em relação ao tipo de código que pode ser analisado e aos tipos de ataque que podem ser detectados. Para suprir tal deficiência nos sistemas de análise de páginas Web maliciosas foi desenvolvido um sistema, chamado de BroAD (Browser Attacks Detection), que faz a análise destas páginas de forma dinâmica, monitorando tanto as chamadas de sistemas realizadas pelo navegador enquanto as processa, quanto as ações realizadas pelo código JavaScript contido na página. A detecção dos comportamentos maliciosos é feita em quatro etapas, utilizando técnicas de aprendizado de máquina e assinaturas. Estas etapas incluem a detecção de shellcodes, a detecção de anomalias no comportamento do JavaScript e a análise de chamadas de sistema e assinaturas de código JavaScript. Foram realizados testes que demonstram que o sistema desenvolvido possui taxas de detecção superiores aos sistemas do estado-da-arte de análise de páginas Web maliciosas e ainda provê mais informações a respeito delas, levando a um entendimento melhor das amostras. Além disso, são apresentados códigos que podem detectar e evadir facilmente a análise de parte desses sistemas usados na comparação, demonstrando a fragilidade deles / Abstract: Malicious Web applications are a significant threat to computer security today. They are the main way through which attackers manage to install malware on end-user systems. In order to develop protection mechanisms to these threats, the attacks themselves need to be deeply studied and understood. Several analysis systems exist to analyze Web pages, provide information about them and classify them as malicious or benign. However, these systems are limited regarding the type of attacks that can be detected and the programming languages that can be analyzed. In order to fill this gap, a system, called BroAD (Browser Attacks Detection), that is capable of analyzing malicious Web pages, was developed. It monitors both system calls and JavaScript actions and the detection of the malicious behavior is performed in four steps, by the use of machine learning techniques and signatures. These steps include the detection of shellcodes, the anomaly detection of the JavaScript behavior and the analysis of system calls and JavaScript signatures. The results of the performed tests show that the developed system has better detection rates than the state-of-the-art systems in malicious Web pages analysis and also provides more information about these pages, giving a better understanding about their behavior. Besides, codes that can be used to easily detect and evade the analysis of part of those systems are presented, showing their fragility / Mestrado / Ciência da Computação / Mestre em Ciência da Computação

Thesis (M.Tech.: Computer Studies)-Dept. of Computer Science, Durban Institute of Technology, 2002. / Computer programming has been a science for approximately 50 years. It this time there havebeen two major paradigm shifts that have taken place. The first was from “spaghetti code” to structured programs. The second paradigm shift is from procedural programs to object oriented programs. The change in paradigm involves a change in the way in which a problem is approached, can be solved, as well as a difference in the language that is used. The languages that were chosen to be studied, are COBOL and Java. These programming languages were identified as key languages, and the languages that software development are the most reliant on. COBOL, the procedural language for existing business systems, and Java the object oriented language, the most likely to be used for future development. To complete this study, both languages were studied in detail. The similarities and differences between the programming languages are discussed. Some key issues that a COBOL programmer has to keep in mind when moving to Java were identified.

Thesis (M.App.Sc.) - Carleton University, / Includes bibliographical references (p. 82-88). Also available in electronic format on the Internet.

The capacity to engage in web services transactions on smartphones is growing as these devices become increasingly powerful and sophisticated. This capacity for mobile web services is being realised through mobile applications that consume web services hosted on larger computing devices. This thesis investigates the effect that end-to-end web services security has on the interoperability between mobile web services requesters and traditional web services providers. SOAP web services are the preferred web services approach for this investigation. Although WS-Security is recognised as demanding on mobile hardware and network resources, the selection of appropriate WS-Security mechanisms lessens this burden. An attempt to implement such mechanisms on smartphones is carried out via an experiment. Smartphones are selected as the mobile device type used in the experiment. The experiment is conducted on the Java Micro Edition (Java ME) and the .NET Compact Framework (.NET CF) smartphone platforms. The experiment shows that the implementation of interoperable, end-to-end, mobile web services security on both platforms is reliant on third-party libraries. This reliance on third-party libraries results in poor developer support and exposes developers to the complexity of cryptography. The experiment also shows that there are no standard message size optimisation libraries available for both platforms. The implementation carried out on the .NET CF is also shown to rely on the underlying operating system. It is concluded that standard WS-Security APIs must be provided on smartphone platforms to avoid the problems of poor developer support and the additional complexity of cryptography. It is recommended that these APIs include a message optimisation technique. It is further recommended that WS-Security APIs be completely operating system independent when they are implemented in managed code. This thesis contributes by: providing a snapshot of mobile web services security; identifying the smartphone platform state of readiness for end-to-end secure web services; and providing a set of recommendations that may improve this state of readiness. These contributions are of increasing importance as mobile web services evolve from a simple point-to-point environment to the more complex enterprise environment.

Orientador: Walter da Cunha Borelli / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-14T06:48:35Z (GMT). No. of bitstreams: 1 Rezende_DanielCesarFelisberto_M.pdf: 1288199 bytes, checksum: f1529cd12e6f799944821614b3c9750c (MD5) Previous issue date: 2009 / Resumo: Este trabalho apresenta uma proposta de especificação formal em SDL de uma rede de comunicação intraveicular baseada no protocolo de comunicação FlexRay com geração automática de código Java. O modelo proposto se baseia naquele apresentado na especificação padrão do protocolo FlexRay, porém algumas contribuições foram feitas a fim de gerar uma rede FlexRay funcional e executável. O modelo SDL gerado confere uma formalização comportamental ao sistema, permitindo a sua validação e a simulação de suas principais funcionalidades e casos críticos através da ferramenta SDL TAU Suite. Depois de o sistema ser modelado, simulado e validado é gerado código Java para execução do sistema criado. Para isso, foi desenvolvida uma ferramenta geradora de código Java que recebe como entrada um arquivo com as especificações em SDL e tem-se como resultado um sistema descrito em Java que faz uso de sockets para comunicação entre os processos. / Abstract: This work presents a proposal of formal specification using SDL for an in-vehicle network based on the FlexRay protocol with automatic generation of Java code. The proposed model is based on that presented in the standard specification of the FlexRay protocol, although some contributions were made in order to generate a functional and executable FlexRay network. The SDL model generated provides the system a behavioural formalization, making it possible to validate and simulate its key features and critical cases by the use of the tool TAU SDL Suite. After the system is modeled, simulated and validated is generated Java code for implementing the system created. For this reason it was developed a tool for generating Java code that receives as input a file with the specifications in SDL, and delivers as result a system written in Java that makes use of sockets for communication between processes. / Mestrado / Telecomunicações e Telemática / Mestre em Engenharia Elétrica

Orientador: Enrique Ortega Rodriguez / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-08T11:41:59Z (GMT). No. of bitstreams: 1 Takahashi_Fabio_M.pdf: 1666534 bytes, checksum: e3f3856c1777c40bd5655d85ba32fcef (MD5) Previous issue date: 2007 / Resumo: Este trabalho teve como objetivo o desenvolvimento de ferramentas computacionais para a realização da avaliação emergética de sistemas agrícolas utilizando as tecnologias XML, XSLT, Java, JSP, Struts e banco de dados MySQL. Na primeira etapa do trabalho, foram desenvolvidos documentos XML para representar os sistemas de agricultura química da Flórida e do Brasil. Um arquivo XSLT foi criado para processar e calcular o fluxo de emergia para cada recurso e visualizar os resultados utilizando o navegador Internet Explorer. As informações registradas nos arquivos XML são: tipo de recurso (contribuição da natureza e da economia humana), quantidade utilizada, unidade de medida, fator de conversão de unidades e transformidades solares. A análise emergética dos sistemas agrícolas pode ser feita de maneira fácil, através da modificação dos campos ¿quantidade de recursos utilizados¿ nos arquivos XML. Na segunda etapa um aplicativo java foi desenvolvido para abrir os arquivos XML e modificar esses campos. Na terceira etapa foram desenvolvidas páginas web dinâmicas utilizando-se as tecnologias JSP e Struts. Com esta ferramenta o usuário pode escolher o sistema, alterar os valores dos recursos utilizados, gravar esses dados no banco de dados e visualizar os resultados. As principais conclusões deste trabalho são: (a) a utilização da tecnologia XML e Java facilita a análise emergética dos sistemas agrícolas; (b) disponibilizando estas ferramentas na internet, o diagnóstico emergético pode ser difundido e amplamente utilizado, sem perder seus padrões de qualidade; (c) esta metodologia pode ser adaptada para representar todos os sistemas agrícolas brasileiros, incluindo os modelos ecológicos como também os químicos / Abstract: This work had the goal of developing computational tools to make the emergy evaluation of agricultural systems using the technologies XML, XSLT, Java, JSP, Struts and the MySQL database. At the first stage of this work, XML documents were developed to represent the chemical agricultural systems of Florida and Brazil. A XSLT archive was created to process and to calculate the emergy flows for each resource and to visualize the results using the Internet Explorer Navigator. The information stored on the XML archives are: type of resources (contribution of nature and economy), amount used, units of measure, units conversion factors and solar transformities. The emergy analysis of agricultural systems can be done in an easy way, through the modification of the ¿quantity of resources used¿ fields on the XML archives. At the second stage, a java application was developed to open the XML archives and to modify these fields. At the third stage dynamic web pages were developed using the technologies JSP and Struts. With this tool the user can choose the system, modify the values of used resources, save these data on the database and visualize the results. The main conclusions of this work are: (a) the use of XML and Java technologies make easier the emergy analysis of agricultural systems; (b) making these tools available at the internet, the emergy diagnosis can be spread out and widely used, without losing its quality standards; (c) these methodologies can be adapted to represent all the Brazilian agricultural systems, including the ecological models as well as the chemical models / Mestrado / Engenharia de Alimentos / Mestre em Engenharia de Alimentos

Orientadores: Eduardo Tavares Cost, Marden Leonardi Lopes / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-11T20:29:41Z (GMT). No. of bitstreams: 1 Ferreira_LeticiaAlves_M.pdf: 5085906 bytes, checksum: 14376ec37e81ed3a052c5ee7d1858799 (MD5) Previous issue date: 2008 / Resumo: Os scanners ultra-sônicos atuais oferecem ferramentas específicas para estudos de Ecocardiografia do Miocárdio por Contraste de Microbolhas (ECM) e apesar do potencial comprovado para a análise quantitativa não invasiva da perfusão miocárdica, seu uso se restringe praticamente à interpretação qualitativa (visual) das imagens clínicas. O objetivo desta tese foi desenvolver e criar uma aplicação stand-alone multiplataforma baseada nos algoritmos criados por Lopes (2005) e implementados em seu protótipo MCEToolRS. A aplicação proposta, denominada JMCETool, tem como principais características ser de fácil utilização e não comprometer a precisão, exatidão e robustez nos processos que envolvem a quantificação da perfusão miocárdica. Assim como no protótipo desenvolvido, os principais algoritmos do processo de quantificação são: o alinhamento automático baseado em Template Matching, técnicas de busca rápida e correlação; a colocação automática das ROIS sobre a parede do miocárdio; e a quantificação da perfusão miocárdica. Entre as diferenças do protótipo desenvolvido em Matlab® e da aplicação desenvolvida em Java, destacam-se a criação de uma interface mais amigável ao usuário, a implantação de uma arquitetura de software, melhor tratamento de exceções e uma nova forma de correção manual do alinhamento das imagens. A aplicação foi testada com 15 seqüências de ECM (288 imagens), sendo 14 seqüências provenientes de estudos com animais e uma proveniente de estudos com humanos. Os resultados obtidos são comparáveis aos obtidos por Lopes (2005), testes quantitativos demonstraram precisão média no processo de alinhamento de 1 pixel (para translação) e 1 grau (para rotação), com exatidão aproximada de ± 1 pixel e de ± 1 grau. / Abstract: Current commercial ultrasound scanners incorporate tools for Myocardial Contrast Echocardiography (MCE) and techniques which have a great potential for non-invasive quantitative myocardial perfusion analysis, although its use is practically restricted to qualitative (visual) reading of clinical data. The objective of this thesis was to create a new easy-to-use multiplatform standalone application for quantification of myocardium perfusion in a MCE sequence of images based on the algorithms developed by Lopes (2005) and their implementation, the prototype, called MCEToolRS. The main objective of the proposed application, called JMCETool, is the execution of these algorithms with no loss of precision, accuracy and robustness of the quantification process, compared to the first prototype. The main algorithms of the quantification process are: the automatic alignment, based on Template Matching, fast search algorithms and correlation; the automatic ROI's placement over the myocardium wall; and the quantification of myocardium perfusion. Among other features, compared to the prototype, the application JMCETool handles the algorithms exceptions and has a more user-friendly interface, including changes in the interface for manual alignment. Fifteen MCE sequences (288 images) were used during the application trials. Fourteen out of fifteen sequences belong to studies with animals (dogs) and only one belongs to studies with humans. Performance tests demonstrated that our results were similar to those of Lopes (2005), Quantitative tests have shown mean precision of 1 pixel (translation) and 1 degree (rotation) in the alignment process, and accuracy around ± 1 pixel and ± 1 degree. / Mestrado / Engenharia Biomedica / Mestre em Engenharia Elétrica

Orientador: Ivan Luiz Marques Ricarte / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-04T04:08:09Z (GMT). No. of bitstreams: 1 Martins_DaltonLopes_M.pdf: 1278026 bytes, checksum: b7c0e45069a357920387e022e4bc3f77 (MD5) Previous issue date: 2004 / Resumo: O suporte à colaboração e as redes P2P (peer-to-peer) tem sido dois assuntos que, por muitos momentos, se cruzam no estudo e na pesquisa do uso das novas tecnologias em ambientes colaborativos de aprendizado. O presente estudo trata das motivações sociais e técnicas para o uso das redes P2P como um suporte ao trabalho colaborativo entre grupos. Inicialmente, realizamos um estudo das características de uso e da mudança de paradigmas de trabalho em rede que o P2P nos fornece. Como base de aplicação prática deste trabalho, também apresentamos um estudo de protocolos e sistemas computacionais já existentes que tratam, de alguma forma, da questão da colaboração através de redes P2P. Por final, com base no estudo apresentado, elaboramos a especificação e a implementação de um sistema de colaboração, o SemiCode, de forma a validar algumas das idéias desenvolvidas neste trabalho, além de apresentarmos algumas soluções onde o P2P pode atuar em conjunto com sistemas cliente-servidor / Abstract: The support to the collaboration and P2P network are two related subjects in the study and research involving new technologies for collaboratives learning environments. The present study deals with social motivations and techniques for the use of P2P nets as a support to the collaborative work. Initially, we carry through a study of the characteristics of use and the change of paradigms of work in net P2P supplies. Supporting the development of a application in this work, also we present a study of protocols and existing computational systems that, in some way, deal with collaboration through P2P nets. Finally, based on this study, we elaborate the specification and the implementation of a collaborative system, the SemiCode, wich validates some of these ideas. We also present some solutions based on the integra from between P2P and client-server systems / Mestrado / Engenharia de Computação / Mestre em Engenharia Elétrica