Web services intend to provide an application integration technology that can be successfully used over the Internet in a secure, interoperable and trusted manner. Policies are high-level guidelines defining the way an institution conducts its activities. The WS-Policy standard describes how to apply policies of security definition, enforcement of access control, authentication and logging. WS-Trust defines a security token service and a trust engine which are used by web services to authenticate other web services. Using the functions defined in WS-Trust, applications can engage in secure communication after establishing trust. BPEL is a language for web service composition that intends to provide convenient and effective means for application integration over the Internet. We address security considerations in BPEL and how to enforce them, as well as its interactions with other web services standards such as WS-Security and WS-Policy. / by Ola Ajaj. / Thesis (M.S.C.S.)--Florida Atlantic University, 2010. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2010. Mode of access: World Wide Web.

The purpose of this project to develope a network syslog monitoring system to monitor network devices like printers, switches, etc. and to help the network technical help desk personnel to handle issues promptly and effectively based on the syslog messages captured by the syslog server.

Processing and optimizing ad-hoc and continual queries in an open environment with distributed, autonomous, and heterogeneous data servers (e.g., the Internet) pose several technical challenges. First, it is well known that optimized query execution plans constructed at compile time make some assumptions about the environment (e.g., network speed, data sources' availability). When such assumptions no longer hold at runtime, how can I guarantee the optimized execution of the query? Second, it is widely recognized that runtime adaptation is a complex and difficult task in terms of cost and benefit. How to develop an adaptation methodology that makes the runtime adaptation beneficial at an affordable cost? Last, but not the least, are there any viable performance metrics and performance evaluation techniques for measuring the cost and validating the benefits of runtime adaptation methods? To address the new challenges posed by Internet query and search systems, several areas of computer science (e.g., database and operating systems) are exploring the design of systems that are adaptive to their environment. However, despite the large number of adaptive systems proposed in the literature up to now, most of them present a solution for adapting the system to a specific change to the runtime environment. Typically, these solutions are not easily ``extendable' to allow the system to adapt to other runtime changes not predicted in their approach. In this dissertation, I study the problem of how to construct a framework where I can catalog the known solutions to query processing adaptation and how to develop an application that makes use of this framework. I call the solution to these two problems the Ginga approach. I provide in this dissertation three main contributions: The first contribution is the adoption of the Adaptation Space concept combined with feedback-based control mechanisms for coordinating and integrating different kinds of query adaptations to different runtime changes. The second contribution is the development of a systematic approach, called Ginga, to integrate the adaptation space with feedback control that allows me to combine the generation of predefined query plans (at compile-time) with reactive adaptive query processing (at runtime), including policies and mechanisms for determining when to adapt, what to adapt, and how to adapt. The third contribution is a detailed study on how to adapt to two important runtime changes, and their combination, encountered during the execution of distributed queries: memory constraints and end-to-end delays.

see PDF

This thesis presents an approach to design, specify, validate, verify, implement, and evaluate composed web/grid services. Web and grid services can be composed to create new services with complex behaviours. The BPEL (Business Process Execution Language) standard was created to enable the orchestration of web services, but there have also been investigation of its use for grid services. BPEL specifies the implementation of service composition but has no formal semantics; implementations are in practice checked by testing. Formal methods are used in general to define an abstract model of system behaviour that allows simulation and reasoning about properties. The approach can detect and reduce potentially costly errors at design time. CRESS (Communication Representation Employing Systematic Specification) is a domainindependent, graphical, abstract notation, and integrated toolset for developing composite web service. The original version of CRESS had automated support for formal specification in LOTOS (Language Of Temporal Ordering Specification), executing formal validation with MUSTARD (Multiple-Use Scenario Testing and Refusal Description), and implementing in BPEL4WS as the early version of BPEL standard. This thesis work has extended CRESS and its integrated tools to design, specify, validate, verify, implement, and evaluate composed web/grid services. The work has extended the CRESS notation to support a wider range of service compositions, and has applied it to grid services as a new domain. The thesis presents two new tools, CLOVE (CRESS Language-Oriented Verification Environment) and MINT (MUSTARD Interpreter), to respectively support formal verification and implementation testing. New work has also extended CRESS to automate implementation of composed services using the more recent BPEL standard WS-BPEL 2.0.

Thesis (MPhil)--University of Stellenbosch, 2006. / On title page: Master of Philosophy (Information and Knowledge Management). Bibliography. Also available via the Internet.

Thesis (MPhil)--Stellenbosch University, 2005. / ENGLISH ABSTRACT: Prior to the invention of Personal Computers the scope of research activities was limited by the pre-existing capabilities of problem solving mechanisms. However, with the advent of PCs and inter-networking thereof, the new tools (hardware and software) enabled the scientific community to tackle more complex research challenges and this led to a better understanding of our environment. The development of the Internet also enabled research communities to communicate and share information in real time. However, even the Internet has limitations of its own when it comes to the need of sharing not only information but also massive storage, processing power, huge databases and applications, expensive and delicate scientific instruments, knowledge and expertise. This led to the need for a networking system that includes these above-mentioned services, using the Internet infrastructure, semantic web technologies and pervasive computing devices, which is so called Grid Computing. This research study deals with a Generic Campus Grid Computing framework, which mobilizes the available idle/extra computing resources residing in the faculty-computing centres for use by the e-community on CPU-intensive or Data-intensive jobs. This unused computing capacity could be utilized for Grid computing services; hence, the already available resources could be more efficiently exploited. Besides, this could be a huge saving when compared to the cost of acquiring supercomputers by these institutions. Therefore, this research study intends to establish a simple and functional Generic Campus Grid Computing Framework at this stage, with the consent that subsequent research studies could deal with further assessment in a more detailed perspective and practical implementation thereof. / AFRIKAANSE OPSOMMING: Voor die uitvinding van die Persoonlike Rekenaar is die omvang van navorsingsaktiwiteite beperk deur die voorafbestaande vermoëns van probleemoplossingsmeganismes. Met die verskyning van PR's en die daaropvolgende internetwerking daarvan, het die nuwe gereedskap (hardeware en sagteware) die wetenskaplike gemeenskap in staat gestel om meer komplekse navorsingsuitdagings aan te pak. Dit het gelei tot groter begrip van ons omgewing. Die onwikkeling van die Internet het navorsingsgemeenskappe ook in staat gestel om in reële tyd te kommunikeer en inligting te deel. Nietemin, selfs die Internet het gebreke wanneer dit kom by die behoefte om nie slegs inligting te deel nie, maar ook massiewe stoorruimte, verwerkingskrag, baie groot databasisse en toepassings, duur en delikate wetenskaplike toerusting, kennis en kundigheid. Dit het gelei tot die behoefte aan 'n netwerksisteem wat bogenoemde dienste insluit, deur gebruik te maak van Internet-infrastruktuur, semantiese web tegnologieë, en alomteenwoordige rekenaartoestelle. Hierdie sisteem staan bekend as "Grid Computing" of te wel Rooster Komputasie. Hierdie navorsingstudie handel oor 'n Generiese Kampus Rooster Komputasie Raamwerk wat die ongebruikte, ekstra komputasiebronne, wat beskikbaar is in fakulteite se rekenaargebruikersareas, mobiliseer vir gebruik deur die e-gemeenskap op SVE-intensiewe of Dataintensiewe toepassings. Hierdie ongebruikte komputasie kapasiteit kan aangewend word vir Rooster komputasie dienste; gevolglik kan die beskikbare bronne dan meer effektief benut word. Verder kan dit lei tot groot besparings wanneer dit vergelyk word met die koste om superrekenaars aan te koop deur die betrokke instansies. Dus, op hierdie stadium stel hierdie navorsingstudie dit ten doel om 'n eenvoudige en funksionele Generiese Kampus Rooster Komputasie Raamwerk te skep met dien verstande dat daaropvolgende studies sou kon fokus op verdere assessering met 'n meer gedetaileerde perspektief en met praktiese implementasie.

Orientador: Paulo Cesar Centoducatte / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Computação / Made available in DSpace on 2018-08-05T00:50:23Z (GMT). No. of bitstreams: 1 Baldassin_Alexandro_M.pdf: 957897 bytes, checksum: 02ca08a95301bf7e9262564a9672c8b4 (MD5) Previous issue date: 2005 / Resumo: Projetistas de sistemas dedicados enfrentam atualmente novos desafios em todas as fases do projeto. A difusão da tecnologia conhecida como SoC (System on a Chip) requer novos paradigmas para a especificação, implementação e verificação do projeto. A alta complexidade de tais sistemas e a grande variedade de configurações disponíveis podem tornar a escolha do sistema ideal demorada, prolongando o tempo de projeto e conseqüentemente seu ingresso no mercado. Em especial, no processo de escolha de um certo processador, o projetista necessita de um conjunto básico de ferramentas que lhe permitam analisar questões como desempenho, potência consumida, ou ainda área de silício ocupada. Exemplos de ferramentas importantes nessa fase de avaliação do projeto incluem compiladores, montadores e simuladores de instruções. Nesse contexto, o uso de uma linguagem para descrição de arquitetura (Architecture Description Language, ADL) permite que processadores sejam modelados em níveis altos de abstração, e que um conjunto de ferramentas específicas para o modelo descrito seja gerado automaticamente. ArchC é uma ADL em desenvolvimento no Laboratório de Sistemas de Computação (IC-UNICAMP), e já é capaz de gerar ferramentas de simulação de instruções automaticamente. Desenvolvemos neste trabalho uma ferramenta para geração automática de montadores a partir de modelos descritos em ArchC, denominada acasm 2. O desenvolvimento de acasm nos levou a incorporar novas construções a ArchC para a modelagem da linguagem de montagem e da codificação das instruções. Nossa ferramenta gera um conjunto de arquivos dependentes de arquitetura para o redirecionamento do montador GNU Assembler (gas). Usamos acasm para gerar montadores a partir de modelos, em ArchC, das arquiteturas MIPS-I e SPARC-V8, e comparamos os arquivos objetos obtidos com os gerados pelo montador gas nativo para ambas arquiteturas. Os resultados mostraram que os arquivos gerados pelo nosso montador foram idênticos aos gerados pelo montador nativo para ambas arquiteturas / Abstract: Nowadays, embedded systems designers are facing new challenges at all stages of the design process. The growing of the system-on-chip (SoC) technology is creating new paradigms in the specification, implementation and verification phases of a design. The increasing complexity and the myriad of available configurations make it hard to choose the ideal system, therefore lengthening the design time, as well as time to market. Specially, customization of the processor architecture requires a software toolkit in order to estimate factors such as performance, power dissipation and chip area. Examples of these tools may include compilers, assemblers and instruction level simulators. In this context, the use of an architecture description language (ADL) allows one to model processors using different levels of abstraction. Based on the model, a software toolkit can be automatically generated. ArchC is an ADL being developed by the Computer Systems Laboratory (IC-UNICAMP) and can automatically generate instruction level simulators at its current stage. In this work, we have created a tool to automatically generate assemblers from ArchC models, named acasm 3. While developing acasm we have introduced new language constructions to ArchC in order to describe the assembly language syntax and the instruction encoding scheme. Our tool retargets the GNU assembler (gas) to different architectures by generating a set of architecture depedent files based on ArchC models. We used acasm to generate assemblers to the MIPS-I and SPARC-V8 architectures based on our ArchC models. We then compared the object files created by our assemblers with the ones created by the native gas and no difference between each pair of files was noticed, for both architectures / Mestrado / Mestre em Ciência da Computação

Thesis: M.S., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 1978 / Bibliography: leaves 87-89. / by Seymour A. Danberg. / M.S. / M.S. Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science

Submitted in fulfillment of the requirements for the degree of Doctor of Technology, Information Technology, Durban University of Technology, 2012. / This thesis reports on original exploratory study that is aimed at contributing towards understanding of factors that influence Africa users support for alternative object metaphors for user interface icons. One of the great impediments for efficient utilization of information systems is the existing gap between system designs that typically follow western cues for crafting user interfaces and actual users who use those systems within their diverse cultural frames. The problem remains important because of the wider penetration of information systems, which serve as modern technology tools to improve service provisioning worldwide. In order to overcome the problem of optimum utilization of information systems, previous studies have proposed culturally adaptive user interfaces. The basic principle behind culture adaptive interfaces is to develop intelligent user interfaces that can automatically adapt to user contexts. However, the challenges with the new proposals for adaptive user interfaces are how to best model information about users, how to access the cultural background of individual users and empirically examine the effects of culture on user interface preferences. In order to properly contribute to solving these problems, an exploratory study was conducted to empirically establish African rural users support for alternative village object metaphors, examine effects of culture on user support and investigate response characteristic among culturally diverse user groups. The synthesis of bodystorming and cultural probes methodology was applied to engage the participation of African rural users in the study. Technology support model was developed to measure user knowledge, comprehension, skills, performance and support for alternative African village metaphors as interface icons. The partial least square analytic modelling technique and finite mixture path segmentation model were used to test a set of research hypotheses and detect heterogeneity in 71 respondent data generated. Experimental results of this study show that human cognitive factors of technology knowledge, comprehension and performance influence African users support for alternative village object metaphors as interface icons. However, skill factor is not found to influence user support for alternative African village object metaphors. The factor of culture is found to moderate the effects of comprehension on user support and effects of user performance on user support. This study also identifies three segments of African users that result in heterogeneity within the inner path model.