Made available in DSpace on 2015-04-14T14:49:24Z (GMT). No. of bitstreams: 1 424471.pdf: 3818721 bytes, checksum: d6fbd6820f37d0e5f23b429ebe486f73 (MD5) Previous issue date: 2010-03-12 / Atualmente, diversos servi?os s?o disponibilizados pela Internet e h? uma crescente demanda por estas aplica??es. Considerando que a Internet n?o ? uma rede segura, a confidencialidade de informa??es que circulam na rede ? um fator de import?ncia cada vez maior. Visando solucionar este problema, v?rias t?cnicas de seguran?a surgiram e cada empresa as adotou em suas pol?ticas de uma forma diferente. Por?m com a tend?ncia de ado??o do modelo de Arquiteturas Orientadas a Servi?os, diferentes servi?os com diferentes pol?ticas de seguran?a necessitaram ser agrupados para que pudessem trabalhar em conjunto, o que acabou dificultando a cria??o de uma aplica??o que segue um determinado padr?o. Uma nova abordagem se faz necess?ria para facilitar a coexist?ncia destas t?cnicas de seguran?a de uma forma produtiva. Assim, este trabalho apresenta um modelo voltado ao tratamento autom?tico de caracter?sticas de seguran?a para servi?os ordenados em Arquiteturas Orientadas a Servi?o. Este modelo atua como um sistema intermedi?rio capaz de traduzir as t?cnicas de seguran?a para um formato determinado. Com base neste modelo ? apresentado um prot?tipo capaz de tratar automaticamente diferentes algoritmos de criptografia assim?trica, entre eles RSA, DSA e ECDSA. O objetivo do trabalho ? testar a efetividade do modelo por meio de um estudo de caso, apresentando uma situa??o que este pode ser adotado por aplica??es reais.

Information monitoring systems are publish-subscribe systems that continuously track information changes and notify users (or programs acting on behalf of humans) of relevant updates according to specified thresholds. Internet-scale information monitoring presents a number of new challenges. First, automated change detection is harder when sources are autonomous and updates are performed asynchronously. Second, information source heterogeneity makes the problem of modelling and representing changes harder than ever. Third, efficient and scalable mechanisms are needed to handle a large and growing number of users and thousands or even millions of monitoring triggers fired at multiple sources. In this dissertation, we model users' monitoring requests using continual queries (CQs) and present a suite of efficient and scalable solutions to large scale information monitoring over structured or semi-structured data sources. A CQ is a standing query that monitors information sources for interesting events (triggers) and notifies users when new information changes meet specified thresholds. In this dissertation, we first present the system level facilities for building an Internet-scale continual query system, including the design and development of two operational CQ monitoring systems OpenCQ and WebCQ, the engineering issues involved, and our solutions. We then describe a number of research challenges that are specific to large-scale information monitoring and the techniques developed in the context of OpenCQ and WebCQ to address these challenges. Example issues include how to efficiently process large number of continual queries, what mechanisms are effective for building a scalable distributed trigger system that is capable of handling tens of thousands of triggers firing at hundreds of data sources, how to effectively disseminate fresh information to the right users at the right time. We have developed a suite of techniques to optimize the processing of continual queries, including an effective CQ grouping scheme, an auxiliary data structure to support group-based indexing of CQs, and a differential CQ evaluation algorithm (DRA). The third contribution is the design of an experimental evaluation model and testbed to validate the solutions. We have engaged our evaluation using both measurements on real systems (OpenCQ/WebCQ) and simulation-based approach. To our knowledge, the research documented in this dissertation is to date the first one to present a focused study of research and engineering issues in building large-scale information monitoring systems using continual queries.

Personal home pages are outgrowing their playful beginnings to serve serious purposes. At the forefront of this emergence is academia, where they are becoming a meaningful way for researchers to engage each other. Yet, the medium is still in its infancy: The medium, its adopters, and their practices are unduly constrained by current technology. To better study the meaning and use of personal home pages in academia, I created the AniAniWeb personal-home-page system to loosen these constraints. AniAniWeb applies wiki technology to facilitate easy editing, to enable interaction, and to focus the user on content creation. Others began adopting AniAniWeb in fall 2003. This dissertation centers on a case study of six graduate students and their experience with AniAniWeb over a period of two years. Their practices are viewed through three analytical lenses. Media theory focuses on the technology. Communities of practice focuses on the social context. Core identity theory focuses on the individual. When combined, these frameworks lead to a rich understanding of personal home pages in academia. Based on observations and interviews, issues of design, technology, meaning, and use are addressed.

As web applications occupy an increasingly important role in the day-to-day lives of millions of people, testing and analysis techniques that ensure that these applications function with a high level of quality are becoming even more essential. However, many software quality assurance techniques are not directly applicable to modern web applications. Certain characteristics, such as the use of HTTP and generated object programs, can make it difficult to identify software abstractions used by traditional quality assurance techniques. More generally, many of these abstractions are implemented differently in web applications, and the lack of techniques to identify them complicates the application of existing quality assurance techniques to web applications. This dissertation describes the development of program analysis techniques for modern web applications and shows that these techniques can be used to improve quality assurance. The first part of the research focuses on the development of a suite of program analysis techniques that identifies useful abstractions in web applications. The second part of the research evaluates whether these program analysis techniques can be used to successfully adapt traditional quality assurance techniques to web applications, improve existing web application quality assurance techniques, and develop new techniques focused on web application-specific issues. The work in quality assurance techniques focuses on improving three different areas: generating test inputs, verifying interface invocations, and detecting vulnerabilities. The evaluations of the resulting techniques show that the use of the program analyses results in significant improvements in existing quality assurance techniques and facilitates the development of new useful techniques.

Thesis (Ph. D.)--University of North Texas, May, 2009. / Title from title page display. Includes bibliographical references.

Since their breakthrough in the mid 1990's, web sites have become one of the most important channels for communication at Swedish universities. Drawing upon the analytical framework of "the production of culture perspective", the thesis investigates how the form and content of Swedish university web sites are influenced by the production milieu in which they are produced. Based on quantitative content analysis of the home pages of university web sites, the thesis documents changes in the form and content, such as links, headings, and body matter becoming more focused on marketing, as well as an increasing need for different kinds of navigation aids on the web sites. In addition to this, the thesis presents the results of fifteen in-depth interviews with informants working at various levels of the web organizations at Swedish universities. Using the production of culture perspective, together with previous research on media production in general, and literature on more specific areas, such as organization theory and communication, and media and technology, this presentation is followed by a discussion and analysis of structural, production related, factors, and their influence on the form and content of the web sites. The overall conclusion of the thesis is that the production of university web sites - their form and content - is about much more than available technology, web development processes, and different programming languages, to mention but a few examples. It is also about organizational routines, about the ways decisions are made, about policies for web publishing within the overall organization, about different stakeholders being put against each other, and it is about strategic choices about what to publish on the web and not. Furthermore, the thesis shows that structural factors function as constraints, as well as facilitators of web site production. For example, the width of web pages increases in correspondence with the increasing number of larger, high-resolution, displays used by the user; local policies and strategies decides the content to be focused; and a consistent form and layout of the university web sites are inhibited by the organizational structures and lines of command.

The problem of the study was to establish valid criteria for evaluating health-related World Wide Web [WWW] sites. From a table of specifications, a pool of 39 items was developed into a Criteria List. A nine member jury of experts composed of professionals from the discipline of Library and Information Science was used to determine content validity of the items. The items on the Criteria List were sent to the expert panel of jurors for the first review. To determine which items would be retained, revised or eliminated, the items were subjected to both a quantitative and qualitative review. The revised Criteria List was then sent to the expert panel of jurors for the second review. Responses from the second review were also subjected to qualitative and quantitative analysis. However, this time the quantitative review included the use of the Content-Validity Ratio [CVR]. All items on the Criteria List that were not statistically significant at p <.05 were eliminated. The final Criteria List contained 27 items from the 39 originally proposed items. / Department of Physiology and Health Science

This current study explored the reading strategies that emerged through the case studies of five sixth-grade students as they read Internet websites. Data was collected from student surveys, field notes, and transcripts of three separate Internet sessions that required participants to think aloud about the reading process as they explored web sites to answer questions. Despite the varying reading abilities of the subjects, upper elementary children use traditional as well as additional reading strategies when they read online articles. Using grounded theory, four reading strategy themes emerged consistently from three different reading sessions: determining importance (DI), matching skills (MS), monitoring understanding (MU), and navigating (N). Through this study, the researcher hoped to provide another snapshot of how the typical students in the upper elementary might read Internet resources which would ultimately allow classroom teachers to focus on the development of those strategies. / Department of Elementary Education

Thesis (Ph.D.)--Ohio University, August, 2007. / Title from PDF t.p. Includes bibliographical references.

Thesis (Ph.D.)--University of Western Sydney, 2008. / A thesis submitted to the University of Western Sydney, College of Health and Science, School of Computing and Mathematics, in fulfilment of the requirements for the degree of Doctor of Philosophy. Includes bibliographical references.