SYSTEMATIC POLICY ANALYSIS AND MANAGEMENT

Determining whether a given policy meets a site’s high-level security goals has been a challenging task, due to the low-level nature and complexity of the policy language, various security requirements and the multiple policy violation patterns. In this dissertation, we outline a systematic policy analysis and management approach that enables system administrators to easily identify and resolve various policy violations. Our approach incorporates a domain-based isolation model to address the security requirements and visualization mechanisms to provide the policy administrator with intuitive cognitive sense about the policy analysis and policy violations. Based on the domain-based isolation model and the policy visualization mechanisms, we develop a visualization-based policy analysis and management framework. We also describe our implementation of a visualization-based policy analysis and management tool that provides the functionalities discussed in our framework. In addition, a user study is performed and the result is included as part of our evaluation efforts for the prototype system. One important application of our policy analysis and management is to support remote attestation. Remote attestation is an important mechanism to provide the trustworthiness proof of a computing system by verifying its integrity. In our work, we propose a remote attestation framework, called Dynamic Remote Attestation Framework and Tactics (DR@FT), for efficiently attesting a target system based on our extended visualization-based policy analysis and management approach. In addition, we adopt the proposed visualization-based policy violation expression to represent integrity violations with a ranked violation graph, which supports intuitive reasoning of attestation results. We also describe our experiments and performance evaluation

Um modelo para recuperação e busca de informação baseado em ontologia e no círculo hermenêutico

Tese (doutorado) - Universidade Federal de Santa Catarina, Centro Tecnoclógico. Programa de Pós-graduação em Engenharia e Gestão do ConhecimentoOs sistemas de busca, mesmo com avanços quanto à organização da informação e taxas de precisão e recuperação, ainda são baseados apenas na comparação de termos de busca, que ignora o possível aprendizado que existe nas iterações subseqüentes à primeira busca. Com base nesta constatação, propõe-se um modelo de recuperação e busca de informação com base nas teorias referentes ao círculo hermenêutico, information seeking, recuperação de informação e ontologias. Uma ontologia de domínio é usada para a construção de indexadores da base de conhecimento e para viabilizar a metáfora do círculo hermenêutico, ou seja, permitir que usuários naveguem nos conceitos da ontologia e nas instâncias desses conceitos em uma forma de vai e vem. A demonstração de viabilidade do modelo é realizada por meio do framework Hermeneus, que dá suporte à construção de sistemas de busca que alternam diferentes tipos de estratégias para o refinamento das buscas, e pela comparação com outros modelos de recuperação e busca de informação. Hermeneus atua como um intermediário entre o usuário e a informação requerida, conectando as questões que o usuário tem em mente às respostas que são encontradas nas iterações de busca com contextualização em ontologia. Dessa forma, o modelo proporciona que a dinamicidade requerida por sistemas de busca seja alcançada, pois em um processo de busca o significado está sempre sendo criado e recriado

A visual information seeking system for Web search

In this paper we present the conception and the evaluation of a visual information seeking system for the Web. Our work has been motivated by the lack of good user interfaces assisting the user in searching the Web. The selected visualisations and why they have been chosen are explained in detail. A focus of this paper is on the evaluation of these visualisations as an add-on to the traditional result list presentation

A Visual Information Seeking System for Web Search

In this paper we present the conception and the evaluation of a visual information seeking system for the Web. Our work has been motivated by the lack of good user interfaces assisting the user in searching the Web. The selected visualisations and why they have been chosen are explained in detail. A focus of this paper is on the evaluation of these visualisations as an add-on to the traditional result list presentation

M.: A visual information seeking system for Web search

In this paper we present the conception and the evaluation of a visual information seeking system for the Web. Our work has been motivated by the lack of good user interfaces assisting the user in searching the Web. The selected visualisations and why they have been chosen are explained in detail. A focus of this paper is on the evaluation of these visualisations as an add-on to the traditional result list presentation.