Orientador: Paulo Lício de Geus / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Computação / Made available in DSpace on 2018-08-16T05:27:31Z (GMT). No. of bitstreams: 1 Cavalcante_GabrielDieterich_M.pdf: 3073328 bytes, checksum: aeb145421a7f9c0c3d3ac872eb9ac054 (MD5) Previous issue date: 2010 / Resumo: Existe uma grande quantidade de configurações presentes em sistemas atuais e gerir essas configurações é um trabalho árduo para qualquer administrador de sistema. Inúmeras configurações podem ser definidas para uma só máquina e as combinações entre elas implicam de forma significativa no seu desempenho. A partir do momento que um sistema em pleno funcionamento pára de funcionar, algo em sua estrutura pode ter mudado. Este cenário é comum no processo de desenvolvimento de software onde o código fonte pode deixar de compilar ou ainda uma funcionalidade pode se perder. Controladores de versão são usados para reverter o estado do código para uma data anterior, solucionando o problema. Verificadores de Integridade são utilizados para detectar estas mudanças, porém não possuem mecanismos específicos para recuperação. Este estudo propõe e implementa uma arquitetura integrada que combina verificação de integridade e mecanismos de recuperação. Foram executados testes para determinar a sobrecarga total deste método, além de estudos de caso para verificar a sua eficiência de recuperação / Abstract: Current computer systems have a huge number of configurations that are hard to manage. The combinations of system configurations can impact on performance and behavior. From the moment that a system stops working correctly it is remarkable that something has changed. That is in common in software development, where changes made by the programmer may result in some features no longer working or the project not compiling anymore. Revision control systems can recover a previous state of the source code through revision mechanisms. Integrity checking is used to catch file modifications, however this technique does nothing toward recovering those files. This study proposes and implements an integrated architecture that combines integrity checking and restoring mechanisms. Tests were executed in order to measure the load imposed by the solution. In addition, analysis of three case studies shows the efficiency of the adopted solution / Mestrado / Segurança de Computadores

Submitted by Andre Untem (andre.untem@gmail.com) on 2012-12-19T16:03:46Z No. of bitstreams: 1 AndreOkamotoUntem_VersaoFinal.pdf: 2195184 bytes, checksum: 69027860a1e2b638618a529983245436 (MD5) / Approved for entry into archive by Marcia Bacha (marcia.bacha@fgv.br) on 2012-12-20T16:09:39Z (GMT) No. of bitstreams: 1 AndreOkamotoUntem_VersaoFinal.pdf: 2195184 bytes, checksum: 69027860a1e2b638618a529983245436 (MD5) / Made available in DSpace on 2012-12-20T16:10:00Z (GMT). No. of bitstreams: 1 AndreOkamotoUntem_VersaoFinal.pdf: 2195184 bytes, checksum: 69027860a1e2b638618a529983245436 (MD5) Previous issue date: 2012-06-25 / In this work, we will present a series of general and partial equilibrium models that deals with human capital accummulation, social security systems, labor supply and retirement. We willanalyse the relations between different mechanisms of human capital accummulation and productivity; relations between uncertaints and hypothesis about credit markets; and the influence of those variables on households' decision of retirment. / Neste trabalho, serão apresentados artigos que abordam modelos de equilíbrio geral e parcial que tratem da acumulação de capital humano, sistemas de previdência, oferta de trabalho e aposentadoria. São feitas análises entre diferentes mecanismos de acumulação humano e sua relação com produtividade; relações entre incertezas e hipóteses sobre mercados de crédito; e.a in uência dessas variáveis na aposentadoria das pessoas.

This thesis deals with automation of buildings, provides the possibility of automation in today's intelligent buildings. The issue of building automation for security and access systems is solved in details. This thesis contains the basic rules of the systems and procedure in the implementation of access and security systems. The target of this thesis is the proposal of the access and security system for buildings. Part of the thesis is also creating a model, on which will be presented the access and security system. This model will be used by the company ELMONT GROUP as a basis for dealing with contracts.

Cette thèse étudie le choix optimal du système de retraite en Palestine. L'économie palestinienne se caractérise par un très faible niveau de protection sociale et un taux de pauvreté élevé .Le premier chapitre présente une analyse de l'environnement démographique, social et économique en Palestine. Le deuxième chapitre propose une revue de littérature sur les systèmes de protection sociale. Le troisième chapitre analyse le taux d'accès au système de protection sociale en fonction de différentes s caractéristiques socio-économiques. Le quatrième chapitre présente une analyse économétrique de la décision de participer au système de retraite. Le cinquième chapitre, en mobilisant le modèle PROST (Banque Mondiale), propose une analyse prospective du système de retraite en Palestine. L'étude prospective détermine le taux de cotisation approprié en fonction de plusieurs scénarios de chômage et son impact sur l'équilibre du système de retraite en prenant en compte la situation spécifique des femmes en Palestine. / This thesis aims to explore the optimal choice of retirement system for the Palestinian case motivated primarily by the problems of high poverty rate and the noticeably low coverage rate of social security.Accordingly, the first chapter focused on the environmental analysis of the Palestinian case. The second chapter focused on the literature review of social security. The third chapter explores the access rate to social security systems in each aspect of social security by socioeconomic characteristics. While, fourth chapter present an econometric analysis about the decision to participate at the pension system. Finally, chapter five presents and discusses guidelines for an optimal alternative pension reform followed by a projection test for proposed parameters of DB scheme using PROST model (World Bank) in several scenarios. The results determined the most important characteristics that increase the probability to participate to a pension system. Further, the projection shows the proper contribution rates in each unemployment scenario and its impact on the balance of the system and adequacy of income given the specific situation of females in Palestine.

The researcher attempts to establish how CCTV footage can be used as a surveillance technique, for evidence gained in that way to be admissible in court. To conduct effective investigation, it is important for investigators to be familiar with the application of CCTV footage, its purpose, its benefits and shortfalls. To achieve the goals and objectives of the practice of CCTV footage, investigators must know how to utilise the value of its evidence, and how to use it to identify suspects. The clarification and application to the crime situation, the identification of the perpetrator or suspect of a criminal act is mostly impossible, if CCTV footage is not available to assist in identification and tracing of suspects. / Police Practice / M. Tech. (Forensic Investigation)

A system is only as secure as the weakest link in the chain. Humans are the binding link between IT (information technology) security and physical secu-rity. In general, the human is often considered as the weakest link in the chain, so social engineering attacks are used to manipulate or trick people to accom-plish the goal of bypassing security systems. Within this master thesis, we answer several research questions related to social engineering. Most im-portant is to find out why humans are considered as the weakest link and why existing guidelines are failing, as well as to achieve the goal of raising aware-ness and starting education at a young age. For this, we examine existing lit-erature on the subject and create experiments, an interview, a campaign eval-uation, and a survey. Our systematic work begins with an introduction, the methodology, a definition of social engineering and explanations of state-of-the-art social engineering methods. The theoretical part of this thesis also in-cludes ethical and psychological aspects and an evaluation of existing guide-lines with a review of why they are not successful.Furthermore, we continue with the practical part. An interview with a profes-sional security consultant focusing on social engineering from our collabora-tion company TÜV TRUST IT GmbH (TÜV AUSTRIA Group)1 is con-ducted. A significant part here deals with awareness-raising overall, espe-cially at a younger age. Additionally, the countermeasures against each dif-ferent social engineering method are analysed. Another practical part is the evaluation of existing social engineering campaigns2 from TÜV TRUST IT GmbH TÜV AUSTRIA Group to see how dangerous and effective social en-gineering has been in the past. From experience gained in this thesis, guide-lines on dealing with social engineering are discussed before the thesis is fi-nalized with results, the conclusion and possible future work.

[pt] Uma estratégia comum de linha de produtos de software envolve sistemas da Web baseados em plug-ins que suportam a incorporação simples e rápida de comportamentos personalizados, sendo amplamente adotados para criar aplicativos baseados na web. A popularidade dos ecossistemas que suportam o desenvolvimento baseado em plug-ins (como o WordPress) é, em grande parte, devido ao número de opções de personalização disponíveis como plug-ins contribuídos pela comunidade. Entretanto, as vulnerabilidades relacionadas a plug-ins tendem a ser recorrentes, exploráveis e difíceis de serem detectadas e podem levar a graves conseqüências para o produto personalizado. Portanto, é necessário entender essas vulnerabilidades para permitir a prevenção de ameaças de segurança relevantes. Neste trabalho, realizamos um estudo exploratório para caracterizar vulnerabilidades causadas por plug-ins em sistemas baseados na web, examinando os boletins de vulnerabilidade do WordPress catalogados pelo National Vulnerability Database e os patches associados, mantidos pelo repositório de plugins do WordPress. Identificamos os principais tipos de vulnerabilidades, o seu impacto e o tamanho do patch para corrigir a vulnerabilidade. Identificamos, também, os tópicos mais comuns relacionados à segurança discutidos entre os desenvolvedores do WordPress. Observamos que, embora as vulnerabilidades possam ter consequências graves e permanecerem despercebidas por muito tempo, elas geralmente podem ser atenuadas com pequenas alterações no código-fonte. A caracterização ajuda a fornecer uma compreensão de como tais vulnerabilidades se manifestam na prática e contribui com as novas gerações de ferramentas de teste de vulnerabilidades capazes de antecipar sua possível ocorrência. Esta pesquisa propõe uma ferramenta de suporte para mitigar a ocorrência de vulnerabilidades em sistemas baseados em plugins web, facilitando a descoberta e antecipação da possível ocorrência de vulnerabilidades. / [en] A common software product line strategy involves plug-in-based web systems that support the simple and rapid incorporation of custom behaviors and are widely adopted for building web-based applications. The popularity of ecosystems that support plug-in-based development (such as WordPress) is largely due to the number of customization options available as community-contributed plugins. However, plug-in related vulnerabilities tend to be recurring, exploitable and difficult to detect and can lead to serious consequences for the custom product. Therefore, these vulnerabilities must be understood to enable the prevention of relevant security threats. In this paper, we conduct an exploratory study to characterize plug-in vulnerabilities in web-based systems by examining the WordPress vulnerability bulletins cataloged by the National Vulnerability Database and the associated patches maintained by the WordPress plugin repository. We identify the main types of vulnerabilities, their impact, and the size of the patch to address the vulnerability. We have also identified the most common securityrelated topics discussed among WordPress developers. We note that while vulnerabilities can have serious consequences and remain unnoticed for a long time, they can often be mitigated with minor changes to source code. Characterization helps provide an understanding of how such vulnerabilities manifest themselves in practice and contributes to new generations of vulnerability testing tools that can anticipate their potential occurrence. This research proposes a support tool to mitigate the occurrence of vulnerabilities in web plugin based systems, facilitating the discovery and anticipation of the possible occurrence of vulnerabilities.

Traditional solutions to information security in communication systems act in the application layer and are oblivious to the effects in the physical layer. Physical-layer security methods, of which information-theoretic security is a special case, try to extract security from the random effects in the physical layer. In information-theoretic security, there are two asymptotic notions of secrecy---weak and strong secrecy This dissertation investigates the problem of information-theoretic strong secrecy on the binary erasure wiretap channel (BEWC) with a specific focus on designing practical codes. The codes designed in this work are based on analysis and techniques from error-correcting codes. In particular, the dual codes of certain low-density parity-check (LDPC) codes are shown to achieve strong secrecy in a coset coding scheme. First, we analyze the asymptotic block-error rate of short-cycle-free LDPC codes when they are transmitted over a binary erasure channel (BEC) and decoded using the belief propagation (BP) decoder. Under certain conditions, we show that the asymptotic block-error rate falls according to an inverse square law in block length, which is shown to be a sufficient condition for the dual codes to achieve strong secrecy. Next, we construct large-girth LDPC codes using algorithms from graph theory and show that the asymptotic bit-error rate of these codes follow a sub-exponential decay as the block length increases, which is a sufficient condition for strong secrecy. The secrecy rates achieved by the duals of large-girth LDPC codes are shown to be an improvement over that of the duals of short-cycle-free LDPC codes.

Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-04-18T15:01:39Z No. of bitstreams: 1 MARCELL MANFRIN BARBACENA - DISSERTAÇÃO PPGCC 2014..pdf: 1468565 bytes, checksum: b94d20ffdace21ece654986ffd8fbb63 (MD5) / Made available in DSpace on 2018-04-18T15:01:39Z (GMT). No. of bitstreams: 1 MARCELL MANFRIN BARBACENA - DISSERTAÇÃO PPGCC 2014..pdf: 1468565 bytes, checksum: b94d20ffdace21ece654986ffd8fbb63 (MD5) Previous issue date: 2014 / Impulsionadas pela crescente demanda por sistemas de segurança para proteção do indivíduo e da propriedade nos dias atuais, várias pesquisas têm sido desenvolvidas com foco na implantação de sistemas de vigilância por vídeo com ampla cobertura. Um dos problemas de pesquisa em aberto nas áreas de visão computacional e redes de computadores envolvem a escalabilidade desses sistemas, principalmente devido ao aumento do número de câmeras transmitindo vídeos em tempo real para monitoramento e processamento. Neste contexto, o objetivo geral deste trabalho é avaliar o impacto que a redução da taxa de transmissão dos fluxos de vídeos impõe na eficácia dos algoritmos de detecção de pessoas utilizados em sistemas inteligentes de videovigilância. Foram realizados experimentos utilizando vídeos em alta resolução no contexto de vigilância com tomadas externas e com um algoritmo de detecção de pessoas baseado em histogramas de gradientes orientados, nos quais se coletou, como medida de eficácia do algoritmo, a métrica de área sob a curva de precisão e revocação para, em sequência, serem aplicados os testes estatísticos de Friedman e de comparações múltiplas com um controle na aferição das hipóteses levantadas. Os resultados obtidos indicaram que é possível uma redução da taxa de transmissão em mais de 70% sem que haja redução da eficácia do algoritmo de detecção de pessoas. / Motivated by the growing demand for security systems to protect persons and properties in the nowadays, several researches have been developed focusing on the deployment of widearea video coverage surveillance systems. One open research problem in the areas of computer vision and computer networks involves the scalability of these systems, mainly due to the increasing number of cameras transmitting real-time video for monitoring and processing. In this context, the aim of this study was to evaluate the impact that transmission data-rate reduction of video streams imposes on the effectiveness of people detection algorithms used in intelligent video surveillance systems. With a proposed experimental design, experiments were performed using high-resolution wide-area external coverage video surveillance and using an algorithm for people detection based on histograms of oriented gradients. As a measure of effectiveness of the people detection algorithm, the metric of area under the precision-recall curve was collected and statistical tests of Friedman and multiple comparisons with a control were applied to evaluate the hypotheses. The results indicated that it is possible to reduce transmission rate by more than 70% without decrease in the effectiveness of the people detection algorithm.

The scope of this work is analysing how economic policies chosen by governments are influenced by the power of social groups. The core idea is taken from the single-mindedness theory, which states that preferences of groups and their ability to focus on the consumption of goods enable them to obtain the most favourable policies. This approach exploits the advantages of probabilistic voting theory, ability to manage the multidiemnsionality and possibility to study precisely how politicians tailor their policies to groups' features. Unlike classic probabilistic voting models, my theory assumes that the density function which captures the distribution of political preferences depends on consumption of goods and preferences of individuals. The higher the consumption of goods, the higher the density, the higher the political power. This mechanism is better explained by considering the role played by "swing voters". Since they are pivotal to changing the equilibrium, candidates must favour them because they realise that even a small change in policy could force them to vote for the other candidate, Thus, the lower the loyalty of voters for parties, the higher the benefit they obtain. As a consequence, these voters are better off and represent the winners of the political process.