Thesis (M.Ed.)--University of the Witwatersrand, Faculty of Education, 1994.

WhatsApp is the most popular instant messaging application worldwide. Since 2016, users can send and receive messages through desktop clients, either through the WhatsApp desktop application or the web client accessible from supported web browsers. The author identified a gap in the literature in terms of WhatsApp forensics for desktop and web clients. The aim of the study was to locate forensic artifacts on WhatsApp clients. These clients included the desktop application on both Windows and Mac operating systems. Chrome and Firefox web clients were also analyzed for the Windows operating system, as well as Chrome and Safari web clients on the Mac operating system. A WhatsApp log file was identified as the main artifact providing information throughout all clients analyzed. Cached profile pictures were also found, as well as history information about visited websites and ran applications.

The Internet of Things is deploying large numbers of bare-metal systems that have no protection against memory corruption and control-flow hijacking attacks. These attacks have enabled unauthorized entry to hotel rooms, malicious control of unmanned aerial vehicles, and invasions of privacy. Using static and dynamic analysis these systems can utilize state-of-the-art testing techniques to identify and<br>prevent memory-corruption errors and employ defenses against memory corruption and control-flow hijacking attacks in bare-metal systems that match or exceed those currently employed on desktop systems. This is shown using three case studies.<br><br>(1) EPOXY which, automatically applies data execution prevention, diversity, stack defenses, and separating privileged code from unprivileged code using a novel<br>technique called privileged overlaying. These protections prevent code injection attacks, and reduce the number of privileged instruction to 0.06% verses an unprotected<br>application.<br><br>(2) Automatic Compartments for Embedded Systems (ACES), which automatically creates compartments that enforce data integrity and code isolation within bare-metal applications. ACES enables exploring policies to best meet security and performance requirements for individual applications. Results show ACES' can form 10s of compartments within a single thread and has a 15% runtime overhead on average.<br><br><div>(3) HALucinator breaks the requirement for specialized hardware to perform bare-metal system testing. This enables state-of-the-art testing techniques –e.g., coverage based fuzzing – to scale with the availability of commodity computers, leading to the discovery of exploitable vulnerabilities in bare-metal systems. <br></div><div><br></div><div>Combined, these case studies advance the security of embedded system several decades and provide essential protections for today’s connected devices.</div>

Since the use of social media has evolved, the ability of its users to bully others has increased. One of the prevalent forms of bullying is Cyberbullying, which occurs on the social media sites such as Facebook©, WhatsApp©, and Twitter©. The past decade has witnessed a growth in cyberbullying – is a form of bullying that occurs virtually by the use of electronic devices, such as messaging, e-mail, online gaming, social media, or through images or mails sent to a mobile. This bullying is not only limited to English language and occurs in other languages. Hence, it is of the utmost importance to detect cyberbullying in multiple languages. Since current approaches to identify cyberbullying are mostly focused on English language texts, this thesis proposes a new approach (called Multilingual Cyberbullying Detection System) for the detection of cyberbullying in multiple languages (English, Hindi, and Marathi). It uses two techniques, namely, Machine Learning-based and Lexicon-based, to classify the input data as bullying or non-bullying. The aim of this research is to not only detect cyberbullying but also provide a distributed infrastructure to detect bullying. We have developed multiple prototypes (standalone, collaborative, and cloud-based) and carried out experiments with them to detect cyberbullying on different datasets from multiple languages. The outcomes of our experiments show that the machine-learning model outperforms the lexicon-based model in all the languages. In addition, the results of our experiments show that collaboration techniques can help to improve the accuracy of a poor-performing node in the system. Finally, we show that the cloud-based configurations performed better than the local configurations.

Made available in DSpace on 2017-07-21T14:19:34Z (GMT). No. of bitstreams: 1 Anderson Estevam Rosa.pdf: 3262543 bytes, checksum: c3518741cd61f3841cdebd7d20f65884 (MD5) Previous issue date: 2012-07-23 / Precision agriculture is still considered a new topic in Brazil, even by the Brazilian Agricultural Research Corporation (Embrapa), which, in 2012, published a book on the subject and had more than 4.5 million hits in less than a month of its publication. It demonstrates that this is a promising area of interest and can be the difference for Brazil's agriculture be increasingly competitive still in a sustainable way. Thus, the replacement of the manual for an automated process and georeferenced data collection in the field becomes more rapid, standardized, and accurate. One can also observe that the use of mobile devices is perhaps one of the keys to the future, since they are of considerable computational capacity on low cost, and obviously portable. Therefore, this study aims to develop a software for embedded computers or phones, with georeferenced points and routes and route correction using Fuzzy Logic. The correction of the route is necessary due to possible deviations caused by common elements in the field, such as rocks, holes and vegetation. This system will be used by the robot field being developed in the Laboratory of Automation and Robotics at the State University of Ponta Grossa, PR, the AGROBOT. The validation of the computer system was done manually, ie, yet without the robot, the author of this work, performed on foot paths with embedded computer in hand. During the course, the data were collected to study the results, making a comparison between the correction obtained by Fuzzy Logic and mathematics correction given by subtracting the initial and current angle of the device to the target point. As a result it was graphically demonstrated that the use of fuzzy logic has proved more effective in comparison with the simple subtraction mathematics, mainly in response to the error location GPS devices / A agricultura de precisão ainda é um tema considerado novo no Brasil, até mesmo pela Empresa Brasileira de Pesquisa Agropecuária (Embrapa), que em 2012 lançou um livro sobre tema e teve mais de 4500 acessos em menos de um mês de publicação. Isso demonstra que esta é uma área promissora, de interesse geral e pode ser o diferencial para que cada vez mais a agricultura no Brasil seja competitiva sem deixar de ser sustentável. Sendo assim, a substituição do processo manual por um processo automatizado e georreferenciado faz com que a coleta de dados no campo se torne mais rápida, padronizada e precisa. Pode-se observar também que o uso de dispositivos móveis talvez seja uma das chaves para o futuro, uma vez que são aparelhos de considerável capacidade computacional, relativo baixo custo e, obviamente, portáteis. Desta forma, o presente trabalho tem por objetivo desenvolver um sistema computacional para computadores embarcados ou celulares, de marcação de pontos e rotas georreferenciadas e correção da rota utilizando Lógica Fuzzy. A correção da rota se faz necessária devido aos possíveis desvios, causados por elementos comuns no campo, como pedras, buracos e vegetação. Este sistema será utilizado pelo robô de campo que está sendo desenvolvido no Laboratório de Automação e Robótica da Universidade Estadual de Ponta Grossa-PR, o projeto AGROBOT. A validação do sistema computacional foi feita manualmente, ou seja, ainda sem o robô, pelo autor do trabalho, em trajetos realizados a pé com o computador embarcado em mãos. Durante o percurso do trajeto foram feitas coletas de dados para estudo dos resultados, fazendo um comparativo entre a correção obtida pela Lógica Fuzzy e a correção matemática dada pela subtração do ângulo inicial e atual do dispositivo com o ponto alvo. Como resultado foi demonstrado graficamente que o uso da lógica Fuzzy mostrou-se mais eficaz em comparação com a simples subtração matemática, principalmente em resposta ao erro de localização dos dispositivos GPS.

Submitted by Filipe dos Santos (fsantos@pucsp.br) on 2017-06-08T12:57:58Z No. of bitstreams: 1 Albert Florencio da Costa.pdf: 7724360 bytes, checksum: c3561856ecba1bc5c6aac8e554df15b8 (MD5) / Made available in DSpace on 2017-06-08T12:57:58Z (GMT). No. of bitstreams: 1 Albert Florencio da Costa.pdf: 7724360 bytes, checksum: c3561856ecba1bc5c6aac8e554df15b8 (MD5) Previous issue date: 2017-05-02 / This study presents an analysis of friendly interfaces for Internet systems, which facilitates the use of commercial consultants (non-technical) in creating digital business. The objective of this study is to verify the importance of friendly digital platforms so that lay commercial consultants are not eliminated from the market, in the current environment where digital businesses are growing every day. Through a bibliographic review, presenting the current scenario in which the commercial consultants beds are inserted, as well as the technical requirements necessary to build a good interface, we analyze the use of the Interface (OnCorretor) offered by the company Porto Seguro to its Insurance Brokers Who are the commercial consultants of this market. We conclude that the OnCorretor is a platform that meets the brokers business expectations, accessible including being by lay users, allowing them to build their own websites with your domain, manage email accounts, manage online proposals, interact with their customers. The OnCorretor platform has a user-friendly interface that makes it easy to use, but some users still have questions about how to get the best results in their business. In this way, we suggest that an online training, as well as a greater use of interaction with social networks, be made available to the user whenever he needs it. We also suggest periodic surveys for the maintenance and optimization of your business, with presence on the Internet and on social networks. The most important finding is that the user-friendly interface is simple to use for 75.6% of respondent brokers and 63.2% of them understand that it has helped to optimize their business. We suggest that other companies in the insurance industry or other using consultants commercial to develop similar platforms based on this model / Este estudo apresenta uma análise das interfaces amigáveis para sistemas de Internet, que facilitem o uso para Consultores comerciais leigos (não-técnicos) na realização de negócios digitais. O Objetivo desse estudo é verificar a importância de plataformas digitais amigáveis para que consultores comerciais leigos não sejam eliminados do mercado, na atual conjuntura onde os negócios digitais vêm crescendo a cada dia. Através de uma revisão bibliográfica, apresentando o cenário atual em que os Consultores Comerciais leigos estão inseridos, bem como os requisitos técnicos necessários para construção de uma boa interface, analisamos o uso da Interface (OnCorretor) oferecida pela empresa Porto Seguro a seus Corretores de Seguro que são os Consultores comerciais desse mercado. Concluímos que o OnCorretor é uma plataforma que atende às expectativas de negócios dos corretores, sendo acessível inclusive por usuários leigos, permitindo que eles possam construir seus próprios sites, com seu domínio, gerenciar contas de email, gerenciar propostas online, interagir com seus clientes. A plataforma OnCorretor possui uma interface amigável que facilita a sua utilização, mas, alguns usuários ainda têm dúvidas sobre como obter os melhores resultados em seus negócios. Deste modo, sugerimos que seja disponibilizado um treinamento online, bem como uma utilização maior de interação com redes sociais, que seja acessível ao usuário sempre que ele precisar. Sugerimos também pesquisas periódicas para a manutenção e otimização de seu negócio, com presença na Internet e nas redes sociais. A mais importante constatação é que a interface amigável é simples de ser usada para 75,6% dos corretores respondentes e que 63.2% deles entendem que ela ajudou a otimizar seus negócios. Sugerimos que outras empresas do setor de seguros ou outras que utilizem Consultores Comerciais que desenvolvam plataformas similares baseadas nesse modelo

Thesis (B.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1982. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING / Includes bibliographical references. / by Cheryl Ann Wheeler. / B.S.

Many e-voting techniques have been proposed but not widely used in reality. One of the problems associated with most of existing e-voting techniques is the lack of transparency, leading to a failure to deliver voter assurance. In this work, we propose a transparent, auditable, end-to-end verifiable, and mutual restraining e-voting protocol that exploits the existing multi-party political dynamics such as in the US. The new e-voting protocol consists of three original technical contributions -- universal verifiable voting vector, forward and backward mutual lock voting, and in-process check and enforcement -- that, along with a public real time bulletin board, resolves the apparent conflicts in voting such as anonymity vs. accountability and privacy vs. verifiability. Especially, the trust is split equally among tallying authorities who have conflicting interests and will technically restrain each other. The voting and tallying processes are transparent to voters and any third party, which allow any voter to verify that his vote is indeed counted and also allow any third party to audit the tally. For the environment requiring receipt-freeness and coercion-resistance, we introduce additional approaches to counter vote-selling and voter-coercion issues. Our interactive voting protocol is suitable for small number of voters like boardroom voting where interaction between voters is encouraged and self-tallying is necessary; while our non-interactive protocol is for the scenario of large number of voters where interaction is prohibitively expensive. Equipped with a hierarchical voting structure, our protocols can enable open and fair elections at any scale.

This thesis examines how the right of free movement of persons is governed through surveillance databases represented as security measures by applying the governmentality perspective. In order to do that, the study focuses on the relationship between freedom of movement, security and surveillance databases in the European Union such as Schengen Information System (SIS), European Dactylographic System (EURODAC) and the Europol Computer System (TECS). The main argument of the thesis is to analyze the role of surveillance databases in controlling the free movements of certain kinds of people that are seen as a &quot / threat&quot / to the European internal security.

In safety-critical, networked embedded systems, it is important that the way in which a fault(s) in one component of the system can propagate throughout the system to other components is analyzed correctly. Many real-world systems, such as modern aircrafts and automobiles, use large-scale networked embedded systems with complex behavior. In this work, we have developed techniques and a software tool, FauPA, that uses those techniques to automate fault-propagation analysis of large-scale, networked embedded systems such as those used in modern aircraft. This work makes three main contributions. 1. Fault propagation analyses. We developed algorithms for two types of analyses: forward analysis and backward analysis. For backward analysis, we developed two techniques: a naive algorithm and an algorithm that uses Datalog. 2. A system description language. We developed a language that we call Communication System Markup Language (CSML) based on XML. A system can be specified concisely and at a high-level in CSML. 3. A GUI-based display of the system and analysis results. We developed a GUI to visualize the system that is specified in CSML. The GUI also lets the user visualize the results of fault-propagation analyses.