855 research outputs found

    Processing Posting Lists Using OpenCL

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    One of the main requirements of internet search engines is the ability to retrieve relevant results with faster response times. Yioop is an open source search engine designed and developed in PHP by Dr. Chris Pollett. The goal of this project is to explore the possibilities of enhancing the performance of Yioop by substituting resource-intensive existing PHP functions with C based native PHP extensions and the parallel data processing technology OpenCL. OpenCL leverages the Graphical Processing Unit (GPU) of a computer system for performance improvements. Some of the critical functions in search engines are resource-intensive in terms of processing power, memory, and I/O usage. The processing times vary based on the complexity and magnitude of data involved. This project involves different phases such as identifying critical resource intensive functions, initially replacing such methods with PHP Extensions, and eventually experimenting with OpenCL code. We also ran performance tests to measure the reduction in processing times. From our results, we concluded that PHP Extensions and OpenCL processing resulted in performance improvements

    Proceedings of the Workshop on web applications and secure hardware (WASH 2013).

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    Web browsers are becoming the platform of choice for applications that need to work across a wide range of different devices, including mobile phones, tablets, PCs, TVs and in-car systems. However, for web applications which require a higher level of assurance, such as online banking, mobile payment, and media distribution (DRM), there are significant security and privacy challenges. A potential solution to some of these problems can be found in the use of secure hardware – such as TPMs, ARM TrustZone, virtualisation and secure elements – but these are rarely accessible to web applications or used by web browsers. The First Workshop on Web Applications and Secure Hardware (WASH'13) focused on how secure hardware could be used to enhance web applications and web browsers to provide functionality such as credential storage, attestation and secure execution. This included challenges in compatibility (supporting the same security features despite different user hardware) as well as multi-device scenarios where a device with hardware mechanisms can help provide assurance for systems without. Also of interest were proposals to enhance existing security mechanisms and protocols, security models where the browser is not trusted by the web application, and enhancements to the browser itself

    Description and Experience of the Clinical Testbeds

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    This deliverable describes the up-to-date technical environment at three clinical testbed demonstrator sites of the 6WINIT Project, including the adapted clinical applications, project components and network transition technologies in use at these sites after 18 months of the Project. It also provides an interim description of early experiences with deployment and usage of these applications, components and technologies, and their clinical service impact

    Automated Debugging Methodology for FPGA-based Systems

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    Electronic devices make up a vital part of our lives. These are seen from mobiles, laptops, computers, home automation, etc. to name a few. The modern designs constitute billions of transistors. However, with this evolution, ensuring that the devices fulfill the designer’s expectation under variable conditions has also become a great challenge. This requires a lot of design time and effort. Whenever an error is encountered, the process is re-started. Hence, it is desired to minimize the number of spins required to achieve an error-free product, as each spin results in loss of time and effort. Software-based simulation systems present the main technique to ensure the verification of the design before fabrication. However, few design errors (bugs) are likely to escape the simulation process. Such bugs subsequently appear during the post-silicon phase. Finding such bugs is time-consuming due to inherent invisibility of the hardware. Instead of software simulation of the design in the pre-silicon phase, post-silicon techniques permit the designers to verify the functionality through the physical implementations of the design. The main benefit of the methodology is that the implemented design in the post-silicon phase runs many order-of-magnitude faster than its counterpart in pre-silicon. This allows the designers to validate their design more exhaustively. This thesis presents five main contributions to enable a fast and automated debugging solution for reconfigurable hardware. During the research work, we used an obstacle avoidance system for robotic vehicles as a use case to illustrate how to apply the proposed debugging solution in practical environments. The first contribution presents a debugging system capable of providing a lossless trace of debugging data which permits a cycle-accurate replay. This methodology ensures capturing permanent as well as intermittent errors in the implemented design. The contribution also describes a solution to enhance hardware observability. It is proposed to utilize processor-configurable concentration networks, employ debug data compression to transmit the data more efficiently, and partially reconfiguring the debugging system at run-time to save the time required for design re-compilation as well as preserve the timing closure. The second contribution presents a solution for communication-centric designs. Furthermore, solutions for designs with multi-clock domains are also discussed. The third contribution presents a priority-based signal selection methodology to identify the signals which can be more helpful during the debugging process. A connectivity generation tool is also presented which can map the identified signals to the debugging system. The fourth contribution presents an automated error detection solution which can help in capturing the permanent as well as intermittent errors without continuous monitoring of debugging data. The proposed solution works for designs even in the absence of golden reference. The fifth contribution proposes to use artificial intelligence for post-silicon debugging. We presented a novel idea of using a recurrent neural network for debugging when a golden reference is present for training the network. Furthermore, the idea was also extended to designs where golden reference is not present

    Digital evidence bags

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    This thesis analyses the traditional approach and methodology used to conduct digital forensic information capture, analysis and investigation. The predominant toolsets and utilities that are used and the features that they provide are reviewed. This is used to highlight the difficulties that are encountered due to both technological advances and the methodologies employed. It is suggested that these difficulties are compounded by the archaic methods and proprietary formats that are used. An alternative framework for the capture and storage of information used in digital forensics is defined named the `Digital Evidence Bag' (DEB). A DEB is a universal extensible container for the storage of digital information acquired from any digital source. The format of which can be manipulated to meet the requirements of the particular information that is to be stored. The format definition is extensible thereby allowing it to encompass new sources of data, cryptographic and compression algorithms and protocols as developed, whilst also providing the flexibility for some degree of backwards compatibility as the format develops. The DEB framework utilises terminology to define its various components that are analogous with evidence bags, tags and seals used for traditional physical evidence storage and continuity. This is crucial for ensuring that the functionality provided by each component is comprehensible by the general public, judiciary and law enforcement personnel without detracting or obscuring the evidential information contained within. Furthermore, information can be acquired from a dynamic or more traditional static environment and from a disparate range of digital devices. The flexibility of the DEB framework permits selective and/or intelligent acquisition methods to be employed together with enhanced provenance and continuity audit trails to be recorded. Evidential integrity is assured using accepted cryptographic techniques and algorithms. The DEB framework is implemented in a number of tool demonstrators and applied to a number of typical scenarios that illustrate the flexibility of the DEB framework and format. The DEB framework has also formed the basis of a patent application

    Cybersecurity: Past, Present and Future

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    The digital transformation has created a new digital space known as cyberspace. This new cyberspace has improved the workings of businesses, organizations, governments, society as a whole, and day to day life of an individual. With these improvements come new challenges, and one of the main challenges is security. The security of the new cyberspace is called cybersecurity. Cyberspace has created new technologies and environments such as cloud computing, smart devices, IoTs, and several others. To keep pace with these advancements in cyber technologies there is a need to expand research and develop new cybersecurity methods and tools to secure these domains and environments. This book is an effort to introduce the reader to the field of cybersecurity, highlight current issues and challenges, and provide future directions to mitigate or resolve them. The main specializations of cybersecurity covered in this book are software security, hardware security, the evolution of malware, biometrics, cyber intelligence, and cyber forensics. We must learn from the past, evolve our present and improve the future. Based on this objective, the book covers the past, present, and future of these main specializations of cybersecurity. The book also examines the upcoming areas of research in cyber intelligence, such as hybrid augmented and explainable artificial intelligence (AI). Human and AI collaboration can significantly increase the performance of a cybersecurity system. Interpreting and explaining machine learning models, i.e., explainable AI is an emerging field of study and has a lot of potentials to improve the role of AI in cybersecurity.Comment: Author's copy of the book published under ISBN: 978-620-4-74421-

    Collaborative geographic visualization

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    Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para a obtenção do grau de Mestre em Engenharia do Ambiente, perfil Gestão e Sistemas AmbientaisThe present document is a revision of essential references to take into account when developing ubiquitous Geographical Information Systems (GIS) with collaborative visualization purposes. Its chapters focus, respectively, on general principles of GIS, its multimedia components and ubiquitous practices; geo-referenced information visualization and its graphical components of virtual and augmented reality; collaborative environments, its technological requirements, architectural specificities, and models for collective information management; and some final considerations about the future and challenges of collaborative visualization of GIS in ubiquitous environment

    Introductory Computer Forensics

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    INTERPOL (International Police) built cybercrime programs to keep up with emerging cyber threats, and aims to coordinate and assist international operations for ?ghting crimes involving computers. Although signi?cant international efforts are being made in dealing with cybercrime and cyber-terrorism, ?nding effective, cooperative, and collaborative ways to deal with complicated cases that span multiple jurisdictions has proven dif?cult in practic
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