A MapReduce Algorithm for Finding Hotspots of Topics from Time Stamped Documents

Hotspots of a word/topic are time periods with a burst of activities in a time stamped document set. Identifying and analyzing hot spots of topics has been an important area of research. Finding hot spots of topics requires processing of contents of documents which is often time consuming. In this thesis, we explore MapReduce style algorithms for computing hot spots of topics. MapReduce is a distributed parallel programming model and an associated implementation for processing and analyzing large datasets. User specifies a map function that processes a key/value pair to generate a set of intermediate key/value pairs, and a reduce function that merges all intermediate values associated with the same intermediate key. Many real world tasks are expressible in this model and this thesis explores the feasibility of implementing the hotspot algorithm using MapReduce. We design map and reduce functions appropriate for preprocessing of documents, and the hot spot computation. We implement the functions in Hadoop (a MapReduce framework for Apache Foundation) and conduct several experiments to assess the benefits of MapReduce style implementation versus simple sequential implementation

The Paragraph: Design and Implementation of the STAPL Parallel Task Graph

Parallel programming is becoming mainstream due to the increased availability of multiprocessor and multicore architectures and the need to solve larger and more complex problems. Languages and tools available for the development of parallel applications are often difficult to learn and use. The Standard Template Adaptive Parallel Library (STAPL) is being developed to help programmers address these difficulties. STAPL is a parallel C++ library with functionality similar to STL, the ISO adopted C++ Standard Template Library. STAPL provides a collection of parallel pContainers for data storage and pViews that provide uniform data access operations by abstracting away the details of the pContainer data distribution. Generic pAlgorithms are written in terms of PARAGRAPHs, high level task graphs expressed as a composition of common parallel patterns. These task graphs define a set of operations on pViews as well as any ordering (i.e., dependences) on these operations that must be enforced by STAPL for a valid execution. The subject of this dissertation is the PARAGRAPH Executor, a framework that manages the runtime instantiation and execution of STAPL PARAGRAPHS. We address several challenges present when using a task graph program representation and discuss a novel approach to dependence specification which allows task graph creation and execution to proceed concurrently. This overlapping increases scalability and reduces the resources required by the PARAGRAPH Executor. We also describe the interface for task specification as well as optimizations that address issues such as data locality. We evaluate the performance of the PARAGRAPH Executor on several parallel machines including massively parallel Cray XT4 and Cray XE6 systems and an IBM Power5 cluster. Using tests including generic parallel algorithms, kernels from the NAS NPB suite, and a nuclear particle transport application written in STAPL, we demonstrate that the PARAGRAPH Executor enables STAPL to exhibit good scalability on more than $10^4$ processors

CHORUS Deliverable 2.1: State of the Art on Multimedia Search Engines

Based on the information provided by European projects and national initiatives related to multimedia search as well as domains experts that participated in the CHORUS Think-thanks and workshops, this document reports on the state of the art related to multimedia content search from, a technical, and socio-economic perspective. The technical perspective includes an up to date view on content based indexing and retrieval technologies, multimedia search in the context of mobile devices and peer-to-peer networks, and an overview of current evaluation and benchmark inititiatives to measure the performance of multimedia search engines. From a socio-economic perspective we inventorize the impact and legal consequences of these technical advances and point out future directions of research

An automated system to search, track, classify and report sensitive information exposed on an intranet

Tese de mestrado em Segurança Informática, Universidade de Lisboa, Faculdade de Ciências, 2015Through time, enterprises have been focusing their main attentions towards cyber attacks against their infrastructures derived from the outside and so they end, somehow, underrating the existing dangers on their internal network. This leads to a low importance given to the information available to every employee connected to the internal network, may it be of a sensitive nature and most likely should not be available to everyone’s access. Currently, the detection of documents with sensitive or confidential information unduly exposed on PTP’s (Portugal Telecom Portugal) internal network is a rather time consuming manual process. This project’s contribution is Hound, an automated system that searches for documents, exposed to all employees, with possible sensitive content and classifies them according to its degree of sensitivity, generating reports with that gathered information. This system was integrated in a PT project of larger dimensions, in order to provide DCY (Cybersecurity Department) with mechanisms to improve its effectiveness on the vulnerability detection area, in terms of exposure of files/documents with sensitive or confidential information in its internal network.Ao longo do tempo, as empresas têm vindo a focar as suas principais atenções para os ataques contra as suas infraestruturas provenientes do exterior acabando por, de certa forma, menosprezar os perigos existentes no interior da sua rede. Isto leva a que não dêem a devida importância à informação que está disponível para todos os funcionários na rede interna, podendo a mesma ser de caráter sensível e que muito provavelmente não deveria estar disponível para o acesso de todos. Atualmente, a deteção de ficheiros com informação sensível ou confidencial indevidamente expostos na rede interna da PTP (Portugal Telecom Portugal) é um processo manual bastante moroso. A contribuição deste projeto é o Hound, um sistema automatizado que procura documentos, expostos aos colaboradores, com conteúdo potencialmente sensível. Estes documentos são classificados de acordo com o seu grau de sensibilidade, gerando relatórios com a informação obtida. Este sistema foi integrado num projeto de maiores dimensões da PT de forma a dotar o Departamento de Cibersegurança dos mecanismos necessários a melhorar a sua eficácia nas áreas de deteção de vulnerabilidades, em termos de exposição de ficheiros/documentos com informação sensível ou confidencial na sua rede interna

Arizona Health Information Exchange

abstract: Arizona strives to be the national role model for the secure, interoperable health information exchange to facilitate safe, secure, high quality and cost effective health care. The purpose of the Health Information Exchange in Arizona is to improve the quality, safety and efficiency of wellness in the Arizona population by securely connecting patients and health care providers so that relevant and understandable information is available anytime, anywhere

Automated Verification of Practical Garbage Collectors

Garbage collectors are notoriously hard to verify, due to their low-level interaction with the underlying system and the general difficulty in reasoning about reachability in graphs. Several papers have presented verified collectors, but either the proofs were hand-written or the collectors were too simplistic to use on practical applications. In this work, we present two mechanically verified garbage collectors, both practical enough to use for real-world C# benchmarks. The collectors and their associated allocators consist of x86 assembly language instructions and macro instructions, annotated with preconditions, postconditions, invariants, and assertions. We used the Boogie verification generator and the Z3 automated theorem prover to verify this assembly language code mechanically. We provide measurements comparing the performance of the verified collector with that of the standard Bartok collectors on off-the-shelf C# benchmarks, demonstrating their competitiveness

WAQS : a web-based approximate query system

The Web is often viewed as a gigantic database holding vast stores of information and provides ubiquitous accessibility to end-users. Since its inception, the Internet has experienced explosive growth both in the number of users and the amount of content available on it. However, searching for information on the Web has become increasingly difficult. Although query languages have long been part of database management systems, the standard query language being the Structural Query Language is not suitable for the Web content retrieval. In this dissertation, a new technique for document retrieval on the Web is presented. This technique is designed to allow a detailed retrieval and hence reduce the amount of matches returned by typical search engines. The main objective of this technique is to allow the query to be based on not just keywords but also the location of the keywords within the logical structure of a document. In addition, the technique also provides approximate search capabilities based on the notion of Distance and Variable Length Don\u27t Cares. The proposed techniques have been implemented in a system, called Web-Based Approximate Query System, which contains an SQL-like query language called Web-Based Approximate Query Language. Web-Based Approximate Query Language has also been integrated with EnviroDaemon, an environmental domain specific search engine. It provides EnviroDaemon with more detailed searching capabilities than just keyword-based search. Implementation details, technical results and future work are presented in this dissertation