There are many practical decision problems that fall into the category of network flow problems: numerous examples of applications can be found in areas such as telecommunications, logistics, distributions, engineering, computer science and so on. One of the most popular and valuable tools to solve network flow problems of a topological nature is the use of linear programming models. An important extension of these models is that of integer programming models that deal with problems where some, or all, of the variables are required to assume integer variables. A significant application in this class of problems is the knapsack problem that arises in different contexts such as loading containers in aircraft or satisfying the demand for various lengths of cloth which must be cut from fixed length bolts of fabric. In this study, the feasibility of representing a network flow model in a tree network model and subsequently solving it using a tree knapsack approach is investigated. To compare and validate the proposed technique, a specific case study was chosen from the literature that can be used as a basis for the research project. The said study was an oil pipeline design problem, addressed by Brimberg et al. (2003). This focuses on the optimal design of an oil pipeline network for the South Gabon oil field in Africa. The objective was to reduce oil transportation costs to a major port. Following an overview of different network flow and knapsack models, an overview of the said matter is presented. A description of the proposed tree knapsack approach and the application of this approach to the given problem is given. Results have indicated that it is feasible to apply a tree knapsack approach to solve network flow problems. / Thesis (M.Sc. (Computer Science))--North-West University, Potchefstroom Campus, 2011.

Understanding human behaviour is key to understanding the spread of epidemics, habit dispersion, and the efficacy of health interventions. Investigation into the patterns of and drivers for human behaviour has often been facilitated by paper tools such as surveys, journals, and diaries. These tools have drawbacks in that they can be forgotten, go unfilled, and depend on often unreliable human memories. Researcher-driven data collection mechanisms, such as interviews and direct observation, alleviate some of these problems while introducing others, such as bias and observer effects. In response to this, technological means such as special-purpose data collection hardware, wireless sensor networks, and apps for smart devices have been built to collect behavioural data. These technologies further reduce the problems experienced by more traditional behavioural research tools, but often experience problems of reliability, generality, extensibility, and ease of configuration. This document details the construction of a smartphone-based app designed to collect data on human behaviour such that the difficulties of traditional tools are alleviated while still addressing the problems faced by modern supplemental technology. I describe the app's main data collection engine and its construction, architecture, reliability, generality, and extensibility, as well as the programming language developed to configure it and its feature set. To demonstrate the utility of the tool and its configuration language, I describe how they have been used to collect data in the field. Specifically, eleven case studies are presented in which the tool's architecture, flexibility, generality, extensibility, modularity, and ease of configuration have been exploited to facilitate a variety of behavioural monitoring endeavours. I further explain how the engine performs data collection, the major abstractions it employs, how its design and the development techniques used ensure ongoing reliability, and how the engine and its configuration language could be extended in the future to facilitate a greater range of experiments that require behavioural data to be collected. Finally, features and modules of the engine's encompassing system, iEpi, are presented that have not otherwise been documented to give the reader an understanding of where the work fits into the larger data collection and processing endeavour that spawned it.

This thesis analyses Turkey&rsquo / s energy policies and Turkey&rsquo / s foreign relations through the energy issues in the Eurasian region. In the first phase, the energy policies implemented by the state and free market orientation in Turkish energy sector will be discussed. The impacts of neo-liberal economic policies, regional organizations (the European Union and OECD), and global finance institutions (International Monetary Fund &ndash / the IMF and the World Bank &ndash / WB) on Turkish energy sub-sectors, particularly since the beginning of the 1980s, will be examined. In the second phase, Turkey&rsquo / s own autonomy and effectiveness within major energy pipeline projects in the Eurasian energy axis will be questioned in the post-Cold War period. Turkey&rsquo / s relations in the energy issues with the European Union, Middle East, Caucasus and Turkic States, Russia and the United States (US) will be discussed. Basic vulnerabilities in Turkish energy sector and possible acquisitions of Turkey through its international energy deals will be emphasized.

This dissertation attacks the well-known problem of path-imprecision in static program analysis. Our starting point is an existing static program analysis that over-approximates the execution paths of the analyzed program. We then make this over-approximating program analysis more precise for automatic testing in an object-oriented programming language. We achieve this by combining the over-approximating program analysis with usage-observing and under-approximating analyses. More specifically, we make the following contributions. We present a technique to eliminate language-level unsound bug warnings produced by an execution-path-over-approximating analysis for object-oriented programs that is based on the weakest precondition calculus. Our technique post-processes the results of the over-approximating analysis by solving the produced constraint systems and generating and executing concrete test-cases that satisfy the given constraint systems. Only test-cases that confirm the results of the over-approximating static analysis are presented to the user. This technique has the important side-benefit of making the results of a weakest-precondition based static analysis easier to understand for human consumers. We show examples from our experiments that visually demonstrate the difference between hundreds of complicated constraints and a simple corresponding JUnit test-case. Besides eliminating language-level unsound bug warnings, we present an additional technique that also addresses user-level unsound bug warnings. This technique pre-processes the testee with a dynamic analysis that takes advantage of actual user data. It annotates the testee with the knowledge obtained from this pre-processing step and thereby provides guidance for the over-approximating analysis. We also present an improvement to dynamic invariant detection for object-oriented programming languages. Previous approaches do not take behavioral subtyping into account and therefore may produce inconsistent results, which can throw off automated analyses such as the ones we are performing for bug-finding. Finally, we address the problem of unwanted dependencies between test-cases caused by global state. We present two techniques for efficiently re-initializing global state between test-case executions and discuss their trade-offs. We have implemented the above techniques in the JCrasher, Check 'n' Crash, and DSD-Crasher tools and present initial experience in using them for automated bug finding in real-world Java programs.

Thesis (Ph. D.)--University of Missouri-Columbia, 2002. / Typescript. Vita. Includes bibliographical references (leaves 198-201). Also available on the Internet.

Amostras de DNA são encontradas em fragmentos, obtidos em vestígios de uma cena de crime, ou coletados de amostras de cabelo ou sangue, para testes genéticos ou de paternidade. Para identificar se esse fragmento pertence ou não a uma sequência de DNA, é necessário compará-los com uma sequência determinada, que pode estar armazenada em um banco de dados para, por exemplo, apontar um suspeito. Para tal, é preciso uma ferramenta eficiente para realizar o alinhamento da sequência de DNA encontrada com a armazenada no banco de dados. O alinhamento de sequências de DNA, em inglês DNA matching, é o campo da bioinformática que tenta entender a relação entre as sequências genéticas e suas relações funcionais e parentais. Essa tarefa é frequentemente realizada através de softwares que varrem clusters de base de dados, demandando alto poder computacional, o que encarece o custo de um projeto de alinhamento de sequências de DNA. Esta dissertação apresenta uma arquitetura de hardware paralela, para o algoritmo BLAST, que permite o alinhamento de um par de sequências de DNA. O algoritmo BLAST é um método heurístico e atualmente é o mais rápido. A estratégia do BLAST é dividir as sequências originais em subsequências menores de tamanho w. Após realizar as comparações nessas pequenas subsequências, as etapas do BLAST analisam apenas as subsequências que forem idênticas. Com isso, o algoritmo diminui o número de testes e combinações necessárias para realizar o alinhamento. Para cada sequência idêntica há três etapas, a serem realizadas pelo algoritmo: semeadura, extensão e avaliação. A solução proposta se inspira nas características do algoritmo para implementar um hardware totalmente paralelo e com pipeline entre as etapas básicas do BLAST. A arquitetura de hardware proposta foi implementada em FPGA e os resultados obtidos mostram a comparação entre área ocupada, número de ciclos e máxima frequência de operação permitida, em função dos parâmetros de alinhamento. O resultado é uma arquitetura de hardware em lógica reconfigurável, escalável, eficiente e de baixo custo, capaz de alinhar pares de sequências utilizando o algoritmo BLAST. / DNA samples are found in fragments, obtained in traces of a crime scene, collected from hair or blood samples, for genetic or paternity tests. To identify whether this fragment belongs or not to a given DNA sequence it is necessary to compare it with a determined sequence which usually come from a database, for instance, to point a suspect. To this end, we need an efficient tool to perform the alignment of the DNA sequence found with the ones stored in the database. The alignment of DNA sequences, which is a field of bioinformatics that helps to understand the relationship between genetic sequences and their functional relationships and parenting. This task is often performed by software that scan clusters of databases, which requires high computing effort, thus increasing the cost of DNA sequences alignment projects. This work presents a parallel hardware architecture, for BLAST algorithm, to DNA pairwise alignment. This is the original version of the BLAST algorithm, that resulted in several other versions. The BLAST algorithm is a heuristic method and is the fastest algorithm for sequence alignment. The strategy of BLAST is to divide the sequences into smaller subsequences of size w. After making comparisons in these subsequences, algorithm steps analyzes only the subsequences that are identical. Thus, reducing the number of tests and combinations needed to perform the alignment. For each identical sequence found, three steps are followed by the algorithm: seeding, extension and evaluation. The proposed hardware architecture is based on the characteristics of the algorithm to implement a fully parallel hardware, where the basic steps of BLAST are pipelined. The proposed architecture was implemented in FPGA and the results show a comparison between the area occupied, number of cycles and maximum frequency of operation permitted, as a function of alignment parameters. The result is a hardware architecture in reconfigurable logic, scalable, efficient and with low cost, capable of aligning the pairs of sequences using BLAST algorithm.

Last August marked 10 years since the start of the Camisea project, and it is undeniable the influence that it has had in Peru. However, it is also unquestionable that during the last decade, the country has suffered from critic mismanagement, called «centralism». In this context, the author gives an overview of the state of the natural gas industry in Peru. Finally, he makes reference to researches aimed at gaining access to natural gas outside the capital. / El pasado mes de agosto se cumplieron 10 años desde el inicio de operación del proyecto Camisea, y es innegable la influencia que ha tenido este proyecto en el Perú. Sin embargo, también resulta incuestionable que en esta última década el país ha padecido de una crítica mala gestión, llamada «centralismo». En este contexto, el autor hace un repaso de la situación de la industria del gas natural en el Perú. Finalmente, hace referencia a investigaciones destinadas a lograr el acceso al gas natural fuera de la capital.

[pt] Oleodutos têm um papel importante no transporte de petróleo e de seus derivados, pois são a maneira mais eficaz de transportar grandes volumes por longas distâncias. A motivação deste trabalho é que uma parte não negligenciável do preço final de um derivado de petróleo é influenciada pelo custo de transporte. Apesar disso, até onde sabemos, apenas alguns autores trabalharam neste problema específico, a maioria utilizando técnicas de programação inteira. Este trabalho analisa a utilização de técnicas de inteligência artificial, arcabouços de software e simulação discreta orientada a eventos para a construção de planejadores automáticos capazes de lidar com instâncias reais de problemas de transporte em oleodutos. A primeira contribuição dessa tese é a especificação de um novo domínio para problemas de planejamento, denominado PIPESWORLD. Este domínio é inspirado no problema de transporte em oleodutos e especificado em PDDL. Por sua estrutura original, ele foi incorporado ao benchmark oficial da 4th International Planner Competition, evento bi-anual que compara o desempenho de diversos planejadores automáticos de propósito geral. Mesmo sendo uma simplificação do problema original, o PIPESWORLD se mostra um domínio bastante desafiador para o estado da arte dos planejadores. É demonstrado também que problemas de decisão derivados de diversas configurações do Pipesworld são NP-Completos. A segunda contribuição dessa tese é o arcabouço de software PLANSIM. Este framework incorpora uma máquina de busca que pode utilizar diversas estratégias, e define uma estrutura que facilita a construção de planejadores automáticos baseados em busca heurística direta que utilizam como modelo do processo a ser planejado simuladores orientados a eventos discretos. São apresentadas instanciações do PLANSIM para a construção de planejadores para problemas clássicos de como o das Torres de Hanoi e Blocksworld. A terceira contribuição da tese é a instanciação do PLANSIM para a construção de um planejador automático capaz de tratar instâncias reais de planejamento de transporte em oleodutos, denominado PLUMBER 05. A utilização de técnicas de simulação discreta orientada a eventos para a representação do modelo do sistema a ser planejado permite que este seja bastante fiel ao problema original. Isto somado ao uso do PLANSIM facilita a construção de planejadores capazes de lidar com instâncias reais. / [en] Pipelines have an important role in oil and its derivatives transportation, since they are the most effective way to transport high volumes through long distances. The motivation for this work is that a non negligible part of the final price for those products are due to transportation costs. Few authors have addressed this problem, with most of the previous work using integer programming techniques. This work analyses the use of Artificial Intelligence techniques, discrete event simulators and software frameworks for building automated planners that are able to deal with real-world oil pipeline transportation instances. The first contribution of this thesis is the specification of a new planning domain called PIPESWORLD. This domain is inspired by the oil pipeline transportation problem, and is defined in PDDL. Due to its original structure, the PIPESWORLD domain has been incorporated to the 4th International Planning Competition benchmark. Even being a simplification of the original problem, PIPESWORLD instances in the benchmark are challenging to state of art solvers. It is also shown that decision problems based on PIPESWORLD configurations are NP-Hard. The second contribution of this thesis is the PLANSIM opensource framework. This framework incorporates a search engine that may use several different strategies, and defines a structure that facilitates the construction of automated planners based on heuristic forward search that use discrete event simulators as the model for the process to be planned. The third contribution of this thesis is a PLANSIM instantiation that results in an automated planner able to deal with real-world oil pipeline transportation instances, called PLUMBER 2. The use of discrete event simulation techniques for the model of the system to be planned allows this model to be very close to the original problem. This, in conjunction with PLANSIM usage, facilitates the construction of planners that are able to cope with real-world instances.

A presente pesquisa propõe estabelecer uma discussão em torno da integração supranacional de infra-estruturas energéticas, tendo como enfoque principal a rede de gasodutos. Entende-se que a expansão de infra-estruturas energéticas acaba gerando repercussões diferenciadas no território, tanto na escala supranacional quanto na escala regional/local. Desde a flexibilização do setor de petróleo no Brasil, em meados da década de 1990, a Petrobras vem expandindo significativamente sua atuação internacional, onde o gás natural é colocado como os dos principais objetivos para exploração. Considera-se fundamental entender os principais aspectos do processo de integração supranacional de infraestruturas energéticas, assim como as principais repercussões territoriais após a introdução de um novo insumo energético na escala local/regional, no caso específico desta pesquisa, a Região Metropolitana de Porto Alegre - RMPA. Estas repercussões são mensuradas através de uma amostra do setor industrial da RMPA, onde se procura analisar a importância da inserção do gás natural para este setor, manifestado através da destinação e conversão do consumo energético, atração de novos investimentos e até mesmo mobilidade territorial. / The present research aims at establishing a discussion about the supranational integration of the energetic infrastructure, having as its main focus the gas pipeline network. We understand that the expansion of energetic infrastructures generate differentiated repercussions in the territory at both the supranational and regional/local scales. Since the flexibilization of the petrol sector in Brazil, in the middle 1990s, the international participation of Petrobras has been growing significantly, and the natural gas is placed as one of the main objectives for the exploration. Therefore, it is fundamental to understand the main aspects of the process of international integration of the energetic infrastructures, as well as the main territorial repercussions after the introduction of the new energetic input at the local/regional scale, more specifically, the metropolitan region of Porto Alegre – RMPA. These repercussions are measured through a sample of the industrial sector of RPMA, where we try to analyze the importance of the insertion of the natural gas for this sector, manifested through the destination and conversion of the energetic consume, attraction of new investments, as well as territorial mobility.

Amostras de DNA são encontradas em fragmentos, obtidos em vestígios de uma cena de crime, ou coletados de amostras de cabelo ou sangue, para testes genéticos ou de paternidade. Para identificar se esse fragmento pertence ou não a uma sequência de DNA, é necessário compará-los com uma sequência determinada, que pode estar armazenada em um banco de dados para, por exemplo, apontar um suspeito. Para tal, é preciso uma ferramenta eficiente para realizar o alinhamento da sequência de DNA encontrada com a armazenada no banco de dados. O alinhamento de sequências de DNA, em inglês DNA matching, é o campo da bioinformática que tenta entender a relação entre as sequências genéticas e suas relações funcionais e parentais. Essa tarefa é frequentemente realizada através de softwares que varrem clusters de base de dados, demandando alto poder computacional, o que encarece o custo de um projeto de alinhamento de sequências de DNA. Esta dissertação apresenta uma arquitetura de hardware paralela, para o algoritmo BLAST, que permite o alinhamento de um par de sequências de DNA. O algoritmo BLAST é um método heurístico e atualmente é o mais rápido. A estratégia do BLAST é dividir as sequências originais em subsequências menores de tamanho w. Após realizar as comparações nessas pequenas subsequências, as etapas do BLAST analisam apenas as subsequências que forem idênticas. Com isso, o algoritmo diminui o número de testes e combinações necessárias para realizar o alinhamento. Para cada sequência idêntica há três etapas, a serem realizadas pelo algoritmo: semeadura, extensão e avaliação. A solução proposta se inspira nas características do algoritmo para implementar um hardware totalmente paralelo e com pipeline entre as etapas básicas do BLAST. A arquitetura de hardware proposta foi implementada em FPGA e os resultados obtidos mostram a comparação entre área ocupada, número de ciclos e máxima frequência de operação permitida, em função dos parâmetros de alinhamento. O resultado é uma arquitetura de hardware em lógica reconfigurável, escalável, eficiente e de baixo custo, capaz de alinhar pares de sequências utilizando o algoritmo BLAST. / DNA samples are found in fragments, obtained in traces of a crime scene, collected from hair or blood samples, for genetic or paternity tests. To identify whether this fragment belongs or not to a given DNA sequence it is necessary to compare it with a determined sequence which usually come from a database, for instance, to point a suspect. To this end, we need an efficient tool to perform the alignment of the DNA sequence found with the ones stored in the database. The alignment of DNA sequences, which is a field of bioinformatics that helps to understand the relationship between genetic sequences and their functional relationships and parenting. This task is often performed by software that scan clusters of databases, which requires high computing effort, thus increasing the cost of DNA sequences alignment projects. This work presents a parallel hardware architecture, for BLAST algorithm, to DNA pairwise alignment. This is the original version of the BLAST algorithm, that resulted in several other versions. The BLAST algorithm is a heuristic method and is the fastest algorithm for sequence alignment. The strategy of BLAST is to divide the sequences into smaller subsequences of size w. After making comparisons in these subsequences, algorithm steps analyzes only the subsequences that are identical. Thus, reducing the number of tests and combinations needed to perform the alignment. For each identical sequence found, three steps are followed by the algorithm: seeding, extension and evaluation. The proposed hardware architecture is based on the characteristics of the algorithm to implement a fully parallel hardware, where the basic steps of BLAST are pipelined. The proposed architecture was implemented in FPGA and the results show a comparison between the area occupied, number of cycles and maximum frequency of operation permitted, as a function of alignment parameters. The result is a hardware architecture in reconfigurable logic, scalable, efficient and with low cost, capable of aligning the pairs of sequences using BLAST algorithm.