O crescente desenvolvimento de aplicações de alto desempenho é uma realidade presente nos dias atuais. Entretanto, a diversidade de arquiteturas de máquinas, incluindo monoprocessadores e multiprocessadores, clusters com ou sem máquina front-end, variedade de sistemas operacionais e implementações da biblioteca MPI tem aumentado cada dia mais. Tendo em vista este cenário, bibliotecas que proporcionem a integração de diversas implementações MPI, sistemas operacionais e arquiteturas de máquinas são necessárias. Esta tese apresenta o HyMPI, uma implementação da biblioteca MPI voltada para integração, em um mesmo ambiente distribuído de alto desempenho, nós com diferentes arquiteturas, clusters com ou sem máquina front-end, sistemas operacionais e implementações MPI. HyMPI oferece um conjunto de primitivas compatíveis com a especificação MPI, incluindo comunicação ponto a ponto, operações coletivas, inicio e termino, além de outras primitivas utilitárias. / The increasing develpment of high performance applications is a reality on current days. However, the diversity of computer architectures, including mono and multiprocessor machines, clusters with or without front-end node, the variety of operating systems and MPI implementations has growth increasingly. Focused on this scenario, programming libraries that allows integration of several MPI implementations, operating systems and computer architectures are needed. This thesis introduces HyMPI, a MPI implementation aiming integratino, on a distributed high performance system nodes with different architectures, clusters with or without front-end machine, operating systems and MPI implementations. HyMPI offers a set of primitives based on MPI specification, including point-to-point communication, collective operations, startup and finalization and some other utility functions.

A diferença na atividade terapêutica, farmacocinética e / ou farmacodinâmica entre os enantiômeros de fármacos quirais impulsionou a necessidade de estudar e desenvolver métodos para determinação exata e precisa da pureza enantiomérica dos produtos farmacêuticos. Inicialmente, os enantiômeros foram separados em escala analítica. As condições analíticas foram adaptadas para a escala semi-preparativa para a obtenção enantiômeros puros. Os enantiômeros do bisoprolol foram separados através de Cromatografia Líquida de Alta Eficiência. Foi adotado o sistema direto de separação, fase normal, utilizando coluna Chiralcel OD (250 x 4,6 mm id). A fase móvel foi composta por hexano: etanol: dietilamina (80:20:0.2, v / v / v), vazão de 1mL/min e detecção em UV a 273 nm. A separação dos enantiômeros (R)-bisoprolol e (S)-bisoprolol foi obtida com sucesso em escala analítica e semi-preparativa. Considerando as características de uma separação quiral, podemos concluir que os resultados são eficazes, por ser uma separação rápida e seletiva. / The difference in therapeutic activity, pharmacokinetics, and / or pharmacodynamics between enantiomers of chiral drugs has raised the need to study and develop methods for accurate and precise determination of enantiomeric purity of pharmaceutical products. Initially, the enantiomers were separation in analytical scale. The analytical conditions were scaled up to semi-preparative level to obtain pure enantiomers. The enantiomers of bisoprolol were separated with high-performance liquid chromatography. Direct separation system was adopted in normal phase mode using Chiralcel OD column (250 x 4.6 mm id). The mobile phase was composed of hexane:ethanol:diethylamine (80:20:0.2, v/v/v), flow rate of 1mL/min and UV detection was made at 273 nm. The separation of enantiomers, (R)-bisoprolol and (S)-bisoprolol was successfully obtained in analytical and semi-preparative scale. Considering the characteristics of a chiral separation, we can conclude that the results are effective, because it is a fast and selective separation.

O uso de adições minerais no concreto como substituição parcial ao cimento Portland ajuda a preservar os recursos naturais poupando a matéria-prima, reduzindo o consumo de energia necessária para a produção do cimento e reciclando rejeitos que se lançados no meio ambiente causariam problemas ambientais e de saúde pública. A adição mineral que vem tendo muito destaque devido à sua alta reatividade, considerada por vários pesquisadores como uma superpozolana, é a sílica ativa (SA), um subproduto da fabricação de silício metálico ou ligas de ferro-silício. A sílica ativa se caracteriza por uma elevada finura e alta área específica e um alto teor de sílica vítrea, estes fatores somados garantem à SA a alta reatividade com o hidróxido de cálcio, transformando-o em silicato de cálcio hidratado. A casca do arroz vem sendo pesquisada como uma fonte alternativa de sílica ativa. A sílica ativa extraída da casca de arroz contém um alto teor de SiO2 e, dependendo do processo de extração, possui propriedades adequadas para a utilização na confecção de concretos de elevado desempenho. Este trabalho visa estudar a atividade pozolânica da sílica da casca de arroz produzida no laboratório de materiais avançados à base de cimento. Para avaliar as características das sílicas, foram realizados ensaios tanto para determinação das suas propriedades físicas quanto para a determinação de sua composição química e pozolanicidade. Os ensaios realizados foram:composição química, pozolanicidade (método Chapelle modificado), área superficial B.E.T., distribuição granulométrica, distribuição do tamanho de partículas via MEV, amorficidade (por difratometria de raio X), massa específica e determinação do índice de atividade pozolânica com cimento Portland (NBR-5752). Os ensaios de caracterização demonstraram que a sílica da casca de arroz possui um alto grau de amorficidade e elevada área superficial, que garantiram uma maior reatividade nas idades iniciais, porém em idades avançadas apresentou a mesma eficiência que a sílica de ferro-silício. / The use of mineral additions in concrete in order to partially replace Portland cement helps to protect natural resources by saving raw material, reducing energy consumption in cement production and recycling industrial waste that could otherwise cause environmental and public health hazards. One mineral addition that has drawn considerable attention due to its high reactivity is silica fume (SF), a byproduct of the manufacturing process of metallic silicon or iron-silicon alloys and considered by many researchers as a superpozzolan. Silica fume is characterizated by high fineness, high specific area and high content of vitreous silica. The sum of these factors provides SF high reactivity with calcium hydroxide, which is transformed into hydrated calcium silicate. Rice husk ash has also been investigated as an alternative source of silica fume. The silica from rice husk ash contains a high percentage of SiO2 and, depending on the extraction process, has adequate properties to be employed in the manufacturing of high-performance concrete. The objective of this work is to study the pozzolanic activity of silica from rice husk ash produced at the Laboratório de Materiais Avançados à Base de Cimento. In order to evaluate the characteristics of silica samples from rice husk, assays were performed to determine their physical properties as well as their chemical composition and pozzolanicity. The assays performed were: chemical composition,pozzolanicity (modified Chapelle method), B.E.T. surface area method, granulometric distribution, particle size distribution by Scanning Electron Microscope (SEM), amorphicity by X-ray diffractometry (XRD), specific mass and pozzolanic activity index determination with Portland cement (NBR-5752). The characterization assays showed that the silica from rice husk ash has a high amorphicity level and a high surface area, which yield higher reactivity at initial ages. However, at advanced ages it pesented the same efficiency as that of silica from iron-silicon.

A presente pesquisa trata da investigação experimental do comportamento de pilares por meio de encamisamento com concreto de alta resistência. Os principais objetivos da pesquisa são estudar o comportamento ao longo do tempo e o efeito de précarregamento nos pilares reforçados. Foram ensaiados vinte modelos experimentais, variando-se a forma da seção transversal (circular e quadrada), a taxa de armadura transversal da camisa de reforço e a existência ou não de pré-carregamento. Foram também realizados ensaios complementares sobre pilares curtos de seção circular para observação dos efeitos de confinamento. Ensaios de caracterização dos concretos utilizados sob ações de longa duração foram realizados. Para estudar a influência da deformação lenta, simulou-se nesta pesquisa pilares de concreto armado submetidos a pré-carregamento, os quais foram mantidos durante um certo período de tempo numa câmara climatizada. Estes pilares foram reforçados sem que fosse retirada a força de pré-carregamento.Todos os pilares foram submetidos ensaios à compressão axial de curta duração por meio de uma máquina universal de ensaios servo-hidráulica, em modo de controle de deslocamento. Na análise dos resultados foram aplicados modelos de cálculo do efeito de confinamento, análise numérica pelo Método dos Elementos Finitos e outras formulações teóricas, para efeito de confrontação de resultados teóricos e experimentais. As principais conclusões são de que, no reforço por encamisamento de pilares, uma vez garantidas adequadas condições de confinamento: a capacidade resistente do pilar original pode ser totalmente considerada na avaliação da resistência do elemento reforçado; o efeito de pré-carregamento de um pilar reforçado não afeta a resistência última do elemento reforçado, mas pode afetar a sua deformabilidade. Além disso, na análise do comportamento dos pilares ao longo do tempo, pôde-se perceber que houve transferência de esforços entre o pilar original e a camisa de reforço, mas seu efeito foi pouco significativo em termos de alteração da capacidade resistente / The thesis presents an experimental investigation on the behavior of RC columns strengthened by high-performance concrete jackets. The main objectives are to analyze the immediate and time-dependant behavior of the elements and the preloading effect in its load capacity and deformability. Twenty columns were tested varying the transversal section shape (circular and square), transversal reinforcement ratio of the jacket and the preloading condition. Also complimentary tests were made on short circular section columns to observe confinement effects. A set of long-term tests was made to characterize the concrete immediate and time-dependant properties. To analyze the influence of time-dependant deformations, original columns were submitted to preloading forces and they were kept in a weather-controlled chamber during a certain period. The high-performance concrete jackets were applied to the original columns without removing the preloading forces. Every column was subjected to a monotonic axial compression test in a servohydraulic universal machine, in the displacement-controlled mode. In the analysis of the results theoretical models of concrete confinement, Finite Element Method simulations and other formulations were applied to examine the experimental results. The main conclusions are that, if adequate confinement conditions are maintained in the strengthened columns: the load capacity of the original column can be totally considered in strength evaluation; the preloading effect does not affect the ultimate load of the rehabilitated member, but it may affect the column deformability. Moreover, in the long-term behavior analysis, load transfer between the original column and jacket was observed. However, its effect was not significant in the load capacity of the strengthened member

Leong Monk Ping. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (p. 255-278). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. Ann Arbor, MI : ProQuest Information and Learning Company, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.

Designs of human-computer systems intended for time-critical multitasking can benefit from an understanding of the human factors that support or limit multitasking performance and a detailed account of the human-machine interactions that unfold in a given task environment. An integrated, computational cognitive model can test and provide such an understanding of the human factors related to multitasking and reveal the dynamic interactions that occur in the task at the level of hundreds of milliseconds. This dissertation provides such a detailed computation model of human multitasking, built for a time-critical, multimodal dual task experiment and validated by the eye tracking data collected from the experiment. This dissertation also develops new approaches to conducting cognitive modeling, which enable efficient and systematical exploration of multitasking strategies, as well as principled model comparisons. The dual task experiment captures many key aspects of real-world multitasking scenarios such as driving. In the experiment, the participant interleaved two tasks: one requires tracking a constantly-moving target with a joystick, and the other requires keying-in responses to objects moving across a radar display. Peripheral visibility and auditory conditions of the experiment were manipulated to assess the influence of peripheral visual information and auditory information on multitasking performance. Detailed eye tracking data were collected, and this dissertation presents a detailed analysis of this set of data, which provides the bases for model development and validation. The cognitive model presented in this dissertation, built based on the Executive Processes-Interactive Control cognitive architecture, accurately accounted for the eye movement data and other behavioral data of each participant using systematic explorations of task strategies and parameters configured for each individual participant. A parallelized cognitive modeling system was developed to accommodate the much increased computational demand of strategy exploration and individualized model building. New model comparison techniques were proposed to determine which strategy best accounts for the empirical data. Payoff analyses were applied, and they revealed people’s tendency to locally optimize task performance based on task payoff as well as instantaneous feedback. The results point to new approaches for building a priori models that predict multitasking performance. This dissertation includes previously published coauthored material.

The price of computers has dropped drastically over the past years enabling many households to have at least one computer. At the same time, the performance of computers has skyrocketed, far surpassing what a typical user needs, and most of the computational power of personal computers is wasted. Volunteer computing projects attempt to use this wasted computational power in order to solve problems that would otherwise be computationally infeasible. Some of these problems include medical applications like searching for cures for AIDS and cancer. However, the number of volunteer computing projects is increasing rapidly, requiring improvements in the field of volunteer computing to enable the increasing number of volunteer projects to continue making significant progress. This dissertation examines two ways to increase the productivity of volunteer computing: using the volunteered CPU cycles more effectively and exploring ways to increase the amount of CPU cycles that are donated. Each of the existing volunteer computing projects uses one of two task retrieval policies to enable the volunteered computers participating in projects to retrieve work. This dissertation compares the amount of work completed by the volunteered computers participating in projects based on which of the two task retrieval techniques the project employs. Additional task retrieval policies are also proposed and evaluated. The most commonly used task retrieval policy is shown to be less effective than both the less frequently used policy and a proposed policy. The potential that video game consoles have to be used for volunteer computing is explored, as well as the potential benefits of constructing different types of volunteer computing clients, rather than the most popular client implementation: the screensaver. In addition to examining methods of increasing the productivity of volunteer computing, 140 traces of computer usage detailing when computers are available to participate in volunteer computing is collected and made publicly available. Volunteer computing project-specific information that can be used in researching how to improve volunteer computing is collected and combined into the first summary of which we are aware.

Understanding the performance of applications on modern multi- and manycore platforms is a difficult task and involves complex measurement, analysis, and modeling. The Roofline model is used to assess an application's performance on a given architecture. Not much work has been done with the Roofline model using real measurements. Because it can be a very useful tool for understanding application performance on a given architecture, in this thesis we demonstrate the use of architectural roofline data with measured data for analyzing the performance of different benchmarks. We first explain how to use different toolkits to measure the performance of a program. Next, these data are used to generate the roofline plots, based on which we can decide how can we make the application more efficient and remove bottlenecks. Our results show that this can be a powerful tool for analyzing performance of applications over different architectures and different code versions.

The desire for high performance on scalable parallel systems is increasing the complexity and the need to tune MPI implementations. The MPI Tools Information Interface (MPI T) introduced in the MPI 3.0 standard provides an opportunity for performance tools and external software to introspect and understand MPI runtime behavior at a deeper level to detect scalability issues. The interface also provides a mechanism to fine-tune the performance of the MPI library dynamically at runtime. This thesis describes the motivation, design, and challenges involved in developing an MPI performance engineering infrastructure using MPI T for two performance toolkits — the TAU Performance System, and Caliper. I validate the design of the infrastructure for TAU by developing optimizations for production and synthetic applications. I show that the MPI T runtime introspection mechanism in Caliper enables a meaningful analysis of performance data. This thesis includes previously published co-authored material.

L'utilisation du kaolin calciné, sous forme de métakaolin, comme matériau pouzzolanique pour le mortier et le béton a suscité une attention considérable ces dernières années. Le travail actuel décrit les résultats d'un projet de recherche lancé pour étudier la calcination d'un kaolin local sous diverses températures (650-950°C) et durées (2, 3 et 4 heures) qui ont produit le métakaolin avec une activité pouzzolanique élevée. L'activité pouzzolanique a été évaluée par des méthodes de la chaleur d'hydratation et la résistance à la compression à 28 jours. L'activité maximale a été obtenue à une température de 850°C pendant 3 heures. Les résultats observés établissent qu'une augmentation de la chaleur d'hydratation et de la résistance à la compression a été obtenue lorsque le ciment Portland Ordinaire a été remplacé par 10% de métakaolin. L'utilisation du ciment ternaire améliore la résistance au jeune âge et à long terme. La durabilité a été également améliorée où une meilleure résistance des mortiers à l'attaque des acides a été observée. / The utilisation of calcined clay, in the form of metakaolin as a pozzolanic material for mortar and concrete has received considerable attention in recent years. The present work describes the results of a research project initiated to study the calcination of a local kaolin at various temperatures (650-950°C) and durations (2, 3 and 4 hours) to produced a metakaolin with a high pozzolanic activity. The pozzolanic activity was assessed by 28-days compressive strength and hydration heat methods. The maximum identified activity was obtained at 850°C for 3 hours duration. The observed results establish that an increase of both hydration heat and compressive strength was obtained when ordinary Portland cement was replaced by 10% metakaolin. The use of ternary blended cement improves the early age and the long-term compressive strength. The durability was also enhanced as better acidic resistance was observed.