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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
101

Efficient exploitation of similar subexpressions for query processing

Zhou, Jingren, Larson, Per-Ake, Freytag, Johann Christoph, Lehner, Wolfgang 13 December 2022 (has links)
Complex queries often contain common or similar subexpressions, either within a single query or among multiple queries submitted as a batch. If so, query execution time can be improved by evaluating a common subexpression once and reusing the result in multiple places. However, current query optimizers do not recognize and exploit similar subexpressions, even within the same query. We present an efficient, scalable, and principled solution to this long-standing optimization problem. We introduce a light-weight and effective mechanism to detect potential sharing opportunities among expressions. Candidate covering subexpressions are constructed and optimization is resumed to determine which, if any, such subexpressions to include in the final query plan. The chosen subexpression(s) are computed only once and the results are reused to answer other parts of queries. Our solution automatically applies to optimization of query batches, nested queries, and maintenance of multiple materialized views. It is the first comprehensive solution covering all aspects of the problem: detection, construction, and cost-based optimization. Experiments on Microsoft SQL Server show significant performance improvements with minimal overhead.
102

Temperature Relaxation and Magnetically Suppressed Expansion in Strongly Coupled Ultracold Neutral Plasmas

Sprenkle, Robert Tucker 21 December 2021 (has links)
Ultracold neutral plasmas provide a platform for studying transport properties in an idealized environment. In this dissertation, transport properties in a Ca$^+$/Yb$^+$ dual species ultracold neutral plasma and a Ca$^+$ magnetized ultracold neutral plasma are studied. In dual species plasmas, we study ion-ion temperature relaxation. We compare measured relaxation rates with atomistic simulations and a range of popular theories. Our work validates the assumptions and capabilities of molecular dynamic simulations and invalidates theoretical models in this regime. This work illustrates an approach for precision determinations of detailed material properties in Coulomb mixtures across a wide range of conditions. We also study plasma expansion in single species plasma in the presence of a strong uniform magnetic field. We find that the asymptotic expansion velocity falls exponentially with magnetic field strength, which disagrees with a previously published ambipolar diffusion model. In the parallel direction, plasma expansion is driven by electron pressure. However, in the perpendicular direction, no plasma expansion is observed at large magnetic field strengths.
103

Modelling priority queuing systems with varying service capacity

Chen, M., Jin, X.L., Wang, Y.Z., Cheng, X.Q., Min, Geyong January 2013 (has links)
No / Many studies have been conducted to investigate the performance of priority queuing (PQ) systems with constant service capacity. However, due to the time-varying nature of wireless channels in wireless communication networks, the service capacity of queuing systemsmay vary over time. Therefore, it is necessary to investigate the performance of PQ systems in the presence of varying service capacity. In addition, self-similar traffic has been discovered to be a ubiquitous phenomenon in various communication networks, which poses great challenges to performance modelling of scheduling systems due to its fractal-like nature. Therefore, this paper develops a flow-decomposition based approach to performance modelling of PQ systems subject to self-similar traffic and varying service capacity. It specifically proposes an analytical model to investigate queue length distributions of individual traffic flows. The validity and accuracy of the model is demonstrated via extensive simulation experiments.
104

Content, form and technique of traditional and modern praise poetry in Northern Sotho

Kgobe, D. M. (Dominic Mamahlo) 06 1900 (has links)
This thesis is a critical evaluation of the content, form and technique of traditional and modern praise poetry in Northern Sotho. Chapter 1 presents the aim of the study and the method of research and defines the concepts of poetry and praise poetry. Praise poetry is viewed from a traditional and modern perspective. Chapter 2 deals with the content and technique of praise poetry. Content consists of oral praise poetry lauding the heroic deeds of men in battles and casual encounters. Modern praise poetry comments on current events. Devices for rapid composition of the praises are discussed. Techniques differ between poets and according to time, place and occasion. Chapter 3 covers the traditional praises of chiefs, warriors, initiates, animals, birds, divining bones and totem praises, examining them from the perspective of content and form. The praises extol human achievements, peculiar animal characteristics and the interpretation of "mawa" of divining bones. Chapter 4 deals with the development and transition from traditional to modern form as well as the reciprocal influence. The content and form of modern praises of chiefs, academics, community leaders, animals, birds, divining bones, man-made objects and some natural phenomena are discussed. Many modern poets have also written praises of fictional characters. Chapter 5 compares oral and written praise poetry by concentrating on the similarities and differences between traditional and modern praise poetry. This study shows that there are differences in of theme, rhyme, beginning and ending, sentence length and significant emphasis on man-made objects such as cars and locomotives as exceptional modes of transport for commuters. Chapter 6 concludes the study and proves that praise poetry is a living or dynamic entity which will continue to exist. Praise poetry highlights persons, interpersonal relationships, attitudes and values derived from an African conceptions of the universe. / African Languages / D.Litt. et Phil (African Languages)
105

Právní úprava loterií a jiných podobných her / Legal regulation of lotteries and similar games

Půlpánová, Blanka January 2013 (has links)
Legal regulation of lotteries and other similar games The thesis deals with legal regulation of lotteries and other similar games not limited in the legal system of Czech Republic, but also from the perspective of European law. The main objective of this work is to analyze the legal provisions of the Act No. 202/1990 Coll., on the Lotteries and other similar games. It is a valid law, the basis adjustments operation of lotteries and other similar games in our country. The thesis is divided into the three chapters. The first chapter is subdivided into two major parts. The first part deals with the legal regulation of the lotteries and other similar games in the Czech legal order and the second part is focused on the legislation of this part of industry in the European legal order. The first part begins with a brief overview into the history of the gambling. Consequently I analyze the private law regulation with a focus on key provisions of the Act No. 40/1964 Coll., Civil Code. The largest part of the first chapter is devoted to analysis of the public law regulation of the games of chance in the relevant provisions of the Act No. 202/1990 Coll., on the Lotteries and other similar games. These are the provisions that define special properties of gambling and the specific conditions for gambling...
106

miR‐17/20 Controls Prolyl Hydroxylase 2 (PHD2)/Hypoxia‐Inducible Factor 1 (HIF1) to Regulate Pulmonary Artery Smooth Muscle Cell Proliferation

Chen, Tianji, Zhou, Qiyuan, Tang, Haiyang, Bozkanat, Melike, Yuan, Jason X.‐J., Raj, J. Usha, Zhou, Guofei 05 December 2016 (has links)
Background-Previously we found that smooth muscle cell (SMC)-specific knockout of miR-17 similar to 92 attenuates hypoxia-induced pulmonary hypertension. However, the mechanism underlying miR-17 similar to 92-mediated pulmonary artery SMC (PASMC) proliferation remains unclear. We sought to investigate whether miR-17 similar to 92 regulates hypoxia-inducible factor (HIF) activity and PASMC proliferation via prolyl hydroxylases (PHDs). Methods and Results-We show that hypoxic sm-17 similar to 92(-/-) mice have decreased hematocrit, red blood cell counts, and hemoglobin contents. The sm-17 similar to 92 (-/-) mouse lungs express decreased mRNA levels of HIF targets and increased levels of PHD2. miR-17 similar to 92 inhibitors suppress hypoxia-induced levels of HIF1 alpha, VEGF, Glut1, HK2, and PDK1 but not HIF2 alpha in vitro in PASMC. Overexpression of miR-17 in PASMC represses PHD2 expression, whereas miR-17/20a inhibitors induce PHD2 expression. The 3'-UTR of PHD2 contains a functional miR-17/20a seed sequence. Silencing of PHD2 induces HIF1a and PCNA protein levels, whereas overexpression of PHD2 decreases HIF1 alpha and cell proliferation. SMC-specific knockout of PHD2 enhances hypoxia-induced vascular remodeling and exacerbates established pulmonary hypertension in mice. PHD2 activator R59949 reverses vessel remodeling in existing hypertensive mice. PHDs are dysregulated in PASMC isolated from pulmonary arterial hypertension patients. Conclusions-Our results suggest that PHD2 is a direct target of miR-17/20a and that miR-17 similar to 92 contributes to PASMC proliferation and polycythemia by suppression of PHD2 and induction of HIF1 alpha.
107

A chave de Jano: os trajetos da criação de Avalovara de Osman Lins: uma leitura das notas de planejamento à luz da Crítica Genética / The key of Jano: the paths of the creation of Avalovara by Osman Lins: a reading of the planning notes in light of the Genetic Criticism

Pereira, Eder Rodrigues 03 July 2009 (has links)
Esta dissertação apresenta a edição fac-similar e diplomática em perspectiva genética de 53 notas de planejamento do romance Avalovara de Osman Lins. Esta seleção permitiu verificar quais foram os procedimentos empregados na composição do texto, da estrutura rigorosa do livro e o registro da utilização destas notas na obra publicada em 1973. A edição contempla documentos autógrafos, datiloscritos e impressos rasurados que, de modo geral, contêm um discurso indicativo. Com isso, é possível perceber certas particularidades relacionadas ao processo de criação do romance além de estabelecer novas propostas de estudo para a obra. / This dissertation presents the diplomatic and fac-simile edition of 53 planning notes of the Avalovara, a novel by Osman Lins, through a genetic perspective. The selection was limited to these documents in order to check the procedures employed in the text composition and in its rigorous structure, as well as the record of the use of these notes in the volume published in 1973. The edition includes handwritten, typed and scrapped printed documents that, in general, display an indicative discourse. Through this edition, it is possible both to notice certain peculiarities related to the creative process of the novel and to establish new perspectives of study for the novel.
108

Circuitos resistivos autossimilares / Autossimilar resistive circuits

Santos, Claudio Xavier Mendes dos 07 March 2016 (has links)
Esse trabalho é um estudo sobre circuitos resistivos que apresentam a característica da autossimilaridade em sua configuração. A construção desses circuitos é feita de uma maneira recursiva, de forma análoga a um fractal autossimilar. Os circuitos são analisados pelas suas resistências equivalentes, sendo obtida uma condição para convergência desse valor. Os conceitos auxiliares necessários ao tema desta dissertação abordam a representação de um circuito resistivo como um grafo, além de conceitos envolvendo fractais autossimilares. São propostas ao final de cada capítulo atividades interdisciplinares acessíveis a alunos de ensino médio, com conteúdos envolvendo resistência equivalente, sequências, conjuntos, e noções de área e perímetro. / This work is a study of resistive circuits which present a characteristic of self similarity in their configuration. The construction of these circuits is made in a self recursive way, analogously to a self similar fractal. The circuits are analyzed by their equivalent resistance, and a condition for convergence of this quantity is obtained. Auxiliary concepts that are necessary to this dissertation theme treat the resistive circuit as a graph, and concepts involving self similar fractals. It is proposed at the end of each chapter interdisciplinary activities that are accessible to high school students, with topics involving equivalent resistence, sequences, sets, and notions of area and perimeter.
109

Intercambialidade entre medicamentos genéricos e similares de um mesmo medicamento de referência / Interchangeability among generic and similar drug products of a same reference drug product

Freitas, Marcia Sayuri Takamatsu 05 December 2016 (has links)
A implementação de medicamentos genéricos no Brasil e de programas e políticas para garantir o acesso da população a medicamentos com qualidade, segurança e eficácia resultaram em mais de 3.800 medicamentos genéricos de 445 fármacos registrados na Agência Nacional de Vigilância Sanitária (ANVISA) desde 1999. Os medicamentos genéricos comprovaram a sua equivalência terapêutica e, portanto, intercambialidade com seus respectivos medicamentos de referência por meio de estudos de bioequivalência. Em 2014, a ANVISA estendeu a intercambialidade aos medicamentos similares, aumentando o número de medicamentos intercambiáveis para cada medicamento de referência. As normas para prescrição e dispensação permitem apenas a substituição de medicamento de referência por seu medicamento genérico ou similar intercambiável e vice-versa. Entretanto, o que se observa na prática é a substituição entre medicamentos genéricos e similares de um mesmo fármaco, tanto na rede privada onde os descontos chegam até 90% do preço estabelecido para a venda, como na rede pública, em função da disponibilidade dos medicamentos, visto que as compras públicas se baseiam no menor preço ofertado pelos fabricantes. Entretanto, a bioequivalência e a intercambialidade entre os medicamentos genéricos ou similares de um mesmo referência não pode ser garantida pois os mesmos não foram testados entre si. A ausência de bioequivalência entre medicamentos substituídos pode provocar ineficácia terapêutica ou aparecimento de eventos adversos ou até mesmo intoxicação em pacientes. Consequentemente, podem ocorrer desperdício, gastos com tratamento de eventos adversos, abandono do tratamento e adoção de segunda linha de tratamentos. Este trabalho avaliou a bioequivalência entre os medicamentos genéricos e similares de um mesmo medicamento de referência por meio do método de metanálise, empregando dados de estudos de bioequivalência realizados para o registro de medicamentos genéricos e similares na ANVISA. Foram incluídos na análise estudos de aciclovir, amoxicilina, cefalexina, doxazosina, fenitoína, fluoxetina, levofloxacino e quetiapina. Os resultados demonstraram a ausência de bioequivalência entre a maioria dos medicamentos genéricos e similares contendo o mesmo fármaco. os resultados comprovam que medicamentos genéricos e similares de mesmo fármaco não são obrigatoriamente intercambiáveis e a substituição, principalmente para aqueles usados no tratamento de doenças crônicas, podem trazer graves consequências clínicas. Esta preocupação é aumentada para os fármacos com estreita faixa terapêutica e aqueles com alta variabilidade no processo de absorção. A adoção de uma lista de medicamentos não substituíveis, a exemplo de outros países, e o investimento na divulgação de informações sobre intercambialidade de medicamentos, tanto para profissionais de saúde como para a população, podem contribuir para a redução da substituição entre medicamentos não intercambiáveis, a promoção do uso racional dos medicamentos, a redução de gastos com medicamentos e tratamento de eventos adversos e o aumento da adesão do paciente ao tratamento. / The implementation of generic drugs in Brazil, as well as programs and policies to ensure access to medicines with quality, safety and efficacy to the overall population, resulted in more than 3,800 generic drug products of 445 drugs registered in the National Health Surveillance Agency (ANVISA) since 1999. Generic drug products proved their therapeutic equivalence in bioequivalence studies and, therefore, the interchangeability with their respective reference drug product. In 2014, ANVISA expanded the interchangeability to similar drug products, increasing the number of interchangeable drug products for each reference drug product. Regulations for the prescription and dispensation of medicine only allow the substitution of a reference drug product for a generic or an interchangeable similar drug product or vice versa. However, in practice, it appears that there is a substitution between generic and similar drug products of a same reference drug product in private pharmacy chains - where discounts reach up to 90% of the selling price - as well as in public pharmacy, depending on the medicine availability, because public purchases are based on the lower price offered by the manufacturers. Nevertheless, the bioequivalence and interchangeability between generic and similar drug products of the same reference drug product cannot be guaranteed because they haven\'t been evaluated. Lack of bioequivalence between substituted drug products may result in therapeutic ineffectiveness or the occurrence of adverse events and even to patient intoxication. As a consequence, there might be waste, expenses due to adverse events treatment, no adherence to the treatment or the adoption of second-line treatment. This study evaluated the bioequivalence between generic and similar drugs of the same reference drug product through a meta-analysis, using data from bioequivalence studies carried out for the registration of generic and similar drug products at ANVISA. The drugs included in the study were acyclovir, amoxicillin, cephalexin, doxazosin, phenytoin, fluoxetine, levofloxacin and quetiapine. Results showed lack of bioequivalence between most of the generic and similar drugs containing the same drug and prove that generic and similar drug products of the reference drug product are not necessarily interchangeable. Moreover, the substitution of drugs used for chronic illnesses could lead to serious clinical consequences. This concern increases for drugs with narrow therapeutic index and those with high variable absorption process. The adoption of a list of non-interchangeable medicines - like in other countries - and investment in the dissemination of information about interchangeability between drug products to health professionals and to the population may contribute to reduce the substitution of drugs which are not interchangeable, promote a rational use of medicines, the reduction of expenses with drugs and adverse effects treatment and to improve treatment adherence.
110

Reconnaissance de la parole pour l’aide à la communication pour les sourds et malentendants / Speech recognition as a communication aid for deaf and hearing impaired people

Orosanu, Luiza 11 December 2015 (has links)
Cette thèse fait partie du projet RAPSODIE dont l’objectif est de proposer une reconnaissance vocale spécialisée sur les besoins des personnes sourdes et malentendantes. Deux axes sont étudiées : la modélisation lexicale et l’extraction d’informations para-lexicales. Concernant la modélisation lexicale, nous avons étudié les modèles de langage hybrides combinant mots et syllabes, et nous avons proposé une nouvelle approche basée sur une notion de similarité entre mots pour l’ajout de nouveaux mots dans le modèle de langage. Concernant l’extraction d’informations para-lexicales, nous avons étudié l'utilisation des paramètres prosodiques, des paramètres linguistiques ou de leur combinaison pour la détection des questions et des affirmations. Cette détection a comme but de signaler aux personnes sourdes ou malentendantes quand une question leur est adressée / This thesis is part of the RAPSODIE project which aims at proposing a speech recognition device specialized on the needs of deaf and hearing impaired people. Two aspects are studied: optimizing the lexical models and extracting para-lexical information. Regarding the lexical modeling, we studied hybrid language models combining words and syllables, and we proposed a new approach based on a similarity measure between words to add new words in the language model. Regarding the extraction of para-lexical information, we investigated the use of prosodic features, of linguistic features and of their combination for the detection of questions and statements. This detection aims to inform the deaf and hearing impaired people when a question is addressed to them

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