Many software reliability growth models have beenanalyzed for measuring the growth of software reliability. In this dissertation, regression methods are explored to study software reliability models. First, two parametric linear models are proposed and analyzed, the simple linear regression and transformed linearregression corresponding to a power law process. Some software failure data sets do not follow the linear pattern. Analysis of popular real life data showed that these contain outliers andleverage values. Linear regression methods based on least squares are sensitive to outliers and leverage values. Even though the parametric regression methods give good results in terms of error measurement criteria, these results may not be accurate due to violation of the parametric assumptions. To overcome these difficulties, nonparametric regression methods based on ranks are proposed as alternative techniques to build software reliability models. In particular, monotone regre ssion and rank regression methods are used to evaluate the predictive capability of the models. These models are applied to real life data sets from various projects as well as to diverse simulated data sets. Both the monotone and the rank regression methods are robust procedures that are less sensitive to outliers and leverage values. In particular, the regression approach explains predictive properties of the mean time to failure for modeling the patterns of software failure times.In order to decide on model preference and to asses predictive accuracy of the mean time between failure time estimates for the defined data sets, the following error measurements evaluative criteria are used: the mean square error, mean absolute value difference, mean magnitude of relative error, mean magnitude oferror relative to the estimate, median of the absolute residuals, and a measure of dispersion. The methods proposed in this dissertation, when applied to real software failure data, give lesserror in terms of all the measurement criteria compared to other popular methods from literature. Experimental results show that theregression approach offers a very promising technique in software reliability growth modeling and prediction.

Orientador: Luiz Antonio Barreira San Martin, Marco Antonio Teixeira / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Matematica, Estatistica e Computação Científica / Made available in DSpace on 2018-08-05T23:39:22Z (GMT). No. of bitstreams: 1 Patrao_MauroMoraesAlves_D.pdf: 1206233 bytes, checksum: 5ea367b133840cc39b04e05a28c59d28 (MD5) Previous issue date: 2006 / Resumo: A presente tese fornece uma abordagem que estabelece conexões entre dinâmica e teoria de semigrupos. Esta abordagem, denominada de teoria de semigrupos de sombreamento, é aplicada com sucesso no estudo de semifluxos de endomorfismos de uma classe bastante ampla de fibrados, que inclui a classe dos fibrados projetivos. Os semifluxos de endomorfismos de um fibrado generalizam, por meio da linguagem geométrica de fibrados, os semifluxos de produto cruzado associados a um cociclo, definidos em fibrados triviais / Abstract: The present thesis provides an approach which establishes connections between dynamics and the theory of semigroup. This approach, named theory of shadowing semigroups, is successfully applied to study semiflows of endomorphisms of a wide class of fiber bundles, which includes the class of the projective bundles. The semiflows of endomorphisms of a fiber bundle generalize, by using the geometric concept of fiber bundle, the skew-product semiflows associated to a cocycle, which are defined in trivial bundles / Doutorado / Geometria e Topologia/Sistemas Dinamicos / Doutor em Matemática

The theories of the law of one price and purchasing power parity are thought to hold almost exactly in financial market, but it seems less likely to occur in international trade where arbitrage opportunities take place. The purpose of this study is to test whether the purchasing power parity holds for commodities in various national markets, for which a quantitative method is followed. For identical goods, the prices should be equal across countries. In fact, the prices vary significantly across ‘truly homogenous’ goods within a product group. The finding suggests that differences in productivity and value-added tax do have significant positive impacts on price settings. As a consequence, purchasing power parity definitely does not prevail as well as law of one price does not. Further studies can use these findings to examine the extent and permanence of violations of the law of one price.

This research work discusses the removal of organic pollutants specifically diclofenac and acid blue-25 using chalcogenide semiconductors. Semiconductors are materials that absorb light of specific energy and potentially degrade these organic pollutants into smaller compounds that are not toxic such as carbon dioxide and water. / Civil and Chemical Engineering

Les besoins énergétiques mondiaux sont principalement satisfaits par l’utilisation de ressources fossiles telles que le pétrole, le charbon ou le gaz. L’utilisation de ces ressources fossiles dans le domaine de l’énergie ou de l’industrie chimique entraine une forte accumulation de CO2 dans l’atmosphère et provoque des dérèglements climatiques. En plus de poser un problème écologique majeur, ces ressources fossiles ne sont pas renouvelables et poseront un problème de disponibilités à terme. Pour parer à ces difficultés, une solution envisageable est de limiter, voire de stopper l’utilisation des ressources fossiles au profit de sources carbonées renouvelables telles que le CO2 ou la biomasse. Ces ressources pourrait être utilisées comme source de produits chimiques et / ou pour le stockage des énergies intermittentes. Ces utilisations requièrent la transformation de composés oxygénés comportant des liaisons C=O (comme CO2) et C−O (comme la biomasse) et demandent un apport d’énergie dans des réactions de réduction. Peu de réducteurs sont compatibles avec cette utilisation qui nécessite l’emploi de composés à la fois renouvelables et ayant un potentiel rédox adapté à la réduction de liaisons C–O. Ce sont essentiellement le dihydrogène et l’acide formique. Dans ce contexte, le présent travail doctoral se propose de définir et de répondre au cahier des charges d’un réducteur renouvelable. En premier lieu, l’utilisation des formiates de silicium est explorée, à travers des réactions mimant le comportement d’hydrosilanes. Cette stratégie est mise à profit dans des réactions de couplages déshydrogénant et pour la réduction de cétones par hydrosilylation par transfert. Enfin, ce concept est transposé à l’hydroboration par transfert avec l’utilisation de composés mono formiates de bore et d’un catalyseur mettant en jeu un ligand participatif. Les formiates de bore et de silicium apparaissent ainsi comme des réducteurs renouvelables attrayants, qui combinent une source d’hydrure renouvelable (l’acide formique) avec un élément oxophile du groupe principal dont les propriétés stéréo-électroniques sont facilement modulables. / Global energy needs are mostly covered by the use of fossil fuels such as oil, coal or gas. The use of these fossil resources in the field of energy or the chemical industry causes a high accumulation of CO2 in the atmosphere and causes climatic disturbances. In addition to posing a major ecological problem, these fossil resources are not renewable and will pose a problem of availability in the long term. To overcome these difficulties, one possible solution is to limit or even stop the use of fossil resources in favor of renewable carbon sources such as CO2 or biomass. These resources could be used as a source of chemicals and / or storage of intermittent energies. These uses require the conversion of oxygenates with C=O (such as CO2) and C–O (such as biomass) and require energy input into reduction reactions. Few reducers are compatible with this use which requires the use of compounds both renewable and having a redox potential adapted to the reduction of C–O bonds. These are essentially dihydrogen and formic acid. In this context, this doctoral work aims to define and meet the specifications of a renewable reducer. In the first place, the use of silyl formates is explored, through reactions mimicking the behavior of hydrosilanes. This strategy is used in dehydrogenating coupling reactions and for the reduction of ketones by transfer hydrosilylation. Finally, this concept is transposed to transfer hydroboration with the use of boryl mono formate compounds and a catalyst involving a participative ligand. The boryl and silyl formates thus appear as attractive renewable reducers, which combine a source of renewable hydride (formic acid) with an oxophilic element of the main group whose stereo-electronic properties are easily adjustable.

This work deals with diffrential equations, with the possibility     of using them for analysis of the line and the possibility     of accelerating the computations in GPU using nVidia CUDA.

Philosophiae Doctor - PhD / The major objective of this study was to investigate the nature of the relationship between achievement motivation, autonomous and social achievement values, study habits and attitudes, locus of control and socio-economic status (SES) as independent variables on the one hand and the level of achievement as dependent variable on the other. The subjects were 548 second and third year social science students who were studying in seven different directions at the University of the Western Cape during 1990. The following measuring instruments were used in the investigation: The Ray-Lynn (1980) Achievement Orientation questionnaire; Strumpfer's (1975) questionnaire for the measuring of autonomous and social achievement values; Rotter's (1966) internal/external locus of control scale, as adapted by Collins (1974); The study habits and attitudes subscales of the Brown and Holtzman (1955) Survey of Study Habits and Attitudes (SSHA) questionnaire, as adapted for South African conditions; A brief biographical questionnaire The achievement criterion consisted of the average achievement point, which is constituted of a proportion of achievement obtained in continuous evaluation, and a proportion of achievement obtained in the final examination. The following findings were made: Achievement motivation plays a much smaller role in achievement than can be expected and its influence is gender specific. It explains only about 5% of the variance in the achievement of males, and non in the case of females. Academically successful and unsuccessful students could also not be distinguished from each other in terms of level of achievement motivation. The measuring instrument for achievement motivation, although valid and reliable, probably does not succeed in measuring aspects of achievement motivation which are related to a specific situation such as the academic. While social achievement value is not related to achievement, autonomous achievement value explains 4,8% of the variance in achievement of males but none in the case of females. Successful and unsuccessful students also do not differ from each other with regard to their achievement value orientation. Study habit and attitude do not differ in their ability to predict the achievement criterion and explain 4,1% and 5,3% of the variance in achievement of males respectively, but none in the case of females. Successful and unsuccessful students can be distinguished in terms of their study habits and attitudes. Socio-economic status has a differential influence on achievement. While higher SES females achieve at a higher level than low SES females, males do not differ in this regard. The subjects are predominantly internally orientated as far as locus of control characteristic is concerned. Although internal individuals display more "positive" characteristics compared to external individuals, the two groups do not, however, differ as far as level of achievement is concerned, irrespective of gender or socio-economic status. African students have a more positive attitude towards study compared to English and Afrikaans speaking, as well as bilingual (English and Afrikaans speaking) students. Females in this study are generally more homogenous than males. It is recommended that: The suitability of the average achievement point as a criterion of achievement be studied; A broad investigation be launched into practices and problems which might centre around the system of continuous evaluation at uwc, with specific reference to possible problems that students, lecturers and big departments may experience; The nature of differences which might exist between higher and low SES female, and low SES female and low SES male students be investigated; The nature of debilitating factors which affect the achievement of low SES female students be investigated; The tendency towards greater homogeneity among female influence thereof on university study; The adjustment of African students at uwc be studied with the objective of identifying factors that obstruct their academic progress

In this thesis, new algorithms for formation control of multi agent systems (MAS) based on continuum mechanics principles will be investigated. For this purpose agents of the MAS are treated as particles in a continuum, evolving in an n-D space, whose desired configuration is required to satisfy an admissible deformation function. Considered is a specific class of mappings that is called homogenous where the Jacobian of the mapping is only a function of time and is not spatially varying. The primary objectives of this thesis are to develop the necessary theory and its validation via simulation on a mobile-agent based swarm test bed that includes two primary tasks: 1) homogenous transformation of MAS and 2) deployment of a random distribution of agents on to a desired configuration. Developed will be a framework based on homogenous transformations for the evolution of a MAS in an n-D space (n=1, 2, and 3), under two scenarios: 1) no inter-agent communication (predefined motion plan); and 2) local inter-agent communication. Additionally, homogenous transformations based on communication protocols will be used to deploy an arbitrary distribution of a MAS on to a desired curve. Homogenous transformation with no communication: A homogenous transformation of a MAS, evolving in an space, under zero inter agent communication is first considered. Here the homogenous mapping, is characterized by an n x n Jacobian matrix ( ) and an n x 1 rigid body displacement vector ( ), that are based on positions of n+1 agents of the MAS, called leader agents. The designed Jacobian ( ) and rigid body displacement vector ( ) are passed onto rest of the agents of the MAS, called followers, who will then use that information to update their positions under a pre- iv defined motion plan. Consequently, the motion of MAS will evolve as a homogenous transformation of the initial configuration without explicit communication among agents. Homogenous Transformation under Local Communication: We develop a framework for homogenous transformation of MAS, evolving in , under a local inter agent communication topology. Here we assume that some agents are the leaders, that are transformed homogenously in an n-D space. In addition, every follower agent of the MAS communicates with some local agents to update its position, in order to grasp the homogenous mapping that is prescribed by the leader agents. We show that some distance ratios that are assigned based on initial formation, if preserved, lead to asymptotic convergence of the initial formation to a final formation under a homogenous mapping. Deployment of a Random Distribution on a Desired Manifold: Deployment of agents of a MAS, moving in a plane, on to a desired curve, is a task that is considered as an application of the proposed approach. In particular, a 2-D MAS evolution problem is considered as two 1-D MAS evolution problems, where x or y coordinates of the position of all agents are modeled as points confined to move on a straight line. Then, for every coordinate of MAS evolution, bulk motion is controlled by two agents considered leaders that move independently, with rest of the follower agents motions evolving through each follower agent communicating with two adjacent agents.

No description available.

Les amines, et plus généralement les dérivés organiques qui contiennent de l’azote, constituent la clef de voûte de bien des domaines de la chimie à haute valeur ajoutée. Ils ont toujours fait l’objet de nombreuses recherches dans différents domaines de la chimie organique et de la chimie fine telles que l’agrochimie et la pharmacie. Malgré tout, la synthèse de ces structures azotées constitue encore souvent défi important pour les équipes de recherche, qu’elles soient académiques ou industrielles. De nombreuses méthodes permettent la synthèse des amines dont la grande majorité est caractérisée par la présence d’un centre chiral en alpha ou en béta de l’atome d’azote. L’une des voies les plus largement explorées pour l’obtention des amines chirales depuis plus de cinquante ans demeure l’hydrogénation asymétrique de substrats azotés. Ce travail de recherche a été mené dans le cadre d’une collaboration avec la société HOLIS Technologies. Nous nous sommes concentrés sur la mise au point d’outils catalytiques de synthèse d’amines chirales primaires et plus précisément sur des systèmes homogènes mettant en œuvre des métaux de transition pour accéder à des réactions d’hydrogénation énantiosélective. Nous nous sommes intéressés à la synthèse de trois amines chirales cibles en chimie pharmaceutique, étayée par l’étude de molécules modèles analogues. Nous avons étudié l’hydrogénation de substrats prochiraux azotés de type oxime, imine ou énamine conduisant, en une ou deux étapes, à l’amine primaire chirale visée. Dans le premier chapitre, notre étude a porté sur la synthèse et la caractérisation fine de chacun des substrats et de leurs amines chirales correspondantes. La RMN 15N étudiée sur ces molécules a permis de constituer un outil d’analyse complémentaire dans l’élucidation de ces structures. Dans le deuxième chapitre nous nous sommes attachés à développer un outil de synthèse catalytique avec pour objectif l’hydrogénation asymétrique pour les molécules modèles comme pour les molécules complexes de chacun des trois projets. Le troisième chapitre est dédié à la compréhension fine du cycle catalytique que nous avons entamée grâce à des analyses RMN multinoyaux (essentiellement 103Rh et 31P) et à des calculs quantiques conduits sur les complexes cationiques du rhodium qui se sont révélés actifs. La synthèse globale de ces résultats nous amène à avoir la capacité de choisir le meilleur substrat (imine, énamine, oxime) et le système catalytique associé pour son hydrogénation, afin de répondre au besoin industriel précis de synthèse d’une amine primaire chirale donnée. / Amines, and more generally, nitrogen-containing compounds are key building blocks in the field of fine chemicals, especially agrochemistry and pharmaceuticals. Synthesis of these nitrogen-containing compounds still is a frequent challenge to academic as well as industrial research teams. Several methods are available for the synthesis of amines containing an alpha or beta chiral center and for more than fifty years, one of the most widely investigated methods is the asymmetric hydrogenation of unsaturated substrates. Our research in this field has lead to an industrial partnership with the HOLIS Technologies company. We focus on the development of catalytic tools in order to synthesize chiral primary amines and more precisely, homogeneous catalysis with transition metals to obtain enantioselective hydrogenation. We got involved with the synthesis of three primary chiral amines well known as key targets in the pharmaceutical industry, with the study of analogous models conducted in parallel. We have studied the hydrogenation of prochiral substrates such as enamines, imines, and oximes leading in one or two steps to the desired primary chiral amine. In the first chapter, synthesis and characterization of substrates and chiral amines are described. Use of 15N NMR on these nitrogen-containing molecules allows us to establish a complementary tool for the structure elucidation. The second chapter is dedicated to the optimization of a catalyst system for the asymmetric hydrogenation of these molecules. The third chapter contains the initial studies into the intricate details of the catalytic cycle with the use of multinuclear NMR analysis (especially 103Rh and 31P) and DFT calculations on rhodium cationic complexes. An overview of these results gives us insight into the choice of the best substrate (imine, enamine, oxime) and the optimal catalyst system for the hydrogenation with the goal of addressing the industrial need of a given chiral primary amine.