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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.
241

" Resolution Search " et problèmes d'optimisation discrète

Posta, Marius 03 February 2012 (has links) (PDF)
Les problèmes d'optimisation discrète sont pour beaucoup difficiles à résoudre, depar leur nature combinatoire. Citons par exemple les problèmes de programmationlinéaire en nombres entiers. Une approche couramment employée pour les résoudreexactement est l'approche de Séparation et Évaluation Progressive. Une approchedifférente appelée " Resolution Search " a été proposée par Chvátal en 1997 pourrésoudre exactement des problèmes d'optimisation à variables 0-1, mais elle restemal connue et n'a été que peu appliquée depuis.Cette thèse tente de remédier à cela, avec un succès partiel. Une première contributionconsiste en la généralisation de Resolution Search à tout problème d'optimisationdiscrète, tout en introduisant de nouveaux concepts et définitions. Ensuite,afin de confirmer l'intérêt de cette approche, nous avons essayé de l'appliquer enpratique pour résoudre efficacement des problèmes bien connus. Bien que notrerecherche n'ait pas abouti sur ce point, elle nous a amené à de nouvelles méthodespour résoudre exactement les problèmes d'affectation généralisée et de localisationsimple. Après avoir présenté ces méthodes, la thèse conclut avec un bilan et desperspectives sur l'application pratique de Resolution Search.
242

Sur l'estimation semi paramétrique robuste pour statistique fonctionnelle

Attaoui, Said 10 December 2012 (has links) (PDF)
Dans cette thèse, nous nous proposons d'étudier quelques paramètres fonctionnels lorsque les données sont générées à partir d'un modèle de régression à indice simple. Nous étudions deux paramètres fonctionnels. Dans un premier temps nous supposons que la variable explicative est à valeurs dans un espace de Hilbert (dimension infinie) et nous considérons l'estimation de la densité conditionnelle par la méthode de noyau. Nous traitons les propriétés asymptotiques de cet estimateur dans les deux cas indépendant et dépendant. Pour le cas où les observations sont indépendantes identiquement distribuées (i.i.d.), nous obtenons la convergence ponctuelle et uniforme presque complète avec vitesse de l'estimateur construit. Comme application nous discutons l'impact de ce résultat en prévision non paramétrique fonctionnelle à partir de l'estimation de mode conditionnelle. La dépendance est modélisée via la corrélation quasi-associée. Dans ce contexte nous établissons la convergence presque complète ainsi que la normalité asymptotique de l'estimateur à noyau de la densité condtionnelle convenablement normalisée. Nous donnons de manière explicite la variance asymptotique. Notons que toutes ces propriétés asymptotiques ont été obtenues sous des conditions standard et elles mettent en évidence le phénomène de concentration de la mesure de probabilité de la variable fonctionnelle sur des petites boules. Dans un second temps, nous supposons que la variable explicative est vectorielle et nous nous intéressons à un modèle de prévision assez général qui est la régression robuste. A partir d'observations quasi-associées, on construit un estimateur à noyau pour ce paramètre fonctionnel. Comme résultat asymptotique on établit la vitesse de convergence presque complète uniforme de l'estimateur construit. Nous insistons sur le fait que les deux modèles étudiés dans cette thèse pourraient être utilisés pour l'estimation de l'indice simple lorsque ce dernier est inconnu, en utilisant la méthode d'M-estimation ou la méthode de pseudo-maximum de vraisemblance, qui est un cas particulier de la première méthode.
243

Literatūros mokslo tekstų sakinių tipai (remiantis R. Brūzgienės, J. Sprindytės, A. Kalėdos tekstais) / The literature of science texts sentences types (based on R. Brūzgienė, J. Sprindytė, A. Kalėda texts)

Semionova, Tatjana 29 June 2009 (has links)
Darbo objektas - vientisiniai ir sudėtiniai sakiniai literatūrologų R. Brūzgienės, J. Sprindytės, A. Kalėdos tekstuose. Tyrimo objektas - tirti vientisinius ir sudėtinius sakinius bei jų tipologiją. / The work object - types of simple and composite sentences in R. Brūzgienė's, J. Sprindytė's, A. Kalėda's texts. The aim of research - investigate simple and composite sentences and their typology.
244

Naftos ir naftos ploviklio Simple Green bendras toksinis poveikis vaivorykštiniam upėtakiui ankstyvoje ontogenezėje / The toxic effects of crude oil combined with oil cleaner "simple green" on rainbow trout in ontogenesis

Ratkelytė, Eglė 08 September 2009 (has links)
NAFTOS IR NAFTOS PLOVIKLIO SIMPLE GREEN BENDRAS TOKSINIS POVEIKIS VAIVORYKŠTINIAM UPĖTAKIUI ANKSTYVOJE ONTOGENEZĖJE E. Ratkelytė Vilniaus universitetas Santrauka Tyrimai buvo atlikti su vaivorykštinio upėtakio (Oncorhynchus mykiss) ikrais (nuo „akutės“ stadijos) ir lervomis (nuo jų išsiritimo pradžios iki trynio maišelio rezorbcijos), veikiant juos 0,11, 0,22, 0,43, 0,87, 1,73, 3,46, 6,93 g/l naftos koncentracijomis į kiekvieną iš jų pridedant 0,5 g/l ploviklio Simple Green. Toksiškumo kriterijai buvo upėtakio ikrų ir lervų žuvimo procentas, ir tokie fiziologiniai rodikliai, kaip širdies (ŠD) bei kvėpavimo (KD) dažniai. Darbo tikslas buvo ištirti naftos ir naftos ploviklio Simple Green bendrą toksinį poveikį vaivorykštiniam upėtakiui (Oncorhynchus mykiss) ankstyvose jo vystymosi stadijose priklausomai nuo koncentracijos ir poveikio trukmės bei įvertinti ilgalaikio poveikio fiziologiniams rodikliams ypatumus. Apibendrinus gautus rezultatus galima teigti, kad vaivorykštinio upėtakio jautrumas naftos ir ploviklio Simple Green mišiniui priklauso nuo mišiniu veikiamos individo vystymosi stadijos, poveikio trukmės, ir naftos bei ploviklio koncentracijų santykio mišinyje. Nustatyta, kad jautriausios naftos poveikiui pasirodė lervutės ritimosi metu, mažiau jautrūs pasirodė embrionai ankstyvoje „akutės“ stadijoje. Palyginus gautus rezultatus su rezultatais gautais tiriant vien tik naftos poveikį vaivorykštiniam upėtakiui ankstyvoje ontogenezėje, matome, kad ploviklis Simple Green... [toliau žr. visą tekstą] / THE TOXIC EFFECT OF CRUDE OIL COMBINED WITH OIL CLEANER „SIMPLE GREEN“ ON RAINBOW TROUT IN EARLY ONTOGENESIS E. Ratkelytė Vilnius University Summary Long-term effects of crude oil combined with oil cleaner „Simple Green“ were evaluated in chronic toxicity tests by use of rainbow trout (Oncorhynchus mykiss) in early stages of development (embryos, larvae) as test-objects. The following toxicity criteria were studied for evaluation of toxic effects: mortality of embryos and larvae; physiological parameters (heart rate, ventilation frequency). The aim of the study was to investigate the overall effect of crude oil combined with oil cleaner „Simple Green“ on rainbow trout (Oncorhynchus mykiss) in early development stages (embryos, larvae) depending on oil concentration in the mixture and exposure duration and to evaluate the specificity of negative effects of mixture on physiological parameters of fish. It was determined that 0.87, 1.73, 3.46 and 6.93 g/l concentrations of crude oil combined with 0.5 g/l of “Simple Green” resulted in the significant increase in larvae mortality, but practically had no negative effect on embryos. Hatching was found to be the most sensitive stage of development, 1 day age larvae were less and embryos were the least sensitive to the toxic impact of mixture, respectively. It was estimated that 0.87+0.5, 1.73+0.5, 3.46+0.5 and 6.93+0.5 g/l concentrations of crude oil combined with oil cleaner „Simple Green“ disturbed the work of cardiorespiratory... [to full text]
245

Fischer Clifford matrices and character tables of certain groups associated with simple groups O+10(2) [the simple orthogonal group of dimension 10 over GF (2)], HS and Ly.

Seretlo, Thekiso Trevor. January 2011 (has links)
The character table of any finite group provides a considerable amount of information about a group and the use of character tables is of great importance in Mathematics and Physical Sciences. Most of the maximal subgroups of finite simple groups and their automorphisms are extensions of elementary abelian groups. Various techniques have been used to compute character tables, however Bernd Fischer came up with the most powerful and informative technique of calculating character tables of group extensions. This method is known as the Fischer-Clifford Theory and uses Fischer-Clifford matrices, as one of the tools, to compute character tables. This is derived from the Clifford theory. Here G is an extension of a group N by a finite group G, that is G = N.G. We then construct a non-singular matrix for each conjugacy class of G/N =G. These matrices, together with partial character tables of certain subgroups of G, known as the inertia groups, are used to compute the full character table of G. In this dissertation, we discuss Fischer-Clifford theory and apply it to both split and non-split extensions. We first, under the guidance of Dr Mpono, studied the group 27:S8 as a maximal subgroup of 27:SP(6,2), to familiarize ourselves to Fischer-Clifford theory. We then looked at 26:A8 and 28:O+8 (2) as maximal subgroups of 28:O+8 (2) and O+10(2) respectively and these were both split extensions. Split extensions have also been discussed quite extensively, for various groups, by different researchers in the past. We then turned our attention to non-split extensions. We started with 24.S6 and 25.S6 which were maximal subgroups of HS and HS:2 respectively. Except for some negative signs in the first column of the Fischer-Clifford matrices we used the Fisher-Clifford theory as it is. The Fischer-Clifford theory, is also applied to 53.L(3, 5), which is a maximal subgroup of the Lyon's group Ly. To be able to use the Fisher-Clifford theory we had to consider projective representations and characters of inertia factor groups. This is not a simple method and quite some smart computations were needed but we were able to determine the character table of 53.L(3,5). All character tables computed in this dissertation will be sent to GAP for incorporation. / Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2011.
246

Use of random amplified microsatellites (RAMS) to discern genotypes of Saprolegnia parasitica isolates on the west coast of British Columbia

Naumann, Cayla 05 May 2014 (has links)
Several oomycete species of the genus Saprolegnia are recognized as devastating fish pathogens and are responsible for the loss of millions of fish annually for the aquaculture industry. Until recently, these pathogens were kept in check using malachite green; however, due to its toxicity, this chemical has now been banned from use. Saprolegnia parasitica is recognized as the major pathogen of aquaculture fish species. The industry is struggling to predict and control S. parasitica outbreaks in fish hatcheries and there is a need for new knowledge regarding the population genetic structure of this pathogen. Random amplified microsatellites were used to compare isolates of S. parasitica collected from a variety of hatchery locations during the period of November 2009 - August 2011, in order to determine the level of genetic variability and determine changes in genetic diversity over time. Allele frequencies of scored characters were graphically compared. Population genetic diversity was measured using Nei’s genetic distance, Shannon’s Information Index, number of polymorphic loci and phylogenetic trees. Due to the presence of Saprolegnia parasitica in the facilities tested, it appears to be ubiquitous in aquaculture facilities and treatment and prevention will be an ongoing concern in aquaculture management. Overall, genetic diversity of S. parasitica isolates was determined to be low with at least some sexual recombination occurring over time. There was a diversity of genotypes collected from the same hatchery on a single day, indicating there was not a single genotype present at a given time point. Genetic profiling, such as used here, could provide facility managers with a new approach to develop a series of best practices to control sporadic outbreaks of disease. Use of these genetic markers and close monitoring of S. parasitica genotypes will permit early detection and sanitation protocols. / Graduate / 2015-04-24 / 0476 / 0792 / 0369 / cren06@uvic.ca
247

Física (MA64): Guía de laboratorio, ciclo 2014-2

Bautista, Gabriel, Castañeda, Oscar, De la Flor, Jorge, Macedo, Anthony 24 July 2014 (has links)
El desarrollo de las habilidades experimentales de un estudiante de Arquitectura es una parte importante de su formación. Un profesional en arqui tectura debe saber medir, usar correctamente las unidades, realizar apreciaciones y generar conclusiones sobre ocurrencias reales, redactar adecuada y correctamente un inform e, etc. Estas habilidades habrán de ser adquiridas y afianzadas durante el desarrollo de su s cursos formativos dentro de la Universidad Peruana de Ciencias Aplicadas. Dado que la Física es esencialmente experimental, e s evidente que será precisa para el aprendizaje y desarrollo de tales características. Por esta razón es que consideramos necesaria la realización de esta guía de laboratorio en que s e da un especial tratamiento de la parte experimental de la Física, contando con el debido s ustento teórico de los experimentos escogidos, de modo tal que los estudiantes desarrol len de una manera organizada y consciente, las pocas, pero sustanciales, experienc ias de laboratorio abordadas, y lleguen así a hacer suyos los conceptos que les serán de gran uti lidad no sólo en el afianzamiento de sus conocimientos del curso de Física, sino también en su futura actividad profesional.
248

Genetic analysis of Brassica carinata

2013 September 1900 (has links)
Brassica carinata is being actively pursued as a new industrial oil crop platform for the Canadian Prairies. A genetic assessment of B. carinata was performed to elucidate its evolutionary origins and create a genetic map to assist in locating genes and traits of interest that would help in marker-assisted breeding. First, genetic analysis using simple sequence repeat (SSR) markers, previously tested on B. juncea and B. napus, was performed, to examine the genetic diversity of 37 B. carinata lines. SSR analysis revealed world accessions were more diverse than lines conditioned to grow in the prairies. Diversity analysis revealed that the parental lines of a double haploid (DH) population, 179 and 345, obtained from the John Innes Centre (JIC), were among the more genetically diverse lines, supporting the use of this population for linkage mapping. Genetic markers created from 3’ targeted SNP discovery between 179 and 345, were tested on the DH population resulting in the generation of a B. carinata genetic linkage map essentially with no prior sequence data knowledge. This genetic map contained 341 SNP and 86 SSR loci identifying eight linkage groups belonging to the B genome, nine belonging to the C genome and two unidentified groups spanning 2041 cM. Comparative mapping of polymorphic markers identified in the amphidiploid B. carinata indicated the orientation of B and C genomes coincide with that of other Brassica species, and the two genomes have remained essentially unaltered, with no major chromosomal rearrangements since the formation of B. carinata. A lesser number of polymorphic markers were detected in the C genome, which suggested the B genome is more genetically diverse in B. carinata. Limited field trials of the 179 x 345 DH population were performed during the 2011 and 2012 growing seasons. Preliminary quantitative trait loci (QTLs) for agronomic traits including flowering time (FT), plant height (PH), and seed quality were identified.
249

Searching for Simple Symmetric Venn Diagrams

Ahmadi Mamakani, Abdolkhalegh 24 July 2013 (has links)
An n-Venn diagram is defined as a collection of n finitely intersecting closed curves dividing the plane into 2^n distinct regions, where each region is in the interior of a unique subset of the curves. A Venn diagram is simple if at most two curves intersect at any point, and it is monotone if it has some embedding on the plane in which all curves are convex. An n-Venn diagram has n-fold rotational symmetry if a rotation of 180 degrees about a centre point in the plane leaves the diagram unchanged, up to a relabeling of the curves. It has been known that rotationally symmetric Venn diagrams could exist only if the number of curves is prime. Moreover, non-simple Venn diagrams with rotational symmetry have been proven to exist for any prime number of curves. However, the largest prime for which a simple rotationally symmetric Venn diagram was known prior to this, was 7. In this thesis, we are concerned with generating simple monotone Venn diagrams, especially those that have some type(s) of symmetry. Several representations of these diagrams are introduced and different backtracking search algorithms are provided based on these representations. Using these algorithms we show that there are 39,020 non-isomorphic simple monotone 6-Venn diagrams in total. In the case of drawing Venn diagrams on a sphere, we prove that there exists a simple symmetric n-Venn diagram, for any n >= 6, with the following set(s) of isometries : (a) a 4-fold rotational symmetry about the polar axis, together with an additional involutional symmetry about an axis through the equator, or (b) an involutional symmetry about the polar axis together with two reflectional symmetries about orthogonal planes that intersect at the polar axis. Finally, we introduce a new type of symmetry of Venn diagrams which leads us to the discovery of the first simple rotationally symmetric Venn diagrams of 11 and 13 curves. / Graduate / 0984 / Khalegh@GMail.com
250

Dynamics of Holomorphic Maps: Resurgence of Fatou coordinates, and Poly-time Computability of Julia Sets

Dudko, Artem 11 December 2012 (has links)
The present thesis is dedicated to two topics in Dynamics of Holomorphic maps. The first topic is dynamics of simple parabolic germs at the origin. The second topic is Polynomial-time Computability of Julia sets.\\ Dynamics of simple parabolic germs. Let $F$ be a germ with a simple parabolic fixed point at the origin: $F(w)=w+w^2+O(w^3).$ It is convenient to apply the change of coordinates $z=-1/w$ and consider the germ at infinity $$f(z)=-1/F(-1/z)=z+1+O(z^{-1}).$$ The dynamics of a germ $f$ can be described using Fatou coordinates. Fatou coordinates are analytic solutions of the equation $\phi(f(z))=\phi(z)+1.$ This equation has a formal solution \[\tilde\phi(z)=\text{const}+z+A\log z+\sum_{j=1}^\infty b_jz^{-j},\] where $\sum b_jz^{-j}$ is a divergent power series. Using \'Ecalle's Resurgence Theory we show that $\tilde$ can be interpreted as the asymptotic expansion of the Fatou coordinates at infinity. Moreover, the Fatou coordinates can be obtained from $\tilde \phi$ using Borel-Laplace summation. J.~\'Ecalle and S.~Voronin independently constructed a complete set of invariants of analytic conjugacy classes of germs with a parabolic fixed point. We give a new proof of validity of \'Ecalle's construction. \\ Computability of Julia sets. Informally, a compact subset of the complex plane is called \emph if it can be visualized on a computer screen with an arbitrarily high precision. One of the natural open questions of computational complexity of Julia sets is how large is the class of rational functions (in a sense of Lebesgue measure on the parameter space) whose Julia set can be computed in a polynomial time. The main result of Chapter II is the following: Theorem. Let $f$ be a rational function of degree $d\ge 2$. Assume that for each critical point $c\in J_f$ the $\omega$-limit set $\omega(c)$ does not contain either a critical point or a parabolic periodic point of $f$. Then the Julia set $J_f$ is computable in a polynomial time.

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