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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.
1

Mezigenerační komunikace v managementu / Intergenerational communication in management (companies operating in the Czech Republic)

Biskup, Vojtěch January 2012 (has links)
Master's Thesis describes topic of intergenerational communication, which is important part of society. It's goal is to suggest an effective communication strategy on workplace for managers. Each country perceives age differently; therefore the thesis is in general focused on Czech corporate environment. The theoretical part defines the concept of communication, internal communication of companies and communication styles of key generations of the late 20th century. The practical part includes questionnaire form with both open and closed questions and survey took place in selected organizations, operating in the Czech Republic.
2

The Study of Phase Transition of The Torsion X-Y Model

Huang, Wen-Kuei 27 January 2003 (has links)
The phase transitions of a newly proposed torsion X-Y model, are studied with molecular dynamics. ForJ3 >0, the influence from J1 term is similar to the term.We found the Torsion X-Y Model and X-Y Model or Coupled X-Y Model all have the Kosterlitz-Thouless transition. (KT) We also confirm that the KT transition is a second order transition , The distribution of angle £c start from dis-ordered to well-ordered. KT starts first before the randomly distributed £c shows preference and ends when the preference is merged. For the J3 <0 case, the KT is also found in J3=-0.0167 and J3=-0.0334 The temperature for negative J3 is lower then that for positive J3 due to the resistant force to £c ordering from the coupled interaction.
3

Controlador neural aplicado a um sistema posicionador acionado por motores de indução trifásicos / Neural controller applied to a positioner system drived by tree-phase induction motors

Nóbrega Sobrinho, Carlos Alberto 24 February 2011 (has links)
Made available in DSpace on 2015-05-08T15:00:06Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 1366150 bytes, checksum: 91eeeb49bf7b5f1a1e12de73985e1fa1 (MD5) Previous issue date: 2011-02-24 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / This work presents the design of neural controllers for a X-Y table with two degrees of freedom. Both bases of the table moves horizontally, powered by tree-phases induction motors operated by frequency inverters. For detection position of bases, optical encoders were engaged to the axes of the engines to be obtained the angular displacement. A data acquisition board made the interface between a 2.4 GHz Core2Duo computer and the system. This board catches signals from the encoders and provides control signals to the frequency inverters. Neural controllers implemented in LabVIEW® software, determinate the control variables to power the engines. Step, sine and cosine reference were used to evaluate the system performance, in position control and following trajectory. Experimental results are presented. / No presente trabalho apresenta-se um projeto de controladores neurais para uma mesa de coordenadas X-Y com dois graus de liberdade. Ambas as bases que compõem a mesa se deslocam horizontalmente, sendo acionadas por motores de indução trifásicos alimentados através de inversores de freqüência. Para a detecção de posição das bases, encoders ópticos foram acoplados aos eixos dos motores, a fim de serem obtidos os deslocamentos angulares desses últimos. Uma placa de aquisição de dados realizou a interface entre um computador Core2Duo 2,4 GHz e a planta, para captar os sinais provenientes dos encoders e fornecer os sinais de controle aos inversores de frequência. No ambiente de programação LabVIEW®, implementaram-se os controladores neurais, os quais determinam as variáveis de controle que acionam os motores. Sinais de referência do tipo degrau e acompanhamento de trajetória foram utilizados para a avaliação do desempenho do sistema. Resultados experimentais são apresentados.
4

Ideální zákaznická zkušenosti napříč generacemi / Ideal Customer Experience across generation

Frolíková, Štěpánka January 2019 (has links)
The thesis deals with differences in perception of customer experience between generations X, Y and Z. It focuses on how the representatives of generations represent the ideal course of the customer journey and how their expectations conflict with reality. The theoretical part summarizes the knowledge of generation issues and customer experience. The work deals with methods of measuring customer experience. The empirical part examines how customer experience changes based on the concept of X, Y and Z generations. The aim of this thesis is to show the differences between generations using in-depth interviews and mystery shopping. Research shows that generational differences in customer experience are not significant. However, the relationship with the bank as a financial institution manifests itself as different depending on the life stage of human life. Key words Ideal customer experience, generation, concept of generation X, Y, and Z, customer experience, in-depth interviews, mystery shopping
5

Interações nemáticas competitivas no modelo XY generalizado em duas e três dimensões / Competing nematic interactions in the XY model in two and three dimensions

Canova, Gabriel Antônio January 2017 (has links)
Embora em um sistema bidimensional com simetria contínua não haja ordem de longo alcance para temperaturas finitas, o modelo XY 2D exibe uma transição de fase de ordem infinita não usual, associada com a dissociação de defeitos topológicos chamados de vórtices-inteiros, e que pertence à classe de universalidade de Kosterlitz-Thouless (KT). O modelo XY tridimensional exibe ordem de longo-alcance para baixas temperaturas e, à medida que a temperatura aumenta, passa para o estado desordenado através de uma transição ferromagnética usual. Generalizações do modelo XY, incluindo competição entre um termo ferromagnético e um nemático, foram introduzidas e estudadas por diversos autores. Essas interações nemáticas criam novas transições de fases e novos defeitos topológicos, como vórtices semi-inteiros. Neste trabalho, para casos particulares desses modelos generalizados, exploramos as classes de universalidade e os diagramas de fases em duas e três dimensões através de simulações de Monte Carlo usando algoritmos de cluster em GPUs, escalonamento de tamanhos finitos e análise da helicidade. Em particular, encontramos que a competição entre os termos ferromagnético e nemático dá origem a novas linhas de transição que podem pertencer a uma ampla gama de classes, desde a Kosterlitz-Thouless, 3dXY, Ising, Potts com 3 estados e até mesmo uma transição descontínua. / Although in a two-dimensional system with continuous symmetry there is no long-range order at finite temperature, the 2D XY model exhibits an unusual infinite order phase transition, associated with the unbinding of topological defects called integer-vortices, which belongs to the Kosterlitz-Thouless (KT) universality class. The three dimensional XY model exhibits a ferromagnetic long-range order at low temperatures and goes to the disordered state through a usual ferromagnetic transition. Generalizations of the XY model, including competition between a ferromagnetic and a nematic-like term, have been introduced and studied by many autors. These nematic-like interactions create new phase transitions and new topologial defects, like half-integer-vortices. In this work, for particular cases of these generalized models, we explore the universality classes of the transitions and the phase diagrams in two and three dimensions through Monte Carlo simulations using clusters algorithms on GPUs, finite size scaling and helicity analysis. In particular, we find that the competition between the ferromagnetic and nematic terms gives origin to new transition lines that can belong to a wide spectrum of classes, ranging from Kosterlitz-Thouless, 3dXY, Ising, 3 states Potts and even a discontinuous transition.
6

Contributions à la recherche dans des ensembles ordonnés : du séquentiel au parallèle

Galvao Ferreira, Afonso 17 January 1990 (has links) (PDF)
Le problème de la recherche d'un élément dans un ensemble donne est un des problèmes fondamentaux en informatique non numérique, lie, par exemple, aux bases de données, a la compilation, a l'optimisation combinatoire, etc... Dans cette thèse nous abordons le problème de la recherche dans des ensembles ordonnes et quelques problèmes qui lui sont lies. Une matrice est dite triée si elle possédé une relation d'ordre total sur chaque ligne et chaque colonne. Un cas particulier est l'ensemble des matrices définies par x+y, la somme cartésienne de deux vecteurs tries. Après un tour d'horizon des problèmes de la sélection, de la recherche et du tri sur des ensembles de la forme x=y, nous démontrons des bornes inférieures et introduisons des bornes supérieures pour les problèmes de la recherche et de la sélection. Nous proposons, en outre, plusieurs algorithmes parallèles pour la recherche dans x+y. Ensuite nous montrons comment appliquer ces résultats a la resolution en parallèle du problème de décision du sac-a-dos, ou, étant donnes plusieurs objets et un sac de capacité définie a remplir, on veut décider s'il existe une combinaison des objets qui remplit exactement le sac. Des algorithmes avec une accélération optimale sont introduits pour divers modèles de machines parallèles a mémoire partagée et distribuée. Pour ce problème les approches existantes se ramènent soit a la recherche dans x+y, soit a la traversée d'un espace combinatoire a l'aide de la technique du Branch & Bound. Cette dernière technique est aussi discutée dans ce travail, ou nous présentons un algorithme de Branch & Bound en vue de la resolution de problèmes d'optimisation combinatoire sur la connexion machine. Enfin, toujours dans le domaine de l'optimisation combinatoire, nous étudions le comportement de l'algorithme de recuit simule. Nous prouvons que, malgré la confiance qu'il inspire et sa grande utilisation pour des application
7

Sub-cubic Time Algorithm for the k-disjoint Maximum subarray Problem

Lee, Sang Myung (Chris) January 2011 (has links)
The maximum subarray problem is to find the array portion that maximizes the sum of array elements in it. This problem was first introduced by Grenander and brought to computer science by Bentley in 1984. This problem has been branched out into other problems based on their characteristics. k-overlapping maximum subarray problem where the overlapping solutions are allowed, and k-disjoint maximum subarray problem where all the solutions are disjoint from each other are those. For k-overlapping maximum subarray problems, significant improvement have been made since the problem was first introduced. For k-disjoint maximum subarrsy, Ruzzo and Tompa gave an O(n) time solution for one-dimension. This solution is, however, difficult to extend to two-dimensions. While a trivial solution of O(kn^3) time is easily obtainable for two-dimensions, little study has been undertaken to better this. This paper introduces a faster algorithm for the k-disjoint maximum sub-array problem under the conventional RAM model, based on distance matrix multiplication. Also, DMM reuse technique is introduced for the maximum subarray problem based on recursion for space optimization.
8

Interações nemáticas competitivas no modelo XY generalizado em duas e três dimensões / Competing nematic interactions in the XY model in two and three dimensions

Canova, Gabriel Antônio January 2017 (has links)
Embora em um sistema bidimensional com simetria contínua não haja ordem de longo alcance para temperaturas finitas, o modelo XY 2D exibe uma transição de fase de ordem infinita não usual, associada com a dissociação de defeitos topológicos chamados de vórtices-inteiros, e que pertence à classe de universalidade de Kosterlitz-Thouless (KT). O modelo XY tridimensional exibe ordem de longo-alcance para baixas temperaturas e, à medida que a temperatura aumenta, passa para o estado desordenado através de uma transição ferromagnética usual. Generalizações do modelo XY, incluindo competição entre um termo ferromagnético e um nemático, foram introduzidas e estudadas por diversos autores. Essas interações nemáticas criam novas transições de fases e novos defeitos topológicos, como vórtices semi-inteiros. Neste trabalho, para casos particulares desses modelos generalizados, exploramos as classes de universalidade e os diagramas de fases em duas e três dimensões através de simulações de Monte Carlo usando algoritmos de cluster em GPUs, escalonamento de tamanhos finitos e análise da helicidade. Em particular, encontramos que a competição entre os termos ferromagnético e nemático dá origem a novas linhas de transição que podem pertencer a uma ampla gama de classes, desde a Kosterlitz-Thouless, 3dXY, Ising, Potts com 3 estados e até mesmo uma transição descontínua. / Although in a two-dimensional system with continuous symmetry there is no long-range order at finite temperature, the 2D XY model exhibits an unusual infinite order phase transition, associated with the unbinding of topological defects called integer-vortices, which belongs to the Kosterlitz-Thouless (KT) universality class. The three dimensional XY model exhibits a ferromagnetic long-range order at low temperatures and goes to the disordered state through a usual ferromagnetic transition. Generalizations of the XY model, including competition between a ferromagnetic and a nematic-like term, have been introduced and studied by many autors. These nematic-like interactions create new phase transitions and new topologial defects, like half-integer-vortices. In this work, for particular cases of these generalized models, we explore the universality classes of the transitions and the phase diagrams in two and three dimensions through Monte Carlo simulations using clusters algorithms on GPUs, finite size scaling and helicity analysis. In particular, we find that the competition between the ferromagnetic and nematic terms gives origin to new transition lines that can belong to a wide spectrum of classes, ranging from Kosterlitz-Thouless, 3dXY, Ising, 3 states Potts and even a discontinuous transition.
9

Communication Reducing Approaches and Shared-Memory Optimizations for the Hierarchical Fast Multipole Method on Distributed and Many-core Systems

Abduljabbar, Mustafa 06 December 2018 (has links)
We present algorithms and implementations that overcome obstacles in the migration of the Fast Multipole Method (FMM), one of the most important algorithms in computational science and engineering, to exascale computing. Emerging architectural approaches to exascale computing are all characterized by data movement rates that are slow relative to the demand of aggregate floating point capability, resulting in performance that is bandwidth limited. Practical parallel applications of FMM are impeded in their scaling by irregularity of domains and dominance of collective tree communication, which is known not to scale well. We introduce novel ideas that improve partitioning of the N-body problem with boundary distribution through a sampling-based mechanism that hybridizes two well-known partitioning techniques, Hashed Octree (HOT) and Orthogonal Recursive Bisection (ORB). To reduce communication cost, we employ two methodologies. First, we directly utilize features available in parallel runtime systems to enable asynchronous computing and overlap it with communication. Second, we present Hierarchical Sparse Data Exchange (HSDX), a new all-to-all algorithm that inherently relieves communication by relaying sparse data in a few steps of neighbor exchanges. HSDX exhibits superior scalability and improves relative performance compared to the default MPI alltoall and other relevant literature implementations. We test this algorithm alongside others on a Cray XC40 tightly coupled with the Aries network and on Intel Many Integrated Core Architecture (MIC) represented by Intel Knights Corner (KNC) and Intel Knights Landing (KNL) as modern shared-memory CPU environments. Tests include comparisons of thoroughly tuned handwritten versus auto-vectorization of FMM Particle-to-Particle (P2P) and Multipole-to-Local (M2L) kernels. Scalability of task-based parallelism is assessed with FMM’s tree traversal kernel using different threading libraries. The MIC tests show large performance gains after adopting the prescribed techniques, which are inevitable in a world that is moving towards many-core parallelism.
10

Interações nemáticas competitivas no modelo XY generalizado em duas e três dimensões / Competing nematic interactions in the XY model in two and three dimensions

Canova, Gabriel Antônio January 2017 (has links)
Embora em um sistema bidimensional com simetria contínua não haja ordem de longo alcance para temperaturas finitas, o modelo XY 2D exibe uma transição de fase de ordem infinita não usual, associada com a dissociação de defeitos topológicos chamados de vórtices-inteiros, e que pertence à classe de universalidade de Kosterlitz-Thouless (KT). O modelo XY tridimensional exibe ordem de longo-alcance para baixas temperaturas e, à medida que a temperatura aumenta, passa para o estado desordenado através de uma transição ferromagnética usual. Generalizações do modelo XY, incluindo competição entre um termo ferromagnético e um nemático, foram introduzidas e estudadas por diversos autores. Essas interações nemáticas criam novas transições de fases e novos defeitos topológicos, como vórtices semi-inteiros. Neste trabalho, para casos particulares desses modelos generalizados, exploramos as classes de universalidade e os diagramas de fases em duas e três dimensões através de simulações de Monte Carlo usando algoritmos de cluster em GPUs, escalonamento de tamanhos finitos e análise da helicidade. Em particular, encontramos que a competição entre os termos ferromagnético e nemático dá origem a novas linhas de transição que podem pertencer a uma ampla gama de classes, desde a Kosterlitz-Thouless, 3dXY, Ising, Potts com 3 estados e até mesmo uma transição descontínua. / Although in a two-dimensional system with continuous symmetry there is no long-range order at finite temperature, the 2D XY model exhibits an unusual infinite order phase transition, associated with the unbinding of topological defects called integer-vortices, which belongs to the Kosterlitz-Thouless (KT) universality class. The three dimensional XY model exhibits a ferromagnetic long-range order at low temperatures and goes to the disordered state through a usual ferromagnetic transition. Generalizations of the XY model, including competition between a ferromagnetic and a nematic-like term, have been introduced and studied by many autors. These nematic-like interactions create new phase transitions and new topologial defects, like half-integer-vortices. In this work, for particular cases of these generalized models, we explore the universality classes of the transitions and the phase diagrams in two and three dimensions through Monte Carlo simulations using clusters algorithms on GPUs, finite size scaling and helicity analysis. In particular, we find that the competition between the ferromagnetic and nematic terms gives origin to new transition lines that can belong to a wide spectrum of classes, ranging from Kosterlitz-Thouless, 3dXY, Ising, 3 states Potts and even a discontinuous transition.

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