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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.
211

Constantes de acoplamento de vértices com mésons estranhos e charmosos usando as regras de soma da QCD / Coupling constants of vertices with strange and charming mesons using the QCD sum rules

Bruno Osório Rodrigues 12 March 2014 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Neste trabalho, foram calculados os fatores de forma e as constantes de acoplamento dos vértices mesônicos J/ψ DsDs, J/ψ Ds*Ds e J/ψ Ds*Ds*usando a técnica das regras de soma da QCD (RSQCD) até a ordem 5 da OPE. Estes três vértices estão envolvidos em algumas das numerosas hipóteses que tentam explicar a estrutura interna de alguns mésons charmosos exóticos que começaram a ser observados a partir de 2003. Tais mésons não se encaixam no espectro do charmonium e/ou apresentam números quânticos exóticos dentro do modelo CQM (constituent quark model). Um exemplo é o méson Y(4140), cujo decaimento observado é no par J/ψφ enquanto o esperado seria que tivesse decaimento predominante em mésons com open charm, devido à sua massa. Uma das propostas para se entender este méson consiste em estudá-lo como um estado molecular Ds*ar{D}s*, de modo que seu decaimento seria Y(4140) → Ds* ar{D}s* → J/ψφ. Neste processo, aparecerão os vértices de interação estudados neste trabalho, de maneira que o conhecimento mais preciso de seus fatores de forma e de suas constantes de acoplamento pode beneficiar a compreensão sobre a constituição fundamental do Y(4140) assim como a de outros novos estados como o X(4350), Y(4274) e Y(4660) por exemplo. Foram considerados neste trabalho, todos os casos off-shell possíveis para cada um dos três vértices, obtendo assim dois fatores de forma distintos para o vértice J/ψ DsDs, três para o vértice J/ψ Ds*Ds e dois para o vértice J/ψ Ds* Ds*. Nestes três vértices, os fatores de forma para o caso J/ψ off-shell foram bem ajustados por curvas monopolares enquanto os casos Ds e Ds* foram ajustados por curvas exponenciais, o que está de acordo com o comportamento encontrado em trabalhos anteriores do grupo. Os cálculos das constantes de acoplamento tiveram como resultados: g_{J/ψ Ds Ds} = 5.98^{+0.67}_{ -0.58}, g_{J/ψ D*s Ds} = 4.30_{+0.41}^{-0.35}GeV^{-1} e g_{J/ψ Ds* Ds*} = 7.47^{+1.04}_{-0.71}, resultados estes que estão compatíveis com os trabalhos anteriores que utilizaram as RSQCD para o cálculo das constantes de acoplamento dos vértices J/ψ D(*)D(*). / In this work, the form factors and coupling constants of the meson vertices J/ψ DsDs, J/ψ Ds*Ds and J/ψ Ds*Ds* have been calculated with the QCD sum rule (QCDSR) technique up to dimension 5 of the operator product expansion (OPE). These three vertices are involved in some of the numerous hypotheses that attempt to explain the internal structure of some exotic charmed mesons which began to be observed since 2003. Such mesons do not fit in the charmonium spectrum and/or have exotic quantum numbers within the CQM (constituent quark model). An example is the Y(4140) meson, which decays in the pair J/ψφ while the expected would be a dominant decay in open charm mesons. One of the proposals to understand this meson is to study it as a molecular state Ds*{D}s*, so it would decay as Y(4140)→ Ds* {D}s* → J/ψφ.In this process, the vertices studied in this work will appear, so the more accurate knowledge of their form factors and their coupling constants can benefit our understanding of the fundamental constitution of the Y(4140) as well as other new states as the X(4350), Y(4274) and Y (4660) eg. In this study all possible off-shell cases for each of these three vertices were considered, thus obtaining two different form factors for the vertex J/ψ DsDs, three for the vertex J/ψ Ds*Ds and two for the vertex J/ψ Ds* Ds*. In these three vertices, the form factors for the J/ψ off-shell case were well fitted by monopolar curves, while the Ds and Ds* off-shell cases were well fitted by exponential curves which is in agreement with the behavior found in previous work of the group. The calculations of the coupling constants leaded to the following results: g_{J/ψ Ds Ds} = 5.98^{+0.67}_{-0.58}, g_{J/ψ Ds* Ds} = 4.30^{+0.41}_{-0.35}GeV^{-1} and g_{J/ψ Ds* Ds*} = 7.47^{+1.04}_{-0.71}, these results are compatible with previous QCDSR works for the non strange vertices J/ψD(*)D(*).
212

Pathfinding with Hard Constraints : Mobile Systems and Real Time Strategy Games Combined

Erdtman, Samuel, Fylling, Johan January 2008 (has links)
There is an abundance of pathfinding solutions, but are any of those solutions suitable for usage in a real time strategy (RTS) game designed for mobile systems with limited processing and storage capabilities (such as the Nintendo DS, PSP, cellular phones, etc.)? The RTS domain puts great requirements on the pathfinding mechanics used in the game; in the form of de- mands on responsiveness and path optimality. Furthermore, the Nintendo DS, and its portable, distant relatives, bring hard con- straints on the processing- and memory resources available to said mechanics. This master thesis aims to find a pathfinding solution well suited to function within the above mentioned, narrow domain. From a broad selection of candidate solutions, a few promising subjects are treated to an investigative empirical study; with the goal of finding the best “fitting” solution, considering the domain. The empirical study shows that the triangle-based TRA* solution and the hierarchical-abstraction influenced Minimal Memory so- lution are both very promising candidates. Depending on how one exactly defines the domain, either one of the solutions could be considered the ‘best’ choice. Since the overall performance of TRA* showed a slight advantage, this solution was further inves- tigated by running an implementation on one of the intended domain platforms; the Nintendo DS. This paper is structured to serve as a guide, of sorts, to some very interesting, and diverse, pathfinding solutions. In the spirit of this effort, all of the more important aspects of these solu- tions, and the pathfinding domain as a whole, are thoroughly explained.
213

Configurable nD-visualization for complex Building Information Models / Konfigurierbare nD-Visualisierung für komplexe Building Information Models

Tauscher, Helga 09 November 2017 (has links) (PDF)
With the ongoing development of building information modelling (BIM) towards a comprehensive coverage of all construction project information in a semantically explicit way, visual representations became decoupled from the building information models. While traditional construction drawings implicitly contained the visual representation besides the information, nowadays they are generated on the fly, hard-coded in software applications dedicated to other tasks such as analysis, simulation, structural design or communication. Due to the abstract nature of information models and the increasing amount of digital information captured during construction projects, visual representations are essential for humans in order to access the information, to understand it, and to engage with it. At the same time digital media open up the new field of interactive visualizations. The full potential of BIM can only be unlocked with customized task-specific visualizations, with engineers and architects actively involved in the design and development process of these visualizations. The visualizations must be reusable and reliably reproducible during communication processes. Further, to support creative problem solving, it must be possible to modify and refine them. This thesis aims at reconnecting building information models and their visual representations: on a theoretic level, on the level of methods and in terms of tool support. First, the research seeks to improve the knowledge about visualization generation in conjunction with current BIM developments such as the multimodel. The approach is based on the reference model of the visualization pipeline and addresses structural as well as quantitative aspects of the visualization generation. Second, based on the theoretic foundation, a method is derived to construct visual representations from given visualization specifications. To this end, the idea of a domain-specific language (DSL) is employed. Finally, a software prototype proofs the concept. Using the visualization framework, visual representations can be generated from a specific building information model and a specific visualization description. / Mit der fortschreitenden Entwicklung des Building Information Modelling (BIM) hin zu einer umfassenden Erfassung aller Bauprojektinformationen in einer semantisch expliziten Weise werden Visualisierungen von den Gebäudeinformationen entkoppelt. Während traditionelle Architektur- und Bauzeichnungen die visuellen Reprä̈sentationen implizit als Träger der Informationen enthalten, werden sie heute on-the-fly generiert. Die Details ihrer Generierung sind festgeschrieben in Softwareanwendungen, welche eigentlich für andere Aufgaben wie Analyse, Simulation, Entwurf oder Kommunikation ausgelegt sind. Angesichts der abstrakten Natur von Informationsmodellen und der steigenden Menge digitaler Informationen, die im Verlauf von Bauprojekten erfasst werden, sind visuelle Repräsentationen essentiell, um sich die Information erschließen, sie verstehen, durchdringen und mit ihnen arbeiten zu können. Gleichzeitig entwickelt sich durch die digitalen Medien eine neues Feld der interaktiven Visualisierungen. Das volle Potential von BIM kann nur mit angepassten aufgabenspezifischen Visualisierungen erschlossen werden, bei denen Ingenieur*innen und Architekt*innen aktiv in den Entwurf und die Entwicklung dieser Visualisierungen einbezogen werden. Die Visualisierungen müssen wiederverwendbar sein und in Kommunikationsprozessen zuverlässig reproduziert werden können. Außerdem muss es möglich sein, Visualisierungen zu modifizieren und neu zu definieren, um das kreative Problemlösen zu unterstützen. Die vorliegende Arbeit zielt darauf ab, Gebäudemodelle und ihre visuellen Repräsentationen wieder zu verbinden: auf der theoretischen Ebene, auf der Ebene der Methoden und hinsichtlich der unterstützenden Werkzeuge. Auf der theoretischen Ebene trägt die Arbeit zunächst dazu bei, das Wissen um die Erstellung von Visualisierungen im Kontext von Bauprojekten zu erweitern. Der verfolgte Ansatz basiert auf dem Referenzmodell der Visualisierungspipeline und geht dabei sowohl auf strukturelle als auch auf quantitative Aspekte des Visualisierungsprozesses ein. Zweitens wird eine Methode entwickelt, die visuelle Repräsentationen auf Basis gegebener Visualisierungsspezifikationen generieren kann. Schließlich belegt ein Softwareprototyp die Realisierbarkeit des Konzepts. Mit dem entwickelten Framework können visuelle Repräsentationen aus jeweils einem spezifischen Gebäudemodell und einer spezifischen Visualisierungsbeschreibung generiert werden.
214

An exploration of the cultural context and consequences of perceptions of illness and health-seeking behaviour of the Baloch

Dashti, Naseer January 2007 (has links)
Human beliefs about health and illness structure the explanations for health and illness in a society and these explanations rationalise preventive or therapeutic strategies. The purpose of this research was to discover, identify and understand the perceptions of health, illness and health seeking behaviour of the Baloch people in a cultural perspective. More specifically, it was to document their perception regarding the origin and cause of illness and disease as revealed in their system of disease-classification and their etiological categories. It was also to describe the context in which Baloch access the traditional health care system as well as conventional health care. Participant observations and in-depth interviews were the tools for data collection in this ethnographic study. Four districts of Pakistani Balochistan were selected for fieldwork. Traditional or folk healers of different categories, medical professionals, sufferers, family heads, community elders, tribal chiefs and medical doctors were interviewed in depth during fieldwork and many socio-cultural phenomena and ritual healing practices were participated in and observed. It was observed that Baloch beliefs regarding health and illness revolve either on the concept of natural causes that are mainly due to humoral imbalance or supernatural causes: spirit possession, sorcery or evil eye. In contemporary Balochistan, despite the availability of the basic health care system in the majority of Baloch settlements, for all practical purposes, Baloch use their traditional medical practices alongside biomedicine. These medical practices mainly consist of herbal remedies and spiritual healing practices. Folk medical beliefs are inseparable from other elements of Baloch cultural life and in this context health planners and medical practitioners in Balochistan, mutually can do much to balance and integrate biomedicine and folk and traditional medicine. Working together, they can optimise the benefits for their client populations.
215

Brick foundations : north Indian brick temple architecture and terracotta art of the fourth to sixth centuries CE

Greaves, Laxshmi January 2015 (has links)
The thesis aims to develop an understanding of the nature and evolution of brick temple architecture in the subcontinent, focusing in particular on terraced Hindu structures of the fourth to sixth centuries CE. It also seeks to advance understanding of the iconography and artistry of the terracotta relief panels that once graced the outer walls or platforms of Gupta period brick temples. To date, scholarship on Hindu temple architecture of the Gupta period has primarily focused on cave and structural stone temples, while brick temple architecture of the epoch, along with terracotta reliefs and sculptures, have largely been confined to the margins of historical studies. This approach has led to the formation of a somewhat distorted picture of the architectural landscape of the Gupta period. To address this shortcoming, all of the known terraced structures in the subcontinent have been mapped in order to establish an understanding of the development and dissemination of this mode of architecture. The architectural form and relief sculpture of the vast terraced brick Śaiva monument known as ACI or Bhimgaja, situated at the heart of the ancient fortress city of Ahichhatrā in Uttar Pradesh, forms the main case study for the thesis - with architecture being the subject of the first half of the thesis. ACI is compared with a terraced brick Vaiṣṇava structure at Pawāyā in Madhya Pradesh, formerly the Nāga centre of Padmāvatī, and with the only standing brick temple of the Gupta period, at Bhītargāon in Uttar Pradesh. Despite the scale and complexity of the former two monuments, neither has received adequate scholarship. A series of fifth- and early sixth-century CE ornamental terracotta pilaster and frieze fragments from Ahichhatrā, held in the reserve collections of the British Museum, are examined within the context of Gupta period temple architecture; the objective being to determine where each of the fragments would have been positioned on a temple. On the basis of these artefacts and related pieces from the site, it is possible to build up a picture of the type of décor that would have adorned the exterior of ACI. The many intriguing sculptures and relief fragments from Pawāyā and Ahichhatrā are the subject of the second half of the thesis. Some of the reliefs - especially those hailing from ACI - are of great importance since they represent some of the earliest visual depictions of myths contained in the Mahābhārata and other religious texts. These reliefs and sculptures are explored within the broader context of Gupta iconography, with particular attention paid to the numerous and fascinating terracotta reliefs of the era, most of which are divorced from their original settings. Moreover, based on style and scale, some of panels evidently share the same origin and these are collated here. In addition, new interpretations are proposed for several of the plaques.
216

Pre-equalization for pre-Rake MISO DS-UWB systems

Torabi, Elham 05 1900 (has links)
In recent years, ultra-wideband (UWB) communications has gained tremendous popularity in both research community and industry. The large bandwidth of UWB systems raises new wireless channel effects and consequently unique advantages as well as challenges to be dealt with, compared to conventional wireless systems. One of these advantages is the ability to resolve dense multipath components and use Rake combining at the receiver in order to significantly reduce the negative effects of fading. However, implementing a Rake receiver with a sufficiently large number of fingers to make use of this advantage is an evident challenge for most UWB devices with limited signal processing capabilities. A possible approach to overcome this problem is to move computational complexity from the receiver to the more powerful transmitter, which is the main focus of the present work. In this thesis, we propose two novel pre-equalization schemes for multiple- input single-output (MISO) direct-sequence ultra-wideband (DS-UWB) systems with pre-Rake combining and symbol-by-symbol detection. The first pre-equalization filter (PEF) scheme employs one PEF per transmit antenna, whereas in the second, simplified PEF (S-PEF) scheme all transmit antennas share the same PEF. For both schemes the optimum finite impulse response (FIR) and infinite impulse response (IIR) PEFs are calculated based on the minimum mean squared error (MMSE) criterion. We show that in contrast to previously proposed schemes for DS-UWB, both our proposed PEF schemes efficiently exploit the channel shortening properties of the pre-Rake filter. In particular, our proposed PEF schemes operate at the symbol level. We also show that under certain conditions the S-PEF scheme achieves the same performance as the more complex PEF scheme. Finally, we demonstrate that a single-input multiple-output (SIMO) DS-UWB system with post-Rake combining and MMSE post-equalization is the dual system to the considered MISO DS–UWB system with pre-Rake combining and MMSE pre-equalization. This uplink-downlink duality can be exploited for efficient calculation of the PEFs and for complexity reduction. Our simulation results show that the proposed PEF schemes achieve significant performance gains over pre-Rake combining without equalization even if only short PEFs are employed, and this is the case even for long UWB channel impulse responses. / Applied Science, Faculty of / Electrical and Computer Engineering, Department of / Graduate
217

Holographic Entanglement Entropy in the dS/CFT Correspondence and Entanglement Entropy in the Sp(N) Model / dS/CFT対応におけるホログラフィック・エンタングルメント・エントロピーとSp(N)模型におけるエンタングルメント・エントロピー

Sato, Yoshiki 23 March 2016 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第19494号 / 理博第4154号 / 新制||理||1597(附属図書館) / 32530 / 京都大学大学院理学研究科物理学・宇宙物理学専攻 / (主査)教授 川合 光, 教授 畑 浩之, 教授 田中 貴浩 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM
218

DEVELOPMENT AND OPTIMIZATION OF BACK SURFACE ACRYLICSOLARMIRRORS TO ASSURE 25 YEAR LIFETIME PERFORMANCE

Murray, Myles P. 19 August 2013 (has links)
No description available.
219

IMPROVED SUBTRACTIVE INTERFERENCE CANCELLATION FOR DS-CDMA

MAO, ZHIYONG 31 March 2004 (has links)
No description available.
220

Bandwidth Efficient Reduced-Complexity MT-DS-SS via Reduced Subcarrier Frequency Spacing

Sen, Indranil 29 July 2004 (has links)
No description available.

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