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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.
91

Manažerské účetnictví jako nástroj řízení nákladů ve stavebním podniku / Management Accounting as a Tool Costs Management in a Building Company

Matějková, Jana January 2013 (has links)
The thesis is focused on managerial accounting, which serves as a tool for cost control in the construction business. The first part of my work includes introduction to basic concepts, which may be encountered in the use of management accounting. The second part focuses on the practical application of management accounting. With regard to the documents which I received, this section focuses on deviation control.
92

Profitabilita životních smluv a složené GLM / Profitability of life policies and compound GLM

Kostka, Ján January 2022 (has links)
Life insurance policies are not equally profitable is sense of expected value. In practice, profitability is an output of complex cash flow models, which need utilizing special systems and the run time of such calculation can be significant if number of policies is high. Therefore we consider variables, which change most frequently, stimulate the profitability model with several values of these variables and then we search for a regression model to explain the changes. We apply Gamma regression on the data. But what if there exist some policies which are negative? Then we determine these policies with logistic regression applied on data censored to the binary form. Loss of these policies is modelled using symmetrical Gamma model. These three models, when considered together, can be viewed as a single model, which is a generalization of the well known zero inflated count model. The most interesting part of inference in such model is diagnostics. We show that the basic types of residuals - Pearson, deviance and quantile - can be defined. We also build an ordinary linear model and we compare utility of these two approaches. While building models, we meet various statistical issues like dimension reduction of yield curve or dispersion proportional to sum insured. 1
93

The Hubbard model on a honeycomb lattice with fermionic tensor networks

Schneider, Manuel 09 December 2022 (has links)
Supervisor at Deutsches Elektronen-Synchrotron (DESY) in Zeuthen: Dr. Habil. Karl Jansen / Mit Tensor Netzwerken (TN) untersuchen wir auf einem hexagonalen Gitter das Hubbard-Modell mit einem chemischen Potential. Wir zeigen, dass ein TN als Ansatz für die Zustände des Modells benutzt werden kann und präsentieren die berechneten Eigenschaften bei niedrigen Energien. Unser Algorithmus wendet eine imaginäre Zeitentwicklung auf einen fermionischen projected engangled pair state (PEPS) auf einem endlichen Gitter mit offenen Randbedingungen an. Der Ansatz kann auf einen spezifischen fermionischen Paritätssektor beschränkt werden, was es uns ermöglicht, den Grundzustand und den Zustand mit einem Elektron weniger zu simulieren. Mehrere in unserer Arbeit entwickelte Verbesserungen des Algorithmus führen zu einer erheblichen Steigerung der Effizienz und Genauigkeit. Wir messen Erwartungswerte mit Hilfe eines boundary matrix product state. Wir zeigen, dass Observablen in dieser Näherung mit einer weniger starken Trunkierung, als in der Literatur erwartet wird, berechnet werden können. Dies führt zu einer erheblichen Reduzierung der numerischen Kosten des Algorithmus. Für verschiedene Stärken der lokalen Wechselwirkung, sowie für mehrere chemische Potentiale berechnen wir die Energie, die Teilchenzahl und die Magnetisierung mit guter Genauigkeit. Wir zeigen die Abhängigkeit der Teilchenzahl vom chemischen Potential und berechnen die Energielücke. Wir demonstrieren die Skalierbarkeit zu großen Gittern mit bis zu 30 × 15 Gitterpunkten und machen Vorhersagen in einem Teil des Phasenraums, der für Monte-Carlo nicht zugänglich ist. Allerdings finden wir auch Limitierungen des Algorithmus aufgrund von Instabilitäten, die die Berechnungen im Paritätssektor behindern, welcher orthogonal zum Grundzustand ist. Wir diskutieren Ursachen und Indikatoren und schlagen Lösungen vor. Unsere Arbeit bestätigt, dass TN genutzt werden können, um den niederenergetischen Sektors des Modells zu erforschen. Dies eröffnet den Weg zu einem umfassenden Verständnis des Phasendiagramms. / Using tensor network (TN) techniques, we study the Hubbard model on a honeycomb lattice with a chemical potential, which models the electron structure of graphene. In contrast to Monte Carlo methods, TN algorithms do not suffer from the sign problem when a chemical potential is present. We demonstrate that a tensor network state can be used to simulate the model and present the calculated low energy properties of the Hubbard model. Our algorithm applies an imaginary time evolution to a fermionic projected entangled pair state (PEPS) on a finite lattice with open boundary conditions. The ansatz can be restricted to a specific fermionic parity sector which allows us to simulate the ground state and the state with one electron less. Several improvements of the algorithm developed in our work lead to a substantial performance increase of the efficiency and precision. We measure expectation values with a boundary matrix product state and show that observables can be calculated with a lower bond dimension of this approximation than expected from the literature. This decreases the numerical costs of the algorithm significantly. For varying onsite interactions and chemical potentials we calculate the energy, particle number and magnetization with good precision. We show the dependence of the particle number on the chemical potential and compute the single particle gap. We demonstrate the scalability to large lattices of up to 30 × 15 sites and make predictions in a part of the phase space that is not accessible to Monte Carlo methods. However, we also find limitations of the algorithm due to instabilities that spoil the calculations in the parity sector orthogonal to the ground state. We discuss the causes and indicators of such instabilities and propose solutions. Our work validates that TNs can be utilized to study the low energy properties of the Hubbard model on a honeycomb lattice with a chemical potential, thus opening the road to finally understand its phase diagram.
94

What I Lived for

Smith, Rachel Suzanne 20 May 2015 (has links)
No description available.
95

The Germ Theory of Dystopias: Fears of Human Nature in 1984 and Brave New World

Harris, Clea D. 01 January 2015 (has links)
This project is an exploration of 20th century dystopian literature through the lens of germ theory. This scientific principle, which emerged in the late 19th century, asserts that microorganisms pervade the world; these invisible and omnipresent germs cause specific diseases which are often life threatening. Additionally, germ theory states that vaccines and antiseptics can prevent some of these afflictions and that antibiotics can treat others. This concept of a pervasive, invisible, infection-causing other is not just a biological principle, though; in this paper, I argue that one can interpret it as an ideological framework for understanding human existence as a whole. Particularly, I believe that authors of prominent 20th century dystopian novels applied the tenets of germ theory in order to explore the potential “pathogens” that furtively exist within the human mind. These pseudo-germs are various human tendencies that, when left “untreated” by governments, create nonnormative members of society. In the eyes of dystopian regimes, it is precisely this nonnormativity that poses a lethal threat, in that it challenges the continued existence of society with the current ruling body at the helm. In this paper, I trace love (both sexual and familial) and individuation (as a function of social hierarchy, recreational activities, and the use of language) as social disease-causing pathogens in George Orwell’s 1984 and in Aldous Huxley’s Brave New World.
96

從台美兩地北京奧運新聞報導看中國國家形象 / China's image in the coverage of 2008 Beijing-Olympic: A comparison of major newspapers in the US and in Taiwan

黃瀚霆, Huang, Han Ting Unknown Date (has links)
本研究透過分析比較台灣與美國重要報紙媒體上的北京奧運相關報導,檢視中國主辦2008年北京奧運會,所投射出來的媒體國家形象(projected national image),進而探討舉辦全球性媒體活動(global media events)做為國家形象管理策略一環的應用性。本研究挑選台灣的《聯合報》、《自由時報》,與美國的《紐約時報》、《華盛頓郵報》為兩地重要媒體的代表,並經過搜尋篩選程序之後,共得到375則新聞報導。再以內容分析法與框架清單(the list of the frame)分析法,對構成媒體國家形象的各個變項進行相關統計分析。 本研究主要得到三點發現。首先,就台灣與美國報紙整體而言,中國國家形象偏向負面,且報導方向與新聞框架、報導型式之間皆存有顯著關係,而該負面形象的來源,未必是直接與奧運會相關的新聞主題。其次,若將美國報紙與台灣報紙進行比較,則發現兩地的中國國家形象均呈現負面,而台灣報紙的整體報導量以及負面新聞主題較多。另外,本研究發現,同一個國家內的不同媒體之間,也有顯著的差異,《華盛頓郵報》與《自由時報》的負面報導多過中立報導,而《紐約時報》及《聯合報》則仍然以中立報導最多,且《自由時報》的新聞框架運用偏重在政治的角度,而《聯合報》則較多元。 最後,本研究認為北京奧運成功帶來了許多相關的正面主題與正面框架報導,與奧運活動本身較不相關的負面主題,則顯示良好的國家形象需要長期多方面的努力建構。 / To host global media events is one of the important kinds of strategies for the national image management. This study focuses on news coverage of 2008 Beijing-Olympic from the New York Times, Washington Post in the US, and the United Daily, Liberty Times in Taiwan to examine China's projected national image. The content analysis, and the list of the frame analysis were carried out to analyze several variables forming the projected national image in the 375 news items. Through statistic analysis, this study found three main points. First, for four newspapers, China's projected national image was negative. The valence was related to news frames and news style evidently, and also a few indirect news topics were the source of the negative image as well. Secondly, in comparison of newspapers in the US and in Taiwan, both images of china were negative. The total number of stories and negative news topics in Taiwan's newspapers were more than in the US counterpart. Thirdly, in terms of valence, Washington Post and Liberty Times had more negative news than neutral ones, but the neutral news were still the most in the New York Times and United Daily. The Liberty Times reporting had much more political frames, but the United Daily reporting emphasized on several kinds of news frames. Finally, this study found 2008 Beijing-Olympic event brought mass positive news topics and news frames in the news items. The negative news topics showed that building good national image takes much more time and efforts to achieve.
97

Stochastic Combinatorial Optimization / Optimisation combinatoire stochastique

Cheng, Jianqiang 08 November 2013 (has links)
Dans cette thèse, nous étudions trois types de problèmes stochastiques : les problèmes avec contraintes probabilistes, les problèmes distributionnellement robustes et les problèmes avec recours. Les difficultés des problèmes stochastiques sont essentiellement liées aux problèmes de convexité du domaine des solutions, et du calcul de l’espérance mathématique ou des probabilités qui nécessitent le calcul complexe d’intégrales multiples. A cause de ces difficultés majeures, nous avons résolu les problèmes étudiées à l’aide d’approximations efficaces.Nous avons étudié deux types de problèmes stochastiques avec des contraintes en probabilités, i.e., les problèmes linéaires avec contraintes en probabilité jointes (LLPC) et les problèmes de maximisation de probabilités (MPP). Dans les deux cas, nous avons supposé que les variables aléatoires sont normalement distribués et les vecteurs lignes des matrices aléatoires sont indépendants. Nous avons résolu LLPC, qui est un problème généralement non convexe, à l’aide de deux approximations basée sur les problèmes coniques de second ordre (SOCP). Sous certaines hypothèses faibles, les solutions optimales des deux SOCP sont respectivement les bornes inférieures et supérieures du problème du départ. En ce qui concerne MPP, nous avons étudié une variante du problème du plus court chemin stochastique contraint (SRCSP) qui consiste à maximiser la probabilité de la contrainte de ressources. Pour résoudre ce problème, nous avons proposé un algorithme de Branch and Bound pour calculer la solution optimale. Comme la relaxation linéaire n’est pas convexe, nous avons proposé une approximation convexe efficace. Nous avons par la suite testé nos algorithmes pour tous les problèmes étudiés sur des instances aléatoires. Pour LLPC, notre approche est plus performante que celles de Bonferroni et de Jaganathan. Pour MPP, nos résultats numériques montrent que notre approche est là encore plus performante que l’approximation des contraintes probabilistes individuellement.La deuxième famille de problèmes étudiés est celle relative aux problèmes distributionnellement robustes où une partie seulement de l’information sur les variables aléatoires est connue à savoir les deux premiers moments. Nous avons montré que le problème de sac à dos stochastique (SKP) est un problème semi-défini positif (SDP) après relaxation SDP des contraintes binaires. Bien que ce résultat ne puisse être étendu au cas du problème multi-sac-à-dos (MKP), nous avons proposé deux approximations qui permettent d’obtenir des bornes de bonne qualité pour la plupart des instances testées. Nos résultats numériques montrent que nos approximations sont là encore plus performantes que celles basées sur les inégalités de Bonferroni et celles plus récentes de Zymler. Ces résultats ont aussi montré la robustesse des solutions obtenues face aux fluctuations des distributions de probabilités. Nous avons aussi étudié une variante du problème du plus court chemin stochastique. Nous avons prouvé que ce problème peut se ramener au problème de plus court chemin déterministe sous certaine hypothèses. Pour résoudre ce problème, nous avons proposé une méthode de B&B où les bornes inférieures sont calculées à l’aide de la méthode du gradient projeté stochastique. Des résultats numériques ont montré l’efficacité de notre approche. Enfin, l’ensemble des méthodes que nous avons proposées dans cette thèse peuvent s’appliquer à une large famille de problèmes d’optimisation stochastique avec variables entières. / In this thesis, we studied three types of stochastic problems: chance constrained problems, distributionally robust problems as well as the simple recourse problems. For the stochastic programming problems, there are two main difficulties. One is that feasible sets of stochastic problems is not convex in general. The other main challenge arises from the need to calculate conditional expectation or probability both of which are involving multi-dimensional integrations. Due to the two major difficulties, for all three studied problems, we solved them with approximation approaches.We first study two types of chance constrained problems: linear program with joint chance constraints problem (LPPC) as well as maximum probability problem (MPP). For both problems, we assume that the random matrix is normally distributed and its vector rows are independent. We first dealt with LPPC which is generally not convex. We approximate it with two second-order cone programming (SOCP) problems. Furthermore under mild conditions, the optimal values of the two SOCP problems are a lower and upper bounds of the original problem respectively. For the second problem, we studied a variant of stochastic resource constrained shortest path problem (called SRCSP for short), which is to maximize probability of resource constraints. To solve the problem, we proposed to use a branch-and-bound framework to come up with the optimal solution. As its corresponding linear relaxation is generally not convex, we give a convex approximation. Finally, numerical tests on the random instances were conducted for both problems. With respect to LPPC, the numerical results showed that the approach we proposed outperforms Bonferroni and Jagannathan approximations. While for the MPP, the numerical results on generated instances substantiated that the convex approximation outperforms the individual approximation method.Then we study a distributionally robust stochastic quadratic knapsack problems, where we only know part of information about the random variables, such as its first and second moments. We proved that the single knapsack problem (SKP) is a semedefinite problem (SDP) after applying the SDP relaxation scheme to the binary constraints. Despite the fact that it is not the case for the multidimensional knapsack problem (MKP), two good approximations of the relaxed version of the problem are provided which obtain upper and lower bounds that appear numerically close to each other for a range of problem instances. Our numerical experiments also indicated that our proposed lower bounding approximation outperforms the approximations that are based on Bonferroni's inequality and the work by Zymler et al.. Besides, an extensive set of experiments were conducted to illustrate how the conservativeness of the robust solutions does pay off in terms of ensuring the chance constraint is satisfied (or nearly satisfied) under a wide range of distribution fluctuations. Moreover, our approach can be applied to a large number of stochastic optimization problems with binary variables.Finally, a stochastic version of the shortest path problem is studied. We proved that in some cases the stochastic shortest path problem can be greatly simplified by reformulating it as the classic shortest path problem, which can be solved in polynomial time. To solve the general problem, we proposed to use a branch-and-bound framework to search the set of feasible paths. Lower bounds are obtained by solving the corresponding linear relaxation which in turn is done using a Stochastic Projected Gradient algorithm involving an active set method. Meanwhile, numerical examples were conducted to illustrate the effectiveness of the obtained algorithm. Concerning the resolution of the continuous relaxation, our Stochastic Projected Gradient algorithm clearly outperforms Matlab optimization toolbox on large graphs.
98

A porous field: immersive inter-media installation and blurring the boundaries of perception

Verban, Alison Jane January 2007 (has links)
Through creative and theoretical research, this practice-led PhD project investigates the conditions that facilitate embodied sensory awareness within digital inter-media installation. Central to this exploration are questions concerning ‘immersion.’ The research uses this term to describe a transformation in perception that allows us to shake off representational and symbolic meaning in favour of embodied, sensory and intuitive awareness within an installation space. Drawing from embodied memories of immersion in natural and spiritual environments, I consider the elements that contributed to these experiences and ask whether it is possible to create this sense of immersion in art. I then consider the elements that produce immersive, inter-media environments including space, sound, light, and projected moving images. Drawing on theoretical and artistic precedents, I propose a set of principles for producing a sense of embodied sensory immersion. The practical outcomes of the research - three digital inter-media installations included in the exhibition, in an other light - incorporate different combinations and treatments of these material elements to investigate and test the proposed principles.
99

Živé obrazy VJingu / Live images of VJing

Benická, Alexandra January 2011 (has links)
The subject of the thesis Live images of VJing is an aesthetic activity, based on visual projections and on work with new media in real-time, known as VJing, or more generally "live audiovisual performance". As these performances usually complement auditory events or are supplemented by music. The first part follows the origins of VJing out of three angles: First the historical development of projected image, electronic music and the discourse of synaesthesia principle as an principle joining different sensory perceptions into one. Second part of this thesis is introducing an philosophical perspective and it's defining terms, through which can be glimpsed the tendencies in the development of contemporary art of new media, particularly following the example of the German new-media philosophy with terms like homöotechnik, performativity, mediality and gesture. The outcome of this thesis is the finding, that it's not the media-philosophy bringing the textures and shapes to VJing, but the opposite - VJing as an art form is a valuable contribution to defining of the media-philosophy, which seem to be forming along with the new media itself and with the experimental arts exploring it's radical possibilities.
100

Modélisation quantochimiques des forces de dispersion de London par la méthode des phases aléatoires (RPA) : développements méthodologiques / Quantum chemical studies of London dispersion forces by the random phase approximation (RPA) : methodological developments.

Mussard, Bastien 13 December 2013 (has links)
Dans cette thèse sont montrés des développements de l'approximation de la phase aléatoire (RPA) dans le contexte de théories à séparation de portée. On présente des travaux sur le formalisme de la RPA en général, et en particulier sur le formalisme "matrice diélectrique" qui est exploré de manière systématique. On montre un résumé d'un travail sur les équations RPA dans le contexte d'orbitales localisées, notamment des développements des orbitales virtuelles localisées que sont les "orbitales oscillantes projetées" (POO). Un programme a été écrit pour calculer des fonctions telles que le trou de d'échange, la fonction de réponse, etc... sur des grilles de l'espace réel (grilles parallélépipédiques ou de type "DFT"). On montre certaines de ces visualisations. Dans l'espace réel, on expose une adaptation de l'approximation du dénominateur effectif (EED), développée originellement dans l'espace réciproque en physique du solide. Également, les gradients analytiques des énergies de corrélation RPA dans le contexte de la séparation de portée sont dérivés. Le formalisme développé ici à l'aide d'un lagrangien permet une dérivation tout-en-un des termes courte- et longue-portée qui émergent dans les expressions du gradient, et qui montrent un parallèle intéressant. Des applications sont montrées, telles que des optimisations de géométries aux niveaux RSH-dRPA-I et RSH-SOSEX d'un ensemble de 16 petites molécules, ou encore le calcul et la visualisation des densités corrélées au niveau RSH-dRPA-I / In this thesis are shown developments in the random phase approximation (RPA) in the context of range-separated theories. We present advances in the formalism of the RPA in general, and particularly in the "dielectric matrix" formulation of RPA, which is explored in details. We show a summary of a work on the RPA equations with localized orbitals, especially developments of the virtual localized orbitals that are the "projected oscillatory orbitals" (POO). A program has been written to calculate functions such as the exchange hole, the response function, etc... on real space grid (parallelepipedic or of the "DFT" type) ; some of those visualizations are shown here. In the real space, we offer an adaptation of the effective energy denominator approximation (EED), originally developed in the reciprocal space in solid physics. The analytical gradients of the RPA correlation energies in the context of range separation has been derived. The formalism developed here with a Lagrangian allows an all-in-one derivation of the short- and long-range terms that emerge in the expressions of the gradient. These terms show interesting parallels. Geometry optimizations at the RSH-dRPA-I and RSH-SOSEX levels on a set of 16 molecules are shown, as well as calculations and visualizations of correlated densities at the RSH-dRPA-I level

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