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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.
151

Wissensbasierter Aufbau konstruktions-begleitender Finite-Elemente-Analysen durch ein FEA-Assistenzsystem

Kestel, Philipp, Wartzack, Sandro 10 December 2016 (has links) (PDF)
Aus der Einleitung: "Aufgrund der wachsenden Produktanforderungen bei gleichzeitig immer kürzeren Entwicklungszeiten gewinnen computergestützte Simulationsverfahren, wie die Finite-Elemente-Analyse (FEA), in der Produktentwicklung zunehmend an Bedeutung [Müller 2009]. Für eine effiziente Nutzung der FEA muss diese jedoch frühzeitig in der Produktentwicklung angewendet werden. Darüber hinaus wird für einen erfolgreichen Einsatz umfangreiches Expertenwissen vorausgesetzt. Dieses Wissen konzentriert sich in den Unternehmen hauptsächlich auf erfahrene Berechnungsingenieure, die aufgrund zeitlicher Engpässe Simulationen meist nur zur Nachrechnung bereits ausdetaillierter Produktmodelle durchführen. Konstruktionsbegleitende Simulationen werden hingegen zu selten eingesetzt oder sind nicht aussagekräftig genug, wenn diese nicht von Berechnungsexperten erstellt werden. Um den steigenden Anforderungen an die Produktentwicklung gerecht zu werden, muss das erforderliche Simulationswissen daher auch weniger erfahrenen Benutzergruppen, wie Konstruktionsingenieuren, zugänglich gemacht werden. Darüber hinaus müssen wiederkehrende Arbeitsschritte für den Simulationsaufbau standardisiert und automatisiert werden, um die Qualität der Berechnungsergebnisse abzusichern und diese Prozesse zu beschleunigen. ..."
152

Geoffrey Dawson, Editor of The Times (London), and His Contribution to the Appeasement Movement

Riggs, Bruce T. (Bruce Timothy) 12 1900 (has links)
The appeasement movement in England sought to remove the reasons for Adolph Hitler's hostility. It did so by advocating a return to Germany of land and colonial holdings, and a removal of the penalties inflicted upon Germany by the Treaty of Versailles. While the movement itself is well documented, the contribution of The Times under the leadership of Geoffrey Dawson is not. This work deals with his direct involvement with appeasement, the British leaders and citizens involved in the movement, and the use of The Times to reinforce their program.
153

Voice Onset Time Characteristics of Selected Phonemes in Young and Old Male Speakers

Thomas, Kathy Wright 12 1900 (has links)
The purpose of the investigation was to compare mean voice onset time in young and old male subjects, as well as to examine variability of VOT productions with age for prevocalic bilabial, alveolar, and velar voiced and voiceless stop consonants. Forty-five Caucasion.males were divided equally into three.age groups. Ten tokens of six stimulus words were recorded and wide band spectrograms were made. Results of an analysis of variance revealed no significant differences in VOT with age when averages of the phonemes were used for analysis; however, a significant interaction between age and voiced phonemes was found when individual trials of phoneme productions were used for analysis.
154

The Effect of Monetary Reward and Knowledge of Results on Complex-Choice Reaction Times

Davies, Terry Barnett 05 1900 (has links)
This investigation was designed to determine relative effects of monetary reward and knowledge of results on complex-choice reaction time tasks. Subjects were twenty-five male and thirty-two female undergraduate students. Apparatus consisted of nine stimulus lights and eight response keys. Subjects were required to add the number of lights presented, subtract the sum from a constant, and press the correctly numbered response key. Reward subjects received twenty-five cents for responses faster than a predetermined criterion, and twenty-five cents was deducted for slower responses. Knowledge of results subjects were told their reaction times after each trial. Results indicated (1) no significant differences between any conditions, (2) a significant overall practice effect (.01 level), and (3) that males were significantly faster than females (.01 level).
155

Částice se spinem v algebraicky speciálních prostoročasech / Spinning particles in algebraically special space-times

Šrámek, Milan January 2013 (has links)
Spinning-particle motion is studied, within the pole-dipole approximation, in algebraically special space-times of type N, III and D. The spin-curvature interaction is analysed for the Pirani and Tulczyjew spin supplementary conditions; for N and D types, the condition is related to a relative acceleration of two near observers separated in the direction of particle's spin. For Tulczyjew's condition, the momentum-velocity relation is also studied as well as its consequences for the spin-curvature interaction. Finally, the type of motion is mentioned for which both the supplementary conditions considered are equivalent.
156

Zobrazení každodennosti velkomětského života na příkladu Berlína v románech přelomu dvacátých a třicátých let 20. století / The Depiction of Everyday Life in the City in the Novels at the Turn of the 1920s and 1930s: The Case of Berlin

Nováková, Barbora January 2014 (has links)
This master's thesis attempts to present the literary conception of a modern pulsing German metropolis at the end of the 1920s and the beginning of the 1930s in three significant novels of that time: Döblin's Berlin Alexanderplatz. Die Geschichte vom Franz Biberkopf (1929), Kästner's Fabian. Die Geschichte eines Moralisten (1931) and Keun's Das kunstseidene Mädchen (1932). Attention is paid, on the one hand, to the picture of a babbling city, the presence of technology, new means of transport and advertising in the streets. Most importantly, however, the thesis gives an insight into the social situation of that time, i.e. the issues of everyday life in a metropolis which can be summarized, in the words of the personae, under the term "hard times" - unemployment, criminality or the politicisation of inhabitants in the years before the Nazi seizure of power. In addition, the thesis covers likewise the situation of the new social stratum of employees, the fates of women and an outline of cultural, entertainment and media industry in Berlin. Powered by TCPDF (www.tcpdf.org)
157

Vznik deníku The New York Times / The birth of The New York Times

Váňa, Tomáš January 2011 (has links)
The diploma thesis The birth of the daily The New York Times deals with the birth and evolution of the daily newspaper The New York Times. It analyses its birth on the background of the state of American journalism in the middle of the nineteenth century. It deals with the rise of the penny press and the founding of the most important papers of this era, mainly New York Sun, New York Herald and New York Tribune. The birth of The New York Times is described as a natural step in the filling of a gap on the publishing market, which lacked a serious and unbiased paper. After describing the founding of The New York Times the thesis deals with the two most important eras in the history of the paper. These are the period after the death of its founder Henry Jarvis Raymond, when the paper was lead by his old collaborator George Jones and the repeated rise of the paper under Adolph S. Ochs at the turn of the nineteenth century. In the final part of this thesis, the state of the paper at the start of the twenty-first century is described. A description of the atmosphere of this explored era, the social conditions in USA in the middle of the nineteenth century and the situation on the media market also forms a part of this thesis. A part of the thesis is dedicated to short passages summarizing the lives of the...
158

The timescales of magmatic processes prior to a caldera-forming eruption / Les échelles de temps des processus magmatiques avant une éruption caldérique

Fabbro, Gareth Nicholas 24 April 2014 (has links)
Les grandes éruptions caldériques sont parmi les phénomènes les plus destructeurs de la Terre, mais les processus à l’origine des grands réservoirs de magma siliceux et pauvre en cristaux qui alimentent ces éruptions ne sont pas bien compris. Le temps de stockage de ces réservoirs dans la croûte supérieure a un intérêt particulier. De longs temps de stockage—jusqu’à 105 ans—ont été estimés en utilisant les temps de repos entre les éruptions et les âges radiométriques des cristaux qui se trouvent dans les produits éruptifs. Par contre, des travaux récents sur la diffusion dans des cristaux suggèrent que les réservoirs qui alimentent même les plus grandes éruptions peuvent se mettre en place pendant une période beaucoup plus courte—101–102 ans. Afin de répondre à cette question, j’ai étudié l’éruption dacitique de Cape Riva de Santorin, Grèce (>10km3, 22 ka). Pendant les 18.000 ans précédant cette éruption, une série de dômes et de coulées dacitiques a été émise, alternant avec des dépôts de ponce dacitique (le complexe de dômes de Therasia). Ces dacites ont des compositions similaires à celle qui a été émise pendant l’éruption de Cape Riva, et ont été décrites précédemment comme des « fuites » provenant du réservoir de Cape Riva pendant sa croissance. Cependant, le magma de Cape Riva est appauvri en éléments incompatibles (tels que K, Zr, La, Ce) par rapport au magma de Therasia, une différence qui apparaît également dans les cristaux de plagioclase. Cette différence ne peut pas être expliquée par des processus peu profonds, tels que la cristallisation fractionnée ou l’assimilation de la croûte, ce qui suggère que les magmas de Cape Riva et Therasia ont des origines différentes. En outre, il existe des arguments tendant à montrer que les dacites de Therasia n’ont pas été alimentées par un réservoir majoritairement liquide ayant eu une longue durée de vie. Il y a des variations non systématiques dans la composition du magma, les compostions des bords ainsi que les caractéristiques des cristaux de plagioclase tout au long de la séquence. De plus, les temps de résidence à haute température des cristaux de plagioclase et d’orthopyroxène estimés par des modèles de diffusion sont 101–102 ans. Ces temps sont courts par rapport au temps moyen entre éruptions (1.500 ans), ce qui suggère que les cristaux observés dans chaque coulée ne se sont formés que peu de temps avant l’éruption. Les différentes teneurs en éléments incompatibles indiquent qu’un nouveau magma s’est mis en place dans le système volcanique superficiel peu de temps avant l’éruption de Cape Riva. Cet apport de magma a eu lieu après la dernière éruption de Therasia, qui s’est produite <2.800±1.400 ans avant l’éruption de Cape Riva selon les âges 40Ar/39Ar. Les périphéries des cristaux de plagioclase présents dans la dacite de Cape Riva sont en équilibre avec une rhyodacite, avec une composition similaire à celui du verre de l’éruption. Cependant, les zonations dans les éléments majeurs et traces enregistrent des changements dans la composition du liquide magmatique pendant la croissance des cristaux. La composition du centre de la plupart des cristaux de plagioclase est la même que celle des bords ; toutefois ces cristaux sont souvent partiellement résorbés, et la croissance a repris avec du plagioclase plus calcique. Ces cycles se répètent jusqu’à trois fois. La relation étroite entre la teneur en anorthite, Sr et Ti des différentes zones suggère que la composition des plagioclases est corrélé avec la composition du liquide, allant de liquides dacitiques à rhyodacitiques. Des cristaux d’orthopyroxène révèlent une séquence similaire. Les motifs de zonation sont interprétés comme un témoin de la formation du réservoir de Cape Riva dans la croûte supérieure par le mélange de plusieurs magmas ayant des compositions diverses. Des modèles de diffusion de Mg dans le plagioclase et de Fe–Mg dans l’orthopyroxène suggèrent que ce mélange a eu lieu 101–102 ans avant l’éruption. / Large, explosive, caldera-forming eruptions are amongst the most destructive phenomena on the planet, but the processes that allow the large bodies of crystal-poor silicic magma that feed them to assemble in the shallow crust are still poorly understood. Of particular interest is the timescales over which these reservoirs exist prior to eruption. Long storage times—up to 105 y—have previously been estimated using the repose times between eruptions and radiometric dating of crystals found within the eruptive products. However, more recent work modelling diffusion within single crystals has been used to argue that the reservoirs that feed even the largest eruptions are assembled over much shorter periods—101–102 y. In order to address this question, I studied the >10km3, 22-ka, dacitic Cape Riva eruption of Santorini, Greece. Over the 18 ky preceding the Cape Riva eruption a series of dacitic lava dome and coulées were erupted, and these lavas are interspersed with occasional dacitic pumice fall deposits (the Therasia dome complex). These dacites have similar major element contents to the dacite that was erupted during the Cape Riva eruption, and have previously been described as “precursory leaks” from the growing Cape Riva magma reservoir. However, the Cape Riva magma is depleted in incompatible elements (such as K, Zr, La, Ce) relative to the Therasia magma, as are the plagioclase crystals in the respective magmas. This difference cannot be explained using shallow processes such as fractional crystallisation or crustal assimilation, which suggests that the Cape Riva and Therasia magmas are separate batches. Furthermore, there is evidence that the Therasia dacites were not fed from a long-lived, melt-dominated reservoir. There are non-systematic variations in melt composition, plagioclase rim compositions, and plagioclase textures throughout the sequence. In addition, high-temperature residence times of plagioclase and orthopyroxene crystals from the Therasia dacites estimated using diffusion chronometry are 101–102 y. This is short compared to the average time between eruptions (1,500 y), which suggests the crystals in each lava grew only shortly before eruption. The different incompatible element contents of the Cape Riva and Therasia magmas and plagioclase crystals suggest that a new batch of incompatible-depleted silicic magma arrived in the shallow volcanic plumbing system shortly before the Cape Riva eruption. This influx must have taken place after the last Therasia eruption, which 40Ar/39Ar dates show occurred less than 2,800±1,400 years before the Cape Riva eruption. The rims of the plagioclase crystals found in the Cape Riva dacite are in equilibrium with a rhyodacite, with a similar composition to the Cape Riva glass. However, the major and trace element zoning patterns of the crystals record variations in the melt composition during their growth. The compositions at the centre of most crystals are the same as the rims; however, these crystals are often partially resorbed and overgrown by more calcic plagioclase. The plagioclase then grades normally back to rim compositions. This cycle is repeated up to three times. The tight relationships between the anorthite, Sr and Ti contents of the different zones suggests that the composition of the plagioclase crystals correlates with the composition of the melt from which theygrew. The different plagioclase compositions correspond to dacitic and rhyodacitic melt compositions. The orthopyroxene crystals reveal a similar sequence, although they only record one cycle. These zoning patterns are interpreted to document the assembly of the Cape Riva reservoir in the shallow crust through the amalgamation of multiple batches of compositionally diverse magma. Models of magnesium diffusion in plagioclase and Fe–Mg interdiffusion in orthopyroxene suggest that this amalgamation took place within 101–102 y of the Cape Riva eruption.
159

Ausgelagert und unsichtbar: Arbeitsbedingungen in der Reinigungsbranche

Sardadvar, Karin January 2019 (has links) (PDF)
Der Beitrag beschäftigt sich damit, in welcher Weise Reinigungsarbeit - als ein typischer Bereich sogenannter "Einfacharbeit" - in den vergangenen Jahrzehnten von Auslagerungen betroffen war und wie sie davon geprägt wurde. Er stellt aktuelle Branchencharakteristika und Beschäftigungsbedingungen zur Reinigungsbranche in Österreich im internationalen Kontext dar und argumentiert, dass die mit der Auslagerung verbundenen Veränderungen der Reinigungsarbeit problematische Arbeits- und Beschäftigungsbedingungen verstärken. So tragen insbesondere die verbreiteten Arbeitszeiten an den Tagesrändern zu einer Unsichtbarmachung der Arbeit bei, die einer mangelnden Anerkennung weiter Vorschub leistet. Die Tendenz zur gesellschaftlichen Unsichtbarmachung spiegelt sich daneben auch in der wissenschaftlichen und gesellschaftlichen (Nicht-)Zuwendung zu "Einfachdienstleistungen" und der Reinigung im Speziellen wider. Der Beitrag geht weiters auf die Rolle des Wohlfahrtsstaates in der Gestaltung der Arbeits- und Lebensbedingungen von in "Einfachdienstleistungen" Beschäftigten ein. Abschließend weist er auf Ansatzpunkte für Verbesserungen auf unterschiedlichen Ebenen hin.
160

Programação de produção e dimensionamento de lotes para flowshop / Production scheduling and lot sizing for flowshop

Belo Filho, Marcio Antonio Ferreira 06 October 2010 (has links)
O problema integrado de programação de produção e dimensionamento de lotes em ambiente fowshop consiste em estabelecer tamanhos de lotes de produção e alocar máquinas para processá-los dentro de um horizonte de planejamento, em uma linha de produção com máquinas dispostas em série. O problema considera que a demanda deve ser atendida sem atrasos, que a capacidade das máquinas deve ser respeitada e que as preparações de máquinas são dependentes da sequência de produção e preservadas entre períodos do horizonte de planejamento. O objetivo é determinar uma programação de produção visando minimizar os custos de preparação de máquina, de produção e de estoque. Um modelo matemático da literatura é apresentado assim como procedimentos para obtenção de limitantes inferiores. Além disso, abordamos o problema por meio de distintas versões da metaheurística Times Assíncronos (A-Teams). Os procedimentos propostos foram comparados com heurísticas da literatura baseadas em Programação Inteira Mista (MIP). As metodologias desenvolvidas e os resultados obtidos são apresentados nesta dissertação / The integrated production scheduling and lot sizing problem in a fowshop environment consists in establishing production lot sizes and alocate machines to process them inside a planning horizon, in a production line with machines arranged in series. The problem considers that demand must be met without backlogging, the capacity of the machines must be respected, machine setup are sequence-dependent and preserved between periods of the planning horizon. The objective is to determine a production schedule to minimize the setup, production and inventory costs. A mathematical model from the literature is presented as well as procedures for obtaining lower bounds. In addition, we propose to address the problem through different versions of the metaheuristic Asynchronous Teams (A-Teams). The procedures were compared with literature heuristics based on Mixed Integer Programming (MIP). The developed methodologies and the obtained results are presented in this dissertation

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