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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.
441

Les conflits sévères de séparation : les ajustements à la pratique habituelle des intervenants en protection de la jeunesse

Morin, Myriam 05 1900 (has links)
No description available.
442

Nástroje pro automatizaci workflow procesů / Tools for Automating the Workflow Processes

Vančura, Tomáš January 2008 (has links)
The the thesis deals with tools for workflow processes automation. It describes in general what workflow is. It also briefly describes tools such as MS BizTalk Server, SAP NetWeaver, IBM WebSphere, ORACLE BPEL. The main part deals with Windows Workflow Foundation. This tool is decribed in detail together with its parts workflow runtime, workflow instances and workflow activities. One part of the thesis is a application, which uses all the possibilities of Windows Workflow Foundation.
443

Stanovení zkrácených cyklických deformačních křivek superslitiny Inconel 738LC při zvýšených teplotách / Determination of Shortcut Cyclic Stress-strain Curves of Superalloy Inconel 738LC at Elevated Temperatures

Šmíd, Miroslav January 2008 (has links)
Multiple step tests under cyclic strain control have been performed using cylindrical specimens of cast polycrystalline Inconel 738LC superalloy at 23, 700, 500, 800 and 900 °C in laboratory atmosphere to obtain cyclic stress-strain curves. During cyclic straining of specimen were obtained cyclic hardening-softening curves. Their progress changed with temperature and strain amplitude. Evaluated cyclic stress-strain curves are shifted to lower stresses with increasing temperature. Surface relief was observed in fatigued specimens under SEM and metalography under optic microscopy. Slip markings were studied on specimen surface fatigued at 700 °C .Stress-strain response is compared and discussed in relation to the surface observations - persistent slip markings.
444

Analýza alternativ odstraňování PCDD/F při spalování odpadů / Evaluation of the alternatives of PCDD/F removing in the incineration plants

Frýba, Lukáš January 2011 (has links)
The thesis is focused on analyzing the current status of the technology used for cleaning flue gas from persistent organic pollutants, especially PCDD/F. For the three most commonly used methods of solution operational and energy efficiency comparison was made, where achievable energy export and the impact of the change in working conditions on the efficiency indicators of energy production and use of the energy was evaluated. In conditions we considered an alternative machine-technological solutions used for the final disposal of persistent organic pollutants resulting from the waste combustion in terms of additional operating costs and energy efficiency.
445

Synthèse d'οbservateurs pοur des classes de systèmes nοn linéaires avec des sοrties échantillοnnées et retardées / Observer designs for a class of nonlinear systems with delayed sampled outputs

Hernandez Gonzalez, Omar 18 January 2017 (has links)
Les résultats présentés dans cette thèse s’articulent autour de la synthèse d’observateurs de type grand gain pour des classes de systèmes non linéaires. Une classe de systèmes multi-entrées/multi-sorties non uniformément observables a tout d’abord été considérée et un observateur dont le gain est issu de la résolution d’une équation différentielle ordinaire de Lyapunov a été proposé. La convergence exponentielle de l’erreur d’observation sous-jacente a été établie sous une condition d’excitation persistante bien appropriée. La synthèse de l’observateur proposé a été ensuite reconsidérée pour prendre en compte l’échantillonnage et la présence de retard sur la sortie. L’observateur résultant de la resynthèse a une structure en cascade avec des systèmes en chaîne où le premier système de la cascade estime l’état retardé tandis que l’état du dernier système est une estimation de l’état instantané du système. La deuxième classe de systèmes considérée dans cette thèse est une forme normale observable multi-sorties comportant des incertitudes et dont la sortie est échantillonnée et retardée. Un observateur en cascade a été proposé pour l’estimation de l’état instantané du système. Les performances des différents observateurs proposés ont été illustrées à travers plusieurs exemples en simulation tout au long de de la thèse. / The results given in this thesis deal with the design of high gain observers forsome classes on nonlinear systems. A class of multi-inputs/multi-output non uniformlyobservable systems has been first considered and an observer the gain of which is issuedfrom the resolution of a Lyapunov ordinary differential equation has been proposed. Theexponential convergence of the underlying observation error has been established underan appropriate persistent excitation condition. The design of the proposed observerhas then been reconsidered in order to account for the sampling and delay processeswhich may occur on the output. The redesigned observer assumes a cascade structurewith chained systems where the head of the cascade is an observer for the delayedstate while the state of the last system in the cascade constitutes an estimation ofthe system actual state. The second class of systems considered in this thesis is amulti-outputs observable normal form involving some uncertainties and with a delayedsampled output. A cascade observer allowing the estimation of the system actual statehas been proposed. The performance and main properties of the proposed observershave been illustrated in simulation by considering many examples throughout thisthesis.
446

MONARCH - Publikationsserver der Technischen Universität Chemnitz

Blumtritt, Ute 13 May 2005 (has links)
Der Vortrag wurde auf dem 5. Workshop DissOnline: Abschlussworkshop des DFG-Projektes "Aufbau einer Koordinierungsstelle für elektronische Hochschulschriften" am 25. Februar 2005 gehalten. Der Datentransfer elektronischer Hochschulschriften an die Deutsche Bibliothek (DDB) sowie den Südwestdeutschen Bibliotheksverbund (SWB) ist erläutert. Die Technologie zur Erfassung, Aufbereitung und Datenübermittlung ist für das Meldeinterface DDB und SWB äquivalent. Dabei erfolgt die automatische Vergabe von Persistent Identifiern (URN) für jedes Dokument. Die per Onlineformular vom Autor eingetragenen Metadaten werden zur Abholung und Speicherung auf dem Server der Deutschen Bibliothek in das Format XMetaDiss transformiert und über die OAI Schnittstelle zum Download bereitgestellt. Für die in MONARCH achivierten Dissertationen und Habilitationen ist die Langzeitverfügbarkeit und der persistente Zugriff auf den Volltext gesichert.
447

Persistent Inefficiency in the Higher Education Sector: Evidence from Germany

Gralka, Sabine 04 October 2016 (has links)
Evaluations of the Higher Education Sector are receiving increased attention, due to the rising expenditures and the absence of efficiency enhancing market pressure. To what extent universities are able to eliminate inefficiency is a question that has only partially been answered. This paper argues that heterogeneity among universities as well as persistent inefficiency hinder the institutions to achieve full efficiency - at least in the short run. Two standard and one novel specification of the Stochastic Frontier Analysis are applied to a new, comprehensive set of panel data to show how the standard efficiency evaluation changes when both aspects are taken into account. It is the first time that the idea of persistent inefficiency is considered in the analysis of the German Higher Education Sector. The comparison reveals that the disregard of heterogeneity distorts the estimation results towards lower efficiency values. The newly introduced specification improves the accuracy of the heterogeneity assumption and exposes that inefficiency tends to be long term and persistent rather than short term and residual. This implies that increasing efficiency requires a comprehensive change of the university structure.
448

The Transient and Persistent Efficiency of Italian and German Universities: A Stochastic Frontier Analysis

Agasisti, Tommaso, Gralka, Sabine 06 October 2017 (has links)
Despite measures on the European level to increase the compatibility between the HE sectors of the member states, the recent literature exposes variations in their efficiencies. To gain insights into these differences we split the efficiency term according to the two management levels each university is confronted with. Utilizing a recent advancement in the method to measure efficiency, we separate short-term (transient) and long-term (persistent) efficiency, while controlling for unobserved institution specific heterogeneity. While the first term reflects the efficiency of the individual universities working within the country, the second term echoes the influence of the country specific overall HE structure. The cross-country comparison displays if the overall efficiency difference between countries is related to individual performance of their universities or their HE structure. This allows more purposeful policy recommendation and expands the literature regarding the efficiency of universities in a fundamental way. Choosing Italy and Germany as two important illustrative examples we can take advantage of a novel dataset including characteristics of institutions in both countries for an exceptional long period of time from 2001 to 2011. We show that the Italian universities exhibit a higher overall efficiency value than their German counterparts. With the individual universities working at the upper bound of efficiency in both countries, the overall inefficiency as well as the gap between the countries is caused by persistent, structural inefficiency. To expedite a true European Area of Higher Education future measures should hence aim at the country specific structure, not solely at affecting the activities of single universities.
449

Autenticita a digitální informace / Authenticity and Digital Information

Cubr, Ladislav January 2017 (has links)
The dissertation focuses on the authenticity of digitized books in the context of their life cycle (production, preservation, access). First the OIAS high-level conceptual framework for lifecycle management of digital documents maintained by organizations is introduced. Then the current situation of digitized books lifecycle management is described. This part is followed by an introducing to relevant conceptualizations of the authenticity of digital documents and these conceptualizations are analyzed and reviewed. Then framework for analysis of authenticity is established based on previous findings. This framework is then used to identify authenticity requirements for digitized books and to develop a domain-specific conceptualization of the authenticity of digitized books. This conceptualization deploys detailed analysis of risks threatening authenticity during lifecycle management of digitized books. The selected topics of this conceptualization are then the source for the next step, which is to develop a recommended practice for maintaining authenticity of digitized books. This practice is further specified for one partial solution to the problem of maintaining the authenticity of digital documents throughout their life cycle, which is a persistent identification system.
450

Fatigue Behavior of A356 Aluminum Alloy

Nelaturu, Phalgun 05 1900 (has links)
Metal fatigue is a recurring problem for metallurgists and materials engineers, especially in structural applications. It has been responsible for many disastrous accidents and tragedies in history. Understanding the micro-mechanisms during cyclic deformation and combating fatigue failure has remained a grand challenge. Environmental effects, like temperature or a corrosive medium, further worsen and complicate the problem. Ultimate design against fatigue must come from a materials perspective with a fundamental understanding of the interaction of microstructural features with dislocations, under the influence of stress, temperature, and other factors. This research endeavors to contribute to the current understanding of the fatigue failure mechanisms. Cast aluminum alloys are susceptible to fatigue failure due to the presence of defects in the microstructure like casting porosities, non-metallic inclusions, non-uniform distribution of secondary phases, etc. Friction stir processing (FSP), an emerging solid state processing technique, is an effective tool to refine and homogenize the cast microstructure of an alloy. In this work, the effect of FSP on the microstructure of an A356 cast aluminum alloy, and the resulting effect on its tensile and fatigue behavior have been studied. The main focus is on crack initiation and propagation mechanisms, and how stage I and stage II cracks interact with the different microstructural features. Three unique microstructural conditions have been tested for fatigue performance at room temperature, 150 °C and 200 °C. Detailed fractography has been performed using optical microscopy, scanning electron microscopy (SEM) and electron back scattered diffraction (EBSD). These tools have also been utilized to characterize microstructural aspects like grain size, eutectic silicon particle size and distribution. Cyclic deformation at low temperatures is very sensitive to the microstructural distribution in this alloy. The findings from the room temperature fatigue tests highlight the important role played by persistent slip bands (PSBs) in fatigue crack initiation. At room temperature, cracks initiate along PSBs in the absence of other defects/stress risers, and grow transgranularly. Their propagation is retarded when they encounter grain boundaries. Another major finding is the complete transition of the mode of fatigue cracking from transgranular to intergranular, at 200 °C. This occurs when PSBs form in adjacent grains and impinge on grain boundaries, raising the stress concentration at these locations. This initiates cracks along the grain boundaries. At these temperatures, cyclic deformation is no longer microstructure- dependent. Grain boundaries don’t impede the progress of cracks, instead aid in their propagation. This work has extended the current understanding of fatigue cracking mechanisms in A356 Al alloys to elevated temperatures.

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