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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.
1311

On sequencing problems in the management of troubleshooting operations / O problémech seřazení při řízení servisních operací

Lín, Václav January 2016 (has links)
The subject of the thesis belongs to the field of operations management. We deal with sequencing problems arising when there are multiple repair operations available to fix a broken man-made system and the true cause of the system failure is uncertain. It is assumed that the system is formally described by a probabilistic model, and it is to be repaired by a sequence of troubleshooting operations designed to identify the cause of the malfunction and fix the system. The challenge is to find a course of repair which has minimal expected cost. We study several variants of the problem proposed in the literature. We analyze computational complexity of those variants, apply integer linear programming to one variant of the problem, and examine the relation to machine scheduling.
1312

(Dis)continuités des identités et imaginaires en francophonie littéraire : étude comparée des nouvelles de Sévérin Cécile Abéga et de François Mauriac / ( Dis)continuities of identities and imaginaries in Francophone literature : a comparative study of the Novels of Severin Cecile Abéga and François Mauriac

Medouane Ndafang, Edith Bertine 20 December 2013 (has links)
Produites dans une période de questionnement sur l’identité de l’homme et de l’écrivain, les nouvelles littéraires de François Mauriac et de Sévérin Cécile Abéga présentent un imaginaire tantôt symétrique, tantôt non, mais éclairant du rapport entre l’écrivain, son espace et son identité. Le sujet, «(Dis)continuités des identités et imaginaires en francophonie littéraire : étude comparée des nouvelles de Sévérin Cécile Abéga et de François Mauriac » pose le problème des modes de transfiguration des identités et de l’imaginaire dans la nouvelle littéraire francophone. L’hypothèse en est qu’en francophonie littéraire, la pluralité des lieux culturels se reflète dans la diversité d’un genre et implique une certaine cohérence. Cette étude interroge la représentation du cadre spatial et des personnages, les systèmes de valeurs de la société et du genre dans deux postures différentes. Les sujets de cette étude la destine à la critique des imaginaires, et cette approche est enrichie par d’autres lectures comparatistes. Ainsi, on constate que les périodes pendant lesquelles l’écrivain se trouve à la rencontre de tensions historiques,idéologiques et littéraires latentes sont celles où l’imagination créatrice de la nouvelle est réelle. On peut aussi établir que l’espace de la nouvelle est essentiellement celui des auteurs, mais qu’il s’agit d’un espace de désenchantement. Cet univers de déconstruction de l’être implique un univers idéal, un ailleurs qui est chez Mauriac en Dieu et chez Abéga est dans la justice sociale. Les personnages, empêtrés dans cet univers en épousent les valeurs,ce qui entraîne irrémédiablement leur chute. La seule planche de salut est l’humilité,l’ouverture vers le savoir nouveau (le modernisme par exemple) sans reniement de son ancrage identitaire. Abéga comme Mauriac sont donc pour une mixité décomplexée. / Produced in the period when human and writer’s identity is questionable, the novels of FrançoisMauriac and Severin Cecile Abéga have a symmetrical imaginary (sometimes not), but alwaysilluminating the relationship between the writer and his problematic identity. The subject, " ( Dis)continuities of identities and imaginaries in Francophone literature : a comparative study of theNovels of Severin Cecile Abéga and François Mauriac” present the problem of modes oftransfiguration of identities and imagination in the novels. The hypothesis is that in Francophoneliterature, the plurality of cultural aspect is reflected in the diversity of genres, and requires acoherent consistency. This study questions the representation of spatial context and characters, thevalue systems of society and genres in two different postures. The object of this study is intended toarchetypal critics, but this approach is enriched by other comparative readings. Thus, we see that theperiods during which the writer created goes on with historical, ideological and literary tensions. Wecan also establish that space of the novel is essentially the space of authors, but it is an area ofdisenchantment, in opposition with the construction a consistency by the school’s knowledge. Thisworld of deconstruction implies an ideal world, as is the case in Mauriac with supreme knowledge inGod, and in Abéga with a word of social justice. The characters implanted in this context adopt thevalues of their reality, causing their irreparable loss. The only salvation is humility, openness to newknowledge (modernism for example) without denial of his identity anchor. All in all, Abéga asMauriac are for uninhibited mixity.
1313

Etude des effets technologiques par des méthodes numériques innovantes sur des configurations de lanceur . / Assessment of technological effects with innovative numerical methods on launcher configurations

Mochel, Loïc 13 March 2015 (has links)
Aujourd’hui, l’accès à l’espace constitue un enjeu scientifique, technologique et politique d’importance. Il est primordial de pouvoir garantir le succès de la mise sur orbite des satellites pour un coût de transport minimal. Les lanceurs tels qu’Ariane 5 sont soumis à des fluctuations de pression pouvant induire des efforts instationnaires repris par les vérins du moteur Vulcain. Ces efforts s’exercent notamment dans la zone décollée du culot du lanceur normalement à l’axe de la poussée et sont qualifiés de charges latérales. Du point de vue de la simulation numérique, l’étape de discrétisation des éléments technologiques du lanceur rend la génération de maillages structurés particulièrement complexe. Cette constatation conduit à la présente étude. Dans le but d’évaluer l’influence des effets technologiques sur la prévision des charges latérales pour des configurations réalistes de lanceur, la thématique des frontières immergées est étudiée. L’objectif est de développer une stratégie numérique permettant d’accroître le niveau de complexité de la géométrie considérée tout en conservant la précision des résultats des études antérieures sur des configurations simplifiées. Cette stratégie s’inscrit dans le cadre de simulations numériques ZDES d’écoulements massivement décollés d’arrière-corps, à haut nombre de Reynolds et en régime compressible. Les capacités de la méthodologie développée sont évaluées sur des cas tests numériques canoniques avant d’être éprouvées sur des configurations simplifiées de lanceur. Enfin, l’effet de cette stratégie sur la prévision des charges latérales est étudié. / Nowadays, access to space has become a great issue in scientific, technological and political framework. It is essential to ensure the success of the placing of orbiting satellites with a minimal flight cost. Launchers, as the Ariane 5 space launcher, are subject to pressure fluctuations which can lead to unsteady loads on the actuators of the Vulcain engine. These loads occur especially in the separated zone of the launcher base flow and act normally to the thrust axis. They are referred to as side loads. From the numerical simulation perspective, the launcher technological elements discretization process makes the generation of structured mesh particularly difficult. The present study lies within such a framework. In order to assess the influence of the technological effects on the side loads prediction for realistic launcher configurations, immersed boundaries are studied. The aim is to develop a numerical strategy able to increase the level of geometrical complexity of the geometry at stake while maintaining the accuracy of the results of previous studies on simplified configurations. This strategy fits into numerical simulations of ZDES type of separating/reattaching flows at high Reynolds number and compressible regime. The abilities of the methodology are first assessed on canonical numerical test cases. Then, the strategy is applied on simplified launcher configurations. Finally, the effect of this strategy on the side loads prediction is assessed.
1314

Contrôlabilité et complexité : Essai sur la plausibilité de lectures formelles et informelles / Controllability and Complexity : On the Plausibility of Formal and Informal Perspectives

Bonache, Adrien 16 September 2011 (has links)
Objectif – Cette thèse vise à montrer dans quelle mesure les membres d'une organisation peuvent contrôler des situations de gestion complexes. Cette question de recherche est traitée en adoptant deux angles d'analyse. D'une part, nous considérons les liens entre contrôlabilité et complexité, sous l'angle formel. D'autre part, nous traitons cette question, sous l'angle informel.Méthodes – Pour aborder cette question formellement, nous testons la présence de chaos dans des ventes de biens à la mode avec deux méthodes : une estimation, robuste au bruit, de l'exposant maximum de Lyapunov et la dimension de corrélation. Puis, nous évaluons l'horizon de prévisibilité de ces ventes pour savoir dans quelle mesure les membres de l'organisation, chargés du budget, peuvent contrôler ces ventes présentant une « complexité restreinte » au sens de Morin. Pour traiter de cette question de manière informelle, une étude de cas a été réalisée pour montrer qu'il est possible de contrôler des systèmes complexes, présentant un fort couplage au sens de Perrow, en utilisant les solutions mises en avant par la théorie des organisations hautement fiables.Résultats – Que l'on aborde la question des liens entre contrôlabilité et complexité sous l'angle formel ou informel, il apparaît que les membres d'une organisation peuvent contrôler des situations de gestion complexes, de façon décentralisée, dans la mesure où ils possèdent une marge de manœuvre. / Objective – This PhD thesis aims at showing to what extent the members of an organization can control complex management situations. This research question was addressed by adopting two perspectives. We mathematically considered the link between complexity and controllability in the one hand. On the other, weddressed this issue by adopting organizational perspectives.Methods – To address mathematically this matter, the presence of chaos was tested, in some sales of fashion goods, by two methods: an estimation of Lyapunov exponent which is robust to noise and correlation dimension. Then, predictability horizon was estimated in order to know to what extent the members of an organization who set the budget can control these “complex” sales, in Morin's restricted sense. In order to informally deal with this issue, a case study was realized to show that it is possible for the members of an organization to control complex and tight coupled systems, in Perrow's sense, by using the guidelines of the High Reliability Theory.Results – Whatever perspective we take, it appears that the members of an organization can control complex management situations in a decentralized way to the extent that they have a certain amount of latitude.
1315

Conception des chaînes éditoriales : documentariser l'activité et structurer le graphe documentaire pour améliorer la maîtrise de la rééditorialisation / Design of publishing chains : documenting the activity and structuring the graph of document fragments to enhance the mastery of repurposing

Arribe, Thibaut 24 November 2014 (has links)
Les travaux présentés dans ce mémoire traitent de la conception des chaînes éditoriales Numériques XML : des logiciels de production documentaire qui outillent la rédaction de et l'assemblage de ces fragments pour former des documents. fragments La publication des documents s'opère par transformation de fragments XML en documents numériques aux formats standards. La composition des fragments permet d'instrumenter la rééditorialisation documentaire soit l'usage de contenus existants dans la rédaction de documents originaux. La production de documents rééditorialisés implique une modification de la représentation logique des documents de la forme classique d'arbre à celle de graphe de fragments liés entre eux. Ces travaux s'intéressent aux limites rencontrées lorsque la complexité du graphe devient un frein à la production de documents cohérents.Nous avons élaboré une théorie pour la conception des chaînes éditoriales qui s'appuie sur deux approches complémentaires s'articulant autour de la figure de l'atelier - soit l'environnement d'écriture des fragments - pour accompagner les rédacteurs dans l'édition de graphes complexes.La première approche est une articulation interne à l'atelier. Nous proposons de modéliser des fragments pragmatiques dont l'enjeu est d'assister les rédacteurs dans la gestion des fragments tout en enregistrant l'activité sur le graphe. Ces fragments participent à la documentarisation de l'activité puisqu'ils produisent et mettent à jour une documentation des actions opérées sur le graphe.La seconde approche est une articulation externe à l'atelier. Nous proposons de structure rle graphe documentaire dans plusieurs ateliers en fonction des projets éditoriaux (projets de documents à publier) et auctoriaux (projets d'organisation de la production). L'enjeu est d'éclater le graphe dans plusieurs ateliers afin d'en simplifier la perception et donc la manipulation.Nous avons participé aux développements de la suite Scenari afin d'expérimenter notre approche théorique. Les modèles de fragments pragmatiques de la tâche, du fragment commenté, et les responsabilités et cycles de vie sur les fragments ont été développés afin de documentariser l'activité. Les ateliers calques et fragments proxys ont été conçus afin de structurer le graphe. Nos expérimentations nous ont permis de synthétiser une méthodologie pour la conception de chaînes éditoriales exploitant des graphes complexes. Nos travaux se concluent sur une réflexion épistémologique sur la recherche technologique et plus particulièrement sur ses modalités de validité. / This thesis deals with the design of digital XML publishing chains : document production software which allows writing fragments and composing them in order to publish documents. Document publication is computed by transforming XML fragments into digital documents in standard formats. The composition of the fragments allows the repurposing of existing contents into new documents.The writing of repurposed documents involves a change in the logical representation ofdocuments from the classical form of the tree to a graph of linked fragments. This work is dedicated to the limitations encountered when the complexity of the graph becomes an obstacleto the writing of consistent documents.We developed a theory for the design of publishing chains which is based on two complementary approaches around the concept of the writing workspace - the space where the authors write the fragments - to assist writers in the editing of complex graphs.The first approach is internal to the workspace. We propose to model pragmatic fragments intended to assist authors in fragment management while recording graph activity.These fragments are involved in the activity documentarisation since they produce and maintaina documentation of the actions performed on the graph.The second approach is external to the workspace. We propose to structure the graph asseveral workspaces based on publishing and authorial projects. The challenge is to distribute the graph over several workspaces in order to simplify their perception and handling.We participated in the development of Scenari in order to experiment our theoretical approach. The pragmatic fragment models of the task, of the commented fragment, and of there sponsibilities and life cycles on fragments were developed to document the activity. The layerworkspaces and proxy fragments were designed to structure the graph. Our experiments allowed us to summarize a methodology for designing publishing chains which handle complex graphs. Our work is concluded with an epistemological approach in order to qualify and evaluate this technological research.
1316

Intervalová data a výběrový rozptyl: výpočetní aspekty / Interval data and sample variance: computational aspects

Sokol, Ondřej January 2014 (has links)
This thesis deals with the calculation of the upper limit of the sample variance when the exact data are not known but intervals which certainly contain them are available. Generally, finding the upper limit of the sample variance knowing only interval data is an NP-hard problem, but under certain conditions imposed on the input data an appropriate efficient algorithm can be used. In this work algorithms were modified so that, even at the cost of exponential complexity, one can always find the optimal solution. The goal of this thesis is to compare selected algorithms for calculating the upper limit of sample variance over interval data from the perspective of the average computational complexity on the generated data. Using simulations it is shown that if the data meets certain conditions, the complexity of the average case is polynomial.
1317

A complex systems perspective on English language teaching : a case study of a language school in Greece

Kostoulas, Achilleas January 2015 (has links)
This thesis is a complexity-informed case study of a language school in Greece, which provides a rich description of how language pedagogy develops in the periphery of the English-using world. In addition, this study demonstrates the feasibility and potential of using Complex Systems Theory (CST) in the study of educational settings. The thesis begins by describing English Language Teaching (ELT) in Greece, thus setting the scene for the empirical investigation. This is followed by a review of ELT literature, with particular reference to theories of language, pedagogy and society, and by an overview of CST, which pragmatically synthesises complex realism and post-modern ways of knowing, and defines a set of principles to guide complexity-informed empirical inquiry. Having conceptualised the language school as a complex system, it is suggested that activity in the school was sustained by multiple intentionalities, i.e., collective, emergent, nested and generative drivers of activity. These included: (a) an imperative to provide certification to learners, (b) some learners’ desire to integrate in transnational discourse communities, (c) the expectation that language learning should lead to increased awareness of ‘English’ culture, (d) competition against the state school system, and (e) the unstated aim of protecting the professional interests of the school’s staff and stakeholders. Intentionalities were associated with specific pedagogical outcomes and cultural outlooks, and their synthesis is defined as a dynamic of intentions. Next, the thesis looks into the learning materials used at the language school, and it is suggested that these generate affordances which impacted pedagogy. The distribution of learning activities in the books was associated with synchronic and diachronic changes in the dynamics of intentions underpinning activity in the school. Complexity-inspired conceptual instruments, such as an ‘affordance landscape’ and ‘attractors’, are developed to describe the influence of the learning materials, and it is suggested that the learning resources used at the language school made transmissive and communicative pedagogy more likely. The empirical component of the study concludes by describing prototypical instruction sequences that typified ELT in the language school, which evidenced traces of transmissive and communicative pedagogy. Some sequences (e.g., Reading and Vocabulary, and Transmissive Grammar) evidenced transmissive influences, which were associated with local pedagogical traditions, whereas others, such as Process-Based Writing, were more closely aligned with the communicative ideology that is mainstream in ELT. The thesis concludes by synthesising the findings with insights from the CST literature. In doing so, it demonstrates the theoretically generative potential of a complexity-informed inquiry, which can help to formulate understandings of ELT that are sensitive to the interface between systems and their environments, while providing ontologically coherent accounts of structure and agency, and of behaviours that are neither completely random nor entirely predictable.
1318

An exploration of the applicability and usefulness of complexity theory to community development

Plecke, Joanna 11 1900 (has links)
Complexity theory studies the workings of complex adaptive systems (CAS). A complex adaptive system can adapt and change in response to information it gathers from its environment. It responds to feedback by changing its actions, and develops new activities, learning capacity and ability to innovate. Complex adaptive systems depend on information flow through linked networks of individuals and groups, such as those present in cities or communities. Hornby Island, a small northern gulf island in British Columbia, Canada, possesses the characteristics of a complex adaptive system and is used to provide examples of how complexity theory can be applied and used by a community. Observations from Hornby Island and the use of SWOT analysis (strengths, weaknesses, opportunities and threats) have provided insight to the applicability and usefulness of complexity theory in the theoretical and local action contexts of community development. Misunderstandings between the scientific and humanitarian backgrounds of complexity and community development theories represent weaknesses and pose some threats to the field of community development. However, complexity theory also possesses strengths that have the potential to provide community development practitioners and communities with opportunities, such as tools and ideas, to better adapt to change. The following opportunities for learning and action within communities are suggested and expanded upon in this thesis: human led creative adaptation; location of mal-adaptive schemata; education for adaptive schemata; reducing and changing mal-adaptive schemata; guidelines and generalizations; and intangibles and legitimization of actions. This thesis concludes that complexity theory is applicable and useful to community development because it strengthens other theories and concepts related to community development; helps frame what goes on in the community; and locates focuses for change. It also provides new tools and ideas for action, to communities and practitioners, to better deal with change and create resilient communities. / Applied Science, Faculty of / Community and Regional Planning (SCARP), School of / Graduate
1319

Emergentní chování v komplexních informačních systémech / Emergent Behaviour in Complex Information Systems

Tříšková, Petra January 2012 (has links)
This thesis concerns with both practical and theoretical aspects of phenomenon called Emergence. First part has been devoted to the research of available specialized resources on emergent topic and also on main features of complex systems. Acquired knowledge of two topics has been implemented on a real practical example of complex information system by creation of method which purpose is to help finding and determining emergent behavior. Last part of the thesis brings outcome of analysis of real system and discusses the recommendations for researchers on how to determine emergent behavior in their own systems.
1320

Modifikované úlohy čínského listonoše - experimenty / Modified Chinese Postman Problems - Experiments

Jelínek, Tomáš January 2010 (has links)
This master's thesis describes modified Chinese Postman Problems. These Problems are solved by (mixed) integer linear programming. The modified problems and also used approach (integer programming) belong at least to the NP complexity class. The thesis analyzes, compares and estimates computational complexity of each model. Based on this analysis, usability of described models for solving real-life problems is deduced. The models are focused on problems in urban environment. Therefore, it is possible to apply these models on problems like optimization of a waste collection or road maintenance. Graph and problem generator is programmed for purposes of this thesis.

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