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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.
161

Estudo das variáveis limnológicas e do processo de autodepuração na \"descontinuidade serial\" do Ribeirão Bonito (SP) / A study of the limnological variables and the self-cleaning process in the \"serial discontinuity\" of the Bonito stream (SP)

Simone Frederigi Benassi 21 June 2002 (has links)
Este trabalho teve como objetivo estudar o comportamento espaço-temporal das variáveis limnológicas, no Ribeirão Bonito (SP) a fim de avaliar a descontinuidade ocasionada pelas fontes poluidoras e o processo de autodepuração. Para tanto, foram determinadas variáveis físico-químicas, biológicas, climatológicas e hidrológicas, no eixo longitudinal do rio e utilizado como ferramenta para diferentes cenários de simulações das concentrações de oxigênio dissolvido, o modelo QUAL2E. Foi possível observar, que muitas das variáveis limnológicas estudadas no Ribeirão Bonito sofrem \"descontinuidades\" devido à entrada de esgoto. As concentrações de oxigênio dissolvido têm um gradiente positivo da nascente até a estação 4, sofrendo uma descontinuidade após a estação 6 onde detecta-se o primeiro lançamento de esgoto. O comportamento dessa variável após a entrada de esgoto foi distinto nos dois períodos estudados. As análises de \"Cluster\" e PCA (Análise dos Componentes Principais), realizadas com as médias das variáveis limnológicas, distinguiram diferentes grupos no perfil longitudinal do ribeirão Bonito. Essa distinção pode ser atribuída às já citadas entradas de efluentes e também em decorrência da presença do tributário do Curtume. Pode-se constatar que mesmo com o auxílio natural do processo de autodepuração, muitas das variáveis estudadas não se enquadram aos padrões do corpo receptor conforme previsto pela resolução número 20/86 do CONAMA, sugerindo assim, neste trabalho, um grau de tratamento dos efluentes para que estes padrões sejam respeitados. / The objective of the present paper is to study the spatial-temporal behaviour of the limnological variables, in Bonito stream (SP), in order to evaluate the discontinuity occasioned by the sources of pollution and the self-cleaning process. To this effect, a survey was made to determine the physical-chemical, biological, climatological and hydrological variables in the longitudinal axis of the river and which utilized the QUAL2E model as a tool for simulating the concentrations of dissolved oxygen under different scenarios. It was possible to observe that many of the limnological variables studied in the Bonito rivulet suffer \"discontinuities\" due the entry of sewage. The concentrations of dissolved oxygen show a positive gradient from the source of the watercourse until station 4, and suffer a discontinuity after station 6, where the first discharge of sewage begins. The behaviour of this variable after the entry of sewage differed during the two periods studied. Furthermore, the \"Cluster\" and PCA (Principal Component Analyses) carried out upon the averages of the limnological variables distinguished different groups in the longitudinal profile of the Bonito rivulet. This distinction can be attributed to the above-mentioned entries of effluents and also resulting from the presence of the Curtume tributary. It can be verified that even with the natural assistance of the self-cleaning process, many of the variables studied fail to meet the standards of the receiving body, as stipulated by the CONAMA resolution number 20/86, in view of which, the present study suggests a degree of effluent treatment in order for these standards to be respected.
162

Uma análise de impacto da guarda municipal no Brasil

Vital, Tauã Magalhães 20 February 2018 (has links)
Submitted by Geandra Rodrigues (geandrar@gmail.com) on 2018-06-14T12:49:23Z No. of bitstreams: 1 tauamagalhaesvital.pdf: 1157943 bytes, checksum: b82b68f320daf8c911fbb74c2bd54ea6 (MD5) / Rejected by Adriana Oliveira (adriana.oliveira@ufjf.edu.br), reason: on 2018-06-14T12:51:19Z (GMT) / Submitted by Geandra Rodrigues (geandrar@gmail.com) on 2018-06-14T12:52:52Z No. of bitstreams: 1 tauamagalhaesvital.pdf: 1157943 bytes, checksum: b82b68f320daf8c911fbb74c2bd54ea6 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2018-06-27T15:07:41Z (GMT) No. of bitstreams: 1 tauamagalhaesvital.pdf: 1157943 bytes, checksum: b82b68f320daf8c911fbb74c2bd54ea6 (MD5) / Made available in DSpace on 2018-06-27T15:07:41Z (GMT). No. of bitstreams: 1 tauamagalhaesvital.pdf: 1157943 bytes, checksum: b82b68f320daf8c911fbb74c2bd54ea6 (MD5) Previous issue date: 2018-02-20 / O objetivo desta dissertação é avaliar o impacto que as guardas municipais exercem na taxa de criminalidade, e ainda avaliar se o uso de armamentos letais ou não-letais por parte dessas guardas impacta de alguma na redução do crime. A metodologia a ser empregada consiste em dois métodos, diferenças-em-diferenças com correção espacial e o método de regressão descontínua (regression discontinuity design – RDD). O primeiro método visa avaliar o impacto das guardas municipais na taxa de crimes entre os anos de 2004 e 2012, visto que houve um grande aumento no número de municípios com guardas municipais dentro deste período. O segundo método analisa o uso de armas letais ou não-letais por parte das guardas municipais no ano de 2009 a partir da descontinuidade em torno dos municípios com cinquenta mil habitantes, valor este definido pelo Estatuto do Desarmamento, que estabelecia que apenas municípios com população superior a este valor poderiam possuir guardas municipais com armamentos letais. Os resultados encontrados apontam que a presença de guarda municipal, bem como o uso de armas de fogo pela mesma, não impacta significativamente a taxa de criminalidade / The aim of this dissertation is to evaluate the impact of municipal guards on the crime rate, and also to evaluate if the use of lethal and non-lethal weapons by these institutes cause any impact in crime. The methodology consists of two methods, spatial differences in differences and the regression discontinuity design (RDD). The first method is to evaluate the impact of municipal guards on the crime rate between 2004 and 2012, since there was a large increase in the number of municipalities that implemented municipal guards within this period. The second method analyzes the impact of the use of lethal or non-lethal weapons by municipal guards in 2009, as a result of the discontinuity around municipalities with fifty thousand inhabitants, a value defined by the Disarmament Statute, which established that only municipalities with population above this value could have municipal guards with lethal armaments. The results indicate that the presence of municipal guard, as well as the use of firearms by them, does not significantly impact the crime rate.
163

Dynamic Capabilities in IT-assisted Alliance Creation: A Study of Higher Education Institutions

Mehmedovic, Tarik January 2012 (has links)
Dynamic capabilities, a relatively new concept in strategic management, are subject to a variety of streams and points of view in the available literature, where the focus is still mainly on debating the general concepts, overall frameworks and classifications. The current consensus is that dynamic capabilities are highly context-based, depending on firm types, timeframes and a variety of other factors. However, what current research fails to adequately address are studies of individual cases of particular types of firms in their specific business environments, as well as how dynamic capabilities and their foundations are created and how they evolve in a specific, limited context. What these individual cases can contribute to the overall area of research are refined tools and frameworks for context-specific creation of dynamic capabilities, and thus their importance cannot be ignored. This study uses qualitative research to observe a case of a commercial higher-education institution in Sarajevo, Bosnia and Herzegovina, a developing market. The organization is highly IT-reliant, and one of the main characteristics of the institution is its flexibility and adaptability to change. In the recent couple or years, the institution switched several crucial partners, whose resources it uses for teaching. These factors make this organization interesting for investigation of dynamic capabilities in the particular context of constant change. The study uses mainly observation, but is supplemented by an interview and questionnaires. The researcher spent time working at the institution during a crucial timeframe of alliance-switching, and this experience fuels the observation. The results, including a developed model, present a good way to observe dynamic capabilities in a particular context, one based on activities and foundations that fuel dynamic capabilities in organizations.
164

Localized failure in dynamics for brittle and ductile materials / Défaillance localisée dans la dynamique des matériaux fragiles et ductiles

Do, Xuan Nam 24 May 2017 (has links)
La défaillance des matériaux et structures d'ingénierie peut être considéré comme le résultat d'une interaction complexe entre différents phénomènes physiques tels que la nucléation des cavités, les microfissures, les microvides et d'autres processus irréversibles. Ces micro-défauts se fondent éventuellement en une ou plusieurs macro-fissures conduisant à une diminution de la capacité portante et finalement à une défaillance de la structure considérée. La prévention des défaillances des structures et des composants structurels a toujours été un sujet important et une préoccupation majeure en ingénierie. Cette thèse vise à représenter une défaillance localisée dans des matériaux non linéaires sans dépendance de maillage. Un intérêt particulier sera le cas de l’adoucissement dynamique des déformations. Les phénomènes localisés sont pris en compte en utilisant l'approche des discontinuités embarquées fortes dans laquelle le champ de déplacement est amélioré pour capturer la discontinuité. Sur la base de cette approche, on a d'abord développé un modèle unidimensionnel de barres élasto-plastique capable de représenter une défaillance pour des matériaux ductiles avec un durcissement combiné dans une zone de processus de fracture FPZ et un adoucissement avec des discontinuités fortes encastrées. Les résultats comparant le modèle unidimensionnel proposé aux travaux (semi-) analytiques sont présentés. Il a été démontré que la stratégie proposée offre des solutions indépendantes de maillage. La déformation augmente dans le domaine de l’adoucissement avec une diminution simultanée de la contrainte. Le problème se décharge élastiquement à l'extérieur de la zone d’adoucissement de déformation. L'énergie dissipée se trouve à disparaître. Le modèle a également été comparé à un modèle de dommage unidimensionnel capable de représenter la fracture dynamique de la barre d'endommagementélasto-endommagée dans la zone de traitement de fracture - FPZ et de adoucissement avec de discontinuités fortes encastrées pour trouver un bon accord entre deux modèles. Un modèle d'éléments finis bidimensionnel a été développé, capable de décrire à la fois le mécanisme de dommage diffus accompagné d'un durcissement initial et d'une réponse d’adoucissement ultérieure de la structure. On a analysé les résultats de plusieurs simulations numériques effectuées sur des essais mécaniques classiques sous des charges progressivement croissantes telles que le test Brésilien ou le test de flexion en trois points. Le cadre de dynamique proposé est montré pour augmenter la robustesse de calcul. On a constaté que la direction finale des macro-fissures est assez bien prédite et que l'influence des effets d'inertie sur les solutions obtenues est assez modeste notamment en comparaison entre différentes mailles. Ce modèle bidimensionnel a été étendu plus loin dans le modèle bidimensionnel de discontinuité intégrée en viscodamage pour aider à explorer brièvement la mise en œuvre du schéma de point intermédiaire de second ordre qui peut fournir des résultats améliorés sous limitation de la régularisation visqueuse du modèle de dégâts localisés. / Failure of engineering materials and structures can be considered as a result of a complex interplay between different physical phenomena such as nucleation of cavities, microcracks,microvoids and other irreversible processes. These micro-defects eventually coalesce into one or more macro-cracks leading to a decrease in the load-bearing capability and finally, to failure of the structure under consideration. Prevention of failure of structures and structural parts has always been a critical subject and a major concern in engineering. This thesis aims to represent localized failure in non linear materials without mesh dependency. Of special interest will be the case of dynamic strain-softening. Localized phenomena are taken into account by using the embedded strong discontinuities approach in which the displacement field is enhanced to capture the discontinuity. Based upon this approach, a one-dimensional model for elasto-plastic bar capable of representing failure for ductile materials with combined hardening in FPZ-fracture process zone and softening with embedded strong discontinuities was first developed. Results comparing the proposed one-dimensional model to (semi-) analytical works are presented. It was shown that the proposed strategy provides mesh independent solutions. Strain increases in the softening domain with a simultaneous decrease of stress. The problem unloads elastically outside the strain softening region. The strain energy is found to vanish. The model was also compared with a one dimensional damage model capable of representing the dynamic fracture for elasto-damage bar with combined hardening in fracture process zone - FPZ and softening with strong embedded discontinuities to find a good agreement between two models. A two-dimensional finite element model was developed, capable of describing both the diffuse damage mechanism accompanied by initial strain hardening and subsequent softening response of the structure. The results of several numerical simulations, performed on classical mechanical tests under slowly increasing loads such as Brazilian test or three-point bending test were analyzed. The proposed dynamics framework is shown to increase computational robustness. It was found that the final direction of macro-cracks is predicted quite well and that influence of inertia effects on the obtained solutions is fairly modest especially in comparison among different meshes. This two-dimensional model was expanded further into the two dimensional continuum viscodamage-embedded discontinuity model to help briefly explore the implementation of the second order mid-point scheme that can provide improved results under limitation of viscous regularization of localized failure damage model.
165

Nutrition and Child Development in Low- and Middle-Income Countries - Evaluation of Three Micronutrient Interventions

Krämer, Marion 02 June 2017 (has links)
No description available.
166

Approximations elliptiques d'énergies singulières sous contrainte de divergence / Elliptic approximations of singular energies under divergence constraint

Monteil, Antonin 07 December 2015 (has links)
Cette thèse est consacrée à l’étude de certains problèmes variationnels de type transition de phase vectorielle ou "phase-field" qui font intervenir une contrainte de divergence. Ces modèles sont généralement basés sur une énergie dépendant d’un paramètre qui peut représenter une grandeur physique négligeable ou qui est liée à une méthode d’approximation numérique par exemple. Une question centrale concerne alors le comportement asymptotique de ces énergies et des minimiseurs globaux ou locaux lorsque ce paramètre tend vers 0. Cette thèse présente différentes stratégies prenant en compte la contrainte de divergence. Elles seront illustrées à travers l’étude de deux modèles. Le premier est une approximation du modèle Eulérien pour le transport branché par un modèle de type phase-field avec divergence prescrite. Nous montrons comment une estimation uniforme de l’énergie, en fonction de la contrainte sur la divergence, permet d’établir un résultat de Gamma-convergence. Le second modèle, en lien avec la théorie du micromagnétisme, concerne des énergies de type Aviles-Giga dans un cadre vectoriel avec contrainte de divergence. Nous illustrerons dans quelle mesure la méthode d’entropie permet de caractériser les minimiseurs globaux. Dans certaines situations nous montrerons une conjecture de type De Giorgi concernant la symétrie 1D des minimiseurs globaux de l’énergie sous une contrainte au bord. / This thesis is devoted to the study of phase-field type variational models with divergence constraint. These models typically involve an energy depending on a parameter which represents a negligible physical quantity or is linked to some numerical approximation method for instance. A central question concerns the asymptotic behavior of these energies and of their global or local minimizers when this parameter goes to 0. We present different strategies which allow to take the divergence constraint into account. They will be illustrated in two models. The first one is a phase-field type approximation, involving a divergence constraint, of the Eulerian model for branched transportation. We illustrate how uniform estimates on the energy, depending on the constraint on the divergence, allow to establish a Gamma-convergence result. The second model, related to micromagnetics, concerns Aviles-Giga type energies for divergence-free vector fields. We use the entropy method in order to characterize global minimizers. In some situations, we will prove a De Giorgi type conjecture concerning the one-dimensional symmetry of global minimizers under boundary conditions.
167

Vanishing Act

Pryor, Caitlin 05 1900 (has links)
This dissertation is comprised of a collection of poems preceded by a critical preface. The preface reconsiders the value of discontinuous poetic forms and advocates a return to lyric as an antidote to the toxic aspects of what Tony Hoagland terms “the skittery poem of our moment.” I consider poems by Wendy Xu, Kevin Prufer, Sharon Olds, and Stephen Dunn in depth to facilitate a discussion about the value of a more centrist position between the poles of supreme discontinuity and totalizing continuity. Though poets working in discontinuous forms are rightly skeptical of the hierarchies that govern narrative and linear forms, as Czesław Miłosz notes in The Witness of Poetry, “a poet discovers a secret, namely that he can be faithful to real things only by arranging them hierarchically.” In my own poems, I make use of the hierarchies of ordered perception in lyric and narrative forms to faithfully illuminate the collapsed structures of my own family history in the shadow of Detroit. I practice the principles I advocate in the preface, using a continuous form to address fractured realities in a busy, disordered age when poets often seek forms as fragmented as their perceptions. These poems are distinctly American, but because there is no true royalty in America, our great cultural and economic institutions—television, music, film, magazines, and big business—take the place of the castle (the book’s emblem) while Michael Jackson ultimately rises as the commanding dead king whose passing prompts contemplation of the viability of popular culture, family, history, and geography. The fallen structures that litter the work are many: the twin towers, chess rooks, bounce castles, nuclear families, the auto industry. However, the sole structure cohering the whole is that of a lyric voice whose authority is derived through lived experience and presented in rich, continuous poetic forms.
168

Metody pro analýzu vlastností přenosových vedení / Methods for properties analysis of transmission lines

Žůrek, Dalibor January 2012 (has links)
This work focuses on a search of available literature on the theory of transmission lines and verify the possibility of simulation processes on these lines using a suitable simulation program. Initially, for the introduction to the parameters and the phenomenon that characterize the line and are important for understanding the issue. These parameters are then measured and compared with traces from the simulation in program PSpice. In another part of the work, the reader is familiar with the basics of reflectometry and fault detection capabilities on transmission lines with the basic reflectometry methods TDR and FDR, as well as with other methods of OTDR, MSR, and PD-FDR. For the TDR, FDR and MSR methods were made experimental measurements with a view to determining the position of the various types of faults on the tested leadership.
169

Why do local institutions matter? The political economy of decentralization

Colombo, Andrea 10 May 2019 (has links) (PDF)
In the past decades, decentralization has become increasingly important in both developing and developed countries. Based on the standard decentralization theorem, policy makers believe that local governments are closer to citizens and know more about local contexts and needs than the national governments. Consequently, they can design policies leading to a more efficient allocation of public goods. Moreover, when accompanied by empowerment of local decision-makers, decentralization is supposed to make local politicians more accountable to voters in a way that national politicians are not. Yet, the effective implementation of decentralization policies may heavily rely on local institutions. This thesis contributes to a rising literature analyzing the political economics of decentralization, that is the extent to which local political dynamics may reinforce or jeopardies decentralization reforms, ultimately affecting the citizens' well-being. I consider three countries that have devolved power to local politicians to a different extent, and tackle three obstacles that may undermine the beneficial effects of decentralization reforms: first, strong political competition at the local level; second, the need for coordinating the provision of a local public good; the interaction between political competition and coordination needs on accountability and eventually the quality of a local public good. Political competition may hinder the beneficial effects of decentralization on stability in a post-war country like Burundi. After a long-lasting and devastating civil war, in 2010 Burundi organized the first local elections, with the hope of establishing political stability through democratic means. However, together with two co-authors, I show that such political decentralization partly failed. We use a unique dataset and geographic fixed effects to show that violence was higher in municipalities characterized by fierce political competition and acute polarization between demobilized rebel groups. The former protagonists of the civil war used the elections as another stage to engage in a stiff struggle for power, and used “specialists of violence” to illicitly steer the electoral outcome.Political dynamics may undermine the coordinated management of the local sewerage networks in Brazil. I use geospatial data to proxy for the scope of coordination between neighboring municipalities: municipalities that are close “enough” are those more exposed to the spreading of water-borne diseases, which ultimately justifies cross-boundary coordination of local sanitation networks. By exploiting a Regression Discontinuity Design in close municipal elections, I show that political alignment between neighboring mayors may lead to lower access to sanitation networks of households. I argue that mayors co-managing a public good have a stronger incentive to monitor each other and ensure effective coordination when they come from different political parties, essentially because of political competition. Mayors from the same party would tend instead to be more lenient to each other, ultimately undermining the quality of the local public good co-provided.Finally, I study the effect of decentralization on the accountability of local politicians co-managing local police in Belgium. In 2005, one of the regions of Belgium introduced the direct election of mayors, while in the rest of the country mayors remained appointed by the local city councils. Together with a co-author, I exploit this reform to show that crime incidence in municipalities affected by the reform decreased faster than anywhere else in the country. We argue that the direct election of mayors increase the accountability of mayors and their incentives to fight criminality. However, we find that the effects of the reform decrease when an increasingly larger number of neighboring mayors has to coordinate the local police. The need to coordinate the local police blur accountability, mitigating the effects of the reform. To conclude, the overarching message of the thesis is that local institutions matter for the implementation of decentralization policies. Policy-makers redesigning the distribution of power between levels of government need to take into account pre-existing political and institutional dynamics that could jeopardize their policy initiatives. In particular, policy-makers could envision decentralization “at different speeds”, enabling local actors to identify objectives of development together with the right tools to pursue them, and finally decentralize accordingly. / Doctorat en Sciences économiques et de gestion / info:eu-repo/semantics/nonPublished
170

Violence begets violence? : A quantitative analysis of humanitarian military interventions’ effect on human rights violations between 1981-2011

Kelbel, Max January 2022 (has links)
This study explores the effects humanitarian interventions have on the human right status in a country. The theoretical standpoint is based on the notion that a perceived lack of accountability and repercussions for crimes committed will function as motivation for local actors to continue the human right violations, or even increase their efforts. Therefore, the working hypothesis of the study is notion that the human right violations will increase because of the presence of a humanitarian intervention. Through the use of the Cingranelli-Richards dataset, an internationally recognized source of quantitative data for human right indicators between 1981 and 2011, an indication on the effect of humanitarian interventions is provided. This is done through a method referred to as Regression Discontinuity Design (RDD), commonly used to measure the effect of a specific treatment. The results indicate that the prevalence of physical violations, such as torture and extrajudicial killings, decrease because of the intervention. However, the freedom of freely moving in and out of the country deteriorates following an intervention. The other human rights indicators proved not to be statistically significant meaning that no relationship could be determined. All in all, contrary to the theoretical narrative the assumed lack of repercussions did not provide enough incentive for further increasing human right violations. However, the practical implementations of the results are positive. Because no confirmed relationship apart from in the case of physical rights was proven it means that humanitarian interventions avoid facing a severe argument to cancel the concept which a confirmed relationship would have meant.

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