• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 49
  • 8
  • 5
  • 4
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 89
  • 89
  • 23
  • 17
  • 13
  • 12
  • 9
  • 9
  • 7
  • 7
  • 7
  • 6
  • 6
  • 6
  • 6
  • 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.
71

ENTREPRENEURIAL VENTURE FAILURE EXPERIENCES : AN ANALYSIS INTO CAUSES, COSTS, ANDOUTCOMES OF VENTURE FAILURE / Företagande misslyckande erfarenheter : En analys i orsaker, kostnader och resultat av företagets misslyckande

PIADEHBASMENJ, AMIRALI January 2016 (has links)
Forskning om entreprenörskap fokuserar på framgång som ignorerar den höga felfrekvensen av Nya företag. Många nya företag misslyckas så hur entreprenörer hantera det när deras företag misslyckas? Framgångsrika entreprenörer prisar fördelarna med misslyckande som en värdefull lärare. Resultatet av misslyckande regelbundet fylld med ekonomiska, sociala, psykologiska och fysiska hälsoproblem. Syftet med denna forskning är att bedöma företagets misslyckande upplevelser för företagare, från det ögonblick resultatet genom att  återhämtningen för att hantera företagande fel och avsluta för påverkan av den slutna företag.  I denna forskning aspekter av livet som påverka av entreprenörs fel undersöka ekonomiskt, socialt och psykologiskt att belysa faktorer som kan påverka mängden av kostnaderna för ett misslyckande. Därefter beskriver forskningen hur entreprenörer lära av misslyckanden. Den presenterar på resultaten av företagets misslyckande, inklusive hantera fel och återhämtning tillsammans med kognitiva och beteendemässiga utfall. / Research on entrepreneurship focuses on success which ignores the high failure rate of new ventures. Many new ventures fail so how entrepreneurs deal with it when their venture    fails? Successful entrepreneurs praising the advantages of failure as a valuable teacher. The result of failure is regularly filled with economic, social, psychological, and physical health disorder. The aim of this research is to assessment venture failure experiences for entrepreneurs, from the instant result through to recovery for coping with entrepreneurial failure and exit for impact of the closed venture. In this research, aspects of life affected by entrepreneurial failure examine economically, socially and psychologically in highlighting factors that may influence the amount of costs of failure. Next, the research describes how entrepreneurs learn from failure. It presents on the outcomes of venture failure, including coping with failure and recovery together with cognitive and behavioral outcomes. The main objective of the research study is to understand the failure from entrepreneurs    who have experienced it and also to make a theoretical framework of failure based on entrepreneurial venture failure experiences. Every entrepreneur starts up a venture with high expectations of achieving success. Failure can be emotionally disturbing, devastating,  painful, distressing and costly for the entrepreneur who may have to aspect the stigma of failure and the loss of reputation. The entrepreneur can get involved in grief, heartache, anxiety, depression, shame, rejection and discouragement (Politis & Gabrielsson, 2009). The purpose of the research is to investigate how entrepreneurs realize and react to venture  failure. Moreover, entrepreneurs are looking for positive aspects of failure as enhancing experiences that help their coping with entrepreneurial failure, learning from failure, the willingness to begin a new venture and also trigger changes in upcoming decision-making. The purpose of the research is to take a view of the existed experience of failure, taking into consideration impact from the entrepreneurship.
72

Processus de construction identitaire de jeunes adultes en situation de pauvreté dans un contexte de raccrochage scolaire : voies d'émancipation?

Charlebois, François-Xavier 02 1900 (has links)
No description available.
73

Numerical tools for the large eddy simulation of incompressible turbulent flows and application to flows over re-entry capsules/Outils numériques pour la simulation des grandes échelles d'écoulements incompressibles turbulents et application aux écoulements autour de capsules de rentrée

Rasquin, Michel 29 April 2010 (has links)
The context of this thesis is the numerical simulation of turbulent flows at moderate Reynolds numbers and the improvement of the capabilities of an in-house 3D unsteady and incompressible flow solver called SFELES to simulate such flows. In addition to this abstract, this thesis includes five other chapters. The second chapter of this thesis presents the numerical methods implemented in the two CFD solvers used as part of this work, namely SFELES and PHASTA. The third chapter concentrates on the implementation of a new library called FlexMG. This library allows the use of various types of iterative solvers preconditioned by algebraic multigrid methods, which require much less memory to solve linear systems than a direct sparse LU solver available in SFELES. Multigrid is an iterative procedure that relies on a series of increasingly coarser approximations of the original 'fine' problem. The underlying concept is the following: low wavenumber errors on fine grids become high wavenumber errors on coarser levels, which can be effectively removed by applying fixed-point methods on coarser levels. Two families of algebraic multigrid preconditioners have been implemented in FlexMG, namely smooth aggregation-type and non-nested finite element-type. Unlike pure gridless multigrid, both of these families use the information contained in the initial fine mesh. A hierarchy of coarse meshes is also needed for the non-nested finite element-type multigrid so that our approaches can be considered as hybrid. Our aggregation-type multigrid is smoothed with either a constant or a linear least square fitting function, whereas the non-nested finite element-type multigrid is already smooth by construction. All these multigrid preconditioners are tested as stand-alone solvers or coupled with a GMRES (Generalized Minimal RESidual) method. After analyzing the accuracy of the solutions obtained with our solvers on a typical test case in fluid mechanics (unsteady flow past a circular cylinder at low Reynolds number), their performance in terms of convergence rate, computational speed and memory consumption is compared with the performance of a direct sparse LU solver as a reference. Finally, the importance of using smooth interpolation operators is also underlined in this work. The fourth chapter is devoted to the study of subgrid scale models for the large eddy simulation (LES) of turbulent flows. It is well known that turbulence features a cascade process by which kinetic energy is transferred from the large turbulent scales to the smaller ones. Below a certain size, the smallest structures are dissipated into heat because of the effect of the viscous term in the Navier-Stokes equations. In the classical formulation of LES models, all the resolved scales are used to model the contribution of the unresolved scales. However, most of the energy exchanges between scales are local, which means that the energy of the unresolved scales derives mainly from the energy of the small resolved scales. In this fourth chapter, constant-coefficient-based Smagorinsky and WALE models are considered under different formulations. This includes a classical version of both the Smagorinsky and WALE models and several scale-separation formulations, where the resolved velocity field is filtered in order to separate the small turbulent scales from the large ones. From this separation of turbulent scales, the strain rate tensor and/or the eddy viscosity of the subgrid scale model is computed from the small resolved scales only. One important advantage of these scale-separation models is that the dissipation they introduce through their subgrid scale stress tensor is better controlled compared to their classical version, where all the scales are taken into account without any filtering. More precisely, the filtering operator (based on a top hat filter in this work) allows the decomposition u' = u - ubar, where u is the resolved velocity field (large and small resolved scales), ubar is the filtered velocity field (large resolved scales) and u' is the small resolved scales field. At last, two variational multiscale (VMS) methods are also considered. The philosophy of the variational multiscale methods differs significantly from the philosophy of the scale-separation models. Concretely, the discrete Navier-Stokes equations have to be projected into two disjoint spaces so that a set of equations characterizes the evolution of the large resolved scales of the flow, whereas another set governs the small resolved scales. Once the Navier-Stokes equations have been projected into these two spaces associated with the large and small scales respectively, the variational multiscale method consists in adding an eddy viscosity model to the small scales equations only, leaving the large scales equations unchanged. This projection is obvious in the case of a full spectral discretization of the Navier-Stokes equations, where the evolution of the large and small scales is governed by the equations associated with the low and high wavenumber modes respectively. This projection is more complex to achieve in the context of a finite element discretization. For that purpose, two variational multiscale concepts are examined in this work. The first projector is based on the construction of aggregates, whereas the second projector relies on the implementation of hierarchical linear basis functions. In order to gain some experience in the field of LES modeling, some of the above-mentioned models were implemented first in another code called PHASTA and presented along with SFELES in the second chapter. Finally, the relevance of our models is assessed with the large eddy simulation of a fully developed turbulent channel flow at a low Reynolds number under statistical equilibrium. In addition to the analysis of the mean eddy viscosity computed for all our LES models, comparisons in terms of shear stress, root mean square velocity fluctuation and mean velocity are performed with a fully resolved direct numerical simulation as a reference. The fifth chapter of the thesis focuses on the numerical simulation of the 3D turbulent flow over a re-entry Apollo-type capsule at low speed with SFELES. The Reynolds number based on the heat shield is set to Re=10^4 and the angle of attack is set to 180º, that is the heat shield facing the free stream. Only the final stage of the flight is considered in this work, before the splashdown or the landing, so that the incompressibility hypothesis in SFELES is still valid. Two LES models are considered in this chapter, namely a classical and a scale-separation version of the WALE model. Although the capsule geometry is axisymmetric, the flow field in its wake is not and induces unsteady forces and moments acting on the capsule. The characterization of the phenomena occurring in the wake of the capsule and the determination of their main frequencies are essential to ensure the static and dynamic stability during the final stage of the flight. Visualizations by means of 3D isosurfaces and 2D slices of the Q-criterion and the vorticity field confirm the presence of a large meandering recirculation zone characterized by a low Strouhal number, that is St≈0.15. Due to the detachment of the flow at the shoulder of the capsule, a resulting annular shear layer appears. This shear layer is then affected by some Kelvin-Helmholtz instabilities and ends up rolling up, leading to the formation of vortex rings characterized by a high frequency. This vortex shedding depends on the Reynolds number so that a Strouhal number St≈3 is detected at Re=10^4. Finally, the analysis of the force and moment coefficients reveals the existence of a lateral force perpendicular to the streamwise direction in the case of the scale-separation WALE model, which suggests that the wake of the capsule may have some preferential orientations during the vortex shedding. In the case of the classical version of the WALE model, no lateral force has been observed so far so that the mean flow is thought to be still axisymmetric after 100 units of non-dimensional physical time. Finally, the last chapter of this work recalls the main conclusions drawn from the previous chapters.
74

Purification of A Serum Factor That Triggers Cell Cycle Re-entry In Differentiated Newt Myotubes / Aufreinigung eines Serumfactors, welcher den Zellzyklus-Wiedereintritt in differenzierten Salamander-Muskelzellen steuert

Straube, Werner 30 November 2006 (has links) (PDF)
In contrast to mammals, some fish and amphibians have retained the ability to regenerate complex body structures or organs, such as the limb, the tail, the eye lens or even parts of the heart. One major difference in the response to injury is the appearance of a mesenchymal growth zone or blastema in these regenerative species instead of the scarring seen in mammals. This blastema is thought to largely derive from the dedifferentiation of various functional cell types, such as skeletal muscle, skin and cartilage. In the case of multinucleated skeletal muscle fibres, cell cycle re-entry into S-phase as well as fragmentation into mononucleated progenitors is observed both in vitro and in vivo. In order to identify molecules that initiate dedifferentiation of cells at the wound site in amphibians we have established a cellular assay with a cultured newt myogenic cell line. Using this assay we have found a serum activity that stimulates cell cycle re-entry in differentiated multinucleated newt myotubes. The activity is present in serum of all mammalian species tested so far and, interestingly, thrombin proteolysis amplifies the activity from both serum and plasma. We think this serum factor provides a link between wounding and regeneration and its identification will be a key step in understanding the remarkable differences in wound healing between mammals and amphibians. In the course of this PhD thesis we have characterized the serum factor as a thermo-labile, pH- and proteinase K-sensitive, high molecular weight protein that is resistant to denaturing conditions such as SDS, urea or organic solvents. Surprisingly, under denaturing conditions the activity behaves as a low molecular weight protein that displays charge heterogeneity on isoelectric focusing. Using these characteristics of the serum factor we have performed a systematic investigation of commonly used protein chromatography modes and separation techniques to develop a successful purification procedure. After four column chromatography steps -- cation exchange, hydrophobic interaction, heparin affinity and size exclusion chromatography under denaturing conditions -- we have achieved a 2,000-fold purification starting from a commercially available Crude Bovine Thrombin preparation. This represents about 40,000-fold purification over bovine serum. Silver stained gels of the most purified fractions revealed ten major protein bands. In order to finally identify the cell cycle re-entry factor, we are currently analyzing the purification by quantitative mass spectrometry by correlating the abundance of tryptic peptides with activity in sequential fractions across a chromatography run.
75

Etude des mécanismes physiques induits pas un actionneur plasma appliqué au contrôle d’écoulements raréfiés super/hypersoniques dans le cadre de rentrées atmosphériques / Study of physical mechanisms induced by a plasma actuator for super/hypersonic rarefied flows applied to atmospheric entries

Coumar, Sandra 18 December 2017 (has links)
Ces dernières années, les missions spatiales bénéficient d'un regain d'intérêt. Cependant, lorsqu’arrive laphase d’entrée dans l’atmosphère, nous faisons encore face à d’importantes difficultés. Afin de répondre àce problème, une nouvelle technique est proposée : le contrôle par plasma pour augmenter la force detraînée sur le véhicule et ainsi, décroître sa vitesse. Dans cette thèse, un actionneur plasma est testé danstrois écoulements supersoniques (N1(M2-8Pa), N2(M4-8Pa) and N3(M4-71Pa)) et un hypersonique (M20-0.062Pa), ces écoulements étant simulés par la soufflerie MARHy.L’actionneur plasma induit des modifications de l’écoulement autour du modèle étudié, comme unemodification de la géométrie de l’onde de choc et une augmentation de l’angle de choc. Afin de mieuxcomprendre les phénomènes gouvernant ces modifications, la pression Pitot, la température surfacique etvolumique, les données électroniques et des mesures spectroscopiques ont été analysées. Les résultatsmontrèrent que deux types d’effets interviennent : thermiques (surface et volume) et l’ionisation. De plus, il aété démontré que ces effets n’ont pas la même importance suivant les conditions d’écoulements.L’actionneur plasma lui-même a été modifié dans un but d’amélioration. En particulier, deux types degénérateurs ont été étudiés pour alimenter la cathode : DC et pulsé. Finalement, il est montré que pour unepuissance de décharge de 80 W, une augmentation de 13% de la traînée et donc, une diminution de plus de25% des flux de chaleur peuvent être attendus. Par conséquent, les actionneurs plasma semblent être descandidats idéaux pour les missions spatiales et les (r)entrées atmosphérique. / Space missions are arousing renewed interest in these recent years. However, when coming to the entryinto the atmosphere, major issues are still to be considered. To answer this problem, a new Entry DescentLanding technique is proposed: plasma actuation to increase the drag force over the vehicle body and thus,decrease its speed. In this thesis, a plasma actuator is tested in three supersonic rarefied flows (N1(M2-8Pa), N2(M4-8Pa) and N3(M4-71Pa)) and a hypersonic one (M20-0.062Pa), all generated by the wind tunnelMARHy.The plasma actuator induces flow modifications over the studied model, such as a change in the shock waveshape and an increase in the shock wave angle. In order to better understand the phenomena governingthese modifications, Pitot pressure, surface and gas temperature, electron data and spectroscopicmeasurements were analyzed. The results shown that two types of effects are involved: thermal (bulk andsurface) and ionization. Moreover, it was demonstrated that these effects had not the same importancedepending on the flow conditions.The plasma actuator was also modified in order to improve it. In particular, two types of generators wereused to biase the cathode: DC and pulsed. Finally, it was shown that, for a discharge power of 80 W, a 13%increase in the drag force could be expected and thus, a decrease in the heat load over the model body ofmore than 25%. Therefore, plasma actuators seem to be promising applications for space missions andatmospheric entries.
76

Aspectos ecológicos do cervo do-pantanal Blastocerus dichotomus (Illiger, 1815) (Mammalia: cervidae): animais reintroduzidos e ou nascidos na estação ecológica de jataí, nordeste do estado de São Paulo, município de Luís Antônio

Perin, Marco Aurelio Alves 26 March 2010 (has links)
Submitted by isabela.moljf@hotmail.com (isabela.moljf@hotmail.com) on 2017-05-05T13:45:21Z No. of bitstreams: 1 marcoaurelioalvespereira.pdf: 7599008 bytes, checksum: 48e04292d562d8084f38167b184afde1 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-05-17T13:39:25Z (GMT) No. of bitstreams: 1 marcoaurelioalvespereira.pdf: 7599008 bytes, checksum: 48e04292d562d8084f38167b184afde1 (MD5) / Made available in DSpace on 2017-05-17T13:39:25Z (GMT). No. of bitstreams: 1 marcoaurelioalvespereira.pdf: 7599008 bytes, checksum: 48e04292d562d8084f38167b184afde1 (MD5) Previous issue date: 2010-03-26 / O cervo-do-pantanal (Blastocerus dichotomus) é um mamífero de grande porte, sendo considerado o maior cervídeo nativo da America do Sul. Esta espécie encontra-se extinta em 60% da sua área de distribuição histórica que compreendia as várzeas naturais dos grandes rios entre o sul do Amazonas e o norte da Argentina. Apesar de se encontrar ameaçado de extinção, pouco se sabe acerca dos aspectos ecológicos do cervo-do-pantanal. Nesse contexto, o presente estudo, busca investigar a sazonalidade no comportamento espacial desta espécie, como também analisar informações relacionadas à fidelidade de habitat e relações intra-específicas através da sobreposição de áreas núcleo. Para tanto o mesmo contém uma revisão introdutória e dois capítulos abordando os seguintes temas: 1- estudo comparativo para o efeito da sazonalidade entre animais reintroduzidos e ou nascidos na Estação Ecológica de Jataí (EEJ) e animais de população natural, localizados na bacia do rio Paraná; 2- relações espaciais através da sobreposição de áreas núcleo para animais reintroduzidos e ou nascidos na EEJ. Ao todo 39 cervos-do-pantanal marcados sendo 9 da área de reintrodução e 30 da área de população natural, contribuíram para as análises do presente trabalho. Os resultados revelam que ambas as populações estudadas tiveram áreas de vida maiores para machos do que para fêmeas, o que pode ser reflexo das diferenças nas estratégias de utilização do ambiente por indivíduos de ambos os sexos. Para os animais da EEJ as áreas estimadas para a estação chuvosa geralmente foram menores do que as estabelecidas na seca, já para os animais da bacia do rio Paraná observou-se uma inversão na ordem desses valores, ou seja, a média na estação chuvosa foi maior do que a média no período de seca. Tal inversão pode estar relacionada com a dinâmica das características ambientais promovida pela sazonalidade para cada região. A análise de fidelidade de habitat na área de reintrodução revelou uma sobreposição de suas áreas núcleos estimada para as duas estações seca e chuvosa, com fêmeas apresentando porcentagem de fidelidade maior do que machos. A análise envolvendo a sobreposição de áreas núcleo entre os animais desta região revelaram que dois animais, sendo um macho e uma fêmea, sobrepuseram seus núcleos de atividade mesmo quando estimados com concentração média harmônica (30%) de distribuição de utilização das localizações espaciais. Os dados utilizados neste trabalho fazem parte dos resultados obtidos pelo Projeto Cervo-do-Pantanal de Porto Primavera, coordenado pelo NUPECCE (Núcleo de Pesquisa e Conservação de Cervídeos), localizado na Faculdade de Ciências Agrárias e Veterinárias FCAV/UNESP de Jaboticabal, como parte das ações compensatórias referente ao reservatório formado pela usina hidrelétrica Sérgio Motta ou “Porto Primavera”. / Marsh deer (Blastocerus dichotomus) is a large mammal and is considered the largest deer native to South America, this species is extinct in 60% of its historic range that included the natural flood plain of the great rivers between the southern Amazon and northern Argentina. Despite being threatened with extinction, little is known about the ecological aspects of deer marsh. In this context, this study aims to investigate the seasonality in the spatial behavior of this species, but also analyze information related to habitat use and intraspecific relations using overlapping core areas. To this end it contains a review and two introductory chapters covering the following topics: 1 - comparative study for the seasonality effect of reintroduced animals and / or born in the Ecological Station (EEJ) and animals natural population located in the River Paraná; 2 - spatial relations using overlapping core areas to reintroduced animals and / or born in the EEJ. A total of 39 deer-billed and 9 marked the reintroduction area and 30 in the area of natural population, contributed to the analysis of this work. The results show that both populations studied areas of life were higher for males than for females, which may reflect differences in strategies for using the environment of individuals of both sexes. For animals of the EEJ areas estimated for the rainy season were generally lower than those established in the dry season, as for animals of the Paraná River basin showed a reversal in the order of these values, ie, the average during the rainy season was higher than the average during the dry season. This reversal can be related to the dynamics of environmental characteristics promoted by the seasonal pattern for each region. The analysis of habitat use of reintroduction area revealed an overlap in their core areas estimated for both dry and wet seasons, with females showing higher percentage of fidelity than males. The analysis involving the overlap of core areas among the animals of this region revealed that two animals are one male and one female overlapped its core activity even when estimated harmonic mean concentration (30%) of distribution of use of spatial locations. The data used in this work are part of the results obtained by the Project Cervo-do-Pantanal de Porto Primavera, coordinated by NUPECCE (Núcleo de Pesquisa e Conservação de Cervídeos), located at the Faculdade de Ciências Agrárias e Veterinárias FCAV/UNESP de Jaboticabal, as part stock compensation related to the reservoir formed by the Sergio Motta or "Porto Primavera Dam.
77

Characteristics of reentry women

Garces, Eleanore Lee, Russell, Judith Kay 01 January 2002 (has links)
This study looked at the potential reentry-aged women employed by the San Bernardino County Department of Children's Service. It identified the characteristics, motivations, needs and barriers of the reentry age female student. This study explored the reasons why some SBCDCS reentry-aged workers choose to further their education, while others do not.
78

Projekt na financování bytové výstavby zaměřené na lokalitu Brno / Project of Financing Flat- building Aimed at Locality Brno

Štorová, Kateřina January 2009 (has links)
The subject of this master's thesis is valuing of financial situation of company based on financial analyses. Due to results we can reccomend many variants of investment of their free finances. In the practical part of this thesis we can find optimal and profitable variant with reasons and calculations that I can reccomend to company.
79

Pathways of out-of-school youth and their re-entrance into the education training and development system or the labour market

Dube, Andile Laureth Maletsatsi 06 June 2011 (has links)
The study is an investigation into the pathways of out-of-school youth and their re-entrance into the Education Training and Development (ETD) system or the labour market. In the study the pathways of youth who dropped out of school between grades 1 and 11 are traced as they seek re-entrance to the ETD system, or entrance into the labour market. Particular attention was given to the factors that determine the choices that dropouts make either in re-entering the ETD system or entering the labour market. An analysis of the experiences of the interviewed sample of dropouts is presented. The study employs a qualitative research methodology using interviews to elicit the experiences of dropouts and school managers. The participants (young people and three school principals) were selected through snowballing from a township south of Durban. Individual and focus group interviews were held. The findings provide evidence of the value of investing in education, as suggested by the youth. This is in line with the human capital theory framework that suggests that there are major benefits to investing in education. The study is concluded by suggesting the need for second chance education in South Africa. / Thesis (PhD)--University of Pretoria, 2011. / Education Management and Policy Studies / unrestricted
80

Exploring the Effects of Ex-Prisoner Reentry on Structural Factors in Disorganized Communities: Implications for Leadership Practice

Davis, G. Michael 11 November 2014 (has links)
No description available.

Page generated in 0.0588 seconds