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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
151

Financial compensation : when is it effective in restoring trust after double deviation?

Ubal, Valentina Ortiz January 2017 (has links)
Situações nas quais a compensação financeira pode ser eficaz na recuperação da confiança após o duplo desvio têm sido negligenciadas pela literatura de marketing. O objetivo principal desta dissertação foi identificar situações em que a compensação financeira imediata é mais eficaz do que táticas de recuperação não financeiras (i.e. pedido de desculpas, promessa de não ocorrência de mesma falha no futuro) na restauração da confiança após o duplo desvio. Especificamente, visou examinar a moderação do tipo de violação (se financeira ou não) no efeito de diferentes táticas de recuperação (i.e. pedido de desculpas, promessa de não ocorrência de mesma falha no futuro e compensação financeira) sobre a recuperação da confiança após o duplo desvio; e investigar a mediação das atribuições no efeito da compensação financeira sobre a recuperação da confiança após o duplo desvio. Os resultados encontrados através de dois estudos experimentais realizados com diferentes populações e contextos de serviços indicam que a compensação imediata é mais eficaz do que o pedido de desculpas e a promessa na recuperação da confiança após o desvio duplo somente quando a falha inicial implicou em perda financeira para o cliente. Quando a falha inicial não gera perdas monetárias, todas as três táticas possuem efeitos similares. Além disso, verificou-se que a atribuição de benevolência explica ao menos parte do efeito da compensação monetária sobre a recuperação da confiança na situação de falha monetária. / Situations in which financial compensation may be effective to rebuild trust after a double deviation have been neglected by the marketing literature. The main objective of this thesis was to identify situations in which immediate financial compensation is more effective than non-financial recovery tactics (i.e., apology, promise that the failure will not repeat in the future) in trust restoration after double deviation. It specially aimed to examine the moderation of the type of failure (whether financial or not) in the effect of different recovery tactics (ie apology, promise, and financial compensation) on trust recovery after double deviation; and investigate the mediation of attributions in the effect of financial compensation on trust recovering after the double deviation. The results found, through two experimental studies conducted with different populations and service contexts, indicate that immediate compensation is more effective than apology and promise to repair trust after double deviation only when the initial failure causes a financial loss for the client. When the initial failure does not refer to monetary losses, all three tactics had similar effects. In addition, it has been found that the attribution of benevolence explains at least part of the effect of monetary compensation on trust recovery in the situation of monetary failure.
152

Measurements of the CKM angle γ at the LHCb experiment

Cheung, Shu-Faye January 2016 (has links)
Two measurements of the Cabibbo-Kobayashi-Maskawa angle &gamma; using B &rarr; DK and B<sup>0</sup> &rarr; DK<sup>&ast;0</sup> decays are presented in this thesis. The subsequent D meson decays to the K<sub>S</sub><sup>0</sup>&pi;<sup>+</sup>&pi;<sup>−</sup> and K<sub>S</sub><sup>0</sup>K<sup>+</sup>K<sup>−</sup> final states are studied using a binned Dalitz plot analysis. The D strong-phase variation over the Dalitz plot is taken from measurements performed at the CLEO-c experiment, making the analysis independent of a model to describe the D decay amplitude. Both measurements are performed using proton-proton collision data collected by the Large Hadron Collider beauty (LHCb) experiment in 2011 and 2012, corresponding to an integrated luminosity of 3 fb<sup>−1</sup> at centre-of-mass energies &radic;s = 7 TeV and 8 TeV. The value &gamma;= (62 <sup>+15</sup><sub style='position: relative; left: -1.7em;'>−14</sub>)° is measured using B<sup>0</sup> &rarr; DK<sup>&ast;0</sup> decays and &gamma; = (71 ± 20)° is measured using B<sup>0</sup> &rarr; DK<sup>&ast;0</sup> decays, with a second solution for each value corresponding to &gamma; + 180°. The measurements are consistent with the world average value of &gamma;.
153

Flavour studies with LHCb : b-meson mixing, lepton-flavour violation and the velo upgrade

Bird, Thomas January 2016 (has links)
Semileptonic B decays of the type Bq⁰→Dq⁻μ⁺ν (where Dq⁻→K⁻K⁺pie⁻) are selected and their lifetimes are corrected using a statistical simulation-based correction called the k-factor. Using 1 fb⁻¹ of LHCb data the B⁰ and Bs⁰ mixing frequencies are measured to be Deltamd = ( 0.503 ± 0.011 (stat) ± 0.013 (syst) ) ps⁻¹ and Deltams = ( 17.93 ± 0.22 (stat) ± 0.15 (syst) ) ps⁻¹. We exclude the null hypothesis of no mixing for the B⁰ and Bs⁰ by 5.8 and 13.0 standard deviations respectively. This is the first observation of Bs Bsbar mixing using only semileptonic B decays. The lepton flavour violating decay D⁰→eμ is searched for, using tagged D⁰ decays from D*→D⁰pie, and the measurement is normalised using D⁰→K⁻pie⁺ decays. No evidence is seen of an excess over the expected background and so a limit is placed B(D⁰→eμ) < 1.3×10⁻⁸ at a 90% confidence level using 3 fb⁻¹ of LHCb data. This improves the previous measurement by a factor of 20 and is the world's best measurement. Possible upgrades to the LHCb VELO detector are simulated and aspects of the upgraded detector are optimised to ensure that all tracks within the angular acceptance can be detected with high precision. Finally the simulated performance of the current and upgraded VELO detectors are compared.
154

As violaÃÃes de direitos de crianÃas e adolescentes praticadas no Ãmbito familiar / Violations of the rights of children and adolescents practiced within the family

Karina dos Santos Oliveira 19 July 2017 (has links)
Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / Esta dissertaÃÃo tem por proposta lanÃar um olhar para as prÃticas de violaÃÃes de direitos de crianÃas e adolescentes cometidos no Ãmbito domÃstico da famÃlia, ou seja, para as formas de violÃncia no qual estejam envolvidos algum familiar direto ou indireto da vÃtima. Assim, a partir de uma reflexÃo teÃrica em torno do que podemos considerar como sendo do campo da Sociologia da FamÃlia e da Sociologia da ViolÃncia, o estudo buscou primeiramente compreender como esta instituiÃÃo, no caso a famÃlia, que ocupa um lugar simbÃlico relevante na sociedade e sobre o qual se cria todo um imaginÃrio social baseado em estereÃtipos como de âproteÃÃoâ, âcuidadoâ, âreduto de valores morais e afetivosâ, acaba se configurando ao mesmo tempo como um espaÃo para a ocorrÃncia de prÃticas de agressÃo. Para a realizaÃÃo da pesquisa foram tomadas para a investigaÃÃo as ocorrÃncias notificadas junto ao Conselho Tutelar de Paracuru-Ce. Houve o atrelamento entre metodologia qualitativa e quantitativa. Dentre as tÃcnicas utilizadas, cita-se: observaÃÃo participante, diÃrio de campo, entrevistas informais e anÃlise documental. Por meio de um levantamento estatÃstico dos casos, atravÃs do Software Sphinx (ferramenta para anÃlise de dados quantitativos e qualitativos), trabalhou-se o cruzamento entre variÃveis como: tipo de violaÃÃo, acusado, denunciante, forma de denÃncia, sexo e faixa etÃria das vÃtimas etc. No total foram analisadas 3.741 ocorrÃncias. De modo geral, como resultado, verificou-se que as violaÃÃes mais incidentes foram: negligÃncia, violÃncia fÃsica, exploraÃÃo de trabalho infantil e violÃncia sexual. Dentre os principais acusados do ambiente familiar encontram-se: os pais (casal), mÃe, pai, avÃs, padrasto, madrasta, tios e irmÃos da vÃtima. No que diz respeito aos denunciantes, foi importante perceber que mesmo a famÃlia ocupando o lugar como âvioladoraâ de direitos, esta apareceu como a grande denunciadora dos casos. Destaca-se, ainda, que o meio mais usual de realizaÃÃo da denÃncia foi a forma presencial, onde o declarante se dispÃe ao ir atà o ÃrgÃo registrar a ocorrÃncia. Em relaÃÃo Ãs vÃtimas, o pÃblico masculino foi o grupo social mais atingido, embora tenha uma representaÃÃo quantitativa bem prÃxima ao pÃblico feminino. Referente a faixa etÃria dos mesmos, o Ãndice de ocorrÃncias com crianÃas se sobressaiu se comparado aos adolescentes. / This dissertation aims to propose an examination ondomestic-based practices of children and adolescents rights violation, i.e. forms of violence in which a direct or indirect victimâs family member is involved. Thus, based on a theoretical reflection on what we can consider as being in the field of Sociology of the Family as well as the Sociology of Violence, the study sought firstly to understand how this institution, i.e. the family, which occupies a relevant symbolic position in society and on which an entire social imaginary based on stereotypes such as "protection", "care", "redoubt of moral and affective values", ends up as a space where aggression practices occur. For the research accomplishment, the occurrences notified to the Paracuru-Ce Tutelary Council were investigated. There was a link between qualitative and quantitative methodology. Among the techniques used are: participant observation, field diary, informal interviews and documentary analysis. The statistical analysis was performed through the Sphinx Software (a tool for quantitative and qualitative data analysis) in order to cross-check variables such as: type of violation, accused ones, whistleblower, complaint form, gender and age group of victims etc. A total of 3,741 occurrences were analyzed. In general, the results demonstrated that the most frequent violations were: negligence, physical violence, child laborexploitation and sexual violence. Among the main accused based on the family environment there are: parents (couple), mother, father, grandparents, stepfather, stepmother, uncles and brothers of the victim. Regarding whistle blowers, it was important to realize that even a family occupying the place as a "violator" of rights,it emerged as the main whistleblower in such cases. It is also highlighted that the most usual mean of performing the complaint is the face-to-face denunciation, i.e. the declarant is willing to go to the responsible organ in order to record the occurrence. Regarding the victims, the male audience was the most affected social group, although it has a quantitative representation very close to the female one. Regarding their age group, the index of occurrences with children stood out compared to the adolescents.
155

Monopolos e dyons em teorias de calibre não Abelianas com quebra da simetria de Lorentz: O caso do grupo SO(3) / Monopoles and dyons in non-Abelian gauge theories with a breakdown of Lorentz symmetry: The case of the SO (3)

DIAS, Marcos Lima 13 April 2017 (has links)
Submitted by Rosivalda Pereira (mrs.pereira@ufma.br) on 2017-11-06T20:00:02Z No. of bitstreams: 1 Marcos Lima Dias.pdf: 1365744 bytes, checksum: 2aa8dc442d4e20438c570810fb9d2ab8 (MD5) / Made available in DSpace on 2017-11-06T20:00:02Z (GMT). No. of bitstreams: 1 Marcos Lima Dias.pdf: 1365744 bytes, checksum: 2aa8dc442d4e20438c570810fb9d2ab8 (MD5) Previous issue date: 2017-04-13 / CAPES / The theoretical study about the existence of magnetic monopole has begun by P. A. M. Dirac in 1931 and its main consequence has been the possibility of explaining the quantization of the electric charge. In Grand Uni cation Theories (GUT's), the magnetic monopole may appear as a topological defect by spontaneous symmetry break, in a process known as Higgs mechanism. The GUT's also predict the existence of a topological soliton which has both magnetic and electric charges: the so-called dyon. Theoretically, these particles are predicted very massive and abundant in the Universe. There are particular cases of monopole and dyon, called BPS's states, which have the smallest possible mass values, besides analytical solutions. In this work, we present some basic ideas about topology and homotopy; we describe the main points that have led to the development of the theoretical study of monopole and dyon both as topological solitons; and nally we investigate the e ects of the Lorentz-violating CPTeven terms in the Gauge (in particular, non birefringent one) and Higgs sectors on the BPS's states of the 't Hooft-Polyakov magnetic monopole and of the Julia-Zee dyon, both given in the Georgi-Glashow SO(3) model. / O estudo teórico a respeito da existência do monopolo magnético foi iniciado por P. A. M. Dirac em 1931 e teve como principal consequência a possibilidade de explicar a quantização da carga elétrica. Em Teorias de Grande Unificação (GUT's), o monopolo magnético pode surgir como um defeito topológico por meio da quebra espontânea de simetria, em um processo conhecido como mecanismo de Higgs. As GUT's preveem também a existência de um sóliton topológico que possui tanto carga magnética quanto elétrica: o chamado dyon. Teoricamente, essas partículas se apresentam muito massivas e abundantes no Universo. Hé casos particulares do monopolo e do dyon, denominados estados BPS's, que têm os menores valores possíveis de massa, cujas soluções são analíticas. Neste trabalho, apresentamos algumas ideias básicas acerca de topologia e homotopia; descrevemos os principais pontos que levaram ao desenvolvimento do estudo teórico do monopolo e do dyon como sólitons topológicos; e investigamos finalmente os efeitos dos termos CPTpares de violação da simetria de Lorentz nos setores de Gauge (em especial, n~ao birrefrigente) e de Higgs sobre os estados BPS's do monopolo magnético de't Hooft-Polyakov e do dyon de Julia-Zee, ambos dados no modelo SO (3) de Georgi-Glashow.
156

Modelos seesaw a baixas energias e modelo de violação mínima de sabor no modelo seesaw tipo III / Low energy of seesaw models and minimal flavour violation in type III seesaw

Escobar, Lindber Ivan Salas 10 October 2012 (has links)
Enquanto todos os modelos com neutrinos massivos de Majorana levam ao mesmo operador efetivo de dimensão d = 5, que não conserva número leptônico, os operadores de dimensão d = 6, obtidos a baixas energias, conservam número leptônico e são diferentes dependendo do modelo de alta energia da nova física. Derivamos os operadores de dimensão d = 6 que são característicos de modelos Seesaw genéricos, no qual a massa do neutrino resulta do intercâmbio de campos pesados que podem ser tanto singletos fermiônicos, tripletos fermiônicos ou tripletos escalares. Os operadores resultantes podem conduzir a efeitos observáveis no futuro próximo, se os coeficientes dos operadores de dimensão d = 5 e d = 6 são desacoplados. Neste trabalho apresentamos o modelo violação mínima de sabor no contexto do modelo seesaw tipo III, no qual é possível obter tal desacoplamento. Isto permite reconstruir a estrutura de sabor a partir dos valores das massas dos neutrino leves e dos parâmetros de mistura, mesmo na presença de fases de violação CP. / While all models of Majorana neutrino masses lead to the same dimension five effective operator, which does not conserve lepton number, the dimension six operators induced at low energies conserve lepton number and differ depending on the high energy model of new physics. We derive the low-energy dimension six operators which are characteristic of generic Seesaw models, in which neutrino masses result from the exchange of heavy fields which may be either fermionic singlets, fermionic triplets or scalar triplets. The resulting operators may lead to effects observable in the near future, if the coefficients of the dimension five and six operators are decoupled. In this work we present the model of minimal avor violation in the context of the type III seesaw model, in which it is possible to obtain the decoupling mentioned before. This allows to reconstruct the avour structure of the model from the values of the light neutrino masses and mixing parameters, even in the presence of CP-violating phases.
157

Error Related Negativity in Parkinson’s Disease: A Test of the Validity of MesencephalicDopamine Contributions to ERN

Siders, Craig A 01 June 2008 (has links)
A model proposed by Holroyd and Coles (2002) stating that error related negativity (ERN) is caused by a decrease in mesencephalic dopamine output to the ACC was tested. A group of individuals with Parkinson's disease (N = 16) and an age and education matched group free from neurological disorder (N = 16) completed a card guessing task where the magnitude of monetary penalties and rewards for incorrect and correct answers was varied by block. Individuals with Parkinson's disease were tested after an overnight washout from dopamingeric medications. The amplitude of the mid-frontal negativity elicited by feedback was analyzed with spatial and temporal principal components analyses. Dipole source analyses were also performed. Analyses revealed no significant differences in the mid-frontal negativity amplitude between the two groups. In addition, the magnitude of consequence and the validity of response had no significant effects on fERN amplitude although there was a trend for higher magnitude consequences to be associated with larger fERN amplitude. Dipole analyses indicated the source of the mid-frontal negativity fell into the cingulate, specifically the cingulate gyrus. The results suggest that the mid-frontal negativity elicited by feedback indicating an error was made remains intact in individuals with Parkinson's disease. This does not support predictions made by Holroyd and Coles' model in regard to this group unless disruptions to the system that produces the fERN do not occur until later stages in the disease. An additional finding was a late positive potential for the error trials which began approximately 450 milliseconds after feedback and continued throughout the epoch. The ramifications of this wave are discussed.
158

Étude de la violation de symétrie CP à l'aide du canal de désintégration B0->rho0rho0 dans l'expérience BaBar

Estève, Loïc 29 September 2008 (has links) (PDF)
La mesure des paramètres de violation de CP dans les désintégrations du type b->uubard permet en principe d'avoir accès à sin(2alpha), où alpha est l'un des angles du triangle d'unitarité. Cependant, la présence de diagrammes à boucle, appelées diagrammes pingouins, complique l'interprétation de la mesure expérimentale, qui ne donne en fait accès qu'à une valeur effective de \alpha : æff. Les mesures dans le canal B0->rho0rho0 permettent de réaliser pour la première fois une analyse d'isospin complète dans les modes B->rhorho, et donc en principe de déterminer le décalage \alpha-æff induit par les diagrammes pingouins. La désintégration B0->rho0rho0 a été étudiée en utilisant l'échantillon final de BABAR, soit $465 10^6$ désintégrations $\Y4S\to\BB$, collectées auprès du collisionneur \epem asymétrique PEP-II. Le rapport d'embranchement du mode B0->rho0rho0 a été mesuré BR=0.92±0.32±0.14 10^{-6} ainsi que la fraction de polarisation longitudinale fL= 0.75+0.11-0.14±0.03. La signifiance du signal B0->rho0rho0 est de 3.1 \sigma en prenant en compte les erreurs systématiques. La dépendance temporelle de la composante longitudinale a été étudiée et les paramètres de violation CP ont également été mesurés: S^{00}_L = 0.3±0.7±0.2, C^{00}_L = 0.2±0.8±0.2. L'implication de ces résultats sur l'angle $\alpha$ du triangle d'unitarité a été étudiée en effectuant une analyse d'isospin. En utilisant les mesures de BABAR pour les modes B->rho+rho- et B±->rho±rho0, la limite supérieure à 68% (90%) sur le décalage induit par la présence de diagrammes pingouins est donnée par: |\alpha-æff|<15.6° (<17.6°)
159

Time-Dependent Amplitude Analysis of B^0->Kspi+pi- decays with the BaBar Experiment and constraints on the CKM matrix using the B->K*pi and B->rho K modes

Pérez Pérez, Luis Alejandro 09 December 2008 (has links) (PDF)
Une analyse en amplitudes dépendantes du temps des désintégrations $B^0 \to K^0_S\pi^+\pi^-$ est effectuée afin de mesurer les paramètres de violation de CP des modes $f_0(980)K_S^0$ et $\rho^0(770)K_S^0$, ainsi que l'asymétrie directe de CP pour $K^*(892)^\pm\pi^\mp$. Les résultats sont obtenus à partid d'un échantillon de $(383\pm 3)\times10^{6}$ paires $B\bar{B}$, enregistrées par le détecteur \babar\ auprès du collisionneur asymétrique PEPII au SLAC. Deux solutions sont trouvées, avec des figures de mérite équivalentes sur la qualité de l'ajustement. En incluant les incertitudes systématiques et provenant du modèle de Dalitz utilisé, l'intervalle de confiance combiné sur $\beta_{\rm eff}$ dans le mode $f_0(980)K_S^0$ est $18^\circ< \beta_{\rm eff}<76^\circ$ (à $95\%$ C.L.) ; la conservation de CP dans ce mode est exclue à $3.5$ écarts standard. Pour le mode $\rho^0(770)K_S^0$, l'intervalle de confiance combiné est est $-9^\circ< \beta_{\rm eff}<57^\circ$ (à $95\%$ C.L.). Pour le mode $K^*(892)^\pm\pi^\mp$, le paramètre d'asymétrie directe de CP est $A_{\rm CP}=-0.20 \pm 0.10\pm 0.01\pm 0.02$. La mesure de la phase relative entre les amplitudes de désintégration $B^0\to K^*(892)^+\pi^-$ et $\bar{B}^0\to K^*(892)^-\pi^+$ exclut l'intervalle $[-132^\circ : +25^\circ]$ (à $95\%$ C.L.). Les rapports d'embranchement et les asymétries directes de CP sont mesurées pour tous les modes résonants intermédiaires significatifs. Les mesures obtenues dans les modes $\rho^0(770) K^0_S$ et $K^{*\pm}(892)\pi^{\mp}$ sont utilisées comme paramètres d'entrée dans une analyse phénoménologique des désintégrations $B \to K^*\pi$ et $B \to \rho K$, basée uniquement sur la symétrie d'isospin $SU(2)$. L'ajout d'informations extérieures sur la matrice CKM permet de poser des contraintes sur l'espace des paramètres hadroniques. Pour $B \to K^*\pi$, les intervalles obtenus sur les pingouins électrofaibles ne sont que marginalement en accord avec les attentes théoriques. Les contraintes sur la matrice CKM sont dominées par des incertitudes d'origine théorique. Une étude de prospective, utilisant les améliorations attendues sur les mesures de ces modes à LHCb, ou dans les programmes futurs tels que Super-B ou Belle-upgrade, permet d'illustrer le potentiel de physique de cette approche.
160

Phénoménologie d'annihilation de matière noire et de violation non-minimale de la saveur dans le MSSM

Herrmann, Björn 10 September 2008 (has links) (PDF)
En l'absence d'évidence expérimentale directe de superpartenaires, il est essentiel de contraindre l'espace des paramètres du Modèle Standard Supersymétrique Minimal (MSSM) aux échelles de la brisure de la Supersymétrie et électrofaible. <br />Après une brève introduction à la Supersymétrie (SUSY), nous présentons une analyse extensive des contraintes électrofaible, de basse énergie et cosmologiques dans des modèles de supergravité minimale (mSUGRA) et de brisure de Supersymétrie par médiation de jauge (GMSB). Nous incluons la possibilité de violation non-minimale de la saveur (NMFV) et définissons des scénarios ``benchmark'' basés sur des ``scans'' détaillés de l'espace des paramètres. <br />Ensuite, nous considérons l'annihilation d'une paire de neutralinos en une paire de quark-antiquark qui domine dans de larges régions de l'espace des paramètres dans les modèles mSUGRA. Nous présentons le calcul complet incluant des corrections à une boucle en QCD et SUSY-QCD de ces processus et montrons numériquement que les diagrammes à une boucle ont un impact non négligeable sur la section efficace d'annihilation. En conséquence, la prédiction de densité relique de matière noire reçoit des corrections importantes, ce qui résulte en une modification de la région cosmologiquement favorisée dans l'espace des paramètres.<br />Finalement, nous présentons des expressions analytiques et des prédictions numériques pour des sections efficaces de production de squarks, jauginos et gravitinos au LHC dans les modèles GMSB avec NMFV. Nous discutons également la phénoménologie du mélange de saveur et les implications cosmologiques sur la masse du gravitino dans ce contexte.

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