L'objectif de ce travail est d'anticiper l'accès à la ressource granulats au-delà des schémas actuels à long terme en France. Cette thèse, qui s'inscrit dans le cadre du projet ANR " ANTAG ", a principalement pour but la création et l'exploitation d'un système d'aide à la décision pour le marché national des granulats permettant de simuler les effets à l'échelle de 30 ans de décisions liées à l'approvisionnement des granulats et au développement de la consommation et du transport. L'approche suivie s'appuie sur un modèle de type top-down, macro-économique et il est fondé sur le principe de modélisation System Dynamics. L'apport principal est le mécanisme qui décrit l'équilibre du marché entre les sources d'approvisionnement par distribution de la surcapacité sur les sources d'approvisionnement et qui permet de modéliser et de piloter la compétition entre les acteurs. Un scénario de base, construit à partir de données historiques, sert à concevoir sept scénarios provoqués par des " actions de rupture " qui sont analysés en termes d'évolution des variables clés économiques et environnementales. La puissance du modèle réside dans sa capacité à s'enrichir de nouvelles fonctionnalités permettant d'introduire de nouveaux mécanismes secondaires.

La représentation scalable de l'information s'impose aujourd'hui pour supporter l'hétérogénéité d'un réseau interconnecté tel que l'Internet. Le codage de source adopte, pour ce faire, une approche multi-résolution pouvant délivrer progressivement à un utilisateur le contenu de sa requête. Cependant, en supposant au cours de la transmission une gestion de bout en bout des priorités ainsi établies, ces schémas restent sommairement adaptés aux environnements de pertes de paquets et de qualité de service non garantie.<br />Les codages à description multiple offrent une alternative à la transmission hiérarchisée de l'information en brisant la scalabilité de la source aux abords du canal. Dans cette thèse, nous proposons une méthode originale de description multiple qui réalise une protection différenciée de chaque niveau hiérarchique de la source en fonction des propriétés dynamiques du canal de transmission.<br />La transformation Mojette (transformation de Radon discrète exacte) est une transformation unitaire qui permet de partager un volume de données en un ensemble plus ou moins redondant de projections équivalentes. L'évolution de ce type d'opérateur initialement utilisé dans un espace continu pour la reconstruction tomographique étend le concept de support d'image à celui de mémoire tampon géométrique pour données multimédias. Ce codage à description multiple, généralisé à N canaux, autorise la reconstruction de la mémoire initiale de manière déterministe par des sous-ensembles de projections dont le nombre caractérise le niveau de protection. Ce schéma est particulièrement adapté au mode de transport par paquets sans contrôle d'intégrité extensible du canal de transmission. La hiérarchie de la source est dans ce cas communiquée sous forme transparente pour le canal via des descriptions banalisées.<br />L'évaluation du codage est effectuée en comparant les débits engendrés avec ceux d'un code MDS (Maximum Distance Separable) qui fournissent une solution optimale dans le nombre de symboles nécessaires au décodage. La relaxation des propriétés MDS dans un code (1+ε)MDS avec la transformation Mojette demande une légère augmentation de débit au profit d'une complexité réduite.<br />L'application sur des schémas de compression d'images valide concrètement l'adaptation possible des sources actuelles à un canal de type best-effort. L'utilisation dans un environnement distribué (micro-paiement, stockage distribué de données multimédia) illustre en outre un partage sécurisé de l'information.<br />En perspectives de ce travail, nous avons abordé l'intégration de cette méthode dans un protocole de transmission scalable multimédia et étudié une version probabiliste du système.

<p>The present thesis investigated family history and neurobiology of social phobia. Social phobia is a disabling disorder characterized by a marked fear of scrutiny in a variety of social situations. By using a validated questionnaire, study I related family history of excessive social anxiety to social phobia and avoidant personality disorder in epidemiologically identified probands in the Swedish general population. A two- to threefold increased relative risk of social anxiety was observed for both diagnostic groups. Thus, having an affected family member is associated with approximately a doubled risk for both social phobia and avoidant personality disorder.</p><p>The neurobiological studies explored situational and anticipatory elicited anxiety by means of positron emission tomography and 15O-water. Study II examined the functional neuroanatomy of social anxiety provocation in social phobics and a healthy comparison group during a public speaking task. Social phobia symptomatology was associated with higher neural activity in the amygdaloid complex, i.e. "the alarm system" of the brain, and lower activity in the prefrontal cortex. Study III examined the neural correlates of anxiety elicited by the anticipation of public speaking in individuals with social phobia. Anticipatory anxiety was accompanied by enhanced regional cerebral blood flow in the dorsolateral prefrontal and inferior temporal cortices as well as in the amygdaloid-hippocampal region. Brain blood flow was lower in the temporal pole and in the cerebellum. These results suggest that social phobia has a neuroanatomical basis in a highly sensitive fear network centered in the amygdaloid-hippocampal region and encompassing the prefrontal cortex.</p>

The present thesis investigated family history and neurobiology of social phobia. Social phobia is a disabling disorder characterized by a marked fear of scrutiny in a variety of social situations. By using a validated questionnaire, study I related family history of excessive social anxiety to social phobia and avoidant personality disorder in epidemiologically identified probands in the Swedish general population. A two- to threefold increased relative risk of social anxiety was observed for both diagnostic groups. Thus, having an affected family member is associated with approximately a doubled risk for both social phobia and avoidant personality disorder. The neurobiological studies explored situational and anticipatory elicited anxiety by means of positron emission tomography and 15O-water. Study II examined the functional neuroanatomy of social anxiety provocation in social phobics and a healthy comparison group during a public speaking task. Social phobia symptomatology was associated with higher neural activity in the amygdaloid complex, i.e. "the alarm system" of the brain, and lower activity in the prefrontal cortex. Study III examined the neural correlates of anxiety elicited by the anticipation of public speaking in individuals with social phobia. Anticipatory anxiety was accompanied by enhanced regional cerebral blood flow in the dorsolateral prefrontal and inferior temporal cortices as well as in the amygdaloid-hippocampal region. Brain blood flow was lower in the temporal pole and in the cerebellum. These results suggest that social phobia has a neuroanatomical basis in a highly sensitive fear network centered in the amygdaloid-hippocampal region and encompassing the prefrontal cortex.

Cette thèse analyse comment s'organise la coordination à long terme entre la production et le transport dans un système électrique libéralisé. Elle s'appuie sur un cadre d'analyse modulaire permettant de séparer les mécanismes de coordination en modules distincts. La structure de gouvernance du réseau de transport complète ce cadre d'analyse. Dans une logique de complémentarité institutionnelle, cette structure de gouvernance influence les options de gestion des flux effectivement mises en œuvre par les GRT. Le rôle proactif que le GRT doit prendre dans la coordination entre production et transport s'explique alors de deux façons. Tout d'abord, l'investissement en réseau peut être le seul procédé effectif de coordination à long terme entre production et transport. Ensuite, en anticipant le renforcement du réseau, le GRT peut préparer l'accueil des moyens de production les plus rapides à s'installer et prendre en compte la réaction des producteurs aux signaux de localisation.

Organizational scholars have long been interested in organizations which exemplify high reliability. While such organizational studies have provided valuable clues to the ways in which such organizations form and function, this paper argues that a more nuanced study of high reliability processes within team contexts is warranted. This study focuses on organizational teams which are faced with the challenges of maintaining high levels of reliability. Of particular interest is how teams manage adverse events which disrupt the team's process and how they make adaptations immediately to restore their functionality. In my dissertation, I: (1) explore the existing literature surrounding high reliability organization and resilience, (2) present a qualitative analysis of Special Weapons and Tactics (SWAT) teams to explore and identify factors surrounding adaptation within the critical moment, and (3) discuss the implications of these factors in the theory and research surrounding high-reliability teams. The findings of this study find strong connection with the work of Weick and serve to advance and clarify previous characteristics associated with high reliability organizing; however, by using the small group as the unit of analysis for the study additions to concepts traditionally associated with high reliability organizing can be noted: (1) controlling variability during team function, (2) accepting the value of the unexpected, (3) continuous forward motion, and (4) the role of tacit and explicit knowledge.

A verificação de uma trajetória de valorização do câmbio ao longo de 2004 e 2005, que diminui a competitividade do produto brasileiro e a rentabilidade do setor exportador, ressaltou a importância das operações com adiantamentos de contratos de câmbio (ACCs) como meio de driblar os percalços de um câmbio adverso e manter a atratividade, em termos de lucratividade, da atividade exportadora. Este trabalho, então, busca aumentar o conjunto de informações dos exportadores que vislumbram a possibilidade de realizar operações de arbitragem com ACCs, analisando mais detalhadamente os fatores que determinam os resultados das operações com ACCs e verificando o papel da dinâmica cambial sobre esses ganhos. Para tal, são utilizados modelos econométricos de variância condicionada auto-regressiva (ARCH), cujos resultados sinalizam uma relação significativa e positiva entre volatilidade do câmbio e maiores margens de retorno na arbitragem com ACCs. / The appreciation path described by the exchange rate along 2004 and 2005, which reduced the Brazilian product competitiveness and the exportations profitability, showed the anticipation of exchange rate contracts (ACCs) importance as a way to overcome an adverse exchange rate and maintain the attractiveness of the exportation activity. Afterward, we try to increase the set of information of the exporters that look forward an ACC arbitrage operation possibility, analyzing more carefully the issues that determine their results and verifying the exchange rate dynamics role in those gains. Indeed, employing auto regressive conditioned heteroscedasticity (ARCH) econometric models, the results point out a significant and positive relationship between exchange rate volatility and larger ACC arbitrage returns.

A verificação de uma trajetória de valorização do câmbio ao longo de 2004 e 2005, que diminui a competitividade do produto brasileiro e a rentabilidade do setor exportador, ressaltou a importância das operações com adiantamentos de contratos de câmbio (ACCs) como meio de driblar os percalços de um câmbio adverso e manter a atratividade, em termos de lucratividade, da atividade exportadora. Este trabalho, então, busca aumentar o conjunto de informações dos exportadores que vislumbram a possibilidade de realizar operações de arbitragem com ACCs, analisando mais detalhadamente os fatores que determinam os resultados das operações com ACCs e verificando o papel da dinâmica cambial sobre esses ganhos. Para tal, são utilizados modelos econométricos de variância condicionada auto-regressiva (ARCH), cujos resultados sinalizam uma relação significativa e positiva entre volatilidade do câmbio e maiores margens de retorno na arbitragem com ACCs. / The appreciation path described by the exchange rate along 2004 and 2005, which reduced the Brazilian product competitiveness and the exportations profitability, showed the anticipation of exchange rate contracts (ACCs) importance as a way to overcome an adverse exchange rate and maintain the attractiveness of the exportation activity. Afterward, we try to increase the set of information of the exporters that look forward an ACC arbitrage operation possibility, analyzing more carefully the issues that determine their results and verifying the exchange rate dynamics role in those gains. Indeed, employing auto regressive conditioned heteroscedasticity (ARCH) econometric models, the results point out a significant and positive relationship between exchange rate volatility and larger ACC arbitrage returns.

Made available in DSpace on 2014-06-11T19:35:16Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-08-13Bitstream added on 2014-06-13T19:46:25Z : No. of bitstreams: 1 binotti_ffs_dr_ilha.pdf: 5975802 bytes, checksum: 90bef1ffaba7ce8cb7d8049d45949057 (MD5) / O nitrogênio é um nutriente que pode propiciar efeitos benéficos na produtividade, na qualidade química e fisiológica das sementes de feijão. Assim, é de fundamental importância saber qual o momento adequado para sua aplicação e a fonte de N a ser utilizada, além da interação com a prática da inoculação de sementes com Rhizobium spp., em sistema plantio direto. O objetivo do trabalho foi o de estudar o efeito da inoculação de sementes, fontes e modos de aplicação de nitrogênio no desenvolvimento, produtividade, qualidade química e fisiológica de sementes do feijoeiro de inverno no sistema plantio direto em sucessão a milho e Brachiaria. O delineamento experimental foi o de blocos casualizados em esquema fatorial 2x2x8, com quatro repetições. O trabalho foi desenvolvido em Latossolo Vermelho Distrófico argiloso, Selvíria (MS) em dois anos (2006 e 2007) e os tratamentos foram constituídos pela combinação de inoculação de sementes (presença e ausência) com Rhizobium tropici (estirpes SEMIA 4077 + SEMIA 4080), fontes de nitrogênio (uréia – 45% de N e Entec 26® - 26 % de N + 13% de S + inibidor da nitrificação) e modos de aplicação de nitrogênio (testemunha – sem N, 30 dias antes da semeadura – DAS, 15 DAS, semeadura, 15 dias após semeadura no estádio V2 – DASe, 30 DASe no estádio V4, 1/3 Semeadura + 2/3 15 DASe, 1/3 Semeadura + 2/3 30 DASe) na dose de 90 kg ha-1. A uréia é o adubo nitrogenado recomendado para feijoeiro de inverno irrigado, podendo ser aplicado antecipadamente aos 15 DAS ou na semeadura e/ou cobertura. A inoculação propiciou maior teor de carboidratos (açúcares livres e amido) nas sementes, porém, não tem influencia diretamente na qualidade fisiológica e produtividade / Nitrogen is a nutrient that may provide beneficial effects on yield, physiological and chemical quality of common bean seeds. So, it is fundamental importance to know what the right time for its application and the source of N to be used in addition to interaction with the practice of seed inoculation with Rhizobium spp. in no tillage system. The objective of the work was to study the effect of seed inoculation, nitrogen sources and split in the growth, yield, physiological and chemical quality of the common bean seeds in the winter in no tillage system over graminea, in a dystrophic clayey Latosol – Haplustox, MS. The work was carried out in two years (2006 and 2007) in a randomized blocks design using a factorial scheme 2x2x8 and 4 repetitions, constituted by seed inoculation with Rhizobium tropici (presence and absence), two sources of nitrogen (urea - 45% nitrogen and Entec 26® - 26 % de N + 13% de S + DMPP molecules aiming to inhibit nitrification) and eight stadia of nitrogen application (control without N application, 30 days before sowing – DBS, 15 DBS, at sowing – S, 15 days after sowing – DBSe, 30 DBSe, 1/3 S + 2/3 15 DBSe, 1/3 S + 2/3 30 DBSe) at 90 kg ha-1. The urea nitrogen is recommended for irrigated winter common bean and can be applied in advance at 15 DBS or at sowing and/at sidedressing. The inoculation provided higher content of carbohydrates (free sugars and starch) in seeds however, does not directly influence the physiological quality and yield

This thesis investigates the sensitivity of derived monetary valuations of the well-being effects of non-market goods, by considering, in turn, the four components that contribute to these calculations. Comparisons are made to the current subjective well-being (SWB) literature by altering one component at a time in a willingness to pay (WTP) function, in addition to varying the estimator used when calculating WTP. The first component varied is the measure of income used; a more robust, up-to-date measure is proposed that takes into account household size, economies of scale and composition, plus other improvements over current income scaling approaches including equivalence scales. Secondly, anticipation and adaptation effects are examined, in order to allow for the dynamics of SWB in WTP valuations. Thirdly, due to the ordered nature of the dependent variable, the effects of both cardinal and ordinal models on WTP derivations are investigated. Such models include the ordered logit fixed effects (FE) model (see for example Das and Van Soest (1999), Ferrer-i-Carbonell and Frijters (2004) and Baetschmann et al. (2011)). The final input to be varied is whether income endogeneity is accounted for. A control function approach is used in this case. A key finding is that all four inputs in the WTP calculation contribute significantly to the estimated WTP values. However, the degree to which each input influences the variation in WTP values differs substantially. The three main contributing factors to WTP variations are the income variable chosen, anticipation and adaptation effects, and controlling for endogeneity. Additionally, this thesis proposes a new way to define WTP that is also valid for ordered estimators. Whilst the standard WTP approach relies simply on coefficient ratios at a point in time, the method proposed here uses the finding that statistically significant anticipation and adaptation effects, along with adaptation to all non-market events (except for unemployment) suggest that there are concerns with taking WTP values as yearly valuations that assume constant effects on SWB. By instead defining WTP as the summation of the value of all WTP effects over all lag and lead effect periods, the total value of an event can be calculated. This definition presents further weaknesses of the original method by showing that because of significant lag and lead effects for events such as divorce and widowhood, these events have substantially larger WTP values than first thought. This leads to the major finding in this study that rank orders are not preserved when controlling for income endogeneity, even when comparing two model specifications that are identical in all other respects. Therefore, despite absolute WTP valuations appearing more similar for linear and ordered estimators when a more appropriate model specification is in place, the rank orders are affected. This finding argues against papers such as Powdthavee and van den Berg (2011) that find that rank orders are preserved for WTP valuations when modelling SWB. In conclusion, given rank orders are generally not preserved when a small change is made in the model specification, the validity of the WTP method is significantly reduced. Finally, the above methodology is applied to education, with the main contribution to the education literature being that the positive effects on SWB from education only exist in terms of lead effects.