Defendo, nesta dissertação, uma interpretação materialista da filosofia humeana. Essa interpretação se apóia em alguns dos temas presentes no Livro 1 do Tratado da Natureza Humana. Divido a tarefa em três partes: no primeiro capítulo, examino dois dos princípios que fundamentam a teoria das idéias apresentada na Parte 1, o princípio da cópia e o da separabilidade. Juntos, eles implicam a impotência da razão a priori no domínio dos fatos. É a imaginação, uma faculdade corpórea, que assume o papel principal na epistemologia humeana; no segundo capítulo, examino a seção “Da imaterialidade da alma” (Parte 4, Seção 5), na qual a alma substancial desaparece e dá lugar a percepções causalmente relacionadas a um corpo. Aqui se evidencia a concepção fisicalista de Hume sobre o fenômeno cognitivo. Procuro esclarecer tal concepção por meio de uma comparação entre ela e a concepção de Reid, segundo a qual o fenômeno cognitivo é intrinsecamente imaterial e, portanto, sem qualquer relação causal com a matéria; o objeto do terceiro capítulo é a seção “Da identidade pessoal” (Parte 4, Seção 6), na qual Hume afirma que a crença nessa identidade decorre de associações de idéias. No Apêndice Hume reconhece a insuficiência de sua explicação inicial. Exponho alguns dos problemas que podem ter gerado as dúvidas do Apêndice e defendo que elas não configuram um possível abandono do materialismo, ou seja, da concepção ontológica que levou à tese de que a mente é um mero feixe de percepções relacionadas causalmente. / I defend, in this dissertation, a materialist interpretation of humean philosophy. This interpretation is based on some of the themes presented in Book 1 of the Treatise of Human Nature. The task is divided in three parts: in the first chapter, I examine two of the principles which ground the theory of ideas presented in Part 1, the principles of copy and of separability. Together, they imply the impotence of a priori reason in the factual domain. It is the imagination, a corporeal faculty, that assumes the leading role in humean epistemology; in the second chapter, I examine the section Of the immateriality of the soul (Part 4, Section 5), in which the substantial soul disappears and gives place to perceptions causally related to a body. Here, Hume’s phisicalist conception about the cognitive phenomena is evidenced. I try to explain this conception by comparing it to Reid’s conception, according to which cognitive phenomena is intrinsically imaterial and, therefore, without any causal relation to matter; the subject of the third chapter is the section “Of personal identity” (Part 4, Section 6), in which Hume states that the belief in this identity derives from associations of ideas. In the Appendix Hume recognizes the insufficiency of his early explanation. I expose some of the problems that may have engendered the doubts of the Appendix and defend that they don’t amount to a possible abandonment of materialism, that is, of the ontological conception which has led to the thesis of the mind as a simple bundle of perceptions causally related.

A percepção sobre as causas dos acontecimentos faz parte da vida cotidiana. Atribui-se causas aos eventos na busca de entendimento que permita prever, controlar e alterar resultados futuros. Questões como \"Por que não passei na prova?\" e \"Porque fui o primeiro colocado no vestibular?\" conduzem à percepção de uma causa explicativa, seja para o fracasso ou para o sucesso. A Teoria da Atribuição Causal tem sido examinada para compreender e explicar como as pessoas interpretam os determinantes de seu sucesso ou fracasso em situações de desempenho. As causas percebidas estarão relacionadas à percepção de cada indivíduo sobre o evento, o que não implica causalidade real, dado que a ação será efetivada de acordo com a percepção de cada indivíduo sobre o evento. A abordagem teórica utilizada nessa pesquisa foi a Teoria da Atribuição Causal, proposta por Bernard Weiner, no contexto educacional, com foco nas atribuições causais para sucesso e fracasso acadêmicos. Neste cenário, o objetivo principal da pesquisa foi identificar as causas percebidas como explicativas do desempenho acadêmico de estudantes do curso de Ciências Contábeis. Buscou-se também obter evidências e subsidiar a discussão sobre a relação entre o sucesso e o fracasso acadêmico, a modalidade de ensino, a autoestima e o perfil do estudante. Os dados foram coletados por meio de um questionário aplicado aos estudantes de Ciências Contábeis de duas Universidades Federais que oferecem o curso em duas modalidades de ensino (presencial e a distância) e 738 respostas válidas foram obtidas para análise. O questionário foi estruturado em três blocos (I - desempenho e causas percebidas, II - mensuração da autoestima e III - perfil do estudante). Os resultados apresentaram um perfil com idade média dos estudantes de 27,4 anos (34,27 na modalidade EaD e 24,87 na modalidade Presencial). A maioria dos estudantes (83%) exercia atividade remunerada (90% na EaD e 80% na presencial) e as mulheres representaram a maioria dos respondentes (62% na modalidade EaD e 58% na modalidade presencial). As causas internas, especificamente o esforço e a capacidade, foram mais indicadas como explicativas do sucesso acadêmico e as causas externas, especificamente a dificuldade da tarefa, a flexibilidade de horário e a influência negativa do professor, foram as mais indicadas como explicativas do fracasso acadêmico. Como os resultados apontam que os estudantes indicaram com frequência a própria capacidade para explicar o sucesso, pode-se admitir manifestação da tendência autoservidora, que contribui para a manutenção da autoestima, diante da influência positiva na motivação. Entre as causas do sucesso, a capacidade associou-se a um nível mais elevado de autoestima e a causa sorte associou-se a um nível mais baixo de autoestima. Entre as causas do fracasso, a dificuldade da tarefa associou-se ao nível mais baixo de autoestima. Uma análise geral permite observar que os estudantes dedicam pouco tempo aos estudos, atribuem sucesso principalmente a si mesmos e o fracasso a terceiros, e apresentam uma elevada autoestima associada principalmente ao sucesso atribuído à capacidade. Em futuras pesquisas, recomenda-se estudos pilotos, com objetivo de definir outras atribuições causais para elaboração de novos instrumentos de coleta de dados, por meio de abordagem metodológica qualitativa, que possam ampliar os achados e contribuir com a literatura. / The perception about causes of events is part of daily life. Causes are attributed to events in order to be able to make previsions, and control and change future outcomes. Questions like \"why didn\'t I pass the test?\" and \"Why was I the first place in the entrance exam?\" lead to perception of an explanatory cause for failure or success. The Theory of Causal Attribution has been examined to understand and explain how people interpret their success\' or failure\'s determinants in performance situations. The perceived causes will be related to the each individual\'s perception about the event, which does not imply real causality, given that the action takes place according to each individual\'s own perception about the event. The theoretical approach used in this research was the Theory of Causal Attribution, proposed by Bernard Weiner, in the educational context, focusing on causal attributions for academic success and failure. In this context, the main objective of this research was to identify the causes perceived as explanatory of Accounting students\' academic performance. The research also sought to obtain evidence and support to the discussion about the relationship among academic success and failure, the modality of education, self-esteem and students\' profile. The data were collected through a questionnaire administered to Accounting students of two Public Universities offering the Accounting major in two modalities of education (traditional and e-learning), and 738 valid answers were obtained to the analysis. The questionnaire was structured into three parts (I - performance and perceived causes, II - self-esteem measurement and III - students\' profile). The results showed a profile where students are 27.4 years old on average (34.27 in the e-learning modality and 24.87 in the traditional modality). Most students (83%) were working (90% in the e-learning and 80% in the traditional modality) and most respondents (62% in the e-learning and 58% in the traditional modality) were women. The internal causes, specifically effort and ability, were highlighted as explanatory factors for the academic success and the external causes, specifically task difficulty, schedule flexibility and the teacher\'s negative influence, were highlighted as explanatory factors for the academic failure. Since the results show that students often indicate their own ability to explain their success, this indicates a manifestation of the self-serving bias, which contributes to maintaining the self-esteem in the face of motivation\'s positive influence. Among the causes of success, the ability was associated with a higher level of self-esteem and luck was associated with a lower level of self-esteem. Among the causes of failure, the tasks\' difficulty was associated to the lower level of self-esteem. A general analysis allows observing that students spend little time studying, mainly attribute success to themselves and failure to others, and have a high self-esteem mainly associated to the success attributed to capacity. As future researches, pilot studies are recommended in order to set other causal attributions for developing new data collection instruments, through a qualitative approach, that can expand the findings and contribute to the literature.

A pesquisa teve por objetivo verificar se e como evangélicos vivenciam experiências anômalas do tipo extra-sensório-motoras, sob a ótica da Psicologia Social. Para tanto, utilizou-se o Questionário de Prevalência e Relevância de Psi (Q-PRP) e entrevista dirigida, de forma a contemplar aspectos quantitativos e qualitativos do estudo. Como aporte teórico para compreensão dos dados, fizemos uso da teoria de atribuição de causalidade, verificando como a percepção social e os eventos se relacionam. Do total de respondentes (N=126); 84,9% relataram ter vivenciado ao menos alguma das experiências abordadas no questionário. Respondentes tradicionais vivenciam menos experiências que respondentes neopentecostais, ou, na linguagem apresentada, neopentecostais são experienciadores de forma estatisticamente significante em relação aos tradicionais para cinco das doze experiências com as quais trabalhamos. A diferença entre as denominações também surgiu nas atribuições de causalidade, quando tradicionais fizeram atribuições a coincidência e ao poder da mente, enquanto neopentecostais (por diferença estatisticamente significante) fizeram atribuições a Deus. Os respondentes pentecostais se comportaram como um grupo impreciso, ora aproximando-se dos tradicionais, ora dos neopentecostais. A pesquisa tem um caráter exploratório e novos estudos se fazem necessários para aprofundamento das tendências aqui apontadas / The aim of this research is to verify if and how evangelical experience anomalous occurrences of extrasensorimotor type, from the perspective of Social Psychology. Therefore we used the Questionário de Prevalência e Relevância de Psi (Q-PRP) and oriented interview in order to contemplate quantitative and qualitative aspects of the study. As a theoretical framework for understanding the data, we used the attribution theory, to determine how the social perception and the events are related. Of the total respondents (N = 126); 84.9% claimed having experienced at least some of the occurrences addressed in the questionnaire. Traditional respondents experience less occurrences then the neopentecostal respondents, or, in the language presented, neopentecostals are experiencers a statistically significant manner compared to traditional to five of the twelve experiments with which we work. The difference between the denominations also appeared in causal attributions when the traditional ascribe the \"coincidence\" and the \"power of the mind\", while neopentecostal (a statistically significant difference) did ascribe to God. Pentecostals respondents behaved like an imprecise group, at times wavering closer to traditional and other times neopentecostals. This research has an exploratory character and further studies are needed to deepen the trends identified here

Este trabalho tem como objetivo utilizar medidas de causalidade entre séries temporais de grandezas financeiras para determinar a dependência entre os ativos do mercado e utilizar as medidas obtidas para fazer inferências sobre a dinâmica desses ativos. Essa metodologia define um previsor para os valores das séries que, juntamente com a determinação das distribuições de probabilidades empíricas dos erros desse previsor por meio do método de Kernel, permite a amostragem aleatória de cenários multivariados, com diversas aplicações. Os ativos considerados para os testes de causalidade são o índice Ibovespa, o valor da paridade da moeda dólar-real USDBRL (utilizando suas séries de preços e retornos de preços), além da taxa de juros negociada diariamente (CDI). O uso do Método de Monte Carlo (MMC) é abordado para a precificação de opções de compra europeias (calls) de USDBRL e Ibovespa, e a comparação dos resultados gerados por essa metodologia com valores calculados pela fórmula de Black-Scholes (método mais utilizado no mercado financeiro, atualmente), evidenciando suas vantagens e desvantagens. Conclui-se, com este estudo, que, por meio da metodologia proposta, é possível replicar alguns comportamentos intrínsecos do mercado (como a observação de tendências nas séries de preços devido a dependências implícitas, e a presença de caudas pesadas nas distribuições dos retornos) que são desprezados pela maioria dos modelos paramétricos utilizados hoje, bem como o efeito do uso dessas informações no preço de derivativos. / This paper proposes the use of causality measures applied over time-series of financial values to determine the dependency relations between market assets and a way to use the obtained measures to make inferences about the dynamics of these assets. This methodology defines a predictor for values of the time-series that, by determining the empirical probability distributions of the errors generated by this predictor based on the Kernel method, allows a random sampling of multivariated scenarios with many applications. The assets considered for the causality tests are the Ibovespa index, the dollar-real parity value USDBRL (using their price and price-return series), in addition to the daily traded interest rate (CDI). The use of the Monte Carlo Method (MMC) for the pricing of European call options (USDBRL) and Ibovespa was discussed, in addition to a comparison of the results generated by this methodology with values calculated by the Black-Scholes formula (currently the most used method by finance institutions), showing its advantages and disadvantages. The conclusion is that, based on the proposed methodology, it is possible to replicate some intrinsic market behaviors (such as the existence of trends in price series, due to implicit dependencies, and the presence of fat tails in the distributions of price-returns) that are neglected by most of parametric models, currently, as well as the effect of using this information for pricing derivatives.

Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-02-24T17:38:27Z No. of bitstreams: 1 jonathanestebanarroyosilva.pdf: 3851364 bytes, checksum: 7341b01ce42c37de611bb2df24f9012c (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-03-06T19:29:14Z (GMT) No. of bitstreams: 1 jonathanestebanarroyosilva.pdf: 3851364 bytes, checksum: 7341b01ce42c37de611bb2df24f9012c (MD5) / Made available in DSpace on 2017-03-06T19:29:14Z (GMT). No. of bitstreams: 1 jonathanestebanarroyosilva.pdf: 3851364 bytes, checksum: 7341b01ce42c37de611bb2df24f9012c (MD5) Previous issue date: 2014-02-24 / FAPEMIG - Fundação de Amparo à Pesquisa do Estado de Minas Gerais / Este trabalho apresenta um novo esquema de marcha no tempo capaz de reduzir oscilações espúrias através de amortecimento numérico para problemas de propagação de ondas elásticas no âmbito da Aproximação Explícita de Green (\Explicit Green's Approach" (ExGA)) [1]. A expressão integral referente ao ExGA é escrita em termos das funções de Green e Degrau. Seus cálculos são realizados de forma independente por meio da formulação semi-discreta do MEF e o método Diferença Central. Devido ao princípio da causalidade, as funções de Green e Degrau possuem um suporte compacto ao redor dos pontos fonte para um intervalo de tempo suficientemente pequeno que é usualmente Empregado nos métodos explícitos clássicos de integração temporal aplicados à modelagem de propagação de ondas. Neste sentido, as funções de Green e Degrau em t = Δt podem ser eficientemente calculadas localmente através de subdomínios pequenos. Cada subdomínio local com sua respectiva submalha cobre somente pontos nodais onde os valores das funções de Green e Degrau são não nulos. A precisão e eficiência da metodologia proposta é demostrada ao analisar três exemplos numéricos. / This work presents a new time-marching scheme able to reduce spurious oscillations by means of numerical damping for elastic wave propagation problems in the framework of the Explicit Green's Approach (ExGA) [1]. The integral expression concerned with the ExGA is written in terms of the Green's and the Step response functions. Their computations are carried out independently by means of the semidiscrete FEM and the Central difference method. Due to the principle of causality, the Green's and Step response functions admit a compact support surround the source points for a small enough time step that is usually employed in common explicit time integration methods applied to wave propagation modeling. In this sense, the Green's and Step response functions at t = Δt can be e ciently computed locally through small subdomains. Each local subdomain with its respective submesh covers only nodes whose Green's and Step response function values do not vanish. The accuracy and e ciency of the proposed methodology are demonstrated by analyzing three numerical examples.

Submitted by Eliene Soares da Silva (eliene.silva@fgv.br) on 2013-02-14T11:32:36Z No. of bitstreams: 1 MPGI MasterThesis Mattia Ambrosini 645094.pdf: 1221533 bytes, checksum: 1117aaa68ec08569df715c16c4e0e0d0 (MD5) / Approved for entry into archive by Eliene Soares da Silva (eliene.silva@fgv.br) on 2013-02-14T11:44:31Z (GMT) No. of bitstreams: 1 MPGI MasterThesis Mattia Ambrosini 645094.pdf: 1221533 bytes, checksum: 1117aaa68ec08569df715c16c4e0e0d0 (MD5) / Made available in DSpace on 2013-02-14T12:08:26Z (GMT). No. of bitstreams: 1 MPGI MasterThesis Mattia Ambrosini 645094.pdf: 1221533 bytes, checksum: 1117aaa68ec08569df715c16c4e0e0d0 (MD5) Previous issue date: 2012-12-20 / The thesis at hand adds to the existing literature by investigating the relationship between economic growth and outward foreign direct investments (OFDI) on a set of 16 emerging countries. Two different econometric techniques are employed: a panel data regression analysis and a time-series causality analysis. Results from the regression analysis indicate a positive and significant correlation between OFDI and economic growth. Additionally, the coefficient for the OFDI variable is robust in the sense specified by the Extreme Bound Analysis (EBA). On the other hand, the findings of the causality analysis are particularly heterogeneous. The vector autoregression (VAR) and the vector error correction model (VECM) approaches identify unidirectional Granger causality running either from OFDI to GDP or from GDP to OFDI in six countries. In four economies causality among the two variables is bidirectional, whereas in five countries no causality relationship between OFDI and GDP seems to be present.

La thèse décrit un processus d’extraction d’informations causales dans les textes économiques qui, contrairement à l’économétrie, se fonde essentiellement sur des ressources linguistiques. En effet, l’économétrie appréhende la notion causale selon des modèles mathématiques et statistiques qui aujourd’hui sont sujets à controverses. Aussi, notre démarche se propose de compléter ou appuyer les modèles économétriques. Il s’agit d’annoter automatiquement des segments textuels selon la méthode de l’exploration contextuelle (EC). L’EC est une stratégie linguistique et computationnelle qui vise à extraire des connaissances selon un point de vue. Par conséquent, cette contribution adopte le point de vue discursif de la causalité où les catégories sont structurées dans une carte sémantique permettant l’élaboration des règles abductives implémentées dans les systèmes EXCOM2 et SEMANTAS. / The thesis describes a process of extraction of causal information, which contrary to econometric, is essentially based on linguistic knowledge. Econometric exploits mathematic or statistic models, which are now, subject of controversy. So, our approach intends to complete or to support the econometric models. It deals with to annotate automatically textual segments according to Contextual Exploration (CE) method. The CE is a linguistic and computational strategy aimed at extracting knowledge according to points of view. Therefore, this contribution adopts the discursive point of view of causality where the categories are structured in a semantic map. These categories allow to elaborate abductive rules implemented in the systems EXCOM2 and SEMANTAS.

La notion de risque est doublement incertaine : elle contient une part irréductible d’aléa quant à sa concrétisation en dommage d’une part, elle n’est pas définie par la loi d’autre part. Pourtant, cette lacune est en contradiction, tant avec le recours exponentiel à la notion de risque en droit pénal, qu’il soit de fond ou de forme, qu’avec le principe de légalité des délits et des peines, qui implique que le législateur définisse avec clarté et précision les notions et concepts auxquels il fait appel, de sorte que la légitimité de son usage en droit pénal peut être mise en doute. La présence d’une notion aussi incertaine dans une matière qui met en cause les droits fondamentaux de la personne est susceptible de mettre en péril les impératifs de l’État de droit. Au demeurant, ce droit pénal de l’anticipation, qui vise à prévenir la survenance d’une atteinte possible mais incertaine à une valeur protégée, essuie de nombreuses critiques. L’objet de cette démonstration est donc de savoir si le législateur emploie à bon escient ou non la notion de risque en droit pénal. La réponse à cette problématique nécessitera au préalable, de s’assurer que le droit pénal est effectivement légitime à s’intéresser à la notion de risque. Ce n’est pas parce que le législateur consacre une notion que sa prise en compte est forcément légitime. Plus encore, il faut garder à l’esprit que risque et droit pénal sont par nature contradictoires : le risque est incertain, immatériel et relève de la prévention tandis que le droit pénal est le droit de la répression, de la matérialité et de la certitude. Une étude approfondie de leurs natures respectives permettra néanmoins de dépasser la contradiction, attestant alors de ce que le droit pénal est théoriquement légitime à réceptionner la notion de risque. Cette légitimité n’en reste pas moins précaire. Pour la garantir, il ne pourra s’agir que d’un certain risque, c’est-à-dire un risque pourvu d’une certaine qualité, car le législateur, s’il prétend recourir à la notion de risque en droit pénal pour assurer à la société une protection pénale anticipée, ne peut se départir des principes qui y sont applicables. À partir de l’étude des principes fondamentaux du droit pénal, de ses concepts juridiques et de ses sources supralégislatives, cette recherche se proposera alors d’élaborer une définition pénale de la notion de risque, contenant les critères théoriques d’un risque pénalement saisissable en toute légitimité. Leur confrontation, ensuite, avec le droit positif, permettra de révéler si l’exploitation de la notion de risque par le législateur en droit pénal, fait perdre ou non à ce dernier sa légitimité. / The notion of risk is doubly uncertain: it contains an irreducible part of hazard as its realization in damage on the one hand, and its lack of definition by the law on the other. However, this gap is at odds, both with the exponential use of the notion of risk in criminal law, whether substantive or form, and with the principle of legality of offences and sentences, which implies that the legislator defines clearly and precisely the notions and concepts to which it refers. That is the reason why the legitimacy of the use of the notion of risk in criminal law can be questionable. The presence of such an uncertain notion in a field involving the fundamental rights of the person is likely to jeopardize the imperatives of the State of laws. Moreover, the criminal law of anticipation, which aims to prevent the occurrence of possible but uncertain interference with a protected right, is criticized. The purpose of this demonstration is therefore to know whether or not the legislature uses wisely the notion of risk in criminal law. The answer to this issue will previously require to ensure that criminal law is actually legitimate to focus on the notion of risk. This is not because the legislature takes into account a notion that its account is necessarily legitimate. Moreover, it is important to keep in mind that risk and the criminal law are inherently contradictory: the risk is uncertain, immaterial and is linked to the concept of prevention while the criminal law is the right of repression, the materiality and the certainty. A deep study of their respective natures will nevertheless make it possible to overcome the contradiction, stating that the criminal law is theoretically legitimate to accept the notion of risk. This legitimacy stays nonetheless quite precarious. To secure this legitimacy, only a certain kind of risk, a risk with a managed level can be taken into account. If the legislator claims using the notion of risk in criminal law for anticipated criminal protection of society, he still cannot ignore the principles that are applicable in criminal law. From the study of the fundamental principles of criminal law, its legal concepts and its supralegislatives sources, this research will then offer a definition of the notion of risk in criminal law, containing the theoretical criteria of a legitimate criminally detectable risk. Its comparison with positive law, will emphasize whether the use of the notion of risk by the legislator in criminal law, makes him lose or not its legitimacy.

This essay focuses on four different aspects of readability: voice, causality, advanced words and the LIX-value of words. Each of these four facilitates or aggravates reading comprehension for students, which is further defined in the paper. The study is an analysis of textbooks in history for 8th grade from a second language perspective. In terms of voice, causality, advanced words and the LIX-value of words, the study shows that books with higher grades of causality and voice and lower grades of advanced words as well as a low degree of LIX-value are better for students to work with. / Uppsatsen lägger fokus på fyra olika aspekter kring läsbarhet: röst, kausalitet, avancerade ord och läsbarhetsindex. Var och en av dessa fyra underlättar eller försvårar läsförståelsen för elever vilket definieras vidare i uppsatsen. Grunden för analysen är byggd på undersökningar av undervisningsmaterial i historia för årskurs 8 från ett andraspråksperspektiv. Med utgångspunkt i röst, kausalitet, avancerade ord och ords läsbarhetsindex visar studien att läroböcker med en högre grad av röst och kausalitet samt en lägre grad av avancerade ord och läsbarhetsindex är lämpligare för andraspråkselever att arbeta med.

La commande de systèmes physiques s’avère être une tâche difficile en général. En fonction du modèle choisi, les outils mathématiques pour l’analyse et la conception de lois de commande peuvent changés. Pour les systèmes décrits par une représentation entrée-sortie, type transfert, ou par une équation de type état, les principales informations exploitées lors de la phase d’analyse concerne la structure interne du modèle (structure finie) et la structure externe (structure à l’infini) qui permettent avant la phase de synthèse de connaître, sur le modèle en boucle ouverte, les propriétés des lois de commande envisagées ainsi que les propriétés du système piloté (stabilité…).Le travail porte principalement sur l’étude des zéros invariants des systèmes physiques représentés par bond graph, en particulier dans un contexte de modèle type LTV. L’approche algébrique est essentielle dans ce contexte car même si les aspects graphiques restent très proches du cas linéaire classique, l’extension aux modèles LTV reste très complexe d’un point de vue mathématique, en particulier pour le calcul de racines de polynômes. De nouvelles techniques d’analyse des zéros invariants utilisant conjointement l’approche bond graph (exploitation de la causalité) et l’approche algébriques ont permis de mettre en perspective certains modules associés à ces zéros invariants et de clarifier le problème d’annulation des grandeurs de sortie. L’application aux problèmes d’observateurs à entrées inconnues a permis d’illustrer nos propos sur des exemples physiques, avec certaines extensions, problèmes pour lesquels les zéros invariants apparaissent aussi comme éléments essentiels / The control synthesis of physical systems is a complex task because it requires the knowledge of a "good model" and according to the choice of a model some specific tools must be developed. These tools, mainly developed from a mathematical and theoretical point of view, must be used from the analysis step (analysis of model properties) to the control synthesis step. It is well-known that in many approaches, the properties of the controlled systems can be analyzed from the initial model. If the system is described with an input-output representation or with a state space representation, two kinds of information are often pointed out: the external structure (infinite structure) and the internal structure (finite structure). The first one is often related to the existence of some control strategies (input-output decoupling, disturbance decoupling...) and the second one gives some focus on the stability property of the controlled system.In this report, the focus has been on the study of invariant zeros of bond graph models in the context of LTV models. The algebraic approach was essential because, even if the problem is already solved for LTI bond graph models, the extension to LTV models is not so easy. The simultaneous use of algebraic and graphical approaches has been proven to be effective and convenient to solve this problem. First, some tools from the algebraic approach have been recalled in chapter one and results for the study of invariant zeros of LTI bond graph models recalled in chapter two. Some new developments are proposed in chapter three and some applications for the unknown input observer problem with some physical applications conclude this work