Teses / dissertações sobre o tema "Modèle SEMK"
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Chakkingal, Anoop. "Réglage de la sélectivité de la synthèse Fischer-Tropsch : aperçu de la modélisation microcinétique et de l'apprentissage automatique". Electronic Thesis or Diss., Centrale Lille Institut, 2022. http://www.theses.fr/2022CLIL0015.
Striving towards a circular economy has led to the re-investigation of many existing processes, with the target of developing more sustainable variants. In our present economy, plastics form an important and omnipresent material affecting our daily lives. They are inexpensive, durable, corrosion resistant, and light weight leading to their use in a wide variety of applications.Within the plastic chemical recycling scheme, Fischer-Tropsch synthesis (FTS) could play a key role as the syngas feedstock that is converted in it, can be generated via the gasification of the considered plastics. This syngas is then chemo-catalytically converted into hydrocarbons such as paraffins and light olefins. Typical FTS catalysts are based on supported cobalt or iron species.Among the mechanistic kinetic models, the comprehensive variant based on the Single Event MicroKinetics (SEMK) concept has been widely applied in the field of oligomerization, autoxidative curing, etc. and has proven to be a versatile tool to simulate Fischer-Tropsch synthesis. However, developing mechanistic models for every chemical engineering challenge is not always feasible due to their complexity and the in-depth knowledge required to build such models.A detailed evaluation on the potential of using machine learning approaches to match the performance of results obtained using the Single-Event MicroKinetic model was carried out. Initially, the focus was on a single dominant output scenario (methane selective catalyst). The current work thus shows that more widely applied techniques in data science can now be applied for systematic analysis and interpretation of kinetic data. Similar analysis using experimental data can also help experimenters in their preliminary analysis, to detect hidden trends in the data, and thus to identify importance features. After gaining confidence on the investigated interpretation techniques, for the FTS reaction with single dominant output, a similar investigation on the potential of iron based catalysts with enhanced light olefin selectivity is carried out next
AMMOUCHE, ABDELHALIM. "Intégration de modèles physiques de composants semi-conducteurs dans un modèle électromagnétique". Paris 10, 1999. http://www.theses.fr/1999PA100076.
Lorenz, David [Verfasser], e Christian [Akademischer Betreuer] Mair. "Contractions of English semi-modals: the emancipating effect of frequency = Kontraktionen englischer Semi-Modale: lexikalische Emanzipation als Frequenzeffekt". Freiburg : Universität, 2013. http://d-nb.info/1122646666/34.
Lerat, Julien. "Quels apports hydrologiques pour les modèles hydrauliques ? : vers un modèle intégré de simulation des crues". Phd thesis, Université Pierre et Marie Curie - Paris VI, 2009. http://tel.archives-ouvertes.fr/tel-00392240.
Une méthode automatisée de découpage du bassin intermédiaire en sous-bassins a d'abord été élaborée afin de faciliter la construction du modèle hydrologique sur les 50 tronçons de rivière. Des tests de sensibilité ont été menés sur le nombre de sous-bassins, la nature uniforme ou distribuée des entrées de pluie et des paramètres du modèle hydrologique. Une configuration à 4 sous-bassins présentant des pluies et des paramètres uniformes s'est avérée la plus performante sur l'ensemble de l'échantillon.
Enfin, une méthode alternative de calcul des apports latéraux a été proposée utilisant une transposition du débit mesuré à l'amont et une combinaison avec le modèle hydrologique.
Pertsinidou, Christina Elisavet. "Stochastic models for the estimation of the seismic hazard". Thesis, Compiègne, 2017. http://www.theses.fr/2017COMP2342.
In the first chapter the definition of the seismic hazard assessment is provided, the seismotectonic features of the study areas are briefly presented and the already existing mathematical models applied in the field of Seismology are thoroughly reviewed. In chapter 2, different semi-Markov models are developed for studying the seismicity of the areas of the central Ionian Islands and the North Aegean Sea (Greece). Quantities such as the kernel and the destination probabilities are evaluated, considering geometric, discrete-Weibull and Pareto distributed sojourn times. Useful results are obtained for forecasting purposes. In the third chapter a new Viterbi algorithm for hidden semi-Markov models is developed, whose complexity is a linear function of the number of observations and a quadratic function of the number of hidden states, the lowest existing in the literature. Furthermore, an extension of this new algorithm is introduced for the case that an observation depends on the corresponding hidden state but also on the previous observation (SM1-M1 case). In chapter 4, different hidden semi-Markov models (HSMMs) are applied for the study of the North and South Aegean Sea. The earthquake magnitudes and locations comprise the observation sequence and the new Viterbi algorithm is implemented in order to decode the hidden stress field associated with seismogenesis. Precursory phases (variations of the hidden stress field) were detected warning for an anticipated earthquake occurrence for 70 out of 88 cases (the optimal model’s score). The sojourn times of the hidden process were assumed to follow Poisson, logarithmic or negative binomial distributions, whereas the hidden stress levels were classified into 2, 3 or 4 states. HMMs were also adapted without presenting significant results as for the precursory phases. In chapter 5 a generalized Viterbi algorithm for HSMMs is constructed in the sense that now transitions to the same hidden state are allowed and can also be decoded. Furthermore, an extension of this generalized algorithm in the SM1-M1 context is given. In chapter 6 we modify adequately the Cramér-Lundberg model considering negative and positive claims, in order to describe the evolution in time of the Coulomb failure function changes (ΔCFF values) computed at the locations of seven strong (M ≥ 6) earthquakes of the North Aegean Sea. Ruin probability formulas are derived and proved in a general form. Corollaries are also formulated for the exponential and the Pareto distribution. The aim is to shed light to the following problem posed by the seismologists: During a specific year why did an earthquake occur at a specific location and not at another location in seismotectonically homogeneous areas with positive ΔCFF values (stress enhanced areas). The results demonstrate that the new probability formulas can contribute in answering the aforementioned question
Liquet, benoit. "Sélection de modèles semi-paramétriques". Phd thesis, Université Victor Segalen - Bordeaux II, 2002. http://tel.archives-ouvertes.fr/tel-00002430.
Liquet, Benoit. "Sélection de modèles semi-paramétriques". Bordeaux 2, 2002. http://www.theses.fr/2002BOR20958.
Vandewalle, Vincent. "Estimation et sélection en classification semi-supervisée". Phd thesis, Université des Sciences et Technologie de Lille - Lille I, 2009. http://tel.archives-ouvertes.fr/tel-00447141.
Roget-Vial, Céline. "deux contributions à l'étude semi-paramétrique d'un modèle de régression". Phd thesis, Université Rennes 1, 2003. http://tel.archives-ouvertes.fr/tel-00008730.
Barouni, Foued. "Modèle dynamique de pilotage d'un système multiagents semi-compétitifs". Thesis, Université Laval, 2007. http://www.theses.ulaval.ca/2007/24398/24398.pdf.
Khadraoui, Lobna. "Sélection de copules archimédiennes dans un modèle semi-paramétrique". Master's thesis, Université Laval, 2018. http://hdl.handle.net/20.500.11794/30251.
This work considers a semi-parametric linear model with error terms modeled by a copula chosen from the Archimedean family or the normal copula. The modeling of errors by a copula provides flexibility and makes it possible to characterize the dependency structure in a simple and effective manner. The simplicity lies in the fact that a single parameter α controls the degree of dependency present in the data. The efficiency is in the fact that this semi-parametric model weakens standard assumptions often encountered in applied statistics namely normality and independence. After an implementation of the model based on a copula we proposed a theoretical study on the asymptotic behavior of the estimator of the dependence parameter α by showing its consistency and its asymptotic normality under classical assumptions of regularity. Estimation of the model parameters is performed by maximizing a pseudo-likelihood. The selection of the best copula that fits the data for each case is based on the Akaike selection criterion. A comparison with the criterion of cross-validation is presented as well. Finally, a numerical study on simulated and real data sets is proposed.
Votsi, Irène. "Evaluation des risques sismiques par des modèles markoviens cachés et semi-markoviens cachés et de l'estimation de la statistique". Thesis, Compiègne, 2013. http://www.theses.fr/2013COMP2058.
The first chapter describes the definition of the subject under study, the current state of science in this area and the objectives. In the second chapter, continuous-time semi-Markov models are studied and applied in order to contribute to seismic hazard assessment in Northern Aegean Sea (Greece). Expressions for different important indicators of the semi- Markov process are obtained, providing forecasting results about the time, the space and the magnitude of the ensuing strong earthquake. Chapters 3 and 4 describe a first attempt to model earthquake occurrence by means of discrete-time hidden Markov models (HMMs) and hidden semi-Markov models (HSMMs), respectively. A nonparametric estimation method is followed by means of which, insights into features of the earthquake process are provided which are hard to detect otherwise. Important indicators concerning the levels of the stress field are estimated by means of the suggested HMM and HSMM. Chapter 5 includes our main contribution to the theory of stochastic processes, the investigation and the estimation of the discrete-time intensity of the hitting time (DTIHT) for the first time referring to semi-Markov chains (SMCs) and hidden Markov renewal chains (HMRCs). A simple formula is presented for the evaluation of the DTIHT along with its statistical estimator for both SMCs and HMRCs. In addition, the asymptotic properties of the estimators are proved, including strong consistency and asymptotic normality. In chapter 6, a comparison between HMMs and HSMMs in a Markov and a semi-Markov framework is given in order to highlight possible differences in their stochastic behavior partially governed by their transition probability matrices. Basic results are presented in the general case where specific distributions are assumed for sojourn times as well as in the special case concerning the models applied in the previous chapters, where the sojourn time distributions are estimated non-parametrically. The impact of the differences is observed through the calculation of the mean value and the variance of the number of steps that the Markov chain (HMM case) and the EMC (HSMM case) need to make for visiting for the first time a particular state. Finally, Chapter 7 presents concluding remarks, perspectives and future work
Julius, Elroy Peter. "Guaranteed delivery of multimodal semi-synchronous IP-based communication". Thesis, University of the Western Cape, 2005. http://etd.uwc.ac.za/index.php?module=etd&.
This thesis explored how hearing and deaf users are brought together into one communication space where interaction between them is a semi-synchronous form of message exchange. The focus of this thesis was the means by which message delivery between two e
Orecchia, Giulio. "A monodromy criterion for existence of Néron models and a result on semi-factoriality". Thesis, Bordeaux, 2018. http://www.theses.fr/2018BORD0017/document.
This thesis is subdivided in two parts. In the first part, we introduce a new condition, called toric-additivity, on a family of abelian varieties degenerating to a semi-abelian scheme over a normal crossing divisor. The condition depends only on the Tate module TlA(Ksep) of the generic fibre, for a prime l invertible on the base. We show that toric-additivity is a sufficient condition for the existence of a Néron model if the base is a Q-scheme. In the case of the jacobian of a smooth curve with semi-stable reduction, we obtain the same result without assumptions on the base characteristic; and we show that toric-additivity is also necessary for the existence of a Néron model, when the base is a Q-scheme. In the second part, we consider the case of a family of nodal curves over a discrete valuation ring, having split singularities. We say that such a family is semi factorial if every line bundle on the generic fibre extends to a line bundle on the total space. We give a necessary and sufficient condition for semi- factoriality, in terms of combinatorics of the dual graph of the special fibre. In particular, we show that performing one blow-up with center the non regular closed points yields a semi-factorial model of the generic fibre. As an application, we extend the result of Raynaud relating Néron models of smooth curves and Picard functors of their regular models to the case of nodal curves having a semi-factorial model
Nguyen, ThiMongNgoc. "Estimation récursive pour des modèles semi-paramétriques". Thesis, Bordeaux 1, 2010. http://www.theses.fr/2010BOR14107/document.
Nguyen, Thi Mong Ngoc. "Estimation récursive pour les modèles semi-paramétriques". Phd thesis, Université Sciences et Technologies - Bordeaux I, 2010. http://tel.archives-ouvertes.fr/tel-00938607.
Heutte, Natacha. "Modèles semi-markoviens et données de survie". Paris 5, 2001. http://www.theses.fr/2001PA05S013.
Models for survival data including a categorized quality of life index is proposed. The model is intended to take into account the effect of endogenous and exogenous factors both on the duration of survival and the quality of life. Endogenous factors are for example biological measurements or genetical specifications, while exogenous ones are environmental factors. The proposed models are semi-parametric and based on semi-markov processes. Time may be continuous or discrete depending on the type of the data. The general framework of all preexisting models is sketched. Estimators are derived, as well as their asymptotic properties, and algorithms and programs are given to compute them explicitly. They are exemplified on real data on AIDS and cancer patients, and on simulations. Those models are presented in a biomedical context but can be useful in any field where durations together with multistate processes are involved
Biessy, Guillaume. "Semi-Markov modeling of the loss of autonomy among elderly people : application to long-term care insurance". Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLE048/document.
A sizable challenge to modern societies, Long-Term Care (LTC) in elderly people may be defined as a state of incapacity to perform autonomously part of the Activities of Daily Living (ADL). In most cases, long-term care is caused by pathologies linked to aging. To cope with the sizeable costs linked to this state, private insurers have developed products in top of the public aid. To quantify the long-term care risk, multi-state models are used for which transition probabilities betweenstates (autononomy, death and one to several levels of LTC) need to be inferred. Under the Markov assumption, those probabilities only depend on the current state, this assumption being too restrictive in regards of the complexity of the underlying risk. In a semi-Markov framework, those probabilities also depends on the time spent in the current state. In this thesis, we emphasis the need for the semi-Markov modeling. We demonstrate the impact of time spent in LTC on death probabilities. Besides, we exhibit that taking into account the diversity induced by pathologies leads to sizable improvementsin the fit of the model to experience data. Furthermore, we highlight that the peculiar shape taken by death probabilities as a function of time spent in LTC may be explained by the mixture of pathology groups among the disabled population
Thébault, Cyril. "Quels apports d'une approche multi-modèle semi-distribuée pour la prévision des débits ?" Electronic Thesis or Diss., Sorbonne université, 2023. http://www.theses.fr/2023SORUS649.
Streamflow forecasting is needed to meet various objectives, from the safety of populations in the case of floods, to the management of water resources for multiple uses, particularly important during low flow periods. Hydroelectric production is also closely linked to streamflow, as is the case on the Rhône catchment, where the Compagnie Nationale du Rhône (CNR) manages hydroelectric production units along the main course of the river. To optimize its production, CNR relies in part on hydrological models, which transform meteorological information into streamflow estimates. Hydrological models have their own specificities, in terms of the way they represent the catchment (i.e. their mathematical structure) or the way they are applied, linked to the objectives or hydro-climatic contexts for which they were designed. It leads to a very wide range of hydrological models, representing various rainfall-runoff relationships and operating at different spatial scales, often making it difficult for users to choose the structure and spatial discretization best suited to their objectives. This also reflects the numerous uncertainties affecting the modelling chain, the quantification of which is of major importance for operational management and decision support. In this context, the aim of this PhD is to evaluate the contribution of a semi-distributed multi-model approach for streamflow forecasting. To this end, a large sample of 643 French catchments, with hydro-climatic data at hourly time steps, was compiled, and 14 hydrological model structures were used according to different calibration strategies and for different spatial configurations. First, we set up the hydrological modelling framework to meet our objectives. After that, we tested the semi-distributed multi-model approach in a simulation context, and then for streamflow forecasting purposes, focusing on the case of Rhône tributaries. The results show that the strategy of a single model for a large number of catchments has limitations that can be partly overcome by multi-model strategies. In this way, the use of different hydrological models for different catchment areas leads to an improvement in streamflow simulation over the French territory. Even better performance can be achieved by a more complex multi-model approach, combining the outputs of hydrological models. Although the value of semi-distribution is difficult to determine a priori, it is nevertheless showing encouraging results over several catchments. Finally, semi-distributed multi-model modelling also improves forecasting, whether in an idealized context of known future rainfall, or in a more realistic context of ensemble meteorological forecast. Although generating more reliable forecasts, the chaining between ensemble meteorological forecasts and the probabilistic multi-model approach (thus creating a hydrological superset) requires an interpretation phase to be exploitable from an operational point of view
Bond, S. A. "Dynamic models of semi-variance". Thesis, University of Cambridge, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.596758.
Bush, Christopher A. "Semi-parametric Bayesian linear models /". The Ohio State University, 1994. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487856076417948.
Brefeld, Ulf. "Semi-supervised structured prediction models". Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät II, 2008. http://dx.doi.org/10.18452/15748.
Learning mappings between arbitrary structured input and output variables is a fundamental problem in machine learning. It covers many natural learning tasks and challenges the standard model of learning a mapping from independently drawn instances to a small set of labels. Potential applications include classification with a class taxonomy, named entity recognition, and natural language parsing. In these structured domains, labeled training instances are generally expensive to obtain while unlabeled inputs are readily available and inexpensive. This thesis deals with semi-supervised learning of discriminative models for structured output variables. The analytical techniques and algorithms of classical semi-supervised learning are lifted to the structured setting. Several approaches based on different assumptions of the data are presented. Co-learning, for instance, maximizes the agreement among multiple hypotheses while transductive approaches rely on an implicit cluster assumption. Furthermore, in the framework of this dissertation, a case study on email batch detection in message streams is presented. The involved tasks exhibit an inherent cluster structure and the presented solution exploits the streaming nature of the data. The different approaches are developed into semi-supervised structured prediction models and efficient optimization strategies thereof are presented. The novel algorithms generalize state-of-the-art approaches in structural learning such as structural support vector machines. Empirical results show that the semi-supervised algorithms lead to significantly lower error rates than their fully supervised counterparts in many application areas, including multi-class classification, named entity recognition, and natural language parsing.
MAILLOT, BERTRAND. "Modeles semi-microscopiques d'ondes elastiques". Paris 7, 1994. http://www.theses.fr/1994PA077158.
Abgrall, Rémi. "Conception d'un modele semi lagrangien de turbulence bidimensionnelle". Paris 6, 1987. http://www.theses.fr/1987PA066764.
Génieys, Stéphane. "Modele de transport d'energie pour les semi-conducteurs". Toulouse 3, 1997. http://www.theses.fr/1997TOU30247.
Yao, Anne-Françoise. "Un modèle semi-paramétrique pour variables fonctionnelles : la régression inverse fonctionnelle". Toulouse 3, 2001. http://www.theses.fr/2001TOU30122.
Tinland, Bernard. "Etude d'un polysaccharide microbien : le xanthane, modèle de molécule semi-rigide". Grenoble 1, 1988. http://www.theses.fr/1988GRE10039.
Santos, Douglas Gomes dos. "Estimação de volatilidade em séries financeiras : modelos aditivos semi-paramétricos e GARCH". reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2008. http://hdl.handle.net/10183/14892.
Volatility estimation and forecasting are very important matters for the financial markets. Themes like risk and uncertainty in modern economic theory have encouraged the search for methods that allow for the modeling of time varying variances. The main objective of this dissertation is to compare global and local regressions in terms of their capacity to extract the volatility of Ibovespa and Standard and Poor 500 indexes. To achieve this aim, parametric GARCH and semiparametric additive models estimation and forecasting are performed. The first ones, traditionally applied in the estimation of conditional second moments, have their capacity suggested in many papers. The second ones provide high flexibility and visually informative descriptions of the relationships between the variables, like asymmetries and nonlinearities. Therefore, testing the last ones´ performance against the acknowledged parametric structures is an appropriate investigation. Comparisons are made in selected periods of high volatility in the international financial market (crisis), measuring the models´ performance inside and outside sample. The results that were found suggest the capacity of semiparametric models to estimate and forecast the Indexes returns´ volatility at the analyzed moments.
Das, Sourav. "Models of semi-systematic visual search". Connect to this title online, 2007. http://etd.lib.clemson.edu/documents/1181250703/.
Tran, Quang-Dat. "Modèle simplifié pour les chaussées fissurées multicouches". Marne-la-vallée, ENPC, 2004. https://pastel.archives-ouvertes.fr/pastel-00001026.
Basdevant, Nathalie. "Un Modèle de Solvatation Semi-Implicite pour la Simulation des Macromolécules Biologiques". Phd thesis, Université d'Evry-Val d'Essonne, 2003. http://tel.archives-ouvertes.fr/tel-00010619.
Balieu, Romain. "Modèle viscoélastique-viscoplastique couplé avec endommagement pour les matériaux polymères semi-cristallins". Phd thesis, Université de Valenciennes et du Hainaut-Cambresis, 2012. http://tel.archives-ouvertes.fr/tel-00819902.
Martin, Christophe. "Rhéologie et structure d'un alliage modèle Sn-Pb à l'état semi-solide". Grenoble INPG, 1995. http://www.theses.fr/1995INPG0128.
Ben, Jemaa Kaouther. "Les facteurs du stress des alliances stratégiques : une grille de lecture selon le modèle SMOCS". Thesis, Sorbonne Paris Cité, 2017. http://www.theses.fr/2017USPCD026.
While strategic alliances have been the subject of several studies in strategic management, this phenomenon under stress remains little explored. This thesis will study the concept of stressed strategic alliances, which it develops by enlarging the strategic perspective of stress in organizations. It emerges from the review of the literature that the strategic alliance is an unstable inter-company form, a risky and inequitable strategy. It undergoes the action and the presence of several internal and external forces that menace its survival, under risk of imbalances or dysfunctions that contribute to difficulties. Therefore, the partners must understand adaptive measures, adjustments and negotiations. The review of the literature of the failure and instability of alliances established based on the model SMOCS (Smida, 1995) allowed us to suggest the three principle factors of stress, i.e., objectives, resources and environment. A qualitative research method based on semi-directed interviews was adopted. The research goal is exploratory. Anchored in an interpretive paradigm, the target follows abductive reasoning. The adopted approach is based on analysis of 40 semi-directed interviews held with alliance managers, directors and consultants. The results of our research show that partners vacillate between convergence and divergence of objectives, between the will to share and to dominate management, between diffusion and retention of knowledge and resources, and finally, between loyalty and opportunism. The strategic alliance demands constant search of a delicate equilibrium threatened notably by aggravation of tensions. In this logic, the strategic alliance is thus a stressed organization and figures among the most stressful events for companies; it is capable of simultaneously activating several stress factors. We find that stress is positive if the adaptations, adjustments and negotiations are successful, but that it is negative in the case of their failure. This study contributes to the research on the dynamics of alliance relationships following a process of negotiations. We thus contribute a clear description of the situation of adaptation of the alliance under a situation of stress. This work presents a conceptual contribution, that of the stressed alliance as well as its different factors of stress. Managerial interest resides in the diagnostic of the situation of stress in alliances
Torrent, Hudson da Silva. "Estimação não-paramétrica e semi-paramétrica de fronteiras de produção". reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2010. http://hdl.handle.net/10183/25786.
There exists a large and growing literature on the specification and estimation of production frontiers and therefore efficiency of production units. In this thesis we focus on deterministic production frontier models, which are based on the assumption that all observed data lie in the technological set. Among the existing statistical models and estimators for deterministic frontiers, a promising approach is that of Martins-Filho and Yao (2007). They propose an estimation procedure that consists of three stages. Their estimator is fairly easy to implement as it involves standard nonparametric procedures. In addition, it has a number of desirable characteristics vis-a-vis traditional deterministic frontier estimators as DEA and FDH. In this thesis we propose three papers that improve the model proposed in Martins-Filho and Yao (2007). In the first paper we improve their estimation procedure by adopting a variant of the local exponential smoothing proposed in Ziegelmann (2002). Our estimator is shown to be consistent and asymptotically normal. In addition, due to local exponential smoothing, potential negativity of conditional variance functions that may hinder the use of Martins-Filho and Yao's estimator is avoided. In the second paper we propose a novel method for estimating production frontiers in only two stages. (Continue). There we show that we can eliminate the second stage of Martins-Filho and Yao as well as of our first paper, where estimation of the same frontier model requires three stages under different versions for the second stage. We study asymptotic properties showing consistency andNirtnin, asymptotic normality of our proposed estimator under standard assumptions. In the third paper we propose a semiparametric variation of the frontier model studied in the second paper. We rewrite that model allowing for estimating the production frontier and efficiency of production units in a multiple input context without suffering the curse of dimensionality. Our approach places that model within the framework of additive models based on assumptions regarding the way inputs combine in production. In particular, we consider the cases of additive and multiplicative inputs, which are widely considered in economic theory and applications. Monte Carlo studies are performed in all papers to shed light on the finite sample properties of the proposed estimators. Furthermore a real data study is carried out in all papers, from which we rank efficiency within a sample of USA Law Enforcement agencies using USA crime data.
Fraysse, Philippe. "Estimation récursive dans certains modèles de déformation". Phd thesis, Université Sciences et Technologies - Bordeaux I, 2013. http://tel.archives-ouvertes.fr/tel-00844393.
Lechartier, Élodie. "Contribution au prognostic de pile à combustible PEMFC basé sur modèle semi-analytique". Thesis, Besançon, 2016. http://www.theses.fr/2016BESA2066/document.
The current environmental concerns lead us to consider alternative solutions. The fuel cell can be one of them with numerous advantages, it presents however weaknesses, especially, its life duration which is too short. Face to this issue, we offer to apply the PHM to the PEMFC. For that, it is necessary to develop the prognostics for this application and the possibility of the on-line implementation on an industrial system. It was chosen to base the approach on a behavioral model in which the knowledge gaps are completed with the use of data. So, the approach proposed here, is hybrid. In this work, the behavioral model is studied on laps of time longer in order to finally introduce a prediction of a thousand of hours. Then, the online implementation on a real system is considered with a genericity and an applicability study. This work proposes a hybrid prognostics approach based on a behavioral model and study its implementation on an industrial system
Chen, Chunxia. "Semi-parametric estimation in Tobit regression models". Kansas State University, 2013. http://hdl.handle.net/2097/15300.
Department of Statistics
Weixing Song
In the classical Tobit regression model, the regression error term is often assumed to have a zero mean normal distribution with unknown variance, and the regression function is assumed to be linear. If the normality assumption is violated, then the commonly used maximum likelihood estimate becomes inconsistent. Moreover, the likelihood function will be very complicated if the regression function is nonlinear even the error density is normal, which makes the maximum likelihood estimation procedure hard to implement. In the full nonparametric setup when both the regression function and the distribution of the error term [epsilon] are unknown, some nonparametric estimators for the regression function has been proposed. Although the assumption of knowing the distribution is strict, it is a widely adopted assumption in Tobit regression literature, and is also confirmed by many empirical studies conducted in the econometric research. In fact, a majority of the relevant research assumes that [epsilon] possesses a normal distribution with mean 0 and unknown standard deviation. In this report, we will try to develop a semi-parametric estimation procedure for the regression function by assuming that the error term follows a distribution from a class of 0-mean symmetric location and scale family. A minimum distance estimation procedure for estimating the parameters in the regression function when it has a specified parametric form is also constructed. Compare with the existing semiparametric and nonparametric methods in the literature, our method would be more efficient in that more information, in particular the knowledge of the distribution of [epsilon], is used. Moreover, the computation is relative inexpensive. Given lots of application does assume that [epsilon] has normal or other known distribution, the current work no doubt provides some more practical tools for statistical inference in Tobit regression model.
Delgado, Carlos Alberto Cardozo. "Semi-parametric generalized log-gamma regression models". Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/45/45133/tde-15032018-185352/.
O objetivo central do trabalho é proporcionar ferramentas estatísticas para modelos de regressão semiparamétricos quando os erros seguem distribução log-gamma generalizada na presença de observações censuradas ou não censuradas. A estimação paramétrica e não paramétrica são realizadas através dos procedimentos Newton - Raphson, escore de Fisher e Backfitting (Gauss - Seidel). As propriedades assintóticas dos estimadores de máxima verossimilhança penalizada são estudadas em forma analítica, bem como através de simulações. Alguns procedimentos de diagnóstico são desenvolvidos, tais como resíduos tipo componente do desvio e resíduo quantílico, bem como medidas de influ\\^encia local sob alguns esquemas usuais de perturbação. Todos procedimentos do presente trabalho são implementados no ambiente computacional R, o pacote sglg é desenvolvido, assim como algumas aplicações a dados reais são apresentadas.
Tran, Quang Dat. "Modèle simplifié pour les chaussées fissurées multicouches". Phd thesis, Ecole des Ponts ParisTech, 2004. http://pastel.archives-ouvertes.fr/pastel-00001026.
Nguyen, Van Hanh. "Modèles de mélange semi-paramétriques et applications aux tests multiples". Phd thesis, Université Paris Sud - Paris XI, 2013. http://tel.archives-ouvertes.fr/tel-00987035.
Mendoza, Chavez Gustavo. "Approche semi-automatique de génération de modèles bielles-et-tirants". Thesis, Paris Est, 2018. http://www.theses.fr/2018PESC1030/document.
Within the field of Reinforced Concrete (RC) structures and more specifically, at the design of non-flexural elements such as corbels, nibs, and deep beams, the rational procedure of conception and justification referred as Strut-and-Tie Method (STM) has shown some advantages over classical algorithms of reinforcement computation based on FE analysis (eg. Wood-Armer or Capra-Maury).The STM remains a suitable alternative for the design of concrete structures presenting either elastic or plastic behaviour whose application framework is well defined in concrete structures’ design codes like the EuroCodes and the AASHTO-LRFD Bridge Design Specifications.Nevertheless, this method has the main inconvenient of requiring a high amount of resources investment in terms of highly experienced personal or in terms of computational capacity for, respectively, its manual application or an automatic approach through topology optimisation.The document proposes a light alternative, in terms of required iterations, to the automation of the STM, which starts from the statement that the resultant struts and ties of a suitable ST model can be distributed according to the direction of the principal stresses, $sigma_{III}$ and $sigma_{I}$ , obtained from a planar or a three-dimensional FE model
Sahoury, Nada. "Reconstruction semi-analytique des paramètres fondamentaux de quelques modèles supersymétriques". Montpellier 2, 2008. http://www.theses.fr/2008MON20238.
My research field is based mainly on Supersymmetry and related phenomenology for colliders. More precisely, I am working on the reconstruction of the minimal supergravity model (mSUGRA) parameters. What we are trying to do is to define new methods by which one can determine the parameters of mSUGRA with a limited number of observables in the case that only few particles will be discovered at colliders. The reconstruction of the mSUGRA parameters relies on the squarks and gluinos cascade decay. By combining the universality condition, the Renormalization Group Equations and the equations of the running squark masses, we obtain analytical relations which allow to calculate the parameters of the model and using a semi- analytical guided fit. The related errors are very comparable to the one obtained by traditional fits. The advantage of this technique is that we use only four input observable parameters unlike fit methods in which fifteen to twenty inputs related to measurable quantities are considered. For instance this method has been tested on the SPS 1a model but it can readily be extended to other cascade decays to help identifying other Supersymmetry breaking mSUGRA models at LHC and ILC
Clertant, Matthieu. "Semi-parametric bayesian model, applications in dose finding studies". Thesis, Paris 6, 2016. http://www.theses.fr/2016PA066230/document.
Phase I clinical trials is an area in which statisticians have much to contribute. For over 30 years, this field has benefited from increasing interest on the part of statisticians and clinicians alike and several methods have been proposed to manage the sequential inclusion of patients to a study. The main purpose is to evaluate the occurrence of dose limiting toxicities for a selected group of patients with, typically, life threatening disease. The goal is to maximize the potential for therapeutic success in a situation where toxic side effects are inevitable and increase with increasing dose. From a range of given doses, we aim to determine the dose with a rate of toxicity as close as possible to some threshold chosen by the investigators. This dose is called the MTD (maximum tolerated dose). The standard situation is where we have a finite range of doses ordered with respect to the probability of toxicity at each dose. In this thesis we introduce a very general approach to modeling the problem - SPM (semi-parametric methods) - and these include a large class of methods. The viewpoint of SPM allows us to see things in, arguably, more relevant terms and to provide answers to questions such as asymptotic behavior. What kind of behavior should we be aiming for? For instance, can we consistently estimate the MTD? How, and under which conditions? Different parametrizations of SPM are considered and studied theoretically and via simulations. The obtained performances are comparable, and often better, to those of currently established methods. We extend the findings to the case of partial ordering in which more than one drug is under study and we do not necessarily know how all drug pairs are ordered. The SPM model structure leans on a hierarchical set-up whereby certain parameters are linearly constrained. The theoretical aspects of this structure are outlined for the case of distributions with discrete support. In this setting the great majority of laws can be easily considered and this enables us to avoid over restrictive specifications than can results in poor behavior
Vuza, Xolisa. "Social and technical issues of IP-based multi-modal semi-synchronous communication: rural telehealth communication in South Africa". Thesis, University of the Western Cape, 2005. http://etd.uwc.ac.za/index.php?module=etd&.
Zakaria, Abdellatif. "La plaine méridionale de Tiznit et ses bordures : étude d'un modèle semi-aride". Université Paris-Est Créteil Val de Marne (UPEC), 1996. http://www.theses.fr/1996PA120032.
Pinel-Sauvagnat, Karen. "Modèle flexible pour la recherche d'information dans des corpus de documents semi-structurés". Toulouse 3, 2005. http://www.theses.fr/2005TOU30071.
Structural information contained in semi-structured documents can be used to focus on relevant information. The aim of Information Retrieval System is then to retrieve relevant information units instead of whole documents. We propose here the XFIRM model (XML Flexible Information Retrieval model), which is based on: (i) a generic data representation model, allowing the modelling of documents having heterogeneous structures; (ii) a flexible query language that allows the expression of users needs according to many precision degrees, by expressing (or not) conditions on the documents structure; (iii) a retrieval model based on a relevance propagation method, which aims at finding the most exhaustive and specific information units answering the query. The interest of our propositions has been shown thanks to the prototype we developed
Tollet, Edouard. "Formation et évolution des galaxies en cosmologie : modèles semi-analytiques et simulations hydrodynamiques". Thesis, Sorbonne Paris Cité, 2018. http://www.theses.fr/2018USPCC179/document.
A galaxy is a complex system since as many phenomena take place at the scale of the interstellar medium, such as supernovae explosions or the activity of supermassive black holes, as interactions between galaxies within groups or clusters, such as tidal or ram pressure stripping, affect and condition the evolution of the galaxy itself as a whole. Because the processes acting in such systems involve a considerable range of times and distances, going from individual stars to entire clusters of galaxies, they modelling constitutes an immense challenge that cannot be met neither by a purely analytical approach nor by solely numerical technics.This thesis, being at the interface between semi-analytical models and the analysis of numerical simulations, focuses on the study of star stripping in satellite galaxies by tidal effects and on the supernovae induced feedback.This manuscript presents, on one hand, an halo occupation model that allows to constrain the stellar mass lost by satellite galaxies since they entered their group or their cluster, and a model of impulsive stripping that predicts the stellar mass ripped out of satellites. The latter is compared, through the halo occupation model, to the observed mass functions of groups and clusters.It exposes, on the other hand, the study of the supernovae feedback implemented in the numerical simulations of the NIHAO project, performed separating the simulated gas into different components and counting the exchanges that take place between them. This allowed for the highlighting of three distinct processes through which supernovae reduce or suppress their star formation
Bordes, Laurent. "Inférence statistique pour des modèles paramétriques et semi-paramétriques : modèles de l'exponentielle multiple, test du Chi-deux, modèles de vie accélérée". Bordeaux 1, 1996. http://www.theses.fr/1996BOR10649.
Amer, Mariam. "Using Semi-Empirical Models For Predicting The Luminescence –Structure Relationships in Near-UV Excited Phosphors Activated with Divalent Europium or Mercury-like Cations". Thesis, Université Clermont Auvergne (2017-2020), 2017. http://www.theses.fr/2017CLFAC069/document.
The most used strategy for the design of new luminescent materials today is based on trial-error methods. However, these methods may often result in consummation of money and time. In this sense, a theoretical model acting as a predictive tool can serve as an alternative strategy. Such models are also studied and used by scientists around the world but they are mostly difficult to use. In this work, two friendly and easy to use semi-empirical theoretical models were proposed as a criterion for designing phosphors integrated in the development of important technologies especially in LED-based lightings and solar cells. These models are: 1) the environmental factor model (EF) based on the dielectric theory of chemical bonding proposed by Philips and 2) the metal to metal charge transfer (MMCT) model by Boutinaud that were both used for the purpose of finding relationships between the structural properties of a material and its luminescence. The EF model was applied on the family of AIBIIPO4 (AI= monovalent cation, BII= divalent cation) compounds doped with Eu2+. It was able to estimate the excitation edge energy and to identify the doping sites within uncertainty of ± 1000 cm-1. It can therefore, be used for the design of new phosphors belonging to this family. In a second part, both models were used to identify the nature of luminescence in Bi3+-doped oxides. For this purpose, a method combining the mentioned models along with the values of the Stokes shift was found reliable. In addition, the method was found useful to explain the change in luminescent properties of YVO4:Bi3+ under high pressure. In the third part, the two models were used to explore the luminescence of Sb3+-doped oxides by analogy with Bi3+. However, the results were not good enough to identify the nature of luminescence in these materials. The reason could be related to the off-centered position of the dopant (Sb3+)