L’étude des diverses causes de la complexité du droit de la commande publique permet de déterminer le niveau minimal inéluctable de complexité à conserver, la complexité restante s’avérant inutile et devant donc être supprimée, ou du moins, aménagée. Plus particulièrement, les causes de la complexité de ce droit proviennent objectivement de la difficile rationalisation de ce dernier. Elles sont quantitatives ou qualitatives. Mais toute cette complexité s’explique surtout subjectivement car ses causes résultent du difficile règlement des conflits d’intérêts par ce droit. En effet, tout d’abord, les objectifs de ce droit sont débattus. Ensuite, la société donne différents points de vue sur ce droit. Enfin, on relève une efficacité amoindrie du droit au juge en matière de commande publique, ce qui nuit aux requérants. Il convient alors d’analyser les multiples voies et moyens de simplification du droit de la commande publique afin de trouver le niveau maximal inéluctable de simplification. Dès lors, le reste de la simplification s’avère inutile, infaisable. Ces voies et moyens doivent servir à mieux rationaliser ce droit selon deux approches, l’une quantitative et l’autre qualitative. Cependant, toute cette simplification du droit de la commande publique doit être effectuée surtout d’un point de vue subjectif. Plus précisément, les voies et moyens de cette simplification doivent permettre de mieux régler les conflits d’intérêts. En effet, on peut clarifier les objectifs du droit de la commande publique, réglementer de façon mesurée les divers points de vue de la société sur ce droit et renforcer l’efficacité du droit au juge pour les requérants. / The study of the various causes of the complexity of public procurement law determine the minimum unavoidable level of complexity to keep, the remaining complexity is useless and must therefore be abolished, or at least, modified. More specifically, the causes of the complexity of this law objectively come to the difficult rationalization of the latter. They are quantitative or qualitative. But all this complexity is mainly because subjectively its causes result from the difficult settlement of conflicts of interest by that law. Indeed, first, the objectives of this law are discussed. Then, the society gives different points of view on this law. Finally, we note a diminished effectiveness of the right to a judge in matters of public procurement, which affects the applicants. It is then necessary to analyze the multiple ways and means of simplification of public procurement law in order to find the maximum unavoidable level of simplification. Therefore, the rest of the simplification is unnecessary, infeasible. These ways and means should be used to better rationalize this law according to two approaches, one quantitative and the other qualitative. However, any simplification of public procurement law must be made primarily from a subjective point of view. More specifically, ways and means of this simplification must allow to better resolve conflicts of interest. Indeed, one can clarify the objectives of public procurement law, regulate in a measured way the diverse points of view of society on this law and strengthen the effectiveness of the right to a judge for the applicants.

Mesh simplification is an important task in Computer Graphics due to the ever increasing complexity of polygonal geometric models. Specifically in real-time rendering, there is a necessity that these models, which can be acquired through 3D scanning or through artistic conception, have to be simplified or optimized to be rendered on today's hardware while losing as little detail as possible. This thesis proposes a mesh simplification algorithm that works by identifying and simplifying features. Then it simplifies the remaining mesh with the simplified features frozen. The algorithm is called Quadric Error with Feature Curves (QEFC). Quadric Error with Feature Curves works as a tool that allows the user to interactively select a percentage of the most important points of the feature curves to be preserved along with the points determined by the Quadric Error Metric algorithm.

La simplification du droit se traduit aujourd’hui par une politique volontariste mise en place par les pouvoirs publics qui se concrétise particulièrement par le biais de lois de simplification du droit. Cette politique cherche donc à réduire la complexité du droit a posteriori car elle vise à réécrire la législation et la réglementation existantes. Toutefois, il est possible, eu égard à la finalité de cette politique – l’amélioration de la qualité du droit –, d’envisager une acception originale de la simplification du droit consistant à prévenir la complexité du droit a priori, au stade de l’écriture du droit.Différents acteurs vont concourir à la réalisation de la simplification du droit. Parmi eux, une seule institution dispose de nombreux moyens pour en être la cheville ouvrière : le Conseil d’État. En effet, eu égard à la spécificité de ses attributions (dualité fonctionnelle, rôle de proposition, etc.) et à la place qu’il occupe au sein des institutions (en tant qu’institution mais aussi par le biais de ses membres qui irriguent les sphères décisionnelles), le Conseil d’État est un acteur de premier plan de la simplification du droit.Lorsque celle-ci est envisagée comme une politique volontariste des pouvoirs publics, le Conseil d’État joue un rôle central. D’une part, bénéficiant de l’expérience qu’il a acquise dans les travaux simplificateurs antérieurs à cette politique et par la place que ses membres occupent dans des structures qui concourent à la réalisation de cette politique, le Conseil d’État prend une part active dans la politique de simplification du droit. D’autre part, le choix initialement retenu de la simplification du droit par voie d’ordonnances lui a offert une place importante car les modalités de l’intervention du Conseil d’État sont nombreuses. En 2008, l’introduction dans la Constitution de la possibilité de solliciter l’avis du Conseil d’État sur les propositions de loi a permis à celui-ci de se replacer au cœur de la politique de simplification du droit. Toutefois, le rôle de l’institution est ambivalent. En effet, alors même qu’il influence le contenu des textes de simplification, le Conseil d’État porte des regards contradictoires sur cette politique publique.A l’égard de la seconde acception de la simplification du droit – la prévention de la complexité du droit –, l’effectivité de l’intervention du Conseil d’État est différente. Dans le cadre de la fonction consultative, alors même qu’il dispose de moyens efficaces pour prévenir la complexité du droit, le Conseil d’État n’est pas en définitive décisionnaire, et la complexité des procédures de décisions limite l’importance de son action. Dans le cadre de la fonction juridictionnelle, les interprétations et les règles jurisprudentielles tendent à accentuer la complexité du droit, ce qui soulève la question de l’amélioration de la qualité de la rédaction des décisions du Conseil d’État. / The simplification of law is expressed today by a voluntarist policy implemented by the public Authorities and it is particularly materialized by means of laws tending to simplify law. This policy thus aims at reducing the intricacy of law a posteriori because it aims at re-writing the existing legislation and regulation. However, it is possible, considering the purpose of this policy – the improvement of the quality of law -, to think of an original meaning of the simplification of law consisting in anticipating the intricacy of law a priori, at the level of the writing of law.Different actors are going to work towards the achievement of the simplification of law. Among them, only one institution has at its disposal many means to be the mainspring of it : the Council of State. Because, considering the specificity of its attributions (functional duality, role of proposal, etc…) and the place it occupies within the institutions (as institution but also by means of its members who irrigate the decision-making spheres) the Council of State is a key actor for the simplification of law.When this latter is considered as a voluntarist policy of the public Authorities, the Council of State plays an essential part. On the one hand, taking advantage of the experience it has acquired in the simplifying works priori to this policy and by the place its members occupy in some structures that work towards the achievement of this policy, the Council of State plays an active part in the policy of simplification of law. On the other hand, the initial choice of the simplification of law by edicts has offered the Council of State a significant place because the modes of the state intervention are numerous. In 2008, the insertion into the constitution of the possibility of asking the opinion of the Council of State about the private bills has entitled the latter to replace itself within the policy of simplification of law. However the role of the institution is ambivalent. Because, even though it influences the content of the texts of simplification, the Council of State has contradictory views on this public policy. Considering the second meaning of the simplification of law, the anticipation of the intricacy of law, the efficiency of the intervention of the Council of State is different. Within the framework of the consultative function, whereas it has efficient means to anticipate the intricacy of law, the Council of State eventually has no decision-making power and the intricacy of the procedures of decisions limits the significance of its action. Within the juridictional frame, the interpretation of the judicial precedents tend to emphasize the intricacy of law, which raises the question of the improvement of the quality of the writing of the Council of State decisions.

Dans cette thèse, nous présentons des méthodes pour construire une surface géologique optimal à partir d’une quantité énorme de points 3D extraits de cubes sismiques. Appliquer le processus à l’ensemble des points induit un risque important de contraction de la surface de sorte que l’extraction de la frontière initiale est une étape importante permettant une simplification à l’intérieur de la surface. La forme globale de la surface sera alors mieux respectée pour la reconstruction de la surface triangulaire finale. Nos propositions sont basées sur la régularité des données qui permet, même si des données sont manquantes, d’obtenir facilement les informations de voisinage. Tout d’abord, nous présentons une nouvelle méthode pour extraire et simplifier la frontière d’une surface d’élévation définie par un ensemble de voxels dans un grand volume 3D où des données sont manquantes. Deuxièmement, une méthode pour simplifier la surface à l’intérieur de sa frontière est présentée. Elle comprend une étape de simplification grossière optionnelle suivie par une étape plus fine basée sur l’étude des courbures. Nous tenons également compte du fait que la densité de données doit changer graduellement afin de recevoir à la dernière étape d’une surface triangulée avec de meilleurs triangles. Troisièmement, nous avons proposé une nouvelle méthode rapide pour trianguler la surface après simplification. / Reconstructing surfaces with data coming from an automatic acquisition technique always entails the problem of mass of data. This implies that the usual processes cannot be applied directly. Therefore, it leads to a mandatory data reduction process. An effective algorithm for a rapid processing while keeping the original model is a valuable tool for constructing an optimal surface and managing the complex data.In this dissertation, we present methods for building an optimal geological surface from a huge amount of 3D points extracted from seismic cubes. Applying the process to the whole set of points induces an important risk of surface shrinking so that the initial boundary extraction is an important step permitting a simplification inside the surface. The global surface shape will then be better kept for the reconstruction of the final triangular surface. Our proposals are based on the regularity of data which permits, even if data are missing, to easily obtain the neighboring information. Firstly, we present a new method to extract and simplify the boundary of an elevation surface given as voxels in a large 3D volume having the characteristics to be sparse. Secondly, a method for simplifying the surface inside its boundary is presented with a rough optional simplification step followed by a finer one based on curvatures. We also keep into consideration that the density of data must gradually change in order to receive in the last step a triangulated surface with better triangles. Thirdly, we have proposed a new and fast method for triangulating the surface after simplification.

No description available.

This thesis proposes several new predictors for the compression of shapes, volumes and animations. To compress frames in triangle-mesh animations with fixed connectivity, we introduce the ELP (Extended Lorenzo Predictor) and the Replica predictors that extrapolate the position of each vertex in frame $i$ from the position of each vertex in frame $i-1$ and from the position of its neighbors in both frames. For lossy compression we have combined these predictors with a segmentation of the animation into clips and a synchronized simplification of all frames in a clip. To compress 2D and 3D static or animated scalar fields sampled on a regular grid, we introduce the Lorenzo predictor well suited for scanline traversal and the family of Spectral predictors that accommodate any traversal and predict a sample value from known samples in a small neighborhood. Finally, to support the compressed streaming of isosurface animations, we have developed an approach that identifies all node-values needed to compute a given isosurface and encodes the unknown values using our Spectral predictor.

No description available.

During the 1990s a large-scale study of Port Phillip Bay, Australia, was undertaken by the CSIRO (the Commonwealth Scientific and Industrial Research Organisation, Australia's national research body). A major outcome of the study was a complex ecosystem model intended to provide scientific input into management decisions concerning the nutrient load to the bay. However, its development was costly and time-consuming. Given this effort, it is natural to seek smaller models (reduced models) that reproduce the performance measures of the large model (the full model) that are of interest to decision makers. This thesis is concerned with identifying such models. More generally, this thesis is concerned with developing methods for identifying these smaller models. Several methods are developed for this purpose, each simplifying the full model in different ways. In particular, methods are proposed for aggregating state variables, setting state variables to constants, simplifying links in the ecological network, and eliminating rates from the full model. Moreover, the methods can be implemented automatically, so that they are transferable to other ecological modelling situations, and so that the reduced models are obtained objectively. In the case of the Port Phillip Bay model, significant reduction in model complexity is possible even when estimates of all the performance measures are of interest. Thus, this model is unnecessarily complex. Furthermore, the most significant reductions in complexity occur when the methods are combined. With this in mind, a procedure for combining the methods is proposed that can be implemented for any ecological model with a large number of components. Aside from generating reduced models, the process of applying the methods reveals insights into the mechanisms built into the system. Such insights highlight the extent to which the model simplification process can be applied. Given the effectiveness of the model simplification process developed here, it is concluded that this process should be more routinely applied to large ecosystem models. In some cases, the full sequence of methods might prove too computationally expensive to justify its purpose. However, it is shown that even the application of a subset of the methods can yield both simpler models and insight into the structure and behaviour of the system being modelled.

Tsunoda et al. (2001) recently studied the nature of object representation in monkey inferotemporal cortex using a combination of optical imaging and extracellular recordings. In particular, they examined IT neuron responses to complex natural objects and "simplified" versions thereof. In that study, in 42% of the cases, optical imaging revealed a decrease in the number of activation patches in IT as stimuli were "simplified". However, in 58% of the cases, "simplification" of the stimuli actually led to the appearance of additional activation patches in IT. Based on these results, the authors propose a scheme in which an object is represented by combinations of active and inactive columns coding for individual features. We examine the patterns of activation caused by the same stimuli as used by Tsunoda et al. in our model of object recognition in cortex (Riesenhuber 99). We find that object-tuned units can show a pattern of appearance and disappearance of features identical to the experiment. Thus, the data of Tsunoda et al. appear to be in quantitative agreement with a simple object-based representation in which an object's identity is coded by its similarities to reference objects. Moreover, the agreement of simulations and experiment suggests that the simplification procedure used by Tsunoda (2001) is not necessarily an accurate method to determine neuronal tuning.

This study examines the effects of single word modification on the perceived comprehension of individual sentences. A test was created by randomly selecting sentences from a college level American history textbook. Each sentence was analyzed using Nation's Range program, and the lowest frequency verbs were selected for modification. Each target verb was simplified (replaced with a higher frequency equivalent) or elaborated (left in the sentence, but followed by a parenthetical definition). Subjects received both treatment types and unmodified control items in a fifty-sentence test. Each sentence was rated by the subjects, as it was read, according to the amount of information the subject felt they comprehended. Results indicated no statistically significant difference in the comprehension ratings for simplified, elaborated or unmodified items. However, some trends were evident, indicating the possibility of effects that might become apparent with further study.