Dissertationen zum Thema „Recherche de diversité“
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Kuoman, Mamani Christian Antonio. „Diversité par clustering pour la recherche d'images : étude expérimentale“. Thesis, Paris 6, 2015. http://www.theses.fr/2015PA066361/document.
Der volle Inhalt der QuelleConventional search engines return relevant results but often the retrieved items are similar. Moreover, the similar results tend to appear together. The user may be interested to find documents that are relevant and diverse at the same time.In this thesis, we consider the problem of the diversity in image retrieval. We have focused our attention on diversity by clustering, especially in an approach based on an agglomerative hierarchical clustering (AHC) to address the hierarchical nature of the diversity. Furthermore, we propose a novel approach for exploiting richer description resources, such as a «tree of concepts», to increase the diversity.The different approaches are compared on a highly relevant and manually annotated benchmark: the XiloDiv benchmark; and on the most general: ImageClef2008 and MediaEval2013 benchmarks. The experimental results show that a hierarchical exploitation of the results of the AHC increases the diversity in comparison with two flat clustering methods and a method of diversity by optimization. The results also show that it is better to use concept features than visual features from a diversity point of view. In addition, on the Mediaeval2013 benchmark, we show that an interesting strategy to improve diversity is to increase the relevance using the text, and then to exploit visual based clustering to diversify the results.Finally, we developed a complete prototype in particular taking into account the strong constraints of response time which makes it suitable to be used in the company's search engine
Kuoman, Mamani Christian Antonio. „Diversité par clustering pour la recherche d'images : étude expérimentale“. Electronic Thesis or Diss., Paris 6, 2015. http://www.theses.fr/2015PA066361.
Der volle Inhalt der QuelleConventional search engines return relevant results but often the retrieved items are similar. Moreover, the similar results tend to appear together. The user may be interested to find documents that are relevant and diverse at the same time.In this thesis, we consider the problem of the diversity in image retrieval. We have focused our attention on diversity by clustering, especially in an approach based on an agglomerative hierarchical clustering (AHC) to address the hierarchical nature of the diversity. Furthermore, we propose a novel approach for exploiting richer description resources, such as a «tree of concepts», to increase the diversity.The different approaches are compared on a highly relevant and manually annotated benchmark: the XiloDiv benchmark; and on the most general: ImageClef2008 and MediaEval2013 benchmarks. The experimental results show that a hierarchical exploitation of the results of the AHC increases the diversity in comparison with two flat clustering methods and a method of diversity by optimization. The results also show that it is better to use concept features than visual features from a diversity point of view. In addition, on the Mediaeval2013 benchmark, we show that an interesting strategy to improve diversity is to increase the relevance using the text, and then to exploit visual based clustering to diversify the results.Finally, we developed a complete prototype in particular taking into account the strong constraints of response time which makes it suitable to be used in the company's search engine
Badache, Ismail. „Recherche d'information sociale : exploitation des signaux sociaux pour améliorer la recherche d'information“. Thesis, Toulouse 3, 2016. http://www.theses.fr/2016TOU30038/document.
Der volle Inhalt der QuelleOur work is in the context of social information retrieval (SIR) and focuses on the exploitation of user-generated content in the process of seeking information. The Usergenerated content, or UGC, refers to a set of data (eg. social signals) whose content is mainly produced either directly influenced by end users. It is opposed to the traditional content produced, sold or distributed by professionals. The term became popular since 2005, in the Web 2.0 environments and in new social media. This movement reflects the democratization of the means of production and interaction in the web thanks to new technologies. Among these means more and more accessible to a wide public, we can cite social networks, blogs, microblogs, wikis, etc. The majority of information retrieval (IR) systems exploit two classes of features to rank documents in response to user's query. The first class, the most used one, is querydependent, which includes features corresponding to particular statistics of query terms such as term frequency, and term distribution within a document or in the collection of documents. The second class, referred to as documents prior, corresponds to queryindependent features such as the number of incoming links to a document, PageRank, topical locality, presence of URL, document authors, etc. One of the important sources which can also be used to measure the a priori interest of Web resources is social data (signals) associated with Web resource resulting from user interaction with this resource. These interactions representing annotations, comments or votes, produce useful and interesting social information that characterizes a resource in terms of popularity and reputation. Major search engines integrate social signals (e.g. Google, Bing). Searchmetrics1 showed that it exists a high correlation between social signals and the rankings provided by search engines such Google. We propose an approach that exploits social signals generated by users on the resources to estimate a priori relevance of a resource. This a priori knowledge is combined with topical relevance modeled by a language modeling (LM) approach. We also hypothesize that signals are time-dependent, the date when the user action has happened is important to distinguish between recent and old signals. Therefore, we assume that the recency of signals may indicate some recent interests to the resource, which may improve the a priori relevance of document. Secondly, number of signals of a resource depends on the resource age. Generally, an old resource may have much more signals than a recent one. We introduce the time-aware social approach that incorporates temporal characteristics of users' actions as prior in the retrieval model. Precisely, instead of assuming uniform document priors in this retrieval model, we assign document priors based on the signals associated to that document biased by both the creation date of the signals and the age of the document
Fortune, Emmmanuelle. „Croissance endogène, accumulation créatrice et diversité technologique“. Nice, 2004. http://www.theses.fr/2004NICE0056.
Der volle Inhalt der QuelleThe incorporation of various aspects of innovation in endogenous growth models results in providing a rich technological change analysis and its consequences on the economic activity. This thesis synthesizes the innovation representation in endogenous growth models and adds to the literature with a broader representation. The analysis is carried out within the endogenous growth framework founded on innovation in which the research and development are carried out by private firms moved by the profit coming from patents. The first three chapters offer at the same time an empirical and a theoretical vision of the innovation process coming from the nature of innovation (chapter 1), the research and development activities (chapter 2) and the impact of market structures on innovation incentives (chapter 3). Lastly, an endogenous growth model (chapter 4) shows a cyclical growth and sectoral differences thanks to a creative accumulation which generates a technological diversity, technologies being able to be ex post general purpose technologies or not
Segura, Jordane. „Animaux et droit : de la diversité des protections à la recherche d'un statut“. Nancy 2, 2006. http://www.theses.fr/2006NAN20007.
Der volle Inhalt der QuelleAnimals are animated beings with whom men built very former relations which strongly evolved during time: hunted or protected wild animal, pet, animal object of scientific experiments or closed in intensive animal production, cherished pet. . . In law, animal brings to two major problems: one is the progressive and cumulative diversification of anthropocentric animals protections and the other, more recent, is the research of systemic animals protections. In these two problems, the animal can not be considered as a unique entity: animal reign is really not a single unit. The diversity that identifies it came to a plurality of animals' legal protections and makes necessary a precise analyze of the legal condition of animals – in plural – and not of the animal as a single being. Initially oriented towards man protection, these anthropocentric protections aimed to protect the animal-thing, object of property, the pet, object of human sensibility and the wild animal, object of regulating regimes. These various protections, pursuing varied ends and aiming at different animals, organized in the French Legal Order, then also in the European Union, the Council of Europe and the International Legal Order, have been accumulated and added up. Gradually, other protective measures overlapped in the more former norms. These recent measures of legal protection aimed at animals for themselves and to ensure that animals' welfare is respected. Today, they tend to the call-in question of the initial and residual reification of animals. After long centuries being closed in the legal category of things, furniture or buildings, would it not be relevant to confer them right now a status sui generis corresponding in their specific characteristics?
Montello-França, Léandro. „La question de la diversité et la recherche d'une mesure du bien-être“. Paris 1, 2003. http://www.theses.fr/2003PA010041.
Der volle Inhalt der QuelleYousef, Mohamad Khalil. „Diversité génétique des souches de chlamydophila pecorum : recherche et identification des marqueurs épidémiologiques“. Thesis, Tours, 2009. http://www.theses.fr/2009TOUR4012/document.
Der volle Inhalt der QuelleChlamydophila pecorum, an obligate intracellular bacterium belonged to Chlamydiaceae family. Screening of a genomic DNA library of C. pecorum by using a specific ovine serum, allowed to identify inclusion membrane protein (IncA) as a potential candidate for C. pecorum serodiagnosis and to highlight a coding tandem repeat (CTR) rich in alanine and proline in the C. pecorum incA gene. The CTR presents several amino acids motifs according to the pathogenesis of C. pecorum strains. The genetic variability of 19 C. pecorum strains isolated from ruminants was studied using MVLST (multi-virulence sequence typing) system. The genes ompA that code for the major outer membrane protein, incA and ORF663 (open reading frame) allowed to distinguish the pathogenic C. pecorum strains from non-pathogenic strains. This hypothesis was confirmed on additional 32 strains including 11 strains isolated from swine. The C. pecorum strains isolated from clinical cases are genetically different from strains isolated from healthy animals. ompA, incA and ORF663 genes are epidemiological molecular markers which could be related to the virulence of C. pecorum
Roudel, Mathieu. „Diversité génétique et recherche de facteurs de virulence de Nosema ceranae, parasite de l'abeille mellifère“. Phd thesis, Université Blaise Pascal - Clermont-Ferrand II, 2013. http://tel.archives-ouvertes.fr/tel-00959521.
Der volle Inhalt der QuelleRodriguez, Lily. „Diversité et modes de reproduction du peuplement d'anoures de Cocha Cashu (parc national Manu, Pérou)“. Paris 6, 1991. http://www.theses.fr/1991PA066312.
Der volle Inhalt der QuelleKohi, N'Goran Jeanne Andi. „Contribution à l'étude génétique du cacaoyer par les marqueurs moléculaires : diversité génétique et recherche de QTLs“. Montpellier 2, 1994. http://www.theses.fr/1994MON20159.
Der volle Inhalt der QuelleKollia, Aikaterini. „Analyse statistique de la diversité en anthropometrie tridimensionnelle“. Thesis, Lyon, 2016. http://www.theses.fr/2016EMSE0812.
Der volle Inhalt der QuelleAnthropometry is the scientific field that studies human body dimensions (from the greek άνθρωπος (human) + μέτρον (measure)). Anthropometrical analysis is based actually on 1D measurements (head circumference, length, etc). However, the body’s morphological complexity requires 3D analysis. This is possible due to recent progress of 3D scanners. The objective of this study is to compare population’s anthropometry and use results to adapt sporting goods to user’s morphology. For this purpose, 3D worldwide measurement campaigns were realized and automated treatment algorithms were created in order to analyze the subjects’ point cloud. Based on image processing methods and on shape geometry, these algorithms detect anatomical landmarks, calculate 1D measurements, align subjects and create representative anthropometrical 3D models. In order to analyze morphological characteristics, different statistical methods including components’ analysis, were adapted for use in 3D space. The methods were applied in three body parts: the foot, the head and the bust. The morphological differences between and inside the populations were studied. For example, the difference in each point of the head, between Chinese and European head, was calculated. The statistics in three dimensions, permitted also to show the asymmetry of the head. The method to create anthropometrical models is more adapted to our applications than the methods used in the literature. The analysis in three dimensions, can give results that they are not visible from 1D analyses. The knowledge of this thesis is used for the conception of different products that they are sold in DECATHLON stores around the world
Muret, Arnaud. „La qualité en recherche : la construction d'une norme Française“. Phd thesis, École Nationale Supérieure des Mines de Paris, 2003. http://pastel.archives-ouvertes.fr/pastel-00001249.
Der volle Inhalt der QuelleBois, Rémi. „Hypergraphes multimédias dirigés navigables, construction et exploitation“. Thesis, Rennes 1, 2017. http://www.theses.fr/2017REN1S107/document.
Der volle Inhalt der QuelleThis thesis studies the structuring and exploration of news collections. While its main focus is on natural language processing and multimedia retrieval, it also deals with social studies through the study of the production of news and ergonomy through the conduct of user tests. The task of hyperlinking, which was recently put forward by the multimedia retrieval community, is at the center of this thesis. Hyperlinking consists in automatically finding relevant links between multimedia segments. We apply this concept to whole news collections, resulting in the creation of a hypergraph, and study the topological properties and their influence on the explorability of the resulting structure. In this thesis, we provide improvements beyond the state of the art along three main {axes:} a structuring of news collections by means of mutli-sources and multimodal graphs based on the creation of inter-document links, its association with a large diversity of links allowing to represent the variety of interests that different users may have, and a typing of the created links in order to make the nature of the relation between two documents explicit. Extensive user studies confirm the interest of the methods developped in this thesis
Parrot, Delphine. „Etude de quatre lichens marins, maritime ou terrestre et des bactéries associées : Evaluation de la diversité bactérienne et recherche de métabolites d’intérêt“. Thesis, Rennes, INSA, 2014. http://www.theses.fr/2014ISAR0018/document.
Der volle Inhalt der QuelleEfficiency of currently used antibiotics is worldwide decreasing at a worrying rate, while we are faced with new and emerging pathogens. The majority of active natural products are isolated from the Ascomycetes or from the Actinobacteria. Among the 10000 known antibiotics, more than half are produced by bacteria of one single genus, Streptomyces. It is therefore most interesting to search for novel active molecules in yet under explored niches, such as mutualistic microbial symbioses. Lichens are complex organisms harboring bacterial communities on the surface and, more rarely, inside their thalli and present a model to discover new biomolecules. Optimization of extraction conditions of lichens has been developed. Chemical profiling by LC / MS of nine lichens (2 green algae Roccella fuciformis and R. phycopsis and 7 cyanolichens: Lichina confinis, L. pygmaea, Leptogium lichenoides, Synalissa symphorea, Collema auriforme, C. cristatum and C. fuscovirens) were made and compared with a "Molecular network" approach. This has allowed to identify the chemical similarity between all cyanolichens and between two lichen species containing green algae. On the other hand, further chemical study on R. fuciformis and R. phycopsis was conducted and ten different compounds were isolated. Nine of them have been isolated and identified by NMR and mass fragmentation pathways have been highlighted for five of them. In situ localization of their major respective metabolites (erythrin and roccellic acid for R. phycopsis and erythrin, lepraric acid and acetylportentol for R. fuciformis) was performed and showed a specific location in the lichen thallus. We focused also on the cultivable bacterial communities associated to three lichens from Brittany coast (France) (Roccella fuciformis, Lichina confinis, L. pygmaea) and one inland lichen from Austria (Collema auriforme) to find new secondary metabolites of interest. The abundance and the diversity of the bacterial communities associated to these lichens were showed: 247 strains were isolated and identified by 16S rRNA gene analysis. More than 30% of all strains express potential bioactive compounds and 12% represent probably new species. The secondary metabolites patterns of their cultivable associated bacteria were studied (MOLA1488, Streptomyces sp. and MOLA1416, Hoeflea sp.) and some active secondary metabolites were isolated (e.g. dicetopiperazines, pyrrole alkaloïds, phenoxazine derivatives …) showing biological properties. Finally, to highlight potential interactions between lichens and their associated bacteria, an approach of culture (lichen extracts and bacteria) was performed from 4 most abundant bacterial strains associated with Roccella fuciformis to (1) assess the impact of major metabolites (compounds 4) of this lichen on the growth of these four strains by a an optimized method of viability using MTT; and also to evaluate (2) the ability to bioconversion of these four strains of lepraric acid and erythrin. These bacteria have shown the ability to metabolize erythrin in orsellinic acid, but none of the four tested metabolites has affected their growth
Perrot, Thomas. „Diversité fonctionnelle des systèmes de détoxication chez les champignons lignolytiques“. Thesis, Université de Lorraine, 2018. http://www.theses.fr/2018LORR0140/document.
Der volle Inhalt der QuelleWood decaying fungi play an important role in the carbon cycle by participating in the recycling of organic matter. In addition to their ability to mineralize lignocellulosic biomass, these organisms have the ability to degrade potentially toxic molecules released during this process. Their detoxification system involves several multigenic families including glutathione transferases. These ubiquitous enzymes are grouped into several classes in the fungal kingdom, some of them are widespread in these fungi. In this context, the main objective of this thesis was to understand the functions of glutathione transferases of the Omega class (GSTOs) extended in Trametes versicolor, a white rot fungus. A biochemical and structural approach was led using nine recombinant proteins. Firstly, enzymatic characterization of these isoforms was performed using synthetic substrates, the obtained results demonstrating a similarity of catalytic properties. Then, using a library of pure molecules and another one of complex mixtures from different forest species, a high throughput screening method was applied to identify potential ligands for these enzymes. The resolution of the three-dimensional structure of three isoforms demonstrated the homodimeric state of these proteins and the involvement of two binding sites in the recognition of these ligands: the H site (present in each monomer) and the L site (at the dimer interface). For example, the isoform TvGSTO3S is able to bind several hydroxybenzophenones in its H site, but also a flavonoid, dihydrowogonin. In this case, this interaction with a natural ligand derived from wild-cherry tree extract was demonstrated by an affinity crystallography approach. On the other hand, co-crystallization experiments detected two molecules of another flavonoid, naringenin, in the L site of the isoform TvGSTO6S. Finally, a specific interaction involving the H and L sites of the isoform TvGSTO2S was demonstrated with oxyresveratrol. Structural analysis revealed that the presence of both configurations of the stilbene in the protein: the trans configuration in the H site and the cis configuration in the L site. Thus, despite partial functional redundancy, this research demonstrated the existence of a specific pattern of interactions for each tested isoform. The expansion of the Omega class could indicate that these enzymes are involved in the adaptation of the fungus in its environment. Indeed, the ligands identified during this work suggest that the "ligandin" properties of TvGSTOs play a role in detoxifying wood degradation products
Barsotti, Vanessa. „Recherche et caractérisation de microorganismes dans les compartiments géologiques profonds“. Phd thesis, Bordeaux 1, 2011. http://tel.archives-ouvertes.fr/tel-00688631.
Der volle Inhalt der QuelleTortajada, Sébastien. „De l'étude du fonctionnement des réseaux trophiques planctoniques des marais de Charente Maritime vers la recherche d'indicateurs“. Phd thesis, Université de La Rochelle, 2011. http://tel.archives-ouvertes.fr/tel-00808599.
Der volle Inhalt der QuelleKante, Moussa. „Diversité des populations de Xanthomonas phaseoli pv. manihotis au Mali et recherche de sources de résistance durables chez le manioc“. Thesis, Montpellier, 2020. http://www.theses.fr/2020MONTG028.
Der volle Inhalt der QuelleThe problem of plant diseases occupies a prominent place in the axes of agronomic research in many countries, especially developing ones, where agriculture is generally the engine of the economy. Despite extensive agronomic research, there is a good deal of crop production which until now seemed to be neglected such as cassava (Manihot esculenta). This culture nowadays occupies the front of a lot of research given its strengths as one of the avenues for convincing solutions to the two major challenges (climate change and food security) in southern countries such as Mali. However, it faces a major parasitic constraint, the vascular bacteriosis of cassava (CBB, for Cassava Bacterial Blight) caused by the gram-negative bacterium Xanthomonas phaseoli pv manihotis (Xpm).In Mali in order to offer a source of diversification to conventional food crops largely dominated by cereals and to promote crops resilient to the effects of climate change, we carried out a socio-agronomic and phytoparasitic study on cassava. This is how we focused on: (i) the socio-economic characteristics of cassava production in 05 of the most important cassava-producing regions; (ii) the biological and genetic knowledge of Xpm on cassava in Mali and elsewhere in Africa (Nigeria and Cameroon) and (iii) the resistance to Xpm of local varieties of cassava widely produced in Mali.A series of survey and prospecting followed by field sampling in Mali, but also in Nigeria and Cameroon have enabled us to collect epidemiological data and obtain a range of plant material symptomatic of CBB. With these data we had better sharpened our reflections and arguments on the use of samples: isolation, bio-molecular characterization, pathogenicity test, MLVA analysis of genetic diversity, varietal screening.Our results denote the presence of CBB in the 03 countries surveyed and specifically allow confirmation of the disease presence status (CBB) in Mali. In this country, the production system remains very vulnerable to pests, dominated by a family approach with a small area (from 0.15 to 2 ha in general) with a long-year use of the same varieties, a majority use of the hand of family work and also exchanges of cuttings between producers from the same village who are in the majority (78% of cases of acquisition of cuttings). The study of the diversity and structure of xpm populations in Mali allows us to assume an endemic presence of the disease in Mali. As for the local varieties cultivated in Mali, they are for the most part sensitive to the most present strains (according to the analysis of the family tree from the MLVA analysis
Octau, Franck. „Exploration d'un grand relevé à Nançay et diversité de la population de pulsars“. Thesis, Orléans, 2017. http://www.theses.fr/2017ORLE2042/document.
Der volle Inhalt der QuelleSince the discovery of the first pulsar in 1967, we know over 2500 pulsars today. Pulsars offer a broad range of studies: from the study of the properties of interstellar medium and of pulsar magnetospheres up to test of gravity in the strong-field regime and the characterisation of the cosmological Gravitation Waves background. This explains why we keep searching pulsars nowadays. After successful detections of new millisecond pulsars in Fermi Large Area Telescope unassociated sources at Nançay, a blind pulsar survey was initiated in 2012 by G. Desvignes. Conducted at 1.4 GHz with short sampling time and narrow frequency channels, the SPAN512 was designed to find fast and distant pulsars within the Galactic plane. We describe the methods to analyse data in order to find new pulsars, thanks to their spin stability or tto their single pulses. We will also describe the current status of the survey and the discoveries, more especially the pulsar discovered during this thesis, PSR J2055+3829, a 2.08 ms pulsar in a black widow system. It will be the opportunity to present the radio timing analysis of this pulsar and, in the same time, we will describe similar studies conducted on the pulsar J1618-3921, a pulsar in an eccentric orbit. Finally, we present some polarisation studies of pulsars in light of a new model, the Decentred Rotating Vector Model (DRVM). We will show that a highly decentred dipole may explain abrupt variations of polarisation profiles
Briant, Olivier. „Étude théorique et numérique du problème de la gestion de la diversité“. Phd thesis, Grenoble INPG, 2000. http://tel.archives-ouvertes.fr/tel-00004710.
Der volle Inhalt der QuelleNeveu, Julie. „Diversité bactérienne et approche de métagénomique fonctionnelle pour la recherche de nouvelles protéases à partir d'échantillons de sols de déserts“. Paris 11, 2010. http://www.theses.fr/2010PA112275.
Der volle Inhalt der QuelleThis work aims to study the microbial communities in desert soils and some of their biochemical functions. For this purpose, we have used pyrosequencing of the variable V1-V2 regions of 16S ribosomal DNA. The phylogenetic analyses performed on samples of sand from the Gobi Desert, showed a significant diversity and the likely presence of new bacterial groups. It can be noted that the composition of the microbial communities of our samples are similar to each other, and this distribution is unique compared to studies of soil environments. One feature of our samples is the presence of a large proportion of Bacillaceae, usually found in small amounts in other soil bacterial communities. We also used functional metagenomic methods to uncover biochemical functions without sequence bias. Ln addition, deserts are environments characterized by large temperature variations and low availability of water. We therefore sought to isolate enzymes of protease class, as desert bacteria have not been examined for this type of enzyme. Currently, very few proteases have been extracted from functional metagenomics studies. Here we demonstrate the isolation of several new proteases and a partial biochemical characterization of two of them displaying biochemical properties, as thermostability and high pH stability
Gélinas, Proulx Andréanne. „Modèles hypothétiques de la compétence et d’une formation interculturelles pour des directions et futures directions d’école de langue française au Canada“. Thèse, Université d'Ottawa / University of Ottawa, 2014. http://hdl.handle.net/10393/30655.
Der volle Inhalt der QuelleCardoso, Priscilla. „Diversité et analyse fonctionnelle des systèmes Rap-Phr du groupe Bacillus cereus“. Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLA010/document.
Der volle Inhalt der QuelleThe Bacillus cereus group of Gram positive spore forming bacteria is comprised by eight species that are able to colonize several ecological niches. The most important species are B. cereus, a ubiquitous soil bacterium and an opportunistic pathogen; B. thuringiensis, an entomopathogen widely used as biopesticide; and B. anthracis, the causative agent of anthrax. Even if they present different phenotypes, they are genetic closely related and their main virulence factors are encoded on plasmids. The infectious cycle of B. thuringiensis in the insect larvae is regulated by the sequential activation of quorum sensing systems from the RNPP family. Among them, the Rap-Phr was extensively studied in B. subtilis but just punctually in B. cereus group species. The Rap-Phr systems were shown to regulate various bacterial processes, including the sporulation. The objective of this study was to analyze the Rap-Phr systems in the B. cereus group, regarding their distribution, location and diversity to achieve an overview of these systems in these bacteria. Moreover, their possible involvement in the control of the sporulation process was predicted based on structural data described for RapH in B. subtilis. The rap genes, always associated with a phr gene, were present in all 49 studied strains with an average of six rap-phr genes per strain and 30% were located on plasmids. Comparison among B. cereus and B. thuringiensis strains revealed that the last one harbors six-fold more plasmid rap-phr system then the former. Moreover, phylogenetic closer strains possess a similar profile of rap-phr genes. Interestingly, 32% of the Rap proteins were predicted to inhibit sporulation and these proteins were preferentially located on plasmids and therefore in B. thuringiensis strains. This prediction was partially validated by sporulation efficiency assays suggesting that residues identified in B. subtilis as involved in the phosphatase activity are conserved but not sufficient to predict the sporulation function. Then, the plasmid-borne Rap63-Phr63 system from pAW63 plasmid of B. thuringiensis HD73 strain was further studied. The Rap63 protein moderately inhibits the sporulation and delays the expression of Spo0A-regulated genes. Rap63 is counteracted by its cognate Phr63 peptide, which mature form corresponds to the C-terminal end of the pro-peptide. Sporulation assays in insect larvae suggest a synergistic activity of Rap63-Phr63 and Rap8-Phr8 (from pHT8_1 of B. thuringiensis HD73 strain) systems on sporulation efficiency. Despite the similarities of Phr63 and Phr8 no cross-talk was found between these two systems, confirming their specificity. Altogether, these results reveal the high diversity of the Rap-Phr systems in the B. cereus group and highlight the relevance of the plasmid-borne systems to cell development. Therefore, the results demonstrated the importance of the plasmids in the adaptation and the survival of these bacteria, especially for B. thuringiensis
Monge, Aurélien. „Création et utilisation de chimiothèques optimisées pour la recherche in silico de nouveaux composés bioactifs“. Phd thesis, Université d'Orléans, 2006. http://tel.archives-ouvertes.fr/tel-00122995.
Der volle Inhalt der QuelleIdéalement la préparation des composés destinés au criblage devrait se faire grâce à un logiciel dédié à cette problématique. Il n'existe cependant aucun logiciel qui soit complètement adapté. Nous avons donc entrepris le développement d'un logiciel de ce type : ScreeningAssistant.
Ce logiciel s'appuie sur un système de gestion de bases de données et permet de créer et de maintenir à jour des chimiothèques de plusieurs millions de molécules uniques provenant de fournisseurs différents. Il permet également de filtrer les structures, en éliminant les molécules potentiellement problématiques ou avec des probabilités d'activités faibles, et de sélectionner un ensemble de composés divers.
Ce logiciel a été utilisé pour l'analyse d'une base de 5 millions de références provenant de 38 fournisseurs de produits chimiques. La proportion de composés uniques, originaux, « drug-like », « lead-like », et divers ont été comparés. La diversité a été étudiée en utilisant des notions différentes, et un score de diversité globale, prenant en compte la diversité suivant les différents critères, a été proposé.
Différentes applications de sélection de composés pour le criblage sont présentées. Ces applications utilisent le programme ScreeningAssistant et d'autres algorithmes développés pour résoudre certains problèmes particuliers.
Duboeuf, Patrick. „Diversité et confrontation intergénérationnelle dans la construction du sens : comprendre la Perception et le management de la reconnaissance au sein les laboratoires de recherche“. Thesis, Montpellier 3, 2011. http://www.theses.fr/2011MON30009/document.
Der volle Inhalt der QuelleIn the light of the current evolutions of the device of treatment of retirement pensions, to face the ageing of the employees, the action of seniors within organizations becomes a stake in major management. This search aims at the understanding of the specificities of the relation age-activity professional within the framework of the necessary reinstatement / conservation of quinquas with a prospect of organizational efficiency, emptied of any orientation of instrumentalisation of the troops seniors. The consideration of the property to live professional actors, with objectives of organizational results, can be a frame of reflection in sciences of management.The positive representations are a key of a better collective performance of groups of heterogeneous actors in age. This heterogeneousness is the frame of sets of comparison limiting thecommitment of seniors. The understanding of the mechanisms of gratitude of the actors, as value and manager action, is put as a focal point, a source of knowledge. More exactly, this approach tries to answer the question: how the management of the gratitude adapted to seniors will allow them " to play a role " within organizations by their contributory action the collective performance? To bring elements of answer, we analyze the constituent schemas of the representations of referee of more than 50 years old according to the model cognitiviste proposed by Cossette (2004). From the update of the individual schemas linkin grateful entities, seats of gratitude and commitment, we elaborated and analyzed fifteen cognitive maps of researchers and engineers of search, to pull elements of understanding and explanation, by means of thesoftware Decision investigate.The results bring to light at first the types of gratitude received or waited in terms of means and objective. Two units of time of analysis are then proposed. They allow to distinguish and to move closer to the gratitudes of utility and membership within the framework of interactions connected to the situation, of the gratitude of connected to the personal capacities in echos with the age-related specificities. The crossing, between frame of the units of time, the entities and the seats of gratitude, constitutes)a compass for the possible acts of management of gratitude directed seniors
Lagacherie, Michèle. „Diagnostic des systèmes d'élevage en Camargue : leur diversité, leur dynamique au sein du système agraire“. Montpellier 2, 1988. http://www.theses.fr/1988MON20033.
Der volle Inhalt der QuellePlaquin, Héloïse. „Identités culturelles régionales ou autochtones et États unitaires : à la recherche d'une conciliation : les exemples de la Corse en France et du peuple sámi de Norvège“. Rouen, 2016. http://www.theses.fr/2016ROUED011.
Der volle Inhalt der QuelleThe French republic and the Norwegian realm are both unitary States which constitutions assess the principles of indivisibility and equality. In theory, these constitutional norms conflict with minority claims such as regional or indigenous identity, and also with international laws that recognize a right to internal self-determination, to effective participation as well as specific and collective rights. From the inner side, the French and the Norwegian States have both experimented, during the 1980s, political and cultural conflicts with part of Corsica Island and with indigenous sámi people. Since the eighteenth century, Corsican and sámi people have been exposed to cultural, political and juridical domination from the nation-states. As they became key-actors, they, ever since, claim for legal and institutional adaptations from the French and Norwegian unitary States in order to protect, to maintain and to develop their distinctive cultural identities. In addition, local autonomy, cultural diversity, minorities and indigenous rights set forth in recent norms from the United Nations and the Council of Europe lead all involved States, whatever their form, to engage in a process of internal reforms based on dialogues and concertation with their cultural minorities. French and Norwegian legal reforms about Corsica and sámi identities are pursued according to different framework: one is based on territorial decentralization and the other on internal self-determination. However, in practice and through concertation and pragmatically approach, these reforms create dynamic and accommodated State-frameworks taking into account cultural pluralism, and thus enabling (re)conciliation of the French and the Norwegian unitary States with the corsican and sámi identities
Lazrek-Ben, Friha Fatma. „Analyse de la diversité génétique et symbiotique des populations naturelles tunisiennes de Medicago truncatula et recherche de QTL liés au stress salin“. Toulouse 3, 2008. http://thesesups.ups-tlse.fr/384/.
Der volle Inhalt der QuelleThe objective of this thesis is to study genetic diversity within 136 lines belonging to Tunisian 10 natural populations of M. Truncatula. These populations come from different soil and climatic conditions, representative of the Tunisian territory. The first part consists of an analysis at the molecular level by the use of 18 microsatellites spread over different linkage groups. That helped to structure populations depending to a north / south axis separated by the Tunisian Dorsale. The parameter rainfall is the most important factor influencing this structure. Similarly, using morphological markers, we tried to deepen the characterization of populations and to make comparison with that obtained by microsatellites. In the second part, we continued the analysis of the diversity by the study of the variability of a number of lines under nitrogen assimilation or in symbiosis with different strains of Rhizobium, in the presence or absence of salt stress. Based on this analysis, it was possible to select pairs of contrasting lines for their response to salt in those two conditions studied, which have enabled us to identify criteria for salt tolerance. The last part involves a quantitative analysis which aimed primarily to identify markers involved in salt tolerance in the plant partner. . .
Barberousse, Hélène. „Etude de la diversité des algues et des cyanobactéries colonisant les revêtements de façade en France et recherche des facteurs favorisant leur implantation“. Phd thesis, Museum national d'histoire naturelle - MNHN PARIS, 2006. http://tel.archives-ouvertes.fr/tel-00188566.
Der volle Inhalt der QuelleParadoxalement, les algues microscopiques et les cyanobactéries constituant ces biofilms sont peu connues en France. La première approche de ce projet a donc consisté à prélever des fractions de revêtements de façade colonisés afin d'identifier les micro-organismes s'y développant. 22 espèces d'algues et 25 espèces de cyanobactéries ont ainsi été observées dans les 71 prélèvements analysés, les algues étant dominantes sur tous types de matériaux.
Les facteurs favorisant l'implantation et le développement de ces micro-organismes ont ensuite été étudiés. Un traitement statistique des données environnementales recueillies lors de la campagne d'échantillonnage a ainsi mis en évidence l'importance des facteurs climatiques liés à l'humidité, des facteurs permettant la dissémination des spores, tels que le vent ou la proximité de végétation, ainsi que l'importance de la nature du support colonisé. Cette dernière observation a pu être approfondie grâce à l'utilisation d'un banc d'essai permettant l'évaluation simultanée de différents matériaux quant à leur colonisation par des algues et des cyanobactéries isolées en façade au cours de cette étude. Ces essais ont montré que des facteurs tels que la porosité, la rugosité et le pH de surface des matériaux influent sur la colonisation par ces micro-organismes.
En parallèle, afin d'envisager le développement de matériaux défavorisant l'accroche des micro-organismes, les mécanismes d'adhésion d'une sélection d'algues sur des surfaces modèles ont été étudiés à l'aide d'une cellule à flux laminaire. Les surfaces hydrophiles ont provoqué le plus faible taux d'adhésion. L'exploitation de ces résultats a également mis en évidence l'initiation d'interactions hydrophobes et électrostatiques lors du processus d'adhésion.
Finalement, les polymères extracellulaires produits par une sélection de micro-organismes isolés en façade ont été analysés. Ils ont ainsi montré être de nature polysaccharidique, anionique et plus ou moins hydrophobe selon les souches les sécrétant. L'adsorption d'un polymère d'une souche de Klebsormidium flaccidum, algue verte dominante en façades en France, a été plus importante et plus forte sur des surfaces hydrophobes que sur des surfaces hydrophiles. En outre, la dégradation enzymatique des polymères de cette même souche tend à diminuer l'adhésion sur surface hydrophobe. Ces observations confirment donc l'hypothèse d'une intervention des polymères extracellulaires dans l'étape de contact du micro-organisme avec une surface, puis lors de l'étape de consolidation de cette adhésion, par le biais d'interactions hydrophobes et sans doute électrostatiques.
Pérugien, Sabrina. „La construction d'une culture organisationnelle en faveur de la diversité dans l'enseignement supérieur : monographie d'une recherche-intervention menée au sein d'une business school française“. Thesis, Strasbourg, 2015. http://www.theses.fr/2015STRAB004.
Der volle Inhalt der QuelleDespite its classical style, this thesis is highly original in both the subject of the investigation – the strategic integration of diversity into the organizational culture of a French business school – and its results. Focused on the social responsibility of French higher education establishments, this thesis addresses issues that lie at the boundary of strategy and HRM. It targets the institutions that could be called the ‘antechamber’ of the business world, and that produce the next generation of managers: leading business schools. Diversity and non-discrimination at work are recent streams of research in the French managerial literature and this work takes a detailed look at the dynamics of change of a phenomenon that has received little attention: the construction of an organizational culture that fosters diversity. As the emphasis is on ‘organized’ and ‘organizing’ action rather than the institution itself, an intervention research strategy is adopted to investigate ongoing organizational change. This single-domain (monograph), longitudinal and process-based case study was carried out in situ, while Pettigrew’s contextualist approach provided the framework for a detailed description and in-depth analysis
Bravo, Gonzalo. „Analyse de la diversité des exploitations agricoles de la région de Salta (Argentine) pour orienter les actions de recherche et de vulgarisation : proposition méthodologique“. Dijon, 1992. http://www.theses.fr/1992DIJOE009.
Der volle Inhalt der QuelleThe functioning typology of farms which has been elaborated in the Salta region (Nothern Argentine) demonstrates that farmers use coherent technical and economic practices. They manage the various flows crossing their farms in such way as to adapt the functioning of the system to their particular situation, objectives and environment. This helps the needs and the technical choices of farmers to be understood, and therefore research action and development to be specified in addition, the relationships between different types of farms are taken into account with a view. To local development. All of the above constitutes a methodological proposal calling for a pluridisciplinary approach
Ranc, Nicolas. „Analyse du polymorphisme moléculaire de gènes de composantes de la qualité des fruits dans les ressources génétiques sauvages et cultivées de tomate : recherche d'associations gènes/QTL“. Thesis, Montpellier, SupAgro, 2010. http://www.theses.fr/2010NSAM0001/document.
Der volle Inhalt der QuelleIn Tomato (Solanum lycopersicum), breeding for fruit quality is difficult due to the multiplicity and complexity of the traits. QTL mapping has allowed the genetic characterization of these traits. One of the challenges is now to identify the genes underlying these QTLs. Following this aim, we used linkage-disequilibrium (LD) mapping. To avoid hazardous associations between traits and polymorphisms, the genetic structure has to be taken into account for LD mapping. Cultivated tomato showed low genetic diversity reducing mapping resolution. Cherry type tomato genome is described to be admixture between cultivated tomato and its wild ancestor. Such admixture may increase resolution of association mapping. We used a core collection focused on cherry type accessions to validate a candidate gene for a fruit locule-number QTL. We found that two single nucleotide polymorphisms (SNP) were highly associated with the trait. These two SNP evolved differently from the rest of the chromosome 2. They underwent a balanced selection which testifies a selection for fruit morphology diversity by human. Association mapping, focused on whole chromosome 2, allowed us to assess the extent of linkage disequilibrium over genetic and physical distances. Associations of polymorphisms with phenotypes were detected with structured association methods. We thus showed efficiency of genome admixture to overcome the low-resolution limitation of association mapping for an inbred crop. We validated previously identified QTLs and found associations with new QTLs and new candidate genes. An evolutionary model including bottleneck and gene flow between wild and domesticated forms is also presented
Porumbel, Daniel Cosmin. „Algorithmes Heuristiques et Techniques d'Apprentissage : Applications au Problème de Coloration de Graphe“. Phd thesis, Université d'Angers, 2009. http://tel.archives-ouvertes.fr/tel-00476541.
Der volle Inhalt der QuelleCameleyre, Isabelle. „Contribution à l'étude du cycle biologique de la truffe noire du Périgord (Tuber Melanosporum Vitt. ) : analyse de la diversité génétique intraspécifique et recherche des gènes du type sexuel“. Bordeaux 2, 1996. http://www.theses.fr/1996BOR28448.
Der volle Inhalt der QuelleMaizeray, Lidwine. „La gestion de la diversité mise à l'épreuve : le cas du groupe Crédit Agricole SA“. Thesis, Paris 2, 2014. http://www.theses.fr/2014PA020057/document.
Der volle Inhalt der QuelleThe institutional pressure of laws and associations, as well as the search for economic performance, combined with various expectations, create a gap of perception between the idea of an ideal policy and the reality of diversity felt by the actors within their organisation.This gap leads to forms of demotivation and demobilisation, unfavourable to the development of a diversity policy which would claim to be efficient. How could we actually limit the unavoidable slowdown of the diversity management? Once the reasons why the actors of an organisation such as Crédit Agricole S.A. are restrained in developing an inclusive type of diversity management are analysed, this thesis brings tangible solutions to manage diversity in a way which is closer from the actors’ expectations.From a triangulation of data analysis within the framework of a qualitative methodology,inclusion has not necessarily appeared as the actors’ main expectation. Participative observation, the main case study highlighted with 3 complementary cases, 55 interviews (15 about diversity + 40 related to the handicap dimension), allow thus to bring managerial propositions to meet the main expectation of the actors which is the need to dialogue, in the sense of talk. The first step involves identifying the actors likely to be demotivated in order to mobilize them by allowing them to speak again afterwards. Allow them to speak does not necessarily involves setting up formal procedures, but more precisely taking time to exchange, creating a sharing time and thus establishing a better quality of life at the workplace
Van, Frank Gaëlle. „Gestion participative de la diversité cultivée et création de mélanges diversifiés de blé tendre à la ferme“. Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLS525/document.
Der volle Inhalt der QuelleThe transition from a diversified agriculture to a productivist system has led to a decline in cultivated diversity and raises many environmental, societal and health issues. Alternatives such as agro-ecology have emerged, based in particular on the enhancement of agro-biodiversity and genetic diversity within agro-ecosystems. Considering that there are no varieties adapted to their needs in the catalogue, farmers and facilitators from the Réseau Semences Paysannes (RSP) have been conducting a participatory breeding project (PPB) for bread wheat since 2006, in collaboration with the DEAP (Diversity, Evolution and Adaptation of Populations) team at UMR GQE Le Moulon. These farmers are mobilizing diversity to select populations adapted to their practices, terroir and outlets, with the aim of regaining their seed autonomy and a coherence of their system. My thesis focuses on the study of the impacts of collective management and peasant selection practices on wheat crop diversity and population adaptation. It aims to propose possible adaptation of existing PPB practices and to support the implementation of new projects. The impacts of on-farm creation and selection practices of population mixtures on their agronomic and morphological behaviour were evaluated through an experiment in collaboration with about fifteen farmers and facilitators from the RSP. In a second part we studied the impacts of natural selection and peasant selection on the evolution of populations, their stability and adaptation to environments during the wheat PPB project. Then a prospective study on the impacts of the adoption of heterogeneous varieties on cultivated diversity at the landscape level was conducted, by assessing the diversity of populations from PPB, simulating adoption of heterogeneous varieties scenarii and using cultivated diversity indicators. Finally, the impacts of the on-farm experimental design parameters on the adjustment and accuracy of estimates from Bayesian models were assessed, to improve our ability to detect significant differences between populations and to provide recommendations for other decentralized variety evaluation projects using the designs and models developed in the French wheat PPB project
Thieury, Charlotte. „Recherche de composés cytotoxiques dans la biodiversité végétale de la Nouvelle-Calédonie“. Thesis, Nouvelle Calédonie, 2016. http://www.theses.fr/2016NCAL0007.
Der volle Inhalt der QuelleAs old as human consciousness, correspondence between plants and their healing properties is known. An analysis of our pharmacopoeia shows that even now humans seek these drugs in nature. This study on anticancer drugs has focused on valuing nature as a source of new substances named "leads", bioactive compounds that are at the base of drug development.The first part of this study focused on the pharmacomodulation of a natural anticancer molecule from a locally-known plant. 23 flavokawain derivatives (FKD) were synthesized to improve the understanding of the structural requirements necessary for optimal selectivity and cytotoxicity via an SAR study. Six molecules have shown significant improvements in terms of activity and selectivity. The study of their mechanisms of action revealed that FKD induced a variable cell cycle arrest depending on the p53 status of cancer cell lines as well as apoptosis. The action delays of FKD depended of Akt/mTor status of cancer cell lines. The second part of this study focused on the phytochemical exploration of new caledonian endemic plants to discover new sources of cytotoxic molecules. The ccreening of cytotoxic activities helped to highlight interesting activities in Diospyros olen, Meiogyne baillonii and several species of Soulamea. A phytochemistry work led to the isolation of many molecules including three news: sapranthine H and macrocarpasines A and B. Aristolactame BII and elliptinone exhibited strong cytotoxic activity. Aristolactame BII led to a cell cycle arrest depending on the p53 status of cancer cell lines.This valuation work is essential in an objective of protecting an endangered biodiversity like it’s the case in New Caledonia to allow the establishment of backup programs
Khalfaoui, Liece. „Diversité culturelle et innovation organisationnelle en contexte de coopération internationale : le cas d’un Plan de Contrôle Qualité dans un projet international d’infrastructure de transport“. Thesis, Paris Est, 2018. http://www.theses.fr/2018PESC0011.
Der volle Inhalt der QuelleInternational project development teams confront complex technical and organizational situations. The objective of the projects differs from the ordinary production by the uniqueness of the outcome and the inevitable unexpected events which require the resolution of emerging problems during the realization process. The search for solutions leads to innovations. The international context of projects adds cultural diversity to the diversity of the professions and profiles of the members, which means that the actors do not share the same references to give meaning to the situations they live in. For some researchers, cultural diversity within a team promotes creativity and innovation. For others, diversity raises difficulties that slow down the diffusion and realization of innovations. It is only the instrument to construct strategic artificial borders that protect the profits of the actors. This doctoral research is not intended to decide between the various theses but proposes, on the basis of an empirical work in an international context, elements of explanation to the relations between the differences of cultures on one hand, and the ability to generate and spread an organizational innovation on the other hand. This research is based on a single multicultural case study “the Quality Control Plan” in an international transport infrastructure project carried out by a consortium made up of Algerian, French and Italian firms. Our study reveals that examining cultural constructs in relation to power relations, and the articulation of national cultures with professional cultures, is crucial to understand the mechanisms explaining the links between cultural diversity and organizational innovation. Neither the cultures in presence, nor the power relationships are sufficient to explain the dynamics of an organizational innovation process; it is the articulation of these dimensions that plays into the interactions. Our managerial contribution is accentuated by taking into account the socio-cultural contexts of international projects, and reinforcing the formal and legal framework in these inter-organizational linkages
Ayour, Jamal. „Contribution à l'étude de la diversité génétique et recherche des paramètres physicochimiques et biochimiques indicateurs de la qualité au cours de la maturation des fruits d'abricots frais et après transformation“. Thesis, Avignon, 2018. http://www.theses.fr/2018AVIG0704.
Der volle Inhalt der QuelleThe problematic of this thesis is based on the characterization of the quality of apricotsand their aptitude for industrial processing. Three main axes guided this study. The first oneconsisted initially of a global morphometric characterization of Moroccan apricot clonesmaintened in experimental station of INRA of Marrakech and followed by the analysis ofgenetic diversity. 92 accessions, from different geographical regions, were genotyped using21 microsatellite markers. Indeed, the analyzed collection was characterized by a highpolymorphism and a reduced genetic diversity. A total of 120 alleles were identified with anaverage of 5.71 alleles per locus. All the statistical evidence (hierarchical analysis, PCA andstructural analysis) show that the genetic structure of Moroccan apricot can be subdivided intotwo populations : a major population made up of most accessions of genetic groups (authenticpopulation linked in particular to the Delpatriarca variety) and a second less diversifiedpopulation related to all reference varieties, including the Canino variety. The observedvariability between the 92 genotypes could be an asset to improve the apricot cultivation andto allow a sustainable development in the space and the time of the fruit by the selection ofnew genotypes of apricots. Finally, the observed genetic variability was used in the selectionof new apricot clones for phenotypic analysis. The second axis focused on the study ofbiochemical markers that allow to understand and evaluate the quality of selected apricots,namely : the change of organic acids and soluble sugars in relation to the sensory quality, thedevelopment of pigments and color change, the evolution of phenolic compounds in relationto antioxidant activity and loss of texture according to the cell wall biochemistry. Indeed,good physicochemical and biochemical properties have been reported for the ten chosenclones (Maximum values reported for some bioactif compounds : Vitamin C = 0.15 g / kg, β-carotene = 149.251 μg / kg, provitamin A = 0.028 mg / kg), as well as the qualitative traitsassociated with the maturation season and the genotype, is certainly a valuable genetic sourceto extend the apricot season and to supply stalls and industry. The third axis was on theimplication of the texture of the fruit in the industrial processing of apricot. We analyzed thevarietal ability of apricots for industrial processing by analyzing their textural propertiesbefore and after processing. And to better understand the variability of apricot texture, westudied the impact of heat treatment depending on the stage of fruit harvesting on a widerange of French cultivars. In the end, five apricots varieties were chosen as the mostappropriate for the industrial process
Paolo, Giuseppe. „Learning in Sparse Rewards setting through Quality Diversity algorithms“. Electronic Thesis or Diss., Sorbonne université, 2021. http://www.theses.fr/2021SORUS400.
Der volle Inhalt der QuelleEmbodied agents, both natural and artificial, can learn to interact with the environment they are in through a process of trial and error. This process can be formalized through the Reinforcement Learning framework, in which the agent performs an action in the environment and observes its outcome through an observation and a reward signal. It is the reward signal that tells the agent how good the performed action is with respect to the task. This means that the more often a reward is given, the easier it is to improve on the current solution. When this is not the case, and the reward is given sparingly, the agent finds itself in a situation of sparse rewards. This requires a big focus on exploration, that is on testing different things, in order to discover which action, or set of actions leads to the reward. RL agents usually struggle with this. Exploration is the focus of Quality-Diversity methods, a family of evolutionary algorithms that searches for a set of policies whose behaviors are as different as possible, while also improving on their performances. In this thesis, we approach the problem of sparse rewards with these algorithms, and in particular with Novelty Search. This is a method that, contrary to many other Quality-Diversity approaches, does not improve on the performances of the discovered rewards, but only on their diversity. Thanks to this it can quickly explore the whole space of possible policies behaviors. The first part of the thesis focuses on autonomously learning a representation of the search space in which the algorithm evaluates the discovered policies. In this regard, we propose the Task Agnostic eXploration of Outcome spaces through Novelty and Surprise (TAXONS) algorithm. This method learns a low-dimensional representation of the search space in situations in which it is not easy to hand-design said representation. TAXONS has proven effective in three different environments but still requires information on when to capture the observation used to learn the search space. This limitation is addressed by performing a study on multiple ways to encode into the search space information about the whole trajectory of observations generated during a policy evaluation. Among the studied methods, we analyze in particular the mathematical transform called signature and its relevance to build trajectory-level representations. The manuscript continues with the study of a complementary problem to the one addressed by TAXONS: how to focus on the most interesting parts of the search space. Novelty Search is limited by the fact that all information about any reward discovered during the exploration process is ignored. In our second contribution, we introduce the Sparse Reward Exploration via Novelty Search and Emitters (SERENE) algorithm. This method separates the exploration of the search space from the exploitation of the reward through a two-alternating-steps approach. The exploration is performed through Novelty Search, but whenever a reward is discovered, it is exploited by instances of reward-based methods - called emitters - that perform local optimization of the reward. Experiments on different environments show how SERENE can quickly obtain high rewarding solutions without hindering the exploration performances of the method. In our third and final contribution, we combine the two ideas presented with TAXONS and SERENE into a single approach: SERENE augmented TAXONS (STAX). This algorithm can autonomously learn a low-dimensional representation of the search space while quickly optimizing any discovered reward through emitters. Experiments conducted on various environments show how the method can i) learn a representation allowing the discovery of all rewards and ii) quickly [...]
Servajean, Maximilien. „Recommandation diversifiée et distribuée pour les données scientifiques“. Thesis, Montpellier 2, 2014. http://www.theses.fr/2014MON20216/document.
Der volle Inhalt der QuelleIn many fields, novel technologies employed in information acquisition and measurement (e.g. phenotyping automated greenhouses) are at the basis of a phenomenal creation of data. In particular, we focus on two real use cases: plants observations in botany and phenotyping data in biology. Our contributions can be, however, generalized to Web data. In addition to their huge volume, data are also distributed. Indeed, each user stores their data in many heterogeneous sites (e.g. personal computers, servers, cloud); yet he wants to be able to share them. In both use cases, collaborative solutions, including distributed search and recommendation techniques, could benefit to the user.Thus, the global objective of this work is to define a set of techniques enabling sharing and discovery of data in heterogeneous distributed environment, through the use of search and recommendation approaches.For this purpose, search and recommendation allow users to be presented sets of results, or recommendations, that are both relevant to the queries submitted by the users and with respect to their profiles. Diversification techniques allow users to receive results with better novelty while avoiding redundant and repetitive content. By introducing a distance between each result presented to the user, diversity enables to return a broader set of relevant items.However, few works exploit profile diversity, which takes into account the users that share each item. In this work, we show that in some scenarios, considering profile diversity enables a consequent increase in results quality: surveys show that in more than 75% of the cases, users would prefer profile diversity to content diversity.Additionally, in order to address the problems related to data distribution among heterogeneous sites, two approaches are possible. First, P2P networks aim at establishing links between peers (nodes of the network): creating in this way an overlay network, where peers directly connected to a given peer p are known as his neighbors. This overlay is used to process queries submitted by each peer. However, in state of the art solutions, the redundancy of the peers in the various neighborhoods limits the capacity of the system to retrieve relevant items on the network, given the queries submitted by the users. In this work, we show that introducing diversity in the computation of the neighborhood, by increasing the coverage, enables a huge gain in terms of quality. By taking into account diversity, each peer in a given neighborhood has indeed, a higher probability to return different results given a keywords query compared to the other peers in the neighborhood. Whenever a query is submitted by a peer, our approach can retrieve up to three times more relevant items than state of the art solutions.The second category of approaches is called multi-site. Generally, in state of the art multi-sites solutions, the sites are homogeneous and consist in big data centers. In our context, we propose an approach enabling sharing among heterogeneous sites, such as small research teams servers, personal computers or big sites in the cloud. A prototype regrouping all contributions have been developed, with two versions addressing each of the use cases considered in this thesis
Marescot, Vanessa. „Dispositifs pédagogiques innovants à l’université. Diversité méthodologique pour le recueil et l’analyse de l’expérience des usagers : étude du cas NCU PRéLUDE“. Electronic Thesis or Diss., Valenciennes, Université Polytechnique Hauts-de-France, 2023. http://www.theses.fr/2023UPHF0036.
Der volle Inhalt der QuelleThe aim of this doctoral work is to examine the experience of users of innovative teaching methods introduced at university. The various waves of massification of access to higher education have led to a diversification of the student population, whose success has become a priority. There are many factors that determine success, including contextual factors such as teaching practices. As a result, educational and digital transformation is at the heart of various calls for projects aimed at providing financial support for the university's development. The competitive nature of these calls for projects and the emulation they engender give rise to increasingly innovative proposals. At the other end of the chain, those involved implement, experiment with and experience these schemes on the ground. The aim of this research project is to question the players, and in particular the students, about their experience of these educational innovations, as part of the PRéLUDE project, one of the winners of the PIA 3 New University Curricula programme. The research is based on a constructivist, inductive approach. It used a variety of data collection methods: questionnaires, semi-structured interviews, Repertory Grid interviews, supplemented by documentary research and participant observation. These methods produced quantitative and qualitative data, analysed using quantitative and qualitative methods. This methodological diversity makes it possible to analyse the experience of users, thus questioning the design process both in terms of how the ideation is adapted to users and in terms of the actual implementation of the ideal project
Banos, Vincent. „L'hypothétique construction des lieux ordinaires entre agriculteurs et non-agriculteurs en Dordogne : de l'idéologie patrimoniale à la recherche des échappés du territoire“. Phd thesis, Université Paris-Sorbonne - Paris IV, 2008. http://tel.archives-ouvertes.fr/tel-00426652.
Der volle Inhalt der QuelleBanos, Vincent. „L'hypothétique construction des lieux ordinaires entre agriculteurs et non-agriculteurs en Dordogne : de l'idéologie patrimoniale à la recherche des échappés du territoire“. Paris 4, 2008. http://www.theses.fr/2008PA040214.
Der volle Inhalt der QuelleThis research stems from the on-going renegotiation of the social bonds that link farmers to the civil society. This renegotiation is looked at from the angle of the recent opening process that rural areas are going through in the name of patrimonial and environmental interests. We put forward the hypothesis that the publicization of rural areas is not restricted to new uses, but is also an opportunity to turn them to the public sphere. Using a pragmatic and interactionnist interpretation of social bonds, we propose an analytical model based on three topiques of urbanity : open space, public space and place. Those are used as keys to understand how the ordinary social spatialities redefine the modalities of the "vivre-ensemble". This redefinition is not uniform. For this gradual normative inventiveness of social interactions could be due to both the inter-individuality of joint investments and the higher visibility of discourse-building places. The contextual analysis of the requalification processes and the study of the farmers/non-farmers co-presence situations in Dordogne confirm the operationality of the notion of open space. The ladders also stress the ambiguous role of the patrimonialization normative beam in the reinforcing of the public order, as well as the reduction of contested place identity. However, we find the traces of places and ""common worlds" moments, as first potential steps towards the advent of a public sphere. While cultural plurality increases, this reflexion thus aims at clarifying the role of space in the normative processes by emphasizing the everyday social experiences and the importance of conceiving space as a context of action
Abbas, Najwa. „La diversité des toxines de scorpions et leur intérêt dans la recherche biologique et pharmacologique : (purification et caractérisation chimique, pharmacologique et immunologique des toxines de scorpion présentant des problèmes de santé publique au Moyen Orient et leurs implications pharmacologiques)“. Thesis, Aix-Marseille 2, 2010. http://www.theses.fr/2010AIX20705.
Der volle Inhalt der QuelleThe North African scorpion Androctonus australis in Algeria and Tunisia, or Androctonusmauretanicus in Morocco, are responsible of about 100.000 stings each year in Maghreb,followed by 1% of death. Small toxins modulating voltage-gated sodium channels (Nav),named “alpha”, are responsible of 80 to 90% of the total lethal activity from the Androctonusaustralis and mauretanicus venoms. However, smaller molecules are also able to block thefunctioning of another type of ionic channels, in particular, the voltage-gated potassiumchannels (Kv).During this thesis, we have isolated and characterized the compounds of the venom fromAndroctonus amoreuxi, a scorpion widely found in North Africa and Middle East, but neverseriously studied so far. We have identified the constituents implicated in the toxicity anddefined their immunological and pharmacological properties, as well as theirelectrophysiological effects on cloned Nav and Kv channels expressed in Xenopus oocytes.We also have looked for recently characterized new molecules, the Birtoxins-like, and tried toexplain their large biological polymorphism by 3D structural models. At last, we haveevaluated the antinociceptifs effects of scorpion toxins in mice. We have proposed that theantalgic effects observed after administration of scorpion toxins are partly due to a counterirritation phenomenon, which implicates the activation of an endogenous opioid system. The“analgesic” toxins have been further tested in electrophysiology on DRG neurons
Amiour, Nardjis. „Etude biochimique et génétique de la diversité des protéines de réserve du triticale hexaploïde, de leur influence sur les caractéristiques technologiques et recherche de facteurs impliqués dans la dureté du grain par une analyse protéomique des protéines amphiphiles du blé tendre“. Clermont-Ferrand 2, 2002. http://www.theses.fr/2002CLF22348.
Der volle Inhalt der QuelleChenu, Alexandre. „Leveraging sequentiality in Robot Learning : Application of the Divide & Conquer paradigm to Neuro-Evolution and Deep Reinforcement Learning“. Electronic Thesis or Diss., Sorbonne université, 2023. http://www.theses.fr/2023SORUS342.
Der volle Inhalt der Quelle“To succeed, planning alone is insufficient. One must improvise as well.” This quote from Isaac Asimov, founding father of robotics and author of the Three Laws of Robotics, emphasizes the importance of being able to adapt and think on one’s feet to achieve success. Although robots can nowadays resolve highly complex tasks, they still need to gain those crucial adaptability skills to be deployed on a larger scale. Robot Learning uses learning algorithms to tackle this lack of adaptability and to enable robots to solve complex tasks autonomously. Two types of learning algorithms are particularly suitable for robots to learn controllers autonomously: Deep Reinforcement Learning and Neuro-Evolution. However, both classes of algorithms often cannot solve Hard Exploration Problems, that is problems with a long horizon and a sparse reward signal, unless they are guided in their learning process. One can consider different approaches to tackle those problems. An option is to search for a diversity of behaviors rather than a specific one. The idea is that among this diversity, some behaviors will be able to solve the task. We call these algorithms Diversity Search algorithms. A second option consists in guiding the learning process using demonstrations provided by an expert. This is called Learning from Demonstration. However, searching for diverse behaviors or learning from demonstration can be inefficient in some contexts. Indeed, finding diverse behaviors can be tedious if the environment is complex. On the other hand, learning from demonstration can be very difficult if only one demonstration is available. This thesis attempts to improve the effectiveness of Diversity Search and Learning from Demonstration when applied to Hard Exploration Problems. To do so, we assume that complex robotics behaviors can be decomposed into reaching simpler sub-goals. Based on this sequential bias, we try to improve the sample efficiency of Diversity Search and Learning from Demonstration algorithms by adopting Divide & Conquer strategies, which are well-known for their efficiency when the problem is composable. Throughout the thesis, we propose two main strategies. First, after identifying some limitations of Diversity Search algorithms based on Neuro-Evolution, we propose Novelty Search Skill Chaining. This algorithm combines Diversity Search with Skill- Chaining to efficiently navigate maze environments that are difficult to explore for state-of-the-art Diversity Search. In a second set of contributions, we propose the Divide & Conquer Imitation Learning algorithms. The key intuition behind those methods is to decompose the complex task of learning from a single demonstration into several simpler goal-reaching sub-tasks. DCIL-II, the most advanced variant, can learn walking behaviors for under-actuated humanoid robots with unprecedented efficiency. Beyond underlining the effectiveness of the Divide & Conquer paradigm in Robot Learning, this work also highlights the difficulties that can arise when composing behaviors, even in elementary environments. One will inevitably have to address these difficulties before applying these algorithms directly to real robots. It may be necessary for the success of the next generations of robots, as outlined by Asimov
Bosc, Guillaume. „Anytime discovery of a diverse set of patterns with Monte Carlo tree search“. Thesis, Lyon, 2017. http://www.theses.fr/2017LYSEI074/document.
Der volle Inhalt der QuelleThe discovery of patterns that strongly distinguish one class label from another is still a challenging data-mining task. Subgroup Discovery (SD) is a formal pattern mining framework that enables the construction of intelligible classifiers, and, most importantly, to elicit interesting hypotheses from the data. However, SD still faces two major issues: (i) how to define appropriate quality measures to characterize the interestingness of a pattern; (ii) how to select an accurate heuristic search technique when exhaustive enumeration of the pattern space is unfeasible. The first issue has been tackled by Exceptional Model Mining (EMM) for discovering patterns that cover tuples that locally induce a model substantially different from the model of the whole dataset. The second issue has been studied in SD and EMM mainly with the use of beam-search strategies and genetic algorithms for discovering a pattern set that is non-redundant, diverse and of high quality. In this thesis, we argue that the greedy nature of most such previous approaches produces pattern sets that lack diversity. Consequently, we formally define pattern mining as a game and solve it with Monte Carlo Tree Search (MCTS), a recent technique mainly used for games and planning problems in artificial intelligence. Contrary to traditional sampling methods, MCTS leads to an any-time pattern mining approach without assumptions on either the quality measure or the data. It converges to an exhaustive search if given enough time and memory. The exploration/exploitation trade-off allows the diversity of the result set to be improved considerably compared to existing heuristics. We show that MCTS quickly finds a diverse pattern set of high quality in our application in neurosciences. We also propose and validate a new quality measure especially tuned for imbalanced multi-label data
Roche, Alexis. „Reconnaissance et performance : proposition du concept de reconnaissance activatrice et d'un modèle intégrateur“. Thesis, Lyon 3, 2013. http://www.theses.fr/2013LYO30011/document.
Der volle Inhalt der QuelleRecognition affects every one in a lot of situation. Because it’s semantic complexity, the concept is not easy to clearly define and use it. Miscellaneous branches as : Philosophy, psychology, Sociology, Biology or Anthropology, are wondering by this concept of recognition. This concept is still used more and more by the Management Sciences. This period is marked by development of multiculturalism, the appearance of economic crisis, an increase of impersonal management of the human being and a loss of work sense. So, researchers and practitioners are thinking about the way over to set forth right recognition rules and about the costs created by the defects of recognition at work. Indeed, it becomes a necessity to place Man into the heart of the work and secure a mutual respect between the various actors, hierarchical or not.This research object is emerging in the field of Management Sciences. However, it is the basis of currents events, especially concerning the diversity management and the social responsibility. So, the subject is really at the focal point of moral stakes. Facing the impacts sourced by the depersonalization into the working organizations, more and more people from the bottom to the top of theirs hierarchy are questioning on the social and economic stakes coming from missing recognition and recognition management. This thesis aims at to place in an obvious position the strong links existing between recognition and performance, especially when the organizations want sustainable socioeconomic performances.The first part of the thesis clarify the abstract and methodological bases of these investigations and set out our experimentations fields. The recognition concept is approached under a polysemic and interdisciplinary angle. The justification of the methodology, the exploitation of more than 400 interviews from 12 organizations with the whole employee’s grades and the study of two longitudinal cases testify the robustness of the research work.The second part explain the socially constructed origin of recognition according to the history of each person. It analyzes its perceptive and symbolical aspects. We propose a list of the system of recognition and make an inventory of several transverse factors acting upon the recognition perceptions and their impacts on the feelings of satisfaction and dissatisfaction. At last, we study the influence of three variables : the organization size, the hierarchical level and the business branch, upon the recognition expectations.The third part analyzes two longitudinal cases and establishes links between recognition and performance. We estimate the costs connected to the bad practices in recognition and to the lack of recognition. We categorize two dialectical recognition systems into the organizations and bring results according to these practices. At last, we suggest some possibilities for a recognition enhancement aiming to develop sustainable socioeconomic performances by the elaboration of concept : « activating recognition »
Mavridis, Dimitris Alexandre. „Labor market behavior and well-being“. Paris, EHESS, 2014. http://www.theses.fr/2014EHES0168.
Der volle Inhalt der QuelleMy thesis consists of four distinct chapters which have one underlying theme, which is to study how different local conditions may affect labor supply and other behaviors such as trust, social capital, subjective well-being (SWB) and happiness. The first chapter is tilled "Happy on the Job? Employment and Subjective Well-Being in Indonesia". In it, I look at whether working in the informal sector makes people worse off compared to working formally. The second chapter is titled after the result in it: "When Unemployment Hurls the Return to Work is Faster". It provides an unemployment duration model which combines SWB data to estimate how long people slay unemployed depending on how much they reported being affected when they entered into unemployment. The third chapter. "Ethnic Diversity and Trust in Indonesia" links census and survey data to find whether ethnically diverse districts arc different in terms of social capital and trust than more homogeneous districts. In the final chapter, I look at whether local inequality is correlated to happiness in Indonesia Taken together, the chapters provide a few findings that stand out when one thinks of how local conditions - be it the employment composition by industry, the local inequality level or the ethnic composition, may affect people's happiness, subjective well-being, and their behavior