Dissertations / Theses on the topic 'Réseaux de connaissances en ligne'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Réseaux de connaissances en ligne.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
Gaillard, Emmanuelle. "Gérer et exploiter des connaissances produites par une communauté en ligne : application au raisonnement à partir de cas." Electronic Thesis or Diss., Université de Lorraine, 2016. http://www.theses.fr/2016LORR0092.
Full textThis research work presents two approaches to improve the quality of the results returned by a case-based reasoning system (CBR) exploiting knowledge produced by an e-community. The first approach relies on a new model to manage the trustworthiness of the knowledge produced by the e community. In this model, the trustworthiness is represented through a score which is used to filter untrustworthy knowledge so that the CBR system will not use it anymore. Moreover, the trustworthiness score is also used to rank the CBR results. The second approach addresses the issue of representing the typicality between subclasses and classes in a hierarchy. The typicality is used to change the hierarchical organization used by the CBR system. Both approaches have been evaluated in the framework of eTaaable, a CBR system which adapts cooking recipes using knowledge coming from an e-community. The evaluations show that managing the trustworthiness of the knowledge produced by an e-community improves the quality of the results returned by eTaaable. The evaluations also shows that eTaaable returns also better results when using knowledge reorganized according to typicality
Gaillard, Emmanuelle. "Gérer et exploiter des connaissances produites par une communauté en ligne : application au raisonnement à partir de cas." Thesis, Université de Lorraine, 2016. http://www.theses.fr/2016LORR0092/document.
Full textThis research work presents two approaches to improve the quality of the results returned by a case-based reasoning system (CBR) exploiting knowledge produced by an e-community. The first approach relies on a new model to manage the trustworthiness of the knowledge produced by the e community. In this model, the trustworthiness is represented through a score which is used to filter untrustworthy knowledge so that the CBR system will not use it anymore. Moreover, the trustworthiness score is also used to rank the CBR results. The second approach addresses the issue of representing the typicality between subclasses and classes in a hierarchy. The typicality is used to change the hierarchical organization used by the CBR system. Both approaches have been evaluated in the framework of eTaaable, a CBR system which adapts cooking recipes using knowledge coming from an e-community. The evaluations show that managing the trustworthiness of the knowledge produced by an e-community improves the quality of the results returned by eTaaable. The evaluations also shows that eTaaable returns also better results when using knowledge reorganized according to typicality
Charbey, Raphaël. "Sociabilités en ligne, usages et réseaux." Thesis, Paris, ENST, 2018. http://www.theses.fr/2018ENST0049/document.
Full textWith the digital advent, it is now possible for researchers to collect important amounts of data and online social network platforms are surely part of it. Sociologists, among others, seized those new resources to investigate over interaction modalities between individuals as well as their impact on the structure of sociability. Following this lead, this thesis work aims at analyzing a large number of Facebook accounts, through data analysis and graph theory classical tools, and to bring methodological contributions. Two main factors encourage to study Facebook social activities. On one hand, the importance of time spent on this platform by many Internet users justifies by itself the sociologists interest. On the other, and contrarily to what we observe on other social network websites, ties between individuals are similar to the ones that appear offline. First, the thesis proposes to detangle the multiple meanings that are behind the fact of ”being on Facebook”. The uses of our surveyed are not compacted in fantasized normative practices but vary depending on how they appropriate the different composers of the platform tools. These uses, as we will see it, do not concern all the socioprofessional categories in the same way and they also influence how the respondents interact with their online friends. The manuscript also explores these interactions, as well as the lover role into the relational structure. Second part of the thesis builds a typology of these relational structures. They are said as egocentred, which means that they are taken from the perspective of the respondent. This typology of social networks is based on their graphlet counts, that are the number of times each type of subnetwork appear in them. This approach offers a meso perspective (between micro and macro), that is propitious to underline some new social phenomena. With a high pluri-disciplinary potential, the graphlet methodology is also discussed and explored itself
Charbey, Raphaël. "Sociabilités en ligne, usages et réseaux." Electronic Thesis or Diss., Paris, ENST, 2018. http://www.theses.fr/2018ENST0049.
Full textWith the digital advent, it is now possible for researchers to collect important amounts of data and online social network platforms are surely part of it. Sociologists, among others, seized those new resources to investigate over interaction modalities between individuals as well as their impact on the structure of sociability. Following this lead, this thesis work aims at analyzing a large number of Facebook accounts, through data analysis and graph theory classical tools, and to bring methodological contributions. Two main factors encourage to study Facebook social activities. On one hand, the importance of time spent on this platform by many Internet users justifies by itself the sociologists interest. On the other, and contrarily to what we observe on other social network websites, ties between individuals are similar to the ones that appear offline. First, the thesis proposes to detangle the multiple meanings that are behind the fact of ”being on Facebook”. The uses of our surveyed are not compacted in fantasized normative practices but vary depending on how they appropriate the different composers of the platform tools. These uses, as we will see it, do not concern all the socioprofessional categories in the same way and they also influence how the respondents interact with their online friends. The manuscript also explores these interactions, as well as the lover role into the relational structure. Second part of the thesis builds a typology of these relational structures. They are said as egocentred, which means that they are taken from the perspective of the respondent. This typology of social networks is based on their graphlet counts, that are the number of times each type of subnetwork appear in them. This approach offers a meso perspective (between micro and macro), that is propitious to underline some new social phenomena. With a high pluri-disciplinary potential, the graphlet methodology is also discussed and explored itself
Baytok, Hazal. "Participation in Citizen Science : Motivational and Contextual Factors." Electronic Thesis or Diss., université Paris-Saclay, 2024. http://www.theses.fr/2024UPASI001.
Full textCitizen science is the participation of people who are not scientists in research processes such as data collection and analysis. Citizen science provides various benefits like faster and easier data collection, investigation of environmental challenges from biodiversity to climate change, as well as contributing to astronomy research and leading to collaboration between the scientists and the public.Realising the potential benefits of citizen science depends on understanding the perspectives of participants. In this study, I examine different ways of participation in citizen science and how the motivations of participants, the design of the platforms, and other factors are associated with these. The thesis contributes to our understanding of the key ingredients in designing citizen science programs so as to increase the engagement of the public.In the first part, I carried out a literature survey by bibliometric analysis. This part focuses on challenges, success factors, and motivations in citizen science. The rest of the thesis is composed of one qualitative and another quantitative study by focusing on three citizen science platforms that are actively used in the field of ornithology in two countries, Turkey and France, which are Faune-France from France, Trakuş and eKuşbank (eBird Turkey) from Turkey.In the qualitative part, through semi-structured in-depth interviews, I examine the actors, different ways of participation, motivations, and negative externalities that may arise using the Multi-Sided Platforms (MSPs) and knowledge commons literature.The results of this part helped us identify four roles in the platforms: birdwatcher, bird photographer, scientist, and hunter, interacting with each other and creating externalities.I also found two types of participation: active and passive. Regarding motivations, the findings suggested similarities in the previous studies. However, as different from previous work, I highlighted the need to distinguish motivations for engagement in the platform on the one hand and motivations for the subject matter (birds in our case) on the other.In the second part, by conducting a large-scale survey targeted at the participants of the three platforms and an econometric analysis, I examined how motivations are associated with participation, as well as the negative externalities and values created by the platform. In this part, I draw upon the Self-Determination Theory (SDT), Multi-Sided Platforms (MSPs), and negative externalities concept from the commons literature.The findings in the second part suggest that the two types of motivations identified in the first part (motivation for the subject and motivation for platform engagement) are positively associated with active and passive participation. Also, values offered by the platform and platforms' ways of addressing negative externalities have different impacts on active and passive participation based on the context, such as the participants' perceived importance of competitions positively affecting their active participation in France, whereas not having a significant impact in Turkey. Similarly, participants' perceived importance of the protection of sensitive data by the platform has a negative association with passive participation in France while being positively associated with it in Turkey. These results are important to understand the participants and to better design successful citizen science platforms
Guillet, Vincent. "Contribution à la connaissance et à la caractérisation du canal courant porteur en ligne." Thesis, Orléans, 2010. http://www.theses.fr/2010ORLE2020.
Full textAfter presenting the different methods to measure the power line cables propagation parameters, we justify our choice to measure these parameters up to 100 MHz using an impedance meter. Then, we validate the method of measurements and estimate these parameters on a reference cable (50 Ω cable). This phase has led us to develop a novel method for estimating propagation parameters that can overcome the measure artifacts. Afterwards, we present a comparative study on power line cable responding to the same electrical standards. This study highlights the variability of propagation: one manufacturer to another (using different dielectric), for different types (rigid versus flexible: U1000 R02V / H07 VVF) for different sections (1.5 mm² 2.5 mm²). For an optimal model is therefore essential to have the propagation parameters for the specific cable installation studied. Moreover, the grid should not be changed during installation (near the driver: cable trays, performing loops ...).The final section begins by presenting the different types of noise present on the PLC channel (time-domain and frequency-domain noise). This part allows us to present an original method for estimating the background noise of the channel less sensitive to frequency-jammers. We compare measurements on several simple network topologies with simulation results (using chain matrices). This comparison allows us to validate the method of measurement, the power line cable propagation parameter estimation, and a simple grid model. Finally, this study shows the limits of this model in the case of an actual installation. Indeed, it does not take into account e.g. the “installation parameters” or the phenomena of radiation
Mohamed, Moussa Elmokhtar. "Conversion d’écriture hors-ligne en écriture en-ligne et réseaux de neurones profonds." Electronic Thesis or Diss., Nantes Université, 2024. http://www.theses.fr/2024NANU4001.
Full textThis thesis focuses on the conversion of static images of offline handwriting into temporal signals of online handwriting. Our goal is to extend neural networks beyond the scale of images of isolated letters and as well to generalize to other complex types of content. The thesis explores two distinct neural network-based approaches, the first approach is a fully convolutional multitask UNet-based network, inspired by the method of [ZYT18]. This approach demonstrated good results for skeletonization but suboptimal stroke extrac- tion. Partly due to the inherent temporal mod- eling limitations of CNN architecture. The second approach builds on the pre- vious skeletonization model to extract sub- strokes and proposes a sub-stroke level modeling with Transformers, consisting of a sub- stroke embedding transformer (SET) and a sub-stroke ordering transformer (SORT) to or- der the different sub-strokes as well as pen up predictions. This approach outperformed the state of the art on text lines and mathematical equations databases and addressed several limitations identified in the literature. These advancements have expanded the scope of offline-to-online conversion to include entire text lines and generalize to bidimensional content, such as mathematical equations
Quentin, Isabelle. "Fonctionnements et trajectoires des réseaux en ligne d'enseignants." Phd thesis, École normale supérieure de Cachan - ENS Cachan, 2012. http://tel.archives-ouvertes.fr/tel-00823180.
Full textQuiniou, Solen. "Intégration de connaissances linguistiques pour la reconnaissance de textes manuscrits en-ligne." Phd thesis, Rennes, INSA, 2007. ftp://ftp.irisa.fr/techreports/theses/2007/quiniou.pdf.
Full textThe aim of this thesis is to build a sentence regognition system based on an existing word regognition system. Two research axes are considered: the sentence segmentation int words as well as the integration of linguistic knowledge to take into account the context of the sentences. We studied several types of statistic language models by comparing their respective impact on the recognition system performances. We also tried to find the best strategy to introduce them efficiently into the whole recognition system. One of the originality of this study is the integration of a representation of the different sentence hypotheses in the form of a confusion network; which is then used to detect and correct the remaining regognition errors. Using the aforementioned techniques allowed us to considerably reduce the number of recognition errors among the words of the sentences
Quiniou, Solen. "Intégration de connaissances linguistiques pour la reconnaissance de textes manuscrits en-ligne." Phd thesis, INSA de Rennes, 2007. http://tel.archives-ouvertes.fr/tel-00580623.
Full textStella, Elie. "L’adaptation du droit pénal aux réseaux sociaux en ligne." Thesis, Université de Lorraine, 2019. http://www.theses.fr/2019LORR0344.
Full textOnline social networks demonstrate the transcription, as well as the intensification, of human relationships on a digital level. More generally, the apparition and widespread use of these sites reveal a profound evolution of social relationships that began in the mid-2000s. Consequently, criminal law, as a “mirror of civilisation” has necessarily been impacted to the extent of warranting its adaptation.These websites undeniably constitute a new legal arena within which delinquent online behaviour is present. For the most part, online social networks are merely a new medium for infringements, to which pre-existing criminal offences are perfectly designed to apply, should they arise. However, new forms of infringements have emerged from these places of exchange, highlighting the structural shortcomings within criminal law, that manifest as the inability of pre-existing criminal offences to cover these new forms of infringements. Criminal law has therefore adapted through the creation of new criminal offences, demonstrating the profound evolution of the protection of privacy, identity and more generally, private life, under criminal law.Social networks also raise criminal law issues with regard to the suppression of delinquent online behaviour that can be found on them. In this case, the regimes of criminal responsibility applicable to different social network players, users and operators, demonstrate a certain unsuitability which manifests itself as the ineffectiveness of criminal law on social networks. The solution therefore consists of developing, or rather diversifying the response to emerging offences and providing a framework for the regulation of content in collaboration with the administrative authorities. A new regime of responsibility thus emerges, applicable to the main digital sharing platforms, that progressively promotes a principle of compliance within them. Ultimately, criminal law adapts to online social networks as much as social networks adapt to criminal law
Ibrahim, Sharawy. "L' architecture d'un système de traitement d'image ligne par ligne." Compiègne, 1986. http://www.theses.fr/1986COMPI234.
Full textThovex, Christophe. "Réseaux de compétences : de l'analyse des réseaux sociaux à l'analyse prédictive de connaissances." Phd thesis, Nantes, 2012. https://archive.bu.univ-nantes.fr/pollux/show/show?id=9655d57c-574a-4377-8aa1-cc682eecb122.
Full textIn 1977, Freeman formalised generic measures of Social Networks Analysis (SNA). Then, the Web “2. 0” social networks have become global networks (e. G. , FaceBook, MSN). This thesis defines a semantic model, non probabilist and predictive, for the decisional analysis of professional and institutional social networks. The presented multidisciplinary model, in parallel to the Galam sociophysics, integrates some semantic methods of natural language processing and knowledge engineering, some measures of statistic sociology and some electrodynamic laws, applied to the economic performance and social climate optimisation. It has been developped and experimented in line with the Socioprise project, funded by the French State Secretariat for the prospective and development of the digital economy
Thovex, Christophe. "Réseaux de Compétences : de l'Analyse des Réseaux Sociaux à l'Analyse Prédictive de Connaissances." Phd thesis, Université de Nantes, 2012. http://tel.archives-ouvertes.fr/tel-00697798.
Full textLi, Jinpeng. "Extraction de connaissances symboliques et relationnelles appliquée aux tracés manuscrits structurés en-ligne." Phd thesis, Nantes, 2012. http://tel.archives-ouvertes.fr/tel-00785984.
Full textCarbonnel, Sabine. "Intégration et modélisation de connaissances linguistiques pour la reconnaissance d'écriture manuscrite en-ligne." Rennes, INSA, 2005. http://www.theses.fr/2005ISAR0022.
Full textHandwriting recognition is a difficult problem which cannot be reduced to graphic shapes recognition: it is important to integrate linguistic knowledge to guide the recognition. The objectives of our work are to integrate lexical knowledge to improve a recognition system of on-line handwritten words, taking into account constraints of computing time and memory requirement with the intention of integrate the system on devices with limited capacities. We propose a lexical processing based on a language model of characters n-grams, a modeling to reduce the research space in a lexicon as well as an automatic modeling of an edit distance specific to handwriting. These modelings improve the recognition system on which our work is based, limit the duration of the lexical processing and moreover are easily adaptable to the system evolutions and the context of use
Carbonnel, Sabine Lorette Guy. "Intégration et modélisation de connaissances linguistiques pour la reconnaissance d'écriture manuscrite en-ligne." (S.l.) : (s.n.), 2005. ftp://ftp.irisa.fr/techreports/theses/2005/carbonnel.pdf.
Full textHugon, Stéphane. "Circumnavigations : la construction sociale de l'identité en ligne." Paris 5, 2007. http://www.theses.fr/2007PA05H011.
Full textStarting from an investigation of ground near users of the Internet, the thesis proposes to regard the success of the communications on line(chat, blog) as an evidence of a deep change of our society, in particular affecting social construction of the identity and nature of the social bond. The thesis poses the assumption that the success of these social forms is linked to the presence of imaginary which is former for him, imaginary drift and navigation, present in testimonys of the users met, and in a whole side of the European culture. Moreover, the experiment of the Net surfer is inseparable from one report/ratio to the machine. If the social history of technics were the place of a critical thought a long time on the boarding of the individual, it seems that the social re-appropriations of the computers give the sign of a form of réenchantement by the creation of social bond and of a culture resolutely directed towards the ludic one and the oneiric one
ZEKRI, Dorsaf. "Agrégation et extraction des connaissances dans les réseaux inter-véhicules." Phd thesis, Institut National des Télécommunications, 2013. http://tel.archives-ouvertes.fr/tel-00826971.
Full textZekri, Dorsaf. "Agrégation et extraction des connaissances dans les réseaux inter-véhicules." Thesis, Evry, Institut national des télécommunications, 2013. http://www.theses.fr/2013TELE0001/document.
Full textThe works in this thesis focus on data management in inter-vehicular networks (VANETs). These networks consist of a set of moving objects that communicate with wireless networks IEEE 802.11, Bluetooth, or Ultra Wide Band (UWB). With such communication mechanisms, a vehicle may receive information from its close neighbors or other more remote, thanks to multi-jump techniques that operate in this case intermediate objects as relays. A lot of information can be exchanged in the context of « VANETs », especially to alert drivers when an event occurs (accident, emergency braking, vehicle leaving a parking place and want to inform others, etc.). In their move vehicles are then « contaminated » by the information provided by others. In this work, we use the data substantially different from the existing work. These are, in fact, use the data exchanged to produce alerts drivers. Once these data are used, they become obsolete and are destroyed. In this work, we seek to generate dynamically from data collected by vehicles in their path, a summary (or aggregate) which provides information to drivers, including when no communicating vehicle is nearby. To do this, we first propose a spatio-temporal aggregation structure enabling a vehicle to summarize all the observed events. Next, we define a protocol for exchanging summaries between vehicles without the mediation of an infrastructure, allowing a vehicle to improve its local knowledge base by exchange with its neighbors. Finally, we define our operating strategies of the summary to assist the driver in making decision. We validated all of our proposals using the «VESPA» simulator by extending it to take into account the concept of summaries. Simulation results show that our approach can effectively help drivers make good decisions without the need to use a centralized infrastructure
Perron, Laurence. "La réutilisation des connaissances en supervision de réseaux de télécommunications." Paris 8, 1996. http://www.theses.fr/1996PA081160.
Full textThis doctoral thesis is based on a combined psychological and ergonomic approach. It concerns research on analogical reasoning and on episodic memory retrieval. More precisely this research focused on knowledge reuse in telephone traffic monitoring in order to better design support tools. Case-based reasoning (cbr) in artificial intelligence has been studied in this thesis to see if it could possibly be used as a support system. Task analyses, activity analyses, behavior trace analyses, incident traces and an experiment using an incident categorisation task were conducted. These methodological approaches showed that two main factors were involved in traffic monitoring from the diagnosis of the incidents to their categorisation. These are the multiplicity of the task goals, and the heterogeneity of the operators' episodic knowledge. As postulated by the " episodic memory " theory on specific encoding, the encoding context determines knowledge retrieval and more specifically in work situations where the context is linked to the task and its goals but also to the work team and to the knowledge shared by the operators. The similarity between incidents has been shown to be " situated " in the context of a goal oriented activity and for each specific operator. It then appeared impossible to use a cbr support tool that would not take into account the operators' variability. The special relations linking the task and the operator that intervene in the process of describing and retrieving the incidents, lead to the study of a formal description. In fact these formal description should be significant, functional to the operators
Reyes, Salgado Gerardo. "Connaissances de haut niveau dans les systèmes hybrides neuro-symboliques." Grenoble INPG, 2001. http://www.theses.fr/2001INPG0047.
Full textNiveau, Alexandre. "Compilation de connaissances pour la décision en ligne : application à la conduite de systèmes autonomes." Phd thesis, Université Paul Sabatier - Toulouse III, 2012. http://tel.archives-ouvertes.fr/tel-00758266.
Full textChen, Ziqiang. "Représentation et gestion de connaissances temporelles et incertaines." Paris 11, 1993. http://www.theses.fr/1993PA112099.
Full textRemm, Jean-François. "Extraction de connaissances par réseaux neuronaux : application au domaine du radar." Nancy 1, 1996. http://www.theses.fr/1996NAN10366.
Full textNedjari, Tayeb. "Réseaux de neurones artificiels et connaissances symboliques : insertion, raffinement et extraction." Paris 13, 1998. http://www.theses.fr/1998PA132024.
Full textGuiochon, Samuel. "Modélisation et contrôle en ligne d'une polymérisation : l'apport des réseaux de neurones." Bordeaux 1, 1996. http://www.theses.fr/1996BOR10637.
Full textDos, Santos Prado Gilberto. "Expériences artistiques d'échanges d'images dans les réseaux télématiques : La ligne lune imaginaire." Paris 1, 1993. http://www.theses.fr/1993PA010735.
Full textThis thesis discusses and explores some of the new communications technology (fax and computer) in the artistic networks. It's emphasizes the questions of the possible cultural exchanges : the interactions and cross of different expressions and sensibilities by the persons geographically and culturally distant, connects in the cyberspace. Four artistic telematic projects were developed : connect (fax) ; telescanfax (scanner television faxmodem) ; chain-reaction (modem) ; moone : la face cachee de la lune (i. S. D. N. ). Finally, a general survey of the state of the art in telemartic artistic networks then allows for a panorama of the actual dynamic stage
Deschamps, David. "Régulation d'une ligne d'étamage électrolytique." Lille 1, 1998. https://pepite-depot.univ-lille.fr/LIBRE/Th_Num/1998/50376-1998-460.pdf.
Full textRavot, Nicolas. "Analyse et diagnostic de réseaux filaires complexes par réflectométrie." Paris 11, 2007. http://www.theses.fr/2007PA112142.
Full textThe evolution of technologies and the communication modules involve a growing complexity of the embedded systems. These systems are smarter and use more and more sensors and others components. The increase of embedded systems implies the increase of wired network that is the physical support for the data transfer and devices supply. A wired network is composed of several kinds of cables and connectors. These systems can operate in different environments and conditions that can induce failures, because of a defective cable. Nowadays, several problems begin to appear in the wired networks. A tool for diagnosing a wired network would be greatly helpful for maintenance and monitoring. The proposed solution in this thesis allows analysing and diagnosing the health of a wired network without ambiguities. We have developed a new method, called distributed reflectometry by M-sequences, which is more effective and more reliable for analysing wired networks and which considers different aspects such as integration, precision and performance. Indeed, the diagnosis function distribution in a wired network allows apprehending a complete network and guarantees a simple reflectograms analysis without incorrect interpretations. This original method, purely numerical, is an adequate solution for embedded applications
Bendou, Mohamed. "Extraction de connaissances à partir des données à l'aide des réseaux bayésiens." Paris 11, 2003. http://www.theses.fr/2003PA112053.
Full textThe main objective of this thesis basically focuses on developing a new kind of learning algorithms of Bayésiens networks, more accurate, efficient and robust in presence of the noise and, therefore, adapted to KDD tasks. Since most of local optima in the space of networks bayésiens structures are caused directly by the existence of equivalence classes (sets of structures encoding the same conditional independence relations, represented by the partially oriented graphs), we concentrated important part of our researches on the development of a new family of learning algorithms: EQ. These algorithms directly explore the space of equivalence classes. We also developed theoretical and algorithmic tools for the analysis and the treatment of partially oriented graphs. We could demonstrate that a meaningful precision gains brought by this kind of approach can be obtained in a comparable time than the classical approaches. We, thus, contributed to the present interest renewal for the learning of equivalence classes of bayesian networks (considered for a long time as too complex by the scientific community). Finally, another aspect of our research has been dedicated to the analysis of noise effects in data on the learning of the Bayesians networks. We analyzed and explained the increase of the complexity of learned Bayesian networks learned from noisy data and shown that, unlike classical over-fitting which affects other classes of learning methods, this phenomenon is theoretically justified by the alteration of the conditional independence relations between the variables and is beneficial for the predictive power of the learned models
Chauvenet, Cédric. "Protocoles de support IPv6 pour réseaux de capteurs sur courant porteur en ligne." Thesis, Grenoble, 2013. http://www.theses.fr/2013GRENM067/document.
Full textThis thesis demonstrate the relevance of Powerline Communication (PLC) usage for sensor networks applications. We focus in particular on the low power and low data rate PLC technol- ogy "Watt Pulse Communication" (WPC) developed by the Watteco company and justify its usage for sensor network applications. We situate the WPC technology in the PLC landscape and define compatible protocols. We then describe the WPC module and the PLC media im- plementation in the COOJA network simulator. This allows us to propose a network solution over this technology, leveraging on the adaptation of the 802.15.4 standard over the WPC tech- nology. We then demonstrate the benefit of media convergence at the network layer level, with the use of the IPv6 standard that we adapted over our PLC solution thanks to the 6LoWPAN protocol. We justify the usage of standards protocols over our PLC solution and show that a routing solutions must be developed over WPC. We show through experiments that our PLC solution match low power and lossy network (LLNs) criterions for which the RPL standard pro- tocol has been designed. We justify the usage of this routing protocol over our PLC solution, and validate its implementation through 2 experiments conducted in tertiary types buildings. Respectively composed of 7 and 26 PLC nodes, results show that the routing topology created by RPL enable the coverage an entire floor of a tertiary building with a tree based topology and 3 hops maximum path length. We also show that the WPC technology exhibits a high connectivity between nodes and that the link quality is highly dynamic. Though, we observed that the routing topology was able to handle these variations. We point out the limitations of our PLC solution, which presents high delays and low throughput, creating high constraints on applications. Our sensor network solution over PLC relies on the IP standard, enabling packets exchanges with other technologies using the same protocol. In particular, we study the possi- bility to create heterogeneous networks mixing the WPC technology with 802.15.4 radio. We show that our protocol stack used over PLC enable to create this type of network, in order to benefit from the best of these 2 worlds. We purpose an architecture of a hybrid Radio / PLC node enabling to transfer packets between these 2 media. Then, we show that the combined usage of these 2 media increase the number of available paths and facilitate the routing, while diminishing the number of hops and possible unreachability of nodes. We then demonstrate that the addition of PLC and Radio/PLC nodes in a RF based battery powered sensor network enable to relieve their routing charge in order to expand their lifetime. We then continue the energy study with a power consumption optimization of a wireless sensor network platform from the hardware and software standpoint. We first determine the operating frequency, the wake up frequency and the mode of operation of the micro controller offering the lowest power consump- tion. We then conduct an energy study of 4 different radio transceivers using the 2.4 GHz and 868 MHz frequency band, in order to determine the most efficient architecture. We determine the protocols parameters and the software optimization to reach the lower power consumption of this architecture. Finally, we realize the energy study of several probes than can be embedded on the node, according to their nature and functioning mode. Our final architecture exhibits a total power consumption that is lower than 17 μW, with an applicative reporting each 10 minutes and the maintenance of the reachability with the network. We also mention in annex parts our implication in standards developments organizations such as the IETF a the IPSO alliance, that allow us to validate the implementation of our solution through interoperability events
Osman, Ousama. "Méthodes de diagnostic en ligne, embarqué et distribué dans les réseaux filaires complexes." Thesis, Université Clermont Auvergne (2017-2020), 2020. http://www.theses.fr/2020CLFAC038.
Full textThe research conducted in this thesis focuses on the diagnosis of complex wired networks using distributed reflectometry. It aims to develop new distributed diagnostic techniques for complex networks that allow data fusion as well as communication between reflectometers to detect, locate and characterize electrical faults (soft and hard faults). This collaboration between reflectometers solves the problem of fault location ambiguity and improves the quality of diagnosis. The first contribution is the development of a graph theory-based method for combining data between distributed reflectometers, thus facilitating the location of the fault. Then, the amplitude of the reflected signal is used to identify the type of fault and estimate its impedance. The latter is based on the regeneration of the signal by compensating for the degradation suffered by the diagnosis signal during its propagation through the network. The second contribution enables data fusion between distributed reflectometers in complex networks affected by multiple faults. To achieve this objective, two methods have been proposed and developed: the first is based on genetic algorithms (GA) and the second is based on neural networks (RN). These tools combined with distributed reflectometryallow automatic detection, location, and characterization of several faults in different types and topologies of wired networks. The third contribution proposes the use of information-carrying diagnosis signal to integrate communication between distributed reflectometers. It properly uses the phases of the MCTDR multi-carrier signal to transmit data. This communication ensures the exchange of useful information (such as fault location and amplitude) between reflectometers on the state of the cables, thus enabling data fusion and unambiguous fault location. Interference problems between the reflectometers are also addressed when they simultaneously inject their test signals into the network. These studies illustrate the efficiency and applicability of the proposed methods. They also demonstrate their potential to improve the performance of the current wired diagnosis systems to meet the need and the problem of detecting and locating faults that manufacturers and users face today in electrical systems to improve their operational safety
Raya, Katia. "Réseaux sociaux et communautés en ligne dans le paysage universitaire libanais (2018-20)." Thesis, Sorbonne université, 2020. http://www.theses.fr/2020SORUL107.
Full textTo face the challenges and strong competition of today, higher education has turned to the strategy of communication on social networks in order to retain their audience, improve their reputation and strengthen relations with the community through higher levels of engagement. The aim of this thesis is to understand this engagement of the university community on social networks. The research is initially interested in the study of key concepts related to its objective, namely, engagement, community and social media. Quantitative and qualitative empirical studies will be implemented using questionnaire and data mining methods. Statistical results, content analysis and community detection helped to understand the role of content strategy and the impact of community profile on engagement levels on posts created by major higher education institutions in Lebanon
Reiffers-Masson, Alexandre. "Compétition sur la visibilité et la popularité dans les réseaux sociaux en ligne." Thesis, Avignon, 2016. http://www.theses.fr/2016AVIG0210/document.
Full textThis Ph.D. is dedicated to the application of the game theory for the understanding of users behaviour in Online Social Networks. The three main questions of this Ph.D. are: " How to maximize contents popularity ? "; " How to model the distribution of messages across sources and topics in OSNs ? "; " How to minimize gossip propagation and how to maximize contents diversity? ". After a survey concerning the research made about the previous problematics in chapter 1, we propose to study a competition over visibility in chapter 2. In chapter 3, we model and provide insight concerning the posting behaviour of publishers in OSNs by using the stochastic approximation framework. In chapter 4, it is a popularity competition which is described by using a differential game formulation. The chapter 5 is dedicated to the formulation of two convex optimization problems in the context of Online Social Networks. Finally conclusions and perspectives are given in chapter 6
Zwecker, Stella. "Représentation et spécification d'architectures d'interconnexion de réseaux hétérogènes vers la définition d'une base de connaissances." Toulouse 3, 1993. http://www.theses.fr/1993TOU30052.
Full textBréard, Patrick. "Réseaux neuromimétiques et gestion des connaissances : Peut-on revendiquer une pertinence des techniques neuromimétiques pour soutenir la gestion des connaissances des organisations ?" Paris, CNAM, 2001. http://www.theses.fr/2001CNAM0377.
Full textThe purpose of this research is to explore the functionnal and organizational relevance of neuromimetic techniques to support knowledge management technologies. The research is exploratory and inductive, based on case studies and qualitative analysis. We observe that endogenous and exogenous environmental factors are driving corporations to rely on knowledge management to increase organizational efficiency. In that aim, we demonstrate the validity to use advanced technologies for knowledge management, and we propose neuromimetic techniques. We show the functional and technical relevance of neuromimetism to answer to the identified needs. Through field studies, we demonstrate that organizations are lowering the functional scope of neuromimetic solutions for knowledge management. This can be due to competing solutions within a firm, and to competing managers. This can come from the will to preserve the existing structure, and the formal positioning of managers. At last, the lack of a dedicated knowledge management program can reduce the benefits from such technologies. We conclude that these technologies are enhancing the cognitive emergence within organizations but sizing its full benefits requires the simultaneous implementation of structural forces. Knowledge management programs confirm their relevance for organization, but further transfer their center of gravity to management
Madani, Nacéra. "Etude de l'héritage des propriétés dans les réseaux sémantiques : Notion de réseau d'héritage légal." Paris 13, 1994. http://www.theses.fr/1994PA132016.
Full textAuillans, Pascal. "Modélisation de réseaux sémantiques par des hypergraphes et applications." Bordeaux 1, 2005. http://www.theses.fr/2005BOR12966.
Full textThe goal of the Web evolutions planned by the W3C is to enable the improvement of web services quality. To this end, W3C has added to the Web architecture a knowledge management system named Semantic Web, which implements a theoretical model relying on descriptive logic. This thesis, of which researches are more specifically applied to another knowledge representation system named Topic Maps, aims to rovide an alternative to the use of descriptive logic. We will show how graph theory can be used to structure the knowledge, hence benefit to the field of knowledge representation. This thesis initialy stands within the european project KePT, which aimed to implement a visualization interface for knowledge, structured according to the norm ISO 13250 Topic Maps, in Mondeca's ITM application. Research on graph clustering made for this project raised the need of both a better understanding of the topic maps structure, and tools that enable implementation of efficient processing. Therefore, we propose a formal model relying on graph theory that enables to express structural properties, beyond the expressive power of first order logic. Our model is not only suited for theoretical studies, but also for the adaptation of fast graph theory algorithms to knowledge processing. These processing were previously hardly implementable in industrial applications
Abdallah, Amani. "Réseaux d'eau intelligents : surveillance de la qualité de l'eau par des capteurs en ligne." Thesis, Lille 1, 2015. http://www.theses.fr/2015LIL10150/document.
Full textThe objective of this thesis is to evaluate the performance of systems proposed for real-time monitoring of water quality in the drinking water network. It was conducted within the European project SmartWater4Europe and SunRise project, which aims at the construction of a demonstrator of the smart city on the campus of the“Cité Scientifique”. The work consists of 4parts:The first part presents a literature review of the work conducted on the real-time monitoring of water quality. It shows the parameters used to monitor the water quality and the technologies available to monitor these parameters.The second part presents the construction of a Lab pilot for analyzing the performance of the water quality control systems. After a description of the systems used in this thesis(EventLab, s :: can and Intellisonde), we present the procedure followed for the realization of contaminant.The third part is devoted to the study of the performance of chlorine monitoring for detection of microbial contaminants. The results show that monitoring of chlorine constitutes an effective tool for monitoring the microbiological quality of drinking water.The fourth part presents the responses of EventLab and s::can to the injection of contaminants. Tests show a high reliability of EventLab and s::can to detect chemical contaminants. Regarding biological contaminants, s::can shows an ability to detect these contaminants for bacterial concentrations exceeding 106UFC/ml.The final part presents the water network of Cité Scientifique. The results of the water quality control are presented and analyzed. It also gives the location of the water quality control systems that will be installed on the water network
Joly, Cathie-Rosalie. "Le paiement sur les réseaux : comment créer la confiance dans le paiement en ligne ?" Montpellier 1, 2004. http://www.theses.fr/2004MON10018.
Full textEhounou, Joseph. "Algorithmes de graphes pour la découverte de la topologie d'un réseau énergétique par la connaissance de ses flots." Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLV056/document.
Full textIn energy network, the knowledge of equipments, their locations and their functions are theimportant information for the distributor service operator. In fact, each operator has a networkplan often named synoptic schema. That schema shows the interconnexion between equipments inthe network. From this schema, some management decisions have taken for ensuring an optimalperformance of a network.Sometimes, a synoptic schema has some mistakes because the maintenance operations, such aschanged the connexion between equipments or replaced equipments, have not been updated orhave been written with errors. And these mistakes increase exploitation cost in the energy network.We consider an electric network of a datacenter. This network consists of physical topologymodelised by a DAG without circuit and measurements are on the edges of a DAG. The mainpoint of the network is that measurements are some mistakes and the topology is unknown i.ewe know edges but the nodes of edges are unknown. When measurements are correct then thecorrelations between pairwise edges provide the adjacency matrix of the linegraph of undirectedgraph of the DAG. A linegraph is a graph in which each node and the neighbor are partitionnedby one or deux cliques. However, with the mistakes in measurements, the obtained graph is nota linegraph because it contains more or less edges. If the obtained graph is a linegraph then it isa linegraph of the other DAG. Our problem is to discovery the topology of the DAG with somemistakes in measurements.We start by the state of art in the measurement correlations in order to choose the good methodfor our problem. Then, we propose two algorithms to resolve our problem. The first algorithmis the cover algorithm and it returns the set of cliques in the graph. The second algorithm is acorrection algorithm which adds or deletes edges in the graph for getting a nearest linegraph ofthe DAG. In the last, we evaluate the performances of the algorithms by checking the number ofedges corrected and the ability to return a nearest linegraph of the DAG
La, Chi Anh. "Réplication de contenu dans les réseaux sans fil mobiles." Paris, Télécom ParisTech, 2010. http://pastel.archives-ouvertes.fr/pastel-00545009.
Full textThe growth of mobile devices and network-based services nowadays has raised a timely question on how to efficiently distribute the data items to mobile users. Network applications need data as an input to process and provide information to users. Consequently, data traffic exerted by mobile devices fetching content is a drainage of mobile operators’ network resources. Mobile users are now coping with the congestion at network gateways and due to the unpredictability of human mobility, mobile service providers cannot sufficiently provision infrastructures for their customers. Content replication in this context has been proved as a good solution to enhance network performance and scalability. In this thesis, we tackle the issues of content replication in heterogeneous mobile networks. Such scheme requires us to solve two basic questions: where and how many replicas should be placed in the system. We study the solution through the lenses of facility location theory and design a distributed mechanism that reduces content access latency and avoids congestion at mobile gateways. Additionally, we consider the resource constraints of mobile devices and introduce a P2P cache-and-forward mechanism for load balancing purpose. We evaluate our mechanisms against realistic human mobility models. Finally, to address rational users who may behave selfishly in replicating content, we derive a cost model and study content replication scheme using tools akin to game theory. Based on the theoretical findings, our future work is to develop the strategies to be implemented in a practical network setting
Ouici, Houria. "Propositions pour une représentation schématisée de connaissances encyclopédiques." Lyon 3, 2002. http://www.theses.fr/2002LYO33012.
Full textDjioua, Brahim. "Modélisation informatique d'une base de connaissances lexicales (DISSC) : réseaux polysémiques et schémas sémantico-cognitifs." Paris 4, 2000. http://www.theses.fr/2000PA040180.
Full textNocera, Pascal. "Utilisation conjointe de réseaux neuronaux et de connaissances explicites pour le décodage acoustico-phonétique." Avignon, 1992. http://www.theses.fr/1992AVIG0102.
Full textZimmermann, Antoine. "Sémantique des réseaux de connaissances : gestion de l'hétérogénéité fondée sur le principe de médiation." Phd thesis, Grenoble 1, 2008. http://www.theses.fr/2008GRE10247.
Full textThe goal is to model the semantics of heterogeneous, matched, networked knowledge. It is assumed that these network are represented as a set of ontologies connected by ontology alignments. In a context like the Web or some peer-to-peer networks, various ontologies are accessible but strongly heterogeneous in terms of expressivity and domain modelling. Moreover, inference systems attached to the ontologies can be independent from each others. I propose a generic semantics for these networks, tolerant to heterogeneity and allowing the exploitation of existing systems without distriburbing them. This semantics also guarantees the mediation principle, and allows reusability of alignments and ontologies. I propose four applications: modular ontologies; expressive alignment language, distinct from the ontology language; alignment composition operators; distributed reasoning procedure
Zimmermann, Antoine. "Sémantique des réseaux de connaissances : gestion de l'hétérogénéité fondée sur le principe de médiation." Phd thesis, Université Joseph Fourier (Grenoble), 2008. http://tel.archives-ouvertes.fr/tel-00341525.
Full textJouve, Christine. "Représentation des connaissances pour les problèmes de conception. Application à un système à base de connaissances pour la conception de réseaux informatiques : NEST." Phd thesis, Ecole Nationale Supérieure des Mines de Saint-Etienne, 1992. http://tel.archives-ouvertes.fr/tel-00832243.
Full textJeunesse, Christophe. "Collaboration et interculturalité dans la formation en ligne. Contribution à l'écologie de l'apprenance." Thesis, Paris 10, 2009. http://www.theses.fr/2009PA100161/document.
Full textThe research concerns the study of specificities connected to the online collaborative learning in a multicultural context. It is situated at the intersection of the reflections carried out on the conceptual fields dealing with the motivation, with the culture, with the gender and with the distance training mediatized by the educational technologies. The context of this study lies in and online university training gathering 249 European and African students, all French-speaking people, in an adult continuing training and working within remote collaborative learning plan. My reflection was driven by the questioning about the way the students lived the online collaboration in multicultural context, in particular on the difficulties shown by the Africans while at the same time they seemed to present a more positive attitude than their western peers towards this method of training. Several successive investigations (preliminary, quantitative and qualitative among representative samples of the students) make it possible to bring a certain number of answers to the question of research as well as additional details. The culture, in particular the sociotechnical environment of the learners, provides an additional variable well to be taken into account with regard to the gender necessary to decode attitudes and behavior of learners who are involved in a online collaborative training. A reflection around the dimensions of the “learnance” (learning readiness) and the transactional distance also allows to understand better the relations between the actors of the training and the necessary adaptations of the training design in such a context