Dissertations / Theses on the topic 'Localisation'
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Huber, Birgit. "Realisability and localisation." [S.l.] : [s.n.], 2007. http://ubdata.uni-paderborn.de/ediss/17/2007/huber.
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Wimberger, Sandro Marcel. "Chaos and Localisation." Diss., lmu, 2004. http://nbn-resolving.de/urn:nbn:de:bvb:19-16877.
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Gunatilaka, Ajith Ristic Branko Gailis Ralph. "Radiological source localisation." Fishermans Bend,Victoria : Defence Science and Technology Organisation, 2007. http://hdl.handle.net/1947/8682.
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Makkerh, Joe Paul Singh. "Nuclear localisation signals." Thesis, University of Cambridge, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.363121.
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Palis, Elisabeth. "Localisation des insulinomes." Caen, 1990. http://www.theses.fr/1990CAEN3032.
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Beamond, Eleanor. "Quantum and classical localisation." Thesis, University of Oxford, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.249185.
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Alonso, i. Fernández Jaume. "Equivariant Cohomology and Localisation." Thesis, Uppsala universitet, Teoretisk fysik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-251286.
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Equivariant localisation is based on exploiting certain symmetries of some systems, generally represented by a non-free action of a Lie group on a manifold, to reduce the dimensionality of integral calculations that commonly appear in theoretical physics. In this work we present Cartan's model of equivariant cohomology in different scenarios, such as differential manifolds, symplectic manifolds or vector bundles and we reproduce the main corresponding localisation results.
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Mahon, Piers Seaburne Macmahon. "Localisation of organelle proteins." Thesis, University of Cambridge, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.621831.
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Luo, Kai. "MIMO radar : target localisation." Thesis, Imperial College London, 2013. http://hdl.handle.net/10044/1/11148.
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The research presented in this thesis is concerned with multi-target localisation in MIMO radar. In particular, the aim is to develop novel algorithms which can improve the performance of target localisation. Firstly, a general spatiotemporal received signal model for MIMO radar is formulated. When the targets' relative delays are negligible, the general model turns into the spatial only signal model in which, in order to enjoy the enhanced parameter identifiability brought by the waveform diversity, a combined approach based on the virtual array structure is proposed for the multiple targets' directions and path gains estimation. The virtual array structure enables the proposed approach to identify more targets with accurate estimation. Besides, inspired by STAR manifold in communications, a novel spatiotemporal signal model for MIMO radar is proposed, which enables the existing multi-target localisation methods designed for the spatial only model working for the spatiotemporal one. Secondly, the multi-target localisation of MIMO radar operating in an envi- ronment with closely located targets is concerned. In such a scenario, the mu- tual interferences among targets severely degrade the performance of the current multi-target parameter estimators. Thus, an optimisation which takes account of the suppression of the mutual interferences for multi-target parameter estimation is formulated and the solutions to it are derived. Thirdly, based on these solu- tions, two novel multi-target parameter estimators are presented. By suppressing the interferences in the estimation, both the proposed methods outperform the existing ones. Finally, for the purpose of exploiting the high directional gain provided by the Tx beamforming in the multi-target localisation of MIMO radar, a joint Tx and Rx multi-target localisation approach is proposed. The cooperation between the Tx beamforming and target localisation enables the proposed approach to achieve better performance for the localisation of multiple targets.
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Tap, Jean-Brice. "La localisation des sociétés." Thesis, Aix-Marseille, 2015. http://www.theses.fr/2015AIXM1035.
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Le XXIe siècle s’est traduit pour les opérateurs économiques par un fort mouvement d’internationalisation qui les a aspirés dans une compétition sans frontières et les a conduit à s’implanter sur le globe au gré de leurs intérêts. Dans ce cadre, quelle attitude le droit adopte-t-il face à la problématique de la localisation des sociétés ? La localisation des sociétés est traditionnellement appréhendée comme une question de droit. En somme, le droit fixe les règles permettant d’inscrire les sociétés dans l’espace. Or, le droit parait abandonner une large place à la volonté, à telle enseigne que l’on puisse considérer que la localisation des sociétés s’affirme ainsi comme un élément disponible soumis à l’influence de la volonté. Face à cela, le droit s’intéresse aux décisions sociales qui affecteront la localisation des sociétés. Les règles qui gouvernent l’adoption des décisions affectant la localisation traduisent fidèlement les enjeux de pouvoir au sein des sociétés. La localisation des sociétés est aujourd’hui, pour le droit, la source d’un défi majeur en ce sens qu’elle est le terrain d’objectifs poursuivis par l’ordre juridique. Il n’hésite donc pas à remettre en cause des localisations choisies ou encore à paralyser certains effets attendus d'une localisation par ailleurs maintenue. Le droit s’autorise ainsi non seulement à tracer une frontière entre le licite et l’illicite mais encore à sanctionner les choix qui, bien que licites, auraient des conséquences inacceptables pour l’ordre juridique. La quête d’un équilibre entre la place de la volonté et le respect de l’impérativité irrigue alors l’action du droit sur la localisation des sociétésThe 21st century has seen economic actors taken into a great movement of internationalization drawing them into a border-free competition that led firms to relocate all over the world according to their own interest. Nowadays, every company, and not only multinational corporations, has to consider the opportunity of spreading abroad. Against this background, how does the law cover the issue of companies’ location?The location of companies has traditionally been considered as an issue of law, with a view to mark out the uncertain. The law lays down the rules to situate companies within space, but gives in to free will when it comes to the actual decisions. One could therefore state that private actors enjoy freedom in locating companies, so much so that the strategy of location could be considered as a mere possibility left to free will. Nevertheless, the law still has a say in the social decisions that affect the location of companies.The location of companies has become a major concern within the law today, as it is a ground for legal practitioners to actively achieve changes. Thus, the law does not hesitate to question a location or to paralyse some of its effects. Even though the law remains quite liberal concerning the location of companies, it does exert a form of control over such decisions. This control is twofold: not only does it draw the line between lawful and unlawful; it also frames possible legal actions against unlawful decisions. What is ultimately at stake is the search for balance between free will and necessary regulation
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Bisson, Jonathan. "Localisation d'agents mobiles physiques." Mémoire, Sherbrooke : Université de Sherbrooke, 2003. http://savoirs.usherbrooke.ca/handle/11143/1182.
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Law, Robin Ren-Pei. "Localisation for virtual environments." Thesis, University of Bath, 2002. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.269674.
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Juanico, Brice. "Localisation d'énergie dans les protéines." Phd thesis, Ecole normale supérieure de lyon - ENS LYON, 2007. http://tel.archives-ouvertes.fr/tel-00266351.
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Afin de mettre en évidence le phénomène de localisation d'énergie dans les protéines, un modèle utilisant les concepts de la Physique non-linéaire a été développé. Il permet, via l'utilisation d'un potentiel de type FPU et d'une dissipation placée sur la surface, de faire apparaître des breathers chaotiques dans certaines enzymes. Ces breathers ont une durée de vie importante par rapport aux échelles de temps caractéristiques du système. Ils sont localisés sur un seul résidu, toujours situé dans une région rigide de la protéine. Cela nous a conduit à l'hypothèse d'un lien possible entre la fonction catalytique, les propriétés locales de structure des enzymes et les localisations d'énergie. Plus précisément, l'activation d'un breather chaotique lors d'une réaction enzymatique au niveau des sites catalytiques pourrait permettre à la protéine de stocker de l'énergie pendant de longues durées.
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Woodman, Oliver. "Pedestrian localisation for indoor environments." Thesis, University of Cambridge, 2010. https://www.repository.cam.ac.uk/handle/1810/228709.
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Ubiquitous computing systems aim to assist us as we go about our daily lives, whilst at the same time fading into the background so that we do not notice their presence. To do this they need to be able to sense their surroundings and infer context about the state of the world. Location has proven to be an important source of contextual information for such systems. If a device can determine its own location then it can infer its surroundings and adapt accordingly. Of particular interest for many ubiquitous computing systems is the ability to track people in indoor environments. This interest has led to the development of many indoor location systems based on a range of technologies including infra-red light, ultrasound and radio. Unfortunately existing systems that achieve the kind of sub-metre accuracies desired by many location-aware applications require large amounts of infrastructure to be installed into the environment. This thesis investigates an alternative approach to indoor pedestrian tracking that uses on-body inertial sensors rather than relying on fixed infrastructure. It is demonstrated that general purpose inertial navigation algorithms are unsuitable for pedestrian tracking due to the rapid accumulation of errors in the tracked position. In practice it is necessary to frequently correct such algorithms using additional measurements or constraints. An extended Kalman filteris developed for this purpose and is applied to track pedestrians using foot-mounted inertial sensors. By detecting when the foot is stationary and applying zero velocity corrections a pedestrian's relative movements can be tracked far more accurately than is possible using uncorrected inertial navigation. Having developed an effective means of calculating a pedestrian's relative movements, a localisation filter is developed that combines relative movement measurements with environmental constraints derived from a map of the environment. By enforcing constraints such as impassable walls and floors the filter is able to narrow down the absolute position of a pedestrian as they move through an indoor environment. Once the user's position has been uniquely determined the same filter is demonstrated to track the user's absolute position to sub-metre accuracy. The localisation filter in its simplest form is computationally expensive. Furthermore symmetry exhibited by the environment may delay or prevent the filter from determining the user's position. The final part of this thesis describes the concept of assisted localisation, in which additional measurements are used to solve both of these problems. The use of sparsely deployed WiFi access points is discussed in detail. The thesis concludes that inertial sensors can be used to track pedestrians in indoor environments. Such an approach is suited to cases in which it is impossible or impractical to install large amounts of fixed infrastructure into the environment in advance.
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Bernal-Merino, Miguel Angel. "The localisation of video games." Thesis, Imperial College London, 2013. http://hdl.handle.net/10044/1/39333.
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The present thesis is a study of the translation of video games with a particular emphasis on the Spanish-English language pair, although other languages are brought into play when they offer a clearer illustration of a particular point in the discussion. On the one hand, it offers a descriptive analysis of the video game industry understood as a global phenomenon in entertainment, with the aim of understanding the norms governing present game development and publishing practices. On the other hand, it discusses particular translation issues that seem to be unique to these entertainment products due to their multichannel and polysemiotic nature, in which verbal and nonverbal signs are intimately interconnected in search of maximum game interactivity. Although this research positions itself within the theoretical framework of Descriptive Translation Studies, it actually goes beyond the mere accounting of current processes to propose changes whenever professional practice seems to be unable to rid itself of old unsatisfactory habits. Of a multidisciplinary nature, the present thesis is greatly informed by various areas of knowledge such as audiovisual translation, software localisation, computer assisted translation and translation memory tools, comparative literature, and video game production and marketing, amongst others. The conclusions are an initial breakthrough in terms of research into this new area, challenging some of the basic tenets current in translation studies thanks to its multidisciplinary approach, and its solid grounding on current game localisation industry practice. The results can be useful in order to boost professional quality and to promote the training of translators in video game localisation in higher education centres.
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Sobnack, M. "Fluid loading and Anderson localisation." Thesis, University of Cambridge, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.386879.
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Csorba, Michael. "Simultaneous localisation and map building." Thesis, University of Oxford, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.244562.
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Williams, Hazel Patricia. "Golgi protein localisation in schizosaccharomyces." Thesis, University College London (University of London), 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.367896.
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Eade, Ethan. "Monocular simultaneous localisation and mapping." Thesis, University of Cambridge, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.611415.
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Goverdovsky, Valentin. "Towards low power radio localisation." Thesis, Imperial College London, 2013. http://hdl.handle.net/10044/1/23903.
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This work investigates the use of super-resolution algorithms for precision localisation and long-term tracking of small subjects, like rodents. An overview is given of a variety of techniques for positioning in use today, namely received signal strength, time of arrival, time difference of arrival and direction of arrival (DoA). Based on the analysis, it is concluded that the direction finding signal subspace based techniques are most appropriate for the purposes of our system. The details of the software defined radio (SDR) antenna array testbed development, build, characterisation and performance evaluation are presented. The results of direction finding experiments in the screened anechoic chamber emulating open-space propagation are discussed. It is shown that such testbed is capable of locating sources in the vicinity of the array with high precision. It can estimate the DoAs of more simultaneously working transmitters than antennas in the array, by employing spread spectrum techniques, and readily accommodates very low power sources. Overall constraints on the system are such that the operational range must be around 50-100 m. The transmitter must be small both volumetrically and in terms of weight. It also has to be operational over an extended period of around 1 year. The implications of these are that very small antennas and batteries must be used, which are usually accompanied by very low transmission efficiencies and tiny capacities, respectively. Based on the above, the use of ultra-low power oscillator transmitters, as first cut prototypes of the tag, is proposed. It is shown that the Clapp, Colpitts, Pierce and Cross-coupled architectures are adequate. A thorough analysis of these topologies is provided with full details of tag and antenna co-design. Finally the performance of these architectures is evaluated through simulations with respect to power output, overall efficiency and phase noise.
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Akbar, Shazia. "Tumour localisation in histopathology images." Thesis, University of Dundee, 2015. https://discovery.dundee.ac.uk/en/studentTheses/c282ab9c-5776-400f-8440-f5ac9cf2f4ba.
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Immunohistochemical (IHC) assessment in cancer research is important for understanding the distribution and localisation of biomarkers at the cellular level. However currently IHC analyses are predominantly performed manually, increasing workloads and introducing inter- and intra-observer variability. Automation shows great potential in clinical research to reduce pathologists' workloads and speed up cancer research in large clinical studies. Whilst recent advancements in digital pathology have enabled IHC measurements to be performed automatically, the acquisition of manual annotations of tumours in scanned digital slides is still a limiting factor. In this thesis, an automated solution to tumour localisation is explored with the aim of replacing manual annotations. As an exemplar, human breast tissue microarrays stained with estrogen receptor are considered. Methods for automated tumour localisation are described with a focus on capturing structural information in tissue by adopting superpixel properties in a rotation invariant manner, suitable for histopathology images. To incorporate essential contextual information, methods which utilise posterior tumour probabilities in an iterative manner are proposed. Results showed pixel-level agreements between automated and manual tumour segmentation masks (κ=0.811) approach inter-rater agreement between expert pathologists (κ=0.908). A large proportion of disagreements between automated and manual segmentations were shown to correlate to minor discrepancies, inconsequential for IHC assessment. IHC scores extracted from automated and manual tumour segmentation masks showed strong agreements (Allred: κˆ=0.911; Quickscore: κˆ=0.922), demonstrating the potential of automation in clinical practice across large clinical trials.
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Aloui, Nadia. "Localisation sonore par retournement temporel." Thesis, Grenoble, 2014. http://www.theses.fr/2014GRENT079/document.
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L'objectif général de cette thèse était de proposer une solution de localisation en intérieur à la fois simple et capable de surmonter les défis de la propagation dans les environnements en intérieur. Pour ce faire, un système de localisation basé sur la méthode des signatures et adoptant le temps d'arrivée du signal de l'émetteur au récepteur comme signature, a été proposé. Le système présente deux architectures différentes, une première orientée privée utilisant la méthode d'accès multiple à répartition par code et une deuxième centralisée basée sur la méthode d'accès multiple à répartition dans le temps. Le système calcule la position de l'objet d'intérêt par la méthode de noyau. Une comparaison expérimentale entre le système à architecture orientée privée et un système de localisation sonore déjà existant et basé sur la méthode de trilatération, a permis de confirmer les résultats trouvés dans le cas de la localisation par ondes radiofréquences. Cependant, nos expérimentations étaient les premières à montrer l'effet de la réverbération sur les approches de la localisation acoustique. Dans un second lieu, un système de localisation basé sur la technique de retournement temporel, permettant une localisation simultanée de sources avec différentes précisions, a été testé par simulations en faisant varier le nombre de sources. Ce système a été ensuite validé par expérimentations. Dans la dernière partie de notre étude, nous nous sommes intéressés à la réduction de l'audibilité du signal utile à la localisation par recours à la psycho-acoustique. Un filtre défini à partir du seuil d'audition absolu a été appliqué au signal de localisation. Nos résultats ont montré une amélioration de la précision de localisation comparé au système de localisation sans modèle psycho-acoustique et ce grâce à l'utilisation d'un filtre adapté au modèle psycho-acoustique à la réception. Par ailleurs, l'écoute du signal après application du modèle psycho-acoustique a montré une réduction significative de son audibilité comparée à celle du signal originalThe objective of this PhD is to propose a location solution that should be simple and robust to multipath that characterizes the indoor environments. First, a location system that exploits the time domain of channel parameters has been proposed. The system adopts the time of arrival of the path of maximum amplitude as a signature and estimates the target position through nonparametric kernel regression. The system was evaluated in experiments for two main configurations: a privacy-oriented configuration with code-division multiple-access operation and a centralized configuration with time-division multiple-access operation. A comparison between our privacy-oriented system and another acoustic location system based on code-division multiple-access operation and lateration method confirms the results found in radiofrequency-based localization. However, our experiments are the first to demonstrate the detrimental effect that reverberation has on acoustic localization approaches. Second, a location system based on time reversal technique and able to localize simultaneously sources with different location precisions has been tested through simulations for different values of the number of sources. The system has then been validated by experiments. Finally, we have been interested in reducing the audibility of the localization signal through psycho-acoustics. A filter, set from the absolute threshold of hearing, is then applied to the signal. Our results showed an improvement in precision, when compared to the location system without psychoacoustic model, thanks to the use of matched filter at the receiver. Moreover, we have noticed a significant reduction in the audibility of the filtered signal compared to that of the original signal
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LAVAUD, PASCAL. "Formule de localisation en supergeometrie." Paris 7, 1998. http://www.theses.fr/1998PA077083.
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Le but de ce travail est d'etendre a la situation supergeometrique la formule de localisation de berline-vergne. Tout d'abord on a etendu la theorie de la cohomologie equivariante a la situation supergeometrique. En particulier on a obtenu un equivalent supergeometrique de la classe de thom et de la classe d'euler pour la cohomologie equivariante a support compact. Pour cela on est amene a considerer non pas la cohomologie equivariante traditionnelle a coefficients polynomiaux mais plutot a coefficients dans les fonctions generalisees. Une fois ce travail effectue, on a trouve une generalisation supergeometrique de la formule de localisation de berline-vergne pour calculer des integrales de formes equivariantes fermees a support compact. Enfin, on a montre a travers divers exemples que cette theorie est bien adaptee au calcul de la transformee de fourier d'une orbite coadjointe d'un supergroupe de lie et que l'on retrouve ainsi certaines formule de caracteres a la kirillov.
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DE, TORO ARIAS SAMUEL. "Dynamique de la localisation d'anderson." Nice, 1998. http://www.theses.fr/1998NICE5221.
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L'objet de cette these concerne la dynamique de la localisation d'anderson unidimensionnelle. En preliminaire a cette etude nous discutons quelques proprietes de la localisation unidimensionnelle. Nous suggerons, en particulier, l'existence de liens entre le phenomene de localisation classique de golosov, pour un marcheur aleatoire dans un environnement aleatoire, et la localisation d'anderson d'origine quantique. Puis, nous etudions la dynamique de la localisation d'anderson au travers de deux situations simples : une particule libre et deux particules en interaction sur une chaine desordonnee. L'etude de la dynamique de la localisation d'une particule libre nous permet de raffiner l'image communement admise selon laquelle l'etalement balistique du paquet d'onde precede le regime de localisation. En plus des regimes balistique et localise, une analyse d'echelle dynamique met en evidence un regime balistique anormal qui survit au dela de la localisation du paquet d'onde. Pour deux particules en interaction, nous montrons l'existence de trois phases dans la dynamique d'anderson. Aux temps courts la mobilite du centre de masse d'une paire de particules est d'abord affaiblie par l'interaction, tandis que l'effet de l'interaction est oppose aux temps plus longs. Dans cette deuxieme phase, la paire se propage de facon coherente et anormalement lente dans un domaine de taille plus grande que la longueur de localisation a une particule. La sous-diffusion anormale de la paire est dictee par la loi t /(lnt/t 1) avec 1/4, 1/2. Finalement, le centre de masse est localise et nous confirmons la dependance du facteur d'accroissement de la longueur de localisation suivant la force du desordre lorsque la multifractalite de la matrice d'interaction est prise en compte. Une partie de ce travail s'appuie sur des simulations numeriques realisees a l'aide d'un modele temporel de propagation d'ondes scalaires ou spinorielles dans un milieu desordonne. La construction generale du modele microscopique est basee sur des processus elementaires qui obeissent a un principe de huyghens discret et satisfont a des symetries fondamentales telles que le renversement temporel ou la reciprocite.
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Lacoin, Hubert. "Désordre et phénomènes de localisation." Paris 7, 2009. http://www.theses.fr/2009PA077137.
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Cette thèse est consacrée à l'étude de différents modèles aléatoires de polymères. On s'intéresse en particulier à l'influence du désordre sur la localisation des trajectoires pour les modèles d'accrochage et pour les polymères dirigés en milieu aléatoire. En plus des modèles classiques dans Zd, nous abordons l'étude de modèles dit hiérarchiques, construits sur une suite de réseaux auto-similaires, très présent dans la littérature physique. Les résultats que nous avons obtenus concernent principalement l'énergie libre et le phénomène de surdiffusivité. En particulier, nous prouvons: (1) la pertinence du désordre à toute température dans pour le modèle d'accrochage désordonné en dimension 1+1, (2) l'occurence d'un désordre très fort à toute température en dimension 1+2 pour les polymères dirigés en milieu aléatoireThis thesis studies models of random directed polymers. We focus on the influence of disorder on localization of the trajectories for pinning model and directed polymers in random environment. In addition to the classical Zd models, we pay a particular attention to so-called hierarchical models, built on a sequence of self-similar lattices, that are frequently studied in the physics literature. The results we obtain concern mainly free energy and superdiffusivity properties. In particular we present the proof that: (1) disorder is relevant at arbitrary high temperature for pinning models in dimension 1+1, (2) very strong disorder holds at all temperature in dimension 1+2 for directed polymers in random environment
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Prodhon, Caroline. "Le problème de localisation-routage." Troyes, 2006. http://www.theses.fr/2006TROY0010.
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Cette thèse porte sur le problème de localisation-routage (Location-Routing Problem – LRP). Il s’agit d’un problème de logistique du transport qui implique deux niveaux de décision : la localisation de dépôts (niveau stratégique) et l’élaboration de tournées de véhicules (niveau tactique ou opérationnel). Ces deux niveaux sont souvent inter-dépendants, mais pour des raisons de simplification, ils sont généralement traités séparément. Or, de récentes recherches ont montré que la prise en compte des futures tournées dans la résolution d’un problème de localisation permettait des gains significatifs sur les coûts totaux. Il existe de nombreuses applications du LRP comme la distribution du courrier, la livraison de colis ou la collecte de déchets. La motivation des travaux développés ici est d’aborder un problème difficile et dans une version encore peu étudiée dans la littérature, comportant des capacités limitées à la fois pour les dépôts à ouvrir et pour les véhicules réalisant les tournées. De plus, des problèmes de taille réaliste sont visés, c’est-à-dire avec un nombre de clients à servir allant jusqu’à 200. Nous proposons des techniques de résolutions prenant en considération l’intégralité du problème, sans décomposition hiérarchique en deux phases, par le biais de méthodes de type heuristique, mais également avec une approche exacte basée sur de nouveaux modèles mathématiques. Tous les algorithmes développés ont été testés et validés sur des jeux d’essais nouveaux ou provenant de la littératureThis thesis concerns the Location-Routing Problem (LRP). This is a transportation problem that combines two levels of decision: depot location (strategic level) and vehicle routing (tactical or operational level). In distribution systems, these levels are often interdependent, but for simplifications, they are generally solved individually. Recent studies have shown that the overall system cost may be reduced if routing decisions are considered when locating depots. There exist various applications for the LRP, like mail distribution, parcel delivery or waste collection. The motivation for the developed studies is to deal with a difficult problem, in a version comprising capacitated depots and capacitated vehicles. Large-scale instances are targeted, i. E. To stay with up to 200 customers to visit. We propose to solve the LRP with techniques that handle the entire problem without hierarchical decomposition in two phases. They consist in heuristic approaches but also in an exact method based on new mathematical formulations. All the proposed algorithms are tested and validated on new instances or on bench-marks from the literature
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DUFETEL, ISABELLE. "Localisation aberrante pyelique d'une surrenale." Amiens, 1989. http://www.theses.fr/1989AMIEM034.
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Savary, Francine. "La stratégie d'implantation des firmes multinationales : le cas de la biscuiterie, de la chocolaterie et de la brasserie." Paris 2, 1986. http://www.theses.fr/1986PA020073.
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A partir d'une analyse fine de la demande au sein des secteurs biscuitier, chocolatier et brassicole sur la periode 1979-1983 dans treize pays de l'o. C. D. E. (royaume-uni, r. F. A, italie, espagne, danemark, irlande, u. E. B. L. , etats-unis, canada, japon, australie et france), la substitution de "nouveaux produits" biscuits sales, barres chocolatees) aux produits traditionnels est mise en evidence. L'emergence de ces nouveaux creneaux parait resulter de l'action des firmes multinationales suivantes: nabisco brands (u. S. A. ), united biscuits (r-uni), generale biscuit (france), bahlsen (r. F. A. ) pour la biscuiterie, mars (u. S. A. ) rowntree-mackintosh (r-uni), cadbury-schweppes (r-uni), nestle (suisse), jacobs suchard (suisse) pour la chocolaterie et heineken (p-bas), united breweries (danemark), guinness (r-uni), b. S. N. (france) pour la brasserie. Si ces multinationales orientent leur environnement; a l'inverse, l'evolution de la demande determine leurs comportements d'investissement. La classification des marches en quatre categories dites "en constitution", "en developpement", "a maturite" et "a quasi-saturation" permet de montrer l'influence exercee par la demande sur les orientations geographiques et l'importance des investissements realises. Toutefois, le caractere reducteur de cette typologie necessite la prise en compte d'autres determinants. Il s'agit de : la nationalite, la taille, le portefeuille d'activites des firmes; le volume, la structure industrielle et les contraintes reglementaires existantes sur un marche donne; la recherche d'economies d'echelle et la concurrence oligopolistique. L'ensemble de ces variables permet d'expliquer les investissements realises par les groupes depuis 1978 et de degager les convergences de leurs strategies d'implantationAn analysis of the demand in the sectors of biscuit, chocolate, and beer during the 1979-1983 period in 13 o. E. C. D. Countries (united-kingdom, west germany, france, italy, spain, denmark, ireland, belgium-luxembourg, united-states, canada, australia, japan), shows a clear substitution of "new products" (crackers, chocolate bars, shandy) to traditional ones. The apparition of these new segments seems to be mainly the result of the action of the following multinational firms: nabisco-brands (u. S. A. ), united biscuit (u-k), generale biscuit (france), bahlsen (w-g. ) in the biscuit sector, mars (u. S. A. ), rowntree-mackintosh (u-k), cadbury-scheppes (u-k), nestle (ch), jacobs suchard (ch) in the chocolate sector and heineken (nederlands), united breweries (denmark), guinness (u-k) and b. S. N. (france) in the brewery sector. If these multinational firms tend to give a specific orientation to their environment, on the contrary, the evolution of the demand shapes their investment behaviours. The classification of the markets in four categories called "in constitution", "in development", "to maturity" and "near-saturation" shows the influence of demand on the geographic directions and the importance (value number) of such investments. However, this typology implies to take others determinants into account: the nationality, size and activities of the firms; as well as the volume, industrial structure and legislative barriers of a given market; the searching of economies of scale and oligopolistic competition. All these variables can explain the investments realised by the firms from 1978 tonow on and pull out the convergences of their implantation strategies
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Toohey, Lachlan. "Full State History Cooperative Localisation with Complete Information Sharing." Thesis, The University of Sydney, 2016. http://hdl.handle.net/2123/16633.
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This thesis presents a decentralised localisation method for multiple robots. We enable reduced bandwidth requirements whilst using local solutions that fuse information from other robots. This method does not specify a communication topology or require complex tracking of information. The methods for including shared data match standard elements of nonlinear optimisation algorithms. There are four contributions in this thesis. The first is a method to split the multiple vehicle problem into sections that can be iteratively transmitted in packets with bandwidth bounds. This is done through delayed elimination of external states, which are states involved in intervehicle observations. Observations are placed in subgraphs that accumulate between external states. Internal states, which are all states not involved in intervehicle observations, can then be eliminated from each subgraph and the joint probability of the start and end states is shared between vehicles and combined to yield the solution to the entire graph. The second contribution is usage of variable reordering within these packets to enable handling of delayed observations that target an existing state such as with visual loop closures. We identify the calculations required to give the conditional probability of the delayed historical state on the existing external states before and after. This reduces the recalculation to updating the factorisation of a single subgraph and is independent of the time since the observation was made. The third contribution is a method and conditions for insertion of states into existing packets that does not invalidate previously transmitted data. We derive the conditions that enable this method and our fourth contribution is two motion models that conform to the conditions. Together this permits handling of the general out of sequence case.
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Yu, Pei. "Agglomération, les stratégies de localisation et co-localisation des firmes multinationales : une application à l'économie chinoise." Paris 1, 2011. http://www.theses.fr/2011PA010052.
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Cette thèse étudie l'effet d'agglomération sur les nouveaux entrants des IDE, les stratégies de localisation et de co-localisation des FMN en Chine. Au niveau industriel, on analyse profondément la distribution géographique des secteurs manufacturiers en Chine en utilisant des outils statistiques. Et puis, par les estimations du Panel classique et du Système GMM, on prouve une relation dynamique et mutuelle entre l'agglomération et les IDE entrants dans ses secteurs de technologies. Au niveau de la firme, on étudie progressivement les stratégies de localisation des FMN. Par intégrer les théories des jeux, de l'organisation, et des économies d'agglomération, et aussi la nouvelle géographie économique, on compare les stratégies de localisation des FMN américaines et européennes dans les secteurs manufacturiers chinois, en utilisant les modèles des choix discrets, y compris le logit conditionnel et le logit structuré. Les hétérogénéités des FMN, les attributs économiques des provinces (villes) d'accueil, la structure géographique, les effets variés d'agglomération, et les types des R&D sont tous considérés. Nos résultats montrent que le processus de localisation des firmes et leurs déterminants varient selon les pays d'origine, les fonctions des filiales et les provinces (ou villes) d'accueil. Les stratégies d'agglomération et de co-localisation sont préférées par les firmes. Par ailleurs, le marché du travail, la demande du marché et l'infrastructure du transport sont également les facteurs importants de localisation.
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Di, San Germano-Flesia Cristina San Germano-Flesia Cristina di. "Localisation d'ondes classiques par le désordre /." [S.l.] : [s.n.], 1988. http://library.epfl.ch/theses/?nr=700.
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Khan, Muhammad Waqas. "Optimised localisation in wireless sensor networks." Thesis, University of Leeds, 2016. http://etheses.whiterose.ac.uk/13399/.
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Wireless sensor networks (WSNs) comprise of tens, hundreds or thousands of low powered, low cost wireless nodes, capable of sensing environmental data such as humidity and temperature. Other than these sensing abilities, these nodes are also able to locate themselves. Different techniques can be found in literature to localise wireless nodes in WSNs. These localisation algorithms are based on the distance estimates between the nodes, the angle estimates between the nodes or hybrid schemes. In the context of range based algorithms, two prime techniques based on the time of arrival (ToA) and the received signal strength (RSS) are commonly used. On the other hand, angle based approach is based on the angle of arrival (AoA) of the signal. A hybrid approach is sometimes used to localise wireless nodes. Hybrid algorithms are more accurate than range and angle based algorithms because of additional observations. Modern WSNs consist of a small group of highly resourced wireless nodes with known locations called anchor nodes (ANs) and a large group of low resourced wireless nodes known as the target nodes (TNs). The ANs can locate themselves through GPS or they may have a predetermined location given to them during network deployment. Based on these known locations and the range/angle estimates, the TNs are localised. Since hybrid algorithms (a combination of RSS, ToA and AoA) are more accurate than other algorithms, a major portion of this thesis will focus on these approaches. Two prime hybrid signal models are discussed: i) The AoA-RSS hybrid model and ii) the AoA-ToA hybrid signal model. A hybrid AoA-ToA model is first studied and is further improved by making the model unbiased and by developing a new weighted linear least squares algorithm for AoA-ToA signal (WLLS-AoA-ToA) that capitalise on the covariance matrix of the incoming signal. A similar approach is taken in deriving a WLLS algorithm for AoA-RSS signal (WLLS-AoA-RSS). Moreover expressions of theoretical mean square error (MSE) of the location estimate for both signal models are derived. Performances of both signal models are further improved by designing an optimum anchor selection (OAS) criterion for AoA-ToA signal model and a two step optimum anchor selection (TSOAS) criterion for AoA-RSS signal model. To bound the performance of WLLS algorithms linear Cramer Rao bounds (LCRB) are derived for both models, which will be referred to as LCRB-AoA-ToA and LCRB-AoA-RSS, for AoA-ToA and AoA-RSS signal models, respectively. These hybrid localisation schemes are taken one step further and a cooperative version of these algorithms (LLS-Coop) is designed. The cooperation between the TNs significantly improves the accuracy of final estimates. However this comes at a cost that not only the ANs but the TNs must also be able to estimate AoA and ToA/RSS simultaneously. Thus another version of the same cooperative model is designed (LLS-Coop-X) which eliminates the necessity of simultaneous angle-range estimation by TNs. A third version of cooperative model is also proposed (LLS-Opt-Coop) that capitalises the covariance matrix of incoming signal for performance improvement. Moreover complexity analysis is done for all three versions of the cooperative schemes and is compared with its non cooperative counterparts. In order to extract the distance estimate from the RSS the correct knowledge of path-loss exponent (PLE) is required. In most of the studies this PLE is assumed to be accurately known, also the same and fixed PLE value is used for all communication links. This is an oversimplification of real conditions. Thus error analysis of location estimates with incorrect PLE assumptions for LLS technique is done in their respective chapters. Moreover a mobile TN and an unknown PLE vector is considered which is changing continuously due to the motion of TN. Thus the PLE vector is first estimated using the generalized pattern search (GenPS) followed by the tracking of TN via the Kalman filter (KF) and the particle filter (PF). The performance comparison in terms of root mean square error (RMSE) is also done for KF, extended Kalman filter (EKF) and PF.
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Sim, Robert. "Mobile robot localisation using learned landmarks." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape10/PQDD_0007/MQ44278.pdf.
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Fourt, Denis. "Détection et localisation des panneaux routiers." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0017/MQ57404.pdf.
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Kendrick, Jackie E. "Strain localisation during dome-building eruptions." Diss., Ludwig-Maximilians-Universität München, 2013. http://nbn-resolving.de/urn:nbn:de:bvb:19-160847.
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Volcanic landscapes often present advantages for people who inhabit the surrounding areas, but the increasing numbers of people threatened by potential activity increases as these settlements grow. It is thus of vital importance to glean as much information as possible by monitoring active volcanoes (including seismicity, ground deformation, gas flux and temperature changes). Although volcanic behaviour can be difficult to predict, precursory information can often be identified retrospectively (once an eruption begins) to help link antecedent behaviour to eruption attributes. Likewise, eruption relics can be used to identify processes in pre-eruptive magma. Additionally, a huge amount of information may be gathered through experimentation on rock and magma samples. This study combines field and analytical studies of natural samples from Volcán de Colima (Mexico), Mount St. Helens (USA) and Soufrière Hills (Montserrat) with high-temperature magma deformation experiments to investigate the processes involved with magma ascent during dome-building eruptions (Figure S-1).
The study of conduit-dwelling magma is of the utmost importance for understanding transitions from effusive to explosive eruptions. Of primary interest is the rheology of highly crystalline magmas that make up the magma column. Rheology is integrally linked to the composition and textural state (porosity, crystallinity) of magma as well as the stress, temperature and strain rate operative during flow. Many studies have investigated the rheology of multi-phase magmas, but in Chapter 2 this is notably linked to the evolution of the physical properties of the magmas; tracing the changes in porosity, permeability, Poisson’s ratio, Young’s modulus during strain dependent magmatic flow. Especially at high strain rates mechanical degradation of the magma samples may supersede magmatic flow and crystal rearrangement as the dominant form of deformation, resulting in lower apparent viscosities than those anticipated from magmatic state. This leads to an evolution of the fracture network to form inhomogeneous distribution of the permeable porous network; with damage zones cutting through areas of densification. In a conduit setting this is analogous to the formation of a dense, impermeable magma plug which would prohibit degassing through the bulk of the magma. Degassing may or may not proceed along conduit margins, and the plug formation could lead to critical overpressures forming in the conduit and result in highly explosive eruption.
During the multi-scale process of strain localisation it is also probable that another previously unforeseen character acts upon magma rheology. Chapter 3 details the first documentation of crystal plasticity in experimentally deformed multi-phase magmas. The extent of the crystal plasticity (evidenced by electron backscatter diffraction (EBSD)) increases with increasing stress or strain, and thus remnant crystals may be used as strain markers. Thus it seems that crystal-plastic deformation plays a significant role in strain accommodation under magmatic conditions. Indeed plastic deformation of phenocrysts in conduit magmas may be an important transitional regime between ductile flow and brittle fracture, and a time-space window for such deformation is envisaged during the ascent of all highly-crystalline magmas. This phenomenon would favour strain localisation and shear zone formation at conduit margins (as the crystal-plastic deformation leads the magma toward brittle failure) and ultimately preferentially result in plug flow.
During volcanic eruptions, the extrusion of high-temperature, high-viscosity magmatic plugs imposes frictional contact against conduit margins in a manner that may be considered analogous to seismogenic faults. During ascent, the driving forces of the buoyant magma may be superseded by controls along conduit margins; where brittle fracture and sliding can lead to formation of lubricating cataclasite, gouge or pseudotachylyte as described in Chapter 4 at Mount St. Helens. Within volcanic systems, background temperatures are significantly higher than the geotherm permits in other upper-crustal locations, whereas confining pressures are much lower than in high-temperature, lower-crustal settings: thus via their exceptional ambient P-T conditions, volcanic systems represent unique environments for faulting. This can result in the near-equilibrium melting and slow recrystallisation of frictional melt, which hinders the development of signature pseudotachylyte characteristics. Thus frictional melting may be more common than previously thought. Indeed Chapter 5 documents a second occurrence at Soufrière Hills volcano. Here, the formation is linked to repetitive seismic “drumbeats” which occurred during both the eruption at Mount St. Helens and at Soufrière Hills. Strain localisation, brittle rupture, sliding and the formation of shear bands along the conduit margin can have important implications for the dynamics of eruptions. Specifically, the capability of degassing via the permeable porous network may be strongly influenced by the formation of pseudotachylyte, which has almost no porosity.
Based on the findings in chapters 4 and 5, a series of high-velocity rotary shear (HVR) experiments were performed. In Chapter 6 the results of these experiments demonstrate the propensity for melting of the andesitic and dacitic material (from Soufrière Hills and Mount St. Helens respectively) at upper conduit stress conditions (<10 MPa). Additionally, frictional melting induces a higher resistance to sliding than rock on rock (which follows Byerlee’s friction coefficient) and thus can act as a viscous brake. Variable-rate HVR experiments which mimic rapid velocity fluctuations during stick-slip motion demonstrate velocity-weakening behaviour of melt, with a tendency for unstable slip. The occurrence of frictional melting can explain the self-regulating, cyclic progression of stick-slip motion during viscous magma ascent and additionally accounts for the fixed-location, repetitive “drumbeats” via the arrival of fresh magma at the source.
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Jagbrant, Gustav. "Autonomous Crop Segmentation, Characterisation and Localisation." Thesis, Linköpings universitet, Institutionen för systemteknik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-97374.
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Orchards demand large areas of land, thus they are often situated far from major population centres. As a result it is often difficult to obtain the necessary personnel, limiting both growth and productivity. However, if autonomous robots could be integrated into the operation of the orchard, the manpower demand could be reduced. A key problem for any autonomous robot is localisation; how does the robot know where it is? In agriculture robots, the most common approach is to use GPS positioning. However, in an orchard environment, the dense and tall vegetation restricts the usage to large robots that reach above the surroundings. In order to enable the use of smaller robots, it is instead necessary to use a GPS independent system. However, due to the similarity of the environment and the lack of strong recognisable features, it appears unlikely that typical non-GPS solutions will prove successful. Therefore we present a GPS independent localisation system, specifically aimed for orchards, that utilises the inherent structure of the surroundings. Furthermore, we examine and individually evaluate three related sub-problems. The proposed system utilises a 3D point cloud created from a 2D LIDAR and the robot’s movement. First, we show how the data can be segmented into individual trees using a Hidden Semi-Markov Model. Second, we introduce a set of descriptors for describing the geometric characteristics of the individual trees. Third, we present a robust localisation method based on Hidden Markov Models. Finally, we propose a method for detecting segmentation errors when associating new tree measurements with previously measured trees. Evaluation shows that the proposed segmentation method is accurate and yields very few segmentation errors. Furthermore, the introduced descriptors are determined to be consistent and informative enough to allow localisation. Third, we show that the presented localisation method is robust both to noise and segmentation errors. Finally it is shown that a significant majority of all segmentation errors can be detected without falsely labeling correct segmentations as incorrect.Eftersom fruktodlingar kräver stora markområden är de ofta belägna långt från större befolkningscentra. Detta gör det svårt att finna tillräckligt med arbetskraft och begränsar expansionsmöjligheterna. Genom att integrera autonoma robotar i drivandet av odlingarna skulle arbetet kunna effektiviseras och behovet av arbetskraft minska. Ett nyckelproblem för alla autonoma robotar är lokalisering; hur vet roboten var den är? I jordbruksrobotar är standardlösningen att använda GPS-positionering. Detta är dock problematiskt i fruktodlingar, då den höga och täta vegetationen begränsar användandet till större robotar som når ovanför omgivningen. För att möjliggöra användandet av mindre robotar är det istället nödvändigt att använda ett GPS-oberoende lokaliseringssystem. Detta problematiseras dock av den likartade omgivningen och bristen på distinkta riktpunkter, varför det framstår som osannolikt att existerande standardlösningar kommer fungera i denna omgivning. Därför presenterar vi ett GPS-oberoende lokaliseringssystem, speciellt riktat mot fruktodlingar, som utnyttjar den naturliga strukturen hos omgivningen.Därutöver undersöker vi och utvärderar tre relaterade delproblem. Det föreslagna systemet använder ett 3D-punktmoln skapat av en 2D-LIDAR och robotens rörelse. Först visas hur en dold semi-markovmodell kan användas för att segmentera datasetet i enskilda träd. Därefter introducerar vi ett antal deskriptorer för att beskriva trädens geometriska form. Vi visar därefter hur detta kan kombineras med en dold markovmodell för att skapa ett robust lokaliseringssystem.Slutligen föreslår vi en metod för att detektera segmenteringsfel när nya mätningar av träd associeras med tidigare uppmätta träd. De föreslagna metoderna utvärderas individuellt och visar på goda resultat. Den föreslagna segmenteringsmetoden visas vara noggrann och ge upphov till få segmenteringsfel. Därutöver visas att de introducerade deskriptorerna är tillräckligt konsistenta och informativa för att möjliggöra lokalisering. Ytterligare visas att den presenterade lokaliseringsmetoden är robust både mot brus och segmenteringsfel. Slutligen visas att en signifikant majoritet av alla segmenteringsfel kan detekteras utan att felaktigt beteckna korrekta segmenteringar som inkorrekta.
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North, Alison Jane. "Spectrin localisation in mammalian striated muscle." Thesis, University of Oxford, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.276872.
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Melgoza, Renato Samperio. "Visual localisation for aibo walking robots." Thesis, University of Essex, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.495774.
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Kelsey, Angela. "Mechanisms for XIST RNA cis-localisation." Thesis, University of British Columbia, 2013. http://hdl.handle.net/2429/44992.
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X inactivation is the process of silencing one of the two X chromosomes in mammalian female cells in order to equalise the dosage of X-linked genes with males. The process is initiated by the long noncoding RNA XIST, which is transcribed from the future inactive X and localises to it in cis. How XIST RNA is able to localise to the X chromosome is not well defined. The aim of the current study was to deduce mechanisms of XIST RNA localisation. This was addressed in various ways, including 1) testing the ability of an XIST transgene integrated into a variety of autosomes to localise to those autosomes, as opposed to the X chromosome; 2) assessing the ability of XIST transgenes with different regions deleted to localise, in order to identify sequences required for localisation; and 3) knocking down various proteins implicated in X inactivation in order to assess any effect on the ability of XIST to localise. We find that the XIST transgene is able to localise to a wide variety of different autosomes and furthermore, is able to direct the enrichment of the histone variant macroH2A on an autosome and the deposition of a repressive histone modification, H3K27me3, onto an autosome. We also find that a region of XIST encompassing repeats B and C, and sequences downstream of exon 1 are involved in localising XIST RNA, and that they do so in a redundant fashion. Lastly, we show that the knockdown of five proteins - YY1, hnRNP-U, SPOP, CUL3 and ASH2L - prevent the formation of an intact XIST focus. The results presented here add to the limited knowledge of how XIST RNA is able to localise, an essential step in the process of X chromosome inactivation.
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Davis, Ilan. "Intracellular message localisation in Drosophila melanogaster." Thesis, University of Oxford, 1990. http://ora.ox.ac.uk/objects/uuid:78b18340-ecf7-4656-b6bd-5ba252728904.
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The blastoderm embryo of Drosophila melanogaster consists of a unicellular syncytium with a large number of peripheral nuclei. The cytoplasm surrounding each peripheral nucleus is compartmentalised into apical periplasm above each nucleus and basal periplasm below it. The expression of different genes in the syncytial blastoderm is crucial for the genetic control of development. The pair-rule genes are involved in controlling the pattern of metamerisation of the embryo. Pair-rule mRNAs are expressed in alternate metameres, in a pattern of stripes. Within each stripe, mRNA is found in the apical periplasm of the syncytial blastoderm. By analysing the distribution of mRNA of a number of hybrid constructs, I show that the 3' untranslated part of three pair-rule genes are required for the apical localisation of their transcripts. A 1.2kb region in the 3' end of fushi tarazu (ftz), a 700bp region in the 3' end of hairy (h) and a 160bp fragment of the 3' untranslated part of the even-skipped (eve) pair-rule gene are shown to contain apical localisation signals. I show that the mechanism of apical localisation is unlikely to involve a cytoplasmic process and that the 3' untranslated part of the bicoid (bed) gene contains sequences necessary for apical localisation. I propose that apical localisation involves a nuclear mechanism which exports mRNA from the apical side of the nuclear membrane. I demonstrate that apical localisation is achieved by an RNA-mediated process and not by a DNA-mediated mechanism. Finally, I demonstrate that the intracellular localisation of transcripts encoding cytoplasmic proteins influences the distribution of the protein in the periplasm. I propose that the function of apical localisation is to limit the diffusion of pair-rule proteins so that the pattern of protein expression resembles precisely the transcriptional domain.
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Mills, Tracey A. "Localisation of sulphate transporters in wheat." Thesis, University of Central Lancashire, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.275925.
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Shuttle, Dawn Alison. "Numerical modelling of localisation in soils." Thesis, University of Manchester, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.277841.
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Saliba, Anthony John. "Auditory-visual integration in sound localisation." Thesis, University of Essex, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.249979.
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Ringel, I. "Structural studies of RNA localisation signals." Thesis, University College London (University of London), 2009. http://discovery.ucl.ac.uk/18926/.
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Asymmetric localisation of cytoplasmic mRNA in the cell appears in a variety of organisms and is important for establishment of spatially differential expression of genes. Localised transcripts typically contain codes (localisation signals), expressed within cis-acting elements that specify subcellular targeting. These signals are recognised by a complex of adaptor and motor proteins that move along the cytoskeleton. Cis-acting elements usually present in the 3'-UTRs of localising transcripts. Different signals do not appear to share either primary or secondary structures that are distinct from non-localising transcripts. Although secondary structure is important, the structural basis of the elements that contribute to the specificity of the localising transcripts is poorly understood. The presented thesis examines the basis of selective RNA transport, by studying the shortest signal known to drive localisation in Drosophila Melanogaster, a 44 nucleotides sequence on the 3' UTR of the fs(1)K10 transcript. This signal is necessary and sufficient for its localisation during embryo development and has a structure of stem loop with two unpaired bases ("bulges"). The components that are important for signal activity are analysed by studying the effect of specific mutations on localisation in the embryo and on the corresponding structure of the RNA. Using NMR structure solution, the importance of the two bulges is demonstrated in wild type and mutated signals and a new structural element of an unusual B-form-like double-stranded RNA helix is revealed. This unusual helix form subsequently been shown to be crucial for the localisation of the K10 transcript. These features might be important as representatives of a general structure that characterise a common group of localising transcripts.
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Rohani, Mohsen. "Méthodes coopératives de localisation de véhicules." Thèse, Université de Sherbrooke, 2015. http://hdl.handle.net/11143/6809.
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Abstract : Embedded intelligence in vehicular applications is becoming of great interest since the last two decades. Position estimation has been one of the most crucial pieces of information for Intelligent Transportation Systems (ITS). Real time, accurate and reliable localization of vehicles has become particularly important for the automotive industry. The significant growth of sensing, communication and computing capabilities over the recent years has opened new fields of applications, such as ADAS (Advanced driver assistance systems) and active safety systems, and has brought the ability of exchanging information between vehicles. Most of these applications can benefit from more accurate and reliable localization. With the recent emergence of multi-vehicular wireless communication capabilities, cooperative architectures have become an attractive alternative to solving the localization problem. The main goal of cooperative localization is to exploit different sources of information coming from different vehicles within a short range area, in order to enhance positioning system efficiency, while keeping the cost to a reasonable level. In this Thesis, we aim to propose new and effective methods to improve vehicle localization performance by using cooperative approaches. In order to reach this goal, three new methods for cooperative vehicle localization have been proposed and the performance of these methods has been analyzed. Our first proposed cooperative method is a Cooperative Map Matching (CMM) method which aims to estimate and compensate the common error component of the GPS positioning by using cooperative approach and exploiting the communication capability of the vehicles. Then we propose the concept of Dynamic base station DGPS (DDGPS) and use it to generate GPS pseudorange corrections and broadcast them for other vehicles. Finally we introduce a cooperative method for improving the GPS positioning by incorporating the GPS measured position of the vehicles and inter-vehicle distances. This method is a decentralized cooperative positioning method based on Bayesian approach. The detailed derivation of the equations and the simulation results of each algorithm are described in the designated chapters. In addition to it, the sensitivity of the methods to different parameters is also studied and discussed. Finally in order to validate the results of the simulations, experimental validation of the CMM method based on the experimental data captured by the test vehicles is performed and studied. The simulation and experimental results show that using cooperative approaches can significantly increase the performance of the positioning methods while keeping the cost to a reasonable amount.Résumé : L’intelligence embarquée dans les applications véhiculaires devient un grand intérêt depuis les deux dernières décennies. L’estimation de position a été l'une des parties les plus cruciales concernant les systèmes de transport intelligents (STI). La localisation précise et fiable en temps réel des véhicules est devenue particulièrement importante pour l'industrie automobile. Les améliorations technologiques significatives en matière de capteurs, de communication et de calcul embarqué au cours des dernières années ont ouvert de nouveaux champs d'applications, tels que les systèmes de sécurité active ou les ADAS, et a aussi apporté la possibilité d'échanger des informations entre les véhicules. Une localisation plus précise et fiable serait un bénéfice pour ces applications. Avec l'émergence récente des capacités de communication sans fil multi-véhicules, les architectures coopératives sont devenues une alternative intéressante pour résoudre le problème de localisation. L'objectif principal de la localisation coopérative est d'exploiter différentes sources d'information provenant de différents véhicules dans une zone de courte portée, afin d'améliorer l'efficacité du système de positionnement, tout en gardant le coût à un niveau raisonnable. Dans cette thèse, nous nous efforçons de proposer des méthodes nouvelles et efficaces pour améliorer les performances de localisation du véhicule en utilisant des approches coopératives. Afin d'atteindre cet objectif, trois nouvelles méthodes de localisation coopérative du véhicule ont été proposées et la performance de ces méthodes a été analysée. Notre première méthode coopérative est une méthode de correspondance cartographique coopérative (CMM, Cooperative Map Matching) qui vise à estimer et à compenser la composante d'erreur commune du positionnement GPS en utilisant une approche coopérative et en exploitant les capacités de communication des véhicules. Ensuite, nous proposons le concept de station de base Dynamique DGPS (DDGPS) et l'utilisons pour générer des corrections de pseudo-distance GPS et les diffuser aux autres véhicules. Enfin, nous présentons une méthode coopérative pour améliorer le positionnement GPS en utilisant à la fois les positions GPS des véhicules et les distances inter-véhiculaires mesurées. Ceci est une méthode de positionnement coopératif décentralisé basé sur une approche bayésienne. La description détaillée des équations et les résultats de simulation de chaque algorithme sont décrits dans les chapitres désignés. En plus de cela, la sensibilité des méthodes aux différents paramètres est également étudiée et discutée. Enfin, les résultats de simulations concernant la méthode CMM ont pu être validés à l’aide de données expérimentales enregistrées par des véhicules d'essai. La simulation et les résultats expérimentaux montrent que l'utilisation des approches coopératives peut augmenter de manière significative la performance des méthodes de positionnement tout en gardant le coût à un montant raisonnable.
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Cully, William Patrick Lloyd. "Received signal strength based person localisation." Thesis, Queen's University Belfast, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.673800.
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This thesis focussed upon the localisation of people and specifically the effect that the human body had upon estimated positions produced by the tested localisation algorithms. These algorithms used the signal strength measured between two nodes to provide ranging information to allow a user's position to be estimated. However, the human body causes non-line of sight situations, termed as the body shadowing effect. This effect is especially important in this work as the node worn by the user took on a smartwatch style form factor worn on the wrist. This natural positioning meant that line of sight between two nodes could be easily blocked by the user's body. Body shadowing caused deviation from the true positions which were generally skewed from the true path depending upon the orientation of the user. These deviations are detailed in this thesis and a number' of approaches were taken to reduce them. Firstly was the implementation of a statistically based localisation algorithm, which incorporated a history of the user's estimated positions into its design. This reduced the erratic trajectories produced, and ensured momentary non-line of sight would have a lesser effect upon estimated trajectories. Secondly was the implementation of line of sight specific channel models which were employed depending upon the user's orientation. Thirdly, two diversity schemes were investigated, polarisation and spatial. Polarisation diversity took on the form of two receivers at each node built into the infrastructure arranged 90° to each other. Spatial diversity saw the user wear two nodes, one on each wrist. Finally an extension to the statistically based localisation algorithm was presented that allowed cooperation between multiple users to enhance their localisation accuracy.
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Mours, Alexis. "Localisation de cible en sonar actif." Thesis, Université Grenoble Alpes (ComUE), 2017. http://www.theses.fr/2017GREAU016/document.
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La connaissance de l'environnement marin est nécessaire pour un grand nombre d'applications dans le domaine de l'acoustique sous-marine comme la communication, la localisation et détection sonar et la surveillance des mammifères marins. Il constitue le moyen principal pour éviter les interférences néfastes entre le milieu naturel et les actions industriels et militaires conduites en zones côtières.Notre travail de thèse se place dans un contexte de sonar actif avec des fréquences allant de 1 kHz à 10 kHz pour des distances de propagations allant de 1 km à plusieurs dizaines de kilomètres. Nous nous intéressons particulièrement aux environnements de propagation grands fonds, à l'utilisation des antennes industrielles comme les antennes de flancs, les antennes cylindriques et les antennes linéaires remorquées, et à l'utilisation de signaux large bande afin de travailler avec des résolutions en distance et en vitesse très élevées. Le travail de recherche présenté dans ce mémoire est dédié à la recherche de nouveaux paramètres discriminants pour la classification de cible sous-marine en sonar actif et notamment à l'estimation de l'immersion instantanée.Cette étude présente : (1) les calculs de nouvelles bornes de Cramer-Rao pour la position d'une cible en distance en et en profondeur, (2) l'estimation conjointe de la distance et de l'immersion d'une cible à partir de la mesure des temps d'arrivées et des angles d'élévations sur une antenne surfacique et (3) l'estimation conjointe de la distance, de l'immersion et du gisement d'une cible à partir de la mesure des temps d'arrivées et des pseudo-gisements sur une antenne linéaire remorquée.Les méthodes développées lors de cette étude ont été validées sur des simulations, des données expérimentales à petite échelle et des données réelles en merThe knowledge of the marine environment is required for many underwater applications such as communications, sonar localization and detection, and marine mammals monitoring. It enables preventing harmful interference between the natural environment and industrial and military actions in coastal areas.This thesis work concentrates upton the context of active sonar with frequencies from 1 kHz to 10 kHz and long propagation ranges from 1 km to several tens of kilometers. We also concentrates upon deep water environment, the use of industrial arrays such as cylindrical arrays, flank arrays and linear towed arrays, and the use of large time-bandwidth signals in order to obtain high distance and speed resolutions. This research work is dedicated to the research of new features for the underwater target classification in active sonar, and specifically to the instantaneous target-depth estimation.This thesis presents: (1) calculations of new Cramer-Rao bounds for the target-position in range and in depth, (2) the joint estimation of the target-depth and the target-range from the arrival time and elevation angle measures with a surface array, (3) the joint estimation of the target-depth, the target-range and the target-bearing from the arrival time and pseudo-bearing angle measures with a linear towed array.The methods presented in this manuscript have been benchmarked on simulation, on reduced-scale experimental data and real marine data
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Raffinot, Mathieu. "Structures pour la localisation de motifs." Université de Marne-la-Vallée, 1999. http://www.theses.fr/1999MARN0061.
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Cette these porte sur un probleme fondamental de l'informatique, celui de localiser un mot p = p 1p 2p m dans un texte t = t 1t 2t n, tous deux des suites de caracteres sur un alphabet. De nombreux algorithmes existent deja pour le resoudre, comme le knuth-morris-pratt et le boyer-moore. De nouveaux algorithmes sont apparus (vers 1992-1994), en utilisant une nouvelle approche. Elle mene, en utilisant un automate des facteurs ou des suffixes, a des algorithmes, comme le backward dawg matching (bdm) ou le turbobdm, optimaux en moyenne, c'est-a-dire, dans un modele d'independance et d'equiprobabilite des lettres, en complexite moyenne o(n log | |(m)/m) (borne inferieure de a. Yao). Malheureusement ces algorithmes sont plutot theoriques, c'est-a-dire tres compliques, tres gourmands en memoire et peu flexibles (i. E nous ne pouvons pas facilement les etendre pour rechercher une structure plus compliquee qu'un mot). Dans cette these, nous montrons comment (apres un premier chapitre de synthese sur l'automate des suffixes) simuler l'automate des suffixes en utilisant le parallelisme intrinseque des registres du microprocesseur. Nous obtenons ainsi l'algorithme bndm de recherche de d'un mot, optimal en moyenne et tres simple a implementer, mais soumis aux limitations des tailles des mots machines. De facon surprenante et inattendue, cet algorithme est facilement extensible aux classes de caracteres et a un petit ensemble de mots, alors que le bdm ne l'est pas. Cette derniere extension permet d'utiliser notre algorithme pour faire des recherches approchees, qui peuvent, en outre, se combiner avec l'extension aux classes de caracteres. Nous proposons ensuite dans notre troisieme chapitre une nouvelle structure construite a partir du mot p, nommee oracle des facteurs. Cette structure a des proprietes plus faibles que celles de l'automate des suffixes (au lieu de reconnaitre exactement les facteurs, elle en reconnait un sur-ensemble), mais est beaucoup plus simple a construire et occupe beaucoup moins de place memoire. En utilisant cette structure a la place de l'automate des suffixes, nous obtenons des algorithmes de recherche d'un mot aussi efficaces en moyenne (conjectures optimaux) mais plus simples a implementer et beaucoup moins gourmands en place memoire. Dans le quatrieme chapitre, nous obtenons une estimation du nombre moyen d'etats terminaux dans les automates des suffixes en faisant appel a des methodes recentes developpees en analyse asymptotique. Toujours dans le cadre d'une recherche efficace d'un mot dans un texte, un recent courant de pensees a conduit a essayer de rechercher plus rapidement des mots dans des textes compresses que dans l'original. Nous cherchons dans notre cinquieme chapitre a obtenir des algorithmes pratiques efficaces de recherche de mots sur des textes compresses par un algorithme de la famille ziv-lempel. Nous presentons des developpements theoriques accompagnes de resultats experimentaux de performances. Nous etendons ensuite certains de nos algorithmes pour rechercher un ensemble de mots. Nous commencons dans le sixieme chapitre par faire une synthese des algorithmes existants. Nous developpons de nouveaux algorithmes, comme le sbdm, et ameliorons de diverses facons le multibdm pour le rendre efficace en pratique. Nous etendons enfin dans le huitieme et dernier chapitre notre structure d'oracle des facteurs a un ensemble de mots, et nous l'utilisons a la place de l'automate des suffixes dans nos algorithmes. Les resultats experimentaux montrent que les algorithmes obtenus sont les plus efficaces en pratique des que la taille minimale des mots est assez grande (tout en restant petite, de l'ordre de 7 a 10 caracteres, suivant la taille de l'alphabet). Nous avons implementes nos nouveaux algorithmes dans un programme, appele ogrep, le o pour oracle qui rivalise avec les meilleurs logiciels, notamment agrep de wu et manber
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Heiles, Baptiste. "Microscopie par Localisation Ultrasonore en 3D." Thesis, Paris Sciences et Lettres (ComUE), 2019. https://pastel.archives-ouvertes.fr/tel-02953081.
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La microscopie par localization ultrasonore a montré qu’il était possible de s’affranchir du compromis entre la penetration et la resolution en échographie grâce aux ultrasons ultrarapides et à l’utilisation d’agents de contraste. Cependant, cette technique sera difficilement transposable dans un environment clinique car elle implique : 1. de longs temps d’acquisitions, 2. un champ de vue limité à un plan, 3. l’impossibilité de corriger les mouvements hors plan, 4. des quantités de données importantes et 5. des temps de calculs extrêmement longs. En développant cette technique en 3 dimensions, il sera possible d’explorer des volumes anatomiques entiers en quelques minutes d’acquisition afin de voir la microvasculature mais aussi d’imager des organes soumis au mouvement (comme cela est le cas pour l’imagerie d’un patient).L’objectif de cette thèse a été de démontrer qu’il était possible de faire de la microscopie par localization ultrasonore en 3D sur des larges volumes, et de montrer son potentiel in vitro et in vivo. Le point de depart a été de developer des nouvelles techniques de localisation de particules, ce qui a permis de diviser par 300 le temps de calcul en 2D et de fournir une imagerie de meilleure qualité. Grâce à leur implémentation en 3 dimensions, elles ont rendu possible la microscopie par localization ultrasonore en 3D dans des temps réduits. Ensuite, nous avons créé des sequences d’imagerie 4D spécifiques pour la microscopie en 3D et montré qu’il était possible d’imager avec une résolution sub longueur d’onde un fantôme de canaux microfluidiques 3D. Ce fantôme a été développé spécifiquement pour démontrer la faisabilité de la technique en 3D. Après avoir éprouvé notre technique in vitro, nous l’avons appliquée in vivo sur le cerveau de rat et démontré qu’il était possible d’avoir accès à la vasculature ainsi qu’aux flux sanguins à une échelle de quelques microns. Une étape supplémentaire a été ajoutée dans le framework de l’algorithme afin de corriger le mouvement en 3 dimensions et de recaler des volumes superrésolus entre eux afin de produire le premier volume d’un cerveau de rat entier (bulbe olfactif, cervelet et lobes principaux).Le développement de la microscopie par localisation ultrasonore en 3D ouvre la voie vers une imagerie préclinique in vivo de meilleure qualité et plus rapide. Grâce aux innovations technologiques actuelles, l’utilisation de cette technique en recherche se fera de plus en plus fréquente jusqu’à être adoptée en cliniqueUltrasound Localization Microscopy has demonstrated the ability to overcome the penetration/resolution conundrum in ultrasound imaging thanks to high frame rate imaging and contrast agents. However, this approach will fall short in its clinical translation if its main disadvantages aren’t addressed: 1- long time of acquisition 2- limited two dimensional field of view 3- motion artifacts 4-data overdose and 5- data processing times. Developing 3D ULM will allow to explore entire volumes within a few minutes of acquisition, giving access to all blood vessels down to micrometer size and imaging moving organs (i.e. a patient in a clinical setting).The objective of this thesis was to perform, for the first time, volumetric ultrasound localization microscopy and unveil its potential in-vitro and in-vivo. For this purpose, I first developed new post-processing techniques, reducing 2D data processing times by a factor of 300, allowing implementation of ULM on 3D data and increasing image quality. Then, I implemented new ultrasound sequences and demonstrated that sub-wavelength features could be resolved in a tailor made wall-less phantom. I then demonstrated that 3D imaging of the rat brain microvasculature with blood flow velocimetry was achievable with micrometric resolution, and implemented 3D motion correction and image registration to provide whole brain imaging.This new tool was used to investigate both the anatomy and the vascularization mechanisms in the brain. Making the transition from 2D ULM to 3D ULM paves the way towards better imaging of in vivo organs in the rat. Thanks to technological improvements 3D ULM will spread fast in research imaging and reach all the way to clinical care
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Gaspard, François. "Localisation et calibration avec un zoom." Nice, 2001. http://www.theses.fr/2001NICE5612.
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Considérant l’émergence de systèmes visuels actifs monoculaires à focale variable, nous nous intéressons, dans cette thèse, au formalisme et aux équations qui permettent d’obtenir une perception visuelle de la géométrie et de la cinématique d’une scène 3D. L’utilisation d’une caméra équipée d’un zoom présente de nombreux intérêts, d’une part au niveau de la précision et de la robustesse des algorithmes basés sur l’utilisation d’un tel capteur, et, d’autre part, au niveau des propriétés géométriques du mouvement engendré lors d’une variation de focale. La pris en compte des spécificités physiques des paramètres conduits, par ailleurs, à la mise en place d’algorithmes de minimisation non linéaire adaptés au problème considéré. Enfin, l’observation de structures planes permet, lorsque le motif est connu a priori, de déterminer la position du plan par rapport à la caméra et de déduire des équations sur la calibration de la caméraConsidering the emergence of active visual systems with variable focal length, this thesis focuses on the paradigm allowing the visual perception of object geometry and cinematic properties. Since zooming consists not only in intrinsic parameters variations, but also in an optical center position translation such a camera is of interest considering both the geometric properties of such a displacement and the contribution to the measure precision. Nonlinear implicit equations are frequently minimized in computer vision either to estimate a parameter from an initial guess ot to refine a previous linear estimation. In such configurations, the local minimum of interest and the initial guess are rather close. We thus present a specific method for the minimization of such nonlinear implicit equations, based on both a complete specification of the parameters and a randomized algorithm. Finally, considering known planar structures allow to recover the 3D position of a plane and to obtain two equations according to the intrinsic parameters