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PROGRAMMATION AVANCEE DES MACHINES OUTILS :<br>IMPLEMENTATION DE L'USINAGE TROCHOIDAL ET DU TREFLAGE DANS LA CHAINE NUMERIQUE STEP-NCLaguionie, Raphael 01 October 2007 (has links) (PDF)
L'augmentation de la productivité sur machine à commande numérique passe, entre autre, par l'amélioration de la programmation de celles-ci. Le langage sur lequel se base actuellement cette programmation date du début des années 80 avec la norme 6983 qui définit les principes du code G. Ce dernier présente certains inconvénients aux vues des nouvelles stratégies d'usinage et crée une rupture de la chaîne numérique au niveau de la fabrication. Un nouveau format émergeant, le STEP-NC, voit le jour actuellement dans le but de palier aux manques du code G et d'intégrer complètement la chaîne CAO-FAO-CN. <br />Nos travaux ont pour objectif d'implanter deux nouvelles stratégies d'usinage, le tréflage et l'usinage trochoïdal, au sein du format STEP-NC. Pour ceci, nous nous basons sur une description des trajectoires à l'aide de courbes à motif. La construction de ces courbes se fait par répétition d'un motif le long d'une courbe guide. Pour mettre en avant la faisabilité de l'implantation de ces stratégies à motifs dans le format STEP-NC, nous avons développé une chaîne numérique complète permettant, à partir du modèle CAO, de créer le fichier STEP-NC, de générer les trajectoires et d'usiner la pièce sur machine à commande numérique. Une partie de l'intégration de l'usinage trochoïdal et du tréflage dans le format STEP-NC a été réalisé par implémentation dans le logiciel PosSFP, en collaboration avec le laboratoire de l'université de Postech en Corée. Plusieurs pièces tests ont ensuite été usinées pour valider l'ensemble de la chaîne numérique STEP-NC complète dans le cas de l'usinage trochoïdal.
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Etude experimentale de non-linearites optiques dispersives dans un milieu d'atomes pieges par laser .Grelu, Philippe 18 January 1996 (has links) (PDF)
Ce memoire presente une contribution a la recherche de nouveaux milieux non-lineaires pour l'optique quantique. L'objectif final consiste a pouvoir controler les fluctuations quantiques d'un faisceau laser au moyen d'un dispositif de mesure quantique-non-destructif (qnd). Une etude experimentale a ete effectuee concernant les proprietes quantiques des diodes laser, puisque l'utilisation de ces dernieres, comme faisceaux de signal et de mesure couples par un dispositif qnd, a ete envisagee. On montre que leurs fluctuations quantiques d'intensite peuvent etre reduites en dessous du bruit de photon a temperature ambiante, mais qu'un large exces de bruit de phase subsiste dans tous les cas, ce qui empeche leur utilisation immediate dans une experience interferometrique sensible au bruit quantique. Un piege magneto-optique d'atomes de rubidium alimente par un jet atomique ralenti par laser est realise experimentalement. Nous mettons en evidence un couplage classique entre deux faisceaux laser pompe et sonde, au moyen du milieu d'atomes pieges, qui est un milieu resonnant pour lequel l'elargissement doppler est negligeable devant la largeur naturelle de l'etat excite. Afin d'exalter les non-linearites obtenues et permettre un couplage sensible aux fluctuations quantiques des deux faisceaux, les atomes pieges sont entoures d'une cavite interferometrique. Divers regimes de bistabilite a un faisceau sont mis en evidence. Nous etudions enfin comment la perturbation provenant des faisceaux de piegeage peut etre contournee en realisant, par controle du pompage optique, un mode de fonctionnement sombre du piege pour lequel la majeure partie de la population atomique se trouve sur un niveau qui n'est pas couple a ces faisceaux .
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Réalisation et caractérisation de mesures quantiques non-destructives en optique .Poizat, Jean-Philippe 10 June 1993 (has links) (PDF)
L'objectif d'un dispositif de mesure qnd est de contrôler l'action en retour, imposée par la mécanique quantique, qui se produit sur un système soumis a une mesure. Il est, en effet, possible de rejeter cette perturbation entièrement sur l'observable complémentaire de celle mesurée, laissant cette dernière inchangées. Nous présentons ici, de manière détaillée, un ensemble de critères quantitatifs permettant d'évaluer les performances d'un dispositif mesurant l'intensité d'un faisceau lumineux. Ces critères permettent en particulier de séparer clairement des domaines classique et quantique de fonctionnement d'un tel dispositif. La première expérience realisee utilise le couplage par effet kerr croise de deux faisceaux laser dans un milieu non linéaire. Ce milieu est compose d'un jet atomique de sodium place dans une cavite optique doublement résonnante. Nous avons effectue une analyse théorique complète des proprietes de bruit quantique d'un tel système. Nous avons identifie un régime de paramètres, base sur des effets de déplacement lumineux, pour lequel il existe un transfert efficace d'information du faisceau incident vers la voie de mesure, sans dégradation appréciable du signal. Ces prévisions théoriques ont ensuite été vérifiées dans notre expérience. Nous présentons également une deuxième expérience utilisant la détection puis la réémission de la lumière par des composants optoélectroniques a semi-conducteur. Nous montrons que lorsque les taux de conversion photon-électron pour les photodiodes et électron-photon our les diodes electro-luminescentes sont proches de l'unité, ce dispositif permet de mesurer puis de recréer les fluctuations quantiques du faisceau incident. La démonstration de principe que nous avons realisee laisse présager des applications possibles dans le domaine des réseaux de télécommunication optique.
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UM MODELO DE REDES DE MAPAS ACOPLADOS PARA UM SISTEMA PRAGA-PREDADOR-INSETICIDA / COUPLED MAP LATTICE MODEL FOR AN PREY-PREDATOR-INSECTICIDE SYSTEMCereser, Henrique Bevilaqua 24 August 2016 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This research is inserted in the Biomathematics Research Group of the Programa de
Pós-Graduação em Matemática of the Universidade Federal de Santa Maria-RS. It
consists in the study of a discrete model for a prey-predator-insecticide system based
on the Coupled Map Lattice as basic tool for its formulation. Due to the serious
problems that crop pests represent to agriculture, we aproached the Integrated Pest
Management (IPM), which is a pest control system that seeks to preserve and enhance
the natural mortality factors of pests by integrated use of control methods selected
based on technical, economic, ecological and sociological parameters. The objective
of this work is to build a model as simple as possible to study the effects of different
pests management strategies. These strategies are divided into different treatments
which take into account the number of measurements of pest population, establishing control levels (CL) and different control measures (pesticide and biological control).
For comparison and to point where the treatment is more efficient to compute the
total density of the pest population without any control measure and when each
treatment is applied over a certain period of time. The difference between these values
is converted into a decreasing percentage of the population of pests. The same is done to obtain the percentage decrease in the number of treated sites. It was found that
the sooner you apply the insecticide in the system, the more effective the treatment.
Furthermore, it was observed that the presence of predators (biological control) decreases
the amount of treated sites and, in some instances, is less effective in controlling pest. / Esta pesquisa está inserida na Linha de Pesquisa Biomatemática, do Programa de Pós-Graduação em Matemática da Universidade Federal de Santa Maria-RS. Configura-se como um estudo sobre um modelo discreto para um sistema praga-predador-inseticida
tendo como ferramenta básica para sua formulação a Rede de Mapas Acoplados. Devido aos sérios problemas que pragas de lavoura representam para agricultura, abordou-se o
Manejo Integrado de Pragas (MIP), que é um sistema de controle de pragas que busca preservar e aumentar os fatores de mortalidade natural de pragas pelo uso integrado
de métodos de controle selecionados com base em parâmetros técnicos, econômicos, ecológicos e sociológicos. O objetivo deste trabalho é construir um modelo tão simples quanto possível, para estudar as consequências de diferentes estratégias de manejos de pragas. Essas estratégias são divididas em tratamentos diferentes nos quais leva-se em consideração o número de medições da população de pragas, estabelecimento de níveis de
controle (NC) e diferentes medidas de controle aplicadas (inseticida e controle biológico).
Para comparar e apontar qual dos tratamentos é mais eficiente, computou-se a densidade
total da população de pragas sem nenhuma medida de controle e quando cada um dos tratamentos é aplicado ao longo de um determinado período de tempo. A diferença entre esses valores é convertida em um percentual de decrescimento da população de
pragas. O mesmo é feito para se obter o percentual de decrescimento do número de sítios tratados. Foi possível constatar que quanto mais cedo se aplica o inseticida no sistema,
mais efetivo é o tratamento. Além disso, observou-se que a presença dos predadores (controle biológico) diminui a quantidade de sítios tratados e, em alguns momentos, é
menos eficiente no controle da praga.
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Social causality in motion : Visual bias and categorization of social interactions during the observation of chasing in infancyGalazka, Martyna A. January 2017 (has links)
Since the seminal work of Fritz Heider and Marienne Simmel (1944) the study of animacy perception, or the perception and attribution of life from the motion of simple geometrical shapes has intrigued researchers. The intrigue for psychologists and vision scientists then and today centered on the stark disconnect between the simplicity of the visual input and the universal richness of the resulting percept. Infant research in this domain has become critical in examining the ontological processes behind the formation of animated percepts. To date, little is known about how infants process these kinds of stimuli. While numerous habituation studies have shown sensitivity to animate motion in general, none to date has examined whether infants actually perceive animate displays as social interactions. The overarching goal of the present thesis is to answer this question and further augment knowledge about the mechanisms behind the formation of animated percepts in infancy. I, along with my collaborators, do so in three ways, in three separate studies. First, we examined visual attention during online observation of randomly moving geometrical shapes in adults and infants (Study I, using eye tracking). Second, we examine distribution of visual attention in infancy during online observation of non-contact causal interactions, focusing on the most ubiquitous, fitness relevant of interactions – chasing (Study II, using eye tracking). Third, we answer the question whether infants perceive social content in chasing displays by measuring the neural correlates in response to chasing (Study III, using EEG). The collective contribution of the present work is also three fold. First, it demonstrates that starting at the end of the first year of life, human visual system is sensitive to cues that efficiently predict an interaction. Second, at 5-months infants begins allocating attention differently across agents within interactions. Finally, attention to specific objects is not due to low-level saliency but the social nature of the interaction. Subsequently, I present the case that perception of social agents is fast, direct, and reflects the workings of a specialized learning mechanisms whose function is the detection of heat-seeking animates in motion.
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NC-SCORE : EN UTVECKLING AV STOCK SELECTION FOR THE DEFENSIVE INVESTOR PÅ DEN SVENSKA AKTIEMARKNADENAndersson, Nils, Hjelmqvist, Carl January 2020 (has links)
The purpose of this study was to develop a new investment strategy called NC-Score. The strategy is based on Chapter 14 of The Intelligent Investor written by Benjamin Graham, but with other key figures and criteria. The key figures were chosen on the basis of creating a varied and comprehensive picture of the companies as possible. They describe the companies' valuation, profitability, growth, cash flows, and capital structure. The strategy was tested between 2011 and 2020 at OMX Stockholm Large Cap. An index and Graham's original strategy have been used to compare NC-Score's performance during the period. The purpose of the index was to emulate the market and act as a minimum requirement for returns. Graham's portfolio gives a picture of how a similar strategy performs under the same conditions. The result for the strategy was a high return at a lower risk than our benchmark index and the original Graham strategy. Between 2011 and 2020, NC-Score generated a return of 191.67% with a Sharpe Ratio of 2.70. During the same period, OMX Stockholm 30 GI generated a return of 110.48% with a Sharpe Ratio of 0.91. NC-Score's results cannot be considered to be significantly positively risk-adjusted since it cannot be ruled out that the higher return in relation to the risk was due to a coincidence. / Syftet med denna studie var att utveckla en ny investeringsstrategi som benämns NC-Score. Strategin utgår ifrån kapitel 14 av The Intelligent Investor skriven av Benjamin Graham, fast med andra nyckeltal och kriterier. Nyckeltalen valdes med utgångspunkt att skapa en varierande och så omfattande bild av bolaget som möjligt. De beskriver bolagens värdering, lönsamhet, tillväxt, kassaflöden samt kapitalstruktur. Strategin testades mellan 2011 och 2020 på OMX Stockholm Large Cap. Ett index samt Grahams ursprungliga strategi har använts för att jämföra prestationen av NC-Score under tidsperioden. Indexets syfte var att efterlikna marknaden och agera som ett minimikrav för avkastningen. Grahams portfölj ger en bild av hur en liknande strategi presterar under samma förutsättningar. Resultatet för strategin var en hög avkastning till en lägre risk än vårt jämförelseindex samt den ursprungliga Graham strategin. Mellan 2011 till 2020 genererade NC-Score en avkastning på 191,67% med en Sharpe Ratio på 2,70. Under samma period genererade OMX Stockholm 30 GI en avkastning på 110,48% med en Sharpe Ratio på 0,91. NC-Scores resultat kan inte anses vara signifikant positivt riskjusterad, då det inte kan uteslutas att den högre avkastningen i förhållande till risk berott på slumpen.
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Mitteilungen des URZ 2/1997Bobber, Gerber, Graupner, Huebner, Mueller, Sontag, Voigt 29 July 1997 (has links)
Intranet - Erwartungen und Entwicklungen
JavaOS - ein Betriebssystem fuer Intranets
Network Computer - Eine Verkaufsstrategie? Was gibt es schon?
Netscape IFC's - Gestalten von graphische Nutzerinterfaces
WWW-Sicherheitsaspekte - ein heisses Thema: Sicherheit im Netz
Aufbau einer Certification Authority - z.B. IN e.V. Chemnitz
Authentisierung und Verteilung von Konfigurationsfiles - am Bsp. URZ
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Ghosts of Our Past: Neutrino Direction Reconstruction Using Deep Neural NetworksStjärnholm, Sigfrid January 2021 (has links)
Neutrinos are the perfect cosmic messengers when it comes to investigating the most violent and mysterious astronomical and cosmological events in the Universe. The interaction probability of neutrinos is small, and the flux of high-energy neutrinos decreases quickly with increasing energy. In order to find high-energy neutrinos, large bodies of matter needs to be instrumented. A proposed detector station design called ARIANNA is designed to detect neutrino interactions in the Antarctic ice by measuring radio waves that are created due to the Askaryan effect. In this paper, we present a method based on state-of-the-art machine learning techniques to reconstruct the direction of the incoming neutrino, based on the radio emission that it produces. We trained a neural network with simulated data, created with the NuRadioMC framework, and optimized it to make the best possible predictions. The number of training events used was on the order of 106. Using two different emission models, we found that the network was able to learn and generalize on the neutrino events with good precision, resulting in a resolution of 4-5°. The model could also make good predictions on a dataset even if it was trained with another emission model. The results produced are promising, especially due to the fact that classical techniques have not been able to reproduce the same results without having prior knowledge of where the neutrino interaction took place. The developed neural network can also be used to assess the performance of other proposed detector designs, to quickly and reliably give an indication of which design might yield the most amount of value to the scientific community. / Neutriner är de perfekta kosmiska budbärarna när det kommer till att undersöka de mest våldsamma och mystiska astronomiska och kosmologiska händelserna i vårt universum. Sannolikheten för en neutrinointeraktion är dock liten, och flödet av högenergetiska neutriner minskar kraftigt med energin. För att hitta dessa högenergetiska neutriner måste stora volymer av materia instrumenteras. Ett förslag på en design för en detektorstation kallas ARIANNA, och är framtagen för att detektera neutrinointeraktioner i den antarktiska isen genom att mäta radiopulser som bildas på grund av Askaryan-effekten. I denna rapport presenterar vi en metod baserad på toppmoderna maskininlärningstekniker för att rekonstruera riktningen på en inkommande neutrino, utifrån den radiostrålning som produceras. Vi tränade ett neuralt nätverk med simulerade data, som skapades med hjälp av ramverket NuRadioMC, och optimerade nätverket för att göra så bra förutsägelser som möjligt. Antalet interaktionshändelser som användes för att träna nätverket var i storleksordningen 106. Genom att undersöka två olika emissionsmodeller fann vi att nätverket kunde generalisera med god precision. Detta resulterade i en upplösning på 4-5°. Modellen kunde även göra goda förutsägelser på en datamängd trots att nätverket var tränat med en annan emissionsmodell. De resultat som metoden framtog är lovande, särskilt med avseende på att tidigare klassiska metoder inte har lyckats reproducera samma resultat utan att metoden redan innan vet var i isen som neutrinointeraktionen skedde. Nätverket kan också komma att användas för att utvärdera prestandan hos andra designförslag på detektorstationer för att snabbt och säkert ge en indikation på vilken design som kan tillhandahålla mest vetenskapligt värde.
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Pristine and Doped Titanium Dioxide Studied by NC-AFMBechstein, Ralf 02 February 2009 (has links)
A commercial non-contact atomic force microscope was improved to achieve utmost resolution on a routine basis. This system was used to study the (110) surface of rutile titanium dioxide. The focus was on understanding contrast formation in terms of tip-sample interaction mechanisms. Moreover, chromium and antimony-doped titanium dioxide was investigated. The implications of transition-metal doping on the surface structure of this highly interesting photocatalyst was studied at the atomic scale.
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双腕ロボットによるプレート2軸旋回運動制御の運動誤差測定とその改善に関する研究 / ソウワン ロボット ニヨル プレート 2ジク センカイ ウンドウ セイギョ ノ ウンドウ ゴサ ソクテイ ト ソノ カイゼン ニカンスル ケンキュウ呉 魏, Wei Wu 22 March 2014 (has links)
本研究は,双腕で作業プレートを支持することで閉リンク機構を構成し,作業プレートを操ることで十分な支持剛性を維持しながらプレート上での柔軟な作業空間を実現することを目指した.すなわち,ロボットでも従来の工作機械のNC制御の運動精度に近い性能を具現化する一方,人の作業に近い柔軟性を両立することであるその対象としてプレート上で球の転がりを取り上げ,その運動軌跡をコンピュータシミュレーションにより解析しながら,同時2軸の旋回運動の制御におけるその誤差解析およびその改善手法を確立する. / Recently, industrial dual-arm robots have gained attention as novel tools and we therefore focus on them to flexible control both the linear motion and the rotational motion of a working plate. However, it is difficult to measure the synchronous accuracy of two rotary axes without high accuracy gyro sensor. Thus, we proposed a novel method to measure it with a ball, which keeps a ball rolling around a circular path on it by dual-arm cooperative control. As a result, we demonstrated this method made it feasible to estimate the synchronous accuracy of two rotary axes of working plate. / 博士(工学) / Doctor of Philosophy in Engineering / 同志社大学 / Doshisha University
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