Cette thèse propose des contributions très prometteuses au sujet du choix des primitives visuelles en asservissement visuel utilisant les moments 2D extraits de l’image. Nous avons proposé une nouvelle manière de résoudre un problème important en asservissement visuel, à savoir la commande du mouvement de rotation suivant les axes orthogonaux à l’axe optique. Ce travail représente une amélioration significative des travaux précédents en asservissement visuel basé sur l’utilisation des moments 2D extraits de l’image pour commander les degrés de liberté des robots manipulateurs. La commande la plus utilisée est connue sous le nom de commande cinématique. L’approche emploie un descripteur global d’image basé sur des moments 2D "shifted" dont les invariants calculés à partir de ces moments 2D "shifted" utilisent des moments d’ordre faible connus pour être robustes au bruit. De plus, ces invariants choisis ne dépendant pas de la forme de l’objet, sont invariants au mouvement de translation, de rotation et d’échelle. Cette nouvelle façon de faire vient ainsi résoudre les problèmes vus dans les travaux précédents relatifs aux choix des combinaisons des moments invariants basés sur les moments centrés et qui dépendent de la forme de l’objet considéré. Dans les travaux précédents, ces invariants sont calculés avec des moments dont l’ordre est compris entre trois et cinq qui sont vulnérables aux bruits de mesure. D’un point de vue asservissement visuel, le travail est basé sur la détermination explicite de la matrice d’interaction calculée à partir des moments 2D "shifted" dont le choix des paramètres de décalages respectent les propriétés d’invariances aux mouvements de translation, de rotation et d’échelle. En procédant ainsi, les informations visuelles choisies montrent la capacité de représenter les objets de formes symétriques et non symétriques. Des résultats de simulations sont présentés pour illustrer la validité de notre proposition. / This thesis proposes nice and very promising contributions about the choice of visual features in image moments-based visual servoing. We proposed a new way towards solving an important problem in Visual Servoing, namely control of non-optic axis rotational degrees of freedom. This work represents a significant improvement respect to previous works on image-based visual servoing of robot manipulators, with the camera in-hand configuration and under the control scheme known as kinematic control. The approach uses global image features that are based on shifted image moments of a planar target. The improvement consists in a particular selection of a combination of shifted image moments of low order such that they do not depend on the planar target shape ; thus solving the problem seen in related previous works where the selection of central or regular image moments combinations depended on the planar target shapes. From a visual servoing point of view, the work is based on the explicit resolution of the interaction matrix related to any shifted image moment, on the appropriate combination of these moments and on the proper selection of the shifted parameters. By doing so, the new features show improved ability to represent symmetrical objects and several kinds of objects defined from closed contours or from a set of points. Six visual features are selected to design a decoupled control scheme when the object is parallel to the image plane. This nice property is then generalized to the case where the desired object position is not parallel to the image plane. Finally simulated results are presented to illustrate the validity of our proposal.

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A humidity fiber optic sensor based on phase-shifted (PS) Fiber Bragg gratings (FBG) is demonstrated. Compared to the standard FBG sensors, the peak of the PS-FBG slips into 2 narrow peaks and forms a sharp dip in the middle. As a result, the resolution of the measurement will be higher. The sensors used in the experiments were fabricated by coating the PS-FBG surface with a moisture-sensitive polyimide and is based on the strain effect caused by the swelling of the coating after moisture absorption. The same trend seen in a standard FBG sensor can be achieved, but with higher measurement resolution in environments differing by humidity and temperature. This thesis presents simulation and measurement results, including sensitivity and response time, of the PS-FBG sensor approach for humidity sensing, as compared to the standard FBG sensors. Stability and hysteresis are also discussed.

Abstract¡G Taiwan has been suffering from a series of severe earthquake disaster. Especially in 921 Earthquake. To deal with such a disastrous situation, government implemented the new plans for the quake-ravaged areas, such as the guiding principle of 921 disaster recovery. This study is attempted to program Industry Reconstruction of post- earthquake in the disaster area. The research method of this research is consisted of data analysis and SWOT Analysis. The research results have indicated: 1.The government plays an important role in the process of Industry Reconstruction. In the entire process of industry reconstruction, from the rescue at the early stage to the replacement of industry reconstruction, it is inevitably that the role of government would be the main influence of industry reconstruction effectiveness. However, in the meanwhile, because of the urge of becoming a member of WTO, it had caused the rate of the unemployment increased and some small businesses closing down. People had economically undertaken all the domestic pressures of becoming a member of WTO, and yet now the government had to face another problem, industry reconstruction in the quake-ravaged areas. It seems that it would be much harder for the government to overcome all at once, therefore, a series of well-related policy is needed, such as the guiding of job-shifted for farmers and style-shifted of agriculture, the strategic alliance of the agriculture association, the promotion of Tourism and the construction of the specific industry in the quake-ravaged areas. Those policies should be concerned in regarding to post-earthquake recovery. 2.The people participation in the reconstruction progress After 921 earthquake, it is obviously that government had difficulty to undertake all issues domestically and internationally. Therefore, it found that the participation of people in the post earthquake recovery would be necessary. Indeed, with the participation of people, it can speed up the process of the recovery. As a result, the participation of people in the quake- ravaged areas was seriously required to the re-development of the specific local industry. 3.The style-shifted of industry and resource integration Since Taiwan had put efforts on becoming a member of WTO in order to increase its products more competitive in the atmosphere of international trade, the style-shifted of Industry would be necessary in avoidance to elimination of the potential domestic industry. For example, when the style-shifted, from agriculture to agricultural Industry, had occurred, the needs of machines in Agriculture would be increased in order to reduce the cost of agriculture production. As a consequence, the agriculture production would become more competitive in international trade and it would increase GDP in a sense. Therefore, promoting the number of experts in relation to the knowledge of agriculture from government would be the prior in order to increase the competitiveness in international trade.

A humidity fiber optic sensor based on phase-shifted (PS) Fiber Bragg gratings (FBG) is demonstrated. Compared to the standard FBG sensors, the peak of the PS-FBG slips into 2 narrow peaks and forms a sharp dip in the middle. As a result, the resolution of the measurement will be higher. The sensors used in the experiments were fabricated by coating the PS-FBG surface with a moisture-sensitive polyimide and is based on the strain effect caused by the swelling of the coating after moisture absorption. The same trend seen in a standard FBG sensor can be achieved, but with higher measurement resolution in environments differing by humidity and temperature. This thesis presents simulation and measurement results, including sensitivity and response time, of the PS-FBG sensor approach for humidity sensing, as compared to the standard FBG sensors. Stability and hysteresis are also discussed.

No description available.

As the world's energy use continues to grow, the development of clean distributed generation becomes increasingly important. Fuel cells are an environmentally friendly renewable energy source that can be used in a wide range of applications and are ideal for distributed power applications. In this study, the power conversion element of a dual single-phase, 10 kW stand-alone fuel cell system is analyzed. The modular converter consists of a DC-DC front-end cascaded with a half-bridge inverter. The entire system is accurately modeled, to help determine any interactions that may arise. Control strategies based on simplicity, performance, and cost are evaluated. A simple voltage loop, with careful consideration to avoid transformer saturation, is employed for the phase-shifted DC-DC converter. Several experimental transfer functions were measured to confirm the modeling assumptions and verify the control design of the DC-DC converter. Two control options for the inverter are explored in detail, and experimental results confirm that the modulation index must be controlled to regulate the output voltage during various load conditions. The final system is implemented without the use of current sensors, thus keeping the inverter cost down. Experimental results using a power supply are given for resistive, inductive, and nonlinear loads and the performance is acceptable. Fuel cell test results, including transient response, are also displayed and analyzed. / Master of Science

Le trafic vidéo a subi une augmentation fulgurante sur Internet ces dernières années. Pour pallier à cette importante demande de contenu vidéo, la technologie du streaming adaptatif sur HTTP est utilisée. Elle est devenue par ailleurs très populaire car elle a été adoptée par les différents acteurs du domaine de la vidéo streaming. C’est une technologie moins couteuse qui permet aux fournisseurs de contenu, la réutilisation des serveurs web et des caches déjà déployés. En plus, elle est exempt de tout blocage car elle traverse facilement les pare-feux et les translations d’adresses sur Internet. Dans cette thèse, nous proposons une nouvelle méthode de vidéo streaming adaptatif appelé “Backward-Shifted Coding (BSC)”. Il se veut être une solution complémentaire au standard DASH, le streaming adaptatif et dynamique utilisant le protocole HTTP. Nous allons d’abord décrire ce qu’est la technologie BSC qui se base sur le codec (encodeur décodeur) à multi couches SVC, un algorithme de compression extensible ou évolutif. Nous détaillons aussi l’implémentation de BSC dans un environnement DASH. Ensuite,nous réalisons une évaluation analytique de BSC en utilisant des résultats standards de la théorie des files d’attente. Les résultats de cette analyse mathématique montrent que le protocole BSC permet de réduire considérablement le risque d’interruption de la vidéo pendant la lecture, ce dernier étant très pénalisant pour les utilisateurs. Ces résultats vont nous permettre de concevoir des algorithmes d’adaptation de qualité à la bande passante en vue d’améliorer l’expérience utilisateur. Ces algorithmes permettent d’améliorer la qualité de la vidéo même étant dans un environnement où le débit utilisateur est très instable.La dernière étape de la thèse consiste à la conception de stratégies de caching pour optimiser la transmission de contenu vidéo utilisant le codec SVC. En effet, dans le réseau, des serveurs de cache sont déployés dans le but de rapprocher le contenu vidéo auprès des utilisateurs pour réduire les délais de transmission et améliorer la qualité de la vidéo. Nous utilisons la programmation linéaire pour obtenir la solution optimale de caching afin de le comparer avec nos algorithmes proposés. Nous montrons que ces algorithmes augmentent la performance du système tout en permettant de décharger les liens de transmission du réseau cœur. / Due to the growth of video traffic over the Internet in recent years, HTTP AdaptiveStreaming (HAS) solution becomes the most popular streaming technology because ithas been succesfully adopted by the different actors in Internet video ecosystem. Itallows the service providers to use traditional stateless web servers and mobile edgecaches for streaming videos. Further, it allows users to access media content frombehind Firewalls and NATs.In this thesis we focus on the design of a novel video streaming delivery solutioncalled Backward-Shifted Coding (BSC), a complementary solution to Dynamic AdaptiveStreaming over HTTP (DASH), the standard version of HAS. We first describe theBackward-Shifted Coding scheme architecture based on the multi-layer Scalable VideoCoding (SVC). We also discuss the implementation of BSC protocol in DASH environment.Then, we perform the analytical evaluation of the Backward-Sihifted Codingusing results from queueing theory. The analytical results show that BSC considerablydecreases the video playback interruption which is the worst event that users can experienceduring the video session. Therefore, we design bitrate adaptation algorithms inorder to enhance the Quality of Experience (QoE) of the users in DASH/BSC system.The results of the proposed adaptation algorithms show that the flexibility of BSC allowsus to improve both the video quality and the variations of the quality during thestreaming session.Finally, we propose new caching policies to be used with video contents encodedusing SVC. Indeed, in DASH/BSC system, cache servers are deployed to make contentsclosed to the users in order to reduce network latency and improve user-perceived experience.We use Linear Programming to obtain optimal static cache composition tocompare with the results of our proposed algorithms. We show that these algorithmsincrease the system overall hit ratio and offload the backhaul links by decreasing thefetched content from the origin web servers.

We study the problem of proving lower bounds for depth four arithmetic circuits. Depth four circuits have been receiving much attraction when it comes to recent circuit lower bound results, as a result of the series of results culminating in the fact that strong enough lower bounds for depth four circuits will imply super-polynomial lower bounds for general arithmetic circuits, and hence solve one of the most central open problems in algebraic complexity i.e a separation between the VP and VNP classes. However despite several efforts, even for general arithmetic circuits, the best known lower bound is Omega(N log N) by Baur and Strassen (1983), where N is the number of input variables. In the case of arithmetic formulas, Kalorkoti (1985) proved a lower bound that is quadratic in the number of input variables, which has not seen any improvement since then. The situation for depth three arithmetic circuits was also similar for many years, until a recent result by Kayal et. al. (2016) achieved an almost cubic lower bound that improved over the previous best quadratic bound by Shpilka and Wigderson (1999). As the main contribution of this thesis, we prove an Omega(N^1.5) lower bound on the size of a depth four circuit, for an explicit multilinear N-variate polynomial in VNP with degree d = Theta(sqrt(N)). Our approach offers a potential route to proving a super-quadratic lower bound for depth four circuits. Taking cue from the numerous successful results recently, we use the technique of the shifted partial derivatives measure to achieve the said lower bound. Particularly, we use the Dimension of Projected Shifted Partials (DPSP) measure which has been previously used in recent depth four results. Coming to the choice of the hard polynomial, we again follow the status quo and use a variant of the Nisan-Wigderson (NW) polynomial family that has proved to be very helpful over the past few years in arithmetic circuit complexity. Finally, we do a careful analysis of Shoup-Smolensky (1997) and Raz (2010) and compare their techniques to ours. We conclude that our result can potentially be used as a starting point, and techniques similar to Kayal et. al. (2016) can likely be used to strengthen our lower bound to Omega(N^2.5), for general depth four arithmetic circuits. However, unlike depth three circuits, proving a super-quadratic lower bound for depth four circuits remains a prevalent open problem for many years. Previous work like Shoup-Smolensky and Raz implied super-linear lower bounds. To the best of our knowledge, the previous best known lower bound for general depth four circuits is Omega(N^1.33).

International Telemetering Conference Proceedings / October 26-29, 1998 / Town & Country Resort Hotel and Convention Center, San Diego, California / In any satellite communication, the Doppler shift associated with the satellite’s position and velocity must be calculated in order to determine the carrier frequency. If the satellite state vector is unknown then some estimate must be formed of the Doppler-shifted carrier frequency. One elementary technique is to examine the signal spectrum and base the estimate on the dominant spectral component. If, however, the carrier is spread (as in most satellite communications) this technique may fail unless the chip rate-to-data rate ratio (processing gain) associated with the carrier is small. In this case, there may be enough spectral energy to allow peak detection against a noise background. In this paper, we present a method to estimate the frequency (without knowledge of the Doppler shift) of a spread-spectrum carrier assuming a small processing gain and binary-phase shift keying (BPSK) modulation. Our method relies on a simple, averaged discrete Fourier transform along with peak detection. We provide simulation results indicating the accuracy of this method. In addition, we will describe an all-digital hardware design based around a Motorola DSP56303 and high-speed A/D which implements this technique in real-time. The hardware design is to be used in NMSU’s implementation of NASA’s demand assignment, multiple access (DAMA) service.