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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
91

On Their Own: The Single Woman, Feminism, and Self-Help in British Women's Print Culture (1850-1900)

Walker, Melissa 08 May 2012 (has links)
Cultural and historical accounts of self-help literature typically describe its development and focus in terms of the autonomous, public male subject of the nineteenth century. This literary study recognizes that as masculine self-help discourse became widely accessible in the mid nineteenth century, mid-Victorian feminist novels, periodicals, and tracts developed versions of self-help that disrupted the dominant cultural view that the single female was helpless and “redundant” if she did not become a wife and mother. I argue that the dual focus of Victorian self-help discourse on the ability to help oneself and others was attractive for Victorian feminist writers who needed to manipulate the terms of the domestic ideal of woman as influential helpmeet, if women’s independence and civic duty were to be made culturally palatable. Chapter One focuses on how Dinah Mulock Craik drew on self-help values popularized in mid-century articles and collective biographies by Samuel Smiles, while rejecting the genre of biography for its invasiveness into female lives. By imagining a deformed single artist heroine in the context of her 1851 bildungsroman, Olive, Craik highlighted and contested the objectification of women within Victorian culture while reproducing other forms of female difference based on dominant constructions of class, sexuality, and race. Chapter Two extends formal and thematic considerations of self-help discourse to a comparison of masculine colonial accounts of class-climbing and the projection of a self-reliant, yet deeply unstable, domestic female by Maria Rye and the Female Middle-Class Emigration Society. Chapter Three exerts critical pressure on the tension between individual and mutual help by charting the debate that raged between liberal individualism and collectivism in the labour movement, particularly in The Women’s Union Journal. Returning to a focus on the binary of female aberrance and normalcy within Victorian culture, Chapter Four analyzes late-century case studies of nervous illnesses alongside Ella Hepworth Dixon’s 1894 New Woman novel that promoted self-help for women as desirable yet unattainable in a society still largely structured around the domestic ideal. At its broadest, this dissertation explores points of convergence and departure between Victorian masculine and feminine self-help texts, and touches on reverberations of this Victorian discourse in today’s self-help works directed at women in Western culture.
92

冗長関節アームの協調動作のためのUCM参照フィードバック制御法

UNO, Yoji, KAGAWA, Takahiro, TOGO, Shunta, 宇野, 洋二, 香川, 高弘, 東郷, 俊太 02 1900 (has links)
No description available.
93

Motion planning for redundant manipulators and other high degree-of-freedom systems

Keselman, Leo 22 May 2014 (has links)
Motion planning for redundant manipulators poses special challenges because the required inverse kinematics are difficult and not complete. This thesis investigates and proposes methods for motion planning for these systems that do not require inverse kinematics and are potentially complete. These methods are also compared in performance to standard inverse kinematics based methods.
94

Block Transmissions On Orthogonal Carriers

Yazici, Ayhan 01 September 2005 (has links) (PDF)
Orthogonal Frequency Division Multiplexing (OFDM) and Single Carrier Block Transmissions (SCBT) are located at the two opposite edges of block transmission concept. In this thesis a system which lies between OFDM and SCBT is proposed. The new system, namely Block Transmissions on Orthogonal Carriers (BTOC), can be considered as a hybrid form of OFDM and SCBT. BTOC system is investigated under the redundant filterbank precoders and equalizers framework. Peak to average power ratio (PAPR) of BTOC is formulated and compared with the PAPRs of OFDM and SCBT. Effect of frequency offset for BTOC is investigated and comparison between OFDM, SCBT, and BTOC is presented. Simulation results of Zero Padded OFDM (ZP-OFDM), SCBT, and BTOC are included.
95

Hybrid cable thruster-actuated underwater vehicle manipulator system : modeling, analysis and control / Modélisation, étude et commande d'un robot sous-marin à câbles

Elghazaly, Gamal 12 June 2017 (has links)
L’industrie offshore, pétrolière et gazière est le principal utilisateur des robots sous-marins, plus particulièrement de véhicules télé-opérés (ou ROV, Remotely Operated Vehicle). L'inspection, la construction et la maintenance de diverses installations sous-marines font parties des applications habituelles des ROVs dans l’industrie offshore. La capacité à maintenir un positionnement stable du véhicule ainsi qu’à soulever et déplacer des charges lourdes est essentielle pour certaines de ces applications. Les capacités de levage des ROVs sont cependant limitées par la puissance de leur propulsion. Dans ce contexte, cette thèse présente un nouveau concept d’actionnement hybride constitué de câbles et de propulseurs. Le concept vise à exploiter les fortes capacités de levage des câbles, actionnés par exemple depuis des navires de surfaces, afin de compléter l’actionnement d’un robot sous-marin. Plusieurs problèmes sont soulevés par la nature hybride (câbles et propulseurs) de ce système d'actionnement. En particulier, nous étudions l’effet de l'actionnement supplémentaire des câbles par rapport à un actionnement exploitant uniquement des propulseurs et nous tâchons de minimiser les efforts exercés par ces derniers. Ces deux objectifs sont les principales contributions de cette thèse. Dans un premier temps, nous modélisons la cinématique et la dynamique d'un robot sous-marin actionné à la fois par des propulseurs et des câbles et équipé d'un bras manipulateur. Un tel système possède une redondance cinématique et d'actionnement.. L'étude théorique sur l'influence de l'actionnement supplémentaire par câbles est appuyée par une étude en simulation, comparant les capacités de force d'un système hybride (câbles et propulseurs) à celles d'un système actionné uniquement par des propulseurs. L'évaluation des capacités est basée sur la détermination de l'ensemble des forces disponibles, en considérant les limites des forces d'actionnement. Une nouvelle méthode de calcul est proposée, pour déterminer l'ensemble des forces disponibles. Cette méthode est basée sur le calcul de la projection orthogonale de polytopes et son coût calculatoire est analysé et comparé à celui d'une méthode de l’état de l’art. Nous proposons également une nouvelle méthode pour le calcul de la distribution des forces d'actionnement, permettant d'affecter une priorité supérieure au sous-système d'actionnement par câbles afin de minimiser les efforts exercés par les propulseurs. Plusieurs cas d'études sont proposés pour appuyer les méthodes proposées. / The offshore industry for oil and gas applications is the main user of underwater robots, particularly, remotely operated vehicles (ROVs). Inspection, construction and maintenance of different subsea structures are among the applications of ROVs in this industry. The capability to keep a steady positioning as well as to lift and deploy heavy payloads are both essential for most of these applications. However, these capabilities are often limited by the available on-board vehicle propulsion power. In this context, this thesis introduces the novel concept of Hybrid Cable-Thruster (HCT)-actuated Underwater Vehicle-Manipulator Systems (UVMS) which aims to leverage the heavy payload lifting capabilities of cables as a supplementary actuation for ROVs. These cables are attached to the vehicle in a setting similar to Cable-Driven Parallel Robots (CDPR). Several issues are raised by the hybrid vehicle actuation system of thrusters and cables. The thesis aims at studying the impact of the supplementary cable actuation on the capabilities of the system. The thesis also investigate how to minimize the forces exerted by thrusters. These two objectives are the main contributions of the thesis. Kinematic, actuation and dynamic modeling of HCT-actuated UVMSs are first presented. The system is characterized not only by kinematic redundancy with respect to its end-effector, but also by actuation redundancy of the vehicle. Evaluation of forces capabilities with these redundancies is not straightforward and a method is presented to deal with such an issue. The impact of the supplementary cable actuation is validated through a comparative study to evaluate the force capabilities of an HCT-actuated UVMS with respect to its conventional UVMS counterpart. Evaluation of these capabilities is based on the determination of the available forces, taking into account the limits on actuation forces. A new method is proposed to determine the available force set. This method is based on the orthogonal projection of polytopes. Moreover, its computational cost is analyzed and compared with a standard method. Finally, a novel force resolution methodology is introduced. It assigns a higher priority to the cable actuation subsystem, so that the forces exerted by thrusters are minimized. Case studies are presented to illustrate the methodologies presented in this thesis.
96

Optimal motion planning in redundant robotic systems for automated composite lay-up process / Planification des mouvements optimaux dans les systèmes robotiques redondants pour un processus d'enroulement filamentaire composite automatisée

Gao, Jiuchun 29 June 2018 (has links)
La thèse traite de la planification des mouvements optimaux dans les systèmes robotiques redondants pour l'automatisation des processus d’enroulement filamentaire. L'objectif principal est d'améliorer la productivité des cellules de travail en développant une nouvelle méthodologie d'optimisation des mouvements coordonnés du robot manipulateur, du positionneur de pièce et de l'unité d'extension de l'espace de travail. Contrairement aux travaux précédents, la méthodologie proposée offre une grande efficacité de calcul et tient compte à la fois des contraintes technologiques et des contraintes du système robotique, qui décrivent les capacités des actionneurs et s'expriment par les vitesses et accélérations maximales admissibles dans les articulations actionnées. La technique développée est basée sur la conversion du problème continu original en un problème combinatoire, où toutes les configurations possibles des composants mécaniques sont représentées sous la forme d'un graphe multicouche dirigé et le mouvement temporel optimal est généré en utilisant le principe de programmation dynamique. Ce mouvement optimal correspond au plus court chemin sur le graphique satisfaisant les contraintes de lissage. Les avantages de la méthodologie développée sont confirmés par une application industrielle d’enroulement filamentaire pour la fabrication de pièces thermoplastiques au CETIM. / The thesis deals with the optimal motion planning in redundant robotic systems for automation of the composite lay-up processes. The primary goalis to improve the lay-up workcell productivity by developing a novel methodology of optimizing coordinated motions of the robotic manipulator,workpiece positioner and workspace extension unit,which ensure the shortest processing time and smooth movements of all mechanical components. In contrast to the previous works, the proposed methodology provides high computational efficiencyand also takes into account both the technological constraints and the robotic system constraints, which describe capacities of the actuators and are expressed by the maximum allowable velocities and accelerations in the actuated joints. The developed technique is based on conversion of the original continuous problem into a combinatorial one, where all possible configurations of the mechanical components are represented as a directed multi layergraph and the desired time-optimal motion is generated using dynamic programming principle for searching the shortest path on the graph satisfying the smoothness constraints. It is also proposed an enhancement of this technique by dividing the optimization procedure in two stages combining global and local searches. At the first stage, the developed algorithm is applied in the global search space generated with large discretization step. Then,the same technique is applied in the local search space, which is created with smaller step in the neighborhood of the obtained trajectory. The advantages of the developed methodology are confirmed by industrial implementation on the factory floor that deals with manufacturing of the high pressure vessel.
97

Force equalization for active/active redundant actuation system involving servo-hydraulic and electro-mechanical technologies / Stratégie d'égalisation d'effort dans les systèmes d'actionnement actif-actif impliquant les technologies servo-hydraulique et électro-mécanique

Wang, Lijian 18 December 2012 (has links)
L'évolution vers les avions plus électriques engendre des efforts importants pour développer des actionneurs à source de puissance électrique pour les commandes de vol. Pour de telles applications critiques, il est peut être intéressant dans le futur d'associer à une même surface de contrôle un actionneur conventionnel à source de puissance hydraulique et un actionneur à source de puissance électrique mais ceci pose un problème important lorsque les deux actionneurs sont actifs simultanément: comme chacun essaye d'imposer sa position à l'autre,les deux actionneurs luttent l'un contre l'autre en développant des efforts néfastes qui ne sont pas utilisés par la charge. L'objet du présent travail est de proposer des stratégies d’égalisation d’effort pour un système d'actionnement impliquant ces deux types d''actionneurs opérant en mode actif-actif. La première étape est de concevoir leur commande en position et de la valider sur banc d'essai. Un banc d'essai virtuel fidèle à la réalité est ensuite réalisé dans l'environnement de simulation AMESim pour pouvoir évaluer facilement les différentes stratégies d'égalisation d'effort entre les deux actionneurs. Ces stratégies sont proposées et évaluées virtuellement en deux étapes, statique puis dynamique. Pour finir, une étude de robustesse est réalisée a posteriori pour évaluer la sensibilité des indicateurs de performance aux incertitudes sur les modèles de simulation et sur les points et les conditions de fonctionnement. / On the way to more electric aircraft (MEA), more and more power-by-wire (PBW) actuators are involved in the flight control system. For a hybrid redundant actuation system composed by the conventional hydraulically powered actuators and the PBW actuators, one major issue while they operate on active/active mode is the force fighting between channels. As the grave influence of force fighting on accelerating material fatigue and increasing power consumption,it must be addressed with attention. This thesis was aiming at proposing some effective force equalization control strategies for the hybrid actuation system involving one servo-hydraulic actuator (SHA) and one electro-mechanical actuator (EMA). For this objective, the position controllers for SHA and EMA were designed and validated as a first step. Then, a virtual test bench regarding to the realistic behaviors was built in the AMESim simulation environment to accelerate the controller design and enable the robustness study. Following this, 2 static force equalization control strategies were proposed and experimentally validated. The first strategy hat introduced integral force fighting signal to compensate the actuator position control was proved a good candidate solution. In the next part, 3 dynamic force equalization strategies were proposed and assessed on the virtual test bench. Their performance sensitivities to the parameter uncertainties were studied through Monte-Carlo method. The first strategy that introduced velocity and acceleration feed-forwards to force the SHA and EMA having similar pursuit dynamics showed a good force equalization performance as well as good segregation and good robustness. In the end, the work presented in thesis was concluded and perspective was given to the ongoing work.
98

Adaptive Hierarchical RAID

Muppalaneni, Nitin 01 1900 (has links) (PDF)
No description available.
99

Efficient Fault Tolerance In Chip Multiprocessors Using Critical Value Forwarding

Subramanyan, Pramod 06 1900 (has links) (PDF)
Relentless CMOS scaling coupled with lower design tolerances is making ICs increasingly susceptible to transient faults, wear-out related permanent faults and process variations. Decreasing CMOS reliability implies that high-availability systems which were previously restricted to the domain of mainframe computers or specially designed fault-tolerant systems may be come important for the commodity market as well. In this thesis we tackle the problem of enabling efficient, low cost and configurable fault-tolerance using Chip Multiprocessors (CMPs). Our work studies architectural fault detection methods based on redundant execution, specifically focusing on “leader-follower” architectures. In such architectures redundant execution is performed on two cores/threads of a CMP. One thread acts as the leading thread while the other acts as the trailing thread. The leading thread assists the execution of the trailing thread by forwarding the results of its execution. These forwarded results are used as predictions in the trailing thread and help improve its performance. In this thesis, we introduce a new form of execution assistance called critical value forwarding. Critical value forwarding uses heuristics to identify instructions on the critical path of execution and forwards the results of these instructions to the trailing core. The advantage of critical value forwarding is that it provides much of the speed up obtained by forwarding all values at a fraction of the bandwidth cost. We propose two architectures to exploit the idea of critical value forwarding. The first of these operates the trailing core at lower voltage/frequency levels in order to provide energy-efficient redundant execution. In this context, we also introduce algorithms to dynamically adapt the voltage/frequency level of the trailing core based on program behavior. Our experimental evaluation shows that this proposal consumes only 1.26 times the energy of a non-fault-tolerant baseline and has a mean performance overhead of about 1%. We compare our proposal to two previous energy-efficient fault-tolerant CMP proposals and find that our proposal delivers higher energy-efficiency and lower performance degradation than both while providing a similar level of fault coverage. Our second proposal uses the idea of critical value forwarding to improve fault-tolerant CMP throughput. This is done by using coarse-grained multithreading to mul-tiplex trailing threads on a single core. Our evaluation shows that this architecture delivers 9–13% higher throughput than previous proposals, including one configuration that uses simultaneous multithreading(SMT) to multiplex trailing threads. Since this proposal increases fault-tolerant CMP throughput by executing multiple threads on a single core, it comes at a modest cost in single-threaded performance, a mean slowdown between11–14%.
100

Vlnková filtrace signálů EKG / Wavelet Filtering of ECG Signals

Handl, Marek January 2013 (has links)
The work deals with the wavelet transformation, focusing on wavelet transforms with discrete time (DTWT). The practical part is focused on the implementation of redundant packet DTWT and its use in the filtration of ECG signals. The main part of the work is to design wiener filter that uses redundant packet DTWT, designed to eliminate interference myopotentials of ECG signals. The actual solution is implemented in Matlab. Testing is performed on the library CSE using noise model myopotentials used to noising original signals. For optimum parameters designed filter is used the genetic algorithm (GA). The work is carried out comparing the proposed filter redundant packet DTWT a variant of redundant dyadic DTWT.

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