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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.
181

USING THE AMD TAXI CHIPS IN A PARALLEL TO FIBER INTERFACE

Broffel, Robert W. 10 1900 (has links)
International Telemetering Conference Proceedings / October 25-28, 1999 / Riviera Hotel and Convention Center, Las Vegas, Nevada / To meet the security constraints for mission control rooms; the rooms must interface to other systems via fiber optic cable. Analog data from DAC (Digital to Analog Converter) outputs were initially brought into the rooms on copper wire. This paper outlines the conversion to fiber optic cable using the AMD TAXI chips in our Optical Digital Interface (ODI).
182

SIMULATED PERFORMANCE OF SERIAL CONCATENATED LDPC CODES

Panagos, Adam G. 10 1900 (has links)
International Telemetering Conference Proceedings / October 20-23, 2003 / Riviera Hotel and Convention Center, Las Vegas, Nevada / With the discovery of Turbo Codes in 1993, interest in developing error control coding schemes that approach channel capacity has intensified. Some of this interest has been focused on lowdensity parity-check (LDPC) codes due to their high performance characteristics and reasonable decoding complexity. A great deal of literature has focused on performance of regular and irregular LDPC codes of various rates and on a variety of channels. This paper presents the simulated performance results of a serial concatenated LDPC coding system on an AWGN channel. Performance and complexity comparisons between this serial LDPC system and typical LDPC systems are made.
183

MAINTAINING SIGNAL FIDELITY WHILE USING A PACKETIZED TRANSPORT SYSTEM

Hankey, Robert L., Krasinski, Kevin 10 1900 (has links)
International Telemetering Conference Proceedings / October 18-21, 2004 / Town & Country Resort, San Diego, California / Packetizing data for transport over a networked system corrupts embedded information such as absolute and relative timing from the data. Without this information, it is difficult to reproduce the data with its original timing restored. Absolute timing is the time between data points within a given channel of data. Relative timing is the time relationship between data points from two or more channels of data. Having this restored timing allows the use of existing equipment for analysis and eliminates the need for expensive custom designed equipment to analyze the recovered data. Using a packetizing solution that transports information about the data stream and transport packets that are broken up by system wide timing allows us to accomplish this.
184

Analysis and design on low-power multi-Gb/s serial links

Hu, Kangmin 06 July 2011 (has links)
High speed serial links are critical components for addressing the growing demand for I/O bandwidth in next-generation computing applications, such as many-core systems, backplane and optical data communications. Due to continued process scaling and circuit innovations, today's CMOS serial link transceivers can achieve tens of Gb/s per pin. However, most of their reported power efficiency improves much slower than the rise of data rate. Therefore, aggregate I/O power is increasing and will exceed the power budget if the trend for more off-chip bandwidth is sustained. In this work, a system level statistical analysis of serial links is first described, and compares the link performance of Non-Return-to-Zero (2-PAM) with higher-order modulation (duobinary) signaling schemes. This method enables fast and accurate BER distribution simulation of serial link transceivers that include channel and circuit imperfections, such as finite pulse rise/fall time, duty cycle variation, and both receiver and transmitter forwarded-clock jitter. Second, in order to address link power efficiency, two test chips have been implemented. The first one describes a quad-lane, 6.4-7.2 Gb/s serial link receiver prototype using a forwarded clock architecture. A novel phase deskew scheme using injection-locked ring oscillators (ILRO) is proposed that achieves greater than one UI of phase shift for multiple clock phases, eliminating phase rotation and interpolation required in conventional architectures. Each receiver, optimized for power efficiency, consists of a low-power linear equalizer, four offset-cancelled quantizers for 1:4 demultiplexing, and an injection-locked ring oscillator coupled to a low-voltage swing, global clock distribution. Measurement results show a 6.4-7.2Gb/s data rate with BER < 10⁻¹² across 14 cm of PCB, and an 8Gb/s data rate through 4cm of PCB. Designed in a 1.2V, 90nm CMOS process, the ILRO achieves a wide tuning range from 1.6-2.6GHz. The total area of each receiver is 0.0174mm², resulting in a measured power efficiency of 0.6mW/Gb/s. Improving upon the first test chip, a second test chip for 8Gb/s forwarded clock serial link receivers exploits a low-power super-harmonic injection-locked ring oscillator for symmetric multi-phase local clock generation and deskewing. Further power reduction is achieved by designing most of the receiver circuits in the near-threshold region (0.6V supply), with the exception of only the global clock buffer, test buffers and synthesized digital test circuits at nominal 1V supply. At the architectural level, a 1:10 direct demultiplexing rate is chosen to achieve low supply operation by exploiting high-parallelism. Fabricated in 65nm CMOS technology, two receiver prototypes are integrated in this test chip, one without and the other with front-end boot-strapped S/Hs. Including the amortized power of global clock distribution, the proposed serial link receivers consume 1.3mW and 2mW respectively at 8Gb/s input data rate, achieving a power efficiency of 0.163mW/Gb/s and 0.25mW/Gb/s. Measurement results show both receivers achieve BER < 10⁻¹² across a 20-cm FR4 PCB channel. / Graduation date: 2012
185

Long haul communications in the HF spectrum utilizing high speed modems

Ellis, Robert H. 03 1900 (has links)
Approved for public release; distribution is unlimited / In the past ten years reliable high-speed satellite systems have pushed slower less reliable communication systems to the bottom of the list for development programs. Concern over reduced budgets, vulnerability of expensive satellite systems, and recent advances in HF technology are creating new interest in upgrading existing HF communication systems. Nondevelopment Items (NDI) are defined as the use of off-the-shelf commercial items instead of costly, time-consuming conventional research and development programs. The Navy Department's current policies are designed to insure the maximum use of NDI to fulfill Navy requirements. The speed of HF systems can be improved using current signaling and modulation techniques, and reliability can be increased by error-correcting codes or error detection used in conjunction with automatic repeat request (ARQ) schemes. Improved HF systems not only provide survivable back-up capability, but increased capacity for present communication needs. / http://archive.org/details/longhaulcommunic00elli / Lieutenant, United States Navy
186

Psychologické profilování pachatele / Psychological profiling of an offender

Hroníková, Hana January 2011 (has links)
Psychological profiling of an offender Psychological profiling is a method of investigation developed in the 70's in the USA. This method is founded on research of behaviour of unknown offender with purpose to make conclusions about his personality. The purpose of my thesis is to find out how psychological profile can help during investigation. I would like to prove that psychological profiling belongs to investigation, that it can help during investigation and that it can bring a new view on case. The source of knowledge about the offender's behaviour and personality is the crime scene or text analyse. The thesis is composed of three chapters, each of them dealing with different aspects of psychological profiling. Chapter One is introductory and is subdivided into two parts. Part one describes history of psychological profiling. Part Two deals with theorethical background of psychological profiling. Chapter Two focuses on practical part of psychological profiling and consists of seven parts. This chapter explains the process of making a psychological profile, differences between mass-murder, serial-killer ad spree killer, characteristics of expert who creates a psychological profile, limits of psychological profile and differences between crimes committed by intimate people and those by unknown...
187

Behaviorální analýza a pachatelé sériových, masových a sexuálně motivovaných vražd / The behavioral analysis and serial, mass and sexual murders

Babičková, Klára January 2016 (has links)
My diploma thesis deals with the behavioural analysis and perpetrators of serial, mass and sexually motivated murders issue. The behavioural analysis is built upon bases of different methods of criminal profiles formation - psychological profiling. Following the historical outset of the criminal profile, the method of the behavioural analysis and its particular components are introduced and discussed. The components are described through optic of the most commonly used typologies, e.g. perpetrators typologies, scenes of delict, victims and murders. Hereafter I pursue issue of criminal profiling utilization in practise, particularly perpetrator profile creation, crime linking and threat assessment. The last part dedicated to the behavioural analysis consists of behavioural analysis historical development in the Czech Republic and reflection of potential future development of this issue. The second part of my diploma thesis is focused on serial murder and serial perpetrator. The definition of multiple murder and differentiation from its individual types is given. The following part comprises of introduction of the most common myths and stereotypes ingrained in the society and through statistics their creation and falseness is explained. The phenomenon of the hypothetical murderer is reached through...
188

Etude de L’endommagement en fluage de cuivre par tomographie à rayons X et polissages successifs / X-ray tomography and serial sectioning investigation of creep damage in copper

Abbasi, Kévin 04 October 2013 (has links)
Les modèles basés sur la mécanique des milieux continus prévoient généralement une déformation à la rupture plus élevée, ainsi qu'une durée de vie en fluage beaucoup plus longue que les valeurs observées expérimentalement. Cette thèse met en évidence deux aspects de cette problématique en analysant l’endommagement à l'aide de tomographie in situ à rayons X de synchrotron et reconstruction 3D de la structure polycristalline par polissages successifs.L’endommagement en termes de fraction surfacique des cavités a été identifié dans les couches de reconstructions tomographiques perpendiculairement à l’axe de déformation. L'évolution de la fraction surfacique des cavités a été comparée avec le modèle de prédiction de Cocks et Ashby. Ce dernier surestime la durée de vie en fluage et sous-estime l’état de l’endommagement. L'importance de l'hétérogénéité initiale de l’endommagement et l’effet de localisation de l’endommagement est également souligné. L'amplitude de la plus grande fluctuation surfacique augmente de façon parabolique en fonction de la fraction surfacique moyenne.Une méthode de sectionnement sériel améliorée basée sur la profilométrie de surface a été développée. Elle permet la mesure précise de l'épaisseur du matériau enlevée localement. Les analyses ont montré que l'emplacement des cavités par rapport aux joints de grains et l’orientation cristallographique des grains au voisinage est similaire pour les échantillons déformé par différents mécanismes de fluage. La population relative des cavités de fluage présente aux joints de grains simples est supérieure à celle présente aux joints triples. Les cavités trouvées aux joints triples, cependant, sont plus grandes. / Power law creep damage is one of the most intriguing unsolved phenomena of materials science. Models based on continuum mechanics generally predict a much higher strain to failure, as well as a much longer creep lifetime than experimentally observed values. This thesis highlights two aspects of this problematic by analyzing creep damage in copper using in situ synchrotron tomography and 3D reconstruction of the damaged polycrystal structure by serial sectioning.Damage in terms of the area fraction of voids was first identified in slices of tomographic reconstructions of creep deformed copper. The local and global evolution of cavities area fraction was checked against the Cocks and Ashby model and it was found that the model overestimates creep lifetime and underestimates damage development. The importance of the initial damage heterogeneity and the role of damage localization are also emphasized. It was found that the amplitude of the largest damage fluctuation increases parabolically as a function of cavity’s mean area fraction.An improved serial sectioning method based on surface profilometry was developed, which allows the accurate measurement of the removed local material thickness. The 3D reconstructions enabled identifying the creep voids and the grains of the polycrystal. It was shown that with the exception of the void shape, the relationship between void location at a given grain boundary and crystallographic orientation of the neighbor grains is similar in samples deformed by different creep mechanisms. The relative population of creep voids is higher at simple grain boundaries than at triple junctions. Voids found at a triple boundary, however, are larger.
189

A Syntactic Analysis of Motion Predicates in Southern Tati (Takestani Dialect)

Neda Taherkhani (7041479) 16 August 2019 (has links)
This dissertation provides a syntactic representation of Motion Predicates (MPs) expressed by series of verbs known as Serial Verb Constructions (SVCs) in Southern Tati –an Indo-European language spoken mainly in the Northwestern parts of Iran. This study addresses the sub-eventive decomposition of MPs by following the theoretical framework established by generative-constructivists like Borer (2005) and Ramchand (2008), as implemented for MPs in Benedicto and Salomon (2014).This dissertation also contributes to the documentation of Southern Tati, which iscategorized by UNESCO as ‘definitely’endangered.<br>
190

Dispositif d’assistance associé à des robots manipulateurs utilisés dans des procédés de fabrication/FSW / Assistance device associated to robot manipulators used in FSW process

Dardouri, Fawzia 08 November 2018 (has links)
Les robots industriels sont très utilisés aujourd’hui dans de nombreuses applications industrielles pour leur polyvalence et leur facilité programmation. Cependant, malgré leurs performances, ces robots ne sont pas adaptés à certains procédés de fabrication où des forces uniformes et élevées ainsi qu'une précision de positionnement appropriée sont requises. Le présent travail est axé sur la robotisation de l'une des opérations à forte charge, le soudage par friction-malaxage (FSW). Cette méthode d’assemblage s’utilise pour assembler des pièces en phase solide. Pour cette raison, une force de poussée très élevée est nécessaire pour ramollir le matériau pendant cette opération. En raison des forces élevées, la position de l'outil dévie de la trajectoire désirée. Dans ces travaux de thèse, la possibilité d'utiliser un dispositif d’assistance associé à un robot manipulateur est étudiée afin d’améliorer sa capacité de charge et sa rigidité. Dans une première partie, une modélisation géométrique, cinématique et dynamique ainsi que de déformation d’un robot industriel Kuka KR500-2MT est développée en localisant la flexibilité au niveau des articulations. La deuxième partie consiste à améliorer les performances de la robotisation du procédé FSW par différentes méthodes qui sont la modification du système de compensation de gravité, l’ajout d’une masse additionnelle sur l’outil, l’ajout d’une structure parallèle et l’utilisation de deux robots en mode coopératif. Les deux dernières solutions consistent à exercer des forces directement sur l’outillage. De cette façon, le mouvement de l'outil est principalement piloté par le robot industriel, tandis que le dispositif d’assistance (soit la structure parallèle ou le deuxième robot utilisé dans le système coopératif) assure la génération de forces de poussées très élevées. Des algorithmes d’optimisation ont été utilisés afin de minimiser les déviations de l’outil et donc réduire les défauts de soudage. Finalement, une étude de l’espace de travail est menée en utilisant le logiciel Catia. La connaissance de l'espace de travail pour les solutions proposées nous permet d’estimer les applications de soudage possibles ainsi que leur comparaison.. / Nowadays industrial robots are used in many manufacturing applications because of their versatility and easy applicability. Notwithstanding their performance these robots are not suitable for some manufacturing processes where uniform and high forces together with suitable precision of position are required. The present research is focused on the robotization of one of the high-thrust operations, the friction stir welding (FSW). This method for connecting two parts works while the connected materials are in the solid phase. For this reason a very high axial force is needed to soften the material during the welding process. Due to these high forces the position of the tool of a serial robot deviates from the desired trajectory. In this PhD work, the possibility of using a parallel structure device is investigated to improve the load capacity and stiffness of a heavy loadmanipulator robot. In a first part, the geometric, kinematic and dynamic modeling and the flexibility of an industrial robot, Kuka KR500-2MT are developed by locating flexibility at the joints. The second part is to improve the performance of the FSW process using an industrial robot. So different methods are examined: the modification of the gravity compensation system, the addition of an additional mass on the tool, the addition of a parallel structure and the use of a cooperative system. The last two solutions exert forces directly on the process tool. In this way the movement of the tool is mainly generated by the industrial serial robot, while the assistive device (either the parallel structure or the second robot used in the cooperatif system) ensures the generation of very high axial forces. Optimization algorithms are developed to minimize deviations and thus reduce welding defects. Finally, a study of the workspace is studied using Catia software. Knowledge of the system workspace with the proposed solutions allows to estimate the possible welding applications that can be achieved using these systems.

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