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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.
151

Switch mode emulation of large value capacitors in the rotor circuit to improve the induction motor performance

Suciu, Constantin January 2000 (has links)
No description available.
152

The development of a database of rock properties to assist in the design and development of crushing plant

Jackson, Keith January 1999 (has links)
No description available.
153

The growth, structure and properties of sinter-necks in mixed ferrous powder systems

Rhodes, Nigel Anthony January 1998 (has links)
No description available.
154

Snabba Vändningar : En utvärdering av frekvensstegar som träningsredskap för fotbollsspelare

Lindé, Gabriel January 2012 (has links)
Syfte och frågeställningar Syftet var att undersöka frekvensstegen som träningsmetod för fotbollsspelare i avsikt att öka snabbhet i vändningar och agility då dessa förmågor är mycket viktiga för en spelare under en fotbollsmatch. Frågeställningar: Ökar träning med frekvensstege spelarnas agility? Förbättrar träning med frekvensstege spelarnas förmåga att ändra riktning i hög hastighet? Metod För att besvara frågeställningarna valdes en experimentell, kvantitativ studie med Test-Retest som insamlingsmetod. I studien deltog både en försöksgrupp och en kontrollgrupp. Försöksgruppen var ett damfotbollslag, ålder 18.8±1.9  år och de var 12 deltagare. Kontrollgruppen var ett damfotbollslag, ålder 17.8±0.8 och var 6 deltagare. Undersökningen pågick under 7 veckor och vid totalt 12 tillfällen. Spelarna undersöktes två gånger i T-drill, Pro Shuttle och Z-drill. Vecka 1 var förtesterna (Test). Vecka 2-6 pågick träningen med frekvensstegar, två tillfällen per vecka och 30 minuter per tillfälle (totalt 9 tillfällen och 4,5 timmars träning). Vecka 7 utfördes det andra testtillfället (Retest). Resultat Ingen skillnad fanns mellan grupperna gällande varken agility eller vändnignar i hög hastighet. Gällande agility så förbättrades båda grupperna i Pro Shuttle (-0,234 ±0,194 sek) samt försämrades i Z-drill (0,518±0,393 sek), p<0,000. Båda grupperna förbättrades även i T-drill (-0,49±0,448 sek), p<0.000.  En analys med ANOVA RM visar att grupperna inte skiljdes åt gällande förändring i agility eller vädningar (p<0,451-0,972). Slutsats Studien pekar på att frekvensstegen leder inte till några signifikanta ökningar i agility men tyder också på att de inte hämmar utvecklingen. Därmed kan stegarna vara en del av ett träningsprogram för fotbollsspelare för att eventuellt förbättra andra områden av prestation. / Aim The aim is to evaluate agility ladders as a method for soccer players to increase change of direction-skill and agility, as these skills are very important for a player during a game. Specific aims: Will agility ladder training increase the players’ agility? Will training with agility ladders improve the players’ ability to change direction at high speed? Method An experimental and quantitative study model was chosen, collecting results through Test-Retest measurements. A trial group and a control group took part in the study. The trial group consisted of a women’s soccer team, age 18.8±1.9, with 12 participants. The control group consisted of a women’s soccer team, age 17.8±0.8, with 6 participants. The study lasted 7 weeks and on 12 occasions. The players were tested twice in the T-drill, Pro Shuttle and Z-drill.  In week 1 the first tests were conducted. Through the following five weeks the training took place, thirty minutes - two times a week (a total of 9 workouts and 4,5 hours of training). The final tests were conducted during the seventh week. Results   No difference was found between the groups in the T-drill (change of direction), Z-drill or Pro Shuttle (agility). Both groups improved in the T-drill (-0.49 ± 0.448 sec) and the Pro Shuttle (-0.234 ± 0.194 sec) and deteriorated in the Z-drill (0.518 ± 0.393 sec), p <0.000. Analysis of the results, using ANOVA RM, shows that the groups do not differ regarding change in agility (p<0,451-0,972).   Conclusions   The study indicates that the agility ladders do not produce significant increases in agility, but also suggest that they do not hamper development. This allows agility ladders to be part of a training program for soccer players to possibly improve other areas of performance.
155

HARMONIC INVESTIGATION IN LOW AND MEDIUM VOLTAGE NETWORKS USING COMPUTER SIMULATION AND MEASUREMENT DEVICES

Egner, Sean Robert William 31 October 2006 (has links)
Student Number : 9811492X - MSc dissertation - School of Electrical and Information Engineering - Faculty of Engineering and the Built Environment / This dissertation discusses the development of an ATP model of a network to aid measurement techniques in a harmonic evaluation. A theoretical back- ground discussion of various pieces of equipment and their signi#12;cance to har- monics is included. National Electricity Regulator (NRS 048) standards are discussed with refer- ence to performing a basic investigation and short comings. A test study was performed on the Brandspruit Mine in Secunda. ATP models are developed for equipment relevant to the test case, these in- clude AC{AC converters, AC{DC converters, three phase transformers and cables. Finally the measured test case is compared to simulation results and conclusions drawn.
156

The feasibility of sodar wind profile measurements from an oceanographic buoy

Berg, Allison M. 09 1900 (has links)
This thesis explores the feasibility of making wind speed profile measurements from an oceanographic buoy using a Doppler sodar. In the fall of 2005, we deployed a Scintec SFAS sodar on an ASIS buoy. Roughly one week of buoy motion data and one day of sodar observations were collected. Data from both this deployment, and the Martha's Vineyard Coastal Observatory, were used in conjunction with models to predict sodar performance. Results are compared for an ASIS and a 3-meter discus buoy. We also predict the yearly average probability of sodar data availability in the presence of buoy motion. We show that buoy tilting in response to wave forcing is the main factor affecting sodar performance. Our results strongly suggest that ASIS is a suitable platform for sodar measurements at sea. / US Navy (USN) author.
157

Infinite impulse response notch filter

Jangsri, Venus 12 1900 (has links)
Approved for public release; distribution is unlimited / A pipeline technique by Loomis and Sinha has been applied to the design of recursive digital filters. Recursive digital filters operating at hitherto impossibly high rates can be designed by this technique. An alternate technique by R. Gnanasekaran allows high speed implementation using the state-space structure directly. High throughput is also achieved by use of pipelined multiply-add modules. The actual hardware complexity will depend upon the number of pipeline stages. These techniques are used for the design of the I IR notch filter and finally, a comparison of the performance and complexity of these two techniques is presented. / http://archive.org/details/infiniteimpulser00jang / Lieutenant, Royal Thai Navy
158

The Effect of an Eight-Week Training Program upon Leg Strength and Running Speed in Middle-School-Age Boys

Leach, Edward L. 08 1900 (has links)
The purpose of this study was to determine the effects of an eight-week weight training program upon leg strength and running speed of middle-school-age boys.
159

Techniques et méthodologies de validation par la simulation des liens multi-gigahertz des cartes électroniques haute densité / Technologies and methodologies of the high-speed serial links validation on high density interconnect circuit using simulation

Chastang, Cyril 18 March 2013 (has links)
La tendance dans la conception de cartes électroniques imprimées est de remplacer les traditionnels bus parallèles par des liens série rapides dont le débit peut atteindre plusieurs dizaines de Gigabit par seconde (Gbps). Cette thèse proposée par THALES Communications & Security en collaboration avec le laboratoire SATIE de l'ENS de Cachan a pour objectif de définir une approche adaptée au traitement des problèmes de liens multi-gigahertz, de manière à garantir le fonctionnement d’une carte numérique complexe (multicouches, haute densité d'intégration, ...) sans qu’une phase de prototypage ne soit nécessaire. Après un état de l’art, ce travail s’est organisé en trois parties : La première partie porte sur l'étude du canal de propagation. La décomposition spectrale des liens multi-gigabits couvrant plusieurs gigahertz voir plusieurs dizaines de gigahertz montre la nécessité d'employer des logiciels de simulations spécifiques au domaine des hyperfréquences. Une évaluation de certains solveurs électromagnétiques 3D parmi les plus récents a été réalisée afin d'extraire les paramètres S du canal de propagation de façon précise et rapide a partir des informations issues des logiciels de CAO utilisés à THALES. La seconde partie traite de la prise en compte des émetteurs, des récepteurs et des traitements numériques associés dans la simulation afin de réaliser des calculs de diagrammes de l'œil, de taux d’erreurs binaires (BER) et de jitter. L’utilisation de la norme IBIS-AMI, très récente, et la comparaison des performances aves d’autres outils, tel que HSPICE, a demandé l'évaluation de simulateurs circuit de dernière génération. Cette étape a été réalisée en étroite collaboration avec les éditeurs des logiciels car certains outils ne sont pas suffisamment matures pour s'inscrire dans un flot global de conception. Enfin, la chaîne de simulation complète ayant été validée par la mesure, nous avons effectué une analyse approfondie des différentes composantes du jitter en fonction des phénomènes physiques plus ou moins destructeurs pour la qualité du signal. Cela nous a ensuite permis d’établir les règles et la méthodologie de conception, en tenant compte des marges allouées à partir des résultats de l’analyse du jitter. / The designers of Printed Circuit Board (named “board” below) tend to use more and more multi-gigabit serial links rather than traditional parallel buses. It enables to push back the density limitations and to increase embedded functionalities of the board. This thesis is the result of collaboration with THALES Communications & Security and the SATIE laboratory of ENS Cachan. The goal of the thesis was to define an approach dedicated to the study of Multi-GigaHertz (MGH) signals in order to assure that digital complex boards work without costly multiple prototype designs. After an inventory of the state of the arts, this work was conducted in three parts: The firt part relates to the study of the propagation channel. The spectral power distribution of the multi-gigabit links ranges from DC to several dozens of gigahertz, it is the reason why specific simulation softwares usually used in the hyper-frequency field have to be used A benchmark of several most recent 3D ElectroMagnetic (EM) solvers has been achieved in order to quickly and accurately extract the S Parameter matrix of the propagation channel thanks to information from CAO softwares used in THALES The second part consisted to take into account the transmitters, the receivers and the digital treatments associated in the circuit simulation in order to calculate eye diagrams, Bit Error Rate (BER) and Jitter separation. The benchmark of the latest generation of channel simulators was needed for the use of the recent norm IBIS-AMI and the comparison of the performances with other tools, such as HSPICE. This step has been led in close collaboration with the simulation software suppliers because some tools are not mature enough to fit into a global design flow. Finally, thanks to the validation of the simulation flow with measurements, a deep sudy of the different components of the jitter has been conducted depending on the physical phenomenon being more or less destructive for the quality of the transmission. This study enabled to define design rules and design methodology taking into account the margins allocated from the results of the jitter analysis.
160

Rychlobruslařská aréna a postoj veřejnosti k její výstavbě / Speed skating arena and public attitude to its construction

Ruda, Tomáš January 2011 (has links)
Title: Speed Skating arena and public attitude to its construction Objectives: The main aim of the diploma thesis is the analysis of a project of a speed-skating rink in Velky Osek. Citizens from Kolin and Nymburk regions, as well as Prague, have been polled on the possible rink construction. Citizens have been surveyed on their foreknowledge and the future possibility of the of grounds usage. Methods: A descriptive analysis was used to comment on data gathered in relationship to the proposed construction of a speed-skating rink. Furthermore, a SWOT analysis was used in order to evaluate the direct external and internal impact the proposed construction of a speed-skating rink in Velky Osek (Kolin region). A quantitative survey (questionnaire) has been used in polling citizens on their attitude toward the possible construction of the rink. Results: The results have shown the heterogeneity of the attitudes of the citizens. However, we may conclude that there are more people who support the idea ofconstructing a speed-skating rink in the Czech Republic, rather than the proposed construction project in Velky Osek. Keywords: Speed Skating, Arena, Public

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