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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.
271

Evaluation of organizational self-assessment tools and methodologies to measure continuous process improvement for the Naval Aviation Enterprise

Kaehler. Theodore J. 09 1900 (has links)
The Naval Aviation Enterprise (NAE) has created a program called AIRSpeed to deliver the efficiency gains of continuous process improvement (CPI). NAE leadership seeks a self-assessment tool to measure how well AIRSpeed has been implemented, including possible areas for improvement. This thesis studies the origins of continuous process improvement, the value of assessment, and current assessment methodologies. Key concepts are cited for the use of organizational assessment tools. The objectives are an enhanced body of knowledge for enterprise assessment, to provide a comparison of several approaches, and to recommend a tool for NAE AIRSpeed. The tools to be considered are the Department of Defense CPI Transformation Guidebook (DoD CPITG), the Navy's Performance Excellence Guidebook (NPEG), the Lean Aerospace Initiative (LAI) Government Lean Enterprise Self-Assessment Tool (GLESAT), and the NAVAIR Alignment Assessment Tool (NAAT). Research revealed that three of the four tools (DoD CPITG, NPEG, and GLESAT) could efficiently measure AIRSpeed maturity, and recommendations were made that a performance management framework be established by the NAE prior to implementation of any formal assessment process. The maturity level of NAE AIRSpeed could be baselined using the LAI tool in those areas where lean principles have been implemented over a period of years.
272

The estimation of large scale complex system reliability

Metler, William A., Metler, William A. January 1980 (has links)
No description available.
273

Test and evaluation in the United States Navy, and how it must evolve to support future systems acquisition

Bodmer, Gerald A. 09 1900 (has links)
Approved for public release; distribution is unlimited. / Modern Test and Evaluation has long supported acquisition of warfighting systems in the United States Navy. As the complexity and long-term supportability of these systems has dramatically increased, the need to successfully, and incrementally test and evaluate families of systems, including their interfaces, has become even more critical. Long established techniques and methodologies for T&E may still apply, but new factors must be addressed. As the Navy continues to grapple with acquisition reform, and also looks to transform itself in the future, the Warfighters’ needs have essentially remained the same – delivery of the best, most effective weapons, delivered as soon as possible, and made easy to operate and maintain. Without an equally effective developmental and operational test and evaluation process, the United States Navy cannot satisfy this need. This thesis examines T&E today and where it must go in the future. It provides recommendations for T&E enhancements, and explores several areas where the Navy, and in many cases, Joint Services, are already looking towards future, integrated and collaborative test and evaluation. / Civilian, Naval Surface Warfare Center, Corona Division, United States Navy
274

A Systems Approach to Compliance with Australian Airworthiness Regulations for Uninhabited Aircraft Systems.

Schnellbeck, Anthony, anthony.schnellbeck@baesystems.com January 2006 (has links)
A considerable amount of research effort has, and continues to be invested into technologies and algorithms for capabilities which are forecast to be needed in future uninhabited vehicles. Much of this research is conducted with the aim of increasing the level of autonomy of these vehicles. However these technologies and capabilities provide only a part of the total system solution and must be integrated into an architecture that covers the entire vehicle system. This total system approach is particularly relevant since this is how airworthiness regulators consider Uninhabited Aircraft Systems. Airworthiness of uninhabited aircraft has been addressed by Australian aviation regulators. While the regulations may be in place, technical challenges still remain for the suppliers of these systems. For example, one of these unresolved technical challenges is the capability of uninhabited aircraft to
275

Two-Tone PLL  for On-Chip Test In 90nm-Technology

Shuaib, Muhammad January 2009 (has links)
<p>In this report the two-tone PLL circuit intended for on-chip test of RF blocks is presented. The primary application is the third order intermodulation test (TOI), vital for RF front-ends. If the spectral analysis can also be completed by DSP available on the chip or on board, it provides a built in self-test (BiST) which can replace costly test instrumentation (ATE). The advantage of the designed two-tone PLL is that it practically prevents the locking effect while keeping the two oscillation frequencies close. Also by careful design the possible intermodulation distortion of the two-tone stimulus can be avoided.</p><p>The two-tone PLL has been designed and verified at the system level using Verilog-A models in Cadence <sup>TM. </sup>Besides, two building blocks of the PLL were implemented at the circuit level in 90nm CMOS technology. The obtained results are promising in terms of a practical two-tone BiST implementation.</p>
276

Identification of a physically idealized human rated rocket based interplanetary transportation system /

Ewig, Ralph. January 2006 (has links)
Thesis (Ph. D.)--University of Washington, 2006. / Vita. Includes bibliographical references (leaves 168-172).
277

Joint Optimization of Process Improvement Investments for Supplier-Buyer Cooperative Commerce

Comeaux, Erick 12 January 2004 (has links)
This research focuses on supporting the formation of strategic alliances through the concept of cooperative commerce, where suppliers and buyers work together to jointly optimize their businesses. The general goal of this research is to examine existing cooperative commerce models for obstacles that would hinder their successful implementation into modern industrial applications and to address those shortcomings. Total annual cost equations are formulated to capture the joint total relevant cost of cooperative commerce business relationships. These total joint relevant cost models will include terms that capture the ordering cost, holding cost, and cost of quality, as well as any applicable investment cost for process improvements, consistent with traditional economic order quantity and economic production quantity theory. This research corrects a modeling error of Affisco, et al. (2002) that led to underestimating the effectiveness of process improvements in joint economic lot size models. In addition, the models are expanded to accommodate a full range of product quality inspection policies, from zero to one hundred percent product inspections. Furthermore, the models are modified to account for the cost of scrap generation, as well as the effects of accepting non-conforming product and rejecting conforming product during quality inspections. Once the total cost models are expanded to account for these neglected costs, the joint total relevant cost equations are minimized to find the optimal batch sizes, and the effects of each model extension on the model solution are studied. Results indicate that these extensions do have a significant impact on the model results, such as reduced optimal batch sizes and increased optimal fraction conforming product.
278

Performance Assessment of Coated Cemented Carbide Tools in Turning AISI 1018 Steel

Nouilati, Mohamad 14 April 2004 (has links)
In this study, the machining performance of a series of commercially available coated tungsten based cemented carbides, with 55o diamond shape, were investigated during finish turning of AISI 1018 steel under dry conditions. The inserts tested had a coating of TiN, Al2O3, TiN/Al2O3 and TiC/Al2O3/TiN respectively. For comparison, uncoated cemented tungsten carbide was also tested under the same cutting conditions. The coated tools exhibited superior wear resistance over the uncoated tool. The TiC/Al2O3/TiN coated tool had the lowest flank wear due to the high abrasive resistance of the TiC layer. The Al2O3 coated tool showed superior wear-resistance over the TiN/Al2O3 coated tool due to the TiN coating that deteriorated the effect of the Al2O3 outer layer. The TiN coated tool showed the least wear resistance with respect to the other coated tools. Surface roughness appeared to increase with flank wear while oscillating for all the tested tools except for the TiN coated tool. The TiN coated tool produced a relatively consistent surface roughness that was not significantly affected by the flank wear under the conditions tested. The coated tools produced lower surface roughness compared to the uncoated tool, except for the TiN/Al2O3 coated tool, which produced considerably higher surface roughness. The reason for this however was the geometry of the chip breaker, rather than the coating materials, which produced longer chips that came in contact with the work piece during the machining process. The TiC/Al2O3/TiN coated tool produced the lowest surface roughness of all the tools tested.
279

Route Planning of Automated Guided Vehicles for Container Logistics

Gurav, Sanjay Shankarrao 15 April 2004 (has links)
Automated guided vehicles (AGVs) are widely used in container terminals for the movement of material from shipping to the yard area and vice versa. Research in this area is directed toward the development of a path layout design and routing algorithms for container movement. The problem is to design a path layout and a routing algorithm that will route the AGVs along the bi-directional path so that the distance traveled will be minimized. This thesis presents a bi-directional path flow layout and a routing algorithm that guarantee conflict-free, shortest time routes for AGVs. Based on the path layout, a routing algorithm and sufficient, but necessary conditions, mathematical relationships are developed among certain key parameters of vehicle and path. A high degree of concurrency is achieved in the vehicle movement. The routing efficiency is analyzed in terms of the distance traveled and the time required for AGVs to complete all pickup and drop-off jobs. Numerical results are presented to compare performance of the proposed model. The research provides the foundation for a bi-directional path layout design and routing algorithms that will aid the designer to develop complicated path layouts.
280

Effects of Automobile Seating Posture on Trunk Muscle Activity

Saidu, Milton Maada-Gormoh 16 April 2004 (has links)
Reports for adult population indicate that almost 80% of the adult population has reported some form of lower back aches. Each year American workers suffer more than 300,000 lost-time injuries involving musculoskeletal disorders of the back, with the costs that run into billions of dollars. Sedentary tasks are known to be major contributing factors of back pain. Prior studies have indicated that the myoelectric activity of the lumbar region decreases when the back rest inclination of a seat increased. An increase in seat pan inclination so that it increases pressure on the leg muscles is also a cause for back pain. Seating posture is also known to be a leading cause of back pain. This study focuses on the response of the latissimus dorsi muscle in the trunk, to the backrest and seat angle inclinations for different seating postures. Twenty one participants took part in the backrest experiment. The automobile seat backrest angle was varied for two angles of 90 and 100 degrees in a one hour driving session. Ten participants took part in the seat angle experiment; the seat was set at 0 and 10 degrees for a 30 minutes session at each angle. The muscle activity of the latissimus dorsi was recorded for seating postures at each angle. Based on the electromyography data, the results of analyses of variance for mean of root mean square values for the backrest experiment (P < 0.05) showed significant change. In seat angle experiment the analysis of variation of the mean values for root mean square values at (P < 0.05) was significant. It is concluded that increased backrest and inclined seat angle decreases muscle activity in the latissimus dorsi muscle.

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