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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.
21

Managing projects with strong technological rupture case of high-speed ground transportation systems /

Tilière, Guillaume de. January 2002 (has links)
Thesis (Civil Engineering)--École polytechnique fédérale de Lausanne, 2002. / PDF document ; contains 333 pages, with illustrations and charts (some col.). "Thèse no. 2568 (2002)." Includes bibliographical references.
22

The design of efficient radial turbines for low power applications

Atkinson, M. J. January 1998 (has links)
No description available.
23

Contouring control in high performance motion systems /

Chen, Ni. January 2005 (has links)
Thesis (M.Phil.)--Hong Kong University of Science and Technology, 2005. / Includes bibliographical references (leaves 81-86). Also available in electronic version.
24

On high speed machining of titanium alloys : analysis and validation

Sonnekus, Reino 30 August 2010 (has links)
M.Ing. / This report documents the steps taken to gain insight into the phenomena of high speed machining (HSM) of titanium alloys. This was done by firstly studying titanium alloys and the problems associated with machining titanium alloys. An experimental set-up and procedure was developed for measuring and recording both the machining temperature and component forces. A sufficient set of experimental data was collected through extensive experimentation. The cutting temperatures and component forces in HSM of Ti-6Al-4V were examined simultaneously. The cutting speed was found to be the most influential and limiting parameter on the machining temperature and component forces. A new approach for modeling the temperatures in HSM of titanium alloys was developed. Analytical predictions of the cutting temperatures were performed and used to evaluate the influence of a variation in the process parameters on the cutting temperature. The research provides insight for future work into the phenomena of HSM of titanium alloys . The results of the analytical model were found to be representative and comparable to the experimental data. It is however expected that the deviation between the predicted and measured result may be significantly reduced by changing the experimental approach. It is recommended that a complete set of experiments be done, using a new tool insert for every cut, thus removing the effect of possible tool wear on the experimental data obtained. In addition it is recommended that the iterative solution be improved through more in depth programming, considering the change in both the thermal and mechanical materials properties with a change in temperature. Ultimately the assumptions made in order to simplify the problem addressed in this report needs to be improved upon, in order to analyze data trends and even magnitudes to a greater degree of certainty.
25

Diesel spray characteristics, spray/wall interaction and heat transfer

Cutter, Paul January 1996 (has links)
No description available.
26

Airport and station accessibility as a determinant of mode choice /

Clever, Reinhard. January 1900 (has links)
Thesis (Ph. D. in Civil Engineering)--University of California, Berkeley, 2006. / Cover title. "Fall 2006." Includes bibliographical references (leaves 292-300). Also available online.
27

Range-Video Network (RNET)

Berard, Alfredo, Buckley, Mark, Roach, John 10 1900 (has links)
ITC/USA 2010 Conference Proceedings / The Forty-Sixth Annual International Telemetering Conference and Technical Exhibition / October 25-28, 2010 / Town and Country Resort & Convention Center, San Diego, California / The deployment of network-based airborne instrumentation systems is leading to cost-efficient replacement of legacy instrumentation systems. One application of airborne data acquisition that has been developed and maintained separately from traditional avionics and orange-wire data acquisition systems is high-speed camera packages. The development of network-based instrumentation systems has led to an opportunity to unify these two previously distinct airborne data acquisition activities. This paper describes the range-video network-based instrumentation system (rNET) being implemented by the 46th Test Wing, 846th Test Support Squadron at Eglin Air Force Base, FL to replace the existing Airborne Separation Video System (ASVS).
28

Design automation of Reed-Solomon codecs using VHDL

Smith, Simon January 1999 (has links)
Reed-Solomon (RS) codes are non-binary, forward error-correcting codes. The RS code is flexible, in that a code can be shortened, extended, interleaved and concatenated. This flexibility has made the RS code an important design block in communication system design and today the RS code is used within a large number of applications from data storage systems to space telecommunications. Implementations of the coding and decoding strategies have until recently been limited to software due to their high complexity, however, with recent advances in IC fabrication technology it has become possible for RS codecs to be implemented in hardware. A hardware implementation has a smaller silicon requirement, and makes the technology a more applicable solution for real-time applications. However, the problem for a hardware RS codec design solution today is the acknowledged lack of codec design experts. The work outlined in this document addresses this problem through the use of Design Automation (DA). This thesis describes a solution that employs a non-proprietary, technology independent generic VHDL core. The core is a single, self-contained generic circuit description, written entirely in standard synthesizable VHDL and can therefore be used by any synthesis tool on any CAD system to produce a gate-level description for any available technology. The core developed implements a bit-serial RS codec, using a time domain algorithm for encoding, and a frequency domain algorithm for decoding. Only a limited number of code description parameters are required to be entered into the core to produce a completed design in seconds. The results presented in the thesis illustrate in detail that the VHDL core generates efficient circuit architecture in terms of silicon area which are within I% of hand-crafted designs. Comparison of synthesized results to hand crafted designs are presented for all circuit structures from the simplest multiplier up to entire encoders and decoders. Technology independence has been illustrated through the use of synthesis of the core to a traditional semi-custom gate array, LSI Logic LCA300k series, and to a popular Xilinx FPGA. The actual circuit topology, and therefore the route of the circuit critical paths, for the gate array implementation are almost identical to the handcrafted design., since the VHDL core was based on experience gained in creating those circuits. The only differences are attributable to minor differences in synthesis cell libraries that affect the circuit topology in a small way and of course the resulting maximum clock rate which wi11 always be technology-dependent. Obviously, for other architectures, for example FPGAs, the actual route of the critical paths will also be different, but the technology dependence of the critical path is beyond the scope of this thesis.
29

Delay Sensitive Routing for High Speed Packet-switching Networks / 高速封包交換網路中考量網路延遲的路由

黃玉昇, Yu-Sheng Huang Unknown Date (has links)
在如同全IP網路(ALL-IP Network)這類的分封交換網路(packet-switching network)中提供具時效性的服務(time-sensitive services)必須嚴格的控制時間。路由規劃是網路管理中重要的一環,所以這類網路的路由規劃必須考慮網路延遲。然而就我們目前所知,多數的傳統路由演算法並不以傳輸延遲(path delay)為主要考量因素;例外少數有考量延遲時間的演算法也僅限於鍊結延遲(link delay),而未考慮節點延遲(node delay)。此乃肇因於以往頻寬的成本極為昂貴,因而造成演算法設計者在設計時會儘可能有效利用頻寬,如此免不了會犧牲傳遞速度。在過去幾年間,由於光通訊技術的提升,網路頻寬的成長速度遠遠已超過路由器(router)處理能力的成長。在這樣不對等的成長比例驅使下,節點延遲,亦即路由器處理封包時所耗時間,在傳輸延遲中所佔的比例亦隨之快速增長。也因此我們認為,在為高速封包交換網路設計路由演算法時,必須同時考量鍊結延遲和節點延遲。在本論文中,我們設計了一個訊務流為基礎的路由演算法(flow-based routing algorithm),KLONE,來驗證我們的論點。在規劃路由時,KLONE會把發生在鍊結和節點上的延遲時間一併列入計算,並以全體延遲時間為主要考量。透過我們反覆的測試實驗,我們發現其較之於常用的OSPF演算法,可以在效能上有30%的勝出。藉此,我們的論點得到初步的證實。 / Providing time sensitive services becomes an essential task for some packet-switching networks such as All-IP networks, which will carry all the traffics supported by both circuit-switching and packet-switching networks. To fulfill this demand, such networks require a delay sensitive routing mechanism to provide time-related QoS for delay sensitive services. However, most of traditional routing algorithms do not take delay time as a major concern. Only a few are designed for time sensitive services. These time sensitive routing algorithms are designed at the time when the link bandwidth is the only scarce resource. As the bandwidth of communication links grows rapidly in recent years due to the advance of optical communication technologies, link bandwidth is no longer the only scarce resource. The processing speed of nodes, for example, routers, becomes another critical source of delay time. In this thesis, we designed a new flow-based routing algorithm, the KLONE algorithm, which takes average delay time as its minimization objective and takes both nodes and links as delay components. Through an intensive evaluation using simulation method, we demonstrate that a routing algorithm that considers both link and node delay might outperform the traditional OSPF algorithm.
30

Studies of hydrogen-air turbulent diffusion flames for subsonic and supersonic flows

Zheng, Li Li January 1993 (has links)
No description available.

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