• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 1883
  • 347
  • 318
  • 250
  • 156
  • 112
  • 90
  • 73
  • 70
  • 56
  • 36
  • 34
  • 22
  • 14
  • 13
  • Tagged with
  • 4207
  • 463
  • 429
  • 332
  • 317
  • 310
  • 302
  • 279
  • 263
  • 245
  • 244
  • 244
  • 243
  • 231
  • 221
  • 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.
831

Early Channel Evolution in the Middle Permian Brushy Canyon Formation, West Texas, USA

Gunderson, Spencer 2011 August 1900 (has links)
Submarine channels are important conduits for sediment in deep marine environments, and understanding their formation is critical to modeling basin fill processes. Most models describing channel evolution focus on turbidity currents as the erosive and constructive force in channel initiation. However, slope failure and slumping can be significant drivers of channelization, particularly in upper slope and ramp environments. Determining the relative roles of slumping and erosion by turbidity currents can provide important insight into the timing of channelization and the geometries of subsequent deposits. Samples were collected from Guadalupe Mountains National Park from two primary localities at Salt Flat Bench (Figure 2). Three vertical sections were measured at both locations. A total of 16 samples were collected for petrographic analysis and X-ray fluorescence (XRF) imaging. Spectacular outcrop quality makes the Middle Permian Brushy Canyon Formation in Guadalupe Mountains National Park an ideal location for the study of early channel evolution. A detailed facies analysis of fine-grained channel deposits was conducted in the Upper Brushy Canyon Formation in the Salt Flat Bench outcrops. After channelization, an interval of relative condensation dominated by hemipelagic settling of organic matter and silt was followed by an interval of incomplete sediment bypass by turbidity currents. This sequence of events suggests that sea level was at a relative highstand at the time of channel inception, whereas channel inception by turbidity currents is expected during a lowstand. Slumping rather than erosion by turbidity currents is the most likely mechanism to have initiated a channel at the study area. There is no evidence for the existence for high energy currents until after the interval of condensation. However, the action of weak contour currents during early channel evolution is observed in outcrop and microtextural features. Early carbonate cementation of channel-lining silts may have stabilized the slump surface with respect to erosion by later turbidity currents.
832

Optimal Distributed Beamforming for MISO Interference Channels

Qiu, Jiaming 2011 May 1900 (has links)
In this thesis, the problem of quantifying the Pareto optimal boundary of the achievable rate region is considered over multiple-input single-output(MISO)interference channels, where the problem boils down to solving a sequence of convex feasibility problems after certain transformations. The feasibility problem is solved by two new distributed optimal beam forming algorithms, where the first one is to parallelize the computation based on the method of alternating projections, and the second one is to localize the computation based on the method of cyclic projections. Convergence proofs are established for both algorithms.
833

Implementation of Turbo Code Decoder IP Builder

Ko, Meng-chang 08 July 2004 (has links)
Turbo Code, due to its excellent error correction capability, has been widely used in many modern wireless digital communication systems as well as data storage systems in recent years. However, because the decoding of the Turbo Code involves finding all the state probability and transition sequence, its hardware implementation is not straightforward as it requires a lot of memory and memory operation. In this thesis, a design of Turbo Code decoder IP (Intellectual Property) is proposed which can be parameterized with different word-lengths and code rates. The design of the core SISO (Soft-In Soft-Out) unit used in Turbo Code decoder is based on the algorithm of SOVA (Soft-Output Viterbi Algorithm). Based on the hybrid trace-back scheme, the SISO proposed in this thesis can achieve fast path searching and path memory reduction which can be up to 70% compared with the traditional trace-back approach. In addition, every iterative of Turbo Code decoding performs two SISO operations on the block of data with normal and interleaving order. In our proposed architecture, these two SISO operations can be implemented on a single SISO unit with only slightly control overhead. In order to improve the bit error rate performance, the threshold and normalization techniques are applied to our design. In addition, the termination criteria circuit is also included in our design such that the iteration cycle of the decoding can be reduced. The proposed Turbo Code decoder has been thoroughly tested and verified, and can be qualified as a robust IP.
834

Mechanical Properties in 6061 Aluminum Processed by Equal Channel Angular Extrusion

Tsai, Meng-shan 14 July 2004 (has links)
none
835

A Feasibility Study of eggs home delivery in Taiwan---in marketing perspective

Feng, Chao-chun 10 August 2005 (has links)
Most of the patterns of distribution channel of eggs traditional industry are through the middlemen. Therefore the distribution channel classifies multiple-steps distribution channel system. The price relationship between producers and sales works out by the middlemen for a long time and consequently cause many different viewpoints and conflicts about the price decision. In spite of the middlemen realize and tacitly agree the system of price establishment is not reasonable. They still can not change the actuality because it goes all the year round. Up to now, the producers and sales can not create a win-win situation. The change of marketing channels will reform structures of the production, sales and price forms. Therefore this study takes the home delivery as main body for the eggs marketing channels research, and adopts in-depth interview method to get data and information. At the same time this study penetrates the marketing strategy of egg industry , the business developments and characteristics of home deliveries. This study proceeds to interview the above information as SWOT analysis. To find out the feasibility of eggs home delivery and the point of strategy and problems. Finally, this study would offer some solution aspects and suggestions. The results showed that from the viewpoint of return, the possible pattern of eggs home delivery could create producers much mighty possibilities and big changes by a series of ways to make difference. It means that this study adopts the niche market to be the strategy of market segment and finds the target market and proper marketing mix, the package variation, functional egg developments, confidence-building with home deliveries and regulated contract of products quality. So that producers could develop the private channels and private label brand to change the price-decision system to reach the sustainable development.
836

Design and Implementation of a Low-cost DVB Channel Decoder

Wang, Jhih-Jian 06 September 2005 (has links)
In this thesis, a highly efficient implementation of the channel decoder for terrestrial digital video broadcast (DVBT) standard is proposed. DVB-T channel decoder is mainly composed of four major modules including the inner Viterbi decoder, outer Reed-Solomon decoder and inner and outer de-interleaver modules which all require significant amount of intermediate data storage. The main contribution of this thesis is to propose suitable architectural solution for each individual module to achieve efficient realization of the data storage mostly by single-port memory blocks which can lead to the reduction of silicon area and the dynamic power dissipation. For the outer convolutional deinterleaver module, a special address generator has been proposed such that the data deinterleaver path can be merged and implemented as three memory blocks. For the inner symbol deinterleaver module, a lookahead technique has been applied to the design of address generator that can generate valid deinterleaving address each cycle to avoid the buffering problem. In addition, a novel deinterleaver memory partitioning architecture is proposed such that the entire deinterleaver can be built on four single-port memory banks. These four modules have been verified and integrated as a robust channel decoder silicon intellectual property (IP). Our implementation result shows that the core area of entire DVB-T channel decoder IP (Intellectual Property) can be realized in less than 6.8 mm2 in 0.18-µm TSMC technology.
837

Corporate reputation¡BRecruit channel¡BRecruit effectiveness and Organizational attractiveness research of relation-High tech industry

Ko, Chin-Jung 07 February 2006 (has links)
Under the wave of globalization and liberalization, all enterprises face vigorous competition. The enterprises must adjust their resources and strategy to survive. Human resource is the most valuable and prominent property to a company.The recruit is the foundation of all the Human ResourceManagement. Quality Human Resource can increase the total benefits of the enterprise. And corporate reputation is recognized as a critical factor of competitive advantage for firms in the labor market.The recruiting effective in the process is very important. The purpose of this study was to examine the possible impact of the corporate reputation¡Brecruiting channel¡Brecruiting effective and view on organizational attractiveness. Therefore, this research bases on the survey of the High Tech Company in Taiwan.By statistic analysis method get some findings as follows: 1.Corporate reputation, Recruit channel are significant affect to Recruit effectiveness. 2.Corporate reputation, Recruit channel are significant affect to Organizational attractiveness. 3.Corporate reputation, Recruit channel, Recruit effectiveness, Organizational attractiveness are significant affect to different character of Corporate.
838

A Low-Voltage Low-Power Widely Tunable Channel Select Filter

Huang, Ding-jhih 06 July 2006 (has links)
In this thesis, we propose a low voltage low power wide-tuning 4th-order butterworth low-pass OTA-C channel selection filter. It is implemented by using TSMC 0.35£gm 2P4M CMOS technology. The drain voltage of triode-biased input transistors of the OTA is regulated through an active-cascode loop for low power and wide-tuning range. The Gm-C channel selection filter can be programmed from 0.5 to 12MHz. The OTA also employs a circuit to reduce the OTA output current in a high transconductance mode and the total power consumption of filter is suppressed below 3mW.
839

3-Dimensional Numerical Stress Analysis around a Micro-Channel Wall Crack Tip in a Micro-PEMFC

Huang, Yen-lung 21 July 2007 (has links)
The main aim of this study is to develop three dimensional models for micro flow-field plate of PEMFC and use numerical simulations to discuss the reliability of micro flow-field plate which works in real. A crack exists in the plate is loaded by the shear force, which is produced by the fuel H2 enter from inlet, and will propagate. The Ag, which is used to collect the electrons, will peel off and the efficiency of fuel cell will decrease. The commercial package software ANSYS was used to simulate the stress state around crack tip. Three modes of stress intensity factors K£L, K£L£L and K£L£L£L, were calculated in order to describe the stressed behavior of crack. Finally, the inlet pressure, geometry of crack and channel size is changed and Taguchi method with ANOVA is used to find the factors which influence the stressed behavior of crack most. The simulation results show that K£L and K£L£L are influenced most by geometry of crack and K£L£L£L is influenced more by geometry of crack and channel size
840

THREE TYPES OF VOLTAGE-DEPENDENT CALCIUM CURRENTS IN CULTURED HUMAN NEUROBLASTOMA CELLS

WATANABE, KAZUYOSHI, MAEHARA, MITSUO, KITO, MASAO 27 May 1995 (has links)
No description available.

Page generated in 0.0556 seconds