• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 542
  • 166
  • 107
  • 75
  • 55
  • 20
  • 18
  • 16
  • 13
  • 10
  • 9
  • 7
  • 5
  • 4
  • 3
  • Tagged with
  • 1187
  • 178
  • 169
  • 144
  • 125
  • 124
  • 118
  • 104
  • 91
  • 88
  • 77
  • 75
  • 74
  • 73
  • 66
  • 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.
251

Study on synchronization-oriented vendor managed inventory in dynamic supply chain ¡V The case of Fasteners industry in Taiwan

LAN, TE-SHAN 19 June 2007 (has links)
The screw nut (Fasteners) is known as the ¡§Rice of Industry¡¨. It is mainly applied on durable products such as automobile, electric apparatus, machinery, construction and building. Most of the durable products belong to the global products except the construction and building, which belong to regional. Due to the global competition, the competitions among the systems and supply chains have been formed. The improvement of the individual enterprise is not able to rely on the resource and ability of that organization only. It should operate across the border of the enterprises, and operate cooperatively with the downstream clients of the supply chains and the upstream manufacturers in order to improve the global competitiveness of the supply chain and seek for further development. Nowadays, the Vendor Managed Inventory (VMI) is the core of the trend of supply chain management (SCM) of global Fasteners industry. Taiwan is known as the empire of screw nut and it is not possible to neglect the operation trend of the global Fasteners market. This study attempts utilizing the characteristics of the System Dynamics, for which it is excellent on studying dynamic complicated system, to analyze the operation mechanism and structure of the Fasteners supply chain under VMI mode and applying synchronized mode. The individual dynamic model will be established to simulate the overall operation of the supply chain and compare the advantages and disadvantages of the two models. In addition, according to the major operation conditions and the demanding types, the model established by this study is utilized to develop the decision-making support tool for implementation of VMI mode of Fasteners industry. The conclusion of this study include (1) adding the synchronized model to Fasteners supply chain VMI mode can improve the operation performance of the enterprise, (2) to establish the design principle and steps of adding the design of synchronization to VMI mode. There are two contributions in this study: (1) the collocation of adding synchronization to the VMI mode model has proved that the combination with the synchronization mode can improve the performance of VMI mode. (2) The design principle and steps of adding the design of synchronization to VMI mode can be the reference for design steps of adding synchronization mode to the industry that implements VMI operation mode.
252

Intra-industry Trade and Business Cycle Synchronization in East Asia

Huang, Chin-hui 26 June 2007 (has links)
After East Asian financial crisis in 1997 and European monetary unification in 1999, if it is suitable of establishing the Asian common monetary area becomes the hot topic. The precondition of establishing the monetary policy cooperation depends on the synchronization of various countries¡¦ business cycle co-movement. And the trade is the connector among the countries. Trade linkages seemed to have an influence on business cycle co-movement. Countries with close international trade link are more likely to be members of an optimal currency area. According to the theoretical literature, the impact of trade integration on business cycle correlation may go either way. On the one hand, if trade occurs mainly by Heckscher-Ollin or is of the Ricardian type, higher specialization would induce the industrial structures of the trading countries to diverge, resulting in less synchronized movements of business cycle. In contrast, if trade occurs mainly through intra-industry trade, specialization does not necessarily lead to less synchronized. In summary, the total effect of trade intensity on cycle correlation is theoretically ambiguous and poses a question that could only be solved empirically. The volume of trade in East Asia has increased continuously. This paper extends the study of Frankel and Rose (1998) to analyze the impact of trade integration on business cycle correlation and intra-industry trade by using SITC data and other macroeconomic factors. Moreover, using two-stage estimation and instruments to take into account the fact that trade intensity itself may be endogenous. Then, we use panel data to estimate our equation. By gathering annual information of 10 East Asian countries from 1987 to 2005, we found that higher trade integration leads higher business cycle synchronization. To sum up, intra-industry trade is the process of establishing East Asian common monetary area.
253

New advances in synchronization of digital communication receivers

Wang, Yan 17 February 2005 (has links)
Synchronization is a challenging but very important task in communications. In digital communication systems, a hierarchy of synchronization problems has to be considered: carrier synchronization, symbol timing synchronization and frame synchronization. For bandwidth efficiency and burst transmission reasons, the former two synchronization steps tend to favor non-data aided (NDA or blind) techniques, while in general, the last one is usually solved by inserting repetitively known bits or words into the data sequence, and is referred to as a data-aided (DA) approach. Over the last two decades, extensive research work has been carried out to design nondata-aided timing recovery and carrier synchronization algorithms. Despite their importance and spread use, most of the existing blind synchronization algorithms are derived in an ad-hoc manner without exploiting optimally the entire available statistical information. In most cases their performance is evaluated by computer simulations, rigorous and complete performance analysis has not been performed yet. It turns out that a theoretical oriented approach is indispensable for studying the limit or bound of algorithms and comparing different methods. The main goal of this dissertation is to develop several novel signal processing frameworks that enable to analyze and improve the performance of the existing timing recovery and carrier synchronization algorithms. As byproducts of this analysis, unified methods for designing new computationally and statistically efficient (i.e., minimum variance estimators) blind feedforward synchronizers are developed. Our work consists of three tightly coupled research directions. First, a general and unified framework is proposed to develop optimal nonlinear least-squares (NLS) carrier recovery scheme for burst transmissions. A family of blind constellation-dependent optimal "matched" NLS carrier estimators is proposed for synchronization of burst transmissions fully modulated by PSK and QAM-constellations in additive white Gaussian noise channels. Second, a cyclostationary statistics based framework is proposed for designing computationally and statistically efficient robust blind symbol timing recovery for time-selective flat-fading channels. Lastly, dealing with the problem of frame synchronization, a simple and efficient data-aided approach is proposed for jointly estimating the frame boundary, the frequency-selective channel and the carrier frequency offset.
254

Pre- and post-synchronization methodologies to enhance the efficiency of fixed timed artificial insemination in pharmacologically-controlled breeding systems with Bos indicus-influenced cattle

Zuluaga Velez, Juan Federico 25 April 2007 (has links)
Objectives were to: 1) Evaluate the effectiveness of presynchronization with GnRH before the CO‐Synch + CIDR protocol with timed AI (TAI) at 66 h in Bos indicus‐influenced cattle; 2) Characterize ovarian events associated with the presynchronization; 3) Evaluate the efficacy of measuring vaginal electrical resistance (VER) to assess follicular maturity at TAI; and 4) Compare serum concentrations of progesterone (P4) in ovariectomized cows bearing new or previously used CIDR devices with or without autoclaving. In Exp. 1 and 2, cattle received either GnRH or saline on day ‐7. The CO‐Synch + CIDR protocol included a CIDR insert and GnRH (GnRH‐1; day 0), removal of CIDR and PGF2α on day 7, and GnRH (GnRH‐2) and TAI 66 h after CIDR removal. In Exp. 1, pregnancy rate of females with BCS ≥ 5 tended to differ (P=0.085) between Presynch (38%) and CO‐Synch + CIDR (54%). In Exp. 2, ovulatory response to GnRH‐1 was greater (P<0.01) in the Presynchronization (58%) than in the CO‐Synch + CIDR (27.1%) group. Emergence of a follicular wave after GnRH‐1 and ovulation rate after GnRH‐2 did not differ between groups. More (P<0.01) females that developed a follicular wave after GnRH‐1 ovulated (82%) after GnRH‐2, compared to those that did not (29%). Mean VER (ohms) was greatest (101.4±0.8) on day 0 and declined (P<0.01) to 95.2±0.8 and 82±0.8, respectively, on days 7 and 10. We observed a low negative but significant relationship (r=0.38; P<0.001) between VER and follicular size on day 0, 7, and 10. VER difference (day 10 minus day 7) did not differ between females with small and large follicles at TAI. Mean concentrations of P4 during the 7‐day insertion period were greater (P<0.03) for new (3.7 ng/ml) and re‐used autoclaved (3.4 ng/ml) than for re‐used disinfected CIDRs (2.8 ng/ml). In summary, Presynch improved ovulation rate after GnRH‐1, but did not improve pregnancy rates compared to CO‐Synch + CIDR. Follicular maturity estimation was not feasible using VER as applied in this study. Autoclaving may be the best option when re‐using CIDR inserts because it creates greater concentrations of P4 during the first 48 h.
255

Effects of interference on carrier tracking in fading and symbol synchronization

Emad, Amin. January 2009 (has links)
Thesis (M. Sc.)--University of Alberta, 2009. / Title from PDF file main screen (viewed on Dec. 14, 2009). "A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Master of Science, Department of Electrical and Computer Engineering, University of Alberta." Includes bibliographical references.
256

Application of e-TDR to achieve precise time synchronization and controlled asynchronization of remotely located signals

Sripada, Aparna 14 January 2014 (has links)
Time Domain Reflectometer (TDR) measures the electrical length of a cable from the applied end to the location of an impedance change. An impedance change causes a portion of the applied signal to reflect back based on the value of its reflection coefficient. The time of flight (TOF) between the applied and reflected wave is computed and multiplied with previously determined signal propagation velocity to determine the location of the impedance change. We intentionally open terminate the output end of the cable which makes the reflection coefficient be maximum (=1) to measure its electrical length. Conventional TDRs designed for testing integrity of long cables use various closed pulse shaped test signals i.e. the half sine wave and the Gaussian pulse, that disperse (change shape) and change velocity while propagation along the cable. Quoting Dr. Leon Brillouin’s comments on electromagnetic energy propagation [10], “in a vacuum, all waves (e.g. frequencies) propagate at the same velocity, hence withoutdistortion, whereas in a dispersive lossy media, except for an infinitely long sinusoidal waveform, distortion will occur due to frequency dependent velocity.” This signal distortion generally degrades the accuracy of the measurement of the signal’s TOF. We discuss here an Enhanced Resolution Time Domain Reflectometer (e-TDR). The enhanced resolution is due to a newly discovered signal called SPEEDY DELIVERY (SD) by Dr. Robert Flake at The University of Texas at Austin (US PATENT 6,441,695 B1 issued in August 27, 2002). This SD signal has a propagation velocity that is a programmable constant and this signal preserves its shape during propagation through dispersive lossy media (DLM). This signal behavior allows us to use ‘e-TDR’ in applications where remotely located signals need to be synchronized or asynchronized precisely. Potential applications include signal based synchronization of devices like sensors connected in a network. Since the cable carrying data from sensors at discrete and remote locations to a collecting center have different electrical lengths, it is necessary to precisely offset the timestamp of the incoming signal from these sensors to allow accurate data fusion. Our prototype is capable of synchronizing signals 1,200 ft (~ 400 m) apart with sub-nanosecond resolution. / text
257

Transparent replication

Nayate, Amol Pramod 28 August 2008 (has links)
Not available
258

A New Approach to Time Sync for Telemetry System

Lu, Chun, Kung, Changchun, Song, Jian 10 1900 (has links)
ITC/USA 2013 Conference Proceedings / The Forty-Ninth Annual International Telemetering Conference and Technical Exhibition / October 21-24, 2013 / Bally's Hotel & Convention Center, Las Vegas, NV / Instead of using a single data acquisition device, the distribute data acquisition system is broadly applied for onboard flight testing now. Therefore, the sync of data acquisition in varied devices and the real time data transportation have become the most important factors in a telemetry system. This paper presents a new approach to clock synchronization in a real time transportation network for a data acquisition system by using IRIG time code and an inner timer through network time recovery technique. This paper also illustrates how to keep the synchronization and continuity of a time tag used by each device through a precise estimation method for the difference of time resources and local inner timers.
259

Design of Basic Receiving Functions for an SDR Based Communication System

Manco, Angelo, Castrillo, Vittorio U. 10 1900 (has links)
The paper focuses on the design and implementation of the base-band basic receiving functions, for a binary CP-FSK demodulator pilot study, as independent modules of a complete Reconfigurable Data-Link (RDL). A model-based approach and Software Defined Radio (SDR) paradigm are used for the design. The implementation will be executed on Field-Programmable Gate Array (FPGA) based hardware.
260

外力を受ける非線形振動子のエネルギー収集特性 / Energy Harvesting Characteristics of Nonlinear Oscillators under Excitation

窪田, まど華 23 March 2015 (has links)
Kyoto University (京都大学) / 0048 / 新制・課程博士 / 博士(工学) / 甲第18991号 / 工博第4033号 / 新制||工||1621 / 31942 / 京都大学大学院工学研究科電気工学専攻 / (主査)教授 引原 隆士, 教授 土居 伸二, 教授 小林 哲生 / 学位規則第4条第1項該当

Page generated in 0.0361 seconds