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11. |
Analysis and design of frequency‐controlled oscillator for frequency‐locked stepping position control system |
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Journal of the Chinese Institute of Engineers,
Volume 17,
Issue 6,
1994,
Page 849-862
Guan‐Chyun Hsieh,
Mao‐Fu Lai,
Yen‐Pei Wu,
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摘要:
A frequency‐locked stepping position servo system (FLSPS) is presented. The proposed microprocessor‐based sloped‐varied frequency‐controlled oscillator (SVFCO) is designed to achieve nearly the same acquisition times for different position commands. The slope‐varied technique is to quickly position for long distance servo during the wide‐range control. The motion profiles for position locking are adaptively built according to the periodically sampled frequency error. No motion profiles are required to be pre‐installed in the controller. The system model is built for stability investigation and simulation. A design example is realized to verify the theoretical predictions. System simulation and experimentation confirm that the system acquisition times for short, middle, and long distance servos are very close to each other. In comparison with the corresponding traditional stepping position system, the acquisition times of the FLSPS are improved by 53% and 73%.
ISSN:0253-3839
DOI:10.1080/02533839.1994.9677654
出版商:Taylor & Francis Group
年代:1994
数据来源: Taylor
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12. |
A transceiver system for dual‐simplex high‐bit‐rate digital subscriber lines |
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Journal of the Chinese Institute of Engineers,
Volume 17,
Issue 6,
1994,
Page 863-869
Shyue‐Win Wei,
Hou‐Chun Ting,
Sheu‐Chih Cheng,
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PDF (525KB)
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摘要:
High bit‐rate digital subscriber lines (HDSL) technology is a new technology that may provide bi‐directional transmission at a rate of 1.544 Mb/s in conventional copper wires. A transceiver system for dual‐simplex (DSX)‐HDSL is presented. Simulation results show that the DSX‐HDSL system combined with simple pair‐selection can provide 18Kft/24AWG service distance without line repeaters. In the presented DSX‐HDSL transceiver, 2B1Q code with (1‐D) precoding is used to reduce the inter‐symbol interference (ISI) and the dynamic range of signal. Hence, a 12‐bit or less A/D converter can satisfy the performance requirement. In addition, another switchable (1‐D) filter is used in the receiver to shorten the duration of channel response, therefore a (5, 32) hybrid‐decision‐feedback‐equalizer (DFE) can obtain an adequate performance.
ISSN:0253-3839
DOI:10.1080/02533839.1994.9677655
出版商:Taylor & Francis Group
年代:1994
数据来源: Taylor
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13. |
Managing object schemas in a distributed database architecture for concurrent engineering |
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Journal of the Chinese Institute of Engineers,
Volume 17,
Issue 6,
1994,
Page 871-879
Hong‐Tai Chou,
Pao‐Hsu Shih,
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PDF (836KB)
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摘要:
In recent years, object database systems have emerged as a new technology, integrating object‐oriented paradigms with transaction and query capabilities of conventional database systems. The strength of distributed object database systems is further enhanced by new generations of powerful workstations. The synergy between object databases and the networked workstation environment, however, brings forth a new set of challenges. In this paper, we address the issues of managing object schemas in a cooperative network environment. After reviewing existing solutions, we present a more dynamic approach to the problem of distributed schema management. We also show how this approach can serve as a general framework for supporting various schema management policies.
ISSN:0253-3839
DOI:10.1080/02533839.1994.9677656
出版商:Taylor & Francis Group
年代:1994
数据来源: Taylor
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14. |
Decentralized robust control of multi‐machine power systems with a prescribed degree of stability |
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Journal of the Chinese Institute of Engineers,
Volume 17,
Issue 6,
1994,
Page 881-886
Cheng‐Jyi Mao,
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PDF (340KB)
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摘要:
This paper presents a completely decentralized scheme for the robust control of multi‐machine power systems with a prescribed degree of stability. By applying the optimal control technique to the nominal dynamics of each decomposed machine, the calculated optimal gains are multiplied by appropriate factors to account for the intrinsic uncertainties and nonlinear interactions among the machines. This subsystem‐based method can give the overall system an arbitrarily chosen degree of stability, where no state information is transferred. An example of a three‐machine power system is given below.
ISSN:0253-3839
DOI:10.1080/02533839.1994.9677657
出版商:Taylor & Francis Group
年代:1994
数据来源: Taylor
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15. |
Performance analysis of the maximum a posteriori probability direction finding |
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Journal of the Chinese Institute of Engineers,
Volume 17,
Issue 6,
1994,
Page 887-894
Yung‐Dar Huang,
Rong‐Yu Ruan,
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PDF (510KB)
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摘要:
In this paper, the mean square error performance of the maximum a posteriori (MAP) probability direction finding by sensor array in terms of its Cramer‐Rao lower bound (CRLB) is analyzed. Based on the principle of Bayesian estimator, a log posteriori probability function is formed when thea prioriknowledge of location is given. The Fisher information matrix (FIM) is found accordingly. It shows that the CRLB of the MAP estimator is much lower than that of maximum likelihood technique, especially when the element SNR is low and/or the number of snapshots is small. In addition, the CRLB remains at a relatively low level in terms of the variance of DOA of sources. It also shows that the location variance dominates the behavior of the MAP direction finder when locations of sources are Gaussian distributed.
ISSN:0253-3839
DOI:10.1080/02533839.1994.9677658
出版商:Taylor & Francis Group
年代:1994
数据来源: Taylor
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16. |
Editorial board |
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Journal of the Chinese Institute of Engineers,
Volume 17,
Issue 6,
1994,
Page -
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PDF (69KB)
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ISSN:0253-3839
DOI:10.1080/02533839.1994.9677643
出版商:Taylor & Francis Group
年代:1994
数据来源: Taylor
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