Browsing by Author "Tseng, SM"

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A widely tunable side-polished fiber filter based on dispersive evanescent wave tunneling
(2004)
Chen, NK
;
Chi, S
;
Tseng, SM
;
光電工程學系
;
Department of Photonics
An adaptive value-based scheduling policy for multiprocessor real-time database systems
(1997)
Tseng, SM
;
Chin, YH
;
Yang, WP
;
交大名義發表
;
資訊工程學系
In a real-time application, a transaction may be assigned a value to reflect the profit of completing the transaction before its deadline. Satisfying both goals of maximizing the totally obtained profit and minimizing the number of missed transactions at the same time is a challenge. In this paper we present an adaptive real-time scheduling policy named Value-based Processor Allocation (VPA-k) for scheduling value-based transactions in a multiprocessor real-time database system. Using VPA-k policy, the transactions with higher values are given higher priorities to execute first, while at most k percentage of total processors are dynamically allocated to execute the urgent transactions. Through simulation experiments, VPA-k is shown to outperform other scheduling policies substantially in bath maximizing the totally obtained profit mid minimizing the number of missed transactions under various system environments.
An efficient local fundamental-mode cutoff for thermo-optic tunable Er3+-doped fiber ring laser
(2005-09-05)
Chen, NK
;
Chi, S
;
Tseng, SM
;
光電工程學系
;
Department of Photonics
We demonstrate a continuously tunable Er3+-doped fiber laser by incorporating a short-pass filter, which provides a wideband tunable fundamental-mode cutoff with high rejection efficiency (> 45 dB/cm) at long wavelengths, into a ring resonator. The tunable short-pass filter locally suppresses the gain profile of the Er3+-doped fiber at long wavelengths and makes the lasing wavelength continuously move toward short wavelengths when optical polymer is cooling down. The tuning efficiency, tuning range, signal-ASE-ratio, and FWHM linewidth of the laser are 7.65 nm/degrees C, 26 nm (1569.8 similar to 1595.8 nm), 40 dB, and 0.5 nm, respectively.
Integrated business agents for processing free text information
(2004-03-01)
Meng, IH
;
Tseng, SM
;
Yang, WP
;
資訊工程學系
;
Department of Computer Science
The Internet functions as an increasingly important channel for retailing commerce and business transactions. Although nearly five billion web sites exist on the World Wide Web, an integrated mediator, called a business agent, is sought to negotiate between suppliers and buyers. Such an intelligent business broker is thus necessary to support efficient and effective sharing of information. This work proposes an entirely new business agent architecture comprised of five elements, namely Business Spy Agent, Supply and Demand Analysis, Supply and Demand Classification, Matching and Negotiation, and Hidden Business Mining. The proposed architecture encompasses four trading processes, including Supply and demand identification, product brokering, merchant brokering and negotiation. The architecture introduces the notion of ontology to increase the precision of classification and more the effectiveness of negotiation. Experiments involving the proposed business agent show a significant successful pairing rate of 82% among suppliers and buyers. Simulation results indicate that the options, including Negotiable, Designated Brand and Split Demand, affect the match ratio differently from various perspectives.
Narrow-band channel-dropping filter based on side-polished fiber with long interaction length
(2004-04-01)
Chen, NK
;
Chi, S
;
Tseng, SM
;
電子工程學系及電子研究所
;
光電工程學系
We demonstrate an all-fiber channel-dropping filter comprising a 2 x 2 side-polished fiber coupler with long coupling length and a narrow-band fiber Bragg grating. The side-polished fibers are fabricated on a silicon wafer acting as a polishing substrate while the alignment V-grooves are simultaneously prepared. Two polished fibers with an intracore Bragg grating between them are combined as a grating-frustrated coupler, and a low-loss channel-dropping filter was achieved with the spectral bandwidth less than 2 nm (25 dB), dropping efficiency greater than 98% and channel isolation greater than 25 dB. The filter can be manufactured through a fast and reliable fabrication process.
Performance evaluation of a high-value scheduling policy for real-time main memory databases
(1996-09-01)
Tseng, SM
;
Chin, YH
;
Yang, WP
;
資訊工程學系
;
Department of Computer Science
With the decrease in hardware prices, storing databases in main memory has become feasible for meeting the high-performance requirements of real-time applications. In this paper, an efficient scheduling policy is proposed for scheduling transactions with values in real- time main memory databases, where the value of a transaction means its worthiness to a real-time application of it is completed before the deadline. Through detailed performance evaluation, the proposed policy is shown to outperform the existing policies in both minimizing the number of missed transactions and maximizing the obtained values under various system environments. A cost formula for evaluating the optimal memory size to store partial databases such as to maximize the net profits is developed from the economic standpoint. Some suggestions are given for scheduling value-based transactions in real-time main memory databases.
Performance evaluation of a high-value scheduling policy for real-time main memory databases
(1996-09-01)
Tseng, SM
;
Chin, YH
;
Yang, WP
;
資訊工程學系
;
Department of Computer Science
With the decrease in hardware prices, storing databases in main memory has become feasible for meeting the high-performance requirements of real-time applications. In this paper, an efficient scheduling policy is proposed for scheduling transactions with values in real- time main memory databases, where the value of a transaction means its worthiness to a real-time application of it is completed before the deadline. Through detailed performance evaluation, the proposed policy is shown to outperform the existing policies in both minimizing the number of missed transactions and maximizing the obtained values under various system environments. A cost formula for evaluating the optimal memory size to store partial databases such as to maximize the net profits is developed from the economic standpoint. Some suggestions are given for scheduling value-based transactions in real-time main memory databases.
Precision side-polished fibers with a long interaction length
(1997-09-15)
Liaw, SK
;
Chiu, JY
;
Tseng, SM
;
光電工程學系
;
Department of Photonics
We succeeded in fabricating precision side-polished fibers embedded in silicon V-grooves and then polished six fibers using a home-made polisher. The control of the polishing depth of the side-polished fibers was as accurate as +/-0.25 mu m. Another merit of our polished samples was their negligible losses even though the effective interaction lengths were long. Experimental calibrations of our samples agreed with theoretical results.
Precision side-polished fibers with a long interaction length
(1997-09-15)
Liaw, SK
;
Chiu, JY
;
Tseng, SM
;
光電工程研究所
;
Institute of EO Enginerring
We succeeded in fabricating precision side-polished fibers embedded in silicon V-grooves and then polished six fibers using a home-made polisher. The control of the polishing depth of the side-polished fibers was as accurate as +/-0.25 mu m. Another merit of our polished samples was their negligible losses even though the effective interaction lengths were long. Experimental calibrations of our samples agreed with theoretical results.
Value-based scheduling for multiprocessor real-time database systems
(1998-01-01)
Tseng, SM
;
Chin, YH
;
Yang, WP
;
資訊工程學系
;
Department of Computer Science
We present a new scheduling policy named Value-based Processor Allocation (VPA-k) for scheduling value-based transactions in a multiprocessor real-time database system. The value of a transaction represents the profit the transaction contributes to the system if it is completed before its deadline. Using VPA-k policy, the transactions with higher values are given higher priorities to execute first, while at most k percentage of the total processors are allocated to the urgent transactions dynamically. Through simulation experiments, VPA-k policy is shown to outperform other scheduling policies substantially in both maximizing the totally obtained values and minimizing the number of missed transactions.
Value-based scheduling for multiprocessor real-time database systems
(1998-01-01)
Tseng, SM
;
Chin, YH
;
Yang, WP
;
資訊工程學系
;
Department of Computer Science
We present a new scheduling policy named Value-based Processor Allocation (VPA-k) for scheduling value-based transactions in a multiprocessor real-time database system. The value of a transaction represents the profit the transaction contributes to the system if it is completed before its deadline. Using VPA-k policy, the transactions with higher values are given higher priorities to execute first, while at most k percentage of the total processors are allocated to the urgent transactions dynamically. Through simulation experiments, VPA-k policy is shown to outperform other scheduling policies substantially in both maximizing the totally obtained values and minimizing the number of missed transactions.
Wideband tunable fiber short-pass filter based on side-polished fiber with dispersive polymer overlay
(2004-10-01)
Chen, NK
;
Chi, S
;
Tseng, SM
;
光電工程學系
;
Department of Photonics
It is known that dispersive fiber has an LP01 mode cutoff wavelength that acts as a wavelength filter. With a dispersive polysiloxane polymer overlay on a side-polished single-mode fiber, an in-line tunable fiber short-pass filter with a tuning range of similar to400 nm (1250-1650 nm) and a temperature variation of 15 degreesC was demonstrated. The rejection efficiency was greater than 50 dB, whereas the insertion and polarization-dependent losses were below 0.26 and 0.09 dB, respectively. (C) 2004 Optical Society of America.