Browsing by Author "Huang, TL"

Now showing 1 - 13 of 13

A causal multicast protocol for mobile distributed systems
(2000-12-01)
Chi, KH
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Yen, LH
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Tseng, CC
;
Huang, TL
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資訊工程學系
Causal message ordering in the context of group communication ensures that ail the message receivers observe consistent ordering of events affecting a group as a whole. This paper presents a scalable causal multicast protocol for mobile distributed computing systems. In our protocol, only a Dart of the mobility agents in the system is involved in group computations and the resulting size of control information in messages can be kept small. Our protocol can outperform qualitatively the counterparts in terms of communication overhead and hand-off complexity An analytical model is also developed to evaluate our proposal. The performance results show that the proposed protocol is promising.
A comment on "A circular list-based mutual exclusion scheme for large shared-memory multiprocessors"
(1998-04-01)
Huang, TL
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Shann, CH
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資訊工程學系
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Department of Computer Science
The circular list-based mutual exclusion algorithm proposed by Fu and Tzeng [1] is subject to a race condition that leads to a deadlock under subtle situations. An execution sequence evidences the race, and a modified version is provided. The performance of the original algorithm remains unchanged.
A fair and space-efficient mutual exclusion
(2005)
Chen, SH
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Huang, TL
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資訊工程學系
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Department of Computer Science
For shared memory systems with time and resource constraints such as embedded real-time systems, mutual exclusion mechanism that is both fair and space-efficient can be very useful. In this paper, we present a boundedbypass algorithm using only two shared variables, regardless of the number of contending processes, by operation fetch&store as well as atomic read/write. To achieve the same level of fairness, we show that, by the same set of operations, two shared variables are necessary, and therefore our algorithm is space-optimal.
A framework for mobile multicast using dynamic route reconstructions
(1999)
Chi, KH
;
Tseng, CC
;
Huang, TL
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交大名義發表
;
資訊工程學系
A mobile computing environment allows hosts to roam while retaining access to the Internet, Multicasting is one of the most important facilities for constructing reliable distributed systems and cooperative applications. Host mobility, however, challenges multicasting in this environment: the established multicast delivery paths may frequently restructure along with host migrations, incurring expensive overheads, This paper presents a framework for network-layer multicasting while keeping a low overhead in adapting multicast routes to mobile host locations. This is achieved by partitioning the mobile environment into non-overlapping regions, so that changes in the multicast routes due to host intra-region movements are hidden from other regions, An analytical model was developed for performance evaluation. It shows that, compared with the best known proposal, our scheme reduces the average multicast latency by more than 66%, while causing less than 7% overhead.
A new locality-based IP multicasting scheme for mobile hosts
(2001-03-15)
Tseng, CC
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Chi, KH
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Huang, TL
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資訊工程學系
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Department of Computer Science
Internet protocol multicasting is a mechanism widely used in the Internet to disseminate information. Multicast delivery paths may need to be frequently restructured along with host migrations, at the expense of nontrivial overhead or multicast latency. This paper presents a scheme with short multicast latency, while retaining acceptable overhead in adapting the delivery paths to mobile host locations. We exploit the locality in host movements and keep active the networks that mobile hosts have most recently visited. As long as hosts migrate within these active networks, multicast delivery paths can remain unchanged upon host movements. Performance results show that, compared with the best known proposal, our scheme is promising. (C) 2001 Elsevier Science B.V. All rights reserved.
A practical nonblocking queue algorithm using compare-and-swap
(2000)
Shann, CH
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Huang, TL
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Chen, C
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資訊工程學系
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Department of Computer Science
Many nonblocking algorithms have been proposed for shared queues. Previous studies indicate that link-based algorithms perform best. However, these algorithms have a memory management problem. a dequeued node can not be freed or reused without problem: handling. The problem is usually overloaded; one just assumes the existence of a lower level mechanism, which takes care of all the details of handling the problem. Employing such a mechanism incurs significant overheads, and consequently the link-based queues may not perform as well as claimed. A new nonblocking queue algorithm based on a finite array is proposed in this paper. Comparing with the link-based algorithms. the nerv algorithm provides the same degree of concurrency without being subject to the memory problem, hence suggests a good performance.
Development of panel loudspeaker system: Design, evaluation and enhancement
(2001-06-01)
Bai, MSR
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Huang, TL
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機械工程學系
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Department of Mechanical Engineering
Panel speakers are investigated in terms of structural vibration and acoustic radiation. A panel speaker primarily consists of a panel and an inertia exciter. Contrary to conventional speakers, flexural resonance is encouraged such that the panel vibrates as randomly as possible. Simulation tools are developed to facilitate system integration of panel speakers. In particular, electro-mechanical analogy, finite element analysis, and fast Fourier transform are employed to predict panel vibration and the acoustic radiation. Design procedures are also summarized. In order to compare the panel speakers with the conventional speakers, experimental investigations were undertaken to evaluate frequency response, directional response, sensitivity, efficiency, and harmonic distortion of both speakers. The results revealed that the panel speakers suffered from a problem of sensitivity and efficiency. To alleviate the problem, a woofer-using electronic compensation based on H-2 model matching principle is utilized to supplement the bass response. As indicated in the result, significant improvement over the panel speaker alone was achieved by using the combined panel-woofer system. (C) 2001 Acoustical Society of America.
Fast and fair mutual exclusion for shared memory systems
(1999)
Huang, TL
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資訊工程學系
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Department of Computer Science
Two fast mutual exclusion algorithms using read-modify-write and atomic read/write registers are presented. The first one uses both compare&swap and fetch&store; the second uses only fetch&store. Fetch&store are more commonly available than compare&swap. It is impossible to obtain better algorithms if "time" is measured by counting remote memory references. We were able to maintain the same level of performance with or without the support of compare&swap. However, fairness is degraded from 1-bounded bypass to lockout freedom without the support.
Fast mutual exclusion algorithms using read-modify-write and atomic read/write registers
(1998)
Huang, TL
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資訊工程學系
;
Department of Computer Science
Three fast mutual exclusion algorithms using read-modify-write and atomic read/write registers are presented in a sequence, with an improvement from one to the next. The last algorithm is shown to be optimal in minimizing the number of remote memory accesses required in a resource busy period. Remote memory access is the key factor of memory access bottleneck in large shared-memory multiprocessors. The algorithm is particularly suitable in such systems for applications with small critical sections and frequent resource requests.
International development of Taiwan's information industry: An empirical study on human resource strategy of overseas subsidiaries
(1998-08-01)
Liu, SJ
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Huang, TL
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Chen, QH
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科技管理研究所
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Institute of Management of Technology
Since the 1980's, personal computers (PC's) and semiconductors have emerged as Taiwan's two leading high-technology industries. As of the 1990's, Taiwan has attained third place among PC manufacturers, and PC's and peripherals have become Taiwan's largest export products. Entrepreneurial small businesses, fierce competition in the local economy, and efficient industrial networking characterize Taiwan's PC industry, with flexible production and shortened time to market. This study investigates the human resource strategies of overseas subsidiaries of Taiwan's information enterprises, primarily the PC production industry. Gaining the comparative advantages of production from foreign resources of labor, materials, and key components are among the prime concerns. Direct access to foreign markets and marketing information constitute that more offices be established abroad. In general, internationalization of Taiwan's PC industry partakes more of a headquarters-controlled style of global management, Overseas subsidiaries are essentially extensions of Taiwan- and manufacturing-based PC enterprises. This study integrates theoretical frameworks of the eclectic paradigm and the integration-responsiveness models and explores four strategic patterns of human resource on the basis of two dimensions: consistency with parent-company policy and local responsiveness of a foreign subsidiary, Statistical measures as well as qualitative analysis reveal that both domestic corporate characteristics and overseas local features significantly influence management policy, While Taiwanese information enterprises are increasingly moving toward global expansion, the majority are at a learning stage in international business development. Internalization of Taiwan's PC industry primarily depends on the manufacturing capability of local headquarters and joint ventures with foreign companies. The manufacturing-based PC industry in Taiwan is moving toward key component production and brand marketing while integrating global resources to compete against established transnational corporations.
Reachability testing: An approach to testing concurrent software
(1995-12-01)
Hwang, GH
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Tai, KC
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Huang, TL
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資訊工程學系
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Department of Computer Science
Concurrent programs are more difficult to test than sequential programs because of nondeterministic behavior. An execution of a concurrent program non-deterministically exercises a sequence of synchronization events called a synchronization sequence (or SYN-sequence). Non-deterministic testing of a concurrent program P is to execute P with a given input many times in order to exercise distinct SYN-sequences. In this paper, we present a new testing approach called reachability testing. If every execution of P with input X terminates, reachability testing of P with input X derives and executes all possible SYN-sequences of P with input X. We show how to perform reachability testing of concurrent programs using read and write operations. Also, we present results of empirical studies comparing reachability and non-deterministic testing. Our results indicate that reachability testing has advantages over non-deterministic testing.
Resetting vector clocks in distributed systems
(1997-05-25)
Yen, LH
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Huang, TL
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交大名義發表
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資訊工程學系
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National Chiao Tung University
This paper establishes the necessary and sufficient condition for a correct clock resetting such that the functionality of vector clocks can be preserved. A clock reset protocol is presented with its applicability and limitation discussed. Our result indicates that for some applications, the potential of clock overflow can be completely prevented by carefully choosing the condition for initiating the clock reset protocol. (C) 1997 Academic Press.
Resetting vector clocks in distributed systems
(1997-05-25)
Yen, LH
;
Huang, TL
;
資訊工程學系
;
Department of Computer Science
This paper establishes the necessary and sufficient condition for a correct clock resetting such that the functionality of vector clocks can be preserved. A clock reset protocol is presented with its applicability and limitation discussed. Our result indicates that for some applications, the potential of clock overflow can be completely prevented by carefully choosing the condition for initiating the clock reset protocol. (C) 1997 Academic Press.