Browsing by Author "Chen, YG"

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A cut-based method for terminal-pair reliability
(1996-09-01)
Chen, YG
;
Yuang, MC
;
交大名義發表
;
資訊工程學系
;
National Chiao Tung University
Summ. & Conclusions - This paper assesses two categories of partition techniques for computing terminal-pair reliability (path-based and cut-based algorithms) by experimenting on published benchmarks; the criteria are the number of subproblems and the computation time. The cut-based algorithm is superior to the path-based algorithm with respect to the computation time for most benchmarks. A refinement of the cut-based algorithm (using network reduction) profoundly outperforms the path-based algorithm (with reduction) for all benchmarks.
A cut-based method for terminal-pair reliability
(1995)
Chen, YG
;
Yuang, MC
;
資訊工程學系
;
Department of Computer Science
A synchronization paradigm with QoS guarantees for multimedia communications
(1999)
Yuang, MC
;
Lo, BC
;
Chen, YG
;
Tien, PL
;
資訊工程學系
In this paper, we propose a synchronization paradigm, called SYNC*, offering two Quality of Service (QoS) requirements, skew and throughput, for multimedia communications. SYNC* is composed of three components: Intelligent Video Smoother (IVS), Synchronizer, and Multi-thread Priority Manager (MPM). While IVS and Synchronizer achieves intramedia and Intermedia synchronization, respectively, MPM ensures satisfactory throughput before playout. The main goal of the paper is to present in detail the design and performance analysis of the second component, Synchronizer. Synchronizer is aimed to achieve bounded skew between different media through periodic marking of correlated frames. The minimum marking interval yielding a given skew is analytically determined based on a Markov Batch Bernoulli Process (MBBP)/D/K/1 queueing model. We demonstrate the profound agreement between analytic and simulation results. The results also indicate that, the playout quality with respect to skew is highly relevant to the traffic burstiness and decoder buffer size. On the basis of a fixed marking interval, the greater the burstiness and buffer size, the poorer the playout quality.
DMTS: A distributed multimedia teleworking system
(1998-11-01)
Yuang, MC
;
Liu, JG
;
Chen, YG
;
Liu, JC
;
資訊工程學系
Multimedia systems combine a variety of information sources, such as voice, graphics, animation, images, and full-motion video, into a wide range of applications. The paper initially categorizes existing multimedia applications into three classes: noninteractive-oriented, interactive-oriented client-server-based, and interactive-oriented peer-party-based. In particular, the paper examines interactive-oriented applications and provides an in-depth survey of the media synchronization problem for the design of these applications. The paper then presents our prototyping system, called the Distributed Multimedia Teleworking System (DMTS), which allows two or more remote systems in collaboration to access and modify multimedia data through a network in a fully synchronous fashion. The system has been developed over TCP/IP and an FDDI network, using an XVideo D/A card. The media supported by DMTS include text, graphics, voice, and video. DMTS employs a master-slave collaboration model to maintain the coherence of the text and graphics data being simultaneously modified. Moreover, DMTS also adopts effective mechanisms to reduce skew (asynchrony) and jitter delays between video and voice streams. Finally, the paper demonstrates that DMTS achieves a maximum throughput of 13 frames per second, and reveals that the throughput bottleneck resides in the hardware capture and D/A processing of video frames.
DMTS: A distributed multimedia teleworking system
(1998-11-01)
Yuang, MC
;
Liu, JG
;
Chen, YG
;
Liu, JC
;
資訊工程學系
Multimedia systems combine a variety of information sources, such as voice, graphics, animation, images, and full-motion video, into a wide range of applications. The paper initially categorizes existing multimedia applications into three classes: noninteractive-oriented, interactive-oriented client-server-based, and interactive-oriented peer-party-based. In particular, the paper examines interactive-oriented applications and provides an in-depth survey of the media synchronization problem for the design of these applications. The paper then presents our prototyping system, called the Distributed Multimedia Teleworking System (DMTS), which allows two or more remote systems in collaboration to access and modify multimedia data through a network in a fully synchronous fashion. The system has been developed over TCP/IP and an FDDI network, using an XVideo D/A card. The media supported by DMTS include text, graphics, voice, and video. DMTS employs a master-slave collaboration model to maintain the coherence of the text and graphics data being simultaneously modified. Moreover, DMTS also adopts effective mechanisms to reduce skew (asynchrony) and jitter delays between video and voice streams. Finally, the paper demonstrates that DMTS achieves a maximum throughput of 13 frames per second, and reveals that the throughput bottleneck resides in the hardware capture and D/A processing of video frames.
Dynamic video playout smoothing method for multimedia applications
(1996)
Yuang, MC
;
Liang, ST
;
Chen, YG
;
Shen, CL
;
資訊工程學系
Dynamic video playout smoothing method for multimedia applications
(1998-01-01)
Yuang, MC
;
Liang, ST
;
Chen, YG
;
資訊工程學系
;
Department of Computer Science
Multimedia applications including video data require the smoothing of video playout to prevent potential discontinuity. In this paper, we propose a dynamic video playout smoothing method, called the Video Smoother, which dynamically adopts various playout rates in an attempt to compensate for high delay variance of networks. Specifically, if the number of frames in the buffer exceeds a given threshold (TH), the Smoother employs a maximum playout rate. Otherwise, the Smoother uses proportionally reduced rates in an effort to eliminate playout pauses resulting from the emptiness of the playout buffer. To determine THs under various loads, we present an analytic model assuming the interrupted Poisson Process (IPP) arrival. Based on the analytic results, we establish a paradigm of determining THs and playout rates for achieving different playout qualities under various loads of networks. Finally, to demonstrate the viability of the Video Smoother, we have implemented a prototyping system including a multimedia teleconferencing application and the Video Smoother performing as part of the transport layer. The prototyping results show that the Video Smoother achieves smooth playout incurring only unnoticeable delays.
Dynamic video playout smoothing method for multimedia applications
(1998-01-01)
Yuang, MC
;
Liang, ST
;
Chen, YG
;
資訊工程學系
;
Department of Computer Science
Multimedia applications including video data require the smoothing of video playout to prevent potential discontinuity. In this paper, we propose a dynamic video playout smoothing method, called the Video Smoother, which dynamically adopts various playout rates in an attempt to compensate for high delay variance of networks. Specifically, if the number of frames in the buffer exceeds a given threshold (TH), the Smoother employs a maximum playout rate. Otherwise, the Smoother uses proportionally reduced rates in an effort to eliminate playout pauses resulting from the emptiness of the playout buffer. To determine THs under various loads, we present an analytic model assuming the interrupted Poisson Process (IPP) arrival. Based on the analytic results, we establish a paradigm of determining THs and playout rates for achieving different playout qualities under various loads of networks. Finally, to demonstrate the viability of the Video Smoother, we have implemented a prototyping system including a multimedia teleconferencing application and the Video Smoother performing as part of the transport layer. The prototyping results show that the Video Smoother achieves smooth playout incurring only unnoticeable delays.
Terminal-pair Reliability in ATM Virtual Path networks
(1997)
Chen, YG
;
Hsu, SJ
;
Yuang, MC
;
交大名義發表
;
資訊工程學系
Terminal-pair Reliability (TR) in an Asynchronous Transfer Mode (ATM) Virtual Path (VP) network corresponds to probabilistic quantization of robustness between two VP terminators, given a VP layout and failure probabilities of physical links. Existing TR algorithms are unviable for ATM VP networks owing to either high complexity or failure dependency among VPs. The goal of the paper is to propose two efficient algorithms for TR computation between two VP terminators by means of variants of path-based and cut-based partition methods which have been effectively used for TR computation in traditional networks. The first variant, called the Path-based Virtual Path Reliability (PVPR) algorithm, partitions the search space based on a physical path embedding the shortest route of VPs from the source to the destination terminator. The second variant, called the Cut-based Virtual Path Reliability (CVPR) algorithm, in lieu, performs the partition on the basis of a physical cutset separating the source from the remaining terminators. In both algorithms, each subproblem is recursively processed by means of partition until the source and destination terminators are contracted or disconnected. Experimental results reveal that, CVPR outperforms PVPR with respect to computation time. Moreover, compared to one of the most promising TR algorithms, both CVPR and PVPR exhibit superior performance. The two algorithms and their promising results consequently facilitate the real-time computation of the reliability or robustness of ATM VP networks.
Terminal-pair reliability in ATM virtual path networks
(2000-09-01)
Hsu, SJ
;
Chen, YG
;
Yuang, MC
;
資訊工程學系
;
Department of Computer Science
Terminal-pair reliability (TR) in an asynchronous transfer mode (ATM) Virtual path (VP) network corresponds to probabilistic quantification of robustness between two VP terminators, given the VP layout and the failure probabilities of physical links. Existing TR algorithms are shown to be unviable for ATM VP networks owing to either high complexities or failure dependency among VPs. The goal of the paper is to propose efficient algorithms for the computation of TR between two VP terminators by means of variants of path-based and cut-based partition methods which have been effectively used for the computation of TR in traditional networks. The first variant, called the path-based virtual path reliability (PVPR) algorithm, partitions the search space based on a physical path embedding the shortest route of VPs from the source terminator to the destination terminator. The second variant, called the cut-based Virtual path reliability (CVPR) algorithm, in lieu, performs the partition on the basis of a physical outset separating the source from the remaining terminators. In both algorithms, each subproblem is recursively processed by means of partition until the source and destination terminators are contracted or disconnected. Experimental results demonstrate that, compared to one promising TR algorithm (called EBRM), both the PVPR and CVPR algorithms improve the running time by five orders of magnitude. In particular, the CVPR outperforms EBRM more than PVPR does in terms of computation time. The two algorithms and their promising results consequently facilitate the real-time computation of the reliability or robustness of ATM VP networks. (C) 2000 Elsevier Science Ltd. All rights reserved.