Browsing by Author "Wang, Yi-Hsien"

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A hierarchical push-pull scheme for peer-to-peer live streaming
(2008)
Gau, Victor
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Wang, Yi-Hsien
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Hwang, Jenq-Neng
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資訊工程學系
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Department of Computer Science
In this paper, we propose a hierarchical push-pull scheme for peer-to-peer (P2P) live streaming. In our scheme, a control topology is used for membership management, and a multi-source multicast tree for data delivery. The control topology facilitates peers to locate multiple sources for forwarding media content, and the multi-source multicast tree makes the system adaptive to node churn and packet loss. Simulation results show that our proposed method is significantly better than BT-Like systems.
A portable AWT/Swing architecture for Java game development
(2007-06-01)
Wang, Yi-Hsien
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Wu, I-Chen
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Jiang, Jyh-Yaw
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資訊工程學系
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Department of Computer Science
Recently, the performance of Java platforms has been greatly improved to satisfy the requirements for game development. However, the rendering performance of Java 1.1, which is still used by about one-third of current Web browser users, is not sufficient for high-profile games. Therefore, practically, Java game developers, especially those who use applets, have to take this into consideration in most environments. In order to solve the above problems, this paper proposes a portable window toolkit architecture called the CYC Window Toolkit (CWT) with the ability to: (1) reach high rendering performance particularly in Java 1.1 applications and applets when using DirectX to render widgets in CWT; (2) support AWT/Swing compatible widgets, so hence the CWT can be easily applied to existing Java games; (3) define a general architecture that supports multiple graphics libraries such as AWT, DirectX and OpenGL, multiple virtual machines such as Java VM and NET CLR, and multiple operating systems (OSs) such as Microsoft Windows, Mac OS and UNIX-based OSs; (4) provide programmers with one-to-one mapping APIs to directly manipulate DirectX objects and other game-related properties. The CWT has also been applied to an online Java game system to demonstrate the proposed architecture. Copyright (C) 2006 John Wiley & Sons, Ltd.
Achieving high and consistent rendering performance of Java AWT/Swing on multiple platforms
(2009-05-01)
Wang, Yi-Hsien
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Wu, I-Chen
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資訊工程學系
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Department of Computer Science
Wang et al. (Softw. Pract. Exper. 2007; 37(7):727-745) observed a phenomenon of performance inconsistency in the graphics of Java Abstract Window Toolkit (AWT)/Swing among different Java runtime environments (JREs) on Windows XP This phenomenon makes it difficult to predict the performance of Java game applications. Therefore, they proposed a portable AWT/Swing architecture, called CYC Window Toolkit (CWT), to provide programmers with high and consistent rendering performance for Java game development among different JREs. They implemented a DirectX version to demonstrate the feasibility of the architecture. This paper extends the above research to other environments in two aspects. First, we evaluate the rendering performance of the original Java AWT with different combinations of JREs, image application programming interfaces, system properties and operating systems (OSs), including Windows XP, Windows Vista, Fedora and Mac OS X. The evaluation results indicate that the performance inconsistency of Java AWT also exists among the four OSs, even if the same hardware configuration is used. Second, we design an OpenGL version of CWT, named CWT-GL, to take advantage of modern 3D graphics cards, and compare the rendering performance of CWT with Java AWT/Swing. The results show that CWT-GL achieves more consistent and higher rendering performance in JREs 1.4 to 1.6 on the four OSs. The results also hint at two approaches: (a) decouple the rendering pipelines of Java AWT/Swing from the JREs for faster upgrading and supporting old JREs and (b) use other graphics libraries, such as CWT, instead of Java AWT/Swing to develop cross-platform Java games with higher and more consistent rendering performance. Copyright (C) 2009 John Wiley & Sons, Ltd.
Generalization Performance Analysis of Flow-based Peer-to-Peer Traffic Identification
(2008)
Wang, Yi-Hsien
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Gau, Victor
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Bosaw, Trevor
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Hwang, Jenq-Neng
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Lippman, Alan
In this paper, we develop a peer-to-peer (P2P) traffic identifier to facilitate quality of service (QoS) control in edge routers. Currently, since P2P applications consume a great percentage of Internet bandwidth, certain network optimization strategies are needed to improve the nerwork performance. Traffic identification is the most important component that could be adopted in these optimization strategies. In this paper, we focus on developing a machine learning strategy to perform quick identification, and continuous tracking of flows associated with various P2P media streaming and file sharing applications. With the use (if Random Forests (RF) and evaluated by using 10-fold cross validation, our method achieves greater than 98% accuracy rate and 89% precision rate of identifying the P2P flows, with less than 1% false positive rate. With the help of winner-lake-all strategy, the generalization performance of using the RF built with data collected from one network to classify flows in other networks can achieve accuracy of being over 97%, with the precision being over 81% and the FP rate being below 2%.