36972963
A real-time synchronization model and transport protocol for multimedia applications
In considering a transport layer protocol for multimedia applications in packet networks, real-time and synchronization characteristics of multimedia applications have to be considered. Synchronization means that the intermedium temporal relationship for an application has to be satisfied, after the transmission across the network. Since the random delay of packet networks makes synchronization among media more complicated, a model is required to specify the temporal relationship among media across the network which can be easily implemented in a transport protocol. In the paper, a real-time synchronization model (RTSM), is presented for synchronization, and a new protocol, namely MSTP (multimedia synchronization transport protocol), is proposed based on RTSM.<<ETX>>
6374629
A Multimedia Synchronization Model and Its Implementation in Transport Protocols
An implementation of a synchronization mechanism in transport protocol to support multimedia applications over a packet or cell switched network is proposed. In designing such a mechanism for practical use, ease of implementation and capability of handling random delay of packets are two key issues for success. Since the random delay of packet or cell switched networks makes synchronization among media more complicated after the transmission across the network, a model which considers the random transmission delay is hence required to specify the temporal relationship among media. Therefore, a real-time synchronization model is presented to satisfy this requirement in the paper. Based on the proposed synchronization model, a transport protocol, namely the multimedia synchronization transport protocol (MSTP), is designed and implemented. We have implemented a prototype system using the MSTP protocol and built a simulation system for the wide area network (WAN) environment in order to evaluate the performance of the MSTP protocol.
6411174
SMILAuthor: An Authoring System for SMIL-Based Multimedia Presentations
In this paper, an authoring tool named SMILAuthor for SMIL-based multimedia presentations is proposed. SMILAuthor adopts standard SMIL language as the format of the presentation to generate reusable and easily accessible presentations. Moreover, powerful editing functions such as cut, copy, and paste are supported by the system in a timeline-based manner. In order to support timeline-based editing functions, the playback duration of each object in the input SMIL script is first calculated by the parsing process of the system. The parsing process extracts and converts the temporal relationship of the input script to Real-Time Synchronization Model (RTSM), and the playback duration of each object in the script is then computed by traversing the RTSM. Editing results are converted to the SMIL format and saved in the output file. Language structure of SMIL is hidden by the system and the temporal information is visualized in the timeline manner to provide users an easy way to understand and control the timing of each object. Implementation of the system provides a friendly WYSIWYG environment and multiple views/windows are provided by the system to help authors compose multimedia presentations efficiently.
6557904
A Novel Congestion Control Mechanism for Multicast Real-Time Connections
Time framing strategies such as Stop-and-Go (SG Golestani S.J., A framing strategy for congestion management, IEEE JSAC, 9(7), 1991, pp.1064-1077; Golestani S.J., Congestion-free communication in high-speed packet networks, IEEE Trans. on Communications, 39(12), 1991, pp.1802-1812; Golestani S.J., A stop-and-go queueing framework for congestion management, ACM SIGCOMM, 1992, pp.8-18] and Continuous Framing (CF) [Jau-Hsiung Huang, Biau-Jwo Tsaur, Continuous framing mechanism for congestion control in broadband networks, Computer Communications, 18(10), 1995, pp.718-724] are designed to support the end-to-end delay bound and jitter bound for unicast connections. Considering the features of real-time multicast connections, a new time framing mechanism named Multicast Continuous Framing (MCF) is proposed in this article. S&G and CF allow only one time frame length per connection, but MCF allows changing of the time frame length of a connection at intermediate nodes so that the statistical multiplexing gain within a connection is increased, i.e., the bandwidth requirement can be reduced. We also present the multicast connection setup scheme for MCF in the article. Simulation results show that MCF has a much better performance than that of CF, and the tighter jitter bound a connection requests, the more performance improvement MCF can obtain.
8861403
Design and implementation of the just-in-time retrieving policy for schedule-based distributed multimedia presentations
In order to provide the smooth playback of a distributed multimedia presentation, the object-retrieving engine for the player must fetch each object before its playback time. In this paper, a smart object-retrieving engine is proposed, which adopts a retrieving policy named the just-in-time policy. The policy expects the retrieval process of an object to finish right before the playback time of the object to achieve a better buffer utilization and network bandwidth efficiency. The proposed object-retrieving engine focuses on SMIL1.0-based multimedia presentations. By converting the synchronization relationship of objects in the SMIL 1.0 document to Real-Time Synchronization Model, which simplifies the handling of the synchronization relationship, and considering the end-to-end bandwidth as well as the user interactions, the object-retrieving engine determines the object request time for each object. The engine issues the request to fetch each object for the ongoing presentation at the object request time, and provides the player with proper media objects. The feasibility and better performance of the proposed just-in-time retrieving policy had been proved by performance measurements of system implementation.
14699908
Performance Analysis of Applying Replica Selection Technology for Data Grid Environments
The Data Grid enables the sharing, selection, and connection of a wide variety of geographically distributed computational and storage resources for solving large-scale data intensive scientific applications. Such technology efficiently manage and transfer terabytes or even petabytes of data for data-intensive, high-performance computing applications in wide-area, distributed computing environments. Replica selection process allows an application to choose a replica from replica catalog, based on its performance and data access features. In this paper, we build a Grid environment based on three existing PC Cluster environments and perform performance analysis of data transfers using GridFTP protocol over these systems. In addition, based on experimental results, it is proposed a cost model to pick the best replica, in real and dynamic network situations.
15185752
Specifying distributed multi-agent systems in chemical reaction metaphor
This paper presents an application of Chemical Reaction Metaphor (CRM) in distributed multi-agent systems (MAS). The suitability of using CRM to model multi-agent systems is justified by CRM's capacity in specifying dynamic features of multi-agent systems. A case study in an agent-based e-learning system (course material updating) demonstrates how the CRM based language, Gamma, can be used to specify the architectures of multi-agent systems. The effectiveness of specifying multi-agent systems in CRM from the view point of software engineering is further justified by introducing a transformational method for implementing the specified multi-agent systems. A computation model with a tree-structured architecture is proposed to base the design of the specified multi-agent system during the implementation phase. A module language based on the computation model is introduced as an intermediate language to facilitate the translation of the specification of multi-agent systems. The multicast networking technology pragmatizes the implementation of communications and synchronization among distributed agents. The paper also discusses the feasibility of implementing an automatic translation from the Gamma specification to a program in the module language.
45556411
On Implementation of a Scalable Wallet-Size Cluster Computing System for Multimedia Applications
In order to obtain a low-cost, low-power consumption and small sized digital home processing center, especially for multimedia applications, we propose a scalable wallet-size cluster computing system in this paper. Such system uses low-cost, low-power consumption and small sized microprocessors as computing nodes to form a cluster system. 
 
The main reason why we are interested to investigate and build such system is to increase the computing power and to accelerate the H.264 video processing. We analyzed the H.264 decoder scheme and distributed the most heavy-load computations in the decoder scheme to each computing node (or microprocessor) of the cluster system for the processing of signals, in parallel. To run multimedia applications in this cluster system, an efficient real-time video processing is implemented.
15850495
Automatic Summarization for Financial News Delivery on Mobile Devices
Christopher C. C. Yang and Fu Lee Wang Department of Systems Engineering and Engineering Management The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China {yang, flwang}@se.cuhk.edu.hk ABSTRACT Wireless access with mobile devices is a promising addition to the WWW and traditional electronic business. Mobile devices provide convenience and portable access to the huge information space on the Internet. It is desire to access the most updated financial information through mobile devices in order to make critical and urgent decision for most of the investors. In this paper, we present a financial news delivery system on mobile devices based on the fractal summarization model. Fractal summarization is developed based on the fractal theory. It generates a brief skeleton of summary at the first stage, and the details of the summary on different levels of the document are generated on demands of users. Such interactive summarization reduces the computation load in comparing with the generation of the entire summary in one batch by the traditional summarization, which is ideal for wireless access.
3116757
Intellectual Property Protection for Electronic Commerce Applications
Online content distribution businesses require methods to protect the intellectual property of distributed content. Intellectual property protection is a mechanism to protect the rights of ownership of original work so that no one can use the rights-protected work in any way without seeking permission for the use and, if necessary, paying the rights owners a royalty for the use. Digital watermarking is the core technology in electronic rights protection. However, research addressing the concerns of businesses about intellectual property protection schemes through watermarking is scarce. In this paper, we address these concerns by first introducing watermark design patterns (WDPs) for electronic commerce applications, then presenting problems of copyright protection using watermarking, and finally presenting management concerns. A WDP is defined as the requirements of a digital watermark for a particular type of distributed media content under the protection of its intellectual property. This paper introduces four WDPs for four types of media data - video, image, audio, and text and they are denoted as WDPvideo, WDPimage, WDPaudio and WDPtext respectively. The four WDPs are derived from the characteristics of watermarking techniques and the properties of a distributor’s web site. In our study, the proposed WDPs are used to relate the digital watermarking techniques to electronic commerce applications, and their relationships are presented graphically. The relationship diagram can facilitate electronic commerce application developers to select appropriate digital watermarking techniques and off-the-shelf systems for intellectual property protection on their web sites.