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41.
42.
Bharadwaj Veeravalli Long Chen Hun Yen Kwoon Goh Kar Whee See Ying Lai Lim Peng Hian Ho Chin Chow 《Multimedia Tools and Applications》2006,28(1):89-118
The problem of employing multiple servers to serve a pool of clients on a network based multimedia service is addressed. We
have designed and practically implemented a prototype system employing multiple servers to render a long duration movie to
the customers. We have employed a multiple server retrieval strategy proposed in the literature [39] to realize this system.
In the system, server coordination, client behavior and service facilities are completely controlled by an Agent based approach
in which we have used the recent Jini technology. Several issues, ranging from data retrieval from individual server, behavior
of the underlying network infrastructure, to client management and resource (client buffers) management, are considered in
this implementation. We describe in detail our experiences in this complete design process of every module in the software
architecture, its purpose, and working style. Further, the system is shown to be robust amidst unpredictable failures, i.e.,
in the event of server crashes. The load balancing capability is built-in as a safe guard measure to assure a continuous presentation.
We present a comprehensive discussion on the software architecture to realize this working system and present our experiences.
A system comprising a series of Pentium III PCs on a fast Ethernet network is built as a test-bed. Through this prototype,
a wider scope of research challenges ahead are highlighted as possible extensions.
Bharadwaj Veeravalli Member, IEEE & IEEE-CS, received his BSc in Physics, from Madurai-Kamaraj Uiversity, India in 1987, Master's in Electrical
Communication Engineering from Indian Institute of Science, Bangalore, India in 1991 and PhD from Department of Aerospace
Engineering, Indian Institute of Science, Bangalore, India in 1994. He did his post-doctoral research in the Department of
Computer Science, Concordia University, Montreal, Canada, in 1996. He is currently with the Department of Electrical and Computer
Engineering, Computer and Information Engineering (CIE) division, at The National University of Singapore, Singapore, as a
tenured Associate Professor. His main stream research interests include, Multiprocessor systems, Cluster/Grid computing, Scheduling
in parallel and distributed systems, Bioinformatics & Computational Biology, and Multimedia computing. He is one of the earliest
researchers in the field of divisible load theory. He has published over 75 papers in high-quality International Journals
and Conferences. He had secured several externally funded projects. He has co-authored three research monographs in the areas
of Parallel and Distributed Systems, Distributed Databases, and Multimedia systems, in the years 1996, 2003, and 2005, respectively.
He had guest edited a special issue on Cluster/Grid Computing for IJCA, USA journal in 2004. He has been recently invited
to contribute to Multimedia Encyclopedia, Kluwer Academic Publishers, 2005. He is currently serving the Editorial Board of
IEEE Transactions on Computers, IEEE Transactions on SMC-A and International Journal of Computers & Applications, USA, as an Associate Editor. He had served as a program committee member and as a session chair in several International Conferences.
Long Chen received the B.E. degree in Electrical Engineering and M.E. degree in Electrical Engineering from the Northwestern Polytechnic
University, P. R. China, in 1998 and 2001, respectively, and the M.E. degree in Computer Engineering from the National University
of Singapore, Singapore, in 2004. He is currently a Ph.D. candidate at the Department of Electrical and Computer Engineering,
the University of Delaware, United States. His research interests include multimedia systems, distributed system, network
security, and computer architecture. 相似文献
43.
Resolution enhanced light field near eye display using e‐shifting method with birefringent plate 下载免费PDF全文
Jui‐Yi Wu Ping‐Yen Chou Kuei‐En Peng Yi‐Pai Huang Hsin‐Hsiang Lo Chuan‐Chung Chang Fu‐Ming Chuang 《Journal of the Society for Information Display》2018,26(5):269-279
Light field near eye displays (LFNED) can produce lightweight devices and address the accommodation–convergence conflict. However, low spatial resolution creates a poor immersive experience in LFNED. In addition, although many e‐shifting devices have been proposed to enhance resolution in projection system, yet those devices are too bulky to be applied in an LFNED to keep it lightweight. In this paper, a compact e‐shifting component is proposed to enhance image resolution in an LFNED by using a birefringent plate and twisted nematic switch cell. The proposed e‐shifting device is a flat and thin component with only 2.6 mm of thickness, which could be placed in the gap of an LFNED without increasing the thickness. The results show that the proposed components could be easily integrated in an LFNED with the result of resolution enhancement. 相似文献
44.
Sung Kim Bastani F.B. I-Ling Yen Chen I.-R. 《IEEE transactions on pattern analysis and machine intelligence》2004,30(4):218-230
Dramatic advances in computer and communication technologies have made it economically feasible to extend the use of embedded computer systems to more and more critical applications. At the same time, these embedded computer systems are becoming more complex and distributed. As the bulk of the complex application-specific logic of these systems is realized by software, the need for certifying software systems has grown substantially. While relatively mature techniques exist for certifying hardware systems, methods of rigorously certifying software systems are still being actively researched. Possible certification methods for embedded software systems range from formal verification to statistical testing. These methods have different strengths and weaknesses and can be used to complement each other. One potentially useful approach is to decompose the specification into distinct aspects that can be independently certified using the method that is most effective for it. Even though substantial-research has been carried out to reduce the complexity of the software system through decomposition, one major hurdle is the need to certify the overall system on the basis of the aspect properties. One way to address this issue is to focus on architectures in which the aspects are relatively independent of each other. However, complex embedded systems are typically comprised of multiple architectures. We present an alternative approach based on the use of application-oriented-frameworks for implementing embedded systems. We show that it is possible to design such frameworks for embedded applications and derive expressions for determining the system reliability from the reliabilities of the framework and the aspects. The method is illustrated using a distributed multimedia collaboration system. 相似文献
45.
Hong-Hsu Yen Steven S. W. Lee Florence G. H. Yap 《The Journal of supercomputing》2012,62(3):1119-1138
Multicast routing in wireless networks that possess the wireless multicast advantage could significantly reduce the power and energy consumption. However, this kind of multicast routing that only addresses the transmission radius coverage might not be able to meet the bandwidth requirement of the users. As a result, additional transmissions are required to incur more energy consumption and carbon dioxide emissions that make existing algorithms not applicable to bandwidth constrained applications. In this paper, for the first time, we address the bandwidth aware minimum power multicast routing problem in wireless networks where the objective function is to minimize the total power consumption subject to the users?? bandwidth requirements. This problem is a challenging cross-layer design problem that requires seamless and sophisticated integrated design in the network layer (multicast routing) and physical layer (bandwidth-aware wireless transmission and power control). We first formulate this problem as a mixed integer linear programming problem and then propose a Lagrangian relaxation based algorithm to solve this problem. Numerical results demonstrate that the proposed approach is a sound green networking algorithm that outperforms the existing power efficient multicast routing approaches under all tested cases, especially in large bandwidth request, fine radius granularity, large group size and sparse network. 相似文献
46.
煤矿生产能力核定工作是当前煤炭行业一项重要的工作。通过对煤矿生产能力核定工作中存在的问题和不足之处提出针对性对策,为煤矿生产能力核定工作更好的开展、标准的更加完善提供科学依据。 相似文献
47.
Chen T.-M. Chiu Y.-M. Wang C.-C. Chan K.-U. Lin Y.-H. Huang M.-C. Lu C.-H. Wang W.-S. Hu C.-S. Lee C.-C. Huang J.-Z. Chang B.-I. Yen S.-C. Lin Y.-Y. 《Solid-State Circuits, IEEE Journal of》2007,42(5):983-991
A low-power fullband 802.11a/b/g WLAN transceiver in 0.15-mum CMOS technology is described. The zero-IF transceiver achieves a receiver noise figure of 4.4/4 dB for the 2.4-GHz/5-GHz bands, respectively. The corresponding sensitivity at 54-Mb/s operation is -72 dBm for 802.11g and -74 dBm for 802.11a using actual PER measurement. An on-chip PA delivers 20 dBm output P1-dB. A new I/Q compensation scheme is implemented in local oscillator (LO) and an image rejection of better than 52 dB is observed. The transmitter delivers 10/1.5 dBm (2.4-/5-GHz) EVM-compliant output power for a 64-QAM OFDM signal at 54-Mb/s. The power consumption is 117/135 mW (1.8-V) in the receive mode and 570/233.1 mW in the transmit mode for 2.4/5 GHz, respectively. The low power consumption, high integration and robustness (-40 to 140degC) make this transceiver suitable for portable applications 相似文献
48.
It is well known that higher dimensional information essentially leads to better accuracy in remotely sensed image classification. This paper is aimed at land cover classification from SPOT-HRV imagery by the integration of multispectral intensity and texture information. In particular, fractal dimensions are extracted using a wavelet transform as image texture. A neural network approach to classification is adopted in this paper. The underlying network is a modified multilayer perceptron trained by a Kalman filtering technique. The main advantages of this network are (1) its non-backpropagation fashion of learning which leads to a fast convergence, (2) a built-in optimization function, and (3) global scale. Saving computer storage space and a fast learning capability are in particular suitable features for remote sensing applications. Correlation analysis was subsequently performed on both the intensity and fractal images. It was found that fractal information significantly improves the discrimination capability of heterogeneous area such as in urban regions, while it slightly degrades accuracy for homogeneous areas, such as open water. The overall classification performance is superior to results obtained using reflectance only. Improvements over heterogeneous areas are demonstrated. 相似文献
49.
Fr��d��ric Chardard Fr��d��ric Dias Hai Yen Nguyen Jean-Marc Vanden-Broeck 《Journal of Engineering Mathematics》2011,70(1-3):175-189
Free-surface flows past submerged obstacles in a channel are considered. The fluid is assumed to be inviscid and incompressible and the flow to be irrotational. The first-order approximation of long nonlinear surface waves over one or two bumps results in a forced Korteweg?Cde Vries (fKdV) equation. Solutions of the stationary fKdV equation are constructed and their stability is studied, either analytically or numerically. These various solutions include solitary waves over a single bump, solitary waves with two humps over a double bump, table-top solutions over a double bump and fronts. 相似文献
50.
The flexural response of 3D woven textile composite panels containing an edge crack is evaluated using the End Notch Flexure (ENF) test. In doing so, the effectiveness of 3D reinforcement in increasing and/or eliminating delamination is demonstrated. A finite element model of the ENF configuration using the Discrete Cohesive Zone Model (DCZM) was used to evaluate the deformation response and fracture properties corresponding to the experimental results presented in Pankow et al. (2011) [1]. A modified trapezoidal traction law was used in the DCZM to computationally evaluate the ENF test results. Good agreement between experimental results and predictions are reported, up to the point at which the crack reaches under the loading roller and damage begins to occur locally under the roller. 相似文献