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81.
The initial value problem arising in the recursive evaluation of a 2D polynomial at equispaced points is treated in detail; the results facilitate efficient implementation of Bose's recursive algorithm. The computational complexity is compared with that involved in a direct computation, and some general observations are made for an alternative scheme proposed by X. Nie and R. Unbehauen (1989)  相似文献   
82.
83.
On-body communications around the human torso are considered, using ultra-wideband transmissions. The velocity of the diffracted wave propagating around the body is extracted from frequency- domain spatial correlation analyses.  相似文献   
84.
Dual-threshold-voltage (VT) CMOS is an effective way to reduce leakage power in high-performance very-large-scale-integration circuits. In this paper, we explore the technology design space for dual-threshold-voltage transistor design in deep-sub-100-nm technology nodes. We propose a technique of achieving high-VT (HVT) devices using thicker gate-sidewall offset spacers to increase the channel length without increasing the printed-gate length. The effectiveness of all the dual-VT technology options-increasing channel doping, increasing gate length, and proposed technique of increasing spacer thickness-is analyzed at transistor and basic logic gate level. Results on 65-nm partially depleted silicon-on-insulator and double-gate technologies indicate that the proposed technique yields lower dynamic power consumption and lower performance penalty compared with longer gate length and high body-doping devices. Our proposed technique, however, incurs extra fabrication mask similar to achieving HVT by increasing body doping.  相似文献   
85.
In this paper, we address the problem of user-class based service differentiation in CDMA networks. Users are categorized into three classes who get differentiated services based on their expected quality of service (QoS) from the service provider and the price they are willing to pay. We adopt a game theoretic approach for allocating resources through a two-step process. During a service admission, resource distribution is determined for each class. Then, the resource allocated to each class is distributed among the active users in that class. We devise a utility function for the providers which considers the expected revenue and the probability of users leaving their service provider if they are not satisfied with the service. Our model demonstrates how power can be controlled in a CDMA network to differentiate the service quality. Also, we show the impact of admitting high paying users on other users. Mainak Chatterjee received his Ph.D. from the department of Computer Science and Engineering at The University of Texas at Arlington in 2002. Prior to that, he completed his B.Sc. with Physics (Hons) from the University of Calcutta in 1994 and M.E. in Electrical Communication Engineering from the Indian Institute of Science, Bangalore, in 1998. He is currently an Assistant Professor in the department of Electrical and Computer Engineering at the University of Central Florida. His research interests include economic issues in wireless networks, applied game theory, resource management and quality-of-service provisioning, ad hoc and sensor networks, CDMA data networking, and link layer protocols. He serves on the executive and technical program committee of several international conferences. Haitao Lin received the BE degree in radio engineering from Southeast University, Nanjing, China, in 1996, the MS degree in computer applications from the Beijing University of Posts and Telecommunications, Beijing, China, in 2000, and Ph.D. in Computer Science and Engineering from The University of Texas at Arlington in 2004. He is currently with Converged Multimedia Services System Engineering at Nortel, Richardson, Texas. His research interests include wireless network performance evaluation and enhancement, wireless link adaptation, wireless network resource management, and applied game theory. Sajal K. Das received B.S. degree in 1983 from Calcutta University, M.S. degree in 1984 from Indian Institute of Science, Bangalore, and Ph.D. degree in 1988 from University of Central Florida, Orlando, all in Computer Science. He is currently a Professor of Computer Science and Engineering and also the Founding Director of the Center for Research in Wireless Mobility and Networking (CReWMaN) at the University of Texas at Arlington (UTA). Prior to 1999, he was a professor of Computer Science at the University of North Texas (UNT), Denton where he founded the Center for Research in Wireless Computing (CReW) in 1997, and also served as the Director of the Center for Research in Parallel and Distributed Computing (CRPDC) during 1995–97. Dr. Das is a recipient of the UNT Student Association's Honor Professor Award in 1991 and 1997 for best teaching and scholarly research; UNT's Developing Scholars Award in 1996 for outstanding research; UTA's Outstanding Faculty Research Award in Computer Science in 2001 and 2003; and the UTA College of Engineering Research Excellence Award in 2003. He is also frequently invited as a keynote speaker at international conferences and symposia. Dr. Das' current research interests include mobile wireless communications, resource and mobility management in wireless networks, mobile and pervasive computing, wireless multimedia, ad hoc and sensor networks, mobile internet architectures and protocols, distributed and grid computing, performance modeling and simulation. He has published over 350 research papers in these areas in international journals and conferences, directed numerous industry and government funded projects, and holds five US patents in wireless mobile networks. He received four Best Paper Awards in the ACM MobiCom'99, ICOIN'01, ACM MSWiM'00, and ACM/IEEE PADS'97. He as the Editor in Chief of the Pervasive and Mobile Computing (PMC) journal and also as an Associate Editor of IEEE Transactions on Mobile Computing, ACM/Kluwer Wireless Networks, Parallel Processing Letters, Journal of Parallel, Distributed and Emerging Systems. He served as General Chair of IEEE WoWMoM'05, PerCom'04, IWDC'04, MASCOTS'02, ACM WoWMoM'00-02; General Vice Chair of IEEE PerCom'03, ACM MobiCom'00 and IEEE HiPC'00-01; Program Chair of IWDC'02, WoWMoM'98-99; TPC Vice Chair of ICPADS'02; and as TPC member of numerous IEEE and ACM conferences. He is Vice Chair of the IEEE Computer Society's TCPP and TCCC Executive Committees.  相似文献   
86.
In this paper, a profit-aware design metric is proposed to consider the overall merit of a design in terms of power and performance. A statistical design methodology is then developed to improve the economic merit of a design considering frequency binning and product price profile. A low-complexity sensitivity-based gate sizing algorithm is developed to improve economic gain of a design over its initial yield-optimized design. Finally, we present an integrated design methodology for simultaneous sizing and bin boundary determination to enhance profit under an area constraint. Experiments on a set of ISCAS'85 benchmarks show in average 19% improvement in profit for simultaneous sizing and bin boundary determination, considering both leakage power dissipation and delay bounds compared to a design initially optimized for 90% yield at iso-area in 70-nm bulk CMOS technology.  相似文献   
87.
Delay/disruption tolerant networks (DTNs) are potentially applicable in the challenged scenarios like post‐disaster environments. In such networks, data forwarding generally relies on the mutual cooperation of the nodes. However, in reality, despite the availability of necessary resources for data forwarding, a node could misbehave by dropping messages received from other nodes with whom it has no strong social ties. Such a node is called a socially selfish node, which would cause a poor delivery ratio in the network. In this paper, we aim to address the problem of multicast data forwarding in the presence of such selfish nodes, by means of efficient relay selection in DTNs. First, we define a realistic reputation model, in contrast to existing models, to define the socially selfish/misbehaving nodes in the network. Further, a game‐theoretic analysis is carried out that implies data forwarding cost is also an influential parameter in handling selfishness/misbehavior. Subsequently, the problem is formulated as a constrained optimization problem, which is NP hard. Therefore, a heuristic is proposed by combining the reputation of a node and the cost of message forwarding to appropriately identify relay nodes, thus improve the performance of the multicast message delivery in the network. We utilize a social metric, centrality to minimize the message forwarding cost in terms of the number of relay nodes. Finally, the comparative performance evaluation in ONE simulator with practical scenarios shows the superiority of the proposed scheme over the other prominent schemes.  相似文献   
88.
Wireless Personal Communications - The climate has changed absolutely in every area in just a few years as digitized, making high-speed internet service a significant need in the future. Future...  相似文献   
89.
In this paper, we propose two information-theoretic techniques for efficiently trading off the location update and paging costs associated with mobility management in wireless cellular networks. Previous approaches always attempt to accurately convey a mobile's movement sequence and hence cannot reduce the signaling cost below the entropy bound. Our proposed techniques, however, exploit the rate distortion theory to arbitrarily reduce the update cost at the expense of an increase in the corresponding paging overhead. To this end, we describe two location tracking algorithms based on spatial quantization and temporal quantization, which first quantize the movement sequence into a smaller set of codewords and then report a compressed representation of the codeword sequence. Although the spatial quantization algorithm clusters individual cells into registration areas, the more powerful temporal quantization algorithm groups sets of consecutive movement patterns. The quantizers themselves are adaptive and periodically reconfigure to accommodate changes in the mobile's movement pattern. Simulation study with synthetic and real movement traces for both single-system and multisystem cellular networks demonstrate that the proposed algorithms can reduce the mobile's update frequency to 3-4 updates/day with reasonable paging cost, low computational complexity, storage overhead, and codebook updates.  相似文献   
90.
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