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81.
在没有专业仪器,没有明确参照物的条件下,如何快速定位接收天线,搜索到卫星信号,是电视工程技术人员经常遇到的问题,本文就此问题提出了一个新的解决办法,即利用已知卫星的位置来定位其它卫星的位置。 相似文献
82.
This paper proposes a new approach for stabilizing a homogeneous solution in reaction–convection–diffusion system with oscillatory kinetics, in which moving or stationary patterns emerge in the absence of control. Specifically, we aim to suppress patterns by using a spatially weighted finite-dimensional feedback control that assures stability of the solution according to Lyapunov's direct method. A practical design procedure, based on spectral representation of the system and dissipative nature of parabolic PDEs, is presented. 相似文献
83.
文章概述了人类能源利用从柴薪、煤到石油、天然气的探索与转变历程,着重对天然气利用在解决城市燃料和空气污染、提高发电效率、推动分布式发电、生产合成氨和合成甲醇、推动燃料电池转向氢能经济时代等方面的优越性进行了阐述。 相似文献
84.
Evgenia Adamopoulou Konstantinos Demestichas Panagiotis Demestichas Michael Theologou 《International Journal of Communication Systems》2008,21(3):311-330
Cognitive radio systems dynamically reconfigure the algorithms and parameters they use, in order to adapt to the changing environment conditions. However, reaching proper reconfiguration decisions presupposes a way of knowing, with high enough assurance, the capabilities of the alternate configurations, especially in terms of achievable transmission capacity and coverage. The present paper addresses this problem, firstly, by specifying a complete process for extracting estimations of the capabilities of candidate configurations, in terms of transmission capacity and coverage, and, secondly, by enhancing these estimations with the employment of a machine learning technique. The technique is based on the use of Bayesian Networks, in conjunction with an effective learning and adaptation strategy, and aims at extracting and exploiting knowledge and experience, in order to reach robust (i.e. stable and reliable) estimations of the configurations' capabilities. Comprehensive results of the proposed method are presented, in order to validate its functionality. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
85.
Distributed active storage architectures are designed to offload user-level processing to the peripheral from the host servers.
In this paper, we report preliminary investigation on performance and fault recovery designs, as impacted by emerging storage
interconnect protocols and state-of-the-art storage devices. Empirical results obtained using validated device-level and interconnect
data demonstrate the significance of the said parameters on the overall system performance and reliability. 相似文献
86.
航空放射性遥感系统采用航空γ能谱仪,在空中飞行探测地表放射性,能够快速进行大面积环境放射性调查。结合已经开始进行的首次大面积航空放射性遥感调查工作,简要介绍了航空放射性遥感系统构成、核探测γ能谱测量和数据处理技术。对系统转换因子刻度和剥离系数刻度方法进行了讨论,并对初步应用情况进行了总结。 相似文献
87.
David P. Cormode Jason J. Davis Paul D. Beer 《Journal of Inorganic and Organometallic Polymers and Materials》2008,18(1):32-40
Disulfide and dithiocarbamate functionalized porphyrins have been synthesized and used as protecting ligands for gold nanoparticle
formation either via ligand substitution reactions or by direct synthesis. These nanoparticles have been shown to recognize
anions via changes in the absorbance spectrum of the surface adsorbed porphyrin moieties. Association constants, derived from
quantitative titrations, indicate a remarkable surface enhancement effect where the surface bound porphyrins bind anions much
more strongly than the free receptor in solution. 相似文献
88.
Xiangqing Tian Xiaoqiong Qi Qiongfang Ma Xiaoping Zhang 《Photonic Network Communications》2006,11(3):271-276
A new design scheme for a distributed algorithm for routing and wavelength assignment (RWA) is developed in this paper, and
the communication rules between the nodes to exchange signaling packets are discussed. The Adaptive-Alternate-Routing-Least-Load
(AARLL) algorithm is implemented in the distributed scheme for the first time. Under dynamic traffic circumstances, the influence
of the race condition, which does not exist in centralized scheme, on the network performance is analyzed and the analyzed
results show that the race condition has a major impact on network performance only under light traffic load, while under
medium and heavy traffic load the impact is very small. To analyze the performance loss caused by adopting the distributed
algorithm for RWA, the capacity loss factor (CLF) is introduced and the calculated results show that CLF does not exceed 6%
under medium traffic load. 相似文献
89.
90.
Summary This paper proposes a self-stabilizing protocol which circulates a token on a connected network in nondeterministic depth-first-search order, rooted at a special node. Starting with any initial state in which the network may have no token at all or more than one token, the protocol eventually makes the system stabilize in states having exactly one circulating token. With a slight modification to the protocol —by removing nondeterminism in the search — a depth-first-search tree on the network can be constructed. The proposed protocol runs on systems that allow parallel operations.
Shing-Tsaan Huang was born in Taiwan on September 4, 1949. He got his Ph.D. degree in 1985 from Department of Computer Science, University of Maryland at College Park. Before he pursued his Ph.D. degree, he had worked several years in the computer industry in Taiwan. Professor Huang is currently the chairman of the Department of Computer Science, Tsing Hua University, Taiwan, Republic of China. His research interests include interconnection networks, operating systems and distributed computing. He is a senior member of the IEEE Computer Society and a member of the Association for Computing Machinery.
Nian-Shing Chen was born in Taiwan on October 21, 1961. He received his Ph.D. degree in computer science from National Tsing Hua University in 1990. Dr. Chen is currently an associate professor with the Department of Information Management at Sun Yat-Sen University of Taiwan. His research interests include distributed systems, computer networks, computer viruses and expert systems. He is a member of IEEE and Phi Tau Phi honorary society.This research is supported by National Science Council of the Republic of China under the contract NSC81-0408-E-007-05 and NSC82-0408-E-007-027 相似文献