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61.
对《基于GIS技术的安徽省重大农业气象灾害测评系统》的总体设计方法作了概要介绍。该系统的建立主要是采用GIS技术,综合气候分析、遥感监测、地理环境影响评判等方法,提高对安徽省干旱、洪涝、低温冻害等重大农业气象灾害实时监测、趋势预测,以及对农业生产影响的分析评价结果的准确性。 相似文献
62.
Wireless ATM networks require efficient mobility management to cope with frequent mobile handoff and rerouting of connections. Although much attention has been given in the literature to network architecture design to support wide-area mobility in public ATM networks, little has been done to the important issue of user mobility estimation and prediction to improve the connection reliability and bandwidth efficiency of the underlying system architecture. This paper treats the problem by developing a hierarchical user mobility model that closely represents the movement behavior of a mobile user, and that, when used with appropriate pattern matching and Kalman filtering techniques, yields an accurate location prediction algorithm, HLP, or hierarchical location prediction, which provides necessary information for advance resource reservation and advance optimal route establishment in wireless ATM networks 相似文献
63.
Tian-Hua Liu 《Industrial Electronics, IEEE Transactions on》1995,42(1):17-24
This paper presents a new method to achieve a maximum torque for a single-phase induction motor. An AC adjustable capacitor using an electronic switch in parallel with a capacitor is proposed. The capacitor is short-circuited in a different period by an electronic switch during each cycle to vary the effective value of the AC capacitor. Two new optimization algorithms, which obtain a maximum starting torque by adjusting the effective capacitor, are proposed. No starting capacitor or centrifugal switch is used here. A theoretical analysis, and simulated and experimental results are presented in this paper 相似文献
64.
本文从无线电通信基本要素出发 ,阐述上行信号和下行信号的无线传播 ,得出上下行信号平衡链路方程 ,并以我国普遍使用的TACS系统和GSM系统为例 ,着重讨论了信号平衡与蜂窝小区设计之间的关系。 相似文献
65.
Chun Hu Ji Zhao Li G.P. Liu P. Worley E. White J. Kjar R. 《Electron Device Letters, IEEE》1995,16(2):61-63
The effects of the plasma etching process induced gate oxide damages on device's low frequency noise behavior are investigated on MOSFET's fabricated with different field plate perimeter to gate area ratio antennas. Abnormal 1/f noise spectrum with a shoulder centered in the frequency range of 100 and to 1 kHz was frequently observed in small geometry devices, and it is attributable to a nonuniform distribution of oxide traps induced by plasma etching process 相似文献
66.
以行波半导体光放大器速度方程为基础,采用传输矩阵方法,对锥形结构半导体光放大器的增益和饱和特性进行理论研究。讨论了不同锥形长度,不同结构时的增益和饱和特性差异。理论研究表明,锥形结构能改善半导体光放大器的偏振灵敏度。在同一锥度下,长锥形长度能提高饱和增益,降低偏振度。在进行半导体光放大器有源条结构设计时要综合考虑锥度及锥形长度的影响,以实现结构优化 。 相似文献
67.
68.
关于生物系统超微弱发光的实验研究 总被引:3,自引:0,他引:3
生物系统存在超微弱光子辐射现象。通过一系列实验研究,我们认为,这种光子辐射既有低水平化学发光的性质,又有受激辐射的性质,是受激的低水平化学发光。 相似文献
69.
Liu Y. Blostein S.D. 《IEEE transactions on information theory / Professional Technical Group on Information Theory》1992,38(1):177-182
Bayesian analysis is used to show that Wald's sequential probability ratio test with varying thresholds is optimal for the nonstationary situation, where the observed samples are independent but not identically distributed. Some important properties useful for the design of the test thresholds are discussed. Wald's lower bound, generalized to the nonstationary situation, is also presented. The results have important applications in situations where the observed signal is time-varying. such as in radar signal processing, image processing, and spread spectrum communications 相似文献
70.
Jiuqiang Liu 《Journal of Graph Theory》1994,18(2):195-204
A maximal independent set of a graph G is an independent set that is not contained properly in any other independent set of G. Let i(G) denote the number of maximal independent sets of G. Here, we prove two conjectures, suggested by P. Erdös, that the maximum number of maximal independent sets among all graphs of order n in a family Φ is o(3n/3) if Φ is either a family of connected graphs such that the largest value of maximum degrees among all graphs of order n in Φ is o(n) or a family of graphs such that the approaches infinity as n → ∞. 相似文献