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71.
Because of package, a single FBG has dual Bragg wavelength. One is sensitive to stress and the other is sensitive to temperature. By using the special mechanism, the wavelengths can be tuned by stress and temperature respectively. 相似文献
72.
Huayi Wu Xiaohua Jia Yanxiang He Chuanhe Huang 《International Journal of Communication Systems》2005,18(9):803-816
This paper investigates the issues of QoS routing in CDMA/TDMA ad hoc networks. Since the available bandwidth is very limited in ad hoc networks, a QoS request between two nodes will be blocked if there does not exist a path that can meet the QoS requirements, even though there is enough free bandwidth in the whole system. In this paper, we propose a new scheme of using multiple paths between two nodes as the route for a QoS call. The aggregate bandwidth of the multiple paths can meet the bandwidth requirement of the call and the delays of these paths are within the required bound of the call. We also propose three strategies by which to choose a set of paths as the route, namely, shortest path first (SPF), largest bandwidth first (LBF), and largest hop‐bandwidth first (LHBF). Extensive simulations have been conducted to evaluate the performance of the three strategies in comparison with a traditional single path routing algorithm. The simulation results show that the proposed multiple paths routing scheme significantly reduces the system blocking rates in various network environments, especially when the network load is heavy. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
73.
A facile, rapid and regioselective method for the 1-O-deacylation of peracylated glycopyranoses is described which occurs under mild conditions by absorption onto alumina using microwave irradiation. 相似文献
74.
75.
我国电信企业要做大做强,信息化是必然的战略选择和有效的助力器。本文阐述了电信企业信息化的含义、现状,描绘了电信企业信息化的目标,从经济学、管理学、行为科学等学科的角度提出了我国电信企业信息化策略。 相似文献
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78.
用光栅衍射法测试液体表面张力 总被引:1,自引:0,他引:1
利用π型直线状振源,在待测液面产生正弦形表面驻波,将其作为一种理想的反射式光栅,通过对激光束的衍射,形成线阵衍射光斑.借助LCCD等硬件测试系统及相应的数据采集与处理系统,实时准确地测量液体表面张力。 相似文献
79.
Dashan Huang Yoshitaka Kai Frank J. Fabozzi Masao Fukushima 《European Journal of Operational Research》2007
This paper presents a model for optimally designing a collateralized mortgage obligation (CMO) with a planned amortization class (PAC)-companion structure using dynamic cash reserve. In this structure, the mortgage pool’s cash flow is allocated by rule to the two bond classes such that PAC bondholders receive substantial prepayment protection, that protection being provided by the companion bondholders. The structure we propose provides greater protection to the PAC bondholders than current structures during periods of rising interest rates when this class of bondholders faces greater extension risk. We do so by allowing a portion of the cash flow from the collateral to be reserved to meet the PAC’s scheduled cash flow in subsequent periods. The greater protection is provided by the companion bondholders exposure to interest loss. To tackle this problem, we transform the problem of designing the optimal PAC-companion structure into a standard stochastic linear programming problem which can be solved efficiently. Moreover, we present an extended model by considering the quality of the companion bond and by relaxing the PAC bondholder shortfall constraint. Based on numerical experiments through Monte Carlo simulation, we show the utility of the proposed model. 相似文献
80.
随着深亚微米集成电路技术的发展,集成电路的规模越来越大,工作频率越来越高,并正朝着系统集成的方向发展,因而在模拟速度,模拟精度和可模拟的电路规模等各个方面对电路仿真技术提出了新的要求。近年来,各种新的电路仿真方法和仿真系统用相继脱颖百出,并将取代那些传统的,已经无法适应深亚微米技术发展的电路仿真器。 相似文献