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Many recent studies have convincingly demonstrated that network traffic exhibits a noticeable self-similar nature, which has a considerable impact on network performance, and most studies of optical burst switching (OBS) networks are under a fundamental assumption that full wavelength conversion is available throughout the network. In practice, however, economic and technical considerations are likely to dictate a more limited and sparse deployment of wavelength converters in the optical network. Therefore, we present a novel scheme for OBS networks, called logical cascaded private subnet (LCPN) with start wavelength assignment policy. We define the concept of canoe relative to cluster in self-similar traffic, and introduce a new device named payload segregator at the edge node as a gateway to the core node in OBS Networks. According to the changes in the edge node framework, we put forward the concept of cluster private subnet and canoe private subnet in the core node correspondingly. A new start wavelength assignment policy is proposed for the absence of (full) wavelength conversion capabilities in the core node of OBS Networks. The performance study indicates that, our new scheme is robust under self-similar traffic and wavelength continuity constraint. 相似文献
154.
V.J. Logeeswaran F.E.H. Tay M.L. Chan F.S. Chau Y.C. Liang 《Analog Integrated Circuits and Signal Processing》2003,37(1):17-33
In this paper, the response to the first harmonic component (2f) of the electrostatic force in single terminal driven electrostatic comb-drive and parallel-plate drive was used as a signal to extract device parameters, namely, the Q-factor and resonant frequency instead of the fundamental (1f) resonance response. It is shown that the difficulty in motional measurement due to electrical cross-talk (parasitics) using 1f measurement can be overcome with a higher signal-to-noise ratio of the 2f signal. Both atmospheric (low-Q) and reduced pressure environment were investigated using off-chip electronics and lock-in amplifier. The measurements were done on the electrostatic comb-drive and capacitive parallel plate sensing plates that form the two core modules of a yaw rate sensor (dual-axis resonator). The effects of AC and DC bias voltages on the measured response have been investigated. Experimental amplitude and phase response data have been analysed using the Lorentzian curve-fit, Resonance Curve Area (RCA) method, the half-power bandwidth method (3 dB) and the Nyquist plot for data fitting and determination of the Q-factor and resonance frequency. 相似文献
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目前,分布式电源架构被广泛用于通信和计算设备中,该电源架构经常采用板载电源(BMP)模块,在尽可能靠近负载点的地方进行电源变换. 相似文献
157.
基于极限平衡理论定量评价井壁稳定性 总被引:6,自引:2,他引:4
井壁稳定性的准确评价对优化井身结构、优选完井方式、提高固井质量、提高测井解释精度等具有极其重要的指导意义。井壁稳定归根结底是井周应力状态与地层岩石强度的平衡关系问题。基于极限平衡理论从受力与材料强度两方面出发,应用统一处理平衡方程与破坏准则,分析了井周的应力分布,得出在与原水平最大主应力方向夹角为90°和270°处,井壁最易坍塌;夹角为0°和180°处,井壁最易破裂。进而提出了井壁的坍塌评价系数Sc和破裂评价系数Sf,当Sc=1或Sf=1时,井壁处于极限平衡状态;当Sc>1、Sf>1时,井壁稳定,且值越大,井壁越稳定。井壁坍塌评价系数和破裂评价系数为评价井壁稳定性提供了定量指标。 相似文献
158.
脉冲电镀最佳参数之探索和优化 总被引:3,自引:0,他引:3
本文利用正交实验法对脉冲电镀各控制参数进行试验,对影响分散能力、镀层可靠性及外观质量的各种因素进行探讨,寻找影响外观质量的显著因子并加以控制,同时进一步优化脉冲电镀的工艺参数。 相似文献
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160.
A new integrated magnetic full wave DC/DC power converter that provides flexible transformer design by incorporating an independent output inductor winding is introduced. The transformer is implemented on a traditional three-leg magnetic core. The inductor winding can be separately designed to control the output current ripple. The cross-sectional area of the inductor core leg can be reduced dramatically. The operation and performance of the proposed circuit are verified on a 100 W prototype converter. 相似文献