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In this paper we study the optimization issues of ring networks employing novel parallel multi‐granularity hierarchical optical add‐drop multiplexers (OADMs). In particular, we attempt to minimize the number of control elements for the off‐line case. We present an integer linear programming formulation to obtain the lower bound in optimization, and propose an efficient heuristic algorithm called global bandwidth resource assignment that is suitable for the design of large‐scale OADM networks. 相似文献
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Waveband switching (WBS) is a promising technique to reduce the switching and transmission costs in the optical domain of a wavelength-division multiplexing (WDM) network. This paper considers the problem of provisioning dynamic traffic using WBS in a WDM mesh network. The network of interest is a homogeneous WBS network, where each node has the functionality of WBS. The problem is called the dynamic WBS problem, which involves searching waveband-routes or wavelength-routes for the dynamically arriving traffic requests. The objective is to minimize the total switching and transmission costs in the optical domain. To solve the dynamic WBS problem, an auxiliary graph model capturing the network state is proposed. Based on the auxiliary graph, two heuristic on-line WBS algorithms with different waveband grouping policies are proposed, namely the wavelength-first WBS algorithm based on the auxiliary graph (WFAUG) and the waveband-first WBS algorithm based on the auxiliary graph (BFAUG). Simulation results indicate that WBS is an attractive technique which reduces the overall switching and transmission costs by up to 30% in the network. The results also show that the WFAUG algorithm outperforms the BFAUG algorithm in terms of port savings and cost savings. 相似文献
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非接触红外辐射测温具有响应速度快、准确、便捷等优势。为实现中低温(50~400℃)物体温度的精确测量,根据双波段比色测温原理,搭建了双波段比色测温试验系统。首先对试验系统所用的试验器件进行精确标定,得到拟合曲线,用多种插值算法对曲线进行校正。然后,用设定温度的面源黑体作为试验目标来进行试验温度数据采集。实验结果表明:搭建的双波段试验系统不需要知道目标发射率,也能较为精确地得到中低温物体的真实温度。当系统标定置信度为0.95 时,物体的标准偏差在3℃以内。验证了搭建测温系统的正确性,实验装置的搭建对中低温物体真实温度的精确测量具有重要的研究意义。 相似文献
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结合大型剧院火灾自动报警系统工程设计实例,分析、比较剧院入口大厅、观众厅及舞台区域高大空间火灾探测器的选择,阐述在高大开放式空间建筑中怎样合理地选择火灾探测器。 相似文献
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基于液晶可调滤波器(LCTF)和CMOS组合的多光谱成像系统,在435~720nm波段范围内,以每隔5nm波段对小白菜叶片进行灰度值信息的提取,然后求出各个波段的灰度值平均值、标准差以及相关系数,并采用自适应波段选择法(ABS)提取出小白菜叶片的波段指数,最后通过波段指数的排序选取出小白菜叶片的有效特征波段。实验结果表明,用ABS的特征波段提取的算法,能够快速有效地获取小白菜叶片的光谱信息,在445nm、450nm、455nm、680nm、685nm、690nm、695nm和710nm波段具有较理想的波段指数值,有较大的光谱信息量。因此,这些波段可以很好地作为识别小白菜叶片的有效特征信息波段。 相似文献
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R. M. Biefeld A. A. Allerman S. R. Kurtz J. H. Burkhart 《Journal of Electronic Materials》1997,26(10):1225-1230
We describe the metalorganic chemical vapor deposition of InAsSb/InAsP strained-layer superlattice (SLS) active regions for
use in mid-infrared emitters. These SLSs were grown at 500°C, and 200 Torr in a horizontal quartz reactor using TMIn, TESb,
AsH3, and PH3. By changing the layer thickness and composition, we have prepared structures with low temperature (≤20K) photoluminescence
wavelengths ranging from 3.2 to 4.4 μm. Excellent performance was observed for a SLS light emitting diode (LED) and both optically
pumped and electrically injected SLS lasers. An optically pumped, double heterostructure laser emitted at 3.86 μm with a maximum
operating temperature of 240K and a characteristic temperature of 33K. We have also made electrically injected lasers and
LEDs utilizing a GaAsSb/InAs semi-metal injection scheme. The semi-metal injected, broadband LED emitted at 4 μm with 80 μW
of power at 300K and 200 mA average current. The InAsSb/InAsP SLS injection laser emitted at 3.6 μm at 120K. 相似文献
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基于作用距离的红外探测系统工作波段选择方法 总被引:2,自引:2,他引:0
选择合适的工作波段对获得性能优越的红外探测系统具有十分重要的意义.通过对红外探测系统与高光谱遥感工作波段的选择原则进行比较,从探测原理出发,结合高光谱遥感类间可分性的波段选择思想,发展了一种基于作用距离的波段选择方法.仿真结果表明,这种方法是可行的,能有效地计算出符合要求的工作波段参数. 相似文献
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本论文主要对波带交换光网络中的保护机制进行了一定的研究,提出了基于波带通道的专用保护和共享保护机制和算法,其中在共享保护算法中考虑不同的策略提出了三种不同的算法,即只共享逐跳的保护波长通道的WSP算法,只共享嵌入到波带通道中的保护波长通道的BSP算法和能同时共享两者的BWSP算法。最后进行了相应的网络仿真,讨论并得出BWSP算法的性能是最优的。 相似文献
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