排序方式: 共有37条查询结果,搜索用时 15 毫秒
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在碱纤维素黄化过程,环境气温变化、黄化每批加入甲纤质量变化等,是影响黄化CS2量比波动的原因。提出了解决这些问题的措施。 相似文献
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A new method which employs compressive sensing (CS) to reconstruct the sparse spectrum is designed and experimentally demonstrated. On the basis of CS theory, the simulation results indicate that the probability of reconstruction is high when the step of the sparsity adaptive matching pursuit algorithm is confirmed as 1. Contrastive analysis for four kinds of commonly used measurement matrices:part Hadamard, Bernoulli, Toeplitz and Circular matrix, has been conducted. The results illustrate that the part Hadamard matrix has better performance of reconstruction than the other matrices. The experimental system of the spectral compression reconstruction is mainly based on the digital micro-mirror device (DMD). The experimental results prove that CS can reconstruct sparse spectrum well under the condition of 50% sampling rate. The system error 0.078 1 is obtained, which is defined by the average value of the 2-norm. Furthermore, the proposed method shows a dominant ability to discard redundancy. 相似文献
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针对现有的Fluid-Flow移动模型难以拟合PCS网络中随机游走行为的问题。设计一种基于Fluid-Flow和Gauss-Markov的混合模型。该模型应用Gauss-Markov随机过程理论,将速度离散化,确定前后速度关联度参数,从而能模拟不同运动特征的移动终端。通过Matlab数值仿真,模拟PCS网络应用场景,较单纯基于Fluid-Flow模型的位置管理方法能大幅度减小系统开销,证明该模型更适于复杂位置管理性能评估。 相似文献
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混合光波长转换在波分复用光网络中的应用 总被引:4,自引:2,他引:2
在全光网络中,如何合理利用波长转换来降低光网络的阻塞率是一个非常关键的问题。研究了最新的波长转换体系结构和波长转换手段,提出一种全新的混合波长转换方法,在减少网络中波长转换器个数的同时,维持拥塞概率类似于全波长转换。提出了5种不同的波长转换器使用策略,并利用数值模拟的方法,比较了这5种不同的波长转换器使用策略,分析结果,得出了最小化光网络的阻塞概率的波长转换使用策略。结合混合波长转换和波长转换器使用策略,进一步提出了光网络中优化波长转换器配置的遗传算法,通过对14个节点的美国自然科学基金网(NSF Net)的数值模拟,结果表明它是十分有效的,在减少光网络中波长转换器数量,且不增加光网络波长数量的情况下,基本保持原有网络性能。 相似文献
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波分复用波长路由节点的阻塞特性分析 总被引:4,自引:0,他引:4
利用概率统计理论的方法,从节点层次上定量分析了节点规模、复用波长数目以及波长转换对波分复用(WDM)波长路由网络中波长路由节点的影响。提出了基于概率统计的节点阻塞模型。数值结果突出表明波长转换能力越强的全光节点,其性能越优。为了提高网络资源的使用效率并增强全光网络的灵活性,必须实现全光网络中的虚波长路由波长转换器。通过数值计算找到了阻塞性能和代价的折中,研究中发现配置较低波长转换能力波长转换器的波长路由节点将会具备更强的性价比优势,当前在构建光通信系统时使用弱波长转换能力的光节点更可行。 相似文献
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Nano transparent conducting titanium-zinc oxide (Ti-ZnO) thin films were prepared on glass substrates by radio frequency (RF) magnetron sputtering technique. The deposited films are characterized by X-ray diffraction (XRD), four-probe meter and UV-visible spectrophotometer. The effects of Ti-doping content on the structural, optical and electrical properties of the films are investigated. The XRD results show that the obtained films are polycrystalline with a hexagonal wurtzite structure and preferentially oriented in the (002) crystallographic direction. The structural and optoelectronic characteristics of the deposited films are subjected to the Ti-doping content. The Ti-ZnO sample fabricated with the Ti-doping content of 3% (weight percentage) possesses the best crystallinity and optoelectronic performance, with the highest degree of preferred (002) orientation of 99.87%, the largest crystallite size of 83.2 nm, the minimum lattice strain of 6.263´10-4, the highest average visible transmittance of 88.8%, the lowest resistivity of 1.18×10-3 W?cm and the maximum figure of merit (FOM) of 7.08×103 W-1?cm-1. Furthermore, the optical bandgaps of the films are evaluated by extrapolation method and observed to be an increasing tendency with the increase of the Ti-doping content. 相似文献
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通过对主叫号码的话单进行通话时长、通话次数、用户移动性和通话时间冲突等克隆特征匹配的扫描分析,识别出可疑的移动电话克隆用户。设计了不同被叫号码类型的通话累计时间和次数分析算法、用户移动速度分析算法和主叫通话时间冲突分析算法。以话单分析算法为核心实现移动电话反克隆分析处理系统。系统实际应用表明采用话单分析算法识别可疑克隆对象具有较高的准确性和可靠性,从而为运营商提供了一种更加灵活的反克隆技术手段。 相似文献
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