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In this paper,we regard the nonlinear feedback shift register(NLFSR) as a special Boolean network,and use semi-tensor product of matrices and matrix expression of logic to convert the dynamic equations of NLFSR into an equivalent algebraic equation. Based on them,we propose some novel and generalized techniques to study NLFSR. First,a general method is presented to solve an open problem of how to obtain the properties(the number of fixed points and the cycles with different lengths) of the state sequences produced by a given NLFSR,i.e.,the analysis of a given NLFSR. We then show how to construct all 2^2^n-(l-n)/2^2^n-lshortest n-stage feedback shift registers(nFSR) and at least 2^2^n-(l-n)-1/2^2^n-l-1shortest n-stage nonlinear feedback shift registers(nNLFSR) which can output a given nonperiodic/periodic sequence with length l. Besides,we propose two novel cycles joining algorithms for the construction of full-length nNLFSR. Finally,two algorithms are presented to construct 2^2^n-2-1different full-length nNLFSRs,respectively. 相似文献
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针对云环境下自动信任协商过程中存在的协商效率低、敏感信息泄露等问题,提出一种基于资源分离的自动信任协商模型( Resource Separation Based ATN in Cloud )CRSBATN。该模型利用云环境分离资源拥有者和资源,使访问者不能直接与拥有者建立关系,只有能解密访问控制策略的访问者才能获得拥有者的信息,从而可以过滤大部分不符合策略的访问者,减少大量非必要的计算开销;提出使用ABS-OSBE算法对资源访问者的属性真实性进行一致性校验,并给出自动信任协商模型框架和协商策略形式化描述,最后实验结果表明该模型能够降低协商开销,提升隐私保护能力。 相似文献
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TiB_2陶瓷覆层的磨料磨损性能研究 总被引:1,自引:0,他引:1
在40Cr钢表面制备含TiB2相的覆层以提高该钢的耐磨性。分析了四种不同制备工艺及三种后续热处理工艺所获得的显微组织和物相。重点进行了磨料磨损实验。结果表明:采用表面改性新工艺可以获得表层为TiB2的陶瓷覆层。其中采用A1B2工艺制备的覆层经正火处理后,其耐磨性能最好。对磨损机理的分析表明:TiB2覆层在磨损过程中属于软磨料磨损,改变了磨损状态,提高了材料的耐磨性 相似文献
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Stepped frequency radar is a well known scheme to generate high range resolution profile (HRRP) of targets. Through appropriate
radar parameter design, the radar enables both unambiguous velocity measurement and high resolution ranging within a single
dwell in a high pulse repetition frequency (HPRF) mode. This paper analyzes in detail the design principle of the HPRF stepped
frequency radar system, the solution to its ambiguity issue, as well as its signal processing method. Both theoretical analysis
and simulation results demonstrate that the proposed radar scheme can work independently to solve the problem of motion compensation,
and is therefore highly applicable to many new types of radar.
Supported by the fund of National Defense Industry Innovative Team 相似文献
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Microwave dielectric properties and microstructures of (Mg0.95Co0.05)TiO3 ceramics prepared by a new sintering method (reaction-sintering method) were investigated. A pure phase of (Mg0.95Co0.05)TiO3 was obtained by the new method and excellent dielectric properties were observed due to uniformities of the microstructure and the phase. In contrast, the secondary phase (Mg0.95Co0.05)Ti2O5 was observed in samples prepared by conventional sintering method. In order to study the influence of secondary phase on the microwave dielectric properties quantitatively, the weight fraction of (Mg0.95Co0.05)Ti2O5 was calculated on the basis of Rietveld refinement. The pore-free?r values of specimens prepared by two different methods indicated that porosity plays an important role in the ?r values of (Mg0.95Co0.05)TiO3 ceramics. Specimens sintered by reaction-sintering method at 1350 °C for 4 h possess excellent dielectric properties with an ?r of 16.3, a Q × f value of 244,500 GHz, and a τf value of −53.5 ppm/°C. 相似文献
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本文概述了IP监测的创新性,分析了IP监测的技术构成和系统优点,并对IP监测未来的发展方向进行了评述。 相似文献
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基于新的威布尔分布参数估计法的设备寿命可靠性分析 总被引:7,自引:2,他引:5
针对机械设备寿命可靠性分析中模型的精度问题,提出一种联合最小二乘及平均秩次估计威布尔分布参数的新方法.常用的参数估计法人为因素影响大,精度差,而且在现场使用不便.文中提出的方法有效地解决了上述问题.在采用最小二乘法对威布尔分布进行参数估计时,经验分布函数是确定寿命模型的基准,它的精度直接影响寿命模型的精度.平均秩次法根据故障样本和中止样本估计出所有可能的秩次,求出平均秩次,代入近似中位秩公式,得到经验分布函数,有效提高参数的精度.选取30台发动机,对其进行寿命可靠性分析,结果表明,该方法具有很高的准确性和实用性. 相似文献
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Wang Kun Ju DongYing Xu GuiYing Han BeiBei Chai MaoRong Wang YingXin Li LiXiang Zhang XueHu Ucida Masaya Zhou WeiMin 《中国科学:技术科学(英文版)》2020,63(12):2709-2716
Science China Technological Sciences - Organosilicon modified reduced graphene oxide (MrGO) has been fabricated by direct organosilicon modification of graphene oxide (GO). Interestingly, it is... 相似文献