用逻辑方法验证移动Ad Hoc网络协议

针对移动Ad Hoc网络节点移动和无线广播通信特征,引入移动算子和广播算子,扩展形式逻辑LS2,提出了建模和分析移动Ad Hoc网络安全系统的逻辑ELS2.ELS2把网络模型化为不同位置上执行程序的线程复合,把攻击者模型化为与协议参与方并发运行的线程.ELS2中提出网络迹概念,描述网络节点内部计算和外部交互,以及节点移...     

基于聚类非参数检验的动态停车需求分布特征

为了探索动态停车需求的分布特征,提出聚类非参数检验分析方法.该方法按照个体-组-类的顺序对多时段随机变量进行聚合,在各聚合阶段运用相应的非参数检验方法校核结果,在确保拟合精度的同时,采用相应的模型描述动态随机变量的分布特征.结合该方法的运用,从问题确定、数据调查、数据处理与分析以及分布特征的归纳总结等环节详细阐述了动态...     

食管支架径向支撑性能

针对目前编织型食道支架支撑性研究存在的问题,完成了支架几何模型及有限元模型的创建、材料模型的选取以及边界条件的设置,提出了基于有限元分析的食管支架径向支撑力计算方法,并对不同头数、不同丝径、不同导程支架的径向支撑力进行分析.分析结果显示:头数越多,径向支撑力越大;丝径越大,径向支撑力越大;导程越大,径向支撑力越小.支撑...     

浸没式膜生物反应器处理微污染水的工艺强化

对比了单独膜与膜生物反应器(MBR)对微污染原水的处理效果,并研究了投加氯化铵、葡萄糖和粉末活性炭等强化措施对MBR处理效果的影响。结果表明,单独膜工艺对CODMn和氨氮去除率只有16%和5%;而以粉末活性炭为生物载体的MBR工艺对CODMn和氨氮去除率提高到35.3%和44.5%;提高原水有机物浓度和氨氮浓度对CODMn和氨氮去除效率提高作用有限;更换10%的PAC后,提高了MBR对CODMn的去除效果,其去除效率可由原来的35.3%提高到50% 。     

无线传感器网络中基于时间分量的混合路由协议

在均匀分簇的基础上,分析了多簇群情况下单跳和多跳模型能量的有效性,给出了两种情况下计算最优簇首数目的算法.考虑到单一的路由模式会引起网络能耗不均衡,提出并改进了多簇群情况下利用时间分量的单跳和多跳相结合的混合模型.仿真结果表明,基于时间分量的混合通信模式在能量有效性和能耗均衡分配方面均优于单跳、多跳模式.     

基于Y型多针孔干涉仪的三维绝对坐标测量

提出一种利用Y型多针孔干涉仪测量三维绝对位置坐标的新方法.这种方法是通过提取多针孔板上各测量孔的相位信息进而计算出待测点绝对位置坐标的.文章详细介绍了该方法的测量原理,并通过理论分析给出了测量公式.通过计算机模拟实验的方法验证了该方法的可行性.与现有的点衍射干涉测量法相比,该方法不需要任何相移装置,对测量环境的要求低,...     

Evaluating the reliability of microsatellite genotyping from low-quality DNA templates with a polynomial distribution model

Molecular studies using trace DNA, such as from museum specimens, ancient or forensic samples and samples obtained noninvasively, often have a common problem of low quality of DNA templates. Amplification errors, such as allelic dropout and false allele, may arise during polymerase chain reaction (PCR) using such samples. A mathematical model which treats homozygotes and heterozygotes discriminately has been developed to measure sample quality and compute the confidence level of using multipletube approaches. We use plucked hair samples collected from 26 individual Sichuan snub-nosed monkeys (Rhinopithecus roxel- lana) to test the model. In this case, a confidence level of 99% can be achieved by three positive PCRs. If the sample quality is very poor and requires many PCR replicates, an alternative multiplestep genotyping method is recommended. This model enables researchers to optimize experimental protocols through pilot studies and obtain reliable genetic information using noninvasive sampling method.     

Entransy dissipation minimization for optimization of heat exchanger design

In this paper,by taking the water-water balanced counterflow heat exchanger as an example,the entransy dissipation theory is applied to optimizing the design of heat exchangers.Under certain conditions,the optimal duct aspect ratio is determined analytically.When the heat transfer area or the duct volume is fixed,analytical expressions of the optimal mass velocity and the minimal entransy dissipation rate are obtained.These results show that to reduce the irreversible dissipation in heat exchangers,the heat exchange area should be enlarged as much as possible,while the mass velocity should be reduced as low as possible.     

Operational properties and matrix representations of quantum measures

Denoted by M(A), QM(A) and SQM(A) the sets of all measures, quantum measures and subadditive quantum measures on a σ-algebra A, respectively. We observe that these sets are all positive cones in the real vector space F(A) of all real-valued functions on A and prove that M(A) is a face of SQM(A). It is proved that the product of m grade-1 measures is a grade-m measure. By combining a matrix M _μ to a quantum measure μ on the power set A _n of an n-element set X, it is proved that μ ≪ ν (resp. μ ⊥ ν) if and only if M _μ ≪ M _ν (resp. M _μ M _ν =0). Also, it is shown that two nontrivial measures μ and ν are mutually absolutely continuous if and only if μ·ν∈QM(A _n ). Moreover, the matrices corresponding to quantum measures are characterized. Finally, convergence of a sequence of quantum measures on A _n is introduced and discussed; especially, the Vitali-Hahn-Saks theorem for quantum measures is proved.     

Sufficient and necessary conditions of separability for bipartite pure states in infinite-dimensional systems

The PHC criterion and the realignment criterion for pure states in infinite-dimensional bipartite quantum systems are given. Furthermore, several equivalent conditions for pure states to be separable are generalized to infinite-dimensional systems.