State observability and condition observability for a class of interacting discrete event systems

This paper introduces the concepts of state observability and condition observability for condition systems, a class of systems composed of discrete state components which interact via discrete binary signals called conditions. Given a set of externally observed conditions, state observability implies that the state of the system can be determined from the observations, and condition observability implies that all unobserved input and output conditions of the system can be determined from the observations. In this paper, we present a class of systems which is state observable and condition observable. We present a method to synthesize an observer system to provide state and condition signal estimates for a single component subsystem.     

Holmium-doped Porous Silicon Prepared by a New Electrochemical Approach and Its Photoluminescence

Ｐｏｒｏｕｓｓｉｌｉｃｏｎ（ＰＳ）ｗａｓｆｏｕｎｄｔｏｅｍｉｔｖｉｓｉｂｌｅｌｕｍｉｎｅｓｃｅｎｃｅａｔｒｏｏｍｔｅｍｐｅｒａｔｕｒｅｂｙＣａｎｈａｍｉｎ１９９０［１］．Ｔｈｉｓｐｈｅｎｏｍｅｎｏｎｉｍｐｌｉｅｄａｐｏｔｅｎｔｉａｌａｐｐｌｉｃａｔｉ...     

诱导结晶条件下硅酸盐水泥熟料形成动力学的研究

根据诱导结晶的原理，我们提出了用已烧好的同类优质熟料作为晶种，诱导水泥烧成过程中的矿物形成。用掺与不掺对比的方法，利用现代物理、化学手段进行了研究。结果表明：明显提高了生料的易烧性；使ｆ－ＣａＯ明显下降；水泥熟料形成的活化能降低；刚分解的ＣａＯ在晶种表面富集；加快了各个阶段的固相反应；加快了熟料矿物形民；熟料矿物质量有所提高；并使ｆ－ＣａＯ的结构特征上发生了易于消解的变化。     

机车紧急制动装置使用中的几个问题

针对机车紧急制动装置使用中出现的问题进行了分析，并提出了几点解决问题的方法，对今后紧急制动装置的设计和使用具有一定的参考价值。     

A simple method for determining the Weibull estimator

Abstracts are not published in this journal This revised version was published online in November 2006 with corrections to the Cover Date.     

Ill-conditioned performance functions of queueing systems

Shows that for queueing networks with deterministic or discrete service time distributions, the performance functions can be nondifferentiable at a dense subset of a given interval. The authors also show that when the service time densities are supported on small intervals, the performance function derivatives changes rapidly. The authors prove these results for a two-server cyclic network and then point out a potential generality to other queueing networks. The results indicate that the nonsmooth analysis may be useful in the area of stochastic discrete-event systems     

松材线虫病害高光谱时序与敏感特征研究

采用高光谱仪ASD FieldSpec Pro FR,连续观测了健康和发病马尾松针叶的时序高光谱,分析了松材线虫病害光谱的时序特征、敏感时期和敏感特征。结果表明:与健康马尾松相比,病害马尾松时序光谱差异较大;病害首先造成红边区域内光谱反射率减低,然后再出现红边蓝移的2阶段光谱变化规律;感染松材线虫的马尾松9月初已经出现了病态植被典型的光谱特征;近红外平台内最大的一阶微分值、红边内一阶微分的总和(SDr)与蓝边内一阶微分的总和(SDb)的比值等是指示病害发生的显著性高光谱特征。     

基于AHP的樱园农家乐SWOT分析及发展对策

利用AHP和SWOT分析理论,提出了西安樱园观光旅游农家乐的发展策略.根据实地调研,探讨了樱园农家乐发展所面临的优势、劣势、机遇和威胁,建立了总体层次分析评价指标体系,确定了各层次的指标权重,分析了四种备选的优化方案.最后建议,樱园农家乐的发展应充分发挥“体验参与模式”的优势,把握政府引导和政策支持的机遇.     

Closed‐loop control for self‐calibration of accelerometer achieved through integrated sensor and actuator system

Microsystem Technologies - In-situ self-calibration can fundamentally solve the problem of long-term stability of the accelerometer. The implementation of external integrated micro structure to...     

基于星敏感器的姿态优化估计算法

对于采用星敏感器的航天器姿态确定问题,提出了一种快速的姿态优化估计方法;首先,根据Rodrigues参数和观测向量之间的线性关系,引入四元数,构造了不同的非奇异的优化准则;其次,借助四元数,求解了基于该准则的姿态优化算法;误差协方差分析和数值仿真结果表明,该算法与著名的QUaternion ESTmation(QUEST)算法相比,在相同的操作系统环境下,具有相同的姿态估计精度,但计算速度更快,对两种算法选取间隔为2000次的仿真步长,统计数据长度为100个采样点,最后对结果加权求平均值,统计结果显示仅为QUEST的三分之一;这种姿态优化估计方法具有一定的工程应用价值。