PEAK COVARIANCE STABILITY OF A RANDOM RICCATI EQUATION ARISING FROM KALMAN FILTERING WITH OBSERVATION LOSSES

We consider the stability of a random Riccati equation with a Markovian binary jump coefficient. More specifically, we are concerned with the boundedness of the solution of a random Riccati difference equation arising from Kalman filtering with measurement losses. A sufficient condition for the peak covariance stability is obtained which has a simpler form and is shown to be less conservative in some cases than a very recent result in existing literature. Furthermore, we show that a known sufficient condition is also necessary when the observability index equals one.     

东露天铁路专线采空区治理对策研究

针对东露天铁路专线所经过的采空区特点,分析了典型采空区上覆岩层的稳定性和上覆岩层移动形式,提出该地区采空区的治理措施。     

无缝线路稳定性探讨

从无缝线路稳定性研究意义、研究理论着手,分析探讨了影响稳定性的因素,提出提高无缝线路稳定性的措施。     

一种由负定函数dV（x）／dt判定动态系统原点稳定性的方法

提出一种由负定导函数判定动态系统稳定性的方法，给出在已知导函数为负定的情况下系统稳定或者不稳定的充要条件，以及一组使用该方法的例子。     

Samples Selection for Artificial Neural Network Training in Preliminary Structural Design

An artificial neural network (ANN) is applied in the preliminary structural design of reticulated shells. Major efforts are made to enhance the generalization ability of networks through well-selected training samples. Number-theoretic methods (NTMs) are adopted to generate samples with low discrepancy, i.e.uniformly scattered in the domain, where discrepancy is a quantitative measurement of the uniformity. The discrepancy of the NTM-based sample set is 1/6-1/7 that of samples with equal spacing. In a case study,networks trained by NTM-based samples are compared with those trained by equal-spaced samples in generalizing performance. The results show that both the computational precision and stability of the former ANNs are more satisfactory than those of the latter. It is concluded that the flexibility of ANNs in generalizing can be effectively increased by use of uniformly distributed training samples rather than simply piling data.More reliable uniformity should be obtained, however, through NTMs instead of equal-spaced samples.     

卡尔曼滤波过程的稳定性研究

卡尔曼滤波器的稳定性并不能保证实际的滤波器算法具有收敛性,而传统的关于滤波发散的判定方法是基于量测不能出现野值这一严格的假设条件,具有一定局限性;并且通常关于滤波发散只是一种定性的描述,具有一定模糊性。为此,考虑到量测可能出现野值的情况,从滤波发散的具体数学形式出发,提出了卡尔曼滤波过程的稳定性概念,在此基础上给出了滤波发散的判定定理,既消除了通常关于滤波发散描述的模糊性,又降低了通常判定方法的要求。     

MIC-120金属拱型波纹屋面稳定性的研究

分别采用简单公式和有限元法计算了MIC-120金属拱型波纹屋面的临界载荷,分析了金属拱型波纹屋面稳定性,并且和拱型波纹屋面临界载荷的试验结果进行了对比,着重分析了MIC-120金属拱型波纹屋面面外失稳问题.理论分析和试验结果吻合.研究结果表明,拱型屋面的破坏不是强度不足,而是失稳所致.     

科技术语的符号学诠释

术语是通过语音或文字来表达或限定专业概念的一种约定性符号[1] ,术语规范化实质上是一个建立规范的文字符号模型并使其成为全社会定约的过程。基于上述认识 ,我们可以借鉴符号学、语言学、编辑学等学科的一些基本理论来研究术语学问题。本文即是从科技术语是形式和意义相结合的符号系统这一视角出发 ,应用符号学的若干基本原理 ,提出和探讨术语符号的一些基本性质及构成特性问题。　　一、符号和术语符号在人类发展过程中 ,由于生产劳动的社会性 ,人们需要经常交流思想、密切协作 ,而这种交往与合作 ,要求人们能够明确无误地表达出自己的…