一种基于二阶统计的盲源分离方法及性能分析

提出了一个基于信息论原理的目标函数 ,该目标函数可以作为衡量输出分量独立性的标测度。最小化该目标函数并利用信号的非平稳特性和两种网络结构形式的等价性 ,得到一种可以进行非平稳信号的盲分离的训练算法 ;计算机仿真结果表明了该算法的有效性。最后对目标函数的性能进行了分析。     

岩石孔底断裂控制机理研究

在保证垂直槽孔断开明成型并全面贯通的孔压下，对孔底水平截面Ｉ－Ⅱ型复合裂纹断裂与装药结构的关系等进行了分析，建立了断裂判据，初步确定了裂纹扩展的方向及预应力对断裂的贡献。其结果与工程实践相吻合。     

Transmission and demodulation of multi-polarization-multiplexed signals

We propose the configuration of signal multiplexing with four polarization states and investigate its transmission performance over single-mode fiber links. Using coherent detection and digital signal processing, a demodulation scheme for four-polarization-multiplexed (4PM) system is presented. We discuss the impact of crosstalk from polarization mode dispersion and polarization beam splitter misalignment on the proposed 4PM system. Furthermore, the transmission distance could be doubled to ~50 km by employing feedback decision equalizers.     

简易多路无线智能报警系统

文章设计了一款家用简易智能报警系统．其主要功能是，当非法入侵者侵入时，由传感器触发报警信号，利用无线收／发模块通过无线多路编码、解码技术，将报警信号传送给单片机，单片机驱动摄像头自动拍摄入侵者相貌。通过射频收发器NRF905将报警信息发送到中央值班室，在值班室的显示屏上．可以直观显示被盗情况，为刑事侦破提供可靠的证据．     

Discussion of the Constitutive Relation on Cyclic Stress-Strain of Engineering Materials

Based on the experimental results and analysis of the cyclic deformation, there is an obvious yield stage on the cyclic stress-strain curve at the stage of small plastic deformation (in room or low temperatures). This phenomenon is similar to that of monotonic tensile curve case. But for the former the deformation amount at which the yield begins is much smaller than that for the latter. The cyclic stress-strain constitutive relation needs to be further studied according to the actual cyclic stress-strain curve. The conventional constitutive equation σ=Aεn is based on the results only corresponding to the cyclic strengthening stage. It is not appropriate for the stage of the small plastic deformation and the stage of yield.     

ARTIFICIAL NEURAL NETWORK BASED ASSEMBLABILITY EVALUATION

Assemblability evaluation is a pivotal step in design for assembly (DFA). In this paper, the authors analyze the problem existing in previous assemblability evaluation methods, put forward a new approach-Artificial Neural Network based Assemblability Evaluation Method (AAE), describe the principles and implementations of the neural network in use for assemblability evaluation. AAE has been put into use in product design. The results of the experiments and analyses show that assemblability is measured more objectively, accurately and completely by using AAE than the conventional methods.     

MONT—PVA夹层复合物原位合成β′—sialon

利用蒙脱石层间域活性，在特定条件下合成ＭＯＴＮ－ＰＶＡ（蒙脱石－聚乙烯醇）夹层复合物并以此复合物为前驱体，在流动的Ｎ２中进行碳热还原反应，在高温过程中，层间的ＰＶＡ原位碳化并充当反应的还原剂，伴随少量杂质晶相的形成，得到了β′－ｓｉａｌｏｎ，β′－ｓｉａｌｏｎ晶相的临界生成温度较低，产物纯度高，前驱体的纳米级的二维密度结构起决定性的作用。     

Target estimation using MIMO radar with multiple subcarriers

This paper analyzes the effect of waveform parameters on the joint target location and velocity estimation by a noncoherent multiple input multiple output (MIMO) radar transmitting multiple subcarriers signals. How the number of subcarriers influences the estimation accuracy is illustrated by considering the joint Cramer-Rao bound and the mean square error of the maximum likelihood estimate. The non-coherent MIMO radar ambiguity function with multiple subcarriers is developed and investigated by changing the number of subcarriers, the pulse width and the frequency spacing between adjacent subcarriers. The numerical results show that more subcarriers mean more accurate estimates, higher localization resolution, and larger pulse width results in a worse performance of target location estimation, while the frequency spacing affects target location estimation little.     

具极小化局部截断误差的Runge-Kutta方法

使用本文提出的既不增加函数f(x,y)求值的个数计算又不要求f(x,y)及(?)~(i+j)f/(?)x~i(?)y~j 为有界的方法,便建立了具极小化局部截断误差的二级二阶直到四级四阶的Runge-Kutta 公式.这些公式均可用于求解非线性一阶常微分方程组,且是对Lotkin(1951)、Ralston(1962)、Merson(1975)、Scraton(1964)、England(1969)的结果的一种改善和推广.此外,当常微分方程组退化成一个方程时,Lotkin(1951)和Ralston(1962)的若于结果就是本文特例.     

论T型结构人才的培养

本文以高等教育要适应社会发展的需求为基本前提，提出了新时期人才要具备T型知识结构及技能的必要性，并为实现这种人才培养目标提出了一系列的措施。