一种应用于移动终端的语音盲分离算法

盲分离算法被广泛应用于语音信号处理领域中。为改善移动终端的通话质量，提出了一种新的语音盲分离预处理方案，应用频域复随机梯度算法，分离出移动终端待传的主语音信号，从而使其它干扰语音得到抑制。模拟和实际录音的实验结果表明，该方法对改善通话质量有明显的效果。     

Reliability of power stations: Stochastic versus derated power approach

Consideration of the eventual forced outage of individual power stations leads to a large number of possible states of the power generating system, all with their own probability. It is possible to design a stochastic method to properly take into account all of these possibilities and to weigh them accordingly. In broader energy models, instead of these stochastic techniques that require a considerable amount of calculation time, mostly approximative static simplified methods are applied. Up till now, these simplified techniques have not been validated. The scope of this paper is to check their validity. Therefore, two approaches are compared: a complete stochastic approach and a method based on the derated power (which is the nominal power multiplied with the average availability) of the individual plants. The conclusion of this comparison is that derated power may be used in energy modelling instead of the complicated stochastic approach. The error made is very small and the correlation between the unserved load probability functions obtained by both methods is excellent. Copyright © 2004 John Wiley & Sons, Ltd.     

非线性时变随机系统状态及参数的实时联合估计

在文[1]中,我们给出了一种用于一类非线性时变随机系统的带次优渐消因子的扩展卡尔曼滤波器,可以估计出快速变化的系统状态.本文推广了文[1]的结果,使其可处理一般的非线性测量.同时,给出了一种状态及参数的联合估计方法.所做大量仿真研究表明,本文方法具有良好的实时性及动态跟踪性.     

Stochastic analysis of nonlinear vehicle systems using a generalized harmonic linearization technique

The discrete harmonic linearization method which is applicable to stochastic systems could not provide an equivalent stiffness coefficient for a nonlinear restoring element. In this paper, this technique is generalized to obtain linear representations of both nonlinear restoring and damping elements, based on a principle of energy similarity of dynamic elements. A numerical iterative procedure is presented to compute the local linear coefficients of nonlinear dynamic elements. A nonlinear system is then represented by a set of its complex frequency response function matrices, as functions of the excitation frequency. Stochastic analysis of general multi-DOF nonlinear vehicle systems is established in terms of response PSD characteristics.     

Random matrix eigenvalue problems in structural dynamics

Natural frequencies and mode shapes play a fundamental role in the dynamic characteristics of linear structural systems. Considering that the system parameters are known only probabilistically, we obtain the moments and the probability density functions of the eigenvalues of discrete linear stochastic dynamic systems. Current methods to deal with such problems are dominated by mean‐centred perturbation‐based methods. Here two new approaches are proposed. The first approach is based on a perturbation expansion of the eigenvalues about an optimal point which is ‘best’ in some sense. The second approach is based on an asymptotic approximation of multidimensional integrals. A closed‐form expression is derived for a general rth‐order moment of the eigenvalues. Two approaches are presented to obtain the probability density functions of the eigenvalues. The first is based on the maximum entropy method and the second is based on a chi‐square distribution. Both approaches result in simple closed‐form expressions which can be easily calculated. The proposed methods are applied to two problems and the analytical results are compared with Monte Carlo simulations. It is expected that the ‘small randomness’ assumption usually employed in mean‐centred‐perturbation‐based methods can be relaxed considerably using these methods. Copyright © 2006 John Wiley & Sons, Ltd.     

具有电阻场板的薄膜SOI-LDMOS的精确解析

介绍了一种对具有电阻场板的薄膜SOI LDMOS的精确解析设计方法.在对电场分析的基础上,提出了新的电离率模型,并求出了电离率积分的准确路径,进而得到击穿电压、漂移区掺杂、漂移区长度与SOI硅层厚度、埋氧层厚度的关系.模拟结果表明,解析与模拟结果具有很好的一致性,而且设计的器件具有击穿电压大、比导通电阻极小的优点.该解析理论为在薄膜SOI材料上制作性能优良的高压功率器件提供了一个很好的参考     

Systems Approach Vs. Decision-Tree Analysis: An Offshore Development Decision

A good investment decision-making process is one that is able to assess risk and uncertainty and is able to manage these in a balanced manner. A common practice in the oil and gas industry is to use a decision-tree analysis as a way to incorporate risk and uncertainty in investment decisions. In this article, we introduce an alternative called the system's approach based on a stochastic integrated asset model. The objective is to use the tried and tested decision-tree approach to show the validity of the system's approach and to show that with the incorporation of an infinite number of outcomes, decision-tree analysis results would approximate the results of the system's approach and then demonstrate the superiority of the system's approach. For a hypothetical but realistic example, we demonstrate that the decision-tree results differ by 5% for the mean and 20% for the standard deviation when compared to the system's approach. The decision-tree approach tends to underestimate the low side and overestimate the high side. This difference is due to the fact that the system's approach captures complexity, uncertainty, dependency, and interaction more accurately than the decision tree approach.     

锅炉引风机故障分析及改造方法

对锅炉引风机故障进行深入细致的分析。从而进行了改造，通过使用，获得了满意的效果。     

潇湘水库径流模拟及其灌溉配水研究

结合云南省曲靖市潇湘水库灌区工程实际，首先采用随机动态规划模型模拟潇湘水库的年径流、月径流，得到水库的入库径流过程，再根据系统论的思想建立了节水灌溉水量最优分配的模型：大系统分解——协调模型，获得了灌溉水量的最优分配方案。     

Node-Level Energy Management for Sensor Networks in the Presence of Multiple Applications

Wireless Networks - Energy related research in wireless ad hoc sensor networks (WASNs) is focusing on energy saving techniques in the application-, protocol-, service-, or hardware-level. Little...