模糊神经网络在电力短期负荷预测中的应用

提出用于电力短期负荷预测(SILF)的一种模糊神经网络(FNN)方法，该方法针对BP网络收敛速度慢、易导致局部极小值的缺点，将考虑气候、温度、星期类型等影响因素的模糊技术与快速二阶BP网络相结合，并以南方电网负荷预测为例，应用MATLAB蚀语言对系统进行仿真训练，测试结果表明，该方法具有较高的预测精度。     

On the multi‐input second‐order sliding mode control of nonlinear uncertain systems

This note addresses the multi‐input second‐order sliding mode control design for a class of nonlinear multivariable uncertain dynamics. Among the most important peculiarities of the considered control problem, the considered sliding vector variable has a uniform vector relative degree [2,2, … ,2] with respect to the vector control variable, and only the sign of the sliding vector and of its derivative are available for feedback. Additionally, the symmetric part of the state‐dependent control matrix is supposed to be positive definite. Under some further mild restrictions on the uncertain system's dynamics, a control algorithm that realizes a multi‐input version of the ‘twisting’ second‐order sliding mode control algorithm is suggested. Simple controller tuning conditions are derived by means of a constructive Lyapunov analysis, which demonstrates that the suggested control algorithm guarantees the semiglobal asymptotic convergence to the sliding manifold. Simulation results, which confirm the good performance of the proposed scheme and investigate the actual accuracy obtained under the discrete‐time implementation effects, are given. Copyright © 2011 John Wiley & Sons, Ltd.     

A Measurement‐Based Approach for Designing Fixed‐Order Controllers for Unknown Closed‐Loop Architecture

This paper presents a new technique to design fixed‐structure controllers for linear unknown systems using a set of measurements. In model‐based approaches, the measured data are used to identify a model of the plant for which a suitable controller can be designed. Due to the fact that real processes cannot be described perfectly by mathematical models, designing controllers using such models to guarantee some desired closed‐loop performance is a challenging task. Hence, a possible alternative to model‐based methods is to directly utilize the measured data in the design process. We propose an approach to designing structured controllers using a set of closed‐loop frequency‐domain data. The principle of such an approach is based on computing the parameters of a fixed‐order controller for which the closed‐loop frequency response fits a desired frequency response that describes some desired performance indices. This problem is formulated as an error minimization problem, which can be solved to find suitable values of the controller parameters. The main feature of the proposed control methodology is that it can be applied to stable and unstable plants. Additionally, the design process depends on a pre‐selected controller structure, which allows for the selection of low‐order controllers. An application of the proposed method to a DC servomotor system is presented to experimentally validate and demonstrate its efficacy.     

磁悬浮控制力矩陀螺锁紧机构可靠性设计及优化

鉴于传统确定性优化方法没有考虑结构参数的随机性对结构性能的影响,本文提出了一种基于可靠性灵敏度的锁紧弹片结构优化方法。首先,以某磁悬浮控制力矩陀螺锁紧弹片为研究对象,研究了有限元建模和失效模式;然后,考虑弹片结构尺寸和材料参数的随机性,结合响应面法与一次二阶矩法,研究了串联失效模式下弹片的可靠度计算方法,进而推导了可靠性关于设计变量均值和方差的灵敏度计算公式;最后,根据灵敏度分析结果,研究确定了弹片结构优化策略,构建了弹片可靠性优化模型。分析了安全系数法和可靠性法优化结果的差异,结果表明:与安全系数法相比,可靠性法的优化结果更好;在保证弹片可靠度的前提下,采用可靠性优化方法不仅使弹片质量下降了23.71%,使锁紧机构更加优化,而且使陀螺房质量也下降了0.98kg,有利于磁悬浮控制力矩陀螺整机结构的轻量化。     

气相色谱法分析厌氧反应器中的挥发性脂肪酸(VFA)

挥发性脂肪酸（ＶＦＡ）是厌氧反应器运行中重要的控制指标。研究了用程序升温及恒温分析厌氧反应器中ＶＦＡ的两处最佳色谱条件,程序升温较恒温条件下样品分离效果好,标准误差及变异系数小,样品回收率高,缺点是测一个样需３０ｍｉｎ,耗时;恒温法的优点在于样品测定简便快速,测一个样只需８～１０ｍｉｎ。同时比较了样品预处理加酸与不加酸的效果。证明样品酸化（ｐＨ小于２）是用气相色谱法直接分析ＶＦＡ的必需预处理。     

价格决定报童模型不确定需求在普通随机序下的一些结果

在普通随机序下讨论了一般情形价格决定报童模型不确定需求的一些结果.     

层次分析法(AHP)在效益评价中的应用——1995年河南省各地市工业经济效益综合评价

应用层次分析法对１９９５年河南省各地区工业经济效益进行了分析和排序，指出河南省各地区工业发展很不平衡，政府有关部门应针对实际制定政策，提高全省工业整体水平。     

介词结构语序研究回顾与展望

介词结构语序在现代汉语中违背了中心语边缘原则,对普遍语法理论提出了挑战,自《马氏文通》以来一直是学者研究的热点。现代汉语缺少形态标记,语序问题常常又与句法关系联在一起,因此本文首先回顾介词结构的句法功能探讨,然后综述介词结构语序特点的历时和共时研究,同时梳理介词结构语序研究的理论维度。文章最后指出,介词结构语序研究在理论视角、系统性以及对语序变异原因的深入挖掘等方面还存在不足。     

Ku波段带通滤波器的设计与实现

介绍一种微波高频段带通滤波器的设计方法,同时给出一个滤波器的设计实例和测试结果。利用制作简单的园棒内导体结构,采用梳状线与同轴腔相结合的方式,实现窄带带通滤波器,达到结构紧凑、性能优良、方便组件集成的使用效果。     

一种新的最优小波基选择准则及其应用

针对分数低阶口稳定分布信号具有显著脉冲这一特性,参照最优小波包基选择的熵准则,提出了一种针对该类噪声的最优小波基选择新准则,解决了以往最优小波基选择的熵准则中,由于需计算二阶统计量而不适合分析分数低阶口稳定分布信号的问题.还得出了针对该类信号,在运用该新准则进行判别最优小波基时,只需对各个小波基函数在第1层尺度下的变换系数进行对比判别的结论,极大地减化了以往多尺度的判别过程.将新准则应用于医学超声图像消噪时,获得了较好的效果.