复介电常数在绝缘子污秽检测中的应用

根据微波辐射特性，提出了一种新的污秽检测方法，该方法利用污秽物的复介电常数特性作为主要参数之一来测量污秽等级。分析了污秽复介电常数与辐射亮温的关系，并利用微波波导测量法测量了实验室制备的各种不同含水含盐的污秽物的复介电常数，研究了介电常数的实部和虚部与含水量、盐度的关系，给出了污秽辐射亮温与盐度的关系。实验研究结果表明污秽物复介电常数的实部与含水量、虚部与盐度存在确定关系，这为利用微波辐射计检测污秽物的性质提供了可能和实验依据。     

特约文章：黄河流域人水关系作用机理及和谐调控

人水关系复杂且涉及要素众多,探究人水关系作用机理,针对人水关系存在的问题提出和谐调控路径具有重要意义。本文以黄河流域为例,从人文系统与水系统的自身复杂性、耦合系统复杂性、相互作用复杂性三方面阐述了人水关系的复杂性;分析了人水关系作用过程,基于人水系统互馈作用关系揭示了人水关系作用机理,总结了现阶段黄河流域人水关系存在的问题;提出了利用和谐调控解决人水关系问题的基本思路和理论方法。“黄河分水”和“区域水资源与经济社会和谐平衡”两个实例应用研究结果表明,面对黄河流域复杂的人水关系,利用和谐调控理论方法可优化流域分水方案,提高区域和谐水平,促进人水关系和谐发展,为解决人水关系问题提供了有效的手段。     

从煤的燃烧技术浅谈能源利用的可持续发展

在简要回顾我国能源构成、利用现状及其面临挑战的基础上,分析了能源利用与环境的关系,指出走可持续发展道路是今后我国能源利用必由之路,并且只有依靠科技进步才能实施能源利用的可持续发展战略。     

冲积河道冲淤临界流量的探讨

利用非饱和和输沙公式，首次提出了以悬移质为主的冲积河流中冲淤临界流量与水沙以及边界条件的一般关系。该关系表明，冲淤临界流量主要与含沙量成某一次方的比例关系，同时受水沙搭配关系以及边界条件的影响。     

基于蚁群算法的开关电弧电流分布重构

基于电弧电流与磁场分布的对应关系,提出了一种通过蚁群算法来反演电弧电流分布的有效方案。将电弧磁场定义为电流线磁场的叠加,依据磁场分布和电流线与磁场的关系,利用求解线性方程组得到电流线分布初值;最后,利用改进的蚁群算法,对电流线与磁场之间对应关系进行精确拟合,反演二维情形下的电弧面电流密度分布。     

以塔架应力判断风力发电机组整体稳定性的方法

本文通过对风力发电机组塔架根部应力与整机稳定性的关系分析，推导出了塔架根部应力与风力机倾覆力矩、基础底部压力的偏心距及基础底面持力层土壤的容许承载力之间的关系表达式。确定了利用应力函数判断风力机的整体稳定性，从而得出了可以利用检测塔架根部应力监测风力机整体稳定性的结论。     

电力弹性系数分析及应用

根据电力弹性系数的定义,推导出电力弹性系数与GDP增速和GDP平均电耗及GDP电耗下降速度间的关系表达式,并介绍利用这一关系式进行电量预测的新方法。     

电机振动分析及微机识别和监测

介绍了一些分析电机振动的方法及其相互间的关系。讨论了识别电机振动的意义、电机振动与故障诊断的关系、振动监测原理和监测手段。论述了利用微机监测和诊断故障的可能性。     

超临界机组锅炉管内壁清洁程度与流动压降的关系分析

利用流体力学定常流动动量方程分析了流动压降与管内粗糙度的关系,并在此基础上利用某超临界机组现场运行数据和检修收集的管内氧化膜量等数据,总结了该机组炉管压降与省煤器入口氧化物沉积量的数量关系,可用于近似评估运行过程中氧化物的沉积量。该方法对实现在线评估管内清洁度有一定指导意义。     

基于本体的面向股票领域的检索系统研究

在传统的信息检索系统中,用户只能通过诸如现大量与用户查询相关度低甚至无关的内容.本文将本体技术运用到传统检索系统中,提出基于本体的信息检索模型框架,列举相关的各项技术,利用反映概念之间关系的领域本体指导主题标引,利用反映实体之间关系的领域本体指导实体关系标引,并以本体的形式表示文档替代物和查询表达式,该方法可以进一步提高文本信息检索系统的性能.     

基于MEMS传感器的运动加速度提取技术研究

结合多种现有物体运动加速度测量方法的特点,提出了一种基于MEMS运动传感器低成本且便捷的运动加速度测量方法。该方法采用多传感器数据融合技术实时求解物体的运动姿态,进而从MEMS运动传感器的实测数据中提取物体运动加速度。通过搭建基于MEMS运动传感器的加速度测量系统对该方法的可行性进行试验验证,试验结果表明,在静止状态下该方法的加速度求解误差为0.03 m/s2,与MEMS加速度计采集精度基本一致,具有较高的求解精度;在自由落地运动时该方法的加速度求解误差为0.07 m/s2,虽然物体长时间剧烈运动时耦合运动加速度会降低求解精度,但在短时间运动时仍具有较高求解精度。     

500kV交流输电线路下金属体尺寸对暂态电击水平的影响研究

人体接触处于高压输电线下的金属体时,会发生暂态电击。采用有限元软件ANSYS建立简化人体模型和金属体模型,计算其感应电压、感应电场,在Simulink搭建接地人体接触对地绝缘的悬浮金属体及对地绝缘的人体接触接地体的仿真模型。通过分析感应电压、放电能量及放电电荷量等参量随金属体尺寸的变化规律,从而得到不同尺寸金属体对人体电击效应的影响。结果表明,当金属体在垂直导线方向尺寸不变时,其感应电压基本不变,此时,若直接接地人体接触金属体,放电电荷量和放电能量随平行导线方向尺寸增大而线性上升,而对地绝缘人体接触接地体,放电电荷量和放电能量则随平行导线方向尺寸增大线性下降。     

变频调速系统离散化迭代学习控制法

针对变频调速系统抗负载扰动性能差,在宽范围内调速时非线性数学模型变化的控制效果变差,提出用可编程控制器(PLC)做调节器,形成速度负反馈.采用迭代自学习控制方法,可以逼近期望的轨迹线,并且得到了较好的效果.文中根据误差收敛准则,使用非线性离散系统迭代学习控制算法,证明了PI型迭代学习控制算法的收敛性.简单实用.     

Effect of Moving Speed of Charged Metallic Spherical Electrode on Electrostatic Discharge

In this investigation, the nature of the electrostatic discharge (ESD) that occurs when a charged object moves toward a stationary grounded object is experimentally clarified. The spark lengths, discharge currents, and induced voltages in a magnetic probe were measured when a charged metallic spherical electrode connected to a 422 pF capacitor approached a stationary grounded object, which was the current target, for different moving speeds of the charged metallic spherical electrode in a range of 1 mm/s to 100 mm/s. The charge voltages of the capacitor were +6.5 kV and +10 kV. Based on the results, the average gap length shortened with the speed of the spherical electrode. The average peak values of the discharge current and the induced voltage were likely to increase with the speed of the spherical electrode. The average rise times of the discharge current and the induced voltage were likely to drop with the speed of the spherical electrode. The relation between the spark length and the discharge current due to the ESD can be explained qualitatively by using an equation derived from the spark resistance formula proposed by Rompe and Weizel.     

Visual‐based and object‐conscious image retrieval by block reallocation into object region

‘Visual‐based’ image retrieval based on the visual similarities over the entire image is one of the powerful and useful ways when targeting large volume content with inadequate annotation. Generally, conventional methods divide a query image and target images in the database into grid‐shaped blocks and calculate the similarity based on image features by comparing each corresponding block straightforwardly. However, the method sometimes fails in terms of object‐conscious retrieval when their backgrounds are almost the same but the only the object is different or the object's size and/or position is different. To solve the problem, we propose a new method featuring the reallocation of some blocks to the object region (OB‐blocks) and a new similarity score by placing a weight on the OB‐blocks, which are derived from the visual saliency map. Our proposed method could realize ‘visual‐based and object‐conscious’ image retrieval. We verify the effectiveness of this method through comparison experiments. © 2016 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

基于双边滤波的协方差目标跟踪算法

现有的使用协方差建模的目标跟踪方法在目标形变或是光照变化较大的情况下,达不到理想的跟踪效果。在分析目前协方差建模目标跟踪方法缺点的基础上,提出一种融合双边滤波的协方差目标跟踪算法。首先,将待跟踪图像进行双边滤波,提取滤波后的图像特征构建协方差特征矩阵作为跟踪模板。其次,由于协方差矩阵为对称正定流形,服从对数-欧几里德黎曼度量。在此度量下,构建了目标协方差矩阵相似性度量和模板更新策略。各种条件下的实验结果表明,新构建的基于双边滤波的协方差特征矩阵对目标形变和光照变化有更好的适应性。     

工频自动加压装置中的干扰及其抑制

主要对在实验室内进行工频耐压试验,试品击穿放电时所产生的严重干扰现象进行分析研究,提出了抑制干扰的方法。     

A model of an intact power facility as an indicator of damage

A general approach to the detection of faults in observed power system facilities is considered. An important property of the intact object model, namely, its capability of selecting the modes of the electric system that includes the protected object, is indicated. The entire set of the modes is divided into two subsets designated as the α and β modes. If it is in the α modes, the protected object is damaged, and, if it is in the β modes, it is in operating conditions. The selectivity of the relay protection is ensured by complete separation from the β modes. The model adequate to the intact power facility copes with this task. Upon damage to the object when the adequacy of the model is violated, the necessary prerequisites are created to ensure the acceptable sensitivity and speed of the relay protection. As an example, two power facilities are considered, i.e., a power-transmission line with one-sided monitoring and a three-phase transformer with a DYN winding connection. The β modes are faults outside the protected zone for the power-transmission line and magnetizing- current inrushes for the transformer.     

锅炉过热器动态特性数理分析及其状态观测器的鲁棒性

该文以过热器蒸汽温度受控对象为例，剖析了单相受热管焓一温通道的几种集总参数数学模型，它们共同的特性是特征方程的解均为实数根，从而具有过阻尼的性质。在此基础上，进一步揭示应用高阶等容惯性环节作为锅炉过热器蒸汽温度受控对象的状态观测器这一方法内在的数学与物理基础，进而得出在设计锅炉过热器蒸汽温度受控对象的状态观测器时，不必受对象阶数的限制，通过调整观测器的参数，同样可以很好地完成重构状态并进行极点配置，起到改善受控系统动态特性的设计效果。工程实践表明：采用高阶惯性环节作为过热器蒸汽温度的状态观测器是可行的，适用的。     

The role of viewing angle in integrating the senses of vision and touch for perception of object softness

Enabling surgeons to interact intuitively and accurately with virtual reality (VR)?based environments using their senses of vision and touch (e.g., to distinguish the softness of tissues) is a challenging issue for surgical planning. This paper presents the results of two experiments that were conducted to determine how viewing angle affects the perception of object softness and to investigate the mechanisms for integrating the senses of vision and touch. The two experiments used virtual reality setups with different locations of a haptic device. In each experiment, 15 human subjects were tested in cases where both visual and touch (haptic) information was available and again when only visual or haptic information was available. In each trial, subjects were asked to select the harder object among two deformable balls placed at different viewing angles. The results of both experiments showed that viewing angle affects the perception of object softness: the larger the viewing angle, the harder the ball was perceived to be. When two viewing angles differed by at least 15°, there was a significant difference in perceived object softness. By computing the individual and combined weights of visual and haptic information, it was determined that visual information and haptic information depend upon each other, contradicting the assumption of independence employed in other studies. Comparison of the two experiments revealed that the location of the haptic device also affects the perception of object softness.