Discovering knowledge from medical databases using evolutionoryalgorithms

Discusses learning roles and causal structures for capturing patterns and causality relationships. The authors present their approach for knowledge discovery from two specific medical databases. First, rules are learned to represent the interesting patterns of the data. Second, Bayesian networks are induced to act as causality relationship models among the attributes. The Bayesian network learning process is divided into two phases. In the first phase, a discretization policy is learned to discretize the continuous variables, and then Bayesian network structures are induced in the second phase. The authors employ advanced evolutionary algorithms such as generic genetic programming, evolutionary programming, and genetic algorithms to conduct the learning tasks. From the fracture database, they discovered knowledge about the patterns of child fractures. From the scoliosis database, they discovered knowledge about the classification of scoliosis. They also found unexpected rules that led to discovery of errors in the database. These results demonstrate that the knowledge discovery process can find interesting knowledge about the data, which can provide novel clinical knowledge as well as suggest refinements of the existing knowledge     

基于光纤传感的井架和底座承载力监测系统

井架和底座作为石油钻机系统中的重要设备,其承载能力直接影响着油田钻井生产的安全和效益。由于恶劣环境影响,钻机井架和底座会出现腐蚀、磨损以及载荷增加等问题,因此有必要将井架、底座承载能力与安全评估技术联系起来,以保证钻机生产作业的安全性。因此,本文重点对钻机井架及底座的承载能力开展安全评估技术研究。首先采用有限元仿真找出井架和底座的起升工况下的最大应力监测位置,进而利用光纤光栅监测技术,对钻机关键结构件井架和底座的起升、下放和作业工况的关键受力截面进行应变监测,防止超设计能力作业和意外情况出现。试验结果证明,钻机井架和底座的应变测量值与外力载荷呈线性关系,拟合程度分别是99.48%和99.85%,本系统可以对井架和底座的应变进行监测,实现了钻井装备的承载力监测事前预警、事后支持,更安全地保障油气资源勘探开发。     

An analysis of IEEE publications

This study reports on a few elements of the scientific production of the IEEE. Other features could be displayed that would be interesting for a better understanding of the trajectories of the societies, journals, etc. The possibility of projecting new data onto the current spaces allows researchers to see if journals are static (the concepts and methods remaining stable) or dynamic (evolutions, ruptures can be tracked). In other words, this type of analysis can be used as a strategic tool to follow the impact and trends in engineering sciences. The fact that the authors concentrate on the IEEE publications prohibits any comparison with other societies publishing engineering papers. Such insights are feasible through the analysis of the INSPEC database. This could bring other clues on the coverage, the competition, and the reaction to new areas.     

我国首台超临界机组X20CrMoV121钢受热面管状态分析

为全面了解火电厂X20CrMoV121钢受热面管长期运行后的安全状况,对某电厂X20CrMoV121钢末级过热器管及高温再热器管进行了力学性能测试、显微组织分析及高温持久强度试验。试验结果表明,运行管与原始管相比强度有所下降;沉淀相发生熟化,同时还出现了局部板条特征减弱,板条内出现亚结构,位错密度明显降低,且在亚结构内位错呈定向排列的趋势;高温持久强度仍然高于设计值。综合分析认为,经12万h运行后的X20CrMoV121钢管产生了一定程度的老化,但仍可满足设计工况下安全运行的要求。     

Polymer nanocomposites as dielectrics and electrical insulation-perspectives for processing technologies, material characterization and future applications

Polymer nanocomposites are defined as polymers in which small amounts of nanometer size fillers are homogeneously dispersed by only several weight percentages. Addition of just a few weight percent of the nanofillers has profound impact on the physical, chemical, mechanical and electrical properties of polymers. Such change is often favorable for engineering purpose. This nanocomposite technology has emerged from the field of engineering plastics, and potentially expanded its application to structural materials, coatings, and packaging to medical/biomedical products, and electronic and photonic devices. Recently these 'hi-tech' materials with excellent properties have begun to attract research people in the field of dielectrics and electrical insulation. Since new properties are brought about from the interactions of nanofillers with polymer matrices, mesoscopic properties are expected to come out, which would be interesting to both scientists and engineers. Improved characteristics are. expected as dielectrics and electrical insulation. Several interesting results to indicate the foreseeable future have been revealed, some of which are described on materials and processing in the paper together with basic concepts and future direction.     

Distribution system minimum loss reconfiguration in the Hyper-Cube Ant Colony Optimization framework

This paper presents an original application of the Ant Colony Optimization concepts to the optimal reconfiguration of distribution systems, with the objective of minimizing the distribution system losses in the presence of a set of structural and operational constraints. The proposed algorithm starts from the current configuration of the system and proceeds by progressively introducing variations in the configuration according to local and global heuristic rules developed within the Hyper-Cube Ant Colony Optimization framework. Results of numerical tests carried out on a classical system and on a large real urban distribution system are presented to show the effectiveness of the proposed approach.     

含复杂渗控结构渗流问题数值模拟的SVA方法

本文采用排水子结构、Signorini型变分不等式和自适应罚Heaviside函数相结合的方法(简称SVA方法)解决含复杂渗控结构的渗流问题.排水子结构法用于模拟小孔径密集排布的排水孔幕的渗流行为,简化有限元建模;变分不等式法用于确定渗流出渗点和自由面的位置,消除出渗点的奇异性;而自适应罚Heaviside函数则用于克服网格依赖性和数值不稳定性,确保算法的鲁棒性和解的稳定性.通过算例验证了SVA方法的有效性和鲁棒性.     

喷水推进与泵喷推进的对比研究

针对船舶推进领域"喷水推进"与"泵喷推进"两概念混淆的现状,本文从两者的起源及发展历程出发,在系统分析两者结构型式的基础上,根据流体力学控制体原理及喷水推进泵理论剖析了两者的水动力原理及核心部件的做功机理。针对控制体的外流场问题,运用翼型升力理论及叶片泵理论推导演绎了外置式喷水推进与泵喷推进外流场对推进系统总推力的作用,阐明了两者原理相同、核心功能转化部件均为喷水推进泵,论证了泵喷推进为喷水推进在水下航行体领域应用时的特定称谓,是喷水推进技术在水下航行体领域的发展。     

基于模糊TOPSIS和BP网络的电力变压器故障诊断方法

针对传统故障诊断技术中存在诊断模型结构复杂以及收集故障样本数据非常繁琐的问题,将TOPSIS方法在Vague集下进行扩展。介绍了Vague集的基本概念及其相似度量方法,以及使用Vague集表达的语义变量集,并据此对原始样本集进行优劣排序和聚类,从而缩减了样本集的容量,使得故障特征信息量和映射空间复杂度的问题在一定程度上得以平衡。在此基础上构建了适应于变压器故障诊断的BP网络诊断模型,实现对不同类型故障的诊断。算例分析表明,此方法与传统的变压器故障诊断的方法相比较具有明显的优越性。     

子结构法在输电塔全方位长短腿计算中的应用

全方位长短腿输电塔已广泛应用于山区输电工程,但组合计算耗时过长始终是精确优化分析的最大障碍。考虑到不同长短腿组合模型结构上的相似性,提出将一种改进的子结构法引入内力计算过程。输电塔被分为子结构和腿部结构2部分,通过分块分解法计算等效刚度矩阵和荷载列阵,从而完成自由度凝聚和边界节点的处理,去除了绝大部分自由度组装和分解的时间,提高了计算效率。结合耗时分析,进一步提出了减少工况数目的方法。     

信阳华豫电厂2 ×300 MW机组顺序控制系统的改进

顺序控制系统(SCS) 是用于辅机联锁保护的一种较为先进的控制手段。信阳华豫电厂采用的SCS ,在调试过程中发现原设计逻辑存在一些缺陷。对锅炉风烟系统、锅炉制粉系统、除氧给水系统和汽机润滑油系统等控制逻辑进行了改进,使得整个顺序控制系统更加完善,其辅机的联锁保护动作更加准确可靠, 有利于整个机组的安全稳定运行。     

基于符号时间序列法的风电功率波动分析与预测

风电功率波动与预测是风电并网研究的主要内容。针对风电功率的随机波动特性,将符号时间序列方法应用于风电功率波动与预测分析中,并提出一种自适应分区方法,该方法根据数据序列分布的密集程度,实现数据序列区域的非均匀分割,找出信息量丰富的区域,以便突出反映数据的变化情况。之后,以符号序列直方图理论为基础,通过直方图求逆实现原始数据序列关键数据区域的定位,进而完成风电功率的预测。以某一风电场实测风电功率数据验证所提方法的有效性,为风电功率调度提供参考。     

模型-数据混合驱动的电网安全特征选择和知识发现关键技术与工程应用

随着可再生能源的大规模并网、需求响应的逐步实现,电网运行方式的复杂性和波动性不断攀升,电力系统的安全运行正面临新的需求与挑战。因此,基于人工智能技术,在广东电网建立了"模型—数据混合驱动的电网安全特征选择和知识发现平台",保证电网安全、稳定、经济运行。文中首先定义了电网安全特征和知识,阐述了模型—数据混合驱动的思想与具体实现方法,并分析了降低误差的手段;其次阐释了平台的并行计算技术;接着设计了平台的软硬件架构;最后,展示了平台在广东电网的实际应用效果,结果表明:(1)从运行规则制定层面,将运行专家离线制定粗放运行规则的模式,变革为人工智能在线发现精细运行规则的模式;(2)从运行规则应用层面,将调度员人工判定运行规则的模式,变革为人工智能实时判定运行规则的模式。     

INDUCTIVE SENSORS FOR DISTANCE MEASUREMENT THROUGH A METALLIC SCREEN: APPLICATION TO THE PRIMARY CONTROL OF A NUCLEAR REACTOR

ABSTRACT

This paper presents an interesting design of magnetic sensors applied to the distance measurement, through a metallic medium [1]. By a detailed physical analysis of this problem, an original modelling for predetermination and optimisation of the performances of this system is achieved, and successfully compared with experimental results. The interest of such a system is demonstrated through two major industrial applications, linked to the control of a pressurised water reactor with enriched uranium. In a first application, the sensor is used to detect the passage of magnetic slots, and provides some informations for incremental counting. This system gives reliable data on the position of the control rods moving up and down into the nuclear reactor. The other application uses the signals given by both elements of a twin sensor and a target with particular geometrical dimensions. A differential measurement between the two sensors gives an analog information on the lateral position of the target, and the system is used to control the positon of water gates located on the coolant circuit.     

Aging of equipment in the electric utilities [comments and reply]

For original paper see ibid vol. 28, p 888-75 (1993). The original article reviewed the existing knowledge of insulation aging in utility systems. The discussion presents a large variety of interesting questions which need to be resolved, but could only be answered by extensive future research     

BTV图像超分辨率重建改进算法

在双边滤波正则化算法的基础上,结合自然图像自身结构相似性,提出一种基于BTV的改进算法.通过在代价方程中引入表达图像非局部结构相似性的正则化项,对重建图像的解空间进一步加以限制和优化,最后通过最陡下降法求得代价方程最优解,从而完成重建.实验证明,与BTV算法相比,改进后的算法不仅能很好地抑制噪声,同时也更好地保留了图像...     

滑动(水箱)式多模拉丝新原理概要

本文是笔者研究滑动式拉丝所写十余篇论文的综合性介绍。文章简略评述了传统理论的失误 ,提出了一套完整的新原理 ,使用了与传统理论完全不同的计算公式 ,彻底探明了滑动的客观规律 ,并提出了一系列新概念和新观点。     

Sustainability and the design of knowledge tools

The concept of sustainable development has gained widespread support over the last decade, with many organizations adopting it as an important goal. The motivation behind people's interest in sustainable development is the belief that current human activities may degrade the environment and cause serious negative consequences for human populations. These concerns are especially understandable when we consider that the current practices of industrialized countries will in the future be used to support an ever-growing population. What needs to be present in any useful discussion of sustainability is a rigorous application of both relevant theory and technological expertise. These are examples of knowledge tools which can be used to organize and give meaning to data, create and analyze concepts, and synthesize the two (data and concepts) to aid in decision making. The author offers some insights which may help in the design of knowledge tools for a sustainable civilization     

倒置式电流互感器带电取油样装置的研制

根据油浸倒置式电流互感器的结构特点,研制了带电取样装置,利用油样引下装置将油样引至工作人员方便采集的位置,避免了设备因油样采集而停电,保障了作业安全,实现了倒置式电流互感器带电取样.通过数据对比,证实油样引下装置不会增加油量消耗,所采油样的色谱数据也与原采样装置基本吻合.