基于知识本体的过程安全分析信息标准化

过程危险分析的主要目标是识别危险剧情。危险剧情能够表达团队“头脑风暴”安全评价过程也能表达评价结论。危险剧情的知识本体是标准化过程安全分析信息的准确描述。知识本体是概念表达的明确规范。依据设计知识本体所遵循的规则提出了一种过程安全分析信息标准化方法,称为剧情对象模型（scenario object model,SOM）。SOM能够表达安全分析信息的内容和结构,能够实施计算机自动推理和半定量计算。应用知识本体SOM有效实现了计算机辅助自动安全评价和安全信息的传递、复查和共享。     

基于小波奇异熵和SOM神经网络的微电网系统故障诊断

针对微电网系统运行方式灵活、拓扑结构多样的特点,基于对小波变换、奇异值分解和泛化信息熵基本理论的分析,揭示了小波奇异熵能够对故障信号给出确定的量度,将小波奇异熵与自组织特征映射(self-organizing feature map, SOM)神经网络相结合,提出一种能够适应微电网系统拓扑结构变化情况的故障诊断方法。 利用PSCAD4.2建立了微电网故障仿真系统,进行故障诊断仿真试验。 试验结果表明:该方法不受故障位置、故障时刻等因素的影响,在微电网系统拓扑结构发生变化的情况下,能实现有效的故障诊断。     

改进的GHSOM 算法在文本聚类中的应用

信息时代,文本信息极其巨大。本文运用一种改进GHSOM 算法进行文本聚类,该算法具有显著的文本聚类 能力,能够将文本的相似性用多种手段表现。实验结果表明改进GHSOM 算法整体上是优于SOM 算法,它的先进性主要体现 在更短的计算时间,并提供更丰富的有序性表达能力。     

Sensor fusion for online tool condition monitoring in milling

The objective of this paper is to combine a direct sensor (vision) and an indirect sensor (force) to create an intelligent integrated tool condition monitoring (TCM) system for online monitoring of flank wear and breakage in milling, using the complementary strengths of the two types of sensors. For flank wear, images of the tool are captured and processed in-cycle using successive moving-image analysis. Two features of the cutting force, which closely indicate flank wear, are extracted in-process and appropriately pre-processed. A self-organizing map (SOM) network is trained in a batch mode after each cutting pass, using the two features derived from the cutting force, and measured wear values obtained by interpolating the vision-based measurement. The trained SOM network is applied to the succeeding machining pass to estimate the flank wear in-process. The in-cycle and in-process procedures are employed alternatively for the online monitoring of the flank wear. To detect breakage, two features in time domain derived from cutting force are used, and the thresholds for them are determined dynamically. Again, vision is used to verify any breakage identified in-process through the cutting force monitoring. Experimental results show that this sensor fusion scheme is feasible and effective for the implementation of online tool condition monitoring in milling, and is independent of the cutting conditions used.     

The Global Architectural Influences on London

London today has become ‘a laboratory and testing ground’ for neoliberal capitalism, attracting investment from the Middle East, Russia, India, the Far East and Australasia as well as the US. Murray Fraser describes the urban impact of economic globalisation in the capital, while exploring ways that it might potentially be countered. Copyright © 2012 John Wiley & Sons, Ltd.     

基于自组织特征映射网络的纹理分类研究

提出了基于自组织特征映射网络（ＳＯＭ）的纹理分类方法。采用了适合纹理分析的纹理谱（ＴＳ）的概念，并在分类过程中引入了纹理谱特征向量，纹理谱向量是ＴＳ经过降维处理得到的．该特征向量反映了空间模式的纹理特征．在学习（训练）与分类识别中，采用了神经元网络模型．与ＴＳ相对应的特征向量重复地送入ＳＯＭ网络的输入端，网络的权向量则逐渐地将样本值聚类到各自的样本中心．计算机模拟实验表明，作者提出的纹理分类方案十分有效而且实用．本方案计算量小，学习周斯短，识别率高．本文最后给出了实验结果及分析．     

基于改进的SOM网络模型的VoIP QoS应用研究

VoIP的服务质量（QoS,Quality of Service）评估可以采用一系列可度量的参数来描述：业务可用性、吞吐量、延迟、抖动、分组丢失率等。现有的感知语音质量评价（PESQ）很难对不同环境下的网络结构进行实时和恰当的语音等级质量分类。为了能够综合考虑几种QoS相关因素,在给出改进的自组织映射神经网络模型（ESOMNN）的基础上,利用ESOM能够对高维输入数据有效分类的特点,提出了将端到端延迟、丢包率、抖动、语音编码以及测试系统标识作为ESOMNN的输入数据,在对采样数据进行训练后可自动完成语音质量评价和映射,并能根据得到的实时变量有效地评价包含多种相关因素的QoS级别。     

Strength in Numbers

David Salomon examines the history of the original World Trade Center (WTC) competition of 1962 and the more recent 2003 competition, finding interesting parallels in terms of how commercial and bureaucratic, as well as progressive, forces of innovation intersect over larger debates about control, power and questions of collaborative identity and practice within the city as a political machine, and which figure 9/11 in implicitly provocative ways. The 1962 competition featured another progressive architectural collaboration: Walter Gropius's The Architect's Collaborative (TAC). Not unlike the 2003 competition in which United Architects (UA) and other collaborative practices lost to the more stable, individual celebrity identity, TAC lost to Minoru Yamasaki. Salomon also argues that the organisational and structural qualities of UA's WTC proposal sought to embed collective operations of multiplicity rather than mere duplication of the previous WTC Twin Towers within the form of the design itself. Copyright © 2006 John Wiley & Sons, Ltd.     

视觉初级皮层区超柱结构的自组织适应模型

在视皮层的初级皮层区中,有许多非常规整的柱形功能结构,它们形成的局域网络具有抽取视图像中最基本的微小特征的能力．视皮层的等级组构为许多心理现象提供了生理解释,这不仅对模式识别、计算机视觉有重要的价值,而且对人工智能系统知识的获取和知识表示都具有非常重要的意义．通过构造一个金字塔状的神经网络层次模型,对模拟视网膜的输入点阵信息进行逐级加工．在计算实现上使用了无监督的自组织语义映射结构,以使模型具有一定的自适应能力．强调的是认知心理功能的计算依托和生理基础．     

基于链路特征的DDoS攻击检测方法

提出了一种基于链路特征的DDoS攻击检测方法,利用极大似然估计技术推出网络内部链路特征分布,应用自组织映射神经网络进行链路特征活动轮廓学习和异常链路检测。实验结果表明,该方法有效,具有一定的发展潜力,对于DDoS攻击的检测和预防具有重要现实意义。