Research on the group decision-making about emergency event based on network technology

In order to improve decision-making efficiency about emergency event, this paper proposes a novel concept, i.e., Agile-Delphi Method, which is an integration of agile decision and Delphi Method implicating that the decision-makers instantly deliver, respond, treat, and utilize information via Delphi process while conducting group decision-making about emergency event. The paper details the mechanism of group decision-making about emergency event based on network technology and Agile-Delphi Method. Finally, the paper conducts an empiric analysis taking the “111 event”, i.e., the liquid ammonia spill event happened on November 1, 2006 in a phosphorus chemical company in China, as an example.     

Fire detection algorithms for video images of large space structures

In large space structures, the latest fire detection methods are based on video image processing and data fusion. But the false positive rate and false negative rate remain unsatisfactory and need improving. The emphases of this paper are target extraction and recognition. A new adaptively updating target extraction algorithm (NAUTEA) is proposed by which the intact target can be extracted in time. In addition, some fire video image recognition algorithms, such as fuzzy neural network (FNN) and FGALSSVM (Fuzzy GALSSVM), are studied and improved. To verify the performance of these algorithms, a prototype system is developed, and a series of algorithm tests on a fire video are conducted. These tests make it clear that, the accurate, robust and real-time fire detection can be realized.     

基于SOA和工作流的数据仓库更新系统

针对数据仓库系统中的异构数据源集成问题和数据仓库更新流程的控制问题,提出一个基于SOA和工作流的数据仓库更新系统,把异构环境下的各个系统作为服务提供者或服务消费者,抽象出标准的功能服务接口,实现了异构平台的系统集成。同时把数据仓库更新过程定义为活动的集合,从逻辑上看作为一个工作流过程,可以根据不同的业务需求进行动态组织,高效地满足用户的需求,提高了更新流程的自动化程度和效率。     

基于HLA的卫星协同仿真系统研究与实现

基于HLA体系规范,研究协同仿真软件体系结构,设计了一个卫星协同仿真系统CSS(Coordinated Simulation System).首先简要介绍了系统研究的意义,以系统功能以及系统要素为基础分析了系统的需求、提出了基于"协同"的设计原则以及系统性能评估指标,然后介绍了实现CSS的关键技术--使命空间的任务体现结构和多分辨率建模技术 ,以及CSS的分层设计的系统结构,并以仿真任务管理成员和卫星成员为例分析了设计CSS联邦成员的设计思路,最后提出了一个原型系统.该系统仿真了卫星侦查、数据通信、数据评估等整个过程对大型复杂系统的仿真具有很好的借鉴意义.     

eXist数据库结构连接算法的改进和实现

为了进一步提高eXist数据库的查询效率,针对数据库现有的数据存储特点和查询策略,提出一种快速定位的结构连接算法FL-Stack。算法采用栈缓存已遍历过的但仍可能与尚未遍历的后代结点匹配的祖先结点,并对能预先判断不可能满足结构连接匹配的祖先或后代结点,提出相应方法实现快速定位,以批量跳过这类结点。与现有算法必须逐个扫描祖先后代结点序列相比,这种快速定位的结构连接算法避免了逐个扫描带来的多次重复无意义的比较,可大大提高结构连接效率。     

JAAS自身的安全性分析

JAAS(Java Authentication and Authorization Service)是Java认证和授权服务的API机制,JAAS的安全性除了体现在认证和授权机制以外,还体现在对Java2平台安全体制的充分利用,分别从认证和授权两个方面对JAAS的安全性作了分析,并结合对Java2平台安全体制的分析,说明JAAS机制是如何充分利用Java语言的灵活性和安全性来保证自身安全性的。     

基于遗传混沌算法的LSSVM参数优化及应用

针对最小二乘支持向量机(LSSVM)存建模中的重要参数如何选择问题.提出利用具有随机性、遍历性及规律性的混沌优化算法对LSSVM建模过程中的参数进行优化搜索,为了加快对较大搜索空间中的搜索速度,提出变尺度混沌优化算法与遗传算法相结合遗传算法的组合算法对LSSVM中的参数优化.组合算法克服了单一算法存在的早熟、局部收敛及寻优速度慢等问题,把混沌变最种群映射到LSSVM参数取值区间.按照遗传算法训练,同时利用训练集训练LSSVM,最终得到参数优化值.将该方法应用的谷氨酸发酵过程的建模研究,取得了较高建模精度,提高发酵过程资源利用率的同时增加了谷氨酸产量.     

Real-time removal of ocular artifacts from EEG based on independent component analysis and manifold learning

Frequent occurrence of ocular artifacts leads to serious problems in interpreting and analyzing the electroencephalogram (EEG). In the present paper, a novel and robust technique is proposed to eliminate ocular artifacts from EEG signals in real time. Independent Component Analysis (ICA) is used to decompose EEG signals. The features of topography and power spectral density of those components are extracted. Moreover, we introduce manifold learning algorithm, a recently popular dimensionality reduction technique, to reduce the dimensionality of initial features, and then those new features are fed to a classifier to identify ocular artifacts components. A k-nearest neighbor classifier is adopted to classify components because classification results show that manifold learning with the nearest neighbor algorithm works best. Finally, the artifact removal method proposed here is evaluated by the comparisons of EEG data before and after artifact removal. The results indicate that the method proposed could remove ocular artifacts effectively from EEG signals with little distortion of the underlying brain signals and be satisfied the real-time application.     

Preventive maintenance scheduling for repairable system with deterioration

Maintenance as an important part in manufacturing system can keep equipment in good condition. Many maintenance policies help to decrease the unexpected failures and reduce high operational cost such as conventional preventive maintenance. But these conventional preventive maintenance policies have the same time interval T that may easily neglect system’s reliability, because the system deteriorates with increased usage and age. Hence, this study has developed a reliability-centred sequential preventive maintenance model for monitored repairable deteriorating system. It is supposed that system’s reliability could be monitored continuously and perfectly, whenever it reaches the threshold R, the imperfect repair must be performed to restore the system. In this model, system’s failure rate function and operational cost are both considered by the effect of system’s corresponding condition, which helps to decide the optimal reliability threshold R and preventive maintenance cycle number. Finally, through case study, the simulation results show that the improved sequential preventive maintenance policy is more practical and efficient.     

Robust observer–controller compensator design using the loop shaping design procedure and the algebraic method

This paper investigates robust observer‐controller compensator design using Vidyasagar's structure (VS). VS has a unit matrix parameter H similar to the Q parameter for the Youla–Kucera parameterization. VS can be designed based on the left coprimeness of the central controller in the H_∞‐loop shaping design procedure (H_∞‐LSDP) and therefore can preserve the intrinsic properties of the H_∞‐LSDP. This paper introduces algebraic methods to simplify the design of H in the VS controller by solving specific algebraic equations. In particular, the algebraic design of H can achieve two things. First, a dynamic H adjusts the tracking performance and yields the integral action. Second, a dynamic H rejects the input and output sinusoidal disturbances with known frequencies. These attributes are indications of the flexibility of the proposed method since the output‐feedback controller design of the H_∞‐LSDP cannot easily deal with such conditions. This paper discusses the achieved loop and the closed‐loop behavior of the system with VS, and also gives two numerical examples. The first example shows that the proposed method results in a better design in many aspects than the resulting from H_∞‐LSDP. The second example shows the application of the proposed method to rejecting input and output step disturbances, and input and output multiple sinusoidal disturbances, for which the H_∞‐LSDP can hardly be used. Copyright © 2009 John Wiley & Sons, Ltd.