集成状态监测和故障诊断的设备管理系统

提出了离线和在线监测诊断相结合的状态维修策略,在状态维修思想的指导下,建立了系统的工作模型和功能模型。综合采用网络技术、计算机技术和数据库技术等开发出了集成状态监测和故障诊断的设备管理系统,为企业开展状态维修提供了有效的管理工具。     

On-line failure prediction in safety-critical systems

In safety-critical systems such as Air Traffic Control system, SCADA systems, Railways Control Systems, there has been a rapid transition from monolithic systems to highly modular ones, using off-the-shelf hardware and software applications possibly developed by different manufactures. This shift increased the probability that a fault occurring in an application propagates to others with the risk of a failure of the entire safety-critical system. This calls for new tools for the on-line detection of anomalous behaviors of the system, predicting thus a system failure before it happens, allowing the deployment of appropriate mitigation policies.The paper proposes a novel architecture, namely CASPER, for online failure prediction that has the distinctive features to be (i) black-box: no knowledge of applications internals and logic of the system is required (ii) non-intrusive: no status information of the components is used such as CPU or memory usage; The architecture has been implemented to predict failures in a real Air Traffic Control System. CASPER exhibits high degree of accuracy in predicting failures with low false positive rate. The experimental validation shows how operators are provided with predictions issued a few hundred of seconds before the occurrence of the failure.     

A framework for effective management of condition based maintenance programs in the context of industrial development of E-Maintenance strategies

CBM (Condition Based Maintenance) solutions are increasingly present in industrial systems due to two main circumstances: rapid evolution, without precedents, in the capture and analysis of data and significant cost reduction of supporting technologies. CBM programs in industrial systems can become extremely complex, especially when considering the effective introduction of new capabilities provided by PHM (Prognostics and Health Management) and E-maintenance disciplines. In this scenario, any CBM solution involves the management of numerous technical aspects, that the maintenance manager needs to understand, in order to be implemented properly and effectively, according to the company’s strategy. This paper provides a comprehensive representation of the key components of a generic CBM solution, this is presented using a framework or supporting structure for an effective management of the CBM programs. The concept “symptom of failure”, its corresponding analysis techniques (introduced by ISO 13379-1 and linked with RCM/FMEA analysis), and other international standard for CBM open-software application development (for instance, ISO 13374 and OSA-CBM), are used in the paper for the development of the framework. An original template has been developed, adopting the formal structure of RCM analysis templates, to integrate the information of the PHM techniques used to capture the failure mode behaviour and to manage maintenance. Finally, a case study describes the framework using the referred template.     

Intelligent system architecture for process operation support

This paper presents a generic intelligent system platform, namely INTEMOR (INTElligent Multimedia system for On-line Real-time application), for process operation support. INTEMOR is developed by combining artificial intelligence, computer system and information technology into a unified environment. It integrates various function modules to perform operation support tasks, including communication gateway, data processing and analysis, on-line process monitoring and diagnosis, on-line operation manual, equipment maintenance assistance, reasoning system, knowledge-base creator and multimedia interface. The industrial applications of INTEMOR on a boiler system and a chemical pulping process are illustrated.     

Embedded holonic fault diagnosis of complex transportation systems

The use of electronic equipment and embedded computing technologies in modern complex transportation systems continues to grow in a highly competitive market, in which product maintainability and availability is vital. These technological advances also make fault diagnosis and maintenance interventions much more challenging, since these operations require a deep understanding of the entire system. This paper proposes a holonic cooperative fault diagnosis approach, along with a generic architecture, to increase the embedded diagnosis capabilities of complex transportation systems. This concept is applied to the fault diagnosis of door systems of a railway transportation system.     

基于多层架构的ASP .NET 4 MVC 框架研究

ASP.NET MVC 框架是微软今后开发Web 应用程序的一个主流技术。本文介绍了如何将一个基于多层架构、 ASP.NET 4 技术的Web Forms 应用迁移为多层架构的ASP.NET 4 MVC 框架应用。从多层架构的角度出发,深入剖析了MVC 模式工作原理,并给出了一个多层架构的ASP.NET 4 MVC 客户关系管理系统实例。     

基于．NET和MVC相结合的训练用器材管理系统的设计与实现

研究了MVC（Model-View-Controller）设计模式及．NET架构,在此基础上,提出了．NET框架下的MVC应用方案,将该方案应用到训练用器材管理系统的设计中。对训练用器材管理系统的功能模块、体系结构及数据库进行了详细设计,阐述了系统实现过程。     

武器装备基于状态的维修系统设计

为了减少武器装备的故障以及维修时间,提高武器装备的可用度和重要部件的使用寿命,采用基于状态的维修技术与方法已成为当前维修领域研究与应用的热点.从武器装备的维修需求与技术出发,分析了现行装备维修的主要方式及其优缺点,总结了当前基于状态的维修(CBM)研究与应用现状,在此基础上提出了武器装备基于案例的CBM系统框架,给出了CBM适用的条件,并对CBM系统的核心模块进行了分析,给出了CBM系统工作的流程.最后,结合某装备中一齿轮箱的状态检测信息,进行了基于声音的装备故障诊断与案例分析与决策.分析结果表明:基于案例的CBM系统简单实用,能够满足装备维修需求.     

A generic rendering system

Describes the software architecture of a rendering system that follows a pragmatic approach to integrating and bundling the power of different low-level rendering systems within an object-oriented framework. The generic rendering system provides higher-level abstractions to existing rendering systems and serves as a framework for developing new rendering techniques. It wraps the functionality of several widely-used rendering systems, defines a unified object-oriented application programming interface and provides an extensible, customizable apparatus for evaluating and interpreting hierarchical scene information. As a fundamental property, individual features of a specific rendering system can be integrated into the generic rending system in a transparent way. The system is based on a state machine, called an "engine", which operates on "rendering components". Four major categories of rendering components constitute the generic rendering system: "shapes" represent geometries, "attributes" specify properties assigned to geometries and scenes, "handlers" encapsulate rendering algorithms, and "techniques" represent evaluation strategies for rendering components. As a proof of concept, we have implemented the described software architecture using the Virtual Rendering System, which currently wraps the functionality of the OpenGL, Radiance, POV Ray and RenderMan systems     

Software fault prediction using particle swarm algorithm with genetic algorithm and support vector machine classifier

Software fault prediction is a process of developing modules that are used by developers in order to help them to detect faulty classes or faulty modules in early phases of the development life cycle and to determine the modules that need more refactoring in the maintenance phase. Software reliability means the probability of failure has occurred during a period of time, so when we describe a system as not reliable, it means that it contains many errors, and these errors can be accepted in some systems, but it may lead to crucial problems in critical systems like aircraft, space shuttle, and medical systems. Therefore, locating faulty software modules is an essential step because it helps defining the modules that need more refactoring or more testing. In this article, an approach is developed by integrating genetics algorithm (GA) with support vector machine (SVM) classifier and particle swarm algorithm for software fault prediction as a stand though for better software fault prediction technique. The developed approach is applied into 24 datasets (12-NASA MDP and 12-Java open-source projects), where NASA MDP is considered as a large-scale dataset and Java open-source projects are considered as a small-scale dataset. Results indicate that integrating GA with SVM and particle swarm algorithm improves the performance of the software fault prediction process when it is applied into large-scale and small-scale datasets and overcome the limitations in the previous studies.     

基于SOAP协议的统一身份认证服务设计与实现

企业门户系统的目标是消除企业信息孤岛,无缝集成各种应用系统并实现统一身份认证。运用SOAP的消息机制和Web Services的核心概念及运行机制,提出了基于SOAP协议的统一身份认证系统架构,解决了集成新旧系统时出现的关键问题。采用.NET技术实现了原型系统,实现了用户统一身份认证,从而完成了在异构平台、异构数据库下的企业数据流、应用流的全面集成。     

基于ASP．NET应用系统网络安全机制的研究

随着用户应用系统和网络环境的日益复杂,安全威胁日益增多。作为微软．NET框架的组成部分,ASP．NET使得构建安全的Web应用程序更加容易。本文重点探讨基于ASP．NET技术开发Web应用系统的安全问题,介绍基于ASP．NET平台B／S架构的应用系统网络安全的设计,分析B／S三层网络架构的安全机制,给出了通过身份验证、权限控制、数据加密、存储过程访问数据库等手段实现系统的安全性的技术要点。     

Equipment PHM using non-stationary segmental hidden semi-Markov model

Health monitoring and prognostics of equipment is a basic requirement for condition-based maintenance (CBM) in many application domains where safety, reliability, and availability of the systems are considered mission critical. As a key complement to CBM, prognostics and health management (PHM) is an approach to system life-cycle support that seeks to reduce/eliminate inspections and time-based maintenance through accurate monitoring, incipient faults. Conducting successful prognosis, however, is more difficult than conducting fault diagnosis. A much broader range of asset health related data, especially those related to the failures, shall be collected. The asset health progression can then be possibly extracted from the congregated data, which has proved to be very challenging. This paper presents a non-stationary segmental hidden semi-Markov model (NSHSMM) based prognosis method to predict equipment health. Unlike previous HSMMs, the proposed NSHSMM no longer assumes that the state-dependent transition probabilities keep the same value all the time. That is, the probability of transiting to a less healthy state does not increase with the age. “Non-stationary” means the transition probabilities will change with time. In the proposed method, in order to characterize a deteriorating equipment, three kinds of aging factor that discount the probabilities of staying at current state while increasing the probabilities of transitions to less healthy states are introduced. The performances of these aging factors are compared by using historical data colleted from three hydraulic pumps. The hazard function (h.f.) has been introduced to analyze the distribution of lifetime with a combination of historical failure data and on-line condition monitoring data. Using h.f., PHM is based on a failure rate that is a function of both the equipment age and the equipment conditions. The state values of the equipment condition considered in PHM, however, are limited to those stochastically increasing over time and those having non-decreasing effect on the hazard rate. The estimated state duration probability distributions can be used to predict the remaining useful life of the systems. With the equipment PHM, the behavior of the equipment condition can be predicted.     

一个领域软件集成框架的研究与实现

文章论述了领域开放软件集成框架的设计思想、目标和标准体系,研究了实现领域软件数据共享,即插即用和 构筑虚拟应用的技术思路,给出了一个石油软件集成框架系统,介绍了它的功能、体系结构和核心模块的实现。     

Diagnosing multiple intermittent failures using maximum likelihood estimation

In fault diagnosis intermittent failure models are an important tool to adequately deal with realistic failure behavior. Current model-based diagnosis approaches account for the fact that a component cj may fail intermittently by introducing a parameter gj that expresses the probability the component exhibits correct behavior. This component parameter gj, in conjunction with a priori fault probability, is used in a Bayesian framework to compute the posterior fault candidate probabilities. Usually, information on gj is not known a priori. While proper estimation of gj can be critical to diagnostic accuracy, at present, only approximations have been proposed. We present a novel framework, coined Barinel, that computes estimations of the gj as integral part of the posterior candidate probability computation using a maximum likelihood estimation approach. Barinel's diagnostic performance is evaluated for both synthetic systems, the Siemens software diagnosis benchmark, as well as for real-world programs. Our results show that our approach is superior to reasoning approaches based on classical persistent failure models, as well as previously proposed intermittent failure models.     

Implementing a generic component‐based framework for telecontrol applications

The rapid growth of telecontrol systems is one of the major trends in today's network‐oriented community. The implementation of generic frameworks, consisting of reusable components that can form the basis for the development of such systems, is a necessity. There is a plethora of associated applications that can be developed in a distributed environment, such as audio/video teleconferencing, groupware and collaborative computing environments, remote controlled services, etc. In this paper we design and implement a generic framework of components that can be used for the realization of telecontrol applications. This category of applications focuses primarily on the issues of managing distributed units on remote end‐systems. Such applications contain remote units and administrators that are connected and exchange data and control messages. We analyse the outlined architecture of our framework and the most important system operations. We also describe the communication protocol used in message exchanges between the constituent components. Finally, we illustrate the usefulness of our framework by presenting two applications that were created by extending the basic software infrastructure. Copyright © 2007 John Wiley & Sons, Ltd.     

Health monitoring of vibration signatures in rotorcraft wings

We propose to design and to evaluate an on-board intelligent health assessment tool for rotorcraft machines, which is capable of detecting, identifying, and accommodating expected system degradations and unanticipated catastrophic failures in rotorcraft machines under an adverse operating environment. A fuzzy-based neural network paradigm with an on-line learning algorithm is developed to perform expert advising for the ground-based maintenance crew. A hierarchical fault diagnosis architecture is advocated to fulfill the time-critical and on-board needs in different levels of structural integrity over a global operating envelope. The research objective is to experimentally demonstrate the feasibility and flexibility of the proposed health monitoring procedure through numerical simulations of bearing faults in USAF MH-53J PAVELOW helicopter transmissions. The proposed fault detection, identification and accommodation architecture is applicable to various generic rotorcraft machines. The proposed system will greatly reduce the operational and developmental costs and serve as an essential component in an autonomous control system.     

Conceptual design of remote monitoring and fault diagnosis systems

Condition monitoring and fault diagnosis are of fundamental importance for many industrial systems. In the last decade, substantial research efforts have been made on the surveillance and diagnosis systems for different types of equipment, with the approach of integrating information technologies and intelligent computing methods. This paper presents the conceptual design of a distributed information system of condition monitoring and fault diagnosis for a growing number of gas turbine-based power generation systems. Each individual information system that monitors a specific gas turbine system, locally deployed in a power plant, is linked to another information system, deployed at the manufacturer's site, which oversees all the gas turbine systems in parallel. The systems are constructed on the basis of COM components, which are conceptually separated into three tiers. Subsequently, this paper proceeds to present a generic business domain model with components encapsulating physical entities of interest. Finally, this paper addresses the interactions among components, which considerably affect the performance of the system including efficiency and effectiveness. It has been identified that both asynchronous and synchronous communication mechanisms are required for exchanging information for different scenarios. COM+ services are also required for supporting object pooling, transaction coordination, and security control.     

基于.NET平台的WEB解决方案的安全机制

安全是Web应用的核心。许多Web应用基于Windows的IIS服务，其安全控制全面集成于Windows安全体系，提供了包括多种措施在内的安全机制。然而，IIS安全机制过于简单，因此，NET平台对基于其ASP.NET环境开发的Web应用引入了更多的安全措施。ASP.NET安全机制与IIS安全机制协同工作，大大提高了IIS的安全性，更好地解决了Web应用的安全问题。开发人员可以根据不同的安全需求，按需定制，构造多层次的安全解决方案。