Industrial application of multivariate SPC to continuous caster start-up operations for breakout prevention

Breakouts are of major concern in the continuous steel-casting process, because they can lead to severe damage to equipment, significant process downtime, and potential safety consequences. Dofasco's plant experiences show that approximately 25% of breakouts occur during the caster start-up operation. This paper describes an advanced industrial application of the Multiway Principal Component Analysis (MPCA) method to monitor continuous caster start-up operations in real time and to prevent breakout occurrences and other start-up process failures. The online monitoring system has been successfully commissioned at Dofasco's No. 2 Continuous Caster. Two operational examples are included in this paper to demonstrate the improved economic performance.     

Model-based computer-aided design environment for operational design

To meet the increasing market challenges in chemical industry, it is imperative to improve process design and the supportive computer-aided engineering tools so that they can support lifecycle activities. This research work proposes detailed mechanism of operational design approach on the basis of operational design modeling methodology where lifecycle activities are considered during design stage. Computer-aided design environment called CAPE-CAD is proposed, which supports operational design approach. CAPE-CAD encompasses a friendly user interface to capture and maintain plant topology and to link process behaviors and plant operations with corresponding plant structure units. The proposed design environment can be used during design and operation stages, as well as for operator training. Case study of chemical process is used to explain the proposed solution.     

A Quasi-Experimental Model of Complex Human–Machine System Validation

Complex systems, such as power plants and commercial aircraft, are designed to operate safely under normal and disturbance conditions. Integrated-system validation is one means to evaluate whether safety and productivity goals can be achieved prior to actual operation. While some types of systems can be tested in an actual operational environment, validation is especially difficult when safety or economic considerations preclude testing in the disturbance conditions they are designed to handle. This paper proposes a conceptual model for integrated-system validation based on an integration of current approaches to design validation and concepts adopted from quasi-experimental research methodology. The model identifies important validation principles and the methodological considerations needed to support a logical and defensible inference to be made from validation tests to system performance under actual operating conditions. Central to the model are four general forms of validity: system representation, performance representation, test design and statistical conclusion validity. Threats to the inference process and weakness of the model are also discussed.     

基于分级缓存加速的高可靠高速星载固存设计

星上模块在模式切换过程会因为星载固态存储器启动过程缓慢而导致无法快速访问固存。分级缓存系统设计采用片内缓存结合小容量非易失存储器(MRAM)的硬件架构,通过在MRAM中存储文件对象头索引以及Nand Flash块元数据区索引等流程优化来加速文件系统启动操作。本设计通过数据建模和仿真实验来分析性能,并在硬件板卡上进行算法实现和测试验证,以对象为索引的启动方式耗时3.12 ms,以块元数据区为依据的启动方式耗时143.47 ms。对比传统设计架构下的耗时170.35s的启动操作,基于分级缓存加速的系统具有高可靠性同时大大缩短了固存启动时间。其系统性能提升为卫星在轨管控优化提供技术基础。     

航天发射系统运行安全性评估研究进展与挑战

航天发射作为人类太空活动最为基础和最为重要的环节之一,是评判一个国家综合国力的重要指标,而航天发射系统运行安全性评估作为现代航天发射控制指挥与决策系统的核心,是保证航天发射安全运行的基础.首先,本文概述了现代航天发射系统,简要回顾了系统安全性研究发展历程,阐述了航天发射系统运行安全性评估的内涵.其次,通过综述航天发射系统运行故障检测与诊断、异常运行工况识别、运行过程安全分析与预测、安全性动态评估技术等方面的研究现状的基础上,总结出了航天发射系统运行安全性评估面临着系统极度复杂、决策风险性极大、先验信息少以及评估结果要求高准确性与实时性等方面的挑战.最后,本文对航天发射系统运行安全性评估有待研究的基础前沿问题进行了思考.     

特征设计的形式化描述

特征设计方法在设计中的成功应用取决于其形式化设计理论的建立。文章从形式化定义和设计过程描述这两个方面研究了特征设计的形式化描述方法。文中提出了特征定义、特征表示的形式化方法,探讨了特征设计过程的操作性和过程性描述,并给出了相应的设计算法。为解决特征设计系统开发和运行缺乏统一方法学这一课题作了有益的尝试。     

A neural network-based preset generation tool for a steel tandem cold mill

This paper traces the development of a software tool, based on a combination of artificial neural networks (ANN) and a few process equations, aiming to serve as a backup operation instrument in the reference generation for real-time controllers of a steel tandem cold mill. By emulating the mathematical model responsible for generating presets under normal operational conditions, the system works as an option to maintain plant operation in the event of a failure in the processing unit that executes the mathematical model. The system, built from the production data collected over six years of plant operation, steered to the replacement of the former backup operation mode (based on a lookup table), which degraded both product quality and plant productivity. The study showed that ANN are appropriated tools for the intended purpose and that by this instrument it is possible to achieve nearly the totality of the presets needed by this kind of process. The text characterizes the problem, relates the investigated options to solve it, justifies the choice of the ANN approach, describes the methodology and system implementation and, finally, shows and discusses the attained results.     

方家山核电工程仪控系统调试的典型问题分析

解决现场调试问题,首先要找到问题根源,理清设计、系统运行、试验方法等的上下游之间的关联,结合现场情况制定最佳解决方案。更好、更高效地解决现场出现的问题,来自于对现场情况的充分了解与调试备方的充分沟通,本文列举了一些系统调试出现的问题并详细论述了问题的解决过程。     

基于数据挖掘的现场作业风险态势评估方法

为保障电网安全稳定运行,减少生产安全事故,供电企业针对大量的基建、生产运行作业开展现场安全管理,积累了海量作业管理及安全管理业务数据。为更好地应用这些数据,使其真正为供电企业作业风险预警及防控服务,在梳理供电企业现场作业全过程的数据基础上,对作业风险态势要素历史数据进行分析,识别出人、机、料、法、环境和管理等风险影响因素,从人员、设备（机械）、材料工器具、作业方法、作业环境与时间管理6个维度构建现场作业风险评估指标体系及作业安全态势指数模型,结合信息技术,开展风险态势智能评估的工具设计。     

Development of a systematic checklist for the human factors evaluation of the operator aiding system in a nuclear power plant

In the safety systems review of the Korean nuclear power plants, the Human Factors Program Plan for the OAS (Operator Aiding System) has been executed mainly by an expert review. The reviewers had to integrate all the relevant sources of information and make judgement based on their own criteria. Consistency and thoroughness of this process was always in question and a systematic approach to correct these problems was in need. The purpose of this work was to design a methodology for supporting an effective and efficient ergonomic evaluation of the user interface of the OAS. By collecting and systematically structuring all the critical considerations in the human factors review process, an ergonomic evaluation checklist for the CFMS (Critical Function Monitoring System) in an MCR (Main Control Room) was designed and implemented in this study. Application of the developed checklist was used during the licensing review process for the CFMS of the Ulchin unit 3&4. Efficiency and effectiveness of the human factors review process was enhanced significantly with the aid of the integrated checklist and the standardized evaluation format developed in this study.

Relevance to industry

Human factors review process is an integral component of the safety of a nuclear power plant. The methods and procedures developed in this study will provide valuable support for the enhancement of the safety and usability of the human interface of the nuclear power plant.     

Integration techniques in intelligent operational management: a review

Until recently the concept of an integrated framework for coordinating operational tasks in industrial plants has not been possible due to technological limitations. Integration of functions within an intelligent system architecture would result in improved plant performance, safety and an increase in production. As a result of increased computing power and powerful memory systems, a fully computer integrated system is now possible, however, achieving an integrated framework for operational tasks is quite complex. Problems of task integration include not only the consideration of information flow and timing for a continuously changing environment, but the integration of various problem-solving methodologies. Integration frameworks proposed in the past fail to provide for a fully integrated system. A new approach to accommodate the changing dynamics of a plant's operation is now possible with the Coordinated Knowledge Management method.This paper reviews the components that need to be integrated to encompass intelligent process operation. It also reviews various integration frameworks outlining limitations and presents a proposed method of integration based on knowledge management.     

Design of a PCB plant with expert system and simulation approach

This paper presents a case study of using simulation in planning a new Printed Circuit Board (PCB) manufacturing system. The process simulation technique and expert system are proposed to evaluate the design alternatives and logistics management. Simulation results, such as machine utilisation, waiting time, and throughput of system are generated for evaluation. Simulation models were developed using software package SIMPROCESS, which is based on the concept of visual interactive simulation. Besides, the formation of the models is assisted by the expert system package VP-EXPERT. Each approach was found to accurately model the PCB manufacturing plant layout, provide operational and logistics performance in terms of throughput, waiting time, and resource utilisation, and provide a basis for suggesting the best modes of logistics operation.     

面向仿真系统的自动测评关键技术研究

面向仿真系统的自动测评通常有基于操作结果和基于操作序列两种方式。基于操作序列的测评方式虽然复杂,但能够全面、客观地反映考生实践操作技能。本文重点介绍操作序列通用框架的表示问题,在此基础上,建立基于专家系统的操作测评模型和实操考核自动评分流程,最后给出自动测评关键技术在航海仪器测评系统中的实际应用,实现了评分结果的相对客观、公正,大大提高了实操考核的工作效率。     

A hybrid methodology for restructuring decision of a manufacturing system: A case study

The output performance of a manufacturing system depends on its operational continuity. However, a manufacturing system can stop for a short time or it can be out of service for a long time due to crucial problems such as poor performance of old machines, unexpected breakdowns or faulty plant and system design. Many firms try to restructure their manufacturing systems to avoid these crucial problems and to be more efficient, profitable and better organized. However, the decision to begin the process of restructuring is a difficult and critical choice for most decision makers due to the fact that the decision threshold of the process is ambiguous. This paper proposes a hybrid methodology for the decision makers who will decide on restructuring a manufacturing system. The proposed methodology provides crucial information for the decision makers combining fuzzy logic approach and reliability analysis.     

基于LabVIEW的PID锅炉温控补水系统的设计与实现

锅炉补给水系统是电厂安全运行的重要辅助系统,其补水技术直接影响到机组的平稳、可靠运行。基于LabVIEW的锅炉温控补水系统旨在通过采集锅炉内水温,并将数据转换为水量值送至LabVIEW软件,通过实时显示、分析和处理实现对锅炉容水量的控制。系统的设计具有人机交互性强、控制精度高、稳定性好、使用方便等优点。     

Computer-aided RCM-based plant maintenance management system

In most of the industries, classical reliability-centered maintenance (RCM) is employed to decide the maintenance strategies using reliability data without having adequate interaction with the design and operational systems. This means that the RCM process will be conducted with no or limited access to the design and operational data/knowledge. Commonly, the developed maintenance strategies are implemented and managed within the computerized maintenance management system (CMMS), which is usually separate from the RCM automated environment. This paper presents the detailed system design and mechanism of improved RCM process as integrated with CMMS. The proposed solution is integrated with design and operational systems and consolidates some successful maintainability approaches to formulate an effective solution for optimized plant maintenance. The major components of the enhanced RCM process are identified and a prototype system is implemented as integrated with the various modules of the adopted CMMS (MAXIMO™). A case study is used to show the effectiveness of the proposed RCM-based CMMS solution in optimizing plant maintenance over the traditional approaches.     

An ergonomic comparison of firearm safety mechanisms

As with most machines, the integral safety mechanism on firearms is vital to injury or fatality free operation. Presently, there is little or no standardisation in the design of these mechanisms. In this investigation, five existing designs found on both military and commercial rifles were evaluated ergonomically to determine the most effective characteristics for incorporation into future designs. The designs were evaluated experimentally on ease of use, visual effectiveness and operational impact. Three groups, representing a total of 30 subjects with widely varying experience, were selected. Results strongly suggest that safeties whose actuators are mounted within easy reach of the trigger finger are preferred and have the least operational impact. Subjects also preferred and were more adept at recognising safety status when the indicator was located on the receiver/barrel along the normal line of sight. Subjects more often correctly identified safety status when the indicator utilised colouring, was clearly marked and/or was in the normal line of sight. The results of this research prove that ergonomics can contribute to the understanding of firearm safety dynamics. The two essential components of safety mechanism design identified in this investigation, unambiguous status visibility and impact-free operation, are also likely to have implications in non-firearm safety mechanism design. This is particularly true for devices whose inadvertent operation can cause injury, as well as systems in which operational effectiveness can be jeopardised when attentiveness or operational control are lost in the process of actuating a poorly designed safety mechanism.     

An ergonomic comparison of firearm safety mechanisms

As with most machines, the integral safety mechanism on firearms is vital to injury or fatality free operation. Presently, there is little or no standardisation in the design of these mechanisms. In this investigation, five existing designs found on both military and commercial rifles were evaluated ergonomically to determine the most effective characteristics for incorporation into future designs. The designs were evaluated experimentally on ease of use, visual effectiveness and operational impact. Three groups, representing a total of 30 subjects with widely varying experience, were selected. Results strongly suggest that safeties whose actuators are mounted within easy reach of the trigger finger are preferred and have the least operational impact. Subjects also preferred and were more adept at recognising safety status when the indicator was located on the receiver/barrel along the normal line of sight. Subjects more often correctly identified safety status when the indicator utilised colouring, was clearly marked and/or was in the normal line of sight. The results of this research prove that ergonomics can contribute to the understanding of firearm safety dynamics. The two essential components of safety mechanism design identified in this investigation, unambiguous status visibility and impact-free operation, are also likely to have implications in non-firearm safety mechanism design. This is particularly true for devices whose inadvertent operation can cause injury, as well as systems in which operational effectiveness can be jeopardised when attentiveness or operational control are lost in the process of actuating a poorly designed safety mechanism.     

Methodology for Business System Development

The methodology presented here is currently being used in the design of Standard Automated Financial System (STAFS), which is a large scale business system for use by the 14 Naval Laboratories across the nation. The system will be operational in 1987-1988 time-frame. The methodology presented is suitable for all transaction oriented systems. It enforces documentation of design at all levels of system development process allowing managers and users a high visibility into the design. It highlights the human engineering aspects of system design and utilizes thread definition, data designer, and structured design techniques. The methodology requires the use of system verification diagrams which specify the user requirements. The design produces an integrated database with security mechanisms to restrict unauthorized users from accessing data they are not authorized to use. The threads also serve as a useful tool for system testing.