Synthesis of the web-based CAD viewer for interference verification of injection moulds

This paper describes the development of a web-based interference examination system in mould design processes. Although several commercial computer-aided design (CAD) systems offer interference inspection functions, those systems are very expensive and inadequate to perform collaborative works over the Internet. In this paper an efficient and precise hybrid interference examination algorithm applicable to multilevel assemblies is studied for injection mould design processes. In order to design a collaborative system over the distributed environment, lightweight CAD files produced from the optimally transformed CAD data through ACIS kernel and InterOp are applied to develop a web-based interference verification system. Collaborators related to the development of a new product can verify the interference over the Internet without commercial CAD systems. The system reduces production cost, errors and lead-time to the market. The validity of the developed system is confirmed through case studies.     

Development of a safety critical software requirements verification method with combined CPN and PVS: a nuclear power plant protection system application

Safety-critical software systems such as certain nuclear instrumentation and control (NI&C) systems should be developed with thorough verification. This study presents a method of software requirement verification with a case study for a nuclear power plant (NPP) protection system. The verification introduces colored petri net (CPN) for system modeling and prototype verification system (PVS) for mathematical verification. In order to aid flow-through from modeling by CPN to mathematical proof by PVS, an information extractor from CPN models has been developed in this paper. In order to convert the extracted information to the PVS specification language, a translator has also been developed. This combined method has been applied to the functional requirements of the Wolsong NPP Shut Down System #2 (SDS2); logical properties of the requirements were verified. Through this research, guidelines and a tool support for the use of formal methods have been developed for application to NI&C software verification.     

活塞式热量表检定系统研究

提出了一种基于活塞式体积管的新型热量表动态检定技术.阐述了热量表检定装置的工作原理,设计了一种以工控机为控制核心,在VC++环境下进行数据自动采集及过程控制,实现检定参数实时准确测试的高精度热量表检定系统,从理论上分析了影响热量表热水流量检测系统的不确定度因素.研究表明,相对于现有的以质量法结合标准表法的热量表检定方法,本方案能有效提高热量表检定效率和精度.     

数字多用表自动检定系统的组建

介绍基于GPIB总线,使用LabVIEW软件开发的数字多用表自动检定系统。重点介绍了系统的软硬件实现方法。通过实际应用证明该系统在数据采集、数据处理、保存、生成证书报告等方面都具有优良的性能,大大提高工作效率,并确保检定的准确性。     

Development of a collaborative product development framework based on centre-satellite system and service-oriented architecture

To increase competitive advantage for manufacturers, collaboration product development (CPD) has recently become an important issue. Based on the CPD concept, this study focuses on the centre-satellite system (CSS) with five major roles (i.e. centre factory) and their interactions and the technology of web services using service-oriented architecture (SOA) to propose a system framework, entitled the collaborative product development framework for centre satellite system (CPDF-CSS). The CPDF-CSS comprises five modules: CF-MA module, DH-MA module, ODM-MA module, OEM-MA module, and EC-MA module. Next, based on the CPDF-CSS, a generic communication component (GCC) is designed for the interoperability among five modules under heterogeneous contexts. Finally, this study presents a case involving the motorcycle industry for evaluating the implementation of CPDF-CSS. The contributions of this study to the CPD are discussed.     

Verification of three‐dimensional anisotropic adaptive processes

A verification methodology for adaptive processes is devised. The mathematical claims made during the process are identified and measures are presented in order to verify that the mathematical equations are solved correctly. The analysis is based on a formal definition of the optimality of the adaptive process in the case of the control of the L^∞‐norm of the interpolation error. The process requires a reconstruction that is verified using a proper norm. The process also depends on mesh adaptation toolkits in order to generate adapted meshes. In this case, the non‐conformity measure is used to evaluate how well the adapted meshes conform to the size specification map at each iteration. Finally, the adaptive process should converge toward an optimal mesh. The optimality of the mesh is measured using the standard deviation of the element‐wise value of the L^∞‐norm of the interpolation error. The results compare the optimality of an anisotropic process to an isotropic process and to uniform refinement on highly anisotropic 2D and 3D test cases. Copyright © 2011 John Wiley & Sons, Ltd.     

有毒有害气体报警器智能检定装置的研制

为提高检定的准确度和工作效率,保障工作人员的健康,综合运用自动配气技术、图像采集与识别技术、远程控制技术和检定信息系统等,研制一套有毒有害气体报警器智能检定装置.该装置配气精度达到±1％,图像采集识别率达100％,数据处理系统平均响应时间小于5s,具备遥控操作控制功能,提供开放的数据通信接口,能够自动生成、核验、批准和打印检定证书,具有较好的实用价值.     

The multi-load method of determining discrete system parameters in a loaded three dimensional photoelastic model

The determination of the secondary principal stress difference and their orientations for a discrete slice of thickness dz along a particular light path in a loaded three dimensional photoelastic model is discussed in this paper. It is well known that once the geometry of the loaded member and the geometry of loading on the member are fixed, the secondary principal stress directions at any particular point along any line of consideration remain constant. The secondary principal stress values will get multiplied by the factor through which the loading on the component is increased. This has been made use of in the present method and from the characteristic parameters obtained at the end of any light path for different loadings on the three dimensional model, the secondary principal stress difference and their orientations are obtained. The method proposed is a fully non-destructive method of testing and involves measurements only on a transmission polariscope.     

UML时间顺序图的自动验证技术

UML顺序图反映对象之间的消息交互顺序,在系统建模中应用十分广泛.对顺序图进行时间扩展得到UML时间顺序图,使其具备对实时系统建模的能力.在此基础上研究了UML建模工具和模型验证工具UPPAAL的接口信息,将UML时间顺序图模型转化为时间自动机模型,并对该系统模型进行形式化验证.设计和实现了基于XML的UML时间顺序图自动验证工具.     

Formal verification of functional properties of a SCR-style software requirements specification using PVS

Industrial software companies developing safety-critical systems are required to use rigorous safety analysis techniques to demonstrate compliance to regulatory bodies. In this paper, we describe an approach to formal verification of functional properties of requirements for an embedded real-time software written in software cost reduction (SCR)-style language using PVS specification and verification system. Key contributions of the paper include development of an automated method of translating SCR-style requirements into PVS input language as well as identification of property templates often needed in verification. Using specification for a nuclear power plant system, currently in operation, we demonstrate how safety demonstration on requirements can be accomplished while taking advantage of assurance provided by formal methods.     

GenExtractor:基于Web的基因信息挖掘

开发了基于Web的基因信息挖掘系统--GenExtractor,它通过自动连接生物数据库,按照指定的染色体区域寻找候选基因,搜集并集成相关信息,为科研人员检索生物数据库和查找候选基因提供了一个有效的工具.该系统能够在更加精细的染色体区域内对指定功能基因进行查找,并对关键词的要求比较宽泛.经测试,其平均查准率达到60%,平均查全率达到82.1%.     

Experimental verification and application of a practical corrosion model for uniformly depassivated steel in concrete

A practical corrosion model for predicting the corrosion rate of uniformly depassivated steel in concrete was previously developed. The model is built on Stern’s earlier work that an optimum anode-to-cathode ratio exists on the steel surface for which the corrosion current reaches a maximum value. Based on this principle, analytical and numerical techniques were used to obtain a relationship among the steel corrosion rate, concrete resistivity, the oxygen concentration on the surface of the member, oxygen diffusion coefficient, and cover thickness. The main objective of this paper is to present an extensive experimental verification and application of the developed model. For this purpose, three experimental programs carried out by other research groups were selected. The first set of data was used in the verification of the model when different types of cement are used in concrete. The second study was selected to verify the model with the measured corrosion rates obtained by different instruments to eliminate any concerns that may originate from the corrosion measurement technique. Finally, in the last verification study, the model’s interpretation of the effects of concrete resistivity and the oxygen concentration on the corrosion rate is verified. In all cases, it has been demonstrated that the developed model predicts the experimental observations with reasonable accuracy.     

电机传动机构动力学建模、仿真与实验验证

摘要：建立正确的电机动力学模型是分析系统稳定性和动态特性的基础。考虑到用电设备工作时的脉冲电流是发电机传动机构扭转振动的主要激励源,利用集中参数法建立了某型交流发电机的动力学模型,并在MATLAB环境下对其进行动态仿真分析,得到脉冲电流作用下弹性轴冲击扭转振动的力矩曲线与扭转角曲线。通过对仿真结果的对比分析,发现适当增大弹性轴的轴径,可以有效缓解弹性轴扭转力矩的振动峰值,并提高系统的频率裕度。最后,通过动态测试实验,验证了电机动力学模型与仿真结果的有效性。     

Optimum design of a cogeneration system in processes

Abstract

A systematic method is presented for the preliminary design of a cogeneration system with the desire of achieving minimum operating costs. The ratio of power to process heat is shown to be a critical factor in the preliminary selection of energy conversion systems. However, the final decision should be based on the operating costs and economical index, ROI. A fuel substitution factor is proposed to define theoretically the most economical power generation in plants. Two case studies are demonstrated to describe this approach.     

Sensitivity analysis for reliable design verification of nuclear turbosets

In this paper, we present an application of sensitivity analysis for design verification of nuclear turbosets. Before the acquisition of a turbogenerator, energy power operators perform independent design assessment in order to assure safe operating conditions of the new machine in its environment. Variables of interest are related to the vibration behaviour of the machine: its eigenfrequencies and dynamic sensitivity to unbalance. In the framework of design verification, epistemic uncertainties are preponderant. This lack of knowledge is due to inexistent or imprecise information about the design as well as to interaction of the rotating machinery with supporting and sub-structures. Sensitivity analysis enables the analyst to rank sources of uncertainty with respect to their importance and, possibly, to screen out insignificant sources of uncertainty. Further studies, if necessary, can then focus on predominant parameters. In particular, the constructor can be asked for detailed information only about the most significant parameters.     

结构参数对机翼非线性颤振系统混沌运动特性的影响

机翼非线性颤振系统中的混沌运动是一种复杂的非线性动力学现象,研究结构参数对机翼非线性颤振系统混沌运动特性的影响,对非线性动力学系统的混沌运动控制具有重要意义。建立具有立方型非线性操纵刚度的带操纵面二元机翼的颤振方程,采用数值积分方法分别获得该非线性颤振系统在不同阻尼水平和不同操纵刚度下的分岔特性图。对分岔特性图进行对比分析结果表明：操纵面的操纵刚度并不影响系统的混沌运动特性,而操纵面偏转自由度或机翼俯仰自由度上的阻尼将会影响系统混沌颤振区域内的周期窗口,进而影响系统的混沌运动特性,特别是两自由度中任意一个的阻尼水平减小到一定程度时,系统混沌颤振区域内的周期窗口都将会消失;但是,单一的减小某个自由度上的阻尼水平,会使机翼非线性颤振系统的颤振临界速度降低。为了使得该系统在混沌颤振区域内不产生周期窗口又不降低其颤振临界速度,可采用在减小俯仰自由度阻尼的同时增大操纵面偏转自由度阻尼的方法。     

Novel collaborative optimization framework with a negotiation model for satellite system design

This article proposes a novel collaborative optimization (NCO) framework that uses a persuasive multi-agent negotiation method for satellite system design. Satellite system design is a typical multi-disciplinary design optimization problem. The traditional collaborative optimization (CO) is a competitive method but has the disadvantage of inefficient convergence caused by the interdisciplinary compatibility constraints in system-level optimization. By introducing the multi-agent negotiation method, an NCO framework is proposed, in which the system-level and subsystem-level variable negotiations replace the system-level compatibility constraints in traditional CO. The negotiation introduces a modification for candidate values that do not satisfy the compatibility constraints, ensures that an alternative compatible candidate will be obtained and has high convergence efficiency. Two numerical benchmark functions and a multi-disciplinary satellite system design are used to analyse the performance of the proposed NCO. The simulation results show that NCO can efficiently ensure parameter interdisciplinary matching and advanced convergence performance.     

基于处理器硅前性能验证平台的基准程序库设计方法

提出了一种新的适用于处理器的硅前性能验证平台的基准程序实现方法.方法的主要思想是利用现成的广泛使用的测试程序集合,通过降低工作负载,采用基于基本块的划分、归并方式,将多个基于相同特征点的代码片段作为一个基准检测点,这些抽象的检测点构成了基准程序库.该方法将复杂的处理器内部行为的一致性判断转换为性能的宏观统计分析,充分利用了已有的权威测试基准集,无需重新编写性能验证平台的基准程序,既扩大了验证程序的规模,又节省了大量的劳动,同时可以针对验证样本通过分析系统自动展开验证工作,减少了人工核对的工作量.     

二维正交柱透镜列阵光学系统及优化设计

提出二维正交凸柱透镜列阵光学系统,可实现靶面光强二维均匀辐照,应用矩阵光学和衍射积分理论,详细分析了工作原理、焦斑强度分布特性,并从衍射、干涉等角度分析了系统参数与强度分布的关系,给出了详细的系统优化设计参数和数值计算结果。