A systematic modelling and simulation approach for JIT performance optimisation

Robust computer aided simulation and modelling tools help to visualise, analyse and optimise complex production processes with a reasonable amount of time and investment. A review of the literature shows that simulation and modelling have not been extensively applied in just-in-time (JIT) manufacturing environments. Also there remains a lack of a comprehensive mechanism to identify the most significant JIT drivers for the purpose of system process optimisation. The prime objective of this study is to close this gap by applying computer based simulation tools and linear mathematical modelling to identify the impact of selected key JIT parameters on performance in an automotive component-manufacturing environment. Research shows that variables such as inconsistent task distribution, variation on operator performance, misconception of total quality management philosophy and lack of set-up time elimination plans disrupt ideal JIT production. In this study, ProModel simulation and modelling software is used to model and simulate different experimental scenarios in order to understand and quantify the impact of selected input key JIT variables on objective functions (i.e. process time and takt time). The outcome is a robust mathematical model that highlights the significance of JIT drivers in the manually operated mixed-model assembly lines.     

大型火电机组实时仿真机上的发电机数学模型

该文根据３３０ＭＷ火电机组培训实时仿真的要求，建立了发电机动态数学模型，描述了发电机的全部物理过程，建模过程作了合理的简化和假设，使仿真模型适用于机组的起动、正常运行及故障等各种工况。     

现代计算机仿真技术的研究与发展

讨论了基于模型活动的仿真概念，现代仿真方法学所涉及的系统建模方法，仿真建模方法和仿真实验，仿真建模中的常用算法和有关问题，仿真可信度概念及其研究内容，文章最后探讨了现代仿真技术的研究热点：面向对象仿真、定性仿真，智能仿真，分布交互仿真，可视化仿真，多媒体仿真，虚拟现实仿真等。     

车辆碰撞检测的一种简化数学模型

该文建立了车辆碰撞检测的一种简化数学模型,并进行了仿真验证。实际应用结果表明本模型具有简单和计算快捷的特点,能满足车辆碰撞检测的仿真要求。     

410t／h Pyroflow CFB锅炉仿真系统开发

该文介绍了基于Ｗｉｎｄｏｗｓ９５环境下的４１０ｔ／ｈ Ｐｙｒｏｆｌｏｗ循环流化床锅炉的仿真系统的设计与实现方法。仿真系统包括ＣＦＢ锅炉系统动态数学模型、仿ＤＣＳ系统的运行工程师操作界面、仿真输入输出数据的设计及处理等内容。本系统可用于现场运行工程师了解和掌握ＣＦＢ锅炉的动、静态特性、分析运行方式及运行工况变化对系统的影响以及进行事故预测及事故分析等工作。     

MATLAB在化工模拟计算中的应用

通过MATLAB辅助绿色含硫气湿法直接脱硫制酸新工艺及SO2转化器的模拟计算实例,着重介绍和说明了MATLAB在化工模拟数值计算及最优化、数值过程及结果的可视化、用户图形界面设计等方面的功能与应用。化学工作者利用MATLAB语言,即使不善精通数值计算方法和其它高级编程语言,也完全可以设计出功能强大,界面优美,稳定可靠的高质量化工模拟程序,并且可实现模拟计算结果的可视化和用户图形界面的一体化。     

直流调速系统的优化与仿真

提出了一种采用计算机仿真进行直流调速系统的优化与仿真的方法：首先,根据直流调速数字控制系统的性能特点,建立了系统仿真模型,然后分析了该系统的缺点所在并进行优化,从而构成一种复合控制系统,以实现对驱动电流的控制作用,最后对优化前后的输出数据进行分析对比,结果表明,采用优化后的控制系统可使输出数据更加精确可靠。     

室温变化的数学模型及其仿真

该文介绍了一种用差分方程建立的室温变化的数学模型，并用此模型对不同条件和参数的情况的室温变化进行了模拟和仿真。其结果表明，此模型有助于热力系统的试验和设计，是十分实用的。     

Collaborative distributed environments for learning design tasks by means of modelling and simulation

The Simulation discipline has to face new challenges such as the incorporation of Collaborative Technologies for professional use as well as for teaching purposes. This integration permits the creation of new kinds of support for collaborative learning processes. In this paper, we explore the potential of this synergy with DomoSim-TPC, a synchronous distributed collaborative environment for the teaching and learning of Domotics. The system supports an active, simulation-based and problem-based approach for learning house automation design. Using this learning environment, teachers propose and organize problem solving activities and the students carry out, in a collaborative way, the construction of artefacts (designs) using modelling and simulation tools.     

燃油热水锅炉水循环动态数学模型及仿真

该文介绍“锅炉仿真培训系统”中采暖燃油热水锅炉水循环动态数学模型及仿真策略，提出了补水泵、循环泵和压力节点的基本方程，给出了模型参数估算方法和模型求解策略，举例说明了热水锅炉采暖外网持水量估算方法，最后介绍了该模型的特点和实际应用情况。     

中国水墨画的基本艺术特征及其计算机仿真实现

为了实现中国水墨画的计算机仿真 ,通过对中国水墨画艺术效果中 ,笔、水、墨、纸的特性及相互影响制约因素的分析 ,将中国水墨画绘画过程“量化”、“标准化”,使得这一过程具有可控性和可预见性 .通过抽取体现水墨画特征的典型艺术效果 ,对中国水墨画中诸如 :笔法、纸张等进行大胆的归类 ,让其减少到可控的少数几种之内 ,并对感性的艺术效果进行了数字化定义 .在上述分析的基础上 ,建立了一个专门用于模仿水墨画效果的三维纸纤维模型 ,并在此基础上实现了对单笔水墨画效果的计算机仿真 .最后还将纸纹理的干扰作用考虑进去 ,从而使得仿真效果更加多样、更加真实 .     

An adaptive system for modelling and simulation of electrical arc furnaces

Modelling and simulator development for electric arc furnaces (EAFs) are of significant importance in designing control systems and in performance optimisation of EAFs. This paper presents a method based on adaptive neuro-fuzzy inference systems (ANFIS) for modelling and simulating EAFs with the focus on the regulator loop that is used for positioning the electrodes. The effectiveness of the simulator is shown through experiments by comparing the simulator outputs with actual plant data, using the EAF of Gerdau Ameristeel Whitby (GAW) in Ontario, Canada.     

基于Excel的设备投资仿真分析

电子表格Excel具有强大的计算功能,它提供了一种描述问题、建立模型、处理数据与求解的有效工具。通过汽车维修设备投资中的一个实例,说明它在计算机仿真决策中的应用。     

A feasible timetable generator simulation modelling framework for train scheduling problem

An important problem in management of railway systems is the train scheduling/timetabling problem. This is the problem of determining a timetable for a set of trains that do not violate track capacities and satisfy some operational constraints. In this study, a feasible timetable generator framework for stochastic simulation modelling is developed. The objective is to obtain a feasible train timetable for all trains in the system. The feasible train timetable includes train arrival and departure times at all visited stations and calculated average train travel time. Although this study focuses on train scheduling/timetabling problem, the developed simulation framework can also be used for train rescheduling/dispatching problem if this framework can be fed by real time data. The developed simulation model includes stochastic events, and can easily cope with the disturbances that occur in the railway system.     

水面舰艇综合导航系统数学处理模型设计和仿真试验研究

按照现代控制论的设计观念,从工程实际出发,提出了三种综合模式的数学模型,进上步采用先进的仿真技术,在宿主工作站上的ＭＡＴＲＸｘ开发环境下对所建立的数学模型进行仿真试验研究,仿真结果表明,系统的数据处理模型设计具有可控性、稳定性和良好的收敛性、稳定性、滤波效果良好,可直接应用到系统的工程研制中。     

人体生理系统计算机仿真

人体生理系统是一个复杂的非线性动态系统，本文根据人体生理系统的数学模型Ｈｕｍａｎ，介绍了基于这种数学模型的仿真方法，并在微机上实现了计算机仿真系统ＨＰＳＳ，在文章的最后给出了若干仿真实验的结果。     

CHEOPS: A tool-integration platform for chemical process modelling and simulation

A large number of modelling tools exist for the construction and solution of mathematical models of chemical processes. Each (chemical) process modelling tool provides its own model representation and model definition functions as well as its own solution algorithms, which are used for performing computer-aided studies for the process under consideration. However, in order to support reusability of existing models and to allow for the combined use of different modelling tools for the study of complex processes, model integration is needed. This paper presents a concept for an integration platform that allows for the integration of modelling tools, combining their models to build up a process model and performing computer-aided studies based on this integrated process model. In order to illustrate the concept without getting into complicated algorithmic issues, we focus on steady-state simulation using models comprising only algebraic equations. The concept is realized in the component-based integration platform CHEOPS, which focuses on integrating and solving existing models rather than providing its own modelling capabilities.     

Characterization of server performance bottlenecks in distributed interactive simulation environments

Servers running distributed simulation applications need to process a large number of small packets at the network level. This becomes a burden on the server CPUs and exhibits itself as high CPU utilization. In this paper, first, we confirm this phenomenon, then, we utilize performance analyzer tools from major processor vendors to characterize the major sources of CPU usage. In addition, the experiments run on real hardware reveal server bottlenecks within the context of new architectural features such as hyper-threading, hyper-transport and multi-core processors.     

基于特性方程的离心压气机的性能仿真

详细分析了空气在离心压气机中的流动机理,基于特性方程建立了一种能够达到设计精度要求的快速简单的离心压气机数学模型,模型中计及离心压气机内出现的各种损失。性能仿真模型具有速度快,适用于大量计算等优点。用Modelica语言和Dymola编译器实现了离心压气机的性能仿真。采用建立的数学模型对Chevis离心压气机的性能进行了模拟,并把仿真结果同实际性能曲线进行了比较。结果表明,采用建立的性能仿真数学模型能够模拟离心压气机性能,并能够实现非设计转速小流量工况下的性能仿真,为设计离心压气机提供了一个有力的工具,具有重要的参考价值。