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.     

Uanova: a fortran IV program for unbalanced nested analysis of variance

A FORTRAN IV program (UANOVA) to carry out unbalanced analyses of variance, associated variance component testing using synthesized error mean squares and degrees of freedom where appropriate, and the generation of summary statistics is presented. Data transforms are available to assist in meeting the requirements of the ANOVA method, and the data structure is defined as part of the input stream. The summary statistics include estimates of the population mean and variance, and confidence limits for the mean and variance components. The latter are approximations for levels higher than the first, however their calculation affords on indication of the imprecision of the point estimates. The program has been verified, where possible, with published data sets, results of these tests are presented.     

Automatic eye fixations identification based on analysis of variance and covariance

Eye movement is the simplest and repetitive movement that enables humans to interact with the environment. The common daily activities, such as reading a book or watching television, involve this natural activity, which consists of rapidly shifting our gaze from one region to another. In clinical application, the identification of the main components of eye movement during visual exploration, such as fixations and saccades, is the objective of the analysis of eye movements: however, in patients affected by motor control disorder the identification of fixation is not banal. This work presents a new fixation identification algorithm based on the analysis of variance and covariance: the main idea was to use bivariate statistical analysis to compare variance over x and y to identify fixation. We describe the new algorithm, and we compare it with the common fixations algorithm based on dispersion. To demonstrate the performance of our approach, we tested the algorithm in a group of healthy subjects and patients affected by motor control disorder.     

方差分析数据处理系统的设计

利用Visual Basic设计了方差分析数据处理系统。简单介绍了方差分析的概念及作用,详细介绍了方差分析数据处理系统的设计,并对所设计的数据处理系统进行了性能评价。用方差分析数据处理系统考察影响油页岩渣浸出过程,发现B(碱液浓度)(F=73.1616)和C(油页岩渣粒径)(F=82.0762)是影响浸出过程的主要影响因素。表明本系统能在化学工业生产领域发挥良好的作用。     

Regressor selection with the analysis of variance method

Identification of non-linear dynamical models of a black box nature involves both structure decisions, i.e., which regressors to use, the selection of a regressor function, and the estimation of the parameters involved. The typical approach in system identification seems to be to mix all these steps, which for example means that the selection of regressors is based on the fits that is achieved for different choices. Alternatively one could then interpret the regressor selection as based on hypothesis tests (F-tests) at a certain confidence level that depends on the data. It would in many cases be desirable to decide which regressors to use independently of the other steps.In this paper we investigate what the well-known method of analysis of variance (ANOVA) can offer for this problem. System identification applications violate many of the ideal conditions for which ANOVA was designed and we study how the method performs under such non-ideal conditions.ANOVA is much faster than a typical parametric estimation method, using e.g. neural networks. It is actually also more reliable, in our tests, in picking the correct structure even under non-ideal conditions. One reason for this may be that ANOVA requires the data set to be balanced, that is, all parts of the regressor space are weighted equally. Just applying tests of fit for the recorded data may give, for structure identification, improper weight to areas with many, or few, samples.     

聚合反应装置计算机仿真控制系统设计

本文介绍聚丙烯反应釜生产过程仿真培训系统，从工艺流程、人工控制、自动控制等对聚丙烯生产过程进行全面仿真，采用面向对象设计。多用户交互方式网络环境下运行，经过实验培训得到较好效果。     

Statistical analysis for the manufacturing of multi-strip patterns by roll-to-roll single slot-die systems

Roll-to-roll (R2R) slot-die coating systems are mostly devoted to the mass manufacture of printed electronics. This study examined the correlation among the operating conditions, thickness, and width of the patterned strip fabricated by the R2R slot-die system. A full factorial experiment was conducted to screen for effective parameters. The velocity of a moving substrate was found to be the most dominant parameter affecting the thickness and width of the patterned strips. The flow ratio of the supply to the slot-die, and gap between substrate and slot-die did not affect the width of the strip, but affected the thickness; therefore, the flow ratio and gap can be employed for the independent patterning of thickness against width. In addition, it was proposed to determine the R2R process conditions, such as gap, velocity, and flow ratio for the desired thickness and width of the patterned strips.     

Estimating the number of groups and group membership using simulation cluster analysis

A procedure to incorporate measurement error into a cluster analysis through the use of computer simulations is developed. The simulation cluster analysis (SCA) procedure is a method of summarizing the results of the computer simulations in order to estimate the number of groups and the group membership. The SCA procedure requires specification of the measurement error distribution, but initial Monte Carlo studies indicate that precise specification is not necessary. Also, Monte Carlo studies indicate that the SCA procedure performs well in comparison to alternative methods. Two example data sets are analyzed.     

Estimating variance components with BMDP for analyses of technical reliability

Measurement reliability reflects the ratio of true (subject) to observed (subject plus error) variance. Analyses of reliability are limited due to difficulties in obtaining accurate estimates of the sources of variation upon which this relationship depends. This paper presents a simple analysis of variance procedure, using BMDP8V, for estimating the necessary variance components of mixed models, from which reliability may be assessed.     

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。     

Investigation of port capacity under a new approach by computer simulation

This paper investigates the role of computer simulation in evaluating the performance of a container terminal in relation to its handling techniques and their impact on the capacity of terminal. The paper investigates and compares two different operational systems (current and proposed) statistically via a simulation model. The paper also addresses issues such as the performance criteria and the model parameters to propose an operational method that reduces port terminal congestion and increases the capacity of terminal.     

一种有限元侵彻仿真模型的参数优选方法

在侵彻问题的有限元仿真中,为了提高仿真精度,将仿真试验误差分解、控制在有限元分析的各个阶段,引入了正交试验设计理论,对侵彻试验方案进行了组配、评估及优化,确定了仿真算例的最佳参数设置.采用方差分析的方法,研究了网格划分、接触算法的选择对仿真试验结果总变差的影响程度.研究结果表明:在显著性水平α=0.1下,单元尺寸、单元形状对仿真精度的影响呈高度显著,是影响仿真精度的主要因素;而两种二维接触算法在本算例中是影响仿真精度的次要因素,对仿真精度的影响差别不大.     

A mathematical model for transient analysis of computer systems

The study of computer system dynamic behavior is a prerequisite for the design and implementation of automatic mechanisms for performance control. An analytic technique for modelling the transient behavior of computer systems is presented and a suitable method for modelling job dynamics is given.

The system model is discussed from the viewpoint of transient analysis with particular reference to bottleneck identification and to bottleneck migration analysis.

A mathematical study is given together with a numerical algorithm. The model is validated on the basis of suitable experimental results.     

Analysis of variance of Gabor filter banks parameters for optimal face recognition

Gabor filter banks constitute a very robust tool to extract discriminant information from a visual scene. After the now “classical” bank with 5 frequencies and 8 orientations proposed by Lades et al. and Wiskott et al., many other parametrizations of a Gabor filter bank have appeared. In order to find the optimal parametrization for a face recognition experiment, we have performed a 6-way analysis of variance of Gabor parameters using FERET, FRAV2D, FRAV3D, FRGC and XM2VTS face databases, including frontal and turned poses, facial expressions, occlusions and changes of illumination. Considering independent criteria to find the optimal Gabor filter bank, the bank with the highest recognition rate was found to have 6 frequencies and narrower Gaussian widths in the space domain. These results were obtained with Mahalanobis distance for a k-NN classifier, with analytical and holistic Gabor feature vectors. Moreover about 20% of the banks studied here obtained in average a better performance than the classical bank. For most of the databases considered, the highest recognition rates have been achieved with analytical representations (frontal images, images with turns or occlusions), with a holistic preponderance for images with gestures or changes of illumination. The inferiority found for holistic Gabor representations versus their analytical counterparts can be explained for the intrinsic redundancy and the size of the feature vectors of this kind of representation.     

Automatic analysis and integration of architectural drawings

Recognition and integration of 2D architectural drawings provide a sound basis for automatically evaluating building designs, simulating safety, estimating construction cost or planning construction sequences. To accomplish these targets, difficulties come from (1) an architectural project is usually composed of a series of related drawings, (2) 3D information of structural objects may be expressed in 2D drawings, annotations, tables, or the composites of above expressions, and (3) a large number of disturbing graphical primitives in architectural drawings complicate the recognition processes. In this paper, we propose new methods to recognize typical structural objects and architectural symbols. Then the recognized results on the same floor and drawings of different floors will be integrated automatically for accurate 3D reconstruction.     

Synergies of simulation, agents, and systems engineering

Simulation, software agents, and systems engineering are three important disciplines; each of which support many application areas. In this article it is pointed out that their usefulness and efficacy can be significantly improved by first and higher order synergies.     

空地微型导弹导引与控制一体化设计与仿真

以某空地微型导弹为研究对象,研究了导引控制一体化控制器设计问题.为了实现导弹导引控制一体化,建立了俯仰、偏航通道的一体化模型,并将其转化为具有一般形式的含未知有界不确定性的子系统.采用自适应滑模控制方法设计了非线性一体化控制律.通过导弹空对地攻击的六自由度非线性数字仿真验证了导弹导引控制一体化控制算法的可行性、有效性.所设计的控制器一方面能保证导弹自身姿态的稳定性,另一方面具有较高的制导精度.对微型导弹的研制具有一定的参考意义.     

The design and calibration of a simulation model of a star computer network

A simulation model of the CERN (European Organization for Nuclear Research) SPS star computer network is described. The model concentrates on simulating the message handling computer, through which all messages in the network pass. The paper describes the main features of the model, the transfer time parameters in the model and how performance measurements were used to assist in the calibration of the model.