模糊综合评判法在企业信息化事前评价中的应用

企业信息化是一项复杂的工程,要确保信息化建设的成功,需要在建设前期就对企业实施信息化的能力进行评价.从企业绩效的角度出发,基于平衡计分卡思想制定了适合企业信息化事前评价的指标体系,利用模糊综合评判法对该企业进行整体评价.对事前评价结果进行了分析,找出了企业管理中存在的瓶颈,为其成功实施信息化提供了科学依据.     

AHP方法在印刷企业信息化综合评价中的应用

通过分析研究, 建立综合评价印刷企业信息化水平的综合评价的六大指标体系:战略地位、基础设施、应用状况、人力资源、信息安全和经济效益,用层次分析法构造印刷企业信息化水平的层次分析结构模型, 并以实例进行应用分析.     

基于模糊综合评判的MIE需求诊断方法

研究了制造业信息化工程需求分析的现状，提出并设计了基于模糊综合评判的制造业信息化工程需求诊断方法，实现了由定性分析向定量分析的转变，指出了该方法的研究重点在于建立需求评价指标体系和模糊关系矩阵，并围绕这一过程建立了最终判断制造企业信息化工程能力的逻辑关系模型。     

企业资源计划项目综合评价指标及应用实例

企业资源计划（ERP）是推进企业电子化管理的一个重要举措。近年来，我国企业实施ERP的热情很高，国内各种报刊杂志对为什么要实施ERP、如何实施ERP讨论得多；但是对ERP系统的实施评价问题研究比较少。文章把企业应用能力水平与应用效果联系起来建立一个ERP项目的综合评价指标体系，并以一家企业为案例背景，介绍了指标体系的应用情况，总结了该公司的经验，供其他企业参考。     

ERP绩效指标体系的建立及模糊评价

本文通过分析影响ERP绩效的三个主要因素(学习、流程和创新)，在结合ERP实施绩效所面临的内鄢约束和外部约束的基础上，提出了一个衡量ERP绩效的指标体系，并构建了一个适合对我国企业实施ERP绩效进行分析论证的模糊综合评判模型，为我国企业改善ERP实施效果提供了新的思路。     

标准质量与实施效果评价方法及应用研究

标准在提高产品质量、服务质量以及提升核心竞争力等方面发挥了越来越重要的作用。标准质量和应用实施的效益是影响标准作用发挥的重要因素。本文主要对标准质量与实施效果评价的内容与过程、社会效益和经济效益的指标体系进行了分析,提出了量化综合评价的指标体系,并对量化综合评价的方法和实施过程进行了初步探讨。     

面向过程的企业绿色制造环境绩效评价体系

为了实现绿色制造环境绩效评价对绿色制造实施过程的监督和检验作用,提出一种面向过程的绿色制造环境绩效评价体系,包括绩效指标体系和评价方法2个方面。从绿色制造实施流程出发,分析环境绩效评价内容,得到具有过程特征的绩效评价指标体系,包括3个阶段,即基础建设、应用实施和持续改进,并介绍了各阶段之间的相互影响关系。分析环境绩效指标值的确定方法,采用目标递进的层次分析法确定指标权重,应用过程评价方法得到绩效结果,以实现对绿色制造实施过程的动态评价。该评价体系在重庆某机床厂再制造工程中的初步应用验证了其有效性。     

ERP项目立项前的实施风险灰色多层次评价模型

针对ERP项目立项前的实施风险量化评价问题,结合实施企业内外两方面风险因素,运用层次分析原理,采用案例调查和专家意见征询方法,构建了ERP项目立项前的实施风险评价指标体系,将灰色系统理论与层次分析法相结合,建立了ERP实施风险灰色多层次评价模型,并应用于企业实例之中.     

ERP实施能力测度模型设计与研究

在分析我国企业管理现状和信息化水平的基础上,结合国内外研究成果,提出了ERR实施能力测度模型(ICEM)。该模型力图解决国内企业实施ERR过程中缺乏有效的能力诊断及评价方法的问题。主要就ICEM的测度指标体系及指数合成算法进行了论述。     

制造业信息化评价指标体系和方法研究

在分析中国制造业信息化水平评价现状的基础上,提出了制造业信息化评价指标体系。运用信度分析和效度分析确定正式评价指标体系和调查问卷。给出了制造业信息化指数的计算方法。最后对信息化指数进行了分析研究。     

锆金属粉尘云最小点火能和最低着火 温度的试验研究

为研究锆金属粉尘云燃烧的基础特性参数,从而为其安全性能提供依据,采用哈特曼管试验系统和最低着火温度测定系统分别对锆金属粉尘云的最小点火能（MIE）和最低着火温度（MIT）开展试验研究。分别研究了锆金属粉尘云质量浓度、点火延迟时间和喷粉压力对MIE的影响,以及粉尘云质量浓度对MIT的影响。结果得出:中位径为33.49 μm的锆金属粉尘云的MIE在1~3 mJ之间;在50~500 g/m³质量浓度范围下,随着质量浓度增大,MIE先减小后增大,在质量浓度为400 g/m³时达到最小;点火延迟时间从10 ms增至180 ms,MIE先减小后增大,在60 ms时达到最小;喷粉压力从0.4 MPa增至1.0 MPa,MIE先减小后增大,在0.6~0.8 MPa间达到最小。该粒度锆金属粉尘云的MIT为210 ℃左右,在一定浓度范围下,MIT随粉尘浓度的增加而减小。     

Igitability of sprayed liquids dut to an electrostatic spark

The minimum ignition energy (MIE) is a reasonable and practical index to assess the ignition risk of flammable materials. This paper reports the results of experiments dealing with the MIE due to an electrostatic spark of a sprayed liquid under various conditions. Four kinds of liquid (kerosene, n-decane, m-xylene and styrene) were used as the materials in this study. The liquid was pneumatically conveyed to the spray gun and automatically sprayed for 7 s to measure the MIE. The spatial distribution of the MIE in the spraying liquid under various conditions was also investigated in this study. The following results were obtained. (i) In the normal temperature range 0–30°C), all sprayed liquids can be ignited by the spark with a discharge energy below 10 mJ irrespective of their flash point. In particular, styrene was ignited at 4 mJ. (ii) An optimum region for ignition in a spraying liquid was observed, and it depended on the velocity, concentration and particle size of the liquid. Experimental details and a discussion are presented.     

制造物联网系统动力学建模与分析

动态因素影响生产系统的运作表现,而相应的流程再造和信息共享机制使得充满动态性的生产系统达到统计学意义上的运作最优化。随着系统动力学广泛应用于系统结构和参数的控制与仿真,物联网技术为广泛、实时、精确采集生产系统的动态性提供了使能手段,使得系统动力学可以在实时信息环境下对生产系统的运作表现进行全面、敏捷、精确的仿真和分析,使得制造物联网系统的运作达到最优。本文采用系统动力学构建仿真模型,对比分析物联网技术应用前后的生产系统运作差异,并通过投资回报率分析不同方案的经济可行性,为企业决策提供参考依据。     

制造企业运作绩效评价体系研究

在对制造企业运作绩效的内涵进行界定的基础上,介绍了运作绩效的主要构成因素.通过对其构成要素分析,进行了企业运作绩效评价体系的设计,并建立了制造企业运作绩效评价的指标体系.     

Influence of maintenance policies on multi-stage manufacturing systems in dynamic conditions

Manufacturing systems are subject to a degradation process that leads to machine failure if no action is taken. Machine failures reduce the performance of the manufacturing system with loss of profits. The research proposed here concerns the evaluation of the manufacturing system performance in dynamic conditions when different maintenance policies are implemented in a multi-machine manufacturing system controlled by multi-agent-architecture. There are two extreme maintenance policies that can be applied: no preventive maintenance, where action is taken on the failure state, and intensive preventive maintenance, which can eliminate unforeseen failures, but at a high cost. Dynamic policy maintenance is proposed to reduce the number of maintenance operations of the preventive policy. A discrete simulation environment has been developed in order to investigate the performance measures and the indexes of the costs of maintenance policies. The simulations have been conducted for several levels of mix, product demand and working time uncertainty. The simulation results show that the proposed approach leads to better performance for the manufacturing system and reduces the number of maintenance operations (cost index of the maintenance policy), except in the case of the mean time between failure, which is characterised by a very low standard deviation.     

分布式TMD对双密频结构的减振研究

针对密集频率结构的减振问题,以典型的2自由度对称结构为例,研究基于H2性能的梯度优化法对密集模态振动减振的分布式TMD(tuned mass dampers)的参数优化和减振效果。建立适合闭环静力反馈控制的组合系统模型,将基于H2性能的梯度优化法扩展至分布式TMD的参数优化;定义针对密集模态振动的控制输出和无量纲评价指标,分析了控制输出的模态控制权重对优化参数和评价指标的影响,指出能使评价指标峰值相等的模态控制最优权重,进一步给出优化参数和评价指标随模态密集度的变化规律;与经典方法对TMD的设计相对比,分析和验证了基于H2性能优化的分布式TMD的良好减振效果,并确认在TMD个数增多时基于H2性能的梯度优化法将具有更佳的优化效果。     

Multiple-image encryption scheme with a single-pixel detector

Abstract

A multiple-image encryption (MIE) scheme with a single-pixel detector has been proposed according to the principle of ghost imaging. In this scheme, each of the spatially coherent laser beams is modified by a set of phase-mask keys and illuminates on a secret image. All of the transmitted lights are recorded together by a single-pixel (bucket) detector to obtain a ciphertext, but anyone of the secret images can be decrypted from the ciphertext independently without any mutually overlapped despite some noise in them. The MIE scheme will bring convenience for data storage and transmission, especially in the case that different secret images need to be distributed to different authorized users, because the ciphertext is a real-valued function and this scheme can effectively avoid the secret images being extracted mutually. The basic principle of the MIE scheme is described theoretically and verified by computer simulations. Finally, the feasibility, robustness and encryption capacity are also tested numerically.     

A new method for guiding process flexibility investment: flexibility fit index

Flexibility enables manufacturing firms to respond efficiently to changes in the environment. Many firms make great efforts to increase their manufacturing flexibility to remain competitive in today's turbulent market. However, it is not true to say that the more flexible the better, because the cost of flexibility investment is high, and the capital for flexibility investment is limited. In this paper, we present a new method to guide process flexibility investment by developing a flexibility fit index. Taking demand changes into account, our method first defines a measure to quantify the requirement level of process flexibility. Then, a flexibility fit index is defined, which specifically identifies where flexibility is insufficient and where flexibility is surplus for a manufacturing system operating in a changing environment. The proposed fit index is objective and dimensionless, and so can be used more universally than previous subjective or non-dimensionless measures proposed in the literature. A set of simulation experiments shows that the proposed method can better guide flexibility investment by indicating the system structure which fits best with a given business situation, and other measures that ignore demand information may lead to over-investment or adding links that bring little benefit.     

Performance-based dynamic scheduling model for flexible manufacturing systems

A performance-based dynamic scheduling model for random flexible manufacturing systems (FMSs) is presented. The model is built on the mathematical background of supervisory control theory of discrete event systems. The dynamic FMS scheduling is based on the optimization of desired performance measures. A control theory-based system representation is coupled with a goal programming-based multi-criteria dynamic scheduling algorithm. An effectiveness function, representing a performance index, is formulated to enumerate the possible outputs of future schedules. Short-term job scheduling and dispatching decisions are made based on the values obtained by optimizing the effectiveness function. Preventive actions are taken to reduce the difference between actual and desired target values. To analyse the real-time performance of the proposed model, a software environment that included various Visual Basic Application® modules, simulation package Arena®, and Microsoft Access® database was developed. The experimentation was conducted (a) to determine the optimum look-ahead horizons for the proposed model and (b) to compare the model with conventional scheduling decision rules. The results showed that the proposed model outperformed well-known priority rules for most of the common performance measures.     

MIE散射系数的改进算法

提出一种新的计算MIE散射系数的算法。该算法使用了改进的后向递推公式,可对MIE系数中的消光系数Kext和散射系数Ksca进行精确计算。由于新算法能显著地减少计算循环次数,因此明显缩短了计算时间。对广泛运用的递推法和连分式法进行了比较详细的讨论。并且把新算法的计算结果和已有的成果进行了比较。结果表明:(1)计算的循环次数与粒子的复折射率基本没有关系;(2)连分式得到的结果通常最准确;(3)新算法在尺度系数较大时(>1000),计算时间仅为连分式算法的10-2~10-3,计算的误差小于10-5;(4)算法的适用范围广,对于尺度系数从10-6到106,复折射率从从10-6到106都能很好地进行计算。