基于Witness的配送中心系统仿真设计

介绍了配送中心系统仿真的现状以及Witness的基本应用,说明了物流配送过程和计算机仿真的关系,讨论了在物流配送中利用Witness软件进行仿真的方法,并通过设置参数达到实现物流配送优化的目的.     

基于WITNESS的制造系统优化

分析了如何利用Witness仿真软件进行制造系统的仿真问题,在此基础上研究了制造系统的优化策略,为提高制造系统的效率提供了较为准确的量化依据.这对今后利用Witness软件进行其他类似的仿真优化工作,具有很好的借鉴意义.     

基于Witness的生产物流系统仿真与优化

介绍物流系统仿真的概念以及Witness的基本应用,并针对生产过程分析的困难,说明了生产过程和计算机仿真的关系,以半轴总成装配线为例,讨论了在生产过程中利用Witness软件进行仿真的方法,并通过设置参数达到实现实际生产过程优化的目的。     

基于Witness的发动机缸盖分装线仿真研究

以S汽车公司发动机项目中的缸盖分装线为研究对象,采用Witness仿真软件对该生产线的制造流程进行仿真建模,研究评估产线能力是否能够满足产能要求,并运用灵敏度分析的方法,解决了生产线在线托盘数量最优的问题。同时,也进一步证明Witness仿真软件在动力总成生产线设计规划过程中起到的关键作用。     

基于Witness的供应链多产品库存系统仿真研究

运用Witness仿真软件模拟供应链多产品库存控制模型,在仿真实现的手法上进行一定的创新,借助于统计变量、统计函数、逻辑判断函数等实现供应链多产品库存系统,最后结合供应链库存系统的效益评价指标,运用Witness仿真软件中的优化模块,得到决策数据报表,根据决策者的决策重点的不同,寻求最佳库存策略组合。     

基于Witness的供应链多产品库存系统仿真研究

运用Witness仿真软件模拟供应链多产品库存控制模型,在仿真实现的手法上进行一定的创新,借助于统计变量、统计函数、逻辑判断函数等实现供应链多产品库存系统,最后结合供应链库存系统的效益评价指标,运用Witness仿真软件中的优化模块,得到决策数据报表,根据决策者的决策重点的不同,寻求最佳库存策略组合.     

基于Witness的凸轮轴生产线生产节拍的仿真与优化

以某公司生产的汽车发动机进气凸轮轴为研究对象,利用Witness仿真软件对其生产物流系统仿真分析并进行优化,确定生产节拍,进而提高生产效率。优化结果表明,在制品数量由6137根减少到16根,产能能够达到生产纲领的要求,设备平均利用率稍有下降,但闲置设备还可用于其他产品的加工。通过仿真,可有效缩短生产线的设计周期,降低资金投入,提高生产效率,增强核心竞争力。同时,也进一步证明Witness仿真软件在生产线设计过程中起到关键作用,是物流设计的重要组成部分。     

基于Witness的制造瓶颈优化

利用Witness仿真软件进行制造系统的建模与仿真,分析制造系统的瓶颈环节,提出制造瓶颈的优化方案,改进制造系统,提高设备利用率,增加产量,充分发挥制造系统的生产能力。     

求解物流配送路径优化问题的一种改进蚁群算法

物流配送路径优化是现代物流配送服务的关键环节之一，由于需求的小批量和动态变化等特点，需要设计一个快速有效的求解算法。为此，构建了物流配送路径优化问题的数学模型，设计了一个改进的蚁群算法来求解该问题，引进了选择算子、插点操作和动态改变算法参数等改进措施，开发和实现了一个试验软件包。仿真试验结果表明，该算法具有较好的全局寻优能力，收敛速度快，是解决物流配送路径优化问题的有效算法。     

基于Witness车辆路径问题的仿真建模与优化

简要介绍了车辆路径问题及仿真的知识,针对实际问题,利用Witness仿真软件,建立车辆路径问题的仿真模型,然后运行仿真模型,得到仿真输出结果,通过对模型结果的输出分析,寻找车辆路径问题的瓶颈因素,通过对瓶颈因素的解决,进行问题的优化,最后得到更优的可行解。     

Minimal Realization of Linear Graph Models for Multi-physics Systems

An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t...     

On the Relation of Load to Average Gap in the Contact Between Surfaces with Longitudinal Roughness

A computer simulation model for the contact between longitudinally-oriented rough surfaces has been formulated. This model closely duplicates the actual surf ace contact deformation behavior by taking into account the elastic interactions between the asperities. There were no assumptions made about the shapes, or any deformation behavior of the asperities, except for their obeying the laws of elasticity. The plastic deformations on the high asperity peaks were taken into account by setting a ceiling on their contact pressures at the material hardness value. The simulations used real surface profiles which were digitized from unworn circumferentially ground steel surfaces. Each pair of these profiles was mathematically combined to form an equivalent rough profile pressing against an infinitely rigid flat and having the appropriately adjusted elastic modulus. A total of 28 different pairs of profiles were used in the simulations. Each contacting pair was subjected to 30 different load levels and the local contact pressures and deformations were calculated. The contact simulations yielded some important mathematical relationships between parameters, such as the real area of contact, average gap, and average asperity load through statistical curve fitting. Two analytical functions were generated to relate the average load to average gap and the real area of contact to load.     

三绕组变压器的双绕组等效建模及在Matpower中的应用

针对实际电网存在着大量的三绕组变压器,但国际上一些著名商业软件,如BPA仿真软件、Matpower这一权威潮流计算开源软件,均只提供双绕组变压器模型,限制了其在具有三绕组变压器的电力系统中的应用的问题,潮流计算是自主开发的电力系统各种应用软件的核心模块,因此依托国际权威开源程序进行二次开发,是一种较好的选择。对Matpower要求的数据格式进行了归纳,对变压器的一般的等值电路及带理想变压器的等值电路和带标幺值的等值电路进行了分析研究,提出了三绕组变压器转换为双绕组等效模型的建模方法,使得原先只适应双绕组变压器的潮流计算软件可以适用于三绕组变压器电网的潮流计算;最后以Matpower软件为例进行了案例计算,并用PSASP仿真软件进行对比验证。研究结果证明,所提出的建模方法是有效的。     

Quantum Cooperative Robotics and Autonomy

The intersection of Quantum Technologies and Robotics Autonomy is explored in the present paper.The two areas are brought together in establishing an interdisci...     

电站锅炉模糊风险评价方法研究与应用

针对电站锅炉风险等级评价问题,将模糊综合评价技术应用到电站锅炉风险等级评价中。开展了电站锅炉失效影响因素及模糊评价因素的重要程度分析,建立了一套科学合理适于在线评价的电站锅炉风险评价体系,提出了模糊综合评价技术与改进的模糊层次分析法相结合的模糊风险评价方法,利用改进的模糊层次分析法计算了指标体系中各层指标权重。对某一台电站锅炉的实际运行工况影响子因素进行了模糊风险评价,采用模糊合成算子进行模糊综合运算得到电了站锅炉运行工况影响子因素的评价向量。研究结果表明:电站锅炉的运行工况影响子因素的风险评价等级为第6级,失效可能性等级为小,该电站锅炉运行工况良好。     

考虑进油孔有限长滑动轴承油膜力的近似解析解

针对具有进油孔的有限长滑动轴承油膜力求解问题,采用变分原理和分离变量法,求得了有限长滑动轴承油膜压力分布的近似解析表达式。将油膜压力分布的近似解析表达式在油膜存在区域上进行积分,即得到了油膜力。将提出的计算有限长滑动轴承油膜力方法与无限长轴承模型、有限元方法的计算结果进行了比较,发现了提出的方法与有限元方法的计算结果很接近。最后,研究了进油孔位置和进油压力对油膜存在区域、油膜力等的影响,研究结果表明进油孔位置和进油压力对油膜存在区域和油膜力有较大的影响。     

Fifth International Summer School on Screw-Theory Based Methods in Robotics

正3-11 September,2014University of Bologna,Bologna,Italy www.summerscrews.org summerscrews2014.ing.unibo.it SUMMER 20SCREWS 14In 2014,our screw-theory school comes to the world's oldest university.In early September,Summer Screws'14 will gather six experts in the application of screw theory in robotics and up to 40 participants at the University of Bologna,Bologna,Italy.The school will teach attendees how to apply existing methods and empower them to develop new ones in their own research.The basic theoretical notions will be introduced in a rigorous manner,emphasizing examples,applications,and exercises.Scholarships are available.     

交通荷载作用下桥梁结构参数识别方法

应用动力节点加载法,将作用在桥梁上的交通荷载转化为等效节点荷载,再用两步构造法识别结构物理参数.第1步,用Newmark-β方法变换结构运动方程,并用结构的加速度响应求得变换空间内的位移、速度和加速度响应;第2步,基于最小二乘原理,构造出变换空间内求解结构参数的递推式,进行结构物理参数识别.数值模拟结果表明,在交通荷载作用下,该方法能够快速、准确地进行桥梁结构参数识别.     

INDUSTRIAL ENGINEERING AND VISUALISATION-A PRODUCT DEVELOPMENT PERSPECTIVE

Taking the actual project of teaching and researching process for example, the relationship between the industrial engineering and product development is discussed. And use the novel visualization technology to support the industrial engineering and product development. How to use the new computer modeling and simulating technologies to support the product development and industrial engineering, is introduced especially. The support includes both domestic products and industrial systems. The visualization and computer technologies take a very important role in some system or multi-direction modeling, those technologies mentioned above can help the industrial engineers study the effect of design on the whole life circle, including the producing steps. So the engineers can avoid making the wrong decision which may cause bad effects on the whole industrial engineering.     

Non-monotonic material contrast in scanning ion and scanning electron images

30 keV Ga⁺ focused ion beam induced secondary electron (iSE) imaging was used to determine the relative contrast between several materials. The iSE signal compared from C, Si, Al, Ti, Cr, Ni, Cu, Mo, Ag, and W metal layers does not decrease with an increase in target atomic number Z₂, and shows a non-monotonic relationship between contrast and Z₂. The non-monotonic relationship is attributed to periodic fluctuations of the stopping power and sputter yield inherent to the ion–solid interactions. In addition, material contrast from electron-induced secondary electron (eSE) and backscattered electron (BSE) images using scanning electron microscopy (SEM) also shows non-monotonic contrast as a function of Z₂, following the periodic behavior of the stopping power for electron–solid interactions. A comparison of the iSE and eSE results shows similar relative contrast between the metal layers, and not complementary contrast as conventionally understood. These similarities in the contrast behavior can be attributed to similarities in the periodic and non-monotonic function defined by incident particle–solid interaction theory.