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。     

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。     

基础IE及仿真技术在手机装配线优化中的应用

针对某手机装配线产品产能不达标的问题,提出了利用Witness仿真技术建立装配线的仿真模型进行优化研究的方案。首先,利用秒表测时法收集装配线各工位操作时间,并利用Minitab统计软件对收集到的数据进行拟合分析,获得最优拟合参数,同时对装配线建立仿真模型,找出瓶颈工位;然后利用Flexible Line Balancing软件、双手作业分析、防错法对瓶颈工位进行改善,从而减少了工时浪费,降低生产成本,提高产线生产效率。最后再利用Witness软件对优化方案进行检验,确保改善效果真实有效。     

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...     

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...     

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。     

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。     

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.     

INTEGRAL EQUATION METHOD＇S APPLICATION IN HOLE-EDGE STRESS OF COMPOSITE MATERIAL PLATE WITH DIFFERENT SHAPED HOLES

The strength of composite plate with different hole-shapes is always one of the most important but complicated issues in the application of the composite material. The holes will lead to mutations and discontinuity to the structure. So the hole-edge stress concentration is always a serious phenomenon. And the phenomenon makes the structure strength decrease very quickly to form dangerous weak points. Most partial damage begins from these weak points. According to the complex variable functions theory, the accurate boundary condition of composite plate with different hole-shapes is founded by conformal mapping method to settle the boundary condition problem of complex hole-shapes. Composite plate with commonly hole-shapes in engineering is studied by several complex variable stress fimction. The boundary integral equations are founded based on exact boundary conditions. Then the exact hole-edge stress analytic solution of composite plate with rectangle holes and wing manholes is resolved. Both of offset axis loadings and its influences on the stress concentration coefficient of the hole-edge are discussed. And comparisons of different loads along various offset axis on the hole-edge stress distribution of orthotropic plate with rectangle hole or wing manhole are made. It can be concluded that hole-edge with continuous variable curvatures might help to decrease the stress concentration coefficient; and smaller angle of outer load and fiber can decrease the stress peak value.     

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。     

Short-Term Relay Quality Prediction Algorithm Based on Long and Short-Term Memory

The fraction defective of semi-finished products is predicted to optimize the process of relay production lines, by which production quality and productivity ar...     

End-to-End Multiview Gesture Recognition for Autonomous Car Parking System

The use of hand gestures can be the most intuitive human-machine interaction medium.The early approaches for hand gesture recognition used device-based methods....     

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.