模糊资源约束的联合补充问题

针对不确定环境下的多产品联合补充问题,用三角模糊数表示不确定的资源约束,建立了模糊规划模型,目标函数为最小化订货成本和库存持有成本,决策变量为基本补充周期和每种产品的补充周期.用遗传算法对模型进行求解,以模糊规划模型的目标函数值作为染色体的适应度,阐述了染色体编码、选择、交叉、变异等遗传操作.最后,给出了仿真数值实例,比较了模糊资源约束模型和确定资源约束模型对1 600个随机生成问题的计算结果.     

不确定环境下跨国供应链生产计划研究

介绍了跨国供应链生产计划研究与不确定规划论在供应链计划研究中的应用;提出了包含模糊需求与随机生产能力的跨国供应链计划模型,模型中将运输成本分配因子与转让价格作为决策变量,根据随机机会约束规划等价类理论,将模型转化为模糊机会约束规划模型,并利用遗传算法与模糊模拟技术相结合的混合算法设计了模型的求解方案;最后,通过数据仿真说明了模型的有效性与适用性。     

电机企业面向供应链环境的集约生产计划优化研究

针对电机企业在不确定模糊条件下集约生产计划难以做出决策问题,建立了以最大化利润、最短生产用时、客户满意度最大化为目标的多目标集约生产计划模型。根据模糊区间理论将模糊模型清晰化,再运用层次分析法将多目标函数转化成单目标函数,通过精英保留策略的遗传算法对目标函数进行求解,结合案例证明该集约生产计划规划模型有效性。     

多品种汽车发动机两阶段模糊再制造生产计划

针对多品种发动机再制造生产过程中存在的不确定性因素,以最小化生产成本为目标,基于可信性理论建立了不确定环境下汽车发动机两阶段模糊再制造生产计划模型。该模型考虑多品种产品回收情况下,拆解零件的再制造加工数量、加工成本、新零件采购数量以及市场需求的不确定性对再制造加工生产计划的影响,将生产过程分为两个阶段,并采用补偿函数逼近方法,将具有无限支撑的无限维优化模型转化为有限维优化问题进行求解,设计了基于逼近方法的粒子群算法来求解两阶段模糊生产计划问题。以曲轴飞轮总成为仿真实例,验证了该混合智能优化算法解决两阶段模糊规划问题的有效性和合理性。     

模糊灰色智能优化算法在生产计划不确定规划中的应用

在模糊和灰色两类不确定因素并存条件下定义了模糊灰色变量,基于模糊灰色变量的可信性和机会测度建立了生产计划不确定规划模型.采用模糊灰色模拟技术对不确定目标函数和不确定约束产生输入输出数据,用产生的输人输出数据训练神经网络逼近不确定函数,通过基于遗传算法的混合智能优化算法得出最优解,并用实例说明了本模型和算法的有效性.     

面向半导体生产线生产计划的混合智能算法研究

针对传统半导体企业生产计划优化方法不能体现市场和生产环境中不确定性的不足,将模糊机会约束规划应用于半导体生产计划优化模型的建立,通过结合了模糊模拟和遗传算法的混合智能算法对半导体企业生产计划进行求解并通过实例及验证来说明该方法的可行性和有效性。     

模糊环境下基于可信性规划的生产计划方法

在客户需求、单位产品的价格、单位产品的生产成本和可用资源数量都是三角模糊变量的条件下,基于可信性规划建立了模糊生产计划模型。通过对模糊目标和约束的清晰化,将模糊生产计划模型转化为清晰等价形式,用非固定多段映射罚函数法将其转化为无约束两目标优化问题,并利用向量评价给出了求解此模型的改进粒子群算法。最后通过一个应用案例说明了所提方法的有效性。     

不确定环境下再制造加工车间生产调度优化方法

针对再制造加工车间工况兼具随机性与模糊性,采用模糊随机变量表示废旧件加工时间,以描述再制造加工车间工况的双重不确定性;在不确定理论的基础上,建立基于模糊随机机会约束的再制造加工车间生产调度问题模型,并提出求解该问题混合智能优化算法:基于Arena仿真平台应用模糊随机模拟技术产生输入和输出数据,利用粒子群优化算法训练径向基函数神经网络以逼近不确定函数,将训练好的神经网络嵌入至遗传算法中优化再制造加工车间生产调度问题;通过仿真实例验证该混合智能优化算法解决加工时间为模糊随机变量的不确定环境下再制造加工车间生产调度问题的有效性和合理性。     

不确定需求和能力约束下的多目标多工厂生产计划

针对多个具有供需关系的制造工厂和多个地域分散的客户组成的供需网络,研究了不确定需求、生产能力和运输能力条件下的多周期多目标生产计划方法,决策变量为每个周期上工厂的生产计划及工厂间的运输计划,优化目标为最大化总利润与最大化任意客户的平均客户满意度.利用模糊数描述不确定参数,在建立问题的混合整数规划模型后,将此模糊数学模型转化为最大化满意度的加权和模型,并提出了禁忌搜索与后向启发式方法相融合的B-TS算法.计算实例证明,B-TS算法能够有效获得多目标多工厂生产计划.     

柔性自动化车间的最优随机生产计划

研究了由多个柔性制造系统组成的柔性自动化车间的最优随机生产计划问题,首先根据实际需要建立车间生产计划的随机非线性规划模型,为求解方便,将其近似转化成确定非线性规划模型,并通过引进约束进一步转化成线性规划模型。由于这种模型规模较大,很难在微机上用单纯形法在可接受的时间内获得其最优解。为此,分别用卡马卡算法和基于卡马卡算法的关联预测法,求解柔性自动化车间最优生产计划问题,并编制了相应软件。最后通过算例研究,比较了卡马卡算法、基于卡马卡算法的关联预测法和Matlab中的线性规划法,结果表明,所提方法非常适合将不确定性环境中的随机产品需求计划,最优分解成由柔性自动化车间中各柔性制造系统执行的短期随机计划。     

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.