具有外包选择的闭环供应链切换模型及其鲁棒控制

建立了一类具有外包选择的闭环供应链切换系统模型,包括自行回收再制造和外包两个子系统,以及基于成本的切换信号向量。为了抑制闭环供应链系统在自行回收再制造和外包切换过程中产生的运作波动和牛鞭效应,应用鲁棒控制理论方法给出了供应链切换系统的控制律,分析了闭环供应链切换系统运作过程,并进行了控制律计算和系统仿真,验证了鲁棒控制律的有效性。     

一类参数和时滞不确定的闭环供应链动态模型与鲁棒H∞控制

建立了一类参数与时滞不确定的闭环供应链动态系统模型,包括具有参数不确定的产品回收模型、具有时滞不确定的再制造模型、具有参数和时滞不确定的第三方逆向物流模型三种典型的闭环供应链模型。分析了闭环供应链动态系统的鲁棒运作问题。针对闭环供应链动态系统运作过程中参数与时滞不确定干扰的问题,给出了解决供应链动态模型的鲁棒H∞控制策略及其线性矩阵不等式算法。通过库存状态的静态反馈控制,抑制了供应链动态系统中的不确定性干扰,使供应链运作达到理想状态。最后,以结合国内钢铁行业废钢回收运作状况为背景,进行了仿真计算,并验证了鲁棒H∞控制结果。     

考虑异质需求的再制造系统动态模型与鲁棒H_∞控制

针对消费市场对新产品和再制造产品存在的异质需求,建立了一组考虑产品需求可替代、时滞不确定性和需求不确定性的再制造系统动态模型,包括制造商自行回收模型、第三方回收模型以及再制造参数不确定的闭环供应链模型。分析了再制造系统的鲁棒运作,给出了这一组再制造系统动态模型的鲁棒控制策略和线性矩阵不等式算法。仿真计算表明,所提出的鲁棒控制策略能够有效抑制再制造系统运作过程中的不确定影响,使再制造系统达到稳定状态。     

再制造逆向物流的废旧产品回收模式分析

通过引入再制造的基本内涵及逆向物流的概念,在分析产品回收逆向物流的基础上,建立制造商主导回收、零售商主导回收和第三方服务商主导回收的模式,并讨论废旧产品回收、修复再制造的各种方案,目标是使各成员的收益最大.     

基于系统动力学的闭环供应链中的牛鞭效应

为了基于闭环供应链研究逆向物流对牛鞭效应的影响,运用系统动力学原理和VENSIM软件构建四级闭环供应链模型。通过改变回收比率、回收产品再制造比例和回收延迟证的仿真,证明逆向物流的存在可以减弱正向物流中的牛鞭效应,而且逆向物流的回收比率越高,回收再制造经过的节点越少,回收延迟越小,则逆向物流对牛鞭效应的减弱效果越明显。     

考虑歧视性回收的双渠道闭环供应链决策

针对零售商、第三方共同回收的双渠道闭环供应链决策问题,研究了制造商对零售商与第三方回收商采取的歧视性回收定价策略,并利用歧视系数讨论了歧视回收与公平回收策略的供应链利润、回收率的差异.研究表明,制造商和零售商利润关于差异回收策略存在对称性的特征,但系统回收率、第三方回收商利润会随第三方回收价格的增加而增加,为双渠道闭环供应链增加社会福利、提高废旧品回收率创造一条可行的道路.同时,制造商选择歧视回收还是公平回收策略,取决于回收价格、歧视系数、再制造成本节省之间的关系.     

双回收渠道下零售商主导闭环供应链决策模型

为研究双回收渠道下零售商主导闭环供应链的最优决策问题,针对由一个制造商、一个占主导地位零售商以及一个第三方回收商组成的闭环供应链系统,构建了相应的决策模型,并对闭环供应链成员及闭环供应链的整体利润进行了比较。研究表明在零售商主导的闭环供应链中,当第三方有利可图时,第三方负责回收对零售商是占优策略。当第三方无利可图时,无论是第三方还是零售商负责回收,零售商的最大利润是相同的。相对于第三方负责回收,由零售商负责回收对制造商和整个闭环供应链系统均是占优策略。     

零售商主导闭环供应链混合回收渠道选择决策

为研究奖惩机制下零售商主导闭环供应链中各参与主体的回收渠道最优决策问题,运用博弈论建立4种奖惩机制下具有竞争性的双渠道销售和多渠道回收闭环供应链模型,对比分析了4种混合回收模式下供应链成员利润、整个供应链系统的利润和回收水平。研究表明:废旧产品回收价格系数与回收渠道竞争系数之比较小时,制造商会选择制造商和第三方回收商这一混合回收渠道,此时供应链存在不稳定性;反之,制造商会选择制造商、零售商和第三方回收商这一混合回收渠道,此时供应链具有长期稳定性。单位奖惩因子和销售渠道模式不影响供应链各成员的最优回收渠道决策。     

顾客感知价值和回收质量不确定下的闭环共应链定价决策

鉴于上下游企业间的合作模式、顾客的感知价值和环境等不确定等因素,使闭环供应链的决策更加复杂多样化,考虑一个原始制造商和一个第三方回收商构成的闭环供应链,基于顾客感知价值和回收质量不确定的情况,通过构建利润模型并给出严格的数学证明,分析了在原始制造商垄断、Cournot双寡头博弈和Stackelberg博弈3种模式下闭环供应链新产品和再制造产品定价、市场需求和双方利润最优值,以及回收质量和顾客感知价值对决策变量的影响.通过数值仿真分析,验证了模型的有效性,并提出制造商补偿契约,为闭环供应链实现协调和进行决策提供了理论依据.     

考虑碳排放的闭环供应链收益波动规律分析

在考虑碳排放因子和成本因子下,构建由单一制造商、零售商和第三方物流服务商组成的闭环供应链系统,按照回收质量等级和回收商回收处置能力提出三种回收处置情境,即分别由零售商回收、制造商回收和第三方回收构建成的再制造闭环供应链模式。采用Stackelberg博弈论,在分散决策下比较分析不同情境中排放因子对批发价格、零售价格、回收价格的影响,进而研究碳排放对闭环供应链收益波动规律的影响。结果表明,批发价格和零售价格不受回收价格影响,而回收价格则与回收替代性、排放因子直接相关。通过数值仿真,分析各种成本因子、碳排放因子及路径长度作用下不同回收模式的总利润和总碳排放波动规律,从而为核心企业和政府采取积极的减排策略提供依据。     

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...     

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.     

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.     

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....     

Application of Feature Extraction through Convolution Neural Networks and SVM Classifier for Robust Grading of Apples

This paper proposes a novel grading method of apples,in an automated grading device that uses convolutional neural networks to extract the size,color,texture,an...     

分布动态载荷识别的抗噪处理

针对正交多项式频域法在用多种响应对矩形薄板进行载荷识别中抗噪性较差的问题,综合运用平均法、矩阵预处理和奇异值截断法等方法对之进行改善,并引入空间映射的思想,将该方法的应用范围拓展为复杂的模型.利用仿真算例,证实了该方法具有较好的抗噪性.     

基于MELTAC-N平台的核电厂安全级DCS环网研究与测试

针对工程实践中环网通讯相关问题的处理缺乏理论基础及国产化安全级DCS平台的开发缺乏成熟经验借鉴问题,对基于MELTAC-N平台核电厂安全级DCS环网的软硬件实现进行了研究。提出了安全级DCS环网双环网冗余设计、光切换开关设计等硬件设计方法,以及以RPR协议为基础,采用全数据收发策略的软件设计方法。在CPR1000安全级DCS平台上对安全级DCS环网的可靠性及实时性进行了评价,并进行了容错能力、响应时间及响应时间稳定性测试验证实验。结果表明,基于MELTAC-N平台安全级DCS环网软硬件设计具有较好的容错能力及响应时间稳定性。     

The laboratory simulation of abrasive wear

Abrasive wear has long been recognised as one of the most potentially serious tribological problems facing the operators of many types of plant and machinery; several industrial surveys have indicated that wear by abrasion can be responsible for more than 50% of unscheduled machine and plant stoppages. Locating the operating point of a tribological contact in an appropriate operational ‚map’︁ can provide a useful guide to the likely nature and origins of the surface degradation experienced in use, though care must be exercised in choosing the most suitable parameters for the axes of the plot. Laboratory testing of materials and simulations of machine contacts are carried out for a number of purposes; at one level for the very practical aims of ranking candidate materials or surface hardening treatments in order of their wear resistance, or in an attempt to predict wear lives under field conditions. More fundamentally, tests may be aimed at elucidating the essential physical mechanisms of surface damage and loss, with the longer term aim of building an analytical and predictive model of the wear process itself. In many cases, component surface damage is brought about by the ingress of hard, particulate matter into machine bearing or sealing clearances. These may be running dry although, more usually, a lubricant or service fluid is present at the interface. A number of standardised wear test geometries and procedures have been established for both two- and three-body wear situations, and these are briefly described. Although abrasive wear is often modelled as following an ‚Archard’︁ equation (i.e. a linear increase in material loss with both load and time, and an inverse dependence on specimen hardness) both industrial experience and laboratory tests of particularly lubricated contacts show that this is not always the case: increasing the hardness differential in an abrasively contaminated lubricated pair may not always reduce the rate of damage to the harder surface.     

ANGULAR DISTORTION ALLOWABLE VALUE AND ASSESS METHOD OF WELD ON COKE TOWER

A graph as the new engineering method for estimate the safety of bulging deformation of coke tower is proposed. Through stresses analysis of circumferential weld of coke tower and comparing the stresses produced by pressure with heat stress of steady state, residual stress, bending stress produced by both itself weight and wind loads, it showed that the stresses produced by pressure on the angle distortion are the main factor of equivalent stress of the combined stress. After comparing four kinds of stress controlling conditions, the relation to stress with depth of angular distortion, grade of curvature of angular distortion and half of region of angular distortion has been inferred. Graph of deformation allowable value of coke tower for different condition by angular distortion and half of region of angular distortion has been plotted. The five steps for its engineering use have been explained. The lighter the grade of curvature is, the larger of bulge allowance, may be, and the bigger of depth of angular distortion may pose too. For the coke tower with a popular structure of Dg 5 400 mm×28 mm, the result by graph is nearly more than the result of two formulas formed by other research, the error is less than 7.0%. But, the graph can be easily applied to different size of angular distortion.