基于计算实验的考虑零售商风险偏好的供应商定价研究

为了研究一个风险中性供应商和多个风险偏好的竞争零售商组成的两级供应链供应商定价决策,考虑零售商存在商品错放和耗损两类因素,基于供应商对批发价和回购价的调整机制及零售商对订货量的调整规则,建立了供应链各成员的两周期收益模型,并采用计算实验方法进行分析。研究结果表明,强风险偏好型零售商的平均收益高于弱风险偏好型零售商的平均收益;仅调整批发价策略将导致供应链"断链";同时调整批发价和回购价策略使供应链成员的收益波动较大,此时供应商获得的平均收益最大,零售商的订货量和平均收益均最小。     

考虑损失厌恶零售商的混合渠道库存决策问题

针对零售商损失厌恶行为往往导致其决策偏离最优的现象,从顾客渠道偏好和零售商损失厌恶因素角度研究混合渠道的库存决策。基于渠道偏好构建了风险中性制造商和损失厌恶零售商的混合渠道库存决策模型,探讨了独立库存和零售商集中库存下制造商和零售商的最优库存策略,并通过数值模拟分析需求不确定性、损失厌恶及决策方式等因素对库存策略的影响。研究表明,独立库存模式下的集中决策是分散决策的Pareto改进,零售商集中库存模式下的集中决策提高了制造商和供应链的利润,却降低了零售商收益;损失厌恶零售商的订货量随需求不确定性增大,呈现先增后减趋势;对于零售商和供应链,零售商集中库存模式占优,面临损失厌恶零售商,制造商倾向于选择独立库存模式以维护自身利益。数值分析进一步表明,当制造商能提供合理利润共享契约并适当调节库存水平时,零售商集中库存模式将比独立库存模式更能协调具有损失厌恶零售商的混合渠道。     

不确定环境下具有损失厌恶偏好零售商的供应链协调

为实现供应链的整体绩效最大,以零售商面临的供应与需求不确定性为前提,探讨由损失厌恶零售商和风险中性供应商组成的供应链契约协调设计问题。研究表明,损失厌恶零售商在批发价契约下的订货量小于系统最优订货量;供应商通过"回购+弹性数量"的组合式契约激励零售商增加订购量、实现供应链协调;当契约参数被限制时,其协调能力优于单一的回购或弹性数量契约。通过数值分析验证了该协调机制的有效性,阐明了零售商的风险厌恶程度和供应不确定因素对协调参数及供应链绩效的影响。     

提前期可控下的供应链交易信用协调模型

为研究可控提前期对供应链最优决策的影响,基于交易信用契约,研究了由单个供应商与单个零售商组成的两级供应链库存协调问题。假设补货提前期可控,得到分散式、集中式和协调模型中供应商与零售商的最优策略组合。研究表明:基于交易信用和批发价格溢价的协调机制共同作用不但提高了整个供应链的绩效水平,而且实现了额外利润在供应商与零售商之间的合理分配;协调的批发价格随着零售商资金机会成本的增加而增加,随着供应商资金机会成本的增加而减少;交易信用契约的协调区间随着零售商资金机会成本的增加而增大,随着供应商资金机会成本的增加而减小。通过算例分析考察了需求标准差和单位缺货成本对供应链最优策略与系统利润的影响,结果表明,该模型不但提高了整个供应链的绩效水平,而且实现了额外利润在供应商与零售商之间的合理分配。     

考虑消费者退货决策的两阶段电子商务供应链制造商回购策略

为了优化两阶段电子商务供应链,避免由于信息不对称导致的供应链效率低下,研究了一类在生命周期中采用C2B-B2C两阶段模式进行销售的电子商务供应链模型,分别对第一阶段消费者根据零售商退货补偿价格制定的退货决策、第一阶段消费者退货决策对第二阶段零售商的最优订货量与最优利润的影响进行了分析,发现C2B-B2C电子商务供应链两阶段具有不同的零售商的最优退货价格。对零售商最优退货价格的分析发现,制造商能够通过回购和对退货进行再制造来调节零售商最优退货价格,实现两阶段的协调。在此基础上对不同类型的制造商回购合同进行分析,结果表明,差异化回购合同能够更有效地协调两阶段供应链;另外,在产品非易逝且消费者愿意接受再制造产品的前提下,制造商提供再制造的差异化回购合同能够更好地增进供应链的整体利润。     

随机产出与需求条件下的响应性定价策略

为了应对供需不确定带来的问题,构建了供应商产出和市场需求均不确定情况下的两级供应链定价模型。通过三阶段Stackelberg博弈分析,探讨了响应性定价策略下零售商的最优订货量和产品定价决策以及供应商的最优分销价格,分析了响应性定价策略与清仓定价策略的差别以及随机产出率和潜在市场需求对响应性定价策略价值的影响。研究结果表明,响应性定价能提高零售商的利润,但有可能降低供应商的利润;产出率越大、潜在市场需求越小时响应性定价对供应商和零售商的价值越大,而产出率和潜在市场需求的不确定性对响应性定价策略价值的影响具有非单调性。     

考虑渠道公平的双渠道二层供应链网络均衡策略

为分析渠道公平感知对双渠道供应链决策的影响,针对上层为单个制造商,下层为多个零售商和需求市场的双渠道二层供应链网络,运用Stackelberg博弈理论和FS模型分析零售商渠道公平感知对供应链均衡策略和效用的影响.研究表明,如果零售商一味要求提高零售渠道的利润分成,则不能实现利润最大化.制造商应注重协调传统和直销两个渠道的利润分配比,不能仅追求直销渠道的高利润而忽视零售商的渠道公平感知,以使供应链整体利润达到最优.     

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。     

第三方回收闭环供应链的广告与定价决策模型

为了研究不同广告模式对第三方回收闭环供应链定价策略的影响。在广告营销效率因子及广告成本因子的双因素假设下,构建了3种广告模式下第三方回收闭环供应链的定价决策模型。研究表明:无论零售商还是制造商单独广告,都不影响系统中各成员的最优定价策略,且第三方回收商及系统整体的利润不变,但主导零售商的利润并不一定总大于制造商的利润。联合广告模式只对主导零售商有利,对闭环供应链系统其他成员及整体都均不利。无论何种广告模式下,较之主导零售商及制造商,第三方回收商的利润总是最小的。     

随机需求多渠道供应链Stackelberg协调博弈分析

研究具有随机需求和涉及产品转移成本的,由一主导制造企业、电子零售商和传统零售商构成的多渠道供应链协调问题。通过建立Stackelberg博弈模型,分析了集中决策和分散决策模式下多渠道供应链中成员间的价格竞争和产品转移成本对企业生产计划与定价决策的影响;构建了多渠道供应链协调的激励惩罚机制。研究表明,通过该激励惩罚机制可使零售商的最优订货量与集中决策下的最优订货量相等,而通过与支付转移契约的组合运用可实现多渠道供应链的完全协调。     

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。     

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。     

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...     

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.     

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。     

RLS and LMS blind adaptive multi-user detection method and comparison in acoustic communication

RLS and LMS blind adaptive multi-user detection algorithm and multi-user detector was proposed to solve the problem of multi-user signal detection problem encountered in underwater acoustic communication networks.In simulation analysis,RLS and the LMS blind adaptive multi-user detector were designed and tested for synchronous and asynchronous multi-user communication process.The results of SIR comparison and MMSE comparison show that,both of the two methods can realize blind adaptive detection when any user change in multi-user communication,during this process,the training communication sequences are not needed.The RLS algorithm has about 5 dB higher in SIR compared with LMS algorithm,and the convergence velocity of RLS algorithm is also higher than LMS algorithm when the communication users change.RLS algorithm has better ability in multi-user detection than that of LMS algorithm,and it has great attraction and guiding significance for solving the problem of multiple access interference(MAI) in multi-user communication.     

Robust Impedance Control of Robots Using an Adaptive Interaction Force Observer

For robot interaction control,the interaction force between the robot and the manipulated object or environment should be monitored.Impedance control is a type ...     

Research on key techniques of expendable conductivity temperature depth measuring system

This paper analysis the developing of expendable conductivity temperature depth measuring system(XCTD)and introduce its principle of measuring about temperature,salinity and depth of ocean.Some key techniques are put forward.According to the real needs of XCTD,conductivity sensor with high sensitivity is designed by principle of electromagnetic induce,the ocean conductivity from induced electromotive force has been calculated.Adding temperature correction circuit would help to reduce error of conductivity measurement because of sharply changing temperature.Advanced temperature measuring circuit of high precision and the constant current source is used to weaken effect of self-heating of resistance and fluctuation of the source.On respect of remote data transmission,LVDS is a good choice for the purpose of guarantee the quality of data transmitted and the transmission distance is reaching to thousand meters in the seawater.Modular programming method is also brought into this research aimed at improve the stability,reliability and maintainability of the whole measuring system.In February,2015,the trials in South China Sea demonstrate that the developed XCTD realize effective measurement at a speed of 6 knots and detection depth at 800 m.The consistency coefficient of the acquired data is greater than 0.99 and the success rate of probe launching is above 90%.     

CHARACTERISTCS OF FLUID FILM IN OPTIMIZED SPIRAL GROOVE MECHANICAL SEAL

In order to investigate the sealing performance variation resulted from the thermal deformation of the end faces, the equations to calculate the fluid film pressure distribution, the bearing force and the leakage rate are derived, for the fluid film both in parallel gap and in wedgy gap. The geometrical parameters of the sealing members are optimized by means of heat transfer analysis and complex method. The analysis results indicate that the shallow spiral grooves can generate hydrodynamic pressure while the rotating ring rotates and the bearing force of the fluid film in spiral groove end faces is much larger than that in the flat end faces. The deformation increases the bearing force of the fluid film in flat end faces, but it decreases the hydrodynamic pressure of the fluid film in spiral groove end faces. The gap dimensions which determine the characteristics of the fluid film is obtained by coupling analysis of the frictional heat and the thermal deformation in consideration of the equilibrium condition of the bearing force and the closing force. For different gap dimensions, the relationship between the closing force and the leakage rate is also investigated, based on which the leakage rate can be controlled by adjusting the closing force.