Supply chain coordination with two-part tariffs under information asymmetry

Supply chain coordination literature indicates that two-part tariff contracts cannot coordinate a supply chain with a supplier and a retailer under information asymmetry, but can coordinate the channel under full information, while leaving the retailer zero profit. Motivated by the practice of Costco Business Centres, we incorporate customer heterogeneity, near-saturated retail market and asymmetric information into a stylised model. The retailer has the knowledge of customer heterogeneity while the supplier does not. The supplier, on the other hand, designs a menu of two-part tariffs for the retailer to choose from. We have found that two-part tariffs can coordinate the supply chain under asymmetric information, while leaving the retailer a positive profit. In addition, a one-size-fits-all two-part tariff can coordinate the supply chain at equilibrium, i.e. there is no need for the supplier to design different two-part tariffs for the retailer who may possess different types of information.     

非对称异构信息网络的模糊推荐算法

传统的协同过滤推荐算法存在普遍的数据稀疏性问题;应用于推荐算法领域的异构信息网络模型对对象的相似关系认定通常是对称的,这种对称关系的认定在实际问题的处理中存在局限性。为解决上述问题,提出一种非对称异构信息网络的模糊推荐算法。该算法利用模糊集理论在处理用户喜好程度方面的优势,从模糊的信息种获取用户的准确偏好,根据异构信息网络中元路径的丰富语义信息,获取不同角度的用户关联,在相似度计算中引入对象关系的非对称系数,对不同特征元路径的计算结果进行加权,以此提高用户之间相似关系的准确度,通过矩阵分解的方法实现评分预测。实验结果表明,该算法有效解决了数据稀疏性问题,提升了推荐精度。     

旅游市场信息不对称的分析与对策

以旅游市场为焦点，分析了旅游市场存在信息不对称的原因，以及由此产生的消极后果，从信息经济学和公共经济学原理的角度提出了几点建议。     

Simulation of air flow in the IEA Annex 20 test room—validation of a simplified model for the nozzle diffuser in isothermal test cases

The modeling of air supply devices has been identified from the International Energy Agency (IEA) Annex 20 project as one of the most important problems in applying computational fluid dynamics (CFD) to predict air flow pattern and air distribution in buildings, and the complicated HESCO nozzle diffuser used in the IEA Annex 20 test room has been proved to be particularly difficult to model. In a previous study, a simplified model for this diffuser was developed and validated against experimental data. It has been shown that this model can yield good prediction for the wall jet flow issued from the diffuser, but whether this model is capable of correctly predicting the global flow pattern in the whole test room was not known. In this paper, the benchmark data of the IEA Annex 20 Test Cases B2 and B3 were used to evaluate the performance of the model for the prediction of the global air flow pattern in the test room. It was demonstrated that this model can predict the air flow pattern in the whole test room for both the Test Cases B2 and B3 with reasonable accuracy. The significance of a velocity correction when comparing the numerical prediction with experimental data obtained using omni-directional anemometers was also discussed.     

带裙房高层建筑框-筏基础筏板厚度的探讨

本文利用高层建筑上部结构———基础———地基三者共同作用理论 ,从控制基础不均匀沉降角度出发 ,对中硬地层地区高层建筑主楼和裙房不设缝时基础筏板厚度进行了研究 ,得到了一些有益的结论     

拱坝基础不对称性影响研究

结合国内外一些由于两岸基础不对性造成拱坝的影响实例，基于多次的地质力学模型试验和三维有限元计算分析，就锦屏一级高拱坝地形、地质条件不对性对拱坝整体稳定的影响和加固措施的选择进行了探讨。试验和数值结果均显示：上游坝踵拉应力偏大，下游出现拉应力。坝体应力不对称；左岸变形大于右岸，并且出现斜裂缝，超载能力偏低。通过研究，建议采用垫座及锚索等加固措施，使大坝整体处于平稳状态。     

Thermal expansion and mechanical properties of pure magnesium containing zirconium tungsten phosphate particles with negative thermal expansion

The magnesium composites containing Zr₂(WO₄)(PO₄)₂ (ZWP) particles with negative thermal expansion (NTE) were synthesized. Dense, unreacted Mg/ZWP composites were fabricated by extruding the two component powders. The coefficient of thermal expansion (CTE) and the mechanical properties of the composites were examined. The CTE of Mg/ZWP composites decreased with an increase in the amount of ZWP in the composites, though the effect was not significant probably because of the low bulk modulus of ZWP. Although there was a tension–compression asymmetry in the room temperature yield strength of Mg without ZWP, the difference reduced in the composites. The decreased asymmetry of yield behavior was suggested to be resulting from the tensile residual stress in the matrix produced during fabrication process because of the NTE of ZWP.     

MONTE CARLO SIMULATION OF SPIN-POLARIZED SECONDARY ELECTRONS FROM IRON

A Monte Carlo model considering the electron spin direction and spin asymmetry has been developed. The energy distribution of the secondary electron polarization and the primary energy dependence of the polarization from Fe are studied. The simulation results show that: (1) the intensity of the spin-up secondary electrons is larger thanvthat of thevspin-down secondary electrons, suggesting the secondary electrons are spin polarized; (2) the spin polarization of secondary electrons with nearly zero kinetic energy is higher than the average valance spin polarization, Pb=27% for Fe. With increasing kinetic energy, the spin polarization of the secondary electrons decreases to the value of Pu remaining constant at higher kinetic energies; (3) the spin polarization increases with an increase in the primary energy and reaches a saturation value at higher primary energy in both the Monte Carlo simulation and experimental results.     

非对称式行星齿轮分动器

阐述传统分动器的不足之处,以奔驰车为例,详细介绍带有差速功能的非对称式行星齿轮分动器的特点、工作原理、扭矩分配特性、差速特性及在特殊行驶条件下的使用。     

Asymmetric Synthesis with N‐Heterocyclic Carbenes. Application to the Copper‐Catalyzed Conjugate Addition

Chiral N‐heterocyclic carbenes are good ligands for the copper‐catalyzed conjugate addition of dialkylzinc reagents to various Michael acceptors. With as little as 4% of chiral ligand, the enantioselectivity may reach 93% on cycloheptenone.