k-分支星状树的第二几何算术指标

数学化学中,第二几何算术指标是新近提出的一个图的拓扑指标,它与Szeged指标和点PI指标具有紧密关系.如果树的一个顶点υ的度大于等于3,则称顶点υ是其一个分支点.通过树的第二几何算术指标的一个增加或减少的变换,刻画了k-分支星状树的第二几何算术指标的最值,同时确定了相应的极图.     

Computation on the Topological Indices of Hyaluronic Acid

In this paper, we investigate the topological indices of Hyaluronic Acid. By constructing the graph of molecular structure and using the edge partitioning technique, we determine the general Randi\''c index, first and second Zagreb polynomial indices, general sum-connectivity index, ordinary geometric-arithmetic index and general harmonic index of Hyaluronic Acid.     

Extremal hexagonal chains concerning largest eigenvalue

In this paper, we define a roll-attaching operation of a hexagonal chain, and prove Gutman’s conjecture affirmatively by using the operation. The idea of the proof is also applicable to the results concerning extremal hexagonal chains for the Hosoya index and Merrifield-Simmons index     

受单面约束的非完整力学系统的运动方程

给出同时受有单面完整约束和单面非完整约束的非完整力学系统的运动方程,并举例说明其应用     

单侧检验的局限性及其解决方法

根据单侧检验的思想方法,揭示了单侧检验的局限性,给出了识别局限性的两个命题,并提出了对于这种局限性的解决方法。     

Geometric representation of detachment conditions in systems with unilateral constraint

Mechanical systems with unilateral constraints that can be represented in the contact mode on the phase plane are considered. On the phase plane we construct domains that satisfy the following conditions 1) a detachment from the constraint is impossible; 2) the sign of the constraint reaction corresponds to its unilateral character. These conditions are equivalent for an ideal constraint [1, 2], but they can differ in the presence of friction [3]. Trajectories without detachments belong to intersections of these domains. A circular disc moving on a horizontal support with viscous friction and a disc with the sharp edge moving on an icy surface [4, 5] are considered as examples. Usually for the control of contact conservation one uses only the second condition from above, which can lead to invalid qualitative conclusions.      

A mixed finite element method for the unilateral contact problem in elasticity

In this paper, we provide a new mixed finite element approximation of the varia-tional inequality resulting from the unilateral contact problem in elasticity. We use the continuous piecewise P2-P1 finite element to approximate the displacement field and the normal stress component on the contact region. Optimal convergence rates are obtained under the reasonable regularity hypotheses. Numerical example verifies our results.     

Mixed finite element methods for unilateral problems: convergence analysis and numerical studies

In this paper, we propose and study different mixed variational methods in order to approximate with finite elements the unilateral problems arising in contact mechanics. The discretized unilateral conditions at the candidate contact interface are expressed by using either continuous piecewise linear or piecewise constant Lagrange multipliers in the saddle-point formulation. A priori error estimates are established and several numerical studies corresponding to the different choices of the discretized unilateral conditions are achieved.

     

Matching product architecture with supply chain design

Product architecture is typically established in the early stages of the product development (PD) cycle. Depending on the type of architecture selected, product design, manufacturing processes, and ultimately supply chain configuration are all significantly affected. Therefore, it is important to integrate product architecture decisions with manufacturing and supply chain decisions during the early stage of the product development. In this paper, we present a multi-objective optimization framework for matching product architecture strategy to supply chain design. In contrast to the existing operations management literature, we incorporate the compatibility between the supply chain partners into our model to ensure the long term viability of the supply chain. Since much of the supplier related information may be very subjective in nature during the early stages of PD, we use fuzzy logic to compute the compatibility index of a supplier. The optimization model is formulated as a weighted goal programming (GP) model with two objectives: minimization of total supply chain costs, and maximization of total supply chain compatibility index. The GP model is solved by using genetic algorithm. We present case examples for two different products to demonstrate the model’s efficacy, and present several managerial implications that evolved from this study.     

Modified offensive earned-run average with steal effect for baseball

This short article introduces and studies a modified offensive earned-run average (MOERA) index which is based on a stationary Markov chain and evaluates the contribution of a player in baseball. An original offensive earned-run average (OERA) index does not consider the effect of stealing. The MOERA index proposed here includes the effect. Some examples are presented for Japanese professional baseball players.     

Pricing in a supply chain for auction bidding under information asymmetry

We examine a supply chain in which a manufacturer participates in a sealed-bid lowest price procurement auction through a distributor. This form of supply chain is common when a manufacturer is active in an overseas market without establishing a local subsidiary. To gain a strategic advantage in the division of profit, the manufacturer and distributor may intentionally conceal information about the underlying cost distribution of the competition. In this environment of information asymmetry, we determine the equilibrium mark-up, the ex-ante expected mark-up and expected profit of the manufacturer and the equilibrium bid of the distributor. In unilateral communication, we demonstrate the informed agent’s advantage resulting to higher mark-up. Under information sharing, we show that profit is equally shared among the supply chain partners and we explicitly derive the mark-up when the underlying cost distribution is uniform in [0, 1]. The model and findings are illustrated by a numerical example.     

基于因子分析的优质猪肉供应链中超市评价指标体系研究

以超市为销售商构建优质猪肉供应链是解决目前我国猪肉产品质量安全问题的有效途径。本文在评述国内外关于供应链合作伙伴评价指标体系构建方法的基础上,利用因子分析法构建并论证了一套适合于优质猪肉供应链中超市选择的评价指标体系,包括质量保障、合作程度、空间区位和管理水平等4类11个具体指标。     

An economic evaluation model of supply chain flexibility

With the advent of the supply chain management concepts, business communities have been realizing that being competitive as a single company is no longer adequate; instead, competitiveness requires consideration of all channels in the supply chain. Despite its importance, the availability of the literature addressing supply chain flexibility is still limited to date. Although relationships between various types of flexibilities have been established, the degree to which one type of flexibility affects the other types and the system performance remains to be investigated. In particular, there is a lack of rigorous analytical models elucidating the relationships between the degree of flexibility in a system and the system level of performance. In this paper, a supply chain flexibility model is developed comprising labor flexibility, machine flexibility, routing flexibility, and information technology, with total system flexibility measured by an economic index. Outputs from the model can assist in making suitable production decisions to produce multiple products under an uncertain environment. Example solutions are given. This paper can help economic evaluation when supply chain flexibility and the factors affecting flexibility are to be improved. It can also assist in making supply chain flexibility-promotion decisions.     

政府补贴下闭环供应链回收渠道的选择策略

本文考虑由单一制造商、单一零售商以及单一第三方构成的闭环供应链系统,主要研究其回收渠道的选择问题,并综合分析政府补贴政策对不同主体回收策略选择的影响。本文建立了不同主体回收的决策模型,对集中决策和分散决策下的最优策略进行了理论分析,并通过数值实验验证了如下理论结果:在政府补贴的不同区间内,决策者(政府、消费者和政策制定者等)所选择的回收渠道可能会截然不同;政府补贴越少,决策者越倾向于选择零售商回收;政府补贴越多,决策者则越倾向于选择第三方回收。     

基于改进EAHP的装备采购供应链质量绩效评价

针对装备采购供应链质量绩效评价指标体系不能真实反映供应链质量状况和评价方法不够合理的问题,基于平衡计分卡模型框架建立了装备采购供应链质量绩效评价指标体系,提出了一种新的改进可拓层次分析法(EAHP),用于评价供应链质量绩效。该方法通过个体指标权重向量与群体指标权重向量之间的贴近度确定初始专家权重,并通过引入修正参数的序关系分析法(G1)来多轮修正专家权重分配,克服了传统EAHP在群决策中集结专家判断信息后一致性检验难以通过的问题。计算实例表明该方法能有效集结群决策信息,并减少偏差较大的决策信息带来的不良影响。     

Minimal hexagonal chains with respect to the Kirchhoff index

Let G be a connected graph. The resistance distance between any two vertices of G is equal to the effective resistance between them in the corresponding electrical network constructed from G by replacing each edge with a unit resistor. The Kirchhoff index of G is defined as the sum of resistance distances between all pairs of vertices. Hexagonal chains are graph representations of unbranched catacondensed benzenoid hydrocarbons. It was shown in Yang and Klein (2014) [30] that among all hexagonal chains with n hexagons, the linear chain $L_n$ is the unique chain with maximum Kirchhoff index. However, for hexagonal chains with minimum Kirchhoff index, it was only claimed that the minimum Kirchhoff index is attained only when the hexagonal chain is an “all–kink” chain. In this paper, by standard techniques of electrical networks and comparison results on Kirchhoff indices of $S,T$-isomers, “all-kink” chains with maximum and minimum Kirchhoff indices are characterized. As a consequence, hexagonal chains with minimum Kirchhoff indices are singled out.     

事件空间中单面非Chetaev型非完整系统的Noether定理

研究事件空间中单面非Ｃｈｅｔａｅｖ型非完整系统的Ｎｏｅｔｈｅｒ定理,首先给出了系统的Ｄ’Ａｌｅｍｂｅｒｔ－Ｌａｇｒａｎｇｅ原理;其次基于该原理在无限小变换下的不变性,研究了非Ｃｈｅｔａｅｖ型非完整系统的Ｎｏｅｔｈｅｒ定理及逆定理;最后举例说明结果的应用。     

基于投影寻踪-随机森林的制造企业供应链稳定性评价

基于扎根理论提取制造企业供应链稳定性影响因素,鉴于因素的随机性和模糊性特征,引入云模型,将定性概念转化为定量数据,从众多影响因素中筛选出重要因素,构建制造企业供应链稳定性评价指标体系。采用加速遗传算法对建立的投影寻踪模型进行求解,确定指标权重与稳定性评价值。利用随机森林方法根据评价值划分供应链稳定性类型,检验评价方法科学性,并确定当前制造企业供应链稳定性的整体状态,据此提出优化制造企业供应链稳定性建议。     

供应链融资模式下中小企业信用风险评估研究——基于左右得分的模糊TOPSIS算法

中小企业信用风险评价是供应链融资实现的关键。本文在对已进行的研究总结的基础上,建立了一套比较完整的评价指标体系,然后运用DEA、AHP和基于左右得分的模糊TOPSIS相结合的评价方法对中小企业在供应链融资中的信用风险进行评价。最后,将方法成功应用到具体实例,结果表明将AHP方法和左右得分模糊TOPSIS结合应用到多层次指标评价问题是合理、可行的,能够为供应链融资信用风险评估提供决策依据。     

Finite element analysis of a static contact problem with Coulomb friction

A unilateral contact problem with a variable coefficient of friction is solved by a simplest variant of the finite element technique. The coefficient of friction may depend on the magnitude of the tangential displacement. The existence of an approximate solution and some a priori estimates are proved.