关于向量标号单纯算法的基本理论——对《解法》一书的若干意见

§1.引言 在《非线性方程组的数值解法》(简称解法)的第七章和第四章中,有些论述不够妥当. 考虑到一些院校已经或准备选用它作为计算数学专业研究生和高年级学生的教材和参考书,影响较大,故将自己的意见提出来,与作者和读者商榷.     

PL fibrations are fibrations in the PL category

Proper PL maps which are Hurewicz fibrations have the covering homotopy property in the PL category.     

Joint logistics and financial services by a 3PL firm

Integrated logistics and financial services have been practiced by third party logistics (3PL) firms for years; however, the literature has been silent on the value of 3PL firms as credit providers in budget-constrained supply chains. This paper investigates an extended supply chain model with a supplier, a budget-constrained retailer, a bank, and a 3PL firm, in which the retailer has insufficient initial budget and may borrow or obtain trade credit from either a bank (traditional role) or a 3PL firm (control role). Our analysis indicates that the control role model yields higher profits not only for the 3PL firm but also for the supplier, the retailer, and the entire supply chain. In comparison with a supplier credit model where the supplier provides the trade credit, the control role model yields a better performance for the supply chain as long as the 3PL firm’s marginal profit is greater than that of the supplier. We further demonstrate that, for all players, both the control role and supplier credit models can outperform the classic newsvendor model without budget constraint.     

平滑的PL和分位点过程之间距离的渐近分布(英文)

在随机右删失情况下,我们证明了基于平滑ＰＬ估计和平滑ＰＬ分位点估计的Ｂａｈａｄｕｒ－Ｋｉｅｆｅｒ型过程的弱极限定理     

第3方冷链物流配送路径优化研究

根据冷链物流配送具有的特殊性,进一步探索冷链物流配送优化研究的方案.在保证货物不超载的情况下,建立以一个冷链配送中心、多个顾客的冷链物流的配送数学模型,用改进遗传算法加以分析求解,并采用Matlab软件对算法进行编程,最后通过算例进行验证.得到如下结论:利用改进遗传算法得到的最优配送路线优于标准遗传算法求解结果.     

基于直觉模糊集的电子商务第三方物流选择

论文分析了电子商务第三方物流供应商的特点,提出电子商务第三方物流选择评估指标系统。由于指标评估的不确定性、语言描述性,以及信息的不完全性,引入直觉模糊集恰当地刻画已有信息关于相应决策指标的支持、反对,以及不确定状态,提出直觉模糊集的均衡数量集中函数以及均衡数量离散函数,并在此基础上,定义直觉模糊集合成函数,建立基于直觉模糊集的综合评估方法。并通过实例说明该模型的有效性。     

Uniqueness of PL Minimal Surfaces

Using a standard fact in hyperbolic geometry, we give a simple proof of the uniqueness of PL minimal surfaces, thus filling in a gap in the original proof of Jaco and Rubinstein. Moreover, in order to clarify some ambiguity, we sharpen the definition of PL minimal surfaces, and prove a technical lemma on the Plateau problem in the hyperbolic space.     

PL fibrator properties of partially aspherical manifolds

Approximate fibrations form a useful class of maps. By definition fibrators provide instant detection of maps in this class, and PL fibrators do the same in the PL category. This paper formalizes a natural concept of partial asphericity and establishes fibrator properties of certain partially aspherical closed manifolds. One consequence is that any connected sum of aspherical PL manifolds with residually finite fundamental groups is a codimension-(2n−2) PL fibrator.     

PL embeddings ofPL manifolds into some Euclidean spaces

The main result in this paper is the following: Theorem.Assume that W is a k-connected compact PL n-manifold with boundary, BdW is (k–1)-connected, k1(BdW is 1-connected for k=1), 0h2k, 2n–h>5and there exists a normal block (n-h-1)-bundle vover W, then

The Topological Correctness of PL Approximations of Isomanifolds

Foundations of Computational Mathematics - Isomanifolds are the generalization of isosurfaces to arbitrary dimension and codimension, i.e. manifolds defined as the zero set of some multivariate...     

Effectiveness—non effectiveness in semialgebraic and PL geometry

Oblatum 14-IV-1989 &; 25-I-1990     

Codimension Two PL Embeddings of Spheres with Nonstandard Regular Neighborhoods

For a given polyhedron K(?)M,the notation RM(K)denotes a regular neigh- borhood of K in M.The authors study the following problem:find all pairs(m,k) such that if K is a compact k-polyhedron and M a PL m-manifold,then R_M(f(K))≌R_M(g(K))for each two homotopic PL embeddings f,g:K→M.It is proved that R_S~(k 2)(S~k)(?)S~k×D~2 for each k(?)2 and some PL sphere S~k(?)S~(k 2)(even for any PL sphere S~k(?)S~(K 2)having an isolated non-locally flat point with the singularity S~(k-1)(?) S~(k 1)such thatπ_1(S~(k 1)-S~(k-1))(?)Z).     

On the geometry of paths generated by PL homotopy methods

PL homotopy methods are effective numerical methods for highly nonlinear problems. It is widely believed that the feasibility of a PL homotopy method depends on the nondegeneracy condition that the zero set (or the fixed point set in the case of finding fixed points instead of zeroes) of the PL approximation of the homotopy does not intersect the triangulation's skeletons of co-dimensions two and above. This paper shows that, although the sections of the PL approximation's zero set tracked by the PL homotopy method are of dimension one (while other sections may have higher dimensions), the paths generated by the pivoting method are potentially and essentially of dimension two. It makes pathcrossing a safe thing. Thus, this paper first sets up the without exception feasibility of PL homotopy methods geometrically.This work is supported in part by the Foundation of Zhongshan University Advanced Research Centre.     

Combinatorial fiber bundles and fragmentation of a fiberwise PL homeomorphism

With a compact PL manifold X we associate a category . The objects of are all combinatorial manifolds of type X, and morphisms are combinatorial assemblies. We prove that the homotopy equivalence

A PL homotopy for finding all the roots of a polynomial

This paper presents a constructive method which gives, for any polynomialF(Z) of the degreen, approximate values of all the roots ofF(Z).. The point of the method is on the use of a piecewise linear function (Z, t) which approximates a homotopyH(Z, t) betweenF(Z) and a polynomialG(Z) of the degreen withn known simple roots. It is shown that the set of solutions to (Z, t) = 0 includesn distinct paths,m of which converges to a root ofF(Z) if and only if the root has the multiplicitym. Starting from givenn roots ofG(Z), a complementary pivot algorithm generates thosen paths.This work was supported by grants from Management Science Development Foundation and Takeda Science Foundation.     

非对称信息下基于梯度效应的4PL外包激励机制

借鉴报酬激励的梯度效应,运用委托代理理论,研究了信息不对称条件第四方物流外包时对第三方物流的激励问题.研究结果表明:第三方物流获得高业绩的可能性越小即任务挑战性越强,第四方物流应该给予其的激励越多;激励梯度使激励契约与任务属性、第三方物流能力与效益以及第四方物流付出的代价密切关联;激励梯度的存在不影响第四方物流努力水平.     

4PL模式下供应链资源整合的多回合博弈决策分析

为了对4PL模式下供应链资源整合的收益与风险关系进行系统量化研究,本文从整合成本输入及整合收益输出关系入手,在整合运作框架基础上,从参与整合活动主、客体双方的整合收益与风险的系统性权衡与量化角度对资源整合的多回合博弈决策问题进行了分析。通过将博弈过程合理分段,并采用模糊隶属函数分别描述博弈子过程特征和资源个体的整合收益与风险指标变动特征,提出了以多回合博弈过程为变量的综合评价决策方法,真实地在柔性整合决策过程中反映了博弈双方的主、客观状况及其在不同谈判阶段的获利与风险心理。最后,通过算例验证,决策方法可行、有效。