服务管理差距与服务质量差距之间关系模型的研究

在服务质量差距分析模型的基础上,基于服务管理差距和服务质量差距测评体系,运用结构方程建模方法,建立了企业内部服务管理差距与顾客感知服务质量差距之间的关系路径图和关系模型,定量研究了四个服务管理差距对服务质量差距的影响关系、服务管理差距测评指标对相应的四个服务管理差距的影响关系,为顾客感知服务质量差距的测量和评价提供了技术和方法.结合某外语培训学校服务管理实际进行了案例研究,为企业服务质量的诊断和改进提供了科学依据.     

The Joint Determination of Price, Quality, and Capacity: An Application to Supermarket Operations

This paper focuses on a service provider who, faced with competition, must determine the optimal price and level of service quality to provide in order to maximize profits. Service quality and price are assumed to impact jointly on demand for services. Both demand and service quality impact on the cost of providing service. While a considerable literature exists on the impact of service quality on demand or cost, less work has focused on the explicit impact of service quality jointly on both demand for and the cost of providing services. A service quality constraint is appended to the formulation in order to guarantee that a declared service standard is met. Conditions are developed which characterize optimal solutions, together with comparative statics. Illustrative results are presented based on empirical data obtained from a supermarket study.     

Enlisting excel--again

In Volume 26, Number 2, we reported on a group case study runfor level 3 mathematics students at the University of Brighton.At the core of the study was a quadratic assignment problem,and we reported on attempts by students to use Excel to solvethe problem, and on the attendant difficulties. We providedan elegant solution. In this article, we report on another interestingcase study, this time developed for level 2 mathematics students.Again Excel is used to achieve a solution. We report on ourefforts—and on how student answers led to improvements.     

对工科高等数学的研究性教学的一些认识

当前"研究性教学"是比较提倡的教学方式,它有利于培养学生的数学思想和数学素养.为了更好地进行"研究性教学",教师应研究数学史培养学生数学思想,应研究数学教学的认知规律培养学生"研究性学习"习惯,以及进行应用数学知识能力的研究,完美的逻辑体系与学生接受能力的研究,支持这种教学方式的考核方式的研究.     

Linear Programming Applications on Microcomputers

Linear programming is normally thought of as an application to be run on large computers, and for many problems that is the case. However, there are many problems of a suitable size to run on microcomputers, and a variety of packages have appeared on the market in the last year or two claiming to solve linear programming problems on popular microcomputers. The paper considers the features to look for in a package and the type of problem to consider for solution on microcomputers.     

Ricci Curvature and Bochner Formulas for Martingales

We generalize the classical Bochner formula for the heat flow on M to martingales on the path space PM and develop a formalism to compute evolution equations for martingales on path space. We see that our Bochner formula on PM is related to two‐sided bounds on Ricci curvature in much the same manner that the classical Bochner formula on M is related to lower bounds on Ricci curvature. Using this formalism, we obtain new characterizations of bounded Ricci curvature, new gradient estimates for martingales on path space, new Hessian estimates for martingales on path space, and streamlined proofs of the previous characterizations of bounded Ricci curvature.© 2018 Wiley Periodicals, Inc.     

Mesh-dependent stability for finite element approximations of parabolic equations with mass lumping

In this paper, based on some mesh-dependent estimates on the extreme eigenvalues of a general finite element system defined on a simplicial mesh, novel and sharp bounds on the permissible time step size are derived for the mass lumping finite element approximations of parabolic equations. The bounds are dependent not only on the mesh size but also on the mesh shape. These results provide guidance to the stability of numerical solutions of parabolic problems in relation to the unstructured geometric meshing. Numerical experiments on both uniform meshes and adaptive meshes are presented to validate the theoretical analysis.     

The evolution of convention: Conformity and innovation in task-oriented networks

The individual choice between conformity and innovation within task-oriented collectivities is presented as a social dilemma. Adaptive, network-embedded actors are seen to modify their propensities to conform or innovate retrospectively, based on performance differences between the individual and task group levels. A computational framework, based on simulation techniques and algorithmic complexity theory, is advanced to investigate the impact of antecedent structural conditions on innovative behavior and the effect that such behavior has on the evolution of patterns of interaction (conventions) and efficiency. Findings indicate that the dynamics of innovation differ dramatically based on the complexity of tasks faced by actors. When simple tasks are addressed, innovative behaviors have a destabilizing effect on social conventions and are clearly linked to contextual factors. When complex tasks are involved, commitment to innovation may actually help reinforce conventions and is not tied to structural antecedents.Department of Sociology, Stanford University     

Valuations on Manifolds and Integral Geometry

We construct new operations of pull-back and push-forward on valuations on manifolds with respect to submersions and immersions. A general Radon-type transform on valuations is introduced using these operations and the product on valuations. It is shown that the classical Radon transform on smooth functions, and the well-known Radon transform on constructible functions, with respect to the Euler characteristic, are special cases of this new Radon transform. An inversion formula for the Radon transform on valuations has been proven in a specific case of real projective spaces. Relations of these operations to yet another classical type of integral geometry, Crofton and kinematic formulas, are indicated.     

Undertaking data analysis of student outcomes as professional development for teachers

The study reports on collaborations with practitioners to examine the results of students’ performances on high stakes tests as a means to strengthen practitioners’ knowledge of probability and statistics and to empower their conduct of investigations on student performance. Four issues are summarized: the development of their statistical reasoning, their understanding of the meaning of and relationships among the concepts of validity, reliability and fairness as applied to testing, their introduction to the history of testing and its relationship to science, society and cultural inequality, and their reports of independent inquiries. Data on performance on pre- and post-tests demonstrate growth in teacher reasoning and in their professionalism in raising important issues about testing     

基于特征价格模型的滨海公园门票价格影响因素分析——以大连滨海公园为例

本文选取大连市2010~2014年29个滨海公园的季度面板数据,运用特征价格法,实证检验了公园自然属性及园区游憩设施属性与公园门票价格之间的关系。研究发现:在自然属性方面,除温度、降水量和沙滩属性外,其他滨海公园的自然属性均对门票价格具有显著的正向影响;而温度和降水量对游客对公园门票价格的边际意愿支付具有显著的负向影响。比较而言,由于很多滨海旅游景点门票价格实行的一票制,这可能是导致园区内各种游憩设施对门票价格产生较小影响的原因。而一些重要的园区游憩设施仍然会对门票价格产生重要的影响,比如水族馆,海洋动物表演,海上观光游船和潜水等都对门票产生显著的影响;相比之下,那些与滨海资源无关的园区游憩设施属性对门票价格没有影响,甚至产生负向影响。在园区游客拥挤度和景区A级排名方面,二者均会对公园门票价格产生显著影响。基于上述研究结果,本文对滨海公园承载力管理、环境保护、活动设施改善、以及门票价格调整等提出了相关政策建议。     

Mesh-dependent stability for finite element approximations of parabolic equations with mass lumping

In this paper, based on some mesh-dependent estimates on the extreme eigenvalues of a general finite element system defined on a simplicial mesh, novel and sharp bounds on the permissible time step size are derived for the mass lumping finite element approximations of parabolic equations. The bounds are dependent not only on the mesh size but also on the mesh shape. These results provide guidance to the stability of numerical solutions of parabolic problems in relation to the unstructured geometric meshing. Numerical experiments on both uniform meshes and adaptive meshes are presented to validate the theoretical analysis.     

A new class of operators and a description of adjoints of composition operators

Starting with a general formula, precise but difficult to use, for the adjoint of a composition operator on a functional Hilbert space, we compute an explicit formula on the classical Hardy Hilbert space for the adjoint of a composition operator with rational symbol. To provide a foundation for this formula, we study an extension to the definitions of composition, weighted composition, and Toeplitz operators to include symbols that are multiple-valued functions. These definitions can be made on any Banach space of analytic functions on a plane domain, but in this work, our attention is focused on the basic properties needed for the application to operators on the standard Hardy and Bergman Hilbert spaces on the unit disk.     

基于和积和最大积的信念传播算法的收敛性分析

在介绍马尔可夫网络和标准信念传播(Belief Propagation,BP)算法的基础上,以具有4个隐含结点的无环马尔可夫网络为例,详细分析了基于和积和最大积的BP算法收敛性,结果表明,在网络为无环马尔可夫网络时,基于和积的BP算法收敛于全局最优解,而基于最大积的BP算法在任何初值条件下,只要经过有限次迭代,BP算法必收敛到唯一固定点,若算法有唯一最优点,则此固定点为最优点.以实证分析为工具,研究BP算法收敛性,可作为BP算法基础理论研究的一次有益尝试.     

The solution of large-scale least-squares problems on supercomputers

We discuss methods for solving medium to large-scale sparse least-squares problems on supercomputers, illustrating our remarks by experiments on the CRAY-2 supercomputer at Harwell. The method we are primarily concerned with is an augmented system approach which has the merit of both robustness and accuracy, in addition to a kernel operation that is just the solution of a symmetric indefinite system. We consider extensions to handle weighted and constrained problems, and include experiments on systems similar to those arising in the Karmarkar algorithm for linear programming. We indicate how recent improvements to the kernel software could greatly improve the performance of the least-squares code.This paper is based on an invited talk by the author at a Workshop on Supercomputers and Large-Scale Optimization held at the Minnesota Supercomputing Center on 16th to 18th May, 1988.     

纯正半群上的同余扩张(一)

刻划半群上的同余及其扩张是半群的代数理论中的一个非常重要的课题．本文讨论了带上的同余的正规性和不变性以及在其Ｈａｌｌ半群上的扩张，从同余扩张的角度刻划了带上的同余的性质，给出了扩张的极大、极小同余的描述．     

The mathematics of Ponzi schemes

A first order linear differential equation is used to describe the dynamics of an investment fund that promises more than it can deliver, also known as a Ponzi scheme. The model is based on a promised, unrealistic interest rate; on the actual, realized nominal interest rate; on the rate at which new deposits are accumulated and on the withdrawal rate. Conditions on these parameters are given for the fund to be solvent or to collapse. The model is fitted to data available on Charles Ponzi’s 1920 eponymous scheme and illustrated with a philanthropic version of the scheme.     

Bivariate step processes and random evolutions

A random evolution process constructed from regular step processes with a common state space and indexed on an evolution rule space is shown to be a regular step process on the product space. Conversely, it is shown that under mild conditions, any regular step process on a product space is equivalent to a random evolution process. Conditions are given on the cardinality of the spaces and on the parameters of the process that are sufficient for the process to have various recurrence and ergodicity properties. Applications to birth-death processes are given.     

Modelling transport in disordered media via diffusion on fractals

When viewed at an appropriate scale, a disordered medium can behave as if it is strictly less than three-dimensional. As fractals typically have noninteger dimensions, they are natural models for disordered media, and diffusion on fractals can be used to model transport in disordered media. In particular, such diffusion processes can be used to obtain bounds on the fundemantal solution to the heat equation on a fractal. In this paper, we review the work in this area and describe how bounds on branching processes lead to bounds on heat kernels.     

A mixed integer nonlinear optimization model for gas sale company

In this paper the authors propose an optimisation model, called OMoGaS (Optimisation Modelling for Gas Seller), to assist companies dealing with gas retail commercialisation. The model takes into account the limits on price imposed by law on small consumers as well as the gas company policies in order to explore the commercial consequences of different policies. The GAMS framework is used for the optimisation of the defined MINLP model where the profit function is based on the number of contracts with the final consumers, on the tipology of consumers and on the cost supported to meet the final demand while the constraints include information on a maximum daily gas consumption, on yearly maximum and minimum comsumption in order to avoid penalties and on consumption profiles. A case study is presented.