动态更新决策理论、模型、算法及应用

物流动态更新决策理论已经有近百年的历史,它既是现代物流管理的核心,又是管理科学的起源,经过多年的补充、衍变、提高和完善,更新决策理论已经成为管理科学—运筹学应用的典范。追溯不同的经典管理理念,不同的更新决策模型都殊途同归地获得了经济订货量公式EOQ,展现了EOQ所特有的"原始之美"。而由于制造、市场、财务和运营之间的管理冲突,又产生了成本中心说、利润中心说、商物分离说和服务中心说四大物流管理学说,显露出"混沌之美"。在需求呈现出线性变化和二次非线性变化的条件下,可以给出具有"和谐之美"的统一方程和解析算法,对应上述决策原则的著名算法PPT、Silver Meal、LUC和Ritchie均为其特例。在复杂的、动态的、非线性的需求情况下,杨氏方程提出了具有"统一之美"的数学结构,构造出了具有普适性的解析算法,这是对管理科学之科学统一性的诠注。     

变系数变时滞中立型泛函微分方程的振动准则

通过一种直接的方法研究了具有变系数变时滞的超前型一阶中立型泛函方程解的振动性，获得了一系列新的振动准则，改进了许多已知的结果     

‘Wallbanking’, innovativeness and computer attitudes: 25–40-year-old ATM-users on the spot

Attitudes towards ‘wallbanking’ (making use of banking services through an Automated Teller Machine (ATM)) and self-reported frequency of wallbanking have been related to attitudes towards innovations and towards computers. The investigation also included the perception of advantages as well as disadvantages of wallbanking, factors that determine one's choice of a bank, man-machine problems related to the use of an ATM, and demographic factors. Using a sample of 201 respondents in the age range of 25 to 40 years, structural equation modeling revealed that wallbanking attitudes have a major influence on the frequency of using ATMs. The innovativeness attitude ‘New is wasteful’ also showed a clear negative link with the frequency of wallbanking. On the other hand, the relationship between computer attitudes and the frequency of using ATMs had to be rejected. Income and education proved to have an indirect link with the frequency of wallbanking, which refines other research findings. These results may reflect specific financial management characteristics of the age group under investigation.     

Are there causal relationships between the dimensions of the Maslach Burnout Inventory? A review and two longitudinal tests

Arising from interest concerning the possibility of causal relationships among the three components of the Maslach Burnout Inventory, several process models have been proposed for the development of burnout. The present paper first reviews the evidence in favour of the three most influential of these (Leiter and Maslach's model (1988); Golembiewski, Boudreau, Munzenrider, & Luo's (1996) phase model; and Lee and Ashforth's model (1993)). These three models, and our own model (which integrates of two of them, and includes feedback effects of depersonalization on emotional exhaustion) are then compared with each other using structural equation modelling, drawing on longitudinal data from two Dutch samples (total N=1185). The review revealed that none of the seven previous studies on this issue provided any convincing support for any particular causal order proposed so far. In contrast, our own study showed that high levels of exhaustion were associated with high levels of depersonalization over time across both samples. Further, higher levels of depersonalization led to higher levels of emotional exhaustion and lower levels of personal accomplishment. To our knowledge, the present research is the first to provide reliable longitudinal evidence for the conceptualization of burnout as a developmental process, although the effects are not large enough to be of practical use in the recognition of burnout.     

Lower Bounds on Approximation Errors to Numerical Solutions of Dynamic Economic Models

We propose a novel methodology for evaluating the accuracy of numerical solutions to dynamic economic models. It consists in constructing a lower bound on the size of approximation errors. A small lower bound on errors is a necessary condition for accuracy: If a lower error bound is unacceptably large, then the actual approximation errors are even larger, and hence, the approximation is inaccurate. Our lower‐bound error analysis is complementary to the conventional upper‐error (worst‐case) bound analysis, which provides a sufficient condition for accuracy. As an illustration of our methodology, we assess approximation in the first‐ and second‐order perturbation solutions for two stylized models: a neoclassical growth model and a new Keynesian model. The errors are small for the former model but unacceptably large for the latter model under some empirically relevant parameterizations.     

关于矩阵方程的初值问题的一个事实的证明

本文证明了一阶齐次线性方程满足初值条件的特解的形式,可以在矩阵方程dx/dt=A(t)X的初值问题上获得推广,如果A(t)B(t)=B(t)A(t),其中B(t)=integral from n=1 to 1 A(s)ds。     

一级系列复杂反应的行列式解法

本文运用行列式法通过也纳、举例对化学动力学中的对峙、平行、连串等一级系列复杂反应的动力学方程进行求解．     

一类非线性中立型偏微分方程的振动性

本文研究了一类非线性中立型偏微分方程解的振动性,其中(x,t)∈Ω×(0,+∞)≡G,Ω R~n是有界域,Ω逐片光滑,△u=(x,t),且获得了方程(1)在不同边界条件下的所有解振动的充分条件,并给出这些充分条件应用的实际例子     

真空微电子微三极管特性的计算机模拟

用计算机模拟方法研究了真空微电子场致发射微三极管的特性，建立了数理模型。用差分方法求解泊松方程，以福勒──诺德海姆理论处理场致发射特性。细致处理了阴极表面电场，考虑了空间电荷效应的影响，并对模拟结果进行了分析讨论。     

The random robin problem for laplace's equation

A random generalized solution to the Robin problem for Laplace's equation is defined in terms of the sections of the random boundary data. Existence, uniqueness, and properties are established for such a solution. Particularizations to the Dirichlet and Newmann problems as well as generalization to the Robin-Poisson problem are mentioned. Applications of the results are provided.