一种基于佳点集遗传算法的物流配送网络优化

首先根据实际问题分析了物流配送网络优化模型的各个关键组成部分,包括优化目标、决策变量和约束条件,并针对目前物流配送网络优化算法中存在的一些问题提出了一种新的算法,其核心是佳点集遗传算法。该算法编码采用prufer num ber结构,变异和交叉概率自适应选择。     

品牌进入消费者考虑集的决策规则——基于牙膏产品品牌的实证研究

消费者考虑集是消费者决策过程中的重要阶段，品牌只有进入考虑集才有可能被最终购买。本研究在上海以牙膏作为测试对象检验了牙膏品牌进入考虑集时消费者所依据的决策规则。实证结果显示，消费者主要使用排除式决策规则、非权重的补偿式决策规则和权重的补偿式决策规则。     

Valuation of commodity derivatives in a new multi-factor model

This paper extends existing commodity valuation models to allow for stochastic volatility and simultaneous jumps in the spot price and spot volatility. Closed-form valuation formulas for forwards, futures, futures options, geometric Asian options and commodity-linked bonds are obtained using the Heston (1993) and Bakshi and Madan (2000) methodology. Stochastic volatility and jumps do not affect the futures price at a given point in time. However, numerical examples indicate that they play important roles in pricing options on futures. This revised version was published online in June 2006 with corrections to the Cover Date.     

集值函数及向量值函数的两类线性算子逼近

本文得到了利用插值型线性算子列及积分型算子列逼近连续集值函数及连续向量值函数的收敛逼近阶。     

股票价格均值回归理论研究综述

随机漫步理论认为股票的价格是不能预测的,许多实证检验的结果也支持了这一结论。但是,近年来均值回归理论对随机漫步理论提出了挑战。从长期来看,股票价格呈均值回归是必然的;均值回归具有不对称性;政府行为对股票的均值回归具有一定的影响。     

项目团队成员绩效考评研究

项目团队成员绩效考评是项目人力资源管理的关键环节之一，是整个人力资源管理的基础。科学、公正、合理的绩效考评，对团队成员的激励、薪酬、晋升都具有重要意义。引入模糊综合考评理论，在阶段性考评的基础上着眼于对项目成员进行综合绩效考评，为项目绩效考评对项目团队成员进行绩效考评提供一种思维方式。     

An optimization approach to business buyer choice sets: How many suppliers should be included?

In many new or repeat purchasing situations, business buyers must decide how many suppliers to consider (a “choice set”) in determining which supplier(s) to actually buy from or contract with. This paper develops an optimization approach to determining the size of the choice set, taking into consideration buyer utility and search and evaluation costs. A theoretical model is developed for both one-time and repeat purchase situations. The model is estimated using empirical data received from bids received for procurement auctions. In these auctions, suppliers provide bids for steel pipe based on two product attributes (price and delivery time). Model sensitivity to small changes in parameters is also tested.     

Forecasting U.S. money growth using economic uncertainty measures and regularisation techniques

This paper examines the out-of-sample forecasting properties of six different economic uncertainty variables for the growth of the real M2 and real M4 Divisia money series for the U.S. using monthly data. The core contention is that information on economic uncertainty improves the forecasting accuracy. We estimate vector autoregressive models using the iterated rolling-window forecasting scheme, in combination with modern regularisation techniques from the field of machine learning. Applying the Hansen-Lunde-Nason model confidence set approach under two different loss functions reveals strong evidence that uncertainty variables that are related to financial markets, the state of the macroeconomy or economic policy provide additional informational content when forecasting monetary dynamics. The use of regularisation techniques improves the forecast accuracy substantially.     

人工挖孔桩半桩支护方案可行性分析

本文以实际工程深基坑工程为研究对象,分别对桩基进行数值计算和数值模拟,通过对结果进行对比可以看出,人工挖孔桩采用半桩基是可行的。     

A saddlepoint approximation to the distribution of the sum of independent non‐identically uniform random variables

Calculating the probability of the corresponding significance point is important for finite sample sizes. However, it is difficult to evaluate this probability when the sample sizes are moderate to large. Under these circumstances, consideration of a more accurate approximation for the distribution function is extremely important. Herein, we performed a saddlepoint approximation in the upper tails for the distribution of the sum of independent non‐identically uniform random variables under finite sample sizes. Saddlepoint approximation results were compared with those for a normal approximation. Additionally, the order of errors of the saddlepoint approximation was derived. © 2014 The Authors. Statistica Neerlandica © 2014 VVS.