NP-hardness of linear multiplicative programming and related problems

The linear multiplicative programming problem minimizes a product of two (positive) variables subject to linear inequality constraints. In this paper, we show NP-hardness of linear multiplicative programming problems and related problems.     

马尔可夫模型的市场预测方法及其应用

本文简述了马尔可夫模型的基本原理，介绍了利用马氏过程的基本特征．即其平稳性和无后效性．对随机现象进行统计预测的方法。本文选取市场为研究对象，根据产品的市场占有率的随机变化过程，建立起市场占有率的马尔可夫预测模型，并进行了实例分析。在模型的实际应用时，要注意系统状态转移的平稳性和进行系统状态划分的有效性。     

Generalized (η,ρ)-Invex Functions and Global Semiparametric Sufficient Efficiency Conditions for Multiobjective Fractional Programming Problems Containing Arbitrary Norms

The purpose of this paper is to develop a fairly large number of sets of global semiparametric sufficient efficiency conditions under various generalized (η, ρ)-invexity assumptions for a multiobjective fractional programming problem involving arbitrary norms.     

固相分光反射光度法测定药物中的合成色素

固相分光光度法是一种简单，快速，灵敏的新型痕量的分析方法，本文首次提出用聚酰胺做吸附剂，采用改造的比色皿，测量反射器吸光度的方法，将固相分光光度法的应用由仅能分析痕量的无机离子，推广到测量药物中的合成色素，结果令人满意。     

Black hole greybody factors and absorption of scalars by effective strings

We compute the greybody factors for classical black holes in a domain where two kinds of charges and their anticharges are excited by the extra energy over extremality. We compare the result to the greybody factors expected from an effective string mode] which was earlier shown to give the correct entropy. In the regime where the left- and right-moving temperatures are much smaller than the square root of the effective string tension, we find a non-trivial greybody factor which agrees with the effective string mode]. However, if the temperatures are comparable with the square root of the effective string tension, the greybody factors agree only at the leading order in energy. Nevertheless, there are several interesting relations between the two results, suggesting that a modification of the effective string mode] might lead to better agreement.     

基于差分方程的货运市场占有率模型

合理估计产品的市场占有率是企业做出营销决策时需要考虑的最重要的因素之一。总结国内外部分有关市场占有率的研究献；建立关于铁路、公路货运量在全社会货运中市场占有率的差分方程组模型，运算后得出铁路、公路货运在整个货运市场中的占有率将趋向相对稳定的结论；通过利用历史统计数据计算，验证了该模型的可行性。     

Brent原油期货市场的协整性分析

本文利用单位根检验和协整关系检验验证了Brent原油期货市场的有效范围,发现其在5个月内是有效的。在市场有效范围内,对现货价格和期货价格建立了向量误差修正模型,具有良好的预测效果。同时发现该期货市场某时刻价格的影响可以持续2个月。     

The tolerance approach in multiobjective linear fractional programming

When solving a multiobjective programming problem by the weighted sum approach, weights represent the relative importance associated to the objectives. As these values are usually imprecise, it is important to analyze the sensitivity of the solution under possible deviations on the estimated values. In this sense, the tolerance approach provides a direct measure of how weights may vary simultaneously and independently from their estimated values while still retaining the same efficient solution. This paper provides an explicit expression to the maximum tolerance on weights in a multiobjective linear fractional programming problem when all the denominators are equal. An application is also presented to illustrate how the results may help the decision maker to choose a most satisfactory solution in a production problem.     

关于大经济金融市场

在Aumann大经济框架下，本文给出具有可测空间经纪人的大金融市场模型；讨论了资产结构完全时均衡的存在性；给出了以经纪人代表效用表出形式的金融资产定价公式，它推广[3]中相关内容。模型更贴近于具有对称信息充分竞争的涵义．