An upper bound on the minimal total cost of the transportation problem with varying demands and supplies

In general cases, to find the exact upper bound on the minimal total cost of the transportation problem with varying demands and supplies is an NP-hard problem. In literature, there are only two approaches with several shortcomings to solve the problem. In this paper, the problem is formulated as a bi-level programming model, and proven to be solvable in a polynomial time if the sum of the lower bounds for all the supplies is no less than the sum of the upper bounds for all the demands; and a heuristic algorithm named TPVDS-A based on genetic algorithm is developed as an efficient and robust solution method of the model. Computational experiments on benchmark and new randomly generated instances show that the TPVDS-A algorithm outperforms the two existing approaches.     

Stochastic correlation coefficient ensembles for variable selection

In this paper, we propose a novel Max-Relevance and Min-Common-Redundancy criterion for variable selection in linear models. Considering that the ensemble approach for variable selection has been proven to be quite effective in linear regression models, we construct a variable selection ensemble (VSE) by combining the presented stochastic correlation coefficient algorithm with a stochastic stepwise algorithm. We conduct extensive experimental comparison of our algorithm and other methods using two simulation studies and four real-life data sets. The results confirm that the proposed VSE leads to promising improvement on variable selection and regression accuracy.     

Integrated Burgers方程的三阶对称循环算子

利用线性化方法确定了 Integrated Burgers方程的三阶对称循环算子的一般形式 .为产生线性偏微分方程 (组 )更多的对称给出了具有参考价值的理论与实算结果 .且所采用的方法具有普遍性 .     

Optimal distribution-free confidence bands for a distribution function

Distribution-free confidence bands for a distribution function are typically obtained by inverting a distribution-free hypothesis test. We propose an alternate strategy in which the upper and lower bounds of the confidence band are chosen to minimize a narrowness criterion. We derive necessary and sufficient conditions for optimality with respect to such a criterion, and we use these conditions to construct an algorithm for finding optimal bands. We also derive uniqueness results, with the Brunn–Minkowski Inequality from the theory of convex bodies playing a key role in this work. We illustrate the optimal confidence bands using some galaxy velocity data, and we also show that the optimal bands compare favorably to other bands both in terms of power and in terms of area enclosed.     

Some remarks on the duality of continuous time markov chains

A simple proof of Siegmund's result on the relation between dual q-matrices and dual transition functions for Markov chains is given. A byproduct is a uniqueness result for minimal solutions of stochastically monotone q-matrices.     

基准收益率与经济增长的关系依存度研究

基准收益率是厂商投资所要求的回报率,是衡量投资项目在财务上是否达到要求的一个主要标准。在不存在制度性障碍和充分的市场竞争的条件下,根据均衡市场的思想,从理论上导出了基准收益率与经济增长正相关的结论,为基准收益率与经济增长的依附性提供理论基础。     

Protecting the ageing poor or strengthening the market economy: the case of the Hong Kong Mandatory Provident Fund

The Mandatory Provident Fund (MPF) launched by the Hong Kong government seems to be a residual welfare state's strategy to cope with an ageing population and, at the same time, preserve a minimal welfare state and further enhance economic development. The MPF can only provide limited protection for a limited number of employees; many older people still have to depend on financial support from their families or have to work. On the other hand, the MPF immediately boosts the economy by creating more jobs for the financial services sector and by providing more business opportunities for banks and insurance companies. Thus, the MPF has consolidated the foundation of Hong Kong's capitalism by socialising and incorporating the whole working population in the market economy but has provided little protection for their old age.     

数论函数f(n)=n+[k/n]的最小值和最小值点

以[x]表不小于x的最小整数,设函数f(n)=n+[k/n],其中k为给定正整数,自变量n在正整数集取值。本文指出函数f(n)在整个定义域上的最小值和全部最小值点。     

凸连续泛函极小点的一个等价条件

本文利用允许方向锥讨论了凸连续函数在凸集上的极小点的充分必要条件，其主要结果是定理2。     

Repeated measurements designs with unequal period sizes

Summary This paper is concerned with the designs in which each experimental unit is assigned more than once to a treatment, either different or identical. An easy method of constructing balanced minimal repeated measurements designs with unequal period sizes is presented whenever the number of periods is less than the number of treatments. Strongly balanced minimal repeated measurements designs with unequal period sizes are also constructed whenever the number of periods is less than the number of treatments.