论二十世纪前半叶毛泽东和梁漱溟对农民问题的认识

毛泽东和梁漱溟均把农民问题作为了找寻国家出路过程中的基本问题。毛泽东服从中国革命发展的需要考量农民问题,梁漱溟基于中国社会基础的再造考量农民问题,最后的结果是毛泽东主张的方案取得了成功,而梁漱溟的乡村建设实验却没有什么成效。他们为解决农民问题而进行的努力,虽然结局不同,但他们对农民问题的认知中都内含了革命性和现代性两方面的因素。他们探索的思路和方案都有其内在的合理性,其中梁漱溟的探索尽管就确立建国基础而言是一种理想化的设计,但就其解决农民问题本身而言还是有价值的。今天我们仍然需要从他们的思路中汲取营养,以求有助于解决农民问题。     

硕士研究生问题意识的遗失与回归

环视当下的象牙塔,硕士研究生的问题意识明显缺失,而研究生问题意识的不足是制约其创新能力发展的瓶颈。本文从传统文化背景、师生伦理关系、教育生态环境、人才评价机制和现实生活压力等维度,对其问题意识缺失的原因作了理性分析,进而就研究生创新能力的提升提出建议。     

时滞微分方程边值问题正解的存在性

利用Avery-Peterson不动点定理,讨论了具有p-Laplacian算子时滞微分方程边值问题3个正解的存在性.     

The homotopy perturbation method for the Black–Scholes equation

The homotopy perturbation method is designed to obtain a quick and accurate solution to the Black–Scholes equation and boundary conditions for a European option pricing problem. The problem of pricing a European option can be cast a partial differential equation. The analytical solution of the equation is calculated in the form of a convergent power series with easily computable components.     

A note on estimating the common mean of k normal distributions and the stein problem

An unbiased estimator for the common mean of k normal distributions is suggested. A necessary and sufficient condition for the estimator Lo have a smaller variance than each sample mean is given. In the case of estimating the common mean vector of k p-variate (p ≤ 3) normal distributions a combined unbiased estimator may be used. We give a class of estimators which are better than the combined estimator when the loss is quadratic and the restriction of unbiasedness is removed.     

Exact approaches for the pickup and delivery problem with loading cost

In this paper, we propose a branch-and-cut algorithm and a branch-and-price algorithm to solve the pickup and delivery problem with loading cost (PDPLC), which is a new problem derived from the classic pickup and delivery problem (PDP) by considering the loading cost in the objective function. Applications of the PDPLC arise in healthcare transportation where the objective function is customer-centric or service-based. In the branch-and-price algorithm, we devise an ad hoc label-setting algorithm to solve the pricing problem and employ the bounded bidirectional search strategy to accelerate the label-setting algorithm. The proposed algorithms were tested on a set of instances generated by a common data generator in the literature. The computational results showed that the branch-and-price algorithm outperformed the branch-and-cut algorithm by a large margin, and can solve instances with 40 requests to optimality in a reasonable time frame.     

A note on maximum entropy spectrum estimation

This article studies the maximum entropy spectrum estimation. After a bnei discussion on iiow co select ciic appropriate constraints and tiie objec¬tive functions, we decide to choose the constraints containing only the first four sample moments and, consequently, to employ the second order spectral entropy as the objective function. The resulting (maximum entropy) spectral estimate is the power spectral density of an ARMA sequence. Examples for comparing our proposal with the traditional maximum entropy spectral estimate follow at the end.     

The Exact Likelihood Ratio Test for Equality of Two Normal Populations

Testing the equality of two independent normal populations is a perfect case of the two-sample problem, yet it is not treated in the main text of any textbook or handbook. In this article, we derive the exact distribution of the likelihood ratio test and implement this test with an R function. This article has supplementary materials online.     

The Effects of Background Characteristics of Attorneys and Judges on Decision Making in Domestic Relations Court

The purposes of this research were: (1) to determine whether background characteristics of attorneys and judges affect the awarding of child support orders and (2) to determine whether institution of 1987 Ohio child support guidelines provides predictable and fair child support awards. It was concluded that the two sets of background characteristics had separate effects on the awarding of child support oders. Attorney's background characteristics affected receipt of child support awards. Judges' background characteristics affected amount of child support awards. Institution of the 1987 Ohio child support guidelines did not provide predictable and fair child support awards. Attorneys were found to be reluctant to win child support awards for their clients. Judges with low integrity scores were found to be deviating from the 1987 Ohio child support guidelines.     

IRUSRT: A Novel Imbalanced Learning Technique by Combining Inverse Random Under Sampling and Random Tree

In this article, a novel technique IRUSRT (inverse random under sampling and random tree) by combining inverse random under sampling and random tree is proposed to implement imbalanced learning. The main idea is to severely under sample the majority class thus creating multiple distinct training sets. With each training set, a random tree is trained to separate the minority class from the majority class. By combining these random trees through fusion, a composite classifier is constructed. The experimental analysis on 23 real-world datasets assessed over area under the ROC curve (AUC), F-measure, and G-mean indicates that IRUSRT performs significantly better when compared with many existing class imbalance learning methods.