关于数论函数方程δ（x^2＋y）＋δ（x＋y^2）=2ψ（x^3＋y^3）

对于正整数k，设δ（k）和ψ（k）分别是k的约数和函数和Dedekind函数．该文证明了：方程仅有正整数解（x,y）=（1，1）．     

浅谈矩阵特征值的估计

矩阵的特征值问题是矩阵计算的一个重要方向,在众多的领域中都得到了应用。在这样的大背景下,有必要深入地研究矩阵的特征值的估计问题。基于此,本文将结合国内外对于矩阵的特征值的估计方面的研究,以及一些具体的应用实例,来深入地探索矩阵的特征值的估计问题。     

Generic Processes in Aligning the Multiple Bases of Identity: The Case of Becoming a Ministry Student

Identity theory distinguishes three bases of identity—role, group, and person—but studies have typically focused on one identity at a time. The interrelationship among the multiple bases of identity remains understudied. This study examines the multiple bases of identity individuals engage on their way to becoming ministry students. The results reveal the advantage of examining the multiple bases of identity as subcultural processes, the utility of qualitative research for expanding the empirical scope of identity theory, and the possibility of employing structural symbolic interactionist concepts within a processual symbolic interactionist agenda.     

Effects of key enabling technologies for seru production on sustainable performance

Demand uncertainty, economic globalization, and environmental deterioration force factories to innovate their manufacturing systems for achieving sustainable performance. Seru production, which is the latest manufacturing mode developed in Japan, attracts broad attention from both academia and practitioners. The overwhelming majority of existing works on seru production focus on economic performance unilaterally, while neglecting the environmental and social performance. This paper investigates the effects of key enabling technologies for seru production on sustainable performance. Firstly, four key enabling technologies for seru production are identified through systematic review, and an evaluation indicator system of sustainable performance in the context of seru production is developed. Then, the hypotheses about the effects of the identified key enabling technologies for seru production on sustainable performance are proposed on the basis of previous research achievements, theoretical analysis, and practical observations. Finally, the hypotheses are tested through structural equation modeling. Except for two hypotheses which are not supported and one which is indirectly supported, all other hypotheses are verified. The research results show that the four key enabling technologies for seru production have different effects on the three dimensions of sustainable performance. The achievements of this work are of significance to improve the comprehensive understanding of seru production, as well as to develop practical methods to implement sustainable operations.     

Threshold Estimation for Stochastic Processes with Small Noise

Consider a process satisfying a stochastic differential equation with unknown drift parameter, and suppose that discrete observations are given. It is known that a simple least squares estimator (LSE) can be consistent but numerically unstable in the sense of large standard deviations under finite samples when the noise process has jumps. We propose a filter to cut large shocks from data and construct the same LSE from data selected by the filter. The proposed estimator can be asymptotically equivalent to the usual LSE, whose asymptotic distribution strongly depends on the noise process. However, in numerical study, it looked asymptotically normal in an example where filter was chosen suitably, and the noise was a Lévy process. We will try to justify this phenomenon mathematically, under certain restricted assumptions.     

On pseudo-values for regression analysis in competing risks models

For regression on state and transition probabilities in multi-state models Andersen et al. (Biometrika 90:15–27, 2003) propose a technique based on jackknife pseudo-values. In this article we analyze the pseudo-values suggested for competing risks models and prove some conjectures regarding their asymptotics (Klein and Andersen, Biometrics 61:223–229, 2005). The key is a second order von Mises expansion of the Aalen-Johansen estimator which yields an appropriate representation of the pseudo-values. The method is illustrated with data from a clinical study on total joint replacement. In the application we consider for comparison the estimates obtained with the Fine and Gray approach (J Am Stat Assoc 94:496–509, 1999) and also time-dependent solutions of pseudo-value regression equations.     

Faking it: Personality and individual difference predictors of willingness to buy counterfeit goods

Counterfeiting is now widely regarded as a serious social, economic, and political issue. This study examined demographic, personality, and individual difference predictors of willingness to buy counterfeit goods (WBCG) in a community sample of British adults. Two-hundred and thirty-seven participants completed a questionnaire that assessed their willingness to buy 19 types of counterfeit goods, attitudes towards counterfeiting, material values, Big Five personality traits, and demographics. Structural equation modelling showed that attitudes towards counterfeiting were the strongest predictors of WBCG. In addition, material values predicted both WBCG directly and indirectly through attitudes towards counterfeiting. Older participants showed lower WBCG, although this effect was moderated by participants’ conscientiousness, material values, and attitudes towards counterfeiting. There were no sex differences in WBCG once participants’ age and conscientiousness had been taken into account. These results are discussed in relation to the extant literature on the profiles of consumers who buy counterfeit products.     

Estimation of odds ratios under order restrictions

A new method for estimating a set of odds ratios under an order restriction based on estimating equations is proposed. The method is applied to those of the conditional maximum likelihood estimators and the Mantel-Haenszel estimators. The estimators derived from the conditional likelihood estimating equations are shown to maximize the conditional likelihoods. It is also seen that the restricted estimators converge almost surely to the respective odds ratios when the respective sample sizes become large regularly. The restricted estimators are compared with the unrestricted maximum likelihood estimators by a Monte Carlo simulation. The simulation studies show that the restricted estimates improve the mean squared errors remarkably, while the Mantel-Haenszel type estimates are competitive with the conditional maximum likelihood estimates, being slightly worse.     

高校毕业生择业观对就业的影响分析

择业观是影响高校毕业生就业的一个重要因素，高校毕业生在就业过程中的“择业观”与他们最终的就业有着密切的联系。通过对2008届高校毕业生的择业心态问卷结果进行研究，并与他们最终的就业情况进行比较分析，总结出影响高校毕业生就业的几个最主要的择业观念，从而引导和帮助高校毕业生树立正确的择业观念。     

An additive subdistribution hazard model for competing risks data

The cumulative incidence function plays an important role in assessing its treatment and covariate effects with competing risks data. In this article, we consider an additive hazard model allowing the time-varying covariate effects for the subdistribution and propose the weighted estimating equation under the covariate-dependent censoring by fitting the Cox-type hazard model for the censoring distribution. When there exists some association between the censoring time and the covariates, the proposed coefficients’ estimations are unbiased and the large-sample properties are established. The finite-sample properties of the proposed estimators are examined in the simulation study. The proposed Cox-weighted method is applied to a competing risks dataset from a Hodgkin's disease study.