分段函数在高等数学中作为反例的应用

深入理解数学概念是学好高等数学的基础。文中利用分段函数作为反例诠释高等数学中易混淆的几个概念,使抽象的数学概念更具体。构造分段函数作为反例有助于培养学生的思维能力和创新能力。     

计算机网络技术的原理及发展趋势

计算机网络技术作为信息时代的产物,它是IT技术与通信技术相互结合后的产物。计算机网络自产生之日起就对人类社会的变革产生了巨大的影响。本文介绍了计算机网络基本原理及其发展趋势,并以此为出发点进行了较为深入的讨论。     

Estimation of productivity and markups with price dispersion: Evidence from Chinese manufacturing during economic transition

We estimate firm productivity and markups in the presence of heterogeneous output and input prices. We assume that firms are monopolistically competitive in the output market and that state firms are favored and pay lower prices for inputs due to political connections. The proxy-variable (or called the control-function-based) approach of structurally identifying production functions and productivity is customized to our new setting. Our approach solves the underidentification problem inherent in the standard proxy-variable method. We investigate the Chinese transportation equipment industry and find evidence against perfect competition and price homogeneity. We also find that productivity and markup differentials and dynamics are consistent with the market-oriented reforms in China.     

The effects of mentoring on role stress,job attitude,and turnover intention in the hotel industry

In response to a dearth of mentoring studies in the hospitality literature, this study develops and tests a research model to investigate the influence of mentoring functions on role stress, job attitude, and turnover intention in the hotel industry. The data were collected from employees who had experienced mentoring programs at super-deluxe hotels in South Korea. This study conceptualized mentoring activity as having three main functions, including career development, psychosocial support, and role modeling. Structural equation model (SEM) analyses were used to explore the statistical significance of the paths between these functions and the main outcome variables. The psychosocial support function showed a significant relationship with all variables in the model (i.e., a positive effect on job satisfaction and organizational commitment, but a negative effect on role conflict, role ambiguity, and turnover intention). The relationships were not significant between the career development function and role ambiguity, between role modeling and role ambiguity, or between role ambiguity and turnover intention. The results will enable a better understanding of the effects of hotel mentoring programs and indicate directions for improving their outcomes. The findings can help hotel managers in developing more effective mentoring programs.     

超微粉碎山楂粉营养面包制作工艺研究

探讨以山楂超微粉为原料生产面包的制作工艺,通过正交试验确定了山楂超微粉面包的最佳配方:300目山楂粉添加量为3%、食盐为0.6%、白砂糖为18%、面包改良剂为0.5%,研制的面包不仅风味口感俱佳,且营养价值较高。     

区域物流网络结构及其功能探讨

在现代的区域经济迅速发展中,区域物流网络系统在区域经济中发挥着越来越重要的作用,而对在区域物流网络系统中发挥主导作用的区域物流网络结构的认识仍不充分、全面,缺乏一个系统的梳理,因此,文中在收集的调查信息的基础上,根据物流原理、网络工程理论、区域经济学原理对区域物流网络结构系统分析,深入探究其结构原理及功能。文中认为,区域物流网络结构能够在时间与空间上有效的节省交易的成本,优化整个区域网络系统能够促进经济的规模化发展和经济点的聚集,从而带动经济点的周边经济快速发展。     

企业加速器的功能定位——基于美国IBA、SPARK BA、HTC等10个企业加速器的实证分析

企业加速器是企业孵化器的高级形态,是国家创新体系的重要组成部分。通过对美国IBA、SPARKBA、HTC等10个企业加速器的分析,探索企业加速器功能定位的理论依据,归纳总结出企业加速器的基本功能和衍生功能,探讨对中国企业加速器建设的启示。     

On Mixed and Compound Mixed Poisson Distributions

Recursive formulae are derived for the evaluation of the t-th order cumulative distribution function and the t-th order tail probability of compound mixed Poisson distributions in the case where the derivative of the logarithm of the mixing density can be written as a ratio of polynomials. Also, some general results are derived for the evaluation of the t-th order moments of stop-loss transforms. The recursions can be applied for the exact evaluation of the probability function, distribution function, tail probability and stop-loss premium of compound mixed Poisson distributions and the corresponding mixed Poisson distributions. Several examples are also presented.     

The demand functions that satisfy the weak axiom of revealed preference and generalized monotonicity

We prove that the individual demand function satisfying the Weak Axiom of Revealed Preference and the excess demand function satisfying the Wald’s Axiom are pseudomonotone_*⁺, a new class of generalized monotonicity. With this new concept, we refine the characterization of Zhou for the individual demand function. In particular, a full characterization for the excess demand functions satisfying the Wald’s Axiom is derived.