Regularity in individual shopping trips: implications for duration models in marketing

Most models for purchase-timing behavior of households do not take into account that many households have regular and non-shopping days. We propose a statistical model for purchase timing that exploits information on the shopping days of households. The model is formulated in a counting process framework that counts the recurrent purchases for each household over (calendar) time. In our empirical application of yogurt and detergent purchases from the ERIM1 The data can be found at http://gsbww.uchicago.edu/research/mkt/Databases/ERIM/ERIM.html View all notes database, we show that calendar time effects and regular and non-shopping days are important features to include in models for purchase-timing behavior. We find, for instance, that for these product categories the probability of purchasing is 50–60% higher on Saturdays and 70% higher on regular shopping days. We highlight the managerial implications of these model features by simulating some promotional actions.     

Methods of constructing group divisible designs with k = 3 and 4

The paper provides methods of construction of group divisible designs with block sizes three and four through balanced incomplete block and partially balanced incomplete block designs of block sizes 3 and 4. Furthermore, four non-isomorphic solutions are given.     

违背学术规律 漠视个性与人性——评目前高校流行的“量化”管理制

新时代要求在改善标准化的基础上,更加关注个性化、多元化、人性化的学术管理,克服现行"一刀切"式数字化学术管理机制的弊端,努力建设和谐健康的学术研究新秩序.     

对化学实验教学的思考

本文说明了化学实验的重要作用,分析了实验的特征类型,共六大类,证实了化学实验过程的特殊性,是化学学科的特点和化学教育的基本规律,从重要作用与特征和类型贯彻掌握化学知识才能提高化学教学的质量,有一个条理清析的知识就自然而然地发展了能力的看法,从而达到优质的教学目的。     

L—fuzzy拓扑空间中的S—连通性与极不连通性

本文引入了L—fuzzy S-通空间与L—fuzzy极不通空间的概念,讨论了它们的等价刻划及基本性质,证明了LF拓扑空间的S-通性是LF拓扑性质,LF拓扑空间的极不通性是LF拓扑性质。     

关于Gerber定理的推广及应用

给出了关于n维单形的Gerber定理的推广,建立了关于单形内点一个更强的几何不等式,并给出了它的一个应用.     

宁乡话“起”字研究

宁乡话里的“起”字有多种用法。“起”字可以作语素 ,主要有 4种语素义。可以作动词 ,有 7种义位。可以作量词 ,有 2种义位。还可以作助词 ,有 9种分布