Spreadsheet Modeling for the Classroom: The Value of Position on the Web Page

ABSTRACT

This article focuses on the authors' experience with a little-used quality of spreadsheets–the ability to construct spatial models. The article follows the development of a Web page layout model for classroom use. The model presents students with the problem of balancing out value of position, color, movement and other input factors in developing overall Web page strategy.     

煮糖过程建模

对某个系统进行有效的控制，必须要定量、准确地分析该系统的特性，弄清表征该系统特性的各物理量之间的关系，而这种关系的定量表达式，被称为该系统的数学模型。文章运用蔗糖结晶理论，建立了比较合理的数学模型，这种模型建立的要点在于结晶质量的计算。     

数学建模教学改革的探索与实践

传统的教学模式具有较强的封闭性和保守性,忽略了数学思想的建立、数学方法的使用和学习能力的培养。《数学建模》具有难度大、涉及面广、形式灵活等特点,不易于培养学生的自主精神。学生普遍反映概念难懂,习题难做,方法不易掌握,自己建模有难度。虽然这门课程越来越受重视,但在教学中存在着问题。因此,在有限的课时内,如何组织安排好课堂的教学,进行教学方法的改革十分必要,且势在必行。     

The Measurement and Structural Modeling of the Reasonableness of Workplace Accommodations

The Americans with Disabilities Act of 1990 (ADA) guarantees protection from discrimination for persons with a disability. The ADA requires employers to make reasonable accommodations for persons with physical and mental disabilities unless doing so would produce undue hardship on the organization. Fifteen years after the passage of the ADA, the question as to what is a reasonable accommodation remains controversial, especially for some types of disabilities. In this study, a reasonable accommodation scale is proposed and tested using structural equation modeling in hopes that such a scale will aid the courts and organizations in determining what is reasonable. Individuals’ level of awareness of disability issues is also examined in the model to examine the relationship between awareness and willingness to accommodate. Results indicate acceptable fit of the model to the data and provide support for the proposed scale. Furthermore, the relationship between awareness of disability issues and willingness to accommodate was significant. Implications for research and practice are discussed.     

Another strategy to assess sustainable development

The goal of sustainoble development is to preserve sustainabitity trod simultaneously prevent catastrophe in a man-land .system. However, almost all the existing approaches to assessing sustainable development are to measure the sustainability. namely appraise from the obverse side of the sustainable development. So it seems necessary to attack the same task on the reverse, namely to measure the passibility of eatostrophe. In this paper, with a case study of Tianjin, China. we employ catastrophe theory and models to integrate Tianjin＇s sustainable development indicators, and then deduce the catastrophe risk index （ CRI） to present the level of catastrophic possibility in the city. Applying catastrophe theory, is a new strategy to assess sustainable development and shows great practical significance, especially for those developing regions or countries, who always give more priority to their economy and therefore have more obligation to make sure whether their social economic activities might bring forth any ecological environment catastrophe. Besides, being both qualitative and quantitative, the approach could be employed to explore not only static characteristics bat also dynamic mechanism of man-land system. Although our work is only a maiden attempt and still calls for further effort to improve it, the case study of Tianjin in this paper would assure as the great promising future to apply, catastrophe theory to sustoinable devetopment modeling,     

The Role of Retail Competition,Demographics and Account Retail Strategy as Drivers of Promotional Sensitivity

We study the determinants of sensitivity to the promotional activities of temporary price reductions, displays, and feature advertisements. Both the theoretical and empirical literatures on price promotions suggest that retailer competition and the demographic composition of the shopping population should be linked to response to temporary price cuts. However, datasets that span different market areas have not been used to study the role of retail competition in determining price sensitivity. Moreover, little is known about the determinants of display and feature response. Very little attention has been focused on retailer strategic decisions such as price format (EDLP vs. Hi-Lo) or size of stores. We assemble a unique dataset with all U.S. markets and all major retail grocery chains represented in order to investigate the role of retail competition, account retail strategy, and demographics in determining promotional response. Previous work has not simultaneously modeled response to price, display, and feature promotions, which we do in a Bayesian Hierarchical model. We also allow for retailers in the same market to have correlated sales response equations through a variance component specification. Our results indicate that retail strategic variables such as price format are the most important determinants of promotional response, followed by demographic variables. Surprisingly, we find that variables measuring the extent of retail competition are not important in explaining promotional response.     

Linear Correlation and EVT: Properties and Caveats

Due to the current credit crisis, critical questions are beingasked concerning some of the quantitative methods used in riskmanagement under the Basel II proposals. In this paper I havegiven a critical look at Extreme Value Theory and Copulas. Boththeir potential applications and the possible caveats are discussed,and this mainly with the subprime crisis as a background.     

农业经济学的科学进化

以常规科学基本理论的发展为主导,以边际平衡这一理论核心为焦点,探索农业经济学科学化的过程。其中主要涉及生产函数、经营函数、状态分析、行为分析、状态行为分析和随机控制等基本概念。作为学说史,阐述的逻辑主线集中在这些概念的形成及其进展的条件上,目的在于揭示农业经济学理论进化的基本途径。     

河北保定农户居住空间行为选择的动力机制研究

农户对居住空间的行为选择是直接影响乡村空间秩序的重要因素,只有充分认识并准确把握其空间行为选择的现状及存在问题,才能从行为主体空间行为选择上进一步探寻合理引导其空间行为演变的发展道路。为了探讨当前新型城镇化背景下农户居住空间行为的演变规律,研究基于微观视角对保定市不同地区的农户进行了居住空间行为的问卷调查,并对结果进行了统计分析和结构方程模型的构建与检验。实证结果表明:(1)调查区域大部分农户对当前居住空间的满意程度为一般;(2)在农户居住空间满意度方面,配套环境驱动占主要地位,其路径系数高于住房条件驱动;(3)在配套环境驱动方面,经济活动交易便利是最主要因素;在经济生产条件驱动方面,耕种便利因子的影响程度高于灌溉条件。在住房条件驱动方面,各具体测度变量根据影响的主次程度排序依次为:建筑面积、宅基地面积、房屋结构、排水便利、出路与交通。建议保定市从配套设施建设、循序渐进的规范化引导、创新制度体系建设等方面合理引导农户居住空间的行为演变。