Multiple generation product life cycle predictions using a novel two-stage fuzzy piecewise regression analysis method

Product life cycle (PLC) prediction plays a crucial role in strategic planning and policy definition for high-technology products. Forecast methodologies which can predict PLCs accurately can help to achieve successful strategic decision-making, forecasting, and foresight activities in high-technology firms, research institutes, governments, and universities. Over the past few decades, even though analytic framework strategies have been proposed for production, marketing, R&D (research and development), and finance, aiming at each stage of PLCs, forecast methodologies with which to predict PLCs are few. The purpose of this research is to develop a novel forecast methodology to allow for predictions of product life time (PLT) and the annual shipment of products during the entire PLC of multiple generation products. A novel two-stage fuzzy piecewise regression analysis method is proposed in this paper. In the first stage, the product life-time of the specific generation to be analyzed will be predicted by the fuzzy piecewise regression line that is derived based upon the product life-time of earlier generations. In the second stage of the forecast methodology, the annual shipment of products of the specified generation will be predicted by deriving annual fuzzy regression lines for each generation, based upon the historical data on the earlier generations' products. An empirical study predicting the life-time and the annual shipment of the 16 Mb (Mega bit) DRAM (Dynamic Random Access Memory) PLC is illustrated to validate the analytical process. The results demonstrate that two-stage fuzzy piecewise regression analysis can predict multiple generation PLT and PLC precisely, thereby serving as a foundation for future strategic planning, policy definitions and foresights.     

经济学不是数学

对经济学的不加限制的“数学化”可能正在阉割经济学的本质。只要人类的思想、情感、行为还不能“精确”为一组数字，那么经济学就只能是一门关于“人”的科学，而不是一门关于“数字”的科学，经济学和数学就始终存在着一个不可逾越的界限。经济学的根本方法并不是数学，而是唯物辩证法。数学只是经济学的分析工具。远离了人文精神，抛弃了唯物辩证法，经济学就只剩下了一堆数字、图表、模型，经济学中的主体——人就被消解了。     

基于层次分析法的建设项目质量等级评定

从引入建设项目质量概念开始,构造了一个实用的、有良好操作性的三级递阶层次结构进行建设项目质量的定量评判,并且引入改进了的权重计算方法。     

Nash-equilibria in a heterogeneous oligopoly with fuzzy information

We consider a model of an oligopolistic market with heterogeneous firms and products where neither the cost nor the demand functions are common knowledge. Instead, each firm only has some vague ideas about the price strategies adopted by its competitors which is modelled by a fuzzy set. In analogy to the notion of an "equilibrium of actions and beliefs" we define and characterize a generalized Nash-equilibrium and show its existence under general conditions. Furthermore, the impact of the fuzzy information on the equilibrium outcome is analyzed by means of a comparative static analysis within a particular model framework.Received: 28 May 2002, Accepted: 25 December 2002, JEL Classification: D43, D80, L13We wish to thank Bernhard F. Arnold, the editor Murat Sertel , and two anonymous referees for helpful comments. Of course, we are responsible for all remaining errors.     

中小企业供应链合作伙伴选择研究

根据中小企业的特点,提出中小企业在选择供应链合作伙伴时,首先需要选择目标产业,然后在目标产业中选择具体企业作为供应链合作伙伴。分别采用了模糊评价法和层次分析法评价目标产业和选择合作伙伴。     

基于建构主义的高职微积分教学方法探讨

微积分是高职院校一门非常重要的基础课程,是学生学习专业课程的基础和工具。传统的微积分教学基本上是传授型,重理论轻应用,忽视概念产生的实际背景和方法的实际应用,学生学起来感到困难,学了不知道如何用于解决实际问题。该从微积分的内容、教材的编写、教师的教学、学生的学习态度与方法四个方面分析了当前微积分教学中存在的问题,提出以建构主义学习理论为指导对微积分的教学进行改革,对从微积分发展史出发建构教学内容、以问题为中心组织教学、利用计算机进行微积分概念的辅助教学、注重数学建模能力的培养等教学方法进行了探讨。     

模糊综合评判在ERP实施时机决策中的应用

文章研究了利用模糊数学方法,将模糊综合评判理论应用于对ERP实施时机决策,建立影响ERP实施的因素体系,构造隶属函数建立数学模型,通过数据处理与分析确定最佳ERP实施时机,克服了传统决策方法的种种弊端,对于ERP的实施时机决策提供了一条新的可行途径。     

基于粒子群优化的模糊聚类分析

基于求解实优化问题时,粒子群优化算法优于遗传算法。在基于遗传算法的模糊C均值聚类算法基础上,给出了基于粒子群的模糊C均值聚类算法,试验结果表明:该算法克服了传统的模糊C均值聚类算法的缺陷,同时在收敛速度方面明显优于基于遗传算法的模糊C均值聚类算法。     

既有结构可靠度的模糊算法

基于结构抗力和荷载效应的不确定性，提出了一种既有结构工程可靠度的模糊算法。该方法利用模糊算法可以反映客观事物因素的层次性，又便于比较和考虑各层次中诸因素作用的大小以决定可靠度。算例结果表明该方法简单实用，其模型可以很好地拟合真实的极限状态函数，是解决既有结构体系可靠度问题的有效方法。