Very long-term retention of the control of variables strategy following a brief intervention

Middle school students (n = 354) were tested for their understanding of the control of variables strategy (CVS) 2.5 years after participating in a study comparing three different interventions for teaching CVS. The key finding was that the pattern of effects observed in the 4^th grade continued to be observed in the 6^th grade. This was because (a) students who had mastered CVS in the 4^th grade were likely to continue to perform at mastery levels in the 6^th grade whereas (b) the learning of students who had not mastered CVS in 4^th grade was independent of the teaching intervention they had received in the 4^th-grade study. These findings demonstrate that a brief intervention of direct instruction in CVS can produce long-lasting learning of the principle of controlling variables.     

Company related variables and their impact on the NPD outcome in the context of international markets in Finnish high-technology companies

While much research has been directed at the variables critical to successful R&D of new products on the one hand and high-technology products on the other, much less work has been directed at those factors crucial to the success of these products when the firm enters the international marketplace. This study surveys Finnish high-technology firms and variables related to the properties of the company and their association with successful versus unsuccessful attempts to enter the international marketplace. Relationship between firm characteristics – type of industry, size of the company, background of key personnel, export intensity and experience in product launches – and success/failure in the product launches is investigated. The generalizability of the findings is also discussed.     

Domain Coloring and the Argument Principle

Abstract

The domain-coloring algorithm allows us to visualize complex-valued functions on the plane in a single image—an alternative to before-and-after mapping diagrams. It helps us see when a function is analytic and aids in understanding contour integrals. The culmination of this article is a visual discovery and subsequent proof of the Argument Principle, which relates the count of poles and zeros of a meromorphic function inside a contour to the accumulated change in argument of the function around the contour. Throughout, I offer connections to standard learning goals of courses in complex variables.     

实验设备管理中几种决策的理论研究

该文章就实验设备维护中怎样配备恰当的维修人数问题,以及如何选择最佳管理模式问题进行了深入的研究,用数学的方法从理论上解决了这些问题。     

Lenguaje y rendimiento escolar: Un estudio predictivo

La incidencia de las competencias lingüistícas del escolar sobre las adquisiciones escolares en las demás áreas del currículum es una realidad que todos los maestros pueden comprobar día a día. En este trabajo se investiga esa incidencia, medida a través de la variable fracaso escolar, y sus resultados podrían permitir extraer algunos principios de intervención educativa precoz en algunos aspectos del lenguaje cruciales para la escolaridad posterior.     

影响知识型员工区域间流动三类要素关系分析

本文的研究目的是了解知识型员工的区域间流动的三类要素的关系,即人口统计变量、价值观和区域性因素偏好的关系。通过对625名知识型员工的问卷调查,获得人口统计变量、价值观和区域性因素的偏好的相关数据,对其进行独立样本T检验、单因素方差分析和相关分析,得出了人口统计变量、价值观和区域性因素偏好部分相关的结论。     

Multi-attribute decision-making approach dealing with uncertain linguistic assessment information

An approach is presented to deal with a multi-attribute decision-making problem in which the attribute weights are unknown and the attribute values take the form of uncertain linguistic variables. First, a linguistic assessment standard is set up to deal with the uncertain linguistic attributes, and the operation laws of uncertain linguistic variables and the uncertain linguistic weighting average(ULWA)operator are introduced. Then a ranking formula of uncertain linguistic variables based on expectation-variance is proposed. As for the case without weight information, a goal program based on a warp function is constructed to determine the attribute weights, and the ULWA operator is utilized to aggregate the assessment information of uncertain linguistic variables, and the corresponding alternatives are ranked by a formula based on expectation-variance. Finally, a numerical example is given, and the results demonstrate that it is much easier and faster for the ranking method based on expectation-variance when compared to the existing methods.     

互斥变量bj图及其应用

在互斥变量K图的基础上提出了逻辑函数的互斥变量bj图，给出了全／部分互斥变量bj图的化简方法及实例．此外，文中还讨论了互斥变量K图与互斥变量bj图的转换方法．     

Using the United States Census Data to Introduce Differential Equations

Abstract

This article describes a method for using the United States Census data to open a differential equations course. The question of finding a model for the United States population data gives students a first experience with creating a model using differential equations, and also understanding derivatives, what they mean, and how to calculate them in the context of real data. This model-building start motivates further exploration in many of the standard differential equations topics: the method of separation of variables, slope fields, autonomous equations, equilibria, and stability.     

三元二次多项式分解的一种方法

利用待定系数法得出了三元二次多项式可进行因式分解的充要条件，并应用这个充要条件解决了两个具体问题。