面向对象软件中类和对象的识别

近年来面向对象程序设计方法逐渐成为软件设计的思想主流。在面向对象程序设计中,往往将系统分解成一系列对象和与对象相关联的类。而类和对象的识别是面向对象程序开发中最重要的一部分,不同的分析员可能采用不同的方法。文章通过实例介绍了两种简单易行的在面向对象程序设计中识别类和对象的方法。     

BIM技术引领下的智能建筑全生命周期探索

当前,BIM技术已经逐渐发展为建筑信息化的根基和核心技术,基于BIM技术可建立建筑物3D模型,并对建筑进行机电初步设计、深化设计(平面管线综合、冲突与检测、虚拟与现实对比)、建筑电气系统设计等。再在理论上利用BIM技术将建筑的信息与运营维护管理结合,集成智能运维网络,加强运营期的综合信息化管理,实现建筑运维系统一体化集成,并撰写事故发生时的相关解决方案书。     

A science need: Designing tasks to engage students in modeling complex data

In this information age, the capacity to perceive structure in data, model that structure, and make decisions regarding its implications is rapidly becoming the most important of the quantitative literacy skills. We build on Kaput’s belief in a Science of Need to motivate and direct the development of tasks and tools for engaging students in reasoning about data. A Science of Need embodies the utility value of mathematics, and engages students in seeing the importance of mathematics in both their current and their future lives. An extended example of the design of tasks that require students to generate, test, and revise models of complex data is used to illustrate the ways in which attention to the contributions of students can aid in the development of both useful and theoretically coherent models of mathematical understanding by researchers. Tools such as Fathom are shown as democratizing agents in making data modeling more expressive and intimate, aiding in the development of deeper and more applicable mathematical understanding.

Weighing Fog: Modeling on Day 1 of Differential Equations

Abstract

The first day of many mathematics classes is filled with the formalities of the syllabus and a lecture introduction to the course content. Here, an alternative is presented where modeling is placed as the centerpiece to orient students to the work of differential equations; namely, to capture as beautifully and compactly as possible through the process of inquiry, conjecture, and experimentation, the deep and interesting aspects of modeling the physical world. A demonstration of the sublimation of dry ice in water serves as the nucleus of the lesson.     

UML在教务管理系统中的应用

提出一种实用的基于UML的需求分析及其建模方法，以概念模型来表达事务模型，以状态图、设计类图及交互图模型表达系统的结构逻辑及行为逻辑，以用况表达系统需求，讨论了需求分析及其建模的过程概念。该方法已经在教务系统需求分析中得到成功应用。     

学习系统的形式化建模研究现状与评析

学习系统的形式化建模目前主要有两种思路:从学习资源的角度建模和结合过程、资源的学习系统建模,对于前者该文介绍了一些国际/国内组织或机构关于学习对象元数据标准的研究成果;对于后者该文重点介绍了ITT(Instruction Transaction Theory)、教育建模语言和IMS学习设计规范的研究思想,对于有关的研究成果该文都做了相应的评述。     

The Determinants of Students' Perceived Learning Outcomes and Satisfaction in University Online Education: An Empirical Investigation*

In this study, structural equation modeling is applied to examine the determinants of students' satisfaction and their perceived learning outcomes in the context of university online courses. Independent variables included in the study are course structure, instructor feedback, self‐motivation, learning style, interaction, and instructor facilitation as potential determinants of online learning. A total of 397 valid unduplicated responses from students who have completed at least one online course at a university in the Midwest were used to examine the structural model. The results indicated that all of the antecedent variables significantly affect students' satisfaction. Of the six antecedent variables hypothesized to affect the perceived learning outcomes, only instructor feedback and learning style are significant. The structural model results also reveal that user satisfaction is a significant predictor of learning outcomes. The findings suggest online education can be a superior mode of instruction if it is targeted to learners with specific learning styles (visual and read/write learning styles) and with timely, meaningful instructor feedback of various types.     

行为建模技术(Behvioral Modeling)在零件设计中的应用

为更好地把握设计意图，在Pro／ENGINEER软件中需要人工创建各种“关系”，这种“关系”只能向前引用“尺寸参数”，如果需要向后引用“尺寸参数”则要应用行为建模技术。行为建模技术通过建立“分析特征”实现优化目标的建立，以尺寸参数或用户自定义参数为变量对优化目标进行优化。本文通过一个轮胎模型，例证了上述方法的应用过程，得出了优化结果。     

A PI controller configuration for robust control of a class of nonlinear systems

The PI control configuration for stabilization and signal tracking of nonlinear systems is investigated. Semiglobal asymptotic stability and semiglobal practical signal tracking of the controlled system are proven using results from the theory of nonlinear singularly perturbed systems.     

数据建模技术在信息系统中的应用

信息管理系统的开发通常遵循分层体系结构,而数据层是多层体系中最为关键和重要的一层。数据建模是对数据进行分析和设计的一种有效手段。利用多年系统开发经验对数据层的开发过程进行总结,归纳出了一套有效的数据层开发框架,并对这个框架的实施步骤进行了描述。通过一个实例来说明如何运用这个框架将数据模型映射为关系数据库和代码,从而实现将3者有机地结合起来,快速地完成代码的编写和单元测试工作。最后对这个框架的适用范围和下一步的研究内容进行了探讨。