| 摘 要: 关系代数语言是用传统的集合运算和专门的关系运算来表达查询的抽象语言，提供了一系列的关系代数 操作，通过这种数学运行来指导数据库在关系操作上的程序实现。场景教学系统中每一个场景对应一个实际应用，场景 中设置了问题，本文以系统数据库为例，给出了基于关系代数运算的数据统计分析过程，采用抽取样本法计算期望学习 时长和学习时长标准差，并设计了一个测算学习者投入度的公式，对评价场景教学具有指导意义。 |
| 关键词: 场景教学；数据库；关系代数运算 |
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中图分类号: TP391
文献标识码: A
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| 基金项目: 湖北省教育厅科学技术研究项目“云平台场景的构建及其在高职软件技术专业教学中的应用研究”(项目编号：B2017519). |
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| Statistics and Analysis of Data Based on Relational Algebra Operations —A Case Study of the Scene Teaching System Database |
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TANG Juan,PAN Zhian
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( Hubei Polytechnic Institute, Xiaogan 432000, China)
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| Abstract: The relational algebra language is an abstract language that expresses queries by traditional set operations and special relational operations.It provides a series of relational algebraic operations,which can guide the implementation of relational operations in database.Every scene in the scene teaching system corresponds to a practical application.Questions are set in the scene.Taking the database of the system as an example,this paper presents the statistical analysis process of data based on relational algebraic operation,calculates the standard deviation of expected learning time and learning time by sampling method,and designs a formula to measure learner's engagement,which has directional significance for evaluating the scene teaching |
| Keywords: scene teaching;database;relational algebra operations |
