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关于概念的深度学习案例探究——《随机变量的数字特征—方差》
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作者 涂丹 《中文科技期刊数据库(全文版)教育科学》 2021年第2期202-204,共3页
深度学习是在教师的引领下,学生围绕着具有挑战性的学习主题,全身心积极参与、体验成功、获得发展的有意义的学习过程。高中阶段,随着学习难度的增大,许多数学概念不仅抽象,而且复杂程度也很高,在一定程度上造成了学生认知的障碍和学习... 深度学习是在教师的引领下,学生围绕着具有挑战性的学习主题,全身心积极参与、体验成功、获得发展的有意义的学习过程。高中阶段,随着学习难度的增大,许多数学概念不仅抽象,而且复杂程度也很高,在一定程度上造成了学生认知的障碍和学习的困难。因此如何采取有效的教学模式,加强对学生的思维引导,让学生快速吸收掌握这些知识至关重要。本文以新人教B班选修2第四章《4.2.4 随机变量的数字特征》的第二课时,随机变量的方差的概念教学为例探讨如何在深度学习的背景下进行概念教学。 展开更多
关键词 深度学习 概念教学 随机变量方差
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双随机变量证券投资组合决策
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作者 闫立梅 《计算机工程与应用》 CSCD 2012年第12期209-212,228,共5页
将收益率刻画为双随机变量,建立了均值-方差证券投资组合模型;研究并给出了双随机变量期望值和方差的一般计算方法,将模型转化为其确定等价形式;讨论了模型的凸性,证明了模型解的存在性和惟一性;通过数值例子验证了模型和方法的可行性。
关键词 随机变量 投资组合模型 随机变量方差 确定等价类
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省统编教材《概率论与数理统计》中值得商榷的两个问题
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作者 孙永旺 《山东理工大学学报(社会科学版)》 1994年第4期18-20,共3页
本文指出了省统编教材《概率论与数理统计》中,在关于引入随机变量方差的概念时,所举例子不妥之处以及在计算古典概型的例题中出现的错误。
关键词 《概率论与数理统计》 统编教材 值得商榷 古典概型 数学期望 随机变量方差 射击技术 数字 基本事件数 环数
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General Classes of Variance Estimators in Simple Random Sampling Using Multi-auxiliary Variables
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作者 Zahoor Ahmad Shoaib Ali Muhammad Hanif 《Journal of Mathematics and System Science》 2013年第5期262-269,共8页
Srivastava and Jhajj [ 1 6] proposed a class of estimators for estimating population variance using multi auxiliary variables in simple random sampling and they utilized the means and variances of auxiliary variables.... Srivastava and Jhajj [ 1 6] proposed a class of estimators for estimating population variance using multi auxiliary variables in simple random sampling and they utilized the means and variances of auxiliary variables. In this paper, we adapted this class and motivated by Searle [13], and we suggested more generalized class of estimators for estimating the population variance in simple random sampling. The expressions for the mean square error of proposed class have been derived in general form. Besides obtaining the minimized MSE of the proposed and adapted class, it is shown that the adapted classis the special case of the proposed class. Moreover, these theoretical findings are supported by an empirical study of original data. 展开更多
关键词 Variances estimation multi-auxiliary variables simple random sampling mean square errors.
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Asymptotics of the variance of the number of real roots of random trigonometric polynomials 被引量:1
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作者 SU ZhongGen SHAO QiMan 《Science China Mathematics》 SCIE 2012年第11期2347-2366,共20页
Let an, n≥ 1 be a sequence of independent standard normal random variables. Consider the randomtrigonometric polynomial Tn(θ)=∑^n_i=1 aj cos(j θ), 0≤θ≤π and let Nn be the number of real roots of Tn(θ)in... Let an, n≥ 1 be a sequence of independent standard normal random variables. Consider the randomtrigonometric polynomial Tn(θ)=∑^n_i=1 aj cos(j θ), 0≤θ≤π and let Nn be the number of real roots of Tn(θ)in (0, 2π). In this paper it is proved that limn→∞ Var(Nn)/n=co,where 0 〈 co〈 ∞. 展开更多
关键词 variance random trigonometric polynomial
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Strong approximation for ρ-mixing sequences
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作者 LIN ZhengYan ZHAO YueXu 《Science China Mathematics》 SCIE 2012年第10期2159-2182,共24页
We establish strong invariance principles for sums of stationary p-mixing random variables with finite and infinite second moments under weaker mixing rates. Some earlier results are improved. As applications, some re... We establish strong invariance principles for sums of stationary p-mixing random variables with finite and infinite second moments under weaker mixing rates. Some earlier results are improved. As applications, some results of the law of the iterated logarithm with finite and infinite variance are obtained, also a conjecture raised by Shao in 1993 is solved 展开更多
关键词 strong approximation mixing sequence mixing rate infinite variance MARTINGALE
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