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计数棒:算理与算法有效融合的实践研究
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作者 徐英姿 《小学教学参考》 2024年第14期46-49,共4页
文章通过梳理教材,发现数与代数领域中的常见工具——计数棒,并分析学生的学习起点,把握学生的认知水平,充分利用计数棒设计课堂教学内容,让课堂教学更精准,让学生理解算理更深刻,使学生的计算素养得以提升。
关键词 计数棒 算理 算法 数与代数
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一种抗噪分形维计算方法及其在声纳图像识别中的应用 被引量:3
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作者 杨词银 许枫 《应用声学》 CSCD 北大核心 2008年第2期95-101,共7页
用于计算图像分形维的差分盒计数法(DBC)和鲁棒差分盒计数法(RDBC)都对脉冲噪声和斑点噪声较敏感,为此本文提出一种抗噪差分盒计数法(NRDBC),利用剪切局部标准差(TLSD)来计算图像分形维,由于TLSD可有效滤除脉冲噪声和斑点噪声、且对高... 用于计算图像分形维的差分盒计数法(DBC)和鲁棒差分盒计数法(RDBC)都对脉冲噪声和斑点噪声较敏感,为此本文提出一种抗噪差分盒计数法(NRDBC),利用剪切局部标准差(TLSD)来计算图像分形维,由于TLSD可有效滤除脉冲噪声和斑点噪声、且对高斯噪声敏感性小,因此NRDBC能对有噪图像进行可靠的分形维估计。利用多分辨率的DBC、RDBC和NRDBC对混有高斯噪声、脉冲噪声和斑点噪声的7种Brodatz纹理以及3种海底的侧扫声纳图像进行了分类实验,结果表明,本文提出的NRDBC可获得更高的识别率和更好的抗噪性。 展开更多
关键词 分形维 差分盒计数 差分盒计数 抗噪差分盒计数 剪切局部标准差
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《孙子算经》中筹算对儿童运算思维能力培养的效用分析
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作者 杨丽星 肖良凯 《老字号品牌营销》 2020年第3期102-103,共2页
算筹是中国古代在数学领域使用的一种计算工具,利用算筹作计算工具的数学就叫筹算数学。算筹在数学领域涉及到计算中简单的加减乘除四则运算,而以加减乘除为基础的数学计算又是儿童在数学领域必须学习和最早接触的数学计算。因此,筹算... 算筹是中国古代在数学领域使用的一种计算工具,利用算筹作计算工具的数学就叫筹算数学。算筹在数学领域涉及到计算中简单的加减乘除四则运算,而以加减乘除为基础的数学计算又是儿童在数学领域必须学习和最早接触的数学计算。因此,筹算数学与儿童早期运算思维能力的培养有着紧密的联系。通过对算筹中涉及到的加减乘除四则运算的分析和研究,我们发现算筹中所使用的以竹、木棍等为计算媒介的计算方法与儿童早期建立起来的以功能符号为主的运算思维能力的培养有着相似之处,算筹对儿童思维运算能力的培养有着可以值得借鉴的地方。本文试图通过对算筹中加减乘除的计算演化方式的推导和对儿童加减乘除运算思维能力的分析,建立起一种以算筹的分析模式来开发儿童运算思维能力的可行性途径。 展开更多
关键词 计数棒 算筹 儿童 运算
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Data driven particle size estimation of hematite grinding process using stochastic configuration network with robust technique 被引量:6
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作者 DAI Wei LI De-peng +1 位作者 CHEN Qi-xin CHAI Tian-you 《Journal of Central South University》 SCIE EI CAS CSCD 2019年第1期43-62,共20页
As a production quality index of hematite grinding process,particle size(PS)is hard to be measured in real time.To achieve the PS estimation,this paper proposes a novel data driven model of PS using stochastic configu... As a production quality index of hematite grinding process,particle size(PS)is hard to be measured in real time.To achieve the PS estimation,this paper proposes a novel data driven model of PS using stochastic configuration network(SCN)with robust technique,namely,robust SCN(RSCN).Firstly,this paper proves the universal approximation property of RSCN with weighted least squares technique.Secondly,three robust algorithms are presented by employing M-estimation with Huber loss function,M-estimation with interquartile range(IQR)and nonparametric kernel density estimation(NKDE)function respectively to set the penalty weight.Comparison experiments are first carried out based on the UCI standard data sets to verify the effectiveness of these methods,and then the data-driven PS model based on the robust algorithms are established and verified.Experimental results show that the RSCN has an excellent performance for the PS estimation. 展开更多
关键词 hematite grinding process particle size stochastic configuration network robust technique M-estimation nonparametric kernel density estimation
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Orthogonal Arrays Robust to a Specified Set of Nonnegligible Effects 被引量:1
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作者 CHEN Xueping LIN Jinguan 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2016年第2期531-541,共11页
This paper considers experimental situations where the interested effects have to be or- thogonal to a set of nonnegligible effects. It is shown that various types of orthogonal arrays with mixed strength are A-optima... This paper considers experimental situations where the interested effects have to be or- thogonal to a set of nonnegligible effects. It is shown that various types of orthogonal arrays with mixed strength are A-optimal for estimating the parameters in ANOVA high dimension model representation. Both cases including interactions or not are considered in the model. In particularly, the estimations of all main effects are A-optimal in a mixed strength (2, 2)3 orthogonal array and the estimations of all main effects and two-factor interactions in G~ x G~ are A-optimal in a mixed strength (2, 2)4 orthogonal array. The properties are also illustrated through a simulation study. 展开更多
关键词 Design of experiment matrix image orthogonal array robust design.
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Robust estimation in inverse problems via quantile coupling 被引量:2
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作者 TIAN MaoZai 《Science China Mathematics》 SCIE 2012年第5期1029-1041,共13页
In this article we consider a sequence of hierarchical space model of inverse problems.The underlying function is estimated from indirect observations over a variety of error distributions including those that are hea... In this article we consider a sequence of hierarchical space model of inverse problems.The underlying function is estimated from indirect observations over a variety of error distributions including those that are heavy-tailed and may not even possess variances or means.The main contribution of this paper is that we establish some oracle inequalities for the inverse problems by using quantile coupling technique that gives a tight bound for the quantile coupling between an arbitrary sample p-quantile and a normal variable,and an automatic selection principle for the nonrandom filters.This leads to the data-driven choice of weights.We also give an algorithm for its implementation.The quantile coupling inequality developed in this paper is of independent interest,because it includes the median coupling inequality in literature as a special case. 展开更多
关键词 inverse problem robust estimation oracle inequalities quantile coupling inequalities heavy-tailed distributions hierarchical sequence space model
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Estimation of rod-like phase spacing in melt-grown eutectic composites
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作者 MENG GuangHui XIE Hui LIN Xin 《Science China(Technological Sciences)》 SCIE EI CAS 2014年第9期1794-1801,共8页
Directional solidification of rod-like eutectic is an important route to produce in situ composites.The rod-like phase spacing of composites is a crucial parameter in determining the properties of the materials.In thi... Directional solidification of rod-like eutectic is an important route to produce in situ composites.The rod-like phase spacing of composites is a crucial parameter in determining the properties of the materials.In this study,the rod-like phase spacing of melt-grown in situ eutectic composites is estimated by the method that is established based on the classical Jackson-Hunt theory and completed by considering the minimum undercooling principle in eutectic solidification at steady state.The density difference between the solid phases is also considered when calculating the diffusion field in the liquid.It is found that the rod-like phase spacing of in situ eutectic composites is generally a not unique value but displays a finite range under fixed growth conditions.Also,the range width,which decreases with increasing growth rate and vice versa,is only dependent on the intrinsic properties of an alloy at a given growth rate.By comparing with the experimental observations,the results show that the predicted spacings are in reasonable agreement with experimental data for nonfaceted-nonfaceted Succinonitrile-(D)camphor,MnSb-Sb,and Al-Al3Ni alloys and faceted-nonfaceted MnBi-Bi system when growing in a coupled manner. 展开更多
关键词 solidification in situ composite rod-like phase spacing eutectic alloy coupled growth
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