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计算机智能辅助评分系统定标集选取和优化方法研究 被引量:6
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作者 何屹松 孙媛媛 +1 位作者 张凯 付瑞吉 《中国考试》 CSSCI 2020年第1期30-36,共7页
在计算机智能评分研究中,选取定标样本对建立评分模型至关重要。通过对不同定标集人机评分的对比研究,提出“专家随机抽取+智能挑选样卷+聚类分段补充”的定标集选取方法。这种方法提升了评分模型对于各分数段的建模能力,符合高考等考... 在计算机智能评分研究中,选取定标样本对建立评分模型至关重要。通过对不同定标集人机评分的对比研究,提出“专家随机抽取+智能挑选样卷+聚类分段补充”的定标集选取方法。这种方法提升了评分模型对于各分数段的建模能力,符合高考等考试环境下考生成绩呈正态分布的特点,拓展了对专家评分和阅卷教师评分的综合学习能力,使得计算机智能辅助评分系统能够通过深度学习的方法,更加全面地理解和掌握评分标准。 展开更多
关键词 高考 计算机辅助评分系统 作文评分 定标样本
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Effect of sample treatment on determination of arsenic (Ⅲ) and arsenic (Ⅴ) in aqueous and tissue samples by hydride generation atomic absorption spectrometry 被引量:1
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作者 Jamileh Salar-Amoli Tahereh Ali-Esfahani Jalal Hassan 《Journal of Chemistry and Chemical Engineering》 2009年第6期49-53,共5页
The purpose of this procedure was to optimize and improve a method that used for the determination of arsenic (Ⅲ) and arsenic (Ⅴ) in biological and environmental samples. The method is based on hydride generatio... The purpose of this procedure was to optimize and improve a method that used for the determination of arsenic (Ⅲ) and arsenic (Ⅴ) in biological and environmental samples. The method is based on hydride generation and atomic absorption spectrometry. For both As (Ⅲ) and As (Ⅴ) the parameters such as NaBH4, HCI concentration, and pH were optimized. Absorption signal of As (Ⅴ) was approximately 17% of As (Ⅲ) signal. Therefore, for estimation of As (Ⅲ) and As (Ⅴ) concentrations in various samples the difference between the absorbance obtained for arsenic, without and with previous treatment of samples with potassium iodide (KI), can be applied. The calibration graphs were linear (r〉0.99), and the detection limits of the method based on three times the standard deviation of the blank were 0.14 and 0.64 μL^-1 for As (Ⅲ) and As (Ⅴ), respectively. The relative standard deviation (R.S.D.) of measurements was less than 10%. As a means of checking performance method, water samples were spiked with known concentrations of both As (Ⅲ) and As (Ⅴ), and recovery above 94% was obtained. The proposed method was applied successfully to determine inorganic As (Ⅲ) and As (Ⅴ) in various environmental and total As in biological samples. 展开更多
关键词 arsenic speciation hydride generation atomic absorption spectrometry
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