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如何判定电学中“电表示数的变化”
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作者 周家辉 余爱春 《物理教学探讨(初三年级学研期)》 2004年第1期6-8,共3页
在几年全国各地的中考试题中,常常会出现这样一类题目:滑动变阻器的滑片P向左(或向右)滑动时,来判定电路中电流表、电压表的示数变化情况。此类题目不需要学生做繁琐的定量计算,而是要求学生运用学过的有关电学知识进行定性讨论。
关键词 电学题 解法 “电表示数的变化 中考 物理
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Predicting GM(1,N) Model for the Coefficient of Variation of Hectometer Yarn's Weight 被引量:1
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作者 李晓峰 《Journal of Donghua University(English Edition)》 EI CAS 2010年第3期391-394,共4页
The Coefficient of Variation(CV)of hectometer yarn's weight is one of the guidelines to evaluate its intrinsic quality.In the spinning manufacturing,the control of cotton yarn's weight unevenness is accomplish... The Coefficient of Variation(CV)of hectometer yarn's weight is one of the guidelines to evaluate its intrinsic quality.In the spinning manufacturing,the control of cotton yarn's weight unevenness is accomplished mainly in terms of a spot-check on semi-product and a succedent adjust in process parameters during spinning based on technicians' experience.However,it is theoretically believed among manufacturers that with fixed technical levels and parameters in the spinning process,the quality parameters of assorted cotton have a certain influence on the CV.In order to find out a rule of the influence that assorted cotton has on the CV,a GM(1,N)model,correlated raw cotton's quality parameter with the CV,has firstly been developed according to the modeling theory of grey system,and then been applied in the designing step to predict the CV.It has been approved by practical modeling and validation that the model could fit preferably an accrual CV value,and provide a method of quantitative predicting analysis for textile manufacturers to design cotton yarn's quality. 展开更多
关键词 cotton yarn coefficient of variation(CV) raw cotton's quality GM(1 N) PREDICTION
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突破高考短文改错中的0分
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作者 杨晓敏 《中华少年》 2017年第25期293-293,共1页
高考英语中的短文改错是考查学生书面表达中的自我纠错能力。要求学生在书面表达中有好很好的对语法知识的运用和掌握能力。是高中英语学习也是英语高考中的难点之一。对于基础薄弱的血色好难过更是如此。要帮助基础薄弱的学生突破高考... 高考英语中的短文改错是考查学生书面表达中的自我纠错能力。要求学生在书面表达中有好很好的对语法知识的运用和掌握能力。是高中英语学习也是英语高考中的难点之一。对于基础薄弱的血色好难过更是如此。要帮助基础薄弱的学生突破高考英语短文改错的0分。最好的办法就是从最基础最主要的知识技能抓起。就是从动词的时态变化和,和英语实词的数的变化抓起。学生才能学有所得,学有所获。 展开更多
关键词 高中英语 短文改错 时态变化 数的变化 突破0分
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A review of 20 years of naive tests of significance for high-dimensional mean vectors and covariance matrices 被引量:1
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作者 HU Jiang BAI ZhiDong 《Science China Mathematics》 SCIE CSCD 2016年第12期2281-2300,共20页
We introduce the so-called naive tests and give a brief review of the new developments. Naive testing methods are easy to understand and perform robustly, especially when the dimension is large. We focus mainly on rev... We introduce the so-called naive tests and give a brief review of the new developments. Naive testing methods are easy to understand and perform robustly, especially when the dimension is large. We focus mainly on reviewing some naive testing methods for the mean vectors and covariance matrices of high-dimensional populations, and we believe that this naive testing approach can be used widely in many other testing problems. 展开更多
关键词 naive testing methods hypothesis testing high-dimensional data multivariate analysis of variance(MANOVA)
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Study of Influence of Terrain and Climatic Factors on Groundwater-Level Fluctuation in a Minor River Basin Using GIS
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作者 N.Radhakrishnan L.Elango 《Geo-Spatial Information Science》 2011年第3期190-197,共8页
Terrain environment parameters play a vital role in controlling groundwater movement:its recharge and discharge me-chanisms.Many earlier studies have been conducted relating terrain parameters and groundwater conditio... Terrain environment parameters play a vital role in controlling groundwater movement:its recharge and discharge me-chanisms.Many earlier studies have been conducted relating terrain parameters and groundwater condition using conventional me-thods and remote sensing techniques.This study,however,endeavors to spatially visualize the degree of fluctuation in the ground-water level of Ongur,a minor river basin in different terrain units under different seasons(monsoon and summer) for three histori-cal periods of time using Geographic Information System(GIS) raster analysis. 展开更多
关键词 GROUNDWATER river basin terrain environment parameters seasonal fluctuations GIS
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Time-varying latent model for longitudinal data with informative observation and terminal event times
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作者 PEI YanBo DU Ting SUN LiuQuan 《Science China Mathematics》 SCIE CSCD 2016年第12期2393-2410,共18页
Longitudinal data often occur in follow-up studies, and in many situations, there may exist informative observation times and a dependent terminal event such as death that stops the follow-up. We propose a semiparamet... Longitudinal data often occur in follow-up studies, and in many situations, there may exist informative observation times and a dependent terminal event such as death that stops the follow-up. We propose a semiparametric mixed effect model with time-varying latent effects in the analysis of longitudinal data with informative observation times and a dependent terminal event. Estimating equation approaches are developed for parameter estimation, and asymptotic properties of the resulting estimators are established. The finite sample behavior of the proposed estimators is evaluated through simulation studies, and an application to a bladder cancer study is provided. 展开更多
关键词 estimating equations informative observation times joint modeling longitudinal data terminal event time-varying effect
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A multi-functional dynamic state estimator for error validation:measurement and parameter errors and sudden load changes
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作者 Mehdi AHMADI JIRDEHI Reza HEMMATI +1 位作者 Vahid ABBASI Hedayat SABOORI 《Frontiers of Information Technology & Electronic Engineering》 SCIE EI CSCD 2016年第11期1218-1227,共10页
We propose a new and efficient algorithm to detect, identify, and correct measurement errors and branch parameter errors of power systems. A dynamic state estimation algorithm is used based on the Kalman filter theory... We propose a new and efficient algorithm to detect, identify, and correct measurement errors and branch parameter errors of power systems. A dynamic state estimation algorithm is used based on the Kalman filter theory. The proposed algorithm also successfully detects and identifies sudden load changes in power systems. The method uses three normalized vectors to process errors at each sampling time: normalized measurement residual, normalized Lagrange multiplier, and normalized innovation vector. An IEEE 14-bus test system was used to verify and demonstrate the effectiveness of the proposed method. Numerical results are presented and discussed to show the accuracy of the method. 展开更多
关键词 Dynamic state estimation Kalman filter Measurement errors Branch parameter errors Sudden load changes
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