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Generalizations of mixed weighted power mean inequality 被引量:1
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作者 马统一 张海娟 《Journal of Shanghai University(English Edition)》 CAS 2006年第3期192-197,共6页
Tarnavas established mixed weighted power mean inequality in 1999. A separation of weighted power mean inequslity was derived in this paper. As its applications, some separations of other inequalities were given.
关键词 INEQUALITY power mean weighted power mean mixed weighted power mean difference function of mixed weightedpower mean separation
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Sharp power mean bounds for Seiffert mean 被引量:4
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作者 LI Yong-min WANG Miao-kun CHU Yu-ming 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2014年第1期101-107,共7页
In this paper, we find the greatest value p = log 2/(log Tr - log 2) = 1.53.- and the least value q -- 5/3 - 1.66.. such that the double inequality Mp(a,b) 〈 T(a,b) 〈 Mq(a,b) holds for all a, b 〉 0 with a #... In this paper, we find the greatest value p = log 2/(log Tr - log 2) = 1.53.- and the least value q -- 5/3 - 1.66.. such that the double inequality Mp(a,b) 〈 T(a,b) 〈 Mq(a,b) holds for all a, b 〉 0 with a # b. Here, Mp(a, b) and T(a, b) are the p-th power and Seiffertmeans of two positive numbers a and b, respectively. 展开更多
关键词 power mean Seiffert mean INEQUALITY
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On the Fourth Power Mean of Generalized Three-Term Exponential Sums 被引量:3
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作者 Xiancun DU Xiaoxue LI 《Journal of Mathematical Research with Applications》 CSCD 2015年第1期92-96,共5页
The main purpose of this paper is using estimates for trigonometric sums and properties of congruence to study the computation of one kind of fourth power mean of a generalized three-term exponential sum, and give an ... The main purpose of this paper is using estimates for trigonometric sums and properties of congruence to study the computation of one kind of fourth power mean of a generalized three-term exponential sum, and give an interesting identity for it. 展开更多
关键词 generalized three-term exponential sums fourth power mean IDENTITY
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On the Fourth Power Mean of Generalized Three-Term Exponential Sums 被引量:1
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作者 Huaning LIU Wanmei LI 《Journal of Mathematical Research with Applications》 CSCD 2017年第2期169-182,共14页
The computational problem of fourth power mean of generalized three-term exponential sums is studied by using the trigonometric identity and the properties of the reduced residue system. Some explicit formulas for the... The computational problem of fourth power mean of generalized three-term exponential sums is studied by using the trigonometric identity and the properties of the reduced residue system. Some explicit formulas for the fourth power mean of generalized three-term exponential sums under different conditions are given. 展开更多
关键词 generalized three-term exponential sum IDENTITY fourth power mean formula
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The Hybrid Power Mean Involving the Character Sum of Polynomials and a Sum Analogous to Kloosterman Sum
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作者 LU Xingxing ZHANG Wenpeng 《数学进展》 CSCD 北大核心 2024年第6期1199-1209,共11页
The main purpose of this paper is using the properties of the classical Gauss sum and the analytic methods to study the computational problem of one kind of hybrid power mean involving the character sum of polynomials... The main purpose of this paper is using the properties of the classical Gauss sum and the analytic methods to study the computational problem of one kind of hybrid power mean involving the character sum of polynomials and a sum analogous to Kloosterman sum mod p,an odd prime,and give two sharp asymptotic formulae for them. 展开更多
关键词 character sum of polynomials a sum analogous to Kloosterman sum hybrid power mean the classical Gauss sum analytic method asymptotic formula
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Sharps Bounds for Power Mean in Terms of Contraharmonic Mean
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作者 Zeid I. Almuhiameed 《Journal of Applied Mathematics and Physics》 2020年第7期1229-1235,共7页
In this research work, we consider the below inequalities: (1.1). The researchers attempt to find an answer as to what are the best possible parameters <i><i>&#945;</i></i>, <i><i&... In this research work, we consider the below inequalities: (1.1). The researchers attempt to find an answer as to what are the best possible parameters <i><i>&#945;</i></i>, <i><i>&#946;</i></i> that (1.1) can be held? The main tool is the optimization of some suitable functions that we seek to find out. Without loss of generality, we have assumed that <i>a</i> > <i>b</i> and let <img src="Edit_26c0f99b-93dd-48ff-acdb-f1c8047744f1.bmp" alt="" /> for 1) and <i>a</i> < <i>b</i>, <img src="Edit_15c32a7a-e9ae-41d3-8f49-c6b9c01c7ece.bmp" alt="" />(<i>t</i> small) for 2) to determine the condition for <i><i>&#945;</i></i> and <i><i>&#946;</i></i> to become <i>f</i>(<i>t</i>) ≤ 0 and <i>g</i>(<i>t</i>) ≥ 0. 展开更多
关键词 Sharps Bounds power mean Contraharmonic mean
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On the Fourth Power Mean of the Character Sums Over Short Intervals 被引量:3
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作者 Wen Peng ZHANG Xiao Ying WANG 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2007年第1期153-164,共12页
The main purpose of this paper is to study the mean value properties of the character sums over the interval [1,p/8) by using the mean value theorems of the Dirichlet L-functions, and give an interesting mean value f... The main purpose of this paper is to study the mean value properties of the character sums over the interval [1,p/8) by using the mean value theorems of the Dirichlet L-functions, and give an interesting mean value formula for this study. 展开更多
关键词 character sums short intervals fourth power mean asymptotic formula
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On the Sixth Power Mean of the Two-term Exponential Sums 被引量:5
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作者 Wen Peng ZHANG Yuan Yuan MENG 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2022年第3期510-518,共9页
The main purpose of this article is to study the calculating problem of the sixth power mean of the two-term exponential sums,and give an interesting calculating formula for it.At the same time,the paper also provides... The main purpose of this article is to study the calculating problem of the sixth power mean of the two-term exponential sums,and give an interesting calculating formula for it.At the same time,the paper also provides a new and effective method for the study of the high order power mean of the exponential sums. 展开更多
关键词 The two-term exponential sums the sixth power mean
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ON THE GENERAL k-TH KLOOSTERMAN SUMS AND ITS FOURTH POWER MEAN 被引量:2
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作者 LIUHONGYAN ZHANGWENPENG 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2004年第1期97-102,共6页
The main purpose of this paper is to study the asymptotic property of the fourth power mean of the general k-th Kloosterman sums, and give an interesting asymptotic formula.
关键词 General k-th Kloosterman sums Fourth power mean Asymptotic for-mula
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On the Fourth Power Mean of the Generalized Quadratic Gauss Sums
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作者 Wen Peng ZHANG Xin LIN 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2018年第6期1037-1049,共13页
The main purpose of this paper is to use elementary methods and properties of the classical Gauss sums to study the computational problem of one kind of fourth power mean of the generalized quadratic Gauss sums mod q ... The main purpose of this paper is to use elementary methods and properties of the classical Gauss sums to study the computational problem of one kind of fourth power mean of the generalized quadratic Gauss sums mod q (a positive odd number), and give an exact computational formula for it. 展开更多
关键词 The generalized quadratic Gauss sums the fourth power mean analytic method computational formula
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On the Hybrid Power Mean Involving the Two-Term Exponential Sums and Polynomial Character Sums
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作者 Xingxing LV Xiaoxue LI 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2020年第4期547-558,共12页
The main purpose of this paper is using the analytic method and the properties of trigonometric sums and character sums to study the computational problem of one kind hybrid power mean involving two-term exponential s... The main purpose of this paper is using the analytic method and the properties of trigonometric sums and character sums to study the computational problem of one kind hybrid power mean involving two-term exponential sums and polynomial character sums.Then the authors give some interesting calculating formulae for them. 展开更多
关键词 The two-term exponential sums Kloosterman sums Dirichlet character of polynomials Hybrid power mean IDENTITY
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Does Being a Big Power Mean Paying a Big Bill? Japan's UN funding proposal appears to disguise political motives
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作者 ZHOU YONGSHENG is a professor of China Foreign Affairs University 《Beijing Review》 2006年第14期13-,共1页
Japan, which is increasingly frustrated that it has not been granted a permanent seat on the UN Security Council, has found a new outlet of displeasure against the world body. On March 10, Japan proposed to the UN Gen... Japan, which is increasingly frustrated that it has not been granted a permanent seat on the UN Security Council, has found a new outlet of displeasure against the world body. On March 10, Japan proposed to the UN General Assembly budget committee, 展开更多
关键词 UN Does Being a Big power mean Paying a Big Bill Japan’s UN funding proposal appears to disguise political motives GDP Security
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The Fourth Power Mean of the General 3-dimensional Kloostermann Sums mod p 被引量:3
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作者 Wen Peng ZHANG Xing Xing LV 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2019年第3期369-377,共9页
The main purpose of this paper is using the analytic methods, the solutions of the congruence equation mod p and the properties of Gauss sums to study the computational problem of one kind fourth power mean of the gen... The main purpose of this paper is using the analytic methods, the solutions of the congruence equation mod p and the properties of Gauss sums to study the computational problem of one kind fourth power mean of the general 3-dimensional Kloostermann sums mod p, and give a sharp asymptotic formula for it. 展开更多
关键词 The general 3-dimensional Kloostermann SUMS the FOURTH power mean DIRICHLET CHARACTER ASYMPTOTIC FORMULA
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A Short-Term PV Power Forecasting Method Using a Hybrid Kmeans-GRA-SVR Model under Ideal Weather Condition 被引量:2
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作者 Jiemin Lin Haiming Li 《Journal of Computer and Communications》 2020年第11期102-119,共18页
With the continuous increase of solar penetration rate, it has brought challenges to the smooth operation of the power grid. Therefore, to make photovoltaic power generation not affect the smooth operation of the grid... With the continuous increase of solar penetration rate, it has brought challenges to the smooth operation of the power grid. Therefore, to make photovoltaic power generation not affect the smooth operation of the grid, accurate photovoltaic power prediction is required. And short-term forecasting is essential for the deployment of daily power generation plans. In this paper, A short-term photovoltaic power generation forecast method based on K-means++, grey relational analysis (GRA) and support vector regression (SVR) (Hybrid Kmeans-GRA-SVR, HKGSVR) was proposed. The historical power data was clustered through the multi-index K-means++ algorithm. And the similar days and the nearest neighbor similar day of the prediction day were selected by the GRA algorithm. Then, similar days and nearest neighbor similar days were used to train SVR to obtain an accurate photovoltaic power prediction model. Under ideal weather, the average values of MAE, RMSE, and R<sup>2</sup> were 0.8101 kW, 0.9608 kW, and 99.66%, respectively. The average computation time was 1.7487 s, which was significantly better than the SVR model. Thus, the demonstrated numerical results verify the effectiveness of the proposed model for short-term PV power prediction. 展开更多
关键词 Grey Relational Analysis K-means++ Nearest Neighbor Similar Day Photovoltaic power Support Vector Regression
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基于K-Means聚类算法的直流电网换流器故障自动化检测系统 被引量:1
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作者 翁子韵 《自动化与仪表》 2025年第4期86-90,共5页
直流电网换流器结构复杂、监测信号较多,为了自动从大量监测信号中筛选关键特征,准确识别电网换流器故障,设计基于K-Means聚类算法的直流电网换流器故障自动化检测系统。采集的各线路电压信号,采用改进主成分分析法将高维的监测信号数... 直流电网换流器结构复杂、监测信号较多,为了自动从大量监测信号中筛选关键特征,准确识别电网换流器故障,设计基于K-Means聚类算法的直流电网换流器故障自动化检测系统。采集的各线路电压信号,采用改进主成分分析法将高维的监测信号数据降维成少数几个主成分,作为反映线路电压信号的主要特征;通过改进K-Means聚类算法对所提取信号主成分特征进行分组归类,实现电网换流器故障信号分类检测。经测试,此系统对直流电网换流器单极故障、双极故障样本进行聚类识别后,识别结果的误差平方和最大值仅为0.02,可实现高精度的直流电网换流器故障自动化检测。 展开更多
关键词 主成分分析法 K-meanS聚类算法 直流电网 换流器 故障检测 自动化
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A Hybrid K-Means-GRA-SVR Model Based on Feature Selection for Day-Ahead Prediction of Photovoltaic Power Generation
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作者 Jiemin Lin Haiming Li 《Journal of Computer and Communications》 2021年第11期91-111,共21页
In order to ensure that the large-scale application of photovoltaic power generation does not affect the stability of the grid, accurate photovoltaic (PV) power generation forecast is essential. A short-term PV power ... In order to ensure that the large-scale application of photovoltaic power generation does not affect the stability of the grid, accurate photovoltaic (PV) power generation forecast is essential. A short-term PV power generation forecast method using the combination of K-means++, grey relational analysis (GRA) and support vector regression (SVR) based on feature selection (Hybrid Kmeans-GRA-SVR, HKGSVR) was proposed. The historical power data were clustered through the multi-index K-means++ algorithm and divided into ideal and non-ideal weather. The GRA algorithm was used to match the similar day and the nearest neighbor similar day of the prediction day. And selected appropriate input features for different weather types to train the SVR model. Under ideal weather, the average values of MAE, RMSE and R2 were 0.8101, 0.9608 kW and 99.66%, respectively. And this method reduced the average training time by 77.27% compared with the standard SVR model. Under non-ideal weather conditions, the average values of MAE, RMSE and R2 were 1.8337, 2.1379 kW and 98.47%, respectively. And this method reduced the average training time of the standard SVR model by 98.07%. The experimental results show that the prediction accuracy of the proposed model is significantly improved compared to the other five models, which verify the effectiveness of the method. 展开更多
关键词 Feature Selection Grey Relational Analysis K-means++ Nearest Neighbor Similar Day Photovoltaic power Support Vector Regression
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基于K-Means聚类与Ridge回归算法的煤炭发热量预测研究 被引量:2
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作者 乔世超 陈衡 +2 位作者 李博 潘佩媛 徐钢 《发电技术》 2025年第1期135-144,共10页
【目的】煤炭发热量是衡量煤质的重要评价标准之一,也是动力用煤计价的主要依据。为了能够在降低预测成本的前提下实现对煤炭发热量的高精度快速预测,提出了一种新的预测方法。【方法】采用K-Means聚类算法对相似煤种进行聚类,样本数据... 【目的】煤炭发热量是衡量煤质的重要评价标准之一,也是动力用煤计价的主要依据。为了能够在降低预测成本的前提下实现对煤炭发热量的高精度快速预测,提出了一种新的预测方法。【方法】采用K-Means聚类算法对相似煤种进行聚类,样本数据来源于山东某电厂自备煤场近6年的4269条入场化验信息。在聚类的基础上,分别建立工业分析数据低位发热量的Ridge回归模型,以此作为煤炭发热量的预测模型。【结果】所建立的K-Means聚类与Ridge回归混合模型在预测效果上表现出色。与传统的多元线性回归模型相比,该混合模型可将平均绝对值误差最高减少30.525%,均方根误差最高降低60.054%,相关系数最高提高2.320%。【结论】K-Means聚类与Ridge回归混合模型不仅降低了煤炭发热量的预测成本,还提高了预测的精度和速度,为煤炭发热量的预测提供了一种新思路。 展开更多
关键词 燃煤电厂 煤炭发热量 工业分析 预测 K-meanS聚类 Ridge回归
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基于改进K-means聚类算法的负荷建模及应用 被引量:42
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作者 白雪峰 蒋国栋 《电力自动化设备》 EI CSCD 北大核心 2010年第7期80-83,共4页
根据数据所处区域的数据密度选择初始聚类中心以充分反映数据的分布特征;在迭代计算新的聚类中心时,利用数据与类中心的平均距离作为新一轮迭代的聚类中心以排除噪声点的影响;通过集群评估指标DBI(Davies-Bouldin Index)选择最优聚类个... 根据数据所处区域的数据密度选择初始聚类中心以充分反映数据的分布特征;在迭代计算新的聚类中心时,利用数据与类中心的平均距离作为新一轮迭代的聚类中心以排除噪声点的影响;通过集群评估指标DBI(Davies-Bouldin Index)选择最优聚类个数,以更准确地反映数据空间分布的特征。利用改进K-means算法对某省变电所数据进行聚类分析,得到负荷特征数据,并在此基础上建立了分段3次Hermite插值函数负荷模型。算例分析表明基于改进K-means的负荷建模方法对电网仿真分析可行、有效。 展开更多
关键词 电力系统 K-meanS 聚类分析 负荷建模
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THE OPTIMAL GENERALIZED LOGARITHMIC MEAN BOUNDS FOR SEIFFERT'S MEAN 被引量:3
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作者 褚玉明 王淼坤 王根娣 《Acta Mathematica Scientia》 SCIE CSCD 2012年第4期1619-1626,共8页
For p ∈ R, the generalized logarithmic mean Lp(a, b) and Seiffert's mean T(a, b) of two positive real numbers a and b are defined in (1.1) and (1.2) below respectively. In this paper, we find the greatest p ... For p ∈ R, the generalized logarithmic mean Lp(a, b) and Seiffert's mean T(a, b) of two positive real numbers a and b are defined in (1.1) and (1.2) below respectively. In this paper, we find the greatest p and least q such that the double-inequality Lp(a, b) 〈 T(a,b) 〈 Lq(a,b) holds for all a,b 〉 0 and a ≠ b. 展开更多
关键词 generalized logarithmic mean Seiffert's mean power mean
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基于K-means和改进KNN算法的风电功率短期预测系统 被引量:9
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作者 何建强 张玉萍 滕志军 《计算机测量与控制》 2022年第5期156-162,共7页
为提高风电功率短期预测的准确性,针对KNN(K-Nearest neighbor algorithm)算法在风电功率预测中的不足,提出了基于K-means和改进KNN算法的风电功率短期预测方法;利用K-means聚类方法确定风电历史样本的类别,对KNN算法中搜索相似历史样... 为提高风电功率短期预测的准确性,针对KNN(K-Nearest neighbor algorithm)算法在风电功率预测中的不足,提出了基于K-means和改进KNN算法的风电功率短期预测方法;利用K-means聚类方法确定风电历史样本的类别,对KNN算法中搜索相似历史样本集的方式进行了改进和优化,构建了预测模型,并采用C/S架构实现了预测系统的设计;该系统具有自修正功能,能够随着预测次数的增加,不断修正预测模型,逐渐降低预测的误差率;以吉林省某风电场历史数据为样本进行了仿真分析,结果显示该算法与其它算法相比平均绝对误差和均方根误差最大下降1.08%和0.48%,运算时间提升了5.45%,在风电功率超短期多步预测中具有推广应用价值。 展开更多
关键词 风电功率 预测 K-meanS聚类算法 改进KNN算法
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