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Multi-Criteria Group Decision-Making Method Based on an Improved Single-Valued Neutrosophic Hamacher Weighted Average Operator and Grey Relational Analysis 被引量:1
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作者 Ye Mei Junjie Yang Bo Chen 《Journal of Computer and Communications》 2023年第3期167-188,共22页
This paper proposes a multi-criteria decision-making (MCGDM) method based on the improved single-valued neutrosophic Hamacher weighted averaging (ISNHWA) operator and grey relational analysis (GRA) to overcome the lim... This paper proposes a multi-criteria decision-making (MCGDM) method based on the improved single-valued neutrosophic Hamacher weighted averaging (ISNHWA) operator and grey relational analysis (GRA) to overcome the limitations of present methods based on aggregation operators. First, the limitations of several existing single-valued neutrosophic weighted averaging aggregation operators (i.e. , the single-valued neutrosophic weighted averaging, single-valued neutrosophic weighted algebraic averaging, single-valued neutrosophic weighted Einstein averaging, single-valued neutrosophic Frank weighted averaging, and single-valued neutrosophic Hamacher weighted averaging operators), which can produce some indeterminate terms in the aggregation process, are discussed. Second, an ISNHWA operator was developed to overcome the limitations of existing operators. Third, the properties of the proposed operator, including idempotency, boundedness, monotonicity, and commutativity, were analyzed. Application examples confirmed that the ISNHWA operator and the proposed MCGDM method are rational and effective. The proposed improved ISNHWA operator and MCGDM method can overcome the indeterminate results in some special cases in existing single-valued neutrosophic weighted averaging aggregation operators and MCGDM methods. 展开更多
关键词 Single-valued Neutrosophic Numbers Single-valued Neutrosophic Hamacher Weighted averaging Operator Grey Relational Analysis Multi-Criteria Decision-Making Multi-Criteria Group Decision-Making
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Explicit expressions and recurrence formulas of radial average value for N-dimensional hydrogen atom
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作者 CHEN Chang-yuan, SUN Dong-sheng, LIU You-we, LIU Cheng-lin(Department of Physics, Yancheng Teachers College, Yancheng 224002, China) 《原子与分子物理学报》 CAS CSCD 北大核心 2002年第2期201-204,共4页
In this paper, two recurrence formulas for radial average values of N-dimensional hydrogen atom are derived. Explicit expressions for <n rJ N-2 |r s|n rJ N-2 > are given for 3≥s≥-6. These results can be applie... In this paper, two recurrence formulas for radial average values of N-dimensional hydrogen atom are derived. Explicit expressions for <n rJ N-2 |r s|n rJ N-2 > are given for 3≥s≥-6. These results can be applied to discuss average value of centrifugal potential energy and other physical quantities. The relevant results of the usual hydrogen atom are contained in more general conclusion of this paper as special cases. 展开更多
关键词 量子力学 循环准则 氢原子 电离
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Probability Distribution of Arithmetic Average of China Aviation Network Edge Vertices Nearest Neighbor Average Degree Value and Its Evolutionary Trace Based on Complex Network
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作者 Cheng Xiangjun Yang Fang Xiong Zhihua 《Journal of Traffic and Transportation Engineering》 2024年第4期163-174,共12页
In order to reveal the complex network characteristics and evolution principle of China aviation network,the probability distribution and evolution trace of arithmetic average of edge vertices nearest neighbor average... In order to reveal the complex network characteristics and evolution principle of China aviation network,the probability distribution and evolution trace of arithmetic average of edge vertices nearest neighbor average degree values of China aviation network were studied based on the statistics data of China civil aviation network in 1988,1994,2001,2008 and 2015.According to the theory and method of complex network,the network system was constructed with the city where the airport was located as the network node and the route between cities as the edge of the network.Based on the statistical data,the arithmetic averages of edge vertices nearest neighbor average degree values of China aviation network in 1988,1994,2001,2008 and 2015 were calculated.Using the probability statistical analysis method,it was found that the arithmetic average of edge vertices nearest neighbor average degree values had the probability distribution of normal function and the position parameters and scale parameters of the probability distribution had linear evolution trace. 展开更多
关键词 Complex network China aviation network arithmetic average of edge vertices nearest neighbor average degree value linear evolution trace
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Interval-valued intuitionistic fuzzy aggregation operators 被引量:4
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作者 Weize Wang Xinwang Liu Yong Qin 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2012年第4期574-580,共7页
The notion of the interval-valued intuitionistic fuzzy set (IVIFS) is a generalization of that of the Atanassov's intuitionistic fuzzy set. The fundamental characteristic of IVIFS is that the values of its membersh... The notion of the interval-valued intuitionistic fuzzy set (IVIFS) is a generalization of that of the Atanassov's intuitionistic fuzzy set. The fundamental characteristic of IVIFS is that the values of its membership function and non-membership function are intervals rather than exact numbers. There are various averaging operators defined for IVlFSs. These operators are not monotone with respect to the total order of IVIFS, which is undesirable. This paper shows how such averaging operators can be represented by using additive generators of the product triangular norm, which simplifies and extends the existing constructions. Moreover, two new aggregation operators based on the t.ukasiewicz triangular norm are proposed, which are monotone with respect to the total order of IVIFS. Finally, an application of the interval-valued intuitionistic fuzzy weighted averaging operator is given to multiple criteria decision making. 展开更多
关键词 interval-valued intuitionistic fuzzy set (IVIFS) interval-valued intuitionistic fuzzy weighted averaging (IVlFWA) operator interval-valued intuitionistic fuzzy ordered weighted averaging (IVI-FOWA) operator multiple criteria decision making (MCDM) mono-tonicity.
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A comparison of tectonic ambient shear stress value in China with that in western USA
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作者 陈培善 白彤霞 李保昆 《Acta Seismologica Sinica(English Edition)》 CSCD 2002年第5期503-509,共7页
A method is proposed to estimate average tectonic ambient shear stress value for a region. Thus the average stress values of 19 regions in western USA, and 43 regions (each region is 1010) in Chinese mainland and its ... A method is proposed to estimate average tectonic ambient shear stress value for a region. Thus the average stress values of 19 regions in western USA, and 43 regions (each region is 1010) in Chinese mainland and its surroundings have been obtained. The data of 15 993 earthquakes are from the Internet Centroid Moment Tensor solution made by Harvard University from 1997 to 1999. The results demonstrate that there are highest average stress values in the regions of south California of USA and its off coast sea, reach to 12.0 MPa and 13.7 MPa respectively, then gradually decrease toward north, south, and east. The lowest value is 8.7 MPa and 63% of highest value. The average stress values in northern Xinjiang and in the Chayu region of Tibet are 17.2 and 12.9 MPa respectively. They are highest values in China and higher than USAs. The average stress value in North China, Yunnan, Sichuan, Taiwan is similar to south California of USA. The average stress value in South-North seismic zone is about 13 MPa, a little higher than south California. The distribution of average stress value for two important regions provides basic data for geology. These results are useful to research earthquake activity background and attenuation relation of strong ground motion parameters (e.g. peak acceleration and response spectra). 展开更多
关键词 average tectonic ambient shear stress value comparison of average stress value Chinese mainland and its surroundings western USA
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Comparison of Methods of Estimating Missing Values in Time Series
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作者 I. S. Iwueze E. C. Nwogu +2 位作者 V. U. Nlebedim U. I. Nwosu U. E. Chinyem 《Open Journal of Statistics》 2018年第2期390-399,共10页
This paper proposes new methods of estimating missing values in time series data while comparing them with existing methods. The new methods are based on the row, column and overall averages of time series data arrang... This paper proposes new methods of estimating missing values in time series data while comparing them with existing methods. The new methods are based on the row, column and overall averages of time series data arranged in a Buys-Ballot table with m rows and s columns. The methods assume that 1) only one value is missing at a time, 2) the trending curve may be linear, quadratic or exponential and 3) the decomposition method is either Additive or Multiplicative. The performances of the methods are assessed by comparing accuracy measures (MAE, MAPE and RMSE) computed from the deviations of estimates of the missing values from the actual values used in simulation. Results show that, under the stated assumptions, estimates from the new method based on full decomposition of a series is the best (in terms of the accuracy measures) when compared with other two new and the existing methods. 展开更多
关键词 MISSING values Buys-Ballot Table ROW and COLUMN averageS ROW and COLUMN VARIANCES Trend Parameters and Seasonal Indices
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Meridional Distributions of Historical Zonal Averages and Their Use to Quantify the Global and Spheroidal Mean Near-Surface Temperature of the Terrestrial Atmosphere 被引量:1
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作者 Gerhard Kramm Martina Berger +1 位作者 Ralph Dlugi Nicole Molders 《Natural Science》 2020年第3期80-124,共45页
The zonal averages of temperature (the so-called normal temperatures) for numerous parallels of latitude published between 1852 and 1913 by Dove, Forbes, Ferrel, Spitaler, Batchelder, Arrhenius, von Bezold, Hopfner, v... The zonal averages of temperature (the so-called normal temperatures) for numerous parallels of latitude published between 1852 and 1913 by Dove, Forbes, Ferrel, Spitaler, Batchelder, Arrhenius, von Bezold, Hopfner, von Hann, and B&ouml;rnstein were used to quantify the global (spherical) and spheroidal mean near-surface temperature of the terrestrial atmosphere. Only the datasets of Dove and Forbes published in the 1850s provided global averages below 〈T〉=14°C, mainly due to the poor coverage of the Southern Hemisphere by observations during that time. The global averages derived from the distributions of normal temperatures published between 1877 and 1913 ranged from 〈T〉=14.0°C (Batchelder) to 〈T〉=15.1°C (Ferrel). The differences between the global and the spheroidal mean near-surface air temperature are marginal. To examine the uncertainty due to interannual variability and different years considered in the historic zonal mean temperature distributions, the historical normal temperatures were perturbed within ±2σ to obtain ensembles of 50 realizations for each dataset. Numerical integrations of the perturbed distributions indicate uncertainties in the global averages in the range of ±0.3°C to ±0.6°C and depended on the number of available normal temperatures. Compared to our results, the global mean temperature of 〈T〉=15.0°C published by von Hann in 1897 and von Bezold in 1901 and 1906 is notably too high, while 〈T〉=14.4°C published by von Hann in 1908 seems to be more adequate within the range of uncertainty. The HadCRUT4 record provided 〈T〉≌?13.7°C for 1851-1880 and 〈T〉=13.6°C for 1881-1910. The Berkeley record provided 〈T〉=13.6°C and 〈T〉≌?13.5°C for these periods, respectively. The NASA GISS record yielded 〈T〉=13.6°C for 1881-1910 as well. These results are notably lower than those based on the historic zonal means. For 1991-2018, the HadCRUT4, Berkeley, and NASA GISS records provided 〈T〉=14.4°C, 〈T〉=14.5°C, and 〈T〉=14.5°C, respectively. The comparison of the 1991-2018 globally averaged near-surface temperature with those derived from distributions of zonal temperature averages for numerous parallels of latitude suggests no change for the past 100 years. 展开更多
关键词 Global Mean Temperature Spheroidal Mean Temperature Climatological Mean values for the Parallels of Latitude Zonal averages Normal Temperature Temperature Anomaly Isothermal Charts Solar Climate
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Adaptive Strategies for Accelerating the Convergence of Average Cost Markov Decision Processes Using a Moving Average Digital Filter
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作者 Edilson F. Arruda Fabrício Ourique 《American Journal of Operations Research》 2013年第6期514-520,共7页
This paper proposes a technique to accelerate the convergence of the value iteration algorithm applied to discrete average cost Markov decision processes. An adaptive partial information value iteration algorithm is p... This paper proposes a technique to accelerate the convergence of the value iteration algorithm applied to discrete average cost Markov decision processes. An adaptive partial information value iteration algorithm is proposed that updates an increasingly accurate approximate version of the original problem with a view to saving computations at the early iterations, when one is typically far from the optimal solution. The proposed algorithm is compared to classical value iteration for a broad set of adaptive parameters and the results suggest that significant computational savings can be obtained, while also ensuring a robust performance with respect to the parameters. 展开更多
关键词 average Cost MARKOV DECISION Processes value ITERATION Computational EFFORT GRADIENT
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基于IPFA算法和平均影响值的含水层矿井突水水源识别
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作者 乔伟 《中国矿业》 北大核心 2026年第1期261-267,共7页
矿井不同含水层由于导水断层、裂隙网络相互导通,使得具有相似化学特征的水样混杂重叠,并且受到环境等无关冗余数据的干扰,容易造成水样特征类型的误判,降低了突水水源识别准确性。为此提出一种基于IPFA算法和平均影响值的含水层矿井突... 矿井不同含水层由于导水断层、裂隙网络相互导通,使得具有相似化学特征的水样混杂重叠,并且受到环境等无关冗余数据的干扰,容易造成水样特征类型的误判,降低了突水水源识别准确性。为此提出一种基于IPFA算法和平均影响值的含水层矿井突水水源识别方法。采用K-近邻法扩展获取含水层水源化学成分特征间的高维互信息熵,更全面地反映特征之间的关联性,从而筛选出与突水水源识别真正相关的特征,降低冗余特征干扰。使用IPFA算法对极限学习机(ELM)参数展开寻优,提高模型的泛化能力和识别精度,避免ELM陷入最优解,减少混杂重叠的水样相似化学特征类型误判;应用平均响应值(MIV)方法对各个类型特征的MIV值展开计算,筛选平均影响贡献率高的特征,深入理解各特征在水源识别中的作用机制。并构建基于IPFA-ELM-MIV的含水层矿井突水水源识别模型,通过模型完成水源识别。实验结果表明,所提方法通过筛选可以将样本特征的高维互信息熵提升到0.9以上,在9次识别过程中,所提方法出现误判的概率为0,准确识别了含水层矿井突水化学特征类型,提升了矿井不同含水层突水水源识别结果的准确性,并且在不同采样环境下的含水层矿井突水水源识别的R_(1)值高于0.95,具有更强的识别适应性,对于预防和治理矿井突水灾害具有重要意义。 展开更多
关键词 IPFA算法 K-近邻法 平均影响值 极限学习机 含水层矿井 突水水源识别
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The Average Value Inequality in Sequential Effect Algebras 被引量:2
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作者 Jun SHEN Jun De WU 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2010年第5期831-836,共6页
A sequential effect algebra (E, 0, 1, ,o) is an effect algebra on which a sequential product o with certain physics properties is defined; in particular, sequential effect algebra is an important model for studying... A sequential effect algebra (E, 0, 1, ,o) is an effect algebra on which a sequential product o with certain physics properties is defined; in particular, sequential effect algebra is an important model for studying quantum measurement theory. In 2005, Gudder asked the following problem: If a, b E (E, 0, 1, , o) and a⊥b and a o b⊥a o b, is it the case that 2(a o b) ≤ a2 b2 ? In this paper, we construct an example to answer the problem negatively. 展开更多
关键词 effect algebras sequential effect algebras average value inequality
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On the Semivalues and the Least Square Values Average Per Capita Formulas and Relationships
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作者 Irinel DRAGAN 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2006年第5期1539-1548,共10页
In this paper, it is shown that both the Semivalues and the Least Square Values of cooperative transferable utilities games can be expressed in terms of n^2 averages of values of the characteristic function of the gam... In this paper, it is shown that both the Semivalues and the Least Square Values of cooperative transferable utilities games can be expressed in terms of n^2 averages of values of the characteristic function of the game, by means of what we call the Average per capita formulas. Moreover, like the case of the Shapley value earlier considered, the terms of the formulas can be computed in parallel, and an algorithm is derived. From these results, it follows that each of the two values mentioned above are Shapley values of games easily obtained from the given game, and this fact gives another computational opportunity, as soon as the computation of the Shapley value is efficiently done. 展开更多
关键词 Shapley value Semivalues Least Square values average per capita formulas Banzhaf value
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考虑碳排放权交易风险的能源运营商-区域综合能源系统联盟混合博弈优化调度 被引量:2
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作者 刘英培 信明垚 +1 位作者 秦浩然 单泓元 《电力自动化设备》 北大核心 2025年第6期15-22,49,共9页
随着碳排放权交易市场的不断完善,区域综合能源系统(RIES)在参与碳排放权交易时应充分考虑碳价波动的影响。为此,构建以能源运营商为主体、RIES联盟为从体的混合博弈架构。主体以最大化自身效益为目标制定购售电价策略,从体以供能成本... 随着碳排放权交易市场的不断完善,区域综合能源系统(RIES)在参与碳排放权交易时应充分考虑碳价波动的影响。为此,构建以能源运营商为主体、RIES联盟为从体的混合博弈架构。主体以最大化自身效益为目标制定购售电价策略,从体以供能成本和碳交易成本之和最小为目标进行热能交互,建立RIES联盟合作博弈模型。碳交易成本计及碳排放权价格的不确定性,利用自回归差分移动平均模型及广义自回归条件异方差模型预测调度日的碳价,结合条件风险价值,通过设定不同的风险偏好系数及置信度对碳交易价格波动风险进行量化。基于纳什谈判模型将合作博弈问题拆分成2个子问题,在降低联盟总成本的同时,合理分配RIES联盟的合作收益。通过仿真算例结合遗传算法验证所提策略的有效性,结果表明所提模型可以有效平衡系统的经济性和低碳性,降低碳排放权价格波动风险对调度决策的影响。 展开更多
关键词 区域综合能源系统 碳排放权交易风险 混合博弈 纳什谈判 条件风险价值 自回归差分移动平均模型 广义自回归条件异方差模型 优化调度
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中国大陆M_(S)≥5.0地震序列扩展的B?th定律及主要影响因素讨论
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作者 蒋海昆 《地球物理学报》 北大核心 2025年第5期1826-1841,共16页
基于1970—2022年中国大陆M_(S)≥5.0地震序列资料,研究地震序列震级差ΔM=M0-M1统计特征,M0、M1分别为序列首次M_(S)≥5.0地震及后续最大地震震级.统计样本主要分布在青藏地块及周缘地区、天山地震带以及华北—东北地区.研究结果显示,... 基于1970—2022年中国大陆M_(S)≥5.0地震序列资料,研究地震序列震级差ΔM=M0-M1统计特征,M0、M1分别为序列首次M_(S)≥5.0地震及后续最大地震震级.统计样本主要分布在青藏地块及周缘地区、天山地震带以及华北—东北地区.研究结果显示,中国大陆约99%的M_(S)≥5.0地震序列的ΔM分布于[-1.0,4.4]之间,中位值Q2=1.7,平均值ΔM.ΔM分布符合以1.7为均值、以1.1为标准差的正态分布,与M0无关.ΔM具有一定的区域差异,由小到大依次为青藏地块中西部ΔM≈1.5±1.1、青藏地块东部(以南北地震带为主)ΔM≈1.7±1.1、天山地震带ΔM≈1.8±1.1、华北—东北地区ΔM≈2.1±1.1.其中华北—东北地区ΔM显著偏高,青藏地块中西部ΔM明显偏低,与其他构造区差异显著.对比不同震源机制地震序列的ΔM发现,正断型为主的地震序列ΔM≈1.6±1.0、走滑型为主的地震序列ΔM≈1.7±1.0、逆冲型为主的地震序列ΔM≈1.9±1.0,似乎显示一定的震源机制关联性,但无法通过差异显著性检验.中国大陆ΔM的区域性差异可能与区域平均断层运动速率及区域平均能矩比有关,ΔM与区域平均断层运动速率定性负相关、与平均能矩比定性正相关.不同震源机制ΔM之间的差异,可能与震源机制的区域性特征有关.本文采用全部样本的扩展的Bath定律震级差平均值ΔM(≈1.7±1.1),与仅采用主-余型序列样本的经验Bath定律ΔM(≈1.8±1.0)之间,尽管仅相差0.1个震级单位,但Z检验结果显示二者之间差异显著.无论是扩展的Bath定律还是经验Bath定律,中国大陆M_(S)≥5.0地震序列震级差的平均值ΔM均明显偏高于经验Bath定律ΔM≈1.2的预期,但与近几十年来全球大多数区域平均约1.6的研究结果基本一致. 展开更多
关键词 扩展的Båth定律 地震序列震级差ΔM 震级差平均值 的区域差异 中国大陆
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创新价值链视角下建筑业上市公司技术创新效率研究——基于超效率网络SBM模型和BMA方法的实证分析
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作者 程敏 易小凤 王方亮 《运筹与管理》 北大核心 2025年第5期156-163,共8页
为了解建筑业上市公司技术创新效率及其影响因素,基于创新价值链视角,将超效率网络SBM模型和DEA窗口分析法相结合对2016-2020年我国48家建筑业上市公司的技术创新效率进行测度,采用贝叶斯模型平均方法分析其影响因素。研究结果表明:(1)... 为了解建筑业上市公司技术创新效率及其影响因素,基于创新价值链视角,将超效率网络SBM模型和DEA窗口分析法相结合对2016-2020年我国48家建筑业上市公司的技术创新效率进行测度,采用贝叶斯模型平均方法分析其影响因素。研究结果表明:(1)研究期内各年48家企业技术创新效率均值介于0.50~0.54之间,技术创新效率有待提升;(2)根据技术研发效率和成果转化效率将样本企业分为四类,8家企业属于高效集约型、12家企业属于低研发高转化型、9家企业为高研发低转化型、19家企业为粗放低效型;(3)成立年限、成长能力和盈利能力对建筑业上市公司技术创新效率有显著的正向影响,企业规模、研发财力资源投入强度、政府扶持以及研发人力资源投入强度对其有显著的负向影响。最后依据研究结果提出了效率改善的建议。 展开更多
关键词 创新价值链 技术创新效率 建筑业 超效率网络SBM模型 贝叶斯模型平均
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基于复合混沌序列的计算机信息加密算法分析
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作者 刘微 刘冰洲 《微型电脑应用》 2025年第11期238-241,263,共5页
互联网高速发展的当下,计算机信息的加密方法被人们关注。由于图片载有大量信息,所以易被攻击者关注。为了计算机信息的安全,在复合混沌序列中引入压缩技术,将图像由二维转换至一维,在其中引入量子遗传算法,将融合算法在Encrypt数据集... 互联网高速发展的当下,计算机信息的加密方法被人们关注。由于图片载有大量信息,所以易被攻击者关注。为了计算机信息的安全,在复合混沌序列中引入压缩技术,将图像由二维转换至一维,在其中引入量子遗传算法,将融合算法在Encrypt数据集上进行实验,并与复合混沌序列算法、量子遗传算法、黄金正弦算法进行比较。实验结果说明,所提出的算法在加密后,像素之间的相关性均值为0.13%,其他3种算法分别为1.52%、0.86%和0.94%。面对差分攻击时,融合算法被破译后的像素均值为(-1,5),与源图像相差87%,表明所提出的算法在保密计算机信息方面的性能卓越,能有效对抗差分攻击。 展开更多
关键词 复合混沌序列 计算机信息加密算法 压缩技术 量子遗传算法 限制均值
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双端切换拓扑下基于二值通信的多智能体系统容错控制 被引量:1
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作者 王祚 朱延正 +2 位作者 陈新开 杨帆 苏春翌 《自动化学报》 北大核心 2025年第6期1347-1358,共12页
针对一类双端切换拓扑下基于二值通信的多智能体系统,研究其迭代学习容错均值一致性控制问题.为降低通信负担和提高数据传输的安全性,假设每个智能体只能从其邻居处接收到二值信息,建立一类双端切换拓扑结构以调控智能体之间的信息传递... 针对一类双端切换拓扑下基于二值通信的多智能体系统,研究其迭代学习容错均值一致性控制问题.为降低通信负担和提高数据传输的安全性,假设每个智能体只能从其邻居处接收到二值信息,建立一类双端切换拓扑结构以调控智能体之间的信息传递,放宽通信拓扑在时间轴上需要完整生成树的限制.在双迭代尺度框架下,通过二值信息的估计过程和迭代学习控制技术的交替使用,实现对智能体邻居状态的估计,并完成均值一致性控制任务.进一步地,针对系统存在执行器故障的影响,提出一种迭代学习容错均值一致性控制方案,利用迭代学习实现对故障参数的迭代估计,以保证系统在执行器故障影响下的性能.基于非负的复合能量函数理论,证明所得到的误差系统是有界的.最后,利用数值仿真算例验证了所提方法的可行性与有效性. 展开更多
关键词 多智能体系统 二值通信 双端切换拓扑 均值一致性 容错控制 迭代学习控制
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基于平均灰度值与图像融合算法的光伏板积灰程度识别
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作者 陈佳豪 杨建蒙 +1 位作者 李斌 王广溢 《热力发电》 北大核心 2025年第3期131-139,共9页
为了精确分析光伏板积灰情况,采用搭建的光伏积灰可视化实验台,引入平均灰度值参数,对光伏板图像进行数值化分析,验证了光伏板图像的平均灰度值与光伏板积灰密度之间存在明确的对应关系。基于此,采用5种融合方法对双光谱影像融合实验台... 为了精确分析光伏板积灰情况,采用搭建的光伏积灰可视化实验台,引入平均灰度值参数,对光伏板图像进行数值化分析,验证了光伏板图像的平均灰度值与光伏板积灰密度之间存在明确的对应关系。基于此,采用5种融合方法对双光谱影像融合实验台采集的可见光图像与红外图像进行融合,将5类融合图像与可见光图像、红外图像汇总构成图像数据集,对这7类图像进行识别与分析。结果表明红外图像对光伏板积灰程度的识别效果受辐照度的影响最小,精度最高,反映出来的积灰程度变化最明显。该结论可以为积灰规律的研究提供理论基础,对光伏板积灰程度的识别具有重要意义。 展开更多
关键词 积灰检测 平均灰度值 图像融合 积灰程度
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考虑电枢绕组电阻影响的感应子脉冲发电机容性整流系统的平均值模型
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作者 刘龙建 于克训 +1 位作者 谢贤飞 刘志坚 《电机与控制学报》 北大核心 2025年第8期163-172,共10页
现有的感应子脉冲发电机容性整流系统平均值模型忽略了电枢绕组电阻的影响,可能导致仿真结果存在较大误差。本文在计算换流角度和平均电流以及状态方程中均考虑了电枢绕组电阻的影响,并对比分析了电枢绕组电阻影响的不同考虑方式下的仿... 现有的感应子脉冲发电机容性整流系统平均值模型忽略了电枢绕组电阻的影响,可能导致仿真结果存在较大误差。本文在计算换流角度和平均电流以及状态方程中均考虑了电枢绕组电阻的影响,并对比分析了电枢绕组电阻影响的不同考虑方式下的仿真误差,还分析了电阻值大小和仿真误差大小之间的关系。研究结果表明,在换流角度和平均电流计算、状态方程中均考虑电枢绕组电阻时,仿真误差最小;仅在换流角度和平均电流计算中考虑电枢绕组电阻影响时误差最大;在换流角度和平均电流计算中忽略电枢绕组电阻影响会使充电电流仿真值偏小,而在状态方程中忽略电枢绕组电阻影响会使得充电电流仿真值偏大。电阻值越大,则仿真误差越大。最后通过实验验证了本论文的结论。对于样机系统,考虑电枢绕组电阻影响可以使得充电电压和充电所需时间的仿真结果的误差大幅降低。 展开更多
关键词 换流角度 状态方程 感应子脉冲发电机 电容充电 平均值模型 电枢绕组电阻影响
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光伏发电系统PWM均值化实时仿真方法
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作者 匡维兴 徐涛 +3 位作者 蒋春红 郝正航 陈卓 熊国江 《实验室研究与探索》 北大核心 2025年第10期69-75,共7页
针对传统实时仿真在高频电力电子器件中计算效率低、资源占用高的问题,提出一种基于FPGA-UREP均值化原理的电磁暂态实时仿真方法。该方法使用FPGA_(1)并行生成高频PWM信号,并通过高速I/O接口传输至FPGA_(2)并采用均值化技术处理;UREP模... 针对传统实时仿真在高频电力电子器件中计算效率低、资源占用高的问题,提出一种基于FPGA-UREP均值化原理的电磁暂态实时仿真方法。该方法使用FPGA_(1)并行生成高频PWM信号,并通过高速I/O接口传输至FPGA_(2)并采用均值化技术处理;UREP模块负责光伏阵列、电网及控制模块的大步长(50μs)仿真,并与FPGA通过UDP高速通信实现数据交互。在光照突变和a相短路故障2种场景下的实验表明,该方法的实时仿真与Simulink离线仿真所得的交流电流、直流电压及输出功率高度吻合。该方法在保留PWM动态特性的同时,显著提高了仿真效率并降低了FPGA资源占用,可为新能源并网系统实时仿真提供参考。 展开更多
关键词 PWM均值化 平均模型 光伏发电系统 电磁暂态仿真 现场可编程门阵列
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基于TSA-WT-SVD的汽车转向助力泵转子裂纹声发射检测研究
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作者 金丹 裘杭锋 +2 位作者 刘冬 方赛银 李明 《测控技术》 2025年第2期32-38,共7页
针对现有磁粉探伤在汽车转向助力泵转子裂纹检测方面存在主观性强和漏检率高的问题,提出一种基于声发射(Acoustic Emission, AE)技术的转子裂纹缺陷在线无损检测方法。首先,在同一型号的双作用叶片泵的定子内先后装配带有裂纹缺陷和无... 针对现有磁粉探伤在汽车转向助力泵转子裂纹检测方面存在主观性强和漏检率高的问题,提出一种基于声发射(Acoustic Emission, AE)技术的转子裂纹缺陷在线无损检测方法。首先,在同一型号的双作用叶片泵的定子内先后装配带有裂纹缺陷和无缺陷的2种转子,在液压试验台上以1 000 r/min和14 MPa的加载参数进行满载试验,并且在泵体上的4个不同位置放置AE传感器,信号采样速率设置为3 MHz。然后,针对2种转子下采集的AE信号,分别按照100 ms时长从每个通道的原始信号中任意截取20个片段。针对每个AE片段,先采用时域同步平均(Time Domain Synchronous Averaging, TSA)算法提高信噪比,接着进行5层小波分解以获取AE信号在不同频段上的特征波形,再对5个细节信号组成的矩阵进行奇异值分解(Singular Value Decomposition, SVD),并以前5个奇异值作为标准特征。最后,针对转子有缺陷和无缺陷这2种情况,分别计算每个AE片段的奇异值向量与标准特征矩阵的马氏距离,并以最小距离作为分类依据。研究结果表明,当AE传感器布置在出油口附近时,所提出的TSA-WT-SVD方法辨识转子裂纹的准确率在95%以上。 展开更多
关键词 声发射 裂纹缺陷 域同步平均技术 小波分解 奇异值分解 马氏判别
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