期刊文献+
共找到32,080篇文章
< 1 2 250 >
每页显示 20 50 100
A high entropy stabilized perovskite oxide La_(0.2)Pr_(0.2)Sm_(0.2)Gd_(0.2)Sr_(0.2)Co_(0.8)Fe_(0.2)O_(3−δ)as a promising air electrode for reversible solid oxide cells 被引量:1
1
作者 LI Ruoyu LI Xiaoyu +2 位作者 ZHANG Jinke GAO Yuan LING Yihan 《燃料化学学报(中英文)》 北大核心 2025年第2期282-290,共9页
Reversible solid oxide cell(RSOC)is a new energy conversion device with significant applications,especially for power grid peaking shaving.However,the reversible conversion process of power generation/energy storage p... Reversible solid oxide cell(RSOC)is a new energy conversion device with significant applications,especially for power grid peaking shaving.However,the reversible conversion process of power generation/energy storage poses challenges for the performance and stability of air electrodes.In this work,a novel high-entropy perovskite oxide La_(0.2)Pr_(0.2)Gd_(0.2)Sm_(0.2)Sr_(0.2)Co_(0.8)Fe_(0.2)O_(3−δ)(HE-LSCF)is proposed and investigated as an air electrode in RSOC.The electrochemical behavior of HE-LSCF was studied as an air electrode in both fuel cell and electrolysis modes.The polarization impedance(Rp)of the HE-LSCF electrode is only 0.25Ω·cm^(2) at 800℃ in an air atmosphere.Notably,at an electrolytic voltage of 2 V and a temperature of 800℃,the current density reaches up to 1.68 A/cm^(2).The HE-LSCF air electrode exhibited excellent reversibility and stability,and its electrochemical performance remains stable after 100 h of reversible operation.With these advantages,HE-LSCF is shown to be an excellent air electrode for RSOC. 展开更多
关键词 reversible solid oxide cell high entropy stabilized perovskite air electrode electrochemical performance
在线阅读 下载PDF
Combing the Entropy Weight Method with Fuzzy Mathematics for Assessing the Quality and Post-Ripening Mechanism of High-Temperature Daqu during Storage
2
作者 YANG Junlin YANG Shaojuan +8 位作者 WU Cheng YIN Yanshun YOU Xiaolong ZHAO Wenyu ZHU Anran WANG Jia HU Feng HU Jianfeng WANG Diqiang 《食品科学》 北大核心 2025年第9期48-62,共15页
This study investigated the physicochemical properties,enzyme activities,volatile flavor components,microbial communities,and sensory evaluation of high-temperature Daqu(HTD)during the maturation process,and a standar... This study investigated the physicochemical properties,enzyme activities,volatile flavor components,microbial communities,and sensory evaluation of high-temperature Daqu(HTD)during the maturation process,and a standard system was established for comprehensive quality evaluation of HTD.There were obvious changes in the physicochemical properties,enzyme activities,and volatile flavor components at different storage periods,which affected the sensory evaluation of HTD to a certain extent.The results of high-throughput sequencing revealed significant microbial diversity,and showed that the bacterial community changed significantly more than did the fungal community.During the storage process,the dominant bacterial genera were Kroppenstedtia and Thermoascus.The correlation between dominant microorganisms and quality indicators highlighted their role in HTD quality.Lactococcus,Candida,Pichia,Paecilomyces,and protease activity played a crucial role in the formation of isovaleraldehyde.Acidic protease activity had the greatest impact on the microbial community.Moisture promoted isobutyric acid generation.Furthermore,the comprehensive quality evaluation standard system was established by the entropy weight method combined with multi-factor fuzzy mathematics.Consequently,this study provides innovative insights for comprehensive quality evaluation of HTD during storage and establishes a groundwork for scientific and rational storage of HTD and quality control of sauce-flavor Baijiu. 展开更多
关键词 microbial community high-temperature Daqu comprehensive quality evaluation entropy weight method maturation process
在线阅读 下载PDF
Delay bounded routing with the maximum belief degree for dynamic uncertain networks
3
作者 MA Ji KANG Rui +3 位作者 LI Ruiying ZHANG Qingyuan LIU Liang WANG Xuewang 《Journal of Systems Engineering and Electronics》 2025年第1期127-138,共12页
Delay aware routing is now widely used to provide efficient network transmission. However, for newly developing or developed mobile communication networks(MCN), only limited delay data can be obtained. In such a netwo... Delay aware routing is now widely used to provide efficient network transmission. However, for newly developing or developed mobile communication networks(MCN), only limited delay data can be obtained. In such a network, the delay is with epistemic uncertainty, which makes the traditional routing scheme based on deterministic theory or probability theory not applicable. Motivated by this problem, the MCN with epistemic uncertainty is first summarized as a dynamic uncertain network based on uncertainty theory, which is widely applied to model epistemic uncertainties. Then by modeling the uncertain end-toend delay, a new delay bounded routing scheme is proposed to find the path with the maximum belief degree that satisfies the delay threshold for the dynamic uncertain network. Finally, a lowEarth-orbit satellite communication network(LEO-SCN) is used as a case to verify the effectiveness of our routing scheme. It is first modeled as a dynamic uncertain network, and then the delay bounded paths with the maximum belief degree are computed and compared under different delay thresholds. 展开更多
关键词 dynamic uncertain network uncertainty theory epistemic uncertainty delay bounded routing maximum belief degree
在线阅读 下载PDF
Research on wear state prediction of ball end milling cutter based on entropy measurement of tool mark texture images
4
作者 LI Mao-yue LU Xin-yuan +1 位作者 LIU Ze-long ZHANG Ming-lei 《Journal of Central South University》 2025年第1期174-188,共15页
Efficient tool condition monitoring techniques help to realize intelligent management of tool life and reduce tool usage costs.In this paper,the influence of different wear degrees of ball-end milling cutters on the t... Efficient tool condition monitoring techniques help to realize intelligent management of tool life and reduce tool usage costs.In this paper,the influence of different wear degrees of ball-end milling cutters on the texture shape of machining tool marks is investigated,and a method is proposed for predicting the wear state(including the position and degree of tool wear)of ball-end milling cutters based on entropy measurement of tool mark texture images.Firstly,data samples are prepared through wear experiments,and the change law of the tool mark texture shape with the tool wear state is analyzed.Then,a two-dimensional sample entropy algorithm is developed to quantify the texture morphology.Finally,the processing parameters and tool attitude are integrated into the prediction process to predict the wear value and wear position of the ball end milling cutter.After testing,the correlation between the predicted value and the standard value of the proposed tool condition monitoring method reaches 95.32%,and the accuracy reaches 82.73%,indicating that the proposed method meets the requirement of tool condition monitoring. 展开更多
关键词 ball-end cutter wear tool condition monitoring surface texture texture quantifier sample entropy
在线阅读 下载PDF
Design and optimization of the RGB beam combiner in micro display using entropy weight-TOPSIS method
5
作者 ZHENG Yu ZHAO Yan-bing +4 位作者 ZOU Xin-jie WANG Ji-rong JIANG Xiang LIU Jian-zhe DUAN Ji-an 《Journal of Central South University》 2025年第2期483-494,共12页
Red-green-blue(RGB)beam combiners are widely used in scenarios such as augmented reality/virtual reality(AR/VR),laser projection,biochemical detection,and other fields.Optical waveguide combiners have attracted extens... Red-green-blue(RGB)beam combiners are widely used in scenarios such as augmented reality/virtual reality(AR/VR),laser projection,biochemical detection,and other fields.Optical waveguide combiners have attracted extensive attention due to their advantages of small size,high multiplexing efficiency,convenient mass production,and low cost.An RGB beam combiner based on directional couplers is designed,with a core-cladding relative refractive index difference of 0.75%.The RGB beam combiner is optimized from the perspective of parameter optimization.Using the beam propagation method(BPM),the relationship between the performance of the RGB beam combiner and individual parameters is studied,achieving preliminary optimization of the device’s performance.The key parameters of the RGB beam combiner are optimized using the entropy weight-technique for order preference by similarity to an ideal solution TOPSIS method,establishing the optimal parameter scheme and further improving the device’s performance indicators.The results show that after optimization,the multiplexing efficiencies for red,green,and blue lights,as well as the average multiplexing efficiency,reached 99.17%,99.76%,96.63%and 98.52%,respectively.The size of the RGB beam combiner is 4.768 mm×0.062 mm. 展开更多
关键词 optical waveguide combiners red-green-blue beam combiner beam propagation method entropy weight TOPSIS method multiplexing efficiency
在线阅读 下载PDF
A modified method to calculate reliability index using maximum entropy principle 被引量:3
6
作者 徐志军 郑俊杰 +1 位作者 边晓亚 刘勇 《Journal of Central South University》 SCIE EI CAS 2013年第4期1058-1063,共6页
Routine reliability index method, first order second moment (FOSM), may not ensure convergence of iteration when the performance function is strongly nonlinear. A modified method was proposed to calculate reliability ... Routine reliability index method, first order second moment (FOSM), may not ensure convergence of iteration when the performance function is strongly nonlinear. A modified method was proposed to calculate reliability index based on maximum entropy (MaxEnt) principle. To achieve this goal, the complicated iteration of first order second moment (FOSM) method was replaced by the calculation of entropy density function. Local convergence of Newton iteration method utilized to calculate entropy density function was proved, which ensured the convergence of iteration when calculating reliability index. To promote calculation efficiency, Newton down-hill algorithm was incorporated into calculating entropy density function and Monte Carlo simulations (MCS) were performed to assess the efficiency of the presented method. Two numerical examples were presented to verify the validation of the presented method. Moreover, the execution and advantages of the presented method were explained. From Example 1, after seven times iteration, the proposed method is capable of calculating the reliability index when the performance function is strongly nonlinear and at the same time the proposed method can preserve the calculation accuracy; From Example 2, the reliability indices calculated using the proposed method, FOSM and MCS are 3.823 9, 3.813 0 and 3.827 6, respectively, and the according iteration times are 5, 36 and 10 6 , which shows that the presented method can improve calculation accuracy without increasing computational cost for the performance function of which the reliability index can be calculated using first order second moment (FOSM) method. 展开更多
关键词 reliability index maximum entropy principle first order second moment Newton iteration Monte Carlo simulation
在线阅读 下载PDF
A critical review on solid-state welding of high entropy alloys-processing,microstructural characteristics and mechanical properties of joints 被引量:1
7
作者 Tushar Sonar Mikhail Ivanov +2 位作者 Evgeny Trofimov Aleksandr Tingaev Ilsiya Suleymanova 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第4期78-133,共56页
The high entropy alloys(HEAs)are the newly developed high-performance materials that have gained significant importance in defence,nuclear and aerospace sector due to their superior mechanical properties,heat resistan... The high entropy alloys(HEAs)are the newly developed high-performance materials that have gained significant importance in defence,nuclear and aerospace sector due to their superior mechanical properties,heat resistance,high temperature strength and corrosion resistance.These alloys are manufactured by the equal mixing or larger proportions of five or more alloying elements.HEAs exhibit superior mechanical performance compared to traditional engineering alloys because of the extensive alloying composition and higher entropy of mixing.Solid state welding(SSW)techniques such as friction stir welding(FSW),rotary friction welding(RFW),diffusion bonding(DB)and explosive welding(EW)have been efficiently deployed for improving the microstructural integrity and mechanical properties of welded HEA joints.The HEA interlayers revealed greater potential in supressing the formation of deleterious intermetallic phases and maximizing the mechanical properties of HEAs joints.The similar and dissimilar joining of HEAs has been manifested to be viable for HEA systems which further expands their industrial applications.Thus,the main objective of this review paper is to present a critical review of current state of research,challenges and opportunities and main directions in SSW of HEAs mainly CoCrFeNiMn and Al_xCoCrFeNi alloys.The state of the art of problems,progress and future outlook in SSW of HEAs are critically reviewed by considering the formation of phases,microstructural evolution and mechanical properties of HEAs joints. 展开更多
关键词 High entropy alloys Solid state welding MICROSTRUCTURE Mechanical properties
在线阅读 下载PDF
Detection method of forward-scatter signal based on Rényi entropy 被引量:2
8
作者 ZHENG Yuqing AI Xiaofeng +2 位作者 YANG Yong ZHAO Feng XIAO Shunping 《Journal of Systems Engineering and Electronics》 SCIE CSCD 2024年第4期865-873,共9页
The application scope of the forward scatter radar(FSR)based on the Global Navigation Satellite System(GNSS)can be expanded by improving the detection capability.Firstly,the forward-scatter signal model when the targe... The application scope of the forward scatter radar(FSR)based on the Global Navigation Satellite System(GNSS)can be expanded by improving the detection capability.Firstly,the forward-scatter signal model when the target crosses the baseline is constructed.Then,the detection method of the for-ward-scatter signal based on the Rényi entropy of time-fre-quency distribution is proposed and the detection performance with different time-frequency distributions is compared.Simula-tion results show that the method based on the smooth pseudo Wigner-Ville distribution(SPWVD)can achieve the best perfor-mance.Next,combined with the geometry of FSR,the influence on detection performance of the relative distance between the target and the baseline is analyzed.Finally,the proposed method is validated by the anechoic chamber measurements and the results show that the detection ability has a 10 dB improvement compared with the common constant false alarm rate(CFAR)detection. 展开更多
关键词 forward scatter radar(FSR) Global Navigation Satellite System(GNSS) time-frequency distribution Rényi entropy signal detection
在线阅读 下载PDF
Beamspace maximum likelihood algorithm based on sum and difference beams for elevation estimation
9
作者 CHEN Sheng ZHAO Yongbo +1 位作者 HU Yili PANG Xiaojiao 《Journal of Systems Engineering and Electronics》 SCIE CSCD 2024年第3期589-598,共10页
Beamspace super-resolution methods for elevation estimation in multipath environment has attracted significant attention, especially the beamspace maximum likelihood(BML)algorithm. However, the difference beam is rare... Beamspace super-resolution methods for elevation estimation in multipath environment has attracted significant attention, especially the beamspace maximum likelihood(BML)algorithm. However, the difference beam is rarely used in superresolution methods, especially in low elevation estimation. The target airspace information in the difference beam is different from the target airspace information in the sum beam. And the use of difference beams does not significantly increase the complexity of the system and algorithms. Thus, this paper applies the difference beam to the beamformer to improve the elevation estimation performance of BML algorithm. And the direction and number of beams can be adjusted according to the actual needs. The theoretical target elevation angle root means square error(RMSE) and the computational complexity of the proposed algorithms are analyzed. Finally, computer simulations and real data processing results demonstrate the effectiveness of the proposed algorithms. 展开更多
关键词 elevation estimation BEAMSPACE multipath environment maximum likelihood
在线阅读 下载PDF
Composition optimization and performance prediction for ultra-stable water-based aerosol based on thermodynamic entropy theory
10
作者 Tingting Kang Canjun Yan +6 位作者 Xinying Zhao Jingru Zhao Zixin Liu Chenggong Ju Xinyue Zhang Yun Zhang Yan Wu 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第3期437-446,共10页
Water-based aerosol is widely used as an effective strategy in electro-optical countermeasure on the battlefield used to the preponderance of high efficiency,low cost and eco-friendly.Unfortunately,the stability of th... Water-based aerosol is widely used as an effective strategy in electro-optical countermeasure on the battlefield used to the preponderance of high efficiency,low cost and eco-friendly.Unfortunately,the stability of the water-based aerosol is always unsatisfactory due to the rapid evaporation and sedimentation of the aerosol droplets.Great efforts have been devoted to improve the stability of water-based aerosol by using additives with different composition and proportion.However,the lack of the criterion and principle for screening the effective additives results in excessive experimental time consumption and cost.And the stabilization time of the aerosol is still only 30 min,which could not meet the requirements of the perdurable interference.Herein,to improve the stability of water-based aerosol and optimize the complex formulation efficiently,a theoretical calculation method based on thermodynamic entropy theory is proposed.All the factors that influence the shielding effect,including polyol,stabilizer,propellant,water and cosolvent,are considered within calculation.An ultra-stable water-based aerosol with long duration over 120 min is obtained with the optimal fogging agent composition,providing enough time for fighting the electro-optic weapon.Theoretical design guideline for choosing the additives with high phase transition temperature and low phase transition enthalpy is also proposed,which greatly improves the total entropy change and reduce the absolute entropy change of the aerosol cooling process,and gives rise to an enhanced stability of the water-based aerosol.The theoretical calculation methodology contributes to an abstemious time and space for sieving the water-based aerosol with desirable performance and stability,and provides the powerful guarantee to the homeland security. 展开更多
关键词 Ultra-stable Water-based aerosol Thermodynamic entropy Composition optimization Performance prediction
在线阅读 下载PDF
Kernel- based Maximum Entropy Clustering
11
作者 JIANG Wei QU Jiao LI Benxi 《现代电子技术》 2007年第2期152-153,156,共3页
在线阅读 下载PDF
考虑地震需求统计不确定性的地铁车站结构地震易损性分析 被引量:1
12
作者 崔春义 许民泽 +3 位作者 许成顺 赵经彤 刘海龙 孟坤 《岩土工程学报》 北大核心 2025年第3期453-462,共10页
为避免非完备地震需求样本集所导致的地铁车站结构地震易损性分析认知不确定性,提出了一种可考虑地震需求统计不确定性的地铁车站结构地震易损性分析方法。首先,基于Bootstrap法将有限地震需求样本问题转换为大样本问题;其次,结合最大... 为避免非完备地震需求样本集所导致的地铁车站结构地震易损性分析认知不确定性,提出了一种可考虑地震需求统计不确定性的地铁车站结构地震易损性分析方法。首先,基于Bootstrap法将有限地震需求样本问题转换为大样本问题;其次,结合最大熵原理和Copula理论构建统计不确定性变量的联合概率分布模型;在此基础上,进一步量化由地震需求统计不确定性所导致的地震易损性水平变异性,并求解得出均值地震易损性曲线以及对应一定置信度的包络地震易损性曲线;最后,以大开地铁车站为具体对象,系统分析了地震需求统计不确定性的影响规律。研究表明:在有限地震需求样本条件下地铁车站结构地震易损性水平具有显著的变异性,且该变异性会随着地震动强度的增加呈现出先增大后减小的变化趋势;均值与包络易损性曲线可有效考虑基于有限地震需求样本的地铁车站结构地震易损性不确定性程度,且具有良好可信度。所提出的相关分析方法和结论可为地铁车站结构抗震性能和地震风险评估提供参考和指导作用。 展开更多
关键词 地铁车站结构 地震易损性 认知不确定性 BOOTSTRAP法 最大熵原理
在线阅读 下载PDF
Application of optimized random forest regressors in predicting maximum principal stress of aseismic tunnel lining
13
作者 MEI Xian-cheng DING Chang-dong +4 位作者 ZHANG Jia-min LI Chuan-qi CUI Zhen SHENG Qian CHEN Jian 《Journal of Central South University》 CSCD 2024年第11期3900-3913,共14页
Using flexible damping technology to improve tunnel lining structure is an emerging method to resist earthquake disasters,and several methods have been explored to predict mechanical response of tunnel lining with dam... Using flexible damping technology to improve tunnel lining structure is an emerging method to resist earthquake disasters,and several methods have been explored to predict mechanical response of tunnel lining with damping layer.However,the traditional numerical methods suffer from the complex modelling and time-consuming problems.Therefore,a prediction model named the random forest regressor(RFR)is proposed based on 240 numerical simulation results of the mechanical response of tunnel lining.In addition,circle mapping(CM)is used to improve Archimedes optimization algorithm(AOA),reptile search algorithm(RSA),and Chernobyl disaster optimizer(CDO)to further improve the predictive performance of the RFR model.The performance evaluation results show that the CMRSA-RFR is the best prediction model.The damping layer thickness is the most important feature for predicting the maximum principal stress of tunnel lining containing damping layer.This study verifies the feasibility of combining numerical simulation with machine learning technology,and provides a new solution for predicting the mechanical response of aseismic tunnel with damping layer. 展开更多
关键词 maximum principal stress aseismic tunnel lining random forest regressor machine learning
在线阅读 下载PDF
基于FAHP-Entropy赋权法的矿山地质环境影响评价:以武鸣区灰岩矿山为例 被引量:1
14
作者 全毅博 甘能俭 +3 位作者 伍静 朱敏杰 吕堂安 李志 《中国矿业》 北大核心 2024年第2期53-62,共10页
矿山地质环境影响评价是一个兼具复杂性和模糊性的系统,是将有限的修复资源如何合理地分配到不同影响程度矿山的科学依据。为了更精准、更高效地评价矿山对周边地质环境的影响状况及程度,本文选择南宁市武鸣区38个灰岩矿山为研究对象,... 矿山地质环境影响评价是一个兼具复杂性和模糊性的系统,是将有限的修复资源如何合理地分配到不同影响程度矿山的科学依据。为了更精准、更高效地评价矿山对周边地质环境的影响状况及程度,本文选择南宁市武鸣区38个灰岩矿山为研究对象,从地质环境背景、资源破坏、地质灾害、矿山开发利用状况4个方面选取了14个评价指标构建矿山地质环境影响评价体系,采用模糊层次分析法和熵值法相结合(FAHP-Entropy组合)赋权法综合评价矿山地质环境影响程度,并基于MATLAB平台开发了矿山地质环境影响评价系统(MGES),对38座灰岩矿山进行评价。评价结果显示,对地质环境影响较轻的矿山仅占比21%,对地质环境影响较严重的矿山占比47%,对地质环境影响严重的矿山占比32%,武鸣区矿山地质环境影响程度整体属较严重~严重级别。研究结果为武鸣区政府有限的治理资金指明了优先治理方向。该系统操作简单,可以弥补传统方法复杂、难操作的不足之处,对于处理大规模数据有极大优势,可为同业技术人员和学者开展矿山地质环境影响评价工作提供借鉴。 展开更多
关键词 矿山地质环境 FAHP-entropy赋权法 灰岩矿山 地质环境影响评价 评价系统
在线阅读 下载PDF
高强钢商用车油箱托架热冲压成形工艺研究 被引量:2
15
作者 徐勇 陈明 +2 位作者 贾国富 解文龙 张士宏 《塑性工程学报》 北大核心 2025年第1期30-40,共11页
为获得具有大弯曲特征的高强钢商用车油箱托架热冲压成形的最佳工艺参数,首先通过有限元模拟分析了摩擦因数、初始温度和成形速度3个成形工艺参数对托架壁厚和最大减薄率的影响。然后,通过正交试验和极差分析法,获得影响零件热冲压成形... 为获得具有大弯曲特征的高强钢商用车油箱托架热冲压成形的最佳工艺参数,首先通过有限元模拟分析了摩擦因数、初始温度和成形速度3个成形工艺参数对托架壁厚和最大减薄率的影响。然后,通过正交试验和极差分析法,获得影响零件热冲压成形质量的主次因素和热冲压最佳工艺参数。结果表明,零件最大减薄率随初始温度的升高而降低;随摩擦因数和成形速度的增大而增大。正交试验结果表明,摩擦因数对最大减薄率的影响程度最大,其次是初始温度,成形速度的影响最小。在初始温度为920℃、摩擦因数为0.25、成形速度为30 mm·s^(-1)的参数组合下,零件的最大减薄率为12.3%。试验获得零件的最大减薄率为10.1%,从零件上取样进行拉伸得到抗拉强度均大于1500 MPa,平均硬度达到467.33 HV,显微组织为马氏体和残余奥氏体。试验结果表明有限元模拟的预测误差较小,零件无明显缺陷,并获得了最佳成形工艺参数。 展开更多
关键词 油箱托架 热冲压成形 最大减薄率
在线阅读 下载PDF
采用广义混合最大相关熵准则扩展卡尔曼滤波算法的锂离子电池荷电状态估计
16
作者 巫春玲 赵玉冰 +3 位作者 耿莉敏 徐先峰 王溢波 陈昊 《西安交通大学学报》 北大核心 2025年第7期159-169,共11页
为了解决非高斯噪声环境下荷电状态(SOC)估计不准确以及鲁棒性差等问题,提出一种基于广义混合最大相关熵准则的扩展卡尔曼滤波(GMMCC-EKF)算法。该算法利用两个广义高斯函数构成的核函数得到广义混合熵,继承了广义高斯核的灵活性,并通... 为了解决非高斯噪声环境下荷电状态(SOC)估计不准确以及鲁棒性差等问题,提出一种基于广义混合最大相关熵准则的扩展卡尔曼滤波(GMMCC-EKF)算法。该算法利用两个广义高斯函数构成的核函数得到广义混合熵,继承了广义高斯核的灵活性,并通过统计线性化技术将状态误差和测量误差统一纳入代价函数,进而通过固定点迭代法获得非线性方程的最优估计,然后将广义混合最大相关熵准则与扩展卡尔曼滤波相结合,增强在非高斯噪声环境下的稳定性,提高对复杂数据处理的准确性。为了验证算法有效性,分别选用两种不同类型的锂离子电池,在动态应力测试(DST)工况及多种环境温度(10、25和40℃)的新欧洲驾驶循环(NEDC)工况下对电池进行SOC估计。实验结果表明,在25℃且均匀混合噪声环境下,对于1号电池,GMMCC-EKF算法的估计精度相对于扩展卡尔曼滤波算法(EKF)和传统最大相关熵扩展卡尔曼滤波算法(MCC-EKF)分别提高了90.1%和83.9%;对于2号电池,估计精度分别提高了72.4%和47.4%,并且在10、40℃环境下该算法仍展现出最优性能。对1号、2号电池在25℃且拉普拉斯混合噪声环境下进行SOC估计,GMMCC-EKF算法相对于其他两种算法的估计精度也有显著提高。在给定初始值错误的情况下,GMMCC-EKF算法能够快速地收敛到真实值。所提算法具有较高的估计精度、良好的适应性和鲁棒性,可为非高斯噪声环境下的SOC估计提供有效解决方案。 展开更多
关键词 荷电状态估计 广义混合最大相关熵准则 扩展卡尔曼滤波 非高斯噪声
在线阅读 下载PDF
基于最大信息系数法的卧沙溪滑坡变形相关性分析及预警模型研究 被引量:2
17
作者 尚敏 王殿鹏 +2 位作者 易庆林 袁朔 宋云鹏 《工程地质学报》 北大核心 2025年第2期572-580,共9页
本篇以三峡库区卧沙溪滑坡为研究对象,运用最大信息量法对滑坡变形影响因素相关性进行了定量分析。结果表明降雨是坡体加速变形的主要诱因,库水位变化仅起到加速滑坡变形的作用,而非既有研究认为的动水压力型滑坡。为提升滑坡预警和预... 本篇以三峡库区卧沙溪滑坡为研究对象,运用最大信息量法对滑坡变形影响因素相关性进行了定量分析。结果表明降雨是坡体加速变形的主要诱因,库水位变化仅起到加速滑坡变形的作用,而非既有研究认为的动水压力型滑坡。为提升滑坡预警和预测的准确度,采用了最大信息系数法(MIC)与改进的切线角法,对近8年来滑坡次级滑体发生的4次阶跃变形进行了分析,确定了引发这些阶跃变形的降雨阈值和位移速率阈值。基于这些阈值,建立了一个更加完善的新型预警模型。研究结果不仅有助于提升对卧沙溪滑坡的监测水平,也为类似地质灾害的监测预警提供了有价值的参考。 展开更多
关键词 卧沙溪滑坡 定量分析 最大信息系数 预警模型
在线阅读 下载PDF
基于优化MaxEnt模型的怒江州滑坡易发性评价
18
作者 李益敏 向倩英 +1 位作者 邓选伦 冯显杰 《河南理工大学学报(自然科学版)》 CAS 北大核心 2025年第1期57-67,共11页
目的 怒江州是典型的高山峡谷地区,地质灾害(滑坡)频发,严重制约着当地的发展。为解决这一问题,方法 综合考虑怒江州实际情况,从气象水文、地形地貌、地层岩性、植被生态和人类活动5个方面选取坡向,高程等14个影响因子,判断滑坡与各影... 目的 怒江州是典型的高山峡谷地区,地质灾害(滑坡)频发,严重制约着当地的发展。为解决这一问题,方法 综合考虑怒江州实际情况,从气象水文、地形地貌、地层岩性、植被生态和人类活动5个方面选取坡向,高程等14个影响因子,判断滑坡与各影响因子间相关性,构建评价指标体系,对最大熵(maximum entropy, MaxEnt)模型的特征类(feature combination,FC)和正则化乘数(regularization multiplier, RM)参数进行优化,对比优化前后小样本赤池信息量准则(akaikeinformationcriterion,AIC)、遗漏率(omissionrate,OR)和AUC(areaunder curve),并基于优化的MaxEnt模型预测滑坡灾害的发生,实现怒江州滑坡易发性评价。结果结果表明:优化后的MaxEnt模型在研究区滑坡易发性预测中适用性优秀(AUC=0.913);运用刀切法(Jackknife)计算各影响因子对易发性的影响程度,高程(S3, 23.2%)、坡度(S9, 22.4%)、居民点密度(S5, 14.2%)、距河流距离(S13, 13.7%)、距道路距离(S4, 9.6%)和岩性(S7, 8.7%)是前六位影响因子,累计贡献度达91.8%;极高、高、中、低滑坡易发性等级的空间占比分别为4.88%,8.96%,18.40%,67.76%,县域中极高和高易发区占比最大的是泸水市,整体上看,极高、高易发区主要沿河流和道路分布于峡谷中,低易发区主要分布于人类活动少、河谷不发育的区域。结论 优化后的MaxEnt模型更适合怒江州滑坡易发性预测,研究结果可为怒江州防灾减灾与土地利用规划提供参考。 展开更多
关键词 怒江州 最大熵模型 滑坡 易发性
在线阅读 下载PDF
基于强化学习的宽速域冲压发动机燃烧室一维压力分布控制方法研究
19
作者 聂聆聪 牟春晖 李帅衡 《推进技术》 北大核心 2025年第6期230-240,共11页
为提高冲压发动机燃烧室在宽速域范围内的性能,提出一种基于系数自适应调整熵正则化强化学习的宽速域几何可调燃烧室压力分布的控制方法,通过对燃烧室在一维流场上的压力分布监测与控制,实现该类燃烧室的宽速域高性能燃烧。本文采用熵... 为提高冲压发动机燃烧室在宽速域范围内的性能,提出一种基于系数自适应调整熵正则化强化学习的宽速域几何可调燃烧室压力分布的控制方法,通过对燃烧室在一维流场上的压力分布监测与控制,实现该类燃烧室的宽速域高性能燃烧。本文采用熵正则化强化学习方法,利用滑块位移、两个喷注流量,实现对燃烧室沿程压力一维分布形状的优化控制;提出适用燃烧室多压力点控制的自适应温度系数调整算法,提高对压力分布一维控制算法的训练收敛速度,同时建立适用于一维压力分布控制的动作抖动惩罚函数及随机训练策略,解决了执行机构抖动、算法的泛化性及延时鲁棒性差等问题;通过数值仿真验证了算法的有效性,结果表明压力分布控制均方误差最大1.44%,超调量最大2.76%,调节时间不超过0.5 s,符合工程实际应用需求。 展开更多
关键词 冲压发动机 宽速域燃烧室 压力控制 强化学习 最大熵正则化
在线阅读 下载PDF
一种适用于风储微电网的混合储能系统的功率分配策略 被引量:2
20
作者 李艳波 杨凯 +3 位作者 陈俊硕 姚博彬 刘维宇 武奇生 《电测与仪表》 北大核心 2025年第2期43-50,共8页
混合储能系统是微电网的重要组成部分之一,研究其功率分配策略对电池的保护具有重要意义。在由超级电容-蓄电池组成的混合储能系统的基础上,提出互补集合经验模态分解的方法来平抑风力发电不稳定性而引起的功率波动。针对风力发电的波... 混合储能系统是微电网的重要组成部分之一,研究其功率分配策略对电池的保护具有重要意义。在由超级电容-蓄电池组成的混合储能系统的基础上,提出互补集合经验模态分解的方法来平抑风力发电不稳定性而引起的功率波动。针对风力发电的波动性及不确定性,互补集合经验模态分解法能够把风电原始能量信号分解为固有模态分量和余量,通过能量熵理论求出功率一次分配分界点,即初始功率分配;提出利用模糊控制对混合储能系统的荷电状态进行优化约束,自适应调整并修正混合储能系统功率分配指令。利用MATLAB程序及Simulink仿真模型并结合算例分析,结果说明了提出的策略可以使蓄电池SOC波动不超过8%,超级电容SOC波动不超过10%,有效提高了整个系统的工作效率和使用寿命。 展开更多
关键词 互补集合经验模态分解法 模糊控制 荷电状态 能量熵
在线阅读 下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部