期刊文献+
共找到127篇文章
< 1 2 7 >
每页显示 20 50 100
Using Entropy Based Mean Shift Filter and Modified Watershed Transform for Grain Segmentation 被引量:2
1
作者 Kun Zhang Min-Rui Fei Hui-Yu Zhou 《International Journal of Automation and computing》 EI CSCD 2015年第2期199-207,共9页
Life science research aims to continuously improve the quality and standard of human life. One of the major challenges in this area is to maintain food safety and security. A number of image processing techniques have... Life science research aims to continuously improve the quality and standard of human life. One of the major challenges in this area is to maintain food safety and security. A number of image processing techniques have been used to investigate the quality of food products. In this paper, we propose a new algorithm to effectively segment connected grains so that each of them can be inspected in a later processing stage. One family of the existing segmentation methods is based on the idea of watersheding, and it has shown promising results in practice. However, due to the over-segmentation issue, this technique has experienced poor performance in various applications, such as inhomogeneous background and connected targets. To solve this problem, we present a combination of two classical techniques to handle this issue. In the first step, a mean shift filter is used to eliminate the inhomogeneous background,where entropy is used to be a converging criterion. Secondly, a color gradient algorithm is used in order to detect the most significant edges, and a marked watershed transform is applied to segment cluttered objects out of the previous processing stages. The proposed framework is capable of compromising among execution time, usability, efficiency and segmentation outcome in analyzing ring die pellets. The experimental results demonstrate that the proposed approach is effectiveness and robust. 展开更多
关键词 Robust segmentation cluttered grains mean shift filter entropy modified marked watershed transform.
原文传递
Time Dependent Entropy and Decoherence in a Modified Quantum Damped Harmonic Oscillator
2
作者 F. B. Pelap A. Fomethe +1 位作者 A. J. Fotue M. P. Djemmo Tabue 《Journal of Quantum Information Science》 2014年第4期214-226,共13页
The time dependence of probability and Shannon entropy of a modified damped harmonic oscillator is studied by using single and double Gaussian wave functions through the Feynman path method. We establish that the damp... The time dependence of probability and Shannon entropy of a modified damped harmonic oscillator is studied by using single and double Gaussian wave functions through the Feynman path method. We establish that the damped coefficient as well as the system frequency and the distance separating two consecutive waves of the initial double Gaussian function influences the coherence of the system and can be used to control its decoherence. 展开更多
关键词 modified DAMPED Harmonic OSCILLATOR FEYNMAN Path Integral DECOHERENCE Shannon entropy Distribution Probability
在线阅读 下载PDF
Modified Newtonian Dynamics as an Entropic Force
3
作者 Diego A. Carranza Sergio Mendoza 《Journal of Modern Physics》 2015年第6期786-793,共8页
Under natural assumptions on the thermodynamic properties of space and time with the holo-graphic principle, we reproduce a MOND-like behaviour of gravity on particular scales of mass and length, where Newtonian gravi... Under natural assumptions on the thermodynamic properties of space and time with the holo-graphic principle, we reproduce a MOND-like behaviour of gravity on particular scales of mass and length, where Newtonian gravity requires a modification or extension if no dark matter component is introduced in the description of gravitational phenomena. The result is directly obtained with the assumption that a fundamental constant of nature with dimensions of acceleration needs to be introduced into gravitational interactions. This in turn allows for modifications or extensions of the equipartion law and/or the holographic principle. In other words, MOND-like phenomenology can be reproduced when appropriate generalised concepts at the thermodynamical level of space and/or at the holographic principle are introduced. Thermodynamical modifications are reflected in extensions to the equipartition law which occur when the temperature of the system drops below a critical value, equals to Unruh’s temperature evaluated at the acceleration constant scale introduced for the description of the gravitational phenomena. Our calculations extend the ones by [1] in which Newtonian gravity is shown to be an emergent phenomenon, and together with it reinforces the idea that gravity at all scales is emergent. 展开更多
关键词 Alternative Theories of GRAVITY modified NEWTONIAN Dynamics CLASSICAL BLACK HOLES entropy THERMODYNAMICS of BLACK HOLES
在线阅读 下载PDF
A Novel Modified Alpha Power Transformed Weibull Distribution and Its Engineering Applications
4
作者 Refah Alotaibi Hassan Okasha +1 位作者 Mazen Nassar Ahmed Elshahhat 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第6期2065-2089,共25页
This paper suggests a new modified version of the traditional Weibull distribution by adding a new shape parameter utilising the modified alpha power transformed technique.We refer to the new model as modified alpha p... This paper suggests a new modified version of the traditional Weibull distribution by adding a new shape parameter utilising the modified alpha power transformed technique.We refer to the new model as modified alpha power transformed Weibull distribution.The attractiveness and significance of the new distribution lie in its power to model monotone and non-monotone failure rate functions,which are quite familiar in environmental investigations.Its hazard rate function can be decreasing,increasing,bathtub and upside-down then bathtub shaped.Diverse structural properties of the proposed model are acquired including quantile function,moments,entropies,order statistics,residual life and reversed failure rate function.The parameters of the distribution were estimated using the maximum likelihood function.The maximum likelihood method is employed to estimate the model parameters and the approximate confidence intervals are also computed.Via a simulation study,the performance of the point and interval estimates are compared using different criteria.Employing real lifetime data sets,we verify that the offered model furnishes a better fit than some other lifetime models including Weibull,gamma and alpha powerWeibull models. 展开更多
关键词 Weibull distribution modified alpha power transformationmethod maximum likelihood entropy order statistics
在线阅读 下载PDF
Thermodynamic aspects of higher-dimensional black holes in Einstein-Gauss-Bonnet gravity through exponential entropy
5
作者 Sana Malik Abdul Jawad +3 位作者 Shahid Chaudhary Mohammad Mahtab Alam Sanjar Shaymatov Shamaila Rani 《Communications in Theoretical Physics》 2025年第4期129-150,共22页
We assume exponential corrections to the entropy of 5D charged Ad S black hole solutions,which are derived within the framework of Einstein-Gauss-Bonnet gravity and nonlinear electrodynamics.Additionally,we consider t... We assume exponential corrections to the entropy of 5D charged Ad S black hole solutions,which are derived within the framework of Einstein-Gauss-Bonnet gravity and nonlinear electrodynamics.Additionally,we consider two distinct versions of 5D charged Ad S black holes by setting the parameters q→0 and k→0(where q represents the charge,and k is the non-linear parameter).We investigate these black holes in the extended phase space,where the cosmological constant is interpreted as pressure,demonstrating the first law of black hole thermodynamics.The focus extends to understanding the thermal stability or instability,as well as identifying first and second-order phase transitions.This exploration is carried out through the analysis of various thermodynamic quantities,including heat capacity at constant pressure,Gibbs free energy(GFE),Helmholtz free energy(HFE),and the trace of the Hessian matrix.In order to visualize phase transitions,identify critical points,analyze stability and provide comprehensive analysis,we have made the contour plot of the mentioned thermodynamic quantities and observed that our results are very consistent.These investigations are conducted within the context of exponentially corrected entropies,providing valuable insights into the intricate thermodynamic behavior of these 5D charged Ad S black holes under different parameter limits. 展开更多
关键词 black hole thermodynamics thermodynamics quantities thermal stability higher dimensional Einstein-Gauss-Bonnet black hole modified entropy
原文传递
基于熵权TOPSIS-响应曲面法的路面冷拌料优化设计
6
作者 王伟明 吴旷怀 《交通科技》 2026年第1期21-26,共6页
为优化SBS复合改性乳化沥青冷拌料的路用性能,科学确定其最佳配比,解决传统配比设计的局限性,采用CAVF法设计矿料级配,基于响应曲面法的Box-Behnken原理,以乳液、液体及水泥用量为因素设计17组试验方案;通过修正马歇尔、车辙、低温弯曲... 为优化SBS复合改性乳化沥青冷拌料的路用性能,科学确定其最佳配比,解决传统配比设计的局限性,采用CAVF法设计矿料级配,基于响应曲面法的Box-Behnken原理,以乳液、液体及水泥用量为因素设计17组试验方案;通过修正马歇尔、车辙、低温弯曲及冻融劈裂试验获取关键性能指标;随后利用熵权TOPSIS模型将多指标转化为路用性能综合评价值,建立综合评价值与各因素的二次回归模型。结果表明,所建模型预测精准度高,优化得出的最佳配比为乳液用量9%、液体用量4%、水泥用量3%,此配比下综合评价值的预测值与实际值误差仅2.51%。构建的熵权TOPSIS-响应曲面法,能有效实现乳化沥青冷拌料多目标性能的综合评价与配比优化,为路面冷拌料材料设计与工程应用提供参考。 展开更多
关键词 路面冷拌料 SBS复合改性乳化沥青 配合比 熵权TOPSIS 响应曲面法
在线阅读 下载PDF
聚合物改性剂和纤维类型对微表处沥青混合料路用性能的影响研究
7
作者 曾迪 宋小金 《公路交通技术》 2026年第1期35-41,共7页
为提高微表处沥青混合料的综合路用性能,采用水性聚氨酯、水性环氧树脂等聚合物和聚酯纤维、聚丙烯纤维、玄武岩纤维等纤维复合改性的方法,对提升微表处沥青混合料的综合路用性能进行研究。结果表明:1)聚合物改性纤维微表处沥青混合料... 为提高微表处沥青混合料的综合路用性能,采用水性聚氨酯、水性环氧树脂等聚合物和聚酯纤维、聚丙烯纤维、玄武岩纤维等纤维复合改性的方法,对提升微表处沥青混合料的综合路用性能进行研究。结果表明:1)聚合物改性纤维微表处沥青混合料的最佳外掺水量和最佳油石比分别为8%和7.5%;2)水性环氧树脂+聚丙烯纤维的组合方案对抗拉拔强度贡献最大,而水性环氧树脂+玄武岩纤维的组合方案对抗变形能力贡献最大;3)在纤维同等条件下,水性环氧树脂与纤维组合的高温稳定性高于水性聚氨酯,而对于抗水损性能和低温抗裂性,水性聚氨酯与纤维的组合表现更佳;4)在聚合物改性剂同等条件下,聚丙烯纤维对抗水损性能改善最大,而玄武岩纤维对高温稳定性和低温抗裂性改善最大;5)掺入纤维可有效提高聚合物改性微表处混合料的抗滑性能和耐磨性能,其中玄武岩纤维表现突出;6)熵权TOPSIS法得到的相对贴近度排序结果与综合评价指标结论一致,水性环氧树脂+聚丙烯纤维的组合使微表处沥青混合料表现出最佳综合路用性能。 展开更多
关键词 道路工程 聚合物改性剂 纤维 微表处 沥青混合料 熵权TOPSIS方法 路用性能
在线阅读 下载PDF
Audit Risk Evaluation of the Medical CRO Industry:A Method Combining Entropy Weight-TOPSIS and Grey Relational Degree
8
作者 Guihong Zhang Jingxia Yu 《Journal of Frontier in Economic and Management Research》 2025年第1期233-248,共16页
Under the modern risk-oriented audit, a reasonable evaluation of materialmisstatement risk is crucial for certified public accountants to determine the level ofmateriality and implement further substantive procedures.... Under the modern risk-oriented audit, a reasonable evaluation of materialmisstatement risk is crucial for certified public accountants to determine the level ofmateriality and implement further substantive procedures. This paper proposes a materialmisstatement risk assessment model based on the combined use of entropy weight-TOPSISand grey relational analysis methods and evaluates the material misstatement risk in China'sMedical CRO Industry by quantitative means. Taking the medical CRO industry as anexample, this paper selects some case companies in the industry for horizontal comparison,and at the same time conducts a multi-year data comparison on the enterprise with the highestaudit risk among them. The results show that Bio-Sincerity Pharmaceutical is an enterprisewith relatively high audit risk in the Medical CRO Industry in recent years, and thecalculation results of the model are basically consistent with the actual analysis. Toeffectively prevent financial risks and audit risks, financial personnel should participate inbusiness management, analysis and budgeting, and auditors should also focus on auditsegments such as dynamic cash flow, debt structure, and business contracts and debtmanagement in combination with the characteristics of the Medical CRO Industry, so as toeffectively reduce the risk of audit misstatements. 展开更多
关键词 entropy weight-topsis Method Grey Relational Analysis Method Material Misstatement Risk Financial Risks of Company
在线阅读 下载PDF
Reconstruction of f(R) Gravity with Ordinary and Entropy-Corrected(m,n)-Type Holographic Dark Energy Model
9
作者 Prabir Rudra 《Communications in Theoretical Physics》 SCIE CAS CSCD 2016年第7期149-154,共6页
In this assignment we will present a reconstruction scheme between f(R) gravity with ordinary and entropy corrected(m, n)-type holographic dark energy. The correspondence is established and expressions for the reconst... In this assignment we will present a reconstruction scheme between f(R) gravity with ordinary and entropy corrected(m, n)-type holographic dark energy. The correspondence is established and expressions for the reconstructed f(R) models are determined. To study the evolution of the reconstructed models plots are generated. The stability of the calculated models are also investigated using the squared speed of sound in the background of the reconstructed gravities. 展开更多
关键词 dark energy dark matter modified gravity molographic entropy reconstruction
原文传递
基于OPLS-DA和熵权-Topsis法研究一氧化氮提升冷却猪肉品质 被引量:1
10
作者 叶永茂 葛庆丰 +2 位作者 吴满刚 于海 刘瑞 《食品科学》 北大核心 2025年第16期322-336,共15页
本研究应用一氧化氮(NO)短时气调处理冷却猪肉,以期改善冷却猪肉肉色、延长货架期以及提升冷却猪肉综合品质。根据气调风速、气体浓度和时间单因素试验结果,应用正交偏最小二乘判别分析、主成分分析和Pearson相关性分析,筛选冷却猪肉理... 本研究应用一氧化氮(NO)短时气调处理冷却猪肉,以期改善冷却猪肉肉色、延长货架期以及提升冷却猪肉综合品质。根据气调风速、气体浓度和时间单因素试验结果,应用正交偏最小二乘判别分析、主成分分析和Pearson相关性分析,筛选冷却猪肉理化品质综合评价指标为红度(a*值)、贮藏损失、硬度、挥发性盐基氮含量,并与感官评分构成冷却猪肉综合品质评价体系,通过熵权-Topsis法得出最终评价模型为Y=0.145×a*+0.113×贮藏损失+0.112×硬度+0.130×挥发性盐基氮含量+0.500×感官评分。响应面法确定最佳处理条件为风速1.10m/s、NO浓度117µL/L、时间41min。应用该工艺处理冷却猪肉并进行贮藏研究,结果表明该条件处理能够有效减少菌落总数、挥发性盐基氮含量以及提高亚硝基肌红蛋白含量,本研究可为提升冷却猪肉品质提供一种可行性方案,并为冷却猪肉品质提供一种综合评价模型。 展开更多
关键词 冷却猪肉 一氧化氮 气调处理 熵权-Topsis法 响应面法
在线阅读 下载PDF
二陈改良汤发酵菌种的筛选及发酵工艺的优化 被引量:1
11
作者 周妍 黄优生 +4 位作者 黄丽琼 李碧琳 董欢欢 管咏梅 朱卫丰 《食品与发酵工业》 北大核心 2025年第16期197-205,共9页
该研究以4种药食同源中药材(陈皮、橘红、茯苓、甘草)组成的二陈改良汤为原料,以乳酸菌为发酵剂,旨在开发一款新型具有乳酸菌风味的镇咳祛痰饮料。采用主成分分析法对不同乳酸菌发酵的二陈改良汤的理化指标和活性成分含量进行综合品质评... 该研究以4种药食同源中药材(陈皮、橘红、茯苓、甘草)组成的二陈改良汤为原料,以乳酸菌为发酵剂,旨在开发一款新型具有乳酸菌风味的镇咳祛痰饮料。采用主成分分析法对不同乳酸菌发酵的二陈改良汤的理化指标和活性成分含量进行综合品质评价,筛选出最适发酵菌种,基于层次分析法(analytic hierarchy process,AHP)-熵权TOPSIS法优化最佳发酵工艺参数。结果表明,副干酪乳酪杆菌HCS17-040为最适菌种。最佳工艺为料液比1∶30(g∶mL),接种量8%,发酵时间36 h,发酵温度37℃,在此优化条件下,副干酪乳杆菌HCS17-040发酵二陈改良汤中桔皮素、柚皮素、橙皮素含量与未发酵组相比分别增加了29.87%、12.77%、23.93%。研究结果表明使用乳酸菌发酵改良二陈汤可显著增加其桔皮素、柚皮素和橙皮素等活性成分的含量,可能有助于提高其镇咳祛痰的效果。 展开更多
关键词 二陈改良汤 发酵工艺 主成分分析 层次分析法 熵权TOPSIS法
在线阅读 下载PDF
融合切比雪夫距离和修正余弦相似度算法的保护二次回路测量误差识别方法
12
作者 王海明 王剑锋 +2 位作者 王仲源 姜佳利 翁汉琍 《中国电力》 北大核心 2025年第12期165-177,共13页
准确识别保护装置二次回路测量误差,对提高保护可靠性、保障电力系统稳定运行至关重要。为此,提出一种采用熵值权重法融合切比雪夫距离与修正余弦相似度算法(entropy-based weight-Chebyshev distance and modified cosine similarity,E... 准确识别保护装置二次回路测量误差,对提高保护可靠性、保障电力系统稳定运行至关重要。为此,提出一种采用熵值权重法融合切比雪夫距离与修正余弦相似度算法(entropy-based weight-Chebyshev distance and modified cosine similarity,EBW-CDMCS)的方法对保护装置二次回路测量误差进行准确识别。首先,为了确保数据分析的准确性和一致性,对测得的2组数据进行标准化预处理。通过切比雪夫距离和修正余弦相似度算法分别得到2组采样点数据之间的距离值,表征数据的离散性。然后,利用熵值权重法计算2组距离值的权重,融合得到EBW-CDMCS距离指标。最后,通过对正常工况下的二次回路测量电流数据进行分析,设定合适的阈值,将计算得到的EBM-CDMCS距离指数与阈值进行比较,识别二次回路中可能存在的测量误差。基于PSCAD搭建220kV变电站模型,仿真结果验证了所提方法的有效性和准确性。 展开更多
关键词 测量误差识别 切比雪夫距离 修正余弦相似度 熵值权重法 保护装置二次回路
在线阅读 下载PDF
基于多功能复合表面涂层的井下设备防腐蚀技术研究 被引量:1
13
作者 刘志文 李永元 +5 位作者 高健勋 张华堂 杨小全 梁戈龙 刘艳 王秋里 《安全与环境工程》 北大核心 2025年第1期179-187,200,共10页
在井下作业环境中,设备遭受的腐蚀问题极为严重,易造成设备损坏和重大安全事故。针对核桃峪井下设备的防腐蚀需求,提出了一种新颖的激光熔覆高熵合金内涂层与环氧树脂外涂层相结合的复合表面涂层防腐蚀策略。通过设置高熵合金内涂层以... 在井下作业环境中,设备遭受的腐蚀问题极为严重,易造成设备损坏和重大安全事故。针对核桃峪井下设备的防腐蚀需求,提出了一种新颖的激光熔覆高熵合金内涂层与环氧树脂外涂层相结合的复合表面涂层防腐蚀策略。通过设置高熵合金内涂层以提高涂层的整体黏附强度和耐磨性,进一步引入高致密性环氧树脂作为外涂层,并对环氧树脂进行化学改性以降低涂层的自腐蚀电流,同时,构筑高熵合金/环氧树脂Cassie界面模型,赋予涂层超疏水性。结果表明:对高熵合金进行1.0%的SiC掺杂后,涂层力学性能和抗氧化、抗化学腐蚀性能得到明显提升;引入改性环氧树脂涂层后,涂层的腐蚀电流显著降低,抗老化性能显著提高;宏观腐蚀测试结果也证明复合涂层具有优异的抗腐蚀性。该研究为复杂环境中设备的防腐蚀提供了新思路。 展开更多
关键词 防腐蚀 井下设备 激光熔覆 SiC掺杂高熵合金 改性环氧树脂 超疏水性
在线阅读 下载PDF
家庭医生团队多专业协作评价指标体系构建 被引量:2
14
作者 郑彩云 吴霜儿 +1 位作者 俞淦泉 王欣 《中国全科医学》 北大核心 2025年第28期3518-3524,共7页
背景基于家庭医生团队实施有效的多专业协作是满足居民日益复杂的健康需求、提供高质量整合型卫生服务的关键,但目前缺少针对团队多专业协作的科学可行评价工具。目的在协作四维模型(D'Amour模型)基础上建立一套家庭医生团队多专业... 背景基于家庭医生团队实施有效的多专业协作是满足居民日益复杂的健康需求、提供高质量整合型卫生服务的关键,但目前缺少针对团队多专业协作的科学可行评价工具。目的在协作四维模型(D'Amour模型)基础上建立一套家庭医生团队多专业协作评价指标体系,为家庭医生团队及其多专业协作的持续发展提供实证依据。方法通过文献分析法、政策归纳法、半结构化访谈法初步建立指标体系;于2023年4—6月,采用改良德尔菲法对24名专家进行两轮函询,根据函询结果确定评价指标体系;使用层次分析法-熵权法综合赋权法确定指标权重。结果两轮函询问卷的有效回收率均为100.0%(24/24),专家权威系数分别为0.874、0.885,肯德尔协调系数分别为0.157(χ^(2)=166.005,P<0.05)、0.146(χ^(2)=151.145,P<0.05)。最终构建了包含5个一级指标、11个二级指标、27个三级指标及其权重的家庭医生团队多专业协作评价指标体系。一级指标“共同目标与愿景”“内在化”“治理”“规范化”“激励”的权重分别为0.1267、0.1904、0.2913、0.1180、0.2754。结论构建的家庭医生团队多专业协作评价指标体系具有较强的科学性和可操作性,对提升团队多专业协作有一定的理论和实践指导意义。 展开更多
关键词 全科医学 家庭医生团队 多专业协作 改良德尔菲法 层次分析法 熵权法 综合权重法 指标体系
暂未订购
Artificial intelligence-based healthcare cybersecurity system with blockchain: modified parallel convolutional neural network for attack detection
15
作者 Swarooparani Kolsur Sridevi Hosmani 《Medicine in Novel Technology and Devices》 2025年第4期221-234,共14页
While smart wearables and remote devices have improved the speed of diagnosis and treatment,they have also created significant cybersecurity risks,especially with regard to the confidentiality and integrity of medical... While smart wearables and remote devices have improved the speed of diagnosis and treatment,they have also created significant cybersecurity risks,especially with regard to the confidentiality and integrity of medical data.Because the primary means of operation for these Internet of Things(IoT)devices is constant data transmission,they are vulnerable to cyberthreats including Distributed Denial-of-Service(DDoS)assaults and data injection.This study suggests an AI-based Healthcare Cybersecurity System(AI-HCsS)that integrates blockchain tech-nology to mitigate these vulnerabilities and provide strong,real-time patient data and healthcare system pro-tection.A new architecture is shown to identify and counteract DDoS attacks on the cloud infrastructure,and blockchain is used for safe and unchangeable data storage.The system extracts statistical,raw,and enhanced entropy-based features after performing improved min-max normalization for data pre-processing.Then,for precise DDoS attack detection,a modified Parallel Convolutional Neural Network(PCNN)is used.The model's output is interpreted using the SHapley Additive exPlanations(SHAP)approach,which identifies important characteristics that affect detection performance in order to improve transparency and aid clinical decision-making.According to experimental results,the modified PCNN outperforms traditional methods with a high detection accuracy of 91.1%.In addition to bolstering the cybersecurity of healthcare IoT ecosystems,this in-tegrated solution guarantees the real-time defense of clinical systems and patient data against changing cyberthreats. 展开更多
关键词 Healthcare Attack detection Blockchain Improved entropy modified parallel convolutional neural network
在线阅读 下载PDF
大面积质子交换膜燃料电池平行流场优化设计
16
作者 王誉霖 张晓剑 +2 位作者 管超 宋娇娇 何为 《工程热物理学报》 北大核心 2025年第3期975-981,共7页
质子交换膜燃料电池(PEMFC)生成的液态水如无法及时排出会引起“水淹”现象,进而阻碍反应气体的扩散传质,导致电池性能下降。流场结构是影响反应物和生成物输运特性的决定性因素之一。本研究通过三维两相PEMFC数值模型,对比分析了108 cm... 质子交换膜燃料电池(PEMFC)生成的液态水如无法及时排出会引起“水淹”现象,进而阻碍反应气体的扩散传质,导致电池性能下降。流场结构是影响反应物和生成物输运特性的决定性因素之一。本研究通过三维两相PEMFC数值模型,对比分析了108 cm^(2)大面积传统和阴极流道具有渐扩设计的平行流场结构的PEMFC整体性能。研究发现,改进平行流场结构增强了液态水的排出性能,并且具有更均匀的电流密度和氧气分布,因此,提升了PEMFC的整体性能。与传统平行流场相比,改进平行流场最优结构设计方案的功率密度、电流密度均匀性和温度均匀性分别提高了2.31%、15.31%和8.82%。此外,通过熵权法进行综合评价,发现最优的改进平行流场结构设计方案将PEMFC整体性能的综合评价指标从0.057提高到0.309。 展开更多
关键词 质子交换膜燃料电池 大面积改进平行流场 渐扩设计 熵权法 电池性能
原文传递
Modified multi-scale symbolic dynamic entropy and fuzzy broad learning-based fast fault diagnosis of railway point machines
17
作者 Junqi Liu Tao Wen +1 位作者 Guo Xie Yuan Cao 《Transportation Safety and Environment》 EI 2023年第4期1-7,共7页
Railway point machine(RPM)condition monitoring has attracted engineers’attention for safe train operation and accident prevention.To realize the fast and accurate fault diagnosis of RPMs,this paper proposes a method ... Railway point machine(RPM)condition monitoring has attracted engineers’attention for safe train operation and accident prevention.To realize the fast and accurate fault diagnosis of RPMs,this paper proposes a method based on entropy measurement and broad learning system(BLS).Firstly,the modified multi-scale symbolic dynamic entropy(MMSDE)module extracts dynamic characteristics from the collected acoustic signals as entropy features.Then,the fuzzy BLS takes the above entropy features as input to complete model training.Fuzzy BLS introduces the Takagi-Sug eno fuzzy system into BLS,which improves the model’s classification performance while considering computational speed.Experimental results indicate that the proposed method significantly reduces the running time while maintaining high accuracy. 展开更多
关键词 railway point machine(RPM) fault diagnosis modified multi-scale symbolic dynamic entropy(MMSDE) fuzzy board learning system(BLS)
在线阅读 下载PDF
基于改进多尺度模糊熵的滚动轴承故障诊断方法 被引量:29
18
作者 郑近德 代俊习 +2 位作者 朱小龙 潘海洋 潘紫微 《振动.测试与诊断》 EI CSCD 北大核心 2018年第5期929-934,1078,共7页
滚动轴承故障诊断的关键是敏感故障特征的提取。多尺度模糊熵(multi-scale fuzzy entropy,简称MFE)是一种衡量时间序列复杂性的有效分析方法,已经被用于滚动轴承振动信号故障特征提取。针对MFE算法中多尺度粗粒化过程存在的缺陷,笔者采... 滚动轴承故障诊断的关键是敏感故障特征的提取。多尺度模糊熵(multi-scale fuzzy entropy,简称MFE)是一种衡量时间序列复杂性的有效分析方法,已经被用于滚动轴承振动信号故障特征提取。针对MFE算法中多尺度粗粒化过程存在的缺陷,笔者采用滑动均值的方式代替粗粒化过程,提出了改进的多尺度模糊熵算法,并通过仿真信号将其与MFE进行了对比分析。在此基础上,提出了一种基于改进多尺度模糊熵与支持向量机的滚动轴承故障诊断方法。最后,将所提故障诊断方法应用于的滚动轴承实验数据分析,并与基于MFE的故障诊断方法进行了对比,结果验证了所提方法的有效性和优越性。 展开更多
关键词 多尺度模糊熵 改进多尺度模糊熵 滚动轴承 故障诊断
在线阅读 下载PDF
改进的DRASTIC地下水脆弱性评价模型及应用 被引量:14
19
作者 张珍 温忠辉 +3 位作者 鲁程鹏 束龙仓 刘波 朱伟 《水资源保护》 CAS 2014年第6期13-18,共6页
针对DRASTIC模型存在的不足,综合考虑研究区水文地质特征和人类活动的影响,提出改进的地下水脆弱性指标体系,分别采用层次分析法(AHP)、熵权法及AHP-熵权法对各指标赋权,建立改进的DRASTIC地下水模型。应用基于上述3种方法改进的模型对... 针对DRASTIC模型存在的不足,综合考虑研究区水文地质特征和人类活动的影响,提出改进的地下水脆弱性指标体系,分别采用层次分析法(AHP)、熵权法及AHP-熵权法对各指标赋权,建立改进的DRASTIC地下水模型。应用基于上述3种方法改进的模型对南京市江宁区中部地区地下水脆弱性进行评价,3种模型得到的脆弱性指数整体均呈现由中部向东北、西南方向逐渐降低的趋势,但不同模型中同一脆弱性区的面积有所差异;通过线性相关分析验证模型评价结果。结果表明,基于AHP-熵权法改进的DRASTIC模型评价结果较其他两种模型更客观真实地反映了研究区的实际情况。 展开更多
关键词 地下水 脆弱性评价 改进的DRASTIC 模型 层次分析法 熵权法 敏感性分析
在线阅读 下载PDF
基于灰关联熵分析法的高粘改性沥青关键指标 被引量:44
20
作者 祝斯月 陈拴发 +1 位作者 秦先涛 李祖仲 《材料科学与工程学报》 CAS CSCD 北大核心 2014年第6期863-867,共5页
为了研究高粘改性沥青关键指标对排水沥青混合料性能的影响,选取SBS改性沥青、TPS高粘改性沥青和自主研制高粘改性沥青,采用灰关联熵分析法,分析了高粘改性沥青多种指标对排水沥青混合料高温抗车辙能力和抗水损害能力的影响。结果表明:... 为了研究高粘改性沥青关键指标对排水沥青混合料性能的影响,选取SBS改性沥青、TPS高粘改性沥青和自主研制高粘改性沥青,采用灰关联熵分析法,分析了高粘改性沥青多种指标对排水沥青混合料高温抗车辙能力和抗水损害能力的影响。结果表明:高粘改性沥青混合料的动稳定度和劈裂强度比分别为SBS改性沥青混合料的2倍和1.2倍,因此能显著增强排水沥青混合料的高温以及水稳性能。沥青的零剪切粘度与混合料动稳定度的灰熵关联度为0.983,对排水沥青混合料的高温性能影响最大;沥青的粘韧性、韧性与混合料劈裂强度比的灰熵关联度分别0.991和0.989,对排水沥青混合料的水稳性能影响显著。建议采用沥青的60℃零剪切粘度、粘韧性和韧性作为评价高粘改性沥青的关键性指标。 展开更多
关键词 道路工程 排水沥青混合料 高粘改性沥青 关键指标 灰关联熵
在线阅读 下载PDF
上一页 1 2 7 下一页 到第
使用帮助 返回顶部