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Ellipsoidal bounding set-membership identification approach for robust fault diagnosis with application to mobile robots 被引量:7
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作者 Bo Zhou Kun Qian +1 位作者 Xudong Ma Xianzhong Dai 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2017年第5期986-995,共10页
A robust fault diagnosis approach is developed by incorporating a set-membership identification (SMI) method. A class of systems with linear models in the form of fault related parameters is investigated, with model u... A robust fault diagnosis approach is developed by incorporating a set-membership identification (SMI) method. A class of systems with linear models in the form of fault related parameters is investigated, with model uncertainties and parameter variations taken into account explicitly and treated as bounded errors. An ellipsoid bounding set-membership identification algorithm is proposed to propagate bounded uncertainties rigorously and the guaranteed feasible set of faults parameters enveloping true parameter values is given. Faults arised from abrupt parameter variations can be detected and isolated on-line by consistency check between predicted and observed parameter sets obtained in the identification procedure. The proposed approach provides the improved robustness with its ability to distinguish real faults from model uncertainties, which comes with the inherent guaranteed robustness of the set-membership framework. Efforts are also made in this work to balance between conservativeness and computation complexity of the overall algorithm. Simulation results for the mobile robot with several slipping faults scenarios demonstrate the correctness of the proposed approach for faults detection and isolation (FDI). 展开更多
关键词 set-membership identification fault diagnosis fault detection and isolation (FDI) bounded error mobile robot
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INVESTIGATION ON MAKING MEMBERSHIP FUNCTION OF WATER MASS FROM MIXING MODIFIED PROCESS
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作者 李凤岐 苏育嵩 +1 位作者 喻祖祥 王凤钦 《中国海洋大学学报(自然科学版)》 CAS CSCD 1989年第S1期445-461,共17页
A water mass in the sea area under investigation is defined as a fuzzy subset in the discourse universe. Possible forms of membership function of water masses in the mixing modified process are discussed with the mixi... A water mass in the sea area under investigation is defined as a fuzzy subset in the discourse universe. Possible forms of membership function of water masses in the mixing modified process are discussed with the mixing theory for conservative concentration of sea water. It may provide bases for making membership functions. Results in this paper may be extended and applied to shallow water. Examples and discussion are given in this paper. 展开更多
关键词 water mass fuzzy setS membership function the measure-value space
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Research on Method R_w for Discrete Membership Functions
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作者 崔宝灵 黄梯云 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 1998年第2期10-12,共3页
In this paper, a number of concepts related to continuous membership function (CMFs) advanced in [2] are extended to discrete membership functions (DMFs) in the light of the characteristics of DMFs so that fuzzy reaso... In this paper, a number of concepts related to continuous membership function (CMFs) advanced in [2] are extended to discrete membership functions (DMFs) in the light of the characteristics of DMFs so that fuzzy reasoning method R. based upon CMFs suits the case of DMFs. 展开更多
关键词 FUZZY setS membership FUNCTION FUZZY REASONING
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Describing Fuzzy Membership Function and Detecting the Outlier by Using Five Number Summary of Data
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作者 Md. Farooq Hasan Md. Abdus Sobhan 《American Journal of Computational Mathematics》 2020年第3期410-424,共15页
One of the most important activities in data science is defining a membership function in fuzzy system. Although there are few ways to describe membership function like artificial neural networks, genetic algorithms e... One of the most important activities in data science is defining a membership function in fuzzy system. Although there are few ways to describe membership function like artificial neural networks, genetic algorithms etc.;they are very complex and time consuming. On the other hand, the presence of outlier in a data set produces deceptive results in the modeling. So it is important to detect and eliminate them to prevent their negative effect on the modeling. This paper describes a new and simple way of constructing fuzzy membership function by using five-number summary of a data set. Five states membership function can be created in this new method. At the same time, if there is any outlier in the data set, it can be detected with the help of this method. Usually box plot is used to identify the outliers of a data set. So along with the new approach, the box plot has also been drawn so that it is understood that the results obtained in the new method are accurate. Several real life examples and their analysis have been discussed with graph to demonstrate the potential of the proposed method. The results obtained show that the proposed method has given good results. In the case of outlier, the proposed method and the box plot method have shown similar results. Primary advantage of this new procedure is that it is not as expensive as neural networks, and genetic algorithms. 展开更多
关键词 Fuzzy set membership Function Five Number Summary OUTLIERS
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A novel vague set approach for selective contrast enhancement of mammograms using multiresolution
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作者 Arpita Das Mahua Bhattacharya 《Journal of Biomedical Science and Engineering》 2009年第8期575-581,共7页
The proposed algorithm introduces a novel vague set approach to develop a selective but robust, flexible and intelligent contrast enhancement technique for mammograms. Wavelet based filtering analysis can produce Low ... The proposed algorithm introduces a novel vague set approach to develop a selective but robust, flexible and intelligent contrast enhancement technique for mammograms. Wavelet based filtering analysis can produce Low Frequency (LF) and High Frequency (HF) subbands of the original input images. The extremely small size microcalcifications become visible under multiresolution techniques. LF subband is then fuzzified by conventional fuzzy c-means clustering (FCM) algorithm with justified number of clusters. HF components, representing the narrow protrusions and other fine details are also fuzzified by FCM with justified number of clusters. Vague set approach captures the hesitancies and uncertainties of truly affected masses/other breast abnormalities with normal glandular tissues. After highlighting the masses/microcalcifications accurately, both LF and HF subbands are transformed back to the original resolution by inverse wavelet transform. The results show that the proposed method can successfully enhance the selected regions of mammograms and provide better contrast images for visual interpretation. 展开更多
关键词 MULTIRESOLUTION VAGUE set APPROACH True- membership FUNCTIONS False-membership FUNCTIONS
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Rough Set Processing Model for Fuzzy Decision Tables with Weights
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作者 Hao-Dong Zhu Hong-Chan Li 《Journal of Electronic Science and Technology》 CAS 2011年第2期133-135,共3页
The classical rough set can not show the fuzziness and the importance of objects in decision procedure because it uses definite form to express each object. In order to solve this problem,this paper firstly introduces... The classical rough set can not show the fuzziness and the importance of objects in decision procedure because it uses definite form to express each object. In order to solve this problem,this paper firstly introduces a special decision table in which each object has a membership degree to show its fuzziness and has been assigned a weight to show its importance in decision procedure. Then,the special decision table is studied and the relevant rough set model is provided. In the meantime,relevant definitions and theorems are proposed. On the above basis,an attribute reduction algorithm is presented. Finally,feasibility of the relevant rough set model and the presented attribute reduction algorithm are verified by an example. 展开更多
关键词 Attribute reduction decision table membership degree rough set
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A new approach of fuzzy comprehensive evaluation on rough set
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作者 ZENG Huang-lin CHEN Shun-ling 《通讯和计算机(中英文版)》 2008年第10期33-36,共4页
关键词 模糊综合评价 粗糙集 计算方法 逻辑关系
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Rough function model and rough membership function 被引量:1
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作者 Wang Yun Guan Yanyong Huang Zhiqin 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2008年第3期522-528,共7页
Two pairs of approximation operators, which are the scale lower and upper approximations as well as the real line lower and upper approximations, are defined. Their properties and antithesis characteristics are analyz... Two pairs of approximation operators, which are the scale lower and upper approximations as well as the real line lower and upper approximations, are defined. Their properties and antithesis characteristics are analyzed. The rough function model is generalized based on rough set theory, and the scheme of rough function theory is made more distinct and complete. Therefore, the transformation of the real function analysis from real line to scale is achieved. A series of basic concepts in rough function model including rough numbers, rough intervals, and rough membership functions are defined in the new scheme of the rough function model. Operating properties of rough intervals similar to rough sets are obtained. The relationship of rough inclusion and rough equality of rough intervals is defined by two kinds of tools, known as the lower (upper) approximation operator in real numbers domain and rough membership functions. Their relative properties are analyzed and proved strictly, which provides necessary theoretical foundation and technical support for the further discussion of properties and practical application of the rough function model. 展开更多
关键词 rough set theory rough function model indiscernibility relation rough membership function roughnumber rough interval.
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DISCUSSION OF SOME CONCEPTIONS OF A WATER MASS BASED ON THE THEORY OF FUZZY SETS
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作者 李凤岐 苏育嵩 +1 位作者 王凤钦 喻祖祥 《中国海洋大学学报(自然科学版)》 CAS CSCD 1989年第S1期430-444,共15页
The fundamental principle for differentiating water masses is a strict consideration of their relative "interior homogeneity" and obvious "exterior differences" with others in characteristics. The ... The fundamental principle for differentiating water masses is a strict consideration of their relative "interior homogeneity" and obvious "exterior differences" with others in characteristics. The conceptions of water type, water mass and water system are dealt with on the basis of the theory of fuzzy sets. A proposal to apply the theory of fuzzy sets to define the water mass and its core, independent area, boundary and mixing area is put forward.As an example, the membership function of the surface water masses in the Yellow Sea and East China Sea in August, 1979, are considered. Their cores, independent areas, boundaries, mixing areas and the approximation degrees between different water masses are calculated respectively. The water masses are ranged according to their fuzzy degrees. 展开更多
关键词 WATER mass fuzzy setS WATER type WATER system membership function the YELLOW SEA the East China SEA
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Commonsense Reasoning and Nonmonotonic Aggregation Connectives on Fuzzy Sets
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作者 刘东波 《High Technology Letters》 EI CAS 1995年第2期43-47,共5页
Commonsense representation and manipulation based on fuzzy logic is a new research field which handles the incompleteness, error-tolerability (allow exceptions) and uncertainty associated with commonsense knowledge. I... Commonsense representation and manipulation based on fuzzy logic is a new research field which handles the incompleteness, error-tolerability (allow exceptions) and uncertainty associated with commonsense knowledge. In this paper, we introduce a pair of nonmonotonic aggregation connectives on fuzzy sets-soft intersection and soft union, in the light of Zadeh’s fuzzy set theory. Some important features of the nonmonotonic connectives are also discussed. 展开更多
关键词 cussed. Commonsense knowledge Nonmonotonic REASONING Fuzzy sets SOFT INTERSECTION SOFT UNION
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快速收敛的低复杂度稀疏水声信道估计方法
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作者 李宪鹏 王海斌 +3 位作者 汪俊 台玉朋 甘维明 张永霖 《应用声学》 CSCD 北大核心 2024年第4期709-718,共10页
针对水声信道的稀疏特性,该文基于集员L1范数约束比例调节仿射投影算法,在不增加稳态误差的前提下,首先采用一种鲁棒集员滤波思想,通过设定动态误差门限加速算法收敛速度;另外针对其矩阵计算复杂度高问题,利用历史的比例调节矩阵优化信... 针对水声信道的稀疏特性,该文基于集员L1范数约束比例调节仿射投影算法,在不增加稳态误差的前提下,首先采用一种鲁棒集员滤波思想,通过设定动态误差门限加速算法收敛速度;另外针对其矩阵计算复杂度高问题,利用历史的比例调节矩阵优化信道更新方程,使得某些过程矩阵可通过递归方法更新,从矩阵运算角度降低了计算复杂度。湖试和海试数据处理结果表明,面对弱时变和强时变信道时,此方法相对已有稀疏水声信道估计方法略微降低稳态误差的同时具有更快的收敛速度,并从矩阵运算和迭代次数两个方面降低了计算复杂度。 展开更多
关键词 仿射投影算法 收敛速度 集员滤波 低复杂度实现
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可变TOPSIS水安全韧性三支决策方法及应用
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作者 杨亚锋 王红瑞 +2 位作者 曹永强 刘琳 曹文梅 《水科学进展》 EI CAS CSCD 北大核心 2024年第4期595-605,共11页
为克服当前水安全评价中常用的TOPSIS方法适用于排序但决策指导意义相对较弱的不足,借助可变模糊集中的相对隶属度方法改进其数据标准化过程,进而计算贴近度用于估计三支决策中的条件概率,基于综合阈值生成三支决策规则;设置不同的风险... 为克服当前水安全评价中常用的TOPSIS方法适用于排序但决策指导意义相对较弱的不足,借助可变模糊集中的相对隶属度方法改进其数据标准化过程,进而计算贴近度用于估计三支决策中的条件概率,基于综合阈值生成三支决策规则;设置不同的风险规避系数(σ),动态细化三支决策粒度,实现等级评判和调控决策。基于韧性理念,从抵抗性、恢复性和适应性3个方面构建水安全评价指标体系,并以京津冀地区为例开展实证研究。结果表明:2006—2020年,京津冀三地的水安全水平稳中有升,空间分异特征显著;北京和天津年际变化较小,河北2015年以来则有显著提升;当前北京和天津水安全的主要韧性调控方向为抵抗性,而河北则需要进一步加强适应性。 展开更多
关键词 水安全 韧性 可变模糊集 相对隶属度 TOPSIS 三支决策 京津冀地区
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基于布隆过滤器的零知识集成员证明效率提升
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作者 杨书鑫 李鹏 《软件工程》 2024年第7期47-51,60,共6页
针对区块链中数据的安全验证问题(数据的动态增加导致零知识集成员证明参数更新频繁、参数生成和验证时间变长),进行了创新性的完善。提出了一种新型的数据存储模型,结合优化的跳表索引,提高了数据验证的安全性和效率。实验结果表明,基... 针对区块链中数据的安全验证问题(数据的动态增加导致零知识集成员证明参数更新频繁、参数生成和验证时间变长),进行了创新性的完善。提出了一种新型的数据存储模型,结合优化的跳表索引,提高了数据验证的安全性和效率。实验结果表明,基于布隆过滤器的新型数据存储模型和外部索引,虽然增加了空间复杂度,但是借助预校验机制,提高了约45%的安全校验速度。此外,优化后的时间跳表总体上提高了约50%的区块检索速度,并且索引更新更加便捷。 展开更多
关键词 区块链 零知识集成员证明 数据存储模型 布隆过滤器 跳表
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适应电压支撑下的光伏发电机组最大功率点控制技术 被引量:1
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作者 金世和 谢晨 +1 位作者 曲浩 范金鹏 《微电机》 2024年第1期48-52,共5页
常规的光伏发电机组最大功率点控制技术,在机械功率的调整上,缺少对适应电压支撑的考虑,导致最大功率点控制效果不好。基于此,提出适应电压支撑下的光伏发电机组最大功率点控制技术。使用功率信号反馈法,检测光伏发电机组的功率,将光伏... 常规的光伏发电机组最大功率点控制技术,在机械功率的调整上,缺少对适应电压支撑的考虑,导致最大功率点控制效果不好。基于此,提出适应电压支撑下的光伏发电机组最大功率点控制技术。使用功率信号反馈法,检测光伏发电机组的功率,将光伏发电机组的固有功率,作为主要参数。根据发电机组运行状态点的变化,对光伏发电机组功率进行跟踪,以光伏发电机组功率跟踪结果为基础,在适应电压支撑下,通过双输入单输出的结构,调节机械功率,导入调节后的机械功率,将其作为最大功率点控制的基础数据。按照隶属函数,对控制器参数进行实时调整,从而完成对光伏发电机组最大功率点控制。结果表明,在使用本文设计的方法进行控制后,光伏发电机组的最大功率振幅有效降低,控制效果较好,具有较好应用价值。 展开更多
关键词 适应电压支撑 光伏发电机组 最大功率点控制 隶属函数 功率振幅
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一种改进的Vague集相似度量公式及其在生态调度评价中应用
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作者 胡汭 《淮北师范大学学报(自然科学版)》 CAS 2024年第3期18-22,共5页
长江防汛期间洪水影响其下游鱼类产卵、生存等鱼类生态平衡,需要合理科学制定长江电站临时日流量生态调度方案以满足特殊时期长江下游鱼类生态需求。采用模糊集相似度作为权衡电站调制效益的准则,以长江下游水电站—向家坝水电站为例,... 长江防汛期间洪水影响其下游鱼类产卵、生存等鱼类生态平衡,需要合理科学制定长江电站临时日流量生态调度方案以满足特殊时期长江下游鱼类生态需求。采用模糊集相似度作为权衡电站调制效益的准则,以长江下游水电站—向家坝水电站为例,剖析其2013—2023年4-9月份的每日水流量数据,再根据线性插值方法构建流量阈值的Vague集隶属度函数,并创建一种相似度度量公式来评价各月份水文数据。应用所建相似度对4种水文数据方案进行评估,结果得到与每个月份相似度最高的方案。探究结果可以为电站临时生态调度方案的选择和评价提供参考。 展开更多
关键词 VAGUE集 相似度量 隶属度 生态调度
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集对模糊联系数构建与因素影响重要性分析
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作者 李莎莎 崔铁军 《安全与环境学报》 CAS CSCD 北大核心 2024年第4期1284-1292,共9页
为研究系统及其在因素影响下的安全性特征,必须考虑各方面的数据模糊性和不确定性。因此需要一种能同时表示系统及数据模糊性和不确定性的方法,为此提出了一种结合模糊数学隶属函数和集对分析联系数的方法。首先,论述了两者的等效关系;... 为研究系统及其在因素影响下的安全性特征,必须考虑各方面的数据模糊性和不确定性。因此需要一种能同时表示系统及数据模糊性和不确定性的方法,为此提出了一种结合模糊数学隶属函数和集对分析联系数的方法。首先,论述了两者的等效关系;然后,通过将各模糊语义分级中隶属函数的积分与总积分的比值作为该语义对应集对联系数的系数,建立单因素集对模糊联系数;使用同、异、反三状态逻辑真值表将单因素集对模糊联系数耦合形成多因素集对模糊联系数;最后,提出使用单因素集对模糊联系数的系统安全因素影响分析方法。通过两因素五级语义划分以系统安全为目标构建了集对模糊类联系数,并分析了两因素对系统安全影响的程度和排序。研究表明,将模糊数学隶属函数与集对分析联系数关联起来能同时描述数据的模糊性和不确定性,具有较好的研究性质和前景。 展开更多
关键词 安全科学技术基础学科 模糊隶属函数 集对联系数 不确定性 多因素
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New Approaches to the Prognosis and Diagnosis of Breast Cancer Using Fuzzy Expert Systems
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作者 Elias Ayinbila Apasiya Abdul-Mumin Salifu Peter Awon-Natemi Agbedemnab 《Journal of Computer and Communications》 2024年第5期151-169,共19页
Breast cancer remains a significant global health challenge, necessitating effective early detection and prognosis to enhance patient outcomes. Current diagnostic methods, including mammography and MRI, suffer from li... Breast cancer remains a significant global health challenge, necessitating effective early detection and prognosis to enhance patient outcomes. Current diagnostic methods, including mammography and MRI, suffer from limitations such as uncertainty and imprecise data, leading to late-stage diagnoses. To address this, various expert systems have been developed, but many rely on type-1 fuzzy logic and lack mobile-based applications for data collection and feedback to healthcare practitioners. This research investigates the development of an Enhanced Mobile-based Fuzzy Expert system (EMFES) for breast cancer pre-growth prognosis. The study explores the use of type-2 fuzzy logic to enhance accuracy and model uncertainty effectively. Additionally, it evaluates the advantages of employing the python programming language over java for implementation and considers specific risk factors for data collection. The research aims to dynamically generate fuzzy rules, adapting to evolving breast cancer research and patient data. Key research questions focus on the comparative effectiveness of type-2 fuzzy logic, the handling of uncertainty and imprecise data, the integration of mobile-based features, the choice of programming language, and the creation of dynamic fuzzy rules. Furthermore, the study examines the differences between the Mamdani Inference System and the Sugeno Fuzzy Inference method and explores challenges and opportunities in deploying the EMFES on mobile devices. The research identifies a critical gap in existing breast cancer diagnostic systems, emphasizing the need for a comprehensive, mobile-enabled, and adaptable solution by developing an EMFES that leverages Type-2 fuzzy logic, the Sugeno Inference Algorithm, Python Programming, and dynamic fuzzy rule generation. This study seeks to enhance early breast cancer detection and ultimately reduce breast cancer-related mortality. 展开更多
关键词 EMFES Breast Cancer Type-2 Fl Soft Computing membership Functions Fuzzy set Fuzzy Rules Risk Factors.
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基于事故树与直觉模糊集的10 kV配电网互联安全状态模糊综合评价模型
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作者 徐颖 《微型电脑应用》 2024年第11期226-229,233,共5页
由于自然故障或网络攻击导致的信息失效事件频发,10 kV配电网互联安全状态存在评价结果偏差较大的问题,对此,研究基于事故树与直觉模糊集的10 kV配电网互联安全状态模糊综合评价模型。通过直觉模糊集,处理10 kV配电网基础数据,建立事件... 由于自然故障或网络攻击导致的信息失效事件频发,10 kV配电网互联安全状态存在评价结果偏差较大的问题,对此,研究基于事故树与直觉模糊集的10 kV配电网互联安全状态模糊综合评价模型。通过直觉模糊集,处理10 kV配电网基础数据,建立事件上下位关系类型,定义配电网中不确定性的运行状态。分析配电网运行流程,结合供电能力和运行水平,选择综合性评价指标,设置安全评价规则,构建模糊评价指标体系。基于事故树计算评价指标重要度,按照基本事件的安全影响程度,构建配电网互联安全状态评价模型。实验结果表明,在不同类型供电分区10 kV配电网可靠性评估中,当应用所提模型后,能够真实反映O、P、Q 3个分区的可靠性隶属度,与配电网的真实运行情况相符合,能够真实地反映配电网运行情况,当发生问题时能够及时跟踪,缓解信息失效问题。 展开更多
关键词 事故树 直觉模糊集 10 kV配电网 安全状态 可靠性隶属度
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多级模糊评判法在公路网规划方案评价中的应用 被引量:26
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作者 过秀成 肖慎 +1 位作者 张立早 宋辉 《公路交通科技》 CAS CSCD 北大核心 2003年第1期45-48,共4页
通过对公路网规划方案评价指标体系总体分析 ,运用层次分析法 (AHP)实现对评价指标的选取 ,运用模糊统计方法确定非定量指标的隶属度 ,而对于定量评价指标隶属度值 ,则按效益型指标和成本型指标分别加以确定 ,运用频数统计法确定评价指... 通过对公路网规划方案评价指标体系总体分析 ,运用层次分析法 (AHP)实现对评价指标的选取 ,运用模糊统计方法确定非定量指标的隶属度 ,而对于定量评价指标隶属度值 ,则按效益型指标和成本型指标分别加以确定 ,运用频数统计法确定评价指标的权重 。 展开更多
关键词 多级模糊评判法 公路网 规划方案 评价指标 隶属度 权重 选取
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覆盖变精度粗糙区间直觉模糊集模型探究
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作者 吴武顺 郑艺峰 《莆田学院学报》 2024年第2期62-68,共7页
概述区间直觉模糊集的基本理论,利用所定义的平均隶属度、平均非隶属度,建立基于覆盖的变精度粗糙区间直觉模糊集的4种模型,并讨论这4种模型的一些相关性质、与现有模型的关系以及4种模型之间的关系;最后,对4种模型进行实例分析。
关键词 覆盖 变精度 平均隶属度 平均非隶属度 区间直觉模糊集
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