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61.
遗传算法在反演概率积分法预计参数时从参数取值范围内的串集开始搜索,并使用弹性策略来维持群体的多样性,使得算法可以跨过局部收敛的障碍,向全局最优解方向进化;但这种概率化的寻优算法存在局部探索能力差、结果不稳定的缺陷,只能获得问题的近似最优解。模矢法是一种降梯度算法,算法局部探索能力强、收敛快;但这种算法对初值选取敏感,初值选择不当易陷入局部极值。本文提出并实现了一种模矢法与遗传算法结合的组合算法:先使用遗传算法求得参数的全局近似最优解,然后将近似最优解作为探索初值,使用模矢法获得参数的稳定、精确最优解。研究结果表明:组合算法反演概率积分法预计参数的精确度高、收敛快、稳定性好,综合性能较遗传算法和模矢法有明显优势。  相似文献   
62.
This paper focuses on consensus quantized control design problem for uncertain nonlinear multiagent systems with unmeasured states. Every follower can be denoted through a system with unmeasurable states, hysteretic quantized input, and unknown nonlinearities. Fuzzy state observer and Fuzzy logic systems are employed to estimate unmeasured states and approximate unknown nonlinear functions, respectively. The hysteretic quantized input can be split into two bounded nonlinear functions to avoid chattering problem. By combining adaptive backstepping and first‐order filter signals, an observer‐based fuzzy adaptive quantized control scheme is designed for each follower. All signals exist in closed‐loop systems are semiglobally uniformly ultimately bounded, and all followers can accomplish a desired consensus results. Finally, a numerical example is employed to elaborate the effectiveness of proposed control strategy.  相似文献   
63.
q-Rung orthopair fuzzy sets (q-ROFSs), originally presented by Yager, are a powerful fuzzy information representation model, which generalize the classical intuitionistic fuzzy sets and Pythagorean fuzzy sets and provide more freedom and choice for decision makers (DMs) by allowing the sum of the q t h power of the membership and the q t h power of the nonmembership to be less than or equal to 1. In this paper, a new class of fuzzy sets called q-rung orthopair uncertain linguistic sets (q-ROULSs) based on the q-ROFSs and uncertain linguistic variables (ULVs) is proposed, and this can describe the qualitative assessment of DMs and provide them more freedom in reflecting their belief about allowable membership grades. On the basis of the proposed operational rules and comparison method of q-ROULSs, several q-rung orthopair uncertain linguistic aggregation operators are developed, including the q-rung orthopair uncertain linguistic weighted arithmetic average operator, the q-rung orthopair uncertain linguistic ordered weighted average operator, the q-rung orthopair uncertain linguistic hybrid weighted average operator, the q-rung orthopair uncertain linguistic weighted geometric average operator, the q-rung orthopair uncertain linguistic ordered weighted geometric operator, and the q-rung orthopair uncertain linguistic hybrid weighted geometric operator. Then, some desirable properties and special cases of these new operators are also investigated and studied, in particular, some existing intuitionistic fuzzy aggregation operators and Pythagorean fuzzy aggregation operators are proved to be special cases of these new operators. Furthermore, based on these proposed operators, we develop an approach to solve the multiple attribute group decision making problems, in which the evaluation information is expressed as q-rung orthopair ULVs. Finally, we provide several examples to illustrate the specific decision-making steps and explain the validity and feasibility of two methods by comparing with other methods.  相似文献   
64.
Weighted power means with weights and exponents serving as their parameters are generalizations of arithmetic means. Taking into account decision makers' flexibility in decision making, each attribute value is usually expressed by a q-rung orthopair fuzzy value (q-ROFV, q1), where the former indicates the support for membership, the latter support against membership, and the sum of their qth powers is bounded by one. In this paper, we propose the weighted power means of q-rung orthopair fuzzy values to enrich and flourish aggregations on q-ROFVs. First, the q-rung orthopair fuzzy weighted power mean operator is presented, and its boundedness is precisely characterized in terms of the power exponent. Then, the q-rung orthopair fuzzy ordered weighted power mean operator is introduced, and some of its fundamental properties are investigated in detail. Finally, a novel multiattribute decision making method is explored based on developed operators under the q-rung orthopair fuzzy environment. A numerical example is given to illustrate the feasibility and validity of the proposed approach, and it is shown that the power exponent is an index suggesting the degree of the optimism of decision makers.  相似文献   
65.
水文水资源学家陈守煜先生学术研究的知识图谱分析   总被引:3,自引:0,他引:3  
为探索水文水资源学家陈守煜先生学术研究历程及其演变规律,以其335篇文献作为数据基础,采用共现分析等文献计量可视化分析方法,通过文献发表的时间分布、学科和期刊分布、高被引文献分布和研究主题等方面的知识图谱分析,系统分析了陈先生的学术研究历程。结果显示:陈守煜先生学术研究生命周期历时达62年,在其60岁后出现了2个学术创新高峰期;其学术研究特色荟萃于其河渠非恒定流计算、模糊集理论的水文水资源应用、模糊水文水资源学基本理论、模糊聚类-识别-优选统一理论、可变模糊集理论和可变模糊集理论的水文水资源应用6个研究主题,其中主题1为后续的5个模糊水文水资源学创新主题奠定了数值计算的研究方法论,主题2为模糊集现有理论的应用探索,主题3至主题5为面向工程应用的模糊集理论不断深入创新,主题6为可变模糊集理论的应用探索,形成了"紧密结合应用-持续理论创新-创新理论再应用"这种理论与实践互馈的研究特色。他每一阶段的研究目标比较集中、明确,与其研究主题密切对应,显著提高了研究效率;他的学术研究影响广泛,合计被引8554次,缘于他的源头理论创新。陈先生的研究,理论与应用不断互馈,贵在厚积薄发、深入钻研、持续创新,其研究理念和方法论,对水利科学的学术创新研究具有重要的启示作用和深远影响。  相似文献   
66.
为准确评价尾矿库的安全等级,以黄金洞尾矿库为例,分析影响尾矿库安全的各因素之间的关系,综合运用模糊多元联系度理论与层次分析法(AHP),建立了包含5个影响因素和26个影响因子的尾矿库综合安全评价模型。由AHP得出各项主、客观指标的权重系数,引入模糊多元联系度理论,综合考虑确定性与不确定性因素,处理综合集成问题,构造隶属函数量化指标的实测值。结果表明:黄金洞尾矿库安全等级为Ⅱ级,尾矿库处于较稳定状态。经比较不确定性因素大小,得出尾矿排放(B3)>尾矿坝(B2)>安全管理(B1)>尾矿输送与回水(B5)>排洪系统(B4),说明尾矿排放指标的不确定性因素最大,需对尾矿排放加强管理。该模型得到的评价结果与实际结果相吻合,为尾矿库安全性评价提供了一种可行的方法。  相似文献   
67.
The present work is aimed at performing a qualitative analysis of the effect of maintenance intensity on energy consumption, energy costs and emissions in healthcare centres. Most relevant variables involved in the maximization of the building efficiency were determined by means of fuzzy cognitive maps. Twelve variables were observed to show a direct connection to the energy and environmental efficiency as well as to its maintenance condition. The joint effect of these factors was seen to improve the overall performance of the building in terms of efficiency. However, even though maintenance appeared as one of the most highly-rated variables, it did not seem to affect the overall performance by itself, but it was rather due to the synergistic action of the remaining variables. The behaviour of those variables was evidenced to show a significant change for buildings below 1250?m2 floor area as compared to those exceeding such threshold value.  相似文献   
68.
In this paper, the development of the models for the prediction of rock mass P wave velocity is presented. For model development, the database of 53 cases including widely used and recorded drilling parameters and P wave velocity was constructed from the field studies conducted in 13 open pit lignite mines. Both conventional linear, non-linear multiple regression and Adaptive Neuro Fuzzy Inference System (ANFIS) were used for model development. Prediction performance indicators showed that ANFIS model presented the best performance and it can successfully be used for the preliminary prediction of P wave velocities of rock masses.  相似文献   
69.
针对传统协同过滤(CF)推荐算法存在评分矩阵稀疏、扩展性弱和推荐准确率低的缺陷,提出一种改进模糊划分聚类的协同过滤推荐算法(GIFP-CCF+)。在传统基于修正余弦相似度计算方法上,引入时间差因子、热门物品权重因子以及冷门物品权重因子以改善相似度计算结果;同时引入改进模糊划分的GIFP-FCM算法,将属性特征相似的项目聚成一类,构造索引矩阵,同索引间根据项目间的相似度寻找项目最近邻居构成推荐,从而提高协同过滤算法(CF)的精度。通过与Kmeans-CF、FCM-CF和GIFP-CCF算法进行仿真对比实验,证明了GIFP-CCF+算法在推荐结果和推荐精度上具有一定的优越性。  相似文献   
70.
为维持铝电解生产的持续性,保证电解槽的物耗稳定和能耗稳定,通过对铝厂数据的挖掘与建模,提出一整套维持电解槽稳定的策略方法,并用于指导实际生产。首先为数据去噪,针对铝厂数据分布特征未知的特点,提出一种无参自适应的模糊聚类方法,通过迭代自适应得到类簇个数和簇中心;根据聚类结果,将铝厂数据按实际意义标签化,提出一种基于距离的连续属性朴素贝叶斯算法,对分类器使用增量思想,使算法动态分类准确率得到提高;应用单槽测试集数据,通过累积法完成当天各指标等级趋势的预测,确定各指标下变量相对于前一天的变化量,完成预测。实验发现,预测模型可完成铝电解关键指标的预测;提出的聚类、分类算法在UCI数据及铝厂数据上表现良好。  相似文献   
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