scispace - formally typeset
Search or ask a question
Topic

Fuzzy number

About: Fuzzy number is a research topic. Over the lifetime, 35606 publications have been published within this topic receiving 972544 citations.


Papers
More filters
Journal ArticleDOI
TL;DR: A new Lyapunov–Krasovskii functional is designed to investigate the stability and stabilization of continuous-time T–S fuzzy systems with time delay, and the information of the time derivative of membership functions can also be used to reduce the conservativeness of finding the maximum delay bounds.
Abstract: Till now, there are lots of stability and stabilization results about Takagi–Sugeno (T–S) fuzzy systems with time delay, but most of them are independent of the analysis of membership functions. Since the membership functions are an essential component to make a fuzzy system different from others, the conditions without its information are conservative. In this brief paper, a new Lyapunov–Krasovskii functional is designed to investigate the stability and stabilization of continuous-time T–S fuzzy systems with time delay. Different from the existing results in the literature, the integrand of the Lyapunov–Krasovskii functional in this paper depends not only on the integral variable, but also on the membership functions, and thus, the information of the time derivative of membership functions can also be used to reduce the conservativeness of finding the maximum delay bounds. Utilizing the information of the time derivative of membership, a number of controllers are designed according to their sign, and then, a switching idea is applied to stabilize the fuzzy system. In the end, two examples are given to illustrate the feasibility and validity of the design and analysis.

165 citations

Journal ArticleDOI
TL;DR: The concept of intuitionistic fuzzy set theory is applied to generalize results concerning hypergraphs to determine what properties of the sequence of crisp structures characterize a given property of the intuitionists' fuzzy structure.

165 citations

Journal ArticleDOI
TL;DR: A generalized Hyers-Ulam-Rassias stability theorem in the fuzzy sense is established and it is proved that if a fuzzy approximate Jensen mapping is continuous at a point, then it can approximate it by an everywhere continuous Jensen mapping.

165 citations

Journal ArticleDOI
TL;DR: Three data-driven water level forecasting models are presented and discussed and it is shown that the two models based on the fuzzy logic approaches perform better when the physical phenomena considered are synthesised by both a limited number of variables and IF-THEN logic statements, while the ANN approach increases its performance when more detailed information is used.
Abstract: . In this study three data-driven water level forecasting models are presented and discussed. One is based on the artificial neural networks approach, while the other two are based on the Mamdani and the Takagi-Sugeno fuzzy logic approaches, respectively. All of them are parameterised with reference to flood events alone, where water levels are higher than a selected threshold. The analysis of the three models is performed by using the same input and output variables. However, in order to evaluate their capability to deal with different levels of information, two different input sets are considered. The former is characterized by significant spatial and time aggregated rainfall information, while the latter considers rainfall information more distributed in space and time. The analysis is made with great attention to the reliability and accuracy of each model, with reference to the Reno river at Casalecchio di Reno (Bologna, Italy). It is shown that the two models based on the fuzzy logic approaches perform better when the physical phenomena considered are synthesised by both a limited number of variables and IF-THEN logic statements, while the ANN approach increases its performance when more detailed information is used. As regards the reliability aspect, it is shown that the models based on the fuzzy logic approaches may fail unexpectedly to forecast the water levels, in the sense that in the testing phase, some input combinations are not recognised by the rule system and thus no forecasting is performed. This problem does not occur in the ANN approach.

165 citations

Journal ArticleDOI
TL;DR: The experimental results show that the proposed similarity measure between intuitionistic fuzzy sets can overcome the drawbacks of the existing similarity measures.

165 citations


Network Information
Related Topics (5)
Fuzzy logic
151.2K papers, 2.3M citations
96% related
Genetic algorithm
67.5K papers, 1.2M citations
86% related
Artificial neural network
207K papers, 4.5M citations
82% related
Optimization problem
96.4K papers, 2.1M citations
82% related
Support vector machine
73.6K papers, 1.7M citations
82% related
Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023202
2022446
2021696
2020649
2019653
2018733