Fuzzy Sets and SystemsPub Date : 2026-04-15Epub Date: 2025-12-18DOI: 10.1016/j.fss.2025.109732
Guanglei Zhao , Xianyu Liu
{"title":"Fixed-time adaptive fuzzy event-triggered fault-tolerant containment control for nonlinear multi-agent systems","authors":"Guanglei Zhao , Xianyu Liu","doi":"10.1016/j.fss.2025.109732","DOIUrl":"10.1016/j.fss.2025.109732","url":null,"abstract":"<div><div>This work studies the fixed-time event-triggered fault-tolerant containment control problem for nonlinear multi-agent system (MAS) with actuator faults. First, by leveraging fuzzy logic system to approximate unknown nonlinear dynamics, a state observer is designed to estimate unmeasurable state variables. Second, to handle the actuator fault, a novel projection operator compensation mechanism is developed. Furthermore, a fixed-time nonlinear filter design is given to solve the explosion problem and dynamic event-triggering mechanism is proposed to save system resources. Then, combined with dynamic surface control and fuzzy control techniques, fixed-time adaptive fault-tolerant containment control strategy is proposed with rigorous stability analysis, and all followers are able to converge to the convex hull constructed by leaders. In contrast with existing approaches, the main superiority of the proposed containment control strategy is that the projection operator can handle actuator faults more efficiently, multiple parameters of nonlinear filter enhance system flexibility and dynamic threshold in triggering conditions helps to reduce triggering frequency. Finally, simulation results confirm that the proposed method ensures fixed-time convergence of the containment errors.</div></div>","PeriodicalId":55130,"journal":{"name":"Fuzzy Sets and Systems","volume":"529 ","pages":"Article 109732"},"PeriodicalIF":2.7,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145842544","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Fuzzy Sets and SystemsPub Date : 2026-04-15Epub Date: 2025-12-20DOI: 10.1016/j.fss.2025.109742
Wenqi Zhang , Xiang Wu , Hai Zhang , Xiaofeng Ye , Jinde Cao
{"title":"Innovative Razumikhin method for finite-time projective synchronization in fractional delay-coupled fuzzy memristive neural networks with jump mismatches","authors":"Wenqi Zhang , Xiang Wu , Hai Zhang , Xiaofeng Ye , Jinde Cao","doi":"10.1016/j.fss.2025.109742","DOIUrl":"10.1016/j.fss.2025.109742","url":null,"abstract":"<div><div>This paper investigates finite-time projective synchronization (FTP-S) of Caputo fractional multilayer coupled Takagi-Sugeno (T-S) fuzzy delayed memristive neural networks with jumping mismatches. First, a new model combining multilayer coupling and jumping mismatches is proposed to address hierarchical interactions and synaptic weight shifts. Then, a novel Razumikhin finite-time stability lemma for Caputo fractional delayed systems is proposed. Leveraging this lemma and an event-triggered mechanism based on T-S fuzzy rules, sufficient conditions for FTP-S and its settling time are derived. Finally, the absence of Zeno behavior is demonstrated. Notably, the proposed lemma overcomes limitations of existing methods and applies broadly to other fractional delayed systems. Numerical simulations validate the effectiveness of the theory and control strategy.</div></div>","PeriodicalId":55130,"journal":{"name":"Fuzzy Sets and Systems","volume":"529 ","pages":"Article 109742"},"PeriodicalIF":2.7,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145842545","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Fuzzy Sets and SystemsPub Date : 2026-04-15Epub Date: 2025-12-15DOI: 10.1016/j.fss.2025.109724
Weihua Xu, Chongze Zhang
{"title":"RF-WFCCL: A random forest-driven weighted fuzzy concept cognitive learning","authors":"Weihua Xu, Chongze Zhang","doi":"10.1016/j.fss.2025.109724","DOIUrl":"10.1016/j.fss.2025.109724","url":null,"abstract":"<div><div>Weighted Fuzzy Concept Cognitive Learning (WFCCL) improves concept learning by assigning different weights to attributes. However, existing weighting methods mainly rely on fuzzy entropy and fail to effectively handle the noise, uncertainty, and complexity commonly present in real-world data. Moreover, the key threshold <em>λ</em> for generating Advanced Weighted Fuzzy Concepts (AWFC) has not been thoroughly investigated, which may limit the depth of knowledge discovery and the applicability of the model. To address these issues, this paper proposes a Random Forest-Driven Weighted Fuzzy Concept Cognitive Learning (RF-WFCCL) method. The proposed approach leverages random forests to compute attribute importance, thereby making weight allocation more reflective of data characteristics and reducing the influence of noise and uncertainty. In addition, an adaptive optimization algorithm is designed to automatically determine the approximately optimal threshold <span><math><mrow><mover><mi>λ</mi><mo>^</mo></mover><mrow><mo>(</mo><mi>i</mi><mo>)</mo></mrow></mrow></math></span> for generating AWFC, enhancing the accuracy and applicability of concept cognition. Unlike traditional methods, our model not only improves the adaptability of weight allocation but also introduces a data-driven threshold optimization strategy to facilitate knowledge discovery. Finally, extensive experiments on 12 datasets using 12 classification algorithms demonstrate the feasibility and superiority of the proposed method.</div></div>","PeriodicalId":55130,"journal":{"name":"Fuzzy Sets and Systems","volume":"529 ","pages":"Article 109724"},"PeriodicalIF":2.7,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145842543","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Fuzzy Sets and SystemsPub Date : 2026-04-15Epub Date: 2025-12-19DOI: 10.1016/j.fss.2025.109744
Nicolás Marín , Gustavo Rivas-Gervilla , Daniel Sánchez
{"title":"Specificity measures based on fuzzy set inequality","authors":"Nicolás Marín , Gustavo Rivas-Gervilla , Daniel Sánchez","doi":"10.1016/j.fss.2025.109744","DOIUrl":"10.1016/j.fss.2025.109744","url":null,"abstract":"<div><div>Specificity is a measure that tells us to what extent a fuzzy set is a singleton. The variety of application domains of this measure requires different specific forms of calculating it. One way to control the semantic nuances in the way specificity is computed is to generate it from other well-known measures in the Fuzzy Set Theory that have a wide range of evaluation functions with different axiomatics. Following this strategy, in this work we study in depth the inequality measures based on their axiomatics, we establish a method to use them as generators of specificity measures, and we analyze the semantics and the desired properties of specificity measures obtained according to the axioms satisfied by the inequality measures used as generators. As we will see, relevant results have been obtained that relate different families of specificity and inequality measures.</div></div>","PeriodicalId":55130,"journal":{"name":"Fuzzy Sets and Systems","volume":"529 ","pages":"Article 109744"},"PeriodicalIF":2.7,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145841808","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Fuzzy Sets and SystemsPub Date : 2026-04-15Epub Date: 2025-11-15DOI: 10.1016/j.fss.2025.109682
Hua-Peng Zhang , Yao Ouyang
{"title":"Representation and construction of the classes Umin1 and Umax0 of uninorms on a bounded lattice","authors":"Hua-Peng Zhang , Yao Ouyang","doi":"10.1016/j.fss.2025.109682","DOIUrl":"10.1016/j.fss.2025.109682","url":null,"abstract":"<div><div>After mining some inherent properties of the class <span><math><msubsup><mi>U</mi><mrow><mi>min</mi></mrow><mrow><mspace></mspace><mn>1</mn></mrow></msubsup></math></span> of uninorms on a bounded lattice, we present structural representation theorems for uninorms in <span><math><msubsup><mi>U</mi><mrow><mi>min</mi></mrow><mrow><mspace></mspace><mn>1</mn></mrow></msubsup></math></span> by distinguishing two cases. As an application of the representation theorems, we propose several construction methods for uninorms in <span><math><msubsup><mi>U</mi><mrow><mi>min</mi></mrow><mrow><mspace></mspace><mn>1</mn></mrow></msubsup></math></span>. These results can be easily translated into their counterparts for uninorms in <span><math><msubsup><mi>U</mi><mrow><mi>max</mi></mrow><mrow><mspace></mspace><mn>0</mn></mrow></msubsup></math></span> via the Duality Principle in poset theory.</div></div>","PeriodicalId":55130,"journal":{"name":"Fuzzy Sets and Systems","volume":"529 ","pages":"Article 109682"},"PeriodicalIF":2.7,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145842542","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A revised and extended version of McShane-Whitney extensions for fuzzy Lipschitz maps","authors":"Eduardo Jiménez-Fernández , Jesús Rodríguez-López , Aurora Sánchez-Martín-Orozco , Enrique A. Sánchez-Pérez","doi":"10.1016/j.fss.2025.109731","DOIUrl":"10.1016/j.fss.2025.109731","url":null,"abstract":"<div><div>In the paper [E. Jiménez-Fernández, J. Rodríguez-López, E. A. Sánchez-Pérez, Fuzzy Sets and Systems 406 (2021),66-81], a McShane-Whitney extension theorem is presented for real-valued fuzzy Lipschitz maps between fuzzy metric spaces. Specifically, the codomain space is considered as a so-called Euclidean fuzzy metric space <span><math><mrow><mo>(</mo><mi>R</mi><mo>,</mo><msub><mi>M</mi><mrow><mi>ϕ</mi><mo>,</mo><mi>g</mi></mrow></msub><mo>,</mo><mo>*</mo><mo>)</mo><mo>.</mo></mrow></math></span> However, while the function <em>ϕ</em> is only required to be increasing, some results of the paper implicitly assume that <em>ϕ</em> is invertible, even though this is not explicitly stated. We propose here an alternative possibility that only requires <em>ϕ</em> to be also left-continuous.</div></div>","PeriodicalId":55130,"journal":{"name":"Fuzzy Sets and Systems","volume":"529 ","pages":"Article 109731"},"PeriodicalIF":2.7,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145771992","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Fuzzy Sets and SystemsPub Date : 2026-04-15Epub Date: 2025-12-22DOI: 10.1016/j.fss.2025.109745
Ignacio Montes
{"title":"Neighbourhood models induced by the Euclidean distance and the Kullback-Leibler divergence","authors":"Ignacio Montes","doi":"10.1016/j.fss.2025.109745","DOIUrl":"10.1016/j.fss.2025.109745","url":null,"abstract":"<div><div>Robust statistics aims to develop methods that ensure the obtained results remain stable regardless of the quality of the data. A natural approach to enhancing the robustness of a probabilistic model is to consider a neighbourhood around a probability measure with a given radius. These models require two tools: a function for comparing probability measures and the radius measuring the level of imprecision or robustness to be added to the model. With these tools, a neighbourhood or distortion model is defined as the closed ball centred at the probability measure. Many well-known robust models, such as the ϵ-contamination, pari-mutuel model, or constant odds ratio, can be incorporated into the broader framework of neighbourhood models. Additionally, distances between probability measures, such as the total variation or the Kolmogorov distances, determine a neighbourhood model. This paper delves into the neighbourhood models induced by the Euclidean distance applied to the probability mass functions and the Kullback-Leibler divergence. For investigating these models from the perspective of imprecise probability theory, we make use of common optimisation tools with restrictions. We conclude this study providing a comparison study among different neighbourhood models.</div></div>","PeriodicalId":55130,"journal":{"name":"Fuzzy Sets and Systems","volume":"529 ","pages":"Article 109745"},"PeriodicalIF":2.7,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145885601","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Fuzzy Sets and SystemsPub Date : 2026-04-15Epub Date: 2025-12-16DOI: 10.1016/j.fss.2025.109743
Guijie Li , Yang Zhan , Huimin Xue
{"title":"The uncertainty importance measure analysis for fuzzy structural systems based on possibilistic variance","authors":"Guijie Li , Yang Zhan , Huimin Xue","doi":"10.1016/j.fss.2025.109743","DOIUrl":"10.1016/j.fss.2025.109743","url":null,"abstract":"<div><div>To effectively characterize the effects of fuzzy uncertainties on structural systems, this study introduces a novel importance measure termed Possibilistic Variance-based Importance Measure (PVB-IM). By leveraging the High Dimensional Model Representation (HDMR) of the function, we extend the decomposition equation for fuzzy structural systems to establish the PVB-IM. This approach enables the identification of effects of fuzzy variables on system response within fuzzy uncertainties, thereby facilitating the design and optimization for such structural systems. We present a fundamental computational algorithm for PVB-IM using Monte Carlo simulation and propose an efficient algorithm based on the State Dependent Parameter (SDP) method for addressing complex engineering challenges. Through numerical and engineering examples, we validate the applicability and rationale of the PVB-IM, and demonstrate the accuracy and efficiency of the SDP algorithm.</div></div>","PeriodicalId":55130,"journal":{"name":"Fuzzy Sets and Systems","volume":"529 ","pages":"Article 109743"},"PeriodicalIF":2.7,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145842546","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"2-copulas and linear splines","authors":"Fateme Kouchakinejad , Radko Mesiar , Andrea Stupňanová , Radomír Halaš","doi":"10.1016/j.fss.2025.109746","DOIUrl":"10.1016/j.fss.2025.109746","url":null,"abstract":"<div><div>The notion of spline linearity for aggregation functions is recalled. We then focus on linear spline 2-copulas and various constructions of 2-copulas to investigate the impact of these constructions on spline linearity. Moreover, associative copulas that are linear splines are discussed. Some other methods that yield linear spline copulas are also presented and illustrated.</div></div>","PeriodicalId":55130,"journal":{"name":"Fuzzy Sets and Systems","volume":"529 ","pages":"Article 109746"},"PeriodicalIF":2.7,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145842547","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Fuzzy Sets and SystemsPub Date : 2026-04-15Epub Date: 2025-12-05DOI: 10.1016/j.fss.2025.109715
Lei Jia , Weibao Xiong , Yiwei Li
{"title":"A transition-state-based zeroing neurodynamics method for solving non-fully/fully LR fuzzy Sylvester matrix equation","authors":"Lei Jia , Weibao Xiong , Yiwei Li","doi":"10.1016/j.fss.2025.109715","DOIUrl":"10.1016/j.fss.2025.109715","url":null,"abstract":"<div><div>Considering that traditional methods encounter theoretical infeasibility and computational complexity when solving fuzzy Sylvester matrix equations, by leveraging the advantages of zeroing neurodynamics approach for calculation problems, this paper proposes a transition-state-based zeroing neurodynamic (TSBZN) method to address non-fully/fully LR fuzzy Sylvester matrix equation (i.e., NLFSM and FLFSM equations). Based on the element-wise forms of the NLFSM and FLFSM equations which are mainly derived from LR fuzzy numbers and relative operations, two TSBZN models are constructed by defining the mass matrix. At the same time, a novel transition-state-based activation function (TSBAF) is designed and applied to enhance the performance of TSBZN models. In the TSBAF, a transition state parameter is introduced and divides the convergence process into two phases: a traveling phase and a reaching phase. The traveling phase ensures that the TSBZN models are continuously attracted to the transition state and rapidly converges to it, while the reaching phase guarantees stability and precise control. Consequently, the TSBZN models activated by the TSBAF possess superior fixed-time convergence with stricter upper bound on settling time, ensuring that the exact solutions of the NLFSM and FLFSM equations can be obtained within a fixed time. The global stability and fixed-time convergence of these two TSBZN models are theoretically proven, with predefined-time convergence further guaranteed by a corollary. Serial numerical experiments validate the accuracy, efficiency, and superiority of the TSBZN models, and an image denoising application also shows their practical value.</div></div>","PeriodicalId":55130,"journal":{"name":"Fuzzy Sets and Systems","volume":"529 ","pages":"Article 109715"},"PeriodicalIF":2.7,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145885600","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}