Fuzzy Sets and SystemsInternational Journal in Information Science and Engineering Short Title: Fuzzy Sets Syst. Publisher: Elsevier (North-Holland), Amsterdam ISSN: 0165-0114 Online: http://www.sciencedirect.com/science/journal/01650114 Comments: Journal Documents Indexed: 7,579 Publications (since 1978) References Indexed: 7,285 Publications with 169,540 References. all top 5 Latest Issues 456 (2023) 455 (2023) 454 (2023) 453 (2023) 452 (2023) 451 (2022) 450 (2022) 449 (2022) 448 (2022) 447 (2022) 446 (2022) 445 (2022) 442 (2022) 441 (2022) 440 (2022) 439 (2022) 438 (2022) 437 (2022) 436 (2022) 435 (2022) 434 (2022) 433 (2022) 432 (2022) 431 (2022) 430 (2022) 429 (2022) 428 (2022) 427 (2022) 426 (2022) 425 (2021) 424 (2021) 423 (2021) 422 (2021) 421 (2021) 420 (2021) 419 (2021) 418 (2021) 417 (2021) 416 (2021) 415 (2021) 414 (2021) 413 (2021) 412 (2021) 411 (2021) 410 (2021) 409 (2021) 408 (2021) 407 (2021) 406 (2021) 405 (2021) 404 (2021) 403 (2021) 402 (2021) 401 (2020) 400 (2020) 399 (2020) 398 (2020) 397 (2020) 396 (2020) 395 (2020) 394 (2020) 393 (2020) 392 (2020) 391 (2020) 390 (2020) 389 (2020) 388 (2020) 387 (2020) 386 (2020) 385 (2020) 384 (2020) 383 (2020) 382 (2020) 381 (2020) 380 (2020) 379 (2020) 378 (2020) 377 (2019) 376 (2019) 375 (2019) 374 (2019) 373 (2019) 372 (2019) 371 (2019) 370 (2019) 369 (2019) 368 (2019) 367 (2019) 366 (2019) 365 (2019) 364 (2019) 363 (2019) 362 (2019) 361 (2019) 360 (2019) 359 (2019) 358 (2019) 357 (2019) 356 (2019) 355 (2019) ...and 712 more Volumes all top 5 Authors 141 Mesiar, Radko 88 De Baets, Bernard 71 Buckley, James J. 71 Pedrycz, Witold 56 Wu, Congxin 55 Kerre, Etienne E. 52 Bustince Sola, Humberto 49 Yager, Ronald R. 47 Dubois, Didier 45 Prade, Henri M. 44 Hong, Dug Hun 43 Fang, Jinxuan 40 Kandel, Abraham 39 Pap, Endre 37 Morsi, Nehad Nashaat 37 Sakawa, Masatoshi 35 Klement, Erich Peter 35 Novák, Vilém 35 Shi, Fu-Gui 34 Torrens, Joan 33 Liu, Huawen 33 Zhang, Dexue 32 Tong, Shaocheng 31 Hu, Baoqing 29 Mordeson, John N. 28 Fang, Jinming 28 Fernández-Sánchez, Juan 26 Gottwald, Siegfried 26 Höhle, Ulrich 26 Šešelja, Branimir 26 Tepavčević, Andreja 26 Wang, Zhudeng 25 Beliakov, Gleb 25 Sugeno, Michio 24 Baczynski, Michal 24 Demirci, Mustafa 24 Inuiguchi, Masahiro 24 Jäger, Gunther 24 Kolesárová, Anna 24 Medina, Jesús 23 Fodor, János C. 23 Kumar, Rajesh 23 Verdegay, José Luis 22 Ajmal, Naseem 22 Chalco-Cano, Yurilev 22 Gutiérrez García, Javier 22 Herrera, Francisco 22 Li, Shenggang 22 Murofushi, Toshiaki 22 Ouyang, Yao 22 Warner, Mary Wynne 21 Dvurečenskij, Anatolij 21 Ma, Ming 21 Rodabaugh, Stephen Ernest 21 Solovyov, Sergey A. 21 Su, Yong 21 Úbeda-Flores, Manuel 21 Vila, Maria Amparo 21 Yoshida, Yuji 20 Calvo, Tomasa 20 De Meyer, Hans E. 20 Delgado, Miguel Ángel 20 Jenei, Sándor 20 Lowen, Robert 20 Ovchinnikov, Sergei V. 20 Perfilieva, Irina G. 20 Romaguera Bonilla, Salvador 20 Wang, Guojun 20 Zhao, Bin 19 Di Nola, Antonio 19 Godo, Lluís 19 Li, Jun 19 Lodwick, Weldon Alexander 19 Mesiarová-Zemánková, Andrea 18 Czogała, Ernest 18 De Barros, Laécio Carvalho 18 Gregori, Valentín 18 Jayaram, Balasubramaniam 18 Montes, Susana 18 Nanda, Sudarsan 18 Recasens, Jordi 18 Román-Flores, Heriberto E. 18 Wang, Zhenyuan 18 Zhang, Deli 17 Bedregal, Benjamín René Callejas 17 Chang, Shih-Sen 17 Chen, Degang 17 de Prada Vicente, María Angeles 17 Fernández Fernández, Francisco Javier 17 Holcapek, Michal 17 Li, Hongxing 17 Ruiz-Aguilera, Daniel 17 Voxman, William L. 17 Zhang, Huapeng 16 Chen, Bing 16 Durante, Fabrizio 16 Gong, Zengtai 16 Montero, Javier 16 Yue, Yueli 15 Feng, Yuhu ...and 6,032 more Authors all top 5 Fields 2,533 Mathematical logic and foundations (03-XX) 1,269 Computer science (68-XX) 1,049 General topology (54-XX) 900 Systems theory; control (93-XX) 678 Operations research, mathematical programming (90-XX) 624 Game theory, economics, finance, and other social and behavioral sciences (91-XX) 556 Measure and integration (28-XX) 550 Order, lattices, ordered algebraic structures (06-XX) 462 Statistics (62-XX) 404 Information and communication theory, circuits (94-XX) 286 Real functions (26-XX) 285 Probability theory and stochastic processes (60-XX) 200 Group theory and generalizations (20-XX) 175 Category theory; homological algebra (18-XX) 161 Linear and multilinear algebra; matrix theory (15-XX) 144 Ordinary differential equations (34-XX) 135 Functional analysis (46-XX) 118 Numerical analysis (65-XX) 114 Biology and other natural sciences (92-XX) 93 General and overarching topics; collections (00-XX) 87 General algebraic systems (08-XX) 84 Associative rings and algebras (16-XX) 72 Difference and functional equations (39-XX) 69 Combinatorics (05-XX) 58 Operator theory (47-XX) 52 Calculus of variations and optimal control; optimization (49-XX) 45 Dynamical systems and ergodic theory (37-XX) 42 Quantum theory (81-XX) 40 History and biography (01-XX) 34 Commutative algebra (13-XX) 31 Approximations and expansions (41-XX) 27 Topological groups, Lie groups (22-XX) 23 Convex and discrete geometry (52-XX) 22 Integral equations (45-XX) 20 Partial differential equations (35-XX) 18 Integral transforms, operational calculus (44-XX) 17 Field theory and polynomials (12-XX) 14 Mechanics of particles and systems (70-XX) 11 Geometry (51-XX) 10 Functions of a complex variable (30-XX) 10 Sequences, series, summability (40-XX) 8 Algebraic topology (55-XX) 7 Geophysics (86-XX) 5 Number theory (11-XX) 5 Algebraic geometry (14-XX) 4 Manifolds and cell complexes (57-XX) 3 Nonassociative rings and algebras (17-XX) 3 Global analysis, analysis on manifolds (58-XX) 3 Mechanics of deformable solids (74-XX) 2 Harmonic analysis on Euclidean spaces (42-XX) 2 Statistical mechanics, structure of matter (82-XX) 1 Abstract harmonic analysis (43-XX) 1 Fluid mechanics (76-XX) 1 Classical thermodynamics, heat transfer (80-XX) 1 Relativity and gravitational theory (83-XX) Publications by Year all cited Publications top 5 cited Publications Citations contained in zbMATH Open 6,543 Publications have been cited 100,398 times in 27,707 Documents Cited by ▼ Year ▼ Intuitionistic fuzzy sets. Zbl 0631.03040 Atanassov, Krassimir T. 1,810 1986 Fuzzy sets as a basis for a theory of possibility. Zbl 0377.04002 Zadeh, L. A. 1,631 1978 Fuzzy programming and linear programming with several objective functions. Zbl 0364.90065 Zimmermann, H.-J. 627 1978 Fuzzy differential equations. Zbl 0646.34019 Kaleva, Osmo 584 1987 Interval valued intuitionistic fuzzy sets. Zbl 0674.03017 Atanassov, K.; Gargov, G. 482 1989 On some results in fuzzy metric spaces. Zbl 0843.54014 George, A.; Veeramani, P. 468 1994 Elementary fuzzy calculus. Zbl 0626.26014 Goetschel, Roy jun.; Voxman, William 458 1986 Monoidal t-norm based logic: Towards a logic for left-continuous t-norms. Zbl 0994.03017 Esteva, Francesc; Godo, Lluís 395 2001 Absorbent tuples of aggregation operators. Zbl 1123.68124 Beliakov, G.; Calvo, T.; Pradera, A. 384 2007 Generalizations of the differentiability of fuzzy-number-valued functions with applications to fuzzy differential equations. Zbl 1061.26024 Bede, Barnabás; Gal, Sorin G. 381 2005 Uninorm aggregation operators. Zbl 0871.04007 Yager, Ronald R.; Rybalov, Alexander 351 1996 Decision-making with a fuzzy preference relation. Zbl 0396.90004 Orlovsky, S. A. 316 1978 Stability analysis and design of fuzzy control systems. Zbl 0758.93042 Tanaka, Kazuo; Sugeno, Michio 307 1992 On fuzzy metric spaces. Zbl 0558.54003 Kaleva, Osmo; Seikkala, Seppo 284 1984 Fixed points in fuzzy metric spaces. Zbl 0664.54032 Grabiec, Mariusz 276 1988 On the fuzzy initial value problem. Zbl 0643.34005 Seikkala, Seppo 268 1987 Fuzzy preference orderings in group decision making. Zbl 0567.90002 Tanino, Tetsuzo 256 1984 Toward a theory of fuzzy information granulation and its centrality in human reasoning and fuzzy logic. Zbl 0988.03040 Zadeh, Lotfi A. 243 1997 Generalized differentiability of fuzzy-valued functions. Zbl 1314.26037 Bede, Barnabás; Stefanini, Luciano 241 2013 A review of some methods for ranking fuzzy subsets. Zbl 0567.90056 Bortolan, G.; Degani, R. 236 1985 A comparative study of fuzzy rough sets. Zbl 1004.03043 Radzikowska, Anna Maria; Kerre, Etienne E. 230 2002 Fuzzy invariant subgroups and fuzzy ideals. Zbl 0488.20005 Liu, Wang-jin 229 1982 A generalization of Hukuhara difference and division for interval and fuzzy arithmetic. Zbl 1188.26019 Stefanini, Luciano 210 2010 The mean value of a fuzzy number. Zbl 0634.94026 Dubois, Didier; Prade, Henri 204 1987 Extensions of the TOPSIS for group decision-making under fuzzy environment. Zbl 0963.91030 Chen, Chen-Tung 200 2000 On the relationship between some extensions of fuzzy set theory. Zbl 1013.03065 Deschrijver, Glad; Kerre, Etienne E. 200 2003 Distances between intuitionistic fuzzy sets. Zbl 0961.03050 Szmidt, Eulalia; Kacprzyk, Janusz 196 2000 Families of OWA operators. Zbl 0790.94004 Yager, Ronald R. 196 1993 \(k\)-order additive discrete fuzzy measures and their representation. Zbl 0927.28014 Grabisch, Michel 195 1997 Fuzzy sets in a approximate reasoning. I: Inference with possibility distributions. Zbl 0722.03017 Dubois, Didier; Prade, Henri 190 1991 A fuzzy extension of Saaty’s priority theory. Zbl 0528.90054 van Laarhoven, P. J. M.; Pedrycz, W. 189 1983 Direct approach processes in group decision making using linguistic OWA operators. Zbl 0870.90007 Herrera, F.; Herrera-Viedma, E.; Verdegay, J. L. 188 1996 More on intuitionistic fuzzy sets. Zbl 0685.03037 Atanassov, Krassimir T. 184 1989 Linguistic decision analysis: steps for solving decision problems under linguistic information. Zbl 1073.91528 Herrera, F.; Herrera-Viedma, E. 177 2000 New operations defined over the intuitionistic fuzzy sets. Zbl 0824.04004 Atanassov, Krassimir T. 177 1994 Fuzzy variables. Zbl 0383.03038 Nahmias, Steven 177 1978 On fixed-point theorems in fuzzy metric spaces. Zbl 0995.54046 Gregori, Valentín; Sapena, Almanzor 174 2002 On the structure of F-indistinguishability operators. Zbl 0609.04002 Valverde, L. 174 1985 Latent connectives in human decision making. Zbl 0435.90009 Zimmermann, H.-J.; Zysno, P. 173 1980 On possibilistic mean value and variance of fuzzy numbers. Zbl 1016.94047 Carlsson, Christer; Fullér, Robert 169 2001 The functional equations of Frank and Alsina for uninorms and nullnorms. Zbl 0977.03026 Calvo, Tomasa; De Baets, Bernard; Fodor, János 164 2001 Ranking fuzzy numbers with integral value. Zbl 1229.03043 Liou, Tian-Shy; Wang, Mao Jiun J. 162 1992 Interval valued fuzzy sets based on normal forms. Zbl 0618.94020 Turksen, I. B. 162 1986 A method of inference in approximate reasoning based on interval-valued fuzzy sets. Zbl 0635.68103 Gorzałczany, Marian B. 160 1987 Contrapositive symmetry of fuzzy implications. Zbl 0845.03007 Fodor, János C. 159 1995 Reasonable properties for the ordering of fuzzy quantities. I. Zbl 0971.03054 Wang, Xuzhu; Kerre, Etienne E. 159 2001 On a general class of fuzzy connectives. Zbl 0443.04008 Yager, Ronald R. 156 1980 Fuzzy topological vector spaces. II. Zbl 0555.46006 Katsaras, A. K. 153 1984 Fuzzy differential equations. Zbl 0947.34049 Buckley, James J.; Feuring, Thomas 153 2000 Structure identification of fuzzy model. Zbl 0652.93010 Sugeno, M.; Kang, G. T. 152 1988 The Cauchy problem for fuzzy differential equations. Zbl 0696.34005 Kaleva, Osmo 152 1990 Fuzzy linear systems. Zbl 0929.15004 Friedman, Menahem; Ma, Ming; Kandel, Abraham 150 1998 On some results of analysis for fuzzy metric spaces. Zbl 0917.54010 George, A.; Veeramani, P. 148 1997 Handling multicriteria fuzzy decision-making problems based on vague set theory. Zbl 0845.90078 Chen, Shyi-Ming; Tan, Jiann-Mean 147 1994 Possibilistic linear programming: A brief review of fuzzy mathematical programming and a comparison with stochastic programming in portfolio selection problem. Zbl 0938.90074 Inuiguchi, Masahiro; Ramík, Jaroslav 147 2000 Axiomatics for fuzzy rough sets. Zbl 0938.03085 Morsi, Nehad N.; Yakout, M. M. 146 1998 Vague sets are intuitionistic fuzzy sets. Zbl 0871.04006 Bustince, H.; Burillo, P. 146 1996 Fuzzy hierarchical analysis. Zbl 0602.90002 Buckley, J. J. 144 1985 Towards fuzzy differential calculus. III: Differentiation. Zbl 0499.28009 Dubois, Didier; Prade, Henri 143 1982 Triangular norms on product lattices. Zbl 0935.03060 De Baets, Bernard; Mesiar, Radko 142 1999 A new approach for ranking fuzzy numbers by distance method. Zbl 0929.91009 Cheng, Ching-Hsue 141 1998 Entropy for intuitionistic fuzzy sets. Zbl 1045.94007 Szmidt, Eulalia; Kacprzyk, Janusz 139 2001 Fuzzy neighborhood spaces. Zbl 0487.54008 Lowen, R. 137 1982 Ranking fuzzy numbers with maximizing set and minimizing set. Zbl 0618.90047 Chen, Shan-Huo 137 1985 A new approach for fuzzy topology. I. Zbl 0718.54017 Ying, Mingsheng 137 1991 Finite dimensional fuzzy normed linear space. Zbl 0770.46038 Felbin, Clementina 137 1992 Ranking and defuzzification methods based on area compensation. Zbl 0886.94025 Fortemps, Philippe; Roubens, Marc 137 1996 Entropy on intuitionistic fuzzy sets and on interval-valued fuzzy sets. Zbl 0872.94061 Burillo, P.; Bustince, H. 136 1996 Fuzzy integral in multicriteria decision making. Zbl 0845.90001 Grabisch, Michel 134 1995 Multicriteria fuzzy decision-making problems based on vague set theory. Zbl 0963.91031 Hong, Dug Hun; Choi, Chang-Hwan 133 2000 Fuzzy transforms: theory and applications. Zbl 1092.41022 Perfilieva, Irina 133 2006 Metric spaces of fuzzy sets. Zbl 0704.54006 Diamond, Phil; Kloeden, Peter 133 1990 Theory of topological molecular lattices. Zbl 0783.54032 Wang, Guojun 131 1992 Chance constrained programming with fuzzy parameters. Zbl 0923.90141 Liu, Baoding; Iwamura, Kakuzo 129 1998 Operators over interval valued intuitionistic fuzzy sets. Zbl 0844.04001 Atanassov, Krassimir T. 128 1994 Fuzzy power sets and fuzzy implication operators. Zbl 0433.03013 Bandler, Wyllis; Kohout, Ladislav 124 1980 Numerical solutions of fuzzy differential and integral equations. Zbl 0931.65076 Friedman, Menahem; Ma, Ming; Kandel, Abraham 123 1999 Asymptotically necessary and sufficient conditions for stability and performance in fuzzy control: applications of Polya’s theorem. Zbl 1133.93348 Sala, Antonio; Ariño, Carlos 121 2007 A general concept of fuzzy connectives, negations and implications based on t-norms and t-conorms. Zbl 0543.03013 Weber, Siegfried 120 1983 An application of intuitionistic fuzzy sets in medical diagnosis. Zbl 0980.92013 De, Supriya Kumar; Biswas, Ranjit; Roy, Akhil Ranjan 119 2001 Stability analysis and synthesis of nonlinear time-delay systems via linear Takagi-Sugeno fuzzy models. Zbl 1002.93051 Cao, Yong-Yan; Frank, P. M. 117 2001 Observer-based fuzzy adaptive control for strict-feedback nonlinear systems. Zbl 1175.93135 Tong, Shaocheng; Li, Yongming 117 2009 Ranking fuzzy numbers based on decomposition principle and signed distance. Zbl 1179.62031 Yao, Jing-Shing; Wu, Kweimei 116 2000 On Henstock integral of fuzzy-number-valued functions. I. Zbl 0984.28010 Wu, Congxin; Gong, Zengtai 116 2001 Fuzzy linear programming problems with fuzzy numbers. Zbl 0546.90062 Tanaka, H.; Asai, K. 115 1984 The role of fuzzy logic in the management of uncertainty in expert systems. Zbl 0553.68049 Zadeh, L. A. 115 1983 Fuzzy data analysis by possibilistic linear models. Zbl 0633.93060 Tanaka, Hideo 114 1987 Some properties of fuzzy metric spaces. Zbl 0985.54007 Gregori, Valentin; Romaguera, Salvador 114 2000 The expected value of a fuzzy number. Zbl 0755.60004 Heilpern, Stanisław 114 1992 Integrating three representation models in fuzzy multipurpose decision making based on fuzzy preference relations. Zbl 0932.91012 Chiclana, F.; Herrera, F.; Herrera-Viedma, E. 113 1998 Separation axioms in fuzzy topological spaces. Zbl 0421.54006 Hutton, Bruce; Reilly, Ivan 113 1980 Fuzzy preorder and fuzzy topology. Zbl 1118.54008 Lai, Hongliang; Zhang, Dexue 112 2006 On a canonical representation of fuzzy numbers. Zbl 0916.04004 Delgado, M.; Vila, M. A.; Voxman, W. 111 1998 Integrating multiplicative preference relations in a multipurpose decision-making model based on fuzzy preference relations. Zbl 1098.90523 Chiclana, F.; Herrera, F.; Herrera-Viedma, E. 111 2001 \((\in,\in\vee\;q)\)-fuzzy subgroup. Zbl 0870.20055 Bhakat, S. K.; Das, P. 111 1996 Entropy, distance measure and similarity measure of fuzzy sets and their relations. Zbl 0782.94026 Liu, Xuecheng 110 1992 Automorphisms, negations and implication operators. Zbl 1010.03017 Bustince, H.; Burillo, P.; Soria, F. 110 2003 Reasonable properties for the ordering of fuzzy quantities. II. Zbl 0971.03055 Wang, Xuzhu; Kerre, Etienne E. 108 2001 Inequality relation between fuzzy numbers and its use in fuzzy optimization. Zbl 0574.04005 Ramík, Jaroslav; Římánek, Josef 108 1985 Group decision making with a fuzzy linguistic majority. Zbl 0604.90012 Kacprzyk, Janusz 108 1986 Fuzzy-based dynamic event triggering formation control for nonstrict-feedback nonlinear MASs. Zbl 1522.93100 Cao, Liang; Yao, Deyin; Li, Hongyi; Meng, Wei; Lu, Renquan 7 2023 Event-triggered adaptive fuzzy control for stochastic nonlinear time-delay systems. Zbl 1522.93172 Liu, Yongchao; Zhu, Qidan; Fan, Xing 4 2023 Large-scale group decision-making with incomplete fuzzy preference relations: the perspective of ordinal consistency. Zbl 1522.91090 Yuan, Rong; Wu, Zhibin; Tu, Jiancheng 3 2023 Fault-tolerant control for T-S fuzzy systems with an aperiodic adaptive event-triggered sampling. Zbl 1522.93106 Liu, Yajuan; Zhao, Xueyun; Park, Ju H.; Fang, Fang 2 2023 Dynamic event-triggered security control for networked T-S fuzzy system with non-uniform sampling. Zbl 1522.93113 Tan, Yushun; Yuan, Ye; Xie, Xiangpeng; Niu, Ben 2 2023 Approximate positional analysis of fuzzy social networks. Zbl 1522.91190 Micić, Ivana; Stanimirović, Stefan; Jančić, Zorana 2 2023 Orthopartitions and possibility distributions. Zbl 1522.68551 Boffa, Stefania; Ciucci, Davide 2 2023 Logical entropy and aggregation of fuzzy orthopartitions. Zbl 1522.68552 Boffa, Stefania; Ciucci, Davide 2 2023 Reasoning with fuzzy and uncertain evidence using epistemic random fuzzy sets: general framework and practical models. Zbl 1522.03247 Denœux, Thierry 1 2023 Some notes on the switching points for the generalized Hukuhara differentiability of interval-valued functions. Zbl 1522.26027 Qiu, Dong; Yu, Yan 1 2023 Suboptimal control of linear fuzzy systems. Zbl 1522.34017 Zarei, H.; Khastan, A.; Rodríguez-López, R. 1 2023 A novel perspective on the inconsistency indices of reciprocal relations and pairwise comparison matrices. Zbl 1522.91076 Bortot, Silvia; Brunelli, Matteo; Fedrizzi, Michele; Marques Pereira, Ricardo Alberto 1 2023 Abstract aggregation functions and social choice. Zbl 1522.91106 Candeal, Juan C. 1 2023 Reflectors to quantales. Zbl 1522.06031 Zhang, Xia; Paseka, Jan; Feng, Jianjun; Chen, Yudong 1 2023 Constructing \(Q\)-algebras from \(Q\)-modules. Zbl 1522.06030 Han, Shengwei 1 2023 A first polynomial non-clausal class in many-valued logic. Zbl 1522.03099 Imaz, Gonzalo E. 1 2023 The variety of modal weak Gödel algebras. Zbl 1522.06016 Celani, Sergio A.; Nagy, Agustín L.; San Martín, Hernán J. 1 2023 Characterizations for the migrativity of continuous t-conorms over fuzzy implications. Zbl 1522.03086 Pan, Deng; Zhou, Hongjun; Yan, Xinxin 1 2023 Finite-time stability of fractional-order fuzzy cellular neural networks with time delays. Zbl 1522.93156 Du, Feifei; Lu, Jun-Guo 8 2022 Constructing overlap and grouping functions on complete lattices by means of complete homomorphisms. Zbl 1522.03290 Wang, Yuntian; Hu, Bao Qing 6 2022 Almost periodic synchronization of quaternion-valued fuzzy cellular neural networks with leakage delays. Zbl 1522.93151 Wang, Pan; Li, Xuechen; Wang, Nan; Li, Yuanyuan; Shi, Kaibo; Lu, Jianquan 5 2022 Calculus for linearly correlated fuzzy number-valued functions. Zbl 1522.26028 Shen, Yonghong 5 2022 On ordinal sums of overlap and grouping functions on complete lattices. Zbl 1522.03291 Wang, Yuntian; Hu, Bao Qing 5 2022 Towards interval uncertainty propagation control in bivariate aggregation processes and the introduction of width-limited interval-valued overlap functions. Zbl 1522.03245 da Cruz Asmus, Tiago; Pereira Dimuro, Graçaliz; Bedregal, Benjamín; Sanz, José Antonio; Mesiar, Radko; Bustince, Humberto 4 2022 Constructions of quasi-overlap functions and their generalized forms on bounded partially ordered sets. Zbl 1522.06002 Qiao, Junsheng 4 2022 Regular summability methods in the approximation by max-min operators. Zbl 1522.41009 Gökçer, Türkan Yeliz; Duman, Oktay 4 2022 The fuzzy fractional SIQR model of computer virus propagation in wireless sensor network using Caputo Atangana-Baleanu derivatives. Zbl 1522.68075 Dong, Nguyen Phuong; Long, Hoang Viet; Giang, Nguyen Long 4 2022 Fuzzy linear singular differential equations under granular differentiability concept. Zbl 1522.34012 Najariyan, Marzieh; Pariz, Naser; Vu, Ho 4 2022 Further characterization of uninorms on bounded lattices. Zbl 1522.03285 Sun, Xiang-Rong; Liu, Hua-Wen 4 2022 Uninorms on bounded lattices constructed by t-norms and t-subconorms. Zbl 1522.03258 Hua, Xiu-juan; Ji, Wei 4 2022 A representation of nullnorms on a bounded lattice in terms of beam operations. Zbl 1522.03303 Zhang, Hua-Peng; Wang, Zhudeng; Ouyang, Yao; De Baets, Bernard 4 2022 Hidden Markov model-based asynchronous quantized sampled-data control for fuzzy nonlinear Markov jump systems. Zbl 1522.93173 Wu, Tao; Xiong, Lianglin; Cao, Jinde; Park, Ju H. 4 2022 Some generalizations of Opial type inequalities for interval-valued functions. Zbl 1522.26035 Zhao, Dafang; An, Tianqing; Ye, Guoju; Liu, Wei 4 2022 On a pair of fuzzy dominated mappings on closed ball in the multiplicative metric space with applications. Zbl 1522.54064 Rasham, Tahair; Shabbir, Muhammad Sajjad; Agarwal, Praveen; Momani, Shaher 4 2022 Random-term-absent addition-min fuzzy relation inequalities and their lexicographic minimum solutions. Zbl 1522.90292 Yang, Xiao-Peng 3 2022 Bipolar equations on complete distributive symmetric residuated lattices: the case of a join-irreducible right-hand side. Zbl 1522.06015 Cornejo, M. Eugenia; Lobo, David; Medina, Jesús; De Baets, Bernard 3 2022 Pseudo-integral and generalized Choquet integral. Zbl 1522.28038 Zhang, Deli; Mesiar, Radko; Pap, Endre 3 2022 Multivariate imprecise Sklar type theorems. Zbl 1522.62036 Omladič, Matjaž; Stopar, Nik 3 2022 First-order linear fuzzy differential equations on the space of linearly correlated fuzzy numbers. Zbl 1522.34013 Shen, Yonghong 3 2022 Event-based adaptive fuzzy fixed-time control for nonlinear interconnected systems with non-affine nonlinear faults. Zbl 1522.93110 Shao, Xinfeng; Ye, Dan 3 2022 Event-based asynchronous dissipative filtering for fuzzy nonhomogeneous Markov switching systems with variable packet dropouts. Zbl 1522.93180 Zhou, Xia; Cheng, Jun; Cao, Jinde; Park, Ju H. 3 2022 More relaxed stability analysis and positivity analysis for positive polynomial fuzzy systems via membership functions dependent method. Zbl 1522.93139 Han, Meng; Lam, H. K.; Liu, Fucai; Tang, Yinggan 3 2022 Adaptive neural asymptotic control for uncertain nonlinear multiagent systems with a fuzzy dead zone constraint. Zbl 1522.93089 Huang, Chengjie; Liu, Zhi; Chen, C. L. Philip; Zhang, Yun 3 2022 System identification of fuzzy relation matrix models by semi-tensor product operations. Zbl 1522.93107 Lyu, Hong L.; Wang, Wilson; Liu, Xiao P. 2 2022 Characterization of a class of fuzzy implication solutions to the law of importation. Zbl 1522.03089 Zhou, Hongjun; Song, Yingying 2 2022 \(n\)-dimensional observables on \(k\)-perfect MV-algebras and \(k\)-perfect effect algebras. I: Characteristic points. Zbl 1522.03335 Dvurečenskij, Anatolij; Lachman, Dominik 2 2022 Redefined fuzzy rough set models in fuzzy \(\beta \)-covering group approximation spaces. Zbl 1522.68590 Zhang, Kai; Dai, Jianhua 2 2022 Varieties of K-lattices. Zbl 1522.06008 Aglianò, Paolo; Marcos, Miguel Andrés 2 2022 Characterization and computation of approximate bisimulations for fuzzy automata. Zbl 1522.68279 Micić, Ivana; Nguyen, Linh Anh; Stanimirović, Stefan 2 2022 Monteiro’s algebraic notion of maximal consistent theory for Tarskian logics. Zbl 1522.03344 Figallo-Orellano, Aldo; Slagter, Juan Sebastián 2 2022 On the ordinal sum of fuzzy implications: new results and the distributivity over a class of overlap and grouping functions. Zbl 1522.03068 Cao, Meng; Hu, Bao Qing 2 2022 Measures of conflict, basic axioms and their application to the clusterization of a body of evidence. Zbl 1522.68553 Bronevich, Andrey G.; Lepskiy, Alexander E. 2 2022 Some properties of double shuffles of bivariate copulas and (extreme) copulas invariant with respect to Lüroth double shuffles. Zbl 1522.62032 Griessenberger, Florian; Fernández Sánchez, Juan; Trutschnig, Wolfgang 2 2022 Random generation of \(k\)-interactive capacities. Zbl 1522.91075 Beliakov, Gleb; Cabrerizo, Francisco Javier; Herrera-Viedma, Enrique; Wu, Jian-Zhang 2 2022 Characterization of idempotent \(n\)-uninorms. Zbl 1522.03271 Mesiarová-Zemánková, Andrea 2 2022 Some new results on the migrativity of uninorms over overlap and grouping functions. Zbl 1522.03311 Zhu, Kuanyun; Wang, Jingru; Yang, Yongwei 2 2022 Logical characterizations of fuzzy bisimulations in fuzzy modal logics over residuated lattices. Zbl 1522.03085 Nguyen, Linh Anh 2 2022 Algebraic semantics for the minimum many-valued modal logic over Ł\(_n\). Zbl 1522.03061 Busaniche, Manuela; Cordero, Penélope; Rodriguez, Ricardo Oscar 2 2022 Event-generator-based \(H_\infty\) control of fuzzy distributed parameter systems. Zbl 1522.93105 Ji, Huihui; Cui, Baotong 2 2022 Optimality conditions for fuzzy optimization in several variables under generalized differentiability. Zbl 1522.90284 Qiu, Dong; Ouyang, Chenxi 2 2022 Fuzzy group identification problems. Zbl 1522.91109 Fioravanti, Federico; Tohmé, Fernando 2 2022 Games in possibility capacities with payoff expressed by fuzzy integral. Zbl 1522.91023 Radul, Taras 2 2022 New metric-based derivatives for fuzzy functions and some of their properties. Zbl 1522.26025 Khastan, A.; Rodríguez-López, R.; Shahidi, M. 2 2022 New results for T-S fuzzy systems with hybrid communication delays. Zbl 1522.93099 Cai, Xiao; Shi, Kaibo; She, Kun; Zhong, Shouming; Wang, Jun; Yan, Huaicheng 2 2022 Optimality conditions for fuzzy optimization problems under granular convexity concept. Zbl 1522.90293 Zhang, Jianke; Chen, Xiaoyi; Li, Lifeng; Ma, Xiaojue 2 2022 Idempotent uninorms on a complete chain. Zbl 1522.03276 Ouyang, Yao; Zhang, Hua-Peng; Wang, Zhudeng; De Baets, Bernard 2 2022 Ordinal sums: from triangular norms to bi- and multivariate copulas. Zbl 1522.03249 Durante, Fabrizio; Klement, Erich Peter; Saminger-Platz, Susanne; Sempi, Carlo 2 2022 Granular computing: an augmented scheme of degranulation through a modified partition matrix. Zbl 1522.68586 Xu, Kaijie; Pedrycz, Witold; Li, Zhiwu 1 2022 Discrete IV \(d_G\)-Choquet integrals with respect to admissible orders. Zbl 1522.28035 Takáč, Zdenko; Uriz, Mikel; Galar, Mikel; Paternain, Daniel; Bustince, Humberto 1 2022 Aggregation on lattices isomorphic to the lattice of closed subintervals of the real unit interval. Zbl 1522.03273 Mesiar, Radko; Kolesárová, Anna; Senapati, Tapan 1 2022 Lifting associative operations on subposets of a complete lattice. Zbl 1522.06011 Dan, Yexing; De Baets, Bernard 1 2022 Best-possible bounds on the sets of copulas and quasi-copulas with given curvilinear sections. Zbl 1522.62041 Zou, Wei; Sun, Liulei; Xie, Jiehua 1 2022 \(n\)-dimensional observables on \(k\)-perfect MV-algebras and \(k\)-perfect effect algebras. II: One-to-one correspondence. Zbl 1522.03336 Dvurečenskij, Anatolij; Lachman, Dominik 1 2022 A category of complete residuated lattice-value neighborhood groups. Zbl 1522.18008 Li, Lingqiang; Jin, Qiu 1 2022 Varieties of bounded K-lattices. Zbl 1522.06009 Aglianò, Paolo; Marcos, Miguel Andrés 1 2022 \(L^B\)-valued general fuzzy automata. Zbl 1522.68258 Abolpour, Kh.; Zahedi, M. M. 1 2022 Prelinearity in (quasi-)Nelson logic. Zbl 1522.03078 Flaminio, Tommaso; Rivieccio, Umberto 1 2022 On ordinal sums of partially ordered monoids: a unified approach to ordinal sum constructions of t-norms, t-conorms and uninorms. Zbl 1522.06026 Dvořák, Antonín; Holčapek, Michal; Paseka, Jan 1 2022 Aggregation of indistinguishability operators. Zbl 1522.03239 Bejines, C.; Ardanza-Trevijano, S.; Chasco, M. J.; Elorza, J. 1 2022 An auxiliary system discretization approach to Takagi-Sugeno fuzzy models. Zbl 1522.93101 C. da S. Campos, Víctor; Braga, Márcio F.; Frezzatto, Luciano 1 2022 Label correlation in multi-label classification using local attribute reductions with fuzzy rough sets. Zbl 1522.68557 Che, Xiaoya; Chen, Degang; Mi, Jusheng 1 2022 Some multivariate imprecise shock model copulas. Zbl 1522.62029 Dolžan, David; Kokol Bukovšek, Damjana; Omladič, Matjaž; Škulj, Damjan 1 2022 Best-possible bounds on the set of copulas with a given value of Spearman’s footrule. Zbl 1522.62025 Beliakov, Gleb; de Amo, Enrique; Fernández-Sánchez, Juan; Úbeda-Flores, Manuel 1 2022 Correction to: “Best-possible bounds on the set of copulas with a given value of Spearman’s footrule”. Zbl 1522.62026 Beliakov, Gleb; de Amo, Enrique; Fernández-Sánchez, Juan; Úbeda-Flores, Manuel 1 2022 Fuzzy fractional differential equations with the generalized Atangana-Baleanu fractional derivative. Zbl 1522.34014 Vu, Ho; Ghanbari, Behzad; Van Hoa, Ngo 1 2022 Generalized fractional evolution equations driven by fuzzy variational inequalities. Zbl 1522.34018 Zeng, Shengda; Cen, Jinxia; Nguyen, Van Thien 1 2022 Fuzzy differential equations with Riemann-Liouville generalized fractional integrable impulses. Zbl 1522.34037 An, Truong Vinh; Hoa, Ngo Van 1 2022 Non-discrete \(k\)-order additivity of a set function and distorted measure. Zbl 1522.28026 Honda, Aoi; Fukuda, Ryoji; Okazaki, Yoshiaki 1 2022 Characterization of decomposition integrals extending Lebesgue integral. Zbl 1522.28029 Li, Jun; Mesiar, Radko; Ouyang, Yao; Šeliga, Adam 1 2022 Generalized pseudo-integral Jensen’s inequality for \(((\oplus_1,\otimes_1),(\oplus_2,\otimes_2))\)-pseudo-convex functions. Zbl 1522.28039 Zhang, Deli; Pap, Endre 1 2022 On some classes of nullnorms and \(h\)-pseudo homogeneity. Zbl 1522.03266 Lima, Lucélia; Bedregal, Benjamin; Rocha, Marcus; Castillo-Lopez, Aitor; Fernandez, Javier; Bustince, Humberto 1 2022 Construction methods for the smallest and largest uni-nullnorms on bounded lattices. Zbl 1522.03295 Wu, Xinxing; Liang, Shudi; Luo, Yang; Çaylı, Gül Deniz 1 2022 Characterizing idempotent nullnorms on a special class of bounded lattices. Zbl 1522.03294 Wu, Xinxing; Liang, Shudi; Çaylı, Gül Deniz 1 2022 lfl: an R package for linguistic fuzzy logic. Zbl 1522.03009 Burda, Michal; Štěpnička, Martin 1 2022 On the Sheffer stroke operation in fuzzy logic. Zbl 1522.03064 Baczyński, Michał; Berruezo, Pedro; Helbin, Piotr; Massanet, Sebastia; Niemyska, Wanda; Ruiz-Aguilera, Daniel 1 2022 Characterization of homogeneous and quasi-homogeneous binary aggregation functions. Zbl 1522.68583 Su, Yong; Zong, Wenwen; Mesiar, Radko 1 2022 Structure of uninorms not locally internal on the boundary. Zbl 1522.03296 Xie, Aifang 1 2022 Generalized Nash equilibrium problem over a fuzzy strategy set. Zbl 1522.91152 Wang, Xing; Teo, Kok Lay 1 2022 Comparison between the linearly correlated difference and the generalized Hukuhara difference of fuzzy numbers. Zbl 1522.26029 Shen, Yonghong 1 2022 A fuzzy methodology for approaching fuzzy sets of the real line by fuzzy numbers. Zbl 1522.03282 Roldán López de Hierro, Antonio Francisco; Tíscar, Miguel Ángel; Roldán, Concepción; Bustince, Humberto 1 2022 ...and 1489 more Documents all cited Publications top 5 cited Publications all top 5 Cited by 24,490 Authors 302 Mesiar, Radko 186 Yager, Ronald R. 167 De Baets, Bernard 163 Pedrycz, Witold 161 Dubois, Didier 144 Prade, Henri M. 140 Xu, Zeshui 119 Bustince Sola, Humberto 117 Allahviranloo, Tofigh 106 Davvaz, Bijan 96 Jun, Young Bae 93 Kerre, Etienne E. 85 Tong, Shaocheng 84 Hong, Dug Hun 82 Buckley, James J. 79 Lee, E. Stanley 76 Akram, Muhammad 75 Pap, Endre 75 Sakawa, Masatoshi 74 Maiti, Manoranjan 73 Zhan, Jianming 72 Shi, Fu-Gui 71 Park, Juhyun (Jessie) 71 Sakthivel, Rathinasamy 71 Torrens, Joan 71 Zhong, Shou-Ming 70 Li, Hongxing 69 Dvurečenskij, Anatolij 68 Hu, Baoqing 68 Wu, Congxin 67 Bedregal, Benjamín René Callejas 67 Grabisch, Michel 66 Cao, Jinde 65 Liu, Huawen 64 Chen, Shyiming 63 Herrera, Francisco 63 Medina, Jesús 62 Abbasbandy, Saeid 61 Ouyang, Yao 60 Fernández-Sánchez, Juan 59 Gil, María Angeles 59 Wu, Hsien-Chung 58 Beliakov, Gleb 58 Godo, Lluís 58 Montes, Susana 58 Novák, Vilém 58 Saadati, Reza 57 Durante, Fabrizio 57 Kolesárová, Anna 57 Perfilieva, Irina G. 56 Chalco-Cano, Yurilev 55 Mordeson, John N. 53 Shi, Kaibo 52 Fang, Jinxuan 52 Herrera-Viedma, Enrique 52 Klement, Erich Peter 52 Li, Qingguo 51 Li, Yongming 51 Shi, Peng 51 Tepavčević, Andreja 50 De Meyer, Hans E. 49 Román-Flores, Heriberto E. 47 Chen, Degang 47 Chen, Xiaohong 47 Park, Choonkil 47 Wang, Yingming 47 Xu, Shengyuan 46 Inuiguchi, Masahiro 46 Morsi, Nehad Nashaat 46 Verdegay, José Luis 46 Wang, Xueping 46 Zhang, Dexue 45 Agahi, Hamzeh 45 Cho, Yeol Je 45 Di Nola, Antonio 45 Kacprzyk, Janusz 45 Kar, Samarjit 45 Li, Jun 45 Montero, Javier 45 Šešelja, Branimir 45 Xu, Jiuping 45 Yang, Guanghong 44 D’Urso, Pierpaolo 44 Gong, Zengtai 44 Marichal, Jean-Luc 44 Úbeda-Flores, Manuel 44 Wang, Guojun 44 Yoshida, Yuji 43 Chen, Bing 43 Demirci, Mustafa 43 Yang, Miin-Shen 42 Fernández Fernández, Francisco Javier 42 Greco, Salvatore 42 Klir, George J. 42 Mahmood, Tahir 42 Pal, Madhumangal 42 Su, Yong 42 Xu, Yang 41 Borzooei, Rajab Ali 41 Cheng, Jun ...and 24,390 more Authors all top 5 Cited in 773 Journals 6,359 Fuzzy Sets and Systems 2,215 Information Sciences 1,019 Soft Computing 990 International Journal of Approximate Reasoning 724 European Journal of Operational Research 577 Journal of the Franklin Institute 474 International Journal of Uncertainty, Fuzziness and Knowledge-Based Systems 465 Applied Mathematics and Computation 428 Journal of Intelligent and Fuzzy Systems 362 Mathematical Problems in Engineering 356 Computers & Mathematics with Applications 325 International Journal of General Systems 309 International Journal of Systems Science. Principles and Applications of Systems and Integration 306 Applied Mathematical Modelling 297 Fuzzy Optimization and Decision Making 271 Computational and Applied Mathematics 260 Iranian Journal of Fuzzy Systems 229 Kybernetika 225 Chaos, Solitons and Fractals 206 Journal of Mathematical Analysis and Applications 197 International Journal of Intelligent Systems 193 Nonlinear Dynamics 188 International Journal of Robust and Nonlinear Control 180 Annals of Operations Research 156 International Journal of Systems Science 146 Advances in Difference Equations 145 Journal of Inequalities and Applications 142 Advances in Fuzzy Systems 138 Mathematical and Computer Modelling 137 Journal of Computational and Applied Mathematics 125 Abstract and Applied Analysis 122 Complexity 122 Journal of Applied Mathematics 119 Opsearch 119 Symmetry 114 Journal of Function Spaces 113 Computers & Operations Research 113 New Mathematics and Natural Computation 101 International Journal of Control 97 Automatica 97 Fuzzy Information and Engineering 94 Fixed Point Theory and Applications 91 Journal of Mathematics 89 Filomat 89 Discrete Dynamics in Nature and Society 88 Journal of Applied Mathematics and Computing 87 Nonlinear Analysis. Hybrid Systems 86 Afrika Matematika 83 Mathematics and Computers in Simulation 83 Pattern Recognition 81 Communications in Nonlinear Science and Numerical Simulation 78 International Journal of Production Research 77 Asian Journal of Control 75 AIMS Mathematics 74 Kybernetes 71 Circuits, Systems, and Signal Processing 70 International Journal of Theoretical Physics 69 Neural Networks 69 Linear Algebra and its Applications 67 Artificial Intelligence 67 International Journal of Computer Mathematics 66 International Journal of Adaptive Control and Signal Processing 63 Cybernetics and Systems 62 Applied Mathematics Letters 62 International Journal of Applied Mathematics and Computer Science 61 Mathematica Slovaca 60 Studia Logica 58 International Journal of Mathematics and Mathematical Sciences 57 Topology and its Applications 56 International Journal of Applied and Computational Mathematics 55 Korean Journal of Mathematics 52 International Transactions in Operational Research 51 Computer Methods in Applied Mechanics and Engineering 51 Nonlinear Analysis. Theory, Methods & Applications. Series A: Theory and Methods 51 Theoretical Computer Science 50 Journal of Multiple-Valued Logic and Soft Computing 47 Computational Statistics and Data Analysis 47 Archive for Mathematical Logic 46 Sahand Communications in Mathematical Analysis 45 Journal of Industrial and Management Optimization 45 Open Mathematics 43 Thai Journal of Mathematics 42 Journal of the Egyptian Mathematical Society 42 Journal of Discrete Mathematical Sciences & Cryptography 41 European Journal of Control 41 RAIRO. Operations Research 39 Mathematical Methods in the Applied Sciences 37 Journal of Optimization Theory and Applications 37 Quaestiones Mathematicae 37 Mathematical Biosciences and Engineering 36 Physica A 36 Mathematical Social Sciences 36 South East Asian Journal of Mathematics and Mathematical Sciences 36 Journal of Nonlinear Science and Applications 35 Optimal Control Applications & Methods 35 Optimization 35 Asia-Pacific Journal of Operational Research 35 Annals of Mathematics and Artificial Intelligence 35 CEJOR. Central European Journal of Operations Research 33 Journal of Systems Science and Complexity ...and 673 more Journals all top 5 Cited in 62 Fields 6,024 Mathematical logic and foundations (03-XX) 5,002 Computer science (68-XX) 4,726 Operations research, mathematical programming (90-XX) 4,656 Systems theory; control (93-XX) 3,458 Game theory, economics, finance, and other social and behavioral sciences (91-XX) 2,353 General topology (54-XX) 1,977 Statistics (62-XX) 1,752 Order, lattices, ordered algebraic structures (06-XX) 1,224 Measure and integration (28-XX) 1,155 Ordinary differential equations (34-XX) 1,136 Real functions (26-XX) 1,105 Probability theory and stochastic processes (60-XX) 971 Information and communication theory, circuits (94-XX) 851 Numerical analysis (65-XX) 712 Biology and other natural sciences (92-XX) 577 Group theory and generalizations (20-XX) 546 Functional analysis (46-XX) 508 Linear and multilinear algebra; matrix theory (15-XX) 499 Operator theory (47-XX) 379 Difference and functional equations (39-XX) 366 Category theory; homological algebra (18-XX) 344 Combinatorics (05-XX) 312 General algebraic systems (08-XX) 311 Associative rings and algebras (16-XX) 264 Calculus of variations and optimal control; optimization (49-XX) 236 Dynamical systems and ergodic theory (37-XX) 198 Sequences, series, summability (40-XX) 189 Quantum theory (81-XX) 183 Integral equations (45-XX) 166 Partial differential equations (35-XX) 128 Mechanics of deformable solids (74-XX) 123 Approximations and expansions (41-XX) 113 Mechanics of particles and systems (70-XX) 79 Convex and discrete geometry (52-XX) 70 Commutative algebra (13-XX) 65 Integral transforms, operational calculus (44-XX) 55 General and overarching topics; collections (00-XX) 53 Topological groups, Lie groups (22-XX) 43 History and biography (01-XX) 42 Statistical mechanics, structure of matter (82-XX) 38 Geophysics (86-XX) 33 Number theory (11-XX) 32 Fluid mechanics (76-XX) 31 Field theory and polynomials (12-XX) 23 Algebraic topology (55-XX) 21 Geometry (51-XX) 19 Special functions (33-XX) 19 Harmonic analysis on Euclidean spaces (42-XX) 18 Functions of a complex variable (30-XX) 14 Algebraic geometry (14-XX) 14 Nonassociative rings and algebras (17-XX) 13 Global analysis, analysis on manifolds (58-XX) 12 Manifolds and cell complexes (57-XX) 11 Classical thermodynamics, heat transfer (80-XX) 8 Differential geometry (53-XX) 7 Optics, electromagnetic theory (78-XX) 6 Relativity and gravitational theory (83-XX) 4 Abstract harmonic analysis (43-XX) 3 Potential theory (31-XX) 3 Several complex variables and analytic spaces (32-XX) 2 Mathematics education (97-XX) 1 \(K\)-theory (19-XX) Citations by Year