Your search for: 'author:("Park, Choonkil")' has returned 18 results. (0.035s) Save search

Authors: Shokri, Javad | Park, Choonkil

Article Type: Research Article

Abstract:  We establish some stability results concerning the 2-dimensional vector variable quadratic functional equation f ( x + y , z + w ) + f ( x - y , z - w ) = 2 f ( x , z ) + 2 f ( y , w ) in non-Archimedean L * -fuzzy normed spaces.

Keywords: ℒ*-fuzzy metric and normed space, Hyers-Ulam stability, quadratic functional equation, non-Archimedean ℒ*-fuzzy normed space

DOI: 10.3233/JIFS-190802

Citation: Journal of Intelligent & Fuzzy Systems, vol. 38, no. 4, pp. 4265-4272, 2020

Authors: Zhang, Xiaohong | Park, Choonkil | Wu, Supeng

Article Type: Research Article

Abstract: The notion of pseudo-BCI algebra is introduced by W.A. Dudek and Y.B. Jun, it is a kind of non-classical logic algebra and a generalization of pseudo-BCK algebra which is close connection with various non-commutative fuzzy logic algebras. The concept of soft set is introduced by Molodtsov, it can be seen as a new mathematical tool for dealing with uncertainty. In this paper, soft set theory is applied to pseudo-BCI algebras, the new notions of soft pseudo-BCI algebras and filteristic soft pseudo-BCI algebras are introduced. The relationships between soft pseudo-BCI algebras and soft non-commutative residuated lattices are presented. The union, intersection, …int-product, uni-product and difference operations of (filteristic) soft pseudo-BCI algebras are investigated. Finally, another application of soft set to pseudo-BCI algebras is discussed, the new concept of int-soft filters in pseudo-BCI algebras is introduced, and related properties are proved. Show more

Keywords: Fuzzy logic, soft set, soft pseudo-BCI algebra, filteristic soft pseudo-BCI algebra, int-soft filter

DOI: 10.3233/JIFS-17777

Citation: Journal of Intelligent & Fuzzy Systems, vol. 34, no. 1, pp. 559-568, 2018

Authors: Park, Choonkil | Rehman, Noor | Ali, Abbas

Article Type: Research Article

Abstract: The q -rung orthopair fuzzy sets accommodate more uncertainties than the Pythagorean fuzzy sets and hence their applications are much extensive. Under the q -rung orthopair fuzzy set, the objective of this paper is to develop new types of q -rung orthopair fuzzy lower and upper approximations by applying the tolerance degree on the similarity between two objects. After employing tolerance degree based q -rung orthopair fuzzy rough set approach to it any times, we can get only the six different sets at most. That is to say, every rough set in a universe can be approximated by only six …sets, where the lower and upper approximations of each set in the six sets are still lying among these six sets. The relationships among these six sets are established. Furthermore, we propose tolerance degree based multi granulation optimistic/pessimistic q -rung orthopair fuzzy rough sets and investigate some of their properties. Another main contribution of this paper is to disclose the ideas of different kinds of approximations called approximate precision, rough degree, approximate quality and their mutual relationship. Finally a technique is devloped to rank the alternatives in a q -rung orthopair fuzzy information system based on similarity relation. We find that the proposed method/technique is more efficient when compared with other existing techniques. Show more

Keywords: q-rung orthopair fuzzy set, fuzzy rough set, similarity relation, tolerance classes, multigranulation q-rung orthopair fuzzy rough sets

DOI: 10.3233/JIFS-221249

Citation: Journal of Intelligent & Fuzzy Systems, vol. 44, no. 3, pp. 4301-4321, 2023

Authors: Jain, Manish | Kumar, Sanjay | Park, Choonkil

Article Type: Research Article

Abstract: The question of relaxing the compatible hypothesis of the pair of mappings in fixed point theory has always been remained an open problem. We address such an open problem raised by Choudhury et al. [4 ] and also explicitly settles the issue of monotone and continuity hypotheses of the involved mappings in coupled coincidence point results. Moreover, we state a gap in an example given in [3 ] and repair it. Application to the dynamic programming problem shows the usability of present work. Finally, we also propose an open problem for further investigation.

Keywords: GV-fuzzy metric space,φ-contractions, Hadɘić type t-norm, mixed monotone property, coupled coincidence point 2010 Mathematics Subject Classification. 47H10, 54H25.

DOI: 10.3233/JIFS-222637

Citation: Journal of Intelligent & Fuzzy Systems, vol. 44, no. 5, pp. 7211-7223, 2023

Authors: Bo, Chunxin | Zhang, Xiaohong | Shao, Songtao | Park, Choonkil

Article Type: Research Article

Abstract: The notion of hesitant fuzzy set is introduced by V. Torra, which is a very useful tool to express peoples’ hesitancy in daily life. The notion of pseudo-BCI algebra is introduced by W. A. Dudek and Y. B. Jun, which is a kind of nonclassical logic algebra and close connection with various non-commutative fuzzy logic algebras. In this paper, hesitant fuzzy theory is applied to pseudo-BCI algebras. The new concepts of hesitant fuzzy filter and anti-grouped hesitant fuzzy filter in pseudo-BCI algebras are proposed, and their characterizations are presented. Also, the relationships between fuzzy filters and hesitant fuzzy filters are …discussed. Moreover, by introducing the notion of tip-extended pair of hesitant fuzzy filters, a new union operation (generated by the union of two hesitant fuzzy filters) is defined and it is proved that the set of all hesitant fuzzy filters in pseudo-BCI algebras forms a bounded distributive lattice about intersection and the new union. Show more

Keywords: Hesitant fuzzy set, pseudo-BCI algebra, hesitant fuzzy filter, anti-grouped hesitant fuzzy filter, lattice

DOI: 10.3233/JIFS-172024

Citation: Journal of Intelligent & Fuzzy Systems, vol. 35, no. 3, pp. 3333-3345, 2018

Authors: Shao, Songtao | Zhang, Xiaohong | Bo, Chunxin | Park, Choonkil

Article Type: Research Article

Abstract: This paper introduced the notions of rough filters, multi-granulation rough filters, and rough fuzzy filters in pseudo-BCI algebras and investigated some properties. First, a congruence relation was structured by a filter on pseudo-BCI algebra. Then rough filters and rough fuzzy filters were investigated. Next, the relationships between upper (lower) rough filters and upper (lower) approximations of their fuzzy homomorphic images were discussed. Furthermore, original rough filter model was extended to a multi-granulation rough filter model, where the set approximations were defined by using multi congruence relations on pseudo-BCI algebra.

Keywords: Pseudo-BCI algebra, rough set, fuzzy set, multi-granulation rough set

DOI: 10.3233/JIFS-18144

Citation: Journal of Intelligent & Fuzzy Systems, vol. 34, no. 6, pp. 4377-4386, 2018

Authors: Zhang, Xiaohong | Wu, Xiaoying | Mao, Xiaoyan | Smarandache, Florentin | Park, Choonkil

Article Type: Research Article

Abstract: From the perspective of semigroup theory, the characterizations of a neutrosophic extended triplet group (NETG) and AG-NET-loop (which is both an Abel-Grassmann groupoid and a neutrosophic extended triplet loop) are systematically analyzed and some important results are obtained. In particular, the following conclusions are strictly proved: (1) an algebraic system is neutrosophic extended triplet group if and only if it is a completely regular semigroup; (2) an algebraic system is weak commutative neutrosophic extended triplet group if and only if it is a Clifford semigroup; (3) for any element in an AG-NET-loop, its neutral element is unique and idempotent; (4) …every AG-NET-loop is a completely regular and fully regular Abel-Grassmann groupoid (AG-groupoid), but the inverse is not true. Moreover, the constructing methods of NETGs (completely regular semigroups) are investigated, and the lists of some finite NETGs and AG-NET-loops are given. Show more

Keywords: Semigroup, neutrosophic extended triplet group (NETG), completely regular semigroup, Clifford semigroup, Abel-Grassmann’s groupoid (AG-groupoid)

DOI: 10.3233/JIFS-181742

Citation: Journal of Intelligent & Fuzzy Systems, vol. 37, no. 4, pp. 5743-5753, 2019

Authors: Hadi, Sarem H. | Madhi, Zainab S. | Park, Choonkil

Article Type: Research Article

Abstract: The purpose of this study is to introduce a new concept of the modular space, which is C Ω -modular space, and then some of the convex properties are discussed. We also study finding fixed-point in C Ω -modular space.

Keywords: CΩ-modular space, 𝒢-convergence, 𝒢-Cauchy sequence, fixed-point in CΩ-modular space

DOI: 10.3233/JIFS-202698

Citation: Journal of Intelligent & Fuzzy Systems, vol. 40, no. 6, pp. 11475-11478, 2021

Authors: Saleem, Naeem | Işık, Hüseyin | Furqan, Salman | Park, Choonkil

Article Type: Research Article

Abstract: In this paper, we introduce the concept of fuzzy double controlled metric space that can be regarded as the generalization of fuzzy b -metric space, extended fuzzy b -metric space and controlled fuzzy metric space. We use two non-comparable functions α and β in the triangular inequality as: M q ( x , z , t α ( x , y ) + s β ( y , z ) ) ≥ M q ( x , y , t ) ∗ M q ( y , z , s ) . We prove Banach contraction principle in fuzzy double …controlled metric space and generalize the Banach contraction principle in aforementioned spaces. We give some examples to support our main results. An application to existence and uniqueness of solution for an integral equation is also presented in this work. Show more

Keywords: Extended fuzzy b-metric space, controlled fuzzy metric space, fixed point

DOI: 10.3233/JIFS-202594

Citation: Journal of Intelligent & Fuzzy Systems, vol. 40, no. 5, pp. 9977-9985, 2021

Authors: Ali, Abbas | Rehman, Noor | Jang, Sun Young | Park, Choonkil

Article Type: Research Article

Abstract:  The notions of fuzzy upward β -covering, the fuzzy upward β -neighborhood, upward β -neighborhood and fuzzy complement β -neighborhood are introduced and several related properties are studied. Furthermore, multigranulation optimistic/pessimistic fuzzy rough sets based on fuzzy upward β -covering are initiated and their fundamental properties are investigated. We also find the upward β -neighborhood in the fuzzy upward covering approximation space and present the optimistic/pessimistic multigranulation rough sets to further enrich the presented notions. The medicine selection via fuzzy upward β -covering rough sets in medical diagnosis is another main contribution of the present work. It is also explored …that which medicine can be prescribed for which particular symtom(s) and which disease. Show more

Keywords: Fuzzy preference relation, fuzzy rough set, β-covering rough sets

DOI: 10.3233/JIFS-190447

Citation: Journal of Intelligent & Fuzzy Systems, vol. 37, no. 3, pp. 4369-4390, 2019