• 논리연구
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• 제21권1호
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• pp.59-96
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• 2018

순수하게 형식적인 견지에서 직관주의 논리는 거짓말쟁이 유형의 역설을 다루는데 어떠한 이점도 없다고 여겨진다. 이 글에서 우리는 표준 직관주의 자연연역체계가 거짓말쟁이 유형의 역설에 취약함을 논할 것이다. 다시 말해, 거짓말쟁이 유형의 문장을 수용함이 모순(${\perp}$)을 도출하는 추론을 야기한다는 것이다. 이러한 결과는 이중부정 제거규칙(DNE)에 대한 제약이 ${\perp}$을 도출하는 추론을 막지 못한다는 것을 보여준다. 하지만 이는 거짓말쟁이 유형의 역설에 대한 직관주의적 접근법이 잘못된 것이 아니라 표준 자연연역 체계의 표현력이 부족한 문제라고 할 수 있다. 우리는 주어진 체계 S에 대한 메타-레벨 부정 연산자 ⊬$_s$와 메타-레벨 모순 연산자 ⋏를 직관주의 체계에 도입할 것이다. 그리고 체계의 완전성에 대한 가정 없이는 이 체계에서 ${\perp}$에 대한 추론을 얻을 수 없음을 보일 것이다. 또한 우리는 이중 메타-레벨 부정 제거규칙(DMNE)을 고려할 것이다. 이 규칙은 체계의 완전성을 암묵적으로 가정하며 DMNE에 대한 제약은 ${\perp}$의 추론을 막을 수 있을 것이다.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제9권2호
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• pp.137-140
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• 2009

In this paper, we introduce and formulate the definitions of Banach operator type k and Banach operator pair on intuitionistic fuzzy metric space. Thereafter we prove some properties and theorems on intuitionistic fuzzy metric space.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제11권3호
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• pp.184-189
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• 2011

Generalized intuitionistic fuzzy soft set theory, proposed by Park et al. [Journal of Korean Institute of Intelligent Systems 21(3) (2011) 389-394], has been regarded as an effective mathematical tool to deal with uncertainties. In this paper, we prove that certain De Margan's law hold in generalized intuitionistic fuzzy soft set theory with respect to union and intersection operations on generalized intuitionistic fuzzy soft sets. We discuss the basic properties of operations on generalized intuitionistic fuzzy soft sets such as necessity and possibility. Moreover, we illustrate their interconnections between each other.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제11권1호
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• pp.8-11
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• 2011

Atanassov [1,2] and Szmidt and Kacprzyk[7,8] studied various methods for measuring distances between intuitionistic fuzzy sets. In this paper, we consider interval-valued intuitionistic fuzzy sets and discuss these methods for measuring distances between interval-valued intuitionistic fuzzy sets.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제10권2호
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• pp.152-156
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• 2010

We define some terminologies on intuitionistic fuzzy metric space and prove that the topology generated by any intuitionistic fuzzy metric space is metrizable. Also, we show that if the intuitionistic fuzzy metric space is complete, then the generated topology is completely metrizable, a Baire space, and that an intuitionistic fuzzy metric space is precompact if and only if every sequence has a Cauchy subsequence.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제9권2호
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• pp.110-114
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• 2009

We introduce the concepts of intuitionistic fuzzy k-ideals and intuitionistic fuzzy prime k-ideals of a semiring. And we investigate some properties of them.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제13권3호
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• pp.224-230
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• 2013

In this paper, we introduce certain types of continuous functions and intuitionistic fuzzy ${\theta}$-compactness in intuitionistic fuzzy topological spaces. We show that intuitionistic fuzzy ${\theta}$-compactness is strictly weaker than intuitionistic fuzzy compactness. Furthermore, we show that if a topological space is intuitionistic fuzzy retopologized, then intuitionistic fuzzy compactness in the new intuitionistic fuzzy topology is equivalent to intuitionistic fuzzy ${\theta}$-compactness in the original intuitionistic fuzzy topology. This characterization shows that intuitionistic fuzzy ${\theta}$-compactness can be related to an appropriated notion of intuitionistic fuzzy convergence.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제6권1호
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• pp.85-93
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• 2006

We study the conditions under which a given intuitionistic fuzzy subgroup of a given group can or can not be realized as a union of two proper intuitionistic fuzzy subgroups. Moreover, we provide a simple necessary and sufficient condition for the union of an arbitrary family of intuitionistic fuzzy subgroups to be an intuitionistic fuzzy subgroup. Also we formulate the concept of intuitionistic fuzzy subgroup generated by a given intuitionistic fuzzy set by level subgroups. Furthermore we give characterizations of intuitionistic fuzzy conjugate subgroups and intuitionistic fuzzy characteristic subgroups by their level subgroups. Also we investigate the level subgroups of the homomorphic image of a given intuitionistic fuzzy subgroup.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제9권1호
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• pp.53-58
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• 2009

We unite the two con concepts - normality We unite the two con concepts - normality and congruence - in an intuitionistic fuzzy subgroup setting. In particular, we prove that every intuitionistic fuzzy congruence determines an intuitionistic fuzzy subgroup. Conversely, given an intuitionistic fuzzy normal subgroup, we can associate an intuitionistic fuzzy congruence. The association between intuitionistic fuzzy normal sbgroups and intuitionistic fuzzy congruences is bijective and unigue. This leads to a new concept of cosets and a corresponding concept of guotient.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제15권2호
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• pp.137-144
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• 2015

In this paper, we obtain two types of adjoint functors between the category of intuitionistic fuzzy topological spaces in Mondal and Samanta’s sense, and the category of intuitionistic fuzzy topological spaces in Ŝostak’s sense. Also, we reveal that the category of Chang’s fuzzy topological spaces is a bireflective full subcategory of the category of intuitionistic fuzzy topological spaces in Mondal and Samanta’s sense.