• East Asian mathematical journal
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• 제26권3호
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• pp.379-387
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• 2010

In this paper, we prove that the extension ideal of a fuzzy characteristic ideal of a positive implicative BCK-algebra is a fuzzy characteristic ideal. We introduce the notion of the extension of intuitionistic fuzzy ideal of BCK-algebras and some properties of fuzzy intuitionistic ideal extensions of BCK-algebra are investigated.

• East Asian mathematical journal
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• 제15권1호
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• pp.11-17
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• 1999

• 대한수학회보
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• 제39권2호
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• pp.185-198
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• 2002

We Consider the fuzzification of sub-implicative ideals in BCI-algebras, and investigate some related properties. We give conditions for a fuzzy ideal to be a fuzzy sub-implicative ideal. we show that (1) every fuzzy sub-implicative ideal is a fuzzy ideal, but the converse is not true, (2) every fuzzy sub-implicative ideal is a fuzzy positive implicative ideal, but the converse is not true, and (3) every fuzzy p-ideal is a fuzzy sub-implicative ideal, but the converse is not true. Using a family of sub-implicative ideals of a BCI-algebra, we establish a fuzzy sub-implicative ideal, and using a level set of a fuzzy set in a BCI-algebra, we give a characterization of a fuzzy sub-implicative ideal.

• Korean Journal of Mathematics
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• 제28권1호
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• pp.31-47
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• 2020

In this paper, we discuss in detail some of the properties of the new kind of (∈, ∈ ∨q)-fuzzy ideals in Near-ring. The concept of (∈, ∈ ∨q^δ₀)-fuzzy ideal of Near-ring is introduced and some of its related properties are investigated.

• 대한수학회논문집
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• 제30권3호
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• pp.143-154
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• 2015

Characterizations of hesitant fuzzy left (right) ideals are considered. The notion of hesitant fuzzy (generalized) bi-ideals is introduced, and related properties are investigated. Relations between hesitant fuzzy generalized bi-ideals and hesitant fuzzy semigroups are discussed, and characterizations of (hesitant fuzzy) generalized bi-ideals and hesitant fuzzy bi-ideals are considered. Given a hesitant fuzzy set $\mathcal{H}$ on a semigroup S, hesitant fuzzy (generalized) bi-ideals generated by $\mathcal{H}$ are established.

• Korean Journal of Mathematics
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• 제8권2호
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• pp.147-154
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• 2000

In this paper, with the notion of fuzzy ${\kappa}$-ideals of semirings, we discuss and review several results described in [4].

• 한국사회정책
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• 제20권3호
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• pp.47-76
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• 2013

1990년 후반부터 사회정책 및 복지국가 연구에서 활발하게 논의되기 시작한 '신사회위험' 연구는 일반적으로 탈산업화 또는 세계화의 영향으로 새로운 사회적 위험이 후기산업경제에 도래했다고 주장한다. 이러한 신사회적 위험은 또한 주로 청년층, 여성 그리고 저숙련자에게 집중되었다고 논의되고 있다. 본 연구에서는 먼저 신사회적위험의 개념화작업을 통해 논의를 재검토하고 다른 유형의 사회적 위험들의 변화 양상을 실증적으로 분석하는데 특히 노동시장의 위험에 초점을 맞춘다. 이를 위해 후기산업경제 18개국을 대상으로, 퍼지셋 이상형분석을 실시하여 국가별로 노동시장 위험이 어떻게 서로 다르게 또는 비슷하게 변화하는지 비교분석한다. 구체적으로 본 논문의 연구문제는 다음과 같다; 1) 신사회적 위험은 무엇인가? 그리고 2) 각 국가에서 서로 다른 유형의 노동시장위험이 어떻게 서로 다른 속도와 정도의 차이를 보이며 변화하는가? 본 논문의 분석결과 후기산업경제의 국가들은 다양한 노동시장에서의 사회적 위험 유형을 경험하고 있으며, 그 유형의 변화 속도 및 정도의 차이 또한 다양하여 일반적으로 공통된 위험을 주장한 '신사회적위험'의 논의와 차이를 보였다. 본 연구는 퍼지셋 이상형분석을 활용한 실증적 비교연구를 실시하여 신사회위험 및 노동시장위험 논의에 기여한다.

• 산업경영시스템학회지
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• 제46권4호
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• pp.199-208
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• 2023

Taguchi method is one of the most popular approaches for design optimization such that performance characteristics become robust to uncontrollable noise variables. However, most previous Taguchi method applications have addressed a single-characteristic problem. Problems with multiple characteristics are more common in practice. The multi-criteria decision making(MCDM) problem is to select the optimal one among multiple alternatives by integrating a number of criteria that may conflict with each other. Representative MCDM methods include TOPSIS(Technique for Order of Preference by Similarity to Ideal Solution), GRA(Grey Relational Analysis), PCA(Principal Component Analysis), fuzzy logic system, and so on. Therefore, numerous approaches have been conducted to deal with the multi-characteristic design problem by combining original Taguchi method and MCDM methods. In the MCDM problem, multiple criteria generally have different measurement units, which means that there may be a large difference in the physical value of the criteria and ultimately makes it difficult to integrate the measurements for the criteria. Therefore, the normalization technique is usually utilized to convert different units of criteria into one identical unit. There are four normalization techniques commonly used in MCDM problems, including vector normalization, linear scale transformation(max-min, max, or sum). However, the normalization techniques have several shortcomings and do not adequately incorporate the practical matters. For example, if certain alternative has maximum value of data for certain criterion, this alternative is considered as the solution in original process. However, if the maximum value of data does not satisfy the required degree of fulfillment of designer or customer, the alternative may not be considered as the solution. To solve this problem, this paper employs the desirability function that has been proposed in our previous research. The desirability function uses upper limit and lower limit in normalization process. The threshold points for establishing upper or lower limits let us know what degree of fulfillment of designer or customer is. This paper proposes a new design optimization technique for multi-characteristic design problem by integrating the Taguchi method and our desirability functions. Finally, the proposed technique is able to obtain the optimal solution that is robust to multi-characteristic performances.