• 대한수학회지
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• 제54권1호
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• pp.101-115
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• 2017

In this paper, we study three types of lightlike hypersurfaces, which are called recurrent, Lie recurrent and Hopf lightlike hypersurfaces, of an indefinite Kaehler manifold with a semi-symmetric non-metric connection. We provide several new results on such three types of lightlike hypersurfaces of an indefinite Kaehler manifold or an indefinite complex space form, with a semi-symmetric non-metric connection.

• 대한수학회논문집
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• 제35권2호
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• pp.603-611
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• 2020

The purpose of this note is to introduce a type of Riemannian manifold called an almost quasi Ricci symmetric manifold and investigate the several properties of such a manifold on which some geometric conditions are imposed. And the existence of such a manifold is ensured by a proper example.

• 대한수학회지
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• 제48권1호
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• pp.13-21
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• 2011

In this paper, a pair of Wolfe type nondifferentiable sec-ond order symmetric minimax mixed integer dual problems is formu-lated. Symmetric and self-duality theorems are established under $\eta_1$-bonvexity/$\eta_2$-boncavity assumptions. Several known results are obtained as special cases. Examples of such primal and dual problems are also given.

• Kyungpook Mathematical Journal
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• 제51권3호
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• pp.261-281
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• 2011

In this paper, we will construct symmetric links by using the method adapted from the graph theory, and study a Seifert matrix of a symmetric link from the information of the Seifert matrix of the base link and the corresponding group action.

• East Asian mathematical journal
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• 제36권1호
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• pp.1-11
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• 2020

In this paper, we introduce the notion of symmetric bi-f-derivation of lattice implication algebra and investigated some related properties. Also, we prove that if D is a symmetric bi-f-derivation of L, then D(x → y, z) = f(x) → D(y, z) for all x, y, z ∈ L.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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• pp.1113-1116
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• 2001

Recently, the needs of non-symmetric spherical lens are increasing. Machining non-symmetric spherical lens by general method is limited. This paper researches grinding machine method for non-symmetric spherical lens and accruable problems at processing lens using CAD/CAM. In addition, this paper researches the relation of curvatures to grinding wheel sizes.

• Journal of the Korean Data and Information Science Society
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• 제18권2호
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• pp.543-552
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• 2007

We consider estimation of the right-tail probability in a half-triangle distribution, and also consider inference on reliability, and derive the k-th moment of ratio of two independent half-triangle distributions with different supports. As we define a skew-symmetric random variable from a symmetric triangle distribution about origin, we derive its k-th moment.

• East Asian mathematical journal
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• 제29권3호
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• pp.255-258
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• 2013

In this paper, we initiate the study of zero symmetric and constant parts of near-rings, and then apply these to self map near-rings. Next, we investigate that every near-ring can be embedded into some self map near-ring, and every zero symmetric near-ring can be embedded into some zero symmetric self map near-ring.

• 조명전기설비학회논문지
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• 제23권11호
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• pp.94-101
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• 2009

This paper poses tracking control and torque control methods to reduce torque ripple for bilateral symmetric trainers. As opposed to the conventional method, the torque control method for active joint movement is proposed. Using a step motor (PK296-03b, step angle: $1.8^{\circ}$), a simulator for a bilateral symmetric trainer is created, and the effectiveness of the proposed control method is verified through experiment results.

• Journal of applied mathematics & informatics
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• 제29권1_2호
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• pp.523-527
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• 2011

In this paper, We initiate a study of zero symmetric and constant parts of near-rings, and then apply these to self map near-rings. Next, we investigate that every near-ring can be embedded into some self map near-ring, and every zero symmetric near-ring can be embedded into some zero symmetric self map near-ring.