• 한국운동역학회지
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• 제15권3호
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• pp.61-70
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• 2005

The purpose of study was to investigate the kinematic variables of Kenmotsu motion in Parallel bars. To this study, by 3 dimensional kinematical analysis of 4 male national gymnasts participants in the 28th Athens Olympic Game in 2004, kinematic data collected using video camera. Coordinate data were smoothed by using a fourth-order Butterworth low pass digital filter with cutoff frequency of 6Hz. The conclusions were as follows. 1. In P2, because the constrained swing movement made the movement of a rising back difficult7, the movements of Reg. were performed at low position after Air phase. 2. In E5 event, for the shake of a stable handstand and applied techniques like a Belle(E-value), a Belle Piked(super E-value), a vertical velocity in E2, a horizontal velocity in E3 and a vertical velocity in E4 were necessary for high velocities. 3. In E4 event, it was appeared that for a flexible body's movement of a vertical up-flight, the large angle of the shoulder joint and the flexion & extension of the hip joint were necessary in Air phase and a long flight time and vertical displacement made Reg. movements stable at the high position.

• 한국산업정보학회논문지
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• 제7권3호
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• pp.89-94
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• 2002

본 논문은 주로 개 f-코심플렉틱 다양체를 다룬다. 이 개념은 개 코심플렉틱 다양체와 개 겐모츠 다양체를 포함한다. 개 코심플렉틱 다양체는 ［1］에서 도입된 이래 ［2］, ［3］, ［4］ 등 여러 학자들에 의해 연구되어져 왔으며 개 겐모츠 다양체는 ［5］에서 도입된 이래 ［6］, ［7］ 등에서 연구되어져 왔다. 본 논문에서는 개f-코심플렉틱 다양체의 접촉 초함수에 의해 정의되는 정규 엽층구조의 기하학적 성질을 연구한다. 본 논문의 목적은 ［8］, ［9］에서 얻은 성과를 확장하는 것이다.

• 대한수학회논문집
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• 제35권2호
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• pp.625-637
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• 2020

The object of the present paper is to characterize 3-dimensional trans-Sasakian manifolds of type (α, β) admitting ∗-Ricci solitons and ∗-gradient Ricci solitons. Under certain restrictions on the smooth functions α and β, we have proved that a trans-Sasakian 3-manifold of type (α, β) admitting a ∗-Ricci soliton reduces to a β-Kenmotsu manifold and admitting a ∗-gradient Ricci soliton is either flat or ∗-Einstein or it becomes a β-Kenmotsu manifold. Also an illustrative example is presented to verify our results.

• 호남수학학술지
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• 제38권1호
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• pp.59-69
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• 2016

We classify conformally flat Kenmotsu 3-manifolds and classify conformally flat cosympletic 3-manifolds.

• 대한수학회논문집
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• 제19권1호
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• pp.129-134
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• 2004

It is well known that the warped product $L\;{\times}\;{_f}\;F$ of a line L and a Kaehler manifold F is an almost contact Riemannian manifold which is characterized by some tensor equations appeared in (1.7) and (1.8). In this paper we determine contact slant submanifolds tangent to the structure vector field of $L\;{\times}\;{_f}\;F$.

• Journal of applied mathematics & informatics
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• 제9권1호
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• pp.441-447
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• 2002

We show that the conharmonical1y flat K-contact find cosymplectic manifolds are local1y Euclidean. Evidently non locally Euclidean conharmonically flat Sasakian manifold does not exist. Moreover we see that conharmonically flat Kenmotsu manifold does not exist and conharmonically flat fibred quasi quasi Sasakian space is locally Euclidean if and only if the scalar curvature of each fibre vanishes identically.

• Kyungpook Mathematical Journal
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• 제61권3호
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• pp.645-660
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• 2021

This paper examines the behavior of a 3-dimensional trans-Sasakian manifold equipped with a gradient generalized quasi-Yamabe soliton. In particular, It is shown that α-Sasakian, β-Kenmotsu and cosymplectic manifolds satisfy the gradient generalized quasi-Yamabe soliton equation. Furthermore, in the particular case when the potential vector field ζ of the quasi-Yamabe soliton is of gradient type ζ = grad(ψ), we derive a Poisson's equation from the quasi-Yamabe soliton equation. Also, we study harmonic aspects of quasi-Yamabe solitons on 3-dimensional trans-Sasakian manifolds sharing a harmonic potential function ψ. Finally, we observe that 3-dimensional compact trans-Sasakian manifold admits the gradient generalized almost quasi-Yamabe soliton with Hodge-de Rham potential ψ. This research ends with few examples of quasi-Yamabe solitons on 3-dimensional trans-Sasakian manifolds.