• 천문학논총
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• 제30권2호
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• pp.271-273
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• 2015

The bulk motion of star clusters can be determined after careful membership analysis using parametric or non-parametric approaches. This study aims to implement non-parametric membership analysis based on Binned Kernel Density Estimators which takes into account measurements errors (simply called BKDE-e) to determine the average proper motion of each cluster. This method is applied to 178 selected star clusters with angular diameters less than 20 arcminutes. Proper motion data from UCAC4 are used for membership determination. Non-parametric analysis using BKDE-e successfully determined the average proper motion of 129 clusters, with good accuracy. Compared to COCD and NCOVOCC, there are 79 clusters with less than $3{\sigma}$ difference. Moreover, we are able to analyse the distribution of the member stars in vector point diagrams which is not always a normal distribution.

• Kyungpook Mathematical Journal
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• 제50권4호
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• pp.509-536
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• 2010

In this paper, we investigate curvature-adapted and proper complex equifocal submanifolds in a symmetric space of non-compact type. The class of these submanifolds contains principal orbits of Hermann type actions as homogeneous examples and is included by that of curvature-adapted and isoparametric submanifolds with flat section. First we introduce the notion of a focal point of non-Euclidean type on the ideal boundary for a submanifold in a Hadamard manifold and give the equivalent condition for a curvature-adapted and complex equifocal submanifold to be proper complex equifocal in terms of this notion. Next we show that the complex Coxeter group associated with a curvature-adapted and proper complex equifocal submanifold is the same type group as one associated with a principal orbit of a Hermann type action and evaluate from above the number of distinct principal curvatures of the submanifold.

• 대한수학회지
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• 제50권3호
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• pp.579-589
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• 2013

A finite group G is called an NSN-group if every proper subgroup of G is either normal in G or self-normalizing. In this paper, the non-NSN-groups whose proper subgroups are all NSN-groups are determined.

• 대한수학회논문집
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• 제32권3호
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• pp.745-763
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• 2017

The Borel-Serre partial compactification gives cofinite models for the proper classifying space for arithmetic lattices. Non-arithmetic lattices arise only in semisimple Lie groups of ${\mathbb{R}}$-rank one. The author generalizes the Borel-Serre partial compactification to construct cofinite models for the proper classifying space for lattices in semisimple Lie groups of ${\mathbb{R}}$-rank one by using the reduction theory of Garland and Raghunathan.

• 대한수학회보
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• 제36권2호
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• pp.315-336
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• 1999

In the paper [12] we have introduced the new kind of pseudo-einstein ruled real hypersurfaces in complex space forms $M_n(c), c\neq0$, which are foliated by pseudo-Einstein leaves. The purpose of this paper is to give a geometric condition for non-proper pseudo-Einstein ruled real hypersurfaces to be totally geodesic in the sense of Kimura [8] for c> and Ahn, Lee and the present author [1] for c<0.

• 대한수학회논문집
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• 제37권3호
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• pp.865-879
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• 2022

Let (M^m, g) be an m-dimensional Riemannian manifold. In this paper, we introduce a new class of metric on (M^m, g), obtained by a non-conformal deformation of the metric g. First we investigate the Levi-Civita connection of this metric. Secondly we characterize the Riemannian curvature, the sectional curvature and the scalar curvature. In the last section we characterizes some class of proper biharmonic maps. Examples of proper biharmonic maps are constructed when (M^m, g) is an Euclidean space.

• 한국수학사학회지
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• 제33권3호
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• pp.155-165
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• 2020

Pythagorean theorem is a proposition on the relationship between the lengths of three sides of a right triangle. It is well known that Pythagorean theorem for Euclidean geometry deforms into an interesting form in non-Euclidean geometry. In this paper, we investigate a new perspective that replaces right triangles with 'proper triangles' so that Pythagorean theorem extends to non-Euclidean geometries without any modification. This is seen from the perspective that a rectangle is an equiangular quadrilateral, and a right triangle is a half of a rectangle. Surprisingly, a proper triangle (defined by Paolo Maraner), which is a half of an equiangular quadrilateral, satisfies Pythagorean theorem in many geometries, including hyperbolic geometry and spherical geometry.

• Journal of Welding and Joining
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• 제21권1호
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• pp.66-71
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• 2003

The release of residual stress by mechanical loading and unloading is often performed in the fabrication of box structure fur steel bridge. The proper degree of loading and unloading is significant at release method of residual stress by mechanical loading because that degree is changed by material and geometric shape of welded structure. Therefore, the simulation model that could exactly analyze the release of residual stress by mechanical loading is to be necessary. In this study, the non-linear behavior of weldments under external loading and unloading, such as the decrease and increase of structure stiffness, was investigated by monitoring of nominal stress and strain. Tensile loading and unloading test and the proper degree of stress relaxation was measured by sectioning technique using strain gauge. Analysis model that is indispensable for the effective application of MSR method was established on the basis of test and measurement result.

• 대한수학회보
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• 제50권6호
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• pp.2079-2087
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• 2013

An $\mathcal{SQNS}$-group G is a group in which every proper subgroup of G is either s-quasinormal or self-normalizing and a minimal non-$\mathcal{SQNS}$-group is a group which is not an $\mathcal{SQNS}$-group but all of whose proper subgroups are $\mathcal{SQNS}$-groups. In this note all the finite minimal non-$\mathcal{SQNS}$-groups are determined.

• 농촌의학ㆍ지역보건
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• 제31권3호
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• pp.255-262
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• 2006

영유아의 중요한 양육 항목의 올바른 실천율이 전체 항목의 약 60-70%에 불과하였고, 예방접종 프로그램에 겸하여 실시한 양육교육으로는 적극적인 교육이 이루어질 수 없어 교육 효과가 충분하지 않은 것으로 나타났으며, 영유아의 월령이 증가할수록 교육효과가 낮아 졌다. 전반적인 올바른 양육실천 정도를 높이고, 영유아의 월령 증가하더라도 어머니의 양육에 대한 관심을 지속 유지시킬 수 있으며, 교육 효과를 높일 수 있는 접근법을 모색하여 수행할 것을 제안하며, 수행되는 교육의 효과를 지속적으로 평가하는 과정을 통해 본 프로그램을 개선 발전시킨다면 부산지역 영유아의 올바른 양육 실천율이 높아질 수 있을 것으로 기대한다.