• 한국음향학회:학술대회논문집
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• 한국음향학회 1999년도 학술발표대회 논문집 제18권 2호
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• pp.257-260
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• 1999

본 연구에서는 압전형 쇄석기에 의한 충격파 조사시에 초점위치 및 파쇄정도에 따른 파쇄대상물의 진동과 그 때 들려오는 방사음과의 관계에 대하여 검토해 본 시뮬레이션 결과를 제시한다. 아울러 동일한 실험을 파쇄가능한 대상물에 시행하여 진동과 파쇄효율과의 관계에 대해서도 실험적으로 검토한다. 최종적으로 압전형 쇄석기로 충격파를 대상물에 조사할 때, 충격시의 방사음과 대상물의 진동 및 그것에 따른 파쇄효율의 전체적인 상관성에 대하여 고찰한다.

• 천문학회보
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• 제38권2호
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• pp.99-99
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• 2013

If the magnetic field is extremely strong, as in pulsar/black hole magnetospheres, the Alfven speed approaches to the speed of light and we need relativity to describe interactions of Alfvenic waves. In this poster, we discuss physics of Alfvenic turbulence in this limit. We first discuss interaction of Alfvenic wave packets and scaling relations of resulting turbulence. Then we show results of numerical simulations. Finally we compare relativistic Alfvenic turbulence and its Newtonian counterpart.

• 대한수학회논문집
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• 제10권1호
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• pp.163-173
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• 1995

Inspired in [2,9,10,17], pp. E. Ehrlich and S. B. Kim in [4] cultivated the Riccati equation related to the Raychaudhuri equation of General Relativity for the stable Jacobi tensor along the geodesics to extend the Hawking-Penrose conjugacy theorem to $$ f(t) = Ric(c(t)',c'(t)) + tr(\sigma(A)^2) $$ where $\sigma(A)$ is the shear tensor of A for the stable Jacobi tensor A with $A(t_0) = Id$ along the complete Riemannian or complete nonspacelike geodesics c.

• Kyungpook Mathematical Journal
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• 제58권2호
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• pp.361-375
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• 2018

The object of the present paper is to study super quasi-Einstein manifolds. Some geometric properties of super quasi-Einstein manifolds have been studied. We also discuss $S(QE)_4$ spacetime with space-matter tensor and some properties related to it. Finally, we construct an example of a super quasi-Einstein spacetime.

• 한국언어정보학회:학술대회논문집
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• 한국언어정보학회 2002년도 학술대회 발표논문집
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• pp.98-118
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• 2002

Comparing the uses of '-canh-' with the ones of '-ci,'this study suggests that different modal interpretat ions by '-canh-' and '-ci' is based on the interpersonal relationship between speaker and interlocutor. While noting that '-canh-' and '-ci' are the modal indicators denoting degrees of speaker commitment, for making clear the illocutionary force of utterances, it is observed and explained that what the speaker is committed respectively by using '-canh-' and '-ci' is highly sensitive to the relativity of the known/unknown status of the informal ion introduced into discourse contexts .

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2002년도 가을 학술발표논문집 Vol.29 No.2 (2)
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• pp.46-48
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• 2002

현재 소프트웨어 개발에서 증가적으로 채택되고 있는 컴포넌트 기반 소프트웨어 엔지니어링(CBSE)에서, 새로운 프레임 ？에서의 컴포넌트의 효율적인 동작을 위한 컴포넌트 변형이나, 컴포넌트 통합은 활발히 연구가 진행중이나, 변형이나 통합으로 인하여 발생 할 수 있는 오류들을 테스팅하는 방법이과, 툴은 부족한 현실이다. 본 논문에서는 컴포넌트의 통합, 변경시 발생할수 있는 에러들을 쉽게 검출하기 위하여 본 논문에서 제안한 CCG(Component Calling Graph)를 이용하여 컴포넌트간의 의존성을 추적하고 selection 알고리즘을 거친 테스트 케이스 추출을 통한 컴포넌트의 효율적인 테스팅 방법을 제안하였다.

• 천문학회보
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• 제39권1호
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• pp.77.1-77.1
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• 2014

Gravitational waves predicted by the general relativity almost 100 years ago have been implicated indirectly only by astrophysical observations such as the orbital evolution of binary pulsars. The advanced detectors of gravitational waves will become operational in a few years and they are expected to make direct detection of gravitational wave signal coming from merging of binaries composed of neutron stars or stellar mass black holes from external galaxies. Korean Gravitational Wave Group (KGWG) is contributing to the possible detection through the data analysis of LIGO and Virgo. We summarize the perspectives of the gravitational wave research and the impacts of the detection in the near future in astronomy and astrophysics.

• 대한수학회지
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• 제38권4호
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• pp.843-852
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• 2001

In this lecture I shall discuss some recent progress in the development of methods for attacking the central questions of the formation and structure of singularities and of global regularity for solutions of the Cauchy problem for nonlinear systems of partial differential equations of hyperbolic type. Applications to the Einstein equations of general relativity and to the equations of compressible fluid flow shall be particularly emphasized and detailed.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2003년도 학술대회논문집
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• pp.373-376
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• 2003

A new method measuring soil resistivity in frequency range of 5-500[KHz] using variable frequency inverter was presented, and soil resistivity was analysed by resistive and reactive components on the basis of magnitude and phase of measured ground impedance. The test lead arrangement was proposed to reduce the inductive coupling in test circuit for measuring the soil resistivity. The frequency dependence of soil resistivity was mainly caused by the inductive current flowing through grounding conductors over the frequency of 70[KHz].

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1999년도 추계학술대회 논문집
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• pp.51-54
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• 1999

In this paper, the relativities, and the properties of various contaminants, which could give significant decrease in electrical insulation strength were investigated. For this investigation, the contamination degree was manually measured with brush-wiping method, and the ingredient of some specific sample was analyzed with ICP/MS. With the result, the influence of distance from sea, climatic condition contamination was investigated. And the difference in electrical properties of various salts in aquous solution was determined. Finally, we could get several significant result on the relativity and properties of contamination in various conditions