• Journal of Astronomy and Space Sciences
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• 제11권2호
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• pp.273-280
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• 1994

A linear method for determining three-dimensional motion of a rigid object is presented. In this method, two three-dimensional line correspondences are used. By using three-dimensional information of the features and observing that the rotation is unique regardless of the translation vector, the two components of motion parameters (rotation and translation) are computed separately. Also in this paper, the solution is given without a scale factor which is necessary in other methods that use only the two-dimensional projective constraints.

• 대한수학회지
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• 제34권1호
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• pp.23-42
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• 1997

A 6-dimensional sphere considered as a homogeneous space $G_2/SU(3)$ where $G_2$ is the group of automorphism of the octonians O. From this representation, we can define an almost comlex structure on a 6-dimensional sphere by making use of the vector cross product of the octonians. Also it is known that a homogeneous space $G_2/U(2)$ coincides with the Grassmann manifold of oriented 2-planes of a 7-dimensional Euclidean space.

• Journal of applied mathematics & informatics
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• 제5권3호
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• pp.839-848
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• 1998

We can obtain the concise description of two dimensional Finsler space from the viewpoint of their geodesic curves. In this paper we obtain the geodesic equations in a two-dimensional Finsler space with some special (${\alpha},\;{\beta}$)-metrics by using the Weierstrass form. We shall be referred to an isothermal coodinate system and an orthonormal one with respect to an associated Riemannian space.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2003년도 추계학술발표회 논문집
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• pp.211-218
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• 2003

The purpose of this study is to analyze the interior orientation, relative orientation, absolute orientation, space intersection, space resection, computing the orientation parameter, 3-dimensional coordinates by using the EXCE for educational purpose.

• 한국항공우주학회지
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• 제41권2호
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• pp.156-163
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• 2013

우주파편과의 위험성을 판단하는데 가장 보편적으로 사용되는 것이 충돌확률이며, 현재 널리 사용되고 있는 방법은 최근접거리를 이용한 2차원 선형 충돌확률 계산방법이다. 본 논문에서는 우리나라가 운용하거나 운용을 계획 중인 아리랑 2호, 3호, 5호 위성에 접근하는 물체의 접근 특성을 분석하고, 2차원 선형 충돌확률보다 더 정밀한 3차원 비선형 충돌확률의 특성을 STK/Nonlinear Collision Probability Tool을 이용하여 분석하였다. 이를 통해 저궤도 위성인 아리랑 위성들에 대해 3차원 비선형 충돌확률의 효용성에 대해 고찰하였다. 분석결과 3차원 비선형 충돌확률은 350m/s 이하의 상대속도 영역에서 효용성이 있음을 확인하였으며, 우리나라 위성의 경우 낮은 상대속도를 가지고 접근하는 경우가 거의 없는 것으로 나타나 실질적으로 3차원 비선형 충돌확률에 대한 효용성이 낮은 것으로 나타났다.

• Spatial Information Research
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• 제19권5호
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• pp.75-86
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• 2011

실세계의 도시에 대한 3차원 모델링은 도시계획과 의사결정을 하기 위하여 필수적인 작업이다. 또한 무선인터넷 발달과 함께 이용자의 위치를 파악하여 정보를 제공하는 위치기반서비스에 대한 소비자 증가로 많은 3차원 도시모델이 개발되고 있다. 특히 우리나라 도심지역의 경우에는 초고층 건물들의 밀집으로 실외뿐만 아니라 실내공간 모델링에 대한 연구가 필요하며, 공간 모델을 통해서 최단경로 등의 공간 분석이 통한 위치기반서비스가 제공될 수 있어야 한다. 지금까지 많은 연구가 진행된 3차원 도시모델들은 피처 모델로, 기본요소들(primitives)을 조합하여 공간을 표현하고, 관계성은 공유하는 기본요소들을 찾아야지만 표현할 수 있기 때문에 복잡한 3차원 공간 객체들 사이에서는 관계성을 정의하기 힘들다. 따라서 최단경로와 같이 공간간의 관계성을 기반으로 도출되는 공간 분석을 하기 위해서는 공간간의 관계성 표현이 필요하다. 본 연구에서는 복잡한 3차원 실내공간간의 관계성을 효율적으로 표현하는 네트워크 기반의 위상학적 데이터 모델인 보행 공간 관계 모델을 개발하였다.

• 한국조경학회지
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• 제25권3호
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• pp.56-65
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• 1997

This research was conducted to suggest some directions for desirable urban green space planning through 1) establishing a new classification system by examining the existing concept, problems and characteristics of green space and 2) defining the essence of green space environment and finding some analytical and evaluative methods through a clear establishment of functions, indicators of green space. In the research, measurements of the amount of green space was accompanied with measurements of green covered space, green volume, and the structure of greenery within the frame of vision. As result, three-dimensional measurement was possible, three-dimensional measurement was possible, which turned out to be more effective than the existing 2-dimensional measuring method. It is found that the ratio of green covered space is to proportional to the ratio of green volume in this study. Therefore in green space planning process it is desirable to consider the ratio of green volume all together.

• Applied Microscopy
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• 제45권3호
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• pp.115-118
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• 2015

In this review paper, I'd like to introduce the basics of angle-resolved photoemission spectroscopy (ARPES) and some of my results taken at the Pohang Accelerator Laboratory (PAL), the only synchrotron radiation in South Korea. The results show that ARPES is very useful, in particular, for studying two-dimensional materials. It looks like a microscope in momentum space similar to transmission electron microscope imaging atoms in real space.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 2011년도 한국우주과학회보 제20권1호
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• pp.28.2-28.2
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• 2011

Coronal Mass Ejections (CMEs) are enormous eruptions of plasma ejected from the Sun into interplanetary space, and mainly responsible for geomagnetic storms and solar energetic particle events. It is very important to infer their direction of propagation, speed and their 3-dimensional configurations in terms of space weather forecast. Two STEREO satellites provide us with 3-dimensional stereoscopic measurements. Using the STEREO observations, we can determine the 3-dimensional structure and radial velocity of the CME. In this study, we applied three different methods to the 2008 April 26 event: (1) Ice cream Cone Model by Xue (2005) using the SOHO/LASCO data, (2) Flux rope model by Thernisien (2009) using the STEREO/SECCHI data, (3) Flux rope model with zero angle using the STEREO/SECCHI data. The last method in which separation angle of flux rope is zero, is similar to the ice cream cone model morphologically. The comparison shows that the radial speeds from three methods are estimated to be about 750km/s and are within ${\pm}120km/s$. We will extend this comparison to other CMEs observed by STEREO and SOHO/LASCO.

• 대한수학회보
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• 제58권3호
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• pp.559-572
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• 2021

It is well known that every invariant harmonic function on the unit ball of the multi-dimensional complex space has the volume version of the invariant mean value property. In 1993 Ahern, Flores and Rudin first observed that the validity of the converse depends on the dimension of the underlying complex space. Later Lie and Shi obtained the analogues on the unit ball of multi-dimensional real space. In this paper we obtain the half-space analogues of the results of Liu and Shi.