• Bulletin of the Korean Space Science Society
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• 2009.10a
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• pp.26.2-26.2
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• 2009

The Solar and Space Weather Research Group (SOS) in Korea Astronomy and Space Science Institute (KASI) is constructing the Space Weather Prediction Center since 2007. As a part of the project, we are developing automatic real-time system of the global 3-D magnetohydrodynamics (MHD) simulation. The MHD simulation model of earth's magnetosphere is designed as modified leap-frog scheme by T. Ogino, and it was parallelized by using message passing interface (MPI). Our work focuses on the automatic processing about simulation of 3-D MHD model and visualization of the simulation results. We used PC cluster to compute, and virtual reality modeling language (VRML) file format to visualize the MHD simulation. The system can show the variation of earth's magnetosphere by the solar wind in quasi real time. For data assimilation we used four parameters from ACE data; density, pressure, velocity of solar wind, and z component of interplanetary magnetic field (IMF). In this paper, we performed some initial tests and made a animation. The automatic real-time system will be valuable tool to understand the configuration of the solar-terrestrial environment for space weather research.

• Bulletin of the Korean Mathematical Society
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• v.50 no.3
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• pp.915-928
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• 2013

In this paper, we will provide an alternative proof to characterize the pointwise multipliers which maps a Sobolev space $\dot{H}^r(\mathb{R}^d)$ to its dual $\dot{H}^{-r}(\mathb{R}^d)$ in the case 0 < $r$ < $\frac{d}{2}$ by a simple application of the definition of fractional Sobolev space. The proof relies on a method introduced by Maz'ya-Verbitsky [9] to prove the same result.

• Journal of applied mathematics & informatics
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• v.5 no.1
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• pp.223-233
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• 1998

This paper is concerned with the problem of existence of solutions to the initial value problem u'(t) = A(t, u(t)), u(a) = z in a probabilistic normed space where $A : [a,b)\;{\times}\;D->E$ is continuous, D is a closed subset of a probabilistic normed space E, and $z\;{\in}\;D$. With a dissipative type condition on A, we estabilish sufficient conditions for this initial value problem to have a solution.

• Communications of the Korean Mathematical Society
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• v.24 no.4
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• pp.561-564
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• 2009

A holomorphic function space in the unit disc D satisfying $\int_D|f'(z)|^p(1-|z|^2)^{p-1}dA(z)$<$\infty$ is quite close to $H^p$. The problems on the existence of the radial limits are considered for this space. It is proved that the situation for p > 2 is totally different from the situation for p $\leq$ 2.

• Journal of the Korean School Mathematics Society
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• v.13 no.4
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• pp.595-618
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• 2010

To grow as talents with future oriented knowledge and creativity, students need imaginative power and creativeness, and to that end, mathematics and science subjects may help. Students need activities that help gain explorative mind for new things, concentrating ability, researching ability and creativeness, and such attributes can be improved through the activities of making various shapes utilizing space geometry in 4D-frame. Such activities not only contribute to defining ability in mathematics but also cherish the qualifications required as architects and space scientists.

• Journal of Korea Multimedia Society
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• v.24 no.5
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• pp.629-641
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• 2021

Crowd behavior simulations have been studied to further accelerated and refined by parallelism by inducing agent-interacting forces into the image field representing the forces of attraction and repulsion. However, it was difficult to consider rapidly changing environments such as fire situations in buildings because texture images must be generated in advance simulation starts and simulations can only be performed in 2D spaces. In this paper, we propose a crowd agent behavior simulation method based on agent's 3D affordance field for flexible agent behavior in variable geomorphological environments in 3D space. The proposed method generates 3D affordance field related to agents and sensors in 3D space and defines the agent behavior in 3D space for the crowd behavior simulation based on an image-inducing field to a 3D space. Experimental results verified that our method enables the development of large-scale crowd behavior simulations that are flexible to various fire evacuation situations in 3D virtual spaces.

• Journal of Astronomy and Space Sciences
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• v.41 no.1
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• pp.43-60
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• 2024

Korea Pathfinder Lunar Orbiter (KPLO) is South Korea's first space exploration mission, developed by the Korea Aerospace Research Institute. It aims to develop technologies for lunar exploration, explore lunar science, and test new technologies. KPLO was launched on August 5, 2022, by a Falcon-9 launch vehicle from cape canaveral space force station (CCSFS) in the United States and placed on a ballistic lunar transfer (BLT) trajectory. A total of four trajectory correction maneuvers were performed during the approximately 4.5-month trans-lunar cruise phase to reach the Moon. Starting with the first lunar orbit insertion (LOI) maneuver on December 16, the spacecraft performed a total of three maneuvers before arriving at the lunar mission orbit, at an altitude of 100 kilometers, on December 27, 2022. After entering lunar orbit, the commissioning phase validated the operation of the mission mode, in which the payload is oriented toward the center of the Moon. After completing about one month of commissioning, normal mission operations began, and each payload successfully performed its planned mission. All of the spacecraft operations that KPLO performs from launch to normal operations were designed through the system operations design process. This includes operations that are automatically initiated post-separation from the launch vehicle, as well as those in lunar transfer orbit and lunar mission orbit. Key operational procedures such as the spacecraft's initial checkout, trajectory correction maneuvers, LOI, and commissioning were developed during the early operation preparation phase. These procedures were executed effectively during both the early and normal operation phases. The successful execution of these operations confirms the robust verification of the system operation.

• Bulletin of the Korean Mathematical Society
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• v.47 no.3
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• pp.527-540
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• 2010

We characterize the boundedness and compactness of the weighted composition operator on the logarithmic Bloch space $\mathcal{L}\ss=\{f{\in}H(D):sup_D(1-|z|^2)ln(\frac{2}{1-|z|})|f'(z)|$<+$\infty$ and the little logarithmic Bloch space ${\mathcal{L}\ss_0$. The results generalize the known corresponding results on the composition operator and the pointwise multiplier on the logarithmic Bloch space ${\mathcal{L}\ss$ and the little logarithmic Bloch space ${\mathcal{L}\ss_0$.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.645-648
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• 2008

Due to the rapid increase super high-rise buildings and multi-complex spaces, the space of a staged a very complex and variety of situations occur in the space of the building. The management is still based on limited information obtained by the administrator depends on the decision is made. However, the ability of human beings during a limited time, analysis limited information, and there is a limit to take the appropriate action and situation. To overcome these limitations high information technology that can be fused to take advantage of ubiquitous system is to offer. The aim of this study is on object-oriented 3D data and collected information about the status of the 3D data extraction, to exchange data between systems, the use of object-oriented 3D data, and I studied common space information of a multi-use facilities extracted from 3D CAD information to send to the GIS system.

• The Bulletin of The Korean Astronomical Society
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• v.46 no.2
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• pp.60.3-60.3
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• 2021

Squeezed vacuum injection을 이용한 중력파 검출기의 관측감도 향상 기술은 중력파 검출기 광신호의 양자 잡음을 제어하여 관측감도를 높이는 기술로 이론적으로는 10dB에 가까운 신호 대 잡음비 향상을 달성할 수 있다. 실험실 환경에서는 이미 10dB 이상의 신호 대 잡음비 향상을 달성했으며 실제 중력파 검출기에서는 GEO600의 6dB의 신호 대 잡음비 향상이 현재까지 가장 높은 수준이다. 한국천문연구원에서는 2019년부터 차세대 중력파 검출기 기술개발로 1064 nm 파장의 squeezer 개발을 추진했으며 현재 parametric down conversion을 이용해 squeezed vacuum을 생성하는 공진기를 제작하여 시험하는 단계에 있다. 이 발표에서는 한국천문연구원의 1064 nm squeezer 개발 연구와 개발 현황에 대해 소개하고자 한다.