• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.112.1-112.1
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• 2012

We have investigated the relationship between EUV coronal jets and bright points observed by Solar Dynamic Observatory (SDO)/Atmospheric Imaging Assembly (AIA). For this we consider 39 EUV coronal jets from May 2010 to July 2011 in 171 A identified by Heliophysics Events Knowledgebase (HEK) which provides an automatic identification of coronal jets. We look for coronal jet-bright point pairs as follows. First, we select the size of event area as 360 arcsec * 360 arcsec where the coronal jets are located at the center of the area. Second, we select jet-bright point pairs in case that they are located at the same position or just adjacent. Third, we select jet-bright point pairs that are connected by loops each other. Otherwise, we select jet-bright points pairs as the nearest one. As a result, we present 19 coronal jet-bright point pairs. The mean distance of these pairs is 77.24 arcsec. According to their distance and morphological connection, we classify the following three groups: 1) Adjacent (6 events), 2) Loop connected (5 events), and 3) Not connected in appearance (8 events). The histogram of mutual distance has two peaks; the first peak corresponds to the first group and the other one to the second group. We compare these events with previous observations and theoretical models as well as discuss possible physical connections between jets and bright points.

• The Bulletin of The Korean Astronomical Society
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• v.44 no.1
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• pp.51.3-51.3
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• 2019

Solar magnetograms are important for studying solar activity and predicting space weather disturbances1. Farside magnetograms can be constructed from local helioseismology without any farside data2-4, but their quality is lower than that of typical frontside magnetograms. Here we generate farside solar magnetograms from STEREO/Extreme UltraViolet Imager (EUVI) $304-{\AA}$ images using a deep learning model based on conditional generative adversarial networks (cGANs). We train the model using pairs of Solar Dynamics Observatory (SDO)/Atmospheric Imaging Assembly (AIA) $304-{\AA}$ images and SDO/Helioseismic and Magnetic Imager (HMI) magnetograms taken from 2011 to 2017 except for September and October each year. We evaluate the model by comparing pairs of SDO/HMI magnetograms and cGAN-generated magnetograms in September and October. Our method successfully generates frontside solar magnetograms from SDO/AIA $304-{\AA}$ images and these are similar to those of the SDO/HMI, with Hale-patterned active regions being well replicated. Thus we can monitor the temporal evolution of magnetic fields from the farside to the frontside of the Sun using SDO/HMI and farside magnetograms generated by our model when farside extreme-ultraviolet data are available. This study presents an application of image-to-image translation based on cGANs to scientific data.

• Korean Journal of Materials Research
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• v.6 no.1
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• pp.84-89
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• 1996

분자선 증착법(Molecular Beam Epitaxy)에 의하여 성장시킨 고농도 InGaAs layer에서 성장중지법이 계면 거칠기에 미치는 영향이 연구되었다. 계면을 평활화하기 위하여 단원자층의 GaAs 또는 AIAs를 InGaAs alyer 양쪽 계면에 증착한 뒤 뒤이어 성장중지를 실시하였다. Photoluminescence(PL) 측정에 의하면, 단원자 GaAs층 증착을 통한 평활화법보다 상당히 향상된 계면조건을 보여졌다. 고 분해능 단면 전자현미경법(Cross-section high resolution transmission electron microscopy, XHRTEM)에 의해 관찰되어진바, 계면 평활화법에 의해 계면의 평활성, 연속성 및 결정결함 밀도등에서 현저한 향상이 얻어졌다.

• The Bulletin of The Korean Astronomical Society
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• v.40 no.1
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• pp.66.2-66.2
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• 2015

In today's age when telecommunications using satellite has become part of our daily lives, one has to be employ preventive measures to avert any possible danger, of which solar activity is the major cause. Coronal mass ejections (CMEs) heading towards the Earth can lead to disturbances in the Earth's magnetosphere, if their magnetic field is oriented southward. Monitoring of solar filaments in this case becomes very very crucial, as their eruption is associated with most of the CMEs. Monitoring of solar filaments in this case becomes very very crucial, as their eruption is associated with most of the CMEs. Also, filaments show activation up to a few hours prior to launch of a CME and thus can provide advance warning. In this study, we present an algorithm for the detection of solar filaments seen in the extreme ultraviolet (EUV) from Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory (SDO). Various morphological operations are employed to identify and extract the filaments. These filaments are then tracked in order to determine their size and location continuously.

• The Bulletin of The Korean Astronomical Society
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• v.40 no.1
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• pp.85.1-85.1
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• 2015

We investigate the mass and energy of erupting plasma observed in X-rays and EUV, which is associated with a coronal mass ejection (CME) and an X-class flare. The erupting plasma was observed by both the X-ray telescope (XRT) on Hinode and the Atmospheric Imaging Assembly (AIA) on Solar Dynamic Observatory (SDO). We estimate the emission measures of the erupting plasma using a differential emission measure method. The plasma erupts with a loop-like structure in X-ray and EUV. We estimate the mass of erupting plasma assuming a cylinder structure. In addition, we estimate the radiative loss, thermal conduction, thermal, and kinetic energies of the eruptive hot plasma. We find that the thermal conduction timescale is much shorter than the duration of the eruption. This result implies that additional heating during the eruption may be required to explain the hot plasma observations in X-rays.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.2
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• pp.55-67
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• 2003

본 고에서는 차세대 무선통신용 초소형 단말기 구현에서 RF 시스템의 성능 개선에 크게 기여하게 될 RF 집적형 안테나 기술 현황과 향후 발전 방향이 제시된다. 고성능을 유지하면서 초소형 RF 전치단을 실현하기 위한 능동소자와 안테나가 결합하여 복합 기능을 하는 능동 집적 안테나(AIA, Active Integrated Antenna) 기술 현황, RF 시스템 단일 패키지(RF-SOP, System On Package) 형태에 집적 가능한 안테나 및 미래의 꿈인 RF 시스템 단일 칩 (RF-SOC, System On Chip)을 향한 단일 칩 안테나 (AOC, antenna on chip) 기술 동향 등이 기술된다.

• The Bulletin of The Korean Astronomical Society
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• v.42 no.2
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• pp.82.1-82.1
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• 2017

After a coronal mass ejection occur, plasma blobs are often observed along the post-CME ray. Searching for features related to the plasma blobs would be important in understanding their origin. We investigated the morphology of solar flares at EUV wavelengths, around the estimated times when blobs were formed. We focused on three events - 2013 September 21 and 22, 2015 March 7 and 8, and 2017 July 13 and 14 - observed by Atmospheric Imaging Assembly (AIA) aboard Solar Dynamic Observatory (SDO). Around the blob ejection times on 2013 September 21 and 22 and 2017 July 13 and14, we found regions with recurrent events of pronounced flux increase in EUV images. Around those of 2015 March 7 and 8, however, we could not observe such recurrent flux increase. This illustrates that even though blob ejections along different post-CME rays look similar in the high corona, the assocated features in the low corona may differ. We conclude that magnetic morphology and CME triggering process should be carefully examined in order to classify plasma blobs by their nature.

• International Journal of High-Rise Buildings
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• v.7 no.1
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• pp.65-73
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• 2018

Increasingly, mixed-use, multi-program complexes are emerging as the standard development model around the world. As their prominence grows, these projects are becoming increasingly complex. Program adjacencies are ever more intertwined as developers (and the architects who support them) are becoming more comfortable blurring the traditional boundaries between office, retail, residential and hospitality. This article discusses a second generation of mixed-use projects that embrace this hybridization, honing in on supertall architecture, their hybrid program offerings, and innovative sky lobbies. It concludes that programmatic advancements will continue to expand and find integration within single structures, both repositioned and built from the ground up.

• International Journal of High-Rise Buildings
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• v.6 no.4
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• pp.307-313
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• 2017

This paper outlines the processes and strategies studied and selected by the team during the design stages of the project for the incorporation of BIPV into the tower's façade. The goal was to create a system that helps reduce internal heating and cooling loads while collecting energy through photovoltaic panels located throughout the building. The process used to develop this façade system can be broken down into three stages. 1. Concept: BIPV as design catalyst for a high-rise building. 2. Optimization: Balancing BIPV and Human comfort. 3. Integration: Incorporating BIPV into a custom curtain wall design. The FKI Project clearly illustrates the evolution building enclosures from simple wall systems to high performance integrated architectural and engineering design solutions. This design process and execution of this project represent the design philosophy of our firm.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.131.2-131.2
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• 2012

태양전파폭발위치감지기(KSRBL)는 단일 안테나 전파분광기로써 미 뉴저지공과대학과의 협력으로 2009년 8월에 한국천문연구원에 개발 설치되었다. 1 MHz 스펙트럼 분해능과 1초의 시간 분해능을 가지고 있고 관측할 수 있는 주파수 대역은 245, 410 MHz 와 0.5-18 GHz에 이르는 광대역이다. 또한 태양 전면 태양 폭발 위치를 감지할 수 있다. 전파 관측은 LabVIEW와 IDL 프로그램에 의해 미리 짜여진 관측 스케줄에 따라 매일 자동으로 진행된다. 데이터 분석을 위해 필요한 플럭스, 안테나, 전파 이득에 대한 눈금조정 작업을 위한 소프트웨어를 개발하였다. 2009년 설치이후 지금까지 12개의 이벤트를 관측하였고 그 중 5개의 이벤트를 가지고 관측된 스펙트럼의 모듈레이션 패턴을 분석하여 태양면상에서 전파 폭발의 위치 값을 구했다. Solar Dynamics Observatory(SDO) AIA 이미지와 비교해 KSRBL의 위치감지 성능을 분석하였다.