• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 2010년도 한국우주과학회보 제19권1호
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• pp.38.3-39
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• 2010

While major solar proton events (SPEs) come from the coronal mass eject (CME)-driven shocks in solar wind, there are many evidences that potentiality of CMEs to generate SPEs depends on its early evolution near the Sun and on different solar activities observed around the CME liftoff time. To decipher origin of SPE release, we have investigated onset time comparison of the SPE with CME, metric type II radio burst, and hard X-ray flare. For this, we select 30 SPEs observed from 1997 to 2006 by using the particle instrument ERNE onboard SOHO, which allows proton flux anisotropy measurement in the energy range ~10 - 50MeV. Onset time of the SPEs is inferred by considering the energy-dependent proton transport time. As results, we found that (1) SPE onset time is comparable to that of type II but later than type III onset time and HXR start time, (2) SPE onset time is mostly later than the peak time of HXR flare, (3) almost half of the SPE onsets occurred after the HXR emission, and (4) there are two groups of CME height at the onset time of SPE; one is the height below 5 Rs (low corona) and the other is above 5Rs (high corona). In this talk, we will present the onset time comparison and discuss about the origin of the SPE onset.

• 한국화재소방학회논문지
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• 제17권2호
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• pp.25-34
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• 2003

본 연구에서는 파라핀 연소화염을 사용하여 침대침 및 구대구 전극배치에서 직류전압을 인가하였을 때, 대기압 공기의 플래시오버특성, 인가전압의 크기 및 극성에 따른 화염의 형상변화, 고온 연소화염의 열전리현상 및 플래시오버 특성에 미치는 상대공기밀도의 영향 등에 대해 조사하였다. 실험결과, 연소화염이 존재하면, 대기압 공기의 플래시오버특성은 매우 큰 영향을 받고 있다. 이는 전극의 형태에 따라 코로나풍과 쿨롱력이 작용함으로써 화염의 형상변화와 요동이 일어나기 때문이다. 또한 고온화염으로 인한 주변 공기의 상대공기밀도의 저하로 인해 플래시오버 특성은 더욱 낮아지고 있으며, 연소화염에 대한 열전리의 영향은 크지 않는 것으로 나타났다.

• 조명전기설비학회논문지
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• 제27권4호
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• pp.73-80
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• 2013

Breakdown characteristics of air in the vertical arrangement of line conductor and plane electrode in case of combustion flame on the plane electrode are examined by the application of AC. and DC voltages to the gap. In order to investigate the effect of paraffin flame on the breakdown characteristics of air, flashover voltages are measured according to the variation of the gap length and the horizontal distance between the flame and the line conductor. As the result of the experiment, flashover voltages are substantially lowered down to 29.8% in case of the AC voltage, and 16.1% in case of the negative DC voltage, when in the presence of the flame. from 100% when in the absence of flame. Flashover voltages of air in the range of smaller than 3㎝ at the horizontal distance are increased in the proportion of the gap length and the horizontal distance in case of both AC and negative DC voltages. But before the flashover occurs, the flame is extinguished by such corona wind that is produced from the line conductor when the gap length and the horizontal distance reach to a certain degree. The effect of relative air density and the phenomenon of thermal ionization are analysed as the reduction factors of flashover voltages, due to high temperature of the flame.

• Journal of Astronomy and Space Sciences
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• 제25권1호
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• pp.25-32
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• 2008

태양활동 극대기인 2000년의 ACE 위성 태양풍 관측자료를 이용한 행성간 충격파의 목록에서 충격파 유도체 따라 행성간 충격파를 분류하고 충격파 유도체별 물리적 특성을 조사하였다. 51개의 행성간 충격파 중에서 대부분은 자기구름 및 Ejecta로 대표되는 ICME와 고속풍(HSS)에 의해서 유도되었다. 산소이온비(O7/O6)로부터 유도된 온도 및 Thermal index($I_{th}$ 지수) 값 분석에 따르면, ICME는 태양 코로나의 고온물질 영역으로부터 생성됨을 알 수 있다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제48권2호
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• pp.117-126
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• 1999

The environmental impact of the KEPCO 765-kV transmission line was studied using a full scale test line in order to develop the design technology. Therefore this paper describes an environmental design summary of the audible noise, hum noise, wind noise, radio interference, TV interference and electric field measurement from the KEPRI 765-kV double circuit transmission test line with a bundle of $6-480mm^2$ conductors per phase. The analysis of the test results shows that 6-Rail and 6-Cardinal conductors bundle satisfy the audible noise criterion & TV interference under the stable rainy weather condition and the radio interference level under the fair weather. And the other items are also agreed with the design level criterion for KEPCO 765-kV transmission line.

• 조명전기설비학회논문지
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• 제26권4호
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• pp.82-87
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• 2012

In this paper, flashover characteristics of air in the vertical arrangement of cylinder-shaped rod and plane gap in the case of combustion flame on the plane electrode were examined under the application of a.c. and d.c. high-voltages. In order to investigate the effect of propane flame on the flashover characteristics of air, flashover voltages in accordance with the variation of the gap length and the horizontal distance between the flame and the high-voltage rod electrode were measured. As the result of the experiment, flashover voltages in the presence of the flame were substantially lowered than those in the absence of flame, and the polarity effects with the d.c. voltages on appeared owing to the flame. Flashover voltages of air were increased in the proportion of the gap length and the horizontal distance in the case of both a.c. and d.c. voltages, but the flame was extinguished by such corona wind that was produced from the rod electrode when the gap length and the horizontal distance reached to a certain degree.

• 조명전기설비학회논문지
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• 제24권5호
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• pp.152-159
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• 2010

가공전력선이 통과하는 지역에서 발생된 연소화염은 계통 섬락사고의 원인이 되고 있다. 본 논문에서는 연소화염에 의한 전력선의 절연내력 저하특성과 화염의 형상변화를 알아보기 위해, 직류 및 교류 전압 인가시 전력선을 모의한 대기압 공기 갭에 대한 섬락특성과 화염의 소화특성을 조사하였다. 실험 결과, 화염에 의한 섬락현상은 비교적 작은 갭에서 발생되었으며, 수평배치형 침대침 갭에서 교류 섬락전압의 상대값은 평균 37.3[%]인 것으로 나타나 화염이 없는 경우에 비해 크게 저하하였다. 갭 길이가 증가함에 따라 전극간 섬락이 발생되기 전에 침전극로부터 발생된 코로나풍에 의해 화염은 소화되는 현상이 나타났다.

• 천문학회보
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• 제37권2호
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• pp.115.1-115.1
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• 2012

The Ultraviolet Coronagraph Spectrometer on board the Solar and Heliospheric Observatory (SOHO) observes low ionization state coronal mass ejection plasma at ultraviolet wavelengths. The CME plasmas are often detected in O VI ($3{\times}10^5K$), C III ($8{\times}10^4K$), $Ly{\alpha}$, and $Ly{\beta}$. Earlier in situ observations by the Solar Wind Ion Composition Spectrometer (SWICS) on board Advanced Composition Explorer (ACE) have shown mostly high ionization state plasmas in interplanetary coronal mass ejections (ICME) events, which implies that most CME plasma is strongly heated during its expansion in solar corona. In this analysis, we investigate whether the low ionization state CME plasmas observed by UVCS occupy small enough fractions of the CME volume to be consistent with the small fraction of ICMEs measured by ACE that show low ionization plasma, or whether the CME must be further ionized after passing the UVCS slit. To do this, we determine the covering factors of low ionization state plasma for 10 CME events. We find that the low ionization state plasmas in CMEs observed by UVCS show small covering factors. This result shows that the high ionization state ICME plasmas observed by the ACE results from a small filling factor of cool plasma. We also find that the low ionization state plasma volumes in faster CMEs are smaller than in slower CMEs. Most slow CMEs in this analysis are associated with a prominence eruption, while the faster CMEs are associated with X-class flares.

• 동의생리병리학회지
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• 제36권5호
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• pp.147-154
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• 2022

In order to secure practising rapid pattern(證, zheng) differentiation against acute infectious diseases like corona virus disease-19(COVID-19) showing rapid variation and contagion, a simplified classification of stages centering on the exterior-interior pattern identification with 2 step-subdivision by cold, heat, deficiency, excess pattern and pathogens is proposed. Pattern differentiation by compound patterns of 8 principles is made for the non-severe stage of general cold and the early mild stage of epidemic disease. Compound pattern's names of 8 principles about external infectious diseases are composed of three stages, that is disease site-characters-etiology. Based on early stage symptoms of fever or chilling etc., exterior, interior and half exterior and half interior patterns are determined first, and then cold, heat, deficiency, excess patterns of exterior and interior pattern respectively are determined, and then more concrete differentiation on pathogens of wind, dryness, dampness and dearth of qi, blood, yin, yang accompanied with constitutional and personal illness factors. Summarizing above descriptions, 4 patterns of exterior cold, exterior heat, exterior deficiency, exterior excess and their secondary compound patterns of exterior cold deficiency and exterior cold excess and so on are classified together with treatment method and available decoction for a standard measure of eight principle pattern differentiation.

• 한국정보전자통신기술학회논문지
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• 제14권4호
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• pp.328-337
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• 2021

석면, 벤젠과 같이 발암물질 1급인 미세먼지는 각종 질병에 원인이 되고 있다. 초 미세먼지 확산은 코로나 바이러스 확산의 중요한 원인중 하나이다. 본 논문은 2015년부터 2019년까지 서울시 평균 기온, 강수량, 평균 풍속등의 기상 데이터와 SO2, NO2, O3,등의 대기 환경 데이터를 기반으로 미세먼지와 초 미세먼지를 분석하고 예측한다. 계절별과 월별로 미세먼지와 초미세먼지 현황을 파악·분석하며 미세먼지를 예측하기 위해 기계학습 모델 중 선형회귀, SVM, 앙상블 모델을 이용하여 비교 분석하였다. 또한 미세먼지와 초 미세먼지 발생에 영향을 미치는 중요한 피쳐(속성)를 파악한다. 본 논문이 파악한 결과 3월에 가장 (초)미세먼지가 높았고, 8월에서 9월까지 (초)미세먼지가 가장 낮았다. 기상 데이터일 경우 (초)미세먼지에 가장 영향을 미치는 데이터가 평균 기온이며, 기상 데이터와 대기 환경 데이터일 경우 NO2가 (초)미세먼지 발생에 가장 크게 작용하였다.