• 한국환경과학회지
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• 제16권5호
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• pp.583-591
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• 2007

In this study, meteorological characteristics concerning the occurrence of fog are analyzed using 4-years (2000-2003) data at Chuncheon. From the analysis of meteorological characteristics, the fog at Chuncheon occurred before sunrise time and disappeared after that time and lasted for 2-4 hours. When fog occurred, on the whole, wind direction was blew the northerly and wind speed was below 2.1 m/s. Especially, about 42 % of foggy day fell on the calm($0{\sim}0.2m/s$) conditions. The difference between air temperature and dew point temperature near the surface were mainly less than $2^{\circ}C$. For the lack of water surface temperature, the water sur-face temperature was calculated by using Water Quality River Reservoir System (WQRRS). In Chuncheon, there is close correlation between the frequency of fog day and outflow from Soyang reservoir and high frequency of occurrence due to the difference between air and cold outlet water temperature.

• 대한응급의학회지
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• 제29권6호
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• pp.603-615
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• 2018

Objective: We analyzed the association between regional weather and temporal changes on the daily occurrence of trauma emergencies and their severity. Methods: In this cross-sectional prospective study, we investigated daily atmospheric patterns in trauma episodes in 1,344 patients in Cheongju city, South Korea, from January 2016 to December 2016 and analyzed the association of trauma occurrence and Injury Severity Scores (ISS) with weather conditions on a daily scale. Results: The mean age of trauma patients was $53.0{\pm}23.8years$ and average ISS was $9.0{\pm}2.0$. Incidence of trauma was positively correlated with average temperature (r=0.512, P<0.001) and atmospheric pressure (r=0.332, P=0.010) and negatively correlated with air pollutants (particulate matter less than $2.5{\mu}m^3$ [PM2.5], r=-0.629, P<0.001; particulate matter less than $10{\mu}m^3$ [PM10], r=-0.679, P<0.001). ISS was not significantly correlated with climate parameters and air pollutants, and variability was observed in the frequency and severity of trauma by time of day (highest occurrence, 16-20 pm; highest ISS, 4-8 am), day of the week (highest occurrence and highest ISS, Saturday), month of the year (highest occurrence, July; highest ISS, November), and season (highest incidence, summer; highest ISS, autumn). Conclusion: The study shows a positive relationship between trauma occurrence and specific weather conditions, such as atmospheric temperature and pressure. There was a negative relationship between concentrations of PM2.5 or PM10, and trauma occurrence. However, no correlation was observed between weather conditions or the concentrations of air pollutants and ISS. In addition, seasonal, circaseptan, and circadian variations exist in trauma occurrence and severity. Thus, we suggest that evaluation of a larger, population-based data set is needed to further investigate and confirm these relationships.

• 한국지리정보학회지
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• 제14권3호
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• pp.150-162
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• 2011

우리나라에서는 최근 19년 동안에 연평균 448건의 산불이 발생하였다. 특히, 전체 산불발생건 수의 약 94%가 봄 가을철 건조계절에 동시다발적으로 빈번하게 발생하였다. 이는 국가적인 산림화재의 피해를 최소화하기 위해 산불을 효율적이고 체계적으로 관리하는 것이 필요하다. 본 연구에서는 최근 19년간 발생한 건조계절 산불을 1990년대와 2000년대로 나누어 순기에 따른 각 시군별 산불발생빈도의 시공간적 패턴을 GIS로 분석 후 1990년대 대비 2000년대의 순기별 산불발생빈도 변화 패턴을 비교 분석하였다. 분석 결과 1990년대와 2000년대에는 가장 높은 산불발생빈도를 나타낸 순기가 4월 초순으로 같았지만 이에 대한 지역별 산불발생빈도가 한반도 서쪽인 충청지역을 중심으로 대전에서 27건으로 가장 많이 증가하였고, 호남 및 인천지역에서 10건 이상 증가한 것으로 분석되었다. 그러나 강원 홍천에서는 4월 하순에 최대 12건이 감소한 것으로 나타났다. 본 연구를 통해 시기변화에 따라 이동하는 산불에 대한 지역별 맞춤형 산불방지대책 수립이 가능해질 것으로 판단된다.

• 한국수자원학회논문집
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• 제32권6호
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• pp.627-636
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• 1999

지구온난화의 영향으로 배증 CO2 상태가 되는 약 60년 후의 한반도 평균강수량은 약 5-10%정도의 증가로 예측되고 있다. 그러나 수자원분야에서 평균강수량의 증가보다 더 중요한 것은 홍수 또는 가뭄과 같은 극치기상의 빈도 변화이다. 현재 국제적으로 이러한 극치기상의 빈번한 발생이 지구온난화의 한 증거로 받아들여지고 있기는 하나 그 양상이 어떻게 되리라고는 예측되고 있지 않다. 따라서 본 연구에서는 그러한 변화 양상을 예측해 보기 위한 방법론을 제시해 보는 것을 목적으로 한다. 본 연구에서 사용한 방법은 Todorovic과 Woolhiser(1975), katz(1977) 등의 일강수분포 관련 연구를 토대로 하여 월/연강수량의 변화에 다른 일강수의 특성을 매개변수의 변화로 고려하고 이를 통해 일강수의 분포변화를 예측하는 것이다. 본 연구에서는 두 일강수량(10mm,50mm)을 임계치로 하여 월/연강수량의 변화에 따른 10mm이하 및 50mm이상의 발생확률을 조사하였다. 이러한 발생확률의 변화가 바로 가뭄과 홍수의 변화로 직결되지는 않으나 그 양상을 짐작하게 하는 좋은 지표가 될 수 있으리라 판단된다. 아울러 연강수량의 변화에 따른 일강수의 분포변화는 월강수의 변화를 고려하는 경우보다 그 정도가 작았으며, 특히 월강수량의 변화를 고려하는 경우 우기인 여름철에 그 발생빈도의 변화가 아주 큰 것으로 나타났다.

• 전기의세계
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• 제14권5호
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• pp.8-14
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• 1965

Because of the flat slope of the magnetic characteristic curves at high saturation, the transformer inrush current peakes may assume an extreme magnitude. Even though such is rarely any danger to the transformer itself, the currents can cause serious problems in associated apparatus. This paper has analyzed various limiting factors of excess inrush currents, and then has suggested how to determine the frequency of encountering the inrush current peaks higher than an arbitrarily chosen value by deriving the probability equations of inrush current occurrence.

• 한국군사과학기술학회지
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• 제10권3호
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• pp.62-70
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• 2007

Most design temperature of environmental test in korea is based on the standard of Department of Defense. There are few studies to establish temperature standard. Besides the representative environmental test guide 'MIL-STD-810F' encourage to tailor to generate the most relevant test data possible and to test to make a match of test environment with operational environment. Under these circumstances, it is irrational to comply with baseless daily cycle. Thus the study about design method of test temperature is essential. So, the daily cycles to be appropriate to the Korean peninsula was presented in this study. And this research shows how to derive two main element, frequency-of-occurrence and daily maximum (minimum) temperature in daily cycles, in case we can not find the daily cycle.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2002년도 춘계학술대회논문집
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• pp.219-223
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• 2002

Voltage and current signals during impulse tests on transformer are treated as non-stationary signals. A new method incorporating signal-processing method such as Wavelets and courier transform is proposed for failure identification. It is now possible to distinguish failure during impulse tests. The method is experimentally validated on a transformer winding. The wavelet transforms enables the detection of the time of occurrence of switching or failure events. After establishing the time of occurrence, the original waveform is split into two or more sections. The wavelet transform has ability to analysis the failure signal on time domain as well as frequency domain. Therefore, the wavelet transform is superior than courier transform to analysis the failure signal. In this paper, the fact was proved by real data which was achieved.

• 음성과학
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• 제8권4호
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• pp.75-86
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• 2001

This study explored the effectiveness of a hierarchical treatment of aphasic perseveration (TAP) program in a Korean client with transcortical sensory aphasia. The subject with 52% perserveration score (Korean version of Boston Naming Test : K-BNT) was 44 year-old female with MCA (Middle cerebral artery) infarction. The experimental design used was an alternating treatment design with the hierarchical TAP and conventional audio-visual stimulation. The frequency of occurrence of perseverative behaviors and correct response in naming performance were analyzed and compared. It was claimed that the hierarchical TAP was more effective in naming performance than conventional audio-visual stimulation in terms of correct naming response. The frequency of occurrence of perseverative behaviors was lower in hierarchical TAP but the difference was relatively small. Unlike in English, sentence completion task was no longer stimulable while unison speech was very stimulable among the specific strategies of TAP program in Korean. Therefore, it could be said that TAP is language-dependent.

• 한국군사과학기술학회지
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• 제13권2호
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• pp.227-234
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• 2010

When a weapon system is developed, climate elements such as temperature, rainfall, and so on have an effect on development costs and a developing period. Therefore, effects of environment and climate must be examined throughly before the design of weapon systems and be applied to their developments. And so, operational and storage requirements for weapon systems are determined and are applied to related tests through analyzing not only environmental factors such as vibration, shock, and so on, but also climate factors. In this paper, the distribution and the frequency of occurrence of rainfall were analyzed and were suggested as a good guide to determine standards of tests for weapon systems when it's raining.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.1725-1731
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• 2010

This paper aims to find out the statistical characteristics of the railroad accidents by weather phenomena. For this, It is investigated occurrence frequency of railroad accidents and operation obstacles from 1996 to 2008 in Korea using the KROIS data and Korea railroad accidents reports. The results are as follows; The occurrence frequency of railroad accidents and operation obstacles decrease gradually, and most of railroad accidents is a railroad traffic accidents. The amount of damages by a railroad weather-related accidents is higher than the one of the railroad accidents and operation obstacles. Weather events which is influenced the railroad weather-related accidents and incidents are rainfall, snowfall, lightning, strong winds. And they have occurred a railroad weather-related accidents and incidents, such as rail obstruction, signal failure, and power supply failure.