높은 체감온도가 서울의 여름철 질병 사망자 증가에 미치는 영향, 1991-2000

최광용,최종남,권호장,Choi, Gwang-Yong,Choi, Jong-Nam,Kwon, Ho-Jang 대한예방의학회 2005 예방의학회지 Vol.38 No.3

Objectives : The aim of this paper was to examine the relationship between the summertime (June to August) heat index, which quantifies the bioclimatic apparent temperature in sultry weather, and the daily disease-related mortality in Seoul for the period from 1991 to 2000. Methods : The daily maximum (or minimum) summertime heat indices, which show synergetic apparent temperatures, were calculated from the six hourly temperatures and real time humidity data for Seoul from 1991 to 2000. The disease-related daily mortality was extracted with respect to types of disease, age and sex, etc. and compared with the time series of the daily heat indices. Results : The summertime mortality in 1994 exceeded the normal by 626 persons. Specifically, blood circulation-related and cancer-related mortalities increased in 1994 by 29.7% (224 persons) and 15.4% (107 persons), respectively, compared with those in 1993. Elderly persons, those above 65 years, were shown to be highly susceptible to strong heat waves, whereas the other age and sex-based groups showed no significant difference in mortality. In particular, a heat wave episode on the 22nd of July 2004 ($>45^{\circ}C$ daily heat index) resulted in double the normal number of mortalities after a lag time of 3 days. Specifically, blood circulation-related mortalities, such as cerebral infraction, were predominant causes. Overall, a critical mortality threshold was reached when the heat index exceeded approximately $37^{\circ}C$, which corresponds to human body temperature. A linear regression model based on the heat indices above $37^{\circ}C$, with a 3 day lag time, accounted for 63% of the abnormally increased mortality (${\geq}+2$ standard deviations). Conclusions : This study revealed that elderly persons, those over 65 years old, are more vulnerable to mortality due to abnormal heat waves in Seoul, Korea. When the daily maximum heat index exceeds approximately $37^{\circ}C$, blood circulation-related mortality significantly increases. A linear regression model, with respect to lag-time, showed that the heat index based on a human model is a more dependable indicator for the prediction of hot weather-related mortality than the ambient air temperature.

전신진동자극훈련을 병행한 PNF 결합패턴 훈련이 뇌졸중환자의 근력, 균형 및 보행에 미치는 효과

최광용,정희연,맹관철,Choi, Kwang-Yong,Jeong, Hee-Yeon,Maeng, Gwan-Cheol 대한고유수용성신경근촉진법학회 2017 PNF and Movement Vol.15 No.2

Purpose: The purpose of this study was to prove the effects of the PNF patterns combined with whole-body vibration (PWBV) training on muscle strength, balance, walking speed, and endurance in stroke patients. Methods: Sixteen subjects were randomly assigned to the PWBV group (n=8) and the whole-body vibration (WBV) group (n=8). The PWBV group performed PNF pattern exercises using sprinter combined with WBV, while the WBV group performed using squatting for 30 minutes. Both groups performed therapeutic interventions five days per week over a period of four weeks. The manual muscle test, timed up and go test (TUG), 10-meter walk test (10MWT), and six-minute walk test (6MWT) were used to assess the muscle strength, balance, and gait of the participants. The SPSS Ver. 19.0 statistical program was used for data processing. Statistical analysis included a pared t-test to compare the pre- and post-intervention, and an independent t-test was used to compare groups. The significance level was set as 0.05. Results: The PWBV group and WBV group showed significant improvements in the TUG, 10MWT, and 6MWT (P<0.05). Significant differences between the PWBV and WBV groups were found (P<0.05). Conclusion: The PWBV improved muscle strength, balance, gait speed, and endurance in stroke patients. Thus, PWBV may be suggested as a therapeutic intervention in patients with stroke hemiplegia.

승용차용 플라스틱 펜더의 사출성형해석과 열변형예측

최광용(K. Y. Choi),김영주(Y. J. Kim),김헌영(H. Y. Kim) 한국자동차공학회 1996 한국자동차공학회 춘 추계 학술대회 논문집 Vol.1996 No.11_1

This paper presents some results of analytical work focused on finding the optimal mold design predicting post-deformation in the analysis of heat resistance test. The procedure was applied to the injection molding process of front fender of passenger car. The warpage of product was obtained from the residual stress after filling. packing and cooling process and the post-deformation due to the heat resistance test could be calculated in the structural analysis of the product at the ejection temperature with the initial condition of residual stress. the boundary condition and heat resistance conditions. The analysis gave some useful guide lines in the design of automative plastic parts which should satisfy heat resistance regulation.

제주도 지역 체감온도 극한현상 발생 시 종관 기후 패턴

최광용(Gwangyong Choi) 건국대학교 기후연구소 2018 기후연구 Vol.13 No.2

The purpose of this study is to characterize the synoptic climatic patterns of extreme humansensible temperature (HST) events in Jeju Island, Korea under a subtropical climate condition as well as to examine their teleconnections with the large-scale climate systems. According to the extreme case analysis of the recent 30 years (1988-2017) data sets, the maximum daily average HST in the coastal areas of Jeju Island can rise up to about 40°C in mid-summer and even up to about 48°C during mid-daytime. These extreme HST events occur when the expansion of subtropical Pacific high pressure toward East Asia as well as the poleward shift of the Changma front provides hot and humid conditions over Jeju Island surrounded by seas, particularly in La Nina years with a positive (+) Arctic Oscillation mode. In contrast, the intensified western high and eastern low dipole pressure pattern in mid-winter, which accompanies the downward shear of upper tropospheric cold air toward the southern region of the Korean Peninsula under a negative (-) Arctic Oscillation mode, provides favorable conditions for frequent low HST extreme events. These conditions can lower daily average HST as much as -10°C in the coastal region of Jeju Island, and lower nighttime HST by -25°C on the peak areas of Mt. Halla due to wind chill effects. These findings will be used as a base for establishing prediction and warming systems of extreme HST events on Jeju Island, which is needed to mitigate the damage to the lives of Jeju residents and tourists under climate change.

판재성형 해석시 금형내의 공기거동 모델링

최광용(Kwang Yong Choi),김헌영(Heon Young Kim) 한국소성가공학회 2011 한국소성가공학회 학술대회 논문집 Vol.2011 No.5

Nowadays sheet metal forming simulation is widely used and essential for reducing lead time, saving cost and increasing surface quality in automotive and electrical field. During stamping process the air in die cavity, especially outer panel, can affect surface quality due to locally high compression of air between die and blank sheet. In order to prevent this problem, air vent holes are drilled by technician who has experience and know-how. CAE can be also used for analyzing the air behavior in die cavity during stamping process and needs two aspects. One is sheet modeling with elasto-plastic behavior and the other is air modeling with fluid dynamic behavior. This study is to analyzing sheet metal forming simulation with considering air behavior in die cavity. There can be 3 types of air modeling. One is simple model having linear relationship between bulk modulus and volume change, well-known fluid cell in hydroforming process. The other is ideal gas law model having uniform pressure and temperature in air domain, well-known standard airbag. The third is FPM(Finite point method) having non-constant variables in air domain. These modeling can make direct coupling of mechanical and air fluid behavior in sheet metal forming simulation and the CAE result can give the best idea to technician in analyzing optimized air vent hole’s position, size and number. For this study commercial S/W, PAM-STAMP™ and PAM-SAFE™, is used for direct mechanical and fluid coupling.

42V 시스템을 적용한 Mild-HEV 개발

최광용(Kwangyong Choi),이승현(Seunghyun Lee),김종대(Jongdae Kim),이상길(Sangkil Lee) 한국자동차공학회 2006 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

To meet the increasing market need for passenger comfort, safety and global environment protection, mild hybrid vehicles with 42V power system has been studied. This paper reviews the components of the vehicle, such as ISG, MCU, VCU, DC/DC converter, electric oil pump, belt drive system, etc. Also, vehicle control algorithm for ISG operation and supplementary devices control is presented. Fuel economy test of 42V mild-HEY is performed for CVS-75, MVEG-B and JAPAN 10ㆍ15 drive cycle and the results is analyzed.

금형 내 공기 거동을 고려한 자동차 외판의 판재 성형해석

최광용(Kwang Yong Choi),김윤창(Yun Chang Kim),최희관(Hee Kwan Choi),강철호(Chul Ho Kang),김헌영(Heon Young Kim) 한국소성가공학회 2013 한국소성가공학회 학술대회 논문집 Vol.2013 No.10

제주도 지역 체감온도의 시ㆍ공간적 분포 특징과 장기간 변화 경향

최광용 ( Gwangyong Choi ) 한국지리학회 2018 한국지리학회지 Vol.7 No.1

본 연구에서는 기상청 산하 기후관측소의 장기간 기후 자료에서 제주도 지역별 일별 체감온도(열지수, 바람냉각지수, 보통체감온도 지수) 자료를 구축하여 사계절 체감온도의 시공간적 패턴의 특징과 동아시아 몬순 시스템과의 관련성 및 장기간 변화추세 특징을 밝히고자 하였다. 장기간(1988∼2017년) 평균 연중 시계열 자료에 의하면 여름철 이외의 계절에는 제주도의 풍부한 바람의 영향에 의한 바람냉각 효과로 체감온도가 기온보다 더 낮아지는데, 특히 한겨울에는 체감온도가 기온보다 장기간 평균적으로 2.3∼5.8°C이상 낮아짐을 알 수 있다. 제주도 겨울철 체감온도는 시베리아 고기압의 강도 지수와 유의미한 음(-)의 상관성을 보였다. 반면 여름철 체감온도를 나타내는 열지수는 여름몬순에 의한 수증기 유입으로 한여름철에 공기온도보다 평균적으로 3.6∼4.6°C 정도 더 높아짐을 알 수 있다. 장기간 시계열 자료는 사계절 모두 제주도 체감온도 상승이 기온의 상승 경향보다 더 빠르게 진행되고 있음을 보여준다. 이러한 결과들은 특히 21세기 온난화에 의해 발생 가능한 재난 수준의 열파로부터 많은 제주 관광객들을 보호하기 위하여 여름철 체감온도에 대한 지속적인 모니터링을 해야 할 필요성이 있음을 가리킨다. In the present study, spatio-temporal patterns of seasonal apparent temperatures in Jeju Island, Korea and their associations with East Asian monsoon systems as well as their long-term changes were examined. To do this, daily apparent data sets consisting of heat index, windchill index and universal apparent temperature were reconstructed from long-term climate data sets archived by the Korea Meteorological Administration. According to the long-term (1988∼2017) average annual time-series data, the apparent temperature is lower than air the temperature due to the wind chill effect by the affluent wind of Jeju Island in the seasons other than the summer. In mid-wintertime, the climatological average of apparent temperature is lower than the temperature by 2.3∼5.8°C. The apparent temperature in winter in Jeju Island shows a significant negative correlation with the intensity of Siberia high pressure index. On the other hand, the climatological average of the apparent temperature in mid-summer becomes higher up to 3.6∼4.6°C than air temperature due to the inflow of moisture by summer monsoon. Long-term time series data show that the apparent temperature increase in Jeju Island has progressed faster than the air temperature rise trend. Overall, these results indicate that there is a need to constantly monitor the summer apparent temperature in order to protect a large number of Jeju tourists from the heat waves of disaster level that can occur in the warmer 21^st century.

제주 지역 주민 경제 활동 지원을 위한 수요자 맞춤형 기상·기후 정보 서비스 발굴

최광용 ( Gwangyong Choi ),박혜정 ( Hye-jeong Park ),허택산 ( Taiks-san Heo ) 한국지리학회 2016 한국지리학회지 Vol.5 No.2

본 연구에서는 최근 제주지역 주민에게 우선적으로 필요한 지역 주요 산업 활동을 고려한 수요자 맞춤형 기상·기후 정보서비스 항목을 발굴하는 것을 주요 목적으로 한다. 다양한 산업에 종사하는 주민 설문 조사를 실시한 결과, 제주 지역에서는 필요성, 시급성, 공익성, 수익성을 모두 고려할 때 지역 규모 태풍 피해 탐지 시스템이 가장 우선적으로 지역주민들이 필요로하는 서비스 항목임을 알 수 있다. 또한, 항공교통, 해운교통, 도심홍수, 산악 위험기상, 해양레포츠, 풍수해 보험, IT기반 관광정보, 가뭄 등의 정보를 제공하는 기상·기후시스템이 단기적으로 우선적으로 제공될 필요성이 있는 서비스 항목임을 알 수 있다. 이러한 수요자 설문에 기반하여 발굴된 기상·기후 서비스 항목들은 과거의 생산자 중심의 단순 기상 요소 정보 시스템에 비하여 지역주민의 경제 활동 증진에 큰 도움을 줄 것으로 예상된다. The purpose of this study is to identify the contents of user-customized weather and climate information services that the residents in Jeju, Korea need with priority for the improvements of local economic activities. Analyses of survey data from local residents demonstrate that among many services, the typhoon monitoring system at local levels is most needed by residents in Jeju for better performance of major economic activities including agriculture, fisheries and tourism. In addition, weather and climate information service systems that support aviation/navigation, urban flooding, mountain hazardous conditions, marin sports, insurance, IT-based tourism, droughts, crop production and wildland fires are recognized as important systems with higher priorities for local residents. These information obtained from local residents may help to establish the user-customized weather and climate information systems improving their economic activities compared to the conventional producer-centered ones displaying the simple observed weather and climate records.

우리나라 겨울철 극한저온현상 발생 시 종관 기후 패턴

최광용(Gwangyong Choi),김준수(Junsu Kim) 대한지리학회 2015 대한지리학회지 Vol.50 No.1

본 연구에서는 지난 40년 동안(1973~2012)의 우리나라 기상청 산하 61개 지점 일기온 자료와 NCEP/NCAR 재분석 자료를 바탕으로 우리나라 지역별 겨울철 극한저온현상 발생 시 동아시아 영역의 종관 기후 패턴의 특징을 밝히고자 하였다. 일최고기온과 일최저기온 하위 10 퍼센타일 기준으로 정의된 겨울철 극한저온현상은 주로 겨울철 전반기(12월 초순~1월 중순)에 2~7일 간격으로 우리나라 전역 또는 주요 산맥 기준 동서지역으로 구분되어 발생함을 알 수 있다. 해수면기압과 바람벡터 등의 지상 종관 자료 합성장 분석에 따르면 총 13개로 구분되는 우리나라 겨울철 극한저온현상 발생 공간 패턴은 산맥뿐만 아니라 시베리아 고기압과 알류샨 저기압의 상대적인 확장 범위와 강도와 밀접한 관련성이 있음을 알 수 있다. 대류권 중층(500 hPa) 종관기후도 분석에 따르면, 블러킹 형태의 저기압이 상층 찬 공기를 고위도 지역에서 한반도로 이류시킬 때 우리나라에 겨울철 극한저온현상이 발생하기에 적합한 조건이 형성됨을 알 수 있다. 이러한 결과들은 지역규모 이상의 동아시아 겨울철 극한저온현상 예보를 향상시키기 위해 시베리아 고기압, 알류샨 저기압, 상층 블러킹 등의 종관 기후 요소를 모니터링하는 것이 중요함을 가리킨다. The present study aims to characterize the synoptic climatic patterns of winter extreme low temperature events occurred in different regions of Korea based on daily temperature data observed at 61 weather stations under the supervision of the Korea Meteorological Administation and NCEP/ NCAR reanalysis I data for the recent 40 years (1973~2012) period. Analyses of daily maximum and minimum temperatures below 10th percentile thresholds show that high frequencies of winter extreme low temperature events appear across the entire regions of Korea or in either the western or eastern half region divided by major mountain ridges at the 2~7 dayintervals particularly in the first half of the winter period (before mid-January). Composite analyses of surface synoptic climatic data including sea level pressure and wind vector reveal that 13 regional types of winter extreme low temperature events in Korea are closely associated with the relative location and intensity of both the Siberian high pressure and the Aleutian low pressure systems as well as major mountain ridges. Investigations of mid-troposphere (500 hPa) synoptic climatic charts demonstrate that the blocking-like upper troposphere low pressure system advecting the cold air from the Arctic toward the Korean Peninsula may provide favorable synoptic conditions for the outbreaks of winter extreme low temperature events in Korea. These results indicate that the monitoring of synoptic scale climatic systems in East Asia including the Siberian high pressure system, the Aleutian low pressure system and upper level blocking system is critical to the improvement of the predictability of winter extreme low temperature events in Korea.