• 대한지리학회지
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• 제41권4호
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• pp.435-456
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• 2006

본 연구에서는 일기온 자료를 바탕으로 사계절을 정의하여 지난 32년(1973-2004)동안 우리나라 장기간 평균적인 사계절의 개시일과 지속기간의 공간적 분포패턴 및 최근의 그 변화추세를 분석하였다. 공간적으로, 장기간 평균적인 봄철과 겨울철 개시일은 위도 및 해발고도의 영향을 받아 남-북(성산포-대관령)으로 각각 최고 44일과 63일의 차이를 보인다. 반면, 여름철 개시일은 위도보다는 해양과 해발고도의 영향을 받아 한반도 내륙지역에서 여름철이 제주도보다 일찍 시작된다. 사계절 지속기간에 따라 긴 계절부터 짧은 계절 순으로의 조합의 공간적 패턴을 살펴보면, 우리나라에는 특징적으로 5개의 계절주기 기후유형이 군집되어 나타난다. 한편, 최근 한반도에 나타난 기후변화가 계절주기에도 반영되어, 1980년대 후반 이후에 우리나라의 전체적으로 겨울철 개시일은 4일 늦어지고, 봄철 개시일은 6일 빨라져서 겨울철 길이가 10일 정도 짧아졌다. 이러한 겨울철 축소현상은 1980년 중반이후 남부지방에서 시작되어 1990년 접어들면서 북쪽으로 확대되어 한반도 전역에 걸쳐 나타났다. 인위적으로 콘크리트화가 진행된 우리나라 대도시 지역에서는 이러한 겨울철 축소현상이 더 뚜렷하게 나타났고, 심지어 여름철 지속기간도 국지적으로 증가하는 특징을 보였다. 이러한 한반도의 겨울철 축소현상은 추운계절 동반구 극지방($0-90^{\circ}E$, $65-85^{\circ}N$)의 지오포텐셜 고도장(925hPa) 변화와 원격상관이 있는 것으로 나타났다. 본 연구에서 밝혀진 우리나라 겨울철 지속기간의 감소현상은 최근 전 세계적인 기후변화의 시그널로 나타나는 겨울철 기온상승 추세와 일치하는 결과이다.

• Journal of Nutrition and Health
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• 제29권9호
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• pp.1003-1012
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• 1996

We examined the relationship among riboflavin intake, work activity, erythrocyte glutathione reductase activity coefficient(EGR AC)and urinary riboflavin excretion. We also attempted to determine factors affecting seasonal riboflavin status of rural women. All information about nutrient intake, work activity and riboflavin biochemical status was repeatly collected in three seasons ; farming season(June), harvest season(October), nonfarming season(February). EGR AC was negatively correlated with riboflavin intake(P<0.005) and positively correlated with the duration(min) of farming activity(P<0.005) and the percentage of lean body mass(LBM) (%) representing long term physical activity(P<0.05) in harvestseason. Urinary riboflavin excretion was positively correlated with the ratio of riboflavin intake to 1,000kcal of energy expenditure (P<0.05) in farming season and negatively correlated with the duration(min) of farming activity (P<0.05) and crude nitrogen balance(P<0.005) in harvest season. It appeared that EGR AC seems to increase and urinary riboflavin excretion seems to decrease as work activity increase. Therefore work activity would be expected to deteriorate riboflavin status. Multiple regression analysis of variables showed that in general EGR AC was affected by riboflavin and energy intakes, energy expenditure, energy balance, the duration(min) of farming activity, LBM (%). Urinary riboflavin excretion was affected by riboflavin and protein intakes, LBM(kg) and crude nitrogen balance. Crude nitrogen balance affected urinary riboflavin excretion in all seasons. The result indicated that work activity as well as nutrient intake seemed to affect riboflavin status, especially EGR AC was affected preferentially be work activity in all seasons.

• 한국농공학회논문집
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• 제61권1호
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• pp.61-74
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• 2019

In this study, the SPI (Standardized Precipitation Index) of meteorological drought and SDI (Streamflow Drought Index) of hydrological drought for 1, 3, 6, 9, and 12 months duration were estimated to analyse the characteristics of drought using rainfall and dam inflow data for Chungju dam ($6,661.8km^2$) with 31 years (1986-2016) and Boryeong dam ($163.6km^2$) watershed with 19 years (1998-2016) respectively. Using the estimated SPI and SDI, the drought forecasting was conducted using seasonal autoregressive integrated moving average (SARIMA) model for the 5 durations. For 2016 drought, the SARIMA had a good results for 3 and 6 months. For the 3 months SARIMA forecasting of SPI and SDI, the correlation coefficient of SPI3, SPI6, SPI12, SDI1, and SDI6 at Chungju Dam showed 0.960, 0.990, 0.999, 0.868, and 0.846, respectively. Also, for same duration forecasting of SPI and SDI at Boryeong Dam, the correlation coefficient of SPI3, SPI6, SDI3, SDI6, and SDI12 showed 0.999, 0.994, 0.999, 0.880, and 0.992, respectively. The SARIMA model showed the possibility to provide the future short-term SPI meteorological drought and the resulting SDI hydrological drought.

• 한국환경과학회지
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• 제9권4호
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• pp.303-309
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• 2000

The relationship between air temperature and sea surface temperature and studied using the daily air temperature and sea surface temperature data for 25 years (1970~1994) at 9 coastal stations in Korea. Seasonal variations of air temperature have larger amplitudes than those of sea surface temperature. The seasonal variations of air temperature leads those of sea surface temperature by 2 to 3 weeks. The anomalies of sea surface temperature and air temperature with time scales more than 1 month are more ghighly correlated than those of short term, with time scales less than 1 month. Accumulated monthly anomalies of sea surface temperature and air temperature for 6 months shwoed higher correlation than the anomailes of each month. The magnitudes of sea surface temperature and air temperature anomalies are related with the duration of anomalies. Their magnitudes are large when the durations of anomalies are long.

• 대한산업공학회지
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• 제39권6호
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• pp.546-553
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• 2013

A clear increase in the average annual temperature is observed worldwide, and climate changes take place in response to that increase. This affects not only the ecosystem, but also to mankind. Of all those aspects of climate change, people are especially interested in the length of each season, and people acknowledge that the duration of spring and fall has been shortened over the past several years. Still, it is difficult to observe this kind of phenomenon with the simple analysis of dividing the seasons and calculating the duration. Therefore, this study attempted to set up a more intuitive standard which well reflects the current situation. This study also divided the daily climate into 4 states using the daily maximum and minimum temperature. Moreover, using the Hidden Markov Model, this study calculated the duration of each season and analyzed its tendency based on the daily temperature data of the last 53 years (1960~2012). According to the result, the duration of spring and fall showed mild decreasing tendency over the past 53 years, and the duration of fall decreased even more during the past 30 years in the Korean peninsula. After 1960, the start of spring was advanced, which decreased the length of winter for about 11 days. On the other hand, the duration of summer increased for about 25 days, which is consistent with the worldwide tendency of temperature increase.

• 한국지구과학회지
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• 제34권4호
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• pp.356-367
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• 2013

교육대학교 1학년 164명을 대상으로 계절변화 원인에 대한 개념을 연구하였다. 이어서 개념의 특징에 따른 유형 분류와 천문관련 수업 후 개념변화를 알아보았다. 사전에 천문관련 선택형과 계절변화 원인에 관한 논술형 문항을 검사했고, 한 학기 동안 천문관련 학습 후에 같은 유형의 문항에 답하도록 하였다. 사전 검사의 계절변화 응답 내용에는 여러 종류의 개별 개념들이 들어있었고 이를 3단계의 위계로 나눌 수 있었다. 1차 원인은 지구의 상태와 운동에 관련된 우주적 관점, 2차원인은 1차 원인에 의해 지구가 받는 직접적 영향, 3차 원인은 2차 원인에 따라 지구 위의 관측자가 받는 영향으로 나누었다. 학생들이 사전검사에서 응답한 내용 중에는 1차 원인이 가장 많았으며 가장 적게 답한 개념은 2차 원인이었다. 하나의 답안을 이루는 전체 개념은 1차, 1-2차, 1-3차, 1-2-3차 원인 등의 유형이 나타났고 1-3차>1차>1-2차>1-2-3차 원인 등의 순으로 많았다. 2차 원인인 태양고도와 낮 길이 변화 개념을 가진 학생 수는 가장 적었으나 사전과 사후검사 모두 계절변화에 대한 과학적 개념을 가장 많이 가지고 있었고 천문관련 선택형 검사에서도 모두 점수가 높았다. 연구 결과, 계절 변화 원인에는 1차, 2차, 3차로 구분되는 위계 관계가 뚜렷하게 나타나고 있었다. 이에 따라 우주적 관점인 1차 원인을 먼저 가르쳐야 하지만 2차 원인인 태양 고도와 낮의 길이 개념에의 영향을 이해시킨 후 3차 원인을 학습시켜야 한다. 학생들이 이를 모두 이해했을 때 계절변화의 원인에 대해 비로소 정확한 개념이 생겼다고 말할 수 있을 것이다.

• 대기
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• 제34권2호
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• pp.97-106
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• 2024

The seasonal forecast skill of tropical cyclones (TCs) in the Northern Hemisphere from the Korea Meteorological Administration (KMA) Global Seasonal Forecast System version 6 (GloSea6) hindcast has been verified for the period 1993 to 2016. The operational climate prediction system at KMA was upgraded from GloSea5 to GloSea6 in 2022, therefore further validation was warranted for the seasonal predictability and variability of this new system for TC forecasts. In this study, we examine the frequency, track density, duration, and strength of TCs in the North Indian Ocean, the western North Pacific, the eastern North Pacific, and the North Atlantic against the best track data. This methodology follows a previous study covering the period 1996 to 2009 published in 2020. GloSea6 indicates a higher frequency of TC generation compared to observations in the western North Pacific and the eastern North Pacific, suggesting the possibility of more TC generation than GloSea5. Additionally, GloSea6 exhibits better interannual variability of TC frequency, which shows relatively good correlation with observations in the North Atlantic and the western North Pacific. Regarding TC intensity, GloSea6 still underestimates the minimum surface pressures and maximum wind speeds from TCs, as is common among most climate models due to lower horizontal resolutions. However, GloSea6 is likely capable of simulating slightly stronger TCs than GloSea5, partly attributed to more frequent 6-hourly outputs compared to the previous daily outputs.

• 한방비만학회지
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• 제17권1호
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• pp.10-19
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• 2017

Objectives: The aim of study was to investigate the effect of herbal medicine on obesity and to define which seasonal factor could be utilized to make an obesity treatment program more effective. Methods: Three hundred and forty-four subjects were recruited and data were analyzed for weight, body fat, muscular volume, body fat ratio, body mass index (BMI) change and treatment duration. At first, age classification was performed for the comparisons. Moreover, starting season of treatment was categorized to determine it's influence over the treatment. Results: It was found the administration of herbal medicine could diminish every analyzed fields of entire patients. Compared among age groups, there were no significant differences of all fields. However, the categorization of start season showed significant differences of weight, BMI change and treatment duration. In addition, the analysis of assumed 10% weight loss elicited patients started treatment in spring and winter should spend 12 and 13 weeks and summer would be 9.5 weeks. Conclusions: It was found herbal medicine would be effective for female obesity and expected patients could achieve 5.91 kg weight loss for 65.88 days treatment. Summer group had significant shorter treatment duration and it was presumed summer group had more concentration for achievement. Days required for assumed 10% weight loss was calculated to be 84 days in spring, 67 days in summer, 96 days in winter. Hereafter, further controlled study with more numbers of patients should be needed to determine the goal of medical treatment for obesity.

• 한국수자원학회논문집
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• 제35권1호
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• pp.109-124
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• 2002

본 연구는 간헐 수문사상인 시간강수계열의 구조적 특성을 고찰하여 강수발생의 군집성을 고려한 강수발생과정에 대한 추계학적 모의발생 모형을 개발한 것이다. 먼저 강수사상의 발생패턴을 기술하기 위해 Poisson 군집과정을 사용하였고, 이 과정에서 군집간의 시간과 군집내의 사상 수는 지수분포로 기술하였다. 둘째로 사상의 지속기간과 군집내에서 사상간의 시간은 음대수혼합분포로 기술하였다. 마지막으로 이상과 같은 시간강수사상의 발생패턴과 사상기간내의 강수의 종속구조를 구명하기 위해 서울을 대상으로 하여 실적강수자료를 분석하였다. Monte Carlo 모의결과는 모형이 강수발생의 계절적 패턴, 사상특성의 주변 및 조건부 분포를 잘 재현하고 있음을 보여주었다.

• 한국환경과학회지
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• 제33권1호
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• pp.43-57
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• 2024

The possible experimental time for cloud seeding was analyzed in South Korea. Rain gauge and radar precipitation data collected from September 2017 to August 2022 in from the three main target stations of cloud seeding experimentation (Daegwallyeong, Seoul, and Boryeong) were analyzed. In this study, the assumption that rainfall and cloud enhancement originating from the atmospheric updraft is a necessary condition for the cloud seeding experiment was applied. First, monthly and seasonal means of the precipitation duration and frequency were analyzed and cloud seeding experiments performed in the past were also reanalyzed. Results of analysis indicated that the experiments were possible during a monthly average of 7,025 minutes (117 times) in Daegwallyeong, 4,849 minutes (81 times) in Seoul, and 5,558 minutes (93 times) in Boryeong, if experimental limitations such as the insufficient availability of aircraft is not considered. The seasonal average results showed that the possible experimental time is the highest in summer at all three stations, which seems to be owing to the highest precipitable water in this period. Using the radar-converted precipitation data, the cloud seeding experiments were shown to be possible for 970-1,406 hours (11-16%) per year in these three regions in South Korea. This long possible experimental time suggests that longer duration, more than the previous period of 1 hour, cloud seeding experiments are available, and can contribute to achieving a large accumulated amount of enhanced rainfall.