• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.578-578
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• 2015

동아시아 지역의 대부분은 몬순의 영향으로 인해 수자원의 계절적 변동성이 크며 이로 인해 홍수 및 가뭄이 빈번하게 발생하고 있다. 기후변화에 따른 기온과 강수량의 변화는 수자원의 변동성을 더욱 악화시킬 수 있으며, 수재해 피해를 더욱 가중시킬 것으로 전망되고 있다. 본 연구에서는 기후변화에 따른 동아시아 지역의 기온 및 강수량의 변화를 전망하고, 그 특성을 분석하고자 한다. 이를 위해 CMIP5의 핵심실험인 2개 RCP시나리오(RCP4.5, RCP8.5)에 대한 다수의 GCMs 결과를 이용하였다. 구축한 기후시나리오를 이중선형보간법(bilinear interpolation)을 이용하여 공간적으로 상세화하였으며, Delta method를 이용하여 편의보정을 수행하였다. GCM 모의자료의 편의를 산정하기 위해 관측자료는 APHRODITE의 기온 및 강수량 자료를 이용하였다. GCM에 따라 차이가 나지만, 우리나라의 경우 평균적으로 100~300mm 정도 과소모의 되는 것으로 나타났다. 미래 기온 및 강수량 전망을 위해 과거기간은 1976~2005년, 미래기간은 2021~2050년(2040s), 2061~2090년(2070s)으로 구분하였다. 우리나라의 경우 RCP 4.5 하에서 연평균기온은 $1.4{\sim}1.7^{\circ}C$(2040s), $2.2{\sim}3.4^{\circ}C$(2070s) 정도 상승할 것으로 나타났으며, 연평균 강수량은 4.6~5.3% (2040s), 8.4~10.5% (2070s) 정도 증가할 것으로 나타났다. RCP 8.5에서는 연평균 기온은 RCP4.5에 비해 상승폭이 더 컸으며, 강수량은 유사한 결과가 나타났다. 또한, 동아시아 지역에서도 연평균 기온이 상승하고 연평균 강수량은 증가하는 것으로 나타났다. 다만, 지역별로 계절별 기온 및 강수량이 매우 다른 양상으로 나타났다. 이는 동아시아 지역과 같이 계절별 강수량 발생패턴이 다른 지역에서는 홍수 및 가뭄에 매우 중요한 역할을 할 것이다. 따라서 지역적으로 계절별 강수량의 변화를 분석해야 할 것으로 판단되며, 추후 유출량 모의를 기반으로 홍수 및 가뭄의 영향을 직접적으로 분석해야할 것으로 판단된다.

• The Journal of the Acoustical Society of Korea
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• v.21 no.3
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• pp.213-220
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• 2002

The sound wave in the sea propagates under the effect of water depth, sound velocity structure, sea surface and bottom roughness, and bottom sediment distribution. In particular the sound velocity structure in shallow water varies with time and space, an? the sediment distributes very variedly with place. In order to investigate the seasonal variation of low-frequency sound propagation in the Yellow Sea, the propagation experiments were conducted along the same track in the middle part of the Yellow Sea at various seasons of spring. summer, and autumn. In this paper we consider the measurement results on the propagation loss with the sound velocity structure, and investigate the seasonal variation of the propagation loss. As a result, the propagation losses measured in summer were larger than the losses in spring and autumn. And the propagation losses measured in autumn were smaller than the losses in spring. The seasonal change of the propagation loss increased with the rise of sound frequency and the propagation range.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.27 no.3
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• pp.170-177
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• 1991

This paper presents the seasonal variation of distribution and flushing time of the fresh water in Suyoung Bay based on the monthly observation from May 1989 through April 1990 and Pusan City Report of Suyoung Bay. Most of Suyoung river water was trapped inside of the bay west of the Dong-Baek Island located. Low salinity water lies dominantly on the right hand side of the Suyong river. Salinity structure of the bay is the well mixed type in summer and the partially mixed type in other season. The fresh water fraction varied in an exponetial manner from unity at the head of bay toward a value of zero at the its mouth. The calculated average flushing time during a year was about 10-15days. About 1.5 days was in summer because the strong fresh water discharge from the river was dominated in the bay.

• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.1420-1424
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• 2010

강수량의 계절성은 수자원관리에 있어 매우 중요한 수문요소로서 계절성의 변동을 정량적으로 평가하는 것은 미래 수자원관리 및 정책 수립에 필수적이다. 이러한 점에서 본 연구의 목적은 강수량의 계절성을 평가하는데 유리한 방법론을 제시하고, 이를 통한 계절 변동성의 정량적인 해석을 목적으로 한다. 본 연구에서 적용한 순환통계치 분석은 시간을 각도로 변환하여 이용함으로써 미세한 시간적인 변화양상의 정량적인 해석이 가능한 방법이다. 강수량의 주기특성과 과거로부터 현재까지의 변화 양상을 평가하기 위해서, 우선 전국의 58개 강우관측소를 선별하고 각 관측소의 일강우자료를 이용하여 관측소별 연최대치계열(Annual maxima series)과 발생일자, 월최대강수계열(Monthly maxima series)과 발생일자를 추출하였다. 각 자료의 발생일자는 순환통계분석을 위해 해당 time scale을 한 주기로 하는 방향각 데이터로 변환하였으며, 변환된 시간속성 데이터의 통계특성치를 산정하여 발생시기에 대한 경향성을 분석하였다. 월최대강수량의 발생 시기는 자료 계열 연주기의 변동성을 평가하기 위해 사용되었고, 분석결과 남해안지역이 6월말에서 7월초이고, 북쪽으로 올라감에 따라 조금씩 발생시기가 늦어지는 것으로 분석되었다. 극치강수량의 발생 경향을 평가하기 위해 사용된 일최대강수량의 시공간적 변동성은 월최대강수량보다 크게 분석되었으며, 이는 일최대강수량의 경우 지형학적인 영향에 크게 좌우되며, 우리나라의 여름철 극치강수량이 태풍 발생빈도 및 경로와 연관성을 갖는다는 일반적인 사실을 반영한 결과라고 판단된다. 월최대강수량 및 일최대강수량 발생시기의 이동평균을 통해 발생시기의 변동을 분석한 결과, 서울과 강릉지방은 최대강수량의 발생시점이 늦어지고 있으며 반대로 목포와 부산지방은 최대강수량의 발생시점이 앞당겨지고 있었다. 이는 몬순시스템의 거동에 영향을 받는 것으로 사료된다.

• The Journal of the Acoustical Society of Korea
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• v.26 no.7
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• pp.306-316
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• 2007

Based on a concept of soundscape, this study aims to investigate Koreans' preference for auditory elements, features, and impressions depending upon the season, and examine how these auditory factors of soundstape and seasons interact with each other and attempt to discover their influence on people's auditory preferences. According to an environmental psychological approach called the caption evaluation method, 45 college students examined the soundscape of Namwon City while racing the streets in four seasons. In order to analyze the interactions between seasons and such auditory factors as elements, features, and impressions, it was conducted the GLM univariate analysis and the NPAR tests for independent samples. The results of the analyses show that there are interactive effects between seasons and auditory factors like elements, features, and impressions and that the auditory factors have an effect on auditory preference. Moreover, as for seasonal preference for auditory elements, it was found that people prefer natural sound in spring, summer, and fall while they prefer social sound in winter. Concerning seasonal preference for auditory features, people place a focus on the behaviors in spring, summer, and winter while they stress the surroundings in autumn, as for seasonal preference for auditory impressions, they make much of sound characteristics in spring and winter but they value the atmosphere of streets in summer and fall. The results of this study can he utilized as useful data in determining which auditory factors among elements, features, and impressions to take into consideration in a soundscape design.

• Sleep Medicine and Psychophysiology
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• v.11 no.2
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• pp.95-99
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• 2004

Objectives: Although many studies on seasonal variations in mood and behavior have been carried out in foreign countries, no such study has previously been undertaken in Korea. The goal of this study was to estimate the frequency of seasonal variations in mood and behavior among Korean medical students. Methods: 297 medical students from Korea University College of Medicine participated in this study. The subjects were surveyed with a Korean translation of the Seasonal Pattern Assessment Questionnaire (SPAQ), and their responses were evaluated for seasonal patterns of mood and behavioral change, including seasonal affective disorder (SAD) and subsyndromal seasonal affective disorder (S-SAD), derived from the case-finding criteria of Kasper et al. Results: The mean global seasonality score was 6.6 (SD=3.6). 83.5% (N=248) of the subjects reported some changes in behavior and mood associated with the seasons. Only 3.7% (N=11) reported no behavioral changes across the seasons. Total prevalence rates were 15.2% for SAD, and 2.7% for S-SAD. The estimated frequencies were 3.0% for summer SAD, 2.7% for summer S-SAD, 11.4% for winter SAD, and 5.8% for winter S-SAD. The prevalence rates for winter SAD or S-SAD were higher than the prevalence rates for summer SAD or S-SAD. Conclusion: These results suggest that seasonal variations in mood and behavior are common among Koreans. The higher prevalence rate of winter SAD or S-SAD than summer SAD or S-SAD is consistent with most western studies and stands in contrasts to studies in other Asian countries, such as Japan and China.

• Ecology and Resilient Infrastructure
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• v.5 no.3
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• pp.125-133
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• 2018

Artificial neural network (ANN) is a powerful model to predict time series data and have been frequently adopted to predict groundwater level (GWL). Many researchers have also tried to improve the performance of ANN prediction for GWL in many ways. Dummies are usually used in ANN as input to reflect the seasonal effect on predicted results, which is necessary for improving the predicting performance of ANN. In this study, the effect of Dummy on the prediction performance was analyzed qualitatively and quantitatively using several graphical methods, correlation coefficient and performance index. It was observed that results predicted using dummies for ANN model indicated worse performance than those without dummies.

• Journal of the Korean Society of Hazard Mitigation
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• v.9 no.5
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• pp.103-113
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• 2009

In this study, we separated the precipitation zones using the geographic location of stations and precipitation characteristics (monthly, seasonal, annual) in Gangwon province. Precipitation data of 66 weather stations (meterological office: 11 locations, auto weather system (AWS): 55 places) were used, and statistical method, K-means cluster method, was conducted for division of the precipitation regions. As the results of regional classification, the five zones of precipitation (Yongdong: 1 region, Youngseo: 4 regions) were separated. Seasonal average precipitation in spring is similar throughout Gangwon Province, seasonal average precipitation in summer has high values at Youngseo, and seasonal average precipitation in autumn and winter have high values at Youngdong. The some areas, the vicinity of Misiryeong and Daegwallyeong, happens the orographic precipitation in spatial analysis, but the orographic effects didn't occur for the whole Gangwon areas. However, to achieve more accurate results, the expansion of observatories per elevation and AWS data are demanded.

• Journal of the Korean Association of Geographic Information Studies
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• v.19 no.1
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• pp.30-42
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• 2016

Climate change are known to have had enormous impacts on plant phenology and thus to have damage on other species which are interacted within ecosystem. In Korea, however, it is difficult to analyze the relationship between climate and phenology due to the limitation of measurement data of plant phenological records. In this study, to be effective analysis of SOG(start of growing season), we used phenological transition dates by using satellite data. Then, we identified the most influential variable in variation of SOG throughout the relationship between SOG and temperature factors. As a result, there is a strong correlation between the SOG and April temperature, TSOGmin($3^{\circ}C$, 12days). This study is expected to be used for predicting plant phenological change using climate change scenario data.

• Korean Journal of Ichthyology
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• v.23 no.3
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• pp.187-197
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• 2011

Fish species composition and size frequency distribution of major species were analyzed using seasonal samples collected by an otter trawl in the coastal water off Uljin and Hupo in 2002. Fish collected during the study were 20 species, 1,927 individuals and 53,969 g off Uljin, and 23 species, 2,762 individuals and 146,550 g off Hupo. Liparis tessellatus, Glyptocephalus stelleri and Cleisthenes pinetorum were predominated in abundance, and these 3 species were accounted for 70.9% in the number of individuals and 83.8% in biomass off Uljin, and 90.3% and 70.9% off Hupo, respectively. In the Korean coastal water of the East Sea, the migrating pelagic fish were predominated in catch by set net or gill net, and species composition varied greatly by season. Meanwhile, the fish collected by an otter trawl in the coastal water off Uljin and Hupo were dominated by the resident demersal fishes and did not show any clear seasonal trend in species composition. Collected G. stelleri and C. pinetorum were mainly composed of young fish, and size data as depth indicated that they moved into deeper shelf as they grew.