• 대한건축학회논문집:구조계
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• 제35권8호
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• pp.177-184
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• 2019

Recently, electric power usages and peak loads from buildings are increasing due to higher outdoor air temperatures and/or abnormal climate during the summer period. As one of the eco-friendly measures, a renewable energy system has been received much attention. Particularly, interest on a photovoltaic (PV) system using solar energy has been rapidly increasing in a building sector due to its broad applicability. In using the PV system, one of important factors is the PV efficiency. The normal PV efficiency is determined based on the STC(Standard Test Condition) and the NOCT(Nominal Operating Cell Temperature) performance test. However, the actual PV efficiency is affected by the temperature change at the module surface. Especially, higher module temperatures generally reduce the PV efficiency, and it leads to less power generation from the PV system. Therefore, the analysis of the relation between the module temperature and PV efficiency is required to evaluate the PV performance during the summer period. This study investigates existing algorithms for calculating module surface temperatures and analyzes resultant errors with the algorithms by comparing the measured module temperatures.

• Ocean and Polar Research
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• 제32권4호
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• pp.449-462
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• 2010

Ongoing port baseline surveys are essential for developing ballast water management procedures in order to control unwanted or potentially risky species. Seasonal distributional patterns of marine dinoflagellate Noctiluca scintillans internationally recognized as harmful species and the related environmental factors were surveyed at Incheon, Gwangyang and Ulsan seaports in Korea from 2007 to 2009. The above three seaports were chosen because of their status as the busiest in Korea and characterized by their different bioregions. Average temperature ranged from $2.08^{\circ}C$ in winter to $26.39^{\circ}C$ in summer at Incheon, $7.22^{\circ}C$ in winter to $25.77^{\circ}C$ in summer at Gwangyang, and $11.59^{\circ}C$ in winter to $21.67^{\circ}C$ in summer at Ulsan during the study period. Average salinity varied from 26.88 in winter to 31.25 in summer at Incheon, 22.83 in winter to 33.41 in summer at Gwangyang, and 30.04 in winter to 33.90 in summer at Ulsan. Noctiluca scintillans appeared consistently at all ports during the study period, indicating its eurythermal and euryhaline nature. The highest abundances (21,813 to 41,753 $inds{\cdot}m^{-3}$) of N. scintillans were observed in May 2008 and 2009 at the outer stations of Incheon port. Abundances of between 10,000 and 30,000 $inds{\cdot}m^{-3}$ were only observed at the innermost station of Ulsan in May, while abundances of between 10,000 and 40,000 $inds{\cdot}m^{-3}$ were frequently observed throughout all stations at Gwangyang during the study period, coinciding with consistently high concentration of chlorophyll-a (hereafter chl-a) ($4.32-8.24\;{\mu}g\;l^{-1}$) compared to other ports. Spatio-temporal variation of chl-a concentration was not significantly correlated with abundances of N. scintillans (p>0.01). However, relatively high chl-a concentrations were consistently recorded along with high abundances of N. scintillans throughout all stations at Gwangyang compared to other ports. Abundances of N. scintillans observed at the three surveyed ports did not significantly (p>0.01) affect the concentration of dissolved oxygen in the surface mixed layer, indicating that the species abundances were not enough to cause reduction of dissolved oxygen during the study period. Presented results indicated that the Gwangyang seaport may provide the most suitable environment for a wide range of N. scintillans blooming compared to other ports.

• 한국물환경학회지
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• 제37권6호
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• pp.458-468
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• 2021

In this study, we investigated the variations of dissolved organic matter (DOM) in an agricultural reservoir during the monsoon period (June to October, 2020) with respect to the organic carbon concentration (DOC), molecular weight distribution, and optical properties. The monsoon period was divided into three phases - beginning storm (BS), during storm (DS), and after storm (AS). Our results showed significant differences in the concentrations and characteristics of DOM during the summer monsoon. The DOC concentrations were decreased after the monsoon, probably due to a dilution effect. In contrast, increasing trends were observed in the specific UV absorbance (SUVA), and relative abundances of humic-like fluorescence and larger-sized compounds. These observations implied that the large-sized and humic-like organic components with terrestrial origins strongly affected the reservoir DOM after the summer monsoon. Meanwhile, biopolymer size fraction, which is associated with algal activity, became more abundant after the monsoon. These results suggest that DOM with autochthonous sources became dominant as a result of the inflow of nutrients into the reservoir after the storm. Spatial changes in DOM within the reservoir were not pronounced as much as the temporal variations. All taken, it can be concluded that the summer monsoon simply led to the decrease of DOM concentrations while the sources and the quality of DOM underwent substantial changes, which may enrich refractory organic matter in the reservoir. This study reveals the importance of in-depth DOM quality monitoring before and after summer monsoon for effective water quality management in agricultural reservoirs.

• 한국농공학회지
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• 제23권2호
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• pp.45-53
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• 1981

Long term precipitation gaging station record (58 years) was analyzed by progressive mean method to compare the estimated effective period of records for computing mean and probable values. Obtained results are as follows: 1. Fifty-eight years precipitation records at Jinju, Gyeong Sang Nam Do was analyzed by double mass analysis method. Result was appeared that the record was consistent with time. 2. The effective period of records for estimating mean values with the departure of 5% or less from the true mean are up to 33 years for annual precipitation, 20 years for annual maximum daily precipitation and 45 years for maximum successive dry days in summer season. 3. To estimate the probable values by Gumbel-Chow method within the departure of 5% level from true value, periods of 51 years, 38 years and 45 years were required for annual precipitation, annual maximum daily precipitation and maximum successive dry days in summer season, respectively.

• 한국발생생물학회지:발생과생식
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• 제25권3호
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• pp.145-155
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• 2021

Reproductive cycle of the blue-striped angelfish, Chaetodontoplus septentrionalis were histologically investigated. Fish were monthly collected in the coastal waters of Munseom, Seogwipo, Jeju-Island from February to December 2018. The gonadosomatic index (GSI) increased from May and maintained high values in August. The reproductive cycle of female fish can be classified by the characteristics observed during gonadal development as followed: growing stage (November to June), early mature stage (May to June), mature and spawning stage (June to September), and degenerative and recovery stage (September to December). In the male, testicular development period was similar to that of ovarian development period, but mature and spawning period was one month longer from June to October. Fecundity of mature female ranged from 4,601 to 22,840 and was correlated positively with total length and body weight. The histological analysis of gonadal development indicated that the C. septentrionalis was summer-spawning type and is considered a multiple spawner during spawning season.

• Asian-Australasian Journal of Animal Sciences
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• 제19권10호
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• pp.1415-1421
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• 2006

Proper nutritional management during the dry period is required to prevent metabolic disorders during the time of parturition and for potential increase milk yield during early lactation, especially under the heat of summer. The effect of prepartum diets on partitioning of nitrogen (N), calcium (Ca), phosphorus (P), magnesium (Mg) and potassium (K) during dry period and early lactation in summer was investigated. Nine cows were assigned to two groups and fed either control (group C: four cows) or high concentrate (group H: five cows) diets to meet 110% of their requirements before parturition. The proportion of concentrate in control diet was 35%, and that in the high concentrate diet was 45%. After parturition, all cows were fed the same diets ad libitum during lactation. Balance trials were conducted at 9, 8 and 7 days before parturition and at 12, 13 and 14 days after parturition. Before parturition, dry matter intake (DMI), DM and NFE digestibility in group C tended to be lower than those in group H. The retention of N (p<0.01) and P (p<0.05) in group C during the dry period was significantly lower than those in group H. The retention of Mg in group C during the dry period tended to be lower than in group H. The concentration of plasma NEFA in group C tended to be higher than in group H during dry period. The prepartum diet did not have an apparent effect on DMI and milk yield at 2 weeks after parturition and N, Ca, P, Mg and K balance after parturition.

• 대한지리학회지
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• 제39권6호
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• pp.819-832
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• 2004

본 연구에서는 한국의 14개 지점의 여름철 강수량을 분석하여 1941-1970년과 1971-2000년 기간 사이의 변동을 파악하고. 순별 강수량의 경년 변동과 해양변동 및 전구평균기온 변동과의 관련성을 파악하고자 하였다. 두 기간의 순별 강수량 차이에 의하여 중서부지역, 호남지역, 영동 및 영남지역. 제주도지역으로 구분하였다. 강수량은 8월에 증가하였고 9월에 감소하였다. 중서부지역에서 8월 강수량의 증가 폭이 크며, 이는 호우 빈도의 증가와 관련이 있다. 순별 강우량의 제 2극대기가 9월 초순에서 8월 하순으로 바뀌거나 출현하지 않는다. 점차 8월의 소우기가 사라지면서 장마가 9월 초순까지 이어지는 경향이다. 8월 중순과 9월 중순(혹은 7월 중순)의 강수량 편차는 1971년을 경계로 음에서 양 혹은 양에서 음으로 바뀌는 경향이며. 그 변동은 서서히 진행되고 있다. 대부분 지역에서 강수량 변동은 해양변동 및 전구평균기온과 높은 상관관계가 있다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2020년도 학술발표회
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• pp.169-169
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• 2020

According to the IPCC analysis, severe climate changes are projected to occur in Korea as the temperature is expected to rise by 3.2 ℃, the precipitation by 15.6% and the sea level by 27cm by 2050. It is predicted that the occurrence of abnormal climate phenomena - especially those such as increase of concentrated precipitation and extreme heat in the summer season and severe drought in the winter season - that have happened in Korea in the past 30 years (1981-2010) will continuously be intensified and accelerated. As a result, the impact on and vulnerability of the water management sector is expected to be exacerbated. This research aims to predict the climate change impacts on streamflow of Daecheong Lake area of Geum River in South Korea during the summer and winter seasons, which show extreme meteorological events, and ultimately develop an integrated policy model in response. We projected and compared the streamflow changes of Daecheong Lake area of Geum River in South Korea in the near future period (2020-2040) and the far future period (2041-2060) with the reference period (1991-2010) using the HEC-HMS model. The data from a global climate model HadGEM2-AO, which is the fully-coupled atmosphere-ocean version of the Hadley Centre Global Environment Model 2, and RCP scenarios (RCP4.5 and RCP8.5) were used as inputs for the HEC-HMS model to identify the river basins where cases of extreme flooding or drought are likely to occur in the near and far future. The projections were made for the summer season (July-September) and the winter season(November-January) in order to reflect the summer monsoon and the dry winter. The results are anticipated to be used by policy makers for preparation of adaptation plans to secure water resources in the nation.

• 한국대기환경학회지
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• 제13권3호
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• pp.179-191
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• 1997

The concentrations of organic and elemental carbon were determined using fine particle samples collected from Kosan, Cheju Island during the summer seasons of 1994 and 1995. The daily mean concentrations of organic and elemental carbon for each measurement period were 3.74 and 0.27 $\mu\textrm{g}$/㎥ in 1994, while those of 1995 were 2.36 and 0.10 $\mu\textrm{g}$/㎥, respectively The concentrations of organic carbon were higher than those commonly observed from clean areas around the world, but those of elemental carbon were lower than, or comparable to, other clean areas in the world. The resulting ratios of total carbon to elemental carbon at this site were thus higher than those seen from other metropolitan and non-polluted regions abroad. In addition according to our analysis, the 1994 measurement period can be classified into two periods: enhanced (July 20 and August 1) and reduced levels (August 2 and 9) of the carbonaceous species. The observed difference between two periods may be in part accounted for by the air trajectories representing each period. During the former period, the air masses from the Asian continent and Japan were dominant, while the air masses from the North Pacific Ocean came during the latter period. OC/EC ratios at the site were calculated to predict the possible formation of secondary organic aerosol . Based on our observations, we suggest that the formation of secondary organic aerosol might be an important pathway to the production of organic carbons.

• Environmental Engineering Research
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• 제17권3호
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• pp.175-176
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• 2012