• 한국해안해양공학회:학술대회논문집
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• 한국해안해양공학회 2003년도 한국해안해양공학발표논문집
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• pp.344-352
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• 2003

Sediment plumes arising from various coastal works can cause detrimental effects on the coastal ecosystem in various manners. Although the most active countermeasure against the plumes is to restrict the works to specified time periods known as environmental windows (Reine et al., 1998), silt screens have been widely used for reducing the spreading of suspended sediments (SS) generated by coastal works. (omitted)

• 한국환경과학회지
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• 제19권6호
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• pp.703-714
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• 2010

In this study, we analyzed the impact of orographic and thermal forcing on the atmospheric flow field over the urban metropolitan areas on urban artificial buildings and future development plan. Several numerical experiments have been undertaken in order to clarify the impacts of the future development plan on urban area by analyzing practical urban ground conditions, we revealed that there were large differences in the meteorological differences in each case. The prognostic meteorological fields over complex areas of Seoul, Korea are generated by the PSU/NCAR mesoscale model(MM5). we carried out a comparative examination on the meteorological fields of topography and land-use that had building information and future development plan. A higher wind speed at daytimes tends to be forecasted when using new topography and land use data that have a high resolution with an appropriate limitation to the mixing height and the nocturnal boundary layer(NCB). During nighttime periods, since radiation cooling development is stronger after development plan, the decreased wind speed is often generated.

• The Plant Pathology Journal
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• 제38권1호
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• pp.46-51
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• 2022

Rice blast is the most destructive disease threatening stable rice production in rice-growing areas. Cultivation of disease-resistant rice cultivars is the most effective way to control rice blast disease. However, the rice blast resistance is easy to breakdown within years by blast fungus that continually changes to adapt to new cultivars. Therefore, it is important to continuously monitor the incidence of rice blast disease and race differentiation of rice blast fungus in fields. In 2020, a severe rice blast disease occurred nationwide in Korea. We evaluated the incidence of rice blast disease in Yeoju and compared the weather conditions at the periods of rice blast disease in 2019 and 2020. We investigated the races and avirulence genes of rice blast isolates in Yeoju to identify race diversity and genetic characteristics of the isolates. This study will provide empirical support for rice blast control and the breeding of blast-resistant rice cultivars.

• 대한교통학회지
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• 제17권4호
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• pp.47-58
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• 1999

현재까지 버스 스케줄은 일반적으로 순수배정문제 혹은 네트워크 유량문제의 형태로 하루의 모든 운행을 한꺼번에 처리하는 일괄처리 방식으로 작성되고 있다. 이 방법에 의할 경우 버스 스케줄링을 위한 계산량은 운행수(n)의 3승$(n^3)$에 비례하기 때문에 하루 동안의 운행회수가 많으면 문제의 크기가 커져 버스 스케줄을 구하는데 어려움이 발생한다. 만약 일정시간 동안 버스가 동일한 형태로 배차된다면 선입선출법(FIFO)과 같은 간단한 방법으로 해당 시간대에 대한 확장운행을 작성할 수 있기 때문에 스케줄링의 기본단위의 개수를 줄일 수 있고, 문제의 크기가 작아짐으로 인해 버스 스케줄을 쉽게 구할 수 있다. 본 논문에서는 시간대별로 동일한 배차형태를 갖는 버스운행형태에서 버스 스케줄링 문제의 크기를 줄이기 위해 하루 중에 운행시격 및 운행소요시간이 동일한 시간대를 분할하고, 분할된 시간대에 대한 시간대별 확장운행을 선입선출법으로 작성한 다음, 시간대별 확장운행을 기본단위로 하는 새로운 네트워크에서 하루 전체에 대한 버스 스케줄을 작성하는 시간분할에 의한 다시간대 버스 스케줄링 방법을 제시하였다.

• Journal of Nutrition and Health
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• 제16권4호
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• pp.243-252
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• 1983

This study was undertaken to invesigate the effect of early nutritional deprivation and environment on neurotransmitter concentrations and behavior in later life. The restoring process of rats fed foods ad libitum after 50% restriction of the casein or the Korean diet during the prenatal and/or the lactating periods was observed. There were two rearing conditions, isolated and enriched, after weaning. Behavioral development was measured by the Y- shaped water maze and the open field test. The neurotransmitters were analyzed after sacrifice at the age of 21 weeks. The results are summarized as follows. 1) The body weight impairment by dietary restriction during the prenatal and lactating periods could be restored within 18 weeks after weaning in case of living in a classical cage. The effect of quantitative restriction was bigger in the Korean diet than in the casein diet. 2) The brain weight was decreased by nutritional deprivation. Environmental enrichment increased it slightly. 3) The concentration of neurotransmitters, norepinephrine, dopamine, and serotonin, were not shown any traces of the dietary restriction at the age of 21 weeks. 4) In the maze test, the deprived rats made more errors than the nourished and the rats fed the Korean diet more than those fed the cascin dict. The environmental enrichment could decrease the number of errors. 5) In the open field test, the dietary deprived groups showed less reaction time, more squares entered in the field, and less number of fecal boli than the nourished among the environmentally isolated rats. However, rats living in the enriched cage without experience of nutritional stress showed the lowest emotionality and the elevated exploratory activity.

• 한국초등과학교육학회지:초등과학교육
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• 제36권2호
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• pp.113-128
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• 2017

This study aims to investigate the research trend of elementary environmental education. Thus, author keywords were extracted from a total of 197 academic these related to elementary environmental education during two different periods when detailed goals were applied to the 2007 and 2009 revised curriculums respectively, and then this study analyzed the network of author keywords. The results of this study can be summarized as below. Firstly, as a result of analyzing the frequency of author keywords from academic theses related to elementary environmental education, this study discovered 369 author keywords from the period when detailed goals were applied to 2009 revised curriculum. Out of them, it was found that the keyword, 'climate change education', showed the highest frequency, followed by 'environmental literacy' and 'environmental perception', except such central keywords as 'environmental education' and 'elementary school student'. From the period when detailed goals were applied to the 2007 revised curriculum, a total of 394 author keywords were discovered, and the keyword, 'environmental literacy', showed the highest frequency, followed by 'environmental perception' and 'ESD (education for sustainable development)'. Secondly, as a result of analyzing the network of author keywords, this study found out that in the total number of network connections, average connection degree, density and clique, the period when detailed goals were applied to the 2007 revised curriculum was somewhat higher than the period when detailed goals were applied to the 2009 revised curriculum. As a result of analyzing the centrality of author keywords, this study found out that during both the periods, 'environmental perception' and 'environmental literacy' were high in degree centrality and betweenness centrality, except such central keywords as 'environmental education' and 'elementary school student'. As a result of analyzing the components of author keywords as sub-networks, this study discovered 9 components from the period when detailed goals were applied to the 2009 revised curriculum and 6 components from the period when detailed goals were applied to the 2007 revised curriculum. During both the periods, the largest component was composed of keywords high in degree centrality and betweenness centrality.

• Fisheries and Aquatic Sciences
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• 제7권3호
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• pp.115-121
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• 2004

Experiments were carried out to investigate Cd accumulation, elimination and cell response in juvenile rockfish (Sebastes schlegeli) exposed to sub-chronic dietary Cd (0, 0.5, 5, 25 and 125 mg/kg) for 60 days and depuration periods of 30 days. Cd accumulation in the kidney of cock fish increased with exposure periods and concentrations for the 60 days of dietary Cd exposure. After the end of the dietary Cd exposure, Cd accumulation values in the kidney were $52.9{\pm}9.94\;{\mu}g/g$ and $90.6{\pm}15.7\;{\mu}g/g$ for those exposed to 25 mg/kg and 125 mg/kg Cd, respectively. The accumulation factors increased with the exposure period in the kidney. Cd elimination in the kidney of rockfish did not vary significantly and remained constant after the cessation of the dietary Cd exposure. In the primary exposure periods, the effect of kidney tissue in the rockfish exposed to dietary Cd was observed the swelling of capillary of the glomerulus. In addition, there was also hydropic swelling within the pyknotic nuclei, some of hyaline droplet accumulation and the microvilli showed a positive reaction to alcian blue in the tubular cells. While exposure time and concentrations were increased, there was a lot of hyaline droplet accumulation and the microvilli showed a positive reaction to alcian blue in the tubular cells. Fused renal tubule and its necrosis were observed after 60 days at l25 mg/kg.

• Earthquakes and Structures
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• 제11권5호
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• pp.779-807
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• 2016

Ground Motion Prediction Equations (GMPEs) are essential tools in seismic hazard analysis. With the introduction of probabilistic approaches for the estimation of seismic response of structures, also known as, performance based earthquake engineering framework; new tasks are defined for response spectrum such as the reference criterion for effective structure-specific selection of ground motions for nonlinear time history analysis. One of the recent efforts to introduce a high quality databank of ground motions besides the corresponding selection scheme based on the broadband spectral consistency is the development of SIMBAD (Selected Input Motions for displacement-Based Assessment and Design), which is designed to improve the reliability of spectral values at all natural periods by removing noise with modern proposed approaches. In this paper, a new global GMPE is proposed by using selected ground motions from SIMBAD to improve the reliability of computed spectral shape indicators. To determine regression coefficients, 204 pairs of horizontal components from 35 earthquakes with magnitude ranging from Mw 5 to Mw 7.1 and epicentral distances lower than 40 km selected from SIMBAD are used. The proposed equation is compared with similar models both qualitatively and quantitatively. After the verification of model by several goodness-of-fit measures, the epsilon values as the spectral shape indicator are computed and the validity of available prediction equations for correlation of the pairs of epsilon values is examined. General consistency between predictions by new model and others, especially, in short periods is confirmed, while, at longer periods, there are meaningful differences between normalized residuals and correlation coefficients between pairs of them estimated by new model and those are computed by other empirical equations. A simple collapse assessment example indicate possible improvement in the correlation between collapse capacity and spectral shape indicators (${\varepsilon}$) up to 20% by selection of a more applicable GMPE for calculation of ${\varepsilon}$.

• Journal of Preventive Medicine and Public Health
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• 제27권2호
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• pp.326-336
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• 1994

Due to rapid industrialization and economic development since 1970's, Seoul has become known as one of the most heavily polluted cities in the world. This is especially because of its air pollution. This study was conducted to characterize the cancer risk from organic pollutants in the suspended particulates of Seoul. Extractable organic matter (EOM) and PAHs in Shinchon, a major traffic area, were measured monthly in two periods of Aug. $1987{\sim}sep.$ 1988, and Sep. $1990{\sim}Aug.$ 1991. While the differences both of EOM and benzo(a)pyrene concentrations between these two periods were not significant (P>0.05), the differences between heating and non-heating seasons were significant (p<0.01). The estimated mean concentrations of EOM and benzo(a)pyrene in fine particles in non-heating season were $3.98{\mu}g/m^3\;and\;0.51ng/m^3$ respectively, and in heating season were $6.75{\mu}g/m^3\;and\;2.96ng/m^3$ respectively, in these two periods combined. The calculated risk from EOM was compared with that from benzo(a)pyrene and also these values were compared with the level of acceptable risk.

• 한국응용곤충학회지
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• 제25권1호
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• pp.11-16
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• 1986

이화명충(二化螟蟲) 발육(發育)의 지역적(地域的)인 차이(差異)를 조사(調査)하기 위해 전국(全國) 8 개(個) 지역(地域)에서 1984년(年) 11월(月) 하순(下旬)부터 12월(月) 하순(下旬)까지 월동중(越冬中)인 이화명충(二化螟蟲) 유충(幼蟲)을 채집(採集) 하여 1985년(年) 1월(月) 15일(日), 2월(月) 15일(日) 2차(次)에 걸쳐 가온사육(加溫飼育)하였다. 1. 용화전기간은 2차(次) 가온사육(加溫館育)에서 춘성산(春城産)이 17.9일(日)로 가장 빠르고 광산산(光山産)이 27.7일(日)로 늦었으며 1, 2차(次) 모두 위도(緯度)가 높은 지역(地域)에서 발육기간(發育期間)이 빠르고 위도(緯度)와 평균(平均) 용화전기간 사이에는 부(負)의 상관관계(相關關係)가 있었다. 2. 평균(平均) 용기간은 지역간(地域間) 큰 차(差)는 없었으며 우화(羽化)까지의 기간(期間)은 용화전기간과 같은 경향(傾向)이었다. 우화(羽化)는 위도(緯度)가 높은 지역(地域)에서 빨리, 낮은 지역(地域) 에서 늦게 되었다. 3. 우화양상(羽化樣相)은 춘성(春城), 평택산(平澤産)은 뚜렷한 peak 가 있었으나 논산(論山), 이리(裡里), 광산산(光山産)은 뚜렷한 peak가 었이 불규칙(不規則)하게 우화(羽化)하였다.