This study was conducted to identify the distribution characteristics of the impervious area in urban watersheds and to reduce the deviation of the impervious area ratio that occurs depending on the degree of construction of land surface condition data. The average impervious area ratio by land use that can be applied to the calculation of the urban impervious area ratio was derived by statistically analyzing the distribution characteristics of the impervious area ratio by land use according to the urban watershed conditions. In urban watersheds, the change in impervious area ratio over the past 20 years has continuously increased in watersheds with an impervious area ratio of less than 60%, and decreased in watersheds with a high impervious area ratio of 60% or more. The average impervious area ratio by land use applicable to the land use technique is “Residential area” 84.0%, “Residential and commercial mix” 93.6%, “Commercial and business facilities” 89.8%, “Industrial land” 84.8%, “Public land” 47.3%, “Transportation facility” 93.3%, “Urban revitalization facility” 61.1%, “Bare land” 17.6%, “Special area” 11.4%, “Forest and open space” 3.5%, “Rivers and lakes” 9.2%. As a result of examining the adequacy of the average impervious area ratio by land use, the difference between the calculated value of the impervious area ratio using land use techniques and the actual impervious area ratio of the biotope map ranged from -3.0%p to 2.6%p at the significance level of 95%. In addition, when the watershed condition is applied, the difference ranged from -2.3%p to 1.7%p. By applying the average impervious area ratio by land use derived in this study, it was found that the impervious area ratio of the target urban watershed could be calculated within a deviation of ±3%p.
The community temperature index (CTI) reflects the temperature and environmental preferences of the community. We investigated the distribution patterns of major aquatic insect assemblages (Ephemeroptera, Plecoptera, and Trichoptera; EPT) based on CTI in streams of South Korea. We selected unpolluted 151 study sites at upper streams (less than 3rd) with less than 1.5 mg L-1 of biochemical oxygen demand. Study sites were clustered into six groups based on the similarities of their EPT composition. All three orders showed a continuous decrease in the number of species as CTI increased, especially in Plecoptera. In addition, the functional feeding groups were also significantly changed according the CTI changes. Temperature tolerance range of each group’s indicator species varied according to the CTI of the group. Finally, changes of CTI reflected differences of EPT assemblages according to the differences of environmental condition including temperature. Therefore, CTI can be applied to the evaluation and preservation of stream ecosystems and prediction of community changes due to climate change.
본 연구는 남부 산림지역 고등균류의 임상별 분포 특성 및 다양성을 구명하기 위해 수행되었다. 경상도와 전라도 일대에 임상별 8개씩 총 24개의 고정조사구에서 고등균류를 채집한 결과, 868점의 표본을 채집하였으며, 2문, 6강, 17목, 61과, 134속, 367종으로 동정되었다. 부생성 균류가 62.44%로 가장 높은 비율을 보였으며, 다음으로는 공생성 균류 35.03% 기생성 균류 2.53% 순으로 조사되었고, 우점종은 구름송편버섯 (Trametes versicolor)과 맑은애주름버섯(Mycena pura)으로 확인되었다. 해발고도에 따른 고등균류의 분포는 299m 이하의 조사구에서 74종, 300∼499m에서 299종, 500m 이상에서 153종이 조사되었으며, 채집 시기별 고등균류의 분포는 7, 8월에 각각 190, 152종으로 가장 많이 조사되었 다. 임상별로는 활엽수림에서 192종으로 가장 많이 조사되었고, 혼효림 177종, 침엽수림이 149종으로 조사되었고, 지역별, 고도별, 시기별, 임상별 모두 부생성 균류가 가장 높은 비율로 분포하였다. 종다양도는 300∼499m의 활엽수림에서 7월에 2.2로 가장 높았고, 종 균등도는 고도별, 시기별, 임상별로 비슷한 수준을 나타냈다(0.93-0.97). 본 연구를 통해 얻어진 남부 산림지역 내 고등균류 분포 특성 및 다양성 결과들은 향후 수행될 고등균류 분야 연구의 기초자료로 활용될 것으로 기대된다.
흰꽃세덤(Sedum album)은 포복성으로 자라며 무리 지어 개화하는 특성을 가진 다육식물의 일종이다. 흰꽃세덤은 의약 품에 사용될 수 있는 플라보놀 배당체(flavonol glycoside)를 많이 생산하는 것으로 알려져 있다. 뿐만 비생물적 스트레 스 요인에 대해 강한 저항성을 가지고 있고 옥상녹화 시스템 (green roof systems)에 많이 사용되는 식물이다. 흰꽃세덤 은 강인한 생명력과 특이한 외형을 기반으로 실내에서 관상식 물로 사용될 수 있는 잠재력도 가지고 있다. 그러나 흰꽃세덤 이 실내식물로써 활용되기 위해서는 생장에 적합한 광질이 구명되어야 한다. 이에 따라 본 실험에서는 인공광원으로 시중 에 상용으로 판매되고 있는 3000, 4100, 6500K 백색 T5 LED를 사용하였으며 식물은 흰꽃세덤의 우량종인 ‘아툼’(S. album cv. Athoum)을 선발하여 본 실험에 적용하였다. 결과 적으로 초장, 초폭, 피복면적, 근장, 분지의 개수와 같은 식물 의 크기를 나타내는 지표는 4100K 백색 LED 처리구에서 크 게 증가하는 것으로 나타났다. 식물의 생체중과 수분함량은 4100K 백색 LED에서 증가하였으나 건물중은 3000K 백색 LED에서 증가하는 것으로 나타났다. CIELAB 중 명도를 나타 내는 L*은 4100K 백색 LED에서 가장 높게 나타났는데 이는 식물의 높은 수분함량으로 인한 세포의 팽창 혹은 에피큐티큘 러 왁스층(epicuticular waxes)의 발달로 추측되었다. CIE76 color difference(ΔE * ab)는 4100K 백색 LED 처리 구와 6500K 백색 LED 처리구 간에 ΔE* ab=5.51로 가장 크게 나타났다. RHS 분석에서는 모든 처리구가 동일하게 N137A, 147A로 평가되었다. 결론적으로 식물을 판매하거나 관상가치 를 향상시킬 목적으로 식물의 크기를 유의미하게 증대시키고 자 하는 경우 4100K 백색 LED를 사용할 것을 권고한다. 한 편, 살아있는 식물체를 약용으로 사용하거나 2차 대사산물을 추출하고자 하는 경우 4100K 백색 LED의 사용을 권고하며 말린 식물체를 활용하고자 한다면 3000K 백색 LED를 사용 할 것을 권고한다.
Mushrooms in Naejangsan National Park between May and September of 2021 have been surveyed. In this period, a total of 4 divisions, 9 classes, 25 orders, 72 families, 171 genera, and 381 species, including 3 climate-sensitive biological indicator species were found. The order in which the most diverse array of species was observed is Agaricales, which includes 24 families, 64 genera, and 170 species. Among these, the genus Russula was dominant, with 30 species, followed by the genus Amanita with 27 species. Among the 12 grids we investigated, species diversity was greatest in grid F5, in which 56 species of mushrooms were found. In particular, a large number of ectomycorrhizal mushrooms, including Russula spp. and Lactarius spp. were recognized. We presume that the gentle slopes and the low occurrence of Sasa borealis in this area may create a favorable environment for wild mushrooms. In corroboration, some grids (e.g. F6, F8, and F10) covering steep slopes and harboring large numbers of Sasa borealis contained only 19 species. Based on DNA sequence analysis, the NJ21064 was identified as Chlorophyllum hortense, which is newly recorded in Korea.
This paper introduces a container loading problem and proposes a theoretical approach that efficiently solves it. The problem is to determine a proper weight of products loaded on a container that is delivered by third party logistics (3PL) providers. When the company pre-loads products into a container, typically one or two days in advance of its delivery date, various truck weights of 3PL providers and unpredictability of the randomness make it difficult for the company to meet the total weight regulation. Such a randomness is mainly due to physical difference of trucks, fuel level, and personalized equipment/belongings, etc. This paper provides a theoretical methodology that uses historical shipping data to deal with the randomness. The problem is formulated as a stochastic optimization where the truck randomness is reflected by a theoretical distribution. The data analytics solution of the problem is derived, which can be easily applied in practice. Experiments using practical data reveal that the suggested approach results in a significant cost reduction, compared to a simple average heuristic method. This study provides new aspects of the container loading problem and the efficient solving approach, which can be widely applied in diverse industries using 3PL providers.
In this study, we used underwater acoustics to analyze the spatial and temporal distribution characteristics of largehead hairtail (Trichiurus leptueus) based on the luminous thronging of metal halide fishing lamps and induction fishing lamps. As a result, the illuminating power was approximately 1.3 times higher using the metal halide fishing lamp whereas the density of hairtals by distance was approximately 1.9 times higher using the induction fishing lamp. Regarding water depth distribution, hairtails were detected depths of 25-30 m during August and at all water depths in November as assessed using fishing lamps.
To provide information needed for managing fish resources and protecting the ecosystem of Cheonsu Bay, bimonthly variations in species composition and abundance of fish eggs and larvae were investigated. The samples were collected by using bongo net at three different stations from February 2020 to December 2021. Fish eggs were divided into Engrualis japonicus and unidentified eggs, of which Engragulis japonicus accounted for 85.6% of the total eggs collected. A total of 21 species representing 17 families and 6 orders were collected. The three dominant species were Gobiidae spp, Thryssa hamiltonii and E. japonicus and these three species accounted for 74.1% in the total number of individuals. The number of species was highest in August, 2020 and lowest in February, 2020 and 2021; the number of individuals was highest in August, 2020 and lowest in February, 2020. Temporal changes in the abundances of pelagic eggs and larval fishes corresponded with temperature.
The Alkali-Metal Thermal to Electric Converter (AMTEC) can be used as a next-generation power generation technology related with a large thermal energy storage. In particular, this technology is expected for the higher efficiency by a cascade power generation with the thermoelectric generator(TEG), and the temperature distribution becomes a very important design parameter in this case. In this study, the temperature distribution of the AMTEC unit was analyzed through CFD analysis, and design points were discussed based on the results.
본 연구는 남해안 38개 특정도서의 암반조간대에서 2019년 8월부터 10월까지 방형구(50x50cm)를 이용하여 대형저서동물의 공간 분포와 우점종 조사를 실시하였다. 특정도서에서는 총 80종이 출현하였으며, 연체동물이 54종으로 67.4%를 차지하여 가장 우점하였고, 절 지동물은 15종(18.7%)이었다. 그 외 자포동물, 해면동물, 극피동물은 1~6종의 범위내에서 출현하였다. 지역별로 보면, 여수의 특정도서에서 61종으로 가장 많았으며, 하동, 남해, 추자도 등에서는 각각 42~46종으로 유사하였고, 보성과 고흥은 29종으로 출현종수가 가장 적었다. 정 점별 출현종수는 6종(정점 6)~33종(정점 20)의 범위로 큰 차이를 보였다. 주요 우점종은 좁쌀무늬총알고둥으로 15개 특정도서에서 우점하 였으며, 그 다음으로 검은큰따개비가 11개 특정도서에서 우점종으로 출현하였다. 좁쌀무늬총알고둥은 36개 특정도서에서 출현하여 가장 넓게 분포하였으며, 대수리 30개, 굵은줄격판담치 29개, 갈고둥 28개, 갯강구 27개, 총알고둥 26개의 특정도서에서 출현하였다. 국외반출승 인 대상종은 연체동물 9종, 절지동물 4종, 자포동물 2종이며, 국가적색목록은 총 50종으로 관심대상(LC)은 44종, 정보부족(DD) 3종, 미평가 (NE), 준위협(NT) 및 미적용(NA)은 각각 1종씩 출현하였다. 남해안 특정도서에서 출현한 대형저서동물은 지역에 따른 노출시간, 암간 조간 대의 길이, 암반기질 등 서식환경 차이에 의한 출현종수와 우점종의 차이를 보였다. 본 연구 결과는 추후 특정도서 모니터링과 관리방안 수립시 기초자료로 활용될 수 있을 것으로 생각된다.
오대산국립공원 내 뱀류 로드킬의 발생 경향 파악 및 예방을 위하여 2006-2017년 사이 공원 내에서 발생한 뱀류 로드킬 자료를 확보 및 분석하였고, 잠재적 발생지 예측을 위하여 종분포모델을 제작하였다. 연구기간 동안 뱀류 로드킬 은 600m 대의 양쪽 환경이 산림-수계인 도로에서 가장 많이 발생하였다. 모델링 결과에서 뱀류 로드킬 발생 가능성은 고도 700m 이하의 하천과의 거리가 25m 부근인 완만한 경사의 도로의 로드킬 발생확률이 높게 나타났다. 국립공원 내 주요 로드킬발생 예측지역은 국도 6호선 도로 위 공원 남쪽 경계로부터 약 2.2㎞ 지역과 약 11.7㎞ 지역이, 지방도 446호선 도로 위 공원 남쪽 경계로부터 약 3.44㎞ 지역이었다. 본 연구결과는 해발고도 700m 이하 수계와 인접한 도로 주변에 우선적으로 대체 일광욕 장소, 생태통로 및 도로의 유입을 막는 울타리의 설치가 산림에서 뱀류 로드킬을 줄이는 효과적인 방안이 될 것을 제시한다.
Black carbon (BC), which is mainly contained in fine particulate matters, is one of the typical anthropogenic air pollutants that are generated from the incomplete combustion process and discharged into the atmosphere, and its various health effects particularly on children have been a growing concern. In this study, BC and particulate matters were closely analyzed in an elementary school adjacent to a high- traffic road in a large metropolitan city. The investigation showed that black carbon behaved similarly to ultrafine dust of 0.3 μm or less in the air, accounting for 20%-40% of it. The occurrence of high concentration outdoor pollution influences the BC content in indoor particulate matters. The average I/O value was 0.7 during the class-hours, and 0.8 without students. However, when students played in the classroom, the range of BC concentrations varied from 0.25 to 1.15, wider than 0.41-1.13 without students. Although this study was conducted with regard to just one elementary school, it can be considered to represent the typical air quality status of domestic schools, and it is believed to present valuable data which can be utilized to assist with preparing measures to enhance the air quality management of schools.
This paper analyses various types of unethical expressions and distribution features in both large-scale broadcasting corpus and messenger corpus. The use of these unethical expressions appear to vary considerably depending on the register. As such, annotations for de-identification should be based on a register-specific approach rather than a general one. The results of the study can be summarized as follows. First, unethical expressions are categorized into four types: 'swearing expressions, hate speech, aggressive expressions, and sexual expressions.' Second, the quantitative analysis shows that the amount of unethical expressions in messenger is much higher than in broadcasting. Third, the proportion of [+person] expressions is very high in broadcast conversations, while swearing expressions account for more than 90% of the unethical expressions in the messenger corpus. Our study suggests that register variation, contextual information and language categories beyond word unit need to be reconsidered to detect unethical expressions.
국내에서는 ‘태양광 발전 사업‘을 지원하여 태양광 발전소를 늘려나가고 있다. 태양광 발전기는 옥외에 있어 바람에 직접적 으로 노출되어있기 때문에 태풍과 같은 강풍에 큰 영향을 받게 된다. 최근 태풍의 강도와 빈도가 증가하면서 이에 따른 피해가 증가하 고 있다. 태양광 발전기는 유지 관리 및 보수 작업의 용이성 때문에 동서방향으로 배치한 태양광 어레이들 좌우 사이에 이격거리를 두 고 설치된다. 따라서 본 연구에서는 동서방향 이격거리를 변수로 특정하여 태양광 어레이에 작용하는 풍압분포와 피크순압력계수를 산출하였다. 이를 위해 이격거리를 0.3m, 0.5m, 1.0m로 선정하여 풍압실험을 진행하였다. 모든 변수에서 어레이의 양측 상부 모서리에 서는 상방향, 하부 모서리에서는 하방향의 피크순압력계수가 지배적이었다. 어레이 내단부에서는 상방향과 하방향의 피크순압력계수 가 이격거리 0.3m일 때 가장 크게 나왔으나, 외단부보다 전체적으로는 값이 작았다. 어레이 좌우 이격거리에 대한 내단부에서의 수속 효과보다 외단부에서 생긴 와로 인한 피크순압력계수가 크게 나타났기 때문에 외단부에 대한 안전성을 더 고려해야 할 것으로 판단된다.
Markov envelope as a theoretical solution of the parabolic wave equation with Markov approximation for the von Kármán type random medium is studied and approximated with the convolution of two probability density functions (pdf) of normal and gamma distributions considering the previous studies on the applications of Radiative Transfer Theory (RTT) and the analysis results of earthquake records. Through the approximation with gamma pdf, the constant shape parameter of 2 was determined regardless of the source distance ro. This finding means that the scattering process has the property of an inhomogeneous single-scattering Poisson process, unlike the previous studies, which resulted in a homogeneous multiple-scattering Poisson process. Approximated Markov envelope can be treated as the normalized mean square (MS) envelope for ground acceleration because of the flat source Fourier spectrum. Based on such characteristics, the path duration is estimated from the approximated MS envelope and compared to the empirical formula derived by Boore and Thompson. The results clearly show that the path duration increases proportionately to ro 1/2-ro 2, and the peak value of the RMS envelope is attenuated by exp (-0.0033ro), excluding the geometrical attenuation. The attenuation slope for ro≤100 km is quite similar to that of effective attenuation for shallow crustal earthquakes, and it may be difficult to distinguish the contribution of intrinsic attenuation from effective attenuation. Slowly varying dispersive delay, also called the medium effect, represented by regular pdf, governs the path duration for the source distance shorter than 100 km. Moreover, the diffraction term, also called the distance effect because of scattering, fully controls the path duration beyond the source distance of 300 km and has a steep gradient compared to the medium effect. Source distance 100-300 km is a transition range of the path duration governing effect from random medium to distance. This means that the scattering may not be the prime cause of peak attenuation and envelope broadening for the source distance of less than 200 km. Furthermore, it is also shown that normal distribution is appropriate for the probability distribution of phase difference, as asserted in the previous studies.