When the radioactive nuclides are leaked from a deep geological repository by groundwater, the migration path of the nuclides is mostly consisted of rock fractures to the surface biosphere. Thus, assessing the safety of the disposed radioactive wastes depends upon understanding of nuclide migration in the fractured rocks. Fractures in rocks tend to dominate the hydrological characteristics of the dissolved nuclides. To study migration of nuclides in the rock fracture, a granite block of 1 m scale was quarried from the Hwangdeung site. The block has a single natural fracture. The six faces of the rock including fracture gaps were sealed with silicone adhesives to prevent leaking or diffusion of the water. Usually flow in fractured rock is unevenly distributed and most of the water flow occures over a small portion of the fracture zone, that is so called channeling flow. It is caused by uneven distribution of apertures in a fracture field. Flow rate is proportional to the cubic of the aperture. Thus, figuring out aperture distribution in a fracture field is the most important step on the study of the migration of nuclides in the fractured region. The ideal way to figure out the aperture distribution in a fractured rock is to use a non-destructive tool such as X-ray tomagraphe. However, it has a limitation of scale, that is, less than about 30 cm. It is not easy to give a good resolution for this quarried rock of 100×60×60 cm scale. It gives complex and vague images of the fracture. The optimum way to get an aperture distribution in a fractured rock is to drill some boreholes to the fracture and to carry out hydraulic tests. The more number of boreholes gives the more accurate information, but the more disturbance to the fracture field. Thus, it is necessary to optimize between aperture information and disturbing fracture field by selecting a suitable number of boreholes. We drilled nine boreholes from the upper surface of the rock mass just to the fracture without penetrating the fracture. And we carried out dipole tests for the matrix set of 9 boreholes. From each dipole test, an effective average aperture was calculated with the data of flow rate and hydraulic head. Then aperture distribution in the fracture field is calculated with a modified Krigging method. As a result, the aperture is distributed in the range of about 0.03~0.16 mm.

In this study, we evaluated fracture filling minerals and aperture distribution along the fracture surfaces under the controlled conditions. The fractured granite block which has a single natural fracture of 1 m scale was sampled in a domestic quarry (Iksan), which groundwater had been flowed through. This rock has an interconnected porosity of 0.36 with the specific gravity of 2.57. The experimental setup with the granite block with dimensions of 100×60×60 (cm). The fracture is sealed with rock silicone rubbers when it intersects the outer surfaces of the block and the outer surfaces are coated with the silicone to prevent loss of water by evaporation. Nine boreholes were drilled of orthogonal direction at the fracture surface. A flow of de-ionized water through the fracture between pairs of boreholes was initiated and the pressure required to maintain a steady flow was measured. In additions, fracture filling minerals were sampled and examined by mineralogical and chemical analyses. There are phyllosilicate minerals such as illite, kaolinite, and chlorite including calcite, which are fracture filling minerals. The illite and kaolinite usually coexist in the fracture, where their content ratio is different according to which mineral is predominant. For the evaluation of fracture, surface was divided into an imaginary matrix of 20×20 sub-squares as schematically. The calculated results are expressed as a two dimensional contour and a three dimensional surface plot for the aperture distribution in the fracture. The aperture value is distributed between 0.075 and 0.114 mm and the mean aperture value is 0.082 mm. The fracture volume is about 49 ml. These results will be very useful for the evaluation of environmental factor affecting the nuclides migration and retardation.

The nuclide management technology for separating high-heat generating/high-mobility/long-lived nuclides from high-level wastes based on the chemical reactions is under development. In order to secure the reliability of nuclear non-proliferation and to implement the effective safeguards, it is necessary to consider the safeguards from the conceptual design phase of the novel technologies. However, there was no experience and research on safeguards for the chemical reaction based nuclide management technology. In order to development the available monitoring techniques for the safeguards of nuclide management technology, the possible diversion scenarios were developed and the material flows of major nuclear materials were analyzed according to the various diversion strategies for each unit process in this study. The diversion strategies in this study is limited to the diversion of nuclear materials according to the change of operational parameters (temperature, chemical reagents, pressures, etc). The nuclear material distribution behaviors under the abnormal conditions were analyzed and compared with normal conditions using the HSC Chemistry. The results will be used to determine the proper signals and feasible techniques to monitor the abnormal operations.

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.

국내 침입외래종 미국가재(Procambarus clarkii)의 생물모니터링을 환경유전자 분석과 함께 2021년 2월부터 10월까 지 완주군, 함평군, 나주시, 구례군 청주시, 5지점에서 수행하였다. 조사방법은 우산형통발과 둥근뜰채를 이용하였으며, eDNA 분석을 위해 8~10 L의 물을 채수하였다. 조사지 내의 동소종인 저서성 대형무척추동물과 함께 과거 분포기록 및 국내 가재류 유통 현황도 분석하였다. 조사결과 미국가재는 총 122개체가 확인되었으며, 함평군에서 59개체 (48.36%)로 가장 많은 개체수와 높은 환경유전자(eDNA)가 검출되었고 계절상 5월달에 출현 빈도가 가장 높았다. 암컷과 수컷의 비율은 21:5로 암컷이 우세하였으며, 크기는 암컷이 72.2±21.1 mm, 수컷이 80.5±15.6 mm, 어린개체가 25.3±9.8 mm이었다. 국내에 유입된 미국가재는 남서쪽 지역을 중심으로 확산되고 있는 것으로 파악되었으며, 과거에 출현 기록이 있는 서울지역에서는 확인되지 않았다. 미국가재에 외부공생하는 끈거머리지렁이류는 확인되지 않았으며, 국내의 출현한 미국가재는 일본에서부터 수입된 개체로 추정되었다. 국내에서 유통되고 있는 외래 가재류는 8종 이상이 었으며, 이중 마블가재(Procambarus virginalis)는 2021년에 환경부에서 유입주의 생물로 지정된 종으로 파악되었다. 미국가재 조사지역 일대에 서식하는 저서성 대형무척추동물은 총 3문 5강 39과 69종이 출현하였으며, 잠자리목이 24.62%, 딱정벌레목과 노린재목이 각각 16.92%로 우세하게 나타났다. 이 중 한반도고유종 1종, 적색목록 범주의 준위협(NT)으로 구분되는 1종, 갑각류는 총 6종이 출현하였다. 섭식기능군에서는 잡아먹는무리가 서식기능군에서는 기어오르는무리가 전체적으로 우세하여 출현하였다. 조사지역 내의 미국가재는 수초와 수변부 식생이 풍부한 지역을 선호하며, 수질이 탁한 곳에서도 내성이 강한 것으로 분석되었다. 잡식성인 미국가재는 동소종에서 우세하게 출현하는 육식성 저서생물과 상호 경쟁관계를 유지할 것으로 보이며, 먹이사슬에 따른 생태계 교란이 지속적으로 일어날 것으로 판단된다.

The distributions of common minke whales observed in the East Sea in ten surveys in May of 2003, 2005, 2006, 2007, 2009, 2010, 2012, 2015, 2016 and 2020 were investigated using satellite sea surface temperature (SST) derived from the Moderate Resolution Imaging Spectrometer (MODIS). Most of the minke whales were observed in the waters off the Korean Peninsula at 36-38.5° N, which is expected as the highly productive coastal upwelling area. Yet, no minke whale was observed in 2006 when a relatively larger scale coastal upwelling occurred with SST at 11°C. In 2016 and 2020, the warm water higher than 17°C extended widely in the area, and the minke whales were observed in the offshore waters, deeper than 1,000 m. 87.5% of minke whales observed in May appeared in the SST from 13 to 16°C, and they seemed to avoid relatively high temperatures. This suggests that optimum habitat water temperature of minke whales in May is 13-16°C. The SST in the area had risen 1.67°C from 2003 to 2021, and it was remarkably higher than in other parts of the surrounding areas. The future temperature rising may change the route and timing of the migration of minke whales in the study area.

제4차 산업혁명은 세계의 산업정책을 변화시키고 있다. 전통적인 제조업 중심의 하드웨어 경제에서 소프트파워 중심의 산업으로 전환되고 있다. 우리나라도 이런 변화에 대응하기 위해 신산업육성을 위한 정책을 추진하고 있다. 이 연구의 목적은 시대별 산업단지 조성정책에 따른 우리나라 산업단지의 공간분포를 고찰하는데 있다. 그 결과, 우리나라 산업단지의 입지는 시대별 산업 개발 정책의 영향을 많이 받았다. 1960년대의 수출산업육성을 위한 경공업 중심 정책으로 내륙의 산업단지 개발이 이루어졌으 며, 1970년대에는 중화학 공업을 중점 육성하기 위해서 임해형 산업단지가 주로 조성되었다. 거점개발방식에 의한 대규모 산업단지 조성으로 지역 간 불균형 문제 해소에 집중하였고, 이촌향도 현상을 해소하기 위해 지방산업단지 개발과 농공단지를 확대하는 정책을 추진하였다. 1990년대부터는 첨단산업육성을 위해 전문산업단지와 첨단과학단지 등이 시대의 산업단지 조성정책에 맞춰 개발되었다. 최근 노후화된 산업단지 수가 급증하면서 산업단지 재생 및 산업단지 대개조 사업을 통한 노후 환경 개선 및 업종 전환을 통해 도시 내 산업단지로 전환되고 있으며, 미래 기술 개발과 제조업 혁신 준비를 위한 캠퍼스혁신파크 조성 등 기술우위를 선점하기 위한 준비를 추진하고 있다. 따라서 산업단지 조성정책과 공간분포에 대한 지속적 모니터링을 통해서 거시적 흐름을 파악하고 미래를 대비하는 연구가 계속되어야 한다.

본 연구는 구리화합물계 목재방부제로 가압방부처리된 난주입수종이 국내 지상부 목재사용환경에서 방부성능을 유지할 수 있는 조건을 파악하기 위하여 수행되었다. 장기간(12년)의 지상부 야외노출시험을 통하여 방부성능이 입증된 방부처리 목재를 대상으로 목재 내부에 존재하는 주요 방부성 분인 구리의 분포 상태를 조사하였다. 구리 정색반응 결과를 살펴보면 변재는 대부분 균일하게 처리되었지만, 심재에서 구리의 침투는 목재 표면에 국한되어 있는 것으로 나타났다. 심재에서 구리의 침투는 국내 방부목 표준규격에서 요구하는 심재의 최소 침윤깊이(8 mm)를 만족하지 못하였다. 그러나 기준을 만족하지 못한 방부처리 시편들도 우수한 방부효능을 가지고 있다는 것을 알 수 있는데 이러한 결과는 난주입수종의 적절한 활용을 위해 국내 규격의 보완이 필요하다는 것을 의미한다.