• Korean Journal of Fisheries and Aquatic Sciences
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• v.24 no.4
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• pp.229-236
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• 1991

A study on the estimation of the stock density and biomass of Perinereis aibuhitensis in the tidal zone in Sosan, Chungchongnam-do, Korea was carried out from June to July 1988. A preliminary survey was conducted to determine the distribution pattern of the species and the optimum sample size for setting up the sampling design. The stock densities of the species by stratum and by subarea were estimated using the stratified random sampling method, based upon the results of preliminary survey. The differences in density between strata as well as among subareas were tested to decide whether they can be combined together for estimating the overall stock biomass or not. The results of the survey showed that p. aibuhitensis were randomly distributed(Poisson distribution) and the number of quadrats which satisfies a reasonable level of precision was determined to be five by stratum. The densities between strata were not significantly different, while densities among subareas were different. Subarea C showed the highest density with the mean of $53.9g/m^2$ and followed by subarea B. The density of subarea A was the lowest with the mean of $18.2g/m^2$. The overall mean density from the study area was $32.4g/m^2$ with the coefficient of variance(CV) of $6.8\%$ The overall stock biomass was estimated to be 147.5mt in this area.

• Journal of Environmental Science International
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• v.19 no.2
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• pp.197-207
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• 2010

This study was carried out to investigate the ecological characteristic of native Parasenecio firmus population in Korea and China. The survey quadrates were located in the middle of the native P. firmus habitats. According to the field survey, the habitats of P. firmus were classified into same Tilia amurensis community in tree layer. The investigation of native habitat in Korea shows that P. firmus inhabited deciduous forest from with T. amurensis, Acer pictum subsp. mono, Carpinus cordata and Acer pseudosieboldianum, which was similar to vegetation structure of Mt. Laoling in China. The result of the cluster analysis which uses SYN-TAX 2000 program, dissimilarity from 53% level was on a large scale divided at 2 units. The research revealed 96 taxa in total, in which 51 families, 81 genera, 21 varieties, 5 forma, 1 sub-species and 67 species were checked in the flora of the native P. firmus habitats.

• Journal of Korean society of Dental Hygiene
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• v.6 no.4
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• pp.361-374
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• 2006

The purpose of this study was to obtain basic data for development of oral health educational program on the control of handicapped children at social welfare facilities. For this research, it was investigated by a survey on the actual condition of dental health of handicapped children, and simultaneously by analyzing the relationships between the realities of child's dental condition and parents and guardian's acknowledgments and managements with regard to the dental health of children. This survey was conducted 135 children and their guardians being 4 social welfare facilities in Ulsan metropolitan city. 1. The average of DT, MT, FT and DMFT index were 1.82, 0.01, 0.98 and 2.84 respectively. 2. Rolling Toothbrushing method was the highest response(58.5%) and 3 times per a day(77.0%). A proxy of toothbrushing was parents(39.2%) and teacher(60.8%). 3. Recognition routes of toothbrushing method were family(13.3%), school(43.7%) and dental chinic(42.2%). 4. The numer of times electromotion tooth brushing was the highest response in more than 4 times per a day. Toothbrushing after eating between meals was higher negative response(50.4%). The number of times visiting dental clinic was the highest response in more than 5 times during a year(51.9%).

• Proceedings of the Plant Resources Society of Korea Conference
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• 2020.08a
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• pp.35-35
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• 2020

본 연구는 한남정맥의 최 북서쪽에 위치한 경기도 김포시의 문수산(376m) 일원을 중심으로 식물상을 조사하였다. 본 연구에서 확인된 관속식물은 97과, 241속, 340종, 41변종, 6아종, 2품종 등 총 389분류군으로 조사되었다. 특산식물은 병꽃나무, 복사앵도 및 산이스라지 등 6분류군이 확인되었고, 식물구계학적 특정식물은 I등급은 부싯깃고사리, 비목나무, 삿갓사초, 소사나무 등 15분류군, II등급은 꼬리조팝나무, 돌단풍, 피나무, 오리나무 등 6분류군, III등급은 좀작살나무, 좀개미취, 산벚나무, 병아리꽃나무 등 5분류군, IV등급은 복상앵도, 산복사 등 3분류으로 확인되었다. 환경부에서 지정한 외래종 및 생태계교란 야생식물은 가시박, 단풍잎돼지풀, 도깨비가지, 미국쑥부쟁이, 애기수영, 털물참새피 등 53분류분이 확인되었다. 하지만 선행연구에서 조사되었던 멸종위기종 II급인 매화마름과 산림청지정 희귀식물 위기종 깽깽이풀 2분류군이 조사되지 않아 추후 추가 조사 및 유전자원 현지내외 보전대책을 수립해야 할 것이다.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• v.5 no.2
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• pp.55-59
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• 2024

The remarkable economic growth achieved in the modern era has revitalized various industries, including pet trade. More than 2,000 species of non-native species have been introduced to South Korea and approximately 7.7 tonnes of alien turtles are imported annually. Turtles belonging to the family Kinosternidae. They are mostly small and popular pets, although they are designated as Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) species. In the present study, we present the first two species of musk turtles found in the wild in South Korea. On April 5, 2023 and July 8, 2023, an eastern musk turtle (Sternotherus odoratus) and a razorbacked musk turtle (Sternotherus carinatus) were captured in Ilsandong-gu, Goyang-si, Gyeonggi-do and Jung-gu, Daejeon, respectively. The carapace length was 88.6 mm for S. odoratus and 105.68 mm for S. carinatus. They were identified based on their morphological characteristics and mtDNA cytochrome b gene. These turtles were found in waterfront areas with over 1.4 million annual visitors. Both sites were found to have threatened amphibians and reptiles. There is an urgent need to continue monitoring and conducting risk assessments for the protection of endemic species in Korea.

• Journal of the Korean earth science society
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• v.28 no.1
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• pp.64-74
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• 2007

The marine seismic prospecting using a research vessel in the shallow sea near the coastal area has certain limits according to the water depth and survey environment. Also, for the electrical resistivity survey at seashore area, one may need a specially designed high-voltage source to penetrate the very conductive surface layer. Therefore, we have conducted a feasibility study on the application of magnetotelluric method (MT), a passive geophysical method, on investigating of shallow marine environment geology. Our study involves both theoretical modeling and field survey at the tidal flat area which represent the very shallow marine environment. We have applied the audio-frequency magnetotelluric (AMT) method to the intertidal deposits of Gunhung Bay, west coast of Korea, and analysed the field data both qualitatively and quantitatively to investigate the morphology and sedimentary stratigraphy of the tidal flat. The inversion of AMT data well reveals the upper sedimentary layer of Holocene intertidal sediments having a range of 13-20 m thickness and the erosional patterns at the unconformable contact boundary. However, the AMT inversion results tend to overestimate the depth of basement (30-50 m) when compared with the seismic section (27-33 m). Since MT responses are not significantly sensitive to the resistivity of middle layer or the depth of basement, the AMT inversion result for basement may have to be adjusted using the comparison with other geophysical information like seismic section or logging data if possible. But, the AMT method can be an effective alternative choice for investigating the seashore area to get important basic informations such as the depositional environment of the tidal flat, sea-water intrusion and the basement structure near the sea shore.

• Korean Journal of Soil Science and Fertilizer
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• v.38 no.3
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• pp.119-126
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• 2005

Soil erosion at Jawoon-Ri in Hongcheon highland is one of serious problems since saprolite piling on farmland has been typically practiced at 2-3 year's intervals. The objective of the case study was to survey management practices such as tillage, application of saprolite, and cultivating crops and to propose best management practices (BMP) to reduce soil loss in Jawoon-Ri, Hongcheon-Gun. Jawoon-Ri is located in the upper stream of Naerinchun. Upland areas of Jawoon 2 and 4Ri were 206.9 and 142.3 hectare, respectively. Estimation of soil loss in this study was based on USLE (Universal soil loss equation). Annual averaged soil losses were 15.6 MT per hectare in Jawoon-2Ri and 9.0 MT per hectare in Jawoon-4Ri, respectively. This case study tried to find methods to reduce soil erosion below tolerant soil loss level which is $11MT\;ha^{-1}\;yr^{-1}$. Estimated soil losses in more than 40% of uplands in Jawoon-2Ri and 4Ri were higher than tolerant soil loss level. Especially, edge of uplands undergone excessive soil erosion by concentrated runoff water. Therefore consolidation of upland edge was included as one of the proposed Best management practices BMP). The proposed BMP in this area were buffer strips, contour and mulching, diversion drain channel, grassed water-way, detour watet-way and cover crops and so on. Amounts for BMP requirements were 7,680 m for buffer strips, 123 ha (35%) for contour and mulching, 201 ha (57%) for diversion drain channel, 13,880 m for grassed water-way, 3,860 m for detour drainage, 8,365 m for sloping side consolidation and 3,492 ha for cover crops, respectively. Application of BMP are urgently needed in uplands which is direct conjunction with stream.

• Korean Journal of Soil Science and Fertilizer
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• v.37 no.4
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• pp.199-206
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• 2004

Factors of universal soil loss equation, USLE, and its revised version, RUSLE for Korean soils were reevaluated to estimate the national scale of soil loss based on digital soil maps. Rainfall erosivity factor, R, of 158 locations of cities and counties were spacially interpolated by the inverse distance weight method. Soil erodibility factor, K, of 1321 soil phases of 390 soil series were calculated using the data of soil survey and agri-environmental quality monitoring. Topographic factor, LS, was estimated using soil map of 1:25,000 scale with soil phase and land use type. Cover management factor, C, of major crops and support practice factor, P, were summarized by analyzing the data of lysimeter and field experiments for 27 years (1975-2001) in the National Institute of Agricultural Science and Technology. R factor varied between 2322 and 6408 MJ mm $ha^{-1}$ $yr^{-1}$ $hr^{-1}$ and the average value was 4276 MJ mm $ha^{-1}$ $yr^{-1}$ $hr^{-1}$. The average K value was evaluated as 0.027 MT hr $MJ^{-1}$ $mm^{-1}$. The highest K factor was found in paddy rice fields, 0.034 MT hr $MJ^{-1}$ $mm^{-1}$, and K factors in upland fields, grassland, and forest were 0.026, 0.019, and 0.020 MT hr $MJ^{-1}$ $mm^{-1}$, respectively. C factors of upland crops ranged from 0.06 to 0.45 and that of grassland was 0.003. P factor varied between 0.01 and 0.85.

• Korean Journal of Environment and Ecology
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• v.9 no.2
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• pp.202-210
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• 1996

To investigate edge vegetation struxture and species in Odaesan National park, fild survey was excuted July 1-4, 1995 and the results were as follows. Species compasition of edge(0~10m) was dissimilar to that of forest interior(50m~60m) at (Mt.)Odaesan valley. Species diversity indices, number of species, crown coverage and number of individuals were decreased axxording to distance from edge to forest interior. Weigela subsessilis was appeared to be a competitive species at forest edge in temperate forest and edge species appeared only in Odaesan National Park were Clematis heracleaefolia and Spiraea blumei.

• Journal of Industrial Technology
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• v.36
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• pp.57-63
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• 2016

In this study characteristics of debris flow landslide were investigated on the focus of debris flow disaster occurred by heavy rainfall in 2013 at Goeun-ri around Kaeryoung Mt. in Chuncheon-si. Appropriate method for estimating scale of debris flow was investigated by comparing those values from soil loss by Universal Soil Loss Equation, debris flow yield rate obtained by field survey of investigating debris flow path from initiation and erosion to deposition and other methods. As results of this study, it might be an opportunity of contributing to construct the data base for determining the size of erosion control facilities in future.