• Journal of Wetlands Research
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• v.22 no.2
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• pp.66-72
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• 2020

The coastal sand dunes have transitional characteristics of marine and inland ecosystems, and they have abundant biodiversity. This study investigated flora and vegetation and analyzed the landscape structure at seven beaches in Busan metropolitan city. As a result, the vascular species of the coastal sand dunes in Busan were identified as 178 taxa of 140 families. Vegetation landscape was damaged to the extent that no natural vegetation was found in 4 of 7 beaches (57%). The coastal dune vegetation was dominated by the Carex pumila community and Carex kobomugi community. The halophyte and invasive alien species were classified into 18 taxa (10% of all species) and 40 taxa (22% of all), respectively. The vegetation that made up the largest area was the Phragmites communis community of the salt marsh, and the species number of halophyte increased as the wetland area increased. This means that the maintenance and management of salt marshes is important to conserve the unique plant diversity of the region.

• Korean Journal of Ecology and Environment
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• v.48 no.2
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• pp.122-128
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• 2015

This study aims to figure out the vegetation status and characteristics of the spatial distribution in Taeanhaean National Park. As a result, vegetation communities were Pinus thunbergii community, Pinus densiflora community, Pinus thunbergii-Pinus densiflora community, Camellia japonica community, Carpinus turczaninowii community, Carpinus turczaninowii-Pinus thunbergii community, Kalopanax septemlobus community, Koelreuteria paniculata community, Robinia pseudoacacia community, and sand dune and coastal wetland vegetation including Vitex rotundifolia community, Elymus mollis community, Calamagrostis epigeios community, Ischaemum anthephoroides community, Zoysia sinica community, Suaeda maritima community, and Phragmites communis community. Landscape types in actual vegetation map were Pinus thunbergii community (3.92%), Pinus densiflora community (1.40%), Robinia pseudoacacia community (0.05%), sand dune and coastal wetland vegetation (0.11%), field (0.46%), seashore (0.24%), thinning area (0.08%), bareground (0.16%), and sea (93.58%). Area of Pinus thunbergii community among vegetation type was $14.797km^2$ (3.92%) and the largest. Stratification structure and species composition of Pinus thunbergii community distributed in the seashore were different as a result of disturbance and human use. On the other hand, we assumed that succession will take place to the potential natural vegetation that is Quercus serrata and Quercus dentata in undisturbed Pinus thunbergii community. Meanwhile, Erechtites hieracifolia was occupied in understory of Pinus thunbergii community around the seashore and Diodia teres was invaded to sand dune vegetation. They may affect on natural species negatively. Therefore, monitoring and management plans are necessary.

• The Korean Journal of Nuclear Medicine
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• v.34 no.5
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• pp.418-425
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• 2000

Purpose: There is no established formula for estimating renal depths in Korean. As a result, we undertook this study to develop a new formula, and to apply this formula in the calculation of glomerular filtration rate (GFR). Materials and Methods: We measured the renal depth (RD) on the abdominal CT obtained in 300 adults (M:F: 167:133, mean age 50.9 years) without known renal diseases. The RDs measured by CT were compared with the estimated RDs based on the Tonnesen and Taylor equations. New formulas were derived from the measured RDs in 200 out of 300 patients based on several variables such as sex, age, weight, and height by multiple regression analysis. The RDs estimated from the new formulas were compared with the measured RDs in the remaining 100 patients as a control. In 48 patients who underwent Tc-99m DTPA renal scintigraphy, GFR was measured with three equations (new formula, Tonnesen and Taylor equations), respectively, and compared with each other. Results: The mean values of the RDs measured from CT were 6.9 cm for right kidney of the men (MRK), 6.7 cm for left kidney of the men (MLK), 6.7 cm for right kidney of the women (WRK), and 6.6 cm for left kidney of the women (WLK). The RDs estimated from Tonnesen equation were shorter than the ones measured from CT significantly. The newly derived formulas were 12.813 (weight/height)+0.002 (age)+ 2.264 for MRK, 15.344 (weight/height)+0.011 (age)+0.557 for MLK, 12.936 (weight/height)+ 0.014 (age)+1.462 for WRK and 13.488 (weight/height)+0.019 (age)+0.762 for WLK. The correlation coefficients of the RD measured from CT and estimated from the new formula were 0.529 in MRK, 0.729 in MLK, 0.601 in WRK, and 0.724 in WLK, respectively. The GFRs from the new formula were significantly higher than those from the Tonnesen equation significantly, which was the most similar to normal GFR values. Conclusion: We generated new formulas for estimating RD in Korean from the data by CT. By adopting these formulas, we expect that GFR can be measured by the Gates method accurately in Korean.

• The Korean Journal of Nuclear Medicine
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• v.35 no.2
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• pp.89-99
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• 2001

Purpose: In this study, we developed a new software tool for the analysis of renal scintigraphy which can be modified more easily by a user who needs to study new clinical applications, and the appropriateness of the results from our program was studied. Materials and Methods: The analysis tool was programmed with IDL5.2 and designed for use on a personal computer running Windows. For testing the developed tool and studying the appropriateness of the calculated glomerular filtration rate (GFR), $^{99m}Tc$-DTPA was administered to 10 adults in normal condition. In order to study the appropriateness of the calculated mean transit time (MTT), $^{99m}Tc-DTPA\;and\;^{99m}Tc-MAG3$ were administered to 11 adults in normal condition and 22 kidneys were analyzed. All the images were acquired with ORBITOR. the Siemens gamma camera. Results: With the developed tool, we could show dynamic renal images and time activity curve (TAC) in each ROI and calculate clinical parameters of renal function. The results calculated by the developed tool were not different statistically from the results obtained by the Siemens application program (Tmax: p=0.68, Relative Renal Function: p:1.0, GFR: p=0.25) and the developed program proved reasonable. The MTT calculation tool proved to be reasonable by the evaluation of the influence of hydration status on MTT. Conclusion: We have obtained reasonable clinical parameters for the evaluation of renal function with the software tool developed in this study. The developed tool could prove more practical than conventional, commercial programs.

• Korean Journal of Environment and Ecology
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• v.22 no.5
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• pp.505-513
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• 2008

The purpose of this study is to analyze the distribution patterns and characteristics of plant species by human impact in urban areas. In order to achieve a comprehensive data acquisition of all autogenously introduced vascular plant species occurring in the city of Cheon-ju, this study made an analysis of 106 sample plots, each with a size of one hectare, These sample plots were selected to represent the typical land-use patterns within the city of Cheon-ju and to cover the various distances from the city center. Species richness, patterns of life forms, and the percentage of non-native species were analyzed in relation to the degree of hemeroby of the sample plots. It was found that the species number appeared the largest in sites that were moderately influenced. This result corresponds to the intermediate disturbance hypothesis that moderate disturbance leads to an increase in species richness. The flora of sites which were subject to the highest level of human impact, was characterized by a high proportion of annual species and non-native species. In addition, some species were divided into three groups with similar distribution corresponding to land-use type and urban zone: urbanophobic (e.g. Indigofera kirilowii, Prunus sargentii, Rhus trichocarpa), urbanoneutral (e.g. Commelina communis, Erigeron annuus, Metaplexis japonica) and urbanophilus (e.g. Euphorbia supina, Senecio vulgaris, Taraxacum officinale).

• Korean Journal of Plant Tissue Culture
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• v.21 no.1
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• pp.47-53
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• 1994

The effects of light on the production of anthocyanin and betacyanin in cell suspension cultures of Vitis vinifera and Phytolacca americana were investigated. The cell growth of V.vinifera was little affected by exposure to light, but that of P.americana was markedly increased by light than in the dark In suspension cultures of V vinifera maximum accumulation of anthocyanin was observed during the stationary phase in continuous light By contrast, in suspension cultures of R americana, accumulation of betacyanin occured in parallel with cell division which showed two peaks after 4 days and 8 days of culture in continuous light whereas in continuous dark accumulation of anthocyanin and betacyanin did not occured However treatment of light interrupting for l, 12, and 24 h after 4 days in cell suspension. cultures of remarkably showed a slight anthocyanin accumulation, but after 8 days of culture remarkably accumulated by light interrupting for more than 12 h. In cultures of P. americana, the light treatment was more effective at 4th day than at 7th day after culture, but betacyanin accumulation was decreased again in the dark after light treatment These result indicate that the difference of light responses exist between the V.vinifera and the betacyanin of P. americana though cell suspension culture systems.

• Journal of the Korean Geographical Society
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• v.42 no.3 s.120
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• pp.344-354
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• 2007

Estuarine wetlands for 33 watersheds in the Han River estuary were delineated on topographic maps from the 1910s, 1970s, and 2000s. Then, these data were used to address the issue of spatial distribution and temporal variation. Watershed characteristics such as drainage density, location, watershed size, slope, and elevation were identified for each watershed to determine the relationship between watershed characteristics and spatial distribution of estuarine wetlands. The analysis of estuarine wetlands indicated that wetlands in the estuary had declined gradually between the 1910s and the 1970s, although most wetlands were lost since the 1970s mainly caused by the large development projects related to urban expansion in metropolitan Seoul. The sediment composition and formation processes of the wetlands differed with watershed location; mud flats dominate in the lower part of the estuary, and relatively more sandy and emergent-plant wetlands occur near the main channel and tributaries of the Han River. Relatively more estuary wetlands occur in large watersheds, which have high slopes and low elevations. Estuarine wetlands have been lost dramatically in the densely populated watershed regions (i.e., Han River Seoul, Han River Goyang, West Han River), while relatively more wetlands have remained in undeveloped regions, including the Lower Imjin River and Lower Han River. In particular, anthropogenic disturbance has played an important role in the loss of wetland through the conversion of wetland into agricultural and developed land.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.225-225
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• 2023

하상 측정은 하천 유지관리, 수공구조물 설계 및 보수, 수생태 조사의 필수적인 자료이다. 최근 4대강 대규모 사업 이후 자연적 안정화로 인해 침식 및 재퇴적이 진행되어 정밀 하상 모니터링이 요구되고 있다. 통상적인 하상 조사 기법은 레벨측량 및 RTK-GPS 등을 활용하여 점단위로 직접 계측하는 기법과 수심이 깊을 경우 ADCP와 같은 음향측심기법을 통해 하상변동을 계측하고 있다. 하지만 점단위 직접 측정은 사구와 사련과 같은 하상 구조 교란 및 계측 시 위험을 동반하고 수심자료의 측정오차가 크게 발생하는 한계점이 존재한다. 또한 초음파 방식의 경우 막음길이와 바닥면 노이즈 등의 한계점으로 50 cm 미만의 저수심부 하상 측정이 불가능한 실정이다. 이러한 한계점을 극복하기 위해 최근 드론의 보급으로 수심라이다(Bathymetry LiDAR), SFM, 드론 탑재 초분광 영상을 활용한 초분광수심법과 같은 저고도, 고해상도의 비접촉식 면단위 하상 측정 기법이 대안으로 각광받고 있고 최근 관심은 해당 최신 기술의 성능 점검 및 적용성 평가에 있다. 따라서 본 연구에서는 초분광수심법 중 보편적으로 적용할 수 있는 최적밴드비분석(OBRA)의 성능 점검과 실무 적용성을 국내 하천을 대상으로 검토하였다. 해당 기술의 실무 적용성 평가항목 중 수심 적용 범위가 경제적이고 효율적인 성능 평가의 주된 항목이다. 선행 연구에 따르면 감천을 대상으로 저수심부의 성능 평가를 진행한 결과 상세한 하상계측이 가능하다고 제시하였다. 따라서 본 연구는 낙동강-황강 합류부를 대상으로 전형적인 평수기 탁도 조건에서 초분광수심법을 적용할 경우 최대측정가능수심의 범위를 결정하는 방법 및 결과를 제시하려고 한다. 또한 현장실험 당시 합천댐 방류로 인하여 황강의 탁도가 높아진 상태에 기인하여 고탁도 조건에서 초분광수심법의 적용성 평가도 추가 검토하였다. 해당 연구는 수심과 밴드비의 비선형성을 통해 최적 밴드비 분석의 결과로 도출될 수 있는 상관계수와 평균 제곱근 오차(RMSE)의 동향을 보아 다양한 시나리오의 배제수심을 통해 최대측정가능수심을 산정하였으며 그 이상의 범위는 수심맵 산정에서 제외하였다. 그 결과로 낙동강 본류에서 2.5 m 이하, 황강 지류에서 1.25 m 이하의 최대측정가능수심이 나타났고 해당 범위 이하에서는 상세한 하상이 나타났다. 또한 고탁도 조건인 황강에서는 낙동강에 비해 절반 수준의 최대측정가능수심 범위가 나타나 탁도 조건에 따른 초분광수심법의 한계가 있는 것을 확인하였다.