• Journal of Conservation Science
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• v.26 no.2
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• pp.121-132
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• 2010

The Bukjiri Maaeyeoraejwasang (National Treasure No. 201) consists of two-mica granite in medium size, which was the simbol of power in the region of the Silla period. Magnetic susceptibility of the host rock was measured as 0.41(${\times}10^{-3}$ SI unit), which has the similar range with surrounding outcrop. The Buddha developed parallel discontinuous plane of NE to SW strike and damaged seriously by exfoliation, granular disintegration and brown discoloration as 41.5%, 16.7% and 40.0%, respectively. As a result of the ultrasonic velocity, which was relatively weak values as 1,629m/s (Buddha area) and 1,549m/s (surrounding outcrop), improved about 900m/s compared to last treatment. From the results of the evaluation for slope stability, identified the possibility of toppling failure in the Buddha, and planar and wedge failure in host rock. Therefore, we suggest for the safely conservation of the Buddha, continuance monitoring for understand behavior of discontinuity system of the surface, and necessitate foundation reinforcement method for the rock which has the danger of collapse.

• Korean Journal of Food Science and Technology
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• v.43 no.3
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• pp.277-281
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• 2011

A rapid and very sensitive high-performance liquid chromatography/atmospheric-pressure chemical-ionization mass spectrometry method to detect ethylenethiourea (ETU) fungicide residues in fruits was developed. Methylene chloride was used as the surface extraction solvent for the target component. Recovery rates improved when cysteine hydrochloride and sodium carbonate were added to product prior to fortification. The limits of detection and quantification were approximately 0.006 and 0.02 mg/kg, respectively, from mandarin oranges. Recoveries from mandarin oranges, oranges, bananas, and pears, spiked in the range of 0.05-0.5 mg/kg, averaged 80-100%. The proposed method was used to monitor the presence of ETU in commercial fruits purchased from different markets in Seoul, Korea. ETU was found in four orange peels and in three mandarin orange peel samples. The highest ETU residue levels were $73.6{\mu}g/kg$ and $29.8{\mu}g/kg$.

• Journal of Food Hygiene and Safety
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• v.35 no.4
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• pp.326-333
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• 2020

In this work, we developed an analytical method for determining 11 illicit compounds in dietary supplements using high-performance liquid chromatography and liquid chromatography-tandem mass spectrometry. Eleven target compounds, including those meant for weight loss (7-keto-dihydroepiandrosterone, buformin, metformin, phenformin, salbutamol, and tolbutamide), sexual enhancement (dihydroepiandrosterone), and relaxation (asarone, kavain, magnoflorine, and picamilon) were screened and confirmed in dietary supplements. Method validation was performed by evaluating the selectivity, linearity, limit of quantification (LOQ), accuracy, and precision according to the Association of Official Analytical Chemists guidelines. The linearity was > 0.993 for all analytes. The LOQs were ranged in 2.1-9.9 ㎍/mL (HPLC-DAD) and 0.002-0.008 ㎍/mL (LC-MS/MS). The accuracies (expressed as recovery) were 90.0-106% (HPLC-DAD) and 83.0-114% (LC-MS/MS). The precision (expressed as the relative standard deviation) was below 10% using HPLC and LC-MS/MS. The proposed method can be used for the surveillance of illicit compounds in dietary supplements.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.27 no.6
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• pp.639-647
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• 2009

In line with the rapid settlement of information society, the demand for geospatial information and its applications are dramatically increasing. The Project of National Geographic Information System(NGIS) is actively on going to meet up-to-dateness and accuracy of geospatial data. It is fact that the public interest in environmental issues is increasing than ever in accordance with the restoration of the four major rivers, core project of Green New Deal Policy, and the event of the Ramsar General Meeting. Because the Nakdong River Estuary is a place of great importance in both aspects of wetland and environment conservation, a variety of researches related to this area are progressing. Although artificial developments and natural phenomena are rapidly changing the topography and ecosystem of this area, the effort to build topographic DB for change monitoring is very slow. This study describes a Lidar surveying project over the restored wetland Eulsukdo, the southermost part of the Nakdong River, to establish precise topographic DB throughout producing 3D topographical maps and wetland classification maps. The results of this study will make a large contribution to the systematic maintenance and management for the restored Eulsukdo wetland.

• Analytical Science and Technology
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• v.29 no.4
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• pp.202-208
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• 2016

본 연구에서는 사료 첨가제로 이용되고 있는 유기산 7종(formic acid, malic acid, lactic acid, acetic acid, citric acid, fumaric acid, propionic acid)의 동시분석법 개발을 위한 연구를 실시하였다. 7종의 화합물은 표준물질의 Retention time과 UV spectra를 통해 구별하였고, 분석법 검증은 직선성, 민감성, 선택성, 정확성, 정밀성을 통하여 검증하였다. 그 결과로 LOD와 LOQ의 범위가 각각 43~26,755 μg/kg, 12-8,026 μg/kg으로 설정하였고, 평균 회수율이 79.3~95.2%로 우수하게 보였으며, intra-day, inter-day에 대한 전반적인 상대 표준 편차(%RSD)는 3.2% 미만으로 나타났다. 이와 같이 검증된 자료를 통해 유기산의 동시분석에 대한 직선성, 민감성, 선택성, 정확성 및 정밀성을 확인하였고, 높은 수준을 나타냄을 알 수 있었다. 이를 바탕으로 유기산이 검출되는 단미사료 46 가지를 분석에 적용하여 진행하였고, 정량과 동시분석 검출을 위한 방법은 RP-HPLC/UV 검출기를 이용하여 성공적으로 개발되었다. 따라서 본 연구결과를 바탕으로 하여 사료 중의 유기산의 분석이 신속하고 정확해졌을 뿐 아니라, 다른 종류의 사료 또한 이를 적용하여 효율적으로 이용할 수 있을 것으로 판단된다.

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.103-103
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• 2012

본 연구에서는 시험포장($1276.6m^2$)에서의 지표피복 BMPs (Best Management Practices) 시나리오를 적용하여 얻은 평균 유출저감율을 HSPF 모델에 적용하여 유역차원에서의 비점원오염 저감효과를 평가하고자 한다. 본 연구에서는 별미천 유역($1.21km^2$)을 대상으로 모형의 적용을 위한 입력자료로 기상자료와 지형자료를 구축하였으며 기상자료로 수원, 양평, 이천 기상관측소 자료를 구축하였으며, 지형자료로 격자크기 2m의 DEM (Digital Elevation Model)과 토지이용도는 2006년 5월 1일 QuickBird 영상을 제공받아 기존 환경부, 건교부, USGS의 토지피복분류체계 및 현장조사를 통하여 QuickBird 영상으로부터 추출 가능한 정밀농업정보에 대한 항목을 결정하였으며, 정사보정된 QuickBird 영상을 스크린 디지타이징 기법(On-Screen Digitizing Method)을 이용하여 총 21개 토지이용항목의 정밀토지이용도를 구축하였다. 실제모니터링으로 측정된 자료를 바탕으로 수위-유량곡선 산정 및 오염부하곡선을 선정, 2011년 6월 8일부터 10월 31일 분석기간으로 HSPF 모델링을 실시하였으며 모의결과 월별 통계에 따른 적용성 분석으로 RMSE (Root Mean Square Error) 는 1.15 ~ 1.76(mm/day), $R^2$는 0.62 ~ 0.78, Nash-Sutcliffe model efficiency (NSE)는 0.62 ~ 0.76로 모의치는 실측치와 유의성이 있는 것으로 분석되었다. 또한, Sediment, T-N, T-P의 $R^2$는 각각 0.72, 0.62, 0.63으로 상관성을 보이는 것으로 분석되었다. 시험포장으로부터 얻어진 event별 볏짚을 이용한 지표피복시나리오적용 후 밭에서의 평균 유출 약 10 % 유출율 감소 조건과 실제 평균 비점원오염 저감효과 89.7 % ~ 99.4 %의 결과로부터 지표피복효과의 침투효과를 HSPF 모델로 적용하기 위해 침투량(INFILT)를 조절하여 평균유출 약 10 %가 감소되는 16.0 mm/hr 값을 선정하였다. 그 결과, Sediment. T-N, T-P의 평균 저감율은 각각 87.2 %, 28.5 %, 85.1 %로 나타났으며 이는 시험포장에서의 실제 평균 비점오염 저감효과 89.7 % ~ 99.4 %에 근접함을 알 수 있었다. 이 결과로부터 침투량 조절에 따른 지표피복(침투짚단)효과는 Sediment, T-P에서 저감효율이 80 % 이상으로 높았지만 T-N은 약 30 %로 낮은 저감율을 보임으로써 저감효과가 크지 않음을 나타냈다.

• Journal of the Korea Organic Resources Recycling Association
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• v.27 no.2
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• pp.67-73
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• 2019

In this study, to optimize the production and utilization of biogas for organic waste resources, the precision monitoring of on-site facilities and the energy balance by facility were analyzed, and the solutions for field problems were investigated, and the design and operation guidelines for pretreatment facilities and generators were presented. Gas pre-treatment is required to solve frequent failures and efficiency degradation in operation of high quality refining facilities, and processing processes such as desulfurization, dehumidification, deoxidization, dust treatment, volatile organic compounds, etc. Since these processes are substances that are also eliminated from the high-quality process, quantitative guidelines are not presented in the gas pretreatment process, but are suggested to operate during the processing process as a qualitative guideline. In particular, dust, siloxane, and volatile organic compounds are the main cause of frequent failure of high-quality processes if they are not removed from the gas pretreatment process. Design of the biogas high-quality process. The operation guidelines provide quality standards [Methane content (including propane) of 95% or more] with 90% or more utilization of the total gas generation, two systems, and a margin of 10% or more. It also proposed installing gas equalization tank, installing thermal automatic control system for controlling equalization of auxiliary fuel, installing dehumidification device at the back of high quality for removing moisture generated in the process of gas compression, installing heat-resisting facilities to prevent freezing of facilities in winter and reducing efficiency, and installing membrane facilities in particular.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.36 no.4
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• pp.105-112
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• 2018

This study aims to apply 3D scanning technology to the field of landscape planning design. Through this, 3D scans were conducted on Soswaewon Garden and Seongrakwon Gardens to find directions for traditional landscape planning and designs. The results as follows. First, the actual measurement of the traditional garden through a 3D scan confirmed that a precise three-dimensional modeling of ${\pm}3-5mm$ error was constructed through the merging of coordinate values based on point data acquired at each observation point and postprocessing. Second, as a result of the 3D survey, the Soswaewon Garden obtained survey data on Jewoldang House, Gwangpunggak Pavilion, the surrounding wall, stone axis, and Aeyangdan wall, while the Seongnakwon Garden obtained survey data on the topography, rocks and waterways around the Yeongbyeokji pond area. The above data have the advantage of being able to monitor the changing appearance of the garden. Third, spatial information developed through 3D scans could be developed with a three-dimensional drawing preparation and inspection tool that included precise real-world data, and this process ensured the economic feasibility of time and manpower in the actual survey and investigation of landscaping space. In addition, modelling with a three-dimensional 1:1 scale is expected to be highly efficient in that reliable spatial data can be maintained and reprocessed to a specific size depending on the size of the design. In addition, from a long-term perspective, the deployment of 3D scan data is easy to predict and simulate changes in traditional landscaping space over time.

• Journal of Korean Society of Forest Science
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• v.111 no.2
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• pp.302-310
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• 2022

Here we aimed to classify the major coniferous tree species (Pinus densiflora, Pinus koraiensis, and Larix kaempferi) by tree measurement information and machine learning algorithms to establish an efficient forest management plan. We used national forest monitoring information amassed over nine years for the measurement information of trees, and random forest (RF), XGBoost (XGB), and light GBM (LGBM) as machine learning algorithms. We compared and evaluated the accuracy of the algorithm through performance evaluation using the accuracy, precision, recall, and F1 score of the algorithm. The RF algorithm had the highest performance evaluation score for all tree species, and highest scores for Pinus densiflora, with an accuracy of about 65%, a precision of about 72%, a recall of about 60%, and an F1 score of about 66%. The classification accuracy for the dominant trees was higher than about 80% in the crown classes, but that of the co-dominant trees, the intermediate trees, and the overtopper trees was evaluated as low. We consider that the results of this study can be used as reference data for decision-making in the selection of thinning trees for forest management.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.39 no.6
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• pp.541-548
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• 2021

Recently, multispectral cameras are being actively utilized in various application fields such as agriculture, forest management, coastal environment monitoring, and so on, particularly onboard UAV's. Resultant multispectral images are typically georeferenced primarily based on the onboard GPS (Global Positioning System) and IMU (Inertial Measurement Unit)or accurate positional information of the pixels, or could be integrated with ground control points that are directly measured on the ground. However, due to the high cost of establishing GCP's prior to the georeferencing or for inaccessible areas, it is often required to derive the positions without such reference information. This study aims to provide a means to improve the georeferencing performance of a multispectral camera images without involving such ground reference points, but instead with the simultaneously onboard high resolution RGB camera. The exterior orientation parameters of the drone camera are first estimated through the bundle adjustment, and compared with the reference values derived with the GCP's. The results showed that the incorporation of the images from a high resolution RGB camera greatly improved both the exterior orientation estimation and the georeferencing of the multispectral camera. Additionally, an evaluation performed on the direction estimation from a ground point to the sensor showed that inclusion of RGB images can reduce the angle errors more by one order.