• 한국자원식물학회지
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• 제24권3호
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• pp.314-318
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• 2011

Saururus chinensis is used as a raw material of an anti-rheumatic, poultice, sedative and stomachic. The tea of dried Saururus chinensis leaves has a function of relaxing pains in back and breast and of treating stomach ailments. The plant has the functions of anti-inflammatory, depurative, diuretic, febrifuge and refrigerant. The extraction of functional material is carried out by methanol and ethanol solvents. Mechanochemical grinding is applied as a pretreatment process before extraction to enhance the extraction efficiency by increasing the surface area of the materials while changing the chemical properties of the materials. Extraction of functional materials from the Saururus chinensis after grinding as a pretreatment using the mechanochemical technology was accomplished in this study to investigate the effect of grinding on the antioxidant activities of the extract. Saururus chinensis was ground by the planetary ball mill and the morphology was analyzed by SEM. Mechanochemical pretreatment increased the yields of functional materials from 5.9 g to 6.4, 7.0, and 8.1 g after grinding of 30 minutes, 1 hour and 2 hours, respectively. Nitrite scavenging ability increased from 53.0-71.0% to 61.0-79.0% for the methanol extraction in the solution of pH 1.2. Also, Electron donating abilities were increased from 7.90-33.51% to 11.97-38.51% for the methanol extraction. The extract concentration for the half inhibition of DPPH radicals was reduced from $278{\mu}g/mL$ in the original sample to $263{\mu}g/mL$ in the sample after grinding for the methanol extraction.

• 수산해양기술연구
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• 제40권4호
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• pp.282-294
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• 2004

아르헨티나 짧은지느러미오징어는 1993년에 99,000톤에서 1994년 56,600톤으로 감소하고 1996년에는 78,600톤에서 1997년 130,300톤으로 다시 증가하였다. 어획량의 급감 및 급증한 1993~1994년과 1996~1997년의 성어기인 3~5월의 풍도 원인을 구명하기 위하여 아르헨티나 짧은지느러미오징어의 수온 변동에 따른 풍도 변화를 분석하였다. 호황을 보였던 해인 1993년과 1997년은 성어기에 주로 50$^{\circ}$~51$^{\circ}$S간 해역에서 주어장이 형성되었고, 불황을 보였던 1994년과 1996년에는 50$^{\circ}$S이북에서 성어기 어장이 형성되었으며 포클랜드 어장의 평균수온은 3월 10~11$^{\circ}$C, 4~5월은 9$^{\circ}$C로 평균 등온선이 형성되는 위치에 따라 어황이 변동하는 것으로 나타났다. 아르헨티나 짧은지느러미오징어의 높은 단위노력 당어획량(kg/line) 및 어획량은 어장이 포클랜드 해류의 영향을 받지 않은 1993년 및 1997년은 호황을 보였고, 북상하는 포클랜드 해류의 영향을 받은 1994년 및 1996년에는 급격히 감소되어 불황을 보였다.

• 한국수산과학회지
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• 제53권5호
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• pp.773-783
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• 2020

In order to evaluate the recovery of fishing ground environment after the cessation of aquaculture farming, we examined the variation in sediment quality over time using different geochemical factors and investigated whether these factors are indicators of sediment quality recovery. The study area was an oyster Crassostrea gigas, farm in Tongyeong, Geyongsangnam-do, South Korea, where aquaculture activities had been carried out for 20 years, and the changes in water and sediment environment were monitored for 14 months after the abandonment of the farm. The mean water depth was 14 m, with a tidal range of 3 m, and seawater current velocity ranged from 4.7 to 7.0 cm/s. After the abandonment of the farm, total organic carbon and total nitrogen concentrations in the surface sediments decreased significantly over time compared to those in the control site; in particular, immediately after farm abandonment, acid-volatile sulfide concentrations decreased relatively rapidly. Carbohydrate and protein concentrations in the sediments showed no significant changes; however, lipid concentrations markedly decreased. Further studies on other aquaculture taxa and various aquaculture areas are needed to establish new policies for environmental management of fishing grounds, such as relocation of fishing grounds and determination of optimal fallowing periods.

• Ocean and Polar Research
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• 제39권2호
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• pp.159-168
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• 2017

To evaluate the accuracy of UAV photogrammetry for Hyangho coast, eastern coast of Korea, we conducted a field experiment wherein UAV photogrammetry test was repeated three times. Since the Haygho coast is located within a military reservation zone, it was necessary to obtain permission to gain access to the beach and to have sensitive aerial photographs showing military facilities inspected and cropped. The standard deviation of the UAV shooting position between the three tests was less than 1 m, but repeatability of footprint on the ground was low due to wind-driven variability of the UAV pose. Self-calibrating bundle adjustment(SCBA) of implementing non-metric camera calibration was failed in one test. In two tests, the vertical error was twice as large as the pixel size except for those areas that were subject to security inspection and cropping. Given the problems that can arise with regard to the repeatability of the shooting area as well as the possibility of failure with regard to SCBA, we strongly recommend that UAV photogrammetry in coastal areas needs to be repeated at least twice.

• 대한토목학회논문집
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• 제5권3호
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• pp.85-93
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• 1985

1978년(年) NOAA/NASA의 SEASAT 위성(衛星) 고도계자료(高度計資料)를 이용(利用)한 동지나해(東支那海)의 해면변위(海面變位)를 연구(硏究)하기 위한 초기노력(初期努力)이 서술(敍述)되었다. SEASAT 운용기간중(運用期間中)의 동지나해(東支那海)의 두 태풍통과시기(颱風通過時期)를 선택(選擇)하여 공간적(空間的), 시간적(時間的) 변화도(變化度)가 큰 천해조석(淺海潮汐), 해일(海溢) 및 지구조석(地球潮汐)에 대한 고도계(高度計) 자료경정(資料更正)을 하였는 바 일련(一連)의 작업(作業)을 일관(一貫)된 고도계처리체계(高度計處理體系)를 수립(樹立)하여 수행(遂行)하였다. 초기결과I(初期結果)들이 제시(提示)되었으며 추후(追後)의 연구(硏究)에 대한 토의(討議)를 하였다. 본(本) 연구(硏究)는 추후(追後) 이용가능(利用可能)한 해양위성(梅洋衛星)의 고도계자료(高度計資料)를 철저(徹底)하게 이용(利用)하여 동지나해(東支那海)의 국지해양학적(局地海洋學的)인 특성(特性)을 규명(糾明)하기 위한 첫 시도(試圖)로서 수행(遂行)된 것이다.

• 한국환경복원기술학회지
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• 제16권6호
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• pp.93-107
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• 2013

Construction of an artificial wetland for the growth of Sphagnum palustre with emergent macrophytes (Phragmites australis, Typha angustifolia, and Zizania latifolia) was firstly tried and the growth of those plant components according to various environmental combinations has been monitored for three years. Above-ground dry weight of Z. latifolia ($1,500g/m^2$) was higher than T. angustifolia ($900g/m^2$) and P. australis ($500g/m^2$) under most environmental conditions. In overall, planted emergent macrophytes seemed to prefer polishing sand without moss peat as a substrate and relatively deep water-depth condition (20cm) rather than shallow water-depth (5cm). Despite of high calcium content in inflow water (> 15ppm) into the constructed wetland, S. palustre populations have survived in most experimental plots during the monitoring period. Substrate layer including moss peat with high surface-area might play a role as an ion-filter. After three years, relatively thicker litter-layer in Z. latifolia plots due to vigorous growth appeared to heavily depress S. palustre by physical compressing and complete shading processes. Most of all, for the continuous growth of S. palustre, physio-chemical characteristics of water and substrate must be carefully managed. In addition, companion emergent species should be also cautiously selected not to depress S. palustre by much litter production. We suggest P. australis and T. angustifolia as companion species rather than Z. latifolia.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2007년도 Proceedings of ISRS 2007
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• pp.294-297
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• 2007

Steam and advection fogs are frequently observed in the Yellow Sea located between Korea and China during the periods of March-April and June-July respectively. This study uses the remote sensing (RS) data for monitoring sea fog. Meteorological data obtained from the Ieodo Ocean Research Station provided an informative synopsis for the occurrence of steam and advection fogs through a ground truth. The RS data used in this study was GOES-9, MTSAT-1R images and QuikSCAT wind data. A dual channel difference (DCD) approach using IR and near-IR channel of GOES-9 and MTSAT-1R satellites was applied to estimate the extension of the sea fog. For the days examined, it was found that not only the DCD but also the texture-related measurement and the weak wind condition are required to separate the sea fog from the low cloud. The QuikSCAT wind is used to provide a weak wind area less than threshold under stable condition of the surface wind around a fog event. The Laplacian computation for a measurement of the homogeneity was designed. A new combined method of DCD, QuikSCAT wind speed and Laplacian was applied in the twelve cases with GOES-9 and MTSAT-1R. The threshold values for DCD, QuikSCAT wind speed and Laplacian are -2.0 K, 8 m $s^{-1}$ and 0.1, respectively. The validation methods such as Heidke skill score, probability of detection, probability of false detection, true skill score and odds ratio show that the new combined method improves the detection of sea fog rather than DCD method.

• 한국정밀공학회지
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• 제17권7호
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• pp.113-123
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• 2000

In the navigation for a mobile robot, the collision avoidance with unexpected obstacles is essential for the safe navigation and it is independent of the technique used to control the mobile robot. This paper presents a new collision avoidance algorithm using neural network for the safe navigation of the autonomous mobile robot equipped with CAN and ultrasonic sensors. A tracked wheeled mobile robot has a stability and an efficiency to move on a rough ground. And its mechanism is simple. However it has difficulties to recognize its surroundings. Because the shape of the tracked wheeled mobile robot is a square type, sensor modules are generally located on the each plane surface of 4 sides only. In this paper, the algorithm using neural network is proposed in order to avoid unexpected obstacles. The important character of the proposed algorithm is to be able to detect the distance and the angle of inclination of obstacles. Only using datum of the distance and the angle, informations about the location and shape of obstacles are obtained, and then the driving direction is changed. Consequently, this algorithm is capable of real time processing and available for a mobile robot which has few sensor modules or the limited sensing range such as a tracked wheeled mobile robot. Effectiveness of the proposed algorithm is illustrated through a computer simulation and an experiment using a real robot.

• 한국측량학회지
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• 제26권4호
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• pp.341-350
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• 2008

변화탐지는 도시모델의 갱신을 위해 중요한 단계이다. 이에 본 연구는 서로 다른 시기에 취득된 라이다 데이터로부터 도시변화를 탐지하는 방법을 제안한다. 제안된 방법의 주요 과정은(1) 라이다 데이터로부터 생성된 DSM의 차분을 통해 변화영역을 탐지하고, (2) 탐지된 영역의 라이다 점으로부터 표면패치를 구성하고, (3) 구성된 각각의 패치의 종류를 지면, 수목, 빌딩으로 분류하고, (4) 패치의 종류 및 속성에 기반하여 변화의 종류를 결정한다. 제안된 방법을 실측데이터에 적용한 결과를 동일한 지역의 정사영상으로부터 육안검사를 통해 수동생성된 참조데이터를 이용하여 검증하였다. 변화탐지의 성공률은 평균적으로 97%로 평가되었다. 결론적으로 제안된 방법은 변화탐지 및 도시모델의 갱신을 위한 신뢰성이 높고, 효율적인 방법으로 판단된다.

• 스마트미디어저널
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• 제9권2호
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• pp.22-32
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• 2020

The hippocampal volume atrophy is known to be linked with neuro-degenerative disorders and it is also one of the most important early biomarkers for Alzheimer's disease detection. The measurements of hippocampal pure volumes from Magnetic Resonance Imaging (MRI) is a crucial task and state-of-the-art methods require a large amount of time. In addition, the structural brain development is investigated using MRI data, where brain morphometry (e.g. cortical thickness, volume, surface area etc.) study is one of the significant parts of the analysis. In this study, we have proposed a patch-based ensemble model of 3-D convolutional neural network (CNN) to measure the hippocampal pure volume from MRI data. The 3-D patches were extracted from the volumetric MRI scans to train the proposed 3-D CNN models. The trained models are used to construct the ensemble 3-D CNN model and the aggregated model predicts the pure volume in one-step in the test phase. Our approach takes only 5 seconds to estimate the volumes from an MRI scan. The average errors for the proposed ensemble 3-D CNN model are 11.7±8.8 (error%±STD) and 12.5±12.8 (error%±STD) for the left and right hippocampi of 65 test MRI scans, respectively. The quantitative study on the predicted volumes over the ground truth volumes shows that the proposed approach can be used as a proxy.