• Economic and Environmental Geology
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• v.44 no.6
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• pp.475-483
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• 2011

Quantitative estimate of manganese nodules based on the operation of a free fall grab (FFG) needs to be corrected because of its less retrieval ability. Previously, the correction parameter of the nodule abundance collected by FFG was calculated based on the image analysis of the photos of bottom sediment in the northern sector of the nodule exploration area of Korea in the NE equatorial Pacific. However, nodules in the southern sector are commonly covered by sediment, which may prevent the use of the correction parameter estimated by photographic techniques. In this study, we attempted dual nodule sampling at the same location by different equipments (i.e. box corer (BC) and FFG) to examine the previous correction parameter of nodule abundance for FFG operation. During the exploration cruises in 2007 to 2009, Mn-nodules were collected from 40 stations both by BC and FFG in the southern sector. The correlation analysis between BC and FFG operations revealed that the BC collected nodules 1.43 times larger than FFG. Our result suggests that the correction parameter of 1.43 can be applied for collection of FFG data to estimate Mn-nodule distribution in the southern sector. The obtained parameter is similar to the previous parameter (1.42~1.45) calculated by the image analysis method, indicating an usefulness of new correction parameter suggested by this study.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.05b
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• pp.114-118
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• 2005

본 연구에서는 특정 유역의 토양수분 상태, 한계유출량(threshold runoff) 및 단기 기상예보 자료 등으로부터 돌발홍수능(Flash Flood Guidance, FFG)을 계산할 수 있는 실시간 돌발홍수 예경보시스템을 개발하기 위해 한강유역을 대상으로 DEM 자료를 이용하여 미세 소유역을 구분하고 하도단면 특성을 고려한 제방 월류 유량 개념을 기초로 고해상도 소유역 단위의 한계유출량을 산정하고, 중규모 TOPMODEL의 토양수분 모델을 통해 임의 상태의 토양수분을 추정할 수 있도록 개발하였다 또한, FFG 시스템의 기상학적 구성요소 개발을 위해 레이더 강우 추정을 편차보정 기법을 통해 계산하였다. 상술된 계산결과를 바탕으로 2003년 7월의 호우사상에 대한 유역 및 격자기반의 FFG를 산정하였고, 이들 결과는 기상청의 RDAFS(Regional Data Assimilation and Prediction System) 단기 수치예보 자료의 지속시간별 예측강수량을 활용하여 돌발홍수 발생에 대한 사례연구를 수행하였다.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.221-225
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• 2006

본 연구에서는 한계유출량(threshold runoff), 특정 유역의 토양수분 상태 및 단기 기상예보 자료 등으로부터 한강유역의 돌발홍수능(Flash Flood Guidance, FFG)을 계산할 수 있는 한국형 돌발홍수 예경보시스템을 개발하였다. 한강유역의 DEM 자료를 이용하여 미세 소유역을 구분하고 하도단면 특성을 고려한 제방 월류유량 개념을 기초로 고해상도 미세 소유역 단위의 지속시간별 한계유출량을 산정하였고, Sacramento 토양수분 모델을 통해 임의 시간의 토양수분 상태를 실시간으로 추정할 수 있는 돌발홍수 모델의 수문학적 구성요소를 개발하였다. 또한, FFG 시스템의 기상학적 구성요소로 레이더 강우 추정을 추계 동역학적 편차보정 기법을 통해 계산하였다. 상술된 수문 및 기상학적 구성요소를 바탕으로 2003년 7월 및 2004년 8월의 호우사상에 대한 유역기반의 FFG를 산정하였고, 기상청의 RDAPS(Regional Data Assimilation and Prediction System) 단기 수치예보 자료의 지속시간별 예측강수량을 활용하여 돌발홍수 발생 가능성에 대한 사례연구를 수행하였다.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.13 no.3
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• pp.280-285
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• 2008

Manganese nodule abundance estimated based on operation of a Free Fall Grab(FFG) needs to be corrected to make up for its incomplete recovery of nodule, because FFGs can not recover all the nodules distributed on seabed. The correction factor for nodule abundance was proposed as 1.29 and 1.13 in 1994 and 2002, respectively, mainly based on the analyses of seabed images. In this study we collected manganese nodules using both FFG and Box Corer(BC) at same stations to examine the accuracy of the previous correction factors. It was found that the nodule recovery of the BC was 1.4 times greater than that of the FFG at the same sampling station, suggesting the necessity of re-evaluation of the previously proposed correction factor for FFG. More extensive sampling and improvement of image analysis method are required to improve the precision of nodule abundance correction factor for FFG.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.4 no.1
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• pp.1-9
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• 2001

Purpose: Gastroesophgeal reflux (GER) is defined as involuntary movement of gastric contents into esophagus. Relaxation of lower esophageal sphincter caused by immature anatomical development in newborn and young infants produces GER frequently. We wanted to know whether the frequency of GER is influenced by feeding types and position or not. We studied in 16 subjects according to feeding types (breast feeding group: BFG-7, formula feeding group: FFG-9) who admitted to the Soonchunhyang university hospital for recurrent regurgitation with 24 hr esophageal pH monitoring from August 1996 to July 1999. Methods: We compared two groups by number of reflux episode, reflux rate, longest episode, numbers of episodes lasting >5 minutes, longest episode in upright position and longest episode in supine position. We used Mann-Whitney test for statistical analysis. Results: 1) The subjects were 7 infants in BFG and 9 infants in FFG, 16 in total, and mean age was 2.1, and 2.6 months for BFG and FFG, respectively. 2) The reflux numbers were $244{\pm}151/day$, $275{\pm}155/day$ for BFG and FFG, respectively. 3) The reflux rate was $14{\pm}15%$ for BFG and $28{\pm}22%$ for FFG. It was lower in BFG. 4) The longest episode was $20{\pm}28$ minutes for BFG and $58{\pm}66$ minutes for FFG. It was significantly longer in FFG. 5) The numbers of episodes lasting >5 minutes were $5{\pm}6$ for BFG and $9{\pm}3$ for FFG. 6) The longest episode in upright position was $10{\pm}8$ minutes for BFG and $40{\pm}47$ minutes for FFG. It was significantly shorter in BFG. 7) The longest episode in supine position was $18{\pm}29$ minutes for BFG and $52{\pm}66$ minutes for FFG. It was significantly shorter in BFG. Conclusion: Breast feeding is strongly recommended to reduce the regurgitation in infancy. It is an another benefit of breast feeding.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.362-362
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• 2020

Flash flood is a dangerous weather phenomenon, affecting humans and the economy. The identification, forecast of the changing trend and its characteristics are increasingly concerned. In the world, there have many methods for determining the characteristics of flash floods, in which flash flood guidance (FFG) is a fast, effective and widely used method. The main source of flash floods is short-term rainfall. In this study, we used the data of cross-sectional measurement at the tributaries and the hourly rain data from the automatic rainfall measurement stations in the Geum river basin. Besides, we use a combination of the flash flood guidance and the best fit distribution function to estimate the repeatability of flash floods for head-water catchments in Geum river basin. In which, FFG determines the threshold of rainfall for flash floods. The study has determined the best hourly rainfall distribution function for the Geum river basin and estimated the maximum rainfall of 1hr according to the return periods.

• Journal of Korea Multimedia Society
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• v.13 no.3
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• pp.378-391
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• 2010

In this paper, it is tested that an individual is able to be identified with finger face images and the results are presented. Special operators, FFG(Facet Function Gradient) masks by which the gradient of a facet function fit on a gray levels of image patches can be computed are used and a new procedure named F-algorithm is introduced to match the finger face images. The finger face image is divided into the equal subregions and each subregions are divided into equal patches with this algorithm. The FFG masks are used for convolution operation over each patch to produce scalar values. These values from a feature matrix, and the identity of fingers is determined by a norm of the elements of the feature matrices. The distribution of the norms shows conspicuous differences between the pairs of hand images of the same persons and the pairs of the different persons. This is a result to prove the ability of discrimination with the finger face image. An identification rate of 95.0% is obtained as a result of the test in which 500 hand images taken from 100 persons are processed through F-algorithm. It is affirmed that the finger face reveals to be such a good biometrics as other hand parts owing to the ability of discrimination and the identification rate.

• Journal of Wetlands Research
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• v.12 no.3
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• pp.155-163
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• 2010

The flash flood is characterized as flood leading to damage by heavy rainfall occurred in steep slope and impervious area with short duration. Flash flood occurs when rainfall exceeds Flash Flood Guidance(FFG). So, the accurate estimation of FFG will be helpful in flash flood forecasting and warning system. Say, if we can reduce the uncertainty of rainfall-runoff relationship, FFG can be estimated more accurately. However, since the rainfall-runoff models have their own parameter characteristics, the uncertainty of FFG will depend upon the selection of rainfall-runoff model. This study used four rainfall-runoff models of HEC-HMS model, Storage Function model, SSARR model and TANK model for the estimation of models' uncertainties by using Monte Carlo simulation. Then, we derived the confidence limits of rainfall-runoff relationship by four models on 95%-confidence level.

• The Journal of Fisheries Business Administration
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• v.34 no.2
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• pp.27-52
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• 2003

The object of this paper is to review the fisheries subsidies of the major FFG(Fish Friends Group) which argue the elimination and the phasing-out, to compare with Korea's subsidies category and provide the basic information for planning of fisheries subsidies policy and the negotiation strategy in the future. The result from the comparative analysis of the subsidies between the major FFG showed that WWF(World Wildlife Fund) fisheries subsidies categories, with the exception of Marketing and Price Support Program which is similar to Korea in terms of the supporting type and methods, differ from those of Korea. Also, The unique type of WWF Fisheries Subsidies, which is beyond Korea's subsidies, are Direct Payment for Fishermen and Fishery Wokers, Capital ＆ Infrastructure Support, Fishery Management and Protection, etc. In case of capital support and fisheries fuel, the payment method or other institutional backgrounds is somewhat different from each nation. On the base of this analysis, this paper is suggesting the direction of the Korea's Fisheries subsidies policy as follows ; First, developing new policy methods and supporting ways such as Direct Payment for Fisherman is needed. Second, Converting fisheries subsidies category expected to be classified to Red Amber into another type of non-negative subsidies should be carried out, demonstrating that these kinds of subsidies give no negative effect to the environment and the trade, Third, Reviewing the categorize system of Korea's subsidies and revising it according to international trends is necessary as well. In respect to WTO/DDA, the watchful analysis of Korea's fisheries program must be preceding in ahead of making the negotiation strategy. And Korea firstly need to stress the fact that, while the major FFG can directly pay for fisheries section, other nations have no choice but supporting in preferential tax or loan manner. Using this kind of strategy, it is may enlarge the negotiating power in the WTO/DDA to reflect fully Korea's position.

• Ocean and Polar Research
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• v.26 no.2
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• pp.361-365
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• 2004

Deep-sea Resources Research Center (DRRC) has been using a free-fall grab (FFG) for the resource evaluation of polymetallic nodules in the KODOS (Korea Deep Ocean Study) area, NE Pacific, since 1992. A FFG model (Model 4200, Benthos) adapting one glass buoy system (diameter 17 inch, net buoyance 25.4 kg) has been used until 1993. Since then, DRRC has carried out a study to increase the recovery rate of FFG and it was found that a revised system adapting an additional buoy (diameter 10 inch, net buoyance 4.5 kg) gives improved results. The nodule sampling tests were performed using two different models for the same study area and the resulting recovery rates were compared. The result shows no distinct difference in recovery time between two models, but average recovery rate of the revised model was increased to 99.44% from 96.06% of the original model.