• Journal of Korea Water Resources Association
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• v.52 no.spc2
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• pp.765-776
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• 2019

The purpose of this study is to provide the legal and institutional guidelines and standards that can be used in the whole river restoration project and to analyze and evaluate the performance of the river project. We constructed an assessment system of four biological taxa that can represent the river environments, namely, evaluation indexes and standards of vegetation and birds, benthic invertebrates and fishes. Specifically, the assessment indicator and criteria of biological characteristics are summarized, so that in case of vegetation community, vegetation diversity, vegetation complexity, and vegetation naturalness can be quantitatively assessed through the combination of three indices. Based on the scientific basis of the advanced techniques, benthic invertebrates, fishes, and birds were proposed to quantitatively evaluate assessment grades according to the classification of biological data. In order to evaluate biological characteristics, which are a part of river environmental naturalness, we proposed a comprehensive biological index and evaluation grade applying the weight of these four biological taxa, and it clearly reflects the characteristics of river environment in test bed.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.417-418
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• 2018

미국 국립가뭄경감센터 (National Drought Mitigation Center, NDMC)는 다양한 가뭄지수를 통합하여 미국 전역의 가뭄진행상황을 모니터링하고 가뭄대응정책 수립을 위한 주요 의사결정정보로 활용하고 있다. 대표적으로 1999년에 개발되어 현재까지 운영 중인 미국가뭄모니터 (United States Drought Monitor, USDM)는 미국 전역에 대하여 가뭄단계를 표시한 지도 (U.S. Drought Monitor map)를 매주 생성하여 제공하고 있다 (http://droughtmonitor.unl.edu/). 가뭄지표(drought index)는 가뭄의 현황과 시공간적인 전개 과정을 분석하고 정량적 가뭄심도 평가 및 가뭄대응계획 수립을 위한 도구로써 다양하게 개발되어 활용되고 있다. 가뭄의 정도를 정량화하기 위하여 개발된 다수의 가뭄지수는 대상과 평가방법에 따라 가뭄을 표현하는 특성이 서로 다르다. 하나의 가뭄지수로는 가뭄특성을 온전히 표현하기 어렵기 때문에, 최근에는 단일 가뭄지수에 의존하기 보다는 다수의 가뭄지수를 이용하되, 여러 가뭄지수 간의 특징을 고려하여 각 가뭄지수가 갖는 장단점을 상호 보완하여 사용하기를 권고하고 있다. USDM은 파머가뭄심도지수 (Palmer Drought Severity Index, PDSI), Soil Moisture Model (NOAA Climate Prediction Center, CPC), 미 지리조사국의 하천유량 주간보고 (USGS Weekly Streamflow), 표준강수지수 (Standardized Precipitation Index, SPI) 등의 주요 가뭄판단지표를 선정하고, 가뭄판단의 기준으로써 각 가뭄지수의 가뭄심도 (drought severity) 및 백분위수 (percentiles)로 등급을 구분하였다. 가뭄등급은 '정상 상태 (none)'를 포함하여 '비정상적인 건조 (abnormally dry, D0)'에서 최악의 가뭄상태를 의미하는 '이례적인 가뭄상태 (exceptional, D4)'에 이르는 6 단계로 구분하고, 정상상태를 제외한 5 단계의 통합가뭄단계로 표시한다. 우리나라에서는 기상청, 수자원공사, 농어촌공사에서 기상/수문/농업관련 가뭄지수의 위험지도를 실시간으로 제공하고 있으며, 각 지표별로 상이한 기준으로 가뭄을 판단하고 있다. 각각의 가뭄지표에 대한 가뭄판단기준은 해당 국가의 장기적으로 축적된 자료를 활용하여 가뭄단계 및 가뭄판단기준의 재설정에 대한 연구가 필요하다. 본 연구에서는 SPI, SC-PDSI, 표준강수증발산지수 (Standardized Precipitation Evapotranspiration Index, SPEI), Evaporative Demand Drought Index (EDDI), 유효가뭄지수 (Effectvie Drought Index, EDI)의 다양한 가뭄지수를 활용하여 USDM의 가뭄심도 및 가뭄판단기준을 적용하고자한다.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.34 no.5
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• pp.144-155
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• 2022

The Korea Coast Guard evaluates the risk of major coastal activity places to prevent coastal accidents, and patrols and manages them based on that, but it is not responding properly to the continuously increasing number of coastal accidents. The reason for this is that, despite the gradual expansion of coastal activity places, there is a lack of manpower to manage and supervise them, resulting in blind spots in coastal accident safety management. Therefore, in order to solve this problem, it is necessary to prepare more efficient and effective measures that check and supplement the current coastal safety management system. Coastal accidents show different characteristics of accident causes and places due to differences in the activity characteristics of users according to time. As a result of analyzing coastal accident data (2017~2021), the frequency of daytime accidents is high in the case of sea rock, beach, and offshore, where family leisure activities are frequent. In the case of wharf, tidal flat and bridge, where accidents due to drinking, disorientation, and suicide mainly occur, the frequency of accidents at night is high. In addition, there were more accidents on weekends when the number of users increased compared to weekdays. This trend indicates that the user's temporal activity characteristics must be reflected in the risk assessment of coastal activity places. Therefore, in this study, based on the case of coastal accidents, the characteristics of accidents at coastal activity places according to time were identified, and the criteria were presented for risk evaluation by grading them. It is expected that it will be possible to lay the foundation for reducing coastal accidents by efficiently managing and supervising coastal activity places over time using the presented evaluation criteria.

• 한국노년학
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• v.34 no.2
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• pp.369-386
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• 2014

The purpose of this study was to develop the classification of home-based long-term care activities and to test its validity. In this study, the taxonomy of long-term care activities was structured according to the service domain and process. Two expert groups participated in making a draft of the taxonomy that was composed of 7 service domains, 22 care needs, 22 service objectives, and 114 activities. Reliability and validity of the taxonomy was tested in a sample of 152 elderly subjects who used the home-based long-term care services. Based on the factor analysis of 114 activities, 21 factors were extracted from 114 activities. Internal consistency of the factors was high. Content validity was confirmed by the CVI. Long-term care insurance grade was used to assess the criterion validity. Among 21 care needs, 12 cares needs were significantly different from their grade. The classification of home-based long-term care activities demonstrated reliability and validity. In conclusion, the use of this classification is recommended while communicating with the elderly subjects, service providers, and the 3rd party payers.

• Journal of Korea Port Economic Association
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• v.39 no.3
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• pp.179-189
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• 2023

Korea's port development adjusts the completion time and size of port facilities according to the future port throughput. The current port development system, which is referred to as "throughput-linked port development (Trigger Rule)", has received positive evaluation for efficiently executing the limited port development budget. Recently concerns have been growing over deteriorating service levels in port facilities in Korea due to accelerated aging of terminal facilities. However, the current port development system does not possess any standard for assessing the level of service and utilizing development indicators. The purpose of this paper is to calculate the Port Service Index (PSI) by selecting indicators to measure the Level of Service (LOS) of ports and deriving weights between the indicators, so that the current "throughput-linked port development (Trigger Rule)" can be linked with the level of service. Based on the result of analysis on a variety of preceding studies, the ship waiting rate, berth productivity, ship turnaround time and ship productivity were selected as four indicators to constitute the Port Service Index. The AHP and entropy methodologies were used to derive weights for each of four indicators which were later combined to calculate the comprehensive weight. The calculation formula of the Port Service Index (PSI) was derived by using the aggregated weights of each indicator, based on which the LOS of domestic container and bulk terminals were evaluated and this measurement result was divided into 6 classes to define each LOS. This paper contributes to draw the improvement measures for port development system that are able to connect the quantitative indicator of throughput, as well as a qualitative indicator of the level of "service".

• Korean Journal of Agricultural and Forest Meteorology
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• v.18 no.4
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• pp.208-220
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• 2016

Automatic Mountain Meteorology Observation System (AMOS) is an important ingredient for several climatological and forest disaster prediction studies. In this study, we select the optimal sites for AMOS in the mountain areas of Honam and Jeju in order to prevent forest disasters such as forest fires and landslides. So, this study used spatial dataset such as national forest map, forest roads, hiking trails and 30m DEM(Digital Elevation Model) as well as forest risk map(forest fire and landslide), national AWS information to extract optimal site selection of AMOS. Technical methods for optimal site selection of the AMOS was the firstly used multifractal model, IDW interpolation, spatial redundancy for 2.5km AWS buffering analysis, and 200m buffering analysis by using ArcGIS. Secondly, optimal sites selected by spatial analysis were estimated site accessibility, observatory environment of solar power and wireless communication through field survey. The threshold score for the final selection of the sites have to be higher than 70 points in the field assessment. In the result, a total of 159 polygons in national forest map were extracted by the spatial analysis and a total of 64 secondary candidate sites were selected for the ridge and the top of the area using Google Earth. Finally, a total of 26 optimal sites were selected by quantitative assessment based on field survey. Our selection criteria will serve for the establishment of the AMOS network for the best observations of weather conditions in the national forests. The effective observation network may enhance the mountain weather observations, which leads to accurate prediction of forest disasters.

• Journal of Intelligence and Information Systems
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• v.17 no.3
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• pp.25-41
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• 2011

Recently, support vector machines (SVMs) are being recognized as competitive tools as compared with other data mining techniques for solving pattern recognition or classification decision problems. Furthermore, many researches, in particular, have proved them more powerful than traditional artificial neural networks (ANNs) (Amendolia et al., 2003; Huang et al., 2004, Huang et al., 2005; Tay and Cao, 2001; Min and Lee, 2005; Shin et al., 2005; Kim, 2003).The classification decision, such as a binary or multi-class decision problem, used by any classifier, i.e. data mining techniques is so cost-sensitive particularly in financial classification problems such as the credit ratings that if the credit ratings are misclassified, a terrible economic loss for investors or financial decision makers may happen. Therefore, it is necessary to convert the outputs of the classifier into wellcalibrated posterior probabilities-based multiclass credit ratings according to the bankruptcy probabilities. However, SVMs basically do not provide such probabilities. So it required to use any method to create the probabilities (Platt, 1999; Drish, 2001). This paper applied AdaBoost algorithm-based support vector machines (SVMs) into a bankruptcy prediction as a binary classification problem for the IT companies in Korea and then performed the multi-class credit ratings of the companies by making a normal distribution shape of posterior bankruptcy probabilities from the loss functions extracted from the SVMs. Our proposed approach also showed that their methods can minimize the misclassification problems by adjusting the credit grade interval ranges on condition that each credit grade for credit loan borrowers has its own credit risk, i.e. bankruptcy probability.

• Journal of Wetlands Research
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• v.17 no.2
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• pp.184-192
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• 2015

This study is a basic research for low maintenance constructed wetlands which can prevent water quality deterioration due to wetland soils. The purpose of this study is to analyze water quality control mechanisms of constructed wetland on the artificial ground which installed the modular revetment structure(MRS), a device that separates water and soil. This study was then conducted with two different wetland mesocosms (a treatment plot and a control). These mesocosms were monitored to analyze effects of water quality control of the MRS. A treatment plot was built, and separated into soil and water, by filling the MRS with the decomposed granite soil in the mesocosm made of rubber material. A control plot was built where the decomposed granite soils were exposed to water by leaving the soil on the bottom of the mesocosm made of rubber material. Water quality was then analyzed by using Kolmogorov-Smirnov Z examination which then showed that pH, BOD, SS, Chl-a, T-P, T-N had statistically valid difference between a container with the MRS and one without it. According to the analysis of the water quality, the temperature and the EC level came out similarly and both mesocosm showed same level on pH and DO. A treatment plot had higher levels of BOD, SS Chl-a, and T-P. A control plot's T-N value was little lower than that of the treatment plot. This study suggests method of constructed wetlands using the MRS prevents problems occurring in wetland soils: aridity of wetlands by soil erosion, eutrophication, and algal blooms due to nutrients released from wetland soil. These functions of constructed wetland with the MRS increase aesthetic, ecologic, social, and economic value of the wetland. Outcomes of this research will later enable more proficient way of stabilizing water quality and provide data for planning low maintenance constructed wetlands.

• Journal of the Korean Association of Geographic Information Studies
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• v.16 no.3
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• pp.136-146
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• 2013

This study has specified terminology for mountain ridgeline, and organized the present condition of Korean mountain ridgeline and empirical management measures of Beakdudeagan and Jeongmeak. Moreover, based on previously published paper maps, mountain map, and numerical maps, this study has used GIS to reorganize Jeongmaek of Korea, including Hanbukjeongmaek, Hannamjeongmaek, and Gumbukjoengmaek. To ensure accuracy, DEM, Shaded Relief Image, gradient, curvature, and aspect have been analyzed from recent numerical maps. On extraction process, this study analyzes more specifically the results, previous Beakdudaegan is modified and new Jeongmaeks have been extracted. Moreover, for analyzing natural environment of surrounding of major mountain ridgeline, ecological zoning grade of mountain ridgeline is analyzed. With the analyzed result, domestic and foreign mountain ridgeline management policy is suggested, and environmental impact assessment method for major mountain ridgeline development is also suggested. In this study, Baekdudaegan and its Jeongmaek are organized and analyzed. With the results, this study suggested political linkage of mountain ridgelines and guidelines for environmental impact assessment of ridgeline development.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2002.02a
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• pp.438-443
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• 2002

본 연구는 수도작에서 토양과 식물체의 분광반사특성과 영상처리를 이용한 기계시각 잡초검출 센서를 개발하기 위한 기초연구로서 분류하고자 하는 대상체들의 분광반사율을 조사하여 주요한 파장을 선정하고 선정된 파장을 이용한 판별분석을 통해 각 대상체에 대한 분류 정확도를 중심으로 잡초검출 가능성을 조사하기 위하여 수행하였으며, 실험으로부터 얻은 결론은 다음과 같다. 1. 토양과 식물체를 구분하는데 효과적인 파장은 마른 토양의 경우 680 nm, 배수 토양에 있어서는 810 nm로 선정하였고, 토양을 배제한 후 벼와 잡초를 구분하기에 효과적인 파장은 580, 680 nm로 선정하였다. 2. 토양과 식물체를 구분하기 위한 판별분석 결과 2가지 토양상태 모두 식물체와 완전히 구분 가능한 것으로 나타났다. 벼와 잡초를 구분하기 위한 실험에서, 벼는 98%의 분류정확도로 구분이 가능하였고, 잡초는 83%의 분류정확도로 구분이 되는 것으로 나타났다. 따라서 차후 분광학적 원리를 이용한 센서를 제작할 때 본 연구에서 선택한 주요 파장과 판별함수를 이용하여 장치를 구성하고 알고리즘을 제작한다면 벼, 잡초, 토양을 효과적으로 구분이 가능할 것으로 판단되었다. 3. 컬러 CCD 카메라를 사용하는 경우에 있어 식물체와 토양을 구분하기 위해 3 종의 파장 중 630 nm 파장만의 이용을 고려하여 그 분류성능을 분석한 결과, 식물체와 토양은 소수의 관측치를 제외하고 완전히 구분이 가능했고, 벼와 잡초를 구분한 결과에서는 비교적 높은 분류능력을 가진 것으로 나타나 차후 컬러 CCD 카메라를 이용하여 장치를 구성하는데 좋은 기초가 될 것으로 판단된다. 배양체의 접종작업은 모든 배양실이 인력에 의존하였으며, 배양체를 배지와 분리하여 불필요한 부분을 제거하고 배양작물에 따라 생육정도를 2~3등급으로 구분하여 배양용기의 배지 위에 치상하는 과정으로 수행되었으며, 작업능률은 호접란의 경우 배양병에 25본을 접종하는데 시간당 6병, 심비디움은 원형 플라스크에 25본을 접종하는데 시간당 10병 정도였다. 바. 식물체의 대량증식에 사용되는 플라스크, 배양병, PE용기 등 배양용기의 세척작업은 농원의 1개배양실에서 간이식 세척기, 이 외의 9개배양실은 모두 물에 담겨 두었다가 세제와 브러쉬 등을 사용하여 인력으로 세척하고 있어 생력화 기술개발이 요구되었다.도가 빠를수록 건조속도가 빨라졌으며, 건조에너지도 1,334kcal/kg.water로 비슷하게 소요되었다. 마. 시험구와 대비구의 건감률은 시험구에서 1.08~1.36w.b./h로 나타나 대비구보다 약 9.9~18.3%가 높게 나타났고, 건조에너지는 10.2~14.6%가 절감되었다. 발아율은 열풍온도가 낮을수록 높게 나타났고 시험구가 대비구보다 발아율이 낮게 나타났으며, 동할률 증가량도 원적외선.열풍 복합건조방법이 높게 나타나 이것은 곡물 표면에 원적외선 방사에의한 복사열이 전달되어 열장해를 받았기 때문으로 판단되며, 금후 더 연구하여 적정 열풍온도 및 방사체 크기를 구명해야 할 것이다.으로 보여진다 따라서 옻나무 유래 F는 포유동물의 생식기능에 중요하게 작용하는 것으로 사료된다.된다.정량 분석한 결과이다. 시편의 조성은 33.6 at% U, 66.4 at% O의 결과를 얻었다. 산화물 핵연료의 표면 관찰 및 정량 분석 시험시 시편 표면을