• Korean Journal of Agricultural and Forest Meteorology
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• v.15 no.4
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• pp.320-331
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• 2013

The National Center for AgroMeteorology (NCAM) has designed a risk management solution for individual farms threatened by the climate change and variability. The new service produces weather risk indices tailored to the crop species and phenology by using site-specific weather forecasts and analysis derived from digital products of the Korea Meteorological Administration (KMA). If the risk is high enough to cause any damage to the crops, agrometeorological warnings or watches are delivered to the growers' cellular phones with relevant countermeasures to help protect their crops against the potential damage. Core techniques such as scaling down of weather data to individual farm level and the crop specific risk assessment for operational service were developed and integrated into a cloud based service system. The system was employed and implemented in a rural catchment of 50 $km^2$ with diverse agricultural activities and 230 volunteer farmers are participating in this project to get the user-specific weather information from and to feed their evaluations back to NCAM. The experience obtained through this project will be useful in planning and developing the nation-wide early warning service in agricultural sector exposed to the climate and weather extremes under climate change and climate variability.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.36 no.2
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• pp.105-112
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• 2018

To determine the position of receiver, the GPS (Global Positioning System) uses position information of satellites and pseudo ranges based on signals. These are reflected by surrounding structures and multipath errors occur. This paper proposes a method for multipath error reduction using digital images to enhance the accuracy. The goal of the study is to calculate the shielding environment of receiver using image processing and apply it to GPS positioning. The proposed method, firstly, performs a preprocessing to reduce the effect of noise on images. Next, it uses hough transform to detect the outline of building roofs and determines mask angles and permissible azimuth range. Then, it classifies the satellites according to the condition using the image processing results. Finally, base on point positioning, it computes the receiver position by applying a weight model that assigns different weights to the classified satellites. We confirmed that the RMSE (Root Mean Square Error) was reduced by 2.29m in the horizontal direction and by 15.62m in the vertical direction. This paper showed the potential for the hybrid of GPS positioning and image processing technology.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2004.11a
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• pp.31-35
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• 2004

정보통신 기술의 발달과 디지털 방송의 시작, 뉴미디어의 출현으로 인한 통신과 방송의 융합은 가속화되고 있다. 또한 2010년까지 광대역통신망 BcN과 홈네트워크 구축을 위한 정부정책이 실행 중에 있다. 100Mbps의 전송속도를 구현해야 하는 광대역 통신망(BcN)을 위해 기존 인터넷 백본 1)망은 잘 구축이 되어 있으나 가입자까지의 망 구조에 많은 문제점을 앉고 있다. 기존 전화국을 이용한 XDSL과 지역 SO를 활용한 Cable Modem의 경우 병목현상과 이론상 속도 또한 BcN과 통방통합이 요구하는 50-100Mhz의 전송속도를 만족하지 못한다. 새로운 망 구조를 구축하기 위해 많은 비용과 시간의 소요가 예상된다 가입자 망 구축에 따른 많은 방법과 이론이 제시되고 있다. 똔 논문에선 지역 SO를 활용하여 가입자까지 망을 통방통합과 BcN에 적합한 가입자 망을 새롭게 구성하는 것을 목표로 한다. 먼저 지역 50의 망을 활용하기 위해선 기존 KT와 파워콤의 COF(Glass Optical Fiber)망과 지역 케이블 SO의 HFC 망을 이용하기에는 동축케이블 망의 물리적 특성에 따른 한계로 통방통합과 BcN에 부적합하다. Tree And Branch 구조의 HFC망 대신 $SMF^{2)}$의 기존 SO의 자가망을 새롭게 설계하고 광분배망 기술인 $E-PON^{3)}$방식을 접목시켜 최대한 동축망을 사용하지 않고 굴곡 특성에 약한 $FOG^{4)}$의 특성을 극복하기 위해 $POF^{5)}$망을 이용하여 댁내 홈게이트웨이까지 연결하는 방식으로 지역 SO를 거점으로 활용하여 댁내까지 FHHT와 홈 네트워크까지의 가입자 망을 새롭게 구성하고자 한다. 저장의 효율성을 위해 이진 포멧인 IPMP화된 MP4 파일을 생성할 수 있다.으로써, 에러 이미지가 가지고 있는 엔트로피에 좀 근접하게 코딩을 할 수 있게 되었다. 이 방법은 실제로 Arithmetic Coder를 이용하는 다른 압축 방법에 그리고 적용할 수 있다. 실험 결과 압축효율은 JPEG-LS보다 약 $5\%$의 압축 성능 개선이 있었으며, CALIC과는 대등한 압축률을 보이며, 부호화/복호화 속도는 CALIC보다 우수한 것으로 나타났다.우 $23.87\%$($18.00\~30.91\%$), 갑폭 $23.99\%$($17.82\~30.48\%$), 체중 $91.51\%$($58.86\~129.14\%$)이였으며 성장율은 사육 온도구간별 차는 없었다.20 km 까지의 지점들(지점 2에서 지점 6)에서 매우 높은 값을 보이며 이는 조석작용으로 해수와 담수가 강제혼합되면서 표층퇴적물이 재부유하기 때문이라고 판단된다. 영양염류는 월별로 다소의 차이는 있으나, 대체적으로 지점 1과 2에서 가장 낮고, 상류로 갈수록 점차 증가하며 지점 7 상류역이 하류역에 비해 높은 농도이다. 월별로는 7월에 규산염, 용존무기태질소 및 암모니아의 농도가 가장 높은 반면에 용존산소포화도는 가장 낮다. 그러나 지점 14 상류역에서는 5월에 측정한 용존무기태질소, 암모니아, 인산염 및 COD 값이 7월보다 다소 높거나 비슷하다. 한편 영양염류와 COD값은 대체적으로 8월에 가장 낮으나 용존산소포화도는 가장 높다.출조건은 $100^{\circ}C$에서 1분간의 고온단시간 추출이 적합하였다. 증가를 나타내었는데

• Economic and Environmental Geology
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• v.48 no.5
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• pp.391-400
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• 2015

Korea is a global steel producer and a major consumer while iron ore producing is very low compared to the demand. On the other hand, North Korea holds tremendous amount of iron reserves and, however, its producing rate is limited. Moreover, the data regarding mineral resources of North Korea is very limited and uncertain because of political isolation. This study estimated the amount of iron ore resource and production amount for the Musan Iron mine, the world-known open-pit mine of North Korea, using satellite imagery(Landsat MSS, ASTER) and digital maps between 1976 to 2007. As a result, the mining area of Musan mine was increased by $6.1km^2$ during the 30 years and the mining sector was estimated as $4.9km^2$. We estimated the iron resources and production amount of 0.7 and 0.2 billion metric tons, respectively based on 3D modeling and average iron ore density of Anshan formation in China. This amount indicates 8.1 million tons of annual average production and it coincides well with previous reports. We expect this study would be utilized significantly on inter-Korean exchange programs by providing trustable preliminary data.

• Journal of Environmental Impact Assessment
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• v.15 no.1
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• pp.53-65
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• 2006

Topographic condition is one of the most important things in farming activities. The topographic condition didn't matter for farming in the past because agricultural products had competitive power in the market. So farmers tried to extend their farms without any concern of topographic condition. We need less labor-consuming farming as industrial structure has been changed and the competitive power of the farming has been getting weak. This study analyzed the fallow potential in agricultural area by topographic condition so that we have got results as follows. Maps of elevation, slope, distance from roads and water resources were made for getting a fallow probability model in farms, and these 4 factors were used as independent variables while a variable on whether it is fallow or not is a dependent variable in logistic regression model. In an analysis of the fallow potential depending on farm land types, the fallow probability in fallow orchard showed the highest value of farm lands, 0.973. Cultivated orchard had 0.730 and upland had 0.616 of the fallow probability. The fields having high fallow potential had high elevation, steep slope, and long distance from water resources and roads. Especially, fields having a probability over 0.99 appeared in orchards, fallow uplands and single cropping uplands, which were recognized to have several disadvantages related to the fallow like as high elevation, steep slope, and long distance from water resources and roads. With the logistic analysis, the suitable farm lands appeared at 16.45m of the mean elevation, 1.89 degree of the mean slope, 39.91m of the average distance from water resources, and 32.39m of the average distance from roads. On the contrary, non-suitable land appeared at 114.7m of the mean elevation, 24.9 degree of the mean slope. The distance from roads was more important variable than the distance from water resources for analyzing suitable farm land.

• Journal of Environmental Impact Assessment
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• v.15 no.1
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• pp.1-12
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• 2006

Changes in the soil physical property and the topographic condition derived from agricultural activities like as farming activities, land clearance and cutting down resulted in environmental and economic problems including the outflow of nutrient from farms and the water pollution. Several theories on the soil conservation have been developed and reviewed to protect soil erosion in the regions having a high risk of erosion. This study was done using the USLE model developed by Wischmeier and Smith (1978), and model for the slope length and steepness made by Desmet and Govers (1996), and Nearing (1997) to evaluate the potential of the soil erodibility. Therefore, several results were obtained as follows. First, factors affecting the soil erosion based on the USLE could be extracted to examine the erosion potential in farms. Soil erodibility (K), slope length (L), and slope steepness (S) were used as main factors in the USLE in consideration of the soil, not by the land use or land cover. Second, the soil erodibility increased in paddy soils where it is low in soil content, and the very fine sandy loam exists. Analysis of the slope length showed that the value of a flat ground was 1, and the maximum value was 9.17 appearing on the steep mountain. Soil erodibility showed positive relationship to a slope. Third, the potential soil erodibility index (PSEI) showed that it is high in the PSEI of the areas of steep upland and orchard on the slope of mountainous region around Dokjigol mountain, Dunji mountain, and Deummit mountain. And the PSEI in the same land cover was different depending on the slope rather than on the physical properties in soil. Forth, the analysis of land suitability in soil erosion explained that study area had 3,672.35ha showing the suitable land, 390.88ha for the proper land, and 216.54ha for the unsuitable land. For unsuitable land, 8.71ha and 6.29ha were shown in fallow uplands and single cropping uplands, respectively.

• Journal of the Korean Society of Food Culture
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• v.34 no.6
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• pp.707-718
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• 2019

This study assessed the nutrient consumption of children from lunch at day care centers and kindergartens. A total of 184 lunch plates were selected in two child day care centers and two kindergartens in Seoul. Weights of the menus in planned meals were measured and amount of served and consumed lunches were calculated using a digital photography technique. Nutrients of the planned, served, and consumed lunches were assessed using CAN-Pro 4.0 and the Index of Nutritional Quality (INQ) was calculated for each meal. Compared with the estimated energy requirement for lunch for 3-5 year old children, the planned meals of the child day care centers and kindergartens contributed 42.8% and 98.8% of the daily energy requirements, respectively. At a child day care center, a served meal provided more nutrients than a planned meal since some children requested more servings after eating the served meals. This showed that the planned meal did not meet children's needs as well as the nutrient requirements. At the other child care center, children were served less than the planned meal by 6.8%, which resulted in serving less energy, calcium, potassium, and vitamin C than the required nutrients for lunch. Kindergarten A served meals with the energy requirement for lunch of 101.8%, but Kindergarten B served a meal with the energy requirement of 83.5%. Since the served portions were too small to meet nutrient requirements of the children, they consumed almost all the food served, and their nutrient consumption was similar to the nutrients served. Even though they consumed all the food served, their nutrient consumption did not meet their nutritional requirements. When assessed by INQ, the quality of the meal was good; children could consume enough nutrients when served proper quantity. Teachers who are responsible for serving meals need to be educated on proper portion sizes and how to encourage children to practice healthy eating. To promote healthy eating among children, parents need to provide children with messages consistent with what they have learned at institutions and to be a good role model in daily dietary life.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.34 no.1
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• pp.53-62
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• 2016

In recent years, UAV Photogrammetry based on an ultra-light UAS(Unmanned Aerial System) installed with a low-cost compact navigation device and a camera has attracted great attention through fast and accurate acquirement of geo-spatial data. In particular, UAV Photogrammetry do gradually replace the traditional aerial photogrammetry because it is able to produce DEMs(Digital Elevation Models) and Orthophotos rapidly owing to large amounts of high resolution image collection by a low-cost camera and image processing software combined with computer vision technique. With these advantages, UAV-Photogrammetry has therefore been applying to a large scale mapping and cadastral surveying that require accurate position information. This paper presents experimental results of an accuracy performance test with images of 4cm GSD from a fixed wing UAS to demarcate parcel boundaries in agricultural area. Consequently, the accuracy of boundary point extracted from UAS orthoimage has shown less than 8cm compared with that of terrestrial cadastral surveying. This means that UAV images satisfy the tolerance limit of distance error in cadastral surveying for the scale of 1: 500. And also, the area deviation is negligible small, about 0.2%(3.3m²), against true area of 1,969m² by cadastral surveying. UAV-Photogrammetry is therefore as a promising technology to demarcate parcel boundaries.

• Journal of Korean Society for Geospatial Information Science
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• v.23 no.1
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• pp.89-99
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• 2015

Recently, our construction industry is actively participating in numerous city planning projects in the third world countries. Considering the current depression of domestic real estate market, the emerging foreign demands could certainly provide substantial opportunities for the domestic industry to overcome the trough. For the field planners dealing with such foreign projects, though, the immediate problem is the lack of public statistics and geographic information to perform spatial analyses and/or prepare master plans. This study, in this context, tries to simulate a process to construct a digitized basemap of the case area, 'Bab Ezzouar,' in Algeria of Northern Africa. The area is a typical municipality that lacks the IT databases. To overcome the data shortage, the study uses the satellite map tiles so as to digitize the roads and building structures. It then estimates the block-wise populations based on the building image interpolation as well as the supplementary field survey data. The topographic TINs are also built by the SRTM (Shuttle Radar Topography Mission) digital elevation maps so that the three-dimensional configuration of the structures and terrains are rendered to check the urban scenery and skylines.

• Korean Journal of Agricultural and Forest Meteorology
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• v.21 no.4
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• pp.221-228
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• 2019

The effects of wind speed on the temperature change during day time could be insignificant in a region with a complex terrain. The objective of this study was to derive empirical relationship between solar radiation and hourly temperature under a windy condition for the period from sunrise to sunset in order to improve hourly air temperature at a site-specific scale. The deviation of the temperature measurements was analyzed along with the changes of the hourly sunlight at weather observation sites located on the east and west slopes under given wind speed. An empirical model where wind speed use used as an independent variable was obtained to quantify the solar effects on the temperature change (MJ/㎡). This model was verified estimating the hourly temperature during the daytime (0600-1900 h) at 25 weather observation sites located in the study area that has complex topography for the period from January to December 2018. The mean error (ME) and root mean square error (RMSE)of the estimated and measured values ranged from -0.98 to 0.67 ℃, and from 0.95 to 2.04 ℃, respectively. The daytime temperature at 1500 h were estimated using new and previous models. It was found that to the model proposed in the present study reduced the measurement errors of the hourly temperature in the afternoon in comparison with the previous model. For example, the ME and RMSE of the previous model were (ME -0.91 ℃ and 1.47 ℃, respectively. In contrast, the values of ME and RMSE were -0.45 ℃ and 1.22 ℃ for the new model, respectively. Our results suggested that the reliability of hourly temperature estimates at a specific site could be improved taking into account the effect of wind as well as solar radiation.