• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.20 no.2
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• pp.111-118
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• 2002

These days, surveying instruments are developing rapidly and the precision is improving continuously. The building of three dimensional terrains of high precision are possible and the calculation of the areas or the volumes have high precision due to the development of the technique of the spatial information system using computer. But actually, in construction site they calculate two-dimensional area using the traditional method, plate table surveying, planimeter, and then get three-dimensional area through multiplying two-dimensional area by the slope correction factor. In this study, we show the defect and inefficiency of the calculation of area by the traditional methods and survey the area with Electric Distance Measurement and GPS instrument. With this data, we made the three dimensional terrain model and calculated two-dimensional area, three-dimensional area. After that, we compared areas that calculated by algorithm of triangulated irregular network and analysis of grid method with standard area that calculated by the traditional method. Finally, this paper suggested more effective and precious method in calculating three-dimensional area.

• The Journal of the Convergence on Culture Technology
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• v.9 no.1
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• pp.531-537
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• 2023

Interior construction is required to estimate the quantity of material and the cost expected from 2D drawing in design phase and look for the reasonable method of work. Therefore, exact estimation for quantity and budgeting are very important processes, as a measure of judging the profitability of interior construction. These processes are mostly based on 2D drawing, so time and experienced staff are required. Error and omission can occur because the experienced staff also calculates the area using 2D based drawing. Interior market is currently based on 3D modeling from planning to final design. Accordingly, estimating quantity based on 3D modeling is emerging as a way of reducing error and omission. This paper will present the methodology on calculating area, the basic element of estimating quantity based on 3D Modeling in interior field.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.2
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• pp.324-339
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• 2021

In this study, we determined the correlation between the wave characteristics and the change in the area of Haeundae Beach, conducted regression analysis between the wave characteristics and the change in beach area, and derived a formula for calculating the change in beach area. The change in beach area was calculated by applying the derived formula to wave observation data corresponding to a period of approximately 10 months, and the formula was subsequently validated by comparing the obtained results with the observed area. It is found that the error associated with the formula for calculating the change in beach area ranges from 1.5 m to 2.7 m based on the average beach width, and the correlation coefficient corresponding to the observed area ranges from 0.91 to 0.94. Furthermore, it is observed that the change in beach area is af ected by the wave direction in the western zone, wave height in the central zone, and wave height and wave period in the eastern zone. These results can contribute to understanding the impact of a coastal improvement project on the beach area fluctuation characteristics of Haeundae Beach and the ef ectiveness of such a coastal improvement project. By applying the aforementioned derived formula to highly accurate wave prediction data, the change in beach area can be calculated and incorporated for predicting significant long-term changes in beach areas. Furthermore, such a prediction can be considered as the basis for making decisions while establishing preemptive countermeasure policies to prevent coastal erosion.

• Journal of the Korean Society of Radiology
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• v.11 no.1
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• pp.37-42
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• 2017

We measured the absorbed dose and the area dose using an ionization chamber type of area dose product (DAP) meter and measured the calibration factor in the X-ray examination. In the indirect dose measurement method, the detector was installed in the radiation part of the X-ray equipment, and the measured value was calculated as the dose at the exposure part. The instrument used to calculate the calibration factor was an X-ray equipment (DK-550R / F, DongKang Medical Co., Ltd., Seoul, Korea). The calibration method for the calibration factor was to connect the DAP meter (PD-8100, Toreck Co. Ltd., Japan) to the calibration dosimeter tube voltage of 70 kV, tube current of 500 mA, 0.158 sec. The reference dosimeter used a semiconductor (DOSIMAX plus A, Scanditronix, $Wellh{\ddot{o}}fer$, Germany). After installing the DAP meter on the front of the multi-collimator of the ionization chamber, the calibration factor of the dosimeter was obtained using the reference dosimeter for accurate dose measurement. Experimental exposure values and values from the calibration dosimeter were calculated by multiplying each calibration factor. The calibration factor was calculated as 1.045. In order to calculate the calibration coefficient according to the tube voltage in the ionization type DAP dosimeter, the absorbed dose and the area dose were calculated and the calibration factor was calculated. The corrective area dose was calculated by calculating the calibration factor of the DAP meter.

• Journal of the Korean Association of Geographic Information Studies
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• v.4 no.4
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• pp.61-71
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• 2001

In these days, surveying instruments are developing rapidly and the precision is improving continuously. The reappearance of three dimensional terrains of a great precision are possible and the calculation of the area or the volume has a high precision due to the development of the technique of the spatial information system using computer. But actually, in construction site they calculate two-dimensional area using the traditional method, plane table surveying, planimeter, and then get ground surface area through timing the slope correction factor. In this study, I show the defect and inefficiency of the calculation of the area by the traditional methods and survey the area with Electronic Distance Measuring equipment and GPS instrument. With these data, we made the three dimensional terrain model and calculated two-dimensional area and ground surface area. After that, I compared areas that calculated by algorithm method of irregular triangle and analysis of grid method with standardizing the area that calculated by the traditional method. Finally, I suggested more effective and precise method in calculating ground surface area.

• Korean Journal of Remote Sensing
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• v.34 no.2_2
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• pp.339-349
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• 2018

The massive green tide occurred every summer in the Yellow Sea since 2008, and many studies are being actively conducted to estimate the coverage of green tide through analysis of satellite imagery. However, there is no satellite images selection criterion for accurate coverage calculation of green tide. Therefore, this study aimed to find a suitable satellite image from for the comparison of the green tide coverage according to the spatial resolution of satellite image. In this study, Landsat ETM+, MODIS and GOCI images were used to coverage estimation and its spatial resolution is 30, 250 and 500 m, respectively. Green tide pixels were classified based on the NDVI algorithm, the difference of the green tide coverage was compared with threshold value. In addition, we estimate the proportion of the green tide in one pixel through the Linear Spectral Unmixing (LSU) method, and the effect of the difference of green tide ratio on the coverage calculation were evaluated. The result of green tide coverage from the calculation of the NDVI value, coverage of green tide usually overestimate with decreasing spatial resolution, maximum difference shows 1.5 times. In addition, most of the pixels were included in the group with less than 0.1 (10%) LSU value, and above 0.5 (50%) LSU value accounted for about 2% in all of three images. Even though classified as green tide from the NDVI result, it is considered to be overestimated because it is regarded as the same coverage even if green tide is not 100% filled in one pixel. Mixed-pixel problem seems to be more severe with spatial resolution decreases.

• Proceedings of the Optical Society of Korea Conference
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• 2003.07a
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• pp.278-279
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• 2003

광도의 기본 단위인 칸델라(Candela) 눈금은 물론 복사조도(irradiance), 조명도(illuminance)와 같은 유도 단위를 실현하기 위해서는 검출기의 시야를 한정하는 개구면적의 정밀한 측정이 필요하다. 여기에서는 가장자리의 광학적 검출방법에 의한 개구면적의 산출방식을 소개하고, 가우시안광에 의한 면적 측정법의 측정값과도 비교하여 그 결과를 보여준다. 기존의 개구 면적 측정방식으로 한가지 방법은 탐촉자를 물리적으로 접촉시켜서 개구의 가장자리를 결정하고, 개구의 기하학적 모양을 원으로 가정하여 면적을 산출하는 방식이 있는데, 이 방법을 사용하면 기계적인 접촉에 의하여 칼날과 같았던 개구의 가장자리가 손상을 입게 되기 때문에 측정이 잘못되는 것은 물론이고, 이렇게 측정된 개구를 사용하게되면 손상된 부위에 의한 면적의 변화와 이로 인한 산란이 증가하게 된다. (중략)

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.986-986
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• 2012

최근에 집중 호우, 돌발 강수 등의 국지적인 강수 현상의 발생이 증가하고 있으며, 산악 지역에서의 국지성 강우에 의한 사고 발생이 증가하고 있어 이에 대한 감시가 필요하다. 현재 기상청의 지상관측자료는 약 13 km의 공간해상도로 남한 지역 전체에 대해 제공하고 있으나 북한, 해상, 산악 등의 지역에 대한 감시는 상대적으로 빈약하다. 반면 레이더는 1 km의 고해상도의 공간자료를 산출할 수 있으므로 산악 지역에 대한 분석에 레이더 자료를 활용할 수 있다. 국립기상연구소(National Institute of Meteorological Research; NIMR)는 공간보정 기법을 적용하여 2009년에 대해서 격자($1{\times}1km^2$) 및 유역(117개 중권역, 국토해양부)에 대한 일, 월누적 강수량을 산출하였으며, 지상 우량계 자료와 비교하였다. 2009년 여름철 사례에 대해서 일누적강수량을 분석하였으며, 월누적 강수량의 경우에는 2009년 전체에 대해 지상 우량계의 월누적강수량 자료를 이용하여 MAE, RMSE 등을 산출하여 검증하였다. 본 연구는 레이더 강수량 정보를 활용하여 지상 관측 공백지역의 강수량에 대한 감시를 통해 산악 지역에서 발생하는 사고에 대비하고, 유역별 레이더면적강수량 산출을 통하여 효율적인 물관리를 위한 기본 자료로 사용함으로써 수문 기상 분야에 활용할 수 있을 것으로 사료된다.

• Journal of the Korean earth science society
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• v.41 no.2
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• pp.129-136
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• 2020

Drought is an environmental disaster typically defined as an unusual deficiency of water supply over an extended period. Satellite remote sensing provides an alternative approach to monitoring drought over large areas. In this study, we monitored drought patterns over about 30 years (1985-2015), using satellite imagery of Lake Soyang, Gangwondo, South Korea. Landsat images were classified using ISODATA, maximum likelihood analysis, and an artificial neural network to derive the lake area. In addition, the relationship between areas of Lake Soyang and the Standardized Precipitation Index (SPI) was analyzed. The results showed that the artificial neural network was a better method for determining the area of the lake. Based on the relationship between the SPI value and changes in area, the R² value was 0.52. This means that the area of the lake varied depending on SPI value. This study was able to detect and monitor drought conditions in the Lake Soyang area. The results of this study are used in the development of a regional drought monitoring program.

• Journal of Korean Society of Transportation
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• v.20 no.1
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• pp.149-156
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• 2002

본 연구는 보행자 시설 중 계단과 대기공간에 대해 공학적으로 합리적인 분석방법을 제공하고 이를 통해 안전하고 편리한 보행시설의 제공을 도모하는 것을 목적으로 하였다. 본 연구를 위해 계단과 대기공간에 대한 외국의 조사방법과 분석방법을 참조, 비교하여 서비스 수준 결정기준을 정하고 용량 값을 산출하여 우리나라 현실에 맞는 적정한 설계기준을 산출하기 위해 노력하였다. 계단의 경우 효과척도로 보행 교통량을 그리고 대기공간에 있어서는 1인당 점유면적을 사용하였다. 현장 조사 결과 계단에서의 보행량은 보행자가 군을 형성했을 경우와 그렇지 않은 경우 최대 보행량에 차이가 나는 것을 고려하여 보행자 군의 형성 여부에 따라 서비스 수준의 기준을 다르게 제시하였으며, 대기공간의 경우에는 1인당 점유면적을 한국인의 평균체형을 기준으로 하여 서비스 수준의 기준을 제시하였다. 계단과 대기공간에 있어서 이러한 조사와 분석을 통해 산출된 결과는 외국의 경우와 다른 값을 나타내는데, 계단에 있어서는 실질적으로 이용할 수 있는 유효계단 폭에 따라 최대 보행 교통량의 타이가 크게 나타났으며, 대기공간의 경우에는 한사람이 점유 할 수 있는 용량상태에서의 공간이 0.2$m^2$/인으로 외국의 경우보다 적게 나타난다.