• 한국측량학회지
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• 제36권3호
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• pp.117-126
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• 2018

Due to intelligent transport systems, location-based applications, and augmented reality, demand for image maps and 3D (Three-Dimensional) maps is increasing. As a result, data acquisition using UAV (Unmanned Aerial Vehicles) has flourished in recent years. However, even though orthophoto map production and research using UAVs are flourishing, few studies on 3D modeling have been conducted. In this study, orthophoto and 3D modeling research was performed using various angle images acquired by a UAV. For orthophotos, accuracy was evaluated using a GPS (Global Positioning System) survey that employed VRS (Virtual Reference Station) acquired checkpoints. 3D modeling was evaluated by calculating the RMSE (Root Mean Square Error) of the difference between the outline height values of buildings obtained from the GPS survey to the corresponding 3D modeling height values. The orthophotos satisfied the acceptable accuracy of NGII (National Geographic Information Institute) for a 1/500 scale map from all angles. In the case of 3D modeling, models based on images taken at 45 degrees revealed better accuracy of building outlines than models based on images taken at 30, 60, or 75 degrees. To summarize, it was shown that for orthophotos, the accuracy for 1/500 maps was satisfied at all angles; for 3D modeling, images taken at 45 degrees produced the most accurate models.

• 한국조경학회지
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• 제38권5_2호
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• pp.194-205
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• 2010

To predict urban growth according to changes in landcover, probability factors werecal culated and mapped. Topographic, geographic and social and political factors were used as prediction variables for constructing probability maps of urban growth. Urban growth-related factors included elevation, slope, aspect, distance from road,road ratio, distance from the main city, land cover, environmental rating and legislative rating. Accounting for these factors, probability maps of urban growth were constr uctedusing frequency ratio (FR) and logistic regression (LR) methods and the effectiveness of the results was verified by the relative operating characteristic (ROC). ROC values of the urban growth probability index (UGPI) maps by the FR and LR models were 0.937 and 0.940, respectively. The LR map had a slightly higher ROC value than the FR map, but the numerical difference was slight, with both models showing similar results. The FR model is the simplest tool for probability analysis of urban growth, providing a faster and easier calculation process than other available tools. Additionally, the results can be easily interpreted. In contrast, for the LR model, only a limited amount of input data can be processed by the statistical program and a separate conversion process for input and output data is necessary. In conclusion, although the FR model is the simplest way to analyze the probability of urban growth, the LR model is more appropriate because it allows for quantitative analysis.

• 대기
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• 제27권4호
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• pp.423-433
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• 2017

The spatial and temporal variations in radiative forcing (RF) and mean temperature changes of greenhouse gases (GHGs), such as $CO_2$, $CH_4$, and $N_2O$, were analyzed at urban center (Yeon-dong) and background sites (Gosan) on Jeju Island during 2010~2015, based on a modeling approach (i.e., radiative transfer model). Overall, the RFs and mean temperature changes of $CO_2$ at Yeon-dong during most years (except for 2014) were estimated to be higher than those at Gosan. This might be possibly because of its higher concentrations at Yeon-dong due to relatively large energy consumption and small photosynthesis and also the difference in radiation flux due to the different input condition (e.g., local time and geographic coordinates of solar zenith angle) in the model. The annual mean RFs and temperature changes of $CO_2$ were highest in 2015 ($2.41Wm^{-2}$ and 1.76 K) at Yeon-dong and in 2013 ($2.22Wm^{-2}$ and 1.62 K) at Gosan (except for 2010 and 2011). The maximum monthly/seasonal mean RFs and temperature changes of $CO_2$ occurred in spring (Mar. and/or Apr.) or winter (Jan. and/or Feb.) at the two sites during the study period, whereas the minimum RFs and temperature changes in summer (Jun.-Aug.). In the case of $CH_4$ and $N_2O$, their impacts on the RF and mean temperature changes were very small (an order of magnitude lower) compared to $CO_2$. The spatio-temporal differences in these RF values of GHGs might primarily depend on the atmospheric profile (e.g., ozone profile), surface albedo, local time (or solar zenith angle), as well as their mass concentrations.

• 대한원격탐사학회지
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• 제29권6호
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• pp.621-629
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• 2013

Desertification monitoring as a main portion for understand desertification, have been conducted by many scientists. However, the stage of research remains still in the level of comparison of the past and current situation. In other words, monitoring need to focus on finding methods of how to take precautions against desertification. In this study, Vegetation Temperature Condition Index (VTCI), derived from Normalized Difference Vegetation Index (NDVI) and Land Surface Temperature (LST), was utilized to observe the distribution change of vegetation. The index can be used to monitor drought occurrences at a regional level for a special period of a year, and it can also be used to study the spatial distribution of drought within the region. Techniques of remote sensing and Geographic Information System (GIS) were combined to detect the distribution change of vegetation with VTCI. As a result, assuming that the moisture condition is the only main factor that affects desertification, we found that the distribution of vegetation in Bulgan, Mongolia could be predicted in a certain degree, using VTCI. Although desertification is a complicated process and many factors could affect the result. This study is helpful to provide a strategic guidance for combating desertification and allocating the use of the labor force.

• 한국측량학회지
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• 제23권1호
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• pp.31-38
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• 2005

국가 기반시설로서의 도로의 중요성은 상당한 비중을 차지하고 있다. 이에 따른 도로의 신설과 유지관리 비용은 지속적으로 증가하고 있다. 이와 같은 도로관리에 대한 비용 문제를 해결하기 위해서는 기본지리정보를 통한 합리적이고 효율적인 데이터관리가 필요하다. 그러나 현재까지의 기본지리정보 연구는 각 기관별 항목중심으로 연구되어 많은 양의 데이터가 중복구축 되었다. 이에 따라 국토지리정보원에서는 국제표준에 맞는 기본지리정보 지침안을 제시하였다. 본 연구는 동일한 데이터 가공에 대한 비용과 반복구축에 대한 비효율성을 방지하기 위하여 교통분야 기본지리정보를 적용한 도로관리 데이터모델을 제시하였다. 또한 위의 기본지리정보에 의해서 데이터모델을 개발한 사례가 많지 않다. 그렇기 때문에 기본지리정보 데이터모델 지침안이 실제 주제별 데이터모델 구축시 클래스, 속성, 관계 등이 실제 적용하기에 적절한지 고찰하였고 도로관리 데이터모델 실제 적용하였다.

• 한국측량학회지
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• 제23권3호
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• pp.273-282
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• 2005

인공위성기술의 비약적인 발전은 각종 공간정보의 취득과 이를 응용하는 다양한분야에 광범위하게 이용되고 있다. 특히 GPS를 이용한 위치결정은 국가 기준계가 세계좌표계로 전환되는 시점을 맞이하여 더욱 활성화 될 전망이다. 현재 국토지리 정보원에서 발급하는 삼각점에 대한 성과는 신성과와 구성과로 구분하고 있고 2007년부터는 전면 세계좌표계로 전환할 예정에 있다. 현재 제주지역의 삼각점은 최초, 복구 또는 재설한 삼각점 성과 차이로 인해 측량자 들이 그 성과를 이용함에 있어 많은 혼란을 초래하고 있다. 따라서 본 연구는 제주지역의 현행삼각점간 부합관계를 점검하기 위해 1, 2등 삼각점을 기준으로 최초 측량 당시의 측지망을 재 구성하여 GPS 관측을 수행하였다. 관측 후 성과분석을 통해 삼각점간 부합되는 안정점을 추출하고 제주지역에 적합한 측지기준망을 구축하고 그 활용방안을 제시하였다. .

• Architectural research
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• 제9권2호
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• pp.27-35
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• 2007

Our nation has a problem with discrimination of income distribution and inefficient of resources distribution caused by real estate price rising from a sudden economy growth and industrialization. Specially, in recent years, there is a great disparity of apartment price between the north and south of the Han river. Because the housing price is decided by the immanent value of a house and neighborhood effects of the regional where the house is situated, the housing price is occurred difference. The purpose of study was to analyze the influence of various factors of housing price. Also, this study tried to predict real estate market and to establish previous effective real estate policy. In this study, we analyzed the differences of housing price determinants about apartment developments between the north and south of the Han river, and found the important factors that affect the housing price using Structural Equation Modeling(SEM). As a result of this study, the older the buildings are, the more the housing price and the housing price rising ratio have increased, in Gang Nam area. This reason is that these have large possibility to be reconstructed and many convenient facilities, in this area. In the case of Kang Buk area, the increase rate of housing price are so low that they couldn't take effect on the housing price and they were declined. So to speak, constructing the infrastructure which takes effect on the increase rate of housing price is very urgent.

• 한국관개배수논문집
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• 제18권2호
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• pp.87-100
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• 2011

This study is to delineate the watershed hydrological parameters such as area, slope, rain gauge weight, NRCS-CN and time of concentration (Tc) by using the Geographic Information Sytem (GIS) technique, and estimation of design flood for an ungauged watershed. Especially, we attempted to determine the Tc of ungauged watershed and develop simple program using the cell-based algorithm to calculates upstream or downstream flow time along a flow path for each cell. For a $19km^2$ watershed of tributary of Nakdong river (Seupmoon), the parameters including flow direction, flow accumulation, watershed boundary, stream network and Tc map were extracted from 30m Agreeburn DEM (Digital Elevation Model) and landcover map. And NRCS-CN was extracted from 30m landcover map and soil map. Design rainfall estimation for two rainfall gauge which are Sunsan and Jangcheon using FARD2006 that developed by National Institute for Disaster Prevention (NIDP). Using the parameters as input data of HEC-l model, the design flood was estimated by applying Clark unit hydrograph method. The results showed that the design flood of 50 year frequency of this study was $8m^3/sec$ less than that of the previous fundamental plan in 1994. The value difference came from the different application of watershed parameter, different rainfall distribution (Huff quartile vs. Mononobe) and critical durations. We could infer that the GIS-based parameter preparation is more reasonable than the previous hand-made extraction of watershed parameters.

• 한국항행학회논문지
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• 제21권6호
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• pp.572-578
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• 2017

최근 동적 사용자의 정밀위치 요구가 높아지면서, Network RTK(real time Kinematics)를 동적사용자에게 적용하는 방안 연구가 활발히 진행되고 있다. Network RTK는 다수의 기준국 반송파 측정치를 활용해 약 50-70km 영역에 정밀위치를 제공하는 시스템이다. 이러한 Network RTK 보정정보를 제공하는 다수의 클러스터를 하나의 시스템으로 구성하면, 보다 넓은 영역의 동적 사용자에게 정밀위치를 제공할 수 있다. 본 논문은 다중 클러스터를 전국으로 확장하는 경우 효율적으로 운용하는 방안에 대해 연구했다. 다중 클러스터 시스템의 구성에 따른 계산량을 분석하고, 효율적인 운용을 위해 주 수신국 운용 방안 및 시스템 인프라 구성 방안을 제안했다. 또한 각 제안한 방안에 따른 효과를 분석하고자, 국토지리정보원의 기준국을 활용해 71개의 클러스터를 구성하여, 시뮬레이션을 수행했다. 시뮬레이션 결과 주 수신국 운용 방안에 따라 시스템 계산량은 66 % 감소하고, 시스템 구성에 따라 시스템 구성비용을 90 % 절감할 수 있었다.

• 한국잡초학회지
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• 제18권4호
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• pp.364-370
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• 1998

1981 및 1992년도 우리 나라 논잡초 조사자료를 이용한 생태학적 종합우점도 분석과 GIS에 의한 분석결과에 대한 요약을 하여 보면 다음과 같다. 1. 1981년 생태학적 종합우점도 분석에 의하여 가장 우점도가 높았던 잡초는 물달개비이었으며, 이는 전국적인 논에 걸쳐 가장 발생밀도가 높은 것으로 이해되지만 GIS분석에 의한 전국지역에 걸친 발생밀도는 이와 큰 차이가 나타났다. 2. 1981년 GIS분석에 의한 일년생 광엽잡초 물달개비의 발생우점 지역으로서는 경기의 시흥, 여주지역, 충남의 당진, 예산, 아산, 공주, 청양, 부여, 논산, 천안, 금산 등이었으며, 경북지방은 점촌, 청도, 영천, 봉화, 영풍 등이 상대적으로 매우 높은 발생량을 보였다. 3. 1992년 우점도가 가장 높았던 잡초는 다년생 사초과 잡초인 올방개이었으며. GIS분석에 의한 지역별 발생밀도는 현저한 차이를 보였으며, 주로 경기남부지역과 충남 중 서부지역, 전남 남 서부지역 등이 상대적으로 발생밀도가 높았다. 4. 1992년 올방개 발생이 극심한 지역은 경기 용인, 안성, 화성, 평택, 이천, 여주 일원과 충남의 서산, 당진, 태안, 천안, 공주, 아산, 청양, 예산, 대전일원, 전북의 장수, 전남의 무안, 나주, 해남 등으로 나타났다.