• Title/Summary/Keyword: Terrain Data

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Optimization of Air Quality Monitoring Networks in Busan Using a GIS-based Decision Support System (GIS기반 의사결정지원시스템을 이용한 부산 대기질 측정망의 최적화)

  • Yoo, Eun-Chul;Park, Ok-Hyun
    • Journal of Korean Society for Atmospheric Environment
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    • v.23 no.5
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    • pp.526-538
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    • 2007
  • Since air quality monitoring data sets are important base for developing of air quality management strategies including policy making and policy performance assessment, the environmental protection authorities need to organize and operate monitoring network properly. Air quality monitoring network of Busan, consisting of 18 stations, was allocated under unscientific and irrational principles. Thus the current state of air quality monitoring networks was reassessed the effect and appropriateness of monitoring objectives such as population protection and sources surveillance. In the process of the reassessment, a GIS-based decision support system was constructed and used to simulate air quality over complex terrain and to conduct optimization analysis for air quality monitoring network with multi-objective. The maximization of protection capability for population appears to be the most effective and principal objective among various objectives. The relocation of current monitoring stations through optimization analysis of multi-objective appears to be better than the network building for maximization of population protection capability. The decision support system developed in this study on the basis of GIS-based database appear to be useful for the environmental protection authorities to plan and manage air quality monitoring network over complex terrain.

An Analysis on the change in Topography in the West Coast Using Landsat Image (Landsat 영상을 이용한 서해안 지형 변화 추이 분석)

  • 강준묵;윤희천;강영미
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2004.11a
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    • pp.275-279
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    • 2004
  • This study was done to detect the topographic and terrain change of the vicinity of the west coast. To make the basic map of the change in topology and terrain, the mosaic images were made using the images from the satellite, which were given the geometric correction based on the GCP (Ground Control Point) and DEM (Digital Elenation Model) data. The accuracy of the images was examined by .empaling them with CCP through 1:25,000's digital map. After that, among the resultant images of the 1970s and 2000s, those of Sihwa, Hwaong and Ansan, the lands reclaimed by drainage were compared to observe the change in the area. From this study, the accuracy of the images of the west coast from satellite could be acquired and the change of the topology and terrain was detected effectively. From the results, it was known that, in case of the land the topological change was not so big due to the development in the reclaimed land or the bare land. In Sihwa, the size of the land was increased 180 $\textrm{km}^2$ and that of the seashore was decreased 110 km. in Hwaong the size was increased 50 $\textrm{km}^2$ and in Ansan the city space was increased 71 $\textrm{km}^2$ due to the formation of the industrial complex.

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Development of an Effective Walking System for a Hexapod Robot on Uneven Terrain (오프로드 환경에서 효율적인 6족 로봇 보행 시스템 개발)

  • Kim, Jun Woo;Lee, Gi Won;Lee, Suk Gyu
    • Journal of Institute of Control, Robotics and Systems
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    • v.19 no.12
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    • pp.1152-1159
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    • 2013
  • This paper proposes an effective walking system for a hexapod robot on uneven terrain. To overcome the deficiencies of two-pair walking systems, which are effective on even terrain, the use of only three legs changes the steps required for movement. The proposed system receives feedback data from switches attached to the bottom of the legs and gyro sensor to carry out stable walking using the Bezier curve algorithm. From the coordinates of the Bezier curve, which guarantees the circular motion of legs, the motor's angle value can be obtained using inverse kinematics. The angle values are sent to each motor though RS-485 communication. If a switch is pushed by the surface during navigation in the Bezier curve pattern, the robot is designed to change its circular course. Through the changed course, each leg can be located on an optimal surface and the wobble phenomenon is reduced by using a normal vector algorithm. The simulation and experiment results show the efficiency of the proposed algorithm.

A Study on the Technology Development and Application Plan for Making an Integrated Digital Map of an Electronical Navigational Chart and a Digital Terrain Map (육.해도 통합수치도 제작 기술 개발과 응용 방안)

  • 이기철;박창호;서상현;김정희;정희균
    • Journal of Korean Port Research
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    • v.14 no.2
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    • pp.209-217
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    • 2000
  • This study is to develop the technology and the ways of the practical use of the integrated digital map of and Electronical Navigational Chart(ENC) and Digital Terrain Map(DTM) for the effective and scientific based conservation, development and management. In this study, as preliminary studies to make eventual integrated maps, the concept of coastal areas are defined and the characteristics of digital maps developed by Korean Geography Institute and National Marine Investigation Institute are carefully analyzed. A test coastal map was developed based on the integrated digital map, a high resolution satellite image and Global Positioning System. Results from the edge matching analysis of coastal lines shows 8 meters difference in maximum. The problems, causes and solutions for the edge matched differences are described. Furthermore, the practical value of utilization, future use and various field of application are described based on the integrated digital map data base of coastal area.

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A Study on the Technology Development and Application Plan for making an Integrated Digital Map of an Electronical Navigational Chart and a Digital Terrain Map (육.해도 통합수치도 제작 기술 개발과 응용 방안+)

  • 이기철;정희균;박창호;서상현;김정희
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 1999.10a
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    • pp.347-356
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    • 1999
  • This study is to develop the technology and the ways of the practical use of the integrated digital map of and Electronical Navigational Chart(ENC) and Digital Terrain Map(DTM) for the effective and scientific based conservation, development and management. In this study, as preliminary studies to make eventual integrated maps, the concept of coastal areas are defined and the characteristics of digital maps developed by Korean Geography Institute and National Marine Investigation Institute are carefully analyzed. A test coastal map was developed based on the integrated digital map, a high resolution satellite image and Global Positioning System. Results from the edge matching analysis of coastal lines shows 8 meters difference in maximum. The problems, causes and solutions for the edge matched differences are described. Furthermore, the practical value of utilization, future use and various field of application are described based on the integrated digital map data base of coast area.

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Geospatial analysis of wind velocity to determine wind loading on transmission tower

  • Hamzah, Nur H.;Usman, Fathoni
    • Wind and Structures
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    • v.28 no.6
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    • pp.381-388
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    • 2019
  • This paper described the application of Geospatial Analysis in determining mean wind speed, $V_h$ for wind load calculation imposed to electrical transmission tower structural design. The basic wind speed data on available station obtained from Malaysian Meteorology Department is adjusted by considering terrain and ground roughness factor. The correlation between basic wind speed, terrain factor and ground roughness stated in EN-50341-1 is used to obtain the $V_h$ for overhead transmission line elements 50 m above ground. Terrain factor, $k_r$ and ground roughness, $z_0$ in this study are presented by land use types of study area. Wind load is then calculated by using equation stated in design code EN-50341-1 by using the adjusted mean wind speed. Scatter plots of $V_h$ for different $k_r$and $z_0$ are presented in this paper to see the effect of these parameters to the value of $V_h$. Geospatial analysis is used to represent the model of $V_h$. This model can be used to determine possible area that will subject to wind load which severe to the stability of transmission tower and transmission line.

Generation of 3-Dimensional Landscape Map from Aerial Photos (항공사진을 이용한 3차원 경관도 제작)

  • Yeu, Bock-Mo;Jeong, Soo;Kim, Won-Dae
    • Journal of Korean Society for Geospatial Information Science
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    • v.3 no.1 s.5
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    • pp.105-113
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    • 1995
  • Three-dimensional landscape map is very useful in terrain analysis as it looks like real shape of terrain. When three-dimensional landscape map is needed, landscape photos achieved at a position of high elevation or by airplane are generally used. But, this approach can not fully satisfy the user's need to get pictures from various view points. In addition, because photos have some geometric displacement caused by the principle of central projection of camera, it is hard to get accurate locations from the photo. This paper aims to get three-dimensional landscape map similar to real terrain feature from vertical stereo aerial photos by digital photogrammetric techniques. This approach can provide a very useful data for three-dimensional terrain analysis as a function of Geo-Spatial Information System.

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Improvement of Atmospheric Dispersion Model Performance by Pretreatment of Dispersion Coefficients (분산계수의 전처리에 의한 대기분산모델 성능의 개선)

  • Park, Ok-Hyun;Kim, Gyung-Soo
    • Journal of Korean Society for Atmospheric Environment
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    • v.23 no.4
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    • pp.449-456
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    • 2007
  • Dispersion coefficient preprocessing schemes have been examined to improve plume dispersion model performance in complex coastal areas. The performances of various schemes for constructing the sigma correction order were evaluated through estimations of statistical measures, such as bias, gross error, R, FB, NMSE, within FAC2, MG, VG, IOA, UAPC and MRE. This was undertaken for the results of dispersion modeling, which applied each scheme. Environmental factors such as sampling time, surface roughness, plume rising, plume height and terrain rolling were considered in this study. Gaussian plume dispersion model was used to calculate 1 hr $SO_2$ concentration 4 km downwind from a power plant in Boryeung coastal area. Here, measured data for January to December of 2002 were obtained so that modelling results could be compared. To compare the performances between various schemes, integrated scores of statistical measures were obtained by giving weights for each measure and then summing each score. This was done because each statistical measure has its own function and criteria; as a result, no measure can be taken as a sole index indicative of the performance level for each modeling scheme. The best preprocessing scheme was discerned using the step-wise method. The most significant factor influencing the magnitude of real dispersion coefficients appeared to be sampling time. A second significant factor appeared to be surface roughness, with the rolling terrain being the least significant for elevated sources in a gently rolling terrain. The best sequence of correcting the sigma from P-G scheme was found to be the combination of (1) sampling time, (2) surface roughness, (3) plume rising, (4) plume height, and (5) terrain rolling.

A Study on Geoid Height of Provinces in South Korea by Terrain correction of Earth Gravitational Models (EGMs의 지형보정에 따른 국내 지역별 지오이드고 연구)

  • Lee, yong-chang
    • Proceedings of the Korea Contents Association Conference
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    • 2007.11a
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    • pp.942-946
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    • 2007
  • The new gravity field combination models are expected to improve the knowledge of the Earth's global gravity field. This study evaluates six global gravity field models derived from gravimetry and altimetry surface data in a comparison with ground truth in South Korea. For calculating a more accurate estimate of the geoid heights from the height anomalies, the terrain corrections due to the terrain masses over geoid have considered, the model for the topographic correction is a spherical harmonic expansion of the ETOPO2 DTM model. Geoid heights obtained from GPS and levelling in land area of South Korea are compared with those from the EGMs. The results show that EIGEN-CG03C EGM and EIGEN-GL04C EGM displayed the nearest results to GPS/leveling, and also confirmed the importance of terrain correction for geoid height in case of the uneven topography.

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Simulation of Atmospheric Dispersion over the Yosu Area -I. Terrain Effects- (여수지역 대기확산의 수치 모사 -I. 지형의 영향-)

  • 김영성;오현선
    • Journal of Korean Society for Atmospheric Environment
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    • v.16 no.3
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    • pp.211-223
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    • 2000
  • The atmospheric dispersion of a pollutant emitted from a hypothetical source located in the middle of the Yochon Industrial Estate was simulated by using the Regional Atmospheric Modeling System (RAMS). Four horizontally nested grids were employed: the coarsest one covered the southern part of the Korean Peninsula including Mt. Chiri and the finest one covered the Yochon Industrial Estate and the surrounding area. Wind fields were initially assumed horizontally homogeneous with a wind speed of 4m/s, the average for the Yosu area, and were developed without both external forces and diurnal changes in order to investigate the terrain-induced phenomena. Wind directions that could emphasize the terrain effects on the pollutant transport and that could carry pollutants to a highly-popluated area were selected for the dispersion study. A pollutant was released for 24hours from a grid-base volume source after a 24-h blank run for developing the wind field. The dispersion study showed that the pollutant from the present source location did not directly affect the Yosu City, but showed high concentrations at locations behind the hills 5 to 6 km away from the source according to wind directions. When the wind speed was low, close to calm condition, the pollutant was detected at upstream locations 6 to 7 km from the source. In comparison with the results from the RAMS simulation, the Industrial Source Complex Short-Term Model(ISCST3) predicted a narrow dispersion that was sensitive to the wind direction. When the wind velocity was affected by the local environment, the ISCST3 calculation using that data also gave a lop-sided result, which was different from the distribution of the pollutant reproduced by RAMS.

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