• Title/Summary/Keyword: terrain change

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Safety Inspection Surveying using Change Detection Technique (Change Detection 기법을 이용한 구조물 안전진단측량)

  • Choi, Chul-Ung;Khak, Jae-Ha;Kang, In-Joon
    • Journal of Korean Society for Geospatial Information Science
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    • v.3 no.2 s.6
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    • pp.151-158
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    • 1995
  • Change detection, image differencing technique, is the most widely used in a variety of image environments. The digital terrain model and digital images have the same data structure. This study applied digital terrain model and change detection technique for inspecting the deflection of the structure. Authors make digital terrain model from triangular irregular network(TIN) by leveling data and suggest to possibility recognize modification part and volumes by digital terrain model and change detection technique. Authors can reduce testing materials and man power, and displayed his modification part.

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Application of the EIASS for Assessing Changes in Terrain Features in Development Initiatives: A Case Study in South Korea (환경영향평가정보지원시스템(EIASS)을 활용한 국내 주요 개발사업의 지형변화 검토)

  • Sujung Heo;Dong Kun Lee;Eunsub Kim
    • Journal of Environmental Impact Assessment
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    • v.32 no.6
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    • pp.407-418
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    • 2023
  • This study conducted an analysis of terrain change indicators in major development projects in Korea, examining the correlation between terrain change indicators to derive foundational terrain change metrics based on different land use and slope types. The aim is to contribute to sustainable development by enhancing the efficiency of land utilization and landscaping, while minimizing environmental impacts in future development endeavors. Additionally, to apply the research findings in practical contexts, domestic regulations related to terrain were surveyed, and the compatibility and usability between these regulations and research analysis results were discussed. Based on this, the study seeks to explore strategies for more accurate and useful utilization of terrain change indicators in future research. As a result, in the tourism development, terrain changes predominantly occur in the order of flat land, hillly land, and mountain land, with the analysis indicating higher terrain changes in undulating hilly and mountainous lands compared to flat land. Furthermore, in industrial complex development, very steep (20°-30°) and extreme (30°-40°) slopes; in urban development projects, steep slope (15°-20°); in athletic service facility and tourist development, steep (15°-20°) and very steep (20°-30°) exhibit higher average terrain change indicators compared to other slope categories. The findings of our study can contribute to the formulation of strategies aimed at minimizing terrain disturbance in future domestic development projects and serve as foundational data for environmental impact assessments.

A Study on the Variation of Ground Safety Factor by Earthworks

  • Kim, Jinhwan;Kwon, O-Il;Baek, Yong;Kim, Chang-Yong
    • The Journal of Engineering Geology
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    • v.24 no.3
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    • pp.333-341
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    • 2014
  • The construction of roads, tunnels, and bridges results in changes to the local terrain that may influence the ground safety factor, which represents the stability of geotechnical structures. In this study, we assessed construction sites that had collapsed as a result of terrain change, and then simulated variation in the ground safety factor with respect to terrain change caused by road construction. We assumed steep slopes to simulate changes in terrain in a mountainous area and assumed that earthworks took place for road construction by cutting a platform into the slope and altering the slope angle of the terrain both above and below the road. We calculated values of the ground safety factor through a stability analysis of the slope both above and below the road, and examined the variation in the safety factor of the above- and below-road slopes with respect to changes in road width. We found that if the slope angle was the same above and below the road, then the change in the ground safety factor during/after road construction occurred in the slope below the road, and if the slope angle above the road differed from that below, then the change occurred in both the above- and below-road slopes. Furthermore, the ground safety factor was essentially constant for road widths exceeding 2-6 m, depending on both above- and below-road slope angle. The findings of this study can be used to guide the management of construction sites and to assess changes in ground stability during road construction work, particularly in the early stages of earthworks, when the road width is narrow.

A Study on the Evaluation of the Short-term Atmospheric Dispersion Models with Terrain Adjustment (지형을 고려한 단기 대기확산모형의 평가에 관한 연구)

  • 최일경;전의찬;김정욱
    • Journal of Korean Society for Atmospheric Environment
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    • v.6 no.2
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    • pp.125-134
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    • 1990
  • The purpose of this study is to assess the performance of Short-term atmospheric dispersion models --- ISCST, MPTER, VALLEY --- with terrain adjustment. The models are evaluated through correlation analysis, paired analysis and log-normal culmulative analysis between the measured and predicted concentrations in Samcheonpo area. The correlation coefficients between the measured and predicted concentrations turn out to be higher with terrain adjustment than those without terrain adjustment. In paired analysis, the mean differences and average absolute gross errors of concentrations do not change significantly with terrain adjustment. But the variances of the residuals become much smaller when the terrain is adjusted. Through the log-normal cumulative analysis, it is found that the terrain adjustment improve the prediction performance of MPTER and VALLEY, but do not affect significantly that of ISCST. Overall, it is concluded that the performance of short term atmospheric dispersion models improve when the terrain is considered in computation, especially in MPTER and VALLEY.

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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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Sensitivity of WindSIM in Complex Terrain

  • Shin, Chongwon;Han, Kyungseop
    • 한국신재생에너지학회:학술대회논문집
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    • 2010.11a
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    • pp.180.2-180.2
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    • 2010
  • The purpose of this research is to analyze the sensitivity of WindSIM in complex terrain. As the flat areas for wind turbine installation become scarce globally, it becomes inevitable to install wind turbines in complex terrain. In order to predict annual energy production (AEP) in a more precise manner in complex terrain, it is of great importance to conduct such research. Three parameters: reference velocity, roughness and resolution have been chosen to see to which parameter WindSIM was the most sensitive in terms of annual energy production in complex terrain. By fixing two parameters and setting one parameter as a variable, it could be easily found that how annual energy production was effected by the change in each parameter.

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Generation of Realistic Terrain Based on LOD Simplification and Fractal

  • Min, Hu;Zhen, Wang
    • International Journal of CAD/CAM
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    • v.8 no.1
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    • pp.37-40
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    • 2009
  • Based on the study of Digital Elevation Simplification Model and fractal theory, this paper put forward a new method to simulate complex terrain. That use simplified DEM data to construct terrain frame based on the quad tree at first, and then use fractal to generate the details of every node of the tree. In the process of construction, the LOD theory is used to simplify the terrain and get its typical data. According to the change of view position and direction, the paper gives a new way to judge the visibility of the surface patch. Experimental results show that this algorithm is simple, efficient and supports the real time dynamic simulation of terrain model.

Dynamic Simulation of Modifiable Bipedal Walking on Uneven Terrain with Unknown Height

  • Hong, Young-Dae;Lee, Ki-Baek
    • Journal of Electrical Engineering and Technology
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    • v.11 no.3
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    • pp.733-740
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    • 2016
  • To achieve bipedal walking in real human environments, a bipedal robot should be capable of modifiable walking both on uneven terrain with different heights and on flat terrain. In this paper, a novel walking pattern generator based on a 3-D linear inverted pendulum model (LIPM) is proposed to achieve this objective. By adopting a zero moment point (ZMP) variation scheme in real time, it is possible to change the center-of-mass (COM) position and the velocity of the 3-D LIPM throughout the single support phase. Consequently, the proposed method offers the ability to generate a modifiable pattern for walking on uneven terrain without the necessity for any extra footsteps to adjust the COM motion. In addition, a control strategy for bipedal walking on uneven terrain with unknown height is developed. The torques and ground reaction force are measured through force-sensing resisters (FSRs) on each foot and the foot of the robot is modeled as three virtual spring-damper models for the disturbance compensation. The methods for generating the foot and vertical COM of 3-D LIPM trajectories are proposed to achieve modifiable bipedal walking on uneven terrain without any information regarding the height of the terrain. The effectiveness of the proposed method is confirmed through dynamic simulations.

Wind tunnel modeling of flow over mountainous valley terrain

  • Li, C.G.;Chen, Z.Q.;Zhang, Z.T.;Cheung, J.C.K.
    • Wind and Structures
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    • v.13 no.3
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    • pp.275-292
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    • 2010
  • Wind tunnel experiments were conducted to investigate the wind characteristics in the mountainous valley terrain with 4 simplified valley models and a 1:500 scale model of an existing valley terrain in the simulated atmospheric neutral boundary layer model. Measurements were focused on the mean wind flow and longitudinal turbulence intensity. The relationship between hillside slopes and the velocity speed-up effect were studied. By comparing the preliminary results obtained from the simplified valley model tests and the existing terrain model test, some fundamental information was obtained. The measured results indicate that it is inappropriate to describe the mean wind velocity profiles by a power law using the same roughness exponent along the span wise direction in the mountainous valley terrain. The speed-up effect and the significant change in wind direction of the mean flow were observed, which provide the information necessary for determining the design wind speed such as for a long-span bridge across the valley. The longitudinal turbulence intensity near the ground level is reduced due to the speed-up effect of the valley terrain. However, the local topographic features of a more complicated valley terrain may cause significant perturbation to the general wind field characteristics in the valley.

Analysis of Terrain Data Change using Digital Elevation Data (수치표고자료를 활용한 지형자료변화 분석)

  • 이형석;송승호;배상호
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2004.11a
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    • pp.385-388
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    • 2004
  • Many environmental destruction factors are accompanied in the mining development work and the secondary environmental disaster and the induction factors are inhered. We aquired digital data using aerial photogrammetry to analyze the terrain current situation according to the development situation of the mining restoration plan. We made the object area to 3D model and conducted terrian change monitoring. Then, we presented the decision-making information to improve rational management according to the original state plan.

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