• Title/Summary/Keyword: topographical features

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A Study on the Edge Point Detection of Digital Elevation Model (수치표고모델의 임계점 추적에 관한 연구)

  • 최병길
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.14 no.1
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    • pp.111-118
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    • 1996
  • In this paper, topographic edge points are detected from digital elevation model. Topographic edge points can be considered as the points which have rapid variation from its neighborhood. In this study, these points are dotected by Laplacian operator and noise reduction system is applied to remove small ripple. The results of this study show that Laplacian operator detects efficiently the topographic edge points, and that noise reduction system by local variance is efficient to remove small ripple but inefficient to reconstruct topographical features.

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The Sliding Wear Characteristics of Ion-Nitrided Steel (이온질화 처리강 의 미끄름 마멸 특성)

  • 유봉환;성환태;조규식
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.8 no.3
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    • pp.217-223
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    • 1984
  • An attempt is made to predict the wear behavior of ion-nitrided metal, when wear arises from asperity interactions. The analysis demonstrates that wear mechanisms are not inconsistent with observed behavior, indicates and approaches to a better appreciation of the effects of such factors as nitrided layer formation and surface topographical features. It was found on ion-nitriding that penetration rate and case development are faster and wear properties of the final product are more improved than conventional gas and salt-bath methods of nitriding.

Development of Land Suitability Classification System for Rational Agricultural Land Use Planning (농지이용계획의 합리적 책정을 위한 농지적성 평가기법의 개발)

  • 황한철;최수명
    • Journal of Korean Society of Rural Planning
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    • v.3 no.2
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    • pp.102-111
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    • 1997
  • For rational agricultural land use planning, it is quite necessary to get hold of land suitability precisely and to make decision on land use patterns accordingly. In the methodological viewpoint, objective and scientific evaluation techniques for land suitability classification should be supported for the systematic land use planning. As one of technical development approaches to rational land use planning, this study tried to frame a land suitability evaluation system for agricultural purposes. Evaluation unit is defined as a tract of land bounded by road, other land units and topographical features. And quantification theory was applied in the determination works of evaluation criteria. The administrative area of Namsa-myon(district), Yongin-si(city), Kyunggi-do(province) was selected for the case study. In order to check the feasibility of the evaluation system developed in the study, field check team, consisting of 2 government officers and 2 representative farmers, carried out evaluation works by observation on 148 sample land units, 10% of total 1,480 ones. Between estimated and observed results, there showed very good relationship of its multiple correlation coefficient, R=0.9467.

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Self-assembly of Si-containing block copolymers for next-generation nanofabrication

  • Jeong, Yeon-Sik
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.02a
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    • pp.22-23
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    • 2011
  • As device dimensions shrink, it is increasingly important to develop fabrication methods that can create sub-15 nm features of regular or arbitrary geometry in a rapid, parallel, and efficient process. This talk will discuss approaches based on self-assembling hybrid polymers containing Si. The thin films of those materials systems can generate well-ordered periodic arrays of dots or lines. For achieving, long-range ordering, it is helpful to use lithographically-defined templates, which are in general much larger than the length-scale of self-assembled nanostructures. For example, the self-assembly of polymer nanostructures can easily be templated using an array of nanoscale topographical elements that act as guiding templates or surrogates for one of two microdomains. The solvent-vapor-induced tunability of pattern dimension and morphology will be discussed as well. Those material systems can excellently serve for high-precision self-assembly that can provide good resolution, reliability, and controllability and be considered as an option for a future nanomanufacturing technology.

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Geotechnical Characteristics of Soft Clayey Soil in South Korea (국내 연약 점성토 지반의 지반공학적 특성)

  • Oh, Seo-Hyun;Ha, Tae-Gyun;Chung, Choong-Ki
    • Proceedings of the Korean Geotechical Society Conference
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    • 2009.03a
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    • pp.922-929
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    • 2009
  • In this paper, 4 representative soft clayey soils in south Korea are selected to estimate the geotechnical characteristics and provide the instructions avaliable for construction works; Inchon Coast, Kum River Estuary, Kwangyang Bay, and Nakdong River Estuary. Total 2250 boring data are collected to construct the data base system on selected areas from Korea geotech DB system, scientific journals, theses, and site investigation reports. Considering the geological, topographical and regional features, geotechnical properties, deformation and strength characteristics of 4 soft clayey soils are evaluated by analyzing the constructed DB system statistically.

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A Method for Caption Segmentation using Minimum Spanning Tree

  • Chun, Byung-Tae;Kim, Kyuheon;Lee, Jae-Yeon
    • Proceedings of the IEEK Conference
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    • 2000.07b
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    • pp.906-909
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    • 2000
  • Conventional caption extraction methods use the difference between frames or color segmentation methods from the whole image. Because these methods depend heavily on heuristics, we should have a priori knowledge of the captions to be extracted. Also they are difficult to implement. In this paper, we propose a method that uses little heuristics and simplified algorithm. We use topographical features of characters to extract the character points and use KMST(Kruskal minimum spanning tree) to extract the candidate regions for captions. Character regions are determined by testing several conditions and verifying those candidate regions. Experimental results show that the candidate region extraction rate is 100%, and the character region extraction rate is 98.2%. And then we can see the results that caption area in complex images is well extracted.

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A Study for the Effect on the Uncertainty of Power Performance Testing of Windturbine by a Site Calibration (Site calibration이 풍력발전시스템 성능시험 불확도에 미치는 영향 연구)

  • Kim, Keon-Hoon;Hyun, Seung-Gun
    • Journal of the Korean Solar Energy Society
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    • v.31 no.2
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    • pp.107-112
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    • 2011
  • A comparison study between two performance testing results, one is on the site calibration not needed and the other is needed, was proceeded for the understanding on the effect of site calibration on the complex terrain. As a result, it is revealed that all of uncertainty components is effected by the topographical features dramatically. And the maximum difference of uncertainty reached at around 8% of rated capacity of wind turbine. So, the site calibration is an effective method to remove the variable wind effect by the ground complexity and must be proceeded before the power performance testing of a wind turbine.

Influence of trees and associated variables on soil organic carbon: a review

  • Devi, Angom Sarjubala
    • Journal of Ecology and Environment
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    • v.45 no.1
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    • pp.40-53
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    • 2021
  • The level of soil organic carbon (SOC) fluctuates in different types of forest stands: this variation can be attributed to differences in tree species, and the variables associated with soil, climate, and topographical features. The present review evaluates the level of SOC in different types of forest stands to determine the factors responsible for the observed variation. Mixed stands have the highest amount of SOC, while coniferous (both deciduous-coniferous and evergreen-coniferous) stands have greater SOC concentrations than deciduous (broadleaved) and evergreen (broadleaved) tree stands. There was a significant negative correlation between SOC and mean annual temperature (MAT) and sand composition, in all types of forest stands. In contrast, the silt fraction has a positive correlation with SOC, in all types of tree stands. Variation in SOC under different types of forest stands in different landscapes can be due to differences in MAT, and the sand and silt fraction of soil apart from the type of forests.

3dimension Topography Generation and Accuracy Analysis Using GIS (GIS를 이용한 3차원 지형도 생성 및 정확도 분석)

  • Nim Young Bin;Park Chang suk;Lee Cheol Hee
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.23 no.2
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    • pp.189-196
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    • 2005
  • Recently as map making skills developed and as digital maps prevailed, peoples began to take interest in the realistic 3dimension topography rather than the flat 2 dimension one. The experiment is done by using the topographical information from the digital maps, To analyze the preciseness of this 3dimension topography, analysis of the coordinate-changed standard map image and the location errors of the plane and height from digital values of the map's topography by layers and features, were done. The visual results of locational values differed by every programs of coordinate transformation. Errors of locations also appeared from the methods of correcting the visual sources, when deciding the standard source's datum point. The plan's accuracy of the image data coordinate transformation is about ${\pm}4.1m$. In ground distance, therefore, it is included in the allowed error of the 1:25,000 scale changed map, satisfying the plan's accuracy. Also, by the use of reasonably spaced grid, it satisfied the visual topographical accuracy. Because the 3 dimension topographical map can be produced effectively and rapidly by using various scale's standard map image and the digital map, the further practical use of 3 dimension topographic map made by using the existing topographies and changed maps has high expectations.

Climatological Features of Summer Precipitation in Korea (우리나라 여름철 강수량의 기후적 분포 특성)

  • Jo, Ha-Man;Choe, Yeong-Jin;Gwon, Hyo-Jeong
    • Journal of Korea Water Resources Association
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    • v.30 no.3
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    • pp.247-256
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    • 1997
  • Some climatological features of summer precipitation in Korea were studyed using the precipitation data of 15 stations of Korea Meteorological Administration where more than 30 years data since 1961 are available. The study included statistical analysis of precipitation by climatological normal values, and comparison of inter-annual variation of annual precipitation, summer precipitation and precipitation during the Changma. The relationships between them were also analyzed. It was revealed that, in Korea, more than half of annual precipitation was concentrated in summer season (June to August), and it was usually influenced by the Changma. The ratio of summer and Changma precipitation to the annual precipitation showed that effect of Changma was bigger in the central inland area, while comparatively smaller in the east coastal area and Cheju Island due to topographical effects. It was also shown that the fluctuation of the annual precipitation was less variable than those of summer and Changma precipitations. Thus, it was suggested that understanding the variation features of summer precipitation associated with monsoon activities was very important to figure out the change of annual precipitation for the national water resources planning.

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