• Title/Summary/Keyword: Surface Topography

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Research of Topography Changes by Artificial Structures and Scattering Mechanism in Yoobu-Do Inter-tidal Flat Using Remote Sensing Data (원격탐사자료를 이용한 인공구조물 건설에 의한 군산 유부도 조간대의 지형변화 및 표면특성에 관한 연구)

  • Xu, Zhen;Kim, Duk-Jin;Kim, Seung Hee
    • Korean Journal of Remote Sensing
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    • v.29 no.1
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    • pp.57-68
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    • 2013
  • Large-scale coastal construction projects, such as land reclamation and dykes, were constructed from the late twentieth century in Yoobu-Do region. Land reclamation combined with the dynamics of tidal currents may have accelerated local sedimentation and erosion resulting in rapid reformation of coastal topography. This study presents the results of the topography changes around Yoobu-Do by large-scale coastal constructions using time-series waterline extraction technique of Landsat TM/ETM+ data acquired from 1998 to 2012. Furthermore, the Freeman-Durden decomposition was applied to fully polarimetric RADARSAT-2 SAR data in order to analyze the scattering mechanisms of the deposited surface. According to the case study, the deposition areas were over 4.5 $km^2$ and distributed in the east, northeast, and west of Yoobu-Do. In the eastern deposition area, it was found that the scattering mechanism was difference from other deposition areas possibly indicating that different types of soil were deposited.

On the Planning of Drainage Structures in Irrigation Channels. -Special Emphasis on the Drainage Inverted Siphon- (용수로상의 배수구조물계획에 대하여 -배수잠관을 중심으로-)

  • 김철기
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.12 no.4
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    • pp.2078-2083
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    • 1970
  • The purpose of this study is to give the data neccesary for improving the planning of drainage structures, specially inverted siphons, in irrigation channels. With the samples of 15 drainage inlets, one drainage flume, 16 drainage inverted siphons and 6 drainage culverts in the 3 lines of irrigation channel under Chong-Won Irrigation Association, author abtained the following results. 1. It is presumed that design drainage discharge should be determined with some additional reserves, on the basis of the maximum rainfall intensity in local area and the size of drainage area on the topographical map, avoiding the way of eye measure. 2. Location of drainage inlet should be kept away from the place where topography can make lots of wash load, but when unavoidably allowing the inflow into irrigation channel, wash load outlet with even the purpose of drainage, or drainage flume in stead of drainage inlet should be taken account of. 3. It is presumed that drainage flume may be the structure which can perform its function from a structural point of view as far as topography permits. 4. Drainage inverted siphon should be avoided at any place as much as possible; a) In case that location of the siphon would be permitted only at paddy field, drainage area hauing the amount of discharge which requires more than 90cm in diameter could only be allowed. b) In this case, crest elevation of the tank of both inlet and outlet, at least, should not be lower than the surface level of paddy field. c) As far as topography and stratum permit, ratio of depth of outlet tank to head drop should be decreased as much as possible so that discharging efficiency of wash load could increase. d) In case of avoiding the setting of the siphon, irrigation aqueduct, irrigation inverted siphon, or drainage flume should be recommended in accordance with topography. 5. Discharging capability of wash load by drainage culvert appeared to depend hardly upon the diameter of the culvert, but greatly upon the location, specially near village, for there stones and dirts dumped may considerably be piled up. So, a counter plan for that is required.

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Three-dimensional Inversion of Resistivity Data (전기비저항 탐사자료의 3차원 역산)

  • Yi Myeong-Jong;Kim Jung-Ho;Cho Seong-Jun;Chung Seung-Hwan;Song Yoonho
    • Geophysics and Geophysical Exploration
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    • v.2 no.4
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    • pp.191-201
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    • 1999
  • The interpretation of resistivity data has, so far, mainly been made under the assumption that the earth is of relatively simple structure and then using one or two-dimensional inversion scheme. Since real earth structure and topography are fully three-dimensional and very complicated In nature, however, such assumptions often lead to misinterpretation of the earth structures. In such situations, three-dimensional inversion is probably the only way to get correct image of the earth. In this study, we have developed a three-dimensional inversion code using the finite element solution for the forward problem. The forward modeling algorithm simulates the real field situation with irregular topography. The inverse problem is solved iteratively using the least-squares method with smoothness constraint. Our inversion scheme employs ACB (Active Constraint Balancing) to enhance the resolving power of the inversion. Including Irregular surface topography in the inversion, we can accurately define the earth structures without artifact in the numerical tests. We could get reasonable image of earth structure by Inverting the real field data sets taken over highway bridge construction site.

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Model Parametrization on the Mixing Behavior of Coastal Discharges

  • Kim, Jong-Kyu
    • Journal of Ocean Engineering and Technology
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    • v.17 no.2
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    • pp.1-7
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    • 2003
  • A common feature in the three-dimensional numerical model experiments of coastal discharge with simplifed model and idealized external forcings is investigated. The velocity fields due to the buoyancy and flow flux, are spreaded radiately and the surface velocites are much greater than homegeneous discharges. The coastal dischargd due to the Coriolis force and flow flux are shaped a anticyclical gyre (clockwise) and determined the scale of the gyre in the coastal zone, respectively. The bottom topography restricts a outward extention of the coastal fronts and it accelerates a southward flow.

A Study on Geographical Characteristics of Ulleungdo and Dokdo Islands

  • Kim, Joo-Hwan;Park, Soo-Jin;Kong, Woo-Seok;Seo, Tae-Yeol;Yang, Bo-Kyung;Paik, In-Kie;Yeun, Jin-Sook
    • Journal of the Speleological Society of Korea
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    • no.80
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    • pp.5-9
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    • 2007
  • Ulleungdo and Dokdo is special island to all Korean people, The purpose of this study is to collect, sorting, analysis and rearrangement the photo data. The data collected from the published books and new photos. The quantity of data is so big, that it is necessary to divide the volume to publishing the books. For example, aerial photos(including marine topography), the relief of surface, culture and history, urban and settlement, sightseeing and economy, maps and figure and etc. The effect of the study is clear to the civics and students about patriotic sentiment etc.

Thin Film Elastohydrodynamic Lubrication of Nanometer Scale (나노미터 크기 유막에서의 탄성유체윤활)

  • 장시열
    • Tribology and Lubricants
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    • v.14 no.1
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    • pp.54-63
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    • 1998
  • In many practical lubricated contacts such as a rough concentrated contact on the sliding of nominally flat surfaces, the fluid may be of molecular (nanometer) scale owing to the asperity interactions on the surfaces. Under this condition, there is insufficient lubricant on the concentrated contact spot to maintain a realistic continuum. Rheological behavior for this kind of concentrated contact has been studied extensively to know whether the application of viscous fluid model is appropriate. The interaction of two rough surfaces is simplified as perfectly flat-rough surfaces contact under certain conditions by "composite topography" and for a nanometer scale fluid film, three kinds of rheological fluid behavior are analyzed in elastohydrodynamic asperity point contact.t contact.

The Characteristics of Aluminum Thin Films using DC Magnetron Sputtering (DC Magnetron Sputtering에 의해 증착된 알루미늄 박막의 특성)

  • Pyo, Jae-Hwack;Yeon, Chung-Kyu;Whang, Ki-Woong
    • Proceedings of the KIEE Conference
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    • 1993.11a
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    • pp.258-260
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    • 1993
  • Aluminum thin films were deposited on glass substrate using DC Magnetron Sputtering. Deposition rate, specular reflectance, and resistivity were investigated as a function of the input power, pressure, substrate temperature, and deposition time. Reflectance was reduced with increasing power, also with prolonging deposition time. Topography of the surface, which influences the properties such as electromigration, was observed from scanning electron microscope (SEM) and there was a close relation between the topography and measured reflectance.

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Analysis of Corneal Topography in Keratoconus (원추각막의 각막지형도 분석)

  • Kim, Douk-Hoon
    • Journal of Korean Clinical Health Science
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    • v.4 no.3
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    • pp.652-661
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    • 2016
  • The analysis of cornea morphology using corneal topographers is a clinical practice for the diagnosis of keratoconus in contact lens fitting. The recently technique has developed with the possibility of achieving a great number of measuring points of both anterior and posterior corneal surfaces in cornea. Also these data are used to extract a series of topographic valuation indices that permit to offer the most exact clinical diagnosis of keratoconus in contact lens fitting. This study describes the technologies in which current corneal topographers are based on the morphological characteristics that the keratoconus status observe on corneal surface. Therefore, this paper can provide that the analysis of corneal topographers applied for the diagnosis of keratoconus in contact lens fitting.

Thin Film Elastohydrodynamcic Lubrication of Nanometer Scale (나노 미터 크기 유막에서의 탄성유체윤활)

  • 장시열
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 1997.10a
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    • pp.173-182
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    • 1997
  • In many practical lubricated contacts such as a rough concentrated contact on the sliding of nominally flat surfaces, the fluid may be of molecular (nanometer) scale owing to the asperity interactions on the surfaces. Under this condition, there is insufficient lubricant on the concentrated contact spot to maintain a realistic continuum. Rheological behavior for this kind of concentrated contact was studied to know whether the application of viscous fluid model is appropriate. The interaction of two rough surfaces is simplified as perfectly flat-rough surfaces contact under certain conditions by "composite topography" and for a nanometer scale fluid film, three kinds of rheological fluid behavior are analyzed in elastohydrodynamic asperity point contact.t contact.

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Fundamental Morphological Consideration for the 3-D Shape Analysis of the Middle-aged Women's Breast (중년 여성의 3차원 유방 형상 분석을 위한 방법론 연구)

  • 이현영;홍경희
    • Journal of the Korean Society of Clothing and Textiles
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    • v.26 no.5
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    • pp.703-714
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    • 2002
  • This paper proposed the basic consideration for the reliable 3-D measurement and analysis of middle-aged women's breast using 3-D phase-shifting moire topography. The surface borderline of the breast based on the anatomical structure on the skin was suggested. Various breast dimensions that can be measured using 3-D measurement system and their measuring methods were discussed. Tips for the measurement of sagged breast were also proposed. It is expected that these basic considerations contribute to draw attention to the reliable measurement of women's breast and provide a kind of tools for the standardization of 3-D shape measurement of breast.