• Title/Summary/Keyword: Topography analysis

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Characterization of Debris Flow at Various Topographical Division Sizes (지형분할 격자크기에 따른 토석류 흐름 특성)

  • Jin, Hyunwoo;Hwang, Youngcheol
    • Journal of the Korean GEO-environmental Society
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    • v.16 no.3
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    • pp.49-55
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    • 2015
  • The rainfall pattern, rainfall intensity as well as topographical conditions used for the analysis of debris flow affect, in general, the magnitude of debris flow and flow velocity, when debris flow occurs. The consideration of topographical conditions implies that the topography is equally divided into grids and the slope of inside the grid is computed as an average, leading to, in turn, obtain the closer results to the reality as the grid is smaller in the case of the severely bended topography. Although the size of grid should be as small as possible so as for more accurate analysis of debris flow, the analysis of debris flow has been so far conducted by using sparsely divided grids due to the limitation of analysis algorithm, computational ability and running time. So, it is necessary to suggest an appropriate grid size for the practical approaches. Therefore, this study presents the evaluation of the effect of the size of a grid on the debris flow besides the factors which referred to the previous studies such as accumulated rainfall, rainfall intensity and rainfall duration time. From this, it enables to suggest a rational and practical grid size for topography to be divided.

Transcription Characteristics in the Molding of Aspheric Glass Lenses for Camera Phone Module (휴대폰 카메라용 비구면 Glass 렌즈 전사특성 분석)

  • Cha, D.H.;Lee, J.K.;Kim, M.J.;Lee, D.K.;Kim, H.J.;Kim, J.H.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2008.10a
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    • pp.363-366
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    • 2008
  • The transcription characteristics in the molding of aspheric glass lenses for camera phone modules have been investigated experimentally. The surface topographies of both the form and the roughness were compared between the mold and the molded lens. The molded lens showed a transcription ratio of 93.4%, which is obtained by comparing the form accuracy (PV) values of the mold and the molded lens. The transcription of the roughness topography was ascertained by bearing ratio analysis.

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Suggestion of the Relative Elevation Analysis Methods for Conservation of Local Topography : Focused on Analysis Range (지역규모의 지형경관 보전을 위한 상대고도 분석 방법론 제안 : 분석범위 설정을 중심으로)

  • Song, Wonkyong
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.17 no.5
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    • pp.19-28
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    • 2014
  • Given the structure of Korean mountains, it is more appropriate to apply the relative elevation method than the absolute elevation method. However, so far there were not suitable quantitative methodologies to analyze relative elevation, these analytical concepts were difficult to be utilized in urban environmental planning. This study suggested three methods for analyzing relative elevation, and one method for setting the analytical scope of relative elevation by calculating terrain relief. The results showed that the procedure considering 500m radius of each point and standardizing to 30% of the 7th height ridge was the most effective method to extract the local topography. This methodology is the quantitative tool to be able to conserve local important hills and ridges, and apply to fields of urban environmental planning and ecological restoration, especially urban ecological network.

Transcription Characteristics in the Molding of Aspheric Glass Lenses for Camera Phone Module (휴대폰 카메라용 비구면 Glass렌즈 전사특성 분석)

  • Cha, Du-Hwan;Kim, Hye-Jeong;Kim, Jeong-Ho
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.11a
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    • pp.336-336
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    • 2008
  • The transcription characteristics in the molding of aspheric glass lenses for camera phone modules have been investigated experimentally. The surface topographies of both the form and the roughness were compared between the mold and the molded lens. The molded lens showed a transcription ratio of 93.4%, which is obtained bycomparing the form accuracy (PV) values of the mold and the molded lens. The transcription of the roughness topography was ascertained by bearing ratio analysis.

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East 3-Dimensional Shape Reconstruction Using Phase-Shifting Grating Projection Moire Method (위상천이 영사식 모아레법을 이용한 고속 3차원 형상복원)

  • 최이배;구본기;정연구
    • Proceedings of the Korean Society for Emotion and Sensibility Conference
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    • 1998.11a
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    • pp.111-115
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    • 1998
  • A phase-shifting projection moire method particularly intended for high-speed three-dimensional shape reconstruction of diffuse objects is presented. Emphasis is on realization of phase-shifting fringe analysis in projection moire topography using a set of line grating pairs designed to provide different phase shifts in sequence. Further a time-integral fringe capturing scheme is devised to remove undesirable high frequency original grating patterns in real-time without time-consuming software image processing. Finally the performances of the proposed method are discussed with measurement results.

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Terrain reference navigation algorithm based on cross-correlation matching using topography characteristics (지형의 특성을 이용한 상호상관정합 기반 지형참조항법 알고리즘)

  • Lee, Bo-Mi;Kwon, Jay-Hyoun
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2010.04a
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    • pp.161-164
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    • 2010
  • The study on terrain referenced navigation has been proceeded from 1940s in advanced country with the object of military. In this study, the analysis regarding algorithm developed using cross-correlation matching algorithm and extended Kalman filter and simulation will be introduced. As a result, the standard deviation of position error from cross-correlation matching algorithm has been calculated 34.3m. It meant that the result has stable accuracy on the navigation. However, further study on terrain referenced navigation based on analysis of various topographic characteristics should be performed.

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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.

Research on the Relation between Musculoskeletal symptoms and Diagnosis using Moire Topography among Workers at an Automobile Manufacturing Plant (자동차회사 근로자를 대상으로 한 근골격계 자각증상과 moire 영상 진단과의 관계 연구)

  • Chun Eun-Joo;Lee Young-Gil;Jahng Doo-Sub;Lee Ki-Nam;Song Yung-Sun
    • Journal of Society of Preventive Korean Medicine
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    • v.5 no.2
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    • pp.69-92
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    • 2001
  • The purposes of this study were to offer foundation making more certain standards of musculoskeletal disorder diagnosis, We researched musculoskeletal symptoms degrees, frequencies, and cares and then examined relation between musculoskeletal symptoms and diagnosis of musculoskeletal conditions using moire topography among workers at an automobile manufacturing plant. Therefore we propose the possibility of moire topography as diagnosing utilities of musculoskeletal disorders. Methods: This study was to examine the general characteristics, complaints of musculoskeletal symptoms, and work-related musculoskeletal disorder rates of cervicobrachial and lumbar area by survey among 435 workers at an automobile manufacturing plant and then to show each frequency and percentage, In the diagnosis using moire topography, we studied pain control necessity of cervicobrachial and lumbar area, 435 subjects were classified by 5 levels: A(no symptoms), B(need management), C(need treatment) and then more divided by B1(light symptoms)/B2(heavy symptoms), C1(light symptoms)/C2(heavy symptoms), And musculoskeletal areas were divided by 2 parts, cervicobrachial area(neck, shoulder, arm&elbow, and wrist&hand) and lumbar area, Then, frequency and percentage of each musculoskeletal areas(cervicobrachial and lumbar area) were appeared. At last, Pearson's chi-square test analysis was utilized to observe the relation between diagnosis using moire topography and general characteristics and the relation between diagnosis using moire topography and work-related complaint of musculoskeletal symptoms of cervicobrachial and lumbar area, Results: The subjects employed for this research were categorized into; by gender, all of them were males(l00%): by age, under 35 years 12 %, 36-40 years 56.3%, 41-45 years 26.3 %, and above 46 years 5.3% with 36-40 years accounting for most of it. By living location, owned houses represented 69.7%, rented houses 23.4%, monthly-rented 1.6%, the others 5.3%; by education, middle school and lower represented 3.0%, high school 89.4%, and junior college and higher 7.6% with high school occupying most of the group. By marital status, married represented 95.2%, unmarried 4.1%, and the others 0.7% with most of them married; by alcohol, drinking represented 81.8% and non-drinking 18.2%; by smoking status, smoking represented 53.6%, non-smoking 46.4% with no big difference between them. By working time(hours/week), below 50 represented 26.9%, 50-60 67.6%, above 60 5.5%; by working time(hours/day), below 9 represented 21.6%, 10-12 73.1%, above 13 5.3%; by job tenure(years), below 10 represented 25.1%, 11-15 54.3%, 16-20 15.2%, above 21 5.5%. By personal income per year, below 30 million won represented 11.0%, 30-40 84.8%, above 40 4.1%; by sleeping hours, below 6 hours represented 26.7%, 7-8 hours 69.9%, above 9 hours 3.4%. Complaint rates of musculoskeletal symptoms and work-related musculoskeletal disorder rates were 63.9% and 54.9% with shoulder area occupying most of both them. By pain degree of musculoskeletal symptoms, shoulder area represented $2.73{\pm}0.84$, lumbar area $2.66{\pm}0.86$, wrist and hand area $2.59{\pm}0.86$, neck area $2.55{\pm}0.74$, and arm and elbow area $2.48{\pm}0.71$. By cares about musculoskeletal symptoms, taking medication or care represented 34.4%-46.7%, absence or leave 15.4%-28.7%, and job transfer 6.3%-11.5%. So experienced cases more than one thing among cares about musculoskeletal symptoms represented 39.6%-54%. In the diagnosis using moire topography, pain control necessity of cervicobrachial area was shown below; A(no symptoms) 20.7%, B1(need management/light symptoms) 64.6%, B2(need management/heavy symptoms) 11.5%, C1(need treatment/light symptoms) 3.0%, C2(need treatment/heavy symptoms) 0.2%. By lumbar area, A(no symptoms) 8.7%, B1(need management/light symptoms) 52.2%, B2(need management/heavy symptoms) 30.3%, C1(need treatment/light symptoms) 8.7%, C2(need treatment/heavy symptoms) was none. In the relation between pain control necessity and general characteristics, age(P=0.013), education(P=0.000), and job tenure(P=0.012) with pain control necessity showed differences with significance. The relation between pain control necessity and complaint of musculoskeletal symptoms of cervicobrachial and lumbar area showed no difference with significance; in cervicobrachial area represented P=0.708, lumbar area P=0.318 Conclusions: This study for musculoskeletal symptoms on workers at automobile manufacturing plant showed that complaint rates of musculoskeletal symptoms for cervicobrachial and lumbar area were so high, 63.9%. But Pearson's chi-square test analysis was utilized to study the relation between musculoskeletal symptoms and the diagnosis using moire topography, showed no differences with significance. They have no differences with significance, but the prevalence rates of diagnosis using moire topography for cervicobrachial and lumbar area were more higher than complaint rates of musculoskeletal symptoms; complaint rates of musculoskeletal symptoms were 52.4%, 34.5% and the diagnosis using moire topography were 79.3%, 91.3% for cervicobrachial and lumbar area. The results of this study indicate that the diagnosis using moire topography can find weak musculoskeletal disorders that an individual can not feel, not be judged work-related musculoskeletal disease. Therefore, this study has an important meaning that diagnosis using moire topography can predict and control own physical condition complete musculoskeletal disorders beforehand, since oriental medicine theory considers that prevention is important.

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Land Subsidence Survey and Analysis Using the Terrestrial LIDAR in Jakarta Bay, Indonesia

  • Park, Han-San
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.19 no.3
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    • pp.233-240
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    • 2013
  • Jakarta is the capital city of Indonesia which has problems of land subsidence with the rates of about 1 to 15 cm/year, up to 20-25 cm/year. The study has examined the land subsidence in Pantai Mutiara, Jakarta Bay which is a reclaimed area by using the Terrestrial LIDAR survey technique. The Terrestrial LIDAR survey results show that the survey site has mean elevation of 0.24 m with the highest elevation of 0.93 m and lowest - 0.35 m. Considering that AHHW (approximate highest high water) is 0.51 m, many areas of the survey site are lying below the AHHW. Pantai Mutiara area is showing various subsidence rates depending on sites although the site is relatively narrow and small (about 1 $km^2$). There is elevation differences of almost 1m within the site. In this study, key information including topography, dike height distribution, and future coastal flooding risk of the survey area was able to be provided by Terrestrial LIDAR survey conducted only once. Especially, as the 3D precision topography effectively conveys important messages relating to vulnerability of the site, policy makers and stakeholders can easily understand the situation of the site.

Two-Wavelength Phase-Shifting Projection $Moir\acute{e}$ Topography for Measurement of Three-Dimensional Profiles with High Step Discontinuities (고단차 불연속 형상의 3차원 측정을 위한 이중파장 위상천이 영사식 무아레)

  • Kim, Seung-Woo;Oh, Jung-Taek;Jung, Moon-Sik;Choi, Yi-Bae
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.23 no.7 s.166
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    • pp.1129-1138
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    • 1999
  • [$Moir\acute{e}$] technique is now being extensively investigated as a fast non-contact means of three-dimensional profile measurement especially for reverse engineering. One problem with $moir\acute{e}$ technique is so called $2\pi$-ambiguity problem that limits the maximum step height difference between two neighboring sampling points to be less than half the equivalent wavelength of $moir\acute{e}$ fringes. In this investigation, a new two-wavelength scheme of projection $moir\acute{e}$ topography is proposed and tested to cope with the $2\pi$-ambiguity problem. Experimental results are discussed to assess the new method in measuring large objects with high step discontinuities.