• Title/Summary/Keyword: 지표법

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Spectral Mixture Analysis in forest using Landsat-7 ETM+ (Landsat-7 ETM+영상을 이용한 산림지역의 혼합화소분석)

  • 이지민;이규성
    • Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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    • 2003.04a
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    • pp.157-162
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    • 2003
  • 중저해상도 광학영상의 순간시야각(instantaneous filed of view -IFOV)에 포함되는 공간에는 반사특성이 상이한 두 개 이상의 지표물이 존재하는 경우가 대부분이다. 영상분류와 같은 기존의 영상처리기법에서는 하나의 화소가 단일의 지표물을 대표한다는 가정에서 접근하였으나, 최근 화소의 혼합정도를 세분하는 분광혼합분석(spectral mixture analysis)기법이 개발되고 있다. 분광혼합분석법을 이용하여 혼합된 화소에 포함된 지표물을 분해(unmixing) 하고 그 효과를 분석하고자 하여 경기도 광릉국립수목원의 시험림 지역을 대상으로 Landsat-7 ETM+영상을 이용하여 선형혼합 모델을 적용하였고, 그 결과 각각의 화소를 6개의 End-member의 혼합비로 구분하였다. Endmember의 비율을 나타낸 영상을 분석하여 점유비율에 따른 활엽수와 침엽수의 구분을 할 수 있었고, 각 임상별의 특징도 얻을 수 있었다. 특히 침엽수의 경우 그림자의 효과가 높다는 특성도 파악 할 수 있었다. 분광혼합분석법은 기존의 전통 분류방법과는 달리 다양한 산림의 정보를 추출해 낼 수 있다.

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The effect of formation of spherical underground cavity on ground surface settlement : Numerical analysis using 3D DEM (구형지하공동 형성이 지표침하에 미치는 영향에 대한 3차원 개별요소해석)

  • Lee, Sang-Hyun;Lee, Hang-Lo;Song, Ki-Il
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.18 no.2
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    • pp.129-142
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    • 2016
  • The underground cavity known as one of the reasons of ground surface settlement is a discontinuous character. Therefore, it is limited to analyze with continuum analysis. In this research, The spherical underground cavity affecting the ground surface settlement is studied with Discrete Element Method. Ground properties, depth and diameter of the spherical underground cavity are chosen as factors of the spherical underground cavity and the effect of the each factor variations on the ground surface settlement is analyzed. Relative depth to the diameter of the spherical underground cavity is also studied. The result of the research suggests the basis of underground cavity collapse prediction and standard of support.

Analysis on the Reliability and Influence Factors of Refraction Traveltime Tomography Depending on Source-receiver Configuration (송수신기 배열에 따른 굴절 주시 역산의 영향 인자 및 신뢰성 분석)

  • Lee, Donguk;Park, Yunhui;Pyun, Sukjoon
    • Geophysics and Geophysical Exploration
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    • v.20 no.3
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    • pp.163-175
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    • 2017
  • In land seismic exploration, irregular surface topography and weathering layer in near surface distorts the reflected signals of data. Therefore, typical land seismic data should be compensated for this distortion by static correction. To perform the static correction, near-surface velocity is required, which can be obtained by seismic refraction survey. However, land seismic data is often acquired in a limited form of geometry depending on the equipment availability, accessibility condition, and permission for the survey site. In this situation, refraction analysis should be performed using reflection data because it is impossible to acquire refraction-oriented data due to limited source and receiver geometry. In this study, we aimed to analyze the reliability of the results obtained by refraction traveltime tomography when using reflection data with a limited number of sources and receivers from irregular surface topography. By comparing the inversion result from irregular topography with that from flat surface, we found that the surface topography affects the reliability of the inversion results to some degree. We also found that the number of sources has little effect on the inversion results unless the number of sources are very small. On the other hand, we observed that velocity distortion occurred in the overlapped part of receiver arrays when using a limited number of receivers, and therefore suggested the size of the least overlapping ratio to avoid the velocity distortion. Finally, we performed numerical tests for the model which simulates the surface topography and acquisition geometry of the survey region and verified the reliability analysis of inversion results. We identified reliable areas and suspicious area of the inverted velocity model by applying the analysis results to field data.

Development of a Climate Change Vulnerability Index on the Health Care Sector (기후변화 건강 취약성 평가지표 개발)

  • Shin, Hosung;Lee, Suehyung
    • Journal of Environmental Policy
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    • v.13 no.1
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    • pp.69-93
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    • 2014
  • The aim of this research was to develop a climate change vulnerability index at the district level (Si, Gun, Gu) with respect to the health care sector in Korea. The climate change vulnerability index was esimated based on the four major causes of climate-related illnesses : vector, flood, heat waves, and air pollution/allergies. The vulnerability assessment framework consists of six layers, all of which are based on the IPCC vulnerability concepts (exposure, sensitivity, and adaptive capacity) and the pathway of direct and indirect impacts of climate change modulators on health. We collected proxy variables based on the conceptual framework of climate change vulnerability. Data were standardized using the min-max normalization method. We applied the analytic hierarchy process (AHP) weight and aggregated the variables using the non-compensatory multi-criteria approach. To verify the index, sensitivity analysis was conducted by using another aggregation method (geometric transformation method, which was applied to the index of multiple deprivation in the UK) and weight, calculated by the Budget Allocation method. The results showed that it would be possible to identify the vulnerable areas by applying the developed climate change vulnerability assessment index. The climate change vulnerability index could then be used as a valuable tool in setting climate change adaptation policies in the health care sector.

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Improvement of Infiltration Performance Measurement in BTL (Build-Transfer-Lease) Sewer Rehabilitation Projects - Focusing on Jeju Special Self-Governing Province - (하수관거정비 임대형민자사업에 있어 침입수 성과지표의 개선에 관한 연구 - 제주특별자치도를 중심으로 -)

  • Ko, Young-Nam;Lee, Dong Wook
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.36 no.6
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    • pp.1133-1143
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    • 2016
  • The purpose of this study is to improve project performance analysis indicators for BTL sewer rehabilitation projects. Among the assessment indicators for BTL sewer rehabilitation projects, an infiltration assessment indicator is given a high score of 17.5 points as a single assessment item. This infiltration assessment indicator is assessed focusing on the amount of infiltration, and presently calculated according to 'Nighttime Domestic Flow Evaluation' method. However, this assessment indicator's failure to reflect the geological features of Jeju region is emerging as a problem in the operational stage. Thus, this study intended to compare and analyze the calculation result depending on the assessment indicators and the actual amount of infiltration, centering on Jeju region. To this end, this study analyzed the amount of infiltration in five areas of Jeju Province calculated according to 'Nighttime Domestic Flow Evaluation' method. Also, a complete enumeration survey was carried out about the conditions for actual infiltration occurrence. According to the results of this survey, ground water level is distributed lower than the level of sewer pipes. The results of a sewer pipe function test show there was no infiltration occurrence caused by sewer pipe defect. So, it is concluded that 'Nighttime Domestic Flow Evaluation' method, which is utilized for the current assessment indicator, is not appropriate to apply to Jeju region, and it is thought that there is a need to establish infiltration criteria specialized for Jeju region.

A Study on Compilation of Monthly Benchmarked Construction Indicators (벤치마킹 기법을 활용한 월별 건설지표 작성)

  • Min, Kyung-Sam
    • Survey Research
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    • v.10 no.1
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    • pp.113-139
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    • 2009
  • It is desirable to use a monthly benchmarked construction indicator which contains the characteristics of statistical data in an annual survey in order to analyze the cyclical phenomenon of the construction activity. The benchmarked indicator is expected to improve the data quality in terms of accuracy, consistency, comparability, and completeness. In this paper, benchmarking methodologies of compiling monthly construction indicators arc researched by using a monthly prompt data holding short - term fluctuations and an annual survey data regarded as more accurate statistics than monthly data. The benchmarking is the methodology by which a high frequency data should he adjusted in order to hold the short-term and cyclical phenomena, and the long - term trend of two data groups with ensuring the consistency of an annual summation between a high frequency data and a low frequency data. This paper considered the numerical approach like pro rata distribution method, proportional Denton method, EFL or HP filter Benchmark - to - Indicator ratio method, and the model - based approach such as Chow and Lin method, $Fem{\acute{a}}ndez$ method. Also, the benchmarked construction indicators were estimated by early mentioned benchmarking methods with practical data, and these methods were empirically reviewed and compared. In case of construction indicators with severe seasonal fluctuations and irregulars, the numerical approach seemed to be performed more correctly than the model- based approach. Among numerical methods, the proportional Denton method used in general was a little nice. The HP filter Benchmark - to - Indicator ratio method may be considered with survey errors or measurement errors in an annual survey data.

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A Study on developing advancement indexes of a urban logistics plan in Incheon Metropolitan City (인천시 도시물류계획 효율적 운영을 위한 개선지표 개발)

  • Chung, Tae-Won
    • Journal of Navigation and Port Research
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    • v.35 no.8
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    • pp.683-689
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    • 2011
  • Urban logistics plan of the previous cargo distribution law has changed into city logistics plan of logistics policy law in which its contents adjusted into direction to improve logistics industries, economic well-being and lifestyle conditions of the city. But the city logistics planning didn't include yet a systematic backbone that plans a vision, performs propelled plan to realize it, and then gives feedback through scientific evaluation indexes. In this context, this paper reviews the previous logistics plans and helps operating and managing a efficient city logistics plan a mid-long term through representative index development required to establish city logistics plan.