• 제목/요약/키워드: Density map

검색결과 563건 처리시간 0.027초

부산지역의 산사태 위험 연구 (A Study on Potential Risk of Landslide in Pusan)

  • 이수곤
    • 한국환경복원기술학회지
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    • 제2권2호
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    • pp.9-23
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    • 1999
  • Pusan's reputation as the nation's most crowded city in terms of population density is attributable to its huge mountains which allow only small portion of residential area to its large population. Rapid increase of urban population on limited amount of land had naturally led its developments efforts to mountainous area giving rise to the concern of potential landslide. This study on urban Pusan and "Landslide Hazard Map" thereof is prepared in an attempt to avoid disasters created by landslide and also as a reference for city planners. The Map shows that the area covering 38% to 43% of urban Pusan has the potential for landslide. The study also shows that various civil works involving massive land excavation had been more direct cause of landslides in Pusan than such traditional factors as locations, ground slopes, rock types and topography of the area concerned.

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풍력자원 평가를 위한 한반도 수치바람모의 (Numerical Simulation to Evaluate Wind Resource of Korea)

  • 이화운;김동혁;김민정;이순환;박순영;김현구
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2008년도 춘계학술대회 논문집
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    • pp.300-302
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    • 2008
  • For the evaluation of wind resources, numerical simulation was carried out as a tool for establishing wind map around the korean peninsula. Initial and boundary condition are given by 3 hourly RDAPS(Regional Data Assimilation and Prediction System) data of KMA(Korea Meteorology Administration) and high resolution terrain elevation land cover(30 seconds) data from USGS(United States Geological Survey). Furthermore, Data assimilation was adopted to improve initial meteorological data with buoy and QuikSCAT seawinds data. The simulation was performed from 2003 to 2006 year. To understand wind data correctly in complex terrain as the korean peninsula, at this research, Wind map was classified 4 categories by distance from coastline and elevation.

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전국단위 재해위험도에 기초한 급경사지 재해의 단위권역 구분 (Division of Small Unit Based on a Nationwide Disaster Vulnerability Map)

  • 김성욱;최은경;박덕근;오정림
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2010년도 춘계 학술발표회
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    • pp.927-932
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    • 2010
  • This study made a nationwide metropolitan region map on the basis of disaster vulnerability and administrative boundary, and based on it, it divided small-sized regions and constructed disaster history of each region. For the disaster vulnerability, the study wrote slope, aspect, curvature, wetness index, and drainage density, compared and analyzed regions with disaster and geomorphic elements to distinct the factor with high correlations, and based on it, it divided small-sized regions for forecasting and warning system of middle regions(Gangwon province, Chungchung province, and Jeolla province). Through the method, Gangwon region were divided into 4 small-sized regions, Chungchung into 5 small-sized regions, and Jeolla into 6 small-sized regions.

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Improved Super-Resolution Algorithm using MAP based on Bayesian Approach

  • 장재용;조효문;조상복
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2007년도 심포지엄 논문집 정보 및 제어부문
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    • pp.35-37
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    • 2007
  • Super resolution using stochastic approach which based on the Bayesian approach is to easy modeling for a priori knowledge. Generally, the Bayesian estimation is used when the posterior probability density function of the original image can be established. In this paper, we introduced the improved MAP algorithm based on Bayesian which is stochastic approach in spatial domain. And we presented the observation model between the HR images and LR images applied with MAP reconstruction method which is one of the major in the SR grid construction. Its test results, which are operation speed, chip size and output high resolution image Quality. are significantly improved.

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Geographical Visualization of Rare Events

  • Roh, Hye-Jung;Jeong, Jae-Joon
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2007년도 Proceedings of ISRS 2007
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    • pp.434-437
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    • 2007
  • Maps contain and effectively visualize a number of spatial information. Advances in GIS enable researchers to analyze and represent spatial information through digital maps. Choropleth maps represent different quantities showing usually rates, percentages or densities. Generally, researchers make choropleth maps using raw rates. But, if the events are rare, raw rates cannot be sufficient in representing spatial phenomena. That is to say, if the population is large and events are rare, we cannot be sure that the raw rate is correct. The objective of this study is to make choropleth maps by several rate calculation methods and compare them. We use three methods in choropleth mapping; a raw rate, empirical Bayesian method, and spatial rate method which use prior probabilities. The experiments reveal that maps are somewhat different by used methods. We suggest that a raw rate method can not be an only way to make a rate map and researchers should choose an appropriate method for their objectives.

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국가바람지도에 의한 풍력자원 잠재량 산출방법 (Estimation Method of Wind Resource Potential Using a National Wind Map)

  • 김현구;장문석;김은일;이화운;이순환;김동혁
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2008년도 추계학술대회 논문집
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    • pp.332-333
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    • 2008
  • This paper presents an estimation method of national wind resource potential using a national and GIS(Geographical Information System). The wind resource potential is classified into theoretical, geographical and technical potentials and each category narrows down the previous definition by excluding impossible area to be developed as a wind farm using GIS datasets for onshore and offshore. As a basic unit of wind energy potential at a certain area, API(Average Power Intercepted) is calculated from WPD(Wind Power Density) given by a national wind map which is established by numerical wind simulation, so that a logical and relatively accurate potential estimation is possible comparing with other methods based on a field measurement interpolation which is inevitable to avoid critical assumptions.

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산사태 발생지역에서의 민감성 분석에 관한 연구 (Analysis of Susceptibility in Landslide Distribution Areas)

  • 양인태;유영걸;천기선;전우현
    • 한국측량학회:학술대회논문집
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    • 한국측량학회 2004년도 추계학술발표회 논문집
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    • pp.381-384
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    • 2004
  • The goal of this study is to generate a landslide susceptibility map using GIS(geographic information system) based method. A simple and efficient algorithm is proposed to generate a landslide susceptibility map from DEM(digital elevation model) and existing maps. The categories of controlling factors for landslides, aspect of slope, soil, topographical index, landuse, vegetation are defined, because those factors are said to have relevance to landslide and are easy to obtain theirs sources. The weight value for landslide susceptibility is calculated from the density of the area of landslide blocks in each class. Finally, a map of susceptibility zones is produced using the weight value of all controlling factors, and then each susceptibility zone is evaluated by comparing with the distribution of each controlling factor class.

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Testing Gravitational Weak-lensing Maps with Galaxy Redshift Surveys

  • Ko, Jongwan
    • 천문학회보
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    • 제39권1호
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    • pp.42.1-42.1
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    • 2014
  • A gravitational weak-lensing map provides a weighted "picture" of the projected surface mass density and is to be an important tool for identifying "mass-selected" clusters of galaxies. However, weak-lensing maps have a limitation due to the projection of large-sclae structure along the line-of-sight. Geller et al. (2010) and Kurtz et al. (2012) compared massive clusters identified in a dense redshift survey with significant weak-lensing map convergence peaks. Both assessments of the efficiency of weak-lensing map for cluster identification did not draw a general conclusion, because the sample is so small. Thus, we additionally perform deep imaging observations of fields in a dense galaxy redshift survey that contain galaxy clusters at z~0.2-0.5, using CFHT Megacam. Our study will provide an important opportunity to examine the efficiency and completeness of a weak-lensing selection, and further to improve the method of cluster identification in future weak-lensing surveys.

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Weak Lensing Mass Map Reconstruction of Merging Clusters with Convolutional Neural Network

  • Park, Sangnam;Jee, James M.;Hong, Sungwook E.;Bak, Dongsu
    • 천문학회보
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    • 제44권2호
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    • pp.75.1-75.1
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    • 2019
  • We introduce a novel method for reconstructing the projected dark matter mass maps of merging galaxy clusters by applying the convolutional neural network (CNN) to their weak lensing maps. We generate synthesized grayscale images from given weak lensing maps that preserve their averaged galaxy ellipticity. We then apply them to multi-layered CNN with architectures of alternating convolution and trans-convolution filters to predict the mass maps. We train our architecture with 1,000 Subaru/Suprime-Cam mock weak lensing maps, and our method have better mass map prediction than the Kaiser-Squires method with the following three aspects: (1) better pixel-to-pixel correlation, (2) more accurate finding of density peak position, and (3) free from mass-sheet degeneracy. We also apply our method to the HST weak lensing map of the El Gordo cluster and compare our result to the previous studies.

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Micro-scale surface texturing을 기반으로 한 저마찰효과에 대한 기초연구 (Fundamental study on the effect of friction reduction based micro-scale surface texturing)

  • 채영훈;김석삼
    • 한국윤활학회:학술대회논문집
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    • 한국윤활학회 2004년도 학술대회지
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    • pp.17-24
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    • 2004
  • Surrface texturing of tribological application is another attractive technology of friction reducing. Also, reduction of friction is therefore considered to be a necessary requirement for improved efficiency of machine. In this paper attempts to investigate the effect of density for micro-scale dimple pattern using photolithography on bearing steel flat mated with pin-on-disk. We demonstrated the lubrication mechanism for a Stribeck curve, which has a relationship between the friction coefficient and a dimensionless parameter for lubrication condition. It is found that friction coefficient is depended on the density of surface pattern. It was thus verified that micro-scale dimple could affect the friction reduction considerably under mixed and hydrodynamic lubrication conditions from based on friction map. Lubrication condition regime has an influence on the friction coefficient induced the density of micro dimple.

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