• Title/Summary/Keyword: 박종화

Search Result 393, Processing Time 0.028 seconds

Polarization recording and reconstruction in the chalcogenide As-Ge-Se-S thin films (비정길 칼코게나이드 As-Ge-Se-S 박막에서 편광기록 재생)

  • 장선주;박종화;손철호;정홍배
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.13 no.9
    • /
    • pp.781-785
    • /
    • 2000
  • Chalcogenide glasses are suggested as a candidate for optical recording. In this study, we have investigated the holography recording and reconstruction of the polarization state in chalcogenide As$_{40}$ Ge$_{10}$Se$_{15}$ S$_{35}$ thin films. We have used a He-Ne laser light(633nm) to probe and record of the grating. Also the polarization state of object beam was modulated with a λ/4 wave plate. The polarization state of the +1st order diffracted beam was generated by readout of the grating with a linearly polarized reference beam. It was the same-handed polarization state as the polarization state of the recording beam. The result is shown that the diffraction efficiency of circularly polarized recording represents higher than other polarization state.ate.e.

  • PDF

LAND COVER CHARACTERISTICS OF MOUNTAIN REGIONS IN NORTH KOREA (북한 산악지역의 개간지 및 산림 특성에 관한 연구)

  • Cha, Su-Young;Park, Chong-Hwa
    • Proceedings of the KSRS Conference
    • /
    • 2008.03a
    • /
    • pp.109-112
    • /
    • 2008
  • 현재 북한 토지피복 특성 중의 하나인 과도한 산지의 농지로의 전용은 홍수 등 자연재해를 일으키는 원인이 되고 있지만 북한에 대한 참조자료의 부족으로 피해규모나 상황에 대한 이해가 부족하다. 본 연구는 북한 양강도 산간지역을 대상으로 개간농지와 산림의 토지피복특성을 가을시기(2005 년 10 월 25 일) Quickbird (<0.6m) 위성영상의 육안분석과 분광특성을 이용하여 정확한 토지피복분류에의 기초 정보를 제공하는 것을 목적으로 한다. 토지피복 유형별 Training area 의 ROI(Region of Interest)의 면적은 2500pixel 로 하였고, 이것을 다시 .shp 파일로 변환하여 GoogleEarth 에서 표고 및 경사 등 보다 자세한 지형지물을 확인하였다. Quickbird 영상의 NDVI 분석을 통해 0.2 정도에서 식생과 농경지로 구분하는 임계값(Threshold)을 추정할 수 있었지만 늦게까지 추수를 끝내지 않은 농작물이나 이모작 농작물의 경우는 산림과 혼재되어 나타나고 있었다. 또한, 산림의 북사면은 수역 다음으로 낮은 NDVI 값을 나타내어 지형의 영향이 나타나고 있음을 알 수 있었다.

  • PDF

Characteristics of Land-use Changes Northern Cheongju Region using Landsat Images and DEM (Landsat영상과 DEM을 이용한 청주북부지역의 토지이용 변화특성)

  • Na, Sang-Il;Park, Jong-Hwa
    • Proceedings of the Korea Water Resources Association Conference
    • /
    • 2007.05a
    • /
    • pp.667-672
    • /
    • 2007
  • Land-use in Cheongju region is changing rapidly because of the increased interactions of human activities with the environment as population increases. We used multi-temporal Landsat images (1991 and 2000) and DEM data in a post-classification analysis with GIS to map land-use distribution and to analyse factors influencing the land-use changes for Cheongju City. Land-use statistics revealed that substantial land-use changes have taken place and that the built-up areas have expanded by about $17.57km^2(11.47%)$ over the study period (1991-2000). Agricultural lands and forests have decreased substantially while urban and barren lands have been on the increase. Rapid economic developments together with the increasing population were noted to be the major factors influencing rapid land use changes. Urban expansion has replaced urban and barren lands, thereby affecting habitat quality and leading to serious environmental degradation.

  • PDF

Analysis of Relationship between Vegetation Cover Rates and Surface Temperature Using Landsat TM Data (Landsat TM 데이터에 의한 식생피복율과 지표면온도와의 관계 해석)

  • Park, Jong-Hwa;Na, Sang-Il;Kim, Jin-Su
    • Proceedings of the Korean Society of Agricultural Engineers Conference
    • /
    • 2005.10a
    • /
    • pp.569-573
    • /
    • 2005
  • Land surface temperature(LST) is one of the key parameters in physics and meteorology of land-surface processes on regional and global scales. Urban Heat Island(UHI), a meteorological phenomenon by which the air temperature in an urban area increases beyond that in the suburbs, grows with the progress of urbanization. Satellite remote sensing has been expected to be effective for obtaining thermal information of the earth's surface with a high resolution. The main purpose of this study is to produce LST map of Cheongju and to analyze the spatial distributions of surface heat fluxes in urban areas. This study, taking Cheongju as the study area, aims to examine relationship between vegetation cover rates and surface temperature, and to clarify a method for calculation surface temperature with Landsat TM thermal images.

  • PDF

NIR Band Extraction for Daum Image and QuickBird Satellite Imagery and its Application in NDVI (Daum 이미지와 QuickBird 위성영상에 의한 NIR 밴드 추출과 정규화식생지수 (NDVI)에의 적용)

  • Na, Sang-Il;Park, Jong-Hwa
    • Journal of The Korean Society of Agricultural Engineers
    • /
    • v.51 no.4
    • /
    • pp.37-42
    • /
    • 2009
  • This study extracted Near Infrared (NIR) band using Image Processing Technology (IPT), and calculated Normalized Difference Vegetation Index (NDVI). Aerial photography from Daum portal in combination with high resolution satellite image was employed to improve vegetation sensitivity by extracting NIR band and calculating NDVI with comparison to QuickBird result. The extracted NIR band and NDVI through IPT presented similar distribution pattern. In addition, a regression analysis by land cover character showed high correlation paddy and forest Therefore, this approach could be acceptable to acquire vegetation environment information.

Fundamental Directions and Strategies for Resolving Local Disputes (지역분쟁 해소의 기본방향과 전략)

  • 박종화
    • Journal of the Korean Regional Science Association
    • /
    • v.12 no.2
    • /
    • pp.79-97
    • /
    • 1996
  • Local dispute resolution has evolved in response to the need for effective ways to cope with the increasing numbers and types of local disputes. Where resources are limited, where the activities of individeuals or communities affect other individuals or communities, and where interests deviate or compete, disputes are likely to emerge. Efforts to resolve local disputes vary in their particulars but generally have certain elements in common. Therefore, this study focuses upon the fundamental directions and strategies for resolving local disputes. More specifically, the purpose of this study is to examine the causes of local disputes, to suggest fundamental directions for resolving local disputes, and then to explore the strategies for resovling local disputes. In the face of rising local disputes, planners need to become more aware of the possibilities for consensual dispute than one potential path to consensus. In spite of this variability, desirable strategies in local dispute resoultion processes can be identified.

  • PDF

Estimation of Surface Temperature of the Urban Area in Cheongju Using ASTER Data (ASTER에 의한 청주시주변의 지표면온도 추정)

  • Park, Jong-Hwa;Na, Sang-Il
    • Proceedings of the Korean Society of Agricultural Engineers Conference
    • /
    • 2005.10a
    • /
    • pp.563-568
    • /
    • 2005
  • Land surface temperature (LST) for large areas can only be derived from surface-leaving radiation measured by satellite sensors. These measurements represent the integrated effect of the surface and are superior to point measurements on the ground, e.g. in Urban Heat Island. ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) is an imaging instrument that is flying on the NASA's Terra satellite launched in December 1999. ASTER acquires 14 spectral bands and can be used to obtain detailed datas of land surface temperature, emissivity, reflectance and elevation. Spatial resolution of 90m of TIR channels of ASTER is useful when we analyze the spatial variations of surface heat fluxes in urban areas. The purpose of this study is to extract the LST using ASTER TIR channels.

  • PDF

Characteristics of 10-day composite NDVI and LAI in Korea Peninsula Using NOAA AVHRR Data (NOAA AVHRR데이터를 이용한 한반도의 순별 NDVI와 LAI 특성)

  • Park, Jong-Hwa;Jun, Taek-Ki;Na, Sang-Il;Park, Min-Seo
    • Proceedings of the Korean Society of Agricultural Engineers Conference
    • /
    • 2005.10a
    • /
    • pp.649-654
    • /
    • 2005
  • This study proposes a particular approach to assess information about NDVI(Normalized Difference Vegetation Index) and LAI(Leaf Area Index) from the spectroradiometer and NOAA/AVHRR satellite data. AVHRR data were collected in twelves months over a one year period in 2004. We calculated 10-day composite NDVI using daily composite AVHRR surface reflectance products(1km spatial resolution). The 10-day composite NDVI have a great effect on the plant growth conditions. Considerably, NDVI was increased by developing muscle fiber tissue from April to May. Then the NDVI increased until the August and then decreased until February. The highest month was at August and the lower month was at December. The difference NDVI analysis using December and another months data was conducted, the results were provided information on the variation of vegetation coverage. The result suggest that a relationship established between the LAI and NDVI in 2004.

  • PDF

Korean Reference Genome Construction (한국인 고유유전체 참조표준)

  • Ryu, Je-Un;Kim, Dae-Su;Park, Jong-Hwa
    • Proceedings of the Korean Society for Emotion and Sensibility Conference
    • /
    • 2009.05a
    • /
    • pp.23-26
    • /
    • 2009
  • 한국인 최초 전체 유전체 서열(KOREF; Koreanindividualgenomesequence) 은 한국인을 위한 참조 서열로써 사용될 수 있다. 2009년 1월에 남성 한국인 유전체를 솔렉사(Solexa)를 통해 전장서열을 결정하였다. 이는 NCBI의 인간게놈프로젝트에서 생산한 게놈의 99.83%를 커버하며, 또한 NCBI게름서열의 약 20배를 커버할 정도의 유전체 서열을 결정하여 매우 높은 정확도를 가진 한국인 고유유전체이다. 한국인 유전체 서열의 분석결과 현재까지 밝혀지지 않았던 한국인 특이적인 3백만 개의 SNP를 밝혀냈다. 먼저 보고된 중국인 게놈은 한국인 게놈과 매우 가까운 민족 그룹임에도 불구하고 38%(3,186,352 SNP중에 1,217,362 SNP) 의 특이적인 차이를 나타내었으며, 또한 미토콘드리아 서열 비교를 통해서도 특이적인 다양성을 보여주는 SNP데이터를 확인 할 수 있었다. 차세대 게놈서열결정의 기술은 적은 노력과 비용으로 인간 유전체 데이터를 얻을 수 있게 되었으며, 이러한 개인유전체 데이터는 개인유전체 의학으로 가는 초석이 될 것이다.

  • PDF

A Binding Mechanisms Using One-Time Attribute Certificates (일회성 속성인증서의 바인딩 메커니즘)

  • 박종화;이상하;김동규
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.29 no.2C
    • /
    • pp.342-347
    • /
    • 2004
  • An ID certificate is digitally signed by a certificate authority for authentication and an attribute certificate is digitally signed by an attribute certificate authority for authorization. In many applications in web, there should be a mechanism to bind attributes to proper identities. The dependencies between them should be maintained. So we analyzed some known binding methods, selective revocation methods and cryptographic binding methods. And we proposed a binding mechanism using one-time attribute certificates in order to solve their problems.