• 천문학회보
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• 제44권1호
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• pp.62.3-62.3
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• 2019

After first identification of electromagnetic counterpart of gravitational wave source (GW170817), era of multi-messenger astronomy has begun. For specifying coordinate, magnitude, and host galaxy information, optical follow-up observation of GW source becomes important. With following engineering run and O3 run of LIGO and VIRGO starting in March 2019, we present searching strategy for optical counterpart of GW source using KMTNet. 24 hours monitoring system and large field of view (4 square-degree) of KMTNet are advantage to discover a transient like GW event. By performing tiling observation of high probability area in GW localization map, we expect to observe early light-curve of GW optical counterpart. After identification, follow-up observation with various KMTNet bands and other telescopes like Gemini and UKIRT will also be performed. We will study collision mechanism, progenitor, and characteristics of host galaxy using observation data of GW source.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.997-1002
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• 2009

The local loosening of ballast supporting railway tract cause a differential vertical tract settlement. In the bridge, the temperature change make bridge deck to contract and expand, and this movement cause local loosening of ballast on the bridge expansion joint. Therefore, the evaluation of the status of ballast on the bridge expansion joint is important for the track maintenance of the high-speed railway. In this paper, hwaw method was applied to evaluate the status of ballast on the bridge expansion joint. HWAW method is non-destructive test to evaluate 2-D shear wave velocity map along the railway. Shear wave velocity is directly related with status of ballast. In this research, hwaw method was applied two different types of bridges and determine the degree and the range of the ballast loosening caused by movement of the bridge expansion joint.

• 한국정보컨버전스학회:학술대회논문집
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• 한국정보컨버전스학회 2008년도 International conference on information convergence
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• pp.93-97
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• 2008

In this letter, a novel wavelet-based semi-fragile watermarking scheme is presented which exploiting the time-frequency feature of chaotic map. We also analyze the robustness to mild modification and fragility to malicious attack of our scheme. Its application includes tamper detection, image verification and copyright protection of multimedia content. Simulation results show the scheme can detect and localize malicious attacks with high peak signal-to-noise ratio(PSNR), while tolerating certain degree of JPEG compression and channel additive white Gaussian noise(AWGN)

• 천문학회보
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• 제36권2호
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• pp.111.1-111.1
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• 2011

We present near-IR imaging polarimetry of the observed $5{\times}9$ fields (${\sim}39'{\times}69'$) in the Large Magellanic Cloud (LMC), using the InfraRed Survey Facility (IRSF). We obtained polarimetry data in J, H, and Ks bands using the JHKs-simultaneous imaging polarimeter SIRPOL. We measured Stokes parameters of point-like sources to derive the degree of polarization and the polarization position angle. We show a polarization vector map in the reduced 45 fields and the statistical distribution of the polarization degrees and angles. This poster presents the preliminary results to show the physical properties of the magnetic field in the observed LMC regions.

• 대한자원환경지질학회:학술대회논문집
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• 대한자원환경지질학회 2000년도 춘계공동학술발표회
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• pp.308-310
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• 2000

Sampling rates become inconsistent when spatial data in spherical coordinate are re-sampled with respect latitudinal or longitudinal degree for mathematical processes such as Fourier Transfrom, and this results in the distrtions of the processed data in the wavenmber domain. This distortions are more evident in the polar regions. An example is presented to show such distortions during the recovery process of free-air gravity anomalies from ERSI radar atimeter data in Russian Arctic Barents Sea, and a method is present to minimize the distortion using Lambect Conformal Conic map projection.

• The Korean Journal of Ecology
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• 제18권3호
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• pp.307-321
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• 1995

Division of ecoregions having respective functions was attempted through quantitative and qualitative analysis on vegetation diversity, and heterogeneity and on soil environment of the study sites. Field research was carried out in a square of 81 ㎢ around Andongpo (126°38'E, 37°30'N), Kimpo-gun, Kyonggi provice. Conventional methods applied are as follows: classical syntaxonomy by the Zurich-Montpellier School, interpolation method to determine the degree of diversity, heterogeneity and distribution pattern of vegetation, and correlation analysis between soil properties and plant communities. 41 plant communities were identified and composed of 6 forests, 4 mantle and 31 herb communities including 6 saltmarsh plant communities. In a mesh, number of plant communities was highly correlated to the number of species. The highest number of plant community and species was 25 communities·km-2·mesh-1 and 381 species· km-2·mesh-1 ,and the highest value of vegetation heterogeneity was 28.1 species· community-1·mesh-1. Their lowest numbers were 4 communities·km-2·mesh-1. and 28 species·km-2·mesh-1. and 7 species·community-1·mesh-1, respectively. Contour map on vegetation diversity and heterogeneity enabled us to establish two regions; coastal and inland vegetation. Isoline 〔150〕,〔10〕and〔10〕and〔15〕on the species diversity, the community diversity and the vegetation heterogeneity, respectively, were regarded as ecolines in the study area. Cl- content was recognized as the most important factor from correlation analysis between soil properties. Ordination of sites indicated that the study area be divided into two edaphic types: inland and coastal habitats. It was considered that the extent of desalinization in soil played a major role in determining the species composition in the reclamed area. By matching edaphic division of habitats with division of vegetation structures, designation of ecoregion was endorsed. The approach of current study was suggested as an effective tool to implement an assessment of the vegetation dynamics by the disparity of natural environment and anthropogenic interferences.

• 국제학술발표논문집
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.738-739
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• 2015

The main objective of this study, "Spatial Downscaling of Precipitation from GCMs for Assessing Climate Change over Han River and Imjin River Watersheds", is to carry out over Han River and Imjin River watersheds. To this end, a statistical regression method with MOS (Model Output Statistics) corrections at every downscaling step was developed and applied for downscaling the spatially-coarse Global Climate Model Projections (GCMPs) from CCSM3 and CSIRO with respect to precipitation into 0.1 degree (about 11 km) spatial grid over study regions. The spatially archived hydro-climate data sets such as Willmott, GsMap and APHRODITE datasets were used for MOS corrections by means of monthly climatology between observations and downscaled values. Precipitation values downscaled in this study were validated against ground observations and then future climate simulation results on precipitation were evaluated for the projections.

• Ecology and Resilient Infrastructure
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• 제4권4호
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• pp.237-244
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• 2017

자연침해조정제도는 개발사업에 따른 자연생태와 경관 침해를 가능한 피하거나 저감하고, 발생할 훼손 정도를 평가하여 구체적인 복원 또는 대체 방법을 강구하도록 하는 취지로 독일에서 처음 소개된 것으로 국토의 과도한 개발을 막고 지속가능한 국토관리를 위한 국토-환경계획 연동제를 효율적으로 운영할 수 있는 장점이 있다. 이에 본 연구는 과천시 주암동을 사례지역으로 도시생태현황지도를 활용하여 독일 자연침해조정 (Eingriffsregelung) 제도를 국내 실정에 맞게 수정, 보완하여 적용했다. 비오톱지도, 경관지도, NDVI (Normalized Difference Vegetation Index) 지도를 중첩 분석하여 개발사업으로 인해 훼손이 가능한 지역 중에서 비교적 생태환경적 가치가 뛰어난 지역을 도출하고 보존할 수 있는 방안을 제시했다. 도시생태현황지도의 활용을 통한 자연침해조정 제도는 국토개발에서 필연적으로 발생할 수밖에 없는 훼손의 정도를 최소화하고, 계획단계에서부터 관리할 수 있는 국토-환경정책의 정책적 연결고리로의 활용 가능함을 확인했다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1998년도 하계종합학술대회논문집
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• pp.673-676
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• 1998

Future land remote sensing satellite systems will kikely be constrained in terms of communication band-width. To alleviate this limitation, the data must be compressed. Image data obtained from satellite exhibit a high degree of spatial and spectral correlations that must be properly exploited. In this paper we propose multispectral image data compression using wavelet transform and selective predicted vector quantization. Th eproposed method is based on accuratly predicting other band from reference band and reducing bit rate through threshold map. we can achieve better compression effeciency than conventional methods.

• 한국환경생태학회지
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• 제23권2호
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• pp.161-168
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• 2009

변산반도국립공원을 대상으로 식생분포 실태를 파악하고 현존식생도 조사방법 및 작도 기준을 제시하는데 본 연구의 목적이 있다. 과거 국립공원의 식생조사문헌을 검토하고 현존식생 조사 및 작도기준안을 마련하여, 변산반도국립공원의 식생분포조사를 실시하였다. 변산반도국립공원의 현존식생은 총 8개 식물군락과 기타지역으로 구분되었으며, 2차림인 자연림은 소나무군락, 낙엽활엽수림, 굴참나무군락, 침엽수-활엽수혼효림 4개 식생군락으로, 조림지는 리기다소나무림, 곰솔림, 리기테다소나무림, 리기다소나무-곰솔림 4개 수림으로 구분되었다. 변산반도국립공원의 녹지자연도는 7등급 지역이 약 69.1%로 가장 넓었고, 9등급 지역은 0.36%로 매우 희소하였다. 국립공원의 체계적인 식생조사 및 관리를 위해서는 식생조사방법 및 작도 기준이 필요하다고 판단된다.