• Title/Summary/Keyword: 공간 상관

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Robust Watermarking based on HVS statistics and Frequency domain (HVS 특성 및 주파수 공간 특성을 이용한 강인한 워터마킹)

  • Kim, Yoon-Ho;Park, Ki-Hong
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • v.9 no.1
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    • pp.300-303
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    • 2005
  • 본 논문에서는 디지털 멀티미디어 데이터의 저작권 보호를 위하여 웨이블릿 기반 인간 시각 시스템과 주파수 계수의 공간적 특성을 이용한 워터마킹 알고리즘을 제안하였다. 원영상을 1-Level 분해하여 HL1영역과 LH1영역을 4${\times}$4 영역으로 블록화하고 각 블록의 엔트로피와 텍스쳐 값이 가장 좋은 영역을 찾는다. 워터마크가 삽입될 영역은 상위 레벨 계수들의 상관도 특성에 따라서 3-Level 영역에 워터마크를 삽입하였다. 성능평가로 JPEG 압축, 필터링 등 워터마크된 영상에 외부공격을 가하여 워터마크 추출여부를 확인하였고, 실험결과 제안한 알고리즘은 JPEG 압축 50% 이상에서 90%이상의 상관도를 보였고, 샤프닝, 필터링 및 부분삭제 영상변형에 강인함을 보였다.

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Development of Multisite Spatio-Temporal Downscaling Model for Rainfall Using GCM Multi Model Ensemble (다중 기상모델 앙상블을 활용한 다지점 강우시나리오 상세화 기법 개발)

  • Kim, Tae-Jeong;Kim, Ki-Young;Kwon, Hyun-Han
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.35 no.2
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    • pp.327-340
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    • 2015
  • General Circulation Models (GCMs) are the basic tool used for modelling climate. However, the spatio-temporal discrepancy between GCM and observed value, therefore, the models deliver output that are generally required calibration for applied studies. Which is generally done by Multi-Model Ensemble (MME) approach. Stochastic downscaling methods have been used extensively to generate long-term weather sequences from finite observed records. A primary objective of this study is to develop a forecasting scheme which is able to make use of a MME of different GCMs. This study employed a Nonstationary Hidden Markov Chain Model (NHMM) as a main tool for downscaling seasonal ensemble forecasts over 3 month period, providing daily forecasts. Our results showed that the proposed downscaling scheme can provide the skillful forecasts as inputs for hydrologic modeling, which in turn may improve water resources management. An application to the Nakdong watershed in South Korea illustrates how the proposed approach can lead to potentially reliable information for water resources management.

Matching Points Extraction Between Optical and TIR Images by Using SURF and Local Phase Correlation (SURF와 지역적 위상 상관도를 활용한 광학 및 열적외선 영상 간 정합쌍 추출)

  • Han, You Kyung;Choi, Jae Wan
    • Journal of Korean Society for Geospatial Information Science
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    • v.23 no.1
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    • pp.81-88
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    • 2015
  • Various satellite sensors having ranges of the visible, infrared, and thermal wavelengths have been launched due to the improvement of hardware technologies of satellite sensors development. According to the development of satellite sensors with various wavelength ranges, the fusion and integration of multisensor images are proceeded. Image matching process is an essential step for the application of multisensor images. Some algorithms, such as SIFT and SURF, have been proposed to co-register satellite images. However, when the existing algorithms are applied to extract matching points between optical and thermal images, high accuracy of co-registration might not be guaranteed because these images have difference spectral and spatial characteristics. In this paper, location of control points in a reference image is extracted by SURF, and then, location of their corresponding pairs is estimated from the correlation of the local similarity. In the case of local similarity, phase correlation method, which is based on fourier transformation, is applied. In the experiments by simulated, Landsat-8, and ASTER datasets, the proposed algorithm could extract reliable matching points compared to the existing SURF-based method.

Analysis of Relationship Between LST and NDVI using Landsat TM Images on the City Areas of Jeju Island (Landsat TM 영상을 이용한 제주도 도심지역 지표면온도분포와 식생지수의 상관성 분석)

  • Quan, He-Chun;Lee, Byung-Gul
    • Journal of Korean Society for Geospatial Information Science
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    • v.17 no.4
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    • pp.39-44
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    • 2009
  • To analysis the LST distribution of Jeju island, remote sensing techniques using Landsat TM band 6 data were used. In this study, we made the LST distribution map based on the NASA. The study areas are the Jeju and Seogwipo cities of the Jeju Island. And we analyzed the correlation between the LST and NDVI which was calculated from the Landsat TM band 3 and ban 4. From the result, we found that the coefficients of the correlation were -0.77 and -0.74 on the Jeju and the Seogwipo cities, respectively. Finally, from the correlation between the land cover and LST, we also found that an inverse relationship between the LST and NDVI was exist.

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Analysis of Satellite Images to Estimate Forest Biomass (산림 바이오매스를 산정하기 위한 위성영상의 분석)

  • Lee, Hyun Jik;Ru, Ji Ho;Yu, Young Geol
    • Journal of Korean Society for Geospatial Information Science
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    • v.21 no.3
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    • pp.63-71
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    • 2013
  • This study calculated vegetation indexes such as SR, NDVI, SAVI, and LAI to figure out correlations regarding vegetation by using high resolution KOMPSAT-2 images and LANDSAT images based on the forest biomass distribution map that utilized field survey data, satellite images and LiDAR data and then analyzed correlations between their values and forest biomass. The analysis results reveal that the vegetation indexes of high resolution KOMPSAT-2 images had higher correlations than those of LANDSAT images and that NDVI recorded high correlations among the vegetation indexes. In addition, the study analyzed the characteristics of hyperspectral images by using the COMIS of STSAT-3 and Hyperion images of a similar sensor, EO-1, and further the usability of biomass estimation in hyperspectral images by comparing vegetation index, which had relatively high correlations with biomass, with the vegetation indexes of LANDSAT with the same GSD conditions.

A Study on Interrelation between Toegye′s ‘Piety’ Notion and Space of the Dosan Saudang from an Behavioral point of view (공간행태적 측면에서 본 퇴계의 ‘경’사상과 도산서당 공간의 상관성에 관한 연군)

  • 안민선;권영걸
    • Korean Institute of Interior Design Journal
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    • v.13 no.5
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    • pp.3-10
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    • 2004
  • A built space reflects its society's philosophy, culture and technology of its time period. The study explores interrelation between Toey-Gae's 'Kyung' (Piety) philosophy and architectural designs of the 'Do-San' Sau-Dang (School). Toey-Gae is a leading scholar during Chosun Dynasty who built the Do-San School to teach and showcase Sung Confucianism. He is known for his teachings and practice of 'Kyung' philosophy in all aspects of his life including his work and designs. It is also known that he personally picked and purchased the land best suited to display spirit of 'kyung' philosophy while directing the base design and construction of the building. His attentions to details are evident in his choice of city, building site, and way he arrange his designs within the natural environment. Thus, we can safely presuppose the design of Do-San Sau-Dang was created following Toey-Gae's ideology in its buildings and environment. By examining Toey-Gae's philosophy of 'Kyung' through his writings, physical location and actual designs of Do-San Sau-Dang, we can understand how this ancient philosophical ideology and thoughts were translated to a physical form and its space. The study will also explore the importance of such ideology in the society at the time and how it influenced physical and mental activities of its people.

Pattern Recognition using Two-Pupil Optical Scanning Technique and PAL-Spatial Light Modulator (Two-pupil 광학 스캐닝 기술과 PAL-공간변조기를 이용한 패턴 인식)

  • Doh, Kyu-Bong;Kim, Kwan-In;Kim, Myeong-Soo
    • Journal of Advanced Navigation Technology
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    • v.12 no.6
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    • pp.659-665
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    • 2008
  • We demonstrate experimentally that the method of Two-pupil optical scanning technique with PAL-spatial light modulator is capable of performing real-time joint transform correlation(JTC) optical system. Optical addressing is achieved by the use of a photosensitive layer of $\alpha$ - Si which controls the electric field across the liquid crystal The demonstrated technique is based on two-pupil optical heterodyne scanning. The method is independent of a spatial light modulator (SLM) in the Fourier plane. We develop the theory of the technique and evaluate a performance of the method by experimentally estimating the correlation between the target image and the reference image.

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Spatial Autocorrelation within Three Populations of Sasa borealis in Korea (한국 조릿대집단의 공간적 상관관계)

  • Huh Man Kyu
    • Journal of Life Science
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    • v.15 no.3 s.70
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    • pp.359-364
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    • 2005
  • Spatial autocorrelation was applied to microgeographic variations of Sasa borealis populations in Korea. Separate counts of each type of join (combination of genotypes at a single locus) for each allele, and for each distance class of separation, were tested for significant deviation from random expectations by calculating the Standard Normal Deviation. Moran's I was significantly different from the expected value in 25 of 150 cases $(16.7\%)$. Seven of these values $(4.7\%)$ were negative, indicating genetic dissimilarity among pairs of individuals in the ten distance classes. Populations of S. borealis are small in Korea, and are distributed with occasional cutting of seed-bearing stems used for sieves. Thus, artificial disturbance may contribute to the fact that the S. borealis population of Jirisan is unusual in lacking spatial genetic structure.

A Study on the Attribute of an Art Museum Exhibit Space by a Spectator Behavior (관람자 행태에 의한 미술관 전시공간의 특성 연구 - 전시대상과 전시공간의 상관성을 중심으로 -)

  • Yoon Jae-Eun;Kim Joo-Hee
    • Korean Institute of Interior Design Journal
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    • v.15 no.4 s.57
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    • pp.81-88
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    • 2006
  • The form and function of modern museum present more a variety of aspects in need of transition of the mature civil society and culture than the past. Considering that an art museum is the space where a multitude of unspecified visitors inspect simultaneously, exhibitions and adequate construction make visitors lead to successively visual contact. Consequently a goal of this study is to analyze that there is correlation between exhibit space and exhibitions and to suggest an alternative plan at exhibition through relationship among exhibitions, exhibit space and spectators' behavior. Two Art galleries (one is a large-sized gallery and the other is a small-sized one) located in Pyung-Chang dong were selected to analyze the correlation and suggest the better display for the exhibition. The finding of the study is following. The exhibit space which spectators recognize is assumed diverse forms by an unique characteristics of exhibits and space and an arrangement of exhibitions and the path of flow of spectator who walking ahead have an huge effect on a spectators' behavior. In other words, spectators' watching patterns are affected by display of exhibitions and the path of flow. That is to say, the spectators' behavior and the concentration to watch exhibitions is decided by the exhibit form in the museum, and the quality of watching experience is depended on the spectators' relevant knowledge prior to exhibitions.

A Study on the Propagation Characteristics of Polarization Diversity in rural and Residential Areas (교외 및 주거 지역에서의 편파 다이버시티 전파전파 특성 연구)

  • 임종태;김성진;유봉국
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.9 no.3
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    • pp.369-377
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    • 1998
  • In this paper, we performed the comparisons between polarization diversity using dual polarization antennal which has $\pm45^{\circ}$slanted linear polarization characteristics and conventional space diversity in rural and residential areas. The analysis was done by evaluating the diversity gain improvement and cross correlation coefficients between two received signals through each diversity branch. From the results, we could confirmed that space diversity has bigger diversity gain than polarization diversity by 1~2 dB, and there is a little difference of $\pm0.1$ in cross correlation coefficients by analyzing CDF under portable mobile phone environments.

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