• Title/Summary/Keyword: spatial-correlation

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Simultaneous Estimation of Spatial Frequency and Phase Based on an Improved Component Cross-Correlation Algorithm for Structured Illumination Microscopy

  • Zhang, Yinxin;Deng, Jiajun;Liu, Guoxuan;Fei, Jianyang;Yang, Huaidong
    • Current Optics and Photonics
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    • v.4 no.4
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    • pp.317-325
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    • 2020
  • Accurate estimation of spatial frequencies and phases for illumination patterns are essential to reconstructing super-resolution images in structured illumination microscopy (SIM). In this manuscript, we propose the improved component cross-correlation (ICC) algorithm, which is based on optimization of the cross-correlation values of the overlapping information between various spectral components. Compared to other algorithms for spatial-frequency and phase determination, the results calculated by the ICC algorithm are more accurate when the modulation depths of the illumination patterns are low. Moreover, the ICC algorithm is able to calculate the spatial frequencies and phases simultaneously. Simulation results indicate that even if the modulation depth is lower than 0.1, the ICC algorithm still estimates the parameters precisely; the images reconstructed by the ICC algorithm are much clearer than those reconstructed by other algorithms. In experiments, our home-built SIM system was used to image bovine pulmonary artery endothelial (BPAE) cells. Drawing support from the ICC algorithm, super-resolution images were reconstructed without artifacts.

Moving Vehicle Detection from Single-pass Worldview-3 Imagery Using Spatial Correlation Map

  • Song, Yongjun;Chung, Minkyung;Kim, Yongil
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.40 no.5
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    • pp.439-448
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    • 2022
  • MV (Moving Vehicle) detection using satellite imagery is important for traffic monitoring and provides a wide range of observations. Specifically, MV detection methods utilizing the time lag in single-pass optical satellite images have been studied for detecting MVs from a single set of images. Because of limitations in detecting MVs outside of roads, most previous studies required road information to limit the moving object to cars on the road. However, it is difficult to obtain road information from inaccessible areas. Therefore, this study proposed a new method for detecting MVs regardless of their locations from single-pass optical satellite images without using additional data. WV-3 (Worldview-3) satellite images were used, and a spatial correlation coefficient map was proposed to detect spatial displacement which denotes MVs across two WV-3 MS images. Finally, evaluation was performed through quantitative metrics and visual inspection. The evaluation results revealed that the proposed method can detect MV movements from the single-pass satellite images. On the contrary, misdetected or undetected MVs due to radiometric differences between the images could be identified by visual inspection. The performance of the proposed method can be improved by minimizing radiometric variations and adding conditions that are robust to radiometric differences between the images.

Correlation analysis between rotation parameters and attitude parameters in simulated satellite image

  • Yun, Young-Bo;Park, Jeong-Ho;Yoon, Geun-Won;Park, Jong-Hyun
    • Proceedings of the KSRS Conference
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    • 2002.10a
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    • pp.553-558
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    • 2002
  • Physical sensor model in pushbroom satellite images can be made from sensor modeling by rotation parameters and attitude parameters on the satellite track. These parameters are determined by the information obtained from GPS, INS, or star tracker. Provided from satellite image, an auxiliary data error is connected directly with an error of rotation parameters and attitude parameters. This paper analyzed how obtaining satellite images influenced errors of rotation parameters and attitude parameters. furthermore, for detailed analysis, this paper generated simulated satellite image, which was changed variously by rotation parameters and attitude parameters of satellite sensor model. Simulated satellite image is generated by using high-resolution digital aerial image and DEM (Digital Elevation Model) data. Moreover, this paper determined correlation of rotation parameter and attitude parameters through error analysis of simulated satellite image that was generated by various rotation parameters and attitude parameters.

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Estimation Methods for Linear Spatial Model on Lattice (Lattice형 공간정보의 선형모형 추정방법)

  • Gwon, O-Ryong;Yeom, Jun-Geun
    • The Transactions of the Korea Information Processing Society
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    • v.3 no.1
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    • pp.153-159
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    • 1996
  • Linear models for spatial data are proposed by example in the paper. This method was introduced to Korea for the first time in the early part of 1990's. The correlation of spatial patterns is computed by Moran Index., and then correlogram is proposed as the method to identify correlation of spatial patterns. Due to computational difficulties with ML, an alternative estimator has been used as an eigenvalue method.

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A Numerical Study on Characteristics of Solute Transport in a Rough Single Fracture with Spatial Correlation Length and Effect of Effective Normal Stress (공간적 상관길이와 유효수직응력의 효과에 따른 거친 단일 균열내의 용질이동특성에 관한 수치적 연구)

  • Jeong, Woochang
    • Journal of the Korean GEO-environmental Society
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    • v.10 no.1
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    • pp.5-14
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    • 2009
  • This study is to analyze numerically the spatial behaviors of the solute transport in a spatially correlated variable-aperture fracture under the effective normal stress conditions. Numerical results show that the solute transport in a fracture is strongly affected by the spatial correlation length of apertures and applied effective normal stress. According to increasing spatial correlation length, the mean residence time of solute is decreased and the tortuosity and Peclet number (is a dimensionless number relating the rate of advection of a flow to its rate of diffusion) is also decreased. These results mean that the geometry of the aperture distribution is favorable to the solute transport as the spatial correlation length is increased. However, according to the applied effective normal stress is increased, the mean residence time and tortuosity have a tendency to increase but the Peclet number is decreased. The main reason that the Peclet number is decreased, is that the solute is displaced by one or two channels with relatively higher local flow rate due to the increment of contact areas by increasing effective normal stress. Moreover, based on numerical results of the solute transport in this study, the exponential-type correlation formulae between the mean residence time and the effective normal stress are proposed.

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Analysis of net radiative changes and correlation with albedo over Antarctica (남극에서의 위성기반 순복사 장기변화와 알베도 사이의 상관성 분석)

  • Seo, Minji;Lee, Kyeong-sang;Choi, Sungwon;Lee, Darae;Kim, Honghee;Kwon, Chaeyoung;Jin, Donghyun;Lee, Eunkyung;Han, Kyung-Soo
    • Korean Journal of Remote Sensing
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    • v.33 no.2
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    • pp.249-255
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    • 2017
  • Antarctica isimportant area in order to understand climate change. In addition, this area is complex region where indicate warming and cooling trend according to previous studies. Therefore, it is necessary to understand the long-term variability of Antarctic energy budget. Net radiation, one of energy budget factor, is affected by albedo, and albedo cause negative radiative forcing. It is necessary to analyze a relationship between albedo and net radiation in order to analyze relationship between two factors in Antarctic climate changes and ice-albedo feedback. In thisstudy, we calculated net radiation using satellite data and performed an analysis of long-term variability of net radiation over Antarctica. In addition we analyzed correlation between albedo. As a results, net radiation indicates a negative value in land and positive value in ocean during study periods. As an annual changes, oceanic trend indicates an opposed to albedo. Time series pattern of net radiation is symmetrical with albedo. Correlation between the two factors indicate a negative correlation of -0.73 in the land and -0.32 in the ocean.

A Study on the Typology of Spatial Organization in Art Museum (공간구성에 따른 뮤지엄 유형에 관한 연구)

  • Lee, Sung-Hoon
    • Korean Institute of Interior Design Journal
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    • v.18 no.4
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    • pp.21-30
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    • 2009
  • This study plans to classify the art museums in accordance with their spatial organization, analyzing their peculiarities each by its type in order to present the reference required for designing an art museums. With confidence, the analyzation as well as the results of the study contents will make worthy contribution for the future art museums. For this purpose, total of 95 art museums have been selected as the objects of analyzation. First of all, their types have been categorized in accordance with the standard of scale and architectural planning. Out of them, 33 museums have been further selected in order to see how the peculiarities of their patterns are outstanding, and then a quantitative analyzation has been made on each of them to see its space structure by utilizing 'Space Syntax'. Finally, a correlation analyzation of space structure peculiarities has been conducted and the spatial organization peculiarities per type is comprehensively arranged in accordance with the architectural planning and Space Syntax in order to present a new spatial organization per space to be used for the basic planning of the art museum. The contents of this analytical study are summarized as follows: A correlation analyzation on the typological features in terms of architectural planning and on the spatial organization features in terms of the Space Syntax has presented four new types of museum spaces: (1) Radial type, (2) Arachnoid-radial type, (3) Linear type, and (4) Grid type, in the light of which the selected 95 art museums have further been analyzed in order for their features to be reclassified.

Relationship between sea ice concentration and sea ice albedo over Antarctica

  • Seo, Minji;Lee, Chang Suk;Kim, Hyunji;Huh, Morang;Han, Kyung-Soo
    • Korean Journal of Remote Sensing
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    • v.31 no.4
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    • pp.347-351
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    • 2015
  • Sea ice is a key parameter for understanding the climate change in cryosphere. In this study, we investigated the correlation with the factors that influenced change of the sea ice extent. We used the Sea Ice Concentration (SIC) from Ocean and Sea Ice Satellite Application Facility (OSI-SAF), and surface albedo provided by The Satellite Application Facility on Climate Monitoring (CM SAF). We converted the same temporal and spatial resolution of the data and detected the sea ice using SIC data. We performed the relationship analysis between SIC and sea ice albedo. As a result, we found they have a strong positive correlation. We performed the linear regression between SIC and sea ice albedo, and found they have high-level coefficient of determination. It shows using either SIC or sea ice albedo is possible to estimate the sea ice products.

Application of Bias-Correction and Stochastic Analogue Method (BCSA) to Statistically Downscale Daily Precipitation over South Korea (남한지역 일단위 강우량 공간상세화를 위한 BCSA 기법 적용성 검토)

  • Hwang, Syewoon;Jung, Imgook;Kim, Siho;Cho, Jaepil
    • Journal of The Korean Society of Agricultural Engineers
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    • v.63 no.6
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    • pp.49-60
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    • 2021
  • BCSA (Bias-Correction and Stochastic Analog) is a statistical downscaling technique designed to effectively correct the systematic errors of GCM (General Circulation Model) output and reproduce basic statistics and spatial variability of the observed precipitation filed. In this study, the applicability of BCSA was evaluated using the ASOS observation data over South Korea, which belongs to the monsoon climatic zone with large spatial variability of rainfall and different rainfall characteristics. The results presented the reproducibility of temporal and spatial variability of daily precipitation in various manners. As a result of comparing the spatial correlation with the observation data, it was found that the reproducibility of various climate indices including the average spatial correlation (variability) of rainfall events in South Korea was superior to the raw GCM output. In addition, the needs of future related studies to improve BCSA, such as supplementing algorithms to reduce calculation time, enhancing reproducibility of temporal rainfall patterns, and evaluating applicability to other meteorological factors, were pointed out. The results of this study can be used as the logical background for applying BCSA for reproducing spatial details of the rainfall characteristic over the Korean Peninsula.