• Korean Journal of Remote Sensing
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• v.37 no.4
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• pp.687-698
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• 2021

We present quantitative estimations of changes in the areal extent of coral reef habitats at Weno Island, Micronesia, using high-spatial-resolution remote sensing images and field observations. Coral reef habitat maps were generated from Kompsat-2 satellite images for September 2008 and September 2010, yielding classifications with 78.6% and 72.4% accuracy, respectively, which is a relatively high level of agreement. The difference between the number of pixels occupied by each seabed type was calculated, revealing that the areal extent of living corals decreased by 8.2 percentage points between 2008 and 2010. This result is consistent with a comparison of the seabed types determined by field observations. This study can be used as a basis for remediation planning to diminish the impact of changes in coral reefs.

• Fashion & Textile Research Journal
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• v.18 no.4
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• pp.477-488
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• 2016

This study classified and analyzed the types of images posted on official accounts operated by domestic and foreign SPA brands on Instagram and Pinterest, which are image-based fashion curations, and performed a survey on preferred image types in the fashion curations of SPA brands. It aims to induce active apparel purchasing behavior of consumers through the suggestion of image types about fashion curations for effective communication between fashion brands and consumers. The survey to targets the 20s and 30s was carried out from October 23, 2015 until November 22 and conducted factor analysis, paired t-test. The above images were classified into four types based on previous studies: product images, brand images, lifestyle images, multiple images. The results of the survey were also divided into four factors in line with the classification of image types. Generally, foreign SPA brands(H&M, Uniqlo, Zara) used image-based fashion curation services more frequently than domestic SPA brands(8Seconds, Mixxo, Spao, Tngt). The analysis of image types in the fashion curations of SPA brands showed that product images accounted for the highest proportion of images used in the official accounts of SPA brands. However, the comparison of averages on the preferred image types of survey respondents showed that the users who had once visited the official accounts of SPA brands on Instagram and Pinterest preferred in the order of lifestyle information > product information > brand information > multiple information provided by SPA brands, which was statistically significant.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2003.10a
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• pp.187-192
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• 2003

of the road would be a key index judged for a safety at the vehicle driving on the road. In Korea, as seen through a lot of documents, the vehicle driving speed is much faster compared with the design speed. The vehicle driving speed is an important element to get to know the vehicle driving characteristics. However, it is not easy to obtain the vehicle driving speed relating to vehicles' consecutive movements just merely through the presently used methods of vehicle driving speed. In consequence, this study has conducted photographing vehicle movements by use of digital moving images. Based on digital moving Images pictured, we have obtained a certain time interval frame and extracted out vehicles' coordinates and calculated vehicle speed from the firstly rectified image and the secondly rectified image. We could obtain comparatively exact results in the calculation of vehicle driving speed as errors of about 4%, as a result of comparison and verification of vehicle speed calculated from the digital moving images and the speed obtained from DGPS.

• Proceedings of the Optical Society of Korea Conference
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• 2003.07a
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• pp.80-81
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• 2003

The psychophysical experiments were carried out by a panel of eleven observers on the image difference pairs displayed on the LCD (liquid crystal display)to quantify the quality changes of complex images imparted by the typical image processing operations. There were six different kinds of pairs according to their original image. The three types of visual tests performed were： pair-to-pair comparison of image differences for ordering the differences between images introduced by single or combination of image lightness change, contrast change, blurring, and sharpening, perceptibility and acceptability tests using ascending or descending series of image difference pairs ordered according to the size of their visual differences. (omitted)

• Journal of the Korea Institute of Information and Communication Engineering
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• v.2 no.4
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• pp.619-626
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• 1998

This paper presents the features for quantitative evaluation of medical images based on the technique of image processing. In consideration of advice from medical doctor, 1 derive three features seemed to be strongly correlated with the degree of disease's advance. From comparison between each feature and evaluation value by medical doctor, our research shows that three features can be a useful aids in quantitative evaluation of lung's disease on chest X-ray images.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.16 no.3
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• pp.171-177
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• 2004

A new wave gauge using digital image of waves is developed and the performances are tested by wave tank experiments. This wave gauge uses frame frequency of 1/15 sec, conversion of analog images to digital images, and large capacity of hard disk. This wave gauge measures wave heights by detecting the buoy movement automatically from the image, where the buoy moves with the same phase of water surface. The comparison of automatic measurements of wave heights to the true data is reasonable. The wave gauge can be improved to measure wave heights on shallow waters near shorelines.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.2
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• pp.722-733
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• 2012

Recently various studies on various applications using images taken by mobile phone cameras have been actively conducted. This study proposes a correction method for misrecognition of Korean Texts in signboard images using improved Levenshtein metric. The proposed method calculates distances of five recognized candidates and detects the best match texts from signboard text database. For verifying the efficiency of the proposed method, a database dictionary is built using 1.3 million words of nationwide signboard through removing duplicated words. We compared the proposed method to Levenshtein Metric which is one of representative text string comparison algorithms. As a result, the proposed method based on improved Levenshtein metric represents an improvement in recognition rates 31.5% on average compared to that of conventional methods.

• Journal of the Korean Institute of Telematics and Electronics
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• v.23 no.6
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• pp.961-967
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• 1986

A technique of optical image synthesis with an extended incoherent source is presented and compared with the coherent method. A holographic diffraction grating is fabricated by using Michelson interferometer, and by equalizing the 8th-order to the 2nd-order diffraction efficiency, complex amplitude addition and subtracdtion of optical images are simultaneously realized. The experiment shows that the quality of synthesized optical images in the incoherent method is improved in comparison with that of the coherent method by suppressing the coherent artifact noise.

• Proceedings of the KSRS Conference
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• 2008.10a
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• pp.240-242
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• 2008

In the present article, we analyze airborne Pi-SAR (Polarimetric-Interferometric SAR) X-band images of ocean waves around the Miyake Island at approximately 180 km south from Tokyo, Japan. Two images of a same scene were produced at approximately 40 min. interval from two directions at right angles. One image shows dominant range travelling waves, but the other image shows a different wave pattern. This difference can be caused by the different image modulations of RCS and velocity bunching. We have estimated the dominant wavelength from the image of range waves, and from the wave phase velocity computed from the dispersion relation (though no wave height data were available), the image intensity is computed by using the velocity bunching model. The comparison of the result with the second image at right angle strongly suggests the evidence of velocity bunching.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.2
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• pp.102.2-102.2
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• 2011

Sunspots usually appear in a group which can be classified by certain morphological criteria. In this study we examine the moments which are statistical parameters computed by summing over every pixels of contours, in order to quantify the morphological characteristics of a sunspot group. The moments can be additional characteristics to the sunspot group classification such as McIntosh classification. We are developing a program for image processing, detection of contours and computation of the moments using continuum images from SOHO/MDI. We apply the program to count the sunspot numbers from 303 continuum images in 2003. The sunspot numbers obtained by the program are compared with those by SIDC. The comparison shows that they have a good correlation (r=89%). We are extending this application to automatic sunspot classification (e.g., McIntosh classification) and flare forecasting.