• Journal of the Institute of Electronics Engineers of Korea SP
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• v.42 no.5 s.305
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• pp.29-40
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• 2005

According as base of digital hologram has been magnified, discussion of compression technology is expected as a international standard which defines the compression technique of 3D image and video has been progressed in form of 3DAV which is a part of MPEG. As we can identify in case of 3DAV, the coding technique has high possibility to be formed into the hybrid type which is a merged, refined, or mixid with the various previous technique. Therefore, we wish to present the relationship between various image/video coding techniques and digital hologram In this paper, we propose an efficient coding method of digital hologram using standard compression tools for video and image. At first, we convert fringe patterns into video data using a principle of CGH(Computer Generated Hologram), and then encode it. In this research, we propose a compression algorithm is made up of various method such as pre-processing for transform, local segmentation with global information of object image, frequency transform for coding, scanning to make fringe to video stream, classification of coefficients, and hybrid video coding. Finally the proposed hybrid compression algorithm is all of these methods. The tool for still image coding is JPEG2000, and the toots for video coding include various international compression algorithm such as MPEG-2, MPEG-4, and H.264 and various lossless compression algorithm. The proposed algorithm illustrated that it have better properties for reconstruction than the previous researches on far greater compression rate above from four times to eight times as much. Therefore we expect that the proposed technique for digital hologram coding is to be a good preceding research.

• Korean Journal of Heritage: History & Science
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• v.55 no.1
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• pp.175-198
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• 2022

With the development of technology, the methods of digitally converting various forms of analog information have become common. As a result, the concept of recording, building, and reproducing data in a virtual space, such as digital heritage and digital reconstruction, has been actively used in the preservation and research of various cultural heritages. However, there are few existing research results that suggest optimal scanners for small and medium-sized relics. In addition, scanner prices are not cheap for researchers to use, so there are not many related studies. The 3D scanner specifications have a great influence on the quality of the 3D model. In particular, since the state of light reflected on the surface of the object varies depending on the type of light source used in the scanner, using a scanner suitable for the characteristics of the object is the way to increase the efficiency of the work. Therefore, this paper conducted a study on nine small and medium-sized buried cultural properties of various materials, including earthenware and porcelain, by period, to examine the differences in quality of the four types of 3D scanners. As a result of the study, optical scanners and small and medium-sized object scanners were the most suitable digital records of the small and medium-sized relics. Optical scanners are excellent in both mesh and texture but have the disadvantage of being very expensive and not portable. The handheld method had the advantage of excellent portability and speed. When considering the results compared to the price, the small and medium-sized object scanner was the best. It was the photo room measurement that was able to obtain the 3D model at the lowest cost. 3D scanning technology can be largely used to produce digital drawings of relics, restore and duplicate cultural properties, and build databases. This study is meaningful in that it contributed to the use of scanners most suitable for buried cultural properties by material and period for the active use of 3D scanning technology in cultural heritage.

• Journal of Korea Water Resources Association
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• v.56 no.6
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• pp.403-417
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• 2023

In this research, a methodology was developed for constructing an appropriate rainfall image database for estimating rainfall intensity based on CCTV video. The database was constructed in the Large-Scale Climate Environment Chamber of the Korea Conformity Laboratories, which can control variables with high irregularity and variability in real environments. 1,728 scenarios were designed under five different experimental conditions. 36 scenarios and a total of 97,200 frames were selected. Rain streaks were extracted using the k-nearest neighbor algorithm by calculating the difference between each image and the background. To prevent overfitting, data with pixel values greater than set threshold, compared to the average pixel value for each image, were selected. The area with maximum pixel variability was determined by shifting with every 10 pixels and set as a representative area (180×180) for the original image. After re-transforming to 120×120 size as an input data for convolutional neural networks model, image augmentation was progressed under unified shooting conditions. 92% of the data showed within the 10% absolute range of PBIAS. It is clear that the final results in this study have the potential to enhance the accuracy and efficacy of existing real-world CCTV systems with transfer learning.

• Sim-seong Yeon-gu
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• v.33 no.2
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• pp.141-194
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• 2018

The article is about Yong-Ho-Bi-Gyeol(龍虎秘訣), which is one of the most important Taoist text in Korea written by Jeong-Ryum, a Taoist and alchemist in the Chosun Dynasty. The article deals with the alchemical and psychological meanings of Yong-Ho (龍虎, Dragon-Tiger), the way of nurturing cinnabar (修丹之道), the closing of the qi (閉氣), the method of alchemical breathing, the Dantian (丹田, cinnabar-field), and the Mysterious Female's One Opening (玄牝一竅), in addition to the brief introduction of the life of Jeong-Ryum and the bibliography of the book. The Yong-Ho (龍虎) meaning the dragon and tiger is the archetype of transformation in the form of their opposites, rooted in the psychoid system of the human psyche. The unified Yong-Ho makes Dan and the Dan, literally indicating cinnabar, has many alchemical connotations such as Mercurius, the rubedo state of the alchemical process, and the philosopher's stone. In the book, Jeong-Ryum emphasized the slow and subtle way of breathing in and out of Dantian to develop neidan (内丹, inner cinnabar or inner alchemy). The refining of neidan begins by the closing of the qi, which symbolizes the radical introversion and withdrawal of all the projections on the outer objects. The Dantian located at the lower part of the abdomen has been known to preserve jing (精), the vital essence of life, which can be refined into qi and spirit (神). In Jungian perspective, the Dantian is a mandala where an individual's mind can stay and focus at the center of psyche detached from ego and related to the Self. The long-nurtured introverted energy makes the Mysterious Female's One Opening (玄牝一竅), a pit or cavity in the transcendental space, through which the meditator can have a relationship with the great female principle of the universe. The current article has introduced the contents of the Yong-Ho-Bi-Gyeol in the perspective of analytical psychology. However, it has not dealth with the remaining topics including Taesik (胎息, embryonic breathing) and Juchenhwahu (周天火候, the great Celestial circuit firing), due to the lack of author's sufficient knowledge and experience. The unexplored areas of Yong-Ho-Bi-Gyeol will be studied in the future.