• The Bulletin of The Korean Astronomical Society
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• v.37 no.1
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• pp.52.1-52.1
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• 2012

It is often said that there is little geometrical mind in Korean history. However, a method to project the surface of a sphere onto 2-dimensional plain was applied to the representative Korean star chart or Cheonsang Yeolcha Bunyajido (天象列次分野之圖). The method, called the equi-distant polar projection, was explained in detail in ancient Chinese history book of the Tang dynasty, which was originated from older history. Another method of the Mercator projection was introduced by the famous engineer Su Song (蘇頌) of the Song dynasty. The description has quite geometrical thoughts, especially the concept of infinity or convergence appears, However, this type of sky projection method was not widely used in east Asia. When the European Jesuits came to China to evangelize the Chinese people, they found that the Chinese people paid much attention to advanced European astronomical knowledge. Thus, they introduced the European astronomical knowledges into China, and the star chart was one of them. The projection method of the new charts were quite different from the Chinese tradition. When the Koreans brought those new star chart from China, they must have known the geometrical description of the method. The method was described in detail in a volume of Chongzhen Lishi (崇禎曆書) or Xiyang Xinfa Lishu (西洋新法曆書). The explanation consists of three part. One is the quantitative way; another is a geometrical way using axiomatic systems; and the other is the practical method to draw star chart with the geometical projection. However, when we see the Honcheon Jeondo (渾天全圖) that is thought to be duplicated by Kim Jeongho (金正浩), the new geometrical method was not so widely known to the Koreans. I will discuss the reason why the geometrical minds have not been widely adopted in the Korean civilization.

• Journal of The Korean Astronomical Society
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• v.29 no.spc1
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• pp.433-437
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• 1996

We have analyzed the content of the Korean stone star chart. Ch'on-Sang-Yul-Cha-Bun-Ya-Ji-Do(here-after Ch'on-Sang-Do). In the star map we have found 1468 stars, 4 more than the Chinese star catalog Bo-Chun-Ga. The four extra stars form a constellation, Jong Dae Boo. The map projection law used in the star chart is found to be the polar equtorial and equidistance projection. The linear distance of an object on Ch'on-Sang-Do from the center is linearly proportional to the north polar angular distance. We have found from a statistical analysis that most stars with declination lower than 50 are at positions representing the epoch of around the first century. On the other hand, stars near the north pole with declination higher than 50 are at the epoch of about 1300, which is close to the time the chart was engraved. This implies that the original Ko-Gu-Rye Dynasty's star chart has been revised by astronomers of Cho-Sun Dynasty. We have also shown that stars on Ch'on-Sang-Do are engraved in such a way that their area is linearly proportional to the visual magnitude.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.11 no.2
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• pp.55-65
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• 2008

This study was surveyed to analyze vegetation structure of mountainous wetlands in Chung-ju city and around area from September to November, 2006. 6 sites of total 15 potential mountainous wetlands were discriminated throughout field survey. By classification system of mountainous wetlands presented in manual of forest wetlands research, types of wetlands were classified into slant and a flat. Many sites were covered with land plants as Pueraria thunbergiana and so on. To understand vegetation structure of mountainous wetlands, Height, DBH (diameter at breast height), DI (Dominance Index), Sociability and Constancy were surveyed and Based on this result, a projection chart was drawn. As results, Salix koreensis in tree layer and Persicaria thunbergii and Impatiens textori in herb layer were surveyed as broadly distributed species. This study is mainly focused on vegetation condition of mountainous wetlands. But, it will be needed studying on classification system of mountainous wetland type and functional assessment for conservation or management of wetlands.

• Archives of Plastic Surgery
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• v.38 no.4
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• pp.401-407
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• 2011

Purpose: A number of flap for nipple reconstruction have been well described in the literature. However, most of these techniques do not permit the reconstruction of a projecting nipple and all are hampered to some extent by long-term loss of nipple projection. The objective of this study is to evaluate the long-term result and clinical efficacy of nipple reconstruction using skate flap technique after breast reconstruction. Methods: A retrospective chart review was carried out on 23 patients who underwent 25 nipple reconstructions. In those patients with greater than 10 mm nipple projection, reconstruction with skate flap and full-thickness skin graft and/or tattooing was performed. Maintenance of nipple projection was then carefully assessed over one-year follow-up. The following factors were analyzed: type of breast reconstruction, type of areola reconstruction, followup period, decrease in nipple projection, complication, and whether secondary nipple reconstruction was necessary and/or performed. Results: Breast reconstructions were performed in 17 patients with free transverse rectus abdominis musculocutaneous flap, 3 patients with extended latissimus dorsi musculocutaneous flap, and 3 patients with expander and implant. The mean follow-up after nipple reconstruction was 17 months. Mean loss of projection were $17.0{\pm}13.99%$, $25.0{\pm}12.70%$, $30.0{\pm}12.57%$ and $30.8{\pm}12.49%$ at 3, 6, 9 months and over one year, respectively. The greatest decrease in projection was noted in the first 3 months following surgery. Conclusion: These results indicated that nipple reconstruction with skate flap showed about 70 percent of the projection achieved over one year postoperation. Therefore, the skate flap may be a reliable method of nipple reconstruction in those patients with greater than 10 mm nipple projection.

• Journal of Navigation and Port Research
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• v.29 no.3 s.99
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• pp.269-274
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• 2005

Geodetic surveying using precise GPS equipment are used without analysis with a statistical verification of GPS observed value and it was preformed by necessity to integration projection of digital topographic map and nautical Chart for integration geographic information system construction. The purpose of this study proposes method that improve accuracy of GPS observed value and direction that integrally manage digital topographic map and electronic nautical chart in analyzing the boundary line error between digital topographic map and nautical Chart. For improvement of the precision of GPS observed value, the author studied precision-analysis of GPS observed value by geometric strength and variance factor in 3 control points used in GPS network adjustment. And like this, produce EDM measurement using this GPS observation results and compare the whole boundary point error when set digital topographic map and nautical chart by these boundary.

• Proceedings of the IEEK Conference
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• 2004.08c
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• pp.823-826
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• 2004

In this paper, A tracking of the moving objects using normalized hue distribution in HSI color model was proposed. Moving objects are detected by using difference image method and integral projection method to background image and objects image only with hue area. Hue information of the detected moving area are normalized by 24 levels from $0^{\circ}$ to $3600^{\circ}A$ distance in between normalized levels with a hue distribution chart of the normalized moving objects is used for the identity distinction feature parameters of the moving objects. To examine proposed method in this paper, image of moving cars are obtained by setting up three cameras at different places every 1 km on outer motorway. The simulation results of identity distinction show that it is possible to distinct the identity a distance in between normalization levels of a hue distribution chart without background.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2004.05b
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• pp.591-594
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• 2004

In this paper, The identity distinction of the moving objects using distance among hue normalization levels was proposed. Moving objects are detected by using difference image method and integral projection method to background image and objects image only with hue area. Hue information of the detected moving area are normalized by 24 levels from 0$^{\circ}$ to 360$^{\circ}$. A distance in between normalized levels with a hue distribution chart of the normalized moving objects is used for the identity distinction feature parameters of the moving objects. To examine proposed method in this paper, image of moving cars are obtained by setting up three cameras at different places every 1 km on outer motorway. The simulation results of identity distinction show that it is possible to distinct the identity a distance in between normalization levels of a hue distribution chart without background.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.04a
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• pp.275-281
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• 2004

Geodetic surveying using precise GPS equipment are used without analysis with a statistical verification of GPS observed value and it was preformed by necessity to integration projection of digital topographic map and nautical Chart for integration geographic information system construction. The purpose of this study proposes method that improve accuracy of GPS observed value and direction that integrally manage digital topographic map and electronic nautical chart in analyzing the boundary line error between digital topographic map and nautical Chart. For improvement of the precision of GPS observed value, the author studied precision-analysis of GPS observed value by geometric strength and variance factor in 3 control points used in GPS network adjustment. This study compare the whole boundary point error When producing EDM measurement using this GPS observation results and setting digital topographic map and nautical chart by these boundary.

• Korean Journal of Digital Imaging in Medicine
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• v.13 no.4
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• pp.145-151
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• 2011

The purpose of this study is to know some changes of resolution and image if we remove scattered ray using lead plate when doing lumbar lateral projection. Using 3 DR system(2 FD types, 1 CCD type) equipments and 2 film system equipments, we gain the image whether the phantom of abdomen equivalent sticking resolution chart has lead plate or not, whether we do collimation or not. Also, we use ion chamber, measure radiation exposure rate and change to entrance surface dose from it. we gain that images in the greatest condition of taking in clinic. 5 people in this group decoded resolution with our eyes, measured thickness of images and compared them from each equiments. Resolution has difference to size of collimation in DR FD type. Also there is no difference the original image with the new image which we abbreviated mAs. In DR CCD type, resolution didn't have difference whether lead plate is or not and whether we do collimation or not. In film type, existing or nonexisting of lead plate didn't influence on resolution. Lead plate makes the quality of image higher due to reducing scattered ray, it doesn't influence on resolution.

• Publications of The Korean Astronomical Society
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• v.34 no.1
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• pp.1-16
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• 2019

"Hon-Chon-Jeon-Do" is a woodcut star map with the size of $79.4cm{\times}127.5cm$, and was widely disseminated as it was made into a set with Kim, Jung Ho's "Yeoji-Jeon-Do". This study confirmed that Yixiang kaocheng xubian ("의상고성속편") star catalogue was used as a source to produce the star map, and the stereographic projection was applied with the projection center being the mid-point (Q) between the celestial and ecliptic north poles. The 'mid-circle' around the Q is arisen between the equator and the ecliptic, and on this circle, the hour angle and the ecliptic longitude of a star can be marked using the same scale. This means that the hour of the day and the season of the year can be read on the same dial of the mid-circle, and the application of this character in the practical use was the key point of the star map production. By observing either transits or positions of the 28 xiu (宿), it is easy to find the corresponding season and time by simply reading the dial on the mid-circle. This is just the function of a portable almanac and thus by disseminating it widely, the convenience of the people would have been promoted. For this reason, it can be stated that "Hon-Chon-Jeon-Do" was a practical astronomical tool which was produced by the western astronomical projection method and was used to find time and season. Choi, Han Ki and Kim, Jung Ho are strong candidates for the makers of this star map. The time of production is estimated to be 1848 ~ 1857, and "Hon-Chon-Jeon-Do" could be regarded as a good contributor to popularization of astronomy in the late Joseon Dynasty.