• Transactions of the Korean Society of Mechanical Engineers
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• v.14 no.6
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• pp.1523-1532
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• 1990

The objective of this study is to develope an optimized multi-facet drill (MFD). The principal factors that affect drilling performance are its geometry and the cutting conditions. In particular, the helix angle in the total twist angle of the twist drill, affects much morgen influence on the dynamic and static stiffness and on determining the characteristics of the chip disposal capacity of the drill. In this study, considering the helix angle as a major parameter, the model was developed. From this model, the deformation of transverse direction was simulated with the bending forces applied. The performance of a drill largely depends upon drilling forces. Comprehensive models for predicating the drilling thrust and torque are developed for the different drill geometries. The effects of MFD geometric parameters on thrust and torque are also deduced from the prediction models, from which an optimal drill geometry is found with the emphasis on minimum drilling forces.

• Korean Journal of Cognitive Science
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• v.18 no.4
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• pp.445-455
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• 2007

We present a new biometric identification system based on multi-view features of teeth using principal components analysis(PCA). The multi-view features of teeth consist of the frontal view, the left side view and the right side view. In this paper, we try to stan the foundations of a dental biometrics for secure access in real life environment. We took the pictures of the three views teeth in the experimental environment designed specially and 42 principal components as the features for individual identification were developed. The classification for individual identification based on the nearest neighbor(NN) algorithm is created with the distance between the multi-view teeth and the multi-view teeth rotated. The identification performance after rotating two degree of test data is 95.2% on the left side view teeth and 91.3% on the right side view teeth as the average values.

• Journal of Digital Convergence
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• v.15 no.12
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• pp.531-541
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• 2017

Realistic videos using multi-view videos are created so that the contents shown on multi-view displays or screens look realistic. These images have been mostly used for special videos for exhibition, but, recently, systems such as Screen X have given rise to multi-view images as a format for storytelling contents such as movies. This study used HD-level broadcasting digital video camera with three zoom lenses for shooting wide to close-up shots focusing on a person, in the same way as Screen X, and identified and analyzed problems found during multi-view image registration correction. The results of this study suggested, provided the shooting technique and equipment are improved, the multi-view format can be used for conveying stories and information. Future research will need to investigate and supplement relevant techniques that will enable production of high-quality multi-view image contents by using a cinema-grade camera with standard lenses, instead of using broadcasting-grade zoom lenses.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.05a
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• pp.529-530
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• 2014

Multiplanar image video has been used in various fields advertising, exhibitions, and PR. But the content is applied therein, image synthesis, and graphics in most cases. That for taking pictures become a stock video exactly not only very difficult, to complement work in the second half of the problems of the shooting stage is difficult. Therefore, in this study, and then grasp the problems later work with imaging and attempts to validate the experiment improvements. As the study specific method, it is intended to advance the experiments for determining the distance to minimize the distortion generated at the edges of the image varies with the distance between cameras. It is intended to contribute to the creation of the content of the image-based, which can be utilized more effectively excellence media of the video if to build on this.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.1
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• pp.1157-1160
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• 2005

본 논문에서는 레이저 다이오드(Laser Diode, LD)를 배열시키고 회전 다면경(Polygon Mirror)의 반사각 및 회전다면경의 기하학적 프로젝션 시스템 설계를 통하여 2D-레이저 프로젝션 시스템을 구현하였다. 제안한 회전다면경과 레이저 다이오드 배열을 적용하석 영상 동기 시켜 레이저 배열을 적용한 레이저 디스플레이 시스템을 최종적으로 설계하고 실제 제작을 통해서 시스템을 검증하였다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.10a
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• pp.52-52
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• 2003

• Journal of Digital Convergence
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• v.14 no.3
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• pp.419-425
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• 2016

This paper was to explore the effects of multiphasic components of home environment on life satisfaction. This survey was conducted from September, 2015 to November, 2015 and 298 responses from the survey were used for the analysis. The data was analyzed by descriptive statistics, t-test, ANOVA, pearson correlation and Multiple Regression. The research findings could be summarized as the followings. First, each of the elements of home environment was generally recognized as average level. while, the mean score of privacy was higher than average. Second, privacy, economics, high income and good health were the significant predictors to explain life satisfaction. In conclusion, privacy and economics among the multiphasic components of home environment were major variables that affect life satisfaction.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.3
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• pp.261-272
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• 2008

This study was conducted to provide the fundamental data based on the agronomic characteristics of domestic aroma rice, widely cultivated domestic rice and foreign aroma rice for breeding of functional aromatic rice. Among the 104 varieties, all of domestic aroma rice and widely cultivated rice varieties were headed, 24 of 84 varieties of foreign aroma rice were not headed. The average heading date of domestic aroma rice Japonica types of domestic rice was later as 136 day, and Tongil types of domestic aroma rice were faster as 122 day. The average culm length of Indica types of foreign aroma rice was longer as 130 cm, and Tongil types of were shorter as 74 cm. The average panicle length of domestic aroma rice and traditional rice were about 21 cm, and Indica types of foreign aroma rice were longer as 29.5 cm. The average 1,000 grain weight of Tongil types of domestic aroma rice and was not a difference with the domestic aroma rice and was more 2.5 g than the Indica types of foreign aroma rice. The average ratio of grain width and length of Indica types of foreign aroma rice were highest as 3.29 (W/L), and the domestic traditional rice was lowest as 1.7 (W/L). The average fertility rate of the domestic aroma rice, the widely cultivated domestic rice, and the Japonica types of foreign aroma rice were above 89.7%, but the Indica types of foreign and the Tongil types of domestic aroma rice were below 65.4%. The average germination rate of foreign aroma rice were above 83.7%, and domestic aroma rice were above 90.4%. The non-glutinous rice were 64 varieties (84.2%) of total 104 accessions of material rice and the waxy rice were 7 varieties (1%). In the domestic aroma rice, Hyangmi2ho and Aranghyangchalbyeo has a mild aroma grade. In the foreign aroma rice, 22 of 40 varieties of Indica types and 9 of 16 varieties of Japonica types has a lightly aroma grade. And 13 varieties of widely cultivated domestic rice has a non-aroma grade.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.8 no.2
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• pp.46-52
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• 2009

Drilling operation is such an important machining process, which has been wildly applied to the industry, occupied over 30% of whole industry. However, there are many aspects of drilling process should be improved, such as increases of thrust force, surface roughness, and roundness, ect. In this study, we are aiming to reduce the thrust force, surface roughness, and roundness in drilling process. For this purpose, multi facet drills (MFD) of three types that are modified from standard drill (STD) are developed. The first type is multi stair drill (MSD) with shape of stair on relief plane. The second type is rough facet drill (RFD) with shape of round on relief plane. The third type is rough flute drill (RFLD) with shape of round on flute plane. For three types of MFD, we were carried out performance evaluation from the perspective of thrust force, surface roughness and roundness of machined hole. From obtained result, we could confirmed that performance of rough flute drill (RFLD) type is most excellent.

• Korean Journal of Optics and Photonics
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• v.6 no.1
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• pp.21-25
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• 1995

Q-switched Waveguide $CO_{2}$ laser using polygon mirror were constructed and their output characteristics were measured. Waveguide was made of the beryllium oxide tube of inner diameter of 2 mm, outer diameter of 20 mm, and length of 200 mm. A flat ZnSe output coupler of 80% reflectivity was placed on the 9 mm distance from the end of the waveguide. Convex lens was used to reduce the coupling loss between the polygon mirror and the waveguide. The polygon mirror was located behind of convex lens. With this condition, continuous output of the laser were measured as 1.2 W. In the Q-switched mode. pulse width 120 ns were measured with rotational speed 7,559 RPM. and peak power of up to 250 W. 250 W.