• Journal of Korea Foundry Society
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• v.5 no.2
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• pp.109-117
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• 1985

A two dimensional analysis of the solidification phenomena has been simulated by IAD (Implicit Alternating Direction)method for L-shaped castings with external chills. The effect of chills has been studied with the variation of chill size, shape, and their materials, and also with the variation of the pouring temperature. Three kinds of cross-sectional shapes of chills such as triangle, square, and L-shape were chosen, and graphite, cast iron, and copper for their materials. It has been shown by the computation that the hot spot at the junction of L-shaped castings can not be removed by external chills, and that the distance between the inner corner and the hot spot on the line of symmetry, as well as the solidification time of castings depend only on VHC (Volumetric Heat Capacity).

• Journal of Institute of Control, Robotics and Systems
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• v.22 no.11
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• pp.883-887
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• 2016

Navigating an unknown environment is a challenging task for a robot, especially when a large number of obstacles exist and the odometry lacks reliability. Pose tracking allows the robot to determine its location relative to its previous location. The ICP (iterative closest point) has been a powerful method for matching two point clouds and determining the transformation matrix between the maps. However, in a situation where odometry is not available and the robot moves far from its original location, the ICP fails to calculate the exact displacement. In this paper, we suggest a method that is able to match two different point clouds taken a long distance apart. Without using any odometry information, it only exploits the features of corner points containing information on the surroundings. The algorithm is fast enough to run in real time.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2002.11a
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• pp.321-326
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• 2002

To design mechanical ventilation for bathroom of apartment houses where air supply and exhaust are taken Into consideration, mock-ups of ventilation systems, widely used in bathroom of apartment houses with an area of 100$m^2$, were made and installed in a laboratory, These ventilation mock-ups were available for control of air supply and exhaust, and the size of supply openings were 40cm$\times$1cm, 40cm$\times$3cm, 40cm$\times$5cm. They were installed at five positions, spaced 40cm at a height of 25cm from the floor. and the position of exhaust fans were four corners and center Exhaust fan established each one on corner of the ceiling and one in center. As result that measure ventilation effect by each condition, size of hole that supply air is big, and ventilation effect took effect to be good establishment location is low, Also, distance of exhaust fan is far with hole that supply air, ventilation effect took effect by superior thing.

• Proceedings of the KIEE Conference
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• 2003.11c
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• pp.830-835
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• 2003

This paper describes a sonic polygonal multiple reflection range sensor (SPMRS), which uses multiple reflection properties usually ignored in ultrasonic sensors as disturbances or noises. Targets such as a plane, corner, edge, or cylinder in indoor environments can easily be detected by the multiple reflection patterns obtained with a SPMRS system. Target classification and feature data extraction, such as distance and azimuth to the target, are computed simultaneously by considering the geometrical relationships between the detected targets, and finally the environment model is generated by refining the detected targets. In addition, the narrow field of view of a sonar range sensor is increased and the scanning time is reduced by active motion of the SPMRS stepping servomechanism.

• Bulletin of the Korean Chemical Society
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• v.21 no.10
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• pp.1049-1051
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• 2000

A chromia-pillared clay has been prepared by ion exchange type intercalation reaction between the sodium ion in montmorillonite and the trimeric chromium oxyformate (TCF) ion, and by subsequent heat-treatment. The structural and thermal properties have been systematically studied by thermal analysis, powder XRD, IR spec-troscopy, and XAS. The gallery height of~6.8 $\AA$ upon intercalation of the TCF ion suggests that the $Cr_3O$ plane is parallel to the aluminosilicate layers. Even though the basal spacing of TCF intercalated clay decreases slightly upon heating, the layer structure was retained up to $550^{\circ}C$ as confirmed by XRD and TG/DTA. Ac-cording to the EXAFS spectroscopic analysis, it is identified that the (Cr-Cr) distance of 3.28 $\AA$ between vertex-linked CrO6 octahedra in TCF splits into 2.64 $\AA$, 2.98 $\AA$, and 3.77 $\AA$ due to the face-, edge-, and corner-shared CrO6 octahedra after heating at $400^{\circ}C$, implying that a nano-sized chromium oxide phase was stabilized within the interlayer space of clay.

• The KIPS Transactions:PartB
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• v.17B no.1
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• pp.37-46
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• 2010

In this paper we have presented a two dimensional model based tracking system using improved chamfer matching. Conventional chamfer matching could not calculate similarity well between the object and image when there is very cluttered background. Then we have improved chamfer matching to calculate similarity well even in very cluttered background with edge and corner feature points. Improved chamfer matching is used as likelihood function of particle filter which tracks the geometric object. Geometric model which uses edge and corner feature points, is a discriminant descriptor in color changes. Particle Filter is more non-linear tracking system than Kalman Filter. Then the presented method uses geometric model, particle filter and improved chamfer matching for tracking object in complex environment. In experimental result, the robustness of our system is proved by comparing other methods.

• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.5
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• pp.1033-1039
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• 2012

In this paper, a simple and robust algorithm is proposed for detecting each steel plate from a image which contains several steel plates. Steel plate is characterized by line edge, so line detection is a fundamental task for analyzing and understanding of steel plate images. To detect the line edge, the proposed algorithm uses the small eigenvalue analysis. The proposed approach scans an input edge image from the top left corner to the bottom right corner with a moving mask. A covariance matrix of a set of edge pixels over a connected region within the mask is determined and then the statistical and geometrical properties of the small eigenvalue of the matrix are explored for the purpose of straight line detection. Using the detected line edges, each plate is determined based on the directional information and the distance information of the line edges. The results of the experiments emphasize that the proposed algorithm detects each steel plate from a image effectively.

• Journal of KIISE:Software and Applications
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• v.27 no.7
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• pp.712-722
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• 2000

In this paper, we suggest and test a classification technique of offence pattern from group formation to automatically index highlights of soccer games. A BP (Back-propagation) neural nets technique was applied to the information of the position of both the player and the ball on a ground, and the distance between the player and the ball to identify the group formation in space and time. The real soccer game scenes including '98 France World Cup were used to extract 297 video clips of various types of offence patterns; Left Running 60, Right Running 74, Center Running 72, Corner-kick 39 and Free-kick 52. The results are as follows: Left Running comes to 91.7%, Right Running 100%. Center Running 87.5%, Corner-kick 97.4% and Free-kick 75%, and these showed quite a satisfactory rate of recognition.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.47 no.2
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• pp.91-98
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• 2021

Objectives: Hyaluronoglucosaminidase (hyaluronidase) increases the local intercellular permeability of the peripheral lymphatic channel and capillaries, which may help reduce edema. In the present study, the effects of hyaluronidase on postoperative edema and pain reduction were evaluated. Materials and Methods: The study included 38 patients who underwent guided bone regeneration (GBR) surgery before implantation. Patients were randomly assigned to either the control group (n=20) or the test group (n=18). Hyaluronidase was injected into the GBR site of subjects in the test group. Postoperative edema was evaluated by measuring the distance between specific facial landmarks immediately after surgery (T1) and 2-4 days after surgery (T2). The degree of pain at T2 and at 10-14 days after surgery (T3) was assessed. Results: In the test group, the degree of swelling was lower than in the control group, however, only two measurements, from the tragus to the mouth corner and from the outer canthus to the mouth corner, showed statistically significant differences (P=0.012 and P=0.001, respectively). The anti-edema effect of hyaluronidase was more effective in the maxilla than in the mandible. In the maxilla, the percentage of facial swelling was significant for three measurements. However, in the mandible, the percentage of facial swelling was significant for only one measurement. Low levels of pain that were similar at T2 and T3 were reported in both groups. Conclusion: The results indicate the degree of swelling was lower in the test group and hyaluronidase appeared to be more effective in the maxilla. The degree of pain reduction was similar between groups. Further in vivo and randomized controlled trials with larger sample sizes are warranted.

• Journal of the Korean Association of Geographic Information Studies
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• v.10 no.4
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• pp.1-13
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• 2007

We make image that accumulate two principal component after change picture to use GLCM(Gray Level Co-Occurrence Matrix)'s texture feature information. And then these images use preprocess to achieved corner detection and area detection. Experiment results, two principle component conversion accumulation images had most informations about six kind textures by Eigen value 94.6%. When compared with red tide area that uses sea color and red tide area of image that have all principle component, displayed the most superior result. Also, we creates Euclidian space using Euclidian distance measurement about red tide area and clear sea. We identify of red tide area by red tide area and clear sea about random sea area through Euclidian distance and spatial distribution.