• Journal of Korea Game Society
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• v.8 no.3
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• pp.69-76
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• 2008

This paper presents a novel rendering algorithm based on sperical coordinate representation of the object. The vertices of the object are transformed into the sperical coordinate system, and we construct additional maps: the centroid and index of the triangle, the memory access table. While OpenGL rendering pipeline touches all vertices of an object, the proposed method takes account of the only visible vertices by examining the visible triangles of the object. Simulation results demonstrated that the proposed method achieve an efficient rendering performace.

• Proceedings of the KIPE Conference
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• 2014.11a
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• pp.205-206
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• 2014

본 논문에서는 3-레벨 인버터 시스템에서 공통 모드 전압 변동 제거를 위한 새로운 Medium Vector PWM(MVPWM)을 제안한다. 제안된 MVPWM의 특징은 다음과 같다. 1) 스위칭 상태와 관계없이 공통모드 전압은 일정하게 유지된다. 2) 무게 중심좌표계 방법에 의하여 구현되므로 구현이 간단하고 직관적이다. 본 논문에서는 시뮬레이션을 통하여 제안된 MVPWM의 위와 같은 특성을 밝히고 태양광 인버터의 제어에 적합함을 입증하였다.

• Journal of the Korean Institute of Intelligent Systems
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• v.11 no.6
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• pp.487-490
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• 2001

In this paper, we realize a system that moves a cursor with a finger using the circular pattern vector algorithm that in one of the image analysis algorithms. To apply this algorithm, we use central point of the biggest circle among the various circles that recognize the image of the hand , and find out the pointing finger by looking for the distance of the outline of the hand from the central point. The horizontal direction of the cursor on the display is controlled by converting the direction of the pointing finger to the analysis of the plane corrdinate. Because of setting up only one camera of the upper, the middle and the lower discretely. On account of the discrete movement of the cursor of the vertical direction, we move th cursor to the objective, which the user wants. by expanding the local are to the whole area.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.27 no.3
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• pp.183-189
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• 2014

In this paper, a polyhedral element is presented to solve three-dimensional problems by developing shape functions based on Wachspress coordinates and moving least square approximation. A subdivision of polyhedrons into tetrahedral domains is performed for the construction of shape functions of polyhedral elements, and numerical integration of the weak form is carried out consistently over the tetrahedral domains. The weight functions for moving least square approximation are defined by solving Laplace equation with boundary values based on Wachspress coordinates on polyhedral element faces. Polyhedral elements presented in this paper have similar properties to conventional finite element regarding the continuity, the completeness, the node-element connectivity and the inter-element compatibility. Numerical examples show the effectiveness of the present method for solving three-dimensional problems using polyhedral elements.

• Journal of Korea Multimedia Society
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• v.10 no.9
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• pp.1143-1152
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• 2007

The objective of this paper is to develop the real time motion recognition method for the rehabilitation program of the people with physical disabilities. Using the infrared ray LED, this method gets the Teal time information of the user's motion and tells the difference between the information we get and the pre-defined information. In order to get the fast recognition and comparison, this method positions the specific coordinates of infrared ray LED in the pre-classified sector which keeps certain distance and angle from the point of origin. The result In our experiment shows the speed over 20 frames per second in every motion, and we are satisfied the rate for the recognition of the motions which is near 98%.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.1C
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• pp.26-35
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• 2006

In this paper, an automatic mobile robot system for a intelligent path planning using the detection scheme of the spatial coordinates based on stereo camera is proposed. In the proposed system, face area of a moving person is detected from a left image among the stereo image pairs by using the YCbCr color model and its center coordinates are computed by using the centroid method and then using these data, the stereo camera embedded on the mobile robot can be controlled for tracking the moving target in real-time. Moreover, using the disparity map obtained from the left and right images captured by the tracking-controlled stereo camera system and the perspective transformation between a 3-D scene and an image plane, depth information can be detected. Finally, based-on the analysis of these calculated coordinates, a mobile robot system is derived as a intelligent path planning and a estimation. From some experiments on robot driving with 240 frames of the stereo images, it is analyzed that error ratio between the calculated and measured values of the distance between the mobile robot and the objects, and relative distance between the other objects is found to be very low value of $2.19\%$ and $1.52\%$ on average, respectably.

• Journal of the Korea Society of Computer and Information
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• v.17 no.6
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• pp.49-55
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• 2012

Pacman is one of the world-famous and have been chosen game in the game room at the arcade. In this paper, pacman game gives you the ability to perform by simple hand movement alone. First, we obtain binary RGB image to extract skin color, and convert into binary image YCbCr by minus the luminance in this image. Next, we extract the hand region by the product of an binary RGB image and binary YCbCr image. Finally, the hand region, we obtain the center of gravity by the minimum bounding rectangle and the center of the hand pixel area, and we used to obtain the center of the hand area with an average of two center of gravity. In other words, we presented the game of motion that can take the place of arrow key by using the center coordinates of hand. In addition, these experiments showed the average movement and error rate, and cause of the error type was also investigated.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.571-575
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• 2015

This paper propose a temporal histogram -based behavior pattern analysis algorithm to analyze the movement features of moving objects from the image inputted in real-time. For the purpose of tracking and analysis of moving objects, it needs to be performed background learning which separated moving objects from the background. Moving object is extracted as a background learning after identifying the object by using the center of gravity and the coordinate correlation is performed by the object tracking. The start frame of each of the tracked object, the end frame, the coordinates information and size information are stored and managed by the linked list. Temporal histogram defines movement features pattern using x, y coordinates based on time axis, it compares each coordinates of objects for understanding its movement features and behavior pattern. Behavior pattern analysis system based on temporal histogram confirmed high tracking rate over 95% with sustaining high processing speed 45~50fps through the demo experiment.

• Radiation Oncology Journal
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• v.25 no.1
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• pp.54-61
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• 2007

[ $\underline{Purpose}$ ]: The purpose of this study is to develop a practical method for determining accurate marker positions for prostate cancer radiotherapy using CT images and kV x-ray images obtained from the use of the on- board imager (OBI). $\underline{Materials\;and\;Methods}$: Three gold seed markers were implanted into the reference position inside a prostate gland by a urologist. Multiple digital image processing techniques were used to determine seed marker position and the center-of-mass (COM) technique was employed to determine a representative reference seed marker position. A setup discrepancy can be estimated by comparing a computed $COM_{OBI}$ with the reference $COM_{CT}$. A proposed algorithm was applied to a seed phantom and to four prostate cancer patients with seed implants treated in our clinic. $\underline{Results}$: In the phantom study, the calculated $COM_{CT}$ and $COM_{OBI}$ agreed with $COM_{actual}$ within a millimeter. The algorithm also could localize each seed marker correctly and calculated $COM_{CT}$ and $COM_{OBI}$ for all CT and kV x-ray image sets, respectively. Discrepancies of setup errors between 2D-2D matching results using the OBI application and results using the proposed algorithm were less than one millimeter for each axis. The setup error of each patient was in the range of $0.1{\pm}2.7{\sim}1.8{\pm}6.6\;mm$ in the AP direction, $0.8{\pm}1.6{\sim}2.0{\pm}2.7\;mm$ in the SI direction and $-0.9{\pm}1.5{\sim}2.8{\pm}3.0\;mm$ in the lateral direction, even though the setup error was quite patient dependent. $\underline{Conclusion}$: As it took less than 10 seconds to evaluate a setup discrepancy, it can be helpful to reduce the setup correction time while minimizing subjective factors that may be user dependent. However, the on-line correction process should be integrated into the treatment machine control system for a more reliable procedure.

• Journal of the Korea Computer Graphics Society
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• v.13 no.4
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• pp.29-36
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• 2007

The objective of this paper is to develop the motion recognition method for the rehabilitation program of the people with physical disabilities. Using the infrared ray LED, this method gets the information of the user's motion and tells the difference between the information we get and the pre-defined information. In order to get the fast recognition and comparison, this method positions the specific coordinates of infrared ray LED in the pre-classified sector which keeps certain distance and angle from the point of origin. The result in our experiment shows the speed over 20 frames per second in every motion, and we are satisfied the rate for the recognition of the motions which is near 98%.