• Communications of Mathematical Education
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• v.18 no.2 s.19
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• pp.289-294
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• 2004

제 7차 수학과 교육과정에서 벡터는 수학 II에서 다루며, 삼각함수, 좌표와 함께 도형의 성질을 대수적으로 탐구하는 중요한 도구이다. 본 연구에서는 벡터 개념을 이용하여 볼록 n각형의 무게중심의 성질을 탐구하고, 이를 바탕으로 '볼록 n각형에서 n개의 중선은 한 점에서 교차하며 교점은 각 중선을 (n-1):1로 나눈다'는 것을 벡터를 이용하여 증명하였다.

• 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.

• Communications of Mathematical Education
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• v.25 no.4
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• pp.681-691
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• 2011

Mathematics curriculum according to 2009 Revised National Curriculum suggests that school mathematics must cultivate interest and curiosity about mathematics in addition to creative thinking ability of students, and ability and attitude of observing and analyzing many things happening around. Centroid of a triangle in 2007 Revised National Curriculum is defined as 'an intersection point of three median lines of a triangle' and it has been instructed focusing on proof study that uses characteristic of parallel lines and similarity of a triangle. This could not teach by focusing on the centroid itself and there is a problem of planting a miss concept to students. And therefore this writing suggests centroid must be taught according to its essence that centroid is 'a dot that forms equilibrium', and a justification method about this could be different.

• Nuclear industry
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• v.35 no.6
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• pp.50-53
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• 2015

현재 세계 원자력 발전 산업의 무게 중심은 동아시아로 옮겨졌다. 공통적으로 대도시들을 가지고 있는 중국, 일본, 한국, 그리고 대만은 화석연료에 대한 의존율을 낮추기 위해 원자력 에너지를 사용하고 있지만 각국의 원전프로그램 사이에는 적지 않은 차이점이 존재하고 있다.

• Korean Journal of Applied Biomechanics
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• v.18 no.1
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• pp.159-168
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• 2008

The purpose of this study was to analyze the variables of plantar pressure distribution, the COG between Flying Sit Spin(FSS) and Flying Camel Spin(FCS) during a Figure Skating. In order to investigate the two types of spin mechanism in the Korea national of elite women Figure skaters(N=4), this study investigated the phase time, CA(contact area), MF(maximum force) Mean Force, and PP(peak pressure) Mean Force. The data was collected using PEDAR Mobile System which is the pressure distribution measuring devices. The obtained conclusions were as follow: During the two types of spins(FSS and FCS), the FCS is higher than the FSS on the MF(20%BW), PP(20%BW) variables during P4 phase, but the FSS is larger than the FCS in the CA, MF, and PP during P1, P2, P3 phase. Consequently, depend on the COP and the COG locations about the vertical ground reaction vector, the FCS comparatively excelled control of speed feedback than the FSS in the P4 phase.

• Proceedings of the KIEE Conference
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• 2003.07d
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• pp.2462-2464
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• 2003

본 논문에서는 비젼 기반의 마이크로매니퓰레이션을 위해서 임의의 형태의 오브젝트에서 조작점을 추출하는 알고리듬을 제안한다. 본 알고리듬은 무게 중심점과 K-L 변환을 이용하여 오브젝트의 조작점을 선정하고 오브젝트와 마이크로 그리퍼가 접촉하게 되는 면에서 최외곽의 접점을 접촉점으로 선정한다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.3
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• pp.2012-2019
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• 2015

This study examined the changes in the center of pressure (COP) and cadence according to three types of bags carried and three different bag weights. The experimental period was from June 3, 2013 to January 20, 2014, and thirty eight healthy adults (mean age: $26.10{\pm}5.32$ years, age range: 22-30 years) volunteered under three conditions. In the first condition, the subjects wore a bag over one shoulder and they walked. In the second condition, they carried a bag across the shoulder and walked. With the third condition, they carried a backpack using both shoulders and walked. 3-Dimentional motion analysis system and a force plate were used to measure the kinematic parameters of gait and COP displacement during gait. Each subject walked 6 meters carrying a 3kg, 5kg and 7kg bag under all three conditions. The COP of the antero-posterior and medio-lateral, and cadence variable were significantly different according to the bag weight of 3kg, 5kg and 7kg. These findings suggest that walking while carrying a backpack using both shoulders is more effective on the changes in COP and gait of adults than the other conditions.

• Proceedings of the KAIS Fall Conference
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• 2010.11a
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• pp.88-91
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• 2010

최근 무선통신 기술의 발당과 인터넷의 발달로 웹캠을 활용하여 얼굴인식, 몸동작 인식, 제스처 인식 등의 연구가 활발히 진행되고 있다. 본 연구에서는 웹캠으로부터 입력되는 손동작 동영상을 처리하여 수화 패턴 신호를 인식하는 손동작 인식 알고리즘을 제안한다. 제안방법은 프레임간의 차 연산을 이용하여 움직이는 오브젝트를 추출하고, YCbCr로 변환하여 손 모양 영역을 추출하여 특정 크기의 정규화 영상으로 변화하며, 정규화 영상의 오브젝트의 무게중심점을 기준으로 원의 반지름을 결정하고 원을 탐색하여 손가락의 펴짐과 굽힘에 대한 패턴 비교를 통하여 손 모양을 인식한다.

• The Journal of the Convergence on Culture Technology
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• v.7 no.2
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• pp.411-417
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• 2021

The field that studies human-computer interaction is called HCI (Human-computer interaction). This field is an academic field that studies how humans and computers communicate with each other and recognize information. This study is a study on hand gesture recognition for human interaction. This study examines the problems of existing recognition methods and proposes an algorithm to improve the recognition rate. The hand region is extracted based on skin color information for the image containing the shape of the human hand, and the center of gravity profile is calculated using principal component analysis. I proposed a method to increase the recognition rate of hand gestures by comparing the obtained information with predefined shapes. We proposed a method to increase the recognition rate of hand gestures by comparing the obtained information with predefined shapes. The existing center of gravity profile has shown the result of incorrect hand gesture recognition for the deformation of the hand due to rotation, but in this study, the center of gravity profile is used and the point where the distance between the points of all contours and the center of gravity is the longest is the starting point. Thus, a robust algorithm was proposed by re-improving the center of gravity profile. No gloves or special markers attached to the sensor are used for hand gesture recognition, and a separate blue screen is not installed. For this result, find the feature vector at the nearest distance to solve the misrecognition, and obtain an appropriate threshold to distinguish between success and failure.

• The Journal of the Acoustical Society of Korea
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• v.38 no.4
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• pp.450-458
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• 2019

Passive cavitation imaging method is used to observe the ultrasonic waves generated when a group of bubbles collapses. A problem with passive cavitation imaging is a low resolution and large side lobe levels. Since ultrasound signals generated by passive cavitation take the form of a pulse, the amplitude distribution of signals received across the receive channels varies depending on the direction of incidence. Both the centroid and flatness were calculated to determine weights at imaging points in order to discriminate between the main and side lobe signals from the signal amplitude distribution of the received channel data and to reduce the side lobe levels. The centroid quantifies how the channel data are distributed across the receive channel, and the flatness measures the variance of the channel data. We applied the centroid weight and the flatness to the passive cavitation image constructed using the delay-and-sum focusing and minimum variance beamforming methods to improve the image quality. Using computer simulation and experiment, we show that the application of weighting in delay-and-sum and minimum variance beamforming reduces side lobe levels.