• Journal of Digital Convergence
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• v.14 no.11
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• pp.319-324
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• 2016

In the case of robot and Argument Reality applications using a camera in environments, a technology to estimate planes is a very important technology. A RGB-D camera can get a three-dimensional measurement data even in a flat which has no information of the texture of the plane;, however, there is an enormous amount of computation in order to process the point-cloud data of the image. Furthermore, it could not know the number of planes that are currently observed as an advance, also, there is an additional operation required to estimate a three dimensional plane. In this paper, we proposed the real-time method that decides the number of planes automatically and estimates the three dimensional plane by using the continuous data of an RGB-D camera. As experimental results, the proposed method showed an improvement of approximately 22 times faster speed compared to processing the entire data.

• Proceedings of the Korean Society of Computer Information Conference
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• 2022.01a
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• pp.365-368
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• 2022

본 논문에서는 가상 물체를 현실과 오차 없이 정확하게 증강 시켜야 하는 상황에서 특징 포인트를 이용하여 효율적으로 매칭하기 위한 실린더 기반의 각도 보간 기법을 제안한다. 증강현실에서 활용되는 대표적인 객체를 증강하는 방법은 특징 포인트들을 트래킹하여 찾아낸 후, RANSAC 알고리즘을 기반으로 포인트 셋에서 바닥, 벽과 같이 하나의 평면을 구성하고 그 위에 객체를 증강한다. 이 방법은 평면을 이용하기 때문에 계산량이 적지만, 증강 위치에 대한 오차가 존재하기 때문에 때때로 잘못된 위치에 객체가 배치되는 경우가 발생한다. 특히, 의료시설, 도로 공사에서 증강 현실을 사용했을 때에 증강된 가상물체의 위치, 크기 등이 현실에서 작은 오차라도 어긋날 경우 크게 사고가 발생할 수 있다. 본 논문에서는 평면 생성 없이 특징 포인트만을 이용하여 효율적으로 매칭 할 수 있는 실린더 기반의 각도 보간을 이용하여 정확하게 객체를 증강할 수 있는 결과를 보여준다.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.20 no.2
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• pp.127-136
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• 2007

In this paper, the equations of the scaled boundary finite element method are derived for non-homogeneous half plane and analyzed numerically In the scaled boundary finite element method, partial differential equations are weaken in the circumferential direction by approximation scheme such as the finite element method, and the radial direction of equations remain in analytical form. The scaled boundary equations of non-homogeneous half plane, its elastic modulus varies as power function, are newly derived by the virtual work theory. It is shown that the governing equation of this problem is the Euler-Cauchy equation, therefore, the logarithm mode used in the half plane problem is not valid in this problem. Two numerical examples are analysed for the verification and the feasibility.

• Proceedings of the Korean Information Science Society Conference
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• 2003.04c
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• pp.190-192
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• 2003

본 논문은 캘리브레이션 정보를 모르는 카메라로부터 얻은 시퀀스 영상에서 공간상에서 평면인 물체의영상 정보를 이용하여 카메라 내부 및 외부 파라미터를 추정하고, 이를 이용하여 가상의 3D 그래픽을 시퀀스 영상에 정합하는 방법을 제안한다. 제안된 방법은 기존의 방법에 비해 손쉽게 이미지에 가상의 3D 그래픽 오브젝트를 정합할 수 있으며, 눈에 보이는 정합오차를 최소화하며 DirectX와 같은 3D 그래픽 툴과 쉽게 연동이 되는 장정이 있다. 본 연구는 비디오와 같은 영상에 3D 영상을 합성하는 대화형 비디오 컨텐트 개발에 활용할 수 있을 것으로 기대된다.

• Journal of Korea Multimedia Society
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• v.12 no.2
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• pp.281-289
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• 2009

In this paper, a new interaction technique with the virtual single or dual acoustic reflection tablet is proposed to support the perception of depth cue and implement the effective spatial input systems of reducing the depth errors in general spatial sketching tasks. And several experiments show that the virtual wall with acoustic reflections can be thought of as a meaningful feedback for the plausible virtual conceptual design. By using the proposed idea, the degree of agreement to the target model is increased by 35% due to the single acoustic reflection tablet in the constant depth plane. In the slanted plane, the degree of agreement is increased by 8% due to the dual acoustic reflection compared to the single acoustic reflection and the degree of agreement is increased by 15% on the curved vase.

• Journal of Korea Multimedia Society
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• v.14 no.2
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• pp.171-181
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• 2011

A vision-based method for positioning and orienting of pallets is presented in this paper, which guides autonomous forklifts to engage pallets automatically. The method uses a single camera mounted on the fork carriage instead of two cameras for stereo vision that is conventionally used for positioning objects in 3D space. An image back-projection technique for determining the orient of a pallet without any fiducial marks is suggested in tins paper, which projects two feature lines on the front plane of the pallet backward onto a virtual plane that can be rotated around a given axis in 3D space. We show the fact that the rotation angle of the virtual plane on which the back-projected feature lines are parallel can be used to describe the orient of the pallet front plane. The position of the pallet is determined by using ratio of the distance between the back-projected feature lines and their real distance on the pallet front plane. Through a test on real pallet images, we found that the proposed method was applicable to real environment practically in real-time.

• Journal of Korean Society for Geospatial Information Science
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• v.19 no.4
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• pp.109-118
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• 2011

In this research estimated accuracies that were results in all the area of filtering of the plane equation that was used by whole data set, and regional of filtering that was driven by the plane equation for each vertual Grid. All of this estimates were based by all the area of filtering that deduced the plane equation by multiple linear regression analysis that was used by ground data set. Therefore, accuracy of all the area of filtering that used whole data set has been dropped about 2~3% when average of accuracy of all the area of filtering was based on ground data set while accuracy of Regional of filtering dropped 2~4% when based on virtual Grid. Moreover, as virtual Grid which was set 3~4 cm was difference about 2% of accuracy from standard data. Thus, it leads conclusion of set 3~4 times bigger size in virtual Grid filtering over LiDAR scan gap will be more appropriated. Hence, the result of this research allow us to conclude that there was difference in average accuracy has been noticed when we applied each different approaches, I strongly suggest that it need to research more about real topography for further filtering accuracy.

• Proceedings of the Korean Information Science Society Conference
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• 2000.04b
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• pp.646-648
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• 2000

본 논문은 악안면 기형 환자의 해부학적 구조를 기반으로 하여 임상적으로 수술 결과 영상을 생성하는 방법을 제시한다. 이 방법은 환자의 평면 방사선 사진으로부터 환자의 경조직과 연조직의 외곽선을 추출하고, 이를 바탕으로 연조직 이동량 예측 함수를 이용함으로써 환자의 해부학적 특성을 고려한 가상 수술을 수행한다. 예측함수는 경조직 특징점 8개의 이동량에 따른 연조직 특징점 10개의 변화량을 함수로 만든 것으로, 100명의 임상 결과를 바탕으로 도출한 것이다. 또한 환자의 평면 방사선 사진과 특징 부위의 외곽선, 그리고 환자의 외형사진을 쉽게 정합하는 인터페이스를 제공함으로써, 환자의 가상 수술 후 결과를 평면 방사선 사진 및 측면사진으로 표현하는 특징이 있다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.6
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• pp.549-559
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• 2015

In this paper, an efficient dynamic reactive motion planning method for an autonomous vehicle in a dynamic environment is proposed. The purpose of the proposed method is to improve the robustness of autonomous robot motion planning capabilities within dynamic, uncertain environments by integrating a virtual plane-based reactive motion planning technique with a sensor fusion-based obstacle detection approach. The dynamic reactive motion planning method assumes a local observer in the virtual plane, which allows the effective transformation of complex dynamic planning problems into simple stationary ones proving the speed and orientation information between the robot and obstacles. In addition, the sensor fusion-based obstacle detection technique allows the pose estimation of moving obstacles using a Kinect sensor and sonar sensors, thus improving the accuracy and robustness of the reactive motion planning approach. The performance of the proposed method was demonstrated through not only simulation studies but also field experiments using multiple moving obstacles in hostile dynamic environments.

• Journal of Korea Multimedia Society
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• v.15 no.4
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• pp.425-438
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• 2012

In this paper, We propose Augmented Reality (AR) System for the interaction between user's hand motion and virtual object motion based on computer vision. The previous AR system provides inconvenience to user because the users have to control the marker and the sensor like a tracker. We solved the problem through hand motion and provide the convenience to the user. Also the motion of virtual object using a physical phenomenon gives a reality. The proposed system obtains geometrical information by the marker and hand. The system environments like virtual space of moving virtual ball and bricks are made by using the geometrical information and user's hand motion is obtained from the hand's information with extracted feature point through the taping hand. And it registers a virtual plane stably by getting movement of the feature points. The movement of the virtual ball basically is parabolic motion with a parabolic equation. When the collision occurs either the planes or the bricks, we show movement of the virtual ball with ball position and normal vector of plane and the ball position is faulted. So we showed corrected ball position through experiment. and we proved that this system can replaced the marker system to compare to jitter of augmented virtual object and progress speed with it.