• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.1
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• pp.47-59
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• 2014

This paper deals with a vision-based trajectory tracking control system for a quadrotor-type UAV for entertainment purpose in indoor environment. In contrast to outdoor flights that emphasize the autonomy to complete special missions such as aerial photographs and reconnaissance, indoor flights for entertainment require trajectory following and hovering skills especially in precision and stability of performance. This paper proposes a trajectory tracking control system consisting of a motion generation module, a pose estimation module, and a trajectory tracking module. The motion generation module generates a sequence of motions that are specified by 3-D locations at each sampling time. In the pose estimation module, 3-D position and orientation information of a quadrotor is estimated by recognizing a circular ring pattern installed on the vehicle. The trajectory tracking module controls the 3-D position of a quadrotor in real time using the information from the motion generation module and pose estimation module. The proposed system is tested through several experiments in view of one-point, multi-points, and trajectory tracking control.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.45 no.3
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• pp.55-63
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• 2008

This paper presents a panorama background generation and object tracking technique using a Pan-Tilt-Zoom camera. The proposed method estimates local motion vectors rapidly using phase correlation matching at the prespecified multiple local regions, and it makes minimized estimation error by vector quantization. We obtain the required image patches, by estimating the overlapped region using local motion vectors, we can then project the images to cylinder and realign the images to make the panoramic image. The object tracking is performed by extracting object's motion and by separating foreground from input image using background subtraction. The proposed PTZ-based object tracking method can efficiently generated a stable panorama background, which covers up to 360 degree FOV The proposed algorithm is designed for real-time implementation and it can be applied to many commercial applications such as object shape detection and face recognition in various surveillance video systems.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.14 no.4
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• pp.239-246
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• 2021

In the field of computer graphics and HCI, there are many studies on systems that create characters and interact naturally. Such studies have focused on the user's response to the user's behavior, and the study of the character's behavior to elicit positive emotions from the user remains a difficult problem. In this paper, we develop a prototype of an interaction system to elicit positive emotions from users according to the movement of virtual characters using artificial intelligence technology. The proposed system is divided into face recognition and motion generation of a virtual character. A depth camera is used for face recognition, and the recognized data is transferred to motion generation. We use imitation learning as a learning model. In motion generation, random actions are performed according to the first user's facial expression data, and actions that the user can elicit positive emotions are learned through continuous imitation learning.

• Proceedings of the IEEK Conference
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• 2000.06d
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• pp.35-38
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• 2000

The method of Content-based Triangular Mesh Image representation in moving pictures makes better performance in prediction error ratio and visual efficiency than that of classical block matching. Specially if background and objects can be separated from image, the objects are designed by Irregular mesh. In this case this irregular mesh design has an advantage of increasing video coding efficiency. This paper presents the techniques of mesh generation, motion estimation using these mesh, uses image warping transform such as Affine transform for image reconstruction, and evaluates the content based mesh design through computer simulation.

• Proceedings of the Korea Multimedia Society Conference
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• 2001.11a
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• pp.890-895
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• 2001

In this paper, we address on the problem of automatic scheduling and motion generation of multiple mobile robots fur collecting material parts. We propose a model and so]union algorithm for the system. The formulated problem is divided into two kinds of problems; assignment problem and planning problem of robot motion. In this paper, several approaches to solution methods are presented and compared through computer simulation.

• Journal of Mechanical Science and Technology
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• v.17 no.7
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• pp.1036-1043
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• 2003

A computer simulation method for investigating the form generation mechanism in the centerless through-feed grinding process is described. The length of the contact line and the magnitude of the grinding force between the grinding wheel and workpieces, vary with the change in the axial location of the current workpiece during grinding. Thus, a new coordinate system and a grinding force curve of previous and/or following workpieces are introduced to treat the axial motion. Experiments and computer simulations were carried out using four types of cylindrical workpiece shapes. To validate this model, simulation results are compared with the experimental results.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.30B no.8
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• pp.41-53
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• 1993

The tasks which detect and track moving objects, by analyzing dynamic images taken at a constant time interval, are essential in various applications. This paper suggests how to utilize domain-specific knowledge and motional knowledge for detecting and tracking moving objects. That is, The trajectory information of a moving object is to be used for generating hypotheses on expected motion and expected position of moving objects, and the domain-specific knowledge is to be used for verifying the generated hypotheses.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2016.11a
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• pp.142-143
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• 2016

본 논문에서는 애니메이션, 드라마, 영화 등 영상으로 제작된 콘텐츠를 OpenGL를 사용하여 3D영상으로 재구성한다. 먼저 현재영상과 이전영상의 움직임의 차이로부터 운동 축적 데이터를 사용하여 모션 깊이맵을 생성한다. 그 깊이맵을 사용하여 OpenGL에서 사용하는 텍스쳐 맵핑으로 영상을 출력하고 3D 영상을 구현하기 위해 좌영상과 우영상을 생성하여 3D 입체영상을 만든다.

• Journal of Sensor Science and Technology
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• v.29 no.5
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• pp.312-322
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• 2020

As the use of mobile devices increase, there is public interest in the utilization of the human motion generated mechanical energy. The human motion generated mechanical energies vary depending on the body region, type of motion, etc., and an appropriate device has to be designed to utilize them effectively. In this work, a device based on the principles of triboelectric generation and inertia was assessed in order to utilize the multi-axial mechanical energies generated by human motions. To improve the output performance we confirm the changes in the output that vary with the structural design, the reasons for such changes, and variations in performance based on the parts of the human body. In addition, the level of electrical energy generated based on motion type was measured; a maximum voltage of 30 V and a current of 2 ㎂ were generated. Finally, the proposed device was utilized in LEDs used for lighting, thus demonstrating that multi-axial mechanical energies can be harvested effectively. Based on the results, we expect that the developed device can be utilized as a sensor to detect mechanical energies, to sense changes in motion, or as a generator for auxiliary power supply for mobile devices.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.113-118
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• 2005

Robots today have wider application fields than they ever have before. They need to work close to humans and fluid and compliable motions are expected of them. This requires redundant degrees of freedom for completing specific task. And conventional motion teaching method cannot be applied to redundant link structures. In this paper, the authors present a proficient, cost-effective and intuitive method for motion teaching. New software to apply this method to a humanoid is also presented. This new method utilizes current sensors to determine which joints to rotate. The experiment shown in this paper is a case of closed link where arms cannot move independently due to the restrictions in between the hands. After the input of several passing points of motion trajectory, the curve fitting is performed by the developed software. This software can insert new points, delete erroneous points and modify existing points. The developed motion teaching method is applied to the Kumdo robot, which is developed by the authors.