• Korean Journal of Computational Design and Engineering
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• v.22 no.2
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• pp.215-221
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• 2017

This paper describes a method of precise estimation for printing time and material consumption which are directly related to the 3D printing cost. Printing process and head motion of 3D printers using digital printing head, which is analyzed by its digitized steps, is rapidly simulated without slicing to calculate estimated printing results. Using this method, printing time and material usage of 3D printer were estimated quickly and precisely and compared to the real printing result. Applying compensation using the printing parameters, transferred from the 3D printer to the printing estimation system, even more accurate estimation is achieved. This method is used in the 3D Sprint software.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.2 no.3
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• pp.303-308
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• 1998

As the technology of industrial automation using robot system grows the rapid advance, productivity improvement and decrease in number of maintenance, management occur in many fields. Therefore, more various and intelligent robot motions are needed without human being help. Considering this situation, the need of robot with various, fast and safe acting sensors are demanded. In these sensings, the slippage sensing gives us specific information between ripper and object while grasps the object. In this paper, we proposed new slippage sensing algorithm for various and intelligent robot motion. So, optimal grasping force control and compensation of position error is possible for an adaptive task execution using adaptive control.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.8
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• pp.1708-1713
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• 2003

In this paper, we propose a new temporal error concealment method for video packet loss. Error concealment for each loss block is performed by temporal motion compensation and a spatial smoothing operation of boundary pixels between the compensated block and its surrounding blocks. In the simulation results, performance improvement for the proposed technique is on the average 2㏈ in comparison with conventional techniques.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.336-339
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• 2005

동영상에서의 움직임 검출에 대한 기술은 다양한 응용분야를 가지고 있다. 특히 고정된 카메라에서 움직임 검출과 움직이는 카메라에 대응하여 움직임 검출하고 추적하는 기법들은 현재까지 많은 연구들이 진행되고 있고, 또 응용 제품들의 출시되어지고 있다. 그렇지만 일반적이고 보다 완전한 제품의 개발은 아직 한계가 있다. 본 논문에서는 움직임 벡터를 이용하여 카메라가 패닝(Panning) 여부를 판단하여 패닝 시에는 움직임 검출을 하지 않는 기법을 제안한다. 이 기법은 카메라 패닝 시 즉, 카메라 팬/틸트 드라이버의 고장이나 바람등의 상황에는 움직임 검출을 하지 않음으로써 보다 효과적인 움직임 검출을 할 수 있다. 또한 두 개의 임계치를 적응적으로 조절할 수 있어 기존의 고정된 카메라에서 사용하는 움직임 검출 기법들보다 효율적이라고 할 수 있다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.4
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• pp.822-833
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• 1996

The video coding for very low bit rate has recently received considerable attention, but conventional block based transform coding schemes suffer from the blocking effect for the constraints of bit rates. In this paper, we present a video coding sysem suing multi-resolution motion estimation/compensation with variable size block(VMRME/C) and multi-resolution vector quantization(MRVQ) in wavelet transform domain for very low bit rate coding. It is shown that the presented scheme has better performance in the peak signal-to-nose ratio(RSNR) by 0.2-0.6 dB as well as subjective quality than that of conventional block based transform video coding techniques(especially, H. 263 which is DCT based video coding).

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.11B no.2
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• pp.28-33
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• 2001

The subject of this study is to improve the position performance of the linear motion for hybrid type Linear Pulse Motor (HLPM). Generally, there are two applicable methods to ensure precise position control ; a good processing method. This paper is suggested an electrical 125 microstep driving method so as to achieves the excellent control performance, besides the small mechanical manufacture of teeth pitch. The compensation method of digital PI control is apply to step response of stable position control, step error, vibration suppression and the approach to high stability, and the Ziegler-Nichols tuning method is applied to the proper design of control parameter. The proposed control method has been verified by simulation results of the suitable gain and phase margin of bode plot, and from experiment result of step response.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.54 no.7
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• pp.428-436
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• 2005

In this paper, we introduce an adaptive control method to improve the position accuracy and reduce nonlinear friction effects for the linear motion servo system with the nonlinear friction. The considered system plant included not only the variation of the mass of mover but also the friction change by the normal force. We also designed an adaptive controller with the mass estimator and the compensator by observing the variation of normal force. The effectiveness and system performances for the proposed control method in this paper show to improve than other control methods through numerical simulations.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2003.11a
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• pp.47-50
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• 2003

본 논문에서는 동영상을 효율적으로 부호화하기 위한 새로운 다중해상도 움직임 보상 방법과 잉여 양자화 방법을 제안한다. 본 논문에서 제안하는 동영상 부호화기는 다단계 이산웨이브렛 분해 움직임 예측 및 움직임 보상 블록 Tree 의 구성 및 블록 분할. 적응적 산술 부호화기로 구성된다 제안된 동영상 부호화기는 단순하면서도 낮은 연산량을 필요로 하며, 임베디드 특성과 SNR 계위 부호화 특성과 같은 좋은 기능을 제공한다. 또한 기존에 제안되었던 이산웨이브렛변환을 이용하는 동영상 부호화 방법과 비교하여 우수한 성능을 제공한다.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.6
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• pp.62-70
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• 2008

An adaptive fuzzy backstepping controller is proposed for the motion control for a single-link flexible-joint robot in the presence of parametric uncertainties. Fuzzy logic system is used to approximate the uncertainties of functions and a backstepping technique is employed to deal with the mismatched problem. A compensation controller is also employed to estimates the bound of approximation error so that the shattering effect of the control effort can be reduced. Thus the asymptotic stability of the closed loop control system can be obtained based on a Lyapunov synthesis approach. Numerical simulation results for a single-link flexible-joint robot are included to show the effectiveness of proposed controller.

• Journal of the Korean Society of Mechanical Technology
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• v.13 no.4
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• pp.31-36
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• 2011

Smart Door(SD) is a human friendly power-assisted door system for passenger car doors. It offers comfort and safety to passengers and drivers by supplying additional power. In this study, dynamic system model and the equation of motion derivation are derived. And we propose the disturbance observer based collision detection algorithm for safety when opening the door. A disturbance caused by collision has a fast response compared to a friction, uncertainties and so on. The main idea this study is to estimate a variation of disturbance for stably and effectively detecting a collision. In order to evaluate a performance of collision detection, an experiment set up is constructed. The experimental results validate the usefulness of the proposed collision detection algorithm.