• Proceedings of the KIEE Conference
• /
• 2002.07b
• /
• pp.1137-1139
• /
• 2002

In this paper, recurrent artificial neural network (RNN) based self tuning speed controller is proposed for the high performance drives of induction motor. RNN provides a nonlinear modeling of motor drive system and could give the information of the load variation, system noise and parameter variation of induction motor to the controller through the on-line estimated weights of corresponding RNN. Thus, proposed self tuning controller can change gains of the controller according to system conditions. The gain is composed with the weights of RNN. For the on-line estimation of the weights of RNN, extended kalman filter (EKF) algorithm is used. Self tuning controller that is adequate for the speed control of induction motor is designed. The availability of the proposed controller is verified through the MATLAB simulation with the comparison of conventional PI controller.

• Proceedings of the KSME Conference
• /
• 2007.05b
• /
• pp.2261-2266
• /
• 2007

In this study, the numerical analysis to estimate condensation heat and mass transfer of the condenser was carried out using the PMA (porous medium approach). In the PMA, the details of tube bundle in the condenser are replaced by the porous medium, and the flow resistance term is added in the momentum equation. In this regard, the PMA is quite helpful for the study of tube bundle in the large condenser. The pressure loss through tube bundle can be compensated by viscous and inertial momentum sink terms, which was validated numerically. Value of the pressure drop was compared to that of Butterworth correlation. Three dimensional analysis of condensation for McAllister condenser with the PMA was conducted using Fluent 6.2 and UDFs (use-defined functions). The result of condensation rate was analogous to previous results (experimental and numerical data).

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 1994.10a
• /
• pp.69-78
• /
• 1994

The broadband Power Splitters and Tap-Offs are needed to transmit a number of channels of signals with the high quality of signals. In this paper the design theories and analysis of the theoretical frequency characteristics of the Wilkinson's Power Splitters and Tap-Offs are reviewed. Then it has been showned that the theoretical frequency characteristics of the proposed compensated Wilkinson's Power Splitter and Tap-Off are improved much in comparison with the prototype wikinson's Power Splitter and conventional weakely-coupled Tap-Off. Furthermore the measured results of frequency characteristics for the fabricated circuits show agreement with the theoretical results and hence the validity of the proposed design and analysis methods has been confirmed.

• Journal of information and communication convergence engineering
• /
• v.8 no.2
• /
• pp.145-149
• /
• 2010

In this paper, we propose a kinematic approach to estimating the real-time moving object. A new scheme for a mobile robot to track and capture a moving object using images of a camera is proposed. The moving object is assumed to be a point-object and projected onto an image plane to form a geometrical constraint equation that provides position data of the object based on the kinematics of the active camera. Uncertainties in the position estimation caused by the point-object assumption are compensated using the Kalman filter. To generate the shortest time path to capture the moving object, the linear and angular velocities are estimated and utilized. The experimental results of tracking and capturing of the target object with the mobile robot are presented.

• The Transactions of the Korea Information Processing Society
• /
• v.5 no.4
• /
• pp.1044-1047
• /
• 1998

Non-destructive x-ray inspection system needs image intensifier to obtain the x-ray image. Captured image from image intensifier is distorted because the input plate of image intensifier has a spherical surface. In the research, in order to compensate this image distortion, we created the model of image intensifier and show mathematically that the image distortion was compensated. To show the performance of the proposed method, experiment was performed in real x-ray inspection system.

• Proceedings of the KIEE Conference
• /
• 2001.11a
• /
• pp.41-42
• /
• 2001

본 연구에서는 빠른 응답특성과 넓은 시야 각 특성을 갖는 Optically Compensated Bend Mode Liquid Crystal Displays(OCB LCDs)의 전기광학 특성을 계산하였다. 액정의 운동방정식을 시뮬레이션하여 얻은 분자배열 분포로부터 광학적 투과 특성을 계산하였으며, 누설광 차단과 수평 및 수직 방향의 넓은 시야각을 확보하기 위하여 보상필름으로써 Wide View Film을 적용하였다. 이러한 결과를 이축성 필름을 사용한 기존의 OCB LCDs와 비교함으로써 Wide View Film을 적용한 OCB LCDs의 시야의존 특성이 향상됨을 확인하였다.

• Transactions on Electrical and Electronic Materials
• /
• v.2 no.1
• /
• pp.16-21
• /
• 2001

A new technique to measure low level capacitance variations of a gyroscope is proposed. It is based on the improved CVC(capacitance to voltage converter) biased by a d.c. current source and the peak detector without any low pass filter. This setup of the measurement system makes it possible to provide higher speed of measurement and wide operation range. The d,c, drift of the conventional CVC and stray capacitances are automatically compensated. Key parameters that affect the performance of the measurement system are illustrated and computer simulation results are presented. The demonstrated measurement system for micromachined gyroscope applications shows a linearity of 0.99972 and a resolution of 0.67fF from 10 fF to 120 fF at 10 kHz.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.16 no.2
• /
• pp.207-213
• /
• 2013

An infrared image synthetic method is proposed for infrared system simulation. The synthesis image uses a background IR image captured from real scene and a target IR modeling image. The radiances related with maximum and minimum temperatures of the background and target images are calculated from the Planck's blackbody equation. Based on them, the background and target images are compensated and synthesized. The proposed method is simulated and the IR target images are generated by RadThermIR software.

• Journal of Electrical Engineering and Technology
• /
• v.10 no.1
• /
• pp.422-428
• /
• 2015

This paper proposes a high performance reversible watermarking (RW) scheme based on a novel compensation strategy. RW embeds data into a host image by modifying its pixel values slightly. It is found that certain modified pixels can be compensated to their original values during the proposed embedding procedure. The compensation effect in the RW scheme can improve the marked image quality significantly. By incorporating the pixel selection method, a higher quality image is obtained, which is verified by extensive experiments.

• Korean Journal of Child Studies
• /
• v.29 no.1
• /
• pp.207-225
• /
• 2008

This study used content analysis to explore how experience and coping style affect burnout in child-counselors. Data were self-reports collected by interviews of with 30 child counselors. The contents of the interviews showedthe cause of, psychological and physical responses to, and the ways the subjects coped with burnout. The summarized results are that (1) they experience burnoutwhen they feel incompetent, when counseling is ineffective, when they are under-compensated and when they are poorly supervised, (2) The psychological and physical responses to burnout are diminished self-esteem, depression, incompetence, chilling effect on other fields, and digestive problems. (3) Child-counselorscope with burnout mostly by centering on the problems and by searching for social support.