• Journal of Broadcast Engineering
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• v.23 no.2
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• pp.283-292
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• 2018

Devices capable of capturing and displaying high dynamic range (HDR) images with significantly increased brightness range compared to low dynamic range (LDR) images have been developed and various methods for efficiently converting the brightness range of an image have been developed. In this paper, we propose a reverse tone mapping method using a guided filter to efficiently convert LDR images into HDR images. After obtaining brightness enhancement function (BEF) using a guided filter, we can reconstruct HDR image from one LDR image. In addition, when the image is too bright or dark, the proposed method maximizes the image quality of the reconstructed HDR image by estimating and adjusting the exposure value before expanding the brightness range of images. Computer simulations show that the proposed method produces HDR images of superior quality compared with the conventional methods.

• The Journal of Korean Association of Computer Education
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• v.5 no.2
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• pp.91-100
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• 2002

The purpose of this study is to analyze the effect of Web-based self-directed learning and types of learning on the academic achievement and study attitudes of students. The subject of this study consists of 66 students of a high school. The group is divided into two subgroup. the self-directed learning group and teacher-guided learning group. each of which has 33 students. The results show that self-directed learning group improve academic achievement more than teacher-guided learning group. Especially. conceptual knowledge was more improved than principle-related knowledge. Self-directed learning proved to improve the subjects' study attitudes more than teacher-guided learning.

• Journal of Dental Rehabilitation and Applied Science
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• v.31 no.1
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• pp.67-74
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• 2015

Computer-guided surgery utilizing computed tomography is advantageous in placing implants precisely and conveniently. The purpose of the cases was to report a newly developed CT-based guide fabrication program and subtractive manufacturing using resin block. The guided surgery with the program and subtractive manufacturing allows not only precise translation of the treatment plan, but also offers additional significant benefits.

• Journal of the Korea Computer Graphics Society
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• v.5 no.1
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• pp.11-17
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• 1999

This paper proposes example guided inverse kinematics (EGIK) which extends and enhances existing inverse kinematics technique. In conventional inverse kinematics, redundancy in the model produces an infinite number of solutions. The motion could be jerky depending on the choice of solutions at each frame. EGIK exploits the redundancy for imitating an example motion (a premeasured motion data) so that a unique solution is chosen. To minimize the gap between the goal and current end-effector position and imitate the original motion at the same time, nonlinear optimization technique is employed. So, the resulting motion resembles the original one in an optimal sense. Experiments prove that the method is a robust and effective technique to animate high DOF articulated models from an example motion.

• Journal of the Korea Society of Computer and Information
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• v.8 no.1
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• pp.13-19
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• 2003

There are active researches on automated guided vehicles(AGV) generally used in flexible manufacturing system(FMS) or automated warehouse systems(AWS). Because existing AGV uses magnetic tapes, electric wire, RF or laser as guidelines, its installation and modification require a lot of money and time. The present study implemented AGV that detects paths marked with 50mm Yellow tape using a mono-color CCD camera. Because it uses color tape, it is easy and inexpensive to install and change lines. This study presented the structure of the developed AGV, the image Processing technique for detecting guidelines by ing the characteristics of color, and the result of operating AGV.

• Korean Journal of Optics and Photonics
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• v.22 no.3
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• pp.117-121
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• 2011

We propose a saturable absorber reflector based on guided-mode resonance. A carbon nanotube is used as a saturable absorber. By tuning the fill factor, modulation depth can be increased without a change of height of the CNT. We investigate the reflector properties such as modulation depth, bandwidth and peak reflectance as a function of the height of the CNT and the fill factor. The advantage of the proposed reflector is that it can reduce saturation energy by 50 times compared with CNT thin film of 100~200nm.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10b
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• pp.462-467
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• 1993

Even nowadays ships on the sea are important strategic base for aircraft and missiles. Thus we have been studying an unmanned attack system against ships recently. We experienced severa problems when this system was simulated on the computer. In this paper, problems and solutions of an Air-To-Sea Guided Bomb for this system are presented.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10a
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• pp.475-480
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• 1990

A design of aeroload simulator is proposed which is used for the dynamic test of guided missile servoactuation system. Since the simulator is linked to the servoactuation system, it is a two-input one-output system. The mathematical model of the aeroload simulator is derived and the root-locus method is applied to design compensator to improve the stability, response speed and accuracy of the system. Computer simulations are done to verify the goodness of the system design.

• Proceedings of the KIEE Conference
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• 1993.07a
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• pp.421-423
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• 1993

A real time simulation is an effective tool for use in design, performance evaluation, and testing of the vehicle dynamic system. An alternate approach is to use a computer system designed specifically to provide an integrated simulation environment in which all aspects of hardware-in-the-loop simulation task have been taken into account.

• Journal of the Korea Institute of Military Science and Technology
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• v.4 no.2
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• pp.138-146
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• 2001

The guided missile carries its own tracking radar to detect its target under noisy environments. The enemy warship uses the anti-missile electric-countermeasure(ECM) technique, such as chaff or decoy, so that the approaching guided missile could not destroy it. In this paper we propose the identification algorithm of a target signal when the enemy warship uses the chaff and decoy to deceive the guided missile. In the proposed scheme the mean square errors(MSE) between the received signals and the reference decoy signal, and between the received signals and the reference chaff signal are calculated. Then, the received signal which results in the maximum MSE is regarded as a warship signal. The performance of the proposed algorithm is verified through the computer simulation.