• Proceedings of the Korea Society of Information Technology Applications Conference
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• 2005.11a
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• pp.173-176
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• 2005

This paper proposes a fuzzy correction algorithm that can correct the distorted medical image caused by the scanning nonlinear velocity of the Digital X-ray Scanner System (DX-Scanner) using the Multichannel Ionization Chamber (MIC). In the DX-Scanner, the scanned medical image is distorted for reasons of unsuitable integration time at the nonlinear acceleration period of the AC servo motor during the inspection of patients. The proposed algorithm finds the nonlinear motor velocity modeling through fuzzy system by clustering and reconstructs the normal medical image lines by calculating the suitable moving distance with the velocity of the motor using the modeling, acceleration time and integration time. In addition, several image processing is included in the algorithm. This algorithm analyzes exact pixel lines by comparing the distance of the acceleration period with the distance of the uniform velocity period in every integration time and is able to compensate for the velocity of the acceleration period. By applying the proposed algorithm to the test pattern for checking the image resolution, the effectiveness of this algorithm is verified. The corrected image obtained from distorted image is similar to the normal and better image for a doctor's diagnosis.

• KSTLE International Journal
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• v.2 no.2
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• pp.146-149
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• 2001

Recently, laser printers have been developed to have high-speed laser scanner with hydrodynamic bearings. Among the bearings, herringbone grooved bearing (HGB) produces hydrodynamic pressure by high-speed rotating and so make the surfaces between the shaft and sleeve separated. Accordingly, the bearings with non-contact rotation are suitable to high-speed rotating and have long bearing life and reliability. HGB is a kind of journal bearing and uses oil for a lubricant. HGB has excellent stiffness and load carrying capacity. Also, HGB is leakage-free due to groove pumping action. Consequently, HGB is valuable to be applied to high-performance devices such as hard disk drive, copier, and so on.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.1
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• pp.65-72
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• 2016

This paper presents the analysis of the analysis of thrust characteristics of linear induction motors(LIMs) according to secondary reaction plate. LIMs are well known as high speed transport systems, which can obtain thrust directly without gears and links, or auxiliary mechanisms. A simple structure, easy maintenance, and less environmental pollution are advantages of LIMs. In transport systems using LIMs, the secondary reaction plate is an important design factor, because it has considerable impact on the cost of the railway as well as the performance of the LIMs. This paper deals analyzed the characteristics of linear induction motor used for moving the vehicle of container scanner. Thrust, efficiency and load characteristic were interpreted with FEM regarding two models whose material of secondary reaction plate was copper and aluminum. It suggested the interpretation of thrust, efficiency and power factor characteristic along slip and compared the operation ability of linear induction motor through characteristics analysis along the load.

• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.4
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• pp.138-144
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• 2014

Now, Autonomous unmanned vehicle has become an issue in next generation technology. 2D Laser scanner as the distance measurement sensor is used. 2D Laser scanner detects the distance of 80m, measured angle is -5 to 185 degree. Laser scanner detects only the plane, but using motor swings. As a result, traffic signs detect and analyze patterns. Traffic signs when driving at low speed, shape of the detected pattern is very similar. By shaking the laser scanner, traffic signs and other obstacles became clear distinction.

• Proceedings of the Korea Institute of Convergence Signal Processing
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• 2000.12a
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• pp.149-152
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• 2000

A scanner is an output device that scans documents, photographs, films etc, and convert them to digital data. Especially, a film scanner is used for scanning negative/positive films. In this paper, we design step motor control part, image sensor part, and Aか converter part which are components of the scanner and use DSP for fast signal processing. We also design the interface circuits using EPLD between these peripherals and DSP. The PC interface circuits between scanner and PC are designed by using parallel port to control and transfer the scanned data from scanner to PC. For 35mm film, we design hardwares which obtain high resolution more than 9 million pixels (horizontal resolution is 3835 and vertical resolution is 2592).

• International Journal of Advanced Culture Technology
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• v.8 no.3
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• pp.260-268
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• 2020

Currently, it is usually a 3D scanner processing method as a laser method. However, the laser method has a disadvantage of slow scanning speed and poor precision. Although optical scanners are used as a method to compensate for these shortcomings, optical scanners are closely related to the distance and precision of the object, and have the disadvantage of being expensive. In this paper, 3D scanner using variable focus lens-based structured light module with improved measurement precision was designed to be high performance, low price, and usable in industrial fields. To this end, designed a telecentric optical system based on a variable focus lens and connected to the telecentric mechanism of the step motor and lens to adjust the focus of the variable lens. Designed a connection structure with optimized scalability of hardware circuits that configures a stepper motor to form a system with a built-in processor. In addition, by applying an algorithm that can simultaneously acquire high-resolution texture image and depth information and apply image synthesis technology and GPU-based high-speed structured light processing technology, it is also stable for changes to external light. We will designed and implemented for further improving high measurement precision.

• Proceedings of the KIPE Conference
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• 2007.11a
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• pp.157-159
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• 2007

본 연구는 인코더를 사용한 Flatbed scanner DC 서보 모터시스템의 저속 제어기 설계 기법을 제안한다. 실제 구동되는 저속에서 DC 모터 시스템을 MSR 알고리즘으로 모델링하여 파라미터의 변동과 부하 외란을 추정하고, 속도 제어주기마다 위치 추종명령을 계산하여 실제 위치에 대한 에러를 보상하도록 설계함으로써 저속에서의 속도 추종능력을 향상시킨다.

• Journal of the Korean Society for Nondestructive Testing
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• v.23 no.1
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• pp.30-37
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• 2003

In order to replace the manual ultrasonic testing(UT) with an automated UT(AUT), a scanner which enables us to control the positions of a transducer is essential. Encoders have been commonly used to obtain the position information from the conventional scanners controlled by motor. Encoders have various advantages in many aspects. However, if the slip of motor wheel occurs during scanning, various errors are involved in the position accuracy. Thus, the position information of encoders becomes meaningless in case of slip. The reliability of AUT results nay become serious problem. Hence, slip must be avoided, but it can not be completely avoided at present time. In this paper, a new idea that surface wave is used to solve this problem and replace encoders has been proposed. It is shown that this idea can be employed in AUT scanner without encoders. That is, one transducer transmitting surface wave is fixed and the other transducer attached to the scanner receives UT signal. Then, computer calculates the present position of scanner based on the information given by surface wave. Thus, the movement of a scanner can be controlled by the amount of input based on the information obtained.

• Proceedings of the KIEE Conference
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• 2005.10c
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• pp.118-121
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• 2005

The claw-pole PM(Permanent Magnet) stepping motor has the advantage of the positioning machine because of a relatively little step angle, facility of control, and detent torque characteristics. Although the research about this motor has been progressed, it was difficult to analyze because of three-dimensional magnetic circuit. This paper proposed a design method of the claw-pole PM stepping motor using 3D-FEA. We established design variables that have an important effect upon the characteristics of the motor, and then peformed analysis of the static and the dynamic characteristics. We also manufactured the test products and practiced the performance tests for verification of the analysis results.

• Laser Solutions
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• v.8 no.3
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• pp.27-30
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• 2005

Nowadays, most automotives companies are making use of laser welding in car body assembly shop. But even though laser welding is better than resistance spot welding in many points, its application has been limited to special technology for manufacturing. The paper introduces in the field of remote welding system (RWS) to improve the process efficiency of laser welding. Positioning time of RWS between welding stitches is dramatically reduced to zero. It is a kind of solutions to generalize laser welding in mass production. This RWS consists of fiber laser, industrial robot and 3-axis scanner.