• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.1105-1109
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• 1995

A CCD-camera, which is structured with vision system, was used to realize automatic seam-tracking system and 3-D information which is needed to generate torch path, was obtained by using laser-slip beam. To extract laser strip and obtain welding-specific point, Adaptive Hough-transformation was used. Although the basic Hough transformation takes too much time to process image on line, it has a tendency to be robust to the noises as like spatter. For that reson, it was complemented with Adaptive Hough transformation to have an on-line processing ability for scanning a welding-specific point. the dead zone,where the sensing of weld line is impossible, is eliminated by rotating the camera with its rotating axis centered at welding torch. The camera angle is controlled so as to get the minimum image data for the sensing of weld line, hence the image processing time is reduced. The fuzzy controller is adapted to control the camera angle.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1255-1258
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• 2008

Roll to roll (R2R) system, known as 'web processing', is the process of producing these electronic devices on a roll of flexible plastic. With the need of improved performance and productivity in R2R industry, effective control and on-line supervision for web quality is essential. In this report, we present a system for on-line measurement of wrinkles, one of defects incurring due to compressive stresses developed in the web. This system is able to capture an image generated when a well defined line shape laser beam passes through a transparent web. The system calculates 3D shape information, including the height of the wrinkle on the web, and displays the images for the shape information of the web in real time. By using area scan camera and machine vision laser, this system takes more advantages of setting up as a simple and low cost system compared to the line scan camera systems that widely used in web manufacturing. Specific calibration method and analysis on the achievable accuracy will be discussed.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.53 no.5
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• pp.264-267
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• 2004

Recently the pulsed power systems have been widely used in many fields such as E/P(Electrostatic Precipitator), DeNOx/DeSOx power systems, ozone generators and power sources of the laser beam. In this paper, we studied various electrical characteristics for arc suppression of line-to-line electrodes in air and removal of the metaloxide using our pulsed power system. To obtain high efficiency of the pulsed power system, we repeatedly experimented and tested their characteristics. by adjusting electrode length of the load. As a result, when the value of the electrode length and pulse repetition rate were changed at the load, the value of the arc voltage changed at the electrode load. In conclusion, we controlled arc voltage of the load by ,changing electrode length and pulse repetition rate. Also. we stydied removal area of the metaloxide using area discharge according to pulse repetition rate.

• Journal of the Korean Society of Radiology
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• v.13 no.5
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• pp.699-704
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• 2019

It is important to minimize the exposure dose during an examination and obtain good quality images at the same time. This study compared the beam harding effect according to the baseline superior orbito meatal line(SOML), orbito meatal line(OML), inferior orbito metal line(OML) and measured the exposure dose of the lens, especially in brain CT examinations, which generally apply to head diease patients. The beam harding effect assessment of each image along the baseline was performed quantitatively using the Image J program, and the exposure dose of the lens was detected by OSLDs and compared. As a result, As a result, when the SOML was used as the reference line, the dose of the lens was decreased by 85.08% at 80 kV and by 79.7% at 80 kV, compared to when IOML was used as the baseline. If the gantry angle at brain CT was parallel scan to SOML, there were no significant differences in the exposure to the lens and between the OML and IOML. Therefore, this study has shown that it is efficient to have a parallel scan on SOML as a protocol during Brain CT examinations.

• Structural Engineering and Mechanics
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• v.9 no.4
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• pp.365-374
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• 2000

The structural behavior of connections between concrete-filled rectangular tubular column (CFRT column) and steel beam has been studied in this paper through sub-assemblage loading tests. It is found that the sub-assemblages exhibit ductile restoring force characteristics under seismic loading. A formula for the prediction of the yield strength of each member in the connection is proposed by using the yield line theory under the assumption of a simple stress transfer mechanism. It is shown that the proposed formula can produce a reasonable prediction while providing a basis for further investigation.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.696-699
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• 2004

A side scan sonar system uses the towfish installed sonars, It is an equipment that search images of the bottom surface of the sea in real time. It is a typical equipment that is related to a sea investigation such as a geological survey, seabed communication cable and power line cable placing repair investigation, fish breeding ground investigation, sea purification, relic and mineral investigation, and mine and submarine search. It used to fined objects and investigate on the seabed surface. But, recently, it is used to sea purification and geological survey that require information of the correct surface of the seabed. So, it needs various filtering technique and image processing techniques development to acquire high resolution image. therefore, this research develops a side scan sonar using multi-beam sensors that supply various information with the fast scan speed and correct high resolution that is not a simple underwater investigation equipment.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.1323-1326
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• 2004

A bogie frame of welded type have some problems. Some end beam has cracked. The cracks have profound influence on the safe freight service. The bogie consists of a frame, suspensions, brakes and wheel sets. Various analyses including a numerical simulation using a finite element method, a static load test, a fatigue test, and running test should be carried out to design the bogie. However cracks have been found at some end beams of the bogies mounted on the freight cars running with the high speed. The cracks of the end beam results in deterioration of the brake performance and the running safety. Numerical simulations and dynamic tests are carried out to figure out the causes of cracks in the existing bogie, and the vibrational characteristics of the improved bogie are compared with those of the conventional one. In this reports, the vibration characteristics were dealed with the most pressing matters for the solution of the end beam crack.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2000.11a
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• pp.219-225
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• 2000

The major movement block of the containers have range between apron and designation points on yard in container terminal. The yard tractor operated by human takes charge of its movement in conventional container terminal. In automated container terminal, AGV(Automated Guided Vehicle) has charge of the yard tractor's role and the navigation path is ordered from upper level control system. The automated container terminal facilities must have the docking system to guide landing line to have high speed travelling and precision positioning. The general method for docking system uses the vision system with CCD camera, infra red, and laser. This paper describes the detection of AGV's position and orientation using laser slit beam to develop docking system.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2006.06a
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• pp.317-318
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• 2006

The towfish oi a side scan sonar is an equipment that search images of the bottom surface of the sea in real time. It is a typical equipment that is related to a sea investigation such as a geological survey, seabed communication cable and power line cable placing repair investigation, fish breeding ground investigation, sea purification, relic and mineral investigation, and mine and submarine search. It used to find objects and Investigate on the seabed surface. But, recently, it is used to sea purification and geological survey that require information of the correct surface of the seabed. So, it needs various filtering technique and image processing techniques development to acquire high resolution image. Therefore, this research develops a side scan sonar using multi-beam sensors that supply various information with the fast scan speed and correct high resolution that is not a simple underwater investigation equipment.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.202-205
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• 2002

This paper describes the spot scanning with $^{11}$ C beams for the Heavy Ion Medical Accelerator in Chiba (HIMAC). The concave-shaped irradiation field was optimized and the dose distribution was measured by 128-ch ionization chamber. Because of the wide momentum spread inherent in $^{11}$ C beams, the dispersion caused from the beam line and the scanning magnets should be taken into account to calculate the dose distribution of $^{11}$ C beams and their irradiated field. The reconstructed dose distribution is in good agreement with the experimental results.