• Journal of Institute of Control, Robotics and Systems
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• v.18 no.5
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• pp.479-486
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• 2012

In this paper, a ranging system is proposed that is able to measure 360 degree omnidirectional distances to environment objects. The ranging system is based on the structured light imaging system with catadioptric omnidirectional mirror. In order to make the ranging system robust against environmental illumination, efficient structured light image processing algorithms are developed; sequential integration of difference images with modulated structured light and radial search based on Bresenham line drawing algorithm. A dedicated FPGA image processor is developed to speed up the overall image processing. Also the distance equation is derived in the omnidirectional imaging system with a hyperbolic mirror. It is expected that the omnidirectional ranging system is useful for mapping and localization of mobile robot. Experiments are carried out to verify the performance of the proposed ranging system.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2009.01a
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• pp.108-113
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• 2009

Significant attention has recently been drawn to digital home photo albums that use face detection technology. The tendency can be found in home photo albums that people prefer to allocate concerned objects in the center of the image rather than the boundary when they take a picture. To improve detection performance and speed that are important factors of face detection task, this paper proposes a face detection method that takes spatial context information into consideration. Experiments were performed to verify the usefulness of the proposed method and results indicate that the proposed face detection method can efficiently reduce the false positive rate as well as the runtime of face detection.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.421-424
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• 2002

The 3-D measurement using a sinusoidal grating pattern projection is very attractive because of its high measuring speed and high sensitivity. When a sinusoidal amplitude grating was projected on an object, the surface-height distribution of the object is translated into a phase distribution of the deformed grating image. The phase-acquisition algorithms are so sufficiently simple that high-resolution phase maps using a CCD camera can be generated in a short time. The PMP technique is discussed, and the analysis of the systematic errors, the calibration procedure designed to determined the optimal setting of the measurement parameters is illustrated. Results of measurements and calibrations on the measurement plane objects are described.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.271-274
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• 2002

The 3-D measurement using interference pattern projection is very attractive because of its high measuring speed and high sensitivity. When a sinusoidal amplitude grating was projected on an object, the surface-height distribution of the object is translated into a phase distribution of the deformed grating image. The patters was generated by a interferometer, and a PZT was used to shift the fringes on the target surface. The phase-acquisition algorithms are so sufficiently simple that high-resolution phase maps using a CCD camera can be generated in a short time. A working system requires a interferometer, a PZT, and a detector array interfaced to a microcomputer. Results of measurements on the diffused test objects are described.

• Proceedings of the KIEE Conference
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• 2001.11c
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• pp.280-283
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• 2001

Recently Many technologies of the Powerline communication are proposed these technologies used high carrier frequency for high speed and stability, but high carrier frequency is restricted by the low of electric wave. So we will propose electric monitoring system that used the commercial powerline communication modem, isn't restricted by the low. Our objects are, first, we compared the low in korea, EU(CENELEC), and USA(FCC). second, proposed a spec of the powerline communication modem. third, design that the electric monitoring system using commercial A/D converter control and manage the electric equipment.

• 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 KIEE Conference
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• 2000.07d
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• pp.3245-3247
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• 2000

We present an interactive virtual bronchoscopy method, which uses a tree structure of the objects and physically based camera control model. The proposed method archieves faster response by rendering only visible branches using the tree structure of the bronchus. A collision detection algorithm supplies a convenient and intuitive mechanism for examining the bronchus inner surface while a voiding collisions. We have improved the performances of navigation speed in virtual bronchoscopy.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.30 no.1
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• pp.12-19
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• 2022

The exhaust wake of an aircraft engine is discharged in a high temperature and high speed, which can damage objects such as an aircraft in the rear. The exhaust wake can lift small foreign substances lying on the ground or falling off, and the floating foreign substances can enter the intake duct of the aircraft moving from the rear and cause engine FOD (Foreign Object Damage). This study experimentally analyzed how the engine exhaust wake generated from military jet fighters affects the movement of foreign substances and evaluated the effects of foreign substances on the damaged area by measuring wake velocity. The simulation and field experimental results confirmed that the effect of exhaust wake increases as the rear position closer, and that foreign substances lifted by the wake can act as FOD to the adjacent rear aircraft.

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.1208-1210
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• 2002

This paper proposes a new position detection method for train speed control using the PDOA(Phase Difference of Arrival). This method aims to apply to AGT(Automated Guide way Transit) systems, operated with driverless. So it is absolutely required to range, calculate and decide a train position precisely. This system consists of VRS (Vehicle Radio Set) and WRS(Wayside Radio Set). The VRS transmits a wireless signal to the WRS, the controller calculate a straight line with the PDOA. Next step calculate an exact position using track DB. This paper includes the concept, configuration, analysis and results of this method.

• Journal of Institute of Control, Robotics and Systems
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• v.5 no.4
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• pp.437-445
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• 1999

Most autonomous mobile robots view only things in front of then, and as a result, they may collide with objects moving from the side or behind. To overcome this problem, an active omni-directional range sensor system has been built that can obtain an omni-directional depth map through the use of a laser conic plane and a conic mirror. In the navigation of the mobile robot, the proposed sensor system produces a laser conic plane by rotating the laser point source at high speed: this creates a two-dimensional depth map, in real time, once an image is captured. The results obtained from experiment show that the proposed sensor system is very efficient, and can be utilized for navigation of mobile robot in an unknown environment.