• Tribology and Lubricants
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• v.12 no.3
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• pp.72-78
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• 1996

This paper was undertaken to analyze the morphology of wear debris generated from lubricated moving machine surfaces by image processing. The lubricati, ng wear test was performed under different experimental conditions using the wear test device made in our laboratory and wear test specimen of the pin on disk type wear rubbed in paraffme series base oil, by varying applied load, sliding distance. The four parameters (50% volumetric diameter, aspect, roundness and reflectivity) to describe the morphology have been developed and outlined in the paper. A system using such techniques promises to obviate the need for subjective, human interpretation of particle morphology in machine condition monitoring, thus to overcome many of the difficulties with current methods and to facilitate wider use of wear particle analysis in machine condition monitoring.

• Journal of ILASS-Korea
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• v.1 no.4
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• pp.32-39
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• 1996

Fuel spray in the MPI gasoline injector and its atomization characteristics are investigated with both macroscopic and microscopic visualization systems. The Bosch injector is inserted into an air-assist spray adapter which is designed to be fabricated and assembled easily. particle motion analysis system is used to measure the SMD of injector, where the assistant air pressure is varied from 0.0 to 1.5bar with fuel pressure 2.8bar. Droplet size decreased with higher air pressure and fine fuel spray with below $60{\mu}m$ of SMD is acquired at the assistant air pressure over 0.5bar.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.04a
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• pp.807-812
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• 1999

Locating of reinforcing bars, in particular to know their accurate depths, is very important thing in radar inspection of concrete structures. By the way, a depth estimation of reinforcing bars in concrete structures by the radar is not easy because micorwave propagation velocity in test area is generally unknown. This problem can be solved by Generalized Hough transformation technique. Using this technique, the micorwave propagation velocity in test area can be detected from the radar image, which appear as hyperbolas conveying the velocity information in their shape. A developed speed-up technique for the computation of the Generalized Hough transformation is also investigated in this study. As a result, although it becomes difficult to locate reinforcing bars when multiple parallel bars lying too close together, there is a possibility of detecting accurate depths of reinforcing bars in test area by the proposed method.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.11a
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• pp.655-658
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• 2003

The crack of concrete structure plays an important role in the durability and safety of structure. Therefore, the features such as width, length, and direction of that must be measured periodically. The conventional method of measurement of cracks is manually sketched, however. it takes a fairly long time and lacks quantitative objectivity. This study proposes the algorithm to extract and analyze cracks automatically. The proposed algorithm is composed of two sub-algorithms. The extraction algorithm includes elimination of effect due to light, binarization. and noise reduction. The analysis algorithm includes thinning process, labeling, and calculation of crack width, length, and direction. The test to demonstrate the algorithm is fulfilled using the images of cracks on real concrete surface.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 1998.11a
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• pp.472-482
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• 1998

오늘날의 통신서비스들은 음성이나 데이터 서비스와 같은 전통적인 서비스 뿐만 아니라 비디오 서비스와 같은 대량의 데이터를 전송해야만 하는 멀티미디어 서비스를 포함한다. 이러한 요구를 수용하기 위해서 BISDN(Broadband Integated Digital Network)이 개발되었고 이의 기반 기술로 ATM이 채택되었다. 다양한 멀티미디어 응용들 중에서 VOD(Video On Demand), 화상회의 등은 데이터를 동시에 여러 목적지로 보내는 멀티캐스트 특성이 있다. 그러므로 멀티캐스트 능력은 멀티미디어 통신에서 매우 중요하다. 본 논문에서는 링망을 이용한 병렬 멀티캐스트 패킷스위치(Parallel Multicast Packet Switch with Ring Network: PMRN)에서의 분리된 HOL을 이용한 멀티캐스트 셀 스케줄링 기법을 제안한다. 이 기법은 입력버퍼의 앞단에 멀티캐스트 셀과 유니캐스트 셀을 위한 분리된 HOL을 두고 non-FIFO방식을 사용함으로서 입력버퍼 내에서 전송 가능한 멀티캐스트 셀과 유니캐스트 셀을 동시에 스케쥴링할 수 있도록 하여 입력버퍼 내에서의 지연을 감소시키고 링망과 일대일 연결 네트워크의 이용율을 높이며 스위치의 처리율을 높일 수 있다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 1998.10a
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• pp.211-221
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• 1998

A digital image processing technique which is able to get the velocity vector distribution of a surface of the spilled oil in the ocean without contacting the flow itself. This technique is based upon the PIV(Particle Imaging Velocimetry) technique and its system mainly consists of a high sensitive camera, a CCD camera, an image grabber, and a host computer in which an image processing algorithm is adopted for velocity vector acquisition. For the acquisition of the advective velocity vector of floating matters on the ocean, a new multi-frame tracking algorithm is proposed, and for the acquisition of the diffusion velocity vector distribution of the spilt oil onto the water surface, a high sensitive gray-level cross-correlation algorithm is proposed.

• Proceedings of the KIEE Conference
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• 2005.10b
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• pp.127-129
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• 2005

본 연구에서는 백라이트 유닛의 검사를 위한 머신비전 시스템을 구축한다. 시스템은 크게 하드웨어와 소프트웨어로 나눌 수 있고 하드웨어는 조명부, 영상획득부, 로봇 암 제어부로 분류된다. 조명부는 36W FPL램프로 구성되었고 조명부의 상판에 아크릴판을 거치대로 이용하여 백라이트 유닛을 거치한다. 로봇 암 제어부는 2축 로봇 암을 제어하여 로봇 암의 센서부착 지지대에 부착된 CCD 센서를 이동시킨다. 이와 동시에 영상획득부에서는 이미지를 획득하여 PC로 전송한다. 소프트웨어의 화상처리 검사 알고리즘은 일정 패턴이 있는 도광판에 대한 검사 알고리즘과 일정패턴이 없근 백라이트 유닛에 대한 검사 알고리즘으로 분리된다. 일정 패턴이 인쇄되어 있는 패널에 대한 검사 알고리즘은 모폴로지 연산을 이용하는 템플릿 체크방법과 블록 매칭 방법이 사용되었고 일정패턴이 없는 유닛에 대한 검사는 개선된 Otsu 방법을 이용하여 얼룩이나 흐릿한 결함에 대한 결함을 검출하였다. 실험결과 불균일한 결함과 밝기가 일정하지 않은 결함일지라고 90% 이상의 검출율로 뛰어난 성능을 입증하였다.

• 한국가시화정보학회:학술대회논문집
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• 2004.11a
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• pp.1-4
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• 2004

The PIV measurements are performed to get the quantitative flow visualization around a road vehicle. The model scaled with 1/48 is located in the middle test section of the closed-loop water tunnel and the measuring system consists of CCD camera, diode laser, synchronizer, and computer. The experimental data are obtained at two Reynolds numbers of 50,000 and 100,000 based on the model length. The quasi-three-dimensional isovorticity surfaces, based on two-dimensional velocity field data, are generated. There is little difference between the results in part of the recirculation region and the vorticity contour according to the Reynolds number. Also a little bit complicated three dimensional flows are predicted behind the road vehicle.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.04a
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• pp.563-567
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• 1996

This paper was undertaken to analyze the morphology of wear debris generating from moving lubricated machine surfaces by image processing. The lubricating wear test was carried out under different experimentaal conditions using the wear test device was made in our laboritory and wear testing specimen of the pin on disk type wear rubbed in paraffine series base oil, byvarying applied load, sliding distance. The four parameters(50% volumetric diameter, aspect, roundness and reflectivity) to describe the morphology have been developed and are outlined in the paper. A system using such techniques promises to obviate the need for subjective, human interpretation of particle morphology in machine condition monitoring, thus overcoming many of the difficulties with current methods and facilitating wider use of wear particle analysis in machine condition monitoring.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.04a
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• pp.281-285
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• 1996

In this paper, I made visual inspection system using Vision Board and it is consist of an illuminator (a fluorescent lamp), image input device(CCD(Charge)Coupled Device) camera), image processing system(Vision Board(FARAMVB-02), image output device(videomonitor, printer), a measuring instrument(TELMN1000). Length measurement by visual inspection system is used 100mm gauge block instead of calculating distance between camera and object, it measured horizontal and vertical length factor from 400mm to 650mm by increasing 50mm. In this place, measured horizontal and vertical length factor made use of length measurement of a injection. A measuring instrument used to compare a measured length of a injection visual inspection system with it. In conclusion, length measurement of a injection compared a measuring instrument withvisual inspecion system using length factor of 100mm guage block. Maximum error of length compared two devices a measuring instrument with visual inspection system is 0.55mm. And operation program is made up Borland C++ 3.1. By changing, it is applied to various uses.