• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.04a
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• pp.91-95
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• 1997

ESPI(Electronic Speckle Pattern Interferometry) is new optical measuring method to be able to measure the surface deformations of engineering components and materials in industrial areas. Conventional measuring method of surface deformation such as the strain gauge have many demerits because it is contact and point-to-point measuring one. But ESPI that is non-contact, whole field measuring method can overcome previous disadvantages. The speckle pattern to be formed with interference phenomena of scattering light from rough surfaces illuminated by laser light have phase information of surface In this study we used this interference phenomena and the phase shifting method to measure the in- plane deformation, together with the use of digital equipment to process the information contained in the speckle pattern and to display consequent inter ferograms. Finally we obtained good agreement between the experimenta results and those of FEM..

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.04a
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• pp.371-376
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• 1997

A 100*100.mu.m$^{2}$ aluminum micro mirror is designed and fabricated using a thick photoresist as a sacrificial layer andas a mold for nickel electroplating. The micro mirror is composed of aluminum mirror plate, two nickel support posts, two aluminum hinges, two address eletrodes, and two landing electrodes. The aluminum mirror plate,which is supported by two nickel support posts, is overhung about 10.mu.m from the silicon substrate. THe aluminum mirror plate is actuated like a seesaw by electrostatic force generated by electic potential difference applied between the mirror plate and the address electrode. This paper presents some methods to measure the optical and the dynamic characteristics of the fabricated micro mirror.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1998.03a
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• pp.82-87
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• 1998

Laser printer, faximile and copy machine are a few examples of OA(office automation) system. In such a system, the reflecting mirror has been employed for transmitting a target image to optical device. Therefore, to develope a good quality of optical system, the quality control of optical mirror was required. In recent years, considerable efforts have been directed toward the development of automated optical glass inspection system because the inspection is eye-fatigue and monotonous job for humans to perform. In this paper, we propose a inspection system applying algorithm of image processing for detecting defects of optical glass such as pinhole, scratch. From the experiments, the proposed inspection system shows reliable results.

• Journal of the Society of Naval Architects of Korea
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• v.50 no.2
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• pp.104-110
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• 2013

In this paper, the design procedure and results for 'Residual Life Prediction System Considering Corrosion and Coating' are explained, which is one module of 'Life-cycle Management System of Ship and Offshore Plant's' Operation. This 'Residual Life Prediction System' has two main functions; one is residual life prediction function based on probability processing using corrosion measurement data of ship's major structural members, and another is rust rate prediction function based on visual image processing of inspection photos. The analysis of system user requirements and functions are introduced, and the structure and environment of the developed system are explained.

• Journal of the Korean Society for Precision Engineering
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• v.11 no.5
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• pp.56-65
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• 1994

We have carried out a research on automatic measurement of gage blocks below 250mm and then improved the accuracy of the system, and reduced the measurement time using image processing technique and computer interface. The accuracy of the system is (230+10330 $L^{2}$)$^{2}$ nm (L:m) with confidence level of 95%. We participated APMP gage block intercomparision-1993/1994. The 1st round intercomparision showed that the measured values of all 5 gage blocks were within 21 nm from average.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1997.03a
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• pp.207-212
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• 1997

In estimating the formability of sheet metal, the stereo vision system contributes the accuracy of strain of sheet metal, the convenience in measuring the strain of sheet metal, and the handiness in preparing the forming limit diagram by calculating the 3D values and strain of sheet metal. The algorithm has been developed so that the 3D-coordinate values of sheet metal could be calculated by image processing which is composed of camera calibration, and the stereo matching of images in two viewpoints. By comparing with experiments, the possibility and the convenience of algorithm has been verified, which could calculate the 3D-coordinate values of sheet metal automatically by using the preprocessing of the original image of sheet metal, which had the noise before adjusting the camera calibration and the stereo matching algorithm.

• Proceedings of the KIEE Conference
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• 1995.11a
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• pp.225-227
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• 1995

An object detection algorithm using a modified IDM(Image Differential Method) is proposed for detecting an object in a level crossing area. The conventional object detection method using LASER light has the deadzone that it cannot detect small objects, while the object detection method using image data in a level crossing area can detect such small objects. But the image data in a level crossing area can be changeable easily because the data is outdoor and sensitive to such surrounding environments as the change of the sun beam, the shadow of cars, and so on. So we resolve these problems by adding the normalization and the process for shadow of the image data in a level crossing area to the basic IDM(Image Differential Method).

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2003.07a
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• pp.173-177
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• 2003

최근에 인터넷을 이용한 화상회의, 실시간 정보서비스, 협동작업, VOD 서비스등의 요구가 증가하면서 이런 서비스들을 효율적으로 처리할 수 있는 멀티캐스트 통신이 등장하였다. 멀티캐스트 통신에서는 데이터의 보호를 위하여 그룹 키를 사용하는데 수시로 회원의 가입과 탈퇴가 이루어지는 동적인 멀티캐스트 그룹에서 안전하고 효율적인 그룹 키의 전송이 중요한 문제로 등장하였다. 본 논문에서는 지금까지의 그룹 키 전송에 대한 연구들을 살펴보고 효율적이고 안전한 그룹 키 전송 방법을 제안함으로서 통신에 필요한 키들을 보관해야 하는 저장공간의 용량을 최소화하고 그룹키 전송시 일대일 통신방식인 유니캐스트방식을 이용하여 효율적이고 안전한 전송이 될 수 있도록 하였다.

• The Korean Fashion and Textile Research Journal
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• v.4 no.3
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• pp.284-288
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• 2002

In this research, a new quantitative fabric drape evaluation system has been developed using image processing technology. The purpose of this research is to get the more detailed information of fabric drapability quantitatively from digital images captured with a digital camera generally commercialized. The shape parameters of a 3-dimensional geometric drape model were defined as the number of nodes, frequency and amplitude. Also, various statistical information of drape shapes can be obtained using image processing technology and frequency analysis as well as traditional drape coefficients. Hardware system to capture drape images is simply composed of three parts including a digital USB (Universal Serial Bus) camera, a frame cover and a stand for camera to attach to traditional drape tester. The evaluation software coded with the MS Visual C++ is operated under the MS windows 9x above.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2000.11a
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• pp.91-98
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• 2000

The fuels of water-in-oil emulsion have a potential of reducing PM(Particulate Matter) and NOx emissions, and increassing combustion efficiency in the furnaces and the burners. For making the most of the beneficial of the secondary atomization due to the microexplosion, the water droplets distributed in the oil must have the optimal sizes. The purpose of this paper is to investigate the water droplet size distribution characteristics of the different types of the static mixers. For analysing the size distribution characteristics efficiently, image analysis system was constructed and an appropriate image processing algorithm was developed. Two kinds of static mixers: Kenics type and RF type, were tested. As a results, RF type static mixer shows a better characteristics in the mean drop sizes, particularly in the condition of high water content.