• 제어로봇시스템학회:학술대회논문집
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• 1992.10b
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• pp.74-78
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• 1992

This paper describes an intelligent system to automatic evaluation of eddy current(EC) signal for Inspection of steam generator(SG) tubes in nuclear power plant. Some features of the intelligent system design in the proposed system are : (1) separation of representation scheme ,or event capturing knowledge in EC signal and for structural inspection knowledge in SG tubes inspection; (2) each representation scheme is implemented in different methods, one is syntactic pattern grammar and the other is rule based production. This intelligent system also includes an data base system and an user interface system to support integration of the hybrid knowledge processing methods. The intelligent system based on the proposed concept is useful in simplifying the knowledge elicitation process of the rule based production system, and in increasing the performance in real time signal inspection application.

• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.3
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• pp.70-79
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• 2020

The main objective of this research to develop an IoT based wireless contactless ultrasonic system (ICUS) and its application to concrete structure. The developed system consists of 16 mems, 2Mhz digitizer, amplifying circuit, FPGA, and wifi module, enabling to measure leaky surface waves from concrete specimens without physical coupling process and wires. Multi-channel analysis is performed to improve the accuracy of data analysis, and the velocity of leaky surface waves and acoustics are derived. Field inspection of railroad concrete sleepers is conducted to evaluate the performance of the system and to compare the results with conventional ultrasonic pulse velocity (UPV). As a result of the field inspection, UPV was limited to evaluate damages. This is because crack pattern of railroad sleepers is parallel to ultrasonic ray path and accessibility of the railroad at the field is disadvantageous to contact-based UPV. On the other hand, ICUS possibly detect the damages as reduction of dynamic modulus by up to 59% compared to non-damaged specimen.

• Proceedings of the Korean Information Science Society Conference
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• 2007.06c
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• pp.446-449
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• 2007

영상 학습은 컴퓨터를 이용한 자동 시각 검사에서 매우 중요하고 어려운 단계이다. 전자산업과 같이 신제품 개발 주기가 짧고 다양한 제품들을 검사하여야 하는 분야에서 어렵고 복잡한 학습 과정은 큰 문제가 되고 있다. 본 연구에서는 CAD 파일을 이용하여 PCB 자동 시각 시스템의 학습 과정을 손쉽게 할 수 있는 방안을 제시하였다.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1993.10a
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• pp.403-412
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• 1993

This paper presents the progress of the development of a nondestructive technique for the classification of normal, septicemic , and cadaver poultry carcasses by the Instrumentation and Sensing Laboratory at Beltsville, Maryland, U.S.A. The Sensing technique is based on the diffuse reflectance spectroscopy of poultry carcasses.

• Proceedings of the Korea Multimedia Society Conference
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• 2001.11a
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• pp.115-120
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• 2001

본 논문에서는 비닐 튜브의 결함검사에 이용하기 위한 이진화 임계치의 자동 결정방법과 패턴매칭에 이용되는 패턴 모델의 자동 친정방법에 대하여 기술한다. 256 Gray 영상을 받아 들여 이진화 임계치를 결성하기 위해서, 휘도치 분포 곡선에서 2개의 극대값을 찾고, 두 극대 위치의 중간위치를 이진화 임계치로 결정하는 방법을 이용하였다. 그리고 패턴 모델을 생성하기 위하여는 수직, 수평 방향의 누적함(Profile)을 이용하였다. 이 방법은 인쇄물 검사 시스템뿐 아니라 비슷한 휘도치 분포를 같는 반도체 자동 검사 시스템을 비롯한 일반적인 건사 시스템에 적용이 가능하다.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2007.06a
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• pp.15-18
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• 2007

As the line width of the pattern become thin more and more, the accuracy of ultra-precision stage should be increased. Various type stages have been developed and used in fabrication phase and inspection lab. Furthermore the line with become several tens of nanometer recently. We need ultra high precision stage. In this paper a new type stage is proposed in order to reduce the deformation of working table. The table is supported by several flexure hinges and actuated by a PZT. The local deformation is analyzed and the vibratory motion is also examined by FEM package.

• Proceedings of the Korean Fiber Society Conference
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• 2003.10b
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• pp.122-125
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• 2003

Ultrasonic wave has three classes of applications such as communication, inspection, imagination and processing. In processing, ultrasonic is used web bonding for nonwovens with applications including floppy disks, medical devices and many automotive Part. The important components of ultrasonic system are power supply, converter, booster, hem, anvil roller, pressure system and hold time controller. (omitted)

• Journal of the Korean Data and Information Science Society
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• v.16 no.2
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• pp.313-325
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• 2005

In Korea, there exists a large corpus of handwritten historical documents that serve as a valuable resource. Most of them are hand-written by the King's chroniclers and secretaries. Recently, the historical archives of Lee dynasty have been digitalized. Since it is extremely difficult to utilize conventional OCR system, most of the processes have been performed manually. In this paper, we propose OCR-based digitalization system using Mahalanobis distance-based rejection and interface for eye inspection about historical Hanja documents. Compared with our previous work, experimental results show that the proposed system can help enhancing the overall efficiency of the process.

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.951-954
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• 1998

This paper describes the implementation of the machine vision system and the method of classifying the objects. Its system described in this paper is consisted of robot, conveyer system, warehouse, and machine vision. This system first recognizes the object on conveyer, and then robot moves it to the warehouse. The position of the object on conveyer is always not constant, because it is not easy to extract the feature of its object and classify it into one of several categories. In this paper, to classify or inspect the pattern of the object, we propose the method of template matching using feature vector such as position invariant moment and mophological operation such as opening and closing. And we indentified an unregistered object using unsuperviser learning method and assigned it to the new pattern. We implemented its system and obtained satisfied results.

• Journal of Mechanical Science and Technology
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• v.19 no.3
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• pp.820-825
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• 2005

This paper proposes non-destructive ESPI technique to evaluate inside defects of semiconductor package quantitatively. Inspection system consists of ESPI system, thermal loading system and adiabatic chamber. The technique has high feasibility in non-destructive testing of semiconductor and gives solutions to the drawbacks in previous technique, time-consuming and the difficulty of quantitative evaluation. In result, most of defects are classified in delamination, from which it is inferred to the insufficiency of adhesive strength between layers and nonhomogeneous heat spread. The $90\%$ of tested samples have a delamination defect started at the around of the chip which may be related to heat spread design.