• 기계저널
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• 제16권4호
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• pp.19-25
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• 1976

가동검사의 검사결과는 이미 전에 실시한 가동중검사 결과와 비교 검토하게 된다. 비교 검토한 결과, 변화가 일어나지 않았으면 그것으로 좋으나, 만일 변화가 일어났다면 그 검사 결과를 평가 하여 어떠한 조치를 취할 것인가를 결정하게 된다. 이 경우 조치라 함은 어떤 변화가 일어난 부 분을 수리, 대체하거나, 또는 다음 검사 기간까지는 구조적 건전성에 관계 없다는 것이 확실히 규 명될 경우, 방치하는 것 등을 말한다. 그러나, 가동중검사에는 이미 언급하였듯이 그전의 검사 결 과와 비교 검토하게 되는데, 그때에 기초가 될 자료가 필요하다. 그래서 발전소의 일차냉각계통에 대한 수압시험이 완료되면 가동전검사(Pre-Service-Inspection)-사용점검사라고도 한다-를 수행 하여 가동중검사에 대한 기초자료로 삼는다. 가동점검사는 가동중검사 때에 상호 비교검토할 기 초 자료를 취하는 것이 목적이므로, 가동전 검사시의 검사방법 및 기술 등을 포함한 검사조건은, 앞으로 시행될 가동검사때의 예측되는 검사조건과 될 수 있는대로 동일한 상태가 되도록하여 그 검사결과 치를 비교함에 있어, 일어난 변화는 진정으로 원자료를 가동함에 의해 일어났다는 것을 보증할 수 있도록 하여야 한다. 이에 따라 특히 가동에 따라 접근하여 검사할 수 없는, 방사능의 오염될 부분의 가동전 검사에서도 가동중 검사시에 사용될것으로 예상되는 종류의 원격조정장치 룰 사용하여 비파괴검사를 사용하고 그 기록을 유지보관하여야 한다.

• 한국공작기계학회논문집
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• 제16권2호
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• pp.92-99
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• 2007

Welding fabrication invariantly involves three district sequential steps: preparation, actual process execution and post-weld inspection. One of the major problems in automating these steps and developing autonomous welding systems, is the lack of proper sensing strategies. Conventionally, machine vision is used in robotic arc welding only for the correction of pre-taught welding paths in single pass. In this paper, novel presented, developed vision processing techniques are detailed, and their application in welding fabrication is covered. The software for joint tracking system is finally proposed.

• 비파괴검사학회지
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• 제18권4호
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• pp.313-320
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• 1998

국내 원자력발전소 가압경수로 및 가압중수로에 대한 가동중검사 수행 동안 초음파 검사로 검출된 결함을 ASME 코드에서 기술한 center line beam 방법과 CSA 코드에서 기술한 6 dB drop 방법을 이용한 결함의 깊이 방향 크기 및 길이를 측정 비교 분석하므로서 두 방법을 정확히 이해하고 결함 평가에 대한 신뢰성 향상 및 원전의 건전성을 확보하고자 한다.

• 한국멀티미디어학회논문지
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• 제19권3호
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• pp.633-641
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• 2016

Automatic defect inspection system is composed of the step in the pre-processing, defect candidate detection, and classification. Polarizing films containing various defects should be minimized over-detection for classifying defect blobs. In this paper, we propose a defect detection algorithm using a skewness of histogram for minimizing over-detection. In order to detect up defects with similar to background pixel, we are used the characteristics of the local region. And the real defect pixels are distinguished from the noise using the probability density function. Experimental results demonstrated the minimized over-detection by utilizing the artificial images and real polarizing film images.

• 가정과삶의질연구
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• 제27권5호
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• pp.137-145
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• 2009

The purpose of this research to improve old age for marriage and the effect the development of the program is to validate. This program of eight to 60 years old elderly couple in 2008 was 8 in the 10 weeks. To verify the effectiveness of the program prior to the inspection of post-verification. According to the results of analysis, old age in conjugal relations, the area between the pre-post meaningful communication efficiency, the couple agreed, and the couple satisfaction, couple came to feel affection, and expression did not show a meaningful difference. The study on the future social welfare and family welfare-related practices and more effective old age, researchers developed a program to improve the couple relationship is important to emphasize is this.

• KIEE International Transactions on Electrophysics and Applications
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• 제2C권6호
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• pp.297-303
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• 2002

We have developed an on-line ultrasonic detector to monitor partial discharge in an operating transformer. The ultrasonic sensor has 150[KHz] resonance frequency and contains a pre-amplifier with 60[㏈] gain. The on-line ultrasonic detector has 50~300[KHz] frequency band-pass filter to remove electrical and mechanical noises from the transformer. This detector has an ultrasonic signal discrimination algorithm which discriminates ultrasonic signals due to partial discharge in a transformer. A moving average method of ultrasonic signal number was employed to effectively monitor the increasing trend of the partial discharge. This paper describes an experience of partial discharge detection in a 154[㎸] operating transformer using an ultrasonic detector. With regards to gas analysis in oil, C2H2 gas was produced with a warning level in this transformer We detected ultrasonic signals on the transformer steel wall, and estimated the position of partial discharge. With further inspection, we found carbonized marks due to partial discharge on the supporting bolt which fastens the windings.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 합동 추계학술대회 논문집 정보 및 제어부문
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• pp.342-348
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• 2002

This paper presents a computer image processing system, which measures the thickness of the ALC block and inspects the defect on a real-time basis. The Image processing system was established with a CCD camera, an image grabber, and a personal computer without using assembled measurement equipment. The image obtained by the system was analyzed by a devised algorithm, specially designed for the enhanced measurement accuracy. For the realization of proposed algorithm, the pre-processing method that can be applied to overcome uneven lighting environment, and threshold decision method, and subpixel method are developed. from the experimental results, we could find that the required measurement accuracy specification is sufficiently satisfied using our proposed method.

• Fibers and Polymers
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• 제6권2호
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• pp.156-161
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• 2005

The gray line-profile method is introduced to find fabric density. Some patterned fabrics like stripe design as well as solid fabrics of basic weave structures are used to verify the efficiency and accuracy of the method. The approach is compared with Fourier transform method. Although the gray line-profile method is concise, it shows good results in both solid and patterned fabrics. In addition, it does not require a pre-processing or filtering technique in space or frequency domain to enhance the image suitable for the analysis. However, the approach is slightly influenced by the filter size for finding the local minimums of profile graph.

• 대한원격탐사학회지
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• 제36권4호
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• pp.545-555
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• 2020

This paper focuses on automatic image registration between EO (Electro-Optical) and IR (InfraRed) satellite images with different spectral properties using block-based approach and simple preprocessing technique to enhance the performance of feature matching. If unpreprocessed EO and IR images from Kompsat-3A satellite were applied to local feature matching algorithms(Scale Invariant Feature Transform, Speed-Up Robust Feature, etc.), image registration algorithm generally failed because of few detected feature points or mismatched pairs despite of many detected feature points. In this paper, we proposed a new image registration method which improved the performance of feature matching with block-based registration process on 9-divided image and pre-processing technique based on adaptive histogram equalization. The proposed method showed better performance than without our proposed technique on visual inspection and I-RMSE. This study can be used for automatic image registration between various images acquired from different sensors.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1998년도 가을 학술발표대회 논문집(III)
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• pp.649-655
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• 1998

In this study, the personal-computer program was developed to predict prestressing losses containment structures of Nuclear Power Plants by concrete creep and shrinkage. This program is constituted of three parts, which are pre-processor, calculation module and post-processor. Input data for his program are : material properties of concrete, rebar, liner and duct, test results of concrete creep and shrinkage, relative humidity, dimension of containment structures, and the number of prestressing tendon related on containment structures. To obtain better results, this program was made to reflect the prestressing losses due to influence that occurred after prestressing each tendon, thus it can predict prestressing losses and allowable prestressing forces of each tendon. As a case study, this program was applied to containment structures of Youngwang 3 & 4 NPP's and analytical result was compared with test results in In-service Inspection of containment structures. From this comparison, it was proved that this program could well predict prestressing losses by concrete creep and shrinkage.