• 상하수도학회지
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• 제30권6호
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• pp.623-634
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• 2016

Sewer condition assessment involves the determination of defective points and status of aged sewers by a CCTV inspection according to the standard manual. Therefore, it is important to establish a reliable and effective standard manual for identifying the sewer defect. In this study, analytic reviews of the CCTV inspection manuals of the UK, New Zealand, Canada and South Korea were performed in order to compare the defect codes and the protocols of condition assessment. Through this, we also established the standardized method for defect code and revised the calculation method of assigning the condition grade. Analyses of the types and frequencies of sewer defects that obtained by CCTV inspection of 7000 case results, showed that the joint defect and lateral defect were the most frequent defects that occurred in Korea. Some defect codes are found to be modified because those did not occur at all. This study includes a proposed new sewer defect codes based on sewer characteristics.

• 한국건축시공학회지
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• 제20권6호
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• pp.567-576
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• 2020

본 연구는 공동주택의 하자소송의 사례분석을 통해 하자소송단계에서 추가적으로 하자로 인정되는 하자 항목을 제안한다. 이 하자 항목은 하자소송에서 추가적인 비용의 증가, 일정 지연, 재감정 혹은 추가소송을 방지할 수 있을 것이다. 하자소송에서는 입주자 및 건설사에서 사전에 인지하지 못한 새로운 하자항목이 발생되며, 이를 새로운 하자인정항목으로 정의하였다. 이를 위해 본 연구에서는 국내의 15개의 하자소송의 사례분석을 실시하였다. 이를 통해 77개의 소송하자를 1차 선별하고 전문가 자문을 통해 최종적으로 23개의 소송하자를 도출하였다. 이후 하자의 요인을 분석하여 최종적으로 23개의 소송항목을 총 10개의 요인항목으로 정립하였으며, 사례연구를 통해 효용성을 분석하였다. 본 연구의 결과는 하자의 발생을 저감하고 분쟁을 최소화하는 데 기여할 수 있을 것이다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2008년도 추계학술대회 논문집
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• pp.333-336
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• 2008

The groove rolling is a process that transforms the bloom or billet into a shape with circular section through a series of rolling. Inhibition of surface defect generation in groove rolling is a matter of great importance and therefore many research groups proposed a lot of models to find the location of surface defect initiation. In this study, we propose a model for maximum shear stress ratio over equivalent strain to catch the location of surface defect onset. This model is coupled with element removing method and applied to box groove rolling of POSCO No. 3 Rod Mill. Results show that proposed model in this study can find the location of surface defect initiation during groove rolling when finite element analysis results is compared with experiments. The proposed criterion has been applied successfully to design roll grooves which inhibits the generation of surface defect.

• 제어로봇시스템학회논문지
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• 제19권2호
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• pp.171-176
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• 2013

X-ray cross-sectional image-based inspection technique is one of the most useful methods to inspect the brazing joints of heat exchanger. Through X-ray cross-sectional image acquisition, image processing, and defect inspection, the defects of brazing joints can be detected. This paper presents a method to judge the type of detected defects automatically, and to display them three-dimensionally. The defect type is classified as unconnected defect, void, and so on, based on location, size, and shape information of defect. Three-dimensional display which is realized using OpenGL (Open Graphics Library) will be helpful to understand the overall situation including location, size, shape of the defects in a test object.

• 제어로봇시스템학회논문지
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• 제19권3호
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• pp.256-261
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• 2013

In the steel manufacturing area, researches for defect inspection receive a big attention for quality control. This paper proposes an algorithm to detect a scratch defect on steel billets. This algorithm takes ROIs (Regions of Interest), and extracts 11 features which represent properties of defect on a ROI. SVM (Support Vector Machine) is used to classify defect and normal ROIs. The algorithm classifies a frame image of a Billet as a defect image if there is one or more defect ROIs. In the experiments, the proposed algorithm had reliable classifying accuracy.

• 교육녹색환경연구
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• 제9권3호
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• pp.1-11
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• 2010

In the construction industry, IT based information system has been diversely applied to increase productivity. Although IT device such as PDA, RFID, Barcode, wireless network and web camera has been introduced to gather information in construction site, the effect of the IT device is limited, because of bringing about additional works of engineer. In this paper, we proposed a defect management system which is based on handwritten document digitalization framework for introducing applicability of new IT device, digital pen. By the proposed system, we can effectively gather and input defect information to defect management system by using digital pen and paper like conventional way. Applying the data gathering device, digital pen to defect management, it is able to increase productivity by improving work process, building up and utilizing defect information database of good quality.

• Journal of Biosystems Engineering
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• 제26권2호
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• pp.169-176
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• 2001

Defect of apple was depreciated the product value and causes storage disease seriously. To detect the defect of ‘Fuji’apple with machine vision system, the optical characteristics of defect should be investigated. In this research, absorbance spectra of defect were acquired by spectrophotometer in the range of visible and NIR region(400∼1,100nm) and L*a*b* color values were also acquired by colorimeter. NIR machine vision system was constructed with B&W camera, frame grabber, 16 tungsten-halogen lamps, variable focal length lens and NIR bandpass filter which was mounted to lens outward. Average gray values of defect at 15 NIR wavelength were acquired and the significant NIR wavelength was selected by comparing Mahalanobis distance between sound and defective apple. As the result of Mahalanobis distance analysis, the significant wavelength to discriminate the defectives in ‘Fuji’apple were found to be 720nm for scab and 970nm for bruise and cuts and 920nm was also effective regardless of defective types.

• Journal of Chest Surgery
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• 제28권9호
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• pp.865-868
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• 1995

A case of bronchogenic cyst associated with a partial pericardial defect is reported. Bronchogenic cysts are not so rare in incidence, but they are more rare when associated with a pericardial defect, the first case being reported by Rusby and Sellors in 1945. Recently, we experienced such a rare case of a bronchogenic cyst with a partial pericardial defect. The patient is a 39-year-old female and she was found to have a left anterior mediastinal mass during routine chest X-ray. During the operation, we detected partial pericardial defect after removal of the mediastinal mass. The pericardial defect was repaired with a Gore-Tex Membrane. The pathological examination of the mass showed a bronchogenic cyst. The patient had an uneventful hospital course.

• Journal of Chest Surgery
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• 제18권2호
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• pp.283-287
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• 1985

Seven patients had undergone repair of endocardial cushion defect from Jan. 1977 to Dec. 1984 at National Medical Center. Most patients had no associated anomalies except one who had PFO, and mortality case was absent. Five patients had partial ECD and two had complete ECD [Rastelli type A]. In P-ECD patients, the atrial septal defect was closed with patch in all cases and mitral cleft was approximated with 2-3 direct stitches. In two cases of C-ECD, atrial and ventricular septal defect was closed with single patch in one case and atrial septal defect was closed with patch but ventricular septal defect was closed with patch but ventricular septal defect was closed it direct suture in the other case. Atrioventricular cleft was approximated with 2-3 direct sutures. Postop. transient A-V block was noted in 2 cases but returned to regular sinus rhythm after 2 to 6 months.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.585-589
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• 2004

This paper deals with the algorithm development that inspects defects such as Lens Focus, Black Defect, Dim Defect, Color Defect, White Balance, and Line Defect caused by the process of Compact Camera Module (CCM). These days the demand of CCM goes on increasing in various types like PDA, a cellular phone and PC camera every year. However, owing to the defect inspection of CCM by the semiskilled work the average inspection time of CCM takes about 40 to 50 seconds. As time goes by the efficiency takes a sudden turn for the worse because workers must inspect with seeing a monitor directly. In this paper, to solve these problems, we developed the imaging processing algorithm to inspect the defects in captured image of assembled CCM. The performances of the developed inspection system and its algorithm are tested on many samples. Experimental results reveal that the proposed system can focus the lens of CCM within 5s and we can recognize various types of defect of CCM modules with good accuracy and high speed.