• International Journal of Highway Engineering
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• v.3 no.4 s.10
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• pp.137-146
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• 2001

Pavement distresses are one of the most important data for pavement management systems. Inspection machines and its related programs have been used for operating tools in PMS developed in advanced countries. In Korea imported machines and programs for the length price ale utilized to get information of pavement condition from the field This study is launched for developing the program which can detect cracks on asphalt pavement due to many drawbacks in current PMS operation such as improper maintenance work and long resting period when it was broken. The focus of this study is to define principles to analyze pavement surface with digital image processing techniques, to test property of pavement images and to suggest an algorithm that reduces noises at test. To test images, the camera attached on the Automatic Road Analyser(ARAN) was used. Through the FFT images, histogram and statistical values of pavement images, it was found that the images had many noises with high-frequency components against general images, and it was difficult to subdivide pavement images into background or crack. Through several testing with various filters for noise reduction a 3X3 median filter was suggested to reduce noises effectively.

• Journal of the Korean Society for Nondestructive Testing
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• v.30 no.4
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• pp.338-344
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• 2010

A double rotation C-scanning system and a software program Under-Sodium MultiVIEW have been developed for the under-sodium viewing of a reactor core and in-vessel structures of a sodium-cooled fast reactor KALIMER-600. Double rotation C-scanning system has been designed and manufactured by the reproduction of double rotation plug of a reactor head in KALIMER-600. Hardware system which consists of a double rotating scanner, ultrasonic waveguide sensors, a high power ultrasonic pulser-receiver, a scanner driving module and a multi channel A/D board have been constructed. The functions of scanner control, image mapping and signal processing of Under-Sodium MultiVIEW program have been implemented by using a LabVIEW graphical programming language. The performance of Under-Sodium MultiVIEW program was verified by a double rotation C-scanning test in water.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.32 no.3
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• pp.191-197
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• 2019

As the shipbuilding and offshore plant industries grow larger and more complex, their maintenance and inspection systems become more important. Recently, maintenance and inspection systems based on augmented reality have been attracting much attention for improving worker's understanding of work and efficiency, but it is often difficult to work with because accurate matching between the augmented model and reality information is not. To solve this problem, marker based AR technology is used to attach a specific image to the model. However, the markers get damaged due to the characteristic of the shipbuilding and offshore plant industry, and the camera needs to be able to detect the entire marker clearly, and thus requires sufficient space to exist between the operator. In order to overcome the limitations of the existing AR system, in this study, a markerless AR was adopted to accurately recognize the actual model of the pipe system that occupies the most processes in the shipbuilding and offshore plant industries. The matching methodology. Through this system, it is expected that the twist phenomenon of the augmented model according to the attitude of the real worker and the limited environment can be improved.

• Journal of Korean Tunnelling and Underground Space Association
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• v.23 no.6
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• pp.549-558
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• 2021

In order to keep infrastructures such as tunnels and underground facilities safe, cracks of concrete lining in tunnel should be detected by regular inspections. Since regular inspections are accomplished through manual efforts using maintenance lift vehicles, it brings about traffic jam, exposes works to dangerous circumstances, and deteriorates consistency of crack inspection data. This study aims to provide methodology to automatically extract cracks from tunnel concrete lining images generated by the existing tunnel image acquisition system. Specifically, we train a deep learning based semantic segmentation model with open dataset, and evaluate its performance with the dataset from the existing tunnel image acquisition system. In particular, we compare the model performance in case of using all of a public dataset, subset of the public dataset which are related to tunnel surfaces, and the tunnel-related subset with negative examples. As a result, the model trained using the tunnel-related subset with negative examples reached the best performance. In the future, we expect that this research can be used for planning efficient model training strategy for crack detection.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.9
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• pp.137-142
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• 2016

When injecting intravenously of CT inspection, the effusion of the contrast meium can induce the tissue damage with the blood vessel outside. We detect extravasation which is generated in the course where we inject the contrast medium into the blood vessel. And we use the bolus tracking system for the detection of that. By using MPR and VR images, moreover we detected the extravasation in order to prevent the tissue damage. In order to detect the effusion of the contrast medium, we used 16-MDCT and 64-MDCT. Three dimensional images about the outflow of the blood vessel can provide the treatment information which is important in the patient treatment. Moreover we applied the image processing technique in order to improve sharpness between contrast media and organization. And sharpness and contrast was improved.

• Journal of the Korean Society for Nondestructive Testing
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• v.28 no.1
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• pp.46-53
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• 2008

Ultrasonic C-scan technique is one of very popular techniques being used for detection of flaws in polymer matrix composite(PMC). However, the application of this technique is very limited for evaluation of defects in PMC fabricated by the automated fiber placement process. The purpose of this study is to develop a novel ultrasonic hybrid system based on nondestructive and non-contact ultrasonic techniques for evaluation of delamination in carbon/epoxy and carbon/PPS composite laminates. It was shown that the newly developed ultrasonic hybrid system based on dual air-coupled pitch-catch technique with ultrasonic scattering reflection concept could provide excellent image with higher resolution of delamination in PMC compared with the conventional pitch-catch method. It is expected that this ultrasonic hybrid technique can be applied for on-line inspection of flaws in PMC during the fabrication process.

• Korean Journal of Construction Engineering and Management
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• v.8 no.3
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• pp.66-75
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• 2007

Recently, After Service(AS) management in apartment housing projects has been appeared as one of the major factors for improving customer satisfaction, and increasing competitiveness and raising image of a company in construction industry. The primary objective of this paper is to propose a web-based AS management system which enables field engineers to effectively collect AS information required from customers and effectively manage the statuses and results of AS performed. It is anticipated that the effective use of the system proposed in this paper would be able to improve communication efficiency among the AS participants, and help field engineers systematically manage and accumulate data that might be utilized as a reference in future construction projects.

• The Journal of the Korea Contents Association
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• v.9 no.6
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• pp.178-186
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• 2009

The quality control is needed to ensure the accuracy of medical information and achieved by evaluating the performance of and maintaining the system and practicing various measurements and evaluations. The Korean Institute for Accreditation of Medical Image, therefore, have held educational program for quality control of special medical equipments. The major of programs participants, however, are radiology specialists with only small number of radiological technologists from some hospitals, furthermore, the follow-up education and the share of information between participants and non-participants are insufficient in general, thus, the knowledge level of radiological technologists, regardless of their participation, is relatively low. This study carried out the questionnaire research for the 500 radiological technologists registered in Korean Society of MRI Technology, on the basis of 2008, and performed analysis for five months from May to Oct., 2008. The questionnaires were delivered by post to each radiological technologists and the response rate was 36%(n=180). The results of this revealed that the 86.7% of respondents felt the necessity of inspection on quality management, while only the 27.8% completed the educational program for manager of special medical equipment. and only the half(53.9%) had the knowledge about inspection on quality management. The completion of educational program had no correlations with sex, age, size of occupying hospital, the number of radiological technologists in occupying site and MRI laboratory, career year of general radiologist and in MRI laboratory, and the presence of biomedical engineering department in occupying hospital. The 78.0% of participants at the educational program for quality management held by the Korean Institute for Accreditation of Medical Image had the knowledge about inspection on quality management(p<.05) whereas the 43.9% of the hospitals held such program and the 54.4% of radiological technologists from those hospitals had related knowledge, which indicated that such programs held by hospitals had not effects on the knowledge level of radiological technologists. This indicates also that the contents, methods, and other conditional factors of educational programs are important for the outcome of them.

• The Korean Journal of Nuclear Medicine Technology
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• v.20 no.1
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• pp.47-51
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• 2016

Purpose By ingestion of 18F-FDG of kidney of PET/CT during the inspection, if additional examination is required, depending on whether you want to water intake, we want to confirm a change in the rate of decrease of F-18 FDG of the kidney. Materials and Methods The 80 patients without kidney disease were performed PET/CT examination. Device was analyzed after setting the kidney to a three-dimensional region of interest. In patients require additional examination, and inspection after 30 minutes, a PET/CT torso examination after the water of the 500 cc ingested at a time. After the addition of both water intake group and no hydration group of kidney of SUV, it was compared with PET/CT torso scan. Results High and low of the kidney SUV did not show a significant difference in the rate of decrease. Reduction rates of background (BKG) of additional examination was 2.8% and reduction rates of SUV was 49.7% (Hydration) : -6.8% (No hydration), so did show a significant difference. In the image blind test, the average point score of hydration and no hydration was 34.25 : 17.25. Conclusion An undercurrent of 18F-FDG in the kidney at the time of torso examination, it was confirmed that the reduction rate after the addition of water intake is high. It is considered that can be expected to improve the quality of an image due to a decrease in elongation through the kidneys examination with additional fluid intake as needed intake.

• Journal of the Korea institute for structural maintenance and inspection
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• v.26 no.3
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• pp.11-20
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• 2022

The main purpose of this study is to investigate the applicability of the shear wave tomography technology as a non-destructive testing method to evaluate the debonding between the track concrete layer (TCL) and the hydraulically stabilized based course (HSB) of concrete slab tracks for the Korea high-speed railway system. A commercially available multi-channel shear wave measurement device (MIRA) is used to evaluate debonding defects in full-scaled mock-up test specimen that was designed and constructed according to the Rheda 200 system. A part of the mock-up specimen includes two artificial debonding defects with a length and a width of 400mm and thicknesses of 5mm and 10mm, respectively. The tomography images obtained by a MIRA on the surface of the concrete specimens are effective for visualizing the debonding defects in concrete. In this study, a simple image processing method is proposed to suppress the noisy signals reflected from the embedded items (reinforcing steel, precast sleeper, insert, etc.) in TCL, which significantly improves the readability of debonding defects in shear wave tomography images. Results show that debonding maps constructed in this study are effective for visualizing the spatial distribution and the depths of the debondiing defects in the railway concrete slab specimen.