• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.1
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• pp.93-102
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• 2021

This paper describes the process of developing a concrete median barrier of SB4 grade with anti-glare function. The development section has a height and width of 1,270mm and 560mm, respectively. A wire mesh is placed in the center of the cross section to improve the protection performance. Collision analysis predicted that this section satisfies the strength and occupant protection performance, and that no damage to the barrier occurs. In the actual collision test, it was confirmed that this section satisfies the strength and occupant protection performance. However, damage was observed on two concrete barrier when the truck crashed. In order to improve the accuracy of the collision analysis of the concrete barrier in the future, it is considered that a study on the model development and continuous collision analysis method for domestic commercial vehicles should be carried out.

• Journal of the Korea institute for structural maintenance and inspection
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• v.26 no.6
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• pp.102-111
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• 2022

The aim of this study is to assess the seismic performance of octagonal hollow cross section reinforced concrete bridge pier, and to investigate the effect of longitudinal reinforcement ratios on the failure behavior. Four octagonal hollow section RC bridge columns of small scale model were tested under a quasi-static cyclically reversed horizontal load with constant axial load. The volumetric ratio of transverse spiral hoop of all specimens was maintained constant(0.206%), the ratios of longitudinal reinforcement were varied(2.36 ~ 4.71%). Failure behavior and seismic performance were investigated. Three specimens with the exception of lap spliced specimen showed flexure-shear failure at final stage. The test results with the exception of lap spliced specimen showed that the displacement ductility factor and accumulated energy dissipation decreased in inverse proportion to the ratio of longitudinal steel.

• Journal of the Korea institute for structural maintenance and inspection
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• v.26 no.3
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• pp.1-10
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• 2022

For the composite section of corrugated steel sheet and concrete, which is often used in soil structures, a conservative design method based on the ultimate strength state is still applied due to the difficulty of the analysis of compatibility condition. In this study, plastic analysis was performed on the flexural and axial strength of the composite section using two limit state design methods, LRFD and LSD. As a result of the analysis of the experimental results, the LRFD analysis value was interpreted as a conservative results for compressive strength, and it was analyzed that the effect of the concrete compressive strength was greater than the steel ratio of the steel plate. The flexural strength was analyzed to be in good agreement with the experimental results by the LSD analysis. From the parametric analysis on the design variables, the hogging moment, which is affected by the tensile strength of the steel plate, slightly decreased the increasing rate of the strength due to the influence of the bolts connection, but the sagging moment linearly increased according to the increment of steel reinforcement ratio.

• Journal of KIBIM
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• v.6 no.1
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• pp.1-8
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• 2016

This paper provides a method for generating flight path of Unmanned Aerial Vehicle (UAV) that is intended to be used in visual inspection of dome-type nuclear containment building. The method basically employs 3-D model to extract accurate location coordinates. Two basic route patterns that provide guide lines in defining moving locations were defined for each side wall and dome section of the containment. The route patterns support sequential capturing of images as well. In addition, several simple equations and an algorithm for calculation of the moving location on the route were developed on the basis of 3-D geometric characteristics of the containment building. A prototype computer program has been implemented to validate the proposed method, and a case study shows the method can visualize covering area in 3-D model as well.

• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2449-2451
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• 2001

The purpose of this paper is to develop image inspection system endows an automatic operating and measuring that the moment values are invariant with respect to variable object size and rotation. In this paper, using these moment feature vector with Hu's 7 invariant moment is also given. The characteristics of section which is applied in the mechanics used moment descriptor of invariant moment detection algorithm for image inspection system. Corresponding rates between 94% and 96% have archived for all object tested.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.6
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• pp.988-994
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• 2017

The risk of facilities in catenary is increasing because the railway section extension and high-speed train service. And visual check of workforce is not enough time to maintain the extensive railway facilities. Accordingly, The technical development trend of maintenance of railway facilities can be seen by automation and application of IT technology, especially the mechanization work and the information technology are spreading in the maintenance work of the train line solved by manpower. In this paper, we describe the method by obtaining the cantilever image using acquisition device and pole inspection system in high speed vehicle, to check the variation of the cantilever component using image processing.

• International Journal of Safety
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• v.10 no.1
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• pp.16-21
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• 2011

In this thesis, appearance inspection, compressive strength of concrete test, arrangement of bar inspection, survey, and bearing stress analysis were performed on a damaged coping of reinforced concrete pier to investigate the damage cause. According to the performed a series of inspections, it was found that the coping of pier was damaged during PSC (Pre-stressed Concrete) beam construction. In this thesis, the repair method for damaged pier was studied. The repair procedure used in this thesis was follows : chipping for damaged part, clean by high-pressure, installation of wire mesh, coating of surface hardening, construction of section restoration material, copula grinding, and prevent coating for far-infrared radiation.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.4
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• pp.1699-1703
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• 2012

Cervical cancer remains the most frequent cancer in women from the developing world. More than 88% of deaths occur in low-income countries, and it is predicted to climb to 91.5% by 2030. Although Pap-based screening programmes have shown to be effective in reducing the disease burden in high-resource countries, implementation and sustention of cytology-based programmes is quite challenging in low-resource settings. The present paper reviews evidence-based alternatives of screening methods, triaging algorithm, treatment of cervical precancerous lesions, and age-group at screening appropriate for low-income countries. Evidence shows that visual inspection methods using diluted acid acetic or Lugol's iodine, and HPV-DNA testing are more sensitive tests than the Pap-smear screening test. Visual inspection allows an immediate result and, when appropriate, may be immediately followed by cryotherapy, the so called "screen-and-treat" approach, achieved in a single visit, by trained nurses and midwives. Examples of cervical cancer prevention programmes in India and selected low-income countries are given.

• Journal of the Korea institute for structural maintenance and inspection
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• v.12 no.1
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• pp.151-157
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• 2008

It is difficult for existing beams to ensure the sufficient embedding depth due to constructional cause. Owing to these problems, currently FRP-Rod embedding repair method run parallel with a section increasing method in many case. In this study, anchor pin was adopted to solving the problems of the sliding of FRP-Rod and the unified behaviors of the repaired beam without increasing the section. In the experiments, split failure of covering concrete and slippage of the FRP-Rod were not occurred. it was confirmed that FRP-Rod shown the integrate behaviors with RC beam till the repaired beams destroyed.

• Journal of the Korea institute for structural maintenance and inspection
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• v.12 no.5
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• pp.116-124
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• 2008

In order to evaluate the behavior patterns of the ring beam by excavation at the vertical wall with circular section, the measured field datum were analyzed and evaluated in this study. Additionally, stress patterns of the ring beam with the change of excavation depth were estimated by using FE analysis. As the results, it was shown that the tendency of the measured values for the behavior patterns of the ring beam is similar to the analyzed values in FE analysis. From the tendency, it was confirmed that the behaviors of the ring beam due to change of excavation depth can predict by FE analysis using the suggested method in this study.