• Title/Summary/Keyword: Non-destructive Diagnosis

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Case Study on the Impact-Echo Method for Tunnel Safety Diagnosis (터널 안전진단을 위한 충격반향법 사례 연구)

  • Shin, Sung-Ryul;Jo, Cheol-Hyun
    • Tunnel and Underground Space
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    • v.19 no.1
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    • pp.19-30
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    • 2009
  • For the purpose of determining the thickness of concrete lining and detect of the cavity where may be located behind tunnel lining, IE (Impact-Echo) method it effectively useful in the tunnel safety diagnosis and the quality control during the construction. As a part of case study, we applied IE method to various tunnel structure types such as road tunnel and subway tunnel constructed by NATM (New Austrian Tunnelling Method) and ASSM (American Steel Support Method). As tunnel specifications estimated from this method were compared with coring data, design drawing and other survey results, it was very good agreement with each other. In conclusion, we verified that IE method shows an accurate and reliable result. The conventional interpretation of IE method in frequency domain gives only vertical information at a certain point. However, the interpretation using time-frequency analysis and depth section imaging technique from two dimensional profiling surveys can show more reliable information about structure inside.

Conservation Status Diagnosis of Mural Painting in Geungnakjeon Hall of Daewonsa Temple, Boseong: Avalokitesvara Bodhisattva Mural and Buddhist Monk Bodhidharma Mural

  • Lee, Hwa Soo;Eom, Tae Ho;Jee, Bong Goo;Yi, Sun Jo;Yu, Yeong Gyeong;Han, Kyeong Soon
    • Journal of Conservation Science
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    • v.38 no.4
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    • pp.314-326
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    • 2022
  • Investigation of conservation status, optical survey, infrared thermography, and ultrasonic examination were performed on Avalokitesvara Bodhisattva mural and Buddhist Monk Bodhidharma mural to determine the conservation status and physical properties. As a result of investigation of conservation status, the types of damage are largely divided into the wall and finishing layer damage, painting layer degradation, damage due to restoration materials, stains and contamination, and biological damage. As a result of the optical survey, drawing, stains, and repainted site were confirmed. Result of the infrared thermography, the delamination of the finishing layer was confirmed, and some locations and shapes of the wooden lath inside the wall were identified. The result of the 3D scanning, the deviation, and the separation of the wall was confirmed. As a result of ultrasonic examination, it was confirmed that the physical properties of the mural were identified and the ultrasonic speed was relatively low due to physical damage such as delamination and exfoliation of the finishing layer and cracking. Ultrasonic speed values were also high in some wall cracks or delamination, and it was confirmed by the infrared thermography results that the wooden lath inside the wall was located in those parts. It was possible to understand that the wooden lath inside the walls affects the ultrasonic speed during the ultrasonic examination. Therefore, management through periodic inspection of the relevant elements is necessary, and a countermeasure for damage that may occur in the future should be prepared along with intensive monitoring of the major damage identified in this diagnosis result.

Current status and prospects of plant diagnosis and phenomics research by using ICT remote sensing system (ICT 원격제어 system 이용 식물진단, Phenomics 연구현황 및 전망)

  • Jung, Yu Jin;Nou, Ill Sup;Kim, Yong Kwon;Kim, Hoy Taek;Kang, Kwon Kyoo
    • Journal of Plant Biotechnology
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    • v.43 no.1
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    • pp.21-29
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    • 2016
  • Remote Sensing (RS) is a technique to obtain necessary information in a non-contact and non-destructive method by using various sensors on the surface, water or atmospheric phenomena. These techniques combine elements such as sensors, and platform and information communication technology (ICT) for mounting the sensor. ICT has contributed significantly to the success of smart agriculture through quantification and measurement of environmental factors and information such as weather, crop and soil management to distribution and consumption stage, as well as the production stage by the cloud computer. Remote sensing techniques, including non-destructive non-contact bioimaging (remote imaging) is required to measure the plant function. In addition, bioimaging study in plant science is performed at the gene, cellular and individual plant level. Recently, bioimaging technology is considered the latest phenomics that identifies the relationship between the genotype and environment for distinguishing phenotypes. In this review, trends in remote sensing in plants, plants diagnostics and response to environment and status of plants phonemics research were presented.

Concrete Crack Detection Inside Finishing Materials Using Lock-in Thermography (위상 잠금 열화상 기법을 이용한 콘크리트 마감재 내부 균열 검출)

  • Myung-Hun Lee;Ukyong Woo;Hajin Choi;Jong-Chan Kim
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.27 no.6
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    • pp.30-38
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    • 2023
  • As the number of old buildings subject to safety inspection increases, the burden on designated institutions and management entities that are responsible for safety management is increasing. Accordingly, when selecting buildings subject to safety inspection, appropriate safety inspection standards and appropriate technology are essential. The current safety inspection standards for old buildings give low scores when it is difficult to confirm damage such as cracks in structural members due to finishing materials. This causes the evaluation results to be underestimated regardless of the actual safety status of the structure, resulting in an increase in the number of aging buildings subject to safety inspection. Accordingly, this study proposed a thermal imaging technique, a non-destructive and non-contact inspection, to detect cracks inside finishing materials. A concrete specimen was produced to observe cracks inside the finishing material using a thermal imaging camera, and thermal image data was measured by exciting a heat source on the concrete surface and cracked area. As a result of the measurement, it was confirmed that it was possible to observe cracks inside the finishing material with a width of 0.3mm, 0.5mm, and 0.7mm, but it was difficult to determine the cracks due to uneven temperature distribution due to surface peeling and peeling of the wallpaper. Accordingly, as a result of performing data analysis by deriving the amplitude and phase difference of the thermal image data, clear crack measurement was possible for 0.5mm and 0.7mm cracks. Based on this study, we hope to increase the efficiency of field application and analysis through the development of technology using big data-based deep learning in the diagnosis of internal crack damage in finishing materials.

Eosinophilic granuloma in the anterior mandible mimicking radicular cyst

  • Lee, Byung-Do;Lee, Wan;Lee, Jun;Son, Hyun-Jin
    • Imaging Science in Dentistry
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    • v.43 no.2
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    • pp.117-122
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    • 2013
  • Eosinophilic granuloma is a common expression of Langerhans cell histiocytosis and corresponds with typical bone lesions. The radiographic appearance of eosinophilic granuloma in the jaw is variable and not specific. It may resemble periodontitis, radicular cyst, or malignancies. The purpose of this report is to describe the characteristic radiographic features of eosinophilic granuloma of a 39-year-old male. The lesion in the anterior mandible was first diagnosed as radicular cyst because the radiographic findings were ovoid radiolucent lesion with well-defined border. However, careful interpretation revealed a non-corticated border and floating tooth appearance that were the characteristic radiographic features for the differential diagnosis. Early clinical signs of eosinophilic granuloma can occur in the jaw and a bony destructive lesion might be mistaken for periodontitis or an odontogenic cystic lesion; therefore, careful interpretation of radiographs should be emphasized.

Comparison of FEA with Condition Monitoring for Real-Time Damage Detection of Bearing Using Infrared Thermography Techniques (적외선열화상을 이용한 베어링 실시간 손상검출 상태감시의 전산수치해석 비교)

  • Kim, Hojong;Kim, Wontae
    • Journal of the Korean Society for Nondestructive Testing
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    • v.35 no.3
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    • pp.185-192
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    • 2015
  • Since real-time monitoring systems, such as early fault detection, have been very important, an infrared thermography technique was proposed as a new diagnosis method. This study focused on damage detection and temperature characteristic analysis of ball bearings using the non-destructive, infrared thermography method. In this paper, for the reliability assessment, infrared experimental data were compared with finite element analysis (FEA) results from ANSYS. In this investigation, the temperature characteristics of ball bearing were analyzed under various loading conditions. Finally, it was confirmed that the infrared thermography technique was useful for the real-time detection of damage to bearings.

Monitoring of fracture propagation in brittle materials using acoustic emission techniques-A review

  • Nejati, Hamid Reza;Nazerigivi, Amin;Imani, Mehrdad;Karrech, Ali
    • Computers and Concrete
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    • v.25 no.1
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    • pp.15-27
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    • 2020
  • During the past decades, the application of acoustic emission techniques (AET) through the diagnosis and monitoring of the fracture process in materials has been attracting considerable attention. AET proved to be operative among the other non-destructive testing methods for various reasons including their practicality and cost-effectiveness. Concrete and rock structures often demand thorough and real-time assessment to predict and prevent their damage nucleation and evolution. This paper presents an overview of the work carried out on the use of AE as a monitoring technique to form a comprehensive insight into its potential application in brittle materials. Reported properties in this study are crack growth behavior, localization, damage evolution, dynamic character and structures monitoring. This literature review provides practicing engineers and researchers with the main AE procedures to follow when examining the possibility of failure in civil/resource structures that rely on brittle materials.

A study about frequency domain analysis of impact-wave for detecting of structural defects in the concrete structure (구조물의 안전진단을 위한 충격파의 주파수 영역 탐사에 관한 연구)

  • Suh Baeksoo;;Kim Hyoungjun;Lee Sangchul
    • 한국지구물리탐사학회:학술대회논문집
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    • 2005.05a
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    • pp.165-180
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    • 2005
  • Impact seismic wave test is a method for nondestructive testing of concrete structure using of stress wave which is propagated and reflected from internal flaws within concrete structure and external surface, In this study, we performed non-destructive testing using impact seismic wave test for safety diagnosis of civil engineering structures. For this, I've compared and analized the result in the way of reflective method mostly using on one-dimension such as tunnel lining, and penetration method using the way of cross hole and tomography.

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Development of Health Monitoring System Using Self Magnetization Magnetostrictive Sensor (자기자화자왜센서를 이용한 설비 off-line Health Monitoring 시스템 개발)

  • Kim, Yi-Gon;Moon, Hong-Sik;Kim, Jun;Kim, Ji-Hyeon
    • Journal of the Korean Institute of Intelligent Systems
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    • v.22 no.4
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    • pp.481-486
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    • 2012
  • This thesis examines the development and application of 'Health Monitoring System' which monitors periodically the state of a pipe of petrochemical plant by using magnetostrictive sensor technology. The existing guided-wave inspection methods cannot be applied to welding part inspection in pipe, and has a limit of precision when applied to general parts because of noise, reflected waves, and so on. This technology uses the information on displacement of a defect through periodic monitoring, which makes more precise inspection, and can be utilized very usefully in a petrochemical plant.

A Study on Real-Time Fault Monitoring Detection Method of Bearing Using the Infrared Thermography (적외선 열화상을 이용한 베어링의 실시간 고장 모니터링 검출기법에 관한 연구)

  • Kim, Ho-Jong;Hong, Dong-Pyo;Kim, Won-Tae
    • Journal of the Korean Society for Nondestructive Testing
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    • v.33 no.4
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    • pp.330-335
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    • 2013
  • Since real-time monitoring system like a fault early detection has been very important, infrared thermography technique as a new diagnosis method was proposed. This study is focused on the damage detection and temperature characteristic analysis of ball bearing using the non-destructive infrared thermography method. In this paper, for the reliability assessment, infrared experimental data were compared with the frequency data of the existing. As results, the temperature characteristics of ball bearing were analyzed under various loading conditions. Finally it was confirmed that the infrared technique was useful for real-time detection of the bearing damages.