• 비파괴검사학회지
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• 제31권2호
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• pp.134-138
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• 2011

회전기기의 고장 탐지에 있어 기존의 진단법과 달리 동적 하중조건 하에서 비접촉, 비파괴의 적외선 열화상 기법이 제안된다. 본 논문에서는 단열 깊은 홈 볼 베어링을 시편으로 하여, 회전기기의 기존의 고장 진단법 대신 수동형 열화상 기법을 이용한 시험을 수행하였다. 추가적으로, 제안된 방법의 효율성을 평가하기 위해 기존의 진동 스펙트럼 분석법을 적용하여 열화상 시험법을 비교하였다. 시혐의 결과로써, 동적 하중조건 하 볼 베어령의 온도분포 특성이 철저히 분석되었다.

• 대한한방부인과학회지
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• 제26권3호
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• pp.85-92
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• 2013

Objectives: The purpose of this study is to find diagnostic points and define the cut off values of hot flashes by using digital infrared thermographic imaging. Methods: Thermographic images of 75 patients with hot flashes (HF, n=35) and non-hot flashes (NHF, n=40) were retrospectively reviewed. We used the temperature difference between Ex-HN3 and CV17, LU4, CV12, CV4 for diagnosing hot flashes. The temperature differences of between two groups were analysed using independent samples t-tests. The cut off values were calculated by received operating characteristic curve analysis. Analyses were undertaken using SPSS version 17.0. and p-value of <0.05 was considered significant. Results: The temperature difference Ex-HN3 and LU4 were the most significantly different between groups (p<0.001). Using receiver operating characteristic curve analysis, the sensitivity, specificity, and area under the curve were 65.7%, 72.5%, 0.729, respectively. The optimum cut off value was defined as $1.00^{\circ}C$. Conclusions: These results suggest that the digital infrared thermographic imaging is a reliable instrument for estimating hot flashes.

• 한국방재학회:학술대회논문집
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• 한국방재학회 2007년도 정기총회 및 학술발표대회
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• pp.425-428
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• 2007

In order to measure corrosion level of reinforcement rebar which is inside reinforced concrete structure, infrared thermographic technique was employed. Experimental test parameters were ambient temperatures, various levels of corrosion states. After analysis of temperature distributions of concrete surface, the amount of heat flux from the concrete surface is directly proportional to the corrosion level which is inside of concrete.

• 비파괴검사학회지
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• 제32권1호
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• pp.7-11
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• 2012

기존 진단법과 달리 동적 하중조건하 회전체의 마모 단계에 따른 결함 진단을 위해 비접촉, 비파괴의 적외선 열화상 기법이 제안된다. 본 연구에서는 시험시편인 단열 깊은 홈의 볼 베어링을 설정하여 기존의 스펙트럼 분석과 같은 고장탐지법에 대한 대안으로써 수동형 열화상시험이 수행되었다. 본 연구로부터, 적외선 열화상시험은 신뢰성을 평가하기 위해 기존 진동 스펙트럼 분석시험과 비교, 분석되었다. 연구의 비파괴시험의 결과로써, 마모 단계에 따른 볼 베어링의 온도 특성이 분석되었다.

• 비파괴검사학회지
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• 제30권2호
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• pp.116-120
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• 2010

차축과 차륜으로 구성되는 철도차량 윤축은 차량의 운행과 관련하여 안전과 직결되는 중요한 철도 부품의 하나이다. 본 연구에서는 철도차량의 차축 재료의 인장파괴거동에 대한 특성을 분석하였다. 20년 이상 운행된 전기기관차 및 디젤전기기관차의 차축 시편에 대하여 연장시험을 수행하였다. 인장시험 동안 시편의 파괴특성을 모니터링하기 위해 고속 적외선카메라가 사용되었는데, 인장시험 동안의 시편 표변의 온도 변화를 모니터링하여 온도 분포로부터 인장파괴거동을 설명하고 파괴모드를 규명하고자 하였다.

• 대한한방부인과학회지
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• 제25권3호
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• pp.95-102
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• 2012

Purpose: The purpose of this study is to define the cut off values of cold hypersensitivity of hands by using digital infrared thermographic imaging(DITI). Methods: Thermographic images of 130 patients with cold hypersensitivity of hands(CHHG, n=65) and non-cold hypersensitivity of hands(NCHHG, n=65) were retrospectively reviewed. We used the temperature difference the palm(PC8) and the upper arm(LU4) for diagnosing cold hypersensitivity of hands. The temperature differences of between two groups were analysed using independent samples t-tests. The cut off values were calculated by ROC curve analysis. Analyses were undertaken using SPSS version 17.0. P value of < 0.05 was considered significant. Results: The temperature difference the palm(PC8) and the upper arm(LU4) were significantly different between groups(p < 0.001). Using receiver operating characteristic curve analysis, the sensitivity, specificity, and area under the curve were 70.8%, 73.8%, respectively both hands. The AUC was 0.822 on right hand and 0.818 on left hand. The optimum cut-off value was defined as $-0.05^{\circ}C$. Conclusions: These results suggest that DITI is a reliable instrument for estimating the cold hypersensitivity of hands.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.964-968
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• 2008

Infrared thermography using high-speed infrared camera has been recognized as a powerful method for various potential applications, such as nondestructive inspection, failure analysis, stress analysis, and medical fields, due to non-contact, high-speed, and high spatial resolution at various temperature ranges. In this investigation, damage evolution due to generation of hot spots on railway brake disc was investigated using the infrared thermography method. A high-speed infrared camera was used to measure the surface temperature of brake disc as well as for in-situ monitoring of hot spot evolution. From the thermographic images, the observed hot spots and thermal damage of railway brake disc during braking operation were qualitatively analyzed. Moreover, in this investigation, the previous experimental and theoretical studies on hot spots phenomenon were reviewed, and the current experimental results were introduced and compared with theoretical prediction.

• 비파괴검사학회지
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• 제34권2호
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• pp.128-134
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• 2014

Infrared thermography is an emerging approach to non-contact, non-intrusive, and non-destructive inspection of various solid materials such as metals, composites, and semiconductors for industrial and research interests. In this study, data processing was applied to infrared thermography measurements to detect defects in metals that were widely used in industrial fields. When analyzing experimental data from infrared thermographic testing, raw images were often not appropriate. Thus, various data analysis methods were used at the pre-processing and processing levels in data processing programs for quantitative analysis of defect detection and characterization; these increased the infrared non-destructive testing capabilities since subtle defects signature became apparent. A 3D finite element simulation was performed to verify and analyze the data obtained from both the experiment and the image processing techniques.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2017년도 춘계 종합학술대회 논문집
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• pp.101-102
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• 2017

This study of purpose was to evaluate the changes in hands and feet temperature by applying massage and paraffin bath.. The subject of this study was 30 university healthy students. Subjects were divided into paraffin bath group and massages group. The digital infrared thermographic imaging was used for thermographic analysis. The visual analog scale was used for subjective information about the degree of cold sensitivity and cold stress test was used for analyzing the temperature recovery rate. After the interventions showed that temperature difference of the right hand and temperature difference of the left hand are less in the paraffin group than the massage group. When applied paraffin bath and massage to the cold hypersensitivity patient the massage group showed difference in the visual analog scale and the paraffin group showed difference in the temperature of the right hand, left hand, left foot and in the visual analog scale. Paraffin bath treatment seems to be useful to patients with cold hypersensitivity on hands and feet.

• Geomechanics and Engineering
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• 제23권6호
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• pp.503-512
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• 2020

Mining activities focus on the production of mineral resources for energy generation and raw material requirements worldwide and it is a known fact that shallow reserves become scarce. For this reason, exploration of new resources proceeds consistently to meet the increasing energy and raw material demand of industrial activities. Rock mechanics has a vital role in underground mining and surface mining. Devices and instruments used in laboratory testing to determine rock mechanics related parameters might have limited sensing capability of the failure behavior. However, methodologies such as, thermal cameras, digital speckle correlation method and acoustic emission might enable to investigate the initial crack formation in detail. Regarding this, in this study, thermographic analysis was performed to analyze the failure behaviors of different types of rock specimens during uniaxial compressive strength experiments. The energy dissipation profiles of different types of rocks were characterized by the temperature difference recorded with an infrared thermal camera during experiments. The temperature increase at the failure moment was detected as 4.45℃ and 9.58℃ for andesite and gneiss-schist specimens, respectively. Higher temperature increase was observed with respect to higher UCS value. Besides, a temperature decreases of about 0.5-0.6℃ was recorded during the experiments of the marble specimens. The temperature change on the specimen is related to release of radiation energy. As a result of the porosity tests, it was observed that increase in the porosity rate from 5.65% to 20.97% can be associated to higher radiation energy released, from 12.68 kJ to 297.18 kJ.