• Journal of KSNVE
• /
• v.25 no.5
• /
• pp.15-18
• /
• 2015

• Journal of the Korean Society for Nondestructive Testing
• /
• v.32 no.1
• /
• pp.7-11
• /
• 2012

For fault detection about the abrasion stage of rotational machineries under the dynamic loading conditions unlike the traditional diagnosis method used in the past decade, the infrared thermographic method with its distinctive advantages in non-contact, non-destructive, and visible aspects is proposed. In this paper, by applying a rotating deep-grooved ball bearing, passive thermographic experiments were conducted as an alternative way to proceeding the traditional fault monitoring on spectrum analyzer. As results, the thermographic experiment was compared with the traditional vibration spectrum analysis to evaluate the efficiency of the proposed method. Based on the results obtained as NDT, the temperature characteristics and abnormal fault detections of the ball bearing according to the abrasion stage were analyzed.

• KIPS Transactions on Computer and Communication Systems
• /
• v.9 no.2
• /
• pp.25-30
• /
• 2020

The thermal image system was widely used in the defence-related industry because of detect infrared light from the object without light. but, as the demand in the security system and automobile market increases, the civilian industry are expanding to the private sector. There are difficult to apply various requirement because of previous systems are based by FPGA, so it need new system that apply to various requirement. The proposed paper is thermal image processing system using common image processor. It has various requirement and scalable to support image input/output interface and device driver. If it is used to proposed system, it reduce development cost and period than previous system based FPGA. Because there has very high accessibility. In addition, it expect to have satisfaction of customer requirements, development cost, development period, release date of product.

• KIPS Transactions on Computer and Communication Systems
• /
• v.9 no.1
• /
• pp.1-8
• /
• 2020

The thermal image device support image to detect infrared light from the object without light. It can use not only defence-related industry, but also civilian industry. This paper presents a new thermal image processing module using common image processor. The proposed module shows 10~20% performance improvement with normal mode and 50% performance improvement with sleep mode compared with the previously thermal image module based FPGA. and it guarantees high scalability according to modular system. In addition, the proposed module improves modulation and reuse, so it expect to have reduction of development period, low development cost. various application. In addition, it expect to have satisfaction of customer requirements, development design, development period, release date of product.

• Journal of the Korean Society for Nondestructive Testing
• /
• v.27 no.4
• /
• pp.321-327
• /
• 2007

In lock-in thermography, a phase difference between the defect area and the healthy area indicates the qualitative location and size of the defect. To accurately estimate these parameters, the shearing-phase technique has been employed which gives the shearing-phase distribution. The shearing-phase distribution has maximum, minimum, and zero points that help determine quantitatively the size and location of the subsurface defect. In experiment, the proposed technique is verified with artificial specimen and these related factors are analyzed.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2023.05a
• /
• pp.740-742
• /
• 2023

객체 인식 연구에 있어서 딥러닝 기반의 사람 인식에 있어서 많은 연구들이 공개되고 있다. 특히 화재사고에 있어서 연기로 인해 가시성이 떨어져 인명구조에 어려움이 발생한다. 이에 열화상 카메라와 딥러닝을 통해 사람을 인식하는 기술이 연구되고 있다. 기존 연구에서는 열화상 카메라와 YOLO 딥러닝을 통해 사람을 인식하는데 95%의 성능을 보였지만, YOLO는 그리드 셀에서 하나의 분류만하기 때문에 물체에 가려진 사람을 판별하는데 정확도가 낮았다. 본 논문에서는 이와 같은 한계를 극복하기 위해 기존 Faster R-CNN 알고리즘을 사용한다. 신체부위 Guided Attention mechanism을 사용하여 가중치를 준 Feature Map을 RPN에 적용시켜 학습모델을 구현한다면 더 높은 정확도를 얻을 수 있다. 향후 본 논문에서 제안하는 기법은 많은 실험과 다양한 데이터 셋을 통해 실질적인 검증을 할 예정이다.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.27 no.6
• /
• pp.30-38
• /
• 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.

• Journal of the Korean Society for Nondestructive Testing
• /
• v.29 no.1
• /
• pp.10-14
• /
• 2009

Heat generation mechanism of ultrasound infrared thermography is still not well understood, yet and there are two reliable assumptions of heat generation, friction and thermo-mechanical effect. This paper investigates the principal cause of heat generation at fatigue crack with experimental and numerical approach. Our results show most of heat generation is contributed by friction between crack interface and thermo-mechanical effect is a negligible quantity.

• Journal of the Korea Concrete Institute
• /
• v.20 no.6
• /
• pp.681-687
• /
• 2008

This study presents a technique to quantitatively measure the corrosion level of a reinforcing bar using infrared thermography system. We found out electric heating method having an important effect on thermal data in previous study. This study purposed an efficient way for grip standardization to reduce constriction resistance problem, and providing reliable thermal data using infrared thermographic method. Using vise type earth clamp, the surface resistance of rebar was smaller than that of traditional plier type earth clamp through temperature-distribution relationship. Also this study contains experiments with toque wrench to improve heating contact problem.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.37 no.4
• /
• pp.443-446
• /
• 2013

An infrared thermography technique can be used to inspect a large area simultaneously and to detect defects such as cracks or delaminations in real time. Infrared thermography is a technique in which visual images are formed from the infrared range from subjects according to their thermal radiation. The molecules of all objects are disturbed by heat, and the molecular motion becomes more active when the temperature rises and less active when the temperature falls. In this study, the applicability and feasibility of ultrasound thermography for detecting defects in an engine block, which is a key component in the automobile industry, were verified. A nondestructive reliability test was conducted to study the defects, after which the results were analyzed.