• 한국정밀공학회지
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• 제30권7호
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• pp.687-693
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• 2013

The service conditions of railway cars have become more difficult in recent years due to increased speed. Faulty components in the railcars may result in service interruption, or in extreme cases, derailment. Thus, it is important to diagnose and monitor the main components of railcars. Temperature monitoring is one of the basic methods used to diagnose abnormal conditions in the main components of railway cars, such as in bearings, reduction gears, and traction motors. In this study, we developed a monitoring system for the main components, using an infrared thermography technique. This technique has the advantage of infrared thermal camera imaging of temperature contours in the components. Various hardware and software components of the monitoring system are used to acquire the sensor data, to identify potential problems in railcar operation.

• 융합보안논문지
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• 제22권2호
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• pp.21-26
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• 2022

마스크 착용은 COVID-19 감염을 예방하기 위한 효과적인 방안이다. 적외선 열화상 기반의 온도 측정과 신원 인식 시스템이 기업에서 널리 사용되고 있는 상황에서 마스크 감지를 위한 연구는 필수적이다. 최근 비전분야에 소개된 MTCNN은 객체 인스턴스 세분화를위한 개념적으로 간단하고 유연하며 일반적인 프레임 워크를 제시한다. 본 논문에서는 열적외선 카메라로부터 획득한 열감지영상에서 발열체인 인스턴스에 대해 발열부위의 세그멘테이션을 생성하는 동시에 이미지 내의 오브젝트 발열부분을 효율적으로 탐색하는 알고리즘을 제안한다. MTCNN(Multi-task Cascaded Convolutional Networks) 기법은 바운딩 박스 인식을 위해 기존 브랜치와 병렬로 객체 마스크를 예측하기 위한 브랜치를 추가한 알고리즘이다. MTCNN은 다른 작업으로 일반화하기 용이하다. 본 논문에서는 MTCNN기반 적외선 열영상 검출알고리즘을 제안하여 RGB영상에서 구별할 수 없는 마스크 착용 여부를 탐지하였다.

• 한국의학물리학회:학술대회논문집
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• 한국의학물리학회 2002년도 Proceedings
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• pp.471-473
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• 2002

Public concerns associated with the electromagnetic field (EMF) exposures from mobile phones on human body are increased. Although studies on the effects of the EMF exposures on human have been carried out for a long time, it is not proved yet whether the EMF effect is harmful or not. Based on the scientific results by experts, EMF exposure limits have been regulated as a precautionary approach on the assumption that the EMF effect may be harmful. It is well known that absorbed EMF can be transformed into heat within biological tissues and that thermal effects are related with the specific absorption rate (SAR) distribution. However, the relative magnitude and distribution of the energies are not well defined. Although there is comprehensive information of the thermal effects, most of them come from animal and in vitro studies. Considerable efforts have been made to analyze the EMF absorption model while the actual temperature in the human body has been rarely measured. Temperature changes on the face of a healthy male volunteer were studied. A digital mobile phone of 1.8GHz was used. A digital infrared imaging system (IRIS-5000, Medicore, Seoul, Korea) was applied to take infrared pictures of the face every minute while the volunteer talked over the mobile phone for 20 minutes. The specification of the imaging system was as follows: Temperature resolution = 0.1$^{\circ}C$; Range of temperature measurement = 17～40$^{\circ}C$; Pixel size = 0.9mm ${\times}$ 0.9mm; Frame time = 2.6s; Active temperature of detector = 77$^{\circ}$K. The result showed that temperature of the ear region was increased during the phone call and the region of the temperature increase on the face was expanded as the phone call time increased. Further study is necessary to investigate the temperature rise analytically and quantitatively.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1992년도 하계학술대회 논문집 B
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• pp.1250-1254
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• 1992

This paper describes the designed and fabricated thermal imaging system with the SPRITE(Signal PRocessing in The Element) detector, operating in the 3-12 micron band. This system consists of an afocal telescope, a scan unit containing the SPRITE detector, an electronic processor unit and a cooler. The optical scan system utilizing rotating polygon and oscillating mirror, is 2-dimensional serial/parallel scan type using five elements of the detector. And the electronic processor unit performs digital scan conversion to reform the parallel data stream into serial analog data compatable with conventional RS-170 video. The scan field of view is 40 ${\times}$ 26.7 and the MRTD(Minium Resolvable Temperature Difference) is 0.6 K at 7.5 cycles/mm. The acquired thermal image indicates that this system has a satisfactory performance.

• Journal of Biosystems Engineering
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• 제24권5호
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• pp.439-444
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• 1999

Automated greenhouse production systems often require crop growth monitoring involving accurate quantification of plant physiological properties. Conventional methods are usually burdensome, inaccurate, and harmful to crops. A thermal image analysis system can accomplish rapid and accurate measurements of physiological-property changes of stressed crops. In this research a thermal imaging system was used to measure the leaf-temperature changes of several crops according to water deficit. Thermal images were obtained from lettuce, cucumber, pepper, and chinese cabbage plants. Results showed that there were significant differences in the temperature of stressed plants and non-stressed plants. The temperature differences between these two group of plants were 0.7 to 3$^{\circ}C$ according to species.

• 한국측량학회지
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• 제34권6호
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• pp.619-627
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• 2016

Cells of a PV (photovoltaic) module can suffer defects due to various causes resulting in a loss of power output. As a malfunctioning cell has a higher temperature than adjacent normal cells, it can be easily detected with a thermal infrared sensor. A conventional method of PV cell inspection is to use a hand-held infrared sensor for visual inspection. The main disadvantages of this method, when applied to a large-scale PV power plant, are that it is time-consuming and costly. This paper presents an algorithm for automatically detecting defective PV panels using images captured with a thermal imaging camera from an UAV (unmanned aerial vehicle). The proposed algorithm uses statistical analysis of thermal intensity (surface temperature) characteristics of each PV module to verify the mean intensity and standard deviation of each panel as parameters for fault diagnosis. One of the characteristics of thermal infrared imaging is that the larger the distance between sensor and target, the lower the measured temperature of the object. Consequently, a global detection rule using the mean intensity of all panels in the fault detection algorithm is not applicable. Therefore, a local detection rule was applied to automatically detect defective panels using the mean intensity and standard deviation range of each panel by array. The performance of the proposed algorithm was tested on three sample images; this verified a detection accuracy of defective panels of 97% or higher. In addition, as the proposed algorithm can adjust the range of threshold values for judging malfunction at the array level, the local detection rule is considered better suited for highly sensitive fault detection compared to a global detection rule. In this study, we used a panel area extraction method that we previously developed; fault detection accuracy would be improved if panel area extraction from images was more precise. Furthermore, the proposed algorithm contributes to the development of a maintenance and repair system for large-scale PV power plants, in combination with a geo-referencing algorithm for accurate determination of panel locations using sensor-based orientation parameters and photogrammetry from ground control points.

• 한국초전도저온공학회:학술대회논문집
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• 한국초전도저온공학회 2003년도 추계학술대회 논문집
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• pp.320-323
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• 2003

This paper presents the results of a series of performance tests for the Stilting cryocooler. A free piston and free displacer(FPFD) Stilting cryocooler for cooling infrared and cryo-sensors is currently under development at KIMM. Our coolers are specifically designed to work in the thermal imaging device and to meet requirements such as cooling capacity, COP and high reliability. In this work, Stilting cryocooler is designed, manufactured and fabricated, and performance characteristics for the cooling capacity / applied input power and cool down time are investigated. This cooler delivers approximately 0.9W cooling at 80K for 30W ~ 40W of input power. And, It takes approximately 2 minutes to cool down to 80K at the ambient temperature of 23$^{\circ}C$.

• 한국초전도저온공학회:학술대회논문집
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• 한국초전도저온공학회 2003년도 추계학술대회 논문집
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• pp.167-170
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• 2003

This paper presents the results of a series of performance tests for the Stilting cryocooler. A free piston and free displacer(FPFD) Stilting cryocooler for cooling infrared and cryo-sensors is currently under development at KIMM. Our coolers are specifically designed to work in the thermal imaging device and to meet requirements such as cooling capacity, COP and high reliability. In this work, Stilting cryocooler is designed, manufactured and fabricated, and performance characteristics for the vibration, acoustic noise, EMI and leak rate are evaluated. Vibration outputs are measured to 20KHz for compressor and expander, respectively. And, the objective of noise test is a noise level, less than 30㏈ at 5 m. EMI tests are carried out according to the standard MIL-STD-461C tests RE01 and RE02. Leak test for the Stilting cryocooler is performed by bombing method.

• 시스템엔지니어링학술지
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• 제1권1호
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• pp.1-13
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• 2005

The purpose of this paper analyze development feasibility and alternatives for infrared detector development in both technology and cost. Infrared Detector is core component of Thermal Imaging System and developed by ADD from 2006 10 2008 year. We got raw input data from development and technical expert, and then analyze cost and technology for development feasibility, and alternatives study. Technology level is analyzed by TRL(Technology Readiness Level) and AOA(Analysis of Alternatives) is done by development cost estimate. Estimating the development cost, we use SEER-H that is parametric cost estimating tool based on Knowledge Base. This study can help those who are related to the cost and development feasibility analysis of other weapon systems.

• 한국전기전자재료학회논문지
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• 제24권5호
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• pp.387-391
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• 2011

A uncooled infrared ray sensor used in an infrared thermal imaging detector has many advantages. But because the uncooled infrared ray sensor is made by MEMS (micro-electro-mechanical system) process variation of offset is large. In this paper, to solve process variation of offset a ROIC for uncooled infrared ray sensor that has process variation of offset compensation technique using differential delta sampling and reference signal compensation circuit was proposed. As a result of simulation that uses the proposed ROIC, it was possible to acquire compensated output characteristics without process variation of offsets.