• 제목/요약/키워드: thermal imaging

검색결과 622건 처리시간 0.049초

Characterisation of Tensile Deformation through Infrared Imaging Technique

  • B. Venkataraman, Baldev Raj;Mukhophadyay, C.K.
    • 비파괴검사학회지
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    • 제22권6호
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    • pp.609-620
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    • 2002
  • It is well known that during tensile testing, a part of the mechanical work done on the specimen is transformed into heat energy. However, the ultimate temperature rise and the rate of temperature rise is related to the nature of the material, conditions of the test and also to the deformation behaviour of the material during loading. The recent advances in infrared sensors and image/data processing techniques enable observation and quantitative analysis of the heat energy dissipated during such tensile tests. In this study, infrared imaging technique has been used to characterise the tensile deformation in AISI type 316 nuclear grade stainless steel. Apart from identifying the different stages during tensile deformation, the technique provided an accurate full-field temperature image by which the point and time of strain localization could be identified. The technique makes it possible to visualise the region of deformation and failure and also predict the exact region of fracture in advance. The effect of thermal gradients on plastic flow in the case of interrupted straining revealed that the interruption of strain and restraining at a lower strain rate not only delays the growth of the temperature gradient, but the temperature rise per unit strain decreases. The technique is a potential NDE tool that can be used for on-line detection of thermal gradients developed during extrusion and metal forming process which can be used for ensuring uniform distribution of plastic strain.

동절기 온실의 열 손실에 관한 실태조사 - 경남지역을 중심으로 - (Current on the Heat Loss in Greenhouses during Winter Season - Case Study Based on Gyeongnam Area -)

  • 임재운;윤성욱;김현태;윤용철
    • 생물환경조절학회지
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    • 제22권1호
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    • pp.73-79
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    • 2013
  • 본 연구에서는 온실의 열손실을 최소화할 방안을 모색하기 위하여 경남지역에 있는 시설 농가를 대상으로 열화상 카메라를 이용하여 열손실 사례에 대한 실태조사를 실시하였다. 그 결과를 요약하면 다음과 같다. 치마처리 전 후의 두 실험구간의 온도차는 각각 $2.0{\sim}3.0^{\circ}C$$1.0{\sim}2.0^{\circ}C$ 정도인 것을 알 수 있다. 열화상 기기에 의해 계측된 온도와 온도 센서에 의해 계측된 온도와는 상관 관계가 큰 것으로 나타났다. 실태조사 지역 간에 큰 차이는 없었지만 보온용 부직포가 1층인 경우와 2층인 경우를 보면, 1층이 2층에 비해 상대적으로 열손실 크게 나타났다. 그리고 전체적으로 온실의 형태와 무관하게 측장부분과 수평보온커튼의 틈새, 측면과 전 후면 보온용 부직포의 이음부분이 완전히 밀폐되지 않아 열손실이 상대적으로 큰 것으로 나타났다. 특히, 파손된 피복재나 출입문, 환기구, 박공, 바닥부근 등에서 틈새가 생겨서 많은 양의 열이 손실되고 있었다.

과민성대장증후군(過敏性大腸症候群) 환자(患者)에 대한 적외선(赤外線) 체열영상촬영기기(體熱映像撮影器機)( D.I.T.I)의 응용연구 (The Clinical Studies on the Irritable Syndrome by Using D.I.T.I.)

  • 김달래;백태현
    • 대한한방내과학회지
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    • 제21권1호
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    • pp.7-12
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    • 2000
  • Objectives : This studies were performed to investigate the correlation between the treatment effects and the changes of the thermal differences at the pre and post-treatment by using the digital infrared computer thermographic imaging (D.I.T.I) to the irritable colon syndrome 30 patients. Methods : The extracts of the gwakhyangjunggisan were administerd to the patients by oral method three times per day during four weeks. we selected the Chung-Wan($CV_{12}$), Chunchu($S_{25}$). Hapkok($LI_4$), Naegwan($P_6$), Yongdo($H_4$) acupoints and treated the patients two times per week during four weeks. One week later, we investigated the changes of the pressure pain around left side Pokkyol($SP_{14}$), the symptoms. and the skin temperature changes on Pokkyol($SP_{14}$) and Kimun($LR_{14}$) around, by using the D.I.T.I. Results : In the correlation between the severity of the pressure pain around left side Pokkyol($SP_{14}$) and the thermal differences on Pokkyol($SP_{14}$) and Kimun($LR_{14}$) around, before the treatment, the more the pain was severe, the more the skin temperature was differential significantly. In the correlation between the severity of the symptoms and the thermal differences on Pokkyol($SP_{14}$) and Kimun($LR_{14}$) around, before the treatment, the more the symptom was severe, the more the skin temperature was differential significantly. In the changes of the pressure pain around left side of Pokkyol($SP_{14}$), the improved were significantly higher than the unimproved. In the changes of the symptoms, the improved were significantly higher than the unimproved. In the correlation between the changes of the pressure pain around left side Pokkyol($SP_{14}$) and the changes of the thermal differences at the pre and post- treatment, the more the pain was improved, the more the thermal change was widened significantly. In the correlation between the changes of the symptoms and the changes of thermal differences at the pre and post-treatment, the more the symptom was improved. the more the thermal change was widened significantly. Conclusions : Above the results, the treatments was effective and the digital infrared computer thermographic imaging (D.I.T.I) was useful to prove the improvements of the pressure pain and the symptom with the irritable bowel syndrome patients.

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크레인 디스크 패드 모니터링을 위한 스마트폰 기반의 열영상 진단 시스템 개발 (Development of Smart-phone based Thermal Imaging Diagnostic System for Monitoring Disc Pads of Crane)

  • 오연재;박경욱;김응곤
    • 한국전자통신학회논문지
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    • 제9권12호
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    • pp.1397-1404
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    • 2014
  • 그랩 크레인은 부두 항만으로 모래 및 토사가 퇴적이 되거나, 해저 공사를 하기 위해 다목적으로 사용된다. 그립 크레인의 구성 요소 중 와이어 드럼과 디스크 브레이크 패드는 핵심적인 소모품으로 많은 열이 발생되며 교체 시 가격이 매우 비싸다는 단점이 있다. 본 논문에서는 그랩 크레인의 와이어 드럼에 작용되는 디스크 브레이크 패드에 대한 열화상 진단 시스템을 제안한다. 제안된 시스템은 브레이크 고장 및 디스크 패드 손상 전에 디스크 및 패드 표면의 온도가 비정상적으로 분포하는 특징을 이용하여 열화상을 통해 패드 열 진단 분석을 수행한다. 따라서 기계 부품의 이상을 고장 전에 미리 발견하여 고장으로 인한 피해를 방지할 수 있으며, 과부하 유무를 상시체크하면서 크레인을 작동시켜 패드의 수명 연장과 비용을 절감할 수 있다.

Study on Grain Boundaries in Single-layer Graphene Using Ultrahigh Resolution TEM

  • Lee, Zong-Hoon
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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    • pp.107-107
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    • 2012
  • Recently, large-area synthesis of high-quality but polycrystalline graphene has been advanced as a scalable route to applications including electronic devices. The presence of grain boundaries (GBs) may be detrimental on some electronic, thermal, and mechanical properties of graphene, including reduced electronic mobility, lower thermal conductivity, and reduced ultimate mechanical strength, yet on the other hand, GBs might be beneficially exploited via controlled GB engineering. The study of graphene grains and their boundary is therefore critical for a complete understanding of this interesting material and for enabling diverse applications. I present that scanning electron diffraction in STEM mode makes possible fast and direct identification of GBs. We also demonstrate that dark field TEM imaging techniques allow facile GB imaging for high-angle tilt GBs in graphene. GB mapping is systematically carried out on large-area graphene samples via these complementary techniques. The study of the detailed atomic structure at a GB in suspended graphene uses aberration-corrected atomic resolution TEM at a low kV.

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Temperature Measurement of Photovoltaic Modules Using Non-Contact Infrared System

  • Jovanovic, Ugljesa;Mancic, Dragan;Jovanovic, Igor;Petrusic, Zoran
    • Journal of Electrical Engineering and Technology
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    • 제12권2호
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    • pp.904-910
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    • 2017
  • This paper presents temperature measurement of solar photovoltaic modules using the custom-made system composed of an infrared temperature sensor and a microcontroller. The obtained measurement results are processed, displayed and stored on a PC using the custom-made virtual instrument. The proposed system overcomes some of the problems related to the contact sensor application, and at the same time offers accurate readings and better flexibility. The proposed system is especially suitable for applications where the cost is a limiting factor in the choice of measuring system. The conducted analysis and the obtained results have shown an excellent accuracy of the proposed system in comparison to a high quality thermal imaging camera used as the reference instrument.

System Design of Sunshield on the MSC

  • Kim, Young-Soo;Lee, Eung-Shik;Woo, Sun-Hee
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2002년도 Proceedings of International Symposium on Remote Sensing
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    • pp.815-820
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    • 2002
  • MSC as a payload of KOMPSAT-2 is an optical telescope for earth imaging on a sun-synchronous orbit. The MSC is a Ritchey-Chretien type telescope composed of hyperbolic primary and secondary mirrors with focal correcting lenses. Their relative positions should be kept aligned during imaging operation. However, the MSC is exposed to adverse thermal environment on orbit which can have some impacts on optical performance as well as structural endurance. Solar incidence can cause non-uniform temperature rise on the tube which entails unfavorable thermal distortion. Three options were proposed, which were internal shield, external mechanical shield and spacecraft maneuvering. After the trade-off studies, internal sun shield was selected as a realistic and optimal solution to minimize the effect of the solar radiation. In this paper, pros and cons are explained for the three possible choices and a design of the internal shield is discussed.

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예광제 조성이 연소 불꽃의 스펙트럼 및 광도에 미치는 영향 (Effect of Tracer Composition on Spectrum and Intensity of Burning Flame)

  • 권순길;황준식;이상무
    • 한국군사과학기술학회지
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    • 제9권4호
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    • pp.90-96
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    • 2006
  • Computer simulation was carried out to develop the tracer composition of a high performance to be able to be observed by not only the naked eye but also the thermal imaging system attached to the weapon system. The results of computer simulation show that the optimum Mg content among the trace compositions is about 40% and the formulation consisted of Viton A has a higher flame temperature compared with that of chloride compound. But the only use of Viton A radiates a yellow light and the composition adding a chloride compound radiates the red light. The light intensity of the tracer composition involving Viton A is higher than that of chloride compound. The tracer composition involving Viton A shows more clear images in case of all tests.

상관이중표본화 신호처리를 이용한 적외선 열상시스템의 잔여불균일성 개선 (Improvement Residual Non-uniformity in Thermal Imaging System Using Correlated Double Sample Signal Processing)

  • 석정엽;장성군;김성운;여보연
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2008년도 하계종합학술대회
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    • pp.1043-1044
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    • 2008
  • In this study, a novel algorithm of the improvement residual non-uniformity (RNU) in thermal imaging system is proposed using correlated double sample signal processing. The proposed method attempts to eliminate offset variation of ROIC in IR detector causing the variation of FPA (focal plane array) temperature and suppling power. Experimental results show that the proposed method confirmed a better performance than the existing RNU system.

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위증(療證)으로 진단한 하지마비 환자의 치험 1례 (Clinical Observation on 1 Case of Both Leg Paralysis Patient Diagnosed Wei Symptom)

  • 위통순
    • 동의생리병리학회지
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    • 제20권3호
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    • pp.748-752
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    • 2006
  • Wei symptom(?證) is symptom that reveals muscle relaxation without contraction and muscle relaxation occurs in the lower or upper limb, in severe case, leads to death. This is the clinical report about the Wei symptom(?證)-patient doubt as Transverse Myelitis and Conversion Disorder. The patient was treated by acupuncture, moxibustion, herb medication(十全大補湯), electriccal stimulation theraphy, Bee Venom acupuncture, and had significant improvement in Wei symptom(?證). these results suggest the surface temperature differ remarkably from before being treated. The temperature is measured by using Digital Infrared Thermal Imaging(DITI). The results suggest that oriental medicare is an effective treatment for Wei symptom. We expected that therapeutic value of treatment of both leg Paralysis in the oriental medicine will be higher if more clinical studies and researches are accomplished.