• 제목/요약/키워드: Heat detection

검색결과 440건 처리시간 0.026초

A Mueller Matrix Study for Measuring Thermal Damage Levels of Collagenous Tissues

  • Jun, Jae-Hoon
    • 대한의용생체공학회:의공학회지
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    • 제27권6호
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    • pp.310-317
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    • 2006
  • Extensive research with polarimetry and Mueller matrix has been done for chemical measurements and possible cancer detection. However, the effect of thermally denatured biological tissue on polarization changes is not well known. The purpose of this study is to characterize polarization changes in collagen due to thermal denaturation. The variations in polarized state caused by thermal damage were investigated by obtaining the Mueller matrix elements of collagen sample at multiple thermal damage levels. The changes in birefringence of denatured collagen were also investigated. This information could be used to determine the extent of thermal damage level of clinically heat treated tissues.

Landsat TM과 $ETM^+$ 영상자료를 활용한 도시지역의 토지피복과 도시열섬의 변화 검출 (Change Detection of Land Cover and Urban Heat Island from Landsat TM and $ETM^+$)

  • 이진덕;최용진;박진성
    • 한국GIS학회:학술대회논문집
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    • 한국GIS학회 2006년도 GIS/RS 공동춘계학술대회
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    • pp.169-174
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    • 2006
  • 도시지역의 급변하는 토지이용의 패턴 및 토지피복상태 등의 도시환경의 변화를 분석하는 것은 도시계획 및 개발계획을 기획, 입안하는데 중요한 자료로 활용될 수 있을 것이다. 본 연구에서는 구미시를 대상지역으로 하는 Landsat TM과 Landsat $ETM^+$ 인공위성 영상데이터로부터 토지피복/토지이용 분류를 수행함으로써 18년간의 광역적 도시변화를 탐지하였다. 또한 도시의 발전과 지표면 온도의 상관성을 알아보기 위하여 열적외선 파장영역을 이용하여 온도를 추출하였다. 시가지 확장으로 인한 지표면 온도의 상승을 확인하고 이를 통해 토지이용/토지피복의 상관관계 분석 및 식생지수분포를 비교하였다.

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바이메탈형 적외선 이미지 센서 제작과 칸틸레버 변위에 관한 고찰 (A study on MicroCantilever Deflection for the Infrared Image Sensor using Bimetal Structure)

  • 강정호
    • 한국기계가공학회지
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    • 제4권4호
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    • pp.34-38
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    • 2005
  • This is a widespread requirement for low cost lightweight thermal imaging sensors for both military and civilian applications. Today, a large number of uncooled infrared detector developments are under progress due to the availability of silicon technology that enables realization of low cost IR sensor. System prices are continuing to drop, and swelling production volume will soon drive process substantially lower. The feasibility of micromechanical optical and infrared (IR) detection using microcantilevers is demonstrated. Microcantilevers provide a simple Structurefor developing single- and multi-element sensors for visible and infrared radiation that are smaller, more sensitive and lower in cost than quantum or thermal detectors. Microcantilevers coated with a heat absorbing layer undergo bending due to the differential stress originating from the bimetallic effect. This paper reports a micromachined silicon uncooled thermal imager intended for applications in automated process control. This paper presents the design, fabrication, and the behavior of cantilever for thermomechanical sensing.

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Magnetic and Thermal Evaluation of a Magnetic Tunneling Junction Current Sensor Package

  • Rhod, Eduardo;Peter, Celso;Hasenkamp, Willyan;Grion, Agner
    • 마이크로전자및패키징학회지
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    • 제23권4호
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    • pp.49-55
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    • 2016
  • Nowadays there are magnetic sensors in a wide variety of equipment such as computers, cars, airplanes, medical and industrial instruments. In many of these applications the magnetic sensors offer safe and non-invasive means of detection and are more reliable than other technologies. The electric current in a conductor generates a magnetic field detected by this type of sensor. This work aims to define a package dedicated to an electrical current sensor using a MTJ (Magnetic Tunnel Junction) as a sensing device. Four different proposals of packaging, three variations of the chip on board (CoB) package type and one variation of the thin small outline package (TSOP) were analyzed by COMSOL modeling software by simulating a brad range of current injection. The results obtained from the thermal and magnetic analysis has proven to be very important for package improvements, specially for heat dissipation performance.

A Model-Based Fault Detection and Diagnosis Methodology for Cooling Tower

  • Ahn, Byung-Cheon
    • International Journal of Air-Conditioning and Refrigeration
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    • 제9권3호
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    • pp.63-71
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    • 2001
  • This paper presents a model-based method for detecting and diagnosing some faults in the cooling tower of healing, ventilating, and air-conditioning systems. A simple model for the cooling tower is employed. Faults in cooling tower operation are detected through the deviations in the values of system characteristic parameters such as the heat transfer coefficient-area product, the tower approach, the tower effectiveness, and fan power. Three distinct faults are considered: cooling tower inlet water temperature sensor fault, cooling tower pump fault, and cooling tower fan fault. As a result, most values of the system characteristics parameter variations due to a fault are much higher or lower than the values without faults. This allows the faults in a cooling tower to be detected easily using above methods. The diagnostic rules for the faults were also developed through investigating the changes in the different parameter due to each faults.

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Fuzzy Clustering 기법을 이용한 Multi-Evaporator Vapor Compression Cycle의 적정 냉매량 판정에 관한 연구 (Studies on Correct Refrigerant Amount Detection for Multi-Evaporative Vapor Compression Cycle using Fuzzy Clustering)

  • 김성환;최창민;권기백;정백영
    • 대한설비공학회:학술대회논문집
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    • 대한설비공학회 2009년도 하계학술발표대회 논문집
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    • pp.459-464
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    • 2009
  • This study has been conducted on how to determine the multi-evaporator vapor compression cycle system is charged correctly by using sensor readings which are used to control system. In this paper, the characteristics of the multi-evaporator were presented and sensor values were classified using fuzzy clustering. finally classification logic and it's performance were discussed by applying commercial VRF system.

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말에서 체열촬영술의 응용 (Use of thermography in Thoroughbred horses)

  • 양영진;조길재;남치주;최석화
    • 대한수의학회지
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    • 제42권2호
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    • pp.269-275
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    • 2002
  • The aim of this study was to investigate the usefulness and effectiveness of thermography in horse. Total 21 horses associated with locomotors, wound, and ophthalmic disease were investigated. Thermographically, the wannest area in normal limb was coronary band ($27.26^{\circ}C$), and carpus, metacarpus, fetlock, and pastern area were $26.64^{\circ}C$, $24.42^{\circ}C$, $23.64^{\circ}C$ and $23.06^{\circ}C$, respectively. The temperature($^{\circ}C$) of horses with lameness, swelling, nervous, ataxia was lower(cold spot) than surrounding tissue or symmetry area, and with heat, signs of inflammation was increased(hot spot). These results suggest that the thermography is useful for the early detection of locomotors, wound, and ophthalmic disease in horse and an excellent adjunct to clinical examination.

Comparative Study of Linear and Nonlinear Ultrasonic Techniques for Evaluation Thermal Damage of Tube-Like Structures

  • Li, Weibin;Cho, Younho;Li, Xianqiang
    • 비파괴검사학회지
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    • 제33권1호
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    • pp.1-6
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    • 2013
  • Ultrasonic guided wave techniques have been widely used for long range nondestructive detection in tube-like structures. The present paper investigates the ultrasonic linear and nonlinear parameters for evaluating the thermal damage in aluminum pipe. Specimens were subjected to thermal loading. Flexible polyvinylidene fluoride (PVDF) comb transducers were used to generate and receive the ultrasonic waves. The second harmonic wave generation technique was used to check the material nonlinearity change after different heat loadings. The conventional linear ultrasonic approach based on attenuation was also used to evaluate the thermal damages in specimens. The results show that the proposed experimental setup is viable to assess the thermal damage in an aluminum pipe. The ultrasonic nonlinear parameter is a promising candidate for the prediction of micro-damages in a tube-like structure.

산화물 세라믹 재료 기반 자외선 센서 (Ultra Violet (UV) Sensor based on Oxide Ceramic Materials)

  • 류학기
    • 세라미스트
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    • 제22권1호
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    • pp.27-35
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    • 2019
  • Research on ultraviolet (UV) light detection has attracted considerable attention from scientific researchers in related fields. It can be said that it is a very important time to accurately monitor the UV irradiation amount according to the wavelength region in real time. The oxide is very diverse in its kind and has the advantage of being able to efficiently control the band gap through band gap engineering. In addition, it is very stable in response to heat and atmospheric oxygen when UV is absorbed. Also, there is a known method that can effectively manufacture oxide nanoparticles and nanorods through various synthesis methods, and researches for improving the sensitivity of UV sensors have been carried out using this method. In this paper, we introduce the materials that can be used as UV sensors among various wide band oxide materials, and review the results of researches of various UV sensors using nano materials.

몰드형 계기용 변압기의 소손원인 해석에 관한 연구 (A Study on the Deteriorated Cause Analysis of Mold Type Potential Transformer)

  • 최충석;김혁수;송길목;김형래;이덕출
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2000년도 하계학술대회 논문집 C
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    • pp.1557-1559
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    • 2000
  • In this paper, we intend to establish the judgement of electrical fire through analysis of PT(Potential Transformer) using the power installation. The columnar structure and the void generated by abrupt heat grew at the tenter of boundary-face on the metallurgical microscope analysis. The detection of OK lines was confirmed by EDX(Energy Dispersive X-ray spectroscopy) as melting and recombination due to the layer-short of the wiring. We found that the thermal-weight decrease occurred at 300$^{\circ}C$ in case of being the thermal-deterioration on the base of the result that analyzed the insulated-materials by using TGA, and the thermal reaction limited-value of PT insulator was about 300$^{\circ}C$ on the DSC curve. As this analysis, we confirmed what the layer-short appeared in the wiring of PT.

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