• Title/Summary/Keyword: Microwave Sensor

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The Change of $NO_{2}$ Sensing Characteristics for Carbon Nanotubes with Growth and Post Treatment Conditions (탄소 나노튜브의 성장 및 후처리 조건에 따른 이산화질소 감지특성의 변화)

  • Lee, R.Y.
    • Journal of the Microelectronics and Packaging Society
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    • v.13 no.4
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    • pp.65-70
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    • 2006
  • Carbon nanotubes (CNT) grown by chemical vapor deposition (CVD) and plasma enhanced chemical vapor deposition (PECVD), and followed by annealing at $400{\sim}500^{\circ}C$ were investigated for gas sensing under 1.5ppm $NO_{2}$ concentration at an operating temperature of $200^{\circ}C$. The electrical resistance of CNT sensor decreased with temperature, indicating a semiconductor type. The resistance of CNT sensor decreased with $NO_{2}$ adsorption. It was found that the sensitivity of sensor was affected by humidity and decreased under microwave irradiation for 3 minutes. The CNT sensor grown by PECVD had a higher sensitivity than that of CVD.

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SAR Remote Sensing Technology Development and Application in China

  • Jing, Li
    • Proceedings of the KSRS Conference
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    • 2002.10a
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    • pp.448-453
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    • 2002
  • Remote sensing technology is one of the most powerful tools for human to know the nature and their living environment. However, before microwave remote sensing was developed and applied, remote sensing application was limited strongly by weather and time. Microwave remote sensing technology solves the problem. It makes us to have the capability to acquire information at all time of the day and under all weather condition, and make remote sensing technology be used in more wider area. Microwave remote sensing system include mainly Synthetic Aperture Radar (SAR), Microwave Radiometer, Microwave Scatterometer, and Altimeter (ALT). As SAR can acquire image whose spatial resolution is similar with visible and infrared image, it is paying much attention to and playing a more and more important role in earth observation. In recent year, the development of new SAR technology (multi-band and multi-polarization technology, InSAR technology, D-InSAR technology, and so on) makes SAR remote sensing go to an new stage, and its application area become more and more widely. The first Synthetic Aperture Radar (SAR) in the world appeared in 1960. After that, SAR and its application all developed very fast. Some radar satellites launched and run (include Seasat-A in 1978, ERS-1 in 1991, JERS-1 in 1992, Radarsat in 1995, and so on) promote SAR research and application in world greatly. China began to develop its SAR sensor and research SAR application in 1970s. After more than 30 years' research, it get some important development in sensor development data processing method, and application. Some operational systems have been used and play an important role. This paper will introduce the development of SAR technology and its application in China.

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Research Trend of Calibration Methods on the Satellite Microwave Sensors (지구관측용 마이크로파 위성센서의 검보정 연구 동향)

  • Jin, Kyoung-Wook;Yang, Koon-Ho
    • Current Industrial and Technological Trends in Aerospace
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    • v.8 no.1
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    • pp.33-44
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    • 2010
  • Research trend of calibration methods on the satellite microwave sensors was summarized in this paper. In addition, current operational or following near-future Earth observing satellite missions were introduced. According to these missions, the particular calibration methods on the corresponding microwave instruments were described. The main characteristics of the sensors and their scientific missions were also briefly explained.

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OMVPE and Plasma-Assisted Doping of ZnSe with Dimethlzinc:triethylamine Adduct Source

  • Huh, Jeung-Soo;Lim, Jeong-Ok
    • Journal of Sensor Science and Technology
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    • v.5 no.2
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    • pp.55-60
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    • 1996
  • The growth and microwave plasma assisted nitrogen doping of ZnSe by low pressure organometallic vapor phase epitaxy(OMVPE) has been investigated in a vertical downflow reactor equipped with a laser interferometer for in-situ growth rate measurements. Particular emphasis is placed on understanding growth characteristics of $H_{2}Se$ and the new adduct source dimethylzinc:triethyllamine($DMZn:NEt_{3}$) as compared with those obtained with $H_{2}Se$ and DMZn. At lower temperatures ($<300^{\circ}C$) and pressures(<30Torr), growth rates are higher with the adduct source and the surface morphology is improved relative to films synthesized with DMZn. Hall measurements and photoluminescence spectra of the grown films demonstrate that DMZn and $DMZn:NEt_{3}$ produce material with comparable electronic and optical properties. Microwave plasma decomposition of ammonia is investigated as a possible approach to increasing nitrogen incorporation in ZnSe and photoluminescence spectra are compared to those realized with conventional ammonia doping.

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SIMP: SLICKS AS INDICATORS FOR MARINE PROCESSES

  • Mitnik, Leonid M.;Gade, Martin;Ermakov, Stanislav A.;Lavrova, Olga Yu.;Silva, Jose B.C. da;Woolf, David K.
    • Proceedings of the KSRS Conference
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    • v.2
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    • pp.950-953
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    • 2006
  • SIMP is an international project funded by INTAS aimed at improving the information content, which can be inferred from multi-sensor satellite imagery of marine coastal areas. Scientific teams from Germany, UK, Portugal, and Russia focus on the development of novel tools for marine remote sensing of the coastal zone. In particular, the project teams' benefit from the fact that surface films may enhance the signatures of hydrodynamic processes such as plumes, internal waves, eddies, etc., on microwave, optical, and infrared imagery. The project's objectives are to develop a robust methodology for identifying slick-related phenomena/processes through their surface signatures and thereby, to improve the discrimination capabilities between slicks and other oceanic and atmospheric phenomena by taking into account information gained from satellite imagery quasi-simultaneously recorded at microwave, visible and IR wavelengths. The results of the two project years are summarized. Examples are given for the project’s web presentation, laboratory and field experiments, and of the analyses of various satellite data.

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Design and Implementation of a Microwave Motion Detector with Low Power Consumption

  • Sohn, Surg-Won
    • Journal of the Korea Society of Computer and Information
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    • v.20 no.7
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    • pp.57-64
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    • 2015
  • In this paper, we propose a design of microwave motion detector using X-band doppler radar sensor to minimize the power consumption. To minimize the power consumption and implement battery operated system, pulse input with 2 KHz, 4% duty cycle is exerted on the doppler radar sensor. In order to simplify the process of working with ATmega2560 microcontroller unit, Arduino compatible board is designed and implemented. Arduino is open source hardware and many library software is published as open source tools. Smartphone app is also proposed and designed as a real-time user interface of the motion detector. The SQLite database on the Android mobile operating system is used for recording raw data of motion detection for post-processing job, such as fast Fourier transform (FFT). Bluetooth interface module is implemented on the motion detection board as a wireless communication interface to the smartphone. The speed of human movement is identified by post-processing FFT.

The Fixation Effects of Biological specimen Using Microwave Oven Equipped With Infrared-Temperature Sensor (적외선 온도감응기를 장착한 마이크로파 오븐의 생체물질 고정효과)

  • 신길상
    • The Korean Journal of Zoology
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    • v.37 no.2
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    • pp.144-155
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    • 1994
  • 마이크로파 에너지로서 현미경 관찰을 위한 생체물질을 고정할 때, 고정효과는 화학 고정액을 사용할 때와 비교하여 보다 우수한 또는 적어도 동일한 고정효과를 볼 수 있다는 것은 알려진 사실이다. 그러나 기존의 마이크로파 오븐을 사용하여 생체물질을 고정하면 고정 정도에 일정성이 없는데, 이는 마이크로파가 균일하게 조사되지 않고 고정에 적절하도록 마이크로팍의 강도를 조절하기 어려우며, 이로 인하여 정확한 고정온도의 측정이 불가능하기 때문으로 생각된다. 이 연구에서는 마이크로파가 조사되는 동안 시료의 온도를 측정할 수 없는 기존의 마이크연.파 오븐의 단점을 보완하기 위하여 비접촉식 적외선 온도 감응기를 장착한 마이크로파 오븐을 개발하였으며 고정효과를 관찰하기 위하여는 포유류의 기준 조직으로 알려진 생쥐의 신장을 고정하였다 고정효과는 전체적인 구조와 세부 구조의 보존이 모두 우수하였고 최적의 고정온도는 28$\pm$1$^{\circ}C$(완충용액 20 ml, 10초) 이었다. 이와같이 고정된 재료는 고정효과 뿐만 아니라 염색성이 좋아서 조직화학 반응이 우수하고, 냉동절편법과 연계했을 때 전체 절편제작 과정이 2~4시간 내에 완료될 수 있었다 이때 절편의 질(질)은 화학 고정액이나 냉동절편 법에 의하여 제작된 것 보다 우수하였다.

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Fixation and Histochemistry of Biological Tissues Using the Microwave Fixator Equipped with Infrared-Temperature Sensor (적외선 온도감응기를 장착한 마이크로파 고정기에 의한 생체조직 고정효과와 조직화학적 특성)

  • 신길상;민소연;김완종;손태호
    • The Korean Journal of Zoology
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    • v.38 no.3
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    • pp.417-425
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    • 1995
  • The present study was carried out to investigate the effect of microwave fixation in comparison with that of chemical fixation in preparing the microscopic samples. The microwave fixator was equipped with infrared-temperature sensor, and that was designed to compensate air temperature in the microwave fixator. In the microwave fixation, rat tongue was well preserved in terms of muscular fasciculus and pancreas stained by Feulgen reagents showed clear reaction products in the nucleus. Reaction products by PAS method in duodenal villi appeared specifically at the goblet cells. In electron microscopy, pancreatic cellular components such as secretory granules and collagen bundles were well preserved in both fixations. In aspect of histochemical reaction and electron microscopy, high quality was due to the protein content of microwave fixed specimen. The microwave fixation method saved total duration engaging microscopic preparation.

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Fabrication and Characteristics of Multi-functional Sensor System (다기능 센서 시스템의 제작 및 동작 특성)

  • Jung, Jae-Eop;Lee, Hyo-Ung;Lee, Sung-Pil
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.11a
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    • pp.368-371
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    • 2003
  • The humidity sensors with a stable characteristics and gas sensors operating at room temperature have been fabricated, and a multi-functional sensor system which has gas sensor, humidity sensor, temperature sensor and control circuit has been applied to the microwave oven system. For a suitable cooking state, the humidity sensors was more applicable to heating and defrosting condition than gas sensors, however, the dynamic characteristics of gas sensors were obtained in the easy burning food such as pop corn.

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Synthesis and Property of Carbon Nanotube-Supported Pd and Pt Nanoparticles (탄소나노 튜브위에 성장된 Pd 및 Pt 나노 입자의 제조 및 특성)

  • Kim, Hyung-Kun;Lee, Rhim-Youl
    • Korean Journal of Materials Research
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    • v.19 no.4
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    • pp.192-197
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    • 2009
  • Carbon nanotubes (CNT) were used as a catalyst support where catalytically active Pd and Pt metal particles decorated the outside of the external CNT walls. In this study, Pd and Pt nanoparticles supported on $HNO_3$-treated CNT were prepared by microwave-assisted heating of the polyol process using $PdCl_2$ and $H_2PtCl_6{\codt}6H_2O$ precursors, respectively, and were then characterized by SEM, TEM, and Raman. Raman spectroscopy showed that the acid treated CNT had a higher intensity ratio of $I_D/I_G$ compared to that of non-treated CNT, indicating the formation of defects or functional groups on CNT after chemical oxidation. Microwave irradiation for total two minutes resulted in the formation of Pd and Pt nanoparticles on the acid treated CNT. The sizes of Pd and Pt nanoparticles were found to be less than 10 nm and 3 nm, respectively. Furthermore, the $SnO_2$ films doped with CNT decorated by Pd and Pt nanoparticles were prepared, and then the $NO_2$ gas response of these sensor films was evaluated under $1{\sim}5\;ppm$ $NO_2$ concentration at $200^{\circ}C$. It was found that the sensing property of the $SnO_2$ film sensor on $NO_2$ gas was greatly improved by the addition of CNT-supported Pd and Pt nanoparticles.