• Title/Summary/Keyword: Sensor technology

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Structural and photoelectrical properties of copper phthalocyanine(CuPc) thin film on Si substrate by thermal evaporation (Si 기판위에 열증착법으로 제조한 copper phthalocyanine(CuPc) 박막의 구조 및 광전특성)

  • Lee, Hea-Yeon;Jeong, Jung-Hyun;Lee, Jong-Kyu
    • Journal of Sensor Science and Technology
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    • v.6 no.5
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    • pp.407-413
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    • 1997
  • The crystallized CuPc(copper phthalocyanine) film on a p-type <100> Si substrate is prepared at the substrate temperature of $300^{\circ}C$ by thermal evaporation. X -ray diffraction analysis showed the CuPc film to have a-axis oriented structure. For the measurement of photovoltaic characteristics of the CuPc/Si film and the Si substrate, a transverse current-voltage (I-V) curve is observed. In the dark, the Au/Si junction is shown to be ohmic contact. However, under illumination, a photovoltaic effect is not observed. The I-V curve in the dark indicates that the CuPc film on Si may form an ohmic contact. Since the CuPc film is a p-type semiconductor, the CuPc/p-Si junction has no barrier at the interface. Under illumination, the CuPc/Si junction shows a large photocurrent comparing with that of the wafer. The result indicates that the CuPc layer plays an important role in the photocarrier generation under red illumination (600 nm). The CuPc/Si film shows the photo voltaic characteristics with a short-circuit photocurrent ($J_{sc}$) of $4.29\;mA/cm^{2}$ and an open-circuit voltage ($V_{oc}$) of 12 mA.

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Characteristics and Application of PLT Thin-Films Deposited on ITO Substrate (ITO 기판위에 증착시킨 PLT 박막의 특성 및 그 응용)

  • Bae, Seung-Choon;Park, Sung-Kun;Choi, Byung-Jin;Kim, Ki-Wan
    • Journal of Sensor Science and Technology
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    • v.6 no.5
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    • pp.423-429
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    • 1997
  • We fabricated PLT thin films on ITO substrate for flat pannel display and investigated the characteristics, then we applicated to electroluminescent device and investigated application possibility. When we fabricated PLT thin films with substrate temperature of $500^{\circ}C$, and pressure of 30 mTorr, the relative deielectric constant and breakdown electricfield of PLT thin films were 120 and 3.2MV/cm. The electric resistivity was $2.0{\times}10^{12}{\Omega}{\cdot}cm$. PLT thin films had polycrystal structure of perovskite and pyrochlore at the higher substrate temperature than $450^{\circ}C$, and had good crystallinity at higher pressure. To use PLT insulator film and ZnS:Mn phosphor, we fabricated thin film electroluminescent device of ITO/PLT/ZnS:Mn/PLT/Al structure. At the result, threshold voltage was $35.2V_{rms}$ and brightness was $2400cd/m^{2}$ at $50V_{rms}$ and 1kHz. Maximum luminescence efficiency was 0.811m/W.

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Fabrication and Electrical Properties of High Tc $A_{2}B_{2}O_{7}$ Piezoelectric Ceramics Using the Powders Prepared by the Molten Salt Synthesis Method (용융염합성법에 의한 $A_{2}B_{2}O_{7}$ 고온압전세라믹스의 제작과 전기적특성)

  • Park, In-Ho;Kim, Tae-Gyu;Nam, Hyo-Duk
    • Journal of Sensor Science and Technology
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    • v.5 no.3
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    • pp.93-100
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    • 1996
  • Polycrystalline $Sr_{2}(Ta_{1-x}Nbx)_{2}O_{7}$ and $La_{2}Ti_{2}O_{7}$ ceramics having very high Curie temperatures were synthesized by the conventional oxide mixing method (CON) and the molten salt synthesis method (MSS). Physical characteristics and phase relationship of calcined powders, as well as the sintering behavior, the grain-orientation and dielectric properties of sintered ceramics were investigated as a function of composition and firing temperature. The single $A_{2}B_{2}O_{7}$ phase was synthesized by using the MSS method at 100 - $150^{\circ}C$ lower temperature compared to the CON method. As Nb content increased in $Sr_{2}(Ta_{1-x}Nbx)_{2}O_{7}$ ceramics, the Curie temperature and the dielectric constant at Curie temperature were raised, and the sintering behavior and the degree of grain-orientation were also improved at the same time. The use of MSS-derived powders made it possible to lower the sintering temperature and to improve the dielectric properties of the sintering samples. However, the piezoelectric properties as well as the grain-orientation were not improved any further by the MSS route.

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Electrical characteristics of Au and Pt diffused silicon $p^{+}-n$ Junction diode (Au와 Pt 확산에 의한 실리콘 $p^{+}-n$ 접합 스위칭다이오드의 전기적 특성)

  • Chung, Kee-Bock;Lee, Jae-Gon;Choi, Sie-Young
    • Journal of Sensor Science and Technology
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    • v.5 no.3
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    • pp.101-108
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    • 1996
  • The silicon $p^{+}-n$ junction diodes were fabricated. The fabricated wafers were treated by single or double annealing steps. Single annealing process was performed by diffusion of either Au or Pt into the wafer under the oxygen or nitrogen ambient at $800{\sim}1010^{\circ}C$. Second annealing step involved additional annealing of the single annealed wafer under the oxygen ambient at $800{\sim}1010^{\circ}C$ for one hour. Electrical characteristics of the diodes were investigated to evaluate the effect of the annealing treatments. In the case of single annealing under nitrogen ambient at $1010^{\circ}C$ for one hour, the amount of leakage current of Pt diffused diode was 75 times larger than that of Au diffused one. The optimum processing condition to achieve high speed silicon $p^{+}-n$ junction diodes from this study was obtained when Pt diffused wafer(treated under the nitrogen ambient at $1010^{\circ}C$ for one hour) was secondly annealed in an oxygen ambient at $800^{\circ}C$ for one hour. The resulting leakage current of two step annealed diodes were remarkably reduced to 1/1100 of the single annealed one. The diode characteristics such as recovery time, breakdown voltage, leakage current, and forward voltage were 4ns, 138V, 1.72nA, and 1V, respectively.

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Study on frequency response of implantable microphone and vibrating transducer for the gain compensation of implantable middle ear hearing aid (이식형 마이크로폰과 진동체를 갖는 인공중이의 이득 보상을 위한 주파수 특성 고찰)

  • Jung, Eui-Sung;Seong, Ki-Woong;Lim, Hyung-Gyu;Lee, Jang-Woo;Kim, Dong-Wook;Lee, Jyung-Hyun;Kim, Myoung-Nam;Cho, Jin-Ho
    • Journal of Sensor Science and Technology
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    • v.19 no.5
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    • pp.361-368
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    • 2010
  • ACROSS device, which is composed of an implantable microphone, a signal processor, and a vibrating transducer, is a fullyimplantable middle ear hearing device(F-IMEHD) for the recovery of patients with hearing loss. And since a microphone is implanted under skin and tissue at the temporal bones, the amplitude of the sound wave is attenuated by absorption and scattering. And the vibrating transducer attached to the ossicular chain caused also the different displacement from characteristic of the stapes. For the gain control of auditory signals, most of implantable hearing devices with the digital audio signal processor still apply to fitting rules of conventional hearing aid without regard to the effect of the implanted microphone and the vibrating transducer. So it should be taken into account the effect of the implantable microphone and the vibrating transducer to use the conventional audio fitting rule. The aim of this study was to measure gain characteristics caused by the implanted microphone and the vibrating transducer attached to the ossicle chains for the gain compensation of ACROSS device. Differential floating mass transducers (DFMT) of ACROSS device were clipped on four cadaver temporal bones. And after placing the DFMT on them, displacements of the ossicle chain with the DFMT operated by 1 $mA_{peak}$ current was measured using laser Doppler vibrometer. And the sensitivity of microphones under the sampled pig skin and the skin of 3 rat back were measured by stimulus of pure tones in frequency from 0.1 to 8.9 kHz. And we confirmed that the microphone implanted under skin showed poorer frequency response in the acoustic high-frequency band than it in the low- to mid- frequency band, and the resonant frequency of the stapes vibration was changed by attaching the DFMT on the incus, the displacement of the DFMT driven with 1 $mA_{rms}$ was higher by the amount of about 20 dB than that of cadaver's stapes driven by the sound presssure of 94 dB SPL in resonance frequency range.

A Study on u-CCTV Fire Prevention System Development of System and Fire Judgement (u-CCTV 화재 감시 시스템 개발을 위한 시스템 및 화재 판별 기술 연구)

  • Kim, Young-Hyuk;Lim, Il-Kwon;Li, Qigui;Park, So-A;Kim, Myung-Jin;Lee, Jae-Kwang
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2010.05a
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    • pp.463-466
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    • 2010
  • In this paper, CCTV based fire surveillance system should aim to development. Advantages and Disadvantages analyzed of Existing sensor-based fire surveillance system and video-based fire surveillance system. To national support U-City, U-Home, U-Campus, etc, spread the ubiquitous environment appropriate to fire surveillance system model and a fire judgement technology. For this study, Microsoft LifeCam VX-1000 using through the capturing images and analyzed for apple and tomato, Finally we used H.264. The client uses the Linux OS with ARM9 S3C2440 board was manufactured, the client's role is passed to the server to processed capturing image. Client and the server is basically a 1:1 video communications. So to multiple receive to video multicast support will be a specification. Is fire surveillance system designed for multiple video communication. Video data from the RGB format to YUV format and transfer and fire detection for Y value. Y value is know movement data. The red color of the fire is determined to detect and calculate the value of Y at the fire continues to detect the movement of flame.

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The Trends and Application Prospects of Medical Information System on the Ubiquitous Environments (유비쿼터스 환경에서의 의료정보시스템 동향 및 응용의 전망)

  • Kim, Chang-Soo;Kim, Hwa-Gon
    • Journal of radiological science and technology
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    • v.28 no.3
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    • pp.193-201
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    • 2005
  • We are living in Ubiquitous society now. There is also trend of integration in medical field that is largely affected by outside environment. At this time, it is necessary to rightly understand the abstract, function, expected effect and management method of Integration Medical Information System(IMIS) to use this system effectively for solving many hospital information system problems and disadvantages. It is fact that large-sized hospitals are improving the quality of service for treatment of patients through building integrated Medical Information System. So it is necessary to change this individual system that is previously developed and used for treatment assistance, hospital affair or general management respectively to integrated management system, modify patient information or treatment information data to the data suitable for new system and build the integrated medical information system suitable for the hospital service with treatment data and integrated medical information. This paper suggested and designed abstract of integrated medical information system, the organization of system, the character of system and the plan and materialization of IMIS when building integrated medical information system. And the context of this paper is suggested trend of industry and solution of integration EMR, HIS, PACS. Therefore this paper is suggested development strategy, implemented integration medical information system.

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A Study on Technique for Image Quality Enhancement to Maximize Container Inspection Efficiency (컨테이너 검사 효율 극대화를 위한 화질 향상 기법 연구)

  • Lee, Chang-Ho;Shin, Ji-Hye;Kim, Jang-Oh;Jung, Young-Jin;Min, Byung-In
    • Journal of radiological science and technology
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    • v.40 no.4
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    • pp.639-646
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    • 2017
  • The purpose of this study is to present the algorithm to minimize the image noise caused by deterioration of high X-ray container inspection equipment and the faulty detection sensors, and to improvement quality of the container inspection images using MATLAB Toolbox. The daily checking images for the container inspection were used with the subject images and the noise caused by the horizontal and vertical images was evaluated with Root Mean Square (RMS) method, which is the most basic evaluation method of digital radiation image. Also, quality of the improved images was evaluated compared to quality of the orignal images. As a result, all RMS value of the improved images was lower then the original images by a mean of 13.5% in the horizontal images and 18.2% in the vertical images respectively. Also so did RMS value of the improved container images, by a mean of 13.4% in the horizontal images and 19.1% in the vertical images respectively. These findings can be verified objectively and visually and they would help the reading process of the container images be effective in Korea Customs Service.

Control of Daily First Drainage Time by Irrigation Management with Drainage Level Sensor in Tomato Perlite Bag Culture (배액전극제어법에 의한 토마토 펄라이트 자루재배시 일중 첫 배액 제어)

  • Kim, Sung-Eun;Sim, Sang-Youn;Kim, Young-Shik
    • Horticultural Science & Technology
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    • v.28 no.3
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    • pp.409-414
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    • 2010
  • The first drainage time in a day was controlled for precise irrigation management with low consumption of nutrient solution in tomato perlite bag culture system by measuring water level of drained water in drainage catchment part. This method automatically adjusted the irrigation time under any condition of light, temperature and humidity, resulting in stable water content in substrates. However, it was difficult to keep the time consistent as they were set. It drained with the deviation of 20 min in the treatment in which the first drainage time was set at 10:00 and 50 min in the treatment set at 10:30. The first drainage time was not constant, but the drain occurred stably before noon in the treatment of which irrigation frequency was longer than 30 min. The drainage ratio was better balanced in all the treatments using drainage level sensors than the treatment using time clock for irrigation control. High water and fertilizer efficiencies were obtained. Although the growth, total yield and sugar content were not significantly different between the treatments, fruit weight was higher in the treatments using drainage level sensors than that using timer.

A Study on the Method for Three-dimensional Geo-positioning Using Heterogeneous Satellite Stereo Images (이종위성 스테레오 영상의 3차원 위치 결정 방법 연구)

  • Jaehoon, Jeong
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.33 no.4
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    • pp.325-331
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    • 2015
  • This paper suggests an intersection method to improve the accuracy of three-dimensional position from heterogeneous satellite stereo images, and addresses validation of the suggested method following the experimental results. The three-dimensional position is achieved by determining an intersection point of two rays that have been precisely adjusted through the sensor orientation. In case of conventional homogeneous satellite stereo images, the intersection point is generally determined as a mid-point of the shortest line that links two rays in at least square fashion. In this paper, a refined method, which determines the intersection point upon the ray adjusted at the higher resolution image, was used to improve the positioning accuracy of heterogeneous satellite images. Those heterogeneous satellite stereo pairs were constituted using two KOMPSAT-2 and QuickBird images of covering the same area. Also, the positioning results were visually compared in between the conventional intersection and the refined intersection, while the quantitative analysis was performed. The results demonstrated that the potential of refined intersection improved the positioning accuracy of heterogeneous satellite stereo pairs; especially, with a weak geometry of the heterogeneous satellite stereo, the greater effects on the accuracy improvement.