• Title/Summary/Keyword: Threshold temperature

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A Low-Power Current-Mode CMOS Voltage Reference Circuit (저전력 전류모드 CMOS 기준전압 발생 회로)

  • 권덕기;오원석
    • Proceedings of the IEEK Conference
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    • 1998.10a
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    • pp.1077-1080
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    • 1998
  • In this paper, a simple low-power current-mode CMOS wotage reference circuit is proposed. The reference circuit of enhancement-mode MOS transistors and resistors. Temperature compensation is made by adding a current component proportional to a thermal voltage to a current component proportional to a threshold voltage. The designed circuit has been simulated using a $0.65\mu\textrm{m}$ n-well CMOS process parameters. The simulation results show that the reference circuit has a temperature coefficient less than $7.8ppm/^{\circ}C$ and a power-supply(VDD) coefficient less than 0.079%/V for a temperature range from $-30^{\circ}C$ to $130^{\circ}C$ and a VDD range from 4.0V to 12V. The power consumption is 105㎼ for VDD=5V and $T=30^{\circ}C.$ The proposed reference circuit can be designed to generate a wide range of reference voltages owing to its current-mode operation.

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The Mechanism of Thermoregulatory Action of Capsaicin Is Different from That of Its Antinociceptive Effect in Guinea Pig

  • Yi-Sook JUNG;Tai-Soon CHO;Shin, Hwa-Sup
    • Biomolecules & Therapeutics
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    • v.5 no.2
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    • pp.211-214
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    • 1997
  • In the present study, we investigated the mechanisms of antinociceptive effect and thermoregulatory action of capsaicin in guinea pigs. The administration of capsaicin (5 mg/kg, s.c.) caused a significant decrease in frequency of eye wiping, an indicative of nociceptive threshold. This antinociceptive effect of calsaicin was abolished by co-administration of capsazepine (30 mg/kg, s.c.) with capsaicin, suggesting the involvement of a vanilloid receptor in the antinociceptive action of capsaicin. The administration of capsaicin (1 mg/kg, s.c.) produced a significant decrease in body temperature of guinea pigs. The maximum decrease in body temperature by 2 degrees was shown 1 hour after the treatment, and this decrease was not reversed by coadministration of capsazepine. In conclusion, it is suggested that the mechanism of action of capsaicin-induced thermoregulation involves different pathways from that of capsaicin-induced antinociception.

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Fabrication and Temperature Variation Characteristics of Hydrogenerated Amorphous Silicon Thin Film Transistor (비정질 실리콘 박막 트랜지터(a-si : H TFT)의 제작과 온도변화 특성)

  • 이우선;강용철;박영준;차인수
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.41 no.2
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    • pp.163-169
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    • 1992
  • A new analytical expression for the temperature variation characteristics of hydrogenerated amorphous silicon thin film transistors(a-si:H TFT), between 223K and 433K, is presented and experimentally verified. The results show that the experimental transfer and output characteristics at several temperatures are easily modeled between -5$0^{\circ}C$ and 9$0^{\circ}C$. The model is based on three functions obtained from the experimental data of IS1DT versus VS1GT. Theoretical results confirm the simple form of the model in terms of the device geometry. It was determined that as the temperature increased, the saturated drain current increased and, at a fixed gate voltage, the device saturated at increasingly larger drain voltages while the threshold voltages decreased.

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Fabrication of 1.55.mu.m RWG DFB lasers (1.55.mu.m RWG-DFB 레이저 제작에 관한 연구)

  • 김중연;강명구;전현성;오환술
    • Proceedings of the IEEK Conference
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    • 1998.06a
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    • pp.469-472
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    • 1998
  • InGaAsP/InP ridge waveguide(RWG) distributed feedback(DFB) lasers (LD) operating at 1.55.mu.m were fabricated by a two step MOCVD process. The CW laser threshold and the slope efficiency from these lasers are 22.5mA and 0.127mW/MA perfacet at room temperature. Single longitudinal mode operation with side mode suppression of more than 30dB is obtained at 5mW. The temperature sensitivity and characteristic temperature (T$_{0}$) from DFB lasers were obtained 1.0.angs./.deg. C and 50.3K between 20.deg. C and 70.deg. C, respectively.y.

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Analysis of MICC, ELA TFT performance transition according to substrate temperature and gate bias stress time variation (온도 변화 및 Gate bias stress time에 따른 MICC, ELA TFT성능 변화 비교 분석)

  • Yi, Seung-Ho;Lee, Won-Baek;Yi, Jun-Sin
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2010.06a
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    • pp.368-368
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    • 2010
  • Using TFTs crystallized by MICC and ELA, electron mobility and threshold voltage were measured according to various substrate temperature from $-40^{\circ}C$ to $100^{\circ}C$. Basic curve, $V_G-I_D$, is also measured under various stress time from 1s to 10000s. Consequently, due to the passivation effect and number of grains, mobility of MICC is varied in the range of -8% ~ 7.6%, while that of ELA is varied from -11.04% ~ 13.25%. Also, since $V_G-I_D$ curve is dominantly affected by grain size, active layer interface, the graph remained steady under the various gate bias stress time from 1s to 10000s. This proves the point that MICC can be alternative technic to ELA.

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A Study on the Reliability of TRENCH GATE POWER MOSFET (TRENCH GATE POWER MOSFET의 신뢰성 분석 연구)

  • Hwang, Joon-Sun;Koo, Yong-Seo;Kim, Sang-Ki;An, Chul
    • Proceedings of the IEEK Conference
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    • 2003.07b
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    • pp.683-686
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    • 2003
  • In this paper, we have investigated electrical characteristics of TRENCH GATE POWER MOSFET in the temperature range of 300K to 500K. The results of this study indicate that on-resistance and breakdown voltage increase with the temperature ,but drain current, threshold voltage and transconductance decrease with the temperature. Especially, it is observed that electrical characteristics are improved as numerical unit cells are increased.

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Measurement of the Anticlinic Coupling Coefficient of an Antiferroelectric Liquid Crystal

  • Kang, Dae-Seung;Kimura, Munehiro
    • 한국정보디스플레이학회:학술대회논문집
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    • 2002.08a
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    • pp.487-490
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    • 2002
  • In this paper, we report a novel way to evaluate the anticlinic interlayer coupling coefficient U between smectic layers of an antiferroelectric liquid crystal, by utilizing a small field-induced perturbation of the molecular orientation. U was found to exhibit an unusual "S-shaped" dependence on temperature, with values ranging between $0.4{\times}10^4$ and $0.4{\times}10^{-1}$ erg $cm^{-3}$ over a 10$^{\circ}C$ temperature range below smectic A-smectic $C_A$ phase transition temperature. The results are good agreement with estimates for U based upon the threshold field for the onset of solitary waves, and provide strong supporting the low-field regime for the single Fourier component model.

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Fabrication of 1.55.$\mu\textrm{m}$ RWG-DFB-LDs and evaluation of its optical characteristics (1.55$\mu\textrm{m}$ RWG-DFB-LD 제작 및 광학 특성 평가)

  • 이중기;이승원;조호성;장동훈;박경현;김정수;황인덕;김홍만;박형무
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.32A no.2
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    • pp.73-80
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    • 1995
  • We fabricated the 1.55.mu.m RWG-DFB-LD and measured its electrical and optical characteristics. Interference fringe of optical beams was used for grating formation and epi layers were grown by lower-temperature LPE. The fabricated RWG-DFB-LD operated in a single longitudinal mode with more than 30dB SMSR at 1543nm emitting wavelength and its threshold current was 40mA. The wavelength shift with operating temperature and characteristic temperature T$_{o}$ were 0.9${\AA}/^{\circ}C$ and 59K, respectively. Linewidth enhancement factor .alpha. and linewidty.optical power product were estimated as 6.15 and 60MHz$\cdot$mW respectively.

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Fiber-Optic Distributed Overheating Detection Sensor Using an Optical Time Domain Refrectometry (광시간영역 반사계를 이용한 분포형 광섬유 과열 감지 센서)

  • Kim, Dae Hyun;Kim, Kwang Taek
    • Journal of Sensor Science and Technology
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    • v.22 no.4
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    • pp.297-301
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    • 2013
  • We proposed and demonstrated a distributed fiber-optic overheating detection sensor using optical time domain refrectometry. With increased of temperature the optical fiber is bended by a bi-metal and it result in optical leaky loss of the fiber. The sensor structure is designed in such a way that the signal of overheating is happen when the temperature exceeding a threshold temperature and the optical fiber is protected from excess bending.

Gas Effect at High Temperature on the Supersonic Nozzle Conception

  • Boun-jad, Mohamed;Zebbiche, Toufik;Allali, Abderrazak
    • International Journal of Aeronautical and Space Sciences
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    • v.18 no.1
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    • pp.82-90
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    • 2017
  • The aim of this work is to develop a new computational program to determine the effect of using the gas of propulsion of combustion chamber at high temperature on the shape of the two-dimensional Minimum Length Nozzle giving a uniform and parallel flow at the exit section using the method of characteristics. The selected gases are $H_2$, $O_2$, $N_2$, CO, $CO_2$, $H_2O$, $NH_3$, $CH_4$ and air. All design parameters depend on the stagnation temperature, the exit Mach number and the used gas. The specific heat at constant pressure varies with the temperature and the selected gas. The gas is still considered as perfect. It is calorically imperfect and thermally perfect below the threshold of dissociation of molecules. A error calculation between the parameters of different gases with air is done in this case for purposes of comparison. Endless forms of nozzles may be found based on the choise of $T_0$, $M_E$ and the selected gas. For nozzles delivering same exit Mach number with the same stagnation temperature, we can choose the right gas for aerospace manufacturing rockets, missiles and supersonic aircraft and for supersonic blowers as needed in settings conception.