• 제목/요약/키워드: $K^+-channel$

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산화물 박막 트랜지스터 동작에 대한 접촉 저항의 영향 (Study on contact resistance on the performance of Oxide thin film transistors)

  • 이재상;장성필;구상모;이상렬
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2009년도 춘계학술대회 논문집
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    • pp.63-64
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    • 2009
  • The TFTs have been fabricated with 3 different geometry SID electrodes which have the same channel W/L ratio (W/L = 5) due to constant channel resistance, The 3 samples have different channel widths (350, 150, and $25\;{\mu}m$) and channel lengths (70, 30, and $5\;{\mu}m$) by fixed channel W/L ratio simultaneously on one chip for reliable comparisons. Resultant on-current and field effect mobility are proportional to the channel width, while the subthreshold swing is inversely proportional to the channel width mainly due to the change of contact resistance. These results show that the contact resistance strongly affects the device performances and should be considered in the applications.

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블라인드 채널추정기법(Blind Channel Identification)을 이용한 수중통신 연구 (Underwater Acoustic Communication Research using Blind Channel identification)

  • 김갑수;조아라;최영철;임용곤
    • 한국정보통신학회:학술대회논문집
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    • 한국해양정보통신학회 2007년도 추계종합학술대회
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    • pp.165-169
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    • 2007
  • Due to the complexity of underwater acoustic channel, signal estimation in underwater acoustic communication field is considerably affected from time-varying multipath fading channels. On this reason, the original signals should have many long training signals to estimate the channel and the purposed signals, and the bit rate of signals having information may have small rate. In order to avoid this loss of efficiency in underwater communication, this paper employed a blind channel identification method which don't use training signals. Simulations have predicted performance of the employed method in multipath environment and an aquatic plant experiment has verified the simulation results.

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Modulation of $Ca^{2+}-Activated$ Potassium Channels by cGMP-Dependent Signal Transduction Mechanism in Cerebral Arterial Smooth Muscle Cell of the Rabbit

  • Han, Jin;Kim, Na-Ri;Lee, Kwang-Bok;Kim, Eui-Yong
    • The Korean Journal of Physiology and Pharmacology
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    • 제4권6호
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    • pp.445-453
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    • 2000
  • The present investigation tested the hypothesis that the activation of protein kinase G (PKG) leads to a phosphorylation of $Ca^{2+}-activated$ potassium channel $(K_{Ca}\;channel)$ and is involved in the activation of $K_{Ca}$ channel activity in cerebral arterial smooth muscle cells of the rabbit. Single-channel currents were recorded in cell-attached and inside-out patch configurations of patch-clamp techniques. Both molsidomine derivative 3-morpholinosydnonimine-N-ethylcarbamide $(SIN-1,\;50\;{\mu}M)$ and 8-(4-Chlorophenylthio)-guanosine-3',5'-cyclic monophosphate $(8-pCPT-cGMP,\;100\;{\mu}M),$ a membrane-permeable analogue of cGMP, increased the $K_{Ca}$ channel activity in the cell-attached patch configuration, and the effect was removed upon washout of the drugs. In inside-out patches, single-channel current amplitude was not changed by SIN-1 and 8-pCPT-cGMP. Application of ATP $(100\;{\mu}M),$ cGMP $(100\;{\mu}M),$ ATP+cGMP $(100\;{\mu}M\;each),$ PKG $(5\;U/{\mu}l),$ ATP $(100\;{\mu}M)+PKG\;(5\;U/{\mu}l),$ or cGMP $(100\;{\mu}M)+PKG\;(5\;U/{\mu}l)$ did not increase the channel activity. ATP $(100\;{\mu}M)+cGMP\;(100\;{\mu}M)+PKG\;(5\;U/{\mu}l)$ added directly to the intracellular phase of inside-out patches increased the channel activity with no changes in the conductance. The heat-inactivated PKG had no effect on the channel activity, and the effect of PKG was inhibited by 8-(4-Chlorophenylthio)-guanosine-3',5'-cyclic monophosphate, Rp-isomer $(Rp-pCPT-cGMP,\;100\;{\mu}M),$ a potent inhibitor of PKG or protein phosphatase 2A (PP2A, 1 U/ml). In the presence of okadaic acid (OA, 5 nM), PP2A had no effect on the channel activity. The $K_{Ca}$ channel activity spontaneously decayed to the control level upon washout of ATP, cGMP and PKG, and this was prevented by OA (5 nM) in the medium. These results suggest that the PKG-mediated phosphorylations of $K_{Ca}$ channels, or some associated proteins in the membrane patch increase the activity of the $K_{Ca}$ channel, and the activation may be associated with the vasodilating action.

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삼음삼양(三陰三陽) 표리(表裏) 관계(關係)의 구성원리(構成原理)에 대한 연구(硏究) (A study of the exterior and interior relation's consitutional principle on three yin three yang)

  • 김준기;최달영
    • 대한한의학회지
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    • 제16권1호통권29호
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    • pp.437-450
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    • 1995
  • In order to clear the basic concept about oriental medical physiology and pathology, We studied the theory of three yin, three yang, and it is based on the principle that yang goes forward and yin goes back. The result were summarized as follows. 1. It showed how to originate about the concept of three yin three yang. 2. It showed the logical basis concerning that the TAIYANG channels are open, the YANGMING channels are shut, the SHAOYANG channels are pivots, the TAIYIN open, SHAOYIN shut, JUEYIN pivots. 3. According to the opening, closing, pivoting principle, It explained the exterior and interior relation such as TAIYANG and SHAOYIN, YANGMING and TAIYIN, SHAOYANG and JUEYIN. 4. According to the opening, closing, pivoting principle, It showed that arteries of the twelve channels rotated in lung channel of hand-TAIYIN, the large intestine channel of hand-YANGMING, the stomach channel of foot-YANGMING, the spleen channel of foot-TAIYIN, the heart channel of hand-SHAOYIN, the small intestine channel of hand-SHAOYANG, the urinary bladder channel of foot-TAIYANG, the kidney channel of foot-SHAOYIN, the pericardium channel of hand-JUEYIN, the sanjiao(三焦) channel of hand-SHAOYANG, the gall bladder channel of foot-SHAOYANG, the liver channel of foot-JUEYIN. 5. As arteries of the twelve channels was based on the cycle, the logical criticism about Napgibup(納氣法) was shown.

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THERMAL-HYDRAULIC CHARACTERISTICS FOR CANFLEX FUEL CHANNEL USING BURNABLE POISON IN CANDU REACTOR

  • BAE, JUN HO;JEONG, JONG YEOB
    • Nuclear Engineering and Technology
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    • 제47권5호
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    • pp.559-566
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    • 2015
  • The thermalehydraulic characteristics for the CANadian Deuterium Uranium Flexible (CANFLEX)-burnable poison (BP) fuel channel, which is loaded with a BP at the center ring based on the CANFLEX-RU (recycled uranium) fuel channel, are evaluated and compared with that of standard 37-element and CANFLEX-NU (natural uranium) fuel channels. The distributions of fuel temperature and critical channel power for the CANFLEX-BP fuel channel are calculated using the NUclear Heat Transport CIRcuit Thermohydraulics Analysis Code (NUCIRC) code for various creep rate and burnup. CANFLEX-BP fuel channel has been revealed to have a lower fuel temperature compared with that of a standard 37-element fuel channel, especially for high power channels. The critical channel power of CANFLEX-BP fuel channel has increased by about 10%, relative to that of a standard 37-element fuel channel for 380 channels in a core, and has higher value relative to that of the CANFLEX-NU fuel channel except the channels in the outer core. This study has shown that the use of a BP is feasible to enhance the thermal performance by the axial heat flux distribution, as well as the improvement of the reactor physical safety characteristics, and thus the reactor safety can be improved by the use of BP in a CANDU reactor.

A Unified Channel Thermal Noise Model for Short Channel MOS Transistors

  • Yu, Sang Dae
    • JSTS:Journal of Semiconductor Technology and Science
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    • 제13권3호
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    • pp.213-223
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    • 2013
  • A unified channel thermal noise model valid in all operation regions is presented for short channel MOS transistors. It is based on smooth interpolation between weak and strong inversion models and consistent physical model including velocity saturation, channel length modulation, and carrier heating. From testing for noise benchmark and comparing with published noise data, it is shown that the proposed noise model could be useful in simulating the MOSFET channel thermal noise in all operation regions.

Capacity-Equivocation Region of a Special Case of Wiretap Channel with Noiseless Feedback

  • Dai, Bin;Han Vinck, A.J.;Luo, Yuan;Ma, Zheng
    • Journal of Communications and Networks
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    • 제17권1호
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    • pp.21-26
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    • 2015
  • The general wiretap channel with noiseless feedback is first investigated by Ahlswede and Cai, where lower and upper bounds on the secrecy capacity are provided in their work. The upper bound is met with equality only in some special cases. In this paper, we study a special case of the general wiretap channel with noiseless feedback (called non-degraded wiretap channel with noiseless feedback). Inner and outer bounds on the capacity-equivocation region of this special model are provided. The outer bound is achievable if the main channel is more capable than the wiretap channel. The inner bound is constructed especially for the case that the wiretap channel is more capable than the main channel. The results of this paper are further explained via binary and Gaussian examples. Compared with the capacity results for the non-degraded wiretap channel, we find that the security is enhanced by using the noiseless feedback.

Two-way 증폭과 전송 릴레이 네트워크의 용량 최적화 (Capacity Optimization of Two-way Amplify-and Forward Relay Networks)

  • 모하마드 아부 하니프;이문호;박주용
    • 전자공학회논문지
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    • 제50권1호
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    • pp.27-33
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    • 2013
  • 본 논문에서는 two-way 릴레이 네트워크에서 파일롯(pilot)기반 채널 추정 기법과, 전송시 데이터 심볼과 함께 파일롯 심볼을 전송하는 기법을 제안한다. 채널상태정보(channel state information : CSI)가 없는 경우, destination은 파일롯 심볼을 사용해 채널을 추정한다. 이 시스템에서 릴레이는 파일롯 심볼과 데이터 심볼을 증폭하고 AF(amplify and forward)프로토콜을 사용하여 destination에 전송한다. 릴레이 이득이 고정되어 있어서 릴레이는 채널을 추정할 필요가 없기 때문에 destination이 채널을 추정한다. 이 채널 추정에는 이미 잘 알려진 LS(least-square)와 MMSE(minimum mean-square error)를 사용하였다.

MIMO-OFDM 시스템을 위한 가상 기준 신호를 이용한 채널 추정 기법 (Channel Estimation Using Virtual Pilot Signal for MIMO-OFDM Systems)

  • 서희진;박선호;김진홍;심병효
    • 한국전자파학회논문지
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    • 제27권1호
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    • pp.27-32
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    • 2016
  • 본 논문에서는 다중 입출력 안테나 OFDM 통신시스템에서 가상 기준 신호(virtual pilot signal)를 사용하는 한 연판정 지향 채널 추정 기법을 제안한다. 기준 신호만을 이용하여 채널을 추정하는 기존 방식과 달리 제안하는 기법은 기준 신호와 데이터를 동시에 사용하여 채널을 추정한다. 또한, 제안하는 기법에서 채널을 추정하기 위해 사용할 데이터를 선택하는 알고리즘을 제안한다. 모의실험을 통해 제안하는 기법이 기존 채널 추정에 비해 향상된 성능을 갖는 것을 확인할 수 있다.

국내 700 MHz 대역에서 MIMO 채널 측정 파라미터를 이용한 채널 상관도 분석 (Channel Correlation Analysis using MIMO Channel Measurement Parameters at Domestic 700MHz band)

  • 정명원;정영준;백정기
    • 한국인터넷방송통신학회논문지
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    • 제13권4호
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    • pp.1-7
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    • 2013
  • 차세대 이동통신 시스템에서는 새로운 주파수 대역에서 다중 안테나 사용이 높은 데이터 전송률과 용량을 가능하도록 만들 것이다. 본 논문에서는 국내 전파 특성 측정을 통해 도출된 채널 파라미터(경로 손실, 지연 확산, 각 확산, K-factor) 간에 상관도를 분석하였다. 측정은 DTV 방송과 혼신을 피하기 위하여 제주도에서 채널 사운더와 $4{\times}4$ 안테나로 측정하였다. 채널 파라미터 간에 상관도 분석은 유사한 환경에서 통신 시스템을 설계하는데 있어서 많은 도움을 줄 것이다.