• Title/Summary/Keyword: Channel change

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A Study on the Ship Channel Design Method using Variable Bumper Area Model (I) (가변범퍼영역모델을 이용한 항로설계기법(I))

  • Jeong Dae-Deug;Lee Joong-Woo
    • Journal of Navigation and Port Research
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    • v.29 no.1 s.97
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    • pp.9-15
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    • 2005
  • To design ship channel is one of important factors for planning and developing a port. In most case, the core factors for designing ship channel are the layout and width of channel provided the net underkeel clearance is secured to be safe enough to pass. In this study, Variable Bumper Area(VBA) model is applied to design and assess ship channel. This model reflects ship's particular, ship domain theory, ship speed and mariner's ship handling skill and experience, especially external forces which cause leeway, set and drift and the change of ship maneuvering characteristics. A real time, full mission shiphandling simulator is used to analyze ship dynamic data according to mariner's ship control, external forces, ete. This model defines Domain degree and Domain-index for assessing the efficiency and safety of the channel. The proposed model is applied to Ulsan new port plan which has a channel width of 1.5 times the length of the largest vessel, a radius of 5 times the length of the largest vessel in a curve of 57 degree centerline angle and SBM facility adjacent to the lateral edge of channel. The result of this study shows that the width of the channel and radius of channel curve are suitable for the target ship but the difficulty of ship handling is caused by the large course change and SBM located in the vicinity of channel.

Properties of Single $K^{+}$ Channels of Skeletal Muscle Incorporated into Planar Lipid Bilayer

  • Park, Jin-Bong;Kim, Hee-Jeong;Cho, Myung-Haing;Lee, Hang;Park, Hong-Ki;Lee, Mun-Han;Ryu, Pan-Dong
    • The Korean Journal of Physiology
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    • v.29 no.1
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    • pp.13-27
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    • 1995
  • single $K^{+}$ channels of skeletal muscle from the rat and frog were into planar lipid bilayers and their properties were studied. Fusion was induced by an osmotic gradient. Of the four types of $K^{+}$ channels recorded, the two most frequently observed were a voltage and $Ca^{2+}-activated$ $K^{+}$ channel and a $K^{+}$ channel with a prominent conductance substate. The first $K^{+}$ channel was identified as the large $Ca^{2+}-activated$ $K^{+}$ (BK) channel because the open-state probability was increased with depolarization (e-fold change per $10.6{\pm}3.5$ mV, n=8) and internal $Ca^{2+}$ (half-activation at $16.7{\pm}3.8$ mV, n=8, pCa 4) and its conductance was large ($247{\pm}4.9$ pS, n=24 in 0.1 M KCI). Lifetime distributions of open- and closed-states could be fitted with single exponentials of several milliseconds. The mean open- and closed-lifetimes were linearly dependent on the intracellular $[Ca^{2+}]$ and $1/[Ca^{2+}]$, respectively. The second $K^{+}$ channel showed a conductance substate at $30{\sim}60%$ of the open state. Its current-voltage relation was linear in the range of $-80\;{\sim}\;+80\;mV$. The slope conductance of the substate and open-state were 40 and 144 pS in 0.2 M KCl, respectively. The channel was highly selective for $K^{+}$ over Cl. The open-state probability was weakly voltage-dependent (e-fold change per 35 mV. The lifetime distributions of open- and closed-states were fitted with two exponentials and the major gating occurred slowly at several hundred milliseconds. Based on the above results, we think the second type of $K^{+}$ channel is the sarcoplasmic reticulum $K^{+}$ (SRK) channel. In addition, both types of channel were also incorporated into the lipids extracted from the skeletal muscle. The channel properties recorded in the bilayers termed from synthetic and extracted lipids were qualitatively similar. Our data indicate that BK and SRK channels are rich in the skeletal muscle and their properties and regulation could be effectively studied in planar lipid bilayer.

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Analysis on Forward/Backward Current Distribution and Off-current for Doping Concentration of Double Gate MOSFET (DGMOSFET의 도핑분포에 따른 상 · 하단 전류분포 및 차단전류 분석)

  • Jung, Hakkee
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.17 no.10
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    • pp.2403-2408
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    • 2013
  • This paper has analyzed the change of forward and backward current for channel doping concentration to analyze off-current of double gate(DG) MOSFET. The Gaussian function as channel doping distribution has been used to compare with experimental ones, and the two dimensional analytical potential distribution model derived from Poisson's equation has been used to analyze the off-current. The off-current has been analyzed for the change of projected range and standard projected range of Gaussian function with device parameters such as channel length, channel thickness, gate oxide thickness and channel doping concentration. As a result, this research shows the off-current has greatly influenced on forward and backward current for device parameters, especially for the shape of Gaussian function for channel doping concentration.

An Analysis on the Omni-Channel Strategy of Distribution Enterprise in Domestic and International (국내·외 유통업체의 옴니채널 전략 활용현황 분석)

  • Oh, Jung-Ah
    • Korean Institute of Interior Design Journal
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    • v.25 no.5
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    • pp.111-120
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    • 2016
  • Unlike the past, brick-and-mortar is no longer on the priority list for the shopping activity. Instead, it is replaced by various non-store shopping alternatives, such as Internet, TV, catalog, mobile, etc. As consumers engage digitally, they made fewer trips to stores. Especially, as mobile shopping made the price comparison possible while shopping in the store, new shopping trend of 'showrooming' came to the fore as the serious issue. In order to cope with the this crisis, many brick-and-mortar retailers utilize omni-channel strategy for their countermeasure. This research paper is to suggest the omni-channel strategy that is applicable for the brick-and-mortar retailers. The results are as follows. First, in order to set up the connected-channel shopping environment, consumers have to be exposed to the environment that can deliver the continuous brand experience under the same price policy, brand and store management, etc, as integrating the various purchasing channels into one. Especially, in-store environment needs to change for the place where consumer experience is stressed for the most as using virtual reality devices with augmented reality technology. Also, the online digital kiosk, and tablet that consumer can order the products through the online channel while shopping in-store Second, the barrier-free in-store environment should be offered in order to increase the consumer convenience. This change will allow consumer communicate with the store environment more effectively. Lastly, brick-and-mortar should extend the physical territory as utilizing the offline's advantage and disadvantage through setting up the digital interactive wall or pop-up store for increasing the opportunity of customer interaction with the store. Moreover, visiting service for the elderly, housewife with the baby, or disabled person will be one of the effective substitute.

Change of voltage-gated potassium channel 1.7 expressions in monocrotaline-induced pulmonary arterial hypertension rat model

  • Lee, Hyeryon;Kim, Kwan Chang;Hong, Young Mi
    • Clinical and Experimental Pediatrics
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    • v.61 no.9
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    • pp.271-278
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    • 2018
  • Purpose: Abnormal potassium channels expression affects vessel function, including vascular tone and proliferation rate. Diverse potassium channels, including voltage-gated potassium (Kv) channels, are involved in pathological changes of pulmonary arterial hypertension (PAH). Since the role of the Kv1.7 channel in PAH has not been previously studied, we investigated whether Kv1.7 channel expression changes in the lung tissue of a monocrotaline (MCT)-induced PAH rat model and whether this change is influenced by the endothelin (ET)-1 and reactive oxygen species (ROS) pathways. Methods: Rats were separated into 2 groups: the control (C) group and the MCT (M) group (60 mg/kg MCT). A hemodynamic study was performed by catheterization into the external jugular vein to estimate the right ventricular pressure (RVP), and pathological changes in the lung tissue were investigated. Changes in protein and mRNA levels were confirmed by western blot and polymerase chain reaction analysis, respectively. Results: MCT caused increased RVP, medial wall thickening of the pulmonary arterioles, and increased expression level of ET-1, ET receptor A, and NADPH oxidase (NOX) 4 proteins. Decreased Kv1.7 channel expression was detected in the lung tissue. Inward-rectifier channel 6.1 expression in the lung tissue also increased. We confirmed that ET-1 increased NOX4 level and decreased glutathione peroxidase-1 level in pulmonary artery smooth muscle cells (PASMCs). ET-1 increased ROS level in PASMCs. Conclusion: Decreased Kv1.7 channel expression might be caused by the ET-1 and ROS pathways and contributes to MCT-induced PAH.

A Study about Implementation Method of Multi-Interface Multi-Channel 2.4GHz Active RFID Reader Protocol (다중인터페이스 다중채널 2.4GHz 능동형 RFID 리더 프로토콜 구현방법에 관한 연구)

  • Kim, Dong-Hyun;Lee, Chae-Suk;Kim, Jong-Doek
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.14 no.4
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    • pp.1005-1014
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    • 2010
  • When reader collect tags, we found that they tend to get together to specific interface in Multi-Interface Multi-Channel 2.4GHz Active RFID system. To solve this problem, we designed the LP-Combind and AP-Balanced protocol for load distribution between interfaces, then verified its superiority of the performance through the simulation. There are three problems to implement designed protocols in hardware of firmware-level. first, tag selects randomly the channel of reader and reader need the method which can change the channel of tags. second, reader has the synchronization problem between reader and tag. third, reader has problem that MCU of reader have to operate simultaneously dual interface. To slove this problems, we designed the message and implemented method for tag channel change and the protocol in order to adjust synchronization between reader and tag, Therefore, we compared and analyzed the performance of protocols by experiment. If LP windows size is same, the performance of LP-Combined protocol and AP-Balanced protocol which lower collision probability by its load distribution is more outstanding than single interface protocol performance.

Analysis of Subthreshold Characteristics for Device Parameter of DGMOSFET Using Gaussian Function

  • Jung, Hak-Kee
    • Journal of information and communication convergence engineering
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    • v.9 no.6
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    • pp.733-737
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    • 2011
  • This paper has studied subthreshold characteristics for double gate(DG) MOSFET using Gaussian function in solving Poisson's equation. Typical two dimensional analytical transport models have been presented for symmetrical Double Gate MOSFETs (DGMOSFETs). Subthreshold swing and threshold voltage are very important factors for digital devices because of determination of ON and OFF. In general, subthreshold swings have to be under 100mV/dec, and threshold voltage roll-off small in short channel devices. These models are used to obtain the change of subthreshold swings and threshold voltage for DGMOSFET according to channel doping profiles. Also subthreshold swings and threshold voltages have been analyzed for device parameters such as channel length, channel thickness and channel doping profiles.

CHANNEL FLOW WITH A STREAMWISE-PERIODIC ARRAY OF CIRCULAR CYLINDERS - PRIMARY INSTABILITY AND FLOW CHARACTERISTICS - (원형 실린더가 주기적으로 배열된 채널 유동 - 주 불안정성 및 유동특성 -)

  • Yoon, D.H.;Yang, K.S.;Kang, C.
    • 한국전산유체공학회:학술대회논문집
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    • 2010.05a
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    • pp.352-357
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    • 2010
  • A parametric study has been carried out to elucidate the characteristics of channel flow with a streamwise-periodic array of cylinders. This flow configuration is relevant to heat exchanger applications. The presence of cylinders in channel flow causes the attached wall boundary layer to separate, leading to significant change in flow instabilities. There exist two kinds of instabilities; flow undergoes a primary instability (Hopf bifurcaiton) at a lower Reynolds number, and the unsteady two-dimensional flow becomes unstable to three-dimensional disturbances at a higher Reynolds number. We report here the dependencies of the primary instability as well as the flow characteristics of the subsequent unsteady flow including flow-induced forces and Strouhal number of vortex shedding, on the distance between the cylinder and the channel wall.

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Effective Heat Transfer Using Large Scale Vortices (대와류를 이용한 채널 내 열전달 증진)

  • Yoon, Dong-Hyeog;Choi, Choon-Bum;Lee, Kyong-Jun;Yang, Kyung-Soo
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.32 no.3
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    • pp.198-206
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    • 2008
  • A numerical study has been carried out to investigate heat transfer enhancement in channel flow using large-scale vortices. A square cylinder, inclined with respect to the main flow direction, is located at the center of the channel flow, generating a separation region and Karman vortices. Two cases are considered; one with a fixed blockage ratio and the other one with a fixed cylinder size. In both cases, the flow characteristics downstream of the cylinder significantly change depending on the inclination angle. As a result, heat transfer from channel wall is significantly enhanced due to increased vertical-velocity fluctuations induced by the large-scale vortices shed from the cylinder. Quantitative results as well as qualitative physical explanation are presented to justify the effectiveness of the inclined square cylinder as a vortex generator to enhance heat transfer from channel wall.

Game-Theoretic Optimization of Common Control Channel Establishment for Spectrum Efficiency in Cognitive Small Cell Network

  • Jiao Yan
    • International journal of advanced smart convergence
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    • v.13 no.1
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    • pp.1-11
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    • 2024
  • Cognitive small cell networks, consisting of macro-cells and small cells, are foreseen as a promising candidate solution to address 5G spectrum scarcity. Recently, many technological issues (such as spectrum sensing, spectrum sharing) related to cognitive small cell networks have been studied, but the common control channel (CCC) establishment problem has been ignored. CCC is an indispensable medium for control message exchange that could have a huge significant on transmitter-receiver handshake, channel access negotiation, topology change, and routing information updates, etc. Therefore, establishing CCC in cognitive small cell networks is a challenging problem. In this paper, we propose a potential game theory-based approach for CCC establishment in cognitive radio networks. We design a utility function and demonstrate that it is an exact potential game with a pure Nash equilibrium. To maintain the common control channel list (CCL), we develop a CCC update algorithm. The simulation results demonstrate that the proposed approach has good convergence. On the other hand, it exhibits good delay and overhead of all networks.