• Title/Summary/Keyword: Electronic transport

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The measurement of electron drift velocity and analysis of transport coefficients in $SF_6$ gas ($SF_6$가스의 전자이동속도 측정 및 수송계수 해석)

  • 하성철;하영선;윤상호;전병훈;백승권
    • Electrical & Electronic Materials
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    • v.6 no.6
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    • pp.524-535
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    • 1993
  • 본 연구에서는 SF$_{6}$가스의 전자이동속도를 더블히트파이프 실험장치를 이용하여 유도전류법에 의해 실험적으로 측정하였다. 그리고 전자수송계수의 정량적인 산출은 볼츠만 수송 방정식의 Backward-Prolongation을 이용하여 계산하고 해석하였다. 이때 전자에너지 분포함수와 전리 및 부착계수를 구하고 운동량변환단면적을 결정하였다. 그리고 실험적으로 측정된 SF$_{6}$가스의 전자이동속도와 계산된 전자수송계수를 비교 검토하여 해석함으로서 절연체의 기초적인 물성자료로 사용할 수 있다.

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Characteristics of blue phosphorescent OLED with partially doped simple structure (부분 도핑을 이용한 단순구조 청색인광 OLED 특성)

  • Kim, Tae-Yong;Moon, Dae-Gyu
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2010.06a
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    • pp.156-156
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    • 2010
  • We have developed highly efficient blue phosphorescent organic light-emitting devices (OLED) with simplified architectures using blue phosphorescent material. The basis device structure of the blue PHOLED was anode / emitting layer (EML) / electron transport layer (ETL) / cathode. The dopant was partially doped into the host layer for investigating recombination zone, current efficiency, and emission characteristics of the blue PHOLEDs.

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Electrical Property of Polyvinylalcohol (Polyvinylalcohol의 전기적 특성)

  • 김현철;김종욱;구할본
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1994.11a
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    • pp.156-159
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    • 1994
  • The electrical property of polyvinylalcohol (PVA) films (several hundreds ∼ several $\mu\textrm{m}$ in thickness) formed by sphere bulb blowing technique, has been studied. The electrical conductivity of relatively thick films (>several thousands ) has been very high and enhanced by the exposure either to high humidity fo air or NH$_3$. which can be explained in terms of the role of ionic transport. The use of PVA film as NH$_3$ sensor is also proposed. In PVA films less than 1500 , two conducting states: high conducting and low conducting states, are observed.

Structure and Physical Properties of $YSe_{1.83}$

  • 김성진;오훈정
    • Bulletin of the Korean Chemical Society
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    • v.16 no.6
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    • pp.515-518
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    • 1995
  • YSe1.83 was synthesized by vapor transport technique and its crystal structure was determined. The structure was isostructure of LaTe2-x, which was layered structure consisting of two-atom thick layers of YSe with distorted NaCl-type structure and one-atom thick layer of Se. The substructure of YSe1.83 was tetragonal with space group of P4/nmm and a=4.011(2) and c=8.261(3) Å with final R/Rw=6.4/6.9 %. The superstructure with asuper=2a, bsuper=6b and csuper=2c was found. The measurements of electronic and magnetic properties of this compound indicate that it is an electronic insulator and diamagnet.

A Study of Flow-based QoS Management in Packet Transport Network (패킷 전송망에서의 플로우 기반 QoS 관리 방안 연구)

  • Choi, Chang-Ho;Kim, Whan-Woo
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.48 no.11
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    • pp.73-82
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    • 2011
  • As a demand of IP based packet service is increasing, transport network is evolving from circuit based transport technology using TDM to Ethernet based packet transport technology. In this paper we introduce packet transport network based on PBB-TE and MPLS-TP and propose a quality of service(QoS) management scheme to satisfy various user requirements in packet transport network. The proposed flow-based QoS management scheme guarantees that per-flow bandwidth control satisfies the predefined QoS requirement perfectly under bandwidth congestion condition by using perflow and per-PTL tunnel management. In order to evaluate the proposed scheme we defined flow and PTL tunnel per input frame and configured QoS parameters for each flow and PTL tunnel respectively. Simulation was done by using OPNET modeler 16.0 version.

Conduction Mechanism of Charge Carriers in Electrodes and Design Factors for the Improvement of Charge Conduction in Li-ion Batteries

  • Akhtar, Sophia;Lee, Wontae;Kim, Minji;Park, Min-Sik;Yoon, Won-Sub
    • Journal of Electrochemical Science and Technology
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    • v.12 no.1
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    • pp.1-20
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    • 2021
  • In-depth knowledge of electrode processes is crucial for determining the electrochemical performance of lithium-ion batteries (LIBs). In particular, the conduction mechanisms of charged species in the electrodes, such as lithium ions (Li+) and electrons, are directly correlated with the performance of the battery because the overall reaction is dependent on the charge transport behavior in the electrodes. Therefore, it is necessary to understand the different electrochemical processes occurring in electrodes in order to elucidate the charge conduction phenomenon. Thus, it is essential to conduct fundamental studies on electrochemical processes to resolve the technical challenges and issues arising during the ionic and electronic conduction. Furthermore, it is also necessary to understand the transport of charged species as well as the predominant factors affecting their transport in electrodes. Based on such in-depth studies, potential approaches can be introduced to enhance the mobility of charged entities, thereby achieving superior battery performances. A clear understanding of the conduction mechanism inside electrodes can help overcome challenges associated with the rapid movement of charged species and provide a practical guideline for the development of advanced materials suitable for high-performance LIBs.

Molecular Conductance Switching Processes through Single Ruthenium Complex Molecules in Self-Assembled Monolayers

  • Seo, So-Hyeon;Lee, Jeong-Hyeon;Bang, Gyeong-Suk;Lee, Hyo-Yeong
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.02a
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    • pp.27-27
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    • 2011
  • For the design of real applicable molecular devices, current-voltage properties through molecular nanostructures such as metal-molecule-metal junctions (molecular junctions) have been studied extensively. In thiolate monolayers on the gold electrode, the chemical bonding of sulfur to gold and the van der Waals interactions between the alkyl chains of neighboring molecules are important factors in the formation of well-defined monolayers and in the control of the electron transport rate. Charge transport through the molecular junctions depends significantly on the energy levels of molecules relative to the Fermi levels of the contacts and the electronic structure of the molecule. It is important to understand the interfacial electron transport in accordance with the increased film thickness of alkyl chains that are known as an insulating layer, but are required for molecular device fabrication. Thiol-tethered RuII terpyridine complexes were synthesized for a voltage-driven molecular switch and used to understand the switch-on mechanism of the molecular switches of single metal complexes in the solid-state molecular junction in a vacuum. Electrochemical voltammetry and current-voltage (I-V) characteristics are measured to elucidate electron transport processes in the bistable conducting states of single molecular junctions of a molecular switch, Ru(II) terpyridine complexes. (1) On the basis of the Ru-centered electrochemical reaction data, the electron transport rate increases in the mixed self-assembled monolayer (SAM) of Ru(II) terpyridine complexes, indicating strong electronic coupling between the redox center and the substrate, along the molecules. (2) In a low-conducting state before switch-on, I-V characteristics are fitted to a direct tunneling model, and the estimated tunneling decay constant across the Ru(II) terpyridine complex is found to be smaller than that of alkanethiol. (3) The threshold voltages for the switch-on from low- to high-conducting states are identical, corresponding to the electron affinity of the molecules. (4) A high-conducting state after switch-on remains in the reverse voltage sweep, and a linear relationship of the current to the voltage is obtained. These results reveal electron transport paths via the redox centers of the Ru(II) terpyridine complexes, a molecular switch.

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Design and manufacture of course banned book bis system that apply thinclient of J2ME base and DSRC technology (J2ME 기반의 씬클라이언트와 DSRC 기술을 적용한 과금서비스 시스템의 설계와 제작)

  • Kim, Whi-Young
    • Proceedings of the KIEE Conference
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    • 2003.04a
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    • pp.128-132
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    • 2003
  • The increase of vehicles stagnations leads to the increasing attention to the way customers pay and a large number of projects on electronic cash system. Transport system is comprised of a number of advanced technologies, including information processing, communications, control, and electronics. Recently many research on a system which provides contact in order to protect driver's vehicle passage have been carried out. And some potential problems from that system are being reviewed by electronic cash system. In this papers, we suggest RF protocol developing technology using the concept of electronic cash. ATM electronic cash developing is consist of component of pre-developed coin throw, integration of component using its, and production of more requirement-satisfactory ITS solution. Result increase 15-40% pre-type vehicles stagnations. Especially, we expect this proposed concept would be well adapted to our national environments

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Design and Implementation ATM communication e-pay using PSTN / leased line (PSTN을 이용한 비동기 방식의 프로토콜 설계와 구현)

  • 김휘영
    • Proceedings of the IEEK Conference
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    • 2002.06e
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    • pp.161-164
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    • 2002
  • The increase of vehicles stagnations leads to the increasing attention to the way customers pay and a large number of projects on electronic cash system. Transport system is comprised of a number of advanced technologies, including information processing, communications, control, and electronics. Recently many research on a system which provides contact in order to protect driver's vehicle passage have been carried out. And some potential problems from that system are being reviewed by electronic cash system. In this papers, we suggest RF protocol developing technology using the concept of electronic cash. ATM electronic cash developing is consist of component of pre-developed coin throw, integration of component using its, and production of more requirement-satisfactory ITS solution. Result increase 15∼40% pre-type vehicles stagnations. Especially, we expect this proposed concept would be well adapted to our national environments.

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Electronic Structures and Physical Properties of the Ordered and Disordered $Ni_2$MnGa Alloy Films

  • Kim, K. W.;Lee, N. N.;Y. Y. Kudryavtsev;Lee, Y. P.
    • Journal of the Korean Vacuum Society
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    • v.12 no.S1
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    • pp.104-106
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    • 2003
  • In this study, the electronic structures and physical properties of Ni$_2$MnGa alloy films and their dependence on the order-disorder structural transitions were investigated. The results show that the ordered films behave nearly the same as the bulk $Ni_2$MnGa alloy, including the martensitic transformation at 200 K. Unexpectedly, the disordering in $Ni_2$MnGa alloy films does not lead to any appreciable magnetic ordering down to 4 K. An annealing of the disordered films restores the ordered structure with an almost full recovery of the magnetic and the transport properties of the ordered $Ni_2$MnGa alloy films. A possible explanation of the disappearance of magnetic moment in the disordered film is given by using the ab initio first-principles electronic-structure calculations.