• Title/Summary/Keyword: Transport circuit

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Design of a Module for Oscillation Detection in an Integrated PCS and W-CDMA Receiver

  • Park Joung-Geun;Lee Jong-Chul
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.4 no.1 s.6
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    • pp.73-79
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    • 2005
  • In this paper, a circuit for detecting a fine oscillation in an integrated PCS and W-CDMA receiver is presented. The advantages for this design are small size and flexible compatibility for system operation compared with the conventional method. The fine oscillation level can be detected by dB unit through selecting the receiver mode as PCS of 1.8 GHz range or W CDMA of 1.9 GHz range by a RF switch and monitoring the corresponding frequency band. Also, the circuit is designed to be flexible for other communication systems with the consideration of the required dynamic range of 75 dB.

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Dual-band L-section Impedance Transformer (이중 대역 L형 임피던스 변환기)

  • Park, Myun-Joo
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.9 no.5
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    • pp.67-71
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    • 2010
  • This paper proposes new dual-band impedance transformers based on the L-section circuit topology. The proposed circuits consist of a transmission line section with a stub line either at the source or at the load end. The dual-band operating conditions are analyzed in detail and simple design equations are derived in terms of the line lengths and impedances for the different circuit topologies and load conditions. The dual-band operation is confirmed through the design, fabrication and measurement in microstrip circuits based on the proposed method.

The development of computational fluid dynamics tools for thermal expansion type interrupter with the arc rotary (아크회전과 열팽창 방식을 적용한 소호부에 대한 아크유동 해석)

  • Choulkov, Victor;Lee, B.W.;Seo, J.M.
    • Proceedings of the KIEE Conference
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    • 2000.07b
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    • pp.813-815
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    • 2000
  • This paper is concerned with the development of PC based computer simulation and design tools for auto-expansion SF6 circuit breaker with the arc rotary. The simulation model takes into account radiation transport, turbulence enhanced momentum. energy transport. The conversation gas dynamic equation together with Maxwells equations are solved. For the arc simulation the straightforward procedure has been used. The temperature, gas density and velocity space distributions within the circuit breaker are simulated in details. The presented results show that the computer simulation of gas flow in SF6 interrupter is a subject of much interest for design and optimization of contacts. The presented results show that the shape and sizes of contacts are chosen by this tool from judiciously compromise between electrical breakdown strength and interruption ability that are functions of gas flow parameters.

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Optimized Design Technique of The EMI(Electro Magnetic Interference) Noise Reduction for Wireless Video Stream System (무선 비디오 스트림 시스템 EMI 잡음 개선 방안)

  • Park, Kyoung-Jin;Kim, Jung-Min;Ra, Keuk-Hwan
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.11 no.4
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    • pp.112-120
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    • 2012
  • In this paper, we manufactured the wireless video stream system after we scanned EMI(Electro Magnetic Interference)noise in the system. and then, we analysed the noise frequency in the interface, circuit and PCB(Printed Circuit Board). we suggested EMI noise reduction technique. The applied reduction method is low pass filtering, the internal layer placement for high speed video data line and optimization of the system ground condition. the manufactured system improved about 2 ~ 20[dB] margin for EMI limit 40[dBuV/m] at 30 ~ 230[MHz] and 47[dBuV/m] at 230 ~ 1000[MHz].

Prospects and Problems in the Study of Geography related to the Concept of Commodity, Transport, and Supply Chains (상품.교통.공급사슬개념과 관련된 지리학의 연구와 과제)

  • Han, Ju-Seong
    • Journal of the Korean Geographical Society
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    • v.44 no.6
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    • pp.723-744
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    • 2009
  • The purpose of this paper is to clarify the prospects and problems in the study of geography related to the concept of commodity, transport, and supply chains. The geography studies related to commodity chains are expanded to each field of industry focusing on the subjects and economic difference which lead the commodity chain in core and periphery regions. These vertical connection are studied with the political economy approach that gives attention to geographical pattern of agricultural products and foods. But in viewpoint of commodity circuit and commodity network, the culture or subjects of micro regions and interaction are also studied. The contents of these study are to clarify the importance of cultural turn and local. And the study of chain standpoint appears that the series of transport process by transportation modes can be understood by transport chains and the physical distribution process of sea freight is to be grasped by supply chains.

An analysis on the headway of urban rail transit (도시철도 시스템에서의 운행 시격 분석)

  • Bang, Yung;Kim, Hyung-Hoon;Um, Jung-Kyou;Cho, Yong-Gi
    • Proceedings of the KSR Conference
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    • 2006.11b
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    • pp.1495-1500
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    • 2006
  • A signal system is critical point of transport capacity and train operation in urban rail transit. Today the moving block system by radio is taking place of the fixed block system by track circuit for efficiency and short headway in underground railway and right rail transit. In this study, assuming specification of a train, track and control system, the minimum headway on the moving block system and the fixed block system is researched for the maximum transport capacity.

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Analysis of Electron Transport Coefficients in Low Voltage Air Circuit Breaker Using MCS and BE (몬테칼로 시뮬레이션과 볼츠만 방정식을 이용한 저전압 기중차단기의 전자수송계수 특성파악)

  • 하성철;서상현
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.16 no.2
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    • pp.168-172
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    • 2003
  • The electron transport coefficients in Air is analysed in range of E/Nvalues from 100~1000(Td) by a MCS and BE method. This paper have calculated W, ND$\sub$L/, ND$\sub$T/, Mean energy mixtures by N$_2$+O$_2$. The results gained that the values of the electron swarm parameters such as the electron drift velocity, longitudinal and transverse diffusion coefficients.

Nanostructured Polymer Electrolytes for Li-Batteries and Fuel Cells

  • Park, Mun-Jeong
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2012.05a
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    • pp.71.2-71.2
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    • 2012
  • There are rising demands for developing more efficient energy materials to stem the depletion of fossil fuels, which have prompted significant research efforts on proton exchange fuel cells (PEFCs) and lithium ion batteries (LIBs). To date, both PEFCs and LIBs are being widely developed to power small electronics, however, their utilization to medium-large sized electric power resources such as vehicle and stationary energy storage systems still appears distant. These technologies increasingly rely upon polymer electrolyte membranes (PEMs) that transport ions from the anode to the cathode to balance the flow of electrons in an external circuit, and therefore play a central role in determining the efficiency of the devices; as ion transport is a kinetic bottleneck compared to electrical conductivity, enormous efforts have been devoted to improving the transport properties of PEMs. In present study, we carried out an in-depth analysis of the morphology effects on transport properties of PEMs. How parameters such as self-assembled nanostructures, domain sizes, and domain orientations affect conductivities of PEMs will be presented.

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