• Title/Summary/Keyword: Telecommunication

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Differential-Average Transmitted Reference Ultra-Wideband Communication Systems (Differential-Average Transmitted Reference Ultra-Wideband 통신 시스템)

  • Kim, Se-Kwon;Kim, Jae-Woon;Park, Young-Jin;Lee, Soon-Woo;Kim, Yong-Hwa;Shin, Yo-An
    • Proceedings of the IEEK Conference
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    • 2008.06a
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    • pp.309-310
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    • 2008
  • In this paper, we propose a novel D-ATR (Differential-Average Transmitted Reference) scheme for UWB (Ultra Wide Band) based on impulse radio. The proposed scheme utilizing differential coding at transceiver, does not cause half loss of data rate unlike the conventional TR (Transmitted Reference) and ATR (Average TR) systems which transmit additional reference signals. In addition, the proposed scheme may provide improved BER (Bit Error Rate) performance by averaging the received reference signals like the conventional ATR. The proposed D-ATR receiver produces the averaged reference template by considering both the detected data bit and the differential coding rule.

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A Methodology for Variable Structure System Specification: Formalism, Framework, and Its Application to ATM-Based Network System

  • Lee, Kyou-H.;Choi, Kil-Y.;Kim, Jae-G.;Vansteenkiste, G.C.
    • ETRI Journal
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    • v.18 no.4
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    • pp.245-264
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    • 1997
  • This paper presents a formalism-based methodology and its implemented environment which constitutes a sound framework for real-time systems development. The software and/or hardware systems developed in such a formal manner are well structured and maintainable. We first propose a set-theoretic VSSS (Variable Structure System Specification) formalism. This formalism is the core of the presented methodology which supports a means of formal specification for real-time systems. We then develop the environment, including VSSS language definition, a translator for the language, and supporting libraries for real-time execution. Finally, a demonstration of the methodology in development of a real-time event manager, a subsystem of an ATM-based communication system, shows the correctness and efficiency of the methodology.

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Characteristics of the Voltages between the Communication Lines and Ground Induced by the Adjacent Artificial High-Voltage or Current ELF Source

  • Lee, Sang-Mu;Choi, Mun-Hwan;Cho, Pyung-Dong;Eun, Chang-Soo;Gimm, Yoon-Myoung
    • Journal of electromagnetic engineering and science
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    • v.9 no.4
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    • pp.175-181
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    • 2009
  • The measurements were performed to verify experimentally that the voltage arising on a telecommunication line by a power line is due to the induction phenomena because there has been an opinion that the arising voltage on a telecommunication line is not by induction, but by other causality. The voltage appeared on the telecommunication line by way of an electric field or magnetic field generated by the source apparatus that had been artificially made to provide intentional constant high-voltage or current in ELF, that is, 60 Hz as an emulated commercial power.

Vehicle Multimedia Encapsulating Module Design using by Axiomatic Design Approach (공리적 설계기법을 이용한 차량용 멀티미디어 탑재 모듈의 기구설계)

  • Park, Jeong-Min;Lee, Jong-Soo
    • Proceedings of the KSME Conference
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    • 2003.04a
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    • pp.1205-1211
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    • 2003
  • Having information is most important at the present age. Internet is main source of obtaining information and mobile telecommunication let people communicate each other without any time and space limitation. Recently, advanced technology in telecommunication makes two-way service possible. So, the mobile internet service combined internet with mobile telecommunication is widely and rapidly promoted. Therefore user can transmit and receive a lot of information without time and space restriction using various application technologies. This paper deals with machinery that makes human do office work conveniently in vehicle using mobile internet service. Namely, it tries to design mobile internet machinery combining of wireless payment, GPS module, mobile internet, and mobile office etc. And that can transmit and receive e-mail or documents etc. This machinery has various objects, and design process has complexity. To reduce trial error and processing complexity, Axiomatic Design Method is used to design the machinery.

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Reliability Growth Analysis for In-service PCS Telecommunication System (PCS 교환기의 In-service 신뢰도 성장 분석)

  • Jung, Won;Chang, Soon-Tae
    • Journal of Korea Society of Industrial Information Systems
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    • v.5 no.4
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    • pp.39-46
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    • 2000
  • New products often have in-service reliability problem despite an intensive development program. Therefore reliability data must be collected and analyzed, and improvements designed and implemented. A type of reliability incentive contract which has recently attracted a lot of attention is reliability improvement warranty(RIW). It has been employed by military, airlines, telecommunication systems, and public utilities. An RIW contract requires that the supplies carries out all repairs, modify the equipment to improve its reliability, and provides all spates needed, for a fixed period, for once-off fee. This paper presents the reliability growth analysis and management methods for in-service MC68 microprocessor, which is the main component of the base station controller in PCS(Personal Communication Service) telecommunication system. The methods will provide guidelines to monitor reliability program in planning RIW contract.

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A Study on Identification of Nonminimum Phase Stable System from Partial Impulse Response Sequences

  • Lee, Won-Cheol;Bae, Myung-Jin;Im, Sung-Bin
    • The Journal of the Acoustical Society of Korea
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    • v.15 no.1E
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    • pp.45-58
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    • 1996
  • This paper addresses the problem of identifying the class of all stable system transfer functions that interpolate the given partial impulse response sequence. In this context, classical Pade approximations that are also stable, are shown to be a special case of this general formulation. The theory developed in this connection is utilized to obtain a new criterion for determining the model order and system parameters for rational systems, and, further, to generate nonminimum phase optimal stable rational approximatinos of nonrational systems from its impulse response sequence.

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An Overview Of Nanonet Based Dye-Sensitized Solar Cell (DSSC) In Solar Cloth

  • Othman, Mohd Azlishah;Ahmad, Badrul Hisham;Amat, Noor Faridah
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.13 no.6
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    • pp.635-646
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    • 2013
  • This technical paper contains the information of the Dye-Sensitized Solar Cells (DSSC) working principal where diffusion mechanism acts as electron transport to absorb the sunlight energy to generate the electrical energy. DSSC is photo electrochemical cell that implements the application of photosynthesis process. The performance of electron transport in DSSC has been reviewed in order to enhance the performance and efficiency of electron transport. The improvement of the electron transport also discussed in this paper.

A study on the numbering plan between IP and ATM on KII (초고속 통신망에서 IP와 ATM 번호의 연동방안)

  • Kim, Sung-Han;Hwang, Gunn;Oh, Haeng-Suk;Choi, Jun-Kyun
    • Proceedings of the IEEK Conference
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    • 1999.11a
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    • pp.791-794
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    • 1999
  • A principle requirement and technical standardization for numbering plan is required to B-lSDN network planning. Especially, internetworking high speed network with other conventional networks like PSTN, PSDN and ISDN is generally considered for integration. This paper describes the numbering plan for operation between internet and ATM. And based on the ITU-U specification, numbering plan is compared between conventional and high speed networks. Additionally, numbering plan for ATM-forum is analyzed.

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Quasi-Complementary Turbo Codes (QCTC) for cdma2000 1xEV-DV

  • Kim, Min-Goo;Ha, Sang-Hyuk;Kim, Yong-Serk
    • Proceedings of the IEEK Conference
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    • 2003.07a
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    • pp.97-100
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    • 2003
  • The quasi-complementary turbo codes (QCTC) proposed by Kim [1] is used for a fast hybrid ARQ scheme with incremental redundancy and adaptive modulation coding in the cdma2000 1xEV-DV [2]. The QCTC provides various code rates with good performance, a very simple encoder structure, and an inherent channel interleaving. It is shown that the QCTC is a unified scheme of channel coding and channel interleaving. In this paper, we introduce the properties of QCTC and various hybrid ARQ-QCTC schemes for the system.

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A Study on the Simple Sound Absorption Method Using Acoustic Characteristics (음향특성을 이용한 간이 흡음방안에 관한 연구)

  • Park, Sang-Bum;Kim, Bong-Young;Bae, Myung-Jin
    • Proceedings of the Korean Society of Computer Information Conference
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    • 2017.01a
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    • pp.197-198
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    • 2017
  • 현대사회는 인구의 증대에 따른 교통, 건물 그리고 환경등 여러 가지 분야에서 눈부신 발전을 거듭하고 있다. 하지만, 거주환경이 발전하면서 나타나는 소음을 저감하고자 본 논문에서는 간이 흡음재인 계란판의 흡음특성을 3가지 환경에서 측정한 데이터를 비교분석하였다. 실험을 하기위해 가로, 세로, 높이1000mm의 정사각형 상자를 만들어 진행하였다. 실험은 간이 흡음재 부착, 미부착 그리고 방음실에서 음원을 각각 5회씩 재생시킨 후 잔향시간을 측정하여 비교분석하였다. 그 결과, 간이흡음재 미부착시 평균0.413초, 부착시 평균0.330초 그리고 방음실에서 평균0.319초의 데이터를 얻었다.

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