• Title/Summary/Keyword: electronic communications

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Distributed RC Sinusoidal Oscillator Control Frequency by One Pole Amplifier

  • Pirajnanchai, Virote;Songthanapitak, Numyoot;Janchitrapongvej, Kanok
    • 제어로봇시스템학회:학술대회논문집
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    • 2004.08a
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    • pp.570-573
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    • 2004
  • This paper present a distributed RC lines (URCs) oscillator with sinusoidal output. The frequency of oscillator can be controlled and adjustable by varying an one pole amplifier. The circuit incorporated an gain controller loop for amplitude stabilization with low distortion. The realization of simulation and experimental results are in reasonably good agreement with the theoretical , and very low harmonic distortion. In this circuit can be suitable for LSI process fabrication and the circuit application in electronic communications system.

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On-line ADR Method on Electronic Commerce Disputes in Cyberspace (전자상거래 분쟁발생시 사이버공간에서의 대안적 분쟁해결(ADR) 방안에 관한 연구)

  • Kim, Sun-Kwang
    • International Commerce and Information Review
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    • v.5 no.1
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    • pp.159-177
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    • 2003
  • As many kinds of transactions and informations move onto the Internet, methods to resolve dispute arising from this trend must also move onto the Internet. The Internet has heightened interest in Alternative Dispute Resolution(ADR). Some organizations are using the new technology in the field of dispute resolution, for example, by establishing web sites and offering communications through the Internet. Online ADR provides an attractive solution to an important part of the jurisdictional challenges presented by the Internet. This study reviews the types of online ADR as the dispute settlement way in electronic commerce. Especially this paper points out the task that Korea has to promote the online ADR for more effective and efficient dispute settlements.

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High-Speed Intra Prediction VLSI Implementation for HEVC (HEVC 용 고속 인트라 예측 VLSI 구현)

  • Jo, Hyeonsu;Hong, Youpyo;Jang, Hanbeyoul
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.41 no.11
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    • pp.1502-1506
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    • 2016
  • HEVC (High Efficiency Video Coding) is a recently proposed video compression standard that has a two times greater coding efficiency than previous video compression standards. The key factors of high compression performance and increasement of computational complexity are the various types of block partitions and modes of intra prediction in HEVC. This paper presents an intra prediction hardware architecture for HEVC utilizing pipelining and interleaving techniques to increase the efficiency and performance while reducing the requirement for hardware resources.

Compact-Size Fractal Antenna with Stable Radiation Properties for Wi-Fi and WiMAX Communications

  • Abed, Amer T.;Singh, Mandeep S.J.;Islam, Mohammad Tariqul
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.12 no.6
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    • pp.2734-2747
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    • 2018
  • In this study, a novel fractal ring antenna with a compact size of $24{\times}9{\times}0.8mm^3$ was configured using three iterations. Low profile, circular polarization, and measured operating bands (4.5-6.5 GHz) meet specifications of the upper band used in Wi-Fi and WiMAX applications. The antenna featured, stable radiation properties, especially gain and efficiency, in the notched band (92%). In deep, the antenna impedance, reflection coefficients, surface current distribution and circular polarization for the three iterations had been studied to improve the process of antenna design and its radiation characteristics.

A Study of the Quantitative Relationship of Charge-Density Changes and the Design Area of a Fabricated Solar Cell

  • Jeon, Kyeong-Nam;Kim, Seon-Hun;Kim, Hoy-Jin;Kim, In-Sung;Kim, Sang-Hyun
    • Transactions on Electrical and Electronic Materials
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    • v.12 no.5
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    • pp.204-208
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    • 2011
  • In this paper, the design area of a fabricated solar cell has been analyzed with respect to its charge density. The mathematical calculation used for charge-density derivation was obtained from the 2001 version of a MATHCAD program. The parameter range for the calculations was ${\pm}1{\times}10^{17}cm^{-3}$, which is in the normal parameter range for n-type doping impurities ($7.0{\times}10^{17}cm^{-3}$) and also for p-type impurities ($4.0{\times}10^{17}cm^{-3}$). Therefore, it can be said that the fabricated solar-cell design area has a direct effect on charge-density changes.

The Algorithm for Deinterleaving of Multi-Step Stagger PRI Signals of Pulse Radars (펄스 레이더의 다단 Stagger PRI 신호분리 알고리즘)

  • Lim, Joong-Soo
    • Journal of Satellite, Information and Communications
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    • v.8 no.4
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    • pp.159-163
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    • 2013
  • In this paper, we propose a new method to deinterleave multi-stage stagger PRI signals of pulse radars using the electronic intelligence systems. While former algorithms were based on hardware PRI tracker only using the first deviation of the TOA of radar signals, this paper uses the first and the second deviation of TOA of radar signals and uses the PRI histogram method to deinterleave multiple PRIs of pulse radars. This algorithm can be used for deinterleaving various PRI signals at electronic intelligence systems.

The Design of Power Amplifier for Multimode Wireless Communications (다중모드 무선통신용 전력증폭기 설계에 관한 연구)

  • Kim Tae-Won;Seo Chul-Hun;Jang Uk-Tae
    • 한국정보통신설비학회:학술대회논문집
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    • 2002.08a
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    • pp.35-38
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    • 2002
  • 본 논문에서는 5.8GHz 대역 무선 랜과 차세대 이동통신서비스인 IMT-2000 양 대역에서 동작하는 이중대역 전력증폭기 선계 및 제작에 관하여 기술하였다. 최종 출력목표는 1W이며, 2GHz와 5GHz의 이중밴드로 동작하기 위해 2개의 능동소자를 사용하여, 2개의 독립적인 증폭기를 제작한 후 바이어스 제어회로를 통하여 두 대역을 결합시켰다. 바이어스 제어회로에서 모드 제어 전압 $V_m$의 전압변화에 따라 양 모드간의 변환이 이루어진다.

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A Signal Detection and Estimation Method Based on Compressive Sensing (압축 센싱 기반의 신호 검출 및 추정 방법)

  • Nguyen, Thu L.N.;Jung, Honggyu;Shin, Yoan
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.40 no.6
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    • pp.1024-1031
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    • 2015
  • Compressive sensing is a new data acquisition method enabling the reconstruction of sparse or compressible signals from a smaller number of measurements than Nyquist rate, as long as the signal is sparse and the measurement is incoherent. In this paper, we consider a simple hypothesis testing in target detection and estimation problems using compressive sensing, where the performance depends on the sparsity level of the signals being detected. We provide theoretical analysis results along with some experiment results.

Photopolymer-based Surface-normal Input/Output Volume Holographic Grating Coupler for 1550-nm Optical Wavelength

  • Lee, Kwon-Yeon;Jeung, Sang-Huek;Cho, Byung-Mo;Kim, Nam
    • Journal of the Optical Society of Korea
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    • v.16 no.1
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    • pp.17-21
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    • 2012
  • A surface-normal input/output volume holographic grating coupler (VHGC) operating at 1550nm wavelength region by using a $10{\mu}m$-thick DuPont photopolymer film is designed and fabricated. The angular and wavelength responses of the input/output VHGC are investigated in order to validate applicability of this device in integrated optics and optical communications. The effect of incident-beam position on the output reflectance to determine optimum condition for input coupling is also presented. The fabricated input/output VHGC exhibited an angular selectivity of ${\sim}0.027^{\circ}$, a wavelength selectivity of ~0.8 nm, and an output peak reflectance of 34.13%.

Performance of Distributed MISO Systems Using Cooperative Transmission with Antenna Selection

  • Park, Jong-Hyun;Kim, Jae-Won;Sung, Won-Jin
    • Journal of Communications and Networks
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    • v.10 no.2
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    • pp.163-174
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    • 2008
  • Performance of downlink transmission strategies exploiting cooperative transmit diversity is investigated for distributed multiple-input single-output (MISO) systems, for which geographically distributed remote antennas (RA) in a cell can either communicate with distinct mobile stations (MS) or cooperate for a common MS. Statistical characteristics in terms of the signal-to-interference-plus-noise ratio (SINR) and the achievable capacity are analyzed for both cooperative and non-cooperative transmission schemes, and the preferred mode of operation for given channel conditions is presented using the analysis result. In particular, we determine an exact amount of the maximum achievable gain in capacity when RAs for signal transmission are selected based on the instantaneous channel condition, by deriving a general expression for the SINR of such antenna selection based transmission. For important special cases of selecting a single RA for non-cooperative transmission and selecting two RAs for cooperative transmission among three RAs surrounding the MS, closed-form formulas are presented for the SINR and capacity distributions.