• 제목/요약/키워드: data communications

검색결과 5,474건 처리시간 0.041초

국내 데이타 통신회선의 특성 분석 (The Analysis of Local Dabta Communication Line Characteristics)

  • 김동규
    • 대한전자공학회논문지
    • /
    • 제16권5호
    • /
    • pp.1-11
    • /
    • 1979
  • 1960년대 후반 이후 전세계적으로 정보 산업의 가장 중요하고 미개척된 분야의 하나로서 data 통신/컴퓨터 통신이 급격히 대두되어 그 영향력을 광범위하게 확산시키기 시작하였다. 이의 구현을 위하여서는 먼저 통신 채널의 여러가지 고유한 특성이 구명되고 그 신뢰도가 확인되어야 하는 것이 선결 문제이다. 본 논문은 1973년도 이후부터 현재까지 이 분야에 축적된 데이타를 집대성하고 조직적으로 분석하여 몇가지 기본적인 근거를 제시하고 발전적 제안을 하였다. 전용선과 공중선, 통신 속도, 통신 형태, block의 크기, 측정 구간의 지역적 특성등에 따른 통신채널의 최종적 외부 특성인 error rate, 주파수 특성, 직류 특성등을 분석하고 논하였으며 block의 크기가 performance에 미치는 영향을 해석하여 보았다. 또한 9300BPS급의 고속도 통신의 가능성 크기가 performance에 미치는 영향을 해석하여 보았다. 또한 9600BPS급의 고속도 통신의 가능성을 검토하였다.

  • PDF

Derivation of Closed Form Channel Capacity Using Confluent Hypergeometric Function for Wireless MIMO

  • Kabir, S.M. Humayun;Pham, Van-Su;Mai, Linh;Yoon, Giwan
    • 한국정보통신학회:학술대회논문집
    • /
    • 한국해양정보통신학회 2008년도 춘계종합학술대회 A
    • /
    • pp.47-50
    • /
    • 2008
  • Multiple-input multiple-output (MIMO) is an efficient technology to increase data rate in wireless networks due to bandwidth and power limitations. Data transmission rate between transmitter and receiver is determined by channel capacity. MIMO has anadvantage of reliable communication over wireless channel because of utilizing the channel capacity properly. In this letter, we drive a new formula, closed form capacity formula, using confluent hypergeometric function.

  • PDF

A hybrid coding method for motion-blur reduction in LCD overdrive

  • Park, Sang-Yoon;Wang, Jun;Min, Kyeong-Yuk;Chong, Jong-Wha
    • 대한전자공학회:학술대회논문집
    • /
    • 대한전자공학회 2008년도 하계종합학술대회
    • /
    • pp.1143-1144
    • /
    • 2008
  • 본 논문에서는 motion-blur를 감소시키는 overdriving 기술의 오류를 감소시키기 위해 hybrid image coding 방법을 제안한다. hybrid image coding방법은 luminance data Y을 압축하기 위한 새로운 Adaptive Quantization Coding (AQC)을 제안하고 chrominance data CbCr을 Block Truncation Coding (BTC)방법으로 압축하는 것이다. 시뮬레이션 결과는 기존의 PSNR과 SD의 비교를 통하여 HIC의 우수함을 확인하여 알고리즘의 효율성을 검증하였다. 제안된 알고리즘은 verilog HDL를 통해 구조를 구현하고 synopsys design compiler를 통하여 합성 $0.13{\mu}m$ Samsung Library구조의 효율성을 확인하였다.

  • PDF

The Performance Potential of Data Dependent Computation on Asynchronous Superscalar Processor

  • Kim, Suk-Jin;Park, Byung-Soo;Park, Chan-Ho;Lee, Dong-Ik
    • 대한전자공학회:학술대회논문집
    • /
    • 대한전자공학회 2000년도 ITC-CSCC -1
    • /
    • pp.414-416
    • /
    • 2000
  • We investigate potential advantages and problems when a superscalar processor is designed and implemented using asynchronous design methods. Conventional techniques of superscalar processing are applied and data dependent adder is considered as an asynchronous component. Intensive simulations on SPEC INT95 benchmark suites are made for the purpose of performance comparison between a synchronous and an asynchronous superscalar processor, respectively. The simulation results show about 5% speedup with asynchronous design methods in the sense of Issue Rate.

  • PDF

SmartX-mini Center를 통한 NUC 클러스터의 Big Data 처리 가능성 검증 (Feasibility Verification of Big Data Processing employing SmartX-mini Center with NUC Cluster)

  • 송지원;이준기;김승룡;김종원
    • 한국정보처리학회:학술대회논문집
    • /
    • 한국정보처리학회 2015년도 춘계학술발표대회
    • /
    • pp.73-74
    • /
    • 2015
  • IoT의 발달로 인해 새롭게 빅데이터와 그의 실시간 처리의 중요성이 증대되고 있다. 본 논문에서는 사물인터넷의 관제 및 데이터 처리 기능을 갖춘 SmartX-mini 센터를 통하여 NUC 클러스터의 빅데이터 처리 가능성을 제시하고, 이를 검증하기 위하여 SmartX-mini 테스트베드를 활용한다. SmartX-mini Center의 Spark 프레임워크를 이용한 실험을 통해 IoT 환경에서의 NUC 클러스터의 빅데이터 처리 가능에 대한 가능성을 검증하였다.

Ultra Wide BandWireless Communications : A Tutorial

  • Di Benedetto , Maria-Gabriella;Vojcic, Branimir-R.
    • Journal of Communications and Networks
    • /
    • 제5권4호
    • /
    • pp.290-302
    • /
    • 2003
  • Ultra wide band (UWB) radio has recently attracted increased attention due to its expected unlicensed operation, and potential to provide very high data rates at relatively short ranges. In this article we briefly describe some main candidate multiple access and modulation schemes for UWB communications, followed with their power spectral density calculation and properties. We also present some illustrative capacity results, and provide a discussion of the impact of network topology on multiple access capacity.

Multiple Access Control of RS232C Serial Communications Interface

  • Kyongho Han;Park, Cheon-Won
    • 대한전자공학회:학술대회논문집
    • /
    • 대한전자공학회 2002년도 ITC-CSCC -1
    • /
    • pp.639-641
    • /
    • 2002
  • In this paper, we proposed the multiple access control of RS232C Serial Communications protocol using collision sense method. The communications wires of data transmission and reception are tied together through the buffer each to connect to the multiple communication channels. The hardware interface and control program are designed to build the prototype system and the experimental multiple access communications network is built by multiple PC systems and the transfer completion rate results are shown.

  • PDF

Bayesian Analysis for Multiple Capture-Recapture Models using Reference Priors

  • Younshik;Pongsu
    • Communications for Statistical Applications and Methods
    • /
    • 제7권1호
    • /
    • pp.165-178
    • /
    • 2000
  • Bayesian methods are considered for the multiple caputure-recapture data. Reference priors are developed for such model and sampling-based approach through Gibbs sampler is used for inference from posterior distributions. Furthermore approximate Bayes factors are obtained for model selection between trap and nontrap response models. Finally one methodology is implemented for a capture-recapture model in generated data and real data.

  • PDF

RIS Selection and Energy Efficiency Optimization for Irregular Distributed RIS-assisted Communication Systems

  • Xu Fangmin;Fu Jinzhao;Cao HaiYan;Hu ZhiRui
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • 제17권7호
    • /
    • pp.1823-1840
    • /
    • 2023
  • In order to improve spectral efficiency and reduce power consumption for reconfigurable intelligent surface (RIS) assisted wireless communication systems, a joint design considering irregular RIS topology, RIS on-off switch, power allocation and phase adjustment is investigated in this paper. Firstly, a multi-dimensional variable joint optimization problem is established under multiple constraints, such as the minimum data requirement and power constraints, with the goal of maximizing the system energy efficiency. However, the proposed optimization problem is hard to be resolved due to its property of nonlinear nonconvex integer programming. Then, to tackle this issue, the problem is decomposed into four sub-problems: topology design, phase shift adjustment, power allocation and switch selection. In terms of topology design, Tabu search algorithm is introduced to select the components that play the main role. For RIS switch selection, greedy algorithm is used to turn off the RISs that play the secondary role. Finally, an iterative optimization algorithm with high data-rate and low power consumption is proposed. The simulation results show that the performance of the irregular RIS aided system with topology design and RIS selection is better than that of the fixed topology and the fix number of RISs. In addition, the proposed joint optimization algorithm can effectively improve the data rate and energy efficiency by changing the propagation environment.