• Title/Summary/Keyword: electronic communications

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A study on Economic Effects of Electronic Commerce (전자상거래의 경제적인 효과에 관한 연구)

  • 조원길
    • The Journal of Information Technology
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    • v.1 no.1
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    • pp.155-172
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    • 1998
  • Electronic commerce is more than just handling purchase transactions and funds transfers over the internet. Despite electronic commerce's past roots in transactions between large corporations, banks, and other financial institutions, the use of the internet as a way to bring electronic commerce to the individual consumer has led to a shift in viewpoint. Over the past few years, both the press and the business community have increased their focus on electronic commerce involving the consumer Electronic commerce includes the tasks that support the buying and selling of goods and services, and interactions among those tasks. Electronic commerce enables companies to close stores, reduce inventory requirements, and distribute products over the internet. Electronic commerce can simplify communication and change relationships The economics of electonic commerce is concernec with a new market whose delivery and communication infrastructure happens to be the internet. The economics of electronic commerce focuses on markets whose transactions are facilitated by communications networks and delivery systems. However, any digital communications media will soon be capable of supporting virtual transactions In the electronic marketplace, including telephone wires, cables, microwaves, and satellites. Thus, electronic commerce can offer your company both short-term and long-term befits. moving business practices, such as ordering, invoicing, and consumer support, to network-based systems can also reduce the paperwork involved in business-to-business transactions. This study conducted a study on economic effects of electronic commerce

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Design of Non-Binary Quasi-Cyclic LDPC Codes Based on Multiplicative Groups and Euclidean Geometries

  • Jiang, Xueqin;Lee, Moon-Ho
    • Journal of Communications and Networks
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    • v.12 no.5
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    • pp.406-410
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    • 2010
  • This paper presents an approach to the construction of non-binary quasi-cyclic (QC) low-density parity-check (LDPC) codes based on multiplicative groups over one Galois field GF(q) and Euclidean geometries over another Galois field GF($2^S$). Codes of this class are shown to be regular with girth $6{\leq}g{\leq}18$ and have low densities. Finally, simulation results show that the proposed codes perform very wel with the iterative decoding.

A study on Yeosu area communication history in the old documents II (고문서에 나타난 여수지역 통신역사에 관한 고찰 II)

  • Kim, Chun-Suk
    • The Journal of the Korea institute of electronic communication sciences
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    • v.7 no.5
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    • pp.945-953
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    • 2012
  • Yeosu area from the old historical monuments and artifacts related communications signal station, directions display panels, lighthouse, Geomundo the first submarine cable installation, etc. That appears in old documents and communications of the area should check the history and development of communication in understanding the Yeosu area and communicate the need to identify resources historicity.

Speckle Reduction in the Wavelet Domain for Image with Optical Coherence Tomography

  • Chang, Ju-Wan;Lee, Chang-Su;Na, Ji-Hoon;Paes, Stephane;Lee, Byeong-Ha
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.2459-2463
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    • 2005
  • Optical coherence tomography (OCT) is high resolution medical imaging system which is obtaining image inside biological objects with non-destructive method. OCT system is based on Michelson interferometer with a reciprocating mirror in the reference arm and a biological object in the sample arm. The obtained OCT image suffers from a granular or mottled image, called speckle. Speckle is caused by random interferences between reflected coherence waves. In this paper, we propose effective speckle reduction method that uses wavelet transform. With wavelet domain image, sub-windowing and thresholding are performed. Finally, speckle reduction experiments for Misgurnus mizolepis skin and rat eye images are shown.

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Interference Mitigation Scheme for Device-to-Device MIMO Communications Underlaying a Cellular Network

  • Nam, Yujin;So, Jaewoo;Kim, Jinsung
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.11 no.4
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    • pp.1841-1865
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    • 2017
  • This paper proposes a new interference mitigation scheme for device-to-device (D2D) communications underlaying a cellular network. The object of the proposed scheme is to determine the number of data streams, a precoding matrix, and a decoding matrix of D2D networks so as to maximize the system capacity given the number of data streams of a cellular network while satisfying the constraint of the inter-system interference from D2D networks to the cellular network. Unlike existing interference mitigation schemes based on the interference alignment technique, the proposed scheme operates properly regardless of the number of data streams of a cellular network and moreover it does not require changing the precoding and decoding matrices of a cellular network. The simulation results demonstrate that the proposed scheme significantly increases the system capacity by mitigating the intra- and inter-system interference.

An All-Optical Gain-Controlled Amplifier for Bidirectional Transmission

  • Choi, Bo-Hun;Hong, Kyung-Jin;Kim, Chang-Bong;Won, Yong-Hyub
    • ETRI Journal
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    • v.28 no.1
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    • pp.1-8
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    • 2006
  • A novel all-optical gain-controlled (AOGC) bidirectional amplifier is proposed and demonstrated in a compact structure. The AOGC function using fiber Bragg grating (FBG) pairs controls both directional signals independently, and combinations of optical interleavers and isolators suppress Rayleigh backscattering (RB) noise. The amplifier achieves high and constant gain with a wide dynamic input signal range and low noise figure. The performance does not depend on the input signal conditions, whether static-state or transient signals, or whether there is symmetric or asymmetric data traffic on bidirectional transmission. Transmission comparison experiments between invariable symmetrical and random variable asymmetric bidirectional data traffic verify that the all-optical gain control and bidirectional amplification functions are successfully combined into this proposed amplifier.

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Measurement of Radio Characteristics of Vehicular Communication Environments in Urban Areas and Implementation Issues (도심 차량통신환경에서의 전파특성 측정과 구현 이슈)

  • Cho, Woong
    • The Journal of the Korea institute of electronic communication sciences
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    • v.9 no.9
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    • pp.1057-1062
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    • 2014
  • Vehicular communications can be applied for transmission of various safety messages or Intelligent Transportation Systems(ITS) applications by combining vehicle/road technology with Information and Communication Technology(ICT). In this paper, we represent measurement results of radio characteristics of vehicular communications using IEEE 802.11p based system in urban environments. Radio characteristics are based on the packet error rate (PER) and received spectrum mask. Using measurement results, we discuss implementation issues of vehicular communication systems for supporting reliable services.

Internet Traffic Analysis for Efficient Access Network Design (인터넷 액세스망의 효율적 구성을 위한 어플리케이션별 특성 분석)

  • Kim, Woo-Hyun;Do, Jin-Sook;Lee, Kyung-Geun;Park, Hyeong-Koo;Jang, Ju-Wook;Yang, Won-Suk
    • Proceedings of the Korea Information Processing Society Conference
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    • 2000.10b
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    • pp.1005-1008
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    • 2000
  • 인터넷 액세스망을 효과적으로 구축하기 위하여 급격히 확산되는 인터넷 트래픽을 수용할 기반 구축의 방법이 최근 주요 과제로 부상하고 있다. 기존의 엑세스망 설계는 전체 인터넷 트래픽 특성에 대한 가정으로부터 모델링을 하였으나 본질적으로는 특정 어플리케이션에 중점을 둔 결과를 보였다. 일반적으로 요즘에는 어플리케이션의 종류도 다양해졌고 트래픽의 양도 비약적으로 증가하였다. 그래서 이러한 설계방식은 다양한 어플리케이션를 제공하는 인터넷에서는 효율적인 엑세스망 설계를 저해하는 요인이 될 수가 있다. 본 논문에서는 계속적으로 증가하는 어플리케이션을 중심으로 어플리케이션에 따라 달라지는 트래픽의 통계적 특성을 조사하여 분류하고 설계에 필요한 요소들을 도출하고자 한다.

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A study on Yeosu area communication history in the old documents I (고문서에 나타난 여수지역 통신역사에 관한 고찰 I)

  • Kim, Chun-Suk
    • The Journal of the Korea institute of electronic communication sciences
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    • v.6 no.5
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    • pp.603-610
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    • 2011
  • Yeosu area from the old historical monuments and artifacts related communications signal station, directions display panels, lighthouse, Geomundo the first submarine cable installation, etc. That appears in old documents and communications of the area should check the history and development of communication in understanding the Yeosu area and communicate the need to identify resources historicity.

Resource Discovery on the Semantic Web (Semantic Web 환경에서의 자원발견)

  • Park, Jae-Hong;Lim, You-Jeong;Kim, Do-Wan;Park, Chan-Kyu;Cho, Hyun-Kyu
    • Proceedings of the Korea Information Processing Society Conference
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    • 2002.11a
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    • pp.817-820
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    • 2002
  • Semantic Web 환경의 등장 배경과 Semantic Web을 구성하는 구성요소 및 기술분석에 대해 살펴볼 것이며 이를 바탕으로 제주도의 숙박, 항공, 렌트카 정보 온톨로지 구축과 Jena 에서 지원하는 RDQL 을 이용하여 사용자가 원하는 서비스 자원 발견을 수행할 수 있는 프로타이프 테스트 베드 구축에 대해 살펴볼 것이다.

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