• Title/Summary/Keyword: 고신뢰성 전송

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Stereo Video Delivery System for Enhanced Immersion (실감성 증진을 위한 스테레오 비디오 전송 시스템)

  • 장혜영;오세찬;김종원;우운택;변옥환
    • Journal of KIISE:Computing Practices and Letters
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    • v.9 no.6
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    • pp.602-609
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    • 2003
  • Emerging high-speed next-generation Internet is enabling immersive media communication systems and applications to realize geographically distributed team collaborations while overcoming the limit of distance and time. Focusing on the reliable real-time delivery of 3D (i.e., stereo) video among corresponding parties, in this paper, key schemes for stereo video processing/display and reliable transport of stereo video packets over high-speed Internet are designed and implemented. The performance of proposed stereo video delivery system is evaluated both by emulating various network situations for quantitative comparison and by transmitting over real-world Internet up to the speed of around 100 Mbps. The results demonstrate the feasibility of the proposed system in supporting the desired immersive communication.

A research on performance improvement and QoS application method for File Transfer (파일 전송 시 성능향상 및 QoS 적용방법 연구)

  • 김국한;이만희;변옥환;유인태
    • Proceedings of the Korean Information Science Society Conference
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    • 2002.10e
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    • pp.157-159
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    • 2002
  • 슈퍼컴퓨터 사용자들은 FTP(File Transfer Protocol)을 이용해서 파일을 전송한다. 전송되는 데이터들은 여러 분야에 걸친 연구관련 자료로서 고성능 슈퍼컴퓨터에 의한 연산 처리가 요구되며 그 결과들은 연구결과에 많은 영향을 준다. 사용자들의 연구 데이터가 담긴 대용량 파일의 전송할 때 성능향상 방법을 적용하고 네트워크 상태에 따라 QoS(Quality of Service)를 할당한다면 데이터의 손실률을 최소화하고 신뢰성 있는 네트워크 상태로 인하여 사용자들은 연산처리 결과가 더욱 정확하다고 신뢰할 수 있다. 본 고에서는 대용량 파일을 전송 할 때 성능을 향상시키는 방법과 QoS 적용 방법을 알아본다.

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Reliable Ethernet-based Network for Railway Signaling Systems (철도신호시스템에서 고신뢰성을 갖는 이더넷 기반 네트워크)

  • Jo, Hyun-Jeong;Hwang, Jong-Gyu;Lee, Kang-Mi;Lee, Jae-Ho
    • Proceedings of the KIEE Conference
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    • 2006.04b
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    • pp.293-295
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    • 2006
  • 철도 신호제어시스템은 철도의 선로변에 위치하면서 열차의 안전운행을 책임지는 매우 중대한 시스템이다. 이러한 신호제어장치들은 각자의 고유의 기능을 수행하면서 다른 제어장치들과 링크되어 하나의 신호제어시스템으로 구성되어진다. 요즘 철도신호시스템에 사용되는 각 장치들이 전자화되어감에 따라 철도신호장치들간 정보전송을 위한 네트워크에 대한 중요성이 증대되었다. 철도신호시스템과 같은 고신뢰성이 요구되는 시스템에서 실시간 요구조건과 신뢰도를 만족시킬 수 있는 네트워크 기술에 대한 필요성 또한 증대되고 있다. 가장 널리 쓰이는 기술인 이더넷은 프로토콜 자체의 랜덤 특성으로 인해 실시간 요구사항을 만족하지 못하였으나 최근 들어 스위치드 이더넷으로 진화하면서 산업용 제어시스템에 이더넷 기술이 적용되고 있다. 본 논문에서는 이러한 스위치드 이더넷의 이론적 해석을 통해 철도신호시스템에 적용 가능성을 확인하였고, 네트워크에 결함발생 시 결함검지 및 회복 알고리즘이 포함된 높은 신뢰성을 가진 이더넷 기반 네트워크 알고리즘과 모의시험을 통한 그 성능을 분석하였다.

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A Message Priority-based TCP Transmission Algorithm for Drone Systems (드론 시스템을 위한 메시지 우선순위 기반 TCP 통신 알고리즘)

  • Choi, Joon-Hyuck;Kim, Bo-Ram;Lee, Dong-Ik
    • The Journal of the Korea institute of electronic communication sciences
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    • v.13 no.3
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    • pp.509-516
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    • 2018
  • TCP is a well-known communication protocol which is widely used for reliable message transmissions. The urgent mechanism of TCP plays a key role to transmit messages with a high priority. If a high priority message occurs at the transmitting node, the urgent mechanism informs the receiving node about the presence of a high priority message prior to its transmission so that the receiving node can be prepared for handling this message in advance. This implies that the existing urgent mechanism of TCP does not guarantee an immediate or faster delivery of the high priority message itself. Therefore, the ability of priority-based transmission is required on TCP not only to ensure reliable transmissions of normal messages but also to offer a differentiated service according to the priority of message. This paper presents a priority-based transmission algorithm over TCP using a priority queue in a multi-threaded environment. The effectiveness of the proposed algorithm is explored using an experimental setup in which various messages with different priority levels are transmitted.

CR을 위한 OFDMA 기반 적응 전송 방식

  • Kim Yun-Hui;Kim Gwang-Sun
    • The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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    • v.17 no.2 s.58
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    • pp.9-18
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    • 2006
  • CR은 사용자 환경의 실시간 조건에 따라 무선 파형을 적응시킴으로써 주파수 스펙트럼을 유연하고, 효율적이며, 신뢰성 있게 활용하는 지능적인 무선통신 방식을 의미한다. 한편, 무선 채널의 다양한 특성에 따라 시간 및 주파수 영역에서 자원의 동적 할당이 가능한 OFDMA 방식은 CR 시스템에 잘 부합되는 방식이라 할 수 있다. 본 고에서는 무선 환경에서 주파수 효율을 증대시키기 위해 OFDMA 기반 적응 전송 방식의 기술 동향을 살펴보고, 사용자 환경에 좀 더 지능적으로 대처하는 CR 시스템을 구현하기 위한 재구성 가능한 OFDMA 전송 플랫폼을 소개한다.

Reliable Measurement and Analysis System for Ubiquitous Healthcare (고신뢰 유비쿼터스 헬스케어 데이터 측정 및 분석 시스템)

  • Jung, Sang-Joong;Seo, Yong-Su;Kim, Jong-Jin;Chung, Wan-Young
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2009.05a
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    • pp.293-297
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    • 2009
  • This paper describes a real-time reliable measurement and analysis system for ubiquitous healthcare based on IEEE802.15.4 standard. In order to obtain and monitor physiological body signals continuously, wearable pulse oximeter is designed in wrist that could used to measure oxygen saturation of a patient unobtrusively. The measured data was transferred to a central PC or server by using wireless sensor nodes via a wireless sensor network for storage and analysis purposes. LabVIEW server program was designed to monitor and process the measured photoplethysmogram(PPG) to accelerated plethysmogram(APG) by appling second order derivatives in server PC. These experimental results demonstrate that APG can precisely describe the features of an individual's PPG and be used as estimation of vascular elasticity for blood circulation.

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Reliable Transmission Using Intermediate Relay Node-based Transmission for Reliability in Sensor Network (센서 네트워크의 고 신뢰성을 위한 중계 노드 기반 전송)

  • Lee Bo-Hyung;Yoon Hyung-Wook;Park Jongho;Chung Min Young;Lee Tea-Jin
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.30 no.9A
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    • pp.850-857
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    • 2005
  • Sensor networks consist of sensor nodes with small size, low cost, lowpower consumption, and multi-functions to sense, to process and to communicate. The main issue in sensor networks has been focused on minimizing power consumption of sensors to maximize network life time. In some critical applications, however, the most important issue is to transmitsensing information to the end user (the sink node) with reliability. Reliable information forwarding using multiple paths in sensor networks (ReinForM) has been proposed to achieve desired reliability in the error-prone channel, but it needs increasing transmission riverhead as the channel error rate becomes high and the number of hops between the source node and the sink node increases. In this paper, we propose a reliable transmission rnechanissmusing intermediate source nodes in sensor networks (ReTrust) to reduce packet overhead while keeping the desired reliability. ReTrust has beenshown to provide desired reliability and reduced overhead via simulationsand analysis.

Wireless Data Transmission Algorithm Using Cyclic Redundancy Check and High Frequency of Audible Range (가청 주파수 영역의 고주파와 순환 중복 검사를 이용한 무선 데이터 전송 알고리즘)

  • Chung, Myoungbeom
    • KIPS Transactions on Computer and Communication Systems
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    • v.4 no.9
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    • pp.321-326
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    • 2015
  • In this paper, we proposed an algorithm which could transmit reliable data between smart devices by using inaudible high frequency of audible frequency range and cyclic redundancy check method. The proposed method uses 18 kHz~22 kHz as high frequency which inner speaker of smart device can make a sound in audible frequency range (20 Hz~22 kHz). To increase transmission quantity of data, we send mixed various frequencies at high frequency range 1 (18.0 kHz~21.2 kHz). At the same time, to increase accuracy of transmission data, we send some mixed frequencies at high frequency range 2 (21.2 kHz~22.0 kHz) as checksum. We did experiments about data transmission between smart devices by using the proposed method to confirm data transmission speed and accuracy of the proposed method. From the experiments, we showed that the proposed method could transmit 32 bits data in 235 ms, the transmission success rate was 99.47%, and error detection by using cyclic redundancy check was 0.53%. Therefore, the proposed method will be a useful for wireless transmission technology between smart devices.

Adapt ive Iteration Decoding Preset Method of LDPC Codes by SNR Estimation & Decoder Structure (LDPC 부호의 적응적 반복 복호수 설정 방식 및 복호기 구조)

  • 이정훈;장진수;정영일;이문호
    • Proceedings of the IEEK Conference
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    • 2001.09a
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    • pp.773-776
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    • 2001
  • 열악한 전송 환경에서 고품질, 고신뢰성 통신을 지속적으로 하기 위해서 오류 정정 부호는 필수 적이다. 최근에 반복 복호를 통해 샤논의 채널 용량 한계에 근접하는 터보 부호와 LDPC부호가 가장 관심을 불러일으키고 있다. 반복 복호법은 성능 면에서는 우수해 지나 이에 따른 계산량 증가와 지연이 수반된다. 따라서 본 논문에서는 모의 실험을 통한 수신 데이터를 이용, SNR을 추정하여 LDPC 부호의 최대 반복 복호수에 따른 계산량과 지연을 효과적으로 줄일 수 있는 적응적 반복 복호수 설정 방식을 제안한다.

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An Architecture and Experimentation for Efficient and Reliable Name Service Systems (효율적이고 신뢰성 있는 네임 서비스 시스템의 구조 및 실험)

  • 심영철;박준철;강호석;이준원
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.29 no.3B
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    • pp.375-390
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    • 2004
  • Domain Name System(DNS), one of the most important Internet services, handles mapping from host names to Internet addresses and vice versa, and precedes many Internet applications such as Web, e-mail, file transfer, etc. In this paper, we propose a structural design of a generic name server system providing name services for a huge domain for the purpose of improving the performance as well as the reliability of the system. We demonstrate the validity of the design by implementing and running a testbed system. Our testbed employs a couple of master name sowers for distributing the service overhead over two, rather than one, servers and for achieving high availability of the system as a whole. We suggest the use of dynamic update to add and delete records from a zone for which the name server has authority. The slave name servers located remotely then get a new, updated copy of the zone via incremental zone transfers(IXFRs). The experiments with the implemented testbed show that the proposed structure would easily manage increasing demands on the server power, and be highly available in the face of transient faults of a module in the system.