• Title/Summary/Keyword: burst

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Feed-Forward Control of Transient Gain Dynamics of an EDFA for Optical Burst Networks

  • Cho, Jeong-Sik;Cho, Min-Jae;Won, Yong-Hyub
    • ETRI Journal
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    • v.29 no.5
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    • pp.679-681
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    • 2007
  • In this letter, we demonstrate a technique for suppression of transients in output bursts of an erbium-doped fiber amplifier (EDFA) in an optical burst network. To suppress the transients, the EDFA is forward-fed by non-fluctuating input utilizing a power-modulated burst control packet channel. Using the technique, we obtained a maximum 1.7 dB reduction in gain transient in the EDFA output, and we transmitted 9.953 Gbps data bursts and 2.488 Gbps burst control packets stably.

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Efficient Utilization of Burst Data Transfers of DMA (직접 메모리 접근 장치에서 버스트 데이터 전송 기능의 효과적인 활용)

  • Lee, Jongwon;Cho, Doosan;Paek, Yunheung
    • IEMEK Journal of Embedded Systems and Applications
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    • v.8 no.5
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    • pp.255-264
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    • 2013
  • Resolving of memory access latency is one of the most important problems in modern embedded system design. Recently, tons of studies are presented to reduce and hide the access latency. Burst/page data transfer modes are representative hardware techniques for achieving such purpose. The burst data transfer capability offers an average access time reduction of more than 65 percent for an eight-word sequential transfer. However, solution of utilizing such burst data transfer to improve memory performance has not been accomplished at commercial level. Therefore, this paper presents a new technique that provides the maximum utilization of burst transfer for memory accesses with local variables in code by reorganizing variables placement.

Development of Optical Burst Switching System for Next Generation Internet Services (차세대 인터넷 서비스를 위한 광버스트 교환 노드 설계)

  • Jang, Hee-Seon;Shin, Hyeun-Cheul;Aum, Ki-Chul;Lee, Sung-Hoon
    • Convergence Security Journal
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    • v.5 no.1
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    • pp.45-52
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    • 2005
  • In this paper, the development specification of the optical burst switching system (OBS) for next generation internet services is presented. The development specification includes the number of input/output nodes, the number of wavelengths, buffer capacity, the capacity/queue size of the controller and maximum burst assembly delay. From the performance parameters related to the OBS design, an mathematical model to maximize the throughput and minimize the data loss is presented, and then efficient heuristic algorithm is also presented to analyze the sensitivity of the system parameters.

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The Performance evaluation of the Reed-Solomon Product Codes in Burst Error (Burst Error Channel에서 Reed-Solomon Product 코드의 에러 정정 평가 방법)

  • Han, Sung-Hyu;Lee, Yoon-Woo;Hwang, Sung-Hee;Ryu, Sang-Hyun;Shin, Dong-Ho;Joong-Eor, Joong-Eor
    • Proceedings of the KIEE Conference
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    • 2001.07d
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    • pp.2493-2495
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    • 2001
  • Burst Error Channel의 에러 정정 기술로써 Reed-Solomon Product Code(RSPC)가 광범위하게 사용되고 있다. 그러나 Random Error Channel과는 달리 Burst Error Channel 상에서 RSPC의 에러 정정 평가 방법에는 많은 어려움이 있다. 우리는 이번 논문에서 Burst Error Channel 상에서 RSPC의 Error Correction Capability의 확률적인 계산 방법을 기술하려 한다.

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An Integrated QoS Support Architecture of Wireless LAN based Home Network for Multimedia Services (무선랜 기반의 홈 네트워크환경에서의 멀티미디어 서비스를 위한 통합적인 QoS 제공 구조)

  • Shin, Myung-Sik;Yang, Hae-Sool
    • Journal of The Institute of Information and Telecommunication Facilities Engineering
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    • v.9 no.1
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    • pp.7-12
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    • 2010
  • In this paper, we propose a new prioritized Optical Burst Switching (OBS) protocol based on a hop count, which can provide an efficient utilization in optical Wireless networks. Under several legacy schemes, a switch drops the burst with a shorter time among ones regardless of its traversed hop counts. As a result, the dropped burst that have been traversed more hops might cause to waste bandwidth than the one traversed a few hops. Noting that this problem, we propose the Just Enough Time (JET) with a hop count scheme which can reduce the wasted bandwidth by prioritizing the burst traversed more hops over others. From the simulation result, we show that the proposed scheme is advantageous over the legacy schemes in terms of the burst blocking probability and the link utilization.

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A Study on a New Carrier Recovery Algorithm for Coherent Burst-mode Communication Systems (동기식 버스트 통신시스템 적용을 위한 새로운 반송파 동기 기법에 관한 연구)

  • Park, Sung-Bok
    • Journal of the Korea Institute of Military Science and Technology
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    • v.14 no.6
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    • pp.1043-1048
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    • 2011
  • In this paper, a newsynchronization technique applied to burst-mode communication is proposed. A synchronization technique is to estimate carrier frequency and phase offsets in a noisy channel environment. A fundamental problem for estimating the parameters(carrier phase and frequency offsets) in burst-mode transmission is that the ways of pursuing estimation accuracy and transmission efficiency are always trade-off. To solve this problem, a new carrier recovery technique is proposed to improve the transmission efficiency with reliable performance especially at low S/N. In the proposed technique, the synchronization parameters are first estimated based on a data-aided feed-forward estimation scheme. Then, a phase tracker using decision-directed DPLL estimates the phase offset for the data portion of the burst data. From simulation results, it shows fast synchronization with shorter preamble maintaining reasonable BER performance at low S/N.

Burst pressure estimation of Alloy 690 axial cracked steam generator U-bend tubes using finite element damage analysis

  • Kim, Ji-Seok;Kim, Yun-Jae;Lee, Myeong-Woo;Jeon, Jun-Young;Kim, Jong-Sung
    • Nuclear Engineering and Technology
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    • v.53 no.2
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    • pp.666-676
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    • 2021
  • This paper presents numerical estimation of burst pressures of axial cracked U-bend tubes, considering the U-bending process analysis. The validity of the FE simulations is confirmed by comparing with published experimental data. From parametric analyses, it is shown that existing EPRI burst pressure estimation equations for straight tubes can be conservatively used to estimate burst pressures of the U-bend tubes. This is due to the increase in yield strength during the U-bending process. The degree of conservatism would decrease with increasing the bend radius and with increasing the crack depth.

Case study of Oriental Medicine Treatment with Mae-sun therapy of the spinal cord injury due to lumbar burst fracture (방출성 요추 골절로 인한 척수손상 환자에 대해 매선요법을 가미한 한방치료를 시행한 치험례)

  • Kwon, Gi-Sun;Park, Jung-Ah;Noh, Ju-Hwan;Kim, Cheol-Hong
    • Journal of Pharmacopuncture
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    • v.13 no.1
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    • pp.129-144
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    • 2010
  • Objective : Traumatic lumbar burst fracture causes significant spinal cord injury. This report is intended to estimate the efficacy using oriental treatment on a patient with lumbar burst fracture and spinal cord injury. Methods : From 21th December, 2009 to 5th February, 2010, 1 female inpatient diagnosed with lumbar burst fracture and spinal cord injury was treated with general oriental medicine therapy : mae-sun therapy ; acupuncture ; moxibustion ; pharmacopuncture ; physical therapy and herbal medication. TUG, SCIMII and VAS were used for evaluation of gait disturbance and pain in both feet. Measurement of self voiding amount and remaining amount through CIC was used for evaluation of neurogenic vesical dysfunction. Results : The patient showed a certain degree of improvement in gait disturbance, pain in both feet and neurogenic vesical dysfunction through above evaluation methods. Conclusion : Oriental treatments such as mae-sun therapy, acupuncture and moxibustion therapy, pharmacopuncture therapy and herbal medication can be effective for spinal cord injury due to traumatic lumbar burst fracture.

Analysis of the Effect on Offset Time under Fault and Propose a New Restoration Scheme Considering QoS in OBS Networks (광 버스트 스위칭 망에서 망 고장에 대한 offset 시간 영향 분석 및 QoS를 고려한 장애 복구 기법)

  • 이해정;송규엽;소원호;김영천
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.40 no.12
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    • pp.94-105
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    • 2003
  • OBS(Optical Burst Switching) networks which decouple the burst from its header has characteristic one-way reservation. Therefore, the fault of a fiber link may lead to the magnitude of burst loss. Since sending a header packet and using an offset time before the transmission of the corresponding burst. In this paper, we analysis a offset time based on the burst loss rate resulting from only link failure and by applying the restoration schemes in an optical burst switching networks. The simulation results in terms of the effect of a offset time is evaluated in our network model to verify that comparing the numerical analysis with simulation result. Finally, and through these results, We propose the new restoration scheme based on offset time considered Quality of Service.

A Study on the development of a burst-mode optical transceiver for optical access networks (광 가입자망을 위한 버스트 모드 광 송수신기 개발에 관한 연구)

  • Lee, Hyuek-Jae
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.9 no.6
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    • pp.1346-1355
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    • 2005
  • Recently, the development of passive optical networks (PON) for FTTH (Fiber-To-The-Home) have been actively conducted. In PON, a burst-mode transceiver is one of key modules. In this paper, we have made the protype module of a 155.52 Mpbs optical burst-mode transceiver with commercially available chips and then have measured the performance. Also, a new method of burst-mode clock recovery have been proposed. The burst-mode clock recovery implemented by using CPLD(Complex Programmable Logic Device) has coupled with the above burst-mode transceiver and has been tasted.