• Title/Summary/Keyword: Burst

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Performance Evaluation of LDPC-LDPC Product Code for next Magnetic Recording Channel (차세대 자기기록 채널을 위한 LDPC-LDPC 곱 부호의 성능 평가)

  • Park, Donghyuk;Lee, Jaejin
    • Journal of the Institute of Electronics and Information Engineers
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    • v.49 no.11
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    • pp.3-8
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    • 2012
  • Two-dimensional product code has been studied for correcting burst errors on the storage systems. An RS-LDPC product code consists of an RS code in horizontal direction and an LDPC code in vertical direction. First, we detect the position of burst errors by using RS code, then LDPC code corrects the errors by using the burst error positions. In storage system, long burst errors are occurred by various reason. So, we need a strong code for correcting the long burst errors. RS-LDPC product code is good for long burst errors. However, as the storage density grows the length of the burst errors will be longer. Thus, we propose an LDPC-LDPC product code, it is strong for correcting the very long burst errors. Also, the proposed LDPC-LDPC product code performs better than RS-LDPC product code when the random errors are occurred, because a row direction LDPC code performs better than row direction RS code.

An Empirical Study on the Designed Burst Pressure of Type3 Composite Cylinder (Type3 복합용기 설계 파열압에 관한 실증연구)

  • Kim, ChangJong;Cho, Sung Min;Kim, Eun Jung;Yoon, Kee Bong
    • Journal of the Korean Institute of Gas
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    • v.17 no.3
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    • pp.20-26
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    • 2013
  • In this research, an empirical study on the designed burst pressure of Type3 composite cylinder was performed by hydrostatic burst test equipment. The designed burst pressure of Type3 composite cylinders, which are 6.8 liter and 31 MPa of service pressure, was estimated with the analysis using the finite element method. In order to confirm its accuracy, the burst test of small Type3 composite cylinders was perfomed through three times. The burst test equipment can pressurize to 400 MPa. As a result of comparison between the designed burst pressure and actual burst pressure, the difference was less than 4 percentage. With a test result, the analysis accuracy was verified. This technique will be applied to both qualification and inspection for the composite cylinder.

A New CDMA Uplink Channel Structure and DBCE Detection Scheme Using Staggered Burst Pilot (CDMA Uplink 채널 구조와 Staggered Burst 파일럿을 이용한 DBCE 검출기법)

  • 나종래
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.25 no.9A
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    • pp.1359-1367
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    • 2000
  • A new coherent detection scheme with data based channel estimation (DBCE) for CDMA/BP(staggered burst pilot in parallel) channel structure is proposed. Because the pilot burst initiates DBCE operation periodically it is shown to be remarkably stable to Gaussian noise and Doppler shift with proper parameter settings. In our own system parameter setting, there is a negligible loss(0.068 dB) in $E_{b}/N_{o}$ by the introduction of the burst pilot. When compared with an ideal coherent detection, the required $E_{b}/N_{o}$ on Doppler shift corresponding to the speed of 160Km/H is degraded less that 2.0 dB. the burst pilot can be implemented without complexity even though some extra correlators are needed for DBCE. This improvement is superior to the previously coherent CDMA detectors with external or internal pilot.

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Buffer-based Service Differentiation Scheme in Optical Burst Switching Networks (광 버스트 스위칭 네트워크에서 버퍼 기반의 서비스 차별화 방식)

  • Paik, Jung-Hoon;Lee, Kyou-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.17 no.12
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    • pp.2835-2842
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    • 2013
  • In this paper, service differentiation scheme using optical buffer that is reduced in size with slow-light technology in optical burst switching networks is presented. In suggested scheme, each outport has buffer to store high-class burst only in case that all its wavelengths are occupied. When all wavelengths are being used, a new arriving high-class burst goes into the buffer and waits until a burst is serviced. As soon as a burst is serviced with a wavelength, the high-class burst at buffer is allocated to the free wavelength. In case that low-class burst is arriving under the same situation, it is not stored at the buffer but discarded. An analytical model is derived to analyze the performance of the suggested scheme and compare its performance with the conventional scheme such as preemption and deflection as well as no service differentiations.

Analysis of Pipe-Burst effect in Water Distribution Network (상수관망의 관로파열 영향 해석)

  • Park, Jae-Hong
    • Journal of Korea Water Resources Association
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    • v.35 no.6
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    • pp.665-675
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    • 2002
  • It is very closely related with the reliability of the pipe network to predict pipe burst and diminish burst effect in water distribution system. Most of the engineers have not consider pipe layout and the effect of pipe burst in conservative pipe network design. In this study, The effect of pipe burst in the network is analyzed with respect to pipe network geometric topology and the method of increasing the system reliability is presented by reducing pipe-burst effect. In existing pipe system, it is only designed to the closed loop system but in case of each pipe burst, it cannot transmit appropriate water to consumers and occurs severe hydraulic head drop in many nodes. The techniques developed in this study allow proper pipe diameter and pipe layout to pipe system through the analysis of pipe-burst effect. Thus, when each pipe is bursted, pipe system is prevented from severe pressure head drop in demand nodes and can supply stable flowrate to consumer.

An Analysis on the Burst Assembly Schemes in the Optical Burst Switched Networks. (광 버스트 스위칭 네트워크에서의 버스트 어셈블리의 성능 비교 및 분석)

  • Park Dong-Hee;Yoo Myungsik
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.29 no.1B
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    • pp.109-116
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    • 2004
  • Optical Burst Switching (OBS) technology has drawn much attention as a promising solution for IP/WDM networks. OBS has the features such as the offset time, the delayed reservation and the burst assembly. In particular, the burst assembly, which assembles IP packets into the data bursts, has a great impact on the performance of OBS network. In this paper, we compare the performance of three different burst assembly schemes and investigate their impact on the performance of OBS network.

Performance Evaluation focused on Burst of Smoothing Algorithms (스무딩 알고리즘들의 버스트 성능 평가)

  • Lee, Myoun-Jae
    • Journal of Digital Contents Society
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    • v.13 no.1
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    • pp.111-118
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    • 2012
  • The burst is to require abruptly high transmission rate in case of transmitting pre-stored variable bit rate video data, and it causes to be inefficient use of network resource, resource reservation. To avoid these problems, smoothing is transmission plan where variable rate video data is converted to a constant bit rate stream. These smoothing algorithms include CBA, MCBA, MVBA and others. To evaluate amount of burst reduction in the existing CBA, MCBA, MVBA algorithm, this paper compares the burst-related-factors of transmission plan in smoothing algorithms with original video sources which were stored Variable Bit Rate. There are maximum frame bytes, maximum GOP bytes, transmission rate variability per frame, transmission rate variability per GOP in burst-related evaluation factors. Experimental result shows burst-related factors of smoothing algorithms which were used for experiment lower than that of pre-stored video data, except special case.

Minimum Bandwidth Guarantee for Optical Burst Switching Networks (광 버스트 스위칭망에서 최소 대역폭 보장)

  • 오승훈;김영한
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.40 no.10
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    • pp.59-66
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    • 2003
  • We propose the novel optical burst switching scheme to guarantee a minimum bandwidth for multiple classes. To date, QoS studies on OBS network are capable of differentiating two classes, but have difficulties in providing a minimum bandwidth lot several classes because of lower classes' collision with the highest class bursts in the networks. To solve that problem, in our proposed scheme we assign time zones in a data channel for each class periodically, making one burst have top priority at least its zone. Also, the new burst assembling algorithm, as well as the way of managing data channel, is necessarily proposed to coordinate with the proposed OBS scheme. Through the evaluation, we show that the worst-case end-to-end delay is small enough and the received bandwidth of the lower classes is still assured regardless of the traffic load of the highest class.

Group Scheduling for Efficient Channel Utilization in Optical Burst Switched Networks (OBS 네트워크의 효율적 채널 이용을 위한 그룹 스케줄링 방식)

  • 신종덕
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.40 no.10
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    • pp.51-58
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    • 2003
  • In this paper, we propose a group scheduling scheme to efficiently utilize network resources for core nodes in optical burst switching networks. This scheme schedules multiple bursts utilizing an interval graph to obtain the maximum stable set using the information such as arrival times and burst lengths from the collected header packets. Simultaneous scheduling of multiple bursts in a scheduling window results in lower burst loss probability and increased channel utilization than those proposed previously using one-to-one mapping. Simulation results for both cases of variable and fixed burst sizes show that the group scheduling scheme is better than the immediate scheduling, so called Latest Available Unused Channel with Void Filling, scheme in both performance metrics above mentioned.

Moxifloxacin Alleviates Oleic Acid-provoked Neutrophilic Respiratory Burst in the Rat Lung through the Inhibition of Cytosolic Phospholipase $A_2$ (Moxifloxacin의 Cytosolic Phospholipase $A_2$ 억제효과가 흰 쥐 호중구의 Respiratory Burst에 미치는 영향)

  • Lee, Young-Man
    • Tuberculosis and Respiratory Diseases
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    • v.69 no.4
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    • pp.256-264
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    • 2010
  • Background: According to the notion of the immunoregulatory functions of moxifloxacin (MFX), the effect of MFX on the neutrophilic respiratory burst in conjunction with the expression of cytosolic phospholipase $A_2$ ($cPLA_2$) was investigated. Methods: The effects and possible mechanisms of MFX on neutrophilic respiratory burst in oleic acid (OA)-induced acutely injured rats lung and OA-stimulated, isolated murine neutrophils were probed, associated with the expression of cytosolic phospholipase $A_2$ in vivo and in vitro. Results: In the OA-induced acutely-injured lungs, neutrophils were accumulated, which was attenuated by MFX. The parameters denoting a neutrophilic respiratory burst, such as nitro blue tetrazolium reaction, cytochrome-c reduction, neutrophil aggregation, $H_2O_2$ production in neutrophils revealed increased neutrophilic respiratory burst by OA, and MFX decreased all of these parameters. In addition, the enhanced expression of $cPLA_2$ in the lung and isolated murine neutrophils by OA were decreased by MFX. Conclusion: MFX suppresses the OA-induced neutrophilic respiratory burst by the suppression of $cPLA_2$ in neutrophils.