• Title/Summary/Keyword: AbrB

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An ABR flow control algorithm considering propagation delay (ATM 망에서 전파 지연을 고려한 ABR 흐름 제어)

  • 박기현;김승천;김동연;이재용;이상배
    • Journal of the Korean Institute of Telematics and Electronics S
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    • v.35S no.5
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    • pp.17-26
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    • 1998
  • B-ISDN has many advantages to provide multimedia, image transfer, etc. Recently, ABR service has been proposed in order to satisfy user's various requirements in it. In this paper, we propose a new ABR flow control algorithm called CAPRO. This algorithm uses the buffer proportional to propagation delay and controls the traffic on a link-by-link basis in order to minimize the effect of propagation delay. In order to use buffer more efficienctly, we define the request cell and the control cell. Then, we analyze our algorithm using mathematical model, simulate it using SLAM system, and compare to the existing EPRCA. As a result, our algorithm has the benifit of the throughput, cell loss probability, and fairness.

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A Study on the ABR Traffic Control Mechanism using Dynamic Bandwidth Allocation (동적 대역폭 할당을 이용한 ABR 트래픽 제어 방식에 관한 연구)

  • 류호용;박권철;박광채
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.24 no.12B
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    • pp.2275-2282
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    • 1999
  • In ATM networks, bandwidth allocation using available bandwidth is important to control ABR traffic efficiently. However, it is difficult to dynamically assign bandwidth on bursty traffic, because the tracking of the existing available bandwidth information uses statistical value. In this paper, we propose a output-bufferd ATM switch using Per-VC queueing scheme with timer and Controller. The controller determines whether each VC is in congestion state or not, and the timer can assign dynamically as determining the available bandwidth for the Present period by Backlogged time and total link capacity, and then transmitting the determined bandwidth to source. Instead of using statistical parameters, the proposed scheme can improve link efficiency as allocating the bandwidth of the next period, by use of measured bandwidth during the current period.

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Performance improvement of TCP over ATM using RM cell information (RM 셀 정보를 이용한 TCP over ATM의 성능개선)

  • 최진혁;정재일
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.25 no.3B
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    • pp.487-492
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    • 2000
  • The ABR(available bit rate) service has been developed to support data application over ATM(asynchronous Transfer mode) networks, and TCP is the most widely used transport layer protocol in existing data networks. Thus, the performance improvement of TCP over ABR is an issue of cardinal importance. In this paper, we propose algorithm of the adjustment of congestion window size utilizing RM(resource Management) cell information. The motivation is to use more reliable information in ER(explicit rate) field within RM cell to determine TCP window size. Simulations are performance using the suggested algorithm is improved, as compared to TCP-reno.

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An Efficient Multicast Algorithm for ATM Networks (ATM 망을 위한 효과적인 멀티캐스트 알고리즘)

  • 천상훈;곽경섭
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.24 no.6B
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    • pp.1108-1112
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    • 1999
  • In this paper, we propose an efficient ABR multicast algorithm for ATM networks. In ABR multicast algorithim, the feedback consolidation is necessary to avoid excessive backward resource management (BRM) cells and to aggregate the information from BRM cells received from each branch. The proposed scheme is shown to achieve fast transient response to the congestion status on a branch as well as effectively eliminate the consolidation noise through system simulation.

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Congestion Control Scheme for Multimedia Traffic over ATM ABR Service

  • Kim, Jung-Youp;Lee, Sang-Heok;Park, Young-Bok
    • Proceedings of the IEEK Conference
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    • 2000.07a
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    • pp.525-528
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    • 2000
  • According to the development of B-ISDN on ATM network, the uses of Multimedia service is growing. Although ABR service uses the network resource most effectively because it is able to change the transfer rate, it is not used for multimedia service until recently. In this paper, we set priority queue and non-priority queue in the ATM switch and each queue has threshold so is can be adopted in different transfer rate method. We propose the real-time traffic transfer method over ABR service based on an effective traffic control method.

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Binaural Interaction Component in Auditory Brainstem Responses with Asymmetric Simultaneous Acoustic Stimulation (비대칭 음 강도 양이 동시 자극 청성뇌간유발반응의 양이간섭치)

  • Heo, S.D.
    • Journal of rehabilitation welfare engineering & assistive technology
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    • v.8 no.2
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    • pp.95-99
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    • 2014
  • Binaural interaction can recognize the same intensity sound by stimulating two ears alternatively, and it can be record auditory brainstem responses (ABR). However, We needs to be researched about binaural interaction in asymmetric binaural acoustic stimulation. 17 normal young hearing university students were participated. Clicks were presented at the intensity of 90 dB nHL to one ear and the click intensity was increased from 0 to 90 dB nHL with a separation of 10 dB to another ear, simultaneous. BI waveform was obtained by subtracting the sum of the asymmetrically evoked potentials from the binaurally evoked potentials; i.e. BI = B - (L + R). Latency and amplitude was measured 'peak to following trough' of IV-V complex of BI waveform. Threshold of BIC (t-BIC) was obtained using amplitude depend on stimulus intensities (paired sample t-test). Latency shifted in 4.65, 4.63, 4.57, 4.58, 4.62, 4.6, 4.48, 4.36, 4.23 ms for peak, 5.57, 5.51, 5.51, 5.59, 5.61, 5.55, 5.44, 5.28, 5.19 ms for trough, and amplitude shifted in .0.32, -0.3, -0.34, -0.32, -0.42, -0.53, -0.54, -0.61, $-0.67{\mu}V$ from 0 to 90 dB nHL in every 10 dB, respectively. t-BIC was observed 40 dB nHL(p=.001).

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A Restoration Stategy using Backup VPs on ATM/B-ISDN according to Service Categories (ATM/B-ISDN에서의 서비스 유형에 따른 예비 VPs를 이용한 자동복구 정책)

  • 신해준;김영탁
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.25 no.5B
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    • pp.850-858
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    • 2000
  • Increased network reliability is required as the size of communication network becomes larger and the bandwidth requirement is increasing. And preparing of backup path is required to protect the network from serious network failures in high speed network. In this paper, we construct multiple logical networks on a physical ATM network according to the ATM bearer service category(CBR, rt-VBR, nrt-VBR, ABR, UBR) defined by ATM Forum to support the required QoS(Quality of Service) and to manage the network more efficiently. We use backup path restoration algorithm rather than dynamic restoration to achieve rapid restoration when active path fails and we use fault management function in TINA. We propose a restoration scheme that is suitable for high-speed network.

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ABR Congestion Control for Signal Transmissions in ATM Networks (신호 전송을 위한 ATM 망에서의 ABR 체증제어)

  • 정준영;양현석;계영철;고인선
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.28 no.5B
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    • pp.448-456
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    • 2003
  • In this parer, an ABR (Available Bit Rate) congestion control algorithm for voice transmission in ATM networks was proposed. To deal with the network congestion problem, not only the buffer level of a switch but also the variation of the buffer level were considered. Also, to resolve the unfairness among sources where the bit transfer rates vary, a loading factor that is used to adjust the bit rate was introduced. To show the superiority of this paper over others, simulation was done with a network of 7 voice sources and 4 switches, which was represented by Petri net model. ExSpect was used for simulation. The simulation results showed that there was improvement in network utilization and that unfairness among sources were resolved a lot.

A Study for the Effect of Electrical Stimulation on ABR and ECochG (전기자극이 ABR과 ECochG에 미치는 영향에 관한 연구)

  • Kim, K.S.;Park, J.W.;Im, J.J.;Moon, I.H.;Jeon, B.H.
    • Proceedings of the KOSOMBE Conference
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    • v.1996 no.11
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    • pp.240-242
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    • 1996
  • Use of electrical stimulation for diagnosis and treatment of pyhsiolgocial impairment on the auditory system was reported by many researchers since 1800. Unfortunately, there were no standard methods or theoretical bakground for choosing stimulus conditions because of the lack of understanding on the transmission of sound through the auditory pathways. Therefore, if we could find the mechanisms of normal and abnormal functions for the system objectively, it may be possible to establish the conditions for the appropriate treatment This study was devised with three experimental conditions of electrical stimulation(0.1, 1, and 10mA) to verify the effect of electrical stimulation on the auditory system. ABRs and ECochGs were obtained from 3 Guinea Pigs before and after each stimulation, and five parameters were extracted from ABR and ECochG waveforms. The results showed that the mean differences of the first peaks of ABR, I, before and after all the stimulus conditions were significant at the significant level of p<0.05. Also, amplitude of ECochGs peak(AP) showed higher degrees of differences for the electrical stimulation than that of ABRs. Based on the results of this experiment establishment of an electrical model which characterizes the auditory system could be achieved by computer simulation. This will lead to the design of most accurate model for the real auditory system, which provide the quantitive information regarding diagnosis and treatment.

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Protective Effect of Diallyl disulfide(DADS) from Garlic Extract on Noise Induced Hearing Loss in the Guinea pigs (소음으로 인한 청력소실에 대한 마늘 추출물 diallyl disulfide(DADS)의 효과)

  • Yoon, Min-Young;Cho, Nam-Geun;Hwang, Woo-Jun;Jang, Chul-Ho
    • Journal of Acupuncture Research
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    • v.19 no.2
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    • pp.105-113
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    • 2002
  • Objective : The purpose of this study is to investigate the protective effect of DADS on the noise induced hearing loss Methods : Twenty healthy guinea pigs (DADS pretreated group and control) were exposed to 100dB a collected environmental noise for 9 hours. An auditory evoked brainstem response (ABR) threshold was measured before and after a noise exposure. For morphological study, cochlea was studied by scanning electron microscope (SEM). Results : The DADS pretreated group showed statistically significant less changes in ABR threshold and SEM findings compared the control group. Conclusion : From these results suggest that the DADS from garlic may have a protective effect in noise induced hearing loss.

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