• Journal of Internet Computing and Services
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• v.4 no.5
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• pp.61-68
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• 2003

In this paper, we propose a wireless MAC protocol named APRMA, which is capable of supporting the ABR type data service and Maximizing channel utilization. Data terminals with random data packets are not provided slot reservation with PRMA protocol. That is, slot reservation is applicable to the time constraint voice packet exclusively. But the reservation scheme have to be performed for loss sensitive data packet, and contended their quality of service, Therefore, in wireless MAC, reservation technique has to be used for both voice and data services. So the terminal which wants to request for ABR type service, is allocated a minimum bandwidth from system for the first time, If the system have some extra available bandwidth, ABR terminals would acquire additional bandwidth slot by slot, As a result, APRMA protocol can support the data service with loss sensitivity and maintain their channel utilization high.

• Proceedings of the IEEK Conference
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• 1998.06a
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• pp.134-137
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• 1998

In this paper, we propose a new consolidation algorithm for point-to-multipoint ABR flow control and compare the performance of the proposed algorithms with that of an existing consolidation algorithm. We first investigate problems of the existing algorithm in consolidating backward RM cells and propose two new consolidation algorithms to resolve these problems. Also, we investigate the performance of the proposed algorithms by simulation. As results, we show that the proposed algorithms exhibit a better performance than the existing algorithm in terms of ACR, queue length, utilization, and fairness.

• Speech Sciences
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• v.11 no.4
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• pp.143-150
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• 2004

This study was done to compare thresholds between those of Auditory Brainstem Response (ABR) with clicks or tonebursts and Multiple Auditory Steady-State Response (MASTER). The results would give a promising tool for evaluating frequency-specific hearing sensitivity in infants or young children. The correlation coefficient value between the click ABR thresholds and MASTER thresholds at carrier frequencies, 500, 1,000, 2,000 Hz, and 4,000 Hz was obtained at Pearson 0.91, 0.94, 0.93, and 0.91.

• Nonlinear Functional Analysis and Applications
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• v.29 no.1
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• pp.113-130
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• 2024

In this work, we explore the existence and uniqueness results for a class of boundary value issues for implicit Volterra-Fredholm nonlinear integro-differential equations (IDEs) with Atangana-Baleanu-Riemann fractional (ABR-fractional) that have non-instantaneous multi-point fractional boundary conditions. The findings are supported by Krasnoselskii's fixed point theorem, Gronwall-Bellman inequality, and the Banach contraction principle. Finally, a demonstrative example is provided to support our key findings.

• Proceedings of the Korean Information Science Society Conference
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• 1998.10a
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• pp.374-376
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• 1998

ABR서비스는 ATM 망의 이용률을 증대시키고, 매우 버스트한 트래픽 응용을 지원하기위해 설계되었다. ATM 포럼에서는 망에서 소스의 셀 전송률을 조절하고 셀 손실을 최소화하기 위한 ABR 서비스 표준으로 폐쇄루프와 전송률기반의 폭주 제어 알고리즘을 채택하였다. 이러한 폭주 제어 알고리즘 중에서 대표적인 것이 ERIVCA(Explicit Rare Indication for Congestion Avoidance) 이다. 본 논문에서는 ERIVCA 의 견고성, 공평성 LAN/WAN 환경에 대해서 성능을 시험하고. 그 결과로 성능을 향상시키기 위해 개선된 최대-최소 구조를 제공한다. 또한 제안된 구조에 대한 시뮬레이션을 하여 기존 ERIVCA 알고리즘의 성능과 비교 분석한다.

• Proceedings of the Korean Information Science Society Conference
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• 1998.10a
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• pp.371-373
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• 1998

한국 ATM 망에서는 ABR서비스를 위한 트래픽 제어 방법에 관한 연구가 활발히 진행되고 있으며, 표준으로 정해진 것들도 많다. 또한 ATM 망에서의 대역폭 관리에 대해서도 많은 연구가 진행되고 있으며 보다 많은 연구가 필요한 실정이다. 기존의 대역폭 관리 모델들은 ABR 서비스를 보장해 줄 수 있는 방안이 마련되지 않았으므로, CBR과 VBR서비스의 이용이 늘어날 경우 ABR서비스를 보장할 방법이 없었다. 이 논문에서는 ATM 망에서늬 대역폭 관리방법들에 관해 분석하였고, 대역폭 관리 방법들을 개선하여 ABR서비스를 보장할 수 있는 동적인 대역폭 관리 모델을 제안하였다.

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.8
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• pp.629-637
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• 2000

Unbalance between user requirements and insufficient network resources makes a congestion. In the future since the communication networks will have very heavy traffic congestion will be more serious. The ATM networks was recommended to support the B-ISDN service for the future multimedia communication. In thie sense of congestion avoidance and recovery the ABR service category in ATM networks allows the feedback flow control mechanism to dynamically allocate the idle bandwidth of the network to users fairly and to control the network congestion rapidly In this paper we introduce a congestion control scheme using systematical approach to confirm robust stability with respect to unknown round trip delay for the network which has both unicast and multicast connections.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.11
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• pp.962-966
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• 2001

The major problem at a branch point for point-to-multipoint available bit rate(ABR) services in asynchronous transfer mode (ATM) networks is how to consolidate backward resource management(BRM) cells from each branch for a multicast connection. In this paper, we propose an efficient feedback consolidation algorithm based on an adaptive dynamic threshold(ADT) to eliminate the consolidation noise and the reduce the consolidation delay. The main idea of the ADT algorithm lies in that each branch point estimates the ABR traffic condition of the network through the virtual queue estimation and the transmission threshold of the queue level in branch points is adaptively controlled according to the estimation. Simulation results show that the proposed ADT algorithm can achieve a faster response in congestion status and a higher link utilization compared with the previous works.

• Review of KIISC
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• v.8 no.2
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• pp.49-62
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• 1998

ATM 방식을 근간으로 한 광대역 통신망이 확산됨에 따라 멀티미디어 서비스 특히, 인터넷 서비스의 지원이 일반적인 추세이다. 이처럼 다양한 서비스에 의해 발생된 트래픽은 단순히 망 부하의 증가에 그치는 것이 아니라, 다양한 QoS를 요구하고 있다. 다양항QoS와 높은 대역폭 사용도의 동시만족이란 과제가 ATM 망에서 주요 목표임이 확실시되면서 많은 호 접속 제어 방식이 제안되었고 계속해서 연구되고 있다. 특히, 자원 할당이란 주요 기능을 내재하고 있는 호 접속 제어는 VC단위에서만 제어가 가능하므로 대역폭 이용률은 저조해진다. 따라서 본 논문에서는 적절한 호 접속 제어 메커니즘을 개발하기 위해서 ABR의 전송률 제에의 구조와 아울러 호 접속 제어의 특징과 알고리즘을 분석해본다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.2
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• pp.268-279
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• 1997

In this paper, we show the movable boundary (MB) method is the effective bandwidth allocation strategy for the ABR service among existing bandwidth allocation methods. The MB method can gurantee the QOS requirement according to the service priority and improve bandwidth utilization using the characteristics of the ABR service. The threshold values of the MB, which have an important effect upon connection blocking probability(CBP) performance of each service, are obtained by simulation. The MB method with the fixed thresholds, however, may not have good performance to variation of input traffic parameters. We suggest the dynamic MB method which changes the threshold values adaptively according to the required bandwidth of input traffic. We also show that the dynamic MB method can urantee the CBP performance according to the service priority regardless of variation of input traffic parameters.