• Journal of the Korea Computer Industry Society
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• v.3 no.1
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• pp.85-94
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• 2002

EMRCA(Explicit Max_min Rate Control Algorithm) switch, which has been proposed in the ATM(Asychronous Transfer Mode) standard, controls the ABR(Available Bit Rate) service traffic in the ATM networks. The ABR service class of ATM networks uses a feedback control mechanism to adapt to varying link capacities. The VS/VD(Virtual Source/Virtual Destination) technique offers the possibility to segment the otherwise end-to-end ABR control loop into separate loops. The improved feedback delay and the control of ABR traffic inside closed segments provide a better performance and QoS(Quality of Service) for ABR connections with respect to throughput, delay, and jitter. This paper is study of an ABR VS/VD flow control method. Linear control theory offers the means to derive correct choices of parameters and to assess performance issues, like stability of the system, during the design phase. The performance goals are a high link utilization, fair bandwidth distribution and robust operation in various environments, which are verified by discrete event simulations. The major contribution of this work is the use of linear control theory to model and design an ABR flow control method tailored for the special layout of a VS/VD switch, the simulation shows that this techniques better than conventional method.

• Journal of Industrial Technology
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• v.21 no.A
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• pp.189-198
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• 2001

In recent years, the predominant part in telecommunications is mobile communications. The next generation network is extending today's voice-only mobile networks to multi-service networks. ATM Network is possible to carry such multi-media traffic and it will be expect to use wireless ATM for the future mobile access network. One of manly important aspects for the performance of wireless ATM is the Medium Access Control (MAC) protocol. The MAC protocol must be able to satisfyingly handle the different ATM services (CBR, VBR, ABR and UBR) with their radically different performance requirements. Additionally, the MAC protocol must be able to cope with the complex radio environment where fading, multi-path propagation interference and burst-errors further complicate the situation. In this paper, a dynamic slot allocation algorithm in wireless ATM is proposed for an efficient channel sharing/media access at the MAC layer. We use equivalent capacity in the allocation of slots for VBR traffic which is variable along the time. It is simple and effective slot allocation method for VBR service. In particular, we consider the slot allocation of a session consisted of several connections for requirement of multimedia traffic. Simulation shows that the cell loss ratio is reduced by re-allocation of extra slots in Mobile Terminal (MT).

• Journal of the Ergonomics Society of Korea
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• v.35 no.5
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• pp.403-411
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• 2016

Objective: This study is concerned with the user interface (UI) design of touch screen based on the reaction time of Automated Teller Machine (ATM) user. Background: Adopting the touch screen technology, the ATM service has recently established a new user interface different from the existing button-type interface. Method: Experiments were conducted by simulating ATM touch screen layouts, and layouts were focused on location of menu buttons (left and right, top and bottom), number of menu buttons (8 and 12 buttons). Results: The results show that there are significant differences in correction ratio and reaction time by user groups, types of menu location, and the number of buttons. Conclusion and Applications: The results of this study can be used to provide baseline information for the interface design of ATM touch screen and the age differences in reaction time.

• The Transactions of the Korea Information Processing Society
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• v.2 no.6
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• pp.927-936
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• 1995

ATM Forum has defined a new service class for data applications called Available Bit Rate(ABR) Service, which has highly bursty traffic and unpredictable burst size. It is desirable that we reduce the probability of retrans mission of packets by minimizing the loss of cells because the traffic is much more sensitive to loss than delay. The Forum has also selected the Rate-Based Control for the ABR service and proposed EPRCA as the control mechanism for the service. This paper proposes the combination of EPRCA and the other feedb ack control mechanisms such as BECN and BP. The combined control mechanism control ABR traffic more efficiently and the simulation results show that the network performance can be improved by choosing the appropriate parameters.

• The Journal of the Acoustical Society of Korea
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• v.19 no.1
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• pp.89-96
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• 2000

ABR service is defined by ATM Forum and ITU for the efficient use of link bandwidth, and 2-pass service policing is proposed for this service. 2-pass service policing is effective by the real-time measurement of the used bandwidth, and this scheme obtains multiplexing gam and control efficiently ABR traffic as dynamically allocating rate by residual bandwidth information. In this study, we propose the real-time bandwidth prediction scheme for ABR traffic control, as using dynamic rate allocation by available bandwidth information. This study can obtain the simple hardware structure by means of as predicting available bandwidth by the total link bandwidth and the sum of transmission rate on the backlogged state connections.

• The KIPS Transactions:PartC
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• v.10C no.3
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• pp.305-310
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• 2003

The performance of various GFR implementations has been recently studied due to the interest to provide bandwidth guarantees with a simpler implementation than ABR in ATM networks. One of the important factors is buffer management for guaranteeing QoS in GFR service. An efficient buffer management algorithm is necessary to guarantee MCR for untagged cell in ATM switch. In this paper, we propose and evaluate a buffer management scheme to provide the GFR service guarantees. The proposed scheme can control the cell discarding for fairness in each VC, and compared with Double-EPD and DFBA. Our results show that the proposed buffer management with per-VC queuing achieves significant enhancement on goodputs and fairness index than those of existing methods.

• The Transactions of the Korea Information Processing Society
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• v.5 no.5
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• pp.1285-1299
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• 1998

Thousands of multimedia services are being developed over existing public networks and high-speed communication networks. In the multi-carrier network, seamless integration of terminals and services is essential in order to offer an end-to-end and user-independent service. In this paper, we propose the concept of the Interworking Broker to provide an infrastructure for building multimedia service interworking platform that supports interactive multimedia applications in distributed heterogeneous network environment. We describe main techniques developed to achieve the service interworking, and also the functional architecture of the Interworking Broker in heterogeneous ATM network environments.

• The Journal of Asian Finance, Economics and Business
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• v.6 no.1
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• pp.141-148
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• 2019

This research proposes a model of SERVQUAL scale calibration and uses the SERVPERF model to study the relationship between quality of ATM service and customer satisfaction. The research uses the combination of qualitative and quantitative methodology with the Cronbach's alpha reliability analysis, Exploratory Factor Analysis (EFA) method; Confirmation Factor Analysis (CFA) and Structural Equation Modeling (SEM) through SPSS and AMOS 20.0 data analysis software. The survey was conducted with 800 questionnaires with the convenient sampling method. The number of remaining sample for analysis was 779 responses of individual customers using ATM card services of Bank for Foreign Trade of Vietnam (Vietcombank) Vinh Long. The results show that the satisfaction of customers using ATM cards of Vietcombank Vinh Long is influenced by 4 factors with the order of importance as follows: (1) Price; (2) Network; (3) Reliability; (4) Empathy. Thereby, the author suggests some managerial implications to Vietcombank Vinh Long management to enhance the ATM service quality, then improve customer satisfaction. This research still has some limitations: (1) The study does not investigate other influencing factors, (2) The convenient sampling method has not been generalized well, (3) The research is only conducted for Vietcombank.

• The KIPS Transactions:PartC
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• v.11C no.6 s.95
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• pp.799-806
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• 2004

A growing diversity of pervasive devices is gaming access to the Internet and other information. However, much of the rich multimedia contents cannot be easily handled by the client devices because of the limited communication, processing, storage and display capabilities. The in-tegration of voice, data and video service modified the target of networking technologies. Networks must have some the capabilities for in-tegration of various services and also for QoS support as required by each of those service. Because of these reasons, we developed EAGIS(Efficient ATM Gateway for real time Internet Service) to provide seamless multimedia service between the ATM network and the Internet. EAGIS consists of the interworking unit, content server, transcoding server, and the serveice broker to provide seamless multimedia service be-tween the ATM network and the Internet. In this paper, we design the architecture and transcoding service scenario of the EAGIS. When the RTP is used for the bi-directional communication, transcoding time is configured by the time-stamp of RTCP. When HTTP is used for unidirec-tional communication, self-timer is used. By using these reference time, standard transcoding method is applicable according to the frame trans-mission rate and network traffic load. And we can also assure the QoS of the multiple users` effective bandwidth by our algorithm.

• Journal of Korea Multimedia Society
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• v.4 no.4
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• pp.339-348
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• 2001

In this paper, a cell scheduling algorithm which can be applied to all of the service class in ATM network is proposed. The proposed algorithm classifies the order of priority in each service class into 4 categories and generates the weight of each class service based on the traffic parameters which are negotiated in connection contract. The proposed algorithm guarantees QoS(Quality of Service) to the traffic which is sensitive to delay carrying out CBR and rt_VBR service. As it effectively manages the connection which has small bandwidth, it minimizes the cell delay in the queue. For verifying the effectiveness of the proposed algorithm the proposed algorithm is simulated with existing cell scheduling algorithm and the result is showed.