• The Transactions of the Korea Information Processing Society
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• v.4 no.5
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• pp.1308-1318
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• 1997

This paper proposes a new touthind algorithm, the Bandwidth-Delay-Loss based Routing(BDLR) algotithm, which supports the selection of an effcienet routing path by cinsidering the characteristics and QoS requirements of intergarted servies over the Untegrated Serives Packet Network(ISPN), and also compareas it with other touting algorithms by simulating their perfomances on the various combinations of the realtime and non-realtime traffic over the ISPN. The simulation shows that the BDLR algorithm takes great advantages on transmisson dealy, the satisfiability of QoS requirements, and the adapation of traffic envirment over the other routing algorithms priposed for ISPN until now.

• International Journal of Contents
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• v.5 no.3
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• pp.8-13
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• 2009

The recent Web service field emerges as the fastest growing IT paradigm as a result of the increasing interest in SOA (Services-Oriented Architecture) and the expansion of B2B market. With an increasing number of Web service that provide similar features, it becomes more important to provide the most appropriate service for the user's request. A service user in general requires the quality information of Web service when selecting a service among a number of similar Web services. Yet, finding a service through UDDI (Universal Description, Discovery and Integration) does not consider the non-functional aspects of users because it is only based on the functional aspects. That is, the quality, non-functional aspect will be an important factor for the mutual success of the user and provider. Using 3 factors in the Qos factors of the existing studies: the execution cost, reliability, and the quality level, the QoS of Web service is saved and the factors for the QoS are recorded in order to consider non-functional factors when selecting a Web service in this study. The Quality Broker determines the rank and shows the desired result of the service for users. The Quality Broker suggested in this thesis can be used to select a Web Service that considers the user-oriented and non-functional factors.

• Proceedings of the IEEK Conference
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• 2000.07a
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• pp.229-232
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• 2000

AAL2 has been adopted for bandwidth-efficient trans-mission of low bit tate traffic over ATM networks in ITUT and ATM Forum. Since ATM/AAL2 is expected to be used as a switching technology in third-generation mobile access networks and mobile data traffic is expected to increase rapidly in near future, there must be a need for efficient scheduling scheme satisfying the QoS requirement of ow bit rate voice as well as the one of high bit rate data. In this paper, we propose a new class-scheduling scheme to improve data packet loss probability, while Qos of voice traffic is guaranteed, when data traffic is multiplexed together with mobile voice traffic into a single ATM VCC. The proposed scheme can efficiently support data traffic by assigning a time threshold value to voice traffic. Through simulation study, we show that the proposed scheme does not only achieve better efficiency for providing both mobile voice and data services than HOL class-scheduling scheme and normal FIFO scheme, but also guarantees mean voice packet delay under a certain criteria.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.7A
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• pp.717-724
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• 2006

In order to maximize the throughput and provide the fairness between users in MIMO-OFDM system, FATM(fairness-aware throughput maximization) scheduling algorithm was proposed. In this paper, a QoS-aware scheduling algorithms for MINO-OFDM system are proposed, each of which is based on FATM. These scheduling algorithms aim to satisfy the different service requirements of various service classes. Three proposed QoS scheduling algorithms called SPQ (Strict Priority Queueing), DCBQ (Delay Constraint Based Queuing), HDCBQ (Hybrid Delay Constraint Based Queuing) are compared through computer simulations. It is shown that HDCBQ algorithm outperforms other algorithms in satisfying different requirements of various service classes.

• Journal of Korean Institute of Industrial Engineers
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• v.22 no.4
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• pp.771-788
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• 1996

A CDMA-based cellular mobile telecommunication system has already been developed and is expected to provide more stable mobile communication services for much more users than traditional analog mobile systems. As a natural course of development, the CDMA mobile system is expected to provide ISDN services in the near future. In this paper, we analyze several traffic control policies for the voice-data integrated traffic in the cellular CDMA system. We first select four admission control policies which take differences in traffic and QOS characteristics between voice and data into account, and then develop modelling and analysis techniques, which can be used directly to analyze the chosen control policies. Our approach is based on so-called threshold model. Numerical computation results obtained under the typical traffic situation are also given. Through these computation results we could tentatively conclude that the cutoff priority policy, which can provide the priority for handoff voice cells while effectively utilizing unused channels, seems to be most effective among the four policies.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.8
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• pp.1676-1682
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• 2005

PCF(Point Coordination Function) of IEEE 802.11 MAC protocol is an access method oat generally has better performance under high offered load conditions. And it is also appropriate for sending data of time-limited applications. In this paper we consider the QoS(Quality of Service) enhancement method according to the change of nodes in the IEEE 802.11 WLAN. We assume that the un consists or QoS nodes and non-QoS nodes. The QoS nodes has a mechanism to support QoS. we can find the appropriate network parameters by many simulations. And the changes of network status are considered according to the number of nodes.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.16 no.6
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• pp.109-118
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• 2002

As Information society has expanded in large scale. In order to improve the reliability and Qos(Quality of service), domestic IDC(Internet Data Center) has adopted or will adopt the SLAs(Service Level Agreements). The power quality of internet hosting server unit, power system and UPS is very important for better internet service. Therefore, the higher reliability or power system is imperative for satisfying SLAs. This paper presents the status measurement of domestic IDCs harmonics and illustrates the reduction effect of harmonics through the multi-phase.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.459-461
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• 2010

Ad-Hoc VoIP system is an important IP phone technique used in MANET networks. In small-scale networks, VoIP system could be built easily while keeping the Qos on a acceptable level. Although Ad-Hoc VoIP system is designed as 'Client-Server' model, due to the property of MANETs that no Base Stations working as servers, we have the SIP Server with promary funtions worked on mobile terminals instead. In this paper, we explored how to build VoIP systems in MANETs and achieved the construction from within linux.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.1030-1034
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• 2009

IPv6 and Ubiquitous Healthcare Environment (UHE) has become a main stream of the next generation technologies. IPv6 is designed in many ways with enhanced features such as a routing, mobility, scalability, QOS and security as a replacement of IPv4. Also, UHE is developed to provide patients with convenience and efficient healthcare services using the remote home healthcare system. However, IPv4 currently used as an Internet protocol does not have enough capability to fully support UHE. It may result in a restricted implementation of UHE. As a result, research on IPv6 implementations in UHE is increasingly becoming an issue within the healthcare industry. IPv6 has enhanced features to implement the remote healthcare system such as Neighbour Discovery process and address auto-configuration. In this paper, a basic of IPv6 and UHE will be firstly introduced and secondly, benefits brought by IPv6 in UHE will be discussed. In addition, security issues in IPv6 will be analysed to conclude this paper.

• International Journal of Computer Science & Network Security
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• v.21 no.8
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• pp.342-352
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• 2021

Multicast Routings is a big challenge due to limitations such as node power and bandwidth Mobile Ad-hoc Network (MANET). The path to be chosen from the source to the destination node requires protocols. Multicast protocols support group-oriented operations in a bandwidth-efficient way. While several protocols for multi-cast MANETs have been evolved, security remains a challenging problem. Consequently, MANET is required for high quality of service measures (QoS) such infrastructure and application to be identified. The goal of a MANETs QoS-aware protocol is to discover more optimal pathways between the network source/destination nodes and hence the QoS demands. It works by employing the optimization method to pick the route path with the emphasis on several QoS metrics. In this paper safe routing is guaranteed using the Secured Multicast Routing offered in MANET by utilizing the Ant Colony Optimization (ACO) technique to integrate the QOS-conscious route setup into the route selection. This implies that only the data transmission may select the way to meet the QoS limitations from source to destination. Furthermore, the track reliability is considered when selecting the best path between the source and destination nodes. For the optimization of the best path and its performance, the optimized algorithm called the micro artificial bee colony approach is chosen about the probabilistic ant routing technique.