• 한국정보통신학회논문지
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• 제7권6호
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• pp.1168-1176
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• 2003

인터넷 전화 서비스는 저렴한 가격과 타 서비스와 통합 및 가치부가면에서 기존의 전화에 비해 많은 장점을 가지고 있으나, 상대적으로 낮은 음질로 인하여 사용자의 요구를 만족시키지 못하고 있다. 이것은 인터넷이 best-effort형 패킷 전달 서비스만을 제공하고 있기 때문에 지연, 패킷 손실 및 지터 등을 보장할 수 없기 때문이다. 본 논문에서는 인터넷 전화에서 전송지연으로 인한 패킷손실을 감소시키기 위해 수신 패킷을 사람이 인지 가능한 수준까지 확장하여 playout 시킬 수 있는 FEAPT 알고리즘을 제시한다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -3
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• pp.1855-1858
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• 2002

A number of MPLS ATM systems have been proposed to increase the access speed of current routers, which only support the best-effort service. However, the MPLS ATM systems have to support the so-called differential service, which discriminates the applications according to the service class because they do not be satisfied the Internet users who use diverse applications. In this paper, to support this differential service a detailed forwarding procedure based on a LSP control method and an application-based marking algorithm is suggested. The LSP control method establishes several different LSPs for each FEC according to the service class and the application-based marking algorithm chooses a proper differential service depending on the application category. Also, a design scheme of forwarding engine, which can be easily implemented with a minimum modification of existing MPLS ATM systems is proposed. And, the best simulation result of high priority application category is gained when the proposed forwarding algorithm is comparedwithexistingalgorithms.

• 대한안전경영과학회지
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• 제2권4호
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• pp.165-176
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• 2000

Broadband networks are designed to support a wide variety of services with different traffic characteristics and demands for Quality of Services. Bandwidth allocation methods can be classified into two major categories： static and dynamic. In static allocation, bandwidth is allocated only at call setup time and the allocated bandwidth is maintained during a session. In dynamic allocation, the allocated bandwidth is negotiated during a session. The purpose of this paper is to develop policies for deciding and for adjusting the amount of bandwidth requested for a best effort connection over such as ATM networks.. This method is to develop such policies that a good trade off between utilization and latency using cell delay variation to the forecast the incoming traffic in the next period. The performances of the different polices are compared by simulations.

• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2007년도 학술대회
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• pp.327-330
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• 2007

This article discusses a capacity planning method in QoS-guaranteed IP networks such as BcN (Broadband convergence Network). Since IP based networks have been developed to transport best-effort data traffic, the introduction of multi-service component in BcN requires fundamental modifications in capacity planning and network dimensioning. In this article, we present the key issues of the capacity planning in multi-service IP networks. To provide a foundation for network dimensioning procedure, we describe a systematic approach for classification and modeling of BcN traffic based on the QoS requirements of BcN services. We propose a capacity planning framework considering data traffic and real-time streaming traffic separately. The multi-service Erlang model, an extension of the conventional Erlang B loss model, is introduced to determine required link capacity for the call based real-time streaming traffic. The application of multi-service Erlang model can provide significant improvement in network planning due to sharing of network bandwidth among the different services.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2000년도 추계학술발표논문집
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• pp.131-134
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• 2000

Broadband networks are designed to support a wide variety of services with different traffic characteristics and demands for Quality of Services. Bandwidth allocation methods can be classified into two major categories: static and dynamic. In static allocation, bandwidth is allocated only at call setup time and the allocated bandwidth is maintained during a session. In dynamic allocation, the allocated bandwidth is negotiated during a session. The purpose of this paper is to develop policies for deciding and for adjusting the amount of bandwidth requested for a best effort connection over such as ATM networks. This method is to develop such policies that a good trade off between utilization and latency using cell delay variation to the forecast the incoming traffic in the next period. The performances of the different polices are compared by simulations.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2002년도 가을 학술발표논문집 Vol.29 No.2 (3)
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• pp.598-600
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• 2002

SIP(Session Initiation Protocol) 프로토콜은 인터넷에서 다양한 세션을 위한 시그널링 프로토콜로서 오디오, 비디오 등의 멀티미디어 세션에 주로 사용되고 있다. 또한 망 유지보수 및 관리가 편리하고 다른 시스템과의 확장성 및 유연성이 뛰어나다는 장점을 갖고 있는 반면 기본적으로 Best Effort 서비스만을 지원하는 IP 네트워크에서 QoS(Quality of Service)를 제공하기 때문에 서비스의 품질에 대한 고려가 미약하다. 따라서 본 연구에서는IP 네트워크를 기반으로 하는 SIP에서 QoS를 제공하기 위해 IntServ(Integrated Services)와 DiffServ(Differentiated Services)를 연동한 QoS 메카니즘을 제시한다.

• 한국컴퓨터산업학회논문지
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• 제2권12호
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• pp.1505-1516
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• 2001

The goal of Medical multimedia server is to develop computer hardware and software which would enable electronic access, storage, transmission, and display of patient data and images. Since the current network only provides so called "best-effort" services, it is impossible to satisfy QoS guarantee that is required for real time application services for emergency room, operating room etc. Accordingly, world-wide research is being made for a variety of services to provide QoS. he goal of DiffServ is to offer scalable differentiated service in Internet which are made possible by traffic classification and conditioning only performed at an edge(or a boundary) node. In case DiffServ was deployed in the Medical multimedia network, it is difficult to estimate how the QoS mechanism would affect totally the network performance. Therefore, we need to verify by simulation the design of algorithm which provide a variety of differentiated services. In QoS for Medical multimedia network, a simulator is designed and implemented using OPNET to investigate the performance of DiffServ QoS support mechanism. The developed DiffServ simulator may generate packets according to random, and bursty traffic models in order to incorporate diverse traffic conditions in the Medical multimedia network environment. Based on our simulation results, we confirmed that service differentiation is possible by using the EF(Expedited Forwarding) class in DiffServ networks.

• Journal of Communications and Networks
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• 제9권3호
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• pp.319-329
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• 2007

This paper presents a price-based quality-of-service (QoS) control framework for two-class network services, in which circuit-switched and packet-switched services are defined as "premium service class" and "best-effort service class," respectively. Given the service model, a customer may decide to use the other class as a perfect or an imperfect substitute when he or she perceives the higher utility of the class. Given the framework, fixed-point problems are solved numerically to investigate how static pricing can be used to control the demand and the QoS of each class. The rationale behind this is as follows: For a network service provider to determine the optimal prices that maximize its total revenue, the interactions between the QoS-dependent demand and the demand-dependent QoS should be thoroughly analyzed. To test the robustness of the proposed model, simulations were performed with gradually increasing customer demands or network workloads. The simulation results show that even with substantial demands or workloads, self-adjustment mechanism of the model works and it is feasible to obtain fixed points in equilibrium. This paper also presents a numerical example of guaranteeing the QoS statistically in the short term-that is, through the implementation of pricing strategies.

• 교육시설 논문지
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• 제23권2호
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• pp.11-18
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• 2016

University dorm basically provides basic housing functions to students, however, it is very important in a sense that it provides students with various functions such as information exchange, cultural experience and learning environments as well. Additionally, continuous effort to improve users' satisfaction and living environments are needed due to the fact that physical environments of dorm facilities have higher impact on students. However, Many students are not satisfied with the physical environment of university dorms and also there is lack of systematic information whereas various functions are required by students. Therefore, the main objective of this research is to suggest the direction of FM services in order for improving students' satisfaction on the university dorm facilities in Korea. Precedent studies regarding the satisfaction or performance evaluation of dorm facilities have been extensively analyzed to extract the dissatisfaction factors that scored below the middle 50%. Secondly, for satisfaction improvement, Korean Standard for Facility Management(KS_FM) have been matched with those extracted dissatisfaction factors to suggest the direction of FM services by rules and regulations review and best practice studies. This research will be useful for university dorm facility managers in planning strategic FM and providing effective FM services to students.

• International Journal of Internet, Broadcasting and Communication
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• 제9권2호
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• pp.27-36
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• 2017

The world's unique geographical, multilingual, multiethnic, multiracial and multi religious Himalayan country Nepal has more than 100 years history on telephony service and it has been formulating appropriate policy and regulation for the adoption of new technology, introducing the competitive market environment for the overall development of Information and Communication Technology (ICT) infrastructures and application of ICT service and tools for socio-economic transformation. The Nepalese market seems to be continuously growing and having huge demand of mobile telephony and internet subscriptions trend. The ICT infrastructure development in difficult geographical area is quite challenging and thus operators are focusing mobile telephony and mobile internet services. Nepal has been doing its best effort on formulating policy and regulation, adoption key strategies for ICT sector development and at the same time joining hands with international and regional bodies such as ITU, SAARC etc for ICT sector development. Due to geographical diversity, policy and regulatory barriers in some extent, power supply constraints and low affordability from customers on ICT tools and services, Nepal has been facing challenges on ICT infrastructure development. However, the national statistics on ICT, Networked Readiness Index and ICT Development Index show that Nepal has done quite good progress and is keeping its pace on ICT development despite the these challenges. Moreover, there seems to be quite uncovered market segments on internet service and big opportunity on ICT sector development in Nepal in the days to come.