• Proceedings of the Korea Information Processing Society Conference
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• 2006.05a
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• pp.1219-1222
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• 2006

3GPP에서는 단대단 QoS 보장을 위해 정책 기반 망 관리(PBNM:Policy-based Network Management) 방식을 적용할 것을 권고하고 있다. 본 논문에서는 3GPP에서 제시하는 핵심망 구조에 정책 기반 망 관리 기법 중 DiffServ를 적용해서 현재 DSCP(Differentiated Service Code Point)는 8bit 구성되어 있으나 그 중 6bit만 사용되고 있고, 사용하지 않는 이 2bit를 사용하여 DF(Default Forwarding), EF(Expedited Forwarding), AF(Assured Forwarding)의 DSCP에 Service Class Code Point를 부여해서 DiffServ를 서비스하는 망에서 동일한 Diffserv 정책을 설정해서 효율적인 QoS 기법을 제안하고자 한다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.4
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• pp.552-558
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• 2002

Differentiated services (DiffServ) architecture defines a new framework for the support of quality of service (QoS) in IP-based networks. RIO has received the most attention among all the active queue management mechanisms proposed for assured service in DiffServ environment. The paper proposed the enhanced RIO which could alleviate the impact of flow's packet sire on the realized throughput. The simulation results indicate that this mechanism, when combined with TSW as traffic conditioner, provide better throughput assurance and fair distribution of excess bandwidth independent of packet size of flows in case of well-provisioned network environment.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.05a
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• pp.121-124
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• 2002

In Diffserv Network, RIO is the most effective active queue management algorithm. RIO, the enhanced queue management algorithm from RED, divides IN and OUT packets and manages them differently. one of the main problems for the implementation of RIO is the Bandwidth Skew problem for providing the Assured Service. In this paper, we will show the bandwidth skew problem in RIO and provide an enhanced RIO mechanism that will alleviate the bandwidth skew problem.

• Journal of the Korea Computer Industry Society
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• v.2 no.4
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• pp.417-424
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• 2001

Internet networks consisting of existing routers show the limits in efficiency of traffic managements. In order to overcome the limits, MPLS System is high speed switching technology and is not based on IP address but based on label was designed. However MPLS system being based on ATM has the difficulties of supporting Qos(Quality of Service). This paper suggested the way to consist a service-assured-network using CR-LDP protocol which was designed for guaranteeing QoS in MPLS system being based on ATM switch and using qGSMP protocol, and the way to implicitly establish LSP by implementing QoS Translation and QoS Mapping in LER System.

• IEMEK Journal of Embedded Systems and Applications
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• v.4 no.2
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• pp.79-83
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• 2009

Streaming Technology can support the real-time playback without downloading and storing multimedia data in local HDD. So, client browser or plug-in can represent multimedia data before the end of file transmission using streaming technology. Recently, the demand for efficient real-time playback and transmission of large amounts of multimedia data is growing rapidly. But most users' connections over network are not fast and stable enough to download large chunks of multimedia data. In this paper, we propose an intelligent IP streaming system based on personalized media service. The proposed IP streaming system enables users to get an intelligent recommendation of multimedia contents based on the user preference information stored on the streaming server or the home media server. The supposed intelligent IP streaming system consists of Server Metadata Agent, Pumping Server, Contents Storage Server, Client Metadata Agent and Streaming Player. And in order to implement the personalized media service, the user information, user preference information and client device information are managed under database concept. Moreover, users are assured of seamless access of streamed content event if they switch to another client device by implementing streaming system based on user identification and device information. We evaluate our approach with manufacturing home server system and simulation results.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.4 no.5
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• pp.691-708
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• 2010

An important issue of supporting multi-users with diverse quality-of-service (QoS) requirements over wireless networks is how to optimize the systematic scheduling by intelligently utilizing the available network resource while, at the same time, to meet each communication service QoS requirement. In this work, we study the problem of a variety of communication services over multi-media heterogeneous cognitive OFDM system. We first divide the communication services into two parts. Multimedia applications such as broadband voice transmission and real-time video streaming are very delay-sensitive (DS) and need guaranteed throughput. On the other side, services like file transmission and email service are relatively delay tolerant (DT) so varying-rate transmission is acceptable. Then, we formulate the scheduling as a convex optimization problem, and propose low complexity distributed solutions by jointly considering channel assignment, bit allocation, and power allocation. Unlike prior works that do not care computational complexity. Furthermore, we propose the FAASA (Fairness Assured Adaptive Sub-carrier Allocation) algorithm for both DS and DT users, which is a dynamic sub-carrier allocation algorithm in order to maximize throughput while taking into account fairness. We provide extensive simulation results which demonstrate the effectiveness of our proposed schemes.

• Journal of the Korea Society of Computer and Information
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• v.19 no.12
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• pp.209-218
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• 2014

The more mobile devices consuming web services, the more QoS-aware selection of mobile web services, we need. A QoS(Quality of Service) contract is an agreement between the web service provider and the mobile user that specifies the level of the service quality. Web services users can be assured of the level of the service quality specified by the QoS contract. We propose a broker-based framework for QoS-aware mobile web services selection in this work. Under this architecture, the mobile users can request the web services through the service broker on the wireless networks. The service broker utilizes agents to monitor the web services quality and manages the service quality by notifying the service provider and mobile user of the service contract violation. Reliability, response time, and cost were the metrics used for QoS monitoring. Futhermore mobile users can select a web service best suited for his/her needs through the service broker.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2010.07a
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• pp.360-363
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• 2010

Streaming Technology can support the real-time playback without downloading and storing multimedia data in local HDD. So, client browser or plug-in can represent multimedia data before the end of file transmission using streaming technology. Recently, the demand for efficient real-time playback and transmission of large amounts of multimedia data is growing rapidly. But most users' connections over network are not fast and stable enough to download large chunks of multimedia data. In this paper, we propose an intelligent IP streaming system based on personalized media service. The proposed IP streaming system enables users to get an intelligent recommendation of multimedia contents based on the user preference information stored on the streaming server or the home media server. The supposed intelligent IP streaming system consists of Server Metadata Agent, Pumping Server, Contents Storage Server, Client Metadata Agent and Streaming Player. And in order to implement the personalized media service, the user information, user preference information and client device information are managed under database concept. Moreover, users are assured of seamless access of streamed content event if they switch to another client device by implementing streaming system based on user identification and device information. We evaluate our approach with manufacturing home server system and simulation results.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.12B
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• pp.2109-2119
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• 2000

In this paper, the Packet CDMA Reservation ALOHA protocol is proposed to support the multi-traffic services such as voice and videophone services with handoff calls, high-rate data and low-rate data services efficiently on the multi-rate transmission in uplink cellular systems. The frame structure, composed of the access slot and the transmission slot, and the proposed access permission probability based on the estimated number of contending users for each service are presented to reduce MAI. The assured priority to the voice and the videophone handoff calls is given through higher access permission probability. And through the proposed code assignment scheme, the voice service can be provided without the voice packet dropping probability in the CDMA/PRMA protocols. The code reservation is allowed to the voice and the videophone services. The low-rate data service uses the available codes during the silent periods of voice calls and the remaining codes in the codes assigned to the voice service to utilize codes efficiently. The high-rate data service uses the assigned codes to the high-rate data service and the remaining codes in the codes assigned to the videophone service. Using the Markov-chain subsystem model for each service including the handoff calls in uplink cellular systems, the steady-state performances are simulated and analyzed. After a round of tests for the examples, through the proposed code assignment scheme and the access permission probability, the Packet CDMA Reservation ALOHA protocol can guarantee the priority and the constant QoS for the handoff calls even at large number of contending users. Also, the data services are integrated efficiently on the multi-rate transmission.

• The Journal of the Korea Contents Association
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• v.18 no.5
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• pp.71-81
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• 2018

In korea, the infantile abandonment is increasing recently. In this situation, present study aims to analyze german "confidential birth service"(vertrauliche Geburt) and to find out implications for korean practice. the results of the study are as follows. "confidential birthservice" is centered on pregnancy counseling center. Through this service, pregnant women in crisis are assured of their anonymity and can safely bring baby into the world. After the child is 16 years old, they can learn about personal information of their biological mother. These "confidential birth service" has received positive evaluation in terms of accessibility, sustainability and reliability of services, linkage and cooperation among agencies, quality of counseling and publicity. Implication for Korean pratice include the provision of legal and institutional devices for "confidential birth services", the establishment of implementing agencies, cooperation with related organizations, and the strengthening of the capacity of practitioners, as well as suggestions in the field of counseling and public relations.