• Proceedings of the Korea Information Processing Society Conference
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• 2003.11b
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• pp.1233-1236
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• 2003

VoIP 기술의 확산과 그에 따른 IP기반의 망을 포함한 Packet, Multimedia서비스를 제공하는 서비스가 늘고 있다. 실시간 서비스를 필요로 하는 음성 트래픽 같은 경우에는 그에 따른 경로에 확실한 QoS의 보장 조건이 요구되며 사용자가 지불한 대금에 따라 서비스에 차별성을 두는 차등 서비스에 대하 연구가 활발해지고 사용자들에게 신뢰성 있는 서비스를 제공할 수 있는 기술이 필요하게 되었다. IP 네트웍에서의 음성전송은 현재의 전화통신요금보다. 절반 이상 저렴하고 여러 가지 부가 서비스를 창출할 수 있다. 하지만 Best-effort Service만을 지원하는 기존의 망에서는 실시간 서비스의 품질을 보장할 수가 없기에 실시간 서비스에 대한 품질보장이 반드시 필요하다.

• Journal of Distribution Science
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• v.13 no.10
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• pp.5-13
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• 2015

Purpose - This study aims to suggest appropriate policies and performance indicators for financial aid recipients. It analyzes the existing regular government policy funds support project, especially its propriety and reasonability. Research design, data, and methodology - When financial aid is effective, it should be able to predict small enterprise business results. Additionally, there should be an evaluation, checking before and after performance rates so that the rate of achievement and outcome can be measured. This study's contribution for small enterprises is in researching the best way to improve this support system. Results - The Small Enterprise and Market Service (SEMAS), currently designated as a support organization for implementing the government financial aid project, has assessment indicators. However, these focus mainly on quantitative indicators and survey results. Conclusions - In the future, there is some need to draw up measures, setting the right direction for developing policies for the small enterprise fund loans and improving the management of the plans. Eventually, this effort will dispel concerns about the present support policy, which is considered to be weakening small enterprises.

• Proceedings of the Korean Information Science Society Conference
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• 2002.10e
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• pp.172-174
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• 2002

인터넷의 급속한 성장과 함께 웹을 기반으로 하는 서비스들이 더욱 확산되며 중요해지고 있다. 하지만 제한된 네트웍 환경에서 웹 트래픽의 지수적인 증가로 인해 웹 서비스의 품질 보장 문제가 대두되고 있지만 현재의 인터넷은 최선의 서비스(Best-effort service)만을 제공하며, 품질 보장형의 서비스(QoS)는 제공하지 못하고 있는 것이 현실이다. 본 논문에서는 기존에 구축되어진 웹 클러스터 모델 중에서 서버의 부하 분산을 담당하고 있는 디스패처(Dispatcher)에 대기 정렬 큐잉(Class Based Queuing)의 패킷 전송 모델을 적용하고자 한다. 제안된 모델을 통하여 클러스터 기반 웹 서비스에서 원하는 클래스의 서비스 품질을 보장할 수 있다.

• Proceedings of the Korean Information Science Society Conference
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• 2001.04a
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• pp.130-132
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• 2001

현재 인터넷은 노력형 서비스(Best-effort service)만을 제공하며, 보장형 서비스(Guaranteed service)를 제공하지 못하는 한계를 가지고 있다. MPEG1, MPEG4, H.263과 같은 실시간 비디오 데이터를 효과적으로 제공하기 위해서는 보장형 서비스를 필요로 하며, 세션 관리, 호 허용 제어, 패킷 스케쥴링과 같은 여러 가지 기술들이 필요하다. 기존에 주로 사용되고 있는 FIFO(First-in First-out)에 의한 큐잉 정책으로는 대역폭, 지연 시간과 같은 네트워크 자원을 사용자에게 보장해 줄 수 없다. 따라서 CBQ(Class Based Queuing), WFQ(Weight Fair Queuing)아 같은 공평 큐잉 기법들에 대한 연구가 필요하다. 본 논문에서는 WFQ와 같은 공평 큐잉 기법을, 실시한 비디오 패킷 전송에 효과적으로 사용하기 위한 방법(AWF2Q+)을 제안하였다. FIFO, WFQ, AWF2Q+의 서비스 품질(PSNR)에 대한 비교, 분석을 통해 제안한 알고리즘이 실시간 비디오 서비스의 품질(PSNR)을 향상할 수 있다는 것을 보였다.

• Journal of KIISE:Information Networking
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• v.27 no.3
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• pp.339-347
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• 2000

최선형 서비스(best effort service) 방식의 현재 인터넷은 실시간 응용의 출현과 보다 나은 서비스를 기대하는 사용자들에 의해 많은 변화가 요구되고 있다. 이러한 요구를 만족시키기 위해서 새로운 프로토콜, 트래픽 제어 및 QoS 라우팅 등에 관한 연구가 진행되고 있으며, 최근 트래픽 제어를 통해 서로 다른 수준의 서비스를 제공하는 차별화 서비스(differentiated service)모델에 관하여 많은 연구가 진행중이다. 두 가지 우선 순위를 바탕으로 사용자에게 어느 정도 예측 가능한 대역폭을 제공하는 RIO 모델은 차별화 서비스의 대표적인 모델이다. 하지만 RIO 모델에서 제공하는 대역 분배 방식은 네트워크 용량이 충분치 못한 상황에서는 서비스 차별화가 이뤄지지 않으며, 잉여 대역폭의 적절한 분배가 이뤄지지 않는다. 본 논문에서는 시뮬레이션을 통하여 네트워크 상황에 따른 RIO모델의 대역 분배 성능을 분석하였으며, 이를 개선하여 보다 효과적인 서비스 차별화가 이뤄지도록 하였다.

• Journal of Korean Library and Information Science Society
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• v.1
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• pp.1-15
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• 1974

The public library and micro-library as institutions of social education have been greatly developed under the influence of the library law enacted 011 Octob~r 28,1963 and the micro-library movement begun in 1961. However, they have still yet many problems to solve in order to accomplish their purpose effectively. As compared with the staff and library materials, buildings are 1norc. than a match for the others. Although many facilities are not complete enough to serve the public, people do not make the best of the facilities in both the public libraries and micro-libraries. The cause of such a result ~vould be taken from a reason that the founders of the libraries could not concentrate their intcrest on the staff and materials, for they were bent on the establishment of external facilities of the libraries. The poorer materials and facilities are, the more effort a2d better quality of the staff are required for their best utilization. As it is the information center of the community, the management of a library should be scientific and reasmable. In addition, librarians have to do their best to serve the public with the spirit of Christianity under the more active suppxt of the government. Finally, institutions of social education in this comn~unityin cluding public libraries and micro-libraries might establish a mutual cooperative organization for more effective library service.

• Proceedings of the IEEK Conference
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• summer
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• pp.143-146
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• 2004

Differentiated services (DiffServ) has been widely accepted as the service model to adopt for providing quality-of­service (QoS) over the next-generation IP networks. There is a growing need to support QoS in mobile ad hoc networks. Supporting DiffServ in mobile ad hoc networks, however, is very difficult because of the dynamic nature of mobile ad hoc networks, which causes network congestion. The network congestion induces long transfer packet delay and low throughput which make it very difficult to support QoS in mobile ad hoc networks. We propose DiffServ module to support differentiated service in mobile ad hoc networks through congestion control. Our DiffServ module uses the periodical rate control for real time traffic and also uses the best effort bandwidth concession when network congestion occurs. Network congestion is detected by measuring the packet transfer delay or bandwidth threshold of real time traffic. We evaluate our mechanism via a simulation study. Simulation results show our mechanism may offer a low and stable delay and a stable throughput for real time traffic in mobile ad hoc networks.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.2 no.3
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• pp.401-408
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• 1998

Recently there comes out various applications on real time control, audio/video conference, medical image and so on. These applications request certain Quality of Service(QoS) to their underlying communication subsystem. In these cases those communication subsystems should provide real time communication service on their QoS request as well as good performance to maintain best effort traffic. In this paper firstly we briefly look over bandwidth, traffic parameters on point to point network secondly we analyze on real time channel and propose design factors in real time channel protocol for multimedia applications.

• The Journal of the Korea Contents Association
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• v.9 no.5
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• pp.265-276
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• 2009

Many disaster management actors participate in the disaster sites and they do their best for the best result in their given position. They recover the disaster-stricken area, endeavor to prevent the disaster's relapse, and to rescue and protect the disaster victims. Ultimately, the purpose of their role and effort is to support a physical aid as well as material aid for that disaster victims can return their living condition to the original one before the disaster. However, the disaster management services have been provided in the supplier's view till now. Subsequently, despite significant efforts, providers have failed to comprehend what would be the victim's demand and how to reflect that in the disaster management service. In this paper, we approached and analyzed the recent disaster management service in the way of grounded theory, and endeavored to find the solution which disaster victims preferred. As a result of analysis, we found 184 concepts, 28 sub-categories, and 9 categories which could explain the victims' desired solution. We found that "an imperfect restoration which causes disaster" and "pain of the disaster field" would be main categories among them.

• Journal of Broadcast Engineering
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• v.12 no.2
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• pp.80-92
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• 2007

IPTV Services that is representative union service of broadcasting and telecommunication need guarantee of QoS, efficiency of multicasting, and hish bandwidth on the network. Because typical TDM based metro transport network was designed by transporting fixed voice traffic with stable and recovering method, it has a defect of bottleneck and a waste of bandwidth for acceptance of data traffic with burst feature and then all of data are treated equally at the transport network because it cannot classify between advanced high end service and best effort low end service. for completely resolving this kind of problem about increasing burst traffic and QoS issues, firstly we need to new design for transport network. This paper presents transformation method from TDM based metro transport network to packet based transport network and advantage and effectiveness of packet based transport network and also indicates technical factor and characters about method of packet transport system. As a result of research, the Packet Transport System, which is a transmission network for packet delivery, take in not only a specific character of legacy TDM but QoS, Multicast and high bandwidth, then, it is able to keep an effective bandwidth and a stabilized performance of packet transmissions. Additionally, if a fault be occurred on an optical link, the system is able to guarantee a differential QoS by an each service class using an algorithm to make certain of a traffic existence and contain a protective mechanism.