• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.10C
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• pp.945-950
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• 2002

In this paper the performance evaluations on Asynchronous Transfer Mode(ATM) access node are performed in the ATM access network which consists of access node and channel. The performance factors of access node are Cell Loss Ratio(CLR), buffer capacity and delay time. Both the ATM cell-scale queueing model and burst-scale queueing model are considered as the traffic model of access node for various traffic types such as Constant Bit Rate(CBR), Variable Bit Rate(VBR) and random traffic in the ATM access networks. Based on these situations, the relation of CLR, buffer capacity and delay time is analyzed in the ATM access node.

• The KIPS Transactions:PartC
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• v.16C no.3
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• pp.383-392
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• 2009

Next generation network (NGN) is a packet-based converged network to support session and non-session services in QoS-enabled broadband transport network. QoS based resource control must be defined to support differentiated services for various network users in NGN. This paper defined parallel control schemes for NGN resource control interfaces to minimize session and resource control delays. We simulated the existing and proposed NGN control schemes to measure and analyze control delays and completion ratios. By arrival rate of 120 in two-phase resource control, we checked out that completion ratios of sequential and parallel schemes achieved 100%, and the control delay of parallel scheme was improved by about 21.5% compared to that of sequential scheme.

• Journal of Broadcast Engineering
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• v.6 no.3
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• pp.225-233
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• 2001

Real-time video communication applications over Internet should be able to support such functionality as scalability because of the unpredictable and varying channel bandwidth between server and client. To accommodatethe wide variety of channel bitrates, a new scalable coding tool, namely the Fine Granular Scalability (FGS) coding tool has been reduce the adopted In the MPEG-4 video standard. This paper presentsa new FGS algorithm with matching Pursuit that can reduce the computational complexity of ordinal matching pursuit-based algorithm. The Proposed coding algorithm can make trade-off between Picture Quality and computationalcomplexity. Our simulation result shows that the proposed algorithm can reduce the computational cumplexity up to 1/5 compared to the conventional FGS method while retaining a similar picture quality.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.9A
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• pp.1413-1421
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• 2000

In this paper, we analyze previous flow control algorithm for serving ABR traffic, and then propose the algorithm which calculate fair transmission rate and control efficiently ABR traffic using VS/VD switch which has an effect on WAN environment with long delay. For getting the transmission rate, the proposed algorithm use FMMAR as ER scheme which calculate exactly the fair share. And, in large delay state. we can obtain fair cell sharing by calculating transmission rates which obtained by transmitted queue length information of VD to VS for serve and drain cell in queue Through the computer simulation, we evaluate the performance of proposed algorithm. According to the results, the proposed algorithm shows good performance.

• Science of Emotion and Sensibility
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• v.7 no.4
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• pp.67-75
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• 2004

In this paper, we analyze previous flow control algorithm for serving ABR traffic, and then propose the algorithm which calculate fair transmission rate and control efficiently ABR traffic using VS/VD switch which has an effect on PNNI environment with long delay. For getting the transmission rate, the proposed algorithm use FMMRA as ER scheme which calculate exactly the fair share. And, in large delay state, we can obtain fair cell sharing by calculating transmission rates which obtained by transmitted queue length information of VD to VS for serve and drain cell in queue Through the computer simulation, we evaluate the performance of proposed algorithm, According to the results, the proposed algorithm shows good performance.

• Journal of Korea Multimedia Society
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• v.5 no.3
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• pp.316-322
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• 2002

In this paper we consider continuous block allocation scheme of UNIX file system to support real time retrieval service. The proposed block allocation scheme is designed to place real time data at appropriate disk block location in considering the consume-rate that is given with real time data. To effectively determine the disk block location we analyze the relationship between consume-rate and the two variable factors that are the number of continuous blocks and the cylinder distance of logically consecutive data. In traditional UNIX block allocation scheme it is in fact impossible to find continuous free disk blocks in a specific cylinder location. Thus we propose new bitmap-based free block allocation scheme that enables to determine whether a block in specific cylinder location is free state, or not.

• Journal of the Korean Society for Library and Information Science
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• v.36 no.2
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• pp.5-24
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• 2002

The purpose of this study is to describe the information environment of ST information users in Korea by examining their needs and satisfaction for documents. Comparison was made between the statistics of KISTI DDS and NACSIS-ILL document copy service, and data from the survey conducted for KISTI's ST information users in 2001 were analyzed. Findings include the low demand for documents delivery, low success rate in obtaining documents from domestic institutions, including KISTI, relatively high reliance on foreign DDS institutions, and difficulties in getting documents with speed, timeliness, and cost-effectiveness. It seems urgent to implement the strategic plans for more comprehensive and well-organized collection development and resource-sharing, and improvement of DDS.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.1
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• pp.49-54
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• 2019

Since the underwater communication environment, which is used mainly in acoustic channel, is different from terestrial communication, it needs to analyze the appropriate transmission performance in underwater environment to implement the communication services. Appropriate traffic process method for a communication service is required through transmission performance of object traffic for the communication service. In this paper, transmission performance of video traffic on underwater MANET(Mobile Ad-hoc Network) is analyzed and video traffic configuration scheme on underwater MANET with results of performance analysis is suggested, This study is done with computer simulation based on NS(Network Simulator)-3. throughput, transmission delay, packet loss rate is used for transmission performance.

• Journal of Families and Better Life
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• v.13 no.3
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• pp.1-13
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• 1995

우리나라의 이혼율이 최근급격한 증가추세를 보이고 있음에도 불구하고 우리나라의 이혼에 대한 연구는 매우 적은 실정이며 특히 여러변수와 이혼과의 관계를 살펴본 연구는 찾아보기 어렵다. 이에 본 연구에서는 사회적 행동에 영향을 많이 미치는 것으로 알려져 있 는 사회경제적 지위와 이혼율과의 관계를 살펴보았다. 통계청에서 집계힌 자료중에 이혼과 수입과의 관곌계를 알수 있는 자료가 없었으므로 본 연구에선 교육 직업과 이혼과의 관계만을 살펴보았다. 교육수준별 직업별로 이혼상태에 있는 사람들의 비율을 비교한 결과는 다음과 같다. 교육수준별 이혼상태율을 보면 (1980, 1990년의 자료를 분석) 남자의 경우 교육수준이 높을수록 이혼상태의 비율이 낮아진다. 여자의 경우 교육수준이 높아지면서 점점 이혼상태의 비율이 높아지다가 다시낮아지는 고선형의 관계를 보인다. 남녀모두 모든 교육수준에서 중퇴자들이 졸업자들보다 높은 이혼비율을 보이고 있다. 연령으로 통제한 후에도 이러한 경향에는 별변함이 없다 직업별 이혼상태율을 비교하면(1970, 1980, 1990년의 자료를 분석) 남성들의 경우 직업군의 지위가 높을수록 이혼상태율이 낮아진다. 여성들의 경우 직업적지위가 높은 경우와 낮은 경우가 불규칙하게 이혼비율이 분포되어 있어 일반적 경향을 찾기가 어려우나 가장낮은 이혼율을 보인 직업과 가장높은 이혼율을 보인 직업은 세시기에 일관성 있게 나타났다. 농/축/임업/수산업/수렵업에 종사하는 경우 이혼비율이 가장낮게 나타났고 서비스직에 종사하는 경우 다른 직업군에 비해 현저하게 이혼비율이 높게 나타났고 연령으로 통제한 후에도 같은 경향을 보인다.

• The KIPS Transactions:PartC
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• v.9C no.2
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• pp.283-292
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• 2002

This paper develops a scheme of resource management for guaranteeing QoS of realtime traffic in wireless mobile internet environments Mobile terminal has significant impact on the QoS originating mobility provided to a real-time application. The currently proposed MRSVP is not clear the boundary of resource reservation tregion and also can give rise to signal overhead to maintain sessions. To solve above problem, we propose the new reservation protocol, mobile cluster based H-MRSVP to combine MRSVP with moving cluster concept. In this paper, we analytically design our model for guaranteeing the QoS of realtime traffic and compare the three schemes: guard channel allocation schemes, DCA and our model. The performance measures are the probabilities of new call blocking, handoff dropping, resource utilization and service completion versus the system offered Erlang load. Consequently, Simulation indicate our model is more flexible than DCA in a view pint of channel utilization and gains the advantage over guard channel scheme with respects to the mobility.