• Journal of the Institute of Electronics Engineers of Korea CI
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• v.41 no.3
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• pp.47-54
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• 2004

By using wireless terminal, the number of users who wish to use the multimedia service like the Internet as well as Short Message Services and voice service has increased dramatically over the last years. We propose the method that improves Mobile IPv4 (MIPv4) Regional Registration in wireless mobile networks to decrease traffic's transmission delay and message generation compared with an existing method We design the scheme in MIPv4 environments that a packet do not pass through the home agent transmitted from correspondent node to mobile node, if a mobile node moves to other mobility agent. Simulation results show that the proposed method significantly reduces the expenses for registration and delivering packet.

• Journal of Satellite, Information and Communications
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• v.6 no.2
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• pp.84-90
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• 2011

Handling paging mechanism at the IP layer (i.e., IP paging) makes it possible to support heterogeneous wireless access technologies, providing energy-saving and reduced location registration signaling overhead over IP-based mobile networks. However, IP paging may rather cause adverse effects under active communication environments because of significant paging signaling overhead and frequent paging delay. Therefore, in order to solve these problems, a cost-effective IP paging scheme is proposed in this paper, which enables a mobile node to perform selective registration and paging based on its profile information. Numerical results indicate that the proposed scheme has apparent potential to mitigate considerable paging signaling overhead and frequent paging delay in IP-based hierarchical mobile networks.

• Proceedings of the Korea Information Processing Society Conference
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• 2011.04a
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• pp.631-634
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• 2011

IETF(Internet Engineering Task Force)는 신속하고 안전한 이동성 서비스를 위하여 네트워크 자원의 사용을 안전하게 하고 법적으로 보장하는 핵심기술 같은 많은 의미있는 작업들을 해오고 있으며 기존의 MIPv6(Mobile IPv6)에서 핸드오버 지연과 시그널링 오버헤드 같은 문제를 보완하기 위하여 HMIPv6(Hierarchical Mobile IPv6)를 제안하였다. 현재 HMIPv6에 관한 연구의 대부분은 HMIPv6와 AAA(Authentication, Authorization, Accounting) 프로토콜 사이의 상호작용 절차를 최적화하기 위한 방법에 초점을 맞추고 있다. 해당 논문에서는 AAA 절차에서 인증대기를 최소화하는데 중점을 둔 비용효율적인 계층 인증 기법을 제안한다. 이 기법에서는 MAP(Mobility Anchor Point)에 배포되어진 AAA 서버들, 그리고 홈 도메인 안에 있는 AAA 서버를 대신하는 브로커들의 계층적 AAA 아키텍처를 제안한다. 이 시뮬레이션 결과는 제안된 기법이 이전의 전통적인 인증 조합 모델링과 비교하여 핸드오프 지연과 인증대기 시간이 상당히 줄어들었음을 보여준다.

• Journal of KIISE:Computer Systems and Theory
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• v.28 no.9
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• pp.461-468
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• 2001

Though shared virtual memory (SVM) system promise low cost solutions for high performance computing they suffer from long memory latencies. These latencies are usually caused by repetitive invalidations on shared data. Since shared data are accessed through synchronization and the patterns by which threads synchronizes are repetitive, a prefetching scheme bases on such repetitiveness would reduce memory latencies. Based on this observation, we propose a prefetching technique which predicts future access behavior by analyzing access history per synchronization variable. Our technique was evaluated on an 8-node SVM system using the SPLASH-2 benchmark. The results show the our technique could achieve 34%~45% reduction in memory access latencies.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.6
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• pp.577-583
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• 2011

Radar performance test is one of the major steps for radar system design. However, it is restricted by time and cost when radar performance tests are performed with opportunity targets. So various simulated target generators are developed and used to evaluate radar performance. To simulate the target's range, most of simulated target generators are developed with optical line or DRFM(Digital RF Memory) technique but there are many restrictions such as limit of range imitation and test scenario because of their original usage. In this paper, DDL(Digital Delay Line) module for development of simulated target generator is designed with precise range simulation and easily embodiment feature. And pulse recognition and delay gap detection technique are used to simulate the time delay without distortions. Developed DDL module performances are verified through their performance tests and test results are described in this paper.

• The KIPS Transactions:PartC
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• v.11C no.2
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• pp.213-218
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• 2004

Recently MIP becomes more important for the macro mobility support in the emergence of the global system such as IMT-2000. However this Protocol suffers from many weaknesses on the location management. MIPv4 regional registration is presented for the local registration of MNs. MIPv6 can benefit from the reduced mobility signaling with external networks by employing a local MAP, that is called HMIPv6. The total signaling cost of HMIPv6 is rapidly increased by the number of CNs of an MN when the MN moves around between MAPs. In this paper, we propose a new location management scheme in MIPv6 that reduces the total signaling cost in the location update based on HMIPv6 Here the MN does not send the BU to CNs and HA when it moves around between MAPs. Instead it informs the current location by transferring the modified BU to the previous MAP. According to the results of the performance analysis, we determine the upper bound for the number of forwarding links allowed among adjacent MAPs without the BU information.

• International Commerce and Information Review
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• v.16 no.1
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• pp.247-269
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• 2014

This study is to present alternatives of strategical utilization of e-L/C in respective of transaction cost. Documentary credit is most used for trade importers' credit quality and the guarantee of the purchase price as the form of payment in export and import business dealings. The beneficiary must provide the documents required in a letter of credit in order to claim payment documents from the issuing bank, this leads to certain complexity during the procedure in practice, the preparation and the expenses of significant requirements and additional documents as well as in completing demands from the credit. In a result, there has been issues raised about the aspects of time and cost during the payment process. The outcome of such problems caused by delays in the existing trade procedure is the public to require the use of e-L/C in order to improve problems from the 'Transaction Cost' side. This study provides e-L/C's use to overcome the problems that are appearing from 'Transaction Cost' side as the aspect of time and the cost. In order to do so, we have to identify the problems in the original credit and e-L/C. Thus, provide the propose strategy of e-L/C from the Transaction Cost aspect.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.36C no.6
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• pp.9-17
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• 1999

In this paper, we propose a new technology mapping algorithm for CPLD under time constraint. In our technology mapping algorithm, a given logic equation is constructed as the DAG type, then the DAG is reconstructed by replicating the node that outdegree is more than or equal to 2. As a result, it makes delay time and the number of CLBs to be minimized. Also, after the number of multi-level is defined and cost of each nodes is calculated, the graph is partitioned in order to fit to k that is the number of OR term within CLB. The partitioned nodes are merged through collapsing and bin packing is performed in order to fit to the number of OR term within CLB. In the results of experiments to MCNC circuits for logic synthesis benchmark, we can shows that proposed technology mapping algorithm reduces delay time and the number of CLBs much more than the existing tools of technology mapping algoritm.

• Journal of the Korean Institute of Telematics and Electronics
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• v.27 no.3
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• pp.86-94
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• 1990

This paper suggests a unified packet telecommunication network, which is designed by applying network design algorithm and distribution network design algorithm, Proposed local network design algorithm is based on MST topology, and it can satisfy the limited capacity and get a distribution effect of communication flow, With the result of the comparison with Kruskal and Esau-Willams algorithm, an increase of 2.7% in cost and a decrease of 44.8% in average delay time are shown. Starting with MST topology, proposed distribution network design algorithm gradually increases its reliability, and proposes a conclusive algorithm to determine a topology with minimum cost. In compared with Cut-Saturation algorithm in the aspect of end-to-end delay time and communication flow restricted condition, this proposed algorithm results in 1/7 cost down and about 2.5 times increases in Throughput.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2006.11a
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• pp.702-707
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• 2006

There have been certain extent of material inventory in construction site because of difficulties in ordering by small quantity, strategy of securing future requirements and prevention of delay. However, carrying these inventory entails a financial cost called inventory holding cost and decrease construction productivity, so proper inventory management in construction industry is important for construction efficiency and cost reduction. This study tries to find analytical method of inventory management. It includes ordering decision which decide how much to order and when to order. Setting these strategies including deciding safety inventory, input and ouput variability are able to controled.