• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.3B
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• pp.174-180
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• 2012

As the number of a smart phone user over the world surprisingly grows and a wireless Internet market expands, service requirement of a mobile terminal is increasing. However, because there is no consideration of mobility in the early standard step, it is difficult to expect to improve the service performance in handover procedure. This paper proposes a PFMIPv6 handover scheme by using probe request message and authentication message and by using buffering scheme in IEEE 802.11. In addition, we simulated this proposal scheme and verified that the proposed handover scheme is improved in terms of handover delay, and average FTP throughput during the handover period.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.12B
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• pp.1058-1065
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• 2008

In the Internet, as computer resource is developed, multimedia data request being increase more and more. It is effective way that process both high capacity-data and real-time data. Overlay Multicast is an effective method for efficient utilization of system resources and network bandwidth without using hardware customization. Overlay Multicast is an effective method for multimedia data service to multi-users. Multicast tree reconstruction is required when a non-leaf host leaves or fails. In this paper, relay-frame interval is selected as revealed network-state with jitter. In our proposal, multi-user service control algorithm gives a delay effect in multimedia request time. The simulation results show that our proposal takes shorter period of time than the other algorithms to reconstruct a similar tree and that it is a more effective way to deal with a lot of nodes that have lost their multi-user nodes.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.36S no.7
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• pp.25-33
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• 1999

This paper proposes a handover algorithm for the mobile host in order to reduce the number of unnecessary retransmissions during handover. In our proposal, the home agent buffers user data after receiving the registration request message form the foreign agent and then transmits them again after a predefined time. We also analyze the packet disordering probability between two user data under an assumption that the home agent generates all user data. One of two user data is the one which has been generated just before the home agent receives the registration request message and the other is generated just after that. Simulation results show that our proposal provides efficient handover for a mobile host by reducing the packet disordering probalility.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.36S no.1
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• pp.20-28
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• 1999

In this paper, we propose a new datagram delivery strategy at the home agent to improve the end-to-end performance by reducing retransmission overheads during handover. Changed routing might be able to cause packet disordering and this in turn could cause unnecessary retransmission at the fixed host and finally results in performance degradation. In our proposal, the home agent begins to buffer received datagrams instead of transmitting them after receiving a registration request message from the foreign agent and then transmits them again after for a certain time. Simulation results show that our proposal may successfully solve this problem at little cost.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.11
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• pp.5872-5878
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• 2013

This study provides two channel structure and two factor authentication. First, a purchasing request by Internet and then user certification and a settlement approval process by mobile communication. Second, it support that proposal protocol utilize a partial factor value of stored in users smartcard, smart phone and password of certificate. Third, storage stability is improved because certificate store in smartcard. Finally, proposal protocol satisfy confidentiality, integrity, authentication, and non- repudiation on required E-commerce guideline. In comparative analysis, Efficiency of the proposal protocol with the existing system was not significantly different. But, In terms of safety for a variety of threats to prove more secure than the existing system was confirmed.

• Journal of Korea Multimedia Society
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• v.17 no.6
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• pp.697-705
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• 2014

For enhancing network efficiency, content-centric networking (CCN) allows network nodes to temporally cache a transmitted response message(Data) and then to directly respond to a request message (Interest) for previously cached contents. Also, CCN is designed to utilize a hierarchical content-name for transmitting Interest/Data instead of a host identity like IP address. This content-name included in Interest/Data reveals both content information itself and the structure of network domain of a content source which is needed for transmitting Interest/Data. To make matters worse, This content-name is human-readable like URL. Hence, through analyzing the content-name in Interest/Data, it is possible to analyze the creator of the requested contents. Also, hosts around the requester can analyze contents which are asked by the requester. Hence, for securely implementing CCN, it is essentially needed to make the content-name illegible. In this paper, we propose content-name encoding schemes for CCN so as to make the content-name illegible and evaluate the performance of our proposal.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2006.11a
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• pp.310-316
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• 2006

Since 'Act on Private Participation in Infrastructure' were changed in January 2005, BTL(Build-Transfer-Lease) projects of Private Participation in Infrastructure was introduced in the domestic construction market for the purpose of providing public facilities with the public. Selecting the most qualified Promoter should be considered discreetly in BTL projects because BTL projects is for projects with approximately thirty year project life cycle, plan, construction, operating, maintenance and obviously the success of the project totally depends on the capability and role of Promoter. However, score for cost is likely to influence selecting Promoter to take the project. Accordingly, low bid contract with too much competition could decrease the quality of the construction plan and operating plan. Thus, this study did preliminary research and documents on problems of evaluation criteria for selecting Promoter in BTL projects, and proposed improvement factors by doing questionnaire over specialists of each field.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.8B
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• pp.769-776
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• 2006

It is important for evaluation execution about technology development. And it is necessary to settle together with technology development activity to evaluation execution. Purpose of this paper is to decide request for proposal and suitable to proposed enterprise contents about technology part in performance. Therefore let estimate the data about it. So suitable enterprise is selected through applying evaluation data to TEPM(Technology Evaluation Process Model).

• Journal of Applied Reliability
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• v.13 no.4
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• pp.287-298
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• 2013

This paper presents a case study of PSD(Platform Screen Door) system assurance based on EN50126 life-cycle stage. By applying this system assurance, the accidents related to urban light transit railway especially that caused casualties could be reduced tremendously. This case study contributes significantly to the reliability, availability, maintainability and safety of the PSD system. Request For Proposal (RFP) of a rail road operator in which required by RAMS is prepared in which to ensure all system assurance activity and safety assessment are compulsory. The step-by-step activities and related deliverables are used which include functional analysis, FMECA, hazard identification analysis, system hazard analysis, maintainability analysis, FRACAS, and finally verification and validation of the system.

• Journal of the Korean Home Economics Association
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• v.41 no.11
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• pp.113-121
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• 2003

Recently the status of oriental medicine in Korea has been more increased as the alternative medicine which overcome the limitations of western medicine. With the increased status, the development of the oriental medical doctor's gown which is distinguished from that of western medical doctor has been brought up among the oriental medical doctors' group since the middle of 1990. We carried out the former study to know the development's direction of the present oriental medical doctor's gown by the survey the requisites for the oriental medical doctor's gown which they want(OK Suh, 2002). We aim to propose the developed design of the oriental medical doctor's gown which meet their request and has honored tradition according to the data of the former survey. As the result of the production designing of the oriental medical doctor's gown considering tradition, practicality, appreciation of the beautiful etc., in our study, we could lead to distribute 800 gowns through the Association of Korean Oriental Medicine supporting by the brand of Amorepacific's Sulhasoo.