• Proceedings of the Korea Information Processing Society Conference
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• 2015.04a
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• pp.87-89
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• 2015

최근 빠른 속도와 사용자의 증가로 VoIP 기술에 대한 관심이 높아지고 있다. 본 논문에서는 VoIP의 개요와 VoIP 환경에서 전송 품질에 영향을 주는 요소인 지터의 정의와 지터를 개선하기 위한 지터 버퍼에 대해 설명한다. 지터 버퍼는 크게 고정형과 적응형, 두 가지로 나누어지며 지터 버퍼에 대한 분석을 통해 지터 버퍼 성능 향상 방안을 제안한다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.7
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• pp.3238-3246
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• 2013

The progress of Information Technology enables people can communicate each others using the Internet. As a smartphone proliferates, many free mobile VoIP(Voice over IP) application are developed and accepted by smartphone users. In this study we investigate the factors affecting the acceptance of mobile VoIP applications and the structural relationship among these factors. We review the related works and extract the related factors and build a research model describing the causal relationship among these factors. We conduct an empirical study - a survey and statistical analysis - to verify the research model. EFA(Exploratory Factor Analysis) is applied for variables in the survey and SEM(Structural Equation Model) is used to reveal the structural relationship among the factors. We can find that two factors - usefulness of mobile VoIP and social influence - positively affect usage intention and actual use. These findings imply that it is required to emphasize the benefits of mobile VoIP use and add S/W functionalities enhancing social influence.

• Convergence Security Journal
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• v.7 no.3
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• pp.109-120
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• 2007

VoIP service provides various functions that PSTN phone service hasn't been able to provide. Since it also has superiority in service charge, the number of user is increasing these days. When we think of the other side in cost aspect, the spam caller can also send his/her commercial message over phone line using more economic way. This paper presents the characteristics that should be considered to detect the spam call using greylisting method. We have explored static and dynamic characteristics in VoIP calls, and analyzed the relation among them. Especially, we have surveyed the authentication and charging method of Korean VoIP service provider. We have analyzed each charging method using our spam call simulation result, and derived the charging method that can be favored by spam caller. The contribution of the work is in analysis result of static aspect for SPIT Level calculation in greylisting method.

• The KIPS Transactions:PartC
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• v.13C no.5 s.108
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• pp.659-668
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• 2006

Various schemes for mobility support are currently proposed in NGN. However the performance comparison of all existing schemes is not relatively examined as yet. Therefore, in this paper, we investigate the location registration and handover procedure of MIPv6, IP2, Q.MMF, IMS, compare and analyze the location registration time and cost and handover latency time using various performance parameters and simulation for the performance analysis. As a result of analysis, when Location Manager locates in the center of core network, IP2 showed better performance than other schemes.

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.47-50
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• 1998

In recent years, it is required that computing support mobile user with computer. The advantage of mobile computing is that users may access all their applications from any location, whether they are in another building or a different state. So, Internet combines with mobile computing technology to make new communication environment for supporting mobility. The research for solving the problem of mobility is actively in progress. This paper describes the implementation of tunneling method for flexible bypass between specific region. Tunneling method provide mobile service to mobile hosts. IP datagram's address tranform method is IP-within-IP encapsulation by which an IP datagram may be encapsulated within an IP datagram. The developed IP-within-IP protocol can provide not only enhanced performance because it is implemented in kernel mode, but also convenience of usage to the application developers because it gives user interface as a dynamic link library. Verification of IP packet tunneling was text file transfer program.

• Journal of Korea Multimedia Society
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• v.7 no.1
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• pp.106-112
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• 2004

Mobile IP is a solution for mobility on the global Internet. However, it causes service delay incase of frequent movement of mobile node and mobile users. Mobile IP regional registration is Proposed to reduce the service delay. In this paper, we introduce an optimal regional location management mechanism for Mobile IP that reduces the registration delay. The movement of mobile node is described by a discrete analytical model. The proposed model explains analytically average packet rate and registration cost as the size of regional networks with mobility of mobile node.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.9
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• pp.2300-2305
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• 2009

Recently, Telecommunication companies have introduced a new network architecture that assigns network resources consistent and protects their systems more secure. Now, they provide multimedia services through various types of access networks. In this study, I'd like to introduce IP address assignment method based on the Dynamic Host Configuration Protocol (DHCP) and find out how success or failure of Ip address assignment will be taken place according to the booting order of xDSL modem, AP and PC.

• International Journal of Internet, Broadcasting and Communication
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• v.11 no.3
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• pp.59-63
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• 2019

VoIP technology is a technology for exchanging voice or video data through IP network. Various protocols are used for this technique, in particular, RTP(Real-time Transport Protocol) protocol is used to exchange voice data. In recent years, with the development of communication technology, there has been an increasing tendency of services such as "Kakao Voice Talk" to exchange voice and video data through IP network. Most of these services provide a service with security guarantee by a user authentication process and an encryption process. However, RTP protocol does not require encryption when transmitting data. Therefore, there is an exposition risk in the voice data using RTP protocol. We will present the risk of the situation where packets are sniffed in VoIP(Voice over IP) communication using RTP protocol. To this end, we configured a VoIP telephone network, applied our own sniffing tool, and analyzed the sniffed packets to show the risk that users' data could be exposed unprotected.

• Journal of Life Science
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• v.31 no.4
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• pp.410-417
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• 2021

Next-generation sequencing (NGS) is a high-throughput technique for sequencing large numbers of DNA fragments that are prepared from a genome. This sequencing technique has been used to elucidate whole genome sequences of living organisms and to analyze complementary DNA (cDNA) or chromatin immunoprecipitated DNA (ChIPed DNA) at the genome level. After NGS, the use of proper tools is important for processing and analyzing data with reasonable parameters. However, handling large-scale sequencing data and programing for data analysis can be difficult. The Galaxy platform, a public web service system, provides many different tools for NGS data analysis, and it allows researchers to analyze their data on a web browser with no deep knowledge about bioinformatics and/or programing. In this study, we explain the procedure for preparing chromatin immunoprecipitation-sequencing (ChIP-seq) libraries and steps for analyzing ChIP-seq data using the Galaxy platform. The data analysis steps include the NGS data upload to Galaxy, quality check of the NGS data, premapping processes, read mapping, the post-mapping process, peak-calling and visualization by window view, heatmaps, average profile, and correlation analysis. Analysis of our histone H3K4me1 ChIP-seq data in K562 cells shows that it correlates with public data. Thus, NGS data analysis using the Galaxy platform can provide an easy approach to bioinformatics.

• The Journal of the Korea institute of electronic communication sciences
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• v.4 no.2
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• pp.93-100
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• 2009

As the Internet Protocol be widely/rapidly used in packet communication, common carriers are providing the multimedia service(Both direction real-time voice, video conference, remote educational etc.)on the Internet. Also the 070 VoIP (Voice over IP) service is provided by the carriers on the packer network. In order to offer VoIP service in Korea, common carrier has to acquire the optimum level for QoS(quality of service). In this paper, we study on CODEC quality to get a higher QoS for VoIP.