• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.2B
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• pp.131-140
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• 2011

As the number of Internet users and applications is increasing, the importance of application traffic classification is growing more and more for efficient network management. While a number of methods for traffic classification have been introduced, such as signature-based and machine learning-based methods, Skype application, which uses encrypted communication on its own P2P network, is known as one of the most difficult traffic to identify. In this paper we propose a novel method to identify Skype application traffic on the fly. The main idea is to setup a list of Skype host information {IP, port} by examining the packets generated in the Skype login process and utilizes the list to identify other Skype traffic. By implementing the identification system and deploying it on our campus network, we proved the performance and feasibility of the proposed method.

• Proceedings of the Korea Information Processing Society Conference
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• 2009.04a
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• pp.1112-1115
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• 2009

네트워크 관리자 입장에서 효율적인 네트워크 관리를 위해 응용 프로그램 별 트래픽 분류의 중요성이 커지고 있다. 응용 프로그램 별 트래픽 분류를 위해 signature 기반, machine learning 방법들이 제안되고 있지만 p2p 방식의 Skype 응용프로그램에 대한 적용결과는 그 신뢰성이 떨어지고 있는 것은 사실이다. 본 논문에서는 Skype의 트래픽을 분류하기 위해 각 Client 마다 Skype application install 시 동적으로 변화하는 Port 를 알아내는 방법, UDP 패킷의 특정위치의 특정 signature, TCP signal flow의 특정위치 패킷에 대한 payload 크기 등을 이용한 Skype traffic 분류 방법을 제안한다. 제안된 방법론은 학내 네트워크에 적용하여 그 타당성을 TMA를 통해 검증하였다.

• Venture DIGEST
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• s.111
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• pp.40-41
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• 2007

• Research in Mathematical Education
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• v.21 no.1
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• pp.15-34
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• 2018

This paper describes how communicative technology between two classrooms located in different sociocultural contexts was used to support mathematics instruction. I analyzed what interactions emerged using the communicative technology, how sociocultural differences were leveraged to construct mathematical knowledge, and how students built this knowledge together across urban and rural classrooms. The results show that reciprocal interactions emerged. Teachers co-designed lesson plans and tasks with consideration of the different classroom social contexts. Based on those teachers' interactions, students had opportunities to justify their ideas and to prepare answers before the connected discussions, and a wide spectrum of ideas was synthesized as collaborative knowledge. These findings suggest that communicative technology has the potential to enhance learning opportunities for students across different social contexts.

• Journal of KIISE:Computing Practices and Letters
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• v.15 no.1
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• pp.21-28
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• 2009

In this paper, we consider the Femtocell based enterprise wireless network using 2G/3G/4G cellular network technologies. And, we apply the open network service API which enable an easy development of ISP or enterprise services to P2P enterprise services. Based on the proposed scheme, enterprise services can be always connected at anywhere and anytime via heterogeneous devices. By using a qualitative analysis, we evaluate the performance of the proposed scheme and compare with that of the famous P2P service - Skype. Results show that the proposed scheme requests smaller servers and flows with enhanced service quality.

• SUVANNABHUMI
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• v.14 no.2
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• pp.61-88
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• 2022

This article aims to determine the vulnerability of migrant populations to COVID-19. Between March 2020 and November 2021, informal interviews with respondents who were stranded in various parts of the world were conducted through Skype and WhatsApp. COVID-19 endangers millions of individuals who were stranded between their homes and their destinations - and who were compelled to reside in overcrowded accommodation where the ideas of "stay home," "keep safe," and "social distancing" have little significance.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.3
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• pp.569-575
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• 2014

These days as smart TVs or android set top boxes have come into wide use, VoIP(Voice over Internet Protocol) services such as the Skype which can beused on computer system, can be also accessed by smart TVs or set top boxes. and the various kinds of distance learning programs have been developed on smart TVs or set top boxes. but when users have utilized a webcam with smart TVs or set top boxes, users have to go in front of smart TVs or set top boxes In this research paper, the new technology can be solved the problem of webcam use according to chaned environment. This tech is related with the wireless webcam one which can be applicable to open spaces such as living room with some distance between user and smart TV. There are few problems in long distance the test results show high reliability in living room with some distance.

• Journal of the Korean Society for Library and Information Science
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• v.53 no.1
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• pp.83-108
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• 2019

This study investigated South Korean citizens' political communication and deliberation through Twitter during the 2014 General Election, focusing on influential opinion leaders' political information behaviors. Individual semi-structured interviews were administered with 13 opinion leaders using the multiple interview modes of email interviews, Skype interview and face to face interviews. Through the analytical lens of the theory of Information Worlds, the chosen social types and social norms of opinion leaders impacted their political information behaviors, including how they assessed, shared, exchanged, or avoided information, and, in turn, created boundaries between and around their information worlds that allowed for both conflict and synergy.

• Proceedings of the Korea Information Processing Society Conference
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• 2008.11a
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• pp.1363-1366
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• 2008

최근 Skype의 인기와 더불어 P2P기반의 VoIP에 대한 관심이 높아지고 있다. 이에 표준 콜 셋업 프로토콜인 SIP와 동등 계층 간 통신망 구성의 P2P 기술을 결합하여 분산된 VoIP 서비스를 제공하려는 연구가 활발하게 진행 중에 있다. P2P에서는 중앙 엔티티가 존재하지 않으므로 사용자의 위치정보를 효율적으로 분산시키고 신속한 검색 방법을 제공하는 것을 중요한 문제로 다루고 있다. P2PSIP에서는 파일공유 목적의 P2P 서비스와는 다르게 특정 사용자의 각종정보(위치, 프로파일 등)를 빠르고 정확하게 찾아내야한다. 분산된 사용자의 위치정보를 검색하기 위하여 주로 DHT를 사용하고 있다. 하지만 매번 새로운 접속마다 사용자의 위치를 다시 찾아야 하기 때문에 오버레이 네트워크의 트래픽을 증가시킨다. 또한, 오버레이 네트워크에 참여하는 노드의 수가 증가함에 따라 사용자의 검색시간이 길어지는 단점을 가지고 있다. 본 논문에서는 DHT로 찾아낸 사용자의 접속패턴 히스토리 정보를 캐쉬로 저장하여 호 설정 지연을 감소시키는 방안을 제안한다.

• 한국정보통신설비학회:학술대회논문집
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• 2008.08a
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• pp.97-101
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• 2008

Voice over IP is a telephone service which sends and receives the voices through the Internet. Because the infrastructure of wireless and mobile communication networks such as 3G, Wi-Fi and WiMAX has expanded, the study about Mobile VoIP, which provides the voice service from wireless network, has been actively in progress. Since Rei 6 HSPA in 3GPP and Rev A lxEVDO in 3GPP2, VoIP through the data channel is more efficient than circuit switch. It is predicted that VoIP over 4G will be more effective and 4G mobile VoIP business will be vitalized in the future. In addition, there are businesses which offer VoWLAN by using software such as Skype and Fring. They provide services which cheapen the price of international calls and long distance calls. This paper will present the Korean and other countries' mobile VoIP trends, its classification along the network connection, the study on techniques, and conditions of mobile VoIP. It also will be described a view of terminal convergence and service convergence.