• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2005.04a
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• pp.363-366
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• 2005

유비쿼터스 컴퓨팅에서 사용자에게 필요한 서비스를 지능적으로 제공하기 위해서는 컨텍스트 정보의 효과적인 필터링이 필요하다. 현재까지 사용되고 있는 필터링 기술은 온라인상에서 사용되는 사용자 정보를 기준으로 서비스를 제공하고 있다. 하지만 휴대용 유$\cdot$무선기기에서 컨텍스트 인식에 기반을 둔 서비스를 제공하기 위해서는 복잡한 필터링과정과 큰 저장 공간이 요구된다. 따라서 본 논문에서는 사용자 주변에 널려 있는 센서를 통해 입력된 컨텍스트 정보들을 효율적으로 필터링하여 사용자에게 필요한 서비스만을 제공하도록 하였다. 이를 위해서 기존의 P2P 모바일 에이전트에서 사용되는 협력적 필터링 기술에 Naive Bayesian 알고리즘을 혼합한 컨텍스트 협력적 필터링 알고리즘을 제안한다.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.10
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• pp.57-66
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• 2010

Today the various types of communication and application service are provided by the development of Internet and IP technologies. It is expected to be extended the service domain of two networks through the interconnecting P2PSIP overlay which is highlighted as an important technologies for Internet based services and IMS(IP Multimedia Subsystem) which is the new architecture adopted in the evolution of NGN. Therefore, this paper explains the possible methods of the service expansion with interconnecting P2PSIP overlay and IMS network. Specially this paper suggests the interconnection architectures of P2PSIP overlay and IMS network as subscriber's types and analyzes the traffic analysis model and session set up delay characteristics by simulation model. As a results, this paper shows that the interconnection architecture using gateway AS(Application Server) is the excellent method to interconnect the IMS in case of P2PSIP overlay only subscriber, and that interconnection architecture using I-CSCF is good method to interconnect the IMS in case of P2PSIP overlay and IMS subscriber.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.1B
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• pp.56-66
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• 2009

In the traditional Server/Client architecture, the client connects to the known servers and gets information through web searching. However, nowadays, diverse internet devices providing services (get) working on internet easily. The update interval of the services or information provided by the devices is relatively short. And also they tend to be both a server and a client. In this situation, the way of the traditional information searching such as web searching is not appropriate. In this paper we propose a service push model, where it pushes its service profiles to all the other network devices by broadcasting them on the network. When a device connects to the network newly, it can get all service profiles in the network and it gets service profiles newly pushed by service providers in prompt. Also it can call any service among the service profiles within itself. We implemented a prototype system for the service push model on the JXTA platform based on P2P network. Also we measured the service profile pushing delay, the service discovery time, and the response time of service execution by running test applications written on the prototype system.

• The KIPS Transactions:PartA
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• v.16A no.4
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• pp.227-234
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• 2009

OSGi technology has applied to Home Network, but now it is loaded into even heterogeneous devices in various domains. Therefore, it is necessary to cooperate with each other framework for offering effective services in distributed OSGi frameworks. However until now, OSGi specification doesn't provide any methodthat can share the services registered on remote OSGi frameworks. In order to solve this problem, there have been several researches that used existing distributed middleware technologies such as JXTA and Web Services. However these technologies have some weakness, that is, they consume lots of computing resources and need additional process to transform the services. A middleware called R-OSGi uses only OSGi technology for sharing remote OSGi services, but R-OSGi may have a communication bottleneck and SPOF (Single Point of Failure) problem, because it has a central service registry. In this paper we present RSP (Remote Service Provider), which is a P2P-based effective service sharing scheme on distributed OSGi framework. RSP doesn't need to install additional software nor have the additional transformation process of the service representation, because it uses only OSGi technology. In addition it doesn't have any bottleneck problem and improves scalability by providing the service discovery mechanism using P2P. RSP can also access remote services transparently and it can guarantee reliability by sending an immediate notice about changes of the remote services.

• Journal of Digital Contents Society
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• v.7 no.2
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• pp.89-94
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• 2006

It can be said that P2P means the pattern that every linker could be both a supplier and a customer by means of the direct connection and survey with personal computers out of the concept of server and client. P2P business has been a great impact all over the world. for it came to be possible as the express internet log-on service is getting widely used and the user environment is getting better with the supply of high-tech computer. Recently the various system of P2P has been developed not as the only service of file share between the personal users but as the application of the electronic trade between the companies. This study is to suggest the most effective system that has the function of complement of P2P.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.3
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• pp.511-521
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• 2012

JXTA technology is a set of open protocols that enable any connected device on the internet or MANET(Mobile Adhoc NETwork) to communicate in a P2P manner. In this paper, we present a JXTA-based smartphone collaborative application. For this, we define the core services and collaborative services necessary for a P2P network, and design proper protocols to support the services. The developed application provides the effective environment for group works in smartphones, supporting the various virtual workspaces. Since application supports the group works among users in close-range without relying on the mobile network, it could be very useful in various situations such as the disaster area.

• Culinary science and hospitality research
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• v.22 no.7
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• pp.148-157
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• 2016

This study verified the effects of the quality characteristics of dessert cafes by business start-ups according to dietary life styles of consumer. Data was collected over 15 days starting from April 15, 2016 from 218 customers who visited dessert cafes. In brief, the research results are as follows. First, in order to verify the influence of service quality of dessert cafes according to dietary life styles, 3-kinds of variables, namely taste-pursuing type, convenience-pursuing type, and health-pursuing type, were set up for the lower variables, and 2-kinds variables, specifically credibility and sympathy, were established for service quality as dependent variables. The results of the regression analysis showed that, taste-pursuing type (${\beta}=.371$, p<.001), convenience-pursuing type (${\beta}=.401$, p<.001), health-pursuing type (${\beta}=.474$, p<.001), all 3-kinds of dietary life style, had a significant, positive(+) corelation ton the credibility of service quality. in addition, regression analysis revealed that the sympathy type of service credibility and, all 3 dietary lifestyle types, taste-pursuing type (${\beta}=.145$, p<.001), convenience-pursuing type (${\beta}=.208$, p<.001), health-pursuing type (${\beta}=.236$, p<.001), showed a significant, positive (+) corelation. Second, as a result of verifying the effects of service quality on customer consuming behaviors at dessert cafes, it was determined that there was a significant, positive (+) corelation with credibility and sympathy in consuming behaviors such like credibility (${\beta}=.313$, p<.001), sympathy (${\beta}=.228$, p<.001).

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.2B
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• pp.137-145
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• 2006

In this paper, we propose a multicast P2Patching technique in the application layer. The P2Patching technique serves VOD stream effectively with Patching in P2P environment. The P2Patching provides multicast tree construction technique that reduces the server load and minimizes the start delay with extended multicast technique. And we provide a fast recovery technique by tree failure and dynamic buffering scheme that guarantees the continuous streaming by frequent tree disconnections. Comparing the method with that of $P2Cast^{[12]}$, we obtained the better performance by our scheme in terms of average join count, service rejection probability, tree recovery failure and buffer starvation. The average about 16$\%$ of the improvement is shown by the simulation. Most of all, the performance of buffer starvation and average join count shows a significant improvement than that of P2Cast.

• Proceedings of the Korean Information Science Society Conference
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• 2005.11a
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• pp.943-945
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• 2005

P2P 환경에서의 파일 공유 방식은 클라이언트/서버 방식과는 다르게 값비싼 서버를 사용하지 않고 클라이언트 컴퓨터들만을 사용하여 자료의 공유 및 관리를 분산시킨다. 이러한 이유로 대용량의 서버를 사용하는 클라이언트/서버 방식에서 발생하는 인적, 물적 자원의 낭비를 최소화 할 수 있다. 또한 사용자의 수가 늘어날수록 연산, 협업의 성과가 높아지는 등의 혜택을 제공한다. 이와 같은 이유로 인해 많은 사람들이 P2P에 관심을 갖고, 또한 현재 각광받고 있는 모바일 관련 분야에도 P2P를 이용한 연구들이 활발하게 진행되고 있다. 모바일 P2P 서비스란 서버의 중개 없이, 서버에 접속해 있는 한 모바일 클라이언트에서 다른 모바일 클라이언트로 다양한 정보 및 데이터를 전송하는 방식으로, 종래의 P2P 개념을 모바일 기반으로 확장한 것이다. 본 연구에서는 모바일 P2P 서비스를 영농정보 공유, 재해 정보의 통계 및 분석을 위한 프로그램에 응용하였다.

• Information and Communications Magazine
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• v.27 no.10
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• pp.35-42
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• 2010

미래 인터넷은 하부 네트워크 인프라를 바탕으로 그 위에 논리적 네트워크를 구성하는 오버레이 네트워크에서의 서비스가 대부분이 될 것이다. 이러한 오버레이 네트워크의 핵심적인 부분이 P2P 가술이다. P2P 기술은 기존의 클라이언트-서버 개념과 달리 단말들이 서로 연결되어 자원을 공유하여 참여함으로써 서버 기능과 클라이언트 기능을 동시에 수행하는 기술이다. 서비스 오버레이 구조에 대한 표준화는 IEEE P1903(NGSON)에서 진행 중이다. 이와 관련된 세부 기술인 P2P 기술에 대하여는, IETF의 P2PSIP, LEDBAT, ALTO, PPSP, DECADE 등의 워킹 그룹에서 보다 심도 있게 표준화를 진행하고 있다. 본 고에서는 IETF의 P2P 관련 워킹 그룹들의 표준화 현황 및 그 핵심 기술에 대해 살펴보고자 한다.