• Proceedings of the Korea Society for Simulation Conference
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• 2005.05a
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• pp.139-143
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• 2005

The P2P is a network environment supporting data exchange which is directly connected peers without limit of existing server-client and intervening central server for resource or offered service with each peer. JXTA is a representative of P2P system. JXTA is a typical distributed computing model that proposed by Sun Microsystems. JXTA that doesn't require centralized services or resources is adaptable in extreme changes of network organization. MANET(Mobile Ad Hoc Network) is a representative wireless network that is composed of mobile nodes without infrastructure. So MANET establishes the path for the communication of each peers and maintains the newest routing information by exchanging routing information. In this paper, we propose a technique of JXTAMAUET which implements JXTA which is the P2P network system from the wireless network which is becoming the foundation of ubiquitous computing. For the performance evaluation of the JXTAMANET, we use simulation.

• Journal of the Korea Society of Computer and Information
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• v.8 no.3
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• pp.138-143
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• 2003

With information communications and network environments merged wire/wireless networks are generalized. In this viewpoint, WAP is used by communication protocol for the data communication in the field of wireless environment. WTLS developed for the secure communications optimize TLS adapted wireless environment in the TCP/IP internet protocol. But WTLS denote WAP security problem, end-to-end problem, and power consumption, etc. Therefore in this paper we proposed WTLS cryptographic algorithm eliminated WTLS disadvantages. Proposed algorithm solved power consumption, calculated complexity, and security problems because it is not unique but hybrid form.

• Proceedings of the Korean Society of Computer Information Conference
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• 2012.07a
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• pp.59-61
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• 2012

최근 고정된 네트워크가 아닌 센싱 노드를 기반으로 한 유비쿼터스 센서 네트워크의 관심이 높아지고 있는 추세이다. 센서 네트워크에서는 넓은 지역의 정보 수집이나 망 기반시설이 갖추어 지지 않은 곳의 정보 수집 및 가공과 통신을 위하여 배터리로 구동되는 센싱 노드를 사용한다. 배터리로 구동되는 센싱노드는 통신을 위해 저전력을 사용하기 때문에 근거리 통신만 가능하다. 이러한 거리 제약을 극복하기 위해 멀티 홉 릴레이 기능을 이용한 이동 Ad-hoc 네트워크가 많이 사용된다. 본 논문에서는 이동 Ad-hoc 네트워크에서 운용되어지는 프로토콜과, 기존 망과의 연동을 위해 쓰이고 있는 기술에 대해 알아보고, 이동 Ad-hoc 네트워크상에서의 보안 기술을 고찰 하고자 한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.16 no.12
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• pp.1417-1422
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• 1991

In this paper we develop an analytic model for end-to-end communication protocols and study the window mechanism for flow control in store-and-forward computer networks. We develop a flow control model in which the parameters of the system are not dynamically adjusted to the stochastic fluctuation of the system load. Simulation results are presented and it is shown that the throughput-delay performance of a network can be improved by proper selection of the design parameter, such as timeout, the number of retransmission, etc.

• Journal of Communications and Networks
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• v.17 no.2
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• pp.118-125
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• 2015

In this paper, we propose a method to reduce mobile social network services (SNSs) traffic using a mobile integrated SNS gateway (MISG) to improve network communication performance between the mobile client and SNS servers. The gateway connects the client and SNS servers using the contents adapter and the web service adapter and helps to improve communication performance using its cache engine. An integrated SNS application, the user's client, communicates with the gateway server using integrated SNS protocol. In addition, the gateway can alert the client to new SNS contents because of the broker server implemented by the message queuing telemetry transport protocol. We design and develop the modules of the gateway server and the integrated SNS application. We then measure the performance of MISG in terms of content response time and describe the result of the experiment.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.8B
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• pp.1251-1258
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• 2010

Major utilities have been focusing on R&D and business of AMI system which plays a vital role in SmartGrid whose concept is to optimize energy efficiency with exchanging real time information between utilities and consumers based on IT technologies in power grid. In this paper, we introduce KEPCO's AMI business plan, the AMI System architecture, designed core devices, communication networks and value added services, and also explore technical and business characteristics of KEPCO's AMI system.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.1
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• pp.127-132
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• 2013

In this paper, we design the physical layer of Guardian modem for wireless public networks. The physical layer is composed of a dual-band RF (Radio Frequency) transceiver and a baseband-processor with quasi-orthogonal codes. The 2.4/5GHz dual-band RF transceiver can overcome the communication difficulty of dense 2.4GHz band for wireless public environment. Also the quasi-orthogonal code can reduce the required ASIC (Application Specific Integrated Circuit) design area. Finally, we analyze the performance of the developed system in viewpoint of data rate, BER (Bit Error Rate), PER (Packet Error Rate). Moreover we verify the performance of the dual-band RF communication.

• IE interfaces
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• v.22 no.2
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• pp.185-191
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• 2009

In this study, we propose an improved group location tracking scheme (GLS) called integrated GLS (IGLS) which, in addition to the group location registration of the GLS, sends an integrated group registration message to a virtual visitor location register (VVLR) instead of sending an individual group registration message. This integrated procedure of proposed scheme leads registration cost of group registration and group location registration to be reduced significantly. Numerical results demonstrate that our proposed IGLS outperforms conventional GLS and delayed GLS (dGLS). The IGLS can be applied effectively on public transportation systems such as subway, train and bus.

• Journal of information and communication convergence engineering
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• v.10 no.3
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• pp.269-275
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• 2012

In this paper, we proposed a novel location estimation algorithm based on the concept of space-time signature matching in a moving target environment. In contrast to previous fingerprint-based approaches that rely on received signal strength (RSS) information only, the proposed algorithm uses angle, delay, and RSS information from the received signal to form a signature, which in turn is utilized for location estimation. We evaluated the performance of the proposed algorithm in terms of the average probability of error and the average error distance as a function of target movement. Simulation results confirmed the effectiveness of the proposed algorithm for location estimation even in moving target environment.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.10a
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• pp.563-566
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• 2011

Smart grid electrical energy network is constructed in the additional network concept can be viewed with the power and IT. In order to build samrt grid networks the communication requirements should be defined definitely with implementing structure on communication network. In this paper, we introduces smart grid technology and network perspective on the requirements based on ITU-T standards.