• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.3
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• pp.201-210
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• 2019

This paper proposes the AMCS(Agricultural Machine Control System that distinguishes farms using satellite photos or drone photos of farms and controls the self-driving and operation of farm drones and tractors. The AMCS consists of the LSM(Local Server Module) which separates farm boundaries from sensor data and video image of drones and tractors, reads remote control commands from the main server, and then delivers remote control commands within the management area through the link with drones and tractor sprinklers and the PSM that sets a path for drones and tractors to move from the farm to the farm and to handle work at low cost and high efficiency inside the farm. As a result of AMCS performance analysis proposed in this paper, the PSM showed a performance improvement of about 100% over Dijkstra algorithm when setting the path from external starting point to the farm and a higher working efficiency about 13% than the existing path when setting the path inside the farm. Therefore, the PSM can control tractors and drones more efficiently than conventional methods.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.48 no.3
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• pp.41-49
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• 2011

In this paper, we propose an open protocol to be employed between a smart meter concentrator and a metering data collection server, and also evaluate its performance. Legacy concentrators performs the connection establishment and data gathering operations with DLMS/COSEM protocol standards. However, we note that there are no standardized protocols between the concentrator and the collection server, which inevitably conduces each commercial smart metering system to have its own proprietary protocol. In order to solve this problem, we propose an open protocol - Smart Meter Concentrator Control Protocol(SMCCP) by extending the existing standard protocol(DLMS/COSEM). The SMCCP can provide the proxy mode to enable efficient transmission between the concentrator and the data collection server. It also can support the relay mode to enable a direct communication between the data collection server and each far end smart meter. We also implement an emulator system and a protocol analyzer to provide its operation. In addition, we evaluate the session holding time and the link usage ratio in both relay and proxy modes with OMNET++ simulator.

• Proceedings of the IEEK Conference
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• 2001.06c
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• pp.101-104
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• 2001

Over the last few years, streaming audio and video content on Internet sites has increased at unprecedented rates. The predominant method of delivering video over the current Internet is video streaming such as SureStream or Intelligent Stream. Since each method provides the client with only one data stream from one server, it often suffers from poor qualify of pictures in the case of network link congestion. In this paper, we propose a novel method of delivering video stream based on wavelet to a client by utilizing multi-threaded parallel connections from the client to multiple servers and to provides a better way to address the scalability functionalities. The experimental results show that the video quality delivered by the proposed multithreaded stream could significantly be improved over the conventional single video stream methods.

• Journal of Communications and Networks
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• v.18 no.5
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• pp.826-836
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• 2016

Increase of hypertext transfer protocol (HTTP)-based video popularity causes that broadband and Internet service providers' links transmit mainly multimedia content. Network planning, traffic engineering or congestion control requires understanding of the statistical properties of network traffic; therefore, it is desirable to investigate the characteristic of traffic traces generated, among others, by systems which employ adaptive bit-rate streaming. In our work, we investigate traffic originating from 120 client-server pairs, situated in an emulated laboratory environment, and multiplexed onto a single network link. We show that the structure of the traffic is distinct from the structure generated by first and second generation of HTTP video systems, and furthermore, not similar to the structure of general Internet traffic. The obtained traffic exhibits negative correlations, anti-persistence, and its distribution function is skewed to the right. Furthermore, we show that the traffic generated by clients employing the same or similar play-out strategies is positively correlated and synchronised (clustered), whereas traffic originated from different play-out strategies shows negative or no correlations.

• Proceedings of the Korean Information Science Society Conference
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• 2008.06b
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• pp.371-374
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• 2008

현재 수많은 상업포탈 사이트들은 다양한 서비스를 제공하기 위해 많은 노력을 기울이고 있다. 다양한 서비스를 제공함으로써 다양한 소비자들을 더 수용하기 위해 다양한 기능들을 개발하고 있다. 이러한 기능들을 제공하기 위해 많은 양의 하이퍼링크로 연결된다. 이런 많은 양의 하이퍼링크들은 초기 서비스 웹 페이지 소스의 대부분을 차지하게 된다. 이는 웹 서버의 부하를 주는 것은 물론이고 사용자들 역시 그렇게 많은 링크 서비스를 필요로 하지 않기 때문에 많은 양의 링크들을 정리할 필요가 생긴다. 즉 사용자들이 빈도수가 높은 서비스에 대한 링크만을 연결함으로써 웹 서버의 부하를 줄이고 웹 페이지의 소스의 양도 크게 줄일 수 있다. 일반 웹 페이지의 소스를 렌더링하여 필요한 링크만 제공하는 구현을 통해 웹 서버의 성능 향상을 연구한다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 1999.05a
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• pp.290-294
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• 1999

This paper describes the design and implementation of an intranet-based message and file transfer system using the INMARSAT-C for easy transmission and user-friendly interface. For these, onboard LAN including telex, printer and database with centralized one server is designed and constructed. Also, onboard computing environment which provides the INMARSAT-C terminal and RS-232C link interface built in with effective intranet-based web mail system between the ship and land.

• Journal of the Korea Institute of Military Science and Technology
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• v.17 no.5
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• pp.637-642
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• 2014

Military communications have limited resources such as poor bandwidth and insufficient link capacity. Numerous hosts in conventional IP networks, including the Tactical Information Communication Network (TICN), the tactical communication system of the Army, focus heavy traffic on a single server via end-to-end connections and in which data delivery latency is caused by exchanging routing information. Content-Centric Networking (CCN), one framework of Information-Centric Networking (ICN), is a novel Internet paradigm in which data can be accessed by the name of the content instead of the location information. This paper provides content caching strategies for applying CCN to military tactical IP networks based on TICN environment.

• The Journal of Society for e-Business Studies
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• v.4 no.1
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• pp.21-36
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• 1999

Using user monitoring techniques on web, marketing decision makers in cyber shopping malls can gather customer behavior data as well as sales transaction data and customer profiles. In this paper, we present a marketing rule extraction technique for customer behavior analysis in cyber shopping malls, The technique is an application of market basket analysis which is a representative data mining technique for extracting association rules. The market basket analysis technique is applied on a customer behavior log table, which provide association rules about web pages in a cyber shopping mall. The extracted association rules can be used for mall layout design, product packaging, web page link design, and product recommendation. A prototype cyber shopping mall with customer monitoring features and a customer behavior analysis algorithm is implemented using Java Web Server, Servlet, JDBC(Java Database Connectivity), and relational database on windows NT.

• Proceedings of the KIPE Conference
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• 2014.07a
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• pp.195-196
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• 2014

본 논문에서는 위상 변이 LLC 공진 컨버터를 이용하여 주파수의 변동을 제한하며 링크 전압을 기변함으로써 효율을 높이고자 한다. 전부하에 걸쳐 효율이 약 0.26~0.69 만큼 상승하였고 특히나 50% 부하 조건에서는 제안 된 컨버터를 통해 titanium level 을 달성하였다. 또한 높은 링크 전압에 대해서는 위상 변이 방법을 통하여 효과적으로 전압 조정을 할 수 있음을 확인하였다.

• Annual Conference of KIPS
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• 2008.05a
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• pp.589-592
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• 2008

최근 대부분의 기업은 인터넷 웹 서비스를 하고 있고, 대부분의 인터넷 사용자들이 여러 종류의 웹 서비스를 제공받고 있다. 하지만 사용자들이 필요로 하는 서비스는 한정되어 있지만 대부분의 기업에서는 여러 가지 서비스를 제공하여 다양한 많은 사용자들의 요구를 수용하고자 한다. 그로 인해 초기 메인 웹 페지이에 많은 링크가 연결된 페이지를 제공하게 된다. 이는 초기 웹페이지의 로딩에 있어 큰 용량의 소스가 원인이 되어 다수의 사용자가 짧은 시간에 접속할 경우 서비스 오류의 원인이 되기도 한다. 또한 대부분의 사용자들이 필요로 하는 몇 개의 링크 기능만을 제공하고 니즈가 적은 링크 기능은 비활성화 함으로써 사용자 요구에 좀 더 빠르게 대응할 수 있도록 링크 맵 프로그램을 이용한 웹 시스템을 제안하고 웹 서버의 성능 향상을 연구한다.