• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.05a
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• pp.513-516
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• 2008

The sensor node's performance is expected to be improved and the price will be largely decreased. As USN-applied field is expanded, multiple application services are expected to be provided through one USN soon. Multiple applications be required a periodic data reporting, consecutive information monitoring, event-driven data and query-based data as the data pattern that USN is delivered. Accordingly, the mechanism which can assure QoS according to each data characteristic is required. In this paper, A proposed protocol apply the duty cycle of S-MAC protocol variably and flexible according QoS level. This method largely reduces the delay on the delay-sensitive traffic, while keeping the energy efficiency.

• Proceedings of the KAIS Fall Conference
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• 2011.12b
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• pp.529-532
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• 2011

Recently research efforts for ubiquitous technology that includes RFID(Radio Frequency Deification and sensor networks are conducted very actively The architectural framework of the USN sensor network discovery service. The survey of the USN technology is conducted on four technological visions that contain USN system technology USN networking technology and USN middleware along with the service platform, With respect to each technological division domestic and worldwide leading research projects are primarily explored with their technical features and research projects are primarily explored with their technical features and research outputs. Boasted on the result of the survey we establish a USN software model that includes data sensing, sensor data storage sensor data storage sensor data naming and sensor feed name service. This main objective of this model is to provide a reference model for the facilitation of USN application developments.

• Proceedings of the Korea Information Processing Society Conference
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• 2011.04a
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• pp.3-6
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• 2011

IT 기술의 발전에 따른 전력 사용량 증가로 인해서 친환경 재생 에너지에 대한 관심이 집중되고 있는 상황으로 다양한 재생 에너지자원 가운데 풍력에너지 개발이 전 세계적으로 급속히 증가하고 있다. 그러나 풍력발전기를 제어하는 제어기의 소프트웨어·하드웨어적인 문제로 인해 불규칙한 에너지 생산과 유지보수를 위한 비용이 증가함에 따라 최근에는 풍력제어기의 고장분석 및 고장 감내 제어에 대한 연구가 활발히 진행되고 있는 상황이다. 본 논문에서는 이와 같은 풍력발전기가 지속적으로 일정한 에너지 생산과 유지보수 절감이 가능하도록 하기 위해 풍력제어시스템 차원에서의 고장에 대해서 감내 가능한 고가용성의 미들웨어에 대한 구조를 제안한다. 풍력제어시스템의 고 가용성 미들웨어는 가상 운영체제를 기반으로 이중화 구조를 가지고 있으며, 주 운영체제에서 소프트웨어적인 고장이 발생 시 다음 우선순위의 가상 운영체제에서 지속적인 서비스를 제공할 수 있도록 각각의 가상 운영체제 환경을 관리한다.

• Proceedings of the KAIS Fall Conference
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• 2008.05a
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• pp.261-263
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• 2008

홈네트워크를 구축하기 위해서는 가정내의 홈네트워크 외에 서비스를 가정까지 전달해 주는 외부의 네트워크, 홈디지털 서비스를 구현하는 콘텐츠 및 솔루션 등 세가지 요소가 필요하며, 홈네트워크를 액세스망에 상호 접속하기 위한 홈서버 또는 홈게이트웨이 장치 등에 관한 연구하였다.

• Communications of the Korean Institute of Information Scientists and Engineers
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• v.25 no.12
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• pp.49-59
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• 2007

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2008.06a
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• pp.519-523
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• 2008

본 연구에서는 아직까지 기초적인 연구수준에 머물러 있는 지상시설물의 유지관리를 위해서 유비쿼터스 센서 네트워크(USN) 기반 지상시설물의 관리를 위한 기초연구를 수행하였다. 내용은 도시내 지상시설물중 USN 기반으로 관리가 가능한 대상 시설물을 도출하고, 관리대상 지상시설물에 적용할 수 있는 센서의 종류와 특성을 제시하였다. 그리고 관리대상 지상시설물의 지능화 레벨을 분석하여 지능화 체계를 정립하고, 이를 위한 서비스 개념도를 제시하였다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.26 no.4
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• pp.415-421
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• 2008

The purpose of this study is to provide a sensor based service model for traffic facilities in u-City through analysing the present condition of urban infrastructure, especially traffic facilities management. In order to achieve this purpose, we did a comparative analysis of internal and external situation of ITS(Intelligent Transport System) and classified service for traffic facilities to 3 categories, namely traffic flow management, traffic information offering, formation of road structure. Also, we examined technological trend of USN(Ubiquitous Sensor Network). Through this process, we present a sensor based service model of traffic facilities for building sustainable road environment.

• Journal of Information Technology Services
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• v.8 no.3
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• pp.171-184
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• 2009

Since the development of the Distributed Hash Tables (DHTs), the distributed lookup services are one of the hot topics in the networking area. The main reason of this popularity is the simplicity of the lookup structure. However, the simple key based search mechanism makes the so called "keyword" based search difficult if not impossible. Thus, the applicability of the DHTs is limited to certain areas. In this paper. we find that DHTs can be used as the ubiquitous sensor network (USN) metadata lookup service across a large number of sensor networks. The popularity of the Ubiquitous Sensor Network has motivated the development of the USN middleware services for the sensor networks. One of the key functionalities of the USN middleware service is the lookup of the USN metadata, by which users get various information about the sensor network such as the type of the sensor networks and/or nodes, the residual of the batteries, the type of the sensor nodes. Traditional distributed hash table based lookup systems are good for one sensor network. However, as the number of sensor network increases, the need to integrate the lookup services of many autonomous sensor networks so that they can provide the users an integrated view of the entire sensor network. In this paper, we provide a hybrid lookup model, in which the autonomous lookup services are combined together and provide seamless services across the boundary of a single lookup services. We show that the hybrid model can provide far better lookup performance than a single lookup system.

• Journal of the Korea Society of Computer and Information
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• v.16 no.6
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• pp.143-153
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• 2011

The goal of Ubiquitous Sensor Network(USN) environments is to provide users high quality services based on a variety of sensors. In this environment, sensor devices, sensor nodes and sensor networks are heterogeneous and have various characteristics. Therefore it is important for interoperability to define a metadata for describing USN resources. The OGC(Open Geospatial Consortium) proposes SensorML(Sensor Model Language) as a standard language for modeling sensors. However, SensorML provides a framework for describing a processing model among sensors rather than describing information of sensors. Therefore, to describe a USN metadata is not main purposes of SensorML. This paper defines a USN metadata which describes information about sensor device, sensor node, and sensor network. Also the paper proposes a method for efficiently storing and searching the USN metadata and implements a USN metadata management system based on our method. We show that our metadata management system is reasonable for managing the USN metadata through performance evaluation. Our USN metadata keeps the interoperability in USN environments because the metadata is designed on SensorML. The USN metadata management system can be used directly for a USN middleware or USN application.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.2B
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• pp.210-214
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• 2010

Standard about OID(Object Identifier) to implement on Internet is discussed at ITU-T, ISO/IEC. The OID should be stored and searched for object on Internet, which is called 'ORS(OID Resolution System)'. The ORS is made by international standard for identifying RFID code types, and in the future would be discussed for USN, u-Health, etc. Therefore, this paper describes the current status of the international standard discussing ORS concept, system structure and protocol, the present issue of the ORS used for RFID and the method for USN services.