• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.3
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• pp.896-905
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• 2010

The sensor networks can be used attractively for various application areas. Time synchronization is important for any Ubiquitous Sensor Networks (USN) systems. USN makes extensive use of synchronized time in many contexts for data fusion. However existing time synchronization protocols are available only for homogeneous sensor nodes of USN. It needs to be extended or redesigned in order to apply to the USN with heterogeneous sensor nodes. Because heterogeneous sensor nodes have different clock sources with the SinkNode of USN, it is impossible to be synchronized global time. In addition, energy efficiency is one of the most significant factors to influence the design of sensor networks, as sensor nodes are limited in power, computational capacity, and memory. In this paper, we propose specific time synchronization based on master-slave topology for the global time synchronization of USN with heterogeneous sensor nodes. The time synchronization master nodes are always able to be synchronized with the SinkNode. Then time synchronization master nodes enable time synchronization slave nodes to be synchronized sleep periods. The proposed master-slave time synchronization for heterogeneous sensor nodes of USN is also helpful for power saving by maintaining maximum sleep time.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2008.04a
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• pp.457-458
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• 2008

• Communications of the Korean Institute of Information Scientists and Engineers
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• v.28 no.9
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• pp.55-64
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• 2010

• TTA Journal
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• s.95
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• pp.70-77
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• 2004

자동화되고 손쉽게 정보를 얻을 수 있는 RFID/USN 환경에서는 보안에 심각한 위협을 가져오며, 반대로 RFID 등의 제약된 자원에 의해 기존 정보보호 기법을 그대로 사용하기 어렵게 된다. 따라서 새로운 경량화 정보보호 기법이 연구되고 있으며, 또한 QoSS(Quality of Security Service)를 통해 제약된 자원의 활용도를 최대화 시키고자 하는 연구가 진행 중이다. 본고에서는 이러한 연구 동향에 대해 소개한다.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2006.07a
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• pp.245-245
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• 2006

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2006.07a
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• pp.365-365
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• 2006

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2006.07a
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• pp.358-358
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• 2006

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2007.04a
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• pp.175-181
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• 2007

• Information and Communications Magazine
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• v.21 no.6
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• pp.39-52
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• 2004

본 고에서는 최근 신성장 산업의 기반 기술로서 급부상하고 있는 RFID 기술의 구성 및 특성, 국내외 표준화 현황 및 파급효과를 제시함으로써 RFID 기술의 중요성과 향후 전망을 고찰한다. 특히 본 고는 RFID 기술에 대하여 기술체계 및 구성을 제시한 후 각 기술의 내용을 개념적 측면에서 소개하여 RFID/USN 기술에 익숙하지 않은 독자들에게 최근의 기술현황 및 전개에 대한 전반적인 조망을 제공하는데 그 초점을 둔다.

• Journal of the Korea Society of Computer and Information
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• v.15 no.10
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• pp.147-156
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• 2010

There are some of the studies on sensor middleware. However the standard middleware has not yet been defined. Especially, this paper focuses on the processing an intelligent service of the main functions of middleware. Several applications in the sensor network environment support not only monitoring services, but also sensor-based context-awareness and intelligent services based on sensors. However, the previous studies about USN middleware only mentioned the need for intelligent service and did not discuss the architecture and method for supporting the intelligent service in detail. Therefore this paper designs a USN middleware for providing intelligent services and proposes the method for processing the services. For this purpose, this paper proposes the Sensor-Service ontology to define the concept of services and sensors for USN applications and the relationship between them. The Sensor-Service ontology is used to infer high-level information from low-level information. To apply a variety of environmental context to intelligent services, the paper uses the rule-based reasoning. This paper implements the proposed intelligent service middleware as a prototype and then shows that the middleware can be used for a variety of USN applications through the performance evaluation.