• 대한임베디드공학회논문지
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• 제6권1호
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• pp.25-31
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• 2011

LEDs are becoming the most suitable candidate replacing traditional fluorescent street-light lamps because of its energy efficiency and high brightness. Furthermore, most countries are urging to pursue energy savings in conjunction with IT and sensor network. In order to conserve energy of LED lamp and ensure the safety of pedestrian, we propose a new smart control method for LED light system based on USN using compound sensors, such as illuminance, motion, temperature and humidity sensor. An elaborate simulation shows that the proposed system with a smart control based switching can reduce the energy by 40%, compared to the previous street-light system with a fixed time based switching.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제9권4호
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• pp.301-308
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• 2009

In the modern life, machines are used for various areas in industries as the advance of science and industrial development has proceeded. In many machines, the rotating machines play an important role in many processes. Therefore, the development of fault diagnosis and monitoring system for rotating machines is required. An ubiquitous sensor network (USN) is a combination of the key computer science and engineering area technology including the wireless network, embedded system hardware and software, communication, real-time system, etc. It collects environmental information to realize a variety of functions. In this work, a data reduction algorithm for USN based remote fault diagnostic system which can be easily applied to previously built factories is proposed. To verify the feasibility of the proposed scheme, some simulations and experiments are executed.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2014년도 춘계학술대회
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• pp.247-249
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• 2014

유비쿼터스 센서 네트워크(USN) 환경에서 센서 및 센서 노드, 그리고 센서 네트워크들은 서로 이기종으구성되며, 각 구성의 특성 또한 매우 다양하다. 그러므로 센서 및 센서 노드들 사이에 상호운용성을 위하여 단일의 메타데이터를 정의, 관리하는 것은 매우 중요하다. 이를 위해서 센서를 모델링 하기 위한 표준 언어로 SensorML(Sensor Model Language)이 있다. 본 논문에서는 센서 장치, 센서노드 그리고 센서 네트워크 정보를 응용 단에서 기술하기 위한 XMDR-DAI 기반의 USN 메타데이터를 정의한다. 그리고 제안된 XMDR-DAI 기반의 USN 메타데이터를 효과적으로 저장하고 검색하기 위한 방법은 에이전트 기술을 이용한다. 본 논문에서 제안하는 센서 메타데이터는 SensorML 기반으로써 USN 환경에서 상호운용성을 유지할 수 있을 것이며, 메타데이터 관리 시스템은 USN 미들웨어나 응용에서 메타데이터 관리를 위해 직접 활용 될 수 있다.

• Journal of information and communication convergence engineering
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• 제10권1호
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• pp.11-20
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• 2012

In a marine ubiquitous sensor network (USN) system using expensive sensors in the harsh ocean environment, it is very important to discover failures and devise recovery techniques to deal with such failures. Therefore, in order to perform failure modeling, this study analyzes the USN-based real-time water quality monitoring service of the Gaduri Aqua Farms at Songdo Island of Yeosu, South Korea and devises methods of discovery and recovery of failure by classifying the types of failure into system element failure, communication failure, and data failure. In particular, to solve problems from the perspective of data, this study defines data integrity and data consistency for use in identifying data failure. This study, by identifying the exact type of failure through analysis of the cause of failure, proposes criteria for performing relevant recovery. In addition, the experiments have been made to suggest the duration as to how long the data should be stored in the gateway when such a data failure occurs.

• Spatial Information Research
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• 제19권1호
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• pp.127-133
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• 2011

Recently, with the advances in sensor techniques and net work computing, Ubiquitous Sensor Network (USN) has been received a lot of attentions from various communities. The sensor nodes distributed in the sensor network tend to continuously generate a large amount of data, which is called stream data. Sensor stream data arrives in an online manner so that it is characterized as high-speed, real-time and unbounded and it requires fast data processing to get the up-to-date results. The data stream has many application domains such as traffic analysis, physical distribution, U-healthcare and so on. Therefore, there is an overwhelming need of a USN middleware for processing such online stream data to provide corresponding services to diverse applications. In this paper, we propose a novel USN middleware which can provide users both context-aware service and meaningful sequential patterns. Our proposed USN middleware is mainly focused on location based applications which use stream location data. We also show the implementation of our proposed USN middleware. By using the proposed USN middleware, we can save the developing cost of providing context aware services and stream sequential patterns mainly in location based applications.

• 센서학회지
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• 제17권1호
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• pp.53-60
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• 2008

Localization is the most important functions in mobile robots. There are so many approaches to realize this essential function in wheel based mobile robots, but it is not easy to find similar examples in small underwater robots. It is presented the sonar localization system using ubiquitous sensor network for a fish robot in this paper. A fish robot uses GPS and sonar system to find exact localization. Although GPS is essential tool to obtain positional information, this device doesn't provide reasonable resolution in localization. To obtain more precise localization information, we use several Ubiquitous Sensor Networks (USN) motes with sonar system. Experimental results show that a fish robot obtains more detailed positional information.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.948-951
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• 2008

Ubiquitous sensor network (USN) based on ZigBee communication protocol has been used in various application fields, such as home-network, intelligent building and machine, logistics, environmental monitoring, military field, security field and etc. The ZigBee is targeted at radio-frequency application that require a low data rate, long battery life and secure network. Especially, the USN system can be applied efficiently to building-indoor where the complex geometry is adopted. In this study, all 90 points of railway cabin indoor were monitored for temperature and humidity using USN technology. All sensors were pre/post-calibrated and the temperature/humidity change were analyzed in a railway cabin in real-time. The results would be useful to develop the cabin heating, ventilating and air conditing (HVAC) system to meet all passengers' thermal comfort regardless of their seat position.

• 한국통신학회논문지
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• 제38B권9호
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• pp.687-699
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• 2013

IP기반의 IP-USN은 6LoWPAN이라는 표준 기술을 적용하여 IPv6 USN시스템을 구축함으로써 Ubiquitous Sensor Network의 센서 존재확인과 지역적 한계의 단점을 극복한다. 하지만 USN의 노드는 관리, 비용 측면에서 주기적인 배터리 교체 없이 가능한 오랜 기간 동작해야 하는데 이를 위한 해결방안이 미비하다. 본 논문에서는 저전력으로 동작하는 최적의 IP-USN을 위해 TI사의 저전력 SoC솔루션인 CC2530과 Contiki OS를 기반으로 노드를 구성하고 IP 네트워크와 센서네트워크를 연결하는 게이트웨이를 설계 및 구현하여 6LoWPAN을 지원하는 IP-USN을 구현한다. 또한 구현된 시스템의 에너지 소비량을 측정 및 분석하여 독립전원 공급을 위한 방안을 모색한다.

• 정보통신설비학회논문지
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• 제9권3호
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• pp.102-106
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• 2010

Recently process industries from oil and gas procedures and mining companies to manufactures of chemicals, foods, and beverages has been exploring the USN (Ubiquitous Sensor Networks) technology to improve safety of production processes. However, to apply the USN technology in the large-scale plant industry, reliability and security issues are not fully addressed yet, and the absence of the industrial sensor networking standard causes a compatibility problem with legacy equipment and systems. Although this situation, process industry such as energy plants are looking for the secure wireless plant solution to provide detailed, accurate safety monitoring from previously hard-reach, unaccordable area. In this paper, SPSF (Smart Plant Safety Framework based on Reliable-Secure USN) is suggested to fulfill the requirements of high-risk industrial environments for highly secure, reliable data collection and plant monitoring that is resistant to interference. The SPSF consists of three main layers: 1) Smart Safety Sensing Layer, 2) Smart Safety Network Layers, 3) Plant Network System Layer.

• 한국산학기술학회논문지
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• 제13권11호
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• pp.5518-5524
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• 2012

오늘날 세계는 다양한 패러다임과 기술이 발전하는 시대에 도래해 왔고 여러 분야의 기술이 융합되어 새로운 분야의 기술이 나타나고 있다. 그 중 하나인 u-Health 시스템은 USN(Ubiquitous Sensor Network) 기반의 여러 생체 센서의 데이터를 이용하여 사용자가 언제 어디서든 모니터링을 할 수 있는 시스템을 말한다. 이러한 u-Health 시스템은 과거에 유선으로 센서 데이터를 수집하고 PC(Personal Computer)만으로 모니터링이 가능했지만, IT기술이 발전함에 따라서 센서 데이터를 무선으로 취득하고, 언제 어디서 모니터링이 가능한 시스템으로 변화되고 있다. 본 연구는 사용자의 생체 데이터를 취득하고 이 정보를 Jena 추론 서비스를 통해 사용자가 응급 상황이 발생하면 언제 어디서든 사용자의 생체 데이터를 확인 할 수 있도록 웹 서비스와 스마트폰 애플리케이션을 제공하는 방법을 제공한다.