• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.1
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• pp.197-203
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• 2010

The problem of location awareness in wireless sensor networks where nodes use GPS (Global Positioning System), remains challenging problem, when considering the required large energy consumption during the localization phase. In this paper we designed hardware for GPS based localization and propose a framework, called ELS, to consume low cost energy. In the ELS framework, sensor nodes are equipped with GPS. Because GPS spends large energy for position awareness, conventional localization algorithms cannot use GPS-device. We try to find a solution for efficient energy expenditure of GPS. Finally, we derive optimal transmission power of GPS data and a scheme of localization through experiment and simulation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.1B
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• pp.53-61
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• 2010

M2M Platform is the future ubiquitous network technologies which provide the integrated service with the networks and devices. It requires the standardized message protocols among the sensor applications. In this study, we developed the message protocols that support the data abstraction and interoperability among application systems with characteristics of sensor systems. The message protocols consist of the data representation formats and data exchange functions.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.6
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• pp.1134-1141
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• 2008

As sensor network technologies developed, the sphere field of application is escalated unfortunately, the applicable size is smaller than the actual quantity of cattle in feedlot. In this paper, we simulated and evaluated biological data transmission performance of virtual cattle feedlot. Deducted conclusions show us a more efficient cattle control scenario is required and effective routing protocol design and modification are needed.

• KSCI Review
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• v.14 no.2
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• pp.123-127
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• 2006

In this paper, we designed and implemented home gateway system for remote control of home appliances and devices using cellular phone. The system communicate home devices through Zigbee protocol and home server based on Linux operating system communicate cellular phone through external networks. We expect that the system apply various fields as home automations, home network, smart offices, and ubiquious environments.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.05a
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• pp.856-858
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• 2013

The data which is sensed on USN(Ubiquitous Sensor Network) environment is concerned with personal privacy and the secret information of business, but it has more vulnerable characteristics, in contrast to common networks. In other words, USN has the vulnerabilities which is easily exposed to the attacks such as the eavesdropping of sensor information, the distribution of abnormal packets, the reuse of message, an forgery attack, and denial of service attacks. Therefore, the key is necessarily required for secure communication between sensor nodes. This paper proposes a KDPC(Key Distribution Protocol based on Cluster) using ECDH algorithm by considering the characteristics of sensor network. As a result, the KDPC can provide the safe USN environment by detecting the forgery data and preventing the exposure of sensing data.

• The Journal of the Korea Contents Association
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• v.7 no.11
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• pp.1-8
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• 2007

The Sensor Network enables many distributed systems to be unmanned and automated by using of diverse sensors as well as wireless communication technologies. One of major enabling technologies for the sensor network is the USN middleware which plays the role of collecting and analyzing of measurements of sensors and controlling of the environments. The paper deals with the fungus cultivating environment based on Sensor Networks. Especially, we focus on the design of USN middleware for the embedded system, and explain how to design software architecture in terms of architectural patterns. In this design process, the improvement of methodology for pattern-oriented architecture design is proposed and the quality attributes for the architecture design is newly classified and suggested for the reference of software architecture design.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.8
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• pp.1955-1961
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• 2009

As a core technology realizing ubiquitous world, recent researches are being concentrated to wireless sensor network. However, most research results were focused to the sensor network technology itself, even though interworking between the sensor network and Internet is also one of primitive requirements for ubiquitous world. In this paper, we design the tiny TCP/IPv6 profile which makes it possible to inter-connect the sensor network device to IPv6 based Internet. To confirm operation of the designed profile, we experimentally implemented and evaluated minimum TCP/IPv6 based on TinyOS. The evaluation result shows that throughput of our tiny TCP/IPv6 is almost same as that of TinyOS component.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.05a
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• pp.313-316
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• 2009

A novel approach for electrocardiogram (ECG) analysis within a functional sensor node has been developed and evaluated. The main aim is to reduce data collision, traffic over loads and power consumption in healthcare applications of wireless sensor networks (WSN). The sensor node attached on the patient's bodysurface around the heart can perform ECG analysis based on a QRS detection algorithm to detect abnormal condition of the patient. Data transfer is activated only after detected abnormality in the ECG. This system can reduce packet loss during transmission by reducing traffic overload. In addition, it saves power supply energy leading to more reliable, cheap and user-friendly operation in the WSN based ubiquitous health monitoring.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.1023-1026
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• 2005

In the ubiquitous computing environment, an intelligent vehicle is defined as a sensor node with a capability of intelligence and communication in a wire and wireless network space. To make it real, a lot of problems should be addressed in the aspect of vehicle mobility, in-vehicle communication, common service platform and the connection of heterogeneous networks to provide a driver with several intelligent information services beyond the time and space. In this paper, we present an intelligent information system for managing in-vehicle sensor network and a vehicle gateway for connecting the external networks. The in-vehicle sensor network connected with several sensor nodes is used to collect sensor data and control the vehicle based on CAN protocol. Each sensor node is equipped with a reusable modular node architecture, which contains a common CAN stack, a message manager and an event handler. The vehicle gateway makes vehicle control and diagnosis from a remote host possible by connecting the in-vehicle sensor network with an external network. Specifically, it gives an access to the external mobile communication network such as CDMA. Some experiments was made to find out how long it takes to communicate between a vehicle's intelligent information system and an external server in the various environment. The results show that the average response time amounts to 776ms at fixed place, 707ms at rural area and 910ms at urban area.

• Journal of Korea Multimedia Society
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• v.9 no.11
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• pp.1474-1482
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• 2006

Recently, it is advanced about the variable research of IPv6 and the wireless sensor network. However, the existed researches are not enough about the internetworking technology between the wireless sensor network and the Internet based on IPv6 for supporting ubiquitous service. Accordingly, this paper proposes two internetworking models for connecting the wireless sensor network and Internet based on IPv6. The relay router in the first model and the sink node of the wireless sensor network in the second mode] were used as a gateway. Then we analyze and compare with two internetworking models. Additionally we construct the test-bed connected between the wireless sensor network and KOREN(KOrea advanced REsearch Network) based on IPv6 using the first model. And we verified the operation of the test-bed by experiments.