• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.10
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• pp.59-65
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• 2007

Recently, ubiquitous sensor network(USN) techniques have been applied to electric power facility management. This paper dealt with the designed and fabricated ubiquitous sensors which monitor transformers and lightning arresters installed in overhead distribution systems. The sensors consist of a 8-[bit] microprocessor unit, a wireless communication nodule specified in IEEE 802.15.4, and associated electronics. A Rogowski coil was fabricated to measure load of transformer and surge current without saturation having good linearity up to 1000[A]. A zero-phase current transformer with a high relative permeability of $10^5$ at 180[Hz] was used to detect small leakage current of $50[{\mu}A]{\sim}1[mA]$ flowing lightning arrester, and the frequency bandwidth of the module is ranges from 12[Hz] to 1.24[kHz] at -3[dB].

• The Journal of Engineering Geology
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• v.18 no.4
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• pp.511-522
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• 2008

Domestic slope related measuring system are mainly depending on manual and visual measurements and technical development for natural slopes is poor since the technology is developed focusing on artificial cut slopes. In addition, landslide with a debris flow is occurring frequently due to recent climate abnormally and heavy rains but early forecasts and prevention of disasters are in poor condition. Therefore, construction of ubiquitous sensor network (USN) capable of detecting dangers of landslide for rapid countermeasures is necessary. In this study, new measurements devices and measurement management techniques in compliance with domestic conditions are prepared by establishing ubiquitous based landslide monitoring system and standards of measurement management.

• Journal of information and communication convergence engineering
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• v.5 no.3
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• pp.254-258
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• 2007

Recently, ubiquitous computing in being actively researched and one of the main technology in ubiquitous computing environments is recognized as RFID system. The RFID system has much benefits but simultaneously has some problems such as user's privacy violation. In this paper, in order to improve the survivability of its nodes, it should build available simulation surrounding sensor nodes. Also, In the proposed cryptosystems we use a new hash function for user authentication and a stream cipher based on LFSR(Linear Feedback Shift Register) for message encryption and decryption. Moreover, each algorithm is programmed with C language and simulated on IBM-PC system and we analyze the randomness properties of the proposed algorithms by using statistical tests.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.1151-1152
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• 2008

Recently, ubiquitous sensor network forms the self-organization network, and transfers the information among sensor nodes that have computing technology ability. In this paper, we design and implement U-IT system for monitoring the safety of metro railway and underground shopping malls. For this, we implement sensor nodes to support IEEE 802.15.4 wireless communication standard using low power. Also we implement USN gateway node system to transmit the collected data from sensor nodes to database server over CDMA cellular network.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.5
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• pp.191-196
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• 2012

The tactical training system that was applied to wire at open terrain and field is no training accomplishment in conformity with battlefield situation portrayal. Therefore, this paper developed the tactical training and evaluation system for growing fruitfully that is installed as a tactical training monitoring system by USN WMN through controlled sensing interlock for collecting sensing data and guaranteed training equipment status and report training result for serviceability of manager. additionally we implemented controller for managing server of sending and manipulating of being gathered training data by sensor using USN and system as GUI methods. This system is easy for adapting new and improved protocol in order to processing many function of H/W and algorithms which is generated by controlled system is applicable easily.

• Journal of Institute of Control, Robotics and Systems
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• v.18 no.11
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• pp.1040-1044
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• 2012

We design a NCS (Networked Control System) where the communication between sensors and controllers takes place over a USN (Ubiquitous Sensor Network). In order to measure time delays between sensors and controllers in real time, we design an algorithm to measure RTT (Round Trip Time) between USN nodes, and implement it into TinyOS of USN. By using the measured time delays, we construct the Smith predictor to compensate the time delays between sensors and controllers in real-time. For the real time experiment, we simulate the dynamic plant model, controller, and USN interface using Real-Time Windows Target provided in MATLAB. The USN interface in the Simulink model consists of serial ports, which connect the plant output and controller with USN nodes. The experiment results show that the time delays between sensors and controllers are precisely measured in real time; the Smith predictor appropriately compensates the time delays; and the stability is achieved in the closed-loop of the NCS.

• Journal of Internet Computing and Services
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• v.9 no.6
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• pp.15-25
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• 2008

Due to the differences between a mobile ad-hoc network and a sensor network, the pre-existing autoconfiguration for a mobile ad-hoc network cannot be simply applied to a sensor network. But. a mechanism is still necessary to assign locally unique addresses to sensor nodes efficiently. This paper proposes a hybrid IDs assignment scheme of local area sensor networks. The IDs assignment scheme of hybrid method combines a proactive IDs assignment with a reactive IDs assignment scheme. The proposed scheme considers efficient communication using reactive IDs assignment, and security for potential attacks using zone-based self-organized clustering with Byzantine Agreement in sensor networks. Thus, this paper has solved the shortage of security due to minimizing network traffic and the problem of repairing the network from the effects of an aberrant node in sensor networks.

• The Journal of the Korea Contents Association
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• v.7 no.11
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• pp.130-139
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• 2007

As increasing the usefulness of wireless communication, there are developing the environment of ubiquitous that is combined the network of wireless and wire communication combinate type in various filed and in this network environment, u-campus constructions, based on ubiquitous sensor network, is developing. u-Campus is the new type campus which applies to ubiquitous computer technology and wireless network one. at this thesis, it is designed u-campus construction using zigbee technology with u-campus basic technology. u-Campus service, being subject to zigbee wireless communication skills, presents the members an convenient service using zigbee network.

• Journal of Advanced Navigation Technology
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• v.21 no.3
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• pp.306-311
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• 2017

In the future ubiquitous network, information will collect data from various sensors in the field. Since the sensor nodes are equipped with small, often irreplaceable, batteries with limited power capacity, it is essential that the network be energy-efficient in order to maximize its lifetime. In this paper, we propose an effective network routing method that can operate with low power as well as the transmission of data and information obtained from sensor networks, and identified the number of sensors with the best connectivity to help with the proper placement of the sensor. These purposes of this research are the development of the sensor middle-ware to integrate the maritime information and the proposal of the routing algorithm for gathering the maritime information of various sensors. In addition, for more secure ship navigation, we proposed a method to construct a sensor network using various electronic equipments that are difficult to access in a ship, and then construct a communication system using NMEA(the national marine electronics association), a ship communication standard, in the future.

• Journal of Engineering Education Research
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• v.13 no.2
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• pp.7-11
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• 2010

As the development of the computer and communication technologies, the ubiquitous society can be realized to the world early in the future. Thus, the localization system in Wireless Personal Area Network (WPAN) is required for many users of ubiquitous society to provide the ubiquitous computing based applications in respective of anytime and anywhere. In this paper, we propose the distance measurement scheme that is based on the distance measurement using RSSI (Received Signal Strength Indicator) of sensor module considering of two distance conditions for the localization system using Zigbee in WPAN. Also, the localization errors of the proposed scheme are analyzed in the three scenarios that the mobile module tracks in the in $6m{\times}6m$ scaled experimentation area. In addition to this, the monitoring subsystem is developed using GUI (Graphical User Interface) in order to monitor the location of the moving objects accurately and user-friendly.