• 한국HCI학회:학술대회논문집
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• 2008.02a
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• pp.141-146
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• 2008

As the interest about ubiquitous environment is increasing, there are many researches about the services in this environment. These services have important issues in interpreting the users' context, using many kinds of sensors, like PDA, GPS and accelerometers. Low level raw data, which sensors like accelerometers calibrates, are hard to use, and to provide real-time services preprocessing and interpreting the data into context, in real-time, is important. This paper describes a context integrate system which can integrate these sensors and also sensors which has raw data, like accelerometers and physiological sensors, and define the context interpret rule with XML. The proposing system reduces programming operations when adding a sensor to the sensor network or modifying the context interpreting rule by using XML. By using this system, we implemented a real-time data monitoring system which can describe the numeric data into graphs, and assist the user to validate the data and results of the preprocess phase, and also support the external services and applications to use the context of the user.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.06a
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• pp.375-378
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• 2007

This paper describes indoor location estimation intelligent robot. It is loaded indoor location estimation function using RSSI based indoor location estimation system and wireless sensor networks. Spartan III(Xilinx, U.S.A.) is used as a main control device in the mobile robot and the current direction data is collected in the indoor location estimation system. The data is transferred to the wireless sensor network node attached to the mobile robot through Zigbee/IEEE 802.15.4, a wireless communication. After receiving it, with the data of magnetic compass the node is aware of and senses the direction the robot head for and the robot moves to its destination. Indoor location estimation intelligent robot is can be moved efficiently and actively without obstacle on flat ground to the appointment position by user.

• The KIPS Transactions:PartA
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• v.17A no.3
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• pp.127-136
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• 2010

A wireless sensor network(WSN) which roles as a mediator between living environment and computers in ubiquitous computing is very essential research area. Due to the constraint that sensor nodes should work in very resource-restricted circumstances, an operating system that can manage resources effectively is demanded. Also, a sensor network should be able to deal with many events quickly and simultaneously in order to respond to various physical changes in outer environment. The Sensor Network Operating System such as TinyOS, MANTIS and NanoQplus is much designed so that it can satisfy such requirement. But, for programmers who develop application program for sensor networks, they have lack of frameworks which the development is easily possible from restricted development environment. In this paper for this, we implemented a state machine framework apt for responsive systems in NanoQplus which is multi-thread-based sensor network operating system. In addition we propose an event broker module(EBM) for effective event dispatching, a message data structure for message sharing among state machines, and an execution module that handles messages and their queue and performs state transition of the machines. Furthermore, we could do the development more easily an application program with a state-based framework by developing CASE tools.

• The KIPS Transactions:PartC
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• v.14C no.4
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• pp.371-382
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• 2007

In this paper, we propose a real-time sensor node platform that efficiently manages periodic and aperiodic tasks. Since existing sensor node platforms available in literature focus on minimizing the usage of memory and power consumptions, they are not capable of supporting the management of tasks that need their real-time execution and fast average response time. We first analyze how to structure periodic or aperiodic task decomposition in the TinyOS-based sensor node platform as regard to guaranteeing the deadlines of ail the periodic tasks and aiming to providing aperiodic tasks with average good response time. Then we present the application and efficiency of the proposed real-time sensor node platform in the sensor node equipped with a low-power 8-bit microcontroller, an IEEE802.15.4 compliant 2.4GHz RF transceiver, and several sensors. Extensive experiments show that our sensor node platform yields efficient performance in terms of three significant, objective goals: deadline miss ratio of periodic tasks, average response time of aperiodic tasks, and processor utilization of periodic and aperiodic tasks.

• Management & Information Systems Review
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• v.34 no.3
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• pp.141-160
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• 2015

IoT(Internet of Things) has become a major issue as new type of convergence technology, expending existing of USNs(Ubiquitous Sensor Networks), NFC(Near Field Communication), and M2M(Machine to Machine). The IoT technology defines as a networking for things, which can establish intelligent links collaboratively for sensing networking and processing between each other without human intervention. The purpose of this study is to investigate to forecast the future distribution changes and orientation of contribution of distribution industry on IoT and to provide the implication of distribution changes. To become a global market leader, IoT requires much more development of core technology of IoT for distribution industry, new service creation and try to use a market-based demand side strategy to create markets. So, to become a global leader in distribution industry, this study results show that first of all establishment of standardization of IoT, privacy safeguards, security issues, stability and value were more important than others. The research findings suggest that the development goals of IoT should strive to boost the creation of a global leader in distribution industry and convenience to consider consumers' demands as the most important thing.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.4
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• pp.1294-1300
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• 2010

In an environment where all nodes move, the sensor node receives anchor node's position information within communication radius and modifies the received anchor node's position information by one's traveled distance and direction in saving in one's memory, where if there at least 3, one's position is determined by performing localization through trilateration. The proposed localization mechanisms have been simulated in the Matlab. In an environment where certain distance is maintained and nodes move towards the same direction, the probability for the sensor node to meet at least 3 anchor nodes with absolute coordinates within 1 hub range is remote. Even if the sensor node has estimated its position with at least 3 beacon information, the angle ${\theta}$ error of accelerator and digital compass will continuously apply by the passage of time in enlarging the error tolerance and its estimated position not being relied. Dead reckoning technology is used as a supplementary position tracking navigation technology in places where GPS doesn't operate, where one's position can be estimated by knowing the distance and direction the node has traveled with acceleration sensor and digital compass. The localization algorithm to be explained is a localization technique that uses Dead reckoning where all nodes are loaded with omnidirectional antenna, and assumes that one's traveling distance and direction can be known with accelerator and digital compass. The simulation results show that our scheme performed better than other mechanisms (e.g. MCL, DV-distance).

• Fire Science and Engineering
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• v.22 no.3
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• pp.278-286
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• 2008

When big fire in high rise building and multiplex happens, the needs for high prevention system of disaster are being increased for getting the real-time scene state, quick lifesaver, and safe life security. In this paper the proposed evacuation guidance algorithm which analyzed the feature and danger of fire in high rise buildings, gave simplicity and scalability. Our research shows as fire and disaster occur in high rise buildings we construct sensor networks and sense realtime location information on fire alive people, and the situation information for fire instructed quick and safe escaping route by using mesh routing algorithm scheme relative to exit sign.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.5
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• pp.486-494
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• 2014

Intelligent homes consist of ubiquitous sensors, home networks, and a context-aware computing system. These homes are expected to offer many services such as intelligent air-conditioning, lighting control, health monitoring, and home security. In order to realize these services, many researchers have worked on various research topics including smart sensors with low power consumption, home network protocols, resident and location detection, context-awareness, and scenario and service control. This paper presents the real-time metabolic rate estimation method that is based on measured heart rate for human adaptive appliance (air-conditioner, lighting etc.). This estimation results can provide valuable information to control smart appliances so that they can adjust themselves according to the status of residents. The heart rate based method has been experimentally compared with the location-based method on a test bed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38B no.11
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• pp.895-901
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• 2013

In this paper we propose design of a multi-protocol gateway middleware based on USN. The proposed multi-protocol gateway middleware defined the transmit messages format, and were used the USN module interface protocol for connect to external application MCU using the UART. In this case, the gateway was checks the communication state of Zigbee module with settings information, and setting Zigbee serial PDU format. The experimental results of the proposed multi-protocol gateway middleware were proved the efficiency of integrate protocol gateway to use the multi-protocol gateway than gateway to using the repeater through the power control and communications a controlled experiment.

• Proceedings of the Korea Contents Association Conference
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• 2006.05a
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• pp.479-482
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• 2006

Mobile Telemedicine uses common technologies that provide a conduit for information exchange between physicians nurses and patients. In addition to patient records, medical professionals will obtain vital signs and other reference data through Ubiquitous Sensor networks(USN). In this paper about a design and implementation of RFID reader platform that received RFID tag information from patients tags, transmit the data to SBC(Single board computer) based on Intel PXA255 ARM CPU and SBC transmit the data to MySQL server in hospital using by Wireless Internet. his system that based on Embedded Linux is composed of RFID module, ARM processor, RS-232 interface, and Wireless LAN. This paper also provides a brief overview and concept of RFID reader, and proposes the design and implementations of the RFID reader platform used QT and MySQL based on Embedded Linux.