• Proceedings of the Korean Society of Computer Information Conference
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• 2008.06a
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• pp.263-268
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• 2008

고도의 정보 사회로의 빠른 변화는 통신 기술의 발달과 통신 정보들의 다양함에 있다. 현대 사회에서 이용자들은 기존의 통신 서비스보다 좀 더 복잡한 기능과 편리한 기능 다양한 서비스를 필요로 하고 있다. 최근 전 세계적으로 '언제나 어디서나'라는 뜻을 가진 유비쿼터스 사회를 이루기 위한 근거리 무선 통신에 대해 관심을 많이 가지고 있으며 그에 따라 연구와 개발이 활발히 진행이 되고 있다. 무선통신 환경이 증가하고 무선 네트워크화의 필요와 수요에 따른 차세대 근거리 무선 통신 기술 중 대표적인 ZigBee 통신과 기능검증에 대한 H/W 플랫폼을 설계하고 구현하였으며 실험을 통하여 ZigBee의 전송도달거리와 송수신 속도를 확인하였다. 근거리 무선 통신 중 ZigBee의 특성을 고찰하였고 근거리 무선 통신의 연구 방향에 대해 제시하였다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2008.06a
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• pp.269-273
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• 2008

본 논문에서는 근거리 무선 통신을 이용하여 사용자의 현재 위치에서 일어나고 있는 교통사고, 화재, 환자발생 등의 긴급재난상황 목격시 사용자가 해당 상황을 ZigBee 기반의 무선 센서 네트워크 사용자에게 알리고, 알린 정보를 실시간 쉽게 확인 할 수 있도록 긴급재난상황을 모니터링 하는 시스템을 제안하였다. 근거리 무선 통신 중센서와 사용자 무선 단말기 사이의 데이터 전송 구조가 간단하고, 초저가의 센서 네트워크 구성시 낮은 전력을 소모하는 장점을 가진 ZigBee로 구현하였다. 현재 사용자 주변의 일어나는 긴급재난 상황을 주변 사용자와 ZigBee 기반의 무선 센서 네트워크를 구축하여 실시간으로 보다 정확한 정보를 주변 사용자에게 알려주거나 혹은 사용자가 모니터링을 하여 사용자의 피해를 최소화로 줄여 사용자의 안전과 편의를 향상시킨다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.6
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• pp.1332-1336
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• 2007

This paper aims to design zig joint three dimensionally in order to secure accurate construction of a long bridge and suggests an improved structural consideration applying a simulation techniques to solve occurring problems at zig joint area. This preliminary simulation approach may improve the efficiency of construction engineering and enhance technical competitive since many budgets are involved in the manufacturing of zig.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.4
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• pp.41-48
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• 2010

In this paper, a new type of integrated AFCI is designed and implemented by combining individual circuit breaker characteristics, which can effectively detect arc fault signals in real-time. The proposed integrated AFCI satisfies the UL1699, the USA certification standard, and the Korean circuit breaker standards such as KS C4613 and KS C8321. Data signals are transferred to the management server via ZigBee network to analyze dangerous factors and to prevent unwanted trip. It is also shown by experiments that arc fault signals are detected and analyzed by using the integrated AFCI with ZigBee networks.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.1003-1006
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• 2009

Recently, Ubiquitous computing technology is increasing necessity for object recognition and a location tracking technology to meet various applications. The location tracking technology is the fundamental to the Context-Aware of users in Ubiquitous environment and its efficiency has to be improved using IEEE 802.15.4 ZigBee used in current infra such as ubiquitous sensor network. But because the IEEE 802.15.4 ZigBee protocol has limitation to apply location tracking technology such as ToA and TDoA, Zone-based Location Tracking technology using RSSI is needed. In this paper suggests RSSI-based 802.15.4 ZigBee local positioning protocol to support a positioning tracking service in Ubiqutous environment. And Zone-based location tracking system is designed for actual the indoor location tracking service.

• IT SoC Magazine
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• s.15
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• pp.39-43
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• 2006

• Journal of Satellite, Information and Communications
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• v.11 no.2
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• pp.8-13
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• 2016

A buoy is a float attached by chain to the seabed to mark channels in a harbor or underwater hazards and can be classified into two major types as autonomous buoys and fixed buoys. When there is high demand such as marking channels in a harbor, monitoring ecology of ocean and environmental monitoring of coastal areas, smart buoys are developed. The smart buoys have wireless network systems such as GPS, CDMA and ZigBee. Using the GPS techniques, location and environments of buoy can be monitored and traced. However, the GPS in fixed buoy systems has a high power consumption and cost. Using many buoys on low power ZigBee basis allows dramatic reduction of the overall power consumption. In this study, it is aimed at the design of the trackable protocol for a buoy system which has low data rate and low power consumption. The proposed protocol has advantages that it can detect abnormal movement and gather trackable information without any system changes. In the introduced protocol, additional 2 bits and join request messages are used for trackable buoy system. The behaviors of improved protocol is modeled into petri-net and proved a reachability.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.2
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• pp.156-160
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• 2012

Recently, the demands of the large scale machine tools gradually increase to machine the large parts, such as large scale crankshaft, yaw and pitch bearings for the wind power generator and the vehicle or aircraft components. But the high technology is necessary in order to develop the huge machine tools. Furthermore, the global market of it has been monopolized by a few companies. So, we need to develop the large scale machine tools and study its core technology to rush into the increasing market. In this study, we carried out the researches for the important core technology of a multi-tasking, machine tool; a large scale 5-axis machine tool of gantry type for multi-task machining. This study is focused on the design of large size gantry type multi-axis machine. In the case of large size of machine the cross rail deflection in the X-axis is significant. To reduce the deflection due to the eccentric spindle head, a special hollow type design in the cross rail with outside ram is adapted in this study. Also, the Zig-Zag motion in the Y-axis is inevitable with the gantry geometry, which is by the un-balancing, different motion at the left and the right columns moving. We tried to reduce the influence of Zig-Zag motion using FEM with different loading conditions at the left and the right side column.

• Proceedings of the KIEE Conference
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• 2005.10b
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• pp.312-314
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• 2005

We have implement indoor positioning system to supply orientation information, We have used ultrasound in indoor positioning system for distance and orientation measurements, then propose a set of methods to calculate orientation from an array of well placed ultrasonic sensors operating in the indoor positioning system, We have design and implement a indoor positioning system using a combination of hardware and software and demonstrate end-to-end functionality of the system, We have implement ZigBee based home automation system using location-aware System.

• Journal of Information Technology Services
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• v.10 no.4
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• pp.243-258
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• 2011

With increasing interest in ubiquitous computing technology, an infrastructure for the short-distance wireless communication has been extended socially, bringing spotlight to the security system using the image or location. In case of existing security system, there have been issues such as the occurrences of blind spots, difficulty in recognizing multiple objects and storing of the unspecified objects. In order to solve this issue, zone-based location-estimation search system for the image have been suggested as an alternative based on the real-time location determination technology combined with image. This paper intends to suggest the search service for the image zone-based location-estimation. For this, it proposed the location determination algorism using IEEE 802.15.4/ZigBee's RSSI and for real-time image service, the RTP/RTCP protocol was applied. In order to combine the location and image, at the event of the entry of the specified target, the record of the time for image and the time of occurrence of the event on a global time standard, it has devised a time stamp, applying XML based meta data formation method based on the media's feature data based in connection with the location based data for the events of the object. Using the proposed meta data, the service mode which can search for the image from the point in time when the entry of the specified target was proposed.