• Journal of Advanced Navigation Technology
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• v.14 no.6
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• pp.824-830
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• 2010

PLC_Zigbee system, implemented in a previous study, uses ZigBee Node based on PLC (Power Line Communication). The weak point of the system is that the long distance powerline communication and PLC is impossible to use in the areas where the powerline is not installed. In this paper, we added CDMA (Code Division Multiple Access) module using a data transfer method of SMS (Short Message Service) and XBee of WSN (Wireless Sensor Network) module to the previous system, and got around the restriction of place and environment of PLC system through the interfacing of each communication media. We, thus, implemented a wide range of real monitoring system.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.355-358
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• 2009

Due to growth of electronics and control devices, automation and situational awareness systems have been applied by automobile. Vision systems with the introduction of unmanned system being actively developed, but are still high price and visual information is passed through the cable, because of cars are difficult to install. In this paper, can be installed inside the car at low-cost, simple image processing device through a wireless communication know the obstacles and the alarm system based on Zigbee wireless communication, infrared and ultrasonic sensors to monitor the situation through with easy parking cars outside the system design was implemented.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.6
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• pp.1301-1306
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• 2015

This paper is to automate the intelligent and equipment to recycle the volatile organic compounds in various a gas stations and a laundry, in real life. In addition, based the ZigBee module and TCP/IP communications on ICT technologies, it's propose an integrated management system to monitor and manage an liquid at a remote location.Furthermore, it's propose a service model that can be freely managed from a remote location based on the app on android. In this paper, we present a communication protocol of the bridge modules and a liquefier of intelligent control system based ZigBee and MCU(Micro Controller Unit). Through the development of smart app based android mobile services in an integrated management system, it's represent for liquefier to a DB server for remote management(MS SQL 2012) and a web server (OS: Windows 2008).

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.9
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• pp.1939-1946
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• 2012

USNs (Ubiquitous Sensor Networks) such as IEEE 802.15.4 ZigBee network share ISM (Industrial, Scientific, and Medical) frequency band with WiFi networks. Once both networks operate in a region, packet collision may happen because of frequency overlapping. To assure this possibility, we conducted experiments where WiFi and ZigBee communication networks had been installed in an area. As a result of the test, successful data transmission rate were reduced due to the frequency overlapping between a WiFi communication channel and a ZigBee communication band. To cope with this problem, we propose a collision avoidance algorithm. In the proposed algorithm, if frequency collision is sensed, new communication channel with different frequency band is allocated to each node. Performance of the proposed frequency collision avoidance algorithm was tested and the results were described.

• Journal of Korea Society of Industrial Information Systems
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• v.14 no.2
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• pp.51-58
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• 2009

In this paper, a system which uses Bluetooth and Zigbee wireless communication and mobile device is designed. The temperature within vehicle and the distance betweeen the vehicle and the obstacle is measured by ultrasonic sensor system. The measured data is sent to the mobile PDA and displayed to assist safe driving.

• Proceedings of the Korea Information Processing Society Conference
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• 2016.04a
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• pp.1002-1003
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• 2016

IoT 기술은 직접적인 사람의 제어 없이 기기 간 자율 통신을 지원하며 빅데이터와 함께 미래 ICT 시장의 큰 비중을 차지할 유망 기술로써 높게 평가되고 있다. 하지만 IoT 기술 범주에 포함되는 Zigbee, Bluetooth, Bluetooth LE, Wi-Fi 등의 기술은 상호 호환되지 않고 통신 목적의 상이하기 때문에, 각 기기들은 다수의 통신 장치를 모두 탑재하고 있으며 이에 따른 운영 효율 또한 높지 않다. 또한, 통신 기술마다 존재하는 독립된 네트워크가 상호 복잡한 서비스 활용에 연계된 환경에서 특정 부분에 장애가 발생할 경우, 서비스별 관계정보 부재로 인하여 장애 발견과 복구 및 대체 서비스 제공이 어렵다. 본고는 이러한 문제를 해결하기 위하여 각 기기간의 이기종 통신I/F 연동방안과 기기 유형별로 발생될 수 있는 환경 변화에 대한 Physicality 분석을 통하여 제공 가능한 대체 서비스 분석방안을 제시한다.

• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.1
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• pp.157-162
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• 2012

Recently, by focusing on the BIS (Bus Information System) which can provide passengers with real -time bus operation information as a method to improve bus transport allotment ratio, the bus information system has been studied for a decade years. Based on such a trend, this paper analyzes the existing bus information system, as the basis of the results obtained, designs an experimental bus information system which is based on a computer, a zigbee communication, several line tracers.

• Proceedings of the Korea Information Processing Society Conference
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• 2010.04a
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• pp.706-709
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• 2010

점차 늘어나고 있는 독거노인들의 건강관리를 정보통신 기술을 통하여 시간과 장소 등에 구애 받지않고, 위급 상황이 감지될 경우 즉각적인 조치를 할 수 있는 u-헬스케어 시스템을 설계하였다. 제안한 시스템은 독거노인의 활동량을 분석하고 움직임을 감지하기 위한 기능을 Zigbee와 PIR 센서로 구현하고, 홈 게이트웨이는 임베디드 리눅스 기반 소형 시스템으로 구현하였다. 구현된 시스템을 통해 피보호자의 일일 활동량 및 주간 활동량 정보를 웹브라우저를 통해서 확인하여 위급 상황 발생 시 보호자의 휴대전화로 이러한 정보를 통보하여 구급할 수 있다.

• Journal of Digital Contents Society
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• v.8 no.3
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• pp.323-328
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• 2007

Communication systems beyond 3G should provide more than 100 Mbps for wireless access. In addition to smart antennas, wireless multi-hop networks are proposed to increase the cell size and throughput. For example, Zigbee technology is expected to provide low cost and low power connectivity and can be implemented in wireless mesh networks larger than is possible with Bluetooth. Also, home embedded system using wireless mesh network is one of the key market areas for Zigbee applications. If the line-of-sight path is shadowed by home obstacles, a direct connection between the access point (AP) and the node is not possible at high frequencies. Therefore, by using multi-hop relay scheme the end node can be reached to AP. In this paper, the relaying of data between the AP and the end node is investigated and the throughput and PER(Packet Error Rate) are evaluated in multi-hop wireless mesh networks by using DSSS/BPSK system.

• The Journal of the Korea Contents Association
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• v.8 no.1
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• pp.143-151
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• 2008

In this paper, we have implemented a ubiquitous healthcare system that can measure and check human's health in anytime and anywhere. The implemented prototype are composed of both front-end and back-end. The front-end have several groups: environment sensor group such as temperature, humidity, photo, voice sensor, health sensor group such as blood pressure, heart beat, electrocardiogram, spo2 sensor, gateway for wired/wireless communication, and RFID reader to identify personal. The back-end has a serial forwarder to propagate measurment results, monitor program, and medical information server The implemented sensor node constructs a sensor network using the Zigbee protocol and is ported the tinyOS. The data gathering base node is linux-based terminal that can transfer a sensed medial data through wireless LAN. And, the medical information server stores the processed medical data and can promptly notify the urgent status to the connected medical team. Through our experiments, we've confirmed the possibility of ubiquitous healthcare system based on sensor network using the Zigbee.