• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.7
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• pp.2549-2558
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• 2010

A Remote Vital Sign Monitor is an in-home healthcare system designed to wirelessly monitor core-body temperature. The Remote Vital Sign Monitor provides accuracy and features which are comparable to hospital equipment while minimizing cost with ease-of-use. It has two parts, a bandage and a monitor. The bandage and the monitor both use the Chipcon2430(CC2430) which contains an integrated 2.4GHz Direct Sequence Spread Spectrum radio. The CC2430 allows Remote Vital Sign Monitor to operate at over a 100-foot indoor radius. A simple user interface allows the user to set an upper temperature and a lower temperature that is monitored with respect to the core-body temperature. If the core-body temperature exceeds the one of two defined temperatures, the alarm will sound. The alarm is powered by a low-voltage audio amplifier circuit which is connected to a speaker. In order to accurately calculate the core-body temperature, the Remote Vital Sign Monitor must utilize an accurate temperature sensing device. The thermistor selected from GE Sensing satisfies the need for a sensitive and accurate temperature reading. The LCD monitor has a screen size that measures 64.5mm long by 16.4mm wide and also contains back light, and this should allow the user to clearly view the monitor from at least 3 feet away in both light and dark situations.

• 한국정보통신설비학회:학술대회논문집
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• 2009.08a
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• pp.162-164
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• 2009

IEEE 802.15.4에서 채널 간 충돌을 회피하기 위해 제안된 CSMA/CA 알고리듬은 수신되는 신호의 상관관계를 나타내는 지표인 LQI (Link Quality Indicator) 값과 수신되는 신호의 크기를 나타내는 지표인 RSSI (Received Signal Strength Indicator) 값을 이용한다. 지그비 모듈에서 측정되는 LQI 값은 수신되는 신호의 크기에 따라 변화하는데, 그 상관관계가 매우 부정확한 문제가 있어 왔다. 본 논문에서는 CC2430과 CC2591을 이용해 제작된 지그비 모듈을 기반으로 수신 신호의 크기와 LQI 값을 실험적으로 측정하여 RSSI 값에 따른 LQI 값의 상관관계를 분석하였다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.11
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• pp.1214-1219
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• 2010

In this paper, a software radio system, supporting the physical layer of IEEE 802.15.4 standard, has been developed using USRP(Universal Software Radio Peripheral) board and GNU Radio package of an open source development kit for software radio. The software radio system supports the standards of BPSK and OQPSK modulations for 868/915 MHz band and OQPSK modulation for 2.45 GHz band. To verify the operation of the developed system, it has been tested under the standard signals according to the frequency band and packet structures for the transmitting and receiving operation. At 2.4 GHz, the Smart RF EV board and CC2430 modules are used to check the proper operation of the software radio system. The system performance test shows that the emission power spectrum, the eye-pattern, and PER(Packet Error Rate) meet the standard. It has been confirmed that the developed system supports the PHY layer of IEEE 802.15.4.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.1B
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• pp.162-175
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• 2010

Currently, geographical information is interpreted and adopted in a wide range of context, and used for meeting diverse demands, such as, battlefield, traffic management, or public safety. With such an explosive increase of location-based applications, a considerable amount of research on the localization technique has been carried out. Among them, RSS (Received Signal Strength)-based approach is used especially for the indoor localization due to intrinsic limitations of the indoor environment. In this paper, we perform theoretical and empirical studies on enhancing the accuracy of the RSS-based localization on the IEEE 802.15.4 network. To this end, we set up an indoor testbed and implement a localization system on it. In addition to the theoretical analysis of the localization algorithm that we used, an empirical analysis on the effect of the factors which affect the accuracy of a localization system is carried out. Finally, we suggest some critical guidelines that should be considered for building a highly accurate localization system.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.05a
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• pp.487-490
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• 2008

This paper develop a nurse call system using the wireless communication to resolve that a portable problem of established nurse call system. The established nurse call system has a problem that don't use outside of the sickroom because using a wire communication. The proposed nurse call system is composed of a terminal for nurse, a terminal for patient and a server part. The efficacy of the proposed system is verified by means of experimental. Experimental results are presented that show the effectiveness.