• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.4
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• pp.587-594
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• 2022

This paper analyzed radio link throughput performance by applying radio link simulation and test equipment because there is limit in train filed test in 420 km/h high speed environment. According to the radio performance analysis, the throughput performance is slightly degraded in QPSK and 16QAM modulation schemes. But throughput performance is highly degraded in 64QAM modulation scheme.

• Proceedings of the Korean Society of Computer Information Conference
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• 2011.06a
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• pp.273-276
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• 2011

우리는 감성 공학에 기반하여 일상 생활 속에서 비침습적이면서 사용하기 간편한 광전용적맥파신호를 계측하고 분석하는 이어폰형 생체 신호 측정 시스템에 관하여 연구하였다. 생체 신호 측정 시스템에서는 광전용적맥파(photoplethysmograph, PPG)와 3축 가속도로 생체 신호와 운동 신호를 활용하였다. 수신된 생체 신호인 광전용적맥파 신호는 Peak 검출 및 전처리 알고리즘을 통하여 심박동변동성(heart rate Variablity,HRV)에 대한 시계열 정보로 변환하고 고속 퓨리에 변환(Fast Fourier Transfirm, FFT)과 전력 스펙트럼 밀도 분석(Power Spectrum Density, PSD)방법으로 교감과 부교감 신경 활성도 변화를 관측하였고, 운동 센서로 움직임을 관측하였다. 수신부 시스템은 안드로이드 기반의 자바 어플리케이션으로 스마트 폰에서 구현하였고, 송신부인 이어폰 생체정보 측정모듈로 맥파를 측정하여 상황에 따라 변화하는 자율 신경계의 활성도비율을 확인하였다.

• Journal of the Korean Society of Radiology
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• v.2 no.1
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• pp.5-10
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• 2008

This study developed a PDA based wireless communication radiation measuring instrument using Bluetooth. The proposed system is composed of Student Radiation Monitor of Vernier using GM (Geiger Mueller) counter tube as a radiation measuring sensor, LabPro of Vernier as a module for data collection, Promi SD 101 of Initium, which can make Bluetooth communication up to 30 m, for wireless data transmission, and HP 5550 embedded with Pocket PC 2003 as OS for data storage and display. Because GM counter tube is used as a radiation measuring sensor, the system cannot measure radiation energy but measures count volume and count rate. When the result of natural radiation measuring by the PDA based system was compared with that by a PC based system, it was found that the proposed system transmits and receives data without distortion.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.9
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• pp.1793-1798
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• 2007

Recently there are some trends to construct smart home system infrastructure depending upon the development of Information and Communication Technology. Also requirements of the Ubiquitous Healthcare Systems at home which can monitor the status of health continuously are increased rapidly comparing with hospitals. Healthcare service can be divided into two categories. The first one is Alarm Service that can be used for the emergency status and the other one is Remote Support Service which can monitor the patient including home environments and give those diagnosis information to medical office or to his family. Generally wired networks and fixed healthcare measuring system have some limits to transmit reliable realtime based information for both categories described above comparing with portable monitoring system. Getting over the inefficiency we will design and implement portable healthcare system under the wireless Zigbee network environments.

• Proceedings of the Korean Society of Computer Information Conference
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• 2014.07a
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• pp.417-418
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• 2014

본 논문에서는 무선 바이오센서 기반에서 동물 생체측정 정보를 이용한 질병 예방 감시 시스템을 설계하였다. 제안 시스템은 바이오센서를 이용하여 동물의 심박, 호흡수, 운동량을 측정할 수 있는 모듈을 개발하고 생체 신호를 계측하여 신호 처리된 정보를 Zigbee 무선 통신모듈을 이용하여 원격 데이터베이스에 전송하도록 설계하였다. 모니터링 시스템에서는 수집된 생체 정보의 연속적인 변화를 통하여 가축의 이상여부를 판단하고 질병 발생여부를 조기에 발견할 수 있게 가축의 상태정보를 제공한다. 본 연구결과는 향후 축산 농가의 질병 감시를 통하여 질병의 확산을 차단할 수 있는 긴급대처시스템을 구축하는데 활용 될 것이다.

• Journal of the Korea institute for structural maintenance and inspection
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• v.16 no.1
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• pp.120-130
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• 2012

As long span and complex bridges are constructed often recently, safety estimation became a big issue. Various types of measuring instruments are installed in case of long span bridge. New wireless technologies for long span bridges such as sending information through a gateway at the field or sending it through cables by signal processing the sensing data are applied these days. However, The case of occurred accidents related to bridge in the world have been reported that serious accidents occur due to lack of real-time proactive, intelligent action based on recognition accidents. To solve this problem in this study, the idea of "communication among things", which is the basic method of RFID/USN technology, is applied to the bridge monitoring system. A sensor node module for USN based intelligent bridge system in which sensor are utilized on the bridge and communicates interactively to prevent accidents when it captures the alert signals and urgent events, sends RF wireless signal to the nearest traffic signal to block the traffic and prevent massive accidents, is designed and tested by performing TinyOS based middleware design and sensor test free Space trans-receiving distance.

• Proceedings of the Korean Society of Computer Information Conference
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• 2016.07a
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• pp.283-284
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• 2016

본 논문에서는 다중 생체계측 장비를 CMCIS(Central Monitoring and Cardiology Information System) 기반의 통합 시스템에 연동하기 위한 내장형 MDEC 모듈을 소개하고 바이탈 사인 장비와 결합하여 무선 네트워킹을 통하여 원격지에 생체정보를 전송하는 시스템을 제안한다. 내장형 MDEC 모듈로 전송된 데이터는 실시간 뷰에 표시됨으로서 환자정보를 원격지에서 감시 및 관리할 수 있는 유효성을 가지게 된다. 본 연구의 결과는 CMCIS 기반의 통합 시스템을 구축하는 기반기술로 향후 효율적 의료서비스에 기여할 것으로 사료된다.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.26 no.4
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• pp.271-274
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• 2013

Inclinometer sensors are widely applied in many fields. Especially in the field of construction of high-rise buildings also measure the horizontal and vertical help has been applied to monitor. Recent micro electro-mechanical system(MEMS) technology with the development of the many sensors have been developed. In this paper, a MEMS inclinometer is based on a MEMS accelerometer. The sensor can measure the angle of inclination using the relationship between static acceleration and gravity acceleration from an accelerometer. From this principle, inclinometer has been developed that has more accurate. The accuracy is proved by the experiment with laser displacement. Results in the experiment express high-accuracy, stability and economics of MEMS inclinometer. In conclusion, wireless MEMS inclinometer sensor is expected to be applicable in the areas of construction and many other industries with accurate and convenient monitoring system.

• Proceedings of the Korea Institute of Convergence Signal Processing
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• 2006.06a
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• pp.113-116
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• 2006

최근 무선센서네트워크 기술을 이용한 다양한 시도가 이루어지고 있으며 특히 헬스케어분에서 활발히 연구되어지고 있다. 본 연구에서는 무선센서노드를 이용하여 계측된 생체신호를 바탕으로 환자의 상태 및 진단을 위한 기초자료를 활용하기 위한 시스템을 구현하였다. 생체신호로 ECG(electrocardiogram)와 체온 파라미터를 사용하였으며 ECG신호의 QRS특성점을 축출하기 위해 Pan&Tomkins에 개발된 알고리즘을 사용하였다. 또한 효율적인 모니터링을 위해 비정상적인 ECG신호에 대한 알림기능을 구현하였으며 이러한 감시기능은 상시 모니터링을 하지 않고도 환자의 상태를 알 수 있게 하였다. 본 연구에서 구현된 이러한 시스템기술은 국내의 고령화 문제로 발생되는 의료비용을 크게 감소시킬 수 있을 것으로 예상된다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.5
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• pp.1-9
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• 2016

Railroad bridges account for 25% of the entire high-speed rail network. Railway bridges are subject to gradual structural degradation or fatigue accumulation due to consistent and repeating excitation by fast moving trains. Wireless sensing technology has opened up a new avenue for bridge health monitoring owing to its low-cost, high fidelity, and multiple sensing capability. On the other hand, measuring the transient response during train passage is quite challenging that the current wireless sensor system cannot be applied due to the intrinsic time delay of the sensor network. Therefore, this paper presents a framework for monitoring such transient responses with wireless sensing systems using 1) real-time excessive vibration monitoring through ultra-low-power MEMS accelerometers, and 2) post-event time synchronization scheme. The ultra-low power accelerometer continuously monitors the vibration and trigger network when excessive vibrations are detected. The entire network of wireless smart sensors starts sensing through triggering and the post-event time synchronization is conducted to compensate for the time error on the measured responses. The results of this study highlight the potential of detecting the impact load and triggering the entire network, as well as the effectiveness of the post-event time synchronized scheme for compensating for the time error. A numerical and experimental study was carried out to validate the proposed sensing hardware and time synchronization method.