• Title/Summary/Keyword: Radio Monitoring

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Dynamic Tree Formation Protocol in UAV Formation Flying Network for Disaster Monitoring (재난 모니터링을 위한 편대비행 UAV 네트워크에서 동적 트리 형성 프로토콜)

  • Park, Jin-Hee;Kim, Yeon-Joo;Chung, Jin-Wook
    • Journal of Advanced Navigation Technology
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    • v.16 no.2
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    • pp.271-277
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    • 2012
  • In this paper, we propose a dynamic tree formation protocol for multiple UAV which is gathering data or accomplishing a mission such as disaster monitoring, environment monitoring, and disaster relief. Especilly, we designed Hop-LQI Weight algorithm to form optimal tree in wireless dynamic environment applying situation of radio signal attenuation over distance and implemented our algorithm in MSP 430 K-mote sensor platform using TinyOS codes. We verified performance of our algorithm by comparing average link setup time by the number of nodes with minimum LQI, link cost calculation method in wireless communication.

Monitoring Ion Energy Distribution in Capacitively Coupled Plasmas Using Non-invasive Radio-Frequency Voltage Measurements

  • Choi, Myung-Sun;Lee, Seok-Hwan;Jang, Yunchang;Ryu, Sangwon;Kim, Gon-Ho
    • Applied Science and Convergence Technology
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    • v.23 no.6
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    • pp.357-365
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    • 2014
  • A non-invasive method for ion energy distribution measurement at a RF biased surface is proposed for monitoring the property of ion bombardments in capacitively coupled plasma sources. To obtain the ion energy distribution, the measured electrode voltage is analyzed based on the circuit model which is developed with the linearized sheath capacitance on the assumption that the RF driven sheath behaves like a simple diode for a bias power whose frequency is much lower than the ion plasma frequency. The method is verified by comparing the ion energy distribution function obtained from the proposed model with the experimental result taken from the ion energy analyzer in a dual cathode capacitively coupled plasma source driven by a 100 MHz source power and a 400 kHz bias power.

Development and characterization of a ultra-wide bandwidth video detector for the UHF partial discharge monitoring system (UHF 부분방전 감시 장치를 위한 초광대역 검출장치 개발 및 특성조사)

  • Park, Ki-Jun;Goo, Sun-Geun;Yoon, Jin-Yul
    • Proceedings of the KIEE Conference
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    • 2002.07c
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    • pp.1649-1651
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    • 2002
  • Ultra-wide bandwidth (UWB) detection method has been widely used as a front end detection scheme for the ultra-high frequency (UHF) partial discharge (PD) monitoring systems. A broad-band video detector module was developed and characterized for the UHF UWB PD detection systems. The useable bandwidth of the module is more than 2 GHz and it is optimized for 50-ohm systems. The detection sensitivity and dynamic range of the module were characterized by using a known ns-width RF pulses of GHz range. The dynamic range is more than 6-decades and the module can detect pulsed RF signals down to 1 nW. The detector module can eliminate expensive equipment such as high speed oscilloscopes and radio frequency (RF) spectrum analyzers. Therefore, it enables one to use slow speed data acquisition systems for the PD monitoring at the UHF range. The detector module was used to detect real PDs of about <3 pC. The module converts the UWB PD signals into a low-bandwidth video signal with a high signal-to-noise ratio.

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Software GNSS Receiver for Signal Experiments

  • Kovar, Pavel;Seidl, Libor;Spacek, Josef;Vejrazka, Frantisek
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • v.2
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    • pp.391-394
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    • 2006
  • The paper deals with the experimental GNSS receiver built at the Czech Technical University for experiments with the real GNSS signal. The receiver is based on software defined radio architecture. Receiver consists of the RF front end and a digital processor based on programmable logic. Receiver RF front end supports GPS L1, L2, L5, WAAS/EGNOS, GALILEO L1, E5A, E5B signals as well as GLONASS L1 and L2 signals. The digital processor is based on Field Programmable Gate Array (FPGA) which supports embedded processor. The receiver is used for various experiments with the GNSS signals like GPS L1/EGNOS receiver, GLONASS receiver and investigation of the EGNOS signal availability for a land mobile user. On the base of experimental GNSS receiver the GPS L1, L2, EGNOS receiver for railway application was designed. The experimental receiver is also used in GNSS monitoring station, which is independent monitoring facility providing also raw monitoring data of the GPS, EGNOS and Galileo systems via internet.

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Real-time Water Monitoring System for Small Water Supply Facility using High Reliable Wireless Sensor Network (고신뢰 무선센서네트워크를 이용한 실시간 수질 모니터링 시스템)

  • Kang, Hoyong;Jang, Youn-Seon
    • Journal of Sensor Science and Technology
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    • v.24 no.5
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    • pp.331-341
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    • 2015
  • In this paper, real-time water quality monitoring system of small water supply facilities based on IEEE 802.15.4e-2012 DSME MAC and IEEE 802.15.4g-2012 PHY standard is presented, which is capable to acquire for highly reliable water quality information in the wide outdoor areas for effective water quality management of small water quality facilities is distributed in the long distance and remote areas. Previously, Long distance transmission is difficult in most water quality sensor module is using RS-485 protocol. But with this system, even in harsh outdoor environment, it is possible to establish a radio wave sensor in a wide area network, and not only water quality sensor shall be connected to the wireless system, but also wireless integrated management system shall provide more effective way of management of the numerous small water supply facilities spread throughout the community, so that the administrator can remotely monitor the data of water turbidity, pH, residual chlorine in the water-supply, water-level, and generate alarm to cope with risks. The management of small water facilities is done by residents will be very effective to notice water quality information of small water facilities to residents.

Wireless links for global positioning system receivers

  • Casciati, Fabio;Wu, Lijun
    • Smart Structures and Systems
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    • v.10 no.1
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    • pp.1-14
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    • 2012
  • Given an object, its positioning in the space is a main concern in structural monitoring and a required feedback in structural health monitoring, structural control and robotics. In addition, to make the sensor unit wireless is a crucial issue for advanced applications. This paper deals with the exploitation of wireless transmission technology to long-term monitoring GPS (Global Positioning System) receivers - like the Leica GMX 902 and the Leica GRX 1200-pro. These GPS receivers consist of five parts: antenna, receiver, user client computer, interface and power supply. The antenna is mounted on the object to be monitored and is connected with the receiver by a coaxial-cable through which the radio frequency signals are transmitted. The receiver unit acquires, tracks and demodulates the satellite signals and provides, through an interface which in this paper is made wireless, the resulting GPS raw data to the user client computer for being further processed by a suitable positioning algorithm. The power supply reaches the computer by a wired link, while the other modules rely on batteries re-charged by power harvesting devices. Two wireless transmission systems, the 24XStream and the CC1110, are applied to replace the cable transmission between the receiver and the user client computer which up to now was the only market offer. To verify the performance and the reliability of this wireless transmission system, some experiments are conducted. The results show a successful cable replacement.

Implementation of an Environmental Monitoring System based on LoRa for Smart Field Irrigation (노지 관수를 위한 로라 기반 환경 모니터링 시스템 구현)

  • Kim, Byungsoon
    • Journal of Internet Computing and Services
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    • v.20 no.1
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    • pp.11-16
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    • 2019
  • Wireless sensor network is important for precision farming to monitor the growth environment of crops in open field, but radio signals are susceptible to different types of interference such as weather and physical objects. This paper designs and implements an environmental monitoring and weather forecast acquisition systems for smart field irrigation based on LoRa(Long Range) and then applies it to a test bed. And we evaluate the network reliability in terms of packet transmission success rate by comparing its condition on two criteria; the existence of obstacle or rain. The results show that much rain falls can affect on packet loss in LoRa field networks with obstacles.

Time Monitoring of SiO and $H_2O$ Masers Toward Orion KL: The Third Flaring of $H_2O$ Maser Emission

  • Cho, Se-Hyung;Kim, Jaeheon;Yun, Youngjoo;Yoon, Dong-Hwan;Byun, Do-Young
    • The Bulletin of The Korean Astronomical Society
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    • v.38 no.2
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    • pp.63.1-63.1
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    • 2013
  • We present the results of time monitoring observations of $^{28}SiO$ v = 1, 2, J = 1-0, $^{29}SiO$ v = 0, J = 1-0 and $H_2O$ $6_{16}-5_{23}$ maser lines toward radio Source I in Orion KL. The observations have been performed from 2009 June to 2013 April using the 21m single dish radio telescopes of the Korean VLBI Network. Both SiO and $H_2O$ maser lines were simultaneously obtained at 20 epochs. In particular, the third outburst of $H_2O$ maser emission (the first: 1985, the second: 1998) was detected and the flux density variation curve was obtained. The maximum flux density flared up to an order of $10^5$ Jy during 2012 May-July at peak velocity of 7.33 km $s^{-1}$. Hirota et al. (2011) reported that the bursting maser features are located at 8" from Source I and coincident with the interacting region between the outflow from Source I and a dense ambient gas, Orion Compact Ridge. In the case of SiO masers arising from close to the Source I, the peak emission of the v = 1, J = 1-0 maser line appeared in 2010 April. We are investigating the possible relation between this SiO maser peak emission and the third $H_2O$ maser flaring.

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A Study on the Performance Monitoring and Optimization of a High Speed Network for the Transfer of Massive VLBI Data (대용량 VLBI 데이터 전송을 위한 초고속 네트워크 성능 모니터링 및 최적화 연구)

  • Song, Min-Gyu;Kim, Hyo-Ryung;Kang, Yong-Woo
    • The Journal of the Korea institute of electronic communication sciences
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    • v.14 no.6
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    • pp.1097-1108
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    • 2019
  • In VLBI(Very Long Baseline Interferometry), the observed data created in many observatories which are far away from each other should be collected in correlation center for data analysis. Traditionally, observed data is moved by transportation such as car or airplane. But it is replaced with data transfer over the network rapidly as the advancement of information technology, and therefore, international cooperative research is also now more widely expanding. e-KVN(electronic Korean VLBI Network) has been upgraded two times so the network interface of KVN has been evolved to the highest specification of 100GbE. During this time period, the portion of network usage for VLBI observations and experiments in KVN has been increased exponentially. In this paper, we describe KVN VLBI system and network technology for the performance upgrade and advanced status monitoring between three radio astronomy observatories and Daejeon correlation center with KREONET(Korea Research Environment Open NETwork). Furthermore, future plan of e-KVN for the implementation of wide band VLBI observation will be also briefly discussed.

A New Moving Mobile Base Station (MMBS) Scheme for Low Power RMIMS Wireless System(PartII:Multiple MMBS service schemes for RMIS QoS guarantee) (저전력 RMIMS 무선 터미널을 위한 새로운 움직이는 이동 기지국 시스템 구조(2부:QoS 보장을 위한 다중 MMBS 서비스 구조))

  • 박수열;고윤호;유상조;김성대
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.24 no.12B
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    • pp.2320-2334
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    • 1999
  • In this paper, we propose multiple IS-MMBS service schemes for very low power and micro-size RMIMS (radio-interfaced micro information monitoring system) terminals. In MMBS service area, when new arrival RMIMS terminals have real-time traffic characteristic or large traffic bandwidth, only single IS-MMBS service scheme can not guarantee RMIMS terminal's QoS(quality of service) such as buffer overflow or packet loss. In this case, the proposed multiple IS-MMBS service schemes can be effectively used for QoS service of RMIMS terminal. According to clustering method of RMIMS terminals and MMBS segment method, the proposed schemes can be divided into terminal segment method, region segment method, application based segment method, traffic type based segment method, overlapping segment method and hybrid segment method

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