• The Bulletin of The Korean Astronomical Society
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• v.36 no.2
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• pp.60.2-60.2
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• 2011

We introduce the preliminary results of flux monitoring of BL Lac object 0716+714 with the KVN Ulsan 21m radio telescope. This radio source is well known as the intraday variable (IDV) source which is characterized by the rapid flux variation on the time scale of a day or less. In general, the IDV phenomenon is interpreted as the effect of refractive scintillation in the interstellar medium or the evidence of intrinsic flux variation. In previous observations that took a few days, however, it had not been detected the flux variation of short time scale but the monotonic increase and decrease. Therefore, to investigate the longer time scale of 0716+714, we had the flux variation monitoring at 22GHz and 43GHz simultaneously for 9 months from October 2010 to June 2011. We present here the structure functions and the cross correlation functions between different frequencies as well as the light curves.

• Nuclear Engineering and Technology
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• v.49 no.3
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• pp.632-637
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• 2017

Even though the potential for an accident in nuclear power plants is very low, multiple emergency plans are necessary because the impact of such an accident to the public is enormous. One of these emergency plans involves a robotic system for investigating accidents under conditions of high radiation and contaminated air. To develop a robot suitable for operation in a nuclear power plant, we focused on eliminating the three major obstacles that challenge robots in such conditions: the disconnection of radio communication, falling on uneven floors, and loss of localization. To solve the radio problem, a Wi-Fi extender was used in radio shadow areas. To reinforce the walking, we developed two- and four-leg convertible walking, a floor adaptive foot, a roly-poly defensive falling design, and automatic standing recovery after falling methods were developed. To allow the robot to determine its location in the containment building, a bar code landmark reading method was chosen. When a severe accident occurs, this robot will be useful for accident condition monitoring. We also anticipate the robot can serve as a workman aid in a high radiation area during normal operations.

• Journal of Advanced Navigation Technology
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• v.13 no.2
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• pp.252-256
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• 2009

In this paper, the emergency light where is being scattered always inspection and will be able to manage from the management center. Is not interfered in data neck of a bottle actual condition and the data communication will be possible and the cluster monitor network will grow and uses establishes the emergency light monitoring system. Will not be interfered in location of emergency light and not to be will be able to establish the system. And the monitoring network there is by a destroyer and the communication relay system is born breakdown but the dead zone without condition of emergency light proposes the emergency light management system where the monitoring and management are possible.

• The Bulletin of The Korean Astronomical Society
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• v.46 no.2
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• pp.49.2-49.2
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• 2021

We present the results of long-term simultaneous monitoring observations (~ 12 years) of H²O (22 GHz) maser and several vibrationally excited lines of SiO J = 1-0, 2-1, 3-2 masers (43, 86, 129 GHz) carried out with the 21-m antennas of the Korean VLBI Network (KVN) toward a sample of three AGB stars (RT Vir, RR Aql, IRC-10151) that are believed to be semiregular variable star, Mira variable star, and OH/IR star, respectively, according to a sequential evolutionary phase of AGB star. A total 10 transitions were observed, of which we detected H²O, SiO 𝝊 = 1 and 2, J = 1-0, SiO 𝝊 = 1, J = 2-1 and J = 3-2 maser lines in all three target objects, depending on the observational epochs. In this study, we scrutinize the evolutionary traits of each target object based on the maser line profiles, flux/velocity variations, and phase lags with the optical light curves. The IRAS two color diagram and the infrared spectral energy distributions (SEDs) in the wavelength range from 1.2 to 240 ㎛ of three observed sources were also analyzed.

• Journal of Biomedical Engineering Research
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• v.21 no.3 s.61
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• pp.255-260
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• 2000

This paper presents a radio-telemetry patient monitor. which is used for intensive cal?e units. emergency and surgical operation rooms to monitor continuously patients' vital signs. The radio-telemetry patient monitor consists of a vital sign acquisition unit. wireless data transmission units and a vital sign-monitoring unit. The vital sign acquisition unit amplifies biological signals, performs analog signal to serial digital data conversion using the one chip micro-controller. The converted digital data is modulated FSK in UHF band using low output power and transmitted to a remote site in door. In comparison with analog modulation. FSK has major advantages to improve performance with respect to noise resistance with fower error and the potential ability to process and Improve quality of the received data. The vital sign-monitoring unit consists of the receiver to demodulate the modulated digital data, the LCD monitor to display vital signs continuously and the thermal head printer to record a signal.

• The Bulletin of The Korean Astronomical Society
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• v.27 no.1
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• pp.61-61
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• 2002

• Journal of Astronomy and Space Sciences
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• v.14 no.2
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• pp.320-329
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• 1997

A solar radio spectrograph for monitoring solar radio emission was installed at Ichon branch of Radio Research Laboratory in 1995. The spectrograph consists of three different antennas to sweep a wide band of frequencies in the range of 30MHz~2500MHz. We have developed the operating software for the acquisition and the analysis of solar radio data obtained by solar radiospectrograph in order to carry out active solar radio observational studies. It was found that by using our software, we could have very good solar radio data for a sequence of three TYPE III bursts observed on 4 Nov. 1997. In this paper, we show the radio spectrograph and the result of the observation by its operating software.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.8
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• pp.1952-1962
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• 1998

Radio interference ahs been occurred in TRS service on the south seashore in Korea from 1994. After monitoring the radio signal interference, it is found that the main reasons of radio interference are due to the source stations located at Fukuoka and Yamaguchi in Japan. However, Japan didn't agree about this fact, based on the their technique evaluationof the radio signal; since the distance (about 240-300km) of the radio station between Fukuoka and Pusan is enough to separate from the interference, the radio signal from Digital Mobile Phone is Japan cannot be reached to Pusan area in Korea. In this paper, we verified that the main sources of radio interference are a ducting propagation generated from Japan area by using the computer simulation technique and the measuring data.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.10
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• pp.2019-2029
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• 2009

There are several MCS(Monitoring, Control and Surveillance) systems for maritime safety and security in Korea; VMS (Vessel Monitoring System) that based on the AIS(Automatic Identification System), and the LRIT(Long-Range Identification and Tracking), the Vessel Free Pass System that based on the RFID(Radio Frequency IDentification), the Fisheries Information Network that provided by the National Federation of Fisheries Cooperatives. This paper surveys the fundamental technologies of MCS systems, and compares the role and function of them. It also surveys the development direction of each systems and research topics for cooperation of them.

• International Journal of Computer Science & Network Security
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• v.21 no.6
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• pp.47-53
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• 2021

The article deals with the problems of application of microwave methods in systems of geoecological monitoring of natural environments and resources of the agro-industrial complex. It is noted that the methods of microwave radiometry make it possible, by the power of the measured intrinsic radio-thermal radiation of the atmosphere, when solving inverse problems using empirical and semi-empirical models, to determine such parameters of the atmosphere as thermodynamic temperature, humidity, water content, moisture content, precipitation intensity, and the presence of different fractions of clouds.In addition to assessing the meteorological parameters of the atmosphere and the geophysical parameters of the underlying surface based on the data of microwave radiometric measurements, it is possible to promptly detect and study pollution of both the atmosphere and the earth's surface. A technique has been developed for the analysis of sources of measurement error and their numerical evaluation, because they have a significant effect on the accuracy of solving inverse problems of reconstructing the values of the physical parameters of the probed media.To analyze the degree of influence of the limited spatial selectivity of the antenna of the microwave radiometric system on the measurement error, we calculated the relative measurement error of the ratio of radio brightness contrasts in two angular directions. It has been determined that in the system of geoecological monitoring of natural environments, the effect of background noise is maximal with small changes in the radiobrightness temperature during angular scanning and high sensitivity of the receiving equipment.