• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.2 s.117
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• pp.166-176
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• 2007

Measurement uncertainty assessment is very important in measurement and calibration. RRL provides antenna calibration services for EMI test. Reliability of EMI test depends on accurate antenna calibration. Antenna calibration results have to be accompanied with measurement uncertainty for its better reliability. In the late of 2005, CISPR issued the CISPR/A/644/C which describes the antenna calibration and measurement uncertainty. In this paper, on the basis of CISPR/A/644/C, we provide the measurement uncertainty values for dipole antenna calibration at the Calibration Test Site(CALTS) of Icheon. The antenna calibration method is 3-antenna height-scanning-averaging method, which measures the free-space antenna factor. We also considered all uncertainty sources that can affect measurement results during calibration.

• Journal of the Korean Institute of Gas
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• v.2 no.3
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• pp.60-69
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• 1998

Methane, the major constituent of natural gas, had been converted to higher hydrocarbons by microwave and radio-frequency plasma in vacuum condition. Methane had been activated to plasma by suppling high energy then converted to ethane, ethylene, acetylene. The direct conversion process of methane had produced few by-products and demanded low-energy. The plasma sources were microwave and radio-frequency. Two types of reactor had been used to activate methane. One is common single tubular-type reactor and the other is series coil-type reactor which used for the first time in this study. To produce more C2 products, methane had been converted by a plasma and catalyst. The results of this study could be used to study mechanism of plasma reaction of methane, design the plant-scale reactor.

• 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.

• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.6
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• pp.1245-1258
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• 2023

To efficiently manage forest resources, it is essential to deploy multiple unmanned aerial vehicles equipped with various sensors simultaneously. Consequently, the ground control station antenna should not only maintain continuous tracking of the target station but also minimize the impact of radio interference on other unmanned aerial vehicle stations. In this paper, we presented beam forming techniques based on the VPR algorithm within a ground control station constructed using a phased array antenna system. Through simulation experiments in diverse unmanned aerial vehicle operating environments, it was demonstrated that the presented method enables not only the continuous tracking of operational unmanned aerial vehicles but also the suppression of radio interference by establishing a continuous pattern null for multiple operational radio interference sources.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.2
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• pp.80.1-80.1
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• 2014

We made simultaneous surveys of 22 GHz water and 44 / 95 GHz methanol masers toward 299 high-mass protostellar objects using the Korea VLBI Network (KVN) 21-m telescope. The sources were selected from the catalog of Red MSX Source (RMS) survey. Initial selection of the sample present high-mass protostellar objects in an evolutionary phase prior to ultra-compact HII regions, which have bolometric luminosities > $10^3L_{\odot}$ but are not associated with any radio continuum emission. After the follow-up work of ongoing RMS survey, final samples contains 56 sources classified as HII regions. We performed a simultaneous survey of 22 GHz water and 44 GHz methanol masers in 2011 and then conducted a simultaneous survey of 22 GHz water and 44 / 95 GHz methanol masers in 2012. The primary scientific goals of these surveys are to investigate the relationship among the three masers and to explore the relationship between each maser and the central star or the parental dense core. The detection rates of two epochs are 42% and 38% for water, 25% and 26% for 44 GHz methanol, and 23% (2012 only) for 95 GHz methanol masers. We performed a statistical analysis on subsample associated with a large data found in literature. In this poster, we will the preliminary data analysis results and discuss the implications.

• Journal of the Korean Home Economics Association
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• v.23 no.4
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• pp.101-108
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• 1985

The completely answered questionnaires were analyzed for the nutrition knowledge, food habits, value orientation, and the sources of nutrition information of housewives of 20's to 40's. The subjects had a high level of perceived knowledge, that is the knowledge that each subject believed she hadm but the accuracy of the knowledge was only 51.6%. The mean nutrition knowledge score was 6.63 out of possible 15 points, and food habit score was 5.31 out of 10 points. Most of the subjects belonged to "Good" to "Fair" food habit group, which is considered to be relatively good. With increasing age and decreasing level of education, the percent of perceived knowledge and accuracy, and nutricion knowledge score were getting lower. However, the food habit score was getting higher with increasing age. This suggests that food habit was dependent more upon the length of married life than the nutrition knowledge in housewives. The corelation between nutrition knowledge score and food habit score was low. The economic area was the most concerned area of the subjects, followed by health and social. The scores of utrition knowledge and food abits of the subjects who ranked the health the highest were not different from those of economic and social. TV, radio, newspapers, and magazines were the most important sources of nutrition information.

• The Bulletin of The Korean Astronomical Society
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• v.35 no.1
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• pp.51.2-51.2
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• 2010

We have carried out an extensive statistical analysis based on the results of simultaneous observations of SiO and $H_2O$ masers toward 166 known SiO and $H_2O$ maser sources using KVN_Yonsei radio telescope (Kim et al.2010, ApJS submitted). We investigate the distributions of the mean velocities and the intensity ratios between SiO and $H_2O$ maser emission including those between SiO v=1 and v=2,J=1-0 transitions according to type of evolved stars. We also investigate mutual relations between SiO and $H_2O$ maser properties(total flux densities and velocity structures etc.) according to stellar pulsation phases. Most of SiO masers appear around the stellar velocity (80 % within ${\pm}5km\;s^{-1}$), while $H_2O$ masers show a different characteristic compared with SiO masers (69% within ${\pm}5km\;s^{-1}$). In addition, we investigate a correlation between $SiO/H_2O$ maser emission and AKARIFIS flux density as well as the AKARI color characteristics of SiO and $H_2O$ observational results in the AKARIFIS two-color diagram.

• Journal of Information Science Theory and Practice
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• v.1 no.1
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• pp.42-53
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• 2013

Timely access to quality healthcare information during an outbreak plays an important role in curtailing its spread. The aim of this study was to investigate the information needs and seeking behavior of the general public in Singapore during the H1N1 pandemic. A pre-tested questionnaire was used for data collection. The convenience snowball sampling method was used and 260 working adults and tertiary-level students participated in this study. The most crucial information needs of a majority of the participants were: symptoms of H1N1, causes of the infection, preventive measures, and possible treatments. Data analysis also revealed that mass media such as television, newspapers, and radio were most frequently used for seeking the needed information. The use of human information sources was also quite high while only a small number of the respondents accessed online news and healthcare websites. About three-quarters of the participants indicated that the gathered information helped them to stay vigilant and take necessary precautionary measures. A major problem identified by the participants in using H1N1 information was the lack of understanding of certain terms used in public communications. This paper suggests certain measures for strengthening health information communication during future outbreaks.

• Journal of the Korean Home Economics Association
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• v.26 no.4
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• pp.15-30
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• 1988

The purpose of this study is to collect basic data which will be effective in performing nutrional education. This study was conducted at Taegu area and adjacentrural area from June to July in 1986. The completely answered questionnaires were analyzed for food habits, purchase of food, the sources of nutrition information and general characteristics of housewives of 20's to 50's. The results obtained are summarized as follows ; 1) The major food of breakfast was boiled rice (93.9%). With decreasing level of education and in rural area, the percent of boiled rice was higher. 2) The frequency of eating out with family is higher in urban area, younger age, and nuclear family. 3) The preference for eating between meals appeared in order of bread and cakes, cookies, and the others. 4) The preference for desserts appeared in order of fruits, coffee, the other, coarse tea, adlay tea, and gingseng tea. 5) The purchasing place for vegetables and fruits was market (53.5%) on the whole, but in rural area, the percent of self production was higher (63.6%). 6) With increasing age and decreasing level of education, the percent of accuracy of nutrition knowledge was lower. 7) Sources in the knowledge of nutrition appeared in order of Radio and T.V., relatives, cookbooks, newspapers and magazines, lectures in cooking school. In order to promote nutritional status of family, nutritional education for housewives must be accomplished in the first place.

• International Journal of Knowledge Content Development & Technology
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• v.11 no.4
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• pp.35-51
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• 2021

This study measured the effects of fake news and propaganda on managing information on COVID-19 among the Nigerian citizenry. This study examined sources of information on COVID-19 available to the people, evaluated reasons behind spreading fake news, examined how fake news has affected the spread of COVID-19 pandemic in Nigeria, established the consequences of fake news on managing COVID-19 pandemic and as well identified ways to contain fake news at a time like this in Nigeria.It is a survey with a sample size of 375 participants selected using simple random technique. Instrument of data gathering was questionnaire widely distributed in the six geo-political zones of Nigeria using Survey monkey. Data was analysed using frequencies, counts and percentages, tables and charts. Findings revealed that people rely more on radio, television, and social media for information on COVID-19. Fake news is spread by people mostly for political reasons and intention to cause panic. In Nigeria, fake news has led to disbelief of the existence of the virus thereby leading to violation of precautionary measures among the citizenry and lack of trust in the government. Concerted effort on the part of the government is required to give public enlightenment on the danger of fake news. Also, directorate of anti-fake news should be established to censor and reprimand sources of fake news. People should always check source of information to confirm its credibility and be weary of sharing unconfirmed information especially on the social media.