• Journal of electromagnetic engineering and science
• /
• v.17 no.4
• /
• pp.241-243
• /
• 2017

In this paper, we have presented an equation for estimating the gain of a Fabry-Perot cavity (FPC) antenna with a finite dimension. When an FPC antenna has an infinite dimension and its height is half of a wavelength, the maximum gain of that FPC antenna can be obtained theoretically. If the FPC antenna does not have a dimension sufficient for multiple reflections between a partially reflective surface (PRS) and the ground, its gain must be less than that of an FPC antenna that has an infinite dimension. In addition, the gain of an FPC antenna increases as the dimension of a PRS increases and becomes saturated from a specific dimension. The specific dimension where the gain starts to saturate also gets larger as the reflection magnitude of the PRS becomes closer to one. Thus, it would be convenient to have a gain equation when considering the dimension of an FPC antenna in order to estimate the exact gain of the FPC antenna with a specific dimension. A gain versus the dimension of the FPC antenna for various reflection magnitudes of PRS has been simulated, and the modified gain equation is produced through the curve fitting of the full-wave simulation results. The resulting empirical gain equation of an FPC antenna whose PRS dimension is larger than $1.5{\lambda}_0$ has been obtained.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.29 no.10
• /
• pp.799-804
• /
• 2018

In this paper, a method for measuring the dielectric constant of a planar dielectric substrate using the free space material constant measurement method in a general measurement environment is proposed. Two horn antennas and a network analyzer were used for S-parameter measurement and the transmission and reflection coefficients of a planar dielectric substrate were calculated from the measurement results. To obtain a reliable dielectric constant in a low-precision-measurement environment, only the magnitude of the transmission coefficient, which has a small error due to the measurement environment, is used for dielectric constant estimation. Finally, the dielectric constant is determined by comparing the measured results at different frequencies.

• Proceedings of the KIEE Conference
• /
• 2015.07a
• /
• pp.579-580
• /
• 2015

Power frequency is one of important operational parameters evaluating reliability, stability, and measuring efficiency of power. Therefore, an accurate and fast estimate of the power frequency is required. The magnitude gains of cosine and sine filters become different when the power frequency is deviated from the nominal value. The proposed algorithm estimates the power frequency based on this. To demonstrate the performance of the proposed algorithm, RTDS and DSP are used. The simulation results show that the algorithm has not only a high level of robustness but also high measurement accuracy over a wide range of frequency changes. In addition, the algorithm was immune to harmonics and noise.

• The Journal of Asian Finance, Economics and Business
• /
• v.4 no.4
• /
• pp.39-49
• /
• 2017

Religious intolerance has become a common feature of many countries in recent times. Studies have revealed a worldwide increase in government regulations and social hostilities against religious beliefs and practices. The stifling impact of both government and society on the market for religion, warrants closer scrutiny. This study examines the relationship between government regulations and social hostilities towards religious beliefs and practices, for the period of 2001-2011 for a sample of 45 European countries. The Generalized Method of Moments dynamic panel estimation technique is employed to analyze the micro panel dataset of 45 European countries, to establish the possible relationships that may exist between these variables. The theoretical framework for this study is based on the Religious Economies Theory and the Supply Side Theory of Religion. The results of this study show evidence of the positive relationship between government regulations and social hostility. Interestingly, the study also revealed that the impact of social hostility on the level of government restrictions is smaller in magnitude compared to the reverse impact of government restrictions on social hostilities, indicating the dangerous role played by governments in inciting social hostilities, when they regulate or restrict religious beliefs and practices.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.15 no.8
• /
• pp.1813-1819
• /
• 2011

In this research, the location positioning system supposed is concerned with range recognition technology using phase and magnitude of radio wave and adding technology of image histogram by vision. By the proposed technology, we design the radio transmitter and receiver and realize the measurement system, and save the data in disk that is earned from 900Mhz RF signal, middle frequency 450Khz of analog signal. Range information is earned the data through digital signal processing of IF signal. For the estimation of range measured, we analyze the difference between real range and measurement range, and also suggest the method to improve the measurement error using average processing and amplitude properties.

• Tunnel and Underground Space
• /
• v.13 no.2
• /
• pp.108-116
• /
• 2003

Measured convergence data of a tunnel were investigated by means of statistical and regression analysis, where the rock mass were mainly composed of andesite and granite. The rock mass around tunnel were classified by RMR method into five different ratings, and then convergence data which belong to individual ratings were statistically processed to find out the appropriate regression equations. Exponential equations were better coincided with measured data than logarithmic equations. As the number of rock mass rating was increased, the magnitude and standard deviation of convergence were increased. Final convergence data were also investigated to study the relevance with both maximum displacement rate and early measured convergence. Some brief results of their relevance are presented. For instance, the regression coefficient between final convergence and maximum displacement rate was turned out to be 0.87 for this studied tunnel.

• Journal of Society of Preventive Korean Medicine
• /
• v.13 no.1
• /
• pp.105-115
• /
• 2009

Background: The resource-based relative value scale has been applied to Korean medicine services as part of the National Health Insurance, yet the proper scoring method for physician's work needs to be developed. Objectives: To measure physician's work for Korean medicine services using Analytical Hierarchy Process(AHP) and to compare results abstracted by AHP with those by Magnitude Estimation method. Methods: We developed the AHP questionnaires for Korean Medicine services and administered it to 12 Korean medicine insurance experts. Weighted scores were calculated and were converted into physician's work scores. Results: In AHP measurement, the physician's work scores for acupuncture activities, especially special acupunctures, far increased, while those for diagnosis and basic consultations decreased. Variations in the scores enlarged. Conclusions: As an alternative, AHP method can be considered for measuring the physician's work for Korean medicine services with careful management of scoring variation.

• Journal of Preventive Medicine and Public Health
• /
• v.38 no.4
• /
• pp.379-385
• /
• 2005

The impact of the next influenza pandemic is difficult to predict. It is dependent on how virulent the virus is, how rapidly it spreads from population to population, and the effectiveness of prevention and response efforts. Despite the uncertainty about the magnitude of the next pandemic, estimates of the health and economic impact remain important to aid public health policy decisions and guide pandemic planning for health and emergency sectors. Planning ahead in preparation for an influenza pandemic, with its potentially very high morbidity and mortality rates, is essential for hospital administrators and public health officials. The estimat ion of pandemic impact is based on the previous pandemics- we had experienced at least 3 pandemics in 20th century. But the epidemiologi cal characteristics - ie, start season, the impact of 1st wave, pathogenicity and virulence of the viruses and the primary victims of population were quite different from one another. I reviewed methodology for estimation and modelling of pandemic impact and described some nations's results using them in their national preparedness plans. And then I showed the estimates of pandemic influenza impact in Korea with FluSurge and FluAid. And, I described the results of pandemic modelling with parameters of 1918 pandemic for the shake of education and training of the first-line responder health officials to the epidemics. In preparing influenza pandemics, the simulation and modelling are the keys to reduce the uncertainty of the future and to make proper policies to manage and control the pandemics.

• Fire Science and Engineering
• /
• v.22 no.1
• /
• pp.10-15
• /
• 2008

In this study, seismic design in sprinkler head pipeline of water extinguishing system has been carried out. This study describes a generation of artificial earthquake wave compatible with seismic design spectrum, and also analyzed the dynamic response spectra by the simulated earthquake motion. This study constructed powerful engineering base for seismic design, and presented seismic design techniques of water and gas extinguishing piping system. Also, this study readied basis that can apply seismic design and performance estimation of fire fighting system and performance rating as well as pipeline of water extinguishing system from result of this research. Hereafter, if additional research by earthquake magnitude and ground kind is approached, reliance elevation, safety raising and performance based design of fire fighting system see to achieve.

• Journal of the Society of Naval Architects of Korea
• /
• v.48 no.3
• /
• pp.238-245
• /
• 2011

Welding inevitably introduces the residual stresses which affect the fatigue strength of the joint structure. The mitigation of fatigue strength depends on the residual stress magnitude and distribution. Stress relief analyses are of practical interest for all cyclic loaded welded structures, such as ships and offshore structures. In order to estimate the effects of relaxation of residual stresses in the welded structure, this paper presents a finite element analysis procedure and experimental results for the welded structure. Cruciform specimens joint by MAG welding have been tested to measure the released stress. Relieved welding residual stresses obtained by finite element analysis are compared with those measured by experiment.