• Journal of Navigation and Port Research
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• v.28 no.10 s.96
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• pp.869-874
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• 2004

Digital TV broadcasting's resolution or tone quality is very excellent than analog broadcasting and has many advantages including various multimedia functions such as home shopping, home banking, internet search, telecommuting, VOD, etc. In this study, it is essential to analyze the regional electromagnetic environment before Digital TV broadcasting, and therefore we analyzed Busan area's limitation using ETRI propagation model. For maintaining high-quality Digital TV signals, we measure electric field intensity wide and far in Busan including mountains area and high-rise buildings. Generally, it has lower value by a standard ETRI propagation model than simulated value about standard model, but distribution pattern are similar with it. Compared theoretical values with the measured results, they have similar values for flat area but very different values for crowded city area and mountains area So we conclude that ETRI propagation model and theoretical model are not suitable for Busan in a free space.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38A no.9
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• pp.765-772
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• 2013

In this paper, we studied the path loss model of Air Traffic Control(ATC) telecommunication radio channel at the Incheon International Airport(IIA) concourse area. We measured wave propagation characteristics on the two frequencies among VHF/UHF channel bands. The transmitting site radiated the Continuous Wave(CW). The propagation measurement was taken using the moving vehicle equipped with receiver and antenna. The transmitting power, frequency, and antenna height are the same as the current operating condition. The path loss exponent and intercept parameters were extracted by the basic path loss model and hata model. The path loss exponents at Concourse area were 3.1/3.13 and 3.01/3.38 respectively in 128.2MHz and 269.1MHz. The deviation of prediction error is 2.77/3.17 and 4.01/3.66. The new path loss equation at the Concourse area was also developed using the derived path loss parameters. The new path loss model was compared with other models. This result will be helpful for the ATC site selection and service quality evaluation.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.13 no.7
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• pp.726-731
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• 2002

The purpose of this paper is to analyze the path loss for the mobile cellular system. The maximum distance is 150 km and the area is about 6,000 $\textrm{km}^2$ and the field test was performed for the total 5 base stations. The path loss was calculated by Hata and Okumura models, respectively. As a result, it was shown that a proper model for the field test data is the middle one between the rural model and suburban/rural Hata model.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.4
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• pp.73-80
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• 2013

In this paper, an experimental circuit model for an accurate high-frequency characterization of transmission line is proposed. Inherent resonance effects during measurements make it difficult to determine characteristic impedance and propagation constant at the resonance frequencies corresponding to the line length. Thus, resonance-effect-free transmission line parameter determination technique based on the physical insight and theory is proposed. Then, by using the parameters high-frequency circuit model is proposed for high-speed signal propagation characterization. The proposed frequency-variant transmission line model is verified with measurement and it can be usefully exploited in high-speed signal propagation characterization.

• Electronics and Telecommunications Trends
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• v.15 no.1 s.61
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• pp.38-40
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• 2000

자동 요금 징수 시스템인 ETC(Electronic Toll Collection) 시스템에서 차량의 탑재장치와 비컨(Beacon) 간에 마이크로파가 전파되는 경로를 모델화하였으며 다중 경로에 따른 페이딩 효과를 분석하였다. 또한 환경 변화 즉 강우 시 마이크로파 전파도 고려하여 수치분석을 하였다. 분석결과 강우에 의한 반사면의 반사계수가 변하여 페이딩 효과가 크게 증가하였다. 이런 수치해석 결과를 탑재장치에서 수신된 전압의 크기와 비컨과 차량 사이의 거리로 도시하였다.

• Proceedings of the KAIS Fall Conference
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• 2008.05a
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• pp.258-260
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• 2008

본 논문에서 다중경로 전파환경에서 전파특성을 연구하였다. 목표지점에서 전계의 세기는 직접파와 지면 반사파의 합으로 구성된다. 이 논문에서는 지면의 반사를 고려하여 목표물 근처 공간의 3차원 전계분포를 계산하는 프로그램을 개발하였다. 실제 목표물의 궤적에 따라 목표물의 수신기에서의 신호세기를 예측하는 3차원 모델을 개발 하였다.

• Journal of Advanced Navigation Technology
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• v.28 no.3
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• pp.278-287
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• 2024

In this paper, telemetry link budget model for small launch vehicle is proposed, and telemetry link budget simulator is implemented. The proposed link budget model consist of geometry model and propagation loss model. The geometry model is calculation of look angle between ground station and small launch vehicle. The propagation loss model consist of free space loss, polarization loss, and de-pointing loss which are appropriate to the small launch vehicle flight environment. The proposed propagation loss model can be calculate propagation loss without complex calculation of propagation environments. The link budget simulator is implemented in MATLAB. The simulator calculate look angle, free space loss, polarization loss parameter, de-pointing loss and received signal level in ground station by using position of ground station, routing of small launch vehicle, 3-D radiation patterns of antennas.

• Journal of Advanced Navigation Technology
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• v.17 no.5
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• pp.484-490
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• 2013

With the rapid development of wireless communication at VHF and UHF bands, there is an increasing need for the reliable propagation prediction tools. Therefore, the different propagation models that have been developed in many countries as well as korea has been trying to secure a model suitable for their geographical area but then it is giving us a different result when we compared it to measured values. In this paper, based on the measurements of DTV broadcasting services in domestic urban area, analysis and comparison of ITU-R P.1546 and BCAST models provide errors between measured and predicted values, and some points for improving SMI system has been proposed. As a result, P.1546 model provides the valid predicted data similar to measured data, but BCAST model has some problems of large deviation and higher prediction to measured data. In future, these problems and diffractions due to high buildings need to be studied further.

• 한국경영정보학회:학술대회논문집
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• 2007.11a
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• pp.417-422
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• 2007

개인 휴대 단말에 전파식별(Radio Frequency Identification) 기술이 결합됨에 따라, 전파식별 기술의 활용이 기존의 유통, 물류 등 B2B의 영역에서 벗어나 B2C영역으로 확대될 것으로 예상됨에 따라, 업계에서 다양한 시도가 이루어지고 있다. 본 논문에세는 인프라가 충분하지 않은 제약 조건하에서 인프라를 공급하면서 구현 가능한 비즈니스 모델로서 서비스 공간 내에서 RFID 태그가 부착된 테이블(Tag-Table)을 이용하는 B2C 비즈니스 모델과 애플리케이션을 제시하고 분석하였다. 본 논문에서 제시하는 비즈니스가 이뤄지기 위해서는 태그 테이블이 위치할 공간 제공자의 참여 여부가 중요하므로, 공간 제공자의 비용/수익 분석을 중심으로 비지니스 모델의 유효조건을 분석하였다.

• The Transactions of the Korea Information Processing Society
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• v.7 no.8
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• pp.2520-2527
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• 2000

An improved transition density propagation method for power estimation is proposed. The power estimation for the zero delay model is a proper criteria for the.lower boutldlIry for power consumption. A transition propagation method, including the zero delay model as a lower boundary for power stimation was studied. However, there were some redundancy factors in the process of transition density propagation. Hence this paper will explore the transition density propagation behavior to eliminate the redundancy factors and present theirriprQved estimation methodology for the signal transition density. The experiments show that the proposed method has comparably better estimation accuracy than the conventional methods.