• Journal of Satellite, Information and Communications
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• v.9 no.2
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• pp.80-84
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• 2014

As an integrated technology with IT and biomedical sciences, U-health offers various healthcare services without time and space limit. In order to make a proper diagnosis, doctors need two key technologies: biosignal measurement and high reliability communication technologies. In this paper, we introduce an implementation process of a bio signal system with using an electrocardiography(ECG) sensor, video, global positioning system(GPS), communication module and micro controller unit(MCU).

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.3A
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• pp.296-301
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• 2011

GPS(Global Positioning System) service is more important than other wireless services. The GPS is necessary protected from any other interference signals. Therefore, GPS protection ratio was calculated on the basis of bit error rate(BER) in this paper. Simulation results show that the allowable maximum interference power is -190 dBm/Hz and the ratio of interference to noise(I/N) is -16 dB. The achieved protection ratio is available to be applied as the protection criteria of GPS in considering the implementation margin of 4 dB. As a result, the proposed protection ratio of GPS is expected to give standard for a stable GPS service.

• Journal of Satellite, Information and Communications
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• v.10 no.4
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• pp.46-51
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• 2015

In this paper, I design a linear array antenna simulator for anti-jamming GPS systems and perform various performance analysis by simulation. First, I generate simulated transmission signals through the analysis of GPS satellite signal structure, and analyze SNR(Signal to Noise power Ratio) performance of linear array antenna according to number of arrays under noise environments. In addition, I analyze the performance of the anti-jamming beam pattern using MMSE(Minimum Mean Square Error) signal processing method, and also analyze the anti-jamming performance considering antenna calibration problem when there are different delays between arrays.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.8C
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• pp.745-757
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• 2007

In this paper, we propose a design of GPS anti-jamming system and its operational method, which can effectively suppress interference and jamming signals induced in GPS receiver. The 7-array antenna used in the proposed system is composed of conventional 6 equi-spaced circular elements with one element on the center of antenna and can be efficiently operated under power-constrained conditions. Futhermore, in this paper, we analyze the structure and complexity of STAP and SFAP which are well known techniques in adaptive array antenna signal processing, and we compare the BER performances between STAP and SFAP in various jamming environment based on the same complexity.

• Proceedings of the KIEE Conference
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• 2007.10a
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• pp.355-356
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• 2007

21세기는 한국 철도의 르네상스시대라고 부르고 있다. 이는 자동차와 비행기 등 다른 교통수단에 의해 낙후되어있던 철도가 다시 안전하면서도 정확한 운송시간 등으로 그 경쟁력을 확보해가고 있으며 때를 같이하여 고속철도의 개통을 앞두고 있기 때문이다. 이러한 철도의 경쟁력을 강화하는데 크게 기여한 부분 중 하나가 신호 보안장치 즉 열차제어장치의 발전에 있다고 하겠다. 하지만 열차를 제어하기 위해선 실시간격으로 열차의 절대 위치를 알아야만 하는 문제점이 있다. 이를 비교적 쉽게 극복할 수 있는 방법 중 하나가 인공위성을 이용한 통신기술을 이용하는 것이다. 이는 이미 다른 분야에서는 상용화되어 서비스가 이루어지고 있는 GPS(Global Positioning System)이다. 본 논문에서는 열차의 절대 위치를 GPS(Global position system)를 이용하여 구해 보고자 한다. 이를 위해 GPS 신호 추적을 확장형 칼만 필터를 적용하여 열차의 속도 변화에 대한 GPS 신호 추적 루프를 예측 제어함으로써 보다 정확하고 빠른 GPS 위치 정보를 도출하였다.

• Journal of Astronomy and Space Sciences
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• v.16 no.2
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• pp.285-292
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• 1999

To determine a geographical position by GPS signal, the effect of the ionosphere must be considered to improve accuracy. This has led us to continuously try to find the TEC of the ionosphere by using the GPS signal. So far the way to find TEC has been developed and the information obtained from this can be used not only to increase the accuracy of determining the position, but also to study the ionosphere. In this research, the TEC MAP over Korea was obtained by using the data collected from eight GPS stations around the Far East Asia, which is the common way to represent TEC over some regional or global region.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.1
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• pp.61-68
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• 2017

In this paper, the coarse acquisition code (C/A code), for civil navigation, of the ranging codes for Global Positioning System (GPS) is studied, simulated and analyzed by using Matlab. We can see with the simulation results that the correctness of the method and feasibility, which is at simulation platform to further study on the real environment of GPS signal, can be confirmed. With using this results, we think, the complexity of tracking the satellite signal environment can be captured, and the performance of satellite receiver will be improved.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.1
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• pp.70-78
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• 2013

Before GBAS ground systems is installed at the airport, the site survey is needed to determine the suitability of proposed GBAS candidate sites depending on the siting requirements. Therefore, analysis of GPS signal reception environment, one of the site survey steps, is required. In this paper, the number of visible satellites, GPS signal strength, multipath error, radio frequency interference and predicted availability were analyzed using the GPS data of Gimpo International Airport measured by PortaSAT equipments and the analysis results were represented.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.15 no.3
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• pp.52-59
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• 2016

COSMOS system which was developed in Seoul for real-time signal control was designed to judge traffic condition for practicing signal operation. However, it occurs efficiency problem that stop line detection and queue length detection could not judge overflow saturation of street. For that reason, following research process GPS data of Seoul city's corporationowned taxi to calculate travel speed that excluded existing system of stop line detection and queue length detection. Also, "Research of calculating queue length by GPS data" which was progressed with following research expressed queue length. It is based on establishing algorithm of judging congestion situation. The algorithm was applied to a few areas where appeared congestion situation consistently to confirm real time traffic condition with established network. [Entrance of the National Sport Institute ${\rightarrow}$ Gangnam station Intersection, Yuksam station intersection ${\rightarrow}$ National Sport Institute.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2015.10a
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• pp.279-282
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• 2015

Fisheries development of the basic law pursuant to article 15 (marine safety management, etc.) one of maritime safety and maritime traffic facilities nationwide network of DGPS in accordance with the building maximize infrastructure utilization and country. Source technology has been improving steadily raised for the benefit daegukmin. In particular, look at the type of product for the marine supply medium-wave receiver Performance products that satisfy most of the IMO Advisory. The antenna and receiver are separate structural supply for some integrated model with a very high Rather it is used as a portable receivers for marine positioning cheap integrated model development is needed. Correction of satellite navigation receivers for the current Marine GPS module, medium-wave modules can be developed one low cost Integrated in independent operating environments do not support the model development done look at what the problem is 285kHz ~ 315kHz in DGPS Beacon receiver structure using a medium wave or Beacon The medium-wave antenna and a GPS receiver signal to noise ratio was studied GPS signal attenuation on the DGPS performance looked at each GPS manufacturer medium-wave signal-to-noise ratio and normalized impact by GPS manufacturers noise power ratio per bandwidth for medium-wave GPS signals affect it was implemented to improve performance.