• Journal of Broadcast Engineering
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• v.5 no.2
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• pp.211-219
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• 2000

The IBAC DAB system was interfered by existing FM broadcasting signal as was used guardband within existing FM broadcasting. The FM interference signals are very important parameter in performance evaluation of IBAC DAB system. We got the characteristic of FM PSD in according to instantaneous change and average characteristic of FM broadcasting signal in according to characteristic of FM channel. In this paper, based on proposed IBAC DAB system, we analyze effects of FM interference for occupied bandwidth and performance of IBAC DAB modeling various FM interference signals with sum of sinusoid function using C language, suggest FM interference ratio that can maintain performance. We was know that IBAC DAB system have a great performance variation in according to average characteristic of FM PSD by simulation results, also, FM interference ration that can maintain performance of system is 10dB.

• Journal of Korea Spatial Information System Society
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• v.2 no.2 s.4
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• pp.39-48
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• 2000

The purpose of this study is to develop a converting algorithm for providing real-time traffic information through the FM DARC(DAta Radio Channel). The converting algorithm based on the GIS node-link system enables raw traffic data to be a standard traffic information. The standard traffic information in data quality, quantity and format is an essential to construct the FM DARC traffic information system effectively. We have developed the algorithm and applied it to the FM DARC system. After introducing FM DARC briefly, this paper presents GIS DB, the converting algorithm and the client/server FM DARC system.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.9 no.1
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• pp.98-107
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• 1998

For implementation of FM-DS/SS system. This paper has analyzed SO(Synchronous Oscillator) being oscillated by the motivation of injected signal. Transmitter has adopted FM-DS/SS modulation method using RF output-signal of FM. Receiver is used SO to demodulation of FM-DS/SS and applied sliding correlator for synchronization of PN clock. As a result of the inspection, SO presented stable lock ability in spite of doppler apperance and proved the synchronous properties of it in the FM-DS/SS system.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2001.10a
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• pp.413-418
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• 2001

민첩생산의 필요성이 날로 증가하고 있는 생산환경 하에서 대표적인 자동생산시스템인 FMS의 효율적인 운영과 동시에 원격지에서의 FMS 모니터링 및 제어는 필수화되고 있다. 최근에 시뮬레이션을 기반으로 하는 가상생산의 개념이 일반화되고 이를 지원하는 다양한 정보기술의 발전에 따라 FMS에도 적용되고 있다. 본 논문에서는 웹환경 하에서 실재 FMS와 이에 대응되는 가상 FMS를 통합함으로서 원격지에서의 효율적 운영을 지원하는 모니터링 및 제어시스템 구축방법을 소개하고자 한다. 또한 키트형 FMS와 이에 대한 가상 FMS 모델를 대상하여 적용한 결과를 소개하도록 한다.

• Journal of the KSME
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• v.27 no.5
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• pp.441-446
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• 1987

FMS는 절삭가공용으로 발전되어 왔으나 최근에는 조립을 포함한 소재공급부터 제품의 조립에 이르기까지 제품을 일괄 생산하는 총합적 시스템으로 확장되어 가고 있다. FMS의 조립시스템 으로는 조립센터에 의한 것과 조립로봇을 이용한 것 등의 개발이 추진되고 있다. FMS의 전반 적인 발전추세를 보면 총합적 시스템으로 나아가고 있다고 보는데, 이를 위해 그 주변시스템과의 효육적인 연계와 산업용 로봇의 적극적인 활용 등에 대한 연구가 활발하게 진행 될 것이다. 한편, 공작기계들은 범용기계에서 벗어나 완벽한 컴퓨터제어가 가능하고 시스템지향형의 특수목저기 계들이 많이 고안되고 실용화될 것으로 전망된다. 그리고, 시스템의 유연성을 높이기 위하여 작업물 운송시스템의 무유도방식에 대한 비약적인 발전이 이루어질 것으로 기대된다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.10 no.6
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• pp.835-846
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• 1999

In this experiment I have made FM-DS/SS system replacing 170.120 MHz by utilizing FM transmitter and receiver. In the transmitter, the result shows that the modulated FM-DS/SS signal is a typical $(sin \chi/\chi)^2$ spectrum by using the clock(1.329 MHz) of PN divided from FM carrier. In the receiver, SO(Synchronous Oscillator) was applied to despread. Like figure 1, 2, and 4 when I applied SO, which consists of sliding correlator, to synchronous a favorable properties could be obtained in the receiver of FM-DS/SS system. In this paper, I used SO in order to take synchronous in the construction of FM-DS/SS system, and to support it I presented the result of the experiment on synchronous curve and properties of OS.

• Journal of Broadcast Engineering
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• v.5 no.2
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• pp.199-210
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• 2000

The IBAC (In-Band Adjacent-Channel) DAB (Digital Audio Broadcasting) system is to provide multichannel CD quality audio services and multimedia data services including text and picture in FM band (88~105 MHz). As the FM band is being used by the existing analog radio broadcasting, there must he an analysis of the interference effect between IBAC DAB and analog FM signal. Therefore, the protection ratio should be evaluated to verify the system compatibility and allocate the new IBAC DAB channel in FM band. In this paper, among the three types of interferences, FM-to-DAB, DAB-to-FM and DAB-to-DAB, that can be occurred, the Protection ratio of IBAC DAB system for co-channel FM interferer is analyzed by modeling the FM interferer and considering the multipath fading channel. The simulation results show that IBAC DAB system has far better sensitivity than Eureka 147 and needs a relatively high protection ratio for co-channel FM interferer, because of its narrow bandwidth, about one third of that of Eureka 147.

• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.10
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• pp.1183-1188
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• 2015

The FM-QCSK(: Frequency Modulated Quadrature Chaos Shift Keying) system is one of the most efficient systems in chaotic literature. One of the problems in this system is that half the bit duration is used for sending a chaotic reference signal which leads to increase the energy losses and reduces the data rate. In this paper, a novel scheme to enhance the performance of FM-QCSK system has been proposed. With the proposed scheme, FM-QCSK would be able to operate at higher data rates with reduced BER(: Bit Error Rate) and energy consumption. The basic modification introduced by the proposed scheme is the use one reference chaotic signal to transmit multi information signals in both in-phase and quadrature-phase channels. The results showed that the proposed scheme have achieved more than 3 dB gains in SNR for AWGN channels respectively at $BER=10^{-3}$ over the conventional one. The results also showed that the optimum number information signals can be send per reference signal is 8.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1998.06a
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• pp.59-66
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• 1998

교통정보와 DGPS(Differential GPS) 보정신호의 전송은 ITS(Intelligent Transport System)의 핵심 응용분야인 차량항법시스템(CNS : Car Navigation System)의 동적경로안내(Dynamic Routine Guidance System) 시스템의 핵심적인 요구사항이다. 이 정보들은 서비스 특성상 넓은 지역을 수신지역으로 하고 24시간 연속적으로 전송이 되어야 한다. 즉 주행주인 차량에서 자신의 위치 정확히 파악하기 위한 DGPS 보정신호 및 사고, 교통통제나 체증 등의 교통사항을 항상 수신할 수 있도록 항시 전송이 되어야 한다. FM 방송을 활용하여 이러한 요구사항을 충족시키는 전송채널로 활용될 수 있음을 확인하기 위해 FM 방송과 DARC 방식의 부반송파 시뮬레이터가 제작되었으며 이 시스템의 특성이 연구되었다. 또한 정보데이터를 현용 FM 방송설비를 이용하여 전송하기 위한 방송시스템을 제작하고 서울 및 경기도 지역을 수신지역으로 한 방송수신상태의 측정이 수행되었다. 이 결과들은 FM 부반송이 ITS를 위한 전송채널로서 활용될 수 있다는 것을 보여준다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.8 no.4
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• pp.363-372
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• 1997

We have developed the UHF CW/FM proximity sensor system. The UHF CW/FM Proximity Sensor is the system which recognizes the distance from the antenna to the target using the UHF band signal. To adjust sensing distance, we must change modulation frequency parameter or modulation index parameter. When we select the modulation frequency paramter for adjusting sensing distance, new modulation frequency generator and new band pass filter will be required. It is so inefficient that we choose modulation index parameters for adjusting sensing distance. In this paper, theoretical principles of the UHF CW/FM Proximity Sensor are analyzed and doppler signals for the distance from the antenna to the target are measured as the modulation index($\beta$) being changed. Three systems of which moduation indices are 38, 50, and 61 are made. We concluded that the sensing distance will decrease as the modulation index($\beta$) increases. It is in accord with the theory of this UHF CW/FM Proximity Sensor System.