• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.17 no.1
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• pp.37-44
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• 2003

This paper proposes on-line based a deterioration diagnosis pole transformers using various sensors such as thermistor, current transformer and potential transformer. We measured load current and temperature to diagnose pole transformer using R/F( radio frequency ) wireless data communication module. We represent the graphs of their feature. The result of this paper shows that the proposed device car be used as deterioration diagnosis device of pole transformers.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2003.11a
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• pp.233-236
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• 2003

본 논문에서는 차량용 음성명령어기의 사용을 위한 전처리 과정으로 음성개선 방법을 다룬다. 특히 DMB 사용환경에서 보다 주위 소음에 자유롭고 단말 조작에 있어 안정성을 보장하기 위하여 일반적 단인 마이크로폰으로 처리되는 잡음뿐만 아니라 음성명령어를 제외한 오디오 신호 등 비정적 통계적 특성을 갖는 소음들도 제거 될 수 있도록 음성개선 방법을 제안한다. 우리는 2개의 마이크로폰을 가지고 BSS 알고리즘을 적용하여 비정적 신호들을 분리하고, 분리된 신호에 대하여 Kalman Filter를 이용하여 시간상 단구간 정적 잡음을 제거한다. 본 논문의 인식 실험 결과를 통하여 공간적, 시간적 음성개선 방법이 순차적으로 적용될 때, 실제 차량 환경에서 음성 개선 알고리즘으로 적용될 수 있음을 보였다

• Journal of the Korea Society of Computer and Information
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• v.24 no.7
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• pp.71-78
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• 2019

This paper describes a design for a RF receiver to receive satellite digital audio service. The RF receiver designed in this study is a planar structure that is easy to install on the rooftop of a car and is compact in size. In addition, it can be applied to certain commercial models because it has low noise and high gain characteristics. The impedance bandwidth of antenna is 17.8%(415MHz), and the axial ratio is below 3dB as good properties for the bandwidth of 40MHz which is a satellite digital audio service band. Also, it had a broad radiation beamwidth of $95.41^{\circ}$ in H-plane and $117.45^{\circ}$ in E-plane. From the results of the field test of satellite digital audio service reception for the RF receiver, it demonstrated good C/N rate(10.2dB).

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.5 no.4
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• pp.83-93
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• 1994

1886년 고트리브 다이믈러와 칼 벤즈가 가솔린 자동차를 개발한 이후 100여년이 지난 지금 자동차는 비약적으로 진보, 발전하여 현대 산업사회와 개인의 생활에 있어 산업운송수단과 이동수단으 로서 필요불가결하게 되어 밀접한 관계를 갖고 있다. 우리나라 자동차 공업의 역사는 자동차가 사회적, 경제적 효용에 따라 그 생산과 보유대수가 날이 갈수록 증가 일로에 있으며, 자동차의 생산대수는 전세 계에서 년간 약 50,606천대('94년)로서 중요한 국가 기간 산업으로 자리하고 있다. 한편 전기, 전자공업의 발전에 따른 자동차의 Car Electronics가 많이 채용되게 됨에 따라 현재의 자 동차에는 대부분이 전자제어 System으로 구성되어 있다. 최근에는 Micro Processor를 이용한 전자부품이 많이 사용되어 전자파에 대한 문제가 다양하게 발생 하고 있다. 예를 들면 미국 캘리포니아주에서 전자점화제어장치와 연료분사 장치를 설치한 구미의 자동 차가 주행중 28MHz, 28W의 아마추어 무선을 탑제한 자동차가 통과할 때 엔진이 고르지 못한 보고가 있 었고, 화학섬유로된 옷을 착용한 전자부품이 다른 부품에 영향을 주는 사례가 맣아지고 있다. 따라서 자동차에는 여러가지의 전장품, 전자기기를 탑재하기 때문에 자동차 자체에서 발생하는 것과 외부로 부터 받는 전자장해 EMI(Electromagnetic Interference), EMS(Electromagnetic Susceptibility) 가 문제로 되어 자동차 및 부품 maker에 의한 EMC(Electromagnetic Compatibility) 평가의 중요성이 고조되고 있다. 차제무전기, 차제무전기, Car-Radio는잡음방해를 많이 받기도 하지만, 잡음원이 되기 도 한다. 또한 Engine 제어, 차속제어, Brake 제어등에 이용되는 전자제품은 방해에 의한 오동작 또는 파괴가 발생하여 주행기능, 안전성에 문제가 야기되지 않도록 해야 한다. 이러한 전자기 환경은 모두 RF(Radio Frequence)와 자동차에서의 전자파 장해 문제의 원이 될 수 있다. 자동차 및 그 부품의 전자기 방해에 관한 규격화는 1987년부터 괄목할 만하게 진행되어 이에 따른 규제 움직임이 IEC(International Electrotechnical Commission: 국제전기기술위원회) 산하의 하부기 구인 CISPR(International Special Committeeon Radio Interference: 국제 무선 장해 특별위원회)가 전자기 방해파에 대한 측정법 통일안을 제안 하였고, ISO(International Standardization Organiza- tion: 국제표준화 기구) 가운데 TC 22/SC3가 자동차의 전장품에 대한 장해를 논의히고 있다. 특히, 자동차의 EMC에 관한 국가 규격은 국제 규격에서 저술한 바와 같이 특별히 규정된 것이 없고 VDE(Verband Deutscher Elektrotechniker: 서독전기기술 협회)와 SAE(Society of Automotive Engi- neers: 자동차 기술자 협회)에서 비교적 활발하고 Jaso(Japanese Automobile Standards Organization: 일본 자동차 표준협회)에서 많이 진행중에 있다. 본 고에서는 자동차의 전자제어에 따른 잡음 발생 요인과 전자파 간섭 관련 자동차 규격과 시험평가 방법에 대해 간단히 소개 하였다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.12B
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• pp.1452-1458
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• 2009

In this paper, Our proposed Multipurpose Complex Card UHF band RFID small-size Tag antenna. Multi purpose Complex Card UHF band RFID small-size Tag antenna that is to minimize the low efficiency of RFID Tag Read Range that generates space limitation and a conductor surrounded by inducing fingerpring system with dual(HF, UHF) Card is presented. Our proposed UHF band RFID small-size Tag antenna is for the Multipurpose Complex Card that is mounted on the fingerpring system as well as the HF Tag. It also enables to minimize and facilitates Tag chip matching by adjusting Tapered, Meander line and Loop structure. Given the card substance properties and periphery circuit, the proposed small-size Tag antenna, in this report, is designed with PET film with size of $50{\times}15mm^2$. The RFID small-size Tag method for measurements is used by EPCglobal Static Test instrument in Anechoic Chamber, which is tested with dual Card, within the car and in wallet. It is found that Read Range is 3.8m from the EPCglobal Static Test, Maximum Read Range within the car from the field test results in 7.6m. Proposed Tag antenna is will be used in the parking control security system.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.8
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• pp.872-879
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• 2010

This paper describes the design for radiation pattern directivity of vehicle license plate RFID tag antenna to improve the readable range. Directivity pattern of the proposed passive antenna is decided by the meander line position and the bumper size attached to the tag antenna. In order to prove the verification of the calculated directivity pattern and readable range of the proposed antenna, the tag antenna has been fabricated and measured at the anechoic chamber. It is shown that the maximum directivity gain of the measured radiation pattern of active and passive tag antenna were observed 2.32 dBi and 3.1 dBi, respectively. The maximum readable range of passive tag antenna was measured about 8.5 m at ${\pm}45^{\circ}$ beam direction on the basis of the driving car direction($0^{\circ}$ of azimuth angle).

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.6
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• pp.1097-1108
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• 2019

In VLBI(Very Long Baseline Interferometry), the observed data created in many observatories which are far away from each other should be collected in correlation center for data analysis. Traditionally, observed data is moved by transportation such as car or airplane. But it is replaced with data transfer over the network rapidly as the advancement of information technology, and therefore, international cooperative research is also now more widely expanding. e-KVN(electronic Korean VLBI Network) has been upgraded two times so the network interface of KVN has been evolved to the highest specification of 100GbE. During this time period, the portion of network usage for VLBI observations and experiments in KVN has been increased exponentially. In this paper, we describe KVN VLBI system and network technology for the performance upgrade and advanced status monitoring between three radio astronomy observatories and Daejeon correlation center with KREONET(Korea Research Environment Open NETwork). Furthermore, future plan of e-KVN for the implementation of wide band VLBI observation will be also briefly discussed.

• Journal of Navigation and Port Research
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• v.32 no.10
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• pp.805-811
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• 2008

This paper presents a design of RFID(Radio Frequency Identification) tag antenna which is available for a vehicle's side mirror and directivity characteristics by mr body. The proposed Tag antenna is designed symmetrical structure to improve the broad bandwidth characteristic and the readable range. A proposed tag antenna($30\;mm{\times}24\;mm{\times}1\;mm$) has resonant frequency at 910 MHz and bandwidth is 780 MHz ($540\;MHz{\sim}1320\;MHz$). The chip impedance is the 16 - $j131\;{\Omega}$ and the complex conjugate impedance of commercial chip has been used for tag antenna design. In order to evaluate effects of tag antenna for side view mirror's permittivity as well as car body(conductor), radiation pattern characteristics and readable range have been calculated and measured. The optimized position for a vehicle's RFID system has been observed in the inside of a side mirror and the calculated results show good agreement with the measured results.

• Journal of the Korean Ceramic Society
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• v.44 no.11
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• pp.597-606
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• 2007

With the advent of ubiquitous age, the high quality dielectric materials have been required for the wireless communications available to the millimeterwave as well as microwave frequencies. The utilizable region for the frequency has been expanding to the millimeter-wave region because of the shortage of radio frequency (RF) resources. These high frequencies would be expected for ultra high speed LAN, ETS and car anti-collision system on the intelligent transport system (ITS) and so on. Silicates are good candidates for microwave/millimeterwave dielectrics, because of their low dielectric constant ${\epsilon}_r$ and high quality factor (High Q). Forsterite ($Mg_2SiO_4$) is one of the silicates with low ${\epsilon}_r$ of 6.8 and Q f of 240000 GHz. In this paper, we reviewed following three categories for synthesis of forsterite: (1) Synthesis of high Q forsterite (2) Adjust the temperature coefficient of resonant frequency $TC_f$ (3) Diffusion of $SiO_{4^-}$ and Mg-ions on the formation of forsterite.

• Journal of the Korean Professional Engineers Association
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• v.27 no.1
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• pp.5-12
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• 1994

In the high degree information society of the 21st century, along with the social activity becoming much more closer, our life style will also be very much changed. Recognition for obtaining various informations rapidly will be anticipated to enhance and the progress of a mobile communication system is greatly expected. This will enable the system to give and receive ″whenever, wherever, whomever, whatsever information.″ In our country, the car telephone and personal mobile communication services of radio calling etc. are diversified by the telecommunication system reformation and by the introduction of competive principle of the hereafter of 1988. Moreover, in accordance with the tariff, the number of subscrier is rapidly increasing. On the other hand, on the utility side of business, for the realization of a mobile communication which is abundant in functional nature, not only the hitherto voice but also non voice system of data communication is being introduced. The Ministry of Communications of Korea has been expediting the effective utilization of limited frequency band of qusai microwave band etc. as a concrete measures for an ever increasing demand. At the same time, to disseminate and promote a mobile communication most effectively, convenience, economic, and safety nature of the system, and in addition to these, international standardization is considered. For constitution of a new mobile communication, the Ministry has been promoting various policies designed for the digitalization of system, utility extention for home. personal level.