• Journal of the Microelectronics and Packaging Society
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• v.2 no.2
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• pp.19-30
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• 1995

일반적으로 마이크로 웨이브 영역에 사용되는 마이크로스트립 전송로는 후막 전도 선을 이용하여 RF 모듈을 구현할수 있으나 선폭의 고해상도가 전체 특성에 큰 영향을 미치 므로 고정도의 박막을 이용한 RF 모듈이 많이 개발되고 있다. 따라서 본 논고에서는 박막 제조기술을 이용하여 마이크로 웨이브 하이브리드의 한 종류인 WILKINSON 전력 분배기 를 개발하였고 공정 변수를 최적화함으로써 고특성 고신회성의 전력 분배기를 구현할 수 있 었다. 먼저 전도선의 두께의 영향을 고찰하였으며 제조 공정에 있어 GROUND 방법 /HOUSING 형상을 개선함으로써 용이하게 전력 분배기를 제조하였다. 마지막으로 MIL 규 격에 따른 전력분배기의 신뢰성 시험 항목을 제시하였고 이에 따라 정격 전력을 계산, 측정 하였다.

• Broadcasting and Media Magazine
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• v.25 no.3
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• pp.8-15
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• 2020

우리나라에서 방송과 통신을 통틀어 아직도 아날로그 방식에 머물러 있는 유일한 매체는 지상파 라디오방송이다. 20년 전에 시작한 디지털 라디오 논의는 수년째 중단된 상태다. 유럽과 미국에서는 디지털 라디오 방송뿐 아니라 하이브리드 라디오까지 출현하여 디지털 부가정보가 오간다. 우리나라는 여전히 아날로그다. 디지털 전환은 요원하지만 음성, 음향에 연계하는 정보 서비스 수요는 늘어나고 있다. 아날로그 라디오에서 당장 구현 가능한 디지털 데이터 서비스 방안을 찾아본다.

• The Optical Journal
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• s.128
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• pp.54-61
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• 2010

아시아 최고의 사진영상분야 전시회로 손꼽히는 '2010 서울국제사진영상기자재전' (이하 P&I 2010)이 지난 4월 29일부터 5월 2일까지 나흘간 서울 코엑스 본관 1층 A홀에서 성황리에 펼쳐졌다. 올해로 19회째를 맞이한 이 전시회에는 삼성을 비롯한 캐논, 니콘, 소니, 올림푸스, 파나소닉 등 디지털 카메라 제조사와 관련 주변기기 및 액세서리 업체 등 총 112개 업체가 참가하여 527부스 규모로 전년대비 28%나 증가한 역대 최대 규모로 치러졌다. 특히 올해 전시회의 화두는 최첨단 디지털이미징 기술을 바탕으로 한 '하이브리드 디지털 카메라'로 사진인들로부터 뜨거운 관심을 받았다. 또한 새로운 기능의 출력장비를 비롯하여 다양한 사진 소프트웨어, 사진 액세서리, 사진 스튜디오 관련 장비 등을 한 자리에서 봄으로써 최신 기술동항의 흐름을 파악할 수 있는 좋은 기회가 되었다. 올해 전시기간동안 6만7052명의 참관객들이 발걸음을 해 사진영상분야에 대한 소비자들의 뜨거운 관심도를 확인할 수 있었다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.7
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• pp.737-743
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• 2011

In this paper, we designed and implemented a Monopole+IFA(Inverted F Antenna) hybrid antenna using the coupled feeding structure for the all band mobile phone. Studied antenna has wide band characteristics by the simultaneous operation both monopole and IFA under the coupled feeding structure. An antenna has designed PCB embedded type without antenna carrier component for the low in cost. Implemented antenna has within 2.5:1 for VSWR under LTE/CDMA/GSM900/DCS/USPCS/WCDMA/WiBro/WiFi in all band for the mobile services Measured average gains and efficiencies were -3.98~-0.09 dBi and 40.03~97.99 % for the LTE, CDMA, GSM900 band, and -3.90~-1.01 dBi and 40.70~79.31 % for the DCS, USPCS, WCDMA, WiBro, WiFi band. It's shown that studied antenna can be applied to all band mobile phone antenna including LTE.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.8 no.4
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• pp.342-353
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• 1997

This paper presents an analytical evaluation of a hybrid direct-sequence/slow frequencyhopped code division multiple-access (DS/SFH-CDMA) system employing noncoherent M-ary frequency shift keying(MFSK) modulation in a multiple Nakagami fading (m) environment. Multipath interference (MPI) and multi-access interference (MAI) is taken into account and the spectral efficiency is calculated for uncoded as well as channel coding systems. Predetection multipath maximal ratio combining (MRC) diversity in conjunction with interleaved channel coding (Hamming(7,4) code, BCH(15, 7) code and RS (7, 4), (15, 9)) code ) is employed for improving the bit error rate (BER) performance. The BER of noncoherent hybrid system is obtained using a Gaussian interference approximation.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.3
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• pp.227-234
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• 2014

Fuel consumption rates of electric vehicles strongly depend on their battery performance. Because the battery performance is sensitive to the operating temperature, temperature management of the battery ensures its performance and durability. In particular, the temperature distribution among modules in the battery pack affects the cooling characteristics. This study focuses on the thermal modeling of a battery pack to observe the temperature distribution among the modules. The battery model is a prismatic model of 10 NiMH battery modules. The thermal model of the battery consists of heat generation, convective heat transfer through the channel and conduction heat transfer among modules. The heat generation is calculated by the electric resistance heat during the charge/discharge state. The model is used to determine a strategy for proper thermal management in Electric vehicles.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.11
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• pp.1279-1290
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• 2007

In this paper, a cylindrical hybrid antenna which is spatially fed by an off-set linear feed array is described to form complex beam patterns. The linear feed array consists of twelve micro-strip patch elements and forms a flat-topped beam pattern with a beam-width of $90^{\circ}$ in the horizontal plane. The vertical curve on the cylindrical reflector with the linear feed array is shaped in order to form a cosecant beam pattern within the range of $-5^{\circ}$ to $-25^{\circ}$ in the vertical plane. To form complex beam patterns, the hybrid antenna with cylindrical reflector aperture of $140{\times}50\;cm$ was designed and fabricated to be operated within the IMT 2000 service band, and also electrical performances of the antenna were measured and analyzed.

• The Journal of the Korea Contents Association
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• v.14 no.6
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• pp.453-465
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• 2014

Although fairly descent amount of research outcomes has been generated on problem-based learning(PBL) with regard to science and medical subjects, relatively less outcome has been generated on social science and management subjects. Therefore this study attempts to exam effect of problem-based learning in food service entrepreneurship subject on improving problem solving skills. After literature review, for constructing for this research frame, each class schedules were formed by hybrid-PEL and traditional lecture style respectively then problems, solution, and evaluation process were generated for hybrid-PBL. Through the result, there was hardly any differences occurred before and after traditional lecture approach on students' problem solving skills. There was, however, certain differences appeared on students' skills after hybrid-PBL approach. Through the study, hybrid-PBL learning can be an effective teaching method in social science and management subject for improving students' problem solving skill.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.12 no.3
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• pp.78-86
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• 2013

A hybrid MIMO(Multi Input Multi Output) antenna which is operating both a monopole and a IFA(Inverted F Antenna) is designed. It's applied Vlade(Vertical lade) technique to reduce antenna space, and a diagonally fed MIMO antenna is designed on the bare board for the data communication. Return losses due to variables of antenna length are simulated for the design. Antenna for the hexa-frequency band of LTE700, CDMA, GSM, DCS, PCS and WCDMA is designed and implemented. This antenna is satisfied 3:1 VSWR over the whole design band by the measurement of return loss. And average gains and efficiencies were -3.67 ~ -2.53dBi and 42.06 ~ 55.84% for LTE700/CDMA/GSM frequency band, -3.27 ~ -1.21dBi and 47.08 ~ 75.6% for DCS/PCS/WCDMA frequency band. The isolation between 2 antenna that is one of important factors for the MIMO system was measured good performance as -8.14 ~ -25.77dB over the whole service band.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.29 no.9
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• pp.735-738
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• 2018

The accuracy of extracting the azimuth angle of a target is significantly affected by the error in the mono-pulse ratio of the air-borne antenna hybrid mono-pulse Radar system. This error is strongly induced by the phase imbalance between the channels of the system. In this paper, a method is proposed for effectively calibrating the phase imbalance caused by physical differences between the RF channels from the antenna to the $180^{\circ}$ hybrid. Through a flight test, it was confirmed that the accuracy of the azimuth angle of the target is improved by using the proposed method.