• 한국전자파학회논문지
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• 제26권5호
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• pp.435-444
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• 2015

본 논문에서는 시분할 송신과 근거리에서 이동표적 탐지가 가능한 77 GHz 차량레이더용 가상배열 구조 설계에 대해 다루었다. 본 논문에서 기술된 가상배열 구조는 하드웨어의 복잡도, 무게 및 비용 등을 줄일 수 있는 반면, 시분할 송신에 의해 이동표적 탐지 시 수신신호의 위상왜곡으로 안테나 빔의 부엽이 높게 형성된다. 이를 위해 위상이 동일한 부배열 수신신호를 이용하여 안테나 빔의 부엽을 최소 10 dB 이상 억압시켰다. 또한, 근거리에서도 운용되어야 하는 차량레이더는 구면파 형태로 신호가 형성되어 평면파를 가정하는 빔 형성을 통해서는 빔 왜곡이 발생한다. 이를 위해 각 표적거리에 대해 관심 빔 조향 영역($-30^{\circ}{\sim}+30^{\circ}$)의 중심이 되는 정면 방향(${\phi}_{com}=0^{\circ}$)의 신호를 각 수신신호에 보정하여 안테나 빔의 왜곡된 주엽 형태를 회복시키고, 10~15 dB 정도 부엽 성능을 개선하였다.

• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.1530-1530
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• 2001

The objectives of this study were to develop models to predict quality parameters of Korean bee-honeys by visible and NIR spectroscopic technique. Two kinds of bee-honey fronl acacia and polyflower sources were tested in this study. The honeys were harvested in the spring of 2000 and stored in the storage facility at 20$^{\circ}C$ during experiments. Total of 394 samples of honey were analyzed. Reflectance spectra, moisture contents, ash, invert sugar, sucrose, F/G (fructose/glucose) ratio, HMF (hydroxymethyl furfural), and C12/C13 ratio of honeys were measured. The average values for the tested honeys were 19.9% of moisture contents, 0.12% of ash, 68.4% of invert sugar, 5.7% of sucrose, 1.27 of F/G(fructose/glucose) ratio, 14.4 mg/kg of HMF, and -19.1 of C12/C13 ratio. A spectrophotometer, equipped with a single-beam scanning monochromator (NIR Systems, Model 6500, USA) and a horizontal setup module, was used to collect reflectance data from honey. The reflectance spectra were measured in wavelength ranges of 400∼2,498 nm. with 2 nm of interval. Thirty-two repetitive scans were averaged, transformed to log(1/Reflectance), and then were stored in a microcomputer file, forming one spectrum per measurement. A sample cell and reflectance plate were made to hold honey samples constantly. Spectra of honey samples were divided into a calibration set and a validation set. The calibration set was used during model development, and the validation set was used to predict quality parameters from unknown spectra. The PLS(Partial Least Square) models were developed to predict the quality parameters of honeys. The first and the second derivatives of raw spectra were also used to develop the models with proper smoothing gap. The MSC (multiplicative scatter correction) and the SNV & Dtr.(standard normal variate and detranding) preprocessing were applied to all spectra to minimize sample-to-sample light scatter differences. The PLS models showed good relationships between predicted and measured quality parameters of honeys in the wavelength range of 1100∼2200 nm. However, the PLS analysis was not good enough to predict HMF of honeys.