• Journal of information and communication convergence engineering
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• 제1권4호
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• pp.189-193
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• 2003

A new algorithm is presented for adaptive notch filtering of narrow band or sine signals for embedded among broad band noise. The notch filter is implemented as a constrained infinite impulse response filter with a minimal number of parameters, Based on the recursive prediction error (RPE) method, the algorithm has the advantages of the fast convergence, accurate results and initial estimate of filter coefficient and its covariance is revealed. A convergence criterion is also developed. By using the information of the noise-to-signal power, the algorithm can self-adjust its initial filter coefficient estimate and its covariance to ensure convergence.

• 한국세라믹학회지
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• 제33권5호
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• pp.531-535
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• 1996

ZnGa2O4 and Mn-doped ZnGa2O4 were synthesized using the state reaction method to investigate their photoluminescence characteristics depending on Mn concentration. Under 254nm excitation, ZnGa2O4 exhibited a broad-band emission extending from 330 nm to 610 nm peaking at 450nm. On the other hand Mn-doped ZnGa2O4 showed a new strong narrow-band emission peaking at 504 nm and maximum intensity at the doping concentration of 0.006 mole Mn.

• 한국산학기술학회논문지
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• 제15권5호
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• pp.3074-3078
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• 2014

본 논문은 무선 근거리 네트워크(WLAN)대역의 Access Point(AP)용 이중대역 슬롯결합 패치(SCP) 안테나에 관한 것이다. 본 논문의 안테나는 세 개의 적층 구조로 구성되었고, 두 개의 방사체로 이루어져있다. 첫 번째 방사체는 2.4-2.483 GHz 대역에서 동작하는 슬롯형태의 나비넥타이(bow-tie) 안테나이다. 두 번째 방사체는 4.095-5.845 GHz에서 동작하는 기생 소자(parasitic element)들을 포함한 패치안테나이다. 높은 이득과 넓은 대역폭은 우수한 무선 접속의 중요한 요소이다. 대역폭을 넓히기 위해서 첫 번째 방사체에서 커플링 급전(coupling feed)이 사용되었고, 두 번째 방사체에 기생 패치(parasitic patch)를 사용하였다. 그리고, 지향성(directivity)과 격리도(isolation)를 향상시키기 위해 기생 패치(parasitic patch)와 초크(chock)를 고안하였다. EM 시뮬레이션을 통하여 분석하였고, 측정하여 결과를 확인하였다. 동작 주파수에서 -11dB 이하의 반사계수(S11)를 보여준다. 최대이득은 첫 번째 안테나에서 6 dBi이상, 두 번째 안테나에서 8 dBi이상이다.

• 한국광물학회지
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• 제12권1호
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• pp.23-31
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• 1999

The dehydroxylation of kaolinite was investigated in detail by means of energy-filtering transmission electron microscope with both orientations parallel and perpendicular to c. The dehydroxylation could be characterized by the broad background including (0.211) band (20~24$^{\circ}$ 2$\theta$) on X-ray diffraction and by the three halo rings (d-spacing : 3.28~4.40$\AA$ (near (02,11) band), 2.41~245$\AA$ (near (20,13) band), 1.16~1.23$\AA$ (near (0.8,44) band)), and (02,11) and (20,13) spots on electron diffraction. These indicate existence of a short-range order along the a and b axes. Interplanar spacing of (001) is reduced to about 6.86$\AA$ and the sharp additional intensity maximum of about 14.2$\AA$ reveals that metakaolinite has a modulated structure along c axis. It is proposed that the modulated structure is attributed to the domains consisting of more than two-layers due to the changes of positions of the vacant octahedral sites in successive layers.

• 한국음향학회지
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• 제18권1호
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• pp.25-31
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• 1999

본 연구에서는 음향측정 목적의 선형배열에 가우시안 가중치를 적용시킨 광대역 단일 빔형성 알고리듬을 제안한다. 제안 알고리듬은 배열 내의 모든 센서를 동시에 사용하여 1회에 광대역 수신 빔을 형성시킨다. 여기서 주파수 종속 함수의 가우시안 가중치는 각 센서의 수신 주파수 범위를 제어하도록 시간지연 보상 전에 적용된다. 시뮬레이션 결과, 제안 알고리듬에 의해 형성된 광대역 단일빔의 지향지수 및 빔패턴 특성이 광대역 음향신호 측정에 가용함을 확인하였다.

• 천문학회보
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• 제43권1호
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• pp.49.2-49.2
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• 2018

Flux calibration for narrow band photometric data gives us an opportunity to get a line flux of extended targets. We developed flux calibration processes for narrow band photometry using broad band filters as a continuum indicator. We derived parameters for color correction and zero point correction including color terms. Applying our method, we successfully subtracted continuum emissions and calibrated the emission lines from an FU Ori type object, V960 Mon.

• 한국전자파학회:학술대회논문집
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• 한국전자파학회 2003년도 종합학술발표회 논문집 Vol.13 No.1
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• pp.437-441
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• 2003

The major drawback of the classical microstrip patch antennas Is their narrow band characteristic from 1% to 5%. In this paper, to improve this drawback, we designed the antenna with stacked structure having one drive patch connected with feed line and four identical radiation patches. Resonance is achieved by adjust ing coupling area between one drive patch and four identical radiation patches and changing the size of drive patch or radial ion patches. Used substrate is FR4(${\epsilon}_r$=4.6 and t=1.6mm) and designed center frequency is 2.45GHz. The designed antenna has a wide bandwidth of 380Mhz form 2.333GHz to 2.713GHz(about 15.5%) including ISM band from 2.4GHz to 2.4835GHz.

• 대한화학회지
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• 제17권4호
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• pp.240-246
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• 1973

분자 혹은 원자간의 충돌에 의한 light scattering의 강도를 계산하는 이론식을 유도하였다. Argon을 예로하여 적은 진동수 shift에 나타나는 좁은 분광 band는 원자간의 장거리 효과가 이방성에 미치는 영향에 의한 것이고 큰 진동수 shift에서의 넓은 분광 band는 단거리 효과에 의한 것임을 지적하였다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2000년도 제18회 학술발표회 논문개요집
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• pp.166-166
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• 2000

We studied electronic structure of magnetic semiconductors EuO, EuS, and EuTe. The photoemission spectra show localized Eu 4f states and broad anion p bands. As the size of anion increases from oxygen to tellurium, anion p band width increases and eventually overlaps Eu 4f states. Hence in EuO and EuS, Eu 4f states are the highest occupied stated lying above anion p band, while Te 5p band spreads widely over Eu 4f states to become valence band maximum in EuTe. It was also observed that Eu 4f states have width of 0.7eV and dispersion of 0.2eV in EuS by angle resolved photoemission spectroscopy. The width of the 4f spectra mainly originates from atomic multiplets, but the much larger dispersion than that of Eu metal is due to p-f mixing.

• 천문학회지
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• 제45권1호
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• pp.7-17
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• 2012

Y-band is a broad passband that is centered at ~1 ${\mu}m$. It is becoming a new, popular window for extragalactic study especially for observations of red objects thanks to recent CCD technology developments. In order to better understand the general characteristics of objects in Y-band, and to investigate the promise of Y-band observations with small telescopes, we carried out imaging observations of several extragalactic fields, brown dwarfs, and high redshift quasars with Y-band filter at the Mt. Lemmon Optical Astronomy Observatory and the Maidanak observatory. From our observations, we constrain the bright end of the galaxy and the stellar number counts in Y-band. We also test the usefulness of high redshift quasar (z >6) selection via i - z - Y color-color diagram, to demonstrate that the i - z - Y color-color diagram is effective for the selection of high redshift quasars even with a conventional optical CCD camera installed at a 1-m class telescope.