• Journal of information and communication convergence engineering
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• v.1 no.4
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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.

• Journal of the Korean Ceramic Society
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• v.33 no.5
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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.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.5
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• pp.3074-3078
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• 2014

We implemented a dual-band slot-coupled patch (SCP) antenna for the external access point (AP) of the wireless local area network (WLAN) band. The antennas consist of two radiators on three layers. The first radiator is a slotted bow tie antenna operating at the 2.4-2.483 GHz band. The second radiator is a patch antenna with parasitic elements operating at 4.095-5.845 GHz. The high gain and broad bandwidth is important element of wireless access. To enhance the bandwidth, a coupled feeding was used in the first radiator and a parasitic patch was used in the second radiator. We used a parasitic patch and chock to improve the directivity and isolation in both radiators. The porposed antenna was designed by EM simulation tool and measured. The S11 of the antenna was less than -11dB (VSWR 1.8:1) at operating frequency. The peak gain was more than 6 dBi in the first antenna and more than 8 dBi in the second antenna.

• Journal of the Mineralogical Society of Korea
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• v.12 no.1
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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.

• The Journal of the Acoustical Society of Korea
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• v.18 no.1
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• pp.25-31
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• 1999

This paper proposes a new wide-band beamforming algorithm which has Gaussian weighting at nested linear array for acoustic measurement. The beamforming is performed one-shot by using all sensors simultaneously, not octave-by-octave. Gaussian weighting of frequency-dependent function is applied to each sensor before time-delay compensation so as to control the frequency receiving band of each sensor. As the results of the simulations, it is confirmed that the proposed algorithm can form the one-shot beams having uniform directivity index and also it can be applied to the broad-band acoustic measurement.

• The Bulletin of The Korean Astronomical Society
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• v.43 no.1
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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.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2003.11a
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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.

• Journal of the Korean Chemical Society
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• v.17 no.4
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• pp.240-246
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• 1973

An analytic expression for the intensity of collision-induced light scattering obstained by introducing both short-range and long-range effects on the induced anisotropy. By taking argon as a specific example, it is shown that a narrow band at small frequency shifts is caused by long-range effects, while a broad band in the far wing of the spectrum is due to short-range effects. The overall intensity is a synthesis of these two bands and does not follow a simple exponential form. As temperature increases, the intensity at large frequency shifts increases makedly, while at small frequency shifts it changes little.

• Proceedings of the Korean Vacuum Society Conference
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• 2000.02a
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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.

• Journal of The Korean Astronomical Society
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• v.45 no.1
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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.