• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.12
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• pp.1148-1154
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• 2011

In this paper, the radiation properties of a Ka-band Von Karman radome are analyzed by using an IPO(Iterative PO) scheme. Since the operating frequency is very high, and the size of the considered radome is large, a numerical method cannot be directly applied to calculate the properties of the radome such as transmission loss, radome pattern, boresight error, etc. Hence, in this paper, an IPO scheme is used, which can efficiently consider the multiple interaction inside the radome. Also, the IPO scheme is based on the PO scheme, which is efficient and fast in a numerical point of view. The proposed scheme is verified based on Ku-band measurement data, and its feasibility for applicability to a higher frequency simulation is addressed through a simulation at the Ka-band.

• Applied Biological Chemistry
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• v.20 no.2
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• pp.182-187
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• 1977

This investigation was to determine the changes in the trypsin inhibitor activity(TIA) and electrophoresis patterns of the soybean cotyledon and axis during germination. The TIA of the cotyledon decreased slightly and that of the axis decreased rapidly to 50% activivity after 7 day germination. At the 2nd, 3rd and 4th day's germination the TIA of the defatted dry axis was higher than that of cotyledon. However, the TIA of the fresh cotyledon was lower than that of the axis, due to its higher moisture content. Results from the electrophoretic studies showed that band 1 (polymer, 15S etc.), 2(11S), and 3(7S) whichare the major reserve proteins of soybean were decreased consid erably in cotyledon and axis and the fragments with Rm values between 0.5 and 1.0 were increased and band 5 showed up during germination. The band 4 of the cotyledon and band 6 of axis were not changed during germination. Generally speaking, the TIA and thereserve protein decreased as germination proceed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.4
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• pp.1982-1987
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• 2013

In this paper, a design method to obtain a band rejection characteristic in the 2.4-2.484 GHz WLAN band is studied for a series-fed dipole pair (SDP) antenna operating in the band of 1.7-2.7 GHz for mobile communication base station applications. The band rejection characteristic is achieved by inserting U-shaped slots on the coplanar strip line connecting the two dipole elements of the SDP antenna. The effects of the location and dimension of the slots on the rejection band characteristics are examined. The optimized SDP antenna with WLAN band rejection is fabricated on an FR4 substrate and the experimental results show that the antenna has a desired band rejection performance with a frequency band of 1.65-2.78 GHz (51.0%) for a VSWR < 2, and a rejection band of 2.39-2.54 GHz.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2005.11a
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• pp.259-264
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• 2005

In this paper, a novel compact microstrip-fed antenna with band-rejection characteristic for wideband applications is proposed. By cutting an L-shaped notch on the radiation patch, the wideband property for the proposed antenna is achieved. In addition, a C-shaped slot is introduced to obtain the band rejection operation of the antenna. The antenna, with very small size of $15.5\times21 mm^2$ including the ground plane, operates over 3.08 to 10.97 GHz and has the rejection band of 5.03 to 5.91 GHz for $S_{11}$ < -10 dB.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2001.11a
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• pp.165-168
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• 2001

This Paper presents the design method and performance characteristics of a dual band balun. The design method for dual balun is based on the lumped element eqiuvalent circuit of quater-wave transformaer. By employing the proposed configuration and the derived formulas, dual band balun are designed and simulated and manufactured. The proposed design method and equivalent circuit can make it easy to adapt to designing of ceramic multi-layer chip type dual band balun. The dual band will find applications in wireless communication circuits.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.197-198
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• 2008

이 논문에서는 다양한 SiNx의 band gap을 이용하여 MIS 구조의 메모리 소자를 제작하고 이를 분석하였다. SiNx 박막은 증착 가스비에 따라 다양한 band gap을 가지게 된다. 본 실험에서는 $SiH_4$ 가스와 $NH_3$ 가스를 사용하여 SiNx 박막을 증착하였다. n-type 단결정 실리콘 기판위에 다양한 가스비에 따라 단일 SiNx 박막을 증착 및 분석하였고, 이를 이용하여 NNN 구조의 MIS 소자를 제작하였다. 제작된 소자는 4.6 V의 hysteresis roof 폭과 1000 초 후에 84.8 %의 retention 값을 갖는 우수한 메모리 특성을 보였다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.2 s.93
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• pp.199-203
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• 2005

In this paper, a novel compact and frequency band-notch antenna for Ultra-Wideband(UWB) applications is proposed. The designed antenna not only shows good impedance bandwidth for ultra-wideband but has band notch characteristic for the frequency band of $5.15\~5.825\;GHz$ limited by IEEE 802.1la and HIPERLAN/2. To achieve both properties of wide band and band notch, the techniques of a concaved ground plane and inserted U-shaped thin slot into planar radiator are used respectively. A manufactured antenna satisfied VSWR<2 for the frequency band of $2.95\~11.7\GHz$ except the limited band of $4.92\~5.866\;GHz$.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.29 no.4
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• pp.320-323
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• 2018

Herein, an ultrawideband spinning direction finding (DF) antenna was designed and fabricated for airborne applications. The proposed antenna is designed by dividing the low-band (UHF - L band) and high-band (S - Ka band) antennas to cover the ultrawideband frequency range (UHF - Ka band). For the high-band antenna, an LPDA antenna fed offset-parabolic-reflector antenna is applied. In the low-band antenna, two LPDA antenna elements are arrayed in front of the reflector of the high-band antenna without increasing to the full antenna size. The low- and high-band gains of the fabricated antenna were measured as 8.76 dBi and 24.55 dBi on average, respectively. The antenna was fabricated with the dimensions of 437 mm in diameter and 358 mm in height. Consequently, we confirmed that the designed antenna is appropriate for the spinning DF antenna in terms of the affordable size for installing on an airplane, as well as the high gain and narrow beamwidth.

• Journal of Korea Multimedia Society
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• v.17 no.11
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• pp.1270-1278
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• 2014

The modern infrared (IR) imaging systems use mainly one or more wavelength bands among short wavelength IR (SWIR), middle wavelength IR (MWIR), and long wavelength IR (LWIR) bands. In the process of IR image synthesis and modeling, IR image wavelength-band conversion which transforms arbitrary band image to other band one is required. The wavelength-band conversion procedure includes a temperature estimation process of an object surface. However, in this procedure, an approximated Planck's radiation equation causes errors in estimated temperature. In this paper, we propose an estimation temperature error attenuation method in IR image band conversion procedure. The estimated temperature is corrected with a slope information of radiance according to it. The corrected temperature is used for generation of the other band IR image. The verification of proposed method is demonstrated through the simulation.

• Journal of the Korean Ceramic Society
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• v.56 no.3
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• pp.325-330
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• 2019

Band convergence is known to be effective in improving thermoelectric performance by increasing the Seebeck coefficient without significantly reducing electrical conductivity. Decoupling of the Seebeck coefficient and electrical conductivity in converged bands is the key requirement. Yet, the degree of decoupling depends on the band parameters of the converging bands. Herein, we report theoretical transport properties of two valence bands as their energy difference changes from 0.25 eV to 0 eV. In order to demonstrate the effect of band parameters in transport, we first conducted calculations for the case where the two bands have the same parameters. Then, we conducted the same calculation by doubling the density-of-states effective mass of one valence band. Given that there are two bands, each band's effective mass was doubled one at a time while the other band's effective mass remained constant. We found that the decoupling was strongest when the bands participating in convergence had the same band parameters.