• Advances in aircraft and spacecraft science
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• v.3 no.3
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• pp.299-315
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• 2016

In this work, a strategy for passive vibration control of periodic structures is proposed which involves adding a periodic array of simple resonant devices for creating band gaps. It is shown that such band gaps can be generated at low frequencies as opposed to the well known Bragg scattering effects when the wavelengths have to meet the length of the elementary cell of a periodic structure. For computational purposes, the wave finite element (WFE) method is investigated, which provides a straightforward and fast numerical means for identifying band gaps through the analysis of dispersion curves. Also, the WFE method constitutes an efficient and fast numerical means for analyzing the impact of band gaps in the attenuation of the frequency response functions of periodic structures. In order to highlight the relevance of the proposed approach, numerical experiments are carried out on a 1D academic rod and a 3D aircraft fuselage-like structure.

• Proceedings of the IEEK Conference
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• 2004.06a
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• pp.293-296
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• 2004

This paper proposes an architecture of channel estimation for multi-band OFDM UWB systems presented to IEEE 802.15.3a by Multi-band OFDM alliance(MBOA). The multi-band OFDM (MB-OFDM) systems should have channel estimation for compensation of signal distortion by multi-band channel. The moving-averaging estimation algorithm and multi-band equalization architecture for MB-OFDM UWB systems proposed in this paper was verified by the simulation. Simulation results show that MB-OFDM system with the proposed architecture have the performance improved by about 3.4 dB compared to system with no channel estimation in 0.1$\pi$ phase-rotated channel.

• Journal of Internet Computing and Services
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• v.2 no.3
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• pp.27-36
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• 2001

Recently much attention has been paid for interference mitigation technique for the COMA system, since more capacity is available with same bandwidth. In this paper, we introduces a novel adaptive interference suppression techniques for the CDMA system with narrow band interference. The proposed interference rejection scheme employs the adaptive linear prediction techniques in the subband. In each subband, we can more easily find and cancel the narrow band signal as compared to the full band. Thus, the proposed interference rejection can be classified as another time-frequency techniques for the narrow band interference rejection(10). Computer simulation is conducted for the 3-G COMA system with IF band sampling techniques, yielding better interference rejection and bit error rate performance as compared to conventional one. Also, optimum filter is analyzed and from the analysis, it can be shown the subband prediction techniques can suppress narrow band interference more efficiently.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.7
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• pp.1282-1288
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• 2010

This paper proposes a novel microstrip patch antenna to make impedance matching possible by using slot/T-slot capacitive coupling between the patch and 50 $\Omega$ feed line on a ground plane. The single band/linear polarization patch antenna shows linear polarization at 2.4 GHz band. Under -10 dB return loss, the single band/linear polarization patch antenna obtains 50 MHz bandwidth at 2.37 GHz~2.42 GHz. The dual band/dual polarization microstrip patch antenna shows circular polarization at 2.4 GHz band and linear polarization at 3.1 GHz band. Under -10 dB return loss, The dual band/dual polarization microstrip patch antenna obtains 340 MHz bandwidth at 2.23~2.57 GHz and 375 MHz bandwidth at 2.95~3.325 GHz.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.7
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• pp.704-709
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• 2007

In this paper, a CPW band-pass filter with a rejection band is proposed for UWB(Ultra-Wideband) communication systems. The proposed filter has a band-pass characteristic of wide-band by inserting only a slot in $50{\Omega}$ transmission line. To obtain the band-rejection function at WLAN frequency band($5.15{\sim}5.725GHz$), the designed filter is combined with folded slot resonators on the ground plane of the CPW structure. The fabricated CPW band-pass filter shows a compact size of $15.35{\times}13.60mm$, a wide passband of 2.8 GHz to 9.8 GHz and the narrow stop-band of 5.15 GHz to 5.71 GHz for 3-dB bandwidth. Also, the measured group delay is less than 400 psec throughout the operation frequency band except the rejection band.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.294-294
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• 2015

하천과 해양에서 발생한 수질오염은 특성상 유속의 흐름에 따라 광범위하며 급속도로 퍼져나가기 때문에 이를 효율적으로 유지, 관리하기 위해서는 오염인자들에 대한 모니터링이 수행되어야 한다. 원격탐사 기술을 이용한 하천의 수질측정은 대규모지역으로 분포해있는 수질농도의 변화양상을 시 공간적으로 모니터링 하는 것이 가능하게 할 뿐 아니라, 사람이 접근하기 어려운 지역에는 직접취수를 하지 않음으로써 기존의 수질측정방법들에 비해 편의성을 높여 시간적, 경제적 측면에서 효율적이다. 이에 본 연구에서는 최근 수질오염이 심화되고 있는 낙동강유역을 대상으로 인공위성 이미지영상을 이용하여 수질인자들의 농도측정을 수행하였다. 연구를 위해 사용된 인공위성은 NASA와 USGS가 공동으로 운용중인 Landsat 8 인공위성이다. Landsat 8의 11개 band 중 band2(Blue), band3(Green), band4(Red), band5(Near Infrared)를 사용하여 실제로 측정된 지점자료와 인공위성자료간의 상관관계를 규명하였다. 사용된 인공위성자료는 지점자료 날짜를 포함하는 총 4개의 연구날짜(2013/10/27, 2013/11/12, 2014/04/14, 2014/05/16)에 해당하는 위성이미지영상이다. Pearson상관계수를 통한 밴드와 수질인자간의 상관 결과, 본 연구지역에서는 $0.85-0.88{\mu}m$(band5)의 파장영역에서 클로로필-a와 부유물질이 가장 민감하게 반응함을 알 수 있었다. 두 수질인자들은 band2, band3, band4에서도 비교적 높은 상관성을 보였으며, 이를 근거로 band combination, band ratio를 통해 클로로필-a와 부유물질의 회귀모델식을 유도하였다. 각각의 회귀모델식은 실제 측정된 데이터들과 비교 검증을 통해 4개의 연구기간 중 2013년 10월 27일, 2014년 5월 16일에 대해서 클로로필-a와 부유물질의 공간적인 분포양상을 시각적으로 도시화하였다.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.10 no.6
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• pp.84-90
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• 2011

In this paper, a dual-band pseudo-combline narrow bandpass filter is proposed. The proposed bandpass filter adopts the open resonant stubs and the proposed bandpass filter can be used for ITS(Intelligent Transport System) and X-band satellite systems application. The proposed bandpass filter has the insertion and return losses of 1.72 dB and 15.5 dB at the bandwidth of 3.6 % and center frequency of 5.8 GHz, respectively. Also, the second operating frequency band for insertion and return losses are 1.92 dB and 16.3 dB at the bandwidth of 3% and center frequency of 8.5 GHz, respectively.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2005.11a
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• pp.7-12
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• 2005

A compact microstrip band-selective filter for ultra-wideband (UWB) radio system is proposed. The filter combines the traditional short-circuited stub highpass filter and coupled resonator bandstop filter on both sides of the mitered 50-ohm microstrip line. To realize the pseudo-highpass filtering characteristic over UWB frequency band (3.1 GHz to 10.6 GHz), a distributed highpass filter scheme is adopted. Three coupled resonators are utilized to obtain the band stop function at the desired frequency band. By meandering the coupled resonators, there is 29% reduction in footprint compared to the traditional bandstop filter using L-shaped resonators. The measured results show that the filter has a wide passband of 146.7 % (2.1 GHz to 10.15 GHz) with low insertion loss and the stop band of 7.42 % (5.32 GHz to 5.73 GHz) for 3-dB bandwidth. The measured group delay is less than 0.7 ns within the passband except the rejection band.

• Journal of Environmental Health Sciences
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• v.32 no.6
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• pp.560-565
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• 2006

Extract of DNA for analysis of fragile X syndrome is usually performed by blood, the researches using hair root as specimen have been gradually spread. In this study, analyze fra X gene of the patients in mentally retarded children facilities was conducted using hair root DNA with molecular biologic test (PCR). The number of total subjects was 24, boys were 12, the average age was $17({\pm}3)$, and girls were 12, the average age was $18({\pm}2)$. In girls, normal size of band of 222 bp appeared in all lanes. Also, in all lanes except control in 517 bp, micro band appeared. Moreover, with appearance of band of 1198bp in lanes 2, 3, 4, 5, it is estimated that it is the band of full mutation whose CGG repeated sequences are more than 200. But it showed the peculiarity that it appeared with normal band in all the same lanes, thus it is not reasonable to judge it is the band of full mutation and further studies are needed. These results appeared in 50%, 6 of 12 mentally retarded girls. As the result of mentally retarded boys, normal band appeared in about 222 bp in control, however in experiment group, normal band did not appear. In 43%, 7 out of 12 boys, band did not either appeared in 1198bp, which showed different patterns from that of girls.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.10
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• pp.91-97
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• 1971

Fifteen samples of barley seed proteins representing winter 6-rowed, spring 6-rowed and spring 2-rowed group were separated by disc electrophoresis. Photographic, densitometric and diagrammatic representation were presented to make comparison possible. Eighteen to twenty one bands were detected in each gel. Electrophoretic spectrum of each variety was highly variety specific showing that the spectrum is the reflection of hereditary constituents of a organism. Related variety showed identical or nearly identical pectrum. All winter 6-rowed barley showed very faint B2 band, while spring 6-rowed and spring 2-rowed barley showed dense or less dense B2 band. All spring barley showed B3 band, while all winter barley showed B4 band.