• KSII Transactions on Internet and Information Systems (TIIS)
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• 제5권9호
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• pp.1632-1652
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• 2011

This paper considers the object tracking problem in three dimensional (3-D) space when the azimuth and elevation of the object are available from the passive acoustic sensor. The particle filtering technique can be directly applied to estimate the 3-D object location, but we propose to decompose the 3-D particle filter into the three planes' particle filters, which are individually designed for the 2-D bearings-only tracking problems. 2-D bearing information is derived from the azimuth and elevation of the object to be used for the 2-D particle filter. Two estimates of three planes' particle filters are selected based on the characterization of the acoustic sensor operation in a noisy environment. The Cramer-Rao Lower Bound of the proposed 2-D particle filter-based algorithm is derived and compared against the algorithm that is based on the direct 3-D particle filter.

• 대한전자공학회논문지TC
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• 제46권5호
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• pp.162-167
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• 2009

본 논문에서는 대역통과 여파기와 저역통과 여파기를 하나의 구조로 합성하여 크기 증가 없이 초광대역 특성을 가지는 여파기를 설계 및 구현하였다. 제안한 구조는 그 구조가 간단하다. 그리고 저역 통과 특성을 얻기 위하여 이미 잘 알려진 DGS(Defected Ground Structure) 구조를 이용하였다. 기존의 대역통과 여파기와 저역통과 여파기를 직접 연결하였을 때 보다 크기를 줄일 수 있었다. 측정결과 통과대역은 $2.1GHz{\sim}10.56GHz$이고 삽입손실은 최대 0.5dB, 반사손실은 최소 20dB, 군 지연은 $0.13ns{\sim}0.35ns$ 까지 최대 변화폭 0.23ns의 변화를 보인다.

• Journal of Electrical Engineering and Technology
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• 제8권1호
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• pp.168-175
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• 2013

This paper presents compact dual-band WLAN filter and filter module. They were developed by embedding all of the passive lumped elements into a LTCC substrate. In order to reduce the size/volume of the filter and avoid EM parasitic couplings between the passive elements, the proposed filter was designed using a 3rd order Chebyshev circuit topology and J-inverter transformation technology. The 3rd order Chebyshev bandpass filter was firstly designed for the band-selection of the 802.11b and was then transformed using finite transmission zeros technologies. Finally, the dual-band filter was realized by adding two notch resonators to the 802.11b filter circuit for the band-selection of the 802.11a/g. The maximum insertion losses in the lower and higher passbands were better than 2.0 and 1.3 dB with minimum return losses of 15 and 14 dB, respectively. Furthermore, the filter was integrated with a diplexer to clearly split the signals between 2 and 5 GHz. The maximum insertion and minimum return losses of the fabricated module were 2.2 and 14 dB at 2.4 - 2.5 GHz, and 1.6 and 19 dB at 5.15 - 5.85 GHz, respectively. The overall volume of the fabricated filter was $2.7{\times}2.3{\times}0.59mm^3$.

• 한국인터넷방송통신학회논문지
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• 제14권6호
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• pp.169-173
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• 2014

다양한 서비스에 대한 사용자의 욕구를 충족시키고, 주파수를 효율적으로 사용하기 위해서 여러 통신방식을 하나의 플랫폼에서 제공할 필요가 있다. 다양한 통신방식을 수용하는 광대역 무선통신시스템을 구현하기 위해서는 통신시스템 전단부에 반드시 대역가변필터를 사용해야 한다. 본 논문에는 캐비티 공진기의 구조를 갖는 800 MHz ~ 1600 MHz 범위의 대역가변필터의 구현 가능성을 확인하기 위해서 동일한 동작주파수 범위를 갖는 필터뱅크를 설계 및 제작하였다. 필터뱅크는 원하는 동작주파수 범위에서 5개의 대역통과필터로 제작하였고, 제작한 필터뱅크의 삽입손실은 최대 0.326 dB, 대역폭은 37 MHz ~ 84 MHz 그리고 감쇠특성은 대역 가장자리 ${\pm}60MHz$ 지점에서 최소 19.974 dB와 최대 37.812 dB로 측정되었다.

• Journal of Electrical Engineering and Technology
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• 제11권2호
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• pp.463-469
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• 2016

In this paper, the use of a dual composite right/left-handed coplanar waveguide (CPW) transmission line is proposed for the design of a band rejection filter. The notch property of the filter is achieved by combining the convex signal line with the shorted concave meander line, and the equivalent circuit model is extracted from the geometry of the unit cell for organizing the band rejection property. Then the equivalent parameters of the unit cell are analyzed to identify those behaviors. And the dispersion characteristics and energy distributions are simulated. In the end, the band rejection filter is manufactured by cascading two proposed unit cells. We show that the measurement result for the resonant frequency demonstrates good agreement with the simulation result and the band rejection filter provides a rejection performance of 17.5 dB at the stopband frequency ranging from 869 MHz to 894 MHz.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1998년도 추계종합학술대회 논문집
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• pp.31-34
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• 1998

CDMA base station SAW filter has been designed and fabricated successfully. Through the computer simulation, SAW filter is designed to have center frequency of 69.99MHz, ripples lower than 0.7dB and rejection level lower than 50dB. To obtain low noise band pass SAW filter, Input electrode has a apodization type and output electrode has a withdrawal type. For the fabrication of the SAW filter, Al thin film is deposited to the quartz substrates. The fabricated SAW filter has center frequency of 70.5MHz, ripples of 1dB and rejection level of 45dB.

• 대한음성학회지:말소리
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• 제67호
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• pp.195-216
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• 2008

This paper addresses the problem of single-channel speech separation to extract the speech signal uttered by the speaker of interest from a mixture of speech signals. We propose to apply time-frequency smoothing to the existing statistical single-channel speech separation algorithms: The soft mask and the minimum-mean-square-error (MMSE) algorithms. In the proposed method, we use the two smoothing later. One is the uniform mask filter whose filter length is uniform at the time-Sequency domain, and the other is the met-scale filter whose filter length is met-scaled at the time domain. In our speech separation experiments, the uniform mask filter improves speaker-to-interference ratio (SIR) by 2.1dB and 1dB for the soft mask algorithm and the MMSE algorithm, respectively, whereas the mel-scale filter achieves 1.1dB and 0.8dB for the same algorithms.

• 한국전자파학회:학술대회논문집
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• 한국전자파학회 2003년도 종합학술발표회 논문집 Vol.13 No.1
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• pp.188-192
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• 2003

A multilayer two-stage LC bandpass filter using low-temperature cofired-ceramic (LTCC) is proposed in this paper. The proposed bandpass filter is composed of two ceramic substrates with different dielectric constant instead of single ceramic material from top to bottom layer. The bandpass filter size is $2.0 mm{\times}1.2 mm{\times}0.8 mm$. Positioning of attenuation polefrequency, importance parameter for a performance of filter, is discussed using even-odd mode analysis by tuned capacitance of coupling capacitor and those results is implemented to LTCC filter circuit. Measured filter performances show that the insertion losses are -4.5dB, -4.1dB at 2.45GHz, 2.75GHz and the return losses are -8.5dB, 8.7dB.

• 대한전기학회논문지:시스템및제어부문D
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• 제55권9호
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• pp.429-434
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• 2006

In this paper, detection based - adaptive windowed nonlinear filter(DB-AWNF) is proposed for removing salt-pepper noise in infrared image. This filter is composed of impulse detector and window-size-variable median filters. Impulse detector checks whether current pixel is impulse or not using range function and nonlinear location estimator. If impulse is detected, current pixel is filtered according to four kinds of local masks by use of median filter. If not, current pixel is delivered to output like identity filter. In Qualitative view, the proposed could have removed heavy corrupted noise up to 30% and reserved the details of image. In quantitative view, PSNR was measured. The proposed could have about 12-31[dB] more improved performance than those of median $(3{\times}3)$ filter and 13-29[dB] more improved performance than those of median $(5{\times}5)$ filter.

• Journal of Information Display
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• 제11권1호
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• pp.24-27
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• 2010

A novel stereo 3D LCD for passive interference filter glasses is presented. A demonstrator based on a standard 120Hz LCD was set up. Stereoscopic image separation was realized in a time-sequential mode using a LED-based scanning backlight with two complementary spectra. A stereo brightness of 3 cd/$m^2$ and a channel separation of 30:1 were achieved.