• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.1B
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• pp.175-182
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• 2000

(A hybrid-type wireless infrared data communication module was fabricated by using the light emitting andabsorption diodes with the one-chip of integrated digital circuits. The light emitting diode with the peak spectrum of 850 nm was made from compound semiconductor material of AIGaAs and shows high speed signal transmission with the delay time of 60 nsec for the light direction angle of 30". The Si PIN photodiode showsthe good absorption rate for the range of wavelength of 450-1050 nm and convex-type epoxy lens was utilized for the spectrum filtering on the visible-range spectrum below 750 nm, The data transmission speed is 115.2 kbps and the fabricated module satisfies on the IrDA 1.0 SIR standard requirements.)ments.)

• Journal of Institute of Control, Robotics and Systems
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• v.15 no.2
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• pp.148-154
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• 2009

In this paper, an embedded Kalman filter for a time-delayed controller is designed on an FPGA to estimate accelerations of the robot arm. When the time-delayed controller is used as a controller, the inertia estimation along with accelerations is needed to form the control law. Although the time-delayed controller is known to be robust to cancel out uncertainties in the nonlinear systems, performances are very much dependent upon estimating the acceleration term ${\ddot{q}}(t-{\lambda})$ along with inertia estimation ${\hat{D}}(t-{\lambda})$. Estimating accelerations using the finite difference method is quite simple, but the accuracy of estimation is poor specially when the robot moves slowly. To estimate accelerations more accurately, various filters such as the least square fit filter and the Kalman filter are introduced and implemented on an FPGA chip. Experimental studies of following the desired trajectory are conducted to show the performance of the controller. Performances of different filters are investigated experimentally and compared.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.177.1-177.1
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• 2012

국내기술로 개발된 고기동 위성이 해상도 70cm급 광학카메라를 탑재하고 태양동기궤도를 따라 지구 주위를 하루에 14바퀴이상 돌면서 임무를 수행한다. 높은 해상도의 영상을 얻기 위해 자세제어계에서는 고성능 별추적기와 자이로를 사용하는 정밀자세결정 로직과 반작용 휠을 사용하는 자세제어 로직을 운용한다. 자세제어계에서는, 발사환경 및 우주환경의 영향으로 인한 자이로의 오정렬, SF오차, 별추적기 상호간 오정렬에 대한 상대보정과 탑재컴퓨터에서 결정한 궤도 및 자세정보와 영상 기준점 정보를 이용하여 절대보정을 수행한다. 한편, 탑재 알고리즘에서는 강건한 자세결정로직을 운용하고 있고, 별추적기의 측정지연 보상, 처리 주기내의 평균 각속도 사용 등 실시간 운용으로 인한 제한으로 성능상의 제약이 있다. 따라서 정밀자세결정 지상 후처리 작업이 필요하며 이를 위해서 기 개발된 지상처리용 정밀자세결정 소프트웨어를 새로운 접속요구규격에 맞춰 업그레이드하였다. 지상처리 정밀자세결정을 위해서 탑재컴퓨터는 영상촬영 전후 일정기간 동안 별추적기 데이터, 자이로 데이터, 탑재컴퓨터에서 결정한 자세정보 등을 매 탑재컴퓨터 처리 주기로 저장하여 지상으로 전송한다. 전송된 자료를 이용하여 지상처리용 정밀자세결정 소프트웨어는 정밀궤도 정보와 결합하여 정밀자세결정을 수행한다. 고기동 위성의 경우 기동 후 정밀자세결정 수렴 속도 향상이 필요하며, 소프트웨어의 필터 파라미터를 조율하여 성능을 향상하였다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.4
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• pp.624-632
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• 1994

In this paper, we implement modulator of 155Mbps 64QAM RF MODEM, CCITT G. 707 SDH(Synchronous Digital Hierachy) 1 level, for DMR(DIgital Microwave Radio) STM-1 transmission, PSF(Pulse Shaping Filter) plays an important role to analyze modulator. We use 7 orders elliptic filter instead of Chebychev filter(roll-off facter a=0.5)in this paper. we obtain that roll-off factor, a is 0.33, group delay is less than 10nsec using this filter. Also we get -20dBm output level after passing the PSF, and 0dBm output level after passing the IF amplifier.

• KIPS Transactions on Software and Data Engineering
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• v.5 no.7
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• pp.333-338
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• 2016

This study is to estimate proximity without direct measurement of the weight of fresh ginseng. For this work, we developed a ginseng image acquiring instrument and obtained 126 ginseng images using the instrument. Image analysis and parameter extraction process was used C language based Labwindows/CVI development tools and open source library OpenCV. Estimation formula is made by weighing the sample with image analysis of fresh ginseng. We analyzed the correlation between the pixel number and the weight of ginseng using a linear regression approach. It was obtained a strong positive correlation coefficient of 0.9162 with a linearity value.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.11
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• pp.2039-2044
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• 2008

The problem of an efficient hardware implementation of multiple constant multiplication is frequently encountered in many digital signal processing applications such as FIR filter and linear transform (e.g., DCT and FFT). It is known that efficient solutions based on common subexpression elimination (CSE) algorithm can yield significant improvements with respect to the area and power consumption. In this paper, we present an efficient specialized adder design method for two common subexpressions ($10{\bar{1}}$, 101) in canonic signed digit (CSD) coefficients. By Synopsys simulations of a radix-24 FFT example, it is shown that the proposed method leads to about 21%, 11% and 12% reduction in the area, propagation delay time and power consumption compared with the conventional methods, respectively.

• Journal of the Korea Society of Computer and Information
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• v.18 no.11
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• pp.51-58
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• 2013

Camera performance of smartphone recently has been developed as much as the digital camera. Interest in applications As a result, many people take pictures and the number of people who are interested in application according to photos has been steadily increasing. However, there are only synthesis programs which are arraying some photos, overlapping multiple images. The model proposed in this paper, base on the emotion that is extracted from the facial expressions by combining the background and applying effects filters. And it can be also utilized in various fields more than any other synthesis programs.

• Proceedings of the Korea Information Processing Society Conference
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• 2008.11a
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• pp.1500-1503
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• 2008

H.264와 같은 고압축 비디오처리 기법의 등장으로 기존의 MPEG2와 같은 비디오 압축에서 H.264로의 비디오 트랜스코딩이 증가되고 있지만, 고압축 비디오 콘텐츠의 온라인과 오프라인에서 불법배포는 현재 문제가 되고 있다. 본 논문에서는 다이렉트쇼 환경 기반에서 고압축과 저작권 보호를 위한 비디오 트랜스 코딩과 워터마킹을 구현한다. 제안한 방법은 다이렉트쇼의 필터를 이용하여 MPG,WMV를 H.264로 비디오 트랜스코딩을 하고 이와 함께 비디오의 공간영역 특성을 이용하여 저작권 보호를 위한 강인한 워터마킹을 구현한다. 실험 결과 MPG,WMV를 H.264로 트랜스코딩에서 H.264의 QP(Quantization parameter)를 15로 하고 화면간 반복을 10프레임으로 하였을 경우 저작권 보호를 위하여 삽입된 워터마크는 평균 99% 검출됨을 확인하였고, 또한 트랜스코딩중 워터마크삽입에 따른 시간지연은 전체 트랜스코딩시간의 5.7%가 됨을 확인할 수 있었다. 제안한 방법은 저작권 삽입 기능가지는 트랜스코딩 소프트웨어를 필요로 하는 Digital TV방송, IPTV, DVD 사업에 사용 될 수 있을 것이다.

• The Journal of the Acoustical Society of Korea
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• v.28 no.1
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• pp.51-60
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• 2009

This paper presents a new method of designing room equalization filters using a warped common acoustical pole and zero (WCAPZ) modeling. The proposed method is capable of significantly reducing the order of the equalization filters without sacrificing the filter performance, especially, at low frequencies. Thus, the associated input-output delay is much smaller than the conventional block transform method while its computational complexity is comparable to it. The computational complexity also is still comparable to the conventional room equalization method, since the filter is implemented in the linear frequency domain after the pole-zero dewarping. Simulation results confirm that the use of the proposed algorithm significantly improves the room equalization over a range of low frequencies.

• Journal of the Korean Society for Nondestructive Testing
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• v.36 no.5
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• pp.370-376
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• 2016

Corrosion on the surface of a structure can generate cracks or cause walls to thin. This can lead to fracturing, which can eventually lead to fatalities and property loss. In an effort to prevent this, laser imaging technology has been used over the last ten years to detect thin-plate structure, or relatively thin piping. The most common laser imaging was used to develop a new technology for inspecting and imaging a desired area in order to scan various structures for thin-plate structure and thin piping. However, this method builds images by measuring waves reflected from defects, and subsequently has a considerable time delay of a few milliseconds at each scanning point. In addition, the complexity of the system is high, due to additional required components, such as laser-focusing parts. This paper proposes a laser imaging method with an increased scanning speed, based on excitation and the measurement of standing waves in structures. The wavenumber of standing waves changes at sections with a geometrical discontinuity, such as thickness. Therefore, it is possible to detect defects in a structure by generating standing waves with a single frequency and scanning the waves at each point by with the laser scanning system. The proposed technique is demonstrated on a wall-thinned plate with a linear thickness variation.