• Proceedings of the IEEK Conference
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• 1998.06a
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• pp.157-160
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• 1998

The analysis of a coaxial cable with periodic slots as a leaky-wave antenna is considered. The mode matching method and method of moments with Galerkin testing procedure is then used to obtain the determinantal equation for the unknown leaky-wave propagating constant. Both technigues allow the fields to be obtained in any region, and the radiation characteristics of the structure. By resorting to a suitable numerical techniques, it is possible to calculate the leaky-wave propagating constants and the radiation patterns. Numerical results demonstrate the validity of the technique.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2005.04a
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• pp.378-381
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• 2005

This paper presents a new linear-matrix-inequality-based intelligent digital redesign (LMI-based IDR) technique to match the states of the analog and the digital T-S fuzzy control systems at the intersampling instants as well as the sampling ones. The main features of the proposed technique are: 1) the fuzzy-model-based periodic control is employed, and the control input is changed n times during one sampling period; 2) The proposed IDR technique is based on the approximately discretized version of the T-S fuzzy system, but its discretization error vanishes as n approaches the infinity. 3) some sufficient conditions involved in the state matching and the stability of the closed-loop discrete-time system can be formulated in the LMIs format.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.12 no.3
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• pp.451-461
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• 2001

We present a simple design method of velocity-matched traveling-wave (TW) electrode with periodic capacitive loads. Once matching impedance and optical phase velocity are defined, the width and separation of coplanarstrip (CPS) and the magnitude and period of capacitive load are determined analytically. Calculation results of velocity-matched TW electrodes on GaAs substrates show bandwidths of more than 100 GHz.

• Journal of Korea Multimedia Society
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• v.17 no.2
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• pp.132-142
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• 2014

Stereo camera is drawing attention as an essential sensor for future intelligence robot system since it has the advantage of acquiring not only distance but also other additive information for an object. However, it cannot match correlated point on target image for low textured region or periodic patterned region such as wall of building or room. In this paper, we propose a stereo matching technique that increase the matching performance by fusing belief propagation stereo matching algorithm and local distance measurements of 2D-laser range finder in order to overcome this kind of limitation. The proposed technique adds laser measurements by referring quad-tree based segment information on to the local-evidence of belief propagation stereo matching algorithm, and calculates compatibility function by reflecting over-segmented information. Experimental results of the proposed method using simulation and real test images show that the distance information for some low textured region can be acquired and the discontinuity of depth information is preserved by using segmentation information.

• Journal of Korea Society of Industrial Information Systems
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• v.6 no.3
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• pp.29-34
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• 2001

In this paper, a new associative memory system for analog time-sequential data processing is proposed. This system effectively associate time-sequential data using not only matching with present data but also matching with past data. Furthermore in order to improve error correction ability, weight varying in time domain is introduced in this system. The network is simulated with several periodic time-sequential input patterns including noise. The results show that the proposed system has ability to correct input errors. We expect that the proposed system may be applied for a real time processing of analog time-sequential information.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.9
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• pp.116-125
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• 2008

Inkjet printing technology with a drop-on-demand (DOD) inkget head technology has been recognized as one of versatile and low cost manufacturing tools in the electronics industry. Concerned with control of driving signal, however, general strategy to optimize jetting stability has not been understood well, because of the inherent complex multi-physics nature in inkjet phenomena. Motivated by this, present study investigates the effect of driving waveforms of piezoelectric head on jetting characteristics of DOD inkjet system focused on jetting stability with phase matching of pressure waves in the print head. The results show that velocities and volumes of the ink jetted droplets were linear relations with the driving signal's maximum voltage, while periodic behaviors are observed with the driving signal's pulse widths.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1444-1449
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• 2007

Inkjet printing technology with a drop-on-demand (DOD) inkjet head technology has been recognized as one of versatile and low cost manufacturing tools in the electronics industry. Concerned with control of driving signal, however, general strategy to optimize jetting stability has not been understood well, because of the inherent complex multi-physics nature in inkjet phenomena. Motivated by this, present study investigates the effect of driving waveforms of piezoelectric head on jetting characteristics of DOD inkjet system focused on jetting stability with phase matching of pressure waves in the print head. The results show that velocities and volumes of the ink jetted droplets were linear relations with the driving signal's maximum voltage, while periodic behaviors are observed with the driving signal's pulse widths.

• Journal of Electrical Engineering and Technology
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• v.13 no.4
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• pp.1644-1654
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• 2018

Eigenvalue distributions for a periodic metal-insulator-metal waveguide, classified into the point spectrum and the discretized continuous spectrum (DCS), are investigated as functions of frequencies, gap widths, and periods. Muller's method is suggested for solving exact eigenvalues, and we propose the scheme for finding proper initial values in the Muller's method by considering only ${\Re}e({\varepsilon}_r)$ in the dispersion equation. We then find that anti-crossing behavior, repulsive effect between the point spectrum and the DCS, becomes stronger when the real parts of the roots in the point spectrum have smaller values. Finally, we examine the transmittances of a single subwavelength slit for real metals using the mode matching technique. The transmittances in real metals similarly follow those of the perfect electric conductor (PEC) at low frequencies, while the patterns at higher frequencies begin to differ from the PEC.

• Journal of Institute of Control, Robotics and Systems
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• v.18 no.4
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• pp.384-390
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• 2012

In this paper, we analyzed the navigation error of TERCOM (TErrain COntour Matching), which is TRN (Terrain Referenced Navigation) batch processing, caused by scale factor error of radar altimeter and proved the possibility of false position fix when we use the TERCOM's feature matching algorithm. Based on these, we proposed the new TRN batch processing algorithm using the slope measurements of terrain. The proposed technique measures on periodic changes in the slope of the terrain elevation profile, and these measurements are used in the feature matching algorithm. By using the slope of terrain data, the impact of scale factor errors can be compensated. By simulation, we verified improved outcome using this approach compared to the result using the conventional method.

• The Journal of the Acoustical Society of Korea
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• v.24 no.7
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• pp.402-409
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• 2005

In this paper. we propose a coding method using a matching pursuit algorithm in a strongly periodic highband signal. Also. we propose an efficient quantizer for the estimated parameters : spectral magnitude and phase. Based on the error concealment principle and sinusoidal model. the MP algorithm requires the high-precision pitch period estimation. To estimate more accurate pitch period. the refined pitch obtained from lowband speech is used. which increases the efficiency of bit allocation. The spectral magnitude parameters are quantized by the method which is combined with MDCT (Modified Discrete Cosine Transform) and multi-stage structure. The spectral phase quantizer uses the $2{\pi}$ modular characteristic of phases and the weighted function by spectral magnitudes. To evaluate the efficiency of the proposed method. we applied it to analysis-by-synthesis system. Furthermore we suggest the possibillity of scalable wideband speech codecs based on band-split structure.