• 한국전자파학회:학술대회논문집
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• 한국전자파학회 2003년도 종합학술발표회 논문집 Vol.13 No.1
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• pp.487-491
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• 2003

Design procedure of corrugated horn antenna for mm-wave frequency range is presented, and hybrid condition in horn is calculated. Balanced hybrid mode should be converted in the horn from TE11 mode by the proper corrugation dimensions which size are available to be fabricated under the mm-wave short wavelength condition. In this paper, corrugate profiles which satisfy both hybrid condition and fabrication possibility are obtained.. By cylindrical mode theory, the electromagnetic fields both inside hem and corrugation are delivered. Propagation characteristics in hem is calculated by the mode impedance matching method with boundary conditions, and radiation fields are obtained by the Kirchhoff-Hyugen principle to the hem aperture fields. A mm-wave corrugated horn operates on 85 - 115GHz is designed and fabricated, and results of measurement are also shown.

• Journal of Electrical Engineering and Technology
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• 제13권1호
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• pp.393-399
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• 2018

An electrostatic boundary-value problem of a dielectric-wedge-backed, double-slotted conducting wedge is investigated to analyze an asymmetric coplanar waveguide with an infinite dielectric thickness using the Mellin transform and a mode-matching method. Our theoretical solution based on eigenfunction expansion and residue calculus is a rigorous and fast-convergent series form. Numerical computations are conducted to evaluate the potential field, capacitance, and characteristic impedance for various structures of the asymmetric coplanar waveguide. The computed results show good agreement with the simulated results.

• 한국전자파학회논문지
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• 제9권1호
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• pp.108-114
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• 1998

본 논문에서는 도파관 E 면 금속삽입 방볍에 의한 밀리미터파 대역통과 여파기의 설계를 위해 모드매칭법에 의해 산란행렬올 계산하여 설계한 여파기의 전달특성을 분석하고, 설계 방법의 타당성 여부 검증을 위해 WR-34 구형 도파관을 사용하여 30.085-30.885 GHz 대역의 대역통과 여파기를 설계, 제작하였다. 설계, 제작된 대역통과 여파기의 전달특성은 모드매칭법에 의한 해석파 거의 일치하게 측정되었으며, 통과대역내 삽입손실은 최대 0 0.8 dB, 반사손실 -15 dB의 우수한 여파특성을 나타냉으로써 도파관 E-면 금속삽입 형태에 의한 밀리미터파용 대역통과 여파기로서의 적합성을 입증하였다.

• Journal of the Optical Society of Korea
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• 제7권2호
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• pp.89-96
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• 2003

A new method to control the free spectral range of a long period fiber grating is proposed and theoretically analyzed. As the refractive index decreases radially outward in the silica cladding due to graded doping of fluorine, waveguide dispersion in the cladding modes was modified to result in the effective indices change and subsequently the phase matching conditions for coupling with the core mode in a long period fiber grating. Enlargement of the free spectral range in a long period fiber grating was theoretically confirmed.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제17권6호
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• pp.1635-1656
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• 2023

In Bayesian multi-target tracking, the Poisson multi-Bernoulli mixture (PMBM) filter is a state-of-the-art filter based on the methodology of random finite set which is a conjugate prior composed of Poisson point process (PPP) and multi-Bernoulli mixture (MBM). In order to improve the random finite set-based filter utilized in multi-target tracking of sensor scanning, this paper introduces the Poisson multi-Bernoulli mixture filter into time-matching Bayesian filtering framework and derive a tractable and principled method, namely: the time-matching Poisson multi-Bernoulli mixture (TM-PMBM) filter. We also provide the Gaussian mixture implementation of the TM-PMBM filter for linear-Gaussian dynamic and measurement models. Subsequently, we compare the performance of the TM-PMBM filter with other RFS filters based on time-matching method with different birth models under directional continuous scanning and out-of-order discontinuous scanning. The results of simulation demonstrate that the proposed filter not only can effectively reduce the influence of sampling time diversity, but also improve the estimated accuracy of target state along with cardinality.

• 한국광학회지
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• 제2권4호
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• pp.197-202
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• 1991

극초단 레이저 펄스의 펄스폭(pulse width)을 측정하기 위하여 SHG방법을 이용한 실시간(real time) 자기상관계(autocorrelator)를 개발하였다. 본 연구에서 개발한 자기상관계의 측정법위는 142 ps이며, 지연(delay) block을 한쪽 arm에 삽입하면 250ps까지 측정범위가 확장된다. CW mode-locked Nd:YLF 레이저의 공진기 길이가 mode-locker의 RF 주파수와 matching 되었을 때 가장 짧은 20ps의 펄스폭을 측정하였으며, 공진기 길이를 detuning함에 따란 39ps와 47ps의 펄스폭을 측정 하였다.

• ETRI Journal
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• 제19권2호
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• pp.35-47
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• 1997

A power amplifier operating at 3.3 V has been developed for CDMA/AMPS dual-mode cellular phones. It consists of linear GaAs power MESFET's, a new gate bias control circuit, and an output matching circuit which prevents the drain terminal of the second MESF from generating the harmonics. The relationship between the intermodulation distortion and the spectral regrowth of the power amplifier has been investigated with gate bias by using the two-tone test method and the adjacent channel leakage power ratio (ACPR) method of CDMA signals. The dissipation power of the power amplifier with a gate bias control circuit is minimized to below 1000 mW in the range of the low power levels while satisfying the ACPR of less than -26 dBc for CDMA mode. The ACPR of the power amplifier is measured to be -33 dBc at a high output power of 26 dBm.

• 제어로봇시스템학회논문지
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• 제21권2호
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• pp.162-167
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• 2015

In this paper, we propose a F-MBE algorithm for Dual mode seeker (CCD and IIR). The MBE algorithm show improved performance at the IIR target size estimation. but the MBE can't use at Dual Mode seeker. To overcome this problem,, we apply template matching method for CCD target size information. The performance of proposed F-MBE method is tested at target intercept scenario of dual mode seeker equipped missile. The experiment results show that the proposed algorithm has the relatively improved performance.

• 대한기계학회논문집A
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• 제33권9호
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• pp.878-885
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• 2009

One of important factors in designing MEMS resonators for RF filters is obtaining a desired frequency response function (FRF) within a specific frequency range of interest. Because various array-type MEMS resonators have been recently introduced to improve the filter characteristics such as bandwidth, pass-band, and shape factor, the degrees of freedom (DOF) of finite elements for their FRF calculation dramatically increases and therefore raises computational difficulties. In this paper the Krylov subspace-based model order reduction using moment-matching with non-zero expansion points is represented as a numerical solution to perform the frequency response analyses of those array-type MEMS resonators in an efficient way. By matching moments at a frequency around the specific operation range of the array-type resonators, the required FRF can be efficiently calculated regardless of their operating frequency from significantly reduced systems. In addition, because of the characteristics of the moment-matching method, a minimal order of reduced system with a prearranged accuracy can be determined through an error indicator using successive reduced models, which is very useful to automate the order reduction process and FRF calculation for structural optimization iterations. We also found out that the presented method could obtain the FRF of a $6\times6$ array-type resonator within a seventieth of the computational time necessary for the direct method and in addition FRF calculation by the mode superposition method could not even be completed because of a data overflow with a half after calculation of 9,722 eigenmodes.

• 대한전기학회논문지
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• 제43권4호
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• pp.666-672
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• 1994

An H-Plane waveguide component with arbitrary shape is analyzed using finite element method(FEM) Cooperated with boundary element method(BEM). For the application of BEM in the waveguide structure, a ray representation of the waveguide Green's function is used. This technique is applied to the analysis of the waveguide inductive junction. The results are compared with the results of the mode matching technique. The comparison shows good agreement.