• Title/Summary/Keyword: mode matching

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Polarizability for a Circular Aperture Near a Conducting Plane

  • Park, Yong-Bae;Kim, Il-Han;Eom, Hyo-Joon
    • Journal of electromagnetic engineering and science
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    • v.1 no.2
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    • pp.173-175
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    • 2001
  • A polarizability fur a circular aperture near a conducting plane is derived. The Mantel-transform and mode-matching is used to obtain a simple series solution. The presented series solution is fast convergent so that it is very efficient fur numerical computations.

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A Theoretical Analysis of Thermic Endfire Interstitial Applicator

  • Park, Jong-Kweon;Eom, Hyo-Joon
    • Journal of electromagnetic engineering and science
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    • v.1 no.1
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    • pp.60-62
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    • 2001
  • A novel approach for modeling the thermic endfire interstitial applicator is presented. A hypothetical semi-infinite circular cylinder is added in the endfire direction in order to facilitate the theoretical modeling approach. The Fourier transform and mode-matching technique is utilized to obtain a solution in fast-convergent series Numerical computations for the input impedance are performed to check the Validity of the theoretical model.

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A Study on the Mode Combination for Efficient Calculation of Scattering Matrix in Mode-Matching Techniques (모드정합법에서 효율적인 산란행렬 계산을 위한 모드 조합에 관한 연구)

  • 이용희;이정해;이창화
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.10 no.5
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    • pp.777-785
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    • 1999
  • For an efficient calculation of scattering matrix in mode matching techniques, mode combination has been studied in this paper. A conducting post in rectangular waveguide, which is most commonly utilized in the combline filter structure, is adopted and its scattering matrix is derived. We eliminates the TE and TM modes having little influence on result, which results in the different number of TE and TM modes in each discontinuous region.

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Non-Contact Guided Wave Technique with Enhanced Mode-Selectivity (모드 선택성을 강화한 비접촉식 유도초음파 기술)

  • Kim, Hyun-Mook;Lee, Tae-Hun;Jhang, Kyung-Young
    • Journal of the Korean Society for Nondestructive Testing
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    • v.24 no.6
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    • pp.597-602
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    • 2004
  • In practical applications of guided wave techniques, it is very important but also difficult to identify the propagating modes, and it is preferred to generate and detect a single or less dispersive mode. Also the noncontact method is required in the automated field application. So this paper considers a non-contact guided wave technique with enhanced mode-selectivity, where a laser beam illuminated through arrayed line slits is used as the transmitter and the air-coupled transducer is used as the receiver. The line arrayed laser illumination is a wavelength matching technique that ran generate only a few modes. The air-coupled transducer detects the leaky wave of the propagated guided wave, and by tuning its detection angle we ran detect the selected single mode. Experimental results for a 1mm thick aluminum plate proved the usefulness of the proposed method, and especially it was shown that this method was powerful in the generation and detection of the $a_0$ mode.

Synthesis of a flight control system via nonlinear model matching theory

  • Uchikado, Shigeru;Kobayashi, Nobuaki;Osa, Yasuhiro;Kanai, Kimio;Nakamizo, Takayoshi
    • 제어로봇시스템학회:학술대회논문집
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    • 1994.10a
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    • pp.659-664
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    • 1994
  • In this paper we deal with a synthesis of flight control system via nonlinear model matching theory. First, the longitudinal and lateral-directional equations of aircraft motion an CCV mode are considered except the assumption "variations on steady straight flight due to disturbances are very small". Next, a design method of the dynamic model matching control system based on Hirschorn's Algorithm is proposed to the above nonlinear system. Finally, the proposed control system is applied to the small sized, high speed aircraft, T-2 on CCV mode and numerical simulations are shown to justify the proposed scheme.ed scheme.

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Design of Robust Controller Using Model Following Sliding Mode Without Matching Condition (정합조건을 만족하지 않는 모델 추종 슬라이딩 모드를 이용한 강인 제어기의 설계)

  • Kim, Min-Chan;Park, Seung-Kyu;Ahn, Ho-Kyun;Kwak, Gun-Pyong;Nam, Jing-Rak
    • Proceedings of the KIEE Conference
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    • 2004.07d
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    • pp.2191-2193
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    • 2004
  • The Sliding Mode Control is more robust and give the better performance than the $H_{\infty}$ control if the matching condition is satisfied. So in this paper, a controller which can have the advantages of $H_{\infty}$ control and the SMC is proposed to add the robustness of the SMC to the $H_{\infty}$ controller. The dynamic of proposed sliding surface is the same dynamic as the system controlled by $H_{\infty}$ controller without the uncertainties which satisfy the matching condition.

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The Study on Lossy and Lossless Compression of Binary Hangul Textual Images by Pattern Matching (패턴매칭에 의한 이진 한글문서의 유.무손실 압축에 관한 연구)

  • 김영태;고형화
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.22 no.4
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    • pp.726-736
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    • 1997
  • The textual image compression by pattern matching is a coding scheme that exploits the correlations between patterns. When we compress the Hangul (Korean character) text by patern matching, the collerations between patterns may decrease due to randoem contacts between phonemes. Therefore in this paper we separate connected phonemes to exploit effectively the corrlation between patterns by inducting the amtch. In the process of sequation, we decide whether the patterns have vowel component or not, and then vowels connected with consonant ae separated. When we compare the proposed algorithm with the existing algorith, the compression ratio is increased by 1.3%-3.0% than PMS[5] in lossy mode, by 3.4%-9.1% in lossless mode than that of SPM[7] which is submitted to standard committe for second generation binary compression algorithm.

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Analysis of Scattering Characteristics of a Rectangular Waveguide with Conducting Half Cylinders using the Mode Matching Method (모드매칭법을 이용한 금속의 Half Cylinder가 있는 구형 도파관의 산란 특성 해석)

  • 김원기;천동완;김상태;신철재
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.29 no.8A
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    • pp.962-971
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    • 2004
  • In this paper, we present the numerical analysis method for analyzing scattering characteristics of a rectangular waveguide with the conducting half cylinder using the mode matching method and compute scattering characteristics of a waveguide according to the rotation and changing radius of the half cylinder. Also, in conjunction with the generalized scattering method, the proposed method can be easily applied to a rectangular waveguide with cascade structure of conducting half cylinders. From the simulated result of a two pole filter, resonance frequency could be controlled by the rotation of half cylinders. The simulated result shows good agreement with the HFSS's result. The proposed structure and analysis method are easily applied to the design of waveguide components with conducting half cylinders.

The Scattering Performance of a Junction of Rectangular Waveguide to Coaxial Line with Two Skewed Conducting Posts (두 개의 경사진 금속봉을 가진 구형 도파관과 동축 선로의 접합부의 산란 특성)

  • 이상호;신철재
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.13 no.4
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    • pp.351-358
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    • 2002
  • To determine a scattering performance of a rectangular waveguide with two skewed conducting posts in approximation by the mode matching method and the generalized scattering method is presented in this paper. We determined the optimized result from effective analysis to select the adequate eigenmode number in mode matching method for the skewed two conducting posts. And we obtained the scattering performance of the junction of the waveguide to coaxial line with two skewed conducting posts by application of above method. By this result, it can be seen that the transmission performance at output port of waveguide to coaxial line is 3 ㏈ at the angle, 50°And we obtained the reflection performance to decrease linearly along the skewed angle at input port.