• Title/Summary/Keyword: Linear Array

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Optimum Design of Transverse Flux Linear Motor for Maximizing Thrust Force Using Table of Orthogonal Array (직교배열표를 이용한 추력을 최대화하기 위한 횡자속 선형전동기의 최적설계)

  • Hong, Do Kwan;Woo, Byung Chul;Kang, Do Hvun
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.54 no.11
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    • pp.505-510
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    • 2005
  • On this study, we optimized maximizing the thrust force at the TFLM(Transverse Flux Linear Motor) using design of experiments by the table of orthogonal array and the analysis of means(ANOM), and classified the most contributive design factor maximizing the thrust force at the TFLM by analysis of variance(ANOVA). From now on, we are going to apply the required technique to design various uses and shapes of the TFLM.

Analysis of DOA Estimation and Adaptive Beam-forming of MIMO between Linear-circular Array Antennas (선형-원형배열 안테나에 따른 MIMO의 DOA 추정과 적응 빔성형 분석)

  • Yang, Doo-Yeong;Lee, Min-Soo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.6
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    • pp.2777-2784
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    • 2011
  • In this paper, DOA(direction of arrival) of multiple incident signals received from linear array antenna and circular array antenna, which is based on nonparametric estimation algorithm, and adaptive beam-forming algorithm are studied and analyzed. In nonparametric estimation algorithm, we minimize a regularized objective function for finding a estimate of the signal energy as a function of angle, using nonquadratic norm which leads to supper resolution and noise suppression. And then, DOA is estimated by the signal and noise spatial steering vector, and adaptive beam-forming pattern is improved by weight vectors obtained from the spatial vector. Especially, the discrimination ability of DOA and the adaptive beam-forming ability according to antenna array methods and the number of array elements are compared and considered.

A Beamforming Method for a Perturbed Linear Towed Array (비선형 형상 견인 어레이를 위한 빔형성 기법)

  • 김승일;도경철;오원천;윤대희;이충용
    • The Journal of the Acoustical Society of Korea
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    • v.21 no.5
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    • pp.478-484
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    • 2002
  • Linear towed arrays (LTA) have a nonlinear shape due to tow vessel motion, ocean swells and currents. By reasons of nominally linear shape, various towed array shape estimation techniques have been developed since the perturbed shape cause the error in target detection. In this paper,, we propose the beamforming method for the perturbed LTA with simple structure. The proposed method linearizes a nonlinear phase of steering vector with position information measured by two reference sensors. It can be proved using some properties of Markov transition matrix, and iteration number of linearization process is decided by variance of cross phase difference. As a result of computer simulation in the ocean environment, beampattern of the proposed method is almost same with the ideal case in my type of array shape. In the signal-to-noise ratio (SNR) performance simlation, the DOA estimation performance of the proposed beamforming method is evaluated, and the comparison with Bartlett beamformer of the LTA shows that the proposed method can estimate. the spatial characteristic of sources more accuracy.

Modified Multiple Target Angle Tracking Algorithm with Efficient Equation for Angular Innovation (효율적인 방위각 이노베이션 계산식을 가진 수정된 다중표적 방위각 추적 알고리즘)

  • Ryu, Chang-Soo
    • 전자공학회논문지 IE
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    • v.48 no.1
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    • pp.25-29
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    • 2011
  • Ryu et al. proposed a multiple target angle-tracking algorithm with efficient equation for angular innovation, and Ryu's algorithm has good feature that it has no data association problem. Ryu's algorithm is only applicable to linear sensor array, because its efficient equation for angular innovation is derived in case of using a linear sensor array. In a many fields studying multiple target angle-tracking, the various shapes of sensor array are used. In sonar, a cylindrical sensor array is as much used as a linear sensor array, a example is hull mounted sonar. In this paper, Ryu's algorithm is modified to be applicable to cylindrical sensor array, and the tracking performance of a modified algorithm is verified by various computer simulations.

Source Localization Based on Independent Doublet Array (독립적인 센서쌍 배열에 기반한 음원 위치추정 기법)

  • Choi, Young Doo;Lee, Ho Jin;Yoon, Kyung Sik;Lee, Kyun Kyung
    • Journal of the Institute of Electronics and Information Engineers
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    • v.51 no.10
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    • pp.164-170
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    • 2014
  • A single near-field sounde source bearing and ranging method based on a independent doublet array is proposed. In the common case of bearing estimation method, unform linear array or uniform circular array are used. It is constrained retaining aperture because of array structure to estimate the distance of the sound source. Recent using independent doublet array sound source's bearing and distance esmtimation method is proposed by wide aperture. It is limited to the case doublets are located on a straight line. In this paper, we generalize the case and estimate the localization of a sound source in the various array structure. The proposed algorithm was verified performance through simulation.

A Study on an Ultrasonic Phased Array Transducer with a Spherical Liquid Lens (구면 액체 렌즈 초음파 위상 배역 변환기에 관한 연구)

  • 윤영중;박한규
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.32A no.11
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    • pp.9-16
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    • 1995
  • In this paper, an ultrasonic phased array transducer with spherical liquid lens, which utilizes both electronic focusing by linear phased array and variable geometric focusing by spherical lens. is investigated. This system reduces the elevational beamwidth which is disadvantage of the 1-dimensional linear phased array, and adds real-time dynamic focusing capability by controlling the volume of liquid in the lens. A prototype of this transducer is constructed and tested. The experimental results are compared with those of computer simulations. The range of applications are in the hyperthermia applicators or ultrasonic image system with narrow beam and rapid scanning characterisitcs.

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Squint Free Phased Array Antenna System using Artificial Neural Networks

  • Kim, Young-Ki;Jeon, Do-Hong;Thursby, Michael
    • The Journal of Korean Association of Computer Education
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    • v.6 no.3
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    • pp.47-56
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    • 2003
  • We describe a new method for removing non-linear phased array antenna aberration called "squint" problem. To develop a compensation scheme. theoretical antenna and artificial neural networks were used. The purpose of using the artificial neural networks is to develop an antenna system model that represents the steering function of an actual array. The artificial neural networks are also used to implement an inverse model which when concatenated with the antenna or antenna model will correct the "squint" problem. Combining the actual steering function and the inverse model contained in the artificial neural network, alters the steering command to the antenna so that the antenna will point to the desired position instead of squinting. The use of an artificial neural network provides a method of producing a non-linear system that can correct antenna performance. This paper demonstrates the feasibility of generating an inverse steering algorithm with artificial neural networks.

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Defect Detection Using Focused Lamb Waves Generated by Laser (집속형 레이저 유도초음파에 의한 결함검출)

  • Kim, Hong-Joon;Jung, Ji-Hong;Ha, Job;Jhang, Kyung-Young
    • Proceedings of the KSME Conference
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    • 2003.04a
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    • pp.774-779
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    • 2003
  • Arc-shaped line array slits have been used for the laser generation of focused Lamb waves. The spatially expanded Nd:YAG pulse laser was illuminated through the arc-shaped line array slit on the surface of a sample plate to generate the Lamb waves of the same pattern as the slit. Then the generated Lamb waves were focused at the point of which distance from the slit position is dependent on the curvature of slit arc. The proposed method showed better spatial resolution than the conventional linear array slit in the detection of laser machined linear defect and drill machined circular defect on aluminum plates of 1mm thickness.

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Compensation of a Squint Free Phased Array Antenna System using Artificial Neural Networks

  • Kim, Young-Ki;Jeon, Do-Hong;Park, Chiyeon
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.4 no.2
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    • pp.182-186
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    • 2004
  • This paper describes an advanced compensation for non-linear functions designed to remove steering aberrations from phased array antennas. This system alters the steering command applied to the antenna in a way that the appropriate angle commands are given to the array steering software for the antenna to point to the desired position instead of squinting. Artificial neural networks are used to develop the inverse function necessary to correct the aberration. Also a straightforward antenna steering function is implemented with neural networks for the 9-term polynomials of forward steering function. In all cases the aberration is removed resulting in small RMS angular errors across the operational angle space when the actual antenna position is compared with the desired position. The use of neural network model provides a method of producing a non-linear system that can correct antenna performance and demonstrates the feasibility of generating an inverse steering algorithm.

Synthesis of Optimum Broadband Null in Randomly Perturbed Linear Arrays (무작위 오류가 있는 선형 어레이의 최적 광대역 영점 형성)

  • 장병건
    • The Journal of Engineering Geology
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    • v.5 no.1
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    • pp.105-113
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    • 1995
  • If broadband interference signals are incident at an array of sensor/antenna elements, it is desirable to form a set of bnoadband nulls around the directions of the interference signals to improve the array performance. An efficient way of generating a broadband null is to synthesize a derivative null. The performance of a derivative null in a constrained linear array which is subjected to random variations with respect to array weight and element Position is discussed. Computer simulation results are presented.

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