• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.2
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• pp.415-421
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• 2005

The radiating or receiving characteristics of array elements (i.e., antennas) are changed from those of isolated elements due to mutual coupling effects and the array performance becomes different from those originally designed by assuming isolated elements. The effects of mutual coupling on the performance of a rectangular array with triangular grid geometry of dipoles above a ground plane are discussed with respect to element pattern. The concept of element gain function is used to examine the effects of mutual coupling on the array performance in terms of sidelobe level in the uniformly spaced and space-tapered rectangular arrays with triangular grid geometry of dipoles. It was shown that the sidelobe performance improved in the space-tapered array compared to the uniformly spaced array in the presence of mutual coupling effects. Computer simulation results are presented.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.9
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• pp.1050-1055
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• 2010

In this paper, the K band $3{\times}6$ array antenna having unequal input is presented. To control the input impedance of the patch antenna, the length of inset feed is adjusted. Also, the same current in each element is excited by Kirchhoff's law. The proposed unequal impedance array antenna is a nonuniform amplitude array. The bandwidth of the proposed unequal impedance array antenna is wider by 1.5 times than that of the equal array antenna. This broad bandwidth is thought to be due to multiple resonances of patches. The unequal impedance array antennas have fractional bandwidths of 5.07 % and gains of 18.32 dBi.

• The Journal of the Acoustical Society of Korea
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• v.34 no.2
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• pp.117-129
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• 2015

A parametric array is a nonlinear phenomenon that generates a narrow beam of low-frequency sound using the nonlinearity of the medium. The low-frequency sound so generated has a low sound pressure compared with that of sound generated directly. Consequently, a transducer that can generate a primary wave with high directivity and level is required. This study designed, fabricated, and evaluated a multi-resonance transducer as a parametric array source. The designs of the unit transducers and array transducer were based on an analysis model. The design process was repeated to fabricate the optimum transducer. The fabricated transducer array can generate a 189 dB, 190 dB primary wave level at 6.3 m and a 134 dB difference frequency wave using the parametric array phenomenon. The difference frequency wave has a frequency of 15 kHz and high directivity with an $8^{\circ}$ half power beam width in a $12{\times}18{\times}10m$ water tank.

• Proceedings of the Optical Society of Korea Conference
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• 2009.02a
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• pp.225-226
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• 2009

본 연구에서는 마스크리스 노광장치의 두 프로젝션 광학계 사이에 있는 마이크로프리즘 어레이에 관한 연구이다. 마이크로프리즘의 원리와 종류에 대해 알아보고, 마이크로프리즘의 출사부의 모양에 따라 패턴의 모양이 변함을 확인하였다. 그리고 원하는 패턴을 만들 수 있는 마이크로프리즘을 설계하였다.

• Proceedings of the KIEE Conference
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• 2001.11a
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• pp.43-44
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• 2001

인공망막에서의 신호와 파워의 전달은 상당히 중요하고 어려운 일이다 본 연구에서는 레이저 어레이를 사용하여 망막 내에 삽입된 인공망막에 신호와 파워를 전달하는 방법에 대해 연구하고 그러한 시스템을 설계하여 시뮬레이션하였다. 시뮬레이션 결과 $50{\mu}m{\times}50{\mu}m$ 인 포토다이오드에 각 레이저가 충분히 포커싱됨을 확인할 수 있었고 2차원 어레이로서 일대일 대응이 가능함을 보였다.

• Broadcasting and Media Magazine
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• v.19 no.1
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• pp.56-64
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• 2014

본 고에서는 증강현실 오디오 기술에 대한 연구동향을 소개한다. 특히 증강현실 오디오 실현을 위한 핵심기술이라고 할 수 있는 오디오 객체를 획득하기 위한 단일지향성 및 쌍지향성 마이크로폰을 이용한 마이크로폰 어레이 설계 기술과 오디오 채널간의 신호 강도차 분석을 통한 오디오 객체 획득 기술에 대해 설명한다.

• 발명특허
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• v.10 no.5 s.111
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• pp.71-71
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• 1985

반도체, 컴퓨터, 통신기기 분야에서 최첨단 기술제품의 생산 공급을 통해 그동안 국내 전자산업을 선도해 온 금성반도체(대표 : 구자두)는, 지난해 6월 세계 3번째로 반주문형 초대규모 집적회로(VLSI)인 CMOS게이트 어레이를 개발하여 미국 엘에스아이 로직(LISLOGIC)사와 1억 5천만불의 수출계약을 체결함으로써 국내 최초로 주문형 반도체의 수출시대를 연데이어, 4월 10일 여의도 중심부 신한 빌딩 4층에 100여평 규모의 게이트 어레이 디자인 센터를 개관하여 특수한 반도체를 주문하는 고객이 동 제품의 회로 설계과정에 직접참여할 수 있도록 함으로써 수주활동을 본격화 하는 일대 전기를 마련하였다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.9
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• pp.711-723
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• 2017

This paper proposes a flight control system for an organic flight array(OFA) which has a new configuration to consist of multi modularized ducted-fan unmanned aerial vehicles (UAVs). The OFA is able to apply to various missions such as indoor reconnaissance, communication relay, and radar jamming by using capability of hover flight. The OFA has a distinguished advantage due to reconfigurable structure to assemble or separate with respect to its missions or operational conditions. A dynamic modelling of the OFA is derived based on equations of motion of the single ducted-fan modules. In order to apply nonlinear control method, an affine system of attitude dynamics is derived. Moreover, the control system is composed of a back-stepping controller for attitude control and a PID controller for position control. Then the performance of the proposed controller is verified via a numerical simulation under wind disturbance.

• Journal of Korea Society of Industrial Information Systems
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• v.5 no.3
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• pp.117-124
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• 2000

A systolic array is a parallel processing system which consists of processing elements of basic computation capabilities, connected with regular and local communication lines. It has been known that a systolic array is on of effective systems to solve complicated communication problems occurred between densely connected neurons on ANN(Artificial Neural Network). In this paper, a systolic array simulator for the back-propagation ANN, which automatically constructs the proper systolic array for a given number of neurons of the ANN, is designed and constructed. With animation techniques of the simulators, it is easy for users to be able to examine the execution of the back-propagation algorithm on the designed systolic array step by step. Moreover the simulator can perform forward and backward operations of the back-propagation algorithm either in sequence or in parallel on the designed systolic array. Parallel execution can be performed by feeding continuous input patterns and by executing bidirectional propagations on all of processing elements of a systolic array at the same time.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.18 no.12
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• pp.1970-1982
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• 1993

This paper describes an efficient array algorithm for parallel computation of vector-radix two-dimensional (2-D) fast discrete cosine transform (VR-FCT), and its VLSI implementation. By mapping the 2-D VR-FCT onto a 2-D array of processing elements (PEs), the butterfly structure of the VR-FCT can be efficiently importanted with high concurrency and local communication geometry. The proposed array algorithm features architectural modularity, regularity and locality, so that it is very suitable for VLSI realization. Also, no transposition memory is required, which is invitable in the conventional row-column decomposition approach. It has the time complexity of O(N+Nnzp-log2N) for (N*N) 2-D DCT, where Nnzd is the number of non-zero digits in canonic-signed digit(CSD) code, By adopting the CSD arithmetic in circuit desine, the number of addition is reduced by about 30%, as compared to the 2`s complement arithmetic. The computational accuracy analysis for finite wordlength processing is presented. From simulation result, it is estimated that (8*8) 2-D DCT (with Nnzp=4) can be computed in about 0.88 sec at 50 MHz clock frequency, resulting in the throughput rate of about 72 Mega pixels per second.