• The Journal of Engineering Geology
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• v.5 no.1
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• pp.95-103
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• 1995

This paper concerns the use of derivative null constraint in an adaptive array pmcessor in the spatial and frequency domains with respect to a composite array processor to obtain a modified composite array processor. It is assumed that the frequency of interference signals is the same as that of a desired signal, interference directions are different from the desired signal, and interference directions and frequencies are known. Simulation results demonstrate that a higher-order derivative null broadens the null width which is appropriate for eleminating a broadband interference and a zero-order derivative null (i.e., a simple point null) with respect to frequency reduces the residual error inherent in the composite array precessor.

• Proceedings of the Acoustical Society of Korea Conference
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• 1998.06e
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• pp.189-192
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• 1998

본 논문에서는 희소어레이 구조를 응용한 선형제약형 적응어레이 처리기를 제안하였다. 다경로 환경하에서 간섭신호의 제거에 효과적인 공간유화방법을 사용하여 제안된 어레이 처리기의 성능을 분석평가하였다. 선형어레이와 최적화된 센서간격으로 이루어진 선형어레이와 정상어레이 간의 성능을 비교하였다. 실험결과 최적화된 희소어레이를 이용한 선형제약형 적응어레이의 성능이 정상어레이의 성능에 버금가는 것으로 나타났다.

• Proceedings of the Korea Institute of Convergence Signal Processing
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• 2003.06a
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• pp.280-283
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• 2003

어레이 셀 내의 연산에 대한 고성능 처리는 시스톨릭 어레이의 중요한 특징이다. 본 논문에서는 시스톨릭 어레이 구조 내 셀이 또 다른 시스톨릭 어레이 구조를 가지는 슈퍼 시스톨릭 어레이 구조를 제안하고, 그 예로 비트 레블 슈퍼 시스톨릭 정렬기의 설계 및 구현에 대하여 기술한다. 먼저 정규순환방정식으로 표현된 정렬 알고리즘으로부터 워드 레블 1차원 평면 시스톨릭 어레이를 유도한 후 유도된 워드 레블 시스톨릭 어레이를 슈퍼 시스톨릭 어레이로 변환한다. 위의 과정으로 유도된 비트 레블 슈퍼 시스톨릭 정렬기를 RT수준에서 VHDL로 모델링 하여 동작을 검증하였으며, 검증된 비트 레블 슈퍼 시스톨릭 정렬기는 Hynix에서 제공되는 0.35$\mu\textrm{m}$ 셀 라이브러리와 FPGA V200E칩을 사용하여 합성 및 구현되었다.

• The Journal of the Acoustical Society of Korea
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• v.23 no.2
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• pp.125-133
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• 2004

Most of the way shape estimation method using reference sources assume that the reference sources are in the farfield. That is, the reference sources are assumed to be far from the array. However, in applications of the array with reference sources, the reference sources are not far from the way, so that in practical ocean environments, the conventional method using farfield source model fail to estimate the positions of the hydrophones. In this paper, based on the nearfield source model, a subspace-based array shape estimation method was proposed. In the proposed method, nearfield reference source is modeled using the differential time delay at each hydrophone, and nearfield parameters are derived. Using these parameters, a subspace-based array shape estimation method that generalizes the existing farfield subspace fitting method which can work regardless of the range of the source is proposed. The Cramer-Rao lower bound for the proposed method is investigated. The results of the numerical experiments indicate that the proposed method performs well in estimating the shape of a perturbed way regardless of the ranges of the reference sources.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.39 no.5
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• pp.34-42
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• 2002

In this paper, we designed the VLSI array architecture for the high speed processing of the motion estimation used by block matching algorithm. We derived the one dimensional systolic array from the full search block matching algorithm. The data and control signals of the proposed systolic array are passed through adjacent processing element. So proposed architecture has temporal and spatial locality. The I/O ports exists only in the first and last processing elements of the array. This architecture has low pin counts and modular expandability. So the proposed array architecture can be cascaded for different block size and search range.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2002.11a
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• pp.169-174
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• 2002

It has known that the DCMP(Directionally Constrained Minimization of power)and the ZF(Zero Forcing) can improve the SINR performance of an array antenna system by using spatial signature of wireless channel. This paper analyzes performance of DCMP and ZF in multiple scattering environments. To obtain the spatial signature of wireless channel. bothe DOA(Directional of Arrival) and AS(Angular Spread) of the received signals were estimated by using ESPRIT. The performance of the DCMP and the ZF was analyzed theoretically. Through computer simulation, the SINR performance were evaluated.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.7 s.98
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• pp.740-745
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• 2005

This paper concerns estimating a desired signal in a multipath environment using linearly constrained array processor with master-slave type array processing and spatial smoothing method in GSM system. In computer simulation, it is shown that the spatial smoothing approach performs better than the master-slave type array processing while both methods perform better than linearly constrained array processing with respect to SINR and BER performances.

• Proceedings of the Korea Information Processing Society Conference
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• 2006.05a
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• pp.379-382
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• 2006

일반적으로 센서 어레이는 많은 채널의 센서를 가지고 있으므로 분석해야 할 데이터의 양이 많다. 따라서 다변량(多變量) 분석 방법을 이용하는데, 크게 통계적 방법과 신경망 방법을 분석하고자 하는 데이터의 특성이나 분석에 필요한 환경 조건에 맞는 분석 방법을 선택하여 이용한다. 센서 어레이의 신호 패턴을 분석하기 위해 본 연구에서는 상태 천이 모델을 이용하여 측정된 가스의 특성을 반영할 수 있는 통계적 방법에 대해 연구하였다. 센서 어레이 신호 데이터를 패턴 모양의 특성을 나타낼 수 있는 상태 천이 모델로 변환하여 가스 종류 식별이 보다 정확하게 이루어 질 수 있도록 모델을 설계하는데 중점을 두고, 모델링 요소인 '상태'는 일정한 시간 간격으로 샘플링 하였을 때의 신호값으로,'천이 관계는 각 천이 벡터의 각으로 각각 정의하여 각도변이 기반 상태천이 모델링을 고안하였다.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.26 no.3
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• pp.295-302
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• 1990

In this paper, a methodology for the automatic design of the optimal systolic arrays is proposed. Algorithm transformation is the main mathematical tool on which this methodology is based. Also, technique for partitioning algorithm into systolic arrays is presented. Algorithm partitioning is essential when the size of the computational problem is larger than the size of the array. This study results in (a) reduction of the design time of systolic arrays for given algorithms, (b) CRT display of the structures of systolic arrays, and (c) automatic designing of the optimal systolic array by the criteria such as the number of processing elements, bands, and communication paths. The procedure for these results was programmed using HP BASIC language on HP-9836 computer.

• The Journal of the Acoustical Society of Korea
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• v.27 no.5
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• pp.221-228
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• 2008

To estimate array shape with reference sources in SONAR systems, nearfield signal modeling is required for the reference sources near a towed array. Array shape estimation method based on the nearfield signal modeling generally exploits the spatial covariance matrix of the received reference sources. Among those method, nearfield eigenvector method uses the eigenvector corresponding to the maximum eigenvalue as a steering vector of the reference source. In this paper, we propose a simplified subspace fitting method based on the nearfield signal modeling with spherical wave modeling. Furthermore, we analyze performance of the array shape estimation methods based on the nearfield signal modeling for various environments. The results of the numerical experiments indicate that the simplified subspace fitting method and the nearfield eigenvector method with single reference source shows almost similar performance. Furthermore, the simplified subspace fitting method with 2 reference sources consistently estimates the shape of the array regardless of the incident angle of the reference sources, whereas the nearfield eigenvector method cannot apply for the case of 2 reference sources.