• 제목/요약/키워드: array data

검색결과 1,622건 처리시간 0.023초

워크스테이션 클러스터 상에서 분산공유메모리 인터페이스로 배열 데이터의 공유를 지원하는 Java 패키지의 설계와 구현 (Design and Implementation of a Java Package for Sharing Array Data by the DSM Interface on a Cluster of Workstations)

  • 임혜정;김명
    • 한국멀티미디어학회논문지
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    • 제2권3호
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    • pp.355-365
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    • 1999
  • 본 연구에서는 배열 데이터를 여러 호스트 상에 분산시켜 생성하고 편리하게 공유할 수 있도록 하는 Java 패키지인 JPAS (Java Package for Array Sharing)를 설계하고 구현하였다. JPAS는 순수 Java로 구현되어 이식성이 뛰어나고, Java RMI를 이용하여 분산공유메모리 모델과 같이 위치 독립적인 접근 인터페이스로 배열 데이터를 공유할 수 있도록 한다. JPAS는 네트원 오버헤드로 인한 성능 저하를 막기 위해서, 프로그래머 가 알고 있는 애플리케이션의 특성을 공유 데이터 사용시에 반영할 수 있도록 한다. 또한, 데이터의 일관성을 유지하기 위해서, JPAS의 모든배열 데이터들은 값을 갱신 할수 있는 메소드틀을 갖는다. 실제로, 병렬프로그램들을 작성하여 워크스테이션 클러스터 상에서 실행시켜 본 결과, JPAS가 비교적 우수한 성능의 병렬 프로그래밍 도구임을 보였다.

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A Systolic Array for High-Speed Computing of Full Search Block Matching Algorithm

  • Jung, Soon-Ho;Woo, Chong-Ho
    • 한국멀티미디어학회논문지
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    • 제14권10호
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    • pp.1275-1286
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    • 2011
  • This paper proposes a high speed systolic array architecture for full search block matching algorithm (FBMA). The pixels of the search area for a reference block are input only one time to find the matched candidate block and reused to compute the sum of absolute difference (SAD) for the adjacent candidate blocks. Each row of designed 2-dimensional systolic array compares the reference block with the adjacent blocks of the same row in search area. The lower rows of the designed array get the pixels from the upper row and compute the SAD with reusing the overlapped pixels of the candidate blocks within same column of the search area. This designed array has no data broadcasting and global paths. The comparison with existing architectures shows that this array is superior in terms of throughput through it requires a little more hardware.

Flow-induced instability and nonlinear dynamics of a tube array considering the effect of a clearance gap

  • Lai, Jiang;Sun, Lei;Li, Pengzhou
    • Nuclear Engineering and Technology
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    • 제51권6호
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    • pp.1650-1657
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    • 2019
  • Fluidelastic instability and nonlinear dynamics of tube bundles is a key issue in a steam generator. Especially, once the post-instability motion of the tube becomes larger than the clearance gap to other tubes, effective contact or impact between the tubes under consideration and the other tube inevitable. There is seldom theoretical analysis to the nonlinear dynamic characteristics of a tube array in two-phase flow. In this paper, experimental and numerical studies were utilized to obtain the critical velocity of the flow-induced instability of a rotated triangular tube array. The calculation results agreed well with the experimental data. To explore the post-instability dynamics of the tube array system, a Runge-Kutta scheme was used to solve the nonlinear governing equations of tube motion. The numerical results indicated that, when the flow pitch velocity is larger than the critical velocity, the tube array system is undergoing a limit cycle motion, and the dynamic characteristics of the tube array are almost similar for different void fractions.

임의형상 배열센서에 적용 가능한 다중표적 방위각 추적 알고리즘 (Multiple Target DOA Tracking Algorithm Applicable to Arbitrarily Shaped Array)

  • 류창수
    • 대한전자공학회논문지TE
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    • 제42권2호
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    • pp.1-6
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    • 2005
  • Ryu 등은 선형 선배열센서를 이용하여 표적의 방위각 궤적을 추적하는 알고리즘을 제안하였다. Ryu 등이 제안한 방위각 추적 알고리즘은 선형 선배열센서의 출력신호를 이용하여 신호부공간을 추정하고, 추정된 신호공간으로부터 각 표적의 방위각 이노베이션을 구하며, 이렇게 구한 방위각 이노베이션을 각 표적에 할당된 칼만필터의 입력으로 사용함으로써 표적의 방위각 궤적을 추적한다. 이러한 구조를 가지는 Ryu의 방위각 추적 알고리즘은 별도의 데이터연관 필터가 필요 없으며 효율적이라는 장점을 가지고 있다. 그러나 Ryu의 방위각 추적 알고리즘은 선형 선배열센서를 사용하는 환경에서 제안되었기 때문에 임의형상 배열센서에 적용하기에는 부적합하다. 배열센서를 사용하는 여러 응용분야에서 배열센서를 구성하는 센서들은 실제로 위치오차를 가지며, 배열센서는 임의형상 배열센서가 된다. 본 논문에서는 Ryu 알고리즘의 장점과 추적 성능을 그대로 유지하면서 임의형상 배열센서에 적용할 수 있는 방위각 추적 알고리즘을 제안한다.

FM 방송 기반 멀티스태틱 PCL 시스템 원형 배열 안테나 보정을 위한 Array Manifold 측정 및 검증 (Array Manifold Measurement and Verification for UCA Calibration in Multistatic PCL System based on FM Broadcasting)

  • 박준식;심홍석;안준일;송규하
    • 한국군사과학기술학회지
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    • 제24권2호
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    • pp.165-174
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    • 2021
  • This study describes a method of measurement and verification of array manifold of uniform circular array antenna applicable to multistatic Passive Coherent Location(PCL) system using FM broadcasting. In an environment of outdoor test where FM broadcast signals are scattered, array manifold measurement methods using network analyzer and multi-channel digital receiver are introduced. Also, the descriptions and solutions for the test limits of each measurement method and the considerations affecting the measurement accuracy are presented. In addition, to verify the validity of the measured array manifold, the gain and phase difference were compared with the array manifold data obtained by EM simulation, and the effectiveness and accuracy of the measured array manifolds were compared and analyzed by estimating the direction of arrival of the FM broadcast signal received from the multistatic PCL system.

적응 어레이 프로세싱 (Adaptive array processing)

  • 이상철
    • 전기의세계
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    • 제29권9호
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    • pp.584-593
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    • 1980
  • Conventional radar antenna systems are susceptible to performance degradation caused by unwanted signals received via the antenna sidelobes and/or mainlobes. Adaptive array systems offer possible solution to this interference problem by automatically steering nulls to unwanted signals providing significant system performance improvement. Another important andvantage of the adaptive array is its self-optimization capability which uses the collective incoming noise data for the nulling purposes. This paper provides a tutorial introduction to adaptive arrays as well as some new development of recent research in this area. Optimum link between the antenna theory and signal processing has been sought by illustrating the gain patterns and output signal-to-noise ratio. Signal acqusition methods are shown including a new attempt of the use of spread-spectrum techniques in conjuction with array systems.

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Silicon Nitride Cantilever Array Integrated with Si Heaters and Piezoelectric Sensors for Probe-based Data Storage

  • Nam Hyo-Jin;Kim Young-Sik;Lee Caroline Sunyong;Jin Won-Hyeog;Jang Seong-Soo;Cho Il-Joo;Bu Jong-Uk
    • 정보저장시스템학회논문집
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    • 제1권1호
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    • pp.73-77
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    • 2005
  • In this paper, a new silicon nitride cantilever integrated with silicon heater and piezoelectric sensor has been firstly developed to improve the uniformity of the initial bending and the mechanical stability of the cantilever array for thermo-piezoelectric SPM(scanning probe microscopy) -based data storages. This nitride cantilever shows thickness uniformity less than $2\%$. Data bits of 40 nm in diameter were recorded on PMMA film. The sensitivity of the piezoelectric sensor was 0.615 fC/nm after poling the PZT layer. For high speed operation, 128${\times}$128 probe array was developed.

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Discriminant Analysis of Marketed Liquor by a Multi-channel Taste Evaluation System

  • Kim, Nam-Soo
    • Food Science and Biotechnology
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    • 제14권4호
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    • pp.554-557
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    • 2005
  • As a device for taste sensation, an 8-channel taste evaluation system was prepared and applied for discriminant analysis of marketed liquor. The biomimetic polymer membranes for the system were prepared through a casting procedure by employing polyvinyl chloride, bis (2-ethylhexyl)sebacate as plasticizer and electroactive materials such as valinomycin in the ratio of 33:66:1, and were separately attached over the sensitive area of ion-selective electrodes to construct the corresponding taste sensor array. The sensor array in conjunction with a double junction reference electrode was connected to a high-input impedance amplifier and the amplified sensor signals were interfaced to a personal computer via an A/D converter. When the signal data from the sensor array for 3 groups of marketed liquor like Maesilju, Soju and beer were analyzed by principal component analysis after normalization, it was observed that the 1st, 2nd and 3rd principal component were responsible for most of the total data variance, and the analyzed liquor samples were discriminated well in 2 dimensional principal component planes composed of the 1st-2nd and the 1st-3rd principal component.

An online Calibration Algorithm using binary spreading code for the CDMA-based Adaptive Antenna Array

  • Lee, Chong-Hyun
    • 조명전기설비학회논문지
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    • 제20권9호
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    • pp.32-39
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    • 2006
  • In this paper, an iterative subspace-based calibration algorithm for a CDMA-based antenna array in the presence of unknown gain and phase error is presented. The algorithm does not depend on the array geometry and does not require a prior knowledge of the Directions Of Arrival (DOA) of the signals. The method requires the code sequence of a reference user only. The proposed algorithm is based on the subspace method and root finding approach, and it provides estimates of the calibration vector, the DOA and the channel impulse response, by using the code sequence of a reference user. The performance of the proposed algorithm was investigated by means of computer simulations and was verified using field data measured through a custom-built W-CDMA test-bed. The data show that experimental results match well with the theoretical calibration algorithm. Also, teh study propose an efficient algorithm using the simulated annealing technique. This algorithm overcomes the requirement of initial guessing in the subspace-based approach.

Systolic array 구조를 갖는 움직임 추정기 설계 (Design of a motion estimator with systolic array structure)

  • 정대호;최석준;김환영
    • 전자공학회논문지C
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    • 제34C권10호
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    • pp.36-42
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    • 1997
  • In the whole world, the research about the VLSI implementation of motion estimation algorithm is progressed to actively full (brute force) search algorithm research with the development of systolic array possible to parallel and pipeline processing. But, because of processing time's limit in a field to handle a huge data quantily such as a high definition television, many problems are happened to full search algorithm. In the paper, as a fast processing to using parallel scheme for the serial input image data, motion estimator of systolic array structure verifying that processing time is improved in contrast to the conventional full search algorithm.

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