• 제목/요약/키워드: adaptive algorithm

검색결과 4,661건 처리시간 0.039초

적응적 거리를 이용한 지문 정합 방법 (Fingerprint Minutia Matching Using Adaptive Distance)

  • 이동재;김선주;이상준;김재희
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2000년도 추계종합학술대회 논문집(4)
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    • pp.263-266
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    • 2000
  • We proposes a new fingerprint minutia matching algorithm which matches the fingerprint minutiae by using adaptive distance. In general, fingerprint is deformed by pressure and orientation when a user press his fingerprint to sensor. These nonlinear deformations change the distance between minutiae and reduce verification rate. We define the adaptive distance using ridge frequency. Adaptive distance normalizes the distance between minutiae and compensates for nonlinear deformation. Our algorithm can distinguish two different fingerprints better and is more robust. Experimental results show that the performance of the proposed algorithm is superior to using Euclidean distance.

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A Study on The Jump Error Smoothing Scheme by Fuzzy Logic

  • Lee, Tae-Gyoo;Kim, Kwang-Jin
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2001년도 ICCAS
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    • pp.56.3-56
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    • 2001
  • This study describes the jump error smoothing scheme with fuzzy logic based on the scalar adaptive filter. The scalar adaptive filter is an useful algorithm for smoothing abrupt jump errors. However, the performances of scalar adaptive algorithm depend on the variance of real signal. So to design an effective algorithm, many informations of real and jump signal are required. In this paper, the fuzzy rules are designed by the analysis of scalar adaptive filter, and then the improved and simplified scheme is developed for smoothing the jump error. Simulations to INS/GPS integrated system show that the proposed method is effective.

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3축 가속도 센서를 이용한 실시간 걸음 수 검출 알고리즘 (Real-Time Step Count Detection Algorithm Using a Tri-Axial Accelerometer)

  • 김윤경;김성목;노형석;조위덕
    • 인터넷정보학회논문지
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    • 제12권3호
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    • pp.17-26
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    • 2011
  • 본 논문에서는 3축 가속도 센서를 이용하여 사람이 보행 시 발생하는 센서 데이터를 획득하여 실시간 걸음 수 검출이 가능한 웨어러블 디바이스를 개발하였다. 피험자 59명을 대상으로 트레드밀에서 Actical 과 본 연구에서 개발된 디바이스를 착용 후 36분 동안 테스트 프로토콜에 따라 느리게 걷기, 걷기, 빠르게 걷기, 천천히 뛰기, 뛰기, 빠르게 뛰기 등의 다양한 걸음 속력에서 테스트를 진행하였다. 3축 가속도 센서의 X, Y, Z축 출력 값을 하나의 대표 값으로 처리하는 신호벡터크기(Signal Vector Magnitude : SVM)를 사용하였다. 또한 정확한 걸음 수를 검출하기 위해 휴리스틱 알고리즘(Heuristic Algorithm : HA)을 제안하고 적응적인 임계값 알고리즘(Adaptive Threshold Algorithm : ATA), 적응적인 잠금 구간 알고리즘(Adaptive Locking Period Algorithm : ALPA)을 제안한다. 실험결과 제안하는 알고리즘의 걸음 수 인식률은 97.34%로 Actical의 인식률(91.74%)보다 5.6%향상 되었다.

향상된 수렴 속도와 근단 화자 신호 검출능력을 갖는 적응 반향 제거기 (On Improving Convergence Speed and NET Detection Performance for Adaptive Echo Canceller)

  • 김남선
    • 한국음향학회:학술대회논문집
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    • 한국음향학회 1992년도 학술논문발표회 논문집 제11권 1호
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    • pp.23-28
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    • 1992
  • The purpose of this paper is to develop a new adaptive echo canceller improving convergence speed and near-end-talker detection performance of the conventional echo canceller. In a conventional adaptive echo canceller, an adaptive digital filter with TDL(Tapped-Delay Line) structure modelling the echo path uses the LMS(Least Mean Square) algorithm to cote the coefficients, and NET detector using energy comparison method prevents the adaptive digital filter to update the coefficients during the periods of the NET signal presence. The convergence speed of the LMS algorithm depends on the eigenvalue spread ratio of the reference signal and NET detector using the energy comparison method yields poor detection performance if the magnitude of the NET signal is small. This paper presents a new adaptive echo canceller which uses the pre-whitening filter to improve the convergence speed of the LMS algorithm. The pre-whitening filter is realized by using a low-order lattice predictor. Also, a new NET signal detection algorithm is presented, where the start point of the NET signal is detected by computing the cross-correlation coefficient between the primary input and the ADF(Adaptive Digital Filter) output while the end point is detected by using the energy comparison method. The simulation results show that the convergence speed of the proposed adaptive echo canceller is faster than that of the conventional echo canceller and the cross-correlation coefficient yield more accurate detection of the start point of the NET signal.

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향상된 적응형 유전 알고리즘을 이용한 컨포멀 배열 안테나의 빔 합성 연구 (Study on Pattern Synthesis of Conformal Array Antenna Using Enhanced Adaptive Genetic Algorithm)

  • 성철민;이재덕;한인희;류홍균;이규송;박동철
    • 한국전자파학회논문지
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    • 제25권5호
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    • pp.592-600
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    • 2014
  • 본 논문에서는 2차 함수 곡선의 회전체 곡면 위에 있는 배열 안테나의 빔 합성을 위한 Enhanced Adaptive Genetic Algorithm(EAGA)을 제안하였다. 제안된 알고리즘은 더 빠른 수렴 속도와 더 낮은 비용함수 값을 얻기 위해 Adaptive Genetic Algorithm(AGA)과 Invasive Weed Optimization(IWO)을 결합시켰다. 각 안테나 소자의 급전 크기와 위상의 최적화된 값은 EAGA를 통해 구하였으며, 이 결과를 통해 EAGA가 컨포멀 배열 안테나의 패턴 합성 알고리즘으로써 AGA보다 더 우수함을 보였다.

상부공격 지능탄의 회전각 적응제어 기법 연구 (A Study on the Adaptive Roll Control Scheme for the Top Attack Smart Projectile)

  • 홍종태;정수경;최상경
    • 한국군사과학기술학회지
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    • 제3권2호
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    • pp.61-70
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    • 2000
  • An Adaptive Positive Position Feedback method is presented for controlling the roll of the supersonic smart projectile. The proposed strategy combines the attractive attributes of Positive Position Feedback(PPF) of Goh and Caughey, and Lyapunov stability theorem. The parameters of Adaptive-PFF controller are adjusted in an adaptive mauler in order to follow the performance of an optimal reference model. In this way, optimal damping and zero steady-state errors can be achieved even in the presence of uncertain or changing plant parameters. The performance obtained with the Adaptive-PPF algorithm is compared with conventional PPF control algorithm. The results obtained emphasize the potential of Adaptive-PPF algorithm as an efficient means for controlling plants such as supersonic flight systems with uncertainties in real time.

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IMM 알고리듬을 이용한 적응 최신화 빈도 추적 (Adaptive Update Rate Tracking Using IMM Algorithm)

  • 신형조;홍선목
    • 전자공학회논문지B
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    • 제30B권12호
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    • pp.59-66
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    • 1993
  • In this paper we propose an adaptive update rate tracking algorithm for a phased array radar, based on the interacting multiple model(IMM) algorithm. The purpose of the IMM algorithm hers is twofold: 1) to estimate and predict the target states, and 2) to estimate the level of the process noise. Using the estimate of the process noise level adapted to target dynamics, the update interval is determined to maintain a desired prediction accuracy so that the radar system load is minimized. The adaptive update rate tracking algorithm is implemented for a phased array radar and evaluated with Monte Carlo simulations on various trajectories. The evaluation results of the proposed algorithm and a standard Kalman filter without the adaptive update rate control are presented to compare.

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Sparse Reconfigurable Adaptive Filter with an Upgraded Connection Constraint Algorithm

  • Chang, Hong;Hwang, Suk-Seung
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • 제11권4호
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    • pp.305-309
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    • 2011
  • A sparse reconfigurable adaptive filter (SRAF) based on a photonic switch determines the appropriate time delays and weight values for an optical switch implementation of tapped-delay-line (TDL) systems. It is well known that the choice of switch delays is significantly important for efficiently implementing the SRAF. If the same values exist as calculating the sum of weight magnitudes for implementing the connection constraint required by the SRAF, conventional connection algorithm based on sequentially selection the maximum elements might not work perfectly. In an effort to increase the effectiveness of system identification, an upgraded connection algorithm used progressive calculation to obtain the better solution is considered in this paper. The performance of the proposed connection constraint algorithm is illustrated by computer simulation for a system identification application.

모듈화된 웨이블렛 신경망의 적응 구조 (Adaptive Structure of Modular Wavelet Neural Network)

  • 서재용;김용택;김성현;조현찬;전홍태
    • 한국지능시스템학회:학술대회논문집
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    • 한국퍼지및지능시스템학회 2001년도 추계학술대회 학술발표 논문집
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    • pp.247-250
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    • 2001
  • In this paper, we propose an growing and pruning algorithm to design the adaptive structure of modular wavelet neural network(MWNN) with F-projection and geometric growing criterion. Geometric growing criterion consists of estimated error criterion considering local error and angle criterion which attempts to assign wavelet function that is nearly orthogonal to all other existing wavelet functions. These criteria provide a methodology that a network designer can constructs wavelet neural network according to one's intention. The proposed growing algorithm grows the module and the size of modules. Also, the pruning algorithm eliminates unnecessary node of module or module from constructed MWNN to overcome the problem due to localized characteristic of wavelet neural network which is used to modules of MWNN. We apply the proposed constructing algorithm of the adaptive structure of MWNN to approximation problems of 1-D function and 2-D function, and evaluate the effectiveness of the proposed algorithm.

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5소자 배열안테나의 공간 적응 널패턴 제어 알고리즘 성능분석 (Performance Analysis of Spatial Adaptive Null Pattern Control Algorithm for 5 Elements Array Antenna)

  • 안승관;이상정
    • 한국군사과학기술학회지
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    • 제13권2호
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    • pp.313-319
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    • 2010
  • GNSS receiver which uses the weak satellite signal is very vulnerable to the intentional jamming or non-intentional electromagnetic interference. One of the best method to overcome this disadvantage is to use an adaptive array antenna which has the capability of beamforming or nulling to the certain direction. In this paper, the performance of spatial adaptive null pattern control algorithm of 5 element array antenna is analyzed. A control algorithm which is designed in the 5 element array antenna is OPM(Output Power Minimization) which is eliminating the correlation characteristics between a reference antenna and the others. This algorithm can be applied effectively to the satellite navigation's CRPA because the satellite direction is not considered and GNSS signal power is below the thermal noise. The feature of the OPM algorithm is analyzed and the performance is compared with other null pattern control algorithm.