• Title/Summary/Keyword: Fast Search Algorithm

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Real-Time Face Detection by Estimating the Eye Region Using Neural Network (신경망 기반 눈 영역 추정에 의한 실시간 얼굴 검출 기법)

  • 김주섭;김재희
    • Proceedings of the IEEK Conference
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    • 2001.06d
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    • pp.21-24
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    • 2001
  • In this paper, we present a fast face detection algorithm by estimating the eye region using neural network. To implement a real time face detection system, it is necessary to reduce search space. We limit the search space just to a few pairs of eye candidates. For the selection of them, we first isolate possible eye regions in the fast and robust way by modified histogram equalization. The eye candidates are paired to form an eye pair and each of the eye pair is estimated how close it is to a true eye pair in two aspects : One is how similar the two eye candidates are in shape and the other is how close each of them is to a true eye image A multi-layer perceptron neural network is used to find the eye candidate region's closeness to the true eye image. Just a few best candidates are then verified by eigenfaces. The experimental results show that this approach is fast and reliable. We achieved 94% detection rate with average 0.1 sec Processing time in Pentium III PC in the experiment on 424 gray scale images from MIT, Yale, and Yonsei databases.

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A Hybrid Method for Improvement of Evolutionary Computation (진화 연산의 성능 개선을 위한 하이브리드 방법)

  • Chung, Jin-Ki;Oh, Se-Young
    • Journal of the Korean Institute of Intelligent Systems
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    • v.12 no.4
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    • pp.317-322
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    • 2002
  • The major operations of Evolutionary Computation include crossover, mutation, competition and selection. Although selection does not create new individuals like crossover or mutation, a poor selection mechanism may lead to problems such as taking a long time to reach an optimal solution or even not finding it at all. In view of this, this paper proposes a hybrid Evolutionary Programming (EP) algorithm that exhibits a strong capability to move toward the global optimum even when stuck at a local minimum using a synergistic combination of the following three basic ideas. First, a "local selection" technique is used in conjunction with the normal tournament selection to help escape from a local minimum. Second, the mutation step has been improved with respect to the Fast Evolutionary Programming technique previously developed in our research group. Finally, the crossover and mutation operations of the Genetic Algorithm have been added as a parallel independent branch of the search operation of an EP to enhance search diversity.

A New Approach for Constant DC Link Voltage in a Direct Drive Variable Speed Wind Energy Conversion System

  • Jeevajothi, R.;Devaraj, D.
    • Journal of Electrical Engineering and Technology
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    • v.10 no.2
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    • pp.529-538
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    • 2015
  • Due to the high efficiency and compact mechanical structure, direct drive variable speed generators are used for power conversion in wind turbines. The wind energy conversion system (WECS) considered in this paper consists of a permanent magnet synchronous generator (PMSG), uncontrolled rectifier, dc-dc boost converter controlled with maximum power point tracking (MPPT) and adaptive hysteresis controlled voltage source inverter (VSI). For high utilization of the converter's power capability and stabilizing voltage and power flow, constant DC-link voltage is essential. Step and search MPPT algorithm which senses the rectified voltage ($V_{DC}$) alone and controls the same is used to effectively maximize the output power. The adaptive hysteresis band current control is characterized by fast dynamic response and constant switching frequency. With MPPT and adaptive hysteresis band current control in VSI, the DC link voltage is maintained constant under variable wind speeds and transient grid currents respectively.

An Application of Generic Algorithms to the Distribution System Loss Minimization Re -cofiguration Problem (배전손실 최소화 문제에 있어서 유전알고리즘의 수속특성에 관한 연구)

  • Choi, Dai-Seub;Jung, Soo-Yong
    • Proceedings of the KIEE Conference
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    • 2005.07a
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    • pp.580-582
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    • 2005
  • This paper presents a new method which applies a genetic algorithm(GA) for determining which sectionalizing switch to operate in order to solve the distribution system loss minimization re-configuration problem. The distribution system loss minimization re-configuration problem is in essence a 0-1 planning problem which means that for typical system scales the number of combinations requiring searches becomes extremely large. In order to deal with this problem, a new a roach which applies a GA was presented. Briefly, GA are a type of random number search method, however, they incorporate a multi-point search feature. Further, every point is not is not separately and respectively renewed, therefore, if parallel processing is applied, we can expect a fast solution algorithm to result.

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A Study on the Implementation of Connected-Digit Recognition System and Changes of its Performance (연결 숫자음 인식 시스템의 구현과 성능 변화)

  • Yun Young-Sun;Park Yoon-Sang;Chae Yi-Geun
    • MALSORI
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    • no.45
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    • pp.47-61
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    • 2003
  • In this paper, we consider the implementation of connected digit recognition system and the several approaches to improve its performance. To implement efficiently the fixed or variable length digit recognition system, finite state network (FSN) is required. We merge the word network algorithm that implements the FSN with one pass dynamic programming search algorithm that is used for general speech recognition system for fast search. To find the efficient modeling of digit recognition system, we perform some experiments along the various conditions to affect the performance and summarize the results.

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Real-Time Non-Local Means Image Denoising Algorithm Based on Local Binary Descriptor

  • Yu, Hancheng;Li, Aiting
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.10 no.2
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    • pp.825-836
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    • 2016
  • In this paper, a speed-up technique for the non-local means (NLM) image denoising method based on local binary descriptor (LBD) is proposed. In the NLM, most of the computation time is spent on searching for non-local similar patches in the search window. The local binary descriptor which represents the structure of patch as binary strings is employed to speed up the search process in the NLM. The descriptor allows for a fast and accurate preselection of non-local similar patches by bitwise operations. Using this approach, a tradeoff between time-saving and noise removal can be obtained. Simulations exhibit that despite being principally constructed for speed, the proposed algorithm outperforms in terms of denoising quality as well. Furthermore, a parallel implementation on GPU brings NLM-LBD to real-time image denoising.

Optimal Design of Torque Motor using an Improved Niching Genetic Algorithm (개선된 니칭 유전 알고리즘을 이용한 토크모터의 최적설계)

  • Kim, Jae-Kwang;Cho, Dong-Hyeok;Jung, Hyun-Kyo;Lee, Cheol-Gyun
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.50 no.7
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    • pp.323-330
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    • 2001
  • Niching method enables the genetic algorithm(GA) to be applied to the problems that require the location of multiple solutions in the search space, but these methods have fatal disadvantages. The main disadvantage is that the method requires too much calculation of object function. In this paper, a niching method using restricted competition selection(RCS) combined with a pattern search method(PSM) is proposed to identify multiple niches more efficiently and fast in a multimodal domain. The validity of the proposed method is verified by the simulation of test functions and the optimal design of an torque motor.

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A Adaptive Motion Estimation Using Spatial correlation and Slope of Motion vector for Real Time Processing and Its Architecture (실시간 적응형 Motion Estimation 알고리듬 및 구조 설계)

  • 이준환;김재석
    • Proceedings of the IEEK Conference
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    • 2000.11d
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    • pp.57-60
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    • 2000
  • This paper presents a new adaptive fast motion estimation algorithm along with its architecture. The conventional algorithm such as full - search algorithm, three step algorithm have some disadvantages which are related to the amount of computation, the quality of image and the implementation of hardware, the proposed algorithm uses spatial correlation and a slope of motion vector in order to reduce the amount of computation and preserve good image quality, The proposed algorithm is better than the conventional Block Matching Algorithm(BMA) with regard to the amount of computation and image quality. Also, we propose an efficient at chitecture to implement the proposed algorithm. It is suitable for real time processing application.

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A Study on the Fast Block Matching Algorithm (고속 Block Matching 알고리즘에 관한 연구)

  • 이인홍;박래홍
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.24 no.4
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    • pp.667-674
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    • 1987
  • In this paper an effective block matching algorithm is proposed to find the motion vector. There are two approaches to the estimation of the motion vector in MCC (motion compensated coding), i.e., pel(pixel element) recursive algorithm and block matching algorithm. The search algorithm in this paper is based on the block matching method. The advantage of a proposed algorithm using integral projections is the reduction of the computation time. While the conventional block matching methods have to be computed in 2-dimensional arrays, the proposed algorithm using integral projections can be computed in 1-dimensional arrays. In comparison with conventional block matching methods, a computer simulation shows that though the prediction error increases 0.23 db, it is not detectable for human eyes and the average reduction ratio of computation time obtained from the proposed algorithm is about 3-4.

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A Study on Fast Block Matching Algorithm for the Motion Vector Estimation (이동벡터 추정을 위한 고속 Block Matching Algorithm에 관한 연구)

  • 이인홍;박래홍
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.25 no.2
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    • pp.211-219
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    • 1988
  • In this paper effective block matching algorithms are proposed to find the motion vector. There are two approaches to the estimation of the motion vector in MCC (motion compensated coding), i.e.pel(pixel element) recursive algorithm and block matching algorithm. The search algorithm in this paper is based on the block matching method. The advantage of this algorithm is the reduction of the computation time. In order to reduce the computation time, three mathods are proposed in this paper. These new algorithms are faster than other methods. Compared with the three step algorithm by Koga et al., the average ratio of the computational savings obtained from the proposed algorithm is about 3-4.

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