• Title/Summary/Keyword: Local feature

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Real-Time Head Tracking using Adaptive Boosting in Surveillance (서베일런스에서 Adaptive Boosting을 이용한 실시간 헤드 트래킹)

  • Kang, Sung-Kwan;Lee, Jung-Hyun
    • Journal of Digital Convergence
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    • v.11 no.2
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    • pp.243-248
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    • 2013
  • This paper proposes an effective method using Adaptive Boosting to track a person's head in complex background. By only one way to feature extraction methods are not sufficient for modeling a person's head. Therefore, the method proposed in this paper, several feature extraction methods for the accuracy of the detection head running at the same time. Feature Extraction for the imaging of the head was extracted using sub-region and Haar wavelet transform. Sub-region represents the local characteristics of the head, Haar wavelet transform can indicate the frequency characteristics of face. Therefore, if we use them to extract the features of face, effective modeling is possible. In the proposed method to track down the man's head from the input video in real time, we ues the results after learning Harr-wavelet characteristics of the three types using AdaBoosting algorithm. Originally the AdaBoosting algorithm, there is a very long learning time, if learning data was changes, and then it is need to be performed learning again. In order to overcome this shortcoming, in this research propose efficient method using cascade AdaBoosting. This method reduces the learning time for the imaging of the head, and can respond effectively to changes in the learning data. The proposed method generated classifier with excellent performance using less learning time and learning data. In addition, this method accurately detect and track head of person from a variety of head data in real-time video images.

Spherical Panorama Image Generation Method using Homography and Tracking Algorithm (호모그래피와 추적 알고리즘을 이용한 구면 파노라마 영상 생성 방법)

  • Munkhjargal, Anar;Choi, Hyung-Il
    • The Journal of the Korea Contents Association
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    • v.17 no.3
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    • pp.42-52
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    • 2017
  • Panorama image is a single image obtained by combining images taken at several viewpoints through matching of corresponding points. Existing panoramic image generation methods that find the corresponding points are extracting local invariant feature points in each image to create descriptors and using descriptor matching algorithm. In the case of video sequence, frames may be a lot, so therefore it may costs significant amount of time to generate a panoramic image by the existing method and it may has done unnecessary calculations. In this paper, we propose a method to quickly create a single panoramic image from a video sequence. By assuming that there is no significant changes between frames of the video such as in locally, we use the FAST algorithm that has good repeatability and high-speed calculation to extract feature points and the Lucas-Kanade algorithm as each feature point to track for find the corresponding points in surrounding neighborhood instead of existing descriptor matching algorithms. When homographies are calculated for all images, homography is changed around the center image of video sequence to warp images and obtain a planar panoramic image. Finally, the spherical panoramic image is obtained by performing inverse transformation of the spherical coordinate system. The proposed method was confirmed through the experiments generating panorama image efficiently and more faster than the existing methods.

Scene Text Extraction in Natural Images using Hierarchical Feature Combination and Verification (계층적 특징 결합 및 검증을 이용한 자연이미지에서의 장면 텍스트 추출)

  • 최영우;김길천;송영자;배경숙;조연희;노명철;이성환;변혜란
    • Journal of KIISE:Software and Applications
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    • v.31 no.4
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    • pp.420-438
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    • 2004
  • Artificially or naturally contained texts in the natural images have significant and detailed information about the scenes. If we develop a method that can extract and recognize those texts in real-time, the method can be applied to many important applications. In this paper, we suggest a new method that extracts the text areas in the natural images using the low-level image features of color continuity. gray-level variation and color valiance and that verifies the extracted candidate regions by using the high-level text feature such as stroke. And the two level features are combined hierarchically. The color continuity is used since most of the characters in the same text lesion have the same color, and the gray-level variation is used since the text strokes are distinctive in their gray-values to the background. Also, the color variance is used since the text strokes are distinctive in their gray-values to the background, and this value is more sensitive than the gray-level variations. The text level stroke features are extracted using a multi-resolution wavelet transforms on the local image areas and the feature vectors are input to a SVM(Support Vector Machine) classifier for the verification. We have tested the proposed method using various kinds of the natural images and have confirmed that the extraction rates are very high even in complex background images.

Nonequilibrium Domain Configurations Undergoing Large Angle Rotations in Mesoscopic Magnetic Thin Film Elements (retracted)

  • Choi, B.C.;Hong, Y.K.;Rudge J.;Donohoe G.;Xiao Q.F.
    • Journal of Magnetics
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    • v.11 no.2
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    • pp.61-65
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    • 2006
  • The physical origin of complex dynamic domain configuration in nonequilibrium magnetic systems with mesoscopic length scales has been studied. An increasing complexity in the spatial feature of the evolution is found to accompany the increasing reversal speed, when a ferromagnetic element is driven by progressively faster switching fields applied antiparallel to the initial magnetization direction. As reversal rates approach the characteristic precession frequencies of spin fluctuations, the thermal energy can boost the magnetization into local configurations which are completely different from those experienced during quasistatic reversal. The sensitive dependence of the spatial pattern on switching speed can be understood in terms of a dynamic exchange interaction of thermally excited spins; the coherent modulation of the spins is strongly dependent on the rise time of switching pulses.

Universal SSR Small Signal Stability Analysis Program of Power Systems and its Applications to IEEE Benchmark Systems

  • Kim, Dong-Joon;Nam, Hae-Kon;Moon, Young-Hwan
    • KIEE International Transactions on Power Engineering
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    • v.3A no.3
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    • pp.139-147
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    • 2003
  • The paper presents a novel approach of constructing the state matrix of the multi-machine power system for SSR (subsynchronous resonance) analysis using the linearized equations of individual devices including electrical transmission network dynamics. The machine models in the local d-q reference frame are integrated with the network models in the common R-I reference frame by simply transforming their output equations into the R-I frame where the transformed output is used as the input to the network dynamics or vice versa. The salient feature of the formulation is that it allows for modular construction of various component models without rearranging the overall state space formulation. This universal SSR small signal stability program provides a flexible tool for systematic analyses of SSR small-signal stability impacts of both conventional devices such as generation systems and novel devices such as power electronic apparatus and their controllers. The paper also presents its application results to IEEE benchmark models.

A Study on the Multi-function Processor Unit Implementation for Binary Image Processing (이진영상처리를 위한 다기능 프로세서 장치구현에 관한 연구)

  • 기재조;허윤석;이대영
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.18 no.7
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    • pp.970-979
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    • 1993
  • In this paper, a multi-function processor unit is implemented for binary image processing. This unit consists of a set of address generatior, window pipeline register, look up table, control unit, and two local memories .The merits of multi-function processor unit are more simpler than basic SAP and improved disposal speed. A simple software selection give the various choices of image sizes and it can process the function of smoothing, thinning, feature extraction, and edge detection, selectively or sequentially.

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A Large-scale Structural Mixing Model applied to Blowout of Turbulent Nonpremixed Jet Flames in a Cross air-flow

  • Lee, Kee-Man;Shin, Hyun-Dong
    • 한국연소학회:학술대회논문집
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    • 1997.06a
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    • pp.163-173
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    • 1997
  • This article presents an application of a large-scale structural mixing model (Broadwell et al. 1984) to the blowout of turbulent reacting jets discharging perpendicularly into an unconfined cross air-flow. In an analysis of a common stability curve, a plausible explanation can be made that the phenomenon of blowout is related only to the mixing time scale of the two flows. The most notable observation is that the blowout distance is traced at fixed positions at all times according to the velocity ratio R. Measurements of the lower blowout limits in the liftable flame agree qualitatively with the blowout parameter ${\varepsilon}$, proposed by Broadwell et al. Good agreement between the results calculated by a modified blowout parameter ${\varepsilon}^'$ and experimental results confirms the important effect of a large-scale structure in specifying the stabilization feature of blowouts.

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Sketch Feature Extraction Through Learning Fuzzy Inference Rules with a Neural Network (퍼지규칙의 신경망 학습을 통한 스케치 특징점 추출)

  • Cho, Sung-Mok
    • The Transactions of the Korea Information Processing Society
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    • v.5 no.4
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    • pp.1066-1073
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    • 1998
  • In this paper, we propose a new efficient operator named DBAH (difference between arithmetic mean and harmonic mean) and a technique for extracting sketch features through learning fuzzy inference rules with a neural network. The DBAH operator provide some advantages; sensitivity dependence on local intensities and insensitivity on small rates of intensity change in very dark regions. Also, the proposed fuzzy reasoning technique by a neural network has a good performance in extracting sketch features without human intervention.

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A method for underwater image analysis using bi-dimensional empirical mode decomposition technique

  • Liu, Bo;Lin, Yan
    • Ocean Systems Engineering
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    • v.2 no.2
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    • pp.137-145
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    • 2012
  • Recent developments in underwater image recognition methods have received large attention by the ocean engineering researchers. In this paper, an improved bi-dimensional empirical mode decomposition (BEMD) approach is employed to decompose the given underwater image into intrinsic mode functions (IMFs) and residual. We developed a joint algorithm based on BEMD and Canny operator to extract multi-pixel edge features at multiple scales in IMFs sub-images. So the multiple pixel edge extraction is an advantage of our approach; the other contribution of this method is the realization of the bi-dimensional sifting process, which is realized utilizing regional-based operators to detect local extreme points and constructing radial basis function for curve surface interpolation. The performance of the multi-pixel edge extraction algorithm for processing underwater image is demonstrated in the contrast experiment with both the proposed method and the phase congruency edge detection.

Evaluation of Bearing Strength for Composite Joint (합성접합부에서 지압내력 평가식)

  • 김병국;최완철
    • Proceedings of the Korea Concrete Institute Conference
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    • 2002.10a
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    • pp.347-352
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    • 2002
  • Recent trends in the construction of building frame feature the increase use of composite steel concrete members functioning together in what terms of mixed structural systems. One of such systems, RCS(reinforced concrete column and steel beam) system is introduced and closely examined focusing on bearing strength of the composite joint in this paper. The main objective of this study was to develope one of details to increase bearing capacity while bearing failure is one of the two primary modes of failure in RCS system. Local bearing tests with specimens about 1/3 of the actual concrete column size were performed applying uniform load through steel plate with 100$\times$110mm size. Test results show that specimens with the bearing reinforcement detail developed in this study enhanced the bearing strength by 1.71~3.02 compared to concrete cylinder strength.

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