• 제목/요약/키워드: Statistical moment

검색결과 315건 처리시간 0.025초

퓨리에 변환을 이용한 키 프레임 추출 (Key frame extraction using Fourier transform)

  • 이중용;문영식
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2001년도 제14회 신호처리 합동 학술대회 논문집
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    • pp.179-182
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    • 2001
  • In this paper. a key frame extraction algorithm for browsing and searching the summary of a video is proposed. Toward this end, important frames representing a shot are selected according to the correlations among frames. by using the Fourier descriptor which is useful for the shot boundary detection. To quantitatively evaluate the importance of selected frames. a new measure based on correlation coefficients of frames is proposed. If there are several frames with a same importance. another criteria is introduced to break the tie. by computing the partial moment of subframes including each candidate key frame so that the distortion rate is minimized Since a key frame extraction algorithm can be evaluated subjectively. the performance of the proposed algorithm has been verified by a statistical test. Experiments show that more than 20% improvement has been obtained by the proposed algorithm compared to existing methods.

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통계적 부분선형화 방법을 이용한 선체의 불규칙 횡동요 운동의 해석 (Analysis of Random Ship Rolling Using Partial Stochastic Linearization)

  • 김동수;이원경
    • 대한조선학회논문집
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    • 제32권1호
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    • pp.37-41
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    • 1995
  • 불규칙 해상에서의 선체의 횡동요운동을 해석하기 위하여 통계적 부분선형화 방법을 사용하였다. 선형 1자유도계인 횡동요 운동 모델에 2차의 비선형 감쇠항과 3차 및 5차, 7차, 9차, 11차의 비선형 복원모멘트를 추가하였으며 불규칙 기진모멘트는 가우스 백색잡음으로 가정하였다. 이 해석 결과를 등가선형화 방법으로 구한결과와 비교한 결과 부분선형화 방법이 반드시 더 정확한 결과를 주는 것은 아니란 점을 확인하였다.

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평균 벡터의 평활함수모형에 대한 안부점근사 -스튜던트화 분산을 중심으로- (Saddlepoint Approximation to the Smooth Functions of Means Model)

  • 나종화;김주성
    • 응용통계연구
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    • 제14권2호
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    • pp.333-344
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    • 2001
  • 통계적 추론에 사용되는 많은 통계량들은 평균벡터의 평활함수의 형태로 표현이 가능하다. 본 연구에서는 이들 통계량들의 분포함수에 대한 안부점근사법을 제시하였다. 이 방법은 Na(1998)에서 제시된 일반적 통계량의 분포함수에 대한 안부점근사법이 평균벡터의 평활함수모형에 특히 유용하게 사용될 수 있음을 보인 것이다. 이 근사법은 정규근사에 비해 근사의 정도가 뛰어나며, 특히 통계량의 꼬리부분의 확률에 대해서도 정확도가 그대로 유지되는 장점이 있어 정밀한 추론이 요구되는 많은 문제에 효과적으로 사용될 수 있다. 모의 실험에 사용할 평균벡터의 평활함수 모형으로는 스튜던트화 분산을 고려하였다.

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거더교량의 횡방향 하중효과의 확률론적 분석 (Statistical Analysis of Transverse Load Effects in Girder Bridges)

  • 오병환;유영;최영철;이준혁;김광수
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2001년도 가을 학술발표회 논문집
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    • pp.859-864
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    • 2001
  • An effective live load model for analyzing probable maximum live load effects such as moment and shear in transverse direction was developed. The main procedure of this live load model is composed of four parts, i.e., firstly, determination of the appropriate influence lines in longitudinal direction, secondly, application of the characteristics of vehicles and traffic patterns in longitudinal direction, thirdly, determination of the appropriate influence lines in transverse direction, and fourthly, application of the characteristics of vehicles and traffic patterns in transverse direction. Through this procedure, the probabilistic distributions of maximum probable load effects are deduced in the form of probability density function (PDF) and/or cumulative density function(CDF). This live load model is able to consider local or global deterioration of bridges in the structural analysis.

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거더교량의 종방향 하중효과의 확률론적 분석 (Statistical Analysis of Longitudinal Load Effects in Girder Bridges)

  • 오병환;유영;최영철;이준혁;김광수
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2001년도 가을 학술발표회 논문집
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    • pp.865-870
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    • 2001
  • An effective live load model for analyzing probable maximum live load effects in longitudinal direction such as moment and shear was developed. The main procedure of this live load model is composed of two parts. Firstly, determination of the appropriate influence lines, and secondly, application of the characteristics of vehicles and traffic patterns. Through this procedure, probabilistic distributions of maximum probable load effects are deduced in the form of probability density function (PDF) or cumulative density function (CDF). The proposed live load model is not limited by bridge types(number of spans or girders) and can consider local or global deterioration of bridges in the analysis. Besides, load effects can be determined at any section without restrictions.

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패션리더쉽과 자신감과의 상관연구 (A Study on the Relationship Between Fashion Leadership and Self-Confidence)

  • 조필교;구은영
    • 한국의류학회지
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    • 제10권2호
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    • pp.51-57
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    • 1986
  • This study was attempted to investigate the relationship between fashion leadership and self-confidence. Self-confidence was measured with Kim's Personality Scale, and fashion leadership was assessed with Hirschman and Adcock's questionnaire. These questionnaires were administered to 412 unmarried women in Taegu. For statistical analysis, the Pearson's Product-moment correlation coefficients, F-test, and Scheffe test were used. The results were as follows: 1. There was highly significant relationship between fashion opinion leadership and fashion innovativeness. 2. There was significant positive relationship between fashion leadership and self-confide-rice. 3. There was significant difference in self-confidence between innovative communicators and non-innovative communicators.

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Experimental test on bridge jointed twin-towered buildings to stochastic wind loads

  • Ni, Z.H.;He, C.K.;Xie, Z.N.;Shi, B.Q.;Chen, D.J.
    • Wind and Structures
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    • 제4권1호
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    • pp.63-72
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    • 2001
  • This paper presents results of a study on wind loads and wind induced dynamic response of bridge jointed twin-towered buildings. Utilizing the high-frequency force balance technique, the drag and moment coefficients measured in wind tunnel tests, and the maximum acceleration rms values on the top floor of towers, are analyzed to examine the influence of building's plan shapes and of intervals between towers. The alongwind, acrosswind and torsional modal force spectra are investigated for generic bridge jointed twin-towered building models which cover twin squares, twin rhombuses, twin triangles, twin triangles with sharp corners cut off, twin rectangles and individual rectangle with the same outline aspect ratio as the twin rectangles. The analysis of the statistical correlation among three components of the aerodynamic force corroborated that the correlation between acrosswind and torsional forces is significant for bridge jointed twin-towered buildings.

The Use of Generalized Gamma-Polynomial Approximation for Hazard Functions

  • Ha, Hyung-Tae
    • 응용통계연구
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    • 제22권6호
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    • pp.1345-1353
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    • 2009
  • We introduce a simple methodology, so-called generalized gamma-polynomial approximation, based on moment-matching technique to approximate survival and hazard functions in the context of parametric survival analysis. We use the generalized gamma-polynomial approximation to approximate the density and distribution functions of convolutions and finite mixtures of random variables, from which the approximated survival and hazard functions are obtained. This technique provides very accurate approximation to the target functions, in addition to their being computationally efficient and easy to implement. In addition, the generalized gamma-polynomial approximations are very stable in middle range of the target distributions, whereas saddlepoint approximations are often unstable in a neighborhood of the mean.

Data-Dependent Choice of Optimal Number of Lags in Variogram Estimation

  • Choi, Seung-Bae;Kang, Chang-Wan;Cho, Jang-Sik
    • 응용통계연구
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    • 제23권3호
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    • pp.609-619
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    • 2010
  • Geostatistical data among spatial data is analyzed in three stages: (1) variogram estimation, (2) model fitting for the estimated variograms and (3) spatial prediction using the fitted variogram model. It is very important to estimate the variograms properly as the first stage(i.e., variogram estimation) affects the next two stages. In general, the variogram is estimated with the moment estimator. To estimate the variogram, we have to decide the 'lag increment' or the 'number of lags'. However, there is no established rule for selecting the number of lags in estimating the variogram. The present paper proposes a method of choosing the optimal number of lags based on the PRESS statistic. To show the usefulness of the proposed method, we perform a small simulation study and show an empirical example with with air pollution data from Korea.

Random vibration of multispan Timoshenko frames due to a moving load

  • Wang, Rong-Tyai;Lin, Jin-Sheng
    • Structural Engineering and Mechanics
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    • 제6권6호
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    • pp.673-691
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    • 1998
  • In this paper, an analytic method to examine the random vibration of multispan Timoshenko frames due to a concentrated load traversing at a constant velocity is presented. A load's magnitude is a stationary process in time with a constant mean value and a variance. Two types of variances of this load are considered: white noise process and cosine process. The effects of both velocity and statistical characteristics of load and span number of the frame on both the mean value and variance of deflection and moment of the structure are investigated. Results obtained from a multispan Timoshenko frame are compared with those of a multispan Bernoulli-Euler frame.