• Title/Summary/Keyword: Average Moments

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Image Retrieval Using Texture Features BDIP and BVLC (BDIP와 BVCL의 질감특징을 이용한 영상검색)

  • 천영덕;서상용;김남철
    • Proceedings of the IEEK Conference
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    • 2001.09a
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    • pp.183-186
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    • 2001
  • In this paper, we first propose new texture features, BVLC (block variation of local correlation coefficients) moments, for content-based image retrieval (CBIR) and then present an image retrieval method based on the fusion of BDIP and BVLC moments. BDIP uses the local probabilities in image blocks to extract valley and edges well. BVLC uses the variations of local correlation coefficients in images blocks to measure texture smoothness well. In order not to be affected with the movement, rotation, and size of an object, the first and second moments of BDIP and BVLC are used for CBIR. Corel DB and Vistex DB are used to evaluate the performance of the proposed retrieval method. Experimental results show that the presented retrieval method yields average 12% better performance than the method using only BDIP or BVLC moments and average 13% better performance than the method using wavelet moments.

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Higher Order Moments of Record Values From the Inverse Weibull Lifetime Model and Edgeworth Approximate Inference

  • Sultan, K.S.
    • International Journal of Reliability and Applications
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    • v.8 no.1
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    • pp.1-16
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    • 2007
  • In this paper, we derive exact explicit expressions for the triple and quadruple moments of the lower record values from inverse the Weibull (IW) distribution. Next, we present and calculate the coefficients of the best linear unbiased estimates of the location and scale parameters of IW distribution (BLUEs) for different choices of the shape parameter and records size. We then use the higher order moments and the calculated BLUEs to compute the mean, variance, and the coefficients of skewness and kurtosis of certain linear functions of lower record values. By using the coefficients of the skewness and kurtosis, we develop approximate confidence intervals for the location and scale parameters of the IW distribution using Edgeworth approximate values and then compare them with the corresponding intervals constructed through Monte Carlo simulations. Finally, we apply the findings of the paper to some simulated data.

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Bending moments in raft of a piled raft system using Winkler analysis

  • Jamil, Irfan;Ahmad, Irshad
    • Geomechanics and Engineering
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    • v.18 no.1
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    • pp.41-48
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    • 2019
  • Bending moments in the raft of a pile raft system is affected by pile-pile interaction and pile-raft interaction, amongst other factors. Three-Dimensional finite element program has to be used to evaluate these bending moments. Winkler type analysis is easy to use but it however ignores these interactions. This paper proposes a very simplified and novel method for finding bending moments in raft of a piled raft based on Winkler type where raft is supported on bed of springs considering pile-pile and pile-raft interaction entitled as "Winkler model for piled raft (WMPR)" The pile and raft spring stiffness are based on load share between pile and raft and average pile raft settlement proposed by Randolph (1994). To verify the results of WMPR, raft bending moments are compared with those obtained from PLAXIS 3D software. A total of sixty analysis have Performed varying different parameters. It is found that raft bending moments obtained from WMPR closely match with bending moments obtained from PLAXIS 3D. A comparison of bending moments ignoring any interaction in Winkler model is also made with PLAXIS-3D, which results in large difference of bending moments. Finally, bending moment results from eight different methods are compared with WMPR for a case study. The WMPR, though, a simple method yielded comparable raft bending moments with the most accurate analysis.

A Laplacian Autoregressive Moving-Average Time Series Model

  • Son, Young-Sook
    • Journal of the Korean Statistical Society
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    • v.22 no.2
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    • pp.259-269
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    • 1993
  • A moving average model, LMA(q) and an autoregressive-moving average model, NLARMA(p, q), with Laplacian marginal distribution are constructed and their properties are discussed; Their autocorrelation structures are completely analogus to those of Gaussian process and they are partially time reversible in the third order moments. Finally, we study the mixing property of NLARMA process.

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Flow pattern characteristics in vertical two phase flow by PDF and signals from conductance probe (確率密度函數와 電導 Prode信號에 의한 垂直二相流의 流動樣式特性)

  • Son, Byung-Jin;Kim, In-Suhk;Lee, Jin
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.10 no.6
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    • pp.814-822
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    • 1986
  • Flow patterns and its transitions in vertical two phase flow of air-water isothermal flow are identified objectively by void output signals and moments computed from the Probability Density Function which is associated with the statistical measurement for time average local void fractions using conductance probe. It has been shown that the probe output signals, PDF distributions and its moments are deterministic criteria of flow pattern and transition classification.

A Study of Optimum Electromagnetic Field Analysis and Application of the Electret Sensor Using Computer Simulation (컴퓨터 시뮬레이션에 의한 일렉트렛트 센서의 최적 전계 해석과 응용)

  • 정동회;김상걸;김성렬;김용주;김영천;이준웅
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1998.06a
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    • pp.435-438
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    • 1998
  • In this paper, Electret is formed to range voltage -5[kV] to -8[kV] by corona charging in PTFE film and sensor is manufactured by method of moments in sensing infra sonic. Charges of charged film are calculated also TSC measurement and induced potential of sensing electrode according to the charges is become aware of computer simulation. Electret Infra Sonic Transducer, which is designed and manufactured according to the potential and electric field simulation in using method of moments, is proved as it is effectively. Because sensitivity that measured under 10[Hz] is that average value of sensitivity rising rate is 6.34 [dB/oct] as average value is $\pm$1 [dB/oct] range -5[kV] to -8[kV] in corona charging film. As a result, it is believed that characteristic of acquired transducer can be application of medical treatment, industry, and animal life researches and the study of noise elimination, what's more, is required.

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Irregular frequency effects in the calculations of the drift forces

  • Liu, Yujie;Falzarano, Jeffrey M.
    • Ocean Systems Engineering
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    • v.9 no.1
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    • pp.97-109
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    • 2019
  • Accurate calculation of the mean drift forces and moments is necessary when studying the higher order excitations on the floater in waves. When taking the time average of the second order forces and moments, the second order potential and motion diminish with only the first order terms remained. However, in the results of the first order forces or motions, the irregular frequency effects are often observed in higher frequencies, which will affect the accuracy of the calculation of the second order forces and moments. Therefore, we need to pay close attention to the irregular frequency effects in the mean drift forces. This paper will discuss about the irregular frequency effects in the calculations of the mean drift forces and validate our in-house program MDL Multi DYN using some examples which are known to have irregular frequency effects. Finally, we prove that it is necessary to remove the effects and demonstrate that the effectiveness of the formula and methods adopted in the development of our program.

A Study on a Relationship Between the Surface Roughness of Fracture CT Specimen Broken by Fatigue Crack Growth and the Moments (피로균열성장에 의해 파단된 CT시험편의 표면조도와 모멘트의 관계에 관한 연구)

  • Kim, Kyun-Suk;Jung, Hyun-Chul;Kim, Kyung-Su;Park, Chan-Joo;Jang, Hos-Seob
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.19 no.4
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    • pp.462-468
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    • 2010
  • Fatigue crack growth caused by surface defects is one of the most important subjects for the evaluation and the assurance of safety in pressure vessels, piping systems, LPG/LNG fuel tank and other various structures. So, this paper aims to investigate the relationship between the surface roughness of fracture CT specimens and the moments on the specimen when doing fatigue test for the evaluation and the assurance of safety of structures from fatigue crack deconstruction. In this experiment, the CT specimens were loaded by a fatigue testing machine with changing loads until they are broken. The surface roughness of the fracture CT specimens was measured using 3D precise shape measuring equipment and digital holography. As a result of this study, It was identified that the average roughnesses are similar at the positions that has a same moments by comparing the results with the moments on the specimen according to the position.

Development of Simulation Method of Doppler Power Spectrum and Raw Time Series Signal Using Average Moments of Radar Wind Profiler (윈드프로파일러의 평균모멘트 값을 이용한 도플러 파워 스펙트럼 및 시계열 원시신호 시뮬레이션기법 개발)

  • Lee, Sang-Yun;Lee, Gyu-Won
    • The Journal of the Korea institute of electronic communication sciences
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    • v.15 no.6
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    • pp.1037-1044
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    • 2020
  • Since radar wind profiler (RWP) provides wind field data with high time and space resolution in all weather conditions, their verification of the accuracy and quality is essential. The simultaneous wind measurement from rawinsonde is commonly used to evaluate wind vectors from RWP. In this study, the simulation algorithm which produces the spectrum and raw time series (I/Q) data from the average values of moments is presented as a step-by-step verification method for the signal processing algorithm. The possibility of the simulation algorithm was also confirmed through comparison with the raw data of LAP-3000. The Doppler power spectrum was generated by assuming the density function of the skew-normal distribution and by using the moment values as the parameter. The simulated spectrum was generated through random numbers. In addition, the coherent averaged I/Q data was generated by random phase and inverse discrete Fourier transform, and raw I/Q data was generated through the Dirichlet distribution.