Bin Ma¹, Yuanyuan Hu¹, Jian Li^1,*, Chunpeng Wang¹, Meihong Yang², Yang Zheng³

Computer Systems Science and Engineering, Vol.36, No.1, pp. 189-200, 2021, DOI:10.32604/csse.2021.014138

Abstract This paper presents an algorithm to solve the problem of Photo-Response Non-Uniformity (PRNU) noise facing stabilized video. The stabilized video undergoes in-camera processing like rolling shutter correction. Thus, misalignment exists between the PRNU noises in the adjacent frames owing to the global and local frame registration performed by the in-camera processing. The misalignment makes the reference PRNU noise and the test PRNU noise unable to extract and match accurately. We design a computing method of maximum likelihood estimation algorithm for extracting the PRNU noise from stabilized video frames. Besides, unlike most prior arts tending to match the PRNU noise in… More >

Jian Li¹, Yang Lv¹, Bin Ma^1,*, Meihong Yang², Chunpeng Wang¹, Yang Zheng³

Computer Systems Science and Engineering, Vol.35, No.6, pp. 513-521, 2020, DOI:10.32604/csse.2020.35.513

Abstract Digital video has become one of the most preferred ways for people to share information. Considering people tend to release illegal information in anonymous way, the problem of video source identification attracts more and more attention as an important part of multimedia forensics. The Photo-Response Non-Uniformity (PRNU) based algorithm shows to be a promising solution for the problem of video source identification. However, it is necessary to make a geometric transformation for testing PRNU noise to align it with the reference noise, due to the effect of video stabilization. This paper analyzes the three-dimensional (3D) characteristics of camera jitters and… More >

Sooyeon Park¹, Moonseong Kim², Woochan Lee^{1, *}

CMC-Computers, Materials & Continua, Vol.65, No.2, pp. 1181-1201, 2020, DOI:10.32604/cmc.2020.011245

Abstract With the recent development of big data technology that collects and analyzes various data, the technology that continuously collects and analyzes the observed data is also drawing attention. Moreover, its importance is growing in data collection in areas where people cannot access. In general, it is not easy to properly deploy IoT wireless devices for data collection in these areas, and it is also inappropriate to use general wheelbased mobile devices for relocation. Recently, researches have been actively carried out on hopping moving models in place of wheel-based movement for the inaccessible regions. The majority of studies, however, so far… More >

Shu Minakuchi¹, Tadahito Mizutani¹, Haruka Tsukamoto², Mayuko Nishio², Yoji Okabe³, Nobuo Takeda¹

Structural Durability & Health Monitoring, Vol.4, No.4, pp. 199-220, 2008, DOI:10.3970/sdhm.2008.004.199

Abstract The authors propose a technique to detect centimeter internal damages in large-scale composite structures, using an optical fiber network running throughout the structure. A Brillouin-based distributed strain sensing system with centimeter-order spatial resolution (pre-pump pulse Brillouin optical time domain analysis (PPP-BOTDA)) was utilized to detect residual non-uniform strain in the damaged area. First, Brillouin spectral response depending on the strain profile within the spatial resolution was revealed. The spectral response depending on strain non-uniformity was experimentally quantified with consideration of the general characteristics of the Brillouin gain spectrum. Then, the damage detection procedure was proposed, based on the spectral response.… More >

J.T. Verbis¹, S.V. Tsinopoulos², D. Polyzos²

CMES-Computer Modeling in Engineering & Sciences, Vol.3, No.6, pp. 803-814, 2002, DOI:10.3970/cmes.2002.003.803

Abstract In the present work the iterative effective medium approximation (IEMA) is appropriately used for wave dispersion and attenuation predictions in fiber-reinforced composites that microscopically exhibit a non-uniform fiber distribution. Two types of composites with such irregular topology of fibers are considered. The first contains a regular distribution of clusters of fibers embedded in a composite matrix with uniformly distributed fibers, and the second a uniform distribution of matrix-rich inclusions embedded in a fiber-rich regular composite medium. The resulting from the application of the IEMA scattering problems are solved numerically by means of a two dimensional boundary element method. The obtained… More >

N. Sukumar¹, J. E. Bolander¹

CMES-Computer Modeling in Engineering & Sciences, Vol.4, No.6, pp. 691-706, 2003, DOI:10.3970/cmes.2003.004.691

Abstract In this paper, we explore the numerical approximation of discrete differential operators on non-uniform grids. The Voronoi cell and the notion of natural neighbors are used to approximate the Laplacian and the gradient operator on irregular grids. The underlying weight measure used in the numerical computations is the {\em Laplace weight function}, which has been previously adopted in meshless Galerkin methods. We develop a difference approximation for the diffusion operator on irregular grids, and present numerical solutions for the Poisson equation. On regular grids, the discrete Laplacian is shown to reduce to the classical finite difference scheme. Two techniques to… More >

Ju Hye Park, Jeom Kee Paik, S.N. Atluri

The International Conference on Computational & Experimental Engineering and Sciences, Vol.19, No.3, pp. 69-70, 2011, DOI:10.3970/icces.2011.019.069

Abstract The aim of the present paper is to develop a semi-analytical method which and quickly and accurately compute the ultimate strength response of rectangular plates under combined loads and non-uniform lateral pressure. It is assumed that the plating is simply supported at four edges which are kept straight. A unique feature of developed method was found to give reasonably accurate results for practical design purpose in terms of the large deflection analysis of plates under non uniformed lateral pressure. The present paper treated by analytically solving the nonlinear governing differential equations of the elastic large deflection plate theory. It will… More >

Zhenchuan Wang^1,2, Ruina Xu², Peixue Jiang^2,*

The International Conference on Computational & Experimental Engineering and Sciences, Vol.22, No.3, pp. 154-154, 2019, DOI:10.32604/icces.2019.05023

Abstract Deeply analysis and prediction of turbulent convection heat transfer of supercritical pressure fluid in one-side non-uniform heating vertical tube plays a major role in system design and security. The Over-prediction of convection heat transfer of supercritical pressure fluid in vertical tube is attributed, at least partly, to the invalid of turbulent model on simulating the buoyancy effect. The present paper adopt an improved turbulent model, which is validated suitable to three dimensional model, to simulate flow and heat transfer of supercritical pressure water in vertical non-uniform heating tube. Heat transfer deterioration phenomenon occurs in non-uniform heating condition, while the degree… More >

P. Raghavan¹, S. Ghosh²

CMES-Computer Modeling in Engineering & Sciences, Vol.5, No.2, pp. 151-170, 2004, DOI:10.3970/cmes.2004.005.151

Abstract This paper presents an adaptive multi-level computational model that combines a conventional displacement based finite element model with a microstructural Voronoi cell finite element model for multi-scale analysis of composite structures with non-uniform microstructural heterogeneities as obtained from optical or scanning electron micrographs. Three levels of hierarchy, with different resolutions, are introduced in this model to overcome shortcomings posed by modeling and discretization errors. Among the three levels are: (a) level-0 of pure macroscopic analysis; (b) level-1 of macro-micro coupled modeling, used for signaling the switch over from macroscopic analyses to pure microscopic analyses; and (c) level-2 regions of pure… More >

WJ Richardson^∗, DD van der Voort^∗, E Wilson^†, JE Moore Jr.^∗,‡

Molecular & Cellular Biomechanics, Vol.10, No.3, pp. 245-265, 2013, DOI:10.3970/mcb.2013.010.245

Abstract Non-uniform stress and strain fields are prevalent in many tissues in vivo, and often exacerbated by disease or injury. These mechanical gradients potentially play a role in contributing to pathological conditions, presenting a need for experimental tools to allow investigation of cell behavior within non-uniformly stimulated environments. Herein, we employ two in vitro cell-stretching devices (one previously published; one newly presented) capable of subjecting cells to cyclic, non-uniform stretches upon the surface of either a circular elastomeric membrane or a cylindrical PDMS tube. After 24 hours of cyclic stretch, 10T1/2 cells on both devices showed marked changes in long-axis orientation,… More >