A. Brancati¹, M. H. Aliabadi¹, I. Benedetti^1,2

CMES-Computer Modeling in Engineering & Sciences, Vol.43, No.2, pp. 149-172, 2009, DOI:10.3970/cmes.2009.043.149

Abstract In this paper a new Rapid Acoustic Boundary Element Method (RABEM) is presented using a Hierarchical GMRES solver for 3D acoustic problems. The Adaptive Cross Approximation is used to generate both the system matrix and the right hand side vector. The ACA is also used to evaluate the potential and the particle velocity values at selected internal points. Two different GMRES solution strategies (without preconditioner and with a block diagonal preconditioner) are developed and tested for low and high frequency problems. Implementation of different boundary conditions (i.e. Dirichlet, Neumann and mixed Robin) is also described. More >

E. Brusa¹, E. Franceschinis², S. Morsut²

CMES-Computer Modeling in Engineering & Sciences, Vol.42, No.2, pp. 75-106, 2009, DOI:10.3970/cmes.2009.042.075

Abstract Electrodes motion and positioning are critical issues of the Electric Arc Furnace (EAF) operation in steelmaking process. During the melting process electrode is exposed to some impulsive and harmonic forces, superimposing to the structure's static loading. Unfortunately, structural vibration may interact with the electric arc regulation, because of the dynamic resonance. Instability in the furnace power supplying and dangerous electrode breakage may occur as a consequence of those dynamic effects. In this paper the dynamic behaviour of a real EAF structure is discussed and some numerical models are proposed. Available experimental data, collected by a… More >

Rencheng Song^1,2, Wen Chen^2,3

CMES-Computer Modeling in Engineering & Sciences, Vol.42, No.1, pp. 59-70, 2009, DOI:10.3970/cmes.2009.042.059

Abstract The regularized meshless method (RMM) is a novel boundary-type meshless method but by now has mainly been tested successfully to the regular domain problems in reports. This note makes a further investigation on its solution of irregular domain problems. We find that the method fails to produce satisfactory results for some benchmark problems. The reason is due to the inaccurate calculation of the diagonal elements of the numerical discretization matrix in the original RMM, which have strong effect on the resulting solution accuracy. To overcome this severe drawback, this study introduces the weighted diagonal element More >

D. L. Young^1,3, K. H. Chen², T. Y. Liu³, L. H. Shen³, C. S. Wu³

CMES-Computer Modeling in Engineering & Sciences, Vol.40, No.3, pp. 225-270, 2009, DOI:10.3970/cmes.2009.040.225

Abstract In this article, a hypersingular meshless method (HMM) is extended to solve 3D potential problems for arbitrary domains after a 2D model was successfully developed (Young et al. 2005a). The solutions are represented by a distribution of the double layer potentials instead of the single layer potentials as generally used in the conventional method of fundamental solutions (MFS). By using the desingularization technique to regularize the singularity and hypersingularity of the double layer potentials, the source points can be located exactly on the real boundary to avoid the sensitivity of locating fictitious boundary for putting… More >

K.H. Chen^1,2, J.H. Kao³, J.T. Chen⁴

CMC-Computers, Materials & Continua, Vol.9, No.3, pp. 253-280, 2009, DOI:10.3970/cmc.2009.009.253

Abstract In this paper, solving antiplane piezoelectricity problems with multiple inclusions are attended by using the regularized meshless method (RMM). This is made possible that the troublesome singularity in the MFS disappears by employing the subtracting and adding-back techniques. The governing equations for linearly electro-elastic medium are reduced to two uncoupled Laplace's equations. The representations of two solutions of the two uncoupled system are obtained by using the RMM. By matching interface conditions, the linear algebraic system is obtained. Finally, typical numerical examples are presented and discussed to demonstrate the accuracy of the solutions. More >

Zheng Li^1,2, Wei Zhang¹, Kezhuang Gong¹

CMC-Computers, Materials & Continua, Vol.9, No.3, pp. 209-228, 2009, DOI:10.3970/cmc.2009.009.209

Abstract In this paper, continuous wavelet transform has been applied to inclusion detection in cantilever beams. By means of FEM, a cantilever beam with an inclusion is subjected to an impact on its free end, and its stress wave propagation process is calculated. Here, two kinds of inclusions which are distinct in material behavior have been discussed. And we change the inclusion's sizes in the beam and set it in three different positions to simulate some complicated situations. For soft inclusion, the results show that the arrival times of incident and reflective wave are distinguishable by… More >

Stephen R. Niezgoda¹, Surya R. Kalidindi^1,2

CMC-Computers, Materials & Continua, Vol.14, No.2, pp. 79-98, 2009, DOI:10.3970/cmc.2009.014.079

Abstract The generalized Hough transform is a common technique for feature detection in image processing. In this paper, we develop a size invariant Hough framework for the detection of arbitrary shapes in three dimensional digital microstructure datasets. The Hough transform is efficiently implemented via kernel convolution with complex Hough filters, where shape is captured in the magnitude of the filter and scale in the complex phase. In this paper, we further generalize the concept of a Hough filter by encoding other parameters of interest (e.g. orientation of plate or fiber constituents) in the complex phase, broadening More >

Nadipuram R. Prasad¹, Salvador Almanza-Garcia¹, Thomas T. Lu²

CMC-Computers, Materials & Continua, Vol.14, No.1, pp. 1-22, 2009, DOI:10.3970/cmc.2009.014.001

Abstract The paper presents a revolutionary framework for the modeling, detection, characterization, identification, and machine-learning of anomalous behavior in observed phenomena arising from a large class of unknown and uncertain dynamical systems. An evolved behavior would in general be very difficult to correct unless the specific anomalous event that caused such behavior can be detected early, and any consequence attributed to the specific anomaly following its detection. Substantial investigative time and effort is required to back-track the cause for abnormal behavior and to recreate the event sequence leading to such abnormal behavior. The need to automatically More >

S. Mukherjee¹, S. Chakraborty², I. Manna^1,3

CMC-Computers, Materials & Continua, Vol.10, No.3, pp. 217-228, 2009, DOI:10.3970/cmc.2009.010.217

Abstract Influence of power density and interaction time for austenitisation during laser surface hardening of plain carbon eutectoid steel has been investigated. The analysis involves numerical prediction of thermal and solute diffusion profiles and thereby, the time needed for homogenization of austenite for different processing conditions. Experimental results provide qualitative validation. More >

Mark LaSpina, Gabriel P. Haas

Canadian Journal of Urology, Vol.15, Suppl.4, pp. 3-13, 2008

Abstract Early detection of prostate adenocarcinoma (prostate cancer) through screening tests such as a serum prostatespecifi c antigen (PSA) test and a digital rectal examination (DRE) enables primary care physicians and urologists to offer patients a broader choice of treatments that are also more likely to provide a cure. Whether men are being over treated or over diagnosed through the widespread use of screening tests remains controversial. This review aims to provide general practitioners with a better understanding of different prostate cancer tests that can be performed and to help them decide which patients should be More >