Kevin Amaratunga

Hierarchical Solution of PDEs Using Wavelets. (9999)

Williams, John R., Amaratunga, Kevin

In engineering problems, we often require a quick rough estimate of the solution at the preliminary stage, which may later be refined as the design or investigation progresses. The multiresolution...

Dynamic Wave Propagation in Particulate Materials with Different Particle Shapes Using a Discrete Element Method (2007)

John Williams, Nabha Rege, Kevin Amaratunga

In this paper we use a discrete element method to explore the propagation of waves through granular materials consisting of particles with different geometric shapes. We present results for a variety...

(Member ASCE), (2007)

John R. Williams, Kevin Amaratunga, Nabha Rege

In this paper we describe an element-free Boundary Point Method (BPM) for the deformation analysis of solid bodies. The Boundary Point Method uses Gaussian basis functions with radial symmetry which...

SUMMARY (2007)

Kevin Amaratunga

In this paper, we provide an introduction to wavelet representations for complex surfaces (surface wavelets), with the goal of demonstrating their potential for 3D scientific and engineering...

FAST WAVELET COMPUTATION OF 3D INTEGRAL PROBLEMS ON UNSTRUCTURED GRIDS (2007)

Kevin Amaratunga

Abstract. A new class of wavelet bases with interpolating properties are constructed on complex geometries. Specializing to piecewise polynomials, we obtain a family of bases whose scaling functions...

A Fast Wavelet Algorithm for the Reduction of Color Information (2007)

Kevin Amaratunga

Color depth reduction is a common operation in the processing of image data, particularly for image file format conversion or for mapping images to display hardware. A problem of particular interest...

WAVELET REPRESENTATIONS AND THEIR APPLICATION TO THE MODELING, COMPRESSION AND REDUCTION OF SPATIAL DATA (2007)

Kevin Amaratunga

We describe how wavelet representations can be used to efficiently model large spatial data sets, including 3D data on irregular grids. The main advantage of such representations is that they produce...

Solution of the Plane Strain Problem in 2D Elasticity Using the Boundary Point Method (2007)

John R. Williams, Kevin Amaratunga

The Boundary Point Method (BPM) was proposed by Maz'ya [1] as a new approach for the discretization of boundary integral equations. The method differs from the Boundary Element Method (BEM) in...

Interpolating Wavelets on Unstructured Grids for the Fast Computation of 3D Integral Problems (2007)

Kevin Amaratunga

In this paper we present an approach to construct second generation interpolating wavelets to compress the class of intergral operators of the form R K(x # y)dy over an unstructured grid in 3-D. This...

EFFICIENT MODELING OF DATA INTENSIVE INVERSE PROBLEMS USING WAVELET-BASED PRIORITIZATION TECHNIQUES (2007)

Kevin Amaratunga

We describe various wavelet-based prioritization techniques that lead to efficient models for data intensive inverse problems commonly arising in engineering applications. Computer simulations of...

M-Channel Lifting-Based Design of Paraunitary and Biorthogonal Filter Banks with Structural Regularity (2007)

Ying-jui Chen, Soontorn Oraintara, Kevin Amaratunga

This paper presents a lifting-domain design of filter banks with a given McMillan degree. It is based on the M-channel lifting factorizations of the degree-0 and 1 building blocks I 2uv + and uv + +...

VII International Conference on Computational Plasticity COMPLAS 2003 E. Onate and D.R.J. Owen (Eds) c CIMNE, Barcelona, 2003 HIERARCHICAL SOLUTION OF EIGENVALUE (2007)

Problems Using Finite, Raghunathan Sudarshan, Raghunathan Sudarshan, Kevin Amaratunga, Kevin Amaratunga

Many problems in structural mechanics, for example, the determination of critical buckling loads and response to periodic loading can be recast as standard or generalized eigenvalue problems....

A multiresolution finite element method using second generation Hermite multiwavelets (2007)

Raghunathan Sudarshan Stefan, Kevin Amaratunga

In this article, we describe the construction of second generation finite element multiwavelets of the Hermite family. We also give expressions for the fast wavelet transform for these bases. We then...

Wavelet Triangulated Irregular Networks (2003)

Jingsong Wu, Kevin Amaratunga

GIS applications have recently begun to emerge on the Internet. The management of three-dimensional geographic datasets in this distributed environment poses a particularly challenging problem, which...

Design of a distributed, interactive online GIS viewer using wavelets. Forthcoming ASCE (2002)

Jingsong Wu, Kevin Amaratunga, Royol Chitradon

The purpose of this paper is to develop a distributed interactive online GIS (DIOGIS) viewer using wavelet technology. Wavelet analysis is a new mathematical tool that can transform information into...

Multiplierless Approximation of Transforms with Adder Constraint (2002)

Ying-jui Chen, Student Member, Soontorn Oraintara, Trac D. Tran, Kevin Amaratunga, Truong Q. Nguyen, ...

This letter describes an algorithm for systematically finding a multiplierless approximation of transforms by replacing floating-point multipliers with VLSI-friendly binary coefficients of the form 2...

Automatic Road Detection in Grayscale Aerial Images (2000)

Katherine Treash, Kevin Amaratunga

Abstract: Digital aerial photography provides a useful starting point for computerized map generation. Features of interest can be extracted using a variety of image-processing techniques, which...

Design of an Online GIS Viewer by Wavelet Technology (2000)

Jingsong Wu, Kevin Amaratunga, Tuck Meng Lui

Along with the high-speed development of the Internet, users have begun to expect highly interactive online GIS. Wavelet technology provides an efficient approach to achieve this. Wavelet analysis is...

A discrete wavelet transform without edge effects using wavelet extrapolation (1995)

John R. Williams, Kevin Amaratunga, John R. Williamsy, Kevin Amaratungaz

The Discrete Wavelet Transform (DWT) is of considerable practical use in image and signal processing applications. For example, significant compression can be achieved through the use of the DWT. A...

Wavelet Based Green's Function Approach to 2D PDEs (1993)

Kevin Amaratunga, John R. Williams

In this paper we describe how wavelets may be used to solve partial differential equations. These problems are currently solved by techniques such as finite differences, finite elements and...