This paper focuses on methods of constructing of reduced-order models of mechanical systems which preserve the Lagrangian structure of the original system. These methods may be used in combination with standard spatial decomposition methods, such as the Karhunen–Loève expansion, balancing, and wavelet decompositions. The model reduction procedure is implemented for three-dimensional finite-elem...

During the last few years, di erent approaches for integrating ordinary di erential equations on manifolds have been published. In this work, we consider two of these approaches. We present some numerical experiments showing bene ts and some pitfalls when using the new methods. To demonstrate how they work, we compare with well known classical methods, e.g. Newmark and Runge-Kutta methods. AMS ...

Vitamin D and prevention of breast cancer: Pooled analysis Cedric F. Garland a,∗, Edward D. Gorham a, Sharif B. Mohr a, William B. Grant b, Edward L. Giovannucci c, Martin Lipkin d, Harold Newmark e,f, Michael F. Holick g, Frank C. Garland a a University of California, San Diego, Department of Family and Preventive Medicine, 9500 Gilman Drive, 0631C, La Jolla, CA 92093, USA b Sunlight, Nutritio...

The international roughness index (IRI) for evaluating pavement surface roughness is simulated using the power spectral density (PSD) of pavement surface fluctuation. Quarter-car models recommended by the World Bank for measuring pavement roughness are adopted to simulate vehicle response. Surface roughness in time domain is generated based on 36 known PSDs of roughness. Newmark sequential inte...

Associate Professor, Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, Newmark Laboratory, 205 North Mathews Avenue, Urbana, IL 61801, USA Email: [email protected] Undergraduate Student, Department of Aeronautical Engineering, University of Illinois at Urbana-Champaign, Talbot Laboratory, Urbana, IL 61801, USA Email: [email protected] Associate Professo...

This paper is concerned with fast and accurate computation of exterior wave equations truncated via exact circular or spherical nonreflecting boundary conditions (NRBCs, known to be nonlocal in both time and space). We first derive analytic expressions for the underlying convolution kernels, which allow for a rapid and accurate evaluation of the convolution with O(Nt) operations over Nt success...

In this paper, a numerical algorithm using a coupled Galerkin-Differential Quadrature (DQ) method is proposed for the solution of dam-reservoir interaction problem. The governing differential equation of motion of the dam structure is discretized by the Galerkin method and the DQM is used to discretize the fluid domain. The resulting systems of ordinary differential equations are then solved by...

This paper is concerned with fast and accurate computation of exterior wave equations truncated via exact circular or spherical nonreflecting boundary conditions (NRBCs, which are known to be nonlocal in both time and space). We first derive analytic expressions for the underlying convolution kernels, which allow for a rapid and accurate evaluation of the convolution with O(Nt) operations over ...