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Domain Approach (domain + approach)

Distribution by Scientific Domains

Engineering	50%

Selected Abstracts

Tests of radial basis functions in the 3D DRM-MD

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING, Issue 1 2006
Bruno Natalini
Abstract Several global as well as compactly supported radial basis functions were tested in the boundary element dual reciprocity method-multi domain approach (DRM-MD) applied to 3D potential problems. Compactly supported radial basis functions (CS-RBFs) showed the highest accuracy, while the augmented thin plate splines (ATPS) showed the highest consistency in terms of accuracy and convergence for the two examples considered, the Poisson and the advection,diffusion equations. A problem for implementation of the CS-RBFs is the lack of guidelines in choosing the size of the support, which showed to have large influence on the accuracy and convergence when these types of RBFs are used. The ATPS showed satisfactory accuracy and since its use does not involve any extra parameters, at the moment it is this function that is the choice of the authors for use in the DRM-MD. Copyright © 2005 John Wiley & Sons, Ltd. [source]

Aeroelastic forces and dynamic response of long-span bridges

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 6 2004
Massimiliano Lazzari
Abstract In this paper a time domain approach for predicting the non-linear dynamic response of long-span bridges is presented. In particular the method that leads to the formulation of aeroelastic and buffeting forces in the time domain is illustrated in detail, where a recursive algorithm for the memory term's integration is properly developed. Moreover in such an approach the forces' expressions, usually formulated according to quasi-static theory, have been substituted by expressions including the frequency-dependent characteristics. Such expressions of aeroelastic and buffeting forces are made explicit in the time domain by means of the convolution integral that involves the impulse functions and the structural motion or the fluctuating velocities. A finite element model (FEM) has been developed within the framework of geometrically non linear analysis, by using 3-d degenerated finite element. The proposed procedure can be used to analyze both the flutter instability phenomenon and buffeting response. Moreover, working in the geometrically non-linearity range, it verifies the possibility of strongly flexible structures of actively resisting the wind loading. Copyright © 2004 John Wiley & Sons, Ltd. [source]

Analysis of dielectric resonator antenna excited by a slot at the waveguide shorted end

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 5 2008
P. Abdulla
Abstract Hemispherical dielectric resonator (HDR) antenna excited with a slot at the short circuited end of waveguide is analyzed theoretically and verified experimentally. The analysis is based on numerical solution of coupled integral equations discretized using the method of moments (MoM). The HDR is modeled using exact magnetic field Green's function because of the equivalent magnetic current in the slot. The field inside the waveguide is expressed in terms of modal vectors and modal functions. For the analysis of HDR antenna part, the modal series is represented as a sum of particular and homogeneous solutions. The particular solution is computed efficiently using spectral domain approach. The scattering parameter for the HDR antenna loaded at the waveguide end slot is calculated and compared with measured and finite element method (FEM) results. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1356,1359, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23382 [source]

Projected Schur complement method for solving non-symmetric systems arising from a smooth fictitious domain approach

NUMERICAL LINEAR ALGEBRA WITH APPLICATIONS, Issue 9 2007
J. Haslinger
Abstract This paper deals with a fast method for solving large-scale algebraic saddle-point systems arising from fictitious domain formulations of elliptic boundary value problems. A new variant of the fictitious domain approach is analyzed. Boundary conditions are enforced by control variables introduced on an auxiliary boundary located outside the original domain. This approach has a significantly higher convergence rate; however, the algebraic systems resulting from finite element discretizations are typically non-symmetric. The presented method is based on the Schur complement reduction. If the stiffness matrix is singular, the reduced system can be formulated again as another saddle-point problem. Its modification by orthogonal projectors leads to an equation that can be efficiently solved using a projected Krylov subspace method for non-symmetric operators. For this purpose, the projected variant of the BiCGSTAB algorithm is derived from the non-projected one. The behavior of the method is illustrated by examples, in which the BiCGSTAB iterations are accelerated by a multigrid strategy. Copyright © 2007 John Wiley & Sons, Ltd. [source]

Parish Nursing: Nurturing Body, Mind, Spirit, and Community

PUBLIC HEALTH NURSING, Issue 2 2003
Ingrid Brudenell R.N., Ph.D.
Abstract Parish nursing is a model of nursing care that focuses on health promotion and disease prevention within a faith community. A descriptive study was conducted in the intermountain West to determine how faith communities form parish nursing programs and what their effect is. Thirteen congregations representing eight denominations with parish nurse/health ministries participated. Parish nurses, parish nurse coordinators from two medical centers, pastors, and hospital chaplains (n = 24) were interviewed and provided documents from their programs. Over time, congregations formed parish nursing/health ministries using strategies in a developmental process. The process involved significant support from the pastor, congregation members, and the parish nurses. Collaboration between faith communities and health organizations were successful using a limited domain approach to attain specific health goals. Parish nursing is making a contribution to integrating faith and health practices, promoting health, and increasing accessibility to health care and congregational activities. Conclusions and recommendations are included for future research, practice, and education. [source]