21,046 research outputs found
Analysis of some acoustics-jet flow interaction problems
Analytical problems in the interactions between the mean-shear flows and the acoustic field in the planar and circular jets are examined. These problems are basic in understanding the effects of coherent large structure on the generation and complications of sound in a sub-sonic jet. Three problems were investigated: (1) spatial (vs. temporal) normal mode analysis in a planar jets; (2) a slightly divergent, planar jet; and (3) acoustic waves in an axisymmetrical jet
Finite Element Solution of Axisymmetrical Dynamic Problems of Shells of Revolution
Finite element solution for natural frequencies and mode shapes of free axisymmetrical vibrations and dynamic response of arbitrary rotationally symmetric shell
Ricci flows with unbounded curvature
We show that any noncompact Riemann surface admits a complete Ricci flow
g(t), t\in[0,\infty), which has unbounded curvature for all t\in[0,\infty).Comment: 12 pages, 1 figure; updated reference
An efficient sparse conjugate gradient solver using a Beneš permutation network
© 2014 Technical University of Munich (TUM).The conjugate gradient (CG) is one of the most widely used iterative methods for solving systems of linear equations. However, parallelizing CG for large sparse systems is difficult due to the inherent irregularity in memory access pattern. We propose a novel processor architecture for the sparse conjugate gradient method. The architecture consists of multiple processing elements and memory banks, and is able to compute efficiently both sparse matrix-vector multiplication, and other dense vector operations. A Beneš permutation network with an optimised control scheme is introduced to reduce memory bank conflicts without expensive logic. We describe a heuristics for offline scheduling, the effect of which is captured in a parametric model for estimating the performance of designs generated from our approach
Averaging approximation to singularly perturbed nonlinear stochastic wave equations
An averaging method is applied to derive effective approximation to the
following singularly perturbed nonlinear stochastic damped wave equation \nu
u_{tt}+u_t=\D u+f(u)+\nu^\alpha\dot{W} on an open bounded domain
\,, \,. Here is a small parameter
characterising the singular perturbation, and \,, \,, parametrises the strength of the noise. Some scaling transformations
and the martingale representation theorem yield the following effective
approximation for small , u_t=\D u+f(u)+\nu^\alpha\dot{W} to an error of
\ord{\nu^\alpha}\,.Comment: 16 pages. Submitte
Yang-Mills Flow and Uniformization Theorems
We consider a parabolic-like systems of differential equations involving
geometrical quantities to examine uniformization theorems for two- and
three-dimensional closed orientable manifolds. We find that in the
two-dimensional case there is a simple gauge theoretic flow for a connection
built from a Riemannian structure, and that the convergence of the flow to the
fixed points is consistent with the Poincare Uniformization Theorem. We
construct a similar system for the three-dimensional case. Here the connection
is built from a Riemannian geometry, an SO(3) connection and two other 1-form
fields which take their values in the SO(3) algebra. The flat connections
include the eight homogeneous geometries relevant to the three-dimensional
uniformization theorem conjectured by W. Thurston. The fixed points of the flow
include, besides the flat connections (and their local deformations), non-flat
solutions of the Yang-Mills equations. These latter "instanton" configurations
may be relevant to the fact that generic 3-manifolds do not admit one of the
homogeneous geometries, but may be decomposed into "simple 3-manifolds" which
do.Comment: 21 pages, Latex, 5 Postscript figures, uses epsf.st
Evaluation of an indigenous early intervention model for Chinese persons with early dementia
ePoster Session 6: Strengthening the social and cultural wellbeing of individuals, families and communities – promoting resilience, empowerment, safety and respectConference Theme: Promoting Social and Economic Equality: Responses from Social Work and Social DevelopmentIntroduction: The World Health Organization considers Dementia as a public health priority. The
ageing population logicaly implies a growing population in persons with Dementia. Tung Wah Group
of Hospitals started the Circle of Care project in 209. Integrating the Chinese cultural concept of
body and mind linkage, the organization developed an evidence-driven, culturaly sensitve and
holistic intervention for persons with early Dementia.
Aims: This study is to evaluate the efectivenes of this pilot care intervention.
Methodology: The study adopted a quasi-experimental design. Al the older adults who joined the
programme were invited to join the study as participants of the intervention group. Older adults with a
compatible mental abilty recruited from a Day Care Centre in the same district were invited to join as
participants of the comparison group. The participants in the intervention group were interviewed
before the intervention (t0), right after the intervention (t1) and 3 months after the intervention (t2).
Information was colected from the care-givers as wel. As for the participants in the comparison
group, interviews were ofered at t0 and t2 only. Dependent variables include the cognitve abilty,
physical abilty, quality of life and depresion of the older adults as wel as the perceived relationship
betwen the older adults and the carers.
Findings: Thirty-two older adults and 31 carers joined the intervention group with 2 older adults in
the comparison group. The within group analysis of the intervention group showed statistical
signifcant changes in the cognitve abilty, quality of life and depresed mod of the older adults. The
betwen group analysis indicated diferences in expected direction. In particular, the changes in
functional reach test, depresion and quality of life were with statistical signifcance.
Conclusion: The pilot study shows that he intervention is efective.published_or_final_versio
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