742 research outputs found
Tra innovazione e continuità : la dottrina militare cinese dalla tarda età maoista a oggi
No full textRecent advances in computational methods for microsystems
No full textAn algorithm, which combines the use of Domain Decomposition and Model Order Reduction methods based on Proper Orthogonal Decomposition, is proposed. The algorithm allows for the efficient handling of electro-mechanical coupled problems in MEMS, with a strong reduction of computing time with respect to standard monolithic or staggered solution strategies. Examples of coupled electro-mechanical problems, concerning a vibrating beam subject to variable electrostatic forces, are presented and discusse
Tra innovazione e continuità. La dottrina militare cinese dalla tarda età maoista a oggi
No full textPrevailing narratives tend to emphasize discontinuity between China's present and past. In the military realm, reliance on advanced technology in the present is often contrasted with the Maoist principles of the past. This article tries to overturn this perspective, by underlining continuity in China's military doctrine from the late Maoist era to today. Three major factors of continuity are identified: the concepts of relative advantage, people's war, and active defence. The conclusion is that advanced technology has not jeopardized China's doctrinal tradition, which has in fact proved crucial in shaping the PLA's path to technological innovation
Domain decomposition and model order reduction methods applied to the simulation of multiphysics problems in MEMS
No full textCoupled electro-mechanical problems are frequently encountered when dealing with micro electro-mechanical systems (MEMS) with capacitive actuation and/or readout systems; their numerical solution can be extremely time consuming, due to the nonlinearity of the coupling terms. Coupled electrostatic – structural dynamic simulations are carried out in this paper through an innovative numerical procedure, based on the use of a domain decomposition technique and of a proper orthogonal decomposition methodology. The approach is assessed through the analysis of the dynamic response of a doubly clamped beam and of a plane resonator subjected to an electrostatic actuation, showing computational gains up to 98%
Combined domain decomposition and model order reduction methods for the solution of coupled and non-linear problems
No full textA new strategy for the ecient solution of highly nonlinear structural problems
is proposed in this paper, based on the combined use of Domain Decomposition
(DD) and Proper Orthogonal Decomposition (POD) techniques. The formulation here
presented is tailored for applications in elasto-plastic structural dynamics. In this context
the POD is applied to linear domains and a double strategy to update the reduced basis
is adopted. Examples show that a meaningful computational gain of approximately 50%
with respect to a monolithic solution can be obtained
Model order reduction and domain decomposition strategies for the solution of the dynamic elasto-plastic structural problem
No full textA new strategy for the efficient solution of highly nonlinear structural problems is proposed, based on the combined use of Domain Decomposition (DD) and snapshots version of the Proper Orthogonal Decomposition (POD) techniques. The formulation here presented is tailored for applications in elastic-plastic structural dynamics. In this context the POD is applied to domains that remain elastic and a double strategy to update the reduced basis is adopted. First, the Singular Value Decomposition (SVD) proposed allows to update the reduced basis as soon as a new snapshot is stored; secondly, an online adaptation technique of the reduced space is performed, through a plastic check during the reduced analysis. The applications show that the computation time necessary for solving elastic-plastic problems can be reduced of approximately 50%, while keeping accuracy comparable to that obtained for the full model with a classical monolithic method
Coupled domain decomposition–proper orthogonal decomposition methods for the simulation of quasi-brittle fracture processes
No full textIn this paper, we discuss a strategy to reduce the computational costs of the simulation
of dynamic fracture processes in quasi-brittle materials, based on a combination of
domain decomposition (DD) and model order reduction (MOR) techniques. Fracture
processes are simulated by means of three-dimensional finite element models in which
use is made of cohesive elements, introduced on-the-fly wherever a cracking criterion
is attained. The body is initially subdivided into sub-domains; for each sub-domain MOR
is obtained through a proper orthogonal decomposition (POD) of the equations
governing its evolution, until when it starts getting cracked. After crack inception within
a sub-domain, the solution is switched back to the original full-order model for that
sub-domain only. The computational gain attained through the coupled use of DD and
POD thus depends on the geometry of the body, on the topology of sub-domains and,
on top of all, on the spreading of cracking induced by load conditions. Numerical
examples concerning well-established fracture tests are used for validation, and the
attainable reduction of the computing time is discussed at varying decomposition into
sub-domains, even in the absence of a full exploitation of parallel computing
potentialities
A domain decomposition technique applied to the solution of thecoupled electro-mechanical problem
No full textA domain decomposition approach for the solution of the coupled electro-mechanical problem in dynamics
is proposed. The finite element analysis of a coupled electro-mechanical system is frequently found, for
example, in the modelling and design of microsystems and may lead to a burdensome nonlinear problem
solution, particularly in the dynamic case. Two versions of the algorithm are proposed: the first one, called
single-level decomposition, exploits the natural partition of the analysis domain given by the two physics to
be solved; the second one, called two-level decomposition, adds a further subdivision of each physics into
subdomains. The multilevel domain decomposition strategy here proposed is shown to accurately predict the
response of microsystems subjected to electro-mechanical coupling and to allow for a significant reduction
in the computational burden
Memoirs of San Martino, Italy and History of the San Martino Club in Trail, B.C
No full textThis paper details the history of Italian immigrants in Trail, their homeland in San Martino, Italy, and the activities that the San Martino Club puts on in Trail. Food, games, and other cultural traditions are described, having been brought over from Italy to Canada, and kept alive in part through the communal effort of the San Martino Club.Student paper submitted for Anthropology 101
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