Search results for "FORMULATION"
showing 10 items of 265 documents
Test of Special Relativity in a Heavy Ion Storage Ring
2008
A Column Generation Approach to Scheduling of Periodic Tasks
2011
We present an algorithm based on column generation for a real time scheduling problem, in which all tasks appear regularly after a given period. Furthermore, the tasks exchange messages, which have to be transferred over a bus, if the tasks involved are executed on different ECUs. Experiments show that for large instances our preliminary implementation is faster than the previous approach based on an integer linear programming formulation using a state-of-the-art solver.
Mixed Probabilistic-Guaranteed Optimal Design
2009
This chapter deals with the mixed probabilistic-guaranteed approach to optimal design of quasi-brittle membrane shells. Special attention is devoted to different problem formulations and analytical methods for their solution. Optimal thickness distributions are presented for various axisymmetric membrane shells. The presentation follows research results of [BRS03b].
Optimization of structures with unrestricted dynamic shakedown constraints
2015
The unrestricted dynamic shakedown theory is here utilized with the aim to formulate different optimal design problems for structures mainly subjected to seismic loads. In particular, reference is made to plane frame structures constituted by elastic perfectly plastic material subjected to load combinations characterized by the presence of simultaneous fixed and seismic actions. The design problems, formulated on the ground of a statical approach, are devoted to structures with and without seismic protection devices, with special emphasis to seismic isolators. For the proposed design problem formulations different constraints are utilized; actually, for structures without protection devices…
Flavour Les Houches Accord: Interfacing Flavour related Codes
2010
14 páginas, 2 tablas.-- arXiv:1008.0762v2.-- Mahmpudi, F. et al.
Stochastic ship roll motion via path integral method
2010
ABSTRACTThe response of ship roll oscillation under random ice impulsive loads modeled by Poisson arrival process is very important in studying the safety of ships navigation in cold regions. Under both external and parametric random excitations the evolution of the probability density function of roll motion is evaluated using the path integral (PI) approach. The PI method relies on the Chapman-Kolmogorov equation, which governs the response transition probability density functions at two close intervals of time. Once the response probability density function at an early close time is specified, its value at later close time can be evaluated. The PI method is first demonstrated via simple …
Computer simulations of a Lennard-Jones model for Ar1—x(N2)x: A prototype system for quadrupolar glasses
1998
Abstract Recent theoretical studies of orientational ordering in pure and diluted nitrogen crystals are summarized. While pure N2 has a first order phase transition from a plastic crystal to a phase with long-range orientational order, dilution with argon atoms leads to a quadrupolar glass phase. Monte Carlo simulations are used to study these phases, considering also the behavior of isolated N2 impurities in Ar crystals. It is shown that a simple model that neglects electrostatic interactions and takes only Lennard-Jones interactions into account can describe already many properties in qualitative agreement with experiment. Even the slow dynamics of the quadrupole moments can be modeled by…
Quantum simulations in materials science: molecular monolayers and crystals
1999
Low temperature properties and anomalies in crystals and molecular monolayers are studied by path integral Monte Carlo (PIMC) simulations. For light particles (H 2 , D 2 ) adsorbed on graphite anomalies in the transition to the low temperature √3-phases have been observed in experiments and are analyzed by PIMC. The computed thermal expansion of various crystalline materials (Si, N 2 ) is in much better agreement with experiments compared to the results obtained with purely classical simulations.
Submicrometer in-plane integrated surface plasmon cavities.
2007
International audience; The optical properties of in-plane integrated surface plasmon polariton (SPP) cavities comprised of a thin film area sandwiched between two one-dimensional Bragg SPP mirrors are investigated numerically and experimentally. We discuss the resonance condition of these cavities, and we analyze in details the physical origin of the dispersion of this resonance. On the basis of numerical results, we show that in-plane SPP cavities can be used to achieve local SPP field enhancement and antireflecting SPP layers. The numerical results are compared to near-field optical images recorded by operating a photon scanning tunneling microscope. From the near-field images recorded o…
Dark matter stability and Dirac neutrinos using only Standard Model symmetries
2020
We provide a generic framework to obtain stable dark matter along with naturally small Dirac neutrino masses generated at the loop level. This is achieved through the spontaneous breaking of the global $U(1)_{B-L}$ symmetry already present in Standard Model. The $U(1)_{B-L}$ symmetry is broken down to a residual even $\mathcal{Z}_n$; $n \geq 4$ subgroup. The residual $\mathcal{Z}_n$ symmetry simultaneously guarantees dark matter stability and protects the Dirac nature of neutrinos. The $U(1)_{B-L}$ symmetry in our setup is anomaly free and can also be gauged in a straightforward way. Finally, we present an explicit example using our framework to show the idea in action.