2,129 research outputs found
Group Leaders Optimization Algorithm
We present a new global optimization algorithm in which the influence of the
leaders in social groups is used as an inspiration for the evolutionary
technique which is designed into a group architecture. To demonstrate the
efficiency of the method, a standard suite of single and multidimensional
optimization functions along with the energies and the geometric structures of
Lennard-Jones clusters are given as well as the application of the algorithm on
quantum circuit design problems. We show that as an improvement over previous
methods, the algorithm scales as N^2.5 for the Lennard-Jones clusters of
N-particles. In addition, an efficient circuit design is shown for two qubit
Grover search algorithm which is a quantum algorithm providing quadratic
speed-up over the classical counterpart
Particle In Cell Simulation of Combustion Synthesis of TiC Nanoparticles
A coupled continuum-discrete numerical model is presented to study the
synthesis of TiC nanosized aggregates during a self-propagating combustion
synthesis (SHS) process. The overall model describes the transient of the basic
mechanisms governing the SHS process in a two-dimensional micrometer size
geometry system. At each time step, the continuum (micrometer scale) model
computes the current temperature field according to the prescribed boundary
conditions. The overall system domain is discretized with a desired number of
uniform computational cells. Each cell contains a convenient number of
computation particles which represent the actual particles mixture. The
particle-in-cell (discrete) model maps the temperature field from the
(continuum) cells to the respective internal particles. Depending on the
temperature reached by the cell, the titanium particles may undergo a
solid-liquid transformation. If the distance between the carbon particle and
the liquid titanium particles is within a certain tolerance they will react and
a TiC particle will be formed in the cell. Accordingly, the molecular dynamic
method will update the location of all particles in the cell and the amount of
transformation heat accounted by the cell will be entered into the source term
of the (continuum) heat conduction equation. The new temperature distribution
will progress depending on the cells which will time-by-time undergo the
chemical reaction. As a demonstration of the effectiveness of the overall model
some paradigmatic examples are shown.Comment: submitted to Computer Physics Communication
A simple non-equilibrium, statistical-physics toy model of thin-film growth
We present a simple non-equilibrium model of mass condensation with
Lennard-Jones interactions between particles and the substrate. We show that
when some number of particles is deposited onto the surface and the system is
left to equilibrate, particles condense into an island if the density of
particles becomes higher than some critical density. We illustrate this with
numerically obtained phase diagrams for three-dimensional systems. We also
solve a two-dimensional counterpart of this model analytically and show that
not only the phase diagram but also the shape of the cross-sections of
three-dimensional condensates qualitatively matches the two-dimensional
predictions. Lastly, we show that when particles are being deposited with a
constant rate, the system has two phases: a single condensate for low
deposition rates, and multiple condensates for fast deposition. The behaviour
of our model is thus similar to that of thin film growth processes, and in
particular to Stranski-Krastanov growth.Comment: 26 pages, 16 figure
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