2,511 research outputs found
Stabilization of systems with asynchronous sensors and controllers
We study the stabilization of networked control systems with asynchronous
sensors and controllers. Offsets between the sensor and controller clocks are
unknown and modeled as parametric uncertainty. First we consider multi-input
linear systems and provide a sufficient condition for the existence of linear
time-invariant controllers that are capable of stabilizing the closed-loop
system for every clock offset in a given range of admissible values. For
first-order systems, we next obtain the maximum length of the offset range for
which the system can be stabilized by a single controller. Finally, this bound
is compared with the offset bounds that would be allowed if we restricted our
attention to static output feedback controllers.Comment: 32 pages, 6 figures. This paper was partially presented at the 2015
American Control Conference, July 1-3, 2015, the US
Dynamic SU(2) Lattice Gauge Theory at Finite Temperature
The dynamic relaxation process for the (2+1)--dimensional SU(2) lattice gauge
theory at critical temperature is investigated with Monte Carlo methods. The
critical initial increase of the Polyakov loop is observed. The dynamic
exponents and as well as the static critical exponent
are determined from the power law behaviour of the Polyakov loop, the
auto-correlation and the second moment at the early stage of the time
evolution. The results are well consistent and universal short-time scaling
behaviour of the dynamic system is confirmed. The values of the exponents show
that the dynamic SU(2) lattice gauge theory is in the same dynamic universality
class as the dynamic Ising model.Comment: 10 pages with 2 figure
A new approach to dynamic finite-size scaling
In this work we have considered the Taylor series expansion of the dynamic
scaling relation of the magnetization with respect to small initial
magnetization values in order to study the dynamic scaling behaviour of 2- and
3-dimensional Ising models. We have used the literature values of the critical
exponents and of the new dynamic exponent to observe the dynamic
finite-size scaling behaviour of the time evolution of the magnetization during
early stages of the Monte Carlo simulation. For 3-dimensional Ising Model we
have also presented that this method opens the possibility of calculating
and separately. Our results show good agreement with the literature
values. Measurements done on lattices with different sizes seem to give very
good scaling.Comment: Latex file with six figures. Accepted for publication in IJM
Management controls in automotive international joint ventures involving Chinese parent companies
Key findings:
• Flexibility in international joint ventures (JVS) is important and a shared but split
control style is recommended.
• Chinese partners used to have learning as their main objective in an IJV but this
has been replaced by profit, growth and market share.
• The most significant shifts in control between partners involve human resource
management and research and development.
• When foreign partners insist on adherence to their own management philosophy,
culture clashes occur.
• Negotiation is a part of daily life in the IJVs, and it occurs at both executive and
managerial levels, depending upon the significance of the item
Short-time critical dynamics and universality on a two-dimensional Triangular Lattice
Critical scaling and universality in short-time dynamics for spin models on a
two-dimensional triangular lattice are investigated by using Monte Carlo
simulation. Emphasis is placed on the dynamic evolution from fully ordered
initialstates to show that universal scaling exists already in the short-time
regime in form of power-law behavior of the magnetization and Binder cumulant.
The results measured for the dynamic and static critical exponents, ,
, and , confirm explicitly that the Potts models on the
triangular lattice and square lattice belong to the same universality class.
Our critical scaling analysis strongly suggests that the simulation for the
dynamic relaxation can be used to determine numerically the universality.Comment: LaTex, 11 pages and 10 figures, to be published in Physica
Dynamic Monte Carlo Study of the Two-Dimensional Quantum XY Model
We present a dynamic Monte Carlo study of the Kosterlitz-Thouless phase
transition for the spin-1/2 quantum XY model in two dimensions. The short-time
dynamic scaling behaviour is found and the dynamical exponent , and
the static exponent are determined at the transition temperature.Comment: 6 pages with 3 figure
Development and characterization of osteogenic cell sheets in an in vivo model
[Excerpt] Despite some successes in the tissue engineering field its evolution seems to be tampered by limitations such as cell sourcing and the lack of adequate scaffolds to support cell growth and differentiation.
The use of stem cells combined with cell sheet engineering technology seems a promising way to overcome these limitations. In this work bone marrow cells were flushed from 3 weeks old Wistar rat femurs and cultured in basal DMEM medium until subconfluence. Cells were then transferred to thermo-responsive dishes (3 x10⁵ cells/dish) and cultured for 3 weeks in osteogenic medium. [...]info:eu-repo/semantics/publishedVersio
Universal Short-time Behaviour of the Dynamic Fully Frustrated XY Model
With Monte Carlo methods we investigate the dynamic relaxation of the fully
frustrated XY model in two dimensions below or at the Kosterlitz-Thouless phase
transition temperature. Special attention is drawn to the sublattice structure
of the dynamic evolution. Short-time scaling behaviour is found and
universality is confirmed. The critical exponent is measured for
different temperature and with different algorithms.Comment: 18 pages, LaTeX, 8 ps-figure
Dynamics of ripple formation on silicon surfaces by ultrashort laser pulses in sub-ablation conditions
An investigation of ultrashort pulsed laser induced surface modification due
to conditions that result in a superheated melted liquid layer and material
evaporation are considered. To describe the surface modification occurring
after cooling and resolidification of the melted layer and understand the
underlying physical fundamental mechanisms, a unified model is presented to
account for crater and subwavelength ripple formation based on a synergy of
electron excitation and capillary waves solidification. The proposed
theoretical framework aims to address the laser-material interaction in
sub-ablation conditions and thus minimal mass removal in combination with a
hydrodynamics-based scenario of the crater creation and ripple formation
following surface irradiation with single and multiple pulses, respectively.
The development of the periodic structures is attributed to the interference of
the incident wave with a surface plasmon wave. Details of the surface
morphology attained are elaborated as a function of the imposed conditions and
results are tested against experimental data
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