1,726 research outputs found
Coarse Stability and Bifurcation Analysis Using Stochastic Simulators: Kinetic Monte Carlo Examples
We implement a computer-assisted approach that, under appropriate conditions,
allows the bifurcation analysis of the coarse dynamic behavior of microscopic
simulators without requiring the explicit derivation of closed macroscopic
equations for this behavior. The approach is inspired by the so-called
time-step per based numerical bifurcation theory. We illustrate the approach
through the computation of both stable and unstable coarsely invariant states
for Kinetic Monte Carlo models of three simple surface reaction schemes. We
quantify the linearized stability of these coarsely invariant states, perform
pseudo-arclength continuation, detect coarse limit point and coarse Hopf
bifurcations and construct two-parameter bifurcation diagrams.Comment: 26 pages, 5 figure
PID control system analysis and design
With its three-term functionality offering treatment of both transient and steady-state responses,
proportional-integral-derivative (PID) control provides a generic and efficient solution to realworld
control problems. The wide application of PID control has stimulated and sustained
research and development to "get the best out of PID", and "the search is on to find
the next key technology or methodology for PID tuning".
This article presents remedies for problems involving the integral and derivative terms. PID design objectives,
methods, and future directions are discussed. Subsequently, a computerized, simulation-based approach
is presented, together with illustrative design results for first-order, higher order, and nonlinear plants. Finally,
we discuss differences between academic research and industrial practice, so as to motivate new research
directions in PID control
Conedy: a scientific tool to investigate Complex Network Dynamics
We present Conedy, a performant scientific tool to numerically investigate
dynamics on complex networks. Conedy allows to create networks and provides
automatic code generation and compilation to ensure performant treatment of
arbitrary node dynamics. Conedy can be interfaced via an internal script
interpreter or via a Python module
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