In this work, we address a Demand Responsive Transport System capable of managing incoming transport demand using a solution architecture based on a two- stage algorithm to solve a Dial-a-Ride Problem instance. In the first stage, a constructive heuristic algorithm quickly provides a feasible solution to accept the incoming demand. The algorithm in the second stage is a specialized Hybrid Genetic Algorithm that attempts to improve the solution evaluated at the first stage by using the time between two consecutive transportation events.
Transportation
Heuristics
Genetic algorithms
Routing algorithms
Decision support systems
We prove the existence of a traveling wave solution u of the harmonic heat flow in an infinitely long cylinder of radius R, which connects two locally stable and axially symmetric steady states at + and - infinity infinity. Here u is a director field, with values in the unit sphere. The traveling wave has a singular point on the cylinder axis. As R goes to infinity we obtain a traveling wave defined in all space.
In this paper we deal with the numerical approximation of
integro-differential equations arising in financial applications
in which jump processes act as the underlying stochastic processes.
Our aim is to find finite differences schemes which are high-order accurate
for large time simulations.
Therefore, we study the asymptotic time behavior of such equations
and we define as {\it asymptotic high-order schemes} those schemes
that are consistent
with this behavior.
Numerical tests are presented to investigate the
efficiency and the accuracy of such approximations.
We consider a mathematical model for fluid-dynamic flows on networks
which is based on conservation laws. Road networks are considered as
graphs composed by arcs that meet at some junctions.
The crucial point is represented by junctions, where interactions
occurr and the problem is underdetermined.
The approximation of scalar conservation laws along arcs is carried out by using
conservative methods, such as the classical Godunov scheme and the more recent
discrete velocities kinetic schemes with the use of suitable
boundary conditions at junctions.
Riemann problems are solved by means of a simulation algorithm which
proceeds processing each junction. We present the algorithm and its
application to some simple test cases and to portions of urban network.
