The idea of Evolutionary Optimization Algorithms (EA) is inspired by
the evolution processes that take place in
nature, where sucessfull species must
adapt continuously to the changing
enviroment by creating new individuals and
by selectio of the fittest. This natural
optimization technique can easily be
transfered to mathematical optimization
problems. Theobjective function F on a
search space S can be interpreted as the
environment and each vector v is a
possible individuum in this
environment. The fitness of these
mathematical individuals is given by the
objective function F(v). The EA searches
for the optimal solution, by starting with
an initial set of vectors called
"population". In each following iteration
(generation) a new set of vectors is
created from the old population by
modifying the fittest of the old
vectors. For the new population of the
next generation the fittest among the
newly created and old vectors are
selected.
I started working with Evolutionary Algorithms during the diploma
thesis for my stdy of buissnes and
administration (Betriebswirtschaftslehre)
at the comprehensive Unniversity in
Hagen. Here I developed an object oriented
C++-libary for EAs.
Computer simulation is an important tool in modern product
development. New prototypes of products are designed, improved
and tested using computers before a first real prototype is
build. In this process different geometries, materials
and process parameters are changed by hand until a
sufficient solution was found. DesParO provides the
possibility to optimise these design parameters using the computer.
DesParO is an optimisation toolbox especially design for industrial
simulation. The toolbox contains a collection of efficient algorthims
for the computer based optimisation and can easily be adopted to any
industrial simulation code. Consulting by the GMD institute SCAI ensures an
efficient use of the toolbox. DesParO was especially designed for
computational expensive simulation codes and supports parallel computation.
Evolutionary Optimization
Design Parameter Optimization (DesParO)
DesParO-Homepage
Investigation of hot electrons with the aid of Evolutionary
Algorithms
By means of Evolutionary Algorithms, a class of robust optimization techniques
used in Operations Research, it is possible to backward calculate electron distributions from measurement results.
HgCdTe
The observation of EEW in HgCdTe makes it possible to investigate the electric
field distribution of electrons in this material for
T<30 K. EAs revealed that in order to achieve energy balance in
moderate electric fields, the electron distribution differs slightly from a
Fermi distribution.
-Genetic algorithms: A new approach to energy balance equations,
J. Jakumeit, Appl. Phys. Lett. 66, 1812, 1995Silizium (Si-MOSFETs)
In collaboration with the group of
Prof. K. Hess and
Prof. U. Ravaioli
at the
Beckman Institut of the
University of Illinois
(
National Center for Computational Electronics) the EAs were used to
investigate the distribution of hot electrons in silicon.
The object was to calculate sustrate and gate currents in Si-MOSFETs.
With help of a physical mutation operator, which is based on the Monte-Carlo
technique, results comparable to full band calculations could be
obtained.
-Calculation of hot electron distributions in silicon by means of
an Evolutionary Algorithm,
J. Jakumeit, U.~Ravaioli, K.~Hess, J. Appl. Phys., Okt. 96,
(postscript, gezipt, 153kb)
-Evolutionary algorithms for the calculation
of electron distributions in Si-MOSFETs, J, Jakumeit, Proceedings of the
IV. International Conference on
Parallel Problem Solving from Nature (Berlin 1996), Lecture Notes in Computer
Science 1141, Springer Verlag, 1996, S. 819
(postscript, gezipt, 186kb)