Documents - Collection of selected
documents by Igor Grešovnik
This page
contains a number of documents that are related to my work or
personal interest and which I wanted to make easily accessible to
others. Send comments and suggestions for improvements to gresovnik
(at) gmail.com (without spaces and underscores!).
Papers
The Use of Moving Least Squares for a
Smooth Approximation of Sampled Data ("Uporaba metode
premičnih najmanjših kvadratov za gladko aproksimacijo vzorčenih
podatkov."). Journal of Mechanical Engineering 53(2007)9, 582-598
(UDK 517.518.8:519.243, 2007), original available at sv-jme.eu
(=>),
by Igor Grešovnik.
Shape
optimization of two-phase inelastic material with microstructure.
Engineering Computations, Vol. 22 Iss: 5/6, pp.605 - 645, (ISSN:
0264-4401, DOI: 10.1108/02644400510603032), 2005, original available
at emeraldinsight.com
(==>,
==>),
© Emerald Group Publishing Limited, by Adnan Ibrahimbegovic, Igor
Grešovnik, Damijan Markovic, Sergiy Melnyk, and Tomaž Rodič. Won
Emerald Award of Excellence for outstanding paper in 2006.
A
computer system for solving inverse and optimization problems.
Engineering Computations, Vol. 15 Iss: 7, pp.893 - 907, 1998 (ISSN:
0264-4401, DOI: 10.1108/02644409810236902), original available at emeraldinsight.com
(==>),
© Emerald Group Publishing Limited, by Tomaž Rodič and Igor
Grešovnik.
Optimal design of preform geometry
and tribological conditions in can forming.
Engineering Computations, Vol. 22 Iss: 8, pp.972 - 979, 2005 (ISSN:
0264-4401, DOI: 10.1108/02644400510626514), original available at emeraldinsight.com
(==>),
© Emerald Group Publishing Limited, by Tomaž Rodic, Domen Cukjati,
Igor Grešovnik.
Reducing Localisation Induced Defects
at Blow Forming in Terms of Optimal Shape Design,
VIII Conference on Computational Pasticity, COMPLAS VIII, Barcelona,
2005, original available at COMPLAS
205 (==>),
© CIMNE, Barcelona, by Igor Grešovnik, Stanislav Hartman and Tomaž
Rodič.
A
Software Framework for Optimization of Process Parameters in
Material Production, Applied Mechanics and Materials (Volumes
101 - 102 - Advances in Engineering Design and Optimization, by Di
Zheng, Yiqiang Wang, Yi-Min Deng, Aibing Yu and Weihua Li
(editors)), pp. 838-841, original available at scientific.net,
by Igor Grešovnik, Tadej Kodelja, Robert Vertnik, and Božidar
Šarler.
Influence of transient response of
platinum electrode on neural signals during stimulation of
isolated swinish left vagus nerve ("Vpliv prehodnega
značaja platinaste elektrode na živčni signal med stimulacijo
izoliranega živca vagusa svinje"). Materials and technology 46
(2012) 2, 131–137, UDK 621.357:591.18, ISSN 1580-2949, original
available at mit.imt.si
(==>,
==>), by
Polona Pečlin, Franci Vode, Andraž Mehle, Igor Grešovnik, and Janez
Rozman.
Back-analysis
of elastic properties of the ground using data from a large scale
plate load test. The 42nd U.S. Rock Mechanics Symposium
(USRMS), June 29 - July 2, 2008 , San Francisco, CA, original
available at online.tugraz.at
(==>),
by N. Radoncic, K. Grossauer, K, W. Schubert, I. Grešovnik, H-J.
Gober.
Optimization Techniques for Inverse
Identification of Geomechanical Parameters. The 5th
European Congress on Computational Methods in Sciences and
Engineering (Eccomas 2008), Venice, Italy, original available at congress.cimne.com/eccomas
(==>),
by by Igor Grešovnik, Nedim Radončić, Karl Grossauer and Tomaž
Rodič.
Unpublished
Numerical Support for Optimal Process
Design with Case Study: Prestressing of Cold Forging Dies.
Igor Grešovnik, 2007 (.).
Software Framework for Application of
Automatic Optimization Techniques in Metal Forming.
Igor Grešovnik, 2005.
Inverse Estimation of Exponential and
Piece-wise Linear Approximation of the Hardening Curve from the
Tension Test. I. Grešovnik, T. Rodič & D.R.J.
Owen, 1995. Written on basis of work done for graduate thesis
(finished in 1994).
Reports and e-books
Simplex algorithms for nonlinear
constraint optimization problems. This documents
contains description of a set fo modified Nelder-Mead simplex
algorithms that can be used for constraint nonlinear optimization.
These algorithms can be advantageously used for optimization
when gradients of the objective and constraint functions are not
available and where these functions are not smooth.
Praktične metode optimizacije
("Optimization Methods in Practice" - in Slovene language). This
electronic book was predominantly written to acquaint my colleagues
at work and other interesting people with some basic optimization
methodologies. I have noticed that people working in technical
fields usually have very little knowledge on these topics, and
because of this often make wrong decisions about how to direct
development when there is also a need or possibility for application
of optimization methods involved. I order to mitigate the problem, I
have written this script where one can quickly grasp some basics
about optimization methods that work in practice.
Matrix Decompositions with
Implementation Remarks (for use with nonlinear optimization
software). This e-book contains a short overview of matrix
decompositions with some implementation remarks. The text is adapted
to application of matrix decompositions and linear equation solving
in the field of nonlinear optimization.
Difuzija vodika iz okroglih in
kvadratnih profilov – pregled glavnih rezultatov / Hydrogen
Diffusion from round and square profiles - overview of results
(in Slovene language). Report of calculation of Hydrogen diffusion
from steel bars and other profiles. Coefficients for numerical model
of hydrogen diffusion are calculated by inverse method. Heating
times necessary for sufficient removal of hydrogen are calculated by
solution of the appropriately defined optimization problems.
Inverse Identification of Parameters
of Numerical Models. Technical report on inverse
identification of parameters by using convential optimization
techniques.
Linear Approximation with
Regularization and Moving Least Squares. Electronic
book with detailed treatment of approximation methods used in
various optimization algorithms based on sequential approximations
(many of them implemented in the IOptLib
library).
Sound
Level Meter - Development of Signal Processing Algorithms.
Expertise on development of algorithms for digital signal processing
used in a high precision sound level meter.
Manual:
Measurement of Sound Level. User manual for measurement
of sound level by a digital sound level meter.
Manuals
IOptLib User's Manual. A
manual for using the Investigative
optimization
library.
Inverse Manuals. A series
of manuals for using the optimization shell Inverse.
Out of use:
Quick Overview of the SGS (Simple
Graphic System). A 3D graphic system that was used in Inverse.
Sendigence User's Manual.
Courses
I have organized a number of courses,
for some of which documentation is available on the internet.
Numerical
Methods in Physics.
C# for
Scientists and Engineers.
Igor Grešovnik: Numerične
metode v fiziki - izbor končnih nalog (in Slovene; HTML
version). This document contains a selection of tasks that
student can choose to defend as coursework in the final exam.
Students solve the selected physical problem programmatically (by
using the appropriate numerical techniques), create a detailed
report (that must also contain derivation of formulas, tests of
correctness and accuracy), and defend the work where hood
understanding of the problem is also demonstrated by solving
additional sub-tasks.
Igor Grešovnik: Numerične
metode v fiziki - domače naloge (in Slovene; HTML
version). This document contains small problems that students
have to solve programmatically during the course.
Theses
Igor Grešovnik, A General Purpose Computational Shell
for Solving Inverse and Optimisation Problems - Applications to
Metal Forming Processes, Ph. D. thesis, University of
Wales Swansea, U.K., 2000.
Alternative site:
Igor Grešovnik, Inverzna numerična analiza
deformabilnih teles, graduate thesis, University of
Ljubljana, Slovenia, 1994.
Projects
ENLUB:
C3M final report for last 12 months.
This document contains a brief description of how optimization
software Inverse is linked with
simulation software Elfen with some
properties of Inverse
listed, and of inverse identification of contact parameters from
measurements performed on laboratory tests such as the strip
reduction test. What is important is treatment of noise that affects minimization
algorithms used in inverse identification. It is shown how even for a very simple tests, response
obtained by the finite element analysis can contain significant
amount of numerical noise, which is restrictive for
accurate and efficient application of inverse procedures. Smoothing
procedures that aim at elimination of the noise are introduced, and
it is indicated that robust minimization procedures more resistant
to numerical noise in the response functions need to be constructed.
Remark: through my work I have many times
experienced a tendency to ignore or deny the problem of noise in
the results obtained by the FEM analysis. Awareness of the
problems related to this, especially in inverse identification of
parameters (and in all kinds of parametric optimization in which
complex numerical models are used) is however crucial for success
of the applied procedures, especially when a real world industrial
problems are solved. This document is partially intended to raise
the awareness in this area.
TUNCONSTRUCT:
Deliverable D1.3.2.1 - Specifications for software to determine sensitivities
for optimization of the design of underground construction as
part of IOPT. This documents contains specifications
for the software for solving
optimization problems and inverse identification of material and
other parameters from laboratory tests or in situ
measurements. A special emphasis is put on using the algorithms in conjunction
with simulation software and in interfacing the optimization
related modules. Beside that, a general solution scheme is
described, short notes on differentiation of numerical models are
included, envisaged development of approximation based optimization
algorithms are pointed at (with emphasis on the intended ability of
such algorithms to handle noise and with illustrarions that provide
obvious and instructive illustration of why derivatives for
practical purposes can not be calculated by the finite difference
mthods), and the meaning of the whole lot of talking is less
abstractly shown on an imaginary demonstrative example. Almost all
of the document (except the actual precise specifications for
linking of optimization modules with other software) is intended
just to make things more familiar to others (especially partners in
the project).
“What Is” Reference List of
Optimization Related Expressions for TUNCONSTRUCT (MS Word
document). This document si put there to explain some terms commonly
used in communication about optimization related tasks.
Links to other documents
Igor Grešovnik, A General Purpose Computational Shell
for Solving Inverse and Optimisation Problems - Applications to
Metal Forming Processes, Ph. D. thesis, University of
Wales Swansea, U.K., 2000.
Documents from my work at
COBIK.
Partial list of reports and
papers - COBIK.
A collection of useful optimization related links.
Inverse on-line documentation with manuals.
Investigative
optimization library (IOptLib) and related
documents.
Investigative Generic
Library (IGLib) and related
documents.
External links
Igor Grešovnik: Optimization of
Fatigue Resistance of Cold Forging Tools by Considering Damage
Mechanisms at Micro Scale, (orig.,
arch.-
prop.,
prog.,
wg04,
final,
eu) COST 526
final report.
(Back to Igor's page)