Welcome to my Official Webpage
Amir Hossein Haji
Ph.D. of Mechanical Eng. in Dynamical Systems and Control
Mechanical Engineering Dept. Shiraz University
Education:
Ph.D. in Dynamical Systems and Control, Mechanical Engineering Department, Shiraz University, Shiraz, Iran, September 2010.
Master of Science in Energy Conversion, Mechanical Engineering Department, Shiraz University, Shiraz, Iran, January 2004.
Bachelor of Science in Solid Design, Mechanical Engineering Department, Shiraz University, Shiraz, Iran, September 2001.
Current Research Interest:
Pattern Formation
Pattern formation refers to the representation (pattern) of some global behavior in a group of particles (subsystems) interconnecting and evolving together. It comprises numerous examples from different systems such as the rolls of convective air above a heater (upward warm, downward cool) or the biological patterns on the animals’ coating.
Recent developments in non linear systems theory along with some relevant experimental results have clarified the existence of universal patterns for systems regardless of their exact local dynamics. The symmetry of the system whether in the boundary conditions or in the domain has been used in modern approach as a local global property which addresses this universality.
In my Ph.D. thesis, I have revised the role of symmetry as to provide the space with a structure wherein the form of the point functions is restricted and can be substituted by some invariant or conservative form. The symmetries are then represented directly through a sequence. This sequential formalism is applied to abstract geometric cases. Then with the aim of controlling a pattern formation system without any change in the physical field, I have tried to involve the manifolds in patter formation. The concept of manifold is introduced as a geometric representation of symmetry that can be used to produce and control some desired patterns.
I am now interested in practical applications of pattern formation and nonlinear dynamical systems modeling to the analysis and design of mechanical systems. Also I am interested in biological examples of sequential pattern formation and especially those which also comprise mechanical aspects. The Murray’s mechanochemical model for morphogenesis seems the best to date (Murray, J. D., Mathematical Biology, vol.2; spatial models and biomedical applications, 3rd ed., Springer, New York, 2003)
Previous Research Interest:
Chaos Theory
In recent decades the chaos theory approach to various phenomena has developed new insights in our realization of nature as well as in application fields.
In my M.Sc. project the attractors of engine speed and cylinder pressure of an internal combustion engine are reconstructed using embedding technique which is one of the main contributions of the chaos theory to the application fields. The reconstruction of these attractors besides providing the ability for prediction (which is accomplished in this project) and control of some features of cyclic variations can also manifest complexities and ability of the chaos theory to describe a real phenomenon.
The results include some applicable as well as some theoretical aspects. Applicable outcomes like efficacy of Locally Constant Models in prediction of the Top Dead Center (TDC) and TDC pressure time series and theoretical results such as discussion about type of the route to Chaos based on the results of auto - mutual information function and Lyapunov exponents, consistency between low level uncertainty and relatively small Embedding dimensions, and effect of data lengths and attractor dimensions on reconstruction are remarkable.
Teaching Experiences:
Teacher Assistant for the M.Sc. course of Advanced Mathematics 1 (Linear Algebra), Mechanical Engineering Department, Shiraz University, Shiraz, Iran, October 2005 to January 2006.
Strength of Materials Lab. Instructor, Mechanical Engineering Department, Shiraz University, Shiraz, Iran January 2005 to June 2007
Math Olympiads Teacher at NODET high school, September 2002 to June 2003.
Honors:
TOEFL(2005): Total 570, TWE 5
Publications:
A. H. Haji, M. Mahzoon, S. Javadpour, “Pattern formation and geometry of
the manifold”, Commun. Nonlinear Sci. Numer. Simulat, 16, 2011, 1424 – 1432,
Elsevier
doi:10.1016/j.cnsns.2010.06.019
A. H. Haji, “Sequence, symmetry and pattern formation”, Mathematical
and Computer Modelling, 52, 2010, 1639 – 1643, Elsevier
A. H. Haji, M. Mahzoon, H. Emdad,
"Reconstruction and Prediction of The In – Cylinder Pressure Attractor of an
Internal Combustion Engine Using Locally – Constant Models",
Nonlinear Dynamics, 48 Number 4, 2007, 437 - 447, Springer
A. H. Haji, M. Mahzoon, H. Emdad, "Evidence of Quasi – Periodic Behavior through Combined Mutual Information – Lyapunov Exponent Approach Applied to an Internal Combustion Engine",
The Internationnal Journal of Applied Mechanics and Engineering, IJAME 12/2,
A. H. Haji, M. Eghtesad, R. Hosseinie,
"Modeling and Control of a 3DOF Monoped Robot", The 14th ISME Conference,
May 2006, Download
S. A. Zareiyan Jahromi, A.H. Haji, M. Mahzoon,
"Nonlinear Dynamics and Chaos Control of a Physical Pendulum with a Rotating Mass",
The 13th ISME Conference, May 2005, Download
Personal Information:
Family Name: Haji
Name: Amir Hossein
Nationality: Iranian
Email: amir.hossein.haji@gmail.com, haji@shirazu.ac.ir
Phone: +98-711-6231776
Address : No. 31, 22/5, Dr. Hessabi Blvd., Shiraz, Iran
Postal Code : 71967-64178