M. Ahmadi - Academia.edu (original) (raw)
Papers by M. Ahmadi
Proceedings 7th International Conference on Signal Processing, 2004. Proceedings. ICSP '04. 2004., 2004
This paper presents a new method for applying a genetic algorithm (GA) in the design of high thro... more This paper presents a new method for applying a genetic algorithm (GA) in the design of high throughput digital filters using canonic signed digit (CSD) coefficients. The method employs a unique chromosome coding technique which overcomes the limitations previously encountered with this design technique. A design example demonstrates the new method's improved capabilities.
IEE Proceedings G (Electronic Circuits and Systems), 1981
An improved version of the Kaiser method for the design of nonrecursive 1-dimensional digital fil... more An improved version of the Kaiser method for the design of nonrecursive 1-dimensional digital filters, and a method for the design of recursive 1-dimensional digital filters due to Antoniou are applied to the design of 2-dimensional digital filters. Two methods are developed which can be used to design lowpass filters satisfying prescribed amplitude-response specifications. The two methods are easy to apply, and entail a minimal amount of computation.
The 2004 47th Midwest Symposium on Circuits and Systems, 2004. MWSCAS '04.
Document images, as a substitute of paper documents, have become the primary information medium i... more Document images, as a substitute of paper documents, have become the primary information medium in our society. This makes document image analysis an important area of research in image processing, pattern recognition and computer vision. The goal of our research is to ...
Indian Journal of Applied Research, 2011
Working in the field of Nano technology requires instruments that can visualize and manipulate na... more Working in the field of Nano technology requires instruments that can visualize and manipulate nano- structures. A Scanning Tunneling Microscope (STM) can analyze a sample surface at nano-scale and pro- duce its topographical image. The design of the STM is based on Screw-Lever Motion demagnifier described in the literature. The scanner uses three orthogonal stack piezo cubes joined together with a metallic tripod. Images of highly oriented pyrolytic graphite have been obtained in air with constant current mode. The atomic resolution images ob- tained clearly show the hexagonal lattice of graphite. In this article, we describe design and construction of a robust low cost computer controlled constant current imag- ing STM. We also explain a simple method used to produce probes (tips) for the microscope. Major sections such as vibration isolation system, scan unit, analogue and computer control electronics have all been described. Data acquisi- tion system designed and built is very low cost and easily available to everyone. The software that controls the system was written in Delphi language. To achieve cost effectiveness, expensive components and royalty controlled software have been avoided. The STM designed is therefore low cost, efficient and suitable for students, researchers and low budget institutions.
Russian Journal of Inorganic Chemistry, 2012
ABSTRACT
Journal of Polymer Research, 2012
ABSTRACT In this study, unsaturated polyester (UP) resin was reinforced by using an organically-m... more ABSTRACT In this study, unsaturated polyester (UP) resin was reinforced by using an organically-modified montmorillonite (OMMT) and toughened with poly(n-butyl acrylate)/poly(vinyl acetate-co-methyl methacrylate) core-shell rubber (CSR) particles. The effects of OMMT and CSR levels on the fracture behavior and tensile properties of UP were investigated. The results showed that the incorporation of OMMT of up to 3 wt.% increased the UP fracture toughness (KIC) to some extent, while further addition caused the fracture toughness to reach a constant level. Furthermore, the dispersion state of OMMT platelets and CSR particles inside the UP matrix was studied by means of transmission electron microscopy (TEM). TEM micrographs showed a good dispersion of organoclay tactoids with an intercalated structure or partial exfoliation for the UP reinforced by 1 and 3 wt.% OMMT. On the other hand, addition of 5 and 10 wt.% CSR particles to the UP increased the fracture toughness much more than the OMMT. Locally clustered but globally good CSR particle dispersion inside the UP matrix was observed in toughened UP specimens. Interestingly, a synergistic effect in fracture toughness was only observed for the UP hybrid composite containing 1 wt.% OMMT and 10 wt.% CSR particles, when compared with other reinforced, toughened, and hybrid specimens. In this case, the OMMT platelets were found to act as bridges between the small rubber-particle agglomerates, which may cause alternating clay debonding/CSR particle cavitation and improve plastic deformation inside the UP matrix. The incorporation of OMMT increased Young’s modulus and also decreased the tensile strength of the neat and CSR-toughened UP specimens with increasing the amount of OMMT.
IEE Proceedings - Circuits, Devices and Systems, 2000
A generalised VLSI circuit realisation for a nonlinear active resistor-type neuron is proposed th... more A generalised VLSI circuit realisation for a nonlinear active resistor-type neuron is proposed that implements a saturating sigmoidal-like function by combining the nonlinear characteristics of NMOS and PMOS transistors. The circuit design is based on using a parameter sensitivity analysis to develop a robust design that will be relatively insensitive to process-parameter variations over the area of the die. The nonlinear resistor has been integrated into a module which realises a programmable digital synaptic weight capability. A neuron is effectively formed from the parallel interconnection that takes place as multiplier outputs are connected to create an input node to the resultant distributed neuron. Designs in 0.35 and 0.8 µm processes are compared with a conservative 1.2 µm CMOS implementation.
Polyhedron, 2013
This article appeared in a journal published by Elsevier. The attached copy is furnished to the a... more This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues. Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier's archiving and manuscript policies are encouraged to visit: http://www.elsevier.com/authorsrights Author's personal copy Synthesis, spectroscopy, DFT and crystal structure investigations of 3-methoxy-2-hydroxybenzaldehyde S-ethylisothiosemicarbazone and its Ni(II) and Mo(VI) complexes
Proceedings 7th International Conference on Signal Processing, 2004. Proceedings. ICSP '04. 2004., 2004
This paper presents a new method for applying a genetic algorithm (GA) in the design of high thro... more This paper presents a new method for applying a genetic algorithm (GA) in the design of high throughput digital filters using canonic signed digit (CSD) coefficients. The method employs a unique chromosome coding technique which overcomes the limitations previously encountered with this design technique. A design example demonstrates the new method's improved capabilities.
IEE Proceedings G (Electronic Circuits and Systems), 1981
An improved version of the Kaiser method for the design of nonrecursive 1-dimensional digital fil... more An improved version of the Kaiser method for the design of nonrecursive 1-dimensional digital filters, and a method for the design of recursive 1-dimensional digital filters due to Antoniou are applied to the design of 2-dimensional digital filters. Two methods are developed which can be used to design lowpass filters satisfying prescribed amplitude-response specifications. The two methods are easy to apply, and entail a minimal amount of computation.
The 2004 47th Midwest Symposium on Circuits and Systems, 2004. MWSCAS '04.
Document images, as a substitute of paper documents, have become the primary information medium i... more Document images, as a substitute of paper documents, have become the primary information medium in our society. This makes document image analysis an important area of research in image processing, pattern recognition and computer vision. The goal of our research is to ...
Indian Journal of Applied Research, 2011
Working in the field of Nano technology requires instruments that can visualize and manipulate na... more Working in the field of Nano technology requires instruments that can visualize and manipulate nano- structures. A Scanning Tunneling Microscope (STM) can analyze a sample surface at nano-scale and pro- duce its topographical image. The design of the STM is based on Screw-Lever Motion demagnifier described in the literature. The scanner uses three orthogonal stack piezo cubes joined together with a metallic tripod. Images of highly oriented pyrolytic graphite have been obtained in air with constant current mode. The atomic resolution images ob- tained clearly show the hexagonal lattice of graphite. In this article, we describe design and construction of a robust low cost computer controlled constant current imag- ing STM. We also explain a simple method used to produce probes (tips) for the microscope. Major sections such as vibration isolation system, scan unit, analogue and computer control electronics have all been described. Data acquisi- tion system designed and built is very low cost and easily available to everyone. The software that controls the system was written in Delphi language. To achieve cost effectiveness, expensive components and royalty controlled software have been avoided. The STM designed is therefore low cost, efficient and suitable for students, researchers and low budget institutions.
Russian Journal of Inorganic Chemistry, 2012
ABSTRACT
Journal of Polymer Research, 2012
ABSTRACT In this study, unsaturated polyester (UP) resin was reinforced by using an organically-m... more ABSTRACT In this study, unsaturated polyester (UP) resin was reinforced by using an organically-modified montmorillonite (OMMT) and toughened with poly(n-butyl acrylate)/poly(vinyl acetate-co-methyl methacrylate) core-shell rubber (CSR) particles. The effects of OMMT and CSR levels on the fracture behavior and tensile properties of UP were investigated. The results showed that the incorporation of OMMT of up to 3 wt.% increased the UP fracture toughness (KIC) to some extent, while further addition caused the fracture toughness to reach a constant level. Furthermore, the dispersion state of OMMT platelets and CSR particles inside the UP matrix was studied by means of transmission electron microscopy (TEM). TEM micrographs showed a good dispersion of organoclay tactoids with an intercalated structure or partial exfoliation for the UP reinforced by 1 and 3 wt.% OMMT. On the other hand, addition of 5 and 10 wt.% CSR particles to the UP increased the fracture toughness much more than the OMMT. Locally clustered but globally good CSR particle dispersion inside the UP matrix was observed in toughened UP specimens. Interestingly, a synergistic effect in fracture toughness was only observed for the UP hybrid composite containing 1 wt.% OMMT and 10 wt.% CSR particles, when compared with other reinforced, toughened, and hybrid specimens. In this case, the OMMT platelets were found to act as bridges between the small rubber-particle agglomerates, which may cause alternating clay debonding/CSR particle cavitation and improve plastic deformation inside the UP matrix. The incorporation of OMMT increased Young’s modulus and also decreased the tensile strength of the neat and CSR-toughened UP specimens with increasing the amount of OMMT.
IEE Proceedings - Circuits, Devices and Systems, 2000
A generalised VLSI circuit realisation for a nonlinear active resistor-type neuron is proposed th... more A generalised VLSI circuit realisation for a nonlinear active resistor-type neuron is proposed that implements a saturating sigmoidal-like function by combining the nonlinear characteristics of NMOS and PMOS transistors. The circuit design is based on using a parameter sensitivity analysis to develop a robust design that will be relatively insensitive to process-parameter variations over the area of the die. The nonlinear resistor has been integrated into a module which realises a programmable digital synaptic weight capability. A neuron is effectively formed from the parallel interconnection that takes place as multiplier outputs are connected to create an input node to the resultant distributed neuron. Designs in 0.35 and 0.8 µm processes are compared with a conservative 1.2 µm CMOS implementation.
Polyhedron, 2013
This article appeared in a journal published by Elsevier. The attached copy is furnished to the a... more This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues. Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier's archiving and manuscript policies are encouraged to visit: http://www.elsevier.com/authorsrights Author's personal copy Synthesis, spectroscopy, DFT and crystal structure investigations of 3-methoxy-2-hydroxybenzaldehyde S-ethylisothiosemicarbazone and its Ni(II) and Mo(VI) complexes