Ali Nazari - Academia.edu (original) (raw)
Papers by Ali Nazari
RSC Adv., 2015
Boroaluminosilicate geopolymers from a fly-ash source have a variety of microstructures. This may... more Boroaluminosilicate geopolymers from a fly-ash source have a variety of microstructures. This may be due to different mechanisms of geopolymerization.
SN Computer Science
Deep learning has recently gained remarkable results in action recognition. In this paper, an arc... more Deep learning has recently gained remarkable results in action recognition. In this paper, an architecture is proposed for action recognition, including ResNet feature extractor, Conv-Attention-LSTM, BiLSTM, and fully connected layers. Furthermore, a sparse layer after each LSTM layer is added to overcome overfitting. In addition to RGB images, optical flow is also used to incorporate motion information into our architecture. Due to similarities of consecutive frames, video sequences are divided into equal parts. Frames of successive parts are used as consecutive frames to obtain the flow. Furthermore, to find the significant regions, the convolutional attention network is applied. The proposed method is evaluated using two popular datasets, UCF-101, and HMDB-51 and its accuracy for these datasets is 95.24 and 71.62, respectively. Overfitting is reduced due to using a sparse layer instead of a dropout based on the results achieved. Moreover, a deep LSTM network leads to a higher recognition rate than one-layer LSTM.
Quarterly Journal of Economic Research and Policies
Materials
Currently, there are a very limited number of studies on the effect of admixtures on properties o... more Currently, there are a very limited number of studies on the effect of admixtures on properties of ‘one-part’ geopolymers. This paper reports the effects of different superplasticizers and retarders on fresh and hardened properties of one-part fly ash-slag blended geopolymers made by different solid activators. Two different grades of sodium silicate, namely anhydrous sodium metasilicate powder (nSiO2/nNa2O = 0.9) and GD Grade sodium silicate powder (nSiO2/nNa2O = 2.0) were used as the solid activators. Five different commercially available superplasticizers, including three modified polycarboxylate-based superplasticizers (denoted as PC1, PC2, and PC3) and two naphthalene-based superplasticizers (denoted as N1 and N2), as well as three different retarders, including sucrose, anhydrous borax and a commercially available retarder, were investigated. Workability, setting time and compressive strength of the mixtures without and with addition of each ‘individual’ admixture were measure...
International Journal of Damage Mechanics
ABSTRACT
International Journal of Damage Mechanics
ABSTRACT In the present work, compressive strength of ash-based geopolymers with different mixtur... more ABSTRACT In the present work, compressive strength of ash-based geopolymers with different mixtures of % rice husk ash, fly ash, nano alumina and nano silica has been predicted by fuzzy logic. The alkali activating was done by a mixture of sodium hydroxide and sodium silicate solution. It was found that oven curing temperature and sodium hydroxide concentration together with SiO2 nanoparticles has the main effects on compressive strength of the specimens. The fuzzy logic model was constructed by 12 input parameters including the water curing time, the rice husk ash content, the fly ash content, the water glass content, sodium hydroxide content, the water content, the aggregate content, SiO2 nanoparticles content, Al2O3 nanoparticles content, oven curing temperature, oven curing time and test trial number. The value for the output layer was the compressive strength. According to the input parameters in fuzzy model, the input data were trained, validated and tested. The results indicate that fuzzy model is a powerful tool for predicting the effect of nanoparticles on compressive strength of the geopolymers in the considered range.
International Journal of Damage Mechanics
Abstract Mechanical properties of concrete specimens containing CuO nanoparticles which were cure... more Abstract Mechanical properties of concrete specimens containing CuO nanoparticles which were cured in saturated limewater have been optimized. CuO nanoparticles were partially added to concrete as nano-fillers. The specimens were cured in water and saturated ...
Energy and Buildings, 2011
ABSTRACT
Corr, Oct 7, 2010
A new lower bound for the average probability or error for a two-user discrete memoryless (DM) mu... more A new lower bound for the average probability or error for a two-user discrete memoryless (DM) multiple-access channel (MAC) is derived. This bound has a structure very similar to the well-known sphere packing packing bound derived by Haroutunian. However, since explicitly imposes independence of the users' input distributions (conditioned on the time-sharing auxiliary variable) results in a tighter sphere-packing exponent in comparison to Haroutunian's. Also, the relationship between average and maximal error probabilities is studied. Finally, by using a known sphere packing bound on the maximal probability of error, a lower bound on the average error probability is derived.
ABSTRACT BACKGROUND AND OBJECTIVE: Pain is the most frequent symptom in different diseases. In mo... more ABSTRACT BACKGROUND AND OBJECTIVE: Pain is the most frequent symptom in different diseases. In modern medicine, there are two main categories of analgesics: opioids and non-steroidal anti-inflammatory drugs (NSAIDs). Given the importance of medicinal plants in the treatment of different diseases, this study aimed to compare the analgesic effects of the alcoholic extract of Teucrium with morphine and aspirin. METHODS: In this experimental study, 36 Wistar rats were randomly divided into six groups of 6. The negative control group received normal saline (5 ml/kg), two positive control groups received morphine 2.5 mg/kg and aspirin 300 mg/kg, and three treatment groups received hydro-alcoholic extract of Teucrium (100, 200 and 400 mg/kg) intraperitoneally in single doses. Half an hour after the intraperitoneal injection of the extract, 50 microlitres of 2.5% formalin was injected subcutaneously into the right paw of the rats, and the analgesic effects were compared using the formalin t...
Viral Nervous Necrosis (VNN) is a worldwide disease affecting several species of cultured marine ... more Viral Nervous Necrosis (VNN) is a worldwide disease affecting several species of cultured marine fish. For the past two decades, betanodavirus infections that cause Viral Nervous Necrosis (VNN) have emerged as major constraints on the culture and sea ranching of marine fish in almost all parts of the world. More than forty species mainly of marine origin have been so far affected and this number is likely to rise in future following the introduction of new species and the increase of aquaculture trade.
Journal of Materials in Civil Engineering, 2015
AbstractA hybrid adaptive neuro-fuzzy interfacial systems–imperialist competitive algorithm (ANFI... more AbstractA hybrid adaptive neuro-fuzzy interfacial systems–imperialist competitive algorithm (ANFIS-ICA) was presented to determine the effect of concentration of alkali solution, alkali binder to alkali solution weight ratio, alkali activator to ordinary portland cement (OPC) weight ratio, oven curing temperature, and age of curing on the compressive strength of OPC-based geopolymers. Optimization of the type and number of membership functions was carried out by ICA while the training, testin,g and validating of the collected data sets was conducted by ANFIS. The obtained results indicated that the proposed ANFIS-ICA model is capable to predict the compressive strength of geopolymeric specimens well and suitably determine the effect of each parameter on this property. A parametric study is presented to show the effect of each parameter predicted by the model on compressive strength of the specimens.
International Journal of Damage Mechanics, 2011
In this study, tensile strength of gypsum-based composite with aluminum fibers up to 15 vol.% was... more In this study, tensile strength of gypsum-based composite with aluminum fibers up to 15 vol.% was studied. To increase the interfacial bond strength between fibers and matrix, aluminum fibers were anodized under different conditions. Single fiber pull-out tests were carried out to investigate the bond strength. The interface was examined by scanning electron microscope. The ability of the composites to
International Journal of Damage Mechanics, 2011
ABSTRACT: Charpy impact energy of functionally graded steels produced by elec-troslag remelting c... more ABSTRACT: Charpy impact energy of functionally graded steels produced by elec-troslag remelting composed of graded ferritic and austenitic layers together with bainite or martensite intermediate layer in crack divider configuration has been modeled. From loaddisplacement curves ...
Neural Network World, 2013
The final microstructure and resulting mechanical properties in the linepipe steels are predomina... more The final microstructure and resulting mechanical properties in the linepipe steels are predominantly determined by austenite decomposition during cooling after thermomechanical and welding processes. The paper presents some results of the research connected with the development of a new approach based on the artificial neural network to predicting the martensite fraction of the phase constituents occurring in five microalloyed steels after continuous cooling. The independent variables in the model are chemical compositions, niobium condition, austenitizing temperature, initial austenite grain size and cooling rate over the temperature range of the occurrence of phase transformations. For the purpose of constructing these models, 104 different experimental data were gathered from the literature. According to the input parameters in feedforward backpropagation algorithm, the constructed networks were trained, validated and tested. In this model, the training and testing results in the artificial neural network have shown a strong potential for prediction of effects of chemical compositions and heat treatments on phase transformation of microalloyed steels.
2009 IEEE International Symposium on Information Theory, 2009
The problem of bounding the reliability function of a multiple-access channel (MAC) is studied. A... more The problem of bounding the reliability function of a multiple-access channel (MAC) is studied. An upper bound on the minimum Bhattacharyya distance between codeword pairs is derived. For a certain large class of two-user discrete memoryless (DM) MAC, a lower bound on the maximal probability of decoding error is derived as a consequence of the upper bound on Bhattacharyya distance. Further, an upper bound on the average probability of decoding error is studied. It is shown that the corresponding upper and lower bounds have a similar structure. Using a conjecture about the structure of the multiuser code, a tighter lower bound for the maximal probability of decoding error is derived and is shown to be tight at zero rates.
Science China Technological Sciences, 2011
Abstract In the present paper, Charpy impact resistance of aluminum-epoxy laminated composites in... more Abstract In the present paper, Charpy impact resistance of aluminum-epoxy laminated composites in both crack divider and crack arrester configurations has been investigated. In both configurations, an analytical investigation has been carried out to evaluate the effects ...
Materials & Design, 2012
In the present study, Taguchi method was utilized to design compressive strength tests of geopoly... more In the present study, Taguchi method was utilized to design compressive strength tests of geopolymers produced by Portland cement as aluminosilicate source. Six main factors including NaOH concentration, water glass to NaOH weight ratio, alkali activator to cement ...
International Journal of Damage Mechanics, 2012
ABSTRACT
Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science, 2013
This article presents a novel 3-DOF parallel manipulator extracted from an origami fold in the co... more This article presents a novel 3-DOF parallel manipulator extracted from an origami fold in the context of mechanisms. The parallel manipulator consists of a base, a platform and four chain-legs that connect the platform to base through revolute joints. Each chain-leg contains a closed-loop sub-chain, which is spherical 6R linkage with symmetrical angle lengths. The geometry of the parallel manipulator is revealed according to the configuration design and specifics of the origami fold. This leads to unravelling of the symmetric plane which is determined by the common points of spherical 6R linkages in the four chain-legs. Based on geometric approach, the solutions for both inverse and forward kinematics are derived and the reachable workspace is then analyzed.
RSC Adv., 2015
Boroaluminosilicate geopolymers from a fly-ash source have a variety of microstructures. This may... more Boroaluminosilicate geopolymers from a fly-ash source have a variety of microstructures. This may be due to different mechanisms of geopolymerization.
SN Computer Science
Deep learning has recently gained remarkable results in action recognition. In this paper, an arc... more Deep learning has recently gained remarkable results in action recognition. In this paper, an architecture is proposed for action recognition, including ResNet feature extractor, Conv-Attention-LSTM, BiLSTM, and fully connected layers. Furthermore, a sparse layer after each LSTM layer is added to overcome overfitting. In addition to RGB images, optical flow is also used to incorporate motion information into our architecture. Due to similarities of consecutive frames, video sequences are divided into equal parts. Frames of successive parts are used as consecutive frames to obtain the flow. Furthermore, to find the significant regions, the convolutional attention network is applied. The proposed method is evaluated using two popular datasets, UCF-101, and HMDB-51 and its accuracy for these datasets is 95.24 and 71.62, respectively. Overfitting is reduced due to using a sparse layer instead of a dropout based on the results achieved. Moreover, a deep LSTM network leads to a higher recognition rate than one-layer LSTM.
Quarterly Journal of Economic Research and Policies
Materials
Currently, there are a very limited number of studies on the effect of admixtures on properties o... more Currently, there are a very limited number of studies on the effect of admixtures on properties of ‘one-part’ geopolymers. This paper reports the effects of different superplasticizers and retarders on fresh and hardened properties of one-part fly ash-slag blended geopolymers made by different solid activators. Two different grades of sodium silicate, namely anhydrous sodium metasilicate powder (nSiO2/nNa2O = 0.9) and GD Grade sodium silicate powder (nSiO2/nNa2O = 2.0) were used as the solid activators. Five different commercially available superplasticizers, including three modified polycarboxylate-based superplasticizers (denoted as PC1, PC2, and PC3) and two naphthalene-based superplasticizers (denoted as N1 and N2), as well as three different retarders, including sucrose, anhydrous borax and a commercially available retarder, were investigated. Workability, setting time and compressive strength of the mixtures without and with addition of each ‘individual’ admixture were measure...
International Journal of Damage Mechanics
ABSTRACT
International Journal of Damage Mechanics
ABSTRACT In the present work, compressive strength of ash-based geopolymers with different mixtur... more ABSTRACT In the present work, compressive strength of ash-based geopolymers with different mixtures of % rice husk ash, fly ash, nano alumina and nano silica has been predicted by fuzzy logic. The alkali activating was done by a mixture of sodium hydroxide and sodium silicate solution. It was found that oven curing temperature and sodium hydroxide concentration together with SiO2 nanoparticles has the main effects on compressive strength of the specimens. The fuzzy logic model was constructed by 12 input parameters including the water curing time, the rice husk ash content, the fly ash content, the water glass content, sodium hydroxide content, the water content, the aggregate content, SiO2 nanoparticles content, Al2O3 nanoparticles content, oven curing temperature, oven curing time and test trial number. The value for the output layer was the compressive strength. According to the input parameters in fuzzy model, the input data were trained, validated and tested. The results indicate that fuzzy model is a powerful tool for predicting the effect of nanoparticles on compressive strength of the geopolymers in the considered range.
International Journal of Damage Mechanics
Abstract Mechanical properties of concrete specimens containing CuO nanoparticles which were cure... more Abstract Mechanical properties of concrete specimens containing CuO nanoparticles which were cured in saturated limewater have been optimized. CuO nanoparticles were partially added to concrete as nano-fillers. The specimens were cured in water and saturated ...
Energy and Buildings, 2011
ABSTRACT
Corr, Oct 7, 2010
A new lower bound for the average probability or error for a two-user discrete memoryless (DM) mu... more A new lower bound for the average probability or error for a two-user discrete memoryless (DM) multiple-access channel (MAC) is derived. This bound has a structure very similar to the well-known sphere packing packing bound derived by Haroutunian. However, since explicitly imposes independence of the users' input distributions (conditioned on the time-sharing auxiliary variable) results in a tighter sphere-packing exponent in comparison to Haroutunian's. Also, the relationship between average and maximal error probabilities is studied. Finally, by using a known sphere packing bound on the maximal probability of error, a lower bound on the average error probability is derived.
ABSTRACT BACKGROUND AND OBJECTIVE: Pain is the most frequent symptom in different diseases. In mo... more ABSTRACT BACKGROUND AND OBJECTIVE: Pain is the most frequent symptom in different diseases. In modern medicine, there are two main categories of analgesics: opioids and non-steroidal anti-inflammatory drugs (NSAIDs). Given the importance of medicinal plants in the treatment of different diseases, this study aimed to compare the analgesic effects of the alcoholic extract of Teucrium with morphine and aspirin. METHODS: In this experimental study, 36 Wistar rats were randomly divided into six groups of 6. The negative control group received normal saline (5 ml/kg), two positive control groups received morphine 2.5 mg/kg and aspirin 300 mg/kg, and three treatment groups received hydro-alcoholic extract of Teucrium (100, 200 and 400 mg/kg) intraperitoneally in single doses. Half an hour after the intraperitoneal injection of the extract, 50 microlitres of 2.5% formalin was injected subcutaneously into the right paw of the rats, and the analgesic effects were compared using the formalin t...
Viral Nervous Necrosis (VNN) is a worldwide disease affecting several species of cultured marine ... more Viral Nervous Necrosis (VNN) is a worldwide disease affecting several species of cultured marine fish. For the past two decades, betanodavirus infections that cause Viral Nervous Necrosis (VNN) have emerged as major constraints on the culture and sea ranching of marine fish in almost all parts of the world. More than forty species mainly of marine origin have been so far affected and this number is likely to rise in future following the introduction of new species and the increase of aquaculture trade.
Journal of Materials in Civil Engineering, 2015
AbstractA hybrid adaptive neuro-fuzzy interfacial systems–imperialist competitive algorithm (ANFI... more AbstractA hybrid adaptive neuro-fuzzy interfacial systems–imperialist competitive algorithm (ANFIS-ICA) was presented to determine the effect of concentration of alkali solution, alkali binder to alkali solution weight ratio, alkali activator to ordinary portland cement (OPC) weight ratio, oven curing temperature, and age of curing on the compressive strength of OPC-based geopolymers. Optimization of the type and number of membership functions was carried out by ICA while the training, testin,g and validating of the collected data sets was conducted by ANFIS. The obtained results indicated that the proposed ANFIS-ICA model is capable to predict the compressive strength of geopolymeric specimens well and suitably determine the effect of each parameter on this property. A parametric study is presented to show the effect of each parameter predicted by the model on compressive strength of the specimens.
International Journal of Damage Mechanics, 2011
In this study, tensile strength of gypsum-based composite with aluminum fibers up to 15 vol.% was... more In this study, tensile strength of gypsum-based composite with aluminum fibers up to 15 vol.% was studied. To increase the interfacial bond strength between fibers and matrix, aluminum fibers were anodized under different conditions. Single fiber pull-out tests were carried out to investigate the bond strength. The interface was examined by scanning electron microscope. The ability of the composites to
International Journal of Damage Mechanics, 2011
ABSTRACT: Charpy impact energy of functionally graded steels produced by elec-troslag remelting c... more ABSTRACT: Charpy impact energy of functionally graded steels produced by elec-troslag remelting composed of graded ferritic and austenitic layers together with bainite or martensite intermediate layer in crack divider configuration has been modeled. From loaddisplacement curves ...
Neural Network World, 2013
The final microstructure and resulting mechanical properties in the linepipe steels are predomina... more The final microstructure and resulting mechanical properties in the linepipe steels are predominantly determined by austenite decomposition during cooling after thermomechanical and welding processes. The paper presents some results of the research connected with the development of a new approach based on the artificial neural network to predicting the martensite fraction of the phase constituents occurring in five microalloyed steels after continuous cooling. The independent variables in the model are chemical compositions, niobium condition, austenitizing temperature, initial austenite grain size and cooling rate over the temperature range of the occurrence of phase transformations. For the purpose of constructing these models, 104 different experimental data were gathered from the literature. According to the input parameters in feedforward backpropagation algorithm, the constructed networks were trained, validated and tested. In this model, the training and testing results in the artificial neural network have shown a strong potential for prediction of effects of chemical compositions and heat treatments on phase transformation of microalloyed steels.
2009 IEEE International Symposium on Information Theory, 2009
The problem of bounding the reliability function of a multiple-access channel (MAC) is studied. A... more The problem of bounding the reliability function of a multiple-access channel (MAC) is studied. An upper bound on the minimum Bhattacharyya distance between codeword pairs is derived. For a certain large class of two-user discrete memoryless (DM) MAC, a lower bound on the maximal probability of decoding error is derived as a consequence of the upper bound on Bhattacharyya distance. Further, an upper bound on the average probability of decoding error is studied. It is shown that the corresponding upper and lower bounds have a similar structure. Using a conjecture about the structure of the multiuser code, a tighter lower bound for the maximal probability of decoding error is derived and is shown to be tight at zero rates.
Science China Technological Sciences, 2011
Abstract In the present paper, Charpy impact resistance of aluminum-epoxy laminated composites in... more Abstract In the present paper, Charpy impact resistance of aluminum-epoxy laminated composites in both crack divider and crack arrester configurations has been investigated. In both configurations, an analytical investigation has been carried out to evaluate the effects ...
Materials & Design, 2012
In the present study, Taguchi method was utilized to design compressive strength tests of geopoly... more In the present study, Taguchi method was utilized to design compressive strength tests of geopolymers produced by Portland cement as aluminosilicate source. Six main factors including NaOH concentration, water glass to NaOH weight ratio, alkali activator to cement ...
International Journal of Damage Mechanics, 2012
ABSTRACT
Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science, 2013
This article presents a novel 3-DOF parallel manipulator extracted from an origami fold in the co... more This article presents a novel 3-DOF parallel manipulator extracted from an origami fold in the context of mechanisms. The parallel manipulator consists of a base, a platform and four chain-legs that connect the platform to base through revolute joints. Each chain-leg contains a closed-loop sub-chain, which is spherical 6R linkage with symmetrical angle lengths. The geometry of the parallel manipulator is revealed according to the configuration design and specifics of the origami fold. This leads to unravelling of the symmetric plane which is determined by the common points of spherical 6R linkages in the four chain-legs. Based on geometric approach, the solutions for both inverse and forward kinematics are derived and the reachable workspace is then analyzed.