Amirkabir University of Technology
AUT Journal of Modeling and Simulation
2588-2953
2588-2961
42
2
2010
03
01
Scheduling Single-Load and Multi-Load AGVs in Container Terminals
1
10
EN
Hassan
Rashidii
10.22060/miscj.2010.199
In this paper, three solutions for scheduling problem of the Single-Load and Multi-Load Automated Guided Vehicles (AGVs) in Container Terminals are proposed. The problem is formulated as Constraint Satisfaction and Optimization. When capacity of the vehicles is one container, the problem is a minimum cost flow model. This model is solved by the highest performance Algorithm, i.e. Network Simplex Algorithm (NSA). If the capacity of the AGVs increases, the problem is a NP-hard problem. This problem has a huge search space and is tackled by the Simulated Annealing Method (SAM). Three approaches for its initial solution and a neighborhood function to the search method are implemented. The third solution is a hybrid of SAM and NSA. This hybrid is applied to the Heterogeneous AGVs scheduling problem in container terminals. Several the same random problems are generated, solved by SAM with the proposed approaches and the simulation results are compared. The experimental results show that NSA provides a good initial solution for SAM when the capacity of AGVs is heterogeneous.
Simulated Annealing Method,Network Simplex Algorithm,Optimization methods,Container Terminals
http://miscj.aut.ac.ir/article_199.html
http://miscj.aut.ac.ir/article_199_76979b40c444c8e9e087cb07db5723b3.pdf
Amirkabir University of Technology
AUT Journal of Modeling and Simulation
2588-2953
2588-2961
42
2
2010
03
01
Small Scale Effect on the Buckling Analysis of a Double-Walled Carbon Nanotube under External Radial Pressure Using Energy Method
11
16
EN
Z. S.
Mousavi i
A.
Ghorbanpour Arani
M.
Mohammadimehr
10.22060/miscj.2010.201
In this paper, using energy method, small scale effects on the buckling analysis of a double-walled carbon nanotube (DWCNT) under external radial pressure is studied. The constitutive equations derived for a DWCNT using the nonlocal theory of elasticity which Eringen are presented for the first time. By minimizing the second variation of the total energy for a DWCNT, hence, the value of the nonlocal critical buckling load is obtained. It is seen from the results that the nonlocal critical buckling load increases with increasing the circumferential wave number. Moreover, it is seen that the nonlocal critical buckling load is lower than that of the local one. It is shown from the results that the ratio of the critical buckling load decreases with increasing the length of nanotubes while it increases with decreasing the radius of the outer tube.
Nonlocal shell model,Buckling,DWCNT,External radial pressure,Energy method
http://miscj.aut.ac.ir/article_201.html
http://miscj.aut.ac.ir/article_201_9efbf9cc4c099bdf34bbfd8c211be3b6.pdf
Amirkabir University of Technology
AUT Journal of Modeling and Simulation
2588-2953
2588-2961
42
2
2010
03
01
Buckling of Laminates with Multiple Through-the-Width Delaminations Using Spring Simulation Model
17
24
EN
M.
Kharazi
H. R
. Ovesyii
10.22060/miscj.2010.203
Delamination is one of the most common failure modes in composite structures. In particular, when the laminated composites are subjected to compressive loads, delamination becomes a constraint in the design process. In this study, the system is modeled as a plate supported by an elastic foundation. The elastic adhesive layer between the buckled sublaminates is represented by some parallel springs. The plate on a discontinuous foundation is treated as a continuous foundation but with added transverse forces at a number of discrete points in the delamination regions to make the net transverse force at each of these points to vanish. The delaminated plates which are analyzed in this study contain one or two through-the-width delaminations.Also, an extensive finite element analysis is performed by using ANSYS5.4 general purpose commercial software, and the results are compared with those obtained by the analytical model. The agreement between the results is very good.
delamination,Buckling,Composite laminates,Spring Simulation
http://miscj.aut.ac.ir/article_203.html
http://miscj.aut.ac.ir/article_203_bda04ca0268e0fffa2c5cf9c5bd80930.pdf
Amirkabir University of Technology
AUT Journal of Modeling and Simulation
2588-2953
2588-2961
42
2
2010
03
01
Study on Experimental and Modeling of Rotary Roll Dressing of Grinding Wheels
25
32
EN
A. H.
Azizii
S. M.
Rezaei
A.R.
Rahimi
H.
Baseri
10.22060/miscj.2010.204
Two of the important parameters in grinding operation are surface roughness of the workpiece and the amount of consumed energy. These parameters are strongly affected by the condition of grinding wheel surface which is dependent on the dressing parameters. Predicting the roughness of the grinding wheel surface after dressing with known dressing parameters can improve the grinding process. Researchers have presented several models of the grinding surface after dressing. In this article, these models are analyzed and an improved model along with computer simulation of grinding wheel surface is presented with regard to rotary dressing parameters. Finally, the model is verified with experimental results. The theoretical values reasonably compare with experimental results. On the basis of this model and experimental results the effect of different rotary roll dressing parameters on grinding wheel and workpiece surface roughness are discussed.
Rotary dressing,Dressing parameters,Roughness,Steady profile
http://miscj.aut.ac.ir/article_204.html
http://miscj.aut.ac.ir/article_204_dca7227bc368828f0a6bcb8aaa3e7f94.pdf
Amirkabir University of Technology
AUT Journal of Modeling and Simulation
2588-2953
2588-2961
42
2
2010
03
01
Molecular Dynamics Simulation of Al Energetic Nano Cluster Impact (ECI) onto the Surface
33
36
EN
K.
Mirabbaszadehi
P.
Nayebiii
S.
Saramad
E.
Zaminpayma
10.22060/miscj.2010.205
On the atomic scale, Molecular Dynamic (MD) Simulation of Nano Al cluster impact on Al (100) substrate surface has been carried out for energies of 1-20 eV/atom to understand quantitatively the interaction mechanisms between the cluster atoms and the substrate atoms. The many body Embedded Atom Method (EAM) was used in this simulation. We investigated the maximum substrate temperature Tmax and the time tmax within which this temperature is reached as a function of cluster sizes. The temperature Tmax is linearly proportional to both energy per atom and total cluster energy. For the constant energy per atom and the cluster size increase, the correlated collisions rapidly transferred energy to the substrate, and the time tmax approached a constant value. We investigated the temperature Tmax dependence on the total energy ET and the cluster size. We showed that the cluster implantation and sputtering atoms from the surface are affected by the cluster size and kinetic energy of the clusters. Finally, time dependence of the number Ndis of disordered atoms in the substrate was observed.
Molecular Dynamic Simulation,Embedded Atom Method potential,Nanocluster,Al,Thin Film,Disordered Atoms,Implantation Atoms,Sputtering Atoms
http://miscj.aut.ac.ir/article_205.html
http://miscj.aut.ac.ir/article_205_f54450eff4730a4d1be4181742086edb.pdf
Amirkabir University of Technology
AUT Journal of Modeling and Simulation
2588-2953
2588-2961
42
2
2010
03
01
Design and Construction of a New Capacitive Tactile Sensor for Measuring Normal Tactile Force
37
42
EN
S.
Mosafer Khoorjestani
S.
Najarianii
A
. Tavakoli Golpayganiiii
H.
Sherkativ
10.22060/miscj.2010.208
This paper presents the design, construction and testing of a new capacitive tactile sensor for measurement of normal tactile force. The operation of proposed sensor has been investigated in ASTABLE and MONOSTABLE circuits. According to the results of these circuits the deviation of ASTABLE circuit results is less than MONOSTABLE circuit results. In addition, the results obtained from ASTABLE circuit are less separable compared to those of MONOSTABLE circuit. Remarkable advantages of this circuit are its simplicity and low energy consumption aside from its ability to be miniaturized which makes it a good substitute for the sensor in robotics and medical sciences such as minimally invasive surgery (MIS).
Tactile Sensor,Capacitive Sensor,Tactile Force
http://miscj.aut.ac.ir/article_208.html
http://miscj.aut.ac.ir/article_208_f96b01c30acfe603f5bae25810cc8011.pdf
Amirkabir University of Technology
AUT Journal of Modeling and Simulation
2588-2953
2588-2961
42
2
2010
03
01
A New High-order Takagi-Sugeno Fuzzy Model Based on Deformed Linear Models
43
54
EN
Ahmad
Kalhor
akalhor@ut.ac.ir
Babak N.
Araabi
Caro
Lucasi
10.22060/miscj.2010.210
Amongst possible choices for identifying complicated processes for prediction, simulation, and approximation applications, high-order Takagi-Sugeno (TS) fuzzy models are fitting tools. Although they can construct models with rather high complexity, they are not as interpretable as first-order TS fuzzy models. In this paper, we first propose to use Deformed Linear Models (DLMs) in consequence parts of a TS fuzzy model, which provides both complexity and interpretability. We then prove that in order to minimize considered error indices, linear and nonlinear parts of DLMs can be optimized independently. A localization of DLMs in input-space of the TS fuzzy model is done using an appropriate sigmoid-based membership function, which can represent a fuzzy subspace with enough smoothness and flat top. An incremental algorithm is also proposed to identify the suggested fuzzy model. Then, through an illustrative example, the formation of DLMs to approximate a nonlinear function is demonstrated. The applicability and effectiveness of the introduced fuzzy modeling approach is examined in three case studies: prediction of a chaotic time series, identification of a steam generator model, and approximation of a nonlinear function for a sun sensor. The obtained results demonstrate the higher accuracy and better generalization of our modeling approach as compared with those of some other well-known state-of-the-art approaches.
Takagi Sugeno fuzzy model,Identification,deformed linear models,sigmoid-based membership function,prediction and approximation
http://miscj.aut.ac.ir/article_210.html
http://miscj.aut.ac.ir/article_210_c89e836af7cf361d06af4ec8c003d482.pdf
Amirkabir University of Technology
AUT Journal of Modeling and Simulation
2588-2953
2588-2961
42
2
2010
03
01
An ANOVA Based Analytical Dynamic Matrix Controller Tuning Procedure for FOPDT Models
55
64
EN
Peyman
Bagheri
Ali
Khaki-Sedigh
10.22060/miscj.2010.212
Dynamic Matrix Control (DMC) is a widely used model predictive controller (MPC) in industrial plants. The successful implementation of DMC in practical applications requires a proper tuning of the controller. The available tuning procedures are mainly based on experience and empirical results. This paper develops an analytical tool for DMC tuning. It is based on the application of Analysis of Variance (ANOVA) and nonlinear regression analysis for First Order plus Dead Time (FOPDT) process models. It leads to a simple formula which involves the model parameters. The proposed method is validated via simulations as well as experimental results. A nonlinear pH neutralization model is used for the simulation studied. It is further implemented on a laboratory scale control level plant. A robustness analysis is performed based on the simulation results. Finally, comparison results are provided to show the effectiveness of the proposed methodology.
Dynamic Matrix Control,Tuning,Analysis of Variance (ANOVA),Nonlinear Regression,FOPDT,industrial processes,pH process,Level process
http://miscj.aut.ac.ir/article_212.html
http://miscj.aut.ac.ir/article_212_11c032705367d8997ecd35514b0bb367.pdf