2018-07-20T08:16:50Z
http://miscj.aut.ac.ir/?_action=export&rf=summon&issue=245
AUT Journal of Modeling and Simulation
2588-2953
2588-2953
2017
49
2
NGTSOM: A Novel Data Clustering Algorithm Based on Game Theoretic and Self- Organizing Map
M.
Ghayekhloo
M. B.
Menhaj
R.
Azimi
E.
Shekari
Identifying clusters is an important aspect of data analysis. This paper proposes a noveldata clustering algorithm to increase the clustering accuracy. A novel game theoretic self-organizingmap (NGTSOM ) and neural gas (NG) are used in combination with Competitive Hebbian Learning(CHL) to improve the quality of the map and provide a better vector quantization (VQ) for clusteringdata. Different strategies of Game Theory are proposed to provide a competitive game for nonwinningneurons to participate in the learning phase and obtain more input patterns. The performanceof the proposed clustering analysis is evaluated and compared with that of the K-means, SOM andNG methods using different types of data. The clustering results of the proposed method and existingstate-of-the-art clustering methods are also compared which demonstrates a better accuracy of theproposed clustering method.
clustering
game theory
self-organizing map
vector quantization
2017
12
01
133
142
http://miscj.aut.ac.ir/article_850_f0ab9b6e8ac07d0e8ea61b493ea2e467.pdf
AUT Journal of Modeling and Simulation
2588-2953
2588-2953
2017
49
2
Thermo-Electro Mechanical Impedance based Structural Health Monitoring: Euler- Bernoulli Beam Modeling
N.
Sepehry
F.
Bakhtiari-Nejad
M.
Shamshirsaz
In recent years, impedance measurement method by piezoelectric (PZT) wafer activesensor (PWAS) has been widely adopted for non-destructive evaluation (NDE). In this method, theelectrical impedance of a bonded PWAS is used to detect a structural defect. The electro-mechanicalcoupling of PZT materials constructs the original principle of this method. Accordingly, the electricalimpedance of PWAS can sense any change in the mechanical impedance of the structure. A thermalstress on a structure, which was generated by environmental temperature, could change the electricalimpedance of PWAS. The thermal stress which affects the output impedance of PWAS is alsodeveloped. A temperature-dependent model, the temperature dependency of PWAS, and structurematerial properties are investigated for a PWAS bonded to an Euler Bernoulli clamped-clamped beam.The Rayleigh-Ritz and spectral element methods are studied and, then, verified by 3D finite elementmethod (FEM).
Thermal Stress
Euler Bernoulli Beam
Spectral Element Method
Impedance-based Structural Health
Monitoring
3D FEM
2017
12
01
143
152
http://miscj.aut.ac.ir/article_841_2effa710256b56de16a48c760007bd92.pdf
AUT Journal of Modeling and Simulation
2588-2953
2588-2953
2017
49
2
Generalized Aggregate Uncertainty Measure 2 for Uncertainty Evaluation of a Dezert-Smarandache Theory based Localization Problem
A.
Mohammad-Shahri
M.
Khodabandeh
In this paper, Generalized Aggregated Uncertainty measure 2 (GAU2), as a newuncertainty measure, is considered to evaluate uncertainty in a localization problem in which cameras’images are used. The theory that is applied to a hierarchical structure for a decision making to combinecameras’ images is Dezert-Smarandache theory. To evaluate decisions, an analysis of uncertainty isexecuted at every level of the decision-making system. The second generalization of AggregatedUncertainty measure (GAU2) which is applicable for DSmT results is used as a supervisor. TheGAU2 measure in spite of the GAU1 measure can be applied to the problems with vague borders orcontinuous events. This measure may help to make decisions based on better preference combinationsof sensors or methods of fusion. GAU2 is used to evaluate uncertainty after applying classic DSmTand hybrid DSmT with extra knowledge. Therefore by using the decision making system, results withless uncertainty are generated in spite of high conflict sensory data.
Data Fusion
Camera Image
Uncertainty Measurement
Dezert-Smarandache Theory
2017
12
01
153
162
http://miscj.aut.ac.ir/article_826_62c1ad4ffed85ea7ed0c44a461c36d2a.pdf
AUT Journal of Modeling and Simulation
2588-2953
2588-2953
2017
49
2
Near-Optimal Controls of a Fuel Cell Coupled with Reformer using Singular Perturbation methods
S.
Nazem-Zadeh
M.T.
Hamidi-Beheshti
A singularly perturbed model is proposed for a system comprised of a PEM Fuel Cell(PEM-FC) with Natural Gas Hydrogen Reformer (NG-HR). This eighteenth order system is decomposedinto slow and fast lower order subsystems using singular perturbation techniques that provides tools forseparation and order reduction. Then, three different types of controllers, namely an optimal full-order,a near-optimal composite controller based on the slow and the fast subsystems, and a near-optimalreduced-order controller based on the reduced-order model, are designed. The comparison of closedloopresponses of these three controllers shows that there are minimal degradations in the performanceof the composite and the reduced order controllers.
singular perturbation technique
two-time scale systems
Schur decomposition method
near-optimal controller
slow/fast subsystems
2017
12
01
163
172
http://miscj.aut.ac.ir/article_872_be5eb01dfaf7d24ab72538250530a60b.pdf
AUT Journal of Modeling and Simulation
2588-2953
2588-2953
2017
49
2
A Hybrid Modeling for Continuous Casting Scheduling Problem
M. H.
Fazel Zarandi
F.
Kashani Azad
A. H.
Karimi Kashani
This paper deals with a multi-agent-based interval type-2 fuzzy (IT2F) expert systemfor scheduling steel continuous casting. Continuous caster scheduling is a complex and extensiveprocess that needs expert staff. In this study, a distributed multi-agent-based structure is proposed as asolution. The agents used herein can cooperate with each other via various communication protocols.To facilitate such communication, an appropriate negotiation protocol (i.e., contract net protocol)is proposed. The due dates specified by expert staff are represented by IT2F membership functions(MFs). As a part of the objective functions, a simple procedure is proposed to calculate the totalearliness and tardiness penalty when the due date’s MFs are IT2F. The proposed hybrid multi-agentbasedsystem combines the multi-agent systems with type-2 fuzzy concepts which conforms to thereal-world continuous casting problem.
Steel production
Continuous caster scheduling
Agent-based system
Negotiation
Fuzzy system
2017
12
01
173
180
http://miscj.aut.ac.ir/article_891_7933ef1a4ae92bc899f1c0c44ef86358.pdf
AUT Journal of Modeling and Simulation
2588-2953
2588-2953
2017
49
2
Developing a Model for Measuring Severity of Effects Caused by Interconnected Units in Electronic Supply Chains
A.
Kazemi
L.
Ahmadpour
For many electronic supply chain networks in the world that can comprise hundreds ofcompanies with several tiers of suppliers and intermediate customers, there are numerous presentingrisks to consider. In the electronic supply chain, the situation are even worse, for the characteristics ofthis supply chain: excessive lean management, global sourcing and the rather more uncertain marketdemand. Electronic companies are forced to manage their supply chains effectively to increase efficiencyand reactivity. This paper proposes a mathematical model for estimating the severity of interactionsbetween supply chain’s units and how their affect on the entire supply chain. Based on the model,scholars can model supply chains easily with considering interconnected units. Basic characteristics ofsupply chains are considered in the model. The units, which are used to simulate the members of supplychains, produce appropriate products by intelligent choices. The relationships on units are connected bytheir activities ; then, the proposed model is applied to an experimental example. The model yields itsnumerical parameters and responses by means of Lingo software.
Supply chain
Interconnected units
Propagated effect
2017
12
01
181
186
http://miscj.aut.ac.ir/article_928_1afc3206ba6ce995a47c88b84e962235.pdf
AUT Journal of Modeling and Simulation
2588-2953
2588-2953
2017
49
2
Partial Observation in Distributed Supervisory Control of Discrete-Event Systems
V.
Saeidi
A.
Afzalian
D.
Gharavian
Distributed supervisory control is a method to synthesize local controllers in discrete-eventsystems with a systematic observation of the plant. Some works were reported on extending this methodby which local controllers are constructed so that observation properties are preserved from monolithic todistributed supervisory control, in an up-down approach. In this paper, we find circumstances in whichobservation properties are preserved from monolithic to distributed supervisory control. Local observationproperties, i.e. local normality and local relative observability are employed for investigating observationproperties of each local controller, which are constructed by any localization algorithm that preserves controlequivalency to the monolithic supervisor with respect to the plant. These properties enable us to investigatethe observation properties from monolithic to distributed supervisory control. Moreover, observationequivalence property is defined according to the control equivalence in a distributed supervisory controlwith partial observation. It is proved that with preserving observation equivalence of the local controllers tothe monolithic supervisor, the control equivalence is satisfied, if and only if the intersection of local eventsets is a subset of or equal to the global observable event set.
Distributed Supervisory Control
Local Normality
Local Relative Observability
Observation Equivalent
2017
12
01
187
198
http://miscj.aut.ac.ir/article_929_16b8a43c2081f9e64e34c7aedf3b6d5e.pdf
AUT Journal of Modeling and Simulation
2588-2953
2588-2953
2017
49
2
Saturated Neural Adaptive Robust Output Feedback Control of Robot Manipulators:An Experimental Comparative Study
M.
Pourrahim
K.
Shojaei
A.
Chatraei
O.
Shahnazari
In this study, an observer-based tracking controller is proposed and evaluatedexperimentally to solve the trajectory tracking problem of robotic manipulators with the torque saturationin the presence of model uncertainties and external disturbances. In comparison with the state-of-the-artobserver-based controllers in the literature, this paper introduces a saturated observer-based controllerbased on a radial basis function neural network. This technique helps the controller produce feasiblecontrol signals for the robot actuators. As a result, it efficiently diminishes the actuators saturation riskand consequently, a better transient performance is obtained. The stability analyses of the dynamicsof the tracking errors and state estimation errors are given with the help of a Lyapunov-based stabilityanalysis method. The theoretical analyses will systematically prove that the errors are semi-globallyuniformly ultimately bounded and they converge to a small set around the origin whose size is adjustableby a suitable tuning of parameters. At last, some real experiments are performed on a laboratory roboticarm to illustrate the efficiency of the proposed control system for real industrial applications.
Actuator saturation
Adaptive robust control
Observer-based control
RBF neural networks
Robot manipulators
2017
12
01
199
208
http://miscj.aut.ac.ir/article_927_8fb0769fff0992f1289a320fb75d553d.pdf
AUT Journal of Modeling and Simulation
2588-2953
2588-2953
2017
49
2
Adaptive Control Strategy for a Bilateral Tele- Surgery System Interacting with Active Soft Tissues
M.
Sharifi
H. A.
Talebi
In this paper, the problem of control and stabilization of a bilateral tele-surgery roboticsystem in interaction with an active soft tissue is considered. To the best of the authors’ knowledge, theprevious works did not consider a realistic model for a moving soft tissue like heart tissue in beating heartsurgery. Here, a new model is proposed to indicate significant characteristics of a moving soft tissue,rolling as the teleoperation system environment. The model is formed by a parallel combination of aviscoelastic passive part and an active part. Furthermore, the delays in communication and parameteruncertainties of the master and slave robot dynamics are considered. Using an adaptive control strategy,the ultimate boundedness of the system trajectories while interacting with the active environment iscertified, and this ultimate bound is calculated. Moreover, to evaluate the theoretical results, simulationresults are presented.
active soft tissue
viscoelastic model
bilateral tele robotic surgery
communication time delay
Adaptive control
2017
12
01
209
216
http://miscj.aut.ac.ir/article_931_282271bd5de6a49ee9ee04e5d61d6a2b.pdf
AUT Journal of Modeling and Simulation
2588-2953
2588-2953
2017
49
2
3-RPS Parallel Manipulator Dynamical Modelling and Control Based on SMC and FL Methods
M.
Shahidi
J.
Keighobadi
A. R.
Khoogar
In this paper, a dynamical model-based SMC (Sliding Mode Control) is proposed fortrajectory tracking of a 3-RPS (Revolute, Prismatic, Spherical) parallel manipulator. With ignoring smallinertial effects of all legs and joints compared with those of the end-effector of 3-RPS, the dynamical model ofthe manipulator is developed based on Lagrange method. By removing the unknown Lagrange multipliers, thedistribution matrix of control input vector disappears from the dynamical equations. Therefore, the calculationof the aforementioned matrix is not required for modeling the manipulator. It in trun results in decreasedmathematical manipulation and low computational burden. As a robust nonlinear control technique, a SMCsystem is designed for the tracking of the 3-RPS manipulator. According to Lyapunov’s direct method, theasymptotic stability and the convergence of 3-RPS manipulator to the desired reference trajectories areproved. Based on computer simulations, the robust performance of the proposed SMC system is evaluatedwith respect to FL (feedback linearization) method. The proposed model and control algorithms can beextended to different kinds of holonomic and non-holonomic constrained parallel manipulators.
Parallel manipulator
Dynamic modeling
Trajectory tracking
Feedback linearization
sliding mode control
2017
12
01
217
226
http://miscj.aut.ac.ir/article_992_2482dcbd28346f86423d607657ec9d64.pdf
AUT Journal of Modeling and Simulation
2588-2953
2588-2953
2017
49
2
A Comparison Between Fourier Transform Adomian Decomposition Method and Homotopy Perturbation ethod for Linear and Non-Linear Newell-Whitehead-Segel Equations
S. S.
Nourazar
H.
Parsa
A.
Sanjari
In this paper, a comparison among the hybrid of Fourier Transform and AdomianDecomposition Method (FTADM) and Homotopy Perturbation Method (HPM) is investigated.The linear and non-linear Newell-Whitehead-Segel (NWS) equations are solved and the results arecompared with the exact solution. The comparison reveals that for the same number of componentsof recursive sequences, the error of FTADM is much smaller than that of HPM. For the non-linearNWS equation, the accuracy of FTADM is more pronounced than HPM. Moreover, it is shown thatas time increases, the results of FTADM, for the linear NWS equation, converges to zero. And for thenon-linear NWS equation, the results of FTADM converges to 1 with only six recursive components.This is in agreement with the basic physical concept of NWS diffusion equation which is in turn inagreement with the exact solution.
Fourier Transform and Adomian
Decomposition Method
Homotopy Perturbation Method
Newell–Whitehead-Segel Equation
Nonlinear Partial Differential
Equation
2017
12
01
227
238
http://miscj.aut.ac.ir/article_990_904b8331d108cdb9ea1cc3cdaaec53af.pdf
AUT Journal of Modeling and Simulation
2588-2953
2588-2953
2017
49
2
A Survey of Dynamic Replication Strategies for Improving Response Time in Data Grid Environment
N.
Mansouri
M. M.
Javidi
Large-scale data management is a critical problem in a distributed system such as cloud,P2P system, World Wide Web (WWW), and Data Grid. One of the effective solutions is data replicationtechnique, which efficiently reduces the cost of communication and improves the data reliability andresponse time. Various replication methods can be proposed depending on when, where, and howreplicas are generated and removed. In this paper, different replication algorithms are investigated todetermine which attributes are assumed in a given algorithm and which are declined. We provide a tabularrepresentation of important factors to facilitate the future comparison of data replication algorithms. Thispaper also presents some interesting discussions about future works in data replication by proposingsome open research challenges.
Data Grid
Dynamic Replication
Data Availability
Simulation
2017
12
01
239
264
http://miscj.aut.ac.ir/article_874_28197c0a307fd6468830364b3b3d1ed2.pdf