D. Jelodar; D. Moazzami; P. Nasehpour
Abstract
A special class of cubic graphs are the cycle permutation graphs. A cycle permutation graph Pn( α) is defined by taking two vertex-disjoint cycles on n vertices and adding a matching between the vertices of the two cycles.In this paper we determine a good upper bound for tenacity of cycle permutation ...
Read More
A special class of cubic graphs are the cycle permutation graphs. A cycle permutation graph Pn( α) is defined by taking two vertex-disjoint cycles on n vertices and adding a matching between the vertices of the two cycles.In this paper we determine a good upper bound for tenacity of cycle permutation graphs.
Arif Mehmood; Fawad Nadeem; Choonkil Park; Giorgio Nordo; Humaira Kalsoom; Muhammad Rahim Khan; Naeem Abbas
Abstract
In this paper, the notion of generalized neutrosophic soft open set (GNSOS) in neutrosophic soft open set (GNSOS) in neutrosophic soft topological structures relative to neutrosophic soft points is introduced.The concept of generalized neutrosophic soft separation axioms in neutrosophic soft topological ...
Read More
In this paper, the notion of generalized neutrosophic soft open set (GNSOS) in neutrosophic soft open set (GNSOS) in neutrosophic soft topological structures relative to neutrosophic soft points is introduced.The concept of generalized neutrosophic soft separation axioms in neutrosophic soft topological spaces with respect to soft points. Several related properties, structural characteristics have been investigated. Then the convergence of sequence in neutrosophic soft topological space is defined and its uniqueness in generalized neutrosophic soft Hausdorff space (GNSHS) relative to soft points is examined. Neutrosophic monotonous soft function and its characteristics are switched over to different results. Lastly, generalized neutrosophic soft product spaces with respect to crisp points have been addressed.
Seyyed Ali Alavi Nasab; Hamid Moharrami; Vahid Johari Majd; Mansour Zia'ee Fard; Amir Khajeh Pour
Abstract
In this paper a new approach to formulation of active control of structures based on energy concepts and use of Linear Quadratic Regulator (LQR) has been proposed. The suggested method eliminates the trial and error procedure in finding appropriate gain matrices in active control of structures. In this ...
Read More
In this paper a new approach to formulation of active control of structures based on energy concepts and use of Linear Quadratic Regulator (LQR) has been proposed. The suggested method eliminates the trial and error procedure in finding appropriate gain matrices in active control of structures. In this method the gain matrix is obtained by considering the energy of the structure and it remains constant for all types of earthquake input.
To show the efficiency of the proposed method, a three-story building with two active tendons in the first and third floors is considered. The proposed gain selection and other techniques reported in the literature for LQR controllers have been used to compare the response of the structure for three accelerograms. A comparison of the displacements and control forces shows that although the maximum displacement in the proposed method is negligibly more than classical LQR methods, but the control forces are considerably less than the classical methods. Comparison of the results for an earthquake with various levels of scaling also shows that the proposed method is not sensitive to the intensity of input earthquake.
Farzad Ebrahimi; Mohammad Hassan Naei
Abstract
Stress-intensity factors (SIFs) are the most important parameters in fracture mechanics analysis of structures. These parameters are evaluated for a stationary crack in functionally graded plates of arbitrary geometry using a novel Galerkin based mesh-free method. The method involves an element-free ...
Read More
Stress-intensity factors (SIFs) are the most important parameters in fracture mechanics analysis of structures. These parameters are evaluated for a stationary crack in functionally graded plates of arbitrary geometry using a novel Galerkin based mesh-free method. The method involves an element-free Galerkin method (EFGM), where the material properties are smooth functions of spatial coordinates and two newly developed interaction integrals for mixed-mode fracture analysis. Numerical examples for mode-I fracture problems are presented to evaluate the accuracy of SIFs calculated by the proposed EFGM. Comparisons have been made between the SIFs predicted by EFGM and available reference solutions in the literature, generated either analytically or by FEM using various other fracture integrals or analyses. A good agreement is obtained between the results of the proposed meshless method and the reference solutions.
Amir Hossein Alizadeh; Ali Reza Keshavarz; Manouchehr Haghighi; Ali Reza Salehpour
Abstract
In this paper, the effect of flow rate on relative permeability curves was investigated in Iranian carbonate rocks. Core samples were prepared from outcrop of Asmari formation. The dynamic displacement experiments were performed at 2.55, 3.55, 4.55 and 5.55 cc/hr during waterflooding and oilflooding. ...
Read More
In this paper, the effect of flow rate on relative permeability curves was investigated in Iranian carbonate rocks. Core samples were prepared from outcrop of Asmari formation. The dynamic displacement experiments were performed at 2.55, 3.55, 4.55 and 5.55 cc/hr during waterflooding and oilflooding. Relative permeabilities have been calculated with the Jones and Roszelle method and then the flow rate effect was investigated. The end-points and crossover saturations in the relative permeability curves indicate water wetness. In the waterflooding process, water relative permeability curves and end-point were not affected by the flow rate. It was observed that the oil curves vary with the flow rate, decreasing with its decrease. This variation vanishes at the middle saturations. Also, in the oilflooding, water relative permeabilities behave the same as it observed in waterflooding. It was not possible to find any trend in kro and end-point saturation with the flow rate. In contrast to sandstone, hysteresis was observed in both krw and kro curves. With increasing the flow rate, this phenomenon increases in water curves and decreases in oil curves.
Nazli Shahidi; Mahmoud Nili Ahmadabadi; Yosra Pouyeshman
Abstract
This study mainly concentrates on metallurgical structure of the ferrous ancient crafts, specially the discovered ferrous man-made pieces in Ilam which are aged more than 3000 years. The pieces were discovered in Ize a town located in the south east of Ahvaz , in the southern of Iran. The crafts include ...
Read More
This study mainly concentrates on metallurgical structure of the ferrous ancient crafts, specially the discovered ferrous man-made pieces in Ilam which are aged more than 3000 years. The pieces were discovered in Ize a town located in the south east of Ahvaz , in the southern of Iran. The crafts include an ferrous bar, a 3-side and a 4 side bayonets which were microscopically studied by Electron and Optical Microscopes. The Microscopic result shows that the main microstructure of the ironic crafts are ferritic with a minor pearlite which means the main composition of the crafts is low carbon iron. This finding was also confirmed by chemical analysis of the craft. In addition, a few micro-impurities were detected in the microstructures which were characterized as Slags. The slags were supposedly constrained in the crafts during hot forging process. Although the slags had different morphologies their compositions were iron oxides.
Ziaeddin Pourkarimi; Ali Dehghani Ahmadabadi; Mohammad Noparast; Seyyed Ziaeddin Shafaei; Mohammad Reza Soltani
Abstract
Simulation of grinding circuits has being performed from 30 years ago and is also to be more complete and powerful approach with improvement of mathematical models which simulate various processing units/machines. The modeling and simulation of various mineral processing circuits are presently performed. ...
Read More
Simulation of grinding circuits has being performed from 30 years ago and is also to be more complete and powerful approach with improvement of mathematical models which simulate various processing units/machines. The modeling and simulation of various mineral processing circuits are presently performed. In order to simulate the present grinding circuits of Esfordi Phosphate processing plant, at first the breakage and selection functions of its ball mill’s feed sample were determined. According to obtained results, maximum value of selection function (selectivity of particles to be broken), was measured which was equal to 0.011886 min.-1 for 600 microns size fraction (d80 of ball mill feed at primary design). Then by using NGOTC software and measured residency times of particles in ball mill (average residency time in ball mill) which was 2.07 minutes (maximum time was 20 minutes), the selection function of ore was calculated in industrial scale, and accordingly the effect of using balls with various diameters were estimated. The results of selection function indicated that its maximum value reaches to 2.5238 min.-1, when balls with 25mm diameters to be used in ball mill. Finally by using BMCS software (ball mill circuit simulator), primary design data, and results obtained from various experiments, the circuit simulation was carried out. This procedure yielded optimized values of some required parameters such as size distribution and solid percent of ball mill product, and then the results were compared with current circuit values. However the estimated results and their vicinity to current ones proved the fact of estimation accuracy.
Mohammad Mehdi Montazer Rahmati; Seyyed Hossein Ghafeleh Bashi
Abstract
Process control of a spray dryer that is usually used as the last step of production is very crucial in obtaining a quality standard product. To this end, predicting the effect of various operating and environmental parameters on product properties is essential. Modeling was done in microscopic and macroscopic ...
Read More
Process control of a spray dryer that is usually used as the last step of production is very crucial in obtaining a quality standard product. To this end, predicting the effect of various operating and environmental parameters on product properties is essential. Modeling was done in microscopic and macroscopic scales by modifying the mass and heat transfer equations used in investigating the drying mechanism. However, as far as momentum transfer is concerned, the equations are the same as the ones used in the available literature models. Unlike conventional models that take only the two streams of hot air and sprayed droplets into account, a third stream is considered in our proposed model and this modification improved the results significantly. The model equations were solved numerically and a new simulation software was developed using Visual C++ 6.0. The model results are in good agreement with the industrial data obtained from a detergent producing plant.
Reza Khalou Kaka'i
Abstract
With the advent and wide spread use of computers a number of algorithms have been developed to determine the optimum ultimate pit limits in open pit mining. The main objective of these algorithms is to find groups of blocks that should be removed to yield the maximum overall mining profit under specified ...
Read More
With the advent and wide spread use of computers a number of algorithms have been developed to determine the optimum ultimate pit limits in open pit mining. The main objective of these algorithms is to find groups of blocks that should be removed to yield the maximum overall mining profit under specified economic conditions and technological constraints. The most common methods are: Lerchs and Grossmann algorithm based on graph theory, the Korobov algorithm, floating or moving cone method, moving cone II and dynamic programming. Among these, the Lerchs-Grossmann algorithm is the only method that always yields the true optimum pit. The disadvantages of the algorithm are complexity of the method and require more computing time than other methods to find out optimum pit outline. The floating cone approach which does not yield a true optimum pit in some cases is the most popular and simplest method and requires significantly less computing time than any other method to reach a solution. The moving cone II has been developed by Wright to overcome the shortfalls of the floating cone method. In this paper the moving cone II has been evaluated for being as a true optimum open pit design method and also two algorithms has been proposed for modification of this method. For this purpose C++ computer programs have been developed under Windows operating system for these algorithms and their results are compared with the Lerchs and Grossmann method, which is the true optimum open pit design algorithm. The outcomes show that these algorithms are able to produce good results.
Mohammad Sa'adat Seresht; Farhad Samadzadegan
Abstract
Nowadays, the subject of vision metrology network design is local enhancement of the existing network. In the other words, it has changed from first to third order design concept. To improve the network, locally, some new camera stations should be added to the network in drawback areas. The accuracy ...
Read More
Nowadays, the subject of vision metrology network design is local enhancement of the existing network. In the other words, it has changed from first to third order design concept. To improve the network, locally, some new camera stations should be added to the network in drawback areas. The accuracy of weak points is enhanced by the new images, if the related vision constraints are satisfied simultaneously. Therefore, the camera placement is an optimization problem that here is solved by using NSGA-II, a multi-objective evolutionary algorithm (MOEA) based on Pareto front concept. Although we have proposed two deterministic ITO and OTI methods and a non-deterministic fuzzy camera placement method in our previous research, here we solved the problem by an MOEA method. The NSGA-II network design method is able to solve the problem in complex cases in which other aforementioned methods are failed or cannot converge to global optimum. In addition, it is a good means to analysis the capabilities of other methods especially in complex network cases. It also gives us several optimal solutions for camera placement, so that designer can select one of them based on his/her experience and environmental restrictions. In this research, we did various tests on a complex example of camera placement by using NSGA-II algorithm. The result demonstrates the high capabilities of the method in solving and analyzing the camera placement in complex close-range photogrammetric networks.
Ghoamreza Shahriar Heshmati; Bahman Mehri
Abstract
In this paper a method is presented in details to solve a nonlinear partial differential equation which has many applications in engineering fields. The boundary condition is mixed to be able to define the value of function on its variation on the boundary. Examples are given to demonstrate the accuracy ...
Read More
In this paper a method is presented in details to solve a nonlinear partial differential equation which has many applications in engineering fields. The boundary condition is mixed to be able to define the value of function on its variation on the boundary. Examples are given to demonstrate the accuracy and efficiency of the method.
Roozbeh Shad; Hamid Ebadi; Mohammad Sa'di Mesgari; Ali Vafaee Nejad
Abstract
Different industrial decision makers and managers in our country, try to select and organize locations for aggregating industrial units, estates and areas with respect to land use planning visions and industrial development strategies. In this regard, considering large quantity of the input data and ...
Read More
Different industrial decision makers and managers in our country, try to select and organize locations for aggregating industrial units, estates and areas with respect to land use planning visions and industrial development strategies. In this regard, considering large quantity of the input data and diverse criteria affecting this application, it is complicated and difficult to optimally make decision. Geographical Information System (GIS) is able to provide the decision-makers with appropriate tools for removing the difficulties and complexities of site selection process. For this purpose, spatial functions allow selecting an optimum site by using input maps through aggregated operators. These functions are categorized into various groups such as Boolean, Index overlay, Fuzzy logic, Genetic and Weighted evidence, with respect to their activities. So, it is essential to determine appropriate aggregated functions for designing and implementing an applied GIS for selecting optimum industrial estate. In this paper, first, conditions and factors influencing industrial estates site selection are determined and made ready for being entered into aggregated functions. Then, different properties of Index overlay, Fuzzy, Genetic and Weighted evidence models are evaluated for functional efficiency and output accuracy results. Finally, considering the results obtained from different stages, the appropriate model is determined and desirable user interface is developed. As a result of implementing, it was found that Index overlay model with 2.2 seconds time ratio and 5 positive efficiency is the best model for aggregating industrial estate site selection parameters as compared to Fuzzy, Genetic and Weighted evidence models.
Ahmad Assempour; Sa'eed As'adi
Abstract
In this paper, a mathematical model for symmetrical multi-layer sheet rolling, in which the layers are unbounded before rolling, by using the upper bound method and stream function theorem is proposed. Using this model, we can investigate the plastic deformation behavior of sheets at the roll gap during ...
Read More
In this paper, a mathematical model for symmetrical multi-layer sheet rolling, in which the layers are unbounded before rolling, by using the upper bound method and stream function theorem is proposed. Using this model, we can investigate the plastic deformation behavior of sheets at the roll gap during rolling. Effect of various rolling conditions such as initial and final thickness and flow stress of sheets, friction factors, rolling velocity and etc. on the rolling power and force, the thickness reduction of each layer, the relative length of plastic region in each layer and etc. are discussed. The velocity field derived from the newly proposed stream function can automatically satisfy the volume constancy and velocity boundary conditions within the roll gap. The optimized velocity fields are obtained through the minimization of total power, which is expressed by the function of five pseudo-independent parameters, during the plastic deformation. The analytical predictions from the proposed model were compared with the analytical and experimental results of other investigators and a good agreement is shown. Present model is applicable for simulating and online control applications of the rolling process of multilayer sheets.
Ahmad Jafari; Mohammad Farough Hosseini; Aref Alipour
Mohammad Torkamandi; Mohammad Taghi Hamidi Beheshti
Arash Tavighi; Saeed Afsharnia; Hassan Monsef
Abstract
Today, with attention to increase in sensitive electrical equipments application in distribution networks and their susceptibility to the power quality deficiencies, the protection necessity of sensitive loads against undesirable effects of these disturbances are in focus. So, in this paper voltage sag ...
Read More
Today, with attention to increase in sensitive electrical equipments application in distribution networks and their susceptibility to the power quality deficiencies, the protection necessity of sensitive loads against undesirable effects of these disturbances are in focus. So, in this paper voltage sag deficiency and Dynamic Voltage Restorer (DVR) would be introduced as the most prevalent power quality problems and most effective voltage sag’s compensators, respectively. Continuously, different parts of DVR structure would be discussed in which control system would be taken into account as the most important part. In this part, after different compensation strategies analysis and with attention to great importance of compensator response in sensitive load protection against the duration of voltage sag, various voltage estimation algorithms would be introduced. Afterwards a novel estimation algorithm would be proposed which has the desirable accuracy and less delay among the mentioned ones. Then a proposed control system based on the proposed algorithm in the fault detection system and pre-fault based symmetrical component strategy would be introduced. Finally the effects of the novel system on asymmetrical voltage sag and swell of the distribution system improvement would be simulated in Matlab/Simulink.
Amir Hossein Izadparast; Mohammad Sadegh Marefat
Morteza Eskandari Ghadi
Sa'eed Hassanzadeh; Kaveh Niayesh; Hossein Mohseni; Amir Abbas Shayegani Akmal
Fariborz Jolai; Reza Tavakolli Moghaddam; Jafar Razmi; Pedaram Sahba
Abstract
In this paper, a supplier-retailer transportation system is investigated as a two-echelon environment. There is a single location in each echelon; the unique supplier at the first echelon has to replenish the retailer's warehouse at the second echelon. By the way, the shortage situation should be avoided. ...
Read More
In this paper, a supplier-retailer transportation system is investigated as a two-echelon environment. There is a single location in each echelon; the unique supplier at the first echelon has to replenish the retailer's warehouse at the second echelon. By the way, the shortage situation should be avoided. For this situation, a model is provided based on the traditional EOQ model. The inventory costs, ordering costs, transportation cost, etc. are considered in this model. Multistage shipment during each ordering period with a specific number of vehicles is allowed in the proposed model. The model's decisions involved in managing the system include design decision (i.e., optimized number of required vehicles), as well as operation decision (i.e., optimized order quantity and number of trips and transportation stages). A solution algorithm is proposed for the proposed model and implemented with C#.Net which is available and applicable on the website, namely www.PedramSahba.com. A numerical example and sensitivity analysis are presented for exposing the model and algorithm capability and then verifying and validating the model.
Hossein Abolghasemi; Hadis Khakbaz
Abstract
1,3-Butadiene, BD is produced from C4-cut by extractive distillation. The separation of 1,3-Butadiene from C4-cut is not possible through the conventional distillation processes, because several mixtures have consisted of close boiling points constituents and make azeotrope. The BASF extraction distillation ...
Read More
1,3-Butadiene, BD is produced from C4-cut by extractive distillation. The separation of 1,3-Butadiene from C4-cut is not possible through the conventional distillation processes, because several mixtures have consisted of close boiling points constituents and make azeotrope. The BASF extraction distillation process in BD unit of Jam and Amirkabir Petrochemical Company improves the relative volatilities of components by addition of a high boiling point solvent (namely N- methylpyrrolidone, 8.3%wt H2O). With respect to high mass ratio of total solvent to feed, the solvent has significant role in separation. In this study, extractive distillation system was simulated with the HYSYS3.1 software to investigate the effect of the temperature and as well as that of feed entry stage of the solvent on the separation. It was found that; the reduction of solvent temperature had no considerable effect on products’ specifications, but rather, it could minimize the solvent rate.
Amin Ghodousian; Ali Babalhavaeji; Elnaz Bashir
Ehsan Khademi; Heshmatollah Haghighat
Abstract
This paper describes an upper bound analysis of cold forward extrusion of spur gears with modified tooth profile. Spur gear geometrical parameters such as module, number of teeth, pressure angle, bore radius and addendum modification factor were input to a computer program written in Visual Basic. Then ...
Read More
This paper describes an upper bound analysis of cold forward extrusion of spur gears with modified tooth profile. Spur gear geometrical parameters such as module, number of teeth, pressure angle, bore radius and addendum modification factor were input to a computer program written in Visual Basic. Then spur gear, billet and extrusion die cavity were modeled automatically in SolidWorks. For upper bound analyses, half pitch of a tooth was considered as a deformation unit and it has been divided into twelve regions and it is assumed that material flow in each region is axisymmetric. Comparison between present theoretical results and the experimental data of other researchers’ work were carried out to illustrate the validity of this proposed model. Finally effects of various parameters on the extrusion load were studied.
P. Jeyanthi
M. Dharmalingam; R. Udaya Suriya
Abstract
A fuzzy graph is a symmetric binary fuzzy relation on a fuzzy subset. The concept of fuzzy sets and fuzzy relations was introduced by L.A.Zadeh in 1965\cite{zl} and further studied\cite{ka}. It was Rosenfeld\cite{ra} who considered fuzzy relations on fuzzy sets and developed the theory of fuzzy graphs ...
Read More
A fuzzy graph is a symmetric binary fuzzy relation on a fuzzy subset. The concept of fuzzy sets and fuzzy relations was introduced by L.A.Zadeh in 1965\cite{zl} and further studied\cite{ka}. It was Rosenfeld\cite{ra} who considered fuzzy relations on fuzzy sets and developed the theory of fuzzy graphs in 1975. The concepts of fuzzy trees, blocks, bridges and cut nodes in fuzzy graph has been studied\cite{mss}. Computing chromatic sum of an arbitrary graph introduced by Kubica [1989] is known as NP-complete problem. Graph coloring is the most studied problem of combinatorial optimization. As an advancement fuzzy coloring of a fuzzy graph was defined by authors Eslahchi and Onagh in 2004, and later developed by them as Fuzzy vertex coloring\cite{eo} in 2006.This fuzzy vertex coloring was extended to fuzzy total coloring in terms of family of fuzzy sets by Lavanya. S and Sattanathan. R\cite{sls}. In this paper we are introducing \textquotedblleft Just Chromatic excellence in fuzzy graphs\textquotedblright.
