Caren Abrinia; Seyyed Ali Reza Fazli Rad
Masoud Riazi; MOhammad Reza Esfahani
Abstract
In this research, using the Modified Compression Field Theory (MCFT), a new model is proposed to predict the behavior of reinforced concrete coupling beams. The model is able to consider the effects of shear and axial forces and bending moment, simultaneously. The proposed model includes a nonlinear ...
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In this research, using the Modified Compression Field Theory (MCFT), a new model is proposed to predict the behavior of reinforced concrete coupling beams. The model is able to consider the effects of shear and axial forces and bending moment, simultaneously. The proposed model includes a nonlinear shear spring, an axial spring and some nonlinear springs for considering bending deformations. In the experimental part of the research, six specimens with different reinforcing layouts were manufactured and tested. In order to consider the constraining effect of slab diaphragms, three specimens were constrained, axially. The results of the proposed model were compared with the test results reported by other researchers. Good agreement was obtained between the test results and calculated values. The test results of the axially constrained specimens show that axial rigidity may change the behavior of coupling beams, considerably.
Mohsen Kahrom; Behrouz Zafarmand; Ali Farahbod
Mahdi Heidari; Ali Golshani; D. Moazzami; Ali Moeini
Abstract
In this paper we restrict every set splitting problem to the special case in which every set has just three elements. This restricted version is also NP-complete. Then, we introduce a general conversion from any set splitting problem to 3-set splitting. Then we introduce a randomize algorithm, and we ...
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In this paper we restrict every set splitting problem to the special case in which every set has just three elements. This restricted version is also NP-complete. Then, we introduce a general conversion from any set splitting problem to 3-set splitting. Then we introduce a randomize algorithm, and we use Markov chain model for run time complexity analysis of this algorithm. In the last section of this paper we introduce "Fast Split" algorithm.
Dara Moazzami
Abstract
Conceptually graph vulnerability relates to the study of graphintactness when some of its elements are removed. The motivation forstudying vulnerability measures is derived from design and analysisof networks under hostile environment. Graph tenacity has been anactive area of research since the the concept ...
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Conceptually graph vulnerability relates to the study of graphintactness when some of its elements are removed. The motivation forstudying vulnerability measures is derived from design and analysisof networks under hostile environment. Graph tenacity has been anactive area of research since the the concept was introduced in1992. The tenacity T(G) of a graph G is defined as\begin{center} $T(G)=\displaystyle \min_{A\subset V(G)}\{\frac{\mid A\mid +\tau(G-A)}{\omega(G-A)}\}$\end{center}where $\tau(G-A)$ denotes the order (the number of vertices) of alargest component of G-A and $\omega(G-A)$ is the number ofcomponents of G-A. In this paper we discuss tenacity and its properties invulnerability calculation.
Zohre Kiapasha; Iraj Mahdavi; Hamed Fazlollahtabar; Zahra Kiapasha
Abstract
Analyzing eyes performance is essential for effective functioning of human. Therefore, following their motion could help doctors to make quick and accurate diagnoses for disorders like Autism, schizophrenia, or attention deficit hyperactivity disorder. Recently, several studies investigated autism disorder ...
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Analyzing eyes performance is essential for effective functioning of human. Therefore, following their motion could help doctors to make quick and accurate diagnoses for disorders like Autism, schizophrenia, or attention deficit hyperactivity disorder. Recently, several studies investigated autism disorder diagnosis and treatment. Meanwhile, various algorithms have been provided for eye tracking. In this paper, it is intended to identify diagnosis parameters of autism disorder using eye tracking concept. The eye tracking algorithm that has been used in this research is simple and sufficient accurate to appropriate function on videos with varying quality. The direct analysis of gaze and study of the interactions of its features are employed a useful method for diagnosis of autism. For this purpose, two separate groups of ordinary children and children with autism are considered. By tracking their eyes while watching television and performing the necessary analyses then their eye movements are compared and discussed. To identify pupils is face detection Viola Jones algorithm is implemented.
Zeinab Abadi; Seyed Abolfazl Shahzadeh Fazeli; Seyed Mehdi Karbassi
Abstract
The explicitly restarted Arnoldi method (ERAM) can be used to find some eigenvalues of large and sparse matrices. However, it has been shown that even this method may fail to converge. In this paper, we present two new methods to accelerate the convergence of ERAM algorithm. In these methods, we apply ...
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The explicitly restarted Arnoldi method (ERAM) can be used to find some eigenvalues of large and sparse matrices. However, it has been shown that even this method may fail to converge. In this paper, we present two new methods to accelerate the convergence of ERAM algorithm. In these methods, we apply two strategies for the updated initial vector in each restart cycles. The implementation of the methods have been tested by numerical examples. The results show that we can obtain a good acceleration of the convergence compared to original ERAM.
Hadis Shafaei; Rouzbeh Razavi
Abstract
Web recommender systems provide the most appropriate recommendations by analyzing user’s navigation behavior. This recommender system can be considered in different cases, such as e-commerce, search engines, etc. The aim of the proposed approach in this research is to create users’ profiles ...
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Web recommender systems provide the most appropriate recommendations by analyzing user’s navigation behavior. This recommender system can be considered in different cases, such as e-commerce, search engines, etc. The aim of the proposed approach in this research is to create users’ profiles and find their common navigation patterns implicitly. The web log file is utilized to analyze browsing history and discover users' navigation models. This analysis is called web usage mining. This research focused on the K-means algorithm as a cluster, and the neural network as a classification algorithm, along with the recommended Markov model. The innovation of this research is to consider a threshold for the proposed Markov model. The main goal of this research is to create a recommender system based on the Markov model and neural network that provides an acceptable suggestion with high accuracy and precision.
Sajjad Rahmany; Abdolali Basiri; Behzad Salehian
Abstract
In this paper, a new algorithm for computing secondary invariants of invariant rings of monomial groups is presented. The main idea is to compute simultaneously a truncated SAGBI-\G basis and the standard invariants of the ideal generated by the set of primary invariants. The advantage ...
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In this paper, a new algorithm for computing secondary invariants of invariant rings of monomial groups is presented. The main idea is to compute simultaneously a truncated SAGBI-\G basis and the standard invariants of the ideal generated by the set of primary invariants. The advantage of the presented algorithm lies in the fact that it is well-suited to complexity analysis and very easy to implement.
Fatemeh Ganji; Amir Jamali
Abstract
In this study, single machine scheduling with flexible maintenance is investigated with non-resumable jobs by minimizing the weighted number of tardy jobs. It is assumed that the machine stops for a constant interval time during the scheduling period to perform maintenance. In other words, the starting ...
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In this study, single machine scheduling with flexible maintenance is investigated with non-resumable jobs by minimizing the weighted number of tardy jobs. It is assumed that the machine stops for a constant interval time during the scheduling period to perform maintenance. In other words, the starting time of maintenance is the decision variable. By reviewing the literature, we noticed that this problem has not been studied yet. Initially, it is proved that the problem is NP-hard. Then, a mathematical model is proposed and solved by the GAMS software. Because of the long time for solving the problem with an exact method, we develop a heuristic algorithm. To evaluate the efficiency of the proposed algorithm, 696 test problems with different sizes of the problem in the range from 1 to 2000 jobs, are generated. The computational results demonstrate that the average error of solution is 10.93\%.
Christian Barrientos; Sarah Minion
Abstract
A graceful labeling of a graph G of size n is an injective assignment of integers from {0, 1,..., n} to the vertices of G, such that when each edge of G has assigned a weight, given by the absolute di erence of the labels of its end vertices, the set of weights is {1, 2,..., n}. If a graceful labeling ...
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A graceful labeling of a graph G of size n is an injective assignment of integers from {0, 1,..., n} to the vertices of G, such that when each edge of G has assigned a weight, given by the absolute di erence of the labels of its end vertices, the set of weights is {1, 2,..., n}. If a graceful labeling f of a bipartite graph G assigns the smaller labels to one of the two stable sets of G, then f is called an -labeling and G is said to be an α-graph. A tree is a caterpillar if the deletion of all its leaves results in a path. In this work we study graceful labelings of the disjoint union of a cycle and a caterpillar. We present necessary conditions for this union to be graceful and, in the case where the cycle has even size, to be an α -graph. In addition, we present a new family of graceful trees constructed using α-labeled caterpillars.
Mohammad Hosseini Moghaddam; Tahmineh Sahverdi
Abstract
Tipping Point refers to the moment when an adaption or infection sustains itself in network without further external inputs. Until now, studies have mainly focused on the occurrence of the Tipping Point and what it leads to rather than what precedes it. This paper explores the situation leading to the ...
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Tipping Point refers to the moment when an adaption or infection sustains itself in network without further external inputs. Until now, studies have mainly focused on the occurrence of the Tipping Point and what it leads to rather than what precedes it. This paper explores the situation leading to the Tipping Point during a process of diffusion in networks. The core of the debate is to manifest that the process can be introduced as an example of conditionally convergent series and that determining the tipping points’ occurrence is conditional to the arrangement of the series based on Reimann Rearrangement Theorem. Accordingly, the occurrence of curve does not follow a general formulation. That is called indeterminacy since that the predictions about tipping points for any diffusion over the network may include a variety of right answers, although such indeterminacy neither means there is no tipping point nor many.
Mohammad Reza Talaghat; Abdolhossein Jahanmiri
Abstract
This paper presents a study on estimation of heat transfer coefficient and thermal diffusivity parameters by use of analytical solutions and experimental data for regular geometries (infinite slab, infinite cylinder and sphere). Analytical solutions have a broad use in experimentally determining these ...
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This paper presents a study on estimation of heat transfer coefficient and thermal diffusivity parameters by use of analytical solutions and experimental data for regular geometries (infinite slab, infinite cylinder and sphere). Analytical solutions have a broad use in experimentally determining these parameters. These solutions, with use of experimental data, might give a greater advantage over use of other methods, e.g., the lumped system approach or empirical equations. In the present work, the method of finite integral transform (FIT) was used for solutions of governing differential equations. The temperature change at centerline location of cylindrical objects (Aluminum and Brass) were recorded to determine both the thermal diffusivity in a highly agitated water medium and heat transfer coefficient in air and water mediums . Then, with the known slop of the temperature ratio vs. time curve and radius of the cylindrical material, thermal diffusivity value or heat transfer coefficient may be determined. For all experiments, excellent agreement was obtained between the experimental results and the actual data. This method may also be used to find out the precise geometric location of the thermocouples placed in the samples to measure the temperature change. In this research, thermocouple location for a spherical object was determined. This technique would be much faster and easier compared to the other methods used for this objective.
Hatef Hashemi; Ramin Raiszadeh
Abstract
In this research, the effect of friction between the liquid metal and the sand mould wall and the effect of passage of liquid through a vertical bend and through a ceramic filter on the fluid flow and the melt velocity has been studied by measuring the velocity of the melt and direct observation of the ...
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In this research, the effect of friction between the liquid metal and the sand mould wall and the effect of passage of liquid through a vertical bend and through a ceramic filter on the fluid flow and the melt velocity has been studied by measuring the velocity of the melt and direct observation of the liquid flow through the different parts of a naturally-pressurized running system. The friction factor was calculated using the experimental results and it was shown that the friction had a significant effect on the reduction of the melt velocity. The effect of passage of liquid through a vertical bend was measured to be 20% and a filter was estimated to reduce the liquid metal velocity by half (almost half of the effect that was stated in the literature). The design of the running system was slightly altered considering the obtained effect of filter on the melt velocity. The comparison of reliability of the castings obtained by different running systems, using a Weibull statistical method, showed that the altered naturally-pressurized running system produced the most reliable castings and that the effect of the new method of running system design was greater than that of the use of a ceramic filter in the common unpressurized running system.
Arezou Nikseir; Amir Rahimi
Abstract
Beginning with a discussion of energy and exergy analysis definitions, the presented study provides a descriptive mathematical model for energy and exergy analysis for a co-current gas cooling tower. For this purpose using conservation laws of mass, energy and momentum, the variation of temperature and ...
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Beginning with a discussion of energy and exergy analysis definitions, the presented study provides a descriptive mathematical model for energy and exergy analysis for a co-current gas cooling tower. For this purpose using conservation laws of mass, energy and momentum, the variation of temperature and enthalpy of gas and liquid streams are predicted along the tower length and are used in order to calculate the energy and exergy efficiencies. The model validity in prediction of gas and liquid characteristics changing along the tower length was examined against some operating data measured in a commercial cement plant. As a result, it was concluded that in spite of high energy efficiency, the cooling tower has a relatively low exergic efficiency which is because of thermodynamic irreversibilities and entropy production during heat and mass transfers. Also, the effect of some operating parameters including tower diameter, tower length, liquid drops size distribution and water flow rate was investigated on amount of exergy destruction. In all cases the results showed that the exergy of water does not completely absorbed by gas and a notable portion of the exergy is destructed. The result of these investigations may be employed to inform about the true energy potential caring by fluids.
Mehdi Mousavi; Ali Reza Yarahmadi Bafghi; Hamid Reza Bakhshi
Abstract
In the past, rock slope stability analysis were performed either graphically or using a hand-held calculator, but nowadays there are variety of slope stability analysis which can be used according to the field condition and potential failure mode. In 2-D analysis, effect of convex and concave walls are ...
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In the past, rock slope stability analysis were performed either graphically or using a hand-held calculator, but nowadays there are variety of slope stability analysis which can be used according to the field condition and potential failure mode. In 2-D analysis, effect of convex and concave walls are neglected, however concave slopes are believed to be more stable than straight walls due to the lateral restraint provided by material on either sides of a potential failure in a concave slope. In open pit mines with general tendency to increase the wall angle, this point is really important. In this study slope stability of western wall of Sarcheshmeh mine in its extension plan is analyzed using 3-D distinct element method (3DEC). For stability analysis, west wall is divided into three structural regions according to the rock type. Rock and joint strength properties are determined from previous and new laboratory tests. Also in Andesite (dominant rock of the west wall) geometrical properties of joint sets are determined. Consequently Slide5.0 software is used to identify rock mass stability and effect of disturbance factor, underground water, horizontal seismic acceleration and rock type on wall stability. In the next step, the mine geometry is modeled in 3DEC and wall stability is investigated in different locations. Results obtained from 3DEC prove failure of several benches at the toe. Also results show drainage may improve stability in some zones but there would still be smaller failures in the toe.
Bahram Salehi; Mohammad Javad Valadan Zoj; Mohammad Reza Sarajian
Abstract
Hyperspectral data potentially contain more information than multispectral data because of their higher spectral resolution. However, the stochastic data analysis approaches that have been successfully applied to multispectral data are not as effective for hyperspectral data as well. Various investigations ...
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Hyperspectral data potentially contain more information than multispectral data because of their higher spectral resolution. However, the stochastic data analysis approaches that have been successfully applied to multispectral data are not as effective for hyperspectral data as well. Various investigations indicate that the key problem that causes poor performance in the stochastic approaches to hyperspectral data classification is inaccurate class parameters estimation. It has been found that the conventional approaches can be retained if a preprocessing stage is established before feature extraction procedure in classification of hyperspectral data. For preprocessing stage it has been proposed two steps in this paper including dimensionality reduction and class separability improvement. Sequential Parametric Projection Pursuit was used for dimensionality reduction because of its special characteristics. Projection Pursuit algorithm performs the computation of class parameter estimation at a lower dimensional space, giving better parameter estimation. For class separability improvement a lowpass filter has been used after dimensionality reduction. This paper shows that for different number of features, classification accuracy is improved when the preprocessing stage is applied.
Yousef Ghorbani; Manouchehr Oliazadeh; Ahmad Reza Shahverdi; Atena Pirayegar
Ali Reza Azmoude Ardalan; Abdorreza Safari; Abbas Ali Jom'egi
Mohammad Reza Soltani; Ali Pouli Baba'ee Mamghani
Mohsen Najimi Varzaneh; Hossein Rajaie
Abstract
Large deformation causing damage due to uplift force is generated in buried pipeline located in shallow trenches in marshes and saturated soils. In this paper, existing common methods of pipeline anchorage are discussed and considering advantages and disadvantages of these methods, a new method of pipeline ...
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Large deformation causing damage due to uplift force is generated in buried pipeline located in shallow trenches in marshes and saturated soils. In this paper, existing common methods of pipeline anchorage are discussed and considering advantages and disadvantages of these methods, a new method of pipeline anchorage are studied and presented. In this new developed method, geo-textile materials are used for anchorage of large diameter pipeline. Laboratory and field experimental study are developed and effective parameters are deliberated considering load–displacement curves. Finally, a field study on a 30" diameter gas pipe is performed to admit the laboratory tests. Considering the laboratory and field study results, the anchorage of pipeline using geo-textile is recommended for anchorage of buried pipeline in marshes and saturated soils.
Fa'egheh Amirzadeh; Mahmoud Kamare'i; Gholamreza Dadashzadeh
Abstract
In this paper a novel method for computing the radiation pattern and also the input impedance of a planar rectangular micro-strip antenna array with consideration of mutual coupling and mutual impedance is presented. Each two triangles with a common edge make an Edge element or RWG. Any such edge element ...
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In this paper a novel method for computing the radiation pattern and also the input impedance of a planar rectangular micro-strip antenna array with consideration of mutual coupling and mutual impedance is presented. Each two triangles with a common edge make an Edge element or RWG. Any such edge element is considered as an infinitesimal dipole. The electrical currents over each dipole can be calculated by solving an electric field integral equation (EFIE), using the method of moments. Using the resulting surface currents and considering the mutual coupling effect between the elements, the radiation pattern of the whole array is obtained employing a new method, which we call it “active element pattern based on RWG edge element”. Moreover, using the above mentioned model for the edge elements and also considering the mutual impedance between the elements, the input impedance of the array is now calculated.
Abbas Majdi; Siavash Litkouhi; Mehdi Hajian Hosseinabadai
Abstract
In deep mixing method lime or cement and or a combination of the two are mixed with in-situ soils by means of an auger to improve the strength properties of the soils. Strength of the improved soils may be evaluated in different ways, so that, the uniaxial compressive strength assessment is one of the ...
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In deep mixing method lime or cement and or a combination of the two are mixed with in-situ soils by means of an auger to improve the strength properties of the soils. Strength of the improved soils may be evaluated in different ways, so that, the uniaxial compressive strength assessment is one of the most commonly used methods. The project site is located at Zaytoon 2 in Bandar Abbas City. In order to make the excavation of the sandy soils feasible and to mitigate the liquefaction potential hazard, deep mixing method was employed. In an attempt to establish a relation between strength properties of cement grout (cement + water) and the soil-cement mixed (cement grout + soils) two types of grouts; "A" and "B" with different admixtures were used. Type "A" with a water/cement ratio (w/c) = 0.8, where no bentonite was added, whilst in grout Type "B" the ratio w/c = 1.0, with 3% (by cement weight) and bentonite was added. In order to evaluate the strength properties of the grout and soil-cement, some representative samples were obtained. The 7 and 14 days cured samples were tested under uniaxial compressive loading condition. Several in-situ samples were also taken for reliability and quality control purposes. Comparative study of the results revealed that the rate of strength increase in grout type "B", due to using bentonite, is low as compared with the grout type "A". The relationship of uniaxial compressive strength and modulus of elasticity with both density and with the final strain of soil-cement mixed were investigated. Finally, based on the results of uniaxial compressive strength of cement grout, an empirical equation to predict the uniaxial compressive strength of soil-cement mixed has been suggested. The predicted strength was compared with the strength of in-situ samples. It has proven that the prediction method can be used as a reliable approach for determination of the uniaxial compressive strength of soil-cement mixed.
Faramarz Faghihi; Hossein Heydari; Vahid Abbasi
Abstract
The higher frequency transient signals generated as a result of a power system fault or disturbance provide the basis for an alternative approach to power system containing connectors and cables result in unsuitable operation of the system. However one major challenge is the need to ensure that the transients ...
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The higher frequency transient signals generated as a result of a power system fault or disturbance provide the basis for an alternative approach to power system containing connectors and cables result in unsuitable operation of the system. However one major challenge is the need to ensure that the transients to be neutralized by electromagnetic compatibility (EMC) issues and cabling routes.
This paper proposes novel method for optimal cable routings and connectors; a combinatorial design Algorithm, to choose the best path when two or more physical paths are available. The best path from EMC point of view can be chosen based upon various criteria such as monetary cost minimization, voltage drop and quality (electromagnetic compatibility) parameters. This paper initially provides a numerical 2D and 3D resolution of the problems of radiation generated by current sources. The approach is based on the finite element method (FEM) associated with absorbing boundary conditions. The presented model makes it possible to consider wave propagation and their effects in heterogeneous mediums in transient which can be applied in EMC for the simulation of radiation. First, the formulations of the electromagnetic problem are detailed. The simulation results are used for the cabling routes with respect to undesirable field distribution in the specified regions. Finally by the use of Multi Criteria Decision Making (MCDM) optimal routes for cabling based upon the above mentioned criteria are chosen. The proposed method is successfully implemented on 25kA current injection transformer system".
Mehdi Ghassemieh; Vahid Zeynoddini Meymand
Abstract
The use of steel flush end-plate moment connection is practiced in the construction of the light steel frames around the world particularly in parts of Europe and US. In the past most research was concentrated on studying the behavior of the flush end-plate connection subjected to only monotonic type ...
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The use of steel flush end-plate moment connection is practiced in the construction of the light steel frames around the world particularly in parts of Europe and US. In the past most research was concentrated on studying the behavior of the flush end-plate connection subjected to only monotonic type loadings. The majority of that research carried out such investigation through experimental programs. Although experimental results reveal the behavior of such system to some extent, but the cost of using the numerical techniques such as finite element for the analysis appears to be much less and takes not long time and effort in comparison with the test program.
In this study, the numerical behavior of flush end-plate connection using finite element method is investigated. The moment-rotation characteristic of the connection when subjected to cyclic loading is obtained. The numerical results obtained in this study are compared with the experimental results of other researchers. Some of the pertinent parameters effecting on the overall behavior of the connection as well as the design equations obtained from the method of yield line analysis are discussed.
