The Effects of Internal and External Stiffeners on Hysteretic Behavior of Steel Beam to CFT Column Connections
Mehran
Seyed Razzaghi
Civil Engineering and Surveying,, Qazvin Branch Islamic Azad University
author
Ramin
Esfandyari
Civil Eng., Islamic Azad University, South Tehran Branch
author
F.
Nateghi
structure, IIEES
author
text
article
2014
eng
This study focuses on performance of H-shaped steel beams to CFT column rigid connections. To this end, the effects of internal and external stiffeners on hysteretic behavior of connections were studied. Comparative numerical analyses carried out on eight different connections. To this end finite element models were prepared using ANSYS and nonlinear cyclic analyses carried out. Results of this study revealed that external stiffeners are key elements to increase ductility and strength of steel beam to CFT column connections. It was also shown that T-shaped stiffeners are the most effective types of external stiffeners for improvement of hysteretic behavior of steel beam to CFT steel column connection.
International Journal of Engineering
Materials and Energy Research Center
1025-2495
27
v.
7
no.
2014
1005
1014
https://www.ije.ir/article_72333_69ad20522c8b3a0b1771db307489751d.pdf
An Improved Automatic EEG Signal Segmentation Method based on Generalized Likelihood Ratio
Hamed
Azami
, IUST
author
Hamid
Hassanpour
author
Mahmoud
Anisheh
ELECRONICS & COMMUNICATION, KNT
author
text
article
2014
eng
It is often needed to label electroencephalogram (EEG) signals by segments of similar characteristics that are particularly meaningful to clinicians and for assessment by neurophysiologists. Within each segment, the signals are considered statistically stationary, usually with similar characteristics such as amplitude and/or frequency. In order to detect the segments boundaries of a signal, we propose an improved method using time-varying autoregressive (TVAR) model, integral, basic generalized likelihood ratio (GLR) and new particle swarm optimization (NPSO) which is a powerful intelligence optimizing. Since autoregressive (AR) model for the GLR method is valid for only stationary signals, the TVAR as a valuable and powerful tool for non-stationary signals is suggested. Moreover, to improve the performance of the basic GLR and increase the speed of that, we propose to use moving steps more than one sample for successive windows in the basic GLR method. By using synthetic and real EEG data, the proposed method is compared with the conventional ones, i.e. the GLR and wavelet GLR (WGLR). The simulation results indicate the absolute advantages of the proposed method.
International Journal of Engineering
Materials and Energy Research Center
1025-2495
27
v.
7
no.
2014
1015
1022
https://www.ije.ir/article_72334_f091a002d31c57edc1065a7f7fc2acdc.pdf
Using a Novel Concept of Potential Pixel Energy for Object Tracking
Gholamreza
Ardeshir
Elect & Computer Engineering, Babol Nooshirvani University of Technology
author
Fazollah
Khakpour
Electronic Engineering, Babol Nooshirvani University of Technology
author
text
article
2014
eng
Abstract In this paper, we propose a new method for kernel based object tracking which tracks the complete non rigid object. Definition the union image blob and mapping it to a new representation which we named as potential pixels matrix are the main part of tracking algorithm. The union image blob is constructed by expanding the previous object region based on the histogram feature. The potential pixels matrix of previous object and union blob are used for locating the target frame to frame. The formula for location of kernel in current frame is in the form of algebra and it does not need iterative process as mean shift tracker. For removing the background information and also the non rigid object changes, we propose to divide the expanding part of union blob to two parts and using distance threshold and similarity criterion for each part. We demonstrate the background removing of proposed method has better performance than the weighting kernel of mean shift tracking. Also the segmentation of object which produces narrow histogram is used for reduces the influence of background. We demonstrated the capability of the proposed method for several image sequences
International Journal of Engineering
Materials and Energy Research Center
1025-2495
27
v.
7
no.
2014
1023
1032
https://www.ije.ir/article_72335_0dd2a738e98259eedfbd39714a24b105.pdf
Design of IIR Digital Filter using Modified Chaotic Orthogonal Imperialist Competitive Algorithm (RESEARCH NOTE)
MohammadAli
Sharifi
, Islamic Azad University, Qazvin Branch
author
text
article
2014
eng
There are two types of digital filters including Infinite Impulse Response (IIR) and Finite Impulse Response (FIR). IIR filters attract more attention as they can decrease the filter order significantly compared to FIR filters. Owing to multi-modal error surface, simple powerful optimization techniques should be utilized in designing IIR digital filters to avoid local minimum. Imperialist competitive algorithm is an evolutionary algorithm used in solving optimization problems in recent years. It can find global optimum response in a nonlinear searching space. In this paper, performance of chaotic orthogonal imperialist competitive algorithm has been improved through some variations in it. Then, this modified algorithm has been applied in designing IIR digital filters and their performance has been compared to some evolutionary algorithms.
International Journal of Engineering
Materials and Energy Research Center
1025-2495
27
v.
7
no.
2014
1033
1040
https://www.ije.ir/article_72336_159edac126c78ab569dd372df9821277.pdf
A Novel Fuzzy Based Method for Heart Rate Variability Prediction
Hossein
Gholizade-Narm
Electrical and Robotic, University of Shahrood
author
Mohammad Reza
Shafiee
Electrical, Shahrood
author
text
article
2014
eng
Abstract In this paper, a novel technique based on fuzzy method is presented for chaotic nonlinear time series prediction. Fuzzy approach with the gradient learning algorithm and methods constitutes the main components of this method. This learning process in this method is similar to conventional gradient descent learning process, except that the input patterns and parameters are stored in memory as a look-up table after upgrade. In the testing phase according to input patterns, the nearest neighbors and the weights corresponding to the test pattern, similar patterns are extracted from memory. Eventually by extracted weights and input pattern, prediction is performed. In order to validate the proposed method for predicting, the Mackey-Glass, Lorenz and biological Heart Rate Variability (HRV) time series is used. Finally, results of proposed method with the conventional methods of time-series prediction are also compared. The results demonstrate the capability of proposed method in chaotic time series prediction.
International Journal of Engineering
Materials and Energy Research Center
1025-2495
27
v.
7
no.
2014
1041
1050
https://www.ije.ir/article_72337_e18535183936b997270355f957764e49.pdf
Zone-3 Impadance Reach Setting of Distance Relays by Including In-feed Current Effects in an Adaptive Scheme
Mehdi
Azari
Electerical Engineering, University of Zanjan
author
text
article
2014
eng
The undesired operation of zone 3 may be one of the most conspicuous protective relay features due to the incorrect zone 3 relay operations which have been conducive to the severity of blackouts. Therefore, determining the accurate zone 3 setting of the distance relay is deemed to be necessary. This paper focuses on the development of a new technique for calculating zone-3 setting of distance relays. The proposed technique utilizes impedance seen by distance relays in order to compute zone-3 setting of the relays when faults are modeled on the reach of zone-2 of primary distance relays for the maximum and minimum generation outputs of the power system. The new technique is also improved to be used in an adaptive protection system. The technique and its adaptive version are applied to the IEEE 30-bus test system under different operating circumstances to reveal its robust performance. System simulation studies show that the proposed scheme is able to increase the reach of zone-3 relays without causing mis-coordination problems. Therefore, the two main requirements of the protection system, namely security (without causing coordination) and simultaneity, would be satisfied.
International Journal of Engineering
Materials and Energy Research Center
1025-2495
27
v.
7
no.
2014
1051
1060
https://www.ije.ir/article_72338_48ac7bcf7a6f42f3eb77d0d1a9d9ce11.pdf
Radial Basis Neural Network Based Islanding Detection in Distributed Generation
Mehrdad
Tarafdar Hagh
Faculty of Electrical and Computer Engineering, University of Tabriz, Tabriz-IRAN
author
NORADIN
GHADIMI
DEPARTMENT OF ENGINEERING, DEPARTMENT OF ELECTRICAL ENGINEERING, ARDABIL BRANCH, ISLAMIC AZAD UNIVERSITY ARDABIL, IRAN
author
text
article
2014
eng
This article presents a Radial Basis Neural Network (RBNN) based islanding detection technique. Islanding detection and prevention is a mandatory requirement for grid-connected distributed generation (DG) systems. Several methods based on passive and active detection scheme have been proposed. While passive schemes have a large non detection zone (NDZ), concern has been raised on active method due to its degrading power quality effect. The main emphasis of the proposed scheme is to reduce the NDZ to as close as possible and to keep the output power quality unchanged. The proposed algorithm is compared with the widely used rate of change of frequency relays (ROCOF) and found working effectively in the situations where ROCOF fails. This approach utilizes rate of change of frequency at the target distributed generation location and fed to the radial basis neural network for intelligent islanding detection. Hence a better reliability is provided. This approach utilizes the artificial neural network (ANN) as a machine learning technology for processing and analyzing the large data sets provided from network simulations using MATLAB software. To validate the feasibility of this approach, the method has been validated through several conditions and different loading, switching operation, and network conditions. Simulation studies showed that the RBNN-based algorithm detects islanding situation accurate than other islanding detection algorithms. Moreover, for those regions which are in need of a better visualization, the proposed approach would serve as an efficient aid such that the mains power disconnection can be better distinguished
International Journal of Engineering
Materials and Energy Research Center
1025-2495
27
v.
7
no.
2014
1061
1070
https://www.ije.ir/article_72339_443252caafb078cec3b7d942927ee494.pdf
Perfect Tracking of Supercavitating Non-minimum Phase Vehicles Using a New Robust and Adaptive Parameter-optimal Iterative Learning Control
Reza
Ghaderi
of Control Engineering, Shahid Beheshti University
author
Abolfazl
Ranjbar
Control, Babol Noshirvani university of Technology
author
Meisam
Yahyazadeh
Electrical Engineering, Vali-e-Asr University of Rafsanjan
author
text
article
2014
eng
In this manuscript, a new method is proposed to provide a perfect tracking of the supercavitation system based on a new two-state model. The tracking of the pitch rate and angle of attack for fin and cavitator input is of the aim. The pitch rate of the supercavitation with respect to fin angle is found as a non-minimum phase behavior. This effect reduces the speed of command pitch rate. Control of such non-minimum phase in a specific time interval and improving the speed response with respect to fin control reaction is still an open problem. To overcome the problem a feed-forward control is proposed to apply on the cavitator as a control in the feed-forward configuration. The idea of this paper is to provide a certain signal for the cavitator in order to improve the tracking performance in presence of uncertainty using iterative learning control. Moreover, this paper proposes a new method based on parameter-optimal iterative learning control to solve a perfect tracking problem of systems for indefinite (not sign-definite) system. This technique provides an updating control law through applying adaptive Lyapunov gain for monotonic zero convergence of tracking error in sense of 2-norm. The simulation results verify performance and robustness of the proposed modification of iterative learning control in comparison with classical controller of the supercavitating vehicle.
International Journal of Engineering
Materials and Energy Research Center
1025-2495
27
v.
7
no.
2014
1071
1080
https://www.ije.ir/article_72340_8d101815778e34688ebc83dde1107991.pdf
An Inventory Model for Deteriorating Items Using Vendor-Managed Inventory Policy
Leila
Daneshfar
Industral Engineering, K. N. Toosi University of Technology
author
Mostafa
Setak
, K. N. Toosi University of Technology
author
text
article
2014
eng
In recent researches, vendor managed inventory (VMI) policy is rarely considered for deteriorating items. This study considered the supply chain partner’s collaboration via a VMI system and provided an EOQ model for a two-level supply chain (single supplier - single retailer) to examine the inventory management proceedings for VMI and non-VMI supply chains. By a new approach in modeling, the equations are simplified. The demand is stock-dependent and deterioration and backlogging rates are assumed to be constant. A comparison between the cost of two mentioned cases is done in this article. The results of analytical examination of inventory costs with and without VMI show that VMI system in our proposed model always has the ability to reduce total costs of the supply chain and is always better than the traditional one. Some numerical examples and sensitive analysis are also given to illustrate the application of the proposed model.
International Journal of Engineering
Materials and Energy Research Center
1025-2495
27
v.
7
no.
2014
1081
1090
https://www.ije.ir/article_72341_f365cce2b2b3a26712b7b561789e7a7c.pdf
Train Scheduling Problem with Consideration of Praying Constraint as an Application of Job Shop Scheduling Problem
Amin
Jamili
, Tehran
author
text
article
2014
eng
The present paper extends the idea of job shop scheduling problem with resting constraints to the train scheduling problem with the Muslim praying considerations. For this purpose, after proposing the new mathematical model, a heuristic algorithm based on the Electromagnetism-Like algorithm (EM) which is well adjusted to scheduling problems is employed to solve the large-size practical cases. The effectiveness of the proposed algorithm is then validated by comparing with optimum solution using small-size instances and simulated annealing algorithm, and Particle swarm Optimization (PSO) using medium and large-size instances. At the end a practical case from Iranian railway network is studied and the results are reported.
International Journal of Engineering
Materials and Energy Research Center
1025-2495
27
v.
7
no.
2014
1091
1098
https://www.ije.ir/article_72342_33c0d1274196f656cd8c23b8129c4a42.pdf
An Iterative Decision Rule to minimize cost of Acceptance Sampling Plan in Machine Replacement Problem
Parvin
Abdollahi
Industral Engineering, Yazd University
author
Mohsen
Sheikh Sajadieh
, Amirkabir University of Technology
author
text
article
2014
eng
In this paper, we presented an optimal iterative decision rule for minimizing total cost in designing a sampling plan for machine replacement problem using the approach of dynamic programming and Bayesian inferences. Cost of replacing the machine and cost of defectives produced by machine has been considered in model. Concept of control threshold policy has been applied for decision making. If the probability of producing a defective was more than a control threshold the machine is replaced otherwise its quality will be accepted and continues its production. A Numerical example along with sensitivity analysis is performed to show the application of proposed methodology.
International Journal of Engineering
Materials and Energy Research Center
1025-2495
27
v.
7
no.
2014
1099
1106
https://www.ije.ir/article_72343_e1f3101495a8e8cbaf1a329481eaba1f.pdf
EOQ Model with Cash Flow Oriented and Quantity Dependent Under Trade Credits (TECHNICAL NOTE)
AMIT
UNIYAL
Mathematics, Uttaranchal Unicersity
author
RAKESH
TRIPATHI
Mathematics, Graphic Era University, Dehradun
author
text
article
2014
eng
Inventory models in which the demand rate dependents on the stock- dependent are based on the common real- life observation that greater product availability tends to stimulate more sales. In this study we develop an inventory model to determine an optimal ordering policy for quantity dependent demand rate and time dependent holding cost items with delay in payments permitted by the supplier under inflation and time discounting. Mathematical models have been derived under two situations i.e. Case I: cycle time greater than or equal to permissible delay period. Case II: cycle time less than permissible delay period. In this mathematical model we obtain the optimal cycle time and optimal payment time so that the annual total relevant cost is minimized. Finally numerical example is given to illustrate the proposed model.
International Journal of Engineering
Materials and Energy Research Center
1025-2495
27
v.
7
no.
2014
1107
1112
https://www.ije.ir/article_72344_004ff9b07e66da3070d5898600f9e2e1.pdf
Modeling the Time Windows Vehicle Routing Problem in Cross-Docking Strategy Using Two Meta-Heuristic Algorithms
Ali
Sadri Esfahani
Industrial Engineering, Science and Art University, Yazd, Iran
author
M.B.
Fakhrzad
industrial engineering, Yazd University
author
text
article
2014
eng
In cross docking strategy, arrived products are immediately classified, sorted and organized with respect to their destination. Among all the problems related to this strategy, the vehicle routing problem (VRP) is very important and of special attention in modern technology. This paper addresses the particular type of VRP, called VRPCDTW, considering a time limitation for each customer/retailer. This problem is known as NP-hard problem. Two meta-heuristic algorithms based on the Tabu search (TS) algorithm and variable neighborhood search (VNS) are proposed for its solution. These algorithms are designed for real-world cases and can be generalized to the more complex models such as those which deliveries can be specified in a split form. The proposed TS algorithm also offers a candidate list strategy which has no limitation for the number of nodes and vehicles. A computational experiment is performed to verify our presented algorithms. Through computational experiments, it is indicated that the proposed TS algorithm performs better than VNS algorithm in both aspects of the total cost and computation time.
International Journal of Engineering
Materials and Energy Research Center
1025-2495
27
v.
7
no.
2014
1113
1126
https://www.ije.ir/article_72345_e166781eb35b615116e58fbc7e443867.pdf
Characterization of TiN, CrN and (Ti, Cr) N Coatings Deposited by Cathodic ARC Evaporation
mahdi
akbarzadeh
Department of Materials Engineering, Isfahan University of Technology
author
text
article
2014
eng
In this investigation PVD Ti-Cr)N coatings were deposited on hardened and tempered tool steel substrates using reactive arc evaporation. Physical and mechanical properties of coatings such as roughness, thickness, phase composition, hardness and modulus young and coefficient friction were evaluated. Phase compositions were studies by X-ray diffraction method. The surface microstructure and morphology were studied using scanning electron microscope (SEM) and coating compositions were determined by energy dispersive spectroscopy (EDS). Mechanical Properties were determined by Nano indentation. The friction behavior of the coatings were investigated using ball-on-disc test under normal loads of 7 .The results showed that(Ti, Cr)N and TiN coating had only one solid solution cubic phase While CrN coatings had Hexagonal Cr2N and Cubic CrN phases. Average grain size of the coatings was found in the range of 14 to 20 nm. Physical-Mechanical Properties of CrN and (Ti, Cr)N and TiN coatings, respectively, increases. Mechanical behavior of the (Ti, Cr)N coatings is related to Ti content and hardness decreases with decreasing Ti content.
International Journal of Engineering
Materials and Energy Research Center
1025-2495
27
v.
7
no.
2014
1127
1132
https://www.ije.ir/article_72346_d3562e2ce9dcdf5c277721cbdb9b82c0.pdf
Effect of TiO2 Nanofiber Density on Organic-Inorganic Based Hybrid Solar Cells (RESEARCH NOTE)
ali
bakhe kasaeian
Renewable Energies, University of Tehran
author
Arezou
Boroumandnia
Renewable Energies, University of Tehran
author
Alireza
Nikfarjam
Nanotechnology, University of Tehran
author
text
article
2014
eng
Abstract In this work, a comparative study of hybrid solar cells based on P3HT and TiO2 nanofibers was accomplished. Electrospinning, a low cost production method for large area nanofibrous films, was employed to fabricate the organic-inorganic hybrid solar cells based on poly (3-hexylthiophene) and TiO2 nanofibers. The performance of the hybrid solar cells was analyzed for four density levels of TiO2 nanofibers, which resulted in the average power conversion efficiency of about 0.0134 % under AM 1.5 simulated illuminations (100 mWcm-2). It is found that the higher densities of TiO2 lead to more interfaces area and generating exciton, so the power conversion efficiency will be increased till the active layer thickness is about 400 nm but with increasing thickness more than 400 nm the increasing density hasn’t positive effect.
International Journal of Engineering
Materials and Energy Research Center
1025-2495
27
v.
7
no.
2014
1133
1138
https://www.ije.ir/article_72347_9adf09f17be1441c5c1218bc139419fd.pdf
Uncertainties due to Fuel Heating Value and Burner Efficiency on Performance Functions of Turbofan Engines Using Monte Carlo Simulation
M
Khodadadi
Mechanical Engineering, Babol Noshirvani university of Technology
author
Admin
Kazemi
Mechanical Engineering, Babol Noshirvani university of Technology
author
Mofid
Gorji
Mechanical Engineering, Babol Noshirvani university of technology
author
text
article
2014
eng
In this paper, the impacts of the uncertainty of fuel heating value as well as the burner efficiency on performance functions of a turbofan engine are studied. The mean value and variance curves for thrust, thrust specific fuel consumption as well as propulsive, thermal and overall efficiencies are drawn and analyzed, considering the aforementioned uncertainties based on various Mach numbers at a number of flying altitudes in order to yield a more accurate prediction of values of performance functions. The results of this study can be of essential significance for an optimal and robust design of turbofan engines. This study is done employing Monte Carlo Simulation method which is a probabilistic analysis method.
International Journal of Engineering
Materials and Energy Research Center
1025-2495
27
v.
7
no.
2014
1139
1148
https://www.ije.ir/article_72348_05f5639d5b79e2a563eb027363625f2d.pdf
Experimental Investigation of Thermal Performance in an Advanced Solar Collector with Spiral Tube
Alireza
Hajipour
Mechanical Engineering, Department of Mechanical Engineering, College of Engineering, Central Tehran Branch, Islamic Azad University, Tehran, Iran.
author
Ehsan
Shojaeezadeh
Mechanical Engineering, Yasouj University
author
S. Kobra
Asadi Yousef-abad
Mechanical Engineering, Young Researchers Club, Yasuj Branch, Islamic Azad
author
Koorosh
Goudarzi
Mechanical Engineering, Yasouj University
author
text
article
2014
eng
This paper reports the thermal performance of a new cylindrical solar collector based on an experimental investigation with this difference that instead of the collector tube with absorbent coating, coil into a spiral copper tube is placed in the center of the collector. The spiral shape of the tube, heat transfer without disruption or increase the heat transfer area, is increasing. In this case, the centrifugal forces generated secondary flow, increases the coefficient of the convection heat transfer. Another advantage of this type of collector to the flat plate collector, its circular shape that is constantly exposed to sunlight. Measuring cylindrical solar collector inlet and outlet temperatures, on September 6-8, 2012 from 10 AM to 14 PM, the thermal efficiency is between 43.5 to 58.7 percent. The obtained results of this article can be useful for analysis of the solar energy systems.
International Journal of Engineering
Materials and Energy Research Center
1025-2495
27
v.
7
no.
2014
1149
1154
https://www.ije.ir/article_72349_c3f73811c46834ff307b82b4436268a6.pdf
Investigation of the Effects of Pressure Path and Tool Parameters in Hydrodynamic Deep Drawing
Masoomeh
Salahshoor
Mech. Eng., Babol University of Technology
author
text
article
2014
eng
In recent years, hydroforming process has been applied in different industries such as aerospace, automotive and military industries due to its advantages, such as high dimensional accuracy, capability of forming complicated parts and high drawing ratio. Hydrodynamic deep drawing with radial pressure is one type of hydroforming process. In this paper, forming of cylindrical cups in hydrodynamic deep drawing with radial pressure is numerically and experimentally investigated and the effects of significant parameters such as pressure path, punch corner radius and die profile radius on the cup thickness distribution and punch force were studied. The results obtained showed that increasing the pressure affects the thickness reduction in critical regions of cup and from the certain pressure, the pressure does not have a significant effect on the thickness of part. On the other hand, increasing the pressure, increases the force needed for forming the cup. Also, it was found that by increasing the punch corner radius, the cup thickness will be more uniform and maximum punch force does not change. Results of studying the effect of die profile radius on thickness distribution and punch force showed that increasing the die profile radius has a positive effect on the cup thickness distribution and the force needed to form part.
International Journal of Engineering
Materials and Energy Research Center
1025-2495
27
v.
7
no.
2014
1155
1166
https://www.ije.ir/article_72350_885899ba64e7f18b28790455e641390a.pdf