@article { author = {Arjmandi, M and Pourafshari Chenar, M and Peyravi, M and Jahanshahi, M and Arjmandi, A and Shokuhi Rad, A}, title = {Interpreting the CO2 adsorption on functionalized organic group of IRMOF-1: A B3LYP DFT based study}, journal = {International Journal of Engineering}, volume = {31}, number = {9}, pages = {1473-1479}, year = {2018}, publisher = {Materials and Energy Research Center}, issn = {1025-2495}, eissn = {1735-9244}, doi = {}, abstract = {Density Functional Theory (DFT) calculations techniques in terms of energetic and electronics properties are used to study CO2 adsorption in NH2-, OH-, COOH-, Br- and Cl-functionalized IRMOF-1. Geometry optimization, density of states (DOS), and energy analyses were performed to investigate the adsorption phenomenon. First, we examined the geometrical as well as the electronic structures of functionalized IRMOF-1 (actually functionalized H2BDC as representative section) before and after interaction with CO2, in order to compare and comprehend the relationship between their chemical structure and their related properties. The binding properties have been calculated and analyzed theoretically for pristine H2BDC and X-H2BDC as well as their complex forms with CO2 molecule in terms of binding energies, band structures, total density of states, and Mulliken charges. The finding showed larger interaction energy in COOH-H2BDC (-22.3125 kJ/mol) and somewhat in OH-H2BDC (-12.8625 kJ/mol) and NH2-H2BDC (-12.6000 kJ/mol) complexes compared to less interaction energies in Br-H2BDC (-10.2375 kJ/mol) and Cl-H2BDC (-6.0375 kJ/mol) complexes. The type of interaction between CO2 with pristine H2BDC and X-H2BDC was studied with understanding the HOMO and LUMO energies.}, keywords = {IRMOF,1,CO2 capture,Functionalization,DFT}, url = {https://www.ije.ir/article_73300.html}, eprint = {https://www.ije.ir/article_73300_68af936ad128b995e9f7e66ecc06b70c.pdf} } @article { author = {Tiara, T and Agustina, T. E and Faizal, M}, title = {The Effect of Air Fuel Ratio and Temperature on Syngas Composition and Calorific Value Produced from Downdraft Gasifier of Rubber Wood-Coal Mixture}, journal = {International Journal of Engineering}, volume = {31}, number = {9}, pages = {1480-1486}, year = {2018}, publisher = {Materials and Energy Research Center}, issn = {1025-2495}, eissn = {1735-9244}, doi = {}, abstract = {Rubber wood (Ficus elastica) is one the biomass waste that can be used as raw material for a gasification process and has a calorific value of 4,069 cal/gram. Gasification is a process to convert a solid fuel to syngas (CO, CH4, and H2) through a combustion process using limited air between 20% to 40% of air stoichiometry. Depending on the direction of airflow, the gasifiers are classified as updraft, downdraft, and cross-flow. The downdraft type of gasifier produces a lower tar content than updraft type. The gasification of rubber wood and rubber wood-coal mixture were carried out in this research. The purpose of the research is to determine the effect of Air Fuel Ratio (AFR) and temperature on calorific value and composition of syngas by using a downdraft gasifier. The variations of AFR were 0.64, 0.95, and 1.26. The temperature of gasification was varied between 600ºC-1000ºC. The result showed that the percentage of CO, H2, and CH4 decreased with increasing of AFR, so decreasing the calorific value. The calorific value of syngas increased along with the temperature. The use of coal in the gasification process can maintain stable combustion the temperatures and increase the syngas produced. The best-operating conditions in the research occurred at AFR of 0.64, the temperature of 800ºC and use of coal as a stabilizer. At this condition, the percentage of syngas of 35.95% of CO, 15.95% of H2, 9.38% of CH4, and caloric value of 9,420 MJ/m3 was obtained.}, keywords = {Rubber wood,gasification,Downdraft gasifier,Syngas,LHV}, url = {https://www.ije.ir/article_73283.html}, eprint = {https://www.ije.ir/article_73283_035e67c29812ef57df087a90598bfefd.pdf} } @article { author = {Ardeshir, A and Farnood Ahmadi, P and Bayat, H}, title = {A Prioritization Model for HSE Risk Assessment Using Combined Failure Mode, Effect Analysis, and Fuzzy Inference System: A Case Study in Iranian Construction Industry}, journal = {International Journal of Engineering}, volume = {31}, number = {9}, pages = {1487-1497}, year = {2018}, publisher = {Materials and Energy Research Center}, issn = {1025-2495}, eissn = {1735-9244}, doi = {}, abstract = {The unavailability of sufficient data and uncertainty in modeling, some techniques, and decision-making processes play a significant role in many engineering and management problems.  Attain to sure solutions for a problem under accurate consideration is essential.  In this paper, an application of fuzzy inference system for modeling the indeterminacy involved in the problem of HSE risk assessment is presented. For this purpose, Failure Mode and Effect Analysis, one of the most practical techniques in reliability programs in HSE risk assessment is integrated with Fuzzy Inference System. The proposed model is executed according to the Mamdani algorithm and fuzzy logic toolbox of MATLAB software. With respect to a case study, a comparison between the proposed model and common FMEA risk assessment approach is made for prioritization of HSE risks. Based on the proposed model, falling and slipping of workers is the first serious risk (RPN= 0.7938) and inconsiderable risk is skin injury (RPN= 0.0223). Ultimately, by applying the method on a case study, the results indicate that the proposed model by considering economic aspects as an intelligent risk evaluation tool provides more detailed and precise results.}, keywords = {FMEA,Fuzzy inference system,HSE risk assessment,Mamdani algorithm,Construction Industry}, url = {https://www.ije.ir/article_73284.html}, eprint = {https://www.ije.ir/article_73284_d82673d474337bfffdb58c61ed31697c.pdf} } @article { author = {Lin, W. and Wang, H. and Zhang, Y.}, title = {Comparison of Two Computational Microstructure Models for Predicting Effective Transverse Elastic Properties of Unidirectional Fiber Reinforced Composites}, journal = {International Journal of Engineering}, volume = {31}, number = {9}, pages = {1498-1504}, year = {2018}, publisher = {Materials and Energy Research Center}, issn = {1025-2495}, eissn = {1735-9244}, doi = {}, abstract = {Characterization of properties of composites has attracted a great deal of attention towards exploring their applications in engineering. The purpose of this work is to study the difference of two computational microstructure models which are widely used for determining effective transverse elastic properties of unidirectional fiber reinforced composites. The first model based on the classic mechanics of materials permits free unloaded opposite boundaries in the unite cell, while the second one introduces straight-edge constraints in the unite cell to represent interactions of neighboring cells during deformation. The two approaches are firstly verified by the periodic circular hole problems. Then three microstructures are taken into consideration including the circular fibers, square fibers, and circular fiber clusters periodically embedded in the matrix and solved by finite element analysis. A comparison of the numerical results demonstrates that the two computational models with and without periodic conditions can give different predictions on the effective elastic properties of composite for both low and high fiber volume fractions, especially for the effective Poisson’s ratio of composite. Applying periodic straight-edge constraints after deformation can prevent any over-constrained conditions in the numerical model and give more stable results.}, keywords = {Fiber,reinforced composite,effective transverse elastic properties,free boundary,straight,edge boundary,Finite Element}, url = {https://www.ije.ir/article_73285.html}, eprint = {https://www.ije.ir/article_73285_05ce17000cd86904b5b0815940041cfe.pdf} } @article { author = {Kamrani Moghaddam, P and Manafpour, A. R.}, title = {Effects of Far- and Near-Field Multiple Earthquakes on the RC SDOF Fragility Curves Using Different First Shock Scaling Methods}, journal = {International Journal of Engineering}, volume = {31}, number = {9}, pages = {1505-1513}, year = {2018}, publisher = {Materials and Energy Research Center}, issn = {1025-2495}, eissn = {1735-9244}, doi = {}, abstract = {Typically, to study the effects of consecutive earthquakes, it is necessary to consider definite intensity levels of the first shock. Methods commonly used to define intensity involve scaling the first shock to a specified maximum interstorey drift. In this study the structure’s predefined elastic spectral acceleration caused by the first shock is also considered for scaling. This study aims to investigate the effects of consecutive far-field (FF) and near-field (NF) ground motions on the exceedance probability of different performance levels of a reinforced concrete single degree of freedom system considering the aforementioned first shock scaling methods. Eight groups of simulations are defined with each considering a combination of FF and NF ground motions. By using elastic spectral acceleration as the scaling method, it is found that the exceedance probability of the second shock performance levels, especially in pulse-like records, greatly depends on the order of far/near field ground motions and the level of damage caused by the first shock. It could be inferred that although first shock scaling method to maximum drift ratio is the commonly used method, the effects of record type multiple earthquakes are more revealed using elastic spectral acceleration as the first shock scaling criteria.}, keywords = {First shock intensity Scaling,Consecutive Earthquakes,Fragility curves,FAR,and Near,Field Ground Motions,Pulse Effects}, url = {https://www.ije.ir/article_73286.html}, eprint = {https://www.ije.ir/article_73286_ce189c860b63540670713adbf4de0471.pdf} } @article { author = {Mosa, A. M. and Jawad, I. T. and Salem, L. A.}, title = {Modification of the Properties of Warm Mix Asphalt Using Recycled Plastic Bottles}, journal = {International Journal of Engineering}, volume = {31}, number = {9}, pages = {1514-1520}, year = {2018}, publisher = {Materials and Energy Research Center}, issn = {1025-2495}, eissn = {1735-9244}, doi = {}, abstract = {Construction of flexible pavements with hot mix asphalt (HMA) mixtures consumes huge energy which impacts the resources and the environment of the world. Warm Mix Asphalt (WMA) is an effective alternative as they produced with lower mixing and compaction temperature than those used in HMA production. This technology decreases energy consumption, saves money, and reducing the environmental pollution. This technology, if combined with the use of waste materials to improve the properties of WMA, can generate a revolution in sustainable construction. Polyethylene Therephthalate (PET) wastes accumulated over the world increasingly. However, and to the best knowledge of the author, no such research adopts using PET wastes in combination with WMA properties improvement. Therefore, this study covers usage of PET waste bottles to modify the properties of WMA. The study adopted usage of ground PET waste bottles with maximum particle size of 2.36 mm with different contents (0.1%, 0.3%, 0.5%, 0.7%, 0.9%, and 1.1% by the weight of aggregate) to replace an equivalent portion of fine aggregate. The study involved a number of laboratory tests to investigate the effects of different PET content on the properties of WMA. The testing program included Marshall tests and rutting susceptibility tests. The results exhibited significant improvement in engineering properties of the mixtures modified with optimum PET content (which was found to be 0.5%) in terms of increase in stability and stiffness and decrease in rutting susceptibility without adverse effects on the other desirable properties of the mixture.}, keywords = {PET Waste,Marshall Properties,Rutting Susceptibility,WMA}, url = {https://www.ije.ir/article_73287.html}, eprint = {https://www.ije.ir/article_73287_45ba382848dde5441e4dc2b6b30a18f8.pdf} } @article { author = {Moazenzadeh, D and Hamidi, H.}, title = {Analysis and Development of Technology Acceptance Model in Mobile Bank Field}, journal = {International Journal of Engineering}, volume = {31}, number = {9}, pages = {1521-1528}, year = {2018}, publisher = {Materials and Energy Research Center}, issn = {1025-2495}, eissn = {1735-9244}, doi = {}, abstract = {Internet-based banking (Internet bank) has limitations such as access to the Internet Network and PC (Personal Computer) in addition to providing bank services at any time and easily to customers. The provision of mobile phone services with the title of Mobile Bank was introduced to eliminate these restrictions and limitations. Due to the importance of technology adoption by users, in this research, the technology acceptance model has been developed by taking into account the variables of the original model, by adding new variables such as risk perception, cost perception, trust, resistance, compatibility while examining the proposed models to examine these factors. This research has analyzed the statistical population using the questionnaire and has determined the following results. Individual's age has not much effect on the technology adoption according to results, and also individuals do not have much resistance to adopt the technology in this period, which will cause to adopt new technologies more and more. Individuals are also willing to pay for the use of technology and benefiting from its advantages, and cost has not affected the attitude of individuals and is not an impediment and barrier to technology adoption, and ultimately, individuals have adopted the risk of the use of technology, and this issue does not damage their trust in new technology.}, keywords = {Adoption of Mobile Bank,Mobile Bank,Development of Technology Acceptance Model,banking,Fuzzy TOPSIS}, url = {https://www.ije.ir/article_73288.html}, eprint = {https://www.ije.ir/article_73288_0c3117adf26951898de26c018856dc77.pdf} } @article { author = {Mavaddati, S.}, title = {Voice-based Age and Gender Recognition using Training Generative Sparse Model}, journal = {International Journal of Engineering}, volume = {31}, number = {9}, pages = {1529-1535}, year = {2018}, publisher = {Materials and Energy Research Center}, issn = {1025-2495}, eissn = {1735-9244}, doi = {}, abstract = {Abstract: Gender recognition and age detection are important problems in telephone speech processing to investigate the identity of an individual using voice characteristics. In this paper a new gender and age recognition system is introduced based on generative incoherent models learned using sparse non-negative matrix factorization and atom correction post-processing method. Similar to general signal classification scheme, our proposed algorithm includes train step to provide related atoms to each signal class and test phase to assess classification performance. Since the classification accuracy depends highly on the selected features, we employ Mel-frequency cepstral coefficients to train basis for better representation of speech structure. These bases are learned over data of male and female speakers using non-negative matrix factorization with sparsity constraint. Then, atom correction is carried out using an energy-based algorithm to decrease coherence between different categories of trained dictionaries. In sparse representation of each data class, atoms related to other sets with the highest energy are replaced with the lowest energy bases if reconstruction error does not exceed from a specified limit. The experimental results show that the proposed algorithm performs better than the earlier methods in this context especially in the presence of background noise.}, keywords = {Gender recognition,Sparse Non,negative matrix factorization,Incoherence,Mel,frequency cepstral coefficient,Voice processing}, url = {https://www.ije.ir/article_73289.html}, eprint = {https://www.ije.ir/article_73289_c2e5f510617f3ef6a6a325f1582f0843.pdf} } @article { author = {Masomi Kazraji, S. and Feyzi, M. R. and Sharifin, M. B. B. and Tohidi, S.}, title = {Sensorless Model Predictive Force Control with a Novel Weight Coefficients for 3-Phase 4-Switch Inverter Fed Linear Induction Motor Drives}, journal = {International Journal of Engineering}, volume = {31}, number = {9}, pages = {1536-1545}, year = {2018}, publisher = {Materials and Energy Research Center}, issn = {1025-2495}, eissn = {1735-9244}, doi = {}, abstract = {The sensorless model predictive force control (SMPFC) is a strong method for controlling the drives of three-phase 4(6)-switch inverter linear induction motors. This kind of inverter can be employed for fault tolerant control in order to solve the problem of open/short circuit in 6-switch inverters (B6). This paper proposed a method for the SMPFC of a linear induction motor (LIM) with a 4-switch inverter fed along with DC-link voltage offset suppression. Numerical simulations have been performed on several different LIMs in MATLAB software for determine the weight coefficients of the stator flux and the reduced of the capacitor voltage offset. Then, a relationship has been extracted for determining the weight coefficients of the stator flux and DC-link voltage in the cost function of the SMPFC. Using weight coefficients in the cost function, the B4 inverter voltage vectors under the DC-link capacitor voltage swing were obtained for the exact prediction. The balance among the currents was improved by determining the appropriate value for the weight coefficient of the reduced of the capacitor voltage offset. Simulation results were provided for the validation of the suggested control method.}, keywords = {Linear Induction Motor (LIM),Sensorless Model Predictive Force Control (SMPFC),4,switch inverter,Weight Coefficient}, url = {https://www.ije.ir/article_73290.html}, eprint = {https://www.ije.ir/article_73290_8b80ae0609abbf0d9239370b90546722.pdf} } @article { author = {Nath, D. and Pradhan, S. N.}, title = {Low Dropout Based Noise Minimization of Active Mode Power Gated Circuit}, journal = {International Journal of Engineering}, volume = {31}, number = {9}, pages = {1546-1552}, year = {2018}, publisher = {Materials and Energy Research Center}, issn = {1025-2495}, eissn = {1735-9244}, doi = {}, abstract = {Power gating technique reduces leakage power in the circuit. However, power gating leads to large voltage fluctuation on the power rail during power gating mode to active mode due to the package inductance in the Printed Circuit Board. This voltage fluctuation may cause unwanted transitions in neighboring circuits. In this work, a power gating architecture is developed for minimizing power in active mode and noise is analyzed. The effect of different noise minimization approaches for reducing power supply noise is evaluated in power gating architecture. A new concept of noise minimization technique using Low Dropout Voltage regulator is proposed in this paper. The amount of charge in the internal nodes of the power gating circuit passes through the sleep transistors during the wake-up transition is controlled by the proposed noise minimization techniques. The Low Dropout Voltage Regulator is designed newly in such a way that can be used to reduce bounce noise by minimizing voltage fluctuation on the power rail of power gating circuit. Architectures have been developed in Synopsys Custom Designer tool at iPDK 90nm technology. Percentage saving of noise on the power supply is reduced up to 99%.}, keywords = {architecture powergating data,retention leakage noise low,dropout voltage}, url = {https://www.ije.ir/article_73291.html}, eprint = {https://www.ije.ir/article_73291_2c7659bbf892d42f6d1f8047a494e26f.pdf} } @article { author = {Mousavi, S. S. and Ghasemi, J. and Gholami, M.}, title = {A High Gain and Forward Body Biastwo-stage Ultra-wideband Low Noise Amplifier with Inductive Feedback in 180 nm CMOS Process}, journal = {International Journal of Engineering}, volume = {31}, number = {9}, pages = {1553-1558}, year = {2018}, publisher = {Materials and Energy Research Center}, issn = {1025-2495}, eissn = {1735-9244}, doi = {}, abstract = {This paper presents a two-stage low-noise ultra-wideband amplifier to obtain high and smooth gain in 180nm CMOS Technology. The proposed structure has two common source stages with inductive feedback. First stage is designed about 3GHz frequency and second stage is designed about 8GHz. In simulation, symmetric inductors of TSMC 0.18um CMOS technology in ADS software is used.Simulations results show high and relatively smooth S21 equal to 18.674±1.38dB, noise figure of less than 3.7dB, power consumption of 14.6mW with 1.2v supply voltage and suitable matching at the input (S11}, keywords = {Low Noise Amplifier,UWB,Inductive feedback}, url = {https://www.ije.ir/article_73292.html}, eprint = {https://www.ije.ir/article_73292_261f88c34ca9fba5812b677964672a11.pdf} } @article { author = {Pourasad, Y.}, title = {Optimal Control of the Vehicle Path Following by Using Image Processing Approach}, journal = {International Journal of Engineering}, volume = {31}, number = {9}, pages = {1559-1567}, year = {2018}, publisher = {Materials and Energy Research Center}, issn = {1025-2495}, eissn = {1735-9244}, doi = {}, abstract = {Nowadays, the importance of the vehicles and its dramatic effects on human life is no secret. The use of trailers with multiple axels for transporting bulky and heavy equipment is essential. Increase in trailers axles which results increment of wheels, needs considerations in order to increase in transporting speed, maneuverability, safety, better control and path following accurately.  Therefore, in this paper dynamic modeling and control of a 5 axial trailer was studied. As well as to increase maneuverability and speed up, steering 3 axles was considered. Also, by using image processing trailer path following in desired path with the highest accuracy was achieved. In this study, first a 14 DoF model for a 5 axial trailer with 3 steering axles was considered and its characteristics were described. Then, dynamic equations including kinematic and kinetic of trailer was obtained. Then, with checking trailers behavior a linear quadratic optimal control algorithm was designed. To evaluate the performance of the control algorithm, control problem simulation for 3 maneuver; single lane change, double lane change and overtaking; was done. The results confirmed the performance of designed control algorithm and image processing accuracy in trailer path following.}, keywords = {Trailer,image processing,Path Following,Optimal control}, url = {https://www.ije.ir/article_73293.html}, eprint = {https://www.ije.ir/article_73293_4ada96e0fed758b738a665732dd2c011.pdf} } @article { author = {Roostaei, A. and Nakhai Kamal Abadi, I.}, title = {Considering Production Planning in the Multi-period Inventory Routing Problem with Transshipment between Retailers}, journal = {International Journal of Engineering}, volume = {31}, number = {9}, pages = {1568-1574}, year = {2018}, publisher = {Materials and Energy Research Center}, issn = {1025-2495}, eissn = {1735-9244}, doi = {}, abstract = {Generally, the inventory routing problem occurs in a supply chain where customers consider the supplier responsible for inventory replenishment. In this situation, the supplier finds the answer to questions regarding the time and quantity of delivery to the customer as well as the sequence of customers in the routes. Considering the effect of production decisions on answering these questions, the present paper examines the integrated decision making on production, routing and inventory in a two-echelon supply chain composed of a manufacturer and multiple retailers. Transshipment, as a policy in supply chain logistic which increase integration and decrease inventory cost, is also allowed between retailers. The mathematical formulation for the problem is developed and an adaptive large neighborhood search heuristic is proposed to solve this complicated problem. The results of numerical experiments show that the solutions yielded by the heuristic method have high efficiency.}, keywords = {Inventory routing,Production Planning,Transshipment between retailers,Adaptive large neighborhood search}, url = {https://www.ije.ir/article_73294.html}, eprint = {https://www.ije.ir/article_73294_56d823c2a4725045279477cd326ca693.pdf} } @article { author = {Shamekhi Amiri, A. and Ali Torabi, S. and Ghodsi, R.}, title = {A possibilistic bi-objective model for a competitive supply chain network design under variable coverage}, journal = {International Journal of Engineering}, volume = {31}, number = {9}, pages = {1575-1584}, year = {2018}, publisher = {Materials and Energy Research Center}, issn = {1025-2495}, eissn = {1735-9244}, doi = {}, abstract = {In this paper, the strategic planning of a supply chain under a static chain-to-chain competition on the plane is addressed. It is assumed that each retailer has a coverage area called the radius of influence. The demand of each demand zone is divided equally between the retailers which can cover that market. However, the demand of distant customers who are not in the retailers’ radius of influence, will be lost. This competition is modelled for a real case application of a super market chain. It is assumed that the chain’s owner wants to expand retail outlets to improve its market share. Since this expansion could affect the current customers of existing retailers, the owner wants to avoid attacking the market share of its current retailers. A bi-objective fuzzy mixed integer nonlinear model is proposed. For solving the model, it is first reformulated to a mixed integer linear program and then an interactive approach is devised to handle the fuzzy bi-objective model. Four expansion strategies are analysed from which useful managerial insights are drawn.}, keywords = {Facility location on the plane,Chain,to,chain competition,Radius of influence,Cannibalization effect,capacity planning,multi,objective possibilistic programming}, url = {https://www.ije.ir/article_73295.html}, eprint = {https://www.ije.ir/article_73295_b2d078eb39a9e2553712432252d24257.pdf} } @article { author = {Tadi Beni, Z. and Hosseini Ravandi, S. A. and Tadi Beni, Y.}, title = {Investigation of the Size Effect on the Nano-beam Type Piezoelectric Low Power Energy Harvesting}, journal = {International Journal of Engineering}, volume = {31}, number = {9}, pages = {1585-1592}, year = {2018}, publisher = {Materials and Energy Research Center}, issn = {1025-2495}, eissn = {1735-9244}, doi = {}, abstract = {In this paper, size dependent beam type peizoelectric energy hardvester is investigated. For this goal, first nonlinear formulation of isotropic piezoelectric Euler-Bernoulli nano-beam is developed based on the size-dependent piezoelectricity theory then special beam type piezoelectric energy hardvester is probed for different parameters. Basic nonlinear equations of piezoelectric nano-beam are derived using principle of minimum of potential energy and variational method. To evaluate the formulation derived, static deformation and free vibration of the clamped-clamped piezoelectric nano-beam is investigated in the special case. The results of the formulation derived are investigated under different parameters, and particularly, the ability and performance of the beam type piezoelectric low power energy harvesting was evaluated in nanoscale.}, keywords = {Piezoelectric,size effect,Euler,Bernoulli nano,Beam,Energy harvesting}, url = {https://www.ije.ir/article_73296.html}, eprint = {https://www.ije.ir/article_73296_e793807d1630ae5e49a7303327e3f85c.pdf} } @article { author = {Abbasi, S. and Zeinali, M. and Nejadabbasi, P.}, title = {Autonomous Underwater Vehicle Hull Geometry Optimization Using a Multi-objective Algorithm Approach}, journal = {International Journal of Engineering}, volume = {31}, number = {9}, pages = {1593-1601}, year = {2018}, publisher = {Materials and Energy Research Center}, issn = {1025-2495}, eissn = {1735-9244}, doi = {}, abstract = {Abstarct In this paper, a new approach to optimize an Autonomous Underwater Vehicle (AUV) hull geometry is presented. Using this methode, the nose and tail of an underwater vehicle are designed, such that their length constraints due to the arrangement of different components in the AUV body are properly addressed. In the current study, an optimal design for the body profile of a torpedo-shaped AUV is conducted, and a multi-objective optimization scheme based on the optimization algorithm NSGA-II (Non-dominated Sorting Genetic Algorithm-II, as an evolutionary algorithm) is employed. In addition, predefined geometrical constraints are considered so that equipment with the specific dimensions can be placed inside the AUV space without any effect on the AUV volume and the wetted surface. By optimizing the parameters of the newly presented profile, in addition to maximizing the volume and minimizing the wetted surface area, more diversed shapes can be achieved than with the ‘Myring’ profile. A CFD analysis of the final optimal design indicates that with the help of the proposed profile, the hydrodynamic parameters for the AUV hull are improved effectively.}, keywords = {Autonomous underwater vehicles,Hull shape design,multi,objective optimization}, url = {https://www.ije.ir/article_73297.html}, eprint = {https://www.ije.ir/article_73297_fa6cce3af96e86b7aec6dfcabacbfdd7.pdf} } @article { author = {Tabatabaei, S. M. R and Alasvand Zarasvand, K.}, title = {Investigating the Effects of Cold Bulge Forming Speed on Thickness Variation and Mechanical Properties of Aluminum Alloys: Experimental and Numerical}, journal = {International Journal of Engineering}, volume = {31}, number = {9}, pages = {1602-1608}, year = {2018}, publisher = {Materials and Energy Research Center}, issn = {1025-2495}, eissn = {1735-9244}, doi = {}, abstract = {In this work, cold bulge forming of an Aluminium-Magnesium (Al-Mg) sheet with a solid bulging medium is performed experimentally and numerically.  Mechanical properties and thickness variations of Al-Mg sheet are evaluated before and after the forming process.  The results indicated that the Al-Mg sheet has taken the desired shape without necking using the cold bulge forming process.  Also, the experimental results show significant improvements in mechanical properties of Al-Mg sheet after bulge forming.  It is proved that the maximum thickness reduction of Al-Mg blank is less than 6% after cold bulge forming.  Numerical simulations of cold bulge forming of Al-Mg sheet are conducted using Abaqus finite element software.  For this purpose, many numerical models are created and analysed to investigate the effects of bulge forming speed on the blank thickness variation for different Aluminium alloys.  In these simulations, four different speed of 1, 5, 15 and 25mm/min are used as forming speeds.  Numerical results of bulge forming of Al-Mg sheet are compared with experimental measurements and good correlation is observed between the results.  Moreover, obtained results from numerical simulations for different Aluminium alloys show that the thickness variations of formed Al-Mg sheet are more uniform by reducing the forming speed.}, keywords = {Cold bulge forming,Al,Mg sheet,Thickness variations,Numerical,experimental}, url = {https://www.ije.ir/article_73298.html}, eprint = {https://www.ije.ir/article_73298_d3218ee5617c83acbdf1425fddecfb99.pdf} }