توجه: محتویات این صفحه به صورت خودکار پردازش شده و مقاله‌های نویسندگانی با تشابه اسمی، همگی در بخش یکسان نمایش داده می‌شوند.
۱Coupled Axial–Torsional Vibration of Thin–Walled Z–Section Beam
اطلاعات انتشار: هجدهمین کنفرانس سالانه مهندسی مکانیک، سال
تعداد صفحات: ۶
The coupled axial–torsional vibration of thin–walled Zsection beam induced by the boundary conditions is considered. The restrained axial displacement of the pin end at centroid of Z–section of a thin–walled beam causes the coupling of the axial and torsional vibration. The bending vibration is not dealt with in this paper, because it is uncoupled from axial and torsional vibration. The object of this paper is to investigate thecoupled axial and torsional vibration of thin–walled Zsection beam induced by the different boundary conditions. The correct governing differential equations for linear axial and torsional vibration of a uniform Zsection beam are derived using the d’Alembert and virtual work principles based on the Vlasov thin–walled theory. Numerical examples are studied to verify the accuracy of the proposed method and to consider the effect of boundary conditions and the value of warping function at centroid of the coupled axial and torsional natural frequency of Z–section beam. It is shown the lowest 10 natural frequency and shape modes in this section and a solving of problem using FEM for a case of boundary condition to verify the method.<\div>

۲Multi–objective Optimization based on a Multiple–crossover Genetic Algorithm
اطلاعات انتشار: بیستمین کنفرانس سالانه مهندسی مکانیک، سال
تعداد صفحات: ۵
In this paper, first a multiple–crossover genetic algorithm is presented. Its operators such as reproduction, crossover and mutation are introducedcompletely. Some multi–objective benchmark problems are selected to challenge the ability of the proposed method. Optimization is based on the non–dominated sorting idea. Simulation results are presented. The results are compared with true Pareto–optimal solutions to evaluate the performance of the proposed method<\div>

۳Constrained Optimization of an I–beam Using Game Theory and Modified Particle Swarm
نویسنده(ها): ، ،
اطلاعات انتشار: بیستمین کنفرانس سالانه مهندسی مکانیک، سال
تعداد صفحات: ۴
One of the most important applications of optimization is adjusting parameters of practical engineering problems in order to produce a more desirable outcome. This paper is aimed at promoting Particle Swarm Optimization (PSO) by three effective techniques: (1) assigning special inertia weight to each particle based on the position of particle within the swarm; (2) use of two operators for producing new positions to enhancediversity of solutions and (3) use of learning factors based on the random numbers. To evaluate the accuracy and convergence speed of the proposed method, some well–known PSO algorithms are used for comparison. The results demonstrate that the proposed algorithm is valid to improve PSO. Also, proposed method is used to design an optimal I–beam with two objectives and constraints. The game theory approach is employed to handle objectives. Ultimately, the feasibility and efficiency of the designed beam is assessed in results<\div>

۴STABILITY ANALYSIS OF AN UNDERCONSTRAIND CABLE ROBOT IN 3–DIMENSION SPACE
نویسنده(ها): ،
اطلاعات انتشار: کنفرانس ملی مهندسی مکانیک ایران، سال
تعداد صفحات: ۸
Stability Analysis of an underconstrained cable robot in the 3–dimension space for a path of an underconstrained cable robot is computed. But compute of stability for a cable robot can be very difficult. In order to compute this analysis define a measure for 2–dimension space, then we extending this measure to 3–dimension space. In order to the set of twists that the end–effector can undergo is camputed. With wrenches that force in end–effector we can be campute the twists of end–effector. In this measure we definition of slope for mixed–dimensional twists because is then derived using an energy–based approach to generalize measure. An example is worked out for a sample manipulator and the stability measure is used to define a measure of overall manipulator stability<\div>

۵Borohydride Synthesis of the PtFeCo\Gr Electrocatalysts for Oxygen Reduction Reaction in Proton Exchange Membrane Fuel Cells
اطلاعات انتشار: دومین کنفرانس بین المللی یافته های نوین پژوهشی در شیمی و مهندسی شیمی، سال
تعداد صفحات: ۵
Insufficient catalytic activity and durability are the most challenging issues in the commercialization of proton exchange membrane fuel cells. In an effort to address these barriers, PtFeCo\Gr electrocatalyst were prepared via the reduction of precursors in the presence of glycerol as stabilizer. The electrocatalytic performances of the synthesized PtFeCo\Gr alloy electrocatalysts were compared with that of PtFeCo\Gr electrocatalyst which prepared in the absence of glycerol. Physical property studies (XRD) and electrochemical analyses with catalyst layers immobilized on glassy carbon electrodes and electrochemical behavior of the synthesized electrocatalyst. Finally, a cell performance investigation, using the synthesized electrocatalyst was carried out in a single PEMFC setup.Among these electroctalysts, the PtFeCo\G–A catalyst exhibits the highest activity, a better behavior was obtained for the PtFeCo\G–A and the maximum power density produced from proton exchange membrane fuel cell with PtFeCo\G–A electrocatalyst which was prepared in the presence of glycerol as stabilizer was 9% higher than PtFeCo\G–B which was prepared in the absence of glycerol.<\div>

۶A novel SPEEK\SPVDF–co–HFP blend proton exchange membrane for direct methanol fuel cell applications
نویسنده(ها): ،
اطلاعات انتشار: دومین کنفرانس بین المللی یافته های نوین پژوهشی در شیمی و مهندسی شیمی، سال
تعداد صفحات: ۱۰
In this work, blend membranes based on sulfonated poly(ether ether ketone) (SPEEK) and sulfonated polyvinylidene fluoride–co–hexafluoropropylene (SPVDF–co–HFP) with 10 wt% concentration of polymer blend in solution were prepared by solution casting method. The PEEK and PVdF–co–HFP were sulfonated with direct sulfonation method to reach sulfonation degree of 68% and 31%, respectively. The different weight ratios of blend polymers were synthesized and weight ratio of 20 wt% SPVDF–co–HFP exhibited the best properties in terms of few essential membrane properties such as membrane swelling, water uptake, thermal and stability, methanol permeability, proton conductivity and DMFC performance.<\div>

۷Tehran Stock Exchange Daily Index Forecasting By Adaptive Network–based Fuzzy Inference System
اطلاعات انتشار: اولین کنفرانس بین المللی حماسه سیاسی (با رویکردی بر تحولات خاورمیانه) و حماسه اقتصادی (با رویکردی بر مدیریت و حسابداری)، سال
تعداد صفحات: ۷
To be successful in financial market treading, it’s necessary to predict the future movement of market correctly. Most of professional traders use technical analysis to forecast future market price. In this paper we present a new Adaptive Network–based Fuzzy Inference System (ANFIS) model to forecast financial time series especially Tehran Stock Market Daily Index. Like real traders this method uses statistical based indicators to forecasting market movements. There are many indicators and oscillators for market analysis, but in this paper we examine the efficiency of these indicators especially in Tehran Stock Market Index and select four top rated indicators as ANFIS inputs. The results shows that this model is very useful in stock market decision support field and have an acceptable accuracy.<\div>

۸Adaptive and Sliding Mode Control for Non– Linear Systems
اطلاعات انتشار: International Journal of Advanced Design and Manufacturing Technology، سال
تعداد صفحات: ۶
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