Développer l’expression écrite du français par les activités de pensée critiquey

Soodeh Eghtesad,Akram Inanloo Khajlo 고려대학교 응용문화연구소 2020 에피스테메 Vol.0 No.24

This study analyzes the impact of a practical teaching of critical thinking on the writing skills of French language learners in an institutional context in Iran. Learners were divided into two groups, an experimental group and a control group; Honey's (2005) Critical Thinking Questionnaire was administered to the participants and their scores were analyzed to ensure that there was no significant difference between the two groups regarding their critical thinking abilities at the beginning of the training. Learners completed five semesters of coursework with identical course objectives and activities. However, the experimental group also received critical thinking training through media analysis, debates, and problem-solving activities. The analysis of the data, which consisted of qualitative analysis of students’ writings in the middle and at the end of the training, indicates that the experimental group outperformed the control group in writing. These results imply that critical thinking activities had a positive impact on learners' writing skills since they allowed them to perform writing tasks by paying attention to the writing as a process, rather than only focusing on the final product. Soodeh Eghtesad・Akram Inanloo Khajlo 121 [RÉSUMÉ] Développer l’expression écrite du français par les activités de pensée critique Soodeh Eghtesad・Akram Inanloo Khajlo Cette étude tente d’analyser l'impact de l'enseignement de la pensée critique sur le développement des compétences d'écriture des apprenants du français langue étrangère en contexte insitutionnel en Iran. Les apprenants étaient divisés en deux groupes, un groupe expérimental et un groupe témoin et le questionnaire de pensée critique de Honey (2005) était administré aux participants des deux groupes afin d’assurer qu'il n'y avait pas de différence significative entre les deux groupes concernant leur capacité de pensée critique au début de la formation. Les apprenants ont suivi cinq semestres de formation dont les objectifs du cours et les activités étaient identiques, mais le groupe expérimental a également reçu une formation à la pensée critique à travers des activités d’analyse des médias, de résolution de problèmes, et de débats, tandis que le groupe témoin n’a suivi aucune formation à la pensée critique. L’analyse des données, qui consiste en analyse qualitative des écritures des apprenants des deux groupes au milieu et à la fin de la formation, montre que le groupe expérimental a surpassé le groupe témoin en matière de production écrite, ce qui indique que l’enseignement de la pensée critique avait un impact positif sur les compétences d’écriture des apprenants, puisqu’elle les a rendus capables d’écrire en faisant attention au processus d’écriture plutôt que focaliser uniquement sur le produit final.

Trajectory tracking and active vibration suppression of a smart Single-Link flexible arm using a composite control design

Mirzaee, E.,Eghtesad, M.,Fazelzadeh, S.A. Techno-Press 2011 Smart Structures and Systems, An International Jou Vol.7 No.2

This paper is concerned with the trajectory tracking and vibration suppression of a single-link flexible arm by using piezoelectric materials. The dynamics of a single flexible arm with PZT patches as sensor and actuator is derived using extended Hamilton's principle. Resulting equations show that the coupled beam dynamics including beam vibration and its rigid in-plane rotation takes place in two different time scales. By using singular perturbation theory, the system dynamics is divided into two subsystems. Then, a composite control scheme is elaborated that makes the orientation of the arm track a desired trajectory while suppressing its vibration. The proposed controller has two parts: one is a tracking controller designed for the slow (rigid) subsystem, and the other one is a stabilizing controller for the fast (flexible) subsystem. The outputs considered for the system are angular position of the hub and voltage of the sensor mounted on the structure. To avoid requiring further measurements of beam vibration and also angular velocity of the hub for the fast and slow control laws, respectively, two sliding mode observers for estimating the unknown states are also designed.

Optimized ANNs for predicting compressive strength of high-performance concrete

Hossein Moayedi,Amirali Eghtesad,Mohammad Khajehzadeh,Suraparb Keawsawasvong,Mohammed M. Al-Amidi,Bao Le Van 국제구조공학회 2022 Steel and Composite Structures, An International J Vol.44 No.6

Predicting the compressive strength of concrete (CSoC) is of high significance in civil engineering. The CSoC is a highly dependent and non-linear parameter that requires powerful models for its simulation. In this work, two novel optimization techniques, namely evaporation rate-based water cycle algorithm (ER-WCA) and equilibrium optimizer (EO) are employed for optimally finding the parameters of a multi-layer perceptron (MLP) neural processor. The efficiency of these techniques is examined by comparing the results of the ensembles to a conventionally trained MLP. It was observed that the ER-WCA and EO optimizers can enhance the training accuracy of the MLP by 11.18 and 3.12% (in terms of reducing the root mean square error), respectively. Also, the correlation of the testing results climbed from 78.80% to 82.59 and 80.71%. From there, it can be deduced that both ER-WCA-MLP and EO-MLP can be promising alternatives to the traditional approaches. Moreover, although the ER-WCA enjoys a larger accuracy, the EO was more efficient in terms of complexity, and consequently, time-effectiveness.

Trajectory tracking and active vibration suppression of a smart Single-Link flexible arm using a composite control design

E. Mirzaee,M. Eghtesad,S.A. Fazelzadeh 국제구조공학회 2011 Smart Structures and Systems, An International Jou Vol.7 No.2

This paper is concerned with the trajectory tracking and vibration suppression of a single-link flexible arm by using piezoelectric materials. The dynamics of a single flexible arm with PZT patches as sensor and actuator is derived using extended Hamilton’s principle. Resulting equations show that the coupled beam dynamics including beam vibration and its rigid in-plane rotation takes place in two different time scales. By using singular perturbation theory, the system dynamics is divided into two subsystems. Then, a composite control scheme is elaborated that makes the orientation of the arm track a desired trajectory while suppressing its vibration. The proposed controller has two parts: one is a tracking controller designed for the slow (rigid) subsystem, and the other one is a stabilizing controller for the fast (flexible) subsystem. The outputs considered for the system are angular position of the hub and voltage of the sensor mounted on the structure. To avoid requiring further measurements of beam vibration and also angular velocity of the hub for the fast and slow control laws, respectively, two sliding mode observers for estimating the unknown states are also designed.

Creeping flow of Herschel-Bulkley fluids in collapsible channels: A numerical study

Ali Amini,Amir Saman Eghtesad,Kayvan Sadeghy 한국유변학회 2016 Korea-Australia rheology journal Vol.28 No.4

In this paper, the steady flow of a viscoplastic fluid is modeled in a planar channel equipped with a deformable segment in the middle of an otherwise rigid plate. The fluid is assumed to obey the Herschel-Bulkley model which accounts for both the yield stress and the shear-thinning behavior of physiological fluids such as blood. To accommodate the large deformations of the flexible segment, it is assumed to obey the twoparameter Mooney-Rivlin hyperelastic model. The so-called fluid-structure interaction problem is then solved numerically, under creeping-flow conditions, using the finite element package, COMSOL. It is found that the yield stress leads to a larger wall deformation and a higher pressure drop as compared with Newtonian fluids. This behavior is predicted to intensify if the fluid is shear-thinning. That is, for a given yield stress, the pressure drop and the wall deformation both increase with an increase in the degree of the fluid's shear-thinning behavior.

Analysis of an electrically actuated fractional model of viscoelastic microbeams

Bahraini, Seyed Masoud Sotoodeh,Eghtesad, Mohammad,Farid, Mehrdad,Ghavanloo, Esmaeal Techno-Press 2014 Structural Engineering and Mechanics, An Int'l Jou Vol.52 No.5

The MEMS structures usually are made from silicon; consideration of the viscoelastic effect in microbeams duo to the phenomena of silicon creep is necessary. Application of the fractional model of microbeams made from viscoelastic materials is studied in this paper. Quasi-static and dynamical responses of an electrically actuated viscoelastic microbeam are investigated. For this purpose, a nonlinear finite element formulation of viscoelastic beams in combination with the fractional derivative constitutive equations is elucidated. The four-parameter fractional derivative model is used to describe the constitutive equations. The electric force acting on the microbeam is introduced and numerical methods for solving the nonlinear algebraic equation of quasi-static response and nonlinear equation of motion of dynamical response are described. The deflected configurations of a microbeam for different purely DC voltages and the tip displacement of the microbeam under a combined DC and AC voltages are presented. The validity of the present analysis is confirmed by comparing the results with those of the corresponding cases available in the literature.

Control of mixing process in a novel micro-mixer

Behzad Otrodi,Mohammad Eghtesad,Mojatba Mahzoon,Saeid movahed 제어로봇시스템학회 2012 제어로봇시스템학회 국제학술대회 논문집 Vol.2012 No.10

There are many different types of micro-mixers which have been designed to enhance mixing efficiency of fluid flow in micro-channels. The output of micro-channels integrated with micro-mixers in some cases may need to be in a certain range. In this article we design a new type of micro-mixer by utilizing conductive surfaces and walls with variable zeta potential. Interaction of the induced charged electro-kinetic (ICEK) phenomenon (due to existence of conductive surfaces) and producing diverse electro-osmotic boundary velocity (because of presence of walls with changeable zeta potential) together lead to increase mixing efficiency of the system significantly. Numerical simulation are performed to analyze the system and the results show that by using this micro-mixer with different zeta potential applied to walls, we can have a wide range of mixing efficiency between 30% and 85%. Moreover, we applied a fuzzy logic controller (FLC) to the system to manage the percentage of mixing efficiency within this range. This controller based on desired mixing efficiency; determine the amount of zeta potential on each wall and thus we can reach the amount of required mixing efficiency.

Large deflection of viscoelastic beams using fractional derivative model

Seyed Masoud Sotoodeh Bahraini,Mohammad Eghtesad,Mehrdad Farid,Esmaeal Ghavanloo 대한기계학회 2013 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.27 No.4

This paper deals with large deflection of viscoelastic beams using a fractional derivative model. For this purpose, a nonlinear finite element formulation of viscoelastic beams in conjunction with the fractional derivative constitutive equations has been developed. The four-parameter fractional derivative model has been used to describe the constitutive equations. The deflected configuration for a uniform beam with different boundary conditions and loads is presented. The effect of the order of fractional derivative on the large deflection of the cantilever viscoelastic beam, is investigated after 10, 100, and 1000 hours. The main contribution of this paper is finite element implementation for nonlinear analysis of viscoelastic fractional model using the storage of both strain and stress histories. The validity of the present analysis is confirmed by comparing the results with those found in the literature.

OPTIMIZATION AND DESIGN OF DISK-TYPE MR BRAKES

B. ASSADSANGABI,F. DANESHMAND,N. VAHDATI,M. EGHTESAD,Y. BAZARGAN-LARI4 한국자동차공학회 2011 International journal of automotive technology Vol.12 No.6

In this paper, first a new design for a disk-type magneto-rheological (MR) brake for automotive applications is proposed and then, a finite element analysis is performed to analyze the resulting magnetic field intensity distribution within the MR brake configuration. This finite element model of the brake is then utilized in a optimization process which incorporates Genetic Algorithm (GA) to obtain optimal design parameters. The optimization process goal is to increase the braking torque capacity of the brake while keeping the weight of the brake as low as possible. Although, the braking torque of the present design is larger compared to the previous designs, the braking toque capacity of the present design is still smaller than the required braking torque for automobiles.

Analysis of an electrically actuated fractional model of viscoelastic microbeams

Seyed Masoud Sotoodeh Bahraini,Mohammad Eghtesad,Mehrdad Farid,Esmaeal Ghavanloo 국제구조공학회 2014 Structural Engineering and Mechanics, An Int'l Jou Vol.52 No.5

The MEMS structures usually are made from silicon; consideration of the viscoelastic effect inmicrobeams duo to the phenomena of silicon creep is necessary. Application of the fractional model of microbeams made from viscoelastic materials is studied in this paper. Quasi-static and dynamical responses of an electrically actuated viscoelastic microbeam are investigated. For this purpose, a nonlinear finite element formulation of viscoelastic beams in combination with the fractional derivative constitutive equations is elucidated. The four-parameter fractional derivative model is used to describe the constitutive equations. The electric force acting on the microbeam is introduced and numerical methods for solving the nonlinear algebraic equation of quasi-static response and nonlinear equation of motion of dynamical response are described. The deflected configurations of a microbeam for different purely DC voltages and the tip displacement of the microbeam under a combined DC and AC voltages are presented. The validity of the present analysis is confirmed by comparing the results with those of the corresponding cases available in the literature.