Iran University Of Science And Technology Research Articles

Investigating pre-service EFL teachers’ attitudes and challenges of online teaching

Since teachers are the most responsible ones for integrating technology into their online teaching practices, understanding their attitudes and beliefs is of great importance. This study thus investigated pre-service English as a Foreign Language (EFL) teachers’ attitudes and perceived challenges of teaching online language courses. To this end, a questionnaire with three categories on teachers’ values and attitudes, beliefs, and communication self-efficacy and one on perceived online teaching challenges with five categories of attitudinal, pedagogical, interactional, supportive, and technical were administered to 100 MA students of Teaching English as a Foreign Language (TEFL) at Iran University of Science and Technology (IUST). Five open-ended questions were also administered to gain more insight into their attitudes and perceived challenges of online teaching. The results indicated that pre-service teachers were interested in online teaching and believed that online teaching could help learners develop their English language knowledge, and that the advances in online information technologies could provide great opportunities for language teaching and learning. The results also revealed that categories on the attitude scale were ranked as communication self-efficacy, teachers’ values and attitudes, and their beliefs. Considering perceived challenges of online teaching, Internet connection, lack of teacher professional development courses for effective online teaching, and lack of previous online learning experiences were found to be the most frequent challenges. The dimensions of challenges were hierarchically ranked as technical, pedagogical, interactional, supportive, and attitudinal. The findings could shed light into designing and developing professional development courses for student teachers who are willing to teach online language courses.

Integrating inquiry-based learning and computer supported collaborative learning into flipped classroom: effects on academic writing performance and perceptions of students of railway engineering

The objective of this study was twofold: (a) to determine the extent to which three types of instruction could improve writing performance of railway engineering students and (b) to explore students’ perceptions of flipped classroom, Edmodo, and Google Docs for improving their academic writing performance. The participants were 61 undergraduate students of railway engineering at Iran University of Science and Technology (IUST), who were divided into integrated flipped, conventional flipped, and traditional non-flipped groups. For the integrated flipped group, the inquiry-based learning was conducted in terms of five phases of orientation, conceptualization, investigation, data interpretation, and conclusion. They also used Edmodo and Google Docs as the two collaborative platforms for promoting writing skills. The conventional group only watched the instructional videos before the class, while for the traditional group neither the instructional videos nor the technological tools were used for improving their writing skills. The results of ANOVA revealed significant differences among the three groups in that learners in the integrated flipped group significantly outperformed those in the other groups, particularly in terms of the components of grammar and fluency. In addition, this approach made the learners more engaged, motivated, satisfied, and less anxious. The results also showed learners’ positive attitudes toward the pedagogical values of Edmodo and Google Docs.

Investigating pre-service EFL teachers’ and teacher educators’ experience and attitudes towards online interaction tools

This study investigated pre-service English language teachers’ and their instructors’ experience with using online interaction tools, their views of the effectiveness of interaction tools in language development, their attitudes to implementing the tools, and the challenges they face in online interaction. The participants were 100 MA students of TEFL and 7 teacher educators at Iran University of Science and Technology (IUST). The data collection instruments included four questionnaires on experience, knowledge, attitudes, and challenges of using online interaction tools in English language classes. A semi-structured interview was also conducted to examine teacher educators’ views of online interaction. The results revealed that pre-service teachers were not aware of all online interaction tools and their effectiveness in language development; they had a positive frame of mind regarding implementing interaction tools in language classes; and their most frequent challenges included lack of adequate technical infrastructure, knowledge, and collaboration. The results also showed that teacher educators held the view that interaction tools can foster interaction according to the nature and content of a course and that they are effective for online classes, traditional classes, and outside classroom activities to enhance language learning. Some barriers, such as technical issues, inadequate pedagogical and technological knowledge, learners’ anxiety, and limited online participation were also emphasized. To construct a successful online learning community, teacher educators are recommended to enhance pre-service teachers’ awareness of online interaction tools and their implementation in English language classes.

Pre-service EFL teachers’ conceptions and strategy use in managing online classes

This study investigated the conceptions and strategy use of 104 pre-service EFL teachers while they were managing online English language classes at Iran University of Science and Technology (IUST). Data were collected through the use of a questionnaire on classroom management strategies and 16 questions on challenging online situations in terms of managing online teaching, content, interaction, time, and behavior. Analysis of the data revealed that time management, course organization, positive reinforcement, and building a positive atmosphere were considered the most important strategies for online classroom management. The results also showed that the student teachers mostly suggested the use of collaborative tasks and learner-centered strategies in response to the challenges of online classes. The findings suggest that teachers have a key role in building rapport as well as creating a positive, safe, and friendly atmosphere within online classes. These findings have implications for language teacher education programs to develop pre-service teachers’ strategies for managing online English language classes.

To interact or not to interact: Why students print interactive Instructional Multimedia? Problem of Reading or Reviewing?

Interactive digital Learning objects is a core of eLearning systems. Although multimedia learning theory support learning via multimedia. Surprisingly, observations imply that a significant number of students change interactive learning objects to static printed text. The aim of this study is to find what factor(s) influence changing interactive learning objects to print. To achieve the goal, a survey conducted in Iran University of Science and Technology (IUST) E-Learning Centre. Qualitative content analysis revealed “reviewing problem” as a main theme. To find key factors related to the problem, 169 online learners voluntary answered an online questionnaire. To analyse quantitative data Educational Data Mining (EDM) were used. Finding from the decision tree and rule induction that conducted by WEKA, revealed the “problem of reviewing” is the most important factor that interpret student behaviour in printing interactive digital learning objects.

A destructive phase (shift)

A metamaterial approach to wideband radar cross section reduction that is thin, low-cost and doesn't dictate object shaping is presented in work from Iran. The approach uses principles potentially applicable to infrared and visible light as well as radar. The wideband RCS reducing surface is produced on a commercial high-frequency circuit substrate using conventional printed circuit manufacturing techniques Reducing an object's detectability to radar systems is now a well established priority for military applications, most famously in aircraft applications. ‘Stealth’ aircraft that were once well kept secrets are now a familiar concept to the general public and even fly in air shows. The radar cross section (RCS) of an object is essentially a measure of how detectable an object is to radar systems and so reducing an object's RCS is the basic goal of radar focused ‘stealth’ technologies. There are three main approaches to reducing RCS; radar absorbing material (RAM), object shaping and reflected wave cancelling by object coating. RAM materials, as the name suggests, are designed to reduce radar reflections back to the detector by absorbing the electromagnetic energy transmitted by the radar system, converting it into heat. However, they can be bulky and high maintenance. Object shaping works by shaping the surface of the object to minimise reflections of the radar waves back to the radar system, instead reflecting them in other directions. The obvious disadvantage to this approach is that it dictates the shape of the object, which can compromise the performance of the object for its primary purpose. For example, above all an aircraft must be shaped to enable it to fly, an aircraft that is very hard to detect but cannot take off is of no use to anyone. The work reported in this issue, by researchers at Iran University of Science and Technology (IUST) uses the third approach, in which a surface coating reflects the radar waves in such a way as to reduce the amount of radar energy that returns to the detector. This approach is low profile, low bulk and doesn't dictate the shape of the object. In the IUST team's work it can also be cheaply and simply manufactured using printed circuit board manufacturing techniques. Their proposed structure consist of a chessboard arrangement of two different artificial magnetic conductor (AMC) unit cell patterns, each of which reflects the radar waves differently. The key difference in the reflections is a 180° phase shift, which causes the reflections from the two different AMC cell types to interfere destructively and so significantly reduces the useful energy returned to the radar system's detector. “Since radar systems usually send out a short pulse signal in the time domain, wide bandwidth of the RCS reducer is necessary. The proposed AMC structure achieves a RCS reduction over a very wide bandwidth, about 85%,” said Dr Seid Hasan Sedighy, one of the IUST researchers on this project. The wide bandwidth achieved is possible because the critical 180° phase difference in the reflections is produced by the AMC unit cells over a wide frequency range, from 9.4 GHz to 23.28 GHz, providing 10 dB RCS reduction in that range. The peak RCS reduction is in excess of 40 dB, at 15 GHz. Printed circuit manufacturing techniques were used to create the AMC patterns on a commercial high-frequency circuit substrate, providing a low-cost manufacturing method. As flexible circuit board technologies are now available and continue to develop, this AMC-based, effective and relatively cheap approach to RCS reductions could be applied to arbitrary shapes. AMCs are metamaterial structures that behave as perfect magnetic conductors in a limited range of frequencies. The two unit cell AMC patterns used in this work are an arrangement of ‘E’ shapes and saltire arrows. The patterns were optimised to achieve the desired 180° phase difference in their reflections by simulation before being confirmed by experiment. The RCS reducer consists of a chessboard pattern of AMC patches using two different AMC unit cell designs, which produce reflections 180° out of phase with each other. The resulting destructive interference provides the intended RCS reduction The principles of AMCs and using destructive interference to reduce reflected energy are of course applicable to other frequencies of the EM spectrum, not just the band used for radar. This means that similar effects could be achievable in very different frequencies if the structures can be manufactured. Dr Sedighy expects this to lead to developments closer to photonic frequencies “It seems that this design approach will develop in the other frequency bands such as visible and infrared frequencies, which have many civil and military applications.”

A Novel Application of Sensor Networks in Biomedical Engineering

Born on other applications, wireless sensor networks (WSNs) grew on the promise of biomedical engineering applications. In this research we suggest system architecture for smart healthcare, based on a novel WSN. Our system particularly targets assisted-living residents and others who may help from continuous remote health monitoring. We present the objectives, advantages, and status of the design. An experimental livelihood space has been constructed at the Department of Biomedical Engineering (DBE) at Iran University of Science and Technology (IUST) for assessment of our system. A ten days monitoring and experimental results suggest a physically powerful potential for WSNs to open new research area in biomedical engineering, i.e. for low-cost, ad hoc use of multimodal sensors for a better quality of medical care.

Compensating the flexibility uncertainties of a cable suspended robot using SMC approach

SUMMARYA sliding mode controller is designed to compensate for the flexibility uncertainties of a cable robot and improve its tracking performance. Of the most significant sources of these uncertainties are the elasticity of the cables and the flexibility of the joints. A favorable approach to improve the accuracy of the system is first to model the cable and joint flexibilities and then convert the model uncertainties into parametric uncertainties. Parametric uncertainties are the product of imprecise flexibility coefficients and are finally neutralized by a sliding mode controller. The flexibility in cables is modeled by considering the longitudinal vibration of the time-varying length cables. A simulation study is carried out to confirm the presented model and the positive effect of the designed controller. Then the impact of these uncertainties on the dynamic load carrying capacity (DLCC) of the robot is examined and compared for different cases. Finally, experimental tests are conducted on the IUST (Iran University of Science and Technology) cable-suspended robot to validate the presented theories and simulation results.

L-Sensors in Aerospace

Sabzpoushan SH 1 and Sabzpoushan SA 2 1Biomedical Engineering Department, School of Electrical Engineering, Iran University of Science and Technology (IUST), Iran 2Department of Aerospace Engineering, Sharif University of Technology, Tehran, Iran *Corresponding author: Sabzpoushan SH, Biomedical Engineering Department, School of Electrical Engineering, Iran University of Science and Technology (IUST), Iran, Tel: +98-21-73225729,73225600; E-mail: sabzposh@iust.ac.ir

Centrifugal compressor performance assessment under different impeller tip clearance sizes from far to near stall conditions

Impeller tip clearance is a key parameter in design process of a centrifugal compressor which has influential effects on its aerodynamic and thermodynamic performances. Interaction of tip leakage flow with the main stream could be the major source for occurrence of stall phenomenon. In the present investigation, two impeller tip clearances of small and large sizes are investigated under different flow coefficients assigned to “design”, “low flow” and “high flow” conditions. Flow field is precisely simulated utilizing solution of the Reynolds-Averaged Navier-Stokes equations. Influence of the impeller stall on the volute flow field is studied. Structure of vortical flows within the impeller passages and volute are demonstrated in details. Numerical results showed that the flow within the volute becomes stall-prone while the flow within the impeller stalls. In contrast to the high flow case, the low flow condition was more prone for the stall occurrence. Performance tests were also conducted on Iran University of Science and Technology (IUST) centrifugal compressor test rig for validation of the numerical results.

Unusual Antibacterial Property of Mesoporous Titania Films: Drastic Improvement by Controlling Surface Area and Crystallinity

One of the most urgent requirements of human life in the 21 century is development of new antibacterial materials and sterilization technologies that can improve human health. Until now, the most commonly used antibacterial agents are based on chlorine, chlorine dioxide, and organic biocide compounds. These agents are extremely toxic for humans and their residues are also not environmentally friendly. Therefore, it is very important to develop antibacterial biocompatible materials. Titanium dioxide (titania, TiO2) materials in the anatase form have attracted great interest as a new antibacterial material. Titania can work well under ultraviolet (UV) light owing to its photo-semiconductor properties. Currently, this property has been widely utilized for various applications such as water treatment, air and environmental purification, hazardous waste remediation, and deactivation of bacteria. Commercial products with titania (e.g., self-cleaning glasses and anti-fogging coatings) are well known all over the world. To date, various titania-based nanostructures including nanorods and nanoparticles have been reported. To further enhance the photocatalytic performance, many efforts have been made for doping various metal/semiconductor elements into titania materials. In this system, the electrons accumulated on the metal and holes remained on the photocatalyst surface. Therefore, a significant reduction in the recombination rate is realized owing to better charge separation between the electrons and holes. Therefore, the titania-based composites with metal/semiconductor elements can enhance the overall photocatalytic efficiency and the damage of microorganisms of the cell. In this Communication, we focused on a further simple and low-cost synthetic method and synthesized mesoporous titania films by utilizing bottom-up nanotechnology with surfactant assembly. Mesoporous materials with extremely high surface area should be good candidates for the next generation of antibacterial materials. Compared with the traditional titania materials mentioned above, the high surface area originated from mesoporous networks can provide a higher amount of hydroxyl radicals (·OH) which can increase the photoactivity. In the past few years, special attention has been paid to the synthesis of mesoporous titania powders as effective photocatalysts including an antibacterial application. However, the mesoporous titania in the powder form has some disadvantages. The powders which are not fixed on substrates are washed out easily by external treatments and then the released particles themselves may pollute the environment. Also, nanosized powders generally cause serious problems to human health. Therefore, the mesoporous titania films reported here are more applicable [a] H. Oveisi, X. Jiang, Dr. Y. Nemoto, Prof. Dr. Y. Yamauchi World Premier International (WPI) Research Center for Materials Nanoarchitectonics (MANA) National Institute for Materials Science (NIMS) 1-1 Namiki, Tsukuba, Ibaraki, 305-0044 (Japan) Fax: (+81)29-860-4706 E-mail : Yamauchi.Yusuke@nims.go.jp [b] Dr. S. Rahighi, Prof. Dr. S. Wakatsuki Structural Biology Research Center High Energy Accelerator Research Organization (KEK) 1-1 Oho, Tsukuba, Ibaraki, 305-0801 (Japan) [c] H. Oveisi, Prof. Dr. A. Beitollahi Center of Excellence in Advanced Materials and Processing Department of Metallurgy and Materials Engineering Iran University of Science and Technology (IUST) Narmak, Tehran 16844 (Iran) [d] X. Jiang, Prof. Dr. Y. Yamauchi Faculty of Science and Engineering Waseda University 3-4-1 Okubo, Shinjuku, Tokyo 169-8555 (Japan) [e] Prof. Dr. Y. Yamauchi Precursory Research for Embryonic Science and Technology (PRESTO) Japan Science and Technology Agency (JST) 4-1-8 Honcho, Kawaguchi, Saitama 332-0012 (Japan). [] These authors contributed equally to this work. Supporting information for this article is available on the WWW under http://dx.doi.org/10.1002/asia.201000351.

Iran Science Officials In Plagiarism Flap

![Figure][1] Daneshjou. CREDIT: REUTERS Four scientific journals have retracted research articles by top Iranian government scientists, including the minister of science, after concluding that they include plagiarized material. The flap started late last month when Nature reported that much of a 2009 article in the journal Engineering with Computers was copied verbatim from a 2002 article by South Korean researchers in the Journal of Physics D: Applied Physics . Both articles describe experiments involving tungsten alloy rods ricocheting off steel plates. The first author on the 2009 paper is Iran's science minister, Kamran Daneshjou, who wrote it with his former Ph.D. student Majid Shahravi, an engineer at the Iran University of Science and Technology (IUST) in Tehran. Nature subsequently reported plagiarism in two more articles by the same pair. Iranian emigre scientists have expressed outrage and noted with irony that Daneshjou helped orchestrate the election—widely rejected as a fraud—of Iranian President Mahmoud Ahmadinejad. But some researchers in Iran are sticking up for Daneshjou and pointing the finger at his co-author. “After [Shahravi] has officially admitted his complete fault on this matter, he must be punished accordingly,” says engineer Seyyed Hasheminejad of IUST. In an interview with Iranian media, Shahravi denied any plagiarism, noting that articles by others had been cited in footnotes. Late last week, the plagiarism scandal had widened to include a 2006 paper co-authored by Iranian roads and transportation minister—and Ahmadinejad's former Ph.D. adviser—Hamid Behbahani. [1]: pending:yes