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1.
We designed and used a series of activities （named activities to teaching electric field （ATEF）） based on the Physics by Inquiry （PBI） strategy to teaching the electric field concept with university students. We used a concentration factor tool to assess the effectiveness of those activities used during three weeks of instruction. Results indicate that students who had traditional teaching obtained a very tiny gain （less than 1%）; concentration factors indicate that most of their responses fall into a random area, which is not favorable. On the other hand, the experimental group using our activities had greater gains （〉 10%） than the control group. Concentration factors showed that after instruction, students＇ mental models changed toward a favorable pattern about comprehension of electric field concept and Coulomb＇s law. A hypothesis test of two samples indicated that there is a significant difference between both traditional teaching and ATEF based on PBI.  相似文献   

2.
Abstract The compliance of an integrated approach, principal component analysis （PCA）, coupled with Tagu chi＇s robust theory for simultaneous optimization of cor related multiple responses of wire electrical discharge machining （WEDM） process for machining SiCp rein forced ZC63 metal matrix composites （MMCs） is investi gated in this work. The WEDM is proven better for its efficiency to machine MMCs among others, while the particulate size and volume percentage of SiCp with the composite are the utmost important factors. These improve the mechanical properties enormously, however reduce the machining performance. Hence the WEDM experiments are conducted by varying the particulate size, volume fraction, pulseon time, pulseoff time and wire tension. In the view of quality cut, the most important performance indicators of WEDM as surface roughness （Ra）, metal removal rate （MRR）, wire wear ratio （WWR）, kerf （Kw） and white layer thickness （WLT） are measured as respon ses. PCA is used as multiresponse optimization technique to derive the composite principal component （CPC） which acts as the overall quality index in the process. Consequently, Taguchi＇s S/N ratio analysis is applied to optimize the CPC. The derived optimal process responses are confirmed by the experimental validation tests results. The analysis of vari ance is conducted to find the effects of choosing process variables on the overall quality of the machined component.The practical possibility of the derived optimal process conditions is also presented using SEM.  相似文献   

3.
The aims of the study were to census and compare the technological pedagogical and content knowledge （TPACK） of secondary science teachers and their most used information and communication technology （ICT） in two contexts, Taiwan and Shaanxi Province in China. A questionnaire was employed to examine secondary school science teachers＇ most used ICT and their TPACK in science teaching. Eight hundred and six secondary science teachers from Taiwan and 164 teachers from Shaanxi participated in the study. The analytical results showed that multimedia was the most used ICT in Taiwan, followed by PowerPoint （PPT）, Internet platforms, and interactive whiteboards （IWBs）. In Shaanxi, PPT was the most used ICT reported by science teachers, followed by multimedia, IWBs, and Intemet platforms. The findings indicated that in Taiwan, science teachers＇ TPACK was statistically significant in relation to different types of ICT, whereas in Shaanxi, science teachers＇ TPACK did not demonstrate significant difference. In Taiwan, science teachers who reported their most used ICT to be multimedia were found to show significant differences in TPACK according to gender and teaching experience. In Shaanxi, science teachers who reported their most used ICT to be PPT did not show any significant difference on TPACK by gender; however, they showed significant differences on TPACK in regard to teaching experience. The research implications of this study are provided below along with suggestions for future research.  相似文献   

4.
Hermetic packaging is often an essential requirement to enable proper functionality throughout the device＇s lifetime and ensure the optimal performance of a micro electronic mechanical system （MEMS） device. Solid-liquid interdiffusion （SLID） bonding is a novel and attractive way to encapsulate MEMS devices at a wafer level. SLID bonding utilizes a low-melting-point metal to reduce the bonding process temperature; and metallic seal rings take out less of the valuable surface area and have a lower gas permeability compared to polymer or glass- based sealing materials. In addition, ductile metals can adopt mechanical and thermo-mechanical stresses during their service lifetime, which improves their reliability. In this study, the principles of Au-Sn and Cu-Sn SLID bonding are presented, which are meant to be used for wafer-level hermetic sealing of MEMS resonators. Seal rings in 15.24 cm silicon wafers were bonded at a width of 60 gin, electroplated, and used with Au-Sn and Cu-Sn layer structures. The wafer bonding temperature varied between 300 ℃ and 350 ℃, and the bonding force was 3.5 kN under the ambient pressure, that is, it was less than 0.1 Pa. A shear test was used to compare the mechanical properties of the interconnections between both material systems, in addition, important factors pertaining to bond ring design are discussed according to their effects on the failure mechanisms. The results show that the design ofmetal structures can significantly affect the reliability of bond rings.  相似文献   

5.
There are many studies that focus on factors affecting achievement. However, there is limited research that used student characteristics indices reported by the Programme for International Student Assessment （PISA）. Therefore, this study investigated the predictive effects of student characteristics on mathematics performance of Turkish students. In PISA studies, sampling design, sampling weights, and plausible values have to be taken into consideration in order not to have biased multiple regression results. In order to conduct multiple regression analyses in PISA, software called the International Association for the Evaluation of Educational Achievement （lEA） International Database （IDB） Analyzer is required to be used because the dependent variable consists of several plausible values. This study aims to identify student characteristics that are significant in predicting mathematics performance in Turkey. Results showed that being successful in mathematics is a combination of several factors in which students＇ beliefs, motivation, and other factors must be organized to achieve mathematics. Among these beliefs and motivation, strong self-efficacy, positive self-concept, and minimum level of anxiety seem to be the key for success.  相似文献   

6.
Effective assessment is vital in educational activities. We propose IWAS （intelligent Web-based assessment system）, an intelligent, generalized and real-time system to assess both learning and teaching. IWAS provides a foundation for more efficiency in instructional activities and, ultimately, students＇ performances. Our contributions are summarized as （1） Given the causes （student knowledge levels and learning styles）, BN （Bayesian Networks） technique is utilized to automatically reason on the probabilities of the presence of the effects （learning outcomes）; （2） The absence of teaching practice assessments is addressed via the feedbacks from three different levels, aiming to correlate the teaching assessment with the learning assessments for the improved effectiveness in instructional activities; （3） Under a client/server architecture, IWAS is decomposed into a set of independent modules; through the standard inter-module interfaces, the flexibility of easy maintenance makes IWAS a generalized system adaptable to different domains; and （4） Web technologies are integrated to deliver the formative feedbacks to users in a timely manner  相似文献   

7.
The Internet penetrates deeply into the everyday life due to the availability of broadband networks and mobile devices. The widespread of the Internet, along with the development of innovative services, social networking, and tools （known as Web 2.0）, gives rise to the phenomenon of the digital world. A university striving not to be ＂an ivory tower＂ should meet the needs of the ＂Net Generation＂, prepare the graduates for professional work and life in the digital world and comply with the social demand for providing lifelong learning services, especially, in the vulnerable crisis times. MESI （Moscow State University of Economics, Statistics, and lnformatics） started implementing ICTs （information and communication technologies） both in the academic and administrative processes more than 15 years ago. Today, its unified e-learning environment allows rendering educational services to students of all levels and forms （both on-campus and off-campus） and 24 × 7 × 365 support （24 hours-7 days in a week-365 days in a year）. Information system for administration comprises electronic document management systems, students＇ records, and the results of their individual learning activities for the current, interim, and final assessment. The university management system empowers centralized management of its Moscow headquarters and branches, as well as regulation of teaching/learning process. Long-term development of education in Russia is directly dependent on large-scale introduction of e-learning tools, design and implementation of new methods of organization of educational process on its base, creating and using an appropriate electronic teaching and learning practices, and new approaches to the management of the education system and educational institutions.  相似文献   

8.
CSL （Chinese as a second language） learning is an emergency task in Taiwan, especially when more and more new immigrants joined in Taiwan. However, there are just a few new immigrants who can finish all language courses. For this reason, this research intends to provide a training system to assist new immigrants observing and learning the phrase structure. In this paper, the researchers design a system which can help new immigrants to form Chinese sentences by applying colligation and collocation technology.  相似文献   

9.
Manufacturing of solid oxide fuel cell （SOFC） components remains nowadays a key point for the indus- trial development of this technology. Especially, the deposition of the dense electrolyte layer which is sand- wiched between the porous anode and the porous cathode is of paramount importance and thus focuses a lot of attention. Therefore, this paper considers and reviews recent developments concerning solid electrolyte layers manufacturing using thermal spray （TS） and physical vapour deposition （PVD） technologies.  相似文献   

10.
Fabrication method and device of ultra-small gradient-index （GRIN） fiber probe were investigated in order to explore the development of ultra-small probes for optical coherence tomography （OCT） imaging. The beam- expanding effect of no-core fiber （NCF） and the focusing properties of the GRIN fiber lens were analyzed based on the model of GRIN fiber probe consisting of single-mode fiber （SMF）, NCF and GRIN fiber lens. A stereo micro- scope based system was developed to fabricate the GRIN fiber probe. A fiber fusion splicer and an ultrasonic cleaver were used to weld and cut the fiber respectively. A con- focal microscopy was used to measure the dimensions of probe components. The results show that the sizes of probe components developed are at the level of millimeter. Therefore, the proposed experimental system meets the fabrication requirements of an ultra-small self-focusing GRIN fiber probe. This shows that this fabrication device and method can be employed in the fabrication of ultra- small self-focusing GRIN fiber probe and applied in the study of miniaturized optical probes and OCT systems.  相似文献   

11.
This paper presented an automatic gain control(AGC) circuit suitable for FM/cw ladar. The proposed architecture was based on two-stage variable gain amplifier(VGA) chain with a novel DC offset canceller circuit, which contained an improved Gilbert cell and a Gm-C feedback loop. To keep the VGA with a linearity in dB characteristic, an improved exponential gain control circuit was introduced. The AGC was implemented in 0.18 μm standard CMOS process. Simulation and measurement results verified that its gain ranged from-20 dB to 30 dB, and bandwidth ranged from 100 kHz to 10 MHz. Its power consumption was 19.8 mW under a voltage supply of 3.3 V.  相似文献   

12.
Intuitive and efficient interfaces for human- robot interaction （HRI） have been a challenging issue in robotics as it is essential for the prevalence of robots supporting humans in key areas of activities. This paper presents a novel augmented reality （AR） based interface to facilitate human-virtual robot interaction. A number of human-virtual robot interaction methods have been for- mulated and implemented with respect to the various types of operations needed in different robotic applications. A Euclidean distance-based method is developed to assist the users in the interaction with the virtual robot and the spatial entities in an AR environment. A monitor-based visualization mode is adopted as it enables the users to perceive the virtual contents associated with different interaction methods, and the virtual content augmented in the real environment is informative and useful to the users during their interaction with the virtual robot. Case researches are presented to demonstrate the successful implementation of the AR-based HRI interface in planning robot pick-and-place operations and path following operations.  相似文献   

13.
Average retention after a didactic lecture is around 5% of the content. Active learning like discussion forums and teaching others make the retention rate to surpass 70%. Peer-Assisted Learning （PAL） is an effective method that makes active learning interesting and productive. However, drawbacks like minimal focus, bad structuring of content materials, poor time management, and other channels of distraction can limit the effectiveness of the sessions. Using our experience in the use of this teaching tool, student feedback, and literature review, we drafted a check list for the successful and meaningful use of PAL. Content material was decided on students＇ felt needs, like requests for revision of a particular topic or module. The content material was structured allowing periods of purposeful distraction by weaving in information on movies, sports, and novels, thereby, directing students to desired knowledge. The facilitators were trained to ensure that the focus of the group was not compromised, the timings were maintained, and involvement of all was secured. The use of Wi-Fi and referral books from the library was encouraged to shift the paradigm from passive learning to active application-based learning, and the feedback from the facilitators and participants was seriously considered to improvise future sessions. From the research results, we have found that these strategies were useful and envisaged that the application of these tips can help maximize learner engagement and learning. PAL is associated with cognitive, pedagogical, attitudinal, social, and economic benefits. Students take onus of their learning and even start to enjoy the process. This helped AIMST University stage the first national level convention on PAL in 2012, and our team of student facilitators attributes winning international quizzes based on the experience gained from PAL sessions.  相似文献   

14.
The translation of an instrument from one language to another is a challenging yet useful procedure, especially for constructs not widely studied in the target language. Culture shock is one such construct. The Culture Shock Questionnaire （CSQ） developed in England was translated to Turkish. Translation/back translation with 12 translators, the committee approach, and empirical testing in the university student population were the techniques employed. The results support CSQ as a potential instrument in the Turkish language as well as suggest that challenges in the translation of a research instrument, like challenges in the translation of other texts, involve serious dilemmas about the extent of loyalty to the original instrument. The current study recommends the use of multiple techniques in translation and reports on committee decisions in detail.  相似文献   

15.
The research questions being asked are： 1. How do architectural students learn with mobile technology？ and 2. What predictors lead to satisfaction in a mobile learning （M-Learning） environment？ It is understood that environment and culture contribute to the development of cognition. Critical pedagogical and constructivist theories ground this research with the view that ＂one learns from their experiences with their environments＂. The methodology used in this research includes both quantitative and qualitative methods： case studies and surveys. This research investigates how mobile technology is influencing learning. Outcomes of this research include a better understanding of how students learn with present technology, their preferred mobile devices, barriers to M-Learning, methods by which students learn best, and suggestions on how to improve M-Learning. Other outcomes of this research are the identification of variables leading to student satisfaction with M-Learning.  相似文献   

16.
Ma  Yan-hong 《美中教育评论》2013,(9):702-706
Since Krashen put forward the Affective Filter Hypothesis, more and more concern has been paid to the anxiety problem in Second and foreign language teaching and learning. Meanwhile, CL （cooperative learning） has gained much attention in recent years, both at home and abroad. Most researches （Oxford ＆ Ehrman, 1993; Kagan, 1994; Slavin, 1995） on CL indicated that CL is a classroom procedure which can lower anxiety and improve learning outcomes. Although the researches abroad have suggested that CL has a positive impact on reducing foreign language learning anxiety, few empirical researches on CL have been conducted in China. Moreover, according to the author＇s observation, anxiety is most obvious in oral English activities. Therefore, this thesis attempts to investigate some Chinese non-English freshmen＇s foreign language learning anxiety. Two classes are involved in the study： one as the experimental class instructed with CL method, the other as the control class taught with the traditional teaching method. By using a classical instrument, the FLCAS （foreign language classroom anxiety scale）, this study examined the subjects＇ foreign language learning anxiety. According to the analysis and comparison of the first and second FLCAS, the author finds CL has a significant effect on reducing students＇ foreign language learning anxiety.  相似文献   

17.
It is of great importance to obtain good collocation knowledge for fluent and appropriate language use as many words are used in a limited set of collocations. Studies on cognitive linguistics show that cognitive factors play an important role in collocation study as most collocations are metaphorically motivated, and that collocational behavior is influenced by a number of factors, including the semantics of the individual items themselves, the influence of other well-established meanings, the influence of metaphor, the influence of semantic prosody, etc.. Therefore, it is significant to explain and teach certain types of collocations in language teaching by considering the underlying factors which influence the collocational process. Chinese English as a foreign language （EFL） learners have some special collocation problems in their English learning, which not only result from grammatical incompetence, but also from their lack of conceptual fluency and metaphor competence. The disclosure of similarities and differences between the conceptual systems of English and Chinese will help to illuminate the nature of negative transfer of their first language in collocation acquisition of Chinese EFL learners. The author of the paper, by disclosing the interaction between collocation and metaphor from cognitive, linguistic, and social perspectives, proposes semantic-oriented principle, pragmatics-oriented principle, and culture-oriented principle to incorporate cognitive factors to collocation teaching. It is suggested that stress should be given to the teaching of conceptual metaphor and its mechanisms in collocation teaching before students can finally improve collocation competence with a focus on metaphor awareness.  相似文献   

18.
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19.
In order to explore effective ways to develop Chinese English learners＇ communicative competence, this study first briefly reviews the advantages of communicative language teaching （CLT） method which widely practiced in the Western countries and analyzes in details its obstacles in Chinese classroom context. Then it offers guidelines for compromising the communicative approach with the traditional Chinese approach. Finally, it puts forward some principles and techniques for English teaching practice in the Chinese environment.  相似文献   

20.
Due to the globalization and the spread of the Internet, distance learning （D-learning） has gained extraordinary impulse in recent years by classes broadcasted by Websites and assignments fulfilled by students in their own computers. D-learning facilitates the access to education to those people who are working or have low buying power due to its reduced cost and time convenience. Although D-learning has existed in the world for over 150 years, only in the last decades, it has become the focus of academic studies and researches in a systematic way. In this context, the objective of this research is to evaluate the impact of computer literacy on the academic performance of the D-learning students of Faculdade lnterativa COC--EAD （COC--D-learning Interactive College）, P61o Lafaiete （Lafaiete Branch）, Ribeirao Preto. The research consisted of a questionnaire with 21 qualitative dichotomous questions, concerning the level of knowledge and mastery of information techdologies, besides the gender and academic performance （weighted average and marks of the last module）. The data were tabulated, being considered two main variables： （a） academic performance, represented by the marks of the last module; and （b） computer literacy, represented by the sum of the questions concerning this matter. The data were analyzed statistically, and the correlation between the two variables considered was analyzed by Pearson＇s Correlation Test. The interviews of the 54 interviewees （24 males （44.45%） and 30 females （55.55%）） taking the business administration course were analyzed. The correlation coefficient r = 0.303 indicates that there is a meaningful correlation between the students＇ academic performance （marks） and their computer literacy, that is, the greater the computer literacy, the better the marks obtained by these students in the D-learning course. D-learning has computing as its main tool, theretbre, the students with less computer literacy find barriers in D-learning, which o ref  相似文献   

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