空间高精度定位姿柔顺工作平台输入输出模型的研究     

谢先海  廖道训 《上海大学学报(英文版)》2002,6(1):85-91

A precise micro-location compliant stage with elastics-supported system is enmployed for investigations.The general motion of stage supported by elastic structure is described.The analyses of forward displecement and inverse displacement of stage are formulated.The study of input-output behavior of compliant mechanisms actually belongs to a stress-strain field problem.By using finite element analysis.the compliance coefficients of the stage supported by ring are calculated.Finally,a case is inverstigated to exemplity these formulae.  相似文献   

A long-term experiment to investigate the relationships between high school students’ perceptions of mobile learning and peer interaction and higher-order thinking tendencies     

Gwo-Jen Hwang  Chiu-Lin Lai  Jyh-Chong Liang  Hui-Chun Chu  Chin-Chung Tsai 《Educational technology research and development : ETR & D》2018,66(1):75-93

In this study, a one-year program was conducted to investigate the relationships between students’ perceptions of mobile learning and their tendencies of peer interaction and higher-order thinking in issue-based mobile learning activities. To achieve the research objective, a survey consisting of eight scales, namely, usability, continuity, adaptive content, collaboration, communication, problem-solving, critical thinking and creativity, was developed. A total of 658 students from 38 high schools in Taiwan filled in the questionnaire after experiencing issue-based mobile learning activities. From the exploratory and confirmatory factor analyses, it was found that the questionnaire had high reliability and validity. The structural equation model further revealed that the provision of adaptive content in the mobile learning had positive impacts on the students’ tendency to interact with peers (i.e., collaboration and communication), which further affected their tendency to engage in higher-order thinking (i.e., problem-solving, critical thinking, and creativity). The findings of this study provide a good reference for researchers and school teachers who intend to promote mobile learning in school settings.  相似文献   

Between two Advisors: Interconnecting Academic and Workplace Settings in an Emerging Field     

Kaisa Hytönen  Tuire Palonen  Erno Lehtinen  Kai Hakkarainen 《Vocations and Learning》2016,9(3):333-359

This article examines a new training design for continuing professional development that aims to support the learning of the novel knowledge and skills needed in emerging professional fields by interconnecting academic and workplace settings. The training design is based on using two advisors, one from working life and the other from an academic context. The article examined whether participants’ personal orientation to adaptive expertise predicts the success of a guidance process. The interconnection of workplace and academic contexts was expected to occur through guidance practices. In addition, the features underlying the most successful guidance relationships were analysed. Data were collected by conducting repeated semi-structured interviews with 18 course participants, eight academic advisors and eight workplace advisors in the context of a 1-year energy efficiency training programme. The results indicated that a trainee’s personal orientation towards adaptive expertise is a significant component in successful guidance processes. An interconnection of workplace and academic knowledge and practices was hardly found in the guidance provided by each participant’s academic and workplace advisors. The feature underlying the most successful guidance relationships are related at the personal, dyad and context levels. An excellent match between the expert profiles of the learner and the advisor appears to be especially critical for successful guidance and powerful knowledge exchange in emerging fields. However, finding matching advisors is often challenging. Many problems are presumably solved if these ‘right persons’ can be found and if the trainees are themselves oriented to utilise the novel resources provided to them by the advisors.  相似文献   

Students’ Development of Representational Competence Through the Sense of Touch     

Alejandra J. Magana  Sadhana Balachandran 《Journal of Science Education and Technology》2017,26(3):332-346

Electromagnetism is an umbrella encapsulating several different concepts like electric current, electric fields and forces, and magnetic fields and forces, among other topics. However, a number of studies in the past have highlighted the poor conceptual understanding of electromagnetism concepts by students even after instruction. This study aims to identify novel forms of “hands-on” instruction that can result in representational competence and conceptual gain. Specifically, this study aimed to identify if the use of visuohaptic simulations can have an effect on student representations of electromagnetic-related concepts. The guiding questions is How do visuohaptic simulations influence undergraduate students’ representations of electric forces? Participants included nine undergraduate students from science, technology, or engineering backgrounds who participated in a think-aloud procedure while interacting with a visuohaptic simulation. The think-aloud procedure was divided in three stages, a prediction stage, a minimally visual haptic stage, and a visually enhanced haptic stage. The results of this study suggest that students’ accurately characterized and represented the forces felt around a particle, line, and ring charges either in the prediction stage, a minimally visual haptic stage or the visually enhanced haptic stage. Also, some students accurately depicted the three-dimensional nature of the field for each configuration in the two stages that included a tactile mode, where the point charge was the most challenging one.  相似文献   

How fast can we read in the mind? Developmental trajectories of silent reading fluency     

Massimo Ciuffo  Jane Myers  Massimo Ingrassia  Antonio Milanese  Maria Venuti  Ausilia Alquino  Alice Baradello  Giacomo Stella  Antonella Gagliano 《Reading and writing》2017,30(8):1667-1686

The silent reading fluency is not an observable behaviour and, therefore, its evaluation is perceived as more challenging and less reliable than oral reading fluency. The present research is aimed to measure the silent reading speed in a sample of proficient students, assessed by an original silent reading fluency task, based on behavioural indicators of the silent reading speed. A total of 325 high school and university skilled students (age range 14–23 years) have been assessed using 3 tasks aimed to evaluate the oral reading speed (lists of words, lists of pseudowords and narrative text) and one task aimed to measure the silent reading speed. The average silent reading speed in our sample was around 12.5 syll/sec, almost double than the oral reading speed rate. The silent reading speed had an increase from 9.13 to 12.38 syll/sec from the first year of high school (ninth grade) to the fifth year of University. Conversely, the oral reading speed remained substantially unchanged for the entire academic course. Our results showed that the reading fluency in silent mode tends to increase up to the last years of University and it may be considered the most rapid and efficient reading mode. This study highlights the importance of including both silent and oral reading modes in the assessment of the older students and young adults, since silent reading is the main reading mode for proficient readers.  相似文献   

集群式计算机系统在生物信息学中的应用     

周澄  郁松年 《上海大学学报(英文版)》2003,7(4):370-374

1　Introduction　SMP (symmetricmulti processing)andMPP (mas sivelyparallelprocessing)arethetwotypesofstruc tureofparallelcomputing .　Symmetricmulti processingsystemshavemultipleCPUsattachedtothesamebusandsharingRAM .Massivelyparallelprocessingisthecooperated pro cessingofaprogrambymultipleprocessorsthatworkondifferentpartsoftheprogram ,witheachprocessorusingitsownoperatingsystemandmemory .ThechoicebetweenSMPandMPPdependsonthenatureoftheproblembeingsolved .Iftheproblemcanbeeasilypartit…  相似文献   

Optimal restructuring strategies under various dynamic factors     

MENG Qing-xuan 《浙江大学学报(A卷英文版)》2007,8(6):932-938

Corporate restructuring was identified as a new industrial force that has great impact on economic values and that therefore has become central in daily financial decision making. This article investigates the optimal restructuring strategies under different dynamic factors and their numerous impacts on firm value. The concept of quasi-leverage is introduced and valuation models are built for corporate debt and equity under imperfect market conditions. The model＇s input variables include the quasi-leverage and other firm-specific parameters, the output variables include multiple corporate security values. The restructuring cost is formulated in the form of exponential function, which allows us to observe the sensitivity of the variation in security values. The unified model and its analytical solution developed in this research allow us to examine the continuous changes of security values by dynamically changing the coupon rates, riskless interest rate, bankruptcy cost, quasi-leverage, personal tax rate, corporate taxes rate, transaction cost, firm risk, etc., so that the solutions provide useful guidance for financing and restructuring decisions.  相似文献   

Distributed Cognition as a Lens to Understand the Effects of Scaffolds: The Role of Transfer of Responsibility     

Brian R. Belland 《Educational Psychology Review》2011,23(4):577-600

Problem solving is an important skill in the knowledge economy. Research indicates that the development of problem solving skills works better in the context of instructional approaches centered on real-world problems. But students need scaffolding to be successful in such instruction. In this paper I present a conceptual framework for understanding the effects of scaffolding. First, I discuss the ultimate goal of scaffolding—the transfer of responsibility—and one way that scholars have conceptualized promoting this outcome (fading). Next, I describe an alternative way to conceptualize transfer of responsibility through the lens of distributed cognition and discuss how this lens informs how to promote transfer of responsibility. Then I propose guidelines for the creation of problem solving scaffolds to support transfer of responsibility and discuss them in light of the literature.  相似文献   

Theory to reality: a few issues in implementing problem-based learning   总被引：1，自引：0，他引：1  

Woei Hung 《Educational technology research and development : ETR & D》2011,59(4):529-552

The success of an intervention depends not only upon its theoretical soundness, but also on proper implementation that reflects the guidelines derived from its theoretical conception. Debates surrounding the effectiveness of problem-based learning (PBL) have focused on its theoretical conception and students’ learning outcomes, but implementation is seemingly absent from the picture. This paper attempts to describe what research evidence is needed to fill in this missing information and provide a clearer picture of PBL. The author examines current PBL implementation practices and identifies potentially confounding variables that may play a role in inconsistent or conflicting research results in PBL. For example, various models of PBL have been developed and implemented to afford the specific instructional needs of the institution or learner population. These PBL models are in fact quite different in terms of the nature of problem solving and the degrees of self-directed learning, which theoretically, should result in different types of learning outcomes. Without distinguishing the models used, the results of comparative PBL research could have been confounded. Furthermore, human factors are another set of confounding variables that could influence the students’ learning processes and consequently affect PBL implementations and research results. To remedy these problems and reach PBL’s full potential, as well as obtain a more accurate picture of PBL as an instructional method and its effects on students’ learning, some fundamental changes are needed.  相似文献   

Effect of postsecondary education on the economic status of persons who are deaf or hard of hearing     

Schley S  Walter GG  Weathers RR  Hemmeter J  Hennessey JC  Burkhauser RV 《Journal of deaf studies and deaf education》2011,16(4):524-536

This article examines the effect that postsecondary education has on earnings and the duration of time spent in the Social Security disability programs for young persons who are deaf or hard of hearing. Our hypothesis is that investments in postsecondary training increase the likelihood of employment for persons who are deaf or hard of hearing and thus reduce dependency on disability-related income support programs. A longitudinal data set based upon records from the National Technical Institute for the Deaf and Social Security administrative records is used for this analysis. We find that those who graduate, even those who graduate with vocational degrees, experience significant earnings benefits and reductions in the duration of time spent on federal disability programs when compared with those who do not graduate with a degree. This finding suggests that reductions in the duration of time spent on Social Security programs are not limited to those with the highest level of scholastic aptitude and that investments in post-secondary education can benefit a broad group of deaf and hard-of-hearing persons. In addition, the data show that individuals who attend college, but withdraw before graduation, fair no better economically than individuals who never attended college.  相似文献