Google Scholar's Coverage of the Engineering Literature 10 years Later     

Carmen Cole  Angela R. Davis  Vanessa Eyer  John J. Meier 《The Journal of Academic Librarianship》2018,44(3):419-425

In 2008 Meier and Conkling first tested Google Scholar's coverage of the engineering literature against citations gathered from the Compendex database. Since that time, other studies have used the same methodology and found improvement in Google Scholar's coverage. This study uses engineering dissertations from Proquest Dissertations & Theses to create a data set of citations for the comparison of fee-based databases, Compendex and Scopus, against Google Scholar. From 1950 to 2017 Google Scholar outperformed both Compendex and Scopus in discoverability of citations in nine engineering subjects. These results have implications for collection management and information literacy program planning for librarians.  相似文献   

Building biophysics in China     

Howard Chiang 《Metascience》2016,25(2):225-227

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New insights into brazilwood lake pigments manufacture through the use of historically accurate reconstructions     

Tatiana Vitorino  Leslie Carlyle  Vanessa Otero 《文物保护研究》2016,61(5):255-273

A multi-analytical approach for the study of brazilwood and its lake pigments was carried out based on historically accurate reconstructions. Recipes for brazilwood lakes from the fifteenth century technical text Livro de como se fazem as cores and the Winsor & Newton nineteenth century colourman's archive were reproduced and compared. Both primary sources allowed for the successful preparation of brazilwood lake pigments with colours that vary from light pink to dark red. The main steps and ingredients for the manufacture of these pigments were common in both sources, particularly the addition of Al³⁺ in the form of alum, and calcium carbonate (chalk). Reconstructions revealed that the latter acts as a pH buffer and filler, controlling the pH at which the lake pigment precipitates. The main difference between the two sources is that the nineteenth century recipes give the quantities for all ingredients, the precise temperatures and time, and achieved higher relative pigment yields (75% versus 45%). Full chemical characterisation of the reconstructions provided detailed information on the individual steps in the pigment manufacture and revealed that the presence of calcium sulphate dihydrate (gypsum) in the final pigment was a result of its formation in situ. Infrared, reflectance, and fluorescence spectroscopy proved to be essential and complementary techniques: while infrared was used to characterise additives and binders, reflectance and fluorescence data were fundamental for identifying the chromophore. The pigments and paints produced can now be used as standards for the identification and investigation of brazilwood lake pigments found in artworks.  相似文献   

Coordination pattern of baseball pitching among young pitchers of various ages and velocity levels     

Hsiu-Hui Chen  Chiang Liu  Wen-Wen Yang 《Journal of sports sciences》2016,34(17):1682-1690

This study compared the whole-body movement coordination of pitching among 72 baseball players of various ages and velocity levels. Participants were classified as senior, junior, and little according to their age, with each group comprising 24 players. The velocity levels of the high-velocity (the top eight) and low-velocity (the lowest eight) groups were classified according to their pitching velocity. During pitching, the coordinates of 15 markers attached to the major joints of the whole-body movement system were collected for analysis. Sixteen kinematic parameters were calculated to compare the groups and velocity levels. Principal component analysis (PCA) was conducted to quantify the coordination pattern of pitching movement. The results were as follows: (1) five position and two velocity parameters significantly differed among the age groups, and two position and one velocity parameters significantly differed between the high- and low-velocity groups. (2) The coordination patterns of pitching movement could be described using three components, of which the eigenvalues and contents varied according to age and velocity level. In conclusion, the senior and junior players showed greater elbow angular velocity, whereas the little players exhibited a wider shoulder angle only at the beginning of pitching. The players with high velocity exhibited higher trunk and shoulder rotation velocity. The variations among groups found using PCA and kinematics parameter analyses were consistent.  相似文献   

Florida and Puerto Rico Secondary Science Teachers’ Knowledge and Teaching of Climate Change Science     

Benjamin C. Herman  Allan Feldman  Vanessa Vernaza-Hernandez 《International Journal of Science and Mathematics Education》2017,15(3):451-471

Misconceptions about climate change science are pervasive among the US public. This study investigated the possibility that these misconceptions may be reflective of science teachers’ knowledge and teaching of climate change science. Florida and Puerto Rico secondary science teachers who claim to teach extensively about climate change were surveyed in regard to their conceptions of climate change science and the climate change-related topics they teach. Results show that many teachers hold naïve views about climate change (e.g. that ozone layer depletion is a primary cause of climate change) and climate change science (e.g. that it must be based on controlled experiments for it to be valid). In addition, teachers in both groups neglect crucial topics such as how evidence for climate change is developed and the social, political, and economic dimensions of climate change. Our results suggest the need for teachers to understand how to teach climate change and the nature of climate change science using authentic contexts that promote effective socioscientific decision-making and climate change mitigation.  相似文献   

Joint rate control and scheduling for wireless uplink video streaming     

KATSAGGELOS Aggelos K. 《浙江大学学报(A卷英文版)》2006,7(5):801-810

INTRODUCTION Video streaming is becoming one of the major driving forces of next generation wireless networks. For the currently deployed cellular networks, the practical data rates are not enough to support full rate, high quality video applications. As a result, many research efforts have been devoted to adapting video content to reconcile the conflict between the high demand of video quality and the limited wireless communication resources among users. A large body of literature utiliz…  相似文献   

From Interaction to Intersubjectivity: Facilitating online group discourse processes     

Vanessa Paz Dennen  Kristina Wieland 《Distance Education》2007,28(3):281-297

This article examines the online discourse that took place in representative threads from two classes, seeking to document indicators that students did or did not engage in co‐construction of knowledge. Stahl's (2006 Stahl, G. 2006. Group cognition: Computer support for building collaborative knowledge, Cambridge, MA: MIT Press.  [Google Scholar]) social theory of computer supported collaborative learning (CSCL) is used along with discourse analysis methods to examine these course dialogues. Findings show the class that had a peer‐like, consistent facilitative instructor and discussion anchored around questions and shared artifacts was more likely to engage in discussion leading to the negotiation of knowledge and understanding. This class relied on social acknowledgements, questions, and shared exploration of perspectives and theories throughout their discussion. These elements and strategies appear to be important components that make up for lower levels of tacit understanding in online environments, thus enabling learners to interact in social learning processes. The other class, which lacked a facilitative instructor, did not have the same results. Although interaction levels were equal and students carried topical motifs such as the phrase “faster, better, cheaper” from message to message, students in this other class did not engage deeply or develop new understanding of the course material through the discussion.  相似文献   

Understanding the Use of Student-Centered Teaching Methods in Undergraduate Chemistry Courses     

Yoder  Ryan J.  Bobbitt-Zeher  Donna  Sawicki  Vanessa 《Research in Science Education》2019,51(2):845-863

A growing body of research suggests that student-centered teaching methods are associated with positive learning outcomes for undergraduate students. Yet, the extent of their use and factors leading to their adoption in fields, such as chemistry, continue to be under-explored. Utilizing survey data collected during 2015, we begin to fill this gap, first by considering the degree to which faculty and instructors use and plan to use various student-centered teaching methods in their undergraduate chemistry courses. Then, we examine three potential factors that may help us understand variation in (1) use of and (2) intentions to implement student-centered methods: attitudes toward teaching methods; teaching approaches; and institutional characteristics. Importantly, our findings suggest attitudes and individual teaching approaches are significant predictors of the use and intention to implement student-centered methods in the classroom. Perhaps surprisingly, several institutional factors examined (such as class size, percentage of time spent teaching, and type of institution) play no significant role. Given the positive student outcomes associated with various student-centered methods reported in literature, these findings suggest potential avenues for faculty and instructors’ professional development toward further implementation of these methods.

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Transition Services for Students with Intellectual Disabilities: A Case Study of a Public School Program on a Community College Campus     

Debra A. Neubert  Vanessa Alvarez Redd 《Exceptionality》2013,21(4):220-234

Students with intellectual disabilities aged 18–21 are increasingly receiving transition services on college campuses during the last years of public schooling. These students may attend college courses, work in the community, access community recreational activities, and engage in age-appropriate experiences with peers without disabilities. However, there is little research that documents the types of practices included, the perspectives of consumers, or the outcomes of these transition services. Results from this case study depict how one public school program on a community college campus incorporated recommended transition practices and how students with intellectual disabilities and their families perceived these practices.  相似文献   

Factors Affecting Retirement Attitude among Elementary School Teachers     

Wan-Chen Hsu  Chia-Hsun Chiang 《Educational gerontology》2015,41(8):590-603

This study investigated the relationships of teacher efficacy, perceived organizational control, and the teacher-student age gap with teachers’ retirement attitudes. Stratified random sampling was adopted to collect survey responses. A total of 498 valid surveys from 33 elementary schools were collected. Correlational analyses revealed significant positive correlations of efficacy for classroom management (teacher efficacy subdomain), efficacy for student engagement (teacher efficacy subdomain), efficacy for instructional strategies (teacher efficacy subdomain), and the teacher-student age gap with three subdomains of teacher retirement attitude. In addition, there were significant positive correlations of efficacy for instructional strategies and perceived organizational control with the cognitive and behavior subdomains of retirement attitude. Hierarchical regression analysis revealed that efficacy for classroom management can positively predict the affective and cognitive subdomains of retirement attitude. Perceived organizational control can positively predict retirement attitude and its cognitive and behavior subdomains. Finally, the teacher-student age gap can predict retirement attitude and all its subdomains. Discussion of the results and recommendations for future research are provided.  相似文献