628,228 research outputs found

    Probing scattering phase shifts by attosecond streaking

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    Attosecond streaking is one of the most fundamental processes in attosecond science allowing for a mapping of temporal (i.e. phase) information on the energy domain. We show that on the single-particle level attosecond streaking time shifts contain spectral phase information associated with the Eisenbud-Wigner-Smith (EWS) time delay, provided the influence of the streaking infrared field is properly accounted for. While the streaking phase shifts for short-ranged potentials agree with the associated EWS delays, Coulomb potentials require special care. We show that the interaction between the outgoing electron and the combined Coulomb and IR laser fields lead to a streaking phase shift that can be described classically

    Information Science in the web era: a term-based approach to domain mapping.

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    International audienceWe propose a methodology for mapping the research in Information Science (IS) field based on a combined use of symbolic (linguistic) and numeric information. Using the same list of 12 IS journals as in earlier studies on this same topic (White & McCain 1998 ; Zhao & Strotmann 2008a&b), we mapped the structure of research in IS for two consecutive periods: 1996-2005 and 2006-2008. We focused on mapping the content of scientific publications from the title and abstract fields of underlying publications. The labels of clusters were automatically derived from titles and abstracts of scientific publications based on linguistic criteria. The results showed that while Information Retrieval (IR) and Citation studies continued to be the two structuring poles of research in IS, other prominent poles have emerged: webometrics in the first period (1996-2005) evolved into general web studies in the second period, integrating more aspects of IR research. Hence web studies and IR are more interwoven. There is still persistence of user studies in IS but now dispersed among the web studies and the IR poles. The presence of some recent trends in IR research such as automatic summarization and the use of language models were also highlighted by our method. Theoretic research on "information science" continue to occupy a smaller but persistence place. Citation studies on the other hand remains a monolithic block, isolated from the two other poles (IR and web studies) save for a tenuous link through user studies. Citation studies have also recently evolved internally to accommodate newcomers like "h-index, Google scholar and the open access model". All these results were automatically generated by our method without resorting to manual labeling of specialties nor reading the publication titles. Our results show that mapping domain knowledge structures at the term level offers a more detailed and intuitive picture of the field as well as capturing emerging trends

    A scientometric analysis and review of fall from height research in construction

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    Fall from height (FFH) in the construction industry has earned much attention among researchers in recent years. The present review-based study introduced a science mapping approach to evaluate the FFH studies related to the construction industry. This study, through an extensive bibliometric and scientometric assessment, recognized the most active journals, keywords and the nations in the field of FFH studies since 2000. Analysis of the authors’ keywords revealed the emerging research topics in the FFH research community. Recent studies have been discovered to pay more attention to the application of Computer and Information Technology (CIT) tools, particularly building information modelling (BIM) in research related to FFH. Other emerging research areas in the domain of FFH include rule checking, and prevention through design. The findings summarized the mainstream research areas (e.g., safety management program), discussed existing research gaps in FFH domain (e.g., the adaptability of safety management system), and suggests future directions in FFH research. The recommended future directions could contribute to improving safety for the FFH research community by evaluating existing fall prevention programs in different contexts; integrating multiple CIT tools in the entire project lifecycle; designing fall safety courses to workers associated with temporary agents and prototype safety knowledge tool development. The current study was restricted to the FFH literature sample included the journal articles published only in English and in Scopus

    Using enriched skeleton concept mapping to support meaningful learning

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    Abstract. There has been significant interest among researchers in the instructional use of concept maps and collaboration scripts. Some studies focus on students' collaboration on concept mapping tasks; others focus on scripts to structure learning tasks and guide interactions. Little is known about scripted collaborative concept mapping. This article reports a study in which we examine the effects on meaningful learning of scripting students' argumentative interactions during collaborative "enriched skeleton concept mapping". Each concept in the enriched skeleton concept map (ESCoM) contains "annotated factual multimedia information" and an embedded micro collaboration script. The study was performed in a Biomolecules course of the Bachelor of Applied Science program. First-year students were randomly assigned to an experimental group of 44 students and a control group of 49 students. In the experimental group, students worked together in pairs on an ESCoM guided by embedded collaboration scripts. The control group received the regular course. The results show that students were able to handle and appreciate the enriched skeleton concept mapping products and processes. Moreover, concept maps appeared to be scored reliable and validly. Finally, the regular course exam showed that the experimental group outperformed the control group. Enriched skeleton concept mapping resulted in a better understanding of the conceptual structure of the domain, the concepts and their relations
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