1,720,998 research outputs found
All-optical measurement of the hot electron sheath driving laser ion acceleration from thin foils
We present experimental results from an all-optical diagnostic method to directly measure the evolution of the hot-electron distribution driving the acceleration of ions from thin foils using high-intensity lasers. Central parameters of laser ion acceleration such as the hot-electron density, the temperature distribution and the conversion efficiency from laser pulse energy into hot electrons become comprehensively accessible with this technique.Deutsche Forschungsgemeinschaft (DFG) (contract number TR18)Germany. Bundesministerium für Bildung und Forschung (contract number 03ZIK445)Germany. Bundesministerium für Bildung und Forschung (contract number 03ZIK052
Architecting complex international science, technology and innovation partnerships (CISTIPs): A study of four global MIT collaborations
Complex international partnerships have emerged as a policy instrument of choice for many governments to build domestic capacity in science, technology and innovation with the help of foreign partners. At present,
these flagship initiatives tend to be primarily practitioner-driven with limited systematic understanding of available design options and trade-offs. Here, we present an analysis of four such partnerships from the university
sector between the Massachusetts Institute of Technology (MIT) and governments in the UK, Portugal, Abu Dhabi, and Singapore. Using a system architecture approach in conjunctions with in-depth case studies and elements of interpretive policy analysis, we map how in each country distinct capacity-building goals, activities, and political and institutional contexts translate into different partnership architectures: a bilateral hub-&-spokes architecture (UK), a consortium architecture (Portugal), an institution-building architecture (Abu Dhabi), and a functional expansion architecture (Singapore). Despite these differences in emergent macro-architectures, we show that each partnership draws on an identical, limited set of ‘forms’ that can by organized around four architectural views (education, research, innovation & entrepreneurship, institution-building) and four levels of interaction between partners (people, programs/projects, objects, organization/process). Based on our analysis, we derive a design matrix that can help guide the development future partnerships through a systematic understanding of available design choices. Our research underscores the utility and flexibility of complex international partnerships as systemic policy instruments. It suggests a greater role for global research universities in capacity-building and international development, and emphasizes the potential of targeted cross-border funding. Our research also demonstrates the analytic power of system architecture for policy analysis and design. We argue that architectural thinking provides a useful stepping stone for STS-type interpretive policy analysis into national innovation initiatives in different political cultures, as well as more custom-tailored approaches to program evaluationNational Science Foundation (U.S.) Science of Science and Innovation Policy (Collaborative Grant 1262263)MIT-Portugal ProgramMassachusetts Institute of Technology. Leading Technology Policy Initiativ
A cascaded laser acceleration scheme for the generation of spectrally controlled proton beams
We present a novel, cascaded acceleration scheme for the generation of spectrally controlled ion beams using a laser-based accelerator in a 'double-stage' setup. An MeV proton beam produced during a relativistic laser–plasma interaction on a thin foil target is spectrally shaped by a secondary laser–plasma interaction on a separate foil, reliably creating well-separated quasi-monoenergetic features in the energy spectrum. The observed modulations are fully explained by a one-dimensional (1D) model supported by numerical simulations. These findings demonstrate that laser acceleration can, in principle, be applied in an additive manner.Deutsche Forschungsgemeinschaft (DFG contract no. TR18)Deutsche Forschungsgemeinschaft (contract no. 03ZIK052)European Union (Laserlab Europe
Going Beyond Counting First Authors in Author Co-citation Analysis
The present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
We provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
We conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
We have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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