130,478 research outputs found
Novel local/nonlocal formulation of the stress-driven model through closed form solution for higher vibrations modes
No full textIn the present work, an innovative two-phases local/nonlocal constitutive mixture model based on the stress-driven model for free vibrations problems is presented. The above two-phases model has been formulated by defining a convex combination of local/nonlocal phases through a mixture parameter and the closed form solution for free vibrations problems is given. The proposed local/nonlocal model has been applied to compute the natural frequencies of four nanobeams study cases. The results are presented in terms of normalised natural frequency as function of both nonlocal and mixture parameters. First, the influence of the two parameters is studied. The effectiveness of the present model is discussed by comparing the results with those obtained by applying the Gradient Elasticity theory. Finally, the normalised natural frequencies for the second, third and fourth modes of vibrations are presented and discussed for each study case
Approaches for mapping susceptibility to rockfalls initiation in carbonate rock-masses: a case study from the Sorrento coast (southern Italy)
No full textMost of the shoreline of the Campania region, Southern Italy, is characterized by steep and high rocky slopes, then several localities, densely populated and highly touristic attractive for the worldwide famous landscapes are exposed to an high rockfall risk. Particularly, the touristic localities on the Sorrentine Peninsula, such as Sorrento,
Vico Equense and Amalfi, can be considered among the most representative case-studies prone to the recurrent instability of rock blocks. Due to the frequent location of settlements and roads underneath and at very limited or null distances from the carbonate steep slopes, a diffuse condition of high rockfall risk exists. Consequently, the assessment of priorities in directing active remedial works to be carried out on the unstable rock slopes is still a challenging issue.
In order to find an effective method for assessing the susceptibility to rockfall initiation with approaches suitable for detailed mapping, a combined application of standard methods was tested.
The Romana’s Slope Mass Rating (SMR) and the Matheson’s graphical tests, for assessing the number of fundamental instability mechanisms, were applied in a test site of the Sorrento coast. Results of the two methods were separately evaluated and then combined in a new
rating approach by indexing the respective susceptibility classes. In addition, the number of joint sets and the macro-structural features of the rock-mass (faults and master joints) were considered. By means of statistical analyses of rockfalls occurred in the test area, the results obtained with the new combined approach were found
more accurate in assessing and mapping the most susceptible areas
Approaches for mapping susceptibility to slope instability in carbonate rock-masses: case studies from the Sorrento-Amalfi coast (southern Italy)
No full textMeSH term explosion and author rank improve expert recommendations
No full textInformation overload is an often-cited phenomenon that reduces the productivity, efficiency and efficacy of scientists. One challenge for scientists is to find appropriate collaborators in their research. The literature describes various solutions to the problem of expertise location, but most current approaches do not appear to be very suitable for expert recommendations in biomedical research. In this study, we present the development and initial evaluation of a vector space model-based algorithm to calculate researcher similarity using four inputs: 1) MeSH terms of publications; 2) MeSH terms and author rank; 3) exploded MeSH terms; and 4) exploded MeSH terms and author rank. We developed and evaluated the algorithm using a data set of 17,525 authors and their 22,542 papers. On average, our algorithms correctly predicted 2.5 of the top 5/10 coauthors of individual scientists. Exploded MeSH and author rank outperformed all other algorithms in accuracy, followed closely by MeSH and author rank. Our results show that the accuracy of MeSH term-based matching can be enhanced with other metadata such as author rank
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
No full textBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
- …
