177,791 research outputs found
Projection reconstruction MR microscopy for the ex vivo evaluation of trabecular bone structure
No full text
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe 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
Magnetic resonance microscopy for the quantitative analysis of trabecular bone architecture
No full textPower spectral analysis of R-R interval Variability in Congenital Central Hypoventilation Syndrome
No full textConflict Detection Performance of Non-Cooperative Sensing Architectures for Small UAS Sense and Avoid
No full textThe safe integration of Unmanned Aircraft Systems in the civil airspace requires the development of Sense and Avoid (also named Detect and Avoid) systems, which represent a technology needed to detect a threat (e.g., an intruder vehicle) and, consequently, command a maneuver suitable to avoid collision within a small amount of time. In this framework, this paper presents a quantitative assessment of conflict detection performance achievable by different sensing architectures, which can be designed and installed on board of small Unmanned Aerial Vehicles. The attention is focused on non-cooperative systems, which can rely on active sensors (such as radars and LIDARs), passive sensors (such as visual cameras) or multi-sensor-based solutions. The aim is to quantitatively identify the potentialities and limitations of each technological solution. The analysis is carried out by means of a numerical simulation environment able to reproduce horizontal collision scenarios. Specifically, conflict detection performance is expressed in terms of two probabilities, namely the probability of missed conflict detection and false conflict detection, which are evaluated as a function of three parameters which allow uniquely defining the collision scenario, i.e., the time to and distance at the closest point of approach and the azimuth of the intruder with respect to the velocity vector of the ownship. Since, the probability determination process includes the effect of tracking uncertainties (i.e., probability of firm tracking and false track generation), this analysis also allows highlighting the diverse but interconnected effects of sensing accuracy and detection range
Quantitative magnetic resonance imaging to assess bone quality in patients with osteogenesis imperfecta
No full text"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.
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
- …
