191 research outputs found
A Tabu Search Approach for the Circle Packing Problem
No full textThis paper concerns the problem to place N non overlapping circles in a circular container with minimum radius. This is a well known and widely studied problem with applications in manufacturing and logistics and, in particular, to problems related to cutting and packing. In this paper we propose an algorithm that by applying a strength along a selected direction on each circle, simulates the shifting of circles on the plane and tries to reduce the radius of the circular container during this movements. The algorithm is based on a multistart technique where the starting solutions are produced by a tabu search heuristic that uses also the current best solution. The algorithm takes part in a public international contest in order to find optimal solutions to a special case in circle packing. The contest saw the participation of 155 teams and our algorithm achieved the tenth positio
A clinical approach to inherited arrhythmias
Get PDFIn the past decade, the discovery that cases of ventricular arrhythmias and sudden cardiac death (SCD) in young individuals potentially could be caused by an unrecognized genetic substrate has defined a new subset of cardiac conditions: inherited arrhythmogenic diseases (IADs).1 Although rare in clinical practice, these diseases are more common than previously thought. They represent a challenge for the arrhythmia specialist in terms of diagnosis and clinical management. The correct diagnosis of IADs, as well as the use and interpretation of the results of genetic testing, are not straightforward and require a specific expertise such as that provided by specialized and dedicated centers. Here we will review the general issues arising from the correct interpretation of genetic testing and its indications. We also will focus on the clinical management and use of genetic information in different inherited arrhythmias
Sediments and bedforms of the Harle tidal inlet (Wadden Sea, Germany)
No full textABSTRACTThe paper presents a map of sediment surface distribution and bedforms in the Harle tidal inlet, German Wadden Sea. Data collection, processing, and map editing were realized within the sublittoral mapping program of Lower Saxony national waters carried out by the NLWKN – Coastal Research Station. The map is the result of the combined use of multibeam echosounder, sub-bottom profiler, and ground-truth data. The sediment characterization is achieved by an unsupervised approach using an Object-Based Image Analysis (OBIA) on a normalized backscatter mosaic, verified by nineteen sediment samples. Morphometrical parameters and sub-bottom data provided important information to identify hard substrates and bedforms
Optical Analysis on Surfaces by Second-Harmonic Generation: Possible Applications to Tribology
No full textOptical analysis of surfaces by second harmonic generation: possible applications to the tribological field
No full textOptical Analysis on Surfaces by Second-Harmonic Generation: Possible Applications to Tribology
No full text
Optical analysis of surfaces by second harmonic generation: possible applications to the tribological field
No full textA review of last interglacial sea-level proxies in the western Atlantic and southwestern Caribbean, from Brazil to Honduras
Get PDFWe use a standardized template for Pleistocene sea-level data to review last interglacial (Marine Isotope Stage 5 - MIS 5) sea-level indicators along the coasts of the western Atlantic and southwestern Caribbean, on a transect spanning from Brazil to Honduras and including the islands of Aruba, Bonaire, and Curaçao. We identified six main types of sea-level indicators (beach deposits, coral reef terraces, lagoonal deposits, marine terraces, Ophiomorpha burrows, and tidal notches) and produced 55 standardized data points, each constrained by one or more geochronological methods. Sea-level indicators are well preserved along the Brazilian coasts, providing an almost continuous north-to-south transect. However, this continuity disappears north of the Rio Grande do Norte Brazilian state. According to the sea-level index points (discrete past position of relative sea level in space and time) the paleo sea-level values range from ~5.6 to 20m above sea level (a.s.l.) in the continental sector and from ~2 to 10ma.s.l. in the Caribbean islands. In this paper, we address the uncertainties surrounding these values. From our review, we identify that the coasts of northern Brazil, French Guiana, Suriname, Guyana, and Venezuela would benefit from a renewed study of Pleistocene sea-level indicators, as it was not possible to identify sea-level index points for the last interglacial coastal outcrops of these countries. Future research must also be directed at improving the chronological control at several locations, and several sites would benefit from the re-measurement of sea-level index points using more accurate elevation measurement techniques. The database compiled in this study is available in spreadsheet format at the following link: https://doi.org/10.5281/zenodo.5516444 (Version 1.02; Rubio-Sandoval et al., 2021)
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