Efficient cubic spline interpolation implemented with FIR filters

Classical Cubic spline interpolation needs to solve a set of equations of high dimension. In this work we show how to compute the interpolant using a FIR digital filter, with a reduced number of operations per interpolated point and high accuracy. Additionally, the computation can be made on real time as the signal samples are acquired. Following this approach, we show how to obtain easily the derivatives of the interpolant in a similar way, and also signal approximations to reduce the oscillations that appear when using high order splines. These techniques are very well suited to compute continuous representations of image contours on closed shapes and to find its curvature and singularities.Peer ReviewedPostprint (published version

Effect of heat treatment on top-layer hardness of electromechanically burnished products

22.00; Translated from Polish (Wiad. Hutn. 1987 (1) p. 13-16)Available from British Library Document Supply Centre- DSC:9022.06(BISI-Trans--26757)T / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo

Efficient cubic spline interpolation implemented with FIR filters

Classical Cubic spline interpolation needs to solve a set of equations of high dimension. In this work we show how to compute the interpolant using a FIR digital filter, with a reduced number of operations per interpolated point and high accuracy. Additionally, the computation can be made on real time as the signal samples are acquired. Following this approach, we show how to obtain easily the derivatives of the interpolant in a similar way, and also signal approximations to reduce the oscillations that appear when using high order splines. These techniques are very well suited to compute continuous representations of image contours on closed shapes and to find its curvature and singularities.Peer Reviewe

The formation of Al_2O_3/Al composites by directed oxidation of Al

SIGLEAvailable from British Library Document Supply Centre- DSC:D173875 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Quantitatively scoring behavior from video-recorded, long-lasting fish trajectories

Scoring animal behavior is increasingly needed for better understanding ecological processes. For example, behavior shapes harvesting likelihood, thus management of harvested resources should improve after accounting for behavior-driven processes. Automatic video-recording at controlled arenas is the most widespread method for scoring behavior. However, long term tracking animals while keeping identity is still an opened challenge. Here, we develop an ad-hoc algorithm for multi-tracking objects during days or even weeks, to fulfill the particular needs for a behavioral assay concerning a fish species targeted by recreational fishing. Specifically, we overcome the challenge of keeping fish identity in a context where they often disappeared from the camera when entering a shelter, the pixel size was low compared to the size of the arena and the lighting was constrained by the wellbeing of the fish. This work may contribute to better assess the behavioral features of fish in long-lasting lab conditions

Automated taxon identification of teleost fishes using an otolith online database-AFORO

Automated Taxon Identification (ATI) systems that use a database to identify species or anatomical structures of species from different taxonomical groups have recently been developed. However, few of these works have been applied to marine organisms. In this paper we develop an ATI system for identifying Actynopterigian species from their otolith contour; this is important information for the palaeontological, ictiological and ecological sciences, especially in food web studies. The AFORO website comprises the first web-based automated species identification system based exclusively on otolith shape outline. Species are identified iteratively based on a multiscale representation of the otolith contour. The ATI system is very easy to use as it only requires uploading a suitably oriented otolith image on a black background. Two tests were carried out with a database of 1480 images of left sacullar otoliths (sagittae) from 420 species. The first test analysed 50 different otoliths, 10 per species, from 5 different species. The second test identified 50 otoliths, each from a different species. The two tests obtained similar results (percentage of correct identifications): 72% of specimens were correctly identified at species level, and the percentage increased to 90% at genus level and reached 94% at family level. The best results are obtained for species which have an otolith contour with a very specific morphology, such as the mackerel Scomber colias, and the less efficient results for species with common shaped otoliths with unclear specific characteristics, such as the Mediterranean horse-mackerel Trachurus mediterraneus, or species with large morphological variability between individuals, such as Lophius budegassa or Synodus saurus.Peer Reviewe