196,155 research outputs found
ORIENTATION BEHAVIOR AND HETEROZYGOSITY OF SANDHOPPER POPULATIONS IN RELATION TO STABILITY OF BEACH ENVIRONMENTS
No full textModelling landscape dynamics in a glacial refugium - or the spatial and temporal fluctuations of tree line altitudes
No full textTo produce a dynamic model of tree line position and habitat suitability for temperate and warm temperate forests, with high spatial and temporal resolution from the Last Glacial Maximum to the present, using an approach based on the quasi-constant altitudinal difference between the tree line altitude (TLA) and the equilibrium line altitude (ELA) of glacier
Struttura genetica in popolazioni naturali ed allevate di vongole (Tapes decussatus) in relazione a programmi per la tutela, il ripopolamento, la gestione e la produzione.
No full textGenetic characterization of MHC class II exon2 in Bombina pachypus populations across the entire range: preliminary results”
No full textAn efficient algorithm for exhaustive template matching based on normalized cross correlation
No full textThis work proposes a novel technique aimed at improving the performance of exhaustive template matching based on the normalized cross correlation (NCC). An effective sufficient condition, capable of rapidly pruning those match candidates that could not provide a better cross correlation score with respect to the current best candidate, can be obtained exploiting an upper bound of the NCC function. This upper bound relies on partial evaluation of the crosscorrelation and can be computed efficiently, yielding a significant reduction of operations compared to the NCC function and allows for reducing the overall number of operations required to carry out exhaustive searches. However, the bounded partial correlation (BPC) algorithm turns out to be significantly data dependent. In this paper we propose a novel algorithm that improves the overall performance of BPC thanks to the deployment of a more selective sufficient condition which allows for rendering the algorithm significantly less data dependent. Experimental results with real images and actual CPU time are reported. © 2003 IEEE
Real-time dense stereo on a personal computer
No full textThis paper presents a stereo algorithm that enables real time dense disparity measurements on standard personal computers. Unlike many other dense stereo algorithms, which are based on two matching phases, the proposed algorithm relies on a single matching phase and allows for rejecting unreliable matches by exploiting violations of the uniqueness constraint and analysing the behaviour of the correlation scores. The overall algorithm has been carefully optimised using very efficient calculation schemes and deploying massively the SIMD parallel processing capabilities available nowadays in state-of-the-art general purpose microprocessors. The paper describes the algorithm and the optimisation strategies, and provides experimental results obtained on stereo pairs with ground-truth as well as execution times measurements
Mitochondrial DNA sequence analysis of the spectacled salamander, Salamandrina terdigitata (Urodela: Salamandridae), supports the existence of two distinct species
No full textSalamandrina is a monotypic genus of the family Salamandridae endemic to Italy. Forty five individuals of the spectacled salamander, Salamandrina terdigitata, representing 11 populations throughout the whole distribution range were examined for sequence variation of three mitochondrial DNA genes encoding the 12S and 16S ribosomal RNA's and cytochrome b 1324 bp). The results indicate the existence of two genetically distinct and geographically non- overlapping mtDNA lineages. The first lineage includes the southern populations and the second one comprises the central- northern populations. The degree of genetic divergence between the two groups is high and comparable to distances calculated from homologous sequences available in GenBank between other Salamandrid species. As a result, the genus Salamandrina probably requires splitting into two species. We also compare substitution rates associated with the mitochondrial genes employed across all Salamandrids studied so far, and discuss two possible palaeogeographic scenarios which could have shaped the splitting of the two Salamandrina lineages. These findings have also important implications for management and conservations of the spectacled salamander, which is protected under several international and regional conventions and directives
Leveraging confident points for accurate depth refinement on embedded systems
No full textDespite the notable progress in stereo disparity estimation, algorithms are still prone to errors in challenging conditions. Thus, heuristic disparity refinement techniques are usually deployed to improve accuracy. Moreover, stateof- the-art methods rely on complex CNNs requiring power hungry GPUs not suited for many practical applications constrained by limited computing resources. In this paper, we propose a novel technique for disparity refinement leveraging on confidence measures and a novel, automatic learning-based selection method to discard outliers. Then, a non-local strategy infers missing disparities by analyzing the closest reliable points. This framework is very fast and does not require any hand-tuned thresholding. We assess the performance of our Non-Local Anchoring (NLA), standalone refinement techniques and methods leveraging on confidence measures inside the stereo algorithm. Our evaluation with two popular stereo algorithms shows that our proposal significantly ameliorates their accuracy on Middlebury v3 and KITTI 2015 datasets. Moreover, since our method relies only on cues computed in the disparity domain, it is suited even for COTS stereo cameras coupled with embedded systems, e.g. nVidia Jetson TX2
Divergenza genetica tra popolazioni sudeuropee di Mylabris flexuosa Olivier (Coleoptera, Meloidae).
No full textA PC-based Real-Time Stereo Vision System
No full textThis paper describes a stereo vision system that enables real-time dense depth measurements on a personal computer. The system relies on a very efficient stereo matching engine that, unlike many other approaches which use two distinct matching phases in order to detect unreliable matches, uses a single matching phase. Our matching engine allows for rejecting most unreliable matches by exploiting violations of the uniqueness constraint as well as analysing the behaviour of correlation scores. Real-time capability has been achieved deploying very efficient incremental calculation schemes aimed at avoiding redundant calculations and parallelising the computationally expensive portion of the code with Single Instruction Multiple Data (SIMD) parallel instructions, available nowadays in almost any state-of-the-art general purpose microprocessors. Experimental results on real stereo sequences and preliminary results concerning a 3D people tracking/counting application show the effectiveness of the proposed PC-based stereo vision system for real-time applications
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