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MULTIBODY NUMERICAL SIMULATION FOR VEHICLE – PEDESTRIAN CRASH TEST
No full textThe purpose of this paper is the simulation of vehicle – pedestrian crash test, executed by Visual Nastran. The evaluation of the damage caused to pedestrian is obtained following the EURONCAP directive. The vehicle virtual model, DIMA, follows closely the characteristics of a saloon car belonging to the small cars category. A total of 16 simulation tests are conduced; each characterized by different initial conditions. The vehicle advances with several speeds, at constant speed and in braking. The anthropomorphic model Dummy impacts with the vehicle in lateral or perfectly frontal position with respect to the front of the vehicle
DEVELOPMENT OF AN ANTHROPOMORPHIC MODEL FOR VEHICLE – PEDESTRIAN CRASH TEST
No full textThe purpose of this work is the achievement of an anthropomorphic model for the virtual simulation of pedestrian – vehicle crash test. “Dummy” construction in Visual Nastran room does possible the preparation of crash test with several vehicle models. Its three-dimensional geometry is implemented by video animation software, extracting the geometry element for element, and its characteristics are in keeping with EURONCAP protocol. Every bodily segment properties are determined using the reference material on the movement biomechanics. At last fall tests from three different heights are simulated for the “Dummy” validation, obtaining a reliable result
Multibody numerical simulation for vehicle – pedestrian crash test and analysis of characteristic parameters
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An SQL extension supporting user viewpoints
No full textIn order to accomplish independence on the logical data organization, a relational DBMS must be capable of interpreting query language sentences which reference attributes belonging to different relations even if the necessary joins are not explicitly formulated (query inference problem). In this work we propose an SQL extension which supports concise formulation of queries through the dynamic definition of user viewpoints. User viewpoints are perspectives for accessing data; each user viewpoint defines a virtual derived relation (user viewpoint relation) which includes all those in the database scheme, each accessed by means of exactly one chain of system-activated equi-joins. Our approach to the definition of user viewpoint relations aims at reducing the global cost of query formulation, that is, the number of joins which must be explicitly written
Tolerance of increasing water salinity in the red swamp crayfish Procambarus clarkii (Girard, 1852)
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The analysis of rRNA sequence-structure in phylogenetics: An application to the family Pectinidae (Mollusca: Bivalvia)
No full textSeveral studies pointed out the relevance of integrating secondary structure information in sequence analysis and phylogenetics, both in terms of phylogenetic resolution and of marker suitability for phylogenetic reconstruction at higher taxonomic-rank. In this study we explore in a phylogenetic framework the primary and secondary structure information from nuclear (ITS2) and mitochondrial (16S) ribosomal DNA sequences from the Pectinidae, commonly known as scallops. Primary sequences were analysed under neighbour-joining, maximum parsimony, maximum likelihood, and Bayesian approaches. The individual RNA secondary structures were analysed alone and with primary sequences employing a combined model of sequence-structure evolution. The information from primary sequences and secondary structure of the ITS2 are concordant and provide good phylogenetic resolution, while the mitochondrial marker 16S fails to resolve the relationships between the major clades and shows a lack of structural signals. Our phylogenetic reconstruction provided evidence for the monophyly of the subfamily Pectininae and the tribes Aequipectinini and Pectinini while the subfamily Chlamydinae, although recovered in some analyses, did not receive good support. The secondary structure analysis of the derived pectinid ITS2 rRNA sequence revealed three striking differences between Pectininae and Chlamydinae subfamilies: (a) Chlamydinae ITS2 rRNA folding shows the typical four domains architecture, while the one of Pectininae only three; (b) the Pectinidae basal DI pairing shows a different sequence-structure consensus between Pectininae and Chlamydinae; (c) the Pectininae DIII domain holds a specific short secondary stem (Pec STEM). Furthermore, the scallop ITS2 rRNA folding analysis has shown the presence of a conserved sequence motif (invariably located on apical portion of the DIII domain) which emerges as a common feature across Bivalvia. The combined sequence-structure approach employed in this study, corroborates the deep significance of including the secondary structure information in phylogenetic analysis both as combined sequence-structure alignment as well as pointing out conserved elements of the RNA folding
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