1,721,078 research outputs found
Optimization of wheel characteristic angles by numerical simulation, with verify of Pacejka Formulas
No full textCOMPORTAMENTO DINAMICO DI UN AUTOVEICOLO. INFLUENZA DEGLI ANGOLI CARATTERISTICI DELLE RUOTE
No full textOptimization of the characteristic angles of front and rear McPherson suspension on a circular track using multibody numerical simulation
No full textThe research reported in this paper aims to simulate the road holding of a virtual vehicle using multibody simulation to estimate the contact forces between tire and ground and the roll motion when cornering. Furthermore, the effect of the characteristic angles on the variation of the forces of the tire in contact with the ground is studied to determine optimal values for these angles. Emphasis is placed on an average-class vehicle, of which both the external dimensions and mass are chosen appropriately, with a McPherson suspension mounted on both the front and rear. The characteristic values of the camber and toe-in angles, in both the front and the rear, are optimized for motion in the curve under constant traction. The results of numerical simulation are compared with results from the theory of stability in the curve (given the vertical configuration of the vehicle)
Impact of multiple modes on the black-hole superradiant instability
No full textUltralight bosonic fields in the mass range of approximately (10-20-10-11) eV can trigger a superradiant instability that extracts energy and angular momentum from an astrophysical black hole with mass M∼(5,1010)M, forming a nonspherical, rotating condensate around it. So far, most studies of the evolution and end state of the instability have been limited to initial data containing only the fastest growing superradiant mode. By studying the evolution of multimode data in a quasiadiabatic approximation, we show that the dynamics is much richer and depends strongly on the energy of the seed, on the relative amplitude between modes, and on the gravitational coupling. If the seed energy is a few percent of the black-hole mass, a black hole surrounded by a mixture of superradiant and nonsuperradiant modes with comparable amplitudes might not undergo a superradiant unstable phase, depending on the value of the boson mass. If the seed energy is smaller, as in the case of an instability triggered by quantum fluctuations, the effect of nonsuperradiant modes is negligible. We discuss the implications of these findings for current constraints on ultralight fields with electromagnetic and gravitational-wave observations
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
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