1,720,962 research outputs found
Bitis, binary timed signals processing library
Full text linkBitis is a python module that implements a full set of operators over binary signals represented with BTS format. The BTS format is a computer memory representation of a binary signal that can have a very compact memory footprint when the signal has a low rate of change with respect to its sampling period
Spiral Tessellation on the Sphere
Full text linkIn this paper we describe a tessellation of the
unit sphere in the
3-dimensional space realized using a spiral
joining the north and the south poles. This tiling yields to a
one dimensional labeling of the tiles covering the whole sphere
and to a
1-dimensional natural ordering on the set of tiles of
the tessellation. The correspondence between a point on the
sphere and the tile containing it is derived as an analytical
function, allowing the direct computation of the tile. This
tessellation exhibits some intrinsic features useful for general
applications: absence of singular points and efficient tiles
computation. Moreover, this tessellation can be parametrized
to obtain additional features especially useful for spherical
coordinate indexing: tiles with equal area and good shape
uniformity of tiles. An application to spherical indexing of a
database is presented, it shows an assessment of our spiral tiling
for practical use
Analisi in vivo con elaborazione di immagini 3d della cinematica protesica del ginocchio rilevata con videofluoroscopia
No full textLa crescente diffusione dell'artrosi e dell'intervento di artroplastica sostitutiva del ginocchio richiede lo sviluppo di nuovi strumenti che permettano di migliorare i risultati ottenuti. Partendo da una panoramica di come vengono attualmente affrontati i problemi chirurgici, biologici e meccanici dell'impianto della protesi del ginocchio e quali sono le sue criticità e limitazioni, illustra lo sviluppo e sperimentazione nel mondo di nuovi metodi basati su informazioni derivate dalla cinematica del movimento del ginocchio mediante metodi di elaborazione e model fitting 3d di immagini ottenute con videofluoroscopia
Surface texture measurements of gear tooth
Full text linkThis work presents a study of the surface texture of gear teeth with different surface finish. Surface data have been analyzed by means of traditional roughness parameters and by the harmonic decomposition with FT transform. A method for selecting the significant frequencies of the roughness profile is presented. A comparison of results on gear teeth made by hobbing, grinding and lapping techniques is shown to point out the main effects of each texture finishing on the harmonic analysis
Dynamics modeling of CMM probing systems
Full text linkThe probing system dynamics is important for coordinate measuring machine (CMM) performance, particularly when probing in scanning mode. This is a typical situation e.g. in gear metrology, where the flanks are typically scanned. This may occur even without full awareness of the user, who may accept default values or choose with little understanding. This work presents a modelling of a contouring probe. The model is based on the characteristics of real probes; more specifically, continuous passive systems are considered, resulting essentially in second order 3D systems. The theoretical model is validated experimentally by scanning suitable surfaces exhibiting a range of slopes. The separation between static and dynamic effects is achieved by repeating the experiments at varying scanning speed, so that a same geometrical slope results in different temporal slopes – which the probing system dynamics is sensitive to. The model is oriented to define a good trade-off between the scanning speed and the measurement uncertainty
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
- …
