2,963 research outputs found
Local cardinal interpolation by C^2 cubic B2-splines with a tunable shape parameter
No full textA cubic local interpolating B2-spline, controllable by a shape parameter, is introduced and its properties analyzed.
An algorithm for the automatic selection of the free parameter is developed and tested on several examples.
Finally, a two-phase subdivision scheme for its efficient evaluation at dyadic points is presented
Lucia Amalia Scatozza Höricht, I vetri romani di Ercolano ; Lucia Amalia Scatozza Höricht, I monili di Ercolano
No full textBalty Jean-Charles. Lucia Amalia Scatozza Höricht, I vetri romani di Ercolano ; Lucia Amalia Scatozza Höricht, I monili di Ercolano. In: L'antiquité classique, Tome 62, 1993. pp. 576-577
Creating a bridge between cardinal Br-spline fundamental functions for interpolation and subdivision
No full textThis paper presents innovative contributions to the fields of cardinal spline interpolation and subdivision. In particular, it unifies cardinal Br-spline fundamental functions for interpolation that are made of r = M^{L +1} (L ∈ N ∪ { 0 } ) distinct pieces between each pair of interpolation nodes and are featured by the properties of C^{2M−2} smoothness, approximation order 2M and support width 2M(r+1)/r, with the basic limit functions of a special class of non-stationary subdivision schemes of arity M. After introducing a general result, we focus our attention on the subclass of fourth-order accurate, C^2 smooth Br-splines with maximum width of the compact support 6. The binary subdivision scheme yielding these fundamental functions outperforms the existing interpolatory schemes and seems to be the most adequate starting point to obtain compactly supported fundamental (spline) functions for local interpolation over quadrilateral and triangular meshes
Interpolating m-refinable functions with compact support: The second generation class
No full textWe present an algorithm for the construction of a new class of compactly supported interpolating refinable functions that we call the second generation class since, contrary to the existing class, is associated to subdivision schemes with an even-symmetric mask that does not contain the submask 0...,0,1,0,...0. As application examples of the proposed algorithm we present interpolating 4-refinable functions that are generated by parameter-dependent, even-symmetric quaternary schemes never considered in the literature so far
Lucia Pirzio Biroli Stefanelli (Éd.), L'Oro dei Romani. Gioielli di età imperiale
No full textBalty Jean-Charles. Lucia Pirzio Biroli Stefanelli (Éd.), L'Oro dei Romani. Gioielli di età imperiale. In: L'antiquité classique, Tome 63, 1994. p. 643
Lucia Pirzio Biroli Stefanelli (Éd.), L'Oro dei Romani. Gioielli di età imperiale
No full textBalty Jean-Charles. Lucia Pirzio Biroli Stefanelli (Éd.), L'Oro dei Romani. Gioielli di età imperiale. In: L'antiquité classique, Tome 63, 1994. p. 643
Algebraic-Trigonometric Pythagorean-Hodograph space curves
No full textWe introduce a new class of Pythagorean-Hodograph (PH) space curves - called Algebraic-Trigonometric Pythagorean-Hodograph (ATPH) space curves - that are defined over a six-dimensional space mixing algebraic and trigonometric polynomials. After providing a general definition for this new class of curves, their quaternion representation is introduced and the fundamental properties are discussed. Then, as previously done with their quintic polynomial counterpart, a constructive approach to solve the first-order Hermite interpolation problem in R3is provided. Comparisons with the polynomial case are illustrated to point out the greater flexibility of ATPH curves with respect to polynomial PH curves
Construction and Evaluation of Pythagorean Hodograph Curves in Exponential-Polynomial Spaces
No full textIn the past few decades polynomial curves with Pythagorean hodograph (PH curves) have received considerable attention due to their usefulness in various CAD/CAM areas, manufacturing, numerical control machining, and robotics. This work deals with classes of PH curves built upon exponential-polynomial spaces (EPH curves). In particular, for the two most frequently encountered exponential-polynomial spaces, we first provide necessary and sufficient conditions to be satisfied by the control polygon of the Bézier-like curve in order to fulfill the PH property. Then, for such EPH curves, fundamental characteristics like parametric speed or arc length are discussed to show the interesting analogies with their well-known polynomial counterparts. Differences and advantages with respect to ordinary PH curves become commendable when discussing the solutions to application problems like the interpolation of first-order Hermite data. Finally, a new evaluation algorithm for EPH curves is proposed and shown to compare favorably with the celebrated de Casteljau--like algorithm and two recently proposed methods: Woźny and Chudy's algorithm and the dynamic evaluation procedure by Yang and Hong
MDDS (Mixed Directional Difference-Summation) package
No full textThis is a supplement to the paper
[1] G. Casciola, E. Franchini, L. Romani, The mixed directional differencesummation algorithm for generating the B ́ezier net of a trivariate four-direction Box-spline, Numerical Algorithms 43 (2006), pp. 75-9
Aggiornamenti in tema di manumissiones nei testamenti romani d’Egitto prima di Severo Alessandro
No full textDiscussione delle nuove implicazioni storico-giuridiche che emergono dalla rilettura di testamenti di cittadini romani in cui si menzionano manomissioni di schiavi
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