This paper presents a novel modeling technique and develops an interactive algorithm that facilitates the automatic determination of non-uniform knot vectors as well as other control variables for NURBS curves and surfaces through the unified methodology of energy minimization, variational principle, and numerical techniques. NURBS have become a de facto industry-standard primarily because of t...

Digitalization of agriculture bring controllable industrial production and computer-aided design ideas into agriculture, NURBS curves and surfaces is described freedom of widely popular technology, CAD systems are widely used. Method can be easily applied to generate curves, surfaces with NURBS. In this paper, we have developed model of cotton organs using NURBS surface, present a introduction ...

Non-uniform rational B-splines (NURBS) have become a de facto standard in commercial modeling systems because of their power to represent both free-form shapes and some common analytic shapes. To date, however, NURBS have been viewed as purely geometric primitives, which require the designer to interactively adjust many degrees of freedom (DOFs )-control points and associated weights-to achieve...

An interaction integral method for evaluating mixed-mode stress intensity factors (SIFs) for two dimensional crack problems using NURBS-based isogeometric analysis method is investigated. The interaction integral method is based on the path independent J-integral. By introducing a known auxiliary field solution, the mixed-mode SIFs are calculated simultaneously. Among features of B-spline basis...

We develop a dynamic, free-form surface model which is useful for representing a broad class of objects with symmetries and topological variability. The new model is based upon swung NURBS surfaces, and it inherits their desirable cross-sectional design properties. It melds these geometric features with the demonstrated conveniences of surface design within a physics-based framework. We demonst...

Generating valid tool path curves in NURBS form is important in realizing an efficient NURBS machining. In this paper, a method for computing one-sided offset approximations of freeform curves with NURBS format as tool paths is presented. The approach first uses line segments to approximate the progenitor curve with one-sided deviations. Based on the obtained line approximating curve and its of...

Non-rigid image registration is an interesting and challenging research work in medical image processing, computer vision and remote sensing fields. In order to increase the registration accuracy, this paper designs a composite registration algorithm of a rigid transform and free form deformation. Because NURBS (Non-uniform Rational B Spline) with a non-uniform grid has a higher registration pr...

This paper is motivated by the representation of the test functions in Isogeometric Analysis (IgA). IgA is a numerical method that uses the NURBS-based representation of a CAD model to generate the finite-dimensional space of test functions which is used for the simulation. More precisely, the test functions are obtained by composing the inverse of the geometry mapping with the NURBS basis func...

Resumen—Este artículo presenta un método para ajustar objetos 3D con par ches NURBS (B­Splines Racionales No Unifor mes), los cuales son optimizados mediante una Estr ategia Evolutiva Abstract—This article presents a method to fit 3D objects with patches NURBS (Non Un iform Rational B­Splines), which ar e optimized by means of Evolutionary Strategies (ES), which they determine the weights of th...

This paper proposes an off-line feedrate scheduling method of CNC machines constrained by chord tolerance, acceleration and jerk limitations. The off-line process for curve scanning and feedrate scheduling is realized as a pre-processor, which releases the computational burden in real-time task. The proposed method first scans a non-uniform rational B-spline (NURBS) curve and finds out the cruc...