scholarly journals Approximation and Shape Preserving Properties of the Bernstein Operator of Max-Product Kind

2009 ◽  
Vol 2009 ◽  
pp. 1-26 ◽  
Author(s):  
Barnabás Bede ◽  
Lucian Coroianu ◽  
Sorin G. Gal
Keyword(s):  
Nonlinear Operator ◽  
Approximation Error ◽  
Approximation Order ◽  
Order Of Approximation ◽  
Shape Preserving ◽  
Explicit Constant ◽  
Open Question ◽  
Shape Preserving Properties ◽  
Upper Estimate ◽  
Better Than

Starting from the study of theShepard nonlinear operator of max-prod typeby Bede et al. (2006, 2008), in the book by Gal (2008), Open Problem 5.5.4, pages 324–326, theBernstein max-prod-type operatoris introduced and the question of the approximation order by this operator is raised. In recent paper, Bede and Gal by using a very complicated method to this open question an answer is given by obtaining an upper estimate of the approximation error of the form (with an unexplicit absolute constant ) and the question of improving the order of approximation is raised. The first aim of this note is to obtain this order of approximation but by a simpler method, which in addition presents, at least, two advantages: it produces an explicit constant in front of and it can easily be extended to other max-prod operators of Bernstein type. However, for subclasses of functions including, for example, that of concave functions, we find the order of approximation , which for many functions is essentially better than the order of approximation obtained by the linear Bernstein operators. Finally, some shape-preserving properties are obtained.

scholarly journals Approximation and shape preserving properties of the nonlinear Favardsza-Szász-Mirakjan operator of max-product kind

Filomat ◽  
2010 ◽  
Vol 24 (3) ◽  
pp. 55-72 ◽  
Author(s):  
Barnabás Bede ◽  
Lucian Coroianu ◽  
Sorin Gal
Keyword(s):  
Nonlinear Operator ◽  
Approximation Error ◽  
Pointwise Estimate ◽  
Approximation Order ◽  
Order Of Approximation ◽  
Bernstein Type ◽  
Shape Preserving ◽  
Explicit Constant ◽  
Open Question ◽  
Shape Preserving Properties

Starting from the study of the Shepard nonlinear operator of max-prod type in [6], [7], in the book [8], Open Problem 5.5.4, pp. 324-326, the Favard-Sz?sz-Mirakjan max-prod type operator is introduced and the question of the approximation order by this operator is raised. In the recent paper [1], by using a pretty complicated method to this open question an answer is given by obtaining an upper pointwise estimate of the approximation error of the form C?1(f;?x/?n) (with an unexplicit absolute constant C>0) and the question of improving the order of approximation ?1(f;?x/?n) is raised. The first aim of this note is to obtain the same order of approximation but by a simpler method, which in addition presents, at least, two advantages : it produces an explicit constant in front of ?1(f;?x/?n) and it can easily be extended to other max-prod operators of Bernstein type. Also, we prove by a counterexample that in some sense, in general this type of order of approximation with respect to ?1(f;?) cannot be improved. However, for some subclasses of functions, including for example the bounded, nondecreasing concave functions, the essentially better order ?1 (f;1/n) is obtained. Finally, some shape preserving properties are obtained.

scholarly journals A Family of 6-Point n-Ary Interpolating Subdivision Schemes

2018 ◽  
Vol 37 (4) ◽  
pp. 481-490
Author(s):  
Robina Bashir ◽  
Ghulam Mustafa
Keyword(s):  
Divided Difference ◽  
Interpolation Property ◽  
Approximation Order ◽  
Visual Performance ◽  
Shape Preserving ◽  
Computer Aided ◽  
Specific Position ◽  
Step Algorithm ◽  
Shape Preserving Properties ◽  
Geometric Designs

We derive three-step algorithm based on divided difference to generate a class of 6-point n-ary interpolating sub-division schemes. In this technique second order divided differences have been calculated at specific position and used to insert new vertices. Interpolating sub-division schemes are more attractive than approximating schemes in computer aided geometric designs because of their interpolation property. Polynomial generation and polynomial reproduction are attractive properties of sub-division schemes. Shape preserving properties are also significant tool in sub-division schemes. Further, some significant properties of ternary and quaternary sub-division schemes have been elaborated such as continuity, degree of polynomial generation, polynomial reproduction and approximation order. Furthermore, shape preserving property that is monotonicity is also derived. Moreover, the visual performance of proposed schemes has also been demonstrated through several examples.

scholarly journals Transformed Structural Properties Method to Determine the Controllability and Observability of Robots

2021 ◽  
Vol 11 (7) ◽  
pp. 3082
Author(s):  
Dany Ivan Martinez ◽  
José de Jesús Rubio ◽  
Victor Garcia ◽  
Tomas Miguel Vargas ◽  
Marco Antonio Islas ◽  
...  
Keyword(s):  
Structural Properties ◽  
Approximation Error ◽  
Linearization Method ◽  
Controllability And Observability ◽  
Better Than

Many investigations use a linearization method, and others use a structural properties method to determine the controllability and observability of robots. In this study, we propose a transformed structural properties method to determine the controllability and observability of robots, which is the combination of the linearization and the structural properties methods. The proposed method uses a transformation in the robot model to obtain a linear robot model with the gravity terms and uses the linearization of the gravity terms to obtain the linear robot model; this linear robot model is used to determine controllability and observability. The described combination evades the structural conditions requirement and decreases the approximation error. The proposed method is better than previous methods because the proposed method can obtain more precise controllability and observability results. The modified structural properties method is compared with the linearization method to determine the controllability and observability of three robots.

Lower Bounds on OBDD Proofs with Several Orders

2021 ◽  
Vol 22 (4) ◽  
pp. 1-30
Author(s):  
Sam Buss ◽  
Dmitry Itsykson ◽  
Alexander Knop ◽  
Artur Riazanov ◽  
Dmitry Sokolov
Keyword(s):  
Lower Bound ◽  
Lower Bounds ◽  
Communication Complexity ◽  
Multiparty Communication ◽  
Constant Degree ◽  
Polynomial Size ◽  
Explicit Constant ◽  
Open Question ◽  
System 1 ◽  
Exponential Size

This article is motivated by seeking lower bounds on OBDD(∧, w, r) refutations, namely, OBDD refutations that allow weakening and arbitrary reorderings. We first work with 1 - NBP ∧ refutations based on read-once nondeterministic branching programs. These generalize OBDD(∧, r) refutations. There are polynomial size 1 - NBP(∧) refutations of the pigeonhole principle, hence 1-NBP(∧) is strictly stronger than OBDD}(∧, r). There are also formulas that have polynomial size tree-like resolution refutations but require exponential size 1-NBP(∧) refutations. As a corollary, OBDD}(∧, r) does not simulate tree-like resolution, answering a previously open question. The system 1-NBP(∧, ∃) uses projection inferences instead of weakening. 1-NBP(∧, ∃ k is the system restricted to projection on at most k distinct variables. We construct explicit constant degree graphs G n on n vertices and an ε > 0, such that 1-NBP(∧, ∃ ε n ) refutations of the Tseitin formula for G n require exponential size. Second, we study the proof system OBDD}(∧, w, r ℓ ), which allows ℓ different variable orders in a refutation. We prove an exponential lower bound on the complexity of tree-like OBDD(∧, w, r ℓ ) refutations for ℓ = ε log n , where n is the number of variables and ε > 0 is a constant. The lower bound is based on multiparty communication complexity.

scholarly journals Do sound symbolism effects for written words relate to individual phonemes or to phoneme features?

2019 ◽  
Vol 11 (02) ◽  
pp. 235-255 ◽  
Author(s):  
PADRAIC MONAGHAN ◽  
MATTHEW FLETCHER
Keyword(s):  
Sound Symbolism ◽  
Acoustic Properties ◽  
Morphological Properties ◽  
Phonological Features ◽  
Written Form ◽  
Open Question ◽  
Semantic Attributes ◽  
Better Than

abstractThe sound of words has been shown to relate to the meaning that the words denote, an effect that extends beyond morphological properties of the word. Studies of these sound-symbolic relations have described this iconicity in terms of individual phonemes, or alternatively due to acoustic properties (expressed in phonological features) relating to meaning. In this study, we investigated whether individual phonemes or phoneme features best accounted for iconicity effects. We tested 92 participants’ judgements about the appropriateness of 320 nonwords presented in written form, relating to 8 different semantic attributes. For all 8 attributes, individual phonemes fitted participants’ responses better than general phoneme features. These results challenge claims that sound-symbolic effects for visually presented words can access broad, cross-modal associations between sound and meaning, instead the results indicate the operation of individual phoneme to meaning relations. Whether similar effects are found for nonwords presented auditorially remains an open question.

scholarly journals On the Numerical Solution of Fractional Boundary Value Problems by a Spline Quasi-Interpolant Operator

Axioms ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 61
Author(s):  
Francesca Pitolli
Keyword(s):  
Fractional Derivative ◽  
Boundary Value Problems ◽  
Numerical Experiments ◽  
Boundary Value ◽  
Bernstein Operator ◽  
Explicit Formulas ◽  
Shape Preserving ◽  
Engineering Control ◽  
Shape Preserving Properties ◽  
Fractional Boundary Value Problems

Boundary value problems having fractional derivative in space are used in several fields, like biology, mechanical engineering, control theory, just to cite a few. In this paper we present a new numerical method for the solution of boundary value problems having Caputo derivative in space. We approximate the solution by the Schoenberg-Bernstein operator, which is a spline positive operator having shape-preserving properties. The unknown coefficients of the approximating operator are determined by a collocation method whose collocation matrices can be constructed efficiently by explicit formulas. The numerical experiments we conducted show that the proposed method is efficient and accurate.

Voronovskaja’s theorem, shape preserving properties and iterations for complex q-Bernstein polynomials

2011 ◽  
Vol 48 (1) ◽  
pp. 23-43 ◽  
Author(s):  
Sorin Gal
Keyword(s):  
Convergence Theorem ◽  
Analytic Functions ◽  
Quantitative Estimate ◽  
Bernstein Polynomials ◽  
Exact Order ◽  
Approximation Properties ◽  
Shape Preserving ◽  
Voronovskaja’S Theorem ◽  
Shape Preserving Properties ◽  
Compact Disks

In this paper, first we prove Voronovskaja’s convergence theorem for complex q-Bernstein polynomials, 0 < q < 1, attached to analytic functions in compact disks in ℂ centered at origin, with quantitative estimate of this convergence. As an application, we obtain the exact order in approximation of analytic functions by the complex q-Bernstein polynomials on compact disks. Finally, we study the approximation properties of their iterates for any q > 0 and we prove that the complex qn-Bernstein polynomials with 0 < qn < 1 and qn → 1, preserve in the unit disk (beginning with an index) the starlikeness, convexity and spiral-likeness.

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