Search results for " programmi"

The closure of the numerical range of an operator as spectral set

1964

Eigenvectors of k–ψ-contractive wedge operators

2008

Abstract We present new boundary conditions under which the fixed point index of a strict- ψ -contractive wedge operator is zero. Then we investigate eigenvalues and corresponding eigenvectors of k – ψ -contractive wedge operators.

A pre-processing technique based on the wavelet transform for linear autoassociators with applications to face recognition

1997

In order to improve the performance of a linear autoassociator (which is a neural network model), we explore the use of several preprocessing techniques. The gist of our approach is to store, in addition to the original pattern, one or several pre-processed (i.e. filtered) versions of the patterns to be stored in a neural network. First, we compare the performance of several pre-processing techniques (a plain vanilla version of the autoassociator as a control, a Sobel operator, a Canny-Deriche operator, and a multiscale Canny-Deriche operator) on an example of a pattern completion task using a noise degraded version of a face stored in an autoassociator. We found that the multiscale Canny-D…

Cameras: Forms of Interaction

2010

This essay examines the material design of cameras. The author argues that design plays a central role in the interaction between Operator and Spectator (R. Barthes) and, furthermore, that it entails significant effects on photographic aesthetics. Finally, the author also considers some of the design differences between traditional emulsion cameras and digital cameras.

Communication: Restoring full size extensivity in internally contracted multireference coupled cluster theory.

2012

The reason for the lack of size extensivity in the valence space in current implementations of internally contracted multireference coupled cluster theories is the procedure used to eliminate redundant components from the cluster operator. We present a simple way to restore full size extensivity by performing this critical step in a basis of excitation operators that are normal ordered with respect to the multiconfigurational reference function.

IOWA Operators and Its Application to Image Retrieval

2014

This paper presents a relevance feedback procedure based on logistic regression analysis. Since, the dimension of the feature vector associated to each image is typically larger than the number of evaluated images by the user, different logistic regression models have to be fitted separately. Each fitted model provides us with a relevance probability and a confidence interval for that probability. In order to aggregate these set of probabilities and confidence intervals we use an IOWA operator. The results will show the success of our algorithm and that OWA operators are an efficient and natural way of dealing with this kind of fusion problems.

The Probability Law for Generic Density Operators

2020

In this chapter, the probability law of the non-null eigenstates of a generic density operator—studied in the previous chapter—is determined, by showing that given the composite system and the subsystem being considered, a mapping arises which associates a universal probability distribution to the non-null eigenstates of the generic density operator. We thus recover the Born statistical interpretation without having assumed it as a postulate.

Reflection and Refraction of Singularities for Wave Equations with Interface Conditions given by Fourier Integral Operators

1992

Cauchy problems for hyperbolic operators often have the property, that the singularities of the initial data propagate along the bicharacteristic strips of the operator (cf. e.g. [13]). We consider, in the linear case, the situation where the bicharacteristics hit transversally a spacelike interface, which is ‘active’ in the sense that the interface condition is given via certain Fourier integral operators. Taking the identity, we obtain classical transmission conditions. A suitable functional analytic setting is furnished by the interaction concept [3], [6], [7], which covers very general mutual influences of evolution phenomena on different domains.

Approximation properties of q-Kantorovich-Stancu operator

2015

In this paper we study some properties of Kantorovich-type generalizations of the q-Stancu operators. We obtain some approximation properties for these operators, estimating the rate of convergence by using the first and second modulus of continuity. Also, we investigate the statistical approximation properties of the q-Kantorovich-Stancu operators using the Korovkin-type statistical approximation theorem.

A systematic approach to deriving incremental type checkers

2020

Static typing can guide programmers if feedback is immediate. Therefore, all major IDEs incrementalize type checking in some way. However, prior approaches to incremental type checking are often specialized and hard to transfer to new type systems. In this paper, we propose a systematic approach for deriving incremental type checkers from textbook-style type system specifications. Our approach is based on compiling inference rules to Datalog, a carefully limited logic programming language for which incremental solvers exist. The key contribution of this paper is to discover an encoding of the infinite typing relation as a finite Datalog relation in a way that yields efficient incremental up…