Search results for "Model theory"
showing 10 items of 681 documents
Normalizability, Synchronicity, and Relative Exactness for Vector Fields in C2
2004
In this paper, we study the necessary and su.cient condition under which an orbitally normalizable vector field of saddle or saddle-node type in C2 is analytically conjugate to its formal normal form (i.e., normalizable) by a transformation fixing the leaves of the foliation locally. First, we express this condition in terms of the relative exactness of a certain 1-form derived from comparing the time-form of the vector field with the time-form of the normal form. Then we show that this condition is equivalent to a synchronicity condition: the vanishing of the integral of this 1-form along certain asymptotic cycles de.ned by the vector field. This can be seen as a generalization of the clas…
A posteriori error estimates for a Maxwell type problem
2009
In this paper, we discuss a posteriori estimates for the Maxwell type boundary-value problem. The estimates are derived by transformations of integral identities that define the generalized solution and are valid for any conforming approximation of the exact solution. It is proved analytically and confirmed numerically that the estimates indeed provide a computable and guaranteed bound of approximation errors. Also, it is shown that the estimates imply robust error indicators that represent the distribution of local (inter-element) errors measured in terms of different norms. peerReviewed
Approximation of plurisubharmonic functions
2015
We extend a result by Fornaaess and Wiegerinck [Ark. Mat. 1989;27:257-272] on plurisubharmonic Mergelyan type approximation to domains with boundaries locally given by graphs of continuous functions.
Some common fixed point results for weakly compatible mappings in cone metric type space
2013
In this paper we consider cone metric type spaces which are introduced as a generalization of symmetric and metric spaces by Khamsi and Hussain in 2010. Then we prove several common fixed point for weakly compatible mappings in cone metric type spaces. All results are proved in the settings of a solid cone, without the assumption of continuity of the mappings.
Effect of Prime Type on Lexical Decision Time
1987
The present investigation concerns the issues of the control condition and type of related prime-target relationship operationalization in the lexical-decision paradigm. It is shown that the use of a row of asterisks produces strong inhibitory effects on reaction time to the target relative to a control condition formed with the word “neutro” (“neutral”). The operationalization of prime-target relatedness by means of association of category norms seems equally adequate, although category exemplars do not prime category exemplar targets. Both sets of data are discussed in relation to current research trends using lexical-decision time.
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.
A survey on solvable sesquilinear forms
2018
The aim of this paper is to present a unified theory of many Kato type representation theorems in terms of solvable forms on a Hilbert space \((H,\langle\cdot,\cdot\rangle)\) In particular, for some sesquilinear forms Ω on a dense domain \(D\subseteq\mathcal {H}\) one looks for a representation \(\Omega(\xi,\eta)= \langle T\xi,\eta\rangle\) \((\xi\epsilon\mathcal{D}\mathcal(T),\eta\epsilon D)\) where T is a densely defined closed operator with domain \(D(\mathcal{T})\subseteq \mathcal{D}\). There are two characteristic aspects of a solvable form on H. One is that the domain of the form can be turned into a reexive Banach space that need not be a Hilbert space. The second one is that represe…
Experimental realization of a new type of crystalline undulator.
2014
A new scheme of making crystalline undulators was recently proposed and investigated theoretically by Andriy Kostyuk, concluding that a new type of crystalline undulator would be not only viable, but better than the previous scheme. This article describes the first experimental measurement of such a crystalline undulator, produced by using Si(1-x)Ge(x)-graded composition and measured at the Mainzer Microtron facility at beam energies of 600 and 855 MeV. We also present theoretical models developed to compare with the experimental data.
Existence for shape optimization problems in arbitrary dimension
2002
We discuss some existence results for optimal design problems governed by second order elliptic equations with the homogeneous Neumann boundary conditions or with the interior transmission conditions. We show that our continuity hypotheses for the unknown boundaries yield the compactness of the associated characteristic functions, which, in turn, guarantees convergence of any minimizing sequences for the first problem. In the second case, weaker assumptions of measurability type are shown to be sufficient for the existence of the optimal material distribution. We impose no restriction on the dimension of the underlying Euclidean space.
Study on difficulties and misconceptions with modern type systems
2014
Functional programming is often presented as an advantageous programming paradigm by its advocates, but many students and teachers consider it to be hard to learn. One particular hurdle in learning functional programming is mastering the modern type systems employed in these languages. In this article, we identify student difficulties with means of multiple choice questions embedded into the on-line materials of an introductory functional programming course. The most prevalent misconceptions were confusing with parametric polymorphism with subtyping, the assigning too much meaning to variables names, and confounding general language patterns with special cases.