Search results for " poster"

The CCSD(T) model with Cholesky decomposition of orbital energy denominators

2010

A new implementation of the coupled cluster singles and doubles with approximate triples correction method [CCSD(T)] using Cholesky decomposition of the orbital energy denominators is described. The new algorithm reduces the scaling of CCSD(T) from N-7 to N-6, where N is the number of orbitals. The Cholesky decomposition is carried out using simple analytical expressions that allow us to evaluate a priori the order in which the decomposition should be carried out and to obtain the relevant parts of the vectors whenever needed in the calculation. Several benchmarks have been carried out comparing the performance of the conventional and Cholesky CCSD(T) implementations. The Cholesky implement…

Boghossian's Reductio of Compatibilism

1998

Según Boghossian, la compatibilidad entre el externismo respecto del contenido y el autoconocimiento implica el absurdo según el cual es posible conocer a priori verdades substantivas sobre el mundo, como que existe agua. El argumento de Boghossian descansa crucialmente en dos supuestos: en primer lugar, que el carácter composicional o atómico son propiedades internas de los conceptos; en segundo lugar, que el externalismo no puede dar cuenta de conceptos atómicos con extensión vacía. Ambos supuestos se ponen en cuestión en este artículo. Por una parte, el externismo puede concebir plausiblemente el carácter composicional o atómico de los conceptos como dependiente de la naturaleza real de …

Absence of muscarinic modulation of vasopressin release from the isolated rat neurohypophysis

1975

1. Isolated rat neurohypophyses were incubated in Locke solution at 37°C and the vasopressin output into the medium determined by bioassay. 2. Potassium chloride 60 mM caused a 9-fold increase in the rate of vasopressin release that was abolished when calcium chloride was omitted from the Locke solution. 3. Acetylcholine 5.5×10−4 M neither alone nor in the presence of atropine 2.9×10−6 M changed the “resting” release of vasopressin. 4. Neither acetylcholine 5.5×10−4 M nor oxotremorine 10−4 and 3×10−4 M altered the vasopressin release evoked by potassium chloride 60 mM. 5. In contrast to the peripheral adrenergic nerve fibres, the secretory terminal fibres of the neurohypophysis do not appea…

Fully reliable a posteriori error control for evolutionary problems

2015

Upper Bound for the Approximation Error for the Kirchhoff-Love Arch Problem

2013

In this paper, a guaranteed and computable upper bound of approximation errors for the Kirchhoff-Love arch problem is derived. In general, it belongs to the class of functional a posteriori error estimates. The derivation method uses purely functional arguments and, therefore, the estimates are valid for any conforming approximation within the energy space. The computational implementation of the upper bound is discussed and demonstrated by a numerical example.

Guaranteed error bounds and local indicators for adaptive solvers using stabilised space–time IgA approximations to parabolic problems

2019

Abstract The paper is concerned with space–time IgA approximations to parabolic initial–boundary value problems. We deduce guaranteed and fully computable error bounds adapted to special features of such type of approximations and investigate their efficiency. The derivation of error estimates is based on the analysis of the corresponding integral identity and exploits purely functional arguments in the maximal parabolic regularity setting. The estimates are valid for any approximation from the admissible (energy) class and do not contain mesh-dependent constants. They provide computable and fully guaranteed error bounds for the norms arising in stabilised space–time approximations. Further…

Neural networks with non-uniform embedding and explicit validation phase to assess Granger causality

2015

A challenging problem when studying a dynamical system is to find the interdependencies among its individual components. Several algorithms have been proposed to detect directed dynamical influences between time series. Two of the most used approaches are a model-free one (transfer entropy) and a model-based one (Granger causality). Several pitfalls are related to the presence or absence of assumptions in modeling the relevant features of the data. We tried to overcome those pitfalls using a neural network approach in which a model is built without any a priori assumptions. In this sense this method can be seen as a bridge between model-free and model-based approaches. The experiments perfo…

Artificial organisms as tools for the development of psychological theory: Tolman's lesson

2007

In the 1930s and 1940s, Edward Tolman developed a psychological theory of spatial orientation in rats and humans. He expressed his theory as an automaton (the ‘‘schematic sowbug’’) or what today we would call an ‘‘artificial organism.’’ With the technology of the day, he could not implement his model. Nonetheless, he used it to develop empirical predictions which tested with animals in the laboratory. This way of proceeding was in line with scientific practice dating back to Galileo. The way psychologists use artificial organisms in their work today breaks with this tradition. Modern ‘‘artificial organisms’’ are constructed a posteriori, working from experimental or ethological observations…

A Posteriori Error Bounds for Approximations of the Oseen Problem and Applications to the Uzawa Iteration Algorithm

2014

Abstract. We derive computable bounds of deviations from the exact solution of the stationary Oseen problem. They are applied to approximations generated by the Uzawa iteration method. Also, we derive an advanced form of the estimate, which takes into account approximation errors arising due to discretization of the boundary value problem, generated by the main step of the Uzawa method. Numerical tests confirm our theoretical results and show practical applicability of the estimates.

Perceptual adaptive insensitivity for support vector machine image coding.

2005

Support vector machine (SVM) learning has been recently proposed for image compression in the frequency domain using a constant epsilon-insensitivity zone by Robinson and Kecman. However, according to the statistical properties of natural images and the properties of human perception, a constant insensitivity makes sense in the spatial domain but it is certainly not a good option in a frequency domain. In fact, in their approach, they made a fixed low-pass assumption as the number of discrete cosine transform (DCT) coefficients to be used in the training was limited. This paper extends the work of Robinson and Kecman by proposing the use of adaptive insensitivity SVMs [2] for image coding u…