99 research outputs found
Visualizing Incongruity: Visual Data Mining Strategies for Modeling Humor in Text
The goal of this project is to investigate the use of visual data mining to model verbal humor. We explored various means of text visualization to identify key featrues of garden path jokes as compared with non jokes. With garden path jokes one interpretation is established in the setup but new information indicating some alternative interpretation triggers some resolution process leading to a new interpretation. For this project we visualize text in three novel ways, assisted by some web mining to build an informal ontology, that allow us to see the differences between garden path jokes and non jokes of similar form. We used the results of the visualizations to build a rule based model which was then compared with models from tradtitional data mining toi show the use of visual data mining. Additional experiments with other forms of incongruity including visualization of âshillingâ or the introduction of false reviews into a product review set. The results are very similar to that of garden path jokes and start to show us there is a shape to incongruity. Overall this project shows as that the proposed methodologies and tools offer a new approach to testing and generating hypotheses related to theories of humor as well as other phenomena involving opposition, incongruities, and shifts in classiïŹcation
Overresolving in the Laplace domain for convolution quadrature methods
Convolution quadrature (CQ) methods have enjoyed tremendous interest in recent years as an efficient tool for solving time-domain wave problems in unbounded domains via boundary integral equation techniques. In this paper we consider CQ type formulations for the parallel space-time evaluation of multistep or stiffly accurate Runge--Kutta rules for the wave equation. In particular, we decouple the number of Laplace domain solves from the number of time steps. This allows us to overresolve in the Laplace domain by computing more Laplace domain solutions than there are time steps. We use techniques from complex approximation theory to analyze the error of the CQ approximation of the underlying time-stepping rule when overresolving in the Laplace domain and show that the performance is intimately linked to the location of the poles of the solution operator. Several examples using boundary integral equation formulations in the Laplace domain are presented to illustrate the main results.
Read More: http://epubs.siam.org/doi/10.1137/16M106474
Product algebras for Galerkin discretisations of boundary integral operators and their applications
Operator products occur naturally in a range of regularised boundary integral equation formulations. However, while a Galerkin discretisation only depends on the domain space and the test (or dual) space of the operator, products require a notion of the range. In the boundary element software package Bempp, we have implemented a complete operator algebra that depends on knowledge of the domain, range, and test space. The aim was to develop a way of working with Galerkin operators in boundary element software that is as close to working with the strong form on paper as possible, while hiding the complexities of Galerkin discretisations. In this article, we demonstrate the implementation of this operator algebra and show, using various Laplace and Helmholtz example problems, how it significantly simplifies the definition and solution of a wide range of typical boundary integral equation problems
On the attenuation coefficient of monomode periodic waveguides
It is widely accepted that, on ensemble average, the transmission T of guided
modes decays exponentially with the waveguide length L due to small
imperfections, leading to the important figure of merit defined as the
attenuation-rate coefficient alpha = -/L. In this letter, we evidence
that the exponential-damping law is not valid in general for periodic monomode
waveguides, especially as the group velocity decreases. This result that
contradicts common beliefs and experimental practices aiming at measuring alpha
is supported by a theoretical study of light transport in the limit of very
small imperfections, and by numerical results obtained for two waveguide
geometries that offer contrasted damping behaviours
Auswirkung von Propofol und Sevofluran auf den SÀure-Basen-Haushalt wÀhrend pÀdiatrischer Herzkatheteruntersuchungen in Intubationsnarkose
Das Propofolinfusionssyndrom (PRIS) ist eine seltene, aber potenziell tödliche Komplikation bei der Anwendung von Propofol. Es ist durch bradykarde Herzrhythmusstörungen mit Ăbergang zur Asystolie in Kombination mit metabolischer Azidose, Rhabdomyolyse von Herz- und Skelettmuskulatur und Nierenversagen charakterisiert und tritt am hĂ€ufigsten bei Langzeitanwendung von Propofol zur Sedierung bei intensivmedizinischer Behandlung auf. Bei Narkosen mit Propofol kommen aber auch Ă€hnliche metabolische VerĂ€nderungen vor, die als VorlĂ€ufer eines PRIS interpretiert werden können. Laktatazidose gilt als FrĂŒhsymptom. Ziel dieser prospektiv randomisierten Studie war der Vergleich der Effekte von Sevofluran- und Propofolnarkose auf den SĂ€ure-Basen-Haushalt wĂ€hrend Herzkatheteruntersuchung bei Kindern. Die Patienten wurden randomisiert einer Propofolgruppe (N = 22) und einer Sevoflurangruppe (N = 20) zugeteilt. Die Auswertung ergab statistisch signifikante, jedoch klinisch wahrscheinlich nicht relevante Unterschiede. Bei Propofolnarkose sanken pH-Wert, Bikarbonat und Basenexzess statistisch signifikant, bei Sevoflurannarkose zeigte sich kein signifikanter Unterschied. Nach der Untersuchung zeigte sich nur bei 55 % der Kinder der Sevoflurangruppe, aber bei 81,8 % der Patienten der Propofolgruppe ein negativer Basenexzess von †-2,5 mmol/l. Ein Basenexzess von †- 5 mmol/l trat nach der Untersuchung bei 15 % der Kinder mit Sevoflurannarkose, aber bei 45,5 % der Kinder mit Propofolnarkose auf. Die Laktatkonzentration im Serum fiel dagegen in beiden Gruppen signifikant ab. Propofol kann im Gegensatz zu Sevofluran bei Anwendung wĂ€hrend pĂ€diatrischen Herzkatheteruntersuchungen eine Verschiebung des SĂ€ure-Basen-Status in Richtung einer metabolische Azidose ohne Laktatazidose induzieren, die möglicherweise bei genetisch prĂ€disponierten Patienten Zeichen eines beginnenden PRIS ist
Product algebras for Galerkin discretisations of boundary integral operators and their applications
Operator products occur naturally in a range of regularized boundary integral equation formulations. However, while a Galerkin discretisation only depends on the domain space and the test (or dual) space of the operator, products require a notion of the range. In the boundary element software package Bempp we have implemented a complete operator algebra that depends on knowledge of the domain, range and test space. The aim was to develop a way of working with Galerkin operators in boundary element software that is as close to working with the strong form on paper as possible while hiding the complexities of Galerkin discretisations. In this paper, we demonstrate the implementation of this operator algebra and show, using various Laplace and Helmholtz example problems, how it significantly simplifies the definition and solution of a wide range of typical boundary integral equation problems
Image-based software solutions for advanced materials processing and characterization
This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this recordNew image-based solutions are being developed for advanced materials processing and characterization, which involve working with and creating high-quality models from scan data (such as MRI, CT, micro-CTâŠ). Techniques involving the reconstruction and analysis of 3D materials data can accurately reconstruct internal structures, even to the nano level, and generate high-quality meshes suitable for design and simulation applications. By looking at key techniques and their applications, it is possible to better understand the wider impact and benefits of image-based modelling for industry when working with advanced materials
Application of the multiple-scattering method to analysis of systems with semi-infinite photonic waveguides
We propose a technique of compensating the spurious reflections implied by
the multiple-scattering (MS) method, commonly used for analyzing finite
photonic crystal (PC) systems, to obtain exact values of characteristic
parameters, such as reflection and transmission coefficients, of PC functional
elements. Rather than a modification of the MS computational algorithm, our
approach involves postprocessing of results obtained by the MS method. We
derive analytical formulas for the fields excited in a finite system, taking
explicitly into account the spurious reflections occurring at the artificial
system boundaries. The intrinsic parameters of the investigated functional
element are found by fitting the results of MS simulations to those obtained
from the formulas derived. Devices linked with one and two semi-infinite
waveguides are analyzed explicitly; possible extensions of the formalism to
more complex circuits are discussed as well. The accuracy of the proposed
method is tested in a number of systems; the results of our calculations prove
to be in good agreement with those obtained independently by other authors.Comment: 8 pages, 5 figure
Compact optical circulator based on a uniformly magnetized ring cavity
International audienceWe propose a new class of compact integrated optical circulators providing a large isolation level while maintaining a straightforward technological feasibility. Their layout is based on a nonreciprocal radial Bragg cavity composed of concentric magneto-optical rings. The circulator ports are standard rib waveguides, butt-coupled to the cavity by cutting through its outer rings. The device is specifically designed for operation in a uniform external magnetic field. Using a coupled-mode description of the complete cavity/waveguide-port system, we explore the rich behaviour of cavity circulators in presence of varying levels of direct port-to-port coupling. We demonstrate numerically a strongly miniaturized two-dimensional cavity circulator, with a total footprint of less than (10λ)2, achieving a 20-dB isolation level at telecom frequencies over a bandwidth of 130 GHz. The device is found to be very tolerant with respect to fabrication imperfections. We finish with an outlook on three-dimensional versions of the proposed nonreciprocal cavities
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