Search results for "Computation"

Computation and Display of 3D Movie From a Single Integral Photography

2016

Integral photography is an auto-stereoscopic technique that allows, among other interesting applications, the display of 3D images with full parallax and avoids the painful effects of the accommodation-convergence conflict. Currently, one of the main drawbacks of this technology is the need of a huge amount of data, which have to be stored and transmitted. This is due to the fact that behind every visual resolution unit, i.e. behind any microlens of an integral-photography monitor, between 100 and 300 pixels should appear. In this paper, we make use of an updated version of our algorithm, SPOC 2.0, to alleviate this situation. We propose the application of SPOC 2.0 for the calculation of co…

Varieties of Algebras with Superinvolution of Almost Polynomial Growth

2015

Let A be an associative algebra with superinvolution ∗ over a field of characteristic zero and let $c_{n}^{\ast }(A)$ be its sequence of corresponding ∗-codimensions. In case A is finite dimensional, we prove that such sequence is polynomially bounded if and only if the variety generated by A does not contain three explicitly described algebras with superinvolution. As a consequence we find out that no intermediate growth of the ∗-codimensions between polynomial and exponential is allowed.

Space of signatures as inverse limits of Carnot groups

2021

We formalize the notion of limit of an inverse system of metric spaces with 1-Lipschitz projections having unbounded fibers. The construction is applied to the sequence of free Carnot groups of fixed rank n and increasing step. In this case, the limit space is in correspondence with the space of signatures of rectifiable paths in ℝn, as introduced by Chen. Hambly-Lyons’s result on the uniqueness of signature implies that this space is a geodesic metric tree. As a particular consequence we deduce that every path in ℝn can be approximated by projections of some geodesics in some Carnot group of rank n, giving an evidence that the complexity of sub-Riemannian geodesics increases with the step.

Silhouette encoding and synthesis using elliptic Fourier descriptors, and applications to videoconferencing

2004

Abstract This paper investigates the use of elliptic Fourier descriptors as a shape descriptor for encoding the silhouette of a person. Shape descriptors are here used for predicting the shape of silhouettes in missing frames within a sequence. This prediction scheme is applied to the case of generating in-between images in a low frame rate videoconferencing system, where the reconstructed silhouette is used as a binary mask for reducing the computational time for the frame reconstruction.

Bot or not? a case study on bot recognition from web session logs

2018

This work reports on a study of web usage logs to verify whether it is possible to achieve good recognition rates in the task of distinguishing between human users and automated bots using computational intelligence techniques. Two problem statements are given, offline (for completed sessions) and on-line (for sequences of individual HTTP requests). The former is solved with several standard computational intelligence tools. For the second, a learning version of Wald’s sequential probability ratio test is used.

The vertical spectrum of H2CO revisited: (SC)2-CI and CC calculations

2003

The vertical electronic spectrum of formaldehyde has been studied by means of (SC)2-MR-SDCI and CCLR methods. Two basis sets of atomic natural orbitals (ANOs) complemented with a one-centre series of Rydberg orbitals were used. The first was taken from the CASPT2 study by Merchan, M., and Roos, B. O., 1995, Theoret. Chim. Acta, 92, 221, and may be described as C,O[4s3pld]/H[2slp] with a lslpld Rydberg series centred in the charge centroid of the 2B2 state of the cation. The second was a larger basis set that may be described as C,O[6s5p3d2f]/H[4s3p2d] + 3s3p3d in the same centre. The (SC)2 dressing may be applied efficiently to an MR-SDCI method and comparison with the dressed CAS-SDCI is s…

Book Review: Structure and Reactivity in Reverse Micelles.(Series: Studies in Physical and Theoretical Chemistry, Vol. 65). Edited by M. P. Pileni

1991

Weak aurophilic interactions in a series of Au(III) double salts.

2015

In this work, several new examples of rare AuIII⋯AuIII aurophilic contacts are reported. A series of gold(III) double salts and complexes, viz. [AuX2(L)][AuX4] (L = 2,2′-bipyridyl, X = Cl 1, Br 2; L = 2,2′-bipyrimidine, X = Cl 3, Br 4; L = 2,2′-dipyridylamine, X = Cl 5, Br 6), [AuX3(biq)] (biq = 2,2′-biquinoline, X = Cl 7, Br 8), [LH][AuX4] (L = 2,2′-bipyridyl, X = Cl 9; L = 2,2′-bipyrimidine, X = Cl 12; L = 2,2′-dipyridylamine, X = Cl 14, Br 15; L = 2,2′-biquinoline, X = Cl 17, Br 18), [AuBr2(bpy)]2[AuBr4][AuBr2] 10, [AuCl2(bpm)][AuCl2] 11, (bpmH)2[AuBr4][AuBr2] 13, and (dpaH)[AuBr2] 16 (1, 2, and 7 were reported earlier) was synthesized by coordination of a particular ligand to the AuIII …

Building a medical research cloud in the EASI-CLOUDS project

2015

Summary The demand for Information Technology (IT) resources is constantly growing in the scientific area. The ability to store and process increasing amounts of data has transformed many research disciplines like the life sciences, which now rely on complex data processing and data analytics. Cloud computing can provide researchers with scalable and easy-to-use hardware and software resources and allows on-demand access to services, tools, or even complete work environments. The European research project EASI-CLOUDS has developed a service delivery platform with special regard to service integration, monitoring and management, and the negotiation of service level agreements. In order to de…

Through a Glass, Darkly

2013

Political actors increasingly use the microblogging service, Twitter, for the organization, coordination, and documentation of collective action. These interactions with Twitter leave digital artifacts that can be analyzed. In this article, we look at Twitter messages commenting on one of the most contentious protests in Germany’s recent history, the protests against the infrastructure project Stuttgart 21. We analyze all messages containing the hashtag #s21 that were posted between May 25, 2010, and November 14, 2010, by the 80,000 most followed Twitter users in Germany. We do this to answer three questions: First, what distinguishes events that resulted in high activity on Twitter from ev…