In this paper we address the Phase Retrieval problem, which aims to recover the phase of the Fourier transform of a signal when only magnitude measurements are available. Following recent developments in Phase Retriev...
详细信息
In this paper we address the Phase Retrieval problem, which aims to recover the phase of the Fourier transform of a signal when only magnitude measurements are available. Following recent developments in Phase Retrieval, the problem can be transformed into a convex semidefinite programming optimization problem, which can be solved using Matrix Completion techniques. In this paper the acquisition process is modeled using a likelihood function, which splits the original problem into two convex optimization problems, and alternates between the solution of each of them. To relate both convex problems we introduce a heuristic, which results in fast convergence of the proposed method.
Brain activity can be seen as a time series, in particular, electroencephalogram (EEG) can measure it over a specific time period. In this regard, brain fingerprinting can be subjected to be learned by machine learnin...
详细信息
Diffraction of pulsed electromagnetic (EM) waves in a slot excited Fabry Perót type resonator antenna is studied analytically in the modiÀed Kirchhoff approximation. Closed-form space-time expressions for th...
详细信息
This paper introduces a new paradigm in the electromagnetic (EM) analysis of largely inhomogeneous nanostructures. It is shown that the high degree of inhomogeneity may render the traditional discretisation of such to...
详细信息
This paper introduces a new paradigm in the electromagnetic (EM) analysis of largely inhomogeneous nanostructures. It is shown that the high degree of inhomogeneity may render the traditional discretisation of such topologies problematic. A new discretisation scheme that is much better matched to these topologies is proposed. The scheme involves a more adequate meshing and discretisation formalism, in conjunction with an original combination of dual space-time EM field quantities to be calculated. The pivotal field equations are elaborately discussed, with an emphasis on their computational implications.
A parallel distributed approach to refine a mesh while preserving the curvature of a target geometry is presented. Our approach starts by generating a coarse linear mesh of the computational domain. Second, the former...
详细信息
A parallel distributed approach to refine a mesh while preserving the curvature of a target geometry is presented. Our approach starts by generating a coarse linear mesh of the computational domain. Second, the former coarse mesh is curved to match the curvature of the target geometry. Then, the curved mesh is partitioned and the subdomain meshes are sent to the slaves. Finally, the curved elements are uniformly subdivided in parallel targeting the geometry approximated by the curved mesh. The result is a distributed finer linear mesh featuring improved geometric accuracy. The key ingredient of our implementation is to approximate the target geometry as a linear mesh equipped with an elemental field corresponding to an element-wise polynomial geometry representation. Thus, the distribution of the curved geometry is equivalent to partitioning the linear mesh and sending the subdomain meshes and the elemental fields to the slaves. The main application of the obtained finer linear mesh is to compute in parallel steady state flow solutions on real topographies. The qualitative results show that for 2D and 3D steady state flow solutions, on real and synthetic topographies, our parallel subdivision approach mitigates the artificial artifacts that might appear with standard straight-sided subdivision methods. We also check the parallel performance of the implementation by performing a weak scalability test in 2D.
Diffraction of pulsed electromagnetic (EM) waves in a slot excited Fabry Perot type resonator antenna is studied analytically in the modified Kirchhoff approximation. Closed-form space-time expressions for the radiate...
ISBN:
(纸本)9781785618154;9781785618161
Diffraction of pulsed electromagnetic (EM) waves in a slot excited Fabry Perot type resonator antenna is studied analytically in the modified Kirchhoff approximation. Closed-form space-time expressions for the radiated EM fields are found using the Cagniard-DeHoop technique. Illustrative numerical examples are given.
Apache Spark is commonly used as a big data analytical platform on powerful computer clusters, as it primarily employ the main computer memory for the evaluation. Our attempt adds self-organizing map software librarie...
详细信息
Apache Spark is commonly used as a big data analytical platform on powerful computer clusters, as it primarily employ the main computer memory for the evaluation. Our attempt adds self-organizing map software libraries onto a single big data analytical stack and is efficient and fast enough even on a standard single computer. This innovative approach brings the big data analysis to researchers with limited resources. Our genuine idea was experimentally confirmed and is described here. As a case study for our method we we used the available #Brexit data and the sentiment analysis of corresponding tweets and the correlation with the stock exchange data.
We present a robust and automatic method to generate an idealized surface geometry of a city landscape ready to be meshed for computer simulations. The city geometry is idealized for non viscous flow simulations and t...
详细信息
We present a robust and automatic method to generate an idealized surface geometry of a city landscape ready to be meshed for computer simulations. The city geometry is idealized for non viscous flow simulations and targets two main geometrical features: the topography and the city blocks. The procedure is fully automatic and demands no human interaction given the following source data: the city cadastre, a Digital Elevation Model (DEM) of all the target domain, and Light Detection And Ranging (LiDAR) data of the domain region covered by the cadastre. The geometry representation takes three main steps. First, a 2D mesh of the cadastre is generated, where the elements are marked according to street and block regions. Second, using a DEM of the city landscape the topography surface mesh is generated by finding the best surface mesh in the least-squares sense obtained by deforming the previous 2D mesh. Third, we extrude the block facades and we compute a planar ceiling taking into account all the buildings belonging to that city block. We describe the applicability of the geometry representation by presenting the work-flow required to generate an unstructured mesh valid for non-viscous flow or transport simulations. Finally, we illustrate the main application by obtaining a surface and tetrahedral mesh for the city of Barcelona in Spain.
As Mobile Learning (M-Learning) has had a great impact on online education, more and more mobile applications are designed and developed for the M-Learning. In this paper, a novel mobile-optimized application architec...
详细信息
Biological brains can learn, recognize, organize, and re-generate large repertoires of temporal patterns. Here I propose a mechanism of neurodynamical pattern learning and representation, called conceptors, which offe...
详细信息
Biological brains can learn, recognize, organize, and re-generate large repertoires of temporal patterns. Here I propose a mechanism of neurodynamical pattern learning and representation, called conceptors, which offers an integrated account of a number of such phenomena and functionalities. It becomes possible to store a large number of temporal patterns in a single recurrent neural network. In the recall process, stored patterns can be morphed and "focussed". Parametric families of patterns can be learnt from a very small number of examples. Stored temporal patterns can be content-addressed in ways that are analog to recalling static patterns in Hopfield networks.
暂无评论