An effectiveness analysis of altmetrics indices for different levels of artificial intelligence publications

Scientometrics - Altmetrics indices are increasingly applied to measure scholarly influence in recent years because they can reflect the influence of research outputs more timely comparing with...     

GPU-accelerated registration of hyperspectral images using KAZE features

The Journal of Supercomputing - Image registration is a common task in remote sensing, consisting in aligning different images of the same scene. In the particular case of hyperspectral images, the...     

Cooperative games with nontransferable utility on antimatroids

This paper introduces a new family of nontransferable utility (NTU) games with partial cooperation. Games with transferable utility (TU) restricted by antimatroids were studied since 2004. Antimatroids are known combinatorial structures which are interpreted in games as dependency situations among a group of agents, and they generalize several other hierarchical structures studied in the literature. Now we define projected NTU games over antimatroids following the same idea. We have needed to build a new theory about projections between two coalitions. In this case, an outcome is feasible for a coalition if and only if its projection is feasible in the NTU game. This paper studies several properties of the projected games and the relations between these games and the original game for some interesting cases: TU games, hyperplane games and bargaining problems.     

Thermal characterization of granular materials using a thermal-wave resonant cavity under the dual-phase lag model of heat conduction

The process of heat transport in granular materials has generated a great deal of controversy. It has been claimed that the process is affected not only by the thermal conductivity, diffusivity and heat capacity, but also additional parameters in the form of time-phase lags must be considered. These quantities permit to take into account the thermal inertia and the micro-structural interactions of the media in such a way that they establish the non-simultaneity between the temperature and the heat flux. A highly successful model that takes into account these effects is known as the dual-phase lag model of heat conduction. It constitutes an approach that generalizes and overcomes the limitations of the classical Fourier law of heat transport. One of the most sensitive techniques for measuring thermal properties is the thermal-wave resonant cavity, which is formed by three layers. The one in the middle is semi solid, liquid or gas, whose thickness can be changed moving one of the external layers. In order to study the material in the middle, a modulated heat source is applied to one of the external layers, and the changes of temperature are registered at the surface of any of the external layers. This methodology has provided high accuracy results for the thermal properties of liquids, gases and nanofluids in the context of Fourier heat diffusion equation. However results for granular materials using this methodology are scarce and the role of the phase lags in heat transport has not been fully explored. In this work, the theoretical basis for the development of a thermal-wave resonant cavity based on dual-phase lag model is studied. It is shown that this system could be used to measure not only the thermal diffusivity but also the time-phase lags of granular materials, by performing a suitable thickness scan of the cavity. It is shown that the results obtained can be a highly useful in the development of experimental methodologies revealing the possibility of non-Fourier heat transport and how the thermal characterization of granular materials can be performed.     

Measuring building façades with a low-cost close-range photogrammetry system

The dimensions of façades and window openings are usually determined by direct measurements using tapes and plummets. These direct methods are time consuming and risky for operators, so indirect approaches are needed. In this paper, we analyse a planar-surface measuring system based on close-range photogrammetry to determine its accuracy and precision. This system is composed of a digital camera and a laser distance meter mounted on a support that allows the laser distance meter to be moved independently of the camera. The proposed system can determine the dimensions of objects. Also, this system provides an estimation of the precision of the calculations for the distances between points. By knowing the uncertainty of their measurements, users can accept or reject the measurement depending on the application tolerance.     

Thermal wave oscillations and thermal relaxation time determination in a hyperbolic heat transport model

One of the major challenges in the study of thermal transport and its analysis, based on the hyperbolic model associated with Cattaneo equation, is the fact that it is necessary to determine the thermal relaxation time for the analyzed materials. This parameter has been an elusive physical quantity to be determined experimentally even though it is of crucial importance in heat transport. In this paper a system formed by a semi-infinite layer in contact with a finite one, that is excited by a modulated heat source is studied. It is shown that a frequency range can be found in which the amplitude and phase of the spatial component of the oscillatory surface temperature show strong oscillations when the thermal relaxation time of the finite layer is close to its thermalization time. When the thermal effusivities of the layers are quite different or their thermal relaxation times are similar, it is shown that simple analytical expressions for the values of the maxima and minima of the oscillations as well as for the frequencies, at which they occur, are obtained. These results were used to establish a methodology to determine the thermal relaxation time as well as additional thermal properties of the finite layer.     

FEM modeling of structures based on close range digital photogrammetry

The aim of this paper is to present a methodology for the evaluation of historic timber structures, based on numerical modeling coupled with on site measurements. A method to measure the geometry of structural elements of a timber roof using a photogrammetric modeling procedure is described. In particular, we show the utility of photogrammetric based models when applied to structural analysis by directly introducing 3D geometry files in the preprocessing module of computational software based on the Finite Element Method. The 2D and 3D FEM models of the roof are considered to compare the simple and more complex modeling, and static and dynamic analyses are performed. Both models are prepared using the photogrammetric data.     

Personal multimedia services over a common home and access networking environment

This article presents a new end-to-end architecture model that will enable the deployment of a plethora of different multimedia services from diverse suppliers competitively coexisting over a common access and home networking environment. The model is focused on personal multimedia communication services and terminals. The proposed model is a segmentation of the end-to-end multimedia chain into several business segments. The interfaces among segments and functional entities inside each segment are identified and defined in the work. In order to study the impact level of the results achieved, a comparison with the approximation to NGN provided by current standardization bodies in the field (3GPP and TISPAN) is also included in the article. This comparison highlights the advantages of using this model as a solution to offer PMC services.     

Automated generation of program translation and verification tools using annotated grammars

Automatically generating program translators from source and target language specifications is a non-trivial problem. In this paper we focus on the problem of automating the process of building translators between operations languages, a family of DSLs used to program satellite operations procedures. We exploit their similarities to semi-automatically build transformation tools between these DSLs. The input to our method is a collection of annotated context-free grammars. To simplify the overall translation process even more, we also propose an intermediate representation common to all operations languages. Finally, we discuss how to enrich our annotated grammars model with more advanced semantic annotations to provide a verification system for the translation process. We validate our approach by semi-automatically deriving translators between some real world operations languages, using the prototype tool which we implemented for that purpose.