Spectral and localization properties of random bipartite graphs

Bipartite graphs are often found to represent the connectivity between the components of many systems such as ecosystems. A bipartite graph is a set of n nodes that is decomposed into two disjoint subsets, having m and n-m vertices each, such that there are no adjacent vertices within the same set. The connectivity between both sets, which is the relevant quantity in terms of connections, can be quantified by a parameter a ¿ [0, 1] that equals the ratio of existent adjacent pairs over the total number of possible adjacent pairs. Here, we study the spectral and localization properties of such random bipartite graphs. Specifically, within a Random Matrix Theory (RMT) approach, we identify a scaling parameter ¿ = ¿(n, m, a) that fixes the localization properties of the eigenvectors of the adjacency matrices of random bipartite graphs. We also show that, when ¿ 10) the eigenvectors are localized (extended), whereas the localization–to–delocalization transition occurs in the interval 1/10 < ¿ < 10. Finally, given the potential applications of our findings, we round off the study by demonstrating that for fixed ¿, the spectral properties of our graph model are also universal

Numerical Implementation of a Critical State Model for Soft Rocks

This paper details the basic tasks for the numerical implementation of a simple elasto-plastic critical state model for bonded materials (i.e. soft rocks-hard soils) into the finite element program SNAC developed at the University of Newcastle in Australia. The first task described focusses on the derivation of the incremental constitutive relationships used to represent the mechanical response of a bonded/cemented material under saturated conditions. The second task presents how these stress-strain relations can be numerically integrated using an explicit substepping scheme with automatic error control. The third task concentrates on the verification of the substepping algorithm proposed. The model used to represent the saturated mechanical response of a bonded material combines the modified Cam clay with the constitutive relationships for cemented materials proposed in Gens &amp; Nova (1993), but incorporates some flexibility on the degradation law adopted. The role of suction and other relevant aspects of unsaturated behaviour are also discussed at the end of the paper

Olfactory fMRI Connectivity Analysis Based on Granger Causality with Application in Anosmia Assessment

In this work, we describe hubs organization within the olfactory network with Functional Magnetic Resonance Imaging (fMRI). Granger causality analyses were applied in the supposed regions of interest (ROIs) involved in olfactory tasks, as described in [1]. We aim to get deeper knowledge about the hierarchy of the regions within the olfactory network and to describe which of these regions, in terms of strength of the connectivity, impair in different types of anosmia

Disparate connectivity for structural and functional networks is revealed when physical location of the connected nodes is considered

Macroscopic brain networks have been widely described with the manifold of metrics available using graph theory. However, most analyses do not incorporate information about the physical position of network nodes. Here, we provide a multimodal macroscopic network characterization while considering the physical positions of nodes. To do so, we examined anatomical and functional macroscopic brain networks in a sample of twenty healthy subjects. Anatomical networks are obtained with a graph based tractography algorithm from diffusion-weighted magnetic resonance images (DW-MRI). Anatomical con- nections identified via DW-MRI provided probabilistic constraints for determining the connectedness of 90 dif- ferent brain areas. Functional networks are derived from temporal linear correlations between blood-oxygenation level-dependent signals derived from the same brain areas. Rentian Scaling analysis, a technique adapted from very- large-scale integration circuits analyses, shows that func- tional networks are more random and less optimized than the anatomical networks. We also provide a new metric that allows quantifying the global connectivity arrange- ments for both structural and functional networks. While the functional networks show a higher contribution of inter-hemispheric connections, the anatomical networks highest connections are identified in a dorsal?ventral arrangement. These results indicate that anatomical and functional networks present different connectivity organi- zations that can only be identified when the physical locations of the nodes are included in the analysis

Changes in anatomical and functional connectivity related to lower hippocampal volume

Anatomical 3D T1 weighted images have been widely used to assess the volume of subcortical structures. It has been demonstrated that volume loss of hippocampi, entorhinal cortex and amygdala are early biomarkers for the diagnosis of cognitive impairments and AD1. In this work, we investigate AD biomarkers based on brain connectivity. SC-FC differences have been reported between controls and patients at risk for AD2. We will try to anticipate to MCI or AD diagnoses by differentiating in a sample of healthy subjects, i.e. with no cognitive impairment, other than related to ageing, using as criterion of separation the normalized hippocampal volume (NHV). The sample is formed by volunteers in the Valleca?s Initiative, a longitudinal study evaluating normal ageing in a cohort of more than 600 healthy elder people (70-85 years). The prevalence of AD in people older than 65 years is 13%3 suggesting that a certain number of those subjects will develop AD in the next years. The subjects with lower NHV are more prone to have AD than subjects with higher NHV. Thus they are more likely to manifest connectivity patterns that can be considered as AD biomarkers

Anatomo-functional organization in brain networks

There are several studies focused on comparing rsFC networks with their structural substrate \cite{hagmann2008, honey2010}. However an accurate description of how anatomo-­functional connections are organized, both at physical and topological levels, is still to be defined. Here we present an approach to quantify the anatomo-functional organization and discuss its consistency

Simulación de un concentrador solar de disco parabólico para producción de potencia y enfriamiento

CIES2020 - XVII Congresso Ibérico e XIII Congresso Ibero-americano de Energia SolarRESUMEN: En este trabajo se presenta la modelación y simulación de un concentrador solar de disco parabólico para alimentar térmicamente a un sistema de refrigeración por absorción y a un motor Stirling, con diferente eficiencia, acoplado con un sistema de refrigeración por compresión. El enfriamiento producido por este sistema se utiliza para aire acondicionado de una vivienda. El estudio fue realizado mediante balances de energía y de masa, en cada componente de los sistemas de refrigeración y del sistema solar. La transferencia de calor por convección y por radiación también fueron considerados. Los resultados muestran que el colector solar alcanza eficiencia térmica de hasta 0.82 para relación de concentración de 100. El concentrador solar produce hasta 1.3 kW. En tanto que el sistema completo puede producir enfriamiento de 2.3 kW y 0.47 kW por el sistema de compresión y el de absorción respectivamente. La potencia de la bomba de la disolución es hasta 20 veces menor que la potencia requerida por el compresor del sistema de compresión.ABSTRACT: This paper presents the dish solar collector modeling and simulation for thermally driving an absorption refrigeration system and a Stirling engine, with different efficiency, coupled with a compression refrigeration system. The cooling produced by the system is used for home air conditioning. The study by means energy and mass balances, in each component of the cooling systems and the solar system was carried out. The Convection and radiation heat transfer also has been considered. The results show that the solar collector reaches thermal efficiency of up to 0.82 for a concentration ratio of 100. The solar concentrator produces up to 1.3 kW. While the complete system 2.3 kW and 0.47 kW of cooling by the compression and absorption system respectively can produce. The power of the solution pump is up to 20 times less than the power required by the compressor of the compression system.info:eu-repo/semantics/publishedVersio

Towards sustainable industrial development - a systems thinking-based approach

Various critical global issues, including global warming and poverty, have been recognized and identified by the United Nations (UN) as drivers for unsustainability. Consequently, the UN established the Sustainable Development Goals (SDGs) with the aim of seeking universal peace and larger freedom by balancing the three dimensions of sustainable development, i.e. economic, social and environmental. A particular attention SDGs pay is in eradicating poverty as this is considered one of the greatest global challenges. Poverty is not only an economic matter as it also has an impact on the social and environmental dimensions. A strategy to tackle poverty is to foster industry development. However, a holistic point of view is necessary by also considering stakeholders otherwise, it becomes a neoliberal solution. Despite the fact that some research has been conducted, e.g. case studies and surveys of sustainable practices, there is a lack of industrial sustainable development as a framework to tackle sustainability issues. Thus, this paper proposes a framework for industrial sustainable development under a socially inclusive approach within the context of the Mexican manufacturing industry. The framework proposal is based on a state-of-the-art literature review conducted in the Web of Science and Scopus databases.N/