Higher-Order Aggregate Networks in the Analysis of Temporal Networks: Path structures and centralities

Recent research on temporal networks has highlighted the limitations of a static network perspective for our understanding of complex systems with dynamic topologies. In particular, recent works have shown that i) the specific order in which links occur in real-world temporal networks affects causality structures and thus the evolution of dynamical processes, and ii) higher-order aggregate representations of temporal networks can be used to analytically study the effect of these order correlations on dynamical processes. In this article we analyze the effect of order correlations on path-based centrality measures in real-world temporal networks. Analyzing temporal equivalents of betweenness, closeness and reach centrality in six empirical temporal networks, we first show that an analysis of the commonly used static, time-aggregated representation can give misleading results about the actual importance of nodes. We further study higher-order time-aggregated networks, a recently proposed generalization of the commonly applied static, time-aggregated representation of temporal networks. Here, we particularly define path-based centrality measures based on second-order aggregate networks, empirically validating that node centralities calculated in this way better capture the true temporal centralities of nodes than node centralities calculated based on the commonly used static (first-order) representation. Apart from providing a simple and practical method for the approximation of path-based centralities in temporal networks, our results highlight interesting perspectives for the use of higher-order aggregate networks in the analysis of time-stamped network data.Comment: 27 pages, 13 figures, 3 table

Dry Bulk Tanker Material Sampling Device

The purpose of this project is to provide an easy to manufacture solution to sampling material from dry bulk tankers. A device was developed using basic design requirements. Once a design was created a CAD design was drawn to illustrate and prototype the device. This prototype was placed under rigorous testing to determine effectiveness. The end result provides a dry bulk sampling device for plant workers and/or truck drivers to sample the material in their tankers and send to the laboratory when unloading at a facility

O efeito do ciclo da vida, da descentralização e da dimensão organizacional na adopção do BSC

Mestrado em Contabilidade, Fiscalidade e Finanças EmpresariaisA teoria da contigência defende que o tipo de sistema de controlo de gestão utilizado numa determinada empresa depende das circunstâncias que a envolvem (Otley, 1999). Factores como a descentralização, a dimensão e o estádio do ciclo de vida em que a empresa se encontra afectam o tipo de ferramenta de controlo de gestão utilizado na organização (e.g. Abdel-Kader & Luther, 2008; Hoque & James, 2000; Bruns & Waterhouse, 1975; Miller & Friesen 1984). Este estudo tem como objectivo analisar se empresas de maior dimensão, mais descentralizadas e no estádio maduro do seu ciclo de vida são mais propensas à adopção e utilização do balanced scorecard (BSC). Para esse efeito foram utilizadas 3.518 respostas de um questionário dirigido a administradores, directores financeiros e controllers de empresas portuguesas. Os resultados indicam que organizações maduras, mais descentralizadas e de maior dimensão tendem a adoptar mais o BSC, mas apenas as de maior dimensão (dentro das pequenas e médias empresas) o utilizam frequentemente.Contingence Theory suggests that firms use management control systems according to several factors (Otley, 1999). Some of these factors are decentralization, size, and life cycle stage (e.g. Abdel-Kader & Luther, 2008; Hoque & James, 2000; Bruns & Waterhouse, 1975; Miller & Friesen 1984). This study evaluates whether large firms, more decentralized, and on the maturity stage of the life cycle, are more prone to adopt and use the balanced scorecard (BSC). Using 3.518 responses to a questionnaire sent to executives (CEO, CFO and controllers) of Portuguese companies, the results show that larger, more decentralized and in the maturity stage firms tend to adopt more the BSC, though only larger firms within the Small and Medium Enterprises use the BSC frequently

ParseNet: Looking Wider to See Better

We present a technique for adding global context to deep convolutional networks for semantic segmentation. The approach is simple, using the average feature for a layer to augment the features at each location. In addition, we study several idiosyncrasies of training, significantly increasing the performance of baseline networks (e.g. from FCN). When we add our proposed global feature, and a technique for learning normalization parameters, accuracy increases consistently even over our improved versions of the baselines. Our proposed approach, ParseNet, achieves state-of-the-art performance on SiftFlow and PASCAL-Context with small additional computational cost over baselines, and near current state-of-the-art performance on PASCAL VOC 2012 semantic segmentation with a simple approach. Code is available at https://github.com/weiliu89/caffe/tree/fcn .Comment: ICLR 2016 submissio