Looking Deeper into Deep Learning Model: Attribution-based Explanations of TextCNN

Layer-wise Relevance Propagation (LRP) and saliency maps have been recently used to explain the predictions of Deep Learning models, specifically in the domain of text classification. Given different attribution-based explanations to highlight relevant words for a predicted class label, experiments based on word deleting perturbation is a common evaluation method. This word removal approach, however, disregards any linguistic dependencies that may exist between words or phrases in a sentence, which could semantically guide a classifier to a particular prediction. In this paper, we present a feature-based evaluation framework for comparing the two attribution methods on customer reviews (public data sets) and Customer Due Diligence (CDD) extracted reports (corporate data set). Instead of removing words based on the relevance score, we investigate perturbations based on embedded features removal from intermediate layers of Convolutional Neural Networks. Our experimental study is carried out on embedded-word, embedded-document, and embedded-ngrams explanations. Using the proposed framework, we provide a visualization tool to assist analysts in reasoning toward the model's final prediction.Comment: NIPS 2018 Workshop on Challenges and Opportunities for AI in Financial Services: the Impact of Fairness, Explainability, Accuracy, and Privacy, Montr\'eal, Canad

Catalytic combustion of propane in a membrane reactor with separate feed of reactants. II: Operation in presence of trans-membrane pressure gradients

This is the second communication of a series dealing with an experimental and modelling study on propane catalytic combustion in a membrane reactor with separate feed of reactants. In paper I the behaviour of the reactor in the absence of trans-membrane pressure gradients was presented and discussed. Attention is here focused on the reactor behaviour when pressure differences are applied over the membrane, resulting in a convective flow through the membrane itself. By these means, a major conversion enhancement (up to more than 300%) is achievable compared to the case in which only diffusive mass transfer controls the reactor performance. However, above certain pressure differences (> 1 bar), this is obtained at the price of noticeable slip of unconverted reactants across the membrane. The experimental results are in good agreement with the predictions of an isothermal model based on the numerical solution of differential mass balances across the membrane, employing a Stefan-Maxwell expression for diffusive fluxes and a d'Arcy law for convective one

[Entrevista al sacerdote don Cirilo Tormo, por su nombramiento de hijo adoptivo de Alcoy]

El acto tuvo lugar el día 22 de junio de 1977 en un salón abarrotado de público como homenaje a toda la obra realizada por el sacerdot

A Catalytically Active Membrane Reactor for Fast, Highly Exothermic, Heterogeneous Gas Reactions. A Pilot Plant Study

Membrane reactors have been frequently studied because of their ability to combine chemical activity and separation properties into one device. Due to their thermal stability and mechanical strength, ceramic membranes are preferred over polymeric ones, but small transmembrane fluxes obstruct a widespread industrial use of a membrane reactor. Consequently, a bench-scale membrane reactor with a tubular, macroporous membrane (dp = 700 nm) was developed in order to attain increased fluxes. A cooling pipe was concentrically placed inside the tubular membrane to remove heat from the membrane surface, so the present membrane reactor was suitable to conduct exothermic reactions. As a model reaction, the heterogeneous oxidation of carbon monoxide over platinum, with separated feed of carbon monoxide and oxygen, was performed in the present setup. First, the present membrane reactor was characterized by the determination of the transport parameters, structure parameters of the membrane, and the external transfer coefficients. Subsequently fluxes of the reactants and products were measured over a wide range of process conditions. Especially the influence of a transmembrane pressure difference was studied extensively. Furthermore overall conversion of carbon monoxide was measured under various process conditions, and the results were compared with the simulations of a simplified, overall reactor model. From the results of the present investigation, it could be concluded that the application of a pressure difference over the membrane turned out to be a major process control parameter. It increases the product yield and preferentially directs the fluxes toward one side of the membrane. It was shown that even for macroporous catalytic membranes substantial pressure differences are allowed without any slip of unconverted reactants through the membrane. Furthermore, high degrees of conversion were observed in the present setup, and the simulations of the overall reactor model were in reasonable agreement with the experimental data. The overall model contained no adjustable parameters. From this study, the catalytically active, ceramic membrane reactor with separated feed of reactants turned out to be highly flexible and easy to control.

Compositional and abundance changes of nitrogen-cycling genes in plant-root microbiomes along a salt marsh chronosequence

Disentangling the relative influences of soil properties and plant-host on root-associated microbiomes in natural systems is challenging, given that spatially segregated soil types display distinct historical legacies. In addition, distant locations may also lead to biogeographical patterns of microbial communities. Here, we used an undisturbed salt marsh chronosequence spanning over a century of ecosystem development to investigate changes in the community composition and abundance of a set of nitrogen-cycling genes. Specifically, we targeted genes of diazotrophs and ammonia oxidizers associated with the bulk and rhizosphere soil of the plant species Limonium vulgare. Samples were collected across five distinct successional stages of the chronosequence (ranging from 5 to 105 years) at two time-points. Our results indicate that soil variables such as sand:silt:clay % content and pH strongly relates to the abundance of N-cycling genes in the bulk soil. However, in the rhizosphere samples, the abundance of ammonia-oxidizing organisms (both bacteria and archaea, AOB and AOA, respectively) was relatively constant across most of the successional stages, albeit displaying seasonal variation. This result indicates a potentially stronger control of plant host (rather than soil) on the abundance of these organisms. Interestingly, the plant host did not have a significant effect on the composition of AOA and AOB communities, being mostly divergent according to soil successional stages. The abundance of diazotrophic communities in rhizosphere samples was more affected by seasonality than those of bulk soil. Moreover, the abundance pattern of diazotrophs in the rhizosphere related to the systematic increase of plant biomass and soil organic matter along the successional gradient. These results suggest a potential season-dependent regulation of diazotrophs exerted by the plant host. Overall, this study contributes to a better understanding of how the natural formation of a soil and host plants influence the compositional and abundance changes of nitrogen-cycling genes in bulk and rhizosphere soil microhabitats