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

Privacy-preserving Anti-Money Laundering using Secure Multi-Party Computation

Money laundering is a serious financial crime where criminals aim to conceal the illegal source of their money via a series of transactions. Although banks have an obligation to monitor transactions, it is difficult to track these illicit money flows since they typically span over multiple banks, which cannot share this information due to privacy concerns. We present secure risk propagation, a novel efficient algorithm for money laundering detection across banks without violating privacy concerns. In this algorithm, each account is assigned a risk score, which is then propagated through the transaction network. In this article we present two results. Firstly, using data from a large Dutch bank, we show that it is possible to detect unusual activity using this model, with cash ratio as the risk score. With a recall of 20%, the precision improves from 15% to 40% by propagating the risk scores, reducing the number of false positives significantly. Secondly, we present a privacy-preserving solution for securely performing risk propagation over a joint, inter-bank transaction network. To achieve this, we use Secure Multi-Party Computation (MPC) techniques, which are particularly well-suited for the risk propagation algorithm due to its structural simplicity. We also show that the running time of this secure variant scales linearly in the amount of accounts and transactions. For 200, 000 transactions, two iterations of the secure algorithm between three virtual parties, run within three hours on a consumer-grade server

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.