RelVAE: Generative Pretraining for few-shot Visual Relationship Detection

Visual relations are complex, multimodal concepts that play an important role in the way humans perceive the world. As a result of their complexity, high-quality, diverse and large scale datasets for visual relations are still absent. In an attempt to overcome this data barrier, we choose to focus on the problem of few-shot Visual Relationship Detection (VRD), a setting that has been so far neglected by the community. In this work we present the first pretraining method for few-shot predicate classification that does not require any annotated relations. We achieve this by introducing a generative model that is able to capture the variation of semantic, visual and spatial information of relations inside a latent space and later exploiting its representations in order to achieve efficient few-shot classification. We construct few-shot training splits and show quantitative experiments on VG200 and VRD datasets where our model outperforms the baselines. Lastly we attempt to interpret the decisions of the model by conducting various qualitative experiments

A community effort in SARS-CoV-2 drug discovery.

peer reviewedThe COVID-19 pandemic continues to pose a substantial threat to human lives and is likely to do so for years to come. Despite the availability of vaccines, searching for efficient small-molecule drugs that are widely available, including in low- and middle-income countries, is an ongoing challenge. In this work, we report the results of an open science community effort, the "Billion molecules against Covid-19 challenge", to identify small-molecule inhibitors against SARS-CoV-2 or relevant human receptors. Participating teams used a wide variety of computational methods to screen a minimum of 1 billion virtual molecules against 6 protein targets. Overall, 31 teams participated, and they suggested a total of 639,024 molecules, which were subsequently ranked to find 'consensus compounds'. The organizing team coordinated with various contract research organizations (CROs) and collaborating institutions to synthesize and test 878 compounds for biological activity against proteases (Nsp5, Nsp3, TMPRSS2), nucleocapsid N, RdRP (only the Nsp12 domain), and (alpha) spike protein S. Overall, 27 compounds with weak inhibition/binding were experimentally identified by binding-, cleavage-, and/or viral suppression assays and are presented here. Open science approaches such as the one presented here contribute to the knowledge base of future drug discovery efforts in finding better SARS-CoV-2 treatments.R-AGR-3826 - COVID19-14715687-CovScreen (01/06/2020 - 31/01/2021) - GLAAB Enric

Nonlinear analysis of speech signals: Generalized dimensions and Lyapunov exponents

In this paper, we explore modern methods and algorithms from fractal/chaotic systems theory for modeling speech signals in a multidimensional phase space and extracting characteristic invariant measures like generalized fractal dimensions and Lyapunov exponents. Such measures can capture valuable information for the characterisation of the multidimensional phase space- which is closer to the true dynamics- since they are sensitive to the frequency with which the attractor visits different regions and the rate of exponential divergence of nearby orbits, respectively. Further we examine the classification capability of related nonlinear features over broad phoneme classes. The results of these preliminary experiments indicate that the information carried by these novel nonlinear feature sets is important and useful. 1

Model-level data-driven sub-units for signs in videos of continuous sign language

We investigate the issue of sign language automatic phonetic subunit modeling, that is completely data driven and without any prior phonetic information. A first step of visual processing leads to simple and effective region-based visual features. Prior to the sub-unit modeling we propose to employ a pronunciation clustering step with respect to each sign. Afterwards, for each sign and pronunciation group we find the time segmentation at the hidden Markov model (HMM) level. The models employed refer to movements as a sequence of dominant hand positions. The constructed segments are exploited explicitly at the model level via hierarchical clustering of HMMs and lead to the data-driven movement sub-unit construction. The constructed movement sub-units are evaluated in qualitative analysis experiments on data from the Boston University (BU)-400 American Sign Language corpus showing promising results. Index Terms — sign language, subunit modeling, HMM 1