29 research outputs found
Hierarchically branched diffusion models for efficient and interpretable multi-class conditional generation
Diffusion models have achieved justifiable popularity by attaining
state-of-the-art performance in generating realistic objects, including when
conditioning generation on labels. Current diffusion models are universally
linear in nature, modeling diffusion identically for objects of all classes.
For the multi-class conditional generation problem, we propose a novel,
structurally unique framework of diffusion models which are hierarchically
branched according to the inherent relationships between classes. In this work,
we showcase several advantages of branched diffusion models. We demonstrate
that branched models generate samples more efficiently, and are more easily
extended to novel classes in a continual-learning setting. We also show that
branched models enjoy a unique interpretability that offers insight into the
modeled data distribution. Branched diffusion models represent an alternative
paradigm to their traditional linear counterparts, and can have large impacts
in how we use diffusion models for efficient generation, online learning, and
scientific discovery
Complex Preferences for Different Convergent Priors in Discrete Graph Diffusion
Diffusion models have achieved state-of-the-art performance in generating
many different kinds of data, including images, text, and videos. Despite their
success, there has been limited research on how the underlying diffusion
process and the final convergent prior can affect generative performance; this
research has also been limited to continuous data types and a score-based
diffusion framework. To fill this gap, we explore how different discrete
diffusion kernels (which converge to different prior distributions) affect the
performance of diffusion models for graphs. To this end, we developed a novel
formulation of a family of discrete diffusion kernels which are easily
adjustable to converge to different Bernoulli priors, and we study the effect
of these different kernels on generative performance. We show that the quality
of generated graphs is sensitive to the prior used, and that the optimal choice
cannot be explained by obvious statistics or metrics, which challenges the
intuitions which previous works have suggested
A 3D-Shape Similarity-based Contrastive Approach to Molecular Representation Learning
Molecular shape and geometry dictate key biophysical recognition processes,
yet many graph neural networks disregard 3D information for molecular property
prediction. Here, we propose a new contrastive-learning procedure for graph
neural networks, Molecular Contrastive Learning from Shape Similarity
(MolCLaSS), that implicitly learns a three-dimensional representation. Rather
than directly encoding or targeting three-dimensional poses, MolCLaSS matches a
similarity objective based on Gaussian overlays to learn a meaningful
representation of molecular shape. We demonstrate how this framework naturally
captures key aspects of three-dimensionality that two-dimensional
representations cannot and provides an inductive framework for scaffold
hopping
Image-based Social Sensing: Combining AI and the Crowd to Mine Policy-Adherence Indicators from Twitter
Social Media provides a trove of information that, if aggregated and analysed
appropriately can provide important statistical indicators to policy makers. In
some situations these indicators are not available through other mechanisms.
For example, given the ongoing COVID-19 outbreak, it is essential for
governments to have access to reliable data on policy-adherence with regards to
mask wearing, social distancing, and other hard-to-measure quantities. In this
paper we investigate whether it is possible to obtain such data by aggregating
information from images posted to social media. The paper presents VisualCit, a
pipeline for image-based social sensing combining recent advances in image
recognition technology with geocoding and crowdsourcing techniques. Our aim is
to discover in which countries, and to what extent, people are following
COVID-19 related policy directives. We compared the results with the indicators
produced within the CovidDataHub behavior tracker initiative. Preliminary
results shows that social media images can produce reliable indicators for
policy makers.Comment: 10 pages, 9 figures, to be published in Proceedings of ICSE Software
Engineering in Society, May 202
Oltre il Segno/OltreMare
La realizzazione di un volume contenente le incisioni scelte all’interno della Scuola di Grafica d’Arte dell’Accademia di Belle Arti di Palermo, coordinata dai Proff. Giovanni D’Alessandro e Riccardo Mazzarino rappresenta motivo di orgoglio e di soddisfazione per la nostra Istituzione che costruisce i percorsi didattici dei propri corsi a partire dall’esperienza laboratoriale. L’incisione grafica è tra le tecniche artistiche più antiche ma nel contempo più contemporanee. La gestualità intrinseca al segno, che si manifesta nella carta, svela universi della visione inaspettati.(Mario Zito - Direttore dell’Accademia di Belle Arti di Palermo)
Il segno è il risultato di un gesto a volte deciso, a volte contorto, a volte leggero, i cui risultati spesso sono inattesi e sorprendenti. Il volume contiene esemplari di incisioni fortemente caratterizzanti della scuola di Grafica d’Arte che vanta all’interno del proprio corso di studi docenti-artisti che consapevoli della ricchezza del loro bagaglio esperienziale offrono agli studenti gli strumenti necessari per far sì che l’arte del saper fare artigianale, si trasformi in mera poetica artistica