Relative molecule self-attention transformer

The prediction of molecular properties is a crucial aspect in drug discovery that can save a lot of money and time during the drug design process. The use of machine learning methods to predict molecular properties has become increasingly popular in recent years. Despite advancements in the field, several challenges remain that need to be addressed, like finding an optimal pre-training procedure to improve performance on small datasets, which are common in drug discovery. In our paper, we tackle these problems by introducing Relative Molecule Self-Attention Transformer for molecular representation learning. It is a novel architecture that uses relative self-attention and 3D molecular representation to capture the interactions between atoms and bonds that enrich the backbone model with domain-specific inductive biases. Furthermore, our two-step pretraining procedure allows us to tune only a few hyperparameter values to achieve good performance comparable with state-of-the-art models on a wide selection of downstream tasks

Electromagnetic and Thermal Phenomena Modeling of Electrical Discharges in Liquids

Electrical discharges in liquids have received lots of attention with respect to their potential applications in various techniques and technical processes. Exemplary, they are useful for water treatment, chemical and thermal processes acceleration, or nanoparticles production. In this paper the special utility of discharges for cold pasteurization of fruit juices is presented. Development of devices for its implementation is a significant engineering problem and should be performed using modeling and simulation techniques to determine the real parameters of discharges. Unfortunately, there is a lack of clear and uniform description of breakdown phenomena in liquids. To overcome this limitation, new methods and algorithms for streamers propagation and breakdown phase analysis are presented in the paper. All solutions were tested in “active area” in the form of liquid material model, placed between two flat electrodes. Electromagnetic and thermal-coupled field analysis were performed to determine all the factors that affect the discharge propagation. Additionally, some circuit models were used to include the power source cooperation with discharge region. In general, presented solutions can be defined as universal and one can use them for numerical simulation of other types of discharges

Fast and stable interval bounds propagation for training verifiably robust models

We present an efficient technique to train classificationnetworks which are verifiably robust against norm-bounded adversarialattacks. This framework is built upon interval bounds propagation (IBP),which applies the interval arithmetic to bound the activations at each layerand keeps the prediction invariant to the input perturbation. To speed upand stabilize training of IBP, we supply its cost function with an additionalterm, which encourages the model to keep the interval bounds at hiddenlayers small. Experimental results demonstrate that the training of ourmodel is faster, more stable and less sensitive to the exact specification ofthe training process than original IBP

Adversarial examples detection and analysis with layer-wise autoencoders

We present a mechanism for detecting adversarial examples based on data representations taken from the hidden layers of the target network. For this purpose, we train individual autoencoders at intermediate layers of the target network. This allows us to describe the manifold of true data and, in consequence, decide whether a given example has the same characteristics as true data. It also gives us insight into the behavior of adversarial examples and their flow through the layers of a deep neural network. Experimental results show that our method outperforms the state of the art in supervised and unsupervised settings

Dynamika dystrybucji współautorów

W niniejszym artykule, na podstawie bazy artykułów naukowych, opisano ilościowy efekt wzrostu współpracy uczonych, która objawia się zmianami cech rozkładu liczby współautorów artykułu w czasie. Rozkład liczby współautorów artykułu dostępnego w bazie danych zmienia się w czasie z maksimum dla jednego autora do maksimum kilku autorów. Do wyjaśnienia dynamiki zmian rozkładu liczby współautorów zaproponowano model dylematu społecznego. Spośród trzech została wybrana jedna strategia współpracy odnosząca największe sukcesy.In the present paper, the case of a database of scientific articles is described. There can be observed the quantitative effects of the increasing strength of cooperation between scholars. It is manifested in time-related features changes of the numbers distribution of a single co-authors’ article. The distribution of the number of co-authors of an article recorded in the database evolves with time from a profile with no more than one author to a profile with several authors. A social dilemma model is proposed to explain the dynamics of changes in the distribution of the number of co-authors. The most successful strategy of the three considered alternative strategies of cooperation is selected

Współpraca jako rezultat mutacji i dziedziczenia w grach typu PD/PG

Podejście w grach ewolucyjnych, takich jak Dylemat więźnia, jest oparte przede wszystkim na spójnej strategii. W prezentowanym artykule zaproponowane zostało podejście, w którym współpraca dwóch więźniów może wynikać z mutacji oraz dziedziczenia. System ten ma charakter dylematu społecznego, w którym możliwe jest ustawienie przez każdego z agentów pożądanej dla niego liczby uczestników gry. Ponadto zostały zdefiniowane dwa podstawowe mechanizmy: wahania, które w wyniku mutacji prowadzi do współpracy, a także doboru naturalnego, który ma tendencję do promowania oszustów, w związku z czym zakłóca proces współpracy. W symulacjach numerycznych zostało wykazane, że wzajemne oddziaływanie między dwoma mechanizmami prowadzi do równowagi, a niecelowe strategie są konieczne do nawiązania i utrzymania współpracy między agentami. Tak więc, zaczynając od populacji nie współpracujących agentów, w wyniku procesu ewolucji, może skończyć się na populacji złożonej ze współpracujących grup ze średniej wielkości grupami określonymi przez stopień wahania oraz funkcję spłacającą. Artykuł dokładnie wyjaśnia wyniki numerycznych testów.The approach of evolutionary games like prisoner’s dilemma, among others, is based on a consistent strategy. We propose an experimentally verified system where cooperation can arise out of two simple factors: mutation and inheritance. This system has a social dilemma property and allows each agent to set its own desired number of participants. There are two essential mechanisms: fluctuation through which mutation leads to cooperation, and natural selection which tends to promote cheaters and therefore disrupts the cooperation. It is shown in numerical simulations that the interplay between both mechanisms leads to an equilibrium and that no intentional strategies are necessary to establish and sustain cooperation. Thus, starting from a population of non-cooperating agents, natural evolution can end with a population composed of cooperating groups with the mean group size determined by the fluctuation rate and the pay-off function. A thorough analytical explanation of numerical results is provided

Water diffusion in polymer coatings containing water-trapping particles : Part 2 : Experimental verification of the mathematical model

The influence of the water microtraps (cross-linked poly(methacrylic acid) sodium salt spherical particles) with high sorption capacity and low diffusion coefficient on the water penetration through the epoxy coating has been investigated. Water diffusion coefficients for the pure epoxy coating as well as composite coatings with 5% and 3.7% content of water traps have been estimated by attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) and microbalance measurement methods. Experimental results were compared with the mathematical model of diffusion in composite media. The presence of the particles capable of binding water reversibly (water traps) significantly slows down the diffusion rate. Composites with water traps dispersed in the whole volume of the coating and sandwich-structured coatings composed of 3 layers with particles located only inside the middle layer have been examined. The diffusion rate has been found to depend not only on the concentration of the water traps but also on the location of the particles inside the coating. Both kinds of composites exhibit lower diffusion coefficient in comparison with the pure coating, however in the case of the sandwich-structured composites this effect is significantly stronger and much closer to that predicted by the model. Water diffusion coefficient for the sandwich-structured composite with 5% addition of water traps is ca. three times lower than for the pure epoxy coating