Safety-Aware Apprenticeship Learning

Apprenticeship learning (AL) is a kind of Learning from Demonstration techniques where the reward function of a Markov Decision Process (MDP) is unknown to the learning agent and the agent has to derive a good policy by observing an expert's demonstrations. In this paper, we study the problem of how to make AL algorithms inherently safe while still meeting its learning objective. We consider a setting where the unknown reward function is assumed to be a linear combination of a set of state features, and the safety property is specified in Probabilistic Computation Tree Logic (PCTL). By embedding probabilistic model checking inside AL, we propose a novel counterexample-guided approach that can ensure safety while retaining performance of the learnt policy. We demonstrate the effectiveness of our approach on several challenging AL scenarios where safety is essential.Comment: Accepted by International Conference on Computer Aided Verification (CAV) 201

Probabilistic Guarantees for Safe Deep Reinforcement Learning

Deep reinforcement learning has been successfully applied to many control tasks, but the application of such agents in safety-critical scenarios has been limited due to safety concerns. Rigorous testing of these controllers is challenging, particularly when they operate in probabilistic environments due to, for example, hardware faults or noisy sensors. We propose MOSAIC, an algorithm for measuring the safety of deep reinforcement learning agents in stochastic settings. Our approach is based on the iterative construction of a formal abstraction of a controller's execution in an environment, and leverages probabilistic model checking of Markov decision processes to produce probabilistic guarantees on safe behaviour over a finite time horizon. It produces bounds on the probability of safe operation of the controller for different initial configurations and identifies regions where correct behaviour can be guaranteed. We implement and evaluate our approach on agents trained for several benchmark control problems

Plaster Layout Process in Civil Works with a Focus on Clean Production

The constant expansion of civil construction and the increasing use of plaster gives rise to a solid waste generation problem causing difficulties for the disposal or reuse of this material. The generation of plaster waste represents an economic problem, with serious consequences and impacts. In order to contribute to sustainability, this study sought to evaluate the reduction of plaster waste in an apartment construction project, employing the layout method. With the adequate arrangement of plates, a reduction of 4.41% in the use of plaster could be obtained, This reduction will consequently result in the minimization of waste from civil works, bringing invaluable economic and environmental benefits

Avaliação de imagens de diferentes resoluções espaciais para caracterização do índice de vegetação NDVI em vinhedo da região da Campanha, Brasil.

A viticultura de precisão vem se desenvolvendo de forma crescente e, a partir da realização de pesquisas, vem ganhando cada vez mais espaço na agricultura. Visando melhorias no desenvolvimento da vitivinicultura, tanto no sentido de redução de custos, quanto na otimização da utilização de insumos, os métodos de geotecnologias, tais como as de sensoriamento remoto, têm sido utilizados

Orbital images for spatial and temporal characterization of vineyard by vegetation index in the "campanha gaúcha" wine region, Brazil.

ABSTRACT Remote sensing has become an important technique for spatial characterization and agricultural monitoring, in order to improve wine development and reduce production costs. The wine region of the ?Campanha Gaúcha?, Brazil, was recognized in 2020 as an Indication of Origin for quality wines. This study analyzed orbital data in a ?Cabernet sauvignon? vineyard in the municipality of Santana do Livramento. From the images of the Planet and Sentinel-2 satellites, the Normalized Difference Vegetation Index (NDVI) was evaluated, as well as its viability in viticulture in the region. Twelve images from each satellite were analyzed using digital image processing techniques, average NDVI temporal profiles were generated and analyzed by statistical methods. The generated maps produced zoning for each scene over the period studied, for both satellite images. The results showed that the two satellites were suitable for use in monitoring vineyards, due to their excellent temporal, spatial and radiometric resolution. Keywords: NDVI, precision viticulture, remote sensing, Sentinel 2, Planet IMAGENS ORBITAIS PARA CARACTERIZAÇÃO ESPACIAL E TEMPORAL DA VINHA POR ÍNDICE VEGETATIVO NA REGIÃO VITIVINÍCOLA CAMPANHA GAÚCHA, BRASIL RESUMO O sensoriamento remoto tem se tornado importante técnica de caracterização espacial e monitoramento agrícola, a fim de melhorar o desenvolvimento do vinho e reduzir os custos de produção. A região vitivinícola da ?Campanha Gaúcha?, Brasil, foi reconhecida em 2020 como Indicação de Origem para vinhos de qualidade. Este estudo analisou dados orbitais em um vinhedo de ?Cabernet sauvignon? no município de Santana do Livramento. A partir das imagens dos satélites Planet e Sentinel-2, avaliou-se o Índice de Vegetação por Diferença Normalizada (NDVI), bem como sua viabilidade em viticultura na região. Doze imagens de cada satélite foram analisadas usando técnicas de processamento digital de imagens, perfis temporais médios de NDVI foram gerados e analisados por métodos estatísticos. Os mapas gerados produziram zoneamentos para cada cena ao longo do período estudado, para ambas as imagens de satélite. Os resultados mostraram que os dois satélites são adequados para utilização na monitorização de vinhas, devido à sua excelente resolução temporal, espacial e radiométrica. Palavras-chave: NDVI, viticultura de precisão; sensoriamento remoto, Sentinel 2, Plane

Simple Synthesis of Pyrazole-derived Dithioethers

A number of pyrazole-derived dithioethers were prepared by the reaction of diisothiuronium salts and 2-(3,5-dimethylpyrazol-1-yl)ethanol tosylate in a basic aqueous solution. Diisothiuronium salts were prepared by the reaction of thiourea with alpha,omega-dibromoalkanes containing from two to nine methylene groups. The use of these salts allowed in situ generation ions dithiolate, thus eliminating the need to use hazardous dimercaptans

Produção de silagem com a utilização de recursos forrageiros nativos.

Regions such as the Pantanal are still lacking technologies that optimize the use of native forage resources. With the objective of evaluating two forage resources of the region, capybara grass and bocaiuva in silage production, this study evaluated the fermentation parameters and the bromatological composition of the silage of capybara grass additive with increasing levels of flour of bocaiuva. The experimental design was completely randomized, with five treatments: 0, 3, 6, 9 and 12% inclusion of bocaiuva flour and four replications. The material was chopped, mixed and compacted in experimental silos, stored for 50 days. The addition of bocaiuva flour in capybara silage increased the dry matter content and the fermentative characteristics of the silages (pH and N-NH3). Thus, the flour of bocaiuva can be used as an additive, as it provides improvement in the fermentation parameters and in the qualitative characteristics of the silages. Under the conditions of this study, the addition of 3% of bocaiuva flour in the silage of capybara grass was sufficient for better nutritional quality of the silage.Zootec 2019