Two Decades of Maude

This paper is a tribute to José Meseguer, from the rest of us in the Maude team, reviewing the past, the present, and the future of the language and system with which we have been working for around two decades under his leadership. After reviewing the origins and the language's main features, we present the latest additions to the language and some features currently under development. This paper is not an introduction to Maude, and some familiarity with it and with rewriting logic are indeed assumed.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Strategic Issues, Problems and Challenges in Inductive Theorem Proving

Abstract(Automated) Inductive Theorem Proving (ITP) is a challenging field in automated reasoning and theorem proving. Typically, (Automated) Theorem Proving (TP) refers to methods, techniques and tools for automatically proving general (most often first-order) theorems. Nowadays, the field of TP has reached a certain degree of maturity and powerful TP systems are widely available and used. The situation with ITP is strikingly different, in the sense that proving inductive theorems in an essentially automatic way still is a very challenging task, even for the most advanced existing ITP systems. Both in general TP and in ITP, strategies for guiding the proof search process are of fundamental importance, in automated as well as in interactive or mixed settings. In the paper we will analyze and discuss the most important strategic and proof search issues in ITP, compare ITP with TP, and argue why ITP is in a sense much more challenging. More generally, we will systematically isolate, investigate and classify the main problems and challenges in ITP w.r.t. automation, on different levels and from different points of views. Finally, based on this analysis we will present some theses about the state of the art in the field, possible criteria for what could be considered as substantial progress, and promising lines of research for the future, towards (more) automated ITP

Measurement of the cross-section and charge asymmetry of WW bosons produced in proton-proton collisions at s=8\sqrt{s}=8 TeV with the ATLAS detector

This paper presents measurements of the $W^+ \rightarrow \mu^+\nu$ and $W^- \rightarrow \mu^-\nu$ cross-sections and the associated charge asymmetry as a function of the absolute pseudorapidity of the decay muon. The data were collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with the ATLAS experiment at the LHC and correspond to a total integrated luminosity of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the 1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured with an uncertainty between 0.002 and 0.003. The results are compared with predictions based on next-to-next-to-leading-order calculations with various parton distribution functions and have the sensitivity to discriminate between them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables, submitted to EPJC. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13

A Formal Theory of Key Conjuring

Key conjuring is the process by which an attacker obtains an unknown, encrypted key by repeatedly calling a cryptographic API function with random values in place of keys. We propose a formalism for detecting computationally feasible key conjuring operations, incorporated into a Dolev-Yao style model of the security API. We show that security in the presence of key conjuring operations is decidable for a particular class of APIs, which includes the key management API of IBM’s Common Cryptographic Architecture (CCA)

Robust aircraft trajectory planning under uncertain convective environments with optimal control and rapidly developing thunderstorms

Convective weather, and thunderstorm development in particular, represents a major source of disruption, delays and safety hazards in the Air Traffic Management system. Thunderstorms are challenging to forecast and evolve on relatively rapid timescales; therefore, aircraft trajectory planning tools need to consider the uncertainty in the forecasted evolution of these convective phenomena. In this work, we use data from a satellite-based product, Rapidly Developing Thunderstorms, to estimate a model of the uncertain evolution of thunderstorms. We then introduce a methodology based on numerical optimal control to generate avoidance trajectories under uncertain convective weather evolution. We design a randomized procedure to initialize the optimal control problem, explore the different resulting local optima, and identify the best trajectory. Finally, we demonstrate the proposed methodology on a realistic test scenario, employing actual forecast data and an aircraft performance model.This work is supported by the Spanish Government through Project entitled Analysis and optimisation of aircraft trajectories under the effects of meteorological uncertainty (TRA2014-58413-C2-2-R)12; this project has been funded under R&D&I actions of Programa Estatal de Investigación, Desarrollo e Innovación Orientada a los Retos de la Sociedad (call 2014).Publicad

Efeitos do processamento por alta pressão nas propriedades físico-químicas e na estabilidade microbiológica de uma salada de fruta

Nowadays consumers are more aware of effects of their diet on their health, demanding natural or minimally processed food products. Thus, research has focused on processes that assure safe products without jeopardizing their nutritional properties. In this context, this work aimed to evaluate the effects of high pressure processing (550 MPa/ 3 min/ 15ºC) on a fruit salad (composed by melon juice and pieces of Golden apple and Rocha pear) throughout 35 days of refrigerated storage. It was analysed its microbiological stability, physicochemical properties, browning degree, enzymatic activity, antioxidant activity and volatile profile. It was observed that processed samples were more microbiologically stable than raw samples, and the titratable acidity results corroborate this conclusion. Regarding browning degree, it was verified a significant increase (p<0.05) in processed samples. It was executed an assay with addition of ascorbic acid (100mg/kg) in order to decrease the browning of the samples, but the concentration used was inefficient. Concerning the antioxidant activity, in general there were no significant differences between raw and processed samples through the 35 days of storage. It was verified an increase in the activity of polyphenol oxidase immediately after processing, being generally similar or higher during storage at 4ºC, compared with raw samples. Regarding the volatile profile of the product, it was verified, as expected, that the compounds associated with melon represented the biggest relative percentage, given that melon juice is the major component of the product. However, processed samples revealed a decrease in the relative quantity of these compounds. Broadly speaking, high pressure processing showed to be efficient in maintaining the stability and overall quality of the product, even though there were some negative effects on the volatile profile of the product. The composition in bioactive compounds must be analysed in the futureHoje em dia os consumidores estão mais conscientes dos efeitos da dieta na sua saúde, procurando alimentos naturais ou pouco processados. Assim, a investigação tem-se concentrado em processos que tornem os alimentos seguros sem afetar as suas propriedades nutricionais. Neste âmbito, o objetivo deste trabalho foi avaliar os efeitos do processamento por alta pressão (550 MPa/ 3 min/ 15º C) numa salada de fruta (composta por sumo de melão, pedaços de maçã Golden e pedaços de pera Rocha) ao longo de 35 dias de armazenamento refrigerado. Foi analisada a estabilidade microbiológica, propriedades físico-químicas, grau de acastanhamento, atividade enzimática, atividade antioxidante e perfil volátil. Observou-se que a nível microbiológico, as amostras processadas demonstraram uma maior estabilidade do que as amostras controlo, sendo que os resultados da análise da acidez titulável corroboram estas observações. Relativamente ao acastanhamento, verificou-se um aumento significativo (p<0.05) nas amostras processadas. Foi feito um ensaio com adição de ácido ascórbico (100 mg/kg) visando a diminuição do acastanhamento das amostras, mas a concentração usada não foi suficientemente eficaz. No que toca à atividade antioxidante, em geral não foram observadas diferenças significativas entre amostras processadas e amostras controlo ao longo dos 35 dias de armazenamento. Observou-se um aumento da atividade da polifenol oxidase imediatamente após o processamento sendo em geral semelhante ou maior ao longo do armazenamento a 4 ºC, comparativamente às amostras controlo. No que diz respeito ao perfil volátil, verificou-se que os compostos associados ao aroma a melão constituem a maior percentagem relativa, como era esperado, tendo em conta que este é o componente maioritário do produto. No entanto, as amostras processadas revelaram uma diminuição na quantidade relativa destes compostos. De uma forma geral, o processamento por alta pressão revelou ser eficaz em manter a estabilidade e qualidade geral do produto, apesar de se verificarem alguns efeitos no perfil volátil do produto. A composição em compostos bioativos deve ser analisada futuramenteMestrado em Biotecnologi