Deductive Verification of Parallel Programs Using Why3

The Message Passing Interface specification (MPI) defines a portable message-passing API used to program parallel computers. MPI programs manifest a number of challenges on what concerns correctness: sent and expected values in communications may not match, resulting in incorrect computations possibly leading to crashes; and programs may deadlock resulting in wasted resources. Existing tools are not completely satisfactory: model-checking does not scale with the number of processes; testing techniques wastes resources and are highly dependent on the quality of the test set. As an alternative, we present a prototype for a type-based approach to programming and verifying MPI like programs against protocols. Protocols are written in a dependent type language designed so as to capture the most common primitives in MPI, incorporating, in addition, a form of primitive recursion and collective choice. Protocols are then translated into Why3, a deductive software verification tool. Source code, in turn, is written in WhyML, the language of the Why3 platform, and checked against the protocol. Programs that pass verification are guaranteed to be communication safe and free from deadlocks. We verified several parallel programs from textbooks using our approach, and report on the outcome.Comment: In Proceedings ICE 2015, arXiv:1508.0459

Diferentes abordagens conceptuais sobre a internacionalização das empresas : uma revisão bibliográfica

<p>A wealth of research has addressed the internationalization of firms using different theories and conceptual perspectives. This paper examines the extant research on internationalization specifically delving into seven streams of research: Market Power, Evolutionary Model, Internalization &amp; Transaction Cost, Eclectic Paradigm, Resource-Based View, Institutional and International New Ventures &amp; Born Global. Methodologically we conduct a bibliometric review in six leading journals recognized for publishing International Business (IB) research, during a forty one year period, from 1970 to 2010. Using citations and co-citations analyses on a sample of 1,459 articles, we sought to better understand the internationalization approaches and how they are interconnected, by examining its growth over time, the most used approaches, the works that have had the greatest impact, and the intellectual interconnections among authors. We conclude that there is no dominant approach in International Business research, albeit the Evolutionary Model has been the most cited - in almost 26% of the extant research, specially the paper– “<em>The internationalization process of the firm: A model of knowledge development and increasing foreign market commitment</em>”, by Johanson and Vahlne (1977). We present a broad discussion and point out limitations and directions for future research.</p

Emerging technologies to promote fans interaction in football events: a systematic review

Review question / Objective: The search terms used for this review were constructed using the PICOS framework: (1) population were people in general of both genders and any age, (2) studies based on digital technologies used in football sportive events, (3) comparisons made in the domains of motivation, interaction, satisfaction and interest, (4) data reporting the use of digital tools (studies with no results reported will be considered, besides not having outcomes), (5) Intervention studies with a pre and post-test design, descriptive studies, theorical studies, and protocol proposals, and (6) articles written in English, Spanish or Portuguese. Condition being studied: Our concern is with the acceptance of the fans returning to the stadium with normality after a pandemic period. In addition, we also want to understand what kind of interactive applications are already on the market or with their well defined protocols that intend to increase fan interaction at live games, increasing their motivation to go to the stadium and to have accurate and updated live information.info:eu-repo/semantics/publishedVersio

Comparative assessment of infiltration, runoff and erosion sprinkler irrigated soils

Abstract The impacts of sprinkler irrigation on infiltration, runoff and sediment loss of ten representative soils of Southern Portugal were assessed by laboratory sprinkler irrigation simulation tests. All soils showed very low permeability to applied water. The mechanical impact of water droplets enhanced soil dispersion and further lowered their infiltration capacity, particularly for high clay plus silt content soils that showed the poorest results. As a consequence, high runoff and sediment losses were also measured, primarily with the first irrigation. More moderate losses were observed thereafter. Soils with higher sand particle size fractions better absorbed the energy impact of droplets and showed higher infiltration rates and lower runoff and sediment losses. Polyacrylamide (PAM) applied to the soils through the irrigation water acted as a binding and settling agent to increase soils aggregate stability and infiltration and reduce runoff and sediment losses. Slope increase, from 2·5 to 5%, decreased overall soils infiltration by 7% and increased runoff and sediment losses by 10 and 27%, respectively. Exposed to the same change in slope, PAM application boosted overall infiltration of treated soils to a 24% difference and increased runoff by only 10%. It had a less positive effect on sediment loss, the 5% slope being responsible for a 52% increase. In agreement with this the tests showed that, compared to the control, exposure of PAM-treated soil on 2·5 and 5% slopes enhanced overall infiltration to 457 and 642% respectively, reduced runoff by 25% on both cases and lessened sediment loss by 39 and 27%. The demonstrated ability of PAM to influence surface soil conditions of specific soils can be used to reduce the environmental risks associated with the intensive use of sprinkler irrigation in Southern Portugal. It offers a safe, practical and non-intrusive management alternative to current costly, labour- and energy-intensive practices of increasing the number of machine turns and building storage basins to control runoff and soil erosion

Response of vertebrate scavengers to power line and road rights-of-way and its implications for bird fatality estimates

Linear infrastructures, such as power lines and roads, are an important source of bird mortality. However, little is known on the potential effect of these infrastructures on local scavenger guilds, their foraging activity and the resulting bird carcass removal patterns. This is an important source of bias in studies aiming to quantify bird fatalities due to linear infrastructures. We used camera-traps to record scavenger identity and persistence patterns of bird carcasses placed close to linear infrastructure and nearby controls in two Mediterranean agricultural regions. We found that linear infrastructure influence on scavenger identity varied depending on the region. Contrary to expectations, linear infrastructure presence had either none or a positive effect on carcass persistence, meaning that carcasses placed within power line or road rights-of-way were not removed faster than the ones placed in controls. We conclude that linear infrastructure effect on vertebrate scavenging patterns is likely to be region-specific, and that reliable correction factors for carcass removal-bias in bird fatality estimates require site-specific experiments to characterize local scavenging processesinfo:eu-repo/semantics/publishedVersio

Water quality on small ruminants’ dairy farms in Castelo Branco region

The importance of providing quality water for cleaning milking machines and other equipment is perhaps one of the most overlooked factors in ensuring milk quality on most dairy farms. Water for cleaning in the dairy barn is used for different situations, including for the process of milking, which requires cleaning and disinfection of the milking equipment, the milking parlour, and the milk cooling tank. Many factors on dairy farms can contribute to contamination of the raw milk, and one of the major factors responsible for this contamination is the water used to clean the milking and storage equipment.This work was financially supported by QRural Research Unit/IPCB and CERNAS-IPCB (UIDB/00681/2020, FCT).info:eu-repo/semantics/publishedVersio

Problem-Based Learning e suas implicações: breve revisão teórica

A ESTSP-IPP implementou em 2008-2009 um novo modelo pedagógico, o PBL, em três licenciaturas. Este modelo tem sido considerado capaz de promover a aquisição de conhecimentos mas também o desenvolvimento de competências transversais valorizadas no mercado de trabalho; orienta-se em torno de problemas significativos da realidade profissional, trabalhados segundo a metodologia dos sete passos, destacando-se a aprendizagem através de pesquisa individual e trabalho de grupo; e visa ainda desenvolver processos cognitivos e metacognitivos como levantar hipóteses, comparar, analisar, interpretar e avaliar. Neste artigo, caracterizamos brevemente o modelo e respectivas implicações, justificando o interesse em investigar as repercussões da sua implementação.In 2008-2009, ESTSP-IPP implemented a new pedagogical model – PBL – in three of its degrees. This model has been recognized as adequate to encourage students to acquire knowledge and develop transversal competences increasingly valued by the labor market. PBL is organized around significant problems from the professional activity, worked from a seven step methodology, encouraging learning through individual research and group work. It promotes the development of several cognitive and metacognitive processes, such as hypothesis raising, comparing, analyzing, interpreting and evaluating. In this article, we briefly characterize PBL and its implications, advocating for the importance of investigating the model’s implementation