The impact of the Web Summit on Hotel Performance, the case of Lisbon

This study aims to examine the impact of a mega business event—the Web Summit—on local hotels’ key performance indicators. The Web Summit is an annual technology event held in November. Lisbon has been the chosen city for the past 3 years, 2019 making it the fourth. To understand this, daily data collected from STR allowed for a comparative study between hotel performance before and after the Web Summit. We compare the 3 years prior to the event and the last 3 years of the event taking place in Lisbon. The sample size is 63 hospitality companies that range from Economy to Luxury Class and ADR, RevPAR, and Occupancy data. Results show that on the first dates of the event ADR and RevPAR increase up to 115% and occupancy 21% when compared to the previous year. However, on the third year of the event, 2018, these numbers do not see the same increase and remain somewhat similar to the previous year, 2017. This shows that there is major impact on hotel performance justifying the interest governments and other tourism agencies have in attracting these types of events, although after the first impact prices tend to stabilize. The focus on one event only and not compared to other events and other type of event. This study will help Revenue Managers and other decision makers examine the real impact on hotel revenue of such events. They will also be able to preview growth associated to the implementation and support of mega events. This study shows that there are clear benefits in holding big business events, but hoteliers should make better forecasts to yield better results specially when concerning revenues. The before and after daily analysis of key performance indicators is of great value to help hoteliers and practitioners about revenue management pricing strategies regarding this type of events and their long-term impact

Probabilistic estimation of network size and diameter

Determining the size of a network and its diameter are important functions in distributed systems, as there are a number of algorithms which rely on such parameters, or at least on estimates of those values. The Extrema Propagation technique allows the estimation of the size of a network in a fast, distributed and fault tolerant manner. The technique was previously studied in a simulation setting where rounds advance synchronously and where there is no message loss.This work presents two main contributions. The first, is the study of the Extrema Propagation technique under asynchronous rounds and integrated in the Network Friendly Epidemic Multicast (NeEM) framework. The second, is the evaluation of a diameter estimation technique associated with the Extrema Propagation. This study also presents a small enhancement the Extrema Propagation in terms of communication cost and points out some other possible enhancements. Results show that there is a clear trade-off between time and communication that must be considered when configuring the protocol—a faster convergence time implies a higher communication cost. Results also show that its possible to reduce the total communication cost by more than 18% using a simple approach. The diameter estimation technique is shown to have a relative error of less than10% even when using a small sample of nodes.The authors would like to thank Jose Orlando Pereira and Nuno Carvalho for their help in the NeEM integration and testing. This work has been partially supported by FCT and POCI 2010, co-funded by the Portuguese Government and European Union in the FEDER Program

Enabling Seamless Data Security, Consensus, and Trading in Vehicular Networks

Cooperative driving is an emerging paradigm to enhance the safety and efficiency of autonomous vehicles. To ensure successful cooperation, road users must reach a consensus for making collective decisions, while recording vehicular data to analyze and address failures related to such agreements. This data has the potential to provide valuable insights into various vehicular events, while also potentially improving accountability measures. Furthermore, vehicles may benefit from the ability to negotiate and trade services among themselves, adding value to the cooperative driving framework. However, the majority of proposed systems aiming to ensure data security, consensus, or service trading, lack efficient and thoroughly validated mechanisms that consider the distinctive characteristics of vehicular networks. These limitations are amplified by a dependency on the centralized support provided by the infrastructure. Furthermore, corresponding mechanisms must diligently address security concerns, especially regarding potential malicious or misbehaving nodes, while also considering inherent constraints of the wireless medium. We introduce the Verifiable Event Extension (VEE), an applicational extension designed for Intelligent Transportation System (ITS) messages. The VEE operates seamlessly with any existing standardized vehicular communications protocol, addressing crucial aspects of data security, consensus, and trading with minimal overhead. To achieve this, we employ blockchain techniques, Byzantine fault tolerance (BFT) consensus protocols, and cryptocurrency-based mechanics. To assess our proposal's feasibility and lightweight nature, we employed a hardware-in-the-loop setup for analysis. Experimental results demonstrate the viability and efficiency of the VEE extension in overcoming the challenges posed by the distributed and opportunistic nature of wireless vehicular communications

Characterization of masonry under uniaxial tension

Relatório 02-DEC/E-1

Characterization of brick and brick–mortar interface under uniaxial tension

Softening is a gradual decrease of mechanical resistance under a continuous increase of deformation imposed on a material specimen or structure. It is a salient feature of quasi-brittle materials like clay brick, mortar, ceramics, rock or concrete, which fail due to a process of progressive internal crack growth. Such mechanical behavior is commonly attributed to the heterogeneity of the material, due to the presence of different phases and material defects, like flaws and voids. The initial stresses and cracks as well as variations of internal stiffness and strength cause progressive crack growth when the material is subjected to progressive deformation. Initially, the micro cracks are stable which means that they grow only when the load is increased. Around peak load an acceleration of crack formation takes place and the formation of macro cracks starts. The macro cracks are unstable, which means that the load has to decrease to avoid an uncontrolled growth. In a deformation controlled test the macro crack growth results in softening and localization of cracking in a small zone, while the rest of the specimen unloads. For tensile failure this phenomenon has been well identified for concrete but very few results exists for masonry. In the present paper, the results of an extensive set of tests, carried out at University of Minho, including brick specimens and masonry specimens under uniaxial tension will be presented. Both tensile strength and fracture energy are quantified, for different bricks and different types of brick-mortar interface

Avaliação do desempenho produtivo de suínos de raça Alentejana submetidos a acabamento intensivo até elevado peso de abate

A raça autóctone suína Alentejana, com solar na região do Alentejo, tem sido desde sempre explorada em sistemas de produção extensivos ou semi-intensivos, em virtude da sua capacidade para converter os frutos do montado, lande e bolota, em carne e gordura. A montanheira é, no entanto, um recurso limitado, apenas disponível durante uma época do ano e sujeito a variações anuais, pelo que a exploração destes animais em sistema intensivo pode constituir uma alternativa ao sistema tradicional. Avaliou-se o desempenho produtivo, a acumulação de gordura subcutânea e o aumento da espessura do músculo Longissimus dorsi de suínos Alentejanos machos castrados, submetidos a engorda intensiva, até um peso elevado ao abate (160 kg). Analisaram-se dados de 30 animais, ao longo do seu crescimento / engorda intensiva, dos 60 aos 160 kg de PV. Os animais foram pesados semanalmente e a ingestão de alimento, limitada a 4% do PV, controlada individual e diariamente. Avaliou-se por ultra-sonografia aos 60, 90, 120 e 160 kg de PV a espessura do músculo Longissimus dorsi, ao nível do P2 (a 65 mm da linha média ao nível da última costela) e da gordura subcutânea no ponto P2 e sobre a apófise medial da última vertebra lombar. Os GMD dos animais foram de 865 ± 179 g, 1041 ± 207 g e 776 ± 116 g, nos períodos 60-90, 90-120 e 120-160kg, respetivamente. Estes valores de GMD, em acabamento intensivo e, em particular, no período 90-120 kg, são muito superiores aos valores referidos na bibliografia para porcos de raça Alentejana explorados no sistema tradicional. A ingestão alimentar, apesar da sua limitação, foi proporcionalmente mais elevada, que o GMD, o que se traduziu num elevado IC (4,79 ± 0,87, 4,45 ± 1,17 e 6,78 ± 0,92, nos períodos 60-90, 90-120 e 120-160 kg, respetivamente). A espessura de gordura subcutânea ao nível do P2 e da última vertebra lombar apresentaram valores próximos nos vários tempos avaliados. O incremento de acumulação de gordura subcutânea, observado com o aumento de peso do animal, foi particularmente elevado, evidenciando uma elevada capacidade de deposição de tecido adiposo a par do limitado potencial de desenvolvimento muscular, característico da raça suína Alentejana. No sistema de engorda intensivo praticado neste estudo, os animais da raça Alentejana apresentaram um desempenho produtivo pouco interessante, devido a uma reduzida taxa de conversão alimentar, a par do elevado período de tempo necessário para atingir pesos elevados de abate. Os resultados obtidos evidenciaram um forte incremento da gordura subcutânea dorsal, acompanhado de um aumento moderado da espessura do músculo Longissimus dorsi.info:eu-repo/semantics/publishedVersio

Connecting Regional Development to Environmental Education

<p>In this study we investigate how environmental education can be connected with the regional sustainable development We perceive that the dialogues surrounding Environmental Education in formal education have been dividing opinions over the last two decades. This does not happen only in relation to the conceptual precepts, but mainly in relation to the field of activity. Our theoretical support comes from authors engaged with the Critical Environmental Education, signaling for the construction of what we call Reference Framework. Our research is developed from a qualitative perspective, having as a strategy the exploratory case study. For the analysis of the documents we make reference to the methodology of content analysis proposed by Bardin (2011) and reflective application of the Reference Framework. We argue that so far in Brazil, environmental education is divided into two major theoretical trends that reflect the practices of environmental educators. On the one hand, supporting a behaviorist / liberal / conservative tendency of Environmental Education (CARVALHO, 2001; GUIMARÃES, 2000; LOUREIRO, 2008), understand environmental practices from its immediate resolution dimension, focusing actions that situate environmental practices through changes in social behaviors, mostly promoted by environmental activism. On the other hand, we have the opposite, that is, the popular / critical / emancipatory tendency which situates its argumentative and practical content situates in the significant assumption of a new societal posture in relation to the economic models adopted. It establishes the connection between environmental education and local / regional development, delineating a perception of reality, forming a dimension of creating other ways of relating human and non-human, including the emergence of a rationality that impresses ethical socio-environmental values, other forms of understanding of the world and the concept of environmental rationality.</p&gt

Crescimento e qualidade da carcaça de suinos Landrace X Large White submetidos a acabamento intensivo até elevado peso de abate

Ao longo dos últimos anos, em muitos países, e como já é habitual em Itália, o peso vivo de abate de suínos tem registado um progressivo aumento, o que tem sido possível devido ao melhoramento genético de raças industriais, com potencial para produzir mais carne magra. Utilizaram-se 30 suínos, F1 cruzados de Landrace x Large White, castrados, submetidos a acabamento intensivo com alimento composto (Energia Bruta 3833 kcal / kg MS), distribuído ad libitum, até um peso elevado ao abate (90-160 kg de PV). Avaliou-se o desempenho produtivo dos animais, espessura da gordura e profundidade do Longissimus dorsi, in vivo, e peso de carcaça. Os animais foram pesados semanalmente e a ingestão de alimento controlada, individual e diariamente, permitindo calcular os GMD e IC. Efetuaram-se diversas medições, in vivo, da espessura da gordura (P1 - linha média da última vertebra torácica, P2 - a 6 cm da linha média ao nível da última vertebra torácica e P3 - linha média da última vertebra lombar) e da profundidade do Longissimus dorsi, por ultra-sonografia, aos 90, 120 e 160 kg PV. Os animais foram abatidos em matadouro experimental, registando-se o peso de carcaça, a quente e a frio (24 h post mortem), bem como o total das gorduras rejeitadas e miudezas. Os GMD dos animais foram de 828,3 ± 110,3 g e de 673,1 ± 112,2 g, nos períodos 90-120 kg e 120- 160 kg, respetivamente, o que representa um decréscimo de 19% do GMD, entre os períodos considerados. Nos mesmos períodos, os IC foram de 4,27 ± 0,32 e de 4,99 ± 0,49, representando um incremento de 17%. O consumo médio de alimento foi de 3,34 kg / dia. Para as três medições de espessura da gordura efetuadas e da profundidade do Longissimus dorsi, registou-se um crescimento constante ao longo do ensaio, no total de 1,1 cm, e de 1,2 cm, respetivamente. Observou-se apenas uma diferenciação do crescimento do P2, menos acentuado entre os 90 e os 120 kg, mas recuperando, no período 120-160 Kg. Os pesos médios da carcaça, a quente e a frio, foram respectivamente 132,1 Kg e 130 kg, representando 82,4% e 81% do peso vivo ao abate. Obteve-se um peso médio da perna (com chispe) de 19 kg. Os resultados obtidos indiciam uma possível utilização deste cruzamento na produção de suínos em sistema intensivo com objetivo de produção de pernas para presunto e com aproveitamento das restantes peças cárneas.info:eu-repo/semantics/publishedVersio

Quantum cosmology of scalar-tensor theories and self-adjointness

In this paper, the problem of the self-adjointness for the case of a quantum minisuperspace Hamiltonian retrieved from a Brans-Dicke (BD) action is investigated. Our matter content is presented in terms of a perfect fluid, onto which the Schutz's formalism will be applied. We use the von Neumann theorem and the similarity with the Laplacian operator in one of the variables to determine the cases where the Hamiltonian is self-adjoint and if it admits self-adjoint extensions. For the latter, we study which extension is physically more suitable.Comment: Latex file, 12 pages. Small changes made in the paper, and a a new appendix adde