Structural changes in the duration of bull markets and business cycle dynamics

This paper tests for structural changes in the duration of bull regimes in 18 developed and emerging economies’ adjusted market capitalization stock indexes, by using the novel approach of Nicolau (Econ Lett 146:64–67, 2016) as well as two additional new procedures introduced here; and investigates whether the structural changes detected in the bull markets’ duration are connected to the business cycle. We conclude that changes in the duration of bull market regimes seem to precede periods of economic recession. The results provide statistically significant evidence that decreases in bull markets’ duration do not occur independently from economic crises, as 13 out of the 18 markets considered in our sample verify such decreases at least 12 months prior to the occurrence of an economic crisis. Additionally, these structural changes seem to affect smaller companies first, and then the larger ones. The association between decreases in the bull market regimes’ duration and economic crises is possibly a consequence of financial markets’ leading behavior over the economy. These structural changes may serve as proxies for decreasing confidence in financial markets, which naturally affects economic stability.authorsversionpublishe

Experimental research on structural concrete masonry walls subjected to fire

The construction in masonry is one of the oldest ways of construction. However, the knowledge regarding its structural behavior is still not well consolidated, especially regarding extreme conditions, such as fire. Although the few available studies regarding structural masonry under fire conditions show some promising results, still the available normative documents seem to have some limitations regarding the topic, which highlights the need for further research, especially experimental, in this field. This paper presents the results of a study on the behavior of structural masonry walls subjected to simulated fire conditions. The specimens were built with three cells concrete blocks, which are common in European and US construction. In the fire resistance tests the walls were subjected to the action of a serviceability in-plane load and the ISO 834 fire curve. Temperatures were measured in the furnace, while temperatures and displacements were measured in the specimens. The obtained results were also compared with the Eurocode 6 part 1.2 predictions, for similar cases

Finite Sample Performance of Frequency and Time Domain Tests for Seasonal Fractional Integration

Testing the order of integration of economic and financial time series has become a conventional procedure prior to any modelling exercise. In this paper, we investigate and compare the finite sample properties of the frequency domain tests proposed by Robinson (1994) and the time domain procedure proposed by Hassler, Rodrigues and Rubia (2008) when applied to seasonal data.

Territory and Sustainable Tourism Development: a Space-Time Analysis on European Regions

In the long run, tourism competitiveness depends on the sustainable use of territorial assets: the differentiation of destinations depends on the integration of cultural and natural resources into the tourism supply, but also on their preservation over time. The link between competitiveness and sustainability is the staring point for our analysis of the relationships between regional tourism competitiveness, the dynamics of tourism demand and investment and the existence of natural resources and cultural assets in European regions, by using advanced spatial econometric techniques. Despite the close relationship between tourism activities and the characteristics of the territory, the application of methods of spatial analysis methods in tourism studies is still scarce and the results of this work clearly show their potential for this field of research. Among the main findings of this paper, it was observed that natural resources do not have the expected positive impacts on regional tourism competitiveness and that European regions with more abundant natural resources are often developing unsustainable forms of mass tourism, with low value added and scarce benefits for the host communities. The existence of spatial correlation effects suggests that positive spillovers arising from tourism dynamics in neighbourhood regions prevail over potential negative effects related to the competition between destinations. Policy and managerial implications of these results are discussed and further research questions are suggested

Propriedades mecânicas residuais de betões normais e de alta resistência após incêndio

O efeito das altas temperaturas no betão traduz-se numa diminuição das suas propriedades mecânicas residuais. Tal redução verifica-se quer no betão normal quer no betão de alta resistência. Neste estudo são apresentadas as alterações provocadas pela temperatura nas propriedades residuais - resistência à compressão, resistência à tracção, resistência à flexão e módulo de elasticidade - obtidas em ensaios experimentais com betão normal e confrontadas com os resultados existentes em bibliografia técnica de betão de alta resistência

Resistência à compressão a altas temperaturas dum betão com adição de fibras de aço e têxteis recicladas de pneu

Na construção civil o aproveitamento de materiais reciclados, nomeadamente na fabricação do betão, é cada vez mais uma realidade viável. Neste sentido, temos vindo a assistir ao estudo de betão com a introdução de resíduos de pneu juntamente com os constituintes comuns – agregados, cimento e água. Com esta investigação pretende-se avaliar experimentalmente a resistência à compressão do betão com fibras de aço e fibras têxteis provenientes da reciclagem de pneus, à temperatura ambiente e a altas temperaturas. Neste trabalho foram estudadas cinco composições de betão, com a mesma relação água/cimento (W/C=0,43), diferindo apenas no tipo e quantidade de fibras incorporadas nas misturas em substituição da brita. Assim, estudou-se uma composição de referência (0% de fibras), uma composição com 30 e outra com 70 kg/m3 de fibras de aço recicladas de pneu e uma composição com 2 e outra com 4 kg/m3 de fibras têxteis recicladas de pneu. Os provetes de betão foram submetidos a um nível de carregamento de 0,5fcd e a diferentes níveis de temperatura máxima (20, 300, 500 e 700ºC)

Experimental testing on the residual mechanical properties of ordinary concretes after fire

Concrete is known to have an enhanced behaviour in fire when comparing with bare steel, however there are some chemical and physical transformations in function of temperature that may compromise this performance. The mechanical and thermal properties of concrete at high temperatures and after fire have changes that have been evaluated in a lot of works around the World, however this is still an open field where a lot of research is needed. This paper summarizes the results of an experimental research to assess the residual mechanical properties of ordinary concretes after fire. It was studied the influence of the fire extinguishing methods, the maximum temperature that the concrete was subjected to and the loading level on the residual mechanical properties of calcareous and granite aggregate concretes. The properties studied were the residual compressive, tensile, splitting and flexural strengths and modulus of elasticity. Four levels of temperature; 20ºC, 300ºC, 500ºC and 700ºC; two loading levels (0.3fcd and 0.7fcd) and two cooling processes (cooling in the air and by water jet) were tested. The results showed that the mechanical properties of concretes are affected by the cooling process (fire extinguishing methods) used beyond the high temperatures and loading levels that were subjected to

Orientalismos americanistas: Vicente Fidel López, Francisco Adolfo de Varnhagen y los indígenas

This article analyzes Francisco Adolfo de Varnhagen´s and Vicente Fidel López’ respective theories on the origins of the Tupi and Peruvian Indians. In particular, it puts forward that the historicist approach of the authors’ theories can be attributed to the linguistic contributions of orientalism. The principal aim of this work is to shed light on the connections, in both authors’ works, between indigenism, linguistics, historiography and political plans for Argentina and Brazil.Este artículo examina las teorías acerca de los orígenes de los indígenas tupís, de Francisco Adolfo de Varnhagen, y de los indígenas peruanos, de Vicente Fidel López. Se propone que la deriva historicista de esas teorías se debía a los aportes lingüísticos del orientalismo. El objetivo de este trabajo es arrojar luz sobre las relaciones, en ambos autores, entre indigenismo, lingüística, historiografía y proyectos políticos para Argentina y Brasil

Classification of electroencephalogram signals using artificial neural networks

The study of Artificial Neural Networks (ANN) has proved to be fascinating over the years and the development of these networks has grown strongly in recent years. The neural networks have come to be increasingly convincing methods for solving complex problems, through artificial intelligence. In particular this work focused on development of an artificial neural network for identifying diseases: Parkinson's, Huntington's and Amyotrophic Lateral Sclerosis, based on signals from the Electroencephalogram (EEG). The phases of the project were developed through a number of operations implemented in Matlab. The Fourier transform was seen as the main technique of signal processing, in order to analyze and diagnose diseases in the study. The work consisted in the first stage process the EEG signals to serve as an entry into the ANN in order to reveal a distinctive feature in the different diseases studied, and then, create a model capable to distinguish the diseases. For this purpose 4 methodologies were used with different processing of the EEG signal. The 4 methodologies are compared in this paper