Hasil untuk "History of Portugal"

Filipe Miguel de Andrade Campos

Existentes na Europa desde os tempos medievos, as irmandades foram criadas por particulares e homens devotos da Igreja Católica, com o propósito de estabelecer dinâmicas de âmbito profissional/corporativo, assistencial e devocional ao nível local. Neste trabalho, procedeu-se ao levantamento das confrarias sob invocação das almas ou defuntos no distrito e na cidade de Coimbra. Centra-se, depois, nessas irmandades em duas comunidades, Cadima e Seixo de Gatões, procurando constituir-se como um contributo para o conhecimento das irmandades das almas e defuntos em contexto rural, percecionando-se dinâmicas tanto de índole assistencial, asseguradas na hora da morte, no acompanhamento à sepultura e no sufrágio das almas, como de natureza devocional, que acabavam por se estabelecer como partes integrantes dos quotidianos e identidade destas comunidades. Também se aferirão as sociabilidades promovidas pelos irmãos para o fortalecimento de laços, as penalizações aplicadas aos infratores e os rituais, realidades que os compromissos destas agremiações previam e procuravam instituir e regular.

Ulisses M Portugal

We explicitly compute the effective action from Open Superstring Field Theory in the hybrid formalism to quartic order in the $α'\rightarrow 0$ limit, and show that it reproduces ten-dimensional Super Yang-Mills in terms of four-dimensional superfields. We also show that in this limit the gauge transformations coincide with SYM to all orders, which means that the effective action should reproduce SYM to all orders.

Vinicius Bernardes, Ulisses Portugal

We introduce a two parameter family of string field theory vertices, which we refer to as hyperbolic Kaku vertices. It is defined in terms of hyperbolic metrics on the Riemann surface, but the geometry is allowed to depend on inputs of the states. The vertices are defined for both open and closed strings. In either case, the family contains the hyperbolic vertices. Then we show that the open string lightcone vertex is obtained as the flat limit of the hyperbolic Kaku vertices. The open string Kaku vertices, which interpolate between the Witten vertex and the open string lightcone vertex, is also obtained as a flat limit. We use the same limit on the case of closed strings to define the closed string Kaku vertices: a one parameter family of vertices that interpolates between the polyhedral vertices - which are covariant, but not cubic - and the closed string lightcone vertex - which is cubic, but not Lorentz covariant.

Leandro C. Souza, Bruno C. Guingo, Gilson Giraldi et al.

Since classical machine learning has become a powerful tool for developing data-driven algorithms, quantum machine learning is expected to similarly impact the development of quantum algorithms. The literature reflects a mutually beneficial relationship between machine learning and quantum computing, where progress in one field frequently drives improvements in the other. Motivated by the fertile connection between machine learning and quantum computing enabled by parameterized quantum circuits, we use a resource-efficient and scalable Single-Qubit Quantum Neural Network (SQQNN) for both regression and classification tasks. The SQQNN leverages parameterized single-qubit unitary operators and quantum measurements to achieve efficient learning. To train the model, we use gradient descent for regression tasks. For classification, we introduce a novel training method inspired by the Taylor series, which can efficiently find a global minimum in a single step. This approach significantly accelerates training compared to iterative methods. Evaluated across various applications, the SQQNN exhibits virtually error-free and strong performance in regression and classification tasks, including the MNIST dataset. These results demonstrate the versatility, scalability, and suitability of the SQQNN for deployment on near-term quantum devices.

Paulo Motta, Gustavo A. Bezerra, Anderson F. P. Santos et al.

The Hiperwalk package is designed to facilitate the simulation of quantum walks using heterogeneous high-performance computing, taking advantage of the parallel processing power of diverse processors such as CPUs, GPUs, and acceleration cards. This package enables the simulation of both the continuous-time and discrete-time quantum walk models, effectively modeling the behavior of quantum systems on large graphs. Hiperwalk features a user-friendly Python package frontend with comprehensive documentation, as well as a high-performance C-based inner core that leverages parallel computing for efficient linear algebra calculations. This versatile tool empowers researchers to better understand quantum walk behavior, optimize implementation, and explore a wide range of potential applications, including spatial search algorithms.

Catarina J. Pinho, Mohammed Darwish, Jiří Šmíd et al.

DNA metabarcoding is widely used for diet characterization and is becoming increasingly important for biodiversity conservation, allowing the understanding of trophic networks and community assemblies. However, to our knowledge, few studies have used this approach to investigate trophic interactions for whole communities and none for reptiles. In particular, few studies have examined the diet composition of Saudi Arabian reptiles, and all have used classical methods only. Therefore, in this work, a non-invasive approach using DNA metabarcoding of faecal pellets was implemented to investigate the diet composition of the reptile community of Wadi Ashar, in AlUla County, north-western Saudi Arabia Kingdom. In the overall diet composition of the community, arthropods were present in 90% of the samples, and plants were present in 63%, revealing the unforeseen importance of plants to this community as a secondary, but also a primary dietary item. For some species, this is the first time that plants have been reported in their diet. A significant effect of reptile body size on diet composition was also demonstrated, indicating its strong influence on prey selection and resource partitioning in the community. This study highlights the importance of community assessments and the power of combining these with non-invasive DNA metabarcoding to accurately assess biodiversity and feeding habits, revealing unknown ecological interactions of often neglected groups. This revolutionary tool for conservation and management provided rapid and holistic information at relatively low costs, allowing to inform local authorities about which elements are central to the sustainable management of the Wadi Ashar community.

Sian Sullivan, Michèle Baussant, Lindsey Dodd et al.

This introductory paper outlines the conceptual framework and case studies comprising the research project Disrupted Histories, Recovered Pasts. Our project proposes a cross-disciplinary analysis and cross-case synthesis of experience and memory in post-conflict and postcolonial contexts. In the post- conflict and colonial contexts of our cases, we see “disruption” as present in three senses: as the productive ways in which multiple experiences retrieved through oral histories may refract and revise historical analysis; as the happening histories of objectively disruptive events break the flow of individual and collective experience; and as a strategy for cross-disciplinary research to disrupt and democratise conventional understanding by drawing attention to occluded experiences. We also articulate “recovery” as polysemic: invoking retrieval of past experiences and the possibility for enhanced well-being through voicing memories that may have been suppressed, as well as attending to mismatches with public discourses about displaced groups and individual experience. Following an introduction to our conceptual approach, we summarise our case-research. We have conducted oral history and archival research in multiple contexts, from disciplinary bases in anthropology and history. Our aim has been to interrogate relationships between oral histories and amateur histories with more formal written archives and historiography in a series of disrupted settings: evictions in colonial and apartheid west Namibia (SULLIVAN); memories and historical interpretations of the Egyptian Jewish diaspora (BAUSSANT); the evacuation of children in Second World War France (DODD); recent maritime exodus of migrants from Africa (OTELE); and rupture from a hegemonic imperial-nostalgic narrative in Portugal (DOS SANTOS). Our case research is complemented in the concluding paper of this Special Issue by systematic cross-case engagement, synthesis and theorisation of our case-study research.

Masayuki Nakahata

The first solar neutrino experiment led by Raymond Davis Jr. showed a deficit of neutrinos relative to the solar model prediction, referred to as the "solar neutrino problem" since the 1970s. The Kamiokande experiment led by Masatoshi Koshiba successfully observed solar neutrinos, as first reported in 1989. The observed flux of solar neutrinos was almost half the prediction and confirmed the solar neutrino problem. This problem was not resolved for some time due to possible uncertainties in the solar model. In 2001, it was discovered that the solar neutrino problem is due to neutrino oscillations by comparing the Super-Kamiokande and Sudbury Neutrino Observatory results, which was the first model-independent comparison. Detailed studies of solar neutrino oscillations have since been performed, and the results of solar neutrino experiments are consistent with solar model predictions when the effect of neutrino oscillations are taken into account. In this article, the history of solar neutrino observations is reviewed with the contributions of Kamiokande and Super-Kamiokande detailed.

A. Udy, J. P. Baptista, N. Lim et al.

Z. Csiki-Sava, E. Buffetaut, A. Ősi et al.

Abstract The Late Cretaceous was a time of tremendous global change, as the final stages of the Age of Dinosaurs were shaped by climate and sea level fluctuations and witness to marked paleogeographic and faunal changes, before the end-Cretaceous bolide impact. The terrestrial fossil record of Late Cretaceous Europe is becoming increasingly better understood, based largely on intensive fieldwork over the past two decades, promising new insights into latest Cretaceous faunal evolution. We review the terrestrial Late Cretaceous record from Europe and discuss its importance for understanding the paleogeography, ecology, evolution, and extinction of land-dwelling vertebrates. We review the major Late Cretaceous faunas from Austria, Hungary, France, Spain, Portugal, and Romania, as well as more fragmentary records from elsewhere in Europe. We discuss the paleogeographic background and history of assembly of these faunas, and argue that they are comprised of an endemic ‘core’ supplemented with various immigration waves. These faunas lived on an island archipelago, and we describe how this insular setting led to ecological peculiarities such as low diversity, a preponderance of primitive taxa, and marked changes in morphology (particularly body size dwarfing). We conclude by discussing the importance of the European record in understanding the end-Cretaceous extinction and show that there is no clear evidence that dinosaurs or other groups were undergoing long-term declines in Europe prior to the bolide impact.

Hajime Tanaka, Mohamed Sabri, Renato Portugal

The spatial search problem aims to find a marked vertex of a finite graph using a dynamic with two constraints: (1) The walker has no compass and (2) the walker can check whether a vertex is marked only after reaching it. This problem is a generalization of unsorted database search and has many applications to algorithms. Classical algorithms that solve the spatial search problem are based on random walks and the computational complexity is determined by the hitting time. On the other hand, quantum algorithms are based on quantum walks and the computational complexity is determined not only by the number of steps to reach a marked vertex, but also by the success probability, since we need to perform a measurement at the end of the algorithm to determine the walker's position. In this work, we address the spatial search problem on Johnson graphs using the coined quantum walk model. Since Johnson graphs are vertex- and distance-transitive, we have found an invariant subspace of the Hilbert space, which aids in the calculation of the computational complexity. We have shown that, for every fixed diameter, the asymptotic success probability is $1/2$ after taking $π\sqrt N/(2\sqrt 2)$ steps, where $N$ is the number of vertices of the Johnson graph.

Mikhail Shubov

Motive and electrical energy has played a crucial role in human civilization. Since Ancient times, motive energy played a primary role in agricultural and industrial production as well as transportation. At that time, motive energy was provided by work of humans and draft animals. Later, work of water and wind power was harnessed. During the 19$^{\text{th}}$ century, steam power became the main source of motive energy in USA and Britain. Modern transportation and industry depend on the work of heat engines that use fossil fuel. A brief history of different sources of energy is presented in this work. The energy consumptions in pre-industrial and industrial societies are calculated. The lost opportunities for the Second Industrial Revolution (such as fast breeder reactors and thermonuclear power stations) are discussed. The case that the Solar Power will become the main source of energy by the second half of this century is presented. It is calculated that the Solar Power has the potential to bring about the new Industrial Revolution. Based on material and energy resources available in the Solar System, it is demonstrated that the Solar System Civilization supporting a population of 10 Quadrillion with a high standard of living is possible.

Hajime Tanaka, Mohamed Sabri, Renato Portugal

Spatial search on graphs is one of the most important algorithmic applications of quantum walks. To show that a quantum-walk-based search is more efficient than a random-walk-based search is a difficult problem, which has been addressed in several ways. Usually, graph symmetries aid in the calculation of the algorithm's computational complexity, and Johnson graphs are an interesting class regarding symmetries because they are regular, Hamilton-connected, vertex- and distance-transitive. In this work, we show that spatial search on Johnson graphs by continuous-time quantum walk achieves the Grover lower bound $π\sqrt{N}/2$ with success probability $1$ asymptotically for every fixed diameter, where $N$ is the number of vertices. The proof is mathematically rigorous and can be used for other graph classes.

R. Reis

Jorge Filipe Figueiredo Fontes, Pamela Peres Cabreira

Este artigo tem por objetivo contribuir para a história do movimento operário através da análise de dois casos de estudo  paradigmáticos, com ocorrência durante o período revolucionário português (1974–1975). Por um lado, a Setenave, uma empresa  de construção e reparação naval, de capital nacional e internacional, de mão-de-obra masculina, que evolui para controlo operário sendo posteriormente nacionalizada; por outro, a Sogantal, uma empresa têxtil, de capital internacional e mão de obra  feminina, que durante a revolução passa por um processo de autogestão. Estes dois casos são representativos da luta  revolucionária e do fortalecimento da classe operária portuguesa, retratando fenómenos importantes na compreensão do  desenvolvimento da luta de classes no país durante e após a Revolução dos Cravos. 

Michel Dennefeld

The Magellanic Clouds were known before Magellan's voyage exactly 500 years ago, and were not given that name by Magellan himself or his chronicler Antonio Pigafetta. They were, of course, already known by local populations in South America, such as the Mapuche and Tupi-Guaranis. The Portuguese called them Clouds of the Cape, and scientific circles had long used the name of Nubecula Minor and Major. We trace how and when the name Magellanic Clouds came into common usage by following the history of exploration of the southern hemisphere and the southern sky by European explorers. While the name of Magellan was quickly associated to the Strait he discovered (within about 20 years only), the Clouds got their final scientific name only at the end of the 19th century, when scientists finally abandoned Latin as their communication language.

Pedro Teles

The new coronavirus covid-19 has spread very quickly worldwide, leading the World Health Organization (WHO) to declare a state of pandemic. One of the questions many policy makers, and governments are asking themselves is how the spread is going to evolve in time. In this study, I applied an adapted SIR model previously used in South Korea to model the MERS outbreak, which is also caused by a coronavirus, to estimate the evolution of the curve of active cases in the case of the Portuguese situation, using Italian dara. I then construct five different scenarios for the evolution of covid-19 in Portugal. In the out of control scenario, the number of active cases could reach as much as ~40,000 people on the 5th of April (out-of-control scenario). If the self-protective and control are taken in the same level as what was considered for the South Korean model, this number could have be reduced to about 800 cases (scenario 1). Considering that this scenario is now unrealistic, three other scenarios were devised. In all these scenarios, the government measures had a 50\% effectiveness when compared to the measures in Korea. But in scenario 2 the transmission rate $β$ was effectively reduced to 50\%, In this scenario active cases could reach circa 7,000 people. In scenario 3, the transmission rate $β$ was reduced to 70\% of its initial value, in which the number of cases would reach a peak of ~11,000 people. And finally in scenario 4, $β$ was reduced to 80\%. In this scenario, the peak would be reached at about ~13,000 cases. This study shows the importance of control and self-protecting measure to bring down the number of affected people by following the recommendations of the WHO and health authorities. With the appropriate measures, this number can be brought down to ~7,000-13,000 people. Hopefully that will be the case not just in Portugal, but in the rest of the World.

Rubén Castro Redondo

https://doi.org/10.14195/0870-4147_49_17

Cristóvão Mata

O objetivo deste artigo consiste em verificar os índices de natalidade, de geração de filhos ilegítimos e de mortalidade infantil dos filhos dos duques de Coimbra, de Aveiro e de Torres Novas durante os séculos XVI e XVII, e em analisar os percursos de cada indivíduo que atingiu a idade adulta, comparando os valores dos que enveredaram pelo celibato e dos que contraíram matrimónio. Relativamente aos celibatários, procurar-se-á interpretar as escolhas das casas religiosas em que cada um deles se recolheu. No que concerne à amostra dos herdeiros em cujo matrimónio se investiu, serão discutidas as estratégias matrimoniais dos filhos e das filhas de seis varões da Casa de Aveiro, analisando a origem dos respetivos nubentes e os contratos matrimoniais dos primogénitos.

Bruno Chagas, Renato Portugal, Stefan Boettcher et al.

A discrete-time staggered quantum walk was recently introduced as a generalization that allows to unify other versions, such as the coined and Szegedy's walk. However, it also produces new forms of quantum walks not covered by previous versions. To explore their properties, we study here the staggered walk on a hexagonal lattice. Such a walk is defined using a set of overlapping tessellations that cover the graph edges, and each tessellation is a partition of the node set into cliques. The hexagonal lattice requires at least three tessellations. Each tessellation is associated with a local unitary operator and the product of the local operators defines the evolution operator of the staggered walk on the graph. After defining the evolution operator on the hexagonal lattice, we analyze the quantum walk dynamics with the focus on the position standard deviation and localization. We also obtain analytic results for the time complexity of spatial search algorithms with one marked node using cyclic boundary conditions.