935 resultados para Historical evolution of the concept
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Software evolution, and particularly its growth, has been mainly studied at the file (also sometimes referred as module) level. In this paper we propose to move from the physical towards a level that includes semantic information by using functions or methods for measuring the evolution of a software system. We point out that use of functions-based metrics has many advantages over the use of files or lines of code. We demonstrate our approach with an empirical study of two Free/Open Source projects: a community-driven project, Apache, and a company-led project, Novell Evolution. We discovered that most functions never change; when they do their number of modifications is correlated with their size, and that very few authors who modify each; finally we show that the departure of a developer from a software project slows the evolution of the functions that she authored.
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In this contribution we simulate numerically the evolution of a viscous fluid drop rotating about a fixed axis at constant angular velocity ? or constant angular momentum L, surrounded by another viscous fluid. The problem is considered in the limit of large Ekman number and small Reynolds number. In the lecture we will describe the numerical method we have used to solve the PDE system that describes the evolution of the drop (3D boundary element method). We will also present the results we have obtained, paying special attention to the stability/instability of the equilibrium shapes.
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The accuracy of Tomás López´s historical cartography of the Canary Islands included in the “Atlas Particular” of the Kingdoms of Spain, Portugal and Adjacent Islands” is analyzed. For this purpose, we propose a methodology based on Geographic Information Systems (GIS), a comparison of digitized historical cartography population centres with current ones. This study shows that the lineal error value is small for the smaller islands: Lanzarote, El Hierro, La Palma and La Gomera. In the large islands of Tenerife, Fuerteventura and Gran Canaria, the error is smaller in central zones but increases towards the coast. This indicates that Tomás López began his cartography starting from central island zones, accumulating errors due to lack of geodetic references as he moved toward the coast.
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Nearly 3000 slaughterhouses (74% of them public facilities) were built in Spain during the last decades of the nineteenth century and the first half of the twentieth century. The need to comply with new technical requirements and regulations on the hygiene of the meat passed in the 70s and the gradual replacement of public facilities by larger and more modern private slaughterhouses have subsequently led to the closure and abandonment of many of these buildings. Public slaughterhouses generally consisted of several single-storey and open-plan buildings located around a courtyard. Although originally they were preferably located on the outskirts of the towns, many slaughterhouses are now placed inside the built up areas, due to the urban development. The present work aims to contribute to a better understanding of these agro-industrial buildings and to provide ideas for their conservation and reuse. A review on the historical evolution and the architectural features of the public slaughterhouses in Spain is presented and different examples of old vacant slaughterhouses reused to accommodate libraries, offices, community centres, exhibition halls or sports centres, among others, are shown in the paper.
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The understanding of the structure and dynamics of the intricate network of connections among people that consumes products through Internet appears as an extremely useful asset in order to study emergent properties related to social behavior. This knowledge could be useful, for example, to improve the performance of personal recommendation algorithms. In this contribution, we analyzed five-year records of movie-rating transactions provided by Netflix, a movie rental platform where users rate movies from an online catalog. This dataset can be studied as a bipartite user-item network whose structure evolves in time. Even though several topological properties from subsets of this bipartite network have been reported with a model that combines random and preferential attachment mechanisms [Beguerisse Díaz et al., 2010], there are still many aspects worth to be explored, as they are connected to relevant phenomena underlying the evolution of the network. In this work, we test the hypothesis that bursty human behavior is essential in order to describe how a bipartite user-item network evolves in time. To that end, we propose a novel model that combines, for user nodes, a network growth prescription based on a preferential attachment mechanism acting not only in the topological domain (i.e. based on node degrees) but also in time domain. In the case of items, the model mixes degree preferential attachment and random selection. With these ingredients, the model is not only able to reproduce the asymptotic degree distribution, but also shows an excellent agreement with the Netflix data in several time-dependent topological properties.
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The goal of this communication is to offer, through computer-aided design tools, a methodology to recover and virtually reconstruct disappeared buildings of our industrial historical heritage. It will be applied to the case of the flour factory "El Puente Colgante" (The Suspended Bridge) in Aranjuez, which was demolished in 2001. The process is as follows: After a historical analysis of the evolution in time of the flour factory, a field work provides data allowing an info graphic reconstruction of the factory. Once this information has been processed, a lifting of the current state is made with AutoCAD, and a three-dimensional model is built with the Rhinoceros application. Then images of the ensemble are obtained with the applications Rhinoceros and V-Ray, ending with a postproduction with Photoshop. The proposed methodology has permitted to obtain a three-dimensional model of the flour factory ?El Puente Colgante? in Aranjuez, with an accurate virtual reconstruction of its original state prior to demolition. The procedure exposed is susceptible to be generalized for any other example of industrial architecture.
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Concerted evolution is often invoked to explain the diversity and evolution of the multigene families of major histocompatibility complex (MHC) genes and immunoglobulin (Ig) genes. However, this hypothesis has been controversial because the member genes of these families from the same species are not necessarily more closely related to one another than to the genes from different species. To resolve this controversy, we conducted phylogenetic analyses of several multigene families of the MHC and Ig systems. The results show that the evolutionary pattern of these families is quite different from that of concerted evolution but is in agreement with the birth-and-death model of evolution in which new genes are created by repeated gene duplication and some duplicate genes are maintained in the genome for a long time but others are deleted or become nonfunctional by deleterious mutations. We found little evidence that interlocus gene conversion plays an important role in the evolution of MHC and Ig multigene families.
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Over the past decade, the numerical modeling of the magnetic field evolution in astrophysical scenarios has become an increasingly important field. In the crystallized crust of neutron stars the evolution of the magnetic field is governed by the Hall induction equation. In this equation the relative contribution of the two terms (Hall term and Ohmic dissipation) varies depending on the local conditions of temperature and magnetic field strength. This results in the transition from the purely parabolic character of the equations to the hyperbolic regime as the magnetic Reynolds number increases, which presents severe numerical problems. Up to now, most attempts to study this problem were based on spectral methods, but they failed in representing the transition to large magnetic Reynolds numbers. We present a new code based on upwind finite differences techniques that can handle situations with arbitrary low magnetic diffusivity and it is suitable for studying the formation of sharp current sheets during the evolution. The code is thoroughly tested in different limits and used to illustrate the evolution of the crustal magnetic field in a neutron star in some representative cases. Our code, coupled to cooling codes, can be used to perform long-term simulations of the magneto-thermal evolution of neutron stars.
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The Tertiary detritic aquifer of Madrid (TDAM), with an average thickness of 1500 m and a heterogeneous, anisotropic structure, supplies water to Madrid, the most populated city of Spain (3.2 million inhabitants in the metropolitan area). Besides its complex structure, a previous work focused in the north-northwest of Madrid city showed that the aquifer behaves quasi elastically trough extraction/recovery cycles and ground uplifting during recovery periods compensates most of the ground subsidence measured during previous extraction periods (Ezquerro et al., 2014). Therefore, the relationship between ground deformation and groundwater level through time can be simulated using simple elastic models. In this work, we model the temporal evolution of the piezometric level in 19 wells of the TDAM in the period 1997–2010. Using InSAR and piezometric time series spanning the studied period, we first estimate the elastic storage coefficient (Ske) for every well. Both, the Ske of each well and the average Ske of all wells, are used to predict hydraulic heads at the different well locations during the study period and compared against the measured hydraulic heads, leading to very similar errors when using the Ske of each well and the average Ske of all wells: 14 and 16 % on average respectively. This result suggests that an average Ske can be used to estimate piezometric level variations in all the points where ground deformation has been measured by InSAR, thus allowing production of piezometric level maps for the different extraction/recovery cycles in the TDAM.
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The paper analyzes the evolution of the concept of flexicurity in the european context. In this perspective, flexicurity is expressed through the language of the policies, showing an inherent weakness in influencing national reform processes. The essay compare also with the possibility of a re-reading of flexicurity policies, in the light of the theory of capabilities developed by Amartya Sen.
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Introduction. Iceland’s domestic politics and foreign affairs are undergoing drastic changes. After an economic crash, violent protests on the streets of Reykjavik for the first time in Iceland’s history contributed to the defeat of the government. The party system has been altered. A turn has been taken towards Europe after the United States left the island, first by closing its military base in 2006 and then by its clear stance not to assist the country in its economic difficulties. The former close relations with the superpower are unlikely ever to be restored. The EU membership application is placing severe constraints on political parties which are split on the issue and has put in jeopardy the unity of the first left majority in the Icelandic parliament, the Althingi. Society is in a state of flux after an unprecedented economic downscaling and the collapse of almost its entire financial sector – which had boomed rapidly beginning in the mid-1990s. The credibility of politicians, the parliament and the media is in ruins. Iceland’s smallness and its location on the geographical map – one could also say the geopolitical map – has had a profound influence on its domestic and foreign affairs. Iceland is closely associated with the other Nordic states and has adopted many of their domestic characteristics, with important exceptions. On the other hand, the country has come under American influence – geographically, it straddles the Mid-Atlantic rift – and has limited its participation in the European project. Its geographical location in the middle of the North Atlantic has led to a notion that the country’s culture is unique and should be protected by all available means. Politicians continue to play the ‘nationalistic uniqueness’ card with considerable success even though the country has been swept by globalization. Rapid modernization (which only really began in the Second World War with British and American occupations) and sudden engagement with the outside world (which only extended to the general public in the last quarter of the twentieth century) are still slowly but steadily making their mark on the country’s foreign policy. The country’s political discourse and foreign policy still bear the hallmark of the past, i.e. of a small and insular society This paper will address the political developments in Iceland since the 2008 economic crash and place it in a historical context. The aim is to understand Iceland’s present foreign policy and, in particular, the highly contested decision by its government in 2009 to apply for membership of the European Union. The paper is divided into five sections in addition to this introduction and the concluding remarks. First, it starts by explaining the importance in Iceland of a political discourse based on the concept of independence which dates back to the historical narrative of the settlement period. This section will also examine Iceland’s close relations with the other Nordic states – despite important differences between it and the others. Second, the paper will analyse the importance of the party system, i.e. the dominance of the centre-right in Icelandic politics, and the changed nature of the system. Third, it examines how Iceland further distinguishes itself from the other Nordic states in many important features. Fourthly, the paper analyses the country’s three main foreign policy priorities in the post-war period, i.e. extensions of the Exclusive Economic Zone, firm defence arrangements with the US and membership of NATO, and the drive for better market access for marine products – including a partial engagement in the European project. Fifthly, the paper examines how the country’s smallness, in terms of its central administrative capacity, has affected its domestic and foreign policy-making. The concluding section summarizes the main findings concerning the political and historical obstacles that the Social Democratic Alliance faces in its hard-fought battle to change the country’s European Policy.
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Mode of access: Internet.
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Each part has special t.-p.
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Based on: Evolution of the Division of Meat, Poultry and Livestock Inspection. Springfield, Ill. : Illinois Dept. of Agriculture, 1982.
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An account of the celebration by the New York historical society of the 50th anniversary of Washington's inauguration: p. [121]-136.