40 research outputs found

    GomJau-Hogg´s Notation for Automatic Generation of k-Uniform Tessellations with ANTWERP v3.0

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    ABSTRACT: Euclidean tilings are constantly applied to many fields of engineering (mechanical, civil, chemical, etc.). These tessellations are usually named after Cundy & Rollett’s notation. However, this notation has two main problems related to ambiguous conformation and uniqueness. This communication explains the GomJau-Hogg’s notation for generating all the regular, semi-regular (uniform) and demi-regular (k-uniform, up to at least k = 3) in a consistent, unique and unequivocal manner. Moreover, it presents Antwerp v3.0, a free online application, which is publicly shared to prove that all the basic tilings can be obtained directly from the GomJau-Hogg’s notation

    Structural analysis of a deployable double-layer tensegrity grid

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    Congreso celebrado en la Escuela de Arquitectura de la Universidad de Sevilla desde el 24 hasta el 26 de junio de 2015.Different methods have been used recently to discover new families of a type of space frame: Double- Layer Tensegrity Grids (DLTGs). The main objective of this work is analyzing the process for the design and calculation of a specific deployable DLTG (DDLTG) at full scale (4x4x1 m) composed by 16 modules of 1x1x1 m. Three CAD/CAE tools were used for these purposes: ToyGL, Matlab/Octave, and Midas Civil. It was necessary to create an intermediate platform to exchange data and information between both tools, the ToyGL Processor, based on user-defined functions written in VBA for Microsoft Excel. The methodology was validated by comparing the results obtained by the first two software tools with those provided by Midas Civil. As a conclusion, ToyGL is reliable and accurate in terms of the definition of geometry, distribution of stresses and forces, reactions, states of self-stress, mechanisms, etc

    Novel Technique for Obtaining Double-Layer Tensegrity Grids

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    Double-layer tensegrity grids (DLTGs) may be defined as tensegrity spatial systems containing two parallel horizontal networks of members in tension forming the top and bottom layers, whose nodes are linked by vertical and/or inclined bracing members in compression and/or tension. In this paper, a new approach is described. Conventional double-layer grids (DLGs) are composed of three layers: top, bottom and bracing members. This paper shows new rules for generating original DLGs following a recent methodology for their composition, from the mosaic of the bracing members and additional laws. Finally, from them, a new technique, known as Rot- Umbela manipulation, is applied to obtain their tensegrity form, opening and endless catalogue of DLTGs

    Information Management and Improvement of Citation Indices

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    Bibliometrics and citation analysis have become an important set of methods for library and information science, as well as an exceptional source of information and knowledge for many other areas. Their main sources are citation indices, which are bibliographic databases like Web of Science, Scopus, Google Scholar, etc. However, bibliographical databases lack perfection and standardization. There are several software tools that perform useful information management and bibliometric analysis importing data from them. A comparison has been carried out to identify which of them perform certain pre-processing tasks. Usually, they are not strong enough to detect all the duplications, mistakes, misspellings and variant names, leaving to the user the tedious and time-consuming task of correcting the data. Furthermore, some of them do not import datasets from different citation indices, but mainly from Web of Science (WoS). A new software tool, called STICCI.eu (Software Tool for Improving and Converting Citation Indices - enhancing uniformity), which is freely available online, has been created to solve these problems. STICCI.eu is able to do conversions between bibliographical citation formats (WoS, Scopus, CSV, BibTex, RIS), correct the usual mistakes appearing in those databases, detect duplications, misspellings, etc., identify and transform the full or abbreviated titles of the journals, homogenize toponymical names of countries and relevant cities or regions and list the processed data in terms of the most cited authors, journals, references, etc

    Generation and nomenclature of tessellations and double-layer grids

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    The aim of this work is to establish a systematic methodology for generating automatically different tessellations and double-layer grids (DLGs) following a defined and specific nomenclature proposed originally for such a task. This particular nomenclature defines the notation of mosaics and DLGs in a synthesized and unique manner, with the advantage that it shows how to generate and design them after the parameters expressed on their own names. As a result, by means of an algorithm and some computational codes, it is possible to recreate in 3D any of those grids directly from their own names. Current nomenclature for tessellations is also analyzed, finding severe disadvantages, such as the excessive length of their notations or their non-uniqueness character. A new nomenclature is proposed in order to define and generate consistently and unequivocally n-uniform mosaics in a consistent manner with the current nomenclature used for the Archimedean (regular and semiregular) tessellations

    Quantitative evaluation of overlaying discrepancies in mobile augmented reality applications for AEC/FM

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    Augmented Reality (AR) is a trending technology that provides a live view of the real and physical environment augmented by virtual elements, enhancing the information of the scene with digital information (sound, video, graphics, text or geo-location). Its application to architecture, engineering and construction, and facility management (AEC/FM) is straightforward and can be very useful to improve the on-site work at different stages of the projects. However, one of the most important limitations of Mobile Augmented Reality (MAR) is the lack of accuracy when the screen overlays the virtual models on the real images captured by the camera. The main reasons are errors related to tracking (positioning and orientation of the mobile device) and image capture and processing (projection and distortion issues). This paper shows a new methodology to mathematically perform a quantitative evaluation, in world coordinates, of those overlaying discrepancies on the screen, obtaining the real-scale distances from any real point to the sightlines of its virtual projections for any AR application. Additionally, a new utility for filtering built-in sensor signals in mobile devices is presented: the Drift-Vibration-Threshold function (DVT), a straightforward tool to filter the drift suffered by most sensor-based tracking systems

    Método de mitigación de impacto visual.

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    Un método para mitigar el impacto visual de una obra de infraestructura, en el que, a partir de un modelo digital del terreno, de una representación geométrica de la intrusión visual causada por una obra de infraestructura en una zona de observación, de una representación geométrica de dicha zona de observación desde la que se visualiza dicha intrusión visual y de una altura de una posible barrera de mitigación a levantar, se realizan las siguientes etapas: calcular numéricamente una superficie del lugar geométrico de los rayos visuales trazados desde dicha zona de observación hasta dicha representación geométrica de la intrusión visual; calcular numéricamente una superficie desplazada de dicho modelo digital del terreno una distancia definida por dicha altura; encontrar todas las curvas de intersección de ambas superficies; de toda la superficie abarcada por dichas curvas de intersección, delimitar la o las regiones en donde dicha superficie desplazada queda por encima de dicha superficie del lugar geométrico de los rayos visuales, siendo dicha región o regiones las zonas donde se consigue mitigar el impacto visual de dicha obra de infraestructura con barreras de altura.Solicitud: 201001331 (13.10.2010)Nº Pub. de Solicitud: ES2353103A1 (25.02.2011)Nº de Patente: ES2353103B2 (02.08.2011

    Torres Quevedo's mechanical calculator for second-degree equations with complex coefficients

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    Leonardo Torres Quevedo worked intensively in analogue calculating machines during the last years of the 19th century. The algebraic calculators were calculating machines in which numbers are represented by quantities of a given physical magnitude(s). The physical result is a magnitude of a physical quantity whose measurement in the coherent unit is the result of the algebraic equation. This article shows the three-dimensional (3D) modelling, virtual reconstruction and simulation of the first mechanical calculating machine for solving second-degree equations with complex coefficients, to prove that the functionality was correct and the machine could be built. Sketches of said machine provide enough information on the shape and mechanisms of the machine. By means of the simulation, it has been possible to prove its operation and feasibility of construction so that it is possible to replicate it as a real physical model. The mechanical calculator for second-degree equations with complex coefficients constituted a major milestone in the technological development of the time and helped to originate and improve the design of other algebraic calculators like the machine for solving eighth-degree equations

    Influence of the oceanographic conditions during spring 2003 on the transport of the Prestige tanker fuel oil to the Galician coast

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    Hydrographic data collected during the cruise HIDROPRESTIGE were combined with meteorological and dynamic data provided by remote sensors and drifting/moored buoys, to describe the surface circulation of the Northern Iberian basin in March–April 2003. Sea surface winds transported the floating Prestige oil slicks from the sinking area to the continental slope off the Rías Baixas in 1/2 month: the surface current intensity was 2% of the wind intensity and it was rotated clockwise 5 from the wind direction. Mesoscale cyclonic and anticyclonic structures west of 10º W increased the residence time of oil patches in the Northern Iberian basin, as compared with the expected southwards flow of the Iberian current (IC). On the other hand, the Iberian poleward current (IPC) formed a marked surface front with coastal waters, preventing the entry of fuel oil into the rías. PAHs in the surface layer during the cruise were <0.5 ug L- 1, except in the Galicia bank ( 1 ug L- 1; where the Prestige tanker was still leaking) and the vicinity of Cape Fisterra ( 1.5 ug L -1; where the convergence front between the IPC and coastal waters vanished)

    Risk categories in COVID-19 based on degrees of inflammation: data on more than 17,000 patients from the Spanish SEMI-COVID-19 registry

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    Background: the inflammation or cytokine storm that accompanies COVID-19 marks the prognosis. This study aimed to identify three risk categories based on inflammatory parameters on admission. Methods: retrospective cohort study of patients diagnosed with COVID-19, collected and followed-up from 1 March to 31 July 2020, from the nationwide Spanish SEMI-COVID-19 Registry. The three categories of low, intermediate, and high risk were determined by taking into consideration the terciles of the total lymphocyte count and the values of C-reactive protein, lactate dehydrogenase, ferritin, and D-dimer taken at the time of admission. Results: a total of 17,122 patients were included in the study. The high-risk group was older (57.9 vs. 64.2 vs. 70.4 years; p < 0.001) and predominantly male (37.5% vs. 46.9% vs. 60.1%; p < 0.001). They had a higher degree of dependence in daily tasks prior to admission (moderate-severe dependency in 10.8% vs. 14.1% vs. 17%; p < 0.001), arterial hypertension (36.9% vs. 45.2% vs. 52.8%; p < 0.001), dyslipidemia (28.4% vs. 37% vs. 40.6%; p < 0.001), diabetes mellitus (11.9% vs. 17.1% vs. 20.5%; p < 0.001), ischemic heart disease (3.7% vs. 6.5% vs. 8.4%; p < 0.001), heart failure (3.4% vs. 5.2% vs. 7.6%; p < 0.001), liver disease (1.1% vs. 3% vs. 3.9%; p = 0.002), chronic renal failure (2.3% vs. 3.6% vs. 6.7%; p < 0.001), cancer (6.5% vs. 7.2% vs. 11.1%; p < 0.001), and chronic obstructive pulmonary disease (5.7% vs. 5.4% vs. 7.1%; p < 0.001). They presented more frequently with fever, dyspnea, and vomiting. These patients more frequently required high flow nasal cannula (3.1% vs. 4.4% vs. 9.7%; p < 0.001), non-invasive mechanical ventilation (0.9% vs. 3% vs. 6.3%; p < 0.001), invasive mechanical ventilation (0.6% vs. 2.7% vs. 8.7%; p < 0.001), and ICU admission (0.9% vs. 3.6% vs. 10.6%; p < 0.001), and had a higher percentage of in-hospital mortality (2.3% vs. 6.2% vs. 23.9%; p < 0.001). The three risk categories proved to be an independent risk factor in multivariate analyses. Conclusion: the present study identifies three risk categories for the requirement of high flow nasal cannula, mechanical ventilation, ICU admission, and in-hospital mortality based on lymphopenia and inflammatory parameters
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