58 research outputs found

    Semiparametric models and P-splines

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    P-splines were introduced by Eilers and Marx (1996). We consider semiparametric models where the smooth part of the model can be described by P-splines. A mixed model representation is also considered. We set a simple strategy for the choice of P-spline parameters, ndx, bdeg and pord, and discuss the use of various criteria for smoothing parameter selection. We illustrate our remarks with the analysis of a randomised block design

    SEMIPARAMETRIC MODELS AND P-SPLINES

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    P-splines were introduced by Eilers and Marx (1996). We consider semiparametric models where the smooth part of the model can be described by P-splines. A mixed model representation is also considered. We set a simple strategy for the choice of P-spline parameters, ndx, bdeg and pord, and discuss the use of various criteria for smoothing parameter selection. We illustrate our remarks with the analysis of a randomised block design.

    WEATHER MODELLING USING A MULTIVARIATE LATENT GAUSSIAN MODEL

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    We propose a vector autoregressive moving average process as a model for daily weather data. For the rainfall variable a monotonic transformation is applied to achieve marginal normality, thus defining a latent variable, with zero rainfall data corresponding to censored values below a threshold. Methodology is presented for model identification, estimation and validation, illustrated using data from Mynefield, Scotland. The new model, a VARMA(2,1) process, fits the data and produces more realistic simulated series than existing methods dur to Richardson (1981) and Peiris and McNicol (1996).

    Penalized functional spatial regression

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    This paper is focus on spatial functional variables whose observa- tions are realizations of a spatio-temporal functional process. In this context, a new smoothing method for functional data presenting spa- tial dependence is proposed. This approach is based on a P-spline estimation of a functional spatial regression model. As alternative to other geostatistical smoothing methods (kriging and kernel smooth- ing, among others), the proposed P-spline approach can be used to estimate the functional form of a set of sample paths observed only at a finite set of time points, and also to predict the corresponding func- tional variable at a new location within the plane of study. In order to test the good performance of the proposed method, two simulation studies and an application with real data will be developed and the results will be compared with functional kriging.Financial support from the project P11-FQM-8068 from Consejería de Innovación, Ciencia y Empresa. Junta de Andalucía, Spain and the projects MTM2013-47929-P and MTM 2011-28285-C02-C2 from Secretaría de Estado Investigación, Desarrollo e Innovación, Ministerio de Economía y Competitividad, Spain

    Derivative curve estimation in longitudinal studies using P-splines

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    The estimation of curve derivatives is of interest in many disciplines. It allows the extraction of important characteristics to gain insight about the underlying process. In the context of longitudinal data, the derivative allows the description of biological features of the individuals or finding change regions of interest. Although there are several approaches to estimate subject-specific curves and their derivatives, there are still open problems due to the complicated nature of these time course processes. In this article, we illustrate the use of P-spline models to estimate derivatives in the context of longitudinal data. We also propose a new penalty acting at the population and the subject-specific levels to address under-smoothing and boundary problems in derivative estimation. The practical performance of the proposal is evaluated through simulations, and comparisons with an alternative method are reported. Finally, an application to longitudinal height measurements of 125 football players in a youth professional academy is presented, where the goal is to analyse their growth and maturity patterns over time.RYC2019-027534-I The Medical Services of Athletic Clu

    Spanish Initiative for the Automation in Urban Transport: AutoMOST

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    The progressive automation of transport will imply a new paradigm in mobility, which will profoundly affect people, logistics of goods, as well as other sectors dependent on transport. It is precise within this automation where the development of new driving technologies is going to cause a great impact on the mobility of the near future, and that will have an effect on the economic, natural and social environment. It is therefore a primary issue at the global level, as it is reflected in the work programs of the European Commission in relation to the road transport [1] [2]. Thus, the size impact is caused by the following novelties and advantages: 1) Safety: Accidents reduction caused by human error; 2) Efficiency increase in transportation, both in energy consumption and time; 3) Comfort for users and professionals who will increase their operational availability to execute other more valuable tasks, both for them and enterprises; 4) Social Inclusion: enabling mobility easily for everybody during more time; 5) Accessibility, to get to city centers and other difficult reach places. It should be noted that the economic impact projected for automated driving for the years to come ranges up to €71 bn in 2030, when estimated global market for automated vehicles is 44 million vehicles, as is reflected in document Automated Driving Roadmap by ERTRAC [3], European Road Transport Research Advisory Council (http://www.ertrac.org/uploads/documentsearch/id38/ERTRAC_Automated-Driving-2015.pdf). As background that already anticipates these im-provements, the Advance Driver Assistance System (ADAs) have already showed the safety increase in the last ten years, but always maintain a leading role for the driver. Related to the efficiency increase, automated driving offers great opportunities for those companies where mobility is a key factor in operating costs, and affects the whole value chain. The project opportunity is consistent with ERTRAC vision, especially in applications focused on the urban environment [4], where it is expected a deployment of the technology of high level automation in an immediate future. This is possible by the potential to incorporate smart infrastructure to improve guidance and positioning, as well as lower speed, which eases its progressive deployment. The objective of AutoMOST is developing technologies for the automation of vehicles in urban transport and industrial applications, to increase significantly the efficiency, safety and environmental sustainability. More specifically, AutoMOST will allow the implementation of shared control systems (Dual-Mode) [5] for future automated vehicles that allow the services operate more efficiently and flexibly, in a context of intelligent and connected infrastructures.This work is supported by the Centre for the Development of Industrial Technology (CDTI) through the CIEN (Consorcios de Investigación Empresarial Nacional) Spanish program. So, the authors would like to thank the CDTI which is a Public Business Entity, answering to the Ministry of Economy and Competitiveness in Spain, which fosters the technological development and innovation of Spanish companies. It is the entity that channels the funding and support applications for national and international R&D&I projects of Spanish companies

    Spectral information to get beyond color in the analysis of water‑soluble varnish degradation

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    Spectral images were captured of paper samples varnished with two water-soluble materials: gum arabic and egg white. The samples were submitted to degradation processes that partially or totally eliminated the varnish from the substrate (water immersion and ageing). The spectral information was used to obtain average color data and to characterize the spatial and color inhomogeneity across pixels, showing that the pixel spectral data are critical for an accurate characterization of the degradation process of the varnishes. Since the varnishes typically become yellower with ageing, this study introduces two novel and simple-to-compute yellowness indices based on the spectral information, which are validated against a standard colorimetric index (ASTM-E313 2015). The potential uses of spectral information are demonstrated with several pieces of a real antique map sample by comparing the spectral information measured before and after cleaning the sample. To sum up, the main contributions of this study are the characterization of the spatial homogeneity through pixel-based spectral and color information and the proposal of spectral-based yellowing indices for two critical applications (ageing process follow-up and effect of cleaning), as demonstrated with synthetic and historical samples of varnished paper respectively.Spanish Ministry of Economy and Competitiveness, under research Grant DPI2015-64571-R. Spanish State Agency of Research (AEI) and the Ministry for Economy, Industry and Competitiveness (MIMECO) by means of the Grant Number FIS2017-89258-P with European Union FEDER (European Regional Development Funds) support

    Estudio colorimétrico de barnices tradicionales aplicados sobre papel sometidos a ensayos de envejecimiento acelerado

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    El empleo de barnices como acabado final en obra gráfica cumple una función estética y protectora. Con el tiempo, o debido a factores adversos, estos barnices pueden sufrir una serie de alteraciones en su color, distorsionando el aspecto original de la obra subyacente. Conocer las variaciones cromáticas de estos materiales resulta esencial de cara a su selección como barniz de conservación. Este trabajo recoge los resultados obtenidos del estudio colorimétrico llevado a cabo sobre una serie de probetas de papel barnizadas sometidas a distintos ensayos físico-químicos (humedad ambiental, inmersión en agua, calor seco y envejecimiento acelerado en cámara climática) que buscan recrear condiciones adversas a las que pueden verse sometidos este tipo de documentos como consecuencia de su envejecimiento natural, la acción de determinados factores de degradación o la acción restauradora. El papel seleccionado como soporte ha sido Somerset 100% algodón al que se le han aplicado distintos barnices de uso tradicional en obra gráfica: goma laca, goma arábiga, clara de huevo, colofonia y dammar). El color de estas probetas se ha estudiado siguiendo el sistema CIEL*a*b* 1976, calculando las diferencias colorimétricas antes y después de los ensayos físico-químicos y de envejecimiento.The use of varnishes as a final coat in graphic work fulfills an aesthetic and protective function. Over time, or due to adverse conditions, these varnishes undergo a series of degradations in their color that can distort the original appearance of the underlying work. Knowing the chromatic variations of these materials is essential for their selection as a conservation varnish. This work collects the results obtained from the colorimetric study carried out on a series of samples of paper with varnish exposing to different physical-chemical tests (humidity, immersion in water, dry heat and accelerated aging) tests that recreate adverse conditions to which this type of woks may be exposed as a consequence of its natural aging, the action of certain degradation factors or the restorative action. For this purpose, Somerset 100% cotton paper has been selected, which has been applied different varnishes of traditional use in graphic works: shellac, gum arabic, egg white, rosin and dammar. The color of these samples has been studied following the CIEL*a*b* 1976 system, calculating the colorimetric differences from the comparison between the reference samples and the samples after the physical-chemical tests

    Effect of OAS genes on SARS-CoV-2 infection and the induction of innate immune responses

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    Resumen del trabajo presentado en el 8th European Congress of Virology, celebrado en Gdańsk (Polonia), del 4 al 7 de mayo de 2023Severe Acute Respiratory Syndrome 2 (SARS-CoV-2) infections cause different clinical symptoms ranging from asymptomatic patients to patients suffering severe respiratory disease leading to death in some of them. Genetic and functional studies have shown inborn-errors of interferon (IFN)-related genes in severe COVID-19 patients explaining why some young patients devoid of co-morbidities succumbed to infection. In addition, very large genomic studies identified common genetic variants affecting the expression and splicing of IFN-stimulated genes (ISGs) of the 2",5"- oligoadenylate (2-5A) synthetase (OAS) family associated with COVID-19 severity. We have sequenced the whole genome of 274 patients who required hospitalization after SARS-CoV-2 infection, finding ultrarare mutations in OAS1 and OAS3 genes. Upon double-stranded (ds)RNA binding, the OAS1, OAS2, and OAS3 proteins synthetize 2¿- 5¿olygoadenylates which activate the endonuclease RNAseL. This endonuclease degrades viral and cellular RNAs, inhibiting viral replication. We have analyzed the effect of OAS1 and OAS3 genetic variants identified in our patients, and found that some of them impair the RNAseL activation. In addition, by using OAS3 knock-out cells generated in our laboratory and performing overexpression experiments, we have shown that OAS3 negatively modulates proinflammatory responses induced by immune challenges, and that the activation of the RNAseL activity seems necessary for this function. In addition, by using OAS3 knock-out mice infected with SARS-CoV-2 or treated with the double-stranded RNA analog poly(I:C), we have shown that OAS3 deficiency leads to a higher mouse susceptibility to SARS-CoV-2 infection and that OAS3 counteracts the induction of innate immune responses in the mouse infectedlungs, leading to a higher inflammatory response in OAS3 knock-out mice, compared to the parental mice. Given the contribution of exacerbated inflammatory responses to COVID-19 disease severity, our results suggest that OAS1/OAS3 could play a role limiting the severity of the clinical symptoms after SARS-CoV-2 infection

    ESC observations of SN 2005cf: II. Optical Spectroscopy and the high velocity features

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    The ESC-RTN optical spectroscopy data-set for SN 2005cf is presented and analyzed. The observations range from -11.6 and +77.3 days with respect to B-band maximum light. The evolution of the spectral energy distribution of SN 2005cf is characterized by the presence of high velocity SiII and CaII features. SYNOW synthetic spectra are used to investigate the ejecta geometry of silicon. Based on the synthetic spectra the SiII high velocity feature appears detached at 19500 km/s. We also securely establish the presence of such feature in SN 1990N, SN 1994D, SN 2002er and SN 2003du. On a morphological study both the CaII IR Triplet and H&K absorption lines of SN 2005cf show high velocity features centered around 24000 km/s. When compared with other Type Ia SNe based on the scheme presented in Benetti et al. 2005 SN 2005cf definitely belongs to the LVG group.Comment: A&A accepted for publicatio
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