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ON NEW STRATEGIES TO CONTROL THE ACCURACY OF WENO ALGORITHM CLOSE TO DISCONTINUITIES Ⅱ:CELL AVERAGES AND MULTIRESOLUTION

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Journal of Computational Mathematics 2020年第4期38卷 661-682页

作者： Sergio Amat Juan Ruiz Chi-Wang Shu department of Applied Mathematics and Statistics Universidad Politecnica de CartagenaSpain Division of Applied Mathematics Brown UniversityUSA

This paper is the second part of the article and is devoted to the construction and analysis of new non-linear optimal weights for WENO interpolation capable of rising the order of accuracy close to discontinuities for data discretized in the cell averages.Thus,now we are interested in analyze the capabilities of the new algorithm when working with functions belonging to the subspace L1\L2 and that,consequently,are piecewise smooth and can present jump discontinuities.The new non-linear optimal weights are redesigned in a way that leads to optimal theoretical accuracy close to the discontinuities and at smooth zones.We will present the new algorithm for the approximation case and we will analyze its accuracy.Then we will explain how to use the new algorithm in multiresolution applications for univariate and bivariate functions.The numerical results confirm the theoretical proofs presented.

关键词： WENO Cell averages New optimal weights Multiresolution schemes Im-proved adaption to discontinuities Signal processing

A Toughness Condition for Fractional(k, m)-deleted Graphs Revisited

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Acta Mathematica Sinica,English Series 2019年第7期35卷 1227-1237页

作者： Wei GAO Juan L.G.GUIRAO Yao Jun CHEN department of Mathematics Nanjing University Nanjing 210093 P. R. China School of Information Science and Technology Yunnan Normal University Kunming 650500 P. R. China departamento de Matematica Aplicada y Estadistica. Universidad Politecnica de Cartagena Hospital de Marina 30203-Cartagena Region de Murcia Spain

In computer networks, toughness is an important parameter which is used to measure the vulnerability of the network. Zhou et al. obtains a toughness condition for a graph to be fractional(κ, m)-deleted and presents an example to show the sharpness of the toughness bound. In this paper, we remark that the previous example does not work and inspired by this fact, we present a new toughness condition for fractional(κ, m)-deleted graphs improving the existing one. Finally, we state an open problem.

关键词： Graph fractional factor fractional (κ, m)-deleted graph toughness

Methodology for Obtaining Electricity-Price Patterns in Customer Response Programs

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Journal of Energy and Power Engineering 2011年第11期5卷 1087-1095页

作者： A. Gabaldon A. Guillamon M.C. Ruiz S. Valero M. Ortiz C. Senabre C. Alvarez department of Electrical Engineering Universidad Politeenica de Cartagena Murcia 30202 Spain department of Applied Mathematics and Statistics Universidad Politecnica de Cartagena Murcia 30202 Spain department of Mechanical and Energy Engineering Universidad Miguel Hernandez Alicante 03202 Spain Institute of Energy Engineering Universidad Politecnica de Valencia Valencia 46022 Spain

The main objective of electricity regulators when establishing electricity markets is to decrease the cost of electricity through competition. However, this scenario cannot be achieved without a full participation of the electricity demand by reacting against electricity prices. The aim of this research is to develop tools for helping customers and aggregators to join price and demand response programs, while helping them to hedge against the risk of short-term price volatility. In this way, the capacity of and hybrid methodology (Self-Organizing Maps and Statistical Ward’s Linkage) to classify high electricity market prices is analysed. Besides, with the help of Non-Parametric Estimation, some price-patterns were found in the abovementioned clusters. The contained knowledge within these patterns supplies customer market-based information on which to base its energy use decisions. The interest for this participation of customers in markets is growing in developed countries to obtain a higher elasticity in demand. Results show the capability of this approach to improve data management and select coherent policies to accomplish cleared demand offers amongst different price scenarios in a more flexible way.

关键词：电力价格客户程序电力市场电力监管机构自组织映射非参数估计电力成本

Characterization of Vertical Wind Speed Profiles Based on Ward's Agglomerative Clustering Algorithm

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Journal of Modern Power Systems and Clean Energy 2023年第5期11卷 1437-1449页

作者： M.C.Bueso A.Molina-García A.P.Ramallo-González A.Fernández-Guillamón department of Applied Mathematics and Statistics Universidad Politécnica de Cartagena30202 CartagenaSpain department of Automatics Electrical Engineering and Electronic TechnologyUniversidad Politécnica de Cartagena30202 CartagenaSpain department of Information and Communications Engineering Computer Science FacultyUniversity of Murcia30100 MurciaSpain universidad de Castilla La-Mancha Campus Universitario02071 AlbaceteSpain

Wind turbine blades have been constantly increasing since wind energy becomes a popular renewable energy source to generate electricity. Therefore, the wind sector requires a more efficient and representative characterization of vertical wind speed profiles to assess the potential for a wind power plant site. This paper proposes an alternative characterization of vertical wind speed profiles based on Ward's agglomerative clustering algorithm, including both wind speed module and direction data. This approach gives a more accurate incoming wind speed variation around the rotor swept area, and subsequently, provides a more realistic and complete wind speed vector characterization for vertical profiles. Real wind database collected for 2018 in the Forschungsplattformen in Nordund Ostsee(FINO) research platform is used to assess the methodology. A preliminary pre-processing stage is proposed to select the appropriated number of heights and remove missing or incomplete data. Finally, two locations and four heights are selected, and 561588 wind data are characterized. Results and discussion are also included in this paper. The methodology can be applied to other wind database and locations to characterize vertical wind speed profiles and identify the most likely wind data vector patterns.

关键词： Clustering algorithm wind speed data management power generation

The Extension degree Conditions for Fractional Factor

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Acta Mathematica Sinica,English Series 2020年第3期36卷 305-317页

作者： Wei GAO Wei Fan WANG Juan L.G.GUIRAO School of Information Science and Technology Yunnan Normal UniversityKunming 650500P.R.China department of Mathematics Zhejiang Normal UniversityJinhua 321004P.R.C hina departamento de Matematica Aplicada y Estadistica.Universidad Politecnica de Cartagena Hospital de Marina30203-CartagenaRegion de MurciaSpain

In Gao’s previous work, the authors determined several degree conditions of a graph which admits fractional factor in particular settings. It was revealed that these degree conditions are tight if b = f(x) = g(x) = a for all vertices x in G. In this paper, we continue to discuss these degree conditions for admitting fractional factor in the setting that several vertices and edges are removed and there is a difference Δ between g(x) and f(x) for every vertex x in G. These obtained new degree conditions reformulate Gao’s previous conclusions, and show how Δ acts in the results. Furthermore,counterexamples are structured to reveal the sharpness of degree conditions in the setting f(x) =g(x) + Δ.

关键词： Fractional factor degree condition independent set

Insecticide Resistance in Field Populations of Bemisia tabaci In Southeastern Spain

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Insecticide Resistance in Field Populations of Bemisia tabac...

The influence of CEO’s financial literacy on SMEs technological innovation:the mediating effects of MCS and risk‑taking

The 5th International Bemisia Workshop

作者： C.Gravalos E.Fernandez B.Bielza. departamento de Produccion Vegetal Escuela Tecnica Superior de Ingenieria AgronomicaUniversidad Politecnica de Cartagena.Paseo Alfonso ⅩⅢ4830203 CartagenaEspana.

＜正＞The spread around the world of Bemisia tabaci Gennadius（Homoptera:Aleyrodidae） Q biotype is of severe concern in several agricultural areas,mainly due to general assumption of higher resistance levels in this biotype.However,most studies on resistance have been carried out from a limited number of populations or with populations collected in Spain some years ago. Our objective was to determine the levels of resistance to insecticides currently

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Financial Innovation 2023年第1期9卷 371-396页

作者： Antonio Duréndez Julio Dieguez‑Soto Antonia Madrid‑Guijarro department of Economics Accounting and FinanceUniversidad Politécnica de CartagenaCalle Real330201 CartagenaSpain Finance and Accounting department Universidad de MálagaCalle El Ejido29071 MalagaSpain Cátedra de Emprendimiento Santander‑UPCT Department of EconomicsAccounting and FinanceUniversidad Politécnica de CartagenaCalle Real330201 CartagenaSpain

Previous literature showed mixed results about the impact of CEOs’financial literacy(CFL)on small and medium-sized enterprises’(SMEs)innovation.This relationship can be motivated by relevant variables,which are missing in the previous literature and make a difference as mediators.In this sense,based on the theoretical framework related to upper echelon theory and resource-based view,this study focuses on the mediating effect of risk-taking attitude and management control systems(MCS)varia-bles.Empirical data from 310 SMEs gathered using a qualitative research questionnaire are analyzed using structural equation modeling methodology.Specifically,estimations are carried out considering the partial least square method.Findings show that MCS and managers’risk attitudes fully mediate the relationship between financial literacy(FL)and innovation.Between these two mediating variables,the implementation of MCS stands out because it also enables the mediating effect of CEOs’risk-taking in the CFL–technological innovation relationship.As the results do not support the significant direct relationship between FL and risk attitude,they confirm an indirect effect through MCS.Furthermore,based on the study findings,SMEs’directors and owners,business associations,and public authorities can improve SMEs’technological innovation by implementing training programs and policies to foster CFL.They can also acknowledge the interdependency between organizational factors and individual characteristics to enhance SMEs’technological innovation.

关键词： Financial literacy Technological innovation Small and medium-sized enterprises Risk-taking Management control systems

CHARACTERISATION OF RATIONAL AND NURBS deVELOPABLE SURFACES IN COMPUTER AIdeD deSIGN

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Journal of Computational Mathematics 2021年第4期39卷 556-573页

作者： Leonardo Fernandez-Jambrina ETSI Navales Universidad Politecnica de Madrid28040-MadridSpain

In this paper we provide a characterisation of rational developable surfaces in terms of the blossoms of the bounding curves and three rational functions∧,M,ν.Properties of developable surfaces are revised in this framework.In particular,a closed algebraic formula for the edge of regression of the surface is obtained in terms of the functions∧,M,ν,which are closely related to the ones that appear in the standard decomposition of the derivative of the parametrisation of one of the bounding curves in terms of the director vector of the rulings and its derivative.It is also shown that all rational developable surfaces can be described as the set of developable surfaces which can be constructed with a constant∧,M,ν.The results are readily extended to rational spline developable surfaces.

关键词： NURBS Bezier Rational Spline NURBS developable surfaces

Prediction of seakeeping in the early stage of conventional monohull vessels design using artificial neural network

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Journal of Ocean Engineering and Science 2023年第4期8卷 344-366页

作者： P.Romero-Tello J.E.Gutiérrez-Romero B.Serván-Camas departamento de Física Aplicada y Tecnología Naval Universidad Politécnica de Cartagena(UPCT)CartagenaMurciaSpain Centre Internacional de Mètodes Numèrics en Enginyeria(CIMNE) BarcelonaSpain

Nowadays seakeeping is mostly analyzed by means of model testing or numerical models.Both require a significant amount of time and the exact hull geometry,and therefore seakeeping is not taken into account at the early stages of ship design.Hence the main objective of this work is the development of a seakeeping prediction tool to be used in the early stages of ship design.This tool must be fast,accurate,and not require the exact hull shape.To this end,an artificial intel-ligence(AI)algorithm has been developed.This algorithm is based on Artificial Neural Networks(ANNs)and only requires a number of ship coefficients of form.The methodology developed to obtain the predictive algorithm is presented as well as the database of ships used for training the ANN.The data were generated using a frequency domain seakeeping code based on the boundary element method(BEM).Also,the AI predictions are compared to the BEM results using both,ship hulls included and not included in the database.As a result of this work it has been obtained an AI tool for seakeeping prediction of conventional monohull vessels.

关键词： artificial neural database