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General noise support vector regression with non-constant uncertainty intervals for solar radiation prediction

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journal of Modern Power Systems and Clean Energy 2018年第2期6卷 268-280页

作者： j.PRADA j.R.DORRONSORO Universidad Autonoma de Madrid

General noise cost functions have been recently proposed for support vector regression(SVR). When applied to tasks whose underlying noise distribution is similar to the one assumed for the cost function, these models should perform better than classical -SVR. On the other hand, uncertainty estimates for SVR have received a somewhat limited attention in the literature until now and still have unaddressed problems. Keeping this in mind,three main goals are addressed here. First, we propose a framework that uses a combination of general noise SVR models with naive online R minimization algorithm(NORMA) as optimization method, and then gives nonconstant error intervals dependent upon input data aided by the use of clustering techniques. We give theoretical details required to implement this framework for Laplace, Gaussian, Beta, Weibull and Marshall–Olkin generalized exponential distributions. Second, we test the proposed framework in two real-world regression problems using data of two public competitions about solar energy. Results show the validity of our models and an improvement over classical -SVR. Finally, in accordance with the principle of reproducible research, we make sure that data and model implementations used for the experiments are easily and publicly accessible.

关键词： Support vector regression General noise model Naive online R minimization algorithm(NORMA) Uncertainty intervals Clustering Solar energy Reproducible research

Calculation of transient dynamic stress intensity factors at bimaterial interface cracks using a SBFEM-based frequency-domain approach

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Science China(Physics,Mechanics & Astronomy) 2008年第5期51卷 519-531页

作者： Z.j.YANG A.j.DEEKS College of Civil Engineering and Architecture Zhejiang University School of Civil and Resource Engineering University of Western Australia

A frequency-domain approach based on the semi-analytical scaled boundary finite element method(SBFEM) was developed to calculate dynamic stress intensity factors(DSIFs) at bimaterial interface cracks subjected to transient ***-cause the stress solutions of the SBFEM in the frequency domain are analytical in the radial direction,and the complex stress singularity at the bimaterial interface crack tip is explicitly represented in the stress solutions,the mixed-mode DSIFs were calculated directly by *** complex frequency-response functions of DSIFs were then used by the fast Fourier transform(FFT) and the inverse FFT to calculate time histories of DSIFs.A benchmark example was *** re-sults were obtained by modelling the example with a small number of degrees of freedom due to the semi-analytical nature of the SBFEM.

关键词： scaled boundary finite element method bimaterial interface crack frequency domain dynamic stress intensity factors fast Fourier transform

Distributed Document Clustering Analysis Based on a Hybrid Method

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China Communications 2017年第2期14卷 131-142页

作者： j.E.judith j.jayakumari Noorul Islam Centre for Higher Education KumaracoilIndia

Clustering is one of the recently challenging tasks since there is an *** amount of data in scientific research and commercial applications. High quality and fast document clustering algorithms are in great demand to deal with large volume of data. The computational requirements for bringing such growing amount data to a central site for clustering are complex. The proposed algorithm uses optimal centroids for *** clustering based on Particle Swarm Optimization(PSO).PSO is used to take advantage of its global search ability to provide optimal centroids which aids in generating more compact clusters with improved accuracy. This proposed methodology utilizes Hadoop and Map Reduce framework which provides distributed storage and analysis to support data intensive distributed applications. Experiments were performed on Reuter's and RCV1 document dataset which shows an improvement in accuracy with reduced execution time.

关键词： distributed document clustering hadoop k-means PSO mapreduce

The circular dataimage, a graph for high-resolution circular-spatial data

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International journal of Digital Earth 2010年第1期3卷 47-71页

作者： William j.Morpheta jürgen Symanzik ATK Launch Systems Brigham CityUTUSA Department of Mathematics and Statistics Utah State UniversityLoganUTUSA

Vectors and periodic phenomena,*** versus time,have direction on a circular scale of 360°.An overview of existing methods for the display of circularspatial and vectorial-spatial data,such as arrow plots,is *** introduce the circular dataimage,a new type of graphic for the display of circular-spatial *** is defined by encoding direction in a spatial display by using colors from a color wheel constructed by connecting three or more two-color gradients with color continuity at the ***,image discontinuity from using a singlecolor gradient,***-red,does not ***-resolution global views of ocean wind direction are used as a running example throughout the *** and disadvantages of circular dataimages compared to arrow plots were obtained from a usability *** dataimages provide for simultaneous recognition of fine structure on a small-scale and large-scale structure on a global scale.

关键词： digital earth earth observation geo-spatial science geoinformatics visualization

Constraints on what controls millennial-scale basin-wide denudation across mountain belts, Asia

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Science China Earth Sciences 2025年第1期 74-93页

作者： Ye YANG Steven A.BINNIE Sheng XU Cong-Qiang LIU Tibor j.DUNAI Institute of Surface-Earth System Science School of Earth System Science Tianjin University Institute of Geology and Mineralogy University of Cologne

The terrestrial cosmogenic nuclide dataset consisting of 123310Be measurements of fluvial sediment samples across the Asian mountain belts is used to constrain the influence of climate,tectonics and topography on Earth-surface denudation processes.10Be-derived basin-wide denudation rates were recalculated using a Monte Carlo simulation approach that relied on pixel-by-pixel production *** rates derived span four orders of magnitude,from 7.4±0.7 mm kyr-1（1σ;Central Tibetan Plateau） to 9,646744+777mm kyr-1（1σ;Southern Tibetan Plateau）,with a median of 186 mm *** our results with the traditional basin-wide production rate scaling model using a centroid coordinate and mean elevation,suggests that 96.6%of production rates will be underestimated using the latter method,especially for basins with a large *** bias between both methods reaches as large as 40%,caused by basin hypsometry and the nonlinear scaling of production rate with elevation and *** of the correlations between uniformly recalculated denudation rates and tectonics,climate,topography and rock lithology will facilitate the extrapolation of denudation rates in unknown basins using available *** the perspective of local scales,precipitation coupled with neotectonics-driven landslides is likely the most influential factor in subtropical Taiwan Island,while topography primarily constrains surface denudation rates in the eastern Tibetan Plateau within a narrow range of *** highland regions with glacier coverage,such as the Pamir,central and southern Tibetan Plateau high denudation rates are affected by glaciation,whereas lower precipitation and high erosion base level may limit river incision and evolving relief in the Central Tibetan *** contrast to local-scale findings highlighting a dominant factor constraining denudation rate,our large-scale quantitative analyses across the Asian mountain belts finds that （1） topographic metrics including

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Large eddy simulation of turbulent diffusion flame combustion using a conserved scalar methodology

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航空动力学报 2007年第7期22卷 1106-1117页

作者： K. Wang Z. Yang j. j. McGuirk Department of Aeronautical and Automotive EngineeringLoughborough University Loughborough Leicestershire LE11 3TU UK

The present paper describes an LES prediction of turbulent diffusion flame combustion in a simplifled axi-symmetric combustor *** calculations are carried out using a well-tested finite volume incompressible LES code which has been modified to handle variable density and reacting *** basic mixture fraction conserved scalar method *** with the chemical state relationships described by fast *** turbulence-chemistry interaction is modelled by a sub-grid PDF method and the PDF is assumed to follow a Beta-function *** LES predictions have been time-averaged over 3.5 flow-through times to generate the mean radial profiles of mixture fraction,product mass fraction,temperature,axial velocity and axial *** agreement of the LES predictions with the experimental data is good for all the above quantities at four different axial positions with largest differences at the first measurement *** LES method also provides information on the unsteady nature of turbulent diffusion *** turbulent reacting flows with large density ratio,it was found necessary to use a relaxation method in order to remove unphysical high-frequency fluctuations and to maintain numerical stability.

关键词：大涡模拟湍流扩散数量方法论弛豫法燃烧理论

Design and Robust Performance Evaluation of a Fractional Order PID Controller Applied to a DC Motor

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IEEE/CAA journal of Automatica Sinica 2017年第2期4卷 304-314页

作者： j.Viola L.Angel j.M.Sebastian Universidad Pontificia Bolivariana Universidad Politecnica de Madrid Centre for Automation and Robotics (CAR) UPM-CSIC

This paper proposes a methodology for the quantitative robustness evaluation of PID controllers employed in a DC motor. The robustness analysis is performed employing a 2~3 factorial experimental design for a fractional order proportional integral and derivative controller(FOPID), integer order proportional integral and derivative controller(IOPID)and the Skogestad internal model control controller(SIMC). The factors assumed in experiment are the presence of random noise,external disturbances in the system input and variable load. As output variables, the experimental design employs the system step response and the controller action. Practical implementation of FOPID and IOPID controllers uses the MATLAB stateflow toolbox and a NI data acquisition system. Results of the robustness analysis show that the FOPID controller has a better performance and robust stability against the experiment factors.

关键词： Factorial experimental design fractional-order PID controller robustness analysis SIMC PID controller

Geochemical studies of hybrid granite from Madugulapalli area, Eastern Dharwar Craton, Southern India: Implications for crustal mixing

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Acta Geochimica 2023年第1期42卷 9-23页

作者： Nagamma j Ratnakar j Ajay kumar A Ashok Ch State Mines and Geology Department 508001 NalgondaIndia Department of Geology Osmania University500007 HyderabadIndia CSIR-National Geophysical Research Institute 500007 UppalHyderabadIndia

Magma produced by melting of continental crust and mantle at the Archean-Proterozoic boundary are compositionally variable and chemical compositions provide evidence for the mixing of two sources. Understanding the composition of hybrid magma is essential for determining the comparative infl uence of crust and mantle sources during orogenesis. The hybrid granites are less documented in Indian cratons, especially less in Dharwar Craton. Here we present petrographic and whole-rock geochemical data of Madgulapalli granitic rocks situated in the NE part of the Eastern Dharwar Craton(EDC), to elucidate their petrogenesis and role in crust formation. The Madugulapalli granites(MPG) are composed chiefl y of plagioclase, quartz, and alkali feldspar with associated biotite showing alteration and inter-granular textures. Geochemically, they are metaluminous to peraluminous in nature with calc-alkaline hybrid granite. The hybrid granites exhibit both negative and positive europium anomalies;the lower Rb/Sr, Rb, Sr, and higher Sr/Y,(Dy/Yb)N ratios suggest that the interaction of older rocks with residual garnet source melted at high pressures. We hypothesize that hybrid granites are formed by interaction(e.g., metasomatism, mingling, or mixing) between parental magmas and pre-existing rocks with the infl uence of sanukitoid melts(heat source) in a subduction environment. The genesis of the hybrid granites demonstrates the mixing coupled with diff erentiation in the petrogeny’s residue system in a syn-collision setting followed by continental crust stability in EDC during the Neoarchean period.

关键词： Madugulapalli granite Hybrid granite Crustal mixing Subduction

Synthesis and electronic properties of expanded 5-(hetero)arylthien-2-yl substituted 3-ethynyl quinoxalines with AIE characteristics

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Science China Chemistry 2018年第8期61卷 909-924页

作者： Franziska K.Merkt Thomas j.j.Müller Institute of Organic Chemistry and Macromolecular Chemistry Heinrich Heine University Düsseldorf

Expanded 5-(hetero)aryl-thien-2-yl substituted 3-ethynyl quinoxaline dyes with variable substitution pattern on the peripheral thiophene ring were synthesized in moderate to very good yields by Suzuki and Buchwald-Hartwig coupling of the corresponding brominated 3-ethynyl quinoxalines. Dumbbell-shaped bis(thienyl 3-ethynyl quinoxalines) are also accessible by the Suzuki protocol. The photophysical properties were investigated by UV and fluorescence spectroscopy. Most of the obtained compounds display fluorescence in solution and some of them also in the solid state. Additionally, tuning of the emission color of the quinoxaline based chromophores can be conveniently accomplished by the remote substituent group. The determined absorption and emission maximum as well as the Stokes shifts strongly correlate with Hammett σp+parameters. Besides,photophysical properties of selected derivatives in the solid state, biphasic solutions, and PMMA films, along with their relationships, are comparatively investigated. Moreover, two 5-(hetero)aryl-thien-2-yl substituted 3-ethynyl quinoxaline dyes are aggregation induced emission(AIE) chromophores indicated by restriction of molecular motions. A covalently restricted 3-ethynyl quinoxaline supports that the inhibition of molecular rotation is responsible for the significant enhancement of fluorescence in acetonitrile/water mixtures.

关键词： absorption aggregation induced emission cross-coupling fluorescence heterocycles palladium