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Non-asymptotic Error Bound for Optimal Prediction of Function-on-Function Regression by RKHS Approach

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Acta Mathematica Sinica,English Series 2022年第4期38卷 777-796页

作者： Hong zhi TOng Ling Fang HU Michael ng School of Statistics University of International Business and EconomicsBeijing 100029P.R.China Department of Mathematics Hong Kong Baptist UniversityKowloon TongHong KongP.R.China Department of Mathematics The University of Hong KongPokfulamHong KongP.R.China

In this paper,we study and analyze the regularized least squares for function-on-function regression *** our model,both the predictors(input data)and responses(output data)are multivariate functions(with d variables andd variables respectively),and the model coefficient lies in a reproducing kernel Hilbert space(RKHS).We show under mild condition on the reproducing kernel and input data statistics that the convergence rate of excess prediction risk by the regularized least squares is minimax *** examples based on medical image analysis and atmospheric point spread function estimation are considered and tested,and the results demonstrate that the performance of the proposed model is comparable with that of other testing methods.

关键词： Regularized least squares function-on-function regression non-asymptotic error bound reproducing kernel Hilbert space integral operator

A Frisch-Newton Algorithm for Sparse Quantile Regression

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Acta Mathematicae Applicatae Sinica 2005年第2期21卷 225-236页

作者： Roger Koenker Pin ng Department of Economics University of Illinois at Urbana-Champaign IL 61820 USACollege of Business Administration Northern Arizona University 70 McConnell Dr P.O. Box 15066 FlagstaffAZ 86011-5066. USA.

Recent experience has shown that interior-point methods using a log barrierapproach are far superior to classical simplex methods for computing solutions to large parametricquantile regression problems. In many large empirical applications, the design matrix has a verysparse structure. A typical example is the classical fixed-effect model for panel data where theparametric dimension of the model can be quite large, but the number of non-zero elements is quitesmall. Adopting recent developments in sparse linear algebra we introduce a modified version of theFrisch-Newton algorithm for quantile regression described in Portnoy and Koenker[28]. The newalgorithm substantially reduces the storage (memory) requirements and increases computational *** modified algorithm also facilitates the development of nonparametric quantile regressionmethods. The pseudo design matrices employed in nonparametric quantile regression smoothing areinherently sparse in both the fidelity and roughness penalty components. Exploiting the sparsestructure of these problems opens up a whole range of new possibilities for multivariate smoothingon large data sets via ANOVA-type decomposition and partial linear models.

关键词： Quantile regression interior-point algorithm sparse linear algebra

Three-dimensional numerical analysis of plant-soil hydraulic interactions on pore water pressure of vegetated slope under different rainfall patterns

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第9期16卷 3696-3706页

作者： Haowen Guo Charles Wang Wai ng Qi zh.ng Department of Civil and Environmental Engineering The Hong Kong University of Science and TechnologyHong KongChina

Understanding the pore water pressure distribution in unsaturated soil is crucial in predicting shallow landslides triggered by rainfall,mainly when dealing with different temporal patterns of rainfall ***,the hydrological response of vegetated slopes,especially three-dimensional(3D)slopes covered with shrubs,under different rainfall patterns remains unclear and requires further *** address this issue,this study adopts a novel 3D numerical model for simulating hydraulic interactions between the root system of the shrub and the surrounding *** series of numerical parametric studies are conducted to investigate the influences of slope inclination,rainfall pattern and rainfall *** rainfall patterns(advanced,bimodal,delayed,and uniform)and two rainfall durations(4-h intense and 168-h mild rainfall)are considered to study the hydrological response of the *** computed results show that 17%higher transpiration-induced suction is found for a steeper slope,which remains even after a short,intense rainfall with a 100-year return *** extreme rainfalls with advanced(PA),bimodal(PB)and uniform(PU)rainfall patterns need to be considered for the short rainfall duration(4 h),while the delayed(PD)and uniform(PU)rainfall patterns are highly recommended for long rainfall durations(168 h).The presence of plants can improve slope stability markedly under extreme rainfall with a short duration(4 h).For the long duration(168 h),the benefit of the plant in preserving pore-water pressure(PWP)and slope stability may not be sufficient.

关键词： Root-soil interactions Rainfall patterns Slope stability Three-dimensional(3D)

Study of the attenuation relationship for the Wenchuan M_s 8.0 earthquake

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Earthquake Engineering and Engineering Vibration 2015年第1期14卷 1-11页

作者： Sin-Chi Kuok Iok-Tong ng Ka-Veng Yuen Faculty of Science and Technology University of Macao

Prediction of peak ground acceleration is an essential element in engineering seismology and it has received great attention in last few decades. In this paper, a comprehensive database of the strong-motion records of the 2008 great Wenchuan Ms 8.0 earthquake is analyzed to investigate the seismic attenuation relationship and the directivity effects. In contrast to most existing seismic attenuation models, the proposed model considers explicitly the directivity effect which has primary influence on the magnitude of ground motion. Bayesian model updating is used to obtain the model parameters and the associated uncertainty. Comparative study is performed with the well-known Boore-Joyner-Fumal empirical formula. Results show that consideration of the directivity effect is vital in modeling the seismic attenuation relationship.

关键词： Bayesian inference Boore-Joyner-Fumal attenuation relationship directivity peak ground acceleration seismic attenuation model

Ground state energy of He isoelectronic sequence treated variationally via Hylleraas-like wavefunction

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Chinese Physics B 2009年第6期18卷 2238-2243页

作者： Serpil Sakiroglu Kadir Akgngr Ismail Skmen Physics Department Dokuz Eyll University

In this study, the energy for the ground state of helium and a few helium-like ions （Z=1-6） is computed variationally by using a Hylleraas-like wavefunction. A four-parameters wavefunction, satisfying boundary conditions for coalescence points, is combined with a Hylleraas-like basis set which explicitly incorporates r12 interelectronic distance. The main contribution of this work is the introduction of modified correlation terms leading to the definition of integral transforms which provide the calculation of expectation value of energy to be done analytically over single-particle coordinates instead of Hylleraas coordinates.

关键词： He isoelectronic sequence Hylleraas basis set electronic correlation variational method

Remote sensing-based estimation of rice yields using various models:A critical review

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Geo-Spatial Information Science 2021年第4期24卷 580-603页

作者： Daniel Marc G dela Torre Jay Gao Cate Macinnis-ng School of Environment University of AucklandAucklandNew Zealand School of Biological Sciences University of AucklandAucklandNew Zealand

Reliable estimation of region-wide rice yield is vital for food security and agricultural ***-scale models have increased our understanding of rice yield and its estimation under theoretical environmental ***,they offer little infor-mation on spatial variability effects on farm-scale *** Sensing(RS)is a useful tool to upscale yield estimates from farm scales to regional *** research used RS with rice models for reliable yield *** several countries start to operatio-nalize rice monitoring systems,it is needed to synthesize current literature to identify knowledge gaps,to improve estimation accuracies,and to optimize *** paper critically reviewed significant developments in using geospatial methods,imagery,and quantitative models to estimate rice ***,essential characteristics of rice were discussed as detected by optical and radar sensors,band selection,sensor configuration,spatial resolution,mapping methods,and biophysical variables of rice derivable from RS ***,various empirical,process-based,and semi-empirical models that used RS data for spatial estimation of yield were critically assessed-discussing how major types of models,RS platforms,data assimilation algorithms,canopy state variables,and RS variables can be integrated for yield ***,to overcome current constraints and to improve accuracies,several possibilities were suggested-adding new modeling modules,using alternative canopy variables,and adopting novel modeling *** rice yields are expected to decrease due to global warming,geospatial rice yield estimation techniques are indispensable tools for climate change *** studies should focus on resolving the current limitations of estimation by precise delineation of rice cultivars,by incorporating dynamic harvesting indices based on climatic drivers,using innovative modeling approaches with machine learning.

关键词： Process-based crop model data assimilation empirical model geospatial applications remote sensing rice yield mapping yield estimation

The RNA Pol Ⅱ sub-complex hsRpb4/7 is required for viability of multiple human cell lines

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Protein & Cell 2012年第11期3卷 846-854页

作者： Yang zhao Kim K.C.Li King Pan ng Chi Ho ng Kevin A.W.Lee Division of Life Science The Hong Kong University of Science and TechnologySai KungHong Kong S.A.R.China

The evolutionarily conserved RNA Polymerase Ⅱ Rpb4/7 sub-complex has been thoroughly studied in yeast and impacts gene expression at multiple levels including transcription,mRNA processing and *** addition Rpb4/7 exerts differential effects on gene expression in yeast and Rpb4 is not obligatory for yeast(***)*** roles for human(hs)Rpb4/7 have not been extensively described and we have probed this question by depleting hsRpb4/7 in established human cell lines using RNA *** find that Rpb4/7 protein levels are inter-dependent and accordingly,the functional effects of depleting either protein are ***4/7 exhibits gene-specific effects and cells initially remain viable upon hsRpb4/7 *** prolonged hsRpb4/7 depletion is cytotoxic in the range of cell lines *** cell death occurs by an unknown mechanism and in some cases is accompanied by a pronounced elongated cell *** conclusion we provide evidence for a gene-specific role of hsRpb4/7 in human cell viability.

关键词： RNA PolymeraseⅡ hsRpb4/7 sub-complex gene expression cell viability cell shape

Involvement of apoptosis of alveolar epithelial cells in acute pancreatitis-associated lung injury

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World Journal of Gastroenterology 2000年第6期6卷 920-924页

作者： Yuan YZ Gong zh Lou KX Tu SP zhai ZK Xu JY Shanghai Med Univ 2 Ruijin Hosp Dept Gastroenterol Shanghai 200025 Peoples R China

INTRODUCTIONAcute pancreatitis in a common and potentially fataldisease which is associated with considerablemorbidity and a mortality rate of approximately30%;its pathogenesis remains *** of death is often due to mul... 详细信息

关键词： pancreatitis lung/injuries apoptosis protein P53 immunohistochemistry platelet activating factor

Heterogeneous numerical modelling for the auto thermal reforming of crude glycerol in a fixed bed reactor

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Chinese Journal of Chemical Engineering 2022年第2期35卷 261-268页

作者： Jason Williams Hussameldin Ibrahim Nima Karimi Kelvin Tsun Wai ng Clean Energy Technologies Research Institute Process Systems EngineeringFaculty of Engineering and Applied ScienceUniversity of ReginaRegina SK S4S 0A2Canada Environmental Systems Engineering Faculty of Engineering and Applied ScienceUniversity of ReginaRegina SK S4S 0A2Canada

A mathematical model for the catalytic autothermal reforming(ATR)reaction of synthetic crude glycerol to hydrogen in a fixed bed tubular reactor(FBTR)and over an in-house developed metal oxide catalyst is presented in this *** heterogeneous model equations account for a two-phase system of solid catalyst and bulk feed ***,the ATR of crude glycerol reaction scheme and intrinsic kinetic rate model over an active,selective,and stable nickel-based catalyst were integrated in the developed ***,the model was validated using experimental data generated in our labs for the ATR of synthetic crude *** modelling results adequately described the detailed gas product composition and distribution,temperature profiles,and conversion propagation in the axial direction of the fixed bed reactor over a wide range of reaction temperature(773–923 K)and mass-time(12.71–158.23 g cat·min·(mol C)^(-1)).The crude glycerol conversion predicted with the model showing a close resemblance to those obtained experimentally with an average absolute deviation(AAD)of less than 8%.The maximum crude glycerol conversion and hydrogen yield were found to be 92%and 3 mol hydrogen/mol crude glycerol,***,the gas product concentration profile in the reactor was adequately described(90%)accuracy with a hydrogen concentration of 39%(volume).

关键词： Hydrogen crude glycerol Autothermal reforming Numerical analysis Fixed-bed reactor