2012
Sparse principal component analysis by choice of norm
Qi X, Luo R, Zhao H. Sparse principal component analysis by choice of norm. Journal Of Multivariate Analysis 2012, 114: 127-160. PMID: 23524453, PMCID: PMC3601508, DOI: 10.1016/j.jmva.2012.07.004.Peer-Reviewed Original ResearchHigh-dimensional situationsSparse principal component analysisReal gene expression dataEfficient iterative algorithmHigh-dimensional dataSparse principal component analysis methodEigenvalue problemOptimization problemIterative methodChoice of normDimensional situationTheoretical resultsTraditional eigenvalue problemIterative algorithmStrict convexityLinear combinationSingle-component modelExpensive computationSparse linear combinationDimensional dataUsual normExistence of correlationsGene expression dataPractical applicationsCompetitive results
2010
Asymptotic efficiency and finite-sample properties of the generalized profiling estimation of parameters in ordinary differential equations
Qi X, Zhao H. Asymptotic efficiency and finite-sample properties of the generalized profiling estimation of parameters in ordinary differential equations. The Annals Of Statistics 2010, 38: 435-481. DOI: 10.1214/09-aos724.Peer-Reviewed Original ResearchOrdinary differential equationsDifferential equationsBasis functionsEstimation procedureAsymptotic covariance matrixEfficient estimation procedureFinite sample propertiesMaximum likelihood estimationODE solutionStatistical propertiesAsymptotic normalityAsymptotic efficiencySpline approximationTrue solutionCovariance matrixComputational efficiencyLikelihood estimationLinear combinationUniform normApproximationEstimation methodEquationsObserved dataDynamic behaviorSolution