2022
Network-adaptive robust penalized estimation of time-varying coefficient models with longitudinal data
Fang K, Fan X, Ma S, Zhang Q. Network-adaptive robust penalized estimation of time-varying coefficient models with longitudinal data. Journal Of Statistical Computation And Simulation 2022, 92: 3045-3065. DOI: 10.1080/00949655.2022.2055758.Peer-Reviewed Original ResearchTime-varying coefficient modelsLikelihood-based estimationPenalization approachCoefficient modelStatistical modelPractical problemsNovel penaltyConsistency propertiesPractical performanceLoss functionNumerical studyLongitudinal dataEstimationNetwork structureNetwork connectivityConnection measuresModelData analysisRobustnessSimulationsInterconnectionProblemCovariatesField
2021
Promote sign consistency in the joint estimation of precision matrices
Zhang Q, Ma S, Huang Y. Promote sign consistency in the joint estimation of precision matrices. Computational Statistics & Data Analysis 2021, 159: 107210. DOI: 10.1016/j.csda.2021.107210.Peer-Reviewed Original ResearchMultiple precision matricesPrecision matrixRegularization methodJoint estimationGroup parametersSign consistencyConsistency propertiesGaussian graphical modelsNovel regularization methodHigh-dimensional dataRandom variablesSparsity structureData examplesMore interpretable resultsNatural interpretationConditional independenceInterpretable resultsGraphical modelsPractical examplesEstimationConflicting signsPopular toolMatrixParametersFull flexibility
2019
Penalized Relative Error Estimation of a Partially Functional Linear Multiplicative Model
Zhang T, Huang Y, Zhang Q, Ma S, Ahmed S. Penalized Relative Error Estimation of a Partially Functional Linear Multiplicative Model. Contributions To Statistics 2019, 127-144. DOI: 10.1007/978-3-030-17519-1_10.Peer-Reviewed Original ResearchFinite sample performanceRelative error estimationTecator dataScalar responseLinear multiplicative modelsScalar variablesSample performanceFunctional predictorsError estimationBasis functionsMultiplicative modelConsistency propertiesLeast squaresLoss functionTrue structureRelative errorClassic methodsEstimationPenalizationModelFunctional dataSquaresSimulations