Journal Article Alzheimer’s disease BCI, Brain-computer-interface Brain-computer interface (BCI) CS, Covariate shift CSA, Covariate shift adaptation CSE, Covariate shift estimation CSE-UAEL, CSE-based unsupervised adaptive ensemble learning CSP, Common spatial pattern CSV, Covariate shift validation CSW, Covariate shift warning Covariate shift DWEC, Dynamically weighted ensemble classification EEG, Electroencephalography ERD, Synchronization ERS, Desynchronization EWMA, exponential weighted moving average Electroencephalogram (EEG) Ensemble learning FB, Frequency band FBCSP, Filter bank common spatial pattern KNN, K-nearest-neighbors LDA, Linear discriminant analysis MI, Motor imagery NSL, Non-stationary learning Non-stationary learning PCA, Principal component analysis PWKNN, Probabilistic weighted K-nearest neighbour RSM, Random subspace method SSL, Semi-supervised learning