(6)  α = arg min  α   t r ( ( V  K   - ∑  m = 1  M    α  m   v   W  m    )   T   ( ( V  K   - ∑  m = 1  M    α  m   v   W  m    )   )      + λ t r ( F  T   ( I - ∑  m = 1  M    α  m   W  m    )   T   ( I - ∑  m = 1  M    α  m   W  m    )  F  )    + λ t r ( ( F - Y ˜   )   T   H ( F - Y ˜   )   )    s . t .   α  m   ≥ 0 , 1 ≤ m ≤ M