Hughes has accomplished this in part by the unusual technique of double ghosting.
( Hughes ( ( has ( ( accomplished ( this ( in part ) ) ) ( by ( ( the ( unusual technique ) ) ( of ( double ghosting ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Hughes)) (VP (VBZ has) (VP (VBN accomplished) (NP (NP (DT this)) (PP (IN in) (NP (NN part)))) (PP (IN by) (NP (NP (DT the) (JJ unusual) (NN technique)) (PP (IN of) (NP (JJ double) (NN ghosting))))))) (. .)))
He could have just ghosted once.
( He ( ( could ( ( have just ) ( ghosted once ) ) ) . ) )
(ROOT (S (NP (PRP He)) (VP (MD could) (VP (VB have) (ADVP (RB just)) (VP (VBN ghosted) (ADVP (RB once))))) (. .)))