  In this paper we show that for a Koszul Calabi-Yau algebra, there is a
shifted bi-symplectic structure in the sense of
Crawley-Boevey-Etingof-Ginzburg, on the cobar construction of its co-unitalized
Koszul dual coalgebra, and hence its DG representation schemes, in the sense of
Berest-Khachatryan-Ramadoss, have a shifted symplectic structure in the sense
of Pantev-To\"en-Vaqui\'e-Vezzosi.
