init previous values with 0
init previous values with 0

ktnyt/chainer,hvy/chainer,ktnyt/chainer,kashif/chainer,chainer/chainer,anaruse/chainer,chainer/chainer,niboshi/chainer,okuta/chainer,keisuke-umezawa/chainer,wkentaro/chainer,hvy/chainer,okuta/chainer,tkerola/chainer,okuta/chainer,keisuke-umezawa/chainer,niboshi/chainer,aonotas/chainer,pfnet/chainer,jnishi/chainer,wkentaro/chainer,keisuke-umezawa/chainer,keisuke-umezawa/chainer,rezoo/chainer,hvy/chainer,wkentaro/chainer,ktnyt/chainer,wkentaro/chainer,chainer/chainer,chainer/chainer,ktnyt/chainer,hvy/chainer,niboshi/chainer,okuta/chainer,niboshi/chainer,jnishi/chainer,ronekko/chainer,jnishi/chainer,jnishi/chainer