Manifestly T-Duality Symmetric Matrix Models
  We present a new class of matrix models which are manifestly symmetric under the T-duality transformation of the target space. The models may serve as a nonperturbative regularization for the T-duality symmetry in continuum string theory. In particular, it now becomes possible to extract winding modes explicitly in terms of extended matrix variables. 
Tsunehide Kuroki, Yuji Okawa, Fumihiko Sugino and Tamiaki Yoneya