The mathematical procedure of minor embedding is used to "reshape" a user's QUBO or Ising problem onto the Chimera graph of the D-Wave QPU. D-Wave's embedding algorithm, published in 2013 by Cai & Macready & Roy, is effective, but reseachers have questioned its efficiency. Prasanna Date, of RPI, developed an embedding algorithm which ran faster, and also used fewer qubits.