@Article{BRS95,
  author = 	 { Margrit Betke and Ronald L. Rivest and Mona Singh },
  title = 	 { Piecemeal Learning of an Unknown Environment },
  journal = 	 { Machine Learning },
  publisher =    { Kluwer },                  
  issn =         { 0885-6125 },
  OPTyear = 	 { 1995 },
  OPTmonth = 	 { February },
  date =         { 1995-02 },                  
  volume = 	 { 18 },
  number = 	 { 2 },
  pages = 	 { 231--254 },
  url =          { http://dx.doi.org/10.1007/BF00993411 },
  doi =          { 10.1007/BF00993411 },
  keywords =     { map learning, graph algorithms, robot navigation },                  
  abstract =     { 
        We introduce a new learning problem: learning a graph by \emph{piecemeal search},
        in which the learner must return every so often to its starting point (for refueling,
        say).  We present two linear-time piecemeal-search algorithms for learning
        \emph{city-block graphs}: grid graphs with rectangular obstacles.
                 },
}