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seen Sep 26 '12 at 18:03

Sep
26
awarded  Scholar
Sep
26
accepted Covering a $d$-dimensional integer lattice by repeating a minimal set of deterministic moves
Sep
25
revised Covering a $d$-dimensional integer lattice by repeating a minimal set of deterministic moves
added 760 characters in body
Sep
25
comment Covering a $d$-dimensional integer lattice by repeating a minimal set of deterministic moves
It might have been better to call the turtle a robot. It simply executes a set of programmed moves over and over again until it covers the lattice.
Sep
25
comment Covering a $d$-dimensional integer lattice by repeating a minimal set of deterministic moves
@Joseph O'Rourke, Sorry, I should have been much clearer with the problem specification. The idea is that you have total information about the grid, control over where the turtle is placed, and the ability to program the turtle. The challenge is to minimize the length of the loop that governs its motions on the lattice while still insuring coverage under the constraint that no vertex can be re-visited.
Sep
25
comment Covering a $d$-dimensional integer lattice by repeating a minimal set of deterministic moves
@Sergei Ivanov, Please see the note I've added to the question. No instruction is allowed to direct the turtle off of the grid prior to coverage.
Sep
25
revised Covering a $d$-dimensional integer lattice by repeating a minimal set of deterministic moves
added 145 characters in body
Sep
25
asked Covering a $d$-dimensional integer lattice by repeating a minimal set of deterministic moves
Sep
24
comment Collisions between rooks taking random flights on an $N$ by $M$ chessboard
@Joseph O'Rourke, thanks for recalculating the means for the $8x8$ and $4x4$ board!
Sep
24
comment Collisions between rooks taking random flights on an $N$ by $M$ chessboard
@Joseph O'Rourke, as a word of explanation for my original choice of [2], I was imagining that whatever was moving the rook wouldn't have global information about the rook's position on the board. To make an extremely tenuous connection, I thought of this question after reading a paper on how (GPS tracked) albatrosses' execute Lévy flights while engaging in foraging behavior: (pnas.org/content/early/2012/04/18/1121201109.abstract)
Sep
24
comment Collisions between rooks taking random flights on an $N$ by $M$ chessboard
@Joseph O'Rourke, Thanks for running these simulations! But could you clarify your statement that the rook can move off the board, and that this is counted as a move? And are you following the original suggestion in [2] that the rook's direction is randomly chosen?
Sep
24
revised Collisions between rooks taking random flights on an $N$ by $M$ chessboard
added 350 characters in body
Sep
24
revised Collisions between rooks taking random flights on an $N$ by $M$ chessboard
added 406 characters in body
Sep
23
revised Collisions between rooks taking random flights on an $N$ by $M$ chessboard
added 259 characters in body
Sep
23
comment Collisions between rooks taking random flights on an $N$ by $M$ chessboard
@Per Alexandersson, Absolutely you're right. But I posted the question here because I would be really interested if there are any techniques for tackling this problem in lieu of simulations.
Sep
23
asked Collisions between rooks taking random flights on an $N$ by $M$ chessboard
Sep
17
awarded  Supporter
Sep
17
awarded  Editor
Sep
17
awarded  Student
Sep
16
comment A discrete random walk that avoids previously visited vertices for an exponentially distributed time interval
@Vincent Beffara, I agree with what you say. I'm certainly seeing long-term diffusive behavior for values of $p$ ranging from $p = 0.01$ to $0.99$. Also, and I didn't properly specify this, I'm allowing for an unblocking event, with non-zero probability in the same time interval that a site is blocked, so we are guaranteed reversals.