Ioannis Koutis, Publications   

• A nearly-m*logn solver for SDD linear systems  [arxiv]
  (with Gary Miller, Richard Peng) 
  FOCS 2011

• Combinatorial preconditioners and multilevel solvers
  for problems in computer vision and image processing [PDF]
  (with Gary Miller, David Tolliver) 
  Computer Vision and Image Understanding 2011  (invited)
  ISVC 2009  Conference Version: [PDF] 
  

• Near linear-work parallel SDD solvers, 
  low-diameter decomposition and low-stretch subgraphs [PDF]
  (with Guy Blelloch, Anupam Gupta, Gary Miller, Richard Peng, Kanat Tangwongsan) 
  SPAA 2011 

• Spectral counting of triangles in power-law networks
  via element-wise sparsification and triangle-based link recommendation  [PDF]
  (with Charalambos Tsourakakis, Petros Drineas, Eirinaios Michelakis, Christos Faloutsos)
  Social Network Analysis and Mining
  ASONAM 2009    Conference Version: [PDF]

• Approaching optimality for solving SDD systems [arxiv]
  (with Gary Miller, Richard Peng)
  FOCS 2010

• Hierarchical Diagonal Blocking with precision reduction applied to combinatorial multigrid [PDF]
  (with Guy E. Blelloch, Gary Miller, Kanat Tangwongsan)
  SC10

• Limits and applications of group algebras for parameterized problems [PDF]
  (with Ryan Williams)
  ICALP 2009
  

• Faster algebraic algorithms for path and packing problems [PDF]
  ICALP 2008

• Graph partitioning into isolated, high conductance clusters:
  theory, computation and applications to preconditioning [PDF]
  (with Gary Miller)
  SPAA 2008

• Unassisted Segmentation of Multiple Retinal Layers via Spectral Rounding [PDF]
  (with David Tolliver, Hiroshi Ishikawa, Joel Shuman, Gary Miller)
  ARVO 2008

• Combinatorial and algebraic tools for optimal multilevel algorithms [PDF]
  PhD Thesis, CMU-CS-07-131

• A linear work O(n^1/6) time algorithm for solving planar Laplacians [PDF]
  (with Gary Miller)
  SODA 2007

• Parameterized complexity and improved inapproximability
  for computing the largest j-simplex in a V-polytope [PDF]
  Information Processing Letters 2006

• Dimensionality restrictions on sums over Z_p^d [PDF]
  Technical Report CMU-CS-07-103
  
  These results were published in a shlightly stronger form in:
  ''On the number of subsequences with given sum of sequences over finite Abelian $p$-groups'',
  by Weidong Gao and Alfred Geroldinger , Rocky Mountain J. Mathematics, 2007 [pdf]

• A faster parameterized algorithm for set packing [PDF]
  Information Processing Letters 2005

• On the hardness of approximate multivariate integration [PDF]
  APPROX 2003

• Parallel computation of matrix pseudospectra: a case for load balancing [PDF]
  (with Costas Bekas, Efstratios Gallopoulos, Efi Kokiopoulou)
  ICS 2001
  

• Spectrum through pseudospectrum [arxiv]
  
  This informal publication discusses the computation of matrix eigenvalues via a descent-through-pseudospectra approach. It represents joint work with E. Gallopoulos, which was presented at FOCM 1999, and at the 5th IMACS conference on iterative methods ( abstract )
  
  
• Exclusion regions and fast estimation of pseudospectra [pdf]
  
  This work was presented in an invited talk at the 2003 SIAM annual meeting