Research areas

• My main line of research is in Combinatorial Scientific Computing (CSC). CSC is defined as

  "Development, application and analysis of combinatorial algorithms to enable scientific and engineering computations" 

  by others that work on the same area. See SIAM activity group ACDA, archives at the CSC-listserv, a SIAM News article by Alex Pothen and Bruce Hendrickson, and a blog on CSC (with Alex Pothen) for more information.

• I enjoy pondering on task scheduling and mapping problems as well.

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Recent projects

• MODS: Match and Order: Improving direct solvers for cardiac simulations (2023--2025).
• GABI: Greedy Algorithms for computing the Birkhoff decomposition (2024).
• PeachTree: An Inria Associated Team Project looking at combinatorial and scheduling problems in tensor computations (2022--2024).
• Homeland:PHC Procope Project with Christian Schulz of Heidelberg University, Germany. We work on graph and hypergraph clustering problems (2022--2024).

Previous projects

SOLHARIS: ANR funded project (ANR-19-CE46-0009) targeting strong and weak scalability with asynchronous task-based parallelism by the use of modern runtime systems.

PIKS: PHC Aurora Project looking at efficient parallel implementation of matching heuristics.

The project SOLHAR, funded by ANR, looked at solvers over run-time systems on modern parallel computers.

I participate in the MUMPS solver (MUltifrontal Massively Parallel Solvers for symmetric and unsymmetric complex/real sparse matrices).

I was involved in the project SOLSTICE, a major ANR funded project (ANR-06-CIS-010) looking at many aspects of the solution of large, sparse linear system of equations.

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Publications [Talks]

Most of the papers are available at HAL. Please drop a note if not there nor below.

2026

• Adil Chhabra, Christian Schulz, Bora Uçar, Loris Wilwert. Exact Minimum Cuts in Hypergraphs at Scale. SIAM Symposium on Algorithm Engineering and Experiments (ALENEX26), SIAM, Jan 2026, Vancouver (BC), Canada (hal-05243769).

2025

• Srinivas Aluru, Anne Benoit, Bora Uçar. Efficient and effective methods for variant selection. 16th ACM Conference on Bioinformatics, Computational Biology, and Health Informatics (BCB 2025), Oct 2025, Philadelphie, PA, United States (hal-05237949).
• Rob H. Bisseling, Bora Uçar. Optimal partitioning of 2D meshes for stencil computations. RR-9585, Inria Lyon. 2025 (hal-05006840v2).
• Deniz Elbek, Fatih Taşyaran, Bora Uçar, Kamer Kaya. SUperman: Efficient Permanent Computation on GPUs. RR-9578, Inria Lyon. 2025, pp.1-25 (hal-04985427).
• Henrik Reinstädtler, S M Ferdous, Alex Pothen, Bora Uçar, Christian Schulz. Semi-Streaming Algorithms for Hypergraph Matching. ESA 2025 - European Symposium on Algorithms, European Association for Theoretical Computer Science (EATCS), Sep 2025, Warsaw (POLAND), Poland (hal-04966763v3).
• Damien Lesens, Jérémy E. Cohen, Bora Uçar. Algorithms for symmetric Birkhoff-von Neumann decomposition of symmetric doubly stochastic matrices. RR-9566, Inria Lyon. 2025, pp.1-30 (hal-04877502v2).
• Somesh Singh, Bora Uçar. Efficient Parallel Sparse Tensor Contraction. IEEE Transactions on Parallel and Distributed Systems, 2025, 36 (6), pp.1206-1219 (hal-05047235).

2024

• Damien Lesens, Jérémy E. Cohen, Bora Uçar. Orthogonal matching pursuit-based algorithms for the Birkhoff-von Neumann decomposition. EUSIPCO 2024 - 24th European Signal Processing Conference, Aug 2024, Lyon, France. pp.12 (hal-04500014).
• Anne Benoit, Kamer Kaya, Bora Uçar. Connectivity of a random directed graph model. RR-9540, Inria Lyon. 2024 (hal-04428417v2)
• Henrik Reinstädtler, Christian Schulz, Bora Uçar. Engineering Edge Orientation Algorithms. ESA 2024 - 32nd Annual European Symposium on Algorithms, Schloss Dagstuhl – Leibniz-Zentrum für Informatik, Sep 2024, Egham, United Kingdom. pp.1-21 (hal-04555599).

2023

• Deepak Ajwani, Rob H. Bisseling, Katrin Casel , Umit V. Çatalyürek, Cédric Chevalier, Florian Chudigiewitsch, Marcelo Fonseca Faraj, Michael Fellows, Lars Gottesbüren, Tobias Heuer, George Karypis, Kamer Kaya, Jakub Lacki, Johannes Langguth, Xiaoye Sherry Li, Ruben Mayer, Johannes Meintrup, Yosuke Mizutani, François Pellegrini, Fabrizio Petrini, Frances Rosamond, Ilya Safro, Sebastian Schlag, Christian Schulz, Roohani Sharma, Darren Strash, Blair D. Sullivan, Bora Uçar, Albert-Jan Yzelman. Open Problems in (Hyper)Graph Decomposition. 2023. (hal-04251953).
• Ioannis Panagiotas, Grégoire Pichon, Somesh Singh, and Bora Uçar, Engineering fast algorithms for the bottleneck matching problem, to appear in the ESA 2023 - The 31st Annual European Symposium on Algorithms, Sep 2023, Amsterdam, The Netherlands. Local copy; see also the codes.

2022

• Jules Bertrand, Fanny Dufossé, Somesh Singh, and Bora Uçar, Algorithms and data structures for hyperedge queries, [Research Report] RR-9390, Inria Grenoble Rhône-Alpes. April 2022 (hal-03127673, earlier version dates April 2021).
• Christian Schulz and Bora Uçar (eds.),20th International Symposium on Experimental Algorithms (SEA 2022), July 25-27, 2022, Heidelberg, Germany. LIPIcs 233, Schloss Dagstuhl - Leibniz-Zentrum für Informatik 2022.
• Somesh Singh and Bora Uçar, An Efficient parallel implementation of a perfect hashing method for hypergraphs, to appear in the IPDPSW proceedings GrAPL 2022: Workshop on Graphs, Architectures, Programming, and Learning, Lyon, France. Local copy.
• Fanny Dufossé, Kamer Kaya, Ioannis Panagiotas, and Bora Uçar, Scaling matrices and counting the perfect matchings in graphs, Discrete Applied Mathematics, 308:130--146, 2022. Local copy.

2021

• Johannes Langguth, Ioannis Panagiotas, and Bora Uçar. Shared-memory implementation of the Karp-Sipser kernelization process. In HiPC 2021 - 28th edition of the IEEE International Conference on High Performance Computing, Data, and Analytics, pages 71–80, Bangalore, India, December 2021. Local copy.
• Eugenio Angriman, Henning Meyerhenke, Christian Schulz, and Bora Uçar, Fully-dynamic weighted matching approximation in practice, Available here and there.
• Fatih Taşyaran, Berkay Demireller, Kamer Kaya, and Bora Uçar, Streaming hypergraph partitioning algorithms on limited memory environments, in the proceedings of the 2020 International Conference on High Performance Computing & Simulation (HPCS 2020), Mar 2021 (Virtual). Local copy.

2020

• Filip Pawlowski, Rob Bisseling, Bora Uçar, Albert-Jan Yzelman, Combinatorial tiling for sparse neural networks, 2020 IEEE High Performance Extreme Computing (virtual conference), Sep 2020, Waltham, MA, United States (copy).
• Raluca Portase, Bora Uçar, Matrix symmetrization and sparse direct solvers, CSC 2020 - SIAM Workshop on Combinatorial Scientific Computing, Feb 2020, Seattle, United States, 2020 (copy).
• Kamer Kaya, Johannes Langguth, Ioannis Panagiotas, Bora Uçar, Karp-Sipser based kernels for bipartite graph matching, ALENEX20 - SIAM Symposium on Algorithm Engineering and Experiments, Jan 2020, Salt Lake City, Utah, United States (copy). See also codes.
• Eric Hein, Srinivas Eswar, Abdurrahman Yaşar, Jiajia Li, Jeffrey Young, Thomas Conte, Umit V. Çatalyürek, Rich Vuduc, Jason Riedy, and Bora Uçar, Programming strategies for irregular algorithms on the Emu Chick ACM Transactions on Parallel Computing, Association for Computing Machinery, 2020, 7 (4), pp.1-25. (copy).
• Ioannis Panagiotas and Bora Uçar, Engineering fast almost optimal algorithms for bipartite graph matching. ESA 2020 - European Symposium on Algorithms, Sep 2020, Pisa, Italy (copy). See also codes and the extended technical report below.
• Ioannis Panagiotas and Bora Uçar, Engineering fast almost optimal algorithms for bipartite graph matching: Extended version, [Research Report] RR-9321, Inria - Research Centre Grenoble – Rhône-Alpes, 2020. See also codes.

2019

• Bora Uçar, Partitioning, matching, and ordering: Combinatorial scientific computing with matrices and tensors, HDR thesis, ENS de Lyon, 2019. (available at HAL).
• Kamer Kaya, Johannes Langguth, Ioannis Panagiotas, and Bora Uçar, Karp-Sipser based kernels for bipartite graph matching. Accepted to be published in the proceedings of ALENEX20 (local copy).
• Raluca Portase and Bora Uçar, On matrix symmetrization and sparse direct solvers. Available as [Research Report] RR-8977, Inria Grenoble Rhône-Alpes, Revised version, July 2019.
• Julien Herrmann, M. Yusuf Özkaya, Bora Uçar, Kamer Kaya, Umit V. Çatalyürek, Multilevel algorithms for acyclic partitioning of directed acyclic graphs, SIAM Journal on Scientific Computing, 41 (2019), pp. A2117--A2145 (local copy) also available as [Research Report] RR-9163, Inria Grenoble Rhône-Alpes.
• Filip Pawłowski, Bora Uçar, and Albert-Jan Yzelman, A multi-dimensional Morton-ordered block storage for mode-oblivious tensor computations, Journal of Computational Science, 33 (2019), pp. 34--44. Available locally.
• Filip Pawłowski, Bora Uçar, and Albert-Jan Yzelman, High performance tensor--vector multiplication on shared memory systems, accepted to be published in the Proceedings of PPAM 2019. See also RR-9274.
• Jiajia Li, Bora Uçar, Umit V. Çatalyürek, Jimeng Sun, Kevin Barker, and Richard Vuduc, Efficient and effective sparse tensor reordering, in Proceedings of the ACM International Conference on Supercomputing (ICS'19), Phoenix, Arizona, 26--28 June 2019, pp. 227--237. Also available locally.
• Fanny Dufossé, Kamer Kaya, Ioannis Panagiotas, and Bora Uçar, Effective heuristics for matchings in hypergraphs, accepted to be published in Proceedings of SEA², June 24--29, Kalamata, Greece, 2019. Also available as [Research Report] RR-9224, Inria Grenoble Rhône-Alpes.
• M. Yusuf Özkaya, Anne Benoit, Bora Uçar, Julien Herrmann, and Umit V. Çatalyürek, A scalable clustering-based task scheduler for homogeneous processors using DAG partitioning, in Proceedings of the 33rd IEEE International Parallel and Distributed Processing Symposium (IPDPS 2019), Rio de Janeiro, Brazil, 20--24 May 2019, pp. 155--165. Also available locally.

2018

• Abdurrahman Yaşar, Bora Uçar, and Umit V. Çatalyürek, SiNA: A Scalable iterative network aligner, in Proc. 2018 IEEE/ACM International Conference on Advances in Social Networks Analysis and Mining (ASONAM), Barcelona, Spain, August 2018, pp. 111--118 (available locally).
• Fanny Dufossé, Kamer Kaya, Ioannis Panagiotas, and Bora Uçar, Approximation algorithms for maximum matchings in undirected graphs, in Proceedings of the SIAM Workshop on Combinatorial Scientific Computing 2018 (CSC18), Bergen, Norway, June 6–8, 2018, pp. 55--65. Also available locally.
• Enver Kayaaslan, Cevdet Aykanat, and Bora Uçar, 1.5D parallel sparse matrix-vector multiply, SIAM Journal on Scientific Computing, 40 (2018), C25--C46. Also available locally.
• Enver Kayaaslan, Thomas Lambert, Loris Marchal, and Uçar, Scheduling series-parallel task graphs to minimize peak memory, Theoretical Computer Science, 707 (2018), pp. 1--23. Also available locally.
• Oguz Kaya and Bora Uçar, Parallel Candecomp/Parafac decomposition of sparse tensors using dimension trees, SIAM Journal on Scientific Computing, 40 (2018), C99--C130. Also available locally.
• Fanny Dufossé, Kamer Kaya, Ioannis Panagiotas, and Bora Uçar, Further notes on Birkhoff--von Neumann decomposition of doubly stochastic matrices, Linear Algebra and its Applications, 554 (2018), pp. 68--78; also available as [Research Report] RR-9095, Inria Grenoble Rhône-Alpes, 2017.

2017

• Michele Benzi and Bora Uçar, Preconditioning techniques based on the Birkhoff--von Neumann decomposition, Computational Methods in Applied Mathematics, 17 (2017), pp. 201--215. Also available as [Research Report] RR-8914, Inria Grenoble Rhône-Alpes.
• Guillaume Aupy, Anne Benoit, Aurelian Cavelan, Massimiliano Fasi, Yves Robert, Hongyang Sun, and Bora Uçar; Coping with silent errors in HPC applications, Emergent Computation: A Festschrift for Selim G. Akl, Andy Adamatzky, Ed., Springer International Publishing, 2017, pp. 269--292.
• Julien Herrmann, Jonathan Kho, Bora Uçar, Kamer Kaya, and Umit V. Çatalyürek, Acyclic partitioning of large directed acyclic graphs, in the proceedings of the 17th IEEE/ACM International Symposium on Cluster, Cloud and Grid Computing, CCGRID 2017, Madrid, Spain, May 14–17, 2017, pp. 371–380.

2016

• Massimilinao Fasi, Julien Langou, Yves Robert, and Bora Uçar, A Backward/Forward recovery approach for the preconditioned conjugate gradient method, Journal of Computational Science, 17 (3), 2016, pp. 522--534 (doi).
• Fanny Dufossé and Bora Uçar, Notes on Birkhoff-von Neumann decomposition of doubly stochastic matrices, Linear Algebra and its Applications, vol. 497, 108-115 (doi)(also available as [Research Report] RR-8852, Inria Grenoble Rhône-Alpes, Feb. 2016.)

2015

• Oguz Kaya and Bora Uçar, High-performance parallel algorithms for the Tucker decomposition of higher order sparse tensors, Technical Report, Inria Grenoble Rhône-Alpes RR-8801, Nov. 2015.
• Fanny Dufossé, Kamer Kaya, and Bora Uçar, Two approximation algorithms for bipartite matching on multicore architectures, Journal of Parallel and Distributed Computing, Vol. 85, pp. 62--78, 2015 (abstract, copy, doi).
• Max Rietmann, Daniel Peter, Olaf Schenk, Bora Uçar, and Marcus Grote, Load-balanced local time stepping for large-scale wave propagation, in 29th IPDPS, Hyderabad, India, May 25–-29, 2015, pp. 925--935 (copy, doi).
• Mehmet Deveci, Kamer Kaya, Bora Uçar, and Umit V. Çatalyürek, Fast and high quality topology-aware task mapping, in 29th IPDPS, Hyderabad, India, May 25–-29, 2015, pp. 197--206 (copy, doi).
• Enver Kayaaslan, Bora Uçar, and Cevdet Aykanat, Semi-two-dimensional partitioning for parallel sparse matrix-vector multiplication, in PCO 2015, a workshop of the 29th IPDPS, Hyderabad, India, May 25–-29, 2015, pp. 1125--1134 (copy, doi).
• Massimilinao Fasi, Yves Robert, and Bora Uçar, Combining backward and forward recovery to cope with silent errors in iterative solvers, in PDSEC 2015, a workshop of the 29th IPDPS, Hyderabad, India, May 25–-29, 2015, pp. 980--989 (copy, doi). Supporting technical report RR-8675.
• Mehmet Deveci, Kamer Kaya, Bora Uçar, Umit V. Çatalyürek, Hypergraph partitioning for multiple communication cost metrics: Model and methods, Journal of Parallel and Distributed Computing, Vol. 77, pp. 69--83, 2015 (copy, doi).
• Thomas Lambert, Loris Marchal, and Bora Uçar, Comments on the hierarchically structured bin packing problem, Information Processing Letters, Vol. 115, pp. 306--309, 2015 (copy, doi).
• Oguz Kaya and Bora Uçar, Scalable sparse tensor decompositions in distributed memory systems, INRIA Research Report RR-8722, May 2015.

2014

• Enver Kayaaslan and Bora Uçar, Reducing elimination tree height for parallel LU factorization of sparse unsymmetric matrices, accepted to be published in the proceedings of HiPC2014, 21st Annual International Conference on High Performance Computing, to be held 17–20 December, 2014, Goa, India.
• Philip A. Knight, Daniel Ruiz and Bora Uçar, A symmetry preserving algorithm for matrix scaling, SIAM Journal on Matrix Analysis and Applications, Vol. 35, pp. 931--955, 2014. (abstract, doi). [See also codes].
• Fanny Dufossé, Kamer Kaya, and Bora Uçar, Bipartite matching heuristics with quality guarantees on shared memory parallel computers, in IPDPS 2014, May 19--23, 2014, Phoenix, Arizona, USA, pp. 540--549 (abs, copy [slightly updated], doi).
• Anne Benoit, Loris Marchal, Yves Robert, Bora Uçar, and Frédéric Vivien: Scheduling for Large-Scale Systems. Computing Handbook, 3rd ed., Ch. 59, 2014.
• Anaël Grandjean and Bora Uçar, On partitioning two dimensional finite difference meshes for distributed memory parallel computers, in the proceedings of PDP 2014: 22nd Euromicro International Conference on Parallel, Distributed and Network-Based Processing, 12–14 February, 2014, Turin, Italy, Marco Aldinucci, Daniele D’Agostino, and Peter Kilpatrick (Eds.), IEEE Computer Science, Conference Publishing Services, pp. 9--16, 2014. (local copy, and doi).

2013

• Umit V. Çatalyürek, Kamer Kaya, and Bora Uçar, On analysis of partitioning models and metrics in parallel sparse matrix-vector multiplication, INRIA Research Report RR-8301, May 2013.
• Kamer Kaya and Bora Uçar, Constructing elimination trees for sparse unsymmetric matrices, SIAM Journal on Matrix Analysis and Applications, Vol. 34, No. 2, pp. 345--354, 2013 (abstract, paper) [see the code uetree.c and the driver uetreemex.c. To compile: "mex uetreemex.c uetree.c -largeArrayDims''.]
• Kamer Kaya, Johannes Langguth, Fredrik Manne, and Bora Uçar, Push-relabel based algorithms for the maximum transversal problem, Computers and Operations Research, Vol. 40, No. 5, 1266--1275, 2013 (paper).
• Anne Benoit, Johannes Langguth, and Bora Uçar, Semi-matching algorithms for scheduling parallel tasks under resource constraints. INRIA Research report RR-8089, Version 3, January 2013. In Proceedings of PCO'2013, the 3rd Workshop on Parallel Computing and Optimization, in conjunction with IEEE IPDPS 2013, Boston, USA, May 2013.
• Ichitaro Yamazaki, Xiaoye Li, François-Henry Rouet, and Bora Uçar, On partitioning and reordering problems in a hierarchically parallel hybrid linear solver, To appear in Proceedings of PDSEC-13, The 14th IEEE International Workshop on Parallel and Distributed Scientific and Engineering Computing, in conjunction with IEEE IPDPS 2013, Boston, USA, May 2013. (paper, supporting technical report: Partitioning, ordering, and load balancing in a Hierarchically parallel hybrid linear solver)
• Oguz Kaya, Enver Kayaaslan, and Bora Uçar, On the minimum edge cover and vertex partition by quasi-cliques problems, INRIA Technical report, 2013.
• Mehmet Deveci, Kamer Kaya, Bora Uçar, Umit V. Çatalyürek, GPU accelerated maximum cardinality matching algorithms for bipartite graphs CoRR abs/1303.1379 (paper) (2013)

2012

• Kamer Kaya, Johannes Langguth, Fredrik Manne, and Bora Uçar, Investigations on push-relabel based algorithms for the maximum transversal problem, Technical report, INRIA RR-8093, October 2012 (paper. See also Computers & OR article in 2013 which uses some results from this paper).
• Anaël Grandjean, Johannes Langguth, and Bora Uçar, On Optimal and balanced sparse matrix partitioning problems, in proceedings of 2012 IEEE International Conference on Cluster Computing, CLUSTER, Beijing, China, September 24--28, 2012, pp. 257--265, 2012 (doi).
• Umit V. Çatalyürek, Kamer Kaya, and Bora Uçar, On shared-memory parallelization of a sparse matrix scaling algorithm, in proceedings of 41st International Conference on Parallel Processing, ICPP, Pittsburgh, USA, pp. 68--77, 2012 (doi, local copy).
• Umit V. Çatalyürek, Mehmet Deveci, Kamer Kaya, and Bora Uçar, UMPa: A Multi-objective, multi-level partitioner for communication minimization, accepted to be published in the proceedings of DIMACS Implementation Challenge 10, Graph Partitioning and Graph Clustering, held in Atlanta, GA, USA, February 13--14, 2012.
• Umit V. Çatalyürek, Kamer Kaya, Johannes Langguth, and Bora Uçar, A Divisive clustering technique for maximizing the modularity, accepted to be published in the proceedings of DIMACS Implementation Challenge 10, Graph Partitioning and Graph Clustering, held in Atlanta, GA, USA, February 13--14, 2012.
• Umit V. Çatalyürek, Mehmet Deveci, Kamer Kaya, and Bora Uçar, Multithreaded clustering for multi-level hypergraph partitioning, in proceedings of 26th IEEE International Parallel and Distributed Processing Symposium, IPDPS 2012, Shanghai, China, pp. 848--859, 2012 (abstract, paper, doi).
• Patrick R. Amestoy, Iain S. Duff, Jean-Yves L'Excellent, Yves Robert, François-Henry Rouet, and Bora Uçar, On computing inverse entries of a sparse matrix in an out-of-core environment, SIAM Journal on Scientific Computing, Vol. 34, No. 4, pp. A197--A1999, 2012. (abstract, doi)

2011

• Iain S. Duff, Kamer Kaya, and Bora Uçar, Design, analysis, and implementation of maximum transversal algorithms, ACM Transactions on Mathematical Software, Vol. 28, No. 2, pp. 13:1--13:31. December, 2011. (abstract, paper)
• Kamer Kaya, Johannes Langguth, Fredrik Manne, and Bora Uçar, Experiments on push-relabel-based maximum cardinality matching algorithms for bipartite graphs, Technical report, CERFACS TR/PA/11/33, April, 2011. (abstract, paper). [See also associated software Matchmaker].
• Madan Sathe, Olaf Schenk, Bora Uçar, and Ahmed Sameh, Towards a scalable hybrid linear solver based on combinatorial algorithms, Forthcoming in the book Combinatorial Scientific Computing, Naumann and Schenk (Eds.) (see book's page here).
• Kamer Kaya, François-Henry Rouet, and Bora Uçar, On partitioning problems with complex objectives, Technical report, INRIA RR-7546, February, 2011. (abstract, paper).
• Umit V. Çatalyürek, Bora Uçar, and Cevdet Aykanat, Hypergraph Partitioning, in Padua (ed.), Encyclopedia of Parallel Computing, Springer, pp. 871--881, 2011. (local copy and paper).
• Patrick Amestoy, Alfredo Buttari, Iain S. Duff, Abdou Guermouche, Jean-Yves L'Excellent, and Bora Uçar, Multifrontal Method , in Padua (ed.), Encyclopedia of Parallel Computing, Springer, pp. 1209--1216, 2011. (paper)
• Patrick Amestoy, Alfredo Buttari, Iain S. Duff, Abdou Guermouche, Jean-Yves L'Excellent, and Bora Uçar, Mumps , in Padua (ed.), Encyclopedia of Parallel Computing, Springer, pp. 1232--123, 2011. (paper)
• Eray Ozkural, Bora Uçar, and Cevdet Aykanat, Parallel frequent itemset mining with selective item replication, IEEE Transactions on Parallel and Distributed Systems, Vol. 22, pp. 1632--1640, 2011. (abstract, paper)
• Matthias Jacquelin, Loris Marchal, Yves Robert, and Bora Uçar, On optimal tree traversals for sparse matrix factorization, In proceedings of IPDPS 2011, 25th IEEE International Symposium on Parallel and Distributed Processing, Anchorage, Alaska, USA, pp. 556--567, 2011. (abstract, paper).
• Umit V. Çatalyürek, Kamer Kaya, and Bora Uçar, Integrated data placement and task assignment for scientific workflows in Clouds, In p
  roceedings of DIDC'11, Proceedings of the fourth international workshop on Data-intensive distributed computing, pp. 45--54, 2011. (abstract, paper).
• Thomas Ropars, Amina Guermouche, Bora Uçar, Esteban Meneses, Laxmikant V. Kalé, and Franck Cappello, On the use of cluster-based partial message logging to improve fault tolerance for MPI HPC applications , In E. Jeannot, R. Namyst, and J. Roman, editors, Proceedings of Euro-Par 2011: 17th International Conference on Parallel Processing, pp. 567--578, 2011. (abstract, paper).

2010

• Iain S. Duff and Bora Uçar, On the block triangular form of symmetric matrices, SIAM Review, Vol. 52, pp. 455--470, 2010. (abstract, paper)
• Umit V. Çatalyürek, Cevdet Aykanat, and Bora Uçar, On two-dimensional sparse matrix partitioning: Models, methods, and a recipe, SIAM Journal on Scientific Computing, Vol. 32, pp. 656--683, 2010. (abstract, paper)
• Bora Uçar, Umit V. Çatalyürek, and Cevdet Aykanat, A matrix partitioning interface to PaToH in MATLAB, Parallel Computing, Vol. 36, pp. 254--272, 2010 (doi) (abstract, paper)
• Bora Uçar and Umit V. Çatalyürek, On the scalability of hypergraph models for sparse matrix partitioning, In M. Danelutto, J. Bourgeois, and T. Gross, editors, Proceedings of PDP 2010: 18th Euromicro International Conference on Parallel, Distributed and Network-Based Computing, pp. 593--600, 2010. (abstract, paper)

2009

• Iain S. Duff and Bora Uçar, Combinatorial problems in solving linear systems, (abstract, LIP research report RR-2009-15; also available as CERFACS technical report TR/PA/09/60)
• Kamer Kaya and Bora Uçar, Exact algorithms for a task assignment problem, Parallel Processing Letters, Vol. 19, pp. 451--465, 2009 (abstract, also available as LIP research report RR-2009-14)[see also Task Intreaction Graph Data Set]

2008

• Patrick R. Amestoy, Iain S. Duff, Daniel Ruiz, and Bora Uçar, A parallel matrix scaling algorithm, LNCS 5336, pp.301--313, 2008. (Proceedings of VECPAR'08-International Meeting-High Performance Computing for Computational Science, Jun'08). (abstract, paper)
• Cevdet Aykanat, Berkant Barla Cambazoglu, and Bora Uçar, Multi-level direct K-way hypergraph partitioning with multiple constraints and fixed vertices, Journal of Parallel and Distributed Computing, Vol. 68, pp. 609--625, 2008. (abstract, paper)
• Bora Uçar, Heuristics for a matrix symmetrization problem, LNCS 4967, pp.717--727, 2008. (Proceedings of Parallel Processing and Applied Mathematics (PPAM'07), Sep'07). (abstract, paper)
• Kamer Kaya, Bora Uçar, and Cevdet Aykanat, Adapting iterative-improvement heuristics for scheduling file-sharing tasks on heterogeneous platforms, in F. Xhafa and A. Abraham (eds.), Metaheuristics for Scheduling in Distributed Computing Environments, Chapter 5, pp.121--151. Studies in Computational Intelligence, Springer-Verlag Berlin Heidelberg, 2008. (abstract)

2007

• Michele Benzi and Bora Uçar, Block triangular preconditioners for M-matrices and Markov chains, ETNA (Electronic Transactions on Numerical Analysis), Vol. 26, pp.209--227, 2007 (abstract, paper)
• Kamer Kaya, Bora Uçar, and Cevdet Aykanat, Heuristics for scheduling file-sharing tasks on heterogeneous systems with distributed repositories, Journal of Parallel and Distributed Computing, Vol. 67, No. 3, pp.271--285, 2007. (abstract, paper)
• Bora Uçar and Cevdet Aykanat, Partitioning sparse matrices for parallel preconditioned iterative methods, SIAM Journal on Scientific Computing, Vol. 29, pp.1683--1709, 2007. (abstract, paper)
• Bora Uçar and Cevdet Aykanat, Revisiting hypergraph models for sparse matrix partitioning, SIAM Review, Vol. 49, No. 4, pp.595--603, 2007. (abstract, paper)
• Bora Uçar, Cevdet Aykanat, Mustafa C. Pinar, and Tahir Malas, Parallel image restoration using surrogate constraint methods, Journal of Parallel and Distributed Computing, Vol. 67, No. 2, pp.186--204, 2007. (abstract, paper)

2006

• Michele Benzi and Bora Uçar, Product preconditioning for Markov chain problems, Proceedings of the 2006 Markov Anniversary Meeting (Charleston, SC, 12-14 June 2006), Boson Books, Raleigh, NC, 2006, pp. 239--256 (abstract, paper) Recipient of the Best Paper Award.
• Bora Uçar, Cevdet Aykanat, Kamer Kaya, and Murat Ikinci, Task assignment in heterogeneous computing systems, Journal of Parallel and Distributed Computing, Vol. 66, No. 1, pp.32--46, 2006. (abstract, paper) [see also Task Intreaction Graph Data Set]
• Masha Sosonkina, Bora Uçar, and Yousef Saad, Hypergraph partitioning for parallel iterative solution of general sparse linear systems, Technical report 2006/231, Minnesota Supercomputing Institute, Minneapolis, MN 55455, 2006. (abstract)

2005

• Bora Uçar, Parallel sparse matrix-vector multiplies and iterative solvers, PhD thesis, Bilkent University, Department of Computer Engineering, Sep 2005. (abstract)

2004

• Bora Uçar and Cevdet Aykanat, Encapsulating multiple communication cost metrics in partitioning sparse rectangular matrices for parallel matrix vector multiplies, SIAM Journal on Scientific Computing, Vol. 25, No. 6, pp.1837--1859, 2004. (abstract, paper)
• Bora Uçar and Cevdet Aykanat, A message ordering problem in parallel programs, LNCS, Vol. 3241, pp.131--138, 2004. (Proceedings of 11th European PVM/MPI Users' Group Meeting, Budapest, Hungary). (abstract, paper)

2003

• Bora Uçar and Cevdet Aykanat, ParMxvLib: A parallel library for sparse-matrix vector multiplies, in Proceedings of 7th World Multiconference on Systemics, Cybernetics and Informatics (SCI2003), Orlando, Florida, USA, July 2003, pp.393--398. (abstract, tech-rep)
• Bora Uçar and Cevdet Aykanat, Minimizing communication cost in fine grain partitioning of sparse matrices, LNCS 2869, pp.926--933, 2003. (Proceedings of 18th International Symposium on Computers and Information Sciences, Antalya, Turkey). (abstract, paper)

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Selected talks [Publications]

• A sparse matrix scaling algorithm and its efficient parallelization, HPCSE 2013, High Performance Computing in Science and Engineering, Hotel Soláň, May 27--30, 2013, Czech Republic (.pdf).
• Paralel sparse matrix vector multiplication and models for efficient parallelization, lecture notes for a course at the Parallel Computing Group at the University of Murcia, Spain, November 28--29, 2011 (.pdf).
• Patrick R. Amestoy, Iain S. Duff, Daniel Ruiz, and Bora Uçar, Towards parallel bipartite matching algorithms (revised version of the one below). Presentation at Scheduling for large scale systems, 13--15 May, 2009, Knoxville, USA (.pdf).
• Patrick R. Amestoy, Iain S. Duff, Daniel Ruiz, and Bora Uçar, Computing a class of bipartite matchings in parallel (revised version is above). Presentation at SIAM PP08, 12--14 March, 2008, Atlanta, USA (.pdf).
• Bora Uçar and Cevdet Aykanat, Partitioning sparse matrices for parallel preconditioned iterative methods. Presentation at Copper Mountain Conference on Iterative Methods 2006, April 2 - April 7, 2006, Copper Mountain, Colorado, USA (.pdf). Posted online in July 2013.