Patric R. J. Östergård

Pekka H. J. Lampio, Ferenc Szöllösi, Patric R. J. Östergård: The quaternary complex Hadamard matrices of orders 10, 12, and 14. Discrete Mathematics 313(2): 189-206 (2013)

Mohammadreza Jooyandeh, Brendan D. McKay, Patric R. J. Östergård, Ville Pettersson, Carol T. Zamfirescu: Planar Hypohamiltonian Graphs on 40 Vertices. CoRR abs/1302.2698 (2013)

Petteri Kaski, Mahdad Khatirinejad, Patric R. J. Östergård: Steiner triple systems satisfying the 4-vertex condition. Des. Codes Cryptography 62(3): 323-330 (2012)

Patric R. J. Östergård: Switching codes and designs. Discrete Mathematics 312(3): 621-632 (2012)

Majid Behbahani, Clement W. H. Lam, Patric R. J. Östergård: On triple systems and strongly regular graphs. J. Comb. Theory, Ser. A 119(7): 1414-1426 (2012)

Samu Alanko, Simon Crevals, Anton Isopoussu, Patric R. J. Östergård, Ville Pettersson: Computing the Domination Number of Grid Graphs. Electr. J. Comb. 18(1) (2011)

Patric R. J. Östergård, Olli Pottonen: Two optimal one-error-correcting codes of length 13 that are not doubly shortened perfect codes. Des. Codes Cryptography 59(1-3): 281-285 (2011)

Charles J. Colbourn, Petteri Kaski, Patric R. J. Östergård, David A. Pike, Olli Pottonen: Nearly Kirkman triple systems of order 18 and Hanani triple systems of order 19. Discrete Mathematics 311(10-11): 827-834 (2011)

Petteri Kaski, Veli Mäkinen, Patric R. J. Östergård: The Cycle Switching Graph of the Steiner Triple Systems of Order 19 is Connected. Graphs and Combinatorics 27(4): 539-546 (2011)

Alexander Hulpke, Petteri Kaski, Patric R. J. Östergård: The number of Latin squares of order 11. Math. Comput. 80(274): 1197-1219 (2011)

Patric R. J. Östergård, Vesa P. Vaskelainen: Russian doll search for the Steiner triple covering problem. Optimization Letters 5(4): 631-638 (2011)

Denis S. Krotov, Patric R. J. Östergård, Olli Pottonen: On Optimal Binary One-Error-Correcting Codes of Lengths 2^m-4 and 2^m-3. IEEE Transactions on Information Theory 57(10): 6771-6779 (2011)

Patric R. J. Östergård: On the Size of Optimal Three-Error-Correcting Binary Codes of Length 16. IEEE Transactions on Information Theory 57(10): 6824-6826 (2011)

Denis S. Krotov, Patric R. J. Östergård, Olli Pottonen: On Optimal Binary One-Error-Correcting Codes of Lengths $2^m-4$ and $2^m-3$. CoRR abs/1104.4013 (2011)

Charles J. Colbourn, Anthony D. Forbes, Mike J. Grannell, Terry S. Griggs, Petteri Kaski, Patric R. J. Östergård, David A. Pike, Olli Pottonen: Properties of the Steiner Triple Systems of Order 19. Electr. J. Comb. 17(1) (2010)

Patric R. J. Östergård, Vesa P. Vaskelainen: A tournament of order 14 with disjoint Banks and Slater sets. Discrete Applied Mathematics 158(5): 588-591 (2010)

Alexander A. Davydov, Patric R. J. Östergård: Linear codes with covering radius 3. Des. Codes Cryptography 54(3): 253-271 (2010)

Patric R. J. Östergård, Olli Pottonen, Kevin T. Phelps: The perfect binary one-error-correcting codes of length 15: part II-properties. IEEE Transactions on Information Theory 56(6): 2571-2582 (2010)

Patric R. J. Östergård: Classification of binary constant weight codes. IEEE Transactions on Information Theory 56(8): 3779-3785 (2010)

Andries E. Brouwer, Patric R. J. Östergård: Classification of the (0, 2)-graphs of valency 8. Discrete Mathematics 309(3): 532-547 (2009)

Ivan Yu. Mogilnykh, Patric R. J. Östergård, Olli Pottonen, Faina I. Solov'eva: Reconstructing extended perfect binary one-error-correcting codes from their minimum distance graphs. IEEE Transactions on Information Theory 55(6): 2622-2625 (2009)

Patric R. J. Östergård, Olli Pottonen: The perfect binary one-error-correcting codes of length 15: part I-classification. IEEE Transactions on Information Theory 55(10): 4657-4660 (2009)

Patric R. J. Östergård, Olli Pottonen, Kevin T. Phelps: The Perfect Binary One-Error-Correcting Codes of Length 15: Part II--Properties. CoRR abs/0903.2749 (2009)

Patric R. J. Östergård, Olli Pottonen: Two Optimal One-Error-Correcting Codes of Length 13 That Are Not Doubly Shortened Perfect Codes. CoRR abs/0909.2526 (2009)

Gerzson Kéri, Patric R. J. Östergård: On the minimum size of binary codes with length 2 R + 4 and covering radius R. Des. Codes Cryptography 48(2): 165-169 (2008)

Petteri Kaski, Patric R. J. Östergård, Svetlana Topalova, Rosen Zlatarski: Steiner triple systems of order 19 and 21 with subsystems of order 7. Discrete Mathematics 308(13): 2732-2741 (2008)

Harri Haanpää, Patric R. J. Östergård, Sándor Szabó: Small P-Groups with Full-Rank Factorization. IJAC 18(6): 1019-1034 (2008)

Patric R. J. Östergård, Olli Pottonen: There exists no Steiner system S(4, 5, 17). J. Comb. Theory, Ser. A 115(8): 1570-1573 (2008)

Patric R. J. Östergård: P.G. Szabó, M.C. Markót, T. Csendes, E. Specht, L.G. Casado, I. García, New Approaches to Circle Packing in a Square, Springer, Berlin, 2007, ISBN: 978-0-387-45673-7, pp 238. Oper. Res. Lett. 36(2): 277-278 (2008)

Patric R. J. Östergård, Olli Pottonen: The Perfect Binary One-Error-Correcting Codes of Length 15: Part I--Classification. CoRR abs/0806.2513 (2008)

Ivan Yu. Mogilnykh, Patric R. J. Östergård, Olli Pottonen, Faina I. Solov'eva: Reconstructing Extended Perfect Binary One-Error-Correcting Codes from Their Minimum Distance Graphs. CoRR abs/0810.5633 (2008)

Gerzson Kéri, Patric R. J. Östergård: Further results on the covering radius of small codes. Discrete Mathematics 307(1): 69-77 (2007)

Patric R. J. Östergård, Sándor Szabó: Elementary P-Groups with the RÉdei Property. IJAC 17(1): 171-178 (2007)

Lasse Kiviluoto, Patric R. J. Östergård: New Uniquely Decodable Codes for the T-User Binary Adder Channel With 3<=T<=5. IEEE Transactions on Information Theory 53(3): 1219-1220 (2007)

Stefka Bouyuklieva, Patric R. J. Östergård: New constructions of optimal self-dual binary codes of length 54. Des. Codes Cryptography 41(1): 101-109 (2006)

Patric R. J. Östergård, Petteri Kaski: There are exactly five biplanes with k=11. Electronic Notes in Discrete Mathematics 27: 75 (2006)

Petteri Kaski, Patric R. J. Östergård, Olli Pottonen: The Steiner quadruple systems of order 16. J. Comb. Theory, Ser. A 113(8): 1764-1770 (2006)

Patric R. J. Östergård, Esa Antero Seuranen: Unidirectional covering codes. IEEE Transactions on Information Theory 52(1): 336-340 (2006)

Petteri Kaski, Patric R. J. Östergård: One-Factorizations of Regular Graphs of Order 12. Electr. J. Comb. 12 (2005)

Patric R. J. Östergård, Jörn Quistorff, Alfred Wassermann: New Results on Codes with Covering Radius 1 and Minimum Distance 2. Des. Codes Cryptography 35(2): 241-250 (2005)

Patric R. J. Östergård: Two New Four-Error-Correcting Binary Codes. Des. Codes Cryptography 36(3): 327-329 (2005)

Gerzson Kéri, Patric R. J. Östergård: Bounds for Covering Codes over Large Alphabets. Des. Codes Cryptography 37(1): 45-60 (2005)

T. Aaron Gulliver, Masaaki Harada, Takuji Nishimura, Patric R. J. Östergård: Near-Extremal Formally Self-Dual Even Codes of Lengths 24 and 32. Des. Codes Cryptography 37(3): 465-471 (2005)

Iliya Bouyukliev, Patric R. J. Östergård: Classification of Self-Orthogonal Codes over F₃ and F₄. SIAM J. Discrete Math. 19(2): 363-370 (2005)

M. Mattas, Patric R. J. Östergård: A New Bound for the Zero-Error Capacity Region of the Two-User Binary Adder Channel. IEEE Transactions on Information Theory 51(9): 3289-3291 (2005)

Patric R. J. Östergård: Constructing combinatorial objects via cliques. Surveys in Combinatorics 2005: 57-82

Harri Haanpää, Antti Huima, Patric R. J. Östergård: Sets in Z _nwith distinct sums of pairs. Discrete Applied Mathematics 138(1-2): 99-106 (2004)

Petteri Kaski, Patric R. J. Östergård: Enumeration of balanced ternary designs. Discrete Applied Mathematics 138(1-2): 133-141 (2004)

Petteri Kaski, Patric R. J. Östergård: Miscellaneous classification results for 2-designs. Discrete Mathematics 280(1-3): 65-75 (2004)

T. Aaron Gulliver, Patric R. J. Östergård: Binary optimal linear rate 1/2 codes. Discrete Mathematics 283(1-3): 255-261 (2004)

Patric R. J. Östergård: On a hypercube coloring problem. J. Comb. Theory, Ser. A 108(2): 199-204 (2004)

Petteri Kaski, Patric R. J. Östergård: The Steiner triple systems of order 19. Math. Comput. 73(248): 2075-2092 (2004)

Patric R. J. Östergård, Alexander Vardy: Resolving the Existence of Full-Rank Tilings of Binary Hamming Spaces. SIAM J. Discrete Math. 18(2): 382-387 (2004)

Patric R. J. Östergård: There exists no Hermitian self-dual quaternary [26, 13, 10]/sub 4/ code. IEEE Transactions on Information Theory 50(12): 3316-3317 (2004)

Patric R. J. Östergård: Binary Two-Error-Correcting Codes are Better than Quaternary. Appl. Algebra Eng. Commun. Comput. 14(2): 89-96 (2003)

Harri Haanpää, Patric R. J. Östergård: Classification of whist tournaments with up to 12 players. Discrete Applied Mathematics 129(2-3): 399-407 (2003)

Dameng Deng, Malcolm Greig, Patric R. J. Östergård: More c-Bhaskar Rao designs with small block size. Discrete Mathematics 261(1-3): 189-208 (2003)

T. Aaron Gulliver, Patric R. J. Östergård, Nikolai Senkevitch: Optimal linear rate 1/2 codes over F₅ and F₂. Discrete Mathematics 265(1-3): 59-70 (2003)

Masaaki Harada, Patric R. J. Östergård: On the Classification of Self-Dual Codes over F₅. Graphs and Combinatorics 19(2): 203-214 (2003)

Franco Di Pasquale, Patric R. J. Östergård: An improved upper bound for the football pool problem for nine matches. J. Comb. Theory, Ser. A 102(1): 204-206 (2003)

Patric R. J. Östergård: Disproof of a conjecture on the existence of balanced optimal covering codes. IEEE Transactions on Information Theory 49(2): 487-488 (2003)

T. Aaron Gulliver, Patric R. J. Östergård, Nikolai Senkevitch: Optimal quaternary linear rate-1/2 codes of length <18. IEEE Transactions on Information Theory 49(6): 1540-1543 (2003)

Patric R. J. Östergård, Mattias Svanström: Ternary Constant Weight Codes. Electr. J. Comb. 9(1) (2002)

Patric R. J. Östergård: A fast algorithm for the maximum clique problem. Discrete Applied Mathematics 120(1-3): 197-207 (2002)

Patric R. J. Östergård, Petteri Kaski: Enumeration of 2-(9, 3, lambda) Designs and Their Resolutions. Des. Codes Cryptography 27(1-2): 131-137 (2002)

Patric R. J. Östergård: A 2-(22, 8, 4) Design Cannot Have a 2-(10, 4, 4) Subdesign. Des. Codes Cryptography 27(3): 257-260 (2002)

Patric R. J. Östergård: Classifying Subspaces of Hamming Spaces. Des. Codes Cryptography 27(3): 297-305 (2002)

Masaaki Harada, Patric R. J. Östergård: Self-dual and maximal self-orthogonal codes over F₇. Discrete Mathematics 256(1-2): 471-477 (2002)

Masaaki Harada, Patric R. J. Östergård: Classification of Extremal Formally Self-Dual Even Codes of Length 22. Graphs and Combinatorics 18(3): 507-516 (2002)

Patric R. J. Östergård, Alfred Wassermann: A New Lower Bound for the Football Pool Problem for Six Matches. J. Comb. Theory, Ser. A 99(1): 175-179 (2002)

Mattias Svanström, Patric R. J. Östergård, Galina T. Bogdanova: Bounds and constructions for ternary constant-composition codes. IEEE Transactions on Information Theory 48(1): 101-111 (2002)

Patric R. J. Östergård, William D. Weakley: Values of Domination Numbers of the Queen's Graph. Electr. J. Comb. 8(1) (2001)

Galina T. Bogdanova, Andries E. Brouwer, Stoyan N. Kapralov, Patric R. J. Östergård: Error-Correcting Codes over an Alphabet of Four Elements. Des. Codes Cryptography 23(3): 333-342 (2001)

Galina T. Bogdanova, Patric R. J. Östergård: Bounds on codes over an alphabet of five elements. Discrete Mathematics 240(1-3): 13-19 (2001)

T. Aaron Gulliver, Patric R. J. Östergård: Improved Bounds for Ternary Linear Codes of Dimension 8 Using Tabu Search. J. Heuristics 7(1): 37-46 (2001)

Patric R. J. Östergård: A New Algorithm for the Maximum-Weight Clique Problem. Nord. J. Comput. 8(4): 424-436 (2001)

Alexander A. Davydov, Patric R. J. Östergård: Linear codes with covering radius R = 2, 3 and codimension tR. IEEE Transactions on Information Theory 47(1): 416-421 (2001)

Patric R. J. Östergård, Uri Blass: On the size of optimal binary codes of length 9 and covering radius 1. IEEE Transactions on Information Theory 47(6): 2556-2557 (2001)

T. Aaron Gulliver, Patric R. J. Östergård: New Binary Linear Codes. Ars Comb. 56 (2000)

Patric R. J. Östergård: Classification of binary/ternary one-error-correcting codes. Discrete Mathematics 223(1-3): 253-262 (2000)

Alexander A. Davydov, Patric R. J. Östergård: On Saturating Sets in Small Projective Geometries. Eur. J. Comb. 21(5): 563-570 (2000)

Patric R. J. Östergård: New Constructions for q-ary Covering Codes. Ars Comb. 52 (1999)

Kari J. Nurmela, Patric R. J. Östergård: Covering t-sets with (t+2)-sets. Discrete Applied Mathematics 95(1-3): 425-437 (1999)

Alexander A. Davydov, Patric R. J. Östergård: New Linear Codes with Covering Radius 2 and Odd Basis. Des. Codes Cryptography 16(1): 29-39 (1999)

Patric R. J. Östergård, William D. Weakley: Constructing Covering Codes with Given Automorphisms. Des. Codes Cryptography 16(1): 65-73 (1999)

Kari J. Nurmela, Patric R. J. Östergård: More Optimal Packings of Equal Circles in a Square. Discrete & Computational Geometry 22(3): 439-457 (1999)

Patric R. J. Östergård: A New Algorithm for the Maximum-Weight Clique Problem. Electronic Notes in Discrete Mathematics 3: 153-156 (1999)

Patric R. J. Östergård, Tsonka Stefanova Baicheva, Emil Kolev: Optimal Binary One-Error-Correcting Codes of Length 10 Have 72 Codewords. IEEE Transactions on Information Theory 45(4): 1229-1231 (1999)

Patric R. J. Östergård: On Binary/Ternary Error-Correcting Codes with Minimum Distance 4. AAECC 1999: 472-481

T. Aaron Gulliver, Patric R. J. Östergård: Improved Bounds for Quaternary Linear Codes of Dimension 6. Appl. Algebra Eng. Commun. Comput. 9(2): 153-159 (1998)

Patric R. J. Östergård, Markku K. Kaikkonen: New upper bounds for binary covering codes. Discrete Mathematics 178(1-3): 165-179 (1998)

Patric R. J. Östergård: On the structure of optimal error-correcting codes. Discrete Mathematics 179(1-3): 285-287 (1998)

Ronald L. Graham, Boris D. Lubachevsky, Kari J. Nurmela, Patric R. J. Östergård: Dense packings of congruent circles in a circle. Discrete Mathematics 181(1-3): 139-154 (1998)

Andries E. Brouwer, Heikki O. Hämäläinen, Patric R. J. Östergård, Neil J. A. Sloane: Bounds on Mixed Binary/Ternary Codes. IEEE Transactions on Information Theory 44(1): 140-161 (1998)

Tuvi Etzion, Patric R. J. Östergård: Greedy and Heuristic Algorithms for Codes and Colorings. IEEE Transactions on Information Theory 44(1): 382-388 (1998)

Patric R. J. Östergård, Heikki O. Hämäläinen: A New Table of Binary/Ternary Mixed Covering Codes. Des. Codes Cryptography 11(2): 151-178 (1997)

Kari J. Nurmela, Patric R. J. Östergård: Packing up to 50 Equal Circles in a Square. Discrete & Computational Geometry 18(1): 111-120 (1997)

Patric R. J. Östergård: A Coloring Problem in Hamming Spaces. Eur. J. Comb. 18(3): 303-309 (1997)

John C. Cock, Patric R. J. Östergård: Ternary Covering Codes Derived from BCH Codes. J. Comb. Theory, Ser. A 80(2): 283-289 (1997)

T. Aaron Gulliver, Patric R. J. Östergård: Improved bounds for ternary linear codes of dimension 7. IEEE Transactions on Information Theory 43(4): 1377-1381 (1997)

Kari J. Nurmela, Markku K. Kaikkonen, Patric R. J. Östergård: New constant weight codes from linear permutation groups. IEEE Transactions on Information Theory 43(5): 1623-1630 (1997)

Patric R. J. Östergård: A Combinatorial Proof for the Football Pool Problem for Six Matches. J. Comb. Theory, Ser. A 76(1): 160-163 (1996)

Patric R. J. Östergård, Markku K. Kaikkonen: New single-error-correcting codes. IEEE Transactions on Information Theory 42(4): 1261-1262 (1996)

Heikki O. Hämäläinen, Iiro S. Honkala, Simon Litsyn, Patric R. J. Östergård: Bounds for Binary Codes That Are Multiple Coverings of the Farthest-Off Points. SIAM J. Discrete Math. 8(2): 196-207 (1995)

Patric R. J. Östergård: New Upper Bounds for the Football Pool Problem for 11 and 12 Matches. J. Comb. Theory, Ser. A 67(2): 161-168 (1994)

Patric R. J. Östergård: Further results on (k, t)-subnormal covering codes. IEEE Transactions on Information Theory 38(1): 206-210 (1992)

Patric R. J. Östergård: A new binary code of length 10 and covering radius 1. IEEE Transactions on Information Theory 37(1): 179-180 (1991)

Patric R. J. Östergård: Upper bounds for q-ary covering codes. IEEE Transactions on Information Theory 37(3): 660-664 (1991)

Patric R. J. Östergård: Correction to 'Upper Bounds for q-ary Covering Codes'. IEEE Transactions on Information Theory 37(6): 1738- (1991)