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## Umar, Abdullahi

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 Author ID: umar.abdullahi Published as: Umar, A.; Umar, Abdullahi Homepage: http://www.ku.ac.ae/pages/abdullahi-umar External Links: MGP · Wikidata
 Documents Indexed: 33 Publications since 1992
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#### Co-Authors

 14 single-authored 11 Laradji, Abdallah 3 Al-Kharousi, Fatma Ahmed 2 Kehinde, R. 2 Maltcev, Victor 1 Ali, Bashir 1 Alsharawi, Ziyad 1 Burstein, Alexander 1 Cain, Alan J. 1 Deadman, M. 1 Kudryavtseva, Ganna 1 Makanjuola, S. O.
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#### Serials

 7 Communications in Algebra 5 Semigroup Forum 2 Portugaliae Mathematica 2 Proceedings of the Royal Society of Edinburgh. Section A. Mathematics 2 Journal of Difference Equations and Applications 2 Journal of Integer Sequences 2 Algebra and Discrete Mathematics 1 Discrete Mathematics 1 Acta Scientiarum Mathematicarum 1 Ars Combinatoria 1 Czechoslovak Mathematical Journal 1 Journal of Algebra 1 Utilitas Mathematica 1 Southeast Asian Bulletin of Mathematics 1 International Journal of Algebra and Computation 1 The Australasian Journal of Combinatorics
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#### Fields

 31 Group theory and generalizations (20-XX) 19 Combinatorics (05-XX) 2 Order, lattices, ordered algebraic structures (06-XX) 1 Number theory (11-XX) 1 General topology (54-XX) 1 Numerical analysis (65-XX) 1 Biology and other natural sciences (92-XX)

#### Citations contained in zbMATH

23 Publications have been cited 100 times in 67 Documents Cited by Year
On the semigroups of order-decreasing finite full transformations. Zbl 0746.20048
Umar, Abdullahi
1992
Combinatorial results for semigroups of order-preserving full transformations. Zbl 1098.20049
2006
Combinatorial results for semigroups of order-preserving partial transformations. Zbl 1057.20046
2004
On certain finite semigroups of order-decreasing transformations. I. Zbl 1072.20080
2004
Semigroups of order-decreasing transformations: The isomorphism theorem. Zbl 0858.20056
Umar, Abdullahi
1996
On the semigroups of partial one-to-one order-decreasing finite transformations. Zbl 0789.20075
Umar, Abdullahi
1993
On the semigroup of partial isometries of a finite chain. Zbl 1339.20058
Al-Kharousi, F.; Kehinde, R.; Umar, A.
2016
On the number of nilpotents in the partial symmetric semigroup. Zbl 1069.20061
2004
On a certain subsemigroup of the bicyclic semigroup. Zbl 0869.20042
Makanjuola, S. O.; Umar, A.
1997
Combinatorial results for certain semigroups of partial isometries of a finite chain. Zbl 1296.05203
Al-Kharousi, F.; Kehinde, R.; Umar, A.
2014
Combinatorial results for the symmetric inverse semigroup. Zbl 1131.20049
2007
On certain infinite semigroups of order-decreasing transformations. I. Zbl 0883.20026
Umar, Abdullahi
1997
On the ranks of certain finite semigroups of order-decreasing transformations. Zbl 0844.20050
Umar, Abdullahi
1996
A class of quasi-adequate transformation semigroups. Zbl 0828.20066
Umar, Abdullahi
1994
A countable family of finitely presented infinite congruence-free monoids. Zbl 1363.20044
Al-Kharousi, Fatma; Cain, Alan J.; Maltcev, Victor; Umar, Abdullahi
2015
Combinatorial results for semigroups of order-decreasing partial transformations. Zbl 1064.05016
2004
Some remarks about Fibonacci groups and semigroups. Zbl 0904.20021
Umar, Abdullahi
1997
Presentations for subsemigroups of $$PD_n$$. Zbl 07088794
Umar, Abdullahi
2019
Presentation for the partial dual symmetric inverse monoid. Zbl 1322.20052
Kudryavtseva, Ganna; Maltcev, Victor; Umar, Abdullahi
2015
The solution of a recursive sequence arising from a combinatorial problem in botanical epidemiology. Zbl 1274.92048
AlSharawi, Z.; Burstein, A.; Deadman, M.; Umar, A.
2013
Combinatorial results for semigroups of orientation-preserving partial transformations. Zbl 1226.20052
Umar, A.
2011
Asymptotic results for semigroups of order-preserving partial transformations. Zbl 1087.20043
2006
Enumeration of certain finite semigroups of transformations. Zbl 0956.20052
Umar, Abdullahi
1998
Presentations for subsemigroups of $$PD_n$$. Zbl 07088794
Umar, Abdullahi
2019
On the semigroup of partial isometries of a finite chain. Zbl 1339.20058
Al-Kharousi, F.; Kehinde, R.; Umar, A.
2016
A countable family of finitely presented infinite congruence-free monoids. Zbl 1363.20044
Al-Kharousi, Fatma; Cain, Alan J.; Maltcev, Victor; Umar, Abdullahi
2015
Presentation for the partial dual symmetric inverse monoid. Zbl 1322.20052
Kudryavtseva, Ganna; Maltcev, Victor; Umar, Abdullahi
2015
Combinatorial results for certain semigroups of partial isometries of a finite chain. Zbl 1296.05203
Al-Kharousi, F.; Kehinde, R.; Umar, A.
2014
The solution of a recursive sequence arising from a combinatorial problem in botanical epidemiology. Zbl 1274.92048
AlSharawi, Z.; Burstein, A.; Deadman, M.; Umar, A.
2013
Combinatorial results for semigroups of orientation-preserving partial transformations. Zbl 1226.20052
Umar, A.
2011
Combinatorial results for the symmetric inverse semigroup. Zbl 1131.20049
2007
Combinatorial results for semigroups of order-preserving full transformations. Zbl 1098.20049
2006
Asymptotic results for semigroups of order-preserving partial transformations. Zbl 1087.20043
2006
Combinatorial results for semigroups of order-preserving partial transformations. Zbl 1057.20046
2004
On certain finite semigroups of order-decreasing transformations. I. Zbl 1072.20080
2004
On the number of nilpotents in the partial symmetric semigroup. Zbl 1069.20061
2004
Combinatorial results for semigroups of order-decreasing partial transformations. Zbl 1064.05016
2004
Enumeration of certain finite semigroups of transformations. Zbl 0956.20052
Umar, Abdullahi
1998
On a certain subsemigroup of the bicyclic semigroup. Zbl 0869.20042
Makanjuola, S. O.; Umar, A.
1997
On certain infinite semigroups of order-decreasing transformations. I. Zbl 0883.20026
Umar, Abdullahi
1997
Some remarks about Fibonacci groups and semigroups. Zbl 0904.20021
Umar, Abdullahi
1997
Semigroups of order-decreasing transformations: The isomorphism theorem. Zbl 0858.20056
Umar, Abdullahi
1996
On the ranks of certain finite semigroups of order-decreasing transformations. Zbl 0844.20050
Umar, Abdullahi
1996
A class of quasi-adequate transformation semigroups. Zbl 0828.20066
Umar, Abdullahi
1994
On the semigroups of partial one-to-one order-decreasing finite transformations. Zbl 0789.20075
Umar, Abdullahi
1993
On the semigroups of order-decreasing finite full transformations. Zbl 0746.20048
Umar, Abdullahi
1992
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#### Cited by 74 Authors

 9 Umar, Abdullahi 5 Sun, Lei 4 Fernandes, Vítor H. 4 Laradji, Abdallah 4 Yağci, Melek 4 Yang, Xiuliang 3 Araújo, João 3 Ayik, Hayrullah 3 Billhardt, Bernd 3 Descalço, L. 3 Maltcev, Victor 3 Ruškuc, Nik 3 Sanwong, Jintana 3 Sommanee, Worachead 3 Wang, Limin 3 Yang, Haobo 3 Zhao, Ping 2 Bugay, Leyla 2 Dimitrova, Ilinka 2 Garba, Goje Uba 2 Higgins, Peter Michael 2 Imam, Abdussamad Tanko 2 Jitjankarn, Phichet 2 Kim, V. I. 2 Konieczny, Janusz 2 Koppitz, Jörg 2 Korkmaz, Emrah 2 Kozhukhov, Igor’ Borisovich 2 Laysirikul, Ekkachai 2 Namnak, Chaiwat 2 Quinteiro, Teresa M. 2 Sangkhanan, Kritsada 2 Sawatraksa, Nares 2 Williams, Gerald 2 Zhuchok, Yu. V. 1 Adeniji, Adenike Olusola 1 Al-Kharousi, Fatma Ahmed 1 Almeida, José Humberto S. 1 André, Jorge M. 1 Aoki, Kunimasa 1 Ayik, Gonca 1 Cain, Alan J. 1 Can, Mahir Bilen 1 East, James 1 Gomes, Gracinda M. S. 1 Grensing, Anna-Louise 1 Han, Xuefeng 1 Hu, Huabi 1 Ibrahim, Muhammad Jamilu 1 Jesus, Manuel M. 1 Jones, Peter R. 1 Kajitori, Kazuaki 1 Kehinde, R. 1 Kinyon, Michael K. 1 Mansour, Toufik 1 Mazorchuk, Volodymyr 1 Mitchell, James D. 1 Moura, Ana 1 Nordahl, Thomas E. 1 Pei, Huisheng 1 Rosenfeld, Vladimir Raphael 1 Rungratgasame, Thitarie 1 Saito, Tatsuhiko 1 Santos, Paulo Guilherme 1 Schork, Matthias 1 Stein, Itamar 1 Toichkina, E. A. 1 Udomkavanich, Patanee 1 Xu, Bo 1 Yang, Mei 1 Yaroshevich, V. A. 1 Yigit, Ebru 1 You, Taijie 1 Zhou, Huijuan
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#### Cited in 28 Serials

 19 Semigroup Forum 11 Communications in Algebra 3 International Journal of Algebra and Computation 3 Journal of Mathematical Sciences (New York) 3 Turkish Journal of Mathematics 3 Bulletin of the Malaysian Mathematical Sciences Society. Second Series 3 Journal of Algebra and its Applications 2 Algebra Colloquium 1 Bulletin of the Australian Mathematical Society 1 Discrete Applied Mathematics 1 Discrete Mathematics 1 Mathematical Notes 1 Czechoslovak Mathematical Journal 1 International Journal of Mathematics and Mathematical Sciences 1 Journal of Algebra 1 Journal of Pure and Applied Algebra 1 Proceedings of the Edinburgh Mathematical Society. Series II 1 Theoretical Computer Science 1 Acta Mathematica Hungarica 1 Bulletin of the Iranian Mathematical Society 1 Proceedings of the Royal Society of Edinburgh. Section A. Mathematics 1 Journal of Difference Equations and Applications 1 Journal of Mathematical Chemistry 1 Honam Mathematical Journal 1 Algebras and Representation Theory 1 Communications of the Korean Mathematical Society 1 Thai Journal of Mathematics 1 Asian-European Journal of Mathematics
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#### Cited in 13 Fields

 65 Group theory and generalizations (20-XX) 13 Combinatorics (05-XX) 6 Order, lattices, ordered algebraic structures (06-XX) 5 General algebraic systems (08-XX) 3 Associative rings and algebras (16-XX) 1 History and biography (01-XX) 1 Mathematical logic and foundations (03-XX) 1 Commutative algebra (13-XX) 1 Linear and multilinear algebra; matrix theory (15-XX) 1 Category theory; homological algebra (18-XX) 1 General topology (54-XX) 1 Computer science (68-XX) 1 Biology and other natural sciences (92-XX)

#### Wikidata Timeline

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