

1966 
Newark Senior High School, Newark,
Delaware, U.S.A. (A.F.S. scholarship) 
1970 
University of Athens, Greece,
Department of Mathematics 
1971 
Degree in Education from SELETE, a UN
school in Athens, Greece 
1972 
Masters Degree in Operational Research
from the University of Southampton, United Kingdom 
197273 
Institute of Applied Mathematics of
the University of Heidelberg, Germany 
197475 
Computer Science Department of the
University of Kaiserslautern, Germany 
1976 
Masters degree in Computer Science
from the University of WisconsinMadison, U.S.A. 
1978 
Ph.D. in Computer ScienceOperations
Research from North Carolina State University in Raleigh, U.S.A. 
1. 
Teaching Assistant at the Universities of Heidelberg and
NCSU 
2. 
Research Assistant at the Universities of Wisconsin and
Kaiserslautern 
3. 
Assistant Professor at the University of Athens, Unit of
Applied Mathematics; Fall semester of 1979 
4. 
Visiting Assistant Professor at the University of Kansas,
Department of Computer Science; Spring semester 1980 
5. 
Assistant Professor at the University of Kansas,
Department of Computer Science; Fall semester 1980 to summer 1984 
6. 
IntraUniversity Professor at the University of Kansas,
Department of Electrical Engineering; 198384 
7. 
Associate Professor at the University
of Kansas, Department of Computer Science; Fall semester 1984 to summer
1996 
8. 
Visiting Professor at the National Technical University
of Athens, Greece, Department of Electrical and Computer Engineering;
Spring semester of 1987. (United Nations Development Program  TOKTEN 
consultant.) 
9. 
Visiting Professor at Moscow State University (Lomonossov),
U.S.S.R., Department of Mechanics and Mathematics; Spring semester of
1990. (Fulbright Scholar.) 
10. 
Member of the Russian and East European Studies (REES)
Program of the University of Kansas; Spring semester 1993. 
11. 
Professor
at the University of
Kansas, Department of Computer Science; Fall semester 1996.

12. 
Associate Professor at the University of Thessaly,
Department Theoretical and Applied Sciences (19982000) and Department
of Computer and Communication Engineering; Fall semester 2001 to
2004. 
13. 
Professor at the University of Thessaly, Department
of Electrical and Computer Engineering; Fall semester 2004 to
present. 

He has been /Erasmus/Socrates coordinator/ of the Department of Computer
and Communications Engineering since 2002 and the /Erasmus LLP delegate/
since 2008.
He has signed partnership agreements with the following universities:
Vilnius 01 (LT), MÃ¼nchen 02 (TUM, DE), Madrid 05 (E), Sevilla 01 (E), Sakarya 01 (TR), Istanbul 14 (TR), Bucurest 09 (RO), Praha 10 (CZ), Sofia 06 (BG), Sofia 16 (BG), Perugia 01 (I), Turku 01 (SF), Turku 02 (SF).

1. 
First Prize:
The paper "A new method for polynomial real root
isolation" (Publication No. 3) received the First Prize in the student
paper competition of the ACM conference in Atlanta, Georgia, 1978. 
2. 
IntraUniversity Professorship: Academic year
198384one of six IntraUniversity Professorships awarded that year; to
be associated with the Department of Electrical Engineering of the
University of Kansas. 
3. 
Sabbatical leave: Spring semester of 1987; to
complete the writing of a book and teach at the Electrical and Computer
Engineering Department of the National Technical University of Athens.
(United Nations Development Program  TOKTEN  consultant.) 
4. 
Fulbright grant: Summer (June and July) of 1989;
to intensively study Russian at the Bryn Mawr College Russian Language
Institute. 
5. 
Fulbright grant: Spring Semester of 1990; to teach
Computer Algebra at the Department of Mechanics and Mathematics of the
Moscow State University (Lomonossov), U.S.S.R. 
6. 
NSF grant: Spring Semester of 1992; to create a
mathematical computing laboratory (CoPrincipal Investigator). 
7. 
Sabbatical leave: Academic year 199596; to
complete the writing of another book. 
The following forgotten papers were rediscovered by
Akritas: Vincent's paper of 1836 (in 1975, see publications
5, 16), and Lloyd's paper "On the forgotten Mr. Vincent" Sylvester's paper of 1853
and Van Vleck's paper of 1899 (in 1985), and Sylvester's determinant
identity of 1851 (in 1992). Based on these papers the following methods
were developed: 


1. 
The VincentCollinsAkritas bisection method for isolating the real
roots of a polynomial equation see publication 1;
misleadingly, some authors refer to it as the "Descartes' method". The
method was developed immediately after Akritas' discovery of Vincent's
paper, and has been implemented in the computer algebra system maple;
an excellent presentation of the method, along with a complete example,
can be found in the (French) lecture notes of the
University of Lille, France. As Alesina and Galuzzi (1998a) point out,
the VincentCollinsAkritas method is one way of implementing Vincent's
theorem; see also their second paper (1998b).
Moreover, Alesina and Galuzzi masterly used Vincent's theorem and Obreschkoff's work of 192023, (which was also
independently rediscovered by Ostrowski in 1950)
to prove that the VincentCollinsAkritas method terminates.
See the papers by Mehlhorn et al. (2006), Yap et al (2006) and
Sharma's PhD Thesis; in all these the VincentCollinsAkritas method is being
misleadingly referred to
as "Decartes' method".

2. 
The VincentAkritasStrzebonski continued fractions method for
isolating the real roots of a polynomial equation (see publications
3, 11,
14, 19,
22, 28,
41, 58).
The method was developed in 1978 and it
has been implemented in: (a) the computer algebra system Mathematica
and (b) the open source algebraic library SYNAPS (see the paper by
Tsigaridas and Emiris).
It has been demonstrated both theoretically and
empirically, that it is the fastest real root isolation method existing;
see the papers 58 and Tsigaridas and Emiris.
As Alesina and Galuzzi
(1998a) point out, the VincentAkritasStrzebonski method is another way
of implementing Vincent's theorem.
Moreover, Alesina and Galuzzi masterly used Vincent's theorem and Obreschkoff's work of 192023, (which was also
independently rediscovered by Ostrowski in 1950)
to prove that the VincentAkritasStrzebonski method terminates.
Of interest are Vikram Sharma's PhD Thesis and paper (2007), where this method if referred to as
Akritas' continued fractions method. Sharma removed the hypothesis of the "ideal" positive
lower root bound and showed that the VincentAkritasStrzebonski method is still polynomial
in time.

3. 
A method for approximating the real
roots of a polynomial equation (see publications
23, 24). This method uses continued fractions, an
idea by Lagrange and Vincent's theorem. It was developed in 1981
together with K.H. Ng. 
4. 
A subresultant method for computing
polynomial remainder sequences (prs's) (see publications
29, 31, 32,
33, 34,
35, 36). Developed in 1986, this is the
"best" method for computing prs's, in the sense that the coefficients
obtained are the smallest possible (without gcd computations). It is
based on the papers by Sylvester and Van Vleck and it is unique in that
it does not perform actual polynomial divisions but matrix
triangularization. 
5. 
A new, improved, matrix
triangularization subresultant method for computing polynomial remainder
sequences (see publications 40,
43). It is based on Sylvester's determinant identity and it is an
improvement over the above method (4) in the sense that the theoretical
results obtained are independent of Van Vleck's theorem (which cannot
always be used); moreover, now a matrix of smaller order is being
transformed and the sign of the coefficients is computed exactly.
Developed in 1992 together with E. K. Akritas and G. I. Malashonok. 
6. 
An improved (faster) variant of the
matrixtriangularization subresultant prs method for the computation of
a greatest common divisor of two polynomials along with their polynomial
remainder sequence (see publication 51). The improvement is based on the work of Malaschonok
who proposed a new, recursive method for the solution of systems of
linear equations in integral domains. The complexity is the same as the
complexity of matrix multiplication. Developed in 2000 together with G.
I. Malashonok. 
7. 
A new (linear complexity) method for computing upper bounds on the
positive roots of polynomials; see publication 69. This method
is based on a generalization and an extension of a theorem by Doru
Stefanescu and gives the sharpest upper bounds on the positive roots
(among all existing methods such as Cauchy, Lagrange, Kioustelidis etc).
Using our new method to compute positive root bounds we were able to
improve the performance of the VincentAkritasStrzebonski continued
fractions real root isolation method; especially for the case of very
many very large roots the improvement was in the order of 300%.

8. 
A new (quadratic complexity) method for computing upper bounds on
the positive roots of polynomials; see publications 75 and 76. Using our
new quadratic complexity bound we were able to further improve the
performance of the VincentAkritasStrzebonski continued fractions real
root isolation method, making it the fastest for all classes of polynomials.

9. 
A new method for computing subresultant polynomial remainder sequences; see publication 92. It is based on Sylvester's form of the resultant of 1853 and uses a Theorem by Pell and Gordon of 1917.

10. 
Extended Van Vleck's matrix triangularization method to compute both complete and incomplete Sturm sequences; see publication 93. Used a totally forgotten theorem of 1917 by Pell and Gordon. 
11. 
Three new methods for computing subresultant polynomial remainder sequences; see publication 94. 
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