**Stela**** Dimitrova Zhelezova**

Institute of Mathematics and
Informatics, Bulgarian Academy of Sciences

**Research
Interests**:

construction and study of combinatorial resolvable designs,
orthogonal resolutions, spreads and parallelisms of projective spaces, cryptographic
properties of boolean functions and S-boxes

**Address:**

Institute
of Mathematics and Informatics

P.O.Box
323

5000 V.Tarnovo

Bulgaria

e-mail : stela@math.bas.bg

(v,c x u,lambda)-splitting
BIBDs

*Number
of Pasch configurations of cyclic STS(45)*

Cyclic parallelisms of PG(5,2)

2-parallelisms
of PG(5,2) with automorphisms
of order 31

Transitive
2-parallelisms of PG(5,2)

*Regular
parallelisms of PG(3,4) with deficiency m=5*

Parallelisms of PG(3,4) with automorphisms of
order 3

Parallelisms
of PG(3,4) with cyclic automorphism
group of order 4

All Parallelisms
of PG(3,4) with full automorphism
group of order 4

*Parallelisms
of PG(3,4) with full automorphism
group of order 4m, m > 1*

Parallelisms of PG(3,4) with automorphisms of
order 5

Parallelisms of PG(3,4) with automorphisms of
order 7

Parallelisms of PG(3,5) with automorphism of order
13

*Parallelisms
of PG(3,5) with cyclic automorphism
group of order 8 and specific structure*

*Parallelisms
of PG(3,5) with an automorphism
group of order 25*