g. darbo [rend. sem. math. univ. padova, 24 (1955) 84--92] used the measure of noncompactness to investigate operators whose properties can be characterized as being intermediate between those of contraction and compact operators. in this paper, we apply the darbo's fixed point theorem for solving infinite system of linear equations in some sequence spaces.

A common problem for experimental space physicists is the determination of the "attitude matrix" T which transforms vectors between representations in X and Xl coordinate systems according to Vx = TXX' VXI. Solution of this problem using the standard Eulerian angle techniques is in general tedious and circuitous. A straightforward, simple, and efficient solution for the transformation matrix is...

We deal with matrix transformations preserving the starshape of sequences. The main result gives the necessary and sufficient conditions for a lower triangular matrix A to preserve the starshape of sequences. Also, we discuss the nature of the mappings of starshaped sequences by some classical matrices. 2000 Mathematics Subject Classification. 40C05, 40D05, 40G05.

There are many programming situations where it would be convenient to conceal the meaning of code, or the meaning of certain variables. This can be achieved through program transformations which are grouped under the term obfuscation. Obfuscation is one of a number of techniques that can be employed to protect sensitive areas of code. This paper presents obfuscation methods for the purpose of c...