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Kherson, Ukraine

Lvov M.S.,Kherson State University
Cybernetics and Systems Analysis | Year: 2015

. This article considers the problem of generating polynomial invariants for iterative loops with loop initialization statements and nonsingular linear operators in loop bodies. The set of such invariants forms an ideal in the ring of polynomials in the loop variables. Two algorithms are presented one of which calculates basic invariants for a linear operator in the form of a Jordan cell and the other calculates basic invariants for a diagonalizable linear operator with an irreducible minimal characteristic polynomial. The following theorem on the structure of the basis of the ideal of invariants for such an operator is proved: this basis consists of basic invariants of Jordan cells and basic invariants of the diagonalizable part of the linear operator being considered. © 2015 Springer Science+Business Media New York


Lvov M.S.,Kherson State University
Cybernetics and Systems Analysis | Year: 2016

The paper presents a new method to prove the invariance of the system of linear inequalities and completability of linear definite iterative loops for imperative programs. Loop body is a linear operator that transforms the vector of program variables. The method takes into account loop precondition, as well as the condition of loop repetition in the form of a set of systems of linear inequalities. The method is based on the construction and analysis of the spectrum of linear operator and calculation of the number of loop iterations after which the invariance is either provided or disproved. The theory is illustrated by examples. © 2016, Springer Science+Business Media New York.


Lvov M.S.,Kherson State University
Cybernetics and Systems Analysis | Year: 2010

The problem of generating polynomial invariants of special type for iterative loops with a linear mapping in the loop body is considered. A technique is proposed to generate such invariants based on the analysis of characteristic polynomials of linear mappings. © 2010 Springer Science+Business Media, Inc.


The ability to discriminate parasitized and non-parasitized hosts allows the parasitoids to avoid intraspecific and often interspecific competition. In 2005-2009, the incidence of mixed infestation of Polistes nimpha (Christ) colonies by parasitoids Elasmus schmitti Ruschka (Hymenoptera, Eulophidae) and Latibulus argiolus (Rossi) (Hymenoptera, Ichneumonidae) was analyzed. In settlements of different types, the frequencies of mixed infestation deviated from the values expected in case of random distribution. The presence or absence of discrimination ability cannot be confirmed unequivocally based on our material. The data obtained are discussed in relation to the biological features of parasitoids. © 2011 Pleiades Publishing, Ltd.


The ability to discriminate parasitized and non-parasitized hosts allows the parasitoids to avoid the intraspe-cies and often interspecies competition. In 2005-2009, an analysis of the occurrence of mixed infestation of Polistes nimpha (Christ) colonies by parasitoids Elasmus schmitti Ruschka (Hymenoptera, Eulophidae) and Latibulus argiolus (Rossi) (Hymenoptera, Ichneumonidae) was performed. In settlements of different types, a deviation in the values of the mixed infestation from the expected ones under random value distribution was observed The data obtained do not allow coming to an explicit conclusion as to parasitoids having or lacking the discriminating ability. The data obtained are discussed in relation to the biological features of parasitoids.

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