scholarly journals Truth-table Unoids not Satisfying the Urzyczyn's Conditions

2021 ◽  
pp. 33-43
Author(s):  
Дмитрий Ольгердович Дадеркин
Keyword(s):  
Algebraic System ◽  
Sufficient Conditions ◽  
Truth Table

Достаточные условия табличности, одного из важных свойств, характеризующих работу программы в алгебраической системе, были предложены в работах П. Ужичина \cite {U1,U2,U3}. В данной работе описываются такие достаточные условия табличности, которые позволяют строить табличные уноиды,не удовлетворяющие условиям Ужичина. Sufficient conditions of truth-table property, one of the important properties that characterize the work of a program in an algebraic system, were proposed in the works of P. Urzyczyn \cite {U1,U2,U3}. In this work such sufficient conditions of truth-table property are described, that allow constructing truth-table unoids that not satisfy the conditions of Urzyczyn.

Nonlinear boundary-value problems for degenerate differential-algebraic systems

2020 ◽  
Vol 17 (3) ◽  
pp. 313-324
Author(s):  
Sergii Chuiko ◽  
Ol'ga Nesmelova
Keyword(s):  
Boundary Value Problem ◽  
Boundary Value Problems ◽  
Algebraic System ◽  
Boundary Value ◽  
Sufficient Conditions ◽  
Necessary And Sufficient Conditions ◽  
Weakly Nonlinear ◽  
Differential Algebraic System ◽  
Linear Differential ◽  
Necessary And Sufficient

The study of the differential-algebraic boundary value problems, traditional for the Kiev school of nonlinear oscillations, founded by academicians M.M. Krylov, M.M. Bogolyubov, Yu.A. Mitropolsky and A.M. Samoilenko. It was founded in the 19th century in the works of G. Kirchhoff and K. Weierstrass and developed in the 20th century by M.M. Luzin, F.R. Gantmacher, A.M. Tikhonov, A. Rutkas, Yu.D. Shlapac, S.L. Campbell, L.R. Petzold, Yu.E. Boyarintsev, V.F. Chistyakov, A.M. Samoilenko, O.A. Boichuk, V.P. Yacovets, C.W. Gear and others. In the works of S.L. Campbell, L.R. Petzold, Yu.E. Boyarintsev, V.F. Chistyakov, A.M. Samoilenko and V.P. Yakovets were obtained sufficient conditions for the reducibility of the linear differential-algebraic system to the central canonical form and the structure of the general solution of the degenerate linear system was obtained. Assuming that the conditions for the reducibility of the linear differential-algebraic system to the central canonical form were satisfied, O.A.~Boichuk obtained the necessary and sufficient conditions for the solvability of the linear Noetherian differential-algebraic boundary value problem and constructed a generalized Green operator of this problem. Based on this, later O.A. Boichuk and O.O. Pokutnyi obtained the necessary and sufficient conditions for the solvability of the weakly nonlinear differential algebraic boundary value problem, the linear part of which is a Noetherian differential algebraic boundary value problem. Thus, out of the scope of the research, the cases of dependence of the desired solution on an arbitrary continuous function were left, which are typical for the linear differential-algebraic system. Our article is devoted to the study of just such a case. The article uses the original necessary and sufficient conditions for the solvability of the linear Noetherian differential-algebraic boundary value problem and the construction of the generalized Green operator of this problem, constructed by S.M. Chuiko. Based on this, necessary and sufficient conditions for the solvability of the weakly nonlinear differential-algebraic boundary value problem were obtained. A typical feature of the obtained necessary and sufficient conditions for the solvability of the linear and weakly nonlinear differential-algebraic boundary-value problem is its dependence on the means of fixing of the arbitrary continuous function. An improved classification and a convergent iterative scheme for finding approximations to the solutions of weakly nonlinear differential algebraic boundary value problems was constructed in the article.

scholarly journals Truth-table Unoids Satisfying the Urzyczyn's Conditions

2021 ◽  
pp. 59-70
Author(s):  
Дмитрий Ольгердович Дадеркин
Keyword(s):  
Sufficient Conditions ◽  
Truth Table

В работах П. Ужичина [1-3] были предложены достаточные условия табличности уноидов, однако эти алгебраические условия Ужичина трудно проверяемы на практике и не дают возможности строить нетривиальные примеры табличных уноидов. В данной работе вводятся понятия локально-заданных и разделённых уноидов и доказывается, что разделённые уноиды удовлетворяют условиям Ужичина. Таким образом, получены просто проверяемые достаточные условия, при выполнении которых уноид, в том числе и с достаточно сложно заданным связным множеством, является табличным. In the works of P. Urzyczyn [1-3] were suggested sufficient conditions of truth-table property of unoids, however, these algebraic conditions of Urzyczyn are difficult to be checked in practice and leave no possibilities to build non-trivial examples of truth-table unoids. In this work concepts of locally-given and divided unoids are proposed, and it is proved that divided unoids satisfy the conditions of Urzyczyn. Thus, simply verifiable sufficient conditions are achieved, on the basis of which unoid, including with enough complicated specified connected underlying set, is truth-table.

scholarly journals Seminonlinear boundary value problems for nondegenerate differential-algebraic system

2019 ◽  
Keyword(s):  
Boundary Value Problem ◽  
Boundary Value Problems ◽  
Algebraic System ◽  
Boundary Value ◽  
Sufficient Conditions ◽  
Differential Algebraic Equations ◽  
Problem Solution ◽  
Algebraic Equations ◽  
Arbitrary Continuous Function ◽  
Differential Algebraic System

In the article we obtained sufficient conditions of the existence of the nonlinear Noetherian boundary value problem solution for the system of differential-algebraic equations which are widely used in mechanics, economics, electrical engineering, and control theory. We studied the case of the nondegenerate system of differential algebraic equations, namely: the differential algebraic system that is solvable relatively to the derivative. In this case, the nonlinear system of differential algebraic equations is reduced to the system of ordinary differential equations with an arbitrary continuous function. The studied nonlinear differential-algebraic boundary-value problem in the article generalizes the numerous statements of the non-linear non-Gath boundary value problems considered in the monographs of А.М. Samoilenko, E.A. Grebenikov, Yu.A. Ryabov, A.A. Boichuk and S.M. Chuiko, and the obtained results can be carried over matrix boundary value problems for differential-algebraic systems. The obtained results in the article of the study of differential-algebraic boundary value problems, in contrast to the works of S. Kempbell, V.F. Boyarintsev, V.F. Chistyakov, A.M. Samoilenko and A.A. Boychuk, do not involve the use of the central canonical form, as well as perfect pairs and triples of matrices. To construct solutions of the considered boundary value problem, we proposed the iterative scheme using the method of simple iterations. The proposed solvability conditions and the scheme for finding solutions of the nonlinear Noetherian differential-algebraic boundary value problem, were illustrated with an example. To assess the accuracy of the found approximations to the solution of the nonlinear differential-algebraic boundary value problem, we found the residuals of the obtained approximations in the original equation. We also note that obtained approximations to the solution of the nonlinear differential-algebraic boundary value problem exactly satisfy the boundary condition.

DYNAMIC BEHAVIOR ANALYSIS OF A DIFFERENTIAL-ALGEBRAIC PREDATOR–PREY SYSTEM WITH PREY HARVESTING

2013 ◽  
Vol 21 (03) ◽  
pp. 1350022 ◽  
Author(s):  
WEI LIU ◽  
YUXIAN CHEN ◽  
CHAOJIN FU
Keyword(s):  
System Theory ◽  
Hopf Bifurcation ◽  
Algebraic System ◽  
Bifurcation Theory ◽  
Sufficient Conditions ◽  
Formal Series ◽  
Series Expansions ◽  
Predator Prey ◽  
Prey System ◽  
Differential Algebraic System

This paper studies a differential-algebraic predator–prey system with prey harvesting, which consists of two differential equations and an algebraic equation. By using the differential-algebraic system theory, bifurcation theory and formal series expansions, we investigate the Hopf bifurcation and center stability of the differential-algebraic predator–prey system. Some sufficient conditions on these issues are obtained. In addition, numerical simulations illustrate the effectiveness of our results and their biological implications are discussed.

About the equilibrium positions of a matrix differential-algebraic boundary value problem

2019 ◽  
Vol 33 ◽  
pp. 218-231
Author(s):  
Sergei Chuiko ◽  
Olga Nesmelova
Keyword(s):  
Boundary Value Problem ◽  
Algebraic System ◽  
Boundary Value ◽  
Sufficient Conditions ◽  
Green Operator ◽  
Solvability Conditions ◽  
Differential Algebraic System ◽  
The Matrix ◽  
Matrix Differential ◽  
Generalized Green Operator

In the article we found the solvability conditions and the construction of the generalized Green operator of the linear Noetherian matrix differential-algebraic boundary value problem. We obtained sufficient conditions of transformationsof the matrix differential-algebraic equation to a traditional differential-algebraic equation with an unknown in the form of a column vector. The problem that reviewed in the article continues the study of solvability conditions for the linear Noetherian boundary value problems given in the monographs of M.V. Azbelev, V.P. Maksimov, L.F. Rakhmatullina, A.M. Samoilenko and A.A. Boichuk. We investigated the general case when the linear bounded operator corresponding to the homogeneous part of the linear Cauchy problem for the matrix differential-algebraic system does not have the reverse operator. We introduced the definition of the equilibrium positions of the matrix differential-algebraic system and the matrix differential-algebraic boundary-value problem to solve the matrix differential-algebraic boundary-value problem. We proposed sufficient conditions of existence and constructive schemes for finding the equilibrium positions of the matrix differential-algebraic system and the matrix differential-algebraic boundary value problem. The cases~of equilibrium positions of the matrix differential-algebraic system, which are constant matrices, and equilibrium positions depending on an independent variable are considered separately. To solve the matrix differential-algebraic boundary-value problem, we used the original solvability conditions and~the construction of the general solution of the Sylvester-type matrix equation, while the Moore-Penrose matrix pseudoinverse technique was essentially used. In the article we constructed the generalized Green operator of the linear Noetherian matrix differential-algebraic boundary value problem. The proposed solvability conditions and the construction of the generalized Green operator of the linear Noetherian matrix differential-algebraic boundary value problem, were illustrated in detail with examples.

Some Contributions to the Theory of Near-Critical Bisexual Branching Processes

2007 ◽  
Vol 44 (02) ◽  
pp. 492-505
Author(s):  
M. Molina ◽  
M. Mota ◽  
A. Ramos
Keyword(s):  
Branching Process ◽  
Branching Processes ◽  
Sufficient Conditions ◽  
Positive Probability ◽  
Limit Laws ◽  
Bisexual Branching Processes ◽  
Probabilistic Evolution

We investigate the probabilistic evolution of a near-critical bisexual branching process with mating depending on the number of couples in the population. We determine sufficient conditions which guarantee either the almost sure extinction of such a process or its survival with positive probability. We also establish some limiting results concerning the sequences of couples, females, and males, suitably normalized. In particular, gamma, normal, and degenerate distributions are proved to be limit laws. The results also hold for bisexual Bienaymé–Galton–Watson processes, and can be adapted to other classes of near-critical bisexual branching processes.

The extinction time of a general birth and death process with catastrophes

1986 ◽  
Vol 23 (04) ◽  
pp. 851-858 ◽  
Author(s):  
P. J. Brockwell
Keyword(s):  
Laplace Transform ◽  
Size Distribution ◽  
Sufficient Conditions ◽  
Necessary And Sufficient Conditions ◽  
Death Process ◽  
Extinction Time ◽  
Birth And Death Process ◽  
Different Types ◽  
The Laplace Transform ◽  
Necessary And Sufficient

The Laplace transform of the extinction time is determined for a general birth and death process with arbitrary catastrophe rate and catastrophe size distribution. It is assumed only that the birth rates satisfyλ0= 0,λj> 0 for eachj> 0, and. Necessary and sufficient conditions for certain extinction of the population are derived. The results are applied to the linear birth and death process (λj=jλ, µj=jμ) with catastrophes of several different types.

Normal approximations to discrete unimodal distributions

1986 ◽  
Vol 23 (04) ◽  
pp. 1013-1018
Author(s):  
B. G. Quinn ◽  
H. L. MacGillivray
Keyword(s):  
Stationary Distribution ◽  
Sufficient Conditions ◽  
Random Variables ◽  
Hypergeometric Distribution ◽  
Death Process ◽  
Normal Approximations ◽  
Discrete Random Variables ◽  
Birth Death

Sufficient conditions are presented for the limiting normality of sequences of discrete random variables possessing unimodal distributions. The conditions are applied to obtain normal approximations directly for the hypergeometric distribution and the stationary distribution of a special birth-death process.

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