Wyniki wyszukiwania - Biblioteka Nauki

1

Operator-splitting and Lagrange multiplier domain decomposition methods for numerical simulation of two coupled Navier-Stokes fluids

100%

Bresch D. , Koko J.

International Journal of Applied Mathematics and Computer Science

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2006

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tom 16

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nr 4

419-429

EN

We present a numerical simulation of two coupled Navier-Stokes flows, using ope-rator-split-ting and optimization-based non-overlapping domain decomposition methods. The model problem consists of two Navier-Stokes fluids coupled, through a common interface, by a nonlinear transmission condition. Numerical experiments are carried out with two coupled fluids; one with an initial linear profile and the other in rest. As expected, the transmission condition generates a recirculation within the fluid in rest.

2

The domination over time and its discretisation

100%

ABBASNEZHAD N. , MEHRI-TAKMEH J. , VAKILI J.

Operations Research and Decisions

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2020

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tom 30

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nr 1

5-24

EN

Domination in graphs is well known and has been an extensively researched branch of graph the-ory. Since the variation over time is one of the important properties of real-world networks, we study the influence of time on the domination problem. In this paper, we introduce the domination over time problem, including time delay on arcs. Then, an optimal solution to its discretisation is obtained, which is the solution of the original problem.

3

Homogenization of linear elastic shells: [gamma]-convergence and duality. Part II. Dual homogenization

100%

Telega J. J. , Lewiński T.

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1998

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tom Vol. 46, nr 1

11-21

EN

The elastic shell model introduced in [1] is studied from the point of view of dual homogenization. The density of the homogenized complementary energy is derived and the dual homogenization theorem is formulated.

4

Systems of variational inequalities related to economic equilibrium

100%

Naniewicz Z. , Nockowska M.

Control and Cybernetics

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2007

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tom Vol. 36, no 4

889-909

EN

In the paper a new approach to the Walrasian general equilibrium model of economy is presented. The classical market clearing condition is replaced by suitably formulated variational inequality. It states that the market clears for a commodity if its equilibrium price is positive; otherwise, there may be an excess supply of the commodity in equilibrium and then its price is zero. Such approach enables establishing new existence results without assumptions which were fundamental for the currently used methods: (i) Dis-utility functions are not required to be strictly convex and they may attain their minima in the consumption sets (the local nonsatiation of preferences is not required). (ii) The boundary of the positive orthant is allowed for the price vector in equilibrium. It allows for investigation of certain new problems, e.g. bankruptcy conditions.

5

Dualne liniowe dodatnie układy dyskretne z jednym opóźnieniem

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Kociszewski R.

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2007

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tom R. 11, nr 2

PL

W pracy rozpatrzono problem dualności liniowych dodatnich układów dyskretnych z jednostkowym opóźnieniem w wektorze stanu. Pokazano, że w ogólnym przypadku dodatnie układy z opóźnieniem nie są układami dualnymi. Aby spełnione były warunki konieczne i wystarczające dualności (tj. równoważność warunków osiągalności i obserwowalności) należy rozpatrywać układy dodatnie z czystym opóźnieniem. Dla tej klasy układów sformułowano kryteria całkowitej osiągalności i całkowitej obserwowalności.

EN

The problem of duality of linear positive discrete-time systems with one delay in state is considered. It is shown that the two positive discrete-time systems are not dual in general case. These systems may be dual only in the case of systems with pure delay. Necessary and sufficient conditions for complete reachability and complete observability of the systems with pure delay are established. A method for computing of the control sequence which transfer the system from zero complete initial state to the desired complete state and method for computing of the output sequence are given.

6

On duality of submodule lattices

100%

Czédli G. , Takách G.

Discussiones Mathematicae - General Algebra and Applications

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2000

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tom 20

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nr 1

43-49

EN

An elementary proof is given for Hutchinson's duality theorem, which states that if a lattice identity λ holds in all submodule lattices of modules over a ring R with unit element then so does the dual of λ.

7

THE UNFOLDING OF TRUTH AND SELF-REPRESENTATION WITHIN THE CRACKED MIRROR IN SHAKESPEARE’S RICHARD II

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Ekmekçioğlu N.

Gender Studies

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2013

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tom 12

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nr 1

32-51

EN

Shakespeare’s Richard II deals with the controversy between the divine and the mortal aspects of the King. According to Kantorowicz’s The King’s Two Bodies, the King had two bodies: a Body Natural and a Body Politic. In the deposition scene of the play, Richard exploits the divine authority by undoing himself as if in a sacramental ceremony and asks for a mirror in order to see whether the change in his kingly nature has affected his face. My paper will deal with the unfolding of unendurable truth and the self-representation of Richard II in the duality of his image within the cracked mirror.

8

Optimality conditions and duality for generalized fractional minimax programming involving locally Lipschitz (b,Ψ,Φ,ρ) -univex functions

100%

Antczak T. , Mishra S. K. , Upadhyay B. B.

Control and Cybernetics

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2018

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tom Vol. 47, no. 1

5--32

EN

In this paper, we are concerned with optimality conditions and duality results of generalized fractional minimax programming problems. Suﬃcient optimality conditions are established for a class of nondiﬀerentiable generalized fractional minimax programming problems, in which the involved functions are locally Lipschitz (b,Ψ,Φ,ρ)-univex. Subsequently, these optimality conditions are utilized as a basis for constructing various parametric and nonparametric duality models for this type of fractional programming problems and proving appropriate duality theorems.

9

Nonconvex minimization related to quadratic double-well energy - approximation by convex problemsenergy – approximation by convex problems

100%

Naniewicz Z. , Puchała P.

Control and Cybernetics

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2012

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tom Vol. 41, no. 3

525-543

EN

A double-well energy expressed as a minimum of two quadratic functions, called phase energies, is studied taking into account minimization of the corresponding integral functional. Such integral, as being not sequentially weakly lower semicontinuous, does not admit classical minimizers. To derive the relaxation formula for the infimum, the appropriate minimizing sequence is constructed. It consists of solutions of some approximating convex problems involving characteristic functions related to the phase energies. The weak limit of this sequence and the weak limit of the sequence of solutions of dual problems combined with the weak-star limits of the characteristic functions related to the phase energies allow to establish the final relaxation formula. It is also shown that infimum can be expressed by the Young measure associated with constructed minimizing sequence. An explicit form of Young measure in some regions of the involved domain is calculated.

10

Longitudinal shearing of elastic-plastic fibrous composite with frictional fibre-matrix interface

100%

Więckowski Z.

Journal of Theoretical and Applied Mechanics

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1998

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tom nr 4

854-877

EN

The problem of macroscopic behaviour of periodic, elastic-plastic, fibrous composite material with frictional fibre-matrix interface is considered. Anti-plane shear of the material is analysed. The problem is formulated with the help of variational inequalities using the two approaches: displacement-based and stress-based ones. The variational inequalities are solved using the finite element method. In the case of stress-based approach, the Prandl stress function is utilized. The obtained effective constitutive model of the composite can be used directly in analysis of the problem of torsion of a composite bar with a fine, periodic structure.

PL

W pracy rozważono zagadnienie efektywnych własności periodycznego, sprężysto-plastycznego kompozytu włóknistego, poddanego stanowi anty-płaskiego ścinania, uwzględniając zjawisko tarcia na powierzchni łączącej włókno i matrycę. Zagadnienie zostało sformułowane w przemieszczeniach i naprężeniach w postaci nierówności wariacyjnych, które rozwiązano za pomocą metody elementów skończonych. W przypadku sformułowania naprężeniowego zastosowano funkcje naprężeń Prandtla. Otrzymane efektywne związki konstytutywne dla rozważanego kompozytu mogą być bezpośrednio wykorzystane w analizie zagadnienia swobodnego skręcania pręta kompozytowego o periodycznej strukturze włóknistej.

11

The domination over time and its discretisation

100%

Abbasnezhad N. , Mehri-Takmeh J. , Vakili J.

Operations Research and Decisions

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2020

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tom Vol. 30, No. 1

5--24

EN

Domination in graphs is well known and has been an extensively researched branch of graph theory. Since the variation over time is one of the important properties of real-world networks, we study the influence of time on the domination problem. In this paper, we introduce the domination over time problem, including time delay on arcs. Then, an optimal solution to its discretisation is obtained, which is the solution of the original problem.

12

Extensions of Pontryagin hypergroups

100%

Heyer H. , Kawakami S.

Probability and Mathematical Statistics

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2006

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tom Vol. 26, Fasc. 2

245--260

EN

The purpose of this paper is to investigate the extension problem for the category of commutative hypergroups. In fact, by applying the new notion of a field of compact subhypergroups, sufficiently many extensions can be established, and among them splitting extensions can be characterized. Moreover, the duality of extensions will be studied via duality of fields of hypergroups. The method of extension via fields of hypergroups yields the construction of Pontryagin hypergroups which do not arise from group-theoretic objects.

13

Managerial Entrenchment and Firm Performance: Evidence from Moroccan Listed Companies

88%

Bousetta M.

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tom 29(3)

40-62

EN

Purpose: Grounded in agency and entrenchment theories, this study assumes that CEOs’ propensity to entrench themselves can affect firm performance. The purpose of this article is to investigate the relationship between dimensions and mechanisms through which managers entrench themselves and influence firm performance. Design/methodology/approach: The article uses OLS regression to explain the assumed relationships between managerial entrenchment and firm performance. The study is based on a sample of 55 Moroccan listed companies over the period 2010–2015. Findings: Taken together, the findings contribute to a better understanding of the effect of several entrenchment pathways on firm performance. These findings imply that managerial entrenchment is not necessarily detrimental, as suggested by some governance theories. On the contrary, it can have a beneficial effect on wealth creation. Research limitations/implications: This study faces several limitations. The first appears in the sample size of its quantitative element. The second is related to the variables used to measure managerial entrenchment. The current research explores the effects of the most commonly used measures and some non-retained measures could be pertinent in verifying the assumed relationships. Originality/value: This analysis is one of the few studies conducted in the African countries that scrutinize the impact of managers’ entrenchment determinants (ownership, duality, age, and tenure) on firm performance

14

The Orthogonal Projection and the Riesz Representation Theorem

88%

Narita K. , Endou N. , Shidama Y.

Formalized Mathematics

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2015

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tom 23

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nr 3

243-252

EN

In this article, the orthogonal projection and the Riesz representation theorem are mainly formalized. In the first section, we defined the norm of elements on real Hilbert spaces, and defined Mizar functor RUSp2RNSp, real normed spaces as real Hilbert spaces. By this definition, we regarded sequences of real Hilbert spaces as sequences of real normed spaces, and proved some properties of real Hilbert spaces. Furthermore, we defined the continuity and the Lipschitz the continuity of functionals on real Hilbert spaces. Referring to the article [15], we also defined some definitions on real Hilbert spaces and proved some theorems for defining dual spaces of real Hilbert spaces. As to the properties of all definitions, we proved that they are equivalent properties of functionals on real normed spaces. In Sec. 2, by the definitions [11], we showed properties of the orthogonal complement. Then we proved theorems on the orthogonal decomposition of elements of real Hilbert spaces. They are the last two theorems of existence and uniqueness. In the third and final section, we defined the kernel of linear functionals on real Hilbert spaces. By the last three theorems, we showed the Riesz representation theorem, existence, uniqueness, and the property of the norm of bounded linear functionals on real Hilbert spaces. We referred to [36], [9], [24] and [3] in the formalization.

15

Sufficient optimality criteria and duality for multiobjective variational control problems with B-(p,r)-invex function

88%

Antczak T. , Jimenez M. A.

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2014

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tom Vol. 34, no. 4

665--682

EN

In this paper, we generalize the notion of B-(p, r)-invexity introduced by Antczak in [A class of B-(p; r)-invex functions and mathematical programming, J. Math. Anal. Appl. 286 (2003), 187–206] for scalar optimization problems to the case of a multiobjective variational programming control problem. For such nonconvex vector optimization problems, we prove sufficient optimality conditions under the assumptions that the functions constituting them are B-(p, r)-invex. Further, for the considered multiobjective variational control problem, its dual multiobjective variational control problem in the sense of Mond-Weir is given and several duality results are established under B-(p, r)-invexity.

16

Generalized α-V-univex functions for multiobjective variational control problems

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Sharma S. , Choudhury S. , Jayswal A.

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2014

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tom Vol. 43, no. 3

403--420

EN

The purpose of this paper is to introduce a new class of _-V-univex/ generalized _-V-univex functions for a class of multiobjective variational control problems. Moreover, sufficient optimality conditions and Mond-Weir type duality results, associated with the multiobjective variational control problem, are established under aforesaid assumptions.

17

Le thème du double dans L’histoire exécrable d’un héros brabançon de Jean Muno

88%

Bizek-Tatara R.

Romanica Wratislaviensia

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2013

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tom 60

141 - 148

EN

The theme of duality, omnipresent in the writing of Jean Muno, is particularly discussed in the novel L’histoire exécrable d’un héros brabançon. The duality has various features and appears in various layers, beginning with the composition of characters, spatio-temporal dimension, narration and the language. This theme is inseparably connected with the recurrent motive of absence of personal and national identity (la belgitude).

18

The Ethical Duality in Sports: Social and Psychological Aspects of Transgender Participation

88%

Bal B.

Physical Culture and Sport. Studies and Research

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2011

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tom 53

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nr 1

5-9

EN

Historically the notion about the understanding of women has been patriarchal in nature. The postmodern world has an inclination to redefine social mores. The prevailing thought in the 20th and 21st centuries supports the same thesis. The transformation of attitudes appears to be a regular phenomenon in the understanding of the issue at hand, thereby enlivening the motif of unity between the two. Gender, transgender, sexuality, etc., are in a state of transformation, so that to interpret and reinterpret a state of understanding and re-understanding of the issue of participation in sports has multiple significations. Sport in the 21st century constructs inimitable challenges for trans-athletes. A broad spectrum of identities is included under the umbrella of transgender identity. Transsexual or transitioned athletes may pose the greatest challenge to equity in sex-segregated sport competition. The subject under deliberation has a large number of interpretations, all of which center on a need to ‘deconstruct’ the present structuration of acceptance of sex and gender terminology. There is certainly a need to think and contemplate in broader terms about the meanings that assess the well-defined boundaries between disciplines of research. The present thesis highlights a deconstructive stance.

19

Analysis of some dual properties in discrete dynamic systems

88%

Zhirabok A.

International Journal of Applied Mathematics and Computer Science

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2006

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tom 16

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nr 3

297-308

EN

The problem of duality in nonlinear and linear systems is considered. In addition to the known duality between controllability and observability, new dual notions and their properties are investigated. A way to refine these properties through an isomorphic transformation of the original systems is suggested.

20

Set-valued minimax fractional programming problems under -cone arcwise connectedness

88%

Das K.

Control and Cybernetics

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2022

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tom Vol. 51, No. 1

43--69

EN

In this paper, we consider a set-valued minimax fractional programming problem (MFP), where the objective as well as constraint maps are set-valued. We introduce the notion of ρ- cone arcwise connectedness of set-valued maps as a generalization of cone arcwise connected set-valued maps. We establish the sufficient Karush-Kuhn-Tucker (KKT) conditions for the existence of minimizers of the problem (MFP) under ρ-cone arcwise connectedness assumption. Further, we study the Mond-Weir (MWD), Wolfe (WD), and mixed (MD) types of duality models and prove the corresponding weak, strong, and converse duality theorems between the primal (MFP) and the corresponding dual problems under ρ-cone arcwise connectedness assumption.