Bulletin of the Polish Academy of Sciences. Technical Sciences
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The paper examines decision tables as a requirements specification technique. In our approach, state machines model the dynamics of reactive systems, whereas decision tables provide a knowledge base defining their behaviour in each state. We apply rough set theory, which provides a methodology of decision table analysis, to formally verify and minimize the decision tables. The resulting tables can...
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The car switching data concern car purchases 1979 in USA. They form 16 x 16 data table (Xij) which shows how many owners of a car belonging to i-th segment in a given car classification bought a car belonging to the i-th segment (i, j = 1, . . ,16). The paper is devoted to compare various methods looking for latent trends or regularities. First (section 3) it is shown what can be done when comparing...
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The aim of this paper is to perform dual homogenization of Koiter's shell model, previously studied in refs. [1], [2]. In Part I the shell model with a periodic structure is introduced and the [gamma]-convergence theorem is formulated. This theorem justifies the asymptotic approach used in [1].
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Distribution of electromagneto-elastic fields, in a vicinity of tip of conducting crack, propagating with a constant velocity in elastic dielectric, is investigated throughout the paper. Description of electromagneto-elastic fields bases here on quasilinear approximation of nonlinear Dixon-Eringen model of elastic dielectric. This part includes general formulation of the problem and construction of...
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This paper examines the accuracy of a space marching formulation for solving two-dimensional inverse heat conduction problems. The parameters that have a major influence on the solution such as time step size, measurement errors and Biot number are investigated. The temperature and heat flux on the surface of a body are estimated on the base of the temperature measurement at a number of sensors located...
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An inverse control volume code is developed for the study of transient boundary inverse heat conduction problems. A nonlinear numerical formulation of the Weber method is extended to relatively high noisy input data. The control volume method is combined with a digital filter method for solving the hyperbolic approximation of the inverse heat conduction problems. The results show that such combination...
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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.
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Distribution of displacements and mechanical part of stresses generated by electromagnetic field, in a vicinity of a tip of conducting crack propagating in an elastic dielectric, is investigated throughout Part 11 of the paper. Basing on functions, which describe electromagnetic forces determined in Part I, solution of the corresponding initial boundary problem for the Lame equations is constructed...
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A new class of positive 2D continuous-discrete linear models is introduced. Sufficient conditions for 2D continuous-discrete linear model to be a positive system are established. The solution to the positive 2D continuous-discrete model is derived. Necessary and sufficient conditions for the local reachability of the positive 2D system are established. The minimum energy control problem for positive...
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The present definition of nearest ordinary set of a fuzzy set is not suitable in many cases. An improved as well as generalized definition is suggested and studied.
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In this paper we examine the issue of controllability for positive linear 2D systems. We look at the connections between reachability, reach ability from zero boundary conditions, and the rank criterion for controllability for systems in which both the state and controls are constrained by practical considerations to lie in a positive orthant. While these concepts are equivalent for unconstrained...
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Problems dealt with an inverse filtering in the time domain are the general objective of the study. A prerequisite to obtain a satisfactory inverse filtering result of a noisy output signal for a nonminimum-phase system is the stabilization and regularization of the inverse filter. In the paper, two algorithms have been proposed for inverse filter stabilization, both leading to the noncausality of...
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A new class of weakly positive singular continuous-time linear is introduced. A standard system which is equivalent (has the same solution) to the singular (regular) continuous-time linear system is derived. Necessary and sufficient conditions are established under which a weakly positive singular continuous-time system can be transformed by the strict equivalence to a positive system. Some properties...
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The paper deals with a new formulation of Hamilton's principle for perfect fluids. The discussion is confined to the Lagrangian description of fluid motion that is based on the positions of fluid particles. The derivation of the principle is compared with earlier treatments of the problem existing in literature of the subject. It is the author's impression that the proposed solution is better than...
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In this paper a concept of a three-scale modelling of behaviour of materials is extended to stochastic phenomena. The main element of the three-scale description consists in a dimensional reduction procedure. Consequently, evolution of probability densities obtained as a result of applying such a procedure is considered. Connections between the probability densities on different levels of description...
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Problems connected with applications of the rough set theory to identify the most important attributes and with induction of decision rules from the medical data set are discussed in this paper. The medical data set concerns patients with multiple injuries. The direct use of the original rough set model has led to finding too many possibilities of reducing the input data. To solve this difficulty,...
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This paper presents a new approach to A/D converters with [sigma delta] modulations using switched transconductance amplifiers. The layout of the [sigma delta] structures with current mode blocks, transconductance amplifiers and input capacitors are designed using COMPASS DESIGN AUTOMATION Development Tools in 0.8 MICRON technology. The extraction of the modulator was made from this layout and the...
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A new, general method is presented for the determination of Lie symmetry groups of integro-differential equations. The exhibited method is a natural extension of the famous Ovsiannikov method developed for differential equations. The method leads to significant applications for instance to the Vlasov-Maxwell equations, which are integro-differential type irreducible to differential equations.
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Grains in form of circles are connected by elastic joints. Grains expand thermally, but do not deform elastically. The joints deform elastically, but do not expand thermally. The special situation is considered when the composite consists of only two kinds of grains, first kind with larger and the second kind with smaller expansion coefficient. The grains are randomly distributed in the specimen....
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In the paper the previous results of the author on the surface waves in a nonhomogeneous isotropic elastic semi-space [4], [6] has been extended to an anisotropic semi-space. It is shown, that the velocity and the amplitude of the surface waves in the non homogeneous anisotropic elastic semi-space, with non homogeneity depending on a semi-space depth, are the analytical functions of the wave number...
