Journal:Informatica
Volume 9, Issue 4 (1998), pp. 469–478
Abstract
The object of the present paper is to study certain subclasses Jp* (a,b,σ) and Cp(a,b,σ) of analytic p-valent functions, and obtain coefficient bounds and distortion properties for functions belonging to these subclasses. Further results include distortion inequalities and radii of close-to-convexity, starlikeness and convexity for these classes of functions.
Journal:Informatica
Volume 9, Issue 4 (1998), pp. 457–468
Abstract
Analysis of work of art may be treated as some sort of classification of information: does the work is really artistic or not. This article is an attempt to introduce some classification criteria, though the author understands that the problem is extremely delicate and complicated. Attractiveness of work of art is determined by its proportions. The screen of a computer by itself is a mechanism for arranging proportions, however it is not able to resolve the problem of proportions completely. By starting with the horizontal (or vertical), which touches the main element of the picture, a grid can be constructed. Other elements of the picture become interlocked with the grid. In this paper, a method of construction of proportional grids, which can serve as an implement to creation of art or as criterion of coherence, artistic value and style of works of art, is proposed. Variety of proportional grids can be great, and we can create its from grids of coordinated geometrical forms.
Journal:Informatica
Volume 9, Issue 4 (1998), pp. 449–456
Abstract
Language engineering encompassing natural language processing and speech processing became very important for a development of every nation in multilingual Europe. After the Council of European Union approved conclucions on linguistic and cultural diversity, tools and systems created for every European language are necessary to overcome language barriers and to use all languages in various spheres of human cooperation. The paper gives an overview and a consideration of language engineering in Lithuania.
Journal:Informatica
Volume 9, Issue 4 (1998), pp. 437–448
Abstract
This paper presents a parallel version of a Generalized Conjugate Gradient algorithm proposed by Liu and Story in which the search direction considers the effect of the inexact line search. We describe the implementation of this algorithm on a parallel architecture and analyze the related speedup ratios. Numerical results are given for a shared memory computer (Cray C92).
Journal:Informatica
Volume 9, Issue 4 (1998), pp. 425–436
Abstract
Principles of the framework called time series forecasting automation are presented. It is required in processing massive temporal data sets and creating completely user-oriented forecasting software where manual data analysis and a user's decision-making is either impractical or undesirable. Its distinct features are local extrapolation models, their active training, criterion of model performance assessment used in adding new examples to the model training set and in deciding on which one of a group of competing models consistent with the common training set performs best. A generalized algorithm for local model tuning on massive data series that can be run without human intervention is presented.
Journal:Informatica
Volume 9, Issue 4 (1998), pp. 415–424
Abstract
Comparative study of the recognition of nonsemantic geometrical figures by the human subjects and ART neural network was carried out. The results of computer simulation experiments with ART neural network showed well correspondence with the psychophysical data on the recognition of different complexity visual patterns: in both cases the patterns of medium complexity were recognized with the highest accuracy. On the contrary, the recognition of the patterns by their informative fragments demonstrated different recognition strategies employed by natural and artificial neural systems. For biological systems, it is necessary the presence of not only distinctive features in visual patterns but the redundant features as well for successive recognition. ART neural network ignores redundant features and recognizes visual patterns with equal accuracy whether the whole pattern or only the informative fragment of any completeness is present.
Journal:Informatica
Volume 9, Issue 4 (1998), pp. 401–414
Abstract
The sample-based rule obtained from Bayes classification rule by replacing unknown parameters by ML estimates from stratified training sample is used for classification of random observations into one of two widely applicable Gamma distributions. The first order asymptotic expansions of the expected risk regret for different parametric structure cases are derived. These are used to evaluate performance of the proposed classification rule and to find the optimal training sample allocation minimizing the asymptotic expected risk regret.
Journal:Informatica
Volume 9, Issue 3 (1998), pp. 387–395
Abstract
Laplace equations were used for modeling of electrotonic potential in three-dimensional isotropic double-space RC medium. Solutions of Laplace equations for the case of rectangular current pulse stimulation using spherical electrode we obtain using Laplace transforms in imaginary space. Solutions in original space we got using numerical invert Laplace transform. It showed that the rising front of the transmembrane potential becomes less steep in regard to rising radius of the stimulating electrode and asymptotically reaches single-dimensional cable case (evenly distributed RC-circuit). The steady state value of transmembrane potential decreases with the increasing distance from stimulating electrode. It remains always positive when stimulus current is negative.
Journal:Informatica
Volume 9, Issue 3 (1998), pp. 365–386
Abstract
We discuss an age-sex-structured population dynamics deterministic model taking into account random mating of sexes, females' pregnancy and its dispersal in whole space. This model can be derived from the previous one (Skakauskas, 1995) describing migration mechanism by the general linear elliptic operator of second order and includes the male, single (nonfertilized) female and fertilized female subclasses. Using the method of the fundamental solution for the uniformly parabolic second-order differential operator with bounded Hölder continuous coefficients we prove the existence and uniqueness theorem for the classic solution of the Cauchy problem for this model. In the case where dispersal moduli of fertilized females are not depending on age of the mated male we analyze population growth and decay.
Journal:Informatica
Volume 9, Issue 3 (1998), pp. 343–364
Abstract
This paper describes a preliminary algorithm performing the mapping of sound to music score. Our procedure is constructed over signal-extracted energy and fundamental frequency traces alone. The algorithm is tested on real songs of average complexity. Although results seem to be promising, their detailed examination reveals some shortages of our approach as well as the set of application specific problems. It appears that musical analysis can not be entirely dissociated from phonetic processing. Further work should be oriented towards integration of knowledge of music as well.