Journal:Informatica
Volume 4, Issues 3-4 (1993), pp. 351–359
Abstract
The universal structural type of information units-entities is presented the paper. This approach can be recommended for data base modelling at the conceptual and relational levels.
Journal:Informatica
Volume 4, Issues 3-4 (1993), pp. 335–350
Abstract
This paper is devoted to research aspects of the convergence rate of conservative difference schemes (d.s.) with time-adaptive grids in cases, where a space grid is irregular and the third boundary-value problem is considered for one-dimensional linear parabolic equations. The unconditional convergence of created d.s. is proved in a C-metric at the rate O(h2+τ01/2).
Journal:Informatica
Volume 4, Issues 3-4 (1993), pp. 322–334
Abstract
An attempt to explain a basic nature of the information processing hierarchy in Organizational Systems is made. A framework for intelligent information processing at managing is presented. Organizational System (Enterprise) as the framework of so called elementary management cycles is decomposed. The structure of elementary management cycle (EMC) is presented and its properties discussed. A taxonomy of information processing hierarchies is based and presented. Such considerations seems to be important for the design of intelligent management information systems.
Journal:Informatica
Volume 4, Issues 3-4 (1993), pp. 312–321
Abstract
The hierarchy of information units and interactions in managing of Organizational Systems is ruther complicated. Interactions between departments of different levels of hierarchy are named “co-ordination” (Mesarovic, Mako, Takahara, 1970). This paper deals with the coordination as the “vertical” informational interfaces between the units called “elementary management cycles” which compose the structure of managing process.
The taxonomy of co-ordination processes presented in this paper is based on the decomposition of information processing at managing in so called the Space of Processes (Gudas, 1991).
Journal:Informatica
Volume 4, Issues 3-4 (1993), pp. 303–311
Abstract
A classification of teaching forms is introduced. One-to-many (group) distance teaching forms are discussed with respect to the means, which are used in the programming teaching process. The role and the possibilities of electronic mail in this process is discussed. The experience of Lithuanian Young Programmers' School by Correspondence is referred to.
Journal:Informatica
Volume 4, Issues 3-4 (1993), pp. 295–302
Abstract
An algorithm testing methodology used in the programming teaching process is presented. Turbo Pascal system is used. Due to systematic use of some features of this system a pseudo-direct execution of algorithms expressed by Pascal procedures and functions may be ensured. The need to use data read and write statements is excluded. This enables a novice learner to concentrate himself on the main actions of an algorithm.
Journal:Informatica
Volume 4, Issues 3-4 (1993), pp. 277–294
Abstract
This paper is devoted to the new approach in the stability analysis of steady state solutions. Two important nonlinear optics problems are used as model problems. Stability properties of classical and splitting difference schemes are investigated. Some numerical results are given.
Journal:Informatica
Volume 4, Issues 3-4 (1993), pp. 267–276
Abstract
A fail-safe sequential machine is one that produces error signal when failures occure in the machine. This paper presents a new method of realization of fail-safe sequential machines under the following assumptions:
1) failure is caused by faults of logical and memory elements in the machine,
2) output of faulty elements is stuck at one or zero.
A feature of this method is that an input inversion is used for additional state assignment and this additional state is used for detection of faults of elements.
Journal:Informatica
Volume 4, Issues 3-4 (1993), pp. 255–266
Abstract
Control laws' design strategies in order to stabilize a class of linear delay-differential systems are developed by using the matrix measure. A new measure, the delay measure, is introduced in order to clarify and formalize the results.
Journal:Informatica
Volume 4, Issues 1-2 (1993), pp. 227–249
Abstract
This work was stimulated by investigations on Markow Renewal Processes. For finding analytic solutions (to compute the probabilities of certain states of the system) multivariate Laplace transforms can be used. Tables with correspondences of function and their transforms very rarely help to solve such problems.
In Chapter I number theoretical numerics are applied to compute the original function of a multivariate Laplace transform given. Starting with the complex multivariate inversion theorem the domain of integration is mapped onto the s-dimensional unit cube Gs. Using a periodization of the integrand new results concerning the vanishing of the multivariate Laplace transform in regard of the modified numerical inversion formula are shown.
In Chapter II two implementations are discussed: A method to implement a Manager-Worker Process (MWP) to reduce the idle times of the processors is presented and the tasks of the Manager and the Workers are defined. The numerical inversion using this method with STRAND88 has been implemented on a heterogenous workstation net. The MWP provided a good load balancing. Another implementation with C-LINDA has been done on a Shared Memory MIMD system. We also implemented a kind of MWP. Numerical experiments have shown that the decomposition of the problem is sufficiently.