Informatica

A fault-tolerant software unit is composed of N≥2 diverse member units, usually developed by N separate teams, and an execution environment. The development process employs diversity requirements, communication protocols, and inter-team isolation rules to promote the greatest possible independence of team efforts and diversity among their products. The principal models, specification, building, evaluation, and system integration of fault-tolerant software are discussed, and goals for future work are suggested.

In the paper a general approach to identification of non-linear autoregression processes in the class of parametric and non-parametric mathematical models is formulated. With the help of mathematical simulation the estimates of the processes of this class are studied: a nuclear estimate, an estimate of least squares projective estimates. Some statistical properties of these estimates are indicated.

The weight coefficients calculation algorithm for, an autoregressive random field, existing in a two-dimensional space and time, is proposed.

This paper discusses the inversion of linear periodically time-varying (LPTV) digital filters using the idea of converting the LPTV filter to the block time-invariant filter. Explicit expressions are given to determine the inversion of LPTV filters. Controllability, observability and stability of the inversion of LPTV filters are discussed.

The present paper considers the problem of general estimation of static model parameters and systematic measurement errors. The general estimation algorithm is based on static model linearization and on the least-squares method. The efficiency of this algorithm is illustrated by means of computer-aided digital simulation. The obtained equations and the algorithm of general estimation of static model parameters and systematic measurement errors can be applied for the solution of different practical problems. Estimatibility conditions must be satisfied in all cases.

In the papers (Pupeikis, 1988a, b; 1989a, b, c) the problems of efficiency determination, stopping and increase of the effectiveness of asymptotically optimal recursive algorithms are considered respectively by means of estimating time delay in an object and also introducing their robust analogues, stable to outliers in observations. The aim of the given paper is the development of the robust method for a determination of the model order on the basis of determinant ratio. The three methods forming the initial moment matrices are considered. By the first method the elements of the matrix, being the corresponding values of the sample covariance and cross-covariance functions, are calculated by classical formulas. In the case of the second method the same elements are substituted by their robust analogues. The third method is based on an application of auxiliary variables. The results of numerical simulation on a computer (Table 1) indicate the advisability to apply the robust method for determining the model order in the presence of outliers.

Data processing programs combine computations with navigation in a data base. Methods of the structural synthesis of programs are oriented towards construction of computing programs, and the methods of synthesis of relations are oriented towards construction of (logical) navigation paths. An approach to the integration of methods of the structural synthesis of programs and methods of the synthesis of relations is proposed. This approach is based on a computation model (a set of formulas), describing both computations and navigation paths. The sound and complete system of inference rules for the class of formulas, used in such computation models, is given.

In this report an expert system AKU for diagnostics in acupuncture is described. The injured vital energy channels can be diagnosed using three independent methods: inquiring, Ryodoraku test and Akabane test. The inquiring is constructed as a set of trees whose internal vertices are questions while the leaves are the symptoms of diseases. The production rules describe the correspondence between the symptoms and the state of vital energy “qi” in the channels. AKU is realized by IBM PC computer and used for acupuncture treatment. The program is coded in Turbo Prolog.