Stupak, Viktor

Early stages of existence of electronic devices are considered: design stage and stage of early failures. At the design stage, works on evaluation of reliability of various variants of structure of electronic devices are carried out. At performance of the given works, help data by manufacturers of components are used. The important question is definition of failure rate of components during the moments of time further from time of publication of help data. The method of forecasting of reliability of components is offered. The method considers data by the manufacturer on change of failure rate of components during the moments of time after publication of help data. The stage of early failures of electronic devices is considered. Two models of dependence of failure rate on time for the given stage are analyzed. Methods of estimation of parameters of considered models and method of estimation of conformity of models with statistical data on failures are offered. Models of reliability of electronic devices are nonlinear, the numerical method of finding the parameters of models is therefore considered. The method provides carrying out of computing experiment. Bibl. 9 (in English; abstracts in English and Lithuanian).

Electronic devices are considered. In an interval between inspections periodic controls of serviceability are stipulated. The method of definition of accuracy of evaluation of efficiency index of devices is offered. Accuracy is characterized by an error caused by likelihood properties of parameters, influencing an index of efficiency. Error is defined by means of the computing experiment based on a method of statistical modeling. During experiment, 1000 realizations are received. Parameters influencing an index of efficiency are presented by random variables distributed under the rectangular law. Data of computing experiment show that half of width of confidential intervals 99 percent for an index of efficiency does not exceed 0.05 % (of size of a sample mean). Values of factor of variation do not exceed 0.60 %, and the error of evaluation of efficiency index does not exceed 1.80 % (of size of a sample mean).

Electronic devices inspected by using built–in test equipment are analyzed. The method of calculation of efficiency of devices for a case of unsteady Poisson flow of failure is offered. The method is based on estimation of the bottom and top limits for values of efficiency on analyzed interval of exploitation. For this purpose, efficiency of devices for corresponding Poisson flows of failures is calculated. A relative error of definition of efficiency value is defined. As an estimation of an error, its maximal value is used. Computing experiment according to the given error is executed. Experiment considers really possible values of the parameters influencing efficiency of the device. Results of experiment show that the maximal relative error of an estimation of a parameter of efficiency does not exceed 6.5 % .

Electronic devices which that are inspected by using built-in test equipment are considered. The method of ensuring requirements of efficiency index of devices is analyzed. It is shown that the index of efficiency depends on simple index of reliability: mean time between failures and mean time of restoration. The method of ensuring requirements of time between failures provides distribution of serviceability requirements between parts of the device. The opportunities of exception of some failures from the general flow, multifunctional nature of device are taken into account. The method of ensuring requirements of mean time of restoration provides an estimation of separate components of the given index. The expediency of development of complete sets of stocks of components is considered. The question of necessity of specifying stocks of components according to the results of exploitation of devices is analyzed.

Informatikos profilio dalykai fakultete dėstomi I ir II kursuose. Dalykų programose, nagrinėjant informacinių technologijų taikymo kriminalistikoje galimybes ir perspektyvas, analizuojami fotoroboto (kompozicinių portretų) sudarymo programų ypatumai. Nagrinėjamos kompozicinių portretų sudarymui naudojamos kompiuterinės programos, programų paskirtis. Pateikiami portretų sudarymo procedūrų apibrėžimai. Analizuojamas portretų sudarymo programose naudojamas vaizdo morfingas. Nagrinėjamos trimačių kompozicinių portretų sudarymo galimybės. Pabrėžiama svarba metodų, naudojamų organizuojant darbą su liudytojais.

In the programs of the subjects on computer science, in studying questions of opportunity of application of information technologies in criminalistics, features of software for face modeling are analyzed. The software for face modeling and their purpose are considered. Definition of standard procedure for face modeling is provided. New opportunities of software for face modeling in comparison with standard procedure are determined. Morphing for images used in software is analyzed. The opportunities of software for three – dimensional face modeling are considered. The important value of methods of the organization of work with witnesses is emphasized.

Electronic devices of control systems are analyzed. Aver-age time of restoration of electronic devices is considered. The method of an evaluation of a part of the given index that describes average time of expectation in queue of components for restoration, is offered.

The restorable electronic devices are investigated. The system of ensuring with components used for realization of repair of devices is analyzed. The method of defining rational structure of supply system of components of devices is offered. A number of possible structures of supply system of components are generated. The case of presence of one, two and three complete sets a component in each of structures is considered. The components with three levels of technological complexity are analyzed. Definition of rational structure of supply system of components is carried out in view of restrictions on values of an index of sufficiency of stocks or an index of expenses. The index of expenses describing cost of stocks of components is considered. As an index of sufficiency of stocks of components, probability of sufficiency of stocks, index of availability of stocks, and average time of the delay in realization of the application for components are applied. The method of defining rational structure is carried out according to the developed algorithms.