Метод иерархического макромоделирования в задачах анализа линейных электрических эквивалентных схем в САПР
In this paper we propose a method of modeling linear equivalent electrical circuit formed by artificial elektroanalogy based on their two-stage reduction. In the first step of the simulation model of each sub-circuit of the initial scheme formally converted into a macro model that reflects only its expressions like "input-output". In the second stage model consisting of macro models, is converted to the next hierarchical level of the macro model. The mathematical apparatus of macro-modeling is based on the inversion in the analytical form of polynomial regular high degree matrices. The proposed method can significantly reduce the complexity of modeling and multivariate analysis of large equivalent electrical circuits.
System for thermal design on chip- and board-level of electronic components is introduced. It is integrated with Mentor Graphics CAD and consists of three subsystems: thermal design in IC Station; thermal design in Expedition PCB; thermal measurement for verification of temperature modeling results.
Are the main features of CAD software used in the development of equipment using FPGA. Is an example of job creation projects FPGA. Discusses some common problems and suggest ways to address them.
The transient-current curves recorded for molecularly doped polycarbonate are theoretically studied with a version of the time-of-flight technique with a variable thickness of the generation zone. A mixed-carrier-transport model was used, having been proposed in the literature as an alternative to the viewpoint that treats a plateau as an artifact of the optical version of the time-of-flight technique with surface carrier generation. A program for numerical calculation is developed for the model, with the hole transport being dispersive in the generation layer and Gaussian in the rest of the polymer. The model parameter values are selected according to results of independent measurements. It is shown that the mixed-transport model does not explain the experimental observations.
The automatic electro-thermal simulation has been implemented in Mentor Graphics PCB Design Flow. New program-dispatcher TransPower has been developed to control the electro-thermal calculation process, combining the programs of the electric (Analog Designer) and thermal (BETAsoft) simulation into a single cycle. As a result, the labor consumption and the PCB electro-thermal simulation time have been significantly reduced, the accuracy and reliability of calculations have been improved and the human errors have been eliminated.
Automatic electro-thermal analysis is included into Mentor Graphics PCB Design System. The method of simultaneous iteration is used for board-level electro-thermal simulation. New software tool named TransPower is introduced to couple the electrical (Analog Designer) and thermal (BETAsoft) simulators. The design procedure is fully automated, human errors are eliminated, simulation time is significantly decreased, while accuracy and reliability are increased.
A model for organizing cargo transportation between two node stations connected by a railway line which contains a certain number of intermediate stations is considered. The movement of cargo is in one direction. Such a situation may occur, for example, if one of the node stations is located in a region which produce raw material for manufacturing industry located in another region, and there is another node station. The organization of freight traﬃc is performed by means of a number of technologies. These technologies determine the rules for taking on cargo at the initial node station, the rules of interaction between neighboring stations, as well as the rule of distribution of cargo to the ﬁnal node stations. The process of cargo transportation is followed by the set rule of control. For such a model, one must determine possible modes of cargo transportation and describe their properties. This model is described by a ﬁnite-dimensional system of diﬀerential equations with nonlocal linear restrictions. The class of the solution satisfying nonlocal linear restrictions is extremely narrow. It results in the need for the “correct” extension of solutions of a system of diﬀerential equations to a class of quasi-solutions having the distinctive feature of gaps in a countable number of points. It was possible numerically using the Runge–Kutta method of the fourth order to build these quasi-solutions and determine their rate of growth. Let us note that in the technical plan the main complexity consisted in obtaining quasi-solutions satisfying the nonlocal linear restrictions. Furthermore, we investigated the dependence of quasi-solutions and, in particular, sizes of gaps (jumps) of solutions on a number of parameters of the model characterizing a rule of control, technologies for transportation of cargo and intensity of giving of cargo on a node station.
Generalized error-locating codes are discussed. An algorithm for calculation of the upper bound of the probability of erroneous decoding for known code parameters and the input error probability is given. Based on this algorithm, an algorithm for selection of the code parameters for a specified design and input and output error probabilities is constructed. The lower bound of the probability of erroneous decoding is given. Examples of the dependence of the probability of erroneous decoding on the input error probability are given and the behavior of the obtained curves is explained.
Event logs collected by modern information and technical systems usually contain enough data for automated process models discovery. A variety of algorithms was developed for process models discovery, conformance checking, log to model alignment, comparison of process models, etc., nevertheless a quick analysis of ad-hoc selected parts of a journal still have not get a full-fledged implementation. This paper describes an ROLAP-based method of multidimensional event logs storage for process mining. The result of the analysis of the journal is visualized as directed graph representing the union of all possible event sequences, ranked by their occurrence probability. Our implementation allows the analyst to discover process models for sublogs defined by ad-hoc selection of criteria and value of occurrence probability