Software & Systems

Articles of journal № 3 at 2012 year.

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31. Solution of simultaneous polynomial equations on a computer [№3 за 2012 год]
Author: Лёзин И.А.
Visitors: 10066
The article offers the accelerated algorithm of Groebner bases search used in the course of solution of simultaneous polynomial equations. The proposed algorithm considers the issue of word size overflow and incorrect computations in the course of calculating on the computer. The classical Buchberger's algorithm and the updated Faugere's algorithm require a lot of steps; meanwhile they do not contain any additional actions on correction of floating point numbers computations that causes some errors and incorrect computation of simultaneous equations roots and irrational factors. The new algorithm by several times reduces the number of operations of polynom quantity reduction, does not store all possible pairs of polynoms and does not check them for the fact that one can be expressed in terms of the other. The algorithm proposed in the article operates only with that number of polynoms which are now a basis. The basis is expanded if none of the polynoms represented in it can be represented in the form of combination of the other polynoms of this basis. Otherwise, the extra polynom shall be removed from the basis that helps avoid overgrowth of the basis and excess operations with this polynom. In order to avoid the problem of incorrect computations because of the word size of the computer the algorithm envisages post-check. If any of the polynoms is reduced, then the initial polynom should be represented by the combination of the reduced polynom and the rest of the basis polynoms. If the values of coefficients of the equal monoms do not coincide after that, then the coefficients of the reduced polynom require correction by the error size.

32. Study of approximative possibilities of radial-basic network with orthogonal polynoms [№3 за 2012 год]
Author: I.V. Lyozina
Visitors: 7909
The article describes set up of the problem of approximation, provides rationalization for possibility to use the radial-basic neural network as an approximator of probability density function, gives the approximating statement for this network and statement for objective function, by means of which selection of basic function parameters and weight values is done. Besides, this article considers the possibility to use not only canonical Gaussian functions in the course of approximation of probability density function with a radial-basic network, but also sigmoidal functions, power functions and orthogonal polynoms of Legendre, Chebyshev of I and II kind, Laguerre and Hermite, and gives the relevant formulae. It compares the accuracy of approximation by means of computation of mean-square deviation. Approximation of probability density of Simpson and Rayleigh with a radial-basic network with sigmoidal, power functions as well as polynoms of Legendre, Chebyshev of I and II kind, Laguerre and Hermite are given as examples. At the end there is a recommendation to use the radial-basic network with polynoms of Legendre, Chebyshev of I and II kind as basic functions in case of increase of neurons number in the buried layer, because this network allows lower values of mean-square deviation than the one with canonical Gaussian functions to be achieved.

33. Navigation algorithms at the outer surface of international space station model [№3 за 2012 год]
Authors: Maltsev A.V., Mikhaylyuk M.V.
Visitors: 9803
Spaceman moves along ISS outer surface with help of special rails. Station is large, and in order to provide effective and safe movement it is necessary to solve navigation problem, e.g. designing the best route between start and target rails. This article offers route search algorithms according to criteria of minimum length and complexity between two given rails. The article reviews calculation of one or all possible routes that meet selected criteria. Search of a route is made with flow chart, which presents rails in the form of peak and ribs reflect the ways of passing between two neighbored rails. The solution involves oriented sub flow chart, where any route between start and final peaks presents the shortest one (or the least difficulty to pass it) in initial chart. Such algorithms can be used in implementation of navigation systems for simulation training facilities provided for spacemen. Use of such systems in the training facilities increases training effectiveness for those who work outside of station. This article illustrates navigation system in video training facility based on mentioned algorithms. The constructed route between two rails shall be highlighted with specified color. In addition, the article discusses issue related to the future of training facilities concerning development of system that can use virtual reality technology (virtual reality helmet, computer gloves) and navigation system. (The work is supported by RFBR, grant No 10-07-00317).

34. Tablet computer for outfit of the industrial enterprise workplaces [№3 за 2012 год]
Author: Матвеев А.И.
Visitors: 8994
There are two variants of the development of a portable computer engine operated on the basis of the motherboard as a desktop computer or as a portable computer (laptop). In consequence of the devices’ characteristics analysis, which is made on the data obtained during assembly, the choice is made in favor of the computer engine, working on the basis of the motherboard of a desktop computer. Created Tablet Computer is a mobile and is powered by a rechargeable battery. It causes to changes in all motherboard power system and eliminates to use the standard power unit. Power supply of the created Tablet Computer is based on the PWM generator. This method is easy to implement because of the large variety of MAXIM's chips and ISL (possibility of the programmatic control of the voltage level), the long hardware component base as of PWM-generating chips as well as several field transistors in a single package. The matrix (display) of the portable computer (laptop) is also used; the image is transmitted to the matrix through the DVI-output. The solution of a number of technical problems ensures compliance with the required functional characteristics and cost performance, which allows you to equip the required number of concerned industrial enterprise workplaces.

35. Traffic control models in traffic jam condition [№3 за 2012 год]
Authors: T.I. Mikheeva, S.V. Mikheev
Visitors: 9508
Transport stream is a controlled object in the intellectual transportation system. Such transport stream behaves stochastically, it is unstable and its features can vary in time. Continuing stream can be divided in the following traffic conditions: free stream, group stream and intensive stream. Free stream has low stream intensity. In case group stream is characterized by hindrance to traffic, the traffic is unstable; forming of such traffic groups can lead to loss of speed and traffic intensity, which means intensive stream. When the traffic density grows to the critical point, (road congestion density) the intensity drops down from the value of traffic handling capacity to zero. The area of critical density can contain point of function discontinuity V=f(k), which leads to abrupt change of the traffic speed. Little growth in traffic intensity can lead to a situation when the car queue is not able to fit into the space interval and therefore it blocks road intersection. Unstable traffic stream in relation to traffic handling capacity and spread of the stream disturbance leads to the break of its characteristics and fluctuation of amount of vehicles results into unstable traffic arrangement in relation to traffic handling capacity and development of bifurcation point Catastrophism was selected, models provided by this theory help to develop road traffic models, which include loss of stability, discovering factors that influence abrupt change of characteristics based on catastrophe parameters, construction and study of the model. Recognition, prediction, dissolution and prevention of road congestion conditions presents vital problem in the management of traffic streams.

36. Neural models of heterogeneous spatial coordinated data [№3 за 2012 год]
Authors: T.I. Mikheeva, Сапрыкин О.Н., S.V. Mikheev
Visitors: 9262
Vehicle park grows much faster than the road construction work pace and it creates the need for use of intellectual transportation system in order to increase management efficiency of transportation infrastructure in the urban area. Intellectual transportation systems are required that can embrace heterogeneous array data and use neural and geoinformational technologies with information support and high performance of the management system. Performance means reduction of crush rate and increase of traffic handling capacity concerning transportation network. Transportation infrastructure presents a complex system of interacting units involved in transportation system, technical facilities involved in traffic control and traffic stream itself. Analytical geoinformational subsystems integrate spatial coordinated data and methods that help to search information related to geographic nature, properties and relations between objects. Search of hidden consistent patterns in spatial coordinated data uses certain property of neural networks, which approximates any parameter with given accuracy. Transportation infrastructure ontology contains substance groups with close context dependent semantic links. Each ontology group is provided with data pre-processing technique that transform different input data array into output form which can provide task solution using neural networks. Given optimum multilayer perception architecture helps to solve any task. It shows sufficiency of one hidden layer and designed technique is provided for discovering of optimal number of neural elements in the hidden layer based on complex usage of external criteria and mean square deviation values of dependent parameters. The technique implementing construction of double multi-row neural network with active neural elements provides construction of nonlinear structure for multivariable regression model.

37. Mathematic model of the user Network-on-Chip [№3 за 2012 год]
Authors: Mosin S.G., Хассан Мд Муид, Тухтамирзаев А.Ю.
Visitors: 7980
Microelectronics development provided implementation of complex electronic systems in integrated-circuit form. CAD systems, integral technologies and design cycle during design of electronic system are selected to reduce time of their creation, increase reliability and quality of the final product. The effectiveness of the design process can be improved with different approaches, e.g. SoC – system on a chip, SiP – system in a package, MCM – multi chip module etc. For design of complex MPSoC – Multiprocessors System on a Chip it was provided NoC technology – network on a chip. Architectures of specialized MPSoC applications include numerous heterogeneous computing cores and memory modules. Each core provides a limited set of applicable functions. Such projects can be provided with simple inter-core communication. NoC technology is used for design of communication environment that provides communication between different system modules. NoC consists of routers that are physically connected with each other. Each computation core and memory blocks are connected to NoC by means of interface to the network (RNI-interface). In general case, NoC technology suggests the use of homogeneous topology – the grid, which provides connection of the same number of cores to each switch that form the domain. Domains in the system interact and they represent a regular structure. Alternative solution presents usage of heterogeneous topology; this fact assumes consideration of specific core features during design stage of the designed system. Number of routers and switching method are selected with the purpose of minimization of signal latency, chip size and power consumption. Heterogeneous topology helps to design specialized applications with minimal versatile properties. There is provided mathematical model of the user network-on-chip (NoC). There is provided search shortest path in the flow chart. Obtained outputs of algorithm operation for NoC topology optimization are provided.

38. Computing and modeling of fuzzy Cauchy problem using virtual perspective method [№3 за 2012 год]
Author: Myshev A.V.
Visitors: 8068
The work describes computing and modeling of fuzzy Cauchy problem using virtual perspective method with limitations, closedness and indeterminancy. It was investigated dynamic evolution of space objects within predicative model of bounded problem N – mass body using methods of standard computational mathematics and virtual perspective method. Obtain results showed that virtual perspective method was more effective and advanced in comparison with traditional simulation models. Computational modeling of this problem using virtual perspective method it is described on information modeling language. In this case the problem is defined and set as a discrete dynamic information system, specified at the set of nodes of coordinate and perspective arrays. Copmputing systems present character strings and its compositions as a information prototype of computing environment and its elements. Modeling in the virtual environment is characterized by following specifics. First, computation process creates dynamics of related image links (RIL) in modeling technologies. Second, information interaction mode and relations of the virtual objects in the model environment in the form of RIL conditions and real conditions of simulated problem, is reflected in coordinate nodes. This array is a geometry pattern of active memory of the computation environment. It was used two types of discrete sampling of the formal evolution operators for the modeled problem; they were used for RIL construction that corresponds to dynamics equation of the Cauchy problem modeling. Two patterns for RIL construction were shown in computing modeling of the fuzzy Cauchy problem. First model was constructed using Runge-Kutta techniques, and the second one was constructed using Adams techniques. Currently, in computing modeling technologies these methods were studied and examined best of all. For the fuzzy problems, related image links according to any variable of the evolution operator were considered as set of projections of the local information dynamic system in the basic array nodes.

39. Techniques provided fof valnerabilities reduction in special real time software [№3 за 2012 год]
Author: Нархов К.Г.
Visitors: 12953
This article is dedicated to automation of a programmer’s work, particularly in the area of vulnerabilities reduction and bugs in the program code. The article reviews details of the program design in technical facilities of automated code generation for special software (TFACG SS) and use of library contained in TFACG SS that reduces potential vulnerabilities appearing in new programs. The author provides taxonomy of typical vulnerabilities in real time programs, he makes review of each class of vulnerability, how often and why does the vulnerability occur, and its prevention using TFACG SS facilities. Some potential vulnerabilities take in account configuration of real time operating system. Taxonomy of vulnerabilities was made with a static estimating device and set of real time source code designed by Institute for Scientific Research of Russian Academy of Sciences. Set of the source codes includes 204 of the program modules (more than 111700 lines). The article finishes with example of reduction of potential vulnerabilities in real time source code generation program (PVSC RT), which is a part of TFACG SS. The article shows method of reduction of vulnerabilities using standard program patterns provided by TFACG SS, this method repaired all vulnerabilities that were found by static estimating device in PVSC RT. The library expansion for standard TFACG SS patterns and the supplementation of the static analyzer rules, which will include tests and conditions specific for real time operating system, are the main prospects of solutions presented in the article.

40. Microbenchmarks for microprocessor RTL-models performance assessment [№3 за 2012 год]
Author: Николина Н.В.
Visitors: 6113
An approach for evaluating and monitoring performance of the microprocessor on design stage is considered. The technique to estimate performance of separate blocks is offered, any potential influence of others is thus ignored. We propose a test suite for evaluating performance of microprocessor RTL-models (Register transfer level). The test set consists of the short programs (microtestbenches) directed on performance evaluating of separate blocks. A choice of test set for different modules is realized on taking into account features of its work. An article presents a number of test situations for evaluating such modules as instruction fetch and dispatch buffer (IFDB), floating point unit (FPU) and memory management unit (MMU) for MIPS-like architecture. For the analysis of run time performance counters are used, which are the parts of control coprocessor registers of microprocessor. Automation for creating test cases, regression performance measurement and visualization of performance evaluation results are proposed. During reasonable time the test system allows to receive results of a performance evaluation and to compare it with results of the previous versions of RTL model, or with reference values. Also the impact of performance measurements on architecture of future chip is considered. The possibility to investigate the influence on microprocessor performance of such factors as changing memory frequency is shown. The results of measurements are shown on example of performance evaluation of superscalar microprocessor which is developed in SRISA RAS. The results were confirmed on final crystal.

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