Интерактивный учебно-исследовательский комплекс для моделирования процессов в вычислительных системах
This article aims at the improvement of the engineer training quality in the field of "computer Science and engineering" using on-line and blended learning technology. We consider studying of modern computers architecture as an example. The complexity of the modeling object, the multi-faceted process of studying the computer architecture, the limited period – are the factors that determine the difficulty of the problem. A computer simulator allows you to explore the stages and features of the calculation process in dynamics with the necessary detail. It can't be done any other way. Also, computer modeling creates a risk-free environment that allows you to safely and repeatedly apply and analyze possible scenarios, decomposition of computer nodes and configuring its components for different modes of operation. This is either impossible to perform on real devices or may result in computer failure under students’ inept actions. The paper discusses the problems of the computer units and devices simulating, the requirements for models in terms of solving educational and research problems. We propose a structure of the simulating complex, visualization methods of computer architecture components and principles of computer system device’s operation, algorithms descriptions of the modeling programs. Since the computer architecture implies a whole complex of concepts, including functional and structural organization, software and hardware interaction algorithms, the considered simulating complex consists of several simulators: step-by-step operation of the superscalar processor core; cache coherence protocols in multiprocessor (multi-core) systems; algorithms for fast address translation with the help of Translation Lookaside Buffer (TLB); various technologies for multithreaded data processing; pipeline processing of the machine instructions stream; memory paging algorithms; cache mapping algorithms; cache replacement algorithms; etc. The main functions and features of each model are considered. An important advantage of the proposed simulating complex is the ability to vary the parameters of models of specific computer devices, which makes it possible to explore the resource/time characteristics of data processing by computer system devices.
Author proposes a new theory of virtual modeling of physical processes, which allows to obtain data enabling the designer of an onboard electronic means to build and see on the computer monitor a 3D image of the developed design. At the same time, physical fields obtained from virtual modeling of thermal and mechanical processes are superimposed on the design image. These fields enable you to define in which places of the actual design overheating, unacceptable deformations and accelerations on electronic components are possible.
The results are displayed in the form of: thermal fields of printed circuit boards and other load-bearing structures, acceleration field on electronic components, and fields of mechanical stresses and deformations of load-bearing structures of onboard electronic means.
In the work the author formulated requirements to the theory of virtual modeling of dissimilar physical processes in schemes and constructions, and developed the content of this theory.
The author shows that the basis of the developed theory is modeling of dissimilar physical processes with the use of mathematical analogies and topological graphs.
The paper describes the union of the physical processes in constructing the virtual model, which allows to conduct research jointly occurring electrical, thermal and mechanical processes in onboard electronic means considering their mutual influence.
The paper presents the approach of selection general architecture pattern and design tactics for the software project. Proposed method is based on the satisfying required software quality attributes. The domain ontology is defined along with the main concepts and structure. Base software architectural patterns and main design tactics were analyzed and as a result the problem of building software architecture with required quality attributes has stated. As a solution, analytical model of selecting necessary tactics has presented. The general approach to select the best software architecture pattern and tactics is defined and described with the example of preventive maintenance systems.
Historically, a typical embedded system has been designed as a control-dominated system using only a state-oriented model, such as FSMs. However, the trend in embedded systems design in recent years has been towards highly distributed architectures with support for concurrency, data and control flow, and scalable distributed computations. This implies that a different approach is necessary. We propose to use some dataflow computational model views to specify embedded systems, because it is a notation that covers the most relevant aspects of distributed computing. In this paper, we introduce a new computational model, known as OAA (Object-Attribute Architecture) and present the general characteristics of an OA-methodology to support the design and simulation of distributed computing systems. The matrix multiplication algorithm in the object-attribute distributed computing environment has been used to validate our methodology. The preliminary evaluation results show the feasibility of the OA approach.
This book constitutes the refereed proceedings of the 4th International Conference on Tools and Methods for Program Analysis, TMPA 2017, Moscow, Russia, March 3-4, 2017. The 12 revised full papers and 5 revised short papers presented together with three abstracts of keynote talks were carefully reviewed and selected from 51 submissions. The papers deal with topics such as software test automation, static program analysis, verification, dynamic methods of program analysis, testing and analysis of parallel and distributed systems, testing and analysis of high-load and high-availability systems, analysis and verification of hardware and software systems, methods of building quality software, tools for software analysis, testing and verification.
In the paper, we describe a metamodel to represent dynamics of AADL-models. The metamodel allows to visualize step-by-step a process of models' behavioral aspects analysis. In particular, it essentially helps to debug behavioral specifications. In the paper, we consider examples of the metamodel usage to represent dynamics for the following two aspects of AADL-models: 1) simulation of a modelled system on the basis of a Behavior Annex specification; 2) failure modes and effects analysis on the basis of an Error Model Annex specification. We also present a stepwise visualization tool (engine and applications for both mentioned examples) that is implemented in MASIW framework for design of modern avionics systems.
This book constitutes the refereed proceedings of the 12th International Conference on Parallel Computational Technologies, PCT 2018, held in Rostov-on-Don, Russia, in April 2018.
The 24 revised full papers presented were carefully reviewed and selected from 167 submissions. The papers are organized in topical sections on high performance architectures, tools and technologies; parallel numerical algorithms; supercomputer simulation.
The aim of this article is to highlight the relationships between contemporary tendencies in the humanities (the new ontologies) and contemporary architectural practices. The author articulates the distinction between the optics of the «old ontologies» and the new ones. The ontologies considered to be new ones are flat, free from classical opposition between the whole and the parts and based on modality of possibility, but not obligation. Objects and practices traditionally referred to as architecture appear to be based on the principles of the «old ontologies». For them human being is an extraordinary object compared to others, the part-to-whole relationships appear to reflect either the superiority of the whole (society) or the superiority of the part (individual), finally, they are aimed at creating an “it has to be this way” picture. The new ontologies seem to be impossible to apply to architecture in its traditional meaning. Nevertheless, a two-fold link between the new ontologies and architecture can be posed. On the one hand, the former offer a new language to describe the variety of traditional architecture and accept that all of directions, styles and buildings are ontologically coordinate. On the other hand, the new ontologies enable some new architectural practices (computer architecture, architecture of virtual space and speculative architecture) which do not substitute for traditional architecture, but accompany it.
Keywords: new ontologies, flat ontologies, architecture, computer architecture, architecture of virtual space, speculative architecture
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.
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
Existing approaches suggest that IT strategy should be a reflection of business strategy. However, actually organisations do not often follow business strategy even if it is formally declared. In these conditions, IT strategy can be viewed not as a plan, but as an organisational shared view on the role of information systems. This approach generally reflects only a top-down perspective of IT strategy. So, it can be supplemented by a strategic behaviour pattern (i.e., more or less standard response to a changes that is formed as result of previous experience) to implement bottom-up approach. Two components that can help to establish effective reaction regarding new initiatives in IT are proposed here: model of IT-related decision making, and efficiency measurement metric to estimate maturity of business processes and appropriate IT. Usage of proposed tools is demonstrated in practical cases.
Let G be a semisimple algebraic group whose decomposition into the product of simple components does not contain simple groups of type A, and P⊆G be a parabolic subgroup. Extending the results of Popov , we enumerate all triples (G, P, n) such that (a) there exists an open G-orbit on the multiple flag variety G/P × G/P × . . . × G/P (n factors), (b) the number of G-orbits on the multiple flag variety is finite.
I give the explicit formula for the (set-theoretical) system of Resultants of m+1 homogeneous polynomials in n+1 variables