Особенности моделирования распределенных систем
Accuracy of aircraft district location determination in changing daily, weather climatic conditions is a crucial factor which civil and military aviation usage efficiency and sometimes appropriateness is dependent on. Despite permanent inertial and satellite navigating systems, which all modern aircrafts are equipped, by performance quality improvement still required accuracy of aircraft district location determination is not reached. This fact still forces to use three-dimensional navigating systems which are installed aboard of specialized aircrafts for civil applications and which are essential for military aircraft of 5th generation. Latest three-dimensional navigating systems investigations show that their performance accuracy improvement requires joint use of methods and algorithms of estimation, identification and test of hypothesis during stereoscopic pairs of large ground images real-time processing. Therefore success of three-dimensional navigating systems practical usage is mainly defined by performance, computing stability and fault tolerance of onboard computing systems which are dominantly based on RISC-processors and FPGA-video-processors (Field Programmable Gate Array). The received empirical estimations of required performance, computing stability and fault tolerance show: 1. The elementary searchless district location determination based on one stereopair processing requires ~(0,12-0,6) *108 operations of multiplication and addition. Such a task is able to be processed in 1 second by RISC-processor with performance not below some Gflops, taking into account computing organization system time costs. 2. If micro program management intermediate level is presented in FPGA-technologies based on VHDL than algorithmically-focused MIMD-bit-stream three-dimensional navigating systems videoprocessor is potentially implementable on the basis of one VLSI FPGA Xilinx Virtex 6. Such a processor is possible to achieve performance of V=FT*Lp/n=500*106*192/64≈1,5*109 operations per second in double-format. This performance rate is enough for target size stereopairs processing rate of 25÷125 images per second so given performance exceeds algorithmic costs for one required format stereopair processing exactly this amount of times. Here: FT - bit-matrix clock rate, Lp - one cycle operations quantity, n - arithmetics capacity. It is fundamental that there are no system time costs on real-time computing resources management in MIMD-bit-stream computing technologies so that computing expenses become comparable with algorithmic in such videoprocessors. 3. Despite the fact that required by three-dimensional navigating systems algorithms computing performance and accuracy are achievable both in RISC-architecture and specialized FPGA-based architectures, 5th generation aircrafts such as F-35 should stabilize flight parameters, used for high-precision own location determination, which is realizable only at its separate stages. At the same time it should be kept in mind that computing paralleling index increase more than 4 times may lead to loss of onboard three-dimensional navigating system computer based on RISC-platforms computing stability. 4. RISC-architecture fault tolerance more than 10 times less than specialized FPGA-bit-stream architectures one. It is the most essential for spaceships which lifetime should exceed VLSI components nonfailure operating time more than 10 times. Such fault tolerance indicators qualitative divergence is caused by: - indifferent failures presence in bit-stream architectures which quantity exceeds ratio of failures parried by RISC-architecture processors majority reservation schemes; - possibility of ~112 times bit-stream microprograms field re-allocation on a bit matrix tolerantly operating failure map.
It turns out, however, that in spite of one basic difference there runs between these two systems a deep and striking parallelism. This parallelism is so close indeed that it makes possible the construction of a vocabulary which would transform characteristic propositions of Wittgenstein's ontology into Aristotelian ones, and conversely. To show in some detail the workings of that transformation will be the subject of this paper.
We describe a novel method for the analysis of research activities of an organization by mapping that to a taxonomy tree of the field. The method constructs fuzzy membership profiles of the organizationmembers or teams in terms of the taxonomy’s leaves (research topics), and then it generalizes them in two steps. These steps are: (i) fuzzy clustering research topics according to their thematic similarities in the department, ignoring the topology of the taxonomy, and (ii) optimally lifting clusters mapped to the taxonomy tree to higher ranked categories by ignoring “small” discrepancies. We illustrate the method by applying it to data collected by using an in-house e-survey tool from a university department and from a university research center. The method can be considered for knowledge generalization over any taxonomy tree.
Збірка наукових праць
In the paper integrated information systems for corporate planning and budgeting are considered. Four groups of practical tasks exceeding the bounds of typical functionality of special-purpose planning and budgeting information systems are allocated. Several classes of information systems (simulation, statistical analysis, financial analysis and modeling, group decision making, business intelligence), which may provide the completeness of corporate planning and budgeting are denoted as solutions complementary to special-purpose planning and budgeting systems.
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.