Верхняя граница вероятности ошибки в системах связи, использующих однопользовательский прием на основе порядковых статистик
The model of a channel that describes the transmission of information in communication systems with a single-user receiver based on order statistics is considered. The transmission of information through such a channel using a linear block code is studied. The aim of this paper is to find an upper bound on error probability for the case in which exhaustive search and a given decoding criterion are used.
In what follows the problem of finding upper bounds on denial probability and probability of erroneous decoding in a coded Dynamic Hopset Allocation Frequency Hopping system with noncoherent threshold reception is considered.
We consider a fractional 0-1 programming problem arising in manufacturing. The problem consists in clustering of machines together with parts processed on these machines into manufacturing cells so that intra-cell processing of parts is maximized and inter-cell movement is minimized. This problem is called Cell Formation Problem (CFP) and it is an NP-hard optimization problem with Boolean variables and constraints and with a fractional objective function. Because of its high computational complexity there are a lot of heuristics developed for it. In this paper we suggest a branch and bound algorithm which provides exact solutions for the CFP with a variable number of cells and grouping efficacy objective function. This algorithm finds optimal solutions for 21 of the 35 popular benchmark instances from literature and for the remaining 14 instances it finds good solutions close to the best known.
The paper considers certain probability-theoretic models of packet mode-transferred information distortions. Attention is drawn mainly to distortions, including possible interferences influencing multiple transfer cycles. Distortions are modeled by a consequential impacts that are defined by dependent random variables. K-dimensioned values of CRC, respectively allow representation as a sum of k-dimensioned independent random variables.
In some cases it is possible to bring them to a sum of independent terms in a k-dimensioned vector space over a two-element field and, afterwards, apply to them existing limit theorems dealing with convergence to uniform distributions.
The paper discusses prospects for impacts stretching to m cycles of acquiring convergence conditions for CRC distribution as a sum of m-dependent terms or ones not interconnected to a non-homogeneous Markov chain.
This paperwork is dedicated to research of k-length CRC value distribution for data interval with volume n. It is shown in research  that CRC value could be represented as a sum of special-way formed random vectors over k-dimension vector space GFk(2) over a two-element 0,1-field (GF(2)).If the message or errors are modeled using independent random 0,1 values sequences, CRC could be regarded as a sum of independent random vector components.
The paperwork examines CRC value distribution’s behavior under conditions of big n’s and fixed values of k. By means of character theory application we find the conditions of asymptotic unification of CRC distribution.
Asymptotic results could be applied for error estimation for various telecommunication protocols (e.g. USB, X.25, HDLC, Bluetooth, Ethernet and others).
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
The geographic information system (GIS) is based on the first and only Russian Imperial Census of 1897 and the First All-Union Census of the Soviet Union of 1926. The GIS features vector data (shapefiles) of allprovinces of the two states. For the 1897 census, there is information about linguistic, religious, and social estate groups. The part based on the 1926 census features nationality. Both shapefiles include information on gender, rural and urban population. The GIS allows for producing any necessary maps for individual studies of the period which require the administrative boundaries and demographic information.
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.