Key Engineering Materials Vol. 685

Abstract: Design of the conceptual information domain model is a significant and complicated stage in database development that influences its quality and can be considered as a skill. The suggested approach is based on analysis of attribute domains and relationships between them and uses the relational data model to determine the availability and the type of relationships between model entities.

Abstract: The article discusses the development of a queuing system with the use of various queuing disciplines. The authors have developed a model of the queuing system and conducted the experiments on system overload, which helped to distinguish its weaknesses and improve it using dynamic priorities. The priority is increased on a one-off basis for an entity with low priority under specified conditions. Consequent testing of the system has confirmed its robustness.

Abstract: The paper is devoted to basic principles to develop software queueing networks simulations. A mathematical model and general scheme of the queueing network are presented in the paper. Main network components and behavior parameters are described. The application can simulate the networks of rather complex configuration. Software under construction uses a discrete-event approach for the simulation process. Basic algorithm of the simulation is also presented.

Abstract: The paper is devoted to the simulation of queueing networks on high performance computer clusters. The objective is to develop a mathematical model of queueing network and simulation approach to the modelling of the general network functionality, as well as to provide a software implementation on a high-performance computer cluster. The simulation is based on a discrete-event approach, object oriented programming, and MPI technology. The model of the queueing networks simulation system was developed as an application that allows a user to simulate networks of rather free configuration. The experiments on a high performance computer cluster emphasize the high efficiency of parallel computing.

Abstract: The present paper proposes graphical interface for determination of optimal parameters of cutting modes for turning process. The proposed graphical interface is different from other well-known ones. The impact of different factors on the cutting process in order to determine optimal parameters in accordance with the given effectiveness criteria are analyzed. The visual graphical form of information presentation, database, mathematical model of optimization, algorithms and computer programs have been developed.

Abstract: Distributed systems containing hundreds or thousands of objects, are generally constructed in the form of hierarchical structures. In these structures, the lower level objects in the subset are combined for connecting to centers. Existing algorithms are not able to successfully meet the challenges of structuring on the sets of such dimension. Therefore, new algorithms suitable for solving the problems of structuring on the sets containing thousands of objects are necessary. The authors developed an algorithm to form objects clusters for high cardinality sets, with up to a thousand or more objects located in a given area. The algorithm is developed with the help of graph theory, design and analysis of algorithms efficiency, compact partitions theory, compact sets of objects and their clusters. Geographical location of a set of objects of a distributed system is considered as a topological graph. To improve the efficiency of the algorithm of forming compact sets and clusters allocation the concept of the zone of active search for nearby vertices is introduced. That enables the possibility to replace a matrix of distances between the vertices to list of vertices incidents formed on the basis of active search zone. An algorithm for the approximate solution of clusters allocation of topological graph objects represented by a list of vertices incidents is developed. The algorithm recurrently increases the cardinality of compact sets for each object and analyzes acquired clusters. Algorithm description is accompanied by an example.

Abstract: The paper presents a system for visualizing and analyzing multivariate data for distinguishing the major aspects of aggregating data without applying the quantitative analysis method and instant diagnosis of a pregnant woman’s health condition. The paper justifies the necessity of processing multivariate data with the use of the “NovoSpark Visualizer” specialized software suite. An illustrating example as well as the evaluation of pregnant women’s health on the basis of real data is presented.

Abstract: The distinctive paper is devoted to application of wavelet-based discrete-continual finite element method (WDCFEM), to analysis of plates with piecewise constant physical and geometrical parameters in so-called “basic” direction. Initial continual and discrete-continual formulations of the problem are presented. Due to special algorithms of averaging using wavelet basis within multigrid approach, reduction of the problem is provided. Resultant multipoint boundary problem for system of ordinary differential equations is given.

Abstract: This article is devoted to the usage of the method of representing vectors. The paper contains the basic principles of the method. The article includes the algorithm for generation of the dynamic system control signal according to the method of representing vectors. According to the method, the desired output signal is transformed to a vector and all the intermediate operations are carried out in a digital form; after that the control signal is regenerated according to the conversion formula.