SCIENCE & EDUCATION

 The article describes an experiment aimed at defining the dependence of muscle vibration parameters (frequency and damping decrement) on a sportsman’s physical fatigue. Experimental results and summary allow to combine training load and rest in order to achieve more efficient training process.

The article covers treadmill bench tests of tire acoustics experimental prediction. The roller has three physical models of road surface with different levels of roughness. The authors give reference surface parameters and the roller reference surface. They also give recommendations on the choice of roller coating parameters and consider the structure of tire noise evaluation in test-bench conditions. The article tells about a method of reduction of control surface measurement results to a standard (virtual) surface. They describe computational procedures for determining the approximating dependence parameters for predicting tire noise level.

The article considers nonlinear filtering methods based on approximation of estimation probability density by means of a set of weighed points in phase space. The given methods are applied to one problem of a target tracking with nonlinear radar sensor. The article provides results of modeling the algorithms in comparison with widely used classical and extended Kalman filtering algorithms.

 This article describes an innovative mental-structured educational technology focused on training technical specialists, built on the basis of human memory and thinking laws.  This training provides technical specialists’ high competitiveness in rapidly changing market requirements for educational services and intellectual work. There are five basic principles of mental-structured educational technology. 

 This paper considers the causes of metastability during the interaction of devices controlled with asynchronous clock signals. The article suggests different ways of eliminating metastability and proposes using a FIFO buffer with asynchronous FIFO pointer comparison.

The article covers potential ratios of abrasive powder, pores and couplant in the composite material of an abrasive tool. Analytical relations for calculating maximum fillings by a heterogeneous phase were obtained. The optimal composite structure is the structure which has a maximum proportion of the abrasive material in the tool. It is shown that for abrasive grain the size of which is less than 30 microns an optimal size of pores is 0,5 mm. Maximum volume filling of abrasive composites at continuous distribution of particles of heterogeneous phases according to sizes was calculated. It is shown that the maximum content of abrasive in the tool volume accounts for 15-16%. The authors describe an empirically defined criterion of tool formability characterizing the binder’s ability to keep abrasive grains.

The rising demand for air transportation, introduction of a new generation of aircraft technology and modernization of the infrastructure sectors are making new demands for qualitative reliability and flight staff of commercial aviation maintenance staff. Airlines are interested in retaining their employees and improving motivation programs. Taking into account the fact that the target of business is profit (for all motivation programs require expenses), the problem of cost optimization is particularly acute. Different methods of motivation require different investments and have a different impact on staff. It’s obvious that reasonable combination of motivation methods will lead to the target results or get closer to them. The article covers questions of using a regression analysis for assessing employees’ reaction to the change of the motivation system and for forecasting results of organization department work. The authors provide an example of calculations for an airline department.

This paper covers a method of program module allocation into computer subsystems (CS) for the cases when the program module execution time is known. This allows you to pre-make plans to address the problem of parallel computing system, which is an important factor in developing solutions for a computer system parallel task. The authors propose creating a plan for solving the problem of information and information-logical unified-memory flowgraphs. The plan is presented in the form of parallel task flowgraph threads which a serial arrangement in computer system components. Pre-planning allocation routines for computation modules reduces the problem solution time and increases the efficiency of computing resources.

 Dynamic behavior of essentially new log processing equipment – cranked multirip bench with circular translational movement of saw blades was researched. Mathematical models for core element of the bench (saw module) and for system as a whole were created. Motion stability of saw module is analyzed using Floquet-Lyapunov’s method and qualitative research techniques are used for whole system’s motion analysis. The author studied design factors influence on the core element behavior and system as a whole. The author discovered that though the core element (saw module) has nonlinear behavior and certain unstable modes, the system as a whole consisting of six core elements displays mostly linear behavior and is independent of neither the rotation angle nor the angular velocity of drive shaft. The results obtained in this work are included in the author’s methodology for efficient design of essentially new log processing equipment.

 We present two parallel algorithms for relational connection on graphics processing units (GPU). The article considers the cases when the connection result is located in GPU memory and is returned by portions. Performance tests show five-fold advantage of GPU over CPU for non-indexed nested loops and 1.4-fold advantage for indexed nested loops.

The article considers reasons of failures of the block and tackle elevator system and factors which influence its longevity. The authors review the procedure of parameter determination of the block and tackle elevator system by analyzing the results of multivariant calculations. The authors give recommendations regarding processing of the data obtained during the calculation. They justify the choice of the contact pressure value as the standard of longevity of the block and tackle elevator system.  The authors examine the contact pressure calculation in the stream which differs from the traditional one by separate examination of the diameters of the rope-guiding pulley and rope, and also of the profile of the stream of the rope-guiding pulley.

 The article shows the importance of a single complex efficiency criterion for innovative projects, which is centrally approved, and will allow an a priori evaluation of projects in indeterminacy typical to early stages of development. The criterion of efficiency not overloaded with a considerable quantity of parameters reflects target directivity of the task (operation) and in the conditions of restrictions and superimposed uncertainties allows solving so-called "direct" research problems of operations which help to create formation of programs from engineering positions.

This article considers laser method of measurement of thickness and refraction index of a nanofilm on substrate. It is shown that the method based on determination of the first-order derivative of reflection coefficient allows to measure (with very few measurement errors) thickness and refraction index of a film at a measurement error of determination of reflection coefficient and first-order derivative of reflection coefficient by ~ 0,3 % in a wide range of refraction index (~ 3…7 and more) and thickness (~ 10…100 nm and more).  

Purpose - to present the results of research of complex spatial motion of submersible vehicles in graphic form for quick evaluation and possible adjustment of the simulation model. The method of study -  computer animated 3D simulation in virtual reality. Scope of the results - a simulation study with different modes of spatial motions of underwater vehicles. The resulting model is useful for rapid prototyping and application in training, presentations and research purposes. Creating such a complex model is not difficult for non-programmers who have almost no knowledge and skills in programming in any programming languages. The disadvantage of this way of development of the model – it requires a lot of computer resources. To reduce the resources it’s necessary to optimize the work of the system by using RealTimeWorkshop MATLAB.

The article considers problems of choosing a structure of multiprocessing computer systems. Using the spectral theory of graphs, methods of choosing multiprocessing computer systems structures are described. The authors study the influence of structural performances of graph computer system on complexity, productivity and fault tolerance of computer system.

The article presents WR-grammar which is the basis for creation of a compiler which is adjusted to processing of programs written in various languages or their dialects and for various types of processors. Compilers of this type can be applied successfully in data processing computing systems. Necessity of creating compilers is due to existence of a lot of programming languages and their dialects focused on various types of processors, which causes certain difficulties at task solving on computing systems – even a very skilled programmer has difficulty solving them. Using a parametrical compiler, computer system administrator or operating system only has to do the following: to adjust the compiler to the required language or the language version and type of the processor by means of setting corresponding parameter values from a predefined list.

 The article presents the data obtained after comparing compressed powdered metal parts cutting with their analogs made of identical compact materials. Comparison of workability of identical materials both in powder and compact design is made in identical conditions. The authors obtained similar dependence of wear of different tools, which allows using extensive data at design of porous molded parts process technologies which are known for their compact analogs. There is certain decreased accuracy of powder materials processing in comparison with their compact analogs. The data of tool wear are obtained by two different methods.

 The article covers theoretical basis of spectral analysis in the Hartley basis, including the original scalar method of fast Hartley transformation algorithm synthesis using static and sliding time intervals. Theoretical results are illustrated by concrete examples. 

 The article sets out the necessity of establishing a global multifunctional space system of remote Earth sensing focused on integrated sensing of terrestrial objects, including the sensing with the expansion of the spectrozonal range. Currently, at restricted financing, creation of such a system is impossible without carrying out a feasibility study and a performance analysis of its usage, which is an important state task. The basic principles of a feasibility study is the approved methodical device using a cost-based mechanism in space systems creation.

 The paper gives an analysis of the problem of developing vehicles for northern climate. The article gives an overview and analysis of selected publications, prospectuses of companies, websites of companies - manufacturers of vehicles with low-pressure tires. The article describes a series of standard size vehicles with low-pressure and superlow-pressure tires both of domestic and foreign production (U.S., Canada, Belarus). The paper provides examples and describes basic models of vehicles of standard size series. The authors draw conclusions on the issue of developing vehicles with low-pressure and superlow pressute tires in the northern climate.