On strategy-proof direct mechanism of active expertise over strictly convex compact set

We investigate the problem of strategy-proofness in the active expertise process where the decision making are based on the messages of experts who can distort the information for their benefit. In our model the expertise result is the arithmetic mean of expert messages and the opinion space is the multi-dimensional strictly convex compact set. We construct the corresponding direct expertise mechanism. We also prove that there is no strategy-proof direct expertise mechanism for this case. The problem of finding mechanism with minimum manipulation equivalent to the arithmetic mean expertise mechanism is formulated.     

Improvement of basic requirements for the system and devices of traction dc power supply

Abstract—“The Technical Maintenance Regulations of Russian Federation Railways” and “The Arrangement Regulations of the Russian Federation Railways Traction Power Supply System (TsE-462)” set out clear requirements to ensure minimum voltage in the aerial contact wire for freight and high-speed passenger train movement. These requirements are confirmed by the Norms of the European Electrotechnical Standard EN 50163 (1995). However, the voltage norms at traction substations (TsE-462) are in contradiction to the maximum continuous voltage in the aerial contact wire demanded by Railway Research Institute (VNIIZhT) and accepted by EN 50163 Standard. This paper proposes using continuous voltage at traction substations in the normal operating mode in the range of from 3600 (the minimum value) to 3700 V. The maximum voltage (3700 V) was obtained as a result of electrical calculation of the traction power supply system at the track sections with hard mountainous track profile while running trains with an increased weight of 6300–9000 t or two combined trains with a combined weight of 12000 t with powerful electric locomotives of 2ES6, 2ES10, and 3ES10 series. This voltage value was confirmed by long-term operation on a Tyumen–Yekaterinburg–Perm–Balezino track section of 923-km length with voltage stabilization at the level of 3650 V at the traction substations. The voltage levels at the traction substation buses are provided by a contactless automatic control system (CACS) with ±0.6% inaccuracy. The maximum voltage in the traction substation buses is acceptable and equal to maximum aerial contact wire voltage (4000 V) under the recuperation mode.     

Information Technologies for Development Management Systems

We propose an interconnected complex of information technologies based on mathematical models. The proposed complex complements the technology of constructing development management systems (DMS), significantly increasing its effectiveness. This complex includes an integrated assessment system for the status of the development program, methods for constructing the program that take into account multipurpose and interdependent projects and a risk management, operational management, and scheduling model.     

Influence of La Doping on the Transport Properties of Bi1 –xLaxCuSeO Oxyselenides

Semiconductors - The transport properties of p-type oxyselenides with the chemical composition Bi1 –xLaxCuSeO (x = 0.02, 0.04, 0.06) are investigated. An analysis of the temperature...     

A conceptual model of power supply for the integrated grid of high-speed railway transport in Russia

The strategy of railway-transport development in Russia until 2030 and beyond involves the application of new technologies ensuring the competitiveness of Russian railways, which act as one of the key growth factors of the economy and its system-forming sector in the transportation industry of Russia. The article discusses the main factors and breakthrough technologies on the basis of which an integrated grid of high-speed railway connection is created. Paramount importance is given to increasing the speed of passenger and freight trains, combining high-speed railway lines into a single grid to provide an agglomeration effect, mobility, energy efficiency, and environmental safety. One of the priorities is the factor of reliable and safe power supply of competitive railway connections, for which a conceptual model of railway power supply is developed.     

Absorption and circular-dichroism spectra of LaBGeO5 crystal doped with Pr and Ho ions

Absorption and circular-dichroism spectra of LaBGeO₅ crystal doped with Pr³⁺ and Ho³⁺ ions were investigated at 8 K in the range 300-900 nm. Electronic transitions of these ions, which substitute La³⁺ ions in positions with a local symmetry C₁ are observed in the spectra. All transitions are active in both absorption and circular-dichroism spectra. Values of the dipole strengths D_om, rotation strengths R_om and anisotropy factors g are calculated for some well-separated bands.     

Multivariant Active Systems

The concept of multivariant active systems was presented. Basic multivariant structures, facilities, and systems were described. Consideration was given to the heuristic and, in part, strict problems of analysis, design, and realization of the variant-uniting organizational mechanisms integrated with the functional and auxiliary subsystems of the multivariant active systems including appropriate structural, procedural, and algorithmic developments. Particular multivariant active systems for education, industries, and industrial research were described.     

Deposition of Amorphous Hardening Coatings by Electrospark Treatment in a Mixture of Crystalline Granules

This article is devoted to the formation of amorphous coatings on the steel 35 surface by electrospark treatment in a mixture of crystalline granules. It is revealed by the energy dispersive X-ray spectroscopy (EDS) that formed coatings contain W, Mo, Co, and Ni in various ratios. The weight of granules of various compositions decreases by 11–16 wt % for 6-h treatment due to electric erosion. The mass transfer coefficient varies in a range from 33 to 54%. X-ray structural analysis showed the prevalence of an amorphous phase (81–99%) in the structure of deposited layers. Annealing of coatings at a temperature above 1150°C leads to the crystallization of the amorphous phase into boron carbide of the M23(C, B)6 type, as well as into α-Fe. The coatings have an increased hardness of 10–15 GPa, while their wear resistance in the dry sliding wear mode under loads of 10 and 50 N is higher than for steel 35 by a factor of 3.3 and 1.6. The coating friction coefficient is lower than for steel 35 by 13–30% and was 0.27–0.31. The wear resistance of coatings in a dry abrasive wear mode is higher by a factor of 3–5 when compared with uncoated steel 35. The best characteristics are inherent without nickel and worst are inherent without cobalt. Thus, it is established that tungsten and cobalt increase the wear resistance of iron-based amorphous alloys, while nickel and molybdenum tend to worsen their tribotechnical behavior.     

Modern asynchronous electrical drive for a numerically controlled machine

We present the results of developing a digital asynchronous electric drive designed for machines with digital numerical control (NC). We propose a set of tests for qualitative parameters of an electric drive with feedforward connections with respect to the derivatives of the reference signal. We present test results for an electric drive prototype that conforms to modern requirements for electric drives in NC systems.