Open Repository of Keldysh Institute of Applied Mathematics of RAS
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Mission Design for Venusian Projects of the 2021-2028 Years Epoch. Launch Windows
No full textAbstract:
Secure methods of the cost-effective flights to Venus and the passage of its gravity sphere are necessary to increase the amount of scientific and service equipment on board spacecraft and effectively exploration of the solar system. The results of the modern methods of ballistics design using for interplanetary flights to Venus in 2021- 2028 epoch are given with the purpose of accomplishing a gravitational maneuver around it, or entering the Venusian satellite orbit for the landing on its surface. In the first work of the cycle the main attention is paid to the construction of the launch windows, the second work devoted to the calculation of the reachability areas of the descent vehicle on the surface of Venus.Note:
Research direction:Mathematical modelling in actual problems of science and technic
Short single tests for logic networks under arbitrary stuck-at faults at outputs of gates
No full textAbstract:
We consider a problem of synthesis of irredundant logic networks implementing Boolean functions on n variables and allowing short single tests regarding arbitrary stuck-at faults at outputs of gates. It is proved that one can implement any non-constant Boolean function by a network in the basis “conjunction, negation, sum of three variables modulo two”, allowing a single fault detection test with a length not exceeding 2, and by a network in the basis consisting of one certain Boolean function on six variables, allowing a single diagnostic test with a length not exceeding 3.Note:
Research direction:Mathematical modelling in actual problems of science and technic
The algorithms of navigation satellites signals reception on Board the spacecraft using a correlator
No full textAbstract:
The work conducted in the framework of the create the onboard Autonomous navigation system of near-earth spacecraft. The paper presents the methods and algorithms to operate the device search and tracking of radio navigation signals with high dynamics of the movement. The paper presents the results of computational experiments.Note:
Research direction:Theoretical and applied problems of mechanic
The Algorithm for Modeling Radiation Thermomechanical Effects in Cattaneo Approximation
No full textAbstract:
The effect of ionizing radiation on a micro-electronics product is considered. The propagation of heat and mechanical stresses is presented as a single process for the transport of crystal lattice phonons, conduction electrons, and holes of the valence band. A related model based on the equations of thermoelasticity is formulated. The transport of heat is described by the law of conservation of energy and the Cattaneo equation, a consequence of the kinetic equation for phonons. Lattice vibrations are considered in the approximation of the linear theory of elasticity. Difference schemes for solving model equations are developed.Note:
Research direction:Mathematical modelling in actual problems of science and technic
Expansion of ODE solutions into transseries
No full textAbstract:
We consider a polynomial ODE of the order n in a neighbourhood of zero or of infinity of the independent variable. A method of calculation of its solutions in the form of power series and an exponential addition, which contains one more power series, was described. The exponential addition has an arbitrary constant, exists in some set E1of sectors of the complex plane and can be found from a solution to an ODE of the order n - 1. An hierarchic sequence of such exponential additions is possible, that each of these exponential additions is defined from an ODE of a lower order n - i and exists in its own set Ei. Here we must check the non-emptiness of intersection of the sets E1∩ E2∩ ... ∩ Ei. Each exponential addition continues into its own exponential expansion, containing countable set of power series. As a result we obtain an expansion of a solution into a transseries, containing countable set of power series, all of which are summable. The transseries describes families of solutions to the initial ODE in some set of sectors of the complex plane.Note:
Research direction:Mathematical modelling in actual problems of science and technic
DNA devices based on DNA. Nanobioelectronics
No full textAbstract:
It is shown that DNA molecule can be used for construction of different electronic devices. The results of investigation of DNA conducting properties are presented. The method of DNA based nanowires is considered. It is shown that the conducting properties of DNA can be used for making electronic nanobiochips, which have advantages in comparison with optical one due to their miniaturization execution speed, absence of marking and exactness. It is also demonstrated the possibility of memory and logic devices made from DNA.Note:
Research direction:Mathematical modelling in actual problems of science and technic
Proceedings of the conference as a serial publishing
No full textAbstract:
The questions related to the specificity of conference proceedings as a serial scientific publishing are considered. Recommendations are given to help conference organizers to improve the quality of conference online materials, to remove some problems in obtaining ISSN, ISBN numbers and DOI, to index the publication in the RSCI.Note:
Research direction:Programming, parallel computing, multimedi
Model for the calculation and theoretical justification for associated petroleum gas utilization technology with use of flare gases
No full textAbstract:
The article presents model and calculations to justify a new technology for utilization of associated petroleum gas for use in medium and remote fields, fields with undeveloped infrastructure, as well as offshore oil and gas fields using flare gases. The proposed technology allows to reduce the capital costs for the development and exploitation of the field, while ensuring high efficiency, rapid integration into the existing flow scheme without introducing additional significant changes into it and with minimal harmful impact on the environment. The article also describes the limitations of existing technologies for gas utilization, such as large size and weight of used units, which is unacceptable in offshore platform, which has limitations on the permissible weight and dimensions of the equipment being placed.Note:
Research direction:Mathematical modelling in actual problems of science and technic
Comparative analysis of the equilibrium configurations and radiation transport in the Galatea traps 'Trimix' and 'Trimix-3M'
No full textAbstract:
The equilibrium magnetoplasma configurations obtained for the Galatea traps based on the Grad-Shafranov equation are presented. The spectral field of radiation and its integral characteristics in the magnetic traps 'Trimix' and 'Trimix-3M' are investigated.Note:
Research direction:Mathematical modelling in actual problems of science and technic
The application of the method of 'Semblance' in passive seismic for monitoring oil and gas fields
No full textAbstract:
The paper deals with the identification and localization of underground sources of acoustic emission (AE) on the basis of passive seismic methods for monitoring the development and operation of oil and gas fields. There are considered some peculiarities of application of seismic emission tomography based on coherent assessment of the “Semblance”. The algorithm of localization of AE sources, including the tracing of acoustic rays (“bending”), is described. There is proposed optimization algorithm for the tracing and of the outlined methods to improve the accuracy of the localization. The results of the test of model calculations demonstrate the effect of the quality of the velocity model of the medium and the surface seismic antenna aperture on the localization accuracy. In particular, the results of calculations of the problem of localization of a large number of remote emission sources are presented and discussed. The conclusion is made about the prospects of the considered method for solving the problems of real-time monitoring of deposits, in particular, off-shores.Note:
Research direction:Mathematical modelling in actual problems of science and technic