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Oleg Kupervasser

Publications and source records attributed to Oleg Kupervasser.

At least 19 recordsLinked to original sources
arXiv2026

Integro-differential equations in angular stabilization of drone motion by distributed feedback control

In this paper, we propose angular stabilization of drone motion using distributed feedback control in the form of an integral operator. It should be stressed that the memory of this integral operator could be unbounded. It is intuitively clear that large length of the observation time open new possibilities to construct better control based on previous states of the control object. Unbounded memory in control requires the creation of a certain approach different from standard ones to the study of integro-differential equations. One of the goals of this article is to propose a certain universal approach that allows us to study the stability of integro-differential equations in the case of unbounded memory in the integral operator specifying the feedback control in stabilization. The approach we propose allows us to reduce the study of integro-differential equations to the analysis of systems of ordinary differential equations. In general, such systems can consist of an infinite number of equations. In relation to the so-called linear approximation in the problem of angle stabilization manages to limit itself to relatively simple exponential kernels in the integral control and arrive at a system with a finite number of equations. The examples explain that more complex kernels, for example, linear combinations of the exponential kernels, can enhance the stabilization capabilities. We obtain new unexpectable results on the exponential stability of integro-differential equations. Then we apply them to stabilization of drone flight.

cs.AI↗
arXiv2019

Visual navigation for airborne control of ground robots from tethered platform: creation of the first prototype

We propose control systems for the coordination of the ground robots. We develop robot efficient coordination using the devices located on towers or a tethered aerial apparatus tracing the robots on controlled area and supervising their environment including natural and artificial markings. The simple prototype of such a system was created in the Laboratory of Applied Mathematics of Ariel University (under the supervision of Prof. Domoshnitsky Alexander) in collaboration with company TRANSIST VIDEO LLC (Skolkovo, Moscow). We plan to create much more complicated prototype using Kamin grant (Israel)

cs.RO↗
arXiv2018

Robust positioning of drones for land use monitoring in strong terrain relief using vision-based navigation

For land use monitoring, the main problems are robust positioning in urban canyons and strong terrain reliefs with the use of GPS system only. Indeed, satellite signal reflection and shielding in urban canyons and strong terrain relief results in problems with correct positioning. Using GNSS-RTK does not solve the problem completely because in some complex situations the whole satellite's system works incorrectly. We transform the weakness (urban canyons and strong terrain relief) to an advantage. It is a vision-based navigation using a map of the terrain relief. We investigate and demonstrate the effectiveness of this technology in Chinese region Xiaoshan. The accuracy of the vision-based navigation system corresponds to the expected for these conditions. . It was concluded that the maximum position error based on vision-based navigation is 20 m and the maximum angle Euler error based on vision-based navigation is 0.83 degree. In case of camera movement, the maximum position error based on vision-based navigation is 30m and the maximum Euler angle error based on vision-based navigation is 2.2 degrees.

cs.CV↗
arXiv2014

Laplacian Growth II: Saffman - Taylor Problem Without Surface Tension in Filtration Combustion: Formation of One Finger with Half of the Channel Width

Filtration combustion is described by Laplacian growth without surface tension. These equations have elegant analytical solutions that replace the complex integro-differential motion equations by simple differential equations of pole motion in a complex plane. The main problem with such a solution is the existence of finite time singularities. To prevent such singularities, nonzero surface tension is usually used.However, nonzero surface tension does not exist in filtration combustion, and this destroys the analytical solutions. However, a more elegant approach exists for solving the problem. First, we can introduce a small amount of pole noise to the system. Second, for regularisation of the problem, we throw out all new poles that can produce a finite time singularity. It can be strictly proved that the asymptotic solution for such a system is a single finger. Moreover, the qualitative consideration demonstrates that a finger with 1/2 of the channel width is statistically stable. Therefore, all properties of such a solution are exactly the same as those of the solution with nonzero surface tension under numerical noise. The solution of the ST problem without surface tension is similar to the solution for the equation of cellular flames in the case of the combustion of gas mixtures.

nlin.CD↗
arXiv2014

Laplacian Growth I: Finger Competition and Formation of a Single Saffman-Taylor Finger without Surface Tension: An Exact Result

We study the exact non-singular zero-surface tension solutions of the Saffman-Taylor problem for all times. We show that all moving logarithmic singularities a_k(t) in the complex plane ω= e^{iϕ}, where ϕis the stream function, are repelled from the origin, attracted to the unit circle and eventually coalesce. This pole evolution describes essentially all the dynamical features of viscous fingering in the Hele-Shaw cell observed by Saffman and Taylor [Proc. R. Soc. A 245, 312 (1958)], namely tip-splitting, multi-finger competition, inverse cascade, and subsequent formation of a single Saffman-Taylor finger.

patt-sol↗
arXiv2013

The basic paradoxes of statistical classical physics and the quantum mechanics

Statistical classical mechanics and quantum mechanics are developed and well-known theories that represent a basis for modern physics. The two described theories are well known and have been well studied. As these theories contain numerous paradoxes, many scientists doubt their internal consistencies. However, these paradoxes can be resolved within the framework of the existing physics without the introduction of new laws. To clarify the paper for the inexperienced reader, we include certain necessary basic concepts of statistical physics and quantum mechanics in this paper without the use of formulas. Exact formulas and explanations are included in the Appendices. The text is supplemented by illustrations to enhance the understanding of the paper. The paradoxes underlying thermodynamics and quantum mechanics are also discussed. The approaches to the solutions of these paradoxes are suggested. The first approach is dependent on the influence of the external observer (environment), which disrupts the correlations in the system. The second approach is based on the limits of the self-knowledge of the system for the case in which both the external observer and the environment are included in the considered system. The concepts of observable dynamics, ideal dynamics, and unpredictable dynamics are introduced. The phenomenon of complex (living) systems is contemplated from the point of view of these dynamics.

physics.gen-ph↗
arXiv2013

"New Cybernetics and the Application of its Principles in Physics" and "Comment on "Quantum Solution to the Arrow-of-Time Dilemma" of L. Maccone arXiv:0802.0438"

The first paper: We describe principles of new cybernetics and use these principles for resolution of basic physical paradoxes. It demonstrates universality of the principles of new cybernetics. The second paper: recent letter by Maccone presents a solution based on the existing laws of quantum mechanics to the arrow-of-time dilemma. He argues that all phenomena in which the entropy decreases must not leave any information (in the observer's memory) of their having occurred because the observer is a part of the whole system. Maccone concludes that quantum mechanics is necessary to his argument, which he believes does not otherwise work in classical mechanics. This Comment consists of four parts. We discuss the basic problems in the first part. This Comment and the previously published Comment by Jennings and Rudolph describes flaws in Maccone's arguments. However, the main argument (erasure of the observer's memory), which was previously formulated in our work and was repeated by Maccone, is correct under the conditions described in this Comment. Moreover, this argument can be used to resolve a reduction paradox (the Schrodinger's Cat paradox) in quantum mechanics. This use is demonstrated in the second part. In the third part, the synchronisation (decoherence) of time arrows is discussed. In the fourth part, the synchronisation (decoherence) of time arrows in quantum gravity is considered.

quant-ph↗
arXiv2013

Base of nonlinear dynamics or Real Dynamics, Ideal Dynamics, Unpredictable Dynamics and "Schrodinger cat"

In the paper paradoxes underlying thermodynamics and a quantum mechanics are discussed. Their solution is given from the point of view of influence of the exterior observer (surrounding medium) destroying correlations of system, or boundedness of self-knowledge of system in a case when both the observer, and a surrounding medium are included in system. Concepts Real Dynamics, Ideal Dynamics and Unpredictable Dynamics are entered. Consideration an appearance of a life is given from the point of view of these three Dynamics.

nlin.CD↗
arXiv2013

The Universal Arrow of Time II: Quantum mechanics case

This paper is a natural continuation of our previous paper arXiv:1011.4173 . We illustrated earlier that in classical Hamilton mechanics, for overwhelming majority of real chaotic macroscopic systems, alignment of their thermodynamic time arrows occurs because of their low interaction. This fact and impossibility to observe entropy decrease at introspection explain the second law of thermodynamics. The situation in quantum mechanics is even a little bit easier: all closed systems of finite volume are periodic or nearly periodic. The proof in quantum mechanics is in many respects similar to the proof in classical Hamilton mechanics - it also uses small interaction between subsystems and impossibility to observe entropy decrease at introspection. However, there are special cases which were not found in the classical mechanics. In these cases one microstate corresponds to a set of possible macrostates (more precisely, their quantum superposition). Consideration of this property with use of decoherence theory and taking into account thermodynamic time arrows will introduce new outcomes in quantum mechanics. It allows to resolve basic paradoxes of quantum mechanics: (a) to explain the paradox of wave packet reduction at measurements when an observer is included in the system (introspection) (paradox of the Schrodinger cat); (b) to explain unobservability of superposition of macroscopic states by an external observer in real experiments (paradox of Wigner's friend); (c) to prove full equivalence of multi-world and Copenhagen interpretations of quantum mechanics; (d) to explain deviations from the exponential law at decay of particles and pass from one energy level to another (paradox of a kettle which will never begin to boil).

physics.gen-ph↗
arXiv2013

The Universal Arrow of Time III-IV:(Part III) Nonquantum gravitation theory (Part IV) Quantum gravitation theory

The paper consists of the two independent papers - the first one about Nonquantum Gravitation theory, the second one about Quantum Gravitation theory (Part III: Nonquantum Gravitation theory) The first paper is dealing with the analysis of general relativity theory (theory of gravitation) from the point of view of thermodynamic time arrow. Within this framework "informational paradox" for black holes and "paradox with the grandfather" for time travel "wormholes" are resolved. (Part IV: Quantum gravitation theory) The second paper is dealing with the analysis of quantum gravitation theory from the point of view of thermodynamic time arrow. Within this framework "informational paradox" for black holes and "paradox with the grandfather" for time travel "wormholes", black stars, Penrose's project of new quantum gravitation theory, anthropic principle are considered.

physics.gen-ph↗
arXiv2013

The Universal Arrow of Time V-VI: (Part V) Unpredictable dynamics (Part VI) Future of artificial intelligence - Art, not Science: Practical Application of Unpredictable Systems

The paper consists of the two independent papers:(Part V) We see that exact equations of quantum and classical mechanics describe ideal dynamics which is reversible and leads to Poincare's returns. Real equations of physics describing observable dynamics, for example, hydrodynamic equations of viscous fluid, are irreversible and exclude Poincare's returns to the initial state. Besides, these equations describe systems in terms of macroparameters or phase distribution functions of microparameters. For many systems introduction of macroparameters that allow exhaustive describing of dynamics of the system is impossible. Their dynamics becomes unpredictable in principle, sometimes even unpredictable by the probabilistic way. We will refer to dynamics describing such system as unpredictable dynamics. Dynamics of unpredictable systems is not described and not predicted by scientific methods. Thus, the science itself puts boundaries for its applicability. But such systems can intuitively "understand itself" and "predict" the behavior "of its own" or even "communicate with each other" at intuitive level. (Part VI) Perspective of the future of artificial intellect (AI) is considered. It is shown that AI development in the future will be closer rather to art than to science. Complex dissipative systems whose behavior cannot be understood completely in principle will be the basis of AI. Nevertheless, it will not be a barrier for their practical use.

physics.gen-ph↗
arXiv2013

Comment on "Entanglement and the Thermodynamic Arrow of Time" and Correct Reply on "Comment on "Quantum Solution to the Arrow-of-Time Dilemma"" of David Jennings and Terry Rudolph

Recently David Jennings and Terry Rudolph published two papers as reaction on Maccone's paper "Quantum Solution to the Arrow-of-Time Dilemma". In these papers, the authors suppose that second law of thermodynamics is not relevant for quantum systems. Unfortunately, these papers did not get relevant reply from Maccone. The reason of this is following. Both Maccone and the above-mentioned authors use thermodynamic law and thermodynamic-like terminology for non-thermodynamic systems, for example, microscopic system of three qubits. However, big size of a system (quantum or classic) is also not an enough condition for a system to be macroscopic. The macroscopic system must also be chaotic and has small chaotic interaction with its environment/observer resulting in decoherence (decorrelation). We demonstrate that for relevant thermodynamic macroscopic quantum systems no objection appears.

quant-ph↗
arXiv2013

Hierarchy of protein loop-lock structures: a new server for the decomposition of a protein structure into a set of closed loops

HoPLLS (Hierarchy of protein loop-lock structures) (http://leah.haifa.ac.il/~skogan/Apache/mydata1/main.html) is a web server that identifies closed loops - a structural basis for protein domain hierarchy. The server is based on the loop-and-lock theory for structural organisation of natural proteins. We describe this web server, the algorithms for the decomposition of a 3D protein into loops and the results of scientific investigations into a structural "alphabet" of loops and locks.

physics.chem-ph↗
arXiv2013

Correction of inertial navigation system's errors by the help of video-based navigator based on Digital Terrarium Map

This paper deals with the error analysis of a novel navigation algorithm that uses as input the sequence of images acquired from a moving camera and a Digital Terrain (or Elevation) Map (DTM/DEM). More specifically, it has been shown that the optical flow derived from two consecutive camera frames can be used in combination with a DTM to estimate the position, orientation and ego-motion parameters of the moving camera. As opposed to previous works, the proposed approach does not require an intermediate explicit reconstruction of the 3D world. In the present work the sensitivity of the algorithm outlined above is studied. The main sources for errors are identified to be the optical-flow evaluation and computation, the quality of the information about the terrain, the structure of the observed terrain and the trajectory of the camera. By assuming appropriate characterization of these error sources, a closed form expression for the uncertainty of the pose and motion of the camera is first developed and then the influence of these factors is confirmed using extensive numerical simulations. The main conclusion of this paper is to establish that the proposed navigation algorithm generates accurate estimates for reasonable scenarios and error sources, and thus can be effectively used as part of a navigation system of autonomous vehicles.

eess.SY↗
arXiv2012

Flame front propagation IV: Random Noise and Pole-Dynamics in Unstable Front Propagation II

The current paper is a corrected version of our previous paper arXiv:adap-org/9608001. Similarly to previous version we investigate the problem of flame propagation. This problem is studied as an example of unstable fronts that wrinkle on many scales. The analytic tool of pole expansion in the complex plane is employed to address the interaction of the unstable growth process with random initial conditions and perturbations. We argue that the effect of random noise is immense and that it can never be neglected in sufficiently large systems. We present simulations that lead to scaling laws for the velocity and acceleration of the front as a function of the system size and the level of noise, and analytic arguments that explain these results in terms of the noisy pole dynamics.This version corrects some very critical errors made in arXiv:adap-org/9608001 and makes more detailed description of excess number of poles in system, number of poles that appear in the system in unit of time, life time of pole. It allows us to understand more correctly dependence of the system parameters on noise than in arXiv:adap-org/9608001

nlin.CD↗
arXiv2012

A continuum solvent model: the DISOLV program - algorithms, implementation, and validation

Several implicit (continuum) solvent models are considered: the Polarized Continuum Model (PCM), the Surface Generalized Born model (SGB), and the COnductor-like Screening model (COSMO) as well as their implementation in the form of the DISOLV program. The methods for solving the corresponding equations and for computing the analytic gradients are described. The analytic gradients are used for the fast local energy optimization of molecules in a solvent. An algorithm for the original smooth triangulated molecular surface construction is shortly discussed. The procedure for matching the model parameters and the results of the program application to proteins and ligands with the employment of the MMFF94 force field are described. The validation results show the capability of the program to reach a good accuracy (about several tenth of kcal/mol) in the case of the solvation energy calculation for reasonable time periods at arbitrary shifts of the triangulated grid in use for such large molecules as proteins. A good agreement between the calculated and experimentally measured solvation energies in water is obtained with a root-mean-square deviation about 0.8 kcal/mol for several hundreds of molecules.

physics.chem-ph↗
arXiv2012

Continual Model of Medium I: Algorithm for Formation of Smooth Molecular Surface

In this paper the full and exhaustive algorithm of formation of a smooth molecular Solvent Excluded Surface- SES, and also Solvent Accessible Surface- SAS is presented. These surfaces are a boundary between molecule and solvent. The basis of the algorithm is primary and secondary rolling of molecules. Originality of the paper consists in making of the full and improved algorithm of secondary rolling which allows to create optimal smooth surface SES of any molecule or any set of molecules by rolling any irregularities and close to irregularities situations appearing during primary rolling. The adaptive critical distance characterizing maximal admissible irregularity of a surface is used. The main task, which will be solved by the formed surface and which will be considered in the further papers, is a calculation of solvation energy and its gradients for continual models of solvent. Also it can be used for the demonstration purposes in the molecular editors.

physics.chem-ph↗