A new key exchange protocol based on the decomposition problem

In this paper we present a new key establishment protocol based on the decomposition problem in non-commutative groups which is: given two elements $w, w_1$ of the platform group $G$ and two subgroups $A, B \subseteq G$ (not necessarily distinct), find elements $a \in A, b \in B$ such that $w_1 = a w b$. Here we introduce two new ideas that improve the security of key establishment protocols based on the decomposition problem. In particular, we conceal (i.e., do not publish explicitly) one of the subgroups $A, B$, thus introducing an additional computationally hard problem for the adversary, namely, finding the centralizer of a given finitely generated subgroup.Comment: 7 page

Numerical methods for construction reachability sets of dynamical systems

The research is devoted to the problem of reachability sets construction and representation in a control problem of a dynamical system. The paper discusses two numerical methods for construction reachability sets of dynamical systems. These methods differ in the way of representations of the reachability sets. The first method is oriented on solution of the control problem on the plane and connected with a representation of sets in the form of polygons. The second one is connected with a pixel representation of sets in the m-dimensional Euclidian space and simplicial complexes. © 2012 American Institute of Physics

CONTROL SYSTEM DEPENDING ON A PARAMETER

A nonlinear control system depending on a parameter is considered in a finite-dimensional Euclidean space and on a finite time interval. The dependence on the parameter of the reachable sets and integral funnels of the corresponding differential inclusion system is studied. Under certain conditions on the control system, the degree of this dependence on the parameter is estimated. Problems of targeting integral funnels to a target set in the presence of an obstacle in strict and soft settings are considered. An algorithm for the numerical solution of this problem in the soft setting has been developed. An estimate of the error of the developed algorithm is obtained. An example of solving a specific problem for a control system in a two-dimensional phase space is given

Control of the combustion process and emission formation in marine gas engines

A smooth transition to the use of gas engines instead of conventional engines in marine shipping is a logical pathway for compliance with tightening environmental regulations. Currently, five major gas engine concepts are applied in maritime sector. In this paper, a review of the marine gas engine concepts was performed with a focus on the control of combustion and emission. To assess all the contributors to combustion and the emission formation process, three main factors were outlined: design, operational parameters and fuel. The assessment of gas engines was conducted based on these factors. The present paper helps to provide an understanding of the current progress in the development of marine gas engines towards improving of combustion efficiency and reducing the emissions. Moreover, the knowledge gaps, particularly in four-stroke marine high-pressure gas engines, were identified.acceptedVersio

ANALYSIS OF DESIGN FEATURES OF FLEXIBLE PAVEMENTS ON FEDERAL HIGHWAYS IN RUSSIA

Abstract. Nowadays the pavements of highways in Russia work under difficult conditions of constantly growing traffic volume. The current method for flexible pavements design has a number of serious disadvantages. It does not take into complete account the best practices in design and the actual operating conditions for highways. In a number of cases, this leads to the design of inefficient structures of pavements with a short service life.On a number of federal roads, there are observed rutting and premature wear out of road surface in the first years of the operation. Drainage sand layers and shallow drainage drains are quickly working out. Geosynthetic materials are sometimes used unreasonably. The design life of pavements does not comply with the current standards. In Russia the effective road construction materials are not yet completely used up, as well as local materials reinforced with astringents. The actual experience in operating various road structures with the identification of the most optimal solutions is still poorly considered, except for certain regions.Thus, an urgent need has arisen to develop standard designs of pavements for various natural and climatic conditions in Russia ensuring pavements' efficient operation. It is necessary to analyze the existing pavement designs on the federal highways under various road building climatic zones to develop the standard pavement designs.Keywords: flexible pavements, typical constructions of pavements

Trusted Hart for Mobile RISC-V Security

The majority of mobile devices today are based on Arm architecture that supports the hosting of trusted applications in Trusted Execution Environment (TEE). RISC-V is a relatively new open-source instruction set architecture that was engineered to fit many uses. In one potential RISC-V usage scenario, mobile devices could be based on RISC-V hardware. We consider the implications of porting the mobile security stack on top of a RISC-V system on a chip, identify the gaps in the open-source Keystone framework for building custom TEEs, and propose a security architecture that, among other things, supports the GlobalPlatform TEE API specification for trusted applications. In addition to Keystone enclaves the architecture includes a Trusted Hart -- a normal core that runs a trusted operating system and is dedicated for security functions, like control of the device's keystore and the management of secure peripherals. The proposed security architecture for RISC-V platform is verified experimentally using the HiFive Unleashed RISC-V development board.Comment: This is an extended version of a paper that has been published in Proceedings of TrustCom 202

Empirical normal intensity distribution for overtone vibrational spectra of triatomic molecules

Theoretical calculations are contributing a significantly higher proportion of data to contemporary spectroscopic databases, which have traditionally relied on experimental observations and semi-empirical models. It is now a common procedure to extend calculated line lists to include ro-vibrational transitions between all bound states of the ground electronic state up to the dissociation limit. Advanced ab initio methods are utilized to calculate the potential energy and dipole moment surfaces (PESs and DMSs), and semi-empirical PESs are then obtained by combining ab initio and experimental data. The objective is to reach high accuracy in the calculated transition intensities for all parts of spectrum, i.e. to increase the predictive power of the model. We show that in order to perform this task, one needs, in addition to the standard improvements of the PES and DMS in the spectroscopically accessible regions, to extend the ab initio calculations of the PES towards the united-atom limit along the stretching coordinates. The argument is based on the correlation between the intensities of high-overtone transitions and the repulsive potential wall that has previously been theoretically established for diatomic molecules and is empirically extended here to linear and nonlinear triatomic molecules. We generate partial line lists for water and ozone, and together with an already available line list for carbon dioxide, we derive the normal intensity distribution, which is a direct consequence of this correlation. The normal distribution is not an instrument to compute highly accurate intensities, rather it is a means to analyze the intensities computed by the traditional methods