33 research outputs found
Sufficient Conditions for Conservativity of Minimal Quantum Dynamical Semigroups
The conservativity of a minimal quantum dynamical semigroup is proved
whenever there exists a ``reference'' subharmonic operator bounded from below
by the dissipative part of the infinitesimal generator. We discuss applications
of this criteria in mathematical physics and quantum probability.Comment: 22 pages, Te
Communication Society and Security: Current Threats and Legal Maintenance
Over many centuries, human societies across the globe have established progressively closer contacts. Recently, the pace of globalization has dramatically increased. Unprecedented changes in communications, transportation, and computer technology have given the process new impetus and made the world more interdependent than ever. Information resources and structures have become a tool for achieving a strategic advantage. The authenticity, credibility, and an adequate reflection of information realities represent the key challenges for the communication society. Our research aims to analyze the possibilities of establishing a profound system for countering legalization of proceeds from crime (money laundering) and creating efficient barriers against cybercrimes, such as hacking of personal data. The sphere of security of online communication processes has become an objective element of our life, and it couldn’t be ignored, especially due to further development of securing biometric personal data mechanisms
Mathematical modeling of cerebral oxygen transport from capillaries to tissue
A non-linear model of oxygen transport from a capillary to tissue is considered. The model takes into account the convection of oxygen in the blood, its diffusion transfer through the capillary wall, and the diffusion and consumption of oxygen in tissue. In the current work, a boundary value problem for the oxygen transport model is studied. The existence theorem is proved and a numerical algorithm is constructed and implemented. The numerical experiments studying the effect of low hematocrit and reduced blood flow rate on cerebral hypoxia in preterm infants are conducted
Digital Economy in the Post-COVID Period: Changes, Communication Processes and Development Prospects
Topicality: Without a doubt, the COVID-19 pandemic has made significant changes in consumer behavior, further strengthening the transition of the global system from the classical economy to the digital economy. In the context of the pandemic, consumer behavior has become even more digital: initially it was associated with health safety standards to limit social face-to-face contacts, and later consumers could not imagine their life without online aggregators of food delivery, documents, clothing, etc. The goal of the research: to conduct a theoretical review of the features of the development of the digital economy and communication strategies of management before the COVID-19 pandemic and already in the post-COVID-19 period. Methods of research: comparative analysis, methods of generalization and classification, historical analysis. Results of the research: the study made it possible to form a theoretical overview of the scientific material and ideas for preparing for a statistical analysis of the global macroeconomic indicators of the digital economy. Practical application: The chapter will be useful for the relevant government agencies (in Russia, for instance, the Ministry of Digital Development) for developing practical recommendations on a broader digitalization of management systems
Local Magnetohydrodynamic Characteristics of the Plasma Stream generated by MPC
This paper investigates the spatial distributions of electrical current which flows inside the plasma stream generated by a magnetoplasma compressor (MPC). Two different modes of MPC operation with different gas supply scenarios have been applied in the experiments presented here. The first is the operation mode with a pulse injection of xenon into the interelectrode space, and the second is the operation mode with residual helium in the chamber and local injection of xenon directly into the compression zone. The maximum value of the electric current observed outside the MPC channel is 15 ÷ 20% of the total discharge current. Electric current vortices were discovered in the plasma stream. The amplitude of the current in the vortices reaches 50% of the total discharge current. The maximum EUV radiation power was measured in the mode of MPC operation with local xenon injection. Power in the wave range 12.2 ÷ 15.8 nm achieves up to 16 ÷ 18 kW
Local Magnetohydrodynamic Characteristics of the Plasma Stream generated by MPC
This paper investigates the spatial distributions of electrical current which flows inside the plasma stream generated by a magnetoplasma compressor (MPC). Two different modes of MPC operation with different gas supply scenarios have been applied in the experiments presented here. The first is the operation mode with a pulse injection of xenon into the interelectrode space, and the second is the operation mode with residual helium in the chamber and local injection of xenon directly into the compression zone. The maximum value of the electric current observed outside the MPC channel is 15 ÷ 20% of the total discharge current. Electric current vortices were discovered in the plasma stream. The amplitude of the current in the vortices reaches 50% of the total discharge current. The maximum EUV radiation power was measured in the mode of MPC operation with local xenon injection. Power in the wave range 12.2 ÷ 15.8 nm achieves up to 16 ÷ 18 kW