Quantum-secured blockchain

Blockchain is a distributed database which is cryptographically protected against malicious modifications. While promising for a wide range of applications, current blockchain platforms rely on digital signatures, which are vulnerable to attacks by means of quantum computers. The same, albeit to a lesser extent, applies to cryptographic hash functions that are used in preparing new blocks, so parties with access to quantum computation would have unfair advantage in procuring mining rewards. Here we propose a possible solution to the quantum era blockchain challenge and report an experimental realization of a quantum-safe blockchain platform that utilizes quantum key distribution across an urban fiber network for information-theoretically secure authentication. These results address important questions about realizability and scalability of quantum-safe blockchains for commercial and governmental applications.Comment: 7 pages, 2 figures; published versio

Development of mathematical model for study of electromagnetic compatibility of the frequency-controlled electric drive with the power supply and electric motor.

В статье рассматривается задача построения математической модели для исследования электромагнитной совместимости частотно-регулируемого электропривода с питающей сетью и двигателем. Модель строится на основе элементов из библиотеки SimPowerSystems приложения Simulink пакета MATLAB. Приводятся примеры результатов моделирования и оценки электромагнитной совместимости.The article discusses the еtask of constructing a mathematical model for study of electromagnetic compatibility of frequency-controlled electric drive with the power supply and electric motor. The model is based on elements from the SimPowerSystems Library of MATLAB Simulink application. Examples of the simulation results of and estimation of electromagnetic compatibility are shown

Modelling of electromechanical processes of electric drive on the example of one of the coordinates (the rotation mechanism) of an industrial robot-manipulator TOUR-10

The article describes the stages of development and preparation of mathematical models of kinematics and actuator control for robot manipulator TOUR-10. The mathematical model includes 3 stages of modeling. The first step is to create a mathematical model of electric drive control system of the robot manipulator and the analysis of obtained transients of the stator current, speed and position of the motor shaft. The second step is to create a mathematical model of the mechanical system of the robot manipulator. The third stage is the creation of complex Electromechanical systems of a robot manipulator.В статье описываются этапы разработки и подготовки математической модели одной из координат (механизма поворота) кинематики и системы управления электропривода для многозвенного робота манипулятора ТУР-10. Математическая модель включает в себя 3 части моделирования. Первая часть – это создание математической модели системы управления электроприводом робота манипулятора и анализ полученных переходных процессов тока статора, скорости и положения вала двигателя. Вторая часть – это создание математической модели механической системы робота манипулятора. Третья часть – это создание комплексной электромеханической системы робота манипулятора

State and prospects using hardware-software simulator electrical complex in educational process

The problems of the use of real-time simulation in the educational process in the study of subjects related to the development of electric systemsРассматриваются вопросы использования симуляторов реального времени в учебном процессе при изучении дисциплин, связанных с освоением систем электроприводо

Research of a bi-directional DC-DC converter integrated in electric car power installation

This article presents the results of the simulation study of the bi-directional DC converter, including the time diagrams of the electric vehicle speed, voltage and current changes in various experiments, Also presented are the results of efficiency change and charge level, when using a bi-directional converter as well as without using it. The HFEDC (Highway Fuel Economy Driving Schedule) model was chosen for the simulation of the electric vehicle drive model using units simulating standardized driving cycles and as an algorithm for changing the vehicle's control signal. Studies of the operating modes of the electrical equipment and the electric vehicle with the DC voltage conversion device in the power circuit of the DC source have been carried out by computer simulation in specialized programs for the study of dynamic systems. The simulation model of the reversible DC converter in the electrical power equipment of an electric vehicle was constructed on the basis of mathematical models of the individual elements reflecting their real physical properties. The present solution is the use of two-way DC voltage converters in the power conversion systems of modern electric drives, including the electric propulsion systems of prospective vehicles improves the efficiency of these systems. © Published under licence by IOP Publishing Ltd

Vulnerability of primitive human placental trophoblast to Zika virus

Infection of pregnant women by Asian lineage strains of Zika virus (ZIKV) has been linked to brain abnormalities in their infants, yet it is uncertain when during pregnancy the human conceptus is most vulnerable to the virus. We have examined two models to study susceptibility of human placental trophoblast to ZIKV: cytotrophoblast and syncytiotrophoblast derived from placental villi at term and colonies of trophoblast differentiated from embryonic stem cells (ESC). The latter appear to be analogous to the primitive placenta formed during implantation. The cells from term placentas, which resist infection, do not express genes encoding most attachment factors implicated in ZIKV entry but do express many genes associated with antiviral defense. By contrast, the ESC-derived trophoblasts possess a wide range of attachment factors for ZIKV entry and lack components of a robust antiviral response system. These cells, particularly areas of syncytiotrophoblast within the colonies, quickly become infected, produce infectious virus and undergo lysis within 48 h after exposure to low titers (multiplicity of infection > 0.07) of an African lineage strain (MR766 Uganda: ZIKVU) considered to be benign with regards to effects on fetal development. Unexpectedly, lytic effects required significantly higher titers of the presumed more virulent FSS13025 Cambodia (ZIKVC). Our data suggest that the developing fetus might be most vulnerable to ZIKV early in the first trimester before a protective zone of mature villous trophoblast has been established. Additionally, MR766 is highly trophic toward primitive trophoblast, which may put the early conceptus of an infected mother at high risk for destruction

Invistigation of the Dynamic Characteristics of a Synchrounus Generator (on the Example of the Hydro Generator Nurek HPP)

The modern electric power system is a complex structure with constantly changing parameters of the operation, as well as abnormal operation. Dynamic characteristics of a synchronous generator are characterized by parameters that affect the transient process when the operating mode changes. This article considers the effect of automatic excitation control (AEC) on the dynamic characteristics of a synchronous generator by mathematical simulation in the Matlab/Simulink environment. AEC will play a significant role in enhancing the stability of generators and the electric power system as a whole. The results of the study are presented.Современная электроэнергетическая система представляет собой сложную структуру с постоянно изменяющимися параметрами режима, а также при анормальных режимов. Динамические характеристики синхронного генератора характеризуются параметрами, влияющими на переходный процесс при изменении режима работы. В данной статье рассматривается влияние автоматического регулирования возбуждения (АРВ) на динамические характеристики синхронного генератора путем математического моделирование в среде Matlab/Simulink. АРВ играет значительную роль в повышение устойчивости генераторов в электроэнергетические системы в целом. Приведены результаты исследования

ПРОФИЛАКТИКА РАНЕВЫХ ОСЛОЖНЕНИЙ У БОЛЬНЫХ ИШЕМИЧЕСКОЙ БОЛЕЗНЬЮ СЕРДЦА С НИЗКОЙ ФРАКЦИЕЙ ВЫБРОСА СЕРДЦА

Low cardiac output and circulatory insufficiency is a risk factor for wound complications in operated patients with coronary heart disease (CHD). The analysis of the number of wound complications in patients with coronary artery disease with low ejection fraction of the heart underwent CABG has done. Two clinical groups has for medin which the sternum fixation and suturing surgical approach produced by traditional (control group) and original (main group) methods. In the study group the number of wound complications was significantly lower and it was allowed to offer this method as a prophylactic.Низкий сердечный выброс и недостаточность кровообращения является фактором риска возникновения раневых осложнений у оперированных больных ишемической болезнью сердца (ИБС). Проведен анализ количества раневых осложнений у больных ИБС с низкой фракцией выброса сердца, перенесших коронарное шунтирование. Сформированы две клинические группы, у которых остеосинтез грудины и ушивание операционного доступа произведены по традиционной (контрольная группа) и оригинальной (основная группа) методикам. В основной группе больных количество раневых осложнений достоверно ниже, что позволило предложить данный метод в качестве профилактического.