bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigations into the accuracy of a pulsed time-of-flight ranging diagnostic sampled at discrete intervals applied to high-velocity targets
Authors: Ota Thomas A. 
Published: July 2021

A non-contact measurement of distance using light pulses is useful in a variety of applications. A time-of-flight measurement, where the time taken for the reflection and detection of an emitted light pulse is measured, is a conceptually simple way of determining the distance. The attainable accuracy of a time-of-flight measurement can be considered a parameter estimation problem, where the underlying parameters of the detected pulse need to be estimated from a number of measurements. The consideration of a single pulse is particularly relevant in applications such as explosively driven or high-speed impact experiments where velocities are large. This estimation problem was investigated considering a temporal Gaussian pulse sampled at fixed intervals to determine an expression for attainable uncertainty. Results are compared from maximum likelihood estimation analysis, a Monte Carlo model, and experimental measurements. The results from the different approaches are largely comparable and, furthermore, describe how the accuracy of a single-pulse time-of-flight measurement may be affected by variables such as sampling interval, pulse shape, and noise. Finally, time-of-flight measurements are conducted in a dynamic setting measuring a target moving at velocities of up to 300 m s−1. The achieved uncertainties were similar to those predicted.
Turbulent flow of liquid lead alloy in oxygen-controlled corrosion erosion test facility
Authors: Fetzer Renate , Weisenburger Alfons , Mueller Georg 
Published: July 2021

The CORELLA (CORrosion Erosion test facility for Liquid Lead Alloy) facility allows corrosion erosion tests in molten lead alloys at controlled oxygen content and temperature under flowing conditions. Its exposure chamber consists of a cylindrical container, partially filled with the liquid metal. An inner rotating cylinder drives the liquid metal flow. The specimens of interest are fixed vertically inside the chamber such that the lead alloy flows around the specimens on both sides. In this numerical study, the turbulent flow of liquid lead–bismuth eutectic is solved for various specimen configurations, filling heights, and rotational speeds of the inner cylinder. Hereby, the deformation of the free liquid surface is taken into account using a rotationally symmetric approximation. Highly turbulent flow is found even for 200 rpm (revolutions per minute), the lowest rotational speed investigated. The velocity of the liquid metal along the specimens’ lateral surfaces reaches values up to 1.5 m/s for a rotational speed of 1200 rpm, the limit of experimentally stable conditions. Due to the sudden flow constrictions and expansions around the specimens, a much higher effect of the flow on corrosion erosion is expected than for simple pipe flow at the same bulk velocity.
Matrix lumican endocytosed by immune cells controls receptor ligand trafficking to promote TLR4 and restrict TLR9 in sepsis
Authors: Maiti George , Frikeche Jihane , Lam Carly Yuen-Man , Biswas Asim , Shinde Vishal , Samanovic Marie , Kagan Jonathan C. , Mulligan Mark J. , Chakravarti Shukti 
Published: July 2021

SignificanceSepsis is a life-threatening inflammatory disease of dysregulated innate immune cells. Extracellular matrix (ECM) interactions with immune cells are important in this context and require deeper insights. We show that immune cells ingest lumican, a ubiquitous ECM protein produced by fibroblasts, to heighten their response to bacteria but restrict their response to viral or degraded self-DNA released from dead cells. Sepsis patients have elevated circulating lumican, and mice lacking lumican show poor bacterial clearance and resolution of sepsis but elevated response to DNA. Lumican may play a dual protective role in barrier ECM tissues, one of promoting bacterial defense and another of limiting antiviral and autoimmune inflammatory responses.
Inhalable nanocatchers for SARS-CoV-2 inhibition
Authors: Zhang Han , Zhu Wenjun , Jin Qiutong , Pan Feng , Zhu Jiafei , Liu Yanbin , Chen Linfu , Shen Jingjing , Yang Yang , Chen Qian , Liu Zhuang 
Published: July 2021

Significance
The recently emerged SARS-CoV-2 variants are more transmissible, which brings new challenges to vaccine treatment. There is an urgent global need for alternative strategies that could effectively and rapidly prevent the infection of various SARS-CoV-2 variants. Herein, we design human angiotensin-converting enzyme II (hACE2)–containing nanocatchers (NCs) derived from genetically engineered cells stably expressing hACE2 as the competitor with host cells for virus binding to protect cells from SARS-CoV-2 infection. An inhalable formulation fabricated by NCs and the mucoadhesive excipient hyaluronic acid could significantly prolong the retention of NCs in the lung and exhibits potent pseudovirus inhibition ability in an hACE2-expressing mouse model. Importantly, the inhalable NCs in the lyophilized formulation allow long-term storage, facilitating their future clinical use.
Ongoing global and regional adaptive evolution of SARS-CoV-2
Authors: Rochman Nash D. , Wolf Yuri I. , Faure Guilhem , Mutz Pascal , Zhang Feng , Koonin Eugene V. 
Published: July 2021

Significance
Understanding the ongoing evolution of SARS-CoV-2 is essential to control and ultimately end the pandemic. We analyzed more than 300,000 SARS-CoV-2 genomes available as of January 2021 and demonstrate adaptive evolution of the virus that affects, primarily, multiple sites in the spike and nucleocapsid protein. Selection appears to act on combinations of mutations in these and other SARS-CoV-2 genes. Evolution of the virus is accompanied by ongoing adaptive diversification within and between geographic regions. This diversification could substantially prolong the pandemic and the vaccination campaign, in which variant-specific vaccines are likely to be required.
Chiral dynamics and Zitterbewegung of Weyl quasiparticles in a magnetic field
Authors: Hu Xi-Dan , Li Li-Yan , Guo Zheng-Xin , Li Zhi 
Published: July 2021

Abstract
The relativistic dynamical properties of chiral Weyl quasiparticles (WQPs) are investigated in a stationary magnetic field. The visualized evolution process of quasiparticles’ wavepackets has been calculated with different angles between the spinor and the magnetic field. The results reveal that the chiral WQPs feature anisotropic dynamics, which falls into two typical motion modes, i.e. directional drift (chiral magnetic effect) and periodic oscillation (chiral Zitterbewegung). We theoretically find that the mechanism behind this interesting dynamical phenomenon is the special chiral relativistic Landau level. Since the frequency, amplitude and drift velocity of chiral WQPs can be controlled in a measurable range, one can expect the observation of the phenomenon in the cold atomic system.
Improvements of the programmable quantum current generator for better traceability of electrical current measurements
Authors: Djordjevic Sophie , Behr Ralf , Drung Dietmar , Götz Martin , Poirier Wilfrid 
Published: July 2021

Abstract
A programmable quantum current generator based on the application of Ohm’s law to quantum voltage and resistance standards has demonstrated a realization of the ampere from the elementary charge with a 10−8 relative uncertainty (Brun-Picard et al 2016 Phys. Rev. X 6 041051). Here, we report on improvements of the device leading to a noise reduction of the generated quantized current. The improved quantum current generator is used to calibrate different ammeters with lower measurement uncertainties. Besides, measurements of its quantized current using a calibrated ultrastable low-noise current amplifier have shown that the realizations of the ampere at PTB (Physikalisch-Technische Bundesanstalt) and LNE (Laboratoire national de Métrologie et d’essais) in the range ±50 μA agreed to −3.7 parts in 107 with a combined standard uncertainty of 3.1 parts in 107 (coverage factor k
c = 1).
Comparative analysis of linear electromechanical steering drives with an autonomous hydraulic drive
Authors: Abdulin R R , Bolshakov V V , Podshibnev V A , Rozhnin N B , Samsonovich S L 
Published: July 2021

Abstract
The work is devoted to the topical problem of choosing a scheme of a linear electromechanical drive, developed as an alternative to an autonomous electro-hydraulic drive. Mass characteristics of the main functional elements of the actuators: electric motors and ball screws are considered. Synchronous motors and a collector motors were considered in this work as an electric motor. Ball-screw transmissions with separator and ball-screw transmissions with recirculation of balls were considered in this work as a ball-screw transmission. Comparison was made according to functional, technological and economic criteria of two schemes for construction of linear electromechanical drives: with intermediate mechanical transmission based on a collector motor and based on a permanent magnet synchronous motor without an intermediate mechanical transmission. The comparison showed that the scheme with an intermediate mechanical transmission has better mass characteristics compared to the scheme without an intermediate mechanical transmission with similar dynamic characteristics. The presented comparison results can be useful in solving the problem of choosing schemes for newly developed electric electromechanical steering drives.
Modeling technique for advanced adaptive aircraft catapult devices
Authors: Beklemishchev F S , Tikhonov K M 
Published: July 2021

Abstract
This article represents approaches to the configuration and modeling of adaptive aircraft catapult devices intended for forced separation of aircraft guided missiles from the air vehicle. The creation of such a device is a promising direction of research. The adaptability of such a device lies in the fact that in all air vehicles flight modes, the necessary and safe parameters for separating the air weapons from the carrier are provided. One of the variants of such a device with a hydraulic executive part is considered, its main parameters are determined to meet the requirements for the compartment safety and the possibility of regulating the flow of this process. The computer modeling technique is based on the use of approved information technologies SolidWorks, SimInTech and EULER, which allow solving multiphysics tasks, as well as reducing the full-scale experiments volume due to their use. As a result of comparing the results of mathematical modeling and experimental studies, it was found that the model of the adaptive aircraft catapult devices, developed on the basis of the methodology, describes the processes of payload movement fairly accurately.
Bird colony algorithm use in the logistics module of the production management system
Authors: Belousov I A , Firsov K I 
Published: July 2021

Abstract
The report discusses the application of the bird colony algorithm together with the solution of the clustering problem in the logistics module of the ERP-system. This polynomial algorithm belongs to the category of stochastic biotic algorithms. The main rule of the implementation of the bird colony algorithm is that the so-called swarm intelligence is used to solve the optimization problem. The article describes the rule of algorithm operation, the study of the properties of this algorithm based on the results of modeling on a real base of target points and makes a comparative analysis of the algorithm with previously used algorithms in the system. The application of the algorithm in matrix form using the entropy matrix is described in the report. The obtained results allow us to say with confidence that the use of the bird colony algorithm can significantly increase the algorithm speed of logistic module.
Non-parametric tuning of PID Controllers: Evolution of ideas
Authors: Boiko Igor 
Published: July 2021

AbstractNon-parametric tuning was introduces by J. Ziegler and N. Nichols with the step test and continuous cycling tests and the respective tuning rules. Whereas the step test based tuning had some feature of parametric tuning, the continuous cycling test based tuning was purely non-parametric. The latter test involves bringing the system under proportional control into a sustained oscillation and measuring the frequency of these oscillations and fixing the gain value, that are called the ultimate frequency and ultimate gain. The test was intended for manual tuning of PID controllers. It is relatively hard to automate, and it is not used in auto-tuners. Another test, called relay feedback test (RFT), was proposed by K. Astrom and T. Hagglund to excite self-oscillations through the inclusion of a nonlinear element (relay) in the control loop. This test is easier to automate, and it found applications in industrial auto-tuners. In both these tests ultimate frequency coincides with the phase cross-over frequency of the process/plant. Yet, both the original continuous cycling test and the RFT suffer from such a drawback as the change of the phase cross-over frequency after PID controller introduction. A new test, the modified relay feedback test (MRFT), which can ensure that the test oscillations are excited at he frequency that becomes the phase cross-over frequency after introduction of a controller in the loop, was recently introduced. This property is attained throughcoordinated test and tuning, which is considered in the book chapter. Moreover, the tuning rules are optimized for a selected class of processes, which offers the paradigm ofoptimal non-parametric tuning.
Public transport synchronization problem and the possibility of its compliance with social distances on the example of regional airport hubs
Authors: Borodavkin V A , Kapitonov Yu A 
Published: July 2021

AbstractThe problem of organizing passenger transfers at regional airport hubs in terms of the pandemics is considered in the article. On the one hand, public transport has become a dangerous place for the spread of diseases. On the other hand, it is necessary for the existence of key sectors of the economy. A mathematical model of the synchronization of the arrival and departure of aircraft is proposed as the assignment problem. Unlike other available models, the goal is to slow down the speed of passenger flows with the ability to maintain social distance in the area of the transfer airport. The proposed model has a fan pattern schedule scheme, in which, until a certain estimated time, only arrival of vehicles is carried out and after this estimated time only departure. Aviation regional interchange hubs located in the Siberian part of the Russian Federation were considered in numerical experiments. To detail the restrictions, the service regulations for transit flights on domestic airlines were used. Thus, it is proposed to implement one of the concepts of transport operation in a pandemic, especially to abandon the speed as a service in favor of passengers’ safety.
Game control of air strikes against a recoverable ground facility
Authors: Bukhalev V A , Boldinov V A , Skrynnikov A A 
Published: July 2021

Abstract
The current task is dedicated to the problem of developing minimax game control in pure strategies when two enemies (an aviation group and a repair team) act against each other. The first one destroys an object and the second one repairs it. The algorithm of optimal controlling process based on the average risk criterion does not guarantee a result of the governance. It happens because of both enemies observe and conduct the object’s structure. Optimal solutions are based on the Systems theory with a random jumping structure and the Game theory too. The controlled object is described by dynamic stochastic system with a random jumping structure which has a finite number of possible states. Transitions from one state to another occur at random moments of time and they are controlled by two warring parties (the aviation group and the repair team) pursuing strictly opposite goals. State changing process of the object’s structure is assessed by indicators of players which are worked with errors. Some kind of object’s state functionality is a criterion for the optimality of controlling processes. One party seeks to minimize it and the other one seeks to maximize it. Players control the object’s structure in clean strategies applying the final number of possible strategies. The optimal controlling processes are among the class of non-stochastic mathematical dependencies on the observations results which are preceded the current moment.
Overview of automation tools for avionics verification
Authors: Dyachenko S A , Ilyashenko D M , Neretin E S 
Published: July 2021

Abstract
The existing verification automation tools for civil aircraft avionics are considered (particularly, formal methods, hardware-in-the-loop testing, outsource sendees). Key solutions presented on the market are described, their advantages and weak points are identified. Also, it is determined a promising field is the automation of graphic and aural information testing during the cockpit human-machine interface assessment (e.g. for cockpit display and flight warning systems). This type of verification is practically not automated nowadays. The architecture of a complex for the mentioned task is proposed, the methodology of verification using the described tool is considered either. The camera and microphone usage for monitoring of images and sound alerts which is being outputted to the crew allows applying of computer recognition algorithms during verification. It will allow reducing the time and cost expenses for human-machine interface testing as well as reducing the probability of mistakes could be made during fully manual testing. In addition, the proposed concept makes its application possible for any technical objects with a user interface in other industry areas (not just in aviation) such as space, automotive, shipbuilding, etc.
Development of a distributed microprocessor control system for the 6 degree of freedom motion simulator
Authors: Efromeev A G , Goryachev O V , Morozov O O 
Published: July 2021

Abstract
The article deals with the design issues of a microprocessor control system for the 6 degrees of freedom motion simulator. This motion simulator is a high performance, electro-pneumatic simulator, used for test evaluation of small high dynamic flying objects. With pneumatic actuated yaw and pitch axes and an electric motor on the roll axis, the Motion simulator reproduce, in real-time, the flight motions of the actual object. The presence of a large number of servo drives with different types of executive elements in the Motion simulator required the development of a distributed multiprocessor control system. The equipment of the Motion simulator includes a number of microprocessor control units. Each contains a microprocessor control system with high-performance microcontroller having specialized peripherals, as well as equipped with all the necessary communication interfaces. Control units are maximally unified, which significantly reduces the time of their development and debugging. Due to this, units firmware is mostly identical and uses the same set of libraries.
Synthesis of an algorithm for controlling an electric servo drive with a hybrid stepper motor
Authors: Goryachev O V , Stepochkin A O 
Published: July 2021

Abstract
One of the promising directions in the development of an electric servo drive systems is the use of a hybrid stepper motor without a rotor position sensor in precise positioning systems. A procedure for synthesizing an algorithm for controlling an electric servo drive based on a hybrid stepper motor is considered. A method is proposed for switching the windings of an operating motor, which makes it possible to exclude resonance phenomena in the drive power system. An algorithm for vector control of the torque of a stepper motor is developed using the algorithm for observing the speed and angle of rotation. A simulation model of the electric servo drive with vector control and adaptive speed observer has been developed in the package Simulink. The effectiveness of the proposed methods for controlling the operating motor is confirmed by the results of dynamic modeling.
Expert assessment of the cockpit crew information and control field
Authors: Greshnikov I I , Salnikov T D , Ivanov A S 
Published: July 2021

Abstract
This paper discusses the method of expert assessment based on the probabilistic approach of the paired comparisons method. This mathematical apparatus is the basis for special software integrated into the universal stand for prototyping the cockpit, which allows for a systematic expert assessment at this stand according to pre-selected criteria with the control of the consistency of the answers. Using this method, the task of determining the feasibility of displaying layers of synthetic and enhanced vision on the flying frame is solved, but in general, the method allows evaluating any elements of the displays and controls.
Movement of a group of unmanned aerial vehicles in formation
Authors: Heiss E A 
Published: July 2021

Abstract
This paper presents a method for organising the movement of unmanned aerial vehicles in formation. In the presented method of UAV collisions are prevented by a modification of the potential field method. The movement of the group is accomplished by incrementing the origin coordinates of the formation at each iteration of data exchange between UAVs. This paper presents a graph showing the negligible positioning error of drones in formation over time as the heterogeneous swarm of quadcopters moves towards the target position. Simulation results show that the flight time of a group of UAVs to the target swarm position using the proposed method is longer than using the master-slave method. The model of a Wi-Fi network as an information exchange network between UAVs was used in the developed simulation environment. This approach facilitates the implementation of the presented method on real aircrafts.
Software package for simulating a group of unmanned aerial vehicles performance
Authors: Kim R V , Frolova D V , Borovkov A S 
Published: July 2021

Abstract
The paper presents the architecture of a software, designed to simulate the functioning of a group of unmanned aerial vehicles. The software consists of two components: software for modeling unmanned aerial vehicles functioning processes, which designed to simulate the controlled movement of a single UAV and to simulate the functioning of its onboard systems and software for the ground control post, which designed to form a flight task, generate and send control commands to the UAV, and receive information from the UAV about its current state. The paper also discusses the unmanned aerial vehicle group application scenario, main functions of each software components, its user interface as well as implemented models and algorithms.
Formation and research of UAV safety models and observability of objects when monitoring the fire setting
Authors: Kozorez D A , Mokrova M I , Kim N V 
Published: July 2021

Abstract
Fire monitoring with the use of an unmanned aerial vehicle is a two-criterion task, since there is a need to maximize the vehicle protection against the thermal influence of the fire, as well as to increase the observability as much as possible achieved by reducing the flight height. This paper contains empirical models, representing the flight safety of an unmanned aerial vehicle and the observability of the target objects during fire situation monitoring. The proposed models allow to consider the peculiarities of the monitoring conditions., using a car as a sample target. The analysis of the proposed models is carried out, and the relevant quantitative results are provided. The work defines the criteria for the selection of an optimum aerial vehicle flight height over the area under surveillance, and they are generated, using an expert assessment database.