bluuebunny/crossref_metadata_2025_split huggingface dataset:
H-infinity approach to design optimal output control for the aggregated interpolation model of helicopter motion
Authors: Kudryavtseva I , Efremov A , Panteleev A 
Published: September 2020

Abstract
This paper presents the problem of designing a feedback control of the aggregated model describing helicopter flight dynamics under the influence of exogenous factors based on the H-infinity approach. The original nonlinear equations of dynamics are assumed to be linearized regarding to several flight modes that characterize with a set of precisely specified flight conditions such as an attitude of an aircraft, its forward speed and turn rate. Matrices of the linearized systems are dependent on the speed of the aircraft. Due to that the aggregated model comprises eight submodels corresponding to flight modes when the speed varies from hover to 140 kts in a certain regular interval. The proposed principle of designing includes two stages: on the first stage the feedback control input is selected for each submodel separately so that the H-infinity norm of the value functional with respect to the H-infinity norm of disturbances is minimum; on the second one the interpolation technique lying in the expansion of matrices in the basis of finite functions is applied. The solution method is experienced on three helicopter models: ZD559-Lynx, the twin engine, utility helicopter in the 4.5 -ton category; S123-Bo105, the twin engine helicopter in the 2.5 ton class; SA330-Puma, the twin engine, medium-support helicopter in the 6-ton category.
Use of fuzzy areas of preference in tasks of multi – criteria evaluation of freight air transport
Authors: Sudakov V , Sivakova T 
Published: September 2020

Abstract
This paper shows how, based on the theory of fuzzy sets, the problem of multi-criteria selection of cargo planes is solved. It is proposed to determine fuzzy preference intervals on the scales of aircraft efficiency criteria. At the same time it is allowed to intersect such intervals taking into account the limitations on the maximum and minimum degree of belonging of criterion values. For combinations of fuzzy intervals, Decision Maker makes its judgments on a fuzzy preference scale. The resulting aircraft efficiency model is checked for coverage of all points of the criterion space with a level of preference not lower than the specified one. This model can be used to estimate any number of cargo aircraft in automatic mode. Both clear and fuzzy criterion values can be submitted to the model input, and then the method allows to build the functions of aircraft belonging to all areas of preference. The software implementation of this model can be used to make decisions about the purchase, manufacture, repair of certain types of aircraft and to determine which types of aircraft should be decommissioned.
Analyzing models of air equilibrium composition calculation
Authors: Emelyanov V N , Karpenko A G , Tolstoguzov S S , Volkov K N 
Published: September 2020

Abstract
The atmospheric composition behind a normal shock ahead of a hypersonic vehicle differs from the atmosphere ahead of the shock. Various models of air equilibrium composition are compared, analysis of areas of these models applicability is performed. Numerical simulations of flow in a channel with a step are performed using models of perfect gas and high-temperature air. The results computed with both models are compared.
Studying the applicability of a pulsed magnetic field to biological tissues
Authors: Podolskaya N , Kovalev K , Popov V 
Published: September 2020

Abstract
In biomedicine, there are still a number of issues to be solved and studied. One of them is the treatment of cancer and the problem of gene modification by a non-invasive method. The authors propose a method of using a magnetic field (MF) to solve these issues, in particular, the use of magnetic field strength and eddy currents when exposed to biological tissue. The article describes the mathematical calculations and an experiment model necessary to consider the reactions of healthy and cancer cells to MF. The article highlights prospects for the development of this area.
The strength tests of thin-walled composite shells under non-stationary loads of different physical nature
Authors: Ostrik A V , Bakulin V N , Nikolaev D N 
Published: September 2020

Abstract
Mechanical action of energy fluxes of different physical nature is proposed to be simulated by one-side non-stationary loading. A set of gas-dynamic devices for generation of loads of the required space-time distribution is described. Two new explosive devices for formation of low-impulse loads of microsecond duration are proposed. The methods to measure the parameters of thin-walled composite constructions under dynamic and pulse loads are considered. Time deformation profiles of fiberglass cylindrical shell under low-impulse load of microsecond duration are given. The use of wire or foil sensors for the measurement of deformations gives close results when investigating the shell stage of deformation of fiberglass thin-walled constructions.
How to reduce the probability of erroneous decisions in the systems of collective intelligence
Authors: Protasov V , Potapova Z , Akhobadze G 
Published: September 2020

Abstract
This work discusses and solves the methodological problem of reducing the probability of erroneous decisions when solving local problems by groups of intelligent agents. Intellectual agents can be carriers of both natural and artificial intelligence. The basic method of the new information technology is based on the theory of evolutionary decision reconciliation developed by the authors. The method is built on the original use of genetic algorithms in which intelligent agents perform the fitness function based on their knowledge and skills. The technology is based on the knowledge model proposed during the work, the Rasch model, and the mathematical apparatus of the Condorcet theorem. A theorem that allows finding the conditions under which the probability of an erroneous solution tends to zero, is formulated and proved. The results of using the theory for objects recognition from images by a group of neural networks are presented. A significant decrease in the probability of errors of the first kind is obtained in comparison with the classical methods. It is proposed to use the technology of evolutionary decision reconciliation to solve local problems in medical diagnostics, banking, and other fields.
Distributed computing based on Container-component model
Authors: Semenov A 
Published: September 2020

Abstract
Cloud computing focuses on scalability, elasticity, and cost-efficiency of the service. In this context, shifting towards the concept of “algorithm as a service” is a contemporary issue. The three main drivers of it includes, machine learning, artificial intelligence, and Digital Earth. The following assumption was made throughout the article, that algorithm as a service is endowed with a key property of fractal, which provides the corresponding scalability and elasticity. The article focuses on the design of elastic algorithms based on Container-component simulation model. The model has fractal property. The application of the model to design gradient ascent algorithm as a service is presented.
Influence of the angular momentum on definition of pressure
Authors: Prozorova E 
Published: September 2020

Abstract
The paper studies the impact of angular momentum in aerodynamic on the problem of flowing liquid near the surface. In a modified theory, the laws of conservation in integral form remain the same, but the divergent and rotational components are not separate. In this theory, the order of different equations is increased. The correspondence between the potential flow with velocity circulation, Newton law and Euler equations with different values of pressure on coordinate axis are discussed for potential flow. As an example of the influence of the angular momentum, the problem of fluid motion between two closely spaced parallel plates is considered.
Research of a two-phase steam system during its flow in the pipe and a device for measuring dryness steam
Authors: Kaplan B Y , Motorin A A , Stupitsky E L 
Published: September 2020

Abstract
Water steam is widely applied in various fields of industry and heat power engineering. The article shows a wide application of water steam in heat-and-power engineering. In this regard, the issue of preserving and controlling the dryness of steam during its transportation via steam lines remains relevant. Quite detailed theoretical studies of steam parameters during its flow in the pipe have been performed. A comparative analysis of steam velocity and temperature plots depending on certain flow parameters and accepted approximations is performed. The analysis presented that gas-dynamic and thermodynamic processes can be considered approximately. This does not play a fundamental role in the general patterns of dropping liquid. As a result of numerical studies of the steam condensation kinetics, the specific volume and density of drop condensate along the pipe section are determined. The obtained results and the proposed methodological approach for determining the parameters of steam were used in the development and further improvement of the device for measuring the dryness of steam, the original construction of which was proposed earlier by one of the authors. The article presents the functional diagram and layout of the measuring unit of the gauge.
Multiple antenna gyro-GNSS attitude determination system
Authors: Zharkov M V , Veremeenko K K , Kuznetsov I M , Pronkin A N 
Published: September 2020

Abstract
Attitude determination system is one of the most important system to control the moving object of any type. GNSS attitude determination systems have been actively developed in the last decade. Such systems have obvious drawbacks associated with the need for the visibility of a sufficient number of satellites. GNSS/Inertial integration is the best way to reduce satellite visibility dependence. The new concept of multiple antenna integrated inertial-satellite system design is proposed. System structure allows to exclude accelerometers from inertial measurement unit replacing it with gyro unit only. An important feature of the system is the availability of the initialization mode in motion and in conditions of limited satellite visibility. System performance was estimated in simulation and car test.
Spectral method for solving linear Caputo fractional stochastic differential equations
Authors: Rybakov K , Yushchenko A 
Published: September 2020

Abstract
We concern on the problem of finding the solution to the linear Caputo fractional stochastic differential equation with additive and multiplicative noise. It is proposed to apply the spectral method based on the spectral form of mathematical description. This method provides both an explicit form of the solution as the orthogonal series with random coefficients and a continuous-time approximation of this solution as the partial sum. Earlier, the spectral method has been applied for solving linear (non-fractional) stochastic differential equations. The proposed method is demonstrated on the modeling fractional Ornstein– Uhlenbeck process described by a linear Caputo fractional stochastic differential equation with additive noise.
Application of Walsh series to represent iterated Stratonovich stochastic integrals
Authors: Rybakov K 
Published: September 2020

Abstract
The goal of the paper is to represent iterated Stratonovich stochastic integrals using orthonormal expansions of functions by the Walsh series, to construct an algorithm for modeling iterated Stratonovich stochastic integrals, and to test this algorithm by numerical experiments. Obtained results may be used in the constructing high-order numerical methods based on the Taylor –Stratonovich expansion and the Taylor– It^o expansion. Therefore, they can be applied in a lot of problems of physics, engineering, economics and finance, when it is necessary to solve numerically stochastic differential equations.
The possibility of draining the boundary layer from the hypersonic nozzle
Authors: Ruleva L B , Solodovnikov S I 
Published: September 2020

Abstract
Hypersonic aerodynamic shock tube is used for comparison (validation) of the developed computer codes for the calculation of aerothermodynamics. Experiments in vacuum chamber of hypersonic aerodynamic shock tube showed the significant boundary layer in the nozzle. An increase in the boundary layer was observed with an increase in the length of the inner surface of the nozzle. Easy method to decrease the boundary layer of the nozzle was suggested. Areas of pressure field near hypersonic nozzle with a reduced pressure in the moment of quasi-stationary flow from the nozzle were determined experimentally.
Increasing hypersonic aerodynamic shock tube working time duration
Authors: Panasenko A V , Ruleva L B , Solodovnikov S I 
Published: September 2020

Abstract
Longer working time of the hypersonic aerodynamic shock tube has been demonstrated by applying modelling and experiment. This facility is a short-term installation. It is used to validate the results of aerothermodynamic characteristics of aircraft modelling calculated using national computational codes. Numerical modeling and experimental data results are compared. Quasi-stationary state of the gas flow in operating time of the installation requires sufficient time. A review of publications about increasing the working time of shock tubes for initiation of high-speed gas flows was made. Some models of shock tubes with longer working time have been selected for discussion. The computational studies for hypersonic aerodynamic shock tube showed a positive trend for one of the operating modes. A simulation for a regular and lengthened shock tube facilities was carried out, taking the flow as in viscous medium and using Euler equations. The effectiveness of lengthening the low pressure channel section of the facility was shown by modelling. The low pressure chamber was elongated by 3m to the existing hypersonic aerodynamic shock tube.
Heat flow measurements on high-speed aircraft models
Authors: Ruleva L B , Solodovnikov S I 
Published: September 2020

Abstract
The functionality of “Hypersonic aerodynamic shock tube” facility was expanded to obtain more complete validation of developed computer codes for the prospective high-speed aircraft aerothermodynamics description. The method of luminescent temperature converters was applied in the laboratory installation. Measuring of temperature fields on the surface of models installed in the aerodynamic unit when they have ambient air flow at Mach numbers M=5-7, have been implemented. The calorimetric type heat flow sensor was selected among existing heat flow sensors as it based on microsecond inertia, miniaturization, and relative ease of manufacturing. The sensitive elements of the calorimetric sensors were manufactured for the laboratory installation. The ability of the manufactured sensors to work and the dependence of the response time from the thickness of the heat-receiving surface were revealed.
Probable delirium is a presenting symptom of COVID-19 in frail, older adults: a cohort study of 322 hospitalised and 535 community-based older adults
Authors: Zazzara Maria Beatrice , Penfold Rose S , Roberts Amy L , Lee Karla A , Dooley Hannah , Sudre Carole H , Welch Carly , Bowyer Ruth C E , Visconti Alessia , Mangino Massimo , Freidin Maxim B , El-Sayed Moustafa Julia S , Small Kerrin S , Murray Benjamin , Modat Marc , Graham Mark S , Wolf Jonathan , Ourselin Sebastien , Martin Finbarr C , Steves Claire J , Lochlainn Mary Ni 
Published: September 2020

Abstract

Background
Frailty, increased vulnerability to physiological stressors, is associated with adverse outcomes. COVID-19 exhibits a more severe disease course in older, comorbid adults. Awareness of atypical presentations is critical to facilitate early identification.

Objective
To assess how frailty affects presenting COVID-19 symptoms in older adults.

Design
Observational cohort study of hospitalised older patients and self-report data for community-based older adults.

Setting
Admissions to St Thomas’ Hospital, London with laboratory-confirmed COVID-19. Community-based data for older adults using the COVID Symptom Study mobile application.

Subjects
Hospital cohort: patients aged 65 and over (n = 322); unscheduled hospital admission between 1 March 2020 and 5 May 2020; COVID-19 confirmed by RT-PCR of nasopharyngeal swab. Community-based cohort: participants aged 65 and over enrolled in the COVID Symptom Study (n = 535); reported test-positive for COVID-19 from 24 March (application launch) to 8 May 2020.

Methods
Multivariable logistic regression analysis performed on age-matched samples from hospital and community-based cohorts to ascertain association of frailty with symptoms of confirmed COVID-19.

Results
Hospital cohort: significantly higher prevalence of probable delirium in the frail sample, with no difference in fever or cough. Community-based cohort: significantly higher prevalence of possible delirium in frailer, older adults and fatigue and shortness of breath.

Conclusions
This is the first study demonstrating higher prevalence of probable delirium as a COVID-19 symptom in older adults with frailty compared to other older adults. This emphasises need for systematic frailty assessment and screening for delirium in acutely ill older patients in hospital and community settings. Clinicians should suspect COVID-19 in frail adults with delirium.
Composite grid designs for adaptive computer experiments with fast inference
Authors: Plumlee M , Erickson C B , Ankenman B E , Lawrence E 
Published: September 2020

Summary
Experiments are often used to produce emulators of deterministic computer code. This article introduces composite grid experimental designs and a sequential method for building the designs for accurate emulation. Computational methods are developed that enable fast and exact Gaussian process inference even with large sample sizes. We demonstrate that the proposed approach can produce emulators that are orders of magnitude more accurate than current approximations at a comparable computational cost.
Chronic stress induces significant gene expression changes in the prefrontal cortex alongside alterations in adult hippocampal neurogenesis
Authors: Musaelyan Ksenia , Yildizoglu Selin , Bozeman James , Du Preez Andrea , Egeland Martin , Zunszain Patricia A , Pariante Carmine M , Fernandes Cathy , Thuret Sandrine 
Published: September 2020

Abstract
Adult hippocampal neurogenesis is involved in stress-related disorders such as depression, posttraumatic stress disorders, as well as in the mechanism of antidepressant effects. However, the molecular mechanisms involved in these associations remain to be fully explored. In this study, unpredictable chronic mild stress in mice resulted in a deficit in neuronal dendritic tree development and neuroblast migration in the hippocampal neurogenic niche. To investigate molecular pathways underlying neurogenesis alteration, genome-wide gene expression changes were assessed in the prefrontal cortex, hippocampus and the hypothalamus alongside neurogenesis changes. Cluster analysis showed that the transcriptomic signature of chronic stress is much more prominent in the prefrontal cortex compared to the hippocampus and the hypothalamus. Pathway analyses suggested huntingtin, leptin, myelin regulatory factor, methyl-CpG binding protein and brain-derived neurotrophic factor as the top predicted upstream regulators of transcriptomic changes in the prefrontal cortex. Involvement of the satiety regulating pathways (leptin) was corroborated by behavioural data showing increased food reward motivation in stressed mice. Behavioural and gene expression data also suggested circadian rhythm disruption and activation of circadian clock genes such as Period 2. Interestingly, most of these pathways have been previously shown to be involved in the regulation of adult hippocampal neurogenesis. It is possible that activation of these pathways in the prefrontal cortex by chronic stress indirectly affects neuronal differentiation and migration in the hippocampal neurogenic niche via reciprocal connections between the two brain areas.
Variants inPPP2R2BandIGF2BP3are associated with higher tau deposition
Authors: Ramanan Vijay K , Wang Xuewei , Przybelski Scott A , Raghavan Sheelakumari , Heckman Michael G , Batzler Anthony , Kosel Matthew L , Hohman Timothy J , Knopman David S , Graff-Radford Jonathan , Lowe Val J , Mielke Michelle M , Jack Clifford R , Petersen Ronald C , Ross Owen A , Vemuri Prashanthi 
Published: September 2020

AbstractTau deposition is a key biological feature of Alzheimer’s disease that is closely related to cognitive impairment. However, it remains poorly understood why certain individuals may be more susceptible to tau deposition while others are more resistant. The recent availability of in vivo assessment of tau burden through positron emission tomography provides an opportunity to test the hypothesis that common genetic variants may influence tau deposition. We performed a genome-wide association study of tau-positron emission tomography on a sample of 754 individuals over age 50 (mean age 72.4 years, 54.6% men, 87.6% cognitively unimpaired) from the population-based Mayo Clinic Study of Aging. Linear regression was performed to test nucleotide polymorphism associations with AV-1451 (18F-flortaucipir) tau-positron emission tomography burden in an Alzheimer’s-signature composite region of interest, using an additive genetic model and covarying for age, sex and genetic principal components. Genome-wide significant associations with higher tau were identified for rs76752255 (P = 9.91 × 10−9, β = 0.20) in the tau phosphorylation regulatory gene PPP2R2B (protein phosphatase 2 regulatory subunit B) and for rs117402302 (P  = 4.00 × 10−8, β = 0.19) near IGF2BP3 (insulin-like growth factor 2 mRNA-binding protein 3). The PPP2R2B association remained genome-wide significant after additionally covarying for global amyloid burden and cerebrovascular disease risk, while the IGF2BP3 association was partially attenuated after accounting for amyloid load. In addition to these discoveries, three single nucleotide polymorphisms within MAPT (microtubule-associated protein tau) displayed nominal associations with tau-positron emission tomography burden, and the association of the APOE (apolipoprotein E) ɛ4 allele with tau-positron emission tomography was marginally nonsignificant (P  = 0.06, β = 0.07). No associations with tau-positron emission tomography burden were identified for other single nucleotide polymorphisms associated with Alzheimer’s disease clinical diagnosis in prior large case–control studies. Our findings nominate PPP2R2B and IGF2BP3 as novel potential influences on tau pathology which warrant further functional characterization. Our data are also supportive of previous literature on the associations of MAPT genetic variation with tau, and more broadly supports the inference that tau accumulation may have a genetic architecture distinct from known Alzheimer’s susceptibility genes, which may have implications for improved risk stratification and therapeutic targeting.