bluuebunny/crossref_metadata_2025_split huggingface dataset:
Axial force radiometer for primary standard laser power measurements using photon momentum
Authors: Williams Paul A , Rogers Kyle A , Hadler Joshua A , Artusio-Glimpse Alexandra B , Lehman John H 
Published: November 2020

Abstract
We have demonstrated operation of a new photon momentum radiometer for measuring laser power levels above 1 kW by use of radiation pressure. The ‘axial’ design allows the input and output laser beams to remain collinear and the force sensing can be carried out with any analytical balance having a vertical sensing direction and sufficient readability (sensitivity). The design also provides for a parasitic fast photodiode power measurement that is calibrated in situ by the slower radiation pressure-based power measurement. This permits a short-time-constant measurement limited primarily by the photodiode bandwidth, rather than the response time of the force balance. Uncertainty contributions yield a relative expanded uncertainty of 2.1% for (1–2) kW and 1.2% above 2 kW (for laboratory environmental conditions). We perform a direct comparison between this new power meter and the existing primary standard radiation pressure power meter. We find the two techniques agree with an average inequivalence of 0.12% for continuous wave (CW) optical powers from (1–10.8) kW. This disagreement is well-explained by the quadrature-summed uncertainties of the two techniques.
Naturalistic spatiotemporal modulation of epiretinal stimulation increases the response persistence of retinal ganglion cell
Authors: Chenais Naïg Aurelia Ludmilla , Airaghi Leccardi Marta Jole Ildelfonsa , Ghezzi Diego 
Published: November 2020

Abstract

Objective. Retinal stimulation in blind patients evokes the sensation of discrete points of light called phosphenes, which allows them to perform visually guided tasks, such as orientation, navigation, object recognition, object manipulation and reading. However, the clinical benefit of artificial vision in profoundly blind patients is still tenuous, as several engineering and biophysical obstacles keep it far away from natural perception. The relative preservation of the inner retinal neurons in hereditary degenerative retinal diseases, such as retinitis pigmentosa, supports artificial vision through the network-mediated stimulation of retinal ganglion cells (RGCs). However, the response of RGCs to repeated electrical stimulation rapidly declines, primarily because of the intrinsic desensitisation of their excitatory network. In patients, upon repetitive stimulation, phosphenes fade out in less than half of a second, which drastically limits the understanding of the percept. Approach. A more naturalistic stimulation strategy, based on spatiotemporal modulation of electric pulses, could overcome the desensitisation of RGCs. To investigate this hypothesis, we performed network-mediated epiretinal stimulations paired to electrophysiological recordings in retinas explanted from both male and female retinal degeneration 10 mice. Main results. The results showed that the spatial and temporal modulation of the network-mediated epiretinal stimulation prolonged the persistence of the RGC’s response from 400 ms up to 4.2 s. Significance. A time-varied, non-stationary and interrupted stimulation of the retinal network, mimicking involuntary microsaccades, might reduce the fading of the visual percept and improve the clinical efficacy of retinal implants.
Using convolutional neural networks to decode EEG-based functional brain network with different severity of acrophobia
Authors: Wang Qiaoxiu , Wang Hong , Hu Fo , Hua Chengcheng , Wang Dangxiao 
Published: November 2020

Abstract

Objective. The prevalence of acrophobia is high, especially with the rise of many high-rise buildings. In the recent few years, researchers have begun to analyze acrophobia from the neuroscience perspective, especially to improve the virtual reality exposure therapy (VRET). Electroencephalographic (EEG) is an informative neuroimaging technique, but it is rarely used for acrophobia. The purpose of this study is to evaluate the effectiveness of using EEGs to identify the degree of acrophobia objectively. Approach. EEG data were collected by virtual reality (VR) exposure experiments. We classified all subjects’ degrees of acrophobia into three categories, where their questionnaire scores and behavior data showed significant differences. Using synchronization likelihood, we computed the functional connectivity between each pair of channels and then obtained complex networks named functional brain networks (FBNs). Basic topological features and community structure features were extracted from the FBNs. Statistical results demonstrated that FBN features can be used to distinguish different groups of subjects. We trained machine learning (ML) algorithms with FBN features as inputs and trained convolutional neural networks (CNNs) with FBNs directly as inputs. Main results. It turns out that using FBN to identify the severity of acrophobia is feasible. For ML algorithms, the community structure features of some cerebral cortex regions outperform typical topological features of the whole brain, in terms of classification accuracy. The performances of CNN algorithms are better than ML algorithms. The CNN with ResNet performs the best (accuracy reached 98.46 ± 0.42%). Significance. These observations indicate that community structures of certain cerebral cortex regions could be used to identify the degree of acrophobia. The proposed CNN framework can provide objective feedback, which could help build closed-loop VRET portable systems.
Design of quasi-axisymmetric stellarators with varying-thickness permanent magnets based on Fourier and surface magnetic charges method
Authors: Xu G.S. , Lu Z.Y. , Chen D.H. , Chen L. , Zhang X.Y. , Wu X.Q. , Ye M.Y. , Wan B.N. 
Published: November 2020

Abstract
To obtain engineering-feasible designs of stellarators with permanent magnets and simplified coils, a new algorithm has been developed based on Fourier decomposition and surface magnetic charges method. The strong toroidal fields in a quasi-axisymmetric stellarator are still generated by coils. The permanent magnets are designed to compensate the normal magnetic field B

n
on the plasma surface ∂P created by the coils and plasma. The normal magnetic fields created by the permanent magnets B
pmn are calculated as the difference between the magnetic fields created by the surface magnetic charges on the inner surface ∂D and the outer surface ∂D

h
of the magnets. The Fourier coefficients of the magnet thickness function

h

θ
,
ϕ

are computed through matrix division operation based on the least square principle with dominant Fourier components selected through 2D Fourier transformation of B
pmn. The residual uncompensated B

n
is minimized through iteration to progressively optimize the thickness function. This new algorithm has been successfully applied to design the permanent magnets of an l = 2 quasi-axisymmetric stellarator with background magnetic field created by 12 identical circular planar coils for demonstrations. High accuracy has been achieved, allowing for a flux-surface-averaged residual B

n
relative to the total field

B

n

/
B

∼
1.3
×
1

0

−
5

and a maximum residual B

n
of less than 2 Gs for ∼1 T total field. This new design has some advantages in engineering implementations: all permanent magnet pieces have the same remanence B
r; only one single layer of magnets are mounted perpendicular to the winding surface; the magnets can be easily inserted into the cells of a gridded frame attached to the winding surface and fixed with springs from the back, which greatly simplifies the manufacture, assembly and maintenance of the magnets, and thus facilitates precision control and cost reduction.
Simplified selection of optimal shell in shape of translational surface
Authors: Tupikova E , Korshunova N , Bykova G 
Published: November 2020

Abstract
The translational shells are arised by moving generatrix line along directrix line. Four shells of similar overall size and rising height are modelled in the present job, each generatrix coincide with directrix, the symmetric square plane is considered. The surface types are: surface of translation of circle along circle, catenary along catenary, sinus along sinus and ellipse along ellipse. The behaviour under equally distributed load like self-weight of 4 types of shells is considered, equally distributed load case while supporting on four corner points is considered. The solution is obtained by means of finite element analysis. The ratio of bending and membrane stresses is of interest as the criterion of optimal operation under load. The equalent von Mises stresses for abstract material with characteristics of reinforced concrete are obtained to reveal the most dangerous zones and evaluate the overall stress distribution. The study is of interest in view of perspectives to introduction into practise of structure elements of such shape.
Geometry and classification of carved Monge surfaces
Authors: Gil-oulbé M , Ndomilep A J I 
Published: November 2020

Abstract
There are more and more needs of new forms in the world architecture. The thin shells theory and the surfaces theory give enough materials to scientifics and designers. This article is devoted to the geometric investigation of carved Monge surfaces. The geometry of these surfaces is inner and outer. For this, the coefficients of their fundamental forms are found and allow the classification of these surfaces. The kinetic method is used for their geometric investigation and classification. The parametric definitions of these multitude forms of carved Monge surfaces allow the 3D plotting of these surfaces by mean of the software MathCAD. The results obtained by this investigation are their vector, implicite, explicite and parametric definitions, the mathematic modelling of their inner and outer geometry, their 3D plotting and their classification. This variety of carved Monge surfaces can be used as the median surface of thin elastic shells design from them. The geometry these elastic shells, because their thin is the one of the carved Monge surfaces. The multitude of the designed thin elastic shells are expressive, durable and cover large spans. The multitude of their forms can find applications in the architecture of civil and industrial buildings and also in mechanical engineering.
Additional geometric investigation of carved Monge surfaces
Authors: Gil-oulbé M , Ndomilep A J I 
Published: November 2020

Abstract
The large number of scientific papers on carved Monge surfaces give an idea of the dynamism of the research activity on them. Based on a definition of the concerned surfaces, several investigations have been carried out and many scientific works produced. The methods used by scientists to investigate the geometry of these surfaces are those of the differential geometry. Additional investigations, by mean of the kinematic method gave as a result, an alternative definition: a carved surface is generated by the motion of some plane curve (generatrix) along another arbitrary curve (directrix) so that the generatrix curve lies in the normal plane of the directrix line and is rigidly connected with it. However, it should be noted that the latter condition is necessary, but not sufficient for the formation of a carved surface. To achieve this goal, methods of differential geometry are used. In this article, the equation of the generatrix curve in the polar coordinate system is used and the parametric equation of carved Monge surfaces is specified that allows to more study their inner and outer geometries. New equations are obtained for more kinds of carved Monge surfaces that are classified and plotted by mean of the software Mathcad. These new forms of carved Monge surfaces can be used as middle surfaces for thin elastic shells that will be expressive and cover large spans.
Numerical simulation of gas propagation process behind a shock wave during optical breakdown of air in a cylindrical channel
Authors: Sattarov A G , Ziganshin B R , Sochnev A V , Nagulin K Y , Lapshin S V 
Published: November 2020

Abstract
This paper substantiates the need to study processes during nanosecond optical breakdown inside a cylindrical channel, and gives an analogy between L. Sedov’s theory of point explosion and an optical breakdown. A variant of the evolution of a shock wave inside a cylindrical channel is proposed. Based on the solution of the problem of a point explosion with backpressure, a preliminary estimate of the gas pressure and velocity behind the shock front was obtained to set the initial conditions in Ansys Fluent. As a result of numerical simulation, the characteristics of the shock wave were calculated, and the distributions of the velocity, density and pressure of the gas behind the shock front were obtained. According to comparison of the experiments and results of numerical simulation, an estimate of the shock wave energy is given, which is from 8 to 16% of the energy of a nanosecond laser pulse. The results of the proposed method of numerical calculation are consistent with the experimental data for measuring the time of the shock wave exits from the channel and the target momentum at atmospheric pressure.
The effectiveness of symbolic integer splitting method over both synchronous stream ciphers and perfectly secret ciphers
Authors: Alhussain A H 
Published: November 2020

Abstract
Synchronous stream ciphers are classified up to the used keystream into two types: either to the synchronous ciphers that are used pseudorandom keystreams, or to the perfectly-secret ciphers that are used truly random keystreams; each of these classifications has its disadvantages, so the necessity to find a method that belongs to the synchronous stream ciphers and overcomes their disadvantages is required. In this article, the author proposes a method to satisfy this purpose; the proposed method is called symbolic integer splitting method and it is a mathematical method for representing an integer in form of a certain sequence of integers by using the modular arithmetic operation. Also this method can be classified under perfectly-secret ciphers because it satisfies asymptotic secrecy under a certain condition. The new scientific results are conducted as the ability of this method to success in dealing with the disadvantages of both the traditional synchronous stream ciphers and perfectly-secret ones, likes: insecure protection of information, hide the information about the length of original message from the cryptanalyst, no need to use each gamma only once, not expensive in terms of required resources to store gammas.
Voice signal analysis techniques for cognitive decline (stress) assessment
Authors: Loizou C P , Christodoulides P 
Published: November 2020

AbstractSpeech signals may provide important information for measuring and modelling human behaviour, especially for assessing mental health as well as estimating the emotional state of a person. Speaker’s physiological and/or physical state may be thus identified by detecting the cognitive decline (CD) or stress levels using signal analysis of voice. This preliminary study presents a survey on methods introduced for CD and stress voice detection in humans. It is shown that increase in signal’s fundamental frequency (f0) as well as its frequency formants, are the most common effects of CD and stress. Additional voice parameters could be used to identify normal from CD and normal from stressed voice as well as the cognitive state of the elderly. The present study poses the initiation of a project for the development of a mobile application for the automated voice detection and analysis on the fly, which will aid in the detection of early signs of CD and stress. Further investigation with application on a large number of voice samples is required for validating the methods.
The degree of physical depreciation of buildings and structures
Authors: Tamrazyan A G , Ubysz A , Kharun M 
Published: November 2020

Abstract
The influence of an aggressive environment affects the appearance of physico-mechanical and physico-chemical corrosion processes, which in turn affects the depreciation of concrete properties, the redistribution of internal forces in sections and the depreciation of the working conditions of the reinforcement. The article discusses issues related to the degree of influence of environmental aggressiveness on building structures. It was shown that steel corrosion in concrete occurs due to a change in its passivity, which is associated with a decrease in alkalinity to pH <12 during carbonation of concrete. Data on the average rate of destruction of the material (metal and concrete) are given in case of corrosion. Types of solutions to extend the life of buildings and structures are presented. Methods for calculating physical wear are highlighted. The physical depreciation of the building is shown graphically, considering repair work. The definition of physical depreciation of buildings based on the calculation of the physical depreciations of its individual structural elements is given. An example of calculating the physical depreciation of a building is considered. A formula has been developed for determining the degree of damage to structural elements of a building object. The results of calculations of the degree of damage and the degree of physical depreciation of structural elements of the building are presented.
Effect of fire extinguish methods on RHA-concrete strength
Authors: Elshahat M R , Abu Mahadi M I , Elroba S M , Dayoub N , Petrova L A 
Published: November 2020

Abstract
During the few past years reuse these materials to enhancement the mechanical properties of concrete are one of the aims of concrete technology. The previous researches turn the rice hulls into rice husk ash by different methods. In this research, RHA were prepared by two methods which are oven burning at 200ºC and exposure to direct flame. Concrete cubes with 4%, 8%, 12%, and 16% by weight of cement were prepared and tested under compression test to achieve the optimum percentage of replacement and RHA preparation method. Then, three groups of RHA concrete cubes were casted and exposed to direct fire for one hour. One group of them tested directly to study the enhancement of fire resistance of RHA concrete and act of RHA in concrete fire resistance while, the other groups extinguished by two different methods (Water, and Powder) to study the effect of fire extinguish method on concrete strength. The results found that oven burning rice husk produce RHA better than direct flam. Effect of fire extinguish method has nearly the same effect on the reduction in concrete compressive strength and flexural strength. Concrete fire resistance for RHA concrete is higher than the conventional concrete.
Application of Fuzzy theory in project scheduling
Authors: Dayoub N , Stashevskiy A , Elroba S M , Elshahate M R 
Published: November 2020

Abstract
Project scheduling is considered one of the most important stages of project planning, and aims to optimize the use of available resources to obtain satisfactory results within the limits of time, cost, and quality. Previously, dealing with the issue of project scheduling was considered by some parameters as fixed values (such as the duration of project activities). Subsequently, cloudy theory allowed the development of new methods with the ability to deal with engineering problems in a realistic way close to human processing, relying on the user’s knowledge and experience, and in cases of uncertain data. In this article, a research review of the use of motion blur theory to solve the project scheduling problem showed the potential ability to apply in multiple fields and its ability to integrate with other methods such as (genetic algorithm).
Construction cost control and duration analysis of rehabilitation project
Authors: Koroteev D D , Huang Jueru , Kamrunnaher Mimi 
Published: November 2020

Abstract
In the process of rapid urbanization, the green ecological project is not only an important part of the function of urban space, but also an important way to promote the implementation of ecological civilization in the industrial economy and society. In China green ecological project is mainly embodied in the form of urban landscape engineering. Due to the expansion of the size of the city and the increase of the urban population, many of the original urban landscape projects cannot be matched with the current situation. Such as the original vegetation is destroyed, the equipment becomes old, functional single and so on. Today if the re-construction of the project under the original engineering conditions is carried out, this kind of re-construction project is called the green ecological project. And the construction of the rehabilitation project is called an effective means to realize the value of green ecological projects. This paper takes the landscape and greening re-construction project of Kaifeng West Division scenic spot as the research object, through the system of construction cost control and the construction period analysis research, the case on behalf of the re-construction of the construction.
Cyber-physical predictive diagnostics system for servos of mobile construction robots
Authors: Travush V , Erofeev V , Bulgakov A , Kruglova T , Svetlov D 
Published: November 2020

Abstract
The article is devoted to solving the urgent scientific and technical problem of increasing the operational reliability of mobile construction robots. The cyber-physical system for predictive diagnostics of their servo drives is proposed. A five-level structure of a cyber-physical predictive diagnostics system is proposed. A description of each level is provided. An effective set of diagnostic parameters for predictive diagnostics of servo drives has been selected. A method is proposed to distinguish a faulty state from a load change based on wavelet transform and neural networks. A method for predicting the technical state of construction robots and electric motors based on neural networks has been developed. A fuzzy decision-making model based on the results of predictive diagnostics to optimize the trajectory of a mobile construction robot is described in detail. This allows to significantly extend the operational life of the mobile construction robot to eliminate sudden malfunctions and downtime of the construction site.
Features of structural plywood operation in conditions of flat stress state
Authors: Boytemirova I N , Boytemirov F A , Koroteev D D 
Published: November 2020

Abstract
The aim of our research work was to study operation features of plywood structures in flat stress state, which takes place in conditions of real operation of sheet structural materials. The method of study the materials in such conditions was developed. It includes determination of optimal form of specimens and equipment, providing tests of structural plywood under various ratio of values and signs of loads, made in mutually perpendicular directions. The research results of plywood operation from larch timber in conditions of biaxial tension and the assessment of its strength criterion under biaxial tension are shown in the research paper. The values of destructive stresses under various ratio of tension stress, directed along the main axes of elastic anisotropy of the tested material, were obtained. The experimental research results testify to possibility of using the test results of plywood specimens in conditions of biaxial tension and show that addition of extra stress almost does not reduce the strength limit of structural plywood.