bluuebunny/crossref_metadata_2025 huggingface dataset:
Deformations of GR, geometrodynamics and reality conditions
Authors: Krasnov Kirill , Mitsou Ermis
Published: February 2021

In four dimensions complexified general relativity (GR) can be non-trivially deformed: there exists an (infinite-parameter) set of modifications all having the same count of degrees of freedom. It is trivial to impose reality conditions that give versions of the deformed theories corresponding to Riemannian and split metric signatures. We revisit the Lorentzian signature case. To make the problem tractable, we restrict our attention to a four-parameter set of deformations that are natural extensions of Ashtekar’s Hamiltonian formalism for GR. The Hamiltonian of the later is a linear combination of EEE and EEB. We consider theories for which the Hamiltonian constraint is a general linear combination of EEE, EEB, EBB and BBB. Our main result is the computation of the evolution equations for the modified theories as geometrodynamics evolution equations for the three-metric. We show that only for GR (and the related theory of self-dual gravity) these equations close in the sense that they can be written in terms of only the metric and its first time derivative. Modified theories are therefore seen to be essentially non-metric in the sense that their dynamics cannot be reduced to geometrodynamics. We then show this to be related to the problem with Lorentzian reality conditions: the conditions of reality of the three-metric and its time derivative are not acceptable because they are not preserved by the dynamics. Put differently, their conservation implies extra reality conditions on higher-order time derivatives, which then leaves no room for degrees of freedom.
End benches scattered light modelling and subtraction in advanced Virgo
Authors: Wąs M , Gouaty R , Bonnand R
Published: February 2021

Advanced Virgo end benches were a significant source of scattered light noise during the third observing run that lasted from April 1 2019 until March 27 2020. We describe how that noise could be subtracted using auxiliary channels during the online strain data reconstruction. We model in detail the scattered light noise coupling and demonstrate that further noise subtraction can be achieved. We also show that the fitted model parameters can be used to optically characterized the interferometer and in particular provide a novel way of establishing an absolute calibration of the detector strain data.
Oblique bounce of a double sphere on a horizontal surface
Authors: Cross Rod
Published: February 2021

The normal coefficient of restitution (COR) for a sphere that bounces obliquely or at right angles on a horizontal surface usually has an approximately constant value between 0 and 1, which are the limits for a completely inelastic or a perfectly elastic collision respectively. Different results are obtained for the bounce of a non-spherical object. Measurements are presented for a double sphere consisting of two golf balls joined together, incident obliquely on a smooth horizontal surface. The COR varied from 0.15 to 1.0 depending on the alignment of the two balls and the incident spin. The results are explained in terms of a simple bounce model where the lower ball slides on the horizontal surface, and in terms of three different values of the COR defined in terms of (a) the bounce height, (b) the vertical speed of the contact point and (c) the ratio of the final to the initial kinetic energy.
Elastic scattering and electronic excitation in positron interactions with neon
Authors: Cheong Z , Babij T J , Anthouard B , Machachek J R , McEachran R P , Sullivan J P
Published: February 2021

We report measurements of low energy positron scattering from neon, with the first measurements of absolute differential cross sections (DCSs) and of state-selective electronic excitation. These measurements are compared to calculations using the relativistic optical potential (ROP) technique, as well as other recently published theoretical calculations. At the lowest energies, experimental DCS data are fitted to extract scattering phase shifts, which can be compared to theoretical values and also used to generate DCS values over the full angular range. For the most part we find good accord in the two descriptions of the scattering processes, with some key disagreements. An analysis of possible sources of systematic error has also been presented, in light of the discrepancies.
Toward the perfect membrane material for environmental x-ray photoelectron spectroscopy
Authors: Leidinger Paul , Kraus Jürgen , Kratky Tim , Zeller Patrick , Menteş Tevfik Onur , Genuzio Francesca , Locatelli Andrea , Günther Sebastian
Published: February 2021

We outline our achievements in developing electron transparent, leak-tight membranes required for environmental photoelectron spectroscopy (PES). We discuss the mechanical constraints limiting the achievable membrane size and review the development of growth protocols for the chemical vapor deposition (CVD) of single-crystalline graphene on highly (111) textured Cu foils serving as membrane material. During CVD growth, Cu tends to develop a mesoscopic staircase morphology consisting of alternating inclined surface planes, irrespective of whether the covering graphene film or the substrate are single-crystalline. This morphology remains imprinted even when converting the film into freestanding graphene, which affects its mechanical properties. Determining the number of carbon layers in freestanding graphene, we show that membranes reported to suspend over distances larger than 20 µm most likely consist of few-layer graphene. The Raman band signature often used to confirm monolayer graphene rather relates to graphene with turbostratic stacking. The vertical corrugation of freestanding graphene was shown to be almost absent for tri- and four-layer-thick graphene but substantial for bilayer and especially for monolayer graphene. The corrugation is reduced when mechanically straining the freestanding graphene through thermal expansion of the supporting frame, especially flattening membrane areas with imprinted staircase morphology. The electron signal attenuation through supported and freestanding graphene was determined as a function of the electron kinetic energy, verifying that large-area graphene-based electron windows have sufficient electron transparency required for environmental PES. Meanwhile, we managed to cover 100 µm-sized single holes by few-layer graphene up to a coverage fraction of over 99.9998%, as deduced when applying 10 mbar air on one side of the sealing membrane without detecting any measurable pressure increase on its ultrahigh vacuum side. The reported achievements will pave the way toward the development of laboratory-based environmental PES.
Practical comparisons of EIT excitation protocols with applications in high-contrast imaging
Authors: Dang Chunhui , Bellis Cédric , Darnajou Mathieu , Ricciardi Guillaume , Mylvaganam Saba , Bourennane Salah
Published: February 2021

In the field of electrical impedance tomography (EIT), numerous studies have aimed at the optimal excitation/measurement strategies for improving conductivity distribution imaging, particularly in the applications involving highly contrasted materials. These studies focus on the conditions to be imposed on the currents fed into the electrodes and on their measurement counterparts, while making use of various quantitative optimal criteria. While most EIT systems rely on a sequential excitation at neighboring electrodes with measurements at the remaining ones, some alternative excitation strategies, or protocols, have also proven to be effective and easy to implement using modern hardware. In this context, the present study aims at confronting some of the predominant EIT excitation protocols on a practical system that is dedicated to the imaging of media with highly contrasted material components, i.e. with large variations of the conductivity field. More specifically, the so-called adjacent, opposite, full-scan and trigonometric excitation strategies are considered here and assessed on a number of criteria, which are: complexity of a practical implementation, number of independent measurements, amplitude of the measured responses, sensitivity distribution and quality of the final reconstructed images. For each of these excitation protocols, numerical simulations and static experiments with test objects placed in the EIT sensor considered are carried out using various conductivity profiles, while reconstructed images are evaluated both qualitatively and qualitatively. Our results highlight the preeminence of the full-scan and trigonometric strategies, which are characterized by high response signals and satisfying overall sensitivities. Moreover, for the studied configurations in both numerical simulations and static experiments, the full scan and trigonometric strategies lead to improved contrasts in the reconstructed images of the phases distribution.
Tuning electrical and interfacial thermal properties of bilayer MoS2 via electrochemical intercalation
Authors: Xiong Feng , Yalon Eilam , McClellan Connor J , Zhang Jinsong , Aslan Burak , Sood Aditya , Sun Jie , Andolina Christopher M , Saidi Wissam A , Goodson Kenneth E , Heinz Tony F , Cui Yi , Pop Eric
Published: February 2021

Layered two-dimensional (2D) materials such as MoS2 have attracted much attention for nano- and opto-electronics. Recently, intercalation (e.g. of ions, atoms, or molecules) has emerged as an effective technique to modulate material properties of such layered 2D films reversibly. We probe both the electrical and thermal properties of Li-intercalated bilayer MoS2 nanosheets by combining electrical measurements and Raman spectroscopy. We demonstrate reversible modulation of carrier density over more than two orders of magnitude (from 0.8 × 1012 to 1.5 × 1014 cm−2), and we simultaneously obtain the thermal boundary conductance between the bilayer and its supporting SiO2 substrate for an intercalated system for the first time. This thermal coupling can be reversibly modulated by nearly a factor of eight, from 14 ± 4.0 MW m−2 K−1 before intercalation to 1.8 ± 0.9 MW m−2 K−1 when the MoS2 is fully lithiated. These results reveal electrochemical intercalation as a reversible tool to modulate and control both electrical and thermal properties of 2D layers.
Prior-image-based CT reconstruction using attenuation-mismatched priors
Authors: Zhang Hao , Capaldi Dante , Zeng Dong , Ma Jianhua , Xing Lei
Published: February 2021

Prior-image-based reconstruction (PIBR) methods are powerful tools for reducing radiation doses and improving the image quality of low-dose computed tomography (CT). Apart from anatomical changes, prior and current images can also have different attenuations because they originated from different scanners or from the same scanner but with different x-ray beam qualities (e.g., kVp settings, beam filters) during data acquisition. In such scenarios, with attenuation-mismatched priors, PIBR is challenging. In this work, we investigate a specific PIBR method, called statistical image reconstruction, using normal-dose image-induced nonlocal means regularization (SIR-ndiNLM), to address PIBR with such attenuation-mismatched priors and achieve quantitative low-dose CT imaging. We propose two corrective schemes for the original SIR-ndiNLM method, (1) a global histogram-matching approach and (2) a local attenuation correction approach, to account for the attenuation differences between the prior and current images in PIBR. We validate the efficacy of the proposed schemes using images acquired from dual-energy CT scanners to simulate attenuation mismatches. Meanwhile, we utilize different CT slices to simulate anatomical mismatches or changes between the prior and the current low-dose image. We observe that the original SIR-ndiNLM introduces artifacts to the reconstruction when an attenuation-mismatched prior is used. Furthermore, we find that a larger attenuation mismatch between the prior and current images results in more severe artifacts in the SIR-ndiNLM reconstruction. Our two proposed corrective schemes enable SIR-ndiNLM to effectively handle the attenuation mismatch and anatomical changes between the two images and successfully eliminate the artifacts. We demonstrate that the proposed techniques permit SIR-ndiNLM to leverage the attenuation-mismatched prior and achieve quantitative low-dose CT reconstruction from both low-flux and sparse-view data acquisitions. This work permits robust and reliable PIBR for CT data acquired using different beam settings.
Influence of secondary electron emission on plasma-surface interactions in the low earth orbit environment
Authors: Nuwal Nakul , Levin Deborah A
Published: February 2021

The low earth orbit plasma experienced by exposed interconnect-dielectric junctions commonly found on spacecraft solar panel surfaces was modeled using a fully kinetic particle-in-cell (PIC) simulation of both ambient ions and electrons. From time-accurate simulations we observed that the plasma sheath had a formation time somewhere between the ion and electron time scales of 17 μs and 30 ps, respectively and electron and ion velocity distribution functions were observed to be highly non-Maxwellian. Comparison of the electron plasma sheath thickness with analytic cylindrical sheath models gave reasonable agreement if the embedded biased interconnect voltage was sufficiently high to cause the dielectric surface to act as a free electron flowing medium. Finally, it was found from the fully kinetic PIC simulations that the fundamental mechanism behind parasitic current is closely related to electron avalanche and the fraction of SEE emitted from different avalanche levels as well as the current collected at the interconnect could be modeled by a power law series for avalanche levels greater than two.
Magnetic background field-tolerant SQIF-based current sensors
Authors: Schmelz M , Hopf M , Zakosarenko V , Schönau T , Chwala A , Anders S , Kunert J , Stolz R
Published: February 2021

We report on the development of magnetic background field-tolerant superconducting quantum interference filter (SQIF) based on low-capacitance sub-micrometer sized cross-type Josephson junctions either as current sensing amplifiers—even on chip—for advanced superconducting quantum interference device (SQUID) readout circuits or as magnetic field sensor in flux transformer configuration especially for geophysical measurement systems. Their very small parasitic magnetic sensitive areas enable them to operate in the Earth magnetic field and allow for magnetically unshielded cool-down. The careful consideration of magnetic sensitive areas inside each SQUID in the SQIF in all three dimensions result in developed SQIFs with 28 SQUIDs in series exhibiting large voltage swing and transfer function of more than 2 mV and

500

V

A

−
1

, respectively. We report on the electrical parameters and field stability as well as on the noise performance of the devices under investigation. SQIFs and devices with additional on-chip flux-transformers show input referred current noise levels of

5.9

and

1.1

pA

H

z

−
1

/

2

, respectively. We furthermore demonstrate their potential as SQIF-based magnetometers using them in addition with thin-film pickup loops resulting in a white magnetic field noise of

1.6

f

T

H

z

−
1

/

2

. The implemented SQIFs are thus highly compatible with state-of-the-art single SQUID-devices offering beneficial features such as a unique working point, making them excellent suited for implementation of e.g. geophysical instruments.
Accelerating self-imaging effect based on cosh-Airy beams
Authors: Wang Jing , Jiao Ruiyun , Zhang Wenqian , Yang Zhendong , Zhan Kaiyun , Liu Bing
Published: February 2021

We have investigated theoretically and numerically the accelerating self-imaging phenomenon for a superposition of cosh-Airy beams. The results show that when the real or imaginary part of the parameter of the cosh modulation function works, the accelerating self-imaging effect of the finite energy Airy beam and the quasi accelerating self-imaging effect of Airy beam with different initial launch angle can be obtained, respectively. Moreover, the cosh parameter cannot only change the accelerating self-imaging range but also control the trajectory of accelerating self-imaging. In addition, the accelerating self-imaging effect generated by selecting a large transverse displacement is further discussed. The numerical results are in good agreement with the theoretical results.
Post-acceleration of electron bunches from laser-irradiated nanoclusters
Authors: Lucchio Laura Di , Gibbon Paul
Published: February 2021

In this paper the energy gain of attosecond electron bunches emitted during the interaction of intense, few-cycle linearly polarized lasers with nanoscale spherical clusters is determined. In this case electron bunches are emitted from the rear side of the cluster and are then further accelerated while co-propagating with the laser. A previous study has shown how this two-stage process readily occurs for clusters whose radii lie between the relativistic skin depth, δ

r
= γ
1/2
c/ω

p
, and the laser spot size σ

L
(Di Lucchio & Gibbon, Phys. Rev. STAB
18, 2015). An analytical model for focused light waves interacting with compact, overdense electron bunches in vacuum is derived heuristically from world-line equations of motion of an electron. The functional integral approach is followed under the mathematical point of view of integration with respect to a stochastic variable. The resulting picture of the laser wave crossing the electron’s trajectory leads to a finite energy gain of the electron in light–matter interaction in vacuum. The analytical theory is compared with three-dimensional PIC simulations from which trajectories of the electron bunches can be extracted. The effective increase in bunch energy is determined under realistic conditions both for the peak (mode) and the cutoff energy of the emitted bunch, in order to make quantitative comparisons with theory and the experimental findings of Cardenas et al , Nature Sci. Reports 9 (2019).
Simulation Study of on Sky Performance of a New 20W Class Macro–Micro Pulse Laser for Sodium Laser Guide Star
Authors: Li Hong-Yang , Feng Lu , Wang Jian-Li , Liu Jie , Xue Sui-Jian , Shen Zhi-Xia
Published: February 2021

As one crucial component for the latest generation of adaptive optics, tremendous efforts have been put into the development of high performance 20 W class sodium laser guide star laser system. Two such systems, the continuous wave laser by Toptica, and the quasi-continuous pulse laser by TIPC were extensively studied with simulation and field tests. A new type of 20 W class sodium laser, macro–micro pulse laser, is currently being developed by CIOMP. In this paper, we will study its on-sky performance with simulation based on Monte Carlo rate equation method. The predicted coupling efficiency for this laser in the zenith direction in Changchun is 179.73 photons s−1 W−1/(atoms m−2). The variation of coupling efficiency of this type of laser with pointing direction and the effect of D2b repumping are also studied and reported in this paper.
On sufficient statistics in quantum cryptography: quantum key distribution with mismatching detector efficiency
Authors: Balygin K A , Molotkov S N
Published: February 2021

Accounting for the different quantum efficiency of detectors is fundamentally important for ensuring the cryptographic security of practical systems of quantum cryptography. A method for accounting for different quantum efficiency of detectors is proposed. The method is, in fact, analytical and applicable to any quantum key distribution protocols.
Toward brain–heart computer interfaces: a study on the classification of upper limb movements using multisystem directional estimates
Authors: Catrambone Vincenzo , Averta Giuseppe , Bianchi Matteo , Valenza Gaetano
Published: February 2021

Objective. Brain–computer interfaces (BCIs) exploit computational features from brain signals to perform a given task. Despite recent neurophysiology and clinical findings indicating the crucial role of functional interplay between brain and cardiovascular dynamics in locomotion, heartbeat information remains to be included in common BCI systems. In this study, we exploit the multidimensional features of directional and functional interplay between electroencephalographic and heartbeat spectra to classify upper limb movements into three classes. Approach. We gathered data from 26 healthy volunteers that performed 90 movements; the data were processed using a recently proposed framework for brain–heart interplay (BHI) assessment based on synthetic physiological data generation. Extracted BHI features were employed to classify, through sequential forward selection scheme and k-nearest neighbors algorithm, among resting state and three classes of movements according to the kind of interaction with objects. Main results. The results demonstrated that the proposed brain–heart computer interface (BHCI) system could distinguish between rest and movement classes automatically with an average 90% of accuracy. Significance. Further, this study provides neurophysiology insights indicating the crucial role of functional interplay originating at the cortical level onto the heart in the upper limb neural control. The inclusion of functional BHI insights might substantially improve the neuroscientific knowledge about motor control, and this may lead to advanced BHCI systems performances.
t – norm (δ, γ) - Fuzzy Subgroup and their Properties
Authors: Arul Selvaraj X , Jayaraj J
Published: February 2021

The concept of fuzzy sets was introduced by Zadeh [2] in 1965. Rosenfield [3] introduced the notion of a fuzzy group as easily as 1971. We expand the notion of t – norm from Rajesh Kumar [1]. The author have already introduced the notation (δ,γ)-fuzzy in [4] and t – norm (δ,γ)-fuzzy [5]. In this article, we study the notion of t – norm (δ,γ)-fuzzy set and subsequently study t – norm (δ,γ)-fuzzy group ( normal subgroup ) and their related properties.
Homomorphism of t - norm (δ, γ)-Fuzzy Groups
Authors: Arul Selvaraj X , Jayaraj J
Published: February 2021

The concept of fuzzy sets was introduced by Zadeh [2] in 1965. Rosenfield [3] introduced the notion of a fuzzy group as easily as 1971. We expand the notion of t – norm from Rajesh Kumar [1]. The author have already introduced the notation (δ,γ)-fuzzy in [4] and t – norm (δ,γ)-fuzzy [5]. In this research paper, we study the notion of t – norm (δ,γ)-fuzzy set and subsequently study t – norm (δ,γ)-fuzzy subgroup and the behavior of these t – norm (δ,γ)-fuzzy subgroups (normal subgroups) under group homomorphism have been discussed.
Irregular Set Coloring of Certain Graphs
Authors: Anitha K , Saraladevy R
Published: February 2021

We determine irregular set chromatic number of comb, friendship, K-ary tree, n-sunlet, coconut tree and jelly fish graph.
QSPR Study Of Certain Graphic Theocratic Matrices and Their Energy Using Laplacian Minimum Majority Parameter
Authors: Jenitha G. , Paulraj Jayasimman I. , Kumaravel A.
Published: February 2021

In this paper we are discussing the QSPR analysis of certain theocratic graphic matrices and their corresponding energy. Our study reveals some important results that help define the useful mathematical parameter based on their power of predicting. Our analysis shows some significant findings that aid in characterizing the valuable Mathematical Parameter based on their predictive energy.
Skin Disease Prediction and Provision of Medical Advice Using Deep Learning
Authors: Hemavathi S. , Jayasakthi Velmurugan K.
Published: February 2021

Skin diseases are hazardous and often contagious, especially melanoma, eczema, and impetigo. These skin diseases can be cured if detected early. The fundamental problem with it is, only an expert dermatologist is able to detect and classify such disease. Sometimes, the doctors also fail to correctly classify the disease and hence provide inappropriate medications to the patient. Our project proposes a skin disease detection method based on Image Processing and Deep Learning Techniques. Our system is Personal Computer based so can be used even in remote areas. The patient needs to provide the image of the infected area and it is given as an input to the application. Image Processing and Deep Learning techniques process it and deliver the accurate output. The output is used to get the best medical cure for the disease with nearest hospital details. In this project, we present a comparison of two different approaches for real-time skin disease detection algorithm based on accuracy.
Mathematical Modeling of Synovial Joints with Chemical Reaction
Authors: VijayaKumar R. , Ratchagar Nirmala P.
Published: February 2021

This paper, an effort has been made to examine the impact of some distinct parameters, namely magnetic field, porous parameter, reaction rate parameter and viscoelastic parameters of an unsteady convective diffusion through a rectangular channel. The momentum equation and concentration equation of the model have been derived by utilizing the perturbation technique and generalized dispersion model incorporated with BJ slip condition. To get an insight into various parameter of the problem on the velocity and dispersion coefficient has been analysed through different graphs.
Engineering Safety Early Warning Platform Based on BIM and Internet of Things
Authors: Ying Danlei , Cheong Chew Boon , Zou Yiping
Published: February 2021

In view of the rapid development of China’s economy and the continuous expansion of construction scale, the casualties and economic losses caused by engineering accidents are becoming more and more serious. This paper studies and puts forward a project early warning platform based on BIM Technology and Internet of things technology. Through the feasibility study of BIM Technology and Internet of things technology applied in engineering projects, and various risk assessment in engineering construction, it provides a reliable scheme. Combined with the simulation, through the modeling in revlt software and the data processing and Analysis on the platform, the early warning processing is carried out It shows the practicability and reliability of this technology in engineering safety early warning.
Design of Garbage Classification System based on RFID
Authors: Zhang Ting , Li Meng , Li Lianglin , Luo Wulei
Published: February 2021

In order to solve the problem of municipal solid waste and improve the recycling rate of resources, an intelligent garbage classification system is designed. The reader can identify the electronic tag on the garbage bag, automatically judge and open the corresponding garbage bin cover, which can be recycled or non-recyclable, so as to achieve the effect of garbage classification. At the same time, through the built-in distance, temperature and humidity sensors in the dustbin, real-time monitoring of whether the garbage is full, whether there is fire, etc., and the detected information is transmitted to the background through the network, and the alarm will be given in case of abnormality. It can reduce the workload of property cleaning staff and prevent the occurrence of fire and the spread of bacteria.
Research Status of Aero-Engine Blade Fly-off
Authors: Zhang Longfei , Li Jing , Kou Ying
Published: February 2021

The research of aero engine blade out (Fan Blade Out, FBO) is an important problem that must be solved in the design stage of the reliability and safety of the whole structure. The turbofan blades are broken due to fatigue fracture or foreign object impact, and the rotor system produces large vortex under the action of huge unbalanced force, which causes the tip of the blade to collide with the casing and friction in turn. This paper analyzes the aero-engine FBO, and provides a systematic basic theory for the design, innovation and development, which has certain reference value.
Design of Seed Rope Guiding Opener Based on DEM
Authors: Liu Dan , Dong Hao , Zhang Baofeng , You Jiahan , Yu Xiaoze
Published: February 2021

Rice seed rope planting has the advantages of water saving, energy saving and it can precisely control the rate and hill space of seeds, fertilizer and herbicide or pesticide, and simplify the sowing process as well. To solve the problem of ditching and rope laying the influence of cutting edge curve of trench opener on trench resistance is studied in this paper. Three kinds of furrow opener curves are put forward: exponential, parabola and circular. The mechanical model of the seeder was established and simulation analysis of furrow opener based on discrete element method, therefore, the edge curve equation of the soil cutting and seed rope guiding device was optimized. The simulation test results show that the exponential opener has the minimum working resistance 6.71 N; and the parabola opener has a higher working resistance 7.87 N; the circle opener has the highest resistance 9.59 N. This study may provide the basis for design of the rice seed rope planter.
Research and Analysis on the Use of 5G and Big Data in Urban Electric Vehicle Public Charging Networks
Authors: Guo Feng , Wang Yawen , Deng Guoru , Liao Rongtao , Yu Zheng , Hu Shuai , Jin Bo , Zhao Jinhui , Xiao Dongling
Published: February 2021

In recent years, the electric vehicle sales market has been expanding, but the existing urban electric vehicle public charging network system is not optimistic. Most of the researches on the construction of charging facilities and charging network are still at the stage of qualitative analysis. This paper uses the method of questionnaire survey to investigate the current situation of electric vehicle public charging network system in China. Using 5g new technology and big data technology for research and analysis, from the city level, we can explore whether the establishment of electric vehicle public charging network is feasible. The big data analysis technology can not only promote the efficiency construction of charging pile network, but also improve the user experience of charging pile charging station. At the same time, it also increases the application scenarios of charging pile network, which is not only of great significance to the development of the entire electric vehicle industry, but also greatly promotes the rapid development of the city.
Experimental Evaluation of the Lubrication Performance of Milling Al7075 with Different Nano-fluids MQL
Authors: Gao Wei , Qi Qiang , Dong Lan , Lv Xiaojie , Huang Wei
Published: February 2021

The addition of nano-fluids with different nano-particles into the biodegradable vegetable oil base has an effect on the wetting contact angle of Al7075, the cutting force and the lubrication performance, and the surface morphology of the workpiece and chip. In Milling Al7075, the lubrication performance of six different nano-fluids was evaluated. In this paper, the contact angle, cutting force and SEM morphology of aircraft Al7075 were evaluated under the lubrication conditions of Al2O3, MoS2, SiO2, CNTs, SiC and Graphite. The experimental results show that the cutting force in x direction of milling under so 2 nano-fluid lubrication is obviously smaller than that under so 2 nano-fluid lubrication. The cutting force in x direction under Al2O3 nano-fluid lubrication is 109.6% larger than that under so 2 nano-fluid lubrication, the cutting force of other nano-fluids in x direction is 2%-5% higher than that of Al2O3 nano-fluids in x direction. The rolling of SO2 spherical micro-particles can reduce the wear and the cutting force, improve the surface quality. The results show that the SO2 nano-fluid has good lubrication and wear-reducing performance.
Research on Network Marketing Reform under the Background of Big Data
Authors: Qing Haohua , Deng Jianghua , Fu Die
Published: February 2021

In the era of rapid development of information, network marketing has gradually become one of the most popular marketing methods. But there are also some inevitable problems. The current network marketing is so aimless that people are bored with it and then marketing to the enterprise’s own brand, which makes the enterprise have to change the existing network marketing mode. Therefore, this paper takes big data as the background to study the innovation strategy of network marketing. This paper uses the form of questionnaire survey to investigate some consumers’ views and suggestions on online marketing in their daily life. According to the survey, big data can help marketers analyze consumer behavior preferences and market trends. In addition, this paper analyzes and introduces some problems existing in the traditional network marketing mode, and gives the network marketing strategy under the background of big data.
Research on Asphalt Pavement Diseases and Construction Quality Control under the Background of Big Data
Authors: Ye Zhihao
Published: February 2021

In the context of rapid social and economic development, the transportation industry is under increasing pressure, and the requirements of vehicles on roads are increasing. People are paying more and more attention to the quality of asphalt pavement. However, due to the threat of excessive diseases, the pavement is prone to water damage and cracks. Therefore, it is particularly important to strengthen the quality control of asphalt pavement construction and disease prevention. Based on this, this article conducts an in-depth study on asphalt pavement disease and construction quality control under the background of big data. Based on the big data mining technology, this paper realizes the research on the relationship between pavement disease problems and influencing factors such as air temperature, surface porosity and traffic load, summarizes and analyzes several problems in the construction process, and proposes common disease prevention measures. Research shows that to improve construction quality management, it is necessary to establish a construction information database based on scientific statistical methods, monitor key indicators in the construction process in real time, and control and manage the entire construction process. Once problems are found, effective measures must be taken Solve it in time to ensure that the construction can be carried out smoothly, thereby effectively improving the level of pavement construction.
The Influence of Ideological and Political Education on Employment Quality of College Students based on Association Rule Analysis
Authors: Zhang Ying
Published: February 2021

A large number of employment data of college graduates are stored in the database. It is necessary to mine a large number of unknown and useful information hidden in these employment data. This paper aims to analyze the impact of Ideological and political education on the quality of employment by using association rules. Firstly, this paper studies the calculation formula of association rules. Firstly, the concept of association rules is described. Secondly, the association rules of employment data are analyzed and designed. Secondly, the employment data of college students and the learning data of Ideological and political education of college students are mined. Finally, the employment data is analyzed and studied in detail by using software. The experimental results show that the credits of Ideological and political education are in the range of [3,4]. 38.69% of the graduates whose achievements in Ideological and political education are within the range of [3,4] belong to class II. Among the graduates whose score of Ideological and political education in 2019 is [1,2], 35.29% are not satisfied with their current situation, that is to say, their confidence in the rules is 0.3529%. It can be seen that the credit system of Ideological and political education of college students has affected the employment quality of graduates after half a year to some extent.
Factors Affecting the Management of College Students in Ideological and Political Education in the Information Age
Authors: Wang Xiaolong
Published: February 2021

Under the new era background, Colleges also put forward new challenges and new requirements for the IPE of college students. Because the ideological and political learning is the basis of learning in various disciplines, but for college students, there are many management factors that will affect the implementation of IPE. Starting from the IPE in Colleges, this paper mainly analyzes the management factors that affect the IPE in Colleges. First of all, this paper explores the current situation of IPE in Colleges, which is hopeful and challenging. Second, it explores the current situation of management in Colleges. Based on these situations, this paper puts forward the management factors that affect IPE in Colleges, which are analyzed from the perspective of social environment and students’ own factors. Finally, it can be concluded that the level of IPE in Colleges is generally lower than that in middle schools, which indicates that IPE in Colleges should be strengthened.
Spatial Aggregation Analysis and Systemic Risk Prevention of Internet Finance Based on Neural Network Model
Authors: Xie Wangsong
Published: February 2021

With the development of science and technology, the application of neural network model is more and more extensive. In order to avoid the outbreak of financial crisis, economists and policy makers around the world pay special attention to the timely warning of financial crisis. If we can make an accurate early warning of the economic crisis, the government and regulatory agencies will have more time to deal with the possible risks and avoid major interference to economic growth. Based on this, this paper studies the spatial aggregation analysis and systemic risk prevention of Internet Finance Based on neural network model. Based on BP neural network, this paper constructs a spatial econometric model by using spatial econometric analysis method, and analyzes the empirical results of financial spatial aggregation. The results show that the Moran’s I value of China’s Internet finance index in December 2019 is 0.372, P value is 0.001, Moran’s I value of Internet payment is 0.395, P value is 0.002, Moran’s I value of Internet monetary fund is 0.357, P value is 0.001, Moran’s I value of Internet investment and financing is 0.324, P value is 0.002, Moran’s I of Internet insurance is 0.313, P value is 0.001. The results show that there is spatial agglomeration in the development of Internet finance in China. In addition, this paper also studies the systemic risk of Internet finance, analyzes its causes and puts forward corresponding preventive measures.
Application of Computer Big Data in Internet Learning
Authors: Du Li , Sun Qian
Published: February 2021

In recent years, big data technology has been developed rapidly. While big data technology has been successfully applied in many industries, it has also completely changed the traditional education and teaching mode. Using big data technology for internet teaching is a mainstream trend at present, which makes up for many deficiencies in traditional teaching. As the current Internet teaching technology is still not perfect, this paper establishes the application research of computer big data in Internet learning. This paper makes an in-depth study on the current Internet learning. Through the survey, it can be seen that the popularity rate of Internet learning is very high, and the teaching effect has been affirmed in many aspects. However, because the technology is still in the initial stage of application, there are still many technical shortcomings, such as the information data security is not high, the teaching platform performance is not stable, the platform student management is not scientific and so on. For this reason, this paper gives the relevant suggestions for these deficiencies, as well as optimization and improvement measures. Moreover, through the in-depth study on the application form and application process of Internet learning, this paper believes that Internet learning is the major trend in the future teaching reform and development, and more attention should be paid to the students’ experience and the optimization and upgrading of related technologies in the process of reform and development.
Cross-Border E-commerce Marketing Development Model based on Big Data
Authors: Wang Xia , Cai Baoyu
Published: February 2021

With the popularity of cloud computing technology, the emergence of big data highlights its importance. Now big data has been used in the development mode of cross-border e-commerce platform of major Internet enterprises and has strong commercial value. However, there are still a variety of poor qualities goods and after-sales problems, which greatly limit the development of cross-border e-commerce. This paper analyzes the impact of big data technology on cross-border e-commerce marketing, formulates reasonable management strategies and environmental factors conducive to its own development, and analyzes the application of big data technology in the marketing system of a company. Drawing on the success factors of cross-border companies and applying the summarized marketing development model to local cross-border enterprises, it is found that the effect is significantly improved compared with the previous marketing mode, management mode and strategic planning, and enterprises using big data develop in a better direction.
Substation Location Selection Using GIS and Improved Matter-Element Extension Method
Authors: Chen Hong , Zhang Jianfeng , Tian Xiao , Liu Yuntian
Published: February 2021

In order to overcome the subjectivity and limitations of traditional substation site selection methods, and to achieve efficient and visualized substation site selection, this study conducted five candidate site locations to avoid the red line area in the geographic information system, then conducted a comprehensive evaluation of the site’s economics. Using the improved matter-element model, an evaluation index system for substation site selection was established covering four intermediate levels of poor geological treatment costs, vertical layout, policy compensation and special costs, and divided into five evaluation levels: excellent, good, average, and poor, Difference, and then determine each section domain and the object to be evaluated, use programming software to calculate the maximum correlation degree of the five areas to be selected for A, B, C, D, E are 0.9118, 0.8172, 0.9202, 0.9485, 0.8557. Respectively belong to the five levels of poor, general, general, poor, and general. Finally, in the GIS system, according to the economic efficiency of site selection from high to low, it corresponds to “cyan-blue, green, yellow, orange and red” in a gradual colour sequence for the five site selection areas Colouring. The results prove that this method has better early warning and auxiliary decision-making functions for substation site selection.
RETRACTED: Analyze the Development of Public English Courses education in Vocational schools Based on AI and Big Data
Authors: Feng Lijuan
Published: February 2021

Under the influence of economic globalization, more and more technical talents with good English expression ability are needed in modern society. At present, public English has become a compulsory course in vocational school. In order to train talents loved by enterprises, vocational school organize various education activities that are conducive to public English Learning under the background of national education reform. The purpose of this paper is to analyze the development of public English Courses education in Vocational schools Based on AI big data. This paper summarizes the latest research progress of big data analysis method based on AI technology. This paper analyzes the research status of machine learning in big data environment. Then this paper proposes a personalized and developmental curriculum education model. The model is based on the big data composed of classroom education, extracurricular self-study and part of daily life. Through data mining technology, the evaluation of each student in the course of learning is given. The results show that the failure rate and the average rate of the class are greatly reduced, and the good rate is increased from 30% to 66%.
Application Analysis of VR Virtual Technology in Environmental Art Design Teaching
Authors: Li Wenfang
Published: February 2021

VR technology has been widely used in various industries, and has brought huge benefits. The field also needs VR to inject more new vitality. The purpose of this paper is to analyze the application of vr virtual technology in environmental art design teaching. This paper introduces the basic concepts of panoramic video projection, then briefly analyzes the implementation principles and layout methods of mainstream projection methods. Using the knowledge and analyzing the advantages of practical teaching cases, constructions scheme of desktop virtual reality course. And the use of software for VR display. For the current art design teaching proposed new teaching methods. This paper evaluates the teaching effect of the application. The experimental results show that in the investigation, when you think that the use to create environment design situation is conducive to improving students’ enthusiasm for learning environment design, 37 students in the experimental class choose to promote, while 12 students choose to have no change, one of the students chose to be a hindrance.
Research on the Innovation of College Basketball Information Teaching Mode under the Background of Internet
Authors: Wei Wenting , Fang Wenxuan , Wei Jinrui
Published: February 2021

Currently, in most college physical education curriculum, college basketball teaching is based on students’ interests, but different students have different interests and hobbies, which leads to some students’ resistance to basketball knowledge and lack of learning interest in the actual teaching process. In recent years, the rapid development of Internet technology has made it widely used in all fields of life and work, which leads to the reform of traditional basketball teaching. On this basis, combined with the current teaching mode of colleges and universities in China, the concept of network teaching is introduced into basketball teaching. In this paper, the experimental class and the control class were established. The experimental class adopts the college basketball information teaching under the background of Internet, while the control class adopts the existing college basketball teaching mode. After the end of the semester, comparative analysis shows that the college basketball class designed in this paper can better play the enthusiasm of students and improve students’ interest in basketball class.