bluuebunny/crossref_metadata_2025 huggingface dataset:
Transverse mode locking of the Stokes component of a diode end-pumped Q-switched Nd : KGW laser
Authors: Koromyslov A.L. , Tupitsyn I.M. , Cheshev E.A. , Chulkov R.V.
Published: June 2021

Lasing in a solid-state inhomogeneously diode end-pumped Nd : KGW/Cr4+ : YAG laser is obtained at wavelengths of 1067 and 1181 nm (Stokes shift 901 cm−1) under conditions of frequency degeneracy of cavity modes. In this case, the radiation has a characteristic ring spatial structure, which testifies to transverse mode locking of the fundamental and Stokes components. The possibility of controlling the Raman conversion efficiency by changing the position of an undoped KGW crystal additionally installed in the cavity is demonstrated. It is shown that the transverse mode locking is accompanied by the total longitudinal mode locking at λ = 1067 and 1181 nm.
Suppression of nonlinear distortion in a high-speed multichannel communication line with variable quadratic dispersion compensation
Authors: Shapiro E.G. , Shapiro D.A.
Published: June 2021

We report a numerical simulation of the propagation of short (25 ps) 8QAM pulses for two polarisations in a nine-channel communication line with a frequency band of 80 GHz. It is shown that the use of large-chirp pulses and different dispersion compensators leads to effective suppression of nonlinear distortions and significantly improves the signal quality in a multichannel communication line due to the rapid pulse broadening.
Two-photon absorption of light beams of variable cross section
Authors: Gordeev A.A. , Efimkov V.F. , Zubarev I.G.
Published: June 2021

An equation is obtained to describe two-photon absorption of light beams of variable cross section. It is shown that the experimental values of the two-photon absorption coefficients of focused laser beams, calculated in the plane-wave approximation in the focal waist region and taking into account the variable cross section of the light beam, differ by two orders of magnitude.
Possibility of resonant three-photon isotope-selective excitation of vibrational states with υ = 3 of the UF6molecule mode ν3by radiation from two pulsed IR lasers in a gas-dynamically cooled molecular flow
Authors: Makarov G.N.
Published: June 2021

We consider the possibility of resonant isotope-selective population of states withυ= 3 of the vibrational modeν3of UF6molecules as a result of three-photon bichromatic excitation of the molecules by IR radiation from two pulsed CF4lasers and two pulsed para-H2lasers. We propose specific schemes and analyse the possibility of exciting the238UF6and235UF6molecules into states withυ= 3 of the vibrational modeν3using two CF4lasers (or para-H2lasers) generating in the region of 16 μm at frequencies that are significantly (by ∼3.5 – 17 cm−1) detuned from the linear absorption bands at the frequencies ofν3vibration of these molecules in a gas-dynamically cooled molecular flow. However, the sum of the doubled lasing frequency 2νL1of the first laser and the frequencyνL2of the second laser is equal to a frequency of the transitionυ= 0 →υ= 3 of the vibrational modeν3of the UF6molecules. When both laser pulses coincide in time, the possibility of selective excitation of UF6molecules from the ground vibrational state withυ= 0 to the state withυ= 3 of the vibrational modeν3is realised. The proposed schemes for the excitation of UF6molecules to states withυ= 3 are compared with the previously implemented schemes for the effective excitation of states withυ= 3 of the vibrational modeν3(F1) and states withυ= 2 of the vibrational modeν3(A1) of SF6molecules by three- and two-frequency radiation of pulsed CO2lasers, respectively.
Q-switched lasing in ZrO2 – Y2O3 – Ho2O3 crystals
Authors: Artemov S.A. , Artemov E.A. , Lomonova E.E. , Ryabochkina P.A. , Chabushkin A.N.
Published: June 2021

The energy and time characteristics of Q-switched two-micron lasing at the 5I7 → 5I8 transition of Ho3+ ions in ZrO2 – Y2O3 – Ho2O3 crystals are studied under resonance pumping to the 5I7 level by a cw Tm : LiYF4 laser. The mechanisms of appearance of burns on the faces of the ZrO2 – Y2O3 – Ho2O3 active elements at high laser energy densities are proposed.
Effect of elastic anisotropy on thermally induced distortions of a laser beam in single cubic syngony crystals with radial cooling. Part III
Authors: Vyatkin A.G.
Published: June 2021

We report a study of thermally induced depolarisation of a laser beam in single cubic syngony crystals of 23 and m3 symmetry groups with an anisotropic elastic stiffness tensor. For active elements in the form of a long rod and a thin disk with radial cooling under uniform volume pumping, we investigate the effect of anisotropy of elastic properties on the dependence of the degree of depolarisation in the crystal on the orientation of the crystallographic axes, as well as on the position of the critical orientation in the crystallographic coordinate system.
Chiral Coordination Polymers of Mandelate and its Derivatives: Tuning Crystal Packing by Modulation of Hydrogen Bonding
Authors: Tay Hui Min , Hua Carol
Published: June 2021

Chiral coordination polymers constructed from mandelic acid have shown promise in enantioselective recognition and sensing, whereas its methoxy-protected derivative, α-methoxyphenyl acetic acid, is rarely used as a ligand in coordination polymers. In this study, mandelic acid, 3,5-difluoromandelic acid, and α-methoxyphenyl acetic acid were combined with divalent transition metals and bridging dipyridyl co-ligands to obtain a series of six 1D coordination polymers. The coordination polymers of mandelate and 3,5-difluoromandelate possessed densely packed structures stabilised by hydrogen bonding. In contrast, the use of (R)-α-methoxyphenyl acetic acid gave rise to zig-zag chains with significant solvent-accessible void space.
Experimental study on artificial lightning ignition phenomenon and model of the fuel bed
Authors: Feng Junwei , Shen Hao , Liang Dong
Published: June 2021

As global warming continues, wildland lightning fires have exhibited an increasing trend. The phenomenon of lightning ignition and a model are urgent research fields. In this study, an impulse current generator was used to study artificial lightning ignition. Ignition phenomena for several fuel beds were compared. Flames in the grass bed existed in the form of particles, but these particle flames had a short duration and were extinguished by the shock waves from the artificial lightning. It is noteworthy that a 10/350 μs impulse current could ignite a cotton fibre bed and produce sustained and stable combustion. An artificial lightning ignition model for the fuel bed was established. The model was verified by artificial lightning ignition experiments. The results show that the model could be applied to grass and needle fuel beds and waveforms of 10/350 μs impulse current and short continuing current. The findings of this study provide valuable information for understanding the mechanism of lightning ignition.
Hidden or subclinical cochleopathy in idiopathic subjective tinnitus
Authors: Morgan Ashraf Elsayed , Elghandour Amira Mohammed Ahmed , Abdeltawwab Mohamed Mustafa
Published: June 2021

Introduction

Tinnitus patients with apparently normal hearing represent a challenge to models of tinnitus generation which rely on compromised cochlear function. Although it is known that any cochlear changes even subclinical can cause tinnitus, our rational was to apply an objective measure that can aids in the quantification of these cochlear changes.

Objective

The of study was designed to evaluate possible hidden or subclinical cochlear dysfunction in idiopathic subjective tinnitus patients with normal hearing using extended high frequency audiometry and otoacoustic emissions.

Methods

Forty seven subjects enrolled in this study divided into control group (20 normal hearing adults without tinnitus) and a study group (27 normal hearing adult patients complaining of tinnitus). Extended high frequency (EHF) audiometry and otoacoustic emissions (OAEs) in addition to tinnitus matching study were done for all subjects. Study group further subdivided according to tinnitus pitch matching into low- and high-pitched tinnitus groups.

Results

The data of this study showed that patients with normal hearing sensitivity in the conventional frequency range (up to 8 kHz) and reporting tinnitus, present alterations of the auditory system in the affected side. This affection manifested as elevated EHF audiometry thresholds at 9000, 10,000, 11,200, 14,000 and 16,000 Hz. Most tinnitus patients had pitch matching frequency at high frequency range between (3000 and 8000 Hz). Transient evoked OAEs and distortion product OAEs amplitude was lower in tinnitus patients relative to controls.

Conclusion

The ultrahigh frequency hearing loss is not hidden – but – exists and awaits identification with appropriate testing.
Changes in Mechanical and Microstructural Characteristics of Demineralized Tooth Enamel after Conventional and Modified Infiltration Techniques
Authors: Gileva O S , Levitskaya A D , Mudrova O A , Daurova F Y , Zuev A L
Published: June 2021

The research carried out a comparative assessment of the physical and mechanical properties of tooth enamel: healthy; demineralized; demineralized and subsequently infiltrated with a flowable composite according to a standard or modified technique. An original in vitro model of artificial caries of human tooth enamel was used for the study, the clinical-topographic, color-textural and physical-mechanical properties of which correspond to the characteristics of enamel caries in vivo. Comparative analysis of the results of kinetic microindentation of enamel samples allows to characterize the biomaterial from the standpoint of physical materials science, to determine the advantages and disadvantages of different regimens of resin infiltration. The advantages of the modified infiltration technique are illustrated by significantly greater, as compare with classic method, increase in microhardness and elasticity against background of a decrease in a creep index of the infiltrated enamel in itsdeep zones. The results reflect the fact of incomplete obturation of microporous in the deep layers of enamel after classical treatment.
Inclinometer-Based Long-Term Monitoring of the Headframe of Salt Mine Shaft
Authors: Glot I , Shardakov I , Shestakov A , Tsvetkov R , Gusev G
Published: June 2021

The paper presents a block diagram of an automated inclinometer-based system for monitoring the inclination of a high-rise metal structure of the shaft headframe. The stress-strain state of this structure is defined by the loads associated with the operation of shaft skip and the impact of the environmental factors on the structure. The data obtained by 6 inclinometers located at different height were used to determine the inclination of the headframe and distortion of its shape. Analysis of long-term observation data revealed the existence of deformation processes having different time scales (long-term, seasonal and daily). A correlation between changes in the tilt angle of the structure and ambient temperature was established. Long-term monitoring of tilt angle showed that the displacements of the structure were within the permissible limiting values. The developed monitoring system is of great theoretical importance for understanding the deformation processes arising during the operation of such structures.
Influence of the Properties of the Plate Surface on the Natural Oscillations of the Clamped Drop
Authors: Kashina M A , Alabuzhev A A
Published: June 2021

We consider free oscillations of a clamped liquid drop. An incompressible fluid of different density surrounds the drop. In equilibrium, the drop has the form of a circular cylinder bounded axially by the parallel solid planes, the contact angle is right. These plates have different surface (wetting etc.) properties. The solution is represented as a Fourier series in eigenfunctions of the Laplace operator. The resulting system of complex equations for unknown amplitudes was solved numerically. The fundamental frequency of free oscillations can vanish in a certain interval of values of the Hocking parameter. The length of this interval depends on the ratio of the drop dimensions. Frequencies of other drop eigenmodes decrease monotonically with increasing Hocking parameter.
Experiment on Injection of SIC and BN Nanoparticles into Liquid Aluminum Using MHD Stirring with Subsequent Crystallization of the Melt
Authors: Khripchenko S , Dolgikh V , Kiselkov D
Published: June 2021

The paper describes the technique and results of experiments on the introduction of SiC and BN nanoparticles into an aluminum melt contained in a cylindrical crucible with a water-cooled bottom and heated walls. The crucible was placed in an MHD stirrer, which generated a travelling and rotating magnetic fields ensuring in such a way bidirectional stirring of the liquid metal in the crucible. After introducing the reinforcing particles, aluminum was stirred and directionally crystallized. Reinforcing particles were introduced into molten aluminum as a component of pressed pellets. Pellets with diameter of 20 mm and thickness of 15 mm were made from a mixture of aluminum powder (100-156 µm) and reinforcing nanoparticles (100-200 nm) by pressing in a special pellet die. The concentration of reinforcing particles in the pellets was selected using preliminary experiments and was 5% of their total weight. In some experiments, the aluminum was reinforced with SiC nanoparticles introduced into the melt in the amount of 0.59%, 1.04%, 1.77%, while in other experiments the concentration of hexagonal BN nanoparticles introduced into aluminum was 7%, 1%, 1.8% of the ingot weight. As the experiment showed, the reinforcing particles formulated into tablets can be introduced into aluminum by means of MHD stirring. The dependence of the ultimate strength and electrical resistance of aluminum on the concentration of the reinforcing nanoparticles introduced into it has been obtained experimentally. It has been found that with an increase in the concentration of nanoparticles in aluminum, its ultimate strength and specific electrical resistance increase. The dependences of the ultimate strength and electrical resistance of aluminum on the concentration of SiC and BN nanoparticles are very similar and close to linear (in the investigated range of concentrations of introduced particles. With an increase in the concentration of introduced nanoparticles the mechanical strength of the resulting material grows faster than the electrical resistivity. In the experiments, the ultimate strength of the samples increased by 22%, while the electrical resistance increased by 5-6%. This opens up new possibilities for industrial applications of such materials, for example, in manufacture of self-supporting wires in power lines.
Strain Measurement and Defect Detection with Fiber-Optic Sensors Embedded into the Cement Sample
Authors: Kosheleva N , Serovaev G , Gusev G
Published: June 2021

The application of embedded into material fiber-optic sensors based on Bragg gratings for strain measurement on the example of a cement sample during the manufacturing stage, under operational loads and upon the appearance and development of a defect is studied in the paper. The integrity and performance of fiber-optic sensors at all stages of the study, as well as the efficiency of strain measurement, have been demonstrated. An approach is implemented to register the appearance and development of defects based on information received from embedded fiber-optic sensors. The approach considered in the study is based on the location of sensors in the vicinity of the expected damage. The results obtained indicate the possibility of using embedded fiber-optic sensors to assess the mechanical state of civil structures.
Studying the Kaiser Effect During Modeling of Rock Loading Conditions Using the NX-borehole Jack
Authors: Beltyukov N L
Published: June 2021

The paper deals with modeling the stress state experienced by rocks in a loaded around-borehole volume to justify a promising method of in-situ stress measurements based on the Kaiser effect. Mathematical modeling of loading the horizontal borehole walls with a NX-borehole jack in a direction of principal components σ1
or σ3
of the natural stress field was performed for conditions of the unperturbed salt rock mass of the Verkhnekamskoe potassium salt deposit. As a result of the numerical calculation of stresses, it was determined that recovery of radial component σr
in compression regions of the rock volume around the borehole occurs when the jack’s pressure reaches the initial value of the principal stress. At the same time, the concentration of tangential component σθ
in these regions is retained. The rock salt specimens were tested under modes similar to the stress states of the rocks in the around-borehole volume to study the Kaiser effect under these conditions using a triaxial compression vessel. It was found that in the second loading cycle, the recovery of the initial values of axial component σaxial
of the specimen stress field, unloaded after the first cycle, stimulates acoustic emission. This regularity is true for the case when there is no increase in confining pressure σconf
on the specimen between the cycles. In the conditions with an increase in confining pressure σconf
between the first and second cycles, the Kaiser effect is found at higher values of σaxial
component than the initial ones. It is shown that the nature of the effect depends on a type of a specimen’s initial stress state and is caused by the growth resumption of longitudinal microcracks, if σaxial
> σconf
in the first loading cycle, or by a closure of lateral microcracks when σaxial
< σconf
in the first loading cycle.
Preparation of the Composite Powder Al – B4C by Ball Milling for Cold Spray
Authors: Chesnokov A E , Smirnov A V , Klinkov S V , Kosarev V F
Published: June 2021

In the work, when ball milling of mixture of aluminum powder (ASD – 1) and boron carbide (F 500) powder in a high-energy planetary mill, composite particles sized from 10 to 100 microns were produced, in the volume of which ultrafine boron carbide particles were distributed in the size range from 0.1 to 20 microns. It is assumed that the use of such particles in the production of coatings by cold gas-dynamic spraying will increase the deposition efficiency and the weight fraction of boron carbide in the coating. An increase in the concentration of carbide particles in the processed powder mixture, under all other conditions being equal, leads to a decrease in the average volume size of the particles. It is noted that in this case, the boron carbide particles behave as a surfactant. The X-ray phase analysis has shown diffraction peaks corresponding only to aluminum and boron carbide, therefore, under the selected milling conditions, the phase composition remain the same as in the original powders.
Stability Analysis of Composite Cylindrical Shell Containing Rotating Fluid
Authors: Bochkarev S A , Lekomtsev S V
Published: June 2021

A semi-analytical finite element method is used to analyze the stability of composite cylindrical shells interacting with a rotating fluid inside them. A mathematical formulation of the problem of deformable structure dynamics is based on the variational principle of virtual displacements and classical shell theory. The behavior of an ideal compressible fluid is described within the framework of the potential theory. The validity of the obtained results is supported by comparing them with the known solutions. Numerical experiments were performed for two- and three-layer cross-ply shells made of boron-epoxy resin with different boundary conditions and geometrical dimensions. It is demonstrated that, for the examined configurations, an increase in the fibre angles leads to a significant increase in the critical rotation velocities of the fluid, regardless of the conditions for fixing the edges of a thin-walled structure.
Experimental Study of Polyurea Protective Coating Effectiveness for Layered Composite Material Reinforced by Glass-Fiber under Impact Loading
Authors: Sazhenkov N A , Voronov L V , Sh Nikhamkin M
Published: June 2021

One of the promising methods for increasing the resistance of polymer composite materials to high-speed impact is the use of protective shockproof coatings. At the same time, over the past two decades, polyurea have been gaining noticeable popularity among such coatings. This work is devoted to study the effect of polyurea coating of 1.2 mm thickness on ballistic resistance characteristics of glass-fibre reinforced layered polymer of 8.5 mm thickness. During the experiments thirteen composite targets was affected by high-speed impact loading in the range of 80…150 m/s by spherical steel projectile of 23.8 mm diameter. It was shown that using the polyurea coating can increase the ballistic limit by 19% increasing the mass of the target only by 7%. Dynamic strain and displacement fields on the back surface of the target was obtained using digital image correlation method for 81.2 m/s collision process.
On the Possibility of Describing the Microstructure of Human Dentin as Soft Matrix Filled by Solid Particles
Authors: Cheboksartseva M A , Zaytsev D , Ivashov A S , Mandra J V , Zholudev S
Published: June 2021

Experimental verification of the applicability of self-similar hierarchical mechanics model for calculation of the mechanical properties of human dentin was carried out. A comparison of the deformation behavior of human dentin with the several polymer based dental composites under compression and bending was performed. It was shown that the deformation behavior of some highly filled composites was close to human dentin in the elastic regime whereas they cannot be deformed plastically under compression. Low filled composites possess higher plasticity, but a lower Young’s modulus than dentin under compression. Mechanical properties of a highly filled composite (∼60%, by volume) with smaller size of fillers are closer to the properties of human dentin under bending whereas other tested dental materials have a lower Young’s modulus and flexural strength in comparison with dentin. Therefore, we concluded that it was impossible to achieve complete combination of the mechanical properties of human dentin such as high elasticity and plasticity at high strength by means of varying the amount and size of solid filler in polymer matrix. Self-similar hierarchical mechanics model can be used for describing of the deformation behavior of human dentin in elastic regime and one level is sufficient for these calculations.
Assessment of Residual Stresses in a T-joint Weld by Combined Experimental/Theoretical Approach
Authors: Tagiltsev I I , Shutov A V
Published: June 2021

Residual stresses are common in metal structures, essentially influencing their mechanical behaviour. We consider a combined experimental/theoretical approach to residual stresses. The theoretical basis of analysis is provided by the recently developed F0-approach, operating with explicit relation between load-free and stress-free configurations. The titanium alloy Ti-6Al-4V is modelled with the multiplicative decomposition of the deformation gradient into the elastic and the plastic parts. Isotropic hyperelastic relations between stresses and elastic strains are assumed. The weak invariance of the material model allows for incorporation of residual stresses without additional numerical costs. In order to demonstrate the new experimental/theoretical approach to residual stresses, experimentally measured stresses are extrapolated from the surface inside the welded T-joint. The robustness of the stress extrapolation procedure is confirmed on synthetic experimental data.
Experimental Study of Thermal Convection in a Cylindrical Layer with a Longitudinal Partition at Modulated Rotation
Authors: Vjatkin A A , Kozlov V G , Sabirov R R
Published: June 2021

Thermal convection of a liquid in a simply connected horizontal cylindrical layer rotating at a variable velocity is investigated experimentally. The inner boundary of the layer has a higher temperature. The cavity rotates rapidly and the liquid is stably stratified in a centrifugal force field. The parameters of the experiment correspond to the conditions when inertial waves are not excited (the modulation frequency is more than twice the cavity rotation frequency). The excitation thresholds of thermal convection and the structure of convective flows are studied depending on the rotation velocity and the parameters of the rotational vibrations of the cavity. It is found that the thermal convection is excited in a threshold way and its excitation is not associated with the manifestation of the mechanism of pendulum vibrational convection. A system of toroidal rolls with a spatial period commensurate with the layer thickness is observed in the cavity.
Carbon Coating on Surface of PVC Blood Bags
Authors: Chudinov V S , Shardakov I N
Published: June 2021

In this work, we studied the effect of a carbon coating created on the surface of a polyvinyl chloride blood storage bags on protein adsorption, cell culture proliferation, and on whole blood leukocytes. Based on the results obtained, it can be assumed that the preservation of leukocytes is more effective in the blood storage bags treated by the ion-plasma method, in comparison with the untreated one. The adhesion of blood cells occurs on the carbon coating of the plasma-treated surface of the blood storage bags. This can be eliminated by preliminary application of proteins that prevent cell adhesion on the walls of the blood storage bags.
Dispersion of Elastic Waves Propagating in a Fluid-Saturated Porous Medium with Cavities
Authors: Erofeev V I , Leonteva A V
Published: June 2021

The propagation of plane longitudinal waves in a fluid-saturated porous medium with cavities is considered in linear elastic approximation. It has been shown that as distinct from the classical porous medium (Biot’s medium) where two longitudinal dispersionless waves can propagate (a fast wave and a slow wave), in the porous-cavity media three dispersive longitudinal waves propagate and one of them is solely induced due to cavities in the material. The study of waves is carried out by obtaining and analyzing the dispersion equation, phase velocity and group velocity. The frequency spectrum density is considered, which enables to identify the degree of dispersion expressiveness. At certain values of the system parameters some regions of strong and weak dispersion, regions of normal and anomalous dispersion have been identified.
Graph Classification Method Based on Wasserstein Distance
Authors: Wu Wei , Hu Guangmin , Yu Fucai
Published: June 2021

Graph classification is a challenging problem, which attracts more and more attention. The key to solving this problem is based on what metric to compare graphs, that is, how to define graph similarity. Common graph classification methods include graph kernel, graph editing distance, graph embedding and so on. We introduce a new graph similarity metric, namely GRD (Geometric gRaph Distance). Our model GRD is composed of three sub-modules, which capture the differences between the graph structures from different aspects. Finally, the graph distances defined by the three modules are fused to define the similarity between graphs. Experiments show that GRD is superior to the baseline methods on the benckmark datasets.
Fake Speech Answer-Sheet Detection on Intelligent Learning App Based on Block-Based Deep Neural Network
Authors: Wu Qingzhu , Guo Haitao , Xiong Shaowei
Published: June 2021

In order to detect the fake speech answer-sheet obtained by text-to-speech or voice conversion algorithms on intelligent English learning app, this paper proposed the idea of block-based deep neural network (BDNN), which is constructed to extract deep features. It is composed of classification-based blocks. In BDNNs, the deep feature extracted by a preceding block serves as the input to its following block. Different from the commonly used inputs for deep features extraction, the magnitude-phase spectrum, including magnitude and phase information, is exploited to feed BDNNs in order to extract effective deep features. The experimental results show that the proposed method can detect most of fake speech answer-sheet on intelligent English learning app.
A Zero-Watermark Hybrid Algorithm for Remote Sensing Images Based on DCT and DFT
Authors: Xing SiMing , Li Tong Yi , Liang Jing
Published: June 2021

Remote sensing image has significant advantages such as large detection range and fast acquisition speed, so it has been used in military, environmental, meteorological and other fields. In order to improve the robustness of the digital watermarking technology on the premise that the remote sensing image information is not modified, a remote sensing image zero watermarking algorithm based on Discrete Cosine Transform (DCT) and Discrete Fourier Transform (DFT) is proposed in this paper. First of all, the color remote sensing image is converted into grayscale image. The transformed coefficient matrix is obtained by DFT, to the grayed host image. Secondly, in order to compress the amount of information and improve the efficiency of the algorithm, the high frequency coefficient image is transformed by DCT transform. The low frequency coefficient image which is consistent with the size of the watermark image after DCT is selected as the feature image of the host image. After that, the watermark information is scrambled by Arnold transform to improve the security of the watermark information. Finally, the zero-watermark image is obtained by XOR operation between the scrambled watermark information and the feature image. The zero-watermark image is saved in a third-party database for copyright verification. In order to verify the robustness of digital watermarking, this paper carries out sharpening, histogram equalization, Karma transform, noise, filtering and geometric attacks on the host image, and compares it with other algorithms. The NC value between the extracted watermark image and the original watermark image after attacking the host image show that the algorithm has a strong ability to resist common attacks.
Research on The Method of Grass Mouse Hole Target Detection Based on Deep Learning
Authors: Wan Jiaoxia , Jian Dongfang , Yu Dongzhao
Published: June 2021

Due to climate warming, increasing soil erosion and overloading of grassland grazing, grasslands around Taipusi Banner in Inner Mongolia have been degraded to varying degrees, causing widespread rodent damage. Aiming at the problem of rodent damage in the grassland surrounding Taipusi Banner, the UAV visible light image is the main research object, and the precise detection of grass mouse holes is the research goal. Computer vision technology is used to study grass mouse hole detection methods, in order to achieve rapid and accurate mouse detection. Hole function.
Comparison of Several Machine Learning Algorithms for Prediction
Authors: Song Yi
Published: June 2021

Currently, the analysis of bacterial drug resistance is a research hotspot in the biomedical field. However, due to the long culture experiment cycle for traditional multi-antibiotics, the tolerance degree of a specific bacterium to a specific antibiotic cannot be quickly analyzed and accurately determined. Therefore, how to analyze and predict drug resistance is still a problem to be solved. With the development of whole genome sequencing (WGS) technology, this paper proposed a variety of machine learning methods to analyze and predict the drug resistance of Staphylococcus aureus and Neisseria gonorrhoeae. First of all, the original data was preprocessed; secondly, the key features, such as information entropy and Gini index, were extracted; finally, the drug resistance of each drug was analyzed and predicted. Experimental results showed that the training of this model could achieve rapid convergence, and the recognition accuracy was as high as 97%. By comparing the experimental results of various machine learning methods, it can effectively predict bacterial drug resistance.
Three-dimensional Modeling and Performance Analysis of Permanent Magnet Synchronous Motor
Authors: Song Haixia , Song Mengmeng , Zhou Jianxin
Published: June 2021

The three-dimensional model of rare earth permanent magnet synchronous motor is built based on SolidWorks software, the assembly of synchronous motor and the production of explosion diagram are completed. Finally, the motor shaft model is imported into the Workbench interface ANSYS the finite element analysis software for harmonic response and modal analysis. The results show that the motor shaft model resonates under the action of 659.38hz exciting force, the displacement value of deformation is the largest in the middle of the shaft, the maximum stress appears near the keyway of the shaft end; The first four natural frequencies and modes from modal analysis. This research provides some reference value for improving the performance of synchronous motor.
Study on Test and Evaluation of Engine Mounting System Based on Transmission Force
Authors: Wang Kaiyan , Wang Lingxi , Dong Liang
Published: June 2021

The vibration isolation performance of the engine mounting system can be evaluated by the transmission force. The transmission force characteristics of engine mounting system are analyzed by simulation and test. The 6-DOF model of engine mounting system is established by ADAMS software. The results of modal parameters and transmission force of engine mounting system are obtained by simulation. The force sensor is made with resistance strain gauge. The sensor is calibrated by chassis dynamometer method. The transmission force of the engine mounting system is tested under the complete vehicle condition. The test results of transmission force and acceleration transmissibility are compared. It is proved that the transmission force is more suitable to evaluate the vibration isolation performance of the mounting system when the vehicle is running at medium and high speed.
Planning of Vehicle Routing with Mixed Time Windows Based on the Improved Genetic Algorithm (IGA)
Authors: Jiang Yueyang
Published: June 2021

In recent years, the rapid expansion of urban distribution business and the increase use of traditional fuel logistics trucks have resulted in a lot of environmental, traffic and resource problems. “Green logistics” has become the direction of urban distribution transformation, and replacing fuel vehicles with pure electric logistics vehicles has become a way to meet the requirements of urban end distribution. In this paper, the characteristics of electric logistics vehicles are combined with the constraints of cargo capacity to meet the demand for sufficient power and driving range in the distribution process. Charging operations are carried out using charging piles at fixed locations when necessary, and the time windows of customers at each node are considered and penalty factors are set so that the distribution path of electric logistics vehicles can be well planned, which makes the total logistics cost lowest.
Research on the Application and Influence of Artificial Intelligence Technology
Authors: Chen Yuzhuo , Chen Yuchao
Published: June 2021

At present, with the steady progress of industrialization and information technology in China, lots of high-tech, including artificial intelligence, such as financial robot and face recognition system, are gradually coming into the public view. This paper points out the constituent elements and design logic of artificial intelligence, starting from the background of the development and application of related technologies. Meanwhile, based on this artificial logic, assisted by voice recognition, image recognition, data analysis and other processes, it is applied to neural network construction, data mining, intelligent information system and other fields. Finally, taking one of the fields as an example, this article deeply analyzes the possible effect and impact of the application of these technologies, which provides a theoretical basis for the large-scale promotion of artificial intelligence technology.
Research on the Statistical Model System of Each Balanced Game Based on Big Data
Authors: Yan Li
Published: June 2021

The article uses the holistic, comprehensive and dynamic diversified and complex thinking mode of big data system theory. The article creates a generalized linear model for the value of each technical and tactical performance index and the game result in each score-balanced game. To define the linear relationship between the technical and tactical performance indicators of the game and the probability of winning the game; finally, adopt the data series inference method to define the significance of the linear relationship between each technical and tactical performance indicator and the probability of winning the game. The research found that the information provided by the model created in the paper can be used in football practice such as game performance evaluation, opponent information detection, selection and modification of training preparation plans.
Research on Information Fusion Technology of MEMS Gyro Array
Authors: Xue Chao , Zhang Yinqiang , Li Lijuan , Yang Shipin
Published: June 2021

The measurement accuracy of MEMS gyroscope is relatively low. Starting from the software level, the multi-sensor information fusion technology of MEMS gyroscope array (MGA) is used to reduce the drift of MEMS gyroscope. Firstly, a signal acquisition and processing system for communicating with ADXRS810 gyroscope based on field-programmable gate array (FPGA) is designed. Secondly, the collected drift data of the gyroscope array is preprocessed. long-term drift trend terms are obtained by ensemble empirical mode decomposition (EEMD) and the linear function fitting, and the trend terms are filtered out to obtain a smooth and normal drift signal. Then, the data fusion model based on time series analysis is built for the gyroscope array and the error analysis is performed by Allan variance. Finally, based on the AR (1) model, the moving horizon optimization Kalman filter method is used to filter the drift data of the gyroscope array. The experiment shows that when the time domain length N=3, the bias instability of gyroscope 1, 2, 3 and 4 decreases from 9.716 o/h, 8.5682 o/h, 13.484 o/h and 26.414 o/h to 1.2922 o/h, 0.61147 o/h, 1.4184 o/h and 1.6964 o/h, respectively, and the average noise coefficient decreases by more than 85%. Compared with the ordinary Kalman filter method, the bias instability has been significantly improved.
Study on an optimized grouping RAIM method
Authors: Yan Qin , Cai Chenglin , Jia Wei
Published: June 2021

Receiver Autonomous Integrity Monitoring (RAIM) method is widely used in the field of aviation navigation for its advantages of fast response, low cost and wide coverage. The performance of traditional RAIM is not as good as that of fault detection, and the calculation is complex. With the development of multi-constellation integrated positioning technology, the number of visible satellite is gradually increasing. Although the performance of traditional RAIM method has been improved, but it is not large, and the amount of calculation has increased greatly. In order to solve the above problems, an optimized grouping RAIM method is proposed. Through uniform grouping, fault detection can be directly used to complete fault identification, which reduces a lot of calculation and improves the efficiency and performance. The simulation results of graphics and data show that the algorithm is feasible and effective.
A Study on Recruitment of Data Analyst Based on Text Mining and Visualization Technology
Authors: Fang Fang , Zhou Yin
Published: June 2021

Nowadays, the demand for data analysts has increased dramatically. First the job requirements of data analyst are downloaded from online recruitment website ChinaHR.com and zhaopin.com, then the information of the recruitments are analyzed by text mining method such as word segmentation, word frequency statistics and visualization technology. At last we summarized the required skills for data analyst. We found that compared with Python, the company is inclined to use R for data analysis, the recruitment requirements of every type of company are different. Our findings can provide reference for schools and guide individual professionals to assess and advance their competencies.
Research on key technologies of edge computing in discrete manufacturing industry in the era of big data
Authors: Lu Guanghua , Liu Mingbo , Wang Zenghai , Gao Lei
Published: June 2021

Relying on the centralized operation feedback mode of cloud computing, the data processing capacity is improved, but the delay and energy consumption of discrete manufacturing industry are increased. A resource scheduling method for discrete manufacturing based on edge computing architecture is proposed. Based on the establishment of big data multi cluster edge cloud framework, the task priority of discrete manufacturing industry is determined. According to the task priority of each production link, the objective plan of resource scheduling and unloading is established to achieve real-time and efficient task resource scheduling. The experimental results show that the stability is higher than 78%, the real-time response rate is fast and the performance is better.
Comparison of Topsis Comprehensive Evaluation System and Computer BP Neural Network Simulation
Authors: Fan Yongjun , Liu Yijie , Xing Yunmeng , Liu Wenxuan
Published: June 2021

In view of the fact that the subjective determination method will be affected by natural and man-made factors, it has high uncertainty. In order to further improve the accuracy of the algorithm, considering the comprehensive effect of various factors has become the key to solving the problem. Therefore, the paper first uses the analytic hierarchy process to initially determine the weights, uses the fuzzy inference model to make preliminary predictions based on the similarity of the impact factor matrix, and then we use the Topsis-fuzzy comprehensive evaluation model to identify the impact factors, and screen out the reasonable predictors for the second time prediction. Finally, we use an example to test the effect of the fuzzy inference model based on the Topsis-fuzzy comprehensive evaluation model factor identification, and compare it with the BP model of the fuzzy optimization neural network for ice forecasting. The results show that the TOPSIS-fuzzy comprehensive evaluation model factor identification basis the above fuzzy inference model has higher prediction accuracy and better effect.
Application of Improved Neural Network Strategy in Emotion Information Discrimination
Authors: Huang Junlian , Zhao Dongyan , Lv Boxue
Published: June 2021

Emotional information recognition is an important application in the field of artificial intelligence. This paper analyzes the existing speech emotion recognition system, based on the improved neural network strategy to improve the accuracy of speech emotion recognition, through the combination of convolution neural network (CNN) and long-term and short-term neural network (LSTM), the emotional data information is successfully recognized, and the better accuracy is obtained.
Dependence Analysis of Insurance Businesses Based on Hierarchical Archimedean Copula Function
Authors: Tian Jing
Published: June 2021

The dependence between insurance businesses greatly influences the evaluation of insurance companies’ overall reserves. Because of the heterogeneity of risks, the dependence between businesses is often not exactly the same. In order to analyze the asymmetric dependence relationship, an asymmetric dependence structure based on hierarchical Archimedean Copula function is proposed. It is assumed that the loss distribution of business lines follows Log-normal, Gamma and Weibull distribution. And then a hierarchical Copula dependence structure among different businesses is established. By the empirical analysis of the historical data of CPIC’s automobile insurance, transportation insurance, enterprise property insurance and liability insurance, the optimal 4-dim hierarchical Copula structure is selected to analyze the dependence among the four. The empirical results show that automobile insurance and transportation insurance have the strongest dependence, followed by enterprise property insurance and liability insurance. At the same time, based on the obtained hierarchical structure, reserve assessment and risk measurement can be carried out, which provides an insight for analyzing the dependence among multivariate analysis.
Research on Algorithms of Fusion System of Artificial Intelligence University Curriculum Derivatives Based on Internet Big Data
Authors: Wang Yue , Sun Rui , Sun Weidong , Yu Tianbo
Published: June 2021

With the rapid development of artificial intelligence technology and the rapid progress of big data technology, based on the theory of artificial intelligence fusion systems based on the lives of college students, and the use of advanced technology, university courses have also expanded in multiple directions. A reasonable and scientific development model of electronic technology design. Derived by using electronic data as a carrier to optimize the derivative tools of university courses and improve performance in many aspects such as learning and sports. Using the empirical formula of the Big Data Fourier algorithm, the manual verification was verified through the statistical comparison and analysis of the competitive auxiliary review system. The application of intelligent systems in the fusion system of university curriculum derivatives and artificial intelligence algorithms based on Internet big data play an active role in the fusion system of university curriculum derivatives.
City Application Research Based on Computer Digital Information Technology
Authors: Meng Zisen
Published: June 2021

Advances in information technology have promoted the development of smart cities. Under the umbrella of building smart cities, the computer digital surveying and mapping geographic information industry builds an important spatial information infrastructure for smart cities by building a smart city spatio-temporal information cloud platform, and provides intelligent spatio-temporal carriers for smart cities. Based on this research background, the paper analyzes the positioning of computer digital geographic information in the construction of smart cities, and proposes the concept of geographic platform and its value in smart cities: spatial information resource sharing, ubiquitous information support and collaborative management.
Research on Positioning Accuracy of Passive Acoustic Positioning System Based on Feature Matching in Air
Authors: Peng Yan , Chen Kejian , He Jianfeng , Huang Wei , Xiao Xiu , Xiao Ke
Published: June 2021

Passive acoustic localization is an important interdisciplinary research branch which combines acoustics, communication and signal processing. Passive acoustic positioning system, as an important part of battlefield sensing and monitoring system, has been paid more and more attention. Due to the disturbance of battlefield and other environments and the existence of measurement errors, the positioning accuracy often cannot meet the requirements. Passive acoustic positioning system, as an important part of battlefield sensing and monitoring system, has been paid more and more attention. Due to the disturbance of battlefield and other environments and the existence of measurement errors, the positioning accuracy often cannot meet the requirements. In multi-sensor passive location, the measured data of each array element is not only related, but also compensatory and redundant, so some people use the optimal data fusion algorithm as post-processing algorithm to improve the positioning accuracy. In this paper, the positioning accuracy of ground passive acoustic positioning system is analyzed based on feature matching method, and some useful conclusions are drawn.