bluuebunny/crossref_metadata_2025_split huggingface dataset:
Numerical solution of the Stefan problem
Authors: Burago N G , Fedyushkin A I 
Published: February 2021

Abstract
The paper describes an algorithm for solving the Stefan problem by the finite element method for modeling heat and mass transfer processes in a fluid with a phase transition. Modeling of heat and mass transfer is based on the solution of the Navier-Stokes equations for an incompressible fluid in the Boussinesq approximation and the heat conduction equation for a solid phase. The solution was made according to the explicit-implicit scheme of the matrixless finite element method using a moving finite element mesh. The mobility of the grid nodes is due to the variable geometry of the solution region due to the motion of the melt-crystal interface. The new positions of the nodes of the moving mesh were calculated by the model of elastic media, providing the approximate equality of the volumes of the mesh cells. The grid nodes belonging to the moving boundary between the melt and the growing crystal moved in accordance with Stefan’s conditions. The auxiliary systems of algebraic equations for the nodal values of the desired functions were solved by the matrixless conjugate gradient method with preconditioning by using the diagonal approximation of the stiffness matrix. An example of the application of the described finite element implementation of the Stefan problem for modeling of process for semiconductor single crystal growth by the Bridgman method taking into account the rotations of crystal, crucible and heater-vibrator is given.
Diffusion of a reagent from a slowly rising droplet with accompanying surface chemical reaction
Authors: Denisova M O , Kostarev K G 
Published: February 2021

Abstract
The development of neutralization reaction during the reagent diffusion from an insoluble drop, slowly floating up in a quiescent chemically active liquid, was studied experimentally. The droplet is located in a narrow vertical gap, which causes it to take the form of a short horizontal cylinder with a free lateral surface and flat end faces. The latter circumstance allows using an interferometer to visualize the structure of the fields of reagent concentration in the droplet and the resultant products in the environment and to trace their evolution. To display the specific features of the observed phenomena, we also investigated the diffusion of a reagent from a motionless drop in a chemically active medium and diffusion of a reagent from a drop floating up in a chemically neutral liquid.
Experimental study of the effect of air oscillations on vapor diffusion in a channel of variable cross-section and in a granular medium
Authors: Polezhaev Denis , Kozlov Victor 
Published: February 2021

Abstract
The diffusion of 2-propanol vapor in the air in a channel of variable radius and in a porous medium composed of spheres of equal diameter under longitudinal oscillations is experimentally studied. In the experiments, vapor concentration at the top and bottom of the channel (or porous medium) is constant. In the absence of oscillations, mass transfer along the channel (or porous medium) is carried out due to molecular diffusion. When air oscillations are imposed, additional mass transfer effects are activated, namely, Taylor dispersion and convective mass transfer due to steady vortex flows. In the studied range of frequencies and amplitudes, the total mass transfer exceeds molecular diffusion by one order of magnitude. In a channel of variable radius, mass is transferred mainly due to the steady vortex flows (convective mass transfer) arising in the viscous boundary layer due to the inhomogeneity of the amplitude of air oscillations in narrow and wide sections of the channel. In a porous medium, Taylor dispersion plays a major role while the convective mass transfer makes minor contribution.
Effect of vibrations on thermal convection in thick rotating annulus
Authors: Vjatkin Alexei , Sabirov Rustam 
Published: February 2021

Abstract
The effect of transverse vibrations on thermal convection in a rotating thick cylindrical fluid layer is investigated experimentally. The layer rotates about the horizontal axis of symmetry. The temperatures of the layer boundaries are different (the outer boundary is cold) and maintained constant. The study is limited to the case of fast rotation. The centrifugal force of inertia plays a stabilizing role, bringing the fluid into a state of a stable mechanical equilibrium. The vibrations affect the equilibrium of the layer in a narrow frequency range close to the rotation frequency. The structure of the convective flows is studied using PIV-method. It is found that when the frequencies of vibrations and rotation definitely coincide, the convective flow has a form of the couple of symmetric two-dimensional vortices, the position of which is stationary in the cavity reference frame. The convection occurs under the action of an induced inertial force field (superposition of vibrational and centrifugal inertial force fields). With a frequency mismatch, the induced force field rotates in the cavity reference frame. The maximum heat transport corresponds to a resonant excitation of the azimuthal two-dimensional inertial oscillations of the non-isothermal fluid layer. The convective heat transport in this case is much higher than in the case of the frequencies coincidence. The dependence of heat transport, both under resonance conditions and with equal frequencies, on vibration parameters is studied. It is shown that the centrifugal and vibrational mechanisms play a key role in the development of the convection.
Designing GNSS HUMGAdj software package for surveying and mapping
Authors: Trong N G , Nghia N V , Cuc N T , Chinh D N , Cuong N V , Tinh L D , Quang P N , Hai N D 
Published: February 2021

Abstract
GNSS technology has made great contributions to the development of surveying and mapping in Vietnam. Many useful GNSS processing software packages have been created and widely used all over the world. However, since these software programs only have input and output, the new users without expert theoretical knowledge (especially new students) can not understand the principle or interfere with the process to obtain explicit results at each step. Therefore, the research team has built the GNSS-HUMGAdj software package to visually illustrate GNSS data processing steps for students to use. In the design stage, the group has learnt the experience in programming GNSS processing software, inheriting published GNSS data processing algorithms. In addition, some algorithms such as converted GNSS baseline in resolving the relative positioning problem, adjusting the receiver antenna height, and the effect caused by the change of distance over time were developed in the software.
Development of a Smart Solar Tracking (SST) system as a green renewable energy solution
Authors: Al Bartamani Bader K. K. , El-Saleh Ayman A. 
Published: February 2021

Abstract
Renewable energy is a type of energy generated from renewable resources that are naturally generated such as sunlight, waves, rain, wind and geothermal heat. Renewable energy provides energy in different categories such as electricity generation, air and water heating/cooling and transportation. Solar PV cells are the most common method for transforming the sun light to electrical power. But using a standstill PV cells is not very efficient due to sun movement as the PV cells must be perpendicularly aligned to the sun to get its maximum efficiency. Tracking the sun by a tracking system will increase the harvested energy and achieve the maximum power generated from the solar cells. In this work, we develop a solar tracking system that enables photovoltaic cells to continuously track the sun and study the effect of light incident angle on the photovoltaic cell’s efficiency. In this study, the use of PV cells with tracking capabilities is 21% more efficient as compared to conventional standstill PV cells.
SUIP: An Android malware detection method based on data flow features
Authors: Chen X R , Shi S S , Xie C L , Yang Z , Guo Y J , Fang Y , Wen W P 
Published: February 2021

Abstract
Currently static detection is the most commonly used in Android malware detection. Among them, the extraction of various features is particularly important. In analysing the data flow features of applications, researchers usually use taint analysis method to extract. However, this method lack intermediate process features. So in this paper, we analyse the features of Android components to obtain application data transfer features for complementing the application data flow features and build a more complete combination of data flow features. Based on this, we propose a new Android malicious application detection method—SUIP. This method complements the missing features based on taint analysis, and combines the LightGBM algorithm to build a detection model. Finally, we use the sample set in Virusshare for experiments. Compared with the traditional static detection method of Android malicious code, the result shows that our detection method has a high detection accuracy of 98.50%.
Research on optimization of thulium-doped fiber laser based on optical communication system
Authors: Zhang Ning , Chen Xiaodan , Yang Yansong , Sun Huijuan , Luo Yang 
Published: February 2021

Abstract
With the rapid development of optical communication network and related technology, the frequency resource of light wave is becoming more and more insufficient, which requires new light sources to support the communication system.With the continuous development of fiber laser technology, Tm-doped fiber laser appears, which brings new vitality to the optical communication network with insufficient frequency resources. Because Tm -doped fiber laser can provide multiple frequencies of optical wavelength resources, it has attracted more and more attention. The development of rare earth doping technology and double cladding pumping technology has laid a solid foundation for the design of Tm-doped fiber laser with excellent performance. In this paper, the Tm-doped fiber laser is studied. The effect of each element in the Tm-doped fiber laser on the laser is analyzed. The influence of the reflectivity of the mirror on the performance of the whole laser is discussed. The simulation results show that the reflectivity of the mirror will seriously affect the output power of the laser, which is of great significance for the design of fiber lasers.
Investigating batch normalization in spoken language understanding
Authors: jagdale Sheetal , shah Milind 
Published: February 2021

Abstract
Spoken Language Understanding (SLU) is an important component of the Spoken Dialogue System (SDS). SLU plays a very important role in understanding the user goal. SLU represents user utterance into a semantic representation which helps to understand user intension. SLU performs this task by using learning models from machine learning. These machine learning models suffer from changes in the distribution of input to each layer of the deep learning network. This reduces the speed of training and affects model performance. Thus, the performance of SLU incorporating the deep learning model is affected. In machine learning, techniques such as batch normalization are proposed to reduce the variation in distribution at each layer of the deep model. In this work, an investigation carried on SLU by incorporating batch normalization is reported. The evaluation parameters used for experimentation are F-score and balanced accuracy. The F-score and balanced accuracy for the belief tracker is 0.971 and 0.93. Thus, there is a 3.7 % improvement in F-score and 0.7 % improvement in balanced accuracy than the model without batch normalization which will aid in understanding user goals. Thus, the performance of SLU is improved.
Knowledge push system based on work breakdown structure and ontology
Authors: Shi L 
Published: February 2021

Abstract
The phenomenon of knowledge overflow and knowledge disorientation is very common in knowledge-intensive enterprise, even though the knowledge management system has been used. A novel knowledge push system is designed in order to push proper knowledge actively to the proper designer at the proper time, which is oriented to the product design workflow based on work breakdown structure. The ontology models of product design task and knowledge are established, and fuzzy properties are introduced into knowledge ontology model. A similarity measurement algorithm between ontology models is proposed, which generates the knowledge matching rule. Integrating ontology construction, knowledge matching rule and knowledge control model, a knowledge push system is constructed that is used to achieve precise knowledge pushing. An electronic equipment manufacturing enterprise is taken as the application case to verify the effectiveness of the system.
A blockchain-enabled 5G authentication scheme against DoS attacks
Authors: Chow Man Chun , Ma Maode 
Published: February 2021

Abstract
The 5G network is designed to accommodate the increasing number of connected devices with higher speed, lower latency, and better security. To improve the network security and robustness, the Third Generation Partnership Project (3GPP) has standardized the 5G-AKA protocol for mutually authenticating user equipment (UE), base stations, and the core network. However, since there will be more devices in the 5G network, the denial-of-service (DoS) attacks are much easier to be carried out than ever before. In this paper, we address the security issues in the 5G network by introducing the blockchain-enabled authentication and key agreement scheme for the 5G Networks. Our proposed scheme uses private blockchain to provide a distributed database to store all authentication records. Also, we exploit the trapdoor collision property of the chameleon hash function, such that the entries in the blockchain can verify the incoming authentication requests. Furthermore, a subscription concealed identifier (SUCI) is mandatory in our protocol to protect the anonymity of the devices, and ECDH is employed to generate a session key. We use Scyther Tool to verify our protocol formally, and the security analysis shows that our protocol can achieve perfect forward secrecy, device anonymity, and mutual authentication and key agreement. Our scheme is also resistant to replay attacks, and most importantly, the DoS attacks. Finally, performance evaluation shows that our scheme is efficient for both UEs and base stations with rational computational costs.
A Freeform Lens System Design and Simulation in the Polar Coordinate
Authors: Gao Tongrui , Lou Jun , Zeng Maoting 
Published: February 2021

AbstractIn the field of illumination engineering, freeform technology is playing a more and more important role. Several methods have been reported in recent papers. The paper introduce a design method to generate an ellipse spot in the polar coordinate using the polar grids based on flux transportation mapping. In this method, the source is a point and the point is divided along the azimuth angle and zenith angle in the polar coordinate system. Then we divided the flux target in the polar coordinate, the grids of the target are achieved by the mapping between the source and the target. Based on the mapping and energy conservation, we can derive a set of the first-order PDE according to Snell’s law. We can acquire a points cloud after solving the PDE numerically, then we will construct a smooth freeform using Rhino. Finally, we will test the freeform using Light Tools. With this method, we can design a lens with the light utilization efficiency over 0.8. Keywords: LED; Freeform; Mapping; Polar coordinate.
Formulation of a Refined Nonlinear 8-noded Brick Element for Simulation of Manhole under Vehicle Loads
Authors: Kim Changwan , Cai Songbai 
Published: February 2021

Abstract
Establishing a calculation procedure of stress and residual deformation of manhole under vehicle impact loads is meaningful for improving the design and rehabilitation of the manhole. By using corotational procedure, this paper presents formulation of a refined nonlinear 8-noded brick element. Theoretically, the element is capable of analyzing very large deformation in efficiency, and has the advantage of adopting to any kind of nonlinear material model. A rigorous continuum mechanics basis to the corotational framework is provided and a corotational kinematical model for geometrically nonlinear analysis is also derived with locking reduction in 3D brick elements.
Model Simulation Used to Analyse the Accuracy of the Temperature Control and the Pressure Control
Authors: Zhang Helin , Chen Qingmei , Zhang Kang 
Published: February 2021

Abstract
In this paper, In view of the traditional temperature control and the spray gun pressure control in the coating drum of the current medicine coating machine, the temperature control: adopting the intelligent control domain’s mold and PID control method, the model simulation is used to verify the accuracy of the temperature control and the pressure control: taking the pressure of the powder outlet of the spray gun as the input of the closed-loop feedback, the pressure of the powder outlet can be kept constant and the coating demand of the medicine in the pot can be well ensured.
The Data Analysis of Shanghai Air Quality Index Based on Linear Regression Analysis
Authors: Jiang Wenrong 
Published: February 2021

Abstract
In this paper, the actual data related to air quality in Shanghai is selected, and six factors such as PM2.5, PM10, SO2, NO2, O3 and CO concentration are used as the alternative factors affecting AQI. The Pearson correlation coefficient between these six factors and the air quality index was calculated separately, and the correlation between the variables was analyzed. This paper considers the multicollinearity between the six factors, in order to reduce the influence of multicollinearity on the model, comprehensively consider the elimination of some alternative factors. Then use spss software to analyze in depth, take AQI as the dependent variable, and the other factors as the independent variable to carry out multiple linear regression analysis. Finally, the multiple linear regression analysis equation is obtained and predicted based on this model. The results show that the model is for calculating air. The quality index is more accurate. This model is simpler and more efficient than the original AQI calculation model.
Pattern Synthesis of MIMO Radar Based on Immune Differential Evolution Algorithm
Authors: Jiang Ling , Jiang Yi , Chen Guangfu , Shi Guimin , Cheng Qi 
Published: February 2021

Abstract
In order to optimize the pattern synthesis of multiple input and multiple output (MIMO) radar, immune mechanism is adopted to overcome the premature risk of differential evolution (DE) algorithm, namely immune differential evolution (IDE). Firstly, the modeling of MIMO radar is introduced by encoding the position of array in the binary. Secondly, the immune mechanism is employed to improve the DE. In IDE, two parameters are self-adapted for the mutation operator by immune mechanism to enhance the convergence ability of DE, including scaling factor and crossover rate. Several experiments are conducted to analysis the performance of IDE. The simulation results show that the IDE with variable parameters can get optimal results in MIMO radar with lower the peak side-lobe level (PSLL) and maintain the diversity with stronger convergence ability and shorter calculation speed.
Assistant Diagnosis of Insanity Based on Infrared Thermal Image Analysis and Deep Learning Algorithm
Authors: Wang Yeping , Wang Xi , Xiao Peng , Chen Cheng , Xiao Ruoxiu , Wang Yanshen , Lu Yuanyuan , Wang Zhiliang 
Published: February 2021

Abstract
Considering the lack of in-depth research on the cases of insanity and other mental diseases in the context of traditional Chinese medicine, an deep learning based algorithm which can realize auxiliary judgment function of insanity are proposed in this paper. First, the original image set is screened and then an improved U-net network is used to realize the division of the trunk and limbs of the human body, thus preventing interference from disease-independent areas to affect subsequent disease judgment. Finally, based on the classification of insanity, the reference function of visual analysis is added. 1508 IR images are divided into two groups to test the proposed method. And experimental results show that accuracy of the classification of insanity diseases can reach 0.92, which has a high reference value for the clinical diagnosis of insanity.
Research on Image Segmentation Algorithm Based on Component Tree
Authors: Guo Yonghui , Li Yuntao , Zhang Yu , Zhou Zheshuai 
Published: February 2021

Abstract
The key part of sea target recognition is to search for the possible ship targets in the image. For the problem that the standard segmentation of threshold algorithm is not effective in the complex sea condition, in this paper, a component tree image segmentation method based on minimum error threshold and ship area is proposed for ship target recognition. Firstly, area criterion is used to filter the image, then minimum error threshold method is used to construct the component tree and determine the filtering mechanism, finally, gray level criterion is used to filter the component tree. The simulation results show that proposed method is effective.
Research on the Computer Controlled Velocity Simulation Device for Continuous Totalizing Automatic Weighing Instruments
Authors: Zhong Ruilin , Wu Di , Wang Jian , Chen Hanghang , Cai Changqing , Hu Manhong , Jiao Kai , Ding Jing’an 
Published: February 2021

Abstract
Continuous totalizing automatic weighing instruments is widely used in many industries, and need to be tested under different conditions especially for different temperature, humidity and electrical disturbance. Usually this kind of weighing instruments are very large and can not be put into such test environments, thus a test sample without belt conveyor is needed. Due to the working principle of continuous totalizing automatic weighing instruments, the test sample may include not only essential part of weighing instruments such as load cell, indicator, and load receptor, but also a device to simulate the displacement of the belt. In the paper, a device that can simulate the velocity of the belt is researched, it can generate square pulse signals to the test sample, thus the sample can operate as normal belt weigher. The configuration of the device is discussed and example is given to show its effectiveness.
Design of a High Precision Data Acquisition System of Weak Signal
Authors: Gao Wei , Mao Weiwei , Zhang Zhiguo 
Published: February 2021

Abstract
In order to solve the problem of high precision acquisition of weak signals, a high accurately weak signal acquisition system has been designed in this paper. According to the proposed design requirements of the data acquisition system, the hardware acquisition circuit and the drive circuit as well as the processing of the upper computer are divided into modules. As the central work of this paper, the hardware and software of the drive modules are designed with specific flowcharts are given. And the designs of the system were debugged, analyzed and tested through experiment tests, and the high precision data acquisition of 0.5V DC signal has been obtained with specific datum are provided. The effectiveness of the proposed design to data acquisition of weak signal has been validated by the experimental results, and this design could be used in engineering projects.
Electrophysics and optics in topological quantum nanophotonics of low-dimensional systems
Authors: Arakelian S. M , Buharov D. N , Khudaiberganov T. A , Osipov A. V 
Published: February 2021

Abstract
This work has been carried out on the basis of the fundamental areas of optics and electrophysics of topological nanoscale objects with an emphasis on demonstrating the work of the developed prototypes of the corresponding practical devices and on their test tests.