bluuebunny/crossref_metadata_2025_split huggingface dataset:
Developing the operating principle and mathematical model of the downhole device for injecting scCO2 in productive formations
Authors: Pavlova P L , Guzei D V 
Published: November 2021

Abstract
Traditional technologies are not economically efficient in term of processing heavy and extra-heavy oils. Technologies based on the use of supercritical fluids (SCF) may become one of the innovative directions in the production and processing of heavy and extra-heavy oils. Therefore, in this paper the operation principle of the downhole device for pumping scCO2 into a productive reservoir is developed. The mathematical model is developed either. Calculations with different heat flux densities on the channel wall are carried out. The dependences of the temperature distribution along the length of the heated section are obtained. The calculation results are compared with experimental data.
Representativeness of monitoring station readings in the context of urban environment
Authors: Meshkova V D , Dekterev A A , Litvintsev K Yu 
Published: November 2021

Abstract
In this paper, a comprehensive analysis of the interaction of the urban environment elements with the natural environment components is carried out. The assessment of the complex impact of meteorological parameters on the human body is analyzed based on data obtained from monitoring stations. The readings of monitoring stations concerning both wind speed and directions are found to significantly deviate in different parts of the city due to urban development. A numerical study of the neighborhood with the monitoring station also shows a very complex mechanism for determining the pollution intensity of the area and the relevance of the data obtained, especially concerning pollutants.
Analysis of the influence of dust formation on technological processes in the production of PET
Authors: Geller Yu A , Antanenkova I S , Aparushkina M A 
Published: November 2021

Abstract
Possible methods of dust formation during the production of polyethylene terephthalate granulate and its preparation for molding are considered. The features and patterns of dust formation during drying in an active hydrodynamic layer at different speeds and temperatures are revealed.
The Application of Brain-computer Interface (BCI) based Functional Electrical Stimulation (FES)
Authors: Liu Tianhang 
Published: November 2021

Abstract
Rehabilitation medicine has developed rapidly in recent years. Brain computer interface and functional electrical stimulation are very cutting-edge technologies in this field. Because brain computer interface provides a real-time operation platform for patients to operate their limbs according to their intention for functional electrical stimulation, the research on BCI based FES has gradually increased in recent years. This paper discusses the current development status and technical application of FES and BCI. The research status of BCI based FES is discussed, and the existing problems of various research are summarized. According to the research findings, this field is a new technology with great application prospects in the field of modern rehabilitation engineering.
A Triple-threshold-based Load Event Detection Algorithm for Non-intrusive Load Monitoring
Authors: Chen Mingming , Fang Kaijie , Huang Qifeng , Yang Shihai , Cheng Hanmiao , Liu Tianchang , Huang Yixuan 
Published: November 2021

Abstract
Event detection is an important foundation of non-intrusive load monitoring algorithm. In this paper, the common household appliance load events are classified, and a new triple-threshold event detection algorithm is proposed aimed at solving the problems of false detection and missing detection in the practical application. Firstly, a low power threshold is used to realize high-sensitive detection of the load events, and secondly the detected events are spliced according to the time threshold to get the complete events. Thirdly, the high threshold is used to discriminate the complete event set to filter out the disturbance caused by load fluctuation. Finally, the results are modified with a correction logic. The test results carried with static data show that, the algorithm proposed in this paper is more accurate for positioning the time of putting into and cutting off load, which is conducive to improve the accuracy of transient interval interception of load events, and has advantages in detecting slow rising load events. In addition, the algorithm proposed in this paper has a small amount of calculation, which can meet the requirements of application in the hardware of smart meter.
Investigation of Base Transport Mechanism in Silicon-Germanium Heterojunction Bipolar Transistor Operating over Wide Temperature Range
Authors: Yu Guofang , Cui Jie , Zhao Yue , Fu Jun , Ren Tian-Ling 
Published: November 2021

Abstract
A high breakdown voltage silicon-germanium heterojunction bipolar transistor operated over a wide temperature range from 300 K to 10 K has been investigated. The measured Gummel characteristics illustrate that the collector current and base current both shift to the higher voltage as the temperature decreases. The fT/fmax are extracted to be 23/40 GHz at 300K, 28/40 GHz at 90 K, and 25/37GHz at 10K, respectively. The effective amplification range becomes narrow as the temperature decreases. And the ideality factor of base current in the low current region is shown to be temperature-dependent and its value is much larger than 2 at cryogenic temperatures. This phenomenon indicates that the base current is not only contributed by drift, diffusion, and Shockley-Read-Hall recombination, but also by trap-assisted tunneling. The Hurkx local trap-assisted tunneling has been used to analyze the non-ideal base transport mechanism. And a calibrated TCAD device model is developed to further verify this non-ideal transport mechanism.
Tunable mid-infrared laser sources for trace-gas analysis
Authors: Kolker D B , Sherstov I V , Boyko A A , Nyushkov B N , Erushin E Y , Kostyukova N Y , Akhmathanov A I , Kiryakova A Y , Pavluck A V 
Published: November 2021

Abstract
We demonstrate advanced experimental approaches to photoacoustic gas detection with tunable mid-infrared (mid-IR) laser sources of different types. A gas analyzer for registration of various gas components based on a tunable narrow-linewidth optical parametric oscillator (OPO) was designed and investigated. Using this OPO, the possibility of measuring the trace concentration (∼2÷3 ppm) of methane (CH4) in air was experimentally shown. The gas detection capability was enhanced by introducing injection seeding into the OPO. Another gas analyzer was based on a quantum cascade laser (tunable within the range ∼7.6 ÷7.7 μm) and a resonant differential photoacoustic detector. Detection of the ultra-low concentration (∼0.3 ppm) of methane in air was achieved (the standard dispersion was (1σ) ≍ (10–11) ppb with an integration time of 10 s). We compare the presented approaches and outline their further development.
Effect of terahertz radiation on intermolecular interactions of albumin under aerobic and anaerobic conditions
Authors: Nemova E A , Dultseva G G , Nikolaev N A , Cherkasova O P 
Published: November 2021

Abstract
The effect of THz radiation on coupling between albumin molecules under aerobic and anaerobic conditions is assessed through an EPR-quantified procedure. Rearrangements induced by terahertz radiation are found to affect the hydrogen bonding network causing an increase in the rate of bimolecular interactions. Molecular mechanism of the observed effect is considered involving the interactions between the functional groups of albumin molecules. Irradiation causes conformational changes in albumin molecules, which involves changes in the steric states of molecules. These rearrangements hinder or simplify the adsorption of specific agents on the reactive sites of albumin molecules.
Theoretical bases of combined nonlinear optical demodulator-amplifer for broadband microwave photonics system
Authors: Nikolaev G N , Mikerin S L 
Published: November 2021

Abstract
Our demodulator is based on the use of a strong light pump wave along with a signal modulated light wave. The demodulator is linear in terms of the modulation signal, which makes it possible to obtain a demodulated signal without harmonic distortion. The modulator conversion efciency and signal gain increase with increasing microwave baseband.
Controlled Fractional Order Processes with Distributed Parameters
Authors: Mamatov Mashrabjon , Alimov Xakimjon 
Published: November 2021

Abstract
This work is devoted to the study of the problem of pursuit in systems controlled with distributed parameters of fractional order. Derivatives with respect to spatial variables are ordinary, integer, and even of arbitrary order. Designed and studied sampling schemes. A numerical method is constructed for finding strategies in suitable classes and for constructing the corresponding control laws. Theorems are proved for the possibility of completing the pursuit by the finite difference method, and they can be used to solve finite-difference optimal control problems or numerical solutions of differential games of fractional order. Problems of the type under study are encountered in modeling the processes of economic growth and in problems of stabilizing dynamic systems.
The Mathematical Analysis and Classification Research of an Iris Data Set Using Binary Tree and Grey Relation Grade
Authors: Feng Chiang Ling 
Published: November 2021

Abstract
The data from an Iris flower database is studied. The Iris database is the most commonly used database for machine learning algorithms. The Iris database was developed by Ronald Aylmer Fisher in 1936. The Iris database has 150 records in three categories: Iris Sentosa, Iris Versicolor and Iris Virginic. The database has four attributes: sepal length, sepal width, petal length and petal width. For the machine learning algorithm, 150 Iris flower databases are used. Of the 150 Iris in the Iris database, 80% are used as the training set and the remaining 20% Iris as the test set. In machine learning, to perform classification and discrimination is a complicated and difficult thing. In this study, a grey relation grade is used to extract the main features of the Iris flower and a Binary Tree [1] is used to classify the Irises. The results show that for the same specific attributes, grey relation grade extracts the main attributes and can be used in combination with a binary for classification.
Discrete Schemes for a Class of Semilinear Hyperbolic Eqution
Authors: Xu Jing , Jiang Xiaoli 
Published: November 2021

Abstract
This paper focuses on the numerical algorithm of a class of semilinear hyperbolic equation. The dissipation term and external force source term existing in the equation enhance the nonlinearity of the model and make the nonlinear effect complicated. However, this nonlinear effect has a great influence on the discrete scheme, which cannot be neglected. Discretizing the nonlinear terms to ensure the validity of the scheme is the core issue in this paper. An effective scheme based on linearization techniques and iteration theory is proposed. It is based on the finite difference method. The efficiency of the proposed schemes was verified via some numerical examples showing that they compare well with existing methods.
A Classification Algorithm: Data Mining and Mathematical Model
Authors: Cheng R , Kong X , Yu M , Wang N 
Published: November 2021

Abstract
In this paper, we propose a classification algorithm based on Recency-Frequency-Monetary (RFM) model and K-means data mining method. In addition, the designed algorithm is verified by the experiments on the member data in a large shopping mall. The experiments results show that the proposed algorithm can provide an accurate classification of the members. Finally, some marketing strategies for different classes of members are given according to the classification results.
The Uniqueness of Solution to the Inverse Eigenvalue Problem for an Arrow-shaped Generalised Jacobi Matrix
Authors: Huang Hongliang , Wang Qike , Li Zhibin , Wang Lidong 
Published: November 2021

Abstract
This paper studies the inverse eigenvalue problem for an arrow-shaped generalised Jacobi matrix, inverting matrices through two eigen-pairs. In the paper, the existence and uniqueness of the solution to the problem are discussed, and mathematical expressions as well as a numerical example are given. Finally, the uniqueness theorem of its matrix is established by mathematical derivation.
Design of Fuel Supply Curves for Aircraft Center of Gravity Balance Based on DCT Compression
Authors: Wei Yawen , Su Bo , Wang Xuru , Li Zhen , Wang Pengfei , Feng Xiangchao 
Published: November 2021

Abstract
The center of gravity (CG) has a significant influence on the controllability, stability, and fuel efficiency of the aircraft. For the aircraft with multiple fuel tanks, the CG position can be controlled by the fuel quality of different fuel tanks during flight. In this paper, an optimization method based on discrete cosine transform (DCT) compression is proposed to solve the optimization strategy of aircraft multi-tank fuel supply according to the current aircraft mission and engine working requirements. The transform coefficients of the low frequency components are used as design variables to represent the fuel supply curves. The improved KS function is proposed to deal with constraints. The numerical example is demonstrated to verify the effectiveness of the proposed method.
Finite Analysis of Support Time for Tunnels in Strain-softening Rock Mass in Consideration of Fictitious Support Pressure
Authors: Cui Lan , Sheng Qian , Niu Zhenzhen 
Published: November 2021

AbstractThis study considers that the support time is quantitatively determined by the production limit of the displacement reduction factor and the support force under the extrusion conditions of the strain-softening rock mass. Therefore, the two indicators of the downlines under the support time are the displacement reduction factor of the support force and the yield limit. Based on the solution of the fictitious pressure proposed in an existing paper, the finite difference method is adopted to investigate the variations of the support force and displacement reduction factor versus the delayed distance considering different support types, initial stresses, and post-peak behaviours. The results show that on the one hand, the delay distance is suggested within 1 R0 in most tunnel cases; on the other hand, the factors have greater impact on rock-support interactions are rock mass and in-situ stress. Relatively contrast, softening and expansion behavior was not significant enough. Furthermore, it is also very important in composite support systems to assess the proportion of loads shared with the weakest part.
A Novel Route Planning Scheme Based on Dynamic Time Variables
Authors: Zhang Jinghe , Li Lei , Zhang Yuechao , Cheng Shaofeng , Fang Weidong 
Published: November 2021

Abstract
In this paper, the processing method of dynamic time variables in the route planning nodethat we designed involves the field of route planning, including determining the route time and stay time, combining the floating reserved time to determine the redundancy; after the entity has visited a node, the current value is calculated Redundancy: According to the calculated redundancy value, combined with the preset redundancy threshold, the entity’s route and stay time are reminded. By converting the dynamic time variable into a fixed value, the model can complete the search for the optimal path within a limited time. At the same time, the concept of reserved floating time is introduced, thereby retaining the dynamic characteristics of time, so that visitors can have sufficient time stay, and can complete the stay according to the fixed time requirements, can effectively track the stay time and make corresponding processing in the corresponding situation to ensure the stay ability. The proposed scheme has better performance.
Research on Modeling and Power Algorithm of Photovoltaic Cells for Solar Cars
Authors: Zhong Yan , Yang Qing , Zhang Yanzhong 
Published: November 2021

Abstract
Solar photovoltaic cells will be an effective supplement to electric vehicle batteries. In order to make the photovoltaic system of the solar car provide reliable power, this paper models the photovoltaic cell and designs the maximum power point (MPP) tracking algorithm based on three-point sampling with a fixed voltage. In addition, considering that the output power will change when the voltage and radiation intensity change under the peak power of the solar vehicle, the prediction of the peak output power of the photovoltaic array considering the influence of the radiation intensity and battery voltage is put forward for the first time. Experiments show that the designed power algorithm runs stably, and the power generation power prediction error is less than 1%. The peak output power prediction of the photovoltaic array takes into account the effects of real-time radiation intensity and battery voltage fluctuations, making the peak power prediction of the vehicle more accurate.
Modeling and Analysis of Different Architecture for Civil Aircraft Hydraulic System
Authors: He Xunan , Kang YuanLi , Hui Yannian 
Published: November 2021

Abstract
For the evaluation of civil aircraft hydraulic system, Fuel Consumption is a very important index. However, there is no effective method to perform analysis for different architecture. This paper proposes that taking fuel weight penalty as a major mathmatical modeling method to analysis traditional architecture and more electric architecture. The result shows that the fuel consumption of more electric architecture is less than traditional architecture.
Modeling and Finite Analysis of Overall Structure Mechanical Behavior of Steel Frame—Cold-formed Thin-walled Steel Composite Wall
Authors: Liang Huqing , Tang Mengxiong , Huang Ruicong , Jiang Zhengrong , Qiu Junming , Cai Jian 
Published: November 2021

Abstract
Based on the finite element method, the typical layout and parameters were selected to establish the overall structure model of steel frame—cold-formed thin-walled steel composite wall and their influence on the mechanical properties and the economic steel amount was analyzed. The results show that the screw spacing, purlin section and purlin spacing have little effect on the lateral stiffness and the amount of steel used in the overall structure, while the width of wall opening has obvious effect. It is suggested that the screw spacing should be consistent with the relevant provisions in the cold-formed thin-walled steel structure specification, the purlin section should be selected relatively small according to the wall thickness and the purlin spacing should be properly amplified. The applicable height of this structure system is higher than that of pure cold-formed thin-wall steel structure system in ordinary residential buildings. The amount of steel used in this structure system is obviously less than that of pure steel frame structure system.
A Failure Propagation Analysis Method Based on 3 X 3 Hierarchical Model
Authors: Pang Shujie , Jiao Jian 
Published: November 2021

Abstract
In recent years, with the increasing complexity of equipment, system design and safety analysis for the equipment are becoming more and more difficult. In this paper, we make a more comprehensive analysis of the hierarchical relationship of the system from the vertical and horizontal angles and put forward the 3 × 3 Hierarchical Model. Then, we propose a failure propagation analysis method based on 3 × 3 Hierarchical Model. At the same time, SysML is used to build the models, which is convenient for different people to learn and modify the models. Finally, a hydraulic transmission system is taken as an example to illustrate the feasibility of the method.
Numerical simulation of wave phenomena using FreeFEM
Authors: Hasanah U , Pudjaprasetya S R 
Published: November 2021

Abstract
In this research free surface motion governed by the shallow water equations is considered. A numerical scheme based on the finite element method, which is incorporated in the open source FreeFEM, was used to simulate several wave phenomena. By carefully setting the corresponding initial condition as well as boundary conditions, several numerical computations were conducted. Numerical simulations presented here are standing wave in a closed basin, progressive wave over a flat bottom, as well as wave shoaling over a decreasing depth and wave refraction. In all cases above, the existing analytical formula are used to validate the numerical results. These computations suggest that explicit-implicit scheme is appropriate for varying water wave simulations.
Basic analysis on heat transfer phenomena in natural circulation for liquid sodium
Authors: Wulandari R , Permana S , Suprijadi  
Published: November 2021

Abstract
Natural convention, the heat transfer on fluid due to density differences that can be caused by differences in fluid temperature. One example application of natural convection is cooling system, such as nuclear reactor cooling system. The purpose of this study is to analysis the basic characteristic heat transfer of sodium liquid in the natural circulation system for steady state analysis and transient characteristic with Finite Element Method. The selected module is the Non-Isothermal FLow (NITF) module. This module is a combination of three basic equations, namely the continuity equation, the Navier-Stokes equation, and the dynamic equation of heat transfer in fluid. The simulation model measures 1.5 x 2 (m) with sodium liquid (Na) as a fluid.
Research and practice on optimal design method of the oilfield water injection system pipeline network
Authors: Qu Fengjiao , Liu Tingting , Zhang Zhiming , Xie Weiyi , Wang Yansong , Wu Zanmei , Liu Yuhan , Liu Yun 
Published: November 2021

Abstract
The efficiency of oilfield water injection system is generally low and energy consumption is high. With the deepening of oilfield exploitation, the water cut of the oilfield is increasing, the power consumption of the water injection system is increasing year by year, the oilfield exploitation cost is increasing, and energy conservation and consumption reduction are very important. In order to improve oilfield water injection efficiency and reduce water injection energy loss, this paper puts forward the pipe network optimization design method of partial pressure water injection, establishes the mathematical model of partial pressure water injection pipe network and throttling loss calculation model, compiles the calculation software of partial pressure water injection mathematical model, optimizes the partial pressure interval, calculates the partial pressure points, effectively reduces the energy loss of water injection system and improves the efficiency of water injection system.
Study on the impact of confining pressure on gas permeability of tight sandstone cores
Authors: Tong Jianxiang , Wang Hengyang , Wang Yuyi , Zhang Ya , Huang Xiaohe 
Published: November 2021

Abstract
Taking the tight sandstone core of Shengli Oilfield as the experimental sample, this paper studies the permeability variation of the tight sandstone under different confining pressures. The experimental results show that when the pore pressure is constant, the measured gas permeability of core decreases with the increase of confining pressure. Power function is more reasonable to describe the influence of confining pressure on permeability of tight sandstone between power function and exponential function. Analyze the impact of confining pressure on gas permeability of tight sandstone cores by using permeability change rate coefficient D and coefficient S.