bluuebunny/crossref_metadata_2025_split huggingface dataset:
Computational Simulation Study on the Influence of Spray/Wall Impact on the Mixing Characteristics of Bipropellant Centrifugal Apogee Engine
Authors: Zhang Zhen , Yu Yusong , Cai Kun , Wang Fengshan 
Published: November 2020

Abstract
The present research investigates the impingement between spray droplets and two different coating walls is investigated to analyse effects of impingement on the mixing characteristics of propellants. In a mechanism experiment, a droplet with variable Weber number impinging on the coating walls at different wall temperatures is observed to have different behaviors, including spread, breakup, splash, suspension and rebound. Through this experiment, we establish a mathematical impinging model of these two coatings, which are identified by wall temperature and incident Weber number. These models are taken into the simulation to describe the mixing characteristics of two propellants under thermal atmosphere. The results indicate a significant difference in the mixing situation for two coatings impingement, showing a good agreement with experimental results of firing tests. Compared with SiCrTiZr coating, MoSi2 coating significantly benefits better mixing to improve combustion efficiency with lower temperature simultaneously, because more droplets get into impingement regimes of rebound and participate into central combustion. Therefore, oxygen-rich combustion area is centralized away from chamber wall, which is conducive to survival of liquid cooling film.
Simulation on Escaping Process in Closed Construction Based on Multiple Model
Authors: Wang Wenzhao , Gao Wanchun 
Published: November 2020

Abstract
In order to obtain the optimal escaping route in closed building and evaluate the escaping time, an evacuation model was established. The cellular automata model and ant colony algorithm was utilized in this process. Firstly, the cellular automata model was used to estimate escaping time. Using distances from individual locations to the exits to build risk of each point, then the evolving process was modified by factors like ability of individuals for innovation which can reflects escaper’s health, ratio of flurried people and the rules of people entering into next floor. Besides, ant colony algorithm method was used for the optimal routine. The equations of information judgement and accumulation was used, then take the broken down exits into consideration for an innovation. In the end, estimated escaping time and optimal evaluation route of Louvre was obtained by this model as a check and through the results some suggestions in evacuation was concluded.
Synthesis, Biological Evaluation and in Silico Studies of Several Substituted Benzene Sulfonamides as Potential Antibacterial Agents
Authors: Zhang Aimin , Li Wei , Liu Xiaofang , Wu Minggen , Xuan Guangshan 
Published: November 2020

Abstract
Four substituted benzene sulfonamides were synthesized to obtain antibacterial agents. The antibacterial activities were evaluated by the cup plate method. Compound 2d showed the most obvious inhibitory effect on seven kinds of strains with MIC ranging from 16 to 64µg/mL. The inhibitory effect of compound 2d on A. niger, C. albicans, B. subtilis, and S. aureus was better than that of the control drug SAN. Moreover, the cytotoxicity was evaluated by MTT assay. Finally, the binding patterns of the compounds with dihydrofolate synthetase and the prediction of oral bioavailability were preliminarily studied by computer simulation. The molecular docking result revealed that compound 2d had a stronger interaction with dihydrofolate synthetase than SAN. The oral bioavailability prediction by Molinspiration online program proved that these compounds exhibited drug-like properties. In conclusion, compound 2d is promising as a new antibacterial agent.
Research on Logistics Simulation and Optimization of Die Forging Production Line Based on Flexsim
Authors: Cheng Qiang , Shen Hongchao , Chu Hongyan , Liu Zhifeng , Zhang Caixia , Ren Jiaxiang 
Published: November 2020

Abstract
Long forging production cycle and low equipment utilization are the important problems currently facing domestic die forging ring production lines. To solve this problem, a simulation optimization method for die forging production line based on Flexsim was proposed. Firstly, the ECRS theory method was used to analyze the bottleneck process of the production line. Then, built a logistics simulation model of die forging production line based on Flexsim, The parallel and cycle processing steps was set reasonable parameters and simulated. Next, through logic analysis, methods such as adding processing equipment, improving equipment efficiency and balancing equipment handling tasks were used to optimize and improve the production line. Finally, compared and analyzed the original and optimized model. The simulation results show that the optimized production line equipment task allocation tends to be rationalized, the equipment utilization rate is increased by 4.34%, and the product cycle time is reduced by 27.65%, and optimized planning and design are achieved.
Simulation Study on the Average Specific Kinetic Energy and Safety Radius of Stun Grenade Fragments for Different Initiation Point
Authors: Wang Jiaying , Zhan Renjun , Liu Xingyu 
Published: November 2020

Abstract
In order to evaluate the lethality and injury radius of fragments and weaken the average specific kinetic energy, the calculation model of average specific kinetic energy of stun grenade fragments is established based on the Monte Carlo subdivision projection simulation. With the joint simulation method of LS-DYNA and programming, the calculation model of the specific kinetic energy of the semi-prefabricated fragments is solved and compared at different initiation points of the same charge. The mass distribution, vertical target distribution, average specific kinetic energy threshold and safety radius of the whole time-domain fragments at the initiation points 1.5cm, 3cm, 4.5cm, 6cm, 7.5cm and 9cm from the top of the shell are obtained. For the same charge parameters, the results show that the number of fragments near the initiation point of the charge center is less, the mass mean value and standard deviation are larger, and the threshold value of specific kinetic energy is lower than that of both ends of charge; the injury radius of the initiation points 1.5cm, 6cm and 9cm is 4.9m, 2.94m and 4.1m respectively. The initiation point near the charge center can significantly reduce the injury radius of the fragments and improve the safety of the stun grenade.
Research on Reverse Engineering of Mechanical Characteristic Parameters of Materials in Collision Simulation
Authors: Fan Zechen 
Published: November 2020

Abstract
The setting of material mechanical characteristic parameters in collision simulation has a great influence on the accuracy of simulation results. Taking the energy absorbing box as the research object, based on the inverse method of energy absorption box test data, finite element simulation, test design and genetic algorithm, the mechanical characteristic parameters of energy absorption box materials are optimized and the initial peak force and the platform force of the force displacement curve obtained from the quasi-static compression test are taken as the evaluation criteria, According to the price standard, the optimized reverse parameters are applied to the simulation model for calculation, and the simulation data are compared with the test data. The results show that the force displacement curve obtained by the simulation model is basically consistent with the overall change trend of the force displacement curve obtained by the test, and the error between the simulation data and the test data is small.
Simulation Analysis of Power Spot Market Based on Evolutionary Game
Authors: Zhao Erdong , Wang Hao , Lin Hongyang , Chen Mingsong 
Published: November 2020

Abstract
As a new round of deepening reform in power system goes on in China, establishing an effective and complete power spot market nationwide based on the construction and operation of eight power spot trials becomes an important task for China. This paper analyzes the competitive strategies and capabilities of different types of power generation enterprises under the operating rules of the electricity spot market by building an evolutionary game model based on an improved genetic algorithm using MATLAB, which provides a valuable scientific basis for the construction and development of the future electricity spot market.
Analysis of Seismic Isolation Effects on a Reverted L-shaped Pier Bridge in High Seismic Intensity Region with Finite Element Simulation
Authors: Wang Longfei 
Published: November 2020

Abstract
The seismic response of urban special-shaped bridges is large, and the consequence of these bridges’ failure is very influential, therefore, the seismic response of this kind of bridges must carefully be calculated and seismic measures of isolation should be used for them. Simulation methods was studied for common used seismic isolation structures such as the rubber bearing, high damping rubber bearing, friction pendulum bearing and block. Four layouts of those seismic structures were set up for an actual reverted L-shaped pier bridge, which were correspondingly four simulation cases. The seismic responses of the bridge were analyzed and comparatively studied in all simulation cases, as a result, the seismic performance and seismic isolation effects of those structures were researched for the bridge, and the isolation design methods were gained. The results show that measures of isolation can reduce largely the seismic response of this kind of special-shaped bridge, high damping rubber bearings have remarkable effect and make the responses among piers more even, and setting reasonably blocks with clearance can make full use of the seismic performance of structures of the bridge.
Research on Equipment Virtual Training Evaluation
Authors: Zhang Baohua , Wei Han , Wang Xiaowei 
Published: November 2020

Abstract
Virtual reality technology was once regarded as the leading force in the development of industrial technology in the future. However, the development of virtual reality technology has encountered a bottleneck period, and its future will attract attention. This article discussed the current technical bottleneck of virtual reality technology, summarized the causes, and analyzed the future development trend of the technology. In view of the shortcomings of the training effect evaluation in the equipment virtual training, the needs of virtual training evaluation are analyzed, an evaluation index system is constructed, and the evaluation system framework is designed. The research results can provide a theoretical reference for perfecting the equipment virtual training.
Mathematical Modelling and Heat Transfer Performance of a TEG for Engine Exhaust Heat Recovery
Authors: He Min , Wang Enhua , Zhao Changlu , Zhang Fujun 
Published: November 2020

Abstract
In recent years, thermoelectric power generation has been investigated widely for waste heat recovery of internal combustion engines. In this paper, the exhaust gas of a heavy-duty diesel engine is used as the heat source. A mathematical model and the simulation program of a large thermoelectric generator(TEG) are established. Using the MATLAB software, the trends of the TEG working parameters in the flow direction are analysed. The flow rate and the temperature of the cold sources, the engine speed and load, and the fin structure parameters of the tube-fin heat exchanger are studied. The results show that the error between the simulated output power and the experimental one is within 11%. A higher engine load rate and a lower coolant temperature are conducive to improving the output power and the conversion efficiency of the TEG. Optimizing the fin spacing and fin height is helpful to improve the heat transfer performance of the heat exchanger and increase the thermoelectric conversion efficiency.
Bootstrap Approximating the Mean of Long Memory Time Series
Authors: Peng Muci , Chen Zhanshou , He Mingcan 
Published: November 2020

Abstract
This paper evaluated the finite sample performances of three bootstrap methods, sieve AR bootstrap (SARB), fractional differencing sieve bootstrap (FDSB) and fractional differencing block bootstrap (FDBB), in approximating the mean of long memory time series. Extensive simulations show that the FDBB method has more stable approximate results in most cases and can more accurately approximate the mean distribution of long memory time series than the other two methods.
EMD and Singular Value Difference Spectrum Based Bearing Fault Characteristics Extraction
Authors: Li Hui , Qi Yang 
Published: November 2020

Abstract
Aiming at extracting rolling bearing defect characteristic effectively under strong background noise, a defect diagnosis technique based on empirical mode decomposition (EMD) and singular value difference spectrum is put forward. Firstly, the non-stationary original bearing vibration experimental data is decomposed into several intrinsic mode functions (IMFs) using EMD technique to eliminate the noise influence. Secondly, the effective intrinsic mode functions are selected by using correlation functions to reconstruct the bearing transient vibration signal. Thirdly, the singular value decomposition of the reconstructed signal is carried out to calculate the singular value difference spectrum (SVDS), and the principal components are selected according to the SVDS. Finally, the envelope spectrum of the reconstructed principal components data is calculated, and rolling bearing defect characteristic is picked up according to the envelope spectrum technique. The results of the experiment exhibit that the proposed technique can be effectively applied to rolling bearing defect characteristics extraction.
Strength Degradation and Life Calculation of Parts under Complex Loads
Authors: Zhang Lei , Feng Guang , Hu Zhen 
Published: November 2020

Abstract
For components, the strength will decrease under the action of multiple loads. In this paper, based on the equivalent relationship of the load, a strength degradation model of the part under multi-stage load is established. This model solves the problem of calculating the remaining life of the part after multiple loads, and can guide the replacement or maintenance of the part during use.
Chinese Dialect Recognition Using X-vector with Multi-task Learning
Authors: Yang Jingzhe , Yu Tongrui 
Published: November 2020

Abstract
Speech recognition is often hard for language in countries with diverse accents, like Mandarin. However, the recognition of different dialects may help to improve the later speech recognition. In this paper, we conduct some experiments on a ten-dialect recognition task. We improve the system with different methods, like x-vector and multi-task learning with phone recognition. Finally, with the combination of the methods, we improve the accuracy of baseline model from 76.48% to 88.25%, where the relative improvement is 15%.
A Review of Disorder Voice Processing Toward to Applications
Authors: Xu Wenhua , Chen Runxuan , Chen Xiaobo 
Published: November 2020

Abstract
Disorder voice processing has great potential to provide convenient, efficient and lowcost applications in medical diagnosis and treatment. For the purpose of a systematic summary of the research progress, this paper introduces it in three terms of research objects, acoustic parameters and features selection, and acoustic model and classification algorithms. It concludes that the appropriate feature selection, feature hybrid and feature offset, integrate with the deep learning frames are the future directions in disorder voice processing.
A Webpage Segmentation Method Based on Node Information Entropy of DOM Tree
Authors: Zhang Shengnan , Wu Jiawei , Yang Kun 
Published: November 2020

Abstract
Aiming at the problems of DOM tree-based webpage segmentation methods in rationality of segmentation results, efficiency, and relying on auxiliary means, in this paper, we propose a new method based on node information entropy of the DOM tree. First, it classified webpage tags and only processed tags that affected the structure of pages. Second, comprehensively considering the content features and the structure features of DOM tree nodes, it calculated information entropy of nodes and maximum text density of subnodes, and based on them, determined whether a node was an independent page block. Finally, this method did node fusion to get the segmentation results. Segmentation tests of multiple web pages with different structures show that the proposed method can accurately and quickly segment the content of web pages.
An Efficient Method for Density Projection Field Solution Based on Finite Element Method
Authors: Zhang Zhengyu , Zhu Fushun , Zhou Run , Chen Qinmei , Yan Hua 
Published: November 2020

Abstract
In the wind tunnel flow field, the relationship between the density projection field, caused by disturbance, and the offset angle of light meets the Poisson equation. However, the source term of the Poisson equation is composed of a series of measured offset angles, which makes it can not be solved effectively by the existing methods. On the basis of the finite element method (FME), we established the fitting formula between the offset angles in the source terms and their corresponding coordinates by employing the Genetic algorithms and back-propagation (GA-BP) neural network. Meanwhile, when the element load vectors were solved, the double integral expression of the entire triangle element prediction was approximately replaced by the constant expression of the triangle vertex element prediction. Simulation experiments demonstrate that compared with the traditional interpolation, the neural network can achieve higher fitting precision. And the proposed algorithm greatly improves the operation speed under the same solution error. By applying the proposed algorithm to the real flow field, the obtained features of the density field are similar to those obtained in the real environment. These imply that the proposed method provides a new useful tool for the study of the density projection field.
Development of Partition of Unity Finite Element Method for the Modelling of Acoustic Waves Propagating through Porous Domain
Authors: Yang Mingming , Song Xiao , Breard Cyrille , Chazot Jean-Daniel 
Published: November 2020

Abstract
The numerical simulation of propagating sound fields in two dimensions using Partition of Unity Finite Element Method(PUFEM) technique is implemented in this work. PUFEM is one of the most practical methods developed to alleviate high computational cost of conventional Finite Element Method when we deal with the medium and high frequency problem. The main idea of PUFEM is to expand the finite element approximation space by incorporating a group of wave functions which are solutions of the governing equation into the target problem. With the intention of further accelerating the computational process, an advanced 2D Exact Integration Technique(EIT) for accelerating the computation process of highly oscillating integrals is proposed and the related PUFEM triangular element is created. The performance and practical interest of this new PUFEM element combined with EIT are evaluated for the wave propagation problem where a porous absorber is included.
An FPGA-based Direct Sampling and Digital Processing System for Wideband and Narrowband Radar Signal
Authors: Zhao Yingxiao , You Hongliang , Zhang Yue 
Published: November 2020

Abstract
This paper designs an integrated wideband and narrowband radar signal direct sampling and digital processing system based on FPGA. The system comprises a VPX case, a main board, a direct sampling board, a fiber board. It makes direct sampling of 1.8GHz-3.0GHz echo waves, with 3.2GHz sampling rate. The wideband and narrowband echo waves share the same ADC channel. After ADC sampling, both of wideband and narrowband data are exported to a mix-free digital quadrature demodulation module in FPGA. The narrowband data will be further processed by digital frequency down conversion. The wideband data will be further processed by digital de-chirp operation, with parallel DDS structure and multi-level decimation filters. Data rate of both the wideband and narrowband data after processing is decreased obviously. The designed sampling system cut down the analog radar signal processing operation, and decreases signal distortion. Besides, it integrated the reception, sampling and processing of wideband and narrowband signal, simplified the structure of radar system.
Application of Text Analysis Technology in Aviation Safety Information Analysis
Authors: Liu Junjie , Yan Huijuan , Du Yinlan 
Published: November 2020

Abstract
This research is aimed to obtain potential safety hazards quickly, accurately, and efficiently from a large amount of daily collected aviation safety information, and provide a clear improvement direction for safety risk control. By combing with the text analysis and machine learning, clustered a given type of aviation safety information according to its content is an important basis of mining information effectively. Taken the system failure/jam/fault events collected by Chinese civil aviation in 2017 as a sample. By means of text pre-processing, feature extraction by using logarithmic IF-IDF and k-means method under the environment of python3.6, an automatic clustering model of the sample information is established, and then the visualized results are output based on Multi Dimensional Scale (MDS). The analysis results show that text clustering and visualization can quickly and automatically file information, identify the similarity among sample information, easily lock key information, and provide targeted measures for the next step of risk management and control.
The Organization Model of Big Data Innovation Alliance: A Multi-Case Study from the Perspective of Virtual Clusters
Authors: Li Tianzhu , Wang Xiaomei 
Published: November 2020

Abstract
The Big Data Innovation Alliance can be understood as a cross-industry and cross-region spatial agglomeration phenomenon based on Big Data. From the two aspects of constituent elements and organizational characteristics, the Big Data Innovation Alliance is found to be a learning organization with a flat management structure. A multi-case study method is used to empirically test the virtual cluster characteristics of the big data innovation alliance organization model using four typical cases, and to analyze its generality and specificity based on the research variables. Several policy implications have been obtained for the big data innovation alliance organization model.
Education Reform of Theoretical Mechanics for Civil Engineering in Big Data Era
Authors: Xie Ming , Meng Fanbing , Feng Wei , Ma Shaohua 
Published: November 2020

Abstract
The “Theoretical Mechanics” course is a basic mechanics course for undergraduates majoring in civil engineering. Based on the teaching status of the course, it conforms to the development trend of the era of big data, analyses the necessity of teaching reform and gives corresponding countermeasures. Practice has shown that the teaching reform of the “Theoretical Mechanics” course in the era of big data has greatly increased the enthusiasm of students to learn the course and the quality of teaching Guarantee. It provides an effective guarantee for the cultivation of high-level, high-quality modern scientific and technological engineering talents in the era of big data.