bluuebunny/crossref_metadata_2025_split huggingface dataset:
Improved design and experimental research of cooperative robot’s manipulator
Authors: Wei Leng , Lei Zhang , Xian Zhang 
Published: March 2021

Abstract
With the proposal of the Made in China 2025 plan, robots have been widely used in aerospace and other fields. In recent years, robots have been applied in aviation manufacturing industry in the way of man-machine collaboration. Manipulator, as an important part of cooperative robot, plays an important role in its work. In this paper, a new type of modular underactuated manipulator is designed based on the structural improvement of the underactuated manipulator. The test platform of the modular underactuated manipulator is built to verify the actual grasping ability of the manipulator. Experiments show that the design of manipulator is reasonable and can meet the requirements of grasping work.
Simulation and optimum design of small fan for animal house by CFD
Authors: Liu Zhaoxia , Xiong Yingqing , Chen Yan 
Published: March 2021

Abstract
In order to improve the aerodynamics performance of the fan in animal house, the extractor for animal house (model: 400-4-2) has been taken as the optimization object, and the Computational Fluid Dynamics (CFD) method was used to analyze the airflow nearby the whole extractor. The FreescaX5 3D scanner was used to collect data and reconstruct 3D model of the prototype fan. Then, the prototype fan model was optimized by CFD simulation to investigate the performance and defects of the prototype fan, and thereby to propose the improvement scheme. The simulation results of flow field near the blade showed that the performance of fan was influenced by the impeller numbers, the bending direction and the blade shape. In the numerical simulation, when the wind speed was used as the evaluation standard, the parameters of the optimized fan are as follows, the blade number is 7, the blade bending direction is forward bending, the blade tip angle and root angle is 9.5° and 58.0° respectively, and the blade cross-section shape is streamlined with small airfoil curvature. The air volume of the optimized fan increased by 3.86% when the optimized fan is compared with the prototype fan at the same power.
Review on chaotic weak signal processing
Authors: Wang Meng Tong , Liu Shu Yong , Cai Ying , Li Si Ting 
Published: March 2021

Abstract
Weak fault signal not only refers to the signal with very small amplitude, but also refers to the signal existing in the background of strong noise. Weak signal detection technology is widely used in communication, radar, magnetism, vibration measurement, medicine and other research fields. Based on the essence of chaos, this paper summarizes the research status of chaos at home and abroad, including the basic characteristics of chaos system, the basic characteristics of chaos, the chaotic dynamics model and the discriminant method of chaos. The different methods of chaotic weak fault feature extraction are analyzed, their advantages and disadvantages are pointed out, and the research trend is forecasted
Study on modal dynamic balance method of bearing rotor system
Authors: Zhou Huimin , Wang Zhan 
Published: March 2021

Abstract
In order to make dynamic balance for bearing rotor system with unbalanced vibration, a modal balancing method for bearing rotor system is proposed. The vibration of the rotor is decomposed into multi-order components according to vibration mode, the unbalanced components are balanced step by step, and the correction amount of each unbalance is solved by establishing a modal matrix equation. Through simulation analysis, it can be seen that under different conditions of speed and unbalance, the amplitude of the rotor after dynamic balace is greatly reduced, and the average vibration is reduced by more than 70%. This method can suppress vibration effectively for bearing rotor system and improve running performance of high speed bearing rotor system.
Research on Robotic Measurement Path Planning for Complex Surface Workpieces
Authors: Mei Zhen , Qi Lizhe , Sun Yunquan , Xu Min 
Published: March 2021

Abstract
Combined with measurement efficiency, measurement accuracy and no interference in the measurement process, this paper proposes a path planning method for a measuring robot for complex surfaces such as blisk. The position planning of robot measurement path is realized based on the surface chord height difference, and the attitude planning of robot measurement path is realized based on the single measured point measurement attitude space(SMPMAS). Finally, the effectiveness of the proposed method is verified by experiments.
Effect of deformation parameters on microstructure of martensitic stainless steel during static recrystallization
Authors: Ren Facai , Si Jun , Xu Jinsha 
Published: March 2021

Abstract
In this paper, the static recrystallization behavior of X20Cr13 martensitic stainless steel was studied based on the hot compression test. The experimental results show that when the strain of the first pass is less than the critical strain of dynamic recrystallization, the main static softening mechanism is static recrystallization. The effects of prestrain, initial austenite grain size, deformation temperature and strain rate on the microstructure during static recrystallization were analyzed in detail.
A novel method for bearing lubrication enhancement via the inner ring groove structure
Authors: Ge Linfeng , Yan Ke , Wang Chao , Zhu Yongsheng , Hong Jun 
Published: March 2021

Abstract
As the bearing rotation speed increases, the efficiency of the jet lubrication is drastically reduced due to the air curtain effect inside bearing cavity. Regarding this, by adding groove structures to the non-contact area of bearing inner ring surface, a novel method which can guide more oil flowing into the bearing raceway was proposed. By numerical simulation, the flow behavior of oil on the bearing inner ring surface was investigated. The results indicate that, compared with the traditional structure, the axial oil flow on grooved inner ring surface was enhanced, and more oil accumulated in the key lubrication area inside bearing cavity. Finally, by lubrication performance experiments, it was proved that the bearing lubrication performance had been improved by adding groove structures on its inner ring surface.
Rolling Bearing Fault Diagnosis Method Based on Improved Deep Belief Network
Authors: Hu Bingbing , Tang Jiahui , Wu Jimei , Liu Jie 
Published: March 2021

Abstract
The issue of classification accuracy for the fault diagnosis model has received considerable critical attention. In this study, an improved deep belief network was developed and applied to fault diagnosis of rolling bearings. Firstly, the forward training part composed of restricted Boltzmann machines (RBMs) is employed to learn the hidden features of vibration data. Secondly, the samples are synthetized by the reverse generation part according to the weight sharing. The noise time-shift layer can significantly enhance the generalization performance of the model, and the synthesized samples can be utilized to supplement the original dataset to enhance the learning efficiency. Experimental results prove that the improved DBN can manifest remarkable superiority in fault diagnosis against other methods.
Numerical study on the effect of CaCO3 ratio on the mechanical properties of CaCO3/PVC composites
Authors: Luo Shijun , Pan Sining 
Published: March 2021

Abstract
The effect of CaCO3 (calcium carbonate) ratio on the mechanical properties of CaCO3/PVC (polyvinyl chloride) composites was studied by numerical simulation in this paper. The representative volume units of CaCO3/PVC Composites with different CaCO3 ratios were established by using the random dropping method. The stress-strain variation of CaCO3/PVC composites with different CaCO3 ratios under tensile or compressive loads was calculated, and the influence of CaCO3 ratio on the stiffness of CaCO3/PVC composites was discussed. Considering the comprehensive effect of calcium carbonate ratio on stiffness and stress-strain, the best ratio of calcium carbonate in PVC is 25%.
Automatic and rapid calibration method for temperature coefficient of fiber grating temperature sensor
Authors: Lu Meng , Zhang Nan , Liu Pan , He Jianjun , Zhou Yabin , Zhu Pingyu 
Published: March 2021

Abstract
Bare fiber Bragg grating (FBG) is packaged by thermal conductive materials and to be used as a temperature sensor. In the oil bath calibration of the temperature coefficient of the FBG temperature, it is difficult to accurately synchronize the single point temperature measurement and the simultaneously record FBG central wavelength using different devices. An automatic, fast and high precision calibration method for temperature coefficient of FBG temperature sensor is proposed. The experimental results show that the temperature coefficient obtained by the proposed method can accurately measure the temperature, and the calibration process is fast and avoids the error caused by manual recording and formula derivation. The system is suitable for rapid calibration of mass-produced FBG sensors.
Stability Test on Power Supply to the Xenon Lamp of Solar Simulator
Authors: Liu Gaotong , Ning Juan , Gu Zhifei , Wang Zeyang 
Published: March 2021

Abstract
In this paper, the stability of the electrical control system structure of the typical solar simulator system is studied. Volt-ampere characteristic tests, light-on tests and system-level irradiance stability tests after light-on of xenon lamps with three power supplies were carried out using the solar simulator (KFTA). The solar simulator test is carried out on the current three mainstream input power supplies respectively. The stability test target of the electrical control structure of the solar simulator system is completed, and the irradiation instability is realized which is better than± 1%.
Electro-hydraulic Composite Emergency Braking System Based on Frequency Reconstruction Control
Authors: Pan Zheng , Yang Xiao , Jing Hui , Li Boyuan , Wang Rongrong 
Published: March 2021

Abstract
For four-wheel independently driven (FWID) electric vehicle (EV), in order to guarantee braking reliability, hydraulic braking system and motor anti-drag braking system are usually used at the same time. In this paper, a novel electro-hydraulic composite braking control strategy is given to solve the distribution problem of braking torque between hydraulic braking torque and motor anti-drag braking torque. The high-frequency part of the desired braking torque is distributed to the motor brake through a high-pass filter so as to fully utilize the fast response characteristics of the motor. Meanwhile, the low-frequency part of the desired braking torque is distributed to the hydraulic brake through a low-pass filter so as to reduce the load of the motor. The cost functions are designed to determine the cut-off frequency of low-pass and high-pass filters. Through the joint simulation of Matlab/Simulink and TruckSim, the braking effect of the electro-hydraulic composite braking is better than that of pure hydraulic braking with no motor to modulate the braking torque.
Guidelines for the computational domain size on an urban-scale VAWT
Authors: Mo Qiuyun , Guan Huisen , He Shengwen , Liu Yanyan , Guo Rongbin 
Published: March 2021

Abstract
Focusing on the H-type vertical axis wind turbines (VAWTs) widely used in urban, the SST k - ω turbulence model was selected to establish a two-dimensional Computational Fluid Dynamics (CFD) model, the moment coefficient (Cm), and power coefficient (Cp) was taken as the evaluation indicators. The CFD model was used in different domain sizes. The simulation results under the sizes were used to investigate the effect of the computational domain size on the numerical simulation results of the aerodynamic performance of the VAWT. Furthermore, a distance from the turbine center to the domain inlet and outlet of 10D (D: diameter of the turbine) each, a domain width of 10D and a diameter of the rotating core of 1.5D are found to be safe choices to minimize the effects of blockage and uncertainty in the boundary conditions on the results. It provides a reference for the selection of the domain size when CFD simulation is implemented in a vertical axis turbine to get its prediction of the performance in the future accurately.
Research on Topic Mining of Medical Surgical Mask Reviews Sold on E-commerce Platform
Authors: Qidi Jiao 
Published: March 2021

Abstract
Since the outbreak of the epidemic in 2020, the development potential of pharmaceutical e-commerce is huge. Mining and studying the review information of e-commerce platform to improve the dimensions of products is an important way for the healthy development of medical e-commerce. In this paper, the review information of medical surgical mask, a hot sales product of medical e-commerce, is extracted. TF-IDF algorithm, dependency syntax and other models are used to mine the topic information contained in the review, and then python is used to analyze the emotional polarity of the review, and finally the emotional assignments of the main review topics are obtained. The results show that consumers have higher satisfaction with the appearance of goods, but lower satisfaction with packaging. On the basis of the research results, corresponding reference suggestions are proposed for medical e-commerce.
Singularity Avoidance Algorithm Based on Bounded Deviation Path Correction Method
Authors: Wang Nei , Li Bin , Lai Qiwei , Xiang Chao , Wu Di 
Published: March 2021

Abstract
Focused on the abnormal problems of path planning when a custom 6-DOF robot goes passed singular points, this paper makes descriptions based on kinematic analysis and dynamic analysis. It is pointed out that linear interpolation should not be simply abandoned but choose joint motion when singularity problems encounters. Instead, this paper suggests a singularity algorithm to modify the interpolated point sequence in the singular interval after a preliminary path planning of the interpolated point sequences, of which the modification method is called “Bounded Deviation Path Correction Method”(BDPC) in this paper. This algorithm can ensure both the accuracy of the end position and the attitude, and finally realizes the effective and reliable motion planning of the manipulator through the singular interval.
Seeking sustainable pathways for fostering agricultural transformation in peninsular India
Authors: Anantha K H , Garg Kaushal K , Petrie Cameron A , Dixit Sreenath 
Published: March 2021

Abstract
Sizable populations in developing countries in Asia and Africa live in dryland ecosystems, and agriculture in these areas faces major challenges including water scarcity, land degradation, poor infrastructure and insufficient access to markets. Natural resource management (NRM) interventions offer an important path to sustainable agricultural practices through increasing resource use efficiency, but true efficacy will only be achievable if these initiatives can be scaled up. This paper explores the impact of farm-scale NRM interventions undertaken in the state of Karnataka, India, between 2005 and 2020. NRM technologies such as soil health management, resource use efficiency and improved crop cultivars were demonstrated in more than 50 000 farmers’ fields. Participatory demonstrations and capacity building initiatives were effectively used to co-create innovations for rapid and wide dissemination, and NRM practices involving the soil-nutrient-crop-water continuum were the subject of large-scale demonstrations. The demonstration fields were divided into treated and control fields, and efforts were made to measure cost of cultivation, irrigation application and crop yield. The soil health management interventions helped to enhance crop yield by 10%–60% over the control plots. Technologies specific to resource conservation have helped to conserve soil moisture, reduce irrigation requirement by 50–300 mm and reduce the cost of cultivation by US$ 150 ha−1. Improved cereal, pulse and oil seed cultivars increased crop yield minimum by 15%. Although these results have a large variability, they consistently showed the effectiveness of integrating NRM practices with crop demonstrations. These results are ideal for sensitizing stakeholders and policymakers to the benefits of adopting science-based approaches to NRM interventions in order to bridge yield gaps and address land degradation, food insecurity and poverty in dryland regions in South Asia and globally.
Influence of Pacific Decadal Oscillation on global precipitation extremes
Authors: Wei Wenguang , Yan Zhongwei , Li Zhen 
Published: March 2021

Abstract
While the influence of the Pacific Decadal Oscillation (PDO) on precipitation has been extensively studied, its influence on precipitation extremes remains not well-known. Based on a series of generalized extreme value modeling experiments, this paper demonstrates some distinct regional patterns of the PDO’s influence on precipitation extremes worldwide. In eastern China, the well-known ‘southern flood (drought) and northern drought (flood)’ pattern in summer corresponds well to the positive (negative) phase of the PDO. In Australia, there tends to be a tripole pattern, with positive correlation between precipitation extremes and the PDO in the central region, and negative correlation in both eastern and western Australia. The precipitation extremes in northwestern Europe and western Russia roughly hold positive correlation with the PDO. These regional patterns of the PDO’s influences are explained via comparative analyses of the atmospheric circulation conditions between cold and warm PDO phases. Certain precipitation extremes tend to be missed or happen more than once during different phases of the PDO at more than 2/3 of stations in a typical region. The cold phase tends to exert more consistent influences than the warm phase in these typical regions. These findings not only indicate different risks of extreme precipitation for the typical regions during different phases of the PDO, but also have important implications for the near-term projection of variable regional climate extremes under global warming.
Economic Analysis of Centralized Energy Storage and Impact on NEM
Authors: Meng Yunfan 
Published: March 2021

Abstract
Energy storage has a broad prospect in the future electricity market. Hornsdale Power Reserve (HPR), the largest battery energy storage system in Australia, was selected as the research case to evaluate the impact of energy storage systems on the National Electricity Market (NEM) operation and its economic benefits. The analysis of HPR includes its performance in the NEM and FCAS markets, its profitability, and its impact on the different markets, thus reflecting the feasibility and superiority of the energy storage system. The results show that energy storage is active in the FCAS market. By comparing the FCAS regulation performance of HPR and the conventional OCGT in South Australia and researching the response to sudden frequency changes, it is found that energy storage has accuracy, speed in regulating frequency, and maintaining system frequency stability. The economic analysis results show that the primary revenue of energy storage comes from the FCAS market. Taking HPR as an example, more than 70% of its electricity sales revenue comes from the FCAS market, especially the Contingency FCAS market. Comparing HPR with wind farms and PV farms of the same power size (100MW), its high IRR, short payback period, and relatively high NPV demonstrate the investment potential of energy storage systems. Optimizing HPR’s energy storage configuration achieves the maximum benefit when its scale expands by 50% (150MW). There will still be huge profits when grown by 100% (200MW), proving energy storage systems’ development potential. Using the economic sensitivity analysis of HPR to find ways to improve the energy storage system’s economic benefits, it can be seen that increasing the participation rate of the FCAS market and improving the technical level of the battery are the effective methods.
Application of Automation Technology in Coal Preparation Technology
Authors: Wei Xiaolong 
Published: March 2021

Abstract
In order to improve the quality of the coal preparation process and realize the automatic control of the coal preparation process, this article takes an intelligent transformation project of a coal preparation plant as an example to analyze the application of automation technology in the coal preparation process. The article introduces the actual situation of a coal preparation plant and the specific application of automation technology, analyzes the research ideas of the coal preparation plant’s automation technology, the automatic transformation, installation and commissioning of the coal preparation process equipment, and analyzes its process test results. It is hoped that this analysis can be helpful to the good application and development of automation technology in coal preparation technology.
Research on Safety Evaluation Technology of Portal Cranes Based On Analytic Hierarchy Process (AHP) Theory
Authors: Li Qin , Ren Li-Xin , Li Guo-Feng , Tong Yao-Ting 
Published: March 2021

Abstract
This paper introduces the present situation of portal crane and the shortcomings of the current standard system, and puts forward a feasible safety evaluation method. Based on the theory of Analytic Hierarchy Process ((AHP)), the safety assessment method of portal crane is studied, and a more perfect method is put forward. The evaluation value D of equipment safety performance obtained by this method can specifically and clearly express the actual status and risk level of equipment.
An Empirical Analysis of the Impact of Government Subsidies on the Innovation of New Energy Automobile Companies before and after the subsidy policy declines
Authors: Lu Ye , Liu Qin , dan Han Ming 
Published: March 2021

Abstract
This article uses 2016 as the time node, divides 2009-2019 into two phases before and after the subsidy policy declines. It uses the panel data of 15 listed companies whose main business of new energy is the production and sales of new energy vehicles. Regression model and panel regression model respectively analyze the relationship between government subsidies and the innovation performance of new energy automobile companies.
A Wind Speed Prediction Method Based on Improved Empirical Mode Decomposition and Support Vector Machine
Authors: Wang Shibo , Guo Yongchao , Wang Yanzhuo , Li Qinghua , Wang Nan , Sun Shumin , Cheng Yan , Yu Peng 
Published: March 2021

Abstract
Based on the complete ensemble empirical mode decomposition with adaptive noise (CEEMDAN) and bat algorithm (BA) to optimize the support vector machine, this paper proposed a combined model for short-term wind speed forecasting to predict the wind speed more accurately. Firstly, CEEMDAN was used to decompose the original wind speed time series into a series of subsequences with different frequencies. Secondly, the decomposed subsequences were forecasted by combined model of BA-SVM. Finally, the wind speed forecasting results was achieved by superposing each predicted subsequence. The simulation results suggest that the model improves the prediction accuracy and reduces the error.