bluuebunny/crossref_metadata_2025_split huggingface dataset:
Time series and stochastic differential equations as a tool to model the volatility of an asset
Authors: Ramírez C A V , González J R , Correa G 
Published: June 2021

Abstract
In the problem of estimating the prices of electricity markets, different forecast models have been proposed for the short term, among the most outstanding are the works by Francisco Nogales, which uses autoregressive integrated moving average methodology to analyses time series in the California market. Peninsular Spain. Nogales and Contreras use time series models applied to the markets of California and Spain, the applied series were carried out to estimate the hourly price of the following day using two methodologies, the first a dynamic regression and the second transfer function models. In he proposes a prediction based on Autoregressive conditional heteroscedasticity models generalized conditional autoregressive heteroscedasticity Rabbit use the wavelet transform to decompose the data series, then applying an autoregressive integrated moving average model to the transformed series, taking advantage of the existing advantages in the domain of the frequency. The techniques have a high correlation with problems of physics which can be approached in a similar way, we must highlight the fact of using stochastic differential equations which are modern techniques in mathematics and physics.
Design of a proportional integral derivative controller of temperature regulated for a nursery
Authors: Perez-Torrado W , Espinel-Blanco E , Velásquez-Pérez T 
Published: June 2021

Abstract
This article describes the design and simulation of a proportional integral derivative PID controller that operates a proportional control valve to allow the flow of hot water to the radiant floor of a pig farm to maintain the required temperature. In the development of the project physical and mathematical concepts are required for controlling, the temperature oscillations in the range of 25 °C to 35 °C and the heat flux through the radiating surface of the floor, as well as analyzing the parameters involved for the development of the control system; In the control system design the characteristics and parameters involved in the pigs rearing by means of corral were identified; later the thermal analysis of the heating system integrated into the radiant floor that supplies heat to maintain the temperature was carried out, then the response of the temperature control system was simulated in the Scilab software and finally, the programming of the proportional integrative control was carried out. The design considers using gas generated in a biodigester to transfer thermal energy to the heating water that circulates through the floor, transferring heat to the brood module until it reaches and maintains the desired temperature using a control system that involves a proportional valve program in Arduino. The entire system was simulated by means of software including the gas and water circuits according to the heat transfer flow required to maintain the controlled temperature inside the module. The developed design allows controlling the heat flow to maintain the required temperature, stabilizing the process in 20 minutes.
Estimation of missing data in a geophysical series of precipitation
Authors: Gallardo Pérez H J , Vergel Ortega M , Rojas Suárez J P 
Published: June 2021

Abstract
The analysis of dynamic systems is a topic of great interest in the basic sciences since it allows direct inference of the behavior of different systems. The study of physical phenomena provides large databases that, if recorded at regular time intervals, constitute time series. However, time series of geophysical data in many cases present missing data and their estimation requires the application of valid methods that allow estimating reliable information to complete the series since some analysis methods require these series to be complete. Two methods are used in this article to estimate the missing values of the precipitation series in the city of San José de Cúcuta, Colombia, the first one consists of considering the univariate data series and applying an adjustment of the sequential conditional expectation method of forecasting with restrictions, the second one refers to analyze the data series of a nearby station and through multivariate methods establish the cointegration between the series, and then use this as a basis for estimating the missing data in the analysis series. The two methods are recursive, a first estimation of the model is made ignoring the missing data, an initial estimation of the missing data is made, then a new estimation of the model parameters and a new estimation of the missing data is made, the algorithm continues running with the new values replacing the values estimated in the previous phase until the difference of the estimated values between successive iterations is less than a value fixed beforehand. Finally, a comparison is made between the estimates made by the two methods.
Distribution and Influence of Optimal Structural Parameters to Low-frequency Sound Absorption Property of the Microperforated Panel Absorber
Authors: Yang Xiaocui , Zhu Nannan , Zhao Rongxing 
Published: June 2021

Abstract
Noise pollution is a global problem, no matter in developed or developing countries, which makes the noise reduction one research focus all over the world. microperforated panel (MPP) absorber is supposed as a potential and practical candidate for effective noise reduction, particularly in the urban area. Influence of the optimal structural parameters to low-frequency sound absorption performance of the MPP absorber are studied in this research. The theoretical sound absorption model provides the foundation for the further analysis, and the cuckoo search algorithm is treated as the technique support. Influences of the optimal structural parameters for thin/normal/thick MPP absorbers are studied by the combination of theoretical modeling and cuckoo search optimization with the total thickness of the MPP absorber ranging from 10 mm to 60 mm with the interval of 10 mm, from which it can be concluded that the major influent factor is total thickness of the MPP absorber. For a given total thickness of the MPP absorber, no matter what thickness of the panel is, it can always achieve appropriate structural parameters by optimization to obtain similar best sound absorption performance, which will be favorable to design and develop practical MPP absorbers.
Research of parameter optimization of double trailing arm suspension mechanism for integrated wheel side deceleration electric drive system
Authors: Xinbo Chen , Yanjia Lu , Naiwen Xu , Xiang Xu 
Published: June 2021

Abstract
This paper put forward the solution of the wheel side deceleration electric drive system of double trailing arm suspension, through the combination of the trailing arm suspension and the electric drive system of wheel side deceleration. And the geometric mathematical model of the double trailing arm suspension based on the four-bar mechanism was established. MATLAB executable file and the program interface was compiled, which quickly located the motor center layout position under the given conditions. When the wheel jumps, the center distance between the motor and the wheel remains unchanged. According to the reasonable parameters of the trailing arm structure provided by MATLAB, CATIA three-dimensional modeling was carried out, and ADAMS was imported for kinematics simulation, which verified the feasibility of the design scheme of the double trailing arm suspension and the MATLAB program.
Research on Dynamic Resource Allocation and Decision-making Model of Equipment Independent Maintenance
Authors: Wei Xia , Quan Shi , Shi zhuang Yin , song Ai Yan , Gang Qi 
Published: June 2021

Abstract
This paper defines the relevant concepts and research objects of equipment independent maintenance, and defines the basic framework of resource allocation and decision-making model of independent maintenance. The solution method and key technology of resource allocation and decision model of equipment independent maintenance under dynamic demand condition are studied. Finally, the model is solved and the results are compared and analyzed with an example, which provides a meta-heuristic intelligent optimization algorithm that does not depend on the problem itself, and provides a thought and reference for the independent maintenance of equipment.
A novel method for constructing a dynamics model with the flexible characteristics
Authors: Li Yujie , Zhang Ming , Zhu Yu 
Published: June 2021

Abstract
An accurate dynamics model is an essential part of ensuring the effectiveness of constructing flexible dynamical systems in the simulation. Finite element method is an effective method to build a flexible structural dynamics model, but this method will cause the model to have too many orders to increase the difficulty in the simulation. The reduction method based on the finite element principle is an effective method to build a streamlined model. This paper proposes a method that combines the critical modes of the structure and the reduction method based on the finite element model to construct an effective flexible dynamics model. Firstly, the determination of primary and secondary degrees of freedom is provided by the judgment of critical modes. Then, an adequate simulation model and an experimental setup are established respectively based on a flexible structure as an example. Finally, through the simulation comparison, the reduction model and the full-order model keep the same simulation results, but the simulation time consumed by the latter is 13 times of the former. In terms of experimental and simulation comparison, the simulation and the experimental results have the same transient oscillation frequency, and the steady-state angle deviation is 2 mrad.
Effect of geometric cavity shape and diameter on mechanical properties of water lubricated hydrostatic stern bearing
Authors: Zhuo Liu , Chang-geng Shuai , Xue Yang 
Published: June 2021

Abstract
In order to improve the working condition of low speed, the stern bearing friction caused by poor lubrication of abnormal vibration and noise problem, this paper starts from the influence of problem, takes the circular, elliptical, square, I-shaped and triangular cavity as the research object, establishes the water lubricated stern bearing model, and carries on the mechanical analysis of the model by using ANSYS/Workbench; and on this basis, study the effect of the diameter of the cavity on the mechanical properties of stern bearing. The results show that the displacement, strain and stress of circular cavity bearing are better than other geometric cavity bearings. Among them, the mechanical properties of 3∼4mm have a better performance.
Heat Modeling and Experiment of Micro-drilling with Multi-parameter Influence
Authors: Wu Zhenhe , Zhang Faping , Feng Kuikui 
Published: June 2021

Abstract
Cutting temperature is essential to improve machining technology in micro drilling of hard material. As the unreasonable temperature distribution will increase the complexity of tool-workpiece surface contact, affect the machining quality of tool and the surface integrity of hole wall. In this paper, the cutting process model is combined with the analytical temperature rise model based on time to study the change rule of surface contact conditions. The 40Cr sample was used to carry out drilling experiments. The results show that the high feed micro drill tool is prone to structural differences at high temperature, large area size effect. It makes the contact conditions change significantly, and the heat distribution of system changes, which affects the stability of cutting.
Measurement and Analysis of Acoustic Absorbing Coefficient of High-porosity Nickel Foam with Different Thickness
Authors: Wang Enshuai , Shen Xinmin , Duan Haiqin , Yang Fei , Zhang Xiaonan 
Published: June 2021

Abstract
The noise problems have gradually become a major problem that affect the health of personnel and hinders industrial progress. Metal foam is one kind of the porous media, which could be applied as effective acoustic absorbing materials. In this study, an uncompressed pure material nickel foam with the various thickness of 20, 40, 60, 80, 100mm was used for acoustic experiments under the condition of the test signal wave frequency range of 100-2000Hz. The corresponding acoustic absorbing coefficient was measured by AWA6128A standing wave tube tester, and the corresponding analysis was carried out. It proves that nickel foam has high acoustic absorbing coefficient at high frequencies, and the parameters of nickel foam can be changed to meet the requirement of different acoustic absorbing properties.
Model-based Integration and Verification of Air-borne System
Authors: Chen Wen 
Published: June 2021

Abstract
With the development of aerospace science and technology, the functions of airborne systems are integrated into a smaller chip. To integrate and verify the air-borne system design, Model-Based System Engineering(MBSE) is a kind of numerous methods. To effectively support the design and development of complicated air-borne system. The advantages of MBSE applying to the integration and verification of air-borne system are analysied, and some advises are given.
Strength analysis of motor shaft based on ABAQUS
Authors: Liu Yucong , Feng Huihua 
Published: June 2021

Abstract
Focusing on the situation of the motor shaft breaking in the work, using finite element software ABAQUS, considering the coupling effect of interference fit, working load, and eccentric load, the strength analysis of the motor shaft is carried out. The results show that the interference fit will cause the stress concentration of the motor shaft, and the stress safety factor of the motor shaft under the working load can meet the use demand, while the eccentric load will significantly change the stress distribution of the motor shaft and reduce its safety factor. The variation of assembly interference and eccentric load will significantly affect the stress distribution of motor shaft.
Thermal-mechanical Coupling Analysis of Rear Wheel Brake of Sightseeing Vehicle Based on Workbench
Authors: Qiu Maochang , Yao Jia , Zhong Tuyi , Wu Qihan 
Published: June 2021

Abstract
Taking the rear wheel brake of a certain brand of sightseeing vehicle as an example, floating caliper disc brakes and leading trailing shoe brake were simulated and compared for determining rear wheel brake types. The simplified model is established by UG software, imported into Workbench for thermal-mechanical coupling analysis under 10 braking conditions. The results show that the two brakes can meet the requirements of the vehicle, the former has better performance, and the latter has lower cost.
Welding procedure qualification of small diameter thin-walled titanium pipes
Authors: Chengjun Jiang , Wei Wang , Qian Li 
Published: June 2021

Abstract
The small diameter thin-walled TA2 titanium tubes are used in a technical renovation project. In order to ensure the performance of the product, the automatic GTAW welding process is adopted by analyzing the weldability of TA2 titanium tubes. The process qualification tests such as appearance inspection, nondestructive testing, mechanical properties and metallographic examination are carried out. The test results show that the welding joint with good performance can be obtained by reasonable welding procedure parameters and strict gas protection measures. The welding procedure and related measures can be used as a reference for manufacture and installation of titanium pipes.
Optimization of garbage dumping mechanism of intelligent sanitation vehicle based on particle swarm algorithm
Authors: Li Yan , Chen Jiawei , Xu Xiang , Lin Zhongyan , Chen Xinbo 
Published: June 2021

Abstract
Aiming at the requirements of low power consumption and light weight of the intelligent garbage collection and transportation equipment of sanitation vehicles, this paper proposes an optimization method based on the particle swarm algorithm. In this paper, the kinematic equation and dynamic equation of the mechanical claw in the dumping action are derived by using the complex interpolation approach. The optimization objectives are the minimum maximum power, the minimum average power, the minimum maximum mutation of the instantaneous driving force and the minimum time-consuming of the dumping action. The garbage dumping angle is selected as constraints, and the arc radius of the dumping track, the centre distance of the mechanical claw’s groove wheels and the time-consuming of the dumping action are optimized. The optimization results show that the optimization objectives have been well optimized except for the increased time-consuming dumping action. And the driving force should act on the axis of the lower groove wheels.
Modeling of detection techniques for FMCW lidar using OptiSystem
Authors: Qingchun Huang , Kaida Cai , Jing Xiao 
Published: June 2021

Abstract
In this paper, we investigated the frequency modulation continuous wave (FMCW) lidar rang measurement principle, then designed a simulated distance measurement scheme and building the model. Using the OptiSystem system modeling simulation, the relationship between frequency modulation (FM) bandwidth, FM time and rang measurement accuracy is investigated, and the effect of different sweep parameters on the accuracy of the final rang measurement results is discussed in the time and frequency domains. The simulation tests the delay of the target at 30, 60 and 90 meters respectively, and the distance is derived by beating the frequency of the optical echo signal with the local oscillation optical signal and calculating the beat frequency.
The Application and challenge of Digital Twin technology in Ship equipment
Authors: Wen-hao WU , Guo-bing Chen , Zi-chun Yang 
Published: June 2021

Abstract
Digital twin technology has been widely developed and very active in many areas of intelligent manufacturing in recent years. Due to the complexity of ship equipment, the impact of variable loads and the high salt spray environment of the ocean, performance degradation was rapid and failures occurred frequently. Its full life cycle operation and maintenance was the main problem that restricts its performance and affects the ship’s ability to carry out its mission. Based on the analysis of the development status of digital twin technology and its application in the full life cycle of equipment, this paper proposes a framework for intelligent operation and maintenance of marine devices based on digital twin and discusses the challenges faced by digital twin technology in the application of marine equipment, so as to provide reference and reference for accelerating the role of digital twin technology as a combat multiplier in marine equipment.
Optimization Analysis of Vibration Characteristics for Precision Positioning Stage
Authors: Li Chen , Li Wanguo 
Published: June 2021

Abstract
As the core of semiconductor equipment, the vibration of precision positioning stage has great influence on its comprehensive performance. The research object of this paper is a high-precision positioning stage for chip detection. The precision positioning stage is driven by linear motors and supported by rolling linear guides. During the movement, vibration will be generated due to the influence of cable disturbance force and motor thrust harmonics. Based on Newton mechanics, the dynamic formula group of the motion table is established, and the reasons for the vibration of each degree are analyzed. Based on the geometric nonlinear theory, the cable model is established with the help of finite element software, and the influence of installation dimensions on the dynamic change of the cable assembly is analyzed. The motor thrust formula is established based on the equivalent magnetizing current method, the characteristics and influencing factors of the thrust harmonics are analyzed, and the method to suppress the thrust harmonics from the source is sought. In this paper, the vibration source characteristics of the stage are obtained through theory and simulation, which lays a foundation for the subsequent use of control strategy compensation.
Design of Intelligent Garage Control System Based on Internet of Things
Authors: Lan Cao , Yingang Shen , YueChen Chang 
Published: June 2021

Abstract
According to comb tooth mufti-layer parking equipment control problem, a control system based on Internet of things the garage is designed. The control system mainly includes two parts, which are the garage terminal and the mobile phone terminal. The garage terminal used arduino microcontroller as the controlling core, it used the Ethernet module to access the internet of things, it can collect parking information, park and fetch the car to the garage, etc. The mobile APP terminal completes human-computer interaction with users. After the design of the control system is completed, the function test is carried out. The test results show that the app to complete the garage booking, parking, pick-up and other functions. It can meet the requires of the intelligent garage, which has a certain reference value for the design of modern intelligent garage system.
Exploration of Design Methods Based on Bionic Functional Modules
Authors: Lv Bing , Xue Zhenpeng , Wei Hao , Li Yantao 
Published: June 2021

Abstract
Triz theory is the knowledge of heuristic methods to solve invention problems. The bionic model also has the effect of inspiring and solving invention problems. Both of them have been widely used in the engineering field. By consulting the existing bionic literature, analyzing the corresponding engineering problems to be solved, corresponding to the Triz conflict matrix, filling the bioengineering model into the conflict matrix, and establishing a conflict problem resolution matrix based on the bionic functional module, starting from the perspective of bionics a solution to the problem of engineering conflicts. In future design work, designers can quickly locate bionic objects, inspire design thinking, and greatly shorten the design cycle.
A method to determine the topology of custom torsional elastic element for the lightweight rotary series elastic actuator
Authors: Zhou Min , Wang Sun’an 
Published: June 2021

Abstract
Compact and lightweight rotary series elastic actuator (SEA) is a new scheme to realize safe and friendly human-robot interaction of exoskeletons and other human-robot interaction applications. The custom monolithic torsional elastic element is a good choice for the compact design of rotary SEA, but there is a lack of guidance on selecting the topology of elastic elements in a lightweight SEA design. In this paper, with the help of the concept of specific energy, a method based on finite element simulation environment and parametric 3D CAD environment is proposed to determine the topology of the elastic element suitable for lightweight SEA by maximizing the specific energy. By adopting this method, we come to this conclusion: The topology, Archimedes-spiral-based double spiral structure without the outer ring, can be determined as a suitable topology of elastic element for a lightweight rotary SEA.
Optimization of Bearing Displacement in Ship Shafting Alignment Based on Workbench
Authors: Leilei Cui , Junsong Lei , Cunming Lin , Ruiping Zhou 
Published: June 2021

Abstract
Shaft alignment plays an important role in the installation of ship propulsion shafting, ensuring the safety and reliability of ship propulsion shafting. The article takes the shaft system of a 3000m ro-ro ship as an example to simplify the model. Use the workbench platform to perform linear alignment, reasonable alignment and bearing displacement optimization on the shaft system. The results are anastomosis with the results of the traditional three-bending moment algorithm. The optimized displacement result of the bearing can be used as a reference data for shafting installation, which has great practical value.