bluuebunny/crossref_metadata_2025_split huggingface dataset:
Piecewise linear maps with heterogeneous chaos
Authors: Saiki Yoshitaka , Takahasi Hiroki , Yorke James A 
Published: July 2021

Abstract
Chaotic dynamics can be quite heterogeneous in the sense that in some regions the dynamics are unstable in more directions than in other regions. When trajectories wander between these regions, the dynamics is complicated. We say a chaotic invariant set is heterogeneous when arbitrarily close to each point of the set there are different periodic points with different numbers of unstable dimensions. We call such dynamics heterogeneous chaos (or hetero-chaos). While we believe it is common for physical systems to be hetero-chaotic, few explicit examples have been proved to be hetero-chaotic. Here we present two explicit dynamical systems that are particularly simple and tractable with computer. It will give more intuition as to how complex even simple systems can be. Our maps have one dense set of periodic points whose orbits are 1D unstable and another dense set of periodic points whose orbits are 2D unstable. Moreover, they are ergodic relative to the Lebesgue measure.
Complex oscillatory motion of multiple spikes in a three-component Schnakenberg system
Authors: Xie Shuangquan , Kolokolnikov Theodore , Nishiura Yasumasa 
Published: July 2021

Abstract
In this paper, we introduce a three-component Schnakenberg model, whose key feature is that it has a solution consisting of N spikes that undergoes Hopf bifurcations with respect to N distinct modes nearly simultaneously. This results in complex oscillatory dynamics of the spikes, not seen in typical two-component models. For parameter values beyond the Hopf bifurcations, we derive reduced equations of motion which consist of coupled ordinary differential equations (ODEs) of dimension 2N for spike positions and their velocities. These ODEs fully describe the slow-time evolution of the spikes near the Hopf bifurcations. We then apply the method of multiple scales to the resulting ODEs to derive the long-time dynamics. For a single spike, we find that its long-time motion consists of oscillations near the steady state whose amplitude can be computed explicitly. For two spikes, the long-time behavior can be either in-phase or out-of-phase oscillations. Both in-phase and out-of-phase oscillations are stable, coexist for the same parameter values, and the fate of motion depends solely on the initial conditions. Further away from the Hopf bifurcation points, we offer numerical experiments indicating the existence of highly complex oscillations.
Fast flavor oscillations of astrophysical neutrinos with 1, 2, …, ∞ crossings
Authors: Bhattacharyya Soumya , Dasgupta Basudeb 
Published: July 2021

Abstract
In the early Universe, as well as in supernovae and merging neutron stars, neutrinos have such high densities that they affect each other and exhibit collective flavor oscillations. A crucial ingredient for fast collective flavor oscillations is that the electron lepton number (ELN) distribution changes its sign as a function of direction, i.e., has a zero crossing. We present a study in two spatial dimensions and time, focussing on the fast and linear regime, and show how fast flavor oscillations depend on the ELN and its crossings. We show that a large number of crossings can inhibit flavor oscillations. This may be a natural self-limiting mechanism that stabilizes the flavor content of the dense neutrino gas in a vast majority of scenarios, especially the early Universe, where the angular distributions for all flavors are very similar and crossings occur mainly due to fluctuations.
Correction of calculated dynamic scheme of unmanned aerial vehicle based on results of ground modal tests
Authors: Parafes’ S , Turkin I 
Published: July 2021

Abstract
The problem of correcting of the calculated dynamic scheme of an unmanned aerial vehicle (UAV) based on the results of ground modal tests is considered. The provisions that allow achieving satisfactory results when the UAV calculated dynamic scheme correcting are formulated. Correction criteria are considered. Features of the calculated dynamic scheme correction in the study of the flutter and the aeroelastic stability of the UAV with the automatic control system (ACS) are presented. It is noted that along with the provisions that are universal for dynamical aeroelasticity tasks related to the correction of natural frequencies, forms, and coefficients of structural damping of the UAV on the results of ground modal tests, in the study of aeroelastic stability of the UAV with the ACS is also crucial to correct the transfer function of the UAV body from section, in which the rudder rotation axes are located, up to the cross-section, where ACS sensors are installed. This is because the UAV body is directly part of the UAV stabilization loop and significantly affects to its stability reserves. An example of correcting of the UAV calculated dynamic scheme is given.
Assessment of aircraft prospects using a combined method of identifying preferences
Authors: Sudakov V , Sivakova T 
Published: July 2021

Abstract
Recently, the task of replacing the aircraft fleet has been in demand. The aim of the work is a multi-criteria assessment of aircraft and further decisions on their use. To solve this problem, it is proposed to use a combined method for identifying preferences, which is well algorithmic and allows you to take into account dependences on preferences in the multidimensional system of values of the decision maker. An algorithm based on the method of enumeration on a vector lattice has been developed. This algorithm helps the decision maker to take into account a large number of criteria and decide on the need to replace the aircraft. The advantages include a reduction in the calculation time. An interface for entering editing and preferences is proposed, which makes it possible to assess the feasibility of introducing new and withdrawing old aircraft.
Research on the Application of Machine Vision in Tea Autonomous Picking
Authors: Tian Jun , Zhu Honglin , Liang Wenjiang , Chen Jingshan , Wen Feijuan , Long Zhang 
Published: July 2021

Abstract
As a non-destructive, real-time, fast, objective, and economical detection method, machine vision technology has been widely used in target recognition and positioning in various fields in recent years. Selective picking of tea buds is an important prerequisite for high-quality and efficient tea production. Autonomous picking of tea based on machine vision has become a research hotspot at home and abroad. At present, many scholars have studied the visual recognition and positioning methods in the process of intelligent tea picking, but the effect has not yet reached the actual picking requirements. In order to give everyone a comprehensive understanding of the existing research methods, this article systematically reviews the tea bud segmentation and bud picking point positioning methods based on machine vision technology, and prospects the application prospects and directions of machine vision technology in tea picking.
A Pose Transformation Estimation Method Based on Feature Extraction and Matching in Ceramic Green Body Bonding Process
Authors: Ma Qihang , Zhang Jian 
Published: July 2021

Abstract
Bonding the ceramic green-bodies of the seat ring to the cup body is an important step in the production process of the toilet. This paper proposes a pose transformation estimation method based on feature extraction and matching in ceramic green body bonding process. This method uses a Local Feature Statistics Histogram (LFSH) to extract the features of the bonding surfaces and find the corresponding point sets. Then, a Sample Consensus Initial Aligment (SAC-IA) algorithm combined with LFSH features is used to perform coarse registration calculation. Finally, using the Iterative Cloest Point (ICP) algorithm, the result of the coarse registration is used as the initial value to complete the fine registration and obtain the pose transformation matrix. Before registration, the relative poses of the two point clouds are randomly transformed. This method is tested on the point cloud data of the cup body and the seat ring. Experimental results show that the role of SAC-IA can increase the speed of registration compared to using ICP alone.
Research on driving force of electric four-wheel drive rodless aircraft tractor when crossing obstacles
Authors: Zhang Mingyang , Liu Huan 
Published: July 2021

Abstract
In this paper, the static analysis of an electric four-wheel drive rodless aircraft tractor over obstacle with load is carried out. Based on MATLAB, all combination of front and rear wheel driving forces are calculated, and the minimum driving force required for obstacle surmounting under different parameters is obtained. The above work provides necessary theoretical basis for tractor design.
Parametric design of inner teeth of center wheel in electromagnetic harmonic movable teeth transmission
Authors: Yubo Ren , Yaoyang MA , Rui Wan 
Published: July 2021

Abstract
In order to improve the rationality and design efficiency of the structural parameters of the electromagnetic harmonic movable teeth drive system, the rationality of the set parameters is judged based on theoretical calculation, and visual programming is carried out by using VB. The designer only needs to input the set parameters into the specified dialog box to get the corresponding output results, which makes the design of the inner teeth of the center wheel more convenient and fast.
Design and analysis of permanent magnet synchronous servo motor with low rotational inertia and high torque density
Authors: Chenwei Yang , Fei Dong , Yi An , Fengqing Zhu 
Published: July 2021

Abstract
Aerospace servo motor has the characteristics of strong load capacity, fast response and high control accuracy. To satisfy the design target of high dynamic performance and low weight, the high magnetic loading ironless-core array rotor structure is applied to balance the low rotational inertia and high torque density of permanent magnet servo system.
Study on critical condition of dynamic recrystallization of large back-up roll steel
Authors: Qi Peng , Ren Facai , Xu Jinsha 
Published: July 2021

Abstract
70Cr3Mo alloy steel is mainly used to produce large back-up roll for cold rolling mill, which has higher processing quality requirements. In this paper, the hot compression test of 70Cr3Mo large back-up roll steel was carried out, and the flow stress curves under different deformation temperatures and strain rates were obtained. The critical condition of dynamic recrystallization of the steel was determined by calculation and fitting, and the critical stress formula of dynamic recrystallization was obtained.
The structure design of the end picker for the automobile control arm stamping production line
Authors: Xiaogang Liu , Junchen WU 
Published: July 2021

Abstract
In the process of stamping, production and transportation of automobile control arm, the surface of the workpiece can not be adsorbed due to the oil stains on the surface of the workpiece. The traditional vacuum chuck can not be adsorbed. The electromagnetic chuck will generate heat for a long time and cause the magnetic force to decline, resulting in reduced reliability and causing the workpiece to fall off. The principle uses NdFeB material to design a new type of electric permanent magnet end picker. When the power is cut off, it relies on the magnetic force of the permanent magnet to adsorb. After the robot transfers the workpiece, the coil around the reversible material is passed through an electric current to generate an electromagnetic field opposite to the permanent magnet. To counteract the magnetic force, the workpiece is separated, the end suction cup of the end picker is designed according to the quality of the workpiece and the contact area, and ANSYS ELECTRONICS is used for modeling analysis and verification. The data shows that the device can meet the needs of the car control arm grasping and handling work. It provides a new idea for automatic production line of automobile control arm.
Finite element simulation of plough cone cutter
Authors: Li Guangqiao , Liu Xiaomin , Bai Zongxi 
Published: July 2021

Abstract
In order to improve the ROP of the PDC bit, a plough cone cutter was designed and finite element simulation was performed. Compared with conventional cutter, plough cone cutter has smaller stress field and strain field in the rock breaking process. The largest tangential rock breaking force and maximum axial rock breaking force is higher, but the average tangential rock breaking force and the average axial rock breaking force are smaller, and the rock breaking effect is better; the back dip angle has a significant impact on the rock breaking effect. Under the same plough cone cutter, with the increase of the inclination angle, the stress field and strain field of the rock after rock breaking will become smaller, and the rock breaking effect will be better. Therefore, the plough cone cutter with a backward inclination angle of 22° has an advantage in the rock breaking process.
Artificial vascular implants with unidirectional drug release and mechanical properties imitating natural blood vessels
Authors: Bin Wang , Yi Zhang , Junchao Hu , Yuanyuan Liu 
Published: July 2021

Abstract
Small-diameter artificial vessels require a combination of a range of material properties, including high strength, compliance, sutureability, and kink resistance in specific situations. We combined electrospinning technology with thermally induced separation technology to prepare composite three-layer artificial vessels using a PCL/gelatin co-blended material and a hybrid hydrogel enhanced gel structure to achieve high strength, flexibility and kink resistance, as well as excellent water tightness. The electrospun fibers in the artificial vessel provide mechanical stability, while the gelatin blended material enhances hydrophilicity. The results show that the three-layer composite structure is well bonded together, provides sufficient rupture strength and sutureability, and exhibits arterial-like compliance and resistance to kinking. The hydrogel layer drug release rate can also be adjusted by adjusting the PCL/gelatin co-blended layer ratio. This composite vascular scaffold is expected to play an important role in tissue engineering.
Lipschitz discrete observer design for HCCI engine mixed gas temperature at intake valve closed
Authors: Zheng Taixiong , Yang Xinqing , Li Yongfu , Ma Ying 
Published: July 2021

Abstract
The gas temperature for Homogeneous Charge Compression Ignition engine at intake valve closed is difficult to measure; so a Lipschitz discrete observer is designed. In particular, a single cylinder engine model is proposed. And, a thermodynamic process based state equation is presented considering the heat loss of residual exhaust gas. Consequently, a discrete nonlinear state observer is designed using Lipschitz condition. Finally, the numerical experiments are performed. The results demonstrate the effectiveness of the proposed observer in terms of the accuracy and robustness.
Design of a New Engine Hood based on Lattice Structure for Pedestrian Protection
Authors: Liu Meng , Sun Fuzhen , Wang Baoming , Wang Jianfeng , Yang Na 
Published: July 2021

Abstract
This paper designs four kinds of three-dimensional negative Poisson’s ratio lattice structures, based on the two-dimensional concave hexagonal negative Poisson’s ratio honeycomb structure. Different parameters are designed for simulation analysis and experimental research, and the influence of different parameters on Poisson’s ratio is studied respectively. The main contents are as follows: Firstly, the three-dimensional solid model of lattice structure is established by modeling software, and the different structural parameters are determined, and the equivalent mechanical model is established. And according to the relevant structural parameters to establish the test scheme. Then, the finite element software is used to simulate the test core material with different parameters. According to the simulation results, the influence of different parameters on Poisson’s ratio is found out. Then the crashworthiness of the test board with different parameters is simulated and analyzed. According to the results, the most suitable structure is selected and applied to the engine hood. Finally, the simulation experiment of collision between pedestrian head and engine hood is carried out. The results of this paper compare the performance of lattice sandwich panels with different parameter structures in different tests and select the optimal combination of structural parameters. The adjustment and optimization direction of the structure is put forward according to the test results.
Pattern Recognition of Quality Control Chart of Multi-variety and Small-batch Production Mode Based on MC-GA Optimized BP
Authors: Meng Lili , Ji Kun , Zheng Lei , Sun XiaoWei 
Published: July 2021

Abstract
To solve the problem of product quality control in multi-variety and small-batch production mode, a quality control chart recognition model of MC-GA optimized BP was established by using Monte Carlo method to simulate the product quality data characteristics of different varieties and combining the data processing capability of neural network and the adaptive global optimization search capability of genetic algorithm; then the MC(Monte Carlo method)-GA(Genetic Algorithm) optimized BP(Back Propagation Neuron Network) was compared with the traditional MC-BP is compared and analyzed in terms of accuracy, time and error in quality control graph pattern recognition, and it is concluded that the former is better in quality control graph pattern recognition. It can be seen that the MC-GA optimized BP model is more effective in identifying the quality status of products in the multi-variety and small-batch production mode, and can accurately predict the stability of the manufacturing process, so as to enhance the competitiveness of enterprises.
Research on compliant path planning of two-machine cooperation of industrial robots
Authors: Zhao Wei 
Published: July 2021

Abstract
Since its invention, industrial robots have developed into intelligent automation equipment that integrates multi-disciplinary technologies and are widely used in manufacturing and other industries. With the increasing requirements for the development of productivity, the application research of multi-robot cooperative work unit highlights its importance. In order to realize the safe and stable operation of robots, it is necessary to carry out collision-free and compliant path planning. This paper analyzes the related theories of industrial robot two-machine cooperation, combines the key points of industrial robot two-machine cooperation compliant path planning, and establishes a simulation experiment to simulate the application process. Its purpose is to accumulate reliable application data and lay the foundation for the continuous optimization of the cooperation system.
Grinding machine CNC with noble integrated motion control system
Authors: Qinghua Wang , Yanhua Hu , Renxuan Fu , Junyong He 
Published: July 2021

Abstract
According to research progress and applying technology of CNC control system architecture, this paper discusses three kinds of CNC control systems: Open CNC system, embedded CNC system and PLC CNC system, and a new architecture is proposed. The paper illuminates that integrated motion control system architecture is a new concept of CNC, by which it has high precision and low cost. In this paper, a grinding machining controller using this structure is described and verified by software.
Research of Mechanical Interface Control Model for Aircraft Digital Mock up
Authors: Jian Xu , Xinai Zhang , Hao Su 
Published: July 2021

Abstract
Mechanical interface design is used to clarify the design division and interface of all parties, and is one of the important tasks of aircraft design. The mechanical interface control model is a digital representation of the mechanical interface characteristics between one aircraft system (including structure) and another. It is a model carrier for mechanical interface design collaboration. This article introduces the definition and classification of the mechanical interface control model of the aircraft digital mock up, focuses on the general design process, requirements, application and management of the mechanical interface control model, it provides relevant reference and help for the design and management of the mechanical interface of the aircraft digital mock up.
A Novel 5G Band Filter Based on Ceramic Dielectric
Authors: Luo Bing , Zhan Zhong-shan , Fang Bo , Zhang Jian-bao 
Published: July 2021

Abstract
The construction of 5G system is in the works. In order to improve the anti-interference and reduce the volumes of 5G system, it is important to design a filter with better filtering performance and smaller volume. At present, the research of 5G filter is almost base on metal resonator. This paper designs a ceramic dielectric resonator, and on the basis of the designed dielectric resonator, a 5G band dielectric filter is designed after theoretical calculation and analysis by using rf/microwave simulation software HFSS. The coefficients are realized by the distance between two resonators, and the Q value is realized by the distance between the input port and the first resonator. The results show that in the pass-band (3.4 ∼ 3.5GHz), the return loss is more than 15dB, the insertion loss is less than 0.35dB, and the VSWR is 1.62. The filter has the advantages of small insertion loss, small size and good rejection out of pass-band, which can be applied to 5G band wireless communication system with better suppression performance to improve the communication quality of the communication system.
Dynamic Performance study of Giant Magnetostrictive Actuator
Authors: Yan Wu , Yong He , Haoran Song , Zhijuan Ding , Xuhui Liu 
Published: July 2021

Abstract
Optimized design problems for giant magnetostrictive actuator (GMA) structures, the effects of structural dimensions on dynamic properties of GMA were analyzed. In this paper, an equivalent dynamic model of GMA was established, and the step response and frequency response of GMA were simulated and analyzed. The results show that the length of the giant magnetostrictive rod and the mass of the load have great influence on the dynamic performance of the GMA system.
The Study of Rice Shell Ash Precipitation Legal System for Silica
Authors: Zhang Peng , Liu Ao , Zuo Huimin , Zhou Mingyuan 
Published: July 2021

Abstract
Using rice husk ash as raw material, low modulus sodium silicate was prepared and high dispersion white carbon black was prepared by chemical precipitation method. The effects of sulfuric acid concentration, reaction temperature and aging time on the oil absorption value (DBP). The high dispersion white carbon black was characterized by laser particle size analyzer, X-ray diffractometer, DBP and scanning electron microscope (SEM). The results show that when the sulfuric acid concentration is 5%, the temperature is 85°C, and the aging time is 60min, the silica morphology is spherical, and the average particle size is about 5 micron, the oil absorption value is 2.82.