bluuebunny/crossref_metadata_2025_split huggingface dataset:
Decay of negativity of randomized multiqubit mixed states
Authors: Mansour M , Oulouda Y , Sbiri A , El Falaki M 
Published: February 2021

Abstract
In this paper, we investigate the decay of entanglement of multiqubit randomized entangled states. We start by introducing separable states of collection of n independent qubits. The randomized entangled mixed states are generated from factorisable initial states by coupling the qubits through randomized entangling operators. The bipartite and multipartite entanglement of randomized states are analyzed by employing respectively the concepts of the negativity and the genuine multiparticle negativity as measures of amount of entanglement. The decreases of the amount of entanglement of randomized entangled mixed states is studied in terms of the noisy parameter p.
Industrial 6 kW high-stability single-stage all-fiber laser oscillator based on conventional large mode area ytterbium-doped fiber
Authors: Ye Yun , Yang Baolai , Wang Peng , Zeng Lingfa , Xi Xiaoming , Shi Chen , Zhang Hanwei , Wang Xiaolin , Zhou Pu , Xu Xiaojun 
Published: February 2021

Abstract
We have demonstrated an industrial 6 kW single-stage end-pumped all-fiber laser oscillator based on a conventional large mode area ytterbium-doped fiber (YDF) with 30 μm core diameter and 600 μm inner-cladding diameter. As a result, the fiber oscillator achieved a maximum output power of 6.07 kW at a central wavelength of ∼1080 nm with a slope efficiency of ∼65.8%. The power of Raman Stoke light was 21.6 dB smaller than the signal light at the output power of 6.07 kW. For industrial application, the stimulated Raman scattering effect was further suppressed by employing a 50 μm-core delivery fiber, and no sign of dynamic transverse mode instability comes into view during the whole experiment. The power stability measurement at ∼6 kW operation was carried out for continuous 2 h, and the power fluctuation was within 0.31%. To the best of our knowledge, this is the first detailed demonstration of industrial 6 kW high-stability single-stage all-fiber laser oscillator based on conventional YDF. The results provide a significant guidance for the construction of more than 6 kW output power single-stage end-pumped all-fiber laser systems.
The advanced tokamak path to a compact net electric fusion pilot plant
Authors: Buttery R.J. , Park J.M. , McClenaghan J.T. , Weisberg D. , Canik J. , Ferron J. , Garofalo A. , Holcomb C.T. , Leuer J. , Snyder P.B. 
Published: February 2021

Abstract
Physics-based simulations project a compact net electric fusion pilot plant with a nuclear testing mission is possible at modest scale based on the advanced tokamak concept, and identify key parameters for its optimization. These utilize a new integrated 1.5D core-edge approach for whole device modeling to predict performance by self-consistently applying transport, pedestal and current drive models to converge fully non-inductive stationary solutions, predicting profiles and energy confinement for a given density. This physics-based approach leads to new insights and understanding of reactor optimization. In particular, the levering role of high plasma density is identified, which raises fusion performance and self-driven ‘bootstrap currents’, to reduce current drive demands and enable high pressure with net electricity at a compact scale. Solutions at 6–7 T, ∼4 m radius and 200 MW net electricity are identified with margins and trade-offs possible between parameters. Current drive comes from neutral beam and ultra-high harmonic (helicon) fast wave, though other advanced approaches are not ruled out. The resulting low recirculating power in a double null configuration leads to a divertor heat flux challenge that is comparable to ITER, though reactor solutions may require more dissipation. Strong H-mode access (x2 margin over L–H transition scalings) and ITER-like heat fluxes are maintained with ∼20%–60% core radiation, though effects on confinement need further analysis. Neutron wall loadings appear tolerable. The approach would benefit from high temperature superconductors, as higher fields would increase performance margins while potential for demountability may facilitate nuclear testing. However, solutions are possible with conventional superconductors. An advanced load sharing and reactive bucking approach in the device centerpost region provides improved mechanical stress handling. The prospect of an affordable test device which could close the loop on net-electric production and conduct essential nuclear materials and breeding research is compelling, motivating research to validate the techniques and models employed here.
Cramér moderate deviations for the elephant random walk
Authors: Fan Xiequan , Hu Haijuan , Ma Xiaohui 
Published: February 2021

Abstract
We establish some limit theorems for the elephant random walk (ERW), including Berry–Esseen’s bounds, Cramér moderate deviations and local limit theorems. These limit theorems can be regarded as refinements of the central limit theorem for the ERW. Moreover, by these limit theorems, we conclude that the convergence rate of normal approximations and the domain of attraction of normal distribution mainly depend on a memory parameter p which lies between 0 and 3/4.
Research on Improvement of Temperature Rise of New Energy Vehicle Generator
Authors: Bing Xu 
Published: February 2021

Abstract
New energy vehicles have gradually become one of the key parts in the development of the automotive field under the background of the new era. It is also to comply with the requirements for environmental protection. Therefore, this article analyzes the reasons for the excessive temperature of the generators of new energy vehicles, and proposes targeted improvement strategies in combination with the actual situation. While ensuring that the output torque of the new energy vehicle generator itself can be effectively increased, it can ensure that the basic requirements of the new energy vehicle to the greatest extent.
Improved droop control of DC microgrid based on virtual impedance
Authors: Yuan Yizhe , Deng Yanni 
Published: February 2021

Abstract
In order to solve the problem of distributed energy generation, microgrid has been proposed as one of the options. Compared with AC microgrid, DC microgrid is more suitable for many current distributed power equipments. In order to ensure the stable operation of the DC microgrid, it is necessary to develop an effective energy management strategy. As a typical method of current distribution, droop control has been widely studied and discussed. Traditional droop control has inherent limitations, so this paper proposes an improved method for droop control.
Research of pulsed Xenon lamp power supply based on STM32
Authors: Liu Danni , Ma Mengfei , Zhang Yanjin 
Published: February 2021

Abstract
Novel coronavirus pneumonia affects the health of people all over the world. In this study, UV pulse high-light sterilization technology was used to combat coronavirus. The light source of the ultraviolet pulsed high-light disinfection robot is a kind of high-brightness flash light source using pulsed xenon lamps as the output load. This paper developed a pulsed xenon lamp power supply with a high-voltage pulse synchronous trigger function, a DC charging voltage of 1kV-3kV, an output pulse current range of 1kA-3kA, and a pulse width of 50μS for a pulsed xenon lamp with a 196mm×Φ10mm and a resistivity of 12Ω⋅A1/2. This paper presented the experimental results of charging voltage of 1kV, output pulse current peak value of 1kA, and pulse width of 50μS. The power supply design was based on the phase-shifting voltage regulation mode of UC3825 control power MOS tube, through the sampling isolation module and the closed-loop feedback formed by STM32 control, the energy storage capacitor was linearly charged through the DC voltage sampling and voltage regulation control module; the trigger pulse signal was generated by the SCR switch, and the xenon lamp was turned on and emits flash light after the pulse transformer was boosted. The sample test results verified the feasibility of the power supply design principles and technical solutions.
Design of DC Regulated Power Supply Based on Buck Circuit
Authors: Shuang Wang Xiao , Jing Zhao , Wei Li Hong , Hai Liu Yi 
Published: February 2021

Abstract
DC stabilized power supplies are widely used in automotive, aviation and DC speed control fields. This article introduces the method of applying buck circuit design to realize 5V switching DC power supply. The designed switching power supply has the advantages of small ripple, continuously adjustable, good stability, etc, and can be used in low-voltage and highpower power supply situations.
Research on damping addition and vibration reduction technology of frame aerospace electronic chassis
Authors: yu Zhang , bolin Zhang 
Published: February 2021

Abstract
This paper poses a box instrumentation in aerospace electronic chassis TO-5 encapsulation relay under the action of impact environmental load state of reverse fault mode, by reasonable single frames of viscoelastic damping materials added, increasing box style structure between the PCB mechanical installation interface damping ratio and frequency ratio, finally realizes the transfer rate is reduced, achieve instrumentation relay PCB, lower impact acceleration response. By adding damping cushion to the frame machine installation interface, the load transfer path of impact mechanics is optimized to reduce the installation stiffness and change the fundamental frequency characteristics of the whole machine.
Analysis and Simulation Research on Radial Electromagnetic Force Wave of Permanent Magnet Synchronous Motor
Authors: Sun Zhen , Xu Yufa , Zhao Xinliang 
Published: February 2021

Abstract
Aiming at the problems of vibration and noise of permanent magnet synchronous motors, based on the principle of radial air gap magnetic density generation, a model of radial electromagnetic force waves is constructed, and the radial air gap magnetic density and diameter of permanent magnet synchronous motors are derived by analytical analysis Analytical expression of the electromagnetic wave, to obtain the main order, frequency and amplitude of the radial electromagnetic wave. Using Maxwell 2D simulation software to establish a simulation model, verify it, prove the correctness of the proposed method, and provide a theoretical basis for further research on the vibration and noise of permanent magnet synchronous motors.
Design and Realization of Intelligent Vehicle Based on Embedded System
Authors: Guanghong Song , Tai hu Zuo , Li li Zhao 
Published: February 2021

Abstract
The paper takes the STM32F103ZET6 development board as the core to design a smart car with a PC-side real-time monitoring system and infrared wireless remote control. It is equipped with a small OLED display to monitor the running state of the necessary services in the car and the system network in real time through Wi-Fi monitoring video transmission and display, using infrared receiver and remote control to achieve NEC protocol communication, and control the wireless movement and the steering of a two-degree-of-freedom camera.
EMC hardware design of intelligent watt-hour meter
Authors: Liu Xingzhi , Zheng Ke , Lv Fengbao , Wei Changming , Tian Juan 
Published: February 2021

Abstract
Electromagnetic compatibility (EMC) is very important for intelligent instruments, and it is an important guarantee for its reliable operation. The complexity of EMC is mainly reflected in how to quickly and accurately locate the disturbance source, effectively suppress the disturbance source, and correctly judge the disturbance coupling path. Intelligent instruments have similar hardware characteristics. In this paper, the characteristics of common hardware characteristics of disturbance source and coupling path are analyzed, the equivalent antenna model of disturbance is analyzed, and the disturbance suppression method is given. Finally, the correctness of the method is verified by experiments.
Research on Test Method of Radio Frequency Radiation Antiinterference of Road Vehicles
Authors: Cao Changping , Tao Hu , Chuan Yang , Pan Yuehong , Yuan Shengjun 
Published: February 2021

Abstract
Based on the comparison and analysis of ISO11452-2 (2004 and 2019), the differences in the testing of radiation immunity Absorber-lined shielded enclosure method are sorted out, and the testing requirements of the newly added High voltage electronic parts components are interpreted.
MOSFETS Power Consumption and Power Dissipation Calculation
Authors: Wang Junkai 
Published: February 2021

Abstract
Metal oxide semiconductor field effect transistors are usually called MOSFET. Nowadays, MOSFET is one of the most crucial electrical components that engineers usually use when constructing laptops and desktop computers. A large number of MOSFETS are usually integrated together to form control and logic functions of computers CPU. Thus, it is essential for electrical engineers to know what type of MOSFETS is appropriate for them to use when designing the integrated circuits. Engineers can seek the answer through calculating two of the most basic and important components of MOSFET power consumption and power dissipation. This article walks through the steps of calculating the power consumption and power dissipation of MOSFETS to provide electrical engineers, students and circuit designers with a clear thought of how to do the calculation under some complex circumstances. MOSFETS power consumption calculation is different under 3 different modes which are cutoff mode, saturation mode and triode mode. Under cutoff mode, the power consumption is zero. Under saturation mode, power consumption is calculated by MOSFETS consume certain amount of power and the total amount of power can be calculated by finding integral of the IV curve. For triode mode, power consumption can be determined by the equation derived later in the article. As for power dissipation, in this article, total power dissipation is divided into two parts which are switching power dissipation and resistive power dissipation. Then, each part of power dissipation is calculated by equations listed in the article and then added together which is the total power dissipation of MOSFETS.
3D reconstruction method of inner surface of pipeline
Authors: Chen Xu , Zhang Yan , Zhao Kang , Guo Jinyu , Luo Ruiliang 
Published: February 2021

Abstract
With the rapid development of China, there is a huge demand for PE pipelines. At present, the detection methods in pipeline production are mainly manual sampling testing and ultrasonic testing, which cannot display the internal surface characteristics of the pipeline comprehensively and visually, so as to facilitate the subsequent non-destructive testing. To solve this problem, this paper proposes a method to capture the three-dimensional feature data in the pipe with a depth camera, and transmit the collected point cloud data into PC for processing, identification and reconstruction, so as to realize the non-destructive testing of the inner surface of PE pipe.
Analysis of small signal model of DC/DC converter without source and load effects
Authors: Zhang Wenjie 
Published: February 2021

Abstract
The small signal model of DC/DC converter without source and load effects is established and analyzed in detail. Characteristics of input and output impedance of converter in frequency domain in the model are applicable to the stability analysis and design in DC multi-converter power system. Investigation shows that the resonant characteristics of input and output impedance under closed-loop control are closely related to the crossover frequency and phase margin of control loop. The input impedance resonant valley and output impedance resonant peak locate at the same frequency as the loop crossover frequency. Furthermore, when the phase margin decreases, the resonance valley of the input impedance becomes lower and the resonance peak of the output impedance becomes higher. Finally, the accuracy of the model is verified by MATLAB Simulink time domain simulation.
A Method to Reduce Torque Ripple of Brushless DC Motor
Authors: Liu Sihao , Yao Xiaodong , Shen Yali 
Published: February 2021

Abstract
In order to improve the accuracy of the commutation of the brushless DC motor rotor, considering that the traditional modulation method will be affected by the conduction voltage drop of the switch tube and the freewheeling diode, resulting in the non-conduction phase freewheeling during the non-commutation period Torque ripple, which is also the main cause of torque ripple. Therefore, it is a positionless control method that controls the non-conducting phase torque ripple PWM_ON_PWM modulation. However, due to PWM modulation, off-phase freewheeling will inevitably occur. For this, the resonant DC link soft-switching inverter topology is used to suppress the off-phase freewheeling. Through experiments and simulations, it is proved that these combined methods can effectively reduce the size of torque ripple.
Multi-target charging strategy for smartphones based on laser wireless power transmission and machine vision technology
Authors: Yu Huiling , jin Ke 
Published: February 2021

Abstract
A novel method of multi-target charging is proposed in this paper, in the context of charging multiple indoor mobile phones simultaneously. Based on the laser wireless power transmission system, combined with machine vision technology, the traditional two-stage circuit is turned into a single-stage type, which realizes longer distance and more convenient charging. This article analyzes the working mode and circuit topology of the dc-dc converter in the multi-target charging mode, and analyzes the positioning and charging strategies for multi-targets based on machine vision. Under the strategy, the output voltage of the photovoltaic panel can be adjusted by modulating the pulsed light, so as to achieve the maximum power control for mobile phone charging. The simulation results are provided in this paper to validate the effectiveness of the proposed approach.
Research on Robotic Arm Movement Grasping System Based on MYO
Authors: Wei Ye , Jia Danping 
Published: February 2021

AbstractThis paper studies the continuous motion capture system of a robotic arm based on MYO. The MYO sensor can collect the electromyographic signal (sEMG) and the motion signal (IMU) of the arm during exercise, and filter the electromyographic signal, extract the features, and return the features. After the first transformation, the machine learning algorithm is used for model training. In order to verify the effect of the recognition of the EMG signal on the deep learning method, the accuracy comparison experiment with the BP neural network is also added. In addition, a two-link arm model was built, and the pose information of the end of the arm was obtained through Euler angle transformation, and then the end pose information of the robotic arm was obtained through coordinate mapping, and the end pose simulation was performed using Matlab software. The simulation results prove that the performance of the system meets expectations, and points out the direction for subsequent research.
Research on Intelligent Technology of CNC Machine Tool Industrial Design
Authors: Guiming Qian 
Published: February 2021

Abstract
The level of economic development of a country can be demonstrated by the development of the machinery manufacturing industry. At present, the industrial design of CNC machine tool in China is progressing in the direction of intelligence, providing more efficient processing technology to meet the needs of the times and social development. However, there are still many challenges, which are the key research of the current intelligent industrial design technology. The article will analyze the significance of industrial design intelligence technology to CNC machine tool, analyze the current research status and propose the application strategies.
Research on Natural Scene Text Detection and Recognition
Authors: Wang Jieming , Wu Wei 
Published: February 2021

Abstract
In recent years, as the importance of scene text detection and recognition in real life has gradually become prominent, its research methods have become mature, and more attention has been placed on improving accuracy. Due to the complex background in natural scenes, different font arrangements, lighting, etc., various methods are difficult to meet the requirements of the application. In this paper, the detection and recognition of curved text are studied, and the research method based on the ESIR framework[1] is improved, specifically in the following two aspects: (1) TPS transform fiducial points are predicted by the positioning network, and the positioning network uses CNN to return to the required fiducial points[2] The x and y coordinates. (2) Using ACE (aggregated cross entropy) method for sequence recognition, its loss function is realized faster and it occupies less memory than CTC and attention mechanism, and it performs well in the one-dimensional prediction of scene text recognition. In this paper, the irregular data set is sampled by reference points, and the parameter matrix T of TPS is calculated to transform the points in the picture, and cyclically transform until the image text is level, and then use the CNN-BLSTM model to perform one-dimensional prediction and output the recognition results. The selected data set is irregular text data set: for example, SVT-Perspective, CUTE80.
Global maximum power tracking algorithm for solar photovoltaic array under uneven illumination
Authors: Guo Jianlong 
Published: February 2021

Abstract
Based on the analysis of the shortcomings of the existing maximum power point tracking (MPPT) method, a multi-peak MPPT tracking strategy is proposed based on the geometric characteristics of the output curve of photovoltaic array. This method takes advantage of the fact that the pv array U-I output curve has the characteristics of "the left slope changes slowly and the right slope changes quickly" at the local extrema point, quickly locates the voltage interval including the global maximum power point, and converts it into a perturbation observation method (perturb and observe, P&O) with higher tracking accuracy within this interval. Thus, the global maximum power point can be tracked. By comparing this algorithm with improved disturbance observation (Perturb, observe and check, POC), its application range was determined and applied flexibly. The algorithm is fast and can avoid missing peak value effectively.
Summary of Recommendation Algorithm Research
Authors: Yan Jie , Zeng QingTao , Zhang FuQian 
Published: February 2021

Abstract
In order to solve the problem of information overload caused by the rapid expansion of information, it is particularly difficult for users to select the information they are interested in when faced with massive amounts of information. Traditional search has some drawbacks and cannot solve the problem of information overload. The recommendation algorithm provided by the recommendation system is a good strategy to deal with. This article mainly introduces two recommendation algorithms and their principles, content-based recommendation algorithms and collaborative filtering-based recommendation algorithms. And their advantages and disadvantages are compared.