bluuebunny/crossref_metadata_2025 huggingface dataset:
Research on 4G And 5G Authentication Signaling
Authors: Song Lei , Xu Zhan , Tian Zhigang , Chen Jinhui , Zhi Ruxin
Published: June 2019

In recent years, the development and standardization of 5G networks have received extensive attention. 3GPP officially confirmed that Service-Based Architecture (SBA) is the unified infrastructure of the 5G core network (5GC). The Service-Based Interface (SBI) is an important part of the SBA for interaction between network function services within the 5GC. The fifth generation mobile network will support a range of use cases and requirements that are completely different from traditional 4G networks, such as providing a high level of authentication mechanisms. This paper is organized as follows: First, we compare the difference between 4G authentication and 5G authentication in three aspects including the 4G architecture, authentication process, and communication protocol stack, then implement the simulation environment, and finally evaluate the performance by comparing the delay.
Temporal Convolutional Networks for Anomaly Detection in Time Series
Authors: He Yangdong , Zhao Jiabao
Published: June 2019

Convolutional Networks have been demonstrated to be particularly useful for extracting high level feature in structural data. Temporal convolutional network (TCN) is a framework which employs casual convolutions and dilations so that it is adaptive for sequential data with its temporality and large receptive fields. In this paper, we apply TCN for anomaly detection in time series. We train the TCN on normal sequences and use it to predict trend in a number of time steps. Prediction errors are fitted by a multivariate Gaussian distribution and used to calculate the anomaly scores of points. In addition, a multi-scale feature mixture method is raised to promote performance. The validity of this method is confirmed on three real-world datasets.
Research on the Performance Assessment of Teaching Cloud Platform Based on Fuzzy Comprehensive Evaluation
Authors: Yang Yi , Song Yan
Published: June 2019

Teaching cloud platform is a complex system in which enterprises, teachers, experts, and students participate together. The quality of teaching platform based on cloud computing is directly related to the normal development and effect of teaching work. According to the principle of comprehensive evaluation of an information system, the performance evaluation index system model of teaching cloud platform is first constructed. Then evaluation research with fuzzy comprehensive evaluation method is conducted on the system. Finally, experimental verification on an example is completed.
Research on Multi-wavelength Fiber Laser Based on Nonlinear Effect
Authors: Lv Xiao-Guang , Liao Tong-Qing , Yi Yan
Published: June 2019

A multi-wavelength erbium-doped fiber laser (MWEDFL) is introduced, which uses highly erbium-doped fiber (EDF) as the gain medium and uses the nonlinear effect of the single mode fiber to suppress the mode competition. In order to obtain higher side mode suppression ratio and flatness, a nonlinear fiber loop mirror is added to the structure. The results show that a stable multi-wavelength laser with 16 lasing wavelengths and a side mode suppression ratio (SMSR) higher than 30dB is obtained.
The simulation of Active Disturbance Rejection Control for the temperature control in space environment
Authors: Ning Juan , Shao Jing-yi , Zhou Ying , Wang Zi-juan
Published: June 2019

In order to improve the temperature control effect of nonlinear, large time-delay and inertia space environment simulation equipment, and to solve the contradiction between heating rapidity and overshoot, this paper introduces the Active Disturbance Rejection Control algorithm into space environment simulation temperature control. Based on the platform model, Active Disturbance Rejection Control controller was designed, and the cascade control model of the heat sink gas-nitrogen temperature space environment simulation equipment was established. The cascade control system was simulated on the MATLAB software platform, and the specimen was raised from 0 °C to 100 °C. The step response rise time was about 4000 s. The specimen rise temperature rate is about 1.5°C/min, and the temperature control process is smooth and there is no overshoot. The simulation shows that the Active Disturbance Rejection Control can effectively improve the space environment simulation temperature control effect.
Integrated VCSOA and PIN with high sensitivity
Authors: Dong Zhixing , Li Xun , Wang Heng , Zuo Chengliang
Published: June 2019

An integrated vertical cavity semiconductor optical amplifier (VCSOA) and PIN photodetector was proposed in attempting to raise the sensitivity in high speed fiber-optic communication systems. Two slightly different structures have been studied under this configuration. For the cascade and the resonance structure, our simulation results showed that their sensitivity could reach -33dBm and -36dBm at a bit rate of 10Gb/s, respectively. We also managed to fabricate the cascade structure and demonstrated a 7dBm improvement on sensitivity as compared to the conventional PIN photodetector.
Inverse Designed Ultra-compact Broadband High-order Mode Filter
Authors: You Guoqing , Gao Dingshan
Published: June 2019

Utilizing the inverse design method of nonlinear direct-binary-search (DBS) optimization algorithm, we designed an ultra-compact broadband high-order mode filter on silicon-on-insulator wafer. The incident TE0 mode is prohibited to pass through the high-order mode filter while the TE1 mode can pass with low insertion loss. The footprint of this mode filter is only 1.56 μm × 2.4 μm. Numerical simulation shows that the insertion loss of this mode filter is lower than 0.26 dB and the extinction ratio is lower than 24.5 dB in the wavelength range from 1500 nm to 1600 nm. The insertion loss at the centre wavelength of 1550 nm is only 0.18 dB.
Three-dimensional Acoustic Target Surface Reconstruction Method Based on Marching Cubes
Authors: Liu Jingyang , Zeng Xiangrui , Xue Huanhuan
Published: June 2019

Marching Cubes is an isosurface reconstruction algorithm based on volume data. In order to solve the problems of low resolution, rough surface, insufficient texture and stereo sense in the process of three-dimensional acoustic target’s visualization, a method based on Marching Cubes is used to reconstruct the surface of three-dimensional acoustic target in this paper. By constructing the minimal cube in acoustic data field, determining the connection mode, vertex coordinates and normal vectors of triangle elements in the cube where the target contour lies, we establish the target’s three-dimensional surface model, and the reconstruction of three-dimensional acoustic target is realized. The performance and validity of the method are validated by the sea trial data from three-dimensional imaging sonar, and the performance of the method is tested by multi-resolution data, and a three-dimensional surface model of buried target is constructed based on the sea trial data. The results show that the surface reconstruction technology of three-dimensional acoustic target based on marching cubes algorithm has the advantages of simple structure and less computation, and the time-consuming of the algorithm is proportional to the number of sampling points. In the process of three-dimensional acoustic image visualization, surface reconstruction technology can effectively improve the stereo sense and recognition of buried targets.
Three-dimensional Imaging Sonar Signal Processing System Based on Blade Server
Authors: Zeng Xiangrui , Liu Jingyang , Gao Bo
Published: June 2019

The three-dimensional high-resolution imaging sonar uses multi-beam technology combined with synthetic aperture technology to achieve centimeter-level imaging of small underwater targets. It has a good imaging effect on underwater anchoring, sinking mine and buried mine target detection and underwater topography, and has a wide range of military and civil engineering applications. The system has a large amount of data transmission and computation, including multiple functional modules such as synthetic aperture, high resolution array processing, image processing, and target recognition. The software architecture is complex and real-time system development faces serious challenges. The blade servers have been widely used in the telecommunications, financial and other big data processing fields as for the high efficiency, stability and autonomy. This paper introduces a cluster 3D imaging signal processing system based on x240m5 blade server. The message queue communication (ZMQ) is used to realize the stable transmission of large data volume. At the same time, the mixed programming technology of C language and Matlab language combines the convenience of real-time and software integration, which greatly shortens the development cycle. The system runs stably and realizes the imaging recognition of the small spheres and their clump weights in the simulated target water.
Dynamic spectrum access strategy for cognitive wireless networks based on two channel sensing
Authors: Li Yanliang , Chen Dianjun , Zhang Luyong
Published: June 2019

A dynamic spectrum access strategy based on two channel sensing is proposed for the spectrum access model in multi-channel multi-user scenarios. The strategy reduces the contention of cognitive users to the channel by sensing the dynamic allocation of spectrum channels. The number of the perceptual access channels is adaptively allocated according to the number of access users, and the collision interference to the authorized channel is reduced. Then based on the above model, a hybrid dynamic spectrum access strategy is proposed, and the Overlay/Underlay hybrid access mode is adopted instead of the original single Overlay access mode. By setting the probability threshold to reduce the perception of the channel with lower credibility, the cognitive user adopts the Underlay access mode shared transmission at a lower transmission rate. The simulation results show that the proposed two dynamic spectrum access strategies can effectively reduce the collision probability and improve the network service quality.
Design and Analysis of Power Frequency Electric Field Sensing Unit with Reduce Edge Effect
Authors: Fan Liangjin , Zhang Wenbin
Published: June 2019

The performance of the electric field sensing unit determines the sensitivity, linearity and range of the electric field sensor. In this paper, a kind of alternating electric field sensing unit based on parallel capacitance was been introduced. And it analyzed the measurement principle of the parallel capacitive sensing unit. The structure parameters of the electric field sensing unit with equipotential ring were been designed by simulation, which reduced the influence of edge effect on the performance of the sensing unit. According to the measurement standard of power frequency electric field, the designed sensing units were tested under uniform electric field. And the influence of the sampling capacitances on the static characteristics of the sensing unit was been analyzed. The sensing unit with the best performance had a linearity of 1.6025% and a sensitivity of 248 mV/(kV/m). Its sensing unit had the characteristics of small volume, low production cost and it was easy to integrate and have mass production.
Error Tracking and Compensation Method Obtained by High-speed TV Measurement System
Authors: ShuHua Cui , Tiening Nie , Jun Liu , Haichen Lin , Yuanyuan Kang
Published: June 2019

Because the high-speed TV measurement instrument used to track and measure the vertical take-off section of the carrier rocket sometimes can’t provide the systematic error in the spaceflight test range, a systematic error compensation method is established succinctly and skillfully through spatial analytic geometric relationship by making full use of the rocket outline size, launch aiming direction and site parameters of each measuring station. An analysis on calculation results of actual task data shows that this error compensation method not only realizes the error correction purpose of tracking measurement instrument accurately, but also improves the flight trajectory and attitude calculation results of the carrier rocket at the same time, expanding the technology for systematic error correction method through optical measurement.
Research and Application of Low Voltage Ride Through Testing Device for Low Voltage Frequency Converter in Thermal Power Plant
Authors: Zaide Xu , Yang Liu , Jingmin Xu , Qi Xiao , Zhijie Zhu
Published: June 2019

In order to improve the Low Voltage Ride through (LVRT) level of the low voltage auxiliary frequency converter in the thermal power plant and effectively solve problems including the inaccurate drop time of voltage drop device, which is controlled by the switching structure of the traditional multi-winding transformer, excessive magnetizing inrush current occurs during the closing process, and the 30KW testing device for LVRT of the frequency converter in the thermal power plant is developed. It is designed with a three-phase four-wire back-to-back power electronic topology, together with adaptive fuzzy PI control algorithm. They can precisely set the voltage drop amplitude and time, ensuring automatic periodic cycle test controlled by upper computer. A LVRT field experiment has been carried out on low-voltage auxiliary frequency converter both before and after the transformation in a thermal power plant in Jiangxi Province. It proves that the dynamic response time of the power electronic voltage drop device is less than 5ms, the harmonic content in the converter voltage output is less than 0.5%. Additionally, the device boasts convenient operation and well-developed protection mechanism.
Design of Mathematical Model of Main Working Parts of Grain Combine Harvester
Authors: Wang Heng , Cao Shukun , Xu Xiangqian , Han Tao , Guo Hejia
Published: June 2019

In order to improve the working efficiency of the grain combine harvester, this paper decomposes the harvester into three parts: the power system, the walking system and the operating system. The paper determines the matching relationship between engine power and driving speed, corn harvesting speed, peeling speed and threshing speed. This paper determines the mathematical model of the main working parts by establishing a matching relationship. Based on the mathematical model, this paper designs the harvester simulation model by using Matlab and simulink software tools. In this paper, the effects of engine power simulation parameters on the speed, threshing and harvesting speed of the harvester in the mathematical model are studied. The results show that the harvester power increases, the walking speed of the harvester increases, the harvesting speed increases, the speed of corn peeling and threshing increases, and the loss of corn in threshing and clearing increases. The mathematical model of the harvester is very high and belongs to the large inertia system.
Humidity Sensor Based on Fiber Grating Coated with Graphene Oxide
Authors: Qiao Shuqi
Published: June 2019

Graphene oxide (GO) is a new two-dimensional carbon nano-material with large specific surface area and outstanding hydrophilicity. Its refractive index varies significantly with humidity, which can be used to improve the sensitivity of optical fiber humidity sensor. A kind of fiber Bragg grating (FBG) humidity sensor based on GO is proposed and experimentally demonstrated. GO is uniformly coated on the FBG surface by deposition. When the ambient humidity changes, the GO film adsorbs or releases water molecules and its refractive index changes. Thus the effective refractive index of FBG changes and the transmission wavelength also changes. The experimental results show that the sensor has a linear response of 2.53 pm/% RH in the range of 20%-70% RH, so it has the advantages of high sensitivity and simple structure.
Analysis and Simulation of Gradeability of Orchard Operation Platform Based on ADAMS
Authors: Hao Zhang , Guiju Fan , Zhao Li , Fu Qin , Xiaohan Sun
Published: June 2019

In view of the instability of the orchard machinery in the hilly terrain in China, this paper takes a crawler orchard operation platform as the research object. On the basis of mechanical design and theoretical analysis, the model is created by Solidworks and imported into ADAMS. It performs kinematics simulation and obtains experimental data of the machine running on a slope with a certain gradient. The simulation experiment sets the slope angle between 0° and 35°, and displays the climbing ability and working state of the orchard work platform by changing the driving force of the engine. The simulation results show that the orchard work platform designed in this paper can be used to carry out the work in the hilly area with large slope, which provides effective parameters for the improvement and actual operation of the machine.
Research on the Key Technology of the Automatic Piping Layout Design for the Launch Vehicle
Authors: Wang Teng , Nie Rongmei
Published: June 2019

For the low design efficiency and poor design quality in the piping layout design of the launch vehicle, the article raises a piping automatic layout method which is based on the geometry. In order to realize the piping automatic layout design, the method need the position coordinates and direction vector for both of the initial point and termination point. The article verifies the feasibility of the method by developing the piping automatic layout design system for the launch vehicle.
Dynamic Simulation Analysis of Flight Process of Bionic Aircraft
Authors: Wang Xinjie , Ning Yu , Wang Chen , Wang Caidong
Published: June 2019

In this paper, the beetle (Coleoptera) is taken as a bionic object. According to the characteristic of the hind wing of the beetle that can be folded, combined with the four-plate mechanism theory, a bionic flapping aircraft with four-degree-of-freedom beetle foldable wing is designed. It can realize flapping, gliding, wing folding and abduction/adduction movement with self-locking function. At the same time, the physical model of the beetle-folding four-plate wing was established. The dynamic simulation of the flight process was carried out in ADAMS. The variation of the force and torque of the flexible hinge at different flapping frequencies is analyzed. The results show that the force and torque of the hinge have nonlinear characteristics during the take-off phase, but they tend to be stable eventually. The force and torque of each hinge first decrease and then increase as the flapping frequency increases, and the time of fluctuations becomes smaller. The simulation results provide a reference for the parameter design of the flexible hinge and the control of the aircraft motion.
A Survey of Related Research on Compression and Acceleration of Deep Neural Networks
Authors: Long Xin , Ben Zongcheng , Liu Yan
Published: June 2019

Deep networks have achieved great success in many areas in recent years. However, with the increasing sophistication of deep neural networks (DNNs), the memory consumption and computational cost expand exponentially, greatly hindering their application in mobile devices and other limited resources. Therefore, there is impending necessity to consider model compression and acceleration without affecting the inference accuracy. In this paper, we review the recent popular techniques for compressing and accelerating deep networks. Those methods could be broadly divided into four categories: parameter pruning and sharing, low rank approximation, sparse regularization constraints and network weight low-bit quantization. The advantages and disadvantages of different compression and acceleration methods are also described in detail, other types of approach are also introduced in our paper, and future prospects for the field are given finally.
Spatial Distribution Pattern and Prediction of Pension Pressure in Provinces of China
Authors: Rendao Ye , Wang Dan
Published: June 2019

Along with China stepping into the aging society, pension pressure has become a social livelihood issue. This paper firstly defines the concept of pension pressure standing on the employment. On this basis, the research uses the spatial autocorrelation and standard deviation ellipse to study the spatial distribution pattern and evolution characteristics of pension pressure. Furthermore, the study constructs the GM (1,1) model to predict the trend of pension pressure. Based on the data collected from 31 provinces from 1995 to 2016, it found out that the pension pressure in China shows a slow upward trend generally. The growth of the pension pressure has a spatial agglomeration effect, and the pension pressure is characterized by a general pattern of divergent spatial distribution, mainly in the East-West direction and supplemented by the North-South direction. In addition, the future distribution pattern of pension pressure in China will shift from “Northeast to Southwest” to “North to South”, and it will basically become stable in the future.
Discussion of College and University Laboratory Safety Management System Using Blockchain
Authors: Bai Yu , Chen Zhiyu , Liao Liumei , Li Liping , Liang Sheng , Wang Junyang , Chen Jun , Ouyang Bocheng
Published: June 2019

Laboratory safety management in colleges and universities is an important task in daily management. It is related to the life safety of teachers and students and the safety of state property, and it guarantees the normal progress of experimental projects and experimental teaching. Constructing a laboratory safety management system (LSMS) is an important way to realize the informatization and modernization of laboratory safety management. An efficient, reasonable, convenient, and open LSMS can prevent accidents, effectively supervise the disposal of wastes, and stimulate the passion of teachers and students for experiments. In this work, an LSMS based on a blockchain model is presented. By integrating safety education, equipment management, waste disposal management, and other aspects into an organic arrangement, it can be effectively implemented and provide reference for the application and implementation of blockchain technology in the field of safety management.
Influence of Welding Parameters on Weld Formation and Microstructure of Fiber Laser Beams Welded T-Joint of Aluminium Lithium Alloy
Authors: He Enguang , Chen Li , Luo Kun , Xu Fei
Published: June 2019

This paper focused on the welding 1.2 mm thick 2A97 aluminium lithium (Al-Li) alloy plates in T-joint form using fiber laser with ER2319 aluminium filler wire. The effects of welding parameters on the T-joint weld appearance, microstructure and the joint mechanical properties were studied systematically, and the influence of welding parameters including the incident beam position and the incident beam angle. The weld shape, microstructure, hardness of the joint were evaluated by optical microscope and micro-hardness test. A uniaxial tensile test was conducted to obtain the tensile property of welded joints. At the optimized parameters, the welded T-joints showed good weld shape without macro defect. The significant softening occurred at the weld zone of the T-joints, and the micro-hardness of the weld ranged from70 to 85 HV0.2. The tensile strength was about 432 MPa, and the fracture mode of tensile specimens of T-joints was mixed.
Research on Beam Structure Damage Identification Method Based on Time Domain Response Sensitivity Analysis
Authors: Lin Lizong , Chang Haoyuan , Zhang Xin
Published: June 2019

A method for damage identification of beam based on time domain response sensitivity is proposed. The damage of the beam is regarded as the reduction of Young’s modulus, and the damage of the beam structure is detected by comparing the difference in displacement response between the undamaged-beam and damaged-beam. At the same time, the derivation and establishment of sensitivity matrix and the solution of sensitivity equation were introduced in detail, and the accuracy of the method was verified by software such as ABAQUS and MATLAB. Numerical analysis shows that the sensitivity analysis method has the advantages of simple operation, less measuring points and high precision. Quantitative measurements can be achieved for single damage conditions. Meanwhile, positioning measurements can be achieved for multiple loss conditions.
Study on heat treatment process of welded plates of VW75 magnesium alloy
Authors: Li Yongjun , Lu Chunfang , Zhang Kui , Liu Xiaodao , Wang Shengqing , Teng Hang , Ma Minglong
Published: June 2019

In this paper, microstructure and mechanical properties of welded plates of VW75 magnesium alloy under different heat treatment conditions were studied. The results show that the eutectic microstructure along grain boundaries of weld zone all could decompose when the welded plates of VW75 magnesium alloy were heat treated at 480°C, 500°C and 520°C conditions. With increasing of solution temperature and solution time prolonging, the eutectic microstructure along grain boundaries of weld zone were dissolved more fully. When the welded plates of VW75 magnesium alloy were treated at mentioned above temperatures, the grain size of base metal all increased dramatically during the initial solution treatment. The average grain size of base metal increased from 13um to 50 ∼ 60um just for half hour. With increasing of solution temperature and solution time prolonging, the average grain size of base metal was continuously increased obviously to 80um. Compared with the process of aging treatment after solution, directly aging treatment at 220° for 10h was more benefit to maintaining the strength of the welded plates of VW75 magnesium alloy.
Fabrication and Thermoelectrical Power Factor of n-type Si85Ge15 Alloys
Authors: Xu Yadong , Ge Huichao , Dong Huiling , Dong Shufeng
Published: June 2019

N-type Si85Ge15 alloys heavily doped with different dopant over a wide range of dopant have been fabricated by hot isostatic pressing. Influences of the carrier concentration and mobility of heavily doped n-type Si85Ge15 alloys on the thermoelectrical power factor are investigated. The experimental results indicate that thermoelectrical power factors of 31-38μWcm −1K −2 could be consistently achieved with carrier concentrations of 2.0-3.0 × 10 cm-3 and carrier mobilities of 35-42 cm 2 V -1 s -1, However, many samples with suitable carrier concentrations do not always have high mobilities and high power factors. Some possible explanations for this behaviour are presented.
Research on the Effect of Vulcanizing Agent and Vulcanizing Process on the Properties of Sealing Gasket
Authors: Du Peng , Wang Xinning , Tuo Jianzhi , Wang Yongyan , Xie Sujiang
Published: June 2019

Rubber plays the role of elastic adhesive in the preparation of compressed rubber sheet gasket reinforced by non-asbestos fibre, and it has an effect on the comprehensive performance of gasket. The performance of rubber is influenced by the choice of vulcanizing agent and vulcanizing process parameters. Therefore, the tensile strength, compression-resilience, creep relaxation and leak rate of the non-asbestos gaskets are affected. By adjusting the ratio of vulcanizing agent and vulcanizing process, the properties of the gaskets were compared. The results show that the gasket developed by using the experimental results has excellent performance.
Research of heavy wall X65MOS submarine pipeline steel key process strategy
Authors: Ding W H , Li S P , Zhang H , Ma C W , Li Q , Wang X S
Published: June 2019

In recent years, there has been development of several significant pipeline projects for the transmission of oil and gas from deep water environments. The production of gas transmission pipelines for application demands heavy wall, high strength, good lower temperature fracture toughness, low yield ratio and good corrosion resistance. To overcome the difficulties of producing excellent performance in heavy wall X65MOS pipe Shougang Steel Research in cooperation with the Shougang Steel Qinhuangdao China (Shouqin) 4.3m heavy wide plate mill research was conducted.

This paper describes the background, composition design, key process strategy to produce excellent performance in heavy wall X65MOS plate. The importance of recrystallized rolling process, the tensile property change during pipe making and the corrosion resistance change by “pre-stretching + bend” deformation simulate pipe making in the lab will be discussed. The results showed the per pass reductions during recrystallized rough rolling should be increased in a steady fashion, with special emphasis on the reduction of the final two roughing pass prior to the intermediate hold (transfer thickness for finishing) should be more than 20%. The tensile properties change rule and the reasonable pipe expansion process should be determine during pipe making. The crack length ratio(CLR) internal control criteria of the plate should be less than 6%, it helps to ensure the HIC performance of the pipe can meet the technical specification(CLR≤15%).
Preparation and Superficial Characteristics of Light-Cured Resin Containing Negative Ion Powder
Authors: Zhu Jingli , Ding Lili , Shi Jiatong , Liu Bin
Published: June 2019

The objective of this paper is to prepare light-cured resin material containing negative ion powder, test and evaluate the performance of its composite material, and provide some experimental basis for its clinical application. Adopt mechanical agitation dispersion and ultrasonic dispersion for ultra-fine processing of negative ion powder. Prepare the antibacterial composite resin by evenly dispersing negative ion powder in 4% ratio of 0% to 2% in Durafill composite resin. Observe the dispersion uniformity of antimicrobial agents by scanning electron microscope (SEM), and use Fourier transform infrared spectroscopy (FTIR) to determine the curing rate of the modified composite resin after adding different proportion of negative ion powder. Test the microhardness of modified composite resin by Vickers microhardness meter. The SEM result shows that the negative ion powder was dispersed uniformly in the composite resin. The results of initial curing rate of composite resin showed that the addition of negative ion powder did not lead to the decrease of curing rate but increased the curing rate to some extent. The mechanical properties test showed that the surface hardness was decreased compared with the control group, and it was gradually decreased with the increase of the proportion of negative ion powder.
Study on Job Analysis and Optimization of Solid Wood Puzzle Operation Based on Job Measurement
Authors: Gao Weixia
Published: June 2019

In this paper, three types of solid wood splicing are summarized: short material splicing, narrow material splicing and thin material lamination. The technological requirements of solid wood splicing are also summarized. On this basis, the work of jigsaw splicing is measured and analyzed by means of work sampling, and some suggestions for job improvement are put forward. Finally, the existing problems in the layout of jigsaw puzzle workplaces are analyzed and improved according to the principles of importance, frequency, sequence and functionality.
An Extrusion die for parallel collection Al flat tube of automobile heat exchanger
Authors: Deng Rurong , Huang Xuemei
Published: June 2019

The structural characteristics of parallel tube aluminum flat tube profiles for automotive heat exchangers were analyzed. A new die structure is present, and a semi integral core structure is proposed. The selection of new die structure parameters is introduced, which included the selection of extrusion machine capacity, the layout of hollow holes, the structure of the cores, the size of guiding holes, the structure of the welding chamber and the bearing of cores and the die hole etc. The practice shows that the new structure can effectively prevent the premature fracture of the cores and greatly improve the service life of the die.
Eye state recognition method for drivers with glasses
Authors: Geng Lei , Yin Haibing , Xiao Zhitao , Xi Jiangtao
Published: June 2019

Eye state recognition is a key step in fatigue detection method. However, factors such as occlusion of different types of glasses and changes in lighting conditions may have some impact on eye state recognition. In order to solve these problems, a driver’s eye state recognition method based on deep learning is proposed. Firstly, the driver’s face images are acquired using an infrared acquisition device. Secondly the multi-task cascaded convolution neural networks are used to detect the face bounding box and feature points of the driver’s face image, and then the eye regions are extracted. Finally the Convolution Neural Network (CNN) is adopted to identify the open and closed state of the eyes. Experimental result shows that the proposed method can accurately identify the state of eyes and help to calculate the fatigue parameters of drivers.
Curing characteristics of bismaleimide/furan blends
Authors: Shi Zhen , Li Peng , Zhao Guizhe , Du Ruikui
Published: June 2019

The curing kinetics of the bismaleimiede/furan blending system is studied by differential scanning calorimetry (DSC) under dynamic conditions. When the content of bismaleimiede is 25wt%, the curing process parameters of the blending system are obtained by the extrapolation method of temperature-heat rate (T-β), that is, the gelation temperature, curing temperature and post-treatment temperature, thus providing a theoretical basis for the curing process of the system. The kinetic parameters of the system are calculated by using Kissinger equation and Crane equation, that is, apparent activation energy (Ea), apparent frequency factor (A) and reaction order (n), and then the curing kinetic model of the system is established according to the calculated kinetic parameters. The kinetic model is used to predict the curing reaction characteristics of the system under the same temperature and dynamic conditions.
Research Progress on Malignant Transformation Mechanism of Precancerous Diseases of Breast Cancer
Authors: Xia Dong , Ran Rui , Bobo Meng , Yan Fang , Yanfang Pan , Hong Li , Xiaoping Ying
Published: June 2019

Breast cancer occurs in the epithelial tissue of breast, which is one of the most common female cancers in the world. In recent years, with the improvement of people’s living standards, the incidence of breast cancer is also growing rapidly, so the prevention of breast cancer is very significant. At present, the etiology and pathogenesis of breast cancer are still unknown. Precancerous diseases are benign breast lesions with potential canceration, which may develop into breast cancer if they have not cured for a long time. This paper summarizes the latest research progress on the mechanism for malignant transformation of breast precancerous diseases in recent years, hoping to provide theoretical reference for basic research and early clinical diagnosis of breast cancer.
A Novel Effectiveness Inference Method of Communication Jamming Based on Combination Factors
Authors: Yunge Tang , Taotao Zhang , Li Li
Published: June 2019

This paper presents a method of communication jamming effectiveness based on jamming equipment, combat target and propagation environment, in order to solve the problem of limited external field test resources for comprehensive evaluation supportion. “Collect the real jamming signal and communication signal of typical test station environment, in order to simulate the jamming ability of jamming equipment under different propagation environment (terrain, object, meteorology), communication combination parameters (distance, power, modulation mode) and jammint combination parameters (power, bandwidth, type).”
Research and Application of Low Voltage Ride through (LVRT) and the Power Grid Adaptability Testing Device for Frequency Converter
Authors: Zaide Xu , Yang Liu , Jingmin Xu , Qi Xiao , Zhijie Zhu
Published: June 2019

In order to study the response characteristics of converters applied in the field of renewable power integration and motor speed regulation when grid fault appears, the traditional LVRT schemes and effects of converters are analyzed, and the integrated design of AC and DC sources scheme based on power electronics technology is proposed.The three-phase four-wire topology AC and DC sources and adaptive fuzzy PI control algorithm is adopted to realize the real-time adjustment of the DC output voltage and dynamic control of the three-phase or single-phase AC output voltage. Meanwhile, the dynamic control includes the drop amplitude, the drop time, the frequency, and the Harmonic. The 40KW LVRT and grid adaptability testing device for converter is developed. The laboratory test proved that the dynamic response time of the device is less than 5ms, the harmonic content of the AC output voltage is less than 1%, and the protection mechanism is complete and reliable. The upper computer sets parameters offline or online, tests circularly and operates conveniently.
Research on Prediction of Equipment Maintenance Outlay Based on Linear Regression
Authors: Feng Zhang , Bing Chen , Shouquan Wang , Gaolun Cui , Weibo Guo
Published: June 2019

The equipment maintenance outlay is analyzed and predicted with R language statistics analysis software based on linear regression. The analysis results accord with the objective reality. Thus the method is proved practicably.
Method and Research on Detecting Unknown Frequency Signal in Duffing Oscillator Detection Blind Zone
Authors: Huang Ji-yao , Chen Chang-xing , Ling Yun-fei , Lin Xiang-yang , Sun Hao-xiang
Published: June 2019

In view of the problem of blind area in detecting weak iso-frequency signals of Duffing oscillator, an anova technique is proposed to detect the signal in blind area.By analyzing the condition of detecting blind area, the range of phase of the signal to be measured with the same frequency is obtained, and the variance calculation of the chaotic system and the signal to be measured is realized.The feasibility of the method is proved by experiments.It can also detect the existence of difference frequency signal.The results show that this method is a signal processing method with a lower threshold of SNR, which provides a basis for weak signal detection.
Design and Research on FBMC-OQAM Multicarrier Technology for 5G
Authors: Yao Ling , Wang Enliang , Peng Xia
Published: June 2019

Aimed at the low frequency utilization of OFDM due to adding cyclic prefix, a FBMC-OQAM system design based on frequency sampling prototype filter is proposed. In this paper, the performance difference between FBMC-OQAM and OFDM is studied by building the system model and the effect of the overlap factor of the prototype filter on the performance of multi-carrier technology in FBMC-OQAM system is also studied. It is verified that the system has high frequency utilization and good out-band suppression ability and it has good application value in 5G system.
Non-uniform Illumination Image Enhancement Based on Retinex and Gamma Correction
Authors: Xia Haiying , Liu Min
Published: June 2019

Since ambient light or reflection from the surface of the object, the phenomena of none-uniform illumination exist in images.At present, some problems may appear in the image after the non-uniform illumination image processed by conventional algorithms, such as unnatural, the compressed dynamic range of brightness and halo artifacts in strong edge.To effectively process none-uniform images, the image enhancement based on Retinex theory and gamma correction was proposed.First, the bilateral filter is used to decompose the original image into an illumination and reflectance, to avoid halo artifacts in the reflectance.Second, Gamma correction and are used to equalize the dynamic range of brightness and extended brightness.Finally, the reflectance and the illumination are re-fused to restore the detail and naturalness of the image.The experimental results show that the proposed method effectively enhances the image and maintains the naturalness of the image.The objective evaluation index and computation time are also significantly better than other algorithms.
Research on domain terminology recognition based on dependency tree-conditional random field
Authors: Lin Yanyan , Lu Jieping
Published: June 2019

In view of the inconsistency of Chinese patent information in manual marking and classification, which leads to problems such as missed detection, partial detection and noise of patent search, this paper proposes a method based on the dependency tree-conditional random field(CRF) identification field terminology. The method is based on the modern grammar theory of dependency, using the existing technology to mark the dependency relationship. Finally, the corresponding technical feature words are identified in the results of the dependency labelling, and the training data is used as the training data to train the conditional random field model to identify the domain terminology. The experimental results show that the acquisition of training data through the dependency tree can improve the accuracy, recall and F value of the recognition results.
Adaptive context-aware correlation filter target tracking
Authors: Zhou Saijun , Zhang Chengwang , Xiong Xuying , He Ran , Qiu Jingang
Published: June 2019

Aiming at the problem that the traditional correlation filter target tracking algorithm has low tracking accuracy under the conditions of fast motion, occlusion and complex background, an adaptive context-aware correlation filter target tracking algorithm is proposed in this paper. On the basis of the relevant filtering algorithm, the boundary effect and fixed learning rate brought by cyclic displacement are improved as the main purpose. Firstly, an adaptive sampling strategy based on the extreme value of the response graph is added to the context information in the training stage of the classifier. Then, A piecewise learning rate adjustment strategy is utilized to make the algorithm better adapt to the target change. Finally, the performance of the algorithm is verified by the standard data set. The experimental results show that the proposed algorithm improves the tracking accuracy of DCF and SAMF algorithm respectively. It not only has good robustness in the case of fast motion, occlusion, complex background, etc., but also can be integrated into most relevant filtering algorithms as a framework.
A study on the presentation and influence of pan-anime culture in Chinese animated films
Authors: Liu Baiheng
Published: June 2019

Taking the influence of pan-anime process on the animation creation and animation industry in China as the research object, through the multi-angle analysis of the trend in the works in recent years by domestic animation creators, the study attempted to provide some advice for integrating pan-anime culture more naturally into the creation of the current domestic animation film and narrative mode and provide some help for catering to the preferences of pan-anime audience under the new pattern.
The research on multiuser resource allocation optimization in cognitive radio
Authors: Hu Guangyao , Zhang Luyong , Chen Dianjun
Published: June 2019

Spectrum resource allocation optimization is still a research hotspot in the field of cognitive radio. The optimization framework based on Bandwidth-Power Product (BPP) proposed in recent years provides a new direction for this field. Compared with the traditional waterfilling algorithm, the new optimization framework has effectively improved the utilization of spectrum resources. However, there are few further studies on BPP in recent years. Based on the work of predecessors, this paper improves the criterion of BPP by taking into account the impact of the multiplexing of spectrum resource in different spatial locations on the spectrum utilization. The simulation results show that the improved BPP framework can further improve the utilization of spectrum resource; besides, the framework is more in line with the actual cognitive radio environment.
Control Strategy of Central Air-conditioning Load Participate in Peak Adjustment
Authors: Hong Lin , Nate•saierjiang San
Published: June 2019

At present, the proportion of air-conditioning load on the user side is increasing, and the air-conditioning loads have the ability to store thermal energy. By reasonable controlling air-conditioning loads to participate in peak adjustment, the potential of air-conditioning load regulation can be effectively played. In this paper, a temperature control model of central air-conditioning loads is established based on the calculation method of building cooling load. Fully the periodic paused control strategy for central air-conditioning load is proposed to release the conflict between electricity supplying and demanding in the period of peak load, considering the heat storage and heat dissipation characteristics of buildings and the heat dissipation characteristics of changing flow rate of people, without affecting or less affecting the users comfort. Then, taking a business district as an example, the feasibility of temperature control model of central air-conditioning and the hierarchical strategies periodic paused control strategy is verified.
A Design of Road Lifting Blind Device and Finite Element Analysis
Authors: Li Y Q , Lv X C , Dai J
Published: June 2019

The visually impaired cannot identify the traffic signal lamp accurately in the existing road intersection, because there is no effective blind guidance system. In view of the problem, a new lifting blind device was designed in this paper, which contains device structure and control system. Three-dimensional modeling and stress situation of the device were analyzed through Solidworks, the results showed that the structure and material selection of the blind track lifting device could meet the requirements. Because the device is simple, reliable and efficient, it is conducive to popularize and applicate.
Research on LCL-filtered Grid-Connected Inverter Based on Fractional Order PI Controller
Authors: Yini Zhou , Hejin Xiong
Published: June 2019

With the high attention paid to new energy sources, grid-connected inverters with LCL filter have been widely used. In order to maintain the steady state operation of the system and reduce the resonance, the current double closed loop control decision with a PI controller is often adopted. However, the PI controller has only two adjustable parameters, Kp and Ki, and the adjustment accuracy is limited. This paper focuses on the simulation of the lightning interference and humid environment that inverters may face after being put into use in outdoor open space, such as solar power stations and so on. Since the fractional-order PI controller has three adjustable parameters, it can effectively improve the system performance and make the output more in line with the actual application requirements. Therefore, this paper selects the fractional-order PI controller and compares with the control performance of the traditional PI controller. Finally, the conclusion comes out that the system based on fractional order PI controller has stronger anti-interference ability and better robustness.
Design and Implementation of spacecraft component-level test management system
Authors: Zhang J , Zheng H M , Lu T , Guo W , Chen A R , Liu Y
Published: June 2019

This article is to introduce the typical performance and configuration of component-level environmental test management system. Firstly, the characteristic of spacecraft component-level environmental test is analyzed and the main problems are pointed out. In order to address the shortcomings, the project of the test management system has been envisaged. Then, the composition, structure and implementation method are described. Results show that the management system solves many problems after its application. The system has the function of key parameter monitoring and a timed automatic inspection. It reduces the strength of the workforce and improves the quality of process control. The data packs of the product are enriched too. This system unifies the device drivers and communication methods of multiple manufactures, and completes the whole process automatic control of mechanics, thermal and comprehensive environmental tests. The system adopts the idea of modular design and has the function of convenient expansion. It has been deployed in many laboratories and can be promoted to other industries in the future.