bluuebunny/crossref_metadata_2025 huggingface dataset:
Stance in unpublished student writing
Authors: Becker Kimberly , Feng Hui-Hsien
Published: February 2020

This exploratory study investigates modal verbs
as stance features in the Physical Sciences sub-corpus of the
Michigan Corpus of Upper-Level Student Papers (MICUSP). The study
adopts Biber’s (2006)
stance framework, including modal verbs in three categories:
possibility, necessity, and prediction. Focusing on one feature
within one sub-corpus afforded closer consideration of the units of
analysis (discipline, level of study, nativeness, and register) that
could contribute to variation in the use of modals as stance
features. The findings show that possibility and prediction modals
are the most common in the Physical Sciences sub-corpus. The study
provides a description of student academic writing and considers
future research directions and pedagogical implications of stance in
Physical Science disciplines, student levels, nativeness, and
registers.
Enhanced strength-ductility of medium Mn steel by quenching, partitioning and tempering
Authors: Cai Minghui , Huang Hongshou , Zuo Xiurong , Ding Hua , Stanford Nicole
Published: February 2020

A quench and partition (Q&P) process was combined with tempering in a medium Mn steel. The partitioning treatment enriched the austenite in carbon, and stabilised the austenite against transformation during cooling. The ductility of Q&P steel is significantly improved by tempering, with negligible loss in strength. The ductility was found to be determined by the martensite in the structure, rather than the austenite in the present case. The reason for the significant improvement in the ductility with tempering was suggested to be the reduction in the dislocation density after extended tempering treatment. The energy absorption of this alloy was increased to 28.5 GPa·% together with an ultrahigh tensile strength ∼1400 MPa, which is one of the largest observations in this system.
The protective effect of Hederagenin on pulmonary fibrosis by regulating the Ras/JNK/NFAT4 axis in rats
Authors: Ma Wenjing , Huang Qingsong , Xiong Guofu , Deng Lijun , He Yan
Published: February 2020

As a respiratory disease with high morbidity and mortality, pulmonary fibrosis (PF) has been a serious threat to people’s health. Hederagenin (HDG) is a pentacyclic triterpenoid saponin widely distributed in various plants. This study explored the role of HDG in Bleomycin (BLM)-induced PF and the molecular mechanism. The results showed that HDG reduced BLM-induced pulmonary dysfunction, pathological damage in a dose-dependent manner. Besides, HDG reduced BLM-induced collagen deposition by decreasing the levels of α-SMA, Collagen I and hydroxproline. Furthermore, HDG reduced the levels of inflammatory cytokines (TNF-α and IL-6), TGF-β1 and connective tissue growth factor (CTGF) in bronchoalveolar lavage fluid (BALF) or serum. Further mechanism analysis indicated that HDG inhibited the expression of Ras and phosphorylation of JNK and NFAT4 in a dose-dependent manner. However, the JNK pathway activator Anisomycin reversed this inhibitory effect. In conclusion, these findings suggest that HDG may be a potential target drug for PF therapy.
An alternative supply system for stump biomass – coarse grinding combined with sieving of the produced hog fuel
Authors: Anerud  , von Hofsten  , Eliasson
Published: February 2020

Transport costs are one of the major costs in the supply chain of stumps for fuel. Stump parts are bulky and it is impossible to achieve full tonnages on trucks and trailers even though the load space is completely full. The transport economy for stumps is also negatively affected by
the large amount of contaminants in the loads. Grinding the stumps at the landing and sieving of the produced hog fuel has the potential to increase load weights and reduce both the amount of contaminants and the transport costs. To evaluate such a system a series of studies were made. Results
show that coarse grinding and sieving reduced both moisture and ash content in the produced fuel, thus increasing the heating value per ton delivered fuel and transforming a soil contaminated material to an acceptable fuel. Transport payloads increased substantially compared to transports
of stump parts, but a transport distance of 110 km was needed before the coarse grinding system provided lower cost than the standard system with transports of stump parts and grinding at the heating plant. Further studies are needed to evaluate the total energy efficiency in the two
systems. Coarse grinding and sieving is a feasible way to increase fuel quality and improve transport economy. However, total costs will in most cases be higher than for the loose stump system which renders the method preferable only in cases where the sieving process converts a non-acceptable
material into an acceptable fuel.
Aurora B kinase is recruited to multiple discrete kinetochore and centromere regions in human cells
Authors: Broad Amanda J. , DeLuca Keith F. , DeLuca Jennifer G.
Published: February 2020

Aurora B kinase has a critical role in regulating attachments between kinetochores and spindle microtubules during mitosis. Early in mitosis, kinase activity at kinetochores is high to promote attachment turnover, and in later mitosis, activity decreases to ensure attachment stabilization. Aurora B localizes prominently to inner centromeres, and a population of the kinase is also detected at kinetochores. How Aurora B is recruited to and evicted from these regions to regulate kinetochore-microtubule attachments remains unclear. Here, we identified and investigated discrete populations of Aurora B at the centromere/kinetochore region. An inner centromere pool is recruited by Haspin phosphorylation of histone H3, and a kinetochore-proximal outer centromere pool is recruited by Bub1 phosphorylation of histone H2A. Finally, a third pool resides ~20 nm outside of the inner kinetochore protein CENP-C in early mitosis and does not require either the Bub1/pH2A/Sgo1 or Haspin/pH3 pathway for localization or activity. Our results suggest that distinct molecular pathways are responsible for Aurora B recruitment to centromeres and kinetochores.
Chemical radiation dosimetry in magnetic fields: characterization of a Fricke-type chemical detector in 6 MV photon beams and magnetic fields up to 1.42 T
Authors: Trachsel Maria A , Pojtinger Stefan , Meier Markus , Schrader Markus , Kapsch Ralf-Peter , Kottler Christian
Published: February 2020

In magnetic resonance guided radiotherapy (MRgRT) radiation dose measurements needs to be performed in the presence of a magnetic field. In this study, the influence of magnetic fields on the readings of a Fricke detector, a chemical dosimeter, have been investigated in 6 MV photon beams. This type of detector has been chosen, as the Federal Office of Metrology (METAS, Switzerland) has great experience with Fricke dosimetry and since it is not expected that this detector is greatly affected by the presence of a magnetic field.

Magnetic fields with field strengths between 0 T and 1.42 T were applied during the detector irradiation. In a 5  ×  10 cm2 irradiation field, the Fricke readings are affected less than 0.9% by the applied magnetic fields. Taking the altered dose distribution due to the magnetic field (

) into account, the magnetic field correction factors (

) for the Fricke detector at 0.35 T and 1.42 T are determined to be 0.9948 and 0.9980, respectively. These small corrections hardly exceed the measurement uncertainties. Hence, we could proof that the Fricke detector is not significantly influenced by the presence of a magnetic field.

The Fricke detector was also tested for the feasibility of measuring output factors in the presence of magnetic fields. For irradiation field sizes larger than the detector (>2  ×  2 cm2), comparable results were obtained as for other detectors. The output factors decrease when a magnetic field is applied. This effect is more pronounce for larger magnetic field strengths and smaller irradiation fields due to shifts of the depth dose curves and asymmetry of lateral dose profiles.
Research on hierarchical differentiation intelligent examination method for operational health of low voltage distribution network
Authors: Han Haian
Published: February 2020

The operational health assessment of the Low-voltage Electricity District is the basic task of grid and refined management of low-voltage distribution network. Considering of the large number of stations and the lack of standardized management constraints, using the big data platform and multi-source heterogeneous data management technology, a kind of intelligent medical check-up method for the health of district station is proposed. Firstly, the self-organizing neural network clustering technology is used to classify the station area into 15 categories, which must take into account of geographical attributes, economic attributes and so on. Then, for each major type of area, the analytic hierarchy process is used to realize the subjective weight of the differentiated subject indicators. The entropy weight method is used to realize the objective weight of the three-level subdivision index, and the distance map method is used to realize the percentile mapping of the three-level subdivision index. Finally, the subjective and objective comprehensive weights are given to get the running health score of the station. Based on the actual platform data of a power supply unit in Shan Xi Province, the accuracy of the confusion matrix of the health classification of the station is about 92%, which verifies the effectiveness and applicability of the method.
Research on fault feature extraction method of rolling bearing based on improved wavelet threshold and CEEMD
Authors: Yang Lixiang , Hu Qinghe , Zhang Shuang
Published: February 2020

Because bearing fault feature information is not easy to extract in noisy background, this paper proposes an improved rolling bearing fault feature extraction method based on combination of wavelet threshold and complementary ensemble empirical mode decomposition (CEEMD). Firstly, the improved wavelet threshold denoising method is used to reduce the noise of the vibration signal, and the impact characteristics in the signal are enhanced. Then, the CEEMD decomposition is used to obtain a set of Intrinsic Modal Functions (IMFs), and IMFs with larger kurtosis and correlation coefficients are selected for signal reconstruction. At last, the envelope spectrum analysis of reconstructed signal is carried out to extract fault characteristic information. Through the experimental analysis of the vibration signals of the outer ring and inner ring of the rolling bearing, it is proved that this method can effectively extract the fault characteristics of the bearing.
The Equivalent Relationship between Space Vector and Carrier-based PWM Modulation Strategy in Current Source five-level Inverters
Authors: Cheng Ruiqi , He Yingjie , Deng Qinrui , Wang Yue , Guo Haoting
Published: February 2020

In order to achieve equivalent modulation of the three-phase five-level current source converter, this paper, based on the topology of three-phase five-level current-source converter, proposes a new method to realize the output characteristic of SVPWM with CBPWM, and this method can be applied in any space vector modulation sector of the topology. Different from the strategies of traditional unity theory, the proposed method decomposes the modulated waves directly according to the switching states of SVPWM in five-level current source converters and compare the sub-modulation waves with two inverting carriers. Finally, a simulation on MATLAB is carried out to verify the correction of the method.
Design and Optimization of Magnetic Coupled Resonant Wireless Power Transfer System at Weak - coupling Region
Authors: Song Dawei , Shi Fengdong , Liu Wei
Published: February 2020

Frequency splitting is one of the hot topics in the research of magnetic coupling wireless power transfer technology. Its purpose is to improve the transmission efficiency by eliminating the frequency splitting at the over-coupled region of the system. Frequency splitting does not occur at the weak coupling region. The transmission characteristics of the system in weak-coupled region are also of research significance. The mathematical model of the system’s transmission characteristic was established by equivalent circuit theory. Several key factors that affect the transmission characteristics of the system, self-inductance of the coil, mutual inductance between the coils, load resistance and so on, were obtained. A magnetically coupled resonant wireless power transfer system is designed and A method of coil design is proposed. The transmission efficiency of the system at the weak-coupling region was improved by optimized the design of the coil. Simulation and experimental results had good consistency. The results show that the transmission performance of the system at the weak-coupling area was improved.
Fiber optic gyro signal denoising based on variational mode decomposition and adaptive noise cancellation
Authors: Huang Chunfu , Li An , Qin Fangjun , Wang Zhi
Published: February 2020

The output signal of the fiber optic gyro (FOG) often contains a large amount of noise, which makes it difficult to model and calibrate. Therefore, it must be denoised. In this paper, an adaptive noise cancellation method based on variational mode decomposition (VMD) is proposed. The FOG signal was decomposed into a series of mode components with different center frequencies, and the correlation coefficient method was used to determine the number of decomposition layer. The low-frequency signal and the high-frequency noise components were distinguished by the frequency distribution of each component. They were respectively accumulated to use as the ready denoising signal and the reference noise, then obtaining the denoised signal by adaptive noise cancellation. Using FOG measured data, the proposed method was taken into experiment compared with traditional methods. Allan variance analysis verified that the proposed method effectively suppresses the noise in the FOG signal.
Selection Method of Test Pulse Width and Amplitude to Avoid Self-heating Effect of Power Devices
Authors: Li Jinyuan , Wei Lei , Li Yaosheng , Guo Chunsheng
Published: February 2020

The objective of this study was to address the deviation of electrical parameters, which is caused by the self-temperature rise effect of power devices in electrical testing processes. The pulse width and amplitude of the device test were considered as the research object. The three-dimensional variation of the power, junction temperature, and pulse width of semiconductor power devices were investigated using the principle of electrical temperature measurement, and the three-dimensional variation surfaces of the power, junction temperature, and pulse width were established. A method for selecting the pulse width and amplitude of the test to avoid the self-temperature rise of the power device is proposed. This method uses cutting projection to obtain the characteristic curve of the pulse width and power change, and selects an appropriate two-dimensional region of the pulse width and power to avoid the self-temperature rise of the power device. Moreover, the proposed method can be used as a reference when selecting a pulse test method.
Charging Strategy of Supercapacitor in Photovoltaic Power Generation System
Authors: Guo Kunli , Dong Yan , Fu Jianzhe
Published: February 2020

The charging efficiency of supercapacitor under different charging methods is analyzed by using the improved RC model of supercapacitor. A photovoltaic cell charging system for supercapacitor based on Boost cascade Buck converter (BOCBB) is proposed. The former Boost converter is connected to the photovoltaic power generation system, and the conductance increment method is used to track the maximum power point of the photovoltaic cell. The latter Buck converter uses a segmented charging strategy to charge the supercapacitor. Based on this circuit, a complete control method for the supercapacitor charging system is proposed. Finally, the charging efficiency of supercapacitor by photovoltaic cells under different lighting conditions is simulated and analyzed.
Design of a Broadband LNA with Multi-feedback Using 70nm GaAs MHEMT Process
Authors: Guan Jin , Gong Min , Gao Bo , Zhang Ran
Published: February 2020

This paper presents a broadband LNA using 70nm GaAs MHEMT process operating from 1.5GHz to 20GHz. The multi-feedback technique and input/output impedance match are applied to compensate the transistor gain roll-off with frequency and optimize the stability and reflection coefficients. The effect of the multi-feedback technique for stability, noise figure, gain flatness, linearity, and S-parameter performance are analyzed and discussed. Among the whole bandwidth, this LNA features gain of average 29.5dB increasing with frequency and noise figure of average 1.15dB. This LNA also achieves good reflection and isolation performance. The consuming of this LNA is blow 150mW and the chip area is less than 1.4mm*0.8mm. The figure-of-merit (FOM) is about 362.6 (GHz/mW). This LNA could be found its application in high data rate transmission, software defined radio, 5G communication, test instrumentation, wideband radar and other wideband systems.
Research on Electric Micro-Meteorological Monitoring and Early Warning System
Authors: Zhang Zehao , Yu Zhen , Xu Xiyuan , Guan Cheng , Zhang Song
Published: February 2020

This paper studies and analyzes the influence of micro-meteorological disasters on power system, points out the main problems in the establishment of power micro-meteorological monitoring and early warning system, puts forward the system architecture of power micro-meteorological monitoring and early warning system, which provides a reference for the establishment of power micro-meteorological monitoring and early warning system.
Electric Field Signal Recognition Method of DS Switching Operations Based on Wavelet Packet Analysis and PSO-HSVM
Authors: Yi Tongqiang , Xie Yanzhao , Zhang Hongye , Liu Henan
Published: February 2020

In order to monitor the state of Gas Insulated Substation (GIS), this paper established a fault simulation experimental platform for Disconnecting Switch (DS), and collected data through a 3D radiation electric field (E-field) measurement system. For extract the feature parameters, four-layer wavelet packet decomposition was performed on the data to obtain normalized energy, and the dimension of the eigenvector was reduced by principal component analysis (PCA) algorithm. Then, the model was trained with the hybrid kernel support vector machine (HSVM) algorithm, and the parameters was optimized with the particle swarm optimization(PSO) algorithm. The result shows that compared with the traditional SVM model, the method proposed in this paper improves the diagnosis accuracy of DS defect signals.
Analytical Results to Fuel-optimal Spacecraft Formation Maneuver
Authors: Wang Nan , Gong Deren , Xu Guangtan , Duan Dengping
Published: February 2020

In this study, analytical results are obtained for fuel-optimal spacecraft formation maneuver, including initialization and reconfiguration. The method consists of two stages. The first is parameterization of the problem and a new form of the problem is developed for simplicity. Second, the out-of-plane and in-plane maneuver are studied with the help of a useful inequality introduced and proved, the lower bound of the fuel consumption and the corresponding constraints of the control forces are derived and obtained. The result shows that the minimum total fuel consumption depends on the relative size parameters, and that the existence of optimal control algorithms depends upon the initial conditions. Numerical simulation of application proved the validity and efficiency of the proposed method, which can also be utilized in the maneuver of PCF.
Analysis on the influence factors of operational test effectiveness
Authors: Bo Yun , Bai Hongbo , Wei Guojun
Published: February 2020

Operational test is the concrete embodiment of actual combat guidance in the field of weapon equipment test and evaluation. Based on the analysis of the operational test process, this paper summarizes the operational test requirements and components. Based on the interaction between them, 18 factors of 5 categories affecting the effectiveness of operational tests were analysed, provides a reference for promoting the follow-up operational test to be carried out more scientifically.
Research on the Source-Load Interactive Scheduling Strategy for Modern Industrial Parks
Authors: Haibo Tan , Kai Li , Mouhai Liu , Haiyuan Wang , Cong Tan , Zhiguo Liu
Published: February 2020

Aiming at the problems of diversified demand for electricity, high rate of load growth, limited distribution network corridor and single power supply mode in industrial parks, this paper explores a new scheduling strategy, studies a mechanism of source-load interactive scheduling for modern industrial parks, and puts forward three scheduling strategies, namely, optimal electricity price, friendly power grid and enhanced production. The strategy has been applied in a smart industrial park of Hunan Power Grid. The application results show that the method can effectively improve the power supply capacity of the modern industrial parks, reduce the total cost of electricity, and enhance the load rate of distribution transformers, and it also has high economic and practical value.
A Fast-transient NMOS Capacitor-less LDO with Spike Voltage Sampling Amplifier and Transient Enhancement
Authors: Li Yun , Huang Shengming , Duan Quanzhen
Published: February 2020

A fully-integrated NMOS low dropout voltage (LDO) with spike voltage sampling amplifier is proposed in this paper to provide a stable power supply for many portable devices and artificial intelligence systems. The proposed Spike Voltage Sampling Amplifier circuit is composed of an error amplifier based on dynamic bias of output voltage and a capacitive coupling network, which is embedded in the circuit to detect fluctuations in the output voltage to increase the slew rate of the power transistor so that it turns on and off quickly. The LDO is implemented in 0.18 um CMOS process, which consumes 84uA quiescent current. It regulates output at 1.6V, with dropout voltage of 200 mV. For load current transients from light load 100 uA to heavy load 20 mA at the 100 ns edge-time, the undershoot of the LDO is 82 mV and the recovery time is 167 ns. Similarly, the load current transient from heavy load to light load produces an overshoot of 67 mV and recovery time is 156 ns.
Summary of web crawler technology research
Authors: Yu Linxuan , Li Yeli , Zeng Qingtao , Sun Yanxiong , Bian Yuning , He Wei
Published: February 2020

With the continuous development of network information technology, there is a large amount of unstructured data called big data on the network. Human resources to collect information laborious, so web crawler technology came into being. This paper explores the basic principle and characteristics of web crawler and the classification of current popular crawler, introduces the key technology of crawler, compares two search strategies and the current application of crawler. Finally, the future research direction of web crawler is introduced.
Research on Early Warning of Power Grid Construction Safety Based on PSO-SVM Model
Authors: Sun Yuwei , Zhu Jianbao , Yu Xinchun , Ye Chao , Fan Guoxiang
Published: February 2020

Electric power system is an important symbol of China’s economic development, and electric power construction is an important way of electric power system. However, the potential safety hazards and safety accidents generated during its development have a great impact on economic and social development. In order to reduce the occurrence rate of such accidents, this paper proposes a power grid construction safety early warning model based on PSO-SVM. The quantitative model adopted by the traditional SVM safety early warning method has limitations in parameter optimization. The particle swarm optimization (PSO) algorithm is superior to the traditional method in parameter optimization because it cannot obtain better early warning effect. It uses the information sharing between the whole group and the mutual cooperation between individuals to search, thus searching for better parameter combination and achieving better early warning effect. Finally, the traditional SVM model test for power grid construction is compared, further proving the improvement of the model after improvement.
Research and Application of Integrated Energy Coordination Optimization Control in Distribution Network
Authors: Qi Wang , Hu Hao , Li Hui
Published: February 2020

In recent years, China’s new energy industry has developed rapidly, and photovoltaic and wind power installed capacity has ranked first in the world. However, at the same time of rapid development of new energy sources, the problem of consumption has become increasingly prominent, and the phenomenon of abandoning wind and abandoning light is serious. This paper will start from the power generation principle of distributed power supply and the charge and discharge mechanism of energy storage. Through the analysis of the characteristics of distributed power supply, the new energy consumption is the most, the thermal power input is the minimum, and the distributed power supply is established. The cooperative optimization model of distribution network is constructed, and the coordinated optimization control model based on distribution network automation technology is constructed, and the experimental simulation is carried out to obtain the optimal coordinated energy optimization control model for distribution network to realize the safety, high efficiency and high degree of regional distribution network.
Environmental protection analysis of thermal power units operating under unconventional conditions
Authors: Wang Shunjiang , Ge Weichun , Wei Mofan , Zhang Wuyang , Cao Lina , Lv Xuming
Published: February 2020

Aiming at the problem of optimal distribution of dust removal, desulfurization and denitrification load in thermal power plants, considering the cost of environmental protection, from the perspective of improving the comprehensive economic benefits of the whole plant, the relationship between coal consumption and power generation of the unit is described by using quadratic polynomial. Based on this model, it can be obtained. The unit corresponds to the fuel cost of different power. Considering the cost of environmental protection, the cubic polynomial is used to model the relationship between the pollutant concentration of the unit and the power generation of the unit. The total cost of peak shaving of the unit is calculated by the unit price of pollutant emissions in different periods. In addition, considering the efficiency of desulfurization and denitrification when the unit is operated under low load conditions, the concentration of pollutants in the exhaust gas is increased, which causes additional environmental costs of government fines, and a model of additional cost is proposed. Based on the actual operating data of the unit, a model for optimal comprehensive economic benefit was established and the constraints were established. And verify the correctness of the model.
Level Set for Semantic Segmentation with Edge Compensation
Authors: Lei Zhipeng , Zheng Wei , Miao Yongxin , Fei Xuan
Published: February 2020

This paper demonstrated that active contour based on points evolution is not suitable for Objects with blurring boundary segmentation. In irregular areas adjacent points have similar motion trends trapped into ‘piles phenomena’. Level set should be preferred in practice. Whereas, classic level set lacks of perception in distance especially narrow and abnormal region. Consequently, we reported an algorithm localized level set that is able to improve accuracy. Meanwhile, in cases lost boundary of bone, we gave a strategy called edge compensation. Depending on shapes of neighborhood slices, defective section is estimated and restored effectively. Our experiments showed that the algorithm localized level set increases segmental quality with precision 99.74%. Additionally, it could not only rectify mistakes brought by incorrect initialization but also have a robust performance to overcome local region with highly inhomogeneous intensity.
Research on Clock Source Correction Method based on Wireless Sensor Network and TPSN Network Protocol
Authors: Cui Jisheng , Liu Yunsong , Wei Kai , Cao Hanwen
Published: February 2020

By analyzing TPSN synchronization protocol and various uncertain factors, this paper summarizes the concept of wireless sensor network and the research status of clock synchronization technology in wireless sensor network. To solve the problem that TPSN did not estimate the clock frequency drift, a new idea of wireless sensor network development is proposed: the node local clock self-correction method. The average clock deviation index is designed to evaluate the clock accuracy in a synchronous period. The experimental results show that this method is easy to implement. The synchronization period can be extended, the synchronization cost can be reduced and the energy consumption can be saved.
Design and Application of Electronic Analog Relay Protection Device with Load Check
Authors: Li Yu , Li Yunzhi , Zhao Bo
Published: February 2020

This paper designs an electronic substation simulation relay protection device with load check. At the same time, the device is studied and applied in the new substation. First of all, this paper analyzes the primary wiring mode and three-phase symmetrical current and voltage in the primary side of a typical substation, and confirms the transformer ratio, polarity and wiring mode of the current/voltage transformer. Then, by checking the polarity of line protection, metering, bus protection, main variable differential protection and backup protection, the polarity error of metering circuit with load check protection and metering circuit is effectively avoided. Finally, through the field test verification in the new 220kV Fuxing station of Jinzhou power supply company, it is verified that the technology adopted in this paper can fully meet the requirements of substation simulation load test. The relay-protection device with load check designed in this paper solves the problem that the conventional electric-type single-phase large-current generator can only detect the transformer ratio and polarity of the relative single-phase loop current transformer, and the difference loop cannot be detected. It shortened the switching operation time of changing ratio, polarity and phase check of the primary and secondary circuits after passing the load of the substation transmission belt.
Research on missile overload control technology with prescribed performance
Authors: Haiyan Li , Junbao Wei , Jing Li
Published: February 2020

Considering that the present control methods for missile overload don’t take the transient and steady state with prescribed performance into consideration. On the basis of backstepping idea, a controller design method with prescribed performance is proposed for longitudinal channel overload motion model of missile in order to improve the performance of missile control systems. It is proved that the system is stable in the sense of Lyapunov, the tracking error of the system satisfy the prescribed transient and steady performance. The given simulation results demonstrate the effectiveness of the proposed control method.
Analysis of resistance characteristics of liquid flow in microfluidic channels
Authors: Zhang Min , Liu Xuling , Li Tienan
Published: February 2020

In order to investigate the resistance characteristics of liquid flow in microfluidic channels, the mathematical models of liquid flow resistance in microfluidic channels are established in this paper. The microfluidic channel samples with different parameters are designed and fabricated by using soft lithography technology. The effects of channel parameters of channel aspect ratio α, channel equivalent diameter d

l
and channel length/diameter ratio l / d

l
on liquid flow resistance are analysed and tested through experiments. This paper reveals the flow resistance performances in microfluidic channels and provides research basis for improving the flow characteristics and optimizing the microfluidic channel structures.
Research on Wear Recognition of Electric Worker’s Helmet Based on Neural Network
Authors: Sun Yuwei , Fu Jing , Ma Qingshan , Yu Xinchun , Fan Guoxiang
Published: February 2020

Head injury is an important cause of electric construction accidents. Wearing a safety helmet is an effective measure to prevent electric construction accidents, and in the work, unsafe behavior of workers without wearing a helmet often occurs. This paper proposes a neural network-based automatic cap wear automatic identification and detection technology to identify the behavior of unwearing helmets in power construction. In view of the shortcomings of the existing helmet detection scheme in the complex environment, such as low efficiency and low recognition accuracy, this paper selects the region of the neural network (Fast-er-RCNN) to identify the wearing of the helmet during the power operation. The overall scheme uses the target detection scheme based on the foreground detection technology to detect the target individual in the obtained video recording of the power operation. The Kalman filter algorithm is used to track the target in the video and solve the occlusion problem in the video image. Through the actual detection of power construction monitoring video, the availability and efficiency of the designed algorithm are verified. The target recognition accuracy can reach 85.7% and the recall rate is 87.5%.
High Voltage Transformer design based on Flyback Switching Power Supply
Authors: Chengcong Li , Zhenfang Fan , Hui Luo
Published: February 2020

The single source generator could change the frequency and duty cycle of the pulse to control the voltage of output in flyback switching power supply. A variety of methods and calculations could be used to design high voltage transformer, such as AP
method that will be used in this transformer, kg
method and KRP
method. In this paper, the process of how to select the magnetic core and the other parameters of the transformer will be discussed step by step. At first, the voltage of output will be over two thousand and five hundred voltage. The single source generator changing the frequency and duty cycle, the voltage of output will stay stability on five hundred voltage. The seize of the transformer is smaller than that has been used, so it will be beneficial for the circuit integrated.
Study on the detection method of the number of people passing through the wall based on IR-UWB
Authors: Wang Kunyu , Guan Ying , Luo Dan
Published: February 2020

The purpose of this study is to realize the detection of the through wall personal based on IR-UWB radar. The through wall detection system sends IR-UWB signal to the detection area, which can penetrate the wall and radiate to the detection area behind the wall. When transmitting or receiving IR-UWB signal, antenna array with a certain aperture is needed to achieve azimuth resolution. After receiving the echo signal, the IR-UWB through wall detection system stores or directly transmits the echo signal containing the target information to the signal processing platform for subsequent detection processing. This study can achieve the number of obstacle crossing and detection based on BP neural network, and can detect different numbers and different obstacles through two detection methods. The final experimental results show that compared with the traditional probability method based on maximum likelihood estimation, the probability of this method has been greatly improved, and the judgment effect has also been significantly enhanced. The achievements of this project can be extended to the fields of human and animal recognition, human health detection, intelligent medical treatment, intelligent home and so on, based on the protection of privacy.
Thoughts on the Application of Electronic Information Engineering in Electrical Engineering Automation
Authors: Bowen Lv
Published: February 2020

With the continuous development and improvement of information technology, the comprehensive utilization of electrical information technology, communication technology and electronic technology can promote the rapid development of electronic information engineering to a great extent. These will make electronic information engineering widely used in various industries. The application of electronic information engineering in the design process of electrical engineering automation system plays an important role in improving the level of automation and intelligence of electrical engineering. The analysis and research on the application of electronic information engineering in electrical engineering, and the discussion of the automation technology of electronic information engineering have important practical significance for promoting the development of electronic information engineering and the improvement of electrical engineering automation level.
Design and Implementation of Information and Communication Dispatching System Based on FreeSwitch Platform
Authors: Tang Wei , Jin Hai , Liu Kang , Liu Xu , Dong Wu
Published: February 2020

The thing of information and communication dispatching is a decision-making process and the core work of command centre. The accuracy and efficiency of information and communication dispatching work directly affect the service quality and corresponding social benefits. This paper first introduces the technology of FreeSwitch, a soft switch solution, including a soft phone and a soft switch to provide voice and chat product drivers. On the basis of demand research, the information and communication dispatching system based on IMS architecture, and the upper application based on SG-UAP platform were developed to realize voice dispatching, cooperative dispatching, recording, traffic service, configuration service and other functions. The system has also been deployed online. After continuous testing and drilling, the platform has been used in actual combat, marking the initial completion of the construction of the information and communication dispatching command system based on the FreeSwitch platform.
Abnormal Value Treatment and Seasonable Adjustment Method for Medium and Long-term Load Data
Authors: Li Xuxia , Wang Yao , Hu Yingying , Li Jia , Tong Xing , Liu Renhui
Published: February 2020

Since most of the data used for power demand early warning, forecasting and analysis is the original power data collected directly from the power system, the data cannot be directly applied to the specific analysis because of having two problems. First of all, because various errors will occur in the power data collecting and transmitting processes, some random factors may cause the power consumption data to fluctuate drastically in a short period. These errors or problem data that do not conform to the overall change rule of the power sequence may lead to wrong analysis results. Secondly, because the electricity sequence has obvious seasonal characteristics, and the inherent variation of the load sequence is often obscured by the seasonal variation factors, using the original data for analysis directly often fails to discover the inherent regularity of the electricity consumption data. Based on these two reasons, the original power data should be conducted with abnormal value processing and seasonal adjustment before the power demand early warning, forecasting and analysis.
Design of loading test bench for precision ball screw based on LabVIEW+PXI
Authors: Lu Pengcheng , Fan Yuanxun , Pan Weidong , Cao Dawei
Published: February 2020

In order to discuss the dynamic characteristics of the aerospace ball screw pair, the paper designs a loading test bench based on Labview+PXI platform and magnetic powder brake. The test bench can simulate the loading condition up to 10Hz. In structural design, magnetic powder brake is used to apply the loading force. In hardware design, the system is built by using upper-lower computer system architecture based on PXI bus. In software design, the program is written in LabVIEW, which mainly includes the data processing and display program in the upper computer and the data acquisition program, the motor control program in the lower computer (PXI). Finally, the test bench was built and the inertia loading test and the rated speed loading test were carried out. The test results verify the effectiveness of the high-frequency loading measurement and control system, and provide a reliable test platform for the dynamic characteristics of the ball screw pair under high-frequency conditions.
Forecasting Model Of Electricity Sale Market Based On User’s Electricity Consumption Information
Authors: Gao Shifa , Wang Ai , Wang Zhigang , Wang Zheng , Tong Xing , Liu Renhui
Published: February 2020

The prediction of electricity sale market is directly related to the balance of electricity supply and demand. The high-precision prediction method of electricity sale market will effectively avoid the imbalance of system supply and demand, and improve the security and economy of the system. In the past, it was difficult to obtain the information of users’ electricity consumption, so the prediction methods of electricity sale market in the past were based on the overall electricity sale. The advantage of this method is that it can get the forecast value of the future electricity sales quickly and intuitively, while the disadvantage is that it fails to consider the electricity development trend of all walks of life that compose the electricity sales in detail.
Research on Design and Simulation of Drive Power Supply Based on Linear Motor
Authors: Zhu Zihan , Zhou Jiemin , Zheng Gang , Zhu Yongwei
Published: February 2020

In many fields, such as transportation, logistics, aerospace industry, industrial automation, etc., linear motion is required. The traditional approach is to use a rotating motor, after a series of conversion mechanisms, and then push the load to make a linear motion. However, this method not only has shortcomings of low efficiency, low precision, high cost, slow response, but also causes a lot of energy loss during the motion conversion process. The emergence of linear motors has made these problems well solved. The driving power supply can provide a stable working voltage for the linear motor and keep the working state of the motor, so it is the core device of the linear motor.
Three-Phase Unbalanced Treatment Scheme Based on High-Speed Power Line Carrier
Authors: Huang Rui , Guo Guang , Chen Jianhua , Liu Mouhai , Liu Zhiguo , Yu Minqi
Published: February 2020

Most of the low-voltage distribution networks are three-phase four wire systems. Because of the quantity and dispersion of single-phase power users, the three-phase load unbalanced problem exists in a large number of low-voltage stations. With the continuous increase of power consumption level of the majority of power customers, the three-phase load unbalanced has become increasingly prominent in low-voltage station area. In this paper, the mechanism of three-phase unbalance generation and the defects of traditional treatment methods are introduced. On this basis, a three-phase unbalanced treatment scheme for low-pressure station area is proposed. The scheme can test out three-phase imbalance of low-voltage substation area quickly and accurately, and adjust the load phase sequence in real time without power failure through the intelligent commutation switch system, so that three-phase load in the station area lies a comparatively balanced condition. The scheme can cut down the loss of transformer and line caused through unbalanced three-phase load e in nicely. And it can restrain single-phase overcurrent, and solve the problem of terminal low voltage treatment.
A Collaborative Planning Model of Power Source Considering the Uncertainty of The New Energy and The Power Market
Authors: Wang Ai , Wang Zhigang , Li Xuxia , Li Jia
Published: February 2020

This paper studies the model of power system adapted to the new energy generation and power market environment. A collaborative planning model of power source considering the uncertainty of the new energy and the power market is proposed. The construction of coal-fired thermal power generating units, wind power generators and transmission lines are considered. At the same time, in view of the uncertainty of wind power generation and electricity market, considering from two perspectives: the randomness of wind power output and the use of geometric Brownian motion to predict electricity price. Finally, the example application of the IEEE 30-bus system shows that the model can effectively coordinate the construction scheme of power grid and power supply.
Probabilistic prediction of electric power extreme load
Authors: Xue Jianjie , Wang Haiyun , Wang Ling , Zhang Di , Zhai Yan , Zhang Yuxuan
Published: February 2020

For load forecasting, the difficulty lies in how to accurately grasp some key points in the process of load fluctuation, such as the highest load and the lowest load. It is advisable to call the forecast of daily maximum load and daily minimum load as “extreme load forecast”. On one hand, we can use the whole day load curve forecasting technology to directly get the forecasting results of extreme load; on the other hand, we need to study the special method of directly forecasting extreme load. At the same time, the conventional extreme load forecasting results are generally deterministic. Only a precise value is given, which cannot estimate the probability of the load value and determine the possible fluctuation range of the forecasting results, ignoring the probability characteristics of the forecasting results themselves. In fact, because of the advance of the prediction problem, the realization of the uncertainty prediction is more in line with the objective needs. According to the probability characteristics of the prediction results, it is helpful for the decision-makers to better grasp the objective laws of the research objects in the aspects of risk analysis and reliability evaluation, so as to achieve more reliable and scientific analysis and evaluation. Therefore, it is of great significance to introduce the idea of uncertainty analysis to realize the probability prediction of extreme load.
Relationship between Network Traffic Topology Map and Degree of Competition
Authors: He Hanyue
Published: February 2020

This project will examine the relationship between the degree of competition between access providers and the price of Internet access in a particular country, as well as the impact of access provider topological characteristics on price and quality. Its purpose is to understand whether greater competition will result in lower network access prices. This project uses a scatter plot to show the relationship between these variables and attempts to build a model to express this relationship. The data used in this project includes Internet access prices and topology information of Internet Service Providers (ISPs). The data set is from the author’s previously published article ‘Establishing a database of competition between ISPs based on Python language’. The purpose of this paper is to demonstrate the relationship between the price and the bandwidth of the Internet access and the competition among access provider by the method of data analysis. And at the end, we increase the accuracy of the model by adding the possible influence variables.