bluuebunny/crossref_metadata_2025 huggingface dataset:
A Localization Algorithm of Double Radars Based on Two Moments
Authors: Tang Tao , Pan Jin , Yang Deqiang , Ma Boyuan
Published: November 2018

This paper proposes an algorithm of localization based on FPGA and PC. It calculates the position of the target based on the geometrical relationship between the radars and the target through the speeds of the target and the peak-to-peak values measured by two radars at two moments. Currently, almost all the Doppler radars work with frequency modulated continuous wave(FMCW) and finish the frequency measurement by singlechip machine(SCM). This method only need radars work with continuous wave(CW) and finish the frequency measurement and localization on FPGA and PC. It can achieve the least error localization at the lowest cost. This system can alert the drivers to a vehicle in the blind area and remind the position and the speed of the vehicle relative to their vehicles. It can improve the safety of vehicles when changing lanes and turning, and effectively decrease the incidence of traffic accidents.
Numerical simulation of shallow square boxes with flanges based on Dynaform
Authors: Liu cunping , Liu yong , Guo sheng
Published: November 2018

In this work, Numerical simulations based on finite element method have been carried out to study the effect of important process parameters on formability of AA5182 alloy sheets. The blank holder force between 0.5KN and 3KN and friction coefficient(μ) between 0.05 and 0.20, which resulted in successful drawing, was evaluated. Maximum percentage thinning has always been obtained at the conjunction of corner and bottom. The maximum thinning rate was nearly 20% for a maximum holder force of 3KN. Friction coefficient simulations are shown that as friction coefficient increasing, the thinning rate becomes larger and low friction coefficient is beneficial to the sheet forming.
Fast Algorithm for Passive Interference of UHV Transmission Lines
Authors: Lu Ying , Zhao Zhibin , Zhang Jian gong , Gan Zheyuan
Published: November 2018

Passive interference analysis of transmission lines to radio stations is almost entirely based on the method of moments (MOM) or the rapid multipole method and multi-layer fast multipole method (FMM) developed by the method of moments. Based on the above algorithm, this paper proposes to use a diffraction model (UTD) and an optical diffraction method (PO) to model different transmission lines with different radii. The calculation results show that the difference of field strength generated by transmission lines with different radii varies with the distance of the observation point on the transmission line, and the accuracy of the UTO method is much smaller than that of the PO method. It can make good results that provides technical foundation for future modeling.
Non-local mean filtering algorithm based on deep learning
Authors: Liu Baozhong , Liu Jianbin
Published: November 2018

Aimed at the problem that the traditional image denoising algorithm is not effective in noise reduction, a new image denoising method is proposed. The method combines deep learning and non-local mean filtering algorithms to denoise the noisy image to obtain better noise reduction effect. By comparing with Gaussian filtering algorithm, median filtering algorithm, bilateral filtering algorithm and early non-local mean filtering algorithm, the noise reduction effect of the new algorithm is better than the traditional method and the peak signal to noise ratio is compared with the early non-local mean algorithm. The performance is better.
Design of marine small temperature salinity meter based on ARM
Authors: Liu Wei , Huang Xi , Zou Da-peng
Published: November 2018

This design aims to solve the current problem that the ocean temperature salinity meter in marine research has high accuracy, but the cost is high, and it is not easy to combine with other modules. This design is small temperature salinity meter with STM32F103 as the MCU using the temperature-conductivity integrated sensor and depth sensor. The accuracy mainly depends on the sensor. Users can replace the sensor to convert accuracy and control cost. The single-cell lithium battery is used as the power supply. It can be charged via USB, and can run for more than two hours. Communicated with USB, the upper computer can take the data from the lower computer to draw a curve and display the data at a fixed point on the computer screen, which is convenient for the user to analyze the data. The data is stored as a text file, and the user can place the data in other software such as Matlab for data analysis. This design provides a multifunctional and miniaturized instrument for the demands of the booming development of seafloor in-situ observation systems to conveniently measure salinity,temperature and depth of seawater and sediment.
The application of improved FDTD algorithm based on mode-matching in shielding cavity
Authors: Gao Xuelian , Kong Lingli
Published: November 2018

Due to the increasing complexity of the electromagnetic environment, the cavity with apertures are used more and more widely in electromagnetic shielding. At present, the time domain finite difference (FDTD) method has a good application effect for the transmission line response problem of a double-layer shield cavity with apertures, but this method usually encounters the boundary problem of semi-open and open areas. Due to the limited computing resources, the truncation of the FDTD region has an impact on the accuracy and speed of the calculation because that is very important. Based on that, this paper puts forward a method of combining mode-matching method with FDTD algorithm, which overcomes the limitation that mode-matching method can only be used for regular waveguide analysis and uses mode-matching method to solve FDTD boundary problems. The improved FDTD algorithm based on mode-matching method enhances the accuracy of the algorithm and guarantees the calculation speed.
Method and practice of comparing indicators from standards
Authors: Gong Kenan , Gan Keqin , Li Aixian
Published: November 2018

Chinese standards and foreign standards differ in technical indicators and requirements, which result in the poor recognition of products that comply with Chinese standards. It is crucial to set up a universal method to compare standard indicators, so that the inconsistency between standards could be eliminated, and ultimately improve Chinese products competitiveness. This paper proposed a method for indicator comparison from standards. Based on Semantic Web technology, the method introduced fragmentation of standard documents in a manner of ‘product stylistic rule indicator’ triplet. The processed fragments were annotated by the knowledge-based organization and used for the following indicator comparison. The method and procedure were generalized to develop standard indicator comparison system. The system provided a great experience in representing technical indicators as well as the comparison of indicators from standards. Further practice of the system suggested that repeated standard development and conflicted indicators in Chinese standards are still common.
Application of Variable Weight Coefficient Method in State Evaluation of AC Contactor
Authors: Su Yuze , Liu Zichun , Gao Kai , Na Guangyu , Liu Shuxin
Published: November 2018

AC contactor state evaluation is a challenging problem. This paper proposes an AC contactor state assessment method based on variable weight coefficient. Firstly, the characteristic indicators that have a great influence on the state of the AC contactor are selected, and the state evaluation index system is established. Secondly, using the subjective and objective combination weighting method combined with the analytic hierarchy process and the grey relational analysis method, the constant weight coefficient is obtained, and the variable weight coefficient method with the equalization function is introduced to obtain the variable weight coefficient of each characteristic parameter. Finally, the fuzzy comprehensive evaluation method is used to evaluate the running state of the AC contactor. The experimental results show that the state evaluation method proposed in this paper can accurately reflect the real state of the AC contactor operation and effectively improve the reliability of the power system.
Design and Implementation of Online Management System forStudents' Fourth Class Credits
Authors: Chen ZhenMing , Bao Zhengde , Li Chenxi
Published: November 2018

Since the concept of the Fourth Class (Comprehensive quality ability teaching) has been presented, the results of the Fourth Class have been enormous. How to manage information informatization is an urgent problem to be solved. This paper uses the mature management system technology to informatize the Fourth Class management.
An Adaptive Reconfiguration Mechanism for Periodic Software Rejuvenation based on Transient Reliability Analysis
Authors: He Pan , Liu Gang , Yuan Yue
Published: November 2018

While software rejuvenation is used to prevent severe software failures, existing researches generally choose the constant-value periodic policy through steady-state reliability optimization. Since the software reliability declines with the execution time, a steady policy either introduces extra overhead or could not guarantee the reliability constraints. So an adaptive mechanism is proposed to reconfigure the software rejuvenation in the runtime. The transient reliability analysis is used to choose an optimal rejuvenation policy which maintains the software reliability for a certain period of time. A dynamic time series is generated for the reconfiguration process and the optimal rejuvenation policy is re-calculated according to the reconfiguration intervals during the software execution. Experimental studies results show that as the execution time increases, the software reliability drops continuously and the optimal rejuvenation interval should be decreased to maintain the same reliability constraints. This mechanism guarantees the software reliability constraint by resetting the optimal rejuvenation policy dynamically according to a reconfiguration interval time series.
Research on Improved Canny Edge Detection Algorithm
Authors: Liu Ruiyuan , Mao Jian
Published: November 2018

Aiming at the poor noise robustness of traditional Canny algorithm and the defect of false edge or edge loss, an edge detection algorithm using statistical algorithm for filtering denoising and using genetic algorithm to determine the optimal high and low threshold of image segmentation is proposed. Firstly, statistical filtering uses mean and variance to denoise, avoiding the problem of Gaussian denoising susceptible to interference in the traditional Canny algorithm, and ensuring the integrity of image edge information. Secondly, this article uses the genetic algorithm, design the crossover operator and genetic operator to modify the evolution of the population, and determine the optimal height threshold of the image edge connection to make the threshold more accurate. Finally, using MATLAB software to simulate, the results show that the improved Canny edge detection algorithm can further improve the anti-noise ability and robustness, and the edge location is more accurate.
Intelligent Routing Control for MANET Based on Reinforcement Learning
Authors: Dong Fang , Li Ou , Tong Min
Published: November 2018

With the rapid development and wide use of MANET, the quality of service for various businesses is much higher than before. Aiming at the adaptive routing control with multiple parameters for universal scenes, we propose an intelligent routing control algorithm for MANET based on reinforcement learning, which can constantly optimize the node selection strategy through the interaction with the environment and converge to the optimal transmission paths gradually. There is no need to update the network state frequently, which can save the cost of routing maintenance while improving the transmission performance. Simulation results show that, compared with other algorithms, the proposed approach can choose appropriate paths under constraint conditions, and can obtain better optimization objective.
Design and implementation of sewage cloud platform monitoring system
Authors: Wang Wencheng , Yao Jinfeng , Qiu Shengpeng
Published: November 2018

With Guohua Sewage Treatment Plant being the centre of management and control, by means of structural analysis and construction of cloud platform, important running data, equipment state and surveillance video of each sewage treatment site built or being built nearby will be stored and categorized. Then analysis and decisions will be made, ensuring the good functioning of sites monitored by managers of the centre control site. At the same time, mobile applications can be used on smart phones with the support of the system, thus making it possible for managers to conveniently visit surveillance data in real time through web pages or app. With this arrangement in place, effective management measures will be taken in the shortest time every time the equipment of any one site is out of order. The entire system design has achieved many functions directed at multiple sewage treatment sites, such as decentralized control, centralized management, remote diagnosis and fault early warning.
Design of a Hybrid Railway Power Conditioner with Co-phase Power Supply System
Authors: Xu Pengfei , Zhang Qiao , Yao Jie , Chang Yantao
Published: November 2018

With the widespread use and rapid development of electric locomotives, the negative sequence and excessive phase problems of traction networks have become increasingly prominent. A hybrid railway power conditioner system (H-RPC) for co-phase was proposed, And compared with the traditional RPC system. The paper analyzed its topology and compensation principle. The design of its key parameters was given. The analysis results show that H-RPC has better compensation effect than RPC. Finally, the correctness of the H-RPC compensation effect is verified by simulation.
VI Curve Test Based On Discrete Excitation Signals
Authors: Cao Yong , Tang Xinchi , Shao Sijie
Published: November 2018

In-Circuit Test System is an instrument that uses the VI curve test to diagnose circuit faults. Generally, continuous signals such as sine wave, triangle wave and square wave are used as the VI curve test excitation source. There are some problems in the synchronization of the analysis. In this paper, we study a VI curve test based on discrete excitation signal, analyze the problems arising from continuous signal testing, and propose a continuous signal discretization circuit scheme. The feasibility and practicability of this method are proved by Matlab simulation and experiment.
Study on Stability Analysis of Steel Cylinder Retaining Structure
Authors: Li Bin
Published: November 2018

The steel cylinder structure is generally used as a wharf revetment structure. It is necessary to evaluate the safety and stability of the steel cylinder structure as the retaining structure for offshore foundation excavation. In this paper, a large finite element software PLAXIS is used to simulate the safety factor and the structural displacement of the steel cylinder structure in the wave load and the excavation of the foundation. The calculation results show that the overall stability of the steel cylinder is 1.7 when the most unfavorable condition of excavating from the foundation to the bottom of the steel cylinder. The lateral displacement is 572mm, which meets the safety requirements of the structure. The steel cylinder structure can play a role as the water retaining structure of the cofferdam and the support structure of foundation when it was put into the non-permeable layer.
Fault features analysis for soft faults of analog circuits with tolerance
Authors: Zhang Chaojie , He Guo , Yu Jiankeng , Pan Xionglong
Published: November 2018

Soft faults of analog circuits are more difficult to diagnose than hard faults because the soft faults are caused by the deviations of component parameters. Node voltages were traditionally used as the testing signals to diagnose analog circuits. With the rapid development of integrated circuits technology, fewer and fewer circuit nodes are accessible. Only the output voltage can be tested in many cases. This cries for other new accessible signal except for the traditional voltage signal. In this paper, the fault features of testing signal in both time-domain and frequency-domain are analysed. The output voltage was acquired firstly. Its fault features were extracted and used for fault diagnosis. The results show that the soft faults of Tow-Thomas filter cannot be uniquely located by using this output voltage only. Then a new accessible signal, which named dynamic power supply current, was acquired and its fault features were analysed. And the results were compared with those using output voltages. The comparing results show the validity of dynamic power supply current. This signal contains information related with the circuits’ topology and can be used for fault diagnosis of analog circuits.
Research on Electromagnetic Side-channel Signal Extraction for Mobile Device PCM-9589F Multi-COM
Authors: Hu Xiao-yang , Chen Kai-yan , Zhang Yang , Guo Dong-xin , Wei Yan-hai
Published: November 2018

The portability and various functions of mobile devices enable them to go deep into people's study, work and life. While it is convenient for people, mobile devices contain a large number of user’s private information, such as the user's personal property information, identity information and even the confidential information of enterprise etc. Side-channel attack is currently one of the most effective ways to steal private information of cryptographic devices thus the threat to mobile devices can be imagined. In this paper, the electromagnetic side-channel attack based on AES encryption algorithm on mobile device—PCM-9589F Multi-COM Board is studied. A new signal acquisition platform is designed, which solves the problem that the difficulty in locating the side-channel electromagnetic leakage signal of the mobile devices. In addition,using the time-frequency analysis and filter technology,we extract the encryption features of AES on PCM-9589F Multi-COM Board.
The Design Of Intelligent Filter For EEG
Authors: Yue Dachao , Liu Haikuan
Published: November 2018

EEG data processing method is usually digital filter designed by the traditional method. Its disadvantage is the transition zone is wide and the filtering effect is poor. Using an improved particle swarm optimization algorithm on IIR digital filters design, the performances of filters designed by various methods are compared and analyzed. Experiments illustrate particle swarm optimization algorithm is effective in IIR filter design and its performance is promising.
Construction and Application of Indoor Video Surveillance System Based on Human Activity Recognition
Authors: Wang Yuchen , Wang Mantao , Tan Zhouyu , Zhang Jie , Li Zhiyong , Mu Jiong , Zhou Zhihao , Luo Lixing
Published: November 2018

With the growth of building monitoring network, increasing human resource and funds have been invested into building monitoring system. Computer vision technology has been widely used in image recognition recently, and this technology has also been gradually applied to action recognition. There are still many disadvantages of traditional monitoring system. In this paper, a human activity recognition system which based on the convolution neural network is proposed. Using the 3D convolution neural network and the transfer learning technology, the human activity recognition engine is constructed. The Spring MVC framework is used to build the server end, and the system page is designed in HBuilder. The system not only enhances efficiency and functionality of building monitoring system, but also improves the level of building safety.
SIMULINK Simulation Implementation of DS/FH Hybrid Spread Spectrum Communication System
Authors: Ma Bing , He Ye , Ma Hualong , Yu Changren
Published: November 2018

The basic principle of DS/FH hybrid spread spectrum communication system is introduced. The Simulink simulation software is used to establish the system simulation model, and the dynamic simulation of the system is realized. The anti-jamming performance of the system under tracking interference and blocking interference is analyzed.
Research on Induction Motor Vector Control System Based on Internal Model Decoupling
Authors: He Hu-cheng , Wang Wen-ting , Zhu Qun , Shi Lei
Published: November 2018

As a high-performance variable frequency control technology, vector control has been widely used in the field of AC speed regulation. However, the cross-coupling potential of the induction motor after the vector transformation still affects the system performance. Therefore, the method is studied in which stator current is decoupled to excitation component and torque component using internal model control, and the internal model decoupling stator current controller is designed based on rotor field orientation. The simulation model of induction motor vector control system based on internal model decoupling is constructed with Matlab/Simulink. The simulation result shows that the internal model controller is superior to the traditional PI controller in disturbance-rejection performance and robustness.
Single Phase Sine Wave PWM Inverter Circuit Simulation And The Design Of Filter Based On Matlab
Authors: Yanshu Niu
Published: November 2018

Inverter circuit is the most important application of PWM control technology. This paper mainly discusses the unipolar PWM ( pulse width modulation ) control mode of single-phase bridge inverter circuit, and uses MATLAB visual simulation tool Simulink to model the circuit. At the same time, a filter is designed to filter the waveform of the inverted output so that the output waveform can reach a smooth sine wave shape. This simulation not only deepens the understanding of PWM inverter circuit theory, but also lay a good experimental foundation for the study of modern power electronics.
Research on CGF Formation Maintenance and Obstacle Avoidance
Authors: Wang Siqing , Qiao Yongjun
Published: November 2018

In order to solve the problem of CGF formation avoiding obstacles, avoiding collisions and reach the target point in the simulated battlefield environment, combined with the behaviour-based method, the following algorithm will be improved to control the CGF formation. In this paper, the motion of CGF formation is decomposed into moving to target, maintaining formation, avoiding obstacles, restoring formation, reaching target, and a linear feedback mechanism based on the relative position of leader and follower is introduced to prevent the occurrence of the team. The tangent obstacle avoidance algorithm evades obstacles. The simulation experiment applies the upper-layer behavioural reasoning to guide the structure of the underlying physical model, and the SOAR agent makes the choice of the state of the environment and the behaviour, and the underlying physical model implements the behaviour. The results show that the strategy can keep the CGF formation in the desired formation, avoid internal collisions while avoiding obstacles, and quickly restore the formation after reaching obstacles, reach the target location and achieve good results.
Research on Temperature Control Technology of Thermal Vacuum Test in Aerospace Field
Authors: Ning Juan , Shao Jing-yi , Zhou Ying , Liu Yang-yang
Published: November 2018

The temperature control system is an indispensable key system for the thermal vacuum test. It is used to simulate the infrared heat flow environment of the spacecraft in orbit. In order to improve the stability and reliability of temperature control, this paper designs and develops a thermal vacuum test temperature control system based on the Modbus RTU serial communication protocol on the LabVIEW platform. The system combines the flexibility of software development on LabVIEW platform and combines the stability of serial communication with controller. This temperature control system has been used in thermal vacuum test, the control effect of overshooting within 1°C and temperature control accuracy within ±0.2°C. The system has high stability, which achieves the expected goal.
Solution for the Drift Problem of the Chip in the Packaging Process
Authors: Dong Shaohua , Liu Yueyang , Jin Rui , Leng Guoqing , He Feng , Liu Jiang , Pan Yan , Wu Junmin
Published: November 2018

This paper analyzes the drift phenomenon of the chips appearing in the packaging process of the fast recovery diode (FRD), and proposes an effective process to solve this problem. In order to improve the trade-off characteristics of fast recovery diodes, lifetime control methods, such as electron irradiation, high-energy ion implantation and so on, are often introduced in the chip manufacturing process. The chips described in this paper use the lifetime control method of electron irradiation. The problem of chips drift during the packaging process has been found. In this paper, by comparing different back metal schemes, comparing and analyzing the products of different manufacturers, the cause of chips drift is ultimately located in the annealing process after electron irradiation. The result of this paper shows that the chips drift phenomenon can be solved by adjusting the process steps.
The overall design and full-aircraft aerodynamic simulation of the tilting rotor cargo UAV based on variable shaft angle gear drive
Authors: Chang Chia-kan , Huang Jingjing , Zhang Cong , Gao Yue , Wang Ya-ni , Shuang E , Chen Xubing
Published: November 2018

Traditional tilt rotor aircraft rely on turning the whole engine nacelle, to accomplish the transformation between vertical take-off and landing as well as flying. This scheme has a large rotational inertia and requires a heavy and complex tilting mechanism. the engine jet flow in the process of vertical take-off and landing directly spray down, and this flow could blow up the sand and stone, let engine suck it in or hurt people. So this paper designed a new rotated way based on variable shaft Angle gear transmission. The carrier aircraft design scheme referenced the data come from following software and website. The data of airfoils come from the software profili and the website Airfoil Investigation Database. The pressure distribution as well as air flow simulation and calculation is based on XFLR5. The mechanical, appearance and overall design is based on CATIA. The gear contour design is based on CAXA CAD and the full-aircraft aerodynamic simulation is based on ANSYS/FLUENT. The engine with this design is fixed, so it only needs rotate the tilting rotor shaft, and the mechanical structure is relatively simple, which make this aircraft can play an important role in the future logistics and transportation system.
Analysis of Doppler frequency shift response mechanism based on OFDM system
Authors: Li Ke , Sun Zhiguo , Ning Xiaoyan , Diao Ming
Published: November 2018

OFDM system is widely used in mobile communication because of its high spectral efficiency and strong anti-multipath capability. However, in high dynamic scenarios, the Doppler shift between the transmitter and the receiver destroys the orthogonality between the sub-carriers, resulting the interference between the sub-carriers and distortion of the signal, which greatly degrades the system performance. In this paper, a mathematical model of Offset-OFDM system was established and the Doppler response formula of OFDM system in high white channel was derived. Furthermore, we investigated the factors that influence the performance of OFDM. This study laid the foundation for determining OFDM system parameters in high dynamic scenarios.
Modified Variable Step Size FLOM-CMA Based on Lorentzian Function under Impulse Noise
Authors: Liao Xichang , Lei Yingke
Published: November 2018

Aiming at the problem that the traditional equalization algorithm under impulse noise is difficult to suppress impulse noise and achieve equalization, a new modified variable step size FLOM-CMA algorithm based on Lorentzian function is proposed in this paper. The proposed algorithm has modified the cost function to made full use of the phase information of signal to correct the phase rotation. Also, by adjusting the FLOM of cost function, that impulse noise is restrained effectively. Furthermore, the Lorentzian function is use to update the step size to make sure it is is appropriate for each equalization point. Simulation experiments show that, compared with FLOM-CMA and VS-FLOM-CMA, the proposed algorithm that the proposed algorithm achieves higher convergence accuracy with similar convergence speed. And under different impulse noise conditions, the robustness of the algorithm is better.
Software defined network intrusion detection in wireless sensor network
Authors: Yan Nan , Zhang Ping
Published: November 2018

Software Defined Network (SDN) realizes the separation of control functions from data planes and network programming. It lays the foundation for centralized and refined control and has greater advantages over traditional networks. At present, the research on SDN mainly focuses on wired network and data center, while software definition is proposed in some studies, but only in the stages of models and concepts. According to the characteristics of wireless sensor networks, this paper takes anomaly intrusion detection as the main research content. The sensor network is defined based on OpenFlow software combined with SDN, and intrusion detection technology is studies on the basis of this. It is easier for the system to control the network and its resources in SDN architecture. The Network traffic shows self-similarity in large time scale. In this paper, it can distinguish between the normal situation and the attack by observing the change of the self-similarity coefficient of the network, so as to realize the intrusion detection.
Analysis of Signal Reception Mechanism of Sky Wave Long-distance Maritime Communication
Authors: Ren Huantao , Xie Qiangjun , Chai Jiajing , Xue Yi
Published: November 2018

Based on the principle of high frequency radio propagation, the signal reception mechanism of sky wave communication over oceans is investigated. Due to long distance signal transmission, the energy loss is inevitable, especially in the space and on the sea surface. Firstly, we establish the space propagation loss model by the ionospheric absorption, the free space propagation characteristics and other extra loss. Referring to the reflection principle of smooth ground and the Kirchhoff approximation, the energy loss models of the calm sea surface and the turbulent sea surface are obtained respectively. Then, through combining the space propagation loss model and the sea surface propagation loss models, we give out a formula of receiving point field strength. According to the signal to noise ratio, we summarize a complete and concise sky wave maritime communication calculation process, through which multi hops number of the receivable sky wave signal can be calculated accurately. The experimental results show the effectiveness.
Spectrum estimation of electromagnetic signal based on AR model parametric spectrum estimation
Authors: Zhou Ju , Lei Lihua , Liu Naijin
Published: November 2018

For the low accuracy of classical spectrum estimation, the AR model method in modern parameter estimation is proposed to analyze the spectrum of electromagnetic signal. The basic principle of AR model is introduced and the Burg algorithm is simulated by Matlab. The electromagnetic signal in the real environment is simulated by the classical FFT method and the AR model method. Comparing the results show that the AR model is more accurate and reliable in the detection of electromagnetic signals, so modern parameter spectral estimation can be used as a method for spectrum analysis of electromagnetic signals.
Design of low-power 2FSK demodulation circuit
Authors: Liu Guo Feng , Liu Xi , Tian Xing Guo
Published: November 2018

Aiming at the complex structure and high power consumption of the existing 2FSK demodulation circuit, this paper designs a simple structure and low power 2FSK demodulation circuit. A CMOS transistor matrix circuit is used to demodulate the 2FSK signals of 1200HZ and 2200HZ. The function model is established by using Matlab, and the number of sampling points is determined according to the simulation results and design requirements, and then the size of CMOS transistor matrix circuit is determined. The circuit uses Cadence software for functional verification, and HSPICE software is used for power consumption analysis. The simulation results meet the design requirements of low power consumption and achieve the desired demodulation effect.
Study on static characteristics of pneumatic muscles
Authors: Wang Hu , Yan Hongwei , Wang Haodong , Yang Zhong , Ni Zhiguang , Li Zhe
Published: November 2018

In this paper, the static characteristics of pneumatic muscles are studied by means of theoretical modelling, numerical simulation and experimental verification. Firstly, on the basis of ideal mathematical model, the static mathematical model of pneumatic muscle considering elasticity and friction of rubber is given. Based on the established mathematical model, a pneumatic muscle simulation model is established by using SIMULINK toolbox in MATLAB software environment, which includes model parameter assignment module, pneumatic muscle ideal module, elastic force simulation module, friction simulation module and so on. The influence of elastic force and frictional force of rubber layer on the output force of pneumatic muscle during pneumatic filling is studied by numerical simulation. Finally, a mechanical gripper test rig driven by pneumatic muscle is built. The experimental results show that pneumatic muscle actuator has certain flexible grasping characteristics. The research results provide a reference for the wide application of pneumatic muscle.
The Design of Multirotor Aircraft-based Environmental Detection System
Authors: Fan Maoyan , Zhang Lifang
Published: November 2018

This research aims at an environmental parameter detection system based on the small quadrotor UAV. The system comprises a quadrotor UAV platform, an environmental parameter detection system, a data acquisition system and a data processing system. The temperature and humidity, as well as the concentrations of particulate matters, carbon monoxide, carbon dioxide and sulfur dioxide are detected by various types of sensors, and the data are read, written and stored by Micro SD card module. Through validation, it is found that the system has the advantages of low cost, easy operation, flexibility and convenience and can expand other types of sensors to meet different environmental information measurement requirements and reflect the environmental information in a real-time manner.
Wireless Charging Technology Based on Photovoltaic Power Generation and Its Application
Authors: Fan Maoyan , Zhang Lifang
Published: November 2018

A new technology of wireless charging based on the photovoltaic power generation micro-grid is designed with the combination of photovoltaic array and battery to ensure the reliability of power supply. This research aims at the transmission principle of the series-parallel (SP) wireless charging technology via coupled magnetic resonances and the relationships of power, frequency, distance and efficiency. The charging strategy integrating maximum power point tracking with four-stage charging is achieved. The Boost circuit with XC164CM single chip microcontroller as the core is designed and fabricated for the charging experiments. The results show that this method can charge quickly, avoid overcharge and realize optimum system running, thus having broad application prospects and high promotion value.
Research on Power Stability Control of Semiconductor Laser
Authors: Guo Qian , Zhang Xiaodong , Tian Fengnian
Published: November 2018

In order to guarantee the stable emission power and good working environment of semiconductor laser, a new hardware circuit is selected and designed to realize automatic optical power control, in which a negative feedback operation amplifier circuit is adopted to form the constant current source, and an optoelectronic feedback to realize closed loop control in this paper. And then, the corresponding steady control circuit is also designed, so that the stable power can be output. The experimental results show that the stability of laser power is better than 0.74% when the system works.
La prématurité spontanée et le microbiote maternel
Authors: Côté Nathalie , Pasquier Jean-Charles
Published: November 2018

Des millions d’enfants naissent prématurément chaque année et les cliniciens restent démunis face à la difficulté de maîtriser la physiopathologie associée, ce qui limite les options thérapeutiques. Récemment, il a été suggéré que le microbiote maternel pouvait contribuer au bon déroulement de la grossesse et qu’une dysbiose pourrait entraîner une naissance avant terme. Certaines espèces commensales de Lactobacillus participeraient à une fonction de « filtre vaginal », empêchant une propagation ascendante de pathogènes vers la cavité utérine. Ce compartiment peut par ailleurs être colonisé par des bactéries buccales, suggérant la possibilité de leur dissémination par voie hématogène vers l’utérus.
Retour sur les origines de la vie
Authors: Danchin Antoine
Published: November 2018

Regarder plus de trois milliards d’années en arrière est difficile et la reconstruction d’arbres de l’évolution à partir de l’ADN actuel repose sur des hypothèses cachées qui ne permettent pas de retrouver ses vraies racines. Cherchant à s’affranchir de notre anthropocentrisme, le scénario proposé dans les deux textes qui seront successivement publiés écarte pour commencer l’idée d’une origine unique pour le remplacer par un scénario d’évolution qui ferait apparaître un processus réplicatif – formation d’une copie exacte – au sein d’un système chimique qui ne fait que se reproduire, formant des copies voisines de ce qu’il est. Les premières cellules formeraient une population de prédateurs assimilant peu à peu divers compartiments où se déroule la suite des étapes ancestrales. Échappant aux cellules prédatrices, deux types nouveaux, peu compartimentés, bactéries et archées seraient alors apparus pour envahir la Terre, former des organites au sein des prédateurs ancestraux en donnant la vie telle qu’on la connaît aujourd’hui.
P2X4, Ca2+ et CXCL5, un nouveau trio pro-inflammatoire
Authors: Angora Ginette , Prost Marion , Dellis Oliver
Published: November 2018

Pour la troisième année, dans le cadre du module d’enseignement « Physiopathologie de la signalisation » proposé par l’université Paris-sud, les étudiants du Master « Biologie Santé » de l’université Paris-Saclay se sont confrontés à l’écriture scientifique. Ils ont sélectionné 8 articles scientifiques récents dans le domaine de la signalisation cellulaire présentant des résultats originaux, via des approches expérimentales variées, sur des thèmes allant des relations hôte-pathogène aux innovations thérapeutiques, en passant par la signalisation hépatique et le métabolisme. Après un travail préparatoire réalisé avec l’équipe pédagogique, les étudiants, organisés en binômes, ont ensuite rédigé, guidés par des chercheurs, une Nouvelle soulignant les résultats majeurs et l’originalité de l’article étudié. Ils ont beaucoup apprécié cette initiation à l’écriture d’articles scientifiques et, comme vous pourrez le lire, se sont investis dans ce travail avec enthousiasme ! Une de ces Nouvelles est publiée dans ce numéro, les autres le seront dans les prochains numéros de m/s.
Comparison of the Effects of Prophylactic and Therapeutic Administrations on Peripheral Neuropathy in Streptozotocin-Diabetic Rats with Gliclazide or Methylcobalamin
Authors: Yao Hongping , Feng Juanyi , Zheng Qiaowei , Wei Youxia , Yang Guangde , Feng Weiyi
Published: November 2018

Objective To observe the differences in curative effects between prophylactic and therapeutic administrations of Gliclazide (GLZ) or Methylcobalamin (MCA) on diabetic peripheral neuropathy in rats.

Methods GLZ (25 mg/kg/day) or MCA (175 μg/kg/day) was orally administrated prophylactically to streptozotocin-induced diabetic rats for 8 weeks before diabetic peripheral neuropathy developed or administrated therapeutically after diabetic peripheral neuropathy developed, respectively. The motor nerve conduction velocities (MNCV), aldose reductase (AR) activities, the polyol contents and antioxidative enzyme activities in the sciatic never tissues were determined. The morphology of sciatic never tissues was observed.

Results In comparison to vehicle, most of the changes in the sciatic nerves of the diabetic rats (e. g., delayed MNCV, altered/damaged nerve structure, enhanced AR activity, increased polyol contents, altered Cu, Zn-superoxide dismutase, glutathione-peroxidase activities, and elevated malondialdehyde level) were significantly ameliorated by prophylactic administration with either GLZ or MCA. In contrast, only few of above-mentioned parameters were alleviated in DPN rats by therapeutic administration with GLZ or MCA as compared to vehicle. The curative effects of GLZ or MCA prophylactic administration on MNCV, AR activity, polyol contents and antioxidative enzyme activities were markedly stronger than therapeutic administration.

Conclusion Prophylactic administration of GLZ or MCA was superior to the therapeutic administration in alleviation of diabetic neuropathy in STZ-rats, suggesting that pharmacotherapy should be initiated at a much earlier stage before diabetic neuropathy developed, but not at a later stage after never damage reached.
Zusammenhang zwischen der Einnahme von Lithium und neuroradiologischen Veränderungen bei der bipolar affektiven Störung: Gibt es Hinweise auf ein klinisches Ansprechen?
Authors: Hamm Carlo , Queissner Robert , Pilz Rene , Birner Armin , Platzer Martina , Fellendorf Frederike , Maget Alexander , Bengesser Susanne , Dalkner Nina , Reininghaus Bernd , Reininghaus Eva
Published: November 2018

Zur Vermeidung affektiver Krankheitsphasen im Rahmen der bipolar affektiven Störung erfolgt die psychopharmakologische Behandlung mittels sogenannter Phasenprophylaktika. Traditionell werden unter diesem Begriff die Wirkstoffe Lithium, Valproat, Lamotrigin und Carbamazepin zusammengefasst. Moderne Therapiekonzepte zur Phasenprophylaxe berücksichtigen ebenfalls Antipsychotika der zweiten Generation. In dieser Literaturrecherche sollen die Zusammenhänge zwischen den biologischen Veränderungen des Gehirns und der Einnahme von Lithium dargestellt werden. Hierbei werden Daten aus makrostruktureller, mikrostruktureller und spektroskopischer Bildgebung angeführt.

Daten zu Veränderungen der Makrostruktur unter Lithiumtherapie sind quantitativ am stärksten untersucht. So scheint Lithium im Zusammenhang mit einer Vergrößerung des Volumens von kortikaler und subkortikaler grauer Substanz zu stehen. Des Weiteren zeigt sich unter Lithiumtherapie eine geringradigere mikrosturkurelle Veränderung in Marklageralrealen was auf einen möglichen neuroprotektiven Effekt von Lithium zurückzuführen sein könnte. An Hand der 7-Lithium-MR-Spektroskopie konnte gezeigt werden, dass remittierte und nicht-remittierte Patientinnen und Patienten signifikante intrazerebrale Konzentrationsunterschiede aufzeigen.

Präklinische Daten weisen auf lithiuminduzierte promitotische, als auch antiapoptotische Mechanismen hin und stützen somit die Hypothese eines volumenerhaltenden Effektes mittels Neurogenese. Jedoch könnten hinsichtlich des Lithiums auch osmotische und physikalische Effekte maßgebliche Ursachen für die Volumenzunahme in der makrostrukturellen Bildgebung bilden.

Das mehrheitliche Vorhandensein von Querschnittsstudien zu dieser Thematik und kleine Kohortengrößen stellen typische Limitationen der untersuchten Studien dar.

Hinsichtlich der Forschung zum Lithiummetabolismus könnte insbesondere die 7-Lithium-Spektroskopie zukünftig eine Methode darstellen, um diesbezügliche pharmakokinetische Unterschiede zwischen remittierten und nicht-remittierten Patienten aufzuklären.
Aerosolcharakteristika ausgewählter Druckluftvernebler für Erwachsene in Simulationsmodellen und Verneblung von Salbutamol
Authors: Walz-Jung H. , Krämer I. , Kamin W.
Published: November 2018

Ziel Der Erfolg einer Inhalationstherapie wird durch Menge und Qualität des inhalierten Aerosols bestimmt. Die Auswahl eines Verneblers bedarf der Kenntnis der entsprechenden Aerosolcharakteristika.

Methoden Die Aerosolperformance von 9 marktüblichen Druckluftverneblern wurde in vitro in 2 Simulationsmodellen geprüft. Salbutamol (Sultanol forte® Fertiginhalat 2,5 mg/2,5 ml; GSK) wurde über 4 Minuten vernebelt. Die Outputparameter wurden mit dem Atemzugsimulator PARI Compas II (Erwachsenenmanöver nach Ph.Eur.9.0; n = 5/6 Verneblungen) und die aerodynamische Partikelgrößenverteilung mit dem Next Generation Impaktor (Ph.Eur.9.0, Copley Scientific; n = 3 Verneblungen) per HPLC bestimmt.

Ergebnisse Die Vernebler generierten deutlich unterschiedliche Abgaberaten und Aerosolspektren. Die Drug Delivery Rate (DDR) variierte zwischen 196 µg/min (PARI LC Sprint (blau)) und 67 µg/min (MIDINEB). Die aus DDR und Feinpartikelanteil ≤ 5 µm berechnete intrapulmonal deponierte Aerosolmenge (Respirable Drug Delivery Rate, RDDR) variierte um den Faktor 3,5.

Schlussfolgerungen Die Ergebnisse der In-vitro-Untersuchungen können unterstützend zur Auswahl eines geeigneten Druckluftverneblers genutzt werden. Für eine effektive Therapie und gute Compliance sollte ein Vernebler mit einer hohen RDDR gewählt werden.
Folsäure-Einnahme bei Berliner Frauen in Abhängigkeit vom sozioökonomischen Status
Authors: Birkenberger Annabelle , Henrich Wolfgang , Chen Frank
Published: November 2018

Einleitung Adäquate Serumfolatspiegel vor und in der Schwangerschaft tragen zur Reduktion des Risikos für einen Neuralrohrdefekt beim ungeborenen Kind bei. Viele Schwangere nehmen Folsäure ein, die wenigsten jedoch wie empfohlen schon präkonzeptionell. Ziel dieser Arbeit war eine Bestandsaufnahme des Einnahmeverhaltens unter schwangeren Frauen und Wöchnerinnen in Berlin.

Methodik Mithilfe eines Fragebogens wurden Schwangere und Wöchnerinnen anonym über eine etwaige Folsäuresubstitution befragt. Es erfolgte eine logistische Regressionsanalyse, um unabhängige Assoziationen zwischen mutmaßlichen Prädiktor-Variablen und der Wahrscheinlichkeit einer Folsäure-Einnahme während der Schwangerschaft zu ermitteln.

Ergebnisse 90,7% (n=1069) der Frauen hatten zu irgendeinem Zeitpunkt in der Schwangerschaft Folsäure eingenommen, 37,8% (n=445) wie empfohlen präkonzeptionell. Frauen substituieren häufiger präkonzeptionell Folsäure, wenn sie ihre Schwangerschaft geplant haben und je besser gebildet, besser verdienend und älter sie sind. Frauen mit nicht-deutscher Staatsbürgerschaft oder Sprachkenntnis nahmen signifikant seltener Folsäure ein als deutsche Frauen. Bildung, Verdienst und vorherige Schwangerschaftsplanung sind unabhängige Prädiktoren für eine präkonzeptionelle Folsäureeinnahme.

Schlussfolgerung Fast zwei Drittel aller schwangeren Frauen nehmen zu dem Zeitpunkt, zu dem sie es am ehesten benötigen, nicht genügend Folsäure zu sich, und zwar v. a. die Frauen, die wenig Geld verdienen, einen niedrigen Bildungsstatus haben, sehr jung sind, ihre Schwangerschaft nicht planten, kein Deutsch sprechen und/oder eine andere Staatsbürgerschaft haben.