Abstract:The lightning strikeback model is an important part of the research field of lightning electromagnetic field. In order to study the lightning electromagnetic field in a deeper level, it focuses on the engineering model in the lightning strikeback model, and combines the most widely used MTLE model in the field of electromagnetic compatibility to select the Heidler function as The current waveform at the bottom of the lightning strikeback channel is simulated by MATLAB, the parameters in the model are changed, the simulation waveform is observed, and the characteristics of the MTLE model and the influence factors of the lightning strikeback channel current are summarized, which is helpful for further exploration of lightning protection.

Abstract:In view of the low accuracy of the traditional transmission turbidity detector in the low turbidity range, a transmission measurement method of variable optical path is proposed, and the interference factors to the transmission light measurement are eliminated. Based on this method, a new type of variable optical transmission turbidimeter is designed. The principle of the instrument and the structure of the sensor are introduced. The design of the optical path structure of the turbidity sensor reduces the volume and cost of the turbidity sensor. The system takes STM32 single chip microcomputer as the core, performs circuit control and signal processing, and has strong anti-interference ability. According to the ISO7027 standard, the turbidity standard solution is configured and the related experiments are carried out to verify the reliability and stability of the self-made instrument. The measurement precision of the transmission turbidimeter is improved in the range of low turbidity measurement.

Abstract:Static Volume method is generally introduced into flow meters, the method is based on steady flow and has some limitations such as uncertainty of measurement results. To study the uncertainty of variable waterhead reservoir in the process of vortex generation and evolution of free surface, large eddy simulation and volume of fluid are introduced into simulating the process of the presence of vortex in a variable waterhead reservoir using the numerical software platform Ansys Workbench FLUENT. According to the flow characteristics, four typical stages of the developing process were selected, and the regularities of the radial velocity, tangential velocity and axial velocity of B-type and D-type free surface vortex along the direction of radial were mainly analyzed. The numerical simulation results show that the vortexs gather towards the center causing the free surface to depress and eventually become vortex and when the water level drops to about 21.4% of the height of the variable waterhead reservoir, the free surface begins to appear depressed.

Abstract:Since the rise of the concept of "neuro-cinematography", the cross-study of cognitive neurology and cinematography has brought more possibilities to the breakthrough of the two fields.As one of the important cognitive neuroscience research methods, electroencephalo-graph (EEG) has been closely associated with the film sleuthing.Based on the introduction of the principle of EEG, this paper compares the application of functional magnetic resonance imaging (FMRI) technology, and explores the cross-development of cinematography and cognitive neuroscience.Finally, in order to explore VR visual language rules by leaps and bounds, break through the traditional research methods of film and television art based on creation, trial and error, summary and evaluation, and put forward the specific research scheme of virtual reality (VR) visual art by using the cross-study path of EEG neuro-cinematography.

Abstract:Aiming at the problems of poor applicability, vulnerability to environmental interference and low measurement accuracy of existing underground pipeline detection methods, a high-precision pipeline measurement robot integration scheme based on pipeline measurement trolley and multi-sensor data fusion is proposed. The system uses the pipeline measurement trolley as the platform, the FPGA is the control core, the inertial measurement unit and the mileage measurement unit are mounted. The attitude information of the pipeline trolley is measured in real time, and the mileage and the position of the underground pipeline are calculated by integrating the mileage data and the starting and ending position coordinates. The test results show that the system has good applicability and strong anti-interference ability, real-time measurement of three-dimensional track parameters of underground pipelines, and synchronous transmission and storage of measurement data; data solution reaches 95 m lateral repeatability ±40 mm, the repeatability of the elevation is better than the ±20 mm high-precision curve measurement index.

Abstract:IC equipment is in the upstream of the IC industry chain, which is an important part of the whole industry. It is of strategic significance for the industrial chain to establish an advanced, safe and reliable equipment industry system in China. IC equipment is an industry with very high technology threshold, resulting in the entire industry by the United States, Japan and the Netherlands a small number of giants highly monopolized. Starting from the analysis of the overall situation of manufacturers, technology status and R&D investment gap, this paper finds that there are some problems in China's integrated circuit equipment industry, such as strong dependence on sales progress of domestic equipment, ineffective integration of domestic equipment with large-scale wafer production lines, and heavy dependence on imports of sealing and testing equipment. Combined with the actual development of the industry, this paper analyzes the current situation and challenges, and makes suggestions on the development of China's integrated circuit equipment industry in this context.

Abstract:For resolving the problem that the maturity performance evaluation system for metering suppliers is not constructed in power company, performance evaluation management system is proposed and designed. The paper analyzes the management mode of the metering suppliers at present. The performance evaluation index system in tree structure based on the key index analysis and mechanism of weighting correction are used to establish performance evaluation model of metering suppliers. The hierarchical management model is designed. Many functions of the system are achieved, for instance, task management, after-sales service management, performance evaluation management and intelligent decision management. The operation result shows that the system standardizes the supplier relationship management of the company and provides an effective technical evaluation means for metering suppliers performance evaluation.

Abstract:Silicon carbide power devices have developed rapidly in recent years, and they have the advantages of high breakdown voltage and high thermal conductivity. The performance of silicon carbide diodes as freewheeling diodes in pulse forming networks is studied by simulation and experiment, and compared with silicon diodes. The experimental results show that silicon carbide diodes are less resistant to surge currents than silicon diodes at room temperature. Both of them have weakened surge current capability at high temperatures, but the ability of silicon ultrafast recovery diodes to withstand surge currents is much lower.It can be predicted that at higher temperature, the silicon carbide junction barrier Schottky diode's surge current capability will exceed that of silicon fast recovery diodes.

Abstract:As it was difficult in the radiation effect induced by the high energy particle incident semiconductor materials, the ground radiation test was studied from the experimental platform.Based on the analysis of the single-event effect, the evaluating method is presented. Mainly consisted of data acquisition system and data analysis system,he experimental platform investigated the effects of four SRAM FPGA chips on single particles under different radiation sources and different intensities.Through the radiation test, the validity and reliability of the test method and test system are verified, and the processing method of test data is mastered.The experimental results show that the high strength, under the irradiation of single particle flip effect significantly increased, need to take protective measures in a timely manner, the use of FPGA chip and selection has reference value.

Abstract:A study on the measurement of chemical oxygen demand (COD) by UV spectrophotometry method, discusses the research method which combining the design of optical system and electronic technology. The system consists of three parts: optical, circuit, and software. Optical system applies plane diffraction grating and optical slit, which improves the stability of optical signal. Electrical system takes high precision and low quiescent current amplifier OPA2335, improves the conversion accuracy and responding speed of weak light signal. Software system uses chloride and COD standard curve to exclude interference which chloride produces during measuring COD. It is possible to measure COD in high chloride water. Measuring COD standard solution and COD standard solution with chloride ion and measuring actual water sample comparing with HACHDR6000 besides stability experiment which can prove the system can be used to measure COD in high chloride water.

Abstract:The design and principle of a complex modulation and wideband agile signal generator is introduced. Through high capacity FPGA control high speed direct digital frequency synthesizer chip,To generate wideband agile IF signal,Digital FM，PM，AM is also available.Previously produced wideband digital modulation signals, It needs to use wideband quadrature modulator.Because of group delay frequency response and temperature drift of wideband analog quadrature modulator,It’s extremely difficult for precise control of two IF signal phase orthogonality.Emphasis is placed on two direct digital frequency synthesizers,and synchronous processing and real time phase difference control,To produce two agile IF signal with phase orthogonality,They are respective modulated with two quadrature digital baseband signal component,To achieve digital modulation of wideband agile IF signal.On the basis of agile IF signal,Use of the wideband microwave synthesis of local oscillator and direct conversion technology achieve coverage of the whole frequency range.Experiments show that agility bandwidth of the signal generator is 300 MHz,Frequency switching time less than 1 μs,Frequency range is 250 kHz～3 000 MHz,EVM less than 2％ and less affected by temperature,It achieves the various analog modulation,digital modulation,complex pulse modulation,intrapulse modulation and fast frequency hopping, it reduces the complexity,the volume and the cost of the system.

Abstract:To address the urgent need for TPS portability of airborne electronic equipment test systems and the current problem of non-specific UUT information description, refer to the ATML standard, UUT model description method based on airborne equipment was studied and modeling software was developed to implement standardized description of UUT. The UUT model description structure of the airborne equipment under test was presented, including the basic information and test information of the UUT, and the signal requirements of the UUT were described using a unified signal and test definition standard STD. When the tested device or test requirements change, a new UUT model xml file can be generated by the modeling software for use by the test program, which avoids the redevelopment of the test program and helps realize the portability of the TPS.

Abstract:The precision and uniformity are important parameters for evaluating metrological radial grating. A set of automatic detection system is designed for the detection of uniformity and precision of the reflective metrological radial grating. This system adds the reflective reading system on the basis of the original angle tester. The signal is transmitted to the computer by the acquisition system, and the location information is passed to the computer by a tiny encoder. Then the data were processed by the LabVIEW, to complete the automatic error detection and process control. Finally, the test results will be printed out and keep on a file. After the actual test on reflective metrological radial grating with 32768 lines. The relative precision error of the grating is ±0.75″, the uniformity error is less than 4.2%. The system was fast, high precision and stability. It simplifies the traditional test equipment and debugging steps, and realizes the automation of measuring the precision and uniformity of the circular grating.

Abstract:An intelligent remote water meter based on MSP430 is designed to solve the problem of anti attack interference of smart card water meter which is widely used at present. The system consists of user water meter and water management center server. MSP430F169 microcontroller is used as the main chip. The main chip peripheral expands the serial communication, liquid crystal display and network communication. After collecting and processing the water flow signal, the information of water consumption is displayed by LCD, the serial port communication and GSM short message module are communicated, when the balance is insufficient, the water meter sends alarm short message and shuts off the water valve. The information exchange between user water meter and water management center is established through Internet. The management center can centrally manage user water meter through network, recharge value, inquire balance and so on, which provides convenience for user, and is the development direction of water meter in the future. It has high application value.

Abstract:Person re-identification is to match the same person’s images captured at different space and different time across non-overlapping camera views. Person re-identification has important application value in video surveillance and is an important basis for intelligent surveillance systems. However, due to factors such as low camera performance, monitoring scene changes and pedestrian mobility, at this stage person re-identification has many challenges such as low image resolution, illumination,background, viewpoint and pose changes. This paper analyzes that the direct removal of the background brings new gradient information at the boundary, which makes the performance of the person re-identification model worse. In this regard, it proposes a simple Gaussian weighting based background suppression method, which can effectively suppress the background and improve the performance of person recognition model.

Abstract:Three frame difference motion detection algorithm can easily cause the foreground objects image contour fracture and blank holes because the logical “AND” operations are used between the results of two frame to frame difference with intersections to extract moving objects. In order to improve the algorithm performance, a double three frame difference method is presented, which uses logical “OR” operations between the results of two or more three frame difference with intersections to extract moving objects contour. This kind of union of set operation can reserve the integrality of the extracted contour to a great extent. The concrete logical construction of the new algorithm is constructed on the base of the successive four and five frames images in a video. The simulation results show that the double three frame difference method is effective in improving three frame difference performances.

Abstract:Artificial intelligence technology has been widely used in many areas. One of the applicationsinthe education industry is automated scoring system for subjective questions.The text similarity calculation is a major difficulty in subjective question scoring. The word similarity calculation based onCiLin has achieved good results, but the long text will lead to the performance degradation of the traditional word similarity calculation method. In this paper, the extended named entity recognition method is used to extract some keywords from the candidate answers of the subjective questions. the improved CiLinword semantic similarity calculation method is used to calculate the similarity between the candidate keywords and the target keywords. The proposed method can effectively improve the word matching efficiency. On the basis of the original CiLinword semantic similarity algorithm, the performance is improved and the calculation time is effectively shortened.

Abstract:With the application of image processing technology in the hydrophobic detection of composite insulators, the traditional manual detection method has been gradually replaced. In this paper, the characteristics of the waterdrop image are used to transform the original image into the HSV color model for preprocessing. The advantage of the contrast between the water droplet and the dry region in the S component is used to the missing part of the interior and edge of the waterdrop image. Filling is performed, and then two different labeled watershed transformations are performed on the preprocessed image. The experimental results show that the algorithm can effectively segment the water bead image, and the shape of the detected water bead is correct. The area error is within 5%, which provides a basis for determining the hydrophobic performance of the composite insulator.

Abstract:In order to develop a substation protection room patrol robot equipment suitable for power grid users, a digital identification method based on support vector machine (SVM) for digital display instrument of substation protection room is proposed, which is used to automatically identify and monitor the digital instrument data captured by the robot. Firstly, a custom threshold segmentation is performed on the image taken by the robot, and the minimum circumscribed rectangle of the connected domain is searched for the digital display instrument region in the image. Then the gray scale, median filtering, image enhancement, digital segmentation, adaptive binarizationand normalization operations are sequentially performed on the acquired digital display instrument region, implementing preprocessing of the digital instrument area to obtain a single number. Finally, a single digital image block processed by the decimal point is input into the constructed multivariate SVM classifier to implement the identification of a single number. The experimental results show that the proposed method can achieve 96.5% correct recognition rate and can be used for intelligent inspection of small patrol robots in substation protection room.

Abstract:In high efficiency video coding HEVC, the latest λdomain rate control scheme adaptively allocates the number of bits for each pixel. In the process of adaptively allocating the number of bits, the encoding quality of the target object is not considered.Aiming at this problem, a video multi target rate allocation scheme based on deep learning is proposed. In this scheme, a target detection algorithm single shot multibox detector (SSD) is first used to detect and identify multi objects in a coded video to obtain object information. Then in the frame level code rate allocation process, according to the difference between frames, an adaptive bit rate is used to allocate a reasonable number of bits for each frame of video. Finally, the quantization quality of the target object is improved with a smaller quantization parameter (QP). The experimental results show that compared with HM16.9, the proposed algorithm improves the global average quality by 0.15 dB and the quality of the target area by 0.35 dB when the code control accuracy is almost constant.

Abstract:At present, industrial equipment often needs microprocessor such as digital signal processor (DSP) to enhance automation capability. However, because of the problems of equipment space and update efficiency, the emulator could not be used to maintain and update programs. In order to solve the above problems, a dual core system based on SCI serial communication is designed to realize DSP online programming in this paper. In this system, the DSP chip is connected with the host computer and the auxiliary chip STM32 through the SCI serial port respectively. The DSP receives instructions and user program data through the SCI serial port and completes the online updating of the program. The experimental results show that this method couldeffectively improve the maintainability of the equipment. At the same time, because there is no need to repeatedly insert the JTAG port on the PCB one by one, the efficiency of updating the equipment software could be greatly improved.

Abstract:Point at the technical requirements of authentication management for man-machine interface (MMI) application on smart phone of feeder terminal unit (FTU), the authentication server should be built in the distribution network control center to realize the security protection for the MMI application onsmart phone.In order to realize the purpose of login authentication for MMI application by asynchronous double factor security system in the control center service software, the dynamic password authentication technology was used with the challenging/responsing mode, and the authentication information was transmitted by the smart phone short message, and tiny encryption algorithm (TEA) was used to encrypt and decrypt the content of short message.On the basis of analysis and study of relevant theories and methods and implementation techniques, the authenticationsoftware was implemented which has been deployed in the user control center room. At last, the purpose of project development has been achieved.

Abstract:Forthe rapid detection of heavy mental ion concentration in water, a protable detection instrument was designed based on electrochemical analysis.The STM32 micrcocontroller was adopted as control kernel, combined with peripheral circuits such as the scanning voltage generating circuit, the potentiostat circuit and micro current detecting unit. And the last two, regarded as core hardware circuits of the system, were analyzed in detail and tested.The results showed that the hardware circuits operated well and the equipment was stable and reliable. Screen-printed electrodes modified by bismuth-film coupled with differentialpulseanodicstrippingvoltammetry (DPASV) provideddeterminate experiment of the concentration of cadmium ion and lead ion in solution, and the stripping voltammetry curves are acquired. Experimental results showed that stropping peak current and heavy mental ion concentration had satisfactory linearity and repeatability, and the linear correlation coefficient of cadmium ion and lead ion reached to 0.9945 and 0.9978 respectively. Compared with atomic absorption spectroscopy (AAS), the maximum relative error is 4.93%,it showed that the instrument was accurate.

Abstract:Aiming at the problems that the existing warehouse environment monitoring system has a low communication efficiency and can notaccess Ethernet, the new system is capable of real-time monitoring of environmental parameters and remote control device. The system is mainly composed of a controller and a plurality of monitors. The controller and the monitor both use STM32 chips based on the ARM core. The monitors are loaded with various sensors to collect environmental parameters. The controller obtains the data of the monitor and responds to the abnormal situation, alarms and automatically opens the safety equipment in the warehouse, so that the environmental parameters of the warehouse are restored to normal. The controller is connected to the W5500 chip through the SPI interface. The W5500 driver combined with FreeModbus protocol stack in the software to realize the Modbus TCP protocol communication function between the controller and the host computer. After testing, the intelligent warehouse environment monitoring system can monitor the environmental parameters of the warehouse in real time.And it can communicate with the host computer via Ethernet to complete the functions of storing, viewing the data and controlling the device to meet the expected requirements.

Abstract:The non-destructive testing of cultural relics has great significance for the protection of cultural relics and can provide a strong basis for subsequent reinforcement and protection. In view of the shortcomings of the traditional ultrasonic testing equipment with small gain and low echo signal characteristics, it is difficult to meet the defect detection of stone or wooden relics. An ultrasonic nondestructive testing system for stone or wood materials based on FPGA as the main controller is designed, and the characteristics of echo signal are analyzed in detail. The hardware part of the system includes the excitation of ultrasonic signal, the amplification of the echo signal, the design of the filter and sampling module. The software part includes the logic design of FPGA and the software design of the USB communication. At the same time, the acquired echo signal is analyzed, including the time domain analysis, frequency domain analysis and wavelet analysis, and the characteristics of the echo signal are obtained, which lays the foundation for the ultrasonic nondestructive testing of the stone wood materials.

Abstract:Data acquisition system is a measurement tool for people to achieve various functions. The high sampling rate, high throughput and high real-time performance become the inevitable trend. Therefore, the key technologies of improvement are successfully carried out and discussed on the basis of the 2.4 Gsps data acquisition system based on high speed ADC EV8AQ160. And finally, using XILINX K7 series FPGA as processing core, a high sampling rate and high bandwidth DAQ system with DDR3 SDRAM's large capacity cache and PXIe1.0 X4 DMA transmission is implemented. The experimental results show that the highest sampling rate of the upgraded DAQ system is increased to 5 Gsps, the effective upload bandwidth is as high as 455 MB/s.

Abstract:The state of the projectile during flight can be used as one of the effective methods to evaluate its operational performance. In allusion to the data acquisition requirements of projectiles in the air, a missile-based multi-channel data acquisition and storage system was designed, in which the system hardware framework is approved. The demonstrated system uses Zynq-7000 series Soc chipas the logic control. The programmable A/D conversion chip AD7606 and large-capacity Nand-flash memory are used to collect and store data. At the software design level, A/D conversion, DMA transmission and data storage are combined to ensure efficient data collection, transmission and storage. Finally, in the turntable and flight experiments, the designed system collects geomagnetic data from the HMC1052 geomagnetic sensor to verify the reliability and correctness of the system operation.

Abstract:DOA estimation is a very important research area in the field of array signal processing. In this paper, the classical MUSIC and ESPRIT algorithms in DOA estimation are briefly described. The spatial spectrum estimation of MUSIC algorithm is performed under Gaussian white noise with zero mean noise and variance of 0.5, and the directions of the three incoming wave signals are accurately estimated. At the same time, by calculating the SNR of MUSIC algorithm and ESPRIT algorithm under different signal-to-noise ratios, the error of MUSIC algorithm is smaller than the error of ESPRIT algorithm, but the running speed is slower. Under the same signal to noise ratio, the number of array elements was changed and the effect of the square error of the two algorithms was observed. Finally, it is analyzed that the external radiation source radar system often uses two or more radar deployment stations in practical applications. Therefore, the dynamic deployment of multi-ship fleets can be considered as a comprehensive problem of deployment forms and platform maneuvers. The detection accuracy of the multi-station external radiation system based on the GDOP representation under the DOA system is analyzed, and the problem of dynamic deployment of multi-station DOA based on sea-based stations is solved.