Abstract：The radar scattering cross(RCS) which represents the echo strength of the target under the incidence wave is one of the most important concepts in the radar stealth. With the characteristics of small(low RCS), slow(low flight speed) and low(low flight height), the RCS of the unmanned aerial vehicle(UAV) in complex electromagnetic environments are affected by the geography, meteorology, non-cooperative radar radiation source and so on. Based upon such conditions, the RCS of the UAV in the complex electromagnetic environments and the influence of the radar echo are presented in this paper. Meanwhile, the research progress on the RCS of the UAV in the complex electromagnetic environments are introduced.

Abstract：In order to solve the difficulty of high density interconnection of multi-chip modules, a kind of microwave interconnection structure based on composite multi-layer printed circuit board(PCB) technology is designed.The optimized multi-layer interconnected structure is only 0.1 dB larger than the insertion loss of ideal microstrip in the 10 GHz～20 GHz, and the VSWR is 0.3. In the 30 GHz～40 GHz range, it is only 0.3 dB larger than the insertion loss of the ideal microstrip, and the VSWR is 0.4, which has good microwave characteristics. This structure has the advantages of simple design and low cost, which can solve the problem of high density interconnection of components.

Abstract：As one of the core components of the RF power system, the RF power source has a fixed frequency and low conversion efficiency, which has become a bottleneck restricting the development of the RF power system. Aiming at this problem, a design scheme for freely switching the RF power source between dual frequency operation modes is proposed. Direct Digital Synthesizer is used as the RF signal source. The MOSFTE producted by IXYS Company of Germany is used to achieve the amplification of small signals, which improves conversion efficiency and the stability of the output frequency. The method of parallel inductors reduces power loss during switching time. Switching the frequency selection network with a digital-controlled switch achieves adaptation of the system at dual frequencies. At the same time, Multisim simulation is carried out on the proposed scheme and theory. After actual testing, the RF power source can achieve dual frequency selection output of 13.56 MHz and 27.12 MHz at 300 W, and the conversion efficiency can reach 90.1%.

Abstract：A miniaturized ultra-wideband receiving front-end applyingto radio reconnaissance is designed in this paper,which converts RF signal of 0.1 GHz to 18 GHz to intermediate frequency(IF) by preselected filtering, amplifying, mixing, bandwidth filtering and gain controlling. The design scheme of the circuit is introduced first, and the key indicators are analyzed and designed. The front-end is 119 mm×61 mm×9.5 mm in size, with operating frequency of 0.1 GHz~18 GHz and typical gain of 35 dB，which can also be adjusted from 30 dB to 40 dB according to project requirements.

Abstract：Microstrip line and coaxial are the two common transmission lines in microwave systems. The common interconnection method between the two transmission lines at the low frequency band is direct soldering. The coaxial inner conductor is soldered on the metal strip line of the microstrip line. The outer conductor is mounted on the ground plane of the microstrip line. This connection has little effect on the transmission of microwave signals in the low frequency band. In the millimeter wave band, this connection will result in an increase loss of the millimeter-wave signal. Therefore, a millimeter-wave band microstrip coaxial transition structure is designed. This transition structure adds a transition hole structure between the microstrip line and the coaxial, which can effectively reduce the voltage standing wave ratio and insertion loss of the microstrip-to-coaxial transition structure, and improve the performance of the overall system.

Abstract：With the rapid development of automotive electronics and advanced assisted driving technology, autonomous driving as an advanced stage of assisted driving technology has become an important way to solve traffic travel in the future, and has become a new hot spot and focus of technology research worldwide. Especially in recent years, autonomous driving has made a milestone in the history of human transportation. This paper briefly describes the development of autonomous driving and the related content of key technologies. On this basis, it reviews the research level of environmental awareness through automatic driving and the use of cutting-edge artificial intelligence technology in automatic driving, involving relevant statements on key technologies such as environmental intelligent sensing，sensors integration, advanced planning, and control. And finally it summarizes the current problems of the automatic driving system, and looks forward to the future development direction of autonomous driving technology.

Abstract：With the development of automatic driving, virtual reality technology and other fields, image semantics segmentation method has also attracted more and more attention of computer vision and machine learning researchers. Firstly, the common terms and background concepts in the field of image semantics segmentation are introduced. Several classical deep learning algorithms in the field of image semantics segmentation, such as full convolutional neural network(FCN), Deeplab and so on, are introduced. Finally, aiming at the current application of image semantics segmentation algorithm, the future research directions are summarized and prospected.

Abstract：Aiming at the performance degradation of objective methods for image quality assessment in practical application scenarios, a visual saliency and complementary features method based on pooling of structure and energy by integrating human visual characteristics into many parts of image feature processing is proposed. Firstly, the three complementary features of image gray energy, contrast energy and gradient structure are processed based on spatial-frequency joint transformation, according to the human eye characteristics. Secondly, multichannel information of the above three layers of visual feature is extracted and assessed, respectively. Finally, the visual feature assessment of each layer is adaptively pooled from the inner layer to the outer layer based on visual characteristics and image distortion. The experiments show that the proposed method holds higher level, better stability, and assessment performance is improved in practical application scenarios.

Abstract：For a long time, all kinds of traffic accidents have seriously affected people′s life，property safety and social and economic development. Traffic accident analysis is the investigation and study of traffic accident data. It finds out the pattern of accident trends and various influencing factors on the overall accidents and researches the relationship between them, so as to quantitatively understand the nature and internal law of accident phenomena. Based on the analysis of the text data recorded in traffic accidents, this paper proposes a text topic extraction model and technology to find drivers′ risk factors in traffic accidents,in order to solve the problem that traffic violations are difficult to excavate in the past, and to calculate the most dominant factors that affecting traffic accidents. Finally, taking the traffic accidents in Beijing as an example, combining with the experience of traffic management experts, the effectiveness of the proposed model is verified. It turns out that the model is valid, and the conclusion with using it is consistent with the long-term management experience.

Abstract：Time series prediction is an important part of abnormal detection of key performance indicators in data centers. For the time series, the wavelet basis function is used as the implicit layer node transfer function to construct the wavelet neural network for prediction. At the same time, the momentum gradient descent method is adopted to improve the learning efficiency of the neural network. Then the optimal solution is trained according to the particle swarm algorithm as the initial neural network parameters. The value is finally simulated using MATLAB, and the time series of key performance indicators are predicted with higher accuracy.

Abstract：In order to solve problems of low integrated and high power consumption in high-order filter, a novel nth-order low pass filter employing multiple-output current differencing cascaded transconductance amplifier(MO-CDCTA) was proposed. The designed circuit does not contain any resistors. With only one multiple-output current differencing cascaded transconductance amplifier and some grounded capacitors, this circuit could achieve current transfer functions of low pass. In CADENCE software, the circuit chip was only 0.04 mm2，the largest power consumption was only 4.18 mW, and the maximum 3 dB cutoff frequency was up 500 MHz. Moreover, third-order Butterworth filter simulation and transient response experiment results validated the theoretical analysis.

Abstract：Aiming at the unique properties of NAND flash, an average update frequency based NAND flash garbage collection algorithm is proposed. Firstly, the victim block selection strategy based on invalid page age sum is adopted. Then, based on FaGC and GCbAH algorithm, the proposed algorithm re-defines the heat degree calculation method, and applies average update frequency of logical page to replace fixed threshold as the criterion of cold or hot data. Thus, more accurate determination and separation of cold and hot data are realized. The experimental simulation results show that compared with GR, CB, CAT, FaGC and GCbAH algorithms, the proposed algorithm has achieved a better performance in terms of garbage collection overhead and wear leveling.

Abstract：With the rapid development of communication and chip technology, IoT will be an important part of the next generation of information technology, a powerful driving force to promote the intelligent process of our lives. Among the IoT terminal applications, ultra-low-power microcontroller plays an indispensable role. Based on the design goal of ultra-low-power embedded applications, this paper proposes a pipeline structure of a processor based on RISC-V instruction set architecture. Taking into account the compromise between power consumption and performance, the main body uses a two-stage pipeline, and was supplemented by a pipeline structure with variable length of other components. The logic function of the microcontroller is verified in the VCS environment. At the same time, the area ratio report of the microcontroller is obtained by using the SMIC180 process library to complete the simulation in the DC environment. Finally, by running the running subroutine test and comparing it with the ARM Cortex-M microcontroller, the comparison results show that this work can also be applied to the low-power scene of IoT.

Abstract：This paper analyzes the necessity of verifying the signal integrity of SRAM-based FPGAs, and a method based on simulation for verifying the signal integrity is proposed. Two series of SRAM-based FPGAs, which are Stratix-2 and Virtex-4 respectively, are verified for the signal integrity based on the IBIS model and the HyperLynx software. The results of simulation verification on the valid-data width, voltage amplitude and transmission rate are analyzed. As a result of verifying both FPGAs, the method based on the simulation is feasible for verifying the signal integrity of FPGAs. And also the model parameters are simulated and compared to obtain the difference between the intrinsic mechanism of signal integrity which guides the optimization of device signal integrity.

Abstract：In this paper, a miniaturized distributed parameter balun filter based on Marchand balun structure is designed. The balun filter is based on low temperature cofired ceramic(LTCC) technology, the balun filter has maked full use of its multi-layer advantages and reduced the volume of the filter by LTCC multi-layer wiring. The structure of the balun filter adopted the spiral wide-side coupled stripline structure(SBCS), and the unique spiral cross-stacking structure, which effectively reduced the volume of the balun filter. The designed balun filter used dielectric material with relative dielectric constant of 9.8. Its size was only 2.0 mm×1.25 mm×0.95 mm. In the range of 1.805 GHz~2.17 GHz,the return loss was less than -12 dB, the amplitude imbalance was less than ±1.2 dB, and the phase imbalance was less than ±10°. It can completely meet the needs of today′s miniaturization of communication equipment.

Abstract：In order to meet the strict requirements of precision, real-time and synchronization of data acquisition in the process of precision equipment monitoring, a multi-channel, real-time and high-speed data acquisition system based on FPGA is designed. This system uses the Spartan6 series FPGA of Xilinx as the core control device, which realizes functions such as data acquisition control, data buffering, data processing, data storage, data transmission and synchronous clock control. The test shows that the scheme has the advantages of high precision, fast speed, good reliability, strong real-time performance and low cost.

Abstract：Using AIS for radar calibration has been widely used in the military field. However, during the calibration process, it was found that the accuracy of the post-school radar was not significantly improved. This paper analyzes the causes of radar accuracy from the error sequence processing level, and proposes a high-precision error calibration method based on AIS. The new method first proposed adding the error distribution analysis to the traditional calibration process, and screening the associated and aligned error sequence for two outliers. The measured data proves that the proposed method can obtain more accurate system error estimates, and effectively calibrates the radar system error, which improves the radar detection accuracy.

Abstract：The frequency detection of current and voltage plays a very important role in the grid-connected control strategy. Large detection errors can cause failure of control algorithms such as phase lock, harmonic compensation and reactive power compensation. Based on this, taking the harmonic separation as an example, the variation of amplitude attenuation with frequency detection error is derived under the condition of multi-channel, second-order generalized integrator(SOGI), parallel operation. The effects of frequency detection error on the separation of harmonics are introduced in detail. To reduce the frequency error, a medium and low frequency high precision current signal frequency detecting device is designed, which is divided into two parts: hardware circuit and software design. The hardware includes controller peripheral circuit, sampling circuit, sensor circuit, voltage follower circuit, voltage bias circuit and so on. The software part mainly includes sampling program, frequency detection program and error correction program. Finally, the simulation results verified the correctness of the theoretical analysis of the frequency detection error. The experimental results of current frequency detection verified the feasibility of the design and the high precision of the device.

Abstract：The application of ultra high frequency radio frequency identification(UHF RFID) in soil sample management can greatly improve the management information level. However, both soil and the attachment mode of label antenna have an influence on the performance of UHF RFID tag antenna. In this paper, the electromagnetic simulation software Ansoft HFSS was used to simulate and analyze the performance of UHF RFID tag antennas, and the influence of tag attachment mode and soil content in sample bottles on the performance of tag antennas was explored by combining the antenna theory. The results show that the direction chart of the label antenna changes greatly when the label antenna is placed vertically. The relative position of soil and label affects the input impedance of the label antenna, changes the recognition distance of the label antenna, and causes the misalignment of the label antenna.

Abstract：An improved timing and frequency synchronization algorithm based on Zadoff-Chu(ZC) sequence for OFDM system is proposed. The algorithm constructs a training sequence with conjugate repetition relationship. Firstly, the timing synchronization is completed by utilizing the conjugate characteristics of the training sequence in time domain, and the integer frequency offset(IFO) estimation is obtained directly, not affected by the frequency synchronization performance. Then the fractional frequency offset(FFO) estimation is done using the repeatability of the training sequence after timing synchronization. Theoretical analysis and simulation results show that the improved algorithm′s timing and frequency offset estimation mean square error is lower, the integer and fractional frequency offset estimation range is expanded, and computational complexity is reduced.

Abstract：In order to lower the sampling frequency of binary offset carrier(BOC) signal, a BOC signal demodulation scheme based on compressive signal processing is proposed. This method can reduce A/D sampling rate and system power consumption, and the hardware structure is simpler than in other systems.The numerical results show that compressed sensing can be successfully applied in BOC signal receiver. Affected by noise folding, BOC receiver of compressed signal processing has a slightly lower performance than traditional receiver, and its advantage is to reduce the complexity of implementation. Considering the quantization of the signal, noise folding has a much smaller effect on the performance of the receiver.

Abstract：The computer technology related to unmanned vehicle driving is developing rapidly, and the vehicle identification technology is more and more widely used in intelligent traffic monitoring and intelligent traffic information systems. Vehicle identification includes sports vehicle detection, type classification, vehicle tracking and so on. In this paper, the key technologies such as vehicle identification detection in smart car unmanned technology are deeply explored. Using the image recognition result of the vehicle, this paper chooses the CAM offset algorithm based on the average color difference value as the basis for identification. The algorithm uses the vehicle color as the feature to perform the tracking detection method, and does not follow the light and dark of the vehicle. The shape change is disturbed, and the reliability in the vehicle identification process is high. This algorithm is improved to achieve better recognition of the vehicle.

Abstract：In order to realize the control of home appliances by gesture and real-time monitoring including alarming of indoor hazards,a smart home system based on somatosensory interaction is designed. The system captures RGBD image information by Kinect device, takes the recognized gesture information as control signal, and controls the household equipment through ZigBee LAN. At the same time, it detects the falls of the elderly or children in the scene in real time, and alarms the dangerous situation. The experimental results show that the system can meet the need of controlling the household equipment by gesture, and can detect and alarm the falling situation.

Abstract：Based on adaptive octree and improved differential evolution algorithm, an implicit surface reconstruction method for three-dimensional point cloud data is presented.Firstly, the original point cloud is adaptively segmented by octree. Secondly, the local implicit surface function is established by using the improved radial basis model of metaball, and the radial basis center, influence radius and shape parameters are adaptively solved by using differential evolution algorithm.Lastly, the improved logarithmic exponential weighted stitching algorithm is used to smooth the local surface, and the moving cube algorithm is used to draw the complete implicit surface.Experiments show that this method not only has good adaptability to many kinds of point clouds, but also can reconstruct the surface with smooth and obvious details.

Abstract：Accurate identification of ECG signals is the key to intelligent diagnosis of ECG monitoring systems. In order to improve the classification accuracy of ECG signals, an improved ECG signal classification algorithm based on BP neural network was studied. Firstly, statistical analysis was performed on the MIT-BIH Arrhythmia Database sample experts. The normal heart beat, ventricular premature beat, left bundle branch block heart beat and right bundle branch block heart beat were selected as neural network recognition targets, and extracted by principal component analysis. 25 heart beat features are used as sample vectors. The simulation results show that the improved BP neural network has better classification and recognition ability, and the accuracy of the whole sample classification is 98.4%. The algorithm has fast convergence speed and high classification accuracy, which is helpful for detecting and diagnosing heart diseases.

Abstract：A miniaturization research of rocket upper stage electric load management center(EMLC) based on SIP concept is presented in this paper, in the background of electron-integrated system on rocket, focusing on the method of design and implementation of a SIP control system in EMLC. The architecture design of SIP control system is completed with the mixed analog-digital FPGA as hardware platform. A design and implementation method of IPs like main protocol engine core, warm backup fiber optic Ethernet core and other main function core has been elaborated. An assistance health management(AHM) system′s design and implementation method in this paper has been simply illustrated. The simulation result of EMLC and experiment result of the SIP control system are also been given.

Abstract：The developing firmware library called STM32-Mat/Target and STM32CubeMX are introduced into MATLAB/Simulink, and a modeling process based on rapid control prototype(RCP) technology is presented firstly to build the prototype system which has the same I/O ports and practical function with standardized products. Then, the modeling method of tested prototype system and configuration of semi-physical simulation are expounded combined with a kind of avionics system, air data computer(ADC), and a technique is presented to develop embedded engineering quickly. Finally, the established prototype system is used for semi-physical simulation to test its performance and effect relative to theoretical mathematical models. The engineering application verification shows that the method above can fully utilize the advantages of the rapid prototype system for semi-physical simulation, combined with the introduction of the development firmware library, it greatly saves time and cost and improves development efficiency.

Abstract：In order to ensure the reliability of long-distance control and data transmission in data acquisition applications, and meet the requirements of multi-channel signal interface switching and parallel data acquisition, a multi-channel acquisition and switching system based on FPGA and TCP/IP is designed. The system uses Xilinx Spartan-6 series FPGA as the main control chip, which can meet the switching of 8 groups of 13 channels, and the synchronous acquisition and real-time transmission of 16 analog signals. The system uses the architecture of FPGA+TOE to realize TCP/IP , and is equipped with a monitoring host computer. The experimental results show that the system is capable of long-term stable multi-channel switching , high-speed acquisition and real-time transmission. It is convenient to use and highly reliable, and has certain application value in the field of distributed acquisition.

Abstract：Focused on the low reliable problem of data existing in high-speed and long-distance transmission process, a method based on long transmission of LVDS and a new type of 8B/10B codec is proposed. The method selects and uses LVDS codec which is made in China, in the hardware circuit, the drive circuit and equalization circuit are adopted to compensate loss of signal in remote transmission; and in logic design, the new type of 8B/10B coding is realized to achieve DC balance of data in transmission and stability improvement in data transmission. Through the verification, error-free transmission of LVDS serial data can be realized at the rate of 500 Mb/s and on 240 m of balanced twisted-pair wire in the system.

Abstract：Long of Range(LoRa),as the current popular Internet of Things communication technology, has mature solutions in the field of environmental monitoring.However,when applied to scenarios with high real-time requirements, such as laboratory security monitoring, its corresponding solution can not show better performance. Based on the current mature LoRa solution, this paper introduces MQTT and Websocket technology in the application layer and service layer communication of its architecture, and combines Node.js and Redis technologies in the service layer to design low-latency laboratory security. The application layer of the system includes real-time display of web page data, mobile application data viewing, and abnormal information alarm notification. At the same time, in order to realize the practical application requirements of centralized management of multiple monitoring areas,a data push strategy is designed to improve data transmission efficiency, and reduce the rendering time of the web page. The test results show that compared with the existing environmental monitoring solution, the system can transmit terminal data to the application terminal with lower delay.