Abstract:This letter presents the fabrication method of flexible singlecrystalline germanium nanomembrane （GeNM）pintrinsicn (PIN) diodes on plastic substrate and radio frequency (rf) characterization under off state of various bending strains. In order to quantitatively research the RF characteristic variations with different mechanical stress applied on the flexible PIN diode under reverse mode, accurate equivalent circuit models were set up under different bending radius. After researching the model parameters of the diode varying with the mechanical stress, it can be obtained internal resistance, parasitic inductance, p+p junction resistor and pn+junction capacitance are the main factors affecting the rf characteristics. Mechanical bending makes these parameters change monotonously, which results the rf characteristics of flexible singlecrystal germanium PIN diode getting better under the off state. It also shows great potential in the strain measurement field.

Abstract:This paper reports the realization, radio frequency characterization and modeling of flexible spiral inductors on low cost, flexible plastic substrates. The spiral inductor on plastic substrate exhibits better performance compared to the one on conventional silicon substrates. The peak Q value of the 6.2 nH flexible spiral inductor is 14.2 and the selfresonant frequency is up to 9.2 GHz. An equivalent circuit model of flexible spiral inductors on plastic is presented. And the equivalent circuit model achieves good agreement with the experimental results. The optimization methods of improving the performance of flexible spiral inductors are presented by the simulation of model parameters. The study provides guidelines for properly designing and using spiral inductors in flexible circuits and systems.

Abstract:3D model retrieval is a research focus at home and abroad. In this paper, we propose a novel 3D object retrieval system via group sparse coding based on multimodel dataset. First, we extract SIFT feature from a series of 2D model images which recorded from each 3D model. Then the visual topic distribution generated by LDA(latent dirichlet allocation) is selected to represent each 3D model. Finally, the sparse coding algorithm is utilized to compute the similarity between different 3D models as to solve the retrieval problem. Experimental results demonstrate the effectiveness of the proposed algorithm.

Abstract:Fuse trimming test is widely used in wafer test process of mixed signal circuit chip, however it’s difficult to control test precision and the test efficiency is low because it has many kinds of types, the control circuit is complex and trimming is easily affected by changing in the resistance. Aiming at the problems, a test system control circuit for serial and parallel architecture of trimming is put forward, and a calculation method of reducing test error is displayed. Finally, the traditional test process is improved and a simplified procedure based on the combined test steps and parallel tests is made out. The test result turns out that this method can effectively improve test efficiency and accuracy.

Abstract:Aiming at the nonlinear, strong coupling and timevarying characteristics of permanent magnet synchronous motor and the traditional PID control strategy can't follow the change of system parameters and automatically make the corresponding setting. Through the analysis of fuzzy control, this paper puts forward a simple and practical control strategy of permanent magnet synchronous motor, namely fuzzy PID selftuning SVPWM control. Adopt the method of SVPWM produce three phase current drive motor, the fuzzy control rule was established based on fuzzy logic statements, and combined with PID control parameters, realtime change motor control parameters of the function, and using Matlab tools to establish the fuzzy selftuning PID SVPWM closedloop vector control system simulation model.The simulation results show that the system speed to realize no overshoot, response speed and disturbance recovery time shortened by half compared with the traditional PID control method. The method to improve the control precision of the permanent magnet ac servo system, has a good dynamic and static performance, on the engineering application provides a simple and easy to realize the control method.

Abstract:In order to overcome the shortcoming of complex and traditional methods in measuring standard resistor, and to calibrate the standard resistor fast and accurately, this article has proposed a new method of measuring the standard resistor based on the digital multimeter—8508A’s function of true Ohm ratio method. In this article, both the direct fourwire ratio measuring method and true ohm ratio measuring method were adopted to calibrate the standard resistor, and we find that true Ohm ratio method can eliminate the influence of thermoelectric power and circuit disorders better. Compared with the traditional and complex measuring method, this method is more convenient and efficient. Finally, the measuring uncertainty of calibration values has been also analyzed and assessed in order to verify the accuracy and reliability of this calibration method.

Abstract:Voltage ACDC converter standard is one of the common electricity metering standards, compared with voltage ACDC converter standard, AC voltage can ultimately be traced to DC voltage, which has a higher precision. This article describes several common voltage ACDC converter standard principles and calibration methods. Calibration methods in the millivolt range of ACDC converter standard, procedures and major sources of uncertainty are briefly analyzed and explained, this paper also gives a system design of 10∶1 voltage divider selfcalibration. On this basis, the paper also describes the ACDC converter calibration data processing methods and formulas.

Abstract:In order to realize realtime continuous variable frequency of ACAC converter,further studied the principle of ACAC frequency conversion,approximation of cosine wave crossing and the principle of double variable,then proposed the strategy research on realtime continuous frequency control of ACAC converter based on low current detection.This strategy used low current detection to judge current commutation segment and moment,calculated trigger point at point online based on approximation of cosine wave crossing.To verify the feasibility of this control strategy,set up the ACAC converter speed control system experimental platform based on stm32f103zet,and wrote the program based on the principle of double variable,approximation of cosine wave crossing and the strategy of low current detection.Experimental results showed that the strategy has better control performance.

Abstract:Measurement error for echo intensity of weather radar mainly results from radar hardware and will have a direct influence on the accuracy of quantitative precipitation estimation. This paper introduces calibration principles for operational weather radars of China and USA. In addition, it compares two expression forms for weather radar equation using Syscal and dBZ0 as calibration constant respectively. Moreover, it analyzes factors that affect measurement accuracy of echo intensity, namely, variations in transmitter power and receiver gain. What is more, taking CINRAD radars（Beijing CINRAD/SA and Hangzhou CINRAD/CA） and WSR88D（KTLX and KICT）radars as examples, it presents practical variation curves and analysis results for calibration constants. By comparison, it can be found that calibration process using dBZ0 as calibration constant is more stable and hence is helpful for improving radar data quality.

Abstract:The new type of two wheeled car in the field work and urban road patrol has important application value, the two wheeled vehicle self balancing control to ensure the stability of the car is the key to stable operation. As a result of the two wheel drive control system is a multi input multi output nonlinear strong coupling system, in the unstable road prone to shake. On the basis of conventional synovial control, a nonlinear sliding mode switching surface error tracking is introduced, and a two wheeled self balancing control algorithm is proposed, which is based on the suppression of the interference of the synovial membrane. The motion state equation and equilibrium control parameter analysis model of two wheeled vehicle was constructed. The model of the control law was designed by nonlinear sliding mode control law, and the nonlinear integral compensation was added to compensate the car chattering and improve the robustness of the car balance control system. Simulation results show that the proposed control algorithm has good performance in balancing the two wheeled vehicle, the output of the attitude error is reduced, the stability of the car is better, and the self balancing control and regulation of two wheeled vehicle is realized.

Abstract:when measuring the frequency of the control module's power and the feedback signal, traditional measuring methods susceptible to noise, temperature and circuit parameters. It is difficult to achieve the required accuracy for these methods. In this paper, a discrete Fourier transform and interpolation analysis method will be used, using the fast Fourier transform to analysis signal's spectrum first. Then It discusses the causes of error and method for reducing errors and improving accuracy by interpolation method. Finally, the experiments showed that the measurement results within the accuracy requirements. The method can meet the requirements of using.

Abstract:In the wind tunnel experiments, there are some unfavorable factors when acquire oil film evolution image on surface of the wing to be measured. These unfavorable factors include surface curvature of the wing、surface vibration、the relative position of imaging equipment、changes in the refractive index of light and so on. In order to overcome these unfavorable factors, projection measurement technique for curved surfaces is introduced. According to the imaging principle of pinhole camera model, we establish the mapping model of the pixels in the imaging plane and its corresponding spatial position in this paper because of filming figure brightness is not high, marked points is not easy to extract. Redundancy information fusion methods are used to reduce the mark point extraction error. In the experiment of measuring the wing surface friction using fluorescent oil film method in wind tunnel, surface projection measurement technique has been verified，and the 2D oil film evolution image is projected into the corresponding threedimensional space.

Abstract:In SCSR (sparse coding sparse representation) algorithm, the universal overcompleted dictionary cannot be adapted to variety types of images and too much redundancy is introduced by global sparse reconstruction. To overcome these shortcomings，the SR algorithm based on MCA (morphological component analysis) decomposition and sample clustering is proposed. Firstly, the training feature patchs are clustered by Kmeans algorithm, and then each clustering is trained to get dictionaries, which are used to process variety types of images. Secondly, the image is decomposed into texture component and smooth component by MCA method. The texture component is reconstructed sparsely and the smooth component is enlarged by Bicubic algorithm. Finally, compared with other SR methods, this algorithm can restore the image edge details better.

Abstract:Because of the special environment of the underground railway train,and the different operating condition(maneuvering or nonmaneuvering), with traditional Kalman Filter,it is difficult to react filtering error problem in the mine realtime positioning system. proposes the data processing method with interaction multiple model Kalman (IMMKalman) Filter.the way adopts IMMKalman to filter processing position of underground ailway train estimated by wifi and microinertial unit combination location,The simulation results show that the IMMKalman can effectively reduce the realtime positioning error，so can enhance realtime performance and positioning accuracy.

Abstract:The load of ITER test platform is a superconducting coils which has large inductance, when it connected to the grid will produce large amounts of reactive power, resulting in grid voltage drop, affecting power quality. In order to detect the reactive power compensation effect of reactive power compensation and filtering devices, this paper achieves the calculation of reactive power by Hilbert algorithm and interpolation FFT algorithm of double spectral lines, then using data acquisition card and LabVIEW for realtime test data gathering, analysis and display. It verifies the validity of the two algorithms by comparing the results of power quality analyzer.

Abstract:As the image channel is the main module of the pod, it is the bridge which connects the guided missile and aircraft and the detection of it is important. In order to realize the fast and accurate detection of the image channel, this paper uses the idea of modular design, and designs a convenient and fast method for image detection. The hardware of the system is based on the industrial control computer and the PCI bus technology is used to realize the transmission and collection of the image signal. This paper designs a kind of convenient and fast channel image detection system, proposes an image quality assessment method, which combines the gradient based similarity deviation and brightness. By using the threshold value we can easily judge whether the image channel can be used or not. The computer simulation results show that, this system can achieve the detection of image channels, improve the testing efficiency and meet the test requirements.

Abstract:Image watermarking technology has been developed rapidly, but the research of digital video watermarking is still difficult. In order to protect the copyright of digital video content, a novel video watermarking method using positive and negative quantization was presented in this paper. Some selected video frames were used to embed watermark information. The brightness component of the carrier video frame was divided into several blocks. Each block was implemented discrete cosine transform(DCT). The watermark was embedded in the low frequent DCT coefficients. The watermark embedding and extraction were based on positive and negative quantitative manner. In order to enhance the security of the algorithm, the watermark image and the random binary image were used as the inputs of the cellular neural network (CNN), and the output was used for embedding. The experimental results had shown the robustness of this method to common attacks. This method is simple, and is convenient for realtime video processing.

Abstract:A new remote direct reading gas meter system is designed. In the system, an image acquisition module is equipped on the gas meter. The meter image is collected and sent to a remote server by GPRS. The gas reading is read out on the server through image processing and pattern recognition technology. In the image acquisition module, the block iterative algorithm is adopted for image binarization processing. This makes it have better adaptability and the influence of the environment is reduced. The image data are compressed before remote transmission. In the server, the meter characters are recognized through secondary image processing, digital image segmentation and template matching algorithm.

Abstract:Electrical impedance tomography (EIT) is a medical imaging modality that is used to compute the conductivity distribution through measurements on the crosssection of a body part. As a result the boundary shape of the organisms is different, building different boundary shape will affect the precision and clarity of imaging, so to build a suitable boundary shape is the precondition of solving the forward problem of EIT, especially in the chest. According to the actual visual effect, the elliptical geometry conforms to the chest boundary shape, due to the construction and finite element method of a circular shape is quite mature, this article uses conformal mapping method convert circular to elliptical geometry, and then analyzes and compares the two shapes respectively with the original chest geometry, the results showed that to build elliptical geometry in analyzing the forward problem of chest structure has higher precision, in solving the inverse problem has smaller reconstruction error.

Abstract:Nowadays many watermarking algorithms have been proposed and implemented for multimedia watermarking. Compared to the image watermarking and audio watermarking, the data of video watermarking is larger and the processing is more complex. In this paper, the FFMPEG platform is used which can greatly reducing the complex programming. In order to improve invisibility and robustness of the watermarking, a key frame of the MPEG2 video is extracted and the discrete cosine transform(DCT) is implemented. We use the Itti’s visual saliency model to distinguish visual salient regions and after scrambling binary watermark, then the DCQIM is adopted to embed the watermark on visual nonsalient regions to ensure that the embedding watermark on the video achieve the minimum impact. The results of the experiment show that the algorithm has good invisibility and has good robustness to common attacks.

Abstract:A wheeled negative pressure adsorption climbing robot carrying a high definition camera and a far distance wireless transmitter moves smoothly on the nuclear power plant containment wall. When the robot moves on the containment wall, the camera fixed on the robot sent the wall video information back to the receiver at the bottom of the containment wirelessly, then the receiver transfers the video information to the local PC. The video will be analyzed, processed and displayed by the monitoring and measuring processing software system installed on the PC, and then the image which contains defect information will be transferred to the defect measure module for defect measuring. Finally the defect information and the corresponding image will be stored into the backstage database. This is quite convenient for online and offline browsing to check and monitoring dynamic change of the containment defect.

Abstract:In order to realize the multiposition temperature accurate monitoring, wireless transmission and alarm in time, this paper designs a kind of wireless multiposition temperature monitoring and alarm system based on nRF24L01 and DS18B20. The whole system is divided into the master and the slave, which makes multiposition temperature monitoring come true by the nRF24L01 module multichannel communication controlled by STM32. The whole system hardware design and software program realization method is presented in the design. After online tested, the system is able to acquire multiposition temperature data correctly and reliably. By the low power dissipation and costeffective design ideas, the design solves the problem that the traditional routing is complex and the data transmission is unstable. Meanwhile, it has a good application value in agriculture, industry and other fields.

Abstract:This paper describes a fault detection and diagnosis method with BIST technology to verify the integrity of the embedded multiplier cores in Alteral’s FPGAs. This approach uses an architecture independent test algorithm implemented by the hardware description language. Through three configuration download, it can detect all kinds of faults in multipliers at the modes of operation. At the same time, it can identify the location of faulty multiplies. Finally, verifying the effectiveness and accuracy of the proposed method through an integral BIST test circuit which based on the test model of measured multiplier.

Abstract:In this paper, we treat the parking lot surveillance video as the research object of parking space detection algorithm. Firstly, the algorithm obtained the feature information of the related parking spaces through offline testing in different environment background. Secondly, a single parking area is extracted as the region of interest (ROI). It is used three kinds of parking space detection algorithm to them respectively. The algorithm running on ARM + DSP heterogeneous dualcore processor DM3730 platform and embedded Linux operating system. Both OpenCV image processing function and DSP algorithms for image processing are used that the results can be saved to the embedded database,then more parking space detection based on B/S network model could be realized. Test results show that each user may use the browser to access the system, and get the information about the current parking space occupancy, which can satisfy the requirement of high realtime performance and high accuracy.

Abstract:A photogrammetric control system of parabolic trough collector is designed in this paper. The photogrammetry image acquisition tasks can be automatically completed by this system. According as the front projection of PTC is 6 m×14 m, 8.5 m×17 m rectangular rail is designed to carry the slider. According to the system requirements, friction wheel drive transmission is adopted by slider to complete the movement of camera in the straight line. Servo provides power to the threeaxis electric pantilt unit. The pantilt unit can complete the attitude adjustment of camera in three dimensions. PC control interface include system debug, parameter setting save and automatic operation functions. Finally, various parts of photogrammetry control system is assembled. The design and production of photogrammetry control system for parabolic trough collector is completed. It was showed from experiments that the photogrammetry image acquisition tasks can be automatically completed by photogrammetric control system.

Abstract:According to the precise quantitative requirements of clinical medicine field in CRP concentration of blood detection, a design of highprecision CRP fluorescent detector based on STM32F429IGT6 processor was introduced in this paper. Firstly, the working principle based on fluorescence immunechromatographic technology and the nonlinear regression quantitative model that can achieve accurate quantitative detection were presented. Secondly, the hardware and software design of detector is described in detail. Finally, many test that has been verified by commercial detector have been done to show that the quantitative error is less than 5% and the repetition error is less than 3%, in line with the detection requirements of clinical medicine.

Abstract:In the design of intelligent vehicle collision avoidance system, the intelligent distance measurement is the key technology to avoid the collision of the vehicle and avoid the collision of the vehicle. In the traditional method, the local sensor nodes are used to quantify the tracking method, and the accuracy of the measurement is decreased with the increase of vehicle speed and stop. An intelligent ranging method based on the two time harmonic linear frequency modulated signal detection is proposed. Firstly, the echo detecting and ranging principle is analyzed. And then, the IIR adaptive filter is designed, and the impulse response of the echo signal is realized. The simulation results show that the method has better accuracy and less influence on distance estimation, and can be used in intelligent vehicle collision avoidance system.

Abstract:In the background of the growing demand of fall monitoring system for elderly people, a portable fall monitoring system is developed based on multiinformation fusion of triaxial acceleration sensor, plantar pressure pickup and ultrasonic ranging device. Firstly, MSP430F149 is selected as microcontroller,and the ZigBee is used for the communication between the monitoring system and data center. Secondly, the threshold technology is applied for fall recognition. The new system also had function of automatic alarm and manual lifting of the alarm. The experimental results shows that the recognition rate reaches at 99% for the body movement posture model, include the falling left, falling right, falling forward, falling backward, sitting down, jumping, and walk. The development of the system can provide function support for the IOT (internet of things) of health monitoring for elderly people, especially can help the falling people in time.

Abstract:PM2.5 refers to the particulate matter in a diameter smaller than or equal to 2.5 micron, also known as “fine particulate matter”. It has a lot of effects on human health and environmental quality due to its small volume, rich contents of toxic and harmful substances, long stay in air and long distance of transport. This design uses microcontroller as the controller, combined with the dust sensor GP2Y1010AU0F, A/D converter, wireless transceiver module, clock module and LCD, enables the host to collect and transport the outdoor PM2.5 in realtime, and enables the slave to display the dust concentrations, air quality standard, time, temperature using scale transformation and prompt the outdoor travel on LCD in realtime. Date comparison in the system debugging process shows that the design features simple structure, low cost, visual display and other, which can be somewhat referential for the realtime monitoring of PM2.5.

Abstract:In flight test, pressure is an important test parameter which concerns the flight quality and safety. Due to the characteristics and system errors of the differential pressure sensor, the hysteresis nonlinearity introduced in the process of testing calibration has a great influence on the precision of the sensor. The principle and hysteresis nonlinearity of differential pressure sensor used in flight test was introduced. According to the hysteretic characteristic performed in the process of sensor calibration. The hysteretic inverse operator and TS hysteretic inverse model was constructed, meanwhile the cocalibrated data of the sensor was compensated. It was suggested that the inverse hysteretic model had favorable approximation ability to compensate the hysteresis error of sensor on the simulation result and has great significance to improve the test precision of the differential pressure sensor.

Abstract:The vehicle portable data acquisition platform is built up by DH5902 hardened dynamic data acquisition system and the test data is timedomain analyzed and frequencydomain analyzed applying LabVIEW software aiming at the dynamic test problem of gun firing on the move. First of all, the parameters to be measured of gun firing on the move are analyzed and test project is built up. Then the test data saves in the DH5902 data acquisition device is import into the computer disk, the eliminating trend item program and filtering program are built up by LabVIEW software and the data is preprocessed. Lastly, the data is timedomain analyzed and frequencydomain analyzed, the vibration characteristics of the gun firing on the move is obtained. The analysis results could afford guidance for reliability design and adjustment and afford theory according for further firing on the move dynamic simulation.

Abstract:Servo motors are an important part of the antenna transmission chain in shipbased measurement and control antenna.Because control systems are away from the antenna, it is not easy running realtime monitoring of the servo motor. To solve the problem of realtime monitoring during multiple antenna servo motor running, we studied the data collection and fault diagnosis technology of servo motor, From hardware design, software and database design, network model is proposed based on three aspects of the design troubleshooting servo motor condition monitoring system. So that we can monitor the realtime transmission chain online motor running,and backup servo motor performance measurements can be detected.Practical application shows that this system can timely response servo motor working condition, and to achieve the effect of the remote testing and diagnosis.

Abstract:In order to quickly find out the fault components of the electronic components of the photoelectric radar, and shorten the time of troubleshooting, a fault detection system based on photoelectric radar is designed and realized. System based on VC + + development platform, according to the practical experience of photovoltaic radar electronic components common faults are analyzed. Based on this, a fault tree based on electronic components is established. In the probability of bottom events is given on the basis of the analysis and the probability of top event to occur, to calculate the importance of all parts of the fault tree to the whole system, analysis and comparison of the order of magnitude, to find a larger influence on the system's failure parts.It is verified that the method can quickly find the fault source and the accuracy can be greatly improved by using this method.

Abstract:This paper introduces the necessity of installing insulation monitoring device in high voltage DC(HVDC) system, analysis the shortcomings of the current insulation detection methods, proposed a perfect monitoring method, and emphatically introduces the principle and application of the method. This method can detect the bus voltage and the grounding resistance when bus or branch in the symmetrical grounding or not, so the reliability and the accuracy are improved. The results of multisim simulation and experiments show that the device can detect the insulation resistance accurately, and then find out the fault branch, it is very convenient for fault analysis staff. Finally, some suggestions are put forward for the use of the device.

Abstract:The feature extraction of Hbridge inverter electrolytic capacitor parameters fault diagnosis is researched. The capacitor aging characteristics is analyzed by the traditional fundamental equivalent analysis based on the fundamental harmonic. In the actual situation, this method has large error and its reliability is poor. In order to solve the above problem, this paper puts forward to use the wavelet packet frequency band energy method to extract the fault feature. This method can accurately extract the signal band energy changed information. Through building the simulation model of Hbridge inverter to simulate the different capacitance aging fault, the band energy can be extracted under the capacitor normal and varying degrees of aging based on the wavelet packet frequency band energy method, feature vectors are constructed, and Hbridge inverter electrolytic capacitor characteristic change rules are sought as the capacitor aging. Simulation results show that this method can accurately extract the Hbridge inverter electrolytic capacitor aging fault feature.

Abstract:As the communication carrier of airborne equipment, sub avionics system and avionics modules, data bus play an important role on the modern aircraft performance.Airborne highspeed data bus is the key technology of new generation advanced integrated avionics system, which used for realtime transmission of audio, graphics, images, video and other large volumes of data. A brief overview of several typical airborne highspeed data bus techniques and their development actualities was given in this paper, and then discussed the prospects and value of 1394B and Fibre channel from comparing their transmission speeds, protocols, topology and technology maturation status.

Abstract:Using the embedded software defined radio platform USRP E110, a wireless communication system which uses binary phase shift keying (BPSK) as the modulation method is implemented for portable wireless communication applications. In this system，the ARM processor acts as the processing core, implementing all baseband signal processing; FPGA(field programmable gate array) and radio frequency daughter board act radio frequency frontend, where digital up convert or digital down convert and the transition between the IF signal and the radiofrequency signal are implemented on; and GNU radio acts as the software development platform, implementing the base band signal processing in the form of a flow graph, such as scrambling and perturbation, BPSK modulation and demodulation. The results show that, the system can transmit and receive data using various parameters such as RF frequency, transmitted power and so on, which is portable and low power.

Abstract:Based on the advanced wireless communication technology, in order to accomplish the waveform data and parameters of the multi station medical equipment in the client terminal remote monitoring, the data communication and real time data acquisition system of medical equipment is designed and realized. The system realizes the following functions: data acquisition, data processing, data buffer, data transmission, data query,data review,data display and so on. The system has good manageability and adaptability under the condition of the changes of number of the machine, complex system status,as well as the bad communication environment. The system has high accuracy, high stability, high efficiency and good adaptability.

Abstract:In this paper, we investigate the performance of the twoway decodeandforward (DF) relaying system with automatic repeat request (ARQ) protocol in Rayleigh fading channels. In the proposed ARQ scheme, the ARQ process is carried out by all of the nodes including two source nodes and a relay node which have the buffers to store the signals received from different slots. In order to make full use of the received signals in diffident slots, MMSE signal detection and maximal ratio combining (MRC) are used in the protocol where retransmission are requested according to different conditions and nodes. In addition, simulation results show that the proposed protocol can improve the packet error rate (PER) and spectral efficiency of the DF based twoway relay system than the conventional ones.

Abstract:Using Android platform to design the campus property management system based on the disadvantages of the traditional campus property management system. The system uses the B / S architecture, the technology of QR codes, HTTP protocol and the data exchange technology of JSON to realize the dynamic management of campus property. The results of test and preliminary application show that the system has a portable, practical, userfriendly features, strong practicability and promotion prospects.

Abstract:This paper presents a underground circuit system solution based on the small diameter embedded systems. This solution collects the signal of the FOG IMU and accelerometers, and solvers the collected data. The underground circuit systems uses Manchester coding to realize halfduplex communication with the ground systems, encodes and decodes the data through ARM software programming, to achieve the remote communication with the ground systems. Practical tests show that this system is able to acquire signal of IMU and communicate with the ground system stably and reliably, and this system’s size is small, low power consumption, and can work in the environment with high temperature.

Abstract:Accuracy decrease is one of problems that restricting engineering application of fiber optical current transformer (FOCT). The function of FOCT is introduced. The influence of temperature on the measurement results were studied and the dualway temperature compensation algorithm based on least square method were discussed. And its feasibility was verified by experiment. Analysis and experimental results show that this method improves the performance of FOCT in the whole temperature range.

Abstract:In view of the problem that the time series similarity model based on Euclidean distance is less efficient and incomplete in morphology, the paper presents a similar model based on trend for time series. The model is based on piecewise linear representation and symbolic representation of time series, and the difference of time series is obtained by calculating the edit distance of the symbol string. At the same time, the model considers the time series length and the time series variation separately, expanding the use of the model. The experimental results show that the similarity model of time series based on trend is suitable for the similarity matching, and the efficiency is higher than traditional model which is based on Euclidean distance. Since the model emphasized on the similarity of morphology, it’s not sensitive to the deviation of time axis and white noise, and it’s suitable for the similarity matching of time series with different length.