ECG放大器和QRS综合波检测器的研究

设计了一种高输入阻抗、三运放形式、带导联脱落检测电路的ECG放大器,和由起搏脉冲抑制电路、QRS综合波滤波电路、全波整流电路、峰值保持电路、自动增益控制电路、箝位电路、单稳态触发电路组成的QRS综合波检测器。经验证明具有较可靠的效果,可用于嵌入式智能便携心电监护仪中。

水下高速运动目标检测及其DSP实现

给出了水下高速运动目标的宽带模型,提出了基于小波变换的检测器。为了实时实现,给出了基于FFT的小波检测器快速算法。软件和硬件仿真结果证明,该检测器性能优良,能够利用ADSP21160来实时实现。

A new detector in EBPSK communication system

In order to raise the detection precision of the extended binary phase shift keying （EBPSK） receiver, a detector based on the improved particle swarm optimization algorithm （IMPSO） and the BP neural network is designed. First, the characteristics of EBPSK modulated signals and the special filtering mechanism of the impacting filter are demonstrated. Secondly, an improved particle swarm optimization algorithm based on the logistic chaos disturbance operator and the Cauchy mutation operator is proposed, and the EBPSK detector is designed by utilizing the IMPSO-BP neural network. Finally, the simulation of the EBPSK detector based on the MPSO-BP neural network is conducted and the result is compared with that of the adaptive threshold-based decision, the BP neural network, and the PSO-BP detector, respectively. Simulation results show that the detection performance of the EBPSK detector based on the IMPSO-BP neural network is better than those of the other three detectors.

AN EDGE DETECTOR BA SED ON WAVELET TRANSFORM FOR SAR IMAGE

Edge detecting is a f undamental issue in image analysis and image processing. In this paper, based on wavelet transform, an edge detector of SAR image is studied to serve the image aided navigation. Though wavelet transform is efficient as an edge detector, a l ot of false edges will be extracted from a SAR image, especially in areas of hig h reflectivity, with wavelet transform and a fixed threshold because SAR images are always contaminated by speckle. Therefore, this paper develops an algorithm by using a variable threshold with constant false alarm rates to help suppressin g the speckle in SAR images. Finally, two simulating tests are given and the res ults show that the effect of the multiplicative speckle is controlled and there are few false edges in the gotten edge images. Moreover, owing to the threshold from the wavelet transform coefficients, the algorithm can assure the real time of SAR image aided navigation.

Pure S-waves in land P-wave source VSP data

Conventional land vertical seismic profiling （VSP） exploration usually uses P-wave sources and three-component geophones for receivers, emphasizing P- and converted S-waves. Previous studies show that both dynamite borehole shots and vertical vibrations from controllable seismic sources at the surface will produce relatively strong pure P-waves and weaker pure S-waves. Interfaces with a large Poisson＇s ratio difference have a positive influence on the formation of strong transmitted converted S-waves. By a comparative analysis of pure S-waves from sources and converted downgoing S-waves, we believe that the main frequency of pure S-waves is usually lower than pure P-waves while the main frequency of downgoing converted S-waves is close to that of P-waves. We have studied zero-offset and offset VSP data from land P-wave sources. Results show that pure S-waves commonly exist in these data with differences in wave intensity. S-wave velocity can be obtained from the P-wave source zero-offset VSP data. Finally, we discuss the bright future of joint application of VSP P-and S-waves and the full use of S-waves in P-wave source VSP data.

Fault detection and identification for dead reckoning system of mobile robot based on fuzzy logic particle filter

To deal with fault detection and diagnosis with incomplete model for dead reckoning system of mobile robot,an integrative framework of particle filter detection and fuzzy logic diagnosis was devised.Firstly,an adaptive fault space is designed for recognizing both known faults and unknown faults,in corresponding modes of modeled and model-free.Secondly,the particle filter is utilized to diagnose the modeled faults and detect model-free fault according to the low particle weight and reliability.Especially,the proposed fuzzy logic diagnosis can further analyze model-free modes and identify some soft faults in unknown fault space.The MORCS-1 experimental results show that the fuzzy diagnosis particle filter(FDPF) combinational framework improves fault detection and identification completeness.Specifically speaking,FDPF is feasible to diagnose the modeled faults in known space.Furthermore,the types of model-free soft faults can also be further identified and diagnosed in unknown fault space.

Automated visual position detection and adjustment for optical waveguide chips and optical fiber arrays

The alignment coupling between optical waveguide chips and optical fiber arrays is the basis of the alignment coupling of planar optical waveguide devices, and the precise position detection with angle and spacing adjustments is one of the key steps of alignment coupling. A methodology for position detection, and angle and spacing adjustment was proposed for optical waveguide chips and optical fiber arrays based on machine vision. The experimental results show angle detection precision levels higher than 0.05°, line detection precision levels higher than 0.1 μm, and detection time less than 2 s. Therefore, the system developed herein meets the precise requirements necessary for position detection, and angle and spacing adjustments for optical waveguide chips and optical fiber arrays.

AN ADAPTIVE COLOR PLANE INTERPOLATION METHOD BASED ON EDGE DETECTION

In this letter, an adaptive interpolation algorithm based on edge detection is proposed. With this algorithm, all the missing green values can be reconstructed in Bayer pattern image by using edge detection interpolation method. Reconstructed images composed of green pixels are classified according to the high frequency components in image, and the threshold T needed for all kinds of green images in the edge detection is determined through experiments. The edge detection is carried out based on the one Dimensional (1D) gradient operator. If the gradient value is greater than T, this pixel is located on the edge; otherwise the pixel is in the smooth area of the image. Finally, the simple bilinear interpolation is used for the smooth area while the Laplacian interpolation with the second-order correction term is adopted to reconstruct the other red/blue values on the edge. This algorithm resolves effectively the conflicts between reconstructing high quality color image and reducing computational complexity, and thus largely enhances the processing speed for the reconstructed color image.

Calculation of Ge_(0.5)Si_(0.5)—Si Superlattice Photodetectors on Ge_(0.05)Si_(0.95) Waveguides:The Optimum Parameters

Abstract: The optimum parameters are calculated by the large cross - section theory and mode cut - off equation. The effect on reverse bias voltage is analysed by the doping concentration in n+ - Si. This is significant because the reverse bias increases sharply when the doped concentration in n+ - Si is less than 1 x 10~20 cm-3.

A Delay System Approach to Fault Detection Filter of Networked Control Systems

In this paper,the fault detection filter(FDF) design problem for networked control systems(NCSs) with both network-induced delay and data dropout is studied.Based on a new NCSs model proposed recently,an observer-based filter is introduced to be the residual generator and formulated as an H∞-optimization problem for systems with two successive delay components.By applying Lyapunov-Krasovskii approach,a new sufficient condition on stability and H∞ performance is derived for systems with two successive delay components in the state.A solution of the optimization problem is then presented in terms of linear matrix inequality(LMI) formulation,dependently of time delay.In order to detect the fault,the residual evaluation problem is also considered.An illustrative design example is employed to demonstrate the validity of the proposed approach.

An Efficient Adaptive Failure Detection Mechanism for Cloud Platform Based on Volterra Series

Failure detection module is one of important components in fault-tolerant distributed systems,especially cloud platform.However,to achieve fast and accurate detection of failure becomes more and more difficult especially when network and other resources' status keep changing.This study presented an efficient adaptive failure detection mechanism based on volterra series,which can use a small amount of data for predicting.The mechanism uses a volterra filter for time series prediction and a decision tree for decision making.Major contributions are applying volterra filter in cloud failure prediction,and introducing a user factor for different QoS requirements in different modules and levels of IaaS.Detailed implementation is proposed,and an evaluation is performed in Beijing and Guangzhou experiment environment.

2-D MULTIRATE ALGORITHMS FOR EFFICIENT IMPLEMENTATION OF EDGE DETECTION

Edge detection is a fundamental issue in image analysis. This paper proposes multirate algorithms for efficient implementation of edge detector, and a design example is illustrated.The multirate (decimation and/or interpolation) signal processing algorithms can achieve considerable savings in computation and storage. The proposed algorithms result in mapping relations of their z-transfer functions between non-multirate and multirate mathematical expressions in terms of time-varying coefficient instead of traditional polyphase decomposition counterparts.The mapping properties can be readily utilized to efficiently analyze and synthesize multirate edge detection filters. The Very high-speed Hardware Description Language (VHDL) simulation results verify efficiency of the algorithms for real-time Field Programmable Gate-Array (FPGA)implementation.

Design of Remote Control Nuclear Radiation Detector

For the issue of nuclear radiation detection,this paper designs a remote control nuclear radiation detector which can trace a pre-determined route,avoid obstacles effectively,and can be controlled remotely by users wirelessly or through voice command.It can effectively replace manual probing due to convenience,flexibility and safety.The system mainly consists of a nuclear detection module,a voice control module,a route tracing module,an obstacle avoidance module,a data transmission module,storage and a display module,and a D.C.machine.An MSP430 microcontroller is used as a control chip to control the motor and the system uses infrared technology and ultrasonic sensors to achieve intelligent tracing and obstacle avoidance.Moreover,it applies a voice module and data transmission module to remotely controlling the device.The radiation data is shown on an LCD screen.

Recent Achievement of Gas Electron Multiplier

Gas electron multiplier (GEM) as a novel gas detector,due to it’s simple structure,high performance,well compatibility etc.,is widely used in high-energy physics,nuclear physics and other fields.In this review,the principle,recent achievements,developments and applications of GEM are mainly described.

An all optical fiber gas sensor of NH3 and CO based on based on the spectral absorption and harmonic detection

An all optical fiber gas sensor is presented to detect the concentration of NH3 and CO. Based on the spectral absorption, The wideband light source is used to reflect two narrowband spectra by fiber grating of different duty. and piezoelectric ceramics to obtain narrowband output light. The high sensitivity detection can be measured from the second harmonic signal. The two narrowband spectra are corresponding to the absorption spectra of NH3 and CO. Concentration detection are realized by the detection of variety of light intensity. Sensitivity is proved and cost is reduced.

An Algorithm for Detecting Low-frequency Seismic Events and Preliminary Applications

An algorithm for detecting low-frequency seismic events is developed and applied to the detection of low-frequency events before the 2008 Wenchuan and the 2013 Lushan earthquakes. Continuous vertical-component waveforms of some broadband stations in the few months before the Wenchuan and Lushan earthquakes are processed by applying a bandpass filter in 2- 8Hz,and then converted to envelopes with a smoothing time of 10 s window and a median filter with a 20 min window. As a result,teleseismic,long-period noise and local small earthquakes are removed,the filtered amplitude is obviously larger than that of the noise and lasts for a dozen minutes to several hours during a few days in a few stations before the Wenchuan and Lushan earthquakes,respectively. The waveform and envelope are similar to that of a non-volcanic tremor( NVT). There are suspected NVT before the two earthquakes. Preliminary application demonstrates that this algorithm is potentially useful for extracting NVT signals from continuous seismic waveforms.

Development of a Seismometer-Type Absolute Displacement Sensor Aimed at Detecting Earthquake Waves with a Large Magnitude and Long Period

This paper proposes a novel seismometer-type absolute displacement sensor aimed at detecting earthquake waves with a large magnitude and long period. However, since the measuring range of the displacement sensor is higher than its natural frequency, it is difficult to detect low frequency vibrations below 1 Hz using a conventional a seismic-type displacement sensor. In order to provide an absolute displacement detection which is capable of lowering the natural frequency and enlarging the detectable amplitude without causing structural defects, the relative signals of displacement, velocity, and acceleration between a detected object and the auxiliary mass of the sensor are fed back into the sensor. In addition, phase lag compensation is inserted to adjust phase angles, which are of a frequency of 1 Hz. According to simulation results, a detection range from 0.1 Hz to 50 Hz is expected. It has been demonstrated that the developed sensor with a small size and light weight has a detection range of from 0.5 Hz to 50 Hz for absolute displacement and velocity. As an additional advantage, the measurement displacement amplitude has been expanded to about 20 dB. This sensor is available to use for the active control method. of flexible structures like high rise buildings using the LQ control

Development of a Lightning Warning System

A lightning warning system （LWS） which can predict the possibility of lightning strike and the position of lightning discharge was developed. The LWS uses the electric field intensity at the ground as a parameter to warn the possibility of lightning strikes. A planar shutter type electric field mill （EFM） with a rotating vane is studied to measure the electric field. From a calibration experiment, the sensitivity of the EFM was adjusted to 0.15 V/kV/m, and this covers the ranges from 200 V/m to 20 kV/m. Magnetic field waveform is detected by a crossed loop coil and an integral amplifier. Frequency bandwidth of the circuit ranges from 5 kHz to 1.2 MHz. The polarity of lightning discharges is discriminated by electric field component. After fixing the polarity, we can calculate the direction and distance of lightning discharge by the peak and the zero cross time of the detected magnetic field waveform.

Power Electronic Interface with Islanding Detection and Unbalanced Fault Ride-through Capability

Power electronic interface of dispersed generation plays a very important role in connecting a dispersed generation with utility grids. A power electronic interface not only adjusts the amount of active and reactive power injecting into a grid but also implements other importance duties as well. In this study, negative-sequence current injection has been fulfilled in three-phase power electronic interface for two important duties besides injecting reference power into utility grids. The first one is for islanding detection, and the other one is to enhance unbalance-fault ride-through capability of dispersed generation. This paper introduces a mechanism of negative-sequence injection based on controlling two separate coordinates of dq-control and explains the effect of negative-sequence injection in limiting the unbalanced currents generated from a dispersed generation. Using adaptive notch filter as a signal processing unit for the three-phase system, negative-sequence components are observed. The performance of entire control system is evaluated by time domain simulations, PSCAD/EMTDC （power systems computer aided design/electromagnetic transients including DC）.

金振口服液HPLC-UVD-ELSD特征指纹图谱及13个成分同时定量的整体质量控制研究

目的建立金振口服液(Jinzhen Oral Liquid,JOL)高效液相色谱-紫外真空波-蒸发光散射检测器(HPLC-UVD-ELSD)特征指纹图谱,结合13个主要代表性成分(没食子酸、甘草苷、芦荟大黄素-8-O-β-D-葡萄糖苷、甘草素、黄芩苷、白杨素-7-O-β-D-葡萄糖醛酸、千层纸苷、汉黄芩苷、大黄酚-1-O-β-D-葡萄糖苷、大黄酚-8-O-β-D葡萄糖苷、甘草酸、猪去氧胆酸、胆酸)同时定量的方法,对市售制剂进行整体质量控制。方法采用Cosmosil-C18色谱柱(250 mm×4.6 mm,5μm);检测波长为254nm;ELSD漂移管温度115℃;载气体积流量2.0L/min;以甲醇-水(含0.1%甲酸)为流动相进行梯度洗脱,建立JOL的HPLC-UVD-ELSD特征指纹图谱,对主要特征峰进行明确化学指认并确定组方中药来源,运用相似度软件对15批市售制剂进行相似度评价,同时在市售制剂批间差异小的前提下测定主要代表性成分的含量。结果建立了JOL的HPLCUVD-ELSD指纹图谱结合13个代表性成分同时定量的方法;覆盖该复方4味组方中药的15个主要特征峰得到明确化学指认,分别为没食子酸(1号峰)、甘草苷(5号峰)、芦荟大黄素-8-O-β-D-葡萄糖苷(7号峰)、甘草素(11号峰)、黄芩苷(13号峰)、白杨素-7-O-β-D-葡萄糖醛酸(16号峰)、千层纸苷(17号峰)、汉黄芩苷(18号峰)、大黄酚-8-O-β-D-葡萄糖苷(19号峰)、大黄酚1-O-β-D-葡萄糖苷(20号峰)、大黄酸(24号峰)、甘草酸(26号峰)、(18β,20α)-甘草酸(27号峰)、猪去氧胆酸(28号峰)、胆酸(29号峰),并初步确定了29个特征峰的组方中药来源分别为8、12、13、15~18号峰归属于黄芩,3~5、10、11、25~27号峰归属于甘草,1、6、7、9、14、19、20、24号峰归属于大黄,2号峰归属于平贝母,28、29号峰归属于人工牛黄,21~23号峰归属于辅料;15批市售制剂的指纹图谱与对照指纹图谱的相似度值在0.968~1.000;13个定量成分线性关系良好(R2=0.9990~0.9999),且平均回收率为96.90%~102.84%,15批市售制剂定量成分的质量浓度分别为没食子酸51.82~148.27μg/mL、甘草苷75.04~130.00μg/mL、芦荟大黄素-8-O-β-D-葡萄糖苷31.72~39.84μg/mL、甘草素14.24~43.65μg/mL、黄芩苷610.37~867.40μg/mL、白杨素-7-O-β-D-葡萄糖醛酸12.87~34.09μg/mL、千层纸苷62.45~101.48μg/mL、汉黄芩苷155.41~205.86μg/mL、大黄酚-1-O-β-D-葡萄糖苷11.56~23.72μg/mL、大黄酚-8-O-β-D葡萄糖苷16.14~36.87μg/mL、甘草酸222.97~310.32μg/mL、猪去氧胆酸177.48~239.70μg/mL、胆酸98.54~132.85μg/mL。结论所建立的金振口服液HPLC-UVD-ELSD特征图谱和定量测定分析方法为进一步提升制剂整体质量标准提供了重要证据。