QRS complexes detection using quadratic b-spline wavelet transform algorithm

Aiming at the low accuracy and low adaptability of wave detection, a QRS complexes detection algorithm is proposed based on quadratic b-spline wavelet, while combined with binary search algorithm and arc approximating curve algorithm. The signal is decomposed with quadratic b-spline wavelet through Mallat algorithm and the R wave is detected by adjusting the threshold with binary search and modulus maximumizing. The T wave and P wave are detected by using arc approximating curve algorithm based on the least square. This algorithm is certified with the ECG signals from MIT-BIH database and is demonstrated that the algorithm enhanced the adaptability of R wave detection and improved the accuracy of T wave and P wave detection. The simulation experiment shows that the improved algorithm can effectively improve the automatic detection capabilities of ECG signals.     

Choosing Method of Wavelet Neuron Based on ECG Data Compression

The paper discusses a wavelet network for the ECG data compression and proposes the method for choosing its wavelet neuron.According to the spectrum range of the ECG data,we decide the time-frequency field of ECG.And the time-frequency field of wavelet is also determined by the spectrum range of it.The wavelet neuron is fixed preliminarily by the first two steps.Then the preliminary wavelet neuron is screened by using OLS algorithm.We choose Morlet as the mother wavelet,and use the ECG signal to validate by the method.The result demonstrates that the number of Morlet whose spectrums locate at the ECG's is up to 152.But after screening by the OLS algorithm,it reduces sharply.This method can make the size of the wavelet network driving to optimum and also reduce the training time of the wavelet network sharply.     

Fetal electrocardiogram extraction based on radial basis function neural networks

A novel method for extracting fetal electrocardiogram (FECG) from the abdominal composite signal of a pregnant woman is proposed. The maternal component in the abdominal electrocardiogram (ECG) signal is a nonlinearly transformed version of the mother's ECG (MECG). This nonlinear relationship was identified using radial basis function (RBF) neural networks. The FECG is extracted by subtracting the nonlinearly transformed version of the MECG from the abdominal ECG signal. The baseline shift and noise in the FECG are suppressed by wavelet packet denoising technique. Experimental results obtained from the actual ECG signals demonstrate the effectiveness of the proposed method in extracting FECG even when it is totally embedded within the maternal(QRS) complex.     

Correlation Dimension Analysis on Heart Rate Variability Signal

Heart rate variability is an important index to express the tensility and balance of the parasympathetic-sympathetic nerve, and it is valuable to diagnose heart and blood disease in clinical diagnosis. It is approved that HRV signal possess non-linear characteristic, and we can analyse and present HRV signal with non-linear dynamic parameteres, such as fractal dimension. Based on phase-space reconstruction theory, an improved algorithm is introduced to calculate the correlation dimension of HRV signal, and some valuable conclusions are expressed according to the result which is concluded from the correlation dimension of nearly 30 samples.     

Detection Method for R-Wave of ECG Signal With Wavelet Transform

The R-wave of ECG signal represents the electrical activation of the ventricles, which initiates ventricle contraction, and the typical peak value singular signal, so the R-wave of ECG signal is localized precisely and analyzed accurately using the wavelet transform. The principium of the precise detection method for R-wave in ECG signal is researched. The special properties of Mexican hat wavelet in time-domain are analyzed, too. This wavelet has every order continuity, symmetry, exponential attenuation and one vanishing moment. For this reason, the mexican hat wavelet basis has the excellent localization and analyzing precision. Using the MIT/BIH (Massachusetts Institute of Technology / Boston's Beth Israel Hospital) Arrhythmia Database and the applications in clinic, the precise detection method can detect accurately and localize precisely to the R-wave in ECG signal in the serious noise signal. This method has the quite high locating precision (its error is not more than one sampling point and the points of the R-wave in ECG signal about 80 percent are localized precisely) and analyzing accuracy (no accumulative error). The real-time of the method is excellent, and the real-time detection to the R-wave of ECG signal can achieve using this method.     

The Application of Fractal to Submicron Particle Sizing

Brownian Motion is one of the important characteristics of submicron particles.On the basis of observatiorl for Brownian motion of particles,the authors present a medel to describethis physieal process by usin g fractal theory a nd this medel is proved to be valid in theory.Throughfurther an alyzing,we establish the relationship between fractal characteristics and particle sizeparameters.Combining image signal processing technique,particle size information can be obtainedby computing fractal dimension values,and then a new method for particle sking will be developedinfuture.     

汽车转弯自动照明控制系统数据采集滤波方法

为了减少汽车转弯自动照明控制系统数据滤波处理中的延时,在滑动中值滤波方法基础上,提出了一种带补偿的限幅滑动中值滤波算法,通过补偿的方式跟随信号的变化趋势。该算法通过2个步骤完成滤波,先对数据进行带补偿方式的限幅处理,再进行滑动中值滤波处理。该算法综合了滑动中值滤波法的实时性以及限幅滤波法对偶然性干扰滤除的有效性,实现更准确的滤波。仿真与实测结果表明,与滑动中值滤波方法相比较,改进后的算法滤波能够实时地滤除数据中的干扰,处理时间可减少62%,滤波效果较好,且速度信号的数据滞后时间较短,实时性较高,满足系统设计要求。     

Audio blind watermarking scheme combined DWT DCT QR

In order to protect the copyright of digital audio and video in Internet, we propose a novel audio blind watermarking scheme combined discrete wavelets transform, discrete cosine transform, QR decomposition and audio characteristics. In this algorithm, the audio are split into blocks, and each block are decomposed on two dimensional discrete wavelet transform (DWT), then the approximate sub band coefficients are decomposed on discrete cosine transform (DCT), and the first quarter of the DCT coefficients are decomposed on QR decomposition and get a triangle matrix. At last, the watermarking information is embedded into the triangle matrix. The experiments show that the algorithm can get better balance between transparency and robustness of watermark, and it has strong robustness against the common audio signal processing such as additive white Gaussian noise, re sampling, re quantization, low pass filter, MP3 compression and cutting replacement.     

Development of an apparatus for testing heat-resistance time of combustible devices

Based on the characteristics of combustible cartridge case, a test method for heat-resistance time of minor-caliber rapid-fire gun with high rate of fire is proposed and test apparatus prototype is developed. The method is to do the flame detection through the use of photomultiplier tubes combined with optical fiber and detecting smoke by using the infrared and receiver combined with optical fiber. The test experiments show that the apparatus can effectively test the signal smoke and flames. Moreover, it can be applied to the heat-resistance test of other nonmetallic materials.     

Sampling Technique of ECG Signal in Windows98

A method of real time sampling and data processing of ECG signal in Windows98 is introduced in this article. It makes the data collecting and processing easy by driving the A/D transforming card with the Vxd programmed with VtoolsD and VC++, drawing the curve of ECG on memory DC, and utilizing the virtual memory technique to realize the data storing.     

不同种植布局对稻瘟病孢子发生量的影响研究

为研究水稻不同种植模式对稻瘟病发生影响,通过试验设计、采样设计,以稻瘟病病原菌为研究对象。通过定时捕捉稻瘟病病原菌孢子,并与温度、光照强度、相对湿度、不同试验区间进行研究分析。试验结果表明：孢子量变化与温度、光照强度和相对湿度呈正相关;同一种植模式及布局接壤的试验区孢子量变化间呈显著正相关;研究还发现多样性种植的试验区孢子总量略低于单一种植的试验区孢子总量,说明多样性种植能较好地抑制稻瘟病的发生。同时,利用分形理论研究了整个试验区的分形维,研究表明：分形维为小数,说明整个试验区具有一定的混沌特性。     

Direction of Arrival Estimation for CDMA Communication Signal

MUSIC algorithm is often applied in direction of arrival estimation of communication signal or radar signal. But the traditional MUSIC algorithm is not applicable in the presence of the correlational signals. Combining with time average processing, an algotithm of two-dimensional space-time average is suggested on the base of space average technic especially for the DOA estimation of CDMA communication signal. A detaild analysis and a conclusion about this improved algorithm is presented. Ensuring the accurary of the estimation an efficient decrease in quantity of operation is achieved with the algorithm, so it is more suitable for real-time processing. The efficiency of the improved algorithm is attested by the emulating results.     

Portable ECG Monitor Front- ended Design with C8051 F020

The electrocardiogram (ECG) signal is a recording of the electrical activity on the body surface generated by the heart frequency of which is weak and low. Many researchers devote themselves to get more perfect ECG in many ways. This article introduces the characterize of an ECG signal , then discusses the requirements for the sampling circuit of an ECG. Since there are some shortcoming in common design means, the authors give an effective circuit. The system is composed of a low-cost , low-power and high-performance MCU C8051F020 , amplifier AD620 , right-leg drive circuit ,communication circuit and power management circuit. Then software design is given which is used to sampling and filtering ECG signal. Levkov filter arithmetic and smooth filter arithmetics are used in this design. In the end , the authors advance a distributing and networking ECG monitor system.     

ECG Signal Acquisition Instrument Based on USB 2.0

An electrocardiogram (ECG) is an essential way for diagnosing the heart disease, and the test theories and systems work well with the practice application, whereas, as new technologies and devices come forth one after another, it allow us to acquire the ECG data more conveniently, more accurately, more comprehensively. The authors discuss the design of ECG data acquisition system based on the USB 2.0 protocol, and expatiates the system principle in detail. The system employs two AD73360 to sample the standard 12-lead signal simultaneously, which has a resolution of 16-bit. They utilize EZ-USB FX-2 as the USB interface device, which can transfer the data conveniently and quickly, and also permit the configuration of multi-system controlled by just one host. Considering the DSP as a powerful tool in the field of digital signal processing, ADSP-2181 has been chosen.     

A time-varying signal processing method for Coriolis mass flowmeter

The mass flowrate of Coriolis mass flowmeter in practical application has slow changes with time. To solve the problem, an improved time-varying signal model whose frequency, amplitude and phase are time-varying based on the random walk model is established firstly. A new algorithm of adaptive notch filter with the capability of tracking frequency variation is applied to filter the sensor output signal of Coriolis mass flowmeter and its frequency is calculated next. An adaptive line enhancer based on the mentioned notch filter extracts fundamental frequency signal from noisy data. Then, by short window intercepting, the revised sliding DTFT recursive algorithm is introduced to calculate the real-time phase difference between two enhanced signals. With the frequency and phase difference obtained, the time interval between the two signals is calculated and then the mass flowrate is derived. The simulations and field test results show that the proposed method can not only track the change of frequency and phase, but also ensure the calculation accuracy when measuring small phase difference. The computational load of the algorithm is simple so that it can be applied to real-time signal processing for Coriolis mass flowmeter.     

Application of Fractals in Architectural Shape Design

A computer aided method for architectural shape design was developed based on the L systems algorithm, the shape grammar and the space surface equation theory. Various 3D entities such as building grounds, building walls and building domes with fractal characteristics could be generated in a short time by using the computer program. These generative 3D entities were saved in a component database which could help to accumulate design knowledge through continuous expansion. A building could successfully be formed by the designers through selecting proper building grounds, walls and domes from this database. The effectiveness of the proposed method was approved with a case study.     

A Fast One-Step Scanning Thinning Algorithm

A new quick thinning algorithm was presented in this paper,which assigneddifferent weights to different pixels near the skeleton pixels and rules out the im possible pixels in thethinning procedure. It needs neither iteration on pixel panel nor detection on every pixel such thatthe time consumed is greatly lessened. A filling algorithm is also offered for better results.Experiment on variety of binary patterns showed that it could get both a high speed and a goodskeleton shape compared with other algorithms,This new algorithm reaches perfect result.     

The Application of Fuzzy Neural Network in the Detection for Moving Object

A fuzzy neural network(FNN) of detection for moving object based on BP algorithm is described in this paper.The correctness of the FNN in signal detection for moving object and fault diagnosis for instrument is proved by experiments.     

Application of Wavelet & Multi-Resolution Analysis to Detection of the Time of PN Code Acquisition

In the field of CDMA system, DS-SS technology has been used widely. Thereby, a great deal research on acquisition method of PN code is based on DS-SS. In the traditional way, the power detection method of judgment is used widely. Based on the characteristic of PN code acquired signal (namely BPSK signal or QPSK signal) and characteristic of un acquired signal (namely white Gaussian noise), this paper introduces the wavelet detection method of PN code acquisition time. Meanwhile, the performance of wavelet threshold is also studied. In the end, the statistics of parameters in this detection method is made. The result indicates that the wavelet & multi resolution has practical value in the signal processing.     

Improved Signal Detecting Algorithm for Burst Communication

Signal detecting is the first task for Burst communication. The paper proposes an improved double sliding window algorithm to detect burst signal based on the feature of preamble sequence. Additionally, theory analysis and computer simulation of the improved algorithm are also made in several typical channels. At last, the algorithm is realized with FPGA, and the result indicates that the improved algorithm can detect burst signal only within the time of 6 symbols, obviously improving the capability of signal detecting algorithm.