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1.
As a kind of data compression technique of high efficiency, arithmetic coding is widely used in image compressing. This paper introduces the adaptive binary arithmetic coding used in the new international standard of still image compression named jpeg2000. The implementation of arithmetic coding depends on high power digital signal processor.Fast adaptive binary arithmetic coding and optimized assembly program design are discussed, and its practicability and efficiency are proved.It also can be used in other fields that need compressing data.  相似文献   

2.
基于压缩编码的加密方式能够同时完成加密和压缩的功能,通过压缩减少了信息的冗余,同时引入加密使对试图推测出明文信息和找到密钥的攻击具有非常好的鲁棒性。提出了一种基于随机区间置换的安全算术编码,在编码过程中通过随机密钥保证图像压缩编码的安全性,且不影响编码的效率,使其方便在网络中安全传输。实验结果和安全性分析表明该安全算术编码有较好的安全性和加密效率。  相似文献   

3.
It's necessary to process position and gesture of rocket on real time within the flight of rocket. This work should base exact data. But much noise has been found in the data and the noise recognize is regarded as a focus. A speedy online arithmetic recognizing noise is proposed based on wavelet transform. The computing complexity measured by time of this arithmetic is a constant which is greatly reduces the works of calculation of wavelet transform. It can recognize the noise fast when the signal is gathered. The applications in these problems show that the effective arithmetic satisfies the needs of real time and can handle the real time data measured in other yields.  相似文献   

4.
A logistic map controlled secure arithmetic coding is proposed, the Logistic map is used to control the order of the symbols in the model and change the probabilities of the symbols, which is applied to the image encryption. The proposed scheme makes the image transmit more secure and comfortably on the Internet, and that is done at little expense in terms of coding efficiency. In the coding process, it ensures the uniformity of the model being changed by the chaotic sequence, thus to meet the security requirements of image compression. The algorithm can be applied to any arithmetic codec based on multimedia data including video, image and audio. Its most strength compared with other cipher mode is that, there is a significant reduction in the redundancy of information during the compression process, and it is robust when attempting to estimate the information of the image and discovering the key. The scheme can effectively resist differential analyses from both cryptography and coding.  相似文献   

5.
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.  相似文献   

6.
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.  相似文献   

7.
A Context Model of Wavelet Coefficients for Image Compression   总被引:1,自引:0,他引:1  
Through the combination of the idea of the linear prediction used in the GlicBawls coding scheme and the idea of the quantization taken in the CALIC coding scheme to reduce the number of contexts, a new context model of wavelet coefficients for image compression is proposed. Wavelet coefficients are encoded by the arithmetic encoder, with the contexts formed by quantizing linear prediction values. Experimental results show that the model achieves higher lossless compression rate of image than lossless SPIHT and lossless EBCOT used in JPEG2000. In addition, by exploiting the multiresolution property of wavelet, the model can compress the transformed image for progressive resolution and earn higher compression rate for each scale of the image than EBCOT.  相似文献   

8.
Presently, ECG monitor encounters the trend of miniaturizing, intelligentizing and networking. Short distance and limited channels are shortcomings of the existed telemetric ECG (Electrocardiograph) monitoring system, while the existed remote monitoring system has the disadvantages of high cost and low Data Transfer Rate. Furthermore, neither of these two systems can implement real-time monitoring on the spot. So, an embedded ECG Monitor based on Linux, which successfully solves these problems, is introduced. With embedded system technique, this embedded monitor, which can not only realize real-time monitoring on the spot, but also analyse the ECG data, has the advantages of low cost, small volume, light weight, low power, high stability, powerful networking function and so on. And by communicating through Internet, which has the features of low cost, high data transfer rate and good expandability, it can also send ECG data to monitoring center in order to achieve long-term monitoring. The development of this monitor provides a new solution for medical instruments' implementation and networking, and is of certain reference value.  相似文献   

9.
In this study, nine simplified short composite columns consisting of core CFST (concrete filled steel tube) of different diameters and outer reinforced concrete were constructed to study their compressive performance under axial or eccentric compression. The failure mode is characterized by the crush of the outer concrete. The bearing capacity increases at first and then decreases with further increase of the position coefficient. It can be concluded that position coefficient is an important structural parameter that has considerable influences on the ultimate bearing capacity of the composite columns. The outer concrete, steel tubes and longitudinal reinforcement are found to work in a cooperative manner under axial or eccentric compression when the position coefficient is about 0.5. An improved bearing capacity algorithm that takes the position coefficient into account has been proposed based on the experimental and simulation results and current technical specification in China. It has been proven to be precise and safe.  相似文献   

10.
During data collection,the experimental data such as curve of force versus displacement are usually disturbed by the environmental uncertain signals,which cause the data to drift greatly.Since the drift is stochastic,uncertain,and has distorted the real experimental curve severely,it brings lots of difficulties in analyzing the experiment results.In this paper,based on the characteristic of the stochastic disturbance signals,a three-phase digital filter arithmetic is given,in which the disturbance signals are filtered in each phase gradually,according to the different filter methods,and then the real curve is reappeared again.Two idiographic and different instances are adopted to prove the validity of the arithmetic at the end.  相似文献   

11.
Aiming at the shortcoming of modern power plant flame image inspect system that is based on on_off logicals,the article design a new power plant flame image inspect system based on general video capture hardware. A best optimize image segmentation arithmetic is given for image pretreatment. Based on human cognize character, the paper puts forword a Weightiness Amend Coefficient(WAC). for the purpose of enhancing the intelligent and auto_adoptions to complex combustion condition, a new Cluster Center Initiative Optimize and Auto_adoptions Rework arithmetic is put forword. At last, the experimentation result is given.  相似文献   

12.
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.  相似文献   

13.
针对作物区域试验中的品种均值估计问题,根据混合线性模型的一般原理,总结和提出多种加权最小二乘估计 (WLSE)和最佳线性无偏预测(BLUP)的方法,推导了这些方法的平衡数据计算简式;同时,利用14套2年多点的棉花区试资料和一套4年多点的棉花品种试验对这些方法的预测效果进行验证比较.结果表明,与算术平均值相比,以环境内误差方  相似文献   

14.
This paper introduces the software and hardware designs of minitype gas dynamotor system based on ATMEGA8L singlechip. Step motor is used as the executing equipment in the system. The maximum power of the dynamotor is 5 kW. First, the speed of the dynamotor is sampled, and then the signal is send to the ATMEGA8L singlechip, so as to drive the step motor, thus to control the accelerograph, and to control the frequency of the 9atput voltage, and the main arithmetic is the PID algorithm. The result shows that this technology can be used and extended in producion.  相似文献   

15.
The probabilistic model of resistance in the current unified standard for reliability design is imprecise for RC members subjected to eccentric compression. The reason is that it lacks full considerations of influences of varying eccentricities. An improved probabilistic model of resistance with different eccentricities and reinforcement ratios is obtained by using the Monte Carlo sampling method and the current probabilistic models of all resistant factors. The results indicate that it is accurate to fit the probabilistic distribution of resistance with normal distribution. Given that, the applicability of the improved model is analyzed for reliability analysis of RC members subjected to eccentric compression with random eccentricities. It shows that when the design value of eccentricity is close to or larger than the eccentricity producing balanced failure, there would be large errors in reliability analysis if the probabilistic model of resistance given in the current reliability unified standard is used. However, it is accurate when using the proposed probabilistic model. The results also show that the design of RC members subjected to large eccentric compression is unsafe based on the current reliability unified standard because it lacks full considerations of effects that the resistance decreases as eccentricity increases.  相似文献   

16.
线性混合模型最佳线性无偏预测(BLUP)不仅适用于数据不平衡和误差方差异质试验的分析,而且对随机效应的排序会更准确。在实际试验分析中由于真实方差参数值未知而采用估计值时,BLUP转变为所谓经验性BLUP(eBLUP)。为了探讨eBLUP在作物区域试验品种评价的效果,本文以我国2012—2014年长江流域油菜区域试验12套产量资料为例,对eBLUP在品种主效应和特定环境中效应的估计、排序及差异比较t测验等方面与方差分析综合比较。结果表明,对品种主效应,eBLUP与方差分析算术平均值仅有较小差异,品种排序在eBLUP与算术平均值法相同;对特定环境中品种效应,eBLUP与算术平均值法有较大差异,品种排序在eBLUP较算术平均值法更准确;用Kenward-Roger法估算基于eBLUP的效应差异t测验的自由度,无论对品种主效应还是对特定环境中品种效应,eBLUP和方差分析有着相近的显著性(α=0.05)测验效果。  相似文献   

17.
In With one-storey, two-span prestressed frames, a comparative study is done between under vertical and horizontal loads. The studies include the pattern of the plastic hinges occurring and, the demanded and available rotational capability of the hinges in critical sections. The relative height of compression zone and prestressed degree are considered. The result indicates that there is much difference in the pattern of the plastic hinge occurring when each plastic hinge has enough rotational capability. The beams can finish a full redistribution of internal force under vertical loads, but not under horizontal loads. Moreover, as increasing of the relative height of compression zone, a stronger rotational capability of hinges will be demanded to finish a full redistribution under vertical loads when a weaker rotational capacity will be needed under horizontal loads.  相似文献   

18.
机载 LiDAR生成DEM的一些关键问题评述   总被引:1,自引:1,他引:0  
刘峰  谭畅 《中国农学通报》2013,29(2):202-206
提取DEM是机载LiDAR技术应用研究关键内容之一,从LiDAR数据滤波、DEM模型选择、内插、误差控制和数据压缩等几个方面,分析当前利用机载激光雷达数据提取DEM的主要研究进展.着重讨论插值滤波、倾角滤波和形态学滤波算法,定量分析滤波算法的性能;分析比较确定性内插方法和地学统计内插方法,并指出内插方法在提高精度同时也要考虑稳定性和序同构性;论述DEM格网压缩和三角网压缩方法,并指出在满足地形可视化需要的同时提高压缩效率;并进行了总结展望,为相关研究提供参考.  相似文献   

19.
Aiming at solving the matter of fact of manufacture errors on worm, the worm test apparatus is studied by the tool research department in Chengdu.A kind of improved principle,hardware and software design of the project is discussed. The primary aim of the single chip microcomputer circuit of this project is data collecting, and the invention monopoly of professor Zhangguanghui of Chongqing university is applied. The high frequency inserted pulse is used, and the software is joined in constitute subsidiary calibration distributed on equal time. The task of online subdivision in the dynamic measure process is completed. The data are passed to PC, PC handle them and examination result is gotten. The integration of the process is very high, and the tedious and complicated hardware circuit is simplified like the tradition examination method.  相似文献   

20.
DV-Hop算法中,平均每跳距离是影响定位精度的因素之一。针对平均每跳距离带来的定位误差,对锚节点和未知节点的平均每跳距离进行了改进和优化。首先引入遗传算法计算锚节点的平均每跳距离;然后利用跳数小于等于3的锚节点的平均每跳距离加权处理未知节点的平均每跳距离,减少平均每跳距离带来的误差。仿真结果表明,在不增加硬件开销的基础上,改进算法能够有效提高算法的定位精度,并且具有较好的稳定性。  相似文献   

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