共查询到20条相似文献,搜索用时 859 毫秒
1.
Introduction Rapid adaptation to environmental challenges is vitally important for bacterial survival and growth. One way in which bacteria control their response to changing environmental conditions is through the mechanism of two-component signal transd… 相似文献
2.
State-Space Equations and the First-Phase Algorithm for Signal Control of Single Intersections 总被引:1,自引:0,他引:1
State-space equations were applied to formulate the queuing and delay of traffic at a single intersection in this paper. The signal control of a single intersection was then modeled as a discrete-time optimal control problem, with consideration of the constraints of stream conflicts, saturation flow rate, minimum green time, and maximum green time. The problem cannot be solved directly due to the nonlinear constraints. However, the results of qualitative analysis were used to develop a first-phase signal control algorithm. Simula- tion results show that the algorithm substantially reduces the total delay compared to fixed-time control. 相似文献
3.
The single ion channel signal is an ionic current that can be recorded by the patch clamp technique,Hidden Markov model(HMM) algorithm has been used to convert the low signal-noise ratio(SNR) noisy recording into an idealized quantal one in the case of white background noise,The Traditional HMM algorithm is extended and adapted to the colored background noise.A new algorithm called EHMM(Extended HMM) algorithm is propsed,and mainly validated by simulation,Resultes show that it‘s effective. 相似文献
5.
A good voice-band signal classification can not only enable the safe application of speech ceding techniques, the implementation of a Digital Signal Interpolation (DSI) system, but also facilitate network administration and planning by providing accurate voice-band traffic analysis. A new method is proposed to detect and classify the presence of various voice-band signals on the General Switched Telephone Network (GSTN). The method uses a combination of simple base classifiers through the AdaBoost algorithm. The conventional classification features for voice- band data classification are combined and optimized by the AdaBoost algorithm and spectral subtraction method. Experiments show the simpleness, effectiveness, efficiency and flexibility of the method. 相似文献
6.
Signal propagations and linkages of subsurface temperature anomalies in the tropical Pacific and Indian Ocean 总被引:1,自引:0,他引:1
The propagation characteristics of signals along different zonal-time profiles are analyzed using surface and subsurface temperature anomalies over the tropical Pacific and Indian oceans. Analyses show that there are intrinsic relationships between El Nio events in the eastern equatorial Pacific and dipole events in the equatorial Indian Ocean. In the region of tropical North Pacific between the equator and 16°N, there is a circle of propagation of subsurface temperature anomalies. El Nio events only happen when the warm subsurface signals reach the eastern equatorial Pacific. Dipole events are characterized when a warm subsurface signal travels along off-equatorial Indian Ocean to the western boundary. From these analyses, we believe that subsurface temperature anomalies can be considered to be the oceanographic early signal to forecast El Nio events in Pacific Ocean and dipole events in Indian Ocean, respectively. 相似文献
7.
Distributed Signal Condition System for EAST Tokamak 总被引:1,自引:0,他引:1
In order to achieve both the signal condition remote control and the work statute self-check through Ethernet,a distributed signal condition (DSC) system has been developed for control and data acquisition (CODAC) in the EAST tokamak nuclear fusion experiment.Based on differential amplifiers,analog multiplexers and the embedded Ethernet communication technology,a DSC system is designed and produced.This paper summarizes the DSC system design,and presents a kind of calibration method for it.This DSC system has been integrated into the EAST CODAC system,and used successfully in the 2008 EAST experiments.The user-friendly,high performance,and cost-effective DSC system greatly improves the work efficiency and reduces the fault rates of the CODAC system. 相似文献
8.
IntroductionThe acoustic features of vehicle targets are animportant index for target recognition[13 ] ,butextensive data is needed to understand the acousticfeatures of vehicle targets.Target features can beacquired from existing test results or addition… 相似文献
9.
Interleukin-2(IL-2) is an important immunoregulatory factor. After the interaction between IL-2 and its receptor, intracellular signal molecules were activated and pro-oncogenes, e.g. c-Myc, c-Fos, c-Jun and Bcl-2 were induced, then cells stimulated with IL-2 would proliferate or differentiate. During these processes, IL-2 were internalized. The internalization of IL-2 mediated by IL-2R decreases the number of IL-2R on cell membranes, and makes extracellular IL-2 enter cells and degrade. It will down-regulate IL-2 biological activities. In order to identify the IL-2R subunit responsible for IL-2 internalization, chimeric IL-2Rs which consisted of different endocellular domains and extracellular domains from various IL-2R subunits were constructed. After they were transfected into L929 cell line, the IL-2 internalization was detected. Results showed that intracellular domains from IL-2R α and β subunits could not mediate IL-2 internalization alone; the signal for IL-2 internalization was located only in the endocellular domain of IL-2R γ subunit. Furthermore, IL-2 internalization extent would be affected by affinity between IL-2 and IL-2R. 相似文献
10.
《佛山科学技术学院学报(自然科学版)》2017,(2)
通过Signal Wizard 2.55仿真实验的技术手段,分别执行并分析了离线滤波、实时滤波和无限脉冲响应这三项任务。Signal Wizard 2.55仿真平台的功能和准确性通过实验得到了验证,从而为进一步的复杂实验设计提供了基础支持。同时,在使用Signal Wizard 2.55仿真平台的过程中出现的一系列技术问题和障碍也一一得到排除,这为将来的使用提供了有用的经验。 相似文献
11.
Totally Coded Method for Signal Flow Graph Algorithm 总被引:3,自引:2,他引:1
IntroductionThetopologicalarchitectureofasignalflowgraphcontainsthewholeinformationforgain termcalculationofthegraph .Ma sonformulajustreflectsthispointofview .Itisamarvelousdis coverythatthesearchingforallspecialgroupsofthefiguresinflowgraphcanobtainth… 相似文献
12.
13.
The EEG Signal Analysis Based on Wavelet Transform 总被引:2,自引:1,他引:1
14.
ZHOULi YANGXuan-dong LIKai-yang 《武汉大学学报:自然科学英文版》2004,9(4):463-467
Picture archiving and communication system (PACS) has played an important role in hospital and developed rapidly in recent years. It is an important part of PACS architecture that X-ray video output connects with PACS. In this paper, a method to digitize the video signals of X-ray facility is introduced. By means of the video capture card, we can acquire digital medical images from X-ray facility. The American College of Radiology (ACR) and the National Electrical Manufacturers Association (NEMA) developed a standard for Digital Imaging and Communications in Medicine (DICOM), this DICOM standard introduces a rule of medical image conversion from conventional format to DICA)M one. According to abovementioned standard, X-ray video signals can be connected to PACS easily. This project has been applied in some hospitals successfully and there is satisfied result. 相似文献
15.
为了解决现有Petri网分析工具(可达性树和矩阵方程)不能很好对扩展型Petri网进行分析的问题,提出用Signal语言对扩展型Petri网进行分析的方法.Sig-nal语言不仅能够解答扩展型Petri网安全性、有界性等问题,还能够直观地表示扩展型Petri网中各变量之间的约束关系及特性,更好地揭示网络的动态变化行为. 相似文献
16.
WEI Hui 《上海大学学报(自然科学版)》2004,10(Z1):149-153
Machine vision is an active branch of artificial intelligence. An important problem in this area is the trade-off among efficiency, accuracy and computation complexity. The human visual system can keep watchfulness to the perimeter of a viewing field while at the same time focus on the center of the field for fine information processing. This mechanism of appropriate assignment of computing resources can reduce the demand for huge and complex hardware structure. Therefore, the design of a computer model based on the biological visual mechanism is an effective approach to resolve problems in machine vision. In this paper, a multi-layer neural model is developed based on the features of receptive field of ganglion in retina to simulate multi-scale perceptive fields of ganglion cell. The neural model can maintain alert on the outer area of the image while capturing and processing more important information in the central part. It may provide valuable inspiration for the implementation of real-time processing and avoidance of huge computation in machine vision. 相似文献
17.
We present an alternative current-plasma display panel (AC-PDP) signal process and control circuit that fulfills the signal process and transform function. We proposed a novel driving logical waveform generator based on the SCI interface, which can real-time adjust the parameters to optimize performance of the PDP and facilitate the research and test. The use of nesting state-machine and parameterized design not only improves the resource utilization, but also makes it efficient and readable. The design has been written in synthesizable Verilog and fully verified using Xilinx FPGA device and applied in 42 - in AC- PDP module. 相似文献
18.
Signal overcomplete representation and sparse decomposition based on redundant dictionaries 总被引:5,自引:0,他引:5
ZHANG Chunmei YIN Zhongke CHEN Xiangdong XIAO Mingxia 《科学通报(英文版)》2005,50(23):2672-2677
In many signal processing applications, overcomplete representations, with their benefits of small decomposition coefficient and high flexibility, have lent an impetus to signal processing theory. Traditional methods based on orthogonal linear transforms are not suitable for the multi- ple components present in natural data. For example, it is hopeless to analyze a mixture of impulses and sinusoids with such a method, because each phenomenon needs its own appropriate basis. This would be simil… 相似文献
19.
Introduction Biomechanical analyses have shown that knee mo- ments vary considerably while walking on different terrain types[1,2]. Humans naturally adjust their mo- ments through visual or tactile feedback. The same ca- pability in a transfemoral prosthe… 相似文献