共查询到20条相似文献,搜索用时 93 毫秒
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混沌在数字通信领域至少有3个方面的应用前景,即压缩、调制、加密。本工作主要讨论加密的应用。国外虽已有一些利用混沌加密数字通信信号的方法,但仅是在密码编码学的边缘徘徊。本工作首先分析了混沌映射和密码编码的联系和区别,以便明确混沌理论和密码编码学之间关系,这将有助 相似文献
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利用数字FIR滤波器和正比于系统变量的脉冲反馈法的级联控制非线性连续系统中的混沌和超混沌。以实数Lorenz系统和复数洛仑兹-哈肯系统为例进行了数值研究。结果表明:FRI-PPSV级联控制法比仅用FIR滤波法或PPSV法更能有效地控制非线性连续系统中的混沌和超混沌,且抗噪性能PPSV法有显著提高。 相似文献
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在实际工程中,将一个稳定周期系统驱动到另一个周期态去,必须用足够大的外力才能实现,这就要消耗足够大的能量。混沌反控制则可使系统处于混沌状态,然后获得混沌系统的吸引子具有无穷多的周期态,就可用极小的代价来实现混沌控制,从而达到所需要的稳定周期态。这样,不仅不必回避系统出现的混沌运动,而且在可能条件下人为地将系统首先引导到混沌状态下,然后对这种混沌系统施加某种混沌控制方法,使系统在无穷多规则态的态库中进行自由选择和自由转换,实现目标轨道的灵活选择,这正是混沌控制较其他控制最为显著的优点之一。 相似文献
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Chua电路混沌系统的同步分析 总被引:1,自引:0,他引:1
Chua电路是混沌系统中倍受人关注,具有广阔应用前景的混沌电路,如何同步混沌系统是应用的前提条件,用三种方法分析了Chua电路混沌系统的同步问题,为在电路上实现Chua电路混沌系统的同步提供了理论基础和技术指导。 相似文献
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方锦清 《中国原子能科学研究院年报》2004,(1):106-106
本工作主要考虑一个由N个相同节点组成的典型动态网络,每个节点是一个n维的动态系统,节点之间通过第1个变量差的非线性反馈耦合起来。以质子横向束晕.混沌包络方程为节点的动力学,实现了动态束流传输网络中的混沌同步。单个节点系统的状态方程为。 相似文献
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本工作以国内外在混沌序列密码和单向Hash函数及分组密码方面的一些研究进展,包括基于一维无限折叠映射的前馈型序列密码、基于m序列扰动的混沌序列密码、基于数字滤波器结构的混沌序列密码、基于混沌序列驱动的序列密码以及单向Hash算法的研究等为据,进行混沌密码编码研究。 相似文献
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本工作讨论了混沌映射与密码编码算法间的相似性和区别,研究了将实数集上的实数映射成一个有限集上的整数的方法,这是完成混沌密码编码算法的重要一环。提出了混沌映射的一种取尾数密码编码方法,并对3种混沌映射使用尾数编码法所产生的密码分别做了随机性验证,说明了这种方法是可行的。 相似文献
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A bunch arrival-time monitor(BAM) system,based on electro-optical intensity modulation scheme, is under study at Shanghai Soft X-ray Free Electron Laser.The aim of the study is to achieve high-precision time measurement for minimizing bunch fluctuations. A readout electronics is developed to fulfill the requirements of the BAM system. The readout electronics is mainly composed of a signal conditioning circuit, field-programmable gate array(FPGA), mezzanine card(FMC150), and powerful FPGA carrier board. The signal conditioning circuit converts the laser pulses into electrical pulse signals using a photodiode. Thereafter, it performs splitting and low-noise amplification to achieve the best voltage sampling performance of the dual-channel analog-to-digital converter(ADC) in FMC150. The FMC150 ADC daughter card includes a 14-bit 250 Msps dual-channel high-speed ADC,a clock configuration, and a management module. The powerful FPGA carrier board is a commercial high-performance Xilinx Kintex-7 FPGA evaluation board. To achieve clock and data alignment for ADC data capture at a high sampling rate, we used ISERDES, IDELAY, and dedicated carry-in resources in the Kintex-7 FPGA. This paper presents a detailed development of the readout electronics in the BAM system and its performance. 相似文献
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赖祖武 《核电子学与探测技术》1990,10(5):295-300
本文扼要地介绍抗辐射电子学的主要内容,并回顾了这门新科学在我国的发展概况。由于电子器件及系统对于核或空间辐射以及核电磁脉冲十分敏感,它们必须进行加固以保证在空间及强辐射环境中能生存和正常工作,因此逐渐形成了抗辐射电子学这门新的核电子学分支。 相似文献
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Schwaller B. Hoffmann C. Drouhin F. Pallares A. Fontaine J.C. Benhammou Y. Charles F. Huss D. 《IEEE transactions on nuclear science》1998,45(5):2314-2318
The trigger for the first compact muon solenoid (CMS) tracking beam tests is a dedicated system for analog multiplexed front-end electronics. With this first generation of electronics dedicated to CMS tracker detectors, some new specific development was necessary to read it with a multicrate distributed data acquisition (DAQ) system. The goal of this development was to reach a high scalability of experiment subsystems and a good robustness for test beams. Each subsystem had to be independent from the others, both from the hardware and software point of view. Remote control software for this system as well as further monitoring facilities were the required functions of the trigger system 相似文献
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Jaroslawski S. Jeffs M. Matson R. Milborrow R. White D. 《IEEE transactions on nuclear science》1990,37(5):1584-1588
The vertex detector front-end electronics are described. It comprises fast analog-to-digital conversion circuits and a fast programmable track trigger processor. The function of the electronics is to examine, within one large electron-positron beam crossing (22 μs), data generated in the detector for the evidence of charged particle tracks. Measurements of ionization drift times are based on a gated 93-MHz oscillator synchronized to a precision crystal clock and give points in space. The axial positions of these points along the detector are found by analyzing the difference in time of arrivals of signals at the ends of the detector (z by timing). Particle tracks are found by 36 track finders operating in parallel and are matched by semicustom coincidence chips. The track information is used in the first stage of data reduction in the Opal experiments (the first-level trigger) 相似文献
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Yamada S. Hayato Y. Obayashi Y. Shiozawa M. 《IEEE transactions on nuclear science》2008,55(2):683-686
An online system of the underground neutrino detector, Super-Kamiokande is scheduled to be upgraded in 2008 together with front-end electronics. This detector consists of 50 000 tons of pure water equipped with about 13 000 photo-multipliers (PMTs) to detect Cherenkov light. The new online system is required to accept the dataflow of up to 800 MB/s from the front-end electronics and process them for the offline analysis. We will utilize a Gigabit Ethernet network and parallel data processing to handle this large amount of flow. In the new data acquisition scheme, we will not use a hardware event-trigger but read out every hit data from the front-end electronics and process them by the online farm. Therefore, there is no threshold of the number of PMT hits and the detector will become more sensitive to important cosmic-ray events such as relic neutrino from supernova and low energy solar neutrino. In addition to that, a dead-timeless system is desirable for the continuous measurement 365 days a year. In this paper, the detailed design of the upgraded online system and testing activities using prototypes will be described. 相似文献
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微结构气体探测器因其精度高、面积大等优点,在粒子物理实验中得到了非常广泛的应用。微结构气体探测器的未来应用将面临ASIC种类多、通道数多、数据量大等问题,给读出电子学系统的设计带来了很大的挑战,已成为微结构气体探测器进一步发展应用的瓶颈。FELIX系统具有数据带宽大、通道数多等特点,可很好解决这一问题。基于FELIX的电子学系统由完成探测器信号数字化的前端电子学模块、完成数据汇总的GBT模块、完成数据读出的FELIX系统、完成数据处理的数据处理终端组成,可完成10 240路半数字通道读出或4 096路模拟通道读出。该系统与Micromegas探测器一起实现宇宙线径迹探测,验证了该系统的通用性和兼容性,为微结构气体探测器的应用需求提供了一个通用的解决方案。 相似文献
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气体电子倍增器(GEM)电子学板(GEB)在大面积GEM探测器系统中起重要作用。为满足大面积GEM探测器系统中高速电子学信号的传输、实现电磁屏蔽及为前端电子学提供电源等需求,本文设计了8层结构的GEB,并对该GEB原型进行了电气性能、机械兼容性、信号传输和噪声测试。测试结果显示,本文所设计的GEB在320 Mb/s信号传输速度下的误码率小于10-13,在保证信号高速性和完整性的基础上能成功传输前端电子学信号;通过采用叠层对称式设计克服了大面积GEB生产时弯曲程度高的困难,生产的GEB原型弯曲高度降低了2/3,平均弯曲高度为1 mm,增强了前端电子学在探测器系统中的运行稳定性。 相似文献