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《电子科技文摘》2006,(9)
0623592 DS-CDMA系统窄带干扰的去除技术[刊,中]/叶奕亮//电讯技术.—2006,46(3).—156-158(G) 0623593用椭圆曲线密码体制实现CDMA通信的鉴权[刊,中]/姜晓梅//信息安全与通信保密.—2006,(1).—86-88(L)本文简要分析了CDMA通信系统安全需求,在阐述椭圆曲线密码体制的优点及在无线通信中应用优势的基础上,提出了椭圆曲线密码体制在CDMA通信系统中鉴权的一种实现方案。参6 0623594 OFDM系统的自适应符合同步算法[刊,中]/王顶//信息安全与通信保密.—2006,(1).—77-79(L)本文提出了一种在OFDM系统中基于导频符号的自适应符号同步新算法,它利用FFT的特性,采用频域同步方法,对符号定时进行估计。该算法计算量小,插入的导频数少,并且同步捕获速度、精度高低,可以灵活调节。仿真结果表明,该算法能简单而有效地获取符号同步,自适应性强。参5 相似文献
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椭圆曲线密码体制已经成为密码学的研究热点之一.相对于其它公钥密码体制,椭圆曲线密码体制有短密钥和计算效率高等优点.本文介绍椭圆曲线密码体制及其在加密和数字签名等方面的应用,并讨论了椭圆曲线密码体制的安全性. 相似文献
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椭圆曲线密码体制的研究 总被引:2,自引:1,他引:1
椭圆曲线密码体制(ECC)是利用椭圆曲线点群上的离散对数问题的难解性而提出的一种公开密钥算法,文章以ECC为研究对象,从数据加密角度研究了椭圆曲线密码体制,对椭圆曲线密码体制进行了详细的讨论,并总结了椭圆曲线体制在几个方向的应用。 相似文献
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ECC密码技术及其优越性 总被引:7,自引:0,他引:7
椭圆曲线密码体制是近年来兴起的一种性能优良的公钥密码体制,本文介绍了椭圆曲线密码体制的有关概念和基本理论,将它与其它公钥密码体制进行了比较,阐述了椭圆曲线密码体制的优越性。 相似文献
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文中利用椭圆曲线密码体制密钥短,安全性高的特点,并运用小波分析技术,将加密通信和信息隐藏相结合,提出基于椭圆曲线密码体制与小波分析的秘密信息隐藏方案。文中对方案各部分进行了详细介绍,并给出信息隐藏的效果图。 相似文献
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文中介绍了SET协议的运作方式,对超椭圆曲线密码体制和RSA密码体制作了比较,提出了在SET协议中使用基于超椭圆曲线密码体制的的数字签名和数字信封方案,提升了SET协议的安全性和运算速度。 相似文献
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椭圆曲线密码体制已成为公钥密码研究的主流。介绍了椭圆曲线密码体制的一些数学理论基础,对算法的基础模块进行了说明,讨论了软件实现素数域上椭圆曲线密码算法的一种方法,在DSP6205,主频200MHz的环境下,192比特的ECDSA签名速率70次/秒,验证速率60次/秒。最后对椭圆曲线加密体制的研究与实现进行了全面总结,给出了所完成的工作,对椭圆曲线密码体制的应用前景提出了展望。 相似文献
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V. S. Vlasov L. N. Kotov V. G. Shavrov V. I. Shcheglov 《Journal of Communications Technology and Electronics》2011,56(1):73-84
Forced nonlinear precession of the magnetization vector in a normally magnetized magnetic plate under the conditions of an
orientation transition is considered. It is shown that, in the field lower than the form demagnetization field, the variable
circularly polarized field causes precession of the equilibrium position of the magnetization vector. It is demonstrated based
on a vector model in which the precession period of the equilibrium position is inversely proportional to the squared amplitude
of the variable field and the sine of the angle of deviation of the equilibrium position of magnetization from the constant
field. It is shown that the critical parameters necessary for excitation of precession of the equilibrium position are the
amplitude and frequency of the variable field. Diagrams determining domains of existence of precession of the equilibrium
position for different saturation magnetization of a magnetic plate are constructed in terms of the coordinates variable field
amplitude-frequency. The role of dissipation of magnetization oscillations in the determination of the critical parameters
is elucidated. The features of precession in the presence of asymmetric excitation and in the presence of anisotropy in the
plane of the plate are noted. 相似文献
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多光子Tavis-Cummings模型中运动原子与二项式光场相互作用的量子纠缠 总被引:2,自引:2,他引:0
利用全量子理论,研究了多光子Tavis-Cummings模型中运动原子与二项式光场相互作用系统的量子纠缠特性,讨论了不同初始状态下的二项式光场系数和原子运动速度对纠缠特性的影响.结果表明:二项式光场系数不影响场熵演化的周期性,但影响场熵峰值大小.随着原子跃迁光子数的增多,场熵演化的周期性和消纠缠现象逐渐消失.原子运动的速度影响场熵的演化周期,且影响场熵峰值的大小,而原子跃迁光子数的增大,会消弱原子运动速度对场熵演化的影响.当光场处于中间态,原子运动速度较低,且原子跃迁光子数较大时,光场与原子可以长久地处于量子纠缠态. 相似文献
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有线电视加解密系统研究 总被引:2,自引:0,他引:2
有线电视加解密技术是有线电视付费管理的一个重要技术保障。在发射端,先将各路电视视频信号进行同步时基校准后,根据同步图案数据确定的同步图案实现每一路电视信号的同步信号的时基处理,以完成电视信号加密(加扰),随后将各路加密(加扰)电视信号连同数据的调制信号一起发送。在接收端,先根据射频信号解调出同步图案数据,并根据解调出的同步图案数据对射频信号进行群解密(解扰),从而实现了电视信号的单加群解。 相似文献
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M. Kukacka 《e & i Elektrotechnik und Informationstechnik》2000,117(3):223-226
One essential component of project planning of train control system plants is the design and calculation of the protective route. At first, definitions of the most important terms are explained. There are three different calculation methods depending on the regard of the slope of the track system as well as on the train mass representable. The simplest method only considers the maximum slope before the signal and the danger point. The second method considers the slope of the track in the form of stairs. The gradient method is presented as a third method. The regard of the inclination gradient occurs here in the form of a twofold averaging. On the one hand the mean value in the form of an integral is formed via the train length. On the other hand averaging occurs in the form of an integral via the braking distance. The middle inclination value found in this way is inserted in the iterative process for the determination of the protective route. 相似文献
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结合红外辐射理论分别建立了控制柜内部单个和多个元件同时过热时对壳体内表面的红外辐射模型,得到了壳体内表面总的热流密度分布,并针对受热壳体建立二维热传导模型。基于对壳体表面红外成像测温,运用L-M算法进行了导热反问题模拟研究,对控制柜内部单个和多个元件的发热温度和方位进行了识别,最后分析了测量误差对计算结果的影响。结果发现运用L-M算法对单个和多个故障元件的发热温度和方位进行分开反演求解和同时进行反演计算时,都取得了较好效果,求解精度较高。测量误差对发热温度的反演计算结果影响更大。 相似文献
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分析了激光功率密度增加到原来的10倍的时候,激光干扰行间转移CCD的串扰图像部分的灰度值并不是成比例地增加,并对串扰图像进行了仿真。由于光电二极管的溢出是不断进行的,垂直CCD的每个像元都获得所有超过阈值的像元溢出的光生载流子之和。每个超过阈值的像元溢出的光生载流子等于垂直CCD向下移动一个像元所需的时间内溢出的光生载流子。通过求解感光部分中光生电子遵守的方程,得到电子浓度增量和入射光功率的关系,进而仿真出串扰图像。仿真了激光能量为串扰阈值10倍和100倍量级时的串扰图像,仿真结果和实验结果可比。 相似文献
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V. A. Balagurovskiy A. S. Kondratiev A. O. Manichev N. P. Polishchuk 《Journal of Communications Technology and Electronics》2017,62(6):549-557
Two approaches to the phase-only synthesis of nulls in radiation patterns (RPs) of the phased array antenna (PAA) of a coordinate meter are considered. The approaches use the specificity of the structure of the sheet of the measuring PAA. Such a PAA forms the sum RP and two difference RPs, which ensure measuring of the angular coordinates of an object. The problem of the phase-only synthesis of pattern nulls in prescribed directions in one or several PAA RPs with the angular orientation of the nulls of difference RPs kept in the RP scanning direction is solved. Design relationships are derived and a RP synthesis method, which is based on iterative univariate minimization of a nonlinear functional and includes analytic determination of the minimum of this functional at each iteration, is described. Examples of the array pattern synthesis are presented. The effect the phasing increment on the depth of formed nulls is analyzed and the dependence of the value of the PAA RP in the scanning direction on the position of the formed null is investigated. The effect of synthesized nulls on the shape of the PAA direction-finding characteristic is analyzed. 相似文献
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A two-layer stratified model is assumed for the earth. The distances involved are assumed to be sufficiently short that the earth can be considered flat. The measurement of the parameters of the top layer can easily be made from the surface, but the parameters of the lower layer are somewhat more difficult. A method is given for the evaluation of these quantifies in terms of measurements of propagation between two antennas located at the surface of the earth. The theoretical solution for the field of an antenna located at the surface of a flat stratified earth has been given by J. R. Wait. This solution is taken as the starting point; it is put into a form which explicitly shows the influence of the parameters of the lower layer. The method of least squares is then used to evaluate the unknown parameters in terms of the measurements. This process allows the use of a large number of measurements which are essentially subjected to an averaging procedure. This prevents localized irregularities in the earth's surface from unduly affecting the results. 相似文献