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971.
Lattice-based cryptosystems rely on certain lattice problems for their security, such as the shortest vector and the closest vector problems. NTRU is a kind of lattice-based public key cryptosysytem gaining much attention because of its high efficiency. Its encryption and decryption use a mixing system suggested by polynomial algebra combined with a clustering principle based on elementary probability theory. With the availability of quantum computers, the security of cryptosystems based on classical mathematic problems needs to be reevaluated. Since lattice reduction is the main threat to lattice-based cryptosystems, lattice reduction using quantum search algorithms are analyzed to evaluate the security of NTRU in this paper. According to our results, original security parameters proposed for NTRU should be increased in the event that Grover's quantum search algorithm is used for lattice reduction. 相似文献
972.
Zhigang Zeng Jun Wang Xiaoxin Liao 《IEEE transactions on circuits and systems. I, Regular papers》2004,51(11):2313-2324
We show that any N/spl times/M-dimensional delayed cellular neural network described using cloning templates can have no more than 3/sup N/spl times/M/ isolated equilibrium points and 2/sup N/spl times/M/ of these equilibrium points located in saturation regions are locally exponentially stable. In addition, we give the conditions for the equilibrium points to be locally exponentially stable when the equilibrium points locate the designated saturation region. These conditions improve and extend the existing stability results in the literature. The conditions are also very easy to be verified and can be checked by direct examination of the templates, regardless of the number of cells. Finally, the validity and performance of the results are illustrated by use of two numerical examples. 相似文献
973.
In this paper, a new hydrogenation process of poly-Si thin film for the fabrication of poly-Si thin film transistors (TFTs) is proposed. In the new approach, the hydrogenation of TFTs is performed before deposition of contact metal. N-channel and p-channel poly-Si TFTs with various channel lengths and widths were fabricated with the new and conventional processes for comparison. The results verified that the efficiency of hydrogenation has been improved remarkably by the new process. The field-effect mobility of carriers, the on state current, threshold voltage and the on/off states current ratio have been greatly improved, and the trap state density has been reduced significantly. 相似文献
974.
Haibing Li Yuanyin Chen Zhaorui Zeng Chuanhui Xie Xiangliang Yang 《Analytical sciences》2005,21(6):717-720
The preparation and characterization of p-tert-butylcalix[4]arene-1,3-bis(allyloxyethoxy)ether (CA[4]-BAE) chemically coated capillaries via a free-radical reaction with vinyltriethoxysilane (VTES) that was attached onto the inner wall previously were carried out. IR spectra and decreased electroosmotic flow (EOF) suggested that the capillary was successfully coated with CA[4]-BAE. A slight slope of EOF versus pH at 5 < pH < 9 would help to make the separation reproducible. The CA[4]-BAE-coated capillary showed improved separations of toluidine isomers, naphthol isomers and polycyclic aromatic hydrocarbons (PAHs) compared with an uncoated capillary. The special selectivity indicates that there is a certain extent of host-guest interactions between the solutes and the CA[4]-BAE coating. 相似文献
975.
XiaoFang Zhu ZhongHai Yang BaoQing Zeng 《Journal of Infrared, Millimeter and Terahertz Waves》2004,25(5):837-843
Recent development of MEMS technologies has provided a set of methods for mass production of three-dimensional micro-scale structures and have opened the door to new and exciting possibilities in vacuum electronics devices. These micro-fabricated vacuum electronic devices are popular for the advantages of small volume, low cost, good performance, etc. In this article, Cold characteristics of a miniature coupled cavity slow-wave structure are simulated and discussed by using 3-D electromagnetic software MAFIA. The results show that this miniature structure can work at near 1.3 THz with high interaction impedance about 20 ohm and can be expected to be a promising THz radiation source. 相似文献
976.
硬质合金激光铣削加工试验研究 总被引:3,自引:0,他引:3
采用不同的激光铣削工艺对硬质合金进行激光铣削试验研究。分析了工艺参数对铣削量和铣削质量的影响,并利用优化或复合的工艺对硬质合金试样进行多样激光铣削。 相似文献
977.
云南甘草中齐墩果烷型五环三萜化合物的NMR谱的研究 总被引:2,自引:1,他引:1
本文研究了云南甘草皂甙元(glyyunnansapogenin)等oleanane类化合物的核磁共振谱。运用PBB,INEPT,DEPT方法,并结合化学位移值规律归属了这些化合物的13C-NMR信号。总结出用角甲基的化学位移植范围判定角甲基的取代位置的方法,分析了角甲基被氧取代后对环的化学位移值的影响。按类似olean-12-en,18α-H方式考虑,归属了oleana-11,13(18)-diene化合物的13C-NMR信号。讨论了具30→18β内酯或2929→18α内酯类化合物的核磁谱规律。另外,还发现了DE环上有1个OAC取代时,与其偕碳质子的化学位移值规律。 相似文献
978.
979.
In this paper, an additive Schwarz algorithm is considered for solving the finite-dimensional nonlinear complementarity problem with M-function. The monotone convergence of the algorithm is obtained with special choices of initial values. Moreover, the weighted max-norm bound is obtained for the iterative errors. 相似文献
980.
This paper discussed the matrix equation AXB+CYD=Eover a simple Artinian ring, obtains several necessary and sufficient conditions for existence of a solution, gives the representation of solution by g-inverses, and extends a theorem of W.E. Roth's simple Artinian rings. 相似文献