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1.
Reducible rank codes and their applications to cryptography 总被引:2,自引:0,他引:2
Gabidulin E.M. Ourivski A.V. Honary B. Ammar B. 《IEEE transactions on information theory / Professional Technical Group on Information Theory》2003,49(12):3289-3293
We present a new family of so-called reducible rank codes which are a generalization of rank product codes . This family includes maximal rank distance (MRD) codes for lengths n>N in the field F/sub N/. We give methods for encoding and decoding reducible rank codes. A public key cryptosystem based on these codes and on the idea of a column scrambler is proposed. The column scrambler "mixes" columns of a generator (parity-check) matrix of a code. It makes the system more resistant to structural attacks such as Gibson's attacks. Possible attacks on the system are thoroughly studied. The system is found to be secure against known attacks for public keys of about 16 kbits and greater. 相似文献
2.
In this article, we apply the renormalization technique, used possibly in theorical physics, for electromagnetic studying of bi dimensional fractal structures. A recurrence relation based on the auto-similar nature of structures and on the model of the surface impedance, has permitted, thanks to the convergence to a fixed point, to determine the input impedance of these structures at any scale. Though, the suggested method has been validated by calculus of one-dimensional structures (Iris de Cantor) it may be applied easily to the analysis of planar circuits as the Sierpensky antenna. 相似文献
3.
4.
Ammar Moulahi 《Comptes Rendus Mathematique》2006,342(11):853-858
We consider the stabilization of Maxwell equations in two dimensional on the exterior of an arbitrary bounded obstacle. Using some results concerning of wave equations with Neumann boundary condition in the exterior domain. We deduce under the ‘exterior geometric control condition’ the behavior of the solution for large time. To cite this article: A. Moulahi, C. R. Acad. Sci. Paris, Ser. I 342 (2006). 相似文献
5.
Ammar R Ball RC Banerjee S Bhat PC Bosetti P Bromberg C Canough GE Coffin T Dershem TO Dixon RL Fenker HC Ganguli SN Gensch U Girtler P Goshaw AT Grard F Gurtu A Hamilton C Henri VP Hernandez JJ Hrubec J Iori M Jones LW Kuhn D Knauss D Leedom ID Legros P Lemonne J Leutz H Liu X Malhotra PK Marraffino JM Mendez GE Miller R Naumann T Nguyen A Nowak H Pilette P Poirier J Poppleton A Raghavan R Rasner K Reucroft S Robertson WJ Roe BP Roth A Senko M Struczinski W Subramanian A Touboul MC Vonck B 《Physical review letters》1988,61(19):2185-2188
6.
Ammar Mustafa N. M. Mikhailova N. S. Prostakov 《Chemistry of Heterocyclic Compounds》1996,32(1):65-67
9-Phenacylidene-4-azaf luorene and 9-bromo-9-(-bromophenacyl)-4-azafluorene have been used in the synthesis of spiro compounds with fragments of substituted pyrazolines. 1-Methyl-2-oxo-5 phenacylidene-indeno[2, 3-e]-1,2-dihydropyridine and hydrazine gave 1-methyl-2-oxo-3 phenylspiro[indeno(2, 3-e)-1,2-dihydropyridine-5,5-pyrazoline-2]. 相似文献
7.
Albrecht H Binder U Harder G Lembke-Koppitz I Philipp A Schmidt-Parzefall W Schröder H Schulz HD Wurth R Donker JP Drescher A Matthiesen U Scheck H Spaan B Spengler J Wegener aD Gabriel JC Schubert KR Stiewe J Waldi R Weseler S Brown NN Edwards KW Frisken WR Fukunaga C Gilkinson DJ Gingrich DM Goddard M Kapitza H Kim PC Kutschke R MacFarlane DB McKenna JA McLean KW Nilsson AW Orr RS Padley P Patel PM Prentice JD Seywerd HC Stacey BJ Yoon T Yun JC Ammar R Coppage D Davis R Kanekal S Kwak N 《Physical review letters》1986,56(6):549-552
8.
L. Poul S. Ammar N. Jouini F. Fievet F. Villain 《Journal of Sol-Gel Science and Technology》2003,26(1-3):261-265
A new route for the preparation of powdery metal, oxide and hydroxide materials is presented as a chimie douce alternative to the sol-gel method. It consists in the reduction or the hydrolysis of a metal salt dissolved and heated in a polyol medium. It appears through zinc and cobalt examples that the use of acetate precursors contrarily to chloride or sulfate ones leads to the precipitation of a solid (metal, oxide, hydroxide) whose nature depends on two main factors: the hydrolysis ratio, defined by the water to metal molar ratio, and the reaction temperature. As in the sol-gel method, acetate leads to the formation of intermediate alkoxyacetate complex. The absence of water favors metal formation while its presence favors oxide or hydroxyacetate formation. 相似文献
9.
M. E. Kassem A. M. El-Khatib E. A. Ammar M. M. Denton 《Journal of Thermal Analysis and Calorimetry》1991,37(3):533-540
Thermodynamic studies of (LixK1?x)2SO4, LKS, mixed crystals have been made in the concentration range (x=0.1, 0.2, ...,x=0.5). The thermal behaviour has been investigated by differential thermal analysis, DTA, and differential scanning calorimeter, DSC, in the vicinity of high temperature phases. Also, the effect of the thermal neutron irradiations on the thermal properties of mixed crystals was studied. The results showed a change in the transition temperatureT c, as well as the value of specific heatC p at transition temperature, due to the change of stoichiometric ratio and radiation doses. The change of enthalpy and entropy of mixed crystals have been estimated numerically. 相似文献
10.
Solid-state kinetics was developed from kinetic concepts for reactions in homogeneous phase systems, which has created considerable debate over issues such as variable activation energy. This behavior has been viewed by some as a violation of basic chemical kinetic principles. Variation in activation energy has been detected by isoconversional or ‘model-free’ calculation methods. The relationship between different calculation methods and the occurrence of variable activation energy was investigated in this work by employing model-fitting and isoconversional methods to analyze simulated isothermal data. In addition, these approaches were applied for sulfameter-dioxolane solvate desolvation data. We showed that variable activation energy is of two types—a true variation that results from the complex nature of the solid-state process and an artifactual one resulting from the use of some isoconversional methods. 相似文献