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排序方式: 共有117条查询结果,搜索用时 203 毫秒
1.
Aidan Mooney John G. Keating Daniel M. Heffernan 《Chaos, solitons, and fractals》2006,30(5):1088-1097
A digital watermark is a visible, or preferably invisible, identification code that is permanently embedded in digital media, to prove owner authentication and provide protection for documents. Given the interest in watermark generation using chaotic functions a detailed study of one chaotic function for this purpose is performed. In this paper, we present an approach for the generation of watermarks using the logistic map. Using this function, in conjunction with seed management, it is possible to generate chaotic sequences that may be used to create highpass or lowpass digital watermarks. In this paper we provide a detailed study on the generation of optically detectable watermarks and we provide some guidelines on successful chaotic watermark generation using the logistic map, and show using a recently published scheme, how care must be taken in the selection of the function seed. 相似文献
2.
Alan Rigter Jan PM Langeveld Drophatie Timmers-Parohi Jorg G Jacobs Peter LJM Moonen Alex Bossers 《BMC biochemistry》2007,8(1):6
Background
The common event in transmissible spongiform encephalopathies (TSEs) or prion diseases is the conversion of host-encoded protease sensitive cellular prion protein (PrPC) into strain dependent isoforms of scrapie associated protease resistant isoform (PrPSc) of prion protein (PrP). These processes are determined by similarities as well as strain dependent variations in the PrP structure. Selective self-interaction between PrP molecules is the most probable basis for initiation of these processes, potentially influenced by chaperone molecules, however the mechanisms behind these processes are far from understood. We previously determined that polymorphisms do not affect initial PrPC to PrPSc binding but rather modulate a subsequent step in the conversion process. Determining possible sites of self-interaction could elucidate which amino acid(s) or amino acid sequences contribute to binding and further conversion into other isoforms. To this end, ovine – and bovine PrP peptide-arrays consisting of 15-mer overlapping peptides were probed with recombinant sheep PrPC fused to maltose binding protein (MBP-PrP). 相似文献3.
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Sarmiento M Mooney P Bishop JM Biswas N Cason NM Dauwe L Godfrey J Kenney VP Pemper R Rojek E Ruchti RC Shephard WD Edelstein RM Forsyth CP Gamarnik K Ginther G Kreymer AE Lipton R McQuade JM Potter DM Russ JS Spiegel L Johnson DE Buchholz D Cremaldi L Delchamps SW Mao HS Rosen JL Sakumoto W Schluter RA Sontz SB Winter C 《Physical review D: Particles and fields》1992,45(7):2244-2248
6.
Summary A new method is proposed for the inclusion of the critical parameter * of some convex operator equationu=Tu (appearing e.g. in thermal explosion theory). It is based on the fact that for a fixed Newton's method starting with a suitable subsolution is not monotonically if and only if >*. Several numerical examples arising from nonlinear boundary value problems illustrate the efficiency of the method. 相似文献
7.
Connor Mooney 《偏微分方程通讯》2019,44(8):681-690
8.
R. L. Barbour J. R. Mooney M. Mehicic R. J. Weinert K. C. Benton J. G. Grasselli 《Macromolecular Symposia》1986,5(1):49-59
Polymer coatings on steel substrates were analyzed by reflectance/absorbance infrared spectroscopy. Initial studies were performed ex-situ on samples which had been cured at a variety of temperatures on two different substrates. Further studies were done in-situ under both air and nitrogen atmospheres. The two substrates studied were untreated cold-rolled steel and cold-rolled steel with a conversion coating of zinc phosphate. Changes in the spectra of the phosphate conversion layer correlated well with anti-corrosion properties. Mechanisms of degradation and cure could be determined from the in-situ studies (1). 相似文献
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Eastman DE Stagarescu CB Xu G Mooney PM Jordan-Sweet JL Lai B Cai Z 《Physical review letters》2002,88(15):156101
Columnar microstructure in step-graded Si(1-x)Ge(x)/Si(001) structures with low threading dislocation densities has been determined using high angular resolution (approximately 0.005 degrees ) x-ray microdiffraction. X-ray rocking curves of a 3-microm-thick strain-relaxed Si(0.83)Ge(0.17) film show many sharp peaks and can be simulated with a model having a set of Gaussians having narrow angular widths (0.013 degrees -0.02 degrees ) and local ranges of tilt angles varying from 0.05 degrees to 0.2 degrees. These peaks correspond to individual tilted rectangular columnar micrograins having similar (001) lattice spacings and average areas of 0.8 to 2.0 microm(2). 相似文献