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991.
Data-extrapolating (extension) technique has important applications in image processing on implicit surfaces and in level set methods. The existing data-extrapolating techniques are inefficient because they are designed without concerning the specialities of the extrapolating equations. Besides, there exists little work on locating the narrow band after data extrapolating—a very important problem in narrow band level set methods. In this paper, we put forward the general Huygens’ principle, and based on the principle we present two efficient data-extrapolating algorithms. The algorithms can easily locate the narrow band in data extrapolating. Furthermore, we propose a prediction–correction version for the data-extrapolating algorithms and the corresponding band locating method for a special case where the direct band locating method is hard to apply. Experiments demonstrate the efficiency of our algorithms and the convenience of the band locating method. 相似文献
992.
Deng Guohe 《高校应用数学学报(英文版)》2007,22(2):127-137
Using Fourier inversion transform, P.D.E. and Feynman-Kac formula, the closedform solution for price on European call option is given in a double exponential jump-diffusion model with two different market structure risks that there exist CIR stochastic volatility of stock return and Vasicek or CIR stochastic interest rate in the market. In the end, the result of the model in the paper is compared with those in other models, including BS model with numerical experiment. These results show that the double exponential jump-diffusion model with CIR-market structure risks is suitable for modelling the real-market changes and very useful. 相似文献
993.
994.
995.
一种基于BTC-PCA的彩色图象压缩方法 总被引:1,自引:0,他引:1
本文提出的彩色图象压缩方法基于BTC(块截断编码)和PCA(主成分分析)的有效结合。先利用PCA方法将图象象素分成二类,简单地实现了矢量量化;然后用BTC方法对分类象素进行简单而高效的编码。实施结果表明此方法简单、易行,效果良好。 相似文献
996.
In this paper we present a nonmonotone trust region method for nonlinear least squares problems with zero-residual and prove its convergence properties. The extensive numerical results are reported which show that the nonmonotone trust region method is generally superior to the usual trust region method. 相似文献
997.
新型的一次性化学离子敏钾、钠测试卡片,是基于离子选择电极(ISE)原理设计制作的一种电化学传感器~[1]。它由测量电池装置、敏感膜、接触衬底(石墨)和盐桥等构件组装而成。采用两点电位测量法。具有一次性使用、简便、快速、精确度高、成本低等优点,对样品不必作预处理,避免了交叉污染,克服了ISE重现性差、固有漂移等缺点,发挥了ISE选择性好、准确度高等优点。根据临床应用和抽样测试结果,钾、钠测试卡片的精密度±SD:钾1.0;钠2.0,C.V%:钾3.0%;钠2.0%;响应时间为30s;漂移:钾0.3mV/min;钠0.5mV/min;回收率为99.5%,均符合临床应用的基本要求。 相似文献
998.
The Lovász Local Lemma is a useful tool in the “probabilistic method” that has found many applications in combinatorics. In this paper, we discuss applications of the Lovász Local Lemma to some combinatorial set systems and arrays, including perfect hash families, separating hash families, ?-free systems, splitting systems, and generalized cover-free families. We obtain improved bounds for some of these set sytems. Also, we compare some of the bounds obtained from the local lemma to those using the basic probabilistic method as well as the well-known “expurgation” method. Finally, we briefly consider a “high probability” variation of the method, wherein a desired object is obtained with high probability in a suitable space. 相似文献
999.
1000.
A novel communication technique is proposed, which utilizes a set ofmutually distinguishable optical pat terns instead of convergent facula to transmit information. Then the capacity is increased by exploiting the optical spatial bandwidth resources. At last, we experimentally demonstrate the proposed communication technique based on four 8 × 8 spatial pattern signals by using lenslet array processor. 相似文献