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排序方式: 共有1382条查询结果,搜索用时 15 毫秒
11.
《国际计算机数学杂志》2012,89(2):222-238
In this paper, for an integer n≥10, two classes of n-variable Boolean functions with optimum algebraic immunity (AI) are constructed, and their nonlinearities are also determined. Based on non-degenerate linear transforms to the proposed functions, we can obtain 1-resilient n-variable Boolean functions with optimum AI and high nonlinearity if n?1 is never equal to any power of 2. 相似文献
12.
基于优秀基因传播的免疫优化算法 总被引:2,自引:0,他引:2
对文献[5]的工作进行改进,改进基因重组策略,增加免疫基因传播操作,使得算法能够更快更好的搜索最优解.核心思想是区分成熟抗体中高层次抗体和低层次抗体,低层次群体不断更新,高层次群体相对稳定,但不断从低层次群体中学习优秀基因完善自身.本文详细介绍了该算法的设计思想和具体实验,实验结果说明本算法具有较好的问题求解能力. 相似文献
13.
A particle swarm optimization (PSO) algorithm improved by immunity algorithm (IA) was presented. Memory and self-regulation
mechanisms of IA were used to avoid PSO plunging into local optima. Vaccination and immune selection mechanisms were used
to prevent the undulate phenomenon during the evolutionary process. The algorithm was introduced through an application in
the direct maintenance cost (DMC) estimation of aircraft components. Experiments results show that the algorithm can compute
simply and run quickly. It resolves the combinatorial optimization problem of component DMC estimation with simple and available
parameters. And it has higher accuracy than individual methods, such as PLS, BP and v-SVM, and also has better performance
than other combined methods, such as basic PSO and BP neural network. 相似文献
14.
Shcherbakov G. N. Antselevich M. A. Udintsev D. N. Filin V. G. 《Measurement Techniques》2005,48(7):707-710
Practical ways of increasing the noise immunity and safety of magnetometer scanning instruments are considered. Versions of
such instruments in the form of a prototype of a portable magnetometer scanning instrument for detecting secretly carried
ferromagnetic objects under unfavorable interference conditions are presented.
__________
Translated from Izmeritel'naya Tekhnika, No. 7, pp. 53–55, July, 2005. 相似文献
16.
在仿射等价的意义下,变元可分离布尔函数f可以表示为变元互不相同的两个布尔函数g和h的和。文章研究了这类函数与其补函数的零化子的最低次数关系,结论表明,通过计算g和h的代数免疫度,可以确定f及其补函数的零化子的最低次数的大小关系并得到f的代数免疫度的上界。由于g和h的变元个数小于f的变元个数,上述结论使得计算f的代数免疫度的复杂度大大降低。最后,针对一类特殊的非变元可分离布尔函数讨论了该函数与其补函数的零化子的最低次数关系。 相似文献
17.
考虑分数阶微分对信号处理的性质与特点,提出一种基于分数阶微分的信息提取算法。首先针对各种系数高斯噪声的图像进行信息提取,并与Roberts、Prewitt、Sobel整数阶经典算子对图像信息提取的结果进行分析比较。实验证明,利用分数阶微分不但能提取整数阶算子的高频边缘信息,还能提取平滑区域的纹理信息,并对高斯噪声具有一定程度的抗噪性。 相似文献
18.
传统粒子群优化算法在解决组合优化问题上具有一定的局限性,通过分析其优化机理,对迭代公式加以改进,提出了改进微粒群算法。算法中,利用遗传算法的交叉思想来完成粒子间的信息交换,以期达到粒子更新。粒子进化过程中,为保留群体中的优秀粒子,使用了加速度这一优化算子。为避免粒子陷入局部搜索,迭代过程中使用免疫算法来动态评价微粒群体。通过大量实验仿真,算法可以有效求解作业车间调度问题,验证了算法的合理性。 相似文献
19.
Oliver Shey-Njila Ahmed F. Hikal Tuhina Gupta Kaori Sakamoto Hind Yahyaoui Azami Wendy T. Watford Frederick D. Quinn Russell K. Karls 《International journal of molecular sciences》2022,23(10)
Copper is required for aerobic respiration by Mycobacterium tuberculosis and its human host, but this essential element is toxic in abundance. Copper nutritional immunity refers to host processes that modulate levels of free copper to alternately starve and intoxicate invading microbes. Bacteria engulfed by macrophages are initially contained within copper-limited phagosomes, which fuse with ATP7A vesicles that pump in toxic levels of copper. In this report, we examine how CtpB, a P-type ATPase in M. tuberculosis, aids in response to nutritional immunity. In vitro, the induced expression of ctpB in copper-replete medium inhibited mycobacterial growth, while deletion of the gene impaired growth only in copper-starved medium and within copper-limited host cells, suggesting a role for CtpB in copper acquisition or export to the copper-dependent respiration supercomplex. Unexpectedly, the absence of ctpB resulted in hypervirulence in the DBA/2 mouse infection model. As ctpB null strains exhibit diminished growth only in copper-starved conditions, reduced copper transport may have enabled the mutant to acquire a “Goldilocks” amount of the metal during transit through copper-intoxicating environments within this model system. This work reveals CtpB as a component of the M. tuberculosis toolkit to counter host nutritional immunity and underscores the importance of elucidating copper-uptake mechanisms in pathogenic mycobacteria. 相似文献
20.
Joanna Jeruzal-
witecka Edyta Borkowska Mateusz aszczych Zuzanna Nowicka Wioletta Pietruszewska 《International journal of molecular sciences》2022,23(13)
Studies have shown differences in TAS2R38 receptor expression in patients with chronic rhinosinusitis (CRS) compared to healthy controls. Known agonists of TAS2R38 stimulate epithelial cells, leading to robust intracellular nitric oxide (NO) production, which damages bacterial membranes, enzymes, and DNA, but also increases ciliary beat frequency. In this study we examined, using qRT-PCR, the expression of TAS2R38 receptor in nasal polyps (NP) of patients with CRS (N = 107) and in inferior turbinate mucosa (ITM) of patients with CRS and controls (N = 39), and confronted it with clinical features and the severity of the disease. The expression was shown in 43 (50.00%) samples of ITM in the study group (N = 107), in 28 (71.79%) in the control group (N = 39) (p = 0.037), and in 43 (46.24%) of NP. There were no differences in levels of the expression in all analyzed tissues. Patients who rated their symptoms at 0–3 showed higher TAS2R38 expression in ITM in comparison to the patients with 8–10 points on the VAS scale (p = 0.020). A noticeable, however not significant, correlation between the TAS2R38 expression in ITM and the Lund–Mackay CT score was shown (p = 0.068; R = −0.28). Patients with coexisting asthma had significantly higher receptor expression in the NP (p = 0.012). Our study is the first to confirm the presence of the TAS2R38 receptor in NP. Expression of the TAS2R38 receptor is reduced in the sinonasal mucosa in patients with more advanced CRS with NP. 相似文献