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排序方式: 共有911条查询结果,搜索用时 15 毫秒
11.
Boris Ryabko Zhanna Reznikova Alexey Druzyaka Sofia Panteleeva 《Theory of Computing Systems》2013,52(1):133-147
Kolmogorov complexity furnishes many useful tools for studying different natural processes that can be expressed using sequences of symbols from a finite alphabet (texts), such as genetic texts, literary and music texts, animal communications, etc. Although Kolmogorov complexity is not algorithmically computable, in a certain sense it can be estimated by means of data compressors. Here we suggest a method of analysis of sequences based on ideas of Kolmogorov complexity and mathematical statistics, and apply this method to biological (ethological) ??texts.?? A distinction of the suggested method from other approaches to the analysis of sequential data by means of Kolmogorov complexity is that it belongs to the framework of mathematical statistics, more specifically, that of hypothesis testing. This makes it a promising candidate for being included in the toolbox of standard biological methods of analysis of different natural texts, from DNA sequences to animal behavioural patterns (ethological ??texts??). Two examples of analysis of ethological texts are considered in this paper. Theses examples show that the proposed method is a useful tool for distinguishing between stereotyped and flexible behaviours, which is important for behavioural and evolutionary studies. 相似文献
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Alexey Glutsyuk 《Journal of Dynamical and Control Systems》2014,20(3):293-306
The famous conjecture of V. Ya. Ivrii (1978) says that in every billiard with infinitely-smooth boundary in a Euclidean space the set of periodic orbits has measure zero. In the present paper, we study the complex version of Ivrii’s conjecture for odd-periodic orbits in planar billiards, with reflections from complex analytic curves. We prove positive answer in the following cases: (1) triangular orbits; (2) odd-periodic orbits in the case, when the mirrors are algebraic curves avoiding two special points at infinity, the so-called isotropic points. We provide immediate applications to k-reflective real analytic pseudo-billiards with odd k, the real piecewise-algebraic Ivrii’s conjecture and its analogue in the invisibility theory: Plakhov’s invisibility conjecture. 相似文献
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Alexey Komkov Rostislav Kamkin 《JOM Journal of the Minerals, Metals and Materials Society》2011,63(1):73-76
A thermodynamic mathematical model, describing behavior of Pb, Zn, and As during reducing slag cleaning in the Vanyukov furnace
has been developed. Using a developed model, the influence of different factors, such as temperature, oxygen partial pressure,
the ratio of the formed phases on the behavior of impurities, was analyzed. It was found that arsenic can significantly move
to the bottom phase, and zinc can be significantly vaporized under conditions in the Vanyukov furnace. 相似文献
16.
Effect of silicon content in steel and oxidation temperature on scale growth and morphology 总被引:1,自引:0,他引:1
Amine Alaoui Mouayd Alexey Koltsov Eliane Sutter Bernard Tribollet 《Materials Chemistry and Physics》2014
The effect of high silicon content in steel, 1.6 wt.%Si and 3.2 wt.%Si, and high oxidation temperatures (850–1200 °C) on scale growth rate and morphology were investigated. The steels were oxidized in a 15% humid air with short isothermal oxidation times (15 min). The scale growth rate of the non-alloyed steel follows a parabolic law with time; it is an iron diffusion controlled oxidation. The presence of silicon delays scale growth by forming a silica SiO2 barrier layer at the scale/metal interface, this effect is more important for the steel containing 3.2 wt.%Si and induces a discontinuous scale. Silicon oxides are concentrated at the scale/metal interface; their morphology depends on the oxidation temperature. For temperatures lower than 950 °C, silica is formed. Between 950 °C and 1150 °C, fayalite (Fe2SiO4) grains appear in the wüstite matrix close to the scale/metal interface. For temperatures higher than 1177 °C, a fayalite–wüstite eutectic is formed; this molten phase favours iron diffusion leading to high scale growth. After cooling, a continuous fayalite layer with small wüstite grains is obtained at the scale/steel interface. 相似文献
17.
Alexey A. Roenko Vladimir V. Lukin Igor Djurović Xu Zhengguang 《Signal, Image and Video Processing》2009,3(2):157-170
A novel adaptive clipping technique for filtering a constant amplitude frequency modulated (FM) signal embedded in non-Gaussian
noise is proposed. It is based on the analysis and processing of the estimate of probability density function of a FM signal
realization. As a result, modifications of two robust estimators of FM signal amplitude are proposed. It is shown that these
estimators can be used for Gaussian and non-Gaussian heavy-tail environments. The proposed clipping technique can exploit
one or another obtained robust estimate of the signal amplitude for adaptive setting a threshold. Analysis of signal estimate
accuracy for different noise environments is carried out. Comparative analysis of the obtained methods and known approaches
based on scanning window nonlinear filtering and optimal robust L-DFT form is performed. It is demonstrated that the usage
of clipping-based technique leads to the considerable improvement of the FM signal filtering efficiency in comparison to the
aforementioned known approaches for different noise environments and a wide range of input SNR values. 相似文献
18.
Studying of cellular interaction of hairpin‐like peptide EcAMP1 from barnyard grass (Echinochloa crusgalli L.) seeds with plant pathogenic fungus Fusarium solani using microscopy techniques 下载免费PDF全文
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Karen S. Torosyan Alexey S. Sedegov Kirill V. Kuskov Mohammad Abedi Dmitry I. Arkhipov Philipp V. Kiryukhantsev-Korneev Stepan Vorotilo Dmitry O. Moskovskikh Alexander S. Mukasyan 《Journal of the American Ceramic Society》2020,103(1):520-530
The influence of different SPS-based methods, that is, conventional spark plasma sintering (SPS), flash SPS (FSPS), and reactive SPS (RSPS) on the properties of Al2O3/SiC composite was investigated. It was shown that the application of preliminary high energy ball milling of the powders significantly enhances the sinterability of the ceramics. It was also demonstrated that FSPS provides unique conditions for rapid, that is, less than a minute, consolidation of refractory ceramics. The Al2O3-20 wt% SiC composite produced by FSPS possesses the highest relative density (~99%), fracture toughness (7.5 MPa m1/2), hardness (20.3 GPa) and wear resistance among all ceramics produced by other SPS-based approaches with dwelling time 10 minutes. The RSPS ceramics hold the highest Young's modulus (390 GPa). Substitution of micron-sized Al2O3 particles by nano alumina does not lead to measurable enhancement of the mechanical properties. 相似文献