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We propose a method for estimating the amplitude of measurement noise present in chaotic time series. This method is based on the evaluation of initial errors for a given time series and for a new one synthesized by adding an adequate amount of noise to the given one. The method is valid over a much wider range of noise levels than the previous methods are because it is not based on the detail of dynamical structure which generates the data. In addition, it is possible to check if the method is valid for the given data prior to its application. To confirm the effectiveness of the method we show the results of numerical experiments and apply the method to chaotic data obtained from an electrochemical experiment. (c) 1999 American Institute of Physics. 相似文献
34.
Anek Charoenphakdee Ken Kurosaki Hiroaki Muta Masayoshi Uno Shinsuke Yamanaka 《固体物理学:研究快报》2008,2(2):65-67
High‐density polycrystalline samples (above 98% of the theoretical density) of Ag8GeTe6 were prepared by solid‐state reactions of Ag2Te, GeTe, and Te, followed by hot‐pressing. The thermoelectric properties were measured at temperatures ranging from room temperature to around 700 K. The thermal conductivity values were extremely low (0.25 Wm–1 K–1 at room temperature), and consequently Ag8GeTe6 exhibited a relatively high thermoelectric figure of merit, ZT = 0.48 at 703 K. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
35.
Haobing Wang Xia Wu Yang Yang Masayoshi Nishiura Zhaomin Hou 《Angewandte Chemie (International ed. in English)》2020,59(18):7173-7177
The precise control of monomer sequence and stereochemistry in copolymerization is of much interest and importance for the synthesis of functional polymers, but studies toward this goal have met with only limited success to date. Now, the co‐syndiospecific alternating copolymerization of methoxyphenyl‐ and N,N‐dimethylaminophenyl‐functionalized propylenes with styrene by half‐sandwich rare‐earth catalysts is reported. This reaction efficiently afforded the corresponding functionalized propylene‐alt‐styrene copolymers with a perfect alternating sequence and excellent co‐syndiotacticity (rrrr >99 %), thus constituting the first example of co‐stereospecific alternating copolymerization of polar and non‐polar olefins. 相似文献
36.
Takanori Ide Hiroshi Isozaki Susumu Nakata Samuli Siltanen Gunther Uhlmann 《纯数学与应用数学通讯》2007,60(10):1415-1442
Let a physical body Ω in ?2 or ?3 be given. Assume that the electric conductivity distribution inside Ω consists of conductive inclusions in a known smooth background. Further, assume that a subset Γ ? ?Ω is available for boundary measurements. It is proved using hyperbolic geometry that certain information about the location of the inclusions can be exactly recovered from static electric measurements on Γ. More precisely: given a ball B with center outside the convex hull of Ω and satisfying (B? ∩ ?Ω) ? Γ, boundary measurements on Γ with explicitly given Dirichlet data are enough to determine whether B intersects the inclusion. An approximate detection algorithm is introduced based on the theory. Numerical experiments in dimension two with simulated noisy data suggest that the algorithm finds the inclusion‐free domain near Γ and is robust against measurement noise. © 2007 Wiley Periodicals, Inc. 相似文献
37.
Ryosuke Hyakuna Masayoshi Tsutsumi 《NoDEA : Nonlinear Differential Equations and Applications》2011,18(3):309-327
We consider the Cauchy problem for the nonlinear Schrödinger equations $ \begin{array}{l} iu_t + \triangle u \pm |u|^{p-1}u =0, \qquad x \in \mathbb{R}^d, \quad t \in \mathbb{R} \\ u(x,0)= u_0(x), \qquad x \in \mathbb{R}^d \end{array} $ for 1 < p < 1 + 4/d and prove that there is a ${\rho (p ,d) \in (1,2)}We consider the Cauchy problem for the nonlinear Schr?dinger equations
l iut + \triangle u ±|u|p-1u = 0, x ? \mathbbRd, t ? \mathbbR u(x,0) = u0(x), x ? \mathbbRd \begin{array}{l} iu_t + \triangle u \pm |u|^{p-1}u =0, \qquad x \in \mathbb{R}^d, \quad t \in \mathbb{R} \\ u(x,0)= u_0(x), \qquad x \in \mathbb{R}^d \end{array} 相似文献
38.
Time-dependent pattern entropy is a method that reduces variations to binary symbolic dynamics and considers the pattern of symbols in a sliding temporal window. We use this method to analyze the instability of daily variations in foreign exchange rates, in particular, the dollar–yen rate. The time-dependent pattern entropy of the dollar–yen rate was found to be high in the following periods: before and after the turning points of the yen from strong to weak or from weak to strong, and the period after the Lehman shock. 相似文献
39.
A laser terahertz-emission microscope (LTEM) system is proposed and developed for inspecting electrical faults in integrated circuits (IC). We test a commercial operational amplifier while the system is operating. Two-dimensional terahertz-emission images of the IC chip are clearly observed while the chip is scanned with a femtosecond laser. When one of the interconnection lines is cut, the damaged chip has a LTEM image different from that of normal chips. The results indicate that the LTEM system is a potential tool for IC inspection. 相似文献
40.
Daisuke Sawai Mika Miyamoto Tetsuo Kanamoto Masayoshi Ito 《Journal of Polymer Science.Polymer Physics》2000,38(19):2571-2579
No systematic study has been reported on the lamellar thickening in atactic poly(acrylonitrile) (PAN) upon annealing because PAN, in the form of solution‐cast films or their drawn products, generally shows no small‐angle X‐ray scattering (SAXS) maximum corresponding to the lamellar thickness. In this work, PAN crystals were precipitated during the thermal polymerization of acrylonitrile in solution. The nascent PAN film, obtained by the filtration of the crystal suspension, exhibited a clear SAXS maximum revealing the lamellar structure. The lamellar thickening upon annealing of the nascent PAN films was studied in the temperature range 100–180 °C, where the degradation was minimal, as confirmed by the absence of an IR absorption band at 1605 cm−1 ascribed to the cyclized nitrile groups. Above 190 °C, the degradation of the samples was significant, and the SAXS became too broad to determine the scattering maximum. The long period was significantly affected by the annealing time (ta) and the temperature (Ta). Depending on ta, three stages were observed for the lamellar thickening behavior. The lamellar thickness stayed constant in stage I (ta = 0.5–3 min, depending on Ta), rapidly increased in stage II (ta = 0.5–8 min), and stayed at a constant value characteristic for each Ta at yet longer ta's in stage III. The lamellar thickness characteristic for Ta increased rapidly with increasing Ta at 165 °C (or higher), which was 152 °C lower than the estimated melting temperature of PAN (Tm = 317 °C). A possible mechanism for such lamellar thickening in PAN far below the Tm is discussed on the basis of the enhanced chain mobility in the crystalline phase above the crystal/crystal reversible transition at 165–170 °C detected by differential scanning calorimetry and wide‐angle X‐ray diffraction. The structural changes associated with annealing are also discussed. © 2000 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 38: 2571–2579, 2000 相似文献
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