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161.
In this paper, by means of double elliptic equation expansion approach, the novel double nonlinear wave solutions of the (2+1)-dimensional break soliton equation are obtained. These double nonlinear wave solutions contain the double Jacobi elliptic function-like solutions, the double solitary wave-like solutions, and so on. The method is also powerful to some other nonlinear wave equations in (2+1) dimensions. 相似文献
162.
163.
A. V. Chebotnikov 《Journal of Applied Mechanics and Technical Physics》2009,50(3):441-446
This paper gives experimental data on the propagation speed and height of a dam-break wave arising in the tailwater region
during a partial dam break event. These data were used to confirm the Khristianovich calculation method.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 50, No. 3, pp. 97–103, May–June, 2009. 相似文献
164.
E. N. Bereslavskii 《Fluid Dynamics》2008,43(5):763-771
The underground contour of an embedded rectangular dam, whose corners are rounded in accordance with curves of constant flow velocity and whose water-permeable base is underlain by a confining layer with a curvilinear roof characterized by a constant flow velocity, is constructed. The corresponding boundary value problem is solved by means of the semi-inverse use of the velocity hodograph method. The results of the numerical calculations are given and the effect of the main determining parameters of the model on the shape and dimensions of the underground contour of the dam and the curvilinear confining layer is analyzed. The limiting cases in which the water-permeable base of the dam has an unbounded thickness, namely, a streamlined apron with a horizontal insert and streamlined sheet piling (tooth), are investigated in detail. 相似文献
165.
运用能够识别资本市场结构突变与区制变化的Markov区制转换模型,基于非线性相依结构研究中的藤Copula分析框架,文章以考察人民币汇率市场化进程中的结构相依与突变特征为切入点,重点研究两次汇改以及金融危机时期人民币汇率在四个阶段的结构转换及非对称动态相依特征。文章采用GJR-GARCH模型探讨人民币汇率市场的"杠杆效应"。在此基础上,文章对两次汇改以及美国次贷危机时期人民币汇率市场的结构突变和区制转换的进行识别。研究发现,Markov区制转换模型能够准确地捕捉到人民币汇率第一次汇改的临界点,但在捕捉第二次汇改临界点方面却存在一定的滞后反应。并且,该模型对美联储采取第一轮量化宽松的货币政策的捕获,也表现出较好的能力。进一步地,文章运用藤Copula分析框架探讨了不同人民币汇率市场之间的非线性相依结构。研究表明,整体而言,采用t-Copula的藤结构在捕捉人民币汇市之间的相依结构方面表现出良好的刻画效果。 相似文献
166.
DNA双链断裂产额的新算法 总被引:2,自引:3,他引:2
DNA双链断裂(DSB)的定量分析是高传能线密度辐射生物学效应机理研究的重要手段.从实际应用出发,推导了一个新的计算公式———平均分子量法.该法不探究DSB片段的具体分布模式,实际操作中却又包含了片段的含量和分布;而且形式简单、操作简便,尤其适合于荧光扫描数据. Quantitive analysis of DNA double strand break (DSB) is of importance for studying on the mechanisms of radiobiological effects induced by high linear energy transfer(LET) irradiation. For the practical use, one new calculating formula named the method of average molecular weight is deducted. In this method, the factual distribution of DSB fragments is not considered, but actually, the content and distribution of DSB fragments are included. Totally, this method is simple in shape and easy to use, esp... 相似文献
167.
168.
拱坝体型的多目标模糊优化设计 总被引:11,自引:0,他引:11
在拱坝体型的优化设计中 ,传统的以经济指标为目标函数的数学模型 ,有一定的局限性。本文综合考虑拱坝的安全性与经济性 ,建立了多目标优化设计的数学模型。模型解决了多目标函数及拉应力控制标准的模糊性。小湾拱坝的优化计算结果表明了模型的合理性与可行性 相似文献
169.
170.
Are structural break models true switching models or long memory processes? The answer to this question remains ambiguous. In recent years, many papers have dealt with this problem. Some studies have shown that, under specific conditions, switching models and long memory processes can easily be confused. In this paper, using several generating models (the mean-plus-noise model, the stochastic permanent break model, the Markov switching model, the threshold autoregressive (TAR) model, the sign model, and the structural change model) and several estimation techniques (the Geweke–Porter–Hudak (GPH) technique, detrended fluctuation analysis (DFA), the exact local Whittle (ELW) method, and wavelet methods) we show that, even if the answer is quite simple in some cases, it can be mitigated in other cases. Using French and American inflation rates, we found that the most appropriate process that takes into account the important features of these series is a model that simultaneously combines changes in regimes and long memory behavior. The main result of this study indicates that estimating a long memory parameter without taking into account the presence of breaks in the data sets may lead to misspecification and hence to overestimating the true parameter. 相似文献