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文化的传播总体上来说是强势民族文化向弱势民族文化传播,但个别文化元素的传播可能是逆向的。文化的传播或涵化只有在存在文化差异(也即文化势差)的情况下才会发生,只有文化差异没有文化传承者的接触也不会产生文化的传播或涵化。但这种接触可以是文化传承者(人)的直接接触,也可以通过"场"的间接接触,接触的密切程度由若干因素确定。文化传播或涵化强度可以采用渗流理论(v=ki)或电流理论(I=V/R)来表达;接触的密切程度可以用渗透系数k或传导阻力R来表示,接触程度越紧密,文化传播或涵化的强度越大,即渗透系数k越大或传导阻力R越小;文化差异(文化势差)可以用水力坡降i或电势差V来表示,文化势差越大,文化的涵化或传播强度越大。 相似文献
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We propose a novel probabilistic method for detection of objects in noisy images. The method uses results from percolation and random graph theories. We present an algorithm that allows to detect objects of unknown shapes in the presence of random noise. The noise density is assumed to be unknown and can be very irregular. The algorithm has linear complexity and exponential accuracy, and is appropriate for real‐time systems. We prove results on consistency and algorithmic complexity of our procedure. © 2013 The Authors. Statistica Neerlandica © 2013 VVS. 相似文献
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储层的微观孔隙结构是指储集层中岩石的孔喉大小、分布及连通关系。有关储层微观孔隙特征的研究对于准确评价储集层性能及后续开采措施的选择尤为重要。采用恒速压汞法对南五区二类储层微观孔隙结构特征进行研究。根据压汞实验得到各微观孔隙结构的特征参数,与渗透率建立散点分布图,研究各孔隙结构参数对渗透率的影响程度,得出相关系数的大小,进而对各微观孔隙结构参数进行主次划分。在此基础上重点统计各主要参数的压汞实验结果,结合渗透率分布,得到各参数的平均值及分布范围,分析南五区二类储层的微观孔隙结构特征,为后续渗流规律及聚驱配伍性研究提供依据。 相似文献
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We consider ordinary independent percolation on the integer lattice, and construct consistent estimators for most of the important quantities associated to this model. We also present some simulation results. 相似文献
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刘建茂 《石家庄经济学院学报》1996,(2)
本文以均衡理论为基础,采用数理统计方法,通过对马庄矿区16年间丰水期最大矿坑涌水量与其对应的灰岩地下水水位降资料的研究,知二者为幂指数关系,从二者所建立的回归方程中,反推出马庄矿区的天窗渗漏量,进而推之。天窗的渗漏量主要取决于天窗下伏灰岩的岩溶发育情况和导水性,天窗的渗漏量只占矿坑涌水量的一小部分。对矿区的安全生产形不成威胁。 相似文献
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R.W.J. Meester 《Statistica Neerlandica》1994,48(3):237-252
The possible uniqueness of the infinite cluster in percolation theory has been a subject of research for more then three decades. A number of important results have been proved in the last eight years and most of the question posed thirty years ago are answered nowadays. In this review paper, I shall give an account on the history of the subject plus recent developments. My goal is not only to mention the main results, but also to give some idea of the methods of proofs which are involved. I also discuss some applications and open problems. 相似文献
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We propose a joint theory of time-series momentum and reversal based on a rational-expectations model. We show that a necessary condition for momentum to arise in this framework is that information flows at an increasing rate. We focus on word-of-mouth communication as a mechanism that enforces this condition and generates short-term momentum and long-term reversal. Investors with heterogeneous trading strategies—contrarian and momentum traders—coexist in the marketplace. Although a significant proportion of investors are momentum traders, momentum is not completely eliminated. Word-of-mouth communication spreads rumors and generates price run-ups and reversals. Our theoretical predictions are in line with empirical findings. 相似文献
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Cristiano Antonelli 《Empirica》1997,24(1-2):137-156
Technological cooperation has become more widespread in recent years. Percolation processes have been studied in physics as the outcome of four classes of forces termed as density, external pressure, connectivity and receptivity. In this paper the methodology of percolation processes has been adapted to interpret the dynamics of knowledge flows within innovation networks as communication systems and to understand the evolution of technological cooperation among firms both within and among industries. 相似文献
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