Threshold value of three dimensional bootstrap percolation

The following article deals with the critical value p_c of the three-dimensional bootstrap percolation. We will check the behavior of p_c for different lengths of the lattice and additionally we will scale p_c in the limit of an infinite lattice.Comment: 8 pages including 9 figures for Int.J.Mod.Phys.

Multidimensional isotonic regression and estimation of the threshold value

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A rational method for determining intermittency in the transitional boundary layer

A new rational procedure is proposed for determining the intermittency in the streamwise direction. One of the key parameters for the intermittency determination is the selection of a threshold value, which often involves a certain level of subjectivity. Here, a reliable way of choosing the threshold value in a more objective manner is proposed. The proposed approach involves a single threshold value, equal to the magnitude of the maximum laminar perturbation in the transitional flow. The results obtained are validated with the widely used dual-slope method. In this paper, the measurements are carried out on an experimental arrangement, involving the interaction of an upstream aerofoil wake with a downstream flat plate boundary layer. As a by-product of the study, a scaling parameter has been identified which captures the length of the transition zone as the proximity of the aerofoil in the wall-normal direction is varied

The Fertility-Development Relationship in the United States: New Evidence from Threshold Regression Analysis

This study employed a threshold regression analysis (Hansen, 2000) to examine the relationship between per capita Gross Domestic Product (GDP) and total fertility rate (TFR) in the United States. The United States is the only developed country where the declining fertility rate was reversed and recovered to the replacement level of 2.1. The findings indicate that there was a statistically significant threshold in the fertility-development relationship and a reverse in the fertility decline. The threshold value of real per capita GDP based on the Laspeyres index was US$22,267, while the threshold value of real capita GDP based on the Fisher index was US$21,264. This means that the decline in the fertility rate could be reversed when per capita income reached US$21,000-US$22,000. The empirical findings also indicate a significant negative relationship between per capita GDP and TFR when income level in the country was below the threshold value. This negative association between the two variables reversed to a positive relationship when income level had exceeded the threshold value. The findings of this study confirm the existence of a J-shaped fertility-development relationship in the United States.

A distributed key establishment scheme for wireless mesh networks using identity-based cryptography

In this paper, we propose a secure and efficient key establishment scheme designed with respect to the unique requirements of Wireless Mesh Networks. Our security model is based on Identity-based key establishment scheme without the utilization of a trusted authority for private key operations. Rather, this task is performed by a collaboration of users; a threshold number of users come together in a coalition so that they generate the private key. We performed simulative performance evaluation in order to show the effect of both the network size and the threshold value. Results show a tradeoff between resiliency and efficiency: increasing the threshold value or the number of mesh nodes also increases the resiliency but negatively effects the efficiency. For threshold values smaller than 8 and for number of mesh nodes in between 40 and 100, at least 90% of the mesh nodes can compute their private keys within at most 70 seconds. On the other hand, at threshold value 8, an increase in the number of mesh nodes from 40 to 100 results in 25% increase in the rate of successful private key generations

Adaptive thresholding in dynamic scene analysis for extraction of fine line

This paper presents an adaptive threshold method whereby a fine thin line of one-pixel width lines could be detected in a gray level images. The proposed method uses the percentage difference between the mean of the pixels within a window and the center pixel. The minimum threshold value however is heuristically set to 32. If the percentage difference is greater than 40% then the threshold value will be set to the difference value. This method has been applied in detecting moving objects with fine lines and the results showed that the method was able to pickup straight thin edges that belong to the moving objec