A study regarding the parameters that influence the growth rate of Salix alba

The inventory and evaluation of growth rates for afforested surfaces is extremely important in estimating production levels and in determining the wood quantities that can be harvested. The present research was realized in southeast Romania, on a surface that contains 375h of afforested fields. The monitored surfaces are situated in Hanu-Conachi Independenta Forest, at a relatively low altitude. The study took into account only the surfaces afforested with willow (Salix alba) and extended between 2010 and 2015. The afforested surfaces’ consistency and age were evaluated based on direct observations and measurements. The used numerical analysis on different optimization methods was selected from amongst the most used series from the specialty literature. Our results have shown that evaluations of estimated production growth rates can vary significantly when different statistical analyses and numeric methods are used. By using numerical optimizing models, computer simulations can offer precise estimations regarding growth rates, and consequently, for the efficiency of a given forest inventory. Common numerical interpolation methods or the usage of neuronal networks do not always lead to consistent results. Specific numeric methods are preferable for a better evaluation of growth rates and current inventory. In addition, investments in computer simulation methods and software should be encouraged in order to reach a permanent inventory, improve the efficiency of exploitation operations, and sustain environmental protection.

HERMITE NUMERICAL METHOD TO ESTIMATE THE RADON AND RADIUM EFFECTS OF THE SOIL IN BARTELLA REGION

The Hermite numerical interpolation method used to estimate and predict the radon and radium concentrations, from some of the experimental measurements made on the soil samples of the Bartella region in Iraq. The results obtained from deductible mathematical method were close to real experimental results. Predicted results are in the range of 80.04–4051.59 Bq/m3radon concentrations and 0.322–17.276 Bq/Kgradium concentrations corresponding to 200-10000 tracks of alpha particles. The maximum errors were less than 0.289 and 1.172 percent for radon and radium concentrations, respectively. The effects of radium and radon radiations estimated of soil in the studied area depend on its concentrations, a higher number of alpha particle tracks mean high radiation concentration, the high radiation will cause human health damage. The values are below 370 Bq/Kg the recommended radium concentration permissible values, by the Organization ащк Economic Cooperation and Development (OECD), the studied area is safe from hazards on health of radium and radon exposure from the soil

Measurement of cosmic radiation exposure of aircraft crew at commercial aviation altitudes

The measurement results of ambient dose equivalent rate in an aircraft, performed by a standard portable dosimeter, at a non-commercial flight Belgrade - Podgorica at altitudes up to 9000 meters, are shown. By numerical interpolation of the measurement results, a functional dependency of the ambient dose equivalent rate on the altitude of the airplane flight is determined, obtaining a good agreement with the reference values. For commercial airlines in the Balkan region, total ambient dose equivalent, regarding the aircraft crew occupationally exposed to radiation in the course of a flight, was calculated and the maximum permitted number of flight hours per year, was estimated.

Development of a novel diagonal-weighted Preisach model for rate-independent hysteresis

This article develops an alternative approach in modeling a hysteresis using Preisach model. A Preisach model is demonstrated geometrically by an inverted triangle, namely Preisach triangle, which contains an amount of fundamental operators. In a conventional Preisach model, these fundamental operators are ideal relays. Consequently, there exists an inherently discontinuous jump between two consecutive relays. To resolve this problem, in this work, a generalized linear operator is used as the fundamental elements. Correspondingly, its representative Preisach triangle consists of numerous discrete elements whose weight concentrates just along their diagonal. With such approach, it is possible to predict the response of the model according to any input without the aid of numerical interpolation tools. In addition, in this work, to determine the elements’ weights of the model, two accurate identification methods corresponding to two schemes of experimentally biased and unbiased dataset are developed. At last, several simulations and experiments are conducted to assess the effectiveness of the proposed approach showing comparative results with conventional Preisach model.

Experimental Validation of the Simulated Steady-State Behavior of Porous Journal Bearings1

This study deals with a comparison between new experiments on the frictional behavior of porous journal bearings and its prediction by previous numerical simulations. The tests were carried out on bearings lubricated with polyalphaolefin (PAO)-based oils of distinct viscosities. The theoretical model underlying the simulations includes the effects of cavitation by vaporization and accounts for the sinter flow by virtue of Darcy's law. The effective eccentricity ratio corresponding to the experimentally imposed load is estimated by an accurate numerical interpolation scheme. The comparison focuses on the hydrodynamic branches of the Stribeck curve by dimensional analysis (DA), where the variations of the lubricant viscosity with temperature are of main interest. The numerically calculated values of the coefficient of friction are found to reproduce the experimentally obtained ones satisfactorily well in terms of overall trends; yet, the former lie predominantly below the measured ones, which results in a low-positive correlation between the two.

GM-PHD Filter Combined with Track-Estimate Association and Numerical Interpolation

For the standard Gaussian mixture probability hypothesis density (GM-PHD) filter, the number of targets can be overestimated if the clutter rate is too high or underestimated if the detection rate is too low. These problems seriously affect the accuracy of multitarget tracking for the number and the value of measurements and clutters cannot be distinguished and recognized. Therefore, we proposed an improved GM-PHD filter to tackle these problems. Firstly, a track-estimate association was implemented in the filtering process to detect and remove false-alarm targets. Secondly, a numerical interpolation technique was used to compensate the missing targets caused by low detection rate. At the end of this paper, simulation results were presented to demonstrate the proposed GM-PHD algorithm is more effective in estimating the number and state of targets than the previous ones.