Random Characteristics of Hydraulic Gradient through Three-Dimensional Multilayer Embankment

The distribution characteristics of hydraulic gradient in embankment are closely related to seepage failure. Seepage failures such as flowing soil and piping will lead to serious damage and even the overall failure of embankment. The hydraulic conductivity has strong spatial variability, which changes the distribution of hydraulic gradient in embankment and increases the difficulty for predicting the embankment seepage instability. In this study, the distribution of soil hydraulic conductivity in a section of Shijiu Lake embankment was obtained by the permeability test. Based on Local Average Subdivision technique, a three-dimensional multilayer random field of embankment hydraulic conductivity was generated. Then, the mean and standard deviation of overflow point height and hydraulic gradient were calculated by the Monte Carlo method, which combined the generated three-dimensional random model and the deterministic analysis method of seepage field. Finally, the coefficient of variation (COV) of hydraulic conductivity (0.1, 0.3, 0.5, 0.7, 1.0, 2.0, and 3.0), the fluctuation scale in vertical direction (3 m) and the fluctuation scale in horizontal plane (3 m, 6 m, 12 m, 24 m, 36 m, and 48 m) were selected respectively for analyzing the random characteristics of embankment overflow point height and hydraulic gradient under the influence of different COV and fluctuation scale of embankment soil hydraulic conductivity.

Solving partial differential equations in deformed grids by estimating local average gradients with planes

For constructing physical science based models in irregular numerical grids, an easy-to-implement method for solving partial differential equations has been developed and its accuracy has been evaluated by comparison to analytical solutions that are available for simple initial and boundary conditions. The method is based on approximating the local average gradients of a field by fitting equation of plane to the field quantities at neighbouring grid positions and then calculating an estimate for the local average gradient from the plane equations. The results, comparison to analytical solutions, and accuracy are presented for 2-dimensional cases.

Energy capable clustering method for extend the duration of IoT based mobile wireless sensor network with remote nodes

The energy performance of IoT-MWSNs may be augmented by using a suitable clustering technique for integrating IoT sensors. Clustering, on the other hand, requires additional overhead, such as determining the cluster head and cluster formation. Environmental Energy Attentive Clustering with Remote Nodes is a unique environmental energy attentive clustering approach for IoT-MWSNs proposed in this study methodology (E2ACRN). Cluster head (CH) in E2ACRN is entirely determined by weight. The residual energy of each IoT sensor and the local average energy of all IoT sensors in the cluster are used to calculate the weight. Inappropriately planned allocated clustering techniques might result in nodes being too far away from CH. These distant nodes communicate with the sink by using more energy. The ambient average energy, remoteness among IoT sensors, and sink are used to determine whether a distant node transmits its information to a CH in the previous cycle or to sink in order to lengthen lifetime. The simulation results of the current technique revealed that E2ACRN performs better than previous clustering algorithms.

Comparison of Soviet and post-Soviet Russian settlement systems with the US settlement system, 1959-2020

The lack of discernible changes in the Russian (hereinafter RF) settlement system after the transition from a centrally managed economy to a capitalist economy seems to be contrary to the established view of the exceptional character of capitalist-style settlement systems. To explain this misunderstanding, we compared the state of settlement systems in Russia and in the United States between 1959 and 2020 in this paper. The measures of shape of the Pareto curve were used to quantify the state of the settlement systems: critical exponent, asymmetry coefficient, and Gini coefficient. The study found that the system of settlement in RF territories during the Soviet and post-Soviet periods had the same order and development trend as the system of settlement in US states. The order of urban systems in regions correlates with the local average annual temperatures. The results have led us to conclude that the settlement systems were independent from the economic paradigm.

Instrumental Variable Estimation in Demographic Studies: The LATE interpretation of the IV estimator with heterogenous effects

Heterogeneous effects of treatment on an outcome is a plausible assumption to make about the vast majority of causal relationships studied in the social sciences. In these circumstances the IV estimator is often interpreted as yielding an estimate of a Local Average Treatment Effect (LATE): a marginal change in the outcome for those whose treatment is changed by the variation of the particular instrument in the study. Our aim is to explain the relationship between the LATE parameter and its IV estimator by using a simple model which is easily accessible to applied researchers, and by relating the model to examples from the demographic literature. A focus of the paper is how additional heterogeneity in the instrument – treatment relationship affects the properties and interpretation of the IV estimator. We show that if the two kinds of heterogeneity are correlated, then the LATE parameter combines both the underlying treatment effects and the parameters from the instrument – treatment relationship. It is then a more complicated concept than many researchers realise.

Effects of repeated passages of a wheeled tractor on some physical properties of clayey loam soil

The objective of the study was to quantify the differences in soil physical indicators between inter-track (uncompacted) zone and track (compacted) zone created by four passages of a wheeled tractor (Landini Globus 70/DBKL Techno). Field studies were carried out on plots of the Vicarello experimental station, Tuscany (43° 27‘ N, 11° 30‘ E). A local average annual precipitation is 678 mm and average annual air temperature is 12.7 °C with absolute extreme values -10 °C and 40 °C. Bulk density, moisture content, water-stable aggregation, and penetration resistance were determined by conventional methods in the 0–0.40 m soil layers. The results showed that the 0.05–0.10 m soil layer, compared to the 0.20–0.25 m and 0.35–0.40 m soil layers, showed a higher degree of compaction by tractor wheels. In this soil layer, significant (at P <0.05 and <0.01) differences between the inter-track and track zone were observed for bulk density (1.18 ±0.10 g.cm−3 and 1.35 ±0.10 g.cm-3) and moisture content (24.9 ±2.3% and 27.9 ±2.3% of volume). Passages of tractor even resulted in an insignificant increase of total amounts (from 66.2 ±4.7% to 68.6 ±2.7%) and mean weight-diameters (from 2.29 ±0.30 mm to 2.40 ±0.04 mm) of water-stable aggregates. There were no significant differences in average penetration resistance of the uppermost 0–0.10 m soil layers between the inter-track (0.77 ±0.26 MPa) and track zone (0.64 ±0.12 MPa). Average soil penetration resistance was significantly (P <0.001) higher in the 0–0.40 m layer of the track zone (1.07 ±0.23 MPa) than in that of the inter-track zone (0.76 ±0.11 MPa).