Zastosowanie analizy planimetrycznej w badaniach geologicznych – eksperymenty i spostrzeżenia

Planimetric analysis is a well-known and commonly used method for determining the content of a given component in the area of the analyzed surface. In geology, it is used to determine both the mineral and maceral composition, and its results are helpful in solving a wide range of research problems. The aim of this study was to investigate the relationships between the obtained results of planimetric analysis and the density of the measurement grids, which can be adapted to specific situations in geological samples in order to optimize the ratio of the accuracy of the result to the time of analysis. The research was divided into two stages. Models were used in the first stage, while in the second, coal samples were investigated. In the first stage, a virtual grid of measurement points with dimensions of 100 by 100 points was created, which gave a total of 10 000 points. After creating the measurement grid model, 102 scenarios were established, differing in the content of the analyzed component A (0.1%, 0.5% and from 1 to 100%). In each of the adopted scenarios, 100 combinations were carried out so that the arrangement of points on the measurement grid corresponding to component A was random. Then, the number of measuring points was reduced several times from the original 10 000 to 100 and each time content of component A was calculated. The obtained average component A content in most cases turned out to be only slightly different from the original, which cannot be stated in the case of both minimum and maximum values – here a wider range of results is observed. In the second stage, 3 coal samples of varying maceral composition complexity were investigated and a measurement grid of 100 by 100 points was used. The original grid density was gradually reduced (down to 144 points) and maceral composition was calculated each time. Results obtained from models as well as from samples show a clear trend of decreasing accuracy with decreasing density of the measuring grid. The obtained results were also analyzed in terms of the established acceptance criteria for which the content of the component was assumed to be different from its content based on a grid of 10 000 points by up to 5%, 10% or 30% of the original value. The analysis of the relationship between the accuracy of the obtained results and the time of conducting the analysis seems to indicate that the choice of the measurement grid based on 500 points is optimal.

A Binary Integer Programming Method for Optimal Wind Turbines Allocation

The present study introduces a Binary Integer Programming (BIP) method to minimize the number of wind turbines needed to be installed in a wind farm. The locations of wind turbines are selected in a virtual grid which is constructed considering a minimum distance between the wind turbines to avoid the wake effect. Additional equality constraints are also included to the proposed formulation to prohibit or enforce the installation of wind turbines placement at specific locations of the wind farmland. Moreover, a microscopic wind turbine placement considering the local air density is studied. To verify the efficiency of this proposal, a square site was subdivided into 25 square cells providing a virtual grid with 36 candidate placement locations. Moreover, a virtual grid with 121 vertices related with a Greek island is also tested. All simulations conducted considering the area of geographical territory, the length of wind turbine blades, as well as the capacity of each turbine.

A Two-Way Nesting Unstructured Quadrilateral Grid, Finite-Differencing, Estuarine and Coastal Ocean Model with High-Order Interpolation Schemes

The balance between the need of improving horizontal resolution in simulating local small-scale ocean processes and computational costs makes it desirable to refine model mesh locally. A three-dimensional, two-way nesting unstructured quadrilateral grid, primitive equations, finite-differencing, estuarine and coastal ocean model is developed for multi-scale modeling. Because the model grid is capable of multi-area nesting and multi-level refinement at each subdomain, the model is highly compatible with simulations involved in complex topography and studies of local small-scale ocean processes. The two-way information exchange is achieved by a virtual grid method, and its basic idea is to implement numerical integrations of variables at nesting interfaces with the support of virtual grid variables, which are interpolated or updated from actual grid variables. The model is novel for two interpolation schemes: the high-order spatial interpolation at the middle temporal level (HSIMT) parabolic interpolation scheme and HSIMT advection-equivalent interpolation scheme, and they have high-order accuracy and good consistency with the advection scheme applied to solving the tracer equations. The conservation of both volume and tracer contents is ensured via a flux correction algorithm. The two original interpolation schemes are examined in an ideal salinity advection experiment in the peak preservation skill, stability, and conservation properties. A realistic application to the Deep Waterway Project area in the Changjiang Estuary showed that the nested grid model can reproduce the hydrodynamic processes at the observed sites successfully while it failed to maintain the performance with the structured grid model in simulating the variance of salinity, for which the enforced conservation had primary responsibility. The HSIMT parabolic interpolation scheme was distinguished from other schemes for its outstanding performances in simulating salinity.

A new modification of LEACH for efficient energy in WSN

<p>The limited energy of nodes in wireless sensor networks and the<br />impossibility of replacing their batteries, have lead to protocols development<br />which optimize and balance the energy consumption over the network.<br />LEACH is the most used hierarchical protocol. However, one major<br />weakness of the LEACH protocol lies in both of its random cluster formation<br />and cluster head election. In this paper, we present two new protocols based<br />virtual grid clustering on coverage area. In the first one, sensing area is<br />devided into grids as squares named as VSG-LEACH and in the second one<br />into grids as hexagons named as VHG-LEACH. In each zone, one cluster<br />head is elected according to its residual energy and its distance from the cell<br />center. The simulation results show that the network lifetime is prolonged by<br />169.67% and the energy consumption is improved by 80.97% compared to<br />LEACH protocol.</p>

A WSN Clustering Multi-Hop Routing Protocol Using Cellular Virtual Grid in IoT Environment

By dividing the grid and clustering multi-hop algorithm, the lifetime of WSN can be prolonged effectively, and the reliability of the system can be improved. In order to prolong network lifetime and balance network energy consumption, a WSN clustering multi-hop routing protocol for electric vehicles using cellular virtual grid is proposed. The routing mechanism divides cells into regular hexagons. In the cluster head selection stage, the node angle ratio, distance ratio, and throughput optimization threshold function are introduced to select cluster heads independently. In data transmission, single hop in cluster and mixed hop between clusters are used to optimize the path and reduce energy consumption when transmitting data among cluster head nodes. In the routing protocol, the path cost from the intermediate node to the target node is calculated according to the distance and residual energy. The simulation results show that the protocol has obvious advantages in reducing network energy consumption compared with several traditional algorithms when the running time reaches 1200 s and the network coverage is high.