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Abstract:The grading entropy concept can be adapted to the field of geotechnics, to establish criteria for phenomena such as particle packing, particle migration and filtering, through a quantified expression of the order/disorder in the grain size distribution, in terms of two entropy-based parameters. In this paper, the grading entropy theory is applied in some geotechnical case studies, which serve as benchmark examples to illustrate its application to the characterisation of piping, softening and dispersive soils, and to filtering problems in the context of a leachate collection system for a landfill site. Further, since unstable cohesive (dispersive) soils are generally improved by lime, the effect of lime addition is also considered, on the basis of some measurements and a further application of the grading entropy concept, which allows evolutions in the entropy of a soil to be considered as its grading is modified. The examples described support the hypothesis that the potential for soil erosion and particle migration can be reliably identified using grading entropy parameters derived from grading curve data, and applied through an established soil structure OPEN ACCESSEntropy 2012, 14 1080 stability criteria and a filtering rule. It is shown that lime modification is not necessarily helpful in stabilizing against particle migration.

In this paper, an Electromagnetic Band Gap (EBG) lens of a single layer is invented to improve the gain of a truncated slotted square patch antenna for the Wi-Fi applications. The proposed EBG lens is structured from 55 planar array. The individual unit cell is basically shaped as a couple of a split concave conductive patch. The proposed EBG struc- ture performance is tested numerically using Finite Integration Technique (FIT) formulations of CSTMWS and analytically using circuit theory. Then, the antenna performance in terms of |S11|, the boresight gain, and radiation patterns are reported and compared to the performance before introducing the EBG lens to identify the significant enhancements. The proposed EBG antenna is simulated numerically inside FIT formulations of CSTMWS time domain (TD) solver. A significant gain enhancement of 11.1 dBi at 2.45 GHz and a front to back ratio (F/B) about 22 dB are achieved after introducing the EBG lens. The antenna performance is validated using a frequency domain (FD) solver based CSTMWS formulations to obtain excellent agreements between the two invoked methods.

This paper is an extension of previous work which characterises soil behaviours using the grading entropy diagram. The present work looks at the piping process in granular soils, by considering some new data from flood-protection dikes. The piping process is divided into three parts here: particle movement at the micro scale to segregate free water; sand boil development (which is the initiation of the pipe), and pipe growth. In the first part of the process, which occurs during the rising flood, the increase in shear stress along the dike base may cause segregation of water into micro pipes if the subsoil in the dike base is relatively loose. This occurs at the maximum dike base shear stress level (ratio of shear stress and strength) zone which is close to the toe. In the second part of the process, the shear strain increment causes a sudden, asymmetric slide and cracking of the dike leading to the localized excess pore pressure, liquefaction and the formation of a sand OPEN ACCESSEntropy 2015, 17 2282 boil. In the third part of the process, the soil erosion initiated through the sand boil continues, and the pipe grows. The piping in the Hungarian dikes often occurs in a twolayer system; where the base layer is coarser with higher permeability and the cover layer is finer with lower permeability. The new data presented here show that the soils ejected from the sand boils are generally silty sands and sands, which are prone to both erosion (on the basis of the entropy criterion) and liquefaction. They originate from the cover layer which is basically identical to the soil used in the Dutch backward erosion experiments.

With the imminent introduction of the 3G systems throughout the world precision cell planning in macrocell, microcell a d picocell environments become equally important. Beside coverage as the basic radio link qualily parameter others as m delay spread and a measure of the system capacity become increasingly important. Our contribution addresses the planning inside microcells based on a 3 0 deterministic ray-tracing propagation tool. It is based on the IHE model [I] and a simple genetic algorithm (SGA) for the base station location optimization. At this stage the optimization is based on coverage and rms delay spread considerations.Our algorithm has as inputs the delay spread threshold and the minimum field strength. The cost hnction to be minimized is the number of locations in which the values of these parameters are above the threshold in the case of delay spread, respectively below the threshold in the case of the field strength.