Although numerically very efficient the finite element method exhibits difficulties whenever the remeshing of the analysis domain must be performed. For such problems utilizing meshless computation methods is very promising. In this paper, a kind of meshless method called the element-free Galerkin method is introduced for electromagnetic field computation. The mathematical background for the moving least square approximation employed in the method is given, and the numerical implementation is briefly discussed. Application of the proposed method for electromagnetic field computation and verification of the obtained results using theoretically known solution is also presented.

The boom of the tourism industry has led to a huge interest in investing largely in hotel lodgings. Tourists have become aware and started considering new and far from ordinary tourist issues, like environmental protection, waste treatment measures, energy efficiency, renewable energy, green-house gas emissions, etc. The aims of the study are three-fold: (i) to assess the application of energy efficiency practices in the hotel industry; (ii) to explore the determinants of energy consumption; and (iii) to pose valuable recommendations for boosting development of eco-friendly hotels. The research was conducted in Macedonia for the purpose of identifying the impacts of several factors of managing environmental protection practices, in the first line by measuring their current level of influence. The data were obtained by an online survey conducted among managers of three-, four-and five-star hotels and processed by descriptive statistics. The results showed that managers have high positive perceptions on environmental protection issues and pose high awareness of the benefits produced by this concept, thus supporting the European environmental impact assessment regulation. The study recommends new approaches in challenging the hotel industry to decrease the operating costs and suggests that managers are in need for better understanding of the importance of energy efficiency.

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In this paper, an extension of the previously developed 2-D dynamic bubble system for 3-D automatic mesh generation using tetrahedral finite elements is presented, Initially, a set of vertices inside the entire analysis region is generated using 3-D dynamic bubble system, followed by automatic mesh generation according to the Delaunay tessellation algorithm and the generated set of vertices. The proposed method is highly robust and easily applicable to convex and concave analysis domains with various geometrical complexity. The proposed method provides high quality tetrahedral meshes with graded mesh densities utilizing very small amount of input data.

Mesh quality strongly affects the solution accuracy in electromagnetic finite-element analysis. Hence, the realization of adequate mesh generation becomes a very important task. Several adaptive meshing methods for automatic adjustments of the mesh density in accordance with the shape and complexity of the analyzed problem have been proposed. However, the most of them are not enough robust, some are quite laborious and could not be universally used for adaptive meshing of complex analysis models. In this paper, a new adaptive mesh refinement method based on magnetic field conservation at the border between finite elements is proposed. The proposed error estimation method provides easy mesh refinements, and generates smaller element within regions with large curvature of the magnetic flux lines. The proposed adaptive mesh refinement method based on non-conforming edge finite elements, which could avoid generation of flat or ill-shaped elements, was applied to a simple magnetostatic permanent magnet model. To confirm the validity and accuracy, the obtained results were compared with those obtained by means of the Zienkiewicz-Zhu (ZZ) error estimator. The results show that the computational error using the proposed method was reduced down to 1% compared with that of the ZZ method, which yields error of 8.6%, for the same model

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An immersive real-time visualization system of 3D magnetic field for educational purposes is presented. This immersive visualization system is based on augmented reality technology. The proposed system provides observation of a magnetic field distribution and its stereoscopic vision in 3D space using head mounted display. To improve the visualization capabilities, a new realtime method for drawing magnetic flux lines in 3D space is developed and presented in this paper. It enables a user to easily observe and grasp a magnetic field generated by multiple sources (e.g., magnets and/or multiple coils) in an augmented 3D space. Additionally, it permits a user to freely and interactively move the magnetic sources within the visualization space and to observe the magnetic fields interference in real-time. As a result, one can intuitively and easy visualize, observe and grasp the magnetic field even in 3D space.

An immersive real-time visualization system of 3-D magnetic field for educational purposes is presented. This immersive visualization system is based on augmented reality technology. The proposed system provides observation of a magnetic field distribution and its stereoscopic vision in 3-D space using head mounted display. To improve the visualization capabilities, a new real-time method for drawing magnetic flux lines in 3-D space is developed and presented in this paper. It enables a user to easily observe and grasp a magnetic field generated by multiple sources (e.g., magnets and/or multiple coils) in an augmented 3-D space. Additionally, it permits a user to freely and interactively move the magnetic sources within the visualization space and to observe the magnetic fields interference in real-time. As a result, one can intuitively and easy visualize, observe and grasp the magnetic field even in 3-D space