The present work aimed at improving the quality of operational risk estimation for power substations and increasing the efficiency in its reduction using models and methods of multicriteria decision-making. The application of the proposed methodology allows one to assess, compare, prioritize, and/or order power substations from the point of view of operational risks and to rationally allocate available resources to reduce operational risks. It is presented a method of Systemic Risk Assessment (SRA) that integrates concepts of risk assessment and multicriteria decision-making techniques. The use of SRA permits one to take into account expert opinions to obtain the operational risk estimates. These estimates serve for allocating resources between substations within the framework of multicriteria models. The analysis is based on applying the Bellman-Zadeh approach to decision-making in a fuzzy environment to solve multicriteria problems and provide their harmonious solutions. The risk assessment results of the three power substations show that the power substation (PS)2 has the highest risk level (0.314), followed by PS1 (0.267), and PS3 (0.199), and the allocation of financial resources between the substations is the following: PS1: R $\$ $ 465,000.00, PS2: R $\$ $ 1,714,339.00 and PS3: R $\$ $ 820,661.00. The Case Study, demonstrates the possibility of reducing the subjectivity of the risk evaluation and the improvement of the quality of the decisions made in resource allocation.

This paper presents a simple methodology to measure the shielding quality in coaxial cables and connectors through the Shielding Effectiveness (SE) parameter at high frequencies. The discovery of complications as soon as possible is of paramount importance in order to avoid unpredicted costs in advanced phases of the project. This proposal describes an SE measurement setup using standard Electromagnetic Compatibility instrumentation such as electric field probe, signal generator, and power meter in a semi-anechoic shielded chamber and comparing physical measurement with computational simulations. A virtual model has been created based upon the physical coaxial cable, respecting dimensions and materials characteristics. The agreement between measurements and simulations is good in the considered frequency range 240 MHz to 3 GHz.

This paper presents a set of measurements in order to experimentally study transfer impedance of coaxial cable RG 213. Both the transfer impedance (Zt) and the Shielding Effectiveness (SE) are essential in the considerations of the EMC project. In this context, this work presents a procedure to measure the transfer impedance of two coaxial cables RG 213 under the same conditions and compare the measurements with theoretical references. The results of transfer impedance (Zt) measurements and theoretical references are quantified through the Feature Selective Validation technique.

The interference in adjacent cells and the control of the boundaries have being vastly investigated since the conception of the first cell phone networks. A very large number of small cells are required for new 5G mobile networks, and therefore it is even more important to determine the correct mobile station positioning as well as the control boundaries. In order to minimize these problems, this paper proposes a simple and efficient system that improves the control of the Mobile Management Entity (MME) defined in the Release 8 of 3GPP. The system uses a tracking arrangement capable of determining the direction of the mobile station in the cell area. This information can be used to predict handover between adjacent nodes (changing of cell) minimizing a great problem, the high traffic in the backhaul network. In order to reach these goals, two or more receiver antennas are used as a Radio Direction Finder (RDF) and phase controlled directional antennas or massive multiple-input and multiple-output antennas pointing to different irradiation channels towards different directions. The theoretical section developed in this study was successfully confirmed by the experimental setup with results very closed to the developed formulation.

This article presents a set of measurements and simulations that evaluate the technical feasibility of a Compact Open Area Test Site (COATS), for the frequency range of 200 MHz to 2 GHz. Its main goal is to provide shielding effectiveness measurements. The described test setup is used for the tests in both semi anechoic chamber and COATS. These experimental and computational results offer orientations and guidelines about the best method to measure radiated emission in a COATS. These measurements results can be quantified through the Feature Selective Validation technique.