Volume 12 (2019): Edition 2 (December 2019)

In this work, we present a new fuzzy second-order sliding mode controller (FSOSMC) for wind power transformation system based on a doubly-fed induction generator (DFIG) using intelligent space vector pulse width modulation (SVPWM). The proposed command strategy combines a fuzzy logic and a second order sliding mode control (SOSMC) for the DFIG command. This strategy presents attractive features such as chattering-free, compared to the conventional first and second order sliding mode techniques. The use of this method provides very satisfactory performance for the DFIG command. The effectiveness of this command strategy is proven through the simulation results.

Based on Gauss’ law for the electric field, new formulas were deduced, that enable for the first time the writing of an analytical formula of the built-in potential of implanted and diffused semiconductor junctions. Consequently, in this work is devised a measurement technique for the built-in potential of such junctions. Such measurement is useful because new semiconductor materials besides silicon are more and more used today, like silicon-carbide (SiC) and gallium-nitride (GaN), which have larger bandgap and junction built-in potential. Finding the built-in potential helps adjusting the computer assisted design (CAD) tools and validates the simulation of such wide-bandgap devices.

At present the processing power of the digital electronic chip is enormous and that has been possible because of the continuous improvement of the design methodology and fabrication technology. So, the data processing capability of the chip is increased significantly. Data processing in the electronic chip means the arithmetic operation on that data. For that reason, ALU is present in any processor. Full adder is one of the critical components of arithmetic unit. Improvement of the full adder is necessary for improving the computational performance of a chip. In order to design an efficient full adder, designer should choose an appropriate logic style. In this research, two new model of full-adder circuits are designed and analyzed using Pass Transistor logic in order to reduce power consumption and increase operational speed. The first proposed adder consists of 8 transistors and the second one consists of 10 transistors. LTSPICE is employed for simulating the proposed circuits using16nm low power high-k strained silicon transistor model. The overall performance of the proposed adder circuits and comparative results demonstrate the superiority of the proposed model.

Automation of industrial activities aims to improve the efficiency of the productive processes while reducing costs and increasing safety. In industrial laundries, detergent management is a key factor that can lead to severe economic and environmental impacts if left uncontrolled. This paper documents the solution devised for an integrated detergent control and supervision system based on Internet-of Things paradigms. This solution follows from a problem put forward by the laundry services of Santa Casa da Misericórdia de Bragança, located in Portugal, to the Polytechnic Institute of Bragança. In order to keep track of the detergent in a centralised dispensing system, a Wi-Fi based measurement system was developed which enables real-time monitoring of the chemicals level. In order to facilitate the physical installation of the developed hardware, a custom-made enclosure was designed and 3D printed. The acquired data is then sent to a database connected to a data processing web-based platform which is responsible for the analytics.

This paper presents a method to increase the detection range for RFID readers in the UHF radio band. The design is following especially the ISO 18000-6C standardization demands for the UHF band, operating from 865 to 868 MHz in Europe and from 902 to 928 MHz in North America. These regulations are allowing the RFID tags to operate near the metallic surfaces and in a wider range than its counterparts at lower frequencies. The paper highlights the advantages offered by the array antenna, especially by the beamforming to increase the reader surveillance zone. The paper describes some additional techniques that are allowing the usage of the circular polarization to increase the reader sensing range and to improuve detection. The design starts with simulation and optimization using HFSS and ends with the measurements that validate the simulation results.

Machine-learning techniques allow to extract information from electroencephalographic (EEG) recordings of brain activity. By processing the measurement results of a publicly available EEG dataset, we were able to obtain information that could be used to train a feedforward neural network to classify two types of volunteer activities with high efficiency.

This paper is a review of the way in which the high-quality factor antennas can be used to integrate the VHF and HF car’s antennas in one device. The usage of the citizen band (CB) antennas in an HF band extends the environmental awareness of the driver and could increase the safety of the traffic. Usually, the citizen band transceiver with its antenna isn’t installed in a brand new car but the FM radio receiver it is. The main constraints that are related to the size difference between the two antennas (in FM and CB) make the main car manufacturers let the matter regarding the CB usage, open, at the choice of the buyer. The paper analyzes the technological advancements in the field and investigates some alternatives to the issue that will allow an opening through a single antenna usage for both radio bands.

Automatic guided vehicles (AGVs) play an important role in the small-scale industry as well as the largescale industry in handling materials inside factories from one place to another. In the last days, the materials to be handled are more numerous and as production and demand increase, it strongly influences the transport of materials in desperate need of a vehicle to distribute, position the materials within the industry. AGVs are generally installed with wires at ground level and signals are transmitted through them to be controlled. Due to the emergence of the AGV, the workload of the human being gradually decreased and the production efficiency increased. Thus, the need for an AGV has become more technologically important in the advanced robotic world. Normally, these systems are integrated into a global production system, where is a need to make direct changes in the design and planning of the floor store to get most of them. But in the rapidly changing production system and the adaptable floor store, the implementation of AGV has become very important and difficult, because it depends on many systems, such as wires, frequency, total production, etc. Therefore, it is necessary to develop an independent AGV, which can operate on its own and make decisions based on changes in the environment.

In order to be able to realize out the mixing detection or harmonic generation functions, a non-linear circuit is necessary for different existing devices and for performing these types of operation, in the submillimetric and / or far-infrared domains (10 μm ≤ λ ≤ 1 mm), the spectral margin covered by this radiation ranging from 300 GHz to 30 THz. In these frequency domains, non-linear point devices are often used, unlike the optical domain where massive devices are widely used, among them the Josephson Junction (JJ) is mainly used in the case where low noise is desired. This paper present electrical characteristic of Josephson Junction (JJ) using Approximation in the sense of Least Squares, for different value of C_j, T, R_j.

Development of increasingly efficient production methods is a competiveness driving factor for any company. Today, many of these improvements include the integration of technology-based solutions into processes traditionally operated by humans. In this context, the present work aims to report the controller performance of a prototype developed for semi-automatic sewing stations. This project was fostered by “Factory Play”, a Portuguese company that produces inflatable structures, under the technical supervision of the Polytechnic Institute of Bragança. At the present time, the sewing station travel speed is regulated by an embedded PID controller that has been previously tuned using classical methods. However, even if the overall performance is currently acceptable, additional experiments were made regarding the use of evolutionary based algorithms to attain a better dynamic response and flexibility. This article present the results obtained using those methods where it is possible to confirm that the use of evolutionary algorithm will simplify the design process while consistently leading to a suitable solution.