rss_2.0Bulletin of the Polytechnic Institute of Iași. Electrical Engineering, Power Engineering, Electronics Section FeedSciendo RSS Feed for Bulletin of the Polytechnic Institute of Iași. Electrical Engineering, Power Engineering, Electronics Section of the Polytechnic Institute of Iași. Electrical Engineering, Power Engineering, Electronics Section Feed Synchronous Electric Machine with Variable Geometry Done by Elastic Permanent Magnets<abstract><title style='display:none'>Abstract</title> <p>The paper refers to an electric machine (motor/generator) with an adjustable magnetic field, because its rotor has a special construction that allows the deformation of its elastic permanent magnets. The permanent magnets deform due to a clamping stroke parameter and in this way the flux density of the magnetic field as well as the width and length of the permanent magnets are variable. The variable magnetic field crosses the stator coils which are supplied by the voltages and due to a variable magnetic flux density, a higher torque will result even at lower values of the currents. As a result, a higher efficiency will be obtained due to the increase in mechanical power and the decrease in losses (e.g., Joule effect) in the stator windings. The presented electric machine is a synchronous machine with variable geometry, belonging to the category of permanent magnet machines. Specific to this machine is the fact that the rotor magnets are elastic, being made of ferritic compound rubber with neodimium magnets N45.</p> </abstract>ARTICLEtrue Line Swithcing Considering Circuit Breaker Standard Deviation Times<abstract><title style='display:none'>Abstract</title> <p>The switching of electrical equipment in normal operation conditions should be performed in optimal moments with regard to the variation of the voltage and current waveforms. Deviations from these ideal conditions will result in disruptive transient regimes, which, depending on their severity, can lead to equipment malfunctions or insulation damage. This paper continues a previous research study regarding the impact of the real switching moment regarding the known ideal conditions on various types of equipment. Previous efforts have concentrated on the study of the behavior of capacitor banks, power transformers and underground cable lines when switching is performed in different points on the voltage sine wave. This paper continues the research by studying high voltage overhead lines in the same conditions. The voltage and current waveforms are measured and analyzed for different switching times, using the EMTP software package. A comparison discussion with the previous results highlights the main findings.</p> </abstract>ARTICLEtrue Regarding Electrical Equipment Monitoring Through Infrared Thermography<abstract><title style='display:none'>Abstract</title> <p>In the paper are highlighted the main advantages of wireless monitoring methods present in the market for electrical equipment temperature surveillance. Also, are considerate the mandatory corrections applied to the thermographic image in order to adjust the electrical equipment temperature. In the final part, there are shown the resulted values of an infrared thermography inspection performed in industrial environment, which reveals the thermal stresses identification of the busbar’s connections from a medium voltage switch separator. In addition, the paper present why a highly reflexive surface is not suitable for infrared thermography, and in what manner affects the data obtained from the monitoring devices.</p> </abstract>ARTICLEtrue Key Elements for Increasing Localization Precision of the VRUs in 5G NR Environments<abstract><title style='display:none'>Abstract</title> <p>The growing number of road accidents and fatalities created a necessity for applications exploiting communication between traffic actors like vehicles, vulnerable road users (VRUs), and infrastructure. To determine the vehicle position and to communicate this data to the traffic users, the vehicles and user’s smart devices are equipped with communication modules and positioning modules. The fifth generation (5G) cellular network promises to respond to the requirements of a city traffic management by: ultra-low latency, reliability, and position determined with high precision. The 3GPP Release 16 mobile communications standard details the use-cases of the industrial verticals and their requirements, the most important key performance indicators (KPIs), and technologies that the new radio (NR) architectural component uses to obtain the position information. 3GPP Release 16 targets a positioning accuracy between 1 and 3 meters for traffic monitoring and control, as well as for wearable devices. Moreover, the standard specifies the most common solutions that the 5G technology can support. This paper aims at presenting the context of the positioning essentials that the 5G NR can support, which are necessary to achieve road users’ protection and congestion avoidance within an urban area.</p> </abstract>ARTICLEtrue Innovation Methodology that Combines Computerized Modelling and Simulation with Value Analysis and Engineering Method<abstract><title style='display:none'>Abstract</title> <p>Current research responds to the need to add value to a product right from the conception phase and incrementally whenever the product’s customers demand it. Thus, this paper presents a hybrid method of adding value to a single-phase asynchronous motor by combining computerized modelling and simulation of a single-phase asynchronous motor with an incremental innovation technique based on value analysis and engineering for functional optimization of this device. The methodology combines these two techniques to obtain a customer-oriented product with optimally dimensioned functions that correspond to the needs of the device’s customers. The novelty of the work consists of the research methodology, which includes the application of functional analysis method during the design and redesign stages of a single-phase asynchronous motor.</p> </abstract>ARTICLEtrue Brief Overview of Federated Learning - A New Perspective on Data Privacy<abstract><title style='display:none'>Abstract</title> <p>While privacy concerns remain the main challenge starting with the promulgation of the General Data Protection Regulation (GDPR), for deep learning applications, Google introduced recently the Federated Learning (FL) technique to offer support for high privacy-sensitive data, which makes FL a hot research topic nowadays. Thus, it is a distributed machine learning technique in which multiple devices (clients) collaboratively train a global model to solve issues where the first concern is data privacy. This work provides a brief study of FL: an overview of this new topic, related works, a comparison with other machine learning techniques, an overview of algorithms that are currently used, and, in the end, some simulation results and new directions of research. The simulations show the distributed behavior of the FL algorithm and the way in which the Federated Averaging method can be applied. Through the performed analysis of the obtained results, it was figured out that approach would be beneficial for several applications in domains like automotive, 5G and others.</p> </abstract>ARTICLEtrue Software Interface of a Hybrid FES and Mechatronic Exoskeleton System for Hand Rehabilitation in Stroke People<abstract> <title style='display:none'>Abstract</title> <p>This paper introduces novel contributions to the field of hand rehabilitation systems designed for stroke patients. The primary objective is to enhance voluntary movements in the paralyzed upper limbs, with a particular focus on hand functionality. The system, known as MANUTEX, comprises two main components: functional electrical stimulation (FES) implemented through a textile glove with embedded electrodes, connected to a programmable neurostimulator, and a mechatronic exoskeleton resembling a glove, powered by individual linear motors for each finger. These linear motors are controlled by a programmable microcontroller on a central board. MANUTEX delivers mirror therapy, a therapeutic approach requiring a sensory glove attached to the healthy hand. This sensory glove provides reference movements for the hybrid system located on the affected, impaired hand. An application installed on a computer serves as the control interface for the entire system. It reads movement data from the healthy hand and concurrently sends commands to both the FES and mechatronic exoskeleton glove, ensuring a balanced and synchronized therapeutic experience for the patient.</p> </abstract>ARTICLEtrue Use of Formants’ Correlation in Assessing the Sadness State of the Speakers<abstract> <title style='display:none'>Abstract</title> <p>The purpose of this study is to further the comparative analysis of the variations in the correlation coefficients of the formants for the Romanian vowels during emotional speech. We created an annotated speech database composed of recordings of speakers pronouncing the following sentences: /v<bold>i</bold>n<bold>e</bold> m<bold>a</bold>m<bold>a</bold>/ (/mother is coming/), /<bold>a</bold>s<bold>ea</bold>r<bold>ă</bold>/ (/last night/), /c<bold>i</bold>n<bold>e a</bold> f<bold>ă</bold>c<bold>u</bold>t <bold>a</bold>st<bold>a</bold>/ (/who did this/), first on a neutral tone of voice, and then expressing sadness.</p> <p>The analysis focuses on the influence that sadness has on the vocal signal. The formants and F0 (pitch) of each vowel were extracted. Statistical analysis techniques were applied in order to verify whether the variation of the correlation coefficients between F0 and F1-F4 presents significant variations or whether it tends to be homogenous under the following conditions: (1) same speaker – same vowel – different sentences; (2) same speaker – same vowel – emotional neutrality vs. sadness; (3) different speakers – same sentence – same vowel.</p> </abstract>ARTICLEtrue of Low Frequency Magnetic Field of Indoor Distribution Substations<abstract> <title style='display:none'>Abstract</title> <p>In this paper we presented some measurements of the low frequency magnetic field from indoor distribution substation. Using two automatic measuring instruments we made both spot measurement and automatic long-term survey presenting the spatial and temporal variability of the magnetic field in five areas with indoor distribution substation. Correlating the time of spot measurement, with that of automatic survey we estimate the magnetic field values to reduce the errors due to the temporal variation. With the values obtained after estimating the field, we draw maps for the entire zone of an indoor distribution substation. The results were compared with the maximum permissible limits by national and international standards and we found that they were not exceeded. However, in all five areas the values of the magnetic field were above the threshold of 400 nT taking into account long-term exposure, which can lead to biological effects on health, especially for children.</p> </abstract>ARTICLEtrue Device for Monitoring ECG and PPG Signals - Design and Redesign Based on Value Engineering Method<abstract> <title style='display:none'>Abstract</title> <p>In the current medical, social, and technological context, where cardiovascular diseases have a high incidence in mortality statistics, dynamic social life, and rapid technological advancements, computerized systems for monitoring personal health parameters, independent of the medical system, are in great demand. The current research aims to design a prototype of a computerized system for monitoring cardiac activity (ECG and PPG) and improve it through functional optimization using an incremental innovation method based on value engineering applied to the product. This paper presents the stages of physical prototyping, device design based on its primary functions, functional optimization through balancing the cost-effectiveness ratio for each function, selecting device redesign solutions, and implementing them in the final product. The novelty of this research lies in the physical realization of a cardiac activity monitoring prototype and the application of an incremental innovation methodology and device redesign. The research falls within the technical field -through the development of the ECG-PPG prototype - and the economic field -through the application of functional analysis to improve this device.</p> </abstract>ARTICLEtrue Approach in Ring Voltage Controlled Oscillator Design for V.C.O. Based Analog to Digital Conterters<abstract> <title style='display:none'>Abstract</title> <p>This paper introduces a procedure that relies on Computer Aided Design tools (industry compatible SPICE simulator and MATLAB) to get a first rapid design solution for a ring voltage controlled oscillator (VCO) that can be further analyzed and optimized for usage in a VCO based analog to digital converter (ADC). Due to the fact that linearity is a key performance metric of an ADC a special attention will be given to this characteristic during the design and for this matter control mechanism will be analyzed. To exemplify the design procedure two different delay cell topologies (simple inverter and pseudo-differential cross-coupled inverters) will be analyzed and designed in a 130 nm CMOS technology.</p> </abstract>ARTICLEtrue Assessment for Auxiliary Power Supply System of a Nuclear Power Plant Based on the Monte Carlo Simulation<abstract> <title style='display:none'>Abstract</title> <p>This paper presents a reliability assessment of the Auxiliary Power Supply System (APSS), Class IV of a Nuclear Power Plant (NPP) using the Monte Carlo simulation method. The paper highlights the important role of the APSS in ensuring safe and efficient operation of the plant. The paper provides an introduction to the concept of reliability, emphasizing its significance in the context of NPP. A description of Monte Carlo simulation method is also provided, including its underlying principles and its application to reliability analysis. The paper then describes the role and structure of APSS. A study case is presented to demonstrate the effectiveness of the proposed method in evaluating system reliability. The results of the study suggest that the Monte Carlo simulation method can effectively method to predict the reliability of the APSS.</p> </abstract>ARTICLEtrue Led Matrix Manager Sniffer<abstract> <title style='display:none'>Abstract</title> <p>This paper is focused on presenting the simulated solution for synchronizing the CAN communication, which is signal based, with the Pulse Width Modulation (PWM) for each LED connected to a LED matrix manager device. Using the presented solution, the user is able to read and verify each LEDand represents a very easy and fast testing approach for automotive lighting with LMM (LED Matrix Manager) devices. The information provided by the sniffer improves the error root cause detection time, offers an overview on the requirements compliance, and assures an efficient monitorisation of the LMM behaviour. The LMM sniffer is developed due to the missing of a dedicated standard solution for this purpose.</p> </abstract>ARTICLEtrue Analog - Discrete Nonlinear Systems<abstract> <title style='display:none'>Abstract</title> <p>Using nonlinear chaotic systems for secure communication is an application field presented in recent published research. This paper aims at improving the security of signal transmission using chaotic encryption. The proposed approach uses a combined analogue and discrete-time structure, for both chaotic emitter and synchronizing receiver. The prototype system used is similar to the Lorenz nonlinear oscillator. Our study presents the emitter dynamic properties, develops the receiver synchronization using the emitter partitioning method, and designs a linear equalizer at the receiving end of the communication chain in order to improve the demodulated signal.</p> </abstract>ARTICLEtrue Real-Estate Image Analysis for Retrieval and Classification<abstract> <title style='display:none'>Abstract</title> <p>Nowadays, the real estate sector is also benefiting from the advance of the technology. Digital images accompany announcements advertising for renting or selling a property. Computer vision and image analysis contribute to the understanding of these images towards better consumer experience. In this paper we show how retrieval and description can be used efficiently to isolate cvasi-duplicate images and identify similar examples to the ones that have drawn viewer’s interest. Three problems related to real-estate imaging are identified and solutions are proposed and evaluated on large databases.</p> </abstract>ARTICLEtrue Comparative Energy and Exergy Analysis Between Organic Rankine Cycle and Kalina Cycle System 11 for the Waste Heat Recovery of a PEM Fuel Cell Power Station<abstract> <title style='display:none'>Abstract</title> <p>In this study, the performance analysis of waste heat recovery systems in a power generation system consisting of 13000 Proton Exchange Membrane Fuel Cells (PEMFC) in a stack has been investigated. Organic Rankine Cycle (ORC) and Kalina Cycle System 11 (KCS11) as bottoming cycles to convert generated waste heat of stack into electricity were compared with each other in a defined hybrid system. The improvement of system with an exact energy and exergy analysis after utilizing the waste heat in the hybrid system has been analyzed. Results show that the energy efficiency of combined system using Organic Rankine Cycle and Kalina Cycle System 11 increase by about 5% and 1.75% respectively. In addition, exergy analysis results indicate that exergy efficiency of combined system using Organic Rankine Cycle and Kalina Cycle System 11 increases by about 4% and 1.5% respectively. The total exergy destruction rate obtained for the hybrid power systems is 235.5 kW when ORC is used and 329.7 kW when KCS11 is used respectively. Results show that in presented systems ORC has higher energy and exergy efficiencies than KCS11 but different used working fluids and equipment of systems must also be considered from an economical point of view.</p> </abstract>ARTICLEtrue Short Survey of the Development and Applications of Spiking Neural Networks of High Biological Plausibility<abstract> <title style='display:none'>Abstract</title> <p>Spiking neural networks (SNNs) are inspired from natural computing, modelling with high accuracy the interactions and processes between the synapses of the neurons focusing on low response time and energy efficiency. This novel paradigm of event-based processing opens new opportunities for discovering applications and developing efficient learning methods that should highlight the advantages of SNNs such as the large memory capacity and the fast adaptation, while preserving the easy-to-use and portability of the conventional computing architectures. In this paper, we do a brief review of the developments of the past decades in the field of SNNs. We start with a brief history of the SNN and summarize the most common models of spiking neurons and methods to implement synaptic plasticity. We also classify the SNNs according to the implemented learning rules and network topology. We present the computational advantages, liabilities, and applications suitable for using SNNs in terms of energy efficiency and response time. In addition, we briefly sweep through the existing platforms and simulation frameworks for SNNs exploration. The paper ends with conclusions that show predictions of future challenges and the emerging research topics associated with SNNs.</p> </abstract>ARTICLEtrue of Focal and Non-Focal Epileptic Eeg Signals Using Different Types of Classifiers<abstract> <title style='display:none'>Abstract</title> <p>Epilepsy is a neurological disorder characterized by recurrent seizures and has a high incidence rate. The aim of this research is to classify EEG signals as either focal and non-focal in order to identify the epileptogenic area of the brain, which can be surgically treated to manage epilepsy. In this paper, was proposed a classification method based on higher order spectra (HOS) parameters and four different classifiers: linear discriminant analysis (LDA), quadratic discriminant analysis (QDA), k-Nearest neighbors (KNN), and Mahalanobis distance (MD). The method was evaluated using a public dataset that consists in EEG recordings from epileptic patients. The classifiers performances were evaluated and it was shown that KNN classifier achieves a maximum classification rate of 99.55%, sensitivity of 100%, and specificity of 99.09%. The data classification was performed with maximum values of 0.96 for F1-score, and 0.91 for both Kappa and Matthews Coefficient. The results demonstrate the efficiency of the proposed method to identify the type of EEG signals.</p> </abstract>ARTICLEtrue Reliability and Safety Improvement of Measurement and Control Processes on Ships: Implementation of Wireless Hart Protocol<abstract> <title style='display:none'>Abstract</title> <p>Measurement and control systems in maritime engineering applications are quite similar to those in shore based engineering applications except for some unique features which differentiate between each of them. These features are either related to the specific nature and purpose of the maritime application (Various types of commercial ships, oil/gas rigs and others) or linked to the harsh environmental conditions such as salinity, corrosion and vibration which usually exist in higher levels than shore based applications. Accordingly and due to such a specific nature of maritime engineering applications, more requirements should be considered to ensure reliability and stability for measurement and control process avoiding any negative effects that might be associated with such a unique engineering environment. As was discussed in (Abotaleb, 2021), smart transmitters based on hybrid analogue-digital (HART) and digital (Foundation Fieldbus and Profibus PA) communication protocols with additional diagnostic information, they might be a possible wired alternative for analogue transmitters (mostly based on 4-20 mA analogue standard). Similarly, wireless HART protocol can be an alternative for 4-20 mA analogue transmitters. This article will discuss the possibility of replacing classical 4-20 mA analogue transmitters with wireless HART smart transmitters on commercial ships as an example for maritime engineering application. The first section of the discussion will include a theoretical background for the basic principles of wireless HART protocol among other wireless technologies used in industrial automation. The second section of the article will discuss the possibility of utilising wireless HART protocol in the most common measurement and control systems on any commercial ship in order to discover the degree to which wireless HART can be fully or partially integrated with maritime engineering applications. Afterwards, better realization for such a concept will be rendered by an analytical planning case study conducted for tank level measurement system on different types of commercial ships. Based on both the theoretical and the analytical sections, the experimental section will manifest the importance of some of the necessary key elements to implement a reliable wireless HART network. These key elements are RSSI levels, supply voltage stability and the capability of wireless HART adapters to integrate between wired HART protocol and wireless HART network.</p> </abstract>ARTICLEtrue System Operating in Ambient Air for Surface Treatment of Polyethylene Terephthalate Films<abstract> <title style='display:none'>Abstract</title> <p>Polymers are materials widely used in many important technologies and applications because of their optical, physical, mechanical, thermal and chemical properties. Polyethylene terephthalate (PET) foil is often used as an insulating material in printed electronics, flexible circuitry, displays, industrial applications, graphic films, or for clinical and healthcare applications. A big inconvenience of PET film is the low surface tension which also implies a low wettability, resulting in poor coating adhesion and poor printing properties. In order to eliminate this disadvantage, a surface treatment was used by means of a dielectric barrier discharge (DBD) operating in ambient air at atmospheric pressure which consisted of a high voltage AC source and two circular metal electrodes 60 mm in diameter. The paper aims are to treat two different PET film substrates designed in this work as PET 1, without thermal treatment, and PET 2 which is heat stabilized. The effect of plasma exposure was assessed by determining the water contact angle by means of an Ossila goniometer and by measuring the surface tension with a special ink. The considered foils were exposed to different DBD treatment times (0.2, 0.5, 1, 5, 10, 30 s) and the evolution of the water contact angle overtime after treatment up to 96 hours was monitored. It was found that the water contact angle of the untreated PET 1 and PET 2 was 74° and 73.5°, respectively, and after 30 s DBD treatment time it decreased to 30.9° and 30°, respectively.</p> </abstract>ARTICLEtrue