Eng. Proc., 2023, EEPES'23

The rapid emergence of the 5G networks has posed a number of new planning problems, which should be carefully analyzed to optimize the installation of the new technologies and to integrate them into the existing mobile network. The main planning objectives are to build up a network satisfying the expected traffic demands in its various sections, in compliance with the performance quality targets suggested by international committees International Telecommunication Union (ITU), Comité Consultatif International pour la Radio (CCIR), etc. The following paper discusses some of the main aspects which should be evaluated in the planning stage of 5G radio relay transmission, such as traffic capacity, propagation problems, and interference problems. Full article

This article investigates the influence of planet mounting position on axle loads in double planet planetary gear trains. The study includes basic information about the type of geartrain used, theoretical data, finite element analysis simulations, and empirical experiments to provide more detailed data on the impact of planet pin position on bearing loads in different scenarios. A test model with six different setups is designed for the studies. Finite element simulations were then conducted to examine the model and to give more comprehensive information on the effect of pin location. Empirical experiments were conducted on a test rig to verify the theoretical and simulation results. The results indicate that the position of the planet pins has an impact on the distribution of load between the bearings of the outer and inner planets of the gear train. This study aims to provide more insights into the design and optimization of planetary gear trains when evaluating the loads on the bearings of the planet gears. Full article

Microstructural characteristics and mechanical properties of nano-reinforced cementitious mortar using multi-walled carbon nanotubes (MWCNTs), dispersed in an aqueous solution by applying ultra-solicitation, were studied using X-ray microcomputed tomography (micro-CT), an innovative, non-destructive technique. This useful method was applied for characterizing the cementitious composites’ spatial micro-pore structure. The changes due to the MWCNTs’ integration into the mortar matrix and their effects were studied. The analysis revealed that the density and porosity values processed by micro-CT imaging are crucial parameters. They correlated with the mechanical strength of 2 × 2 × 8 prisms (in cm) in order to evaluate the dispersion effect of the different nanotube concentrations, 0.1 wt.%, 0.2 wt.%, 0.3 wt.%, and 0.5 wt.% by the mass of cement. The results highlight the linear correlation of the density, porosity, and spatial pores’ distribution obtained by the micro-CT 3D in vivo imaging of the microstructure, with the nanotubes’ concentration and flexural and compressive strengths. This investigation was achieved by proving that a deeper understanding of the complex nano- and microstructures can be utilized for the design of advanced cementitious composites at multiple scales. Full article

The issue of increasing the efficiency of the information-control system for monitoring the spatial orientation of objects in geophysical surveys by improving the filtering of sensor signals in the stationary part of the system is considered in this study. For this purpose, an approach is proposed to reduce the bandwidth when connecting bandpass filters of the same type in series. Ratios are obtained that allow one to accurately determine frequencies and bandwidth. Full article

As autonomous driving is quickly becoming a reality, the most considerable challenge with self-driving remains safety, as the car must process surroundings to make the correct predictions. This paper explores the detection and classification of moving objects, such as vehicles and pedestrians, on a pixel level. Using the CARLA simulator, we collected data from a single front-facing camera, thus excluding standard sensor technologies like lidar or radar. This research aims to test the generalization capabilities of models trained using front-camera images on inputs from differently positioned cameras capturing 360 surroundings. We tackle the described challenge with the task of instance segmentation using the most famous instance segmentation algorithms: Mask Region-based Convolutional Neural Network and YOLOv7. We show to what extent a monocular setup can be used for the instance segmentation of the perspectives that differ from the baseline captured by the front camera. Full article

The exponential development of wireless applications has increased problems in the spectrum. The unlicensed frequency spectrum is becoming highly saturated, in order to support the conditions of new radio devices with increasing data rates. The spectrum that has previously been allocated is also unused. As a consequence of these developments, scientists have been putting a lot of effort into developing an approach to the issue of the limited spectrum that could make it possible to create a more effective utilization of it. As cognitive radio permits opportunistic use of the licensed spectrum in less crowded areas, it has been proposed as a solution to this challenge. This paper provides an overview of the cognitive radio environment, including a dynamic spectrum access strategy, as well as additional information on the cognitive capabilities operating in combination IoT communication technologies. We investigate the utilization of cognitive radio in the Internet of Things along with the significant role that cognitive radio plays in making the Internet of Things possible. Cognitive radio will provide a comprehensive examination of spectrum sensing, which will cover the many types of sensing, sensing that is based on machine learning, as well as open topics that still need to be addressed further in this sector. This research paper is written in a way that provides detailed instructions for the purpose of assisting new researchers in the area of Cognitive Radio Networks. Full article

Many goods require certain conditions for their storage, such as temperature, humidity and arrangement, which are strictly specific. These include dangerous goods, medicines and goods with a limited shelf life. Servicing them in warehouses is an important task in order to be able to establish and monitor the flow of their transportation from the manufacturer’s warehouse to the end user. In this context, the use of modern technologies, such as IoT, makes it possible to facilitate the activity of logistics centers on the storage, receipt and loading of goods, tracking their location and condition, as well as the inventory of their availability. This paper proposes an integration model of blockchain technology and IoT for logistics business. This model uses smart contracts on the blockchain, and it is suitable for managing cross-docking warehouses and transportation. Full article

Correct implementation of circular economy measures is essential for achieving sustainable development criteria with a growing share of the world’s population and global product consumption. This article examines the problem of ensuring a quality life for residents in the city of Ruse by increasing the efficiency of the water supply based on IoT and blockchain technologies. For the application of the technology, the regulatory, technical, socio-economic, and financial areas are classified, which must be updated according to the functionality of the water supply system. The current state of the automated water supply system has been studied. The digitization of a dispatcher is proposed for working IoT. Hyperledger Fabric is selected as a suitable DLT platform. A communication scheme is proposed for sharing data with citizens, repair companies, and regulatory bodies in the event of an accident. Full article

In recent years, wireless sensor networks (WSNs) have attracted rising interest due to their significant role in Internet of Things (IoT) applications. One of the most important layers of the IoT is known as edge computing, and WSNs typically act as microcontroller-driven edge objects. It is a well-known phenomenon that objects composing a WSN are resource-constrained devices in terms of energy. This paper aims to revisit the traditional ALOHA protocol as a medium-access control with the purpose of creating a solar-powered energy source. A simple network of 6 objects is created to test the performance of the ALOHA protocol in terms of its lifetime. The performance results reveal that the network lifetime can be increased by controlling the parameters, such as transmission power level and packet length. Full article

Due to climate concerns, most countries are looking for alternative ways to generate energy in a clean, efficient, and environmentally friendly way. Currently, a practical and technically feasible solution can be obtained by integrating a gas turbine and a solid oxide fuel cell to form a hybrid system. Experimental studies of the thermophysical, electrochemical, and other internal processes in solid oxide fuel cells are an expensive procedure, so theoretical tools such as simulations are very important in the analysis and design of solid oxide fuel cell stack systems. In this work, a 3D model of a planar fuel cell was studied. Numerical modeling was carried out, taking into account the flow channel design, the movement of thermal air, and fuel flows. A calculation of the thermodynamic parameters of a solid oxide fuel cell with hydrocarbon fuel has been carried out. In conclusion, some constructive perspectives and recommendations for future research are offered. Full article

In South Africa, traditional transportation has become more expensive and not easily accessible to everyone. The current use of internal combustion engine (ICE) vehicles in the transport sector has been contributing about 14% to the country’s greenhouse gas emissions. In booking any e-hauling service, most of the current transportation requires pre-booking or standing in long queues to make a booking. These transactions require usually physical cash or insertion of card details online to process a booking payment. The outcome is prone to hackers and theft. Therefore, this paper focuses on the design and building of a safe electronic booking and payment application software for inter-campus e-bikes through a Quick Response (QR) code and Near-Field Communication (NFC). The application also encourages the use and integration of clean energy solutions in the transport sector and the saving of waiting time for inter-campus ICE buses as students would rather use e-bikes for their inter-campus mobility. Also, they can transact safely, affordably, and securely for their mobility costs using the developed application. Full article

In late December 2019, a cluster of previously unidentified coronavirus cases emerged in Wuhan, China. Subsequently, the virus quickly spread to the whole world in a matter of few months. At that point in time, there were no known treatments for COVID-19. Therefore, to limit the spread of virus transmission, the public was advised to maintain social distancing and wear a face mask. In Malaysia, most people were compliant and adhered to the standard of procedure (SOP). However, it was observed that many people were not wearing the mask correctly. Therefore, this paper aims to analyze how image classification using machine learning algorithms can be used to detect whether a face mask is properly worn. In this research, a total of 1222 color images (selfies) were used to build five machine learning models, in particular Naïve Bayes (NB), Support Vector Machine (SVM), Decision Tree (DT), Random Forest (RF) and K-Nearest Neighbors (KNN), to classify three methods of mask-wearing: mask correctly worn, mask incorrectly worn, and mask not worn. Our results show that Decision Tree is the best model among these five models in terms of accuracy (85.7%), precision (85.9%), recall (85.7%), and F1-Score (85.7%). However, it was observed that when classifying mask-wearing images the decision tree approach was not able to identify images with a similar pattern, for example, in the cases of mask under the nose and mask correctly worn. From an awareness perspective, this study emphasizes the need for the public to properly wear their face mask to reduce the spread of COVID-19 and the effectiveness of image classification in detection of face mask wearing. Full article

The paper contains a description of the building model structures and fuzzy control strategy. The aim of work was to describe fuzzy logic applied to the temperature control approach. The Simulink model of a widely popular building automation was used. The structure and the design aspects of a fuzzy logic control in the frame of classical control system manners of its realization were carried out. It can be viewed as a basement of intelligent control for further improvement. The simulation experiments with applied classical and fuzzy control action were conducted. The comparison results with conventional control law were obtained to highlight the advantages. The model of the room heating system and simulation results can be used and easy shifted to the real building management strategy. Full article

The large-scale deployment of renewable energy sources (RESs) has sped up the transition to clean energy systems in response to depleting fossil fuel supplies and rising environmental concerns, resulting in a significant percentage of RES generation in power systems globally. A focused design that considers local limits is necessary for a more significant share of renewable energy in the power output. Setting clear rules for how to proceed, where to begin, and what expertise is required to accomplish such plans and efforts can help achieve this. A case study on the Greek interconnected electrical system in Crete considers two scenarios with high-RES penetration. The simulation’s findings demonstrated that using RESs may considerably boost their penetration while also resulting in considerable fuel cost reductions. Full article

The unprecedented transformation of contemporary power systems, mainly evidenced by the high penetration of renewable energy generation and the shift from passive to active, bi-directional smart grids, has put an extraordinary burden on power system operation and control. The uncertainties created by the two aforementioned factors greatly propel the necessity of more accurate and robust system monitoring. Concurrently, an ever-increasing amount of electronics-based power generation makes frequency stability a major challenge to power system operation and control due to the vastly diminishing system inertia. As a crucial part of system control, frequency monitoring is utilized to identify potential stability issues and eventually prevent cascading power outages and blackouts. This paper proposes a dynamic state estimation (DSE) methodology that employs deep learning (DL) techniques based on feed-forward artificial neural networks (ANN) to accurately predict power system disturbances in terms of frequency disturbance events (FDE) caused by line outages, load/generation tripping events, and various types of faults. The proposed methodology was tested on a test grid model with high penetration of renewable generation, using an open-source data generator. It was concluded that DL-based DSE can be successfully utilized in the FDE detection process to improve frequency monitoring and control, and to maintain optimal performance, stability, and security of power systems. Full article

The ankle exoskeleton is an auxiliary device designed to restore human independence. This paper proposes the development and initial testing of a passive ankle exoskeleton designed for movements with dorsal and plantar flexion. The device also includes a new mechanism design with four electric linear actuators, and the shank platform and the foot platform are connected to the ball by a swivel joint. Mechanical tests demonstrate the ability of the prototype to function adequately in the natural range of the ankle joint. Preliminary results show that the exoskeleton can reduce the activation of the calf muscles on the limb on which the device is installed. In the investigation of a passive ankle joint exoskeleton designed for movements with dorsal and plantar flexion, numerical test results can be highlighted by focusing on parameters such as speed, acceleration, and translation moment. These measurements provide valuable information about the performance and effectiveness of the exoskeleton. By focusing on these numerical test results, it is possible to obtain an idea of the performance of the exoskeleton, understand its impact on the movements of the ankle joint, and make informed decisions for further improvements or optimization of the design. Full article