Inventions

The objective of this study is to design a hull-mounted sonar dome of a ship using OpenFOAM with a bulbous bow effect at cruise speed in calm water. Verification and validation for the original sonar dome simulation are conducted. Next, the 1.44 million grid size is selected to study different dome lengths. By protruding the dome forward 7.5% of the ship’s length, the optimal 17% resistance reduction is achieved and is mainly caused by the pressure resistance decrease. The optimal sonar dome not only functions in the same way as a bulbous bow, but the viscous flow behaviors are also improved. The protrusion corresponding to 90 deg phase lag reduces the bow wave amplitude. The flow acceleration outside the boundary layer and ship wake velocity are higher coinciding with the much lower total resistance. A smaller flow separation and thinner boundary layer are also observed behind the sonar dome because its back slope is less steep. The high pressure covers a smaller area around the bow, and the smaller bow wave crest does not hit the ship’s flare to form high pressure. Consequently, the lower high pressure on the dome front and higher low pressure on the dome back result in the decreases in pressure resistance. The vortical structures are also improved. Full article

This article presents the constraining factors that limit the increase in the efficiency of logging production by modern multi-operation machines operating on the Scandinavian cut-to-length technology in the felling phase, namely the selection and registration of wood species. The factors for creating a complete architecture of a fully connected neural network (NN) are given. The dependence of the prediction accuracy of a fully connected NN on a test sample on the size of the training dataset, and an image of the dependence of the prediction accuracy on the number of trees in the random forest method for image classification is shown. For a fully connected NN, a sufficient number of images and a test sample size were established for training, using tree-trunk breed-class labels as target values. A selected list of trees was given, with the size of the training sample of images presenting a problem for the classification of tree trunks using the random forest method. The aim was the discovery of the optimal number of trees necessary to achieve prediction accuracy. Full article

We present a comparative study aiming to determine the most efficient multivariate model screening for the main drugs of abuse based on their ATR-FTIR spectra. A preliminary statistical analysis of selected spectra data extracted from the public SWGDRUG IR Library was first performed. The results corroborated those of an exploratory analysis that was based on several dimensionality reduction methods, i.e., Principal Component Analysis (PCA), Independent Component Analysis (ICA), and autoencoders. Then, several machine learning methods, i.e., Support Vector Machines (SVM), eXtreme Gradient Boosting (XGB), Random Forest, Gradient Boosting, and K-Nearest Neighbors (KNN), were used to assign the drug class membership. In order to account for the stochastic nature of these machine learning methods, both models were evaluated 10 times on a randomly distributed subset of the whole SWGDRUG IR Library, and the results were compared in detail. Finally, their performance in assigning the class identity of three classes of drugs of abuse, i.e., hallucinogenic (2C-x, DOx, and NBOMe) amphetamines, cannabinoids, and opioids, were compared based on confusion matrices and various classification parameters, such as balanced accuracy, sensitivity, and specificity. The advantages of each of the illicit drug-detecting systems and their potential as forensic screening tools used in field scenarios are also discussed. Full article

The aim of the study was to develop a methodology for calculating and optimizing devices for the magnetic exploration of fossils containing materials with a high magnetic permeability. The proposed technique is based on the calculation of electrostatic fields perturbed by conducting bodies and of magnetic fields perturbed by ferromagnets with a high magnetic permeability. It uses an integral equation of the first kind. This technique is preferable to the technique consisting in the use of an integral equation of the second kind, since in the situation under consideration, the latter does not have a unique solution and requires transformation. Prospects for the development of this area allow one to bring geophysical services to the service market on a new scientific and technical production level; reduce the environmental burden on nature by replacing magnetometric measurements with energy-saving, environmentally safe technology; and ensure the export potential of magnetometric equipment. Full article

This paper aims toward the successful detection of harmful materials in a substance by integrating machine learning (ML) into laser-induced breakdown spectroscopy (LIBS). LIBS is used to distinguish five different synthetic polymers where eight different heavy material contents are also detected by LIBS. Each material intensity-wavelength graph is obtained and the dataset is constructed for classification by a machine learning (ML) algorithm. Seven popular machine learning algorithms are applied to the dataset which include eight different substances with their wavelength-intensity value. Machine learning algorithms are used to train the dataset, results are discussed and which classification algorithm is appropriate for this dataset is determined. Full article

Ankle sprains are among the most prevalent musculoskeletal system injuries. Prevention of ankle sprains is important, given the frequency of occurrence of an ankle sprain, the risk of reinjury, and its long-term effects. A systematic patent review using the World Intellectual Property Organization (WIPO)’s PATENTSCOPE database has been performed to study the current development of ankle sprain prevention methods. Using the PRISMA statement as a basis, a total of 426 patent documents have been selected for review, consisting of 150 granted patents and 276 patent applications. In the past decade, China and the United States of America (43% and 29% of the patent applications, respectively) have shown great interest in developing ankle sprain prevention methods. Approximately 49% (or 74) of the patents from the 150 granted are associated with braces, 46% (or 68) are related to orthosis, 3% (or 5) are related to tape, and the remaining 2% (or 3) are associated with other types of ankle sprain prevention methods. This patent review shows that inventors are leaning towards braces and orthosis as the main prevention methods for ankle sprains, with greater interest in orthosis in recent years. Additionally, patents on smart wearable devices suggest initial commercial interest in the development of smart wearable devices as an ankle sprain prevention method. Full article

In this paper, the authors introduce the reader to the state of the art of Metal Wire Additive Manufacturing (MWAM) and provide a comparison between Wire Arc Additive Manufacturing (WAAM), Wire Laser Additive Manufacturing (WLAM), and Laser Arc Hybrid Wire Deposition (LAHWD) based on their characteristics and potential future applications, since MWAM is expected to have a promising future in various areas, such as aerospace, automotive, biomedical, and energy fields. A detailed discussion of the benefits and drawbacks of each Metal Wire Additive Manufacturing process can help to improve our understanding of the unique characteristics of metal wire application. Therefore, this paper offers a comprehensive analysis that can serve as a reference for upcoming industrial projects and research initiatives, with the aim of helping industries choose the most appropriate WAM technique for their specific applications. Full article

An electromagnetic thruster is proposed and successfully tested. Its design is inspired by theoretical considerations whose qualitative predictions are well matched with the experimental results. The efficiency is higher than any other device so far reported in the literature, producing a directional thrust of approximately $2.7\times {10}^{-6}m$, where m is the mass of the thruster itself, with a nominal power injected of approximately 10 Watts. The prototype has the shape of a ring and is powered by both radio frequency signals and a stationary high voltage. Improvements and generalizations can be easily devised by adjusting the geometry of the device. Full article

During the COVID-19 pandemic, which emerged in 2020, many patients were treated in isolation wards because of the high infectivity and long incubation period of COVID-19. Therefore, monitoring systems have become critical to patient care and to safeguard medical professional safety. The user interface is very important to the surveillance system; therefore, we used web technology to develop a system that can create an interface based on user needs. When the surveillance scene needs to be changed, the surveillance location can be changed at any time, effectively reducing the costs and time required, so that patients can achieve timely and appropriate goals of treatment. ZigBee was employed to develop a monitoring system for intensive care units (ICUs). Unlike conventional GUIs, the proposed GUI enables the monitoring of various aspects of a patient, and the monitoring interface can be modified according to the user needs. A simulated ICU environment monitoring system was designed to test the effectiveness of the system. The simulated environment and monitoring nodes were set up at positions consistent with the actual clinical environments to measure the time required to switch between the monitoring scenes or targets on the GUI. A novel system that can construct ZigBee-simulated graphical monitoring interfaces on demand was proposed in this study. The locations of the ZigBee monitoring nodes in the user interface can be changed at any time. The time required to deploy the monitoring system developed in this study was 4 min on average, which is much shorter than the time required for conventional methods (131 min). The system can effectively overcome the limitations of the conventional design methods for monitoring interfaces. This system can be used to simultaneously monitor the basic physiological data of numerous patients, enabling nursing professionals to instantly determine patient status and provide appropriate treatments. The proposed monitoring system can be applied to remote medical care after official adoption. Full article

High-quality luxury products cater to a specific group of consumers due to their durability and the value attached to them. Counterfeiting luxury products has resulted in economic losses for both the producers and consumers. The market for counterfeit luxury products has continued to grow due to the difficulty in authenticating genuine luxury products. The traditional system of verification largely depends on the expert use of specialized equipment for visually inspecting physical luxury products and their associated certificates. This conventional process of authenticating luxury products is expensive, slow, and not easily accessible to consumers. Hence, there is a need for a digital verification approach for luxury products. Blockchain provides the potential for providing traceable and immutable information about a given luxury product. The focus of this paper is to develop a blockchain decentralized application (DApp) for authenticating luxury products in the class of luxury accessories such as jewelry across their respective lifecycles. To achieve this, qualitative analytics is applied to identify useful features for the digital authentication of luxury products. Blockchain requirement engineering modelling is then applied to explore the use of blockchain technologies to realize the features that guarantee transparency in the ownership and use of luxury products. Furthermore, this paper explores the existing blockchain technologies for realizing and implementing the developed requirements of the authentication DApp for luxury products. The selected blockchain technology stack is applied in prototyping authentication systems for luxury products. The implemented platform is simulated to demonstrate the operations carried out in authenticating luxury products. Full article

The present study aims to outline a general overview of the wind energy potential along the Romanian coast of the Black Sea, using the weather data provided by the Maritime Hydrographic Directorate covering a 13-year time interval (2009–2021). The data obtained from seven automatic weather coastal stations distributed along the Romanian perimeter were used to evaluate the wind regime, highlighting the Black Sea’s complex marine environment. The analysis based on the evaluation of the wind parameters per each station registered on the total period revealed that the overall wind characteristics are similar, resulting in no significant variations depending on the station’s location. Moreover, the climatic picture of the Black Sea can be interpreted as two seasons, winter and summer, a conclusion based on the analysis made of the seasonal and monthly variation of the wind aspects. Subsequently, the outcomes obtained in this research imply that the Romanian Black Sea coast has the potential to be a good location for wind energy development due to the strong winds that blow in the region. Full article

Challenging issues arise in the design of control strategies for piezoelectric smart structures. Piezoelectric materials have been investigated for use in distributed parameter systems in order to provide active control efficiently and affordably. In the active control of dynamic systems, distributed sensors and actuators can be created using piezoelectric materials. The three fundamental issues that structural control engineers must face when creating robust control laws are structural modeling methodologies, uncertainty modeling, and robustness validation. These issues are reviewed in this article. A smart structure with piezoelectric (PZT) materials is investigated for its active vibration response under dynamic disturbance. Numerical modeling with finite elements is used to achieve that. The vibration for different model values is presented considering the uncertainty of the modeling. A vibration suppression was achieved with a robust controller and with a reduced order controller. Results are presented for the frequency domain and the state space domain. This work cleary demostrated the advantage of robust control in the vibration suppration of smart stuctures. Full article

Despite the growing demand for improving smile aesthetics and occlusal functionality, a significant percentage of patients still refuse or discontinue orthodontic treatment because of pain and discomfort related to this therapy. As consequence, controlling the pain experienced by patients during the same therapy represents a primary concern for both patients and clinicians. Recent pieces of evidence have suggested that photobiomodulation can reduce pain experienced by patients during the decrowding stage or during specific protocols, for example, rapid maxillary expansion. PBM can be performed with lasers and also with a light-emitting diode (LED) device. Nonetheless, few studies on the latter are still present in the literature. The aim of this research is to evaluate the efficacy of photobiomodulation (PBM) with Laser devices in pain management in fixed orthodontic treatment. Only 14 of all articles met the inclusion and exclusion criteria and were therefore used to conduct the research. The different studies compared, in most cases, patients whose mouths were divided into a part treated with PBM and a placebo part. Most of their results show a statistically significant difference in perceived pain between the irradiated arch and the nonirradiated arch. Three authors did not find statistically significant results in favor of PBM, but they used different laser parameters. To obtain generally valid studies, with consistent and reproducible results, it is necessary to standardize the different laser parameters used. LED is less operator-dependent than laser and PBM using this technology seems to have a biological basis similar to that with lasers. In some studies, its clinical efficacy in pain reduction in some orthodontic therapies has been verified. Finally, this article aims to consider LED technology as a future prospect of research on PBM use in orthodontics. Full article

In this article, experimental results from the testing of four representative scale models of hydro-reactor profiled channels, which create a net head to promote the extraction of hydroelectric power from currents, are presented. The tested scale models include a narrower intermediate channel section of 300 mm diameter. The different profile models studied include an inlet compression chamber and an outlet depression chamber. A net head is created by the difference in pressure, with the head being higher the narrower channel’s zone than in the kinetic head of the outside stream velocity. Because there were no laboratory premises to test the constructed duct model sizes and to easily change the imposed steady current velocity, the experimental tests were performed by dragging the immersed models, attached to a raft in motion, in a place of steady water (the bay of a port). With this methodology, the same effect was obtained, making it possible to perform the testing for several current velocities (velocity of the raft relative to the steady water). Tests on free-flow to compare the difference in kinetic heads were performed. Furthermore, three loads obstructing different percentages of the channel’s narrower section were inserted to analyze the duct channel obstruction limits. The experimental results are validated by numerical results from finite element analysis. Full article

Recent analysis has shown deteriorating traffic conditions in urban areas, caused by an increase in the motorization rate, which has risen to 66.6 vehicles per 100 inhabitants. As a result of the pandemic, individuality has grown, hence private vehicles are becoming more prevalent whilst public transport and sharing are negatively affected. Therefore, European policies have encouraged and innovated more sustainable mobility. Thus, the developed project aims to achieve more efficient mobility and more sustainable environments, towards social and economic well-being. The proposed means of transport aims to appeal to an audience with a reduced ability to drive a car as intended. The IDeS methodology was applied to develop a self-driving, urban micro mobility vehicle, aimed to give enough room and equipment for people with moving disabilities. The innovation of the IDeS method is state-of-the-art and ought to satisfy current product needs, which leads to an innovative micromobility vehicle and portrays a design for a car that will help to close the gaps in urban mobility. These design processes, which are distinguished by the fusion of several industrial techniques, enabled the development of a plan that addresses current mobility issues for disabled people and opens to new mobility prospects. Full article

Hybrid installations with respect to renewable energy sources are becoming more popular due to the stringent requirements for the energy efficiency of buildings. Therefore, the thermomodernization of a district-heating substation was proposed. Several scenarios, including different renewable energies (an air–water heat pump versus a heat pump with photovoltaics), different investment financing (equity or bank credit), and different purposes for heating demand (central heating or central heating with ventilation and domestic hot water), were analyzed. The economic aspects involved the calculations of the payback time and net present value, while the ecological and environmental characteristics were weighed using emission reduction. Each of the analyses resulted in different proposed modernization methods. However, taking both factors together, the computations proved that the most profitable was the scenario with energy demand for heating, domestic hot water, and ventilation purposes financed by means of bank credit with a thermomodernization bonus. Full article

The quality criteria for fairing used to protect antenna devices (AD) of radar stations (RS) from environmental influences are the requirements for ensuring and maintaining strength and protective properties with minimal insertion loss of the transmitted electromagnetic wave (EMW). It is important to assess the influence of manufacturing technology on these parameters, identifying narrow critical zones on the product with minimum strength characteristics and maximum EMW insertion loss. Calculation models of the stress state in a three-layer sandwich are presented with the identification of critical places from a given type of loading. A method for flaw detection of fairings is presented, taking into account the influence of the dynamics of changes in the maximum allowable threshold of EMW losses, which is extremely necessary for analyzing the technological process and correcting strength calculations. Full article

This paper presents a model-based and neural network-based innovative design of single-ended transistor resonant DC/AC converters with zero voltage switching (ZVS). A characteristic of the proposed design method is that the determination of the circuit elements of the converter is performed with an automated procedure, as their values are determined by the output of a previously trained neural network. The use of the proposed method is justified in cases where there is no methodology for the design of the specific power electronic device, or such a methodology exists, but it is either too complex or based on a large number of assumptions. This is usually due to the increasing complexity of power circuits, their possible modes of operation, and the inevitable assumptions and limitations in the analyses and methodologies based on them. In this way, a natural combination of classic design methods and innovative processes is developed based on applied techniques for artificial intelligence. Full article

A previous study proposed an optimal vibration isolator for self-excitation, but the solution results showed a critical drawback for the basement input. Because the plant system is exposed to self-excitation and basement input, the vibration isolator characteristics must meet all the requirements of both excitation cases. Two performance indices of the vibration isolator were introduced to evaluate the vibration control capability over two excitation cases, self-excitation and basement input, using the theoretical linear model of the electric power generator. The compromise strategy was devoted to enhancing the vibration control capability over the basement input, owing to the acceptable margin for self-excitation. The modification of the mechanical properties of the vibration isolator focused on the isolator between the mass block and the surrounding building. Simulation results revealed that an increase in the spring coefficient and a decrease in the damping coefficient of the vibration isolator beneath the mass block could enhance the vibration reduction capability over the basement input. Full article