Applied Sciences

13 pages, 5341 KiB

Open AccessArticle

Effects of Different Fields of View and Rotation Angles on Radiation Doses to Highly Radiosensitive Organs in Children Using Dental Cone Beam Computed Tomography

by Misaki Ito, Ikuho Kojima, Masahiro Iikubo, Shu Onodera, Masahiro Sai, Masaki Fujisawa, Toshiki Kato, Masaaki Nakamura, Masayuki Zuguchi and Koichi Chida

Appl. Sci. 2024, 14(19), 9154; https://doi.org/10.3390/app14199154 - 9 Oct 2024

Viewed by 681

Abstract

Dental cone beam computed tomography (CBCT) is a diverse 3D X-ray imaging technique that has enabled clear visualization of the teeth and surrounding structures. The most common diagnostic purpose of dental CBCT examination in children is ectopic eruption and impacted teeth, and a [...] Read more.

Dental cone beam computed tomography (CBCT) is a diverse 3D X-ray imaging technique that has enabled clear visualization of the teeth and surrounding structures. The most common diagnostic purpose of dental CBCT examination in children is ectopic eruption and impacted teeth, and a small field of view (FOV) is often used. Since it is difficult for children to control their body movements, reducing the rotation angle is effective. However, no studies have examined the effects of different rotation angles on radiation doses to highly radiosensitive organs in children using small FOVs. The purpose of this study was to examine the effects of small FOVs (4 × 4 cm and 6 × 6 cm) and rotation angles (360° and 180°) on doses that highly sensitize organs in children using dental CBCT. The entrance surface doses to lenses, thyroid lobes, parotid glands, and sublingual glands of a pediatric whole-body phantom were measured. By reducing the FOV from 6 × 6 cm to 4 × 4 cm, the dose to the sublingual gland could be significantly decreased. Additionally, by reducing the rotation angle from 360° to 180°, the lens dose can be decreased significantly. As the rate of dose reduction varies among organs, it is important to consider the relative positions of different organs with respect to the FOV and the trajectory of the X-ray tube. Full article

(This article belongs to the Special Issue Advances in Diagnostic and Therapeutic Radiology — 2nd Edition)

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29 pages, 1964 KiB

Open AccessArticle

Assessing Fatality Risks in Maritime Accidents: The Influence of Key Contributing Factors

by Andrea Maternová and Lucia Svabova

Appl. Sci. 2024, 14(19), 9153; https://doi.org/10.3390/app14199153 - 9 Oct 2024

Viewed by 784

Abstract

This paper investigates the factors influencing the probability of fatality in various types of maritime accidents, including grounding, capsizing, sinking, man overboard incidents, and fatal falls, with a focus on several contributing factors—alcohol consumption, meteorological conditions, and visibility. Through comprehensive analysis, the alcohol [...] Read more.

This paper investigates the factors influencing the probability of fatality in various types of maritime accidents, including grounding, capsizing, sinking, man overboard incidents, and fatal falls, with a focus on several contributing factors—alcohol consumption, meteorological conditions, and visibility. Through comprehensive analysis, the alcohol consumption was examined in order to show how it impairs judgment and physical abilities, significantly increasing the risk of fatal outcomes in these accidents. The paper explores the interplay between alcohol consumption and other contributing factors, such as time of day (daytime/night) and weather conditions, providing a comprehensive understanding of how these variables collectively influence fatality rates in EU maritime transportation. The findings underscore the critical need for stringent alcohol regulations and enhanced safety protocols to mitigate the heightened risks associated with alcohol-impaired maritime operations. Full article

(This article belongs to the Section Transportation and Future Mobility)

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17 pages, 3230 KiB

Open AccessArticle

Chemical Composition of Clay Soil Analysis and Potential Health Risks: Experimental Study in Tshwane District, Gauteng Province

by Mohora Feida Malebatja, Moreoagae Bertha Randa, Mathildah Mpata Mokgatle and Oluwafemi Omoniyi Oguntibeju

Appl. Sci. 2024, 14(19), 9152; https://doi.org/10.3390/app14199152 - 9 Oct 2024

Cited by 1 | Viewed by 973

Abstract

The practise of geophagy is common amongst women of childbearing age from different geographic locations, including South Africa, regardless of their social and economic status such as their level of education, race, marital status, income or occupation. This study aimed to examine the [...] Read more.

The practise of geophagy is common amongst women of childbearing age from different geographic locations, including South Africa, regardless of their social and economic status such as their level of education, race, marital status, income or occupation. This study aimed to examine the women of childbearing age in Tshwane District, Gauteng Province, South Africa. An experimental study was conducted at the laboratory to examine the chemical composition of clay soil ingested by geophagic women of childbearing age. Thirty-nine clay soil samples were collected from study participants attending antenatal care services and family planning at public healthcare facilities of Tshwane District, Gauteng Province, and subjected to geochemical analysis. The concentrations of vanadium, manganese, chromium, and barium were detected in quantities exceeding 100 mg/kg in almost all samples. Cadmium, mercury and silver were detected in low concentrations below 1 mg/kg in all samples. The practice of geophagy amongst women of childbearing age has been reported to be associated with detrimental health outcomes and risks such as iron deficiency anaemia, constipation, shortness of breath, maternal and childhood mortalities and morbidities, neurological and central nervous system disorder, death, appendicitis, cancers, teratogenic risks, and ulcers. The chemical composition of clay soil eaten by geophagic women of childbearing age contains potentially harmful substances, thus the practise of geophagy is toxic and should be discouraged to protect public health. Full article

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17 pages, 1237 KiB

Open AccessArticle

Physicochemical Properties and Nutritional Relevance of Rice Beverages Available on the Market

by Katarzyna Najman, Paulina Ponikowska, Anna Sadowska, Ewelina Hallmann, Grażyna Wasiak-Zys, Franciszek Świderski and Krzysztof Buczak

Appl. Sci. 2024, 14(19), 9150; https://doi.org/10.3390/app14199150 - 9 Oct 2024

Viewed by 749

Abstract

Recently, more consumers have reached for plant-based milk substitutes, mainly for health, dietary, and flavour reasons. This study aimed to evaluate the physicochemical and bioactive properties and sensory profile of 10 selected rice drinks available on the EU market. Assessment of the physicochemical [...] Read more.

Recently, more consumers have reached for plant-based milk substitutes, mainly for health, dietary, and flavour reasons. This study aimed to evaluate the physicochemical and bioactive properties and sensory profile of 10 selected rice drinks available on the EU market. Assessment of the physicochemical characteristics included measurement of soluble solids, pH, osmolality, foaming properties and colour parameters. Analysis of bioactive compounds involved the determination of polyphenolic compounds and antioxidant activity. Based on the manufacturer’s data, the composition and nutritional value of the above-mentioned beverages were also analysed in this study. The tested beverages were characterised by a low fat content of 0.6–1.3 g/100 mL, derived mainly from added sunflower oil, but are a good source of energy (energy value of 37–55 kcal/100 mL), derived mainly from naturally occurring carbohydrates whose content ranged from 8.0–11.0 g/100 mL. The protein content of all rice drinks was shallow, not exceeding 0.5 g/100 mL. Of the ten rice drinks analysed, in only two were vitamins B12 and D added (0.38 μg/100 mL and 0.75 μg/100 mL, respectively) and in only three was calcium (120 mg/100 mL) added. In evaluating the physicochemical characteristics, the drinks showed a pH close to neutral (mean 6.85 ± 0.01). The average soluble solids content was about 11%, which was determined by the carbohydrate content. The osmolality of the beverages averaged 324.73 ± 70.17 mOsm/kg H₂O, with four beverages classifiable as hypertonic ones (osmolality > 330 mOsm/kg H₂O), three as isotonic ones (with osmolality between 270–330 mOsm/kg H₂O), and three as hypotonic beverages (osmolality < 270 mOsm/kg H₂O). Only two rice drinks evaluated in this study showed foaming properties. The high whiteness index (81.79 ± 2.55) indicated high white colour saturation of the tested beverages. The rice drinks were characterised by a relatively diverse sensory quality regarding aroma and flavour notes. The overall sensory quality was rated highest for the beverages with the highest sugar content. The tested beverages were characterised by a low content of total polyphenols (average 1.40 ± 0.62 mg GAE/100 mL) and relatively high antioxidant activity (average 418.33 ± 59.65 µM TEAC/100 mL). Based on the research conducted and the analysis of the manufacturer’s data, it can be concluded that the rice drinks studied in this paper can be included in the daily diet, providing a rehydrating beverage that shows free radical-neutralizing properties and provides carbohydrates. At the same time, it should be highlighted that the studied drinks have a low nutritional value and cannot be recommended as milk substitutes due to low protein levels and lack of milk-specific vitamins and minerals. Full article

(This article belongs to the Section Applied Biosciences and Bioengineering)

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11 pages, 1593 KiB

Open AccessReview

Myoepithelioma of the Hand: A Systematic Review

by Guido Bocchino, Giacomo Capece, Silvia Pietramala, Giuseppe Rovere, Lorenzo Rocchi, Pasquale Farsetti, Giulio Maccauro and Camillo Fulchignoni

Appl. Sci. 2024, 14(19), 9149; https://doi.org/10.3390/app14199149 - 9 Oct 2024

Viewed by 564

Abstract

Myoepithelioma is an exceptionally rare tumor, primarily arising in glandular tissues but occasionally found in soft tissues, including the hand. Its occurrence in the hand is particularly uncommon, presenting unique clinical challenges due to the limited number of documented cases and the unusual [...] Read more.

Myoepithelioma is an exceptionally rare tumor, primarily arising in glandular tissues but occasionally found in soft tissues, including the hand. Its occurrence in the hand is particularly uncommon, presenting unique clinical challenges due to the limited number of documented cases and the unusual location. We conducted a literature review in June 2024, with the aim to evaluate the current understanding of hand myoepithelioma, recent diagnostic advances, treatment options, and the diverse presentations of this neoplasm. Articles confirmed that patients present with a painless, slow-growing mass in the hand, often misdiagnosed as more common soft tissue tumors like lipomas or fibromas. Imaging, particularly MRI and ultrasound, aids in assessing the tumor, but definitive diagnosis relies on histopathology, including immunophenotyping. Managing spindle cell myoepithelioma in the hand requires a multidisciplinary approach, with surgical excision being the primary treatment. Achieving clear margins is critical yet challenging due to the hand’s complex anatomy. In some cases, adjuvant therapies such as radiation or chemotherapy may be necessary. The prognosis depends on factors like tumor size, location, and the success of surgical removal, with complete excision typically leading to a favorable outcome. Full article

(This article belongs to the Special Issue Feature Review Papers in Section Applied Biosciences and Bioengineering)

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24 pages, 13013 KiB

Open AccessArticle

Dynamic Modeling and Vibration Characteristic Analysis of Fiber Woven Composite Shaft–Disk Rotor with Weight-Reducing Holes

by Haibiao Zhang, Mengyu Shen, Tao Liu, Zhen Li and Qingshan Wang

Appl. Sci. 2024, 14(19), 9148; https://doi.org/10.3390/app14199148 - 9 Oct 2024

Viewed by 573

Abstract

In order to achieve the goal of a lightweight shaft–disk rotor, this paper applies the fiber woven composite material to the disk structure, and at the same time considers the design of the weight-reducing holes on the porous disk. It introduces the domain [...] Read more.

In order to achieve the goal of a lightweight shaft–disk rotor, this paper applies the fiber woven composite material to the disk structure, and at the same time considers the design of the weight-reducing holes on the porous disk. It introduces the domain decomposition and coordinate mapping technology for this, and then establishes the dynamics model of the fiber woven composite material shaft–disk rotor. The model is based on the differential quadrature finite element method, which is suitable for fiber woven composite rotors with arbitrary complex hole patterns. The validity of the model is verified by comparing the results with the literature, finite element simulation, and experiments, and the mechanism of the influence of the material parameters and pore parameters on the vibration characteristics of the system is investigated, which provides the data support and theoretical basis for the analysis of the dynamics of the fiber woven composite rotor. Full article

(This article belongs to the Special Issue Advanced Materials and Technologies for Aerospace and Mechanical Engineering)

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22 pages, 8486 KiB

Open AccessArticle

Safety Assessment of Gas Pipelines Crossing River through Hydrodynamic Analysis

by Tae Soo Eum, Eun Taek Shin, Jong Pyo Park and Chang Geun Song

Appl. Sci. 2024, 14(19), 9147; https://doi.org/10.3390/app14199147 - 9 Oct 2024

Viewed by 728

Abstract

Gas pipelines are buried and installed across rivers to supply the gas necessary for daily life. When crossing rivers, gas pipelines are typically installed on bridges; however, when installation on bridges is not feasible, the pipelines are buried in riverbeds. This study utilized [...] Read more.

Gas pipelines are buried and installed across rivers to supply the gas necessary for daily life. When crossing rivers, gas pipelines are typically installed on bridges; however, when installation on bridges is not feasible, the pipelines are buried in riverbeds. This study utilized both a one-dimensional model (HEC-RAS) and two-dimensional models (SMS) to simulate river flow and estimate the potential for scour and deposition around buried pipelines. The hydrodynamic simulations considered critical factors, including sediment transport, river discharge, and geological characteristics, to derive the maximum scour depth and assess the risk of pipeline exposure. The findings from the long-term and short-term simulations confirmed that riverbed changes due to natural hydrological events do not exceed the minimum burial depth standards, thereby ensuring pipeline safety. In addition, the study proposed specific reinforcement measures tailored to local site conditions, addressing concerns of continuous subsidence and ensuring long-term structural stability. This research offers important insights into pipeline risk management and contributes to the development of more effective regulatory standards for gas pipelines buried in riverbeds, enhancing both their safety and environmental sustainability Full article

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19 pages, 4480 KiB

Open AccessFeature PaperArticle

Nonlinear Analysis and Closed-Form Solution for Overhead Line Magnetic Energy Harvester Behavior

by Alexander Abramovitz, Moshe Shwartsas and Alon Kuperman

Appl. Sci. 2024, 14(19), 9146; https://doi.org/10.3390/app14199146 - 9 Oct 2024

Viewed by 567

Abstract

Recently, much attention has been given to the development of various energy harvesting technologies to power remote electronic sensors, data loggers, and communicators that can be installed on smart grid systems. Magnetic energy harvesting is, perhaps, the most straightforward way to capture a [...] Read more.

Recently, much attention has been given to the development of various energy harvesting technologies to power remote electronic sensors, data loggers, and communicators that can be installed on smart grid systems. Magnetic energy harvesting is, perhaps, the most straightforward way to capture a significant amount of power from a current-carrying overhead line. Since the harvester is expected to have a small size, the high currents of the distribution system easily saturate its magnetic core. As a result, the operation of the magnetic harvester is highly nonlinear and makes precise analytical modeling difficult. The operation of an overhead line magnetic energy harvester (OLMEH) generating significant DC power output into a constant voltage load was investigated in this paper. The analysis method was based on the Froelich equation to analytically model the nonlinearity of the core’s BH characteristic. The main findings of this piecewise nonlinear analysis include a closed-form solution that accounts for both the core and rectifiers’ nonlinearities and provides an accurate prediction of OLMEH transfer window length, output current, and harvested power. Continuous and discontinuous operational modes are identified and the mode transition boundary is obtained quantitatively. The theoretical investigation was concluded by comparison with a computer simulation and also verified by the experimental results of a laboratory prototype harvester. A good agreement was found. Full article

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13 pages, 6854 KiB

Open AccessArticle

Enhancing Ice Nucleation: The Role of Surface Roughness in Electrofreezing Using Laser Shock Processed Al6061 T6 Electrodes

by E. G. Espinosa-Yañez, G. C. Mondragón-Rodríguez, E. José-Trujillo and D. P. Luis

Appl. Sci. 2024, 14(19), 9145; https://doi.org/10.3390/app14199145 - 9 Oct 2024

Viewed by 645

Abstract

The present study investigates the impact of the electrode surface roughness on the electrofreezing of water. This research focuses on how the electrode microstructure induced by a laser treatment affects the nucleation and growth of ice crystals under controlled electric fields. For this, [...] Read more.

The present study investigates the impact of the electrode surface roughness on the electrofreezing of water. This research focuses on how the electrode microstructure induced by a laser treatment affects the nucleation and growth of ice crystals under controlled electric fields. For this, electrofreezing experiments of deionized water over electrodes with varying surface roughnesses and crystalline textures were conducted. The electrodes of the Al6061 T6 alloy were microstructured via the Laser Shock Processing (LSP) method. For this purpose, the pulse densities during the LSP process were varied (900, 1600, and 2500 pulses/cm²). The increase in pulse density was correlated to the microstructural features and average roughness of the LSP-treated Al6061 alloy. A wave-like microstructure was induced upon the LSP treatment, with roughnesses between 3.5 and 6 µm at the selected pulse densities. The results indicate that electrode roughness significantly influences the electrofreezing process. Rougher electrodes were found to increase the nucleation temperature, suggesting enhanced ice nucleation activity. These findings are attributed to the increased electric field concentration at the asperities of the rough surfaces and the (111) planes of the Al6061 alloy, which may facilitate the alignment of water molecules and the formation of critical ice nuclei. Full article

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19 pages, 2979 KiB

Open AccessArticle

Quantitative Analysis of Ferrate(VI) and Its Degradation Products in Electrochemically Produced Potassium Ferrate for Waste Water Treatment

by Zoltán Homonnay, Sándor Stichleutner, Ernő Kuzmann, Miklós Kuti, Győző G. Láng, Kende Attila Béres, László Trif, Dániel J. Nagy, Gyula Záray and József Lendvai

Appl. Sci. 2024, 14(19), 9144; https://doi.org/10.3390/app14199144 - 9 Oct 2024

Viewed by 619

Abstract

Potassium ferrate(VI) (K₂FeO₄) as a particularly strong oxidant represents an effective and environmentally friendly waste water treatment material. When produced by anodic oxidation in highly alkaline aqueous solution, the K₂FeO₄ product is separated and sealed in [...] Read more.

Potassium ferrate(VI) (K₂FeO₄) as a particularly strong oxidant represents an effective and environmentally friendly waste water treatment material. When produced by anodic oxidation in highly alkaline aqueous solution, the K₂FeO₄ product is separated and sealed in inert plastic bags with the retention of some liquid phase with high pH. This method proved to be excellent for long-term storage at moderately low temperature (5 °C) for industrial applications. It is still imperative to check the ferrate(VI) content of the product whenever it is to be used. Fe-57 Mössbauer spectroscopy is an excellent tool for checking the ratio of ferrate(VI) to the degradation product iron(III) in a sample. For this purpose, normally the spectral areas of the corresponding subspectra are considered; however, this approximation neglects the possible differences in the corresponding Mössbauer–Lamb factors. In this work, we have successfully determined the Mössbauer–Lamb factors for the ferrate(VI) and for the most common iron(III) degradation products observed. We have found superparamagnetic behavior and low-temperature phase transformation for another iron(III) degradation product that made the determination of the Mössbauer–Lamb factors impossible in that case. The identities of a total of three different iron(III) degradation products have been confirmed. Full article

(This article belongs to the Special Issue Synthesis, Characterization and Applications of Metal Oxide Nanoparticles)

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14 pages, 977 KiB

Open AccessArticle

The Effect of Railway Projects Increasing Safety on the Frequency of Occurrences

by Vít Hromádka and Tomáš Funk

Appl. Sci. 2024, 14(19), 9143; https://doi.org/10.3390/app14199143 - 9 Oct 2024

Viewed by 614

Abstract

This contribution is focused on the presentation of individual research results aimed at evaluating the socio-economic impacts associated with increasing the safety and reliability of the railway transport route. The goal of the research is to propose and subsequently verify an original approach [...] Read more.

This contribution is focused on the presentation of individual research results aimed at evaluating the socio-economic impacts associated with increasing the safety and reliability of the railway transport route. The goal of the research is to propose and subsequently verify an original approach for assessing the impact of the implementation of investment projects, including measures aimed at increasing the safety and reliability of railway transport routes, on the resulting number of occurrences that happen on the railway in the Czech Republic. The proposed procedure is based on several key documents. In addition to already existing national methodologies, these are mainly the database of occurrences managed by the Railway Administration of the Czech Republic, including approximately 1000 occurrences for each year of the evaluated period (2009–2018), and information on 33 projects on the railway transport route, where the effects of their implementation on the overall frequency of occurrences are examined events in the subject location. The output of the research is a methodical approach for assessing the impact of the implementation of projects aimed at increasing the safety and reliability of the railway transport route. We perceive the impact on the occurrences from the point of view of the frequency of their occurrence and from the point of view of the socio-economic impacts that are achieved as a result of the implementation of the projects. From the point of view of the frequency of occurrence, a reduction in its value of 4.63% was found. As part of the research, the impact on the occurrence of extraordinary events is also assessed in the context of the scope of the railway transport route, both with regard to the length of the reconstructed track and also with regard to traffic performance. Full article

(This article belongs to the Section Transportation and Future Mobility)

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45 pages, 3370 KiB

Open AccessArticle

Adaptive Cybersecurity Neural Networks: An Evolutionary Approach for Enhanced Attack Detection and Classification

by Ahmad K. Al Hwaitat and Hussam N. Fakhouri

Appl. Sci. 2024, 14(19), 9142; https://doi.org/10.3390/app14199142 - 9 Oct 2024

Viewed by 996

Abstract

The increasing sophistication and frequency of cyber threats necessitate the development of advanced techniques for detecting and mitigating attacks. This paper introduces a novel cybersecurity-focused Multi-Layer Perceptron (MLP) trainer that utilizes evolutionary computation methods, specifically tailored to improve the training process of neural [...] Read more.

The increasing sophistication and frequency of cyber threats necessitate the development of advanced techniques for detecting and mitigating attacks. This paper introduces a novel cybersecurity-focused Multi-Layer Perceptron (MLP) trainer that utilizes evolutionary computation methods, specifically tailored to improve the training process of neural networks in the cybersecurity domain. The proposed trainer dynamically optimizes the MLP’s weights and biases, enhancing its accuracy and robustness in defending against various attack vectors. To evaluate its effectiveness, the trainer was tested on five widely recognized security-related datasets: NSL-KDD, CICIDS2017, UNSW-NB15, Bot-IoT, and CSE-CIC-IDS2018. Its performance was compared with several state-of-the-art optimization algorithms, including Cybersecurity Chimp, CPO, ROA, WOA, MFO, WSO, SHIO, ZOA, DOA, and HHO. The results demonstrated that the proposed trainer consistently outperformed the other algorithms, achieving the lowest Mean Square Error (MSE) and highest classification accuracy across all datasets. Notably, the trainer reached a classification rate of 99.5% on the Bot-IoT dataset and 98.8% on the CSE-CIC-IDS2018 dataset, underscoring its effectiveness in detecting and classifying diverse cyber threats. Full article

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17 pages, 4013 KiB

Open AccessArticle

Risk Prediction Model for Tailings Ponds Based on EEMD-DA-LSTM Model

by Bin Ma, Jingwen Zhou and Chenchen Zhang

Appl. Sci. 2024, 14(19), 9141; https://doi.org/10.3390/app14199141 - 9 Oct 2024

Viewed by 624

Abstract

With the passage of time, the constant changes in relevant factors, and the daily maintenance of tailings ponds, the difficulty of tailings pond safety management is increasing day by day. In order to systematically improve the early warning ability for tailings pond dam [...] Read more.

With the passage of time, the constant changes in relevant factors, and the daily maintenance of tailings ponds, the difficulty of tailings pond safety management is increasing day by day. In order to systematically improve the early warning ability for tailings pond dam break risk, the relationship between and influence of various related dam break risk factors of tailings ponds are utilised and the combination with dual attention is innovatively proposed. The risk prediction model for tailings ponds, EEMD-DA-LSTM, is improved. First, Pearson correlation coefficients are used to analyse the correlation between risk factors of tailings ponds. Then, the EEMD method is used to decompose the nonlinear displacement sequence, and the weights of input features are dynamically adjusted by double attention (DA). Finally, the LSTM network model is constructed to predict the displacement change. Taking valley-type tailings pond WKB-1 and mountainside tailings pond WKB-2 as examples, the dam break risk prediction models for tailings ponds are constructed based on three different models, the prediction results of different models are compared and analysed, and the prediction accuracy of the models is evaluated by three different evaluation criteria. The research results show that the integration of the EEMD-LSTM model with the DA model, that is, the EEMD-DA-LSTM model, has a better prediction effect for the dam break risk of tailings ponds WKB-1 and WKB-2 than other models through experimental verification. Therefore, the EEMD-DA-LSTM model is of great significance for preventing and resolving the safety risks of tailings ponds. It is valuable for practitioners in the mining industry and environmentally sustainable development. Full article

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33 pages, 14086 KiB

Open AccessArticle

Energy-Aware Camera Location Search Algorithm for Increasing Precision of Observation in Automated Manufacturing

by Rongfei Li and Francis F. Assadian

Appl. Sci. 2024, 14(19), 9140; https://doi.org/10.3390/app14199140 - 9 Oct 2024

Viewed by 570

Abstract

Visual servoing technology is well developed and applied in many automated manufacturing tasks, especially in tools’ pose alignment. To access a full global view of tools, most applications adopt an eye-to-hand configuration or an eye-to-hand/eye-in-hand cooperation configuration in an automated manufacturing environment. Most [...] Read more.

Visual servoing technology is well developed and applied in many automated manufacturing tasks, especially in tools’ pose alignment. To access a full global view of tools, most applications adopt an eye-to-hand configuration or an eye-to-hand/eye-in-hand cooperation configuration in an automated manufacturing environment. Most research papers mainly put efforts into developing control and observation architectures in various scenarios, but few have discussed the importance of the camera’s location in the eye-to-hand configuration. In a manufacturing environment, the quality of camera estimations may vary significantly from one observation location to another, as the combined effects of environmental conditions result in different noise levels of a single image shot in different locations. In this paper, we propose an algorithm for the camera’s moving policy so that it explores the camera workspace and searches for the optimal location where the image’s noise level is minimized. Also, this algorithm ensures the camera ends up at a suboptimal (if the optimal one is unreachable) location among the locations already searched with the limited energy available for moving the camera. Unlike a simple brute-force approach, the algorithm enables the camera to explore space more efficiently by adapting the search policy by learning the environment. With the aid of an image-averaging technique, this algorithm, in the use of a solo camera, achieves observation accuracy in eye-to-hand configurations to a desirable extent without filtering out high-frequency information in the original image. An automated manufacturing application was simulated, and the results show the success of this algorithm’s improvement in observation precision with limited energy. Full article

(This article belongs to the Special Issue Applied and Innovative Computational Intelligence Systems: 3rd Edition)

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12 pages, 2097 KiB

Open AccessArticle

Development of a Composite Filament Based on Polypropylene and Garlic Husk Particles for 3D Printing Applications

by Cynthia Graciela Flores-Hernández, Juventino López-Barroso, Claudia Esmeralda Ramos-Galván, Beatriz Adriana Salazar-Cruz, María Yolanda Chávez-Cinco and José Luis Rivera-Armenta

Appl. Sci. 2024, 14(19), 9139; https://doi.org/10.3390/app14199139 - 9 Oct 2024

Viewed by 1090

Abstract

Lignocellulosic waste materials are among the most abundant raw materials on Earth, and they have been widely studied as natural additives in materials, especially for polymer composites, with interesting results when it comes to improving physiochemical properties. The main components of these materials [...] Read more.

Lignocellulosic waste materials are among the most abundant raw materials on Earth, and they have been widely studied as natural additives in materials, especially for polymer composites, with interesting results when it comes to improving physiochemical properties. The main components of these materials are cellulose, hemicellulose, and lignin, as well as small amounts of other polysaccharides, proteins, and other extractives. Several kinds of lignocellulosic materials, mainly fibers, have been evaluated in polymer matrices, and recently, the use of particles has increased due to their high surface area. Garlic is a spice seed that generates a waste husk that does not have applications, and there are no reports of industrial use of this kind of lignocellulosic material. Additive manufacturing, also known as 3D printing, is a polymer processing technique that allows for obtaining complex shapes that are hard to obtain with ordinary techniques. The use of composites based on synthetic polymers and lignocellulosic materials is a growing field of research. In the present work, the elaboration and evaluation of 3D-printed polypropylene–garlic husk particle (PP-GHP) composites are reported. First, the process of obtaining a filament by means of a single extrusion was carried out, using different GHP contents in the composites. Once the filament was obtained, it was taken to a 3D printer to obtain probes that were characterized using differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA) was performed with the aim of evaluating the thermal behavior of the 3D-printed PP-GHP composites. According to the obtained results, the crystallization process and thermal stability of the PP-GHP composites were modified with the presence of GHP compared with pristine PP. Dynamic mechanical analysis (DMA) showed that the addition of GHP decreased the storage modulus of the printed composites and that the Tan δ peak width increased, which was associated with an increase in toughness and a more complex structure of the 3D-printed composites. X-ray diffraction (XRD) showed that the addition of GHP favored the presence of the β-phase of PP in the printed composites. Full article

(This article belongs to the Special Issue Advanced Composites Processing and Manufacturing)

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15 pages, 8083 KiB

Open AccessArticle

Advanced Metamaterial-Integrated Dipole Array Antenna for Enhanced Gain in 5G Millimeter-Wave Bands

by Domin Choi, Md Abu Sufian, Jaemin Lee, Wahaj Abbas Awan, Young Choi and Nam Kim

Appl. Sci. 2024, 14(19), 9138; https://doi.org/10.3390/app14199138 - 9 Oct 2024

Viewed by 962

Abstract

A metamaterial-based non-uniform dipole array antenna is presented for high gain 5G millimeter-wave applications with a wideband characteristic. Initially, a non-uniform dipole array is designed on a 0.202 mm thick Rogers RO4003C substrate, offering a wide operating bandwidth ranging from 23.1 GHz to [...] Read more.

A metamaterial-based non-uniform dipole array antenna is presented for high gain 5G millimeter-wave applications with a wideband characteristic. Initially, a non-uniform dipole array is designed on a 0.202 mm thick Rogers RO4003C substrate, offering a wide operating bandwidth ranging from 23.1 GHz to 44.8 GHz. The dipole array antenna emits unidirectional end-fire radiation with a maximum gain of 8.1 dBi and an average gain of 6.7 dBi. Subsequently, to achieve high gain performance, a 5 × 7 metamaterial structure is designed in the direction of the antenna radiation. The implemented metamaterial structure is optimized for the operating frequency, enhancing the directivity of the antenna radiation and resulting in a gain increment of more than 3 dBi compared to the dipole array alone. The developed metamaterial-integrated dipole array antenna offers an operating bandwidth (S11 < −10 dB) of more than 21 GHz (63.92%), ranging from 23.1 GHz to 44.8 GHz, covering the most commonly used 5G millimeter-wave frequency bands (n257, n258, n259, n260, and n261). Furthermore, the presented antenna yields a stable high gain with a peak gain of 11.21 dBi and a good radiation efficiency of more than 64%. The proposed antenna is an excellent option for millimeter-wave 5G systems due to its overall properties, particularly its high gain and end-fire radiation characteristics, combined with a wide operating bandwidth. Full article

(This article belongs to the Section Electrical, Electronics and Communications Engineering)

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10 pages, 3474 KiB

Open AccessArticle

A Low-Hydroxyl Quartz Glass Prepared by Using a Plasma Heat Source as the Flame and High-Purity Quartz Sand as the Raw Material

by Xinmin Yu, Xiurong Du, Xuefu Song, Yongchang Zhu, Xing Liu, Lisheng Zhou, Xueyi Zhu and Kai Qiu

Appl. Sci. 2024, 14(19), 9137; https://doi.org/10.3390/app14199137 - 9 Oct 2024

Viewed by 701

Abstract

In this paper, a quartz glass with low hydroxyl groups was prepared by combining the advantages of various processes, using a plasma heat source as the flame and high-purity quartz sand as the raw material. The purity of the quartz sand was 99.997%. [...] Read more.

In this paper, a quartz glass with low hydroxyl groups was prepared by combining the advantages of various processes, using a plasma heat source as the flame and high-purity quartz sand as the raw material. The purity of the quartz sand was 99.997%. The number of air bubbles in the quartz glass prepared using high-purity quartz sand was lower. The hardness and tensile strength of the quartz glass were 737.7–767.1 GPa and 6.88–9.64 MPa, respectively. The hydroxyl content of the sample was only 4.11 ppm, and the hydroxyl content of the homogenized quartz glass was reduced to 2.64 ppm, which was an improvement of about 35%. After homogenization, the fictive temperature (T_f) of the quartz glass was determined to be 1253 cm⁻¹, and the variation of the T_f value along the radial direction was reduced, indicating a more homogeneous glass structure. The stress distribution in the quartz glass was significantly improved. These results indicate that the preparation of quartz glass from high-purity quartz sand using a plasma heat source as the flame opens up new avenues for optical applications. Full article

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14 pages, 1695 KiB

Open AccessArticle

Combining Dielectric and Hyperspectral Data for Apple Core Browning Detection

by Hanchi Liu, Jinrong He, Yanxin Shi and Yingzhou Bi

Appl. Sci. 2024, 14(19), 9136; https://doi.org/10.3390/app14199136 - 9 Oct 2024

Viewed by 623

Abstract

Apple core browning not only affects the nutritional quality of apples, but also poses a health risk to consumers. Therefore, there is an urgent need to develop a fast and reliable non-destructive detection method for apple core browning. To deal with the challenges [...] Read more.

Apple core browning not only affects the nutritional quality of apples, but also poses a health risk to consumers. Therefore, there is an urgent need to develop a fast and reliable non-destructive detection method for apple core browning. To deal with the challenges of the long incubation period, strong infectivity, and difficulty in the prevention and control of apple core browning, a novel non-destructive detection method for apple core browning has been developed through combining hyperspectral imaging and dielectric techniques. To reduce the computational complexity of high-dimensional multi-view data, canonical correlation analysis is employed for feature dimensionality reduction. Then, the two low-dimensional vectors extracted from two different sensors are concatenated into one united feature vector; therefore, the information contained in the hyperspectral and dielectric data is fused to improve the detection accuracy of the non-destructive method. At last, five traditional classifiers, such as k-Nearest Neighbors, a support vector machine with radial basis function kernel and polynomial kernel, Decision Tree, and neural network, are trained on the fused feature vectors to discriminate apple core browning. The experimental results on our own constructed dataset have shown that the sensitivity, specificity, and precision of SVM with RBF kernel based on concatenated 70-dimensional feature vectors extracted via canonical correlation analysis reached 99.98%, 99.70%, and 99.70%, respectively, which achieved better results than other models. This study can provide theoretical assurance and technical support for further development of higher accuracy and lower-cost non-destructive detection devices for apple core browning. Full article

(This article belongs to the Section Agricultural Science and Technology)

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14 pages, 3511 KiB

Open AccessArticle

Application of Time-Series Modeling in Forecasting the Doctorate-Level Science and Technology Workforce

by Ho-Yeol Yoon and Hochull Choe

Appl. Sci. 2024, 14(19), 9135; https://doi.org/10.3390/app14199135 - 9 Oct 2024

Viewed by 726

Abstract

The science and technology (S&T) workforce plays a crucial role in social development by promoting technological innovation and economic growth, as well as serving as a key indicator of research and development productivity and measure of innovation capability. Therefore, effective S&T workforce policies [...] Read more.

The science and technology (S&T) workforce plays a crucial role in social development by promoting technological innovation and economic growth, as well as serving as a key indicator of research and development productivity and measure of innovation capability. Therefore, effective S&T workforce policies must be established to enhance national competitiveness. This study proposes a time-series forecasting methodology to predict the scale and structural trends of South Korea’s doctorate-level S&T workforce. Based on earlier research and case data, we applied both the traditional time-series model exponential smoothing and the latest model Prophet, developed by Meta, in this study. Further, public data from South Korea were used to apply the proposed models. To ensure robust model evaluation, we considered multiple metrics. With respect to both forecasting accuracy and sensitivity to data variability, Prophet was found to be the most suitable for predicting the S&T doctorate workforce’s scale. The scenarios derived from the Prophet model can help the government formulate policies based on scientific evidence in the future. Full article

(This article belongs to the Special Issue State-of-the-Art Dynamical Systems)

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11 pages, 1327 KiB

Open AccessArticle

An Effective Method of Aerobic Capacity Development: Combined Training with Maximal Aerobic Speed and Small-Sided Games for Amateur Football Players

by Cansel Arslanoglu, Gurkan Selim Celgin, Erkal Arslanoglu, Nevzat Demirci, Fatih Karakas, Erol Dogan, Erdem Cakaloglu, Fatma Nese Sahin and Hamza Kucuk

Appl. Sci. 2024, 14(19), 9134; https://doi.org/10.3390/app14199134 - 9 Oct 2024

Viewed by 1195

Abstract

This study aimed to investigate the effects of combined training with maximal aerobic speed and small-sided games on football players’ aerobic capacity development. Methods: The football players were divided into three groups as a combined training group (n = 20) (Mean ± SD [...] Read more.

This study aimed to investigate the effects of combined training with maximal aerobic speed and small-sided games on football players’ aerobic capacity development. Methods: The football players were divided into three groups as a combined training group (n = 20) (Mean ± SD age 23.40 ± 2.92 yrs, BMI was 23.67 ± 1.59 kg/m², mass: 74.80 ± 5.46 kg, height: 177.73 ± 4.31 cm), maximal aerobic speed group (n = 20) (Mean ± SD age 23.93 ± 2.46 yrs, BMI was 23.32 ± 1.42 kg/m², mass: 72.66 ± 5.38 kg, height: 176.46 ± 4.99 cm) and regular training group (n = 20) (Mean ± SD age 24.80 ± 5.84 yrs, BMI was 22.87 ± 1.67 kg/m², mass: 73.06 ± 6.74 kg, height: 178.33 ± 7.98 cm). In addition to regular football training, maximal aerobic speed training with small-sided games was applied to the combined training group (CT) and only maximal aerobic speed training was applied to the maximal aerobic speed group (MAS) twice a week for 12 weeks. The normal training group (NT) continued their routine football training programme. All participants applied the Yo-Yo IR1 test in the pre-test and post-test of the study. As a result of normality tests, it was determined that the data showed normal distribution, and the ANOVA test and Tukey’s multiple comparison test were used in the intergroup evaluation. Results: When the Yo-Yo IR1 Test pre-test and post-test results were analysed, maximal aerobic speed training with small-sided games (CT) and maximal aerobic speed (MAS) groups were significantly higher compared to the normal training (NT) group regarding training load, running distance, and VO2max value among the football players (p = 0.001). There was no difference in the normal training group (p > 0.05). As a result, it was determined that combined training with maximal aerobic speed, small-sided games, and only maximal aerobic speed effectively improved football players’ aerobic capacity and general performance. Full article

(This article belongs to the Special Issue Exercise, Fitness, Human Performance and Health)

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24 pages, 4050 KiB

Open AccessArticle

Knowledge-Based Perturbation LaF-CMA-ES for Multimodal Optimization

by Huan Liu, Lijing Qin and Zhao Zhou

Appl. Sci. 2024, 14(19), 9133; https://doi.org/10.3390/app14199133 - 9 Oct 2024

Viewed by 539

Abstract

Multimodal optimization presents a significant challenge in optimization problems due to the existence of multiple attraction basins. Balancing exploration and exploitation is essential for the efficiency of algorithms designed to solve these problems. In this paper, we propose the KbP-LaF-CMAES algorithm to address [...] Read more.

Multimodal optimization presents a significant challenge in optimization problems due to the existence of multiple attraction basins. Balancing exploration and exploitation is essential for the efficiency of algorithms designed to solve these problems. In this paper, we propose the KbP-LaF-CMAES algorithm to address multimodal optimization problems based on the Covariance Matrix Adaptation Evolution Strategy (CMA-ES) framework. The Leaders and Followers (LaF) and Knowledge-based Perturbation (KbP) strategies are the primary components of the KbP-LaF-CMAES algorithm. The LaF strategy is utilized to extensively explore the potential local spaces, where two cooperative populations evolve in synergy. The KbP strategy is employed to enhance exploration capabilities. Improved variants of CMA-ES are used to exploit specific domains containing local optima, thereby potentially identifying the global optimum. Simulation results on the test suite demonstrate that KbP-LaF-CMAES significantly outperforms other meta-heuristic algorithms. Full article

(This article belongs to the Section Computing and Artificial Intelligence)

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26 pages, 16329 KiB

Open AccessArticle

Quadcopters in Smart Agriculture: Applications and Modelling

by Katia Karam, Ali Mansour, Mohamad Khaldi, Benoit Clement and Mohammad Ammad-Uddin

Appl. Sci. 2024, 14(19), 9132; https://doi.org/10.3390/app14199132 - 9 Oct 2024

Viewed by 1839

Abstract

Despite technological growth and worldwide advancements in various fields, the agriculture sector continues to face numerous challenges such as desertification, environmental pollution, resource scarcity, and the excessive use of pesticides and inorganic fertilizers. These unsustainable problems in agricultural field can lead to land [...] Read more.

Despite technological growth and worldwide advancements in various fields, the agriculture sector continues to face numerous challenges such as desertification, environmental pollution, resource scarcity, and the excessive use of pesticides and inorganic fertilizers. These unsustainable problems in agricultural field can lead to land degradation, threaten food security, affect the economy, and put human health at risk. To mitigate these global issues, it is essential for researchers and agricultural professionals to promote advancements in smart agriculture by integrating modern technologies such as Internet of Things (IoT), Unmanned Aerial Vehicles (UAVs), Wireless Sensor Networks (WSNs), and more. Among these technologies, this paper focuses on UAVs, particularly quadcopters, which can assist in each phase of the agricultural cycle and improve productivity, quality, and sustainability. With their diverse capabilities, quadcopters have become the most widely used UAVs in smart agriculture and are frequently utilized by researchers in various projects. To explore the different aspects of quadcopters’ use in smart agriculture, this paper focuses on the following: (a) the unique advantages of quadcopters over other UAVs, including an examination of the quadcopter types particularly used in smart agriculture; (b) various agricultural missions where quadcopters are deployed, with examples highlighting their indispensable role; (c) the modelling of quadcopters, from configurations to the derivation of mathematical equations, to create a well-modelled system that closely represents real-world conditions; and (d) the challenges that must be addressed, along with suggestions for future research to ensure sustainable development. Although the use of UAVs in smart agriculture has been discussed in other papers, to the best of our knowledge, none have specifically examined the most popular among them, “quadcopters”, and their particular use in smart agriculture in terms of types, applications, and modelling techniques. Therefore, this paper provides a comprehensive survey of quadcopters’ use in smart agriculture and offers researchers and engineers valuable insights into this evolving field, presenting a roadmap for future enhancements and developments. Full article

(This article belongs to the Special Issue Aerial Robotics and Vehicles: Control and Mechanical Design)

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29 pages, 11340 KiB

Open AccessArticle

Alternative Solution for Towing Systems Used in the Automotive Industry

by Andrei Victor Petrici, Maria Luminita Scutaru, Vasile Gheorghe and Sorin Vlase

Appl. Sci. 2024, 14(19), 9131; https://doi.org/10.3390/app14199131 - 9 Oct 2024

Viewed by 846

Abstract

This paper aims, in the context of the need to reduce the weight and price of vehicles, to present theoretical and experimental results regarding towing systems made of alternative materials (fibrous composite materials and aluminum alloys). The study of the main element of [...] Read more.

This paper aims, in the context of the need to reduce the weight and price of vehicles, to present theoretical and experimental results regarding towing systems made of alternative materials (fibrous composite materials and aluminum alloys). The study of the main element of the whole system, namely towbar research, was stressed, presenting comparative results. The FEM will be used to obtain the stress and strain field in the towball and the towing system. The experimental tests validate the theoretical results obtained. This paper studies five towing systems made by different materials and finally presents a series of practical recommendations, useful in the industry, regarding the improvement of the analyzed models. Full article

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24 pages, 983 KiB

Open AccessArticle

An Improved Variable Neighborhood Search for the Reconfigurable Assembly Line Reconfiguring Problem

by Xiaojun Zhu, Zhigang Xu, Junyi Wang and Xiao Yang

Appl. Sci. 2024, 14(19), 9130; https://doi.org/10.3390/app14199130 - 9 Oct 2024

Viewed by 564

Abstract

Throughout the past several decades, the manufacturing industry has been confronted with rapidly evolving market demands. The Reconfigurable Assembly Line (RAL) changes the quantity and variety of products produced through reconfiguration at different stages. The reconfiguration stages of RAL include the reallocation of [...] Read more.

Throughout the past several decades, the manufacturing industry has been confronted with rapidly evolving market demands. The Reconfigurable Assembly Line (RAL) changes the quantity and variety of products produced through reconfiguration at different stages. The reconfiguration stages of RAL include the reallocation of operations and resources. However, existing research has neglected the resources. In the paper, a mixed integer linear program for the Reconfigurable Assembly Line Reconfiguring Problem is first formulated. Subsequently, an efficient data structure is developed to model the process precedence constraint and alternative resources. And an improved Variable Neighborhood Search which includes new problem-specific neighborhood structures and local search for resource selection is proposed to solve the problem. Computational results demonstrate the contribution of the proposed data structure and the improved procedure. Furthermore, the experiments verify the superiority and stability of the proposed method compared with other heuristic algorithms. Full article

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14 pages, 3948 KiB

Open AccessArticle

Assessment of the Functional Properties of the Surfaces of Ductile Cast Iron Parts

by Daniel Grochała, Marcin Jasiewicz, Krzysztof Filipowicz, Arkadiusz Parus, Bartosz Powałka, Rafał Grzejda and Paweł Zmarzły

Appl. Sci. 2024, 14(19), 9129; https://doi.org/10.3390/app14199129 - 9 Oct 2024

Viewed by 609

Abstract

Modern technology allows ductile cast iron parts to be efficiently machined while ensuring a relatively long tool life. One of the basic indices describing the susceptibility of ductile cast irons to change in volume, shape, and dimensions under machining conditions is their machinability. [...] Read more.

Modern technology allows ductile cast iron parts to be efficiently machined while ensuring a relatively long tool life. One of the basic indices describing the susceptibility of ductile cast irons to change in volume, shape, and dimensions under machining conditions is their machinability. Machinability can be expressed directly in terms of the values of basic quantities such as periodic cutting speed and roughness. At the same time, machinability is a relative quantity evaluated alternatively. This means that the machinability of ductile cast iron can be good, allowing high cutting speeds to be achieved, but it can also be poor, expressed in terms of poor surface quality. In the experimental research carried out, an attempt was made to determine the limit values of the cutting speed, beyond which one should not exceed, in order to increase the efficiency of the machining process. The surface roughness, unlike the periodic cutting speed, is a quantity defined in the product design documentation, so its limits must be observed. In addition to the usual indices of surface geometric texture, the research analysed alternative indices for determining the condition of surface geometric texture and the influence of periodic cutting speed on their values. In the conclusions, valuable recommendations are given for designers and technologists on the purpose and functionality of product surfaces and how to define them. Methods of specifying tribological characteristics, hydrophobic or hydrophilic properties, as well as the ability to retain fluids and maintain protective coatings of ductile cast iron parts after machining are described, for which relative values, depending on the machining parameters used, can vary from about 10 to even 30%. Full article

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17 pages, 7505 KiB

Open AccessArticle

A Collision Risk Assessment Method for Aircraft on the Apron Based on Petri Nets

by Jingyuan Sun, Xiaowei Tang and Quan Shao

Appl. Sci. 2024, 14(19), 9128; https://doi.org/10.3390/app14199128 - 9 Oct 2024

Viewed by 581

Abstract

The airport apron is a high-risk area for aircraft collisions due to its heavy operational load and high aircraft density. Currently, existing quantitative models for apron collision risk provide limited consideration and classification of risk areas. In response, this paper proposes a Petri [...] Read more.

The airport apron is a high-risk area for aircraft collisions due to its heavy operational load and high aircraft density. Currently, existing quantitative models for apron collision risk provide limited consideration and classification of risk areas. In response, this paper proposes a Petri net-based method for assessing aircraft collision risk. The method predicts the probability of aircraft reaching different areas at different times based on operational data, enabling the calculation of collision risks within the Petri net framework. This approach highlights areas with potential collision risks and provides a classification evaluation. Subsequently, aircraft path re-planning is carried out to reduce collision risks. The model simplifies the complex operations of the apron system, making the calculation process clearer. The results show that, during the mid-phase of aircraft taxiing, there is a significant deviation between the actual and ideal positions of aircraft. Areas with high taxiway occupancy are more prone to collision risks. On peak days, due to relatively high flight volumes, the frequency of collision risks is 14% higher than on regular days, with an average risk increase of 23.3%, and the risks are more concentrated. Therefore, reducing collision risks through path planning becomes more challenging. It is recommended to focus attention on areas with high taxiway occupancy during peak periods and carefully plan routes to ensure apron safety. Full article

(This article belongs to the Section Transportation and Future Mobility)

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14 pages, 6638 KiB

Open AccessArticle

Online Unmanned Ground Vehicle Path Planning Based on Multi-Attribute Intelligent Reinforcement Learning for Mine Search and Rescue

by Shanfan Zhang and Qingshuang Zeng

Appl. Sci. 2024, 14(19), 9127; https://doi.org/10.3390/app14199127 - 9 Oct 2024

Viewed by 713

Abstract

Aiming to improve the efficiency of the online process in path planning, a novel searching method is proposed based on environmental information analysis. Firstly, a search and rescue (SAR) environmental model and an unmanned ground vehicle (UGV) motion model are established according to [...] Read more.

Aiming to improve the efficiency of the online process in path planning, a novel searching method is proposed based on environmental information analysis. Firstly, a search and rescue (SAR) environmental model and an unmanned ground vehicle (UGV) motion model are established according to the characteristics of a mining environment. Secondly, an online search area path-planning method is proposed based on the gray system theory and the reinforcement learning theory to handle multiple constraints. By adopting the multi-attribute intelligent (MAI) gray decision process, the action selection decision can be dynamically adjusted based on the current environment, ensuring the stable convergence of the model. Finally, experimental verification is conducted in different small-scale mine SAR simulation scenarios. The experimental results show that the proposed search planning method can capture the target in the search area with a smoother convergence effect and a shorter path length than other path-planning algorithms. Full article

(This article belongs to the Special Issue Advances in Techniques for Aircraft Guidance and Control)

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21 pages, 2515 KiB

Open AccessArticle

Online Self-Learning-Based Raw Material Proportioning for Rotary Hearth Furnace and Intelligent Batching System Development

by Xianxia Zhang, Lufeng Wang, Shengjie Tang, Chang Zhao and Jun Yao

Appl. Sci. 2024, 14(19), 9126; https://doi.org/10.3390/app14199126 - 9 Oct 2024

Viewed by 635

Abstract

With the increasing awareness of environmental protection, the rotary hearth furnace system has emerged as a key technology that facilitates a win-win situation for both environmental protection and enterprise economic benefits. This is attributed to its high flexibility in raw material utilization, capability [...] Read more.

With the increasing awareness of environmental protection, the rotary hearth furnace system has emerged as a key technology that facilitates a win-win situation for both environmental protection and enterprise economic benefits. This is attributed to its high flexibility in raw material utilization, capability of directly supplying blast furnaces, low energy consumption, and high zinc removal rate. However, the complexity of the raw material proportioning process coupled with the rotary hearth furnace system’s reliance on human labor results in a time-consuming and inefficient process. This paper innovatively introduces an intelligent formula method for proportioning raw materials based on online clustering algorithms and develops an intelligent batching system for rotary hearth furnaces. Firstly, the ingredients of raw materials undergo data preprocessing, which involves using the local outlier factor (LOF) method to detect any abnormal values, using Kalman filtering to smooth the data, and performing one-hot encoding to represent the different kinds of raw materials. Afterwards, the affinity propagation (AP) clustering method is used to evaluate past data on the ingredients of raw materials and their ratios. This analysis aims to extract information based on human experience with ratios and create a library of machine learning formulas. The incremental AP clustering algorithm is utilized to learn new ratio data and continuously update the machine learning formula library. To ensure that the formula meets the actual production performance requirements of the rotary hearth furnace, the machine learning formula is fine-tuned based on expert experience. The integration of machine learning and expert experience demonstrates good flexibility and satisfactory performance in the practical application of intelligent formulas for rotary hearth furnaces. An intelligent batching system is developed and executed at a steel plant in China. It shows an excellent user interface and significantly enhances batching efficiency and product quality. Full article

(This article belongs to the Special Issue Data Analysis and Mining: New Techniques and Applications)

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19 pages, 4586 KiB

Open AccessCommunication

Automated Test Creation Using Large Language Models: A Practical Application

by Stanka Hadzhikoleva, Todor Rachovski, Ivan Ivanov, Emil Hadzhikolev and Georgi Dimitrov

Appl. Sci. 2024, 14(19), 9125; https://doi.org/10.3390/app14199125 - 9 Oct 2024

Viewed by 1046

Abstract

The article presents work on developing a software application for test creation using artificial intelligence and large language models. Its main goal is to optimize the educators’ work by automating the process of test generation and evaluation, with the tests being stored for [...] Read more.

The article presents work on developing a software application for test creation using artificial intelligence and large language models. Its main goal is to optimize the educators’ work by automating the process of test generation and evaluation, with the tests being stored for subsequent analysis and use. The application can generate test questions based on specified criteria such as difficulty level, Bloom’s taxonomy level, question type, style and format, feedback inclusion, and more, thereby providing opportunities to enhance the adaptability and efficiency of the learning process. It is developed on the Google Firebase platform, utilizing the ChatGPT API, and also incorporates cloud computing to ensure scalability and data reliability. Full article

(This article belongs to the Section Computing and Artificial Intelligence)

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24 pages, 4712 KiB

Open AccessArticle

Balancing Efficiency and Accuracy: Enhanced Visual Simultaneous Localization and Mapping Incorporating Principal Direction Features

by Yuelin Yuan, Fei Li, Xiaohui Liu and Jialiang Chen

Appl. Sci. 2024, 14(19), 9124; https://doi.org/10.3390/app14199124 - 9 Oct 2024

Viewed by 715

Abstract

In visual Simultaneous Localization and Mapping (SLAM), operational efficiency and localization accuracy are equally crucial evaluation metrics. We propose an enhanced visual SLAM method to ensure stable localization accuracy while improving system efficiency. It can maintain localization accuracy even after reducing the number [...] Read more.

In visual Simultaneous Localization and Mapping (SLAM), operational efficiency and localization accuracy are equally crucial evaluation metrics. We propose an enhanced visual SLAM method to ensure stable localization accuracy while improving system efficiency. It can maintain localization accuracy even after reducing the number of feature pyramid levels by 50%. Firstly, we innovatively incorporate the principal direction error, which represents the global geometric features of feature points, into the error function for pose estimation, utilizing Pareto optimal solutions to improve the localization accuracy. Secondly, for loop-closure detection, we construct a feature matrix by integrating the grayscale and gradient direction of an image. This matrix is then dimensionally reduced through aggregation, and a multi-layer detection approach is employed to ensure both efficiency and accuracy. Finally, we optimize the feature extraction levels and integrate our method into the visual system to speed up the extraction process and mitigate the impact of the reduced levels. We comprehensively evaluate the proposed method on local and public datasets. Experiments show that the SLAM method maintained high localization accuracy after reducing the tracking time by 24% compared with ORB SLAM3. Additionally, the proposed loop-closure-detection method demonstrated superior computational efficiency and detection accuracy compared to the existing methods. Full article

(This article belongs to the Special Issue Mobile Robotics and Autonomous Intelligent Systems)

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