bluuebunny/crossref_metadata_2025 huggingface dataset:
A Data-Assisted and Inter-Symbol Spectrum Analysis-Based Speed Estimation Method for Radiated Signals from Moving Sources
Authors: Liu Gaohui , Chen Boquan
Published: November 2024

Aiming at the problem of estimating the speed of M-ary Phase Shift Keying (MPSK) communication radiated sources and their carrying platform targets, this paper proposes a data-assisted and inter-symbol spectrum analysis-based speed estimation method for MPSK communication radiated sources. The method first demodulates a signal-carrying message symbol from the received MPSK signal; then segments the signal according to the symbol synchronization information and the symbol period; and then compensates the phase of the symbol waveform corresponding to the message data according to the demodulated message symbol; finally combines the phase-compensated symbol waveform data into a two-dimensional matrix and finds the Doppler frequency of the data at the same sampling moment of different symbols using the vertical Fourier transform to obtain the moving target speed. The speed measurement accuracy and anti-noise performance of the method are analyzed through simulation experiments, and the simulation results show that the speed measurement accuracy of the method is 98.5%.
Exploring Synergy of Denoising and Distillation: Novel Method for Efficient Adversarial Defense
Authors: Hong Inpyo , Lee Sokjoon
Published: November 2024

Escalating advancements in artificial intelligence (AI) has prompted significant security concerns, especially with its increasing commercialization. This necessitates research on safety measures to securely utilize AI models. Existing AI models are vulnerable to adversarial attacks, which are a specific form of assault methodology. Although various countermeasures have been explored, practical defense models are scarce. Current adversarial defense methods suffer from reduced accuracy, increased training time, and incomplete defense against adversarial attacks, indicating performance limitations and a lack of robustness. To address these limitations, we propose a composite defense model, the knowledge Distillation and deNoising Network (DiNo-Net), which integrates knowledge distillation and feature denoising techniques. Furthermore, we analyzed a correlation between the loss surface of adversarial perturbations and denoising techniques. Using DiNo-Net, we confirmed that increasing the temperature during the knowledge distillation process effectively amplifies the loss surface around the ground truth. Consequently, this enables more efficient denoising of the adversarial perturbations. It achieved a defense success rate of 72.7%, which is a remarkable improvement over the 41.0% success rate of models with only denoising defense mechanisms. Furthermore, DiNo-Net reduced the training time and maintained higher accuracy, confirming its efficient defense performance. We hope that this relationship will spur the development of fundamental defense strategies.
A Study of Potential Applications of Student Emotion Recognition in Primary and Secondary Classrooms
Authors: Huang Yimei , Deng Wei , Xu Taojie
Published: November 2024

Emotion recognition is critical to understanding students’ emotional states. However, problems such as crowded classroom environments, changing light, and occlusion often affect the accuracy of recognition. This study proposes an emotion recognition algorithm specifically for classroom environments. Firstly, the study adds the self-made MCC module and the Wise-IoU loss function to make object detection in the YOLOv8 model more accurate and efficient. Compared with the native YOL0v8x, it reduces the parameters by 16% and accelerates the inference speed by 20%. Secondly, in order to address the intricacies of the classroom setting and the specific requirements of the emotion recognition task, a multi-channel emotion recognition network (MultiEmoNet) has been developed. This network fuses skeletal, environmental, and facial information, and introduces a central loss function and an attention module AAM to enhance the feature extraction capability. The experimental results show that MultiEmoNet achieves a classification accuracy of 91.4% on a homemade classroom student emotion dataset, which is a 10% improvement over the single-channel classification algorithm. In addition, this study also demonstrates the dynamic changes in students’ emotions in the classroom through visual analysis, which helps teachers grasp students’ emotional states in real time. This paper validates the potential of multi-channel information-fusion deep learning techniques for classroom teaching analysis and provides new ideas and tools for future improvements to emotion recognition techniques.
Orbital-Based Automatic Multi-Layer Multi-Pass Welding Equipment for Small Assembly Plates
Authors: Cai Yang , Yu Gongzhi , Yu Jikun , Ji Yayue
Published: November 2024

To address the technical challenges, production quality issues, and inefficiencies caused by the heavy reliance on traditional manual processing of small assembly plates in the shipbuilding industry, this paper presents the design and analysis of a track-based automatic welding device. This equipment provides a solution for achieving batch and continuous welding in the field of automatic welding technology. The design section includes the mechanical design of the equipment’s core mechanisms, the design of the operating systems, the development of visual scanning strategies under working conditions, and the formulation of multi-layer and multi-pass welding processes. The analysis section comprises the static analysis of the equipment’s mechanical structure, kinematic analysis of the robotic arm, and inspection analysis of the device. Compared with manual welding, multi-layer and multi-pass welding experiments conducted using the equipment demonstrated stabilized welding quality for small assembly plates. Under the conditions of single plates with different groove positions and gaps, when the gap was 4 mm, processing efficiency increased by 7.35%, and processing time was reduced by 10.2%; when the gap was 5 mm, processing efficiency increased by 10.7%, and processing time decreased by 7.39%. The welding formation rate for the overall processing of single plate panels and web grooves increased by 11.48%, total material consumption decreased by 13.4%, and unit material consumption decreased by 13.5%. For mass production of small assembly plates of the same specifications, processing time was reduced by 16.7%, and there was a 41.4% reduction in costs. The equipment effectively addresses the low level of automation and heavy dependence on traditional manual processing in the shipbuilding industry, contributing to cost reduction and efficiency improvement.
Gamification and Immersive Experiences: A Gamified Approach for Promoting Active Aging
Authors: Nacimiento-García Eduardo , González-González Carina S. , Colombo-Ruano Lorena , Gutiérrez-Vela Francisco L.
Published: November 2024

With the global population of individuals aged 60 and above steadily increasing, the need for effective and realistic solutions to promote healthy aging has become imperative. Leveraging the potential of serious games, gamification, and immersive technologies, this study focuses on developing and implementing a practical and tailored gamified platform to foster active aging in older adults. This platform was designed to incorporate game elements such as points, badges, levels, rankings, achievements, and immersive 360-degree images to provide a realistic and captivating user experience. Six distinct games and challenges have been developed through an extensive and iterative design process, each carefully calibrated to accommodate the aging population’s diverse cognitive abilities and interests. By combining the engagement-enhancing features of gamification with the immersive realism of 360-degree images, our platform offers a gamified and immersive solution for older adults. The gamified experiences are enjoyable and directly target cognitive functions, enhancing memory, attention, and problem-solving skills. The platform’s design has been refined through user feedback and usability testing, ensuring its relevance and effectiveness in real-life scenarios. The outcomes of this research shed light on a practical approach to active aging, emphasizing the importance of incorporating gaming experiences to engage and stimulate older adults. This study provides insights for the design and implementation of future interventions aimed at promoting digital literacy and technological proficiency among older populations, ultimately contributing to their active and fulfilling participation in the digital age.
Optimizing Paste and Mortar Margins (α and β) to Enhance Compressive Strength in Cemented Sand, Gravel and Rock
Authors: Baah Wambley Adomako , Jia Jinsheng , Zheng Cuiying , Wang Yue , Jia Baozhen , Wu Yangfeng
Published: November 2024

A suitable range of paste and mortar margins (α and β) to enhance compressive strength in Rich-Mix cemented sand gravel and rock (CSGR) material for application in CSGRD construction is critical. SL 678-2014 recommends margins > 1, which are specifically designed to fill the voids within the fine and coarse aggregates with paste and mortar, respectively, while allowing some excess for workability. However, the optimum ranges of values after 1 are inadequately determined, often leading to high efforts and time-consuming trial mixes that are not economical. This study evaluates two datasets to identify the optimal ranges of α and β margins for compressive strength development in Rich-Mix CSGR, aiming to achieve the compressive strength class C18020, intended for use as cushion, protective, and seepage control layers in CSGRD. Using Pearson correlations, t-statistics, and p-values, the first dataset (7, 28, 90, and 180 days) showed weak correlations between paste margins and compressive strengths (coefficients 0.172 to 0.418, p-values > 0.05) and negligible relationships for mortar margins (coefficients −0.269 to 0.204, p-values > 0.05), affirming the contribution of other factors in the compressive strength development in CSGR. The second dataset (14, 28, 90, and 180 days) revealed significant positive correlations between paste margins and strengths at 14, 90, and 180 days (coefficients up to 0.850, p-values < 0.05). Mortar margins, however, negatively impacted strength (coefficients −0.544 to −0.628, p-values < 0.05), revealing the need to control the sand ratio. The optimal range of values was 1.05 ≤ α ≤ 1.09 and 1.15 ≤ β ≤ 1.25, with a water–binder ratio of 0.7~1.3, vibrating–compacted value (VC) of 2~8 s, and sand ratio of 18~35%. These findings highlight the significance of precise paste and mortar margin ranges in the compressive strength development of Rich-Mix CSGR.
Analysis of Successful Offensive Patterns in Critical Moments in Men’s EuroBasket 2022 and Women’s 2021
Authors: Vázquez-Estévez Christopher , Paramés-González Adrián , Prieto-Lage Iván , Reguera-López-de-la-Osa Xoana , Álvarez-Rodríguez Mónica , Gutiérrez-Santiago Alfonso
Published: November 2024

The growing trend of analyzing all performance factors involved in a game makes identifying offensive patterns a determining factor in improving tactical performance and decision making during a game. The main objective of this research was to analyze the effectiveness and detect successful patterns on offense at critical moments in the men’s EuroBasket 2022 and women’s EuroBasket 2021. The sample was composed of 509 technical–tactical offensive actions obtained from the last 2 min of the final quarters and overtime from the group stage and final round, whose difference in the final score was equal to or less than five points. For this purpose, observational methodology was employed using LINCE PLUS software through an observational instrument designed ad hoc. Descriptive analysis and chi-square (χ2) tests were performed with SPSS 25, and a pattern analysis (T-Patterns) was performed with Theme 5 software. Statistical significance was set at p < 0.05. The teams that were losing when performing the offense finished a greater number of plays and with greater effectiveness. Fastbreaks seem to be more effective in the closing minutes, a play characterized by a maximum of three passes and by finishing with individual play such as 1 × 1. In turn, actions finished near the hoop by inside players seem to be more effective when the possession is finished before 17 s. The practical implications described in this research will enable coaches to tailor their strategies and training to the critical moments of the game.
Thermoregulation and Soil Moisture Management in Strawberry Cultivation Mulched with Sheep Wool
Authors: Broda Jan , Gawłowski Andrzej , Rom Monika , Kukulski Tomasz , Kobiela-Mendrek Katarzyna
Published: November 2024

The application of wool as mulch in strawberry cultivation was analysed to find a solution for the rational use of wool from mountain sheep. In the plantation, the experimental plots mulched with wool, straw, and bark were appointed. The plots were monitored during the experiment, while the soil temperature and moisture content were measured. The data collected in two-hour intervals were analysed, taking into account air temperature and falls registered in the local meteorological station. Additionally, the progress of mulch biodegradation was tracked. The changes in the wool morphology that occurred by biodegradation were observed during microscopic examinations using the Scanning Electron Microscope (SEM). It was stated that wool mulch plays an essential role in thermoregulation of the soil surface, prevents the overheating of the soil during the summer heat, and protects soil against excessive cooling during cold nights. The wool mulch minimizes the fluctuations between the soil’s day and night temperature. The fluctuations do not exceed 2–3 degrees on hot summer days, which are five times smaller than for the control plot. The wool retains large amounts of rainwater several times its weight. The water is then slowly released, providing the growing plants with a moist environment during a longer rainless period. Moreover, wool is difficult to biodegrade and maintains its properties for a long time, lasting longer than one vegetation season. Compared to straw and bark, the temperature fluctuations recorded for wool are two times smaller, and its effectiveness in water management is considerably better. The beneficial impact of the wool mulch ensuring favourable conditions for strawberry growth was explained by the specific wool structure and its unique properties.
Electrohydrodynamic Propeller as One of the Alternatives to Replace Conventional Propulsion Systems
Authors: Čurma Peter , Lázár Marián , Jasminská Natália , Brestovič Tomáš , Duda Filip , Milenovský Peter
Published: November 2024

In this article, an analysis of issues related to EHD propulsion systems, including their design and the working principle, is presented. The article deals with the advantages and shortcomings that influence their utilisation in the conditions of the Earth’s atmosphere. In the practical section of the article, a set of experiments aimed at elucidating a relationship between the geometry of the capacitor model applied voltage and the induced force is described. An essential task was to verify the functionality of a device and to quantify the efficiency of this type of propeller by applying experimental methods aimed at increasing the functionality.
Anatomical Plausibility in Deformable Image Registration Using Bayesian Optimization for Brain MRI Analysis
Authors: Castaño-Aguirre Mauricio , García Hernán Felipe , Cárdenas-Peña David , Porras-Hurtado Gloria Liliana , Orozco-Gutiérrez Álvaro Ángel
Published: November 2024

Deformable image registration plays a crucial role in medical imaging by aligning anatomical structures across multiple datasets, which is essential for accurate diagnosis and treatment planning. However, existing deep learning-based deformable registration models often face challenges in ensuring anatomical plausibility, leading to unnatural deformations in critical brain structures. This paper proposes a novel framework that uses Bayesian optimization to address these challenges, focusing on registering 3D point clouds that represent brain structures. Our method uses probabilistic modeling to optimize non-rigid transformations, providing smooth and interpretable deformations that align with anatomical constraints. The proposed framework is validated using MRI data from patients diagnosed with hypoxic-ischemic encephalopathy (HIE) due to perinatal asphyxia. These datasets include brain scans taken at multiple time points, enabling the modeling of structural changes over time. By incorporating Bayesian optimization, we enhance the accuracy of the registration process while maintaining anatomical fidelity. Our results demonstrate that the approach provides interpretable, anatomically plausible deformations, outperforming conventional methods in terms of accuracy and reliability. This work offers an improved tool for brain MRI analysis, aiding healthcare professionals in better understanding disease progression and guiding therapeutic interventions.
Unit Cell Optimization of Groove Gap Waveguide for High Bandwidth Microwave Applications
Authors: Tahir Ghiayas , Hassan Arshad , Ali Shawkat , Bermak Amine
Published: November 2024

Recently, groove gap waveguides (GGWs) have shown significant potential in power handling and bandwidth enhancement compared to conventional waveguides. In this research work, we designed and developed an innovative mushroom-unit-cell-based groove gap waveguide (MGGW) that has shown improved bandwidth compared to conventional GGW structures. The dispersion characteristics of the MGGW were analyzed through the eigenmode solver feature of Microwave Studio CST, which showed that the bandwidth was improved by 8% compared to conventional unit cells in the microwave spectrum. To validate our proposed method for the physical dimensions of unit cell structures, we developed an MGGW structure for the S band, which shows similar trends aligning with the simulation results. The measurement results are promising as a reflection coefficient of less than −20 dB was achieved over the entire band for the WR284 Electronic Industries Alliance (EIA) standard waveguide adapter. The proposed MGGW structure with improved bandwidth will open new doors for researchers to develop ultra-wide bandwidth microwave applications, i.e., filters, transmission lines, resonators, attenuators, etc.
The Neurophysiological Effects of Virtual Reality Application and Perspectives of Using for Multitasking Training in Cardiac Surgery Patients: Pilot Study
Authors: Tarasova Irina , Trubnikova Olga , Kukhareva Irina , Kupriyanova Darya , Sosnina Anastasia
Published: November 2024

Background: The use of virtual reality (VR) has great potential for medical research and practice, which can help expand rehabilitation activities. This study aimed to evaluate the acceptability and feasibility of the original protocol VR multitasking cognitive training (CT) in both a healthy group and cardiac surgery patients. Methods: A specialized hardware and software complex was developed and tested on both a group of 25 practically healthy individuals, mean age 22.9 years (SD 2.57), and 25 cardiac surgery patients, mean age 62.2 years (SD 7.35). The participants were instructed to complete one session of multitasking CT within the VR complex. Psychometric testing and EEG studies were conducted. Results: All participants were highly accepting of the intended future use, attitude, and pleasure of the training. The healthy subjects demonstrated a statistically significant improvement in attention and spatial skills after VR (p ˂ 0.05). The EEG data revealed a significant increase in alpha power compared to pre-experiment levels (p ˂ 0.0001). The theta/alpha ratio significantly decreased after the VR multitasking CT as compared to the baseline (p ˂ 0.0001). Conclusions: The data obtained indicate that the original training protocol for multitasking CT using VR is acceptable and easy to use for both healthy individuals and cardiac surgery patients.
An Integrated Lean and Six Sigma Framework for Improving Productivity Performance: A Case Study in a Spanish Chemicals Manufacturer
Authors: Alarcón Francisco J. , Calero Mónica , Martín-Lara María Ángeles , Pérez-Huertas Salvador
Published: November 2024

In the pursuit of operational excellence and enhanced competitiveness, a wide range of industries have turned to methodologies such as Lean and Six Sigma; however, in the chemical sector, their application is very limited. This paper presents a Lean Six Sigma framework to identify and reduce sources of variability occurring in the final product composition of a Spanish SME fertilizer manufacturer. The company faced important challenges related to product variability, adversely affecting overall productivity. A real-life case of the Lean Six Sigma implementation was conducted over two years, and its applicability and ability to improve productivity performance were thoroughly assessed. The proposed framework successfully integrated Lean and Six Sigma methodologies, i.e., process mapping (value stream mapping), root cause analysis (Ishikawa cause–effect diagram), project management (SIPOC and DMAIC), and statistical process control, and demonstrated practical benefits for the case company by identifying the key variables affecting product variability and determining their optimal levels. A substantial 50% reduction in the variability of several products and a 42% reduction in material preparation time were achieved. These reductions resulted in a 40% reduction in costs associated with product losses and a 54% reduction in costs from raw material losses.
Enhancing 3D-Printed Clay Models for Heritage Restoration Through 3D Scanning
Authors: Diz-Mellado Eduardo , Perez-Fenoy Jose , Mudarra-Mata Miguel , Rivera-Gómez Carlos , Galan-Marin Carmen
Published: November 2024

Recent development of methodologies based on digital twins through 3D scanning and 3D printing has increased over the past decade, offering new possibilities in manufacturing, production and scaling of models’ applications. However, there are few examples of the application of model digitization technologies for the restoration of ceramic-built heritage by means of 3D modelling. That is why this research focuses on the application of these advanced methodologies to the recovery of architectural ceramic ornamental objects in heritage buildings. Deteriorated ceramic pieces are selected and scanned during field campaigns using 3D scanning technology in early 20th century heritage sites in Seville (Spain). The aim is to create accurate replicas of these damaged objects by 3D printing with clay using non-invasive techniques. The study stands out for its practical approach and its implications for the conservation of built cultural heritage. The results proved effective for replacing lost or damaged elements in a heritage context. Once the investment in the necessary equipment and technologies has been made, the use of clay as a material for 3D printing not only proves feasible but also offers advantages in terms of cost and time savings for repairs compared to traditional restoration techniques. In the present investigation the production time of similar pieces using 3D printing took 6.3–10.9 h while traditional methods take over a week. The application of these technologies represents an advancement in integrating modern methods into cultural heritage conservation, opening new possibilities for the preservation of history and art worldwide.
Projections of Climate Change Impact on Stream Temperature: A National-Scale Assessment for Poland
Authors: Marcinkowski Paweł
Published: November 2024

This national-scale assessment explores the anticipated impact of climate change on stream temperature in Poland. Utilizing an ensemble of six EURO-CORDEX projections (2006 to 2100) under Representative Concentration Pathways (RCPs) 4.5 and 8.5, the study employs the Soil and Water Assessment Tool (SWAT) to simulate stream temperature regimes. Validation against observed stream temperatures at 369 monitoring points demonstrates the reliability and accuracy of the SWAT model performance. Projected changes in air temperature reveal distinct seasonal variations and emission scenario dependencies. The validated stream temperature model indicates a uniform warming tendency across Poland, emphasizing the widespread nature of climate change impacts on aquatic ecosystems. Results show an increase in country-averaged stream temperature from the baseline (16.1 °C), with a rise of 0.5 °C in the near future (NF) and a further increase by 1 °C in the far future (FF) under RCP4.5. Under RCP8.5, the increase is more pronounced, reaching 1 °C in the NF and a substantial 2.6 °C in the FF. These findings offer essential insights for environmental management, emphasizing the need for adaptive strategies to mitigate adverse effects on freshwater ecosystems. However, as a preliminary study, this work uses a simplified temperature model that does not account for detailed hydrological processes and spatial variability, making it a good starting point for more detailed future research.
Optimising Maintenance Planning and Integrity in Offshore Facilities Using Machine Learning and Design Science: A Predictive Approach
Authors: Rios Marina Polonia , Caiado Rodrigo Goyannes Gusmão , Vignon Yiselis Rodríguez , Corseuil Eduardo Thadeu , Santos Paulo Ivson Netto
Published: November 2024

This research presents an innovative solution to optimise maintenance planning and integrity in offshore facilities, specifically regarding corrosion management. The study introduces a prototype for maintenance planning on offshore oil platforms, developed through the Design Science Research (DSR) methodology. Using a 3D CAD/CAE model, the prototype integrates machine learning models to predict corrosion progression, essential for effective maintenance strategies. Key components include damage assessment, regulatory compliance, asset criticality, and resource optimisation, collectively enabling precise and efficient anti-corrosion plans. Case studies on oil and gas platforms validate the practical application of this methodology, demonstrating reduced costs, lower risks associated with corrosion, and enhanced planning efficiency. Additionally, the research opens pathways for future advancements, such as integrating IoT technologies for real-time data collection and applying deep learning models to improve predictive accuracy. These potential extensions aim to evolve the system into a more adaptable and powerful tool for industrial maintenance, with applicability beyond offshore to other environments, including onshore facilities.
Multi-Objective Edge Node Deployment Method Based on Improved Heuristic Algorithms for Smart Mines
Authors: Yin Zhenyu , Bi Zhiying , Zhang Feiqing
Published: November 2024

As the number of intelligent devices in mining environments increases, the transmission time for large datasets, including equipment status and environmental parameters, also rises. This increase leads to longer response times for service requests, making it difficult to meet the equipment’s real-time requirements. Edge computing effectively addresses the demands for low latency and high performance. However, the deployment of edge nodes can negatively affect overall service performance due to resource limitations and node heterogeneity. In this paper, we propose two node deployment strategies: an improved genetic algorithm (IBGA) for fixed device scenarios and an improved sand cat swarm optimization algorithm (ISCSO) for mobile device scenarios, both accounting for the mobility characteristics of the devices. Additionally, we developed a simulation platform based on a production line system and an intelligent patrol vehicle to evaluate the proposed method’s effectiveness. The experimental results show that the IBGA and ISCSO algorithms effectively reduce task delay and deployment cost. Both deployment methods outperform the benchmark algorithms and offer better service quality assurance.
Engineering and Clinical Study of Surface Geometry of Clear Aligners at the Nanoscale
Authors: Machoy Monika , Samulak Renata , Kulesza Sławomir
Published: November 2024

This paper investigates the evolution of the outer surface geometry of Invisalign®—clear orthodontic aligners—caused by degradation triggered by wearing. The obtained results served to confirm whether or not the aligners could continue to be used once their wear time in the therapeutic procedure had ended, taking both their geometric and mechanical features into account. The measurements were performed using atomic force microscopy which allowed the mapping of nanomechanical properties. The obtained images were then processed to determine statistical and functional surface geometry parameters in accordance with relevant ISO standards. The results revealed that the unrepeatability of the manufacturing process causes the surface shape parameters of new aligners to be irregular; however, these features become gradually consistent for worn samples. On the other hand, properly used aligners may change in two ways: the outer layer flattens and its thickness decreases, and at the same time the Young’s modulus of the material decreases. It follows that the degradation processes may be caused by tribological phenomena (abrasion of contact surfaces) and/or biochemical phenomena (biofilm growth, decomposition of the material under the influence of enzymes in the oral cavity).
Three-Dimensional Air Quality Monitoring and Simulation of Campus Microenvironment Based on UAV Platform
Authors: Liu Zhitong , Huang Jinshan , Huang Junyu , Luo Renbo , Wu Zhuowen
Published: November 2024

This study innovatively employs drones equipped with air quality sensors to collect three-dimensional air quality data in a campus microenvironment. Data are accurately corrected using a BP neural network, and a cubic model is constructed using three-dimensional interpolation. Combining photogrammetry technology, this study analyzes air quality patterns, finding significant differences from macro trends. Construction activities and large electronic experimental equipment significantly increase PM2.5 levels in the air. In rainy weather, the respiration of vegetation is enhanced, leading to higher CO2 concentrations, while water bodies exhibit higher temperatures in rainy weather due to their high specific heat capacity. This research not only provides a new perspective for microenvironment air quality monitoring but also offers a scientific basis for future air quality monitoring and management.
Mathematical Modeling and Optimization of Seed Distribution Uniformity in Planting of Sage Seeds Using a Micro-Granular Applicator
Authors: Turkusay Gulin , Yazgi Arzu
Published: November 2024

The objective of this study was to determine the seed flow characteristics and in-row seed distribution uniformity under different operating conditions to develop mathematical models and to optimize the seed distribution uniformity in the seeding of sage seeds by a micro-granule applicator equipped with a conveyor belt seed-metering unit. In this study, weighing tests were used to determine the seed flow characteristics, while sticky belt tests were used to determine the in-row seed distribution uniformity. While the evaluations of flow uniformity were carried out depending on the coefficient of variation values (CVs), in-row seed distribution uniformity evaluations were carried out using the values of the variation factor (Vf) and goodness criterion (λ). Central Composite Design (CCD) was used as the experimental design. Based on the analysis of data obtained from the experiments, the polynomial functions were developed for Vf and λ values and the models were optimized. The forward speed was determined as 2.14 m s−1, the seed rate was 13.9 kg ha−1, and the seed falling angle was 42.73° for the Vf model, while these values were determined as 2.43 m s−1, 14.7 kg ha−1, and 33.11°, respectively, for the λ model. All these findings reveal that the metering unit equipped with conveyor belt could be used for the seeding of sage seeds successfully. Data and information found in this work would have great potential to be used as a guide for farmers, manufacturers, and scientists who work in such areas.
Bone Integration of Femtosecond Laser-Treated Dental Implants with Nanostructured Surfaces: A Controlled Animal Study
Authors: Do Woo-Seok , Son Keun-Ba-Da , Son Young-Tak , Kim Yong-Gun , Hwang Sung-Min , Hwang Jun-Ho , Lee Jong-Hoon , Kim Hyun-Deok , Lee Kyu-Bok , Lee Jae-Mok
Published: November 2024

Background: The purpose of this study is to compare bone union and soft-tissue healing in titanium implants with sandblasted, large-grit, acid-etched surfaces (SLA group) and femtosecond laser-treated surfaces (FEMTO group) in a rabbit model. Methods: Implants were inserted into rabbit tibiae, and implant stability, soft-tissue healing, and microscopic analyses (micro-CT and biopsy) were conducted. All animals maintained normal weight and health post-surgery. Results: Hemostasis was achieved at the laser incision site on the surgery day, but healing was slower compared to conventional methods. Micro-CT showed no significant differences in new bone formation or inflammatory tissue infiltration between groups. Tissue biopsy revealed slightly higher bone-implant contact in the FEMTO group compared to the SLA group, though not statistically significant. Conclusion: These findings suggest that femtosecond laser surface treatment may provide bone union comparable to or better than SLA treatment, though laser-assisted soft-tissue incisions heal more slowly.
The Shear Behavior of the Curved Interface in Polyurethane-Concrete Composite Structures
Authors: Li Bin , Wang Xiangyang , Wang Yin , Ji Yanting , Wang Jing , Du Xueming , Wang Niannian
Published: November 2024

Polyurethane grouting trenchless technology has been widely applied to the rehabilitation of concealed defects in engineering structures. The interfacial properties between polyurethane and engineering structures are key factors determining the stability of the composite structure. In practical applications, the interface shapes of different engineering structures vary significantly, and the influence of the interface shape on interfacial properties should not be overlooked. This study focuses on engineering structures with curved interfaces, such as pile foundations, pipelines, and tunnels. Direct shear tests were conducted on polyurethane and concrete composite specimens with curved interfaces. A comparative analysis of the shear behavior between curved and planar composite specimens was performed, and the influence of arc diameter and polyurethane density on the shear behavior of curved and planar composite specimens was investigated. Additionally, SEM (Scanning Electron Microscopy) was used to conduct a microscopic examination of the interfaces with different polyurethane densities after failure, and the microscopic shear mechanisms between polyurethane and concrete materials were explored. The results revealed that the shear behavior of curved specimens was significantly higher than that of planar specimens. The shear strengths of curved specimens with diameters of 400 mm, 500 mm, and 700 mm were approximately 1.50, 1.39, and 1.10 times those of planar specimens, respectively. With increasing polyurethane density, the variation trend of shear strength in curved specimens was similar to that of planar specimens. However, significant differences were observed in the shear modulus, peak displacement, and shear residual strength between curved and planar specimens as the polyurethane density varied. Different diameter curved interface specimens exhibited a similar trend of shear strength variation with polyurethane density, gradually decreasing as the curvature diameter increased, and ultimately approaching that of planar specimens.
Evaluation of the Thermal Behavior of Commercial Cold-Pressed Oils Obtained from Apricot and Peach By-Products
Authors: Wirkowska-Wojdyła Magdalena , Ostrowska-Ligęza Ewa , Górska Agata , Brzezińska Rita , Piasecka Iga
Published: November 2024

Fruit kernels are bio-waste in the food industry and can be managed as oil raw materials. The aim of the study was to investigate the stability, oxidation resistance, profile of fatty acids, and their distribution at the triacylglycerol positions of commercially available cold-pressed oils from apricot (A1 and A2) and peach kernels (P1 and P2). Additionally, the melting profiles of the oils were recorded. It was found that the tested oils were a good source of unsaturated fatty acids, especially oleic and linoleic acid. The apricot kernel oils differed significantly regarding the contents of oleic acid and linoleic acid, while the peach kernel oils did not differ in the content of fatty acids. Saturated palmitic and stearic acids mainly occupied the external sn-1,3 positions, while linoleic acid was esterified in the internal position in all the analyzed oils. The occurrence of endothermic peaks at low temperatures was recorded on the melting curves, indicating the presence of triacylglycerol fractions with high proportions of poly- and monounsaturated fatty acids. The apricot kernels of the A1 oil were characterized by the highest oxidative stability measured by the maximum oxidation time at the tested temperatures. The activation energy of the oxidation reaction was at a similar level in all the studied oils. Due to the oils’ characteristics, it is worth considering the use of apricot and peach kernel oils in the food industry.
Coupled Elastic–Plastic Damage Modeling of Rock Based on Irreversible Thermodynamics
Authors: Jin Xin , Ding Yufei , Qiao Keke , Wang Jiamin , Fang Cheng , Hu Ruihan
Published: November 2024

Shale is a common rock in oil and gas extraction, and the study of its nonlinear mechanical behavior is crucial for the development of engineering techniques such as hydraulic fracturing. This paper establishes a new coupled elastic–plastic damage model based on the second law of thermodynamics, the strain equivalence principle, the non-associated flow rule, and the Drucker–Prager yield criterion. This model is used to describe the mechanical behavior of shale before and after peak strength and has been implemented in ABAQUS via UMAT for numerical computation. The model comprehensively considers the quasi-brittle and anisotropic characteristics of shale, as well as the strength degradation caused by damage during both the elastic and plastic phases. A damage yield function has been established as a criterion for damage occurrence, and the constitutive integration algorithm has been derived using a regression mapping algorithm. Compared with experimental data from La Biche shale in Canada, the theoretical model accurately simulated the stress–strain curves and volumetric–axial strain curves of shale under confining pressures of 5 MPa, 25 MPa, and 50 MPa. When compared with experimental data from shale in Western Hubei and Eastern Chongqing, China, the model precisely fitted the stress–strain curves of shale at pressures of 30 MPa, 50 MPa, and 70 MPa, and at bedding angles of 0°, 22.5°, 45°, and 90°. This proves that the model can effectively predict the failure behavior of shale under different confining pressures and bedding angles. Additionally, a sensitivity analysis has been performed on parameters such as the plastic hardening rate b, damage evolution rate Bω, weighting factor r, and damage softening parameter a. This research is expected to provide theoretical support for the efficient extraction technologies of shale oil and gas.
The Influence of Steering Axle Design Parameters and Operational Factors on Tire Steering Resistance Torque
Authors: Mateichyk Vasyl , Soltus Anatolii , Smieszek Miroslaw , Klimov Eduard , Kostian Nataliia , Tarandushka Liudmyla , Marchuk Roman
Published: November 2024

This paper presents the results of the study of the kinematics and dynamics of an elastic steered wheel depending on its state, the kingpin unit design parameters, and the tire characteristics in order to obtain dependencies for calculating the tire steering resistance torque in static state and during movement. It was established that when steering in static state, the locked steered wheel is taken as a complex mechanism, and the tire contact patch is rotated about the kingpin axis–support surface intersection point. When turning the unlocked steered wheel, it was determined that the tire contact patch participates in transport and relative motions. The transport motion center is the projection onto the support surface of the center of rotation of the wheel about the kingpin axis. The relative motion center is within the contact patch and is determined experimentally. For both states of the steered wheel, analytical dependencies were obtained for determining the tire steering resistance torque. The results of the analytical studies were experimentally verified on a bench equipped by components and aggregates of a truck, and included an additional rigid false wheel and a special rim. The false wheel made it possible to experimentally determine the tire contact patch transport motion center, and the special rim—to change the knuckle length in the range of 0.22–0.82 m.
Power Transformer Inrush Current Analysis: Simulation, Measurement and Effects
Authors: Nițu Maria-Cristina , Nicolae Ileana-Diana , Dina Livia-Andreea , Mircea Paul-Mihai
Published: November 2024

Inrush current is still a persistent problem affecting the quality of the power system. This paper presents the theoretical aspects of this transient phenomenon, the simulation of the phenomenon for prediction purposes and its measurement in a test laboratory. In the operation of power transformers, there may also be cases where electrical phenomena affecting the operation of transformers may overlap. When power transformers are in operation, there may also be cases where electrical phenomena affecting their operation overlap. This paper includes a study describing such a situation, where the maximum value of the inrush current is amplified by the fact that the series resonance condition has been met. The intersection of these electrical phenomena resulted in internal and external electrical discharges that led to the overhaul of a 440 MVA transformer; the description of this situation is based on field data. The paper focuses on real information and situations that support the development of a maintenance management schedule based on accurate and up-to-date data. The information presented in this paper will be particularly useful to personnel specializing in power transformer design and/or those monitoring/operating high power transformers in the energy sector, but can also be a teaching aid for students interested in such transient phenomena.
Study on the Minimum Operation Width of Human-Powered Bicycles for Safe and Comfortable Cycling
Authors: Qu Shangwen , Hu Jiangbi , Wang Ronghua , Guan Yanyan , Ma Sen , Zhang Zechao
Published: November 2024

Chinese cities are increasingly developing exclusive bicycle paths to improve the safety and efficiency of bicycle transit. The width of bikeways is a critical factor influencing cyclists’ safety and comfort, with insufficient width identified as a major contributor to bicycle accidents. Therefore, determining the minimum operational width for human-powered bicycles is essential for bikeway design. While some countries’ design manuals consider speed as a factor in determining width, there is a lack of field experiments to validate these specifications from the perspective of cyclists’ safety and comfort. This study addresses this gap by conducting a field experiment to measure cycling workload, which reflects safety and comfort under different widths and cycling speeds. The experiment involved 12 cyclists on a test road, where cycling workload was measured at various preset widths and cycling speeds for a single human-powered cyclist. The results were further validated using conventional lateral distance measurement techniques, which are used in the existing literature to determine the cycling width. The results show that wider bikeway widths lead to a lower cycling workload, enhancing comfort and safety. However, both very high (over 20 km/h) and very low (under 5 km/h) speeds significantly increase cyclists’ workload, which in turn requires a wider path to maintain a safe and comfortable cycling experience. The study found that a minimum width of 0.90 m may be adequate for cyclists traveling at speeds between 10 and 15 km/h, while a width of 1.0 m is sufficient for speeds ranging from 5 km/h to 25 km/h, provided the bicycle width does not exceed 0.62 m. Given that cyclists typically progress from slower to faster speeds, a minimum operational width of 1.0 m is recommended for most cases. This study highlights the importance of considering cyclists’ workload in determining appropriate bikeway widths. It provides valuable insights for designing safer, more comfortable bike paths and reducing bicycle accidents, contributing to the sustainable development of urban cycling infrastructure.
Deep Reinforcement Learning-Assisted Teaching Strategy for Industrial Robot Manipulator
Authors: Simon János , Gogolák László , Sárosi József
Published: November 2024

This paper introduces an innovative algorithm aimed at enhancing robot learning using dynamic trajectory modeling and time-dependent state analysis. By integrating reinforcement learning (RL) and trajectory planning, the proposed approach enhances the robot’s adaptability in diverse environments and tasks. The framework begins with a comprehensive analysis of the robot’s operational space, focusing on Cartesian coordinates and configuration systems. By modeling trajectories and states within these systems, the robot achieves sequential tracking of arbitrary states, facilitating efficient task execution in various scenarios. Experimental results demonstrate the algorithm’s efficacy in manipulation tasks and path planning in dynamic environments. By integrating dynamic trajectory modeling and time-dependent state analysis, the robot’s adaptability and performance improve significantly, enabling precise task execution in complex environments. This research contributes to advancing robot learning methodologies, particularly in human–robot interaction scenarios, promising applications in manufacturing, healthcare, and logistics.
Underwater Acoustic Signal LOFAR Spectrogram Denoising Based on Enhanced Simulation
Authors: He Tianxiang , Feng Sheng , Yang Jie , Yu Kun , Zhou Junlin , Chen Duanbing
Published: November 2024

In complex marine environments, extracting target features from acoustic signal is very difficult, making the targets hard to be recognized. Therefore, it is necessary to perform denoising method on the acoustic signal to highlight the target features. However, training deep learning denoising models requires a large mount of acoustic data with labels and obtaining labels with real measured data is also extremely difficult. In this paper, an enhanced simulation algorithm, which considers integrating features of target line spectrum and ocean environmental noise, is proposed to construct a large-scale training sample set. Additionally, a deep convolutional denoising model is presented, which is first train on simulated data and directly applied to real measured data for denoising, enabling line spectrum to be significantly displayed in the time-frequency spectrogram. The results on simulation experiments and sea trials demonstrate that the proposed method can significantly reduce ocean noise while preserving the characteristics of target line spectrum. Furthermore, the experiments demonstrate that the proposed convolutional denoising model has transferability and generalization, making it suitable for denoising underwater acoustic signal in different marine areas.