Applied Sciences

19 pages, 1081 KiB

Open AccessArticle

Expanding the Psychological Domain of Technological Acceptance: The Use of Smart Wearable Devices in Leisure

by Jie Su, Xiaodong Sun and Junhui Wang

Appl. Sci. 2024, 14(12), 5316; https://0-doi-org.brum.beds.ac.uk/10.3390/app14125316 (registering DOI) - 19 Jun 2024

Abstract

This study introduces a new integrated framework by incorporating the Unified Theory of Acceptance and Use of Technology as the technological acceptance component, combined with satisfaction and perceived risk as the psychological acceptance components. The aim is to explore consumers’ behavioral intentions toward [...] Read more.

This study introduces a new integrated framework by incorporating the Unified Theory of Acceptance and Use of Technology as the technological acceptance component, combined with satisfaction and perceived risk as the psychological acceptance components. The aim is to explore consumers’ behavioral intentions toward smart wearable devices and their expectations for the industry. The findings reveal that all research hypotheses were met as anticipated. Notably, the relatively low influence of Facilitating Conditions within the technological acceptance part and the prominent Perceived Functional Value within the psychological acceptance part highlight consumers’ concerns about the compatibility of smart wearable device ecosystems and their satisfaction with basic functionalities. This conclusion indicates that the market needs to address and improve the challenges posed by multi-brand product ecosystems and that addressing the lack of innovation reduces the emotional connection between products and consumers. Full article

24 pages, 3488 KiB

Open AccessArticle

The Design and Investigation of Hybrid a Microfluidic Micromixer

by Muhammad Waqas, Giedrius Janusas, Vytenis Naginevičius and Arvydas Palevicius

Appl. Sci. 2024, 14(12), 5315; https://0-doi-org.brum.beds.ac.uk/10.3390/app14125315 (registering DOI) - 19 Jun 2024

Abstract

Today, microfluidics has become a revolutionary interdisciplinary topic with considerable attention in a wide range of biotechnology applications. In this research work, a numerical investigation of a microfluidic micromixer is carried out using a hybrid actuation approach with different micropillar shapes and gaps. [...] Read more.

Today, microfluidics has become a revolutionary interdisciplinary topic with considerable attention in a wide range of biotechnology applications. In this research work, a numerical investigation of a microfluidic micromixer is carried out using a hybrid actuation approach with different micropillar shapes and gaps. For this purpose, COMSOL Multiphysics v.5.6. is used with three different physics, such as thermoviscous acoustic physics to solve acoustic governing equations, laminar physics to solve fluid flow governing equations, and diluted transport species to solve mixing governing equations. The simulations were carried out at different Reynolds numbers such as 2, 4, 6, 8, 10, and 12 with an oscillation frequency of 15 kHz. The results were in the form of acoustic characteristics such as acoustic pressure, acoustic velocity, acoustic stream, mixing index, and fluid flow behaviour at various Reynolds numbers. The results revealed that the inclusion of micropillars improved the mixing performance and strength of the acoustic field, resulting in an improvement of the mixing performance compared to the case without micropillars. In addition, the mixing performance is also investigated at different Reynolds numbers, and a higher mixing index is investigated at lower Reynolds numbers. Moreover, it was also investigated that blade-shaped micropillars with 0.150 mm gaps deliver the best results compared to the other cases, and the maximum and minimum values of the mixing index are 0.97 and 0.72, respectively, at Reynolds number 2. The main reason behind this larger mixing index at low Reynolds numbers is due to the inclusion of micropillars that enhance the diffusion rate and contact area, leading to the homogenisation of the heterogeneous fluids in the microchamber. The obtained results can be extremely helpful for the design and modifications of a hybrid microfluidics micromixer. Full article

(This article belongs to the Collection Application of Computational Fluid Dynamics in Mechanical Engineering)

15 pages, 771 KiB

Open AccessArticle

Study of Diagnostic Accuracy: Fundus Photography vs. Optical Coherence Tomography

by Manuel Moriche Carretero, Ana de los Reyes Sánchez Parejo, Clara Martínez Pérez, Remedios Revilla Amores, Ángel Pérez Gómez and Marc Biarnés Pérez

Appl. Sci. 2024, 14(12), 5314; https://0-doi-org.brum.beds.ac.uk/10.3390/app14125314 (registering DOI) - 19 Jun 2024

Abstract

(1) Background: This study aimed to determine the diagnostic accuracy that optical coherence tomography (OCT) can add to fundus photography (FP) in assessing the condition of the retinal posterior pole. (2) Methods: We conducted two blocks of analysis: First, the posterior pole of [...] Read more.

(1) Background: This study aimed to determine the diagnostic accuracy that optical coherence tomography (OCT) can add to fundus photography (FP) in assessing the condition of the retinal posterior pole. (2) Methods: We conducted two blocks of analysis: First, the posterior pole of each eye was examined using an FP non-mydriatic imaging device. Second, OCT was used in addition to FP. After consolidating the specific diagnostic criteria, the assessments were evaluated using two blinded independent investigation groups (by optometrists, and by ophthalmologists who were considered the gold standard). (3) Results: We calculated the diagnostic accuracy of FP compared to OCT and found that they had similar sensitivity. FP had a slightly higher specificity (p-value: 0.01), and OCT had a higher kappa coefficient with 0.50 (95% CI: 0.46–0.55) vs. 0.39 (95% CI: 0.34–0.45) for FP. (4) Conclusions: On the basis that the role of the optometrist in Spain is not to diagnose but to detect lesions and refer patients to an ophthalmologist, the results of this study support the use of OCT, which provided gradable images in almost all examined eyes (97.5%), compared to FP (73.5%). However, optometrists need a detailed and standardized guide in order to conduct evaluations according to the ophthalmologist’s criteria. Full article

14 pages, 2872 KiB

Open AccessArticle

Green Manufacturing of UHPFRC Made with Waste Derived from Scrap Tires and Oil Refineries

by Hassan Abdolpour, Murugan Muthu, Paweł Niewiadomski, Łukasz Sadowski, Łukasz Hojdys, Piotr Krajewski and Arkadiusz Kwiecień

Appl. Sci. 2024, 14(12), 5313; https://0-doi-org.brum.beds.ac.uk/10.3390/app14125313 (registering DOI) - 19 Jun 2024

Abstract

Ultrahigh-performance fiber-reinforced cement-based composite (UHPFRC) made with waste derived from scrap tires and oil refineries was tested in this study. The UHPFRC sample exhibited a maximum compressive strength of about 189 MPa at the end of 28 days. Steel fibers were recovered from [...] Read more.

Ultrahigh-performance fiber-reinforced cement-based composite (UHPFRC) made with waste derived from scrap tires and oil refineries was tested in this study. The UHPFRC sample exhibited a maximum compressive strength of about 189 MPa at the end of 28 days. Steel fibers were recovered from scrap tires and were added up to 3% by volume in the UHPFRC samples. Such additions reduced cement flow by 11% but improved compressive strength by 21%. The equilibrium catalyst particles (ECAT) disposed of by oil refineries were used in amounts of up to 15% by weight as a replacement for cement in such UHPFRC samples. These aluminosilicate materials are spherical in shape and have a porous microstructure, which was found to reduce the cement flow by absorbing more free water onto their surfaces. They also reduced the heat and strength developments at early stages. However, the total cost of the final cement-based mixture and associated CO₂ emissions were reduced by up to 7% and 15% due to the inclusion of the ECAT particles. These findings help to optimize the ECAT and recovered steel fibers in the UHPFRC mix design, and such waste valorization strategies can help achieve the goal of becoming carbon neutral. Full article

(This article belongs to the Special Issue Advances in Building Materials and Concrete, 2nd Edition)

16 pages, 407 KiB

Open AccessArticle

Dynamic Link Metric Selection for Traffic Aggregation and Multipath Transmission in Software-Defined Networks

by Grzegorz Rzym, Zbigniew Duliński and Piotr Chołda

Appl. Sci. 2024, 14(12), 5312; https://0-doi-org.brum.beds.ac.uk/10.3390/app14125312 (registering DOI) - 19 Jun 2024

Abstract

Software-defined networks (SDNs) are expanding their presence beyond laboratories, campus networks, ISPs, and data centre networks, moving into various domains. Although originally designed for campus networks, SDNs face scalability challenges, especially with the use of OpenFlow. Addressing these challenges requires innovative traffic management [...] Read more.

Software-defined networks (SDNs) are expanding their presence beyond laboratories, campus networks, ISPs, and data centre networks, moving into various domains. Although originally designed for campus networks, SDNs face scalability challenges, especially with the use of OpenFlow. Addressing these challenges requires innovative traffic management mechanisms to efficiently handle the growing number of connected devices and the increasing volume of traffic from various types of applications. This article proposes an innovative method for link weight selection that incorporates multipath transmission and flow aggregation in the SDNs. This novel approach improves resource utilization in two key ways. First, it involves the preservation of bandwidth during congestion. Second, it minimizes internal resource usage, as illustrated by a reduction in the number of table entries in switches. Resources undergo optimization through the introduction of a novel mechanism for flow aggregation. This novel mechanism, coupled with multipath transmission, enables adaptive responses to dynamic changes in network conditions. The aggregation process leads to a reduced number of flow entries in the core switches compared to the conventional operation of OpenFlow. The proposed scenarios for link weight allocation allow for a reduction in the number of entries in the core switches by up to 99%. The application of the proposed method also results in an increase of 58% in traffic transmission. Full article

(This article belongs to the Special Issue Communication Networks: From Technology, Methods to Applications)

15 pages, 3200 KiB

Open AccessArticle

Anaerobic Two-Phase Co-Digestion for Renewable Energy Production: Estimating the Effect of Substrate Pretreatment, Hydraulic Retention Time and Participating Microbial Consortia

by Lyudmila Kabaivanova, Venelin Hubenov, Neven Dimitrov and Penka Petrova

Appl. Sci. 2024, 14(12), 5311; https://0-doi-org.brum.beds.ac.uk/10.3390/app14125311 (registering DOI) - 19 Jun 2024

Abstract

Green and sustainable economies have recently become a key issue in long-term growth and well-being. Co-digestion of various waste materials in an eco-friendly way through biogas production has become the preferred method for their utilization and valorization. The possibility of hydrogen and methane [...] Read more.

Green and sustainable economies have recently become a key issue in long-term growth and well-being. Co-digestion of various waste materials in an eco-friendly way through biogas production has become the preferred method for their utilization and valorization. The possibility of hydrogen and methane yield maximization depends on the most suitable alkali reagent for pretreatment of waste lignocellulosic material, which was revealed in batch tests to determine the hydrogen production potential. The mixture for digestion consisted of pretreated wheat straw mixed with waste algal biomass in a ratio of 80:20 (w/w). The maximum hydrogen yield was achieved after applying sodium hydroxide thermoalkaline pretreatment, with a two-fold higher yield than the untreated control. Hydrogen production was stable and methane was not present in the resultant gas. The influence of the hydraulic retention time (HRT) on the maintenance of cascade installation was studied. The maximum daily concentration of hydrogen was achieved at an HRT of 2 days—42.5% H₂—and the maximum concentration of methane was 56.1% at an HRT of 6 days. Accumulation of volatile fatty acids was registered in the first step and their depletion was noted in the second one. The obtained values of the cellulose content demonstrated that it was utilized by up to 2.75% in the methanogenic bioreactor at the end of the process. Metagenomics analyses revealed the bacteria Thermocaproicibacter melissae (44.9%) and Clostridium cellulosi (41.9%) participated in the consortium, accomplishing substrate hydrolysis and acidogenesis in the first stage. Less in abundance were Thermoanaerobacterium butyriciformans, Calorimonas adulescens, Pseudomonas aeruginosa and Anaerocolumna chitinilytica. Methanogenesis was performed by an archaeon closely related to Bathyarchaeota (99.5%) and Methanobacterium formicicum. The most abundant bacterial strains in the methanogenic fermenter were Abyssalbus ytuae (30%), Proteiniphilum acetatigenes (26%) and Ruficoccus amylovorans (13%). Full article

(This article belongs to the Special Issue Resource Utilization of Agricultural Wastes)

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22 pages, 5796 KiB

Open AccessArticle

Methodology for the Detection of Contamination and Gradual Outer Race Faults in Bearings by Fusion of Statistical Vibration–Current Features and SVM Classifier

by Geovanni Díaz-Saldaña, Jonathan Cureño-Osornio, Israel Zamudio-Ramírez, Roque A. Osornio-Ríos, Larisa Dunai, Lilia Sava and Jose A. Antonino-Daviu

Appl. Sci. 2024, 14(12), 5310; https://0-doi-org.brum.beds.ac.uk/10.3390/app14125310 (registering DOI) - 19 Jun 2024

Abstract

Bearings are one of the main components of induction motors, machines widely employed in today’s industries, making their monitoring a primordial task; however, most systems focus on measuring one physical magnitude to detect one kind of fault at a time. This research tackles [...] Read more.

Bearings are one of the main components of induction motors, machines widely employed in today’s industries, making their monitoring a primordial task; however, most systems focus on measuring one physical magnitude to detect one kind of fault at a time. This research tackles the combination of two common faults, grease contamination and outer race damage, as lubricant contamination significantly impacts the life of the bearing and the emergence of other defects; as a contribution, this paper proposes a methodology for the diagnosis of this combination of faults based on a proprietary data acquisition system measuring vibration and current signals, from which time domain statistical and fractal features are computed and then fused using LDA for dimensionality reduction, ending with an SVM model for classification, achieving 97.1% accuracy, correctly diagnosing the combination of the contamination with different severities of the outer race damage, improving the classification results achieved when using vibration and current signals individually by 7.8% and 27.2%, respectively. Full article

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

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9 pages, 1676 KiB

Open AccessCommunication

Oxygen Self-Diffusion in Fluorite High Entropy Oxides

by Alexander Chroneos

Appl. Sci. 2024, 14(12), 5309; https://0-doi-org.brum.beds.ac.uk/10.3390/app14125309 (registering DOI) - 19 Jun 2024

Viewed by 22

Abstract

High-entropy oxides have recently attracted the interest of the community as a way of attuning the properties of oxides to energy applications. Here, we employ molecular dynamics simulations combined with empirical pair potential models to examine the predicted oxygen diffusivity of fluorite-structured high-entropy [...] Read more.

High-entropy oxides have recently attracted the interest of the community as a way of attuning the properties of oxides to energy applications. Here, we employ molecular dynamics simulations combined with empirical pair potential models to examine the predicted oxygen diffusivity of fluorite-structured high-entropy oxides. We show that lower levels of the dopants increase the overall diffusivity of the composition, but not to the levels of diffusion seen in yttria-doped zirconia. We attribute this to an increased resistance of the cation sublattice to the distortion that occurs through any multiple substitutions on the cation sublattice. To conclude, it is calculated that oxygen self-diffusion in high-entropy oxides is suppressed as compared to isostructural ternary oxides. Full article

(This article belongs to the Section Materials Science and Engineering)

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11 pages, 2018 KiB

Open AccessCommunication

Inspection of Semi-Elliptical Defects in a Steel Pipe Using the Metal Magnetic Memory Method

by J. Jesús Villegas-Saucillo, Jose Javier Diaz-Carmona, Juan Prado-Olivares, Monserrat Sofia López-Cornejo, Ernesto A. Elvira-Hernández, Carlos A. Cerón-Álvarez and Agustín L. Herrera-May

Appl. Sci. 2024, 14(12), 5308; https://0-doi-org.brum.beds.ac.uk/10.3390/app14125308 (registering DOI) - 19 Jun 2024

Viewed by 41

Abstract

Ferromagnetic pipes are widely used for fluid transportation in various industries. The failure of these ferromagnetic pipes due to surface defects can generate industrial accidents, economic losses, and environmental pollution. Non-destructive testing techniques are required to detect these surface defects. An alternative is [...] Read more.

Ferromagnetic pipes are widely used for fluid transportation in various industries. The failure of these ferromagnetic pipes due to surface defects can generate industrial accidents, economic losses, and environmental pollution. Non-destructive testing techniques are required to detect these surface defects. An alternative is the metal magnetic memory (MMM) method, which can be employed to detect surface flaws in ferromagnetic structures. Based on this method, we present an analysis of experimental results of the magnetic field variations around five different surface semi-elliptical defects of an ASTM A36 steel pipe. A measurement system of MMM signals is implemented with a rotatory mechanism, a magnetoresistive sensor, a data processing unit, and a control digital unit. The MMM method does not require expensive equipment or special treatment of the ferromagnetic structures. In order to research a potential relationship between the defect sample size and the measured MMM signals, variable defect dimensions are experimentally considered. According to these results, the shape and magnitude of the normal and tangential MMM signals are altered by the superficial semi-elliptical defects. In particular, the maximum and mean tangential components and the maximum and minimum normal components are related to the defect dimensions. The proposed measurement system can be used to study the behavior of magnetic field variations around surface defects of ferromagnetic pipes. This system can be adapted to measure the position and damage level of small defects on the surface of ferromagnetic pipes. Full article

(This article belongs to the Special Issue Advances and Applications of Nondestructive Testing)

15 pages, 967 KiB

Open AccessArticle

Validity and Reliability of New Three-Dimensional Reference Systems for Soft Tissue Analysis Using Non-Ionizing Three-Dimensional Imaging

by Roberto Rongo, Vincenzo D’Antò, Ambrosina Michelotti, Marie A. Cornelis and Paolo M. Cattaneo

Appl. Sci. 2024, 14(12), 5307; https://0-doi-org.brum.beds.ac.uk/10.3390/app14125307 (registering DOI) - 19 Jun 2024

Viewed by 65

Abstract

Background: The aim of this study was to evaluate the accuracy and the repeatability of two reference systems for three-dimensional facial scans (FSs) compared with a reference system based on cone-beam computed tomography (CBCT). Subjects and methods: A total of sixty subjects, thirty [...] Read more.

Background: The aim of this study was to evaluate the accuracy and the repeatability of two reference systems for three-dimensional facial scans (FSs) compared with a reference system based on cone-beam computed tomography (CBCT). Subjects and methods: A total of sixty subjects, thirty growing participants (8–17 years old) and thirty non-growing participants (older than 21 years old), with FSs and full-field-of-view CBCT were included. Two different reference systems on the same FS were constructed. To assess validity, the two reference systems based on FSs were compared with the reference systems built using the CBCT scans. After two weeks, all of the FSs were reassessed to evaluate intra-operator repeatability. Reliability and repeatability were evaluated by means of parametric and non-parametric tests, intra-class correlation, the Dahlberg formula, and Bland–Altman plots (p < 0.05). Results: Both reference systems presented good reliability and showed a small difference with respect to the CBCT-based sagittal plane (Sagittal FS1 = 1.90° ± 0.98°; Sagittal FS2 = 1.80° ± 1.13°; p = 0.232). Between them, the two reference systems showed a small difference in the position of the sagittal plane (Sagittal FS1^Sagittal FS2= 1.39° ± 1.13°). Conclusions: Both reference systems assessed in this study showed good intra-operator repeatability and their use may be suggested as reliable reference systems for FSs. Full article

(This article belongs to the Special Issue New Medicine in Paediatric Dentistry and Orthodontics)

19 pages, 6557 KiB

Open AccessArticle

A Technical-Thematic Civil Protection Exercise in Italy: UAS Fleets-Based Activities Supporting Emergency Response in Seismic Scenarios

by Martina Mandirola, Chiara Casarotti, Umberto Morra di Cella, Andrea Berton, Guglielmo Rossi, Carlo Tacconi Stefanelli, Alessandro Menin and Onofrio Lorusso

Appl. Sci. 2024, 14(12), 5306; https://0-doi-org.brum.beds.ac.uk/10.3390/app14125306 (registering DOI) - 19 Jun 2024

Viewed by 75

Abstract

In October 2023, during the Italian Civil Protection Week, in Eastern Lombardy (Italy) a large technical-thematic seismic exercise called “EXE.Lomb.Est 2023” was organized, with the goal of testing the response of the Regional Civil Protection system for post-earthquake damage assessment activities. Within this [...] Read more.

In October 2023, during the Italian Civil Protection Week, in Eastern Lombardy (Italy) a large technical-thematic seismic exercise called “EXE.Lomb.Est 2023” was organized, with the goal of testing the response of the Regional Civil Protection system for post-earthquake damage assessment activities. Within this context, the use of an unmanned aerial system (UAS), in particular the deployment of multi-rotors UAS teams, has been tested as support for the rapid mapping of a large area involving the simultaneous participation of different Italian institutions with UAS units. Coordinated flight planning design, safety issues, coordination and communication procedures, data management and delivery of the results are some of the main aspects investigated and presented in this work. Full article

(This article belongs to the Special Issue UASs Application in Emergency)

21 pages, 12213 KiB

Open AccessArticle

A 3D Numerical Model to Estimate Lightning Types for PyroCb Thundercloud

by Surajit Das Barman, Rakibuzzaman Shah, Syed Islam and Apurv Kumar

Appl. Sci. 2024, 14(12), 5305; https://0-doi-org.brum.beds.ac.uk/10.3390/app14125305 (registering DOI) - 19 Jun 2024

Viewed by 68

Abstract

Pyrocumulonimbus (pyroCb) thunderclouds, produced from extreme bushfires, can initiate frequent cloud-to-ground (CG) lightning strikes containing extended continuing currents. This, in turn, can ignite new spot fires and inflict massive harm on the environment and infrastructures. This study presents a 3D numerical thundercloud model [...] Read more.

Pyrocumulonimbus (pyroCb) thunderclouds, produced from extreme bushfires, can initiate frequent cloud-to-ground (CG) lightning strikes containing extended continuing currents. This, in turn, can ignite new spot fires and inflict massive harm on the environment and infrastructures. This study presents a 3D numerical thundercloud model for estimating the lightning of different types and its striking zone for the conceptual tripole thundercloud structure which is theorized to produce the lightning phenomenon in pyroCb storms. More emphasis is given to the lower positive charge layer, and the impacts of strong wind shear are also explored to thoroughly examine various electrical parameters including the longitudinal electric field, electric potential, and surface charge density. The simulation outcomes on pyroCb thunderclouds with a tripole structure confirm the presence of negative longitudinal electric field initiation at the cloud’s lower region. This initiation is accompanied by enhancing the lower positive charge region, resulting in an overall positive electric potential increase. Consequently, negative surface charge density appears underneath the pyroCb thundercloud which has the potential to induce positive (+CG) lightning flashes. With wind shear extension of upper charge layers in pyroCb, the lightning initiation potential becomes negative to reduce the absolute field value and would generate negative (−CG) lightning flashes. A subsequent parametric study is carried out considering a positive correlation between aerosol concentration and charge density to investigate the sensitivity of pyroCb electrification under the influence of high aerosol conditions. The suggested model would establish the basis for identifying the potential area impacted by lightning and could also be expanded to analyze the dangerous conditions that may arise in wind energy farms or power substations in times of severe pyroCb events. Full article

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17 pages, 755 KiB

Open AccessArticle

Application of Improved Sliding Mode and Artificial Neural Networks in Robot Control

by Duc-Anh Pham, Jong-Kap Ahn and Seung-Hun Han

Appl. Sci. 2024, 14(12), 5304; https://0-doi-org.brum.beds.ac.uk/10.3390/app14125304 (registering DOI) - 19 Jun 2024

Viewed by 61

Abstract

Mobile robots are autonomous devices capable of self-motion, and are utilized in applications ranging from surveillance and logistics to healthcare services and planetary exploration. Precise trajectory tracking is a crucial component in robotic applications. This study introduces the use of improved sliding surfaces [...] Read more.

Mobile robots are autonomous devices capable of self-motion, and are utilized in applications ranging from surveillance and logistics to healthcare services and planetary exploration. Precise trajectory tracking is a crucial component in robotic applications. This study introduces the use of improved sliding surfaces and artificial neural networks in controlling mobile robots. An enhanced sliding surface, combined with exponential and hyperbolic tangent approach laws, is employed to mitigate chattering phenomena in sliding mode control. Nonlinear components of the sliding control law are estimated using artificial neural networks. The weights of the neural networks are updated online using a gradient descent algorithm. The stability of the system is demonstrated using Lyapunov theory. Simulation results in MATLAB/Simulink R2024a validate the effectiveness of the proposed method, with rise times of 0.071 s, an overshoot of 0.004%, and steady-state errors approaching zero meters. Settling times were 0.0978 s for the x-axis and 0.0902 s for the y-axis, and chattering exhibited low amplitude and frequency. Full article

16 pages, 409 KiB

Open AccessArticle

STOD: Towards Scalable Task-Oriented Dialogue System on MultiWOZ-API

by Hengtong Lu, Caixia Yuan and Xiaojie Wang

Appl. Sci. 2024, 14(12), 5303; https://0-doi-org.brum.beds.ac.uk/10.3390/app14125303 (registering DOI) - 19 Jun 2024

Viewed by 73

Abstract

Task-oriented dialogue systems (TODs) enable users to complete specific goals and are widely used in practice. Although existing models have achieved delightful performance for single-domain dialogues, scalability to new domains is far from well explored. Traditional dialogue systems rely on domain-specific information like [...] Read more.

Task-oriented dialogue systems (TODs) enable users to complete specific goals and are widely used in practice. Although existing models have achieved delightful performance for single-domain dialogues, scalability to new domains is far from well explored. Traditional dialogue systems rely on domain-specific information like dialogue state and database (DB), which limits the scalability of such systems. In this paper, we propose a Scalable Task-Oriented Dialogue modeling framework (STOD). Instead of labeling multiple dialogue components, which have been adopted by previous work, we only predict structured API queries to interact with DB and generate responses based on the complete DB results. Further, we construct a new API-schema-based TOD dataset MultiWOZ-API with API query and DB result annotation based on MultiWOZ 2.1. We then propose MSTOD and CSTOD for multi-domain and cross-domain TOD systems, respectively. We perform extensive qualitative experiments to verify the effectiveness of our proposed framework. We find the following. (1) Scalability across multiple domains: MSTOD achieves 2% improvements than the previous state-of-the-art in the multi-domain TOD. (2) Scalability to new domains: our framework enables satisfying generalization capability to new domains, a significant margin of 10% to existing baselines. Full article

(This article belongs to the Special Issue Natural Language Processing (NLP) and Applications—2nd Edition)

38 pages, 1695 KiB

Open AccessReview

Systematic Review: Anti-Forensic Computer Techniques

by Rafael González Arias, Javier Bermejo Higuera, J. Javier Rainer Granados, Juan Ramón Bermejo Higuera and Juan Antonio Sicilia Montalvo

Appl. Sci. 2024, 14(12), 5302; https://0-doi-org.brum.beds.ac.uk/10.3390/app14125302 (registering DOI) - 19 Jun 2024

Viewed by 104

Abstract

The main purpose of anti-forensic computer techniques, in the broadest sense, is to hinder the investigation of a computer attack by eliminating traces and preventing the collection of data contained in a computer system. Nowadays, cyber-attacks are becoming more and more frequent and [...] Read more.

The main purpose of anti-forensic computer techniques, in the broadest sense, is to hinder the investigation of a computer attack by eliminating traces and preventing the collection of data contained in a computer system. Nowadays, cyber-attacks are becoming more and more frequent and sophisticated, so it is necessary to understand the techniques used by hackers to be able to carry out a correct forensic analysis leading to the identification of the perpetrators. Despite its importance, this is a poorly represented area in the scientific literature. The disparity of the existing works, together with the small number of articles, makes it challenging to find one’s way around the vast world of computer forensics. This article presents a comprehensive review of the existing scientific literature on anti-forensic techniques, mainly DFIR (digital forensics incident response), organizing the studies according to their subject matter and orientation. It also presents key ideas that contribute to the understanding of this field of forensic science and details the shortcomings identified after reviewing the state of the art. Full article

(This article belongs to the Special Issue Data Mining and Machine Learning in Cybersecurity)

22 pages, 798 KiB

Open AccessArticle

AtomGID: An Atomic Gesture Identifier for Qualitative Spatial Reasoning

by Kevin Bouchard and Bruno Bouchard

Appl. Sci. 2024, 14(12), 5301; https://0-doi-org.brum.beds.ac.uk/10.3390/app14125301 (registering DOI) - 19 Jun 2024

Viewed by 95

Abstract

In this paper, we present a novel non-deep-learning-based approach for real-time object tracking and activity recognition within smart homes, aiming to minimize human intervention and dataset requirements. Our method utilizes discreet, easily concealable sensors and passive RFID technology to track objects in real-time, [...] Read more.

In this paper, we present a novel non-deep-learning-based approach for real-time object tracking and activity recognition within smart homes, aiming to minimize human intervention and dataset requirements. Our method utilizes discreet, easily concealable sensors and passive RFID technology to track objects in real-time, enabling precise activity recognition without the need for extensive datasets typically associated with deep learning techniques. Central to our approach is AtomGID, an algorithm tailored to extract highly generalizable spatial features from RFID data. Notably, AtomGID’s adaptability extends beyond RFID to other imprecise tracking technologies like Bluetooth beacons and radars. We validate AtomGID through simulation and real-world RFID data collection within a functioning smart home environment. To enhance recognition accuracy, we employ a clustering adaptation of the flocking algorithm, leveraging previously published Activities of Daily Living (ADLs) data. Our classifier achieves a robust classification rate ranging from 85% to 93%, underscoring the efficacy of our approach in accurately identifying activities. By prioritizing non-deep-learning techniques and harnessing the strengths of passive RFID technology, our method offers a pragmatic and scalable solution for activity recognition in smart homes, significantly reducing dataset dependencies and human intervention requirements. Full article

(This article belongs to the Special Issue Intelligent Systems for Multidisciplinary Applications in Era of Artificial Intelligence)

14 pages, 4361 KiB

Open AccessArticle

An Improved Deviation Coupling Control Method for Speed Synchronization of Multi-Motor Systems

by Ying Mu, Liqun Qi, Mingyuan Sun and Wenbo Han

Appl. Sci. 2024, 14(12), 5300; https://0-doi-org.brum.beds.ac.uk/10.3390/app14125300 (registering DOI) - 19 Jun 2024

Viewed by 104

Abstract

In order to enhance the synchronization of welding robot arms and improve welding quality, this study proposes a fuzzy PID-based improved deviation coupling multi-axis synchronous control method. Firstly, in response to the intricacies inherent in the compensation mechanism of the deviation coupling control [...] Read more.

In order to enhance the synchronization of welding robot arms and improve welding quality, this study proposes a fuzzy PID-based improved deviation coupling multi-axis synchronous control method. Firstly, in response to the intricacies inherent in the compensation mechanism of the deviation coupling control structure and the substantial volume of system computation, the integration of average speed and sub-average speed is proposed to optimize the speed compensator. This integration aims to mitigate speed synchronization errors, minimize synchronization adjustment time, and elevate overall system synchronization performance. Moreover, the fuzzy PID algorithm is employed to design the controller to realize the single-motor adaptive control, leading to improvement in both system stability and dynamic response performance. Finally, a simulation model for six-axis synchronization control and an experimental platform were developed. Both simulation and experimental results demonstrate that the improved deviation coupling control method exhibits superior synchronization performance. The proposed multi-axis synchronous control method effectively heightens the synchronous performance of the six-degrees-of-freedom robotic arm. Full article

(This article belongs to the Special Issue Advanced Control Systems and Applications)

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17 pages, 4935 KiB

Open AccessArticle

The Efficiency of Calcium Oxide on Microbial Self-Healing Activity in Alkali-Activated Slag (AAS)

by Nancy Hammad, Amr El-Nemr and Ibrahim G. Shaaban

Appl. Sci. 2024, 14(12), 5299; https://0-doi-org.brum.beds.ac.uk/10.3390/app14125299 (registering DOI) - 19 Jun 2024

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Abstract

Alkali-activated slag (AAS) materials are one of the most promising sustainable construction composites. These novel materials are highly characterized by their improved mechanical and durability properties. Nevertheless, the high shrinkage rate hinders their full-scale applications. The low Ca/Si ratio, complex hydration process, and [...] Read more.

Alkali-activated slag (AAS) materials are one of the most promising sustainable construction composites. These novel materials are highly characterized by their improved mechanical and durability properties. Nevertheless, the high shrinkage rate hinders their full-scale applications. The low Ca/Si ratio, complex hydration process, and fine pore microstructure are the main causes of the reported shrinkage behavior. This study introduces Bacillus subtilis culture for healing the cracking behavior. The enzymatic action leads to precipitating calcium carbonate crystals that fill AAS cracks and pores. Incorporating calcium oxide has been recommended in multiple studies. The main purpose of adding calcium oxide is to enhance the engineering properties of AAS and provide more calcium ions for the biochemical reactions induced by the added bacteria. However, inconsistent findings about the influence of calcium oxide have been reported. This research provides further insights into the effect of calcium oxide (CaO) on the performance of microbial self-healing efficiency in AAS composite. The results highlight that incorporating calcium oxide as 7% of the binder partial replacement has an impact on the engineering properties of bio-AAS materials. The study recommends correlating the percentage of free calcium ions within the AAS mixture with the microbial activity. Full article

(This article belongs to the Special Issue Analysis and Design for Sustainable and Durable Structural Concrete in Infrastructures)

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18 pages, 10602 KiB

Open AccessArticle

A Novel Dataset for Fabric Defect Detection: Bridging Gaps in Anomaly Detection

by Rui Carrilho, Kailash A. Hambarde and Hugo Proença

Appl. Sci. 2024, 14(12), 5298; https://0-doi-org.brum.beds.ac.uk/10.3390/app14125298 (registering DOI) - 19 Jun 2024

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Abstract

Detecting anomalies in texture has become a significant concern across various industrial processes. One prevalent application of this is in inspecting patterned textures, especially in the domain of fabric defect detection, which is a commonly encountered scenario. This task entails dealing with a [...] Read more.

Detecting anomalies in texture has become a significant concern across various industrial processes. One prevalent application of this is in inspecting patterned textures, especially in the domain of fabric defect detection, which is a commonly encountered scenario. This task entails dealing with a wide array of colours and textile varieties, spanning a broad spectrum of fabrics. Due to the extensive diversity in colours, textures, and defect characteristics, fabric defect detection presents a complex and formidable challenge within the realm of patterned texture inspection. While recent trends have seen a rise in the utilization of deep learning methods for anomaly detection, there still exist notable gaps in this field. In this paper, we introduce a novel dataset comprising a diverse selection of fabrics and defects from a textile company based in Portugal. Our contributions encompass the provision of this unique dataset and the evaluation of state-of-the-art (SOTA) methods’ performance on our dataset. Full article

(This article belongs to the Special Issue AI Horizons: Present Status and Visions for the Next Era)

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18 pages, 2027 KiB

Open AccessArticle

Personalized Daily Hand Movement Training Methods and Effects: A Case Study

by Hua Wei, Kun Chen, Zi-Hao Chen and Ding-Bang Luh

Appl. Sci. 2024, 14(12), 5297; https://0-doi-org.brum.beds.ac.uk/10.3390/app14125297 (registering DOI) - 19 Jun 2024

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Abstract

This study proposes a method for personalized daily hand exercise training to address the lack of personalization in rehabilitation training and its disconnect from daily life. This research aims to evaluate the impact of Happiness Memory Therapy on patients’ hand function through gamified [...] Read more.

This study proposes a method for personalized daily hand exercise training to address the lack of personalization in rehabilitation training and its disconnect from daily life. This research aims to evaluate the impact of Happiness Memory Therapy on patients’ hand function through gamified daily life training. The methodology integrates Happiness Memory Therapy and Positive Mirror Theory to assist in life game design. Patient interviews and empathy are used to gather life experiences, interests, hobbies, and challenges, which are then incorporated into personalized rehabilitation training. The experimental process includes pre- and post-intervention tests to assess changes in subjective well-being (SWLS), happiness (SHS), positive and negative emotions (PANAS), psychological well-being (PWB), and hand function impairment (DASH). The results show that the intervention significantly enhances patients’ subjective well-being, happiness, positive emotions, and reduces negative emotions and hand function impairments. In conclusion, Happiness Memory Therapy and Positive Mirror Theory are effective in developing personalized daily hand exercise training methods and have a significant impact on improving the psychological health and quality of life of stroke patients, offering new ideas and methods for personalized rehabilitation training. Full article

(This article belongs to the Section Biomedical Engineering)

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14 pages, 3259 KiB

Open AccessArticle

Design and Implementation of a Two-Wheeled Self-Balancing Car Using a Fuzzy Kalman Filter

by Yimin Ma, Fanhao Meng and Shuangshuang Xiong

Appl. Sci. 2024, 14(12), 5296; https://0-doi-org.brum.beds.ac.uk/10.3390/app14125296 (registering DOI) - 19 Jun 2024

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Abstract

To improve the upright balancing performance of the two-wheeled self-balancing car, this paper proposes an attitude estimation algorithm based on fuzzy Kalman filtering. Fuzzy logic is used to correct the inclination angle and angular velocity of the two-wheeled self-balancing car, thereby optimizing the [...] Read more.

To improve the upright balancing performance of the two-wheeled self-balancing car, this paper proposes an attitude estimation algorithm based on fuzzy Kalman filtering. Fuzzy logic is used to correct the inclination angle and angular velocity of the two-wheeled self-balancing car, thereby optimizing the state of the Kalman filter and ultimately improving the balancing performance of the car. This paper combines dual closed-loop PID control with the complementary filtering algorithm, Kalman filtering algorithm, and fuzzy Kalman filtering algorithm to conduct experiments on a physical two-wheeled self-balancing car. The experimental results validate the superiority of the fuzzy Kalman filtering algorithm proposed in this paper for improving the upright balancing performance of the two-wheeled self-balancing car. Full article

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

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22 pages, 13173 KiB

Open AccessArticle

Applicability of Digital Image Photogrammetry to Rapid Displacement Measurements of Structures in Restricted-Access and Controlled Areas: Case Study in Korea

by Chang-Hwan Choi, Jung-Geun Han and Gigwon Hong

Appl. Sci. 2024, 14(12), 5295; https://0-doi-org.brum.beds.ac.uk/10.3390/app14125295 (registering DOI) - 19 Jun 2024

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Abstract

Critical facilities are generally located in areas with restricted or controlled access, making it difficult for experts to monitor the structural health of enclosed infrastructures. Hence, a case study was conducted in South Korea to evaluate the applicability of digital image photogrammetry using [...] Read more.

Critical facilities are generally located in areas with restricted or controlled access, making it difficult for experts to monitor the structural health of enclosed infrastructures. Hence, a case study was conducted in South Korea to evaluate the applicability of digital image photogrammetry using commercial imaging devices in order to quickly measure the structural deformations of infrastructures in such areas. The applicability evaluation involved measuring the displacement of mechanically stabilized earth (MSE) walls. In the experiment, the displacement of MSE walls was first measured using the traditional monitoring method and the results were compared with those obtained via digital image photogrammetry using commercial imaging devices such as digital cameras and cellphones. The measurement results obtained with the cellphone camera had a maximum error of approximately 20 mm when compared with the results of the traditional monitoring method. Because this is a significant error, even when considering the mechanical error in the traditional monitoring method’s result, it was determined that monitoring using a cellphone camera is infeasible. However, the experimental results of digital image photogrammetry using a digital camera showed a maximum error of approximately 9 mm. Although this is a sizable error, the method was assessed to be technically feasible. Full article

(This article belongs to the Special Issue New Trends of Digital Technology Application in Geotechnical Engineering)

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27 pages, 5204 KiB

Open AccessArticle

AraFast: Developing and Evaluating a Comprehensive Modern Standard Arabic Corpus for Enhanced Natural Language Processing

by Asmaa Alrayzah, Fawaz Alsolami and Mostafa Saleh

Appl. Sci. 2024, 14(12), 5294; https://0-doi-org.brum.beds.ac.uk/10.3390/app14125294 (registering DOI) - 19 Jun 2024

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Abstract

The research presented in the following paper focuses on the effectiveness of a modern standard Arabic corpus, AraFast, in training transformer models for natural language processing tasks, particularly in Arabic. In the study described herein, four experiments were conducted to evaluate the use [...] Read more.

The research presented in the following paper focuses on the effectiveness of a modern standard Arabic corpus, AraFast, in training transformer models for natural language processing tasks, particularly in Arabic. In the study described herein, four experiments were conducted to evaluate the use of AraFast across different configurations: segmented, unsegmented, and mini versions. The main outcomes of the present study are as follows: Transformer models trained with larger and cleaner versions of AraFast, especially in question-answering, indicate the impact of corpus quality and size on model efficacy. Secondly, a dramatic reduction in training loss was observed with the mini version of AraFast, underscoring the importance of optimizing corpus size for effective training. Moreover, the segmented text format led to a decrease in training loss, highlighting segmentation as a beneficial strategy in Arabic NLP. In addition, using the study findings, challenges in managing noisy data derived from web sources are identified, which were found to significantly hinder model performance. These findings collectively demonstrate the critical role of well-prepared, segmented, and clean corpora in advancing Arabic NLP capabilities. The insights from AraFast’s application can guide the development of more efficient NLP models and suggest directions for future research in enhancing Arabic language processing tools. Full article

(This article belongs to the Special Issue Natural Language Processing: Theory, Methods and Applications)

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14 pages, 2083 KiB

Open AccessArticle

Feasibility of Using Reclaimed Water from the Alegria Wastewater Treatment Plant in Concrete Mixing Plants in Rio de Janeiro, Brazil

by Luis Carlos Soares da Silva Junior and Marcelo Obraczka

Appl. Sci. 2024, 14(12), 5293; https://0-doi-org.brum.beds.ac.uk/10.3390/app14125293 (registering DOI) - 19 Jun 2024

Viewed by 118

Abstract

Due to the rising costs of transportation and the more advanced treatment needed to meet the water demands of the urban population, the costs of potable water tend to increase as cities expand. For some water uses, potable water is not required, such [...] Read more.

Due to the rising costs of transportation and the more advanced treatment needed to meet the water demands of the urban population, the costs of potable water tend to increase as cities expand. For some water uses, potable water is not required, such as concrete mixing industries. Previous studies have proven the viability of using reused water in concrete production. In Caju, Rio de Janeiro, four large concrete mixing plants (CMPs) are located close to the Alegria Wastewater Treatment Plant. This study focused on assessing the technical and financial feasibility of reusing these effluents as an alternative source of water for the four CMPs. The alternatives were potable and reused water via two supply methods, water tank trucks and pipelines. All costs were analyzed and projected into the future with the market cost of capital. After comparing the costs, the use of reclaimed water proved to be highly feasible, especially when a using pipeline to supply the CMPs. The present costs for the reclaimed water supply were calculated to be USD 0.99 per m³ for the pipeline alternative and the other alternatives varied in being 5 to 7 times more costly. This water reuse project using pipelines to transport reclaimed water to concrete mixing plants provides a feasible, sustainable alternative water supply in water stressed regions such as Rio de Janeiro. Full article

(This article belongs to the Special Issue New Approaches to Water Treatment: Challenges and Trends)

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15 pages, 3492 KiB

Open AccessArticle

Real-Time Method and Implementation of Head-Wave Extraction for Ultrasonic Imaging While Drilling

by Liangchen Zhang, Junqiang Lu, Jinping Wu, Baiyong Men, Chao Xie, Yanbo Zong, Shubo Yang and Weining Ni

Appl. Sci. 2024, 14(12), 5292; https://0-doi-org.brum.beds.ac.uk/10.3390/app14125292 (registering DOI) - 19 Jun 2024

Viewed by 97

Abstract

Extracting head waves and subsequently uploading their results from the downhole to the surface system in real time could improve the real-time guidance of ultrasonic imaging logging while drilling (UILWD) for drilling operations. To realize the downhole real-time extraction of head waves in [...] Read more.

Extracting head waves and subsequently uploading their results from the downhole to the surface system in real time could improve the real-time guidance of ultrasonic imaging logging while drilling (UILWD) for drilling operations. To realize the downhole real-time extraction of head waves in this logging, three aspects were explored in this study. First, an improved energy ratio head-wave arrival extraction algorithm based on the weighting coefficients and characteristic functions, along with an amplitude detection method relying on peak-to-peak values, was proposed. Second, an echo reception pre-processing analog circuit and a digital signal processing circuit based on FPGA were designed. A pipeline algorithm was developed in FPGA to extract the arrival time and amplitude of the head wave. Finally, software simulations, laboratory tests, and field experiments related to this method were conducted. Our results showed that the real-time head-wave extraction method demonstrated a strong anti-noise ability in real time. The maximum relative error of the arrival time was less than 5%. The relative error of the amplitude was acceptable, and 90% of this value was within 5%. Through the measurement, the time of processing a single-channel waveform by a downhole algorithm was less than 15 ms, thus meeting the requirements for the real-time processing of downholes. Full article

(This article belongs to the Topic Petroleum and Gas Engineering)

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15 pages, 20788 KiB

Open AccessArticle

Pressure-Reducing Design of 3D-Printed Diabetic Shoe Midsole Utilizing Auxetic Lattice Structure

by Jifa Zhang, Shizhu Lu, Yinyin Lin, Yang Wang, Xiaolie Yi and Wencheng Fang

Appl. Sci. 2024, 14(12), 5291; https://0-doi-org.brum.beds.ac.uk/10.3390/app14125291 (registering DOI) - 19 Jun 2024

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Abstract

With the global rise in the prevalence of diabetes, diabetic patients need innovative footwear designs to reduce the risk of foot ulcers. This study examined the mechanical properties of diabetic shoe midsoles featuring auxetic lattice structures. Through the construction of finite element models [...] Read more.

With the global rise in the prevalence of diabetes, diabetic patients need innovative footwear designs to reduce the risk of foot ulcers. This study examined the mechanical properties of diabetic shoe midsoles featuring auxetic lattice structures. Through the construction of finite element models and simulation, this research compared the biomechanical parameter differences in the plantar regions of the metatarsal head, midfoot, and hindfoot when wearing two types of auxetic midsoles with internal angles of 60° and 75° and a non-auxetic midsole with an internal angle of 90° under both walking and running conditions. Compared to the non-auxetic midsole, the auxetic midsoles significantly reduced the peak plantar pressure and optimized the pressure distribution across various plantar regions. Notably, the auxetic 60° midsole reduced the peak plantar pressure by 19.68–55.25% and 16.19–54.39% compared to the non-auxetic 90° midsole during walking and running, respectively. This study also verified that the auxetic midsoles exhibited greater adaptability and compliance to the plantar foot shape, contributing to reductions in plantar pressure in comparisons of deformation values and plantar contact areas across the different midsoles. Auxetic midsoles manufactured using 3D printing technology have significant potential to prevent diabetic foot ulcers and maintain human foot health. This research integrates insights and techniques from materials science and ergonomics, offering a new direction for footwear design. Full article

(This article belongs to the Section Additive Manufacturing Technologies)

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12 pages, 4134 KiB

Open AccessArticle

Characteristics Comparison and Case Study of Traditional Anti-Slip Saddles and Innovative Rolling Saddles in Highway Long-Span Bridges

by Jun Wan, Gang Liu and Zhendong Qian

Appl. Sci. 2024, 14(12), 5290; https://0-doi-org.brum.beds.ac.uk/10.3390/app14125290 (registering DOI) - 19 Jun 2024

Viewed by 112

Abstract

The cable saddle structure is the main support component for long-span bridges to transmit cable force, which is of great significance for the structural force system. Nowadays, the main cable saddle structures used in long-span bridges are mainly traditional anti-slip saddles and innovative [...] Read more.

The cable saddle structure is the main support component for long-span bridges to transmit cable force, which is of great significance for the structural force system. Nowadays, the main cable saddle structures used in long-span bridges are mainly traditional anti-slip saddles and innovative rolling saddles. To clarify the characteristics of the saddles in long-span bridges, the design principles, mechanical properties, and casting process of these two types of saddle structures were researched. A rolling saddle in a bridge project was taken as an example and its mechanical situation in the roller area was investigated. The results showed that the stress concentration phenomenon is prone to occurring in the rolling saddle because of the line contact in the contact area and the rolling saddle is mainly subjected to vertical force. Thus, attention should be paid to the von Mises stress in the contact area between the saddle base and the roller shaft, the lower surfaces of both ends of the roller shaft, and the top surface of the tower, to avoid material damage. Furthermore, the casting process of the anti-slip saddle structure is mature, but also faced with problems due to the welding of thick plates, and urgently needs to be improved and upgraded. The rolling saddle is used with the all-welded casting process, but its technology is relatively immature and the requirements for the roller shaft material performance are strict. The research results can provide a reference for the selection and design of the saddle structure in long-span bridges. Full article

(This article belongs to the Special Issue Bridge Structural Analysis)

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14 pages, 923 KiB

Open AccessArticle

Event-Based Modeling of Input Signal Behaviors for Discrete-Event Controllers

by Luis Gomes, Diogo Natário, Anikó Costa, João-Paulo Barros and Rogério Campos-Rebelo

Appl. Sci. 2024, 14(12), 5289; https://0-doi-org.brum.beds.ac.uk/10.3390/app14125289 (registering DOI) - 19 Jun 2024

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Abstract

Controllers for discrete-event systems are commonly designed using state-based formalisms, like state diagrams and Petri nets. These formalisms are strongly supported by the concept of events, which, from an automation system perspective, can be associated with a simple change in the value of [...] Read more.

Controllers for discrete-event systems are commonly designed using state-based formalisms, like state diagrams and Petri nets. These formalisms are strongly supported by the concept of events, which, from an automation system perspective, can be associated with a simple change in the value of a signal or more complex behavioral evolutions of the signals. In this paper, the characterization of several types of events is proposed, associated with different types of signals, such as Boolean and multivalued signals. The major goal of this characterization is to improve the compactness of the model, benefiting the editing and visual interpretation of the graphical model but keeping precise execution semantics, which in turn allows for the use of computational tools covering the different stages of system development. The behavioral model of the controller is produced using a non-autonomous class of Petri nets, the IOPT nets, and the associated IOPT-Tools, which supports the specification, simulation, property verification, and automatic code generation ready to be deployed into implementation platforms. All the types of proposed events have a behavioral sub-model executed concurrently with the main model of the controller. An application example is provided to illustrate some of the advantages of the adoption of the proposed approach, encapsulating the behavioral dependencies on the evolution of input signals into events. Full article

(This article belongs to the Topic Advances on Automatic Control and Soft Computing from 15th APCA International Conference CONTROLO’2022)

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18 pages, 10718 KiB

Open AccessArticle

Risk of Mycotoxin Contamination in Thermophilic Composting of Kitchen and Garden Waste at Large-Scale

by Maciej Woźny, Sławomir Kasiński, Kazimierz Obremski, Michał Dąbrowski and Marcin Dębowski

Appl. Sci. 2024, 14(12), 5288; https://0-doi-org.brum.beds.ac.uk/10.3390/app14125288 (registering DOI) - 19 Jun 2024

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Abstract

Although toxicogenic moulds have been identified in municipal waste and composting facilities, only a few reports exist on the occurrence of mycotoxins in compost. Those reports mostly concern sewage sludge as a substrate, tested only a limited range of mycotoxins, and did not [...] Read more.

Although toxicogenic moulds have been identified in municipal waste and composting facilities, only a few reports exist on the occurrence of mycotoxins in compost. Those reports mostly concern sewage sludge as a substrate, tested only a limited range of mycotoxins, and did not monitor the production of mycotoxins during the composting process. Therefore, this study aimed to investigate whether mycotoxins are produced during composting of selectively collected kitchen and garden waste. The study was carried out at pilot scale (550 L reactor with passive aeration). Kitchen waste (59.0% w/w), garden leaves (28.2%), and wood chips (12.8%) were used as a substrate, which was sampled every five days to determine its basic physicochemical characteristics (temperature, moisture, size-fraction content, loss on ignition) and respirometric activity (AT4). The substrate and leachate samples were also tested for the content of eight mycotoxins by HPLC-MS/MS. To screen the local compost market, commercial organic-compost samples were analysed for mycotoxin contamination. The substrate was successfully stabilized after 45 days (thermophilic peak of 62.6 °C, 40.4% mass reduction, 26.9% loss of organic matter, increase in the share of particles in the smallest size fraction, AT4 of 9.82 g O₂/kg). Although the substrate was colonised by moulds at an early stage, only trace amounts of mycotoxins were detected in a few samples. Similarly, little or no mycotoxins were found in the commercial compost. Our results suggest a low risk of mycotoxin contamination in biowaste compost produced under appropriate technological conditions. Future research should focus on screening compost produced at smaller scales (e.g., in agricultural/residential compost piles) and on identifying factors associated with the risk of mycotoxin contamination in compost. Full article

(This article belongs to the Special Issue Biological Activity, Chemical Characterization and Contaminants of Plants and Waste)

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16 pages, 4749 KiB

Open AccessArticle

Socially Assistive Robots in Smart Environments to Attend Elderly People—A Survey

by Alejandro Cruces, Antonio Jerez, Juan Pedro Bandera and Antonio Bandera

Appl. Sci. 2024, 14(12), 5287; https://0-doi-org.brum.beds.ac.uk/10.3390/app14125287 (registering DOI) - 19 Jun 2024

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Abstract

The aging of the population in developed and developing countries, together with the degree of maturity reached by certain technologies, means that the design of care environments for the elderly with a high degree of technological innovation is now being seriously considered. Assistive [...] Read more.

The aging of the population in developed and developing countries, together with the degree of maturity reached by certain technologies, means that the design of care environments for the elderly with a high degree of technological innovation is now being seriously considered. Assistive environments for daily living (Ambient Assisted Living, AAL) include the deployment of sensors and certain actuators in the home or residence where the person to be cared for lives so that, with the help of the necessary computational management and decision-making mechanisms, the person can live a more autonomous life. Although the cost of implementing such technologies in the home is still high, they are becoming more affordable, and their use is, therefore, becoming more popular. At a time when some countries are finding it difficult to provide adequate care for their elderly, this option is seen as a help for carers and to avoid collapsing health care services. However, despite the undoubted potential of the services offered by these AAL systems, there are serious problems of acceptance today. In part, these problems arise from the design phase, which often does not sufficiently take into account the end users—older people but also carers. On the other hand, it is complex for these older people to interact with interfaces that are sometimes not very natural or intuitive. The use of a socially assistive robot (SAR) that serves as an interface to the AAL system and takes responsibility for the interaction with the person is a possible solution. The robot is a physical entity that can operate with a certain degree of autonomy and be able to bring features to the interaction with the person that, obviously, a tablet or smartphone will not be able to do. The robot can benefit from the recent popularization of artificial intelligence-based solutions to personalize its attention to the person and to provide services that were unimaginable just a few years ago. Their inclusion in an AAL ecosystem should, however, also be carefully assessed. The robot’s mission should not be to replace the person but to be a tool to facilitate the elderly person’s daily life. Its design should consider the AAL system in which it is integrated, the needs and preferences of the people with whom it will interact, and the services that, in conjunction with this system, the robot can offer. The aim of this article is to review the current state of the art in the integration of SARs into the AAL ecosystem and to determine whether an initial phase of high expectations but very limited results have been overcome. Full article

(This article belongs to the Special Issue Rehabilitation and Assistive Robotics: Latest Advances and Prospects)

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