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Volume 13
Issue 19
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Appl. Sci., Volume 13, Issue 19 (October-1 2023) – 562 articles

Cover Story (view full-size image): Global climate change and associated environmental extremes present a pressing need to understand and predict social–environmental impacts while identifying opportunities for mitigation and adaptation. In support of informing a more resilient future, emerging data analytics technologies can leverage the growing availability of Earth observations from diverse data sources ranging from satellites to sensors to social media. Yet, there remains a need to transition from research for knowledge gain to sustained operational deployment. In this paper, we present a research-to-commercialization (R2C) model and conduct a case study using it to address the wicked wildfire problem through an industry–university partnership. The R2C model presented provides a basis for directing solutions-oriented science in support of value-added analytics that can inform a more resilient future. View this paper
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12 pages, 4875 KiB  
Article
The Shear Strength of Root–Soil Composites in Different Growth Periods and Their Effects on Slope Stability
by Xinlong Zhou, Dashun Fu, Juan Wan, Henglin Xiao, Xinyue He, Zhengxuan Li and Qixiang Deng
Appl. Sci. 2023, 13(19), 11116; https://doi.org/10.3390/app131911116 - 9 Oct 2023
Cited by 7 | Viewed by 2058
Abstract
Vegetation slope protection plays an important role in improving the slope stability and protecting the environment. In this study, the mechanical properties of root–soil composites in different growth periods and their effects on slope stability were investigated. First, the shear strength of undisturbed [...] Read more.
Vegetation slope protection plays an important role in improving the slope stability and protecting the environment. In this study, the mechanical properties of root–soil composites in different growth periods and their effects on slope stability were investigated. First, the shear strength of undisturbed root–soil composites associated with Cynodon dactylon (C.d), Magnolia multiflora (M.m) and grass and shrub mixture (G.s) were measured by large direct shear tests. Then, the effects of plant reinforcement in different growth periods on slope stability were analyzed using ABAQUS. The results show that the shear strength of the root–soil composites were significantly higher than that of the unreinforced soil. The root–soil composites met the Mohr–Coulomb criterion. The shear strength of the three root–soil composites increased first and then decreased during the vegetation growth period. The calculation results show that the factor of safety (FS) of the bare slope was 1.482. The FS values of the C.d, M.m, and G.s slopes were 1.601, 1.658 and 1.715, which increased by 8%, 11.9% and 15.7% compared to the bare soil slopes. Therefore, vegetation could significantly improve slope stability, especially the grass–shrub mixture model. This could provide a rational basis for designing and constructing plant slope protection. Full article
(This article belongs to the Section Civil Engineering)
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Figure 1
<p>Direct shear test. (<b>a</b>) Direct shear device; (<b>b</b>) after setting the sample; (<b>c</b>) after sample destruction.</p> Full article ">Figure 2
<p>Shear strength under four normal stresses during the different growth periods.</p> Full article ">Figure 3
<p>Fitting curves associated with the different plants. (<b>a</b>) C.d; (<b>b</b>) M.m; and (<b>c</b>) G.s.</p> Full article ">Figure 4
<p>The geometrical parameters for slope modeling (unit: cm).</p> Full article ">Figure 5
<p>Slope stability results. (<b>a</b>) The FS values of C.d; (<b>b</b>) the FS values of M.m; (<b>c</b>) the FS values of G.s.</p> Full article ">Figure 6
<p>Nephograms of horizontal displacement under different conditions (unit: m).</p> Full article ">Figure 7
<p>Nephogram of the equivalent plastic strain magnitude (PEMAG) at slope failure.</p> Full article ">
19 pages, 5555 KiB  
Article
Remote Control Device to Drive the Arm Gestures of an Assistant Humanoid Robot
by Elena Rubies, Ricard Bitriá, Eduard Clotet and Jordi Palacín
Appl. Sci. 2023, 13(19), 11115; https://doi.org/10.3390/app131911115 - 9 Oct 2023
Cited by 1 | Viewed by 2235
Abstract
This work presents a remote control device designed to drive the arm gestures of an assistant humanoid mobile robot. The remote control is a master device with two passive arms configured to replicate the four degrees of freedom of each arm of the [...] Read more.
This work presents a remote control device designed to drive the arm gestures of an assistant humanoid mobile robot. The remote control is a master device with two passive arms configured to replicate the four degrees of freedom of each arm of the original assistant humanoid robot and send this information to the robot. This configuration allows the mobile robot to directly replicate the position of the arms on the remote controller. The objective of this proposal is to provide the robot with enhanced non-verbal and pointing communication capabilities during human interaction or assistance. The master device registers the angular position of each joint of its passive arms and transmits this information to the mobile robot, which replicates it. The experimental evaluation of the system has shown that the humanoid robot is able to successfully replicate any gesture on the remote controller. The positions of the arms have been sampled at a frame rate of 20 ms, and the average telecontrol delay obtained in the gesture experiments has been 549 ms, without appreciable jumps or irregularities in the gestures. The conclusion is that the direct manipulation of the passive arms of the remote control device provides the APR-02 humanoid robot with enhanced non-verbal and pointing communication capabilities during human interaction or assistance. Full article
(This article belongs to the Special Issue Robotic Systems for Inspections and Surveillance of Industrial Infrastructure)
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<p>APR-02 robot used in this paper moving its hands to knock at a door: (<b>a</b>) Side view of the robot; (<b>b</b>) teleoperator view from the panoramic camera available on the head of the robot.</p> Full article ">Figure 2
<p>Kinematic representation of the joints of the remote control device, which is a scaled-down reproduction of the upper part of the APR-02 robot, with four degrees of freedom in each arm.</p> Full article ">Figure 3
<p>Schematic diagram of the electronic control board: the position of the arm joints is measured using potentiometers, and two gamepads including buttons and potentiometers provide direct access to several mobile robot functions.</p> Full article ">Figure 4
<p>Shoulder joints detail seen from below: (<b>a</b>) Robot shoulder; (<b>b</b>) CAD model of the remote control device; (<b>c</b>) implementation of the remote control device.</p> Full article ">Figure 5
<p>Elbow joint detail: (<b>a</b>) Robot elbow; (<b>b</b>) CAD model of the remote control device; (<b>c</b>) implementation of the remote control device.</p> Full article ">Figure 6
<p>Front view of the gamepads and functions of each button: (<b>a</b>) right arm; (<b>b</b>) left arm.</p> Full article ">Figure 7
<p>Body structure of the remote control device: (<b>a</b>) CAD model; (<b>b</b>) implementation.</p> Full article ">Figure 8
<p>Structure of the imitation model: the operator moves the arms of the remote control device; the positions of the joints are measured, mapped, and sent to the APR-02 mobile robot.</p> Full article ">Figure 9
<p>Evolution of the joint angles measured by the remote control device when the arms perform three circular inwards trajectories in the air: (<b>a</b>) right arm; (<b>b</b>) left arm.</p> Full article ">Figure 10
<p>Evolution of the joint angles when the arms of the mobile robot perform four circular inwards trajectories in the air: (<b>a</b>) right arm; (<b>b</b>) left arm. Solid lines depict the joint position received by the mobile robot, and dotted lines depict the real evolution of the joints of the robot.</p> Full article ">Figure 11
<p>Evolution of the joint angles when the arms of the remote control device perform three lateral trajectories in the air: starting from a neutral position, moving upwards-left, and then horizontally to the right, returning to the left and repeating to the right: (<b>a</b>) right arm; (<b>b</b>) left arm. Solid lines depict the joint position received by the mobile robot, and dotted lines depict the real evolution of the joints of the robot.</p> Full article ">
19 pages, 3039 KiB  
Article
HS-YOLO: Small Object Detection for Power Operation Scenarios
by Zhiwei Lin, Weihao Chen, Lumei Su, Yuhan Chen and Tianyou Li
Appl. Sci. 2023, 13(19), 11114; https://doi.org/10.3390/app131911114 - 9 Oct 2023
Cited by 5 | Viewed by 2037
Abstract
Object detection methods are commonly employed in power safety monitoring systems to detect violations in surveillance scenes. However, traditional object detection methods are ineffective for small objects that are similar to the background information in the power monitoring scene, which consequently affects the [...] Read more.
Object detection methods are commonly employed in power safety monitoring systems to detect violations in surveillance scenes. However, traditional object detection methods are ineffective for small objects that are similar to the background information in the power monitoring scene, which consequently affects the performance of violation behavior detection. This paper proposed a small object detection algorithm named HS-YOLO, based on High-Resolution Network (HRNet) and sub-pixel convolution. First, to fully extract the microfeature information of the object, a small object feature extraction backbone network is proposed based on the HRNet structure. The feature maps of different scales are processed by multiple parallel branches and fused with each other in the network. Then, to fully retain the effective features of small objects, the sub-pixel convolution module is incorporated as the upsampling operator in the feature fusion network. The low-resolution feature map is upsampled to a higher resolution by reorganizing pixel values and performing padding operations in this module. On our self-constructed power operation dataset, the HS-YOLO algorithm achieved a mAP of 87.2%, which is a 3.5% improvement compared to YOLOv5. Particularly, the dataset’s AP for detecting small objects such as cuffs, necklines, and safety belts is improved by 10.7%, 5.8%, and 4.4%, respectively. These results demonstrate the effectiveness of our proposed method in detecting small objects in power operation scenarios. Full article
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Graphical abstract

Graphical abstract
Full article ">Figure 1
<p>Network structure of the HS-YOLO algorithm.</p> Full article ">Figure 2
<p>HRNet Feature Extraction Backbone Network.</p> Full article ">Figure 3
<p>Different resolution feature map fusion methods.</p> Full article ">Figure 4
<p>Sub-pixel convolution implements the upsampling process.</p> Full article ">Figure 5
<p>Object size under different shooting distance and angle. (<b>a</b>,<b>b</b>) represents objects that have always been small in the monitoring image; (<b>c</b>,<b>d</b>) represents objects that vary greatly in scale in the surveillance image.</p> Full article ">Figure 6
<p>The training loss comparison between HS-YOLO and the original YOLOv5 on the dataset for power operation. (<b>a</b>) represents a comparison in total training loss; (<b>b</b>) represents a comparison in confidence loss; (<b>c</b>) represents a comparison of classified loss; (<b>d</b>) represents a comparison in bounding box regression loss.</p> Full article ">Figure 7
<p>The detection results of the method before and after improvement on the power operation scenarios dataset. (<b>a</b>) the detection results of the YOLOv5 model; (<b>b</b>) the detection results of the HS-YOLO model.</p> Full article ">Figure 8
<p>The training loss comparison between HS-YOLO and the original YOLOv5 on the COCO dataset. (<b>a</b>) represents a comparison in total training loss; (<b>b</b>) represents a comparison in confidence loss; (<b>c</b>) Represents a comparison of classified loss; (<b>d</b>) represents a comparison in bounding box regression loss.</p> Full article ">
15 pages, 3105 KiB  
Article
Parametric Analysis for Hybrid–Electric Regional Aircraft Conceptual Design and Development
by Giuseppe Palaia, Karim Abu Salem and Alessandro A. Quarta
Appl. Sci. 2023, 13(19), 11113; https://doi.org/10.3390/app131911113 - 9 Oct 2023
Cited by 8 | Viewed by 1874
Abstract
This paper proposes a conceptual analysis of the limitations related to the development (and integration) of hybrid–electric propulsion on regional transport aircraft, with the aim to identify a feasibility space for this innovative aircraft concept. Hybrid–electric aircraft have attracted the interest of aeronautical [...] Read more.
This paper proposes a conceptual analysis of the limitations related to the development (and integration) of hybrid–electric propulsion on regional transport aircraft, with the aim to identify a feasibility space for this innovative aircraft concept. Hybrid–electric aircraft have attracted the interest of aeronautical research as these have the potential to reduce fuel consumption and, thus, the related greenhouse gas emissions. Nevertheless, considering the development of such an aircraft configuration while keeping the constraints deriving from technological and/or operating aspects loose could lead to the analysis of concepts that are unlikely to be realised. In this paper, specifically to outline the boundaries constraining the actual development of such aircraft, the influence on overall aircraft design and performance of the main technological, operating, and design factors characterising the development of such a configuration is analysed and discussed at a conceptual level. Specifically, the current achievable gravimetric battery energy density (BED) is identified as the main limiting factor for the development of regional hybrid–electric aircraft, and a sensitivity analysis shows the correlation of this important technological parameter with aircraft performance in terms of both fuel consumption and energy efficiency. In this context, minimum technological development thresholds are therefore identified to enable the effective development of this type of aircraft; namely, a minimum of BED = 500 Wh/kg at battery pack level is identified as necessary to provide tangible benefits. From an operating point of view, flight distance is the most limiting design requirement, and a proper assessment of the design range is necessary if a hybrid–electric aircraft is to be designed to achieve lower emissions than the state of the art; flight ranges equal to or lower than 600 nm are to be considered for this type of aircraft. As a bridging of both of the previous constraints, a change in the design paradigm with respect to established practices for state-of-the-art aircraft is necessary. More specifically, penalisations in maximum take-off weight and overall aircraft energy efficiency may be necessary if the aim is to reduce direct in-flight consumption by means of integration of hybrid–electric powertrains. Full article
(This article belongs to the Special Issue Aerotech, Aerospace and Security Applications in the Age of Artificial Intelligence Support for Industry 4.0 and Green Technology)
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Figure 1
<p>Conceptual sketch of hybrid–electric aircraft power supply strategy (adapted from [<a href="#B36-applsci-13-11113" class="html-bibr">36</a>]).</p> Full article ">Figure 2
<p><math display="inline"><semantics> <mrow> <msub> <mi mathvariant="italic">m</mi> <mrow> <mi mathvariant="italic">fb</mi> </mrow> </msub> <mo> </mo> </mrow> </semantics></math> vs. MTOW varying <span class="html-italic">BED</span>, for optimisations with FoM ≜<math display="inline"><semantics> <mrow> <msub> <mrow> <mrow> <mo> </mo> <mi mathvariant="italic">m</mi> </mrow> </mrow> <mrow> <mi mathvariant="italic">fb</mi> </mrow> </msub> </mrow> </semantics></math> @600 nm.</p> Full article ">Figure 3
<p><math display="inline"><semantics> <mrow> <msub> <mi mathvariant="italic">m</mi> <mi mathvariant="italic">b</mi> </msub> <mo> </mo> </mrow> </semantics></math> vs. MTOW varying BED, for optimisations with FoM ≜<math display="inline"><semantics> <mrow> <mo> </mo> <msub> <mi mathvariant="italic">m</mi> <mrow> <mi mathvariant="italic">fb</mi> </mrow> </msub> </mrow> </semantics></math> @600 nm.</p> Full article ">Figure 4
<p><span class="html-italic">PREE</span> vs. MTOW varying BED, for optimisations with FoM ≜<math display="inline"><semantics> <mrow> <mo> </mo> <msub> <mi mathvariant="italic">m</mi> <mrow> <mi mathvariant="italic">fb</mi> </mrow> </msub> </mrow> </semantics></math> @600 nm.</p> Full article ">Figure 5
<p><span class="html-italic">PREE</span> vs. MTOW varying <span class="html-italic">BED,</span> for optimisations with FoM ≜ <span class="html-italic">PREE</span> @600 nm.</p> Full article ">Figure 6
<p>Parallel hybrid–electric powertrain <span class="html-italic">η</span> (left), total energy supplied (right) @600 nm.</p> Full article ">Figure 7
<p><math display="inline"><semantics> <mrow> <msub> <mi mathvariant="italic">m</mi> <mrow> <mi mathvariant="italic">fb</mi> </mrow> </msub> </mrow> </semantics></math> vs. MTOW varying BED, for optimisations with FoM ≜ <span class="html-italic">PREE</span> @600 nm.</p> Full article ">Figure 8
<p><math display="inline"><semantics> <mrow> <msub> <mi mathvariant="italic">m</mi> <mrow> <mi mathvariant="italic">fb</mi> </mrow> </msub> <mo> </mo> </mrow> </semantics></math> (left), <span class="html-italic">PREE</span> vs. MTOW (right) varying <span class="html-italic">BED</span>; optimisations with FoM ≜<math display="inline"><semantics> <mrow> <msub> <mrow> <mrow> <mo> </mo> <mi mathvariant="italic">m</mi> </mrow> </mrow> <mrow> <mi mathvariant="italic">fb</mi> </mrow> </msub> </mrow> </semantics></math>, @400 nm.</p> Full article ">Figure 9
<p><math display="inline"><semantics> <mrow> <msub> <mi mathvariant="italic">m</mi> <mrow> <mi mathvariant="italic">fb</mi> </mrow> </msub> <mo> </mo> </mrow> </semantics></math> (left), <span class="html-italic">PREE</span> vs. MTOW (right) varying <span class="html-italic">BED</span>; optimisations with FoM ≜ <span class="html-italic">PREE</span> @400 nm.</p> Full article ">Figure 10
<p><math display="inline"><semantics> <mrow> <msub> <mi mathvariant="italic">m</mi> <mrow> <mi mathvariant="italic">fb</mi> </mrow> </msub> <mo> </mo> </mrow> </semantics></math> vs. MTOW (left), <span class="html-italic">PREE</span> vs. MTOW (right) varying <span class="html-italic">BED</span>, for optimisations with FoM ≜<math display="inline"><semantics> <mrow> <mo> </mo> <msub> <mi mathvariant="italic">m</mi> <mrow> <mi mathvariant="italic">fb</mi> </mrow> </msub> </mrow> </semantics></math> @800 nm.</p> Full article ">
17 pages, 1018 KiB  
Article
Applying Machine Learning in Retail Demand Prediction—A Comparison of Tree-Based Ensembles and Long Short-Term Memory-Based Deep Learning
by Mehran Nasseri, Taha Falatouri, Patrick Brandtner and Farzaneh Darbanian
Appl. Sci. 2023, 13(19), 11112; https://doi.org/10.3390/app131911112 - 9 Oct 2023
Cited by 5 | Viewed by 8872
Abstract
In the realm of retail supply chain management, accurate forecasting is paramount for informed decision making, as it directly impacts business operations and profitability. This study delves into the application of tree-based ensemble forecasting, specifically using extra tree Regressors (ETRs) and long short-term [...] Read more.
In the realm of retail supply chain management, accurate forecasting is paramount for informed decision making, as it directly impacts business operations and profitability. This study delves into the application of tree-based ensemble forecasting, specifically using extra tree Regressors (ETRs) and long short-term memory (LSTM) networks. Utilizing over six years of historical demand data from a prominent retail entity, the dataset encompasses daily demand metrics for more than 330 products, totaling 5.2 million records. Additionally, external variables, such as meteorological and COVID-19-related data, are integrated into the analysis. Our evaluation, spanning three perishable product categories, reveals that the ETR model outperforms LSTM in metrics including MAPE, MAE, RMSE, and R2. This disparity in performance is particularly pronounced for fresh meat products, whereas it is marginal for fruit products. These ETR results were evaluated alongside three other tree-based ensemble methods, namely XGBoost, Random Forest Regression (RFR), and Gradient Boosting Regression (GBR). The comparable performance across these four tree-based ensemble techniques serves to reinforce their comparative analysis with LSTM-based deep learning models. Our findings pave the way for future studies to assess the comparative efficacy of tree-based ensembles and deep learning techniques across varying forecasting horizons, such as short-, medium-, and long-term predictions. Full article
(This article belongs to the Special Issue Deep Learning in Supply Chain and Logistics)
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Figure 1
<p>Demand forecasting process.</p> Full article ">Figure 2
<p>The architecture of an LSTM cell.</p> Full article ">Figure 3
<p>The network structure of the DL model.</p> Full article ">
25 pages, 5764 KiB  
Article
Study on Stability of Elastic Compression Bending Bar in Viscoelastic Medium
by Xiaochun Zhang, Jianhan Hu and Shuyang Chen
Appl. Sci. 2023, 13(19), 11111; https://doi.org/10.3390/app131911111 - 9 Oct 2023
Cited by 3 | Viewed by 1433
Abstract
In the southeastern coastal regions of China, thick layers of marine soft soil are widely distributed, exhibiting characteristics such as high compressibility, high porosity, low strength, high sensitivity, and easy thixotropy, and these viscoelastic behaviors of foundation soil have significant implications for elastic [...] Read more.
In the southeastern coastal regions of China, thick layers of marine soft soil are widely distributed, exhibiting characteristics such as high compressibility, high porosity, low strength, high sensitivity, and easy thixotropy, and these viscoelastic behaviors of foundation soil have significant implications for elastic compression bending bar, as evidenced by issues such as post-construction settlement of roadbeds and long-term operation deviation of bridge pile foundations. In this study, a mechanical model of an elastic bar embedded in an elastic and viscoelastic medium, fixed at the base and free at the top, is established based on the Winkler foundation assumption. The deflection function of a bar subjected to both axial force and locally distributed horizontal load is derived using the Rayleigh-Ritz method. Utilizing the elastic-viscoelastic correspondence principle, the viscoelastic medium surrounding the bar is modeled as an elastic medium in which the ground reaction coefficient varies within phase space formulation. This study provides a robust theoretical foundation for soft soil foundation engineering projects and fills a significant gap in the literature by offering a comprehensive framework for understanding displacement in elastic bars within viscoelastic media. Drawing upon the derivation of the deformation function for elastic rods within a viscoelastic medium, the findings of this research hold significant applicability across a range of domains. These include, but are not limited to, the expansion of roadways in regions characterized by coastal soft soil, as well as the monitoring of deformation and lifespan in bridge pile foundations. Full article
(This article belongs to the Topic Nonlinear Phenomena, Chaos, Control and Applications to Engineering and Science and Experimental Aspects of Complex Systems)
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Figure 1

Figure 1
<p>Spring elements and dashpot elements.</p> Full article ">Figure 2
<p>Kelvin model.</p> Full article ">Figure 3
<p>Van Der Poel model.</p> Full article ">Figure 4
<p>Winkler foundation model.</p> Full article ">Figure 5
<p>Model of elastic compression bending bar in elastic medium.</p> Full article ">Figure 6
<p>FEM model of single bar with elastic medium.</p> Full article ">Figure 7
<p>Comparison of numerical and analytical solutions for horizontal stress.</p> Full article ">Figure 8
<p>Model of elastic compression bending bar in viscoelastic medium.</p> Full article ">Figure 9
<p>The time history of displacement variation when <span class="html-italic">L</span> = 50. (<b>a</b>) Total change duration of the lateral deflection <span class="html-italic">w</span>(<span class="html-italic">L</span>); (<b>b</b>) The change duration of <span class="html-italic">w</span>(<span class="html-italic">L</span>) during the initial stage of load application.</p> Full article ">Figure 10
<p>Relationship between axial force <span class="html-italic">P</span> and critical instability time <span class="html-italic">t<sub>cr</sub></span>.</p> Full article ">Figure 11
<p>Relationship between axial force <span class="html-italic">P</span> and <span class="html-italic">t<sub>cr</sub></span> corresponding to different length of bar <span class="html-italic">L.</span> (<b>a</b>) Different axial force (<span class="html-italic">P</span>) series under variable length of bar (<span class="html-italic">L</span>); (<b>b</b>) Single axial force (<span class="html-italic">P</span>) series under variable length of bar (<span class="html-italic">L</span>).</p> Full article ">Figure 12
<p>Relationship between <span class="html-italic">L</span> and <span class="html-italic">t<sub>cr</sub></span> under different axial forces.</p> Full article ">Figure 13
<p>Relationship between <span class="html-italic">P</span> and <span class="html-italic">t<sub>cr</sub></span> corresponding to different <span class="html-italic">L</span>.</p> Full article ">Figure 14
<p><span class="html-italic">t<sub>cr</sub></span>-<span class="html-italic">P</span> curve under different load strength.</p> Full article ">Figure A1
<p>Vertical stress caused by a flexible strip load [<a href="#B46-applsci-13-11111" class="html-bibr">46</a>].</p> Full article ">Figure A2
<p>Burgers Model.</p> Full article ">
26 pages, 7723 KiB  
Article
A Feasibility Study for a Hand-Held Acoustic Imaging Camera
by Danilo Greco
Appl. Sci. 2023, 13(19), 11110; https://doi.org/10.3390/app131911110 - 9 Oct 2023
Viewed by 2122
Abstract
Acoustic imaging systems construct spatial maps of sound sources and have potential in various applications, but large, cumbersome form factors limit their adoption. This paper investigates methodologies to miniaturize acoustic camera systems for improved mobility. Our approach optimizes planar microphone array design to [...] Read more.
Acoustic imaging systems construct spatial maps of sound sources and have potential in various applications, but large, cumbersome form factors limit their adoption. This paper investigates methodologies to miniaturize acoustic camera systems for improved mobility. Our approach optimizes planar microphone array design to achieve directional sensing capabilities on significantly reduced footprints compared to benchmarks. The current prototype utilizes a 128−microphone, 50 × 50 cm2 array with beamforming algorithms to visualize acoustic fields in real time but its stationary bulk hampers portability. We propose minimizing the physical aperture by carefully selecting microphone positions and quantities with tailored spatial filter synthesis. This irregular array geometry concentrates sensitivity toward target directions while avoiding aliasing artefacts. Simulations demonstrate a 32−element, ≈20 × 20 cm2 array optimized this way can outperform the previous array in directivity and noise suppression in a sub-range of frequencies below 4 kHz, supporting a 4× surface factor reduction with acceptable trade-offs. Ongoing work involves building and testing miniature arrays to validate performance predictions and address hardware challenges. The improved mobility of compact acoustic cameras could expand applications in car monitoring, urban noise mapping and other industrial fields limited by current large systems. Full article
(This article belongs to the Special Issue New Advances in Audio Signal Processing)
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<p><span class="html-italic">Dual Cam</span> prototype integrates co-located acoustic and visual imaging modalities using a planar microphone array paired with a video camera [<a href="#B10-applsci-13-11110" class="html-bibr">10</a>].</p> Full article ">Figure 2
<p>Broadband beamforming issues (1-D): (a) low directivity at low frequencies and (b) aliasing at high frequencies. <math display="inline"><semantics> <mrow> <mi>B</mi> <mo>(</mo> <mi>f</mi> <mo>,</mo> <mi>ϕ</mi> <mo>)</mo> </mrow> </semantics></math>, beampattern; <span class="html-italic">f</span>, function of frequency; <math display="inline"><semantics> <mi>ϕ</mi> </semantics></math>, DOA (direction of arrival) [<a href="#B17-applsci-13-11110" class="html-bibr">17</a>].</p> Full article ">Figure 3
<p>Simulation of a periodic 32−microphone positioning on a planar array 25 × 25 cm<sup>2</sup>.</p> Full article ">Figure 4
<p>Two−dimensional beam pattern using a periodic positioning of 32−microphones on a planar array 25 × 25 cm<sup>2</sup> (<a href="#applsci-13-11110-f003" class="html-fig">Figure 3</a>) at different frequencies: (<b>a</b>) beam pattern at 2 kHz, (<b>b</b>) beam pattern at ≈6 kHz, both functions of <math display="inline"><semantics> <mi>θ</mi> </semantics></math> and <math display="inline"><semantics> <mi>ϕ</mi> </semantics></math> (<span class="html-italic">u</span> and <span class="html-italic">v</span>; see later on). Increasing the frequency, the grating lobes equal the main central lobe. The colorbar maps from 0 dB (yellow) to -30 dB (blue).</p> Full article ">Figure 5
<p>From raw audio (<b>a</b>) to 3-D acoustic image (<b>b</b>) to 2-D energy heatmap (<b>c</b>) (from red maximum sound to blue minimum sound) [<a href="#B44-applsci-13-11110" class="html-bibr">44</a>].</p> Full article ">Figure 6
<p>Three examples from a collected dataset. We visualize the acoustic image by summing the energy of all frequencies for each acoustic pixel. The resulting map (from red maximum sound to blue minimum sound) is overlaid on the corresponding RGB frame. From left to right: (<b>a</b>) drone, (<b>b</b>) train, (<b>c</b>) vacuum cleaner [<a href="#B42-applsci-13-11110" class="html-bibr">42</a>].</p> Full article ">Figure 7
<p>New <span class="html-italic">Dual Cam</span> 2.0 POC (proof of concept) idea. The periodic positioning of the microphones is generic and for illustrative purposes only.</p> Full article ">Figure 8
<p>The <span class="html-italic">Dual Cam</span> board is based on an FPGA that reads continuously from the I2S MEMS microphones (TDK/InvenSense); using a programmed DMA the read microphones values are stored in a RAM buffer. In our new proof of concept (POC) the processor can easily read data from RAM and redirect them to the USB port.</p> Full article ">Figure 9
<p>Conceptual framework in the microphone array simulation.</p> Full article ">Figure 10
<p>Cartesian coordinates system and steering angles (<math display="inline"><semantics> <msub> <mi>θ</mi> <mn>0</mn> </msub> </semantics></math>, <math display="inline"><semantics> <msub> <mi>ϕ</mi> <mn>0</mn> </msub> </semantics></math>).</p> Full article ">Figure 11
<p>Flow chart of Simulated Annealing algorithm for function cost minimization.</p> Full article ">Figure 12
<p>Simulation results for [2, 6.4] kHz optimization of a 32−elements 0.25 m acoustic array: (<b>a</b>) cost function convergence over 100 iterations, (<b>b</b>) optimized 32−microphone 0.25 m array layout.</p> Full article ">Figure 13
<p>(<b>a</b>) Directivity and (<b>b</b>) white noise gain metrics confirm reasonable performance across the [2, 6.4] kHz band from the 0.25 m array.</p> Full article ">Figure 14
<p>Simulation array 25 × 25 cm<sup>2</sup>. Beam patterns within the optimization band and the aperiodic microphone localization exhibit low sidelobes and main lobe focusing (<a href="#applsci-13-11110-f004" class="html-fig">Figure 4</a>). (<b>a</b>) 2 kHz, (<b>b</b>) ≈4 kHz, (<b>c</b>) ≈6 kHz.</p> Full article ">Figure 15
<p>Simulation results for [2, 6.4] kHz optimization of a 32−element 0.21 m acoustic array: (<b>a</b>) cost function convergence over <math display="inline"><semantics> <mrow> <mo>≈</mo> <msup> <mn>10</mn> <mn>5</mn> </msup> </mrow> </semantics></math> iterations, (<b>b</b>) optimized 32−microphone 0.21 m array layout.</p> Full article ">Figure 16
<p>(<b>a</b>) Directivity and (<b>b</b>) white noise gain metrics confirm reasonable performance across the [2,6.4] kHz band even from the reduced 0.21 m array.</p> Full article ">Figure 17
<p>Simulation results for [2, 6.4] kHz optimization of a 32−element 0.21 m acoustic array. Beampatten comparison: BP (<b>left</b>) vs EBPP (<b>right</b>) at 2 kHz.</p> Full article ">Figure 18
<p>Simulation results for [2, 6.4] kHz optimization of a 32−element 0.21 m acoustic array. Beampatten comparison: BP (<b>left</b>) vs EBPP (<b>right</b>) at ≈6 kHz.</p> Full article ">Figure 19
<p>Simulation results for [0.5, 6.4] kHz optimization of a 32−element 0.21 × 0.21 m<sup>2</sup> planar acoustic array: (<b>a</b>) cost function convergence over <math display="inline"><semantics> <mrow> <mo>≈</mo> <msup> <mn>10</mn> <mn>5</mn> </msup> </mrow> </semantics></math> iterations, (<b>b</b>) optimized 32−microphone 0.21 m array layout.</p> Full article ">Figure 20
<p>Current <span class="html-italic">Dual Cam</span> prototype. Simulation results for [0.5, 6.4] kHz optimization of a 128−element 0.50 × 0.50 m<sup>2</sup> planar acoustic array: (<b>a</b>) cost function convergence over ≈<math display="inline"><semantics> <msup> <mn>10</mn> <mn>5</mn> </msup> </semantics></math> iterations, (<b>b</b>) optimized 128−microphone 0.50 m array layout.</p> Full article ">Figure 21
<p><span class="html-italic">Dual Cam</span> 2.0 with larger audio bandwidth [500, 6400] Hz on a 0.21 × 0.21 m<sup>2</sup> array. Directivity (<b>a</b>) and WNG (<b>b</b>).</p> Full article ">Figure 22
<p>Current <span class="html-italic">Dual Cam</span> prototype. Expected beam pattern power at different frequencies: (<b>a</b>) 500 Hz, (<b>b</b>) ≈2.5 kHz, (<b>c</b>) ≈6 kHz.</p> Full article ">Figure 23
<p>Current <span class="html-italic">Dual Cam</span> prototype: (<b>a</b>) Directivity and (<b>b</b>) WNG over the full bandwidth [500, 6400] Hz on a 50 × 50 cm<sup>2</sup> array.</p> Full article ">Figure 24
<p><span class="html-italic">Dual Cam</span> 2.0 cted beam pattern power at different frequencies: (<b>a</b>) 500 Hz, (<b>b</b>) ≈2.5 kHz, (<b>c</b>) ≈6 kHz.</p> Full article ">Figure 25
<p><span class="html-italic">Dual Cam</span> 2.0 with larger audio bandwidth [0.5, 6.4] kHz: effect of the FIR length on the metrics of the evaluation. (<b>a</b>) Directivity with K = 7 (red) vs K = 21 (blue); (<b>b</b>) WNG with K = 7 (red) vs. K = 21 (blue).</p> Full article ">Figure 26
<p><span class="html-italic">Dual Cam</span> 2.0 Business Model Canvas.</p> Full article ">
13 pages, 3413 KiB  
Article
A Proposed Settlement and Distribution Structure for Music Royalties in Korea and Their Artificial Intelligence-Based Applications
by Youngmin Kim, Donghwan Kim, Sunho Park, Yonghwa Kim, Jisoo Hong, Sunghee Hong, Jinsoo Jeong, Byounghyo Lee and Hyeonchan Oh
Appl. Sci. 2023, 13(19), 11109; https://doi.org/10.3390/app131911109 - 9 Oct 2023
Cited by 1 | Viewed by 2530
Abstract
Digital music is one of the most important commodities on the market due to music royalty distribution in Korea. As the music market has been transformed into a digital music market by means such as downloading and streaming, the distribution of music royalties [...] Read more.
Digital music is one of the most important commodities on the market due to music royalty distribution in Korea. As the music market has been transformed into a digital music market by means such as downloading and streaming, the distribution of music royalties via online service providers (OSPs) has become a highly important issue for music rights holders. Currently, one of the most important issues in music royalty distribution in Korea is the unfair distribution of royalties due to the indiscriminate repeat streaming of digital music. To prevent this, music consumption log data from several OSPs were collected via a day-based system; however, there was a limit on the identification of detailed information on the use of music in its current state. This paper analyzes the structural problems and limitations related to the settlement of music royalties and provides a structure in which there can be transparent settlement and distribution between users and rights holders as an institutional measure. We also propose various AI (artificial intelligence)-based applications using music consumption log data. The proposed system will hopefully be used for public purposes. Full article
(This article belongs to the Special Issue New Technologies and Applications of Edge/Fog Computing Based on Artificial Intelligence and Machine Learning)
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<p>An example of music streaming service revenue share. (Red: revenue share)</p> Full article ">Figure 2
<p>Proposed settlement–distribution structure based on meta-log information analysis.</p> Full article ">Figure 3
<p>Flow chart of the settlement and distribution of music royalties based on the proposed method.</p> Full article ">Figure 4
<p>An example of a settlement and distribution system applying all three modules.</p> Full article ">Figure 5
<p>A process diagram for managing the unique key of an independent organization.</p> Full article ">Figure 6
<p>An example of a polymorphic pseudonymization algorithm module.</p> Full article ">Figure 7
<p>Sample songs, including usage data with several indexes (several songs and singers were written in Korean).</p> Full article ">Figure 8
<p>An example of an anomaly in the detection of music streaming. The horizontal axis denotes each song, and the <span class="html-italic">y</span> axis denotes the normalization results of the AutoEncoder model. A red dot indicates anomalous data of the streamed song.</p> Full article ">Figure 9
<p>A prediction graph based on music usage during five months (19 May 2021 to 6 October 2021) after releasing a song. The blue line indicates training data, the green line indicates test data (actual data), and the red line indicates the predicted data after five months.</p> Full article ">
22 pages, 1889 KiB  
Article
Relevance of Surface Electromyography Assessment and Sleep Impairment in Scoliosis: A Pilot Study
by Denisa Piele, Eva Ilie, Ligia Rusu and Mihnea Ion Marin
Appl. Sci. 2023, 13(19), 11108; https://doi.org/10.3390/app131911108 - 9 Oct 2023
Cited by 1 | Viewed by 1695
Abstract
Background: According to statistics, worldwide, the number of young persons diagnosed with idiopathic scoliosis has tripled in the last 10 years. This tendency seems to be related to the development of technological devices that induce vicious postures. Specialized literature shows that the predicted [...] Read more.
Background: According to statistics, worldwide, the number of young persons diagnosed with idiopathic scoliosis has tripled in the last 10 years. This tendency seems to be related to the development of technological devices that induce vicious postures. Specialized literature shows that the predicted evolution will lead to a tripling of the population affected by scoliosis by 2050. Associated complications can be most varied, with functional or respiratory and cardiac impairment being the most severe. The purpose of this study is to objectify the effect of associating Schroth therapy with general elements of global postural reeducation (GPR) therapy in the treatment of scoliosis using electromyography, scoliosis assessment scales, and sleep quality evaluation. The present study is addressed to scoliotic patients. Methods: In order to assess the muscle imbalance installed in scoliosis, we have used SEMG, while Epworth, Baecke, and SAQ scales assessed sleepiness, physical activity levels, and self-perception of the scoliotic patient. Results: After performing a therapeutic protocol that combines Schroth and global postural reeducation (GPR) exercises, an improvement of the functional status was observed for the scoliotic patients. The statistical analysis presents a favorable symmetry index during flexion (p = 0.042), a significant difference in the Epworth score (p = 0.002), as well as a significant difference in the SAQ2 score (p = 0.049). Conclusion: Early detection of scoliosis prevents functional degradation. On the other hand, developing an adequate therapeutic protocol leads to an improved functional status and increased life quality. Full article
(This article belongs to the Special Issue Physical Activity and Sleep Duration on Health)
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<p>Adam’s test.</p> Full article ">Figure 2
<p>Electrode placement at a distance of 2 cm from the spine’s axis on the right and left side of the scoliotic’s curvature apex. A neutral electrode was positioned on the spinous process of the C7 vertebra.</p> Full article ">Figure 3
<p>(<b>a</b>) Frog on the ground (GPR) (<b>b</b>) Frog in the air (GPR).</p> Full article ">Figure 4
<p>Schroth posture. (<b>a</b>) Schroth posture 1; (<b>b</b>) Schroth posture 2.</p> Full article ">
21 pages, 15663 KiB  
Article
Application of the Ground Penetrating Radar (GPR) and Electromagnetic (EM34-3) Geophysical Tools and Sedimentology for the Evaluation of the Subsurface of Sites Earmarked for Aquaculture Ponds in the Amazon Region of Northern Brazil
by Ramon Wagner Torres Pena, Pedro Andrés Chira Oliva and Fernando Araújo Abrunhosa
Appl. Sci. 2023, 13(19), 11107; https://doi.org/10.3390/app131911107 - 9 Oct 2023
Cited by 4 | Viewed by 3096
Abstract
The present study evaluated the application of Ground Penetrating Radar and Electromagnetic Induction geophysical tools combined with sedimentology for the description of the subsurface of sites destined for the installation of ponds for an extensive freshwater fish farming system. Two areas with similar [...] Read more.
The present study evaluated the application of Ground Penetrating Radar and Electromagnetic Induction geophysical tools combined with sedimentology for the description of the subsurface of sites destined for the installation of ponds for an extensive freshwater fish farming system. Two areas with similar topographic characteristics (flat land near bodies of water) were investigated in the Amazon region of northern Brazil: Area 1—the future site of an aquaculture research center, and Area 2—an established fish farming operation. These tools performed well in the evaluation of the suitability of the terrain for the installation of aquaculture ponds. The application of these tools can, thus, be recommended for aquaculture projects, given that it provides advanced knowledge on the characteristics of the local soils, which is extremely important to guarantee the sustainability of any aquaculture operation. These data can help minimize the environmental impacts of the process, while maximizing the economic returns to the installation of an aquaculture operation. Full article
(This article belongs to the Special Issue Ground Penetrating Radar (GPR): Theory, Methods and Applications)
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<p>Study area: (<b>a</b>) Brazil showing the state of Pará (hatched area) and the location of the two study sites (blue and green dots) within the municipalities of Tracuateua (green shading) (<b>b</b>) and Bragança (black shading) (<b>c</b>).</p> Full article ">Figure 2
<p>Flowchart of the methods employed in the present study.</p> Full article ">Figure 3
<p>Area 1 (Bragança, Pará), on which an aquaculture research center (CEANPA) is under construction, showing the geophysical profiles (<b>a</b>) and the location of the ponds (<b>b</b>) (modified from [<a href="#B56-applsci-13-11107" class="html-bibr">56</a>]).</p> Full article ">Figure 4
<p>Area 2 (Tracuateua, Pará): a privately-owned aquaculture facility (modified from [<a href="#B56-applsci-13-11107" class="html-bibr">56</a>]).</p> Full article ">Figure 5
<p>The GPR profiles (200 MHz antenna with a 200 ns time window) recorded in Area 1 (Bragança): (<b>a</b>) AB; (<b>b</b>) BC; (<b>c</b>) CD; (<b>d</b>) EF.</p> Full article ">Figure 6
<p>Map of the apparent conductivity recorded in Area 1 (Bragança), with a Horizontal Dipole (HD) and antennas with a 10 m interval between coils.</p> Full article ">Figure 7
<p>The GPR profiles (200 MHz antenna with a 200 ns time window) recorded in Area 2 (Tracuateua): (<b>a</b>) AB; (<b>b</b>) CD.</p> Full article ">Figure 8
<p>Map of the apparent conductivity recorded in Area 2 (Tracuateua), with a Horizontal Dipole (HD) and antennas with a 10m interval between coils.</p> Full article ">Figure 9
<p>Aquaculture operations in Area 1: (<b>a</b>) Installations; (<b>b</b>) Demarcation of the ponds; (<b>c</b>–<b>f</b>) Excavated ponds.</p> Full article ">Figure 10
<p>The maximum depth of the ponds excavated in Area 1.</p> Full article ">
11 pages, 4373 KiB  
Article
Reduction of Satellite Signature Effect in High-Accuracy Satellite Laser Ranging to Etalon
by Ning An, Bowen Guan, Natalia Edith Nunez, Jian Gao, Xue Dong, Haitao Zhang and Ricardo Cesar Podesta
Appl. Sci. 2023, 13(19), 11106; https://doi.org/10.3390/app131911106 - 9 Oct 2023
Viewed by 1252
Abstract
Etalon is considered to be one of the most promising satellites for studying crustal motions, Earth rotation, and other scientific applications. Unfortunately, its outsized shape and signature result in a measurement range bias of several millimeters. On the basis of simulations of the [...] Read more.
Etalon is considered to be one of the most promising satellites for studying crustal motions, Earth rotation, and other scientific applications. Unfortunately, its outsized shape and signature result in a measurement range bias of several millimeters. On the basis of simulations of the echo signals, we analyze the center of mass corrections (CoM) for Etalon due to variations in satellite signature effect at different incidence angles. To minimize range bias caused by satellite signature effects, a center of mass corrections filter has been proposed for the processing of standard SLR data. According to the relationship between RMS of CoM and the upper limits of the rejection criteria, the measurements with the lowest variability of CoM are selected for normal points. Statistics indicate that the center of mass corrections filter can improve the stability of the collected data by 79%, and reduce the mean RMS of normal points from 163.7 × 41.8 ps to 118.2 × 8.94 ps. Additionally, the new algorithm is applicable to Etalon-2. In particular, this paper enriches and provides a useful reference for minimizing the effects of satellite signatures on the production of SLR data by providing a theoretical model that incorporates systematic errors in SLR. Full article
(This article belongs to the Section Aerospace Science and Engineering)
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<p>Arrangement of corner cube reflectors installed on the surface of Etalon.</p> Full article ">Figure 2
<p>Distribution of laser reflection intensity of Etalon satellite angular reflector in different incident directions.</p> Full article ">Figure 3
<p>Distribution of the returned signals from Etalon at different incident angles.</p> Full article ">Figure 4
<p>Distribution of the returned signals from Etalon at different incident angles. The orange curve corresponds to the simulated echo signal based on the retroreflector uneven distribution model.</p> Full article ">Figure 5
<p>Variation of the center of mass corrections with incident angles.</p> Full article ">Figure 6
<p>Relationship between RMS of CoM and clipping location of the range residual distribution for normal points.</p> Full article ">Figure 7
<p>The diagram of the new proposed SLR algorithm.</p> Full article ">Figure 8
<p>Etalon-1 satellite data processing results (<b>a</b>) RMS of NPT, (<b>b</b>) skewness of NPT, (<b>c</b>) kurtosis of NPT.</p> Full article ">Figure 9
<p>Etalon-2 satellite data processing results (<b>a</b>) RMS of NPT, (<b>b</b>) skewness of NPT, (<b>c</b>) kurtosis of NPT.</p> Full article ">Figure 9 Cont.
<p>Etalon-2 satellite data processing results (<b>a</b>) RMS of NPT, (<b>b</b>) skewness of NPT, (<b>c</b>) kurtosis of NPT.</p> Full article ">Figure 10
<p>Residual distribution of Etalon-1/2 processed by different SLR algorithms: (<b>a</b>) Etalon-1; (<b>b</b>) Etalon-2.</p> Full article ">Figure A1
<p>Changchun SLR system diagram.</p> Full article ">
14 pages, 6965 KiB  
Article
Enhancing Oil Recovery and Altering Wettability in Carbonate Reservoir Rocks through (3-Glycidoxypropyl)trimethoxysilane–SiO2 Nanofluid Injection
by Hochang Jang and Jeonghwan Lee
Appl. Sci. 2023, 13(19), 11105; https://doi.org/10.3390/app131911105 - 9 Oct 2023
Cited by 1 | Viewed by 1401
Abstract
This study analyzes the impact of injection condition design factors of (3-glycidoxypropyl)trimethoxysilane (GPTMS)–SiO2 nanofluid on improving wettability and oil recovery through flotation and core flooding tests, respectively. Flotation tests were conducted to assess improvements in wettability that resulted from varying nanoparticle concentration, [...] Read more.
This study analyzes the impact of injection condition design factors of (3-glycidoxypropyl)trimethoxysilane (GPTMS)–SiO2 nanofluid on improving wettability and oil recovery through flotation and core flooding tests, respectively. Flotation tests were conducted to assess improvements in wettability that resulted from varying nanoparticle concentration, reaction time, and treatment temperature. The test results demonstrated that the hydrophilic sample ratio increased by up to 97.75% based on the nanoparticle reaction, confirming significant wettability improvement in all samples. Additionally, time-dependent fluid-flow experiments were conducted to validate oil recovery and rock–fluid interactions. In these experiments, for a 24-h reaction time, nanofluid injection caused a decrease in the maximum contact angle (43.4° from 166.5°) and a remarkable enhancement in the oil recovery rate by over 25%. Moreover, variations in contact angle and sample permeability were observed as the reaction time increased. Subsequently, the core flooding test revealed a critical reaction time of 24 h, maximizing oil recovery while minimizing permeability. Below this point in time, wettability improvement did not significantly enhance oil recovery. Conversely, beyond this threshold, additional adsorption due to particle aggregation decreased permeability, causing reduced oil recovery. Therefore, GPTMS–SiO2 nanofluid can be utilized as an injection fluid to enhance oil recovery in high-temperature and high-salinity carbonate reservoirs. Full article
(This article belongs to the Special Issue Petroleum Engineering: Production Forecasting, Process Design, and Implementation)
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<p>Preparation process for the nanofluid composed of surface-modified nanoparticles.</p> Full article ">Figure 2
<p>Flotation test processes: (<b>a</b>) Addition of the rock powder into a test tube. (<b>b</b>) Oil-aging of the rock powder in an oven for 2 days at 75 °C. (<b>c</b>) Vigorous mixing of the mixture with nanofluid and then placing in an oven for 1 day, causing oil-wet particles to float, whereas water-wet particles settle. (<b>d</b>) Removal of the oil phase and oil-wet particles, leaving the water-wet particles for cleaning, drying, and weighing (reproduced with permission from Sadeghi et al. [<a href="#B16-applsci-13-11105" class="html-bibr">16</a>]).</p> Full article ">Figure 3
<p>Schematic of the core flooding system for the EOR process using nanofluid.</p> Full article ">Figure 4
<p>FTIR spectra for unmodified and surface-modified SNPs.</p> Full article ">Figure 5
<p>Floatation test results of rock powder with limestone (left) and dolomite (right). (<b>a</b>,<b>b</b>) Effects of nanoparticle concentrations. The oil phase and oil-wet particles are removed, leaving the water-wet particles. (<b>c</b>,<b>d</b>) Effects of reaction time. The mixture is vigorously mixed with brine and then placed in the oven for 1 day, causing the oil-wet particles to float, whereas the water-wet particles settle. (<b>e</b>,<b>f</b>) The effects of treatment temperature are similar to those of reaction time.</p> Full article ">Figure 6
<p>Effect of particle concentrations of SNPs on flotation test results.</p> Full article ">Figure 7
<p>Effect of reaction time on flotation test results.</p> Full article ">Figure 8
<p>Effect of treatment temperature on flotation test results.</p> Full article ">Figure 9
<p>Oil recovery and differential pressure (<b>left</b>) during the core flooding test, and contact angles (<b>right</b>) in pre- and post-treatment at a reaction time of 12 h.</p> Full article ">Figure 10
<p>Oil recovery and differential pressure (<b>left</b>) during the core flooding test, and contact angles (<b>right</b>) in pre- and post-treatment at a reaction time of 24 h.</p> Full article ">Figure 11
<p>Oil recovery and differential pressure (<b>left</b>) during the core flooding test, and contact angles (<b>right</b>) in pre- and post-treatment at a reaction time of 48 h.</p> Full article ">Figure 12
<p>Oil recovery and differential pressure (<b>left</b>) during the core flooding test, and contact angles (<b>right</b>) in pre- and post-treatment after a reaction time of 72 h.</p> Full article ">
20 pages, 753 KiB  
Article
The Impact of Data Pre-Processing on Hate Speech Detection in a Mix of English and Hindi–English (Code-Mixed) Tweets
by Khalil Al-Hussaeni, Mohamed Sameer and Ioannis Karamitsos
Appl. Sci. 2023, 13(19), 11104; https://doi.org/10.3390/app131911104 - 9 Oct 2023
Cited by 2 | Viewed by 2108
Abstract
Due to the increasing reliance on social network platforms in recent years, hate speech has risen significantly among online users. Government and social media platforms face the challenging responsibility of controlling, detecting, and removing massively growing hateful content as early as possible to [...] Read more.
Due to the increasing reliance on social network platforms in recent years, hate speech has risen significantly among online users. Government and social media platforms face the challenging responsibility of controlling, detecting, and removing massively growing hateful content as early as possible to prevent future criminal acts, such as cyberviolence and real-life hate crimes. Twitter is used globally by people from various backgrounds and nationalities; it contains tweets posted in different languages, including code-mixed language, such as Hindi–English. Due to the informal format of tweets with variations in spelling and grammar, hate speech detection is especially challenging in code-mixed text. In this paper, we tackle the critical issue of hate speech detection on social media, with a focus on a mix of English and Hindi–English (code-mixed) text messages on Twitter. More specifically, we aim to evaluate the impact of data pre-processing on hate speech detection. Our method first performs 10-step data cleansing; then, it builds a detection method based on two architectures, namely a convolutional neural network (CNN) and a combination of CNN and long short-term Memory (LSTM) algorithms. We tune the hyperparameters of the proposed model architectures and conduct extensive experimental analysis on real-life tweets to evaluate the performance of the models in terms of accuracy, efficiency, and scalability. Moreover, we compare our method with a closely related hate speech detection method from the literature. The experimental results suggest that our method results in an improved accuracy and a significantly improved runtime. Among our best-performing models, CNN-LSTM improved accuracy by nearly 2% and decreased the runtime by almost half. Full article
(This article belongs to the Special Issue Deep Learning for Speech Processing)
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<p>Flowchart of the proposed method.</p> Full article ">Figure 2
<p>Character-level CNN architecture.</p> Full article ">Figure 3
<p>Character-level CNN-LSTM architecture.</p> Full article ">Figure 4
<p>Evaluation metrics for 50 epochs of training and testing with 3 convolutional layers of 256 filters, 2 dense layers of 512 neurons, and dropout rate of 0.5 using imbalanced training dataset: (<b>a</b>) Accuracy and (<b>b</b>) Loss.</p> Full article ">Figure 5
<p>Evaluation metric for 50 epochs of training and testing with 3 convolutional layers of 256 filters, 2 dense layers of 512 neurons, and dropout rate of 0.5 using over-sampled training dataset: (<b>a</b>) Accuracy and (<b>b</b>) Loss.</p> Full article ">Figure 6
<p>Evaluation metrics for 50 epochs of training and testing with 3 convolution layers of 256 filters, 1 LSTM layer of 100 neurons, and dropout rate of 0.2 using imbalanced training dataset: (<b>a</b>) Accuracy and (<b>b</b>) Loss.</p> Full article ">Figure 7
<p>Evaluation metrics for 50 epochs of training and testing with 3 convolution layers of 256 filters, 1 LSTM layer of 100 neurons, and dropout rate of 0.2 using over-sampled training dataset: (<b>a</b>) Accuracy and (<b>b</b>) Loss.</p> Full article ">Figure 8
<p>Accuracy comparison of different models.</p> Full article ">Figure 9
<p>Runtime comparison of different models.</p> Full article ">Figure 10
<p>Scalability comparison of different models.</p> Full article ">
38 pages, 2364 KiB  
Review
A Review of Transformer-Based Approaches for Image Captioning
by Oscar Ondeng, Heywood Ouma and Peter Akuon
Appl. Sci. 2023, 13(19), 11103; https://doi.org/10.3390/app131911103 - 9 Oct 2023
Cited by 5 | Viewed by 6349
Abstract
Visual understanding is a research area that bridges the gap between computer vision and natural language processing. Image captioning is a visual understanding task in which natural language descriptions of images are automatically generated using vision-language models. The transformer architecture was initially developed [...] Read more.
Visual understanding is a research area that bridges the gap between computer vision and natural language processing. Image captioning is a visual understanding task in which natural language descriptions of images are automatically generated using vision-language models. The transformer architecture was initially developed in the context of natural language processing and quickly found application in the domain of computer vision. Its recent application to the task of image captioning has resulted in markedly improved performance. In this paper, we briefly look at the transformer architecture and its genesis in attention mechanisms. We more extensively review a number of transformer-based image captioning models, including those employing vision-language pre-training, which has resulted in several state-of-the-art models. We give a brief presentation of the commonly used datasets for image captioning and also carry out an analysis and comparison of the transformer-based captioning models. We conclude by giving some insights into challenges as well as future directions for research in this area. Full article
(This article belongs to the Section Computing and Artificial Intelligence)
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<p>Transformers in image captioning: evolution from (<b>a</b>) traditional encoder-decoder-based captioning to (<b>b</b>) basic transformer-based captioning models to (<b>c</b>) captioning transformers based on vision-language pre-training.</p> Full article ">Figure 2
<p>Architecture of the captioning transformer with stacked attention modules and multi-level supervision.</p> Full article ">Figure 3
<p>Object relation transformer. Appearance and geometry features are extracted from the image based on the object detector’s regions.</p> Full article ">Figure 4
<p>Attention on attention model.</p> Full article ">Figure 5
<p>Overall architecture of the entangled transformer.</p> Full article ">Figure 6
<p>Architecture of the meshed-memory transformer. Multi-level encodings are connected to the decoder through a meshed and learnable connectivity. Each decoder layer inputs are controlled by a gating mechanism (<math display="inline"><semantics> <mi>σ</mi> </semantics></math>) that weights the multilevel contributions at each stage.</p> Full article ">Figure 7
<p>Simplified X-Linear Attention Network. The encoder and decoder utilize the X-Linear Attention Block. The decoder also relies on an LSTM. Decoder outputs at each time step therefore feed into the decoding operation of the next time step.</p> Full article ">Figure 8
<p>(<b>a</b>) The original transformer layer and (<b>b</b>) the widened encoding transformer layer of the image transformer. Each sub-transformer of the widened layer is responsible for a category of spatial relationship; all share the same query. <math display="inline"><semantics> <msub> <mo>Ω</mo> <mi>p</mi> </msub> </semantics></math>, <math display="inline"><semantics> <msub> <mo>Ω</mo> <mi>n</mi> </msub> </semantics></math> and <math display="inline"><semantics> <msub> <mo>Ω</mo> <mi>c</mi> </msub> </semantics></math> are the parent, neighbor and child node adjacency matrices.</p> Full article ">Figure 9
<p>General pipeline for self-supervised learning.</p> Full article ">Figure 10
<p>Unified VLP overview. The model is unified because the same multi-layer transformer network does the encoding and decoding; the same model is also fine-tuned for different downstream tasks, i.e., vision-language generation (image captioning) and understanding (VQA).</p> Full article ">Figure 11
<p>OSCAR overview. The object tags are used as anchor points to align image regions with word embeddings. The objective function is based on the masked token loss and a contrastive loss.</p> Full article ">Figure 12
<p>Ambiguous and overlapping region features from images with <span class="html-italic">couches</span> and <span class="html-italic">dogs</span>. In the semantic embedding space for images, there is a lot of overlap. The word embeddings on the other hand are more distinct. Multimodal alignment can help disambiguate the image semantic embeddings.</p> Full article ">
19 pages, 6524 KiB  
Article
Urban Tunnel Body Landscape Driving Comprehensive Evaluation Study Based on Biomass-Sensing Automobile Field Experiment
by Zhiting Li, Bo Liang and Mengdie Xu
Appl. Sci. 2023, 13(19), 11102; https://doi.org/10.3390/app131911102 - 9 Oct 2023
Cited by 2 | Viewed by 1199
Abstract
Previously, in regard to tunnel design and research, the focus was primarily on traffic capacity and safety requirements, with less consideration given to cave landscape design and its impacts on drivers. This study addressed this gap by proposing a comprehensive evaluation system for [...] Read more.
Previously, in regard to tunnel design and research, the focus was primarily on traffic capacity and safety requirements, with less consideration given to cave landscape design and its impacts on drivers. This study addressed this gap by proposing a comprehensive evaluation system for urban tunnel landscape driving based on the Analytic Hierarchy Process (AHP) theory. Considering the information and perception aspects of the driving process and the unique landscape characteristics of urban tunnels, we utilized the drivers’ perception of biomass as an index layer and performed a simulation using a machine learning algorithm. The proposed model was validated through vehicle field tests that were conducted in four urban tunnels along with a substantial amount of measured biomass data obtained during the experiments. The research demonstrated a strong correlation between the urban tunnel body landscape and the driving comprehensive index, particularly under relevant biomass conditions, which revealed the interactive relationship between urban tunnel body landscape design parameters and biomass. Furthermore, the study analyzed and proposed the impact degree of the urban tunnel body landscape on drivers’ biomass indicators, which offered valuable insights into designing tunnel body landscapes with consideration for biomass perception. Full article
(This article belongs to the Section Civil Engineering)
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<p>Construction steps of the comprehensive evaluation index system of the urban tunnel body landscape.</p> Full article ">Figure 2
<p>Hierarchical diagram of the evaluation system.</p> Full article ">Figure 3
<p>Flow chart of data collection.</p> Full article ">Figure 4
<p>Overview of the architecture.</p> Full article ">Figure 5
<p>PR curve.</p> Full article ">Figure 6
<p>AUC curve.</p> Full article ">Figure 7
<p>Feature importance.</p> Full article ">Figure 8
<p>Physiological data visualization.</p> Full article ">Figure 8 Cont.
<p>Physiological data visualization.</p> Full article ">Figure 9
<p>Model prediction results.</p> Full article ">Figure 10
<p>Global qualitative analysis of features.</p> Full article ">Figure 11
<p>Local qualitative analysis of features.</p> Full article ">Figure 12
<p>Physiological data visualization (Box Plot).</p> Full article ">
19 pages, 9835 KiB  
Article
Study on Mechanical Properties and Erosion Resistance of Self-Compacting Concrete with Different Replacement Rates of Recycled Coarse Aggregates under Dry and Wet Cycles
by Shan Liu, Fengxia Han, Shiqi Zheng, Songpu Gao and Guoxing Zhang
Appl. Sci. 2023, 13(19), 11101; https://doi.org/10.3390/app131911101 - 9 Oct 2023
Cited by 2 | Viewed by 1619
Abstract
Concrete that self-compacts is frequently utilized in engineering construction. Recycled coarse aggregate self-compacting concrete (RCASCC) is made by partially substituting recycled coarse aggregates (RCA) for natural coarse aggregates in order to conserve construction resources. This study examines the impact of linked sulfate erosion, [...] Read more.
Concrete that self-compacts is frequently utilized in engineering construction. Recycled coarse aggregate self-compacting concrete (RCASCC) is made by partially substituting recycled coarse aggregates (RCA) for natural coarse aggregates in order to conserve construction resources. This study examines the impact of linked sulfate erosion, dry and wet cycles, and RCA replacement rates of 0%, 25%, 50%, 75%, and 100% on the mechanical properties and durability of RCASCC. By using the mass loss rate, relative dynamic elastic modulus, corrosion resistance factor, X-ray diffraction (XRD), scanning electron microscope (SEM), and atomic force microscope (AFM) analyses, as well as other macroscopic and microscopic methods, it is possible to examine the deterioration patterns of RCASCC under dry and wet cycles. The results demonstrate that the addition of RCA has a notable impact on concrete’s resistance to sulfate attack during both dry and wet cycles. The erosion products steadily rise, the interfacial transition zone (ITZ) becomes rougher, and the sulfate resistance falls as the replacement rate of RCA rises. According to the findings of SiO2, AFt, and CaCO3, the examination of corrosion products from XRD and microstructure from SEM and EDS is carried out. The old mortar that has adhered to the surface of RCA, as shown by the AFM analysis of ITZ and the SEM analysis of RCA, can significantly affect the roughness of ITZ inside RCASCC. Full article
(This article belongs to the Special Issue Advanced Concrete Technology and Applications in Construction Engineering)
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<p>WHY-3000 automatic pressure testing machine.</p> Full article ">Figure 2
<p>Compressive strength with different RCA replacement ratios and 7/28-day strength ratio.</p> Full article ">Figure 3
<p>Appearance of prismatic specimens after erosion. (<b>a</b>) RCASCC-0. (<b>b</b>) RCASCC-25. (<b>c</b>) RCASCC-50. (<b>d</b>) RCASCC-75. (<b>e</b>) RCASCC-100.</p> Full article ">Figure 4
<p>Mass loss rate of self-compacting concrete with recycled aggregates.</p> Full article ">Figure 5
<p>Relative dynamic modulus of elasticity of self-compacting concrete with recycled aggregates.</p> Full article ">Figure 6
<p>Corrosion resistance factor of recycled aggregate self-compacting concrete.</p> Full article ">Figure 7
<p>Microscopic test samples.</p> Full article ">Figure 8
<p>XRD results of RCASCC at the end of 120 wet and dry cycles. (<b>a</b>) RCASCC-0. (<b>b</b>) RCASCC-25. (<b>c</b>) RCASCC-50. (<b>d</b>) RCASCC-75. (<b>e</b>) RCASCC-100.</p> Full article ">Figure 8 Cont.
<p>XRD results of RCASCC at the end of 120 wet and dry cycles. (<b>a</b>) RCASCC-0. (<b>b</b>) RCASCC-25. (<b>c</b>) RCASCC-50. (<b>d</b>) RCASCC-75. (<b>e</b>) RCASCC-100.</p> Full article ">Figure 9
<p>SEM results of RCASCC-0 at the end of 120 wet and dry cycles. (<b>a</b>) Early stage of C-S-H hydration. (<b>b</b>) C-S-H late stage of hydration.</p> Full article ">Figure 10
<p>SEM results of RCASCC-25 after the end of 120 wet and dry cycles. (<b>a</b>) Hydration product Ca(OH)<sub>2</sub>. (<b>b</b>) Internal structural cracks.</p> Full article ">Figure 11
<p>SEM results of RCASCC-50 at the end of 120 wet and dry cycles. (<b>a</b>) Erosion products and internal cracks. (<b>b</b>) Erosion products fill internal cracks.</p> Full article ">Figure 12
<p>SEM results of RCASCC-25 after the end of 120 wet and dry cycles. (<b>a</b>) Pin cluster erosion products. (<b>b</b>) EDS energy spectrum point sweep analysis. (<b>c</b>) Pin-columnar erosion products. (<b>d</b>) EDS energy spectrum point sweep analysis.</p> Full article ">Figure 13
<p>SEM results of RCASCC-100 at the end of 120 wet and dry cycles. (<b>a</b>) Surface structure of concrete after erosion. (<b>b</b>) Concrete surface erosion products.</p> Full article ">Figure 14
<p>Changes in the transition zone of RCASCC interface under 120 wet and dry cycles. (<b>a</b>) RCASCC-0. (<b>b</b>) RCASCC-25. (<b>c</b>) RCASCC-50. (<b>d</b>) RCASCC-75. (<b>e</b>) RCASCC-100.</p> Full article ">Figure 14 Cont.
<p>Changes in the transition zone of RCASCC interface under 120 wet and dry cycles. (<b>a</b>) RCASCC-0. (<b>b</b>) RCASCC-25. (<b>c</b>) RCASCC-50. (<b>d</b>) RCASCC-75. (<b>e</b>) RCASCC-100.</p> Full article ">
21 pages, 5497 KiB  
Article
CIPSO-Based Decision Support Method for Collision Avoidance of Super-Large Vessel in Port Waters
by Bo Xiang and Yongqiang Zhuo
Appl. Sci. 2023, 13(19), 11100; https://doi.org/10.3390/app131911100 - 9 Oct 2023
Viewed by 1405
Abstract
Effective and timely collision avoidance decision support is essential for super-large vessels navigating in port waters. To guarantee the navigational safety of super-large vessels, this work proposes a collision avoidance decision support method based on the curve increment strategy with adaptive particle swarm [...] Read more.
Effective and timely collision avoidance decision support is essential for super-large vessels navigating in port waters. To guarantee the navigational safety of super-large vessels, this work proposes a collision avoidance decision support method based on the curve increment strategy with adaptive particle swarm optimization (CIPSO). Firstly, the objective function is constructed based on the multi-objective optimization method. Here, a fuzzy comprehensive evaluation (FCE)-based vessel collision hazard model and vessel speed-varying energy-loss model integrating the Convention on the International Regulations for Preventing Collisions at Sea (COLREGS) are involved. Furthermore, in response to the limitations of the PSO algorithm, which is prone to falling into local optima in the later stages of iteration, a curve increment strategy is incorporated. To improve the performance of the global optimization, it is optimized using a local followed by global search method. The iterative evolution of CIPSO is used to obtain the optimal decision value in the set domain of feasible solutions. Finally, the effectiveness and feasibility of the proposed method are verified by the numerical simulation and large vessel maneuvering simulator, which can provide collision avoidance decision support for ship pilots. Full article
(This article belongs to the Special Issue Maritime Transportation System and Traffic Engineering Oriented for the New Generation of Waterborne Transportation Systems)
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<p>Flowchart of the collision avoidance decision support method.</p> Full article ">Figure 2
<p>KIJIMA ship domain model.</p> Full article ">Figure 3
<p>Curve incremental strategy function.</p> Full article ">Figure 4
<p>Optimization steps of CIPSO algorithm.</p> Full article ">Figure 5
<p>Simulation of the trajectory of each vessel in the experiment.</p> Full article ">Figure 6
<p>Comparison of the change in the CRI of TG relative to OS in two collision avoidance operations.</p> Full article ">Figure 7
<p>Comparison of <span class="html-italic">d<sub>CPA</sub></span> and <span class="html-italic">t<sub>CPA</sub></span> value changes between TG and OS in two collision avoidance operations. (<b>a</b>) The change of <span class="html-italic">d<sub>CPA</sub></span> value; (<b>b</b>) The change of <span class="html-italic">t<sub>CPA</sub></span> value.</p> Full article ">Figure 8
<p>Comparison diagram of fitness changes.</p> Full article ">Figure 9
<p>Change curve of CRI in the collision avoidance process.</p> Full article ">Figure 10
<p>Change the curve of encounter distance between OS and each TG.</p> Full article ">Figure 11
<p>Simulation test on the motion trajectories of each vessel.</p> Full article ">Figure 12
<p>Changes in <span class="html-italic">d<sub>CPA</sub></span> and <span class="html-italic">t<sub>CPA</sub></span> values of the simulation test vessel.(<b>a</b>) The change of <span class="html-italic">d<sub>CPA</sub></span> value; (<b>b</b>) The change of <span class="html-italic">t<sub>CPA</sub></span> value.</p> Full article ">
15 pages, 6304 KiB  
Article
Study on Mechanical Properties of Deep Expansive Soil and Coupling Damage Model of Freeze–Thaw Action and Loading
by Zhuliang Zhu, Bin Lin and Shiwei Chen
Appl. Sci. 2023, 13(19), 11099; https://doi.org/10.3390/app131911099 - 9 Oct 2023
Viewed by 1305
Abstract
This study is primarily intended to present a damage constitutive equation under the combined action of confining pressures and freeze–thaw cycles by subjecting deep expansive clay to the consolidated undrained triaxial tests. We study the influence of the numbers of freeze–thaw cycles on [...] Read more.
This study is primarily intended to present a damage constitutive equation under the combined action of confining pressures and freeze–thaw cycles by subjecting deep expansive clay to the consolidated undrained triaxial tests. We study the influence of the numbers of freeze–thaw cycles on various mechanical indexes of soil by using the TSZ-2 instrument (fully automatic triaxial instrument). As the number of freeze–thaw cycles increases, the ultimate peak stress of the soil decreases, and then, the effect of the freeze–thaw effect on the shear strength gradually weakened. By combining the expression method of the damage variable under the action of loading alone with the expression method under the action of freeze–thaw cycles alone, we brought in the damage evolution equation to obtain the damage constitutive equation under the combined action of confining pressures and freeze–thaw cycles. The stress values under three confining pressures (100 kPa, 200 kPa, and 300 kPa) can be determined by using the final damage constitutive model. The measured data with a water content of 17% and six freeze–thaw cycles were compared with the theoretical data. The actual strength values were 118.4 kPa, 152.3 kPa, and 184.1 kPa, and the theoretical strength values were 120 kPa, 150 kPa, and 186 kPa. The fitting degree of the strength value was as high as 99%, which verifies the feasibility of this model. This study can serve as an available reference for well wall construction and disaster prediction in deep coal mining. Full article
(This article belongs to the Topic Geotechnics for Hazard Mitigation)
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<p>Schematic diagram of triaxial shear test under freeze–thaw cycles.</p> Full article ">Figure 2
<p>The stress–strain curve under different moisture contents: (<b>a</b>) ω =14%, (<b>b</b>) ω = 17%, (<b>c</b>) ω = 21%, and (<b>d</b>) ω = 24%.</p> Full article ">Figure 3
<p>Stress–strain curves under different numbers of freeze–thaw cycles: (<b>a</b>) 0 time, (<b>b</b>) 3 times, (<b>c</b>) 6 times, (<b>d</b>) 9 times, and (<b>e</b>) 12 times.</p> Full article ">Figure 4
<p>The relationship between compressive strength and number of freeze–thaw cycles.</p> Full article ">Figure 5
<p>The Mohr stress circle under different numbers of freeze–thaw cycles: (<b>a</b>) 0 time, (<b>b</b>) 3 times, (<b>c</b>) 6 times, (<b>d</b>) 9 times, and (<b>e</b>) 12 times.</p> Full article ">Figure 6
<p>The change diagram of mechanical index with the number of freeze–thaw cycles. (<b>a</b>) The cohesion, (<b>b</b>) The internal friction angle.</p> Full article ">Figure 7
<p>The comparison of the damage theoretical curve and test curve of deep expansive clay under different confining pressures. (<b>a</b>) 100 kPa, (<b>b</b>) 200 kPa, and (<b>c</b>) 300 kPa.</p> Full article ">
17 pages, 4439 KiB  
Article
Exploring the ViDiDetect Tool for Automated Defect Detection in Manufacturing with Machine Vision
by Mateusz Dziubek, Jacek Rysiński and Daniel Jancarczyk
Appl. Sci. 2023, 13(19), 11098; https://doi.org/10.3390/app131911098 - 9 Oct 2023
Cited by 4 | Viewed by 2574
Abstract
Automated monitoring of cutting tool wear is of paramount importance in the manufacturing industry, as it directly impacts production efficiency and product quality. Traditional manual inspection methods are time-consuming and prone to human error, necessitating the adoption of more advanced techniques. This study [...] Read more.
Automated monitoring of cutting tool wear is of paramount importance in the manufacturing industry, as it directly impacts production efficiency and product quality. Traditional manual inspection methods are time-consuming and prone to human error, necessitating the adoption of more advanced techniques. This study explores the application of ViDiDetect, a deep learning-based defect detection solution, in the context of machine vision for assessing cutting tool wear. By capturing high-resolution images of machining tools and analyzing wear patterns, machine vision systems offer a non-contact and non-destructive approach to tool wear assessment, enabling continuous monitoring without disrupting the machining process. In this research, a smart camera and an illuminator were utilized to capture images of a car suspension knuckle’s machined surface, with a focus on detecting burrs, chips, and tool wear. The study also employed a mask to narrow the region of interest and enhance classification accuracy. This investigation demonstrates the potential of machine vision and ViDiDetect in automating cutting tool wear assessment, ultimately enhancing manufacturing processes’ efficiency and product quality. The project is at the implementation stage in one of the automotive production plants located in southern Poland. Full article
(This article belongs to the Special Issue Application of Machine Vision and Deep Learning Technology)
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<p>Smart camera Cognex In-Sight D900M [<a href="#B36-applsci-13-11098" class="html-bibr">36</a>].</p> Full article ">Figure 2
<p>Cognex LEC-59870 Edmund Optics lens [<a href="#B38-applsci-13-11098" class="html-bibr">38</a>].</p> Full article ">Figure 3
<p>ODS75 OverDrive™ Brick Light illuminator [<a href="#B39-applsci-13-11098" class="html-bibr">39</a>].</p> Full article ">Figure 4
<p>Car steering knuckle with machined surfaces for tool wear testing.</p> Full article ">Figure 5
<p>Selected machined surface for testing—brake caliper (marked in red).</p> Full article ">Figure 6
<p>Detailed photos taken with a service life of 170–200 tool cycles.</p> Full article ">Figure 7
<p>Detailed photos taken just after changing the cutting tool.</p> Full article ">Figure 8
<p>Vision system installed on the transport line of car knuckles.</p> Full article ">Figure 9
<p>Spreadsheet view and details within the found surface (TrainPatMaxRedLine tool in cell B7).</p> Full article ">Figure 10
<p>Results of defect recognition on the tested surface—first attempt.</p> Full article ">Figure 11
<p>The result of applying a mask to the learned image—visible detection of defects at the edges of the surface.</p> Full article ">Figure 12
<p>A selected example of neural network classification results after applying a mask.</p> Full article ">
12 pages, 4957 KiB  
Article
Augmented Reality-Assisted Surgical Exposure of an Impacted Tooth: A Pilot Study
by Monica Macrì, Giuseppe D’Albis, Vincenzo D’Albis, Simona Timeo and Felice Festa
Appl. Sci. 2023, 13(19), 11097; https://doi.org/10.3390/app131911097 - 9 Oct 2023
Cited by 5 | Viewed by 1553
Abstract
Three-dimensional radiological evaluation through cone beam computer tomography is essential in diagnosing and establishing proper surgical management in impacted teeth. Through Augmented Reality (AR), clinicians have the opportunity to use three-dimensional computer-generated radiologic information to visualise the patient and simultaneously the superimposition of [...] Read more.
Three-dimensional radiological evaluation through cone beam computer tomography is essential in diagnosing and establishing proper surgical management in impacted teeth. Through Augmented Reality (AR), clinicians have the opportunity to use three-dimensional computer-generated radiologic information to visualise the patient and simultaneously the superimposition of his internal structures. Here, we describe a digital workflow to assist the oral surgeon in pre-orthodontic exposure of a vestibular impacted canine using AR. The AR hardware consists of a camera and a traditional stand-up monitor. The registration and tracking are video-based and marker-free, with an automatic pose estimation obtained through VisLab 20.10.1AR software algorithm’s object recognition and tracking approach. A 3D model is created by combining the anterior teeth taken from the intraoral scan with the same teeth plus the included tooth taken from the CBCT segmentation. The 3D file is uploaded into the AR software. Model tracking is straightforward to set up without prior registration of targets or surroundings. The AR information is used successfully to define the surgical access to perform flap and osteotomy. The accuracy of model tracking matching was calculated constantly by the software. During the tracking, the process recorded an inlier ratio of 0.39:0.48. Further studies and clinical trials will evaluate the value of this novel technology in the management of impacted teeth. Full article
(This article belongs to the Special Issue Computer Methods in Mechanical, Civil and Biomedical Engineering)
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<p>Digital project of the trans-palatal bar and mini-screws.</p> Full article ">Figure 2
<p>Intraoral view after insertion of computer-guided mini-screws.</p> Full article ">Figure 3
<p>Edited optical intraoral scan.</p> Full article ">Figure 4
<p>Three-dimensional imaging reconstructions based on a sequence of two-dimensional DICOM files acquired with cone beam computer tomography (Carica Dati: Upload Data; Seleziona l’area interessata: Select the interested area; Configura la superficie 3D: Configure 3D surface; Strato assiale: Axial plane; Strato sagittale: Sagittal plane; Strato coronale: Coronal plane; Sx: Left; Dx: Right).</p> Full article ">Figure 5
<p>Edited 3D model exported from the 3D reconstruction software.</p> Full article ">Figure 6
<p>Application of landmarks for the superimposition process in CAD-CAM software. Points 1, 2, 3, 4, 5, 6 represent the points marked to perform the matching (Numero punti: Number of points; Traccia punto su ogg. in mov.: Track point on moving object).</p> Full article ">Figure 7
<p>A three-dimensional final model containing the intraoral scan end of the endosseous position of the crown of the impacted teeth.</p> Full article ">Figure 8
<p>The graphical user interface of AR software: preoperative calibration.</p> Full article ">Figure 9
<p>Setup of the Augmented Reality in the operating room.</p> Full article ">Figure 10
<p>Pre-operatory evaluation in Augmented Reality view after alignment of the digital model in the operatory field.</p> Full article ">Figure 11
<p>Surgical exposure and bonding of the impacted canine.</p> Full article ">Figure 12
<p>Failed alignment attempt for the view in AR of a 3D model containing the roots of the teeth adjacent to the impacted tooth.</p> Full article ">Figure 13
<p>Interruption of object tracking and consequent displacement of the 3D model caused by the patient’s movement.</p> Full article ">
18 pages, 11113 KiB  
Article
Effect of Wheel Path in Raster Grinding on Surface Accuracy of an Off-Axis Parabolic Mirror
by Jianhe Li, Honggang Li, Xiaoguang Guo, Renke Kang and Shang Gao
Appl. Sci. 2023, 13(19), 11096; https://doi.org/10.3390/app131911096 - 9 Oct 2023
Cited by 1 | Viewed by 1347
Abstract
Off-axis parabolic mirrors have extensive applications in X-ray optics, with the precision of their curvature directly impacting grazing-incidence focusing performance. Notably, the off-axis parabolic surface has non-rotating and non-symmetrical characteristics. Ultra-precision raster grinding utilizing a diamond wheel is a common method. Crucially, establishing [...] Read more.
Off-axis parabolic mirrors have extensive applications in X-ray optics, with the precision of their curvature directly impacting grazing-incidence focusing performance. Notably, the off-axis parabolic surface has non-rotating and non-symmetrical characteristics. Ultra-precision raster grinding utilizing a diamond wheel is a common method. Crucially, establishing an optimal wheel path stands as the key to ensuring surface accuracy during off-axis paraboloid grinding. In this study, according to the double curvature property of an off-axis parabolic surface, two different wheel paths were compared: one tracing the meridian direction (parabolic generatrix) and the other following the arc vector direction (arc). The results showed that the wheel path in raster grinding stepping along the arc vector direction can obtain a smaller scallop height and higher surface accuracy. The surface accuracy of one step along the arc vector direction is 9.6 μm, and that of the other step along the meridian direction is 32.6 μm. A model of the scallop height was established based on the relative relationship between adjacent wheel paths, and the error is within 5%. According to the correlation between scallop height and shape error, we conducted an analysis of the spatial distribution of shape errors under varying wheel paths. The wheel path that steps along the arc vector is more suitable for raster grinding of the off-axis paraboloid. The above study can provide theoretical guidance for the wheel path planning of off-axis parabolic mirrors with high surface accuracy. Full article
(This article belongs to the Special Issue Advances in Machining Process for Hard and Brittle Materials)
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<p>Schematic of off-axis parabolic surface.</p> Full article ">Figure 2
<p>Schematic of the raster path: (<b>a</b>) step along the meridian direction; (<b>b</b>) step along the arc vector direction.</p> Full article ">Figure 3
<p>Surface shape after grinding: (<b>a</b>) rough grinding surface: step along the meridian direction; (<b>b</b>) rough grinding surface: step along the arc vector direction; (<b>c</b>) finish grinding surface: step along the meridian direction; (<b>d</b>) finish grinding surface: step along the meridian direction.</p> Full article ">Figure 4
<p>The actual contour of scallop height: (<b>a</b>) step along the meridian direction; (<b>b</b>) step along the arc vector direction.</p> Full article ">Figure 5
<p>Surface roughness after grinding: (<b>a</b>) rough grinding surface morphology: step along the meridian direction; (<b>b</b>) rough grinding surface morphology: step along the arc vector direction; (<b>c</b>) finish grinding surface morphology: step along the meridian direction; (<b>d</b>) finish grinding surface morphology: step along the meridian direction.</p> Full article ">Figure 6
<p>Comparison between the measured surface and the theoretical surface: (<b>a</b>) step along the meridian direction; (<b>b</b>) step along the arc vector direction.</p> Full article ">Figure 7
<p>Schematic of the scallop height: (<b>a</b>) step along the meridian direction; (<b>b</b>) step along the arc vector direction.</p> Full article ">Figure 8
<p>Effect of grinding wheel radius <span class="html-italic">r</span> on scallop height.</p> Full article ">Figure 9
<p>Effect of step pitch <span class="html-italic">l</span> on scallop height.</p> Full article ">Figure 10
<p>Effect of workpiece curvature <span class="html-italic">R</span> on scallop height.</p> Full article ">Figure 11
<p>Comparison of actual and theoretical scallop height values.</p> Full article ">Figure 12
<p>Diagram of correlation between scallop height and surface shape error: (<b>a</b>) step along the meridian direction; (<b>b</b>) step along the arc vector direction.</p> Full article ">Figure 13
<p>Diagram of the surface error distribution of the raster path stepping along the meridian direction: (<b>a</b>) measurement; (<b>b</b>) simulation.</p> Full article ">Figure 14
<p>Diagram of the surface error distribution of the raster path stepping along the arc vector direction: (<b>a</b>) measurement; (<b>b</b>) simulation.</p> Full article ">Figure 15
<p>Diagram of the spatial distribution of the scallop height stepping along the meridian direction: (<b>a</b>) XOZ plane; (<b>b</b>) YOZ plane.</p> Full article ">Figure 16
<p>Diagram of the spatial distribution of the scallop height stepping along the arc vector direction: (<b>a</b>) YOZ plane; (<b>b</b>) XOZ plane.</p> Full article ">
17 pages, 6386 KiB  
Article
Research on Characteristics of Flow Noise and Flow-Induced Noise
by Bingru Li, Xudong Xu, Junhan Wu, Luomin Zhang and Zhanhong Wan
Appl. Sci. 2023, 13(19), 11095; https://doi.org/10.3390/app131911095 - 9 Oct 2023
Cited by 5 | Viewed by 2046
Abstract
The noise control of flank array sonar is a primary approach to enhance the sonar detection range. During submarine navigation, hydrodynamic noise is the main noise source in the platform region of the flank array sonar, which includes flow noise and flow-induced noise. [...] Read more.
The noise control of flank array sonar is a primary approach to enhance the sonar detection range. During submarine navigation, hydrodynamic noise is the main noise source in the platform region of the flank array sonar, which includes flow noise and flow-induced noise. Therefore, an in-depth investigation of hydrodynamic noise is necessary. In this paper, we firstly take the teardrop submarine as a computational model to validate the computational method. Afterwards, we numerically simulate the flow and flow-induced noise characteristics for the cylindrical shell model, and investigate differences in noise at different detection points along the X, Y, and Z axes. Finally, experiments are conducted to confirm the accuracy of the simulation results. The research findings reveal that, at the same frequency, flow-induced noise exceeds flow noise, and the noise decreases as the distance between the walls of the cylindrical shell increases. The experimental and simulation results are consistent, suggesting that the selected computational method can precisely simulate the submarine’s noise. Full article
(This article belongs to the Section Acoustics and Vibrations)
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<p>Mesh of the computational domain.</p> Full article ">Figure 2
<p>Pressure coefficient distribution of the computational model.</p> Full article ">Figure 3
<p>Cross-sectional velocity distribution of the computational model.</p> Full article ">Figure 4
<p>Sound pressure level comparison: (<b>a</b>) no. 1; (<b>b</b>) no. 3; (<b>c</b>) no. 5; (<b>d</b>) no. 8.</p> Full article ">Figure 4 Cont.
<p>Sound pressure level comparison: (<b>a</b>) no. 1; (<b>b</b>) no. 3; (<b>c</b>) no. 5; (<b>d</b>) no. 8.</p> Full article ">Figure 5
<p>Experimental and simulation models: (<b>a</b>) experimental model and (<b>b</b>) simulation model.</p> Full article ">Figure 6
<p>Simulation model and computational domain mesh: (<b>a</b>) simulation model mesh and (<b>b</b>) computational domain mesh.</p> Full article ">Figure 7
<p>Flow noise acoustic directivity diagram: (<b>a</b>) vertical section and (<b>b</b>) horizontal section.</p> Full article ">Figure 8
<p>Acoustic field around the shell.</p> Full article ">Figure 9
<p>Flow-induced noise sound pressure nephogram: (<b>a</b>) 201 Hz; (<b>b</b>) 244 Hz; (<b>c</b>) 302 Hz; (<b>d</b>) 450 Hz.</p> Full article ">Figure 10
<p>Flow-induced noise acoustic directivity diagram: (<b>a</b>) vertical section; (<b>b</b>) horizontal section.</p> Full article ">Figure 11
<p>Noise comparison diagram: (<b>a</b>) detection point X1; (<b>b</b>) detection point X11; (<b>c</b>) detection point Y1; (<b>d</b>) detection point Y11; (<b>e</b>) detection point Z1; (<b>f</b>) detection point Z11.</p> Full article ">Figure 12
<p>Comparison of sound pressure level: (<b>a</b>) X axis; (<b>b</b>) Y axis; (<b>c</b>) Z axis.</p> Full article ">Figure 13
<p>Experimental model: (<b>a</b>) cylindrical shell and (<b>b</b>) ballast body.</p> Full article ">Figure 14
<p>Schematic diagram of the experimental dragging.</p> Full article ">Figure 15
<p>Experimental arrangement: (<b>a</b>) experiment equipment; (<b>b</b>) schematic diagram of detection point layout. #1–#8 in (<b>b</b>) represent the location of the hydrophone detection points.</p> Full article ">Figure 16
<p>Frequency spectrum diagram: (<b>a</b>) no. 1 detection point; (<b>b</b>) no. 4 detection point.</p> Full article ">
15 pages, 4237 KiB  
Article
Intelligent Detection of Rebar Size and Position Using Improved DeeplabV3+
by Wei Chen, Xianglin Fu, Wanqing Chen and Zijun Peng
Appl. Sci. 2023, 13(19), 11094; https://doi.org/10.3390/app131911094 - 9 Oct 2023
Cited by 4 | Viewed by 2253
Abstract
For the development of reinforced concrete structures and infrastructure construction, traditional rebar checking and acceptance methods have shortcomings in terms of efficiency. The use of digital image processing technology cannot easily identify a rebar configuration with complex and diverse backgrounds. To solve this [...] Read more.
For the development of reinforced concrete structures and infrastructure construction, traditional rebar checking and acceptance methods have shortcomings in terms of efficiency. The use of digital image processing technology cannot easily identify a rebar configuration with complex and diverse backgrounds. To solve this problem, an inspection method combining deep learning and digital image processing techniques is proposed using an improved DeeplabV3+ model to identify reinforcing bars, with the identification results subjected to digital image processing operations to obtain the size information of the reinforcing bar. The proposed method was validated through a field test. The results of the experiment indicated that the proposed model is more accurate than other models, with a mean Intersection over Union (mIoU), precision, recall, and F1 score reaching 94.62%, 97.42%, 96.95%, and 97.18%, respectively. Moreover, the accuracy of the dimension estimations for the test reinforcements met the engineering acceptance standards. Full article
(This article belongs to the Special Issue Advanced Technologies in Construction and Infrastructure: Theory, Methods and Applications)
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<p>Structure of DeeplabV3+.</p> Full article ">Figure 2
<p>Structure of improved DeeplabV3+.</p> Full article ">Figure 3
<p>Schematic diagram of the residual blocks.</p> Full article ">Figure 4
<p>Efficient channel attention module.</p> Full article ">Figure 5
<p>Structure of the improved Resnet50.</p> Full article ">Figure 6
<p>Schematic of atrous spatial pyramid pooling (ASPP).</p> Full article ">Figure 7
<p>(<b>a</b>) Normal convolution; (<b>b</b>) atrous convolution.</p> Full article ">Figure 8
<p>Visualization of segmentation results of each model (the red circles and boxes in the figures represent inaccuracies in the segmentation results).</p> Full article ">Figure 8 Cont.
<p>Visualization of segmentation results of each model (the red circles and boxes in the figures represent inaccuracies in the segmentation results).</p> Full article ">Figure 9
<p>Schematic diagram of the diameter and spacing of rebar.</p> Full article ">
2 pages, 195 KiB  
Editorial
Special Issue on Propolis and Other Bee Products: Beneficial Effects on Health and Processing Technology
by Anna Kurek-Górecka, Anna Rzepecka-Stojko, Michał Górecki and Michał Otręba
Appl. Sci. 2023, 13(19), 11093; https://doi.org/10.3390/app131911093 - 9 Oct 2023
Cited by 1 | Viewed by 1177
Abstract
Bee products are some of the most useful natural products and are favoured by natural medicine scientists for their possible pluripotent nutritional and biotic applications [...] Full article
(This article belongs to the Special Issue Propolis and Other Bee Products: Beneficial Effects on Health and Processing Technology)
11 pages, 560 KiB  
Article
Physicochemical Properties, Antioxidant Capacities, and Sensory Evaluation of Yanggaeng Treated with Cissus quadrangularis
by Hyunsoo Jang, Jisu Lee, Sebin Won, Yeeun Kim, Miae Doo, Inyong Kim and Jung-Heun Ha
Appl. Sci. 2023, 13(19), 11092; https://doi.org/10.3390/app131911092 - 9 Oct 2023
Cited by 3 | Viewed by 1574
Abstract
This study investigated the impact of incorporating Cissus quadrangularis (CQ) powder into Yanggaeng, a traditional Korean food, focusing on its functional properties. This study examined the proximate composition, physicochemical characteristics, antioxidant capabilities, sensory attributes, and consumer preferences of Yanggaeng when treated with different [...] Read more.
This study investigated the impact of incorporating Cissus quadrangularis (CQ) powder into Yanggaeng, a traditional Korean food, focusing on its functional properties. This study examined the proximate composition, physicochemical characteristics, antioxidant capabilities, sensory attributes, and consumer preferences of Yanggaeng when treated with different levels (CON [0%], CQ2 [2%], CQ4 [4%], and CQ6 [6%]) of CQ powder. Yanggaeng with CQ powder exhibited a significantly reduced pH, and among the CQ additive groups the highest °Brix value was observed in CQ2. The water holding capacity (WHC) decreased after adding CQ powder. The color properties of Yanggaeng with CQ powder, including L*, a*, and b*, were measured. L* values dose-dependently decreased as the amount of CQ powder increased. Conversely, a* values increased significantly with CQ powder addition compared with CON, and b* values were highest in CQ2. Similarly, the browning index (BI) increased in the CQ powder treatment groups compared with CON. The antioxidative properties of Yanggaeng with CQ powder were evaluated by measuring the total phenolic content (TPC), total flavonoid content (TFC), 1,1-diphenyl-1-picrylhydrazyl (DPPH) and 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (ABTS) radical scavenging activities, and ferric reducing antioxidant power (FRAP). The antioxidant capacity dose-dependently increased with higher levels of CQ powder added. Regarding the texture profile of Yanggaeng, compared with the control group, adding CQ powder caused decreased hardness, gumminess, and chewiness. In consumer preference evaluations, CQ2 showed similarities to CON in all aspects (color, scent, flavor, sweetness, taste, chewiness, overall acceptance, and purchase intention). Therefore, incorporating CQ powder, a natural and edible antioxidative ingredient, into Yanggaeng may be acceptable to consumers despite significant changes in its physicochemical properties. Full article
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<p>Appearance of Yanggaeng treated with <span class="html-italic">C. quadrangularis</span> powder.</p> Full article ">
3 pages, 174 KiB  
Editorial
New Trends in Efficient Buildings
by Francesco Salamone, Lorenzo Belussi, Ludovico Danza, Francesco Guarino and Sonia Longo
Appl. Sci. 2023, 13(19), 11091; https://doi.org/10.3390/app131911091 - 9 Oct 2023
Viewed by 922
Abstract
The literature reports several examples wherein calculation methodologies for assessing the energy performance of buildings are proposed, and solutions to improve their performance are posited, along with the introduction of advanced technologies and algorithms to reach this goal [...] Full article
(This article belongs to the Special Issue New Trends in Efficient Buildings)
16 pages, 4600 KiB  
Article
The Development of a Novel Direct-Expansion Ground Source Heat Pump (DE-GSHP) for Embankment Heating in Cold Regions
by Mingxing Cao, Yimin Zhang and Tianfei Hu
Appl. Sci. 2023, 13(19), 11090; https://doi.org/10.3390/app131911090 - 9 Oct 2023
Viewed by 1402
Abstract
This study aimed to investigate the practical applications of a ground source heat pump (GSHP) system for heating applications in embankment engineering. A special direct-expansion GSHP (DE-GSHP) was designed and manufactured, and its performance was experimentally assessed. Subsequently, the newly developed DE-GSHP structure [...] Read more.
This study aimed to investigate the practical applications of a ground source heat pump (GSHP) system for heating applications in embankment engineering. A special direct-expansion GSHP (DE-GSHP) was designed and manufactured, and its performance was experimentally assessed. Subsequently, the newly developed DE-GSHP structure demonstrated an excellent heating performance with respect to positive heat-supplying temperatures in cold regions. The temperature could be automatically controlled at 30, 45, 60, and 75; additionally, the heat-absorbing temperatures were maintained below 0 °C, which was extremely lower than that of the deep frost-free stratum. Further, the experimental data were used to evaluate the coefficient of performance of the DE-GSHP, which was more than 3.5. The findings indicated that the GSHP has potential applications for embankment heating in cold regions. Full article
(This article belongs to the Section Civil Engineering)
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<p>Climate classification according to the feasibility of geothermal heat pumps for heating in China [<a href="#B18-applsci-13-11090" class="html-bibr">18</a>].</p> Full article ">Figure 2
<p>Schematic of the refrigerant circuit of the GSHP and a pressure–enthalpy graph of the GSHP. (<b>a</b>) The refrigerant circuit of the GSHP. (<b>b</b>) Pressure–enthalpy diagram. 1–2: Compression, 2–b: gas desuperheating, b–3: condensation, 3–4: throttling, and 4–1: evaporation.</p> Full article ">Figure 3
<p>Artificial heating embankment. (<b>a</b>) Helically coiled evaporator and helically coiled condenser, and (<b>b</b>) helically coiled evaporator and multi-U-tube condenser. 1. Compressor, 2. throttle valve, 3. helically coiled condenser, 4. helically coiled evaporator, 5. embankment, 6. ground base, and 7. multi-U-tube condenser.</p> Full article ">Figure 4
<p>Detailed structure of the DE-GHPA. 1. Condenser, 2. evaporator, 3. compressor, 4. throttle valve, 5. filter, 6. bracket, 7. bolt, 8. copper block, 9. power source, 10. automatic controller, 11. helically coiled tubes, 12. base tube, 13. retainers, 14. temperature sensor, and 15. signal line.</p> Full article ">Figure 5
<p>Artificial heating embankment.</p> Full article ">Figure 6
<p>Test conditions of the experimental facility. (<b>a</b>) Schematic representation (Unit: mm). (<b>b</b>) Experimental conditions.</p> Full article ">Figure 7
<p>Instantaneous heat-absorbing and heat-supplying temperatures observed during the tests (constant heat-supplying temperature of 30 °C).</p> Full article ">Figure 8
<p>Average heat-absorbing and heat-supplying temperatures during different operation modes.</p> Full article ">Figure 9
<p>Daily average temperatures during the heat exchange.</p> Full article ">Figure 10
<p>Temperature distributions of soil with the DE–GSHP. (<b>a</b>) 0 h. (<b>b</b>) 24 h.</p> Full article ">Figure 11
<p>Daily theoretical COP values during the tests.</p> Full article ">Figure 12
<p>Roadbed computational model.</p> Full article ">Figure 13
<p>Temperature fields in roadbed cross-section (Y = 20 m) on February 1. (<b>a</b>) Natural road base. (<b>b</b>) Heating temperature set point of 40 °C. (<b>c</b>) Heating temperature set point of 50 °C. (<b>d</b>) Heating temperature set point of 60 °C.</p> Full article ">Figure 14
<p>Variation pattern of freezing depth (Y = 20 m).</p> Full article ">
12 pages, 6144 KiB  
Article
Potential Synergistic Inhibition of Enterococcus faecalis by Essential Oils and Antibiotics
by Stanley John, Jeung Woon Lee, Purushottam Lamichhane, Thanhphuong Dinh, Todd Nolan and Thomas Yoon
Appl. Sci. 2023, 13(19), 11089; https://doi.org/10.3390/app131911089 - 9 Oct 2023
Viewed by 2215
Abstract
Recurrent infections after root canal treatments often involve Enterococcus faecalis, a microorganism closely associated with therapy failures due to its biofilm production, survival in nutrient-deprived conditions, and antibiotic tolerance. Essential oils (EOs), which display antimicrobial and antibacterial properties, exhibit inhibitory effects on [...] Read more.
Recurrent infections after root canal treatments often involve Enterococcus faecalis, a microorganism closely associated with therapy failures due to its biofilm production, survival in nutrient-deprived conditions, and antibiotic tolerance. Essential oils (EOs), which display antimicrobial and antibacterial properties, exhibit inhibitory effects on the growth of many microorganisms including E. faecalis. This study assessed the in vitro efficacy of combining 5% antibiotics (kanamycin 2.5 mg/mL, streptomycin 2.5 mg/mL, gentamicin 1.5 mg/mL, and ampicillin 5 mg/mL) with cinnamon (1.25% to 5%) or clove (25% and 50%) EOs in inhibiting the growth of E. faecalis, using disk diffusion tests. Disks were treated with EOs-only, antibiotics-only, or EO–antibiotic combinations, placed on BEA agar plates, and incubated for 24 h, and the zones of inhibition were measured. Results showed that EOs (cinnamon and clove) and 5% antibiotics, by themselves, had robust growth inhibition of E. faecalis across all tested concentrations. Moreover, combining 5% aminoglycosides (kanamycin 2.5 mg/mL, streptomycin 2.5 mg/mL, and gentamicin 1.5 mg/mL) with 5% cinnamon EO produced significantly enhanced antimicrobial effect than the corresponding 10% antibiotic solution alone. These findings suggest that combining cinnamon EO with aminoglycoside antibiotics can achieve significant inhibition of E. faecalis at a lower concentration of antibiotics compared to using a higher dose of antibiotics alone. Further in vivo studies should determine the safety, efficacy, and treatment duration, with the potential to reduce antibiotic dosages and associated toxicity while preventing recurrent infections. Full article
(This article belongs to the Special Issue Advances in Endodontics and Periodontics)
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<p>An image of BEA agar plate inoculated with <span class="html-italic">E. faecalis</span> showing the zones of inhibition of 5% gentamicin (1.5 mg/mL) combined with cinnamon 2.5% EO. The plate was incubated at 37 °C for 24 h and the size of zone of inhibition was measured using a ruler. BEA, Bile Esculin Azide; EO, essential oils.</p> Full article ">Figure 2
<p>Antimicrobial effects of EOs ((<b>A</b>), cinnamon and clove) and antibiotics (<b>B</b>) on <span class="html-italic">E. faecalis</span> were quantitated using the disk diffusion test. The cinnamon (1.25% to 5%) and clove (25% to 50%) EOs showed significantly graded responses in inhibiting the growth of <span class="html-italic">E. faecalis</span> (Panel (<b>A</b>)). The cinnamon EO showed stronger antimicrobial effect than clove EO at much lower concentrations. Each antibiotic was diluted to 5% and 10% concentrations that produced a ZOI similar to that of EOs (<b>B</b>). This paired antibiotic concentration was selected for the Antibiotic + EO combination experiment. All antibiotics showed significant increase in ZOI between the 5% and 10% concentrations. CN = cinnamon, CL = clove, EO = essential oil, K = kanamycin, S = streptomycin, G = gentamicin, and A = ampicillin. Different letters (a to e) above the columns indicate significant difference between the groups (<span class="html-italic">p</span> &lt; 0.005). * <span class="html-italic">p</span> &lt; 0.05 and ** <span class="html-italic">p</span> &lt; 0.005.</p> Full article ">Figure 3
<p>Enhanced and additive antimicrobial effects of antibiotics combined with cinnamon EO (solid red circle lines) in inhibiting the growth of <span class="html-italic">E. faecalis</span> in disk diffusion test. The dotted horizontal lines and shaded blue bars represent the average ZOI for 5% and 10% concentrations of antibiotics, and the solid squared lines represent ZOI for different concentrations of cinnamon EO alone. The kanamycin 2.5 mg/mL (5%) with CN5% (<b>A</b>) had significantly larger ZOI than its individual components (kanamycin 2.5 mg/mL or CN5% separately; dotted line and right solid square box) and kanamycin 5 mg/mL (10%). The streptomycin 2.5 mg/mL (5%) with CN5% (<b>B</b>) solution and gentamycin 1.5 mg/mL (5%) with CN5% (<b>C</b>) solution also produced significantly larger ZOI than their corresponding 10% antibiotics, CN5%, and 5% antibiotics separately. The ampicillin 5 mg/mL (5%) with CN5% (<b>D</b>) solution showed significantly larger ZOI only to its individual components but not to ampicillin 10 mg/mL (10%). #: <span class="html-italic">p</span> &lt; 0.05 vs. 5% antibiotic concentration and corresponding CN EO individually; &amp;: <span class="html-italic">p</span> &lt; 0.05 vs. 10% antibiotic concentration alone.</p> Full article ">Figure 4
<p>Antimicrobial effects of kanamycin (<b>A</b>), streptomycin (<b>B</b>), gentamicin (<b>C</b>) and ampicillin (<b>D</b>) combined with clove EO (solid red circles) in inhibiting the growth of <span class="html-italic">E. faecalis</span> in disk diffusion test. The dotted horizontal lines and shaded blue bars represent the average ZOI for 5% and 10% concentrations of antibiotics, and the solid squares represent ZOI for clove50% EO alone. Combining 5% concentration of antibiotics with CL50% did not produce any significant increase in ZOI compared to its individual components nor to 10% concentration of antibiotics against <span class="html-italic">E. faecalis</span>.</p> Full article ">
24 pages, 9109 KiB  
Article
Multi-Scale Flame Situation Detection Based on Pixel-Level Segmentation of Visual Images
by Xinzhi Wang, Mengyue Li, Quanyi Liu, Yudong Chang and Hui Zhang
Appl. Sci. 2023, 13(19), 11088; https://doi.org/10.3390/app131911088 - 9 Oct 2023
Viewed by 1810
Abstract
The accurate analysis of multi-scale flame development plays a crucial role in improving firefighting decisions and facilitating smart city establishment. However, flames’ non-rigid nature and blurred edges present challenges in achieving accurate segmentation. Consequently, little attention is paid to extracting further flame situation [...] Read more.
The accurate analysis of multi-scale flame development plays a crucial role in improving firefighting decisions and facilitating smart city establishment. However, flames’ non-rigid nature and blurred edges present challenges in achieving accurate segmentation. Consequently, little attention is paid to extracting further flame situation information through fire segmentation. To address this issue, we propose Flame-SeaFormer, a multi-scale flame situation detection model based on the pixel-level segmentation of visual images. Flame-SeaFormer comprises three key steps. Firstly, in the context branch, squeeze-enhanced axial attention (SEA attention) is applied to squeeze fire feature maps, capturing dependencies among flame pixels while reducing the computational complexity. Secondly, the fusion block in the spatial branch integrates high-level semantic information from the contextual branch with low-level spatial details, ensuring a global representation of flame features. Lastly, the light segmentation head conducts pixel-level segmentation on the flame features. Based on the flame segmentation results, static flame parameters (flame height, width, and area) and dynamic flame parameters (change rates of flame height, width, and area) are gained, thereby enabling the real-time perception of flame evolution behavior. Experimental results on two datasets demonstrate that Flame-SeaFormer achieves the best trade-off between segmentation accuracy and speed, surpassing existing fire segmentation methods. Flame-SeaFormer enables precise flame state acquisition and evolution exploration, supporting intelligent fire protection systems in urban environments. Full article
(This article belongs to the Special Issue Advanced Methodology and Analysis in Fire Protection Science)
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<p>Process of dealing with fire incidents.</p> Full article ">Figure 2
<p>Flame parameters trends during combustion. Based on two fire videos captured in the experimental scenario, flame parameters for both fire processes were computed. Similar to the sensor-based approach, flame parameters derived from visual data exhibit a three-stage combustion pattern. It is evident that the vision-based fire detection method can be extended to respond rapidly to real-world fire incidents.</p> Full article ">Figure 3
<p>Schematic diagram of experimental setup and flame parameters.</p> Full article ">Figure 4
<p>Overview of relevant research on fire segmentation.</p> Full article ">Figure 5
<p>The framework of multi-scale flame situation detection model Flame-SeaFormer. For input fire images, the SeaFormer model produces pixel-level segmentation results. Based on the segmentation results of fire video sequences, the flame parameter inversion section calculates static and dynamic flame parameters and then analyzes the development trends of the flames. Due to space limitations, only the trends of the flame static parameters of the five combustion processes are shown here.</p> Full article ">Figure 6
<p>Illustration of the three major modules in SeaFormer. (<b>a</b>) SeaFormer layer consists of SEA attention and an FFN. (<b>b</b>) Fusion block is utilized to fuse high-resolution fire feature maps in the spatial branch and low-resolution fire feature maps in the context branch. (<b>c</b>) Light segmentation head consists of two convolution layers.</p> Full article ">Figure 7
<p>Schematic illustration of SEA attention. SEA attention includes detail enhancement kernel and squeeze axial attention. The symbol ⊕ indicates an element-wise addition operation. Mul means multiplication.</p> Full article ">Figure 8
<p>Several images in FLAME dataset along with their corresponding segmentation results. The first row displays the original images, while the second row shows the segmentation results. Flame pixels are highlighted in green, while background pixels remain uncolored, consistent with the original image.</p> Full article ">Figure 9
<p>The <math display="inline"><semantics> <mrow> <mi>F</mi> <mi>P</mi> <mi>S</mi> </mrow> </semantics></math> results on the two datasets.</p> Full article ">Figure 10
<p>The <math display="inline"><semantics> <mrow> <mi>m</mi> <mi>I</mi> <mi>o</mi> <mi>U</mi> </mrow> </semantics></math> results of the three stages of flame combustion. (<b>a</b>) FCN vs. Flame-SeaFormer. (<b>b</b>) Unet vs. Flame-SeaFormer. (<b>c</b>) Deeplab v3+ vs. Flame-SeaFormer. (<b>d</b>) SegFormer vs. Flame-SeaFormer. (<b>e</b>) GMMSeg vs. Flame-SeaFormer.</p> Full article ">Figure 11
<p>Multi-scale flame segmentation results on Our_flame_smoke dataset. (<b>a</b>–<b>c</b>) represent the original image sequences of three burning processes, respectively. The next line of each sequence corresponds to the flame segmentation result. The flame pixels are highlighted in green, while the background pixels are uncolored and consistent with the original image.</p> Full article ">Figure 12
<p>Segmentation results of negative samples. (<b>a</b>–<b>d</b>) are four negative samples selected from two datasets, where (<b>a</b>,<b>b</b>) are from the Our_flame_smoke dataset. (<b>c</b>,<b>d</b>) are from the FLAME dataset. (<b>e</b>–<b>h</b>) are their corresponding segmentation results.</p> Full article ">Figure 13
<p>The static flame parameters of a flame in five videos.</p> Full article ">Figure 14
<p>Flame height on an FRNC N2XCH cable pre-heated to T = 191 <math display="inline"><semantics> <mrow> <msup> <mrow/> <mo>°</mo> </msup> <mi mathvariant="normal">C</mi> </mrow> </semantics></math>.</p> Full article ">Figure 15
<p>The dynamic flame parameters of a flame in five videos.</p> Full article ">Figure 16
<p>Variations in axial length under increasing velocity with time in ammonia/air mixture.</p> Full article ">
16 pages, 2056 KiB  
Article
Effect of Time of Girdling on Leaf Photosynthetic Performance and Kiwifruit Quality Characteristics at Harvest and Post-Storage
by Peter A. Roussos, Nikoleta-Kleio Denaxa, Athanassios Tsafouros and Efstathios Ntanos
Appl. Sci. 2023, 13(19), 11087; https://doi.org/10.3390/app131911087 - 9 Oct 2023
Cited by 1 | Viewed by 1761
Abstract
The present study investigated the impact of cane girdling on the ‘Hayward’ kiwifruit cultivar, both in terms of leaf physiological functions and fruit quality attributes, at harvest and post-storage. Four treatments were conducted: the control cane girdling conducted separately in August (GA), in [...] Read more.
The present study investigated the impact of cane girdling on the ‘Hayward’ kiwifruit cultivar, both in terms of leaf physiological functions and fruit quality attributes, at harvest and post-storage. Four treatments were conducted: the control cane girdling conducted separately in August (GA), in September (GS), and both in August and September (double girdling) (GAS), using different canes. The results indicated that the carbon assimilation rate was reduced in girdled canes. Nevertheless, girdling resulted in increased fruit dry matter (by 1.7%), weight (by 6.4%), and dimensions without altering fruit shape. Additionally, fruits produced on girdled canes exhibited higher total soluble solids content (by almost 13%) and TSS-to-TA ratio post-storage. There were no significant differences in chlorophyll and carotenoid concentrations, organic acids, and most sugars assessed, both at harvest and post-storage. There were no significant differences among the treatments at harvest regarding total phenolic compounds, except for total flavonoids, which were lowest in the GA treatment. Post-storage, girdling (especially GAS and GS) was found to enhance the fruits’ total phenols and total flavanols, as well as its antioxidant capacity (1.88 μmol equiv. Trolox g−1 FW based on DPPH assay under GS versus (0.53 μmol equiv. Trolox g−1 FW under control). Overall, cane girdling can improve the quality of kiwifruit in terms of both fruit size and functional fruit properties. Full article
(This article belongs to the Section Agricultural Science and Technology)
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<p>Cane appearance under control (<b>A</b>), single (<b>B</b>), and double girdling (<b>C</b>) and healing of girdling wound after approximately one month (<b>D</b>).</p> Full article ">Figure 2
<p>Cane girdling impact on kiwifruits’ (<b>a</b>) photosynthesis, (<b>b</b>) intercellular CO<sub>2</sub>, (<b>c</b>) stomatal conductance, (<b>d</b>) ratio of photosynthesis to stomatal conductance, (<b>e</b>) transpiration rate and (<b>f</b>) SPAD index during August, September, and at harvest (October). Abbreviations: GA, kiwifruit cane girdling conducted in August; GS, kiwifruit cane girdling conducted in August; GAS, kiwifruit cane girdling conducted both in August and September. Different letters above columns, separately in September and at harvest, indicate statistically significant differences based on Tukey’s HSD test at α = 0.05. Bars on the columns indicate the standard deviation.</p> Full article ">Figure 3
<p>Cane girdling impact on kiwifruits’ (<b>a</b>) fruit dry matter percentage (%), (<b>b</b>) dry matter per fruit (g), (<b>c</b>) fruit weight (g), (<b>d</b>) fruit length (mm), (<b>e</b>) fruit narrow diameter (mm), (<b>f</b>) fruit wide diameter (mm), (<b>g</b>) ratio of length to narrow diameter and (<b>h</b>) ratio of length to wide diameter during August, September, at harvest, and post-storage. Abbreviations: GA, kiwifruit cane girdling conducted in August; GS, kiwifruit cane girdling conducted in August; GAS, kiwifruit cane girdling conducted both in August and September. Different letters above columns, separately in September, at harvest, and post-storage, indicate statistically significant differences based on Tukey’s HSD test at α = 0.05. Bars on the columns indicate the standard deviation.</p> Full article ">Figure 4
<p>Major nutraceutical and health-promoting compounds per fruit under the various girdling treatments. Abbreviations: TS, total sugars (g); TPh, total phenols (mg); FRAP (μmol equiv. Trolox); DPPH (μmol equiv. Trolox); ASA, ascorbic acid (mg); GA, August girdling; GS, September girdling; GAS, double girdling in August and again in September. The asterisks denote significant differences from the control treatment based on Dunnett’s test.</p> Full article ">
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