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Appl. Sci., Volume 11, Issue 12 (June-2 2021) – 446 articles

Cover Story (view full-size image): The chemical systems that allow for quantitative and irreversible transformations are of considerable interest in numerous fields of science and technology. Contrarily, theoretical methods of quantum chemistry are rarely utilized by experimental chemists to plan and track back their work since it is a complex time-consuming endeavor. This contribution is devoted to the study of the tandem Mannich–electrophilic amination reaction, which involves ‘spring-loaded’ substrates, i.e., pyrido-isoxazolones, and iminium salts derived from secondary amines and formaldehyde. The investigated processes lead to permanently ionized and UV-fluorescent triazolinium salts. The paper aims to explore theoretical mapping of the studied chemical reactivity and identification of factors that limit this chemical transformation. View this paper
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20 pages, 7690 KiB  
Article
A Machine Learning Method Based on 3D Local Surface Representation for Recognizing the Inscriptions on Ancient Stele
by Sheriff Murtala, Ye-Chan Choi and Kang-Sun Choi
Appl. Sci. 2021, 11(12), 5758; https://doi.org/10.3390/app11125758 - 21 Jun 2021
Viewed by 2465
Abstract
It is challenging to extract reliefs from ancient steles due to their rough surfaces, which contain relief-like noise such as dents and scratches. In this paper, we propose a method to segment relief region from 3D scanned ancient stele by exploiting local surface [...] Read more.
It is challenging to extract reliefs from ancient steles due to their rough surfaces, which contain relief-like noise such as dents and scratches. In this paper, we propose a method to segment relief region from 3D scanned ancient stele by exploiting local surface characteristics. For each surface point, four points that are apart from the reference point along the direction of the principal curvatures of the point are identified. The spin images of the reference point and the four relative points are concatenated to provide additional local surface information of the reference point. A random forest model is trained with the local surface features and, thereafter, used to classify 3D surface point as relief or non-relief. To effectively distinguish relief from the degraded surface region containing relief-like noise, the model is trained using three-class labels consisting of relief, background, and degraded surface region. The initial three-class result obtained from the model is refined using the k-nearest neighbors algorithm, and, finally, the degraded region is re-labeled to background region. Experimental results show that the proposed method performed better than the state-of-the-art, SVM-based method with a margin of 0.68%, 3.53%, 2.25%, and 2.36%, in accuracy, precision, F1 score, and SIRI, respectively. When compared with the height- and curvature-based methods, the proposed method outperforms these existing methods with accuracy, precision, F1 score, and SIRI gains of over 4%, 20%, 11%, and 12%, respectively. Full article
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Figure 1

Figure 1
<p>SI representation for a reference oriented point (<math display="inline"><semantics> <msub> <mi mathvariant="bold">v</mi> <mi>i</mi> </msub> </semantics></math>, <math display="inline"><semantics> <mi mathvariant="bold">n</mi> </semantics></math>): (<b>a</b>) 3D point cloud and an imaginary plane <span class="html-italic">P</span> containing <math display="inline"><semantics> <msub> <mi mathvariant="bold">v</mi> <mi>i</mi> </msub> </semantics></math> and having the normal, <math display="inline"><semantics> <mi mathvariant="bold">n</mi> </semantics></math>; (<b>b</b>) the 3D space around <math display="inline"><semantics> <msub> <mi mathvariant="bold">v</mi> <mi>i</mi> </msub> </semantics></math> is partitioned into non-overlapping subspaces; and (<b>c</b>) the 2D histogram of the spin image with axes <math display="inline"><semantics> <mi>ρ</mi> </semantics></math> and <math display="inline"><semantics> <mi>γ</mi> </semantics></math>.</p> Full article ">Figure 2
<p>The proposed relief extraction method.</p> Full article ">Figure 3
<p>Offline SI generation and storage.</p> Full article ">Figure 4
<p>Relative vertices localization. For <math display="inline"><semantics> <msub> <mi mathvariant="bold">v</mi> <mi>i</mi> </msub> </semantics></math>, a 3D point located at a distance of <math display="inline"><semantics> <msub> <mi>d</mi> <mrow> <mi>C</mi> <mi>S</mi> <mi>I</mi> </mrow> </msub> </semantics></math> in <math display="inline"><semantics> <msub> <mi mathvariant="bold">t</mi> <mrow> <mi>m</mi> <mi>a</mi> <mi>x</mi> </mrow> </msub> </semantics></math> direction is identified. The 3D point is projected on the mesh and the closest vertex is obtained as the relative vertex <math display="inline"><semantics> <msubsup> <mi mathvariant="bold">v</mi> <mi>i</mi> <mn>1</mn> </msubsup> </semantics></math>. Similarly, <math display="inline"><semantics> <msubsup> <mi mathvariant="bold">v</mi> <mi>i</mi> <mn>2</mn> </msubsup> </semantics></math> is identified using the opposite direction of <math display="inline"><semantics> <msub> <mi mathvariant="bold">t</mi> <mrow> <mi>m</mi> <mi>a</mi> <mi>x</mi> </mrow> </msub> </semantics></math>.</p> Full article ">Figure 5
<p>Musul-ojakbi stele: (<b>a</b>) 2D photograph; and (<b>b</b>) 3D scanned data.</p> Full article ">Figure 6
<p>The performance of SI-based RF models for different SI parameter combinations (<math display="inline"><semantics> <mrow> <mo>Δ</mo> <mi>ρ</mi> </mrow> </semantics></math> and <math display="inline"><semantics> <mrow> <mo>Δ</mo> <mi>γ</mi> </mrow> </semantics></math>). Both <math display="inline"><semantics> <msub> <mi>N</mi> <mi>ρ</mi> </msub> </semantics></math> and <math display="inline"><semantics> <msub> <mi>N</mi> <mi>γ</mi> </msub> </semantics></math> were set to 10. Each RF model was trained with 500 trees and maximum depth of 32. The best SI parameter combination is (<math display="inline"><semantics> <mrow> <mo>Δ</mo> <mi>ρ</mi> </mrow> </semantics></math>, <math display="inline"><semantics> <mrow> <mo>Δ</mo> <mi>γ</mi> </mrow> </semantics></math>) = (0.60, 0.50).</p> Full article ">Figure 7
<p>Effects of mesh smoothing on reliability of estimated curvature: (<b>a</b>) mesh partition; (<b>b</b>) no filtering; (<b>c</b>) <math display="inline"><semantics> <mi>σ</mi> </semantics></math> = 0.3; (<b>d</b>) <math display="inline"><semantics> <mi>σ</mi> </semantics></math> = 0.9; (<b>e</b>) <math display="inline"><semantics> <mi>σ</mi> </semantics></math> = 1.6; (<b>f</b>) <math display="inline"><semantics> <mi>σ</mi> </semantics></math> = 2.0; and (<b>g</b>) <math display="inline"><semantics> <mi>σ</mi> </semantics></math> = 4.0.</p> Full article ">Figure 8
<p>Performance of RF models (in terms of F1 score) under different <math display="inline"><semantics> <mi>σ</mi> </semantics></math> values.</p> Full article ">Figure 9
<p>Performance of RF models (in terms of F1 score) for various <math display="inline"><semantics> <msub> <mi>d</mi> <mrow> <mi>C</mi> <mi>S</mi> <mi>I</mi> </mrow> </msub> </semantics></math> values.</p> Full article ">Figure 10
<p>Feature importance of RF (CSI) models <math display="inline"><semantics> <mrow> <msub> <mi>d</mi> <mrow> <mi>C</mi> <mi>S</mi> <mi>I</mi> </mrow> </msub> <mo>=</mo> </mrow> </semantics></math> 1 and 3.</p> Full article ">Figure 11
<p>Subjective comparison of the classification results before re-labeling. The second and third columns were obtained using the RF models trained using SI and CSI, respectively. The fourth column was obtained after applying <span class="html-italic">k</span>-NN to the third column. The <span class="html-italic">k</span>-NN fills the holes and gets rid of isolated points.</p> Full article ">Figure 12
<p>Comparison of feature importance of RF(CSI) and RF(SI).</p> Full article ">Figure 13
<p>The comparison of the proposed method and existing methods: (<b>a</b>) mesh partitions; (<b>b</b>) ground truth; (<b>c</b>) the height-based method [<a href="#B8-applsci-11-05758" class="html-bibr">8</a>]; (<b>d</b>) the curvature-based method [<a href="#B7-applsci-11-05758" class="html-bibr">7</a>]; (<b>e</b>) the modified curvature-based method [<a href="#B18-applsci-11-05758" class="html-bibr">18</a>]; and (<b>f</b>) the SVM-based method [<a href="#B24-applsci-11-05758" class="html-bibr">24</a>]. (<b>g</b>) The proposed method.</p> Full article ">Figure 14
<p>The comparison of the existing relief extraction methods and the proposed method: (<b>a</b>) stone rubbing; (<b>b</b>) the height-based method [<a href="#B8-applsci-11-05758" class="html-bibr">8</a>]; (<b>c</b>) the curvature-based method [<a href="#B7-applsci-11-05758" class="html-bibr">7</a>]; (<b>d</b>) the modified curvature-based method [<a href="#B18-applsci-11-05758" class="html-bibr">18</a>]; (<b>e</b>) the SVM-based method [<a href="#B24-applsci-11-05758" class="html-bibr">24</a>]; and (<b>f</b>) the proposed method.</p> Full article ">Figure 15
<p>Performance evaluation of the relief extraction methods in terms of precision, accuracy, recall, F1 score, and SIRI.</p> Full article ">
16 pages, 692 KiB  
Article
3D Volumetric Tensor Velocity Imaging with Low Computational Complexity Using a Row-Column Addressed Array
by Kseniya Chetverikova, Jørgen Arendt Jensen, Marie Sand Traberg and Matthias Bo Stuart
Appl. Sci. 2021, 11(12), 5757; https://doi.org/10.3390/app11125757 - 21 Jun 2021
Viewed by 2386
Abstract
A method for volumetric Tensor Velocity Imaging employing row-column (RC) addressed array with low computational complexity is investigated in simulations. An interleaved and non-interleaved sliding aperture sequence with 11 rows and 11 columns emissions by a 62 + 62 RC addressed array was [...] Read more.
A method for volumetric Tensor Velocity Imaging employing row-column (RC) addressed array with low computational complexity is investigated in simulations. An interleaved and non-interleaved sliding aperture sequence with 11 rows and 11 columns emissions by a 62 + 62 RC addressed array was used. The 3D velocities were estimated by a transverse oscillation (TO) cross-correlation estimator. Parabolic profiles at six different orientations corresponding to combinations of 0, 45 degrees azimuth angles and 90, 75, 60 beam-to-flow angles were investigated with 5 kHz pulse repetition frequencies. The Field II simulations were performed at a depth of 30 mm with peak velocity of 0.3 m/s. Across all vessel orientations, the relative mean bias varied from 2.3% to −14.26%, and the relative standard deviation varied from 0.43% to 5.5%. The best and worst performance was found at beam to flow angles of 90 degrees with 0 degrees rotation angle and 60 degrees beam-to-flow angle with 45 degrees rotation angle respectively. Due to the low channel count of the RC array and the low computational complexity, real-time implementation is feasible on conventional ultrasound systems. Full article
(This article belongs to the Topic Medical Image Analysis)
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<p>Example of a tensor velocity image. Arrows show the 3D velocity vector in each sample in the volume. The volume is sampled in 11 planes, each plane providing a cross-sectional view of a vessel with laminar flow.</p> Full article ">Figure 2
<p>Two 1D arrays (<math display="inline"><semantics> <mrow> <mn>1</mn> <mo>×</mo> <mi>N</mi> </mrow> </semantics></math> and <math display="inline"><semantics> <mrow> <mi>N</mi> <mo>×</mo> <mn>1</mn> </mrow> </semantics></math>) are mounted orthogonally on top of each other to form 2D RC-addressed <math display="inline"><semantics> <mrow> <mi>N</mi> <mo>+</mo> <mi>N</mi> </mrow> </semantics></math> array.</p> Full article ">Figure 3
<p>Sequence scheme. <math display="inline"><semantics> <msub> <mi>R</mi> <mi>i</mi> </msub> </semantics></math> are rows and <math display="inline"><semantics> <msub> <mi>C</mi> <mi>i</mi> </msub> </semantics></math> are columns transmissions.</p> Full article ">Figure 4
<p>Estimated center profiles from simulated data for <math display="inline"><semantics> <mrow> <mi>α</mi> <mo>=</mo> <msup> <mrow> <mo>(</mo> <mn>60</mn> <mo>,</mo> <mn>75</mn> <mo>,</mo> <mn>90</mn> <mo>)</mo> </mrow> <mo>∘</mo> </msup> </mrow> </semantics></math>, <math display="inline"><semantics> <mrow> <mi>β</mi> <mo>=</mo> <msup> <mn>0</mn> <mo>∘</mo> </msup> </mrow> </semantics></math>. Standard settings from <a href="#applsci-11-05757-t001" class="html-table">Table 1</a> were used. The red line is theoretical profile, the blue curve is estimated mean profile, the dashed black curves are the relative standard deviation.</p> Full article ">Figure 5
<p>RSD and RB for simulations with (90, 75, 60) degrees beam-to-flow anlges and 0 degrees rotation angle. The dashed lines show the relative standard deviation, the solid lines show the relative bias. The red color is <math display="inline"><semantics> <msub> <mi>v</mi> <mi>x</mi> </msub> </semantics></math>, the black is <math display="inline"><semantics> <msub> <mi>v</mi> <mi>y</mi> </msub> </semantics></math> and the blue is <math display="inline"><semantics> <msub> <mi>v</mi> <mi>z</mi> </msub> </semantics></math> components of the flow.</p> Full article ">Figure 6
<p>Estimated center profiles from simulated data for <math display="inline"><semantics> <mrow> <mi>α</mi> <mo>=</mo> <msup> <mrow> <mo>(</mo> <mn>60</mn> <mo>,</mo> <mn>75</mn> <mo>,</mo> <mn>90</mn> <mo>)</mo> </mrow> <mo>∘</mo> </msup> </mrow> </semantics></math>, <math display="inline"><semantics> <mrow> <mi>β</mi> <mo>=</mo> <msup> <mn>45</mn> <mo>∘</mo> </msup> </mrow> </semantics></math>. Standard settings from <a href="#applsci-11-05757-t001" class="html-table">Table 1</a> were used. The red line is theoretical profile, the blue curve is estimated mean profile, the dashed black curves are the relative standard deviation.</p> Full article ">Figure 7
<p>RSD and RB for simulations with (90, 75, 60) degrees beam-to-flow anlges and 45 degrees rotation angle. The dashed lines show the relative standard deviation, the solid lines show the relative bias. The red color is <math display="inline"><semantics> <msub> <mi>v</mi> <mi>x</mi> </msub> </semantics></math>, the black is <math display="inline"><semantics> <msub> <mi>v</mi> <mi>y</mi> </msub> </semantics></math> and the blue is <math display="inline"><semantics> <msub> <mi>v</mi> <mi>z</mi> </msub> </semantics></math> components of the flow.</p> Full article ">Figure 8
<p>RSD and RB for 90 degrees beam-to-flow angle and 0 degrees rotation angle, all cross planes along the vessel. The dashed lines show the relative standard deviation, the solid lines show the relative bias. The red color is <math display="inline"><semantics> <msub> <mi>v</mi> <mi>x</mi> </msub> </semantics></math>, the black is <math display="inline"><semantics> <msub> <mi>v</mi> <mi>y</mi> </msub> </semantics></math> and the blue is <math display="inline"><semantics> <msub> <mi>v</mi> <mi>z</mi> </msub> </semantics></math> components of the flow.</p> Full article ">Figure 9
<p>RSD and RB for 60 degrees beam-to-flow angle and 45 degrees rotation angle, all cross planes along the vessel.The dashed lines show the relative standard deviation, the solid lines show the relative bias. The red color is <math display="inline"><semantics> <msub> <mi>v</mi> <mi>x</mi> </msub> </semantics></math>, the black is <math display="inline"><semantics> <msub> <mi>v</mi> <mi>y</mi> </msub> </semantics></math> and the blue is <math display="inline"><semantics> <msub> <mi>v</mi> <mi>z</mi> </msub> </semantics></math> components of the flow.</p> Full article ">Figure 10
<p>Cross planes for three representative methods. On the left side is <math display="inline"><semantics> <msub> <mi>v</mi> <mi>x</mi> </msub> </semantics></math>, on the middle is <math display="inline"><semantics> <msub> <mi>v</mi> <mi>y</mi> </msub> </semantics></math>, on the right is <math display="inline"><semantics> <msub> <mi>v</mi> <mi>z</mi> </msub> </semantics></math> components of the flow. For all situations the beam-to-flow angle was 90 degrees and azimuth rotation angle is 0 degrees. The top row shows a cross planes from the interleaved sequence. The middle row shows cross planes from the non-interleaved sequence with <math display="inline"><semantics> <msub> <mi>f</mi> <mrow> <mi>p</mi> <mi>r</mi> <mi>f</mi> </mrow> </msub> </semantics></math> = 5 kHz, the bottom row shows cross planes from the non-interleaved sequence with <math display="inline"><semantics> <msub> <mi>f</mi> <mrow> <mi>p</mi> <mi>r</mi> <mi>f</mi> </mrow> </msub> </semantics></math> = 10 kHz.</p> Full article ">
21 pages, 19532 KiB  
Article
Skeleton Tracking Accuracy and Precision Evaluation of Kinect V1, Kinect V2, and the Azure Kinect
by Michal Tölgyessy, Martin Dekan and Ľuboš Chovanec
Appl. Sci. 2021, 11(12), 5756; https://doi.org/10.3390/app11125756 - 21 Jun 2021
Cited by 61 | Viewed by 10337
Abstract
The Azure Kinect, the successor of Kinect v1 and Kinect v2, is a depth sensor. In this paper we evaluate the skeleton tracking abilities of the new sensor, namely accuracy and precision (repeatability). Firstly, we state the technical features of all three sensors, [...] Read more.
The Azure Kinect, the successor of Kinect v1 and Kinect v2, is a depth sensor. In this paper we evaluate the skeleton tracking abilities of the new sensor, namely accuracy and precision (repeatability). Firstly, we state the technical features of all three sensors, since we want to put the new Azure Kinect in the context of its previous versions. Then, we present the experimental results of general accuracy and precision obtained by measuring a plate mounted to a robotic manipulator end effector which was moved along the depth axis of each sensor and compare them. In the second experiment, we mounted a human-sized figurine to the end effector and placed it in the same positions as the test plate. Positions were located 400 mm from each other. In each position, we measured relative accuracy and precision (repeatability) of the detected figurine body joints. We compared the results and concluded that the Azure Kinect surpasses its discontinued predecessors, both in accuracy and precision. It is a suitable sensor for human–robot interaction, body-motion analysis, and other gesture-based applications. Our analysis serves as a pilot study for future HMI (human–machine interaction) designs and applications using the new Kinect Azure and puts it in the context of its successful predecessors. Full article
(This article belongs to the Special Issue Social Robotics and Human-Robot Interaction (HRI))
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<p>From left to right—Kinect v1, Kinect v2, Azure Kinect.</p> Full article ">Figure 2
<p>Schematic of the Azure Kinect.</p> Full article ">Figure 3
<p>Scheme for general accuracy and precision measurements using robotic manipulator.</p> Full article ">Figure 4
<p>General precision measurements of all three Kinect versions.</p> Full article ">Figure 5
<p>General accuracy measurements of all three Kinect versions.</p> Full article ">Figure 6
<p>(<b>A</b>) Plastic figurine moved along the Z axis of the examined sensor. (<b>B</b>) Picture of the actual laboratory experiment. (<b>C</b>) Example of detected and undetected body joints.</p> Full article ">Figure 6 Cont.
<p>(<b>A</b>) Plastic figurine moved along the Z axis of the examined sensor. (<b>B</b>) Picture of the actual laboratory experiment. (<b>C</b>) Example of detected and undetected body joints.</p> Full article ">Figure 7
<p>List of skeleton body joints detected by corresponding Kinect sensor (the presented colors are used in all figures throughout the paper).</p> Full article ">Figure 8
<p>Body joint precision measurements of Kinect v1.</p> Full article ">Figure 9
<p>Body joint precision measurements of Kinect v1 with skeleton smoothing turned off.</p> Full article ">Figure 10
<p>Body joint precision measurements of Kinect v2.</p> Full article ">Figure 11
<p>Body joint precision measurements of Azure Kinect in the NFOV mode.</p> Full article ">Figure 12
<p>Body joint precision measurements of Azure Kinect in the WFOV mode.</p> Full article ">Figure 13
<p>Body joint relative accuracy measurements of Kinect v1.</p> Full article ">Figure 14
<p>Body joint relative accuracy measurements of Kinect v1 with skeleton smoothing turned off.</p> Full article ">Figure 15
<p>Body joint relative accuracy measurements of Kinect v2.</p> Full article ">Figure 16
<p>Body joint relative measurements of Azure Kinect in the NFOV mode.</p> Full article ">Figure 17
<p>Body joint relative measurements of Azure Kinect in the WFOV mode.</p> Full article ">Figure 18
<p>Body joint average position distance variation of all sensors (only body joints common for all sensors were are included).</p> Full article ">Figure 19
<p>Body joint noise of Kinect v1.</p> Full article ">Figure 20
<p>Body joint noise of Kinect v1 with skeleton smoothing turned off.</p> Full article ">Figure 21
<p>Body joint noise of Kinect v2.</p> Full article ">Figure 22
<p>Body joint noise of Azure Kinect in the NFOV mode.</p> Full article ">Figure 23
<p>Body joint noise of Azure Kinect in the WFOV mode.</p> Full article ">
13 pages, 879 KiB  
Article
A Pilot Proteomic Study of Normal Human Tears: Leptin as a Potential Biomarker of Metabolic Disorders
by Mungunshur Byambajav, Cristina Arroyo-del Arroyo, Amalia Enríquez-de-Salamanca, Itziar Fernández, Eilidh Martin and Suzanne Hagan
Appl. Sci. 2021, 11(12), 5755; https://doi.org/10.3390/app11125755 - 21 Jun 2021
Cited by 3 | Viewed by 2935
Abstract
The concentrations of insulin, leptin, active ghrelin, C-peptide and gastric inhibitory polypeptide (GIP) and their inter-day variations were examined in normal human tears. In addition, correlations between the concentrations of these metabolic proteins and ocular surface parameters were determined. Subjects with healthy ocular [...] Read more.
The concentrations of insulin, leptin, active ghrelin, C-peptide and gastric inhibitory polypeptide (GIP) and their inter-day variations were examined in normal human tears. In addition, correlations between the concentrations of these metabolic proteins and ocular surface parameters were determined. Subjects with healthy ocular surfaces attended three visits, with 7-day intervals. Tear evaporation rate (TER) and non-invasive tear break-up time (NITBUT) were assessed, and a total of 2 µL tears were collected from all subjects. Tear fluid concentrations of insulin, leptin, active ghrelin, C-peptide and GIP were measured by multiplex bead analysis. Insulin was the most highly expressed metabolic protein, followed by leptin, C-peptide, active ghrelin and GIP. Of these, only active ghrelin had a significant inter-day variation (p < 0.05). There was no inter-day variation in the mean concentrations of the other metabolic proteins. Leptin had a strong intra-class reproducibility. No correlation was detected between tear metabolic protein concentrations and ocular surface parameters. This pilot study shows, for the first time, that active ghrelin and GIP are detectable in healthy tears. The strong intra-class reproducibility for leptin shows that it could be used as a potential tear fluid biomarker and, possibly, in determining the effects of metabolic disorders on the ocular surface. Full article
(This article belongs to the Special Issue Potential Biomarkers in Tears)
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Figure 1
<p>The concentrations (in pg/mL) of (<b>A</b>) leptin, (<b>B</b>) insulin, (<b>C</b>) active ghrelin, (<b>D</b>) C-peptide and (<b>E</b>) GIP were expressed as mean ± S.D. for each visit, V1 and V2. The red horizontal line shows the MinDC.</p> Full article ">Figure 1 Cont.
<p>The concentrations (in pg/mL) of (<b>A</b>) leptin, (<b>B</b>) insulin, (<b>C</b>) active ghrelin, (<b>D</b>) C-peptide and (<b>E</b>) GIP were expressed as mean ± S.D. for each visit, V1 and V2. The red horizontal line shows the MinDC.</p> Full article ">Figure 2
<p>The Bland-Altman plots for (<b>A</b>) active ghrelin and (<b>B</b>) C-peptide.</p> Full article ">
18 pages, 8092 KiB  
Article
Human–Robot Collaborative Assembly Based on Eye-Hand and a Finite State Machine in a Virtual Environment
by Xue Zhao, Ye He, Xiaoan Chen and Zhi Liu
Appl. Sci. 2021, 11(12), 5754; https://doi.org/10.3390/app11125754 - 21 Jun 2021
Cited by 14 | Viewed by 4331
Abstract
With the development of the global economy, the demand for manufacturing is increasing. Accordingly, human–robot collaborative assembly has become a research hotspot. This paper aims to solve the efficiency problems inherent in traditional human-machine collaboration. Based on eye–hand and finite state machines, a [...] Read more.
With the development of the global economy, the demand for manufacturing is increasing. Accordingly, human–robot collaborative assembly has become a research hotspot. This paper aims to solve the efficiency problems inherent in traditional human-machine collaboration. Based on eye–hand and finite state machines, a collaborative assembly method is proposed. The method determines the human’s intention by collecting posture and eye data, which can control a robot to grasp an object, move it, and perform co-assembly. The robot’s automatic path planning is based on a probabilistic roadmap planner. Virtual reality tests show that the proposed method is more efficient than traditional methods. Full article
(This article belongs to the Topic New Frontiers in Industry 4.0)
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Figure 1
<p>The human–robot interaction model.</p> Full article ">Figure 2
<p>Users control the robot stacking according to the image requirements in the iPad through the eye–hand combination.</p> Full article ">Figure 3
<p>Nine gestures that are easy to use and distinguish.</p> Full article ">Figure 4
<p>Bending angles of the finger relative to the palm.</p> Full article ">Figure 5
<p>(<b>A</b>) Finger bending angles in gestures G1–G9. (<b>B</b>) The Recognition results for each gesture.</p> Full article ">Figure 6
<p>The eye and finger points used to select a target object. (<b>A</b>) Eye–hand trigger selection in the dotted line circles. (<b>B</b>) The algorithm flow chart of the judging trigger.</p> Full article ">Figure 6 Cont.
<p>The eye and finger points used to select a target object. (<b>A</b>) Eye–hand trigger selection in the dotted line circles. (<b>B</b>) The algorithm flow chart of the judging trigger.</p> Full article ">Figure 7
<p>The FSM is based on Simulink. The date in the FSM is transmission to Unity by UDP connection. The user changes the running state of the robot by eye–hand combinations.</p> Full article ">Figure 8
<p>The robot selecting objects from a white square and placing them in a red square.</p> Full article ">Figure 9
<p>A flowchart of the human–computer interaction program.</p> Full article ">Figure 10
<p>Interactive process: After the users indicate the block and position, there will be a small white circle prompt. The small red dot represents the intersection of hand and screen. The small yellow dot represents the eye annotation point.</p> Full article ">Figure 11
<p>The teaching device.</p> Full article ">Figure 12
<p>Positions of eyes and hand during the interaction. (<b>A</b>) The position of eye’s point and hand’s point in interaction. (<b>B</b>) The relationship between position and time of point.</p> Full article ">Figure 13
<p>Robot trajectory of our model combining automatic and mapping parts.</p> Full article ">Figure 14
<p>A comparison between conventional methods and the proposed method. (<b>A</b>) Button states 1–6 = up, down, left, right, forward, and back. States 7–12 = +Roll, −Roll, +Pitch, −Pitch, +Yaw, and −Yaw. States 13–14 = Grab, Release. (<b>B</b>) Eye–hand states 1–4 = Recognize, Indication, Capture, and Mapping.</p> Full article ">Figure 15
<p>A comparison of the assembly states and times of Groups A and B.</p> Full article ">Figure 16
<p>Comparisons of the percentages of time occupied by each assembly state.</p> Full article ">
18 pages, 1951 KiB  
Article
Obtaining Forest Biomass for Energy Purposes as an Enterprise Development Factor in Rural Areas
by Kamil Roman, Michał Roman, Monika Wojcieszak-Zbierska and Monika Roman
Appl. Sci. 2021, 11(12), 5753; https://doi.org/10.3390/app11125753 - 21 Jun 2021
Cited by 4 | Viewed by 2453
Abstract
This article presents how selected factors related to forest biomass affect enterprise development in rural areas. The study used a multivariate analysis of variance (ANOVA), as well as the AHP operational research method. The following factors were selected for analysis: conifer timber harvesting, [...] Read more.
This article presents how selected factors related to forest biomass affect enterprise development in rural areas. The study used a multivariate analysis of variance (ANOVA), as well as the AHP operational research method. The following factors were selected for analysis: conifer timber harvesting, sales of renewable fuel in the form of briquettes to selected customers, and the number of the given company’s regular customers. Their selection was determined by the fact that using plant material for energy purposes has become significantly more popular in recent years. This particularly includes forest biomass, which is increasingly used as an energy commodity in the Polish heating industry. Forest biomass is a biodegradable raw material generated in the form of waste during wood production and processing, as well as during sanitation cutting. The study was conducted using a diagnostic survey method with a survey questionnaire in the first quarter of 2020. It included 614 owners of small and medium-sized enterprises operating in various rural areas across all of Poland’s voivodeships. The study was conducted using the CATI method. Analyses defining the dependence of specific factors on the examined parameters and supporting the priority nature of the given actions may show the development of particular pro-ecological actions in a given area. In one case, the critical level of significance determining the assignment of the analyzed factor to a specific homogeneous group was below 0.05. This means that there was a correlation between the sales of renewable fuel in the form of briquettes to selected customers and the number of enterprises in the voivodeship. Therefore, due to the sales of renewable fuel in the form of briquettes to selected customers, the greatest development prospects for wood industry companies existed in the Małopolskie, Mazowieckie, Śląskie and Wielkopolskie Voivodeships. Full article
(This article belongs to the Special Issue Advances in Biomass Research and Applications)
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<p>Conifer timber harvesting in Poland in the 2002–2019 period. Source: [<a href="#B14-applsci-11-05753" class="html-bibr">14</a>].</p> Full article ">Figure 2
<p>The two-stage company environment.</p> Full article ">Figure 3
<p>Forest biomass sources. Source: [<a href="#B57-applsci-11-05753" class="html-bibr">57</a>].</p> Full article ">Figure 4
<p>The relationship between the number of enterprises and conifer timber harvesting.</p> Full article ">Figure 5
<p>The characteristics of the relationship between the number of enterprises and renewable fuel briquette sales to selected customers.</p> Full article ">Figure 6
<p>Characteristics of the relationship between the number of enterprises and the number of regular customers of an enterprise.</p> Full article ">Figure 7
<p>Weight values.</p> Full article ">
17 pages, 5989 KiB  
Article
Development of Scott Transformer Model in Electromagnetic Transients Programs for Real-Time Simulations
by Choongman Lee, Gyu-Jung Cho and Joorak Kim
Appl. Sci. 2021, 11(12), 5752; https://doi.org/10.3390/app11125752 - 21 Jun 2021
Cited by 1 | Viewed by 4740
Abstract
This paper presents a Scott transformer model to be applied in electromagnetic transients (EMT) programs, particularly in the absence of a detailed Scott transformer model for performing real-time simulations (RTS). Regarding a Scott transformer, a common topology for converting a three-phase network into [...] Read more.
This paper presents a Scott transformer model to be applied in electromagnetic transients (EMT) programs, particularly in the absence of a detailed Scott transformer model for performing real-time simulations (RTS). Regarding a Scott transformer, a common topology for converting a three-phase network into two single-phase networks, the transformer model in EMT programs is essential to simulate large-scale electric railway systems. A code-based model has been developed to simulate the transformer in RTS directly and contain the transformer’s actual impedance characteristics. By establishing a mathematical foundation with the current injection method, we presented a matrix representation in conjunction with a network solution of EMT programs. The proposed model can handle more practical parameters of Scott transformers with a relatively low computational load. Thus, it supports the flexible computation of real-time simulators with a finite number of processor units. The accuracy of the model is verified by simulating it and comparing the simulation results with an industrial transformer’s certified performance. Furthermore, a case study involving a comparison of the results with the field measurement data of an actual Korean railway system demonstrated the efficacy of the model. Full article
(This article belongs to the Section Electrical, Electronics and Communications Engineering)
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<p>The basic structure of Scott transformer.</p> Full article ">Figure 2
<p>Scott connection using a single-phase transformer and a single-phase three-winding transformer.</p> Full article ">Figure 3
<p>Scott transformer model in the Library of RSCAD.</p> Full article ">Figure 4
<p>Circuit configuration for impedance voltage test of the Library Scott transformer model.</p> Full article ">Figure 5
<p>Impedance voltage test result for the Library Scott transformer model: (<b>a</b>) unbalanced three-phase current waveform; (<b>b</b>) unbalanced M- and T-phase current waveforms and vector representation.</p> Full article ">Figure 6
<p>Configuration of an equivalent circuit for a single-phase transformer.</p> Full article ">Figure 7
<p>The proposed Scott transformer model linked to C source code in RSCAD.</p> Full article ">Figure 8
<p>Scott connection using a single-phase transformer and a single-phase three-winding transformer in the Substep library.</p> Full article ">Figure 9
<p>Comparison between computational loads of (<b>a</b>) Scott connection using the Substep library models (processor assignment for Scott connection using a single-phase transformer and 3-winding transformer from the Substep library) and (<b>b</b>) the proposed Scott transformer (processor assignment for Scott connection based on the proposed model).</p> Full article ">Figure 10
<p>An equivalent circuit diagram for impedance voltage test.</p> Full article ">Figure 11
<p>Result of impedance voltage test for the proposed Scott transformer: (<b>a</b>) three-phase current waveforms; (<b>b</b>) M- and T-phase current waveforms and vector representation.</p> Full article ">Figure 11 Cont.
<p>Result of impedance voltage test for the proposed Scott transformer: (<b>a</b>) three-phase current waveforms; (<b>b</b>) M- and T-phase current waveforms and vector representation.</p> Full article ">Figure 12
<p>Circuit diagram for short-circuit test of the Scott transformer.</p> Full article ">Figure 13
<p>M-phase short-circuit test results of Scott transformer (comparison between short-circuit test results obtained by RTDS and those in the certified test report by KERI): (<b>a</b>) waveform of short-circuit test result of the proposed Scott transformer, obtained by RTDS simulation (M-phase); (<b>b</b>) waveform in the certified test report (M-phase).</p> Full article ">Figure 14
<p>T-phase short-circuit test result of Scott transformer (comparison between short-circuit test results obtained by RTDS and those in the certified test report by KERI): (<b>a</b>) waveform of the short-circuit test result of the proposed Scott transformer (T-phase); (<b>b</b>) waveform in the certified test report (T-phase).</p> Full article ">Figure 15
<p>Part of the electric railway system in Jeolla province in South Korea.</p> Full article ">Figure 16
<p>Comparison of accuracy between the simulation results of each model and the actual measurement data.</p> Full article ">Figure 17
<p>Processor assignment of the RTDS for the case study: (<b>a</b>) processor assignment when the Scott Connection is configured using the Substep model; (<b>b</b>) processor assignment using the proposed model.</p> Full article ">Figure 17 Cont.
<p>Processor assignment of the RTDS for the case study: (<b>a</b>) processor assignment when the Scott Connection is configured using the Substep model; (<b>b</b>) processor assignment using the proposed model.</p> Full article ">
19 pages, 13211 KiB  
Article
Depth-Integrated Two-Phase Modeling of Two Real Cases: A Comparison between r.avaflow and GeoFlow-SPH Codes
by Seyed Ali Mousavi Tayebi, Saeid Moussavi Tayyebi and Manuel Pastor
Appl. Sci. 2021, 11(12), 5751; https://doi.org/10.3390/app11125751 - 21 Jun 2021
Cited by 18 | Viewed by 4071
Abstract
Due to the growing populations in areas at high risk of natural disasters, hazard and risk assessments of landslides have attracted significant attention from researchers worldwide. In order to assess potential risks and design possible countermeasures, it is necessary to have a better [...] Read more.
Due to the growing populations in areas at high risk of natural disasters, hazard and risk assessments of landslides have attracted significant attention from researchers worldwide. In order to assess potential risks and design possible countermeasures, it is necessary to have a better understanding of this phenomenon and its mechanism. As a result, the prediction of landslide evolution using continuum dynamic modeling implemented in advanced simulation tools is becoming more important. We analyzed a depth-integrated, two-phase model implemented in two different sets of code to stimulate rapid landslides, such as debris flows and rock avalanches. The first set of code, r.avaflow, represents a GIS-based computational framework and employs the NOC-TVD numerical scheme. The second set of code, GeoFlow-SPH, is based on the mesh-free numerical method of smoothed particle hydrodynamics (SPH) with the capability of describing pore pressure’s evolution along the vertical distribution of flowing mass. Two real cases of an Acheron rock avalanche and Sham Tseng San Tsuen debris flow were used with the best fit values of geotechnical parameters obtained in the prior modeling to investigate the capabilities of the sets of code. Comparison of the results evidenced that both sets of code were capable of properly reproducing the run-out distance, deposition thickness, and deposition shape in the benchmark exercises. However, the values of maximum propagation velocities and thickness were considerably different, suggesting that using more than one set of simulation code allows us to predict more accurately the possible scenarios and design more effective countermeasures. Full article
(This article belongs to the Special Issue Advanced Numerical Simulations in Geotechnical Engineering)
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<p>Scheme for obtaining partial heights of both phases.</p> Full article ">Figure 2
<p>SPH interactions for two-phase flow.</p> Full article ">Figure 3
<p>A 1D finite difference mesh at each SPH node representing solid particles.</p> Full article ">Figure 4
<p>(<b>a</b>) A general view of the source area, (<b>b</b>) the area impacted by the avalanche, and (<b>c</b>) its location (Google Maps).</p> Full article ">Figure 5
<p>A comparison between two sets of code: the results on the left side were obtained with Geoglow and on the right side with r.avaflow. They show the flow propagation path, with the numerical results of flow-depth and maximum velocity at different times: (<b>a</b>) 0 s, (<b>b</b>) 20 s, (<b>c</b>) 40 s, (<b>d</b>) 60 s, (<b>e</b>) 100 s, and (<b>f</b>) 230 s.</p> Full article ">Figure 6
<p>Comparison of the numerical results of (<b>a</b>) the maximum deposition thickness and (<b>b</b>) the maximum velocity obtained from the r.avaflow and GeoFlow-SPH programs.</p> Full article ">Figure 7
<p>General view of the landslide location. (Provided by Wilson et al. (2005) [<a href="#B42-applsci-11-05751" class="html-bibr">42</a>]).</p> Full article ">Figure 8
<p>A comparison between two sets of code. The results on the left side were obtained with GeoFlow-SPH, and those on the right side with r.avaflow. They show the flow propagation path, with the numerical results of flow-depth and maximum velocity at different times: (<b>a</b>) 0 s, (<b>b</b>) 20 s, (<b>c</b>) 40 s, and (<b>d</b>) 60 s.</p> Full article ">Figure 9
<p>The distribution of relative pore–water pressure at (<b>a</b>) 0 s, (<b>b</b>) 10 s, (<b>c</b>) 20 s, and (<b>d</b>) 60 s.</p> Full article ">
11 pages, 275 KiB  
Perspective
Agriculture 4.0: Is Sub-Saharan Africa Ready?
by Nugun P. Jellason, Elizabeth J. Z. Robinson and Chukwuma C. Ogbaga
Appl. Sci. 2021, 11(12), 5750; https://doi.org/10.3390/app11125750 - 21 Jun 2021
Cited by 49 | Viewed by 8525
Abstract
A fourth agricultural revolution, termed agriculture 4.0, is gradually gaining ground around the globe. It encompasses the application of smart technologies such as artificial intelligence, biotechnology, the internet of things (IoT), big data, and robotics to improve agriculture and the sustainability of food [...] Read more.
A fourth agricultural revolution, termed agriculture 4.0, is gradually gaining ground around the globe. It encompasses the application of smart technologies such as artificial intelligence, biotechnology, the internet of things (IoT), big data, and robotics to improve agriculture and the sustainability of food production. To date, narratives around agriculture 4.0 associated technologies have generally focused on their application in the context of higher-income countries (HICs). In contrast, in this perspective, we critically assess the place of sub-Saharan Africa (SSA) in this new technology trajectory, a region that has received less attention with respect to the application of such technologies. We examine the continent’s readiness based on a number of dimensions such as scale, finance, technology leapfrogging, institutions and governance, education and skills. We critically reviewed the challenges, opportunities, and prospects of adopting agriculture 4.0 technologies in SSA, particularly with regards to how smallholder farmers in the region can be involved through a robust strategy. We find that whilst potential exist for agriculture 4.0 adoption in SSA, there are gaps in knowledge, skills, finance, and infrastructure to ensure successful adoption. Full article
(This article belongs to the Special Issue Agriculture 4.0 – the Future of Farming Technology)
24 pages, 11245 KiB  
Article
On Characteristics of Ice Ridges and Icebergs for Design of Ship Hulls in Polar Regions Based on Environmental Design Contours
by Bernt J. Leira, Wei Chai and Gowtham Radhakrishnan
Appl. Sci. 2021, 11(12), 5749; https://doi.org/10.3390/app11125749 - 21 Jun 2021
Cited by 8 | Viewed by 2738
Abstract
Ice ridges and icebergs generally pose a major threat to both ships and offshore facilities that operate in Polar regions. In many cases these features will govern the structural design loads associated with the Ultimate Limit State (ULS) and the Accidental Limit State [...] Read more.
Ice ridges and icebergs generally pose a major threat to both ships and offshore facilities that operate in Polar regions. In many cases these features will govern the structural design loads associated with the Ultimate Limit State (ULS) and the Accidental Limit State (ALS). In general, a large number of load cases must be considered in order to ascertain an adequate structural resistance. Alternatively, conservatively high values of the relevant design parameters can be applied, which implies cost penalties. Accordingly, it is natural to consider methods that can serve to reduce the number of relevant load cases. Based on relevant information about the statistical properties of the parameters that characterize ice ridges and icebergs, the most likely combinations of these parameters for design purposes are highly relevant. On this background, the so-called environmental contour method is applied. Probabilistic models of the key parameters that govern the ship and ice interaction process are introduced. Subsequently, the procedure referred to as inverse reliability methods (IFORM) is applied for identification of the environmental contour. Different forms (i.e., dimensions) of environmental contours are generated to reflect the characteristics of the interaction process. Furthermore, the effect of an increasing correlation between the basic parameters is studied. In addition, the increase of the design parameter values for increasing encounter frequencies is illustrated. Full article
(This article belongs to the Special Issue Recent Advances on Safe Maritime Operations under Extreme Conditions)
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<p>ULS, shared design, and ALS. The vertical axis shows energy absorbed by structure divided by energy absorbed by ice feature (energy ratio).</p> Full article ">Figure 2
<p>Energy absorption and examples of force–displacement curves: (<b>a</b>) impact by ice floe and (<b>b</b>) comparison of load–displacement curves and energy absorption for different impact scenarios (blue curves: ice mass is 288 tons; red curves: ice mass is 500 tons; magenta curves: ice mass is 1000 tons; violet curves: ice mass is 1500 tons).</p> Full article ">Figure 2 Cont.
<p>Energy absorption and examples of force–displacement curves: (<b>a</b>) impact by ice floe and (<b>b</b>) comparison of load–displacement curves and energy absorption for different impact scenarios (blue curves: ice mass is 288 tons; red curves: ice mass is 500 tons; magenta curves: ice mass is 1000 tons; violet curves: ice mass is 1500 tons).</p> Full article ">Figure 3
<p>First-year ice ridge with the key parameters: sail width <span class="html-italic">w<sub>s</sub></span>, sail draft <span class="html-italic">h<sub>s</sub></span>, consolidated layer thickness <span class="html-italic">h<sub>cl</sub></span>, level ice thickness <span class="html-italic">h<sub>l</sub></span>, keel width <span class="html-italic">w<sub>k</sub></span>, and keel draft <span class="html-italic">h<sub>k</sub></span> [<a href="#B24-applsci-11-05749" class="html-bibr">24</a>].</p> Full article ">Figure 4
<p>Illustration of a ship and ice ridge interaction process.</p> Full article ">Figure 5
<p>Density function for the thickness of the consolidated layer <span class="html-italic">h<sub>cl</sub></span> fitted to the measurements.</p> Full article ">Figure 6
<p>Density function for the flexural strength for first-year level ice <span class="html-italic">σ<sub>f</sub></span>, fitted to measurements.</p> Full article ">Figure 7
<p>Fit of PDF for the first-year level ice crushing strength <span class="html-italic">σ<sub>c,</sub></span>, versus measured data.</p> Full article ">Figure 8
<p>The circle in normalized space with radius <span class="html-italic">β<sub>F</sub></span> (<b>a</b>) and the resulting design contour line in the physical domain (<b>b</b>) for a case with <span class="html-italic">N</span><sub>50<span class="html-italic">years</span></sub> = 250,000.</p> Full article ">Figure 9
<p>Effect on the shape of the contour lines caused by increasing correlation between the flexural strength and the consolidated layer thickness (for a specific value of the return period, which is N = 50 years for the present case).</p> Full article ">Figure 10
<p>Example of computed deformations and von Mises stress levels caused by the impact of an ice ridge on the upward sloping hull of a mobile drilling unit (MODU).</p> Full article ">Figure 11
<p>The contour surface based on three parameters: thickness of consolidated layer, flexural strength, and crushing strength, for a return period of 50 years.</p> Full article ">Figure 12
<p>Three-dimensional 50-year contours that represent level surfaces corresponding to different keel drafts <span class="html-italic">h<sub>k</sub></span>.</p> Full article ">Figure 13
<p>Mass–velocity contour for growlers/bergy bits corresponding to <span class="html-italic">N</span><sub>1</sub> = 750.</p> Full article ">Figure 14
<p>Sequence of 2D mass–velocity contours for increasing (deterministic) ship velocity. (<b>a</b>) 3D surface and (<b>b</b>) 2D projections.</p> Full article ">Figure 14 Cont.
<p>Sequence of 2D mass–velocity contours for increasing (deterministic) ship velocity. (<b>a</b>) 3D surface and (<b>b</b>) 2D projections.</p> Full article ">Figure 15
<p>Level curves of constant kinetic energy versus mass–velocity contours.</p> Full article ">Figure 16
<p>Examples of simulated damage caused by impacting ice floe/ridge. (<b>a</b>)ULS/ALS-type of damage and (<b>b</b>) ALS-type of damage.</p> Full article ">Figure 17
<p>Examples of numerical models of ice features of different geometries: (<b>a</b>) growler, (<b>b</b>) bergy bit, and (<b>c</b>) iceberg.</p> Full article ">
10 pages, 560 KiB  
Article
Cephalometric Changes Following Maxillary Expansion with Ni-Ti Leaf Springs Palatal Expander and Rapid Maxillary Expander: A Retrospective Study
by Valentina Lanteri, Andrea Abate, Davide Cavagnetto, Alessandro Ugolini, Francesca Gaffuri, Alessandro Gianolio and Cinzia Maspero
Appl. Sci. 2021, 11(12), 5748; https://doi.org/10.3390/app11125748 - 21 Jun 2021
Cited by 17 | Viewed by 2761
Abstract
Background: The aim of this study is to evaluate and compare, through bidimensional cephalometry, skeletal and dental changes obtained from a rapid maxillary expander (RME) and a Ni-Ti leaf spring expander (Leaf) and compare them with an untreated control group. Methods: Records consisted [...] Read more.
Background: The aim of this study is to evaluate and compare, through bidimensional cephalometry, skeletal and dental changes obtained from a rapid maxillary expander (RME) and a Ni-Ti leaf spring expander (Leaf) and compare them with an untreated control group. Methods: Records consisted of lateral cephalograms obtained before and after maxillary expansion of patients that underwent orthodontic treatment at the Department of Biomedical, Surgical and Dental Sciences. The Leaf expander group consisted of 9 males (mean age = 7.5 ± 0.9 years old) and 11 females (mean age = 8.2 ± 0.6 years old). The RME group of the present study was composed of 11 males (mean age = 7.8 ± 0.6 years old) and 12 females (mean age = 8.1 ± 0.5 years old). Digital cephalograms were traced using Dolphin Imaging software v.11.1 (Dolphin Imaging and Management Solutions; Los Angeles, CA, USA), which calculated all reported measurements. Each subject was assigned a random identification number, and the examiner was blinded to the subject when measuring. The difference between the two experimental times in all groups was evaluated using the Student’s t-test for dependent variables. The difference between the two evaluation times in each group for all the variables was used to perform a one-way ANOVA test between the three groups. Results: No statistically significant difference was noted, apart from the angle between the upper incisor and the SN and PP planes, which showed an average decrease of 3.25 and 2.55, respectively, and the angle between the lower incisors and the mandibular plane, which showed an average increase of 2.85 degrees. The one-way ANOVA showed no statistically significant difference between the three groups. Conclusions: It appears that the leaf expander and the RME present similar effects such as dental and skeletal changes. Full article
(This article belongs to the Special Issue Recent Developments in Orthodontics on Craniofacial Orthopedics)
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<p>Description of the cephalometric points included in this study. S = Sella; N = nasion; ANS = anterior nasal spine; PNS = posterior nasal spine; A = Point A (most concave point of the anterior maxilla); B = Point B (most concave point of the mandibular symphysis); U1 a = upper incisor root apex; L1 apex = lower incisor root apex; U1 i = incisal edge of the upper incisor; L1 i = incisal edge of the lower incisor; Me = Menton (most inferior point of mandibular symphysis); Gn = gnathion (midpoint between the pogonion point and Me); Ar = (junction between the inferior surface of the cranial base and the posterior border of the ascending rami of the mandible.</p> Full article ">
12 pages, 5217 KiB  
Article
Research on Rotary Parts Vibration Suppression Based on Coaxiality Measurement and Unbalance Constraint
by Yongmeng Liu, Ruirui Li, Chuanzhi Sun, Ze Chen, Yingjie Mei, Pinghuan Xiao, Xiaoming Wang and Chengtian Li
Appl. Sci. 2021, 11(12), 5747; https://doi.org/10.3390/app11125747 - 21 Jun 2021
Cited by 4 | Viewed by 2262
Abstract
To suppress the vibration of rotary parts, this paper established an unbalanced vibration response control model of rotary parts based on rotating axis coordinate system. This model considered the stacking transformation of geometric parameter errors and mass parameter errors of single stage rotor. [...] Read more.
To suppress the vibration of rotary parts, this paper established an unbalanced vibration response control model of rotary parts based on rotating axis coordinate system. This model considered the stacking transformation of geometric parameter errors and mass parameter errors of single stage rotor. First of all, the centroid transfer model based on the actual rotation axis was established, and the unbalanced excitation force vector of each stage of the rotor was studied. Secondly, the unbalanced excitation force vector of each stage of the rotor is substituted into the model of assembly vibration control based on the double constraints optimization strategy. Finally, the simulation analysis and the vibration experiment of three-stage rotor stacking assembly is carried out. The results show that the vibration of the engine rotor can be effectively suppressed by adjusting the assembly phase of the rotors, and the vibration amplitude of the combined rotor assembled by the double constraint optimization assembly strategy is 22.5% less than the vibration amplitude assembled by the direct assembly strategy. Besides, the coaxiality and the unbalance are reduced by 44.1% and 78.4%, which fully shows the advantages of the double constraint optimization assembly strategy. Full article
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<p>Multistage rotor centroid vector transformation model.</p> Full article ">Figure 2
<p>Simulation model of rotor vibration.</p> Full article ">Figure 3
<p>Vibration amplitude control diagram of drive end under working speed of rotary parts rotor system: (<b>a</b>) Three-dimensional diagram of vibration amplitude changing with assembly phase; (<b>b</b>) Projection diagram of vibration amplitude changing with assembly phase.</p> Full article ">Figure 4
<p>Comparison of vibration amplitude under three assembly models.</p> Full article ">Figure 5
<p>Vibration amplitude under different assembly strategy: (<b>a</b>) Vibration amplitude of drive end; (<b>b</b>) Vibration amplitude of non-drive end.</p> Full article ">Figure 6
<p>Test device diagram of rotor geometric parameters and mass parameters: (<b>a</b>) Precision air bearing turntable; (<b>b</b>) Experimental rotor.</p> Full article ">Figure 7
<p>Rotary parts vibration test device.</p> Full article ">Figure 8
<p>Vibration amplitude of rotary parts rotor under different assembly strategies.</p> Full article ">
11 pages, 4447 KiB  
Article
Hierarchical Electrode Switching Device Design for Distributed Single-Channel Electrical Resistivity Tomography System
by Xin Xia, Yu-Ying Pan, Xiao-Lei Liu and Yong-Gang Jia
Appl. Sci. 2021, 11(12), 5746; https://doi.org/10.3390/app11125746 - 21 Jun 2021
Cited by 1 | Viewed by 2096
Abstract
An electrode switching device (ESD) is one of the most important components of electrical resistivity tomography (ERT). It is a ligament and relay between a testing circuit and testing electrodes. Existing ESD uses a plane structure to realize the interconnection between ports and [...] Read more.
An electrode switching device (ESD) is one of the most important components of electrical resistivity tomography (ERT). It is a ligament and relay between a testing circuit and testing electrodes. Existing ESD uses a plane structure to realize the interconnection between ports and testing electrodes. Taking Wenner testing as an example, each electrode needs four additional switches. In this report, a new hardware saving ESD (HESD) is made with a hierarchical structure for a single-channel distributed ERT. HESD has two-layered switches to realize the conversion process. The first layer of 16 switches can realize four pairs of unrepeated connection between four ports—AMNB and four Lines—L1–L4. The second layer establishes the non-overlapping joints between four lines—L1–L4 and four testing electrodes. Each electrode only needs one switch for an 1D test, which has been wildly used in soil science, ocean probing, and contaminated surveys, and an odd number layer test. With the newly designed HESD, three fourths of the cost of hardware (switch) was saved compared with the conventional ESD. In addition, with two more switches, HESD was able to complete a 2D survey. The new two-layer HESD saves hardware costs and shows advantages in maintenance, system tests, and miniaturization, especially when many electrodes are required in an ERT system, which is very common in practice. Full article
(This article belongs to the Section Electrical, Electronics and Communications Engineering)
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<p>Structure of ESD for the distributed ERT system.</p> Full article ">Figure 2
<p>Power supply interface schematic for ERT in ESD, designed by Zheng Cai-Jun [<a href="#B23-applsci-11-05746" class="html-bibr">23</a>].</p> Full article ">Figure 3
<p>Circuit schematic for one electrode connection in the ESD, designed by Zheng Cai-Jun [<a href="#B23-applsci-11-05746" class="html-bibr">23</a>].</p> Full article ">Figure 4
<p>System structure of ESD and the system structure of TESD (<b>a</b>) [<a href="#B24-applsci-11-05746" class="html-bibr">24</a>]; desire to realize the system structure of HESD (<b>b</b>). (<b>a</b>), Each group of colored lines represents the connection to each electrode, respectively. (<b>b</b>), SS1: switch structures 1; SS2: switch structures 2.</p> Full article ">Figure 5
<p>Topology of the distributed structure: TESD design (<b>a</b>) [<a href="#B24-applsci-11-05746" class="html-bibr">24</a>]; the first layer and the first stage of design of the second layer in HESD (<b>b</b>); Switch control map for E1-A, E2-M, E3-N, and E4-B (<b>c</b>).</p> Full article ">Figure 6
<p>Distributed cell structure for four electrodes in one cell [<a href="#B23-applsci-11-05746" class="html-bibr">23</a>].</p> Full article ">Figure 7
<p>Topology structure of ESD for implementing all layer tests.</p> Full article ">Figure 8
<p>Schematic diagram of I/O ports and electrode connections with the distributed cell.</p> Full article ">Figure 9
<p>Actual instrument: main control circuit (<b>a</b>); distributed circuit (<b>b</b>).</p> Full article ">Figure A1
<p>ERT profile.</p> Full article ">
14 pages, 1619 KiB  
Article
Effects of Air Route Alternation and Display Design on an Operator’s Situation Awareness, Task Performance and Mental Workload in Simulated Flight Tasks
by Hao Chen, Liping Pang, Xiaoru Wanyan, Shuang Liu, Yufeng Fang and Da Tao
Appl. Sci. 2021, 11(12), 5745; https://doi.org/10.3390/app11125745 - 21 Jun 2021
Cited by 9 | Viewed by 2951
Abstract
Air route alternation caused by unexpected events in abnormal or emergency situations often produces adverse consequences on an operator’s cognition and behavior in flight tasks. Under such a circumstance, it is especially necessary to examine the utility of the interaction displays usually designed [...] Read more.
Air route alternation caused by unexpected events in abnormal or emergency situations often produces adverse consequences on an operator’s cognition and behavior in flight tasks. Under such a circumstance, it is especially necessary to examine the utility of the interaction displays usually designed based on the routine environment. This study was aimed to investigate the effects of air route alternation and display design on operators’ situation awareness (SA), task performance and mental workload during simulated flight tasks. Twenty-four participants attended an experiment where they were instructed to perform simulated flight tasks with three types of display designs in both air-route-as-planned and air-route-altered conditions. Subjective measures, behavioral measures and eye movement measures were adopted to assess the participants’ SA, task performance and mental workload. The results show that unexpected air route alternation increases mental workload as well as deteriorates the SA and task performance due to the gap between attention resource demand and supply. Reducing the demand of the operator’s attention resource should be the focus when coping with unexpected events in abnormal situations. In addition, reasonable information layout, such as a center-layout design of the critical decision-making information, is more important than information salience for improving the SA and task performance in abnormal situations. Nevertheless, indicators with a high-salience design, such as a more open window design and immersive design, are still worth recommending. Full article
(This article belongs to the Topic Industrial Engineering and Management)
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<p>Simulated flight platform (<b>left</b>) and eye tracker system (<b>right</b>).</p> Full article ">Figure 2
<p>Experimental independent variables of air route alternation (<b>left</b>) and display design (<b>right</b>) with areas of interests (AoIs).</p> Full article ">Figure 3
<p>Measurement indices in different display designs under conditions of air-route-as-planned and air-route-altered. (<b>a</b>) SA score of 3D-SART; (<b>b</b>) Attention resource surplus (ARS) of 3D-SART; (<b>c</b>) Overall operation accuracy; (<b>d</b>) Altitude operation accuracy; (<b>e</b>) Fixation rate in AoI 1 (Overall); (<b>f</b>) Fixation rate in AoI 3 (Altitude).</p> Full article ">
11 pages, 1617 KiB  
Article
Theoretical Analysis and Experimental Research on the Adjustment for Pre-Stress Deviation of the Cable-Bar Tensile Structures
by Lianmeng Chen, Yijie Liu, Yihong Zeng, He Zhang and Yiyi Zhou
Appl. Sci. 2021, 11(12), 5744; https://doi.org/10.3390/app11125744 - 21 Jun 2021
Viewed by 1975
Abstract
Construction errors are unavoidable in actual cable-bar tensile structures. Construction error analysis, evaluation, and especially adjustment theories were still in their infancy. For the improvement of the situation, based on the equilibrium equation, physical equation, and geometric equation for pin-joint structures, the member [...] Read more.
Construction errors are unavoidable in actual cable-bar tensile structures. Construction error analysis, evaluation, and especially adjustment theories were still in their infancy. For the improvement of the situation, based on the equilibrium equation, physical equation, and geometric equation for pin-joint structures, the member length deviation was adopted as the variable, and the relationship between the pre-stress deviation and member length deviation was determined. On this basis, an adjustment method was devised for the pre-stress deviations under three different conditions, and an evaluation of the effectiveness for pre-stress deviation adjustment was proposed. Finally, a 5-m diameter cable-bar tensile structure model was designed and constructed for simulation. The research results demonstrated that the adjusted pre-stress deviations of measuring points can be effectively corrected, and the theoretical results generally coincided with the experimental results. The adjustment effects of pre-stress deviation varied with the number of adjustment cables, and the adjustment effectiveness gradually decreased with the reduction of the number of adjustment cables. Different adjustment schemes produced different structural deformations, and it was necessary to prioritize the adjustment scheme that resulted in lower peak values of internal forces and shape changes during the adjustment process. The research results indicated that the correctness and validity of the proposed error analysis and adjustment method of pre-stress deviation, and its practical application in the guidance of construction errors analysis, pre-stress deviation adjustments, and evaluation of adjustment results of actual pretension structures. Full article
(This article belongs to the Section Civil Engineering)
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<p>A cable-bar tensile structure for Seoul Olympics.</p> Full article ">Figure 2
<p>A cable-bar tensile structure for Atlanta Olympics.</p> Full article ">Figure 3
<p>A cable-bar tensile structure model. (<b>a</b>) The whole model; (<b>b</b>) A symmetrical cable-bar unit.</p> Full article ">Figure 4
<p>Screws connecting to cables and beam.</p> Full article ">Figure 5
<p>Five different schemes with different adjustment cables; (<b>a</b>) scheme 1; (<b>b</b>) scheme 2; (<b>c</b>) scheme 3; (<b>d</b>) scheme 4; (<b>e</b>) scheme 5.</p> Full article ">Figure 5 Cont.
<p>Five different schemes with different adjustment cables; (<b>a</b>) scheme 1; (<b>b</b>) scheme 2; (<b>c</b>) scheme 3; (<b>d</b>) scheme 4; (<b>e</b>) scheme 5.</p> Full article ">
13 pages, 333 KiB  
Article
Compositional Distributional Semantics with Syntactic Dependencies and Selectional Preferences
by Pablo Gamallo
Appl. Sci. 2021, 11(12), 5743; https://doi.org/10.3390/app11125743 - 21 Jun 2021
Cited by 5 | Viewed by 2773
Abstract
This article describes a compositional model based on syntactic dependencies which has been designed to build contextualized word vectors, by following linguistic principles related to the concept of selectional preferences. The compositional strategy proposed in the current work has been evaluated on a [...] Read more.
This article describes a compositional model based on syntactic dependencies which has been designed to build contextualized word vectors, by following linguistic principles related to the concept of selectional preferences. The compositional strategy proposed in the current work has been evaluated on a syntactically controlled and multilingual dataset, and compared with Transformer BERT-like models, such as Sentence BERT, the state-of-the-art in sentence similarity. For this purpose, we created two new test datasets for Portuguese and Spanish on the basis of that defined for the English language, containing expressions with noun-verb-noun transitive constructions. The results we have obtained show that the linguistic-based compositional approach turns out to be competitive with Transformer models. Full article
(This article belongs to the Special Issue Rich Linguistic Processing for Multilingual Text Mining)
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<p>Dependency-based analysis of <span class="html-italic">the company fired the employee</span> and left-to-right interpretation process to build the contextualized word senses of the three lexical constituents.</p> Full article ">Figure 2
<p>Dependency-based analysis of <span class="html-italic">the company fired the employee</span> and right-to-left interpretation process to build the contextualized word senses of the three lexical constituents.</p> Full article ">Figure 3
<p>Bar plot with the Spearman scores of the best configurations for each model and language.</p> Full article ">
29 pages, 9910 KiB  
Review
Synthetic Transformations and Medicinal Significance of 1,2,3-Thiadiazoles Derivatives: An Update
by Ali Irfan, Sami Ullah, Ayesha Anum, Nazish Jabeen, Ameer Fawad Zahoor, Hafza Kanwal, Katarzyna Kotwica-Mojzych and Mariusz Mojzych
Appl. Sci. 2021, 11(12), 5742; https://doi.org/10.3390/app11125742 - 21 Jun 2021
Cited by 13 | Viewed by 4613
Abstract
The 1,2,3-thiadiazole moiety occupies a significant and prominent position among privileged heterocyclic templates in the field of medicine, pharmacology and pharmaceutics due to its broad spectrum of biological activities. The 1,2,3-thiadiazole hybrid structures showed myriad biomedical activities such as antifungal, antiviral, insecticidal, antiamoebic, [...] Read more.
The 1,2,3-thiadiazole moiety occupies a significant and prominent position among privileged heterocyclic templates in the field of medicine, pharmacology and pharmaceutics due to its broad spectrum of biological activities. The 1,2,3-thiadiazole hybrid structures showed myriad biomedical activities such as antifungal, antiviral, insecticidal, antiamoebic, anticancer and plant activators, etc. In the present review, various synthetic transformations and approaches are highlighted to furnish 1,2,3-thiadiazole scaffolds along with different pharmaceutical and pharmacological activities by virtue of the presence of the 1,2,3-thiadiazole framework on the basis of structure–activity relationship (SAR). The discussion in this review article will attract the attention of synthetic and medicinal researchers to explore 1,2,3-thiadiazole structural motifs for future therapeutic agents. Full article
(This article belongs to the Special Issue Heterocyclic Compounds with Potential Biological Activity: From Synthesis to Application)
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<p>Structures of different isomeric forms of thiadiazole (<b>1</b>–<b>4</b>).</p> Full article ">Figure 2
<p>Commercial drugs based on different thiadiazole scaffolds (<b>5</b>–<b>14</b>).</p> Full article ">Figure 3
<p>Structures of antiviral drugs <b>89</b>–<b>91</b>.</p> Full article ">Figure 4
<p>Thioacetanilide based 1,2,3-thiadiazole scaffold <b>92</b> exhibiting maximum anti-HIV potential.</p> Full article ">Figure 5
<p>Anti-HIV activity of 5-(2,4-dibromophenyl)-1,2,3-thiadiazole <b>93</b>.</p> Full article ">Figure 6
<p>Antiviral activity of 1,2,3-thiadiazole <b>94</b>.</p> Full article ">Figure 7
<p>Antiviral activity of terazole derivatives <b>95</b>–<b>98</b>.</p> Full article ">Figure 8
<p>Antiviral 1,2,3-thiadiazole scaffold <b>99</b>.</p> Full article ">Figure 9
<p>1,2,3-thiadiazoles <b>100</b> and <b>101</b> with anti-TMV activity.</p> Full article ">Figure 10
<p>1,2,3-Thiadiazole scaffolds <b>102</b> and <b>103</b> with anti-TMV activity.</p> Full article ">Figure 11
<p>Antiviral activity of 4-(3,4-dichlorophenyl)-1,2,3-thiadiazole scaffold <b>104</b>.</p> Full article ">Figure 12
<p>Clinical anticancer drugs <b>105</b>–<b>108</b>.</p> Full article ">Figure 13
<p>Antitumor effect of 1,2,3-thiadiales <b>109</b> and <b>110</b>.</p> Full article ">Figure 14
<p>Anticancer activity of 2-thioamide-1,2,3-thiadiazole <b>111</b> and <b>112</b>.</p> Full article ">Figure 15
<p>Anticancer activity of 1,2,3-thiadiazole derivative <b>113</b> against U2OS and HeLa cell lines.</p> Full article ">Figure 16
<p>1,2,3-Thiadiazole dehydroepiandrosterone derivative <b>114</b> as new antitumor agents.</p> Full article ">Figure 17
<p>Known insecticidal agents <b>115</b>–<b>117</b>.</p> Full article ">Figure 18
<p>Insecticidal activity of <span class="html-italic">N</span>-<span class="html-italic">tert</span>-butyl-<span class="html-italic">N</span>,<span class="html-italic">N</span>′-diacylhydrazines <b>118</b> and <b>119</b>.</p> Full article ">Figure 19
<p>Insecticide Eβf 1,2,3-thiadiazole carboxamides <b>120</b>–<b>112</b>.</p> Full article ">Figure 20
<p>Ethers of pyrazole oximes <b>123</b> and <b>124</b> with insecticidal properties.</p> Full article ">Figure 21
<p>Substituted 4-methyl-1,2,3-thiadiazole derivatives with insecticidal properties against <span class="html-italic">Aphis laburni</span>.</p> Full article ">Figure 22
<p>Amoebicidal commercial dugs <b>128</b>–<b>130</b>.</p> Full article ">Figure 23
<p>The most active antiamoebic 1,2,3-thiadiazoles <b>131</b> and <b>132</b>.</p> Full article ">Figure 24
<p>Structures of commercially available plant activators <b>133</b>–<b>135</b>.</p> Full article ">Figure 25
<p>Potential new plant activator with thieno [2,3-<span class="html-italic">d</span>]-1,2,3-thiadiazoles <b>136</b> and <b>137</b>.</p> Full article ">Figure 26
<p>Structures of commercial antifungal drugs <b>138</b>–<b>140</b>.</p> Full article ">Figure 27
<p>Novel potent 1,2,3-thiadiazole fungicides <b>141</b> and <b>142</b>.</p> Full article ">Figure 28
<p>Antifungal activity of triazole moiety containing 1,2,3-thiadiazolew <b>143</b> and <b>144</b>.</p> Full article ">Figure 29
<p>Piperidine based 1,2,3-Thiadiazole <b>145</b> with moderate antifungal activity.</p> Full article ">Figure 30
<p>1,2,3-thiadiazoles with broad antifungal activity.</p> Full article ">Figure 31
<p>Antifungal benzo[1,2,3]thiadiazole-7-carboxylate derivative <b>148</b>.</p> Full article ">Figure 32
<p>The most active 4-methyl-1,2,3-thiadiazole-5-carboxamides.</p> Full article ">Scheme 1
<p>Construction of pyrazole-based thiadiazoles <b>18</b>.</p> Full article ">Scheme 2
<p>Synthesis of 1,2,3-thiadiazoles <b>21</b> from semicarbazone.</p> Full article ">Scheme 3
<p>Synthesis of 1,2,3-thiadiazole derivatives from 2-oxoallobetulin.</p> Full article ">Scheme 4
<p>Synthesis of 1,2,3-thiadiazoles via ionic liquid support.</p> Full article ">Scheme 5
<p>Reaction of N-tosylhydrazones (<b>29</b>) with elemental sulfur for the synthesis of thiadiazole (<b>31</b>).</p> Full article ">Scheme 6
<p>Synthesis of triazole-based 1,2,3-thiadiazole derivatives (<b>49</b>).</p> Full article ">Scheme 7
<p>5-methyl substituted thiadiazole derivatives (<b>45</b>) synthesis via U-4CR.</p> Full article ">Scheme 8
<p>Preparation of tetrazole ring containing thiadiazole derivatives (<b>49</b>).</p> Full article ">Scheme 9
<p>I<sub>2</sub>/CuCl<sub>2</sub> mediated catalysis for the construction of thiadiazoles (<b>53</b>).</p> Full article ">Scheme 10
<p>Synthesis of acrylamide derivatives of thiadiazoles (<b>59</b>).</p> Full article ">Scheme 11
<p>Acetohydrazone as starting precursor for the preparation of thiadiazoles (<b>64</b>).</p> Full article ">Scheme 12
<p>Synthesis of new carboxylate derivatives of thiadiazoles (<b>67</b>).</p> Full article ">Scheme 13
<p>Synthesis of substituted 1,2,3-thiadiazole (<b>71</b>) via cross-coupling mediated by I<sub>2</sub>/DMSO.</p> Full article ">Scheme 14
<p>Synthesis of 1,2,3-thiadiazoles (<b>75</b>) via nucleophilic addition.</p> Full article ">Scheme 15
<p>Photocatalysis reaction of azoalkenes (<b>76</b>) with KSCN to afford 1,2,3-thiadiazoles (<b>77</b>).</p> Full article ">Scheme 16
<p>Preparation of fused 1,2,3-thiadiazoles via ONSH mechanism.</p> Full article ">Scheme 17
<p>I<sub>2</sub>/O<sub>2</sub> mediated synthesis of 1,2,3-thiadiazoles (<b>82</b>).</p> Full article ">Scheme 18
<p><span class="html-italic">N</span>-Heteroarylamidines based thiadiazole analogues (<b>85</b>).</p> Full article ">Scheme 19
<p>Synthesis of 1,2,3-thiadiazoles from in situ generated azoalkenes with S<sub>3</sub><sup>•−</sup> via a cascade process.</p> Full article ">
17 pages, 9170 KiB  
Article
Vision-Based Path Guidance to Achieve Dies-Free Roller Hemming Process
by Yi-Ping Huang, Bor-Tung Jiang, Chia-Hung Wu and Jen-Yuan Chang
Appl. Sci. 2021, 11(12), 5741; https://doi.org/10.3390/app11125741 - 21 Jun 2021
Cited by 4 | Viewed by 3536
Abstract
Due to its high production flexibility, roller hemming has become the mainstream process for forming and joining metal sheets in the automotive industry. The traditional roller hemming process requires specific dies to support sheet metal parts and repeated offline manual adjustment of hemming [...] Read more.
Due to its high production flexibility, roller hemming has become the mainstream process for forming and joining metal sheets in the automotive industry. The traditional roller hemming process requires specific dies to support sheet metal parts and repeated offline manual adjustment of hemming routes, resulting in high die costs, high time consumption, and excessive labor inputs. The universal platform presented in this paper could replace specific dies to effectively reduce costs and expand production flexibility. To reach this objective, a vision-based automatic compensation path to achieve a dies-free roller hemming process is proposed and investigated in this paper. Hand–eye sensor modules assisted by multi-coordinate synchronization calibration for the roller hemming were designed to reconstruct three-dimensional (3-D) shape data of the incoming materials. Results from the proposed system were validated with experimental measurements for the sheet offset and the compensation of the arm hemming position, showing that the single-axis error can be reduced to ≤0.1 mm. Full article
(This article belongs to the Special Issue Metal Forming)
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<p>A universal fixed platform for a hemming process: (<b>a</b>) front view; (<b>b</b>) enlarged view of upper part.</p> Full article ">Figure 2
<p>The hemming tool: (<b>a</b>) the traditional single roller; (<b>b</b>) an active double-roller with different shapes of upper rollers.</p> Full article ">Figure 3
<p>The design of the proposed quick-change sensor module: (<b>a</b>) schematic illustration; (<b>b</b>) photograph of the module on a robot arm.</p> Full article ">Figure 4
<p>Schematic illustration of the quick-change sensor module and the quick-change interface.</p> Full article ">Figure 5
<p>Schematic drawing of the hand–eye coordinate system and location of the sensor frame.</p> Full article ">Figure 6
<p>Hand–eye conversion calculation process.</p> Full article ">Figure 7
<p>The calibration procedure.</p> Full article ">Figure 8
<p>(<b>a</b>) A schematic drawing and (<b>b</b>) photograph showing the hand–eye calibration device used in this study.</p> Full article ">Figure 9
<p>Photographs showing the calibration procedure by manipulating the robot to calibrate (<b>a</b>) the tool center point (TCP) with different postures and (<b>b</b>) the world frame with the same posture.</p> Full article ">Figure 10
<p>Photographs showing the (<b>a</b>) robot arm reference point calibration with the reference ball and (<b>b</b>) hand–eye relationship calibration with the optic calibration plate.</p> Full article ">Figure 11
<p>Illustrated example of estimating the actual hemming point.</p> Full article ">Figure 12
<p>The optic calibration plate and reference ball coordinate measurement results.</p> Full article ">Figure 13
<p>The calibration data displayed by the self-developed hand–eye relationship calibration software.</p> Full article ">Figure 14
<p>The verified standard block and its location on the calibration module.</p> Full article ">Figure 15
<p>Steps for the verification and values of the accuracy of the visual sensor.</p> Full article ">Figure 16
<p>Workflow (<b>a</b>) and photographs illustrating the manipulation of the robot arm for the sensing module to capture positions and orientations at the six points of the car hood sheet metal (<b>b</b>).</p> Full article ">Figure 17
<p>Screenshoot of the software to visualize the real-time compensation path for hemming.</p> Full article ">Figure 18
<p>Schematic drawings showing (<b>a</b>) the sheet metal hemming experiment and (<b>b</b>) the definition of the contour edge roll-in/roll-out displacement error.</p> Full article ">Figure 19
<p>Measured roll-in/roll-out displacement error of after being hemmed.</p> Full article ">Figure 20
<p>Photography and schematics for surface flatness measurement of the hemmed edge.</p> Full article ">Figure 21
<p>Measured surface flatness of the hemmed edge.</p> Full article ">
18 pages, 4178 KiB  
Article
Affinity-Based Task Scheduling on Heterogeneous Multicore Systems Using CBS and QBICTM
by Sohaib Iftikhar Abbasi, Shaharyar Kamal, Munkhjargal Gochoo, Ahmad Jalal and Kibum Kim
Appl. Sci. 2021, 11(12), 5740; https://doi.org/10.3390/app11125740 - 21 Jun 2021
Cited by 8 | Viewed by 3008
Abstract
This work presents the grouping of dependent tasks into a cluster using the Bayesian analysis model to solve the affinity scheduling problem in heterogeneous multicore systems. The non-affinity scheduling of tasks has a negative impact as the overall execution time for the tasks [...] Read more.
This work presents the grouping of dependent tasks into a cluster using the Bayesian analysis model to solve the affinity scheduling problem in heterogeneous multicore systems. The non-affinity scheduling of tasks has a negative impact as the overall execution time for the tasks increases. Furthermore, non-affinity-based scheduling also limits the potential for data reuse in the caches so it becomes necessary to bring the same data into the caches multiple times. In heterogeneous multicore systems, it is essential to address the load balancing problem as all cores are operating at varying frequencies. We propose two techniques to solve the load balancing issue, one being designated “chunk-based scheduler” (CBS) which is applied to the heterogeneous systems while the other system is “quantum-based intra-core task migration” (QBICTM) where each task is given a fair and equal chance to run on the fastest core. Results show 30–55% improvement in the average execution time of the tasks by applying our CBS or QBICTM scheduler compare to other traditional schedulers when compared using the same operating system. Full article
(This article belongs to the Special Issue Applications of Parallel Computing)
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<p>Affinity-based scheduling mechanism via CBS and QBICTM.</p> Full article ">Figure 2
<p>Prior and posterior tasks dependencies using Bayesian generative model.</p> Full article ">Figure 3
<p>Allocation of tasks to cores by CBS.</p> Full article ">Figure 4
<p>Working mechanism of QBICTM scheduler.</p> Full article ">Figure 5
<p>Prior and posterior task dependencies based on different parameter values. (<b>a</b>) Non-informative uniform prior when parameter value is 20; (<b>b</b>) posterior tasks dependency for parameter value 20; (<b>c</b>) non-informative uniform prior when parameter value is 60; (<b>d</b>) posterior tasks dependency for parameter value 60; (<b>e</b>) non-informative uniform prior when parameter value is 80; (<b>f</b>) posterior tasks dependency for parameter value 80.</p> Full article ">Figure 5 Cont.
<p>Prior and posterior task dependencies based on different parameter values. (<b>a</b>) Non-informative uniform prior when parameter value is 20; (<b>b</b>) posterior tasks dependency for parameter value 20; (<b>c</b>) non-informative uniform prior when parameter value is 60; (<b>d</b>) posterior tasks dependency for parameter value 60; (<b>e</b>) non-informative uniform prior when parameter value is 80; (<b>f</b>) posterior tasks dependency for parameter value 80.</p> Full article ">Figure 6
<p>Average execution time comparisons between CBS and OS scheduler for the factorial program.</p> Full article ">Figure 7
<p>Comparison of average execution times between the CBS and the OS schedulers.</p> Full article ">Figure 8
<p>Average improvement ratio in execution time by comparison with the traditional OS scheduler.</p> Full article ">
19 pages, 41887 KiB  
Article
Building Information Modeling Methods for Post-Earthquake Retrofitting Visualization of Buildings Using Augmented Reality
by Zhansheng Liu and Wenyan Bai
Appl. Sci. 2021, 11(12), 5739; https://doi.org/10.3390/app11125739 - 21 Jun 2021
Cited by 7 | Viewed by 4637
Abstract
The post-earthquake retrofitting and repair process of a building is a key factor in improving its seismic capability. A thorough understanding of retrofitting methods and processes will aid in repairing post-earthquake buildings and improving seismic resilience. This study aims to develop a visualization [...] Read more.
The post-earthquake retrofitting and repair process of a building is a key factor in improving its seismic capability. A thorough understanding of retrofitting methods and processes will aid in repairing post-earthquake buildings and improving seismic resilience. This study aims to develop a visualization framework for the post-earthquake retrofitting of buildings which builds models based on building information modeling (BIM) and realizes visualization using augmented reality (AR). First, multi-level representation methods and coding criteria are used to process the models for a damaged member. Then, an information collection template is designed for integrating multi-dimensional information, such as damage information, retrofitting methods, technical solutions, and construction measures. Subsequently, a BIM model is presented in three dimensions (3D) using AR. Finally, the visualization process is tested through experiments, which demonstrate the feasibility of using the framework to visualize the post-earthquake retrofitting of a building. Full article
(This article belongs to the Special Issue Buildings Operation and Maintenance)
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<p>Building information modeling-augmented reality (BIM-AR)-based construction visualization method framework.</p> Full article ">Figure 2
<p>Visualization process of post-earthquake retrofitting of building.</p> Full article ">Figure 3
<p>Information collection elements.</p> Full article ">Figure 4
<p>Information integration list.</p> Full article ">Figure 5
<p>Information transfer flow in AR.</p> Full article ">Figure 6
<p>BIM-AR information combination flow.</p> Full article ">Figure 7
<p>Uploading data to the AR platform.</p> Full article ">Figure 8
<p>Viewing the model at 1:1 ratio: (<b>A</b>) Project list; (<b>B</b>) AR model; (<b>C</b>) Identify the reference; (<b>D</b>) View the model at 1:1 ratio.</p> Full article ">Figure 9
<p>Viewing the BIM information and video: (<b>A</b>) Place the model; (<b>B</b>) View the model; (<b>C</b>) View detailed information of damage; (<b>D</b>) Identify the thumbnail; (<b>E</b>) Display the video.</p> Full article ">Figure 10
<p>Benefits of the proposed framework.</p> Full article ">
16 pages, 354 KiB  
Article
Antimicrobial Properties, Cytotoxic Effects, and Fatty Acids Composition of Vegetable Oils from Purslane, Linseed, Luffa, and Pumpkin Seeds
by Spyridon A. Petropoulos, Ângela Fernandes, Ricardo C. Calhelha, Youssef Rouphael, Jovana Petrović, Marina Soković, Isabel C. F. R. Ferreira and Lillian Barros
Appl. Sci. 2021, 11(12), 5738; https://doi.org/10.3390/app11125738 - 21 Jun 2021
Cited by 28 | Viewed by 5741
Abstract
In the present study, the antimicrobial and cytotoxic activities, as well as the fatty acids composition in vegetable seed oils from linseed, purslane, luffa, and pumpkin were evaluated. For this purpose, two linseed oils and one luffa oil were commercially obtained, while purslane [...] Read more.
In the present study, the antimicrobial and cytotoxic activities, as well as the fatty acids composition in vegetable seed oils from linseed, purslane, luffa, and pumpkin were evaluated. For this purpose, two linseed oils and one luffa oil were commercially obtained, while purslane and pumpkin oils were obtained from own cultivated seeds. The results showed a variable fatty acids composition among the tested oils, with α-linolenic, linoleic, oleic, palmitic, and stearic acid being the most abundant compounds. In regards to particular oils, linseed oils were a rich source of α-linolenic acid, luffa and pumpkin oil were abundant in linoleic acid, while purslane oil presented a balanced composition with an almost similar amount of both fatty acids. Luffa oil was the most effective against two of the tested cancer cell lines, namely HeLa (cervical carcinoma) and NCI-H460 (non-small cell lung cancer), while it also showed moderate toxicity against non-tumor cells (PLP2 cell line). Regarding the antibacterial activity, linseed oil 3 and pumpkin oil showed the highest activity against most of the tested bacteria (especially against Enterobacter cloacae and Escherichia coli) with MIC and MBC values similar to the used positive controls (E211 and E224). All the tested oils showed significant antifungal activities, especially luffa and pumpkin oil, and for most of the tested fungi they were more effective than the positive controls, as for example in the case of Aspergillus versicolor, A. niger, and Penicillium verrucosum var. cyclopium. In conclusion, the results of our study showed promising antimicrobial and cytotoxic properties for the studied seed oils which could be partly attributed to their fatty acids composition, especially the long-chain ones with 12–18 carbons. Full article
(This article belongs to the Special Issue Antimicrobial Substances in Plants: Discovery of New Compounds, Properties, Food and Agriculture Applications, and Sustainable Recovery)
16 pages, 7048 KiB  
Article
Research on the Processing Method of Acoustic Focusing Cavities Based on the Temperature Gradient
by Liqun Wu, Yafei Fan, Hongcheng Wang, Linan Zhang, Yizheng Sheng, Yajing Wang and Yaxing Wang
Appl. Sci. 2021, 11(12), 5737; https://doi.org/10.3390/app11125737 - 21 Jun 2021
Cited by 2 | Viewed by 2140
Abstract
Aiming at the key factors affecting the quality and efficiency of high-energy in-beam machining, this paper studies the broadband acoustic focusing effect based on a discrete temperature gradient. Firstly, the basic theory and mathematical model of temperature-controlled acoustic focusing are established. Secondly, the [...] Read more.
Aiming at the key factors affecting the quality and efficiency of high-energy in-beam machining, this paper studies the broadband acoustic focusing effect based on a discrete temperature gradient. Firstly, the basic theory and mathematical model of temperature-controlled acoustic focusing are established. Secondly, the acoustic focusing effect is achieved by combining the design of metasurfaces and discrete temperature. Then, the acoustic pressure and intensity distribution of acoustic focusing under a discrete temperature gradient are simulated and experimentally studied. The results show that the phase delay of transmission and reflection of acoustic wave covers the 2π interval by changing the temperature in different transmission units, which provides a theoretical basis for the processing of the acoustic focusing cavity. Full article
(This article belongs to the Section Acoustics and Vibrations)
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<p>Schematic diagram of temperature-controlled focusing principle.</p> Full article ">Figure 2
<p>Schematic diagram of transmission unit.</p> Full article ">Figure 3
<p>Acoustic pressure distribution of transmission unit at different temperatures.</p> Full article ">Figure 4
<p>Distribution of the metasurface on the <span class="html-italic">y</span>-axis.</p> Full article ">Figure 5
<p>The delay of acoustic phase corresponding to temperature.</p> Full article ">Figure 6
<p>Distribution of transmission units in the <span class="html-italic">y</span>-direction.</p> Full article ">Figure 7
<p>Spatial distribution of acoustic pressure field through focusing lens at 20 kHz.</p> Full article ">Figure 8
<p>Spatial distribution of acoustic intensity field through focusing lens at 20 kHz.</p> Full article ">Figure 9
<p>Spatial distributions of acoustic intensity field through focusing lens at (<b>a</b>) 28 kHz, (<b>b</b>) 35 kHz, (<b>c</b>) 40 kHz, (<b>d</b>) 45 kHz, <b>(e)</b> 50 kHz, and <b>(f)</b> 55 kHz.</p> Full article ">Figure 10
<p>Spatial distributions of acoustic intensity field through focusing lens at (<b>a</b>) 28 kHz and (<b>b</b>) 35 kHz.</p> Full article ">Figure 11
<p>Schematic diagram of plane wave propagation in reflection unit.</p> Full article ">Figure 12
<p>Acoustic pressure distribution of plane wave in seven reflection units with different temperatures.</p> Full article ">Figure 13
<p>Phase delay corresponding to different temperatures.</p> Full article ">Figure 14
<p>Reflection wave focusing model diagram.</p> Full article ">Figure 15
<p>Spatial distribution of acoustic intensity field through focusing lens at 20 kHz.</p> Full article ">Figure 16
<p>Spatial distributions of acoustic intensity field through focusing lens at (<b>a</b>) 28 kHz, (<b>b</b>) 35 kHz, (<b>c</b>) 40 kHz, and (<b>d</b>) 45 kHz.</p> Full article ">Figure 17
<p>Spatial distribution of acoustic intensity field through focusing lens at 50 kHz.</p> Full article ">Figure 18
<p>The influence of frequency on the sound intensity at the focal point of transmitted and reflected waves.</p> Full article ">Figure 19
<p>Spatial distribution of acoustic intensity field through focusing lens at 50 kHz.</p> Full article ">Figure 20
<p>Spatial distributions of acoustic intensity field through focusing lens at (<b>a</b>) 28 kHz and (<b>b</b>) 35 kHz.</p> Full article ">
62 pages, 5092 KiB  
Review
Complex Systems, Emergence, and Multiscale Analysis: A Tutorial and Brief Survey
by Jianbo Gao and Bo Xu
Appl. Sci. 2021, 11(12), 5736; https://doi.org/10.3390/app11125736 - 21 Jun 2021
Cited by 12 | Viewed by 7338
Abstract
Mankind has long been fascinated by emergence in complex systems. With the rapidly accumulating big data in almost every branch of science, engineering, and society, a golden age for the study of complex systems and emergence has arisen. Among the many values of [...] Read more.
Mankind has long been fascinated by emergence in complex systems. With the rapidly accumulating big data in almost every branch of science, engineering, and society, a golden age for the study of complex systems and emergence has arisen. Among the many values of big data are to detect changes in system dynamics and to help science to extend its reach, and most desirably, to possibly uncover new fundamental laws. Unfortunately, these goals are hard to achieve using black-box machine-learning based approaches for big data analysis. Especially, when systems are not functioning properly, their dynamics must be highly nonlinear, and as long as abnormal behaviors occur rarely, relevant data for abnormal behaviors cannot be expected to be abundant enough to be adequately tackled by machine-learning based approaches. To better cope with these situations, we advocate to synergistically use mainstream machine learning based approaches and multiscale approaches from complexity science. The latter are very useful for finding key parameters characterizing the evolution of a dynamical system, including malfunctioning of the system. One of the many uses of such parameters is to design simpler but more accurate unsupervised machine learning schemes. To illustrate the ideas, we will first provide a tutorial introduction to complex systems and emergence, then we present two multiscale approaches. One is based on adaptive filtering, which is excellent at trend analysis, noise reduction, and (multi)fractal analysis. The other originates from chaos theory and can unify the major complexity measures that have been developed in recent decades. To make the ideas and methods better accessed by a wider audience, the paper is designed as a tutorial survey, emphasizing the connections among the different concepts from complexity science. Many original discussions, arguments, and results pertinent to real-world applications are also presented so that readers can be best stimulated to apply and further develop the ideas and methods covered in the article to solve their own problems. This article is purported both as a tutorial and a survey. It can be used as course material, including summer extensive training courses. When the material is used for teaching purposes, it will be beneficial to motivate students to have hands-on experiences with the many methods discussed in the paper. Instructors as well as readers interested in the computer analysis programs are welcome to contact the corresponding author. Full article
(This article belongs to the Special Issue Advancing Complexity Research in Earth Sciences and Geography)
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Figure 1
<p>Deterministic vs. structural complexity.</p> Full article ">Figure 2
<p>Pareto-distributed balls, where <math display="inline"><semantics> <mrow> <mi>α</mi> <mo>=</mo> <mn>1.8</mn> </mrow> </semantics></math>.</p> Full article ">Figure 3
<p>Complementary cumulative distribution function (CCDF) for the forest fires in USA and China, where the size of a fire is measured by its area A. The data for USA are the sizes of individual fires from 1997 to 2018, while those for China are the total annual size of forest fires in the 30 provinces from 1998 to 2017.</p> Full article ">Figure 4
<p>Complementary cumulative distribution function (CCDF) for the products of volcanic eruptions in the Holocene: (<b>a</b>) tephra volume (km<math display="inline"><semantics> <msup> <mrow/> <mn>3</mn> </msup> </semantics></math>) and dense rock equivalent (DRE) (km<math display="inline"><semantics> <msup> <mrow/> <mn>3</mn> </msup> </semantics></math>), and (<b>b</b>) volcanic sulfate (data were from [<a href="#B54-applsci-11-05736" class="html-bibr">54</a>]).</p> Full article ">Figure 5
<p>Distribution for the ratio between sex offenders and the total population in (<b>a</b>) Ohio and (<b>b</b>) New York (adapted from [<a href="#B59-applsci-11-05736" class="html-bibr">59</a>]).</p> Full article ">Figure 6
<p>Phase space diagram of religious participation vs. happiness for the USA based on wave 7 of the World Value Survey Data.</p> Full article ">Figure 7
<p>Successive transformation of a unit circle by the Henon map. The unit circle is represented by 36,000 points with equal arc spacing. These points are then taken as initial conditions for the Henon map. Successive (<math display="inline"><semantics> <mrow> <mi>i</mi> <mo>=</mo> <mn>1</mn> <mo>,</mo> <mn>2</mn> <mo>,</mo> <mo>⋯</mo> <mo>,</mo> <mn>5</mn> </mrow> </semantics></math>) images of the unit circle (discarding initial conditions which lead to divergence of the iterations) are shown from left to right and top to bottom in the figure.</p> Full article ">Figure 8
<p>Evolution of point clouds in the chaotic Lorenz system: magenta, red, green, and blue correspond to <math display="inline"><semantics> <mrow> <mi>t</mi> <mo>=</mo> <mn>0</mn> <mo>,</mo> <mn>2</mn> <mo>,</mo> <mn>4</mn> <mo>,</mo> <mn>6</mn> </mrow> </semantics></math>, respectively.</p> Full article ">Figure 9
<p>Error growth in the logistic map.</p> Full article ">Figure 10
<p>Bifurcation diagram for the logistic map; (<b>b</b>) is an enlargement of the little rectangular box indicated by the arrow in (<b>a</b>).</p> Full article ">Figure 11
<p>Bifurcation diagram for the Henon map.</p> Full article ">Figure 12
<p>Embedding of the harmonic oscillator.</p> Full article ">Figure 13
<p><math display="inline"><semantics> <mrow> <mo>Λ</mo> <mo>(</mo> <mi>k</mi> <mo>)</mo> </mrow> </semantics></math> vs. <span class="html-italic">k</span> curves for the Lorenz system. When <math display="inline"><semantics> <mrow> <mi>w</mi> <mo>=</mo> <mn>1</mn> </mrow> </semantics></math>, the slope of the curve severely underestimates the largest Lyapunov exponent. When <span class="html-italic">w</span> is increased to 54, the slope correctly estimates the largest Lyapunov exponent (reproduced from [<a href="#B74-applsci-11-05736" class="html-bibr">74</a>]).</p> Full article ">Figure 14
<p>Time-dependent exponent curves for the chaotic Lorenz data (<b>left</b>) and IID random variables (<b>right</b>), where the curves, from bottom up, correspond to shells <math display="inline"><semantics> <mrow> <mo stretchy="false">(</mo> <msup> <mn>2</mn> <mrow> <mo>−</mo> <mo stretchy="false">(</mo> <mi>i</mi> <mo>+</mo> <mn>1</mn> <mo stretchy="false">)</mo> </mrow> </msup> <mo>/</mo> <mn>2</mn> <mo>,</mo> <msup> <mn>2</mn> <mrow> <mo>−</mo> <mi>i</mi> <mo>/</mo> <mn>2</mn> </mrow> </msup> <mo>,</mo> <mrow/> <mn>1</mn> <mo>=</mo> <mn>1</mn> <mo>,</mo> <mn>2</mn> <mo>,</mo> <mo>⋯</mo> <mo>,</mo> <mn>9</mn> <mo stretchy="false">)</mo> </mrow> </semantics></math> (adapted from [<a href="#B74-applsci-11-05736" class="html-bibr">74</a>]).</p> Full article ">Figure 15
<p>2D phase diagram for essential tremor data (<b>left</b>) and time-dependent exponent curves (<b>right</b>), where the curves, from bottom up, correspond to shells <math display="inline"><semantics> <mrow> <mo stretchy="false">(</mo> <msup> <mn>2</mn> <mrow> <mo>−</mo> <mo stretchy="false">(</mo> <mi>i</mi> <mo>+</mo> <mn>1</mn> <mo stretchy="false">)</mo> </mrow> </msup> <mo>/</mo> <mn>2</mn> <mo>,</mo> <msup> <mn>2</mn> <mrow> <mo>−</mo> <mi>i</mi> <mo>/</mo> <mn>2</mn> </mrow> </msup> <mo>,</mo> <mspace width="3.33333pt"/> <mn>1</mn> <mo>=</mo> <mn>1</mn> <mo>,</mo> <mn>2</mn> <mo>,</mo> <mo>⋯</mo> <mo>,</mo> <mn>9</mn> <mo stretchy="false">)</mo> </mrow> </semantics></math> (adapted from [<a href="#B80-applsci-11-05736" class="html-bibr">80</a>]).</p> Full article ">Figure 16
<p>Clean (open triangles) and noisy (filled circles) trajectories for (<b>a</b>) <math display="inline"><semantics> <mrow> <mi>μ</mi> <mo>=</mo> <mn>3.55</mn> </mrow> </semantics></math> and (<b>b</b>) <math display="inline"><semantics> <mrow> <mi>μ</mi> <mo>=</mo> <mn>3.74</mn> </mrow> </semantics></math> (reproduced from [<a href="#B118-applsci-11-05736" class="html-bibr">118</a>]).</p> Full article ">Figure 17
<p>Time-dependent exponent curves for the noisy Logistic map: (<b>a</b>) <math display="inline"><semantics> <mrow> <mi>μ</mi> <mo>=</mo> <mn>3.55</mn> </mrow> </semantics></math> and <math display="inline"><semantics> <mrow> <mi>σ</mi> <mo>=</mo> <mn>0.01</mn> </mrow> </semantics></math>; (<b>b</b>) <math display="inline"><semantics> <mrow> <mi>μ</mi> <mo>=</mo> <mn>3.63</mn> </mrow> </semantics></math> and <math display="inline"><semantics> <mrow> <mi>σ</mi> <mo>=</mo> <mn>0.005</mn> </mrow> </semantics></math>; (<b>c</b>) <math display="inline"><semantics> <mrow> <mi>μ</mi> <mo>=</mo> <mn>3.74</mn> </mrow> </semantics></math> and <math display="inline"><semantics> <mrow> <mi>σ</mi> <mo>=</mo> <mn>0.002</mn> </mrow> </semantics></math>; and (<b>d</b>) <math display="inline"><semantics> <mrow> <mi>μ</mi> <mo>=</mo> <mn>3.83</mn> </mrow> </semantics></math> and <math display="inline"><semantics> <mrow> <mi>σ</mi> <mo>=</mo> <mn>0.005</mn> </mrow> </semantics></math>. Six curves, from the bottom up, correspond to shells <math display="inline"><semantics> <mrow> <mo>(</mo> <msup> <mn>2</mn> <mrow> <mo>−</mo> <mo>(</mo> <mi>i</mi> <mo>+</mo> <mn>1</mn> <mo>)</mo> <mo>/</mo> <mn>2</mn> </mrow> </msup> <mo>,</mo> <msup> <mn>2</mn> <mrow> <mo>−</mo> <mi>i</mi> <mo>/</mo> <mn>2</mn> </mrow> </msup> <mo>)</mo> </mrow> </semantics></math> with <math display="inline"><semantics> <mrow> <mi>i</mi> <mo>=</mo> <mn>7</mn> </mrow> </semantics></math>, 8, 9, 10, 11, and 12 (reproduced from [<a href="#B118-applsci-11-05736" class="html-bibr">118</a>]).</p> Full article ">Figure 18
<p>Logarithmic displacement curves illustrating the mechanism for noise-induced chaos. Each group actually consists of three curves, corresponding to shells <math display="inline"><semantics> <mrow> <mo>(</mo> <msup> <mn>2</mn> <mrow> <mo>−</mo> <mo>(</mo> <mi>i</mi> <mo>+</mo> <mn>1</mn> <mo>)</mo> <mo>/</mo> <mn>2</mn> </mrow> </msup> <mo>,</mo> <msup> <mn>2</mn> <mrow> <mo>−</mo> <mi>i</mi> <mo>/</mo> <mn>2</mn> </mrow> </msup> <mo>)</mo> </mrow> </semantics></math> with <span class="html-italic">i</span> = 12, 13, and 14. They basically collapse on each other. The parameters for the four groups are (<b>a</b>) <math display="inline"><semantics> <mrow> <mi>μ</mi> <mo>=</mo> <mn>3.74</mn> </mrow> </semantics></math> and <math display="inline"><semantics> <mrow> <mi>σ</mi> <mo>=</mo> <mn>0.0003</mn> </mrow> </semantics></math>; (<b>b</b>) <math display="inline"><semantics> <mrow> <mi>μ</mi> <mo>=</mo> <mn>3.83</mn> </mrow> </semantics></math> and <math display="inline"><semantics> <mrow> <mi>σ</mi> <mo>=</mo> <mn>0.001</mn> </mrow> </semantics></math>; (<b>c</b>) <math display="inline"><semantics> <mrow> <mi>μ</mi> <mo>=</mo> <mn>3.63</mn> </mrow> </semantics></math> and <math display="inline"><semantics> <mrow> <mi>σ</mi> <mo>=</mo> <mn>0.0003</mn> </mrow> </semantics></math>; and (<b>d</b>) <math display="inline"><semantics> <mrow> <mi>μ</mi> <mo>=</mo> <mn>3.55</mn> </mrow> </semantics></math> and <math display="inline"><semantics> <mrow> <mi>σ</mi> <mo>=</mo> <mn>0.0005</mn> </mrow> </semantics></math>. To separate these four groups (<b>a</b>–<b>d</b>) of curves from each other, they are shifted by 2, 1, −0.5, and −0.2 units, respectively, where a positive number indicates shifting upward, and a negative number indicates shifting downward. All four groups of curves are well modeled by <math display="inline"><semantics> <mrow> <mo form="prefix">ln</mo> <msup> <mi>k</mi> <mi>α</mi> </msup> </mrow> </semantics></math> with <math display="inline"><semantics> <mrow> <mi>α</mi> <mo>=</mo> <mn>1.5</mn> </mrow> </semantics></math>, 1.0, 1.0, and 0.25 (reproduced from [<a href="#B118-applsci-11-05736" class="html-bibr">118</a>]).</p> Full article ">Figure 19
<p>Number of citations of pioneering papers on chaos synchronization (data collected in March 2019).</p> Full article ">Figure 20
<p>Standard Cantor set (<b>a</b>) and its variants (<b>b</b>–<b>d</b>). See the text for details.</p> Full article ">Figure 21
<p>Schematic showing how a multiplicative multifractal is constructed.</p> Full article ">Figure 22
<p>Sea clutter amplitude data: (<b>a</b>) is the original data without target, (<b>b</b>) is the original data with a primary target, and (<b>c</b>,<b>d</b>) are the modeled data.</p> Full article ">Figure 23
<p>Construction of 2D multiplicative multifractals: (<b>a</b>) schematic rule, (<b>b</b>) an example.</p> Full article ">Figure 24
<p>Analysis of the annual sea surface temperature (SST) data: (<b>a</b>) the original data and trend signals of different resolutions, (<b>b</b>) the residual signals.</p> Full article ">Figure 25
<p>Denoising of the chaotic Lorenz signal: (<b>a</b>) phase diagrams constructed from the the clean and the noisy signal, which are marked as green and red, respectively; (<b>b</b>) the filtered signal obtained by a chaos-based approach; (<b>c</b>) the filtered signal obtained by the adaptive algorithm; and (<b>d</b>) the filtered signal obtained by a wavelet method.</p> Full article ">Figure 26
<p>Electricity consumption analysis: (<b>a</b>) raw data (blue) and the trend signal (red); (<b>b</b>) enlargement of the high-frequency load data showing the diurnal cycle (blue) and its filtered band-pass data (red); (<b>c</b>) 2D phase diagrams constructed from the data shown in (<b>b</b>); (<b>d</b>) PSD for the raw, detrended, and denoised data, which are marked by blue, red, and green, respectively.</p> Full article ">Figure 27
<p>Schematic of DFA.</p> Full article ">Figure 28
<p>AFA of power load data: (<b>a</b>) an example of <math display="inline"><semantics> <mrow> <msub> <mo form="prefix">log</mo> <mn>2</mn> </msub> <mi>F</mi> <mrow> <mo>(</mo> <mi>w</mi> <mo>)</mo> </mrow> </mrow> </semantics></math> vs. <math display="inline"><semantics> <mrow> <msub> <mo form="prefix">log</mo> <mn>2</mn> </msub> <mi>w</mi> </mrow> </semantics></math> for the load data of an arbitrarily chosen day, (<b>b</b>) temporal variation of the Hurst parameter (red) and the rescaled temperature (black).</p> Full article ">Figure 28 Cont.
<p>AFA of power load data: (<b>a</b>) an example of <math display="inline"><semantics> <mrow> <msub> <mo form="prefix">log</mo> <mn>2</mn> </msub> <mi>F</mi> <mrow> <mo>(</mo> <mi>w</mi> <mo>)</mo> </mrow> </mrow> </semantics></math> vs. <math display="inline"><semantics> <mrow> <msub> <mo form="prefix">log</mo> <mn>2</mn> </msub> <mi>w</mi> </mrow> </semantics></math> for the load data of an arbitrarily chosen day, (<b>b</b>) temporal variation of the Hurst parameter (red) and the rescaled temperature (black).</p> Full article ">Figure 29
<p>A schematic showing how a small distance between two nearby trajectories grows with time.</p> Full article ">Figure 30
<p>(<b>a</b>) A three inverter ring oscillator. (<b>b</b>) A ring oscillator driven by an external periodic signal. The resistor-capacitor stages may represent either discrete components or the finite bandwidth of non-ideal inverters.</p> Full article ">Figure 31
<p>Typical oscillations displayed by an experimentally implemented ring oscillator. (<b>a</b>) Self oscillations occur with the input held constant above the threshold. (<b>b</b>) Slow driving produces periodic bursts of self oscillation. (<b>c</b>) Faster driving produces an irregular oscillation.</p> Full article ">Figure 32
<p>SDLE calculated from the experimental time series of <math display="inline"><semantics> <msub> <mi>v</mi> <mn>1</mn> </msub> </semantics></math> (blue), <math display="inline"><semantics> <msub> <mi>v</mi> <mn>2</mn> </msub> </semantics></math> (green), and <math display="inline"><semantics> <msub> <mi>v</mi> <mn>3</mn> </msub> </semantics></math> (red).</p> Full article ">Figure 33
<p>Intermittent chaos in the Umpqua river. Shown in (<b>a1</b>,<b>a2</b>) are the error growth curves and SDLE curves, respectively. The blue curves are for the original data, while the red curves are for the filtered data. The embedding parameters used in the computation are <math display="inline"><semantics> <mrow> <mi>m</mi> <mo>=</mo> <mn>6</mn> </mrow> </semantics></math>, <math display="inline"><semantics> <mrow> <mi>L</mi> <mo>=</mo> <mn>3</mn> </mrow> </semantics></math>. Three different shells specified by Equation (<a href="#FD40-applsci-11-05736" class="html-disp-formula">40</a>) are used. These curves collapse on each other, except when <span class="html-italic">t</span> is small. This highlights that the computational results are essentially independent of the initial shells chosen.</p> Full article ">Figure 34
<p>Epileptic seizure detection from continuous EEG data of a patient, illustrating that SDLE can serve as a basis to unify commonly used complexity measures. Shown in the figure are the temporal variations of (<b>a</b>) <math display="inline"><semantics> <msub> <mi>λ</mi> <mrow> <mi>small</mi> <mo>−</mo> <mi>ϵ</mi> </mrow> </msub> </semantics></math>, (<b>b</b>) <math display="inline"><semantics> <msub> <mi>λ</mi> <mrow> <mi>large</mi> <mo>−</mo> <mi>ϵ</mi> </mrow> </msub> </semantics></math>, (<b>c</b>) the LE, (<b>d</b>) the <math display="inline"><semantics> <msub> <mi>K</mi> <mn>2</mn> </msub> </semantics></math> entropy, (<b>e</b>) the <math display="inline"><semantics> <msub> <mi>D</mi> <mn>2</mn> </msub> </semantics></math>, and (<b>f</b>) the Hurst parameter. Seizure occurrence times were determined by clinical experts and were indicated here as the vertical dashed lines.</p> Full article ">Figure 35
<p>Long-range correlations (or inertia) of political processes in four countries: (<b>a</b>) USA, (<b>b</b>) China, (<b>c</b>) Turkey, and (<b>d</b>) Indonesia. The blue curve has a temporal resolution of 1 month, while the red one has a temporal resolution of 1 year.</p> Full article ">
20 pages, 27234 KiB  
Article
Present Tectonic Dynamics of the Geological Structural Setting of the Eastern Part of the Adriatic Region Obtained from Geodetic and Geological Data
by Marko Pavasović, Almin Đapo, Marijan Marjanović and Boško Pribičević
Appl. Sci. 2021, 11(12), 5735; https://doi.org/10.3390/app11125735 - 21 Jun 2021
Cited by 4 | Viewed by 3230
Abstract
The Adriatic microplate has always attracted scientific attention, and various studies on the geodynamics of this area have been performed over the years. With the development of global navigation satellite system (GNSS) technology in the last 30 years, most significant research in this [...] Read more.
The Adriatic microplate has always attracted scientific attention, and various studies on the geodynamics of this area have been performed over the years. With the development of global navigation satellite system (GNSS) technology in the last 30 years, most significant research in this field has used it as the primary source of data on geodynamic movements. However, apart from a few global positioning system (GPS) campaigns conducted in the 1990s, the measurements had a low spatiotemporal density. Therefore, the eastern side of the Adria region or the territory of the Republic of Croatia was usually omitted from the results presented in the various published papers. A study of this literature concluded that the territory of Croatia represents a kind of scientific gap and that denser measurement data from GPS/GNSS stations could be used to supplement the geodynamic picture of the area in question. Thus, GPS/GNSS measurements from 83 stations (geodynamic, reference, and POS’ GPS/GNSS) all over Croatia and neighboring countries for a period of almost 20 years (1994–2013) were collected and processed with Bernese software to obtain a unique database of relative velocities. From the geological perspective, the most important and latest insights on the recent geological structural setting, tectonic movements, most active faults, and relationships and movements of structures were taken into account. It was important to compare the geodetic and geological data, observe the present tectonic dynamics of the geological structural setting, and determine the causes of the obtained directions of movement. The research presented in this paper, based on a combination of geodetic and geological data, was conducted to broaden the current knowledge of the present tectonic dynamics of the geological structural setting of the eastern part of the Adriatic region. Full article
(This article belongs to the Section Earth Sciences)
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Figure 1

Figure 1
<p>Low coverage of GNSS-derived velocities in the area of the Republic of Croatia represents a scientific gap (modified from [<a href="#B3-applsci-11-05735" class="html-bibr">3</a>].</p> Full article ">Figure 2
<p>Relative velocity vectors (horizontal component v<sub>H</sub>) of 83 stations for the territory of Croatia, Slovenia, Hungary, and Montenegro concerning station GRAZ (all velocity vectors have the same scale). CRODYN includes the Croatian stations that are most frequently observed in campaigns from <a href="#applsci-11-05735-t001" class="html-table">Table 1</a>.</p> Full article ">Figure 3
<p>Recent geological structure setting and basic directions of movement of structural parts along the surface according to geological data. Legend: 1—Regional geological structural units: a—Adriatic microplate (AMP) and Adriatic unit (A); b—Southern Alps (SA), Prealps (AF), and Sava faults (SF); c—Dinarides: Dinaric and Supradinaric (SD); d—Pannonian Basin: Western (WPB), Southern (SPB), and Central part (CPB); 2—The most important faults bordering regional structural units: Trieste–Učka–Vis fault (1), Vis–South Adriatic fault (2), Postojna–Rijeka–Vinodol fault and extension, Velebit–Sinj fault (3), Mosor–Biokovo–Dubrovnik fault (4), Fela–Sava fault and continuation, Ljubljana–Karlovac–Slunj fault (5), southern boundary fault of the Pannonian Basin (6), fault of the Southern Alps (7), Zagreb fault (8), Periadriatic fault and continuation and Drava fault (9), Sava fault (10), Zagreb–Vinkovci fault (11), and Barcs–Baranja fault (12); 3—other important faults; 4—reverse faults; 5—faults of indeterminate character; 6—direction of horizontal movement along the fault; and 7—direction of movement of structure parts along the surface according to geological data; 8—earthquake epicentres, intensity IX and X, yr. 361–1900; 9—earthquake epicentres yr. 1901–1970, M 5.7-6.1 and M 6.2-6.6; 10—earthquake epicenter M 6.2, south of Zagreb in 2020.</p> Full article ">Figure 4
<p>(<b>a</b>) Amplitudes and directions of annual velocities at geodetic stations (2008–2013). Legend (<b>a</b>): 1—velocity amplitudes; 2—movement directions at geodetic stations; 3—maximum and minimum movement amplitudes. (<b>b</b>) Amplitudes and directions of annual velocities around Dubrovnik. Legend (<b>b</b>): 1—direction of annual velocities at geodetic points in mm/yr; 2—amplitudes greater than 4 (a), 5 (b), and 7 (c) mm/yr at geodetic stations in Dubrovnik DUBM(1), DUBR(2), DUBI, and DUB2 (3); 3—major fault at Mosor–Biokovo–Dubrovnik (4a), bordering regional structural units and its main branch (4b); 4—faults extending along local reverse structures and branches of major faults; 5—reverse faults; 6—the movement directions of structural parts along the faults, according to geological measurements.</p> Full article ">Figure 5
<p>(<b>a</b>) Slope angles and directions of annual velocities at geodetic points (for 2008–2013 period). Legend: 1—directions of annual velocity at geodetic points in mm/yr; 2—spatially positive movements (uplift) greater than 0°, 20°, 30°, and 60°; 3—spatially negative movements (descending) greater than 0°, −30°; 4—maximum and minimum slope angles. (<b>b</b>) Slope angles and directions of annual velocities on Mt. Srđ near Dubrovnik. Legend: 1—directions and slope angles of annual velocity at points DUBM, DUBR, DUBI, and DUB2; 2—faults with an indication of reverse movement; 3—main branch of Mosor–Biokovo–Dubrovnik fault (4b); 4—layers of predominantly Cretaceous carbonate sediments.</p> Full article ">Figure 6
<p>(<b>a</b>) Velocity vectors directions on geodetic points in Croatia, averaged velocity vector directions on geodetic points in Italy and seismic activity from 2004 to 2021. Legend: 1—annual velocity directions on geodetic points in Croatia; 2—averaged velocity directions on geodetic points in Italy; 3—earthquake epicentres in the period 2004—2021 with M &gt; 3. (EMSC). (<b>b</b>) velocity directions on geodetic points in Italy—part (from [<a href="#B3-applsci-11-05735" class="html-bibr">3</a>]).</p> Full article ">Figure 7
<p>(<b>a</b>) Recent geological structural setting and tectonic activity in Dinaric space and Adriatic regional structural unit. Legend: 1—regional geologic structural units: a—Adriatic microplate (AMP) and Adriatic (A) unit, b—Dinarides: Dinaric (D) and Supradinaric (SD); 2—the most prominent structural units within the regional geological structural units with reverse faults of opposite vergence along fault walls: Čičarija–Učka (1), Velebit (2), Mosor–Biokovo (3), Dinara–Kamešnica (4), Kapela (5), Grmeč (6), Golija (7), Petrova Gora–Kozara (8); 3—major large structures; 4—the most important faults adjacent to regional structural units and parts of the Pannonian Basin, along with the Trieste–Učka–Vis fault (1), Vis–South Adriatic fault (2), Ilirska Bistrica–Rijeka–Vinodol fault and continuation of Velebit–Sinj fault (3), Mosor–Biokovo–Dubrovnik fault (4), Ljubljana–Karlovac–Slunj fault (5), and southern boundary fault of the Pannonian Basin (6); 5—other important faults; 6—reverse faults; 7—faults of indeterminate character; 8—direction of horizontal movement along the fault; 9—direction of movement of structure parts along the surface according to geological data; 10—directions of annual velocity at geodetic points in mm/yr. (<b>b</b>) Seismotectonic profile of Rijeka area. Legend: 1—earthquake hypocenters with a magnitude of (a) &lt;4, (b) 4–5, and (c) &gt;5.2; 2—seismotectonically active area; 3—faults included in the seismotectonically active areas and the most important Ilirska Bistrica–Rijeka–Vinodol fault (3); 4—other seismotectonically active faults; 5—the probable footwall surface of carbonate rock complex; 6—layers of rocks along the surface; 7—rocks on the surface: Pg (Paleogene)—limestones and flysch; K (Cretaceous)—predominantly limestones and dolomites; J (Jurassic)—limestones and dolomites; T (Triassic)—dolomites, limestones, marls, sandstones, and eruptives; and Pz (Paleozoic)—mainly shale, limestones, conglomerates, and sandstones.</p> Full article ">Figure 8
<p>Gravimetric residual anomalies in the area of southern Adriatic islands and Biokovo. Legend: 1—Isolines of anomalies in mgal; 2—the highest positive and negative values of mgal; 3—major Mosor-Biokovo-Dubrovnik fault (4), borders of regional structural units; 4—faults extending along large local elevated reverse structures of vergences toward S and SSW–SW; 5—mark for reverse faults.</p> Full article ">Figure 9
<p>Mosor–Biokovo–Dubrovnik fault zone (4a,b), its branches, and steep relief of Biokovo near Makarska, caused by compression in the contact area of regional structural units and reverse shifts in hanging wall of fault (Google Earth). Legend: 1—Mosor–Biokovo–Dubrovnik fault (4a,b); 2—fault branches; 3—basic direction of movement of parts of the Adriatic regional structural unit based on geodetic data; 4—the reverse movement of the hanging wall of the Mosor–Biokovo–Dubrovnik fault (4a,b).</p> Full article ">Figure 10
<p>Local reverse structure in Crikvenica area due to compression in the contact area of regional structural units (Google Earth). Legend: 1—Major Ilirska Bistrica–Rijeka fault (3a) and its main branch (3b); 2—other faults in the wider zone; 3—reverse faults; and 4—local elevated structure with reverse faults of opposite vergence along their walls.</p> Full article ">Figure 11
<p>(<b>a</b>) Recent geological structural setting and tectonic activity in the contact area of Adriatic microplate, Alps, Dinarides, and Pannonian Basin. Legend: 1—Regional geological structural units: a—Adriatic microplate (AMP) and Adriatic (A) unit, b—Southern Alps (SA), Eastern Alps (EA), Prealps (AF) and Sava faults (SF), c—Dinarides, and Dinarik (D) and Supradinarik (SD) units, d—Pannonian Basin: Western (WPB) and Southern (SPB); 2—major faults adjacent to regional structural units: Trieste–Učka–Vis fault (1), Ilirska Bistrica–Rijeka–Vinodol fault (3), Fella–Sava fault and continuation of Ljubljana–Karlovac–Slunj (5), southern boundary fault of Pannonian Basin (6), SA fault (7), Zagreb fault (8), Periadriatic fault and continuation of Drava fault (9); 3—other important faults; 4—reverse faults; 5—faults of indeterminate character; 6—the direction of horizontal movement along the fault; 7—movement direction of the Adriatic microplate (AMP); 8—direction of annual velocity at geodetic points in mm/yr. (<b>b</b>) Seismic activity: 1a—major faults: Ljubljana–Karlovac–Slunj fault (5), Zagreb fault (8), Periadriatik fault and continuation of Drava fault (9); 1b—other important faults bordering seismotectonically most active structural units in the western part of the Pannonian basin (WPB); 2—the direction of horizontal movement along the fault; 3—earthquake epicentres (a) and earthquake magnitudes (b).</p> Full article ">Figure 12
<p>Recent geological structural setting and tectonic activity in the area of the Pannonian Basin. Legend: 1—Regional geological structural units: Pannonian Basin: Western (WPB), Southern (SPB), and Central (CPB); 2—the most prominent structural units within the regional geological structural units along whose wings are reverse faults of opposite vergence: Petrova gora –Kozara (7), Žumberak–Medvednica (8), Vukomeričke gorice–Šamarica (9), Moslavačka gora Gora (10), Psunj–Dilj gora (11), Papuk (12), and Bilogora (13); 3—large basins: Sava (14), Mura (15), and Drava (16); 4—major faults adjacent to regional structural units and the Sava and Drava Basins: the southern boundary fault of the Pannonian Basin, Zagreb fault (8), Periadriatic fault and continuation of the Drava fault (9), Sava fault (10), Zagreb–Vinkovci fault (11), and Barcs–Baranja fault (12); 5—other important faults; 6—reverse faults; 7—faults of indeterminate character; 8—direction of horizontal movement along the fault; 9—direction of movement of parts of structures along the surface according to geological data; 10—direction of annual velocity at geodetic points in mm/yr.</p> Full article ">Figure 13
<p>Seismic reflection profile of Bilogora. Legend: 1—Seismic reflexes of rocks in depth; 2—footwall surface of Neogene rocks; 3—the probable footwall surface of Paleozoic rocks; 4—faults indicating the movement of hanging wall; 5—Drava fault (9) borders the central and southern parts of the Pannonian Basin; 6—Drava fault zone (9a,b).</p> Full article ">
12 pages, 10291 KiB  
Article
Complementary Metaresonator Sensor with Dual Notch Resonance for Evaluation of Vegetable Oils in C and X Bands
by Ammar Armghan
Appl. Sci. 2021, 11(12), 5734; https://doi.org/10.3390/app11125734 - 21 Jun 2021
Cited by 11 | Viewed by 2340
Abstract
This paper investigates the effect of complementary metaresonator for evaluation of vegetable oils in C and X bands. Tremendously increasing technology demands the exploration of complementary metaresonators for high performance in the related bands. This research probes the complementary mirror-symmetric S resonator (CMSSR) [...] Read more.
This paper investigates the effect of complementary metaresonator for evaluation of vegetable oils in C and X bands. Tremendously increasing technology demands the exploration of complementary metaresonators for high performance in the related bands. This research probes the complementary mirror-symmetric S resonator (CMSSR) that can operate in two bands with compact size and high sensitivity features. The prime motivation behind the proposed technique is to utilize the dual notch resonance to estimate the dielectric constant of the oil under test (OUT). The proposed sensor is designed on a compact 30×25 mm2 and 1.6 mm thick FR-4 substrate. A 50 Ω microstrip transmission line is printed on one side, while a unit cell of CMSSR is etched on the other side of the substrate to achieve dual notch resonance. A Teflon container is attached to CMSSR in the ground plane to act as a pool for the OUT. According to the simulated transmission spectrum, the proposed design manifested dual notch resonance precisely at 7.21 GHz (C band) and 8.97 GHz (X band). A prototype of complementary metaresonator sensor is fabricated and tested using CEYEAR AV3672D vector network analyzer. The comparison of measured and simulated data shows that the difference between the first resonance frequency is 0.01 GHz and the second is 0.04 GHz. Furthermore, a mathematical model is developed for the complementary metaresonator sensor to evaluate dielectric constant of the OUT in terms of the relevant, resonant frequency. Full article
(This article belongs to the Special Issue Advanced Technologies for Microwave and Wireless Sensors)
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<p>Three dimensional view of complementary metaresonator sensor. (<b>a</b>) Top view of the sensor where <span class="html-italic">w</span> = 3 mm, (<b>b</b>) Bottom view of the sensor, (<b>c</b>) Dimetric view of the sensor where <span class="html-italic">h</span> = 1.6 mm.</p> Full article ">Figure 2
<p>The magnitude of transmission (<math display="inline"> <semantics> <msub> <mi>S</mi> <mn>21</mn> </msub> </semantics> </math>) and reflection (<math display="inline"> <semantics> <msub> <mi>S</mi> <mn>11</mn> </msub> </semantics> </math>) coefficients for the metaresonator sensor. The first and second notches have a resonance at 7.21 GHz with notch depth −23.85 dB and 8.97 GHz with notch depth −21.57 dB.</p> Full article ">Figure 3
<p>The phase of transmission (<math display="inline"> <semantics> <msub> <mi>S</mi> <mn>21</mn> </msub> </semantics> </math>) and reflection (<math display="inline"> <semantics> <msub> <mi>S</mi> <mn>11</mn> </msub> </semantics> </math>) coefficients for the metaresonator sensor. Near resonance frequencies, there is sudden change in phase.</p> Full article ">Figure 4
<p>(<b>a</b>) Photograph of CEYEAR AV3672D series vector network for measurement, (<b>b</b>) fabricated prototype of the complementary metaresonator sensor.</p> Full article ">Figure 5
<p>The magnitude of transmission (<math display="inline"> <semantics> <msub> <mi>S</mi> <mn>21</mn> </msub> </semantics> </math>) coefficient for simulated and measured metaresonator sensor. The unloaded <span class="html-italic">Q</span> factor of the first notch is 55.38 and that of the second notch is 21.26.</p> Full article ">Figure 6
<p>Measurement environment (<b>a</b>) dragon lab 10–100 µL adjustable single channel automatic pipette, (<b>b</b>) oil quantity measurement, (<b>c</b>) pouring the OUT into the Teflon container.</p> Full article ">Figure 7
<p>Complementary metaresonator sensor loaded with the OUT.</p> Full article ">Figure 8
<p>The magnitude of transmission (<math display="inline"> <semantics> <msub> <mi>S</mi> <mn>21</mn> </msub> </semantics> </math>) coefficients for the complementary metaresonator sensor due to interaction with different OUT.</p> Full article ">Figure 9
<p>Dielectric constant of OUT versus the resonance frequency of the sensor due to interaction with the OUTs.</p> Full article ">
23 pages, 382 KiB  
Review
Whole-Body Vibration Exercise: A Possible Intervention in the Management of Post COVID-19 Complications?
by Danúbia C. Sá-Caputo, Ana Carolina Coelho-Oliveira, Juliana Pessanha-Freitas, Laisa Liane Paineiras-Domingos, Ana Cristina Rodrigues Lacerda, Vanessa Amaral Mendonça, Anelise Sonza, Redha Taiar, Alessandro Sartorio, Adérito Seixas and Mario Bernardo-Filho
Appl. Sci. 2021, 11(12), 5733; https://doi.org/10.3390/app11125733 - 21 Jun 2021
Cited by 6 | Viewed by 5292
Abstract
COVID-19 infection frequently leaves the infected subjects with impairments of multi-organs, the so-called post COVID-19 syndrome, which needs to be adequately addressed. The perspective of this narrative review is to verify the possible role of whole-body vibration exercise in the post-COVID-19 rehabilitation of [...] Read more.
COVID-19 infection frequently leaves the infected subjects with impairments of multi-organs, the so-called post COVID-19 syndrome, which needs to be adequately addressed. The perspective of this narrative review is to verify the possible role of whole-body vibration exercise in the post-COVID-19 rehabilitation of these patients. Publications reporting the use of WBV exercises to counteract fatigue, muscle weakness, neurological manifestations, pain, quality of life, quality of sleep, lung commitments, and mental conditions in different clinical conditions were selected. Considering all the findings described in the current review, it seems that WBV exercise might be potentially useful and effective in the rehabilitation of post COVID-19 syndrome, being able to positively influence fatigue, muscle weakness, and quality of life without any side-effects. Controlled studies are mandatory to define the best protocols to be proposed, which need to be tailored to the individual and clinical characteristics. Full article
(This article belongs to the Special Issue COVID-19: Impact on Human Health and Behavior)
16 pages, 1612 KiB  
Article
The Logopedic Evaluation of Adult Patients after Orthognathic Surgery
by Anna Lichnowska and Marcin Kozakiewicz
Appl. Sci. 2021, 11(12), 5732; https://doi.org/10.3390/app11125732 - 21 Jun 2021
Cited by 5 | Viewed by 3236
Abstract
Orthodontists correct dental malocclusion, but major facial skeleton deformations (skeletal malocclusion) are often subject to surgical correction. Several speech pathologies are associated with both of the occlusal anomalies mentioned above. The majority of articulation disorders and primary functions cannot be improved without skeletal [...] Read more.
Orthodontists correct dental malocclusion, but major facial skeleton deformations (skeletal malocclusion) are often subject to surgical correction. Several speech pathologies are associated with both of the occlusal anomalies mentioned above. The majority of articulation disorders and primary functions cannot be improved without skeletal correction. This study aimed to investigate the outcome of the multimodal and logopaedics treatment of Polish adults affected by skeletal malocclusion and speech-language pathology. A total of 37 adults affected by skeletal Class II and III malocclusion were included, along with the relationship between the malocclusion and speech deficiency (20 phonemes tested) in the subjects before and after surgical correction. The impact of surgery on pronunciation improvement and types of Polish phonemes most often misarticulated by Polish adults were also examined. Patients underwent combined treatment and received a full speech pathology examination. The treatment improved speech (p < 0.05), but the study did not prove that a specific surgery type was associated with pronunciation improvement. Some patients were provided with speech therapy during childhood, yet most had some minor difficulties with lip and tongue movements. Palatal, alveolar (p < 0.05), fricatives (p < 0.05), and labiodental consonant pronunciation (p < 0.05) improved. The surgical correction of malocclusion leads to better articulation of Polish consonants in adults and improves some primary functions. Full article
(This article belongs to the Special Issue Current Challenges of Oral and Maxillofacial Surgery)
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<p>Final palatal, palatal_pl, and dental consonant articulation was related to the postoperational Total Visual Assessment (<span class="html-italic">p</span> &lt; 0.05). Such a relationship was also observed between dental consonants and total Tongue Efficiency assessed postoperatively (<span class="html-italic">p</span> &lt; 0.05).</p> Full article ">Figure 2
<p>Final dental consonant pronunciation results in patients treated multimodally (higher scores, better speech). Quality of speech depends on specific dental positioning. These pairs show statistically significant differences at the 95.0% confidence level: Open Bite + Protrusion vs. Open Bite + Crowding, Open Bite + Protrusion vs. Open Bite, Open Bite + Protrusion vs. Retrusion + Crowding, Open Bite + Protrusion vs. Diastema, Open Bite + Protrusion vs. Crowding, Retrusion vs. Open Bite, Retrusion vs. Retrusion + Crowding, Retrusion vs. Diastema, Retrusion vs. Crowding, Open Bite + Diastema vs. Open Bite, Open Bite + Diastema vs. Retrusion + Crowding, Open Bite + Diastema vs. Diastema, and Open Bite + Diastema vs. Crowding (<span class="html-italic">p</span> &lt; 0.05). Red brackets indicate statistically significant differences (<span class="html-italic">p</span> &lt; 0.05).</p> Full article ">Figure 3
<p>Components included in the two factors that achieved an eigenvalue higher than 1 (factor analysis). Factor 1 is called Skeletal Consonants (major components highlighted in yellow), and Factor 2 is called Soft Tissue Consonants (major components highlighted in blue). The data for 88 untreated patients.</p> Full article ">Figure 4
<p>Effects of skeletal deformity on Skeletal Consonants and Soft Tissue Consonants. The pronunciation quality of Skeletal Consonants in patients affected by Skeletal Class III was significantly worse than in Class II patients. Red brackets indicate groups between which there is a significant difference in the quality of consonant articulation (<span class="html-italic">p</span> &lt; 0.01).</p> Full article ">Figure 5
<p>The relationship of speech therapy treatment in childhood to consonant pronunciation test results in adult patients affected by skeletal malformations. The red brackets indicate groups between which there is a significant difference in consonant articulation quality (<span class="html-italic">p</span> &lt; 0.05).</p> Full article ">
14 pages, 514 KiB  
Article
Concerto: Dynamic Processor Scaling for Distributed Data Systems with Replication
by Jinsu Lee and Eunji Lee
Appl. Sci. 2021, 11(12), 5731; https://doi.org/10.3390/app11125731 - 21 Jun 2021
Cited by 3 | Viewed by 2360
Abstract
A surge of interest in data-intensive computing has led to a drastic increase in the demand for data centers. Given this growing popularity, data centers are becoming a primary contributor to the increased consumption of energy worldwide. To mitigate this problem, this paper [...] Read more.
A surge of interest in data-intensive computing has led to a drastic increase in the demand for data centers. Given this growing popularity, data centers are becoming a primary contributor to the increased consumption of energy worldwide. To mitigate this problem, this paper revisits DVFS (Dynamic Voltage Frequency Scaling), a well-known technique to reduce the energy usage of processors, from the viewpoint of distributed systems. Distributed data systems typically adopt a replication facility to provide high availability and short latency. In this type of architecture, the replicas are maintained in an asynchronous manner, while the master synchronously operates via user requests. Based on this relaxation constraint of replica, we present a novel DVFS technique called Concerto, which intentionally scales down the frequency of processors operating for the replicas. This mechanism can achieve considerable energy savings without an increase in the user-perceived latency. We implemented Concerto on Redis 6.0.1, a commercial-level distributed key-value store, demonstrating that all associated performance issues were resolved. To prevent a delay in read queries assigned to the replicas, we offload the independent part of the read operation to the fast-running thread. We also empirically demonstrate that the decreased performance of the replica does not cause an increase of the replication lag because the inherent load unbalance between the master and replica hides the increased latency of the replica. Performance evaluations with micro and real-world benchmarks show that Redis saves 32% on average and up to 51% of energy with Concerto under various workloads, with minor performance losses in the replicas. Despite numerous studies of the energy saving in data centers, to the best of our best knowledge, Concerto is the first approach that considers clock-speed scaling at the aggregate level, exploiting heterogeneous performance constraints across data nodes. Full article
(This article belongs to the Special Issue Computational Intelligence, Soft Computing and Communication Networks for Applied Science II)
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<p>Redis architecture. M, R, and S stand for master, replica, and sentinel, respectively.</p> Full article ">Figure 2
<p>Read latency analysis and overall architecture of Redis with Concerto.</p> Full article ">Figure 3
<p>Comparison of the propagation and processing rates of a write operation.</p> Full article ">Figure 4
<p>Write path of master and replica in Redis.</p> Full article ">Figure 5
<p>IOPS with Memtier benchmark.</p> Full article ">Figure 6
<p>Energy consumption with Memtier benchmark.</p> Full article ">Figure 7
<p>IOPS with YCSB.</p> Full article ">Figure 8
<p>Energy consumption with YCSB.</p> Full article ">Figure 9
<p>Read performance for replica.</p> Full article ">
17 pages, 3343 KiB  
Article
Quality-Aware Resource Model Discovery
by Minsu Cho, Gyunam Park, Minseok Song, Jinyoun Lee and Euiseok Kum
Appl. Sci. 2021, 11(12), 5730; https://doi.org/10.3390/app11125730 - 21 Jun 2021
Cited by 2 | Viewed by 2259
Abstract
Context-aware process mining aims at extending a contemporary approach with process contexts for realistic process modeling. Regarding this discipline, there have been several attempts to combine process discovery and predictive process modeling and context information, e.g., time and cost. The focus of this [...] Read more.
Context-aware process mining aims at extending a contemporary approach with process contexts for realistic process modeling. Regarding this discipline, there have been several attempts to combine process discovery and predictive process modeling and context information, e.g., time and cost. The focus of this paper is to develop a new method for deriving a quality-aware resource model. It first generates a resource-oriented transition system and identifies the quality-based superior and inferior cases. The quality-aware resource model is constructed by integrating these two results, and we also propose a model simplification method based on statistical analyses for better resource model visualization. This paper includes tooling support for our method, and one of the case studies on a semiconductor manufacturing process is presented to validate the usefulness of the proposed approach. We expect our work is practically applicable to a range of fields, including manufacturing and healthcare systems. Full article
(This article belongs to the Special Issue Big Data and AI for Process Innovation in the Industry 4.0 Era)
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<p>Overview of the proposed approach.</p> Full article ">Figure 2
<p>Examples of transition systems based on the event log in <a href="#applsci-11-05730-t001" class="html-table">Table 1</a>.</p> Full article ">Figure 2 Cont.
<p>Examples of transition systems based on the event log in <a href="#applsci-11-05730-t001" class="html-table">Table 1</a>.</p> Full article ">Figure 3
<p>An example of the case-annotated transition systems (<math display="inline"><semantics> <mrow> <mi>S</mi> <mo>,</mo> <mi>E</mi> <mo>,</mo> <mi>T</mi> <mo>,</mo> <msup> <mi>A</mi> <mi>s</mi> </msup> <mo>,</mo> <msup> <mi>A</mi> <mi>e</mi> </msup> </mrow> </semantics></math>) with <math display="inline"><semantics> <mrow> <msup> <mrow> <mi>r</mi> <mi>e</mi> <mi>p</mi> </mrow> <mi>s</mi> </msup> <mrow> <mo>(</mo> <mi>σ</mi> <mo>)</mo> </mrow> <mo>=</mo> <mrow> <mo>{</mo> <mrow> <msub> <mi>π</mi> <mi>a</mi> </msub> <mrow> <mo>(</mo> <mrow> <mi>σ</mi> <mrow> <mo>(</mo> <mrow> <mrow> <mo>|</mo> <mi>σ</mi> <mo>|</mo> </mrow> </mrow> <mo>)</mo> </mrow> </mrow> <mo>)</mo> </mrow> </mrow> <mo>}</mo> </mrow> </mrow> </semantics></math> and <math display="inline"><semantics> <mrow> <mi>r</mi> <mi>e</mi> <msup> <mi>p</mi> <mi>e</mi> </msup> <mrow> <mo>(</mo> <mi>e</mi> <mo>)</mo> </mrow> <mo>=</mo> <msub> <mi>π</mi> <mi>a</mi> </msub> <mrow> <mo>(</mo> <mi>e</mi> <mo>)</mo> </mrow> </mrow> </semantics></math> based on the event log in <a href="#applsci-11-05730-t001" class="html-table">Table 1</a>.</p> Full article ">Figure 4
<p>An Example of the simplified models with different conditions.</p> Full article ">Figure 5
<p>The architecture of the implemented tool.</p> Full article ">Figure 6
<p>The interactive viewer in the implemented tool.</p> Full article ">Figure 7
<p>Visualization details of the model.</p> Full article ">Figure 8
<p>An example of the model that applied the arc color-coding.</p> Full article ">Figure 9
<p>The integrated model from the collected manufacturing log.</p> Full article ">Figure 10
<p>The simplified model from the collected manufacturing log with the statistical analysis.</p> Full article ">
19 pages, 9541 KiB  
Article
Selection of Vertiports Using K-Means Algorithm and Noise Analyses for Urban Air Mobility (UAM) in the Seoul Metropolitan Area
by Junyoung Jeong, Minjun So and Ho-Yon Hwang
Appl. Sci. 2021, 11(12), 5729; https://doi.org/10.3390/app11125729 - 21 Jun 2021
Cited by 23 | Viewed by 5849
Abstract
In this study, a combination of well-established algorithms and real-world data was implemented for the forward-looking problem of future vertiport network design in a large metropolitan city. The locations of vertiports were selected to operate urban air mobility (UAM) in the Seoul metropolitan [...] Read more.
In this study, a combination of well-established algorithms and real-world data was implemented for the forward-looking problem of future vertiport network design in a large metropolitan city. The locations of vertiports were selected to operate urban air mobility (UAM) in the Seoul metropolitan area based on the population of commuters, and a noise priority route was created to minimize the number of people affected by noise using Aviation Environmental Design Tool (AEDT) software. Demand data were analyzed using survey data from the commuting population and were marked on a map using MATLAB. To cluster the data, the K-means algorithm function built in MATLAB was used to select the center of the cluster as the location of the vertiports, and the accuracy and reliability of the clustering were evaluated using silhouette techniques. The locations of the selected vertiports were also identified using satellite image maps to ensure that the location of the selected vertiports were suitable for the actual vertiport location, and if the location was not appropriate, final vertiports were selected through the repositioning process. A helicopter model was then used to analyze the amount of noise reduction achieved by the noise priority route, which is the route between the selected K-UAM vertiports compared to the shortest distance route. As a result, it was shown that the noise priority route that minimized the amount of noise exposure was more efficient than the business priority routes. Full article
(This article belongs to the Special Issue Urban Air Mobility/Advanced Air Mobility Using eVTOL Aircraft)
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<p>Commuter data expressed in MATLAB for each district.</p> Full article ">Figure 2
<p>Administrative districts represented by squares.</p> Full article ">Figure 3
<p>(<b>a</b>) Result of clustering when the number of vertiports is 40; (<b>b</b>) result of clustering when the number of vertiports is 100.</p> Full article ">Figure 4
<p>(<b>a</b>) Evaluation result of the silhouette technique when the number of vertiports is 40; (<b>b</b>) evaluation result of the silhouette technique when the number of vertiports is 100.</p> Full article ">Figure 5
<p>Seoul metropolitan area green belt.</p> Full article ">Figure 6
<p>Location of repositioned vertiports.</p> Full article ">Figure 7
<p>Location of repositioned vertiports.</p> Full article ">Figure 8
<p>Examples of final 100 vertiports.</p> Full article ">Figure 9
<p>(<b>a</b>) Result of clustering when the number of vertiports is 10; (<b>b</b>) result of clustering when the number of vertiports is 40.</p> Full article ">Figure 10
<p>(<b>a</b>) Virtual noise width of eVTOL passing through the actual city; (<b>b</b>) virtual noise width of eVTOL passing through a virtual city modeled in an ideal space.</p> Full article ">Figure 11
<p>K-UAM mission profile.</p> Full article ">Figure 12
<p>Two methods of route generation from Gimpo airport to COEX.</p> Full article ">Figure 13
<p>Each city and district modeled in the ideal space.</p> Full article ">Figure 14
<p>Noise maps for two different scenarios.</p> Full article ">Figure 15
<p>Noise analysis results for two different scenarios in the modeled area.</p> Full article ">
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