[go: up one dir, main page]

Next Issue
Volume 11, February-1
Previous Issue
Volume 11, January-1
You seem to have javascript disabled. Please note that many of the page functionalities won't work as expected without javascript enabled.
 
 
applsci-logo

Journal Browser

Journal Browser

Appl. Sci., Volume 11, Issue 2 (January-2 2021) – 425 articles

Cover Story (view full-size image): Low-frequency modes at terahertz (THz) frequencies have been appointed as critical for protein conformational processes. Modal analysis is applied to the hen egg-white lysozyme structure to obtain the characteristic dynamic features of the protein. All-atom and coarse-grained representations, based on the residues' center of mass, are taken and the results are compared with the experimental B-factors, allowing the assessment of the regional flexibility, conventionally associated with the biological function. Further, we have an in-depth look at the frequency spectrum distribution and the limitations of this technique, especially concerning the cutoff radius. View this paper.
  • Issues are regarded as officially published after their release is announced to the table of contents alert mailing list.
  • You may sign up for e-mail alerts to receive table of contents of newly released issues.
  • PDF is the official format for papers published in both, html and pdf forms. To view the papers in pdf format, click on the "PDF Full-text" link, and use the free Adobe Reader to open them.
Order results
Result details
Section
Select all
Export citation of selected articles as:
16 pages, 846 KiB  
Article
The Moderating Role of IT in Process of Shaping Organizational Performance by Dynamic Capabilities of Controlling
by Agnieszka Bieńkowska and Katarzyna Tworek
Appl. Sci. 2021, 11(2), 889; https://doi.org/10.3390/app11020889 - 19 Jan 2021
Cited by 8 | Viewed by 2765
Abstract
IT solutions have a significant role in supporting controlling processes, as well as in shaping the performance of organization as a whole. The aim of this article is to examine the impact of controlling dynamic capabilities on organizational performance through quality of controlling [...] Read more.
IT solutions have a significant role in supporting controlling processes, as well as in shaping the performance of organization as a whole. The aim of this article is to examine the impact of controlling dynamic capabilities on organizational performance through quality of controlling and verify the role of IT support for the obtainment of benefits for the organization as a whole. The empirical verification of hypotheses was done on the sample of 229 organizations functioning in Poland. The presented results of empirical research allowed for the construction of a model demonstrating the impact of dynamic capabilities of controlling on organizational performance through quality of controlling. Next, it was concluded that IT dynamic capabilities as well as IT reliability moderates the influence of dynamic capabilities of controlling on organizational performance. Methods of statistical description and estimation were used for the empirical research (based on the questionnaire as a main tool of data gathering), esp. multiple linear regression analysis with mediator and moderators was performed using SPSS Macro Process. Full article
(This article belongs to the Section Electrical, Electronics and Communications Engineering)
Show Figures

Figure 1

Figure 1
<p>Mediation model of DC of controlling influence on organizational performance; <span class="html-italic">source: own work.</span></p>
Full article ">Figure 2
<p>Moderators of model of DC of controlling influence on organizational performance; <span class="html-italic">source: own work.</span></p>
Full article ">Figure 3
<p>Empirical research results. Source: own work.</p>
Full article ">
17 pages, 14513 KiB  
Article
Effect of Dry–Wet Cycle Periods on Properties of Concrete under Sulfate Attack
by Jin-Jun Guo, Peng-Qiang Liu, Cun-Liang Wu and Kun Wang
Appl. Sci. 2021, 11(2), 888; https://doi.org/10.3390/app11020888 - 19 Jan 2021
Cited by 13 | Viewed by 3068
Abstract
Dry–wet cycle conditions have significant effects on the corrosion of concrete under sulfate attack. However, previous studies have only applied them as a method for accelerating sulfate attack and not systematically studied them as an object. In order to explore the impact of [...] Read more.
Dry–wet cycle conditions have significant effects on the corrosion of concrete under sulfate attack. However, previous studies have only applied them as a method for accelerating sulfate attack and not systematically studied them as an object. In order to explore the impact of sulfate attack with different dry–wet cycle periods on concrete, in this study, four dry–wet cycle periods (3, 7, 14, and 21 days) were selected. The flexure strength, relative dynamic modulus, and mass were tested, and the microstructures of the eroded specimens were also analyzed. The intensity and depth of sulfate erosion were influenced by the wet–dry cycle period. The results show that the deterioration of concrete first increased and then decreased with an extension of the dry–wet cycle period. Microstructural analysis indicated that, with an increase in the dry–wet cycle period, the corrosion depth of sulfate attack increased. Moreover, the erosion products such as ettringite and gypsum were greatly increased, in agreement with the macroscopic variations. However, excessively prolonging the dry–wet periods does not significantly further the deterioration of concrete’s performance. Therefore, considering the strength and depth of corrosion caused by sulfate attack, it would be appropriate to employ dry–wet cycle periods of 7–14 days under natural dry conditions in studies on concrete. Full article
(This article belongs to the Special Issue Advances in Building Materials and Concrete)
Show Figures

Figure 1

Figure 1
<p>XRD spectrum for fly ash.</p>
Full article ">Figure 2
<p>Particle size distribution of fly ash and cement.</p>
Full article ">Figure 3
<p>Wetting and drying process. (<b>a</b>) Wetting process; (<b>b</b>) drying process.</p>
Full article ">Figure 4
<p>Flexural strength test for concrete. (<b>a</b>) Test schematic; (<b>b</b>) Test process.</p>
Full article ">Figure 5
<p>Visual inspection of concrete with dry–wet cycles. (<b>a</b>) Before sulfate erosion; (<b>b</b>) after sulfate erosion.</p>
Full article ">Figure 6
<p>Crystallized sodium sulfate.</p>
Full article ">Figure 7
<p>Variation of relative flexural strength among different dry-wet cycle periods.</p>
Full article ">Figure 8
<p>Variation of relative dynamic elastic modulus among different dry-wet cycle periods.</p>
Full article ">Figure 9
<p>Variation of mass change among different dry-wet cycle periods.</p>
Full article ">Figure 10
<p>The microstructure before and after the sulfate dry–wet cycle for 84 days. (<b>a</b>) Before sulfate dry–wet cycle; (<b>b</b>) T3.</p>
Full article ">Figure 11
<p>The microstructures of the specimens after sulfate dry–wet cycles for 210 days. (<b>a</b>) T3; (<b>b</b>) T7.</p>
Full article ">Figure 12
<p>The microstructures of the specimens after sulfate dry–wet cycles for 210 days. (<b>a</b>) T3; (<b>b</b>) T21.</p>
Full article ">
17 pages, 4295 KiB  
Article
An Unbalance Optimization Method for a Multi-Stage Rotor Based on an Assembly Error Propagation Model
by Yue Chen, Jiwen Cui and Xun Sun
Appl. Sci. 2021, 11(2), 887; https://doi.org/10.3390/app11020887 - 19 Jan 2021
Cited by 9 | Viewed by 2570
Abstract
For the assembly of a multi-stage rotor, such as an aero-engine or gas turbine, the parts need to be assembled optimally to avoid excessive unbalance. We propose a method to optimize the unbalance of a multi-stage rotor during assembly. First, we developed an [...] Read more.
For the assembly of a multi-stage rotor, such as an aero-engine or gas turbine, the parts need to be assembled optimally to avoid excessive unbalance. We propose a method to optimize the unbalance of a multi-stage rotor during assembly. First, we developed an assembly error propagation model for a multi-stage rotor. The alignment process and distribution of the screw holes of the adjacent rotors was considered for the first time. Secondly, we propose a new assembly datum for unbalance optimization to ensure consistency with the actual conditions of a dynamic balance test. Finally, the unbalance optimization of a multi-stage rotor was achieved using a genetic algorithm, and the corresponding optimal assembly orientations of rotors at different stages were also identified. The results of the simulations showed that the assembly error propagation model had high accuracy and that the genetic optimization process had good convergence. The effect of unbalance optimization was also proven with experiments. Full article
(This article belongs to the Special Issue Mechanical Tolerance Analysis in the Era of Industry 4.0)
Show Figures

Figure 1

Figure 1
<p>The initial state of a 3-D two-stage simulation rotor before assembly.</p>
Full article ">Figure 2
<p>The assembly processes of a 3-D two-stage simulation rotor.</p>
Full article ">Figure 3
<p>Assembly datum for unbalance optimization of four-stage rotor.</p>
Full article ">Figure 4
<p>The center coordinates of the top mounting surface of the assembled three-stage rotor were measured using software.</p>
Full article ">Figure 5
<p>The convergence progress of the genetic algorithm (GA)-based unbalance optimization. (<b>a</b>) Taking the minimum unbalance as the optimization objective. (<b>b</b>) Taking the maximum unbalance as the optimization objective.</p>
Full article ">Figure 6
<p>Selection of the optimal orientations between two optional orientations.</p>
Full article ">Figure 7
<p>The section view of the four-stage rotor.</p>
Full article ">Figure 8
<p>Measurement of the geometric parameters of a high-pressure compressor (HPC). (<b>a</b>) Measured scene. (<b>b</b>) Schematic diagram.</p>
Full article ">Figure 9
<p>The setting of the initial unbalance of the four-stage rotor.</p>
Full article ">Figure 10
<p>Measurement of the unbalance of the four-stage rotor.</p>
Full article ">
19 pages, 698 KiB  
Article
Static Response of Double-Layered Pipes via a Perturbation Approach
by Daniele Zulli, Arnaldo Casalotti and Angelo Luongo
Appl. Sci. 2021, 11(2), 886; https://doi.org/10.3390/app11020886 - 19 Jan 2021
Cited by 4 | Viewed by 1673
Abstract
A double-layered pipe under the effect of static transverse loads is considered here. The mechanical model, taken from the literature and constituted by a nonlinear beam-like structure, is constituted by an underlying Timoshenko beam, enriched with further kinematic descriptors which account for local [...] Read more.
A double-layered pipe under the effect of static transverse loads is considered here. The mechanical model, taken from the literature and constituted by a nonlinear beam-like structure, is constituted by an underlying Timoshenko beam, enriched with further kinematic descriptors which account for local effects, namely, ovalization of the cross-section, warping and possible relative sliding of the layers under bending. The nonlinear equilibrium equations are addressed via a perturbation method, with the aim of obtaining a closed-form solution. The perturbation scheme, tailored for the specific load conditions, requires different scaling of the variables and proceeds up to the fourth order. For two load cases, namely, distributed and tip forces, the solution is compared to that obtained via a pure numeric approach and the finite element method. Full article
(This article belongs to the Special Issue Homogenization Methods in Materials and Structures)
Show Figures

Figure 1

Figure 1
<p>The double-layered beam with an annular cross-section: (<b>a</b>) complete view; (<b>b</b>) details of the cross-section.</p>
Full article ">Figure 2
<p>Initial configuration of the beam.</p>
Full article ">Figure 3
<p>Physical meaning of the distortion variables: (<b>a</b>) assumed trial function for ovalization and amplitude <math display="inline"><semantics> <msub> <mi>a</mi> <mi>p</mi> </msub> </semantics></math>; (<b>b</b>) assumed trial function for warping and amplitude <math display="inline"><semantics> <msub> <mi>a</mi> <mi>w</mi> </msub> </semantics></math>; (<b>c</b>) assumed trial function for longitudinal sliding of the layers under opposite bending and amplitude <math display="inline"><semantics> <msub> <mi>a</mi> <mi>g</mi> </msub> </semantics></math>.</p>
Full article ">Figure 4
<p>Response in the case of the uniformly distributed vertical load: (<b>a</b>) longitudinal displacement <math display="inline"><semantics> <mrow> <mi>u</mi> <mo>/</mo> <mi>l</mi> <mspace width="0.166667em"/> <mo>(</mo> <mo>×</mo> <msup> <mn>10</mn> <mrow> <mo>−</mo> <mn>3</mn> </mrow> </msup> <mo>)</mo> </mrow> </semantics></math>; (<b>b</b>) <math display="inline"><semantics> <mrow> <mi>v</mi> <mo>/</mo> <mi>l</mi> </mrow> </semantics></math>; (<b>c</b>) transversal displacement <math display="inline"><semantics> <mrow> <mi>ϑ</mi> <mspace width="0.166667em"/> <mo>(</mo> <mi>rad</mi> <mo>)</mo> </mrow> </semantics></math>; (<b>d</b>) amplitude of ovalization <math display="inline"><semantics> <mrow> <msub> <mi>a</mi> <mi>p</mi> </msub> <mo>/</mo> <mi>R</mi> </mrow> </semantics></math>; (<b>e</b>) amplitude of relative sliding <math display="inline"><semantics> <mrow> <msub> <mi>a</mi> <mi>g</mi> </msub> <mo>/</mo> <mi>R</mi> </mrow> </semantics></math>; (<b>f</b>) amplitude of warping <math display="inline"><semantics> <mrow> <msub> <mi>a</mi> <mi>w</mi> </msub> <mo>/</mo> <mi>R</mi> </mrow> </semantics></math>. Blue lines: perturbation solution; light blue lines: finite difference method; gray lines: FEM.</p>
Full article ">Figure 5
<p>Distributed force: evolution of the tip displacements while increasing the amplitude of the load (<math display="inline"><semantics> <mrow> <mover accent="true"> <mi>p</mi> <mo>˜</mo> </mover> <mo>:</mo> <mo>=</mo> <mfrac> <mrow> <msub> <mi>p</mi> <mi>v</mi> </msub> <mi>l</mi> </mrow> <mrow> <mi>π</mi> <mi>R</mi> <mo>(</mo> <msub> <mi>G</mi> <mi>e</mi> </msub> <mi>h</mi> <mi>e</mi> <mo>+</mo> <msub> <mi>G</mi> <mi>i</mi> </msub> <mi>h</mi> <mi>i</mi> <mo>)</mo> </mrow> </mfrac> </mrow> </semantics></math>). Black dashed line: load condition of <a href="#applsci-11-00886-f004" class="html-fig">Figure 4</a>; blue line: perturbation solution; light blue line: finite difference method; gray line: FEM.</p>
Full article ">Figure 6
<p>Response in the case of the uniformly distributed vertical load: (<b>a</b>) longitudinal displacement <math display="inline"><semantics> <mrow> <mi>u</mi> <mo>/</mo> <mi>l</mi> </mrow> </semantics></math>; (<b>b</b>) <math display="inline"><semantics> <mrow> <mi>v</mi> <mo>/</mo> <mi>l</mi> </mrow> </semantics></math>; (<b>c</b>) transversal displacement <math display="inline"><semantics> <mrow> <mi>ϑ</mi> <mspace width="0.166667em"/> <mo>(</mo> <mi>rad</mi> <mo>)</mo> </mrow> </semantics></math>; (<b>d</b>) amplitude of ovalization <math display="inline"><semantics> <mrow> <msub> <mi>a</mi> <mi>p</mi> </msub> <mo>/</mo> <mi>R</mi> </mrow> </semantics></math>; (<b>e</b>) amplitude of relative sliding <math display="inline"><semantics> <mrow> <msub> <mi>a</mi> <mi>g</mi> </msub> <mo>/</mo> <mi>R</mi> </mrow> </semantics></math>; (<b>f</b>) amplitude of warping <math display="inline"><semantics> <mrow> <msub> <mi>a</mi> <mi>w</mi> </msub> <mo>/</mo> <mi>R</mi> </mrow> </semantics></math>. Blue lines: perturbation solution; light blue lines: finite difference method; gray lines: FEM.</p>
Full article ">Figure 7
<p>Tip force: evolution of the tip displacements while the increasing of the amplitude of the load (<math display="inline"><semantics> <mrow> <mover accent="true"> <mi>P</mi> <mo>˜</mo> </mover> <mo>:</mo> <mo>=</mo> <mfrac> <msub> <mi>P</mi> <mi>v</mi> </msub> <mrow> <mi>π</mi> <mi>R</mi> <mo>(</mo> <msub> <mi>G</mi> <mi>e</mi> </msub> <msub> <mi>h</mi> <mi>e</mi> </msub> <mo>+</mo> <msub> <mi>G</mi> <mi>i</mi> </msub> <msub> <mi>h</mi> <mi>i</mi> </msub> <mo>)</mo> </mrow> </mfrac> </mrow> </semantics></math>). Black dashed line: load condition of <a href="#applsci-11-00886-f006" class="html-fig">Figure 6</a>; blue line: perturbation solution; light blue line: finite difference method; gray line: FEM.</p>
Full article ">Figure A1
<p>FE model: (<b>a</b>) sketch of the tubular structure; (<b>b</b>) representation of the adopted mesh.</p>
Full article ">
22 pages, 7636 KiB  
Article
Energy Management Optimization of a Dual Motor Lithium Ion Capacitors-Based Hybrid Super Sport Car
by Alessandro Franceschi, Nicolò Cavina, Riccardo Parenti, Maurizio Reggiani and Enrico Corti
Appl. Sci. 2021, 11(2), 885; https://doi.org/10.3390/app11020885 - 19 Jan 2021
Cited by 2 | Viewed by 2741
Abstract
Nowadays, hybrid electric vehicles represent one of the main solutions for the reduction of greenhouse gases in the automotive sector. Alongside the reduction of CO2, hybrid electric vehicles serve as a strong alternative on drivability and performance to conventional internal combustion [...] Read more.
Nowadays, hybrid electric vehicles represent one of the main solutions for the reduction of greenhouse gases in the automotive sector. Alongside the reduction of CO2, hybrid electric vehicles serve as a strong alternative on drivability and performance to conventional internal combustion engine-based vehicles. Vehicles exist with various missions; super sport cars usually aim to reach peak performance and to guarantee a great driving experience to the driver, but great attention must also be paid to fuel consumption. According to the vehicle mission, hybrid electric vehicles can differ in the powertrain configuration and the choice of the energy storage system. Manufacturers have recently started to work on Lithium-Ion Capacitors (LiC) -based hybrid vehicles. This paper discusses the usage of a control-oriented vehicle and powertrain model to analyze the performance of a dual motor LiC-based hybrid V12 vehicle by Automobili Lamborghini. P3–P4 and P2–P4 parallel hybrid configurations have been selected and compared since they allow to fully exploit the potential of the LiC storage system characterized by high power. The validated model has been used to develop control strategies aimed at fuel economy and CO2 reduction, and in particular, both Rule Based Strategies (RBS) and Equivalent Consumption Minimization Strategies (ECMS) are presented in the paper. A critical comparison between the various powertrain configurations is carried out, keeping into account the peculiarities of the LiC technology and evaluating the performance of the different control approaches. Full article
(This article belongs to the Special Issue Optimal Design and Control of Thermal Hybrid Powertrains)
Show Figures

Figure 1

Figure 1
<p>Longitudinal dynamics model structure. The input is the target speed coming from the chosen cycle. The loop is closed thanks to the comparison with the actual speed.</p>
Full article ">Figure 2
<p>Powertrain scheme.</p>
Full article ">Figure 3
<p>Vehicle scheme and forces representation [<a href="#B1-applsci-11-00885" class="html-bibr">1</a>].</p>
Full article ">Figure 4
<p>Lithium-Ion Capacitor scheme.</p>
Full article ">Figure 5
<p>Lithium-Ion Capacitor model.</p>
Full article ">Figure 6
<p>Power input normalized to its maximum value.</p>
Full article ">Figure 7
<p>Voltage profiles.</p>
Full article ">Figure 8
<p>Simulink variant subsystem model for the hybrid control strategy choice.</p>
Full article ">Figure 9
<p>Rule Based Strategies (RBS) control functions’ activation range.</p>
Full article ">Figure 10
<p>Equivalent Consumption Minimization Strategies (ECMS) Scheme.</p>
Full article ">Figure 11
<p>Speed-dependent state of charge (SoC) target profile for a WLTP 3b cycle.</p>
Full article ">Figure 12
<p>WLTP 3b cycle.</p>
Full article ">Figure 13
<p>SoC and Torque profiles for P3–P4 RBS.</p>
Full article ">Figure 14
<p>SoC and Torque profiles for P2–P4 RBS.</p>
Full article ">Figure 15
<p>EM RPM comparison.</p>
Full article ">Figure 16
<p>ECMS simulation for P3–P4 with an SoC target equal to 50%.</p>
Full article ">Figure 17
<p>ECMS simulation for P3–P4 with an SoC target depending on speed.</p>
Full article ">Figure 18
<p>ECMS simulation for P2–P4 with an SoC target equal to 50%.</p>
Full article ">Figure 19
<p>ECMS simulation for P2–P4 with an SoC target dependent on speed.</p>
Full article ">Figure 20
<p>RBS simulation with half displacement for P2–P4.</p>
Full article ">Figure 21
<p>ECMS simulation with half displacement for P3–P4 with a target SoC dependent on speed.</p>
Full article ">
10 pages, 602 KiB  
Review
Wheat Germ Agglutinin—From Toxicity to Biomedical Applications
by Gabrielė Balčiūnaitė-Murzienė and Mindaugas Dzikaras
Appl. Sci. 2021, 11(2), 884; https://doi.org/10.3390/app11020884 - 19 Jan 2021
Cited by 16 | Viewed by 5572
Abstract
Wheat germ agglutinin is a hevein class N-Acetylglucosamine–binding protein with specific toxicity and biomedical potential. It is extractable from wheat germ—a low-value byproduct of the wheat industry—using well–established extraction methods based on salt precipitation and affinity chromatography. Due to its N-Acetylglucosamine [...] Read more.
Wheat germ agglutinin is a hevein class N-Acetylglucosamine–binding protein with specific toxicity and biomedical potential. It is extractable from wheat germ—a low-value byproduct of the wheat industry—using well–established extraction methods based on salt precipitation and affinity chromatography. Due to its N-Acetylglucosamine affinity, wheat germ agglutinin exhibits antifungal properties as well as cytotoxic properties. Its anticancer properties have been demonstrated for various cancer cells, and toxicity mechanisms are well described. Wheat germ agglutinin has been demonstrated as a viable solution for various biomedical and therapeutic applications, such as chemotherapy, targeted drug delivery, antibiotic-resistant bacteria monitoring and elimination. This is performed mostly in conjunction with nanoparticles, liposomes, and other carrier mechanisms via surface functionalization. Combined with abundant wheat byproduct sources, wheat germ agglutinin has the potential to improve the biomedical field considerably. Full article
Show Figures

Figure 1

Figure 1
<p>Dimeric wheat germ agglutinin 3 (WGA3) structure by [<a href="#B24-applsci-11-00884" class="html-bibr">24</a>]. Red, orange, yellow, and brown colors represent the subunits A, B, C, and D of the first protein, respectively. Blue, light blue, pink, and purple represent the subunits A, B, C, and D of the second protein, respectively. The sugar-binding site is located at the interface of both WGA monomers.</p>
Full article ">
14 pages, 13597 KiB  
Article
Detection of Movement Intention for Operating Methods of Serious Games
by Jung-Hyun Park, Ho-Sang Moon, Hyunggun Kim and Sung-Taek Chung
Appl. Sci. 2021, 11(2), 883; https://doi.org/10.3390/app11020883 - 19 Jan 2021
Cited by 3 | Viewed by 2552
Abstract
In many post-stroke cases, patients show dysfunctions in movement, cognition, sense, and language, depending on the damaged area of the brain. Active and repetitive physical rehabilitation centered on the stroke-affected side is essential for effective and rapid neurological recovery of upper extremity dysfunction [...] Read more.
In many post-stroke cases, patients show dysfunctions in movement, cognition, sense, and language, depending on the damaged area of the brain. Active and repetitive physical rehabilitation centered on the stroke-affected side is essential for effective and rapid neurological recovery of upper extremity dysfunction due to hemiplegia. A symmetric upper extremity trainer is utilized to assist the patient body, depending upon the degree of hemiplegia. In this study, we developed a novel balance handle as a symmetric upper extremity trainer capable of extension, flexion, pronation, and supination of the upper extremity. We collected the surface electromyogram (sEMG) signal data while the subjects were playing a serious game and recorded the electroencephalogram (EEG) signal data while the subjects were performing basic movements with the balance handle, to analyze the effectiveness of the device as an assistive tool for rehabilitation. The triceps brachii were activated during the extension movements, whereas the biceps brachii and deltoid muscles were activated during the flexion movements. With the balance handle, the peak event-related desynchronization (ERD) values were relatively lower while showing higher peak event-related synchronization (ERS) values compared to other types of operating methods, such as hand gripping and gamepad operation. Movement intention of tilting the balance handle for the α and β waves was clearly distinguished from the other tasks. These data demonstrated the potential of various applications using the developed proof-of-concept upper extremity trainer to bring out an excellent rehabilitative effect not only through muscle growth but also via identification of large movement intentions inducing brain activation exercise. Full article
(This article belongs to the Special Issue Biotechnology and Sports Engineering)
Show Figures

Figure 1

Figure 1
<p>The components of the balance handle.</p>
Full article ">Figure 2
<p>Serious game contents for surface electromyogram (sEMG) measurement: (<b>a</b>) forward–backward inclination; (<b>b</b>) left–right inclination.</p>
Full article ">Figure 3
<p>Sequence of the experimental task: (<b>a</b>) inter-stimulus interval; (<b>b</b>) grip task; (<b>c</b>) gamepad task; and (<b>d</b>) balance handle task.</p>
Full article ">Figure 4
<p>Positions of the electrodes attached to collect sEMG signals.</p>
Full article ">Figure 5
<p>The 10–20 international system of EEG electrode placement.</p>
Full article ">Figure 6
<p>Signal processing procedures for sEMG data: (<b>a</b>) raw sEMG; (<b>b</b>) RMS for the raw data; and (<b>c</b>) down-sampling and moving averaging.</p>
Full article ">Figure 7
<p>Flowchart of the signal processing for the event-related desynchronization (ERD)/event-related synchronization (ERS) calculation.</p>
Full article ">Figure 8
<p>The sEMG signal data corresponding to the tilting angles of the balance handle: (<b>a</b>) extension and flexion; (<b>b</b>) pronation and supination.</p>
Full article ">Figure 9
<p>RA measurements with the hand gripping, gamepad operation, and balance handle operation.</p>
Full article ">Figure 10
<p>Box and whisker plots of the ERD/ERS peak values: (<b>a</b>) α wave (8–12 Hz); (<b>b</b>) β wave (12–20 Hz).</p>
Full article ">
12 pages, 3860 KiB  
Article
Fabrication and Optical Characterization of Polymeric Aspherical Microlens Array Using Hot Embossing Technology
by Yanlong Li, Kangsen Li and Feng Gong
Appl. Sci. 2021, 11(2), 882; https://doi.org/10.3390/app11020882 - 19 Jan 2021
Cited by 13 | Viewed by 4044
Abstract
Hot embossing has been widely used in fabricating microlens arrays because of its low cost, high efficiency, and high quality. The process parameters such as molding temperature, molding pressure, and holding temperature affect the microlens array’s replication quality. This work selected the stainless [...] Read more.
Hot embossing has been widely used in fabricating microlens arrays because of its low cost, high efficiency, and high quality. The process parameters such as molding temperature, molding pressure, and holding temperature affect the microlens array’s replication quality. This work selected the stainless steel S136H tool steel as the mold material to process an aspheric microlens array structure through ultra-precision milling. Polymethyl methacrylate (PMMA) microlens arrays with different surface replication were prepared by controlling the molding temperature, molding pressure, and holding temperature. By analyzing the surface quality, contour replication, and optical imaging of hot-embossed samples, the optimal molding temperature of PMMA for optimal replication of aspheric lens arrays was determined as 130 °C. Besides, the internal elastic recovery of PMMA affected the dimensional accuracy and optical performance of the lens. The results showed that, at the molding pressure of 400 N and the holding temperature of 60 °C, the surface defects were eliminated, and the aspheric lens array had perfect replication with a profile deviation of only 4 μm. The aspheric microlens array with good quality was eventually achieved by these optimal process parameters, which provides a foundation for producing aspheric microlens arrays in a low-cost and high-efficiency way. Full article
(This article belongs to the Collection Optical Design and Engineering)
Show Figures

Figure 1

Figure 1
<p>Aspheric microlens array mold design and processing. (<b>a</b>) Design of aspheric microlens array with basic geometric parameters, (<b>b</b>) mold processing, and (<b>c</b>) characterization of microlens array mold.</p>
Full article ">Figure 2
<p>Process diagram of hot press forming and time history of force and temperature.</p>
Full article ">Figure 3
<p>(<b>a</b>) Schematic diagram of molding machine system and (<b>b</b>) SZU’s PGMM30.</p>
Full article ">Figure 4
<p>(<b>a</b>) Aspheric microlens array image at a molding temperature of 100 °C, (<b>b</b>) the comparison of aspheric microlens profile and mold profile at a molding temperature of 100 °C, (<b>c</b>) aspheric microlens array image when the temperature is 130 °C, (<b>d</b>) the comparison of the aspheric microlens profile and mold profile when the molding temperature is 110 °C/130 °C, and (<b>e</b>) the surface of the aspheric microlens array with bubbles when the molding temperature is 150 °C.</p>
Full article ">Figure 5
<p>(<b>a</b>) Comparison of aspheric lens profile and mold profile when the holding temperature is 90 °C; (<b>b</b>) comparison of aspheric lens profile and mold profile when the holding temperature is 70 °C and 50 °C; (<b>c</b>) the surface and imaging performance of aspheric microlens at holding temperatures of 90 °C, 70 °C, and 50 °C; and (<b>d</b>) the heights and surface morphologies of the aspheric lens under different molding pressures.</p>
Full article ">Figure 6
<p>(<b>a</b>) 3 × 3 MLA characterization of the mold, (<b>b</b>) 3 × 3 MLA characterization of the sample, (<b>c</b>) the original measurement surface, and (<b>d</b>) the profile and error of the two radial cross-section surfaces.</p>
Full article ">Figure 7
<p>Simulation of optical imaging. (<b>a</b>) Three-dimensional schematic diagram of optical simulation, (<b>b</b>) simulated light focusing points on the receiver, (<b>c</b>) planar ray tracing simulation, and (<b>d</b>) light intensity distribution of the receiver x section.</p>
Full article ">Figure 8
<p>(<b>a</b>) The schematic diagram of optical imaging platform, (<b>b</b>) focus imaging and intensity data captured by CCD camera of PMMA microlens array, and (<b>c</b>) the capital letter “A” focused on the aspheric lens array.</p>
Full article ">
14 pages, 3572 KiB  
Article
A Theoretical Method for Designing Thin Wobble Motor Using an Electromagnetic Force and an Electropermanent Magnet for Application in Portable Electric Equipment
by Sang Yong Park, Buchun Song and Yoon Su Baek
Appl. Sci. 2021, 11(2), 881; https://doi.org/10.3390/app11020881 - 19 Jan 2021
Cited by 2 | Viewed by 2585
Abstract
The thin wobble motors that are required to hold rating shafts employ an electropermanent magnet. This turns the holding force on and off by applying a momentary electrical pulse. To design the magnet devices without the need for finite element analyses, a theoretical [...] Read more.
The thin wobble motors that are required to hold rating shafts employ an electropermanent magnet. This turns the holding force on and off by applying a momentary electrical pulse. To design the magnet devices without the need for finite element analyses, a theoretical force model is necessary for predicting the attractive force. In this paper, first, a force model is derived by estimating the permeance around the air gap. A magnetic circuit is constructed, employing a relatively simple method to build the model in clouding leakage flux. Thus, the basic structure and driving principle are also presented. Next, an analytical force model is constructed on the basis of distribution parameter analysis between the stator and the rotating shaft. The design of the electromagnet core and the control method are presented. Finally, a prototype model of the motor that is 30 mm in diameter and 7 mm in thick is fabricated. The two models are verified by comparing the results of FEM with the results of the experiments. They can properly predict the attractive force, so the thin wobble motor with holding force can be applied in portable electric equipment. Full article
(This article belongs to the Special Issue Modelling and Control of Mechatronic and Robotic Systems, Volume II)
Show Figures

Figure 1

Figure 1
<p>Driving principle of a wobble motor: (<b>a</b>) Schematic of a wobble motor; (<b>b</b>) Driving principle.</p>
Full article ">Figure 2
<p>Basic principle driving an electropermanent magnet: (<b>a</b>) In the no current state, the two magnets are oppositely polarized; (<b>b</b>) In the switching current state, the two magnetic magnets are polarized in the same direction.</p>
Full article ">Figure 3
<p>Schematic of the switchable eletropermanent magnet construction.</p>
Full article ">Figure 4
<p>Paths model for leakage flux: (<b>a</b>) Paths for the leaked flux; (<b>b</b>) Mean length of flux path.</p>
Full article ">Figure 5
<p>Analysis model consisting of an electropermanent magnet: (<b>a</b>) Flux leakage of the electropermanent magnet; (<b>b</b>) Magnetic circuit.</p>
Full article ">Figure 6
<p>Permeance of flux paths through the air gap: (<b>a</b>) Permeance of parallel to end of the core; (<b>b</b>) Simple-shaped volumes of permeance.</p>
Full article ">Figure 7
<p>Geometric model for theoretical analysis.</p>
Full article ">Figure 8
<p>Simplified geometry.</p>
Full article ">Figure 9
<p>Schematic of the thin wobble motor with an Electropermanent magnet.</p>
Full article ">Figure 10
<p>Shape of the core: (<b>a</b>) Parameters for optimization of the core; (<b>b</b>) optimized core and the magnetic flux density distribution.</p>
Full article ">Figure 11
<p>Basic principle driving a proposed electropermanent manent magnet: (<b>a</b>) Flux path when the magnetization direction of magnets is in the opposite direction; (<b>b</b>) Flux path through air gap between iron and shaft.</p>
Full article ">Figure 12
<p>The driving method of the motor and total system of driving motor.</p>
Full article ">Figure 13
<p>Pictures of a thin wobble motor with EPM. (<b>a</b>) Parts a thin wobble motor; (<b>b</b>) Fabricated EPM device; (<b>c</b>) Core with the coil wound.</p>
Full article ">Figure 14
<p>Experiment results, and comparisons of the force vs. air, calculated using the mantic circuit with and without leakage flux.</p>
Full article ">
14 pages, 2826 KiB  
Article
Valence and Arousal-Infused Bi-Directional LSTM for Sentiment Analysis of Government Social Media Management
by Yu-Ya Cheng, Yan-Ming Chen, Wen-Chao Yeh and Yung-Chun Chang
Appl. Sci. 2021, 11(2), 880; https://doi.org/10.3390/app11020880 - 19 Jan 2021
Cited by 11 | Viewed by 3652
Abstract
Private entrepreneurs and government organizations widely adopt Facebook fan pages as an online social platform to communicate with the public. Posting on the platform to attract people’s comments and shares is an effective way to increase public engagement. Moreover, the comment functions allow [...] Read more.
Private entrepreneurs and government organizations widely adopt Facebook fan pages as an online social platform to communicate with the public. Posting on the platform to attract people’s comments and shares is an effective way to increase public engagement. Moreover, the comment functions allow users who have read the posts to express their thoughts. Hence, it also enables us to understand the users’ emotional feelings regarding that post by analyzing the comments. The goal of this study is to investigate the public image of organizations by exploring the content on fan pages. In order to efficiently analyze the enormous amount of public opinion data generated from social media, we propose a Bi-directional Long Short-Term Memory (BiLSTM) that can model detailed sentiment information hidden in those words. It first forecasts the sentiment information in terms of Valence and Arousal (VA) values of the smallest unit in a text, and later fuses this into a deep learning model to further analyze the sentiment of the whole text. Experiments show that our model can achieve state-of-the-art performance in terms of predicting the VA values of words. Additionally, combining VA with a BiLSTM model results in a boost of the performance for social media text sentiment analysis. Our method can assist governments or other organizations to improve their effectiveness in social media operations through the understanding of public opinions on related issues. Full article
(This article belongs to the Special Issue Sentiment Analysis for Social Media Ⅱ)
Show Figures

Figure 1

Figure 1
<p>Examples of a post and its comments found on the Facebook fan page of the Ministry of Health and Welfare.</p>
Full article ">Figure 2
<p>Scatter plot of VA values of words in the Chinese Valence-Arousal Words (CVAW) 3.0 dataset.</p>
Full article ">Figure 3
<p>Overall workflow of the research.</p>
Full article ">Figure 4
<p>The sentimental Valence-Arousal prediction model based on deep neural networks and comprehensive semantic features.</p>
Full article ">Figure 5
<p>The sentiment prediction model based on deep neural network and comprehensive features.</p>
Full article ">Figure 6
<p>The word cloud generated from all the comments on the Ministry of Health and Welfare fan page regarding the infection that occurred during a navy training mission.</p>
Full article ">
15 pages, 4529 KiB  
Article
Reveal of Internal, Early-Load Interfacial Debonding on Cement Textile-Reinforced Sandwich Insulated Panels
by Eleni Tsangouri, Hasan Ismail, Matthias De Munck, Dimitrios G. Aggelis and Tine Tysmans
Appl. Sci. 2021, 11(2), 879; https://doi.org/10.3390/app11020879 - 19 Jan 2021
Cited by 9 | Viewed by 2764
Abstract
Internal interfacial debonding (IID) phenomena on sandwich façade insulated panels are detected and tracked by acoustic emission (AE). The panels are made of a thin and lightweight cementitious composite skin. In the lab, the panels are tested under incremental bending simulating service loads [...] Read more.
Internal interfacial debonding (IID) phenomena on sandwich façade insulated panels are detected and tracked by acoustic emission (AE). The panels are made of a thin and lightweight cementitious composite skin. In the lab, the panels are tested under incremental bending simulating service loads (i.e., wind). Local (up to 150 mm wide) skin-core detachments are reported in the early loading stage (at 5% of ultimate load) and are extensively investigated in this study, since IID can detrimentally affect the long-term durability of the structural element. A sudden rise in the AE hits rate and a shift in the wave features (i.e., absolute energy, amplitude, rise time) trends indicate the debonding onset. AE source localization, validated by digital image correlation (DIC) principal strains and out-of-plane full-field displacement mapping, proves that early debonding occurs instantly and leads to the onset of cracks in the cementitious skin. At higher load levels, cracking is accompanied by local debonding phenomena, as proven by RA value increases and average frequency drops, a result that extends the state-of-the-art in the fracture assessment of concrete structures (Rilem Technical Committee 212-ACD). Point (LVDT) and full-field (AE/DIC) measurements highlight the need for a continuous and full-field monitoring methodology in order to pinpoint the debonded zones, with the DIC technique accurately reporting surface phenomena while AE offers in-volume damage tracking. Full article
Show Figures

Figure 1

Figure 1
<p>Sandwich-insulated panel: (<b>a</b>) specimen geometry and detail of the textiles’ geometry; (<b>b</b>) a wet steel beam is passed along the top of the mold to control the panel’s thickness; (<b>c</b>) the core layer is covered with a plastic sheet after casting; (<b>d</b>) loading support and setup; (<b>e</b>) the panel under load. Sand and cement bags are symmetrically distributed at the top skin of the panel. (<b>f</b>) Drawing of the bottom view: the Digital Image Correlation area of interest is marked with a speckle pattern, the AE sensors’ position is marked in red, and the Linear Variable Differential Transformer (LVDT) sensors are marked in black.</p>
Full article ">Figure 2
<p>AE hits analysis: load and absolute energy plots in time for (<b>a</b>) Reference (REF) and (<b>b</b>) Internal Interfacial Debonding (IID) panels; (<b>c</b>) cumulative plot of the hit population for both test cases. Incremental loading step of 0.5 kN/m<sup>2</sup>.</p>
Full article ">Figure 3
<p>Rise time (RT) and Initiation frequency (IF) scatter plots (data in transparent font) for a representative time period (marked in <a href="#applsci-11-00879-f002" class="html-fig">Figure 2</a>a,b) of a jump in AE energy. Averaging (each 250 points) trend line is plotted for (<b>a</b>) REF and (<b>b</b>) IID panels.</p>
Full article ">Figure 4
<p>Principal E1 (%) strain maps at each step (in kN/m<sup>2</sup>) of incremental load for REF and IID panels.</p>
Full article ">Figure 5
<p>Out-of-plane displacement (mm) (<b>a</b>) at each step of incremental load for REF and IID panels, (<b>b</b>) at the point of maximum displacement, (<b>c</b>) along a diagonal line at 1.5 kN/m<sup>2</sup>, (<b>d</b>) at the middle of the panel, (<b>e</b>) along a diagonal line at 5 kN/m<sup>2</sup>.</p>
Full article ">Figure 6
<p>RA value (μs/V)-AF (kHz) average values at each loading step for (<b>a</b>) REF and (<b>b</b>) IID.</p>
Full article ">Figure 7
<p>AE events projected at the bottom plane of the TRC skin. In black are the events detected at 3.5 kN/m<sup>2</sup>, and in red in <a href="#applsci-11-00879-t001" class="html-table">Table 1</a>. A strain map at 4 kN/m<sup>2</sup> is projected as a plot background.</p>
Full article ">
15 pages, 6221 KiB  
Article
Experimental Research on Foil Vibrations in a Gas Foil Bearing Carried Out Using an Ultra-High-Speed Camera
by Łukasz Breńkacz, Paweł Bagiński and Grzegorz Żywica
Appl. Sci. 2021, 11(2), 878; https://doi.org/10.3390/app11020878 - 19 Jan 2021
Cited by 11 | Viewed by 2432
Abstract
The foil bearing consists of parts made of very thin, properly shaped foils. Usually, it is very difficult or even impossible to measure the vibrations of these elements during the bearing operation using traditional sensors. Therefore, the authors of this article have proposed [...] Read more.
The foil bearing consists of parts made of very thin, properly shaped foils. Usually, it is very difficult or even impossible to measure the vibrations of these elements during the bearing operation using traditional sensors. Therefore, the authors of this article have proposed an entirely new approach to this issue. This article discusses the analysis of vibrations of the structural supporting layer of a gas foil bearing at high rotational speeds. Instead of using a traditional method to measure the bearing journal movement, the measurement was performed using an ultra-high-speed digital camera. This type of measurement was used for the first time to analyse foil bearing displacement. It turned out that doing so can give a far more vibrant picture of what is happening in gas foil bearings during their operation. The article includes an analysis of foil vibrations. This phenomenon has already been analysed numerically, and this is the first time it has been analysed experimentally. The registered motion of the foils can be compared with the results obtained from numerical models, thus allowing their further development. One such comparison is shown in this article. Full article
(This article belongs to the Section Mechanical Engineering)
Show Figures

Figure 1

Figure 1
<p>Test rig with a foil bearing and a computer-controlled camera.</p>
Full article ">Figure 2
<p>Scheme of the measurement setup.</p>
Full article ">Figure 3
<p>Scheme showing how the foil bearing is mounted on the shaft.</p>
Full article ">Figure 4
<p>Vision Research’s v2511 ultrahigh-speed camera (<b>left</b>). Extension tubes that enable achieving higher macro magnification (<b>right</b>).</p>
Full article ">Figure 5
<p>Point used to analyse the displacement (on the bump foil).</p>
Full article ">Figure 6
<p>Displacement of the foil at a rotational speed of 24,000 rpm. One bump is not manufactured perfectly.</p>
Full article ">Figure 7
<p>Displacement of the foil at a rotational speed of 24,000 rpm.</p>
Full article ">Figure 8
<p>Point on the surface of the sleeve, which was used to perform a displacement analysis when a small excitation force was applied to the bearing (indicated by green arrow).</p>
Full article ">Figure 9
<p>Displacement of the bearing to which a small excitation force was applied.</p>
Full article ">Figure 10
<p>Maximum deflection of the foils caused by an impulse excitation (<b>left</b>). Stable operation of the bearing (<b>right</b>).</p>
Full article ">Figure 11
<p>Displacement of the bearing to which a high excitation force was applied.</p>
Full article ">Figure 12
<p>Picture recorded using a high-speed camera (<b>left</b>). The changes between the two extreme journal positions are marked in red (<b>right</b>).</p>
Full article ">Figure 13
<p>Model of foil bearing with unequal bumps.</p>
Full article ">Figure 14
<p>Changes of foil displacements.</p>
Full article ">
16 pages, 5178 KiB  
Article
Design and Calibration of a Tri-Directional Contact Force Measurement System
by Rizwan Ahmed, Christian Maria Firrone and Stefano Zucca
Appl. Sci. 2021, 11(2), 877; https://doi.org/10.3390/app11020877 - 19 Jan 2021
Cited by 2 | Viewed by 3273
Abstract
In low pressure turbine stages, adjacent blades are coupled to each other at their tip by covers, called shrouds. Three-dimensional periodic contact forces at shrouds strongly affect the blade vibration level as energy is dissipated by friction. To validate contact models developed for [...] Read more.
In low pressure turbine stages, adjacent blades are coupled to each other at their tip by covers, called shrouds. Three-dimensional periodic contact forces at shrouds strongly affect the blade vibration level as energy is dissipated by friction. To validate contact models developed for the prediction of nonlinear forced response of shrouded blades, direct contact force measurement during dynamic tests is mandatory. In case of shrouded blades, the existing unidirectional and bi-directional contact force measurement methods need to be improved and extended to a tri-directional measurement of shroud contact forces for a comprehensive and more reliable validation of the shroud contact models. This demands an accurate and robust measurement solution that is compatible with the nature and orientation of the contact forces at blade shrouds. This study presents a cost effective and adaptable tri-directional force measurement system to measure static and dynamic contact forces simultaneously in three directions at blade shrouds during forced response tests. The system is based on three orthogonal force transducers connected to a reference block that will eventually be put in contact with the blade shroud in the test rig. A calibration process is outlined to define a decoupling matrix and its subsequent validation is demonstrated in order to evaluate the effectiveness of the measurement system to measure the actual contact forces acting on the contact. Full article
(This article belongs to the Special Issue Experimental Mechanics, Instrumentation and Metrology)
Show Figures

Figure 1

Figure 1
<p>Shrouded blades (<b>left</b>) and the shroud contact surfaces (<b>right</b>).</p>
Full article ">Figure 2
<p>Blade shrouds in contact with force measurement system in the proposed test rig.</p>
Full article ">Figure 3
<p>(<b>a</b>) Force sensors in tripod configuration, (<b>b</b>) Locknut Collar (above) and Necked collar (below).</p>
Full article ">Figure 4
<p>Calibration plot for system with locknut collars.</p>
Full article ">Figure 5
<p>Calibration plot for system with necked collars.</p>
Full article ">Figure 6
<p>Simultaneous application of static loads in three orthogonal directions.</p>
Full article ">Figure 7
<p>Decoupling method applied to locknut collar links (Load case 1: Circles; Load case 2: Triangles).</p>
Full article ">Figure 8
<p>Decoupling method applied to necked collar links (Load case 1: Circles; Load case 2: Triangles).</p>
Full article ">Figure 9
<p>Modified experimental setup for dynamic loading with chamfered block and shaker.</p>
Full article ">Figure 10
<p>Frequency Response Function (FRF) plot of the tri-directional force measurement calibration setup.</p>
Full article ">Figure 11
<p>Decoupling method applied in dynamic loading experiment at (<b>a</b>) 100 Hz and (<b>b</b>) 200 Hz.</p>
Full article ">
10 pages, 883 KiB  
Article
Anthropometric Profiles in Table Tennis Players: Analysis of Sex, Age, and Ranking
by Francisco Pradas, Ana de la Torre, Luis Carrasco, Diego Muñoz, Javier Courel-Ibáñez and José Antonio González-Jurado
Appl. Sci. 2021, 11(2), 876; https://doi.org/10.3390/app11020876 - 19 Jan 2021
Cited by 12 | Viewed by 4351
Abstract
Table tennis has recently evolved towards a more spectacular sport increasing match-play demands and the intensity and speed of actions by regulations and equipment modification. Since these changes can alter the body composition and performance, this study aimed to analyze the differences in [...] Read more.
Table tennis has recently evolved towards a more spectacular sport increasing match-play demands and the intensity and speed of actions by regulations and equipment modification. Since these changes can alter the body composition and performance, this study aimed to analyze the differences in anthropometric attributes of 495 table tennis players (288 men, 207 women) according to sex, age, and ranking. Players were classified according to sex, age categories (Senior, Under-18, Under-15, Under 13, and Under 11), and ranking position. Anthropometry measurements included eight skinfolds’ thicknesses (biceps brachii, triceps, subscapular, iliac crest, supraspinal, abdominal, thigh, and medial calf), four girths (biceps brachii relaxed and contracted, thigh, and calf), and three breadths (biepicondylar femur, biepicondylar humerus, and bistiloyd wrist) to determine fat mass, lean mass, bone, cross sectional area (CSA) for arm, leg, and thigh, and somatotype. Results revealed that table tennis players presented differences in body mass composition, anthropometry, and somatotype according to sex and age category and ranking. It seems confirmed that regular table tennis practice during the childhood is associated with a healthy body composition status, that appears to be maintained across older ages if keeping the practice. Senior table tennis players showed a fat mass <20% and lean mass ~45% in men and ~37% in women. A new contribution is that higher lean mass in the upper limbs was associated with higher ranking position (i.e., better performance), endomorphic somatotypes were negative related to performance, and ectomorphic profiles seems more effective, which suggest the potential influence of morphologic changes in table tennis competition performance. Full article
Show Figures

Figure 1

Figure 1
<p>Somatotype distribution of high-level table tennis players according to sex and age categories. Clear markers indicate individual data for each player. Dark markers represent the mean values for a given category. Error bars are standard deviations.</p>
Full article ">
22 pages, 1968 KiB  
Article
Perceived Benefits of Energy Efficiency in the Spanish Residential Market and Their Relation to Sociodemographic and Living Conditions
by Eva Crespo Sánchez, Silvia Spairani Berrio, Belén Onecha Perez and Carlos Marmolejo-Duarte
Appl. Sci. 2021, 11(2), 875; https://doi.org/10.3390/app11020875 - 19 Jan 2021
Cited by 10 | Viewed by 2666
Abstract
Within the Energy Performance of Buildings Directive information symmetry regarding financial and environmental benefits, coming from real estate performance, is a key element in the promotion of efficient buildings. However, the link between energy efficiency and its perceived co-benefits is far from perfect [...] Read more.
Within the Energy Performance of Buildings Directive information symmetry regarding financial and environmental benefits, coming from real estate performance, is a key element in the promotion of efficient buildings. However, the link between energy efficiency and its perceived co-benefits is far from perfect in EU countries with a short trajectory in the promotion of such residential attributes, endangering the efficacy of information-symmetry policies. Using a large survey applied to sellers, buyers, lessors and tenants this paper explores, in Spain, the perceived co-benefits in terms of energy savings and thermal comfort of efficient homes and whether such perception correlates to current living conditions, housing tenure and sociodemographic profile of respondents. Results suggest that in general such co-benefits are present in the mind of the main agents of the housing market. However, their perception is far from being homogeneous, it is clearer in the case of households whose current home is poorly insulated or inadequately serviced in terms of thermal active systems. Sociodemographic conditions also play a role in co-benefits perceptions: Elder, wealthier and landlords, irrespective of whether they act as sellers, buyers or lessors, do perceive to a larger extent the co-benefits of efficient homes. Such findings signal clear paths for the improvement of energy and housing policy. Full article
Show Figures

Figure 1

Figure 1
<p>Energy performance’s benefits and co-benefits classification. Source: Self elaboration from the study “Impact of co-benefits on the assessment of energy related building renovation with a nearly-zero energy target” [<a href="#B15-applsci-11-00875" class="html-bibr">15</a>].</p>
Full article ">Figure 2
<p>Perceived co-benefits or energy performance before and after the retrofit program. Source: Own elaboration using Stephenson et al. [<a href="#B30-applsci-11-00875" class="html-bibr">30</a>] data.</p>
Full article ">Figure 3
<p>Descriptive statistics. Source: Self elaboration.</p>
Full article ">Figure 4
<p>Perceived benefits according to market segments and offer/demand sides. Source: Self elaboration.</p>
Full article ">Figure 5
<p>Perceived co-benefits according to respondents’ sociodemographic profile. Source: Self elaboration.</p>
Full article ">Figure 6
<p>Retrofit requirements and priorities according to respondents’ sociodemographic profile. Source: Self elaboration.</p>
Full article ">Figure 7
<p>Regression model to identify the factors influencing the perception of EE benefits. Source: Self elaboration.</p>
Full article ">
23 pages, 3067 KiB  
Article
Evaluation of Bioactive and Physicochemical Properties of White and Black Garlic (Allium sativum L.) from Conventional and Organic Cultivation
by Katarzyna Najman, Anna Sadowska and Ewelina Hallmann
Appl. Sci. 2021, 11(2), 874; https://doi.org/10.3390/app11020874 - 19 Jan 2021
Cited by 22 | Viewed by 4846
Abstract
The aim of this study was to evaluate the bioactive and physicochemical properties of white and black garlic (Allium sativum L.) from conventional and organic cultivation. Both white conventional (G) and organic (EG) garlic were processed during 45 days heat treatment at [...] Read more.
The aim of this study was to evaluate the bioactive and physicochemical properties of white and black garlic (Allium sativum L.) from conventional and organic cultivation. Both white conventional (G) and organic (EG) garlic were processed during 45 days heat treatment at 70 °C temperature and 80% relative humidity. In black garlic (BG) samples the content of soluble solids, total reducing sugars, total polyphenol as well as antioxidant activity significantly (p < 0.05) increased (by about 33.5%, 60.5%, 118.4%, 125.8%, respectively), while a pH significantly (p < 0.05) decreased (by about 41.1%) as compared to white garlic samples. The study showed significant differences between colour of white and black garlic, both in the L*a*b* and RGB colour space, especially in the case of the L* parameter, indicating that the colour of garlic changed from white to dark brown or black during the thermal processing. All organic garlic samples had improved bioactive ingredients and antioxidant activity compared to conventional garlic for both fresh (unprocessed) and heat-treated black garlic. The production of black garlic, especially organic (EBG), allows one to obtain a product with higher amount of bioactive compounds, which can be widely used in the design of health-promoting functional food. Full article
(This article belongs to the Special Issue Organic Food)
Show Figures

Figure 1

Figure 1
<p>Changes in the appearance of fresh conventional (G) and organic (EG) garlic (bulbs and cloves) during heat treatment (45 days, 70 °C, 80% humidity). G—fresh conventional garlic; EG—fresh organic garlic; BG—conventional black garlic; EBG—organic black garlic.</p>
Full article ">Figure 2
<p>Detailed colour analysis of white garlic from conventional cultivation (G) using the instrumental method (“electronic eye”).</p>
Full article ">Figure 3
<p>Detailed colour analysis of white garlic from organic cultivation (EG) using the instrumental method (“electronic eye”).</p>
Full article ">Figure 4
<p>Detailed colour analysis of black garlic from conventional cultivation (BG) using the instrumental method (“electronic eye”).</p>
Full article ">Figure 5
<p>Detailed colour analysis of black garlic from organic cultivation (EBG) using the instrumental method (“electronic eye”).</p>
Full article ">
16 pages, 857 KiB  
Article
Effects of Phase Shift Errors in Recurrence Plot for Rotating Machinery Fault Diagnosis
by Ignacio Torres-Contreras, Juan Carlos Jáuregui-Correa, Carlos Santiago López-Cajún and Salvador Echeverría-Villagómez
Appl. Sci. 2021, 11(2), 873; https://doi.org/10.3390/app11020873 - 19 Jan 2021
Cited by 7 | Viewed by 2421
Abstract
For fault diagnosis and predictive maintenance of rotating machinery, the phase errors generated by the integration processing of a vibration signal are an essential investigation subject. Phase errors affect the solution of mechanical systems with multiple vibration sources and also the information transmitted [...] Read more.
For fault diagnosis and predictive maintenance of rotating machinery, the phase errors generated by the integration processing of a vibration signal are an essential investigation subject. Phase errors affect the solution of mechanical systems with multiple vibration sources and also the information transmitted through the vibration that is used for fault diagnosis. This work proposes the use of phase plane, recurrence plot (RP), and cross recurrence plot (CRP) to evaluate phase shift error effects on the solution of multiple asynchronous and simple periodic functions, and on the smoothing of a Gaussian peak with white noise. Noisy peaks were smoothed twice with the triangular method and with a different number of points. The analysis of the asynchronous periodic functions and the smoothing indicated that a small phase shift changes the phase plane and the RP pattern. These changes can affect not only the accuracy of machinery fault diagnosis but also prediction for the application of timely maintenance actions. Full article
(This article belongs to the Special Issue Advances in Theoretical and Applied Mechanics)
Show Figures

Figure 1

Figure 1
<p>(<b>a</b>) Evolution of the state variables; (<b>b</b>) phase plane of the linear harmonic for the function: <math display="inline"><semantics> <mrow> <mi>x</mi> <mo>=</mo> <mo form="prefix">sin</mo> <mo>(</mo> <mn>2</mn> <mi>t</mi> <mo>+</mo> <mi>ϕ</mi> <mo>)</mo> </mrow> </semantics></math>.</p>
Full article ">Figure 2
<p>Proposed flow chart to analyze the phase shift effects on functions and smoothing.</p>
Full article ">Figure 3
<p>Photo of one application of the proposed research.</p>
Full article ">Figure 4
<p>Displacement, velocity and acceleration for the function: <math display="inline"><semantics> <mrow> <mi>x</mi> <mo>=</mo> <mo form="prefix">sin</mo> <mo>(</mo> <mn>2</mn> <mi>t</mi> <mo>+</mo> <mi>ϕ</mi> <mo>)</mo> </mrow> </semantics></math>.</p>
Full article ">Figure 5
<p>Evolution of the state variables and phase plane for <math display="inline"><semantics> <mrow> <mi>x</mi> <mo>=</mo> <mo form="prefix">sin</mo> <mo>(</mo> <mn>2</mn> <mi>t</mi> <mo>+</mo> <mi>ϕ</mi> <mo>)</mo> </mrow> </semantics></math>, <math display="inline"><semantics> <mrow> <mover accent="true"> <mi>x</mi> <mo>˙</mo> </mover> <mo>=</mo> <mn>2</mn> <mo form="prefix">cos</mo> <mrow> <mo>(</mo> <mn>2</mn> <mi>t</mi> <mo>+</mo> <mi>ϕ</mi> <mo>)</mo> </mrow> </mrow> </semantics></math> and <math display="inline"><semantics> <mrow> <mi>ϕ</mi> <mo>=</mo> <mo>[</mo> <mn>0</mn> <mo>,</mo> <mi>π</mi> <mo>/</mo> <mn>8</mn> <mo>]</mo> </mrow> </semantics></math>.</p>
Full article ">Figure 6
<p>Recurrence plot for <math display="inline"><semantics> <mrow> <mi>x</mi> <mo>=</mo> <mo form="prefix">sin</mo> <mo>(</mo> <mn>2</mn> <mi>t</mi> <mo>+</mo> <mi>ϕ</mi> <mo>)</mo> </mrow> </semantics></math>: (<b>a</b>) without phase shift (<math display="inline"><semantics> <mrow> <mi>ϕ</mi> <mo>=</mo> <mn>0</mn> </mrow> </semantics></math>); (<b>b</b>) with phase shift (<math display="inline"><semantics> <mrow> <mi>ϕ</mi> <mo>=</mo> <mi>π</mi> <mo>/</mo> <mn>8</mn> </mrow> </semantics></math>).</p>
Full article ">Figure 7
<p>Evolution of the state variables and phase plane for the multiple asynchronous function of Equation (<a href="#FD12-applsci-11-00873" class="html-disp-formula">12</a>): (<b>a</b>) without phase shift (<math display="inline"><semantics> <mrow> <mi>ϕ</mi> <mo>=</mo> <mn>0</mn> </mrow> </semantics></math>); (<b>b</b>) with phase shift (<math display="inline"><semantics> <mrow> <mi>ϕ</mi> <mo>=</mo> <mi>π</mi> <mo>/</mo> <mn>8</mn> </mrow> </semantics></math>).</p>
Full article ">Figure 8
<p>Recurrence plot for the multiple asynchronous function of Equation (<a href="#FD12-applsci-11-00873" class="html-disp-formula">12</a>): (<b>a</b>) without phase shift (<math display="inline"><semantics> <mrow> <mi>ϕ</mi> <mo>=</mo> <mn>0</mn> </mrow> </semantics></math>); (<b>b</b>) with phase shift (<math display="inline"><semantics> <mrow> <mi>ϕ</mi> <mo>=</mo> <mi>π</mi> <mo>/</mo> <mn>8</mn> </mrow> </semantics></math>).</p>
Full article ">Figure 9
<p>The Gaussian peak for the analysis: (<b>a</b>) with white noise; (<b>b</b>) without noise.</p>
Full article ">Figure 10
<p>The phase shifts generated by the smoothing process: (<b>a</b>) signals after smoothing; (<b>b</b>) normalized and filtered peaks.</p>
Full article ">Figure 11
<p>Recurrence plot for each peak analyzed with a threshold distance of <math display="inline"><semantics> <mrow> <mi>ϵ</mi> <mo>=</mo> <mn>0.10</mn> </mrow> </semantics></math>. (<b>a</b>) Gaussian peak; (<b>b</b>) smoothed peak for a width of 50 points; (<b>c</b>) smoothed peak for a width of 30 points.</p>
Full article ">Figure 12
<p>RQA quantification for the smoothed Gaussian peaks with different sample points.</p>
Full article ">
11 pages, 1115 KiB  
Article
Retrospective Analysis of the Effect of Three-Dimensional Preformed Titanium Mesh on Peri-Implant Non-Contained Horizontal Defects in 100 Consecutive Cases
by In-Oh Choi, Ji-Su Oh, Sang-Joun Yu, Byung-Ock Kim and Won-Pyo Lee
Appl. Sci. 2021, 11(2), 872; https://doi.org/10.3390/app11020872 - 19 Jan 2021
Cited by 5 | Viewed by 2606
Abstract
This study aimed to clinically and radiographically evaluate the results of guided bone regeneration (GBR) using three-dimensional preformed titanium mesh (3-D-PFTM) for non-contained horizontal defects in 100 consecutive cases. This study involved 100 patients (129 implants) with peri-implant non-contained horizontal defects. The patients [...] Read more.
This study aimed to clinically and radiographically evaluate the results of guided bone regeneration (GBR) using three-dimensional preformed titanium mesh (3-D-PFTM) for non-contained horizontal defects in 100 consecutive cases. This study involved 100 patients (129 implants) with peri-implant non-contained horizontal defects. The patients were divided into three groups: 3-D-PFTM alone (Group 1), 3-D-PFTM plus cross-linked collagen membrane (Group 2), and 3-D-PFTM plus non-cross-linked collagen membrane (Group 3). Each implant was evaluated radiographically using CBCT at baseline and 6 months postoperatively. At the platform level, the mean horizontal hard tissue gain of all the sites was 3.1 ± 1.3 mm at 6 months postoperatively. The mean rate of mesh exposure was 11.8% in Group 1, 4.2% in Group 2, and 5.0% in Group 3. The mean hard tissue gain rate was 71.0 ± 23.0% in group 1, 84.2 ± 21.5% in group 2, and 84.0 ± 22.9% in group 3. Groups 2 and 3 showed significantly higher hard tissue gain rates than group 1. However, there was no significant difference between the rates in groups 2 and 3. Within the limitations of this study, 3-D-PFTM should be considered as a valuable option for GBR for peri-implant non-contained horizontal defects. The use of an additional resorbable collagen membrane provides additional advantages. Full article
(This article belongs to the Special Issue Applied Sciences in Dentistry)
Show Figures

Figure 1

Figure 1
<p>Surgical procedure. (<b>A</b>) Flap elevation, (<b>B</b>,<b>C</b>) Implantation, (<b>D</b>) Bone grafts and 3-D preformed titanium mesh application, (<b>E</b>) Collagen membrane application, (<b>F</b>) Suturing, and (<b>G</b>–<b>I</b>) Secondary implant surgery.</p>
Full article ">Figure 2
<p>Method of radiographic analysis. (<b>A</b>) A line parallel to the long major axis of the implant is drawn, as well as a perpendicular line extending buccally at the level of the implant platform. (<b>B</b>) Table 3. D-PFTM, three-dimensional preformed titanium mesh; BA, bone augmentation immediately after surgery; HG, hard tissue gain after 6 months of healing.</p>
Full article ">Figure 3
<p>Comparison of the hard tissue gain rates (HGR) of the groups. There was a statistically significant difference between the rates of Groups 1 and 2, as well as Groups 1 and 3. HGR, the percentage of HG compared with BA (HG/BA); BA, bone augmentation immediately after surgery; HG, hard tissue gain after 6 months of healing; Group 1, only three-dimensional preformed titanium mesh (3-D-PFTM) used; Group 2, 3-D-PFTM + cross-linked collagen membrane used; Group 3, 3-D-PFTM + non-cross-linked collagen membrane used. * Statistically significant difference (<span class="html-italic">p</span> &lt; 0.05; Kruskal–Wallis test).</p>
Full article ">
21 pages, 646 KiB  
Review
The Use of Microalgae and Cyanobacteria in the Improvement of Agricultural Practices: A Review on Their Biofertilising, Biostimulating and Biopesticide Roles
by Ana L. Gonçalves
Appl. Sci. 2021, 11(2), 871; https://doi.org/10.3390/app11020871 - 19 Jan 2021
Cited by 119 | Viewed by 9840
Abstract
The increase in worldwide population observed in the last decades has contributed to an increased demand for food supplies, which can only be attained through an improvement in agricultural productivities. Moreover, agricultural practices should become more sustainable, as the use of chemically-based fertilisers, [...] Read more.
The increase in worldwide population observed in the last decades has contributed to an increased demand for food supplies, which can only be attained through an improvement in agricultural productivities. Moreover, agricultural practices should become more sustainable, as the use of chemically-based fertilisers, pesticides and growth stimulants can pose serious environmental problems and lead to the scarcity of finite resources, such as phosphorus and potassium, thus increasing the fertilisers’ costs. One possible alternative for the development of a more sustainable and highly effective agriculture is the use of biologically-based compounds with known activity in crops’ nutrition, protection and growth stimulation. Among these products, microalgal and cyanobacterial biomass (or their extracts) are gaining particular attention, due to their undeniable potential as a source of essential nutrients and metabolites with different bioactivities, which can significantly improve crops’ yields. This manuscript highlights the potential of microalgae and cyanobacteria in the improvement of agricultural practices, presenting: (i) how these photosynthetic microorganisms interact with higher plants; (ii) the main bioactive compounds that can be isolated from microalgae and cyanobacteria; and (iii) how microalgae and cyanobacteria can influence plants’ growth at different levels (nutrition, protection and growth stimulation). Full article
Show Figures

Figure 1

Figure 1
<p>Categorisation of the main activities attributed to algal/cyanobacterial biomass and extracts in crops’ production.</p>
Full article ">
30 pages, 602 KiB  
Article
Human-Centered Artificial Intelligence for Designing Accessible Cultural Heritage
by Galena Pisoni, Natalia Díaz-Rodríguez, Hannie Gijlers and Linda Tonolli
Appl. Sci. 2021, 11(2), 870; https://doi.org/10.3390/app11020870 - 19 Jan 2021
Cited by 42 | Viewed by 12159
Abstract
This paper reviews the literature concerning technology used for creating and delivering accessible museum and cultural heritage sites experiences. It highlights the importance of the delivery suited for everyone from different areas of expertise, namely interaction design, pedagogical and participatory design, and it [...] Read more.
This paper reviews the literature concerning technology used for creating and delivering accessible museum and cultural heritage sites experiences. It highlights the importance of the delivery suited for everyone from different areas of expertise, namely interaction design, pedagogical and participatory design, and it presents how recent and future artificial intelligence (AI) developments can be used for this aim, i.e.,improving and widening online and in situ accessibility. From the literature review analysis, we articulate a conceptual framework that incorporates key elements that constitute museum and cultural heritage online experiences and how these elements are related to each other. Concrete opportunities for future directions empirical research for accessibility of cultural heritage contents are suggested and further discussed. Full article
Show Figures

Figure 1

Figure 1
<p>Conceptual framework for AI-enabled accessibility of museums and cultural heritage sites. Novel AI components include the concepts of learning progress in curiosity-driven exploration [<a href="#B11-applsci-11-00870" class="html-bibr">11</a>], pedagogical agents [<a href="#B14-applsci-11-00870" class="html-bibr">14</a>], creative AI, natural language explanation generation, accessible CH through explainable AI [<a href="#B93-applsci-11-00870" class="html-bibr">93</a>] and automatic curriculum learning [<a href="#B13-applsci-11-00870" class="html-bibr">13</a>].</p>
Full article ">
20 pages, 499 KiB  
Article
Towards Improved Classification Accuracy on Highly Imbalanced Text Dataset Using Deep Neural Language Models
by Sarang Shaikh, Sher Muhammad Daudpota, Ali Shariq Imran and Zenun Kastrati
Appl. Sci. 2021, 11(2), 869; https://doi.org/10.3390/app11020869 - 19 Jan 2021
Cited by 33 | Viewed by 4989
Abstract
Data imbalance is a frequently occurring problem in classification tasks where the number of samples in one category exceeds the amount in others. Quite often, the minority class data is of great importance representing concepts of interest and is often challenging to obtain [...] Read more.
Data imbalance is a frequently occurring problem in classification tasks where the number of samples in one category exceeds the amount in others. Quite often, the minority class data is of great importance representing concepts of interest and is often challenging to obtain in real-life scenarios and applications. Imagine a customers’ dataset for bank loans-majority of the instances belong to non-defaulter class, only a small number of customers would be labeled as defaulters, however, the performance accuracy is more important on defaulters labels than non-defaulter in such highly imbalance datasets. Lack of enough data samples across all the class labels results in data imbalance causing poor classification performance while training the model. Synthetic data generation and oversampling techniques such as SMOTE, AdaSyn can address this issue for statistical data, yet such methods suffer from overfitting and substantial noise. While such techniques have proved useful for synthetic numerical and image data generation using GANs, the effectiveness of approaches proposed for textual data, which can retain grammatical structure, context, and semantic information, has yet to be evaluated. In this paper, we address this issue by assessing text sequence generation algorithms coupled with grammatical validation on domain-specific highly imbalanced datasets for text classification. We exploit recently proposed GPT-2 and LSTM-based text generation models to introduce balance in highly imbalanced text datasets. The experiments presented in this paper on three highly imbalanced datasets from different domains show that the performance of same deep neural network models improve up to 17% when datasets are balanced using generated text. Full article
(This article belongs to the Special Issue Machine Learning and Natural Language Processing)
Show Figures

Figure 1

Figure 1
<p>Abstract Model of the Proposed System.</p>
Full article ">Figure 2
<p>LSTM Process of Character Level Text Generation.</p>
Full article ">Figure 3
<p>Text Generation for Input Corpus.</p>
Full article ">Figure 4
<p>LSTM Model for Text Generation.</p>
Full article ">Figure 5
<p>Text Generation for MOOCs Lecture Transcriptss using GPT-2 Model.</p>
Full article ">Figure 6
<p>Aspect and Sentiment Classification Model for Course and Teacher [<a href="#B15-applsci-11-00869" class="html-bibr">15</a>].</p>
Full article ">Figure 7
<p>LSTM with Glove Twitter Embedding Model Used in [<a href="#B25-applsci-11-00869" class="html-bibr">25</a>].</p>
Full article ">Figure 8
<p>Classification performance of conventional ML techniques on original and balanced dataset with new generated text.</p>
Full article ">
17 pages, 5175 KiB  
Article
Multiphysics Modeling, Sensitivity Analysis, and Optical Performance Optimization for Optical Laser Head in Additive Manufacturing
by Jiaping Yang, Xiling Yao, Yuxin Cai and Guijun Bi
Appl. Sci. 2021, 11(2), 868; https://doi.org/10.3390/app11020868 - 19 Jan 2021
Cited by 1 | Viewed by 2669
Abstract
Optical laser head is a key component used to shape the laser beam and to deliver higher power laser irradiation onto workpieces for material processing. A focused laser beam size and optical intensity need to be controlled to avoid decreasing beam quality and [...] Read more.
Optical laser head is a key component used to shape the laser beam and to deliver higher power laser irradiation onto workpieces for material processing. A focused laser beam size and optical intensity need to be controlled to avoid decreasing beam quality and loss of intensity in laser material processing. This paper reports the multiphysics modeling of an in-house developed laser head for laser-aided additive manufacturing (LAAM) applications. The design of computer experiments (DoCE) combined with the response surface model was used as an efficient design approach to optimize the optical performance of a high power LAAM head. A coupled structural-thermal-optical-performance (STOP) model was developed to evaluate the influence of thermal effects on the optical performance. A number of experiments with different laser powers, laser beam focal plane positions, and environmental settings were designed and simulated using the STOP model for sensitivity analysis. The response models of the optical performance were constructed using DoCE and regression analysis. Based on the response models, optimal design settings were predicted and validated with the simulations. The results show that the proposed design approach is effective in obtaining optimal solutions for optical performance of the laser head in LAAM. Full article
(This article belongs to the Special Issue Advancements in Laser Based Additive Manufacturing Technologies)
Show Figures

Figure 1

Figure 1
<p>Geometric model of the developed optical laser head.</p>
Full article ">Figure 2
<p>Optical delivery path design.</p>
Full article ">Figure 3
<p>Meshed model of the optical laser head for the structural-thermal-optical-performance (STOP) analysis.</p>
Full article ">Figure 4
<p>The flowchart of the STOP analysis for the optical laser head.</p>
Full article ">Figure 5
<p>Temperature distributions by 1.634 kW in (<b>a</b>) housing structure and (<b>b</b>) lenses, and deformation distributions in (<b>c</b>) housing structure and (<b>d</b>) lenses.</p>
Full article ">Figure 6
<p>(<b>a</b>) Temperature and (<b>b</b>) displacement distributions of the focusing lens irradiated by laser power at 1.634 kW.</p>
Full article ">Figure 7
<p>RMS spot radius (<b>a</b>,<b>c</b>) and optical intensity (<b>b</b>,<b>d</b>) by the STOP analysis (<b>top</b>) and ray tracing simulations (<b>bottom</b>).</p>
Full article ">Figure 8
<p>RMS spot radius <span class="html-italic">R<sub>rms</sub></span> and optical intensity <span class="html-italic">I</span> as the function of focal plane position <span class="html-italic">F<sub>z.</sub></span></p>
Full article ">Figure 9
<p>RMS spot radius <span class="html-italic">R<sub>rms</sub></span> and power density distribution <span class="html-italic">I</span> as the function of laser power <span class="html-italic">P.</span></p>
Full article ">Figure 10
<p>Power density distributions (<b>a</b>) 1.634 kW and (<b>b</b>) 3.364 kW in the focal plane position of <span class="html-italic">F<sub>z</sub></span> = 0.1mm.</p>
Full article ">Figure 11
<p>Response surfaces and contours of optical intensity as the function of any two variables among <span class="html-italic">x</span><sub>1</sub>, <span class="html-italic">x</span><sub>2</sub>, and <span class="html-italic">z</span><sub>1</sub>: (<b>a</b>) <span class="html-italic">I</span> (<span class="html-italic">x</span><sub>1</sub>, <span class="html-italic">x</span><sub>2</sub>), (<b>b</b>) <span class="html-italic">I</span> (<span class="html-italic">x</span><sub>1</sub>, <span class="html-italic">z</span><sub>1</sub>), and (<b>c</b>) <span class="html-italic">I</span> (<span class="html-italic">x</span><sub>2</sub>, <span class="html-italic">z</span><sub>1</sub>).</p>
Full article ">Figure 12
<p>Response surfaces and contours of RMS spot radius <span class="html-italic">R<sub>rms</sub></span> as the function of any two variables among <span class="html-italic">x</span><sub>1</sub>, <span class="html-italic">x</span><sub>2</sub>, and <span class="html-italic">z</span><sub>1</sub>: (<b>a</b>) <span class="html-italic">R<sub>rms</sub></span> (<span class="html-italic">x</span><sub>1</sub>, <span class="html-italic">x</span><sub>2</sub>), (<b>b</b>) <span class="html-italic">R<sub>rms</sub></span> (<span class="html-italic">x</span><sub>1</sub>, <span class="html-italic">z</span><sub>1</sub>), and (<b>c</b>) <span class="html-italic">R<sub>rms</sub></span> (<span class="html-italic">x</span><sub>2</sub>, <span class="html-italic">z</span><sub>1</sub>).</p>
Full article ">Figure 13
<p>(<b>a</b>) Setup of the optical laser head, (<b>b</b>) laser-aided additive manufacturing (LAAM) process, (<b>c</b>) single-tracks deposited with nonoptimal process parameters, and (<b>d</b>) solid layer deposited with optimal process parameters.</p>
Full article ">
19 pages, 14255 KiB  
Article
A Construction Method of Lower Limb Rehabilitation Robot with Remote Control System
by Mingda Miao, Xueshan Gao and Wei Zhu
Appl. Sci. 2021, 11(2), 867; https://doi.org/10.3390/app11020867 - 19 Jan 2021
Cited by 10 | Viewed by 3864
Abstract
In response to the rehabilitation needs of stroke patients who are unable to benefit from conventional rehabilitation due to the COVID-19 epidemic, this paper designs a robot that combines on-site and telerehabilitation. The objective is to assist the patient in walking. We design [...] Read more.
In response to the rehabilitation needs of stroke patients who are unable to benefit from conventional rehabilitation due to the COVID-19 epidemic, this paper designs a robot that combines on-site and telerehabilitation. The objective is to assist the patient in walking. We design the electromechanical system with a gantry mechanism, body-weight support system, information feedback system, and man-machine interactive control system. The proposed rehabilitation robot remote system is based on the client/server (C/S) network framework to realize the remote control of the robot state logic and the transmission of patient training data. Based on the proposed system, doctors can set or adjust the training modes and control the parameters of the robot and guide remote patient rehabilitation training through video communication. The robotic system can further store and manage the rehabilitation data of the patient during training. Experiments show the human-computer interaction system of the lower limb rehabilitation robot has good performance, can accurately recognize the information of human motion posture, and achieve the goal of actively the following motion. Experiments confirm the feasibility of the proposed design, the information management of stroke patients, and the efficiency of rehabilitation training. The proposed system can reduce the workload of the doctors in practical training. Full article
(This article belongs to the Special Issue Tele-Rehabilitation Robotics)
Show Figures

Figure 1

Figure 1
<p>(<b>a</b>) Design of rehabilitation robot structure; (<b>b</b>) system module of rehabilitation robot.</p>
Full article ">Figure 2
<p>Body weight support system of robot.</p>
Full article ">Figure 3
<p>Human-computer interaction system of robot.</p>
Full article ">Figure 4
<p>The framework of telerehabilitation robot interaction system.</p>
Full article ">Figure 5
<p>Control system for rehabilitation robot.</p>
Full article ">Figure 6
<p>Hardware system framework of the rehabilitation robot.</p>
Full article ">Figure 7
<p>Hardware and sensing systems of the rehabilitation robots.</p>
Full article ">Figure 8
<p>Operation flowchart for the remote system.</p>
Full article ">Figure 9
<p>Remote control system interface for rehabilitation robot.</p>
Full article ">Figure 10
<p>The rear panel of displacement and tension sensor.</p>
Full article ">Figure 11
<p>(<b>a</b>) The experimental platform of rehabilitation robotic systems; (<b>b</b>) control platform of the doctor-side remote system.</p>
Full article ">Figure 12
<p>Communication success diagram of the rehabilitation robot client computer.</p>
Full article ">Figure 13
<p>(<b>a</b>) Logic 1 state of the robot; (<b>b</b>) logic 2 state of the robot.</p>
Full article ">Figure 14
<p>Remote communication success diagram of the doctor server computer.</p>
Full article ">Figure 15
<p>Dialog interface of basic information.</p>
Full article ">Figure 16
<p>File export diagram of patient data.</p>
Full article ">Figure 17
<p>Video communication acquisition test of the remote system.</p>
Full article ">Figure 18
<p>(<b>a</b>) The experiment of turning and walking; (<b>b</b>) the experiment of straight walking.</p>
Full article ">Figure 19
<p>(<b>a</b>) Force curve of the straight walking; (<b>b</b>) displacement curve of the straight walking.</p>
Full article ">Figure 20
<p>(<b>a</b>) Force curve of in situ left steering; (<b>b</b>) displacement curve of in situ left steering.</p>
Full article ">Figure 21
<p>(<b>a</b>) Force curve of in situ right steering; (<b>b</b>) displacement curve of in situ right steering.</p>
Full article ">Figure 22
<p>(<b>a</b>) Force curve of in situ squat standing; (<b>b</b>) displacement curve of in situ squat standing.</p>
Full article ">
11 pages, 2354 KiB  
Article
Self-Evaporation Dynamics of Quantum Droplets in a 41K-87Rb Mixture
by Chiara Fort and Michele Modugno
Appl. Sci. 2021, 11(2), 866; https://doi.org/10.3390/app11020866 - 19 Jan 2021
Cited by 18 | Viewed by 2565
Abstract
We theoretically investigate the self-evaporation dynamics of quantum droplets in a 41K-87Rb mixture, in free-space. The dynamical formation of the droplet and the effects related to the presence of three-body losses are analyzed by means of numerical simulations. We identify [...] Read more.
We theoretically investigate the self-evaporation dynamics of quantum droplets in a 41K-87Rb mixture, in free-space. The dynamical formation of the droplet and the effects related to the presence of three-body losses are analyzed by means of numerical simulations. We identify a regime of parameters allowing for the observation of the droplet self-evaporation in a feasible experimental setup. Full article
(This article belongs to the Special Issue Quantum Degenerate Atomic Mixtures)
Show Figures

Figure 1

Figure 1
<p>Heat map of <math display="inline"><semantics> <msup> <mrow> <mo>(</mo> <mover accent="true"> <mi>N</mi> <mo>˜</mo> </mover> <mo>−</mo> <msub> <mover accent="true"> <mi>N</mi> <mo>˜</mo> </mover> <mi>c</mi> </msub> <mo>)</mo> </mrow> <mrow> <mn>1</mn> <mo>/</mo> <mn>4</mn> </mrow> </msup> </semantics></math> as a function of <math display="inline"><semantics> <msub> <mi>a</mi> <mn>12</mn> </msub> </semantics></math> and <math display="inline"><semantics> <msub> <mi>N</mi> <mn>2</mn> </msub> </semantics></math>, with <math display="inline"><semantics> <mrow> <msub> <mover accent="true"> <mi>N</mi> <mo>˜</mo> </mover> <mi>c</mi> </msub> <mo>=</mo> <mn>18.65</mn> </mrow> </semantics></math> being the critical value for the existence of a droplet [<a href="#B1-applsci-11-00866" class="html-bibr">1</a>]. The dotted-dashed lines, corresponding to <math display="inline"><semantics> <mrow> <mover accent="true"> <mi>N</mi> <mo>˜</mo> </mover> <mo>=</mo> <mn>933.7</mn> </mrow> </semantics></math>, <math display="inline"><semantics> <mrow> <mn>94.2</mn> </mrow> </semantics></math>, <math display="inline"><semantics> <mrow> <mn>18.65</mn> </mrow> </semantics></math> (from left to right), represent the boundaries between the different regimes (see text). The vertical red dashed-dotted line at <math display="inline"><semantics> <mrow> <msub> <mi>a</mi> <mn>12</mn> </msub> <mo>=</mo> <mo>−</mo> <mn>73.6</mn> </mrow> </semantics></math> corresponds to the onset of the MF collapse. The two circles at <math display="inline"><semantics> <mrow> <msub> <mi>a</mi> <mn>12</mn> </msub> <mo>=</mo> <mo>−</mo> <mn>82</mn> <msub> <mi>a</mi> <mn>0</mn> </msub> </mrow> </semantics></math> refer to the parameter configurations considered in <a href="#sec4-applsci-11-00866" class="html-sec">Section 4</a>.</p>
Full article ">Figure 2
<p>Heat map of <math display="inline"><semantics> <msub> <mi>t</mi> <mrow> <mn>1</mn> <mo>/</mo> <mn>2</mn> </mrow> </msub> </semantics></math> as a function of <math display="inline"><semantics> <msub> <mi>a</mi> <mn>12</mn> </msub> </semantics></math> and <math display="inline"><semantics> <mrow> <msub> <mi>N</mi> <mn>2</mn> </msub> <mrow> <mo>(</mo> <mn>0</mn> <mo>)</mo> </mrow> </mrow> </semantics></math>. (<b>a</b>) Prediction of the analytical model, see Equation (18); (<b>b</b>) values extracted from the actual decay of <math display="inline"><semantics> <mrow> <msub> <mi>N</mi> <mn>2</mn> </msub> <mrow> <mo>(</mo> <mi>t</mi> <mo>)</mo> </mrow> </mrow> </semantics></math> obtained from the solution of the GP equations in (<a href="#FD13-applsci-11-00866" class="html-disp-formula">13</a>). The color scale is saturated at <math display="inline"><semantics> <mrow> <msub> <mi>t</mi> <mrow> <mn>1</mn> <mo>/</mo> <mn>2</mn> </mrow> </msub> <mo>=</mo> <mn>100</mn> </mrow> </semantics></math> ms (dark blue). The dashed-dotted line corresponds to <math display="inline"><semantics> <mrow> <msub> <mi>t</mi> <mrow> <mn>1</mn> <mo>/</mo> <mn>2</mn> </mrow> </msub> <mo>=</mo> <mn>50</mn> </mrow> </semantics></math> ms. The two circles at <math display="inline"><semantics> <mrow> <msub> <mi>a</mi> <mn>12</mn> </msub> <mo>=</mo> <mo>−</mo> <mn>82</mn> <msub> <mi>a</mi> <mn>0</mn> </msub> </mrow> </semantics></math> refer to the parameter configurations considered in the GP simulations of <a href="#sec4dot2-applsci-11-00866" class="html-sec">Section 4.2</a>.</p>
Full article ">Figure 3
<p>Evolution of (<b>a</b>) the droplet width <math display="inline"><semantics> <mrow> <mi>σ</mi> <mo>(</mo> <mi>t</mi> <mo>)</mo> </mrow> </semantics></math>, (<b>b</b>) the running value of <math display="inline"><semantics> <mrow> <msub> <mover accent="true"> <mi>N</mi> <mo>˜</mo> </mover> <mi>R</mi> </msub> <mrow> <mo>(</mo> <mi>t</mi> <mo>)</mo> </mrow> </mrow> </semantics></math> (see text), (<b>c</b>) the ratio <math display="inline"><semantics> <mrow> <msubsup> <mi>N</mi> <mrow> <mn>1</mn> </mrow> <mi>d</mi> </msubsup> <mrow> <mo>(</mo> <mi>t</mi> <mo>)</mo> </mrow> <mo>/</mo> <msubsup> <mi>N</mi> <mrow> <mn>2</mn> </mrow> <mi>d</mi> </msubsup> <mrow> <mo>(</mo> <mi>t</mi> <mo>)</mo> </mrow> </mrow> </semantics></math>, and (<b>d</b>) the fraction of evaporated atoms for each species <math display="inline"><semantics> <mrow> <msubsup> <mi>N</mi> <mrow> <mi>i</mi> </mrow> <mrow> <mi>e</mi> <mi>v</mi> </mrow> </msubsup> <mrow> <mo>(</mo> <mi>t</mi> <mo>)</mo> </mrow> <mo>/</mo> <msub> <mi>N</mi> <mi>i</mi> </msub> </mrow> </semantics></math>, after the release from a trap of frequency <math display="inline"><semantics> <mrow> <msub> <mi>ω</mi> <mn>2</mn> </msub> <mo>=</mo> <mn>2</mn> <mi>π</mi> <mo>×</mo> <mn>50</mn> </mrow> </semantics></math> Hz, with and without three-body losses. The insets in the top row show the total density of the binary mixture, <math display="inline"><semantics> <mrow> <mi>n</mi> <mrow> <mo>(</mo> <mi>r</mi> <mo>,</mo> <mi>t</mi> <mo>)</mo> </mrow> <mo>=</mo> <msubsup> <mo>∑</mo> <mrow> <mi>i</mi> <mo>=</mo> <mn>1</mn> </mrow> <mn>2</mn> </msubsup> <msub> <mi>N</mi> <mi>i</mi> </msub> <msup> <mrow> <mo>|</mo> <msub> <mi>ψ</mi> <mi>i</mi> </msub> <mrow> <mo>(</mo> <mi>r</mi> <mo>,</mo> <mi>t</mi> <mo>)</mo> </mrow> <mo>|</mo> </mrow> <mn>2</mn> </msup> </mrow> </semantics></math>, at different evolution times, corresponding to the red circles in (<b>a</b>). The horizontal line in (<b>b</b>) represent the <span class="html-italic">nominal</span> equilibrium value <math display="inline"><semantics> <mrow> <msub> <mi>N</mi> <mn>1</mn> </msub> <mo>/</mo> <msub> <mi>N</mi> <mn>2</mn> </msub> <mo>=</mo> <msqrt> <mrow> <msub> <mi>g</mi> <mn>22</mn> </msub> <mo>/</mo> <msub> <mi>g</mi> <mn>11</mn> </msub> </mrow> </msqrt> <mo>≃</mo> <mn>0.873</mn> </mrow> </semantics></math>, and the dashed area the corresponding tolerance (see text). Here <math display="inline"><semantics> <mrow> <msub> <mi>a</mi> <mn>12</mn> </msub> <mo>=</mo> <mo>−</mo> <mn>82</mn> <msub> <mi>a</mi> <mn>0</mn> </msub> </mrow> </semantics></math>, <math display="inline"><semantics> <mrow> <msub> <mi>N</mi> <mn>2</mn> </msub> <mo>=</mo> <mn>4</mn> <mo>×</mo> <msup> <mn>10</mn> <mn>4</mn> </msup> </mrow> </semantics></math> (left), <math display="inline"><semantics> <mrow> <msub> <mi>N</mi> <mn>2</mn> </msub> <mo>=</mo> <mn>1.5</mn> <mo>×</mo> <msup> <mn>10</mn> <mn>5</mn> </msup> </mrow> </semantics></math> (right).</p>
Full article ">
21 pages, 673 KiB  
Article
Integrating Speculation Detection and Deep Learning to Extract Lung Cancer Diagnosis from Clinical Notes
by Oswaldo Solarte Pabón, Maria Torrente, Mariano Provencio, Alejandro Rodríguez-Gonzalez and Ernestina Menasalvas
Appl. Sci. 2021, 11(2), 865; https://doi.org/10.3390/app11020865 - 19 Jan 2021
Cited by 13 | Viewed by 3404
Abstract
Despite efforts to develop models for extracting medical concepts from clinical notes, there are still some challenges in particular to be able to relate concepts to dates. The high number of clinical notes written for each single patient, the use of negation, speculation, [...] Read more.
Despite efforts to develop models for extracting medical concepts from clinical notes, there are still some challenges in particular to be able to relate concepts to dates. The high number of clinical notes written for each single patient, the use of negation, speculation, and different date formats cause ambiguity that has to be solved to reconstruct the patient’s natural history. In this paper, we concentrate on extracting from clinical narratives the cancer diagnosis and relating it to the diagnosis date. To address this challenge, a hybrid approach that combines deep learning-based and rule-based methods is proposed. The approach integrates three steps: (i) lung cancer named entity recognition, (ii) negation and speculation detection, and (iii) relating the cancer diagnosis to a valid date. In particular, we apply the proposed approach to extract the lung cancer diagnosis and its diagnosis date from clinical narratives written in Spanish. Results obtained show an F-score of 90% in the named entity recognition task, and a 89% F-score in the task of relating the cancer diagnosis to the diagnosis date. Our findings suggest that speculation detection is together with negation detection a key component to properly extract cancer diagnosis from clinical notes. Full article
(This article belongs to the Special Issue Integration and Mining of Data from Mobile Devices)
Show Figures

Figure 1

Figure 1
<p>Medical history fragments.</p>
Full article ">Figure 2
<p>Approach to extract lung cancer diagnosis.</p>
Full article ">Figure 3
<p>Bidirectional Long Short-Term Memory/Conditional Random Field (BiLSTM-CRF) model.</p>
Full article ">Figure 4
<p>Strategy to generate the cues lexicon.</p>
Full article ">Figure 5
<p>Related words to the cue “Probable”.</p>
Full article ">Figure 6
<p>Scope using a Parse tree.</p>
Full article ">Figure 7
<p>Parse tree: linking dates and cancer diagnosis.</p>
Full article ">
19 pages, 5011 KiB  
Article
POP-ON: Prediction of Process Using One-Way Language Model Based on NLP Approach
by Junhyung Moon, Gyuyoung Park and Jongpil Jeong
Appl. Sci. 2021, 11(2), 864; https://doi.org/10.3390/app11020864 - 18 Jan 2021
Cited by 14 | Viewed by 3984
Abstract
In business process management, the monitoring service is an important element that can prevent various problems in advance from before they occur in companies and industries. Execution log is created in an information system that is aware of the enterprise process, which helps [...] Read more.
In business process management, the monitoring service is an important element that can prevent various problems in advance from before they occur in companies and industries. Execution log is created in an information system that is aware of the enterprise process, which helps predict the process. The ultimate goal of the proposed method is to predict the process following the running process instance and predict events based on previously completed event log data. Companies can flexibly respond to unwanted deviations in their workflow. When solving the next event prediction problem, we use a fully attention-based transformer, which has performed well in recent natural language processing approaches. After recognizing the name attribute of the event in the natural language and predicting the next event, several necessary elements were applied. It is trained using the proposed deep learning model according to specific pre-processing steps. Experiments using various business process log datasets demonstrate the superior performance of the proposed method. The name of the process prediction model we propose is “POP-ON”. Full article
(This article belongs to the Special Issue Artificial Intelligence and Machine Learning in Software Engineering)
Show Figures

Figure 1

Figure 1
<p>Diagram illustrating inter-dependencies between event logs.</p>
Full article ">Figure 2
<p>Process prediction using n-gram and feature hashing approaches.</p>
Full article ">Figure 3
<p>Overall data pre-processing.</p>
Full article ">Figure 4
<p>Example of using one-hot encoding.</p>
Full article ">Figure 5
<p>POP-ON (Prediction of Process Using One-way Language Model based on NLP Approach) model architecture.</p>
Full article ">Figure 6
<p>Appearance of the train process and test process.</p>
Full article ">Figure 7
<p>Illustrative diagram of the loan process.</p>
Full article ">Figure 8
<p>POP-ON explanation through a real-world example.</p>
Full article ">Figure 9
<p>Model test performance comparison according to the attribute linear layer.</p>
Full article ">
14 pages, 35846 KiB  
Article
The Effect of Taper and Apical Diameter on the Cyclic Fatigue Resistance of Rotary Endodontic Files Using an Experimental Electronic Device
by Vicente Faus-Llácer, Nirmine Hamoud Kharrat, Celia Ruiz-Sánchez, Ignacio Faus-Matoses, Álvaro Zubizarreta-Macho and Vicente Faus-Matoses
Appl. Sci. 2021, 11(2), 863; https://doi.org/10.3390/app11020863 - 18 Jan 2021
Cited by 10 | Viewed by 3338
Abstract
The aim of this study was to analyze the effect of the taper and apical diameter of nickel–titanium (NiTi) endodontic rotary files on the dynamic cyclic fatigue resistance. A total of 50 unused conventional NiTi wire alloy endodontic rotary instruments were used in [...] Read more.
The aim of this study was to analyze the effect of the taper and apical diameter of nickel–titanium (NiTi) endodontic rotary files on the dynamic cyclic fatigue resistance. A total of 50 unused conventional NiTi wire alloy endodontic rotary instruments were used in this study. All NiTi endodontic rotary files were submitted to a custom-made dynamic cyclic fatigue device until fracture occurred. The time to failure, the number of cycles to failure, the number of pecking movements, and the length of the fractured file tip were analyzed using the analysis of variance (ANOVA) test. In addition, the Weibull characteristic strength and Weibull modulus were also calculated. The paired t-test revealed statistically significant differences between the time to failure, number of cycles to failure, and number of cycles of in-and-out movement of both the apical diameter (p ˂ 0.001) and the taper (p ˂ 0.001) of NiTi endodontic rotary files; however, the results did not show statistically significant differences between the mean length of the fractured files regarding the apical diameter (p = 0.344) and taper study groups (p = 0.344). Increased apical diameter and taper of NiTi endodontic rotary files decreased their dynamic resistance to cyclic fatigue. Full article
(This article belongs to the Special Issue Advance of the Mechanical Properties of Dental Materials)
Show Figures

Figure 1

Figure 1
<p>Scanning electron microscopy (SEM) analysis of the taper of (<b>A</b>) 25.02, (<b>B</b>) 25.04, (<b>C</b>) 25.06, (<b>D</b>) 20.06, and (<b>E</b>) 30.06 NiTi endodontic rotary files.</p>
Full article ">Figure 2
<p>SEM analysis of the apical diameter of (<b>A</b>) 25.02, (<b>B</b>) 25.04, (<b>C</b>) 25.06, (<b>D</b>) 20.06, and (<b>E</b>) 30.06 NiTi endodontic rotary files.</p>
Full article ">Figure 3
<p>(<b>A</b>) Front, (<b>B</b>) back, and (<b>C</b>,<b>D</b>) lateral surfaces of the dynamic cyclic fatigue hardware device.</p>
Full article ">Figure 4
<p>(<b>A</b>) Back and (<b>B</b>) front surfaces of the 3D design of the dynamic cyclic fatigue hardware device, with the reduction handpiece (<b>C</b>) located on the top of the dynamic cyclic fatigue hardware device and the NiTi endodontic rotary file (<b>D</b>) inside the artificial root canal.</p>
Full article ">Figure 5
<p>Box plots of the time to failure for the (<b>A</b>) apical diameter and (<b>B</b>) taper study groups. The horizontal line in each box represents the respective median value.</p>
Full article ">Figure 6
<p>Weibull probability plots of the time to failure for the (<b>A</b>) apical diameter and (<b>B</b>) taper study groups.</p>
Full article ">Figure 7
<p>Box plots of the number of cycles to failure for the (<b>A</b>) apical diameter and (<b>B</b>) taper study groups. The horizontal line in each box represents the median value.</p>
Full article ">Figure 8
<p>The Weibull probability plots of the number of cycles to failure for the (<b>A</b>) apical diameter and (<b>B</b>) taper study groups.</p>
Full article ">Figure 9
<p>Box plots of the number of cycles of in-and-out movements for the (<b>A</b>) apical diameter and (<b>B</b>) taper study groups. The horizontal line in each box represents the respective median value.</p>
Full article ">Figure 10
<p>Weibull probability plots of the number of cycles of in-and-out movements for the (<b>A</b>) apical diameter and (<b>B</b>) taper study groups.</p>
Full article ">Figure 11
<p>Box plots of the length of fractured files regarding the (<b>A</b>) apical diameter and (<b>B</b>) taper study groups. The horizontal line in each box represents the respective median value.</p>
Full article ">Figure 12
<p>The Weibull probability plots of the length of fractured files regarding the (<b>A</b>) apical diameter and (<b>B</b>) taper study groups.</p>
Full article ">
12 pages, 1577 KiB  
Article
The Effects of 3D and 2D Imaging on Brain Wave Activity in Laparoscopic Training
by Hung-Jen Chen, Chiuhsiang Joe Lin, Po-Hung Lin and Zong-Han Guo
Appl. Sci. 2021, 11(2), 862; https://doi.org/10.3390/app11020862 - 18 Jan 2021
Cited by 3 | Viewed by 1937
Abstract
The current study tested the effects of a state-of-the-art stereoscopic three-dimensional (3D) display and a traditional two-dimensional (2D) display on performance and mental workload during simulated laparoscopic tasks with different levels of depth perception over a longer duration than in previous publications. Two [...] Read more.
The current study tested the effects of a state-of-the-art stereoscopic three-dimensional (3D) display and a traditional two-dimensional (2D) display on performance and mental workload during simulated laparoscopic tasks with different levels of depth perception over a longer duration than in previous publications. Two different simulated laparoscopic tasks with depth perception, peg transfer, and circle-tracing were performed by 12 participants using 2D and 3D vision systems. The task performances (mean completion time and mean error frequency) and mental workload measures (gamma and alpha brain wave activity, blink frequency and NASA-TLX ratings) were recorded as dependent variables. The physiological mental workload measures were collected via a MUSE EEG headband. The 3D vision system had advantages in mean movement time and mean error frequency in the depth-perception peg transfer task. The mean completion time of the non-depth perception circle-tracing task was significantly lower for 2D than for 3D. For the peg transfer task, EEG alpha wave activity was significantly higher for 3D than for 2D. The EEG gamma wave activity for 2D was significantly higher than that for 3D in both tasks. A significantly higher blink frequency was found for both the peg transfer task and the 3D system. The overall NASA-TLX score of the 2D system was significantly higher. The findings of this research suggest that a 3D vision system could decrease stress, state of attentiveness, and mental workload compared with those of a 2D system, and it might reduce the completion time and increase the precision of depth-perception laparoscopic operations. Full article
Show Figures

Figure 1

Figure 1
<p>Experimental environment.</p>
Full article ">Figure 2
<p>Peg transfer task.</p>
Full article ">Figure 3
<p>The digitizer tablet and modified Endo Babcock clamp with a digital pen used in the circle-tracing task.</p>
Full article ">
10 pages, 2877 KiB  
Article
Functional Characterization of Marigold Powder as a Food Ingredient for Lutein-Fortified Fresh Noodles
by Seungkyun Nam, Chan-Yang Lee, Soon-Mi Shim, Dong-Un Lee and Suyong Lee
Appl. Sci. 2021, 11(2), 861; https://doi.org/10.3390/app11020861 - 18 Jan 2021
Cited by 4 | Viewed by 3074
Abstract
Marigold powder was utilized as a food ingredient to produce lutein-fortified fresh noodles for eye health, and its functionalities were characterized in terms of thermo-rheological, structural, and antioxidant properties. The pasting parameters and starch-gelatinization enthalpy values of wheat flour had a tendency to [...] Read more.
Marigold powder was utilized as a food ingredient to produce lutein-fortified fresh noodles for eye health, and its functionalities were characterized in terms of thermo-rheological, structural, and antioxidant properties. The pasting parameters and starch-gelatinization enthalpy values of wheat flour had a tendency to decrease with increasing levels of marigold powder. The use of marigold powder led to decreases in the storage and loss moduli of wheat flour pastes by weakening their cellular microstructure, which was confirmed by the scanning electron microscopic images. When marigold powder was incorporated into the formulation of fresh noodles, the cooking loss and water absorption of the noodles were not negatively affected at a level of 2% (w/w). Also, the noodles with 2% marigold powder were not significantly different from the control for the maximum resistance to extension. The levels of lutein in the noodles prepared with marigold powder (61.2 to 204.9 mg/100 g) were reduced by almost 50% after cooking. However, they seemed to satisfy the recommended daily dose of lutein for visual functions. Moreover, the use of marigold powder provided antioxidant properties for noodles by enhancing the 2,2′-diphenyl-1-picrylhydrazyl (DPPH) and 2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical-scavenging activities. Full article
(This article belongs to the Section Food Science and Technology)
Show Figures

Figure 1

Figure 1
<p>Effect of marigold powder on the pasting (<b>a</b>) and thermal (<b>b</b>) properties of wheat flour (means with different letters in the same column differ significantly at <span class="html-italic">p</span> &lt; 0.05).</p>
Full article ">Figure 2
<p>Changes in the viscoelastic properties of wheat flour pastes by marigold powder (G′ (<b>a</b>) and G″ (<b>b</b>)).</p>
Full article ">Figure 3
<p>Microstructural changes of wheat flour pastes by marigold powder (×1000 magnification).</p>
Full article ">Figure 4
<p>Effect of marigold powder on the cooking loss (<b>a</b>) and water absorption (<b>b</b>) of fresh noodles (means with different letters on the bars differ significantly at <span class="html-italic">p</span> &lt; 0.05).</p>
Full article ">Figure 5
<p>The lutein contents of the noodles prepared with marigold powder before and after cooking (ND: not detected, means with different letters on the bars differ significantly at <span class="html-italic">p</span> &lt; 0.05).</p>
Full article ">Figure 6
<p>The antioxidant activities of the noodles prepared with marigold powder before and after cooking (DPPH (<b>a</b>) and ABTS (<b>b</b>)) (means with different letters on the bars differ significantly at <span class="html-italic">p</span> &lt; 0.05).</p>
Full article ">
23 pages, 2445 KiB  
Article
Active Clamp Boost Converter with Blanking Time Tuning Considered
by Yeu-Torng Yau, Kuo-Ing Hwu and Yu-Kun Tai
Appl. Sci. 2021, 11(2), 860; https://doi.org/10.3390/app11020860 - 18 Jan 2021
Cited by 3 | Viewed by 2672
Abstract
An active clamp boost converter with blanking time auto-tuned is presented herein, and this is implemented by an additional auxiliary switch, an additional resonant inductor, and an additional active clamp capacitor as compared with the conventional boost converter. In this structure, both the [...] Read more.
An active clamp boost converter with blanking time auto-tuned is presented herein, and this is implemented by an additional auxiliary switch, an additional resonant inductor, and an additional active clamp capacitor as compared with the conventional boost converter. In this structure, both the main and auxiliary switches have zero voltage switching (ZVS) turn-on as well as the output diode has zero current switching (ZCS) turn-off, causing the overall efficiency of the converter to be upgraded. Moreover, as the active clamp circuit is adopted, the voltage spike on the main switch can be suppressed to some extent whereas, because of this structure, although the input inductor is designed in the continuous conduction mode (CCM), the output diode can operate with ZCS turn-off, leading to the resonant inductor operating in the discontinuous conduction mode (DCM), hence there is no reverse recovery current during the turn-off period of the output diode. Furthermore, unlike the existing soft switching circuits, the auto-tuning technique based on a given look-up table is added to adjust the cut-off time point of the auxiliary switch to reduce the current flowing through the output diode, so that the overall efficiency is upgraded further. In this paper, basic operating principles, mathematic deductions, potential designs, and some experimental results are given. To sum up, the novelty of this paper is ZCS turn-off of the output diode, DCM operation of the resonant inductor, and auto-tuning of cut-off time point of the auxiliary switch. In addition, the efficiency of the proposed converter can be up to 96.9%. Full article
(This article belongs to the Special Issue Resonant Converter in Power Electronics Technology)
Show Figures

Figure 1

Figure 1
<p>Proposed active clamp boost converter.</p>
Full article ">Figure 2
<p>Equivalent circuit of the circuit shown in <a href="#applsci-11-00860-f001" class="html-fig">Figure 1</a>.</p>
Full article ">Figure 3
<p>Key waveforms pertaining to the working converter.</p>
Full article ">Figure 4
<p>(<b>a</b>) Current path for stage 1; (<b>b</b>) equivalent of (<b>a</b>).</p>
Full article ">Figure 5
<p>(<b>a</b>) Current path for stage 2; (<b>b</b>) equivalent of (<b>a</b>).</p>
Full article ">Figure 6
<p>(<b>a</b>) Current path for stage 3; (<b>b</b>) equivalent of (<b>a</b>).</p>
Full article ">Figure 7
<p>(<b>a</b>) Current path for stage 4; (<b>b</b>) equivalent of (<b>a</b>).</p>
Full article ">Figure 8
<p>(<b>a</b>) Current path for stage 5; (<b>b</b>) equivalent of (<b>a</b>).</p>
Full article ">Figure 9
<p>(<b>a</b>) Current path for stage 6; (<b>b</b>) equivalent of (<b>a</b>).</p>
Full article ">Figure 10
<p>(<b>a</b>) Current path for stage 7; (<b>b</b>) equivalent of (<b>a</b>).</p>
Full article ">Figure 11
<p>(<b>a</b>) Current path for stage 8; (<b>b</b>) equivalent of (<b>a</b>).</p>
Full article ">Figure 12
<p>(<b>a</b>) Current path for stage 9; (<b>b</b>) equivalent of (<b>a</b>).</p>
Full article ">Figure 13
<p>(<b>a</b>) System operation flow chart; (<b>b</b>) look-up table operation flow chart. PWM, pulse width modulation.</p>
Full article ">Figure 14
<p>Auto-tuning technique with X and Y called the first blanking time and the second blanking time, respectively: (<b>a</b>) with <math display="inline"><semantics> <mrow> <mi mathvariant="normal">X</mi> <mo>=</mo> <mi mathvariant="normal">Y</mi> </mrow> </semantics></math> ; (<b>b</b>) with <math display="inline"><semantics> <mrow> <mi mathvariant="normal">X</mi> <mo>≠</mo> <mi mathvariant="normal">Y</mi> </mrow> </semantics></math>.</p>
Full article ">Figure 15
<p>Experimental waveforms: (1) <span class="html-italic">v<sub>gs</sub></span><sub>1</sub>; (2) <span class="html-italic">v<sub>gs</sub></span><sub>2</sub>.</p>
Full article ">Figure 16
<p>Experimental waveforms: (1) <span class="html-italic">v<sub>gs</sub></span><sub>1</sub>; (2) <span class="html-italic">v<sub>d</sub></span><sub>s1</sub>; (3) <span class="html-italic">i<sub>d</sub></span><sub>s1</sub>.</p>
Full article ">Figure 17
<p>Experimental waveforms: (1) <span class="html-italic">v<sub>gs</sub></span><sub>2</sub>; (2) <span class="html-italic">v<sub>d</sub></span><sub>s2</sub>; (3) <span class="html-italic">i<sub>d</sub></span><sub>s2</sub>.</p>
Full article ">Figure 18
<p>Experimental waveforms: (1) <span class="html-italic">v<sub>c</sub></span>; (2) <span class="html-italic">i<sub>Lr</sub></span>.</p>
Full article ">Figure 19
<p>Efficiency test bench. (DC: direct current; FPGA: field programmable gate array).</p>
Full article ">Figure 20
<p>Efficiency comparison.</p>
Full article ">
Previous Issue
Back to TopTop