3D Mode Research Articles

Raman modes and mapping of graphene nanoparticles on Si and photonic crystal substrates

Mapping of photonic crystal (PC) surface infiltrated by graphene nanoparticles (GNP) has been done for D, G, and 2D mode and compared with those for GNP deposited on Si substrate. We've collected numerous spectra (from about 1000 points) and the changes in D, G, and 2D modes intensity ratio, as well as minor changes in frequency position for both GNP samples, have been detected. The samples were extremely heterogeneous in spectroscopic features. A suppression of luminescence intensity from the opal-based PC after the infiltration of GNP into interglobular cavities of the PC was registered together with up to 3–10 times enhancement of the Raman signal from the GNP which is important for the development of enhanced spectroscopic techniques. Thus, graphene showed a property of suppression of luminescence from the PC similar to a metallic substrate and could be applied as a luminescence quencher and light absorber. These data are confirmed by finite-difference time-domain (FDTD) calculations.

Comparison of utility of deep learning reconstruction on 3D MRCPs obtained with three different k-space data acquisitions in patients with IPMN.

To compare the utility of deep learning reconstruction (DLR) for improving acquisition time, image quality, and intraductal papillary mucinous neoplasm (IPMN) evaluation for 3D MRCP obtained with parallel imaging (PI), multiple k-space data acquisition for each repetition time (TR) technique (Fast 3D mode multiple: Fast 3Dm) and compressed sensing (CS) with PI. A total of 32 IPMN patients who had undergone 3D MRCPs obtained with PI, Fast 3Dm, and CS with PI and reconstructed with and without DLR were retrospectively included in this study. Acquisition time, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) obtained with all protocols were compared using Tukey's HSD test. Results of endoscopic ultrasound, ERCP, surgery, or pathological examination were determined as standard reference, and distribution classifications were compared among all 3D MRCP protocols by McNemar's test. Acquisition times of Fast 3Dm and CS with PI with and without DLR were significantly shorter than those of PI with and without DLR (p < 0.05). Each MRCP sequence with DLR showed significantly higher SNRs and CNRs than those without DLR (p < 0.05). IPMN distribution accuracy of PI with and without DLR and Fast 3Dm with DLR was significantly higher than that of Fast 3Dm without DLR and CS with PI without DLR (p < 0.05). DLR is useful for improving image quality and IPMN evaluation capability on 3D MRCP obtained with PI, Fast 3Dm, or CS with PI. Moreover, Fast 3Dm and CS with PI may play as substitution to PI for MRCP in patients with IPMN. • Mean examination times of multiple k-space data acquisitions for each TR and compressed sensing with parallel imaging were significantly shorter than that of parallel imaging (p < 0.0001). • When comparing image quality of 3D MRCPs with and without deep learning reconstruction, deep learning reconstruction significantly improved signal-to-noise ratio and contrast-to-noise ratio (p < 0.05). • IPMN distribution accuracies of parallel imaging with and without deep learning reconstruction (with vs. without: 88.0% vs. 88.0%) and multiple k-space data acquisitions for each TR with deep learning reconstruction (86.0%) were significantly higher than those of others (p < 0.05).

A Novel Immersive Anatomy Education System (Anat_Hub): Redefining Blended Learning for the Musculoskeletal System

Immersive technologies are redefining ways of interacting with 3D objects and their environments. Moreover, efforts in blended learning have presented several advantages of incorporating educational technology into the learning space. The advances in educational technology have in turn helped to widen the choice of different pedagogies for improving learner engagement and levels of understanding. However, there is limited research in anatomy education that has considered the use and adoption of immersive technologies for the musculoskeletal system, despite its immense advantage. This research presents a practical immersive anatomy education system (coined Anat_Hub) developed using the agile scrum and participatory design method at a selected tertiary institution in Cape Town, South Africa, which promotes learner engagement through an asynchronous technological means using augmented reality (AR). The aim of the study was to develop an immersive AR mobile application that will assist learners and educators in studying and teaching the names, attachments, and actions of muscles of the human musculoskeletal system (upper and lower limbs). The Anat_Hub application offers a wide range of useful features for promoting active and self-regulated learning, such as 3D and AR modes, glossary, and quiz features. The application was tested with potential users, and on a variety of mobile device specifications. Very few volunteers have used AR prior to this study (13.2%). On a scale of 1 to 5, the majority of volunteers scored the application a 4 or 5. Overall, results and feedback obtained from users show that the proposed immersive anatomy system could effectively improve learner engagement and retention of anatomy concepts.

37‐4: Student Paper: Depth‐Enhanced 2D/3D Switchable Display Based on Integral Imaging

The development of two‐dimensional (2D)/three‐dimensional (3D) switchable displays in the display market is limited due to the narrow depth of 3D display mode. In this paper, we propose a depth‐enhanced 2D/3D switchable display based on integral imaging that stacks multiple polarization switching layers and multiple polarization‐dependent liquid crystal micro‐lens arrays (LCMLAs) together. According to the change of the incident polarization state by the polarization switching layer, the polarization‐dependent LCMLA can realize the focusing effect and transmission effect respectively. Because different layers of polarization‐dependent LCMLA have different gaps (g) and the combination of different layers of polarization‐dependent LCMLA obtains different focal lengths (f), hence, multiple central depth planes can be generated to improve the depth of field (DOF) of the 3D mode. The 2D display mode is realized when all the layers of the polarization‐dependent LCMLA are in transmission effect. We experimentally developed a prototype of the proposed 2D/3D switchable display with two polarization switching layers and two polarization‐dependent LCMLAs. The results show that the DOF of the prototype is easily increased by more than two times. At the same time, the 2D image is also clearly presented in 2D mode without any distortion.

Comparing self-navigation and video mode in a choice experiment to measure public space preferences

3D dynamic visualization technologies are increasingly used in studying residents' preferences for urban planning and design scenarios. The techniques help concentrate respondent attention and improve the measurement quality of environmental preferences. However, little is known about differences in measurement quality between different 3D dynamic visualization modes. This paper applies two modes – a self-navigation mode and a video mode - in a virtual environment-based stated choice experiment with the aim of measuring neighborhood public spaces preferences. Based on data from 276 experiment participants and applying conditional and mixed logit techniques, we find no statistically significant differences in the model fit between the two modes. Out of six public space attributes, only one shows statistically significant differences in valuation between modes, namely ‘vertical green’. Our results suggest that the choice between video and self-navigation modes can be based on other (secondary) considerations, i.e., required sample size, respondents' experiences with navigation interfaces, the specific goals of the study or application in practice, and the costs and effort needed to conduct the experiment.

Confiabilidad interevaluador de la medición de la excursión diafragmática y fracción de engrosamiento diafragmático mediante ultrasonografía en voluntarios sanos

Background and objectiveTo determine the inter-rater reliability in the ultrasonographic (US) measurement of the diaphragmatic excursion (DE) and the diaphragm thickness fraction (DTF) performed by non-medical health professionals in healthy people. Participants and methodsProspective observational study in a third level hospital in Cali, Colombia. Measurements were made to 30 healthy volunteers chosen by convenience sampling, without a history of lung diseases, with ages between 18-60 years. A pilot test was previously carried out with 8 healthy volunteers. US measurements of DE, and DTF were based on previously published protocols. Each assessor independently observed several cycles of normal quiet breathing for 3minutes to establish a baseline. The Intraclass Correlation Index (ICC) was used to evaluate the inter-rater reliability in the measurements of DE and DTF, with 95% confidence intervals and a P<.05. ResultsSubstantial agreement was identified in the measurement of DE in the splenic and hepatic windows because the ICC was greater than 0.6 (P<.05). The measurement of the DTF in the hepatic window showed slight agreement in both 2D and M modes (P>.05). In the splenic window, the measurement of the DTF in the 2D mode was found to be moderate agreement and for the M mode a slight agreement was found (P>.05) ConclusionsThe diaphragmatic US constitutes a reproducible method with acceptable inter-rater reliability for the measurement of inspiratory/expiratory thickness, and with little reliability for the measurement of DTF.

Ultrafast Vibrational Dephasing Times of Modified Graphene

We have measured the ultrafast dephasing times of vibrational quanta in functional groups covalently bound to graphene. It has been previously shown that electronic relaxation in graphene occurs on subpicosecond timescales, but this is the first venture into the vibrational dephasing times in functionalized graphene. We have employed time-resolved sum-frequency generation spectroscopy to observe the decay of the coherent signal arising due to vibrational excitation by delaying the upconversion pulse with respect to the infrared (IR) laser pulse. We observe decay times of 0.8 and 1.4 ps for vibrational stretches in phenyl groups attached to graphene or gold, respectively, but for the vibrations of the bond covalently connecting H atoms to graphene in hydrogenated graphene, we measure much faster decay times of 0.3 ps. This is likely due to coupling between the C–H stretch and either the two-dimensional (2D) mode of graphene or nonadiabatic coupling to electrons photoexcited by the upconversion laser pulse.

Resolution-preserving passive 2D/3D convertible display based on holographic optical elements.

We propose and demonstrate a resolution-preserving passive 2D/3D convertible display by two individual wavelengths. It uses a holographic optical element to generate two images and passively separate the exit pupils for these two wavelengths, which forms two viewpoints for each of the observer's eyes. Due to Bragg-mismatched reconstruction of two similar but distinct wavelengths, the images are separated in space. They can be fused into one through the convergence function of human eyes. By switching the input image source, the conversion between 2D and 3D mode can be realized. This method is resolution-preserving and 2D/3D convertible with no extra active components. For experimental verification, a proof-of-concept projection-type prototype is assessed.

Macrophage network dynamics depend on haptokinesis for optimal local surveillance

Macrophages are key immune cells with important roles for tissue surveillance in almost all mammalian organs. Cellular networks made up of many individual macrophages allow for optimal removal of dead cell material and pathogens in tissues. However, the critical determinants that underlie these population responses have not been systematically studied. Here, we investigated how cell shape and the motility of individual cells influences macrophage network responses in 3D culture settings and in mouse tissues. We show that surveying macrophage populations can tolerate lowered actomyosin contractility, but cannot easily compensate for a lack of integrin-mediated adhesion. Although integrins were dispensable for macrophage chemotactic responses, they were crucial to control cell movement and protrusiveness for optimal surveillance by a macrophage population. Our study reveals that β1 integrins are important for maintaining macrophage shape and network sampling efficiency in mammalian tissues, and sets macrophage motility strategies apart from the integrin-independent 3D migration modes of many other immune cell subsets.

Numerical study of coastal wave profiles at the sandy beaches of Nowshahr (Southern Caspian Sea)

This study aimed to investigate the capability of the one-dimensional (1D) mode of the Simulating WAves till SHore (SWASH), as a non-hydrostatic wave-flow model with six vertical layers, to reproduce the cross-shore wave evolution. For this purpose, the given model was initially calibrated for wave energy and the outputs were then verified with the field data measured at the Southern Caspian Sea. The calibration coefficients obtained for wave breaking are significantly less than the ones which have been mostly reported in previous studies for the two-dimensional (2D) mode of the SWASH. Although the reproduced wave height parameters are generally in good accordance with the field observations, the period parameters and the number of waves are overestimated and underestimated by the model, respectively. Moreover, the inaccuracies at the shallow stations are worse than at the transitional depths. The overestimation in both the reproduced energy of infragravity waves (IG) and their wavelength along with the underestimation in the wind-wave energy content are also among the factors responsible for the model deficiencies. The findings have revealed that the overestimation of the reproduced IG waves is the main reason for the underestimation of the breaking dissipation rate for irregular wave trains in the 1D mode. Therefore, more intensive breaking dissipation via selecting lower coefficient values is necessary to exhaust a certain energy content from longer waves in the 1D mode. This approach ultimately induces an over-dissipation of short wind-waves.

Efficient Reduced Order Modeling of Large Data Sets Obtained from CFD Simulations

The ever-increasing computational power has shifted direct numerical simulations towards higher Reynolds numbers and large eddy simulations towards industrially-relevant flow scales. However, this increase in both temporal and spatial resolution has severely increased the computational cost of model order reduction techniques. Reducing the full data set to a smaller subset in order to perform reduced-order modeling (ROM) may be an interesting method to keep the computational effort reasonable. Moreover, non-tomographic particle image velocimetry measurements obtain a 2D data set of a 3D flow field and an interesting research question would be to quantify the difference between this 2D ROM compared to the 3D ROM of the full flow field. To provide an answer to both issues, the aim of this study was to test a new method for obtaining POD basis functions from a small subset of data initially and using them afterwards in the ROM of either the complete data set or the reduced data set. Hence, no new method of ROM is presented, but we demonstrate a procedure to significantly reduce the computational effort required for the ROM of very large data sets and a quantification of the error introduced by reducing the size of those data sets. The method applies eigenvalue decomposition on a small subset of data extracted from a full 3D simulation and the obtained temporal coefficients are projected back on the 3D velocity fields to obtain the 3D spatial modes. To test the method, an annular jet was chosen as a flow topology due to its simple geometry and the rich dynamical content of its flow field. First, a smaller data set is extracted from the 2D cross-sectional planes and ROM is performed on that data set. Secondly, the full 3D spatial structures are reconstructed by projecting the temporal coefficients back on the 3D velocity fields and the 2D spatial structures by projecting the temporal coefficients back on the 2D velocity fields. It is shown that two perpendicular lateral planes are sufficient to capture the relevant large-scale structures. As such, the total processing time can be reduced by a factor of 136 and up to 22 times less RAM is needed to complete the ROM processing.

The Effect of Heavy Fe-Doping on 3D Growth Mode and Fe Diffusion in GaN for High Power HEMT Application.

The high electron mobility transistor (HEMT) structures on Si (111) substrates were fabricated with heavily Fe-doped GaN buffer layers by metalorganic chemical vapor deposition (MOCVD). The heavy Fe concentrations employed for the purpose of highly insulating buffer resulted in Fe segregation and 3D island growth, which played the role of a nano-mask. The in situ reflectance measurements revealed a transition from 2D to 3D growth mode during the growth of a heavily Fe-doped GaN:Fe layer. The 3D growth mode of Fe nano-mask can effectively annihilate edge-type threading dislocations and improve transfer properties in the channel layer, and consequently decrease the vertical leakage current by one order of magnitude for the applied voltage of 1000 V. Moreover, the employment of GaN:C film on GaN:Fe buffer can further reduce the buffer leakage-current and effectively suppress Fe diffusion.

ОПРЕДЕЛЕНИЕ ПАРАМЕТРОВ СХЕМЫ ЗАМЕЩЕНИЯ АСИНХРОННОГО ДВИГАТЕЛЯ С КОЛЬЦЕВЫМИ ОБМОТКАМИ

Induction motors with ring windings (IMRW) are designed for the processing of nuclear waste. The sta-tor winding coils are covered with ceramic insulation to allow for long-term operation in conditions of increased radiation. The stator coils are ring shaped, in order to reduce the bend angle. The stator has a specific design consisting of tooth tips located around the axis of rotation and tooth cores placed over the tooth tips in a spiral. The first IMRW prototype was manufactured by UrFU together with “Uralelectromash”. It was designed to the same diameters as an induction motor of a classical design with a power P = 2.2 kW, with a synchronous rotation speed n = 1000 rpm. The fundamentally new ar-mature design involves the search for new solutions for determining machine parameters, such as inductances, electro-magnetic torques. The article discusses a method of equivalent circuit parameter calculation for IMRW using the “ANSYS Maxwell” in 3D mode. In order to determine stator winding leakage inductances, a static analysis of the model with the ro-tor removed was used. Mutual inductance is defined as the difference between stator winding phase impedance and leak-age inductance. The active resistance of the magnetizing circuit and the impedance of the motor can be determined using the IMRW no-load and short-circuit characteristics obtained in ANSYS Maxwell. The paper also provides an example of calculating the mechanical characteristics of a motor using the analytical method (AM).This involves the use of equivalent circuit parameters, and the finite element method (FEM). The use of FEM for calculating the mechanical characteristics implies the analysis of IMRW in a dynamic mode. This allows the electromagnetic torque to be determined at a user-specified rotor speed. In conclusion, a comparative analysis of the parameters of a classic engine and IMRW engine, of the same size, is given. Recommendations are given for further improvement of the design of IMRW engines.

Global and local modal characteristics of supersonic open cavity flows

Flows past cavities at high-speeds have become increasingly important in applications such as flame-holding and propulsion unstart control. Recently maturated linear techniques have helped discern the underlying mechanisms in the subsonic and low supersonic speed regime (M∞&amp;lt;1.4). Here, we combine these linear methods with fully non-linear two- and three-dimensional simulations to assimilate the significant changes observed when the Mach number is increased further to the 1.4≤M∞≤3 range. The resolvent method is first employed to analyze cavity-shear layer coupled oscillations and modal characteristics, which are found to differ in key respects from those reported at lower Mach numbers. At higher speeds, more 2D coupled modes are obtained with the dominant modes containing secondary waves displaying elaborate patterns. The role of the shear layer on the cavity dynamics is then examined with local spatial stability analyses. In addition to the well-known Kelvin–Helmholtz instability encountered in the subsonic and transonic regimes, forward-propagating (k+) supersonic shear layer instabilities are detected at higher speeds. These are associated with Mach wave reflections between the shear layer and the cavity floor and may introduce higher order coupled modes. Furthermore, 3D modal analysis indicates a shift toward the dominance of 3D modes compared to 2D modes; although consistent with compressible free shear layer observations, 2D cavity modes remain significant to higher convective Mach number. When the Reynolds number is increased, resolvent-based mode shapes and frequencies continue to compare favorably with Dynamic Mode Decomposition of large-eddy simulations because of inviscid instability dominance.

Rapid evaluation of notch stress intensity factors using the peak stress method with 3D tetrahedral finite element models: Comparison of commercial codes

AbstractThe peak stress method (PSM) allows a rapid application of the notch stress intensity factor (NSIF) approach to the fatigue life assessment of welded structures, by employing the linear elastic peak stresses evaluated by FE analyses with coarse meshes. Because of the widespread adoption of 3D modeling of large and complex structures in the industry, the PSM has recently been boosted by including four‐node and ten‐node tetrahedral elements of Ansys FE software, which allows to discretize complex geometries. In this paper, a Round Robin among eleven Italian Universities has been performed to calibrate the PSM with seven different commercial FE software packages. Several 3D mode I, II and III problems have been considered to investigate the influence of (i) FE code, (ii) element type, (iii) mesh pattern, and (iv) procedure to extrapolate stresses at FE nodes. The majority of the adopted FE software packages present similar values of the PSM parameters, the main source of discrepancy being the stress extrapolation method at FE nodes.

Enhancement of graphene-related and substrate-related Raman modes through dielectric layer deposition

In this report, we demonstrate a method for the enhancement of Raman active modes of hydrogen-intercalated quasi-free-standing epitaxial chemical vapor deposition graphene and the underlying semi-insulating 6H–SiC(0001) substrate through constructive signal interference within atomic-layer-deposited amorphous Al2O3 passivation. We find that an optimum Al2O3 thickness of 85 nm for the graphene 2D mode and one of 82 nm for the SiC longitudinal optical A1 mode at 964 cm–1 enable a 60% increase in their spectra intensities. We demonstrate the method's efficiency in Raman-based determination of the dielectric thickness and high-resolution topographic imaging of a graphene surface.

Early predictors of systolic right ventricular dysfunction in the diagnostic algorithm in young patients with pulmonary sarcoidosis

Abstract Funding Acknowledgements Type of funding sources: None. Sarcoidosis can affect not only the lungs, but also the heart, particularly, the right ventricle (RV), by both primary (5-25% of patients) or secondary mechanism due to PH. People of young, working age are at higher risk. Purpose to study global longitudinal strain (GLS), RV ejection fraction in 3D mode (EF-3D), TAPSE and S", pulmonary artery systolic pressure (SPAP) at rest and at peak of exercise in patients with sarcoidosis and to determine the role of these parameters in diagnostic algorithm. Methods. The main group consisted of 66 patients with histologically confirmed stage I-II pulmonary sarcoidosis: 42 men (63.6%) and 24 women (36.4%); mean aged 31.9 ± 5.59 years. The control group included 33 healthy, nonsmoking people: 24 men (72.7%) and 9 women (27.3%); mean aged 30.18 ± 5.3 years. Results. There were no deviations from the normal values of S’and TAPSE at rest, as well as at rest at the peak of exercise in both groups (p&amp;gt; 0.05). EF-3D RV was within the normal values and didn’t differ significantly at rest and at the peak of exercise (p &amp;gt; 0.05). RV GLS in both groups at rest and at the peak of exercise, were also normal. RV GLS in patients with sarcoidosis during exercise didn"t increase, but decreased (p = 0.004): from -22.8 ± 3.4% at rest to -21.2 ± 4.7% at the peak of exercise, by 7% (in control group: -24.1 ± 2.7 to -25.1 ± 3, p = 0.002). Values of SPAP at rest in patients with sarcoidosis was slightly higher than in healthy individuals (28.5 ± 8.3 and 24.8 ± 5.21 mm Hg; p = 0.03), in normal ranges. At the peak of exercise SPAP in patients with sarcoidosis increased greater than in the control group (32.9 ± 10.1 and 48.36 ± 14.4 mm Hg; p = 0.000001). In the control group at rest, the upper quartile of the SPAP was 29 mm Hg, at the peak of exercise - 38 mm Hg. In the main group, these indicators were significantly higher: 35 and 62 mm Hg. In the main group, at the peak of exercise, the SPAP value exceeded the upper quartile of the control group (38 mm Hg) in 79% of cases. These data may indicate the presence of subclinical pulmonary hypertension in the main group. To determine the border of normal and pathology in study groups, the threshold values of the RV GLS were obtained at the peak of exercise by the method of constructing classification trees. For RV GLS at the peak of exercise, this value turned out to be -21.6%. This means that when RV GLS is less than -21.6% in young patients with pulmonary sarcoidosis, the likelihood of subclinical RV dysfunction is 90%. In combination with an increase in SPAP at the peak of exercise more than 39.5 mm Hg these patients have an even higher rank of the significance of RV dysfunction, namely 100%. So, we propose to complete the diagnostic algorithm in patients with pulmonary sarcoidosis by RV GLS SPAP at the peak of exercise for defining the early RV systolic disfunction.

Relationship between oxidative stress and three-dimensional echocardiographic changes in myxomatous mitral valves with severe regurgitation - a pilot study

Abstract Funding Acknowledgements Type of funding sources: None. Background. Reactive oxygen species (ROS) have been reported to contribute to the molecular pathogenesis of severe mitral regurgitation induced by myxomatous degeneration. Data about oxidative stress and the possible relationship with the extent of prolapsing and/or flail elements is scarce in the literature. The pathogenic mechanism may prompt the development of therapeutic approaches aimed at delaying extensive valvular alteration. Purpose. The aim of the study is to investigate the possible correlation between ROS expression in myxomatous mitral valves with severe regurgitation and the extent of valvular alteration. Material and methods. Samples from myxomatous mitral valves with ruptured chordae and severe regurgitation were harvested during surgical intervention for valve repair/replacement from 9 patients. Besides transthoracic echocardiography, all patients were evaluated before surgery by transesophageal echocardiography (TEE) with three-dimensional (3D) reconstruction of the mitral valve, using 3D zoom mode acquisition with qualitative and quantitative analysis through the 4D Auto MVQ technology. Tissue from the valvular samples was further analysed for the assessment of ROS by 2 methods: spectrophotometry (ferrous oxidation xylenol orange - FOX assay) and confocal microscopy (dihydroethidium staining). Results. Patients had a mean age of 51.88 ± 13.54 years, with a left ventricular ejection fraction of 62.55 ± 7.33%, left ventricular end-diastolic diameter of 5.4 ± 0.72cm and end-diastolic volume of 168.55 ± 62.57ml, a mitral annulus area of 17.91 ± 5.74 cm2 and a number of prolapsing/flail scallops varying between 1 and 5 (average of 2 ± 1 scallops). All patients had diffuse thickening of the mitral leaflets with at least one primary and one secondary ruptured chordae and flail of the P2 scallop. Two patients had significant prolapse of at least 2 anterior mitral leaflet scallops and three patients had supplemental significant prolapse and/or flail of at least 1 posterior scallop, besides flail of P2. The mean value for ROS in the valvular tissue was 9.46 ± 2.03nM H2O2/mg tissue/h at FOX assay. A significant positive correlation between the ROS values and the extent of prolapsing/flail segments was found (R = 0.67, p = 0.04). Conclusion. Besides the diagnosis and accurate preoperatory valve description, 3D TEE along with molecular investigations contribute to the understanding of myxomatous mitral valves’ pathogenesis. Oxidative stress increased in the mitral valves with advanced myxomatous degeneration. Whether this occurs as a cause or a consequence contributing to the disease progression as well as the sources of ROS are worth further investigation.

Study of the Immediate Effects of Autostereoscopic 3D Visual Training on the Accommodative Functions of Myopes.

PurposeStereoscopic viewing has an impact on ocular dynamics, but its effects on accommodative functions are not fully understood, especially for autostereoscopic viewing. This study aimed to investigate the changes in dynamic accommodative response, accommodative amplitude, and accommodative facility of myopes after autostereoscopic visual training.MethodsWe enrolled 46 adults (men = 22 and women = 24; age = 21.5 ± 2.5 [range = 18–25] years, spherical equivalent: −4.52 ± 1.89 [−8.88 to −1.75] diopters [D]) who visited the Eye & ENT Hospital of Fudan University. The study population was randomly divided into three-dimensional (3D) and two-dimensional (2D) viewing groups to watch an 11-minute training video displayed in 3D or 2D mode. Dynamic accommodative response, accommodative facility, and accommodative amplitude were measured before, during, and immediately after the training. Accommodative lag and the variability of accommodation were also analyzed. Visual fatigue was evaluated subjectively using a questionnaire.ResultsAccommodative lag decreased from 0.54 ± 0.29 D to 0.42 ± 0.32 D (P = 0.004), whereas accommodative facility increased from 10.83 ± 4.55 cycles per minute (cpm) to 13.15 ± 5.25 cpm (P < 0.001) in the 3D group. In the 2D group, there was no significant change in the accommodative lag (P = 0.163) or facility (P = 0.975), but a decrease in accommodative amplitude was observed (from 13.88 ± 3.17 D to 12.71 ± 2.23 D, P = 0.013). In the 3D group, the accommodative response changed with the simulated target distance. Visual fatigue was relatively mild in both groups.ConclusionsThe immediate impact of autostereoscopic training included a decrease in the accommodative lag and an increase in the accommodative facility. However, the long-term effects of autostereoscopic training require further exploration.

Optimization of 3D Printing Modes for Electric Arc Surfacing Using a Digital Twin of the Process

The article proposes a method for choosing the optimal modes of 3D printing by electric arc surfacing on CNC machines using a digital twin of the process. As a digital twin, a neural network model is used that approximates the dependence of the stability of the surfacing process and the geometric parameters of the printed layer on the surfacing modes: voltage, current and minute feed. The possibility of optimizing 3D printing modes using neural network modeling based on a modified backpropagation method is shown.