Miracle-dz/UniFAR-FTUs huggingface dataset:
Toward anisotropic mesh construction and error estimation in the finite element method

Directional, anisotropic features like layers in the solution of partial differential equations can be resolved favorably by using anisotropic finite element meshes. An adaptive algorithm for such meshes includes the ingredients Error estimation and Information extraction/Mesh refinement. Related articles on a posteriori error estimation on anisotropic meshes revealed that reliable error estimation requires an anisotropic mesh that is aligned with the anisotropic solution. To obtain anisotropic meshes the so‐called Hessian strategy is used, which provides information such as the stretching direction and stretching ratio of the anisotropic elements. This article combines the analysis of anisotropic information extraction/mesh refinement and error estimation (for several estimators). It shows that the Hessian strategy leads to well‐aligned anisotropic meshes and, consequently, reliable error estimation. The underlying heuristic assumptions are given in a stringent yet general form. Numerical examples strengthen the exposition. Hence the analysis provides further insight into a particular aspect of anisotropic error estimation. © 2002 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 18: 625–648, 2002; DOI 10.1002/num.10023
An Investigation on Noisy Environments in Evolutionary Multi-Objective Optimization

In addition to the need of satisfying several competing objectives, many real-world applications are also characterized by a certain degree of noise, manifesting itself in the form of signal distortion or uncertain information. While studies have shown that many multi-objective evolutionary optimizers are capable of achieving optimization goals, their ability to deal with noise is rarely studied. In this paper, extensive studies are carried out to examine the impact of noisy environments in evolutionary multi-objective optimization based upon five benchmark problems characterized by different difficulties in local optimality, non-uniformity, discontinuity and non-convexity. Interestingly, the baseline algorithm employed tends to evolve better solution sets in the presence of low noise levels for some problems. Nevertheless, the evolutionary optimization process degenerates into random search under increasing noise levels
XUV spectra of the 1973 June 15 solar flare observed from Skylab. III - A list of spectral lines from 1000 to 1940 A

A wavelength list of spectral lines between 1000 and 1940 A is presented for the solar flare that occurred on June 15, 1973. The spectra were recorded by the NRL spectrograph on Skylab. The spectral resolution is 0.06 A. Intensities, identifications, and estimates of line widths are given. The intensity of the continuum is also given at 50-A intervals between 1400 and 1900 A. The wavelength list includes about 1400 lines; about 30% of these lines are not indentified. Because of the high wavelength resolution, this line list will be useful as a source of identification for some stellar as well as solar spectra. In particular, the list should be a useful aid in the identification of lines in the spectra of stars with classifications close to that of the sun. Spectra of such stars may be obtained from the recently launched IUE spacecraft. It is also interesting to compare the list with some of the spectra of early-type stars recorded by Copernicus.
A Comparison of Three Different Modeling Strategies for Evaluating Cloud and Radiation Parameterizations

Abstract Parallel simulations of clouds and radiation fields by a single-column model (SCM), a regional circulation model, and a global circulation model (GCM), each using the same treatment of all physical processes and approximately the same spatial resolution, are compared with observations at the Atmopheric Radiation Measurement Clouds and Radiation Testbed in the southern Great Plains. Significant differences between model simulations are evident for individual cloud systems, but these differences are not systematic, varying from cloud system to cloud system. Several systematic differences between model simulations and observations are identified. These biases are about the same for each model and are much larger than differences between model simulations, suggesting that for some purposes one model can serve as a testbed for parameterizations developed for another. The role of nudging in the simulations is explored by driving the SCM with large-scale forcing from a GCM simulation. The authors find t.
Learning and Study Strategies of Students in the First Year of an Entry-Level Physical Therapist Program

Introduction. The learning and study strategies of entry-level physical therapist (PT) students may not be as effective as those needed for success in an entry-level PT education program. The Learning and Study Strategies Inventory, third edition (LASSI) is a reliable tool to assess learning and study strategies. The purpose of this study was to assess the learning and study strategies of first-year PT students and if the strategies change over the first year. Review of Literature. There is little research on using the LASSI with PT students; however, the LASSI has been used with other health care professional students. Subjects. The participants (n = 211) were from 5 cohorts of PT students in their first year of an entry-level PT education program. Methods. In the first week of the curriculum the students took the LASSI in class. The results were released individually to each student. No intervention was provided. At the end of the first year, the students retook the LASSI. Paired samples t-tests were run to determine whether the 10 subtest mean percentile scores changed significantly from baseline to follow-up and how they compared to established LASSI benchmarks. Results. Six subtest scores, Anxiety, Attitude, Concentration, Information Processing, Selecting Main Ideas, and Test Strategies, showed significant changes (P ≤ .005) from baseline to follow-up. However, all subtest averages fell below the 75th percentile mark, which is reported as the threshold requiring reflection to improve skills for learning and study strategies. Discussion and Conclusion. Students, on average, may not have adequate learning and study strategies when they start an entry-level PT education program. The LASSI may be an effective tool to focus resources in a timely and proactive manner for those students who may need them. Determining the resources needed earlier may decrease the need for later remediation, attrition, or licensure examination failures.
The dimension of attractors underlying periodic turbulent Poiseuille flow

Using a coarse grained (16 × 33 × 8) numerical simulation, a lower bound on the Lyapunov dimension, Dλ, of the attractor underlying turbulent, periodic Poiseuille flow at a pressure-gradient Reynolds number of 3200 has been calculated to be approximately 352. These results were obtained on a spatial domain with streamwise and spanwise periods of 1. 6π, and correspond to a wall-unit Reynolds number of 80. Comparison of Lyapunov exponent spectra from this and a higher-resolution (16 × 33 × 16) simulation on the same domain shows these spectra to have a universal shape when properly scaled. Using these scaling properties, and a partial exponent spectrum from a still higher-resolution (32 × 33 × 32) simulation, we argue that the actual dimension of the attractor underlying motion on the given computational domain is approximately 780. The medium resolution calculation establishes this dimension as a strong lower bound on this computational domain, while the partial exponent spectrum calculated at highest resolution provides some evidence that the attractor dimension in fully resolved turbulence is unlikely to be substantially larger. These calculations suggest that this periodic turbulent shear flow is deterministic chaos, and that a strange attractor does underly solutions to the Navier–Stokes equations in such flows. However, the magnitude of the dimension measured invalidates any notion that the global dynamics of such turbulence can be attributed to the interaction of a few degrees of freedom. Dynamical systems theory has provided the first measurement of the complexity of fully developed turbulence; the answer has been found to be dauntingly high.
Hybrid Silicon Nanocrystal/Poly(3-hexylthiophene-2,5-diyl) Solar Cells from a Chlorinated Silicon Precursor

Freestanding silicon nanocrystals (Si NCs) synthesized by a nonthermal plasma from silicon tetrachloride (SiCl4) were successfully employed in hybrid Si NC/poly(3-hexylthiophene-2,5-diyl) (P3HT) bulk-hetrojunction (BHJ) solar cells. The weight fraction of Si NCs in P3HT greatly influences device performance. As the weight fraction increases up to 50 wt %, short-circuit current dramatically increases, while open-circuit voltage (Voc) and fill factor (FF) do not change significantly. The improvement in device performance is attributed to both increased probability of exciton dissociation in P3HT and an enhancement in the light conversion of wavelengths where P3HT is a poor absorber. These results demonstrate an alternative approach to synthesizing Si NCs from SiCl4 instead of silane (SiH4) for optoelectronic devices.
Investigation Between Recover Behavior and Defect With Variation of Light Source in AlGaN/GaN HEMTs After Hot-Carrier Stress

In this letter, a light recovery method is proposed to analyze defect concentration and energy level distribution by changing the wavelength. The AlGaN/GaN high electron mobility transistors (HEMTs) under hot carrier stress (HCS) conditions will experience a severe electrical degradation. The threshold voltage ( ${V}_{\textit {th}}$ ) shifts to the right, and the on current and the off current both decrease. TCAD simulations of the electric field distribution and energy bands are performed to examine the degradation behaviors under HCS on the GaN-based HEMTs. The degradation of electrical characteristics can be effectively recovered by using the illumination method in AlGaN/GaN HEMTs. In addition, the light wavelength of illumination is positively correlated with the recovery effect, which is expected to provide effective measurements and analyses for AlGaN/GaN HEMT devices, which is expected to clarify the defect energy level distribution of HEMT device degradation.
DYNAMIC CHARACTERISTICS OF PARTIAL COMPOSITE BEAMS

This paper is concerned with the dynamic characteristics of composite beams with partial shear connections. The governing equations of motion for partial composite beams are derived from the one-dimensional partial composite beam theory. By solving the corresponding characteristic equation, the natural frequencies and modal shapes for simple partial composite beams are obtained. The orthogonality condition between the natural modes is utilized to decouple the equations of motion. Closed-form solution for the simple partial composite beam subjected to a moving load is derived by the modal superposition method. Key parameters that govern the fundamental frequency and deflection impact factor of simple partial composite beams are identified. Numerical results show that the former is controlled by the composite connection and section combination parameters, and the latter by the fundamental frequency ratio. It was observed that the time-history response of a partial composite beam may differ significantly from that of a full composite beam in terms of amplitude, period, and overall shape, depending on the composition connection.
Cross‐tail magnetic flux ropes as observed by the GEOTAIL spacecraft

Ten transient magnetic structures in Earth's magnetotail, as observed in GEOTAIL measurements, selected for early 1993 [at (−) XGSM = 90 - 130 RE], are shown to have helical magnetic field configurations similar to those of interplanetary magnetic clouds at 1 AU but smaller in size by a factor of ≈ 700. Such structures are shown to be well approximated by a comprehensive magnetic force-free flux-rope model. For this limited set of 10 events the rope axes are seen to be typically aligned with the YGSM axis and the average diameter of these structures is ≈ 15 RE.
Monitoring of radiofrequency thermal ablation in liver tissue through fibre Bragg grating sensors array

A fibre Bragg grating (FBG) array-based sensing probe has been installed on a device for radiofrequency thermal ablation (RFTA). The probe is made of five FBGs with 0.5 cm active area and 1 cm spacing, to provide quasi-distributed thermal pattern measurements. Multiple experiments have been conducted on porcine liver, reporting the temperature pattern along the ablation axis. Thermal maps allow an estimation of the RFTA efficiency and spatial extension in the liver.
Domain-product technique solution for the problem of electromagnetic scattering from multiangular composite cylinders

The paper presents a domain-product technique solution for the problem of electromagnetic scattering from a two-dimensional structure composed of multiple perfect conductors and lossless dielectrics with arbitrarily polyhedral boundaries. The configuration is assumed to be excited by a plane wave polarized transverse magnetic or transverse electric to the axis of the cylinders. For both the interior and exterior subregions, efficient field representations are attained in the forms of Mathieu function expansions. A system of infinite matrix equations with respect to the expansion coefficients results from the boundary conditions. A solution to the system is found using a truncation procedure. Numerical examples are presented that demonstrate the validity, flexibility, and capability of the technique. In the middle frequency range, the approach proposed enables accurate numerical analysis of fairly complicated structures with low computational cost.
Analysis of Spur Gears by Coupling Finite and Boundary Element Methods

Abstract Stress and deflection analysis of spur gears are presented by coupling finite and boundary element methods. Single-tooth, three-teeth, and whole-body spur gear models are solved using finite element methods in ANSYS (a finite element package). In addition to these models, two different whole-body models are developed using a coupling program written in Fortran 95. Keyway effects are included in the whole-body and coupling models. In each model, the stresses along the critical sections and deflections of midline of loaded tooth are investigated under the action of driving force. The variations of stresses and deflections are also represented at the critical points when the driving force application point is changing between tip and pitch. The effect of keyway position on stress and deflections is also presented. The results are compared with each other and ANSYS.
Investigation of the subgrid-scale fluxes and their production rates in a convective atmospheric surface layer using measurement data

The subgrid-scale (SGS) potential temperature flux and stress in the atmospheric surface layer are studied using field measurement data. We analyse the mean values of the SGS temperature flux, the SGS temperature flux production rate, the SGS temperature variance production rate, the SGS stress and the SGS stress production rate conditional on both the resolvable-scale velocity and temperature, which must be reproduced by SGS models for large-eddy simulation to reproduce the one-point resolvable-scale velocity–temperature joint probability density function (JPDF). The results show that the conditional statistics generally depend on the resolvable-scale velocity and temperature fluctuations, indicating that these conditional variables have strong influences on the resolvable-scale statistics. The dependencies of the conditional SGS stress and the SGS stress production rate, which are partly due to the effects of flow history and buoyancy, suggest that model predictions of the SGS stress also affect the resolvable-scale temperature statistics. The results for the conditional flux and the conditional flux production rate vectors have similar trends. These conditional vectors are also well aligned. The positive temperature fluctuations associated with updrafts are found to have a qualitatively different influence on the conditional statistics than the negative temperature fluctuations associated with downdrafts. The conditional temperature flux and the temperature flux production rate predicted using several SGS models are compared with measurements in statistical a priori tests. The predictions using the nonlinear model are found to be closely related to the predictions using the Smagorinsky model. Several potential effects of the SGS model deficiencies on the resolvable-scale statistics, such as the overprediction of the vertical mean temperature gradient and the underprediction of the vertical temperature flux, are identified. The results suggest that efforts to improve the LES prediction of a resolvable-scale statistic must consider all the relevant SGS components identified using the JPDF equation and the surface layer dynamics. This study also provides impetus for further investigations of the JPDF equation, especially analytical studies on the relationship between the JPDF and the SGS terms that govern its evolution.
Variable Resistance—An Efficient Method to Generate Muscle Potentiation: A Systematic Review and Meta-Analysis

Variable resistance (VR) is a methodology that has shown good results in developing muscular strength and power. However, no updated information relates to the use of VR as an activation to trigger post-activation performance enhancement (PAPE). The primary objective of this systematic review and meta-analysis was to review and qualitatively describe studies published between 2012 and 2022 that used VR to generate PAPE in muscle power-dominant sports. The secondary objective was to calculate the effect size of the different power outcomes reported in the selected studies. The search was designed following the PRISMA® guidelines for systematic reviews and meta-analyses and performed in the Web of Science (WOS), Scopus, SPORTDiscus, PubMed, and MEDLINE between 2012 and 2022. The methodological quality and risk of bias were evaluated with the Cochrane Collaboration tool. The main variables were the throwing speed, time in sprint tests, and jump height. The analysis was conducted with a pooled standardized mean difference (SMD) through a Hedges’ g test (95% CI). Twenty-two studies were included in the systematic review and ten in the meta-analysis, revealing a trivial effect for throwing speed (SMD = 0.06; CI = 95%: −0.23–0.35; p = 0.69), a small effect for the time in sprint tests (SMD = −0.37; CI = 95%: −0.72–−0.02; p = 0.04), and a moderate effect for jump height (SMD = 0.55; CI = 95%: 0.29–0.81; p ˂ 0.0001). All forms of VR used for neuromuscular activation effectively triggered PAPE. Specifically, the results showed that activation with VR generates performance increases in time, in sprint tests and jump height, and a trivial effect in throwing tests (speed and distance).
Asymptotical well behaviour for constrained minimisation problems

This paper is devoted to the study of the links between stationary sequence and minimising sequence for constrained minimisation problems. The constraint set is not supposed to be convex and no differentiability assumption is made on the objective function. New tools are developed in this general framework and we prove a necessary and a sufficient condition for such problems to have a “constrained asymptotical well behaviour” (that is, each stationary sequence is a minimising sequence). Our work extend that of Auslender, Cominetti and Crouzeix.
Computerization of Paper-and-Pencil Tests: When are They Equivalent?

The cross-mode equivalence of paper-and-pencil (P&P) and computer-based clerical tests was examined. 411 undergraduate students at two large Midwestern universities were administered 10 timed clerical tests. Although Mead & Drasgow's (1993) meta-analysis found that speededness moderated cross-mode equivalence, the current study found no differences across modes between P&P tests and computer-based tests (CBTs). When speeded CBTs follow the same administration and response procedures as the P&P format, differences across modes can be minimized. Equivalence is discussed at three levels: parallel, r-equivalent, and congeneric. The statistical and practical implications of test equivalence are presented. Although structural equation modeling determined the tests to be congeneric, results showed only small distributional differences cross-modally. No differential validity across formats was found.
Breaking Waves in Deep and Intermediate Waters

Since time immemorial, surface water waves and their subsequent breaking have been studied. Herein we concentrate on breaking surface waves in deep and intermediate water depths. Progress has been made in several areas, including the prediction of their geometry, breaking onset, and especially energy dissipation. Recent progress in the study of geometric properties has evolved such that we can identify possible connections between crest geometry and energy dissipation and its rate. Onset prediction based on the local wave-energy growth rate appears robust, consistent with experiments, although the application of criteria in phase-resolving, deterministic prediction may be limited as calculation of the diagnostic parameter is nontrivial. Parameterization of the dissipation rate has benefited greatly from synergistic field and laboratory investigations, and relationships among the dynamics, kinematics, and the parameterization of the dynamics using geometric properties are now available. Field efforts continue, and although progress has been made, consensus among researchers is limited, in part because of the relatively few studies. Although direct numerical simulations of breaking waves are not yet a viable option, simpler models (e.g., implementation of an eddy viscosity model) have yielded positive results, particularly with regard to energy dissipation.
Theory of sounds in He II

A dynamical model for Landau’s original approach to superfluid helium is presented, with two velocities but only one mass density. The second sound is an adiabatic perturbation that involves the temperature and the roton, aka the notoph. The action incorporates all the conservation laws, including the equation of continuity. With only 4 canonical variables it has a higher power of prediction than Landau’s later, more complicated model, with its 8 degrees of freedom. The roton is identified with the massless notoph. This theory gives a very satisfactory account of second and fourth sounds. Second sound is an adiabatic oscillation of the temperature and both vector fields, with no net material motion. Fourth sound involves the roton, the temperature, and the density. With the experimental confirmation of gravitational waves, the relations between Hydrodynamics and Relativity and particle physics have become more clear, and urgent. The appearance of the Newtonian potential in irrotational hydrodynamics comes directly from Einstein’s equations for the metric. The density factor ρ is essential; it is time to acknowledge the role that it plays in particle theory. To complete the 2-vector theory we include the massless roton mode. Although this mode too is affected by the mass density, it turns out that the wave function of the unique notoph propagating mode N satisfies the normal massless wave equation [Formula: see text]; the roton propagates as a free particle in the bulk of the superfluid without meeting resistance. In this circumstance, we may have discovered the mechanism that lies behind the flow of He II through very thin pores.