Miracle-dz/UniFAR-FTUs huggingface dataset:
Change of ultra-short laser pulse shape after scattering by a nanosphere in a dielectric matrix

The scattering of ultra-short laser pulses by a metallic nanosphere embedded in a dielectric matrix was studied theoretically in the frame of the dipole approximation. Calculations were performed for the corrected Gaussian shape of the incident laser pulse, which enabled us to consider both multi-cycle and sub-cycle pulses. Analysis of the influence of the scattering process on the shape of scattered pulse is made for various durations and carrier frequencies of the incident pulses.
Direct Approach to Construct the Periodic Wave Solutions for Two Nonlinear Evolution Equations

With symbolic computation, the Hirota method and Riemann theta function are employed to directly construct the periodic wave solutions for the Hirota–Satsuma equation for shallow water waves and Boiti–Leon–Manna–Pempinelli equation. Then, the corresponding figures of the periodic wave solutions are given. Furthermore, it is shown that the known soliton solutions can be reduced from the periodic wave solutions.
A Smooth Wave‐Form Shaped Command with Flexible Maneuvering Time: Analysis and Experiments

Shaped commands are used to eliminate residual oscillations of crane payloads. Command jerks are detrimental to the safe and efficient operation of cranes. Smooth shaped commands are recommended to avoid such jerks in motion commands to crane motors. The amplitude of the shaped command is governed by its time length. The time length of the shaped command is highly dependent on the natural period of oscillation of the payload. A flexible time length of the shaped command introduces flexibility in selecting the desired command amplitude that would lead to a reduced stress on the crane actuators. In this work, a smooth wave‐form acceleration command is proposed to eliminate residual oscillations in rest‐to‐rest maneuvers of cranes. The proposed shaped command is derived analytically. The system performance is simulated numerically and validated experimentally on a scaled model of an overhead crane. The proposed wave‐form is further modified to relax the dependence of the profile on the natural period of oscillation of the payload.
Stellarator optimization studies in W7-AS

Wendelstein 7-AS is the first large-scale modular stellarator, partially optimized with respect to reduced equilibrium currents . It therefore plays an important role for the optimized next step stellarator W7-X as a pilot experiment for manufacturing techniques of coils and vessel and for equilibrium and neo-classical transport properties of the Wendelstein stellarator line of IPP. Experimental results from W7-AS of importance for the continuation and optimization of the advanced stellarators are summarized: with respect to magnetic optimization we address improved equilibrium, stability and neo-classical transport and the feasibility of the modular coil system. Regarding operational enhancements we focus on demonstrated high-density operation and the soft edge density limit, improved confinement, verification of the 3D plasma edge topology, stability of island structures for exhaust properties and demonstrated stable divertor high recycling in the island divertor configuration.
Adiabatic compression of elongated field‐reversed configurations

The adiabatic compression of an elongated field‐reversed configuration (FRC) is computed by using a one‐dimensional approximation. The one‐dimensional results are checked against a two‐dimensional equilibrium code. For ratios of FRC separatrix length to separatrix radius greater than about ten, the one‐dimensional results are accurate within 10%. To this accuracy, the adiabatic compression of FRC’s can be described by simple analytic formulas.
The Error Caused by Relativity in GPS Positioning System

In GPS Positioning System, distance measurement between the receiver and the satellite is affected by all kinds of factors. So it has errors. Some of these errors, which are caused by relativity can’t be neglected when it is being accurate positioned. This essay analyses and estimates these errors. Key words: GPS; Positioning; Measurement; Error Special; Theory of Relativity; General; Theory of Relativity
Measurements of some parameters of bowing

The maximum bow force for Helmholtz oscillations, and the frequency shift as a function of bow force, have been measured for unstopped notes on a variety of violin strings. A bowing machine is briefly described on which data using bowing velocities at 5 and 10 cm/s were obtained. Computer simulations using the standard friction function model of the bowed string were also done. The combination of the measurements and the simulations allow an assessment of the probable validity of the friction curve model of the force between bow hair and string in bowed string motion.
A Movement-Artefact-Free Heart-Rate Prediction System

Continuous automatic heart rate (HR) monitoring plays a crucial role in timely intervention for postoperative patients. However, for effective alarm management, patients' activities of daily living need to be considered as they influence HR. This explorative study aimed to develop a heartrate prediction system while performing six activities. An experiment with fourteen participants was conducted to gather data to build a system. This system consisted of a support-vector machine classifier for activity recognition and a k-Nearest Neighbors regressor for HR prediction. The R-squared (a goodness-of-fit measure) of the HR predictor is 79% on average. Given the heterogeneity of different populations, the system will be further tested and developed using patient datasets in future towards clinicalpractice applications.
Electrostrictive effect in lead-free relaxor K0.5Na0.5NbO3–SrTiO3 ceramic system

The elastic strain of lead-free relaxor K0.5Na0. 5NbO3–SrTiO3 ceramic system, induced by applied electric fields with amplitudes up to 40kV∕cm, has been investigated. The strain response, being similarly low (order of 10−5) as in the classical lead magnesium niobate relaxor, is shown to be of solely electrostrictive origin, as a pure quadratic relation holds between induced strain and electric polarization. The strain dependence on the SrTiO3 content is presented and discussed. Furthermore, electrostrictive coefficients are shown to be constant over a broad temperature range and, similar to dielectric properties, independent of electric-field cycles, which suggests possible applications of this translucent, high-dielectric constant, and environmental-friendly ceramic system.
Unsteady flows in a capillary lined with a thin porous surface layer by method of fundamental solutions

This paper studies unsteady viscous flows in a capillary using the method of fundamental solutions. The effect on fluid velocity of a thin porous surface layer on the wall of the tube is modelled using a slip boundary condition. Laplace transform is used to handle the time variables in the problem. Fundamental solutions of point force in the transformed domain and in the time domain are derived. This study extends our previous work by developing a sophisticated boundary singularity scheme based on the Method of Fundamental Solution (MFS).
Algorithm of ICA-based poisson-noise reduction and its application to CT imaging

CT (computed tomography) imaging is a technology which uses X-ray beams (radiation) and computers to form detailed, cross-sectional images of an area of anatomy. However, the random scattered X-ray in CT imaging system will reduce radiographic contrast greatly in CT images. In this paper, a four-step method is proposed for decoding CT images: first, the EGSnrc Monte Carlo simulation system is used to simulate CT imaging and simulated data will be validated by real experimental data in the same experimental conditions; second, scattered X-ray image simulated by EGSnrc will be transformed into ICA-domain (independent component analysis-domain) to obtain the main magnitude of scattering data; third, a noise-reduction algorithm based on ICA-domain shrinkage is applied to smooth the CT image; fourth, the conventional linear deconvolution follows. The simulation results show that the reconstructed image is dramatically improved in comparison to that without the noise-removing filters, and the proposed method is also applied to real experimental X-ray imaging.
Fokker–Planck model for nonlocal impact ionization in semiconductors

The probability distribution function (PDF) for impact ionization path length is a crucial quantity for understanding and modeling the low noise behavior of avalanche photodiodes with short multiplication regions. In such devices the ionization coefficient is no longer in equilibrium with the local electric field but depends on the carrier’s history. The high electric fields needed to produce avalanche gain narrow the PDF, thereby reducing the randomness in ionization position and hence the noise in the multiplication. In this article we present a method for calculating PDFs using a Fokker–Planck model. The results are compared with those obtained from an equivalent Monte Carlo simulation employing a parabolic energy band, deformation potential optical phonon scattering, and a hard energy threshold for impact ionization.
Real‐time computation of feedback controls for constrained optimal control problems. part 1: Neighbouring extremals

A numerical method is developed for the real-time computation of neighbouring optimal feedback controls for constrained optimal control problems. The first part of this paper presents the theory of neighbouring extremals. Besides a survey of the theory of neighbouring extremals, special emphasis is laid on the inclusion of complex constraints, e.g. state and control variable inequality constraints and discontinuities of the system equations at interior points. The numerical treatment of these constraints is particularly emphasized. The linearization of all necessary conditions of optimal control theory leads to a linear, mulitpoint, boundary value problem with linear jump conditions that is especially well suited for numerical treatment.
Vibrational excitation of N2 by resonance scattering of electrons

The vibrational excitation of N2 molecules by resonance scattering of electrons of 2-3 eV is calculated with a compound state model, that is on the assumption that the mechanism is e+N2 to N2- to N2+e'. The complex electronic energy of the N2- ion is treated parametrically, the essential new point being that Gamma /h(cross), the autoionization rate, varies with the separation of the nuclei. The variation comes from the dependence of the angular momentum barrier on the energy of the emitted electron. Good agreement is obtained with the experimental energy dependence of cross sections with reasonable values of the parameters. Calculations have also been done to illustrate the transition to the impulse limit as Gamma is increased, and to the compound molecule limit as Gamma is reduced.
On the Importance of Clinical Notes in Multi-modal Learning for EHR Data

Understanding deep learning model behavior is critical to accepting machine learning-based decision support systems in the medical community. Previous research has shown that jointly using clinical notes with electronic health record (EHR) data improved predictive performance for patient monitoring in the intensive care unit (ICU). In this work, we explore the underlying reasons for these improvements. While relying on a basic attention-based model to allow for interpretability, we first confirm that performance significantly improves over state-of-the-art EHR data models when combining EHR data and clinical notes. We then provide an analysis showing improvements arise almost exclusively from a subset of notes containing broader context on patient state rather than clinician notes. We believe such findings highlight deep learning models for EHR data to be more limited by partially-descriptive data than by modeling choice, motivating a more data-centric approach in the field.
A Holographic Approach to the Black Hole Information Paradox

This dissertation focuses on how recent developments in holography could be applied to the black hole evaporation process, to get closer to resolving the black hole information paradox. We begin by presenting some of the required background on Hawking radiation and the AdS/CFT correspondence, before focusing on the quantum extremal surfaces prescription for holographic entanglement entropy. We show how quantum extremal surfaces and islands recover the Page curve and show that this description of the system is consistent with unitarity, as well as how this description suggests information might be conserved.
A direct calculation of the tunnelling current. II. Free electron description

For Pt. I see ibid., vol.4. , 916 (1971). The theory of tunnelling introduced in Pt. I is reformulated in the case of free electrons subjected to an arbitrary one-electron potential. An exact expression for the current is obtained, using Keldysh's generalization of perturbation theory. This result is particularly suited to an exact field theoretical treatment of many-body effects in the tunnelling junction.
Control of a novel fractional hyperchaotic system using a located control method

Fractional order dynamics and chaotics systems have been recently combined, yielding interesting behaviours. In this paper, a novel integer order hyperchaotic system is considered. Then, a fractional order hyperchaotic representation of said system is proposed using a natural fractionalization. Two different linear control methodologies to deal with the complexity which introduce such systems are proposed. Those methods are able to modify the hyperchaotic behaviour of the system and force it to move towards a fixed point; i.e. steady state. These approaches give a general framework for taming such complex systems using simple linear controllers. The main tools for analysing the controlled system are Matignon stability criterion and RouthHurwitz test. Using a reliable numerical simulation, the designed system is simulated to verify the theoretical analysis.
Ram pressure stripping from elliptical galaxies. I: The mass contained in the galaxy

We examine the physical assumptions and the basic hydrodynamic equations of the ram pressure stripping model for elliptical galaxies in clusters of galaxies. Our equations differ from those of Gaetz, Salpeter, and Shaviv in the treatment of the motion of stars in the galaxy. We solved the model equations numerically in two dimensions and extended the range of parameters beyond the range assumed by Gaetz et al. We find the following: 1. The formation of a bow shock in a cluster galaxy is due to the replenished gas from stellar mass loss. A typical galaxy without replenishment moving through the cluster gas does not form a shock. 2. The velocity dispersion of the stars in the galaxy has a large influence on the injection temperature of the replenished gas
Large eddy simulation of magnetohydrodynamic turbulent channel flows under a uniform magnetic field

Magnetohydrodynamic turbulent channel flows under a uniform magnetic field are studied by using a large eddy simulation technique. The effect of a uniform magnetic field is incorporated into the subgrid‐scale model in the form of a local damping factor. Compared with the experiment, this model is shown to work better than the usual Smagorinsky model in both turbulent and laminar states. This model predicts the detailed structures of the present flows, for which, one‐point global turbulence models of ensemble mean type are helpless.
Daily generation scheduling optimization with transmission constraints: a new class of algorithms

The authors describe a novel class of algorithm dealing with the daily generation scheduling (DGS) problem. These algorithms have been designed by adding artificial constraints to the original optimization problem; handling these artificial constraints by using a dual approach; using an augmented Lagrangian technique rather than a standard Lagrangian relaxation technique; and applying the auxiliary problem principle which can cope with the nonseparable terms introduced by the augmented Lagrangian. To deal with the DGS optimization problem these algorithms are shown to be more effective than classical ones. They are well suited to solve this DGS problem taking into account transmission constraints. >
Study of water entry of circular cylinder by using analytical and numerical solutions

Water impact phenomenon in the case of a circular cylinder is an important issue in offshore industry where cross members may be in the splash zone of the incident wave. An analytical method as well as a numerical solution are employed to study the water entry problem of a circular section. The procedure for derivation of the analytical formulas is demonstrated step by step. The volume of fluid (VOF) simulation of the water entry problem is also performed to offer comparison of the results of the linearized analytical solution with a fully nonlinear and viscous fluid flow solution. To achieve this, the FLOW-3D code is utilized. Some consideration has also been given to the points of intersection of the free surface and the body, where the singularities exist in the free surface deformation and velocities, as predicted by the linear theory. These singularities appear to be avoided in the real fluid by the formation of jets which quickly break up into sprays under the action of surface tension. Slamming force, free surface profile, impact force, pressure distribution and evolution of intersection points are also presented and comparisons of the obtained results against the results of previous studies illustrate favorable agreements.
Modeling of Nonthermal Solid‐to‐Solid Phase Transition in Diamond Irradiated with Femtosecond x‐ray FEL Pulse

In this contribution we review in detail our recently developed hybrid model able to trace simultaneously nonequilibrium electron kinetics, evolution of an electronic structure, and eventually nonthermal phase transition in solids irradiated with femtosecond free‐electron laser pulses. Diamond irradiated with an ultrashort intense x‐ray pulse serves as an example to show how an irradiated material undergoes an ultrafast phase transition on sub‐picosecond timescales. The transition of diamond into graphite is induced by an excitation of electrons from the valence band into the conduction band, which, in turn, induces a rapid change of the interatomic potential. Our theoretical model incorporates: a Monte‐Carlo method for tracing high‐energy electrons and K‐shell holes in diamond; a temperature equation for the valence‐band and low‐energy conduction‐band electrons; a tight binding method for calculation of the evolving electronic structure of the material and potential energy surfaces; and molecular dynamics propagating atomic trajectories. This unified approach predicts the damage threshold of diamond in a good agreement with experimentally measured values. It reveals a multi‐step nature of nonthermal phase transition being an interplay between electronic excitation, changes of the band structure, and atomic reordering. An effect of pulse parameters, such as photon energy and temporal pulse shape, on the phase transition is discussed in detail. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Nonlinear electrophoresis at arbitrary field strengths: Small-Dukhin-number analysis

Smoluchowski’s formula for thin-double-layer electrophoresis does not apply for highly charged particles, where surface conduction modifies the electrokinetic transport in the electro-neutral bulk. To date, systematic studies of this nonzero Dukhin-number effect have been limited to weak fields. Employing our recent macroscale model [O. Schnitzer and E. Yariv, “Macroscale description of electrokinetic flows at large zeta potentials: Nonlinear surface conduction,” Phys. Rev. E 86, 021503 (2012)], valid for arbitrary Dukhin numbers, we analyze herein particle electrophoresis at small (but finite) Dukhin numbers; valid for arbitrary fields, this asymptotic limit essentially captures the practical range of parameters quantifying typical colloidal systems. Perturbing about the irrotational zero-Dukhin-number flow, we derive a linear scheme for calculating the small-Dukhin-number correction to Smoluchowski’s velocity. This scheme essentially amounts to the solution of a linear diffusion–advection problem governing the salt distribution in the electro-neutral bulk. Using eigenfunction expansions, we obtain a semi-analytic solution for this problem. It is supplemented by asymptotic approximations in the respective limits of weak fields, small ions, and strong fields; in the latter singular limit, salt polarization is confined to a diffusive boundary layer. With the salt-transport problem solved, the velocity correction is readily obtained by evaluating three quadratures, corresponding to the contributions of (i) electro- and diffuso-osmotic slip due to polarization of both the Debye layer and the bulk; (ii) a net Maxwell force on the electrical double layer; and (iii) Coulomb body forces acting on the space charge in the “electro-neutral” bulk. The velocity correction calculated based upon the semi-analytic solution exhibits a transition from the familiar retardation at weak fields to velocity enhancement at moderate fields; this transition is analytically captured by the small-ion approximation. At stronger fields, the velocity correction approaches a closed-form asymptotic approximation which follows from an analytic solution of the diffusive boundary-layer problem. In this regime, the correction varies as the 3/2-power of the applied field. Our small-Dukhin-number scheme, valid at arbitrary field strengths, naturally lends itself to a tractable analysis of nonlinear surface-conduction effects in numerous electrokinetic problems.
Arsenic pressure dependence of carrier lifetime and annealing dynamics for low-temperature grown GaAs studied by pump–probe spectroscopy

Reflection-type degenerate pump-probe spectroscopy was performed for low-temperature grown (LT-) GaAs to study the effects of arsenic pressure during crystal growth and annealing on carrier lifetime and to ascertain the annealing dynamics. It was found that a sample grown under a high arsenic pressure has a shorter carrier lifetime for both as-grown and anneal conditions. It was also found that the carrier decay times of samples changed drastically when the annealing temperature was above 550 °C. We determined the annealing dynamics of LT-GaAs based on a model in which AsGa antisite defects trap photoexcited carriers. An Arrhenius plot of the carrier decay rate vs. annealing temperature in the high temperature regime gave an energy EPA that was different from the true activation energy. The annealing time dependences of EPA obtained by the two diffusion models (self diffusion and VGa vacancy assisted diffusion of defects) were compared with EPAs of our data and other works, which proved that the annealing.