Miracle-dz/UniFAR-FTUs huggingface dataset:
Space-Time Adaptive Methods for Beam Dynamics Simulations

This work establishes techniques for adjusting the local spatial resolution of selected numerical methods in a time-adaptive manner. Such techniques are developed within the framework of the Finite Integration Technique (FIT), a hybrid Finite Integration-Finite Volume (FI-FV) Scheme and the Discontinuous Galerkin Method (DGM). While the FIT and the DGM are established methods for the numerical solution of electromagnetic field problems, the FI-FV scheme has been developed in the context of this work. The semi-discrete, i.e., discrete in space and continuous in time, as well as the fully discretized formulations of all considered methods are presented. For both formulations of each method, an analysis of the dispersive and dissipative behavior on fixed computational grids is carried out. As a result, asymptotic orders of the dispersion and dissipation errors are established. Techniques for the determination and modification of the discrete electromagnetic field quantities in locally refined regions are presented for each of the numerical methods. For the FIT and the FI-FV Scheme, adaptations based on linear and third order spline interpolations are presented. The adaptation techniques for the DGM are based on projection operators, which are shown to minimize the adaptation error. The numerical stability of the developed adaptive methods is proven. The developed algorithms are applied to the self-consistent simulation of charged particle dynamics and electrodynamics. The results of the first design study simulating the complete first section of the Free-Electron Laser in Hamburg (FLASH), taking space charge and structure interactions into account, are presented.
Comparison between computational fluid dynamics, fluid–structure interaction and computational structural dynamics predictions of flow-induced wall mechanics in an anatomically realistic cerebral aneurysm model

Haemodynamically induced stress plays an important role in the progression and rupture of cerebral aneurysms. The current work describes computational fluid dynamics (CFD), fluid–structure interaction (FSI) and computational structural dynamics (CSD) simulations in an anatomically realistic model of a carotid artery with two saccular cerebral aneurysms in the ophthalmic region. The model was obtained from three-dimensional (3D) rotational angiographic imaging data. CFD and FSI were studied under a physiologically representative waveform of inflow. The arterial wall was assumed elastic or hyperelastic, as a 3D solid or as a shell depending on the type of modelling used. The flow was assumed to be laminar, non-Newtonian and incompressible. The CFD, FSI and CSD models were solved with the finite elements package ADINA. Predictions of velocity field and wall shear stress (WSS) on the aneurysms made using CFD and FSI were compared. The CSD model of the aneurysms using complete geometry was compared with isolated aneurysm models. Additionally, the effects of hypertensive pressure on CSD aneurysm models are also reported. The vortex structure, WSS, effective stress, strain and displacement of the aneurysm walls showed differences, depending on the type of modelling used.
Bias-stress-induced stretched-exponential time dependence of threshold voltage shift in InGaZnO thin film transistors

The experimental and modeling study of bias-stress-induced threshold voltage instabilities in amorphous indium-gallium-zinc oxide thin film transistors is reported. Positive stress results in a positive shift in the threshold voltage, while the transfer curve hardly moves when negative stress is induced. The time evolution of threshold voltage is described by the stretched-exponential equation, and the shift is attributed to the electron injection from the channel into interface/dielectric traps. The stress amplitudes and stress temperatures are considered as important factors in threshold voltage instabilities, and the stretched-exponential equation is well fitted in various bias temperature stress conditions.
The limiting behaviour of turbulence near a wall

Three different Navier-Stokes computational models of incompressible viscoussublayer turbulence have been developed. Comparison of computed turbulence quantities with experiment is made for the mean streamwise velocity, Reynolds stress, correlation coefficient and dissipation; for the r.m.s. fluctuation intensities of streamwise vorticity, Reynolds stress and three velocity components; and for the skewness and flatness of fluctuating streamwise velocity and Reynolds stress. The comparison is good for the first three of these quantities, and reasonably good for most of the remainder. Special computer runs with a very fine mesh and small Courant number were made to define the limiting power-law behaviour of turbulence near a wall. Such behaviour was found to be confined to about 0.3 wall units from the wall, and to be: linear for streamwise turbulence, spanwise turbulence, vorticity normal to the wall, and for the departures from their respective wall values of dissipation, streamwise vorticity and spanwise vorticity; second power for turbulence normal to the wall; third power for Reynolds stress; and a constant value of the correlation coefficient for Reynolds stress. A simple physical explanation is given for the third-power variation of Reynolds stress and for the broad generality of this limiting variation. Applications are made to Reynolds-average turbulence modelling: damping functions for Reynolds stress in eddy-viscosity models are derived that are compatible with the near-wall limiting behaviour; and new wall boundary conditions for dissipation in k-ε models are developed that are similarly compatible.
Measuring Antenna Patterns for Ocean Surface Current HF Radars with Ships of Opportunity

AbstractHF radars measure ocean surface currents near coastlines with a spatial and temporal resolution that remains unmatched by other approaches. Most HF radars employ direction-finding techniques, which obtain the most accurate ocean surface current data when using measured, rather than idealized, antenna patterns. Simplifying and automating the antenna pattern measurement (APM) process would improve the utility of HF radar data, since idealized patterns are widely used. A method is presented for obtaining antenna pattern measurements for direction-finding HF radars from ships of opportunity. Positions obtained from the Automatic Identification System (AIS) are used to identify signals backscattered from ships in ocean current radar data. These signals and ship position data are then combined to determine the HF radar APM. Data screening methods are developed and shown to produce APMs with low error when compared with APMs obtained with shipboard transponder-based approaches. The analysis indicates tha.
Enhanced Heat Transfer, Missing Pin, and Optimization for Cylindrical Pin Fin Arrays

We report an experimental investigation on the effects of interfin spacing, shroud clearance, and missing pin on the heat transfer from cylindrical pin fins arranged in staggered and in-line arrays. The interfin spacing in the spanwise direction was so small that the pins were almost touching each other. The optimum interfin spacing in both spanwise and streamwise directions is 2.5 D regardless of both type of array and shroud clearance used.
Explanation for the temperature dependence of the gate current in metal-oxide-semiconductor transistors

The temperature dependence of hot-electron induced gate current in metal-oxide-semiconductor transistors is investigated by means of Monte Carlo simulation. The Monte Carlo model features an approach to the short range Coulomb interaction that provides a better statistical enhancement of “rare” short range electron-electron scattering (EES) events allowing a much better estimate of the distribution function at high energy. It is demonstrated that the gate current temperature dependence is due to EES. In particular, it is shown that EES efficiency in pushing carrier towards higher energy is independent of the lattice temperature. Therefore, reducing the temperature the number of carriers with energy near the applied drain voltage increases because of the reduced phonon scattering. Thus, a larger number of carriers are pushed by EES above the Si/SiO2 energy barrier for lower lattice temperature.
ESTIMATING THE DISTRIBUTION OF TREATMENT EFFECTS

In this paper we show that the distribution of treatment effects is point identified in a model where the outcome equation is of unrestricted form and the selection equation contains more than one unobservable. This is different and economically better motivated than the treatment effect on the distribution, usually the quantiles, which is commonly analyzed in the literature. Our key identifying assumption in the selection equation is a linear random coefficients structure and the assumption that the instruments are continuously distributed. This allows point identification of the entire distribution of treatment effects under conditions on unobserved heterogeneity that unlike the case of additively separable/monotonic scalar unobservables have a clear economic interpretation in terms of unobserved heterogeneity. Also, we obtain results on the distribution of treatment effects without invoking any scalar monotonicity assumption in the outcome equation. Moreover, the identification is constructive and suggests estimators of various quantities of interest by sample counterparts.
Uniform solutions for scattering by a potential barrier and bound states of a potential well

The one‐dimensional Schrodinger equation is solved asymptotically for scattering of a particle by a potential barrier and for bound states of a potential well, when the potentials change little in a wavelength. Both solutions are represented uniformly in space, rather than nonuniformly as in the WKB method. This avoids matching expansions and using connection formulas. The scattering solution and the complex reflection and transmission coefficients are also uniform in the particle energy.
New Look to the Constant Radial Acceleration Problem

is revisited. Some closed-form analytical solutions for this problem exist: in particular, those regarding the acceleration level required for obtaining an escape condition and the value of the maximum amplitude of the radial oscillation when an escape does not occur. Other results are known to exist in terms of elliptic integrals; however, their practical use for mission design is difficult due to the lack of physical insight connected to these mathematical functions. This paper provides new theoretical results for the motion description and new accurate approximations forboththespacecrafttrajectoryandthetimeof flightusingsimpleandclosed-formrelationships.Thisispossibleby introducingasuitable regularizationofthemotion,forwhichthesolution isperiodicwithrespecttotheindependent angular variable, and therefore can be exactly expressed in terms of a Fourier series. The new results are conveniently applied to a spacecraft repositioning problem and to a sample-return mission. Nomenclature a = osculating orbit’s semimajor axis, distance unit b = dimensionless fitting coefficient c = dimensionless Fourier coefficient e = osculating orbit eccentricity h = osculating orbit’s angular momentum, � distance unit� 2 =time unit k = modulus of � N = number of complete radial oscillations n = parameter of � r = radial distance, distance unit
Bayesian inference in statistical analysis

Nature of Bayesian Inference Standard Normal Theory Inference Problems Bayesian Assessment of Assumptions: Effect of Non-Normality on Inferences About a Population Mean with Generalizations Bayesian Assessment of Assumptions: Comparison of Variances Random Effect Models Analysis of Cross Classification Designs Inference About Means with Information from More than One Source: One-Way Classification and Block Designs Some Aspects of Multivariate Analysis Estimation of Common Regression Coefficients Transformation of Data Tables References Indexes.
Demonstration of a superconducting inductive pulsed power supply at simulated load conditions

A laboratory set-up of a 0.5 MJ superconducting pulsed power supply is described. This combination of a superconducting inductive energy storage system with a superconducting pulse switch is performed using standard NbTi technology. Two principles of laboratory pulse loads are introduced, which simulate voltage and current conditions similar to those of ETC applications. The experimental results of pulse discharge experiments confirm good compatibility of inductive energy storage and the load simulators. Further experimental results demonstrate the possibility of pulse conditioning by sequential discharge of storage modules.
Time decorrelation in isotropic magnetohydrodynamic turbulence

Time decorrelation in isotropic incompressible magnetohydrodynamic (MHD) turbulence is studied using three-dimensional numerical simulation. Eulerian and wavenumber-dependent correlation functions are obtained. Scaling with wavenumber separates effects of nonlinear distortion and effects of random sweeping and Alfvénic wave propagation. Results show that the dominant effect is the combined influence of convective sweeping and Alfvénic propagation, both being nonlocal effects on small-scale fluctuations by large-scale fluctuations. This conclusion finds applications in space plasma observation, particle scattering, predictability, and turbulence theory.
The effect of rotation and a buried magnetic field on stellar oscillations

Une methode de perturbation permettant de determiner les modifications de frequence resultantes, causees par la rotation et le champ magnetique interne, sur les oscillations stellaires est presentee. Les effets de differentes vitesses angulaires et configurations du champ magnetique sur les modes acoustiques solaires de grands ordres sont analyses
Notions of Discrimination

As an outgrowth of the study of algebraic geometry over groups, discriminating groups were introduced. Many important universal type groups such as Higman's universal group and Thompson's group F were shown to be discriminating. Squarelike groups were then introduced to better capture axiomatic properties of discrimination. In the present article squarelike groups are reinterpreted in terms of discrimination of quasi varieties, and the relationship with an older version of discrimination, termed varietal discrimination here, is studied.
Image depth estimation from compressed sensing theory

Depth information of the image is really necessary information to reconstruct a 3-dimensional object. The classical methods of depth estimation are generally divided into two categories: active and passive methods. The active methods requires the additional lighting equipment, passive methods also have a series of problems . They require a plurality of images obtained by capturing a plurality of viewpoints , and determine the locating occlusion boundary , etc., and hence the depth estimation has been a challenging problem in the research field of computer vision.1 Because of the depth information of the image has a natural sparse features, this paper uses a passive approach, the signal of sparse priori based on compressed sensing theory is used to estimate the depth of the image, without capturing multiple images, using a single input image can obtain a high quality depth map. Experimental results show that the depth map obtaining by our method, compared to the classical passive method, the contour sharpness, the depth of detail information and the robustness of noise are more advantages. The method also can be applied to re-focus the defocused images, and automatic scene segmentation and other issues, ultimately may have broad application prospects in the reconstruction of true 3-dimensional objects.
Effects of Lower Boundary Conditions on the Stability of Radiative Shocks

Abstract Thermal instabilities can cause a radiative shock to oscillate, thereby modulating the emission from the post-shock region. The mode frequencies are approximately quantised in analogy to those of a vibrating pipe. The stability properties depend on the cooling processes, the electron–ion energy exchange, and the boundary conditions. This paper considers the effects of the lower boundary condition on the post-shock flow, both ideally and for some specific physical models. Specific cases include constant perturbed velocity, pressure, density, flow rate, or temperature at the lower boundary, and the situation with nonzero stationary flow velocity at the lower boundary. It is found that for cases with zero terminal stationary velocity, the stability properties are insensitive to the perturbed hydrodynamic variables at the lower boundary. The luminosity responses are generally dependent on the lower boundary condition.
Towards scalable photonics via quantum storage

Single photons are a vital resource for optical quantum information processing. Efficient and deterministic single photon sources do not yet exist, however. To date, experimental demonstrations of quantum processing primitives have been implemented using non-deterministic sources combined with heralding and/or postselection. Unfortunately, even for eight photons, the data rates are already so low as to make most experiments impracticable. It is well known that quantum memories, capable of storing photons until they are needed, are a potential solution to this `scaling catastrophe'. Here, we analyze in detail the benefits of quantum memories for producing multiphoton states, showing how the production rates can be enhanced by many orders of magnitude. We identify the quantity $eta B$ as the most important figure of merit in this connection, where $eta$ and $B$ are the efficiency and time-bandwidth product of the memories, respectively. We go on to review our progress in implementing the most broadband memory to date, with $B<1000$, in room-temperature cesium vapour. We consider the noise properties for single photon storage and the integration of the memory using waveguides.
The peculiar velocity of the Local Group – I. H I observations of Sb and Sbc galaxies

On presente les resultats d'observations HI d'un echantillon de 128 galaxies Sb et Sbc. On discute de leurs proprietes physiques et de la formation stellaire. Leurs diametres lineaires s'echelonnent de 9 kpc (UGC 10554) a 128 kpc (UGC 2885) et leurs masses totales de 6,3×10 9 M ○. a 1,3×10 12 M ○.
Z dependence of the core impurity transport in ASDEX Upgrade H mode discharges

The dependence of core plasma impurity transport on the Z number has been investigated for ASDEX Upgrade H? mode discharges. For the elements Ne, Ar, Kr and Xe the diffusion coefficient in the centre is D ? 6 ? 10-2m2/s and rises with the radial distance from the centre. With increasing Z number the transport becomes strongly convective with inward directed drift velocities that produce very peaked impurity densities for high Z. The inward drift decreases with decreasing deuterium density gradient. Neoclassical transport of the impurities has been calculated numerically. The calculated diffusion coefficient and drift velocity are close to the experimental values for the lower-Z elements Ne and Ar. However, for high Z, the calculated diffusion coefficient is smaller by a factor of up to 2.5 and the inward drift velocity is too small by a factor of 10. Toroidal rotation of the plasma that leads to an increased impurity density on the outboard side of the flux surfaces is not taken into account by the neoclassical calculations. Inboard/outboard asymmetries are not present for Ar and Ne with toroidal Mach number Mtor around 1. However, for heavier elements than Kr with Mtor ? 2 and an outboard/inboard ratio of ? 1.5, poloidal variation of the impurity density is important and might account for the discrepancy between the measured and calculated transport coefficients.
IRAS observations of galaxies in the Virgo cluster area

IRAS data on 196 galaxies in the area of the Virgo Cluster are presented. The data derive from combining all available survey observations for each object and therefore achieve greater sensitivity than the IRAS Point Source Catalog (PSC). The enhanced sensitivity allows 78 galaxies to be detected at 12 microns, 82 at 25 microns, 139 at 60 microns, and 135 at 100 microns, compared to 16, 23, 88, and 95 detections listed in the PSC. From the blue compact dwarf galaxy sample, 23 and 19 objects are detected at 60 and 100 microns, compared to three and two detections listed in the PSC. The emission in three close pairs of galaxies which are reported as single sources in the PSC are separated here. These statistics demonstrate the importance and potential of a detailed examination of IRAS data, especially for possibly resolved sources and, in particular, for galaxies out to redshifts of 0.008 or galaxies with D(25) of 3 arcmin or greater. 16 references.
Effect of Biodiesel Fuel on Direct Injection Diesel Engine Performance

The effect of biodiesel fuel on direct injection diesel engine performance was investigated. Biodiesel fuel used in this study was made by an esterification of palm oil. It was blended with diesel fuel, and the blend ratio was changed from 0 to 20 wt %. The direct injection diesel engine used here was a single-cylinder general-purpose engine. The excess air ratio was changed from 1.85 to 3.0. CO, CO 2 , NO, NO 2 , and N 2 O concentrations in the exhaust gas were measured. Exhausted particulate matter was collected by a quartz glass filter and its components, such as soluble organic fraction, dry soot, and sulfate, were analyzed. Moreover, the size distribution of the particulate matter was analyzed using a scanning mobility particle sizer. The heat release rate and fuel injection rate in each condition were also measured to examine the relation between emission characteristics and combustion conditions. There was no apparent dependence of the biodiesel fuel blend ratio on the heat release rate and exhaust gas composition. This result shows that the combustion characteristics, such as ignition delay, did not change with the blended ratio, because the cetane index of the biodiesel fuel was equivalent to that of the diesel fuel. On the other hand, the particulate matter had a clear dependence on the biodiesel fuel blend ratio. When the blend ratio was 20 wt%, the amount of particulate matter was more than that in the 5 wt% and 10 wt% blended fuels. It was shown that, moreover, the amount of soluble organic fraction increased with an increase of the blend ratio. In the measured results of particulate matter size distributions, it was noteworthy that nanosize particulates (ranging from 10-20 nm) increased when 20 wt% biodiesel fuel blended fuel was used. From these results, it was inferred that the nanoparticles in the range of 10-20 nm were soluble organic fraction related particles. From the viewpoint of the reduction of particulate matter emission, we concluded that the optimum biodiesel fuel blend ratio was 5-10 wt%.