Miracle-dz/UniFAR-FTUs huggingface dataset:
Near-field optical data storage using C-apertures

We demonstrate the all-optical recording of deeply subwavelength data bits in Ge2Sb2Te5 using a near-field scanning optical microscope (NSOM) probe that utilizes a C-aperture fabricated using through membrane focused ion beam milling. Data bits recorded with various optical powers were read out optically by C-aperture NSOM and the physical bit size was measured by atomic force microscopy (AFM). Both optical and AFM measurements were found to be in excellent agreement with simulation. We achieved a minimum physical bit size of 53.5×50.2 nm2 at a wavelength of 980 nm (λ/20) indicating a data density of 223 Gbit/in.2.
On the existence of steady flows of a Navier–Stokes liquid around a moving rigid body

We prove the existence of a strong solution to the three‐dimensional steady Navier–Stokes equations in the exterior of an obstacle undergoing a rigid motion. Unlike the classical exterior problem for the Navier–Stokes equations, that only takes into account the translational motion of the obstacle, is this case, the obstacle can also rotate. Assuming the total flux of the velocity field through the boundary to be sufficiently small, we first construct approximating solutions in bounded regions ΩR = Ω∩ {x ∈ ℝ3:∣x∣< R} invading the liquid domain Ω. A set of estimates independent of R are shown to hold for the approximating solutions which allows to obtain a strong solution by taking the limit R→∞. Copyright © 2004 John Wiley & Sons, Ltd.
Driving Blind: Weather-Related Vision Hazards and Fatal Motor Vehicle Crashes

AbstractVisibility-related weather hazards have significant impacts on motor vehicle operators because of decreased driver vision, reduced roadway speed, amplified speed variability, and elevated crash risk. This research presents a national analysis of fog-, smoke-, and dust storm–associated vehicular fatalities in the United States. Initially, a database of weather-related motor vehicle crash fatalities from 1994 to 2011 is constructed from National Highway Traffic Safety Administration data. Thereafter, spatiotemporal analyses of visibility-related (crashes where a vision hazard was reported at time of event) and vision-obscured (driver’s vision was recorded as obscured by weather, and a weather-related vision hazard was reported) fatal vehicular crashes are presented. Results reveal that the annual number of fatalities associated with weather-related, vision-obscured vehicular crashes is comparable to those of more notable and captivating hazards such as tornadoes, floods, tropical cyclones, and light.
Penalized quasi-likelihood estimation in partial linear models

Consider a partial linear model, where the expectation of a random variable Y depends on covariates (x, z) through F(θ 0 x + m 0 (z)), with θ 0 an unknown parameter, and m 0 an unknown function. We apply the theory of empirical processes to derive the asymptotic properties of the penalized quasi-likelihood estimator.
Spectral evidence for stirring scales and two-dimensional turbulence in the auroral ionosphere

Electric field power spectra from two auroral sounding rocket flights show evidence of a distinct scale size regime for injection of energy into the auroral oval. The signature of this process is a broad plateau in the spectrum, with power law dependences at both shorter and longer scale sizes. We argue that the spectral properties at high k are dominated by processes occurring near the edges of inverted-V electron precipitation regions (auroral arcs) We see no compelling reason to conclude that a linear local plasma instability is occurring but rather, that nonlinear mixing and forward cascade yield the observed velocity field. The spectra of simultaneously observed density irregularities are quite different from those of the electric field, implying that the plasma density does not behave as a passive scalar in the auroral zone during active conditions. At low-k values we show that the rocket spectra are consistent with the power spectra of magnetospheric electric fields measured by the DE, AE-C, and Hilat stallites.
Waterspouts over the North and Baltic Seas: Observations and climatology, prediction and reporting

On 25 August 2005, three waterspouts were observed close to the research platform FINO1, 45 km off the German North Sea coast and situated in a prospected large offshore wind park area. We analyse this case in relation to the synoptic setting of a waterspout day over the Baltic Sea and compare it to the waterspout climatology of the German Bight and the western and south-western parts of the Baltic Sea. The waterspout hazard to offshore wind parks is assessed as about 1 waterspout per year and per 10 000 km 2 . So, should current scenarios for future wind park development materialise, their large total area may experience a waterspout every other year. The prediction of such events is investigated in view of concepts recently proposed for Mediterranean and western North Sea waterspout forecasting. Reporting issues influencing the climatology encompass both a weekend low in reported events, as well as a bias toward ship routes and main SYNOP times in ship reports. The latter may be mitigated by more reports from yachtsmen.
Effect of plastic deformation on deuterium retention and release in tungsten

The effect of severe plastic deformation on the deuterium retention in tungsten exposed to high-flux low-energy plasma (flux ∼ 1024 D/m2/s, energy ∼ 50 eV, and fluence up to 3 × 1026 D/m2) at the plasma generator Pilot-PSI was studied by thermal desorption spectroscopy and scanning electron microscopy. The desorption spectra in both reference and plastically deformed samples were deconvolved into three contributions attributed to the detrapping from dislocations, deuterium-vacancy clusters, and pores, respectively. The plastically induced deformation, resulting in high dislocation density, does not change the positions of the three peaks, but alters their amplitudes as compared to the reference material. The appearance of blisters detected by scanning electron microscopy and the desorption peak attributed to the release from pores (i.e., deuterium bubbles) were suppressed in the plastically deformed samples but only up to a certain fluence. Beyond 5 × 1025 D/m2, the release from the bubbles in the deformed material is essentially higher than in the reference material. Based on the presented results, we suggest that a dense dislocation network increases the incubation dose needed for the appearance of blisters, associated with deuterium bubbles, by offering numerous nucleation sites for deuterium clusters eventually transforming into deuterium-vacancy clusters by punching out jogs on dislocation lines.
Quasi-neutral limit of the two-fluid Euler-Poisson system

Quasi-neutral limit of the multidimensional isentropic two-fluid Euler-Poisson system is rigorously justified. For well-prepared initial data, as the Debye length goes to zero, the convergence of the bipolar Euler-Poisson system to the compressible Euler equations is proved in the time interval where a smooth solution of the limit problem exists.
The particular solutions for thin plates resting on Pasternak foundations under arbitrary loadings

Analytical particular solutions of splines and monomials are obtained for problems of thin plate resting on Pasternak foundation under arbitrary loadings, which are governed by a fourth‐order partial differential equation (PDEs). These analytical particular solutions are valuable when the arbitrary loadings are approximated by augmented polyharmonic splines (APS) constructed by splines and monomials. In our derivations, the real coefficient operator in the governing equation is decomposed into two complex coefficient operators whose particular solutions are known in literature. Then, we use the difference trick to recover the analytical particular solutions of the original operator. In addition, we show that the derived particular solution of spline with its first few directional derivatives are bounded as r → 0. This solution procedure may have the potential in obtaining analytical particular solutions of higher order PDEs constructed by products of Helmholtz‐type operators. Furthermore, we demonstrate the usages of these analytical particular solutions by few numerical cases in which the homogeneous solutions are complementarily solved by the method of fundamental solutions (MFS). © 2009 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2010
Relative Covering Groups

Abstract Let ν and ω be two varieties of groups defined by the sets of laws V and W, respectively. We introduce the concept of a ω-ν-covering group of a given group and show that every two ω-ν-covering groups of a given group in ω are ν-isologic. Also, in the case ν ⊆ ω, we show the existence of such groups for a finite ν-perfect group in ω, and also that every automorphism of a finite ν-perfect group G in ω may be lifted to an automorphism of a ω-ν-covering group of G. Finally we show that if G is in ω ∩ ν, then all ω-ν-covering groups of G are Hopfian.
Comparing Deep Mixing in Globular Cluster and Halo Field Giants: Carbon Abundance Data from the Literature

The behavior of carbon abundance as a function of luminosity is used to compare the rates of deep mixing within red giants of four globular clusters and the Galactic halo field population. Measurements of [C/Fe] for the clusters M92, NGC 6397, M3, and M13 have been compiled from the literature, together with the Gratton et al. data for halo field stars. Plots of [C/Fe] versus absolute visual magnitude show that for MV< +1.6 the rate of decline of carbon abundance with increasing luminosity on the red giant branch is d[C/Fe]/dMV ≈ 0.22 ± 0.03 among the field stars, as well as in M92, NGC 6397, and M3. Among giants fainter than MV = +1.6 the variation of [C/Fe] with absolute magnitude is much less. The data indicate that the rate at which deep mixing introduces carbon‐depleted material into the convective envelopes of field halo stars during the upper red giant branch phase of evolution is similar to that of many globular cluster giants. The notable exception appears to be M13, in which stars exhibit deep mixing at a greater rate; this may account for the high incidence of very low oxygen abundances among the most luminous giants in M13 in comparison to M3.
Acoustic focusing by metal circular ring structure

We report an exotic acoustic focusing effect through a simple brass circular ring structure immersed in water. The acoustic waves can be focused on a prefect point at the centre of the ring structure. This exotic acoustic focusing phenomenon arises from the intrinsic modes in the ring structure at some special eigenfrequencies, which is essentially distinct from the previous studies originating from the negative refraction. The focusing effect is closely related to the size and shape of the ring structure. Interesting applications of the focusing mechanism in black box detectors in the sea and medical ultrasound treatment are further discussed.
Optical image reconstruction using frequency-domain data: simulations and experiments

Optical image reconstruction in a heterogeneous turbid medium with the use of frequency-domain measurements is investigated in detail. A finite-element reconstruction algorithm for optical data based on a diffusion equation approximation is presented and confirmed by a series of simulations and experiments using phantoms having optical properties in the range of those expected for tissues. Simultaneous reconstruction of absorption and scattering coefficients is achieved both theoretically and experimentally. Images with different target locations and contrast levels between target and background are also successfully recovered. All reconstructed images from both simulated and experimental data are derived directly from absolute optical data in which no differential measurement scheme is used. Results from the use of simulated and measured data suggest that quantitative images can be produced in terms of absorption and scattering coefficient values and location, size, and shape of heterogeneities within a circular background region over a range of contrast levels. Further, the effects of modulation frequency are found to be relatively modest, although boundary conditions appear to be important factors.
Some Measurements of Interaural Time Difference Thresholds

Thresholds for the detection of interaural time difference were determined by ten listeners (1) for band‐limited random noise (150–1700 cps), (2) for a 1000‐cps tone, and (3) for a 1‐millisecond click. The average interaural time differences corresponding to 75% correct detection in the symmetrical two‐alternative tests were (1) 9 microseconds, (2) 11 microseconds, and (3) 28 microseconds. Ranges of individual thresholds and group psychometric functions are presented.
The suppression of deep moist convection near the southern Great Plains dryline

Abstract Deep moist convection failed to initiate over the Texas Panhandle on 6 May 1995 despite expectations to the contrary by the forecasters for the Verification of the Origins of Rotation in Tornadoes Experiment (VORTEX). The National Centers for Environmental Prediction–National Center for Atmospheric Research (NCEP–NCAR) reanalysis is used to identify a midlevel migratory short-wave ridge propagating across the area during the time of maximum diurnal heating. Subsidence values of 1.0 × 10−3 hPa s−1 for a period exceeding several hours were associated with the ridge and led to substantial (∼3 K) warming in the midlevels and to the formation of a strong inversion around 600 hPa. A number of independent observations are examined to corroborate the hypothesis that the passage of the midlevel short-wave ridge at the time of maximum diurnal heating is ultimately responsible for the absence of deep moist convection. Twelve-hour forecasts of the 1995 NCEP operational model suite and the Pennsylvania State .
Stark shift measurements of Xe II and Xe III spectral lines

Stark shift measurements of singly and doubly ionized Xe spectral lines are presented in this paper. Shifts of 110 Xe II lines and 42 Xe III lines are reported, including a significant number of new results. A low-pressure-pulsed arc with 95% of He and 5% of Xe was used as a plasma source. All measurements were performed under the following plasma conditions: electron density (0.2–1.4) × 1023 m−3 and electron temperature 18 000–23 000 K. The measured Stark shifts are compared with other experimental and theoretical data.
High-throughput assembly of nanoelements in nanoporous alumina templates

The authors demonstrate a nanofabrication method utilizing nanoporous alumina templates which involves directed three dimensional assembly of nanoparticles inside the pores by means of an electrophoretic technique. In their demonstration, they have assembled polystyrene nanobeads with diameter of 50nm inside nanopore arrays of height of 250nm and diameter of 80nm. Such a technique is particularly useful for large-scale, rapid assembly of nanoelements for potential device applications.
Computational biomechanics and experimental validation of vessel deformation based on 4D-CT imaging of the porcine aorta

Cardiovascular disease results from pathological biomechanical conditions and fatigue of the vessel wall. Image-based computational modeling provides a physical and realistic insight into the patient-specific biomechanics and enables accurate predictive simulations of development, growth and failure of cardiovascular disease. An experimental validation is necessary for the evaluation and the clinical implementation of such computational models. In the present study, we have implemented dynamic Computed-Tomography (4D-CT) imaging and catheter-based in vivo measured pressures to numerically simulate and experimentally evaluate the biomechanics of the porcine aorta. The computations are based on the Finite Element Method (FEM) and simulate the arterial wall response to the transient pressure-based boundary condition. They are evaluated by comparing the numerically predicted wall deformation and that calculated from the acquired 4D-CT data. The dynamic motion of the vessel is quantified by means of the hydraulic diameter, analyzing sequences at 5% increments over the cardiac cycle. Our results show that accurate biomechanical modeling is possible using FEM-based simulations. The RMS error of the computed hydraulic diameter at five cross-sections of the aorta was 0.188, 0.252, 0.280, 0.237 and 0.204 mm, which is equivalent to 1.7%, 2.3%, 2.7%, 2.3% and 2.0%, respectively, when expressed as a function of the time-averaged hydraulic diameter measured from the CT images. The present investigation is a first attempt to simulate and validate vessel deformation based on realistic morphological data and boundary conditions. An experimentally validated system would help in evaluating individual therapies and optimal treatment strategies in the field of minimally invasive endovascular surgery.
The nonlinear stability of flows over compliant walls

The weakly nonlinear, high-Reynolds-number triple-deck theory of Smith (1979) is applied to Blasius flow over a compliant wall. Attention is concentrated on Tollmien–Schlichting (TS) disturbance waves. We consider wall models of the Carpenter–Garrad type, modified to cater for three-dimensional disturbances, and allowing for the effects of nonlinear wall curvature. Supercritical equilibrium-amplitude states are possible for TS waves in a rigid-wall boundary layer, as is well known (see for example Smith 1979; Hall & Smith 1984). It is found that judicious choice of wall parameters can dramatically alter the nonlinear stability properties of TS waves in the boundary layer over a compliant wall: waves that are linearly damped may become nonlinearly unstable. Excellent agreement is obtained with rigid-wall results of Hall & Smith (1984).
Optimization of a Rectangular Orifice Synthetic Jet Generator

A rectangular orifice synthetic jet may be an effective means of generating longitudinal embedded vortices within low Reynolds number boundary layers for flow control. There is relatively little data available relating to the jet characteristics as a function of key geometric parameters. A series of experimental measurements using a modular synthetic jet are reported in which orifice length and resonance cavity depth are varied for a single diaphragm system operating at optimum excitation frequency. The maximum time averaged jet velocity is seen to decrease with both increasing orifice length and increasing cavity depth. Orifice length/width ratios of less than 10 produce a more uniform jet velocity distribution.
A large survey of electron acceleration events

Precipitation data from all Defense Meteorological Satellite Program (DMSP) satellites over a 9-year interval were surveyed for electron acceleration events. Selected events evinced a sharp drop above the spectral peak; therefore only instances where the accelerating potential is 3–4 or more times larger than the source thermal energy were studied. In all, more than 1.5 × 108 individual electron spectra were examined for signs of such substantial field-aligned acceleration. Several controversies can be resolved by this survey; for example, the “midday gap” is real, with noon easily the least likely local time for observing electron acceleration. The debated “14 MLT (magnetic local time) hot spot” is also real, although it is centered about 15 MLT and is distinct from the rest of the oval only for northward interplanetary magnetic field (IMF) conditions. A weaker “warm” spot exists in the 6–9 MLT region. Potential drops of ∼3 keV and above are statistically the province of the nightside, as are the most intense energy fluxes (>1 erg cm−2 s−1). The latitudinal scale size of acceleration events fits surprisingly well to an exponential distribution with a characteristic width ( = 28–35 km) that varies only slightly with MLT and IMF conditions. If represents the ionospheric footprint of the driving magnetospheric processes, the best candidate explanation is velocity shears in the main plasma sheet. However, the fact that an exponential distribution of latitudinal widths exists under a variety of conditions suggests an alternative. If there exist large-scale regions embedded within the auroral oval wherein each spectrum has a random probability P of experiencing electron acceleration independent of neighboring spectra, then the occurrence distributions are explained, and actually indicates the value of P (namely, ∼0.85).
Verification of a Higher-Order Finite Difference Scheme for the One-Dimensional Two-Fluid Model

The one-dimensional two-fluid model is widely acknowledged as the most detailed and accurate macroscopic formulation model of the thermo-fluid dynamics in nuclear reactor safety analysis. Currently the prevailing one-dimensional thermal hydraulics codes are only first-order accurate. The benefit of first-order schemes is numerical viscosity, which serves as a regularization mechanism for many otherwise ill-posed two-fluid models. However, excessive diffusion in regions of large gradients leads to poor resolution of phenomena related to void wave propagation. In this work, a higher-order shock capturing method is applied to the basic equations for incompressible and isothermal flow of the one-dimensional two-fluid model. The higher-order accuracy is gained by a strong stability preserving multi-step scheme for the time discretization and a minmod flux limiter scheme for the convection terms. Additionally the use of a staggered grid allows for several second-order centered terms, when available. The continu.
Accurate dependence of gallium nitride thermal conductivity on dislocation density

The authors experimentally find that the thermal conductivity of gallium nitride depends critically on dislocation density using the 3-omega technique. For GaN with dislocation densities lower than 106cm−2, the thermal conductivity is independent with dislocation density. The thermal conductivity decreases with a logarithmic dependence for material with dislocation densities in the range of 107–1010cm−2. These results are in agreement with theoretical predictions. This study indicates that the hydride vapor phase epitaxy method offers an attractive route for the formation of semi-insulating gallium nitride with optimal thermal conductivity values around 230W∕mK and very low dislocation density near 5×104cm−2.
Consensus problem of data-sampled networked multi-agent systems with time-varying communication delays

This paper investigates an observer-based control strategy for networked multi-agent systems with general linear dynamics and time-varying communication delays in a sampling setting. The communication topology is assumed to be directed fixed. Different from a traditional observer-based controller for a single system, the objects that need to be observed here are the state differences between an agent and its neighbours. Using a system transformation method, some equivalent conditions concerning the consensus of multi-agent systems are established. Moreover, we prove that both the connection weights and the communication topology play an important role in the study of multi-agent systems, and establish a linear matrix inequality based observer design method.
H∞ optimal control. Part 1. Model matching

Our aim in this paper is to develop a new approach for solving the H ∞ optimal control problem where the feedback arrangement takes the form of a linear fractional transformation. The paper is in two parts. In Part 1, a basic kind of model-matching problem is considered: given rational matrices M(s) and N(s), the H ∞-norm of an error function defined as E(s)=M(s) – N(s)Q(s) is minimized (or bounded) subject to E(s) and Q(s) being stable. Closed-form state-space characterizations are obtained for both E(s) and Q(s). The results established here will be used in Part 2 of the paper (Hung 1989) to solve the H ∞ optimal control problem.