Miracle-dz/UniFAR-FTUs huggingface dataset:
Effect of long-range elastic interactions on the toroidal moment of polarization in a ferroelectric nanoparticle

The effect of long-range (LR) elastic interactions on the toroidal moment of polarization in a two-dimensional ferroelectric particle is investigated using a phase field model. The phase field simulations exhibit vortex patterns with purely toroidal moments of polarization and negligible macroscopic polarization when the spontaneous strains are low and the simulated ferroelectric size is small. However, a monodomain structure with a zero toroidal moment of polarization is formed when the spontaneous strains are high in small simulated ferroelectrics, indicating that, because of the LR elastic interactions, high values of spontaneous strains hinder the formation of polarization vortices in ferroelectric particles.
On the Need for a Common API for Abstract Domains of Object-Oriented Programs

In the last years almost all families of programming languages, from imperative to functional, logic, object-oriented and machine code, have been subject to static analysis by abstract interpretation. The use of a principled approach to static analysis based on the theory of abstract interpretation provided mathematical tools to reason about program properties and allowed for the rigorous and incremental design of precise and scalable static analyzers, ensuring soundness by construction. The large variety of abstract domains for many different programming languages, the ability to combine and refine them with standard abstract interpretation tools and the availability of mature abstract domain libraries allowed easily porting, reusing and experimenting with techniques born in a specific family to other programming languages and properties. Since the use of abstract interpretation for the analysis of object-oriented languages is less common than in other application fields of static analysis, in order to increase its adoption, we advocate the need to establish a common interface for designing and implementing abstract domains for the static analysis of Java-like programs. This interface should allow developing abstract domains pluggable in a generic abstract interpreter, as it is customary, for example, in abstract interpretation-based static analysis of numerical properties.
Influence of nonlinear effects on the three-photon excitation of L-Tryptophan in water using phase-shaped pulses

We show that nonlinear effects like self-phase modulation in a sample have to be considered for phase control of three-photon excitations. Furthermore, we demonstrate the control of three-photon excitation of L-Tryptophan in water using a pulse-shaping setup. Simulations of the propagation of the laser pulses in the cuvette exhibit good agreement with the experimental fluorescence scans at different laser intensities and show large discrepancies when neglecting nonlinear effects prior to the three-photon process. This can lead to improvements in selective excitation of amino acids by a near-infrared femtosecond laser source.
THE BEHAVIOR OF FORECAST ERRORS FROM A NEARLY INTEGRATED AR(1) MODEL AS BOTH SAMPLE SIZE AND FORECAST HORIZON BECOME LARGE

We develop asymptotic approximations to the distribution of forecast errors from an estimated AR(1) model with no drift when the true process is nearly I(1) and both the forecast horizon and the sample size are allowed to increase at the same rate. We find that the forecast errors are the sums of two components that are asymptotically independent. The first is asymptotically normal whereas the second is asymptotically nonnormal. This throws doubt on the suitability of a normal approximation to the forecast error distribution. We then perform a Monte Carlo study to quantify further the effects on the forecast errors of sampling variability in the parameter estimates as we allow both forecast horizon and sample size to increase.
Effective thermal conductivity of clayey aerated concrete in the dry state: experimental results and modelling

The aim of this study was to determine the effective thermal conductivity of a new insulating building material, called clayey aerated concrete (CAC), when used in a dry state. A series of six mixtures having different porosities obtained by adding aluminium powder to the clay-cement matrix was used in the investigation. The measurements of thermal conductivity have been performed inside a closely controlled climatic cell at ambient temperature (20 1C) using a 'line source' method. The experimental results reveal that enhanced thermal performances can thus be obtained by the development of local materials, and their use in building insulation reveals very interesting properties as compared to other building materials. The study has been extended to the research of theoretical models capable of predicting the effective thermal conductivity of dry CAC considered as a two-phase system. Three models based on a geometric mean approach (Asaad model, Veerendra and Chaudhary model) and a effective continuous medium approach (Pande and Chaudhary model) were used. In order to predict effective thermal conductivity of elaborated material using such models, a correction term has been empirically determined and introduced in these models, taking into account the effect of a higher ratio of the thermal conductivity (s=f ). A very good agreement has been observed between the analytical and experimental results, thereby confirming the model's ability to predict the effective thermal conductivity of dry CAC.
Laser oscillation from quantum states in very thin GaAs−Al0.2Ga0.8As multilayer structures

We report optically pumped laser oscillation from multilayer heterostructures consisting of alternating layers of GaAs and Al0.2Ga0. 8As. Very thin GaAs layers (50−500 A) exhibit one−dimensional bound states above the band gap of bulk GaAs. The laser oscillation occurs at energies which are slightly below the exciton associated with the lowest energy n=1 bound state.
A numerical study on shear layer behaviour in flow over a square unit of four cylinders at Reynolds number of 200 using the LB method

The major purpose of the present research is developing the Lattice Boltzmann (LB) method as an extremely efficient computational technique in the pragmatic field of fluid-structure interactions. Hence, the LB method is employed in simulating the incompressible flow past a square unit of four equal diameter circular cylinders. The simulation is conducted at Re of 200 and the spacing ratio (L/D) increases from 1.5 to 5 in 0.5 steps to cover all closely, moderately and widely spaced cases. Accordingly, the effects of the spacing ratio on the shear layer’s behaviour and vortex shedding pattern are studied in detail. Furthermore, its effects on the main force characteristics, i.e., lift and drag coefficients and also the Strouhal number are fully investigated. The observations and results obtained by the LB method employed in the current work are in strict accordance with experimental evidence of other researchers and other existent numerical data in the literature.
Modelling the spread in space and time of an airborne plant disease

Summary. A spatiotemporal model is developed to analyse epidemics of airborne plant diseases which are spread by spores. The observations consist of measurements of the severity of disease at different times, different locations in the horizontal plane and different heights in the vegetal cover. The model describes the joint distribution of the occurrence and the severity of the disease. The three‐dimensional dispersal of spores is modelled by combining a horizontal and a vertical dispersal function. Maximum likelihood combined with a parametric bootstrap is suggested to estimate the model parameters and the uncertainty that is attached to them. The spatiotemporal model is used to analyse a yellow rust epidemic in a wheatfield. In the analysis we pay particular attention to the selection and the estimation of the dispersal functions.
A Weak Invariance Principle with Applications to Domains of Attraction

Abstract : An elementary probabilistic argument is given which establishes a 'weak invariance principle' which in turn implies the sufficiency of the classical assumptions associated with the weak convergence of normed sums to stable laws. The argument, which uses quantile functions (the inverses of distribution functions), exploits the fact that two random variables X = F sup(-1)(U) and Y = G sup(-1)(U) are, in a useful sense, close together when F and G are, in a certain sense, close together. Here U denotes a uniform variable on (0,1). Byproducts of the research are two alternative characterizations for a random variable being in the domain of partial attraction to a normal law and some results concerning the study of domains of partial attraction.
Compensation of compromised PRC2 regulation by a miRNA ensures robustness of Arabidopsis leaf development

Robustness is pervasive throughout biological systems, enabling them to maintain persistent outputs despite perturbations in their components. Here, we reveal a novel mechanism contributing to leaf morphology robustness in the face of genetic perturbations. In Arabidopsis, leaf shape is established during early development through the quantitative action of the CUP-SHAPED COTYLEDON2 (CUC2) gene that is negatively regulated by the co-expressed MICRORNA164A (MIR164A) gene. Compromised epigenetic regulation due to defective Polycomb Repressive Complex 2 (PRC2) function results in the transcriptional derepression of CUC2 but has no impact on CUC2 protein dynamics or early morphogenesis. We solve this apparent paradox by showing that compromised PRC2 function simultaneously activates a compensatory mechanism involving another member of the MIR164 gene family, the MIR164B gene. This mechanism dampens CUC2 protein levels, thereby compensating for compromised PRC2 function and canalizing early leaf morphogenesis. Furthermore, we show that this compensation mechanism is active under different environmental conditions. Our findings shed light on how the interplay between different types of transcriptional regulation can contribute to developmental robustness.
PSF Estimation and Image Restoration for Motion Blurred Images

Point spread function (PSF) estimation and image restoration algorithm are the hotspots In the research of motion blurred image restoration. In order to improve the efficacy of image restoration, an improved algorithm named quadric transforms (QT) method is proposed in this paper by analyzing the restoration process of motion blurred images. Firstly, Fourier transform and homomorphism transform are applied to the original motion blurred image, and then the Fourier transform and homomorphism transform are used again to the obtained spectrum image. Secondly, the motion blur direction is estimated by Radon transform. Thirdly, the motion blur length is found by differential autocorrelation operations. Finally, utilizing the estimated blur direction and blur length, the motion blurred image is restored by Wiener filtering. Experimental results show that the proposed QT method can get more accurate estimated motion blur angles than the primary transform (PT, that is, Fourier transform and homomorphism transform are used one time) method and can get better restored images under the meaning of peak signal to noise ratio (PSNR).
Undoped and in-situ B doped GeSn epitaxial growth on Ge by atmospheric pressure-chemical vapor deposition

In this letter, we propose an atmospheric pressure-chemical vapor deposition technique to grow metastable GeSn epitaxial layers on Ge. We report the growth of defect free fully strained undoped and in-situ B doped GeSn layers on Ge substrates with Sn contents up to 8%. Those metastable layers stay fully strained after 30 min anneal in N2 at 500 °C; Ge-Sn interdiffusion is seen at 500 °C but not at lower temperature. B is 100% active in the in-situ GeSn:B layers up to a concentration of 1.7 × 1019 cm−3. GeSn:B provides slightly lower Hall hole mobility values than in pure p-type Ge especially for low B concentrations.
Securing radars using secure wireless sensor networking

Radar sensors can be viewed as a limited wireless sensor network consisting of radar transmitter nodes, target nodes, and radar receiver nodes. The radar transmitter node sends a communication signal to the target node which then reflects it in a known pattern to the radar receiver nodes. This type of wireless sensor network is susceptible to the same types of attacks as a traditional wireless sensor network, but there is less opportunity for defense. The target nodes in the network are unable to validate the return signal, and they are often uncooperative. This leads to ample opportunities for spoofing and man-in-the-middle attacks. This paper explores some of the fundamental techniques that can be used against a limited wireless network system as well as explores the techniques that can be used to counter them.
Perturbation growth at the convective scale for CSIP IOP18

The Met Office Unified Model is run for a case observed during Intensive Observation Period 18 (IOP18) of the Convective Storms Initiation Project (CSIP). The aims are to identify the physical processes that lead to perturbation growth at the convective scale in response to model‐state perturbations and to determine their sensitivity to the character of the perturbations. The case is strongly upper‐level forced but with detailed mesoscale/convective‐scale evolution that is dependent on smaller‐scale processes. Potential temperature is perturbed within the boundary layer. The effects on perturbation growth of both the amplitude and typical scale length of the perturbations are investigated, and perturbations are applied either sequentially (every 30 minutes throughout the simulation) or at specific times.
Turbulence and Heat Transfer of a Hairpin Vortex Formed Behind a Cube in a Laminar Boundary Layer

We report numerical simulations of three-dimensional unsteady separated flow and heat transfer around a cube mounted in a laminar boundary layer. The separated shear layer rolls up and a hairpin vortex is generated periodically behind the cube. A horseshoe vortex is also formed ahead of the cube. Heat transfer around the cube is high due to the horseshoe vortex. Since the hairpin vortex interacts with horseshoe vortices downstream of the cube, the heat transfer increases around the center of the spanwise direction. The hairpin and horseshoe vortices generate local areas of high turbulence.
Tunable Diode Laser Absorption Spectroscopy Detection of N2O at 2.1 μm Using Antimonide Laser and InGaAs Photodiode

Tunable diode laser absorption spectroscopy detection of N2O around 2.1 μm is demonstrated by using a homemade InGaAsSb/AlGaAsSb MQW laser diode and an InGaAs wavelength extended photodiode. Details of the devices and the detection system are described. In the system, the laser is driven by low frequency pulses with long duration to form a wavelength scan around 4741 cm−1; the absorption information is obtained from the detected signal of the photodiode. By using a gas cell with 15 cm path length, a detection limit is estimated to be smaller than 0.2 Torr.
Study of poroelasticity material coefficients as response of microstructure

Using an asymptotic homogenization method, the effect of the porous medium microstructure on the values of poroelastic coefficients is studied in this paper. First, the Biot’s poroelasticity theory and general relations linking the macroscopic poroelastic coefficients with the averaged micromechanical solutions are recalled. Considering a variational formulation of appropriate boundary values problems stated for the representative volume element, microstructural parameters affecting the values of poroelastic coefficients are identified. In order to clarify specific roles of some relevant microstructure parameters, numerical investigations for some simplified pores geometries are presented. The numerical results obtained clearly show a strong dependence of the poroelastic coefficients on the internal geometry of pores as well as on the global porosity of the medium. In the last part, based on the micromechanics analysis, the definition of initial plastic yield condition for saturated porous media is introduced and a new interpretation of the effective stress concept in inelastic domain is proposed. Copyright © 2000 John Wiley & Sons, Ltd.
Sensitivity of the threshold displacement energy to temperature and time

Developing a fundamental understanding of radiation dam-age is key to the development of current and future materialsfor nuclear applications. The response of a given material toirradiation is dependent on a multitude of atomic processesoccurringonthenanoscale.Thecoalescenceoftheseprocessesproduce macroscopic changes in structural and chemicalpropertiesimpactingtheintendedfunctionalityofthematerial.One of the fundamental quantities that helps deﬁne amaterials radiation tolerance is the threshold displacementenergy
Calibration results for first NIF Kirkpatrick-Baez microscope

The Lawrence Livermore National Laboratory (LLNL) has been developing a novel X-ray imager for the National Ignition Facility (NIF) utilizing Kirkpatrick-Baez (KB) mirror geometry. A fully assembled mirror pack contains four KB optic pairs featuring cylindrical mirrors with custom-designed multilayer coatings. Multiple interchangeable mirror packs have been commissioned for various experimental campaigns, with high spatial resolution (< 5 μm) at the center of the field of view and 12× magnification. Tight tolerances on the grazing angles of the X-ray mirrors require precision alignment and assembly of each component via a coordinate measuring machine, and a comprehensive off-line calibration of the four KB channels at X-ray wavelengths. The main goals of the calibration campaign are to measure the performance of the multilayer, validate the assembly procedure by measuring the as-built spatial resolution and determine the best object to mirror pack distance (drive depth) of the microscope for fielding at NIF. We report on the results of this effort on the first fully assembled NIF KB X-ray imager.
Sound Propagation in Urban Areas

Outdoor sound communication systems for urban areas have been traditionally designed using relatively few sources of sound, located high above the buildings. Results have generally not been satisfactory because of sound attenuation in the atmosphere and diffraction by buildings. As an alternative, a block by‐block coverage system using many sound sources placed in the streets has been investigated. Extensive acoustical and meteorological field tests carried out in city streets showed that sound‐propagation conditions are generally favorable there. Typically, the mean wind and temperature gradients are small; consequently, no appreciable sound refraction effects were observed over distances of a city block or two when sound was propagated from a source 10–20 ft above the pavement. Reverberation from the building walls was not detrimental to speech intelligibility when a directive sound source was used with its axis oriented along the street. However, the intelligibility of speech received in a side street .
Piezoresistance Effect in Germanium and Silicon

Uniaxial tension causes a change of resistivity in silicon and germanium of both $n$ and $p$ types. The complete tensor piezoresistance has been determined experimentally for these materials and expressed in terms of the pressure coefficient of resistivity and two simple shear coefficients. One of the shear coefficients for each of the materials is exceptionally large and cannot be explained in terms of previously known mechanisms. A possible microscopic mechanism proposed by C. Herring which could account for one large shear constant is discussed. This so called electron transfer effect arises in the structure of the energy bands of these semiconductors, and piezoresistance may therefore give important direct experimental information about this structure.
Spoken word recognition in quiet and noise by native and non‐native listeners: Effects of age of immersion and vocabulary size.

In spoken word recognition, high‐frequency words with few and less frequently occurring minimal‐pair “neighbors” (lexically easy words) are recognized more accurately than low‐frequency words with many and more frequently occurring neighbors (lexically hard words). [Bradlow and Pisoni, J. Acoust. Soc. Am. ,106, 2074–2085 (1999)] found a larger “easy‐hard” word effect for non‐native than native speakers of English. The present study extends this work by specifically comparing word recognition by non‐native listeners with either earlier (age 10 or earlier) or later (age 14 or later) ages of immersion in an English‐speaking environment to that of native English speakers. Listeners heard six lists of 24 words, each composed of 12 lexically easy and 12 lexically hard target words in an open‐set word‐identification task. Word lists were presented in quiet and in moderate background noise. A substantially larger easy‐hard word effect was obtained only for the later learners, but a measure of oral vocabulary size .
Performance aspects of IEEE 802.11 wireless local-area networks

We are on the threshold of witnessing an explosion of portable and mobile terminals capable of sending and receiving multimedia traffic. Currently, the standard being worked out by the IEEE 802.11 committee to support wireless connectivity in the local area network appears to be the most promising one. IEEE 802.11 protocols support both scheduling and random access techniques operating simultaneously, called point coordination function (PCF) and distributed coordination function (DCF), respectively. In this paper, we study the interactions between PCF and DCF when voice and asynchronous data traffic needs to be supported. We investigate the dimensioning problems of various parameters, and provide the general rule of thumb of the default values.
A nonlinear polarization rotation-based linear cavity waveband switchable multi-wavelength fiber laser

A nonlinear polarization rotation (NPR)-based linear cavity waveband switchable multi-wavelength fiber laser is proposed and demonstrated. The NPR effect effectively induced intensity-dependent loss that can alleviate mode competition and result in multi-wavelength generation at room temperature. By adjusting the polarization controllers, the two wavebands in the region of 1530 and 1550 nm can be switched efficiently and the number of lasing lines can be also adjusted flexibly.
FEYNMAN RULES FOR ANY SPIN

The explicit Feynman rules are given for massive particles of any spin j, in both a 2j+1-component and a 2(2j+l)-component formalism. The propagators involve matrices which transform like symmetric traceless tensors of rank 2j; they are the natural generalizations of the 2×2 four-vector σ µ and 4×4 four-vector γ µ for \(j\frac{1}{2}\). Our calculation uses field theory, but only as a convenient instrument for the construction of a Lorentz-invariant S matrix. This approach is also used to prove the spin-statistics theorem, crossing symmetry, and to discuss T, C, and P.
Tracking maneuvering and bending extended target in cluttered environment

There has been a growing interest in tracking maneuvering point-targets since the last decade. Up to now however, no algorithm has been proposed for tracking maneuvering and bending extended target in clutter. We develop in this paper a new approach based on Interacting Multiple Model combined with a new fast point pattern matching algorithm to solve this new tracking problem. Simulation results for a bending target having four dynamic models and possibly tow point- patterns are given to illustrate the ability of this new approach to track a maneuvering and bending extended target in 2D space.