Miracle-dz/UniFAR-FTUs huggingface dataset:
On the semigroup approach to stochastic evolution equations

Bilinear stochastic evolution equations in Hilbert spaces with unbounded operators are studied by means of the semigroup approach. [BGeneral abstract results of regularity and well posedness are proved and applied to several more concrete problems, like classical variational equations, parabolic equations in non-variational form, non-homogeneous boundary value problems and feedback boundary control problems, and finally some equations which are not of parabolic type
Gaussian influence diagrams

An influence diagram is a network representation of probabilistic inference and decision analysis models. The nodes correspond to variables that can be either constants, uncertain quantities, decisions, or objectives. The arcs reveal probabilistic dependence of the uncertain quantities and information available at the time of the decisions. The influence diagram focuses attention on relationships among the variables. As a result, it is increasingly popular for eliciting and communicating the structure of a decision or probabilistic model. This paper develops the framework for assessment and analysis of linear-quadratic-Gaussian models within the influence diagram representation. The "Gaussian influence diagram" exploits conditional independence in a model to simplify elicitation of parameters for the multivariate normal distribution. It is straightforward to assess and maintain a positive semi-definite covariance matrix. Problems of inference and decision making can be analyzed using simple transformations to the assessed model, and these procedures have attractive numerical properties. Algorithms are also provided to translate between the Gaussian influence diagram and covariance matrix representations for the normal distribution.
COMPARISON EXERCISE FOR COMPUTATIONS OF TURBULENT NATURAL CONVECTION IN ENCLOSURES

Abstract A comparison is made between the numerical results obtained by 10 groups for a standard test case, which was defined for turbulent natural-convection flow in enclosures. The standard case considers air at a Rayleigh number of 5 × 1010in a square, differentially heated enclosure with adiabatic horizontal walls. The turbulence is modeled by a standard k-ϵ model. Some contributions find a strong grid dependence of the transition point in the vertical boundary layers, which prevents finding the grid-independent solution. In some contributions the boundary condition for e on the wall leads to convergence problems. The solution that shows the best agreement with half of the contributions is taken as the numerical reference solution.
Drag Coefficient of a Raftlike Domain Embedded in a Fluid Membrane Being a Near-Critical Binary Mixture

We consider a circular liquid domain in a flat fluid membrane surrounded by three-dimensional fluids, and assume that the membrane outside the domain is a two-dimensional near-critical binary fluid mixture. The membrane viscosity outside the domain is assumed to be uniform, irrespective of the local composition, and to be the same as that of the domain. Using the Gaussian free-energy functional, we show that the drag coefficient of the domain can be decreased by the preferential attraction between the domain and a component of the mixture, unlike that of a rigid sphere in a three-dimensional near-critical binary fluid mixture studied recently.
Incomplete interval fuzzy preference relations for supplier selection in supply chain management

AbstractIn the analytical hierarchy process (AHP), it needs the decision maker to establish a pairwise comparison matrix requires n(n–1)/2 judgments for a level with n criteria (or alternatives). In some instances, the decision maker may have to deal with the problems in which only partial information and uncertain preference relation is available. Consequently, the decision maker may provide interval fuzzy preference relation with incomplete information. In this paper, we focus our attention on the investigation of incomplete interval fuzzy preference relation. We first extend a characterization to the interval fuzzy preference relation which is based on the additive transitivity property. Using the characterization, we propose a method to construct interval additive consistent fuzzy preference relations from a set of n–1 preference data. The study reveals that the proposed method can not only alleviate the comparisons, but also ensure interval preference relations with the additive consistent property.
Predicting Volatility Based on Interval Regression Models

Considering the inferior volatility tracking capability of the point-data-based models, we propose using the more informative price interval data and building interval regression models for volatility forecasting. To characterize the heterogeneity of the market and the nonlinearity of volatility, we incorporated the heterogeneous autoregressive structure and the Markov regime switching structure in the benchmark interval regression model, respectively, and thus propose three extended models. Our empirical examination on S&P 500 index shows that: (1) the proposed interval regression models significantly improve the volatility prediction accuracy compared to the point-data-based GARCH model. (2) Incorporating the heterogeneous structure significantly improves the volatility prediction accuracy, and the corresponding models significantly outperform the range-based ECARR model. (3) Incorporating the Markov regime switching structure improves the prediction performance, and the improvement is significant when the heterogeneous structure is characterized. The above results are robust under different market conditions, including the extremely volatile periods.
From Dwarf Spheroidals to cDs: Simulating the Full Galaxy Population in a LCDM Cosmology

We use the combination of the very large Millennium and Millennium-II simulations to follow galaxy formation over a stellar mass range of more than five orders of magnitude throughout representative cosmological volumes. These are the first simulations to address the abundance and spatial distribution of galaxies ranging from cD’s down to dSph’s. We demonstrate that stronger feedback is needed than in previous models, epically at low mass, if the SDSS stellar mass function is to be matched in a LCDM universe. Models which satisfy this constraint also reproduce the observed abundance of faint dwarfs around the Milky Way and M 31. Only the very faintest objects are significantly affected by the treatment of reionisation. Our model can reproduce most galaxy properties in the local Universe. Problems remain with respect to the stellar age distributions and kinematics of dwarfs.
Thermal modifications of internal quantum efficiencies in the near IR [Si solar cells]

A planar nanostructure inserted in the emitter of a Si solar cell modifies the photovoltaic (PV) conversion performance. In this paper, the authors report a large internal quantum efficiency (IQE) improvement in the near IR (>900 nm) for a series of multi-interface novel device (or MIND) solar cells. The IQE modification can result from increased IR absorption, band-gap narrowing and photogeneration involving thermal phonons and extrinsic energy levels due to post-implantation point defects under stress and might still be improved by an adequate thermal treatment. They show that the near IR modification changes with ambient temperature. This could be related to an evolution of the phonon energy distribution which increases the probability of carrier generation with the participation of phonons.
TRANSFORM ANALYSIS FOR POINT PROCESSES AND APPLICATIONS IN CREDIT RISK

This paper develops a formula for a transform of a vector point process with totally inaccessible arrivals. The transform is expressed in terms of a Laplace transform under an equivalent probability measure of the point process compensator. The Laplace transform of the compensator can be calculated explicitly for a wide range of model specifications, because it is analogous to the value of a simple security. The transform formula extends the computational tractability offered by extant security pricing models to a point process and its applications, which include valuation and risk management problems arising in single‐name and portfolio credit risk.
Edge localized modes and the pedestal: A model based on coupled peeling–ballooning modes

A model based on magnetohydrodynamic (MHD) stability of the tokamak plasma edge region is presented, which describes characteristics of edge localized modes (ELMs) and the pedestal. The model emphasizes the dual role played by large bootstrap currents driven by the sharp pressure gradients in the pedestal region. Pedestal currents reduce the edge magnetic shear, stabilizing high toroidal mode number (n) ballooning modes, while at the same time providing drive for intermediate to low n peeling modes. The result is that coupled peeling–ballooning modes at intermediate n (3<n<20) are often the limiting instability which constrains the pedestal and triggers ELMs. These modes are characterized in shaped tokamak equilibria using an efficient new numerical code, and simplified models are developed for pedestal limits and the ELM cycle. Results are compared to several experiments, and nonideal MHD effects are briefly discussed.
Exchange Anisotropy in MBE-Grown MnPt/NiFe Bilayers.

Exchange anisotropy in MnPt(30 nm)/NiFe(5 nm) bilayers was investigated for films grown by the MBE method on SrTiO3(100) substrates at temperatures of Tg = 25°C, 100°C, 200°C, and 300°C. In-situ reflection high-energy electron diffraction observations and ex-situ X-ray diffraction measurements revealed that the MnPt layers grown on NiFe(100) have (100) orientations for Tg = 25°C and 100°C, while they have random orientations for Tg = 200°C and 300°C. Superlattice lines due to the formation of a CuAu-I type ordered structure were observed during the growth of the MnPt layer for all growth temperatures. The (100)-oriented MnPt/NiFe bilayer films were found to have an exchange anisotropy field (Hex) of 220 Oe (corresponding to an exchange anisotropy energy of J = ∼0.09 erg/cm2) and a coercivity (Hc) of ∼ 43 Oe. On the other hand, the films with random orientation showed almost zero Hex and a rather large Hc of ∼ 600 Oe.
On reconstruction of a cavity in a linearized viscoelastic body from infinitely many transient boundary data

In this paper, a reconstruction problem of a cavity in a linearized viscoelastic body from dynamical boundary data is considered. As a result, we establish a formula extracting three kinds of information about the unknown cavity: the support function, the distance from an outer point of the body and the minimum radius of the open ball including the cavity centered at a point, with infinitely many sets of the boundary data. In the formula, observation time can be taken to be arbitrary.
A simple passive cooling structure and its heat analysis for 500/spl times/ concentrator PV module

A new and simple module structure for the 500/spl times/ concentrator module made by printed epoxy and a copper sheet on aluminum plate was proposed. The heat analysis was done and showed that around a 10 degree rises at the surface of the cell compared to normal irradiated flat-plane was expected without the help of classical heat sinks. An outdoor test was done and confirmed its cooling performance.
Coherence vortex with orbital angular coherence momentum and wave-particle duality in correlation function

Under the paraxial approximation for the propagation of vectorial coherence function, we made a theoretical investigation into the mechanism of the orbital angular coherence momentum associated with a coherence vortex. By controlling the irradiance distribution of an extended quasi-monochromatic spatially incoherent source with a spatial light modulator, we examined the phase structure of coherence function and investigated the birth and evolution of the orbital angular coherence momentum. Some properties related to the fractional coherence vortex, such as a wave particle-like duality of coherence function, are also investigated both theoretically and experimentally for the first time.
Lattice wave digital filters with simultaneous conditions on amplitude and phase

Simultaneous amplitude and phase approximation for low-pass lattice wave digital filters has been developed based on the hidden relationship between the amplitude and phase characteristics of a nonminimum-phase transfer function. The iterative approximation process is based on the factorization of the nonminimum-phase transfer function into a minimum-phase and an all-pass part. Separate algorithms are used to design the minimum-phase and the all-pass part, and these algorithms are carried out alternately. The approximation method results in filters with equiripple amplitude both in the passband and the stopband while the phase characteristic is equiripple with respect to a linear phase. A design example shows the properties of these filters and illustrates the efficiency of the proposed method. <<ETX>>
Geostrophic Vortex Dynamics

Abstract : By generalizing the method of contour dynamics to the quasigeostrophic two layer model, we have proposed and solved a number of fundamental problems in the dynamics of rotating and stratified vorticity fields. A variety of rotating and translating potential vorticity equilibria (V- states) in one and two layers have been obtained, shedding new light on potential vorticity dynamics in the geostrophic context. In particular, the equivalent barotropic model is shown to be a singular limit of the two-layer model for scales large compared to the radius of deformation. The question of coalescence of two vortices in the same layer (merger) and in different layers (alignment) is studied in detail. Critical initial separation distances for coalescence are numerically established as functions of the radius of deformation and the relative thickness of the layers at rest. The connection between coalescence and the existence of stable rotating doubly-connected V- states is shown to be an illuminating generalization of the Euler results. The question of filamentation of two-dimensional vorticity interfaces is addressed from a new geometrical perspective. The analysis of the topology of the stream function in a frame of reference rotating with the instantaneous angular velocity of the vorticity distribution (the corotating frame) is shown to yield new powerful insights on the nonlinear evolution of the vorticity field. Theses. (AW)
Optical Properties of CdS/PVA Nanocomposite Films Synthesized using the Gamma-Irradiation-Induced Method

Monodispersed spherical CdS nanoparticles embedded into polyvinyl alcohol (PVA) films are synthesized by using an in-situ gamma-irradiation-induced method. The formation mechanism of CdS nanoparticles capped by two united cells of PVA is purposed by means of surrounding the CdS nanoparticles with OH bonds of the PVA chain. CdS nanoparticles are found to possess an unusual orthorhombic structure in monoclinic crystalline PVA. The polymer matrix affords protection from agglomeration and controls the particle size. It is found that the distribution of the prepared nanoparticles increases and a narrower size distribution is observed when the gamma radiation is varied from 10 to 50 kGy. While the average size of the nanoparticles is found to be less affected by the variation of the gamma radiation doses. The size range of the synthesized nanoparticles is 14±1 nm. The optical absorption spectra of synthesized CdS nanoparticles in a polymer matrix reveal the blue shift in the band gap energy with respect to CdS bulk materials owing to quantum confinement effect. The photoluminescence study of nanocomposite films shows the green emission arising from the crystalline defects.
Wall friction and turbulence dynamics in decelerating pipe flows

Wall shear stresses in decelerating pipe flows are studied using a well-established CFD code developed specifically for modelling unsteady turbulent flows. The suitability of the turbulence model used was demonstrated previously and re-confirmed by comparison with recent experimental data. The response of the wall shear stress to the deceleration is shown to exhibit features in common with responses in accelerating flows, but also indicates strong differences. Turbulence delays are shown to be important, causing, in effect, a frozen-turbulence response at early times. Also, flow reversal and increasing turbulence timescales prevent the development of asymptotic conditions at larger times. It is demonstrated that, at intermediate times, the instantaneous wall shear stress may be either larger or smaller than the corresponding quasi-steady value, thereby explaining features of existing experimental data that were previously regarded as conflicting. It is shown that the amplitude and timing of key features of the wall shear stress history can be correlated by means of a single non-dimensional parameter.
High-Frequency Transient Eddies and Blocking

Abstract In this paper we investigate the role of high-frequency transient eddies in the maintenance of the blocking high which occurred over Europe on 16-25 February 1979. Time-filtering is used to decompose the atmospheric large-scale flow into contributions from high-frequency and low-frequency fluctuations. the separation being roughly at the period of six days. The net effect on the ten-day mean flow of the high-frequency cyclone-scale eddies is studied using several methods. The vorticity flux convergence associated with the high-frequency eddies, although small in comparison with the dominating terms in the vertically averaged vorticity equation, appears to be important for counterbalancing the effects of the time-mean surface stress, especially in the vicinity of the storm tracks. The eddies are thus important for the distribution of the time-mean surface pressure. Also the “tendency method” of illustrating the eddy effects supports this view. The hemispheric average of the barotropic energy conve.
Non-relativistic treatment of diatomic molecules interacting with a generalized Kratzer potential in hyperspherical coordinates

We investigate solutions of a non-relativistic wave equation in hyperspherical coordinates for a diatomic molecule system interacting with a generalized Kratzer potential. Rovibrational eigenvalues and corresponding wavefunctions of non-relativistic diatomic molecules have been determined within the framework of the asymptotic iteration method. Certain fundamental conditions for the applications of the asymptotic iteration method, such as a suitable asymptotic form for the wave-function and the termination condition for the iteration process, are discussed. N-dimensional bound state eigenfunction solutions used in studying the dynamical variables of diatomic molecules are obtained in terms of a confluent hypergeometric function and a generalized Laguerre polynomial. This systematic approach is tested by calculating the rovibrational energy spectra of hydrogen and sodium chloride molecules.
Local generalized method of moments estimation based on kernel weights: An application to panel data

This paper presents and applies a local generalized method of moments (LGMM) estimator for regression functions. The method is an extension of previous results obtained by Gozalo and Linton. The LGMM estimation procedure can be applied to estimate a mean regression function and its derivatives at an interior point x , without making explicit assumptions about its functional form. The method has been applied to estimate dynamic models based on panel data.
Phase and coherence extraction from a phased vertical cavity laser array

The relative coherence and phase are extracted from two-element, coherently coupled, vertical cavity surface emitting laser arrays. The array elements are defined optically by a photonic crystal pattern and electrically by ion implantation. We obtain the near and far fields experimentally under varying current injection. The Fraunhofer approximation is used to simulate propagation from the near to far field. The phase and coherence are extracted as fitting parameters to match the experimental and propagated far field patterns. The phase and coherence will aid in future array designs and in elucidating the phase-shifting mechanism.
Blow‐up profile for radial solutions of the nonlinear heat equation

Assuming that the maximal classical solution u of ut Δu = u p on B(0,R) has, at time Tmax ,ab low-up setB(u) that is not the singleton {0}, we prove thatkuk Lq () blows up for all q> (p 1)=2, the energy blows up and u blows up completely after Tmax in the sense of Baras-Cohen (equivalent to the fact that there is no weak solution extending u beyond Tmax). We also study this type of blow-up through numerical experiments as well as degenerate blow-up.
Palindromes dans les progressions arithmétiques

HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L’archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d’enseignement et de recherche français ou étrangers, des laboratoires publics ou privés. Palindromes dans les progressions arithmétiques Sylvain Col
Growth of GaAs‐Ga1−xAlxAs over preferentially etched channels by molecular beam epitaxy: A technique for two‐dimensional thin‐film definition

In this paper, studies of the molecular beam epitaxy (MBE) of GaAs‐Ga1−xAlxAs multilayer structures over preferentially etched channels on GaAs substrates are described. It is found that the growth characteristics with MBE are entirely different from those obtained from similar experiments when LPE is used. Results obtained indicate that this etch‐and‐fill technique using MBE as the growth process should be particularly useful in fabricating injection lasers, laser arrays, and integrated optics components which require planar definition.
Wall accumulation of self-propelled spheres

The dynamics of a self-propelled Brownian sphere confined between two planar hard walls is investigated by computer simulations and analytic solutions of the corresponding Fokker-Planck equation. It is shown that an accumulation of self-propelled particles, often linked to the hydrodynamic dipole interaction, can be already obtained from the combination of Brownian motion and self-propulsion. The surface excess is calculated as a function of particle velocity, wall separation, and translational and rotational diffusion coefficients. In limits of narrow channels or small propulsion velocities, analytical solutions and numerical results are in excellent agreement.
Lateral Hydrogen Diffusion at p-GaN Layers in Nitride-Based Light Emitting Diodes with Tunnel Junctions

We demonstrated lateral Mg activation along p-GaN layers underneath n-GaN surface layers in nitride-based light emitting diodes (LEDs) with GaInN tunnel junctions. A high temperature thermal annealing was effective for the lateral Mg activation when the p-GaN layers were partly exposed to an oxygen ambient as etched sidewalls. The activated regions gradually extended from the etched sidewalls to the centers with an increase of annealing time, observed as emission regions with current injection. These results suggest that hydrogen diffuses not vertically thorough the above n-GaN but laterally through the exposed portions of the p-GaN. The lowest voltage drop at the GaInN tunnel junction was estimated to be 0.9 V at 50 mA with the optimized annealing condition.