Miracle-dz/UniFAR-FTUs huggingface dataset:
A novel adaptive differential evolution algorithm with application to estimate kinetic parameters of oxidation in supercritical water

A new version of differential evolution (DE) algorithm containing the adaptive mutation and crossover operators, named adaptive differential evolution (ADE), is proposed. In ADE, the control parameters of ADE are generated for each individual and the value of the parameters are based on individual's current generation number and parent's fitness value. With population evolution, the ADE algorithm gradually changes from being exploratory at the early stages to being exploitationary at the later stages. At the same time, in certain generations, low fitness individuals or high fitness individuals are assigned with small parameters to accelerate the convergence of these individuals. The experiments conducted show that the ADE generally outperforms the original DE algorithm and other existing self-adaptive DE algorithms for 11 benchmark functions. Furthermore, ADE is applied to develop the global kinetic model of the 2-chlorophenol oxidation in supercritical water, and satisfactory results are obtained.
Applications of the Fourier-Wiener transform to differential equations on infinite-dimensional spaces. I

Let (H, i, B) be an abstract Wiener space andp, be the Wiener measure on B with variance t. Let [B] be the complexification of B and S>a be the class of exponential type analytic functions defined on [B]. We define the Fourier-Wiener c-transform for any/in &a by
Exact solutions and doubly efficient approximations of jump-diffusion itô equations

This paper presents exact solutions to an unsolved class of jump-diffusion stochastic differential equations and derives efficient numerical schemes for the general non-linear cases. It is proved that even the second order mean square efficient schemes may not be second order efficient in the weak sense. The generator and Taylor expansion in the expectationssemi-group are verified under weaker conditions and applied to derive new doubly efficient schemes which are proved to converge with the best possible order rate in both senses. A class of direct jump-adapted schemes are als o presented. Comparative simulations are consistent with the findings.
Simplified adaptive volume scattering model and scattering analysis of crops over agricultural fields using the RADARSAT-2 polarimetric synthetic aperture radar imagery

Abstract. A simplified adaptive volume scattering model (SAVSM) for RADARSAT-2 polarimetric synthetic aperture radar (PolSAR), based on the n’th power sine and cosine functions, is developed to characterize the changes in crop phenology within the growing season. A three-component model-based decomposition (TCMD) with SAVSM is also implemented with the non-negative eigenvalue decomposition. Multitemporal RADARSAT-2 data acquired in southwestern Ontario, Canada, are used for validating the proposed TCMD-SAVSM. The TCMD-SAVSM is first compared with the adaptive model-based decomposition proposed by Arii et al. in which ∇fv is set to 0.01, demonstrating that TCMD-SAVSM not only consumes much less computing time but also the decomposed surface and double-bounce components are also more representative of the land cover reality. Using the percentage of power of the remainder matrix <0.001 as the evaluation criterion, the SAVSM achieved the best performance in corn, soybean and wheat fields compared with other popular volume scattering models (VSMs), with the highest mean and lowest standard deviation. It suggests that the SAVSM is a suitable VSM for describing seasonal changes of crop fields. Last, the decomposed surface, double-bounce and volume scattering components of wheat, soybean and corn at various growth stages are analyzed at the individual crop level, and the results demonstrate that their variations are in concert with the crop’s phenological development.
Predicting Monthly and Annual Air Temperature Characteristics in North Carolina

Abstract Monthly and annual air temperature characteristics and their relationship to elevation and latitude were examined for North Carolina. Regression equations to predict monthly and annual mean temperatures and mean temperature ranges were derived using 57 stations with a 30-yr record of temperatures. A procedure for predicting maximum and minimum temperatures was also developed. An estimate of the temperature lapse rates due to elevation and latitude was proposed. Regression diagnostics, as well as validation analysis against 25 independent stations, indicated that the proposed equations reliably predict monthly and annual air temperature characteristics in North Carolina.
In‐plane aligned YBa2Cu3O7−x thin films deposited on polycrystalline metallic substrates

C‐axis oriented YBa2Cu3O7−x thin films are conventionally obtained on polycrystalline substrates, but a‐ and b‐axes are randomly distributed. Due to the weak links at the high‐angle grain boundaries in the a–b plane, the critical current density (Jc) are comparatively low, from 103 to 104 A/cm2 (77 K, 0 T), and the Jc decreases in magnetic field in a manner similar to bulk YBa2Cu3 O7−x samples. To reduce weak links at the high‐angle grain boundaries, biaxially oriented buffer layers of yttrium stabilized zirconia (YSZ) were formed on polycrystalline, Ni‐based alloy by ion‐beam assisted deposition (IBAD), and subsequently the a–b plane aligned YBa2Cu3 O7−x film was deposited by laser ablation. Jc of 2.5×105 A/cm2 (77 K, 0 T) and 2.2×104 A/cm2 (77 K, 8.0 T) were obtained. A new method to prevent intergranular weak links has been developed for potential applications using practical polycrystalline substrates.
Interaction of ring current and radiation belt protons with ducted plasmaspheric hiss: 1. Diffusion coefficients and timescales

Protons that are converted into the inner magnetosphere in response to enhanced magnetic activity can resonate with ducted plasmaspheric hiss in the outer plasmasphere via an anomalous Doppler-shifted cyclotron resonance. Plasmaspheric hiss is a right-hand-polarized electromagnetic emission that is observed to fill the plasmasphere on a routine basis. When plasmaspheric hiss is confined within field-aligned ducts or guided along density gradients, wave normal angles remain largely below 45°. This allows resonant interactions with ions at typical ring current and radiation belt energies to take place. Such field-aligned ducts have been observed both within the plasmasphere (Kozyra et al., 1987a; Koons, 1989) and in regions outside of the plasmasphere (Chan and Holzer, 1976). Wave intensities are estimated using statistical information from studies of detached plasma regions (Chan et al., 1974). Diffusion coefficients are presented for a range of L shells and proton energies for a fixed wave distribution. Harmonic resonances in the range n = ±100 are considered in order to include interactions between hiss at 100 Hz to 2 kHz frequencies, and protons in the energy range between ∼10 keV and 1000 keV. Diffusion timescales are estimated to be of the order or tens of days and comparable to or shorter than lifetimes for Coulomb decay and charge exchange losses over most of the energy and spatial ranges of interest.
Single-phase computational fluid dynamics applicability for the study of three-dimensional flow in 5′ 5 rod bundles with spacer grids

Spacer grids play an important role in pressurized water reactor (PWR) fuel assembly in that they have significant influence on the thermal-hydraulic characteristics of the reactor core. But so far, the numerical studies are performed without regarding dimple and spring of spacer grids, just considering mixing vane. Moreover, these studies use k-ɛ turbulence model without considering the suitability of the other turbulence models upon the different spacer grids flow. A study is carried out to understand the 3-D single-phase flow in AFA-2G 5×5 rod bundles with spacer grids based on numerical method. In order to investigate the suitability of different turbulence models, k-ɛ model and k-ω model, the influence of different parts of spacer grid on the fluid flow is also predicted. By using second-order upwind scheme, hybrid grids technique, and improved SIMPLEC algorithm, the Reynolds averaged mass conservation and momentum conservation equations are solved, and the pressure and velocity field of flow are obtained. The numerical simulation results are compared with experiment results and the agreement is satisfactory. The simulation results show the influences of the spring, dimple and mixing vane, and the different characteristics of the k-ɛ model and k-ω model. Comparing with the experiment results, the simulation results suggest that the k-ω model is suitable for the simulation of the rod bundle flow with spacer grids; the spring and dimple are the main causes of the pressure loss in the spacer grid channel. The friction coefficient of the channel with spring and dimple is 1.5 times the coefficient of the channel with the vane. These results are beneficial to enhance the simulation ability of spacer grids flow and optimization design ability of spaces grid.
Determination of Microphonic Generator Transfer Characteristic from Modulation Data

Two methods are described for determination of the microphonic generator transfer characteristic using data from bitonal stimulation experiments. In one method, the filtered high‐frequency microphonic output component is measured at the extreme points of the modulation envelope for a sequence of intensity levels of the lower‐frequency component. This method is applied to data derived from a modulation test procedure making use of a wide range of test intensities for both the high‐ and low‐frequency components and also to data generated in a test using a single sequence of stimuli with increasing intensity of the lower frequency. In a second method, the modulation envelope of the higher‐frequency microphonic response to a bifrequency acoustic stimulus is used to determine a segment of the generator transfer characteristic. The results of a sequence of determinations for different lower‐frequency intensities show good agreement with each other and with the transfer characteristic derived by the first method. However, the second method shows that there is an appreciable level‐dependent hysteresis, the mechanism for which has not been determined. The transfer characteristics determined would give rise to a pronounced dc rectification component in the direction of positive summating potential.
Large scale magnetic fields of our Galaxy

Abstract Large-scale magnetic fields in the Galactic disk have been revealed by distributions of pulsar rotation measures (RMs) and Zeeman splitting data of masers in star formation regions, which have several reversals in arm and interarm regions. Magnetic fields in the Galactic halo are reflected by the antisymmetric sky distribution of RMs of extragalactic radio sources, which have azimuthal structure with reversed directions below and above the Galactic plane. Large-scale magnetic fields in the Galactic center probably have a poloidal and toroidal structure.
On the theory of visco-elasticity: a thermodynamical treatment of visco-elasticity, and some problems of the vibrations of visco-elastic solids

The problem of the damping of vibrations in a solid which is imperfectly elastic was introduced to me by Professor E. A. MILNE. Sir CHARLES SHERRINGTON had asked Professor MILNE for his assistance in the analysis of an experiment which Dr. J. C. ECCLES was performing at the Oxford Physiological Laboratories, on the damping of forced longitudinal vibrations in a muscle. It was proposed, in the first place, to assume that in this experiment muscle displays dynamical properties of the same character as a non-living solid—a similarity between the dynamical behaviour of muscle and that of rubber and glass had already been noticed. According to this view the damping of vibrations in the muscle would be due to the “ imperfectness of elasticity ” of the muscle; and in order to work out the analysis of the experiment, it is necessary to know the expression for the tension at any point of the muscle at any instant during its straining . An examination of the scientific literature dealing with the imperfectness of elasticity of solids did not indicate an immediate solution of the problem.
Four- and three-state rock-paper-scissors games with long-range selection

Considering the effect of a long-range selection, we investigate the crossover to extinction of species and the oscillation behaviors in the four- and three-state models of the rock-paper-scissors (RPS) game extensively on a two-dimensional lattice. It is found that the selection in a long-range leads to the destruction of species coexistence in the four-state RPS game model but it cannot induce the extinction of species nearly and even promotes the coexistence of three species when a long-range migration occurs in the three-state RPS game model. Through the simulations of spatiotemporal patterns, it is found that there are two different mechanisms to result in the extinction of species in two models. In the four-state model, a phase separation occurs and there are some vortices where three species coexist and dominate each other cyclically. Through a long-range selection, the vortices are eliminated to cause the destruction of species coexistence. In the three-state model, the spreading of species takes a key role in the crossover to extinction. When one of the species spreads rapidly, a giant cluster forms and the system becomes unstable and sensitive to the stochastic noise and the destruction of the species coexistence takes place. As the selection range is not too large, it can inhibit the formation of the giant cluster and then promotes the coexistence probability in the three-state model.
A Comprehensive Review of Self-Healing Polymer, Metal, and Ceramic Matrix Composites and Their Modeling Aspects for Aerospace Applications

Composites can be divided into three groups based on their matrix materials, namely polymer, metal and ceramic. Composite materials fail due to micro cracks. Repairing is complex and almost impossible if cracks appear on the surface and interior, which minimizes reliability and material life. In order to save the material from failure and prolong its lifetime without compromising mechanical properties, self-healing is one of the emerging and best techniques. The studies to address the advantages and challenges of self-healing properties of different matrix materials are very limited; however, this review addresses all three different groups of composites. Self-healing composites are fabricated to heal cracks, prevent any obstructed failure, and improve the lifetime of structures. They can self-diagnose their structure after being affected by external forces and repair damages and cracks to a certain degree. This review aims to provide information on the recent developments and prospects of self-healing composites and their applications in various fields such as aerospace, automobiles etc. Fabrication and characterization techniques as well as intrinsic and extrinsic self-healing techniques are discussed based on the latest achievements, including microcapsule embedment, fibers embedment, and vascular networks self-healing.
The origin of magnetism on the upper main sequence

We consider the incidence of magnetism in main-sequence stars with mainly radiative envelopes. We propose that the small fraction, which increases with mass, of stars which are magnetic can be explained if towards the end of the formation process, after the stars have developed a substantial radiative envelope, a correspondingly small fraction of stars merge. Such late mergers would produce a brief period of strong differential rotation and give rise to large-scale fields in the radiative envelopes. Such late mergers can also account for the lack of close binaries among these stars.
On decentralized estimation

A multilevel scheme is proposed to construct decentralized estimators for large linear systems. The scheme is numerically attractive since only observability tests of low-order subsystems are required. Equally important is the fact that the constructed estimators are reliable under structural perturbations and can tolerate a wide range of non-linearities in coupling among the subsystems.
Verification of Statistical Turbulence Models in Aerodynamic Flows

Computational fluid dynamics (CFD) is a tool that is commonly used in industry and academia. Engineers and scientists are sometimes apprehensive about the use of CFD due to inconsistencies and/or errors in results obtained with different software packages for the same flow cases. As a result, efforts are being made to ensure that there is uniformity among results of flow simulations produced by the computer programs. The current research makes a contribution to the verification of an opensource CFD toolbox known as OpenFOAM. In doing so, flow results for two benchmark flow cases obtained with OpenFOAM are compared with the results obtained with high-accuracy NASA CFD codes CFL3D and FUN3D. The benchmark cases are the zero pressure gradient boundary layer of flow over a flat plate and a two-dimensional bump in a channel. A number of flow profiles obtained with NASA’s definitions of “standard” versions of the Spalart-Allmaras, Shear Stress Transport, and k-ω turbulence models are compared with their CFL3D and FUN3D
Automatic method for synchronizing workpiece frames in twin-robot nondestructive testing system

The workpiece frames relative to each robot base frame should be known in advance for the proper operation of twin-robot nondestructive testing system. However, when two robots are separated from the workpieces, the twin robots cannot reach the same point to complete the process of workpiece frame positioning. Thus, a new method is proposed to solve the problem of coincidence between workpiece frames. Transformation between two robot base frames is initiated by measuring the coordinate values of three non-collinear calibration points. The relationship between the workpiece frame and that of the slave robot base frame is then determined according to the known transformation of two robot base frames, as well as the relationship between the workpiece frame and that of the master robot base frame. Only one robot is required to actually measure the coordinate values of the calibration points on the workpiece. This requirement is beneficial when one of the robots cannot reach and measure the calibration points. The coordinate values of the calibration points are derived by driving the robot hand to the points and recording the values of top center point(TCP) coordinates. The translation and rotation matrices relate either the two robot base frames or the workpiece and master robot. The coordinated are solved using the measured values of the calibration points according to the Cartesian transformation principle. An optimal method is developed based on exponential mapping of Lie algebra to ensure that the rotation matrix is orthogonal. Experimental results show that this method involves fewer steps, offers significant advantages in terms of operation and time-saving. A method used to synchronize workpiece frames in twin-robot system automatically is presented.
Hopf Bifurcation of an Improved SLBS Model under the Influence of Latent Period

A model applicable to describe the propagation of computer virus is developed and studied, along with the latent time incorporated. We regard time delay as a bifurcating parameter to study the dynamical behaviors including local asymptotical stability and local Hopf bifurcation. By analyzing the associated characteristic equation, Hopf bifurcation occurs when the time delay passes through a sequence of critical values. A formula for determining the direction of the Hopf bifurcation and the stability of bifurcating periodic solutions is given by using the normal form method and center manifold theorem. Finally, illustrative examples are given to support the theoretical results.
Critical frequency control in harmonic quantum Brownian motion

The dissipative effects of a quantum harmonic oscillator, initially set in a coherent state and linearly coupled to a continuous distribution of frequency modes, are analyzed over long time scales in relation to the behavior of the spectral density near an arbitrary band gap, arbitrarily shaped at the higher frequencies. The reservoir is initially set either in the vacuum state or in continuous distributions of coherent states. These distributions are arbitrarily shaped at high frequencies and structured in sub- or super-ohmic configurations near an arbitrary band gap frequency. Similarly to certain decoherence processes of a qubit, critical conditions emerge, such that arbitrarily slow inverse power law relaxations of the expectation values of the observables, are obtained by approaching the boundary between the sub- and the super-ohmic regimes. Also, in such critical conditions, a trapping of the number of excitations appears in the super-ohmic regime. The technique of critical frequency control, emerging in the scenario of the environment-induced decoherence of a qubit via the reservoir engineering approach, is extended to the harmonic quantum Brownian motion.
Mechanisms behind green photoluminescence in ZnO phosphor powders

We explore the interrelationships between the green 510 nm emission, the free‐carrier concentration, and the paramagnetic oxygen‐vacancy density in commercial ZnO phosphors by combining photoluminescence, optical‐absorption, and electron‐paramagnetic‐resonance spectroscopies. We find that the green emission intensity is strongly influenced by free‐carrier depletion at the particle surface, particularly for small particles and/or low doping. Our data suggest that the singly ionized oxygen vacancy is responsible for the green emission in ZnO; this emission results from the recombination of a photogenerated hole with the singly ionized charge state of this defect.
Wrinkled polypyrrole electrode for electroactive polymer actuators

As an electrode for a bending-electrostrictive polyurethane actuator, we prepared a wrinkled polypyrrole electrode, expecting the following two effects because the wrinkled electrode could easily elongate by smoothing the wrinkles: (1) conductivity of the electrode would not decrease with the field-induced surface elongation of the actuator, and (2) the electrode would not constrain the actuation. The wrinkled electrode was prepared through in situ deposition of polypyrrole onto the polyurethane elastomer film that was being uniaxially drawn. After the deposition, the film was released from the drawing to make the electrode wrinkle. The conductivity of the wrinkled electrode did not decrease at elongation rates less than 40%. The bending actuation of the polyurethane film with the wrinkled electrode was improved more than twice that as compared with an unwrinkled one. In addition, doping the polyurethane with sodium acetate also improved the actuation. By these improvements, the bending actuation reached .
Resistive ballooning modes in an axisymmetric toroidal plasma with long mean free path

Tokamak devices normally operate at such high temperatures that the resistive fluid description is inappropriate. In particular, the collision frequency may be low enough for trapped particles to exist. However, on account of the high conductivity of such plasmas, one can identify two separate scale lengths when discussing resistive ballooning modes. By describing plasma motion on one of these, the connection length, in terms of kinetic theory the dynamics of trapped particles can be incorporated. On the resistive scale length, this leads to a description in terms of modified fluid equations in which trapped particle effects appear. The resulting equations are analyzed and the presence of trapped particles is found to modify the stability properties qualitatively.