Miracle-dz/UniFAR-FTUs huggingface dataset:
Fabrication of nano-patterned sapphire substrates and their application to the improvement of the performance of GaN-based LEDs

Nano-patterned sapphire substrates (NPSSs) were fabricated by a chemical wet etching technology using nano-sized SiO2 as masks. The NPSS was applied to improve the performance of GaN-based light emitting diodes (LEDs). GaN-based LEDs on NPSSs were grown by metal organic chemical vapour deposition. The characteristics of LEDs grown on NPSSs and conventional planar sapphire substrates were studied. The light output powers of the LEDs fabricated on NPSSs were considerably enhanced compared with that of the conventional LEDs grown on planar sapphire substrates.
Coupled damage and plasticity modelling in transient dynamic analysis of concrete

In a concrete structure subjected to an explosion, for example a concrete slab, the material is subjected to various states of stress which lead to many modes of rupture. Closer to the explosive, a state of strong hydrostatic compression is observed. This state of stress produces an irreversible compaction of the material. Away from the zone of explosion, confinement decreases and the material undergoes compression with a state of stress, which is slightly triaxial. Finally, the compression wave can be reflected on a free surface and becomes a tensile wave, which by interaction with the compression wave, produces scabbing. We present, in this paper, a model aimed at describing these three failure modes. It is based on visco‐plasticity and rate dependent damage in which a homogenization method is used in order to include the variation of the material porosity due to compaction. The model predictions are compared with several experiments performed on the same concrete. Computations of split Hopkinson tests on confined concrete, a tensile test with scabbing, and an explosion on a concrete slab are presented. Copyright © 2001 John Wiley & Sons, Ltd.
Distribution functions and log-concavity

This paper presents a collection of log-concavity results of one-dimensional cumulative distribution functions (cdf's) F(x,ϑ) and the related functions . in both x∈R or x∈Z and θ ∈ Θ. where R denotes the real line and Z the set of integers. We give a review of results available in the literature and try to fill some gaps in this field. It is well-known that log-concavity properties in x of a density f carry over to F. [Fbar]. and Jc in the continuous and discrete case. In addition, it will be seen that the log-concavity of g(y) = f(ey ) in y for a Lebesgue density f with f(x) = 0 for x < 0 implies the log-concavity of F. This criterion applies to many common densities. Moreover, a convex statistic T defined on R" is shown to have a log-concave cdf whenever the underlying n-dimensional Lebesgue density h is log-concave. A slight generalization of the approach in Das Gupta & Sarkar (1984) is used to establish a connection between log-concavity in x of probability densities f or cdf s F and log-concavity of .
Location of Several Outliers in Multiple-Regression Data Using Elemental Sets

The outlying tendency of any case in a multiple regression of p predictors may be estimated by drawing all subsets of size p from the remaining cases and fitting the model. Each such subset yields an elemental residual for the case in question, and a suitable summary statistic of them can be used as an estimate of the case's outlying tendency. We propose two such summary statistics: an unweighted median, which is of bounded influence, and a weighted median, which is more efficient but less robust. The computational load of the procedure is reduced by using random samples in place of the full set of subsets of size p. As a byproduct the method yields useful information on the influence (or leverage) of cases and the mutual masking of high leverage points.
On the universality of the two-point galaxy correlation function

The behavior of the two-point galaxy correlation function in volume-limited subsamples of three complete redshift surveys is investigated. The correlation length is shown to scale approximately as the square root of the distance limit in both the CfA and Southern Sky catalogs, but to be independent of the distance limit in the IRAS sample. This effect is found to be due to factors such as the large positive density fluctuations in the foreground of the optically selected catalogs biasing the correlation length estimate downward, and the brightest galaxies appearing to be more strongly clustered than the mean.
ACCESS-TC: Vortex Specification, 4DVAR Initialization, Verification, and Structure Diagnostics

AbstractThe Australian Community Climate and Earth System Simulator (ACCESS) has been adapted for operational and research applications on tropical cyclones. The base system runs at a resolution of 0.11° and 50 levels. The domain is relocatable and nested in coarser-resolution ACCESS forecasts. Initialization consists of five cycles of four-dimensional variational data assimilation (4DVAR) over 24 h. Forecasts to 72 h are made. Without vortex specification, initial conditions usually contain a weak and misplaced circulation pattern. Significant effort has been devoted to building physically based, synthetic inner-core structures, validated using historical dropsonde data and surface analyses from the Atlantic. Based on estimates of central pressure and storm size, vortex specification is used to filter the analyzed circulation from the original analysis, construct an inner core of the storm, locate it to the observed position, and merge it with the large-scale analysis at outer radii.Using all available c.
Thermoelectric properties of Ba8Ga16Ge30 with TiO2 nanoinclusions

The effects on thermal and electrical properties of adding small amounts of TiO2 nanoinclusions to bulk Ba8Ga16Ge30 clathrate have been investigated. The thermal properties were analysed using the transient plane source technique and the analysis showed a significant decrease in thermal conductivity as the volume fraction of TiO2 increased from 0 vol. % to 1.2 vol. %. The introduction of TiO2 nanoparticles caused a shift in the peak value of the Seebeck coefficient towards lower temperatures. The maximum value of the Seebeck coefficient was, however, only little affected. The introduction of TiO2 nanoparticles into the bulk Ba8Ga16Ge30 resulted in an increased electrical resistivity of the sample, thus simultaneously reducing the charge carrier contribution to the thermal conductivity, partly explaining the decrease in total thermal conductivity. Due to the large increase in resistivity of the samples, ZT was only somewhat improved for the material with 0.4 vol. % TiO2 while the ZT values of the other materials were lower than for the reference Ba8Ga16Ge30 material without TiO2 nanoparticles. The combined results are consistent with a scenario where the nanoparticle introduction causes a light doping of the semiconductor matrix and an increased concentration of phonon scattering centres.
On a class of linear constant systems which have a common quadratic Lyapunov function

The common Lyapunov function problem to be studied here, is to find a set of systems which have a common quadratic Lyapunov function guaranteeing asymptotic stability of its all member systems. This problem comes from diverse fields of system stability analysis. Several sets of linear systems which have a common quadratic Lyapunov function are known. But these results are still restrictive. In this paper, we provide one more new class of such systems. We first show a necessary and sufficient condition for a set of systems to have a common quadratic Lyapunov function. By using this condition and a property of M-matrices, we obtain a class of systems having a common quadratic Lyapunov function. A numerical example is presented to show that the obtained class is in fact a new one.
Applications of cavity optomechanics

“Cavity-optomechanics” aims to study the quantum properties of mechanical systems. A common strategy implemented in order to achieve this goal couples a high finesse photonic cavity to a high quality factor mechanical resonator. Then, using feedback forces such as radiation pressure, one can cool the mechanical mode of interest into the quantum ground state and create non-classical states of mechanical motion. On the path towards achieving these goals, many near-term applications of this field have emerged. After briefly introducing optomechanical systems and describing the current state-of-the-art experimental results, this article summarizes some of the more exciting practical applications such as ultra-sensitive, high bandwidth accelerometers and force sensors, low phase noise x-band integrated microwave oscillators and optical signal processing such as optical delay-lines, wavelength converters, and tunable optical filters. In this rapidly evolving field, new applications are emerging at a fast pace, but this article concentrates on the aforementioned lab-based applications as these are the most promising avenues for near-term real-world applications. New basic science applications are also becoming apparent such as the generation of squeezed light, testing gravitational theories and for providing a link between disparate quantum systems.
Intermediate-asymptotic structure of a dewetting rim with strong slip

When a thin viscous liquid film dewets, it typically forms a rim which spreads outwards, leaving behind a growing dry region. We consider the dewetting behavior of a film, when there is strong slip at a liquid-substrate interface. The film can be modeled by two coupled partial differential equations (PDEs) describing the film thickness and velocity. Using asymptotic methods, we describe the structure of the rim as it evolves in time and the rate of dewetting, in the limit of large slip lengths. An inner region emerges, closest to the dewetted region, where surface tension is important; in an outer region, three subregions develop. This asymptotic description is compared with numerical solutions of the full system of PDEs.
Korn inequalities for elastic junctions of massive bodies, thin plates, and rods

Korn inequalities have been obtained for junctions of massive elastic bodies, thin plates, and rods in many different combinations. These inequalities are asymptotically sharp thanks to the introduction of various weight factors in the -norms of the displacements and their derivatives. Since thin bodies display different reactions to stretching and bending, such Korn inequalities are necessarily anisotropic. Junctions of elastic bodies with contrasting stiffness are allowed, but the constants in the inequalities obtained are independent of both the relative thickness and the relative rigidity . The norms corresponding to rigidly clamped elements of a structure are essentially different from the norms corresponding to hard-movable or movable elements that are not fastened directly, but only by means of neighbouring elements; therefore, an adequate structure of the weighted anisotropic norms is determined by the geometry of the whole junction. Each variant of Korn inequality is supplied with an example confirming the optimal choice of the weight factors.
The DOE ARM Aerial Facility

The Department of Energy Atmospheric Radiation Measurement (ARM) program is a climate research user facility operating stationary ground sites that provide long-term measurements of climate-relevant properties, mobile ground- and ship-based facilities to conduct shorter field campaigns (6–12 months), and the ARM Aerial Facility (AAF). The airborne observations acquired by the AAF enhance the surface-based ARM measurements by providing high-resolution in situ measurements for process understanding, retrieval-algorithm development, and model evaluation that are not possible using surface-or satellite-based techniques. Several ARM aerial efforts were consolidated to form AAF in 2006. With the exception of a small aircraft used for routine measurements of aerosols and carbon cycle gases, AAF at the time had no dedicated aircraft and only a small number of instruments at its disposal. AAF successfully carried out several missions contracting with organizations and investigators who provided their research airc.
Empirical characterization of blue dwarf galaxies

We present an analysis of the optical and far-infrared properties of a homogeneous sample of blue dwarf galaxies. The luminosity of the galaxies is parametrized in terms of their metallicity, size, and velocity dispersion. The environment of the galaxies is also searched for companions, finding that a large fraction of the sampled galaxies are truly isolated. The kinematics of the ionized gas is also discussed, as well as the history of the star-formation rate
Extreme points of the unit ball of the space of Lipschitz functions

We consider the space of all Lipschitz functions on a metric space with bounded Lipschitz norm, and give an intrinsic characterization of the extreme points of the unit ball. We briefly discuss some examples of extreme Lipschitz functions, and apply the result to show that if the norm of a Banach space is Gateaux differentiable then extreme functions on any one-dimensional subspace may be canonically extended to extreme functions on the whole space.
Rings of differential operators on toric varieties

Let be a finite dimensional toric variety over an algebraically closed field of characteristic zero, k. Let be the sheaf of differential operators on . We show that the ring of global sections, is a finitely generated Noetherian k-algebra and that its generators can be explicitly found. We prove a similar result for the sheaf of differential operators with coefficients in a line bundle.
Books-Received - the Geology of Multi-Ring Impact Basins - the Moon and Other Planets

Preface 1. The multi-ring basin problem 2. From crater to basin 3. The 'archetype' basin: Orientale 4. An ancient basin: Nectaris 5. A modified basin: Crisium 6. A transitional basin: Serenitatis 7. The largest basin: Imbrium 8. Geological processes in the formation of lunar basins 9. Multi-ring basins on the terrestrial planets 10. Multi-ring basins and planetary evolution References.
Equilibrium crystal shape of the Potts model at the first-order transition point

We investigate the Q-state two-dimensional Potts model. The anisotropic interfacial tension is related by duality to the anisotropic correlation length. For Q > 4 we calculate exactly the anisotropic correlation length at the first-order transition point. From the calculated anisotropic correlation length, the equilibrium crystal shape (ECS) is derived via the Wulff construction. The ECS is expressed by means of a simple algebraic curve. Regarding Q as a temperature scale, we show that the Potts model has the same ECS as the eight-vertex model. We discuss a connection between the ECS and the q-deformed pseudo-Euclidian algebra.
Mathematical analysis of pre-exposure prophylaxis on HIV infection.

We develop a mathematical model which seeks to assess the impact of HIV Pre-Exposure Prophylaxis (PrEP) on the prevalence and incidence of HIV infection. Mathematical analysis of the model is carried out to establish the threshold conditions that determine the stability of the steady states. Numerical simulations are performed to gain insight into the use and efficacy of PrEP. Results from our model reveal that the basic reproduction number is a function of the rate at which individuals use PrEP and the rate at which PrEP protects individuals from HIV infection. Furthermore, strategies where either PrEP awareness or PrEP efficacy was low show potential loop-holes that can lead to more complications than benefits. The best strategies revealed by our results is that a high level of awareness and high PrEP efficacy are needed.
Use of genetic algorithms in ISAR imaging of targets with higher order motions

Genetic algorithms (GA) are proposed for inverse synthetic aperture radar (ISAR) imaging. GA is used for motion parameters search in place of exhaustive search in the adaptive joint time-frequency (AJTF) algorithm. While maintaining the same accuracy, GA has lower computational complexity, especially for targets with higher order motions.
Measures of Agreement and Concordance With Clinical Research Applications

This article reviews measures of interrater agreement, including the complementary roles of tests for interrater bias and estimates of kappa statistics and intraclass correlation coefficients (ICCs), following the developments outlined by Landis and Koch (1977a; 1977b; 1977c). Category-specific measures of reliability, together with pairwise measures of disagreement among categories, are extended to accommodate multistage research designs involving unbalanced data. The covariance structure of these category-specific agreement and pairwise disagreement coefficients is summarized for use in modeling and hypothesis testing. These agreement/disagreement measures of intraclass/interclass correlation are then estimated within specialized software and illustrated for several clinical research applications. Further consideration is also given to measures of agreement for continuous data, namely the concordance correlation coefficient (CCC) developed originally by Lin (1989). An extension to this CCC was published by King and Chinchilli (2001b), yielding a generalized concordance correlation coefficient which is appropriate for both continuous and categorical data. This coefficient is reviewed and its use illustrated with clinical research data. Additional extensions to this CCC methodology for longitudinal studies are also summarized.
The Myth of Global Fit Indices and Alternatives for Assessing Latent Variable Relations

A common myth among organizational researchers who use structural equations is that adequate fit values from the composite (overall) model speak directly to the adequacy of the proposed theory. However, this is a fallacious assumption, as significant misspecification among the theoretical paths between constructs can occur and be missed when there is an overreliance on global fit indices. To debunk this myth and provide a more valid alternative, the authors begin with an overview of latent variable model estimation procedures, emphasizing how they affect values obtained with fit measures for composite models. The authors next demonstrate problems with these measures, using an algebraic analysis of two popular composite fit indices (CFI, RMSEA) and results from simulation analysis with these indices. They then highlight two alternative indices that focus more on path model relations (NSCI-P, RMSEA-P) and that outperform the composite fit indices in the detection of model misspecification among the latent variables. The authors conclude with recommendations how these latter indices can be incorporated into model evaluation and theory testing.
Compensation of mechanical inaccuracies in micro-CT and nano-CT

Micro-CT and especially nano-CT scanning requires very high mechanical precision and stability of object manipulator, which is difficult to reach. Several other problems, such as drift of emission point inside an X-ray source, thermal expansion in different parts of the scanner, mechanical vibrations, and object movement or shrinkage during long scans, can also contribute to geometrical inaccuracies. All these inaccuracies result in artifacts which reduce achievable spatial resolution. Linear distortions can be partially compensated by rigid X/Y shifts in projection images. More complicated object movement and shrinkage will require non-linear transforms. This paper investigates techniques to compensate geometrical inaccuracies by linear transformation only. We have developed two methods to estimate individual X/Y shifts in each measured projection. The first method aligns measured projections with forward-projected projections iteratively to reach an optimal X/Y shift estimation. It is more suitable for mechanical inaccuracies caused by random and jittery movement. The second method uses a very short reference scan acquired immediately after a main scan to obtain estimates of X/Y shifts. This method is rather effective for mechanical inaccuracies caused by slow and coherent mechanical drifts. Both methods have been implemented and evaluated on multiple scanners. Significant improvements in image quality have been observed.
On the lattice of congruences on a regular semigroup

A result of Reilly and Scheiblich for inverse semigroups is proved true also for regular semigroups. For any regular semigroup S the relation θ is defined on the lattice, Λ(S), of congruences on S by: (ρ, τ) ∈ θ if ρ and τ induce the same partition of the idempotents of S. Then θ is a congruence on Λ(S), Λ(S)/θ is complete and the natural homomorphism of Λ(S) onto Λ(S)/θ is a complete lattice homomorphism.
An item response model for Likert-type data that incorporates response time in personality measurements

This study defines a measurement index for the differences in response probabilities to an item. Based on the difference index, a probability–difficulty (PD) hypothesis is proposed. A general framework for modelling responses and response times (RTs) on Likert-type personality items is presented, in which the submodel describing the item responses can be a graded item response theory model, and the submodel describing RTs is developed based on the PD hypothesis. This framework is exemplified by employing the generalized partial credit model for responses and a log-normal model for RTs. Furthermore, Bayesian methods for estimating model parameters and for assessing the model–data fit are described. A simulation study shows that the new approach improves the accuracy of estimating the individual trait levels with the ancillary information contained in RTs. Finally, the applicability of our approach is illustrated by an empirical example in personality measurements.
Unsteady hydromagnetic free convection flow with hall current mass transfer and variable suction through a porous medium near an infinite vertical porous plate with constant heat flux

The effects of Hall current on unsteady free convection flow of an MHD viscous incompressible fluid along an infinite vertical porous plate are investigated in the presence of a uniformly applied magnetic field acting in a plane which makes an angle α with the plane transverse to the plate. A similarity parameter, taken to be a function of time, is introduced, and the suction velocity is considered to be inversely proportional to this parameter. Similarity equations are then derived and solved numerically. The effects of the Hall parameter, the magnetic parameter and the permeability are discussed and shown graphically.
Dirichlet process mixture models for unsupervised clustering of symptoms in Parkinson's disease

In this paper, the goal of identifying disease subgroups based on differences in observed symptom profile is considered. Commonly referred to as phenotype identification, solutions to this task often involve the application of unsupervised clustering techniques. In this paper, we investigate the application of a Dirichlet process mixture model for this task. This model is defined by the placement of the Dirichlet process on the unknown components of a mixture model, allowing for the expression of uncertainty about the partitioning of observed data into homogeneous subgroups. To exemplify this approach, an application to phenotype identification in Parkinson's disease is considered, with symptom profiles collected using the Unified Parkinson's Disease Rating Scale.