Miracle-dz/UniFAR-FTUs huggingface dataset:
ON THE STABILITY OF A HETEROSCEDASTIC PROCESS

In this paper we derive the stability conditions in a time series regression model with a particular form of conditional heteroscedasticity. The variables affecting the variance include lagged errors, lagged dependent variables and a forecast variable. In addition to the usual stability conditions in a dynamic model, a condition on the parameters of the heteroscedasticity equation is also required.
Novel p-type oxides with corundum structure for gallium oxide electronics

P-type ultra-wide bandgap materials have been desired for gallium oxide electronics. We show that the self-trapped exciton (STE) in α-Ga2O3 is a stable state relative to the free exciton from analysis of Urbach tails in absorption spectra. The stable STE formation indicates strong localization of holes, which suggests that α-Ga2O3 is disadvantageous as a p-type semiconductor. Instead of doping methods, using p-type material that have the same crystal structure as Ga2O3 is effective. An alloy thin film of α-(Rh,Ga)2O3 showed clear p-type conductivity with the large positive Hall coefficient. The α-Ir2O3 thin films also showed p-type conductivities. The origin of p-type conductivity is attributed to that 5d orbitals of Ir which consists the top of the valence band of α-Ir2O3, being located at the upper energy level compared to 2p orbitals of oxygen atoms.
Images of chemical structures as molecular representations for deep learning

Implementing Artificial Intelligence for chemical applications provides a wealth of opportunity for materials discovery, healthcare and smart manufacturing. For such applications to be successful, it is necessary to translate the properties of molecules into a digital format so they can be passed to the algorithms used for smart modelling. The literature has shown a wealth of different strategies for this task, yet there remains a host of limitations. To overcome these challenges, we present two-dimensional images of chemical structures as molecular representations. This methodology was evaluated against other techniques in both classification and regression tasks. Images unlocked (1) superior augmentation strategies, (2) application of specialist network architectures and (3) transfer learning, all contributing to superior performance and without prior specialised knowledge on cheminformatics required. This work takes advantage of image feature maps which do not rely on chemical properties and so can represent multi-component systems without further property calculations.
Response of polar cap convection to the interplanetary magnetic field

Because the relationship between convection and the interplanetary magnetic fleld is of crucial importance to the understanding of the large-scale interaction between the solar wind and the geomagnetic field, 227 hours of polar- cap balloon electricfield measurements were examined in search of such a relationship, with the conclusion that magnetic field reconnection dominates viscous interaction or any other mechanism for transferring energy to the magnetosphere. (WDM)
The Structure and Evolution of the Lagoon Nebula. I. Submillimeter Continuum and CO Line Mapping

We present submillimeter- and millimeter-wave maps tracing the molecular gas and dust around the edge of the H II region M8. The molecular material is clumped into cores on the scale of the beam (about 0.1 pc) whose temperatures can be estimated from CO observations. The masses of the clumps, estimated from their continuum fluxes, are consistent with a power-law mass function with index -1.7 ± 0.6, which agrees with determinations for other molecular clouds at similar resolutions, using molecular lines as tracers. The submillimeter clumps are sited at the interface between the H II region and the background molecular cloud, where they are exposed to the ultraviolet flux of OB stars. The physical parameters of the clumps are compared to published models of molecular clouds undergoing photoevaporation, suggesting that the pressure of the ionized gas exceeds the internal pressure of the clumps and, therefore, that a shock front will be driven into the clumps. The clumps themselves currently appear to be gravitationally unbound, but the compression may be sufficient to induce collapse.
Stability of linear shear flows in shallow water

The stability or instability of various linear shear flows in shallow water is considered. The linearized equations for waves on the surface of each flow are solved exactly in terms of known special functions. For unbounded shear flows, the exact reflection and transmission coefficients R and T for waves incident on the flow, are found. They are shown to satisfy the relation |R|2= 1+ |T|2, which proves that over reflection occurs at all wavenumbers. For flow bounded by a rigid wall, R is found. The poles of R yield the eigenvalue equation from which the unstable mides can be found. For flow in a channel, with two rigid walls, the eigenvalue equation for the modes is obtained. The results are compared with previous numerical results.
Hellas as a Possible Site of Ancient Ice-Covered Lakes on Mars

Abstract Based on topographic, morphologic, and stratigraphic evidence, we propose that ancient water-laid sediment is the dominant component of deposits within Hellas Planitia, Mars. Multiple-layered sediment is manifested by alternating benches and scarps visible in Mars orbiting camera narrow-angle (MOC NA) images. Viking Orbiter camera and MOC NA images were used to map contacts and stratigraphically order the different materials units within Hellas. Mars orbiting laser altimeter (MOLA) data reveal that the contacts of these sedimentary units, as well as a number of scarps or other abrupt changes in landscape texture, trace contours of constant elevation for thousands of km, and in one case all around the basin. Channels, consensually interpreted to be cut by water, lead into the basin. MOLA results indicate that the area encompassed by greater Hellas' highest closed contour is nearly one-fifth that of the entire northern plains, making the Hellas “drainage” area much larger than previously reported. If lakes formed under climatic conditions similar to the modern Martian climate, they would develop thick ice carapaces, then the lakes would eventually sublimate away. Two units within Hellas exhibit a reticulate or honeycomb pattern, which we speculate are impressions made by lake-lowered ice blocks grounding into initially soft mud.
U NVEILING INFLUENCE OF HOME MACROECONOMIC FACTORS ON INDIAN OUTBOUND M&A

Indian enterprises have succeeded in climbing the ladder of outward M&A transactions and out-performing everyone’s expectations post 1990s. This paper aims to recalibrate the empirical literature of India’s outbound M&A by considering the impact of home country macroeconomics variables from 1990 to 2019. Bivariate regression and quantile regression approach is used to examine the impact of selected macroeconomic factors on outward M&A deal volume. The study found that the selected macroeconomic variables gross domestic product, population, exports, imports, interest rates, international reserves, human capital, trade openness, patents, exchange rate and per capita GDP influences the deal volume especially at high percentiles. The home country companies prefer to invest overseas specially when macroeconomic indicators change at high level. The empirical analysis of this paper provides policy makers a better understanding of determinants of outbound M&A transactions by Indian firms, to formulate push policies to encourage the same.
The role of overeducation and horizontal mismatch for gender inequalities in labor income of higher education graduates in Europe

Evidence on gender inequality in the labor market is extensive. However, little is known about the potential role of overeducation and horizontal mismatch in explaining women’s labor-market disadvantages. We draw on recent data from the Eurograduate pilot survey to investigate the role of overeducation, field-of-study mismatch and field-specific overskilling for gender gaps in labor income in the European landscape. We found considerable variations in the extent of both gender earning gaps (GEGs) and wage gaps (GWGs) across countries. However, our decomposition analyses show that neither overeducation nor horizontal mismatch contribute to explaining these gender gaps. The lack of mediation seems related to either the absence of gender differences in overeducation and horizontal mismatch, or to the nonexistence of income penalties associated with the mismatch.
Quanta of the magnetic monopole entering the Oersted–Ampere law

The paper demonstrates that quantization of the magnetic monopole, much similar to that concerning the magnetic flux in superconductors, can occur also in a non–superconducting case represented by the Oersted–Ampere law. This result can occur on condition the Joule–Lenz law for the action quanta of electrons participating in the effect is taken into account. The quantum result obtained for a monopole can be confirmed with the aid of the uncertainty principle applied to the energy and time period characteristic for the current involved in the Oersted–Ampere phenomenon.
Customized gaming system engages young children in reaching and balance training

Purpose Trunk stability, an important prerequisite for many activities of daily living, can be impaired in children with movement disorders. Current treatment options can be costly and fail to fully engage young participants. We developed an affordable, smart screen-based intervention and tested if it engages young children in physical therapy goal driven exercises. Methods Here we describe the ADAPT system, Aiding Distanced and Accessible Physical Therapy, which is a large touch-interactive device with customizable games. One such game, “Bubble Popper,” encourages high repetitions of weight shifts, reaching, and balance training as the participant pops bubbles in sitting, kneeling, or standing positions. Results Sixteen participants aged 2–18 years were tested during physical therapy sessions. The number of screen touches and length of game play indicate high participant engagement. In trials lasting less than 3 min, on average, older participants (12–18 years) made 159 screen touches per trial while the younger participants (2–7 years) made 97. In a 30-min session, on average, older participants actively played the game for 12.49 min while younger participants played for 11.22 min. Conclusion The ADAPT system is a feasible means to engage young participants in reaching and balance training during physical therapy.
The local isotropy hypothesis and the turbulent kinetic energy dissipation rate in the atmospheric surface layer

We test the applicability of the local isotropy hypothesis to surface‐layer turbulent flow; turbulent velocities measured with a three‐dimensional sonic anemometer are used for this purpose, and the predictions of local isotropy for the spectra, second‐ and third‐order structure functions are assessed against measured data. Also investigated are scale interactions via the correlation between velocities and velocity increments, and the ability of isotropic spectral models to reproduce measured spectra. In general, second‐order structure functions display a narrower inertial range than the corresponding spectra; both the known effects of path‐averaging and the predictions of the spectral models show that the sonic anemometer is unable to resolve the whole inertial range, even at a measurement frequency of 60 Hz. We confirm previous results that unstable runs tend to be more isotropic, but find that, for third‐order statistics, isotropy does not hold well for the data analysed. Turbulence intensity, and not atmospheric stability, plays a determining role on the correlation coefficient between velocities and velocity increments. The observed anisotropic behaviour has important implications for the calculation of the turbulent kinetic energy dissipation rate from Kolmogorov's four‐fifths law, whose estimates are consistently smaller than those from the inertial range of the spectrum or the structure functions. Copyright © 2004 Royal Meteorological Society
Dielectric rod leaky-wave antennas for millimeter-wave applications

Dielectric rod leaky-wave antennas have the property of being frequency scannable. Bounds are derived for the proper range of spacing of perturbations along the rod to avoid an intrusion upon a grating lobe when frequency scanning. In addition some experimental results are reported on sidelobe levels and polarizations in the far field for these antennas made from a material with \epsilon_{r}= 2.33 at 81.5 GHz.
Strain and size effects on heat transport in nanostructures

The relative role of the residual strain and dimensional scaling on heat transport in nanostructures is investigated by molecular dynamics simulations of a model Lennard-Jones solid. It is observed that tensile (compressive) strains lead to a reduction (enhancement) of the lattice thermal conductivity. A nonhydrostatic strain induces thermal conductivity anisotropy in the material. This effect is due to the variation with strain of the stiffness tensor and lattice anharmonicity, and therefore of the phonon group velocity and phonon mean free path. The effect due to the lattice anharmonicity variation appears to be dominant. The size effect was studied separately in unstrained thin films. Phonon scattering on surfaces leads to a drastic reduction of the thermal conductivity effect which is much more important than that due to strain in the bulk. It is suggested that strain may be used to tailor the phonon mean free path which offers an indirect method to control the size effect.
Articulated Hands

Kinematic and control issues are discussed in the context of an articulated, multifinger mechanical hand. Hand designs with particular mobility properties are illustrated, and a definition of accuracy points within manipulator workspace is given. Optimization of tlte physical dimensions of the Stanford-JPL hand is described. Several architectures for position and force control of this multiloop mechanism are described, including a way of dealing with the internal forces inherent in such systems. Preliminary results are shown for the joint torque subsystem used in the hand controller.
Analysis of enclosed sound fields using spherical microphone array processing

Enclosed sound fields in rooms and auditoria are characterized by multiple reflections in addition to the direct sound. The spatial and temporal manner in which sound propagates from the sound source to a listener determines the acoustics of the enclosed space. Recent studies showed that spherical microphone arrays and associated array processing can be used effectively in the experimental study of the acoustics of auditoria. The main advantages presented are the true three‐dimensional analysis and the effectiveness of array processing in the spherical harmonics domain. Spherical microphone array design issues will first be reviewed in this work, in particular concerning the design of open‐sphere arrays useful in room acoustics analysis with high spatial resolution. Then, beam‐forming methods will be presented which can facilitate identification of individual room reflections, and computation of directional room impulse responses. Finally, the use of optimal array processing methods will be presented whic.
Modern View on the Role of Sex-Specific Levels of High-Sensitive Cardiospecific Troponins T and I in the Diagnosis of Myocardial Infarction

It is well known that the molecules of cardiospecific troponins T and I are localized in the troponin-tropomyosin complex of the cytoplasm of cardiac myocytes and, due to the specific localization, these cardiospecific troponins are widely used as diagnostic biomarkers of myocardial infarction. Cardiospecific troponins are released from the cytoplasm of cardiac myocytes as a result of irreversible cell damage (for example, ischemic necrosis of cardiomyocytes in myocardial infarction or apoptosis of cardiac myocytes in cardiomyopathies and heart failure) or reversible damage (for example, intense physical exertion, hypertension, the influence of stress factors, etc.). Current immunochemical methods for determining cardiospecific troponins T and I have extremely high sensitivity to subclinical (minor) damage to myocardial cells and, thanks to modern high-sensitive methods, it is possible to detect damage to cardiac myocytes in the early (subclinical) stages of a number of cardiovascular pathologies, including myocardial infarction. So, recently, leading cardiological communities (the European Society of Cardiology, the American Heart Association, the American College of Cardiology, etc.) have approved algorithms for early diagnosis of myocardial infarction based on the assessment of serum levels of cardiospecific troponins in the first 1 - 3 h after the onset of pain syndrome. An important factor that may affect early diagnostic algorithms of myocardial infarction are sex-specific features of serum levels of cardiospecific troponins T and I. This manuscript presents a modern view on the role of sex-specific serum levels of cardiospecific troponins T and I in the diagnosis of myocardial infarction and the mechanisms of formation of sex-specific serum levels of troponins.
Big Data Analytics and Auditing: A Review and Synthesis of Literature

The use of data analytics in auditing is increasingly growing. The application of common data analytics to audit engagements appears to be lagging behind other areas of practice, even though data analytics is thought to represent the future of audit, and there are still few publications that have examined this influence. This article reviews data analytics in audits and its potential for future audit engagements to describe the evolution of this research trend and picture its future growth directions. Future audit research potential and difficulties are also discussed. Data analytics application in auditing has enormous potential for refining audit quality, decreasing errors, increasing process transparency, and enhancing stakeholders’ confidence. We conducted a systematic literature review using the PRISMA approach. A total of 100 articles published in English from January 2011 to November 2021 were identified through a systematic search of reputed databases, including Web of Science and Scopus and many others. Our analysis reveals that data analytics is a promising domain for the auditing practice as it improves audit efficiency and promotes audit work digital transformation. While reviewing the most pertinent literature in the context of data analytics in auditing, this study offers insights on potential new directions and waning views on big data analytics in auditing. Doi: 10.28991/ESJ-2023-07-02-023 Full Text: PDF
Surface-enhanced spectroscopy

In 1978 it was discovered, largely through the work of Fleischmann, Van Duyne, Creighton, and their coworkers that molecules adsorbed on specially prepared silver surfaces produce a Raman spectrum that is at times a millionfold more intense than expected. This effect was dubbed surface-enhanced Raman scattering (SERS). Since then the effect has been demonstrated with many molecules and with a number of metals, including Cu, Ag, Au, Li, Na, K, In, Pt, and Rh. In addition, related phenomena such as surface-enhanced second-harmonic generation, four-wave mixing, absorption, and fluorescence have been observed. Although not all fine points of the enhancement mechanism have been clarified, the majority view is that the largest contributor to the intensity amplification results from the electric field enhancement that occurs in the vicinity of small, interacting metal particles that are illuminated with light resonant or near resonant with the localized surface-plasmon frequency of the metal structure. Small in this context is gauged in relation to the wavelength of light. The special preparations required to produce the effect, which include among other techniques electrochemical oxidation-reduction cycling, deposition of metal on very cold substrates, and the generation of metal-island films and colloids, is now understood to be necessary as a means of producing surfaces with appropriate electromagnetic resonances that may couple to electromagnetic fields either by generating rough films (as in the case of the former two examples) or by placing small metal particles in close proximity to one another (as in the case of the latter two). For molecules chemisorbed on SERS-active surface there exists a "chemical enhancement" in addition to the electromagnetic effect. Although difficult to measure accurately, the magnitude of this effect rarely exceeds a factor of 10 and is best thought to arise from the modification of the Raman polarizability tensor of the adsorbate resulting from the formation of a complex between the adsorbate and the metal. Rather than an enhancement mechanism, the chemical effect is more logically to be regarded as a change in the nature and identity of the adsorbate.
A novel erbium/ytterbium co-doped distributed feedback fiber laser with single-polarization and unidirectional output

An asymmetrical π-phase-shift distributed feedback (DFB) fiber laser written in erbium/ytterbium co-doped fiber is fabricated. A new self-injection locking method is employed to make the proposed DFB fiber laser operate in single polarization states, which is composed of a polarization-dependent isolator and an optical circulator. The output character is investigated. 9.5 mW of the backward output power is obtained at the 159 mW pump power. The output power in one side is much higher than that in the other side, indicating that the DFB fiber laser operates in the unidirectional output. The delayed self-homodyne measurement is employed to detect the radio frequency spectrum of the DFB fiber laser. This novel single polarization DFB fiber laser has the potential application in the fiber optical sensor and optical communications.
The Hamiltonian Boundary Term

iopas120323 2 / 36 ● The Hamiltonian for interacting classical fields with quite general theories of dynamic geometry generates the evolution of a spatial region along a time-like vector field. ● It includes a boundary term which determines the value of the Hamiltonian. From this value one obtains the quasi-local quantities: energy-momentum, angular-momentum/center-of-mass. ● The Hamiltonian boundary term also directly controls the boundary term in the variation of the Hamiltonian. From the latter one obtains the associated built in boundary conditions and an expression for energy flux. ● Here we extend our preferred boundary term choice for Einstein’s GR (which we had identified in 2005) to select a unique boundary term expression for any dynamic geometry gravity theory along with interacting classical fields.
Constitutive equations in suspension mechanics. Part 2. Approximate forms for a suspension of rigid particles affected by Brownian rotations

Approximate constitutive equations are derived for a dilute suspension of rigid spheroidal particles with Brownian rotations, and the behaviour of the approximations is explored in various flows. Following the suggestion made in the general formulation in part 1, the approximations take the form of Hand's (1962) fluid model, in which the anisotropic microstructure is described by a single second-order tensor. Limiting forms of the exact constitutive equations are derived for weak flows and for a class of strong flows. In both limits the microstructure is shown to be entirely described by a second-order tensor. The proposed approximations are simple interpolations between the limiting forms of the exact equations. Predictions from the exact and approximate constitutive equations are compared for a variety of flows, including some which are not in the class of strong flows analysed.