Miracle-dz/UniFAR-FTUs huggingface dataset:
Casual Models Do Not Support Scientific Conclusions: A Comment in Support of Freedman

Overview A critical distinction in methodological work is between (a) building (and applying) statistical models for the processes that generate the social science data and (b) tossing the data at available statistical methods. In my own work I strive for (a) and discourage others from settling for (b). Regrettably, expositions and applications of the popular causal modeling methods (under the various names path analysis, structural equation models, LISREL, etc.) contain much of (b) and little of (a). In fact, my favorite typographical error "casual models" (which I've suffered in print) is enjoyable in large part because of its accidental accuracy. And an argument can be made that the methodological proselytizing for and dominance of causal models has retarded the much more useful methodological work of (a). A similar theme is present throughout Freedman's paper, as in the last paragraph of his conclusion which begins "My opinion is that investigators need to think more about the underlying social processes. ". Earlier in the paper Freedman requires that the "as-if-by-experiment" conclusions "must depend on a theory of how the data came to be generated. " The translation of substantive theory into methods for data collection and analysis is where I think the fertile interaction between statisticians and social scientists lies (rather than in arguing a "thumbs up" or "thumbs down" on path analysis).
Zn(O,S) buffer layers by atomic layer deposition in Cu(In,Ga)Se2 based thin film solar cells: Band alignment and sulfur gradient

Thin film solar cells with the structure sodalimeglass∕Mo∕Cu(In,Ga)Se2∕Zn(O,S)∕ZnO∕ZnO:Al are studied for varying thickness and sulfur content of the Zn(O,S) buffer layer. These Zn(O,S) layers were deposited by atomic layer deposition (ALD) at 120°C. Devices with no or small concentrations of sulfur in the buffer layer show low open-circuit voltages. This is explained by the cliff, or negative conduction-band offset (CBO), of −0.2eV measured by photoelectron spectroscopy (PES) and optical methods for the Cu(In,Ga)Se2 (CIGS)∕ZnO interface. Devices with ZnS buffer layers exhibit very low photocurrent. This is expected from the large positive CBO (spike) of 1.2eV measured for the CIGS∕ZnS interface. For devices with Zn(O,S) buffer layers, two different deposition recipes were found to yield devices with efficiencies equal to or above reference devices in which standard CdS buffer layers were used; ultrathin Zn(O,S) layers with S∕Zn ratios of 0.8–0.9, and Zn(O,S) layers of around 30nm with average S∕Zn ratios.
EAS‐elements for two‐dimensional, three‐dimensional, plate and shell structures and their equivalence to HR‐elements

The enhanced assumed strain (EAS) method, recently proposed by Simo and Rifai13, is used to develop new four-node membrane, plate and shell elements and eight-node solid elements. The equivalence of certain EAS-elements with Hellinger-Reissner (HR) elements is discussed. For instance, the seven-parameter element EAS-7 with 2 × 2 integration is identical to the HR-element of Pian and Sumihara2. Eight-node solid elements which are free of volumetric locking and four-node shell elements which have an improved membrane and bending behaviour, compared to the Bathe-Dvorkin shell element7, are introduced. Numerical tests for linear elastic problems show an improved performance of the EAS-elements.
Ice nucleation in orographic wave clouds: Measurements made during INTACC

This paper reports on measurements made during the INTACC (INTeraction of Aerosol and Cold Clouds) experiment. Observations are shown from six wave cloud flights in the temperature range −12°C to −40 °C. In nearly all cases ice nucleation does not occur until after droplets have formed. Parcel trajectories that experience temperatures below −35°C are dominated by homogeneous nucleation, while parcel trajectories that stay above −35°C are affected by heterogeneous nucleation. Ice particles appear to be nucleated after the parent droplets reach their largest size and coldest temperature at the wave peak. The most likely heterogeneous nucleation mechanisms are immersion and/or contact nucleation.
STRUCTURAL PARAMETER IDENTIFICATION USING DAMPED TRANSFER MATRIX AND STATE VECTORS

A new method for identification of structural parameters is proposed using Damped Transfer Matrices (DTM) and state vectors. A new transfer matrix is derived for continuous mass systems including the damping parameters. The state vector at a location is the sum of the internal and external contributions of displacements, forces, and moments at that point, when it is multiplied with the transfer matrix, state vector at the adjacent location is obtained. The structural identification algorithm proposed here involves prediction of displacement responses at selected locations of the structure using DTM and compares them with the measured responses at the respective locations. The mean square deviations between the measured and predicted responses at all locations are minimized using a nonclassical optimization algorithm, and the optimization variables are the unknown stiffness and damping parameters in the DTM. A nonclassical heuristic Particle Swarm Optimization algorithm (PSO) is used, since it is especially suited for global search. This DTM algorithm with successive identification strategy is applied on one element or sub-structure of a structure at a time and identifies all the parameters of adjacent elements successively. The algorithm is applied on numerically simulated experiments of two structures such as ten degrees of freedom lumped mass system and a cantilever with seven finite elements and one sub-structure of a nine member frame structure. Also this algorithm is verified experimentally on a sub-structure of a fixed beam. The main advantage of this algorithm is that it can be used for the local identification in a zone in a structure without modeling the entire global structure.
Correlation function ratios and the identification of space plasma instabilities

Wave-particle transport in a collisionless plasma is due to particle scattering by enhanced fluctuations associated with the growth of instabilities. In particular, relatively short wavelength kinetic instabilities are frequently invoked to explain many different types of plasma transport in space. Although there is an extensive theoretical and simulation literature describing the potential applications of many such instabilities, there are only a few cases of clear-cut identification of kinetic modes in space. The research described in this paper uses linear Vlasov dispersion theory to study correlation functions and dimensionless correlation function ratios for fluctuations or instabilities in three space plasma regimes. This research shows that both the compressibility and the parallel compressibility are likely to be useful in distinguishing modes in the magnetosheath as well as in the plasma sheet boundary layer and that helicity remains a useful identifier of electromagnetic ion/ion instabilities in the foreshock.
Structural Equation Models

Structural equation models (SEMs) have been discussed extensively in the psychometrics and quantitative behavioral sciences literature. However, many statisticians and researchers in other areas of application are relatively unfamiliar with their implementation. Here we review some of the SEM literature and describe basic methods, using examples from environmental epidemiology. We make connections to recent work on latent variable models for multivariate outcomes and to measurement error methods, and discuss advantages and disadvantages of SEMs compared with traditional regressions. We give a detailed example in which two models fit the same data well, yet one is physiologically implausible. This underscores the critical role of subject matter knowledge in the successful implementation of SEMs. A brief discussion on open research areas is included.
Zonal Jets in Wide Baroclinically Unstable Regions: Persistence and Scale Selection

Abstract Extremely persistent, equivalent barotropic zonal jets are observed in statistically steady quasigeostrophic two-layer beta-plane turbulence. Flows are forced by an imposed unstable vertical shear, horizontally uniform over domains several tens of Rossby radii wide. Damping is by surface drag, small-scale mixing, and for some runs, radiative relaxation. When dissipation is weak, zonal jets emerge with a meridional scale related to beta and the equilibrated eddy energy level as suggested by Rhines. Spinup behavior suggests a priori prediction of this level will be difficult. The scale of energy conversion also cannot be determined a priori, and while upscale energy transfer is important, (reverse) energy cascading ranges of any significant extent do not occur. Time scales considerably longer than those simply related to model parameters are prominent. The choices of doubly periodic boundary conditions and spatially homogeneous forcing and dissipation emphasize that the low-frequency behavior is du.
Classifying Spaces and Boundaries for Relatively Hyperbolic Groups

We prove the following: if a group Γ is torsion‐free, and relatively hyperbolic (with the Bounded Coset Penetration property), relative to a subgroup admitting a finite classifying space, then Γ admits a finite classifying space. In this case, if the subgroup admits a boundary in the sense of Z‐structures, we prove that Γ admits a boundary. This extends classical results of Rips, and of Bestvina and Mess to the relative case. 2000 Mathematics Subject Classification 20F67, 20F69.
EFFECTS OF SPATIAL VARIATIONS IN CORONAL ELECTRON AND ION TEMPERATURES ON TYPE III BURSTS. II. VARIATIONS IN ION TEMPERATURE

Quasilinear-based simulations are presented for the effects on coronal type III bursts of spatially varying ion temperature Ti in the corona. The simulations use a newly developed method for integrating spatial variations of coronal temperatures into our previous simulations for constant temperatures. The effects are simulated for monotonic Ti variations and/or for spatially localized enhancements in Ti. Generally, a localized enhancement in Ti has stronger effects on type III bursts than a corresponding monotonic variation in Ti. A localized Ti enhancement causes modulations to the dynamic spectra of fp and 2fp emission at frequencies corresponding to the disturbance: a narrowband slowly drifting intensification for both fp and 2fp emission and a narrowband suppression for 2fp emission. The fp emission may become observable due to the disturbance, although still much weaker than the 2fp emission. Signatures of the Ti enhancement are found in the 2fp spectral characteristics, e.g., the maximum flux and frequency drift rate. Importantly, these signatures are distinct from those of localized disturbances in electron temperature Te. The results indicate that coronal type III bursts provide a new tool to probe and distinguish localized disturbances in Ti or Te in the corona. Additionally, the presence of multiple spatially confined Ti enhancements at different heights may produce some observed fine structures in type III bursts; e.g., stria bursts and associated flux modulations in type IIIb bursts, and flux modulations in type IIIs whose beams traverse coronal shocks.
Dissipation in barred galaxies: the growth of bulges and central mass concentrations

Basic dynamical mechanisms that produce an amplification of the accretion rate of gas clouds into the central regions of barred galaxies, and their subsequent effects on the evolution of barred galaxies, are discussed. Weakly dissipative orbits, representing gas clouds, are computed in a barred galaxy model with a central mass concentration such as a black hole, or a secondary small inner bar. Amplified accretion across resonances that is especially rapid inside the inner Lindblad resonance, large excursions outside the galactic plane, and the existence of nontrivial attractors like strange (chaotic) attractors or limit cycles are found. The underlying physical mechanisms are, in general, due to the presence of broad horizontal and vertical resonances through which weakly dissipative particles can rapidly traverse. The principal physical implications of these findings are discussed. 65 refs.
Low-frequency sound scattering by internal waves in the ocean

In this paper, long-range propagation of low-frequency sound through an ocean waveguide with random inhomogeneities in the sound speed is studied. Closed equations for the mean field and correlation function of the sound field are derived using the Chernov method. These equations can be considered as a generalization of equations derived by Dozier and Tappert [J. Acoust. Soc. Am. 63, 353–365 (1978)], which accounts for 3D effects and cross-modal correlations. The equations derived in this paper in a general form are similar to the equations obtained by many other authors. However, without simplifications these equations are difficult to solve even numerically due to high dimension of the matrices appearing in the equations. Some simplifications of the equations for the mean field and correlation function are suggested that account for narrowness of the angular spectrum of the scattered acoustic field and which make these equations amenable for numerical implementation. To study solutions of the simplified.
Prequantum classical statistical field theory: background field as a source of everything?

Prequantum classical statistical field theory (PCSFT) is a new attempt to consider quantum mechanics (QM) as an emergent phenomenon, cf. with De Broglie's "double solution" approach, Bohmian mechanics, stochastic electrodynamics (SED), Nelson's stochastic QM and its generalization by Davidson, 't Hooft's models and their development by Elze. PCSFT is a comeback to a purely wave viewpoint on QM, cf. with early Schrodinger. There is no quantum particles at all, only waves. In particular, photons are simply wave-pulses of the classical electromagnetic field, cf. SED. Moreover, even massive particles are special "prequantum fields": the electron field, the neutron field, and so on. PCSFT claims that (sooner or later) people will be able to measure components of these fields: components of the "photonic field" (the classical electromagnetic field of low intensity), electronic field, neutronic field, and so on. At the moment we are able to produce quantum correlations as correlations of classical Gaussian random fields. In this paper we are interested in mathematical and physical reasons of usage of Gaussian fields. We consider prequantum signals (corresponding to quantum systems) as composed of a huge number of wave-pulses (on very fine prequantum time scale). We speculate that the prequantum background field (the field of "vacuum fluctuations") might play the role of a source of such pulses, i.e., the source of everything.
Natural Convection between Concentric Vertical Cylinders

The motion of a fluid in the closed annular cavity formed by two concentric vertical cylinders and two horizontal planes has been analyzed by a numerical solution of the equations of motion and energy using a high‐speed digital computer. The motion is generated by a radial density gradient caused by the thermal boundary conditions which are, typically: inner cylinder at a (dimensionless) temperature of unity; outer cylinder at a temperature of zero; horizontal boundaries adiabatic. The fluid is assumed to have constant thermodynamic and transport properties except for the density, which is temperature‐dependent in the buoyancy term of the equation of vertical motion (the Boussinesq approximation); the flow is assumed to be axisymmetric. The equations of time‐dependent motion have been solved, so that both transient and steady‐state solutions are obtained. The parameters of the problem, and the respective ranges of values which have been considered, are: Rayleigh number (based on gap width) up to 2 × 105; .
Role of Large-Scale Circulation in Triggering Foehns in the Hokuriku District of Japan during Midsummer

The relationships between large-scale circulation and foehns observed during midsummer in Hokuriku district, located on the Japan Sea side of central Japan, are examined using Japanese long-term reanalysis project data, with additional data from the Japan Meteorological Agency climate data assimilation system. All foehn events are classified into two types: a tropical cyclone (TC)-induced foehn and an extratropical cyclone (EC)induced foehn. The occurrence of the TC type is attributed to a combination of a typhoon and its induced teleconnection pattern, the Pacific-Japan (PJ) pattern, in the lower troposphere. Local intensification of the North Pacific high just east of Japan, accompanied by the dominance of the PJ pattern, can in turn force a typhoon track to shift westward. The northward migration of the typhoon along the western periphery of the locally enhanced high strengthens a zonal pressure gradient across central Japan, thus producing a foehn. In contrast, an upper-level teleconnection along the Asian jet serves as a prominent trigger of the occurrence of an EC-type foehn. Stationary Rossby wave packets propagating eastward along the upper-level Asian waveguide facilitate not only the westward development of the North Pacific high but also the development of an extratropical cyclone in the vicinity of the Japan Sea by leading to the equatorward advection of higher potential vorticity from high latitudes. Both developments are crucial for the reinforcement of a northwest-southeast pressure gradient in the lower troposphere around Japan, thus providing a favorable condition for a foehn event.
Growth, structure and thermal properties of Yb3+-doped NaGd(WO4)2 crystal

Yb3+ : NaGd(WO4)2 single crystal with dimensions Ø30 × 60 mm2 has been grown by the Czochralski method. XRPD experimental results show that the as-grown Yb3+ : NaGd(WO4)2 crystal belongs to the tetragonal system and the I41/a space group. The high crystalline quality of the as-grown Yb3+ : NaGd(WO4)2 crystals was confirmed by HRXRD. The effective segregation coefficient of the Yb element in Yb3+ : NaGd(WO4)2 crystal growth was measured to be 0.812 using the x-ray fluorescence method. Subsequently, the thermal properties were systematically studied by measuring the thermal expansion, specific heat and thermal diffusion coefficients. The density of the as-grown Yb3+ : NaGd(WO4)2 crystal at 22 °C was measured by using the buoyancy method with a resulting value of 7.143 g cm−3 and almost linearly decreases as the temperature increases due to the thermal expansion. Comparing the thermal properties of several tungstate crystals, we find that the Yb3+ : NaGd(WO4)2 crystal possesses relatively larger anisotropic thermal expansion and specific heat but smaller thermal conductivity than those of other tungstate crystals.
Regularization under general noise assumptions

The authors explain how the major results which were obtained recently in Eggermont et al (2009 Inverse Problems 25 115018) can be derived from a more general perspective of recent regularization theory. By pursuing this further, the authors provide a general view on regularization under general noise assumptions, including weakly and strongly controlled noise. The prospect is not to generalize previous work in this direction, but rather to envision the intrinsic structure present in regularization under general noise assumptions. In particular, the authors find variants of the discrepancy and the Lepski principle to choose the regularization parameter, albeit within different context and under different assumptions.
A moving boundary problem for periodic Stokesian Hele–Shaw flows

This paper is concerned with the motion of an incompressible, viscous fluid in a Hele–Shaw cell. The free surface is moving under the influence of gravity and the fluid is modelled using a modified Darcy law for Stokesian fluids. We combine results from the theory of quasilinear elliptic equations, analytic semigroups and Fourier multipliers to prove existence of a unique classical solution to the corresponding moving boundary problem.
Migration enhanced lateral epitaxial overgrowth of AlN and AlGaN for high reliability deep ultraviolet light emitting diodes

We report on the growth of low-defect thick films of AlN and AlGaN on trenched AlGaN/sapphire templates using migration enhanced lateral epitaxial overgrowth. Incoherent coalescence-related defects were alleviated by controlling the tilt angle of growth fronts and by allowing Al adatoms sufficient residence time to incorporate at the most energetically favorable lattice sites. Deep ultraviolet light emitting diode structures (310nm) deposited over fully coalesced thick AlN films exhibited cw output power of 1.6mW at 50mA current with extrapolated lifetime in excess of 5000hours. The results demonstrate substantial improvement in the device lifetime, primarily due to the reduced density of growth defects.
Ab initio thermodynamics of metals: Al and W

We present an ab initio pseudopotential calculation of thermodynamic properties of aluminum and tungsten. The difference of almost one order of magnitude of the experimental linear thermal expansion coefficients of these materials is well reproduced by our calculations and explained in terms of microscopic quantities. The specific heat is reported and compared with available experimental data. Mode-Gr\"uneisen parameters, Debye temperature, and temperature dependence of isothermal and adiabatic bulk modulus as well as the pressure dependence of compressibility complete the work.
Localization of distracted sound sources: Determining the role of binaural cues using unilaterally attenuated and interaurally uncorrelated signals

Six listeners were instructed to localize manipulated random noise (200‐ms duration, 20‐ms cos2‐ramp, 12 directions in the horizontal plane) in an auditory virtual environment using individual head‐related transfer functions (HRTF). In the first condition, the left headphone channel was attenuated by 20 dB. In the second condition, an interaurally uncorrelated noise was used as the test signal by filtering two uncorrelated noises with the left and right HRTF. A second random noise was used as a distractor (500‐ms duration, 20‐ms cos2‐ramp, 0° azimuth). The distractor was manipulated in the same way as the test signal. Four different signal‐to‐noise ratios (S/N): 0, −5, −7, and −10 dB (plus an unmasked condition) were tested. In condition 1, the additional level difference of 20 dB caused a lateral displacement of the auditory event in four listeners. This displacement decreased when the distractor was added. In condition 2 (uncorrelated noise), the listeners were able to estimate the left‐right direction, but frequently showed front‐back confusions. With decreasing S/N the perceived directions clustered at −90°, 0°, and 90° azimuth.
Thermal conductivity of metallic glasses

The thermal diffusivity D of three metallic glasses Fe80B20, Fe40Ni40P14B6, and Fe32Ni36Cr14P12B6 has been measured from 160 to 500 K by the laser‐flash radiometry method and the thermal conductivity K has been calculated from these data. The accuracy of D and K is 6% and 8%, respectively. The electronic contribution (Ke) to the thermal conductivity, evaluated by using the Wiedemann–Franz law, increases almost linearly with increasing temperature. The phonon thermal conductivity Kph follows the temperature dependence exhibited by all amorphous dielectrics, i.e., Kph is roughly proportional to the phonon specific heat, thus giving an approximately constant phonon mean free path. When the metalloid atom B is replaced by P or the number of chemical components in the alloy is increased, both Ke and Kph decrease, but the drop in Kph is much more significant. The phonon mean free paths for Fe80B20 and Fe40Ni40P14B6 are 14 and 12 A, respectively, which are substantially higher than the values (5–8 A) for amorpho.