Miracle-dz/UniFAR-FTUs huggingface dataset:
CHANGE SCORES AS DEPENDENT VARIABLES IN REGRESSION ANALYSIS

Change scores have been widely criticized for their purported unreliability and for their sensitivity to regression toward the mean. These objections are shown to be unfounded under a plausible regression model for the nonequivalent control group design. This model leads to inferences that are intuitively correct, as judged by changes in means over time, while the conventional model leads to inferences that are intuitively false. Moreover, the conventional model implies that regression toward the mean within groups leads to regression toward the mean between groups, an implausible result for naturally occurring groups. Nevertheless, the conventional model may be more appropriate when there is a true causal effect of the pretest on the posttest, or when cases are assigned to groups on the basis of their pretest scores.
Surface electronic states of the partially hydrogenated diamond C ( 100 ) − ( 2 × 1 ) : H surface

Surface electronic states of the partially hydrogenated diamond $\mathrm{C}(100)\ensuremath{-}(2\ifmmode\times\else\texttimes\fi{}1):\mathrm{H}$ surface were studied by near-edge x-ray absorption fine structure and C $1s$ core level photoemission. Partially hydrogenated surfaces were prepared by synchrotron irradiation of the monohydride-terminated surface or by hydrogen adsorption on the clean surface. A new surface core-exciton state produced at a photon energy of 282.5 eV has been assigned to single dangling bonds of the partially hydrogenated surface. Monitoring this new feature has been found to be a powerful method to study hydrogen kinetics during (i) photon irradiation of a fully hydrogenated diamond surface, (ii) adsorption of atomic hydrogen on a clean diamond surface, and (iii) photon irradiation of a fully hydrogenated surface followed by thermal annealing. From the analysis of dangling-bond distribution, it follows that no preferential pairing of hydrogen on the C-C dimers occurs during hydrogen adsorption at room temperature. In contrast, thermal annealing induces pairing of the single dangling bonds into the \ensuremath{\pi}-bonded configuration, the pairing process being accompanied by hydrogen desorption. This observation suggests that the activation barrier of hydrogen thermal diffusion is only slightly lower than that of thermal desorption.
Magnetic connection from the Earth to the solar corona, flare positions and solar energetic particle observations

Solar energetic particle (SEP) events are often associated with solar flares. Such particles propagate through the interplanetary medium, where significant levels of magnetic turbulence are found. We study the magnetic connection from the Earth to the solar corona in three dimensional magnetic turbulence. In the numerical simulation, different turbulence levels and solar wind velocities can be used. Input to the simulation is from web-based data sets, and comparison is made with the solar flare observations contained in the Goes catalogue for the years 1996, 1997, 1998, following solar minimum. For this data set, we find that SEPs can reach the Earth when the difference in the heliographic longitudes of the flare and of the magnetic foot point of the Earth is 25°–30° at most. On the other hand the longitudinal angular semi-width of the magnetic field line random walk in the solar wind, when mapped to the solar corona, is found to be typically $6^\circ$–10°. The discrepancy between the two values can be explained either by the presence of a flare – associated coronal mass ejection shock, with a longitudinal semi-size of ~$20^\circ$, or by particle propagation, which could be enhanced over the field line random walk by, e.g., gyroresonant effects, or by the presence of magnetic shear between the fast and the slow streams which enhances the longitudinal spread of field lines.
A probable supernova remnant in the dwarf elliptical galaxy NGC 185

On a decouvert une nebuleuse emissive pres du cœur de la galaxie elliptique naine du Groupe Local NGC 185. Les fortes intensites des raies [SII] et [NII] par rapport a Hα suggerent qu'il s'agit probablement d'un reste de supernova. La matiere interstellaire dans NGC 185 est au moins moderement pauvre en metaux (≥1/3 solaire)
Formalizing π4(S3) ≅Z/2Z and Computing a Brunerie Number in Cubical Agda

Brunerie’s 2016 PhD thesis contains the first synthetic proof in Homotopy Type Theory (HoTT) of the classical result that the fourth homotopy group of the 3-sphere is ℤ/2ℤ. The proof is one of the most impressive pieces of synthetic homotopy theory to date and uses a lot of advanced classical algebraic topology rephrased synthetically. Furthermore, the proof is fully constructive and the main result can be reduced to the question of whether a particular "Brunerie number" β can be normalized to ±2. The question of whether Brunerie’s proof could be formalized in a proof assistant, either by computing this number or by formalizing the pen-and-paper proof, has since remained open. In this paper, we present a complete formalization in Cubical Agda. We do this by modifying Brunerie’s proof so that a key technical result, whose proof Brunerie only sketched in his thesis, can be avoided. We also present a formalization of a new and much simpler proof that β is ±2. This formalization provides us with a sequence of simpler Brunerie numbers, one of which normalizes very quickly to −2 in Cubical Agda, resulting in a fully formalized computer-assisted proof that ${\pi _4}({\mathbb{S}^3}) \cong \mathbb{Z}/2\mathbb{Z}$.
Plasmonic gradient structures of nanoparticle arrays for optical sensing applications

Driven by a demand for integrated optical sensors in structural health and environmental monitoring we present the application of plasmonic gradient structures as sensor substrate. Therefore, nanoparticle arrays of gold are fabricated by interference lithography, which exhibit localized surface plasmons (LSPs). The plasmonic properties of such nanoparticles can be tuned by altering their size. In our approach, an additional photochemical growth by exposure to HAuCl4 and light is used to manufacture gradients of nanoparticle sizes within the array. These gradients in turn induce different spectral responses depending on the illuminated region of the array gradient. To enable sensing applications, such plasmonic gradient structures are placed as a filter in front of a photodetector to allow detection of transmitted optical signals from different locations of the array. Different applications can be envisioned in this configuration: On the one hand, sensing of wavelength shifts of the illuminating light source can be enabled by comparing the photocurrents generated in adjacent sensor elements. Additionally the application of refractive index measurements is demonstrated with the same detector configuration. The change in extinction of the illuminating light at different wavelengths can be used to obtain an intensity shift at the detector elements. This shift correlates to the change of the spectral resonance conditions in the array gradient upon change of refractive index.
Three essays on the econometric analysis of high-frequency data

In three essays, this thesis deals with the econometric analysis of financial market data sampled at intraday frequencies. In particular, we focus on the dynamic and distributional modeling of high-frequency or intraday data, as well as its utilization for risk reduction in vast-dimensional portfolios. Chapter 1 presents a novel approach to model serially dependent positivevalued variables realizing a nontrivial proportion of zero outcomes. This is a typical phenomenon in financial high-frequency time series. We introduce a flexible point-mass mixture distribution, a tailor-made semiparametric specification test and a new type of multiplicative error model (MEM). Applying the proposed methodology to high-frequency cumulated trading volumes of liquid and illiquid NYSE stocks, we show that the model captures the dynamic and distributional properties of the data and is able to correctly predict future distributions. Chapter 2 addresses the problem that fixed symmetric kernel density estimators exhibit low precision for positive-valued variables with a large probability mass near zero, which is common in high-frequency data. We show that gamma kernel estimators are superior, while their relative performance depends on the specific density and kernel shape. We suggest a refined gamma kernel and a data-driven method for choosing the appropriate type of gamma kernel estimator. In a simulation study, we compare the refined estimator to the original gamma kernels and standard boundary-correction methods, demonstrating the superiority of the new approach. Chapter 3 turns to the open debate about the merits of high-frequency data in large-scale portfolio allocation. We consider the problem of constructing global minimum variance portfolios based on the constituents of the S&P 500. Covariance matrix predictions are obtained by applying a blocked realized kernel estimator, along with different smoothing windows, regularization methods and forecasting models. We show that forecasts based on high-frequency data can yield a significantly lower portfolio volatility than approaches using daily returns, implying noticeable utility gains for a risk-averse investor.
When is one experiment ‘always better than’ another?

Summary. Considering the choice between two experiments E and F, an experimenter may choose one or the other depending on the optimality criteria. However, sometimes by using the observations from E, he or she can do at least as well as by using the observations from F for every decision problem, and therefore for every inference problem as well. When that happens, it is said that experiment E is ‘always better than’F or equivalently that E is ‘sufficient for’F. The paper provides a simple explanation of what is meant by this phrase and presents a variety of situations in which one experiment E is known to be always better than an alternative F. In addition, simplifying connections between various results are also revealed. Even though these issues are important to the design of statistical experiments and to the concept of statistical information, the literature reviewed here has largely failed in communicating its results across to many researchers in these areas. One of the objectives is to fill that gap, by stressing the implications of the results, while omitting most of the technicalities that are required in their proofs.
Coding and Decoding of Topological Entities in Constraint-Based Variational Design

In top-down, constraint-based variational design environment, user expresses his design intent through a series of construction steps that will be further transferred to design variants maintained by the system. Persistent naming techniques build a bridge between design variants and user design intent. The graph-based coding and decoding method together with parameter information, presented in this paper successfully maintain the user design intent in constraint-based variational design. Besides, the energy of parameter vector field decoding method gives a mathematical definition on comparability between original model and regenerated model.
Stretching quantum wells: A method for trapping free carriers in GaAs heterostructures

We have demonstrated a method of using inhomogeneous stress to create an in-plane harmonic potential in GaAs quantum wells which works equally well for excitons and for free conduction electrons. The depth of the well can be continuously varied via an external control. This essentially provides a type of gate for controlling the motion of carriers, e.g., a two-dimensional electron gas, without using electric field.
Global dimension of factor rings

Let R be a right Noetherian ring with right global dimension bounded by 2, which is integral over its centre, and let a be a regular non-unit element in R. Then R/a; R is right hereditary if and only if a; is not in the square of any maximal ideal of R. More generally, we compare for a right Noetherian ring R which is integral over its center, the global dimension of R with the global dimension of R/(a1R + a2R + … + arR) for a regular R-sequence {ai}, which will allow us to give a considerable extension of a result of Hillman.
Diode laser based photoacoustic gas measuring instruments intended for medical research

Analysis of breath and gases emanated from skin can be used for early and non-invasive diagnosis of various kinds of diseases. Two portable, compact, photoacoustic spectroscopy based trace gas sensors were developed for the detection of methane emanated from skin and ammonia emanated from oral cavity. The light sources were distributed feedback diode lasers emitting at the absorption lines of ammonia and methane, at 1.53 μm and 1.65 μm, respectively. Photoacoustic method ensures high selectivity, therefore cross-sensitivity was negligible even with large amount of water vapor and carbon dioxide in the gas sample. In case of ammonia a preconcentration unit was used to achieve lower minimum detectable concentration. Gas sample from the oral cavity was drawn through a glass tube to the preconcentration unit that chemically bonded ammonia and released it when heated. The minimum detectable concentration of ammonia was 10 ppb for 15 s gas sampling time (gas sample of 250 cm3). For methane minimum detectable concentration of 0.25 ppm was found with 12 s integration time, and it was proved to be adequate for the detection of methane emanated from human skin and from mice. Instruments measuring methane and ammonia are currently installed at two medical research laboratories at University of Szeged and tested as instruments for non-invasive clinical trials. The aim of the measurements is to determine correlations between diseases or metabolic processes and emanated gases.
Long range forces and broken symmetries

There are reasons for believing that the gravitational constant varies with time. Such a variation would force one to modify Einstein’s theory of gravitation. It is proposed that the modification should consist in the revival of Weyl’s geometry, in which lengths are non-integrable when carried around closed loops, the lack of integrability being connected with the electromagnetic field. A new action principle is set up, much simpler than Weyl’s, but requiring a scalar field function to describe the gravitational field, in addition to the gμν. The vacuum field equations are worked out and also the equations of motion for a particle. An important feature of Weyl’s geometry is that it leads to a breaking of the C and T symmetries, with no breaking of P or of CT. The breaking does not show itself up with the simpler kinds of charged particles, but requires a more complicated kind of term in the action integral for the particle.
SOLAR-T: terahertz photometers to observe solar flare emission on stratospheric balloon flights

A new solar flare spectral component has been found with intensities increasing for larger sub-THz frequencies, spectrally separated from the well known microwaves component, bringing challenging constraints for interpretation. Higher THz frequencies observations are needed to understand the nature of the mechanisms occurring in flares. A twofrequency THz photometer system was developed to observe outside the terrestrial atmosphere on stratospheric balloons or satellites, or at exceptionally transparent ground stations. 76 mm diameter telescopes were designed to observe the whole solar disk detecting small relative changes in input temperature caused by flares at localized positions at 3 and 7 THz. Golay cell detectors are preceded by low-pass filters to suppress visible and near IR radiation, band-pass filters, and choppers. It can detect temperature variations smaller than 1 K with time resolution of a fraction of a second, corresponding to small burst intensities. The telescopes are being assembled in a thermal controlled box to which a data conditioning and acquisition unit is coupled. While all observations are stored on board, a telemetry system will forward solar activity compact data to the ground station. The experiment is planned to fly on board of long-duration stratospheric balloon flights some time in 2013-2015. One will be coupled to the GRIPS gamma-ray experiment in cooperation with University of California, Berkeley, USA. One engineering flight will be flown in the USA, and a 2 weeks flight is planned over Antarctica in southern hemisphere summer. Another long duration stratospheric balloon flight over Russia (one week) is planned in cooperation with the Lebedev Physics Institute, Moscow, in northern hemisphere summer.
Rheo-nuclear magnetic resonance of emulsion systems

This paper uses the technique of rheo-nuclear magnetic resonance (rheo-NMR) [reviewed by P. T. Callaghan, Rep. Prog. Phys. 62, 599–670 (1999)] to perform a systematic study of emulsion rheology. Rheo-NMR uses NMR velocimetry to produce velocity maps, from which it is possible to quantify rheological parameters, with apparent wall slip being measured directly. The study is initially conducted on silicone oil-in-water emulsions. Xanthan gum, an important emulsion thickener and stabilizer in the food industry, is then investigated. Finally, the technique is applied to a commercial mayonnaise, which is a complex product comprising a concentrated oil in water emulsion with various thickeners and stabilizers in the continuous phase. Rheological parameters (based on either a power-law fluid or a Hershel–Bulkley analysis) and apparent slip characteristics are extracted from the velocity maps for these materials, across a wide range of shear rates. Comparison with conventional rheological measurement and analysis .
Atmospheric Optical Phenomena and Radiative Transfer

We present simple radiative transfer models for the radiance and color of atmospheric optical phenomena. Skylight, halos, and rainbows are treated as singly scattered sunlight that is depleted by scattering as it passes through a plane-parallel atmosphere and a vertical rain shaft or a geometrically thin cloud layer. Skylight in a molecular atmosphere grades from deep blue at the zenith to pale blue near the horizon whenever the solar zenith angle ϕsun ≤ 80°. Skylight near the horizon is orange resulting from wavelength-dependent scattering by air molecules and aerosol particles through a long oblique path through the atmosphere when the sun is low in the sky (ϕsun ≥ 85°). Halos (and coronas) seen through clouds facing the sun are brightest for cloud optical depth τcld ≈ cos(ϕsun), and fade to obscurity for τcld ≥ 5. Rainbows (and glories), seen by light that is backscattered from clouds, also appear most dramatic when 0.2 ≤ τcld ≤ 1, but remain visible even in the thickest clouds.
Pure bending strains of Nb3Sn wires

This paper presents in detail recent pure bending strain investigations of ITER Nb3Sn wires including a pure bending device development, bending effects on the critical currents and their model analyses. The pure bending test device allows applying a uniform bending over a large range of bending strain on a strand sample under a large electromagnetic Lorentz force. Pure bending characteristics of five different Nb3Sn wires including three internal tin and two bronze wires were tested and evaluated with a newly developed integrated model that accounts for neutral axis shift, current transfer length, mechanical filament breakage and uniaxial strain release due to the applied bending load.
The Reliability and Validity of the Turkish Version of Smartphone Impact Scale

The Smartphone Impact Scale (SIS) was originally developed in English to determine the cognitive, affective, social, and behavioral impacts of smartphones. This study aimed to translate and cross-culturally adapt the SIS instrument into Turkish and investigate its psychometric properties. Two hundred and sixty-four young and middle-aged adults (186 females) with a mean age of 36.24 years (SD = 14.93; range, 18–65 years) were included. For cross-cultural adaptation, two bi-lingual translators used the back-translation procedure. Within a 5-to-7-day period after the first assessment, the participants completed the Turkish version of SIS (SIS-T) to evaluate test-retest reliability. Cronbach’s alpha (α) was used to assess internal consistency. The correlation between the Turkish version of the Smartphone Addiction Scale (SAS-T) and the Nottingham Health Profile was determined to check the validity. The SIS-T had a high-level internal consistency (α = 0.86) and test-retest reliability (ICC2,1 = 0.56 to 0.89 for subscales). The SIS-T subscales were correlated with the SAS-T (r = 0.31 to 0.66, p < 0.01), indicating a good concurrent validity. The results show that the SIS-T is semantically and linguistically adequate to determine smartphones' cognitive, affective, social, and behavioral impacts on young and middle-aged adults. Good internal validity and test-retest reliability of the SIS-T were defined to evaluate the impacts of smartphones among Turkish-speaking young and middle-aged adults.
Preparation of Thick Pb(Zr, Ti)O3 (PZT) Film by Electrostatic Spray Deposition (ESD) for Application in Micro-System Technology

A Pb(Zr, Ti)O3 (PZT) thick film was prepared by electrostatic spray deposition (ESD) using a sol-gel solution as the precursor. The steady spray, which is suitable for large area and uniform PZT film deposition, can be achieved at an applied electric potential of 4500 volts and solution flow rate of 0.6 ml/h for the 0.4 M sol-gel PZT solution. The use of 100-nm-thick sol-gel PZT as a buffer layer affected the ESD-deposited PZT film's nucleation and growth behavior and enhanced the PZT (100) orientation. By using sol-gel PZT as the intermediate layer to increase the density of the ESD-deposited PZT film, the relative dielectric constant of as high as 960 can be achieved. Our primary results proved that ESD is a promising method for the preparation of thick PZT films with good piezoelectric properties.
Poiseuille flow in a fluid overlying a porous medium

This paper numerically investigates the instability of Poiseuille flow in a fluid overlying a porous medium saturated with the same fluid. A three-layer configuration is adopted. Namely, a Newtonian fluid overlying a Brinkman porous transition layer, which in turn overlies a layer of Darcy-type porous material. It is shown that there are two modes of instability corresponding to the fluid and porous layers, respectively. The key parameters which affect the stability characteristics of the system are the depth ratio between the porous and fluid layers and the transition layer depth.
Flux paths and flux transfer mechanism in the T joints of three phase transformer cores

A better understanding of flux behavior within specific regions of a transformer core can lead to improved core design and magnetic efficiency. Flux paths and the flux transfer mechanisms have been determined for two practical T joints of different designs employed in two similar three-phase three limbed transformer cores. Each core was energized at three different core flux densities. The instantaneous flux density patterns both parallel to and perpendicular to the rolling plane of the laminations are presented in graphical and vectorial forms for both types of T joints. By "freezing" the continually changing flux pattern within a T joint, it was possible to trace individual flux paths through the joint and to determine the basic flux transfer mechanism between adjacent laminations. Flux behavior within the joints shows that while its path is dependent on both T joint design and core flux density, the basic flux transfer mechanism remains unchanged in both T joints and at all core flux densities.