Miracle-dz/UniFAR-FTUs huggingface dataset:
Multi-materials beam hardening artifacts correction for computed tomography (CT) based on X-ray spectrum estimation.

Due to the energy-dependent nature of the attenuation coefficient and the polychromaticity of the X-ray source, beam hardening effect occurs when X-ray photons penetrate through an object, causing a nonlinear projection data. When a linear reconstruction algorithm, such as filtered backprojection, is applied to reconstruct the projection data, beam hardening artifacts which show as cupping and streaks are present in the CT image. The aim of this study was to develop a fast and accurate beam hardening correction method which can deal with beam hardening artifacts induced by multi-materials objects. Based on spectrum estimation, the nonlinear attenuation process of the X-ray projection was modeled by reprojecting a template image with the estimated polychromatic spectrum. The template images were obtained by segmenting the uncorrected into different components using a simple segmentation algorithm. Numerical simulations, experimental phantom data and animal data which were acquired on a modern diagnostic CT scanner (Discovery CT750 HD, GE Healthcare, WI, USA) and a modern C-Arm CT scanner (Artis Zee, Siemens Healthcare, Forchheim, Germany), respectively, were used to evaluate the proposed method. The results show the proposed method significantly reduced both cupping and streak artifacts, and successfully recovered the Hounsfield Units (HU) accuracy.
The 2018 Census of Luminous Blue Variables in the Local Group

Luminous Blue Variables (LBVs, S Doradus variables, Hubble-Sandage variables) are evolved massive stars undergoing dramatic photometric and spectroscopic variations (Humphreys & Davidson 1994). Their general properties include high luminosities, significant mass-loss rates, variability on multiple time-scales, eruptive events, and often nebulous ejecta. Bona fide LBVs exhibit variability patterns that may take years to decades to observe. Therefore, many objects are only considered candidate LBVs (cLBVs). It is still unclear how LBVs fit into the evolutionary sequence for massive stars. The underlying physical trigger(s) of the instability is still debated. Recent research shows that LBVs could be the product of binary evolution (Smith & Tombleson 2015; Smith 2016), although this has been controversial (Humphreys et al. 2016). This research note compiles confirmed and candidate LBVs in the Milky Way and Local Group galaxies. Table 1 presents the 2018 census of (c)LBVs in the Local Group. When available, popular naming designations are given in the first two columns. Confirmed LBVs are highlighted in boldface. The third column lists the 2MASS designations, and hence coordinates, labeled with a ‘J’. ICRS coordinates are provided in cases where no 2MASS designation exist. We present optical V -band and near-infrared JHK-band magnitudes in columns 4–7, with values taken from SIMBAD (Wenger et al. 2000), 2MASS (Skrutskie et al. 2006), Rafelski et al. (2007), Humphreys et al. (2014), or Sholukhova et al. (2015). The final column lists relevant citations. In many cases, the objects are studied extensively and we made a reasonable choice for the reference. One major source of discovery for (c)LBVs beyond the Galaxy and Magellanic Clouds comes from the Local Group Galaxies Survey (Massey et al. 2007, 2016). A criterion on the cLBV membership in this census is spectroscopic confirmation for the stars to be hot or P Cygni-like. With the continuing work of the Gaia mission, we expect that the region of the upper Hertzsprung-Russell diagram where LBVs reside will be better constrained in the coming years (Smith et al. 2018). This census includes a few notable stars that are either LBVs or related objects. For example, HD 5980 underwent an LBV-like eruption and has long-term trends in its light curve that make it similar to LBVs (Koenigsberger et al. 2010). Romano’s star shows long-term variability with a spectrum changing from a B star to an WN8 spectrum (Polcaro et al. 2016). η Carinae is unusual compared to other LBVs (Davidson & Humphreys 2012).
CalcHEP 2.3: MSSM, structure functions, event generation, batchs, and generation of matrix elements for other packages

CalcHEP is a package for computation of Feynman diagrams and integration over multi-particle phase space. The main idea prescribed into CalcHEP is to make available passing on from Lagrangians to the final distributions effectively with a high level of automation. This article presents new options of CalcHEP available in version 2.3. They are a) MSSM model with different SUGRA scenarios, b) interface with PDFLIB and implementation of new MRST/CTEQ structure functions, c) realization of approach to structure functions for models with diagonal CKM, d) generation of events and interface with PYTHIA, e) calculations in non-interactive (batch) regime, f)generation of code of different matrix elements for other programs, g) many new interface facilities.
Seismic Absorption Estimation and Compensation

As seismic waves travel through the earth, the visco-elasticity of the earth’s medium will cause energy dissipation and waveform distortion. This phenomenon is referred to as seismic absorption or attenuation. In hydrocarbon reservoir description, seismic absorption can be used as an important attribute to interpret for fluid units. In seismic data processing, the information about seismic absorption can be used to enhance seismic data resolution by means of absorption compensation. The absorptive property of a medium can be described by a quality factor Q, which determines the energy decay and a velocity dispersion relationship. The quality factor and the velocity govern the propagation of seismic energy in the earth. In this thesis, four new ideas have been developed to deal with the estimation and application of seismic absorption. These ideas are detailed in four chapters respectively. By assuming that the amplitude spectrum of a seismic wavelet may be modeled by that of a Ricker wavelet, an analytical relation has been derived to estimate a quality factor from the seismic data peak frequency variation with time. This relation plays a central role in quality factor estimation problems. Quality factors with coarse resolution can be estimated from prestack common midpoint (CMP) gathers, or a post-stack single trace based on event picking. To estimate interval Q for reservoir description, a method called reflectivityguided seismic attenuation analysis is proposed. This method first estimates peak frequencies at a common midpoint location, then correlates the peak frequency with sparsely-distributed reflectivities, and finally calculates Q values from the peak frequencies at the reflectivity locations using an analytical expression. The peak frequency is estimated from the prestack CMP gather using peak frequency variation with offset (PFVO) analysis which is similar to amplitude variation with offset (AVO) analysis in implementation. The estimated Q section has the same layer boundaries of the acoustic impedance or other layer properties. Therefore, the seismic attenuation property obtained with the guide of reflectivity is easy to interpret for the purpose of reservoir description. To overcome the instability problem of conventional inverse Q filter-
Super-mouvement brownien avec catalyse

We study a general class of catalytic super-Brownian motions. Informally, such a process Z describes the evolution of a large number of small particles which move according to independent Brownian motions in and branch only when they visit a given set D (the catalyst), which may be of zero Lebesgue measure. We first construct the processus Z as a weak limit of branching particle systems. We then obtain detailed information about the continuity properties of Z Using excursion theory for Brownian motion in , we prove a representation theorem for Z outside the catalyst D. In the special case when D has zero Lebesgue measure, this representation theorem shows that a.s. for every t > 0, the measure Zt is absolutely continuous with respect to Lebesgue measure, and its density solves the heat equation outside D
High-Quality Large-Sized Single Crystals of Pb-Doped Bi 2 Sr 2 CuO 6+ δ High-T c Superconductors Grown with Traveling Solvent Floating Zone Method

High quality Pb-doped Bi2Sr2CuO6+δ (Pb-Bi2201) single crystals are grown by the traveling solvent floating zone technique, with dimensions as large as ~ 50 mm× ~ 5.0 mm× ~ 2 mm. The Pb-Bi2201 single crystals with different doping levels are obtained by the annealing process which covers a wide doping range of the overdoped region. We describe in detail the growth and annealing procedures and the characterization and physical property measurements of the Pb-Bi2201 crystals. The availability of these crystals provides a good opportunity to experimentally investigate high-Tc cuprate superconductors, particularly in the overdoped region.
Entanglement required in achieving entanglement-assisted channel capacities

Entanglement shared between the two ends of a quantum-communication channel has been shown to be a useful resource in increasing both the quantum and classical capacities for these channels. The entanglement-assisted capacities were derived assuming an unlimited amount of shared entanglement per channel use. In this paper, bounds are derived on the minimum amount of entanglement required per use of a channel, in order to asymptotically achieve the capacity. This is achieved by introducing a class of entanglement-assisted quantum codes. Codes for classes of qubit channels are shown to achieve the quantum entanglement-assisted channel capacity when an amount of shared entanglement per channel given by, E{sub Q}{sup Random}{>=}1-Q{sub E}, is provided. It is also shown that for very noisy channels, as the capacities become small, the amount of required entanglement converges for the classical and quantum capacities.
Study Abroad: Benefits, Concerns, Who Goes and Why?

The objective of the research is to investigate if certain demographics of students help explain four areas of potential improvements in predominantly short-term study abroad programs. These areas are motivation, experience enhancement, benefits from various learning activities, and students’ concerns regarding their experience. Pre-trip and post-trip surveys were conducted using logistic regression model. Our results showed that participants of a longer-term program were more likely than those in the short-term program to be expanded in their cultural understanding and global outlook. In contrast to many studies, males were found to be more motivated than females by a desire to experience foreign culture. Students with a higher GPA were found to have a more enhanced academic experience than those with a lower GPA. Finally, participants from a monocultural background were found to have a more culturally enhanced experience than the multicultural ones. The results will help improve the quality of study abroad programs.
Normal Modes of Rotating Magnetic Stars

We investigate the effect of a magnetic field on the global oscillation modes of a rotating fluid star in the magnetohydrodynamic approximation. We present general equations for the modification of any type of fluid mode due to a general magnetic field that is not aligned with the star's spin axis. In the case of any internal dipole magnetic field, we derive the equations for the frequency corrections to the r-modes. We solve for the frequency correction explicitly for the case when the internal dipole field is force-free, including the uniform density case. In the weak-field limit, the spatial form of the r-mode velocity perturbation is unchanged, but the magnitude of the frequency in the rotating frame increases.
Modeling Viscosity of Volcanic Melts With Artificial Neural Networks

Viscosity is of great importance in governing the dynamics of volcanoes, including their eruptive style. The viscosity of a volcanic melt is dominated by temperature and chemical composition, both oxides and water content. The changes in melt structure resulting from the interactions between the various chemical components are complex, and the construction of a physical viscosity model that depends on composition has not yet been achieved. We therefore train an artificial neural network (ANN) on a large database of measured compositions, including water, and viscosities that spans virtually the entire chemical space of terrestrial magmas, as well as some technical and extra‐terrestrial silicate melts. The ANN uses composition, temperature, a structural parameter reflecting melt polymerization and the alkaline ratio as input parameters. It successfully reproduces and predicts measurements in the database with significantly higher accuracy than previous global models for volcanic melt viscosities. Viscosity measurements are restricted to low and high viscosity ranges, which exclude typical eruptive temperatures. Without training data at such conditions, the ANN cannot reliably predict viscosities for this important temperature range. To overcome this limitation, we use the ANN to create synthetic viscosity data in the high and low viscosity range and fit these points using a physically motivated, temperature‐dependent viscosity model. Our study introduces a synthetic data approach for the creation of a physically motivated model predicting volcanic melt viscosities based on ANNs.
A Spectroscopic Search for AGN Activity in the Reionization Era

The ubiquity of Lyman alpha (Lyα) emission in a sample of four bright [O iii]-strong star-forming galaxies with redshifts above seven has led to the suggestion that such luminous sources represent a distinct population compared with their fainter, more numerous counterparts. The presence of Lyα emission within the reionization era could indicate that these sources created early ionized bubbles due to their unusually strong radiation, possibly because of the presence of active galactic nuclei. To test this hypothesis, we secured long integration spectra with XSHOOTER on the VLT for three sources selected to have similar luminosities and prominent excess fluxes in the IRAC 3.6 or 4.5 μm band, usually attributed to strong [O iii] emission. We secured additional spectroscopy for one of these galaxies at z = 7.15 using MOSFIRE at the Keck telescope. For the most well-studied source in our sample with the strongest IRAC excess, we detect significant nebular emission from He ii and N v indicative of a non-thermal source. For the other two sources at z = 6.81 and z = 6.85, for which no previous optical/near-infrared spectroscopy was available, Lyα is seen in one and C iii] emission in the other. Although based on a modest sample, our results further support the hypothesis that the phenomenon of intense [O iii] emission is associated preferentially with sources lying in early ionized bubbles. However, even though one of our sources at z = 7.15 suggests the presence of non-thermal radiation, such ionized bubbles may not uniquely arise in this manner. We discuss the unique advantages of extending such challenging diagnostic studies with JWST.
Perovskite Quantum Organismoids

A central characteristic of living beings is the ability to learn from and respond to their environment leading to habit formation and decision making1-3. This behavior, known as habituation, is universal among forms of life with a central nervous system, and interestingly observed even in single cellular organisms that do not possess a brain4-5. Here, we report the discovery of habituation based plasticity utilizing a perovskite quantum system by dynamical modulation of electron localization via reversible dopant incorporation. Microscopic mechanisms and pathways that enable this organismic collective charge-lattice interaction are elucidated by a combination of first-principles theory, synchrotron investigations, ab-initio dynamical simulations and in-situ environmental breathing studies. We implement a new learning algorithm inspired from the conductance relaxation behavior of perovskites that naturally incorporates habituation and demonstrate "learning to forget": a key feature of animal and human brains6. Most surprisingly, our results show that incorporating this elementary skill in learning dramatically boosts the capability of artificial cognitive systems.
Rotating hairy black holes in arbitrary dimensions

A class of exact rotating black hole solutions of gravity nonminimally coupled to a self-interacting scalar field in arbitrary dimensions is presented. These spacetimes are asymptotically locally anti-de Sitter manifolds and have a Ricci-flat event horizon hiding a curvature singularity at the origin. The scalar field is real and regular everywhere and its effective mass, coming from the nonminimal coupling with the scalar curvature, saturates the Breitenlohner-Freedman bound for the corresponding spacetime dimension. The rotating black hole is obtained by applying an improper coordinate transformation to the static one. Although both spacetimes are locally equivalent, they are globally different, as it is confirmed by the nonvanishing angular momentum of the rotating black hole. It is found that the mass is bounded from below by the angular momentum in agreement with the existence of an event horizon. The thermodynamical analysis is carried out in the grand canonical ensemble. The first law is satisfied and a Smarr formula is exhibited. The thermodynamical local stability of the rotating hairy black holes is established from their Gibbs free energy. However, the global stability analysis establishes that the vacuum spacetime is always preferred over the hairy black hole. Thus, the hairy black hole is likely to decay into the vacuum one for any temperature.
C iv black hole mass measurements with the Australian Dark Energy Survey (OzDES)

Black hole mass measurements outside the local Universe are critically important to derive the growth of supermassive black holes over cosmic time, and to study the interplay between black hole growth and galaxy evolution. In this paper, we present two measurements of supermassive black hole masses from reverberation mapping (RM) of the broad C iv emission line. These measurements are based on multiyear photometry and spectroscopy from the Dark Energy Survey Supernova Program (DES-SN) and the Australian Dark Energy Survey (OzDES), which together constitute the OzDES RM Program. The observed reverberation lag between the DES continuum photometry and the OzDES emission line fluxes is measured to be $358^{+126}_{-123}$ and $343^{+58}_{-84}$ d for two quasars at redshifts of 1.905 and 2.593, respectively. The corresponding masses of the two supermassive black holes are 4.4 × 109 and 3.3 × 109 M⊙, which are among the highest redshift and highest mass black holes measured to date with RM studies. We use these new measurements to better determine the C iv radius−luminosity relationship for high-luminosity quasars, which is fundamental to many quasar black hole mass estimates and demographic studies.
Asymptotic Normality of the QML Estimator of the EGARCH(1,1) Model

This paper investigates the asymptotic properties of the quasi-maximum likelihood estimator (QMLE) for the EGARCH model. Sufficient conditions under which the EGARCH(1,1) processes have stationary first and second order variance derivatives, and the expectation of the supremum norm of the second order log-likelihood derivative is finite are established. The existence of such moment bounds permits the establishment of the CLT of the score and the uniform SLLN of the hessian, so that the asymptotic normality of the QML estimators is proved.
Scenario-Based Microlearning Strategy for Improved Basic Science Process Skills in Self-Directed Learning

This study determined the effectiveness of scenario-based microlearning strategy in improving the basic science process skills in self-directed learning of sixth grade students. Descriptive correlational through a pre-test – posttest and survey strategies was utilized. The pretest and posttest results measured the effectiveness of the strategy in improving the basic science process skills whereas the survey results were correlated to identify the significant relationship between the students’ use of scenario-based microlearning strategy and their post-test scores. The findings indicated that respondents were very satisfied on the use of the strategy as to scenario construct and its alignment to learning style. They feel satisfied in terms of the content covered and form which revealed their very high level of planning and changing skills. The pretest and posttest showed a significant difference in all terms, except for classifying. A significant relationship was revealed between the students’ use of the strategy and their posttest scores as well as the use of the strategy and level of self-directed learning skills. The findings suggest the use of scenario-based microlearning strategy as an alternative approach in teaching science to improve the basic science process skills and self-directed learning skills of learners.
A survey for extragalactic HCN and HCO

We have surveyed 15 galaxies for HCN and HCO + J=1→0 emission and detected HCN in 12 objects and HCO + in 11. Maps were made of IC 342, M51, and M83. Since the HCN and HCO + lines require higher densities than CO J=1→0 for excitation, they probe denser gas. Strong HCO + J=3→2 emission has been found in NGC 253. Our new J=1→0 detections along with the J=3→2 data are used to estimate excitation temperatures and optical depths
Branes at conical singularities and holography

For supergavrity solutions which are the product of an anti-de Sitter space with an Einstein space X, we study the relation between the amount of supersymmetry preserved and the geometry of X. Depending on the dimension and the amount of supersymmetry, the following geometries for X are possible, in addition to the maximally supersymmetric spherical geometry: Einstein-Sasaki in dimension 2k+1, 3-Sasaki in dimension 4k+3, 7-dimensional manifolds of weak G_2 holonomy and 6-dimensional nearly Kaehler manifolds. Many new examples of such manifolds are presented which are not homogeneous and have escaped earlier classification efforts. String or M theory in these vacua are conjectured to be dual to superconformal field theories. The brane solutions interpolating between these anti-de Sitter near-horizon geometries and the product of Minkowski space with a cone over X lead to an interpretation of the dual superconformal field theory as the world-volume theory for branes at a conical singularity (cone branes). We propose a description of those field theories whose associated cones are obtained by (hyper-)Kaehler quotients.
Flavour Dynamics: CP Violation and Rare Decays

These lectures give an up to date description of CP violation and rare decays of K and B mesons and consist of ten chapters: i) Grand view of the field including CKM matrix and the unitarity triangle, ii) General aspects of the theoretical framework based on effective weak Hamiltonians, the operator product expansion and the renormalization group, iii) Particle-antiparticle mixing and various types of CP violation, iv) Standard analysis of the unitarity triangle, v) The ratio epsilon'/epsilon, vi) Rare decays K^+ -> pi^+ nu barnu and K_L to pi^0 nu barnu, vii) Express review of other rare decays, viii) CP violation in B decays, ix) A brief look beyond the Standard Model discussing in particular the models with minimal flavour violation, x) Perspectives for the coming years.