Miracle-dz/UniFAR-FTUs huggingface dataset:
The Resilience of the Poor: A Markov Chain Analysis of Heterogeneity in Subjective Poverty

This paper studies the dynamics of subjective poverty in urban Ethiopia. Poverty is measured as three points ordinal scales: rich, borderline and poor. We use a multinomial logit Markov chain with alternative speciﬁcations of unobserved heterogeneity as a random eﬀect, which depends on: households and poverty departure state, household and transition poverty proﬁle, and household heterogeneity only. We identify transitory and permanent eﬀects, and frame-of-reference bias. We ﬁnd that (i) human capital is a strong determinant of upward poverty, with intensity eﬀect: the higher the level of schooling, the lower the probability of transiting to poor state; (ii) larger households enjoy greater economies of scale but the demographic structure of households matters; (iii) social capital has a positive eﬀect on the downward mobility of poverty; (iv) own consumption raises self-welfare rating; (v) the initial level of poverty is an important determinant of future poverty.
Excitation mechanisms of individual Cd Te ∕ Zn Te quantum dots studied by photon correlation spectroscopy

Systematic measurements of auto- and cross-correlations of photons emitted from individual $\mathrm{Cd}\mathrm{Te}∕\mathrm{Zn}\mathrm{Te}$ quantum dots under pulsed excitation were used to elucidate nonresonant excitation mechanisms in this self-assembled system. Memory effects extending over a few excitation pulses have been detected in agreement with previous reports and quantitatively described by a rate equation model, fitting a complete set of correlation and PL intensity results. The important role of single carrier trapping in the quantum dot was established. An explanation was suggested for the unusually wide antibunching dip observed previously in $X\text{\ensuremath{-}}X$ autocorrelation experiments on quantum dots under cw excitation.
A general explanation on the correlation of dark matter halo spin with the large-scale environment

Both simulations and observations have found that the spin of halo/galaxy is correlated with the large scale environment, and particularly the spin of halo flips in filament. A consistent picture of halo spin evolution in different environments is still lacked. Using N-body simulation we find that halo spin with its environment evolves continuously from sheet to cluster, and the flip of halo spin happens both in filament and nodes. For the flip in filament can be explained by halo formation time and the migrating time when its environment changes from sheet to filament. For low-mass haloes, they form first in sheets and migrate into filaments later, so their mass and spin growth inside filament are lower, and the original spin is still parallel to filament. For massive haloes, they migrate into filaments first, and most of their mass and spin growth are obtained in filaments, so the resulted spin is perpendicular to filament. Our results well explain the overall evolution of cosmic web in the cold dark matter model and can be tested using high-redshift data. The scenario can also be tested against alternative models of dark matter, such as warm/hot dark matter, where the structure formation will proceed in a different way.
Modelling mechanical interfaces experiencing micro-slip/slap

Surface-to-surface contact interfaces significantly affect structural behaviour. Therefore, accurate modelling of the stiffness and damping characteristics of such interfaces is crucial for dynamic response analysis of assembled structures. Due to the development of nonlinear interactions, such as slip and slap mechanisms, modelling and analysis of the contact interfaces is a challenging task. The nonlinear effects of the slip and slap mechanisms need to be considered in interface models particularly when the amplitude of the structural response is high. This article considers finite element (FE) modelling of a compound structure containing a surface-to-surface contact interface, i.e. a bolted lap-joint. The joint, modelled using thin-layer element theory, experiences micro-slips/slaps under extreme loading conditions of the structure and to take into account these behaviours, the thin-layer element is assumed to behave in a nonlinear manner. In order to identify the nonlinear uncertainties in the joint interface, the real structure is subjected to vibrational testing, and its dynamical behaviour at different loading levels is extracted. The parameters of interfacial elements are tuned in such a way that the resultant FE model predicts the experimental results with a high accuracy.
A model of high-energy emission from jets of microquasars of Population III

Current research indicates that the radiation of the first stars alone would not have been suficient to ionize the intergalactic medium on long distances because of the high columnar density of the clouds in which they formed. It becomes necessary, then, to explore other alternatives for the reionization. The study of the contribution of the first accreting binary systems to the reionization and heating of the intergalactic medium requires the formulation of a concrete model for the first microquasars. We aim at constructing a consistent model for jets of microquasars where the donor star is of Population III. We calculate the spectral energy distribution of the radiation produced by the relativistic particles in the jets, within the framework of a lepto-hadronic model. In addition, we study the interaction between the jets and the early intergalactic medium. All calculations have been computed for a cosmological redshift value z = 10. We determine that jets of microquasars of Population III are sources of intense gamma radiation in regions of particle acceleration near the compact object and in the terminal jets.
Adaptive clinical trial designs for phase I cancer studies

Adaptive clinical trials are becoming increasingly popular research designs for clinical investigation. Adaptive designs are particularly useful in phase I cancer studies where clinical data are scant and the goals are to assess the drug dose-toxicity profile and to determine the maximum tolerated dose while minimizing the number of study patients treated at suboptimal dose levels. In the current work we give an overview of adaptive design methods for phase I cancer trials. We find that modern statistical literature is replete with novel adaptive designs that have clearly defined objectives and established statistical properties, and are shown to outperform conventional dose finding methods such as the 3+3 design, both in terms of statistical efficiency and in terms of minimizing the number of patients treated at highly toxic or nonefficacious doses. We discuss statistical, logistical, and regulatory aspects of these designs and present some links to non-commercial statistical software for implementing these methods in practice. MSC 2010 subject classifications: Primary 62L05, 62L10, 62L12; secondary 62L20.
Experimental study of the spatial distribution of quantum correlations in confocal optical parametric oscillator

An experiment is designed, in the continuous wave regime, in order to produce and analyze images at the quantum level. This system is based on an optical parametric oscillator (OPO), and uses the fact that parametric down-conversion produces signal and idler photons, which are correlated in time and position, all the quality required to produce a quantum image. The crystal is placed in a transverse degenerate optical cavity, which preserves the spatial properties of the parametric process. In this paper, confocal cavity is studied, which is resonant for all transverse modes of the same parity.
In an Ising model with spin-exchange dynamics damage always spreads

We investigate the spreading of damage in Ising models with Kawasaki spin-exchange dynamics which conserves the magnetization. We first modify a recent master equation approach to account for dynamic rules involving more than a single site. We then derive an effective-field theory for damage spreading in Ising models with Kawasaki spin-exchange dynamics and solve it for a two-dimensional model on a honeycomb lattice. In contrast to the cases of Glauber or heat-bath dynamics, we find that the damage always spreads and never heals. In the long-time limit the average Hamming distance approaches that of two uncorrelated systems. These results are verified by Monte Carlo simulations.
Bar Diagnostics in Edge-on Spiral Galaxies. II. Hydrodynamical Simulations

We develop diagnostics based on gas kinematics to identify the presence of a bar in an edge-on spiral galaxy and determine its orientation. We use position-velocity diagrams (PVDs) obtained by projecting edge-on two-dimensional hydrodynamical simulations of the gas flow in a barred galaxy potential. We show that when a nuclear spiral is formed, the presence of a gap in the PVDs, between the signature of the nuclear spiral and that of the outer parts of the disk, reliably indicates the presence of a bar. This gap is due to the presence of shocks and inflows in the simulations, leading to a depletion of the gas in the outer bar region. If no nuclear spiral signature is present in a PVD, only indirect arguments can be used to argue for the presence of a bar. The shape of the signature of the nuclear spiral, and to a lesser extent that of the outer bar region, allows a determination of the orientation of the bar with respect to the line of sight. The presence of dust can also help to discriminate between viewing angles on either side of the bar. Simulations covering a large fraction of parameter space constrain the bar properties and mass distribution of observed galaxies. The strongest constraint comes from the presence or absence of the signature of a nuclear spiral in the PVD.
Acoustic signatures in the primary microwave background bispectrum

If the primordial fluctuations are non-Gaussian, then this non-Gaussianity will be apparent in the cosmic microwave background (CMB) sky. With their sensitive all-sky observation, MAP and Planck satellites should be able to detect weak non-Gaussianity in the CMB sky. On a large angular scale, there is a simple relationship between the CMB temperature and the primordial curvature perturbation: $\ensuremath{\Delta}T/T=\ensuremath{-}\ensuremath{\Phi}/3. $ On smaller scales, however, the radiation transfer function becomes more complex. In this paper, we present the angular bispectrum of the primary CMB anisotropy that uses the full transfer function. We find that the bispectrum has a series of acoustic peaks that change a sign and a period of acoustic oscillations is twice as long as that of the angular power spectrum. Using a single non-linear coupling parameter to characterize the amplitude of the bispectrum, we estimate the expected signal-to-noise ratio for COBE, MAP, and Planck experiments. In order to detect the primary CMB bispectrum by each experiment, we find that the coupling parameter should be larger than 600, 20, and 5 for COBE, MAP, and Planck experiments, respectively. Even for the ideal noise-free and infinitesimal thin-beam experiment, the parameter should be larger than 3. We have included effects from the cosmic variance, detector noise, and foreground sources in the signal-to-noise estimation. Since the simple inflationary scenarios predict that the parameter is an order of 0.01, the detection of the primary bispectrum by any kind of experiments should be problematic for those scenarios. We compare the sensitivity of the primary bispectrum to the primary skewness and conclude that, when we can compute the predicted form of the bispectrum, it becomes a ``matched filter'' for detecting the non-Gaussianity in the data and a much more powerful tool than the skewness. For example, we need the coupling parameter of larger than 800, 80, 70, and 60 for each relevant experiment in order to detect the primary skewness. We also show that MAP and Planck can separate the primary bispectrum from various secondary bispectra on the basis of the shape difference. The primary CMB bispectrum is a test of the inflationary scenario and also a probe of the non-linear physics in the very early universe.
Uncertainty reduction: a framework for the integration of visual motion

Motion uncertainty arises whenever there is ambiguity in local velocity vector assignment, such as along a straight contour or in a textureless region. Motion uncertainty can be quantified by computing the entropy of the corresponding velocity probability distribution. We propose a new framework for the integration of visual motion where the objective is the reduction of motion uncertainty. Based on this approach, we have developed a model that searches for the proper extent of motion integration in order to minimize motion entropy. By modeling our task as a multi-stage stochastic optimization problem, the control structure for motion integration can be inferred through dynamic programming. Results from initial experiments demonstrate that our model is capable of analyzing image sequences containing the aperture problem and textureless regions.
Turbulent Molecular Cloud Cores: Rotational Properties

The rotational properties of numerical models of centrally condensed, turbulent molecular cloud cores with velocity fields that are characterized by Gaussian random fields are investigated. It is shown that the observed line width-size relationship can be reproduced if the velocity power spectrum is a power law with P(k) ∝ kn and n = -3 to -4. The line-of-sight velocity maps of these cores show velocity gradients that can be interpreted as rotation. For n = -4, the deduced values of angular velocity Ω = 1.6 km s-1 pc-1×(R/0.1 pc)-0.5, and the scaling relations between Ω and the core radius R are in very good agreement with the observations. As a result of the dominance of long-wavelength modes, the cores also have a net specific angular momentum with an average value of J/M = 7 × 1020 × (R/0.1 pc)1.5 cm2 s-1 with a large spread. Their internal dimensionless rotational parameter is β ≈ 0.03, independent of the scale radius R. In general, the line-of-sight velocity gradient of an individual turbulent core does not provide a good estimate of its internal specific angular momentum. We find however that the distribution of the specific angular momenta of a large sample of cores which are described by the same power spectrum can be determined very accurately from the distribution of their line-of-sight velocity gradients Ω using the simple formula j = pΩR2, where p depends on the density distribution of the core and has to be determined from a Monte Carlo study. Our results show that for centrally condensed cores the intrinsic angular momentum is overestimated by a factor of 2-3 if p = 0.4 is used.
Supersymmetry and Brane Cosmology

We consider a five-dimensional brane world scenario where the fifth dimension is compactified on S1/Z2. We show that the familiar four-dimensional cosmology on our brane is easily recovered during a primordial stage of inflation if supersymmetry is exploited. Even if some vacuum energy density appears localized on our three brane, heavy supersymmetric bulk fields adjust themselves and acquire a nontrivial configuration along the extra-dimension. This phenomenon redistributes uniformly the energy density across the bulk and the resulting energy-momentum tensor does not display any singularity associated to the initial localized energy density on our three-brane. No jumps across the brane are present for the derivatives of the metric and Einstein's equations are solved by constant solutions along the fifth dimension. Our findings make it clear that cosmological phenomena in the supersymmetric brane world scenario must be studied taking properly into account bulk supersymmetric states. This comment is particularly relevant when applied to (super)gravity since in supersymmetric brane world scenarios, even though chiral matter and gauge fields may be restricted to live on boundaries, gravity multiplets always propagate in the bulk.
Hong-Ou-Mandel interferometer with cavities: Theory

We study the number of coincidences in a Hong-Ou-Mandel interferometer exit whose arms have been supplemented with the addition of one or two optical cavities. The fourth-order correlation function at the beam splitter exit is calculated. In the regime where the cavities lengths are larger than the one-photon coherence length, photon coalescence and anticoalescence interference is observed. Feynman's path diagrams for the indistinguishable processes that lead to quantum interference are presented. The construction of an optical XOR gate is discussed as an application for the Hong-Ou-Mandel interferometer with two cavities.
A supplementary list of southern nearby dwarf galaxy candidates

To improve the census of the Local Volume galaxies, we carried out a systematic search for nearby dwarf galaxies in a declination range of based on the ESO/SERC film copies. As a result, we present a list of 81 nearby dwarf galaxy candidates of low surface brightness which have angular diameters . Half of the objects have been found for the first time. This sample may be considered as supplementary to our list of 95 southern nearby dwarf galaxy candidates (A&AS, 1998, 127, 409) which have been detected in the same declination range around the known Local Volume galaxies.
Explanation of Observed Features of Self-Organization in Traffic Flow

Based on simulations with the ``intelligent driver model'', a microscopic traffic model, we explain the recently discovered transition from free over ``synchronized'' traffic to stop-and-go patterns [B. S. Kerner, Phys. Rev. Lett. 81, 3797 (1998)]. We obtain a nearly quantitative agreement with empirical findings such as the ``pinch effect'', the flow-density diagram, the emergence of stop-and-go waves from nonhomogeneous congested traffic, and the dimensions of their wavelength.
Gaia-derived luminosities ofKeplerA/F stars and the pulsator fraction across the δ Scuti instability strip

We study the fraction of stars in and around the {\delta} Scuti instability strip that are pulsating, using {\em Gaia} DR2 parallaxes to derive precise luminosities. We classify a sample of over 15,000 {\em Kepler} A and F stars into {\delta} Sct and non-{\delta} Sct stars, paying close attention to variability that could have other origins. We find that 18 per cent of the {\delta} Sct stars have their dominant frequency above the Kepler long-cadence Nyquist frequency (periods < 1 hr), and 30 per cent have some super-Nyquist variability. We analyse the pulsator fraction as a function of effective temperature and luminosity, finding that many stars in the {\delta} Sct instability strip do not pulsate. The pulsator fraction peaks at just over 70 per cent in the middle of the instability strip. The results are insensitive to the amplitude threshold used to identify the pulsators. We define a new empirical instability strip based on the observed pulsator fraction that is systematically hotter than theoretical strips currently in use. The stellar temperatures, luminosities, and pulsation classifications are provided in an online catalogue.
An all sky analysis of polarization in the microwave background

Using the formalism of spin-weighted functions we present an all-sky analysis of polarization in the Cosmic Microwave Background (CMB). Linear polarization is a second-rank symmetric and traceless tensor, which can be decomposed on a sphere into spin $\pm 2$ spherical harmonics. These are the analog of the spherical harmonics used in the temperature maps and obey the same completeness and orthogonality relations. We show that there exist two linear combinations of spin $\pm 2$ multipole moments which have opposite parities and can be used to fully characterize the statistical properties of polarization in the CMB. Magnetic-type parity combination does not receieve contributions from scalar modes and does not cross-correlate with either temperature or electric-type parity combination, so there are four different power spectra that fully characterize statistical properties of CMB. We present their explicit expressions for scalar and tensor modes in the form of line of sight integral solution and numerically evaluate them for a representative set of models. These general solutions differ from the expressions obtained previously in the small scale limit both for scalar and tensor modes. A method to generate and analyze all sky maps of temperature and polarization is given and the optimal estimators for various power spectra and their corresponding variances are discussed.
Statistical properties of geomagnetic measurements as possible precursors for magnetic storms

Records of geomagnetic measurements have been analyzed looking for evidences of possible precursors for magnetic storms. With this objective, the main magnetic storms in the period 1998-2002 have been located in Dst index record. Periods immediately before storms and periods well before them were studied by applying a method recently introduced in the literature. Statistical properties of both types of periods have been compared. One of the compared quantities was the slope of the power laws that have been found for some relevant distributions. A systematic deviation between slope distributions was found. This might be the fingerprint of a non self-organized component in records. There has also been found a correlation between slope values and the corresponding storm intensities, which could serve as a probabilistic approach to magnetic storms forecasting. Data is from the low latitude Vassouras Magnetic Observatory.
COP26 and the dynamics of anti‐fossil fuel norms

Notwithstanding the clear contribution of fossil fuel production and consumption to global greenhouse gas emissions, fossil fuels have remained largely outside the focus of the international regime established by the United Nations Framework Convention on Climate Change. The 2021 Glasgow Climate Change Conference (COP26) marked an important change, however, with fossil fuels featuring prominently in the intergovernmental negotiations as well as on the side‐lines of the conference. Here we discuss these developments as a site for contestations around “anti‐fossil fuel norms. ” We argue that anti‐fossil fuel norms are increasingly being adopted and institutionalized. However, ongoing contestation among proponents and opponents of measures to tackle fossil fuels raises important questions over the specific content of emerging norms, the role of the fossil fuel industry in climate governance, the extent to which these norms “fit” with their broader normative context, and the conditions of North–South cooperation in which such norms are to be implemented.
Bayesian cluster analysis

A parametric model for partitioning individuals into mutually exclusive groups is given. A Bayesian analysis is applied and a loss structure imposed. A model-dependent definition of a similarity inatrix is proposed and estimates based on this matrix are justified in a decision-theoretic framework. Some existing cluster analysis techniques are derived as special limiting cases. The results of the procedure applied to two data sets are compared with other analyses.