Miracle-dz/UniFAR-FTUs huggingface dataset:
A COMPARISON OF PARAMETER ESTIMATION OF LOGISTIC REGRESSION MODEL BY MAXIMUM LIKELIHOOD, RIDGE REGRESSION, MARKOV CHAIN MONTE CARLO METHODS

The goal of this research is to estimate the parameter of logistic regression model. The coefficient parameter is evaluated by maximum likelihood, ridge regression, markov chain monte carlo methods. The logistic regression is considered the correlation between binary dependent variable and 2, 3, and 4 independent variables which is generated from normal distribution, contaminated normal distribution, and t distribution. The maximum likelihood estimator is estimated by differential the log likelihood function with respect to the coefficients. Ridge regression is to choose the unknown ridge parameter by cross-validation, so ridge estimator is evaluated on a form of maximum likelihood method by adding ridge parameter. The markov chain monte carlo estimator can approximate from Gibbs sampling algorithm by the posterior distribution based on a probability distribution and prior probability distribution. The performance of these method is compare by percentage of predicted accuracy value. The results are found that ridge regression are satisfied when the independent variables are simulated from normal distribution, and the maximum likelihood outperforms on the other distributions.
Empty Categories Help Parse the Overt

This paper is concerned with whether deep syntactic information can help surface parsing, with a particular focus on empty categories. We consider data-driven dependency parsing with both linear and neural disambiguation models. We find that the information about empty categories is helpful to reduce the approximation error in a structured prediction based parsing model, but increases the search space for inference and accordingly the estimation error. To deal with structure-based overfitting, we propose to integrate disambiguation models with and without empty elements. Experiments on English and Chinese TreeBanks indicate that incorporating empty elements consistently improves surface parsing.
TPA: Two Phase Approximation for Random Walk with Restart

—Given a large graph, how can we determine similarity between nodes in a fast and accurate way? Random walk with restart (RWR) is a popular measure for this purpose and has been exploited in numerous data mining applications including ranking, anomaly detection, link prediction, and community detection. However, previous methods for computing exact RWR require prohibitive storage sizes and computational costs, and alternative methods which avoid such costs by computing approximate RWR have limited accuracy, especially in ranking. In this paper, we propose TPA, a fast, scalable, and highly accurate method for computing approximate RWR on large graphs. TPA exploits two important properties in RWR: 1) Nodes close to a seed node are likely to be revisited in following steps due to block-wise structure of many real graphs, and 2) RWR scores of nodes which reside far from the seed node are proportional to their PageRank scores. Based on these two properties, TPA divides approximate RWR problem into two subproblems called neighbor approximation and stranger approximation. In the neighbor approximation, TPA estimates RWR scores of nodes close to the seed based on scores of few early steps from the seed. In the stranger approximation, TPA estimates RWR scores for nodes far from the seed using their PageRank. The stranger and neighbor approximations are conducted in the preprocessing phase and the online phase, respectively. Through extensive experiments, we show that TPA requires 1140 × less time with 20 × less memory space than other state-of-the-art methods for the preprocessing phase. In the online phase, TPA computes approximate RWR up to 150 × faster than existing methods with 6 × lower L1 norm error and 3 . 5 × lower rank error.
Tradeoff between insensitivity to depth-induced spherical aberration and resolution of 3D fluorescence imaging due to the use of wavefront encoding with a radially symmetric phase mask

Previously, a wavefront encoded (WFE) imaging system implemented using a squared cubic (SQUBIC) phase mask has been verified to reduce the sensitivity of the imaging system to spherical aberration (SA). The strength of the SQUBIC phase mask and, as consequence, the performance of the WFE system are controlled by a design parameter, A. Although the higher the A-value, the more tolerant the WFE system is to SA, this is accomplished at the expense of the effective imaging resolution. In this contribution, we investigate this tradeoff in order to find an optimal A-value to balance the effect of SA and loss of resolution.
Chaotic oscillations of a single cavitating bubble immersed in a maxwell liquid

In the present work we develop a mathematical model for a bubble immersed in a Maxwell fluid insonified by an ultrasonic field. As in previous works we wanted to see the effect of the viscoelasiticy in the overall behavior of the bubble in time. With a modified Rayleigh-Plesset equation we obtain the evolution of radius in time, for different Deborah and Reynolds Numbers. Of interest the phase space graphs that show the chaotic oscillations for different values of the parameters, and how these parameters can be used as controllers of the oscillations. For a more complete analysis we perform a Perturbation Multiple Scale technique to get a frequency analysis, which can demonstrate how the parameters might modulate the resonance. INTRODUCTION With increasing engineering applications that use inertial cavitation, new kinds of fluids are needed to fulfill the properties required. Thus experiments with polymeric liquids in [1], showed the necessity of rheological models that focused on the elasticity properties. In [2] the elasticity in the liquid delay the collapse of the bubble and in [3] the rheological parameters are fundamental for the oscillations and collapse of bubbles. In [4] display the frequency response curves as function of the maximum pressures and the initial radiuses of bubbles. In [5] taking into account the compressibility of the bulk liquid together the viscoelastic properties of the liquid, new regimes of oscillations are found for low Reynolds numbers. The works [6, 7] show two viscoelastic models for the oscillations of a bubble with the Maxwell and Jeffries liquids, they provide a perturbation analysis obtaining the frequency response curves. First in [8] for an Oldroyd viscoelastic model and then in [9] for an Upper Convective Maxwell model, chaotic oscillations are present for Deborah numbers higher than 4, regardless of the damping factors. A complete account of all the previous works and applications can be found in [7]. With this background we propose a modified Rayleigh-Plesset equation for a single bubble immersed in a simple Maxwell fluid. This model can be set for different Deborah and Reynolds Numbers to first obtain the evolution of radius and its chaotic oscillations numerically and second to find the frequency response curves using the Multiple Scale Analysis. NOMENCLATURE a [-] Non dimensional amplitude a [-] Real part in perturbation analysis A [-] Constant for the solution proposed De [-] Deborah Number f [-] Non dimensional frequency pl [N/m] Liquid pressure pA [N/m] Driving pressure p∞ [N/m] Ambient pressure pg [N/m] Gas pressure inside the bubble pg0 [N/m] Initial gas pressure inside the bubble PA [-] Non dimensional driving pressure R [m] Bubble radius r [m] Radial coordinate Re [-] Reynolds Number ? ̅? [-] Non dimensional bubble radius s [-] Non dimensional spatial integral over radial stress S [Pa/m ] Spatial integral over radial stress t [s] time Tn [s] Characteristic time u [-] Time scales u ́ [-] Perturbation variable We [m] Weber number x [-] Relative amplitude in perturbation analysis
Time-inconsistent consumption-investment problem for a member in a defined contribution pension plan

In this paper, we investigate the consumption-investment problem for a member of the defined contribution pension plan with non-constant time preferences. The aim of the member is to maximize the discounted utility of the consumption. It leads to a time-inconsistent control problem in the sense that the Bellman optimality principle does no longer hold. In our model, the contribution rate is assumed to be a fixed proportion of the scheme member's salary, and the pension fund can be invested in a risk-free asset, an index bond and a stock whose return follows a geometric Brownian motion. Two utility functions are considered: the power utility and the logarithmic utility. We characterize the time-consistent equilibrium consumption-investment strategies and the value function in terms of a solution of an integral equation in both situations. The existence and uniqueness of the solution is verified and the approximation of the solution is obtained. We present some numerical results of the equilibrium consumption rate and equilibrium investment policy with three types of discount functions.
CFD Based Aerodynamic Modeling To Study Flight Dynamics Of A Flapping Wing Micro Air Vehicle

CFD BASED AERODYNAMIC MODELING TO STUDY FLIGHT DYNAMICS OF A FLAPPING WING MICRO AIR VEHICLE ALOK ASHOK REGE, M.S. The University of Texas at Arlington, 2012 Supervising Professors: Kamesh Subbarao and Brian H Dennis The demand for small unmanned air vehicles, commonly termed micro air vehicles or MAV’s, is rapidly increasing. Driven by applications ranging from civil search-and-rescue missions to military surveillance missions, there is a rising level of interest and investment in better vehicle designs, and miniaturized components are enabling many rapid advances. The need to better understand fundamental aspects of flight for small vehicles has spawned a surge in high quality research in the area of micro air vehicles. These aircraft have a set of constraints which are, in many ways, considerably different from that of traditional aircraft and are often best addressed by a multidisciplinary approach. Fast-response non-linear controls, nano-structures, integrated propulsion and lift mechanisms, highly flexible structures, and low Reynolds aerodynamics are just a few of the important considerations which may be combined in the execution of MAV research. The main objective of this thesis is to derive a consistent nonlinear dynamic model to study the flight dynamics of micro air vehicles with a reasonably accurate
Exploring the Hubbard model with ultracold fermionic atoms in an optical lattice

In this thesis, experimental studies of the many-body properties of the FermiHubbard model with ultracold atoms are presented. By trapping fermionic alkali atoms close to zero temperature in an optical lattice we have been able to explore strongly correlated phases of the model. The purity of this system and the high degree of control over the relevant parameters are unique advantages when compared to solid state samples. In particular, the direct control over the interaction strength led to the rst observation of a fermionic Mott insulator. It is identi ed by the suppression of doubly occupied lattice sites, a strong reduction of the compressibility inferred from the response of double occupancy to atom number increase and the appearance of a gapped mode in the excitation spectrum. In order to perform conductivity measurements a new technique has been developed. We have directly observed the motion of the atomic cloud in the periodic potential after a sudden displacement of the trapping potential. The in uence of attractive interaction on the transport properties has been investigated. We nd that strong attraction between the particles suppresses conductivity which we attribute to the formation of local pairs. The slow intrinsic timescales and the decoupling from the environment make ultracold atoms an ideal candidate for observing non-equilibrium dynamics. We have studied the decay of arti cially created double occupancies in the repulsive Hubbard model. Time-resolved measurements allow us to extract their normalised lifetime, which depends exponentially on the ratio of on-site interaction energy to kinetic energy. We conclude that the dominant relaxation mechanism is a high order scattering process involving several single fermions as scattering partners. This thesis demonstrates that cold atoms in optical lattices are a useful tool for the investigation of solid state phenomena. Further progress towards the observation of quantum magnetism has been facilitated by continuous improvements of the experimental techniques demonstrated here.
SIR epidemics with stages of infection

Abstract In this paper we are concerned with a stochastic model for the spread of an epidemic in a closed homogeneously mixing population when an infective can go through several stages of infection before being removed. The transitions between stages are governed by either a Markov process or a semi-Markov process. An infective of any stage makes contacts amongst the population at the points of a Poisson process. Our main purpose is to derive the distribution of the final epidemic size and severity, as well as an approximation by branching, using simple matrix analytic methods. Some illustrations are given, including a model with treatment discussed by Gani (2006).
SFEM for rubber‐like materials at large deformations

This paper investigates the uncertainty of hyper‐elastic model, by random material parameters as stochastic variables. For its stochastic discretization a polynomial chaos (PC) is used to expand the coefficients into deterministic and stochastic parts. Then, from experimental data in combination with artificial data for elastomers the distribution of the force‐displacement curves are obtained. In the numerical example the PC‐based Stochastic Finite Element Method (SFEM) and the deterministic parameter identification are used for generation of the distribution of Ogden's material parameters. (© 2016 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Comparison of Financial Performance between Branded and Non-branded Hotel Companies using Composite Indicator

The Hospitality industry is one of the main sectors of tourism activity, being important to assess the performance of the hotel companies. The aim of the present paper is to study the financial performance of 570 companies operating hotel units in Portugal, in 2017, allowing for comparison among companies with similar stars rating and market orientation to explore the question of branded and non-branded affiliation. This issue is studied using a methodology based on Data Envelopment Analysis to assess the overall performance for each company. The hotel company performance is assessed through the aggregation of multiple financial indicators using the composite indicator derived from the DEA model. The empirical results show that the hotel branded companies have, on average, significantly, higher overall financial performance than hotel non-branded companies. Although, the best practices are observed in hotel branded and non-branded companies. This analysis can support the strategic decision process of the hotel companies in choosing to operate independently or selecting a brand affiliation.
The impact of inland ship emissions on air quality

Despite the large number of domestic inland river vessels in China, information on inland river vessel emissions is very limited, because limited legislation exists for emission control and there is no monitoring infrastructure. Taking the Yangtze River in the region of Nanjing as research area, we compiled a ship emission inventory based on real-time information received from Automatic Identification System (AIS) signals and ship-related basic data provided by China Classification 10 Society (CCS) database. The total estimated ship emissions in the Jiangsu section of the Yangtze River from September 2018 to August 2019 for NO x , SO 2 , PM 10 and PM 2.5 were 83.5, 41.8, 3.8 and 3.3 kton, respectively. These ship emissions were highest in the summer. From these estimates an inventory was constructed for ship emissions in the Yangtze River Delta (YRD) in Jiangsu. This ship emission inventory was compared with the Multi-resolution Emission Inventory for China (MEIC), the Shipping Emission Inventory Model (SEIM) and the satellite-derived emissions using the Daily Emissions Constrained by 15 Satellite Observations (DECSO) algorithm. The result shows a consistent spatial distribution with riverine cities having higher NO x pollution than non-riverine cities. With this comparison we analyzed the relative impact of ship emissions on densely populated regions along the river. Inland ship emissions of NO x and SO 2 are shown to contribute significantly, with each accounting for at least 40 %, to air pollution along the river.
Statistical challenges in high‐dimensional molecular and genetic epidemiology

Molecular and genetic association studies conducted in well‐characterized longitudinal cohorts offer a powerful approach to investigate factors influencing disease course or complex trait expression. As measurement technologies continue to develop and evolve, studies based on existing cohorts raise methodological challenges. Five such challenges are illustrated in two long‐term inter‐disciplinary collaborations. In one, molecular genetic prognostic factors in the natural history of node‐negative breast cancer are investigated using a combination of hypothesis‐testing and hypothesis‐generating molecular approaches. In the other, genome‐wide association methods are applied to identify genes for multiple traits in extended follow‐up data from participants of a therapeutic RCT in type 1 diabetes. The Canadian Journal of Statistics 46: 24–40; 2018 © 2017 Statistical Society of Canada
GRB minimum variability timescale with Insight-HXMT and Swift Implications for progenitor models, dissipation physics, and GRB classiﬁcations (cid:63)

Context. There has been signiﬁcant technological and scientiﬁc progress in our ability to detect, monitor, and model the physics of γ -ray bursts (GRBs) over the 50years since their ﬁrst discovery. However, the dissipation process thought to be responsible for their deﬁning prompt emission is still unknown. Recent e ﬀ orts have focused on investigating how the ultrarelativistic jet of the GRB propagates through the progenitor’s stellar envelope for di ﬀ erent initial composition shapes, jet structures, magnetisation, and, consequently, possible energy dissipation processes. Study of the temporal variability – in particular the shortest duration of an independent emission episode within a GRB – may provide a unique way to distinguish the imprint of the inner engine activity from geometry and propagation related e ﬀ ects. The advent of new high-energy detectors with exquisite time resolution now makes this possible. Aims. We aim to characterise the minimum variability timescale (MVT) deﬁned as the shortest duration of individual pulses that shape a light curve for a sample of GRBs in the keV–MeV energy range and test correlations with other key observables such as the peak luminosity, the Lorentz factor, and the jet opening angle. We compare these correlations with predictions from recent numerical simulations for a relativistic structured – possibly wobbling – jet and assess the value of temporal variability studies as probes of prompt-emission dissipation physics.
Analytic continuation of the 3F2 hypergeometric series

ABSTRACT In this article, we will use the binomial transformation to derive a series representation for the hypergeometric function that converges everywhere off the real interval . Additionally, we will find a stable recursion relation for the summand of this series, and we will establish the effectiveness of this series for numerical evaluation of .
Initiation to research in the context of initial teacher education: notes on an experience

The work approaches the initiation to research in the context of graduation. Its main objective is to present the “Adopt a Beginner Researcher Project – PAPI'', which arose from the need to help, in addition, UECE Pedagogy students in the elaboration of their first research project. A training action mobilized by the question: can initiated researchers favor the learning of undergraduates in the insertion in the world of research during initial training? The analysis, in methodological terms, assumes a qualitative feature, with data production mediated by an electronic questionnaire with the students participating in the experience in the 2022.1 semester. It is evident that the execution of the PAPI promotes a situation of mutual benefit: a positive experience for students, as they received advice and instructions about the production of their first research project; a formative experience for the mentor researchers, as it provided experience with the practice of academic guidance.
Modeling Solar Irradiance and Solar PV Power Output to Create a Resource Assessment Using Linear Multiple Multivariate Regression

AbstractThe increased use of solar photovoltaic (PV) cells as energy sources on electric grids has created the need for more accessible solar irradiance and power production estimates for use in power modeling software. In the present paper, a novel technique for creating solar irradiance estimates is introduced. A solar PV resource dataset created by combining numerical weather prediction assimilation model variables, satellite data, and high-resolution ground-based measurements is also presented. The dataset contains ≈152 000 geographic locations each with ≈26 000 hourly time steps. The solar irradiance outputs are global horizontal irradiance (GHI), direct normal irradiance (DNI), and diffuse horizontal irradiance (DIF). The technique is developed over the United States by training a linear multiple multivariate regression scheme at 10 locations. The technique is then applied to independent locations over the whole geographic domain. The irradiance estimates are input into a solar PV power modeling alg.
Faraday Synthesis of Unequally Spaced Data and Complex Deconvolution

—Faraday (AKA “Rotation Measure”) synthesis is a technique for extracting information about magnetized plasmas in front of linearly polarized sources. This memo explores this technique using simulated and observed wide-band MeerKAT data. Using a reference wavelength close to zero in calculating the Faraday allows using a narrower restoring beam in Faraday depth than a reference wavelength mid–band for MeerKAT–like data. The limitations of the coverage in λ 2 space, especially the negative portions, limit what can be recovered in the Faraday spectrum. Faraday components closely spaced in Faraday depth can interfere in ways that distort the derived deconvolved Faraday spectrum. Faraday components which are extended in Faraday depth are not well recovered and may appear as a pair of narrow features. Analysis of the MeerKAT L band observations of the galaxy cluster Abell 3395 exhibit large and rapidly variable Faraday components suggesting that the bulk of the Faraday screen is associated with AGN jets.