Miracle-dz/UniFAR-FTUs huggingface dataset:
Linear Supervised Transfer Learning for Generalized Matrix LVQ

The utility of machine learning models in everyday applications critically depends on their robustness with respect to systematic changes in the input data. However, many machine learning models trained under lab conditions do break down if they are confronted with such systematic changes. Transfer learning addresses this issue by modelling changes in the input as transfer functions, which can be used to map the data to a space where the learned machine learning model is applicable again. In this contribution we introduce linear supervised transfer learning as a novel transfer learning scheme and propose a realization based on generalized matrix learning vector quantization. We evaluate our approach in a practical application from the medical domain, namely classifying the intended arm motion from a muscle signal, which can be used by amputees to control a bionic prosthesis and regain hand function after limb loss.
A Sufficient Condition for Exponential Dichotomy of Parabolic Evolution Equations

assuming that A(t), t ∈ R, generates an analytic semigroup (e)τ≥0 and A(·)−1 satisfies a certain Hölder condition (see (P) below). Moreover, each semigroup (e)τ≥0 is supposed to have exponential dichotomy and the Hölder constant of A(·)−1 must be sufficiently small. Already simple matrix examples, [6, p.3], [15, Ex.3. 4], show that one cannot omit this smallness condition. Similar sufficient conditions for exponential dichotomy are known for matrices A(t), [6], bounded operators A(t), [4], and delay equations, [12]. In [15] we have shown the main Theorem 5 of the present paper for the special case of time independent domains D(A(t)) ≡ D(A(0)). This seems to be the first result of this kind for parabolic evolution equations; but the hypothesis of constant domains is rather restrictive because it excludes, for instance, Neumann type boundary conditions in the context of parabolic partial differential equations, see [17, §4]. The results in [4] and [15] are further improved by Proposition 6 which determines the rank of the splitting projections for (CP). Our approach is based on a characterization of the exponential dichotomy of (CP) by means of the associated evolution semigroup defined in (10), cf. [5] or [7, §VI.9]. In order to prove our main result in the third section we use ideas from [4] and [15], but we supplement them by the theory of interand extrapolation spaces as studied in, e.g., [3], [7], [13]. The necessary tools are introduced in the next section.
Unit Root Testing on Buffered Autoregressive Model

A buffered autoregression extends the classical threshold autoregression by allowing a buffer region for regime changes. In this study, we examine asymptotic statistical inferences for the two-regime buffered autoregressive (BAR) model, with autoregressive unit roots. We propose a Sup-LR test for the nonlinear buffer effect in the possible presence of unit roots, and a class of unit root tests to identify the number of nonstationary regimes in the BAR model. The wild bootstrap method is suggested to approximate the critical values of the two tests. Simulation results show that the proposed unit root test outperforms the conventional augmented Dickey–Fuller test, and that the two wild bootstrap tests are robust to unknown heteroscedasticity. Two macroeconomic data examples, based on U.S. unemployment rates and real exchange rates, respectively, are provided to illustrate the methods.
A singular vorticity wave packet within a rapidly rotating vortex: spiralling versus oscillating motions

This paper considers a free vorticity wave packet propagating within a rapidly rotating vortex in the quasi-steady regime, a long time after the wave packet strongly and unsteadily interacted with the vortex. We study a singular, nonlinear, helical and asymmetric shear mode inside a linearly stable, columnar and axisymmetric vortex on the $f$ -plane. The amplitude-modulated mode enters resonance with the vortex at a certain radius $r_{c}$ , where the phase angular speed is equal to the rotation frequency. The singularity in the modal equation at $r_{c}$ strongly modifies the flow in the three-dimensional helical critical layer, the region around $r_{c}$ where the wave/vortex interaction occurs. This interaction generates a vertically sheared three-dimensional mean flow of higher amplitude than the wave packet. The chosen envelope regime assumes the formation of a mean radial velocity of the same order as the wave packet amplitude, leading to the streamlines exhibiting a spiral motion in the neighbourhood of the critical layer. Radar images frequently show such spiral bands in tropical cyclones or tornadoes. Through matched asymptotic expansions, we find an analytical solution of the leading-order equations inside the critical layer. The generalized Batchelor integral condition applied to the quasi-steady, three-dimensional motion inside the separatrices yields a leading-order, non-uniform three-dimensional vorticity. The critical-layer pattern, strongly deformed by the mean radial velocity, loses its symmetries with respect to the azimuthal and radial directions, which makes the leading-order mean radial wave fluxes non-zero. Finally, a stronger wave/vortex interaction occurs with respect to previous studies where a steady neutral vortical mode or an envelope of larger extent was involved.
Using Exploratory Bifactor Analysis to Understand the Latent Structure of Multidimensional Psychological Measures: An Example Featuring the WISC-V

Exploratory bifactor analysis (EBFA) represents a methodological advancement for implementing a bifactor model in exploratory factor analysis (EFA). However, little is known about how to properly employ the procedure. The current rotation criteria available for EBFA make it more likely to “get stuck” in local minima, contributing to possible group factor collapse, than more traditional EFA rotations. Thus, getting a proper solution is a more complex and involved process than typical EFA and may require a sensitivity analysis. This article examines EBFA through a sensitivity analysis and subsequent simulation of parameters thought to contribute to group factor collapse. Results support the use of sensitivity analysis, as the problematic variable was shown to greatly increase the likelihood of factor collapse. The hypothesis that estimation start values contribute to factor collapse was not supported. Accompanying R syntax for all analyses are provided to facilitate reproducibility.
Korean Students' Intentions to Use Mobile-Assisted Language Learning: Applying the Technology Acceptance Model

The purpose of this study was to examine how Korean students accept and use mobile-assisted language learning (MALL) and investigate related factors that potentially affect MALL usage. The participants were 244 undergraduate students who were surveyed with a questionnaire. The research model, which included students’ self-efficacy, content reliability, interactivity, perceived enjoyment, perceived usefulness, perceived ease of use, attitude, and behavioral intention to use MALL, was developed based on the technology acceptance model (TAM). The structural equation modeling (SEM) technique was employed in order to analyze the overall results of modified TAM and the research model. The results indicated that TAM was a good theoretical tool to understand students’ acceptance of MALL. In addition, all constructs, with the exception of self-efficacy and interactivity, had significant effects on students’ acceptance possibilities of MALL. Limitations and suggestions for the further study are also presented.
The Complexity Entropy Analysis of a Supply Chain System Considering Recovery Rate and Channel Service

In this paper, we study a dual-channel closed-loop supply chain in which a manufacturer considers the market waste products recovery and remanufacture, and a retailer considers provide services to customers. We build a Stackelberg game model and a centralized game model in a static and dynamic state, respectively, and analyze the two dynamic models by mathematical analysis and explore the stability and entropy of the two models using bifurcation, the basin of attraction, chaotic attractors, and so on. The influences of service level and profit distribution rate on the system’s profit are discussed. The theoretical results show that higher price adjustment speed will lead to the system lose stability with a larger entropy value. In the Stackelberg game model, the stability of the system increases as the service value and the recovery rate increases; in the centralized model, the stability of the system decreases with the increase of the service value and increases with the recovery rate increases. When the Stackelberg game model is in a stable state, the manufacturer’s profit increases first and then decreases, and the retailer’s profit first decreases and then increases as the service value of the retailer increases. The research will serve as good guidance for both the manufacturer and retailer in dual-channel closed-loop supply chains to improve decision making.
Spontaneous Edge Current in Chiral Superconductors with High Chirality

We study the spontaneous edge current of chiral superconductors with high chirality both in the absence and presence of Meissner screening. We compute the edge current from a self-consistent solution to a set of coupled equations: quasiclassical Eilenberger equation, superconducting gap equation, and Maxwell equation. We find that the spatial dependent chiral edge current is largely suppressed and has more nodes for higher chirality pairings. In the absence of Meissner screening, the integrated current at T = 0 is zero for all higher chirality pairings; while it is substantial for chiral p-wave. This conclusion is consistent with previous studies. In contrast, at finite T , the integrated current is non-zero even for higher chiral pairings. It turns out that the spatial varying order parameter is crucial to understand this finite T behavior of the edge current. When Meissner screening is included, the magnitude of the edge currents is reduced for all chiral pairings; however, the reduction is much weaker in higher chirality cases. We conclude that the Meissner effect is not that important for higher chiral pairings. We also consider the effect of the rough surface on the edge current. The edge current of even chiral pairings is inverted by the strong surface roughness; however, that of the odd chiral pairings is not. The sub-dominant order parameters, induced by the surface, are the key to understanding this current inversion. iii
Using Event Semantics for Toponym Disambiguation

This chapter discusses a method for improving the disambiguation of location names using limited event semantics. Location names are often ambiguous, as the same name may refer to locations in different states, countries, or continents. Ambiguous location names, also known as toponyms, need to be disambiguated (or grounded) when resolving many spatial relations expressed in textual documents. Previous methods for disambiguating toponyms have utilized simple heuristics, statistical ranking, and ontological methods in order to resolve a location reference. However, since toponyms are used in documents that refer to events, semantic knowledge characterizing events can be used to ground location names. We propose an ontology-based method with a technique that considers the participants in events such as people, organizations, and other locations. Event semantics are integrated into an ontology that is used to distinguish geographical names through a probabilistic approach based on logistic regression. Our experimental results on the SpatialML corpus (Mani et al., 2008) indicate that using event structures improves the quality of disambiguated toponyms.
Multiplicity Dependence of Strangeness and Charged Particle Production in Proton--Proton Collisions

In this contribution, the production rates and the transverse momentum distributions of strange hadrons are reported as a function of charged particle multiplicity. In this analysis, the data collected in proton-proton collisions at $\sqrt{s}$ = 13 TeV with the ALICE detector at the LHC are used. It is found that the production rate of $K_{S}^{0}$, $\Lambda$, $\Xi^{\pm}$, and $\Omega$ increases with multiplicity faster than that for charged particles. The higher the strangeness content of the hadron, the more pronounced is the increase. Moreover, the energy and multiplicity dependence of charged particle production in pp collisions are presented and the results are compared to predictions from Monte Carlo (MC) event generators. It turns out that the average multiplicity density increases steeply with center-of-mass energy for high multiplicity classes.
Analysis of a new spatial interpolation weighting method to estimate missing data applied to rainfall records

In the present work, two new generalized weighted methods of imputation of missing data are developed and tested using a daily rainfall series. The proposed methodology allows to fully rebuild the time series while preserving its statistical properties. Rainfall records in the state of Tabasco, Mexico, during the period 1980-2012 were used to test and evaluate the proposed methodology. The imputation of missing data in a given weather station is performed by using daily data from neighboring stations with a similar rainfall behavior. The choice of optimal parameters for the proposed formulae is based on minimizing the mean absolute error (MAE) via an evolutionary strategy (CMA-ES). The K -means method was used with the Euclidean distance in order to select the adequate neighboring weather stations. Five different methods were applied to estimate the optimal number of clusters: the elbow method, gap statistics, TraceW, Hartigan and Krzanowski-Lai indices. In addition, the structural stability of the chosen clusters was evaluated in order to demonstrate that these represent the correct data structure and are not the result of an artificial internal procedure of the grouping algorithm. Results from two different statistical tests, Friedman and Nemenyi post hoc, showed that our two new methods produce significantly and statistically better estimation when compared to existing methods in the literature.
Reading Versus Doing: Methods of Teaching Problem-Solving in Introductory Statistics

Abstract Practice problems and worked examples are both well-established teaching techniques. Research in math and physics suggests that having students study worked examples during their first contact with new material, instead of solving practice problems, can be beneficial to their subsequent performance, possibly due to the reduced cognitive load required to study examples compared to generating solutions. However, there is minimal research directly comparing these teaching methods in introductory statistics. In this study, we chose six pairs of introductory statistics topics of approximately equal difficulty from throughout the semester. After an initial mini-lecture, one topic from each pair was taught using practice problems; the other was taught by having students read worked examples. Using Bayesian and frequentist analyses, we find that student performance is better after reading worked examples. This may be due to worked examples slowing the process of forgetting. Surprisingly, there is also strong evidence from in-class surveys that students experience greater frustration when reading worked examples. This could indicate that frustration is not an effective proxy for cognitive load. Alternatively, it could indicate that classroom supports during in-class problem-solving were effective in reducing the cognitive load of practice problems below that of interpreting written statistical explanations.
An Improved Single-Channel Polar Region Ice Surface Temperature Retrieval Algorithm Using Landsat-8 Data

Ice surface temperature (IST) is a key parameter for the study of polar ice sheets and ice shelves. In this study, an improved single-channel (ISC) algorithm based on the radiative transfer equation is proposed for IST retrieval from Landsat-8 band 10 data. The main steps in the proposed ISC algorithm include: 1) simulation of atmospheric radiative parameters by regression against the atmospheric water vapor content and the effective mean atmospheric temperature; 2) calculation of IST using Planck’s equation, instead of using Taylor’s approximation; and 3) implementation of an iterative scheme for IST calculation. The errors from using Taylor’s approximation and the atmospheric radiative parameter simulation were quantitatively estimated. A sensitivity analysis of ISC to possible errors in atmospheric water vapor content, brightness temperature, and satellite observations was also conducted. The results of the sensitivity analysis showed that the proposed algorithm is robust to the atmospheric water vapor content, but is sensitive to the calibration precision of the thermal infrared sensor. Verification using a simulated approach showed better IST variability from ISC than the original SC algorithm [the root-mean-square errors (RMSEs) were 0.3252 and 0.7176 K, respectively]. When compared with near-surface air temperatures from 68 automatic weather stations data in Greenland and 25 data in the Antarctic, the bias and RMSE from the ISC algorithm were again better than those from the SC algorithm. The IST from Moderate Resolution Imaging Spectroradiometer (MODIS) was found to be underestimated with respect to the results of both the SC and ISC algorithms. Maps of the spatial distributions of IST derived from samples of Landsat-8 images are presented. The rationale of each step in the proposed ISC algorithm is also presented so that this can provide further support to the authenticity of the results.
Turbulent temperature fluctuations in a closed Rayleigh–Bénard convection cell

We report a systematic study of spatial variations of the probability density function (PDF) $P(\unicode[STIX]{x1D6FF}T)$ for temperature fluctuations $\unicode[STIX]{x1D6FF}T$ in turbulent Rayleigh–Bénard convection along the central axis of two different convection cells. One of the convection cells is a vertical thin disk and the other is an upright cylinder of aspect ratio unity. By changing the distance $z$ away from the bottom conducting plate, we find the functional form of the measured $P(\unicode[STIX]{x1D6FF}T)$ in both cells evolves continuously with distinct changes in four different flow regions, namely, the thermal boundary layer, mixing zone, turbulent bulk region and cell centre. By assuming temperature fluctuations in different flow regions are all made from two independent sources, namely, a homogeneous (turbulent) background which obeys Gaussian statistics and non-uniform thermal plumes with an exponential distribution, we obtain the analytic expressions of $P(\unicode[STIX]{x1D6FF}T)$ in four different flow regions, which are found to be in good agreement with the experimental results. Our work thus provides a unique theoretical framework with a common set of parameters to quantitatively describe the effect of turbulent background, thermal plumes and their spatio-temporal intermittency on the temperature PDF $P(\unicode[STIX]{x1D6FF}T)$ .
A two-way street: building the recruitment narrative in LIS programs

Purpose This paper aims to explore the attractiveness of Library and Information Science (LIS) careers to students and alumni and examine their decision-making process and perceptions of the field with an eye on discerning the best ways to build and develop the recruitment narrative. Design/methodology/approach The authors reached out to 57 LIS graduate programs in Canada and the USA accredited by the American Library Association through a Web-based survey; the questions presented a combination of multiple-choice, short-answer and open-ended questions and generated a wealth of quantitative and qualitative data. Findings The online survey has disclosed that students may not have an in-depth understanding of current trends, the diversity of LIS professions and the wider applications of their education. A significant disconnect exists in how the goals of LIS education are seen by certain groups of practitioners, students and faculty members. Originality/value Creating a program narrative for the purposes of recruitment and retention, departments should not only capitalize on the reach of the internet and the experiences of successful practitioners. They should also ensure that faculty know their students’ personal backgrounds, that students empathize with demands of contemporary academia and that a promotional message connects pragmatic educational goals to broader social applications. By exposing and embracing the complexity of LIS education and practice, the paper chooses a discursive path to start a conversation among major stakeholders.
Variations pattern in selected mechanical properties of stem and branch woods of Khaya grandifoliola (Welw.) C. DC.

This study was conducted to evaluate variations pattern in selected mechanical properties of stem and branch woods of Khaya grandifoliola with a view to identifying its utilization potentials. Wood samples were collected from Khaya grandifoliola in the Department of Forest Resources Management, University of Ibadan, Nigeria. Khaya grandifoliola tree was felled and sectioned into main boles, primary and secondary branch woods. Fifty centimetres (50cm) length bolts were obtained from the base, middle and top of the stem, two (2) primary branch woods and four (4) secondary branch woods. Bolts from the main bole were partitioned into innerwood, middlewood and outerwood sections of the radial and longitudinal positions at base 10, middle 50 and top 90% of the tree height. Planks were also obtained from the central portion of the bolts of primary and secondary branch and were further converted into test samples. Data obtained were analysed using descriptive statistics and ANOVA. The mean value of impact bending strength of stem wood was 1970.62 J/m 2 . Primary and secondary branch woods had mean values of 1778 J/m 2 and 1812.93 J/m 2 , respectively. The mean value of maximum compressive strength parallel to the grain of stem wood was 43.13 N/mm 2 . Primary branch wood had mean value of 43.41N/mm 2 , while the secondary branch wood had mean value of 44.31N/mm 2 . The mean value of Modulus of Rupture of stem wood was 65.46 N/mm 2 . Primary branch woods were 66.57N/mm while the secondary branch woods were 62.88 N/mm 2 . The mean value of Modulus of Elasticity of stem wood was 11468.29 N/mm 2 . Secondary and Primary branch woods had mean values of 13599.76N/mm 2 and 12069.82N/mm 2 respectively. The study revealed that wood from tree branches had similar characteristics with stem wood; and would perform same functions in wooden structures. Keywords: Impact bending strength, maximum compressive strength, modulus of elasticity, modulus of rupture, utilization