Miracle-dz/UniFAR-FTUs huggingface dataset:
Active Physical Interaction Control for Aerial Manipulator Based on External Wrench Estimation

This article investigates the active physical interaction problem of an aerial manipulator in terms of capability, reliability, and costs. Then, an active physical interaction control architecture is presented for the aerial manipulator to achieve both stable motion and interaction behaviors with external wrench estimation. Specifically, an external wrench estimator in absence of the acceleration and wrench measurements is designed to regulate the interaction point of the aerial manipulator with a minimal sensor condition. Next, a force tracking impedance control strategy with variable stiffness is presented to guarantee the contact stability and force tracking of the aerial manipulator with uncertain contact targets. Further, utilizing the knowledge of prescribed performance and terminal sliding mode surface, a pose controller is proposed to implement the dynamic response speed and accuracy control of the aerial manipulator, which provides a prerequisite for the realization of reliable physical interaction tasks. The stability of the proposed control architecture is analyzed through Lyapunov tools. Moreover, the feasibility and performance of the proposed control architecture are validated via simulations and real-world contact experiments.
Cosmic-ray positrons from mature gamma-ray pulsars

We consider a possible contribution of mature γ -ray pulsars (with ages of $\ge 10^5$ yrs) to cosmic ray positrons. Within the framework of the γ -ray pulsar outer gap model, ${\rm e}^{\pm}$ pairs in the pulsar magnetosphere are produced by the cascade of ${\rm e}^{\pm}$ pairs through synchrotron radiation of the return current from the outer gap. A good fraction of these cascade ${\rm e}^{\pm}$ pairs are reflected by the hard X-rays from the polar cap via resonant scattering and escape from the pulsar through the light cylinder. The escaped pairs are accelerated to relativistic energies in the pulsar wind driven by low-frequency electromagnetic waves. Using Monte Carlo simulations, we generate a sample of the mature γ -ray pulsars in our Galaxy and calculate the positron production rate from these pulsars. In a simple "leaky box" model, we calculate the ratio of cosmic-ray positrons to total electrons. Our result indicates that the pulsar contribution to the cosmic ray positrons peaks at about 60 GeV and the observed ${\rm e}^+/({\rm e}^-+{\rm e}^+)$ ratio can be explained in this model.
Mission as ‘being with’ in the context of the COVID-19 pandemic in South Africa

This research investigated the impact measures (such as lockdowns) used to combat the spread of the coronavirus disease of 2019 (COVID-19) have on the church's mission. When people face travel and assembly restrictions, the church as a community of witnesses testifying and participating in Christ's work risks is being neutralised, and its presence weakened. What then does mission as ‘ being with ' look like in these situations? Is faithful presence something one can turn on and off at will depending on the situation? If faithful presence was no more, what then was the impact of such absence on the church's mission? These questions underscore the relevance of this research which sought to ascertain the impact the COVID-19 pandemic lockdown had on the church's mission. The crucial area this research sought to explore are the lessons from the COVID-19 lockdown that will help the church prepare for future pandemics which scientists say are inevitable. The research made use of a qualitative interview method to discover the meaning of ‘ being with' in the context of the COVID-19 lockdown. The results revealed six attributes of a missional church. Based on these attributes, the research recommends a seven-step process to prepare the church for possible future pandemics. Contribution: This research has provided the church with an opportunity to shift from being ‘inward-looking' to a church that is community focused, a church that prepares, trains and equips its adherents for the work of ministry in their own communities such that the work of ministry continues with or without gatherings.
The extrapolated LMS adaptive filtering algorithms

Two novel adaptive filtering algorithms are proposed. The algorithms greatly reduce the number of adaptation steps of the LMS algorithm by extrapolating the adaptive filtering coefficients. The extrapolation is done through the time constant and optimal coefficient estimations of the coefficient adaptation process. Simulation results for the system identification and correlation canceller loop show significant reduction of the adaptation steps. The algorithms can be applied to general orthogonal adaptive filters and least-square error optimization problems.
Companion Vector-Borne Pathogens and Associated Risk Factors in Apparently Healthy Pet Animals (Dogs and Cats) in Khukhot City Municipality, Pathum Thani Province, Thailand

Pet animals (dogs and cats) can be infected with several companion vector-borne pathogens (CVBPs). Morbidity and mortality have been reported in pet animals due to CVBP infections. Pet animals living in close proximity to humans are able to transmit zoonotic pathogens. This study used molecular techniques to investigate the prevalence of CVBPs in apparently healthy pet animals (dogs and cats) from Khukhot City Municipality, Pathum Thani province, Thailand. In total, 210 blood samples were randomly collected from 95 dogs and 115 cats for the detection of seven companion vector-borne pathogens (Anaplasma, Babesia, Bartonella, Ehrlichia, Hepatozoon, Mycoplasma, and Rickettsia) using polymerase chain reaction. The results showed that 10.5% (22/210) of apparently healthy pet animals were infected with at least one pathogen, comprising 6 dogs (6.3% of all dogs tested) and 16 cats (13.9% of all cats tested). Ehrlichia (6.3%) was present only in dogs; furthermore, 1.1% of the dogs were positive for Anaplasma. There was one dog case co-infected with two pathogens (1.1%). In cats, Mycoplasma (9.6%) was the predominant CVBP, followed by Rickettsia (4.4%). The DNA sequences of all positive animals were 97–99% homologous to those found in the GenBank™ database for all CVBPs identified, namely Ehrlichia canis, Anaplasma platys, Rickettsia felis, Mycoplasma haemofelis, and Candidatus Mycoplasma haemominutum. Additionally, the risk of infection with CVBPs in pets was significantly associated with age, with young dogs more likely to be infected with CVBPs than adult dogs (OR 8.5, 95% CI 1.4–50.1, p = 0.006), while adult cats were more likely to be infected with CVBPs than young cats (OR 3.8, 95% CI 1.0–14.0, p = 0.038). The detection of CVBPs demonstrated the potential risk of infection that may occur in apparently healthy pet animals in Pathum Thani province. These results confirmed that apparently healthy pet animals may still be at risk of vector-borne infections and could maintain the infection cycle in pet populations. Furthermore, sampling a greater number of apparently healthy pet animals may disclose predictors of CVBP positivity in domesticated animals in this area.
Radiative Processes in Cool Star Chromospheres

Observations made with the International Ultraviolet Explorer (IUE) satellite between 1200 A and 3000 A have shown that the spectra of giant and supergiant stars later than about K O are dominated by emission from neutral atoms and singly charged ions. This is in contrast to the spectra of G-type and main sequence stars which show species typical of the solar transition region. The cool star spectra show many examples of photo-excitation, line-leaking and fluorescent processes, some of which are discussed here. There is evidence that the H Ly α and H Ly β lines play an important role in the production of emission from O I, S I and Fe II. Some lines which remain without satisfactory explanations in both the stellar and solar spectra are discussed.
Spatial distribution analysis of critical temperature in epitaxial Y-Ba-Cu-O film using variable temperature scanning laser microscopy

We have investigated the spatial distribution of superconducting transition in an epitaxial YBa/sub 2/Cu/sub 3/O/sub 7/ film using variable temperature scanning laser microscope (VTSLM). VTSLM creates an image of the ac voltage response, /spl delta/V(x,y), due to an ac modulated laser beam, which is proportional to dRdT(x,y). In the resistive transition region, there is a strong correlation between the VTSLM images and the resistance of the sample. When the sample is making a poor thermal contact to the heat bath, the large /spl delta/V(x,y) region shifts toward the ends of the bridge while the sample resistance decreases. This result is due to the variation of surface temperature along the sample created by the heating at the contact resistance and/or the poor thermal contact between the sample and the heat bath. However, even after improving thermal contact, we still observe the distribution of superconducting transition. Since the local superconducting transition occurs within 1 K, we conclude that any samples with superconducting transition width larger than 1 K have local nonuniformity.
Familial Mediterranean Fever in Spain: Time Trend and Spatial Distribution of the Hospitalizations

Familial Mediterranean Fever (FMF) is a rare, hereditary, auto-inflammatory disease. The aims of this study were to explore the time trend and geographical distribution of hospitalizations in Spain from 2008 to 2015. We identified hospitalizations of FMF from the Spanish Minimum Basic Data Set at hospital discharge, using ICD-9-CM code 277.31. Age-specific and age-adjusted hospitalization rates were calculated. The time trend and the average percentage change were analyzed using Joinpoint regression. Standardized morbidity ratios were calculated and mapped by province. A total of 960 FMF-related hospitalizations (52% men) were identified across the period 2008–2015, with an increase in hospitalizations of 4.9% per year being detected (p < 0.05). The risk of hospitalization was higher than expected for the national total (SMR > 1) in 13 provinces (5 in the Mediterranean area), and lower (SMR < 1) in 14 provinces (3 in the Mediterranean area). There was an increase in hospitalizations of patients with FMF in Spain throughout the study period, with a risk of hospitalization that was higher, though not exclusively so, in provinces along the Mediterranean coast. These findings contribute to the visibility of FMF and provide useful information for health planning. Further research should take into account new population-based information, in order to continue monitoring this disease.
Identification of SNP loci and candidate genes genetically controlling norisoprenoids in grape berry based on genome-wide association study

Obtaining new grapevine varieties with unique aromas has been a long-standing goal of breeders. Norisoprenoids are of particular interest to wine producers and researchers, as these compounds are responsible for the important varietal aromas in wine, characterized by a complex floral and fruity smell, and are likely present in all grape varieties. However, the single-nucleotide polymorphism (SNP) loci and candidate genes genetically controlling the norisoprenoid content in grape berry remain unknown. To this end, in this study, we investigated 13 norisoprenoid traits across two years in an F1 population consisting of 149 individuals from a hybrid of Vitis vinifera L. cv. Muscat Alexandria and V. vinifera L. cv. Christmas Rose. Based on 568,953 SNP markers, genome-wide association analysis revealed that 27 candidate SNP loci belonging to 18 genes were significantly associated with the concentrations of norisoprenoid components in grape berry. Among them, 13 SNPs were confirmed in a grapevine germplasm population comprising 97 varieties, including two non-synonymous mutations SNPs within the VvDXS1 and VvGGPPS genes, respectively in the isoprenoid metabolic pathway. Genotype analysis showed that the grapevine individuals with the heterozygous genotype C/T at chr5:2987350 of VvGGPPS accumulated higher average levels of 6-methyl-5-hepten-2-one and β-cyclocitral than those with the homozygous genotype C/C. Furthermore, VvGGPPS was highly expressed in individuals with high norisoprenoids concentrations. Transient overexpression of VvGGPPS in the leaves of Vitis quinquangularis and tobacco resulted in an increase in norisoprenoid concentrations. These findings indicate the importance of VvGGPPS in the genetic control of norisoprenoids in grape berries, serving as a potential molecular breeding target for aroma.
Impact of Managerial Entrenchment on Firm Performance

This research attempts to analyze the impact of managerial entrenchment on firm performance in the context of KSE-100 index companies in Pakistan. The given study engages the CEO share as the measure of managerial entrenchment and investigate its impact on financial performance of companies. In pertinent to this, regression analysis has been utilized by employing the top performing corporations listed on KSE-100 index. For measurement of firm performance, this study employs the two variables used to quantify firm performance as “return on assets (ROA)” and “Tobin's Q”. This study comprises 318 observations, from 53 non-financial companies of Pakistan Stock Exchange (PSX), over 6 years period (2015-2020) from annual reports. The results of this study indicate that there is a significant negative relationship between the managerial entrenchment measured through CEO share and financial performance measured through ROA and Tobin’s Q. The study has some limitations. The future researchers can add other parameters of managerial entrenchment such as board independence, board compensation, tenure and management duality to get more insights on this association. The research findings are giving implications for managers, investors and shareholders. Managers may adopt techniques that allow them to strengthen their position thus gaining investors’ confidence. This research extends the literature by comprehensively employing the impact of managerial entrenchment on financial performance of companies in KSE-100 index companies that was predominately neglected by the previous researchers in context of Pakistan
Developing holey fibres for evanescent field devices

The overlap of the optical mode in a holey fibre with the air holes is calculated for the first time. This is achieved using a vector modal decomposition approach. It is shown that a significant fraction of the modal power can be made to overlap with the holes, which suggests that these unusual fibres may be useful as evanescent field devices.
Local Linear Quantile Regression

Abstract In this article we study nonparametric regression quantile estimation by kernel weighted local linear fitting. Two such estimators are considered. One is based on localizing the characterization of a regression quantile as the minimizer of E{pp (Y — a)|X = x}, where ρp is the appropriate “check” function. The other follows by inverting a local linear conditional distribution estimator and involves two smoothing parameters, rather than one. Our aim is to present fully operational versions of both approaches and to show that each works quite well; although either might be used in practice, we have a particular preference for the second. Our automatic smoothing parameter selection method is novel; the main regression quantile smoothing parameters are chosen by rule-of-thumb adaptations of state-of-the-art methods for smoothing parameter selection for regression mean estimation. The techniques are illustrated by application to two datasets and compared in simulations.
Approaches to Forecasting Damage by Invasive Forest Insects and Pathogens: A Cross-Assessment

Nonnative insects and pathogens pose major threats to forest ecosystems worldwide, greatly diminishing the ecosystem services trees provide. Given the high global diversity of arthropod and microbial species, their often unknown biological features or even identities, and their ease of accidental transport, there is an urgent need to better forecast the most likely species to cause damage. Several risk assessment approaches have been proposed or implemented to guide preventative measures. However, the underlying assumptions of each approach have rarely been explicitly identified or critically evaluated. We propose that evaluating the implicit assumptions, optimal usages, and advantages and limitations of each approach could help improve their combined utility. We consider four general categories: using prior pest status in native and previously invaded regions; evaluating statistical patterns of traits and gene sequences associated with a high impact; sentinel and other plantings to expose trees to insects and pathogens in native, nonnative, or experimental settings; and laboratory assays using detached plant parts or seedlings under controlled conditions. We evaluate how and under what conditions the assumptions of each approach are best met and propose methods for integrating multiple approaches to improve our forecasting ability and prevent losses from invasive pests.
Digital watermark method based on estimating harmonics frequency

In this paper, a new digital watermarking algorithm is presented. In this algorithm, the watermark embedded in image is constructed by several harmonics with known frequencies. When detected, the harmonics frequencies of the watermark extracted from the watermarked image will be estimated and compared with the original watermark. If the estimated and the original frequencies are equal within the permitted error limits, we say it is a successful detection. Because the harmonic estimating algorithm used in the paper can deal with complicated additive noise, the watermark algorithm presented in the paper is rather robust. Simulation results are provided to support the algorithm.
Evaluation of the impact of gamification on students’ performance and engagement in manufacturing engineering courses

In engineering courses with a large number of students, fail and dropout rates are usually high even in courses that can be expected to be interesting to the students. Gamification tools have arisen as an interesting way to motivate the students for a real continuous assessment, increasing the student’s attendance and performance. In this paper, a gamification approach based on a Kahoot tool, Moodle activities, and commemorative badges is proposed within a manufacturing course. The designed activities let the students compete among themselves to get the maximum number of points, which will be converted into extra grades that are added to the final exam grade. The gamification experience has been proven to be highly positive according to students’ and instructors’ perceptions, and the average increase of pass rate and course attendance with respect to previous years have increased from 22% to 34% and from 38% to 66%, respectively.
Dynamics of sheared inelastic dumbbells

We study the dynamical properties of the homogeneous shear flow of inelastic dumbbells in two dimensions as a first step towards examining the effect of shape on the properties of flowing granular materials. The dumbbells are modelled as smooth fused disks characterized by the ratio of the distance between centres (L) and the disk diameter (D), with an aspect ratio (L/D) varying between 0 and 1 in our simulations. Area fractions studied are in the range 0.1–0.7, while coefficients of normal restitution (en) from 0.99 to 0.7 are considered. The simulations use a modified form of the event-driven methodology for circular disks. The average orientation is characterized by an order parameter S, which varies between 0 (for a perfectly disordered fluid) and 1 (for a fluid with the axes of all dumbbells in the same direction). We investigate power-law fits of S as a function of (L/D) and (1−en2). There is a gradual increase in ordering as the area fraction is increased, as the aspect ratio is increased or as the coefficient of restitution is decreased. The order parameter has a maximum value of about 0.5 for the highest area fraction and lowest coefficient of restitution considered here. The mean energy of the velocity fluctuations in the flow direction is higher than that in the gradient direction and the rotational energy, though the difference decreases as the area fraction increases, due to the efficient collisional transfer of energy between the three directions. The distributions of the translational and rotational velocities are Gaussian to a very good approximation. The pressure is found to be remarkably independent of the coefficient of restitution. The pressure and dissipation rate show relatively little variation when scaled by the collision frequency for all the area fractions studied here, indicating that the collision frequency determines the momentum transport and energy dissipation, even at the lowest area fractions studied here. The mean angular velocity of the particles is equal to half the vorticity at low area fractions, but the magnitude systematically decreases to less than half the vorticity as the area fraction is increased, even though the stress tensor is symmetric.
The RMT method for many-electron atomic systems in intense short-pulse laser light

We describe a new ab initio method for solving the time-dependent Schrödinger equation for multi-electron atomic systems exposed to intense short-pulse laser light. We call the method the R-matrix with time-dependence (RMT) method. Our starting point is a finite-difference numerical integrator (HELIUM), which has proved successful at describing few-electron atoms and atomic ions in strong laser fields with high accuracy. By exploiting the R-matrix division-of-space concept, we bring together a numerical method most appropriate to the multi-electron finite inner region (R-matrix basis set) and a different numerical method most appropriate to the one-electron outer region (finite difference). In order to exploit massively parallel supercomputers efficiently, we time-propagate the wavefunction in both regions by employing Arnoldi methods, originally developed for HELIUM.