Miracle-dz/UniFAR-FTUs huggingface dataset:
M-estimation of multivariate linear regression parameters under a convex discrepancy function

There is vast literature on M-estimation of linear regression parameters. Most of the papers deal with special cases by choosing particular discrepancy functions to be minimized or particular estimating equations. A few discuss general results, but prove results under heavy assumptions which seem to exclude important special cases. In this paper, a general theory of M-estimation is developed using a convex discrepancy function under what appear to be a necessary set of assumptions to develop a satisfactory asymptotic theory. Detailed proofs are given for establishing the asymptotic normality of the distribution of M-estimates and the results are applied to several particular cases. Appropriate criteria are developed for tests of hypotheses concerning regression parameters. The problem is discussed in the multivariate situation which includes the univariate case.
The Alaska Blocking Index, version 2: Analysis and covariability with statewide and large‐scale climate from 1948 to 2020

Monitoring and quantifying high‐latitude atmospheric circulation variability and trends are important towards understanding the anatomy of extreme events and constraining their probabilities under continued Arctic change. The greater Alaska region stands out as one region of enhanced warming and environmental changes over the Arctic amplification era, which has shown proclivity to extreme events and speaks to the need to consistently monitor overlying atmospheric variability. In this paper, we describe the creation and analysis of an updated, daily mid‐tropospheric Alaska Blocking Index (ABI) time series from 1948 to 2020. Sensitivity testing and index modifications from the initial dataset are discussed, and the new ABI is evaluated over the full period and subperiods. Additionally, we assess the role of the ABI as a regional climate indicator by analysing its variability against surface air temperature and precipitation from 13 climate divisions across Alaska as well as broader‐scale hemispheric temperatures. Months of the highest ABI means mainly transpired in the most recent climatological period, 1991–2020, and most notably during the spring and autumn transition seasons, reflecting the nonstationary nature of the jet stream magnitude through time atop Alaska. ABI trends are positive across all months, seasons, and annually only in the 1991–2020 period. Contemporaneous ABI values are strongly and positively correlated with air temperature across all Alaskan climate divisions during the warm season, but negatively correlated with winter temperatures over southeastern Alaska. Meanwhile, the ABI is significantly anticorrelated with summer precipitation over Interior and southern Alaska, but only over southeastern Alaska in other seasons. The ABI is statistically differentiated from the primary modes of atmospheric variability as shown by its generally weak correlations with the Arctic Dipole and the Arctic Oscillation (r ≤ 0.40).
Electron energy spectra, fluxes, and day-night asymmetries of 8B solar neutrinos from measurements with NaCl dissolved in the heavy-water detector at the Sudbury Neutrino Observatory

Results are reported from the complete salt phase of the Sudbury Neutrino Observatory experiment in which NaCl was dissolved in the {sup 2}H{sub 2}O (''D{sub 2}O'') target. The addition of salt enhanced the signal from neutron capture as compared to the pure D{sub 2}O detector. By making a statistical separation of charged-current events from other types based on event-isotropy criteria, the effective electron recoil energy spectrum has been extracted. In units of 10{sup 6}cm{sup -2}s{sup -1}, the total flux of active-flavor neutrinos from {sup 8}B decay in the Sun is found to be 4.94{sub -0.21}{sup +0.21}(stat){sub -0.34}{sup +0.38}(syst) and the integral flux of electron neutrinos for an undistorted {sup 8}B spectrum is 1.68{sub -0.06}{sup +0.06}(stat){sub -0.09}{sup +0.08}(syst); the signal from ({nu}{sub x},e) elastic scattering is equivalent to an electron-neutrino flux of 2.35{sub -0.22}{sup +0.22}(stat){sub -0.15}{sup +0.15}(syst). These results are consistent with those expected for neutrino oscillations with the so-called large mixing angle parameters and also with an undistorted spectrum. A search for matter-enhancement effects in the Earth through a possible day-night asymmetry in the charged-current integral rate is consistent with no asymmetry. Including results from other experiments, the best-fit values for two-neutrino mixing parameters are {delta}m{sup 2}=(8.0{sub -0.4}{sup +0.6})x10{sup -5}more » eV{sup 2} and {theta}=33.9{sub -2.2}{sup +2.4} degrees. « less
Rapid method for yearly LULC classification using Random Forest and incorporating time-series NDVI and topography: a case study of Thanh Hoa province, Vietnam

Abstract Land-use and land-cover (LULC) mapping in the complex area is a challenging task due to the mixed vegetation patterns, and rough mountains with fast-flowing rivers. In Vietnam, LULC update is not frequently. In this study, we applied a supervised machine learning (Random forest—RF) approach to mapping LULC in Thanh Hoa province, Vietnam from 2011 to 2015 utilizing multi-temporal Normalized Difference Vegetation Index (NDVI) data from MODIS, combined with topographic features. Random forest classification (RFC) reached a total prediction accuracy of 91% and Kappa coefficient (K) of 0.89 across eight LULCs. Besides, the results showed that the features extracted from time-series NDVI comprising the mean of yearly NDVI, the sum of NDVI, and the topography were the important variables controlling the LULC classification. For similar studies on the distribution of LULC, the method proposed in this study could be helpful.
Annular array beamforming for 2D arrays with reduced system channels

Annular arrays can operate with a small number of channels because the shape of the physical elements matches the acoustic phase fronts. The symmetry of the annular array provides axisymmetric focusing without the need for additional beamforming channels. An annular array structure can be constructed by connecting elements of a 2D array and therefore a similar reduction in the number of delay channels required can be achieved described by D. G. Bailey et al. and R. Bele (1987). We present simulation results for annular array apertures with a diameter of 20-26 mm and design frequency in the 5-8 MHz range. The simulations are used to determine the required number of annular rings (around 20), the effect of the size of the underlying 2D array elements (should be < 200 um), and the optimal ring widths for a particular design with 20 rings (325 um). Simulations of a 20 ring design with a 26 mm aperture show that the -6 dB beamwidths are less than 0.5 mm over a depth of field from 1 to 5 cm with a single transmit focus. The azimuthal and elevation beam widths are, as expected, equivalent. Experimental measurements of the field at the focal point show good agreement with the model.
New Hybrid Nanocomposites with Catalytic Properties Obtained by In Situ Preparation of Gold Nanoparticles on Poly (Ionic Liquid)/Poly (4-Vinylpyridine) Nanofibers

In this work, we report the obtaining of new hybrid nanocomposites with catalytic activity formed by nanofibers of polymer blends and gold nanoparticles. The nanofibers were obtained by electrospinning blends of a poly (ionic liquid) (PIL) and its precursor polymer, poly (4-vinyl pyridine) (P4VPy). The characteristics of the nanofibers obtained proved to be dependent on the proportion of polymer in the blends. The nanofibers obtained were used to synthesize, in situ, gold nanoparticles on their surface by two-step procedure. Firstly, the adsorption of precursor ions on the nanofibers and then their reduction with sodium borohydride to generate gold nanoparticles. The results indicated a significant improvement in the performance of PIL-containing nanofibers over pure P4VPy NFs during ion adsorption, reaching a 20% increase in the amount of adsorbed ions and a 6-fold increase in the respective adsorption constant. The catalytic performance of the obtained hybrid systems in the reduction reaction of 4-nitrophenol to 4-aminophenol was studied. Higher catalytic conversions were obtained using the hybrid nanofibers containing PIL and gold nanoparticles achieving a maximum conversion rate of 98%. Remarkably, the highest value of kinetic constant was obtained for the nanofibers with the highest PIL content.
Leadership and Work Engagement Effectiveness within the Technology Era

There is rising awareness regarding the entrepreneurship evolution within underdeveloped regions across the world and how it is affected by leadership initiatives regarding the work engagement of young entrepreneurs; an underlining series of studies should be performed, considering the job performance attributes specific to each given area. Entrepreneurship is a source of economic vitality that must be subject to correctly performed leadership initiatives that need to strive for training young entrepreneurs to understand and assess the strong and weak points of their business (idea) in order to successfully compete with larger organizations. The current study aims for explaining the relationship between leadership behavior (as transformational and transactional) and the underlying mechanism of work engagement (with a special focus on job resources). The current research used a convenience sample based on a voluntary response sampling method, engaging 508 young entrepreneurs from the NE region of Romania. Results prove that transformational leadership and work engagement are active contributors to the job performance. The current study is one of the few in the literature that enhances simultaneously both transformational and transactional leadership, along with work engagement as predictors of job performance, since previous research has only considered transformational leadership and disregarded the role of transactional leadership in followers’ job performance.
Phenomena of Time Resonances Explosions for the Compound-Clot Decays in High-Energy Nuclear Reactions

The phenomenon of time resonances (or explosions) can explain the exponential reduction of the energy, which is accompanied for the certain degree by slight fluctuations under some conditions in the range of the energy strongly overlapped compound-resonances. These resonant explosions correspond to formation of several highly-exited non-exponentially decaying nuclear clots (partial compound nuclei consisting of several small groups of projectile nucleons and targets). This paper is a continuation and expansion of theoretical authors' work, which is a more general self-consistent version of the time-evolution approach in comparison with the traditional Izumo-Araseki time compound-nucleus model.
Fethiye: Turkey’s ‘Little Britain' – residential tourists’ identity and relationships

ABSTRACT This paper examines the Turkish resort town of Fethiye’s large British population of permanent residents, who have added to the physical and cultural character of the town. To understand why these individuals decided to relocate to Fethiye, and what their lives are like in the town, 17 semi-structured interviews with British residential tourists were conducted. The paper reveals a complex identity paradox, where many feel that the stigma surrounding the term ‘expat’, and what it means to be a ‘Brit abroad’, has impacted their identity, relationships and judgement of fellow residential tourists. The study also uncovers the motivational characteristics for their relocation, from which a strong financial element towards the choice of Turkey was revealed. Host–guest relationships are also explored, revealing largely positive attitudes towards the Turkish community.
The Relationship Between Kimberlitic Magmatism and Electrical Conductivity Anomalies in the Mantle

Kimberlites are igneous rocks whose formation remains enigmatic due to their severely altered nature, highly variable compositions and rapid ascent through the lithosphere. The spatiotemporal distribution of kimberlites suggests that mantle metasomatism may play an essential role in their emplacement. Since the magnetotelluric (MT) method is sensitive to metasomatic mantle modification in the forms of interconnected minerals and water, we compiled MT models from Australia, Brazil, Botswana, Canada, Namibia, South Africa and the USA, calculated water content variations and compared them to the distribution of kimberlites. Results indicate that kimberlites mostly ascend through hydrated/metasomatized lithosphere and avoid both dry and heavily metasomatized lithosphere. Diamondiferous kimberlites preferentially occur on moderately metasomatized lithosphere, with the diamondiferous rate increasing with the degree of metasomatism in Archean terranes and decreasing in Proterozoic terranes. These results link geophysical observations of mantle metasomatism to kimberlite magmatism and will improve mineral systems models for diamond exploration.
Effect of divalent and trivalent metal ions on artificial membrane permeation of fluoroquinolones

The purpose of the present study was to evaluate the predictability of PAMPA for the effect of metal ions on the bioavailability of fluoroquinolones (FQ). Eleven FQs and seven metal ions were employed in this study. The PAMPA membrane consisted of a 10 % soybean lecithin (SL) – decane solution. A drug solution in MES buffer with or without a metal ion (added as a chloride salt) was added to the donor compartment. In the absence of metal ions, FQ showed relatively high permeability (> 5 × 10-6 cm/sec) in SL-PAMPA despite their hydrophilic and zwitterionic properties. As the PAMPA permeability ratio with/without metal ions became smaller, the urinary excretion and AUC ratios tended to be smaller, suggesting that SL-PAMPA is a suitable in vitro model to evaluate the potential effect of metal ions on the bioavailability of FQ. However, the reduction in AUC and urinary excretion was overestimated for low solubility metal ion formulations (dried aluminum hydroxide gel and La2(CO3)3・8H2O). In such cases, the dissolution of the metal ion formulations and the permeation of FQs should be simultaneously evaluated.
Charge dynamics in underdopedNd2−xCexCuO4: Pseudogap and related phenomena

We have investigated the temperature and doping variations of optical and transport properties in the electron-doped high-${T}_{\mathrm{c}}$ cuprate crystals ${\mathrm{Nd}}_{2\ensuremath{-}x}{\mathrm{Ce}}_{x}{\mathrm{CuO}}_{4}$ $(0l~xl~0.15). $ In the optical spectra of underdoped crystals $(xl0.15),$ a notable pseudogap is observed at low temperatures. A Drude-like response evolves concomitantly with pseudogap formation. Both the magnitude $({\ensuremath{\Delta}}_{\mathrm{PG}})$ and onset temperature ${(T}^{*})$ of the pseudogap decrease with electron doping, while holding the relation that ${\ensuremath{\Delta}}_{\mathrm{PG}}\ensuremath{\approx}{10k}_{\mathrm{B}}{T}^{*}. $ The ${\ensuremath{\Delta}}_{\mathrm{PG}}$ is comparable to the magnitude of the pseudogap at around $(\ensuremath{\pi}/2,\ensuremath{\pi}/2)$ in the photoemission spectra reported by Armitage et al. [Phys. Rev. Lett. 88, 257001 (2002)], which indicates that the pseudogap appearing in the optical spectra is identical to that discerned by the photoemission spectroscopy. The scattering rate spectra $1/\ensuremath{\tau}(\ensuremath{\omega})$ of the $x=0.10\char21{}0.15$ crystals show a kink structure at around 0.07 eV, which can be ascribed not to the pseudogap but to the electron-phonon coupling. In accordance with the evolution of the Drude response, the in-plane resistivity begins to decrease rapidly at around ${T}^{*}$ in the underdoped region. The out-of-plane resistivity shows an even more distinct decrease below ${T}^{*}. $ This is because the interplane charge transport is governed by electronic states at around $(\ensuremath{\pi},0),$ where the quasiparticle spectral weight is accumulated in the case of the electron-doped system. This is contrary to the hole-doped case with the pseudogap around this point. The origin of the pseudogap has been ascribed to the antiferromagnetic spin correlation, which is consistent with the evolution of a two-magnon band in the ${B}_{1\mathrm{g}}$ Raman spectra below ${T}^{*}. $ The pseudogap phenomenon in the electron-doped cuprate has been argued comparatively with that of the hole-doped cuprate.
How Knowledgeable are Non-Radiology Doctors on Ionizing Radiation

Background: Due to the risk of hazard from ionizing radiation, non-radiology doctors who refer patients to the radiology departments ought to be knowledgeable enough about what their patients are subjected to. The high throughput of radiology requests in our centre in Nigeria justifies this study. Aim: To evaluate the level of knowledge of non-radiology doctors on ionizing radiation with a view to reviewing local protocols on justification of investigations involving ionizing radiation. Material and method: Eighty (80) structured questionnaires were administered to non-radiology doctors practising in different hospitals n Kano city, Nigeria. Answers were elicited on radiation protection principles, concept of ionizing radiation, radiation effects, imaging modalities that emit ionizing radiation, radiation measurements and attitude towards ionizing radiation. Results: Seventy questionnaires were returned out of the eighty sent out with sixty-four (80 %) being properly filled. Knowledge of non-radiology doctors was variable on different indices; 15.6 %, n = 10 (fundamental principles of radiation protection); 45.3 %, n = 29 (effects of ionizing radiation); 34.4 %, n = 22 (knowledge on ionizing property of radiation); 73 %, n = 47 (emission of ionizing radiation by computed tomography); and 85.9 %, n = 55 (interest in specific modality). Conclusion: Non-radiology doctors in Kano metropolis have fairly good knowledge of potential hazards of radiation.
Academic Malpractice in Tests and Exams from an International Perspective

Cheating in exams and other forms of academic dishonesty have been reported to be a serious issue in many countries. A lot of research has been conducted on the topic, but it focuses mainly on the US context. Studies pertaining to the problem in other countries are rather scarce. The existing research considers the issue from different perspectives. Some studies concentrate on the scope of the problem in a particular country, others choose to research individual and contextual factors in cheating, or students’ perceptions of and attitudes towards exam malpractice. The surveys are often restricted to selected nationalities, the questions arelimited to the frequency of cheating and they rarely include reference to the methods used. In reaction to the rarity of research on cheating methods among students from different cultural backgrounds, an international questionnaire survey was undertaken. Its aim, among others, was to answer two research questions: (1) What methods do students use to cheat in tests and exams? (2) Are there significant cultural differences in the way students cheat in tests and exams? Students from France, Germany, Italy, Spain, Ukraine, the USA and other countries were asked in an online questionnaire about the methods they have used to cheat in tests and exams. The results of the survey conducted on 1309 students show that there are similarities but also differences between the cultures with reference to the scope and to the methods used to cheat. The findings should be taken into consideration in classroom and high-stakes assessment, but also in any cross-national comparisons of students’ outcomes. Teachers, administrators and researchers ought to be aware that the differences in attitudes towards academic cheating between the nationalities may influence test validity.
Holographic Dark Energy with Modified Chaplygin Gas and Scalar Field in (2 + 1)−Dimensional Space-time

In this paper, we generalized the work of Sheykhi (2011) and Ghose (2014) and establish the connection between Holographic Dark energy interacting with modified Chaplygin gas and then obtain the evolution of holographic dark energy with corresponding equation of state. In the first part of the paper, we have generalized the work of Sheykhi (2011) by choosing Hubble radius as the system’s IR cut-off and constructing the analytical form of the potentials as a function of scalar fields, namely V = V (ϕ) as well as this dynamics of the scalar fields as a function of time, namely ϕ = ϕ(t) then we have implemented the connection between Holographic dark energy and scalar fields model including quintessence, tachyon, K−essence and dilaton energy density in a (2+1)−dimensional spacetime FRW universe. In the second part of the paper, we have generalized the work of Ghose (2014) and investigate holographic dark energy (HDE) correspondence of interacting Modified Chaplygin Gas (MCG), and obtained evolution of the HDE with the corresponding equation of state. Considering the present value of the density parameter a stable configuration is found which accommodates Dark Energy (DE). We note a connection between DE and Phantom fields. It reveals that the DE might have evolved from a Phantom state in the past. We also obtained the stability of the model and analyzed the physical and geometrical interpretations of the cosmological model with reference to the (2 + 1)−dimensional spacetime.
Power production using a batch double‐chamber microbial fuel cell from brewery wastewater: Effects of electron acceptors

In recent decades, shortage and crisis of energy being a serious issue of concern all over the world as the fossil fuel reserves have been diminishing. A particular emphasis has been given for bio‐energy harvesting from waste and cellulosic biomass by employing an efficient conversion system. Among these, microbial fuel cell (MFC) systems are an emerging promising technology for the effective wastewater treatment. However, the collective effect of waste substrates, inoculum composition, and catholyte concentrations on the performance of MFC system remains unclear. Hence, this study aimed to investigate the effect of electron acceptors under different set of parameters in response to its electrochemical performance inoculum chemical oxygen demand (COD) concentration and type of the electron acceptor on the performance of the electrochemical has been studied. A dual‐chamber MFC with 0.4 to 0.6 M values of potassium permanganate (KMnO4) and Ferricyanide K3[Fe(CN)6], (900‐2520 mgL−1) of COD values, and oxygen as a control substance were used. The experiments were carried out in a batch mode for 20 days of operation. The results reveal that MFC with 0.4 M KMnO4 provides an external output voltage of 310.09 ± 0.06 mV and external output power density value of 400.4 ± 0.46 mWm−2 while 0.4 M K3[Fe(CN)6] results an external output voltage of 252.18 ± 0.12 mV and an external output power density value of 380.28 ± 0.24 mWm−2. Analysis of variance was done using central composite design approach to support the significance of each experimental factors on the responses and the result shows that the confidence interval of 95% for all the parameters that were statistically significant.