Miracle-dz/UniFAR-FTUs huggingface dataset:
THE SEMIGROUPS OF BINARY SYSTEMS AND SOME PERSPECTIVES

Given binary operations "∗" and "◦" on a set X, define a product binary operation "2" as follows: x2y := (x ∗ y) ◦ (y ∗ x). This in turn yields a binary operation on Bin(X), the set of groupoids defined on X turning it into a semigroup (Bin(X), 2)with identity (x∗y = x) the left zero semigroup and an analog of negative one in the right zero semigroup (x ∗ y = y). The composition 2 is a generalization of the composition of functions, modelled here as leftoids (x∗y = f (x)), permitting one to study the dynamics of binary systems as well as a variety of other perspectives also of interest. § 0. In what follows we associate with a set X a semigroup (Bin(X), 2)which generalizes in a rather natural way the composition of functions f : X → X. Classes of groupoids defined on a set X may form semigroups or even ideals and the axioms defining these classes may be analyzed according to the properties of these classes in (Bin(X), 2)for the set X. The fact that some sets of axioms produce subsemigroups of (Bin(X), 2)for the set X, whereas other sets do not, appears to be an interesting and possibly important distinction for the class under discussion. Some classes which appear to be new are also pointed out, including the linear groupoids over rings with identity, usually taken to be commutative. The strong bounded d-algebras are shown to be an interesting class described as a convenient intersection of three other classes each determined by one of the axioms. Given the standard "equivalence" these algebras will (indirectly) satisfy several M V -axioms. Other properties such as separability are looked at as well.
Ballooning instability of a thin current sheet in the high‐Lundquist‐number magnetotail

Two‐dimensional simulations of the magnetotail in the high‐Lundquist‐number regime indicate the slow growth of thin current sheets and an impulsive intensification of the cross‐tail current density at near‐Earth distances during a short interval just before the onset of the expansion phase, consistent with multi‐satellite observations. Such a two‐dimensional magnetotail, symmetric along y and containing a thin current sheet, is found to be unstable to a symmetry‐breaking, ideal compressible ballooning instability with high wave number along y. The linear instability is demonstrated by numerical solutions of the ideal ballooning eigenmode equation for a sequence of two‐dimensional thin current sheet configurations in the impulsive growth phase. Line‐tied boundary conditions at the ionosphere are imposed, and shown to play a crucial role in the stability analysis. It is suggested that the ideal ballooning instability, which has strong spatial variation along y, provides a possible mechanism for disrupting the cross‐tail current at onset.
40-Hz coherent oscillations in neuronal systems

A characteristic coherent oscillation with a frequency of 40 Hz which relates to some functions of the brain is shown to be intrinsic due to the nonlinear firing of spikes of neurons when the network is situated in a stimulus-induced oscillatory state. This oscillation mode is associated with a synchronized firing pattern, and is robust to a variety of couplings between the neurons and to a wide range of external stimuli. @S1063-651X~97! 05409-3# PACS number~s! : 87.10. 1e Recently, considerable attention has been drawn to the existence of coherent synchronized oscillatory activity in many neuronal systems. It has been found experimentally that large-scale synchronized neuronal activity is often accompanied by oscillatory firing patterns with a frequency about 40 Hz ~in the g band, usually referred to as 40-Hz oscillations ! @ 1 #. For example, in the cat’s visual cortex and in the awake ~or in rapid-eye-movement sleep! state of humans, coherent synchronized oscillatory responses have been observed through local field potential and multiunit activities @1#. It has also been shown that the synchronization probability depends on the configuration of visual stimuli and that it does reflect some of the gestalt criteria that are used for scene segmentation @1#. Therefore this kind of long-distance synchronized spatiotemporal dynamical behavior has been suggested as a mechanism for the binding of spatially distributed features into a coherent object @1‐3#. The neurons which process different features of the same object oscillate with a fixed phase, while neurons which code different objects oscillate with different phases or at random. To date, there have been some theoretical studies on the above mentioned coherent oscillations; these are based either on a model of coupled oscillators or a model of integrate and fire; few of them have taken into account the detailed features of the neuronal activity, such as its recovery or its adaptation after the firing of spikes. Although a completely synchronized oscillation with zero phase difference may be obtained in these models, all the couplings are assumed to be excitatory @4#, an assumption which seems to be oversimplified and which may not be consistent with the real situation. In particular, the biophysical origin of these coherent oscillations and their relationship with the synaptic interaction ~or coupling! , as well as with the external stimuli, are not well studied. In addition, the frequency spectrum of the oscillations has rarely been addressed theoretically, and the question of how the synchrony is established and what role the oscillatory firing plays in the dynamical informational pro
The Dependence of Cloud Particle Size on Non-Aerosol-Loading Related Variables

An enhanced concentration of aerosol may increase the number of cloud drops by providing more cloud condensation nuclei (CCN), which in turn results in a higher cloud albedo at a constant cloud liquid water path. This process is often referred to as the aerosol indirect effect (AIE). Many in situ and remote sensing observations support this hypothesis (Ramanathan et al. 2001). However, satellite observed relations between aerosol concentration and cloud drop size are not always in agreement with the AIE. Based on global analysis of cloud effective radius (
Existence of bifurcation in macroeconomic dynamics: Grandmont was right

Grandmont (1985) found that the parameter space of the most classical dynamic general-equilibrium macroeconomic models are stratified into an infinite number of subsets supporting an infinite number of different kinds of dynamics, from monotonic stability at one extreme to chaos at the other extreme, and with all forms of multiperiodic dynamics between. But Grandmont provided his result with a model in which all policies are Ricardian equivalent, no frictions exist, employment is always full, competition is perfect, and all solutions are Pareto optimal. Hence he was not able to reach conclusions about the policy relevance of his dramatic discovery. As a result, Barnett and He (1999, 2001, 2002) investigated a Keynesian structural model, and found results supporting Grandmonti¯s conclusions within the parameter space of the Bergstrom- Wymer continuous-time dynamic macroeconometric model of the UK economy. That prototypical Keynesian model was produced from a system of second order differential equations. The model contains frictions through adjustment lags, displays reasonable dynamics fitting the UK economyi¯s data, and is clearly policy relevant. In addition, initial results by Barnett and Duzhak (2006) indicate the possible existence of Hopf bifurcation within the parameter space of recent New Keynesian models. Lucas-critique criticism of Keynesian structural models has motivated development of Euler equations models having policy-invariant deep parameters, which are invariant to policy rule changes. Hence, we continue the investigation of policy-relevant bifurcation by searching the parameter space of the best known of the Euler equations general-equilibrium macroeconometric models: the Leeper and Sims (1994) model. We find the existence of singularity bifurcation boundaries within the parameter space. Although never before found in an economic model, our explanation of the relevant theory reveals that singularity bifurcation may be a common property of Euler equations models. These results further confirm Grandmonti¯s views. Beginning with Grandmonti¯s findings with a classical model, we continue to follow the path from the Bergstrom-Wymer policy-relevant Keynesian model, to New Keynesian models, and now to Euler equations macroeconomic models having deep parameters. Grandmont was right.
The use of Jeffreys priors for the Student-t distribution

The Jeffreys-rule prior and the marginal independence Jeffreys prior are recently proposed in Fonseca et al. [Objective Bayesian analysis for the Student-t regression model, Biometrika 95 (2008), pp. 325–333] as objective priors for the Student-t regression model. The authors showed that the priors provide proper posterior distributions and perform favourably in parameter estimation. Motivated by a practical financial risk management application, we compare the performance of the two Jeffreys priors with other priors proposed in the literature in a problem of estimating high quantiles for the Student-t model with unknown degrees of freedom. Through an asymptotic analysis and a simulation study, we show that both Jeffreys priors perform better in using a specific quantile of the Bayesian predictive distribution to approximate the true quantile.
The photonic band edge optical diode

Using numerical methods, we study pulse propagation near the band edge of a one‐dimensional photonic band gap material with a spatial gradiation in the linear refractive index, together with a nonlinear medium response. We find that such a structure can result in unidirectional pulse propagation. That is, the field will be transmitted for, say, a left‐to‐right direction of propagation, while for right‐to‐left nearly complete reflection occurs. This behavior constitutes the operational mechanism for a passive optical diode.
Boundary elements solution of stokes flow between curved surfaces with nonlinear slip boundary condition

This work presents a boundary integral equation formulation for Stokes nonlinear slip flows based on the normal and tangential projection of the Green's integral representational formulae for the velocity field. By imposing the surface tangential velocity discontinuity (slip velocity) in terms of the nonlinear slip flow boundary condition, a system of nonlinear boundary integral equations for the unknown normal and tangential components of the surface traction is obtained. The Boundary Element Method is used to solve the resulting system of integral equations using a direct Picard iteration scheme to deal with the resulting nonlinear terms. The formulation is used to study flows between curved rotating geometries: i.e., concentric and eccentric Couette flows and single rotor mixers, under nonlinear slip boundary conditions. The numerical results obtained for the concentric Couette flow is validated again a semianalytical solution of the problem, showing excellent agreements. The other two cases, eccentric Couette and single rotor mixers, are considered to study the effect of different nonlinear slip conditions in these flow configurations. © 2012 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2013
Electro-Thermal Analysis and Monte Carlo Simulation for Thermal Issue in Si Devices

Nowadays, precise prediction of heat generation in semiconductor devices is important. An electro-thermal analysis is an attractive method to predict heat generation in devices. In this analysis, momentum and energy relaxation times are taken as the important parameters. Calculated heat generation density is dependent on the energy relaxation time. Conventionally, these relaxation times have been determined by simple models. For a more precise prediction of the relaxation times, Monte Carlo (MC) simulation should be employed. In this research, the impact of these relaxation times on the heat generation in a semiconductor device is evaluated. The results of an electro-thermal analysis using conventional relaxation times (conventional model) and of one using the relaxation times from a MC simulation (MC model) are compared. The calculation results show that the conventional model overestimates the heat generation density especially under a high electric field. The estimated heat generation density of the conventional model is 10% and 25% larger in the case of 100 and 500 kV/cm electric fields, respectively. It can be concluded that, for the thermal design of high-power semiconductor devices in power electronics, appropriate values of the relaxation times, which are obtained from the MC simulation, are required.
The effectiveness of speech pathology telepractice during COVID-19 pandemic for Autistic children in Indonesia

The education sector is one of the sectors which is most affected by the Coronavirus Disease 2019 (COVID-19) pandemic which can interfere with the achievement of one of the Sustainable Development Goals (SDGs) targets, such as quality education. Furthermore, with online learning not only regular education, but also special education faces many obstacles. One of the special education programs for children with autism is speech therapy. Therefore, several innovations have been created so that therapy process can continue. One of those innovations is that speech pathology telepractice program which is conducted at the Autis Center of Blitar City. This program involves the role of parents at home and therapists via teleconference. In this study, the effectiveness of speech pathology telepractice was measured through the Wilcoxon-signed rank test and the results obtained p-value = 0.011, which means that there are differences in the speaking ability of children with autism before and after the implementation of speech pathology telepractice. This ability was measured based on several activities and assessment components which had set by the therapist. Moreover, the results of interview with several therapists and parents can be the basis for recommendations regards to the speech pathology telepractice programs to be implemented outside of Autis Center Blitar City which has not yet implemented the speech pathology telepractice. Thus, children with autism do not experience reduction in the development of their speech skills during the COVID-19 pandemic. © 2022 American Institute of Physics Inc. All rights reserved.
CARLEMAN ESTIMATES AND INVERSE PROBLEMS FOR SECOND ORDER HYPERBOLIC EQUATIONS

The author considers the problem of finding the time-independent coefficients of a second order hyperbolic equation from the Cauchy data at the initial moment and on a part of the lateral surface of a cylindrical domain. Estimates of Hormander's Carleman type are obtained. On the basis of these estimates the uniqueness of the extension of the Cauchy data is proved, as well as the uniqueness of recovering the time-independent coefficients of hyperbolic equations.Bibliography: 9 titles.
Discrete-Continuum Transition at Interfaces of Nanocomposites

A number of micromechanical investigations have been performed to predict behaviour of composite interfaces, showing that the detailed behaviour of the material at these interfaces frequently dominates the behaviour of the composite as a whole. The interfacial interaction is an extremely complex process due to continuous evolution of interfacial zones during deformation and this is particularly true for carbon nanotubes since the interfacial interaction is confined to the discrete molecular level. The atomic strain concept based upon Voronoi tessellation allows analyzing the molecular structure atom by atom, which may give a unique insight into deformation phenomena operative at molecular level such as interface behaviour in nanocomposites.
Implications for conservation assessment from flux in the botanical record over 20 years in southwest Ghana

Abstract At best, conservation decisions can only be made using the data available at the time. For plants and especially in the tropics, natural history collections remain the best available baseline information upon which to base conservation assessments, in spite of well‐documented limitations in their taxonomic, geographic, and temporal coverage. We explore the extent to which changes to the plant biological record over 20 years have changed our conception of the conservation importance of 931 plant taxa, and 114 vegetation samples, recorded in forest reserves of the southwest Ghana biodiversity hotspot. 36% of species‐level assessments changed as a result of new distribution data. 12% of species accepted in 2016 had no assessment in 1996: of those, 20% are new species publications, 60% are new records for SW Ghana, and 20% are taxonomic resolutions. Apparent species ranges have increased over time as new records are made, but new species publications are overwhelmingly of globally rare species, keeping the balance of perceived rarity in the flora constant over 20 years. Thus, in spite of considerable flux at the species record level, range size rarity scores calculated for 114 vegetation samples of the reserves in 1996 and 2016 are highly correlated with each other: r(112) = 0.84, p < . 0005, and showed no difference in mean score over 20 years: paired t(113) = −0.482, p = . 631. This consistency in results at the area level allows for worthwhile conservation priority setting over time, and we argue is the better course of action than taking no action at all.
Persistence of sharp acoustic backscatter transitions observed in repeat 400 kHz multibeam echosounder surveys offshore Panama City, Florida, over 1 and 24 months

The Target and Reverberation Experiment 2013 (TREX13), conducted offshore Panama City, FL, from April to June 2013, sought to determine which environmental parameters contribute the most to acoustic reverberation and control sonar performance prediction modeling for acoustic frequencies between 1 kHz and 10 kHz. In that context, a multibeam echosounder operated at 400 kHz was used to map the seafloor relief and its high-frequency acoustic backscatter characteristics along the acoustic propagation path of the reverberation experiment. Repeat surveys were conducted a month apart, before and after the main reverberation experiment. In addition, repeat surveys were conducted at 200 kHz in April 2014. Similar mapping work was also conducted in April 2011 during a pilot experiment (GulfEx11) near the site chosen for TREX13. Both experiments revealed a persistent occurrence of sharp transitions from high to low acoustic backscatter at the bottom of swales. Hypotheses are presented for observable differences in b.
General rehabilitation for the Post-COVID-19 condition: A narrative review

COVID-19 significantly impacts the acute phase or the period after being infected by severe acute respiratory syndrome coronavirus-2. Studies have shown it has affected multiorgan and needs continuous care by a multidisciplinary team. Nowadays, guidance is required to assist the recovery process of survivors who reported at least one symptom as a residual effect. This study aims to describe the rehabilitation management of post-COVID-19 conditions. As the number of survivors seems to be increasing, it is expected that COVID-19 survivors will recover through a holistic approach by all physicians. Comprehensive rehabilitation for long COVID or COVID-19-related illnesses includes exercising, nutrition, education, managing voice, breathlessness, neurocognitive problems, mental health, feeding problems, and daily activities. Specific recommendations have already been published to support rehabilitation for survivors in every targeted organ. Supportive care, especially rehabilitation programs, is recently an urgent knowledge in this pandemic.
Diversity and Comparison of Intestinal Desulfovibrio in Patients with Liver Cirrhosis and Healthy People

Desulfovibrio belongs to Sulfate-reducing bacteria (SRB), which are widely present in anaerobic environments, including the human gut. Desulfovibrio has been associated with many human diseases, including chronic liver disease. However, the characteristics and difference of Desulfovibrio from fecal samples of healthy volunteers (HV) and patients with liver cirrhosis (LC) have not been fully elucidated. Here, we isolated Desulfovibrio from the feces of 6 HV and 9 LC, and 88 Desulfovibrio strains were obtained. In the feces of HV, 55% of isolated strains were D. desulfuricans, followed by D. intestinalis (15%), D. simplex (11%), D. piger (9%), D. legallii (4%), Cupidesulfovibrio oxamicus (4%) and D. fairfieldensis (2%). However, only D. desulfuricans (60%) and C. oxamicus (40%) were isolated from fecal samples of patients with LC. Our results suggest that there was a significant difference in the desulfurization ability and the H2S production ability of different Desulfovibrio. Desulfovibrio. Furthermore, we found that Desulfovibrio isolated from the patients with LC generally had a higher hydrogen sulfide production capacity, gastrointestinal tolerance, and levels of antibiotic resistance than the same species isolated from HV. Our findings suggested that Desulfovibrio may be associated with the occurrence and development of liver cirrhosis.
Physiological and subjective responses to a novel military specific load carriage treadmill protocol

Purpose: Treadmill-based load carriage protocols typically use a single fixed speed; however, these are not representative of occupational load carriage tasks. This study aimed to quantify the metabolic, cardiovascular, thermal, neuromuscular, and perceptual responses to a treadmill-based, military-specific, fast load carriage protocol (FLCP). This protocol comprised of carrying 25 kg, for 20 minutes at 5.1 km·h -1 ; 40 minutes, at 6.5 km·h -1 ; and 8 x 9 s shuttles, at 11 km·h -1 with 11 s recovery. Methods: Twelve men (age, 27 ± 6 y; stature, 1.83 ± 0.05 m; body mass, 80.6 ± 8.0 kg; maximal oxygen uptake, 52.7 ± 5.5 mL·kg -1 ·min -1 ), completed a FLCP during which oxygen consumption (VO 2 ), heart rate, core body temperature, and perceptual ratings were recorded. Performance assessments (weighted counter-movement jump [wCMJ], maximal isometric voluntary contraction [MIVC] of the quadriceps, seated medicine ball throw [SMBT]) were completed pre-FLCP, immediately-post and, 30, 60, 120 minutes’ post. Results: V̇O 2 was similar for 5.1 km·h -1 , but increased by 7.4% during the 40 minutes at 6.5 km·h -1 ( p = 0.013). Core temperature increased by 0.92 ± 0.22 ºC in response to the FLCP. Post-FLCP, SMBT was not dissimilar across measurement points, ( p = 0.315), however, MIVC peak force reduced by 12.6 ± 10.9% 60 minutes post-FLCP ( p = 0.031), and wCMJ height decreased by 8.7 ± 5.9% 120 minutes post-FLCP ( p = 0.011). Conclusion: The completion of the FLCP does not affect upper body power (SMBT), but appears to modestly decrease lower body explosiveness (wCMJ and MIVC) up to two hours post. Future investigations can use the FLCP protocol to investigate occupationally relevant scenarios, such as the interaction between physical and cognitive performance during load carriage, or the implications of multiple repeated load carriage bouts.