bluuebunny/crossref_metadata_2025 huggingface dataset:
Low-dimensional Convolutional Neural Network for Solar Flares GOES Time-series Classification
Authors: Landa Vlad , Reuveni Yuval
Published: January 2022

Space weather phenomena such as solar flares have a massive destructive power when they reach a certain magnitude. Here, we explore the deep-learning approach in order to build a solar flare-forecasting model, while examining its limitations and feature-extraction ability based on the available Geostationary Operational Environmental Satellite (GOES) X-ray time-series data. We present a multilayer 1D convolutional neural network to forecast the solar flare event probability occurrence of M- and X-class flares at 1, 3, 6, 12, 24, 48, 72, and 96 hr time frames. The forecasting models were trained and evaluated in two different scenarios: (1) random selection and (2) chronological selection, which were compared afterward in terms of common score metrics. Additionally, we also compared our results to state-of-the-art flare-forecasting models. The results indicates that (1) when X-ray time-series data are used alone, the suggested model achieves higher score results for X-class flares and similar scores for M-class as in previous studies. (2) The two different scenarios obtain opposite results for the X- and M-class flares. (3) The suggested model combined with solely X-ray time-series fails to distinguish between M- and X-class magnitude solar flare events. Furthermore, based on the suggested method, the achieved scores, obtained solely from X-ray time-series measurements, indicate that substantial information regarding the solar activity and physical processes are encapsulated in the data, and augmenting additional data sets, both spatial and temporal, may lead to better predictions, while gaining a comprehensive physical interpretation regarding solar activity. All source codes are available at https://github.com/vladlanda.
Give Me a Few Hours: Exploring Short Timescales in Rubin Observatory Cadence Simulations
Authors: Bellm Eric C. , Burke Colin J. , Coughlin Michael W. , Andreoni Igor , Raiteri Claudia M. , Bonito Rosaria
Published: January 2022

The limiting temporal resolution of a time-domain survey in detecting transient behavior is set by the time between observations of the same sky area. We analyze the distribution of visit separations for a range of Vera C. Rubin Observatory cadence simulations. Simulations from families v1.5–v1.7.1 are strongly peaked at the 22 minute visit pair separation and provide effectively no constraint on temporal evolution within the night. This choice will necessarily prevent Rubin from discovering a wide range of astrophysical phenomena in time to trigger rapid follow-up. We present a science-agnostic metric to supplement detailed simulations of fast-evolving transients and variables and suggest potential approaches for improving the range of timescales explored.
Rapid Bursts of Magnetically Gated Accretion in the Intermediate Polar V1025 Cen
Authors: Littlefield Colin , Lasota Jean-Pierre , Hameury Jean-Marie , Scaringi Simone , Garnavich Peter , Szkody Paula , Kennedy Mark , Leichty McKenna
Published: January 2022

Magnetically gated accretion has emerged as a proposed mechanism for producing extremely short, repetitive bursts of accretion onto magnetized white dwarfs in intermediate polars (IPs), but this phenomenon has not been detected previously in a confirmed IP. We report the 27 day TESS light curve of V1025 Cen, an IP that shows a remarkable series of 12 bursts of accretion, each lasting for less than 6 hours. The extreme brevity of the bursts and their short recurrence times (∼1–3 days) are incompatible with the dwarf-nova instability, but they are natural consequences of the magnetic gating mechanism developed by Spruit and Taam to explain the Type II bursts of the accreting neutron star known as the Rapid Burster. In this model, the accretion flow piles up at the magnetospheric boundary and presses inward until it couples with the star’s magnetic field, producing an abrupt burst of accretion. After each burst, the reservoir of matter at the edge of the magnetosphere is replenished, leading to cyclical bursts of accretion. A pair of recent studies applied this instability to the suspected IPs MV Lyr and TW Pic, but the magnetic nature of these two systems has not been independently confirmed. In contrast, previous studies have unambiguously established the white dwarf in V1025 Cen to be significantly magnetized. The detection of magnetically gated bursts in a confirmed IP therefore validates the extension of the Spruit and Taam instability to magnetized white dwarfs.
Inertial-range Magnetic-fluctuation Anisotropy Observed from Parker Solar Probe’s First Seven Orbits
Authors: Zhao L.-L. , Zank G. P. , Adhikari L. , Nakanotani M.
Published: January 2022

Solar wind turbulence is anisotropic with respect to the mean magnetic field. Anisotropy leads to ambiguity when interpreting in situ turbulence observations in the solar wind because an apparent change in the measurements could be due to either the change of intrinsic turbulence properties or to a simple change of the spacecraft sampling direction. We demonstrate the ambiguity using the spectral index and magnetic compressibility in the inertial range observed by the Parker Solar Probe during its first seven orbits ranging from 0.1 to 0.6 au. To unravel the effects of the sampling direction, we assess whether the wave-vector anisotropy is consistent with a two-dimensional (2D) plus slab turbulence transport model and determine the fraction of power in the 2D versus slab component. Our results confirm that the 2D plus slab model is consistent with the data and the power ratio between 2D and slab components depends on radial distance, with the relative power in 2D fluctuations becoming smaller closer to the Sun.
Turbulence and Particle Acceleration in a Relativistic Plasma
Authors: Vega Cristian , Boldyrev Stanislav , Roytershteyn Vadim , Medvedev Mikhail
Published: January 2022

In a collisionless plasma, the energy distribution function of plasma particles can be strongly affected by turbulence. In particular, it can develop a nonthermal power-law tail at high energies. We argue that turbulence with initially relativistically strong magnetic perturbations (magnetization parameter σ ≫ 1) quickly evolves into a state with ultrarelativistic plasma temperature but mildly relativistic turbulent fluctuations. We present a phenomenological and numerical study suggesting that in this case, the exponent α in the power-law particle-energy distribution function, f(γ)d
γ ∝ γ
−α

d
γ, depends on magnetic compressibility of turbulence. Our analytic prediction for the scaling exponent α is in good agreement with the numerical results.
Deep XMM-Newton Observations of an X-ray Weak Broad Absorption Line Quasar at z = 6.5
Authors: Yang Jinyi , Fan Xiaohui , Wang Feige , Lanzuisi Giorgio , Nanni Riccardo , Cappi Massimo , Chartas George , Dadina Mauro , Decarli Roberto , Jin Xiangyu , Keeton Charles R. , Venemans Bram P. , Walter Fabian , Wang Ran , Wu Xue-Bing , Yue Minghao , Zabludoff Ann
Published: January 2022

We report X-ray observations of the most distant known gravitationally lensed quasar, J0439+1634 at z = 6.52, which is also a broad absorption line (BAL) quasar, using the XMM-Newton Observatory. With a 130 ks exposure, the quasar is significantly detected as a point source at the optical position with a total of

358

−
19

+
19

net counts using the EPIC instrument. By fitting a power law plus Galactic absorption model to the observed spectra, we obtain a spectral slope of

Γ
=

1.45

−
0.09

+
0.10

. The derived optical-to-X-ray spectral slope α
ox is

−

2.07

−
0.01

+
0.01

, suggesting that the X-ray emission of J0439+1634 is weaker by a factor of 18 than the expectation based on its 2500 Å luminosity and the average α
ox versus luminosity relationship. This is the first time that an X-ray weak BAL quasar at z > 6 has been observed spectroscopically. Its X-ray weakness is consistent with the properties of BAL quasars at lower redshift. By fitting a model including an intrinsic absorption component, we obtain intrinsic column densities of

N

H

=

2.8

−
0.6

+
0.7

×

10

23

cm

−
2

and

N

H

=

4.3

−
1.5

+
1.8

×

10

23

cm

−
2

, assuming a fixed Γ of 1.9 and a free Γ, respectively. The intrinsic rest-frame 2–10 keV luminosity is derived as (9.4–15.1) × 1043 erg s−1, after correcting for lensing magnification (μ = 51.3). The absorbed power-law model fitting indicates that J0439+1634 is the highest redshift obscured quasar with a direct measurement of the absorbing column density. The intrinsic high column density absorption can reduce the X-ray luminosity by a factor of 3–7, which also indicates that this quasar could be a candidate intrinsically X-ray weak quasar.
The Three-dimensional Collapse of a Rapidly Rotating 16 M
⊙ Star
Authors: Fields C. E.
Published: January 2022

I report on the three-dimensional (3D) hydrodynamic evolution of a rapidly rotating 16 M
⊙ star to iron core collapse. For the first time, I follow the 3D evolution of the angular momentum (AM) distribution in the iron core and convective shell burning regions for the final 10 minutes up to and including gravitational instability and core collapse. In 3D, convective regions show efficient AM transport that leads to an AM profile that differs in shape and magnitude from MESA within a few shell convective turnover timescales. For different progenitor models, such as those with tightly coupled Si/O convective shells, efficient AM transport in 3D simulations could lead to a significantly different AM distribution in the stellar interior affecting estimates of the natal neutron star or black hole spin. The results suggest that 3D AM transport in convective and rotating shell burning regions are critical components in models of massive stars and could qualitatively alter the explosion outcome and inferred compact remnant properties.
Black Hole Flares: Ejection of Accreted Magnetic Flux through 3D Plasmoid-mediated Reconnection
Authors: Ripperda B. , Liska M. , Chatterjee K. , Musoke G. , Philippov A. A. , Markoff S. B. , Tchekhovskoy A. , Younsi Z.
Published: January 2022

Magnetic reconnection can power bright, rapid flares originating from the inner magnetosphere of accreting black holes. We conduct extremely high-resolution (5376 × 2304 × 2304 cells) general-relativistic magnetohydrodynamics simulations, capturing plasmoid-mediated reconnection in a 3D magnetically arrested disk for the first time. We show that an equatorial, plasmoid-unstable current sheet forms in a transient, nonaxisymmetric, low-density magnetosphere within the inner few Schwarzschild radii. Magnetic flux bundles escape from the event horizon through reconnection at the universal plasmoid-mediated rate in this current sheet. The reconnection feeds on the highly magnetized plasma in the jets and heats the plasma that ends up trapped in flux bundles to temperatures proportional to the jet’s magnetization. The escaped flux bundles can complete a full orbit as low-density hot spots, consistent with Sgr A* observations by the GRAVITY interferometer. Reconnection near the horizon produces sufficiently energetic plasma to explain flares from accreting black holes, such as the TeV emission observed from M87. The drop in the mass accretion rate during the flare and the resulting low-density magnetosphere make it easier for very-high-energy photons produced by reconnection-accelerated particles to escape. The extreme-resolution results in a converged plasmoid-mediated reconnection rate that directly determines the timescales and properties of the flare.
The Rate, Amplitude, and Duration of Outbursts from Class 0 Protostars in Orion
Authors: Zakri Wafa , Megeath S. T. , Fischer William J. , Gutermuth Robert , Furlan Elise , Hartmann Lee , Karnath Nicole , Osorio Mayra , Safron Emily , Stanke Thomas , Stutz Amelia M. , Tobin John J. , Allen Thomas S. , Federman Sam , Habel Nolan , Manoj P. , Narang Mayank , Pokhrel Riwaj , Rebull Luisa , Sheehan Patrick D. , Watson Dan M.
Published: January 2022

At least half of a protostar’s mass is accreted in the Class 0 phase, when the central protostar is deeply embedded in a dense, infalling envelope. We present the first systematic search for outbursts from Class 0 protostars in the Orion clouds. Using photometry from Spitzer/IRAC spanning 2004 to 2017, we detect three outbursts from Class 0 protostars with ≥2 mag changes at 3.6 or 4.5 μm. This is comparable to the magnitude change of a known protostellar FU Ori outburst. Two are newly detected bursts from the protostars HOPS 12 and 124. The number of detections implies that Class 0 protostars burst every 438 yr, with a 95% confidence interval of 161 to 1884 yr. Combining Spitzer and WISE/NEOWISE data spanning 2004–2019, we show that the bursts persist for more than nine years with significant variability during each burst. Finally, we use 19–100 μm photometry from SOFIA, Spitzer, and Herschel to measure the amplitudes of the bursts. Based on the burst interval, a duration of 15 yr, and the range of observed amplitudes, 3%–100% of the mass accretion during the Class 0 phase occurs during bursts. In total, we show that bursts from Class 0 protostars are as frequent, or even more frequent, than those from more evolved protostars. This is consistent with bursts being driven by instabilities in disks triggered by rapid mass infall. Furthermore, we find that bursts may be a significant, if not dominant, mode of mass accretion during the Class 0 phase.
The Historic K

s
Light Curve of the FUor PGIR20dci
Authors: Hodapp Klaus W. , Dahm Scott E. , Varricatt Watson P.
Published: January 2022

We report a historic K

s
-band light curve spanning over three decades of the FUor PGIR20dci recently discovered by Hillenbrand et al. We find some minor variability of the object prior to the FUor outburst, an initial rather slow rise in brightness, followed in 2019 by a much steeper rise to the maximum.
Spectroscopic Analysis of Star-forming Regions in the Spiral Galaxy NGC 628
Authors: Gorantiwar Atharva , Skillman Evan , Rogers Noah
Published: January 2022

NGC 628 is one of many spiral galaxies that has been observed and analyzed to determine the chemical composition. Since there have been improvements in the methods of analysis recently, this paper finds new values for the electron temperatures within this galaxy. Additionally, it brings up a previously unnoticed iron line contamination problem that has affected the [O iii] temperatures and fluxes. Temperature results are compared against, the most recent chemical analysis of the same galaxy.
Resolving the Multiplicity of Exoplanet Host Stars in Gemini/NIRI Data
Authors: Miskovetz Kim , Dupuy Trent J. , Schonhut-Stasik Jessica , Stassun Keivan G.
Published: January 2022

The majority of stars have one or more stellar companions. As exoplanets continue to be discovered, it is crucial to examine planetary systems to identify their stellar companions. By observing a change in proper motion, companions can be detected by the acceleration they induce on their host stars. We selected 701 stars from the Hipparcos–Gaia Catalog of Accelerations (HGCA) that have existing adaptive optics imaging data gathered with Gemini/Near InfraRed Imager (NIRI). Of these, we examined 21 stars known to host planet candidates and reduced their archival NIRI data with Gemini’s DRAGONS software. We assessed these systems for companions using the NIRI images as well as Renormalized Unit Weight Error values in Gaia and accelerations in the HGCA. We detected three known visible companions and found two more systems with no visible companions but astrometric measurements indicating likely unresolved companions.
Local-time Dependence of Chemical Species in the Venusian Mesosphere
Authors: Shao Wencheng D. , Zhang Xi , Mendonça João , Encrenaz Thérèse
Published: January 2022

Observed chemical species in the Venusian mesosphere show local-time variabilities. SO2 at the cloud top exhibits two local maxima over local time, H2O at the cloud top is uniformly distributed, and CO in the upper atmosphere shows a statistical difference between the two terminators. In this study, we investigated these local-time variabilities using a three-dimensional (3D) general circulation model (GCM) in combination with a two-dimensional (2D) chemical transport model (CTM). Our simulation results agree with the observed local-time patterns of SO2, H2O, and CO. The two-maximum pattern of SO2 at the cloud top is caused by the superposition of the semidiurnal thermal tide and the retrograde superrotating zonal (RSZ) flow. SO2 above 85 km shows a large day–night difference resulting from both photochemistry and the subsolar-to-antisolar (SS-AS) circulation. The transition from the RSZ flows to SS-AS circulation can explain the CO difference between two terminators and the displacement of the CO local-time maximum with respect to the antisolar point. H2O is long-lived and exhibits very uniform distribution over space. We also present the local-time variations of HCl, ClO, OCS, and SO simulated by our model and compare to the sparse observations of these species. This study highlights the importance of multidimensional CTMs for understanding the interaction between chemistry and dynamics in the Venusian mesosphere.
Modeling the Lunar Wake Response to a CME Using a Hybrid PIC Model
Authors: Rasca Anthony P. , Fatemi Shahab , Farrell William M.
Published: January 2022

In the solar wind, a low-density wake region forms downstream of the nightside lunar surface. In this study, we use a series of 3D hybrid particle-in-cell simulations to model the response of the lunar wake to a passing coronal mass ejection (CME). Average plasma parameters are derived from the Wind spacecraft located at 1 au during three distinct phases of a passing halo (Earth-directed) CME on 2015 June 22. Each set of plasma parameters, representing the shock/plasma sheath, a magnetic cloud, and plasma conditions we call the mid-CME phase, are used as the time-static upstream boundary conditions for three separate simulations. These simulation results are then compared with results that use nominal solar wind conditions. Results show a shortened plasma void compared to nominal conditions and a distinctive rarefaction cone originating from the terminator during the CME’s plasma sheath phase, while a highly elongated plasma void reforms during the magnetic cloud and mid-CME phases. Developments of electric and magnetic field intensification are also observed during the plasma sheath phase along the central wake, while electrostatic turbulence dominates along the plasma void boundaries and 2–3 lunar radii R

M
downstream in the central wake during the magnetic cloud and mid-CME phases. The simulations demonstrate that the lunar wake responds in a dynamic way with the changes in the upstream solar wind during a CME.
A new catfish of the genus Trichomycterus from the Rio Paraíba do Sul Basin, south-eastern Brazil, a supposedly migrating species (Siluriformes, Trichomycteridae)
Authors: Costa Wilson J. E. M. , Katz Axel M.
Published: January 2022

A new species of the catfish genusTrichomycterusis described from the Rio Paraíba do Sul, south-eastern Brazil. This species exhibits some morphological character states that are unique amongst congeners, including a robust opercle and a long interopercle with numerous odontodes (50–60 opercular and 90–100 interopercular), a black bar on the basal portion of the caudal fin and a dark brown flank with a well delimited dorsal yellow stripe. It also exhibits some morphological traits that are uncommon amongst congeners, such as the presence of nine pectoral-fin rays. The presence of a shallow hyomandibular outgrowth and a ventrally expanded pre-opercular ventral flap suggests that this species is closely related toT. melanopygius,T. pradensisandT. tete. The new species also differs fromT. melanopygius,T. pradensisandT. teteby having an emarginate caudal fin and a single median supra-orbital pore S6. Anecdotal evidence suggests thatT. largoperculatusandT. pradensishave migratory habits, a condition not previously reported for eastern South American trichomycterines.
L’engagement enseignant des soixante-huitards
Authors: Mathieu Lilian
Published: January 2022

Fondé sur l’analyse d’une quarantaine d’entretiens biographiques, l’article étudie comment la participation de militants et militantes d’extrême gauche à Mai 68 et aux luttes qui ont suivi a façonné leur entrée dans les métiers de l’enseignement. Il montre comment cette orientation professionnelle a été l’aboutissement d’une mobilité sociale ascendante réalisée par et dans l’école, mais qu’elle a aussi été largement influencée par leur expérience de la contestation collective. Le militantisme joue en effet un rôle en apparence paradoxal dans les trajectoires tant politiques que professionnelles des enquêtés : si bon nombre ont tout d’abord interrompu leurs études (et renoncé aux promesses d’ascension sociale qu’elles leur offraient) au profit de leur militantisme, celui-ci les a dotés en compétences et connaissances qu’ils ont pu ultérieurement mobiliser pour exercer leur métier d’enseignant.
L’expérience comme ressource alternative pour des femmes des classes populaires ?
Authors: Arborio Anne-Marie
Published: January 2022

L’expérience de travail offre-t-elle des ressources compensatoires d’un défaut en divers états ou formes de capital culturel ? Une enquête ethnographique menée autour du dispositif de validation des acquis de l’expérience (VAE) pour le diplôme d’aide-soignante permet d’aborder cette question pour les femmes des classes populaires qui aspirent à une petite mobilité après avoir travaillé auprès de malades ou de personnes âgées, en institution ou à domicile, sur des emplois pour lesquels elles ont été recrutées sans autre exigence que leurs dispositions genrées à s’occuper d’autrui. L’étude de leurs parcours montre que la VAE constitue une aubaine pour contourner les difficultés de la formation mais nombre de candidates restent à l’écart de la réussite ou n’y accèdent qu’après des tentatives répétées. La forme et le contenu des épreuves, dont les références scolaires ne sont pas absentes, semblent pénaliser les candidates les plus éloignées de l’école : l’expérience est difficilement mobilisable sans des ressources culturelles et sociales, liées au parcours singulier ou alimentées par l’établissement. Les épreuves révèlent aussi la fragilité de l’expérience de travail même : les conditions de travail et les rapports de force au travail, dans les emplois subalternes, ne font pas toujours de cette expérience une occasion d’accumuler les compétences attendues pour espérer une petite mobilité.
Les neurosciences non sociales ?
Authors: Lignier Wilfried
Published: January 2022

Les sciences sociales, en particulier celles qui donnent de l’importance à l’idée d’incorporation des dispositions, s’intéressent de plus en plus aux sciences du cerveau. Elles se réfèrent alors volontiers aux travaux de neurosciences dites « sociales », mais souvent de façon générale et abstraite. A contrario, il est possible de réfléchir aux rapports entre sciences sociales et sciences neurales en partant de l’observation directe, ethnographique, d’opérations de recherche précises – en l’espèce, d’une expérience par électroencéphalogramme, concernant les dispositions individuelles à la violence politique. Une telle observation, réalisée au sein d’un laboratoire étasunien reconnu, montre comment la socialité des comportements humains est évacuée dans la pratique habituelle des neurosciences sociales. La différenciation sociale des sujets de l’expérience, les interactions interpersonnelles qui conditionnent le cerveau, et le caractère institutionnel et historique des représentations s’avèrent impensés, parfois jusqu’à l’absurde (création de stimuli étranges). L’article invite, de façon constructive, à une meilleure prise en compte de ces spécificités épistémologiques, théoriques et méthodologiques, qui pourraient être dépassées si et seulement si les sciences sociales assument leur contribution scientifique distinctive dans les rapports interdisciplinaires.
Carte blanche à André Rauch
Authors: Fuchs Julien , Midol Nancy , Bui-Xuân Gilles
Published: January 2022

Pour son 40 e  anniversaire, la revue STAPS a souhaité donner la parole à un acteur clé de la revue, et plus largement du champ des Sciences et Techniques des Activités Physiques et Sportives (STAPS). André Rauch, ancien président de l’Association pour le développement des connaissances relatives aux activités physiques et sportives (ancêtre de l’AFRAPS), ancien président de la 74 e  section du CNU STAPS, a accepté de se prêter au jeu. L’entretien aborde notamment les origines de la revue et la structuration du champ des STAPS au début des années 1980. Il offre aussi la possibilité à André Rauch de s’exprimer sur ses recherches ainsi que sur sa manière de voir l’espace universitaire aujourd’hui.
A novel attention model for salient structure detection in seismic volumes
Authors: Shafiq Muhammad Amir ,   Apple Inc., Cupertino, CA, USA, Long Zhiling , Di Haibin , AlRegib Ghassan ,   Mercer University, Atlanta, GA, USA,   Schlumberger Ltd., Houston, TX, USA,   Georgia Institute of Technology, Atlanta, GA, USA
Published: January 2022

A new approach to seismic interpretation is proposed to leverage visual perception and human visual system modeling. Specifically, a saliency detection algorithm based on a novel attention model is proposed for identifying subsurface structures within seismic data volumes. The algorithm employs 3D-FFT and a multi-dimensional spectral projection, which decomposes local spectra into three distinct components, each depicting variations along different dimensions of the data. Subsequently, a novel directional center-surround attention model is proposed to incorporate directional comparisons around each voxel for saliency detection within each projected dimension. Next, the resulting saliency maps along each dimension are combined adaptively to yield a consolidated saliency map, which highlights various structures characterized by subtle variations and relative motion with respect to their neighboring sections. A priori information about the seismic data can be either embedded into the proposed attention model in the directional comparisons, or incorporated into the algorithm by specifying a template when combining saliency maps adaptively. Experimental results on two real seismic datasets from the North Sea, Netherlands and Great South Basin, New Zealand demonstrate the effectiveness of the proposed algorithm for detecting salient seismic structures of different natures and appearances in one shot, which differs significantly from traditional seismic interpretation algorithms. The results further demonstrate that the proposed method outperforms comparable state-of-the-art saliency detection algorithms for natural images and videos, which are inadequate for seismic imaging data.
Crop and weed classification based on AutoML
Authors: Jiang Xuetao ,   School of Information Science and Engineering, Lanzhou University, Lanzhou, 730000, China, Yong Binbin , Garshasbi Soheila , Shen Jun , Jiang Meiyu , Zhou Qingguo ,   School of Computing and Information Technology, University of Wollongong, NSW 2522, Australia
Published: January 2022

CNN models already play an important role in classification of crop and weed with high accuracy, more than 95% as reported in literature. However, to manually choose and fine-tune the deep learning models becomes laborious and indispensable in most traditional practices and research. Moreover, the classic objective functions are not thoroughly compatible with agricultural farming tasks as the corresponding models suffer from misclassifying crop to weed, often more likely than in other deep learning application domains. In this paper, we applied autonomous machine learning with a new objective function for crop and weed classification, achieving higher accuracy and lower crop killing rate (rate of identifying a crop as a weed). The experimental results show that our method outperforms state-of-the-art applications, for example, ResNet and VGG19.
An analysis of two degenerate double-Hopf bifurcations
Authors: Moza Gheorghe , Sterpu Mihaela , Rocşoreanu Carmen
Published: January 2022

The generic double-Hopf bifurcation is presented in detail in literature in textbooks like references. In this paper we complete the study of the double-Hopf bifurcation with two degenerate (or nongeneric) cases. In each case one of the generic conditions is not satisfied. The normal form and the corresponding bifurcation diagrams in each case are obtained. New possibilities of behavior which do not appear in the generic case were found.
Optimization of machining parameters in drilling hybrid sisal-cotton fiber reinforced polyester composites
Authors: Mohammed Nurhusien Hassen ,   Addis Ababa Institute of Technology, Addis Ababa University, Addis Ababa, Ethiopia, Wolla Desalegn Wogaso
Published: January 2022

Machining natural fiber reinforced polymer composite materials is one of most challenging tasks due to the material's anisotropic property, non-homogeneous structure and abrasive nature of fibers. Commonly, conventional machining of composites leads to delamination, inter-laminar cracks, fiber pull out, poor surface finish and wear of cutting tool. However, these challenges can be significantly reduced by using proper machining conditions. Thus, this research aims at optimizing machining parameters in drilling hybrid sisal-cotton fibers reinforced polyester composite for better machining performance characteristics namely better hole roundness accuracy and surface finish using Taguchi method. The effect of machining parameters including spindle speed, feed rate and drill diameter on drill hole accuracy (roundness error) and surface-roughness of the hybrid composite are evaluated. Series of experiments based on Taguchi's L16 orthogonal array were performed using different ranges of machining parameters namely spindle speed (600,900, 1200, 1600 rpm), feed rate (10, 15, 20, 25 mm/min) and drill diameter (6, 7, 8, 10 mm). Hole roundness error and surface-roughness are determined using ABC digital caliper and Zeta 20 profilometer, respectively. Optimum machining condition for drilling hybrid composite material (speed: 1600 rpm, feed rate: 25 mm/min and drill diameter: 6 mm) is determined, and the results are verified by conducting confirmation test which proves that the results are reliable.
Fractal fractional derivative on chemistry kinetics hires problem
Authors: Aslam Muhammad ,   Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, Department of Chemistry and Materials Science, Northwest University, Xi'an 710127, China, Farman Muhammad , Ahmad Hijaz , Gia Tuan Nguyen , Ahmad Aqeel , Askar Sameh ,   Department of Mathematics and Statistics, University of Lahore, Lahore 54590, Pakistan,   Section of Mathematics, International Telematic University Uninettuno, Corso Vittorio Emanuele Ⅱ, 39, 00186 Roma, Italy,   Mathematics in Applied Sciences and Engineering Research Group, Scientific Research Center, Al-Ayen University, Nasiriyah 64001, Iraq,   Department of Computing, University of Turku, 20500, Turku, Finland,   Department of Statistics and Operations Research, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia
Published: January 2022

In this work, we construct the fractional order model for chemical kinetics issues utilizing novel fractal operators such as fractal fractional by using generalized Mittag-Leffler Kernel. To overcome the constraints of the traditional Riemann-Liouville and Caputo fractional derivatives, a novel notion of fractional differentiation with non-local and non-singular kernels was recently presented. Many scientific conclusions are presented in the study, and these results are supported by effective numerical results. These findings are critical for solving the nonlinear models in chemical kinetics. These concepts are very important to use for real life problems like brine tank cascade, recycled brine tank cascade, pond pollution, home heating and biomass transfer problem. Many scientific results are presented in the paper also prove these results by effective numerical results. These results are very important for solving the nonlinear model in chemistry kinetics which will be helpful to understand the chemical reactions and its actual behavior; also the observation can be developed for future kinematic chemical reactions with the help of these results.
Remarks on the $ K_2 $ group of $ \mathbb{Z}[\zeta_p] $
Authors: Zhang Daochang ,   College of Sciences, Northeast Electric Power University, Jilin 132012, China, Sun Chaochao ,   School of Mathematics and Statistics, Linyi University, Linyi 276005, China
Published: January 2022

In this paper, our aim is to obtain the $ K_2 $ analogues of both the Herbrand-Ribet theorem and the Vandiver's conjecture.
Calibration and prediction for the inexact SIR model
Authors: Wang Yan ,   School of Statistics and Data Science, Beijing University of Technology, Beijing 100124, China, Lu Guichen , Du Jiang ,   School of Science, Chongqing University of Technology, Chongqing 400054, China
Published: January 2022

A Susceptible Infective Recovered (SIR) model is usually unable to mimic the actual epidemiological system exactly. The reasons for this inaccuracy include observation errors and model discrepancies due to assumptions and simplifications made by the SIR model. Hence, this work proposes calibration and prediction methods for the SIR model with a one-time reported number of infected cases. Given that the observation errors of the reported data are assumed to be heteroscedastic, we propose two predictors to predict the actual epidemiological system by modeling the model discrepancy through a Gaussian Process model. One is the calibrated SIR model, and the other one is the discrepancy-corrected predictor, which integrates the calibrated SIR model with the Gaussian Process predictor to solve the model discrepancy. A wild bootstrap method quantifies the two predictors' uncertainty, while two numerical studies assess the performance of the proposed method. The numerical results show that, the proposed predictors outperform the existing ones and the prediction accuracy of the discrepancy-corrected predictor is improved by at least $ 49.95\% $.
A mathematical investigation of an "SVEIR" epidemic model for the measles transmission
Authors: Hajji Miled El ,   Department of Mathematics, Faculty of Science, University of Jeddah, P.O. Box 80327, Jeddah 21589, Saudi Arabia, Albargi Amer Hassan ,   Department of Mathematics, Faculty of Science, King Abdulaziz University, P.O. Box 80327, Jeddah 21589, Saudi Arabia
Published: January 2022

A generalized "SVEIR" epidemic model with general nonlinear incidence rate has been proposed as a candidate model for measles virus dynamics. The basic reproduction number $ \mathcal{R} $, an important epidemiologic index, was calculated using the next generation matrix method. The existence and uniqueness of the steady states, namely, disease-free equilibrium ($ \mathcal{E}_0 $) and endemic equilibrium ($ \mathcal{E}_1 $) was studied. Therefore, the local and global stability analysis are carried out. It is proved that $ \mathcal{E}_0 $ is locally asymptotically stable once $ \mathcal{R} $ is less than. However, if $ \mathcal{R} > 1 $ then $ \mathcal{E}_0 $ is unstable. We proved also that $ \mathcal{E}_1 $ is locally asymptotically stable once $ \mathcal{R} > 1 $. The global stability of both equilibrium $ \mathcal{E}_0 $ and $ \mathcal{E}_1 $ is discussed where we proved that $ \mathcal{E}_0 $ is globally asymptotically stable once $ \mathcal{R}\leq 1 $, and $ \mathcal{E}_1 $ is globally asymptotically stable once $ \mathcal{R} > 1 $. The sensitivity analysis of the basic reproduction number $ \mathcal{R} $ with respect to the model parameters is carried out. In a second step, a vaccination strategy related to this model will be considered to optimise the infected and exposed individuals. We formulated a nonlinear optimal control problem and the existence, uniqueness and the characterisation of the optimal solution was discussed. An algorithm inspired from the Gauss-Seidel method was used to resolve the optimal control problem. Some numerical tests was given confirming the obtained theoretical results.
Two-weight and three-weight linear codes constructed from Weil sums
Authors: Zhang Tonghui , Lu Hong , Yang Shudi
Published: January 2022

Linear codes with few weights are widely used in strongly regular graphs, secret sharing schemes, association schemes and authentication codes. In this paper, we construct several two-weight and three-weight linear codes over finite fields by choosing suitable different defining sets. We also give some examples and some of the codes are optimal or almost optimal. Their applications to secret sharing schemes are also investigated.
General time interval multidimensional BSDEs with generators satisfying a weak stochastic-monotonicity condition
Authors: Li Tingting , Xu Ziheng , Fan Shengjun
Published: January 2022

This paper establishes an existence and uniqueness result for the adapted solution of a general time interval multidimensional backward stochastic differential equation (BSDE), where the generator  \begin{document}$ g $\end{document}  satisfies a weak stochastic-monotonicity condition and a general growth condition in the state variable  \begin{document}$ y $\end{document} , and a stochastic-Lipschitz condition in the state variable  \begin{document}$ z $\end{document} . This unifies and strengthens some known works. In order to prove this result, we develop some ideas and techniques employed in Xiao and Fan [25] and Liu et al. [15]. In particular, we put forward and prove a stochastic Gronwall-type inequality and a stochastic Bihari-type inequality, which generalize the classical ones and may be useful in other applications. The martingale representation theorem, Itô’s formula, and the BMO martingale tool are used to prove these two inequalities.
Extended conditional G-expectations and related stopping times
Authors: Hu Mingshang , Peng Shige
Published: January 2022

In this paper, we extend the definition of conditional  \begin{document}$ G{\text{-}}{\rm{expectation}} $\end{document}  to a larger space on which the dynamical consistency still holds. We can consistently define, by taking the limit, the conditional  \begin{document}$ G{\text{-}}{\rm{expectation}} $\end{document}  for each random variable  \begin{document}$ X $\end{document} , which is the downward limit (respectively, upward limit) of a monotone sequence  \begin{document}$ \{X_{i}\} $\end{document}  in  \begin{document}$ L_{G}^{1}(\Omega) $\end{document} . To accomplish this procedure, some careful analysis is needed. Moreover, we present a suitable definition of stopping times and obtain the optional stopping theorem. We also provide some basic and interesting properties for the extended conditional  \begin{document}$ G{\text{-}}{\rm{expectation}} $\end{document} .
Computational studies on physico-chemical properties in the quality analysis of corn and peanut oil
Authors: Rubalya Valantina S. , Arockia Jayalatha K.
Published: January 2022

Oils are commonly used in cooking as a frying medium which has been constantly subjected to different levels of heating. In this work, we have considered the most commonly used oils namely peanut oil and corn oil. Quality analyses of corn and peanut oils were made by relating macroscopic properties (ultrasonic velocity, viscosity, and density) to microscopic parameters (intermolecular free length, adiabatic compressibility etc.,) by subjecting them to six cycles of heating (190 ˚C). Variation in the mentioned property indexes, the degree of degradation and reusability for the next heating cycle that could be used in the food industry and processing were monitored. Using Newton-Laplace and Wood’s equation, the adiabatic compressibility, acoustic impedance, and intermolecular free length of the oil were estimated from the experimental data. Ultrasonic velocity was observed linearly as related to viscosity with the dependency factor (R2 = 0.932). With the aid of experiential data, the physical thermodynamic parameters, particularly particle size, packing factor, chemical potential, and L-J potential were computed. A high correlation factor was observed by fitting ultrasonic velocity, viscosity, and density to Parthasarathy and Bakshi, and Rodenbush equations. In the study, ultrasonic velocity, a macroscopic parameter, could be decoded to determine the microscopic variations in oil subjected to different temperatures in an industrial application.
Assessment of the Endorsers of E-Business Practices for Food Supply Chain Performance Systems
Authors: Sharma Janpriy , Tyagi Mohit
Published: January 2022

Globalisation and changing lifestyle of the people has escalated the demand for the more product customisation, taste preferences and awareness about the usage of quality food commodities. Recent developments in the field of information technology and its integration with the business practices has emerged as a new term named ‘e-business’ (EB). Increasing consumer base of the food supply chains (FSC), has escalated the demand of technological and operation advancements by mediating ‘EB’ activities. Such, practices become extensively crucial when the world is suffering from the pandemic of COVID-19, leading to distressing of FSC linkages causing frequent market closures. To tackle the same presented work, explores the various endorsers (EDR) of the ‘EB’ in FSC, which are contemplated by hybrid combination of multi-criteria decision making techniques. Outcomes of the present work aids managers to formulate the decision policies and develop a robust framework in the direction to cling the ‘EB’ practices with FSC.
Blockchain Adoption for Provenance and Traceability in the Retail Food Supply Chain
Authors: Kumar Nishant , Upreti Kamal , Mohan Divya
Published: January 2022

Blockchain has evolved as one of the disruptive technologies in the landscape of business. The study aims to investigate drivers of consumer adoption of blockchain for product origin and track to trace history before making a purchase. An extended technology adoption model (TAM) has been proposed to examine the consumer perspective for blockchain adoption in the food supply chain. Based on the survey of 208 retail consumers the proposed model was validated using variance-based structure equation modeling. Findings of the study emphasize the significant role of perceived security and privacy in developing trust, ease of use, and usefulness of blockchain-enabled systems. The relationship between perceived ease of use and attitude is mediated through perceived usefulness. The strong influence of attitude on adoption intention represents the consumer interest for blockchain to understand the product provenance. Study provides vital insights for successful blockchain implementation to enhance supply chain effectiveness.
Fundamental Aspects of Vedic Sciences by Yajna Vijnan and Mantra Therapy
Authors: Rastogi Rohit , Saxena Mamta , Chaturvedi Devendra Kumar , Sagar Sheelu , Tandon Neeti , Rajeshwari T. , Singh Bhavna
Published: January 2022

The Present manuscript discusses on various scientific aspects of Indian Vedic Agnihotra Vijnan and Mantra therapy. It has been scientifically proven in many recent experiemnts and literature that Homa therapy is much effective in inviting rainy clouds, efficient in disesaes control through inhaling therapy, generates negative ions responsible for happiness, organic homa krishi (farming) is best for humans, boon for mental and physical fitness. The authors’ team have tried best to present a series of small experiemnts in support of few of above results and confident enough that gradually this therapy is poular and being accepted globally by one and all. Indian culture and science is scientific and full of components to uplift the human conciousness and ease in life. The present study supports this fact by visualizations and sensor based experiemnts. In 21st century, it is crucial to accept with open minded the good features of this alternate therapy in view of second and third and multiple waves of pandemic caused by sars-cov’19 and other global threats.
Face Recognition Through Multi-Resolution Images
Authors: Mliki Hazar , Fendri Emna , Chebil Ahmed
Published: January 2022

In this paper, we introduce a new method for face recognition in multi-resolution images. The proposed method is composed of two phases: an off-line phase and an inference phase. In the off-line phase, we built the Kernel Partial Least Squares (KPLS) regression model to map the LR facial features to HR ones. The KPLS predictor was then used in the inference phase to map HR features from LR features. We applied in both phases the Block-Based Discrete Cosine Transform (BBDCT) descriptor to enhance the facial feature description. Finally, the identity matching was carried out with the K-Nearest Neighbor (KNN) classifier. Experimental study was conducted on the AR and ORL databases and the obtained results proved the efficiency of the proposed method to deal with LR and VLR face recognition problem.
Hybrid Representation to Locate Vulnerable Lines of Code
Authors: Zagane Mohammed , Alenezi Mamdouh , Abdi Mustapha Kamel
Published: January 2022

Locating vulnerable lines of code in large software systems needs huge efforts from human experts. This explains the high costs in terms of budget and time needed to correct vulnerabilities. To minimize these costs, automatic solutions of vulnerabilities prediction have been proposed. Existing machine learning (ML)-based solutions face difficulties in predicting vulnerabilities in coarse granularity and in defining suitable code features that limit their effectiveness. To addressee these limitations, in the present work, the authors propose an improved ML-based approach using slice-based code representation and the technique of TF-IDF to automatically extract effective features. The obtained results showed that combining these two techniques with ML techniques allows building effective vulnerability prediction models (VPMs) that locate vulnerabilities in a finer granularity and with excellent performances (high precision (>98%), low FNR (<2%) and low FPR (<3%) which outperforms software metrics and are equivalent to the best performing recent deep learning-based approaches.
Assistive Technology-Based Solution for Hearing Impairment Using Smartphones
Authors: Mehra Vasu , Pandey Dhiraj
Published: January 2022

Developing a system for sign language recognition becomes essential for the deaf as well as a mute person. The recognition system acts as a translator between a disabled and an able person. This eliminates the hindrances in the exchange of ideas. Most of the existing systems are very poorly designed with limited support for the needs of their day to day facilities. The proposed system embedded with gesture recognition capability has been introduced here which extracts signs from a video sequence and displays them on screen. On the other hand, a speech to text as well as text to speech system is also introduced to further facilitate the grieved people. To get the best out of a human-computer relationship, the proposed solution consists of various cutting-edge technologies and Machine Learning based sign recognition models that have been trained by using TensorFlow and Keras library. The proposed architecture works better than several gesture recognition techniques like background elimination and conversion to HSV