bluuebunny/crossref_metadata_2025 huggingface dataset:
DIAGNOSTIC MODEL OF HELICOPTER TURBOSHAFT ENGINE
Authors:   Samara National Research University named after Academician S.P. Korolev, Kazhaev V.P. , Kiselev D.Y. ,   Samara National Research University named after Academician S.P. Korolev, Kiselev Y.V. ,   Samara National Research University named after Academician S.P. Korolev
Published: April 2023

The article presents a qualitative assessment of the impact on the engine components characteristics of the malfunction occurrence in the flow part of the aviation gas turbine engines, which lead to changes in its geometry. Using the example of a compressor, it is shown that when defects appear in it, two of its characteristics are deformed: efficiency and pressure characteristics (which is confirmed by a significant number of studies). It is concluded that in order to reliably diagnose aviation gas turbine engines by thermogasodynamic parameters, the mathematical model must take into account the change in two characteristics for each engine component of the flow part (and not only the change in the characteristics of the efficiency of the nodes). A linear mathematical model of a helicopter turboshaft turbine engine is presented and the results of calculating the influence coefficient for a given control law are presented. The peculiarity of the presented model is that the state of each engine component is characterized by two state parameters: for compressors, this is the head characteristic and the efficiency characteristic, for turbines, performance characteristics and efficiency.
Beyond MHC binding: immunogenicity prediction tools to refine neoantigen selection in cancer patients
Authors: Carri Ibel , Schwab Erika , Podaza Enrique , Garcia Alvarez Heli M. , Mordoh José , Nielsen Morten , Barrio María Marcela
Published: April 2023

In the last years, multiple efforts have been made to accurately predict neoantigens derived from somatic mutations in cancer patients, either to develop personalized therapeutic vaccines or to study immune responses after cancer immunotherapy. In this context, the increasing accessibility of paired whole-exome sequencing (WES) of tumor biopsies and matched normal tissue as well as RNA sequencing (RNA-Seq) has provided a basis for the development of bioinformatics tools that predict and prioritize neoantigen candidates. Most pipelines rely on the binding prediction of candidate peptides to the patient’s major histocompatibility complex (MHC), but these methods return a high number of false positives since they lack information related to other features that influence T cell responses to neoantigens. This review explores available computational methods that incorporate information on T cell preferences to predict their activation after encountering a peptide-MHC complex. Specifically, methods that predict i) biological features that may increase the availability of a neopeptide to be exposed to the immune system, ii) metrics of self-similarity representing the chances of a neoantigen to break immune tolerance, iii) pathogen immunogenicity, and iv) tumor immunogenicity. Also, this review describes the characteristics of these tools and addresses their performance in the context of a novel benchmark dataset of experimentally validated neoantigens from patients treated with a melanoma vaccine (VACCIMEL) in a phase II clinical study. The overall results of the evaluation indicate that current tools have a limited ability to predict the activation of a cytotoxic response against neoantigens. Based on this result, the limitations that make this problem an unsolved challenge in immunoinformatics are discussed.
A potent bioactive fraction against colon cancer from Plectranthus vettiveroides
Authors: Athikkavil Faisal M. , Aiswarya Sreekumar U. , Johny Remya , Sudhesh Meghna , Nisthul Amrutha A. , Lankalapalli Ravi S. , Anto Ruby J. , Bava Smitha V.
Published: April 2023

Aim: This study was designed to investigate the anticancer efficacy of the organic leaf extracts of the plant, Plectranthus vettiveroides (P. vettiveroides), and to analyze the molecular mechanism of the anticancer activity.
Methods: The leaf extracts were prepared by polarity-graded serial extraction of the dried leaf powder. The cytotoxic effect of the extracts was analyzed by the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. The most active ethyl acetate extract was subjected to bioactivity-guided fractionation by column chromatography, which yielded a cytotoxic fraction designated as the P. vettiveroides fraction (PVF). The anticancer property of PVF was confirmed further by clonogenic assay. The mechanism of PVF-induced cell death was analyzed by flow cytometry and fluorescence microscopy. Additionally, the effects of PVF on apoptotic and cell survival pathways were analyzed using western immunoblot analysis.
Results: A bioactive fraction PVF, was isolated from the ethyl acetate leaf extract. PVF showed significant anticancer activity against colon cancer cells, whilst normal cells were comparatively less affected. PVF induced strong apoptotic stimuli in colorectal carcinoma cell line HCT116, involving both extrinsic and intrinsic pathways. Investigation into the molecular mechanism of anticancer activity of PVF in HCT116 cells revealed that the fraction activates the pro-apoptotic pathway via tumor suppressor protein 53 (p53) and inhibits the anti-apoptotic pathway by regulating phosphatidylinositol 3-kinase (PI3K) signaling.
Conclusions: The findings of this study demonstrate, with mechanism-based evidence, the chemotherapeutic potential of a bioactive fraction PVF, derived from the leaves of the medicinal plant P. vettiveroides against colon cancer.
A Case Study about Innovative Electromagnetic Engineering Education based on Capacitor Charging and Discharging
Authors: Fan Hua
Published: April 2023

Capacitor charging and discharging is basic knowledge in electromagnetic education. This work proposes an innovative course teaching method of “self-learning as the mainstay, supplemented by circuit examples”, which can improve the student’s knowledge absorption and enthusiasm in the class. The simulation tool Multisim is used as an auxiliary software to strengthen the connection between theory and practice, which reviews the knowledge they have learned and helps students to develop the habit of using simulation software to assist their learning. This innovative course teaching method improves the role of students in the classroom and cultivates the ability of students to learn independently and practice automatically, lays a foundation for the design of electromagnetic theories in the future.
Numerical Study on Wind Pressures Caused by the Variation of the Rounding Radii of the Industrial Shed Eaves
Authors: Teixeira Guilherme S. , De Campos Marco D.
Published: April 2023

This work approached a typical industrial shed with varied rounded eaves, which is pointed out, in the few papers on it, as favorable to structural safety against the action of the winds. Since the literature has neglected this building configuration, the external pressure coefficients were obtained by CFD with the aid of the Ansys Workbench software, applying tetrahedral meshes in the domain discretization. Furthermore, the boundary layer around the building was modeled for greater accuracy in data capture. Using the RNG K-Epsilon model, were determined the turbulent flow effects. The results indicated a reduction in the pressure coefficients in the most sensitive regions and prone to accidents caused by wind on the roof. Finally, the flow pattern can be measured using the presented velocity fields.
Numerical Simulation in the Wind Action Analyses in Logistic Sheds with a Bridge Vent
Authors: Mendes Luan A. , De Campos Marco D.
Published: April 2023

Using Ansys Fluid Flow software, a numerical investigation was to study the wind distribution around logistic sheds with a bridge vent. Then, were considered several wind directions - direct approaching, oblique, oblique opposing, lateral, and opposing - and neighborhood conditions. The Shear Stress Transport turbulence model and rectangular mesh were employed. The application validation of the CFD technique occurred in the logistic shed without a bridge vent, and the results showed good concordance with the literature. Results analyzed areas characterized by suction and overpressure, as well as the attachment points and the recirculation zones in the flow visualization.
TECHNOLOGY FOR THE PRODUCTION OF BLANKS AND FINISHED PRODUCTS FROM PUFF AND SHAPED ROLLS
Authors:   Lecturer, Department Of Mechanical Engineering Technology And Automation, Fergana Polytechnic Institute, Fergana, Uzbekistan, Makhamadovich Tadjikuziyev Rakhmatjan , Rakhmatovna Mamatkulova Saida ,   Assistant, Department Of Light Industrial Technologies, Fergana Polytechnic Institute, Fergana, Uzbekistan
Published: April 2023

In this article, the importance of the production of semi-finished products made of metal coils and sheet metal sheets, which is developing year by year in the country, in the machine building and automobile industry, and extensive work has been carried out on new examples and styles of technological processes. The article talks about different methods in this field.
FEATURES OF THE PSYCHO-EMOTIONAL SPHERE IN PATIENTS WITH HEMISPHERIC ISCHEMIC STROKE DEPENDING ON THE PRESENCE OF COVID-19 IN HISTORY
Authors:   Tashkent Pediatric Medical Institute, Uzbekistan, Yuldasheva M. M. , Majidova E.N. ,   Tashkent Pediatric Medical Institute, Uzbekistan, Nazarova J.A. ,   Center For The Development Of Professional Qualifications Of Medical Workers Ministry Of Health Of The Republic Of Uzbekistan
Published: April 2023

This article discusses the features of the psycho-emotional sphere in patients with hemispheric ischemic stroke depending on the presence of COVID-19 in history. The hemodynamic subtype was excluded from the study due to the small number of patients, IS of unspecified etiology - due to the possibly heterogeneous structure of the pathogenesis of IS.
THE SECOND WORLD WAR IN THE UZBEKISTAN SSR CHANGES IN TAX OVER THE YEARS
Authors:   Student Faculty Of History, Department Of Archival Studies National University Of Uzbekistan, Asadova O.H.
Published: April 2023

The article analyzes the use of archival sources and various other scientific literature on the example of the Uzbek SSR, the financial authorities misorganized the work of accounting for taxpayers and their income, incomplete information on the size of farms, collective farms
Revisión del concepto de empresario: una exploración de las aportaciones de Keynes y Schumpeter
Authors: Amor Bravo Elias M.
Published: April 2023

Revisión del concepto de empresario: una exploración de las aportaciones de Keynes y Schumpeter
Un modelo contractual para la retribución de los altos directivos
Authors: Pérez Santana María Pilar , De la Fuente Sábate Juan Manuel , Hernangómez Barahona Juan
Published: April 2023

La retribución directiva ha sido ampliamente tratada desde diversos ámbitos, sin embargo, son todavía muchos los interrogantes sobre este fenómeno retributivo no han obtenido respuesta. Bajo el enfoque de la agencia, el objeto de este artículo es proponer un modelo de retribución directiva para analizar, por un lado, los diversos factores determinantes que podrían condicionar la retribución que preside los contratos —nivel o mix retributivo— y, por otro, estudiar los efectos que produce esa retribución en el comportamiento de los altos directivos y, con ello, en los resultados que obtienen para los propietarios que les contrataron. Entender este fenómeno será una buena forma de acercarse al complejo entramado humano de las organizaciones, lo que invita a tratar de validar con la realidad empresarial las hipótesis que emanan de nuestro modelo.
Calidad total en la enseñanza universitaria
Authors: Panera Mendieta Francisco
Published: April 2023

La Universidad es una empresa de servicios que sugiere no solo la intangibilidad del resultado sino la complejidad de su proceso de elaboración. La calidad precisa de una especificación clara del producto deseado establecida en función de la percepción del resultado por parte del demandante., Si perseguimos la Calidad Total, hemos de estructurar un sistema de gestión de la calidad que asegure la satisfacción global sistematizando un proceso de mejora continua basada en la mentalización y participación generalizadas de hacer las cosas cada vez mejor, interiorizando esta actitud hasta convertirla en una cultura propia de nuestra Universidad.
Factores de competitividad en el sector de las artes gráficas en España
Authors: Redondo Cano Ana
Published: April 2023

El sector de artes gráficas, como tantos otros, ha sufrido los efectos de las nuevas tecnologías de una manera muy directa, debiendo las empresas que en él operan hacer frente a los nuevos retos planteados por la introducción de dichas innovaciones. Así pues, en el presente artículo se pretende ahondar en el estudio de este sector, al que en ocasiones no se le ha prestado demasiada atención, identificando por una parte, cuáles son los principales factores o pilares donde las empresas gráficas deben sustentar sus ventajas competitivas; y por otra parte, proponer algunas de las posibles opciones estratégicas que pueden ser consideradas por estas empresas al ánimo de asegurar su continuidad en el mercado.
Las estrategias de desarrollo local: aproximación metodológica desde una perspectiva socio-económica e integral
Authors: Sanchís Palacio Joan Ramón
Published: April 2023

El desarrollo local se está convirtiendo en la actualidad en una de las estrategias de crecimiento endógeno más importantes, especialmente en el marco de la inserción socio-laboral. Su importancia obliga a dedicar un estudio sobre dicho concepto bajo un planteamiento «desde abajo», esto es, destacando y analizando el papel que desempeñan el conjunto de agentes de una determinada localidad en su desarrollo y crecimiento económico y social, aprovechando de la forma más eficiente posible los recursos disponibles. En el presente trabajo queremos sistematizar el conjunto de enfoques existentes sobre el desarrollo local así como las aproximaciones metodológicas más destacadas relacionadas con el mismo. Igualmente, se plantea la necesidad de aplicar el proceso de la Dirección Estratégica al ámbito del desarrollo local, insistiendo en el diseño de sus objetivos, la auditoría del entorno, los planes de acción a llevar a cabo y los sistemas de evaluación y control. Finalmente, se destaca el importante papel movilizador realizado por la Economía Social en el proceso de desarrollo local.
El éxito empresarial. Sus niveles de análisis y formas alternativas para su evaluación
Authors: García-Tenorio Ronda Jesús , Pérez Rodríguez María José
Published: April 2023

El éxito empresarial. Sus niveles de análisis y formas alternativas para su evaluación
Supply chain resilience: a conceptual evolution analysis
Authors: Zavala-Alcívar Antonio , Verdecho María-José , Alfaro-Saiz Juan-José
Published: April 2023

Research related to resilience in the supply chain has taken great interest in recent years, especially due to major disruptions such as COVID-19. Generating actions to minimize the impacts caused by these disruptive events has become a paramount in operations management and has become a strategic capability of the supply chain. Therefore, it is essential to know how the concept of resilience has evolved by identifying their capabilities. For this purpose, a systematic literature review was carried out, focused on gathering the concepts of resilience in supply chain management present in the literature, generating a keyword correlation analysis to establish their action approaches, and jointly analyzing the conceptual evolution. From this literature, a new definition is proposed integrating the different aspects found. Finally, conclusions are exposed.
Productividad en la Industria 4.0. Evidencias empíricas en el sector de embotellado
Authors: Casablanca Gutiérrez Pedro Manuel , Arroyo-Barrigüete José Luis
Published: April 2023

La Industria 4.0 (I4.0) ha dado lugar a un nuevo paradigma tecnológico, organizacional y económico, con un efecto importante en la competitividad de las empresas. El objetivo de este trabajo es analizar el impacto de la I4.0 en la productividad, para lo que se han empleado datos de cuatro líneas de embotellado de una empresa de bebidas espirituosas a lo largo de un periodo de seis años (2015-2020). En un sector tradicional que aborda su proceso de transformación del modelo productivo, el análisis desarrollado apunta a la importancia de considerar específicamente factores humanos y de composición de equipos de trabajo.
Access to cyclopropanes with geminal trifluoromethyl and difluoromethylphosphonate groups
Authors: Hajdin Ita , Pajkert Romana , Keßler Mira , Han Jianlin , Mei Haibo , Röschenthaler Gerd-Volker
Published: April 2023

A synthetic route to the bench-stable fluorinated masked carbene reagent diethyl 2-diazo-1,1,3,3,3-pentafluoropropylphosphonate, bearing a trifluoromethyl and a difluoromethyl group is reported for the first time. Its application in CuI-catalyzed cyclopropanation reactions with aromatic and aliphatic terminal alkenes under mild reaction conditions is demonstrated. In total, sixteen new cyclopropanes were synthesized in good to very good yields.
Algebraic Properties of 𝑷𝑮𝑳𝟐 (ℂ) for Long Exact Fibration Sequence with Sporadic Extensions
Authors: Bhattacharjee Deep
Published: April 2023

A concise formulation is given regarding the constructions of the group 𝑃𝐺𝐿2 (ℂ) with its related algebraic properties with intertwined topological aspects in the long exact fibration sequences as considered over homotopy and higher order homotopy groups with further extension to sporadic groups including the monster group formulations.
Areal velocity based DTW for abnormal trajectory detection
Authors:   The Korean Data Analysis Society, Park Ji Hun , Mun Seong Il , Ko Young Ho , Park Heon Jin
Published: April 2023

In the field of aviation safety, data analysis research is being conducted to detect the precursors of aviation accidents. A deviation trajectory, which means the trajectory of an aircraft deviating from its normal trajectory, is one of the precursor signs of an aviation accident that occurs in an en-route section. The en-route section means segment of flight from the termination point of a departure procedure to the origination point of an arrival procedure. trajectory data is track data meaning positional information according to time. A general method for calculating the dissimilarity of trajectory data having different numbers of sample points constituting the trajectory is dynamic time wrapping (DTW). However, area-based dissimilarity from normal tracks is more useful than distance-based dissimilarity for deviation trajectory detection. Therefore, in this study, ‘area velocity-based DTW (hereafter referred to as ADTW)' was developed to calculate the value corresponding to the area. Dissimilarity was calculated by DTW and ADTW methods using ADS-B (automatic dependent surveillance-broadcast) trajectory data, and then deviation tracks were determined using clustering-based outlier detection technology. For clustering, the k-medoids method, PAM (partitioning around medoids), was used. As a result of calculating the average silhouette, it was classified into two clusters, and the deviation track was detected using the dissimilarity from the representative track of each cluster. Detection criteria were constructed using quantiles. When evaluated using the average silhouette width of clusters, ADTW performed better than DTW.
On adaptive learning paths using hidden Markov models
Authors:   The Korean Data Analysis Society, Choi Hyunhee , Lee Yunji , Lee Hayun
Published: April 2023

Due to the global impact of COVID-19, the use of non-face-to-face learning is increasing. For non-face-to-face learning, it is important to create a learning path based on efficiency. This study introduces the hidden Markov model (HMM) as a method of creating a learning path known as a network in which knowledge concepts are arranged in order, that is, the path of experience that students may encounter in class. and it aims to improve the accuracy of path prediction by using a variable selection technique that includes least absolute shrinkage and selection operator (LASSO), and random forest (RF) before performing HMM. In addition, this study aims to show that the learning path based on higher-order concepts made of precedence relationships from HMM is more accurate than other candidate paths. As a result of using data shared by AI-hub (https://aihub.or.kr/), the performance of HMM when selecting relational pairs using LASSO, and RF was improved significantly, and the case of using HMM when evaluating the learning path consisting of higher concepts was excellent in terms of model goodness of fit compared to other models.
UNSTEADY FLUID FLOW IN PRESSURISED CLOSED PIPES IN EXPERIMENTAL BENCH EXAMPLES
Authors: Stosiak Michał , Urbanowicz Kamil , Towarnicki Krzysztof , Deptuła Adam , Skačkauskas Paulius , Leśniewski Tadeusz
Published: April 2023

The paper indicates the frequent occurrence of transient states in hydraulic systems. Particular attention was paid to the phenomenon of water hammer – the causes and effects of this phenomenon. A complete analytical description of this phenomenon has not yet been developed. New theoretical models are still being developed and need to be verified experimentally. The paper focuses on presenting the development of experimental stands for the study of water hammer in hydraulic pipes. Subsequent modifications of the experimental stands for the speed of the shut-off valves and their tightness, as well as for the minimisation of the occurrence of the effects of the pulsation of the performance of the pump supplying the line under investigation, are presented. The stand presented as the final one also allows the testing of transients in hydraulic lines for various types of working fluid (oil, emulsion, distilled water).
The Rapid Onset of Stellar Bars in the Baryon-dominated Centers of Disk Galaxies
Authors: Bland-Hawthorn Joss , Tepper-Garcia Thor , Agertz Oscar , Freeman Ken
Published: April 2023

Recent observations of high-redshift galactic disks (z ≈ 1–3) show a strong negative trend in the dark-matter (DM) fraction f
DM with increasing baryon surface density. For this to be true, the inner baryons must dominate over DM in early massive galaxies, as observed in the Milky Way today. If disks are dominant at early times, we show that stellar bars form promptly within these disks, leading to a high bar fraction. New James Webb Space Telescope observations provide the best evidence for mature stellar bars in this redshift range. The disk mass fraction f
disk within R

s
= 2.2 R
disk is the dominant factor determining how rapidly a bar forms. Using 3D hydro simulations of halo-bulge-disk galaxies, we confirm the “Fujii relation” for the exponential dependence of the bar formation time τ
bar as a function of f
disk. For f
disk > 0.3, the bar formation time declines exponentially fast with increasing f
disk. Instead of Fujii's arbitrary threshold for when a bar appears, for the first time, we exploit the exponential growth timescale associated with the positive feedback cycle as the bar emerges from the underlying disk. A modified, mass-dependent trend is observed for halos relevant to systems at cosmic noon (

10.5
<
log

M

halo

<
12

), where the bar onset is slower for higher-mass halos at a fixed f
disk. If baryons dominate over DM within R ≈ R

s
, we predict that a high fraction of bars will be found in high-redshift disks long before z = 1.
Back to the Starting Point: On the Simulation of the Initial Magnetic Fields and Spin Periods of Nonaccreting Pulsars
Authors: Xu Kun , Yang Hao-Ran , Mao Ying-Han , Xu Xiao-Tian , Li Xiang-Dong , Liu Jifeng
Published: April 2023

Neutron stars (NSs) play essential roles in modern astrophysics. The magnetic fields and spin periods of newborn (zero-age) NSs have a large impact on the further evolution of NSs, which are, however, poorly explored in observations due to the difficulty of finding newborn NSs. In this work, we aim to infer the magnetic fields and spin periods (B
i and P
i) of zero-age NSs from the observed properties of the NS population. We select nonaccreting NSs whose evolution is solely determined by magnetic dipole radiation. We find that both B
i and P
i can be described by lognormal distribution, and the fitting sensitively depends on our parameters.
Insights on the Sun Birth Environment in the Context of Star Cluster Formation in Hub–Filament Systems
Authors: Arzoumanian Doris , Arakawa Sota , Kobayashi Masato I. N. , Iwasaki Kazunari , Fukuda Kohei , Mori Shoji , Hirai Yutaka , Kunitomo Masanobu , Kumar M. S. Nanda , Kokubo Eiichiro
Published: April 2023

Cylindrical molecular filaments are observed to be the main sites of Sunlike star formation, while massive stars form in dense hubs at the junction of multiple filaments. The role of hub–filament configurations has not been discussed yet in relation to the birth environment of the solar system and to infer the origin of isotopic ratios of short-lived radionuclides (SLR, such as 26Al) of calcium–aluminum-rich inclusions (CAIs) observed in meteorites. In this work, we present simple analytical estimates of the impact of stellar feedback on the young solar system forming along a filament of a hub–filament system. We find that the host filament can shield the young solar system from stellar feedback, both during the formation and evolution of stars (stellar outflow, wind, and radiation) and at the end of their lives (supernovae). We show that a young solar system formed along a dense filament can be enriched with supernova ejecta (e.g., 26Al) during the formation timescale of CAIs. We also propose that the streamers recently observed around protostars may be channeling the SLR-rich material onto the young solar system. We conclude that considering hub–filament configurations as the birth environment of the Sun is important when deriving theoretical models explaining the observed properties of the solar system.
JWST/NIRCam Discovery of the First Y+Y Brown Dwarf Binary: WISE J033605.05–014350.4
Authors: Calissendorff Per , De Furio Matthew , Meyer Michael , Albert Loïc , Aganze Christian , Ali-Dib Mohamad , Bardalez Gagliuffi Daniella C. , Baron Frederique , Beichman Charles A. , Burgasser Adam J. , Cushing Michael C. , Faherty Jacqueline Kelly , Fontanive Clémence , Gelino Christopher R. , Gizis John E. , Greenbaum Alexandra Z. , Kirkpatrick J. Davy , Leggett Sandy K. , Martinache Frantz , Mary David , N’Diaye Mamadou , Pope Benjamin J. S. , Roellig Thomas , Sahlmann Johannes , Sivaramakrishnan Anand , Thorngren Daniel Peter , Ygouf Marie , Vandal Thomas
Published: April 2023

We report the discovery of the first brown dwarf binary system with a Y dwarf primary, WISE J033605.05−014350.4, observed with NIRCam on JWST with the F150W and F480M filters. We employed an empirical point-spread function binary model to identify the companion, located at a projected separation of 0.″084, position angle of 295°, and with contrasts of 2.8 and 1.8 mag in F150W and F480M, respectively. At a distance of 10 pc based on its Spitzer parallax, and assuming a random inclination distribution, the physical separation is approximately 1 au. Evolutionary models predict for that an age of 1–5 Gyr, the companion mass is about 4–12.5 Jupiter masses around the 7.5–20 Jupiter mass primary, corresponding to a companion-to-host mass fraction of q = 0.61 ± 0.05. Under the assumption of a Keplerian orbit the period for this extreme binary is in the range of 5–9 yr. The system joins a small but growing sample of ultracool dwarf binaries with effective temperatures of a few hundreds of Kelvin. Brown dwarf binaries lie at the nexus of importance for understanding the formation mechanisms of these elusive objects, as they allow us to investigate whether the companions formed as stars or as planets in a disk around the primary.
Three-dimensional Dynamics of Strongly Twisted Magnetar Magnetospheres: Kinking Flux Tubes and Global Eruptions
Authors: Mahlmann J. F. , Philippov A. A. , Mewes V. , Ripperda B. , Most E. R. , Sironi L.
Published: April 2023

The origins of the various outbursts of hard X-rays from magnetars (highly magnetized neutron stars) are still unknown. We identify instabilities in relativistic magnetospheres that can explain a range of X-ray flare luminosities. Crustal surface motions can twist the magnetar magnetosphere by shifting the frozen-in footpoints of magnetic field lines in current-carrying flux bundles. Axisymmetric (2D) magnetospheres exhibit strong eruptive dynamics, i.e., catastrophic lateral instabilities triggered by a critical footpoint displacement of ψ
crit ≳ π. In contrast, our new three-dimensional (3D) twist models with finite surface extension capture important non-axisymmetric dynamics of twisted force-free flux bundles in dipolar magnetospheres. Besides the well-established global eruption resulting (as in 2D) from lateral instabilities, such 3D structures can develop helical, kink-like dynamics, and dissipate energy locally (confined eruptions). Up to 25% of the induced twist energy is dissipated and available to power X-ray flares in powerful global eruptions, with most of our models showing an energy release in the range of the most common X-ray outbursts, ≲1043 erg. Such events occur when significant energy builds up while deeply buried in the dipole magnetosphere. Less energetic outbursts likely precede powerful flares, due to intermittent instabilities and confined eruptions of a continuously twisting flux tube. Upon reaching a critical state, global eruptions produce the necessary Poynting-flux-dominated outflows required by models prescribing the fast radio burst production in the magnetar wind—for example, via relativistic magnetic reconnection or shocks.
Barycentric rational interpolation method for solving fractional cable equation
Authors: Li Jin , Cheng Yongling
Published: April 2023

A fractional cable (FC) equation is solved by the barycentric rational interpolation method (BRIM). As the fractional derivative is a nonlocal operator, we develop a spectral method to solve the FC equation to get the coefficient matrix as the full matrix. First, the fractional derivative of the FC equation is changed to a nonsingular integral from the singular kernel to the density function. Second, an efficient quadrature of a new Gauss formula is constructed to compute it simply. Third, a matrix equation of the discrete FC equation is obtained by the unknown function replaced by a barycentric rational interpolation basis function. Then, convergence rate for FC equation of the BRIM is derived. At last, a numerical example is given to illustrate our results.
Robust portfolio choice with limited attention
Authors: Ma Yue , Li Zhongfei
Published: April 2023

This paper investigates a robust portfolio selection problem with the agent's limited attention. The agent has access to a risk-free asset and a stock in a financial market. But she does not observe perfectly the expected return rate of the stock so she has to estimate this key parameter before making decisions. Besides the general observable financial information, the agent can also acquire a news signal process whose accuracy depends on the agent's attention. We assume that the agent pays limited attention on the signal and she does not trust her estimation model. So it is necessary to consider model ambiguity in this paper as well. The agent maximizes the expected utility of her terminal wealth under the worst-case scenario. Under this setting, we derive the robust optimal strategy explicitly. In the presence of the attention and ambiguity aversion, the myopic term of the strategy, the hedging term of the strategy and the worst-case scenario are all changed. We find that more attention makes the variance of the estimated return smaller. The numerical examples also show that a more attentive agent has a better estimation of the unobservable parameter and is more confident on her estimation. Consequently, the worst-case scenario deviates less from the reference model, which implies a higher expected return rate under the worst-case scenario, thus invests more in the stock.
Qualitative results for a relativistic wave equation with multiplicative noise and damping terms
Authors: Taskesen Hatice
Published: April 2023

Wave equations describing a wide variety of wave phenomena are commonly seen in mathematical physics. The inclusion of a noise term in a deterministic wave equation allows neglected degrees of freedom or fluctuations of external fields describing the environment to be considered in the equation. Moreover, adding a noise term to the deterministic equation reveals remarkable new features in the qualitative behavior of the solution. For example, noise can lead to singularities in some equations and prevent singularities in others. Taking into account the effects of the fluctuations along with a space-time white noise, we consider a relativistic wave equation with weak and strong damping terms and investigate the effect of multiplicative noise on the behavior of solutions. The existence of local and global solutions is provided, and some qualitative properties of solutions, such as continuous dependence of solutions on initial data, and blow up of solutions, are given. Moreover, an upper bound is provided for the blow up time.
The Effect of Virtual Reality Game Teaching Technology on Students’ Immersion
Authors: Jing Zhongyong , Wang Daoxin , Zhang Yu
Published: April 2023

VR (Virtual Reality) technology as the current cutting-edge technology, is widely used in the field of education, and plays a huge advantage. VR game teaching creates an immersive learning environment so that learners can have a clearer and more intuitive understanding of professional knowledge of various disciplines, enhance their learning enthusiasm and interest in learning, and give full play to subjective initiative of learners. VR technology gradually blurs the boundary between realities and virtual, and experiential have a certain emotional investment in excessively real virtual space, to create a sense of immersion and to effectively cultivate students’ spatial thinking and higher-order thinking ability. A questionnaire on the effect of VR game teaching technology on college students’ immersion was designed, and the effects of four aspects of VR game teaching technology, namely publication rules, role description, game control, and game review on learners’ immersion were explored. Results show that publication rules, role descriptions, and game control in VR game teaching have significant positive effects on college students’ immersion. All samples of different game platforms show a significant degree of immersion (P<0.05), and two VR game platforms, namely wearable VR interaction and VR all-in-one, improve learners’ immersion more significantly. Results of this study have important reference value for integrating VR technology into three-dimensional composition teaching, stimulating students’ sense of participation in game learning, improving VR game teaching effect and improving learning efficiency.
Absence de reconnaissance d’un « sexe neutre » : la Cour européenne des droits l’Homme joue la carte de la prudence
Authors: Boisgontier Audrey
Published: April 2023

Le 31 janvier 2023, la Cour européenne des droits de l’Homme s’est prononcée sur la possibilité pour une personne intersexuée et non-binaire de demander à l’État français l’inscription de la mention « sexe neutre » sur son acte de naissance. S’appuyant sur des mécanismes classiques tels que l’existence ou non d’un consensus européen, le juge n’a pas constaté de violation de l’article 8 de la Convention, laissant ainsi le choix aux États parties de reconnaître ou non une alternative à la binarité des sexes dans leur manière d’identifier les individus. Cette solution s’inscrit dans la lignée habituelle de la jurisprudence de la Cour, où une marge d’appréciation élargie est accordée aux États lorsqu’il est question de « sujets de société » comme en l’espèce.
Catch-Up Plans “Extra Time and a Ladder to Climb”
Authors: Brevard Lisa Pertillar , McCormick Laura J.
Published: April 2023

In higher education, the responsibility for submitting course assignments falls on the student. However, it can be difficult for adult learners—particularly students facing structural inequalities and disparities—to meet assignment deadlines. The conventional approach of removing points or not accepting late assignments assumes that students are disrespectful, irresponsible, or lazy rather than overwhelmed or struggling. From a Black collectivist viewpoint, such an approach may be considered a dismissive, socially isolating, stigmatizing injustice. The missed assignment becomes a “debt with interest” that the student cannot repay. Black college students, whose worldview emphasizes community and collective responsibility, witness the disjuncture between their treatment in the academy versus personal finance options that allow them to restore, for example, a delinquent credit account. The purpose of this chapter is to provide higher education instructors with philosophical and practical guidance, within a restorative justice framework, to co-create structured catch-up plans with students.
Web Search Privacy Evaluation Metrics
Authors: Khan Rafi Ullah , Ullah Mohib , Shafi Bushra
Published: April 2023

Privacy quantification methods are used to quantify the knowledge the adverse search engine has obtained with and without privacy protection mechanisms. Thus, these methods calculate privacy exposure. Private web search techniques are based on many methods (e.g., proxy service, query modification, query exchange, and others). This variety of techniques prompted the researchers to evaluate their work differently. This section introduces the metrics used to evaluate user privacy (protection). Moreover, this section also introduces the metrics used to evaluate the performance of privacy attacks and theoretical evaluation approaches.
Data Leakage and Privacy Concerns in Public Bug Bounty Platforms
Authors: Hamad Muhammad , Hussain Altaf , Tareen Majida Khan
Published: April 2023

For long-term relationships, the websites of various businesses store the PII and PHI of customers, which are mainly targeted by hackers. Cyber breaches mainly result in lack of customer trust and downfall of the business reputation. As a result, the customers become reluctant to share PII and PHI with online businesses until provided with the protection of sensitive data. The online resources of a business need to be in compliance with GDPR and PCI DSS. Companies undergo penetration testing of the infrastructure; for this, paid white hat hackers are hired under a legal contract. The companies also adopt RVDP program, where the Bug Bounty Platforms is one of the variants of RVDP. Security researchers are rewarded with an amount of bounty in the form of money or name in the hall of fame at official website for bugs' identification. Ideally, the security researcher would perform cyber security assessment. The vulnerabilities would be reported to intended stakeholders and the remediation measures with great deal of care so that PII and PHI won't be exploited by anyone.
Security in Internet of Things
Authors: Abrar Said Ul , Ullah Kamran , Zahid Saleem , Ullah Mohib , Khan Irfan Ullah , Haq Muhammad Inam Ul
Published: April 2023

Recently, electronics devices, cognitive computing, and sensing enable the deployment of internet-of-things (IoTs) with a huge application domain. However, resource constraints such as low computing powers or limited storage leave IoTs infrastructures vulnerable to a variety of cyber-attacks. In dark-net the address space developed as designated unrestricted internet address space anticipated to be used by trustworthy hosts anywhere in the world, therefore, any communication activity is presumed to be unwanted and particularly treated as a probe, backscatter, or miss-configuration. This chapter investigates and evaluates the operation of dark-net traffic detection systems in IoTs networks. Moreover, the most recent work done to ensure security in the IoTs network has been discussed. In particular, the areas of privacy provisioning, lightweight cryptographic framework, secure routing, robustness, and DoS attacks have been addressed. Moreover, based on the analysis of existing state-of-the-art protocols, the security requirements and challenges are highlighted along with identified open issues.
Checking Students' ORAs
Authors: Macomber Matthew S. , Chandler Whitney N.
Published: April 2023

Online technology tools eliminate the need for teachers to bend to the strictures of traditional essays during assessments. Inspired by a shift in teaching and assessment needs during the pandemic, the authors experimented with requiring students to submit oral responses to novel studies in their high school English classrooms. The benefits of the digital oral reading assessment persist even as pandemic learning restrictions loosen, and the authors have since incorporated oral reading assessments into their classrooms as a matter of routine. Recommendations are provided in structuring prompts, creating rubrics, and collecting filmed responses, and solutions are offered to the problems of teacher time constraints, student testing anxiety, and the relative ease of student plagiarism. The authors provide the reader with three oral reading assessment prompts for texts of literary merit, including Octavia Butler's Kindred, Ken Kesey's One Flew Over the Cuckoo's Nest, and James McBride's The Color of Water, along with rubrics that can be adapted for use with any novel.
Empathy Through Textual and Dialogic Engagements
Authors: DeHart Jason D. , Cimo Kate
Published: April 2023

In this chapter, the co-authors explore the power of children's and youth literature as high-quality materials for building connections online during the pandemic. Both authors note their experiences, as well as texts that provided a range of connections. The chapter is a narrative case study of the first author's experiences, while the researcher/co-author includes experiences that line up both practically and theoretically. The difficulty of pandemic teaching, as mitigated by some steps in instruction, is a theme of the chapter.
Integrating Collaborative ICT Tools in Higher Education for Teaching and Learning
Authors: Dahal Niroj
Published: April 2023

In this chapter, the author will discuss his experiences working collaboratively to teach and learn in order to create an engaged pedagogy by subscribing action research methodologies in various semesters that involves his (PGD, Master, and MPhil) students of 2019-2021 batches in techno-pedagogy and its trend in learning. This chapter presents the ongoing learning of research conducted within the context of the researcher's teaching practice. The author will provide examples of some of his PGD, Master, and MPhil students' technological learning collaborative activities (i.e., LMS, Google Apps, and other open sources), including forum discussions, choices, managing quizzes, lesson study, workshops, and Google Docs activities (Doc, PowerPoints, and Jamboard), which are created for on-campus, online, and distance teaching and learning in Nepali universities (namely, Kathmandu University and Nepal Open University).
The Struggle Is Real
Authors: Hosek Vicki A. , Handsfield Lara J.
Published: April 2023

Digital environments offer opportunities and spaces for students to engage in critical literacy practices. This necessitates a teacher's critical understanding of the social structures at work in online environments while instructing students. In this chapter, findings are presented from a mixed-methods study of four practicing teachers who characterized themselves as having strong personal and pedagogical knowledge of critical digital literacies (CDL) and claimed to recruit that knowledge to their classroom practices. Data analysis of teacher surveys, lesson plans, classroom observations and interviews pointed to several obstacles the teachers faced with incorporating critical dimensions into their students' technology use. The obstacles include: school/district technology restrictions; a lack of in depth understanding of CDL, and limited modeling and opportunities during teacher education and teacher development programs to build and recruit CDL to their practices. Implications for teacher education and development and suggestions for future research are presented.
Higher Education in the Post-Pandemic Era
Authors: Al Husseiny Fatima A. , Abdallah Maya H.
Published: April 2023

This chapter explores the educational changes and new trends that emerged after the COVID-19 pandemic with a brief review of how education looked like before it. The pandemic forced schools and educational institutions to adapt to new modes of teaching and learning, including online and remote learning. This chapter examines how these changes affected education, including curriculum, assessment, and pedagogy. It also explores the role of technology in education and the importance of digital literacy skills. Finally, it highlights the future trends that we need to watch for.
Family Carers During the COVID-19 Pandemic
Authors: Balachandran Krishna Priya , Mohanraj Bhuvaneswari
Published: April 2023

Ultimately, every individual will find themselves in a caregiving or care-receiving situation at some point in life. As a family caregiver, an individual's effort to support their loved one during difficult times leaves them in a laborious situation. A remarkable number of caregivers caring for a loved one suffering from an acute illness experience a sense of meaning, fulfillment, and profound emotional and psychological rewards. However, lifelong caregiving for a significant one diagnosed with a chronic illness or disability could be onerous. The current book chapter elucidates to the readers the lived experiences of family caregivers of children with neurodevelopmental disorders. The caregivers of children with neurodevelopmental disorders go through a life-long caregiving process. Thus, this book chapter will attempt to illustrate narratives of primary caregivers of children with neurodevelopmental disorders and the paradigm shift they experienced during COVID-19. This research is a determined effort to ensure that the stories of these unsung heroes reach a wider audience.
Managing Organizational Change During Turbulent Times
Authors: Ferrari Filippo
Published: April 2023

During an organizational change, the main objective of change management actions is to generate and sustain a change commitment among the change recipients in order to increase the probability of success. This chapter therefore aims to present the antecedents, dynamics, and consequences of organizational change at a psychological and relational level, in a complex, uncertain, ambiguous, and unprecedented context. It focuses in particular on the organizational, interpersonal, and individual factors that favor coping with a turbulent scenario. This chapter shows how to develop organizational reliability, foster knowledge sharing, and adopt appropriate leadership models. Finally, the purpose of the chapter is to highlight the individual factors that favor or, conversely, hinder organizational change.
Leading Change in an Unpredictable World
Authors: Bryan Jennifer , Higgins John
Published: April 2023

Both leadership and change are contested labels and there is no universal definition. What is usefully understood by leadership and change is specific to the unique nature of a particular change and the evolving context within which it is being carried out. By paying attention to what is specifically needed in the moment around leaders and leading, change leadership becomes an approach that is fit for a specific purpose and avoids becoming a generic approach which is incapable of adjusting to local realities. By noticing how the context of change is evolving and assumptions become validated and invalidated, the fitness of the chosen approach is also kept under constant review.