bluuebunny/crossref_metadata_2025_split huggingface dataset:
On the modified fractional Korteweg–de Vries and related equations
Authors: Klein Christian , Saut Jean-Claude , Wang Yuexun 
Published: January 2022

Abstract
We consider in this paper modified fractional Korteweg–de Vries and related equations (modified Burgers–Hilbert and Whitham). They have the advantage with respect to the usual fractional KdV equation to have a defocusing case with a different dynamics. We will distinguish the weakly dispersive case where the phase velocity is unbounded for low frequencies and tends to zero at infinity and the strongly dispersive case where the phase velocity vanishes at the origin and goes to infinity at infinity. In the former case, the nonlinear hyperbolic effects dominate for large data, leading to the possibility of shock formation though the dispersive effects manifest for small initial data where scattering is possible. In the latter case, finite time blow-up is possible in the focusing case but not the shock formation. In the defocusing case global existence and scattering is expected in the energy subcritical case, while finite time blow-up is expected in the energy supercritical case. We establish rigorously the existence of shocks with blow-up time and location being explicitly computed in the weakly dispersive case, while most of the results on the strongly dispersive case are derived via numerical simulations, for large solutions. Moreover, the shock formation result can be extended to the weakly dispersive equation with some generalized nonlinearity. We will also comment briefly on the BBM versions of those equations.
Embedding information onto a dynamical system
Authors: Manjunath G 
Published: January 2022

Abstract
The celebrated Takens’ embedding theorem concerns embedding an attractor of a dynamical system in a Euclidean space of appropriate dimension through a generic delay-observation map. The embedding also establishes a topological conjugacy. In this paper, we show how an arbitrary sequence can be mapped into another space as an attractive solution of a nonautonomous dynamical system. Such mapping also entails a topological conjugacy and an embedding between the sequence and the attractive solution spaces. This result is not a generalisation of Takens embedding theorem but helps us understand what exactly is required by discrete-time state space models widely used in applications to embed an external stimulus onto its solution space. Our results settle another basic problem concerning the perturbation of an autonomous dynamical system. We describe what exactly happens to the dynamics when exogenous noise perturbs continuously a local irreducible attracting set (such as a stable fixed point) of a discrete-time autonomous dynamical system.
Spectral Moran measures on

R2

*
Authors: Yan Zhi-Hui 
Published: January 2022

Abstract
In this paper, we consider the spectral properties of the Moran measure

μ

R
,
D

on

R

2

generated by the pair

(

R
,
D

)

, where

R
=

b

1

0

0

b

2

is an expanding real matrix, and

D
=

{

D

i

}

i
=
1

∞

⊆

Z

2

with

#

D

i

=
p

, where

sup

i
∈
N
,
d
∈

D

i

|
d
|
<
∞

, and p is a prime number. Let

B

(

p

)

:

≡

1

p

j

k

:
1
⩽
j
,
k
⩽
p
−
1

and

Z

(

δ

^

E

)

=

{

x
∈

R

2

:

δ

^

E

(

x

)

=
0

}

, where

δ

E

=

1

#
E

∑

e
∈
E

δ

e

, δ

e
denotes the Dirac measure at e. We show that under the conditions that

Z

(

δ

^

D

i

)

=

⋃

j
=
1

p
−
1

(

j

a

i

+

Z

2

)

for some

a

i

∈
B

(

p

)

, and

{

x
∈

0
,
1

2

:
|

δ

^

D

i

(

x

)

|
=
1

}

=

0

0

, then

μ

R
,
D

is a spectral measure if and only if

R
=

p

k

1

0

0

p

k

2

for some

k

1

,

k

2

∈
N

. A special case is the self-affine Sierpinski-type measure with

D
=

0

0

,

1

0

,

0

1

, which was considered by Dai, Fu and the author [ACHA, 2021], over which

R
=

3

k

1

0

0

3

k

2

for some

k

i

∈
N

, i = 1, 2.
Understanding Newton’s cradle. I: modelling the ideal cradle
Authors: Gauld Colin , Cross Rod 
Published: January 2022

AbstractNewton’s cradle is often discussed in science classrooms as a clear example of the laws of conservation of momentum and energy although it has been shown that this use is somewhat misleading. Approaches to understanding the behaviour of this apparatus are often over-simplified and deficient or over-complex and with little impact among teachers. In this paper, basic principles of mechanics are used to explain the behaviour of ideal cradles of various lengths and to use a simple model by which to simulate its operation. The purpose is to demonstrate that the real behaviour of Newton’s cradle provides a rich source of application of those principles in coming to terms with how the apparatus behaves and experiencing the process of modelling in physics.
Covariant effective action for generalized Proca theories
Authors: Panda Sukanta , Tinwala Abbas Altafhussain , Vidyarthi Archit 
Published: January 2022

Abstract
We investigate the quantum stability of generalised Proca theories in curved spacetime treating gravity as a dynamical field. To compute the quantum gravitational corrections, we evaluate the divergent part of the effective action at one-loop level using Vilkovisky-DeWitt formalism, which gives us a gauge invariant and gauge condition independent effective action. It is shown that the quantum corrections are suppressed by a UV cutoff parametrically higher than the Proca mass, if the coupling constants are restricted to lie in a certain range. Furthermore, it is shown that the quantum corrections remain suppressed even at scales where classical non-linearities dominate over kinetic terms, allowing Vainshtein mechanism to work.
Investigation and control of laser pointing fluctuations on stability of terahertz time domain spectrometer
Authors: Mumtaz Muhammad , D Khan Sabih , Aslam Zia M , Shahzad Arslan , Ahmad Izhar 
Published: January 2022

Abstract
Terahertz time domain spectroscopy (THz-TDS) is a well known technique for analyzing materials in terahertz regime. The stability and reproducibility of the THz signal amplitude is most crucial for reliable measurements using this technique. In this article, an extensive investigation on the origin and the impact of beam pointing fluctuations on amplitude of THz signal is performed. These fluctuations have been reduced to minimum level with control on sources of beam pointing fluctuation including air turbulences and temperature drifts. Under these controlled conditions, the standard deviation in the measurement of refractive index and absorption coefficient have been reduced up to

1.3
×

10

−
4

and 0.2 cm−1, respectively.
Summary of the 13th IAEA technical meeting on plasma control systems, data management and remote experiments in fusion research
Authors: Waterhouse John , Barbarino Matteo 
Published: January 2022

Abstract
This report summarizes the contributions presented at the IAEA technical meeting on 13th IAEA technical meeting on plasma control systems, data management and remote experiments in fusion research, hosted by UKAEA and held virtually, on 5–8 July 2021. The meeting brought together 90 experts from nuclear fusion research sites worldwide. The main topics of the meeting were plasma control; machine control, monitoring, safety and remote manipulation; data acquisition and signal processing; database techniques for information storage and retrieval; advanced computing and massive data analysis; remote participation and virtual laboratory; and fast network technology and its application.
Violent relaxation in the Hamiltonian mean field model: II. Non-equilibrium phase diagrams
Authors: Santini Alessandro , Giachetti Guido , Casetti Lapo 
Published: January 2022

Abstract
A classical long-range-interacting N-particle system relaxes to thermal equilibrium on time scales growing with N; in the limit N → ∞ such a relaxation time diverges. However, a completely non-collisional relaxation process, known as violent relaxation, takes place on a much shorter time scale independent of N and brings the system towards a non-thermal quasi-stationary state (QSS). A finite system will eventually reach thermal equilibrium, while an infinite system will remain trapped in the QSS forever. For times smaller than the relaxation time, the distribution function of the system obeys the collisionless Boltzmann equation, also known as the Vlasov equation. The Vlasov dynamics are invariant under time reversal so that they do not ‘naturally’ describe the relaxational dynamics. However, as time grows the dynamics affect smaller and smaller scales in phase space, so that observables not depending upon small-scale details appear as relaxed after a short time. Herewith we present an approximation scheme able to describe violent relaxation in a one-dimensional toy-model, the Hamiltonian mean field. The approach described here generalizes the one proposed in Giachetti and Casetti (2019 J. Stat. Mech. 043201), which was limited to ‘cold’ initial conditions, to generic initial conditions, allowing us to predict non-equilibrium phase diagrams that turn out to be in good agreement with those obtained from the numerical integration of the Vlasov equation.
Direction-sweep Markov chains
Authors: Qin Liang , Höllmer Philipp , Krauth Werner 
Published: January 2022

Abstract
We discuss a non-reversible, lifted Markov-chain Monte Carlo (MCMC) algorithm for particle systems in which the direction of proposed displacements is changed deterministically. This algorithm sweeps through directions analogously to the popular MCMC sweep methods for particle or spin indices. Direction-sweep MCMC can be applied to a wide range of reversible or non-reversible Markov chains, such as the Metropolis algorithm or the event-chain Monte Carlo algorithm. For a single two-dimensional tethered hard-disk dipole, we consider direction-sweep MCMC in the limit where restricted equilibrium is reached among the accessible configurations for a fixed direction before incrementing it. We show rigorously that direction-sweep MCMC leaves the stationary probability distribution unchanged and that it profoundly modifies the Markov-chain trajectory. Long excursions, with persistent rotation in one direction, alternate with long sequences of rapid zigzags resulting in persistent rotation in the opposite direction in the limit of small direction increments. The mapping to a Langevin equation then yields the exact scaling of excursions while the zigzags are described through a non-linear differential equation that is solved exactly. We show that the direction-sweep algorithm can have shorter mixing times than the algorithms with random updates of directions. We point out possible applications of direction-sweep MCMC in polymer physics and in molecular simulation.
Locally equivalent quasifree states and index theory
Authors: Bourne Chris 
Published: January 2022

AbstractWe consider quasifree ground states of Araki’s self-dual canonical anti-commutation relation algebra from the viewpoint of index theory and symmetry protected topological (SPT) phases. We first review how Clifford module indices characterise a topological obstruction to connect pairs of symmetric gapped ground states. This construction is then generalised to give invariants inKO*(Ar)withAaC*,r-algebra of allowed deformations. WhenA=C*(X), the Roe algebra of a coarse spaceX, and we restrict to gapped ground states that are locally equivalent with respectX, aK-homology class is also constructed. The coarse assembly map relates these two classes and clarifies the relevance ofK-homology to free-fermionic SPT phases.
Model experiments for Czochralski crystal growth processes using inductive and resistive heating
Authors: Enders-Seidlitz A , Pal J , Dadzis K 
Published: January 2022

Abstract
The Czochralski (CZ) growth technique is widely applied in crystal growth, using both induction and resistance heaters. In this work, a novel model experiment platform with comprehensive in-situ measurement capability is introduced. Growth experiments with the model material tin applying both heating concepts are performed and analyzed, e.g., in terms of the maximum achievable crystal diameter. Strong asymmetries in the magnetic field of the induction heater are measured and temperature distribution on the resistance heater is found to be non-uniform. Furthermore, significant losses are observed in the power supplies of the resistance heater. The heating efficiency of both concepts is compared considering different insulation geometries. The obtained results show the capability of model experiments for design optimization and will provide valuable input for further validation of numerical simulations.
Twenty Years’ Research on Microwave Application to Metal Production and Recycling
Authors: Yoshikawa Noboru 
Published: January 2022

Abstract
Ever since discovery of microwave heating in 1946, its application has been developed in various fields. Our research group has performed intensive studies on microwave heating application to metal production and recycling for these twenty years. In this article, it is intended to introduce our attempts having made for different projects. They are 1. Microwave processing of Ti bearing blast furnace slag, microstructural alteration and comminution. 2. Microwave carbo-thermic reduction of valuable metals from various oxides. 3. Microwave drying and dehydration of wet wastes. 4. Vapor de-phosphorization by microwave rapid heating. It is to be emphasized that we utilized a single mode microwave applicator for the purpose of clarification on the heating mechanisms of various metallurgical matters and compounds, and it was intended to discuss the reaction kinetics excited by microwave heating.
Durable, self-cleaning and anti-fouling superhydrophobic coating based on double epoxy layer
Authors: Li Xiang , Liu Hua , Zhang Yingbing , Liu Zuozhen 
Published: January 2022

Abstract
The practical application of superhydrophobic coatings has been greatly restricted due to the complicated preparation and fragile hierarchical structures on the surface. In this study, we prepared a robust superhydrophobic coating with a double-layer structure via a low-cost and facile method, adhering the non-wettability layer composed of silica nanoparticles and fluorine-modified epoxy resin to a binder resin layer on aluminum. The fluorine-modified epoxy resin with low surface energy can fix the silica nanoparticles after curing and cross-link with the adhesive layer. When the SiO2 content in the surface layer is 40%, the water contact angle (WCA) of the coating is 162°, and the sliding angle (SA) is 2°. In the mechanical performance test, the durable coating can remain superhydrophobic even after 260 cycles of friction or 160 cycles of tape peeling. In addition, the superhydrophobic coating with self-cleaning and anti-fouling properties also has the performance of acid-base solution resistance. Hence, the combination of the rough layer and the adhesive layer makes the practical application of artificial superhydrophobic coatings possible.
On Variance of the Treatment Effect in the Treated When Estimated by Inverse Probability Weighting
Authors: Reifeis Sarah A , Hudgens Michael G 
Published: January 2022

Abstract
In the analysis of observational studies, inverse probability weighting (IPW) is commonly used to consistently estimate the average treatment effect (ATE) or the average treatment effect in the treated (ATT). The variance of the IPW ATE estimator is often estimated by assuming that the weights are known and then using the so-called “robust” (Huber-White) sandwich estimator, which results in conservative standard errors (SEs). Here we show that using such an approach when estimating the variance of the IPW ATT estimator does not necessarily result in conservative SE estimates. That is, assuming the weights are known, the robust sandwich estimator may be either conservative or anticonservative. Thus, confidence intervals for the ATT using the robust SE estimate will not be valid, in general. Instead, stacked estimating equations which account for the weight estimation can be used to compute a consistent, closed-form variance estimator for the IPW ATT estimator. The 2 variance estimators are compared via simulation studies and in a data analysis of the association between smoking and gene expression.
Evaluating Confounding Control in Estimations of Influenza Antiviral Effectiveness in Electronic Health Plan Data
Authors: Htoo Phyo T , Measer Gregory , Orr Robert , Bohn Justin , Sorbello Alfred , Francis Henry , Dutcher Sarah K , Cosgrove Austin , Carruth Amanda , Toh Sengwee , Cocoros Noelle M 
Published: January 2022

Abstract
Observational studies of oseltamivir use and influenza complications could suffer from residual confounding. Using negative control risk periods and a negative control outcome, we examined confounding control in a health-insurance-claims–based study of oseltamivir and influenza complications (pneumonia, all-cause hospitalization, and dispensing of an antibiotic). Within the Food and Drug Administration’s Sentinel System, we identified individuals aged ≥18 years who initiated oseltamivir use on the influenza diagnosis date versus those who did not, during 3 influenza seasons (2014–2017). We evaluated primary outcomes within the following 1–30 days (the primary risk period) and 61–90 days (the negative control period) and nonvertebral fractures (the negative control outcome) within days 1–30. We estimated propensity-score–matched risk ratios (RRs) per season. During the 2014–2015 influenza season, oseltamivir use was associated with a reduction in the risk of pneumonia (RR = 0.72, 95% confidence interval (CI): 0.70, 0.75) and all-cause hospitalization (RR = 0.54, 95% CI: 0.53, 0.55) in days 1–30. During days 61–90, estimates were near-null for pneumonia (RR = 1.04, 95% CI: 0.95, 1.15) and hospitalization (RR = 0.94, 95% CI: 0.91, 0.98) but slightly increased for antibiotic dispensing (RR = 1.14, 95% CI: 1.08, 1.21). The RR for fractures was near-null (RR = 1.09, 95% CI: 0.99, 1.20). Estimates for the 2016–2017 influenza season were comparable, while the 2015–2016 season had conflicting results. Our study suggests minimal residual confounding for specific outcomes, but results differed by season.
Living in mixed-sex groups limits sexual selection as a driver of pelage dimorphism in bovids
Authors: D’Ammando Giacomo , Franks Daniel W , Bro-Jørgensen Jakob 
Published: January 2022

AbstractAmong mammals, bovids provide some of the most striking examples of sexual dimorphism in colouration and pelage appendages, such as beards and manes. This dimorphism is usually assumed to have evolved through sexual selection on males in the context of intra- or intersexual communication. However, the sexes coloration and pelage appendages look similar between the two sexes in several bovid species thought to be characterized by large opportunities for sexual selection, hinting at fitness costs of dimorphic traits due to other selection pressures. This study applies the comparative method with phylogenetic control to identify the factors promoting and constraining the evolution of dimorphism in coloration and pelage appendages across bovids. We found that trait dimorphism correlated positively with large breeding group size, an indicator of the intensity of sexual selection, and negatively with male territoriality, which is also likely to affect the operation of sexual selection. The relative rarity of color and pelage dimorphism in species with territorial mating systems may be explained by weaker sexual selection due to difficulty in monopolizing females and/or sexual selection targeting other traits, such as territorial quality as an extended phenotype. We also found that dimorphism in color and pelage was reduced in species spending more time in mixed-sex groups outside the breeding season, possibly due to increased predation costs from non-uniformity. This suggests that benefits from integration into mixed-sex groups select against the extravagant male morphologies otherwise promoted by sexual selection.
Evolution of European carnivorous mammal assemblages through the Palaeogene
Authors: Solé Floréal , Fischer Valentin , Le Verger Kévin , Mennecart Bastien , Speijer Robert P , Peigné Stéphane , Smith Thierry 
Published: January 2022

AbstractThe rise of Carnivora (Mammalia: Laurasiatheria) is an important evolutionary event that changed the structure of terrestrial ecosystems, starting at the dawn of the Eocene, 56 Mya. This radiation has been mainly analysed in North America, leaving the evolution of carnivoran diversity in other regions of the globe poorly known. To tackle this issue, we review the evolution of terrestrial carnivorous mammal diversity (Mesonychidae, Oxyaenidae, Hyaenodonta and Carnivoramorpha) in Europe. We reveal four episodes of intense faunal turnovers that helped establish the dominance of carnivoramorphans over their main competitors. We also identify two periods of general endemism. The remaining time intervals are characterized by dispersals of new taxa from North America, Asia and Africa. The European Palaeogene carnivorous mammal fauna appears to have been almost constantly in a transient state, strongly influenced by dispersals. Many of the bioevents we highlight for European carnivorous mammals are probably best seen as ecosystem-wide responses to environmental changes. In contrast to the North American record, European hyaenodonts remain more diverse than the carnivoramorphans for the entire Eocene. The replacement of hyaenodonts by carnivoramorphans as the most diverse and dominant predators only occurred after the ‘Grande Coupure’ at 33 Mya, about 16 Myr later than in North America.
Five questions toward mRNA degradation in oocytes and preimplantation embryos: when, who, to whom, how, and why?
Authors: Jiang Zhi-Yan , Fan Heng-Yu 
Published: January 2022

AbstractRNA—the primary product of the genome—is subject to various biological events during its lifetime. During mammalian gametogenesis and early embryogenesis, germ cells and preimplantation embryos undergo marked changes in the transcriptome, including mRNA turnover. Various factors, including specialized proteins, RNAs, and organelles, function in an intricate degradation system, and the degradation selectivity is determined by effectors and their target mRNAs. RNA homeostasis regulators and surveillance factors function in the global transcriptome of oocytes and somatic cells. Other factors, including BTG4, PABPN1L, the CCR4-NOT subunits, CNOT6L and CNOT7, and TUTs, are responsible for two maternal mRNA avalanches: M- and Z-decay. In this review, we discuss recent advances in mRNA degradation mechanisms in mammalian oocytes and preimplantation embryos. We focused on the studies in mice, as a model mammalian species, and on RNA turnover effectors and the cis-elements in targeting RNAs.