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On nonautonomous differentialdifference AKP, BKP and CKP equations Proc. Royal Soc. A: Math. Phys. Eng. Sci. (IF 2.741) Pub Date : 20210120
Wei Fu; Frank W. NijhoffBased on the direct linearization framework of the discrete Kadomtsev–Petviashvilitype equations presented in the work of Fu & Nijhoff (Fu W, Nijhoff FW. 2017 Direct linearizing transform for threedimensional discrete integrable systems: the lattice AKP, BKP and CKP equations. Proc. R. Soc. A473, 20160915 (doi:10.1098/rspa.2016.0915)), six novel nonautonomous differentialdifference equations are

Granular size segregation in silos with and without inserts Proc. Royal Soc. A: Math. Phys. Eng. Sci. (IF 2.741) Pub Date : 20210120
A. Cliff; L. A. Fullard; E. C. P. Breard; J. Dufek; C. E. DaviesThe storage of granular materials is a critical process in industry, which has driven research into flow in silos. Varying material properties, such as particle size, can cause segregation of mixtures. This work seeks to elucidate the effects of size differences and determine how using a flowcorrecting insert mitigates segregation during silo discharge. A rotating table was used to collect mustard

Elastic multiblisters induced by geometric constraints Proc. Royal Soc. A: Math. Phys. Eng. Sci. (IF 2.741) Pub Date : 20210120
D. De Tommasi; G. Devillanova; F. Maddalena; G. Napoli; G. PuglisiWe study a prototypical system describing instability effects due to geometric constraints in the framework of nonlinear elasticity. By considering the equilibrium configurations of an elastic ring constrained inside a rigid circle with smaller radius, we analytically determine different possible shapes, reproducing wellknown physical phenomena. As we show, both single (with different complexity)

Complementary roles of mechanotransduction and inflammation in vascular homeostasis Proc. Royal Soc. A: Math. Phys. Eng. Sci. (IF 2.741) Pub Date : 20210120
Marcos Latorre; Bart Spronck; Jay D. HumphreyArteries are exposed to relentless pulsatile haemodynamic loads, but via mechanical homeostasis they tend to maintain near optimal structure, properties and function over long periods in maturity in health. Numerous insults can compromise such homeostatic tendencies, however, resulting in maladaptations or disease. Chronic inflammation can be counted among the detrimental insults experienced by arteries

Breakdown of similarity solutions: a perturbation approach for front propagation during foamimproved oil recovery Proc. Royal Soc. A: Math. Phys. Eng. Sci. (IF 2.741) Pub Date : 20210120
Carlos TorresUlloa; Paul GrassiaThe pressuredriven growth model has been employed to study a propagating foam front in the foamimproved oil recovery process. A firstorder solution of the model proves the existence of a concave corner on the front, which initially migrates downwards at a well defined speed that differs from the speed of front material points. At later times, however, it remains unclear how the concave corner moves

Tunable mechanical diode of nonlinear elastic metamaterials induced by imperfect interface Proc. Royal Soc. A: Math. Phys. Eng. Sci. (IF 2.741) Pub Date : 20210120
ZhenNi Li; YiZe Wang; YueSheng WangIn this investigation, the nonreciprocal transmission in a nonlinear elastic metamaterial with imperfect interfaces is studied. Based on the Bloch theorem and stiffness matrix method, the band gaps and transmission coefficients with imperfect interfaces are obtained for the fundamental and double frequency cases. The interfacial influences on the transmission behaviour are discussed for both the nonlinear

Evolution of spray and aerosol from respiratory releases: theoretical estimates for insight on viral transmission Proc. Royal Soc. A: Math. Phys. Eng. Sci. (IF 2.741) Pub Date : 20210120
P. M. de Oliveira; L. C. C. Mesquita; S. Gkantonas; A. Giusti; E. MastorakosBy modelling the evaporation and settling of droplets emitted during respiratory releases and using previous measurements of droplet size distributions and SARSCoV2 viral load, estimates of the evolution of the liquid mass and the number of viral copies suspended were performed as a function of time from the release. The settling times of a droplet cloud and its suspended viral dose are significantly

Wireless power distributions in multicavity systems at high frequencies Proc. Royal Soc. A: Math. Phys. Eng. Sci. (IF 2.741) Pub Date : 20210120
Farasatul Adnan; Valon Blakaj; Sendy Phang; Thomas M. Antonsen; Stephen C. Creagh; Gabriele Gradoni; Gregor TannerThe next generations of wireless networks will work in frequency bands ranging from sub6 GHz up to 100 GHz. Radio signal propagation differs here in several critical aspects from the behaviour in the microwave frequencies currently used. With wavelengths in the millimetre range (mmWave), both penetration loss and freespace path loss increase, while specular reflection will dominate over diffraction

Understanding the role of urban design in disease spreading Proc. Royal Soc. A: Math. Phys. Eng. Sci. (IF 2.741) Pub Date : 20210113
Noel G. Brizuela; Nstor GarcaChan; Humberto Gutirrez Pulido; Gerardo ChowellCities are complex systems whose characteristics impact the health of people who live in them. Nonetheless, urban determinants of health often vary within spatial scales smaller than the resolution of epidemiological datasets. Thus, as cities expand and their inequalities grow, the development of theoretical frameworks that explain health at the neighbourhood level is becoming increasingly critical

Revisiting imperfect interface laws for twodimensional elastodynamics Proc. Royal Soc. A: Math. Phys. Eng. Sci. (IF 2.741) Pub Date : 20210113
Kim Pham; Agns Maurel; JeanJacques MarigoWe study the interaction of inplane elastic waves with imperfect interfaces composed of a periodic array of voids or cracks. An effective model is derived from highorder asymptotic analysis based on twoscale homogenization and matched asymptotic technique. In twodimensional elasticity, we obtain jump conditions set on the inplane displacements and normal stresses; the jumps involve in addition

Highresolution thickness maps of corrosion using SH1 guided wave tomography Proc. Royal Soc. A: Math. Phys. Eng. Sci. (IF 2.741) Pub Date : 20210113
Andreas A. E. Zimmermann; Peter Huthwaite; Brian PavlakovicQuantifying corrosion damage is vital for the petrochemical industry, and guided wave tomography can provide thickness maps of such regions by transmitting guided waves through these areas and capturing the scattering information using arrays. The dispersive nature of the guided waves enables a reconstruction of wave velocity to be converted into thickness. However, existing approaches have been shown

Numerical calculation of Nperiodic wave solutions to coupled KdVTodatype equations Proc. Royal Soc. A: Math. Phys. Eng. Sci. (IF 2.741) Pub Date : 20210113
Yingnan Zhang; Xingbiao Hu; Jianqing SunIn this paper, we study the Nperiodic wave solutions of coupled Korteweg–de Vries (KdV)–Todatype equations. We present a numerical process to calculate the Nperiodic waves based on the direct method of calculating periodic wave solutions proposed by Akira Nakamura. Particularly, in the case of N = 3, we give some detailed examples to show the Nperiodic wave solutions to the coupled Ramani equation

The mathematical foundations of anelasticity: existence of smooth global intermediate configurations Proc. Royal Soc. A: Math. Phys. Eng. Sci. (IF 2.741) Pub Date : 20210106
Christian Goodbrake; Alain Goriely; Arash YavariA central tool of nonlinear anelasticity is the multiplicative decomposition of the deformation tensor that assumes that the deformation gradient can be decomposed as a product of an elastic and an anelastic tensor. It is usually justified by the existence of an intermediate configuration. Yet, this configuration cannot exist in Euclidean space, in general, and the mathematical basis for this assumption

Topological charges and conservation laws involving an arbitrary function of time for dynamical PDEs Proc. Royal Soc. A: Math. Phys. Eng. Sci. (IF 2.741) Pub Date : 20210106
Stephen C. Anco; Elena RecioDynamical PDEs that have a spatial divergence form possess conservation laws that involve an arbitrary function of time. In one spatial dimension, such conservation laws are shown to describe the presence of an xindependent source/sink; in two and more spatial dimensions, they are shown to produce a topological charge. Two applications are demonstrated. First, a topological charge gives rise to an

Firstorder convergence of Milstein schemes for McKeanVlasov equations and interacting particle systems Proc. Royal Soc. A: Math. Phys. Eng. Sci. (IF 2.741) Pub Date : 20210106
Jianhai Bao; Christoph Reisinger; Panpan Ren; Wolfgang StockingerIn this paper, we derive fully implementable firstorder timestepping schemes for McKean–Vlasov stochastic differential equations, allowing for a drift term with superlinear growth in the state component. We propose Milstein schemes for a timediscretized interacting particle system associated with the McKean–Vlasov equation and prove strong convergence of order 1 and moment stability, taming the

A new approach to integrable evolution equations on the circle Proc. Royal Soc. A: Math. Phys. Eng. Sci. (IF 2.741) Pub Date : 20210106
A. S. Fokas; J. LenellsWe propose a new approach for the solution of initial value problems for integrable evolution equations in the periodic setting based on the unified transform. Using the nonlinear Schrödinger equation as a model example, we show that the solution of the initial value problem on the circle can be expressed in terms of the solution of a Riemann–Hilbert problem whose formulation involves quantities which

Using adjointbased optimization to enhance ignition in nonpremixed jets Proc. Royal Soc. A: Math. Phys. Eng. Sci. (IF 2.741) Pub Date : 20210106
Ubaid Ali Qadri; Luca Magri; Matthias Ihme; Peter J. SchmidGradientbased optimization is used to reliably and optimally induce ignition in three examples of laminar nonpremixed mixture configurations. Using timeintegrated heat release as a cost functional, the nonconvex optimization problem identified optimal energy source locations that coincide with the stoichiometric local mixture fraction surface for short optimization horizons, while for longer horizons

An agentbased model of the interrelation between the COVID19 outbreak and economic activities Proc. Royal Soc. A: Math. Phys. Eng. Sci. (IF 2.741) Pub Date : 20210106
Takeshi Kano; Kotaro Yasui; Taishi Mikami; Munehiro Asally; Akio IshiguroAs of July 2020, COVID19 caused by SARSCOV2 is spreading worldwide, causing severe economic damage. While minimizing human contact is effective in managing outbreaks, it causes severe economic losses. Strategies to solve this dilemma by considering the interrelation between the spread of the virus and economic activities are urgently needed to mitigate the health and economic damage. Here, we propose

Psychophysical study of the moon illusion in paintings and landscape photos Proc. Royal Soc. A: Math. Phys. Eng. Sci. (IF 2.741) Pub Date : 20210106
Zoltn Kovcs; Zoltn Udvarnoki; Eszter Papp; Gbor HorvthThe moon illusion is a visual deception when people perceive the angular diameter of the Moon/Sun near the horizon larger than that of the one higher in the sky. Some theories have been proposed to explain this illusion, but not any is generally accepted. Although several psychophysical experiments have been performed to study different aspects of the moon illusion, their results have sometimes contradicted

Mtheory, black holes and cosmology Proc. Royal Soc. A: Math. Phys. Eng. Sci. (IF 2.741) Pub Date : 20210106
Renata KalloshThis paper is dedicated to Michael J. Duff on the occasion of his 70th birthday. I discuss some issues of Mtheory/string theory/supergravity closely related to Mike’s interests. I describe a relation between STU black hole entropy, the Cayley hyperdeterminant, the Bhargava cube and a threequbit Alice–Bob–Charlie triality symmetry. I shortly describe my recent work with Gunaydin, Linde and Yamada

Analytical continuation of twodimensional wave fields Proc. Royal Soc. A: Math. Phys. Eng. Sci. (IF 2.741) Pub Date : 20210106
Raphal C. Assier; Andrey V. ShaninWave fields obeying the twodimensional Helmholtz equation on branched surfaces (Sommerfeld surfaces) are studied. Such surfaces appear naturally as a result of applying the reflection method to diffraction problems with straight scatterers bearing ideal boundary conditions. This is for example the case for the classical canonical problems of diffraction by a halfline or a segment. In the present

Heavytailed distributions, correlations, kurtosis and Taylors Law of fluctuation scaling Proc. Royal Soc. A: Math. Phys. Eng. Sci. (IF 2.741) Pub Date : 20201223
Joel E. Cohen; Richard A. Davis; Gennady SamorodnitskyPillai & Meng (Pillai & Meng 2016 Ann. Stat.44, 2089–2097; p. 2091) speculated that ‘the dependence among [random variables, rvs] can be overwhelmed by the heaviness of their marginal tails ·· ·’. We give examples of statistical models that support this speculation. While under natural conditions the sample correlation of regularly varying (RV) rvs converges to a generally random limit, this limit

A statistical theory of the strength of epidemics: an application to the Italian COVID19 case Proc. Royal Soc. A: Math. Phys. Eng. Sci. (IF 2.741) Pub Date : 20201223
Gabriele Pisano; Gianni RoyerCarfagniThe proposed theory defines a relative index of epidemic lethality that compares any two configurations in different observation periods, preferably one in the acute and the other in a mild epidemic phase. Raw mortality data represent the input, with no need to recognize the cause of death. Data are categorized according to the victims’ age, which must be renormalized because older people have a greater

Response theory and phase transitions for the thermodynamic limit of interacting identical systems Proc. Royal Soc. A: Math. Phys. Eng. Sci. (IF 2.741) Pub Date : 20201223
Valerio Lucarini; Grigorios A. Pavliotis; Niccol ZagliWe study the response to perturbations in the thermodynamic limit of a network of coupled identical agents undergoing a stochastic evolution which, in general, describes nonequilibrium conditions. All systems are nudged towards the common centre of mass. We derive Kramers–Kronig relations and sum rules for the linear susceptibilities obtained through mean field Fokker–Planck equations and then propose

Threephase flow displacement dynamics and Haines jumps in a hydrophobic porous medium Proc. Royal Soc. A: Math. Phys. Eng. Sci. (IF 2.741) Pub Date : 20201223
Abdulla Alhosani; Alessio Scanziani; Qingyang Lin; Ahmed Selem; Ziqing Pan; Martin J. Blunt; Branko BijeljicWe use synchrotron Xray microtomography to investigate the displacement dynamics during threephase—oil, water and gas—flow in a hydrophobic porous medium. We observe a distinct gas invasion pattern, where gas progresses through the pore space in the form of disconnected clusters mediated by double and multiple displacement events. Gas advances in a process we name threephase Haines jumps, during

Violations of the ClausiusDuhem inequality in Couette flows of granular media Proc. Royal Soc. A: Math. Phys. Eng. Sci. (IF 2.741) Pub Date : 20201223
Martin OstojaStarzewski; Rossella LaudaniSpontaneous violations of the Clausius–Duhem (CD) inequality in Couettetype collisional flows of model granular media are studied. Planar systems of monosized circular discs (with disc numbers from 10 to 204, and disc diameters from 0.001 m to 1 m) with frictionalHookean contacts are simulated under periodic boundary conditions by a molecular dynamics. The scaledependent homogenization of micropolar

Absence of diagonal force constants in cubic Coulomb crystals Proc. Royal Soc. A: Math. Phys. Eng. Sci. (IF 2.741) Pub Date : 20201223
Bartholomew Andrews; Gareth ConduitThe quasiharmonic model proposes that a crystal can be modelled as atoms connected by springs. We demonstrate how this viewpoint can be misleading: a simple application of Gauss’s law shows that the ion–ion potential for a cubic Coulomb system can have no diagonal harmonic contribution and so cannot necessarily be modelled by springs. We investigate the repercussions of this observation by examining

Capillary transport in paper porous materials at low saturation levels: normal, fast or superfast? Proc. Royal Soc. A: Math. Phys. Eng. Sci. (IF 2.741) Pub Date : 20201223
Alex V. Lukyanov; Vladimir V. Mitkin; Tristan Pryer; Penpark Sirimark; Theo G. TheofanousThe problem of capillary transport in fibrous porous materials at low levels of liquid saturation has been addressed. It has been demonstrated that the process of liquid spreading in this type of porous material at low saturation can be described macroscopically by a similar superfast, nonlinear diffusion model to that which had been previously identified in experiments and simulations in particulate

Diffusion in arrays of obstacles: beyond homogenization Proc. Royal Soc. A: Math. Phys. Eng. Sci. (IF 2.741) Pub Date : 20201223
Yahya Farah; Daniel Loghin; Alexandra Tzella; Jacques VannesteWe revisit the classical problem of diffusion of a scalar (or heat) released in a twodimensional medium with an embedded periodic array of impermeable obstacles such as perforations. Homogenization theory provides a coarsegrained description of the scalar at large times and predicts that it diffuses with a certain effective diffusivity, so the concentration is approximately Gaussian. We improve on

Radiofrequency chain selection for energy and spectral efficiency maximization in hybrid beamforming under hardware imperfections Proc. Royal Soc. A: Math. Phys. Eng. Sci. (IF 2.741) Pub Date : 20201223
Evangelos Vlachos; John Thompson; Aryan Kaushik; Christos MasourosThe nextgeneration wireless communications require reduced energy consumption, increased data rates and better signal coverage. The millimetrewave frequency spectrum above 30 GHz can help fulfil the performance requirements of the nextgeneration mobile broadband systems. Multipleinput multipleoutput technology can provide performance gains to help mitigate the increased path loss experienced at

Matrix models and deformations of JT gravity Proc. Royal Soc. A: Math. Phys. Eng. Sci. (IF 2.741) Pub Date : 20201223
Edward WittenRecently, it has been found that JackiwTeitelboim (JT) gravity, which is a twodimensional theory with bulk action −1/2∫d2xgϕ(R+2), is dual to a matrix model, that is, a random ensemble of quantum systems rather than a specific quantum mechanical system. In this article, we argue that a deformation of JT gravity with bulk action −1/2∫d2xg(ϕR+W(ϕ)) is likewise dual to a matrix model. With a specific

Modelling foam improved oil recovery: towards a formulation of pressuredriven growth with flow reversal Proc. Royal Soc. A: Math. Phys. Eng. Sci. (IF 2.741) Pub Date : 20201216
M. Eneotu; P. GrassiaThe pressuredriven growth model that describes the twodimensional (2D) propagation of a foam through an oil reservoir is considered as a model for surfactantalternatinggas improved oil recovery. The model assumes a region of low mobility, finely textured foam at the foam front where injected gas meets liquid. The net pressure driving the foam is assumed to reduce suddenly at a specific time. Parts

Overcoming the curse of dimensionality in the numerical approximation of semilinear parabolic partial differential equations Proc. Royal Soc. A: Math. Phys. Eng. Sci. (IF 2.741) Pub Date : 20201216
Martin Hutzenthaler; Arnulf Jentzen; Thomas Kruse; Tuan Anh Nguyen; Philippe von WurstembergerFor a long time it has been wellknown that highdimensional linear parabolic partial differential equations (PDEs) can be approximated by Monte Carlo methods with a computational effort which grows polynomially both in the dimension and in the reciprocal of the prescribed accuracy. In other words, linear PDEs do not suffer from the curse of dimensionality. For general semilinear PDEs with Lipschitz

The Born rule as a statistics of quantum microevents Proc. Royal Soc. A: Math. Phys. Eng. Sci. (IF 2.741) Pub Date : 20201216
Yurii V. BrezhnevWe deduce the Born rule from a purely statistical take on quantum theory within minimalistic mathsetup. No use is required of quantum postulates. One exploits only rudimentary quantum mathematics—a linear, not Hilbert’, vector space—and empirical notion of the Statistical Length of a state. Its statistical nature comes from the lab microevents (detectorclicks) being formalized into the Ccoefficients

Highfrequency homogenization in periodic media with imperfect interfaces Proc. Royal Soc. A: Math. Phys. Eng. Sci. (IF 2.741) Pub Date : 20201216
Raphal C. Assier; Marie Touboul; Bruno Lombard; Cdric BellisIn this work, the concept of highfrequency homogenization is extended to the case of onedimensional periodic media with imperfect interfaces of the springmass type. In other words, when considering the propagation of elastic waves in such media, displacement and stress discontinuities are allowed across the borders of the periodic cell. As is customary in highfrequency homogenization, the homogenization

Control of connectivity and rigidity in prismatic assemblies Proc. Royal Soc. A: Math. Phys. Eng. Sci. (IF 2.741) Pub Date : 20201216
Gary P. T. Choi; Siheng Chen; Lakshminarayanan MahadevanHow can we manipulate the topological connectivity of a threedimensional prismatic assembly to control the number of internal degrees of freedom and the number of connected components in it? To answer this question in a deterministic setting, we use ideas from elementary number theory to provide a hierarchical deterministic protocol for the control of rigidity and connectivity. We then show that it

Plasmonic modes in cylindrical nanoparticles and dimers Proc. Royal Soc. A: Math. Phys. Eng. Sci. (IF 2.741) Pub Date : 20201216
Charles A. Downing; Guillaume WeickWe present analytical expressions for the resonance frequencies of the plasmonic modes hosted in a cylindrical nanoparticle within the quasistatic approximation. Our theoretical model gives us access to both the longitudinally and transversally polarized dipolar modes for a metallic cylinder with an arbitrary aspect ratio, which allows us to capture the physics of both plasmonic nanodisks and nanowires

Nonlinear generalized functions on manifolds Proc. Royal Soc. A: Math. Phys. Eng. Sci. (IF 2.741) Pub Date : 20201216
E. A. Nigsch; J. A. VickersIn this work, we adopt a new approach to the construction of a global theory of algebras of generalized functions on manifolds based on the concept of smoothing operators. This produces a generalization of previous theories in a form which is suitable for applications to differential geometry. The generalized Lie derivative is introduced and shown to extend the Lie derivative of Schwartz distributions

A nonlinear theory of distributional geometry Proc. Royal Soc. A: Math. Phys. Eng. Sci. (IF 2.741) Pub Date : 20201216
E. A. Nigsch; J. A. VickersThis paper builds on the theory of nonlinear generalized functions begun in Nigsch & Vickers (Nigsch, Vickers 2021 Proc. R. Soc. A 20200640 (doi:10.1098/rspa.2020.0640)) and extends this to a diffeomorphisminvariant nonlinear theory of generalized tensor fields with the sheaf property. The generalized Lie derivative is introduced and shown to commute with the embedding of distributional tensor fields

Fibrous gels modelled as fluidfilled continua with doublewell energy landscape Proc. Royal Soc. A: Math. Phys. Eng. Sci. (IF 2.741) Pub Date : 20201216
Chuanpeng Sun; Irina N. Chernysh; John W. Weisel; Prashant K. PurohitSeveral biological materials are fibre networks infused with fluid, often referred to as fibrous gels. An important feature of these gels is that the fibres buckle under compression, causing a densification of the network that is accompanied by a reduction in volume and release of fluid. Displacementcontrolled compression of fibrous gels has shown that the network can exist in a rarefied and a densified

A duality between scattering poles and transmission eigenvalues in scattering theory Proc. Royal Soc. A: Math. Phys. Eng. Sci. (IF 2.741) Pub Date : 20201216
Fioralba Cakoni; David Colton; Houssem HaddarIn this paper, we develop a conceptually unified approach for characterizing and determining scattering poles and interior eigenvalues for a given scattering problem. Our approach explores a duality stemming from interchanging the roles of incident and scattered fields in our analysis. Both sets are related to the kernel of the relative scattering operator mapping incident fields to scattered fields

Macroscopic permeability of doubly porous solids with spheroidal macropores: closedform approximate solutions of the longitudinal permeability Proc. Royal Soc. A: Math. Phys. Eng. Sci. (IF 2.741) Pub Date : 20201209
Vincent monchietThe presence of macropores and fractures significantly affects the effective transport properties of porous solids such as concrete and rocks. The dimensions of the fractures are generally large behind that of the initial porosity, so that the problem contains two porosities. The influence of the macroporosity is studied in the homogenization framework by solving at the intermediate scale, that of

Dynamics of a waveboard simplified Proc. Royal Soc. A: Math. Phys. Eng. Sci. (IF 2.741) Pub Date : 20201209
Anirvan DasGuptaA study of dynamics of a waveboard is presented. The equations of motion are derived and analysed to understand the intriguing propulsion mechanism. A reduced order model is obtained, and the contributions of different terms are clearly brought out. The geometry of the castor wheels is found to play a key role in the conversion of the twisting oscillatory motion of the rider to the forward translational

A revisit of the tonal noise of small rotors Proc. Royal Soc. A: Math. Phys. Eng. Sci. (IF 2.741) Pub Date : 20201209
Siyang Zhong; Peng Zhou; Ryu Fattah; Xin ZhangIn this study, asymptotic analysis of the frequencydomain formulation to compute the tonal noise of the small rotors in the now ubiquitously multirotor powered drones is conducted. Simple scaling laws are proposed to evaluate the impacts of the influential parameters such as blade number, flow speed, rotation speed, unsteady motion, thrust and observer angle on the tonal noise. The rate of noise

Nonreciprocal acoustics in a viscous environment Proc. Royal Soc. A: Math. Phys. Eng. Sci. (IF 2.741) Pub Date : 20201209
Hyeonu Heo; Ezekiel Walker; Yurii Zubov; Dmitrii Shymkiv; Dylan Wages; Arkadii Krokhin; TaeYoul Choi; Arup NeogiIt is demonstrated that acoustic transmission through a phononic crystal with anisotropic solid scatterers becomes nonreciprocal if the background fluid is viscous. In an ideal (inviscid) fluid, the transmission along the direction of broken P symmetry is asymmetric. This asymmetry is compatible with reciprocity since timereversal symmetry (T symmetry) holds. Viscous losses break T symmetry, adding

Maxwell's quasidemon as a property of an ideal gas in the equilibrium state Proc. Royal Soc. A: Math. Phys. Eng. Sci. (IF 2.741) Pub Date : 20201202
Andrey V. SemikolenovThe paper shows that for the case of an ideal gas in the equilibrium state there exists a method for splitting it into portions with different temperatures without energy transfer to or from the environment and without work being done. Compared with the thought experiment known as ‘Maxwell's demon’, in which such splitting is based on sorting specific molecules according to their energy levels, the

Superdeterministic hiddenvariables models II: conspiracy Proc. Royal Soc. A: Math. Phys. Eng. Sci. (IF 2.741) Pub Date : 20201125
Indrajit Sen; Antony ValentiniWe prove that superdeterministic models of quantum mechanics are conspiratorial in a mathematically welldefined sense, by further development of the ideas presented in a previous article A. We consider a Bell scenario where, in each run and at each wing, the experimenter chooses one of N devices to determine the local measurement setting. We prove, without assuming any features of quantum statistics

Analysis of node2vec random walks on networks Proc. Royal Soc. A: Math. Phys. Eng. Sci. (IF 2.741) Pub Date : 20201125
Lingqi Meng; Naoki MasudaRandom walks have been proven to be useful for constructing various algorithms to gain information on networks. Algorithm node2vec employs biased random walks to realize embeddings of nodes into lowdimensional spaces, which can then be used for tasks such as multilabel classification and link prediction. The performance of the node2vec algorithm in these applications is considered to depend on properties

Environmental sustainability of biofuels: a review Proc. Royal Soc. A: Math. Phys. Eng. Sci. (IF 2.741) Pub Date : 20201125
Harish K. Jeswani; Andrew Chilvers; Adisa AzapagicBiofuels are being promoted as a lowcarbon alternative to fossil fuels as they could help to reduce greenhouse gas (GHG) emissions and the related climate change impact from transport. However, there are also concerns that their wider deployment could lead to unintended environmental consequences. Numerous life cycle assessment (LCA) studies have considered the climate change and other environmental

Oscillatory dynamics in the dilemma of social distancing Proc. Royal Soc. A: Math. Phys. Eng. Sci. (IF 2.741) Pub Date : 20201125
Alina Glaubitz; Feng FuSocial distancing as one of the main nonpharmaceutical interventions can help slow down the spread of diseases, like in the COVID19 pandemic. Effective social distancing, unless enforced as drastic lockdowns and mandatory cordon sanitaire, requires consistent strict collective adherence. However, it remains unknown what the determinants for the resultant compliance of social distancing and their

Electrocharged facepiece respirator fabrics using common materials Proc. Royal Soc. A: Math. Phys. Eng. Sci. (IF 2.741) Pub Date : 20201125
M. M. BandiFace masks in general, and N95 filtering facepiece respirators (FRs) that protect against SARSCov2 virion in particular, have become scarce during the ongoing COVID19 global pandemic. This work presents practical design principles for the fabrication of electrocharged filtration layers employed in N95 FRs using commonly available materials and easily replicable methods. The input polymer is polypropylene

An improved statistical approach for reconstructing past climates from biotic assemblages Proc. Royal Soc. A: Math. Phys. Eng. Sci. (IF 2.741) Pub Date : 20201125
Mengmeng Liu; Iain Colin Prentice; Cajo J. F. ter Braak; Sandy P. HarrisonQuantitative reconstructions of past climates are an important resource for evaluating how well climate models reproduce climate changes. One widely used statistical approach for making such reconstructions from fossil biotic assemblages is weighted averaging partial leastsquares regression (WAPLS). There is however a known tendency for WAPLS to yield reconstructions compressed towards the centre

Diffraction by a rigid strip in a plate modelled by Mindlin theory Proc. Royal Soc. A: Math. Phys. Eng. Sci. (IF 2.741) Pub Date : 20201125
Ian ThompsonWe consider a plane flexural wave incident on a semiinfinite rigid strip in a Mindlin plate. The boundary conditions on the strip lead to three Wiener–Hopf equations, one of which decouples, leaving a scalar problem and a 2 × 2 matrix problem. The latter is solved using a simple method based on quadrature. The farfield diffraction coefficient is calculated and some numerical results are presented

On the accuracy and applicability of a new implicit Taylor method and the highorder spectral method on steady nonlinear waves Proc. Royal Soc. A: Math. Phys. Eng. Sci. (IF 2.741) Pub Date : 20201125
Mathias Klahn; Per A. Madsen; David R. FuhrmanThis paper presents an investigation and discussion of the accuracy and applicability of an implicit Taylor (IT) method versus the classical higherorder spectral (HOS) method when used to simulate twodimensional regular waves. This comparison is relevant, because the HOS method is in fact an explicit perturbation solution of the IT formulation. First, we consider the Dirichlet–Neumann problem of

Mixedprecision iterative refinement using tensor cores on GPUs to accelerate solution of linear systems Proc. Royal Soc. A: Math. Phys. Eng. Sci. (IF 2.741) Pub Date : 20201125
Azzam Haidar; Harun Bayraktar; Stanimire Tomov; Jack Dongarra; Nicholas J. HighamDoubleprecision floatingpoint arithmetic (FP64) has been the de facto standard for engineering and scientific simulations for several decades. Problem complexity and the sheer volume of data coming from various instruments and sensors motivate researchers to mix and match various approaches to optimize compute resources, including different levels of floatingpoint precision. In recent years, machine

A fundamental class of stress elements in lower bound limit analysis Proc. Royal Soc. A: Math. Phys. Eng. Sci. (IF 2.741) Pub Date : 20201125
Athanasios MakrodimopoulosThere is a major restriction in the formulation of rigorous lower bound limit analysis by means of the finiteelement method. Once the stress field has been discretized, the yield criterion and the equilibrium conditions must be applied at a finite number of points so that they are satisfied everywhere throughout the discretized structure. Until now, only the linear stress elements fulfil this requirement

On relativistic gasdynamics: invariance under a class of reciprocaltype transformations and integrable Heisenberg spin connections Proc. Royal Soc. A: Math. Phys. Eng. Sci. (IF 2.741) Pub Date : 20201125
C. Rogers; T. Ruggeri; W. K. SchiefA classical system of conservation laws descriptive of relativistic gasdynamics is examined. In the twodimensional stationary case, the system is shown to be invariant under a novel multiparameter class of reciprocal transformations. The class of invariant transformations originally obtained by Bateman in nonrelativistic gasdynamics in connection with lift and drag phenomena is retrieved as a reduction

Shearlets as feature extractor for semantic edge detection: the modelbased and datadriven realm Proc. Royal Soc. A: Math. Phys. Eng. Sci. (IF 2.741) Pub Date : 20201125
Hctor AndradeLoarca; Gitta Kutyniok; Ozan ktemSemantic edge detection has recently gained a lot of attention as an imageprocessing task, mainly because of its wide range of realworld applications. This is based on the fact that edges in images contain most of the semantic information. Semantic edge detection involves two tasks, namely pure edge detection and edge classification. Those are in fact fundamentally distinct in terms of the level

Analytic and numerical solutions to the seismic wave equation in continuous media Proc. Royal Soc. A: Math. Phys. Eng. Sci. (IF 2.741) Pub Date : 20201125
S. J. Walters; L. K. Forbes; A. M. ReadingThis paper presents two approaches to mathematical modelling of a synthetic seismic pulse, and a comparison between them. First, a new analytical model is developed in twodimensional Cartesian coordinates. Combined with an initial condition of sufficient symmetry, this provides a valuable check for the validity of the numerical method that follows. A particular initial condition is found which allows

Bayesian differential programming for robust systems identification under uncertainty Proc. Royal Soc. A: Math. Phys. Eng. Sci. (IF 2.741) Pub Date : 20201125
Yibo Yang; Mohamed Aziz Bhouri; Paris PerdikarisThis paper presents a machine learning framework for Bayesian systems identification from noisy, sparse and irregular observations of nonlinear dynamical systems. The proposed method takes advantage of recent developments in differentiable programming to propagate gradient information through ordinary differential equation solvers and perform Bayesian inference with respect to unknown model parameters