A supervised similarity measure for link prediction based on KNN

As a research hotspot of complex network analysis, link prediction has received growing attention from various disciplines. Link prediction intends to determine the connecting probability of latent links based on the observed structure information. To this end, a host of similarity-based and learning-based link prediction methods have been proposed. To attain stable prediction performance on diverse networks, this paper proposes a supervised similarity-based method, which absorbs the advantages of both kinds of link prediction methods. In the proposed method, to capture the characteristics of a node pair, a collection of structural features is extracted from the network to represent the node pair as a vector. Then, the positive and negative [Formula: see text]-nearest neighbors are searched from existing and nonexisting links, respectively. The connection likelihood of a node pair is measured according to its distances to the local mean vectors of positive and negative [Formula: see text]-nearest neighbors. The prediction performance of the proposed method is experimentally evaluated on 10 benchmark networks. The results show that the proposed method is superior to the compared methods in terms of accuracy and stableness.

Tailorable epsilon-negative and epsilon-near-zero behavior of TiC/CCTO metacomposites: Low-frequency plasma oscillation

Epsilon-negative ([Formula: see text]) and epsilon-near-zero (ENZ) property was demonstrated in titanium carbide/copper calcium titanate (TiC/CCTO) metacomposites. Benefiting from the moderate concentration of free electrons in TiC filler and its adjustable three-dimensional (3D) networks, weakly negative permittivity ([Formula: see text]200 at 20 MHz) was achieved. Not only that, tailoring the negative permittivity of metacomposites from [Formula: see text]200 to [Formula: see text]2060, [Formula: see text]4200, [Formula: see text]14000 and [Formula: see text]70000 at 20 MHz was realized by simply increasing TiC content. Besides, Drude model was used to explain the radio-frequency (RF) negative permittivity and quantified the collective plasma oscillation in TiC networks.

On factorizations into coprime parts

Let [Formula: see text] and [Formula: see text] be the number of unordered and ordered factorizations of [Formula: see text] into integers larger than one. Let [Formula: see text] and [Formula: see text] have the additional restriction that the factors are coprime. We establish asymptotic bounds for the sums of [Formula: see text] and [Formula: see text] up to [Formula: see text] for all real [Formula: see text] and the asymptotic bounds for [Formula: see text] and [Formula: see text] for all negative [Formula: see text].

Prediction of Vibration Velocity of Bench Blasting Reflecting Negative Elevation Effect

In the field of mine blasting practice, accurate prediction of blasting vibration is considered as a critical task. In accordance with the theory of elastic wave, the reflection of blasting vibration wave at the interface of negative elevation is analyzed in this paper. The negative elevation effect exerted by blasting vibration is interpreted considering the mechanism, and the formula of the blasting vibration prediction step (negative) V = K Q 1 / 3 / R α ⋅ 1 / H β is derived, reflecting the negative elevation effect. Besides, the formula accuracy is verified by the measured vibration velocity of the mass in the Jinou coal mine. The step (negative) formula acts as a more feasible candidate for the prediction of step blasting vibration.

Waveform-based estimation of Q and scattering properties for zero-offset vertical seismic profile data

Estimating [Formula: see text] using downgoing waves in zero-offset vertical seismic profiles (VSPs) can be challenging when scattered waves from near-borehole heterogeneities interfere with direct arrivals. In any [Formula: see text] estimation method that assumes a downgoing plane wave, constructive and destructive wave-mode interference can cause errors in the estimate. For example, in the spectral-ratio method, such interference modulates the amplitude spectra introducing significant variations and even nonphysical negative [Formula: see text] (amplification) estimates. We have investigated this phenomenon using synthetic and field data sets from offshore Australia and developed a two-step waveform-based method to characterize scattering anomalies and improve [Formula: see text] estimates. Waveform information is key to deal with closely spaced band-limited seismic events. First, we solve an inverse problem to locate and characterize scatterers by minimizing the traveltime and waveform misfits. Then, using the estimated parameters, we model the scatterers’ contribution to the VSP data and remove it from the observed waveforms. The resulting spectra resemble those that would have been acquired in the absence of the scatterers and are much more suitable for the spectral-ratio method. By assuming a 1D medium and a simple scatterer shape (i.e., circular), we parameterize a scattering heterogeneity using five parameters (depth, distance, size, velocity, and density) and seek a solution using a grid search to handle the nonuniqueness of the VSP inversion. Instead, adaptive subtraction is required to fine-tune the modeled interference to better fit the observation. We successfully use this method to characterize and mitigate the strongest wave interference in the field data. The final [Formula: see text] estimates contain milder variations and much less nonphysical negative [Formula: see text]. Our results demonstrate that the proposed method, readily extendible to multiple scatterer cases, can locate discrete scatterers, remove the effects of their interference, and thus significantly improve the [Formula: see text] estimates from VSP data.

Negative imaginary component of AC magnetic susceptibility, metastable states, and magnetic relaxation in La0.6Sr0.35MnTi0.05O3

Off-stoichiometric ([Formula: see text][Formula: see text])([Formula: see text]) MnO3 manganite was studied with in-phase (real, [Formula: see text]) and out-of-phase (imaginary, [Formula: see text]) components of ac susceptibility measurements. Short- and long-time relaxation effects, manifested by the revealed negative [Formula: see text], were observed. The effects are explained at the frame of Landau theory of phase transitions where a coexistence of stable and metastable states is considered. It is supposed that the appearance of negative [Formula: see text] is an intrinsic feature of magnetic materials with impurities, defects and vacancies blocking nucleation and growth of new phase.

Quasi-periodic solutions of the negative-order Jaulent–Miodek hierarchy

A uniform construction of quasi-periodic solutions to the negative-order Jaulent–Miodek (nJM) hierarchy is presented by using a family of backward Neumann type systems. From the backward Lenard gradients, the nJM hierarchy is put into the zero-curvature setting and the bi-Hamiltonian structure displaying its integrability. The nonlinearization of Lax pair is generalized to the nJM hierarchy such that it can be reduced to a sequence of backward Neumann type systems, whose involutive solutions yield finite parametric solutions of the nJM hierarchy. The negative [Formula: see text]-order stationary JM equation is given to specify a finite-dimensional invariant subspace for the nJM flows. With a spectral curve determined by the Lax matrix, the nJM flows are linearized on the Jacobi variety of a Riemann surface. Finally, the Riemann–Jacobi inversion is applied to Abel–Jacobi solutions of the nJM flows, by which some quasi-periodic solutions are obtained for the nJM hierarchy.

On the vanishing of relative negative K-theory

In this paper, we study the relative negative [Formula: see text]-groups [Formula: see text] of a map [Formula: see text] of schemes. We prove a relative version of Weibel’s conjecture; i.e. if [Formula: see text] is a smooth affine map of Noetherian schemes with [Formula: see text], then [Formula: see text] for [Formula: see text] and the natural map [Formula: see text] is an isomorphism for all [Formula: see text] and [Formula: see text] We also prove a vanishing result for relative negative [Formula: see text]-groups of a subintegral map.

Effective action study of the 𝒫𝒯-symmetric (iϕ3)6−𝜖 theory and the Yang–Lee edge singularity

We use the effective potential method to study the [Formula: see text]-symmetric [Formula: see text] field theory in [Formula: see text] space–time dimensions. For [Formula: see text], we obtained the first two energy levels which are real as well as reflecting the stability of the spectrum. [Formula: see text]-symmetry breaking occurs at [Formula: see text] where the two levels merge and beyond this critical point they have complex values. Since there exist no results in the literature to compare with, we extracted the critical exponents of the theory to test the accuracy of our calculations where we find them agree with exact results from the literature. We showed that the critical point is in fact a Yang–Lee edge singularity which is the first time to link [Formula: see text]-symmetry breaking to the existence of a Yang–Lee edge singularity. For [Formula: see text], the fixed point is nontrivial and exists for negative [Formula: see text] values as expected from Yang–Lee theory for ferromagnetic systems.

Shakespeare’s Montaigne: Maps and Books in The Tempest

Frank Lestringant’s chapter focuses on knowledge and Renaissance discoveries. It examines how the playwright used books and maps—geometry being part of the medieval quadrivium—and how he reassessed their functions. In The Tempest, Lestringant once more reminds us that Shakespeare skilfully relies on Montaigne’s Essays and cleverly re-appropriates the negative formula of the essay entitled “Of Cannibals”. Indeed, Gonzalo’s famous tirade, in act 2, scene 1, is drawn from Montaigne’s chapter on cannibals, translated by John Florio in 1603. Commenting on this almost-literal and well-known borrowing, Lestringant shows how Shakespeare manages to dramatize Montaigne’s observations and how he lionizes the old lord Gonzalo thanks to his indirect quote. Doing so, he reexamines Gonzalo’s role in The Tempest and rehabilitates his humanist education.