Erosion is one of serious oral health problems among Japanese children. Some dentists argue that brushing just after food/drink intake induces enamel abrasion. Objectives of this study were to evaluate amount of calcium elution from bovine enamel due to single and short immersion into carbonated soft drink, to calculate depth of the eroded lesion, and to determine when to brush teeth after carb...

In this paper, the authors study compensation of high-power amplifier (HPA) non-linear distortion in multi-user (MU) massive multiple-input multiple-output (MIMO) systems and focus on uplink transmission, where base station (BS) uses a large antenna array. First, present iterative cancellation (NDIC) algorithm-based MMSE approximate message passing (AMP) at receiver level, order to estimate mit...

Acoustic echo cancellers in today' s speakerphones or video conferencing systems rely on the assumption of a linear echo path. Low-cost audio equipment or constraints of portable communication systems cause nonlinear distortions, which limit the echo return loss enhancement achievable by linear adaptation schemes. These distortions are a superposition of different effects, which can be modelled...

We introduce shortcut graphs and groups. Shortcut are in which cycles cannot embed without metric distortion. groups act properly cocompactly on graphs. These notions unify a surprisingly broad family of interest geometric group theory graph theory, including: the 1-skeletons systolic quadric complexes (in particular finitely presented C(6) C(4)-T(4) small cancellation groups), finite dimension...

Abstract This paper addresses the self-nulling phenomenon also known as self-cancellation in adaptive beamformers. Optimum beamforming requires knowledge of desired signal characteristics, either its statistics, direction-of-arrival, or response vector. Inaccuracies required information lead beamformer to attenuate if it were interference. Self-nulling is caused by having large power (high SNR)...

We study the Zariski cancellation problem for Poisson algebras in three variables. In particular, we prove those with bracket either being quadratic or derived from a Lie algebra are cancellative. also use various invariants, including Makar–Limanov invariant, divisor subalgebra, and stratiform length, to skew algebras.

Multi-stage high power amplifiers require more accurate behavioural models to provide a better description of memory effects and highly nonlinear characteristics than memoryless models based on single-tone transfer characteristics. This is achieved using measured two-tone transfer characteristics of the amplitude and phase of the fundamental, IM3 and IM5 componenls, which has highly nonlinear c...