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Radiofrequency (RF) has been widely used as a noninvasive technique for skin tightening and rejuvenation. Moiré is a type of interference pattern corresponding to the shape of the face. We aimed to objectively evaluate the effect of RF on facial skin laxity using moiré. Ten subjects participated and were treated with a monopolar RF on the face. Clinical photographs and moiré images were obtained at the baseline and after treatment. The periorbital angle from the upper third of the face, zygomatic length ratio (L1/L2), angle from the middle third, perioral perpendicular length, and angle from the lower third were analyzed. After one session of RF treatment, the mean zygomatic length ratio (L1/L2) from the middle third of the face significantly increased in the 4th week (by 49.68%, P =.047). The L1/L2 ratio increased to nearly one, which were not significant after 8 weeks. The mean perioral perpendicular length decreased to 282.25 ± 84.069 pixels (px) after 4 weeks, and to 281.38 ± 76.03 px after 24 weeks; these differences were statistically significant. The parameters of zygomatic length ratio and perioral perpendicular length extracted from illuminated moiré images can be useful for objectively assessing various facial tightening treatments in clinical settings. [ABSTRACT FROM AUTHOR]

In a previous recent paper we discussed the limitations of the Fourier-based model in the prediction of visible moire effects. Here, we extend the discussion to other mathematical models that are also being used in the moire theory: the classical indicial equations method for modelling the moire fringes between periodic or curvilinear gratings, and two methods that are used to model different facets of the moire effects between correlated aperiodic layers. We discuss the limitations of each model, explain their significance, and suggest possible ways to overcome them. [ABSTRACT FROM AUTHOR]

High-speed photography has been used in Cambridge to study dynamic events since the 1940s. In the early years, Courtney-Pratt both developed and used such cameras. More recently, there has been interaction between camera manufacturers and the Cavendish, but the main emphasis has been on using high-speed photographic techniques to obtain data on explosive ignition and propagation, fracture and impact processes. In many situations, it is important to acquire data at both high time and high spatial resolution. Optical techniques which allow this are reviewed. Most recently, the interest has been in obtaining data from inside solids, including opaque ones. This has been made possible by fabricating samples to include a random array of dense particles on a plane within a specimen and then obtaining images using X-rays. [ABSTRACT FROM AUTHOR]

Modern moire theory is largely based on the Fourier approach. And yet, it seems that the Fourier theory by itself cannot answer all questions related to moire effects. We present some visible phenomena in the superposition of periodic structures (such as line gratings) that are not captured by the Fourier approach. We discuss their significance, and provide possible explanations. In particular, we introduce the infinite module spanned by the frequencies of the original individual layers as a main tool in the moire theory. We discuss its significance on the visible periodicities in the layer superposition-either real moire effects, or pseudo-moire (modulation) effects having no corresponding impulses in the Fourier spectral domain. [ABSTRACT FROM AUTHOR]

This paper describes a simple method for making extended fractional Fourier transform (EFRT) based Moiré pattern encoded security holograms. These security holograms contain multifold concealed and encoded anticounterfeit security features that can only be read through a key hologram and periodic patterns in the final reading process. The encoded features in these holograms are concealed and unknown to the counterfeiter. These features are encoded separately for each individual recording in angularly multiplexed extended fractional Fourier transform hologram (EFRTH). The principle of recording and reconstruction of the proposed security hologram along with experimental results are presented. [ABSTRACT FROM AUTHOR]