We prove that the zero divisor problem is equivalent to some problem about subgroups of a free group.

Guided waves in a free isotropic plate (symmetric S(n) and antisymmetric A(n) Lamb modes) exhibit a resonant behavior at frequencies where their group velocity vanishes while their phase velocity remains finite. Previous studies of this phenomenon were limited to isotropic materials. In this paper, the optical generation and detection of these zero-group velocity (ZGV) Lamb modes in an anisotro...

Let G = (V, E) be an oriented graph whose edges are labelled by the elements of a group Γ. A cycle C in G has non-zero weight if for a given orientation of the cycle, when we add the labels of the forward directed edges and subtract the labels of the reverse directed edges, the total is non-zero. We are specifically interested in the maximum number of vertex disjoint non-zero cycles. We prove t...

Asimple zero-knowledge proof of knowledge protocol is presented ofwhichmany known protocols are instantiations. These include Schnorr’s protocol for proving knowledge of a discrete logarithm, the Fiat–Shamir andGuillou–Quisquater protocols for proving knowledge of a modular root, protocols for proving knowledge of representations (like Okamoto’s protocol), protocols for proving equality of secr...

We examine differences between various zero-group-velocity modes in photonic crystals, including those that arise from Bragg diffraction, anticrossings, and band repulsion. Zero-group velocity occurs at points where the group velocity changes sign, and therefore is conceptually related to “left-handed” media, in which the group velocity is opposite to the phase velocity. We consider this relati...

We introduce a general notion of maturity in social networks that is based on the number of triangles between groups/communities. In order to protect individual privacy upon possible release of such information, we propose privacy mechanisms using zero-knowledge privacy (ZKP), a recently proposed privacy scheme that provides stronger protection than differential privacy (DP) for socialgraph dat...

Objectives: Among the most important problems of autistic children are the behavioral disorders due to sensory processing deficiency, which are typically reflected in behaviors such as impulsivity, attention and concentration disorders, undesirable emotional reactions, sensory seeking in the form of stereotype behaviors, self-injury and self-stimulating. The present study aimed at exploring the...

the aim of this cross sectional study was to determine anemias due to deficiency of iron,vitamin B12 and folate in pregnant women,who were refered to Shahid doctor mofateh hospital in varamin.in this study hemoglobin value(<11g/dl) was used as the determinant of anemia,therefore,the study was performed on 251 pregnant women.the proportions of women having abortions and cesarean sections were 10...