arXiv subjects

Yavar Khedmati

Publications and source records attributed to Yavar Khedmati.

5 recordsLinked to original sources

arXiv2021

A hybrid chaos map with two control parameters to secure image encryption algorithms

In this paper, we introduce a hybrid chaos map for image encryption method with high sensitivity. This new map is sensitive to small changes in the starting point and also in control parameters which result in having more computational complexity. Also, it has uniform distribution that provides resisting of the new system against attacks in security applications. Various tests and plots are demonstrated to show more chaotic behavior of the proposed system. Finally, to show the ability of the generated chaotic map in the existences image cryptography approaches, we further report some results in this area.

cs.CR↗

arXiv2020

Properties of bounded representations for $G$-frames

Due to the importance of frame representation by a bounded operator in dynamical sampling, researchers studied the frames of the form $\{T^{i-1} f\}_{i\in \mathbb{N}}$, which $f$ belongs to separable Hilbert space $\mathcal{H}$ and $T\in B(\mathcal{H})$, and investigated the properties of $T$. Given that $g$-frames include the wide range of frames such as fusion frames, the main purpose of this paper is to study the characteristics of the operator $T$ for $g$-frames of the form $\{ΛT^{i-1} \in B(\mathcal{H},\mathcal{K}):i\in \mathbb{N}\}$.

math.FA↗

arXiv2018

g-frame representations with bounded operators

Dynamical sampling, as introduced by Aldroubi et al., deals with frame properties of sequences of the form $\{T^i f_1\}_{i\in \mathbb{N}}$, where $f_1$ belongs to Hilbert space $\h$ and $T:\h\rightarrow\h$ belongs to certain classes of the bounded operators. Christensen et al., study frames for $\h$ with index set $\mathbb{N}$ (or $\mathbb{Z}$), that have representations in the form $\{T^{i-1}f_1\}_{i\in \mathbb{N}}$ (or $\{T^if_0\}_{i\in \mathbb{Z}}$). As frames of subspaces, fusion frames and generalized translation invariant systems are the spacial cases of $g$-frames, the purpose of this paper is to study $g$-frames $Λ=\{Λ_i\in B(\h,\K): i\in I\}$ $(I=\mathbb{N}$ or $\mathbb{Z}$) having the form $Λ_{i+1}=Λ_1 T^{i},$ for $T\in B(\h).$

math.FA↗

arXiv2018

Disjointness of continuous g-frames and Riesz-type continuous g-frames

In this paper we introduce concepts of disjoint, strongly disjoint and weakly disjoint continuous $g$-frames in Hilbert spaces and we get some equivalent conditions to these notions. We also construct a continuous g-frame by disjoint continuous g-frames. Furthermore, we provide some results related to the Riesz-type continuous $g$-frames.

math.FA↗

arXiv2018

Invertibility of Multipliers for Continuous G-frames

In this paper we study the concept of multipliers for continuous $g$-Bessel families in Hilbert spaces. We present necessary conditions for invertibility of multipliers for continuous $g$-Bessel families and sufficient conditions for invertibility of multipliers for continuous $g$-frames.

math.FA↗