2021-10-20T22:04:50Z
https://scma.maragheh.ac.ir/?_action=export&rf=summon&issue=6622
Sahand Communications in Mathematical Analysis
SCMA
2322-5807
2322-5807
2020
17
3
Use of the Shearlet Transform and Transfer Learning in Offline Handwritten Signature Verification and Recognition
Atefeh
Foroozandeh
Ataollah
Askari Hemmat
Hossein
Rabbani
Despite the growing growth of technology, handwritten signature has been selected as the first option between biometrics by users. In this paper, a new methodology for offline handwritten signature verification and recognition based on the Shearlet transform and transfer learning is proposed. Since, a large percentage of handwritten signatures are composed of curves and the performance of a signature verification/recognition system is directly related to the edge structures, subbands of shearlet transform of signature images are good candidates for input information to the system. Furthermore, by using transfer learning of some pre-trained models, appropriate features would be extracted. In this study, four pre-trained models have been used: SigNet and SigNet-F (trained on offline signature datasets), VGG16 and VGG19 (trained on ImageNet dataset). Experiments have been conducted using three datasets: UTSig, FUM-PHSD and MCYT-75. Obtained experimental results, in comparison with the literature, verify the effectiveness of the presented method in both signature verification and signature recognition.
Offline handwritten signature
Signature verification
Signature recognition
Shearlet transform
Transfer learning
2020
07
01
1
31
https://scma.maragheh.ac.ir/article_38395_26252c7c74e40fc0b3676cf37cdf20eb.pdf
Sahand Communications in Mathematical Analysis
SCMA
2322-5807
2322-5807
2020
17
3
Weighted Composition Operators Between Extended Lipschitz Algebras on Compact Metric Spaces
Reyhaneh
Bagheri
Davood
Alimohammadi
In this paper, we provide a complete description of weighted composition operators between extended Lipschitz algebras on compact metric spaces. We give necessary and sufficient conditions for the injectivity and the sujectivity of these operators. We also obtain some sufficient conditions and some necessary conditions for a weighted composition operator between these spaces to be compact.
Compact operator
Extended Lipschitz algebra
Lipschitz mapping
Supercontactive mapping
Weighted composition operator
2020
07
01
33
70
https://scma.maragheh.ac.ir/article_39952_0926650acf7986aa5514b5750bfb1a7a.pdf
Sahand Communications in Mathematical Analysis
SCMA
2322-5807
2322-5807
2020
17
3
Strong Convergence of the Iterations of Quasi $phi$-nonexpansive Mappings and its Applications in Banach Spaces
Rasoul
Jahed
Hamid
Vaezi
Hossein
Piri
In this paper, we study the iterations of quasi $\phi$-nonexpansive mappings and its applications in Banach spaces. At the first, we prove strong convergence of the sequence generated by the hybrid proximal point method to a common fixed point of a family of quasi $\phi$-nonexpansive mappings. Then, we give applications of our main results in equilibrium problems.
Demiclosed
equilibrium problem
fixed point
hybrid projection
quasi nonexpansive mapping
Resolvent
2020
07
01
71
80
https://scma.maragheh.ac.ir/article_39052_05e6dbe42b5e8ba9e09f1c6d6e2559a5.pdf
Sahand Communications in Mathematical Analysis
SCMA
2322-5807
2322-5807
2020
17
3
Uniform Convergence to a Left Invariance on Weakly Compact Subsets
Ali
Ghaffari
Samaneh
Javadi
Ebrahim
Tamimi
Let $\left\{a_\alpha\right\}_{\alpha\in I}$ be a bounded net in a Banach algebra $A$ and $\varphi$ a nonzero multiplicative linear functional on $A$. In this paper, we deal with the problem of when $\|aa_\alpha-\varphi(a)a_\alpha\|\to0$ uniformly for all $a$ in weakly compact subsets of $A$. We show that Banach algebras associated to locally compact groups such as Segal algebras and $L^1$-algebras are responsive to this concept. It is also shown that $Wap(A)$ has a left invariant $\varphi$-mean if and only if there exists a bounded net $\left\{a_\alpha\right\}_{\alpha\in I}$ in $\left\{a\in A;\ \varphi(a)=1\right\}$ such that $\|aa_\alpha-\varphi(a)a_\alpha\|_{Wap(A)}\to0$ uniformly for all $a$ in weakly compact subsets of $A$. Other results in this direction are also obtained.
Banach algebra
$varphi$-amenability
$varphi$-means
Weak almost periodic
Weak$^*$ topology
2020
07
01
81
91
https://scma.maragheh.ac.ir/article_40529_52ec68cb33d86279de572c0696818129.pdf
Sahand Communications in Mathematical Analysis
SCMA
2322-5807
2322-5807
2020
17
3
On Some Characterization of Generalized Representation Wave-Packet Frames Based on Some Dilation Group
Atefe
Razghandi
Ali Akbar
Arefijamaal
In this paper we consider (extended) metaplectic representation of the semidirect product $G_{\mathbb{J}}=\mathbb{R}^{2d}\times\mathbb{J}$ where $\mathbb{J}$ is a closed subgroup of $Sp(d,\mathbb{R})$, the symplectic group. We will investigate continuous representation frame on $G_{\mathbb{J}}$. We also discuss the existence of duals for such frames and give several characterization for them. Finally, we rewrite the dual conditions, by using the Wigner distribution and obtain more reconstruction formulas.
Representation frames
Dilation groups
Dual frames
Continuous frames
2020
07
01
93
106
https://scma.maragheh.ac.ir/article_40531_27f20b771699ae668d315a11ac3e008e.pdf
Sahand Communications in Mathematical Analysis
SCMA
2322-5807
2322-5807
2020
17
3
About Subspace-Frequently Hypercyclic Operators
Mansooreh
Moosapoor
Mohammad
Shahriari
In this paper, we introduce subspace-frequently hypercyclic operators. We show that these operators are subspace-hypercyclic and there are subspace-hypercyclic operators that are not subspace-frequently hypercyclic. There is a criterion like to subspace-hypercyclicity criterion that implies subspace-frequent hypercyclicity and if an operator $T$ satisfies this criterion, then $T\oplus T$ is subspace-frequently hypercyclic. Additionally, operators on finite spaces can not be subspace-frequently hypercyclic.
Subspace-frequently hypercyclic operators
Subspace-hypercyclic operators
Frequently hypercyclic operators
Hypercyclic operators
2020
07
01
107
116
https://scma.maragheh.ac.ir/article_43323_c259331d9443082f0a692ce44718f592.pdf
Sahand Communications in Mathematical Analysis
SCMA
2322-5807
2322-5807
2020
17
3
On the Spaces of $lambda _{r}$-almost Convergent and $lambda _{r}$-almost Bounded Sequences
Sinan
Ercan
The aim of the present work is to introduce the concept of $\lambda _{r}$-almost convergence of sequences. We define the spaces $f\left( \lambda _{r}\right) $ and $f_{0}\left( \lambda _{r}\right) $ of $ \lambda _{r}$-almost convergent and $\lambda _{r}$-almost null sequences. We investigate some inclusion relations concerning those spaces with examples and we determine the $\beta $- and $\gamma $-duals of the space $f\left( \lambda _{r}\right) $. Finally, we give the characterization of some matrix classes.
Almost convergence
Matrix domain
$beta $-
$gamma $-duals
Matrix transformations
2020
07
01
117
130
https://scma.maragheh.ac.ir/article_40579_85759bdb155dcfb274e7ac69b0e053fb.pdf
Sahand Communications in Mathematical Analysis
SCMA
2322-5807
2322-5807
2020
17
3
Almost Multi-Cubic Mappings and a Fixed Point Application
Nasrin
Ebrahimi Hoseinzadeh
Abasalt
Bodaghi
Mohammad Reza
Mardanbeigi
The aim of this paper is to introduce $n$-variables mappings which are cubic in each variable and to apply a fixed point theorem for the Hyers-Ulam stability of such mapping in non-Archimedean normed spaces. Moreover, a few corollaries corresponding to some known stability and hyperstability outcomes are presented.
Multi-cubic mapping
Hyers-Ulam stability
Fixed point
non-Archimedean normed space
2020
07
01
131
143
https://scma.maragheh.ac.ir/article_40581_6b923b481dfe99fa2884509279aee928.pdf
Sahand Communications in Mathematical Analysis
SCMA
2322-5807
2322-5807
2020
17
3
Continuous $ k $-Frames and their Dual in Hilbert Spaces
Gholamreza
Rahimlou
Reza
Ahmadi
Mohammad Ali
Jafarizadeh
Susan
Nami
The notion of $k$-frames was recently introduced by G\u avru\c ta in Hilbert spaces to study atomic systems with respect to a bounded linear operator. A continuous frame is a family of vectors in a Hilbert space which allows reproductions of arbitrary elements by continuous super positions. In this manuscript, we construct a continuous $k$-frame, so called c$k$-frame along with an atomic system for this version of frames. Also we introduce a new method for obtaining the dual of a c$k$-frame and prove some new results about it.
c-frame
$K$-frame
c$K$-frame
c$k$-atom
c$k$-dual
2020
07
01
145
160
https://scma.maragheh.ac.ir/article_40583_8baad0d22b5a702687eb584294dd9657.pdf
Sahand Communications in Mathematical Analysis
SCMA
2322-5807
2322-5807
2020
17
3
$n$-factorization Property of Bilinear Mappings
Sedigheh
Barootkoob
In this paper, we define a new concept of factorization for a bounded bilinear mapping $f:X\times Y\to Z$, depended on a natural number $n$ and a cardinal number $\kappa$; which is called $n$-factorization property of level $\kappa$. Then we study the relation between $n$-factorization property of level $\kappa$ for $X^*$ with respect to $f$ and automatically boundedness and $w^*$-$w^*$-continuity and also strong Arens irregularity. These results may help us to prove some previous problems related to strong Arens irregularity more easier than old. These include some results proved by Neufang in ~\cite{neu1} and ~\cite{neu}. Some applications to certain bilinear mappings on convolution algebras, on a locally compact group, are also included. Finally, some solutions related to the Ghahramani-Lau conjecture is raised.
Bilinear map
Factorization property
Strongly Arens irregular
Automatically bounded and $w^*$-$w^*$-continuous
2020
07
01
161
173
https://scma.maragheh.ac.ir/article_40584_cbae0f5dc8463173efac6e2a2c9b9cae.pdf
Sahand Communications in Mathematical Analysis
SCMA
2322-5807
2322-5807
2020
17
3
Joint and Generalized Spectral Radius of Upper Triangular Matrices with Entries in a Unital Banach Algebra
Hamideh
Mohammadzadehkan
Ali
Ebadian
Kazem
Haghnejad Azar
In this paper, we discuss some properties of joint spectral {radius(jsr)} and generalized spectral radius(gsr) for a finite set of upper triangular matrices with entries in a Banach algebra and represent relation between geometric and joint/generalized spectral radius. Some of these are in scalar matrices, but some are different. For example for a bounded set of scalar matrices,$\Sigma$, $r_*\left(\Sigma\right)= \hat{r}\left(\Sigma\right)$, but for a bounded set of upper triangular matrices with entries in a Banach algebra($\Sigma$), $r_*\left(\Sigma\right)\neq\hat{r}\left(\Sigma\right)$. We investigate when the set is defective or not and equivalent properties for having a norm equal to jsr, too.
Banach algebra
Upper Triangular Matrix
Generalized Spectral Radius
Joint Spectral Radius
Geometric Joint Spectral Radius
2020
07
01
175
188
https://scma.maragheh.ac.ir/article_37420_7f123da849ba22fd0f27bd234a383849.pdf
Sahand Communications in Mathematical Analysis
SCMA
2322-5807
2322-5807
2020
17
3
On Fixed Point Results for Hemicontractive-type Multi-valued Mapping, Finite Families of Split Equilibrium and Variational Inequality Problems
Tesfalem Hadush
Meche
Habtu
Zegeye
In this article, we introduced an iterative scheme for finding a common element of the set of fixed points of a multi-valued hemicontractive-type mapping, the set of common solutions of a finite family of split equilibrium problems and the set of common solutions of a finite family of variational inequality problems in real Hilbert spaces. Moreover, the sequence generated by the proposed algorithm is proved to be strongly convergent to a common solution of these three problems under mild conditions on parameters. Our results improve and generalize many well-known recent results existing in the literature in this field of research.
Fixed point
multi-valued, hemicontractive-type, variational inequality, split equilibrium problems
strong convergence
Monotone mapping
2020
07
01
189
217
https://scma.maragheh.ac.ir/article_39955_fccbe118a27b5cd60bf3c5d750ffab92.pdf