# Ali ShakibaVali-e-Asr University Of Rafsanjan | VRU · Department of Computer Sciences

Ali Shakiba

Ph.D. in Computer Science

## About

34

Publications

3,448

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256

Citations

Introduction

I am an assistant professor of computer science at Vali-e-Asr university of Rafsanjan, Iran. My research interests include Big data models and algorithms, post-quantum cryptosystems, approximate reasoning and scientific computing. Before joining the VRU as a faculty, I have spent 5 years and a half at Yazd university to obtain my PhD and MSc degrees and 4 years at Shahid Bahonar university of Kerman to do my BSc, all in computer science. More on http://1ali.ir

**Skills and Expertise**

Additional affiliations

April 2018 - present

September 2016 - present

September 2016 - present

Education

September 2012 - February 2016

September 2010 - August 2012

September 2006 - August 2010

## Publications

Publications (34)

In this paper, we investigate whether consistent mappings can be used as homomorphism mappings between a covering based approximation space and its image with respect to twenty-two pairs of covering upper and lower approximation operators. We also consider the problem of constructing such mappings and minimizing them. In addition, we investigate th...

In this paper, we will study neighborhood system S-approximation spaces, i.e., combination of S-approximation spaces with identical elements except that they have different knowledge mappings, e.g., the knowledge mappings differ due to different experimental conditions and/or sampling methodology. In such situations, there is a risk of contradictor...

In this paper, we investigate properties of the lower and upper approximations of an S-approximation space under different assumptions for its S operator. These assumptions are partial monotonicity, complement compatibility and functional partial monotonicity. We also extend the theory of three way decisions to non-inclusion relations. Also in this...

In this paper, we will investigate the concept of intuitionistic fuzzy S-approximation spaces. This concept can be employed to manage the uncertainty in the intuitionistic fuzzy problems which are not expressible in terms of intuitionistic fuzzy inclusion relations. Also, we have studied these structures from a three-way decisions approach. The mon...

In this work, we propose a class of public-key cryptosystems called multiplicative coupled cryptosystem, or MCC for short, as well as discuss its security within three different models. Moreover, we discuss a chaotic instance of MCC based on the first and the second types of Chebyshev polynomials over real numbers for these three security models. T...

A set $D \subseteq V$ of a graph $G = (V,E)$ is called an outer-connected dominating set of $G$ if every vertex $v$ not in $D$ is adjacent to at least one vertex in $D$, and the induced subgraph of $G$ on $V \setminus D$ is connected. The Minimum Outer-connected Domination problem is to find an outer-connected dominating set of minimum cardinality...

Given a positive integer k and a graph G = (V, E), a function f from V to the power set of Ik is called a k-rainbow function if for each vertex v ∈ V, f(v)=∅ implies ∪u ∈ N(v)f(u)=Ik where N(v) is the set of all neighbors of vertex v and Ik = {1, …, k}. Finding a k-rainbow function of minimum weight of ∑v ∈ V|f(v)|, which is called the k-rainbow do...

In this paper, we design a novel two-dimensional hyperchaotic with two positive Lyapunov exponents and a phase distribution region close to uniform. Then, we propose a novel randomized hyperchaotic image encryption algorithm based on the proposed two-dimensional hyperchaotic mapping. The algorithm is designed in such a way that first adds randomiza...

The combination of identical S-approximation spaces, except with different decider mappings, is studied in this paper by considering the construction of more complex S-approximation spaces from simpler ones that use different decision criteria, e.g., due to levels of expertise. It can be used to model group decision making problems where each decid...

In this paper, we build a novel chaotic coupled lattice mapping with positive Lyapunov exponent, and introduce a novel chaotic image scrambling mechanism. Then, we propose a chaotic image encryption algorithm which uses the introduced chaotic coupled lattice mapping to apply permutation by iteratively applying the introduced chaotic image scramblin...

In this paper, we designed a new hyperchaotic two-dimensional map with wide distribution and two large positive Lyapunov exponents. Then, we used it to construct a new randomized bit-level chaotic image encryption algorithm with the proposed hyperchaotic map as the source of randomization for permutation and diffusion. The input image is randomized...

We construct a novel randomized chaotic image encryption algorithm based on the one-dimensional chaotic Chebyshev mappings. We first define a novel chaotic breadth-first search algorithm and then use it to apply the permutation to image pixels. We also use a novel approach to construct the diffusion matrix using a chaotic sequence. Using a one-dime...

The authentication of mobile users and establishing a shared key for wireless networks is becoming more emerging, as the number of users who want to roam into a foreign network to use a service increases as well as the increase in the number of such networks. Recently, a number of such protocols are proposed which their security rely on modular exp...

Highlights: • A novel chaotic asymmetric-key color image encryption algorithm is proposed. • The multiplicative coupled Chebyshev-based encryption scheme allows arbitrary sizes of keyspace. • One pixel may appear in any position throughout the image. • The proposed technique uses tries to achieve the benefits of the one-time pad. Abstract: In this...

In this paper, the concept of S-approximation spaces is surveyed at first and then, the combination of different S-approximation spaces with different decider mappings S is considered, i.e. combining S-approximation spaces G i = (U i , W i , T i , S i ) for i = 1, …, k. Moreover, the problem of preserving the corresponding properties of the lower a...

A set D V for the graph G = (V,E) is called a dominating set if any vertex v V \D has at least one neighbor in D. Fomin et al. [Combinatorial bounds via measure and conquer: Bounding minimal dominating sets and applications, ACM Transactions on Algorithms (TALG) 5(1) (2008) 9] gave an algorithm for enumerating all minimal dominating sets with n ver...

We study relations between evidence theory and S-approximation spaces. Both theories have their roots in the analysis of Dempster's multivalued mappings and lower and upper probabilities and have close relations to rough sets. We show that an S-approximation space, satisfying a monotonicity condition, can induce a natural belief structure which is...

A set $D \subseteq V$ for the graph $G=(V, E)$ is called a dominating set if any vertex $v\in V\setminus D$ has at least one neighbor in $D$. Fomin et al.[9] gave an algorithm for enumerating all minimal dominating sets with $n$ vertices in $O(1.7159^n)$ time. It is known that the number of minimal dominating sets for interval graphs and trees on $...

Let $G=(V,E)$ be a graph. A subset $S \subseteq V$ is a dominating set of $G$ if every vertex not in $S$ is adjacent to a vertex in $S$. A set $\tilde{D} \subseteq V$ of a graph $G=(V,E) $ is called an outer-connected dominating set for $G$ if (1) $\tilde{D}$ is a dominating set for $G$, and (2) $G [V \setminus \tilde{D}]$, the induced subgraph of...

In this paper, we propose two fuzzy clustering algorithms in the differential privacy scheme based on the fuzzy c-means algorithm. Up to the author's knowledge, these are the first algorithms of their kind which provide privacy for fuzzy data. Moreover, these two algorithms are experimentally compared with the original fuzzy algorithm and shown to...

An outer-connected dominating set for an arbitrary graph $G$ is a set $\tilde{D} \subseteq V$ such that $\tilde{D}$ is a dominating set and the induced subgraph $G [V \setminus \tilde{D}]$ be connected. In this paper, we focus on the outer-connected domination number of the product of graphs. We investigate the existence of outer-connected dominati...

A mixed dominating set $S$ of a graph $G=(V,E)$ is a subset $ S \subseteq V \cup E$ such that each element $v\in (V \cup E) \setminus S$ is adjacent or incident to at least one element in $S$. The mixed domination number $\gamma_m(G)$ of a graph $G$ is the minimum cardinality among all mixed dominating sets in $G$. The problem of finding $\gamma_{m...

A mixed dominating set for a graph $G = (V,E)$ is a set $S\subseteq V \cup E$ such that every element $x \in (V \cup E) \backslash S$ is either adjacent or incident to an element of $S$. The mixed domination number of a graph $G$, denoted by $\gamma_m(G)$, is the minimum cardinality of mixed dominating sets of $G$ and any mixed dominating set with...

In this paper, we study the concept of S-approximation spaces in fuzzy set theory and investigate its properties. Along introducing three pairs of lower and upper approximation operators for fuzzy S-approximation spaces, their properties under different assumptions, e.g. monotonicity and weak complement compatibility are studied. By employing two t...

In this paper, an efficient and accurate computational method based on the Legendre wavelets (LWs) together with the Galerkin method is proposed for solving a class of nonlinear stochastic Itô–Volterra integral equations. For this purpose, a new stochastic operational matrix (SOM) for LWs is derived. A collocation method based on hat functions (HFs...

In this paper, an efficient and accurate computational method based on the hat functions (HFs) is proposed for solving a class of fractional optimal control problems (FOCPs). In the proposed method, the fractional optimal control problem under consideration is reduced to a system of nonlinear algebraic equations which can be simply solved. To this...

An S-approximation space is a novel approach to study systems with uncertainty that are not expressible in terms of inclusion relations. In this work, we further examined these spaces, mostly from a topological point of view by a combinatorial approach. This work also identifies a subclass of these approximation spaces, called $S_\mathcal{MC}$-appr...

An S-approximation space is a novel approach to study systems with uncertainty that are not expressible in terms of inclusion relations. In this work, we further examined these spaces, mostly from a topological point of view by a combinatorial approach. This work also identifies a subclass of these approximation spaces, called $S_\mathcal{MC}$-appr...

We intend to study a new class of algebraic approximations, called S-approximations, and their properties. We have shown that S-approximations can be used for applied problems which cannot be modeled by inclusion based approximations. Also, in this work, we studied a subclass of S-approximations, called S ℳ -approximations, and showed that this sub...

## Projects

Projects (3)

In this project, we study the properties and applications of chaos in cryptographic protocols.

In this study, we are going to study different types of dominating sets in different classes of graphs from an algorithmic perspective such as approximation algorithms, fixed-parameter tractability and hardness results.