Multi-depot Vehicle Routing Using Predictive Distributed Cooperative Method

, M.Sc. Thesis Sharif University of Technology Rahimi Baghbadorani, Reza (Author) ; Haeri, Mohammad (Supervisor)

Abstract

Due to conspicuous increases in shopping and goods transportation in this unbridled world, a significant part of companies’ final interest and final cost are related to their distributions of goods. Meanwhile, because of practical constraints of service hours and service distances, logistics companies usually build multiple depots to serve a great number of dispersed customers. Hence, multi-depot vehicle routing problems (MDVRP) win more and more engineers’ and companies’ attention to thrift their cost by using optimization methods. Considering NP-hardness of MDVRP and the lack of optimal solution derived by heuristic and meta-heuristic approaches in the large scale problems, in this...

A new approach to solve MDVRP in lower computation time

, Article 29th Iranian Conference on Electrical Engineering, ICEE 2021, 18 May 2021 through 20 May 2021 ; 2021 , Pages 632-636 ; 9781665433655 (ISBN) Rahimi Baghbadorani, R ; Zajkani, M. A ; Haeri, M ; Sharif University of Technology

Institute of Electrical and Electronics Engineers Inc 2021

Abstract

Vehicle routing problem is one of the complex and NP-hard problems, which plays a crucial role in this hectic world regarding people's lifestyle. Nowadays, many people provide their stuff online, so a logistic problem has been outstripped for companies to reduce their transportation costs. In this article, a novel approach has been introduced, which can solve the multi-depot vehicle routing problem in shorter time. By using clustering and decomposing the main problem into smaller ones, solution time has been dropped dramatically. In addition, this approach obtains a reasonable cost, which can be considered as fuel consumption, distance, or so forth. This method could reduce the solution time...

Analysis and data-based reconstruction of complex nonlinear dynamical systems : using the methods of stochastic processes

, Book Rahimi Tabar, M. Reza

Springer International Publishing 2019

Abstract

This book focuses on a central question in the field of complex systems: Given a fluctuating (in time or space), uni- or multi-variant sequentially measured set of experimental data (even noisy data), how should one analyse non-parametrically the data, assess underlying trends, uncover characteristics of the fluctuations (including diffusion and jump contributions), and construct a stochastic evolution equation?
Here, the term "non-parametrically" exemplifies that all the functions and parameters of the constructed stochastic evolution equation can be determined directly from the measured data.
The book provides an overview of methods that have been developed for the analysis of...

Tipping Cascades in Complex Networks: Dynamics and Control

, M.Sc. Thesis Sharif University of Technology Shahrabi, Ali (Author) ; Rahimi Tabar, Mohammad Reza (Supervisor)

Abstract

Tipping points occur in diverse systems in various disciplines such as ecology, climate science, economy, sociology, and engineering. Critical thresholds in system parameters or state variables at which a tiny perturbation can lead to a qualitative change in the system exist in many subsystems in complex systems. These thresholds are called tipping points, and these subsystems are called tipping elements. Additionally, many systems with tipping points can be modeled as networks of coupled multistable subsystems. Domino-like tippings are called tipping cascades. Considering that these tipping cascades are primarily unprecedented, it is essential to study the dynamics and control of these...

Improving Physical Layer Security for Cellular Users in Threat of Eavesdroppers

, M.Sc. Thesis Sharif University of Technology Rahimi, Mahdi (Author) ; Aref, Mohammad Reza (Supervisor)

Abstract

Security for wireless communication networks has become a crucial issue because of the broadcast nature of wireless channels. On every cellular network Since it is possible for passive nodes to easily overhear the confidential information transmitted between transmitter and receiver, it is necessary to provide secure communication.When a cellular user wants to communicate with a node or base station on the cellular network, it expects that information will be transmitted and received without interference, with enough quality and without eavesdropping. On the other hand In practical scenarios, we know that cellular network nodes are not equipped with ideal equipment and some percent...

Studying Synchronization Control in Complex Systems

, M.Sc. Thesis Sharif University of Technology Alimohammadi, Hamidreza (Author) ; Rahimi Tabar, Mohammad Reza (Supervisor)

Abstract

In this thesis, we review recent advances on controlling of complex systems. We provide in details, the concepts of synchronizability and synchronization controllability.Then we will investigate synchronization controllability under different pinning schemes, and propose a new pinning strategy to increase controllability and consequently decrease the number of required pinned nodes (known as driver nodes) to assure a stable synchronized state. We also study the network characteristics of resulted sequence of driver nodes. Finally, we will employ our proposed schemes to study the controllability of complex networks of chaotic Rossler oscillators

Study of Surface Growth of Organic Thin Film

, M.Sc. Thesis Sharif University of Technology Hosseini, Hadi (Author) ; Rahimi Tabar, Mohammad Reza (Supervisor)

Abstract

In recent decades the Due to development of coating techniques and the diversity of high organic matter, Discussion of organic coating materials being raised. Moreover, because of many applications of organic thin film in electronic and optical systems for example OTFTs and OLEDs Organic thin film growth topic is very interesting for scientists. Among these, some scientists study the theory and another bunch of scientists pay to practical aspects of this topic. In this thesis I pay to the theoretical level of Organic thin film growth and I simulate the system includes a collection of molecules, Went on to study some statistical properties of the system will be discussed and the dynamic...

Phase and Group Velocity of Scalar Waves in One Dimensional Disorderd Media

, M.Sc. Thesis Sharif University of Technology Rezanezhad, Vahid (Author) ; Rahimi Tabar, Mohammad Reza (Supervisor)

Abstract

In this thesis we study the dispersion of one-dimensional scalar waves in a random media. We used the finite difference method to obtain the numerical solution of wave equation in this media. Then we were able to find wave signals for different disorder intensities and at different distances from the source. Using the Wavelet Transform, intresting features such as phase and group velocity can be studied. The Morlet function is used as the mother wavelet for decomposing the signals at different places. Cross-correlation functions of Wavlet transforms of the signals at different positions are used to obtain phase velocity and its dependence on frequency. We show how the phase velocity at the...

Quantitative Analysis of Epileptic Seizure EEG

, M.Sc. Thesis Sharif University of Technology Hoseini, Mahmood (Author) ; Rahimi Tabar, Mohammad Reza (Supervisor)

Abstract

Since recording first electroencephalogram (EEG) of human brain in 1929 until now it becomes as a powerful tool in neuroscience. At first information extraction was done by visionary approaches only. But because of some problems in the context of inaccuracy and also in analyzing data different methods were proposed in order to extract hidden information of EEG. Among these approaches Fourier transformation was suggested as a very useful method that could draw out so many characteristics of signal different frequency components. However this way had many faults that cause limitation in analyzing time series and as a result other methods have been considered. One method that later has been...

Inferring the Directionality of Coupling forTwo Time Series

, M.Sc. Thesis Sharif University of Technology Ekhtiari, Nikoo (Author) ; Rahimi Tabar, Mohammad Reza (Supervisor)

Abstract

The synchronization phenomena are abundant is science, nature, engineering, and social life. Systems as diverse as clocks, singing crickets, cardiac pacemakers, firing neurons, and applauding audiences exhibit a tendency to operate in synchrony. These phenomena are universal and can be understood within a common framework based on modern nonlinear dynamics. First chapter of this thesis describes the basic ideas of the synchronization in an intuitive way. The main physical concepts are presented with experimental examples.
One of the main effects of synchronization is the ability to infer the directionality of coupling for two time series. Uncovering the directionality of coupling is a...

The Interaction Study of Thio-Organophosphate Pesticides with Colloidal Silver Nanoparticles for Colorimetric Sensing Applications

, M.Sc. Thesis Sharif University of Technology Rahimi, Sogol (Author) ; Hormozi-Nezhad, Mohammad Reza (Supervisor)

Abstract

Pesticides are broadly applied in croplands, glasshouses, and orchards in order to increase agricultural products and their quality. Among the variety of pesticides, organophosphorus pesticides (OPs), possessing high insecticidal activity, acute toxicity and relatively short environmental persistence, have been widely used for pest control in agriculture. However, this effect might lead to adverse health impacts or death for mammals and humans. Thus, even at trace levels, it is of great importance to develop a simple, sensitive, inexpensive and real-time detection method for monitoring the levels of pesticides in the environment, foodstuffs and biological samples. The integration of metallic...

Structural Disorders of Graphene and Its Effects on Electronic Properties

, M.Sc. Thesis Sharif University of Technology Abedpour, Nima (Author) ; Rahimi Tabar, Mohammad Reza (Supervisor)

Abstract

In this thesis we would like to investigate structural disorder of Graphene and its effect on electronic properties. Graphene is a one-layer crystal of Carbon atoms which was the first two dimensional crystal observed experimentally. Low energy current carriers on Graphene behave like mass-less Dirac fermions and this interesting electronic property attracts much attention on studying Graphene. Structural disorder of Graphene highly affects its electronic properties. We study thermal fluctuations of Graphene sheet, disorder super lattice, and static ripples, as structural disorders of Graphene. Disorders due to thermal fluctuations of graphene induce a disordered gauge field on the graphene...

Data-driven Control of Complex Systems

, M.Sc. Thesis Sharif University of Technology Parkavousi, Laya (Author) ; Rahimi Tabar, Mohammad Reza (Supervisor)

Abstract

In this thesis, we first briefly review the basic concepts of stochastic processes. After reviewing and studying the dynamic equation that can explain a stochastic process, we show how one can find on a data-driven basis, the first-, second- and higher-order interactions between different subunits of a complex system by disentangling the dynamics of multivariate time series into stochastic and deterministic parts. Our data-driven approach is to detect different degrees of interactions obtained using conditional moments of Kramers-Moyal coefficients from unconditioned correlation functions and statistical moments of multivariate N-dimensional multivariate time series. Finally, we study the...

Resilience Pattern in Neural Network

, M.Sc. Thesis Sharif University of Technology Mozafari, Tahereh (Author) ; Rahimi Tabar, Mohammad Reza (Supervisor)

Abstract

In this thesis the resilience of a neural network is examined under structural perturbation.The network consists of Spiking neurons with specific dynamics or they are binary neurons and the network is non-spiking. Neural network is a multi-dimensional and multi-stable system therefore we can map their dynamical equations to effective one-dimensional equation with one parameter which shows the environmental conditions.The resilience of the system is evaluated with respect to changes in weights and edges of the network and the the resilience pattern of the system is obtained.Finally, the recovery and control methods are briefly discussed

Reconstruction of Jump-diffusion Model from Epileptic Brain Signal and Pyramidal Neurons Potential in an Electric Fish

, M.Sc. Thesis Sharif University of Technology Shafaee, Yasaman (Author) ; Rahimi Tabar, Mohammad Reza (Supervisor)

Abstract

Complex systems involve a large number of degrees of freedom and consist of many components. Interactions of these components with each other, or with an external force, play a significant role in the collective behavior of the complex system.We come across complex systems in many different fields of study including neuroscience, climatology, studying stock markets, etc. The non-linearity of the interactions between their components is what they have in common. Interesting macro-scale properties can be observed in a complex system, as a result of the collective behavior of the system components. We usually focus on studying a group of components in a system, rather than a single component,...

Data Driven Study of Stochastic Processes with Non-Vanishing Higher-Order Kramers-Moyal Coefficients

, M.Sc. Thesis Sharif University of Technology Ⅿohebbi, Hassan (Author) ; Rahimi Tabar, Mohammad Reza (Supervisor)

Abstract

According to the Pawula theorem, we know that stochastic processes with non-vanishing higher-order Kramers-Moyal coefficients cannot be described by the Fokker-Planck and Langevin equation. Using rotating Gaussian white noise, we define generalized Brownian motion of different orders, also known as fractional Brownian motion. Similar to the Langevin equation, which is used for the random behavior of a stochastic process using standard Brownian motion, we also use a set of generalized Brownian motions for the random behavior of a stochastic process that has non-vanishing higher-order Kramers-Moyal coefficients of higher orders. Given that these noises are complex-valued, we define the...

Multidimensional Jump-diffusion Processes

, M.Sc. Thesis Sharif University of Technology Hamounian, Abolfazl (Author) ; Rahimi Tabar, Mohammad Reza (Supervisor)

Abstract

In this thesis, we first provide a brief overview of the basic concepts of stochastic processes and the mathematical tools required to study these processes. Then, we demonstrate that by using a data-driven approach, one can obtain the corresponding coefficients for deterministic, diffusion, and jump components of the stochastic process. In this method, the conditional moments of Kramers–Moyal coefficients are calculated using statistical moments of N-dimensional time series. These coefficients enable us to determine different orders of interactions, diffusion and jump properties, and %relationships coupling coefficients between time series. Furthermore, to evaluate the accuracy of the...

Configuration Design in Scalable Reconfigarable Manufacturing Systems (RMS)

, M.Sc. Thesis Sharif University of Technology Rezaie Baghbadorani, Parham (Author) ; Houshmand, Mahmoud (Supervisor)

Abstract

The dynamic nature of today’s manufacturing industry, which is caused by the intense global competition and constant technological advancements, requires systems that are easily adaptable with new functions and technologies. In fact, a highly responsive manufacturing system is needed in which, introducing new products, adjusting system capacity with demand fluctuations and integrating new technologies with the existing ones are quickly possible.Reconfigurable Manufacturing systems (RMS) are a relatively new paradigm in industry that enable rapid adjustments of production capacity to changes in product mix and volume through their main characteristics including modularity, scalability and...

Singularity time scale of the kardar-parisi-zhang equation in 2+1 dimensions

, Article Journal of Statistical Physics ; Volume 112, Issue 3-4 , 2003 , Pages 437-456 ; 00224715 (ISSN) Shahbazi, F ; Masoudi, A. A ; Reza Rahimi Tabar, M ; Sharif University of Technology

2003

Abstract

A master equation for the Kardar-Parisi-Zhang (KPZ) equation in 2+1 dimensions is developed. In the fully nonlinear regime we determine the finite time scale of the singularity formation in terms of the characteristics of forcing. The exact probability density function of the one point height field is obtained correspondingly

Using Deep Learning to Control of Complex Systems

, M.Sc. Thesis Sharif University of Technology Aminorroaya, Saba (Author) ; Rahimi Tabar, Mohammad Reza (Supervisor)

Abstract

A complex system consists of a large number of subsystems that interact with each other and with the environment. These systems have collective behaviors that may are desired and undesired. Learning, intelligence and epilepsy are examples of desirable and undesirable collective behaviors. Control of these systems arises when they are out of the desired state or one wants to avoid approaching the system to its undesired state. For control of complex systems, we need external functions that apply to specific subsystems. These functions can be obtained from the numerical solution of Hamilton-Jacobi-Bellman equation. The Hamilton-Jacobi-Bellman equation is nonlinear and must be solved at very...