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    Persistence in Seasonally Forced Epidemiological Models and Seasonally Varying Predator-Prey Models Via the Basic Reproduction Number

    , M.Sc. Thesis Sharif University of Technology Hashemian, Zahra (Author) ; Hesaraki, Mahmoud (Supervisor)
    Abstract
    In this study, we will examine persistence of various kinds of seasonally forced epidemiological models and seasonally varying predator-prey models. The results of our study regarding persistence of the models will be shown via basic reproduction number. We will show that, in the framework of our study and under some conditions, persistence is obtained as long as the basic reproduction number is bigger than one. We will also prove that, in the framework of our study and under sufficient conditions, if the basic reproduction number is smaller than one, the species under discussion won’t survive in the predator-prey models, and the disease(s) would go extinct in the epidemiological... 

    Failure Tolerance of Epidemic Spreading in Complex Network

    , M.Sc. Thesis Sharif University of Technology Mirzasoleiman, Baharan (Author) ; Jalili, Mahdi (Supervisor)
    Abstract
    Complex networks serve as generic models for many social, technological and biological systems that have been shown to share a number of common structural properties such as power-law degree distribution and small-worldness. These networks determine interactions and influence the spread of diseases, behaviours and ideas. Epidemics and failures like new behaviours ideas and innovations can spread throughout a network and prevent it from doing its functionalities. In this work, we investigate error and attack tolerance of epidemic spreading in complex networks. The main content of this thesis is arranged in three sections as follows: Firstly, the effect of random and systematic failures is... 

    Covid-19 & Income Mobility in Iran

    , M.Sc. Thesis Sharif University of Technology Mehri Khonakdari, Reza (Author) ; Keshavarz Haddad, Gholamreza (Supervisor)
    Abstract
    During the covid-19 pandemic, in many countries, women's employment sector received more impact than men's. Some researchers consider this incident due to a decrease in the supply of women due to the closure of childcare centers and absenteeism in schools. Some consider this to be due to a reduction in the demand for women's labor due to the damage to the service sector. In this research, using the transition matrix, we showed that, during the epidemic period, the households in which women were employed in the pre-epidemic period (first group) had a greater reduction in income mobility than the households in which only men were employed (second group). Then, using the ordered logit of... 

    Critical-Item Supply-Chain Using Agent-Based Modelling

    , M.Sc. Thesis Sharif University of Technology Malaek, Mohammad Matin (Author) ; Haji, Alireza (Supervisor)
    Abstract
    One of the crucial matters in the area of Supply Chain Management is the ability of a supply chain to act and react under different circumstances. A helpful tool to understand the supply chain is simulation modeling. With the help of simulation modeling, we can provide the opportunity for the agents in a model to perform based on the defined environment.In the current research, a complete literature review is performed on the topics of supply chain planning and various distribution models and algorithms. With the focus on the vaccine as a critical item, we propose a model to distribute vaccines based on the degree of agents, and we realize that vaccine distribution, while facing huge demand... 

    An Approach to Optimize Resource Allocation and Strategies to Control Infectious Diseases

    , M.Sc. Thesis Sharif University of Technology Mohammadi, Ahmad (Author) ; Najafi, Mehdi (Supervisor)
    Abstract
    Infectious diseases have always been a threat to mankind, and is the greatest causes of death of children and young people. Although this type of diseases is a serious threat to public health; the allocated resources in responding to a semi-large pandemic is inadequate. Therefore, it is important to spend the resources in the most effective and efficient ways to improve pandemic response capability. That is why considerable research be devoted to study different aspects of epidemics, and developed mathematical approaches to choose appropriate strategies in pandemic response. Since the epidemic models are simplified means to describe the transmission of disease, researchers often use these... 

    Scheduling and Allocation of Pandemic Vaccine Distribution Among Healthcare Centers and High-risk Groups

    , M.Sc. Thesis Sharif University of Technology Fathi, Mohammad Reza (Author) ; Eshghi, Kourosh (Supervisor)
    Abstract
    This study offers a framework to manage mass vaccination programs in response to an outbreak in a city. Compared to previous studies, we consider more operational challenges in the vaccination process; for example, transshipment between vaccinations units and availability of second doses. Our objective function is based on the risk of unvaccinated individuals. Therefore, the model aims at favoring those places in the city where the risk of unvaccinated people is high. Using different kinds of vaccines is another factor that our mathematical model includes. Vaccines are categorized into single-dose and double-dose classes. In this regard, the balanced access to different vaccine types is of... 

    A Systems Dynamics Approach to Simulate Epidemic Spread of Covid-19

    , M.Sc. Thesis Sharif University of Technology Sepehri, Sepehr (Author) ; Roosta Azad, Reza (Supervisor)
    Abstract
    The outbreak of a type of corona virus in 2019, plunged the world into a huge panic. Businesses entered into an unprecedented recession and economic growth was severely reduced. Millions of people have been infected and unfortunately countless numbers have also lost their lives. This which quickly crossed the borders of countries, proved how much a not-so-deadly infectious disease can affect human life. Another point that was revealed was the importance of epidemiology knowledge. Since the beginning of the outbreak of this disease, scientists in this field have tried to predict the state of the disease in the coming days by presenting models. Many countries formed special working groups to... 

    Solving Delayed SIRS Meanfield Model on Homogeneous Networks

    , M.Sc. Thesis Sharif University of Technology Saeedghalati, Mohammad Karim (Author) ; Ejtehadi, Mohammad Reza (Supervisor)
    Abstract
    In this work we simulate SIRS1 model on homogeneous networks by means of simulation, then we drove meanfield equations for this model and compared the solution of these equations to the simulations results on the network. To obtain a new model closer to the reality, we modified the SIRS model and introduce history to the convenient model. After simulation of this model we redrove the equations with history and found that this model can show bifurcation so we found the phase diagram for this model. And in the last part we introduced history to a meanfield model with pair approximation and drove the equations and try to solve
    them numerically.
     

    Effects of Temporal Correlations on Co-infection

    , M.Sc. Thesis Sharif University of Technology Sajjadi, Ebrahim (Author) ; Ejtehadi, Mohammad Reza (Supervisor) ; Ghanbarnejad, Fakhteh (Co-Supervisor)
    Abstract
    SIS and SIR are common models for describing and predicting the epidemics of the contagious diseases. But these models fail to predict patterns of spreading dynamics in the case of co-infective diseases, i.e. getting infected by one disease, alters the chance of getting infected by the other one. Coinfection has been studied in the mean field approximation and on complex networks with different topologies. Another study shows temporal correlations of the underlying transmission network, play role on co-infection dynamics.In this research we investigate the effects of various temporal correlation on epidemic order parameters of independent infection and co-infection.For this purpose, we... 

    A New Immunization Algorithm Based on Spectral Properties for Complex Networks

    , M.Sc. Thesis Sharif University of Technology Zahedi, Ramin (Author) ; Khansari, Mohammd (Supervisor)
    Abstract
    Vaccination is one of the ways of disease control and prevention, which not only protect individuals against the disease, but also reduce the disease spread rate. Mass vaccination of individuals is not always possible due to the high cost and limitation of immunization resources. Therefore, researchers are always seeking solutions to find the persons that their immunization may have a greater impact in reduction of disease spread rate. The advent of network epidemic models and the possibility of removal the secured nodes in those models, showed that this problem is equivalent to finding a limited set of individuals that their removal will eliminate or minimize the number of people at risk of... 

    Exact Solution of Generalized Cooperative SIR Dynamics

    , M.Sc. Thesis Sharif University of Technology Zarei, Fatemeh (Author) ; Moghimi Araghi, Saman (Supervisor) ; Ghanbarnejad, Fakhteh (Co-Supervisor)
    Abstract
    Epidemics are one of the most important issues in social environments, economics systems, medicine, and other environments. In the study of the epidemics, some behaviors have been observed that are very similar to the phase transition in critical systems. For example, by changing the parameters that the epidemics process is characterized, the system’s epidemic behavior changes. Depending on the type of problem, this behavior change may be similar to continuous or discontinuous phase transitions. One of the fascinating issues that have just been taken into consideration in this area is the cooperation of two or more diseases. This means that the rate of transmission of a disease depends on... 

    Optimal Two-Phase Vaccine Allocation under Uncertain Impacts and Different Transition Rates

    , M.Sc. Thesis Sharif University of Technology Dodangeh, Sana (Author) ; Najafi, Mehdi (Supervisor) ; Rafiee, Majid (Supervisor)
    Abstract
    Infectious diseases have always threatened the health of human beings. One of the most important causes of mortality in human societies is infectious diseases. The spread of these diseases in society, even if does not lead to death, can have devastating effects on society. Influenza is one of the infectious diseases that has attracted much attention today. It can be mild or severe and even cause hospitalization and death. Therefore, controlling and preventing the epidemic of this disease is very important. Epidemic models are commonly used to simulate the spread of infectious diseases. In this study to identify the influenza outbreak, a stochastic multigroup SEIR model with the migration... 

    Inference for Network Parameters in Stochastic Epidemic Models

    , M.Sc. Thesis Sharif University of Technology Dehbod, Siamak (Author) ; Ejtehadi, Mohammad Reza (Supervisor)
    Abstract
    Different models describing the procedure of epidemics are complicated and involving numerous factors. Some of these models that used a stochastic network for modelling epidemics had been successful in statistical prediction of spreading epidemics. However, in many cases there is no direct way to determine parameters of these models. In this thesis it has been desired to estimate those parameters based on historical data of epidemics To estimate structural parameters, concerning epidemic network, two independent inference have been studied. In the first inference, the probability of disease transmission from one person to another is estimated.
    In the second, using Bayesian inference,... 

    A Multilayer Approach to Network Immunization Based on Digital Information

    , M.Sc. Thesis Sharif University of Technology Joneydi, Sara (Author) ; Khansari, Mohammad (Supervisor)
    Abstract
    Researching in the field of optimization of network immunizing and epidemic spreading is an active and important area. According to literature review, influential nodes are detected based on global graph metrics such as centrality measures. On the other hand, when a network infrastructure is not available and a direct or straight path between source and destination may not be accessible, one can use opportunistic networks routing protocols in Delay Tolerant Networks to recognize influential users is an appropriate approach. In this work, we use a real world three layer dataset which consists of digital data (social relations and Bluetooth contact traces) of individuals. We convert the real... 

    Study of Antibacterial Performance of Metal Oxide Nanostructures and their Effect on Bacterial Growth Kinetics

    , M.Sc. Thesis Sharif University of Technology Afkhami, Fatemeh Sadat (Author) ; Naseri, Naimeh (Supervisor) ; Zaker Moshfegh, Alireza (Co-Supervisor)
    Abstract
    Fighting contagious microbial diseases is considered a serious health issue, which has attracted much attention in worldwide. Thus, development of new materials based on nanostructures as a new generation of antibiotics to address this challenge has been of interest to researchers in recent years. Nanostructures based on metallic oxide semiconductors such as oxides with light absorption, production of electron-hole pairs in needle like structures cause tearing bacterial membrane and eventually destroy the bacterium. To this end, we designed experiments to study mechanism and physics governing the process of bacterial degradation to determine the best conditions for inhibiting bacteria... 

    Epidemiology and Networks

    , M.Sc. Thesis Sharif University of Technology Ashrafi Amineh, Rasa (Author) ; Haji Sadeghi, Mir Omid (Supervisor) ; Razvan, Mahammad Reza (Supervisor)
    Abstract
    Networks and the epidemiology of directly transmitted infectious diseases are fun-damentally linked. The foundations of epidemiology and early epidemiological models were based on population wide random-mixing, but in practice each individual has a finite set of contacts to whom they can pass infection; the ensemble of all such contacts forms a network. Knowledge of the structure of the network allows models to compute the epidemic dynamics at the population scale from the individual-level behaviour of infections.Motivated by the analysis of social networks, we study a model of random net-works that has both a given degree distribution and a tunable clustering coefficient.We consider two... 

    Fair Multi-Dose Multi-Vaccine Distribution with Uncertain Demand

    , M.Sc. Thesis Sharif University of Technology Asad Araghi, Alireza (Author) ; Haji, Alireza (Supervisor) ; Fatahi Valilai, Omid (Supervisor)
    Abstract
    Among disasters, outbreaks of pandemics account for excessive human and material damages,including a significant number of deaths. During any pandemic and once an or a set of effective vaccines have been identified/produced, governments all around the world enter a crucial phase when a crucial demand for an effective global vaccination campaign arises to vaccinate the population to stop/avoid the disease, knowing that the vaccines are not immediately available and may even become available with considerable delays (i.e., delivery and validation delays). Therefore, such phase of a pandemic is very crucial to identify and produce effective vaccines as well as to globally and equitably... 

    Identifying the Effect of Gasoline Consumption on Pollutant Emissions with the help of The Covid-19 Outbreak Exogenous Shock

    , M.Sc. Thesis Sharif University of Technology Abouzarpoor, Hassan (Author) ; Rahmati, Mohammad Hossein (Supervisor)
    Abstract
    Gasoline consumption resulting from vehicular traffic is one of the most significant factors influencing the emission levels of pollutants. Since the sold gasoline at fuel stations does not necessarily translate into vehicular traffic, tracing the final consumer becomes challenging. hence, estimating the impact of gasoline consumption on air pollution is accompanied by biased results. Moreover, the COVID-19 outbreak, acting as an exogenous shock, has provided an opportunity to use data such as COVID-19 and intercity travel as instrumental variables, gasoline consumption, and emission levels, between 2018 and 2020, show unbiased estimates of the effect of gasoline consumption on air... 

    Preventing The Spread of Disease in Social Networks

    , M.Sc. Thesis Sharif University of Technology Abnousi, Armen (Author) ; Jafari, Amir (Supervisor)
    Abstract
    In this thesis, first we will have a thorough review on problems and models presented in the field of contagion in networks (spread of diseases, spread of computer viruses,etc.). Then we will investigate the basic model of virus inoculation game with purely selfish players and the modified version of it which takes into account a factor of friendship. We will discuss the results of these models including computing and comparing Nash Equilibria  

    Exact solution of generalized cooperative susceptible-infected-removed (SIR) dynamics

    , Article Physical Review E ; Volume 100, Issue 1 , 2019 ; 24700045 (ISSN) Zarei, F ; Moghimi Araghi, S ; Ghanbarnejad, F ; Sharif University of Technology
    American Physical Society  2019
    Abstract
    In this paper, we introduce a general framework for coinfection as cooperative susceptible-infected-removed (SIR) dynamics. We first solve the SIR model analytically for two symmetric cooperative contagions [L. Chen, Europhys. Lett. 104, 50001 (2013)10.1209/0295-5075/104/50001] and then generalize and solve the model exactly in the symmetric scenarios for three and more cooperative contagions. We calculate the transition points and order parameters, i.e., the total number of infected hosts. We show that the behavior of the system does not change qualitatively with the inclusion of more diseases. We also show analytically that there is a saddle-node-like bifurcation for two cooperative SIR...