Sharif Digital Repository

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... 

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... 

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... 

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... 

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... 

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... 

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...