Sharif Digital Repository

Since the start of Covid-19 pandemic lately in 2019 from Wuhan in China, a lot of countries encountered it. Healthcare sysytems are the most important system against pandemics so it is needed to measure the efficiency of healthcare systems against Covid-19 in order to find best practices. In this research, a 3-phased method is proposed to evaluate the performance of the healthcare systems. In the first phase, countries are clustered, in the second phase the DEA model is applied in 2 separate parts, in one part with considering clusters and in another without it. In the third phase resilience is introduced for Covid-19 and then it is used as a criterion beside two other criteria, DEA result... 

An infectious disease can spread through different communities via mobility networks. In this study we address three basic questions related to this matter in the meta-population approximation: firstly, where did the disease start? Secondly, when did the disease start? Thirdly, how does it spread in the network? To answer these questions, we introduce a generic mathematical framework with appropriate physical assumptions and study the spread of diseases. Then, with analytical solutions, we bring up different algorithms in order to answer these three questions. Using these algorithms, we redefine the effective distance and arriving time and unveil the simple geometry of the disease outbreak  

Since the first observed case in December 2019, millions of people have been infected by Coronavirus disease 2019 (COVID-¬19), which is caused by severe acute respiratory syndrome coronavirus 2 (SARS¬-CoV-¬2). Located on the viral membrane, trimeric spike glycoprotein is one of the most crucial parts of the virus’ structure as it is responsible for the attachment and entry of the virus to host cells. The spike glycoprotein undergoes hinge-like conformational movements and its receptor¬binding domains (RBD) can be in either an accessible (up) state or an inaccessible (down) state to the host cell receptors, such as ACE2. Having performed Molecular Dynamics Simulations and Targeted Molecular... 

In the world of today, the high rate of change, instability and uncertainty leave organizations under the constant effect of crises and unforeseen events. The prediction, prevention and control of crises alongside sustained performance and stability are now vital to the survival of organizations. The COVID-19 pandemic has created innumerable challenges for many businesses in Iran, including Small and Midsize Enterprises involved with health tourism, and has placed their subsistence at risk. The concept of Organizational mindfulness can help organizations avert crises and unexpected incidents, while rapidly bringing such events under control and mitigating the associated damage, should they... 

This study aims to develop a mathematical model for the equitable distribution of the drug or vaccine needed in a critical situation like the COVID-19 epidemic. This study has taken a unique look at the human dimension of social issues such as the cost of deprivation and equality. It seeks to ensure a fair vaccine distribution among priority groups and affected areas. Thus, it has developed a mixed-integer programming model to minimize distribution costs in the cold chain to reduce the social costs of the crisis while reducing logistical costs such as transportation, scarcity, and maintenance costs. To do this, we considered a three-tier chain consisting of a supplier, distributor, and... 

In this study, providing home care services by hospitals in the epidemic situations such as COVID-19 is proposed for the first time. Moreover, a mathematical formulation is developed to provide simultaneous decision-making about serving patients without COVID-19, scheduling nurses in the non-COVID-19 wards of hospitals, and scheduling and routing for nurses to serve patients at home. This problem aims to develop essential compatibilities to keep people safe and help continue vital healthcare services during the COVID-19 and similar pandemics. Accordingly, nurses' preferences, the number of available hospital beds, the patient-to-nurse ratio, the Unavailability of some nurses due to COVID-19,... 

This research is an event study about the effects of the Corona Virus Outbreak on different industries in the Iran Stock Exchange. This study examines which industries had been affected more negatively or positively by the COVID-19 pandemic outbreak. In the first step, we calculate Alphas, Betas, and expected returns of stocks in an estimation window before the event using the market model. Then, we group all stocks in 17 different industries and calculate average cumulative abnormal returns in the event period as good measures for examining defects of this outbreak. Our results show that transportation, chemical products, processed products, real estate, and automobile manufacturing were... 

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... 

In the last three years, the lives of many people around the world have changed with the spread of the Corona virus. In order to better manage the consequences related to the spread of this disease, extensive research has been done on this virus, and researchers in data science and artificial intelligence have devoted a part of their research to studying the effects of this virus on the people in one or different societies.On the other hand, the study of social networks about a specific issue or trend topic, allows us to examine more closely the atmosphere that governs the society and analyze the emotions, feelings and the level of concern of the members of the society about that issue.The... 

People's lives have been affected by the spread of the Covid-19 virus. Due to the high infectivity, governments have screened people, imposed curfews, mandated the use of masks, and so on to reduce the rate of transmission of the disease among people. Meanwhile, infected people are getting treatments: people who are slightly affected are quarantined at home, and those who are heavily affected are treated in hospitals. Hence there is an excessive increase in the hospital workload. On the one hand, this increased workload leads to physical fatigue and, on the other hand, to psychological problems, stress, etc. for the healthcare professionals. Therefore, it is very important to take care of... 

This research explores the impacts of the telework initiated by the outbreak of COVID-19, which is being called “emergent telework” in this research, on psychological well-being of teleworkers. As for the nature of emergent telework which is a new and unique phenomenon, a qualitative research is conducted. In order to do so, 15 in-depth interviews were held with employees from product teams of 11 organizations, and the interviews were analyzed using thematic analysis. General conditions of teleworking are identified in two categories named as “not working adjacent to coworkers” and “being away from the physical environment of the workplace”. Emergent telework, alongside the general... 

The research is performed to study the process of policy making and policy implementation of initiating student education network (Shaad) as as the first official platform of virtual education in Iran. We want to compare this process with “Kingdon’s multiple stream model”; because shaad initiated shortly after the closure of school’s caused by the outbreak of Covid-19 virus, while in recent years there have been several failed attempts to launch formal e-learning plans. Data were gathered trough semi-structured interviews of experts with shaad founders (11 people), reviewing some of the related documents and news, and unstructured observation by researcher. The findings were coded using... 

The epidemic of Covid 19 has killed millions of people worldwide. Despite the efforts of scientists around the world, there is still no cure for this disease. Approval of newly designed drugs due to clinical trial periods is time-consuming and costly. For this reason, in the current emergency situation, it is important to have a solution for screening available approved drugs in order to find effective substances for this disease.High-throughput assays are a good option for such problems. In this field of research, image-based high-throughput assays are amongst the most effective and cost-effective methods that help quantify the response of treated cells by measuring cell... 

The ongoing Covid-19 pandemic has driven our attention to a simulation of virus dispersion to complete our understanding of airborne transmission. A myriad of studies have shown that respiratory diseases such as MERS, SARS, and COVID-19 can be transmitted by virus-laden droplets released during coughs, sneezing, and normal breathing. To mitigate and prevent the spread of such infectious diseases, investigation of the transmission routes is of great importance. This study has been fueled to harness the CFD tool to simulate the virus-laden droplets dispersion in hospitals inwards. Because of the limitations intertwined with experimental works such as the risk of infection of experimenters, and... 

Organ-on-chip microfluidic devices create a three-dimensional and dynamic model that allows researchers to model diseases and test different drug candidates. In this regard, using a lung-on-a-chip microfluidic device, Covid-19 disease was numerically modeled. Initially, the distribution of oxygen concentration in the blood and respiratory membrane in the healthy state; when the respiratory membrane is the only barrier between air and blood; was found and observed that in this case, the length that the blood had to travel to reach full saturation was the same in the alveolar capillaries and the lung-on-a-chip microdevice. Then, to simulate the different phases of the disease, the formation of... 

Artemisinin as a natural peroxide possess a high anti parasite, and antivirus (Covid-19) properties which could be synthesized through the photooxygenation of dihydroartemisinic acid. This production possesses a lot of difficulties, for example, homogeneous catalyst is used for the photooxygenation reaction which makes photocatalyst and solvent non-reusable. In addition, separation of products from solvent and photocatalysts is difficult. Photooxygenation needs high pressure and low temperature which is very costly. Besides, because of several by-products which are producing during photooxygenation and protonation reactions, Artemisinin yield decreases. The aim of this study is to optimize... 

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... 

Cloud Manufacturing (CMfg) is a service-oriented manufacturing (SOM) paradigm that provides a dynamic, scalable, and virtualized working ecosystem. The CMfg collaborative structure can be modeled as a hyper-network-based service-demand matching architecture. It is enriched with quality of service (QoS) characteristics to produce customized products in a stable and reliable network. This stability should be considered in the overall manufacturing network mechanism. This Thesis has developed a multi-dimentional model and improved it by providing absorptive and adaptive strategies utilizing available resources and capacities to enhance the system’s stability and reliability against the... 

In the last few years, the most important problem to find a solution for the COVID-19 disease, and tests show that many factors are effective in the health and recovery of people with this disease. Therefore, scientists all over the world are looking to prevent the spread of this disease by identifying the effective factors in the recovery of corona patients and finding solutions for their health. The proposed algorithm is hybrid deep learning model CNN+GRU and appeal them to the laboratory test data from hospital. In this research, the goal is to be able to diagnose this disease in time with routine laboratory test, which consist of three main stages. In the first stage: initial... 

Vaccinating the global population against Covid-19 is one of the biggest supply chain management challenges humanity has ever faced. Rapid supply of Covid-19 vaccines is essential for successful global immunization, but its effectiveness depends on a transparent supply chain that can be monitored. In this research, we have proposed an approach based on blockchain technology, which is used to ensure seamless distribution of the Covid-19 vaccine with transparency, data integrity, and full traceability of the supply chain to reduce risk, ensure safety, and immutability. Without a proper mechanism to track and guarantee the authenticity of vaccines, all involved members, including governments,...