Sharif Digital Repository

large-scale data collection from multiple sources to a single entity, such as a cloud provider, poses a challenging problem for implementing centralized machine learning algorithms. Constraints such as privacy protection and restrictive access policies that prevent accessing personally identifiable information hinder the development of centralized machine learning algorithms in important and sensitive domains like healthcare. However, from early disease detection to discovering new drugs, leveraging artificial intelligence in this domain is a fun-damental necessity. As a potential solution, federated learning has been proposed, allowing data owners (users) to jointly train a shared machine... 

Nowadays, multilevel converters are significantly developed in industrial applications as well as energy transmission systems regarding proper quality of output waveforms and fault tolerant operation ability. Among the different topologies of multilevel converters, modular multilevel converter (MMC) due to its modularity feature it more accepted in high voltage direct current (HVDC) transmission systems. Fast fault detection in power electronics converters is necessary to bypass the defected part in order to prevent failure propagation to other Submodules and to provide continues servicing. On this basis, different researches are reported in literature for MMCs fault tolerant operation. In... 

The goal of this study is to investigate the effect of events such as earthquakes on businesses. Earthquakes can have a significant impact on the performance and profitability of businesses. Earthquakes can negatively affect the functionality of community infrastructure systems by damaging their components and this disruption in the functionality of the lifelines of the community can negatively affect the businesses that are dependent on their functionality. In addition, earthquakes will cause casualties and injuries, leading to a decrease in the workforce and the customers’ population. In such a situation, the activity of many businesses is disrupted and even stopped, which in turn has many... 

The purpose of this study is to present a suitable model for calculating the costs imposed on society due to deaths and injuries due to infrastructure failure due to earthquakes, which is used in the analysis of community resilience. Much research has been done to date to calculate the economic costs of infrastructure failure. However, no suitable analytical framework has been provided to quantify the costs of deaths and injuries to people due to earthquake failure. Previous research has provided methods such as the value of statistical life to quantify the social costs caused by accidents and environmental pollution. However, the literature review results in the field of seismic resilience... 

In earthquake-prone communities, the post-earthquake functionality of hospitals is crucial. Hospitals can dramatically reduce earthquake casualties if they can remain functional and retain service continuity. A variety of earthquake-induced problems such as damage to hospital components, unavailability of medical staff, disruption in medicine supply, and failure of supporting infrastructure systems can negatively affect the functionality of a hospital. Hospital administrators and facility managers require appropriate tools to assess the effect of these problems on hospital functionality. This research presents a probabilistic framework to assess the functionality of hospitals following... 

The increasing dependence of urban communities on infrastructure highlights the importance of resilience in the event of natural disasters, including earthquakes. Every society is made up of various infrastructures such as water supply, electricity, transportation, hospitals and so on.Every infrastructure to serve the community depends directly or indirectly on the electricity infrastructure.The power supply infrastructure consists of three main systems of electricity generation, transmission and distribution. Power substations, as nodes of the transmission and distribution network, are considered to be very vital nodes that it is important to maintain their serviceability after severe... 

Natural disasters can damage the infrastructure of society. Damages to the infrastructure components of society can disrupt their service delivery. Disruption in providing services to society's infrastructure can disrupt social and economic activities and impose various significant costs on society. The cost of repairing the damaged infrastructure and reducing the income of households are among the economic damages of accidents. The decline in the quality of life, as well as the death and injury of people due to the breakdown of the infrastructure or the disruption in their services, are among the social damages caused by accidents. In the same way, natural disasters are considered a... 

This study proposes a probabilistic framework to quantify the seismic resilience of urban natural gas distribution networks. Infrastructure resilience is defined as the ability to maintain performance after a hazard or, in case of a loss of performance, return to the minimum desired level in the optimal time. The framework presented in this research is comprised of multiple interconnected probabilistic models. These models work in harmony to characterize the impact of the earthquake on various infrastructures such as the buildings and urban gas distribution network components, as well as the probable consequences of the earthquake. The post-earthquake recovery of the gas distribution network... 

This study proposes a probabilistic framework to quantitatively evaluate the resilience of a community comprising a building stock, commercial facilities, and interdependent infrastructure systems. To this end, the proposed framework employs Monte Carlo sampling in which each sample comprises multiple stages. The sample starts with the occurrence of a hazard event. It then follows by evaluating the consequences incurred by the community in the face of the hazard event. It is concluded by simulating the operations aimed at complete recovery of the community comprising inspection, rescue and relief, restoration, and recovery. For this purpose, chains of interacting probabilistic models are... 

Despite the vulnerability of non-structural systems in buildings to disasters, their resilient design has received minimal attention from the practitioners of the construction industry. However, interruption in the performance of these systems jeopardizes the functionality of the buildings and threatens the resilience of the whole community. To address this issue, the present study proposes a novel framework for predicting possible damage states of non-structural building systems under disasters. The proposed framework benefits from an automated combination of Building Information Modeling (BIM) as a visualized 3D database of the building's components and the Machine Learning (ML)... 

Predicting the trend of stock prices is always one of the concerns that stock market analysts and investors face with, which plays a critical role in maximizing the profit from investing in stocks. Past stock price charts, raw material prices, the value of the company's assets, the impact of global markets, the company's products, the organization's development plans, and the same other factors influencing the stock price. News reports are an important source of information for people. Recently, a lot of research has been done to examine the impact of news on stock price trends. This research has two research phases. In the first phase, a text mining method is presented which is using... 

Increased globalization and level of complexity of supply chains have made them more vulnerable to environmental disruptions than ever before. However, conventional methods of risk management can not help supply chains in the face of turmoil and disruption, because of unexpected and unfortunate events due to the unpredictability and uncertainty in which they are. They can have irreversible effects on supply chains and even threaten the very existence of members of these chains. In such a situation, the key to the success and survival of supply chain operations is to achieve supply chain resilience. On the other hand, health care supply chains are one of the most important and vital parts of... 

The series structure of semiconductor devices has a wide application in the industry and research field. The most critical issue in the series structure of series switches is the safe operating condition provision. Hence many kinds of research have been intensively focused on this topic to overcome this necessity. However, many existing aspects relevant to the series stacking of the semiconductor switches have not been pointed out. These include, the power loss must be accepted for the series devices and recovery of this power, providing balanced voltage for the series devices through a simple and easy implementing structure and providing a safe voltage condition for the series devices under... 

Nowadays, wireless communications for multimedia purposes is widely spreaded especially due to video communication demands. One of important considerations in this area is to receive video stream with less effect of errors related to transition channel as well as optimal utilization of bandwidth. The H.264 is exploited as the most efficient video compression standard and because of its predictive nature of encoder and decoder, it is very sensitive to error propagation, so error resilient technics should be applied along with the video compression to reduce the visual impacts of error occurrence and propagation. In this thesis existing methods of video error resilience, video quality measures... 

The purpose of study is the modeling and evaluation of the role of authorities in enhancing the effectiveness of seismic vulnerability reduction policies. Seismic vulnerability reduction of infrastructures depends on the measures that must be taken before a disaster occurrence. In addition to increasing disaster preparedness, an important part of the pre-disaster measures is taken to increase the robustness of the infrastructure. In some cases, measures to reduce the vulnerability of infrastructure, such as the resilience of residential buildings, require the coordinated role’s implementation of relevant organizations. Evidence shows that in many cases, policies to reduce the vulnerability... 

This thesis proposes a probabilistic modeling framework for networked infrastructure systems in community resilience analysis. In particular, the framework is presented for the electric power infrastructure. Models are proposed at two levels of refinement. The basic model only determines the connectivity of different elements in the network, whereas the refined model also quantifies the amount of the power transmitted through the network elements. In a community resilience analysis, the proposed basic model provides a rather simple tool to determine those buildings and infrastructure systems that suffer from power outage when the supplying power station loses connectivity with the network.... 

Integrated silicon photonic networks have attracted a lot of attention in the recent decade due to their potential for low-power and high-bandwidth communications. However, despite high bandwidth and low-loss data communication capability, optical NoCs are susceptible to on-chip temperature variations. In these promising networks, packets’ erroneous routing due to thermally-induced resonant wavelength shift of microring resonators are common temporary faults unless heat control mechanism is adopted. In other words, thermal drifts may paralyze wavelength-based operation of these networks. On the other hand, employing a heat control mechanism in an ONoC necessitates developing thermal fault... 

This study provides a probabilistic framework for assessing and quantifying flood damage to infrastructure. This framework models the state of the community's infrastructure after the occurrence of possible floods in five steps. The first step is to model the hazard using a set of models that determine the characteristics of potential floods. The second step is to model and estimate the damage to community buildings and infrastructure. In the third step, infrastructure serviceability is modeled. The infrastructures that are modeled in this study are water distribution network, power network, transportation networks and industrial facilities for processing agricultural products. In the fourth... 

The aim of this study is to quantify the social impacts of infrastructure failure for community resilience after seismic hazards with the focus on Post Traumatic Stress Disorder (PTSD). Many studies have investigated the failure of infrastructures and their interdependencies for community resilience; however, there is a lack of comprehensive quantitative resilience framework considering social interactions along with lifelines. The upcoming research is based on the Rtx framework, which was developed at Sharif University of Technology for community resilience analysis. In the mentioned framework, the performance of different community infrastructures is simulated using probabilistic and...