Sharif Digital Repository

Fire behavior analysis and fire dynamics simulations, especially Wildfire, is of great importance due to all the necessities. The development and application of fire dynamics models, especially in complex geometric spaces, has become one of the priorities of the firefighting and environmental organizations of countries and international unions at the international level today. Analytical methods are not suitable for complex geometries due to the complexity of fire dynamics equations. Experimental methods are a desirable method for investigating complex geometries, but the fire phenomenon requires a high experimental study cost; Because fire causes severe damage or even destruction of a... 

This research focuses on examining and improving healthcare systems, particularly during crises and pandemics. Following disasters such as natural calamities and pandemics like COVID-19, healthcare systems face significant challenges due to the increased demand for medical services, creating a substantial threat to the population in the affected regions. This study emphasizes the importance of utilizing modern technologies such as the Internet of Things (IoT) and telemedicine systems in alleviating the pressure on healthcare systems. A combined approach of prediction and multi-objective optimization based on simulation is proposed in this study to improve resource allocation and demand... 

Increase in growing concerns over environmental pollution and depletion of fossil fuel resources motivate the need for cleaner energy technologies and stimulate research in facilitating renewable energy systems. In recent years, photovoltaic systems have attracted great attention since they remove the need for energy storage systems and intermediate processess for energy conversion. However, high capital cost, low efficiency and low energy density per area of these systems, as compared with other technologies hinder its industrial use. To surmount these bottlenecks and improve technical performance of PV systems, it is crucial to optimize configuration of convertor connection and to improve... 

In recent years, the use of fiber reinforced polymer (FRP) jackets, as an external lateral confinement has found considerable attention in retrofitting and strengthening existing reinforced concrete (RC) columns in earthquake prone areas. The FRP composites have numerous advantages such as ease in application, high strength and stiffness-weight ratio, no corrosion and negligible changes in the member dimension. Most of previous studies have concentrated on evaluation of the effect of confinement with spiral bars or FRP composites, separately. However, in practice both types of confinements exist in strengthening RC columns.
This paper presents the results of a computational modeling to... 

Different data sources are creating a huge amount of data at increasing speeds that require real-time processing. Such data is called “Big data stream". Although, mining and analysis this type of data is so useful for companies, but it also may cause many privacy breaches. The principle issues for big data stream’ anonymization are real time processing and information loss. There are some works that are proposed for data streams, but they have some drawbacks such as inefficient anonymization of big data stream and also not consider time expiration of tuples that lead to increase the information loss and cost of the data publishing. In this thesis, in order to speed up the ability of big data... 

Multi-Criteria Decision-Making models have been considered by many researchers in recent years. In this study, considering the transition matrix, the probability of changing in the priories of the customers in the framework of a hybrid QFD-ANP has been proposed. The developed methodology is implemented to solve the supplier selection problem, one of the most important problems in the supply chain management, in a dairy manufacturer in Iran. The company is one of the most prominent companies that has a big segment of the dairy market. The results show the efficiency of the proposed methodology for multi-criteria decision-making problems.• Chapter 1) General research reasons for the purpose... 

One of the main challenges in the design of wireless sensor networks (WSNs) is minimizing the energy consumption while simultaneously maximizing the performance of sensors. In this thesis, we have considered WSNs based on beacon enabled IEEE 802.15.4/Zigbee Standards with low rate applications like temperature, humidity and light sensing, which mainly have been used in a smart home environment, and proposed a cross-layer design to overcome this challenge. The design involves an optimizer module that captures the application layer and MAC sub layer behaviors. Based on these behaviors, the optimizer dynamically changes the rate of node’s traffic at the application layer and the priority of... 

We present a home energy management system that is able to manage home energy demand and resources to achieve minimum household payment in electricity dynamic pricing.Communication is used to collect needed data from the home energy system members and users in order toimprove demand and resources management. Some of the needed data comes from appliances and solar panels by wireless sensor network and some other is received from home users by a user interface.
Two algorithms are proposed that the first algorithm goal is to minimizing household payment and the second algorithm goals are flexible implementiation and decreasing household payment. To decrease household payment, these... 

Today, smart devices have become an integral part of everyday life. The Android operating system is also the most popular operating system of these devices, and as a result, various malwares are produced and distributed for this operating system every day. This makes it especially important to investigate these malwares. This includes finding people involved in the development and distribution of malware, as well as discovering other malwares created by them. Discovering other involved entities, such as social media accounts, websites, Android store accounts, and taking steps to prevent malware from being distributed by them is another aspect of this story. In order to deal with organized... 

Particulate matter is an important source of air pollution. Particulate matters have an Undesirable effect on the environment, economic, and the health of Tehran Citizens. Annually, more than 8 thousands of tons of mineral dust from Internal and external resources deposit in Tehran city. In this project, the increase in the level of PM10 concentration during June, 12th to 14th, 2015 have been considered. The intrusion and dispersion of mineral dust during June, 11th to 15h, 2015 have been simulated with the HYSPLIT Model. Also, the Trajectory of particle end in Tehran during the mentioned days simulated and plotted with the HYSPLIT. The results show that more than 85% of PM10 reported by Air... 

In this thesis a novel Fuzzy Fractional Order Controller (FFOPID) is presented. This controller is designed by the means of the combination of a fuzzy system and a fractional order PID. Fractional controllers, especially fractional PIDs, shows their performance in control systems after the advent of fractional calculus. Fractional PID has better flexibility according to the classic PID. As the real control systems are nonlinear actually, so solving the control problem needs a nonlinear controller. Therefore, a fuzzy system is used in this thesis, in order to adapt the controller parameters with different operating points of the system. Fuzzy system design needs the optimal values for... 

Quality and intelligibility are two aspects of speech that are affected by various factors, such as background noise and echo. The performance of many commercial and military speech-based systems depends on at least one of these aspects of speech. Therefore, this research aims to design an improvement model to remove background noise and reverberation from the speech signal. The model training framework is based on deep learning methods and has a supervised approach in the time domain. The input of this system is the raw waveform of the speech signal mixed with noise and reverberation, and the output is the enhanced waveform of this signal. An architecture is proposed in this thesis based on... 

Reconfigurable Manufacturing system (RMS) is used to surge the speed of production and its flexibility of it which is restricted to limited extent. Its flexibility confined to at most that is essential to fabricate the members of a part family. This thesis proposes a novel model for RMS, that, that is a manufacturing framework that is cost-effectively and at the minimum time responses to changesto changes and can fulfill thefulfill marketthe demandmarket demands rapidly. In many researches the minimization of timeof time and cost is the main factors that is making anmake impressionan onimpression projecton the performance of the performanceproject. In the frame offrame theof...