Sharif Digital Repository

Through the last decades, due to environmental issues and to confine CO2 emission and also dependency to the fossil fuels, renewable energy resources has been developed. It’s been expected up to 2035, the renewable energy resources will be scaled three times and among those resources, the wind energy will stand prominently. Out of this king of renewable resource, the horizontal wind turbine has been subjected in this research.The focus of is to design the controller in third of a 2 MW turbine operation by which stable rotor speed and nominal output power to be attained. Besides, to enhance the accuracy of the windturbine profiles, the TURBSIM software (At the National Renewable Energy... 

The development of the methods to evaluate the seismic resilience of communities, infrastructures, and structures has attracted many researches. To estimate the resilience with accuracy, developing a model that can simulate the events during the recovery time is very important. For the same, modelling the aftershocks with their accumulative effects on the damaged buildings during the recovery time has been the main focus of the current study. The proposed approach to simulate the aftershocks’ effect utilizes the Monte-Carlo sampling, in which each sample includes the two following steps. The first step is the simulation of the cumulative damage caused by the mainshock-aftershocks sequence... 

Wearable robots, or exoskeletons, are electromechanical devices that aim to assist user by supplying additional mechanical power as needed. The interaction of these robots with humans and the possibility of robots using their various abilities such as intelligence, control power, sensors, etc., make one of the crucial components of these control algorithms, its interaction and integration with the user. In this regard, functional electrical stimulation is one way to use human abilities to control the robot and achieve broader goals. Adding functional electrical stimulation to a wearable robot creates an emerging group of robots called hybrid exoskeletons. Hybrid exoskeletons provide the... 

Oil pollutants are among the important sources of pollution in countries with oil and gas industries such as Iran. Soil pollution by these pollutants is one of the environmental issues and hazards. All kinds of organic and inorganic pollutants in the soil may penetrate the underground water or enter the atmosphere in the form of gas, which respectively enters the food chain through absorption by plants or enter the body of living organisms through breathing. They include humans, which are a threat to the health and life of living beings. For example, many of these pollutions cause diseases such as cancer, suppression of the body's immune system, or even obesity; therefore, it is necessary to... 

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... 

Indoor positioning plays a pivotal role in a wide range of applications, from smart homes to industrial automation. In this thesis, we propose a comprehensive approach for accurate positioning in indoor environments through the integration of existing Wi-Fi and Bluetooth Low Energy (BLE) devices. The proposed algorithm involves acquiring the received signal strength indicator (RSSI) data from these devices and capturing the complex interactions between RSSI and positions. To enhance the accuracy of the collected data, we first use a Kalman filter for denoising RSSI values, then categorize them into distinct classes using the K-nearest neighbor (KNN) algorithm. Incorporating the filtered... 

The aim of this research is to examine and propose solutions for financing projects aimed at reducing vulnerability in the oil industry's infrastructure against earthquakes and enhancing their seismic resilience. Design and construction issues, as well as the gradual deterioration of oil infrastructure, increase their vulnerability to earthquakes. Earthquakes can disrupt the proper and continuous functioning of these infrastructures by causing damage. Such disruptions or interruptions in the performance of oil industry infrastructure can have significant economic and social consequences. To mitigate these damages, investment in vulnerability reduction measures is essential. Financing... 

As a result of technology advancement in composite materials and the growth of analytical tools, applications of these materials is increasing in various industries, especially in aerospace industry. One of the structures developed using these materials is hybrid structure with composite/elastomer layering. Stress analysis and study of free-edge effect in this type of structures is possible by using three-dimensional elasticity in composite layers as well as nonlinear hyperelasticity in elastomeric layers, and this is the topic that this thesis deals with. The proposed approach to solving the problem is that the composite/elastomer hybrid structure is first analyzed by the finite element... 

Asset management involves making decisions related to selecting the most cost-effective asset improvement strategies. There is an increasing interest of risk-based approaches in the field of asset management. During the asset life various risk factors might influence the asset performance and the maintenance cost, therefore, it is important to incorporate these risk factors, which affect the necessity and timing of various activities. This study develops a systemic risk-based asset management methodology (framework) to manage the maintenance of infrastructure assets. This paper presents an overview of uncertainty problems in cost estimating of bridge in the future and also discusses... 

The construction industry is faced with the problem of growing number of claims. If not settled, claims may lead to dispute among parties. Researchers have investigated claims from various perspectives. Nevertheless, more studies should be conducted in order to enhance the understanding about the root-causes of construction claims. The objective of this study is to utilize a systematic and well-structured methodology based on literature review, survey and interviews with experts in order to identify and classify the root-causes of claims of contractors as well as the situations that give rise to construction claims. Moreover, this study contributes to the claim terminology by distinguishing... 

The aim of this research is presentation of A framework to select the appropriate combination of retrofit and insurance in order to reduce earthquake losses. The vulnerability of buildings to earthquakes can lead to significant damage to owners and residents of these buildings. It is imperative that appropriate measures be taken to reduce these adverse effects before the risk occurs. Some of these measures, such as seismic retrofit of buildings, can reduce the vulnerability of buildings and, consequently, financial and human losses. Some other measures like insurance, in the event of an earthquake, can reduce the financial losses incurred by owners and residents of vulnerable buildings.... 

Sustainable energy is an important and necessary subject. A significant number of studies address the increasing energy production ratio per its cost. To this end, first of all we should increase the energy production. Second, damage and costs of production, set up and maintenance must be reduced. Control is one of the most important and effective tools in the way of achieving these purposes. The problem of controlling a wind turbine is generally divided into two sections of controlling the power chain and yaw control. In this research, both subjects have been investigated.Since there are some problems in measuring the wind speed, controlling the power chain requires prediction of the wind... 

Spin-Transfer Torque Magnetic RAM (STT-MRAM) is known as the most promising replacement for SRAM technology in cache memories. Despite its high-density, non-volatility, near-zero leakage power, and immunity to radiation-induced particle strikes as the major advantages, STT-MRAM-based cache memory suffers from high error rates mainly due to retention failure, read disturbance, and write failure. Despite its high-density, non-volatility, near-zero leakage power, and immunity to radiation as the major advantages, STT-MRAM suffers from high error rates. These errors, which are mainly retention failure, read disturbance, and write failure, are the major reliability challenge in STT-MRAM caches.... 

The representation concept links the information processed by the brain back to the world and enables us to understand what the brain does at a functional level.Representational models specify how activity patterns in the population of neurons relate to sensory stimuli, motor responses, or cognitive processes. In an experimental context, representational models can be defined as hypotheses about the distribution of activity profiles across experimental conditions. Three different methods are currently being used to test such hypotheses: encoding analysis, pattern component modeling (PCM), and representational similarity analysis (RSA). All three evaluate the second moment of the distribution... 

Despite intensive scientific investigations, drug addiction treatment outcomes have not significantly improved in more than 30 years. The addicted human brain can be conceptualized as a set of networks that spatially and temporally interact with each other in an abnormal way. Over the past several decades, neuroimaging techniques have contributed important novel insights into the neuroplastic alterations that result from drug dependence. Also functional connectivity magnetic resonance imaging (fcMRI) has emerged as a powerful tool for mapping large-scale networks in the human brain. On the other hand, transcranial direct current stimulation (tDCS) has been reintroduced as a noninvasive brain... 

Methamphetamine (meth) abuse and addiction (MA), with its serious medical, psychiatric and social complications, is a growing national disaster in Iran. Response control deficit during exposure to drug related cues is one of the main neurocognitive cores in MA and results in continued drug use and treatment failure. There have been many studies focused on cue exposure, but most of their paradigms required subjects to passively view the cues; this aspect of these paradigms cause a wide gap between reality and experimental studies. Developing a functional and structural neuroimaging protocol to map realistic brain circuits that are involved in craving among meth users is of importance.... 

Cogeneration technologies such as Combined Heat and Power (CHP) have promising features for providing the electrical energy that various industries require while reducing the emissions and other environmental impacts of these industries. Investments in CHP systems require substantial implementation costs followed by a relatively long period of recovering the invested capital through savings in utilities bills. Appropriate timing of CHP system investments can reduce capital expenses and enhance returns on investments. An appropriate investment valuation method is needed to identify the appropriate time to implement a given CHP system and to find the values of properly scheduled investments.... 

The present paper proposes a micromechanical damage model for two and three dimensional Representative Volume Element (RVE) with randomly distributed cohesive rough slit-like and penny-shaped micro cracks (Barenblatt-Dugdale type). First, the influence of crack roughness on the crack opening under macro hydrostatic stress state is studied and then the energy release contribution to material damage process is estimated. Considering the fractality of the crack trajectories yields to lower values of the volume crack opening. This will result in lower energy release rate in RVE and higher levels of material resistance. Based on the energy release rate of RVE, the effective material properties... 

In today’s competitive market, organizations need to modify their local perspective on enterprise, to a wider scope including supply chain. Focusing on supply chain, helps a more effective and efficient management for organizations. Today’s supply chain management is an inevitable part of enterprise management for achievement of integration between a supply chain’s partners. Oil and gas supply chain, as a complex supply chain, needs an effective and efficient management which uses from different tools and techniques, diagnoses the related errors and drawbacks among upstream partners. A management with such characteristics is scarce, and in this thesis it is tried to present an effective and...