Sharif Digital Repository

For increasing longevity of a structure, it is not enough to notice only to designing aspects. In operation phase of a construction, we can increase the level of service and longevity. Asset-based Organizations, in addition to design their new assets, should maintain them. Infrastructures, such as road, bridge, dam, and water network, are important because of social and economic aspects. So they need special attention. There are efficient models for infrastructure maintenance that consider infrastructure element information, such as condition rate, weight, dimensions, deterioration rate, and cost of maintenance as inputs and give planning for maintenance in future. This planning, involves a... 

The problem of spacecraft attitude determination (AD) using thermal data is investigated. Given the Solar space environment, the key dominant mechanism of heat transfer will be radiation, in which the Sun and Earth are the major contributing heat sources that affect the satellite external surface temperatures. In this sense, the net heat fluxes (NHF) of a satellite surface that is insulated against any internal heat communication will only be related to these main radiating sources. In order to utilize the satellite temperature data for AD, a heat attitude model (HAM) that relates the satellite surfaces NHF to its attitude is developed using three orthogonal satellite surfaces. Assuming... 

The purpose of Direction-of-arrival(DOA) estimation in MIMO communication networks is to find the direction of signals that are mixed together and mixed with noise by using an array of multiple receiving antennas. DOA estimation is an important issue in array signal processing. The traditional methods for DOA estimation try to solve this problem with mathematical algorithms. For example, some of these methods are based on parameter estimation; such as DOA estimation methods using maximum likelihood estimation methods. Some of other traditional methods are based on subspace decomposition; Like the famous MUSIC method. The traditional methods of DOA estimation usually have a drawback, and that... 

Occurrence of natural disasters such as earthquake could seriously damage most buildings especially those with insufficient resistance located in urban worn-out textures. In order to reduce unpleasant consequences of an earthquake, appropriate policies need to be considered to persuade the beneficiaries to follow retrofitting standards in the process of planning, designing, and construction of buildings. These policies shall be implemented through institutions in arbitrary or obligatory forms, by encouragement or penalty mechanisms. In order to consider these policies, first of all we need to identify the beneficiaries and their particulars. By studying and considering subjects discussed in... 

Chemotherapy is a proven and effective systematic approach to treat various types of cancers. Despite its advantages, chemotherapy would kill healthy as well as cancer cells. To overcome this problem, different controlling strategies are implemented. This study aims to provide a medicine drug delivery schedule for chemotherapy (by designing a proper controlling system) based on the verifiable mathematical models. First, the dynamic model is analysed and stability points are reviewed. The selected model has five state variables and two inputs. In this study, the focus is on dynamic model analysis and obtaining an effective and appropriate treatment pattern by designing a proper controller. To... 

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... 

Due to the vulnerability of urban fabric and residential buildings to earthquakes and considering its destructive social and economic effects on society, the need to adopt appropriate policies to prevent and reduce vulnerability, has been increasingly considered by policy makers. Despite the laws, regulations, incentives and penalties that policymakers have envisioned to prevent unprincipled and unsafe construction, evidence shows that a significant number of new buildings being built in the country are not earthquake resistant and there are many violations in design, implementation and supervision that is done by the stakeholders. To solve this problem, research has been done on the... 

Soil and water pollution is one of the most common types of pollution in terrestrial and aquatic ecosystems. The development of mines and the oil and petrochemical industry on one hand and the non-compliance with environmental requirements on the other hand have caused large amounts of hydrocarbon pollutants and heavy metals to enter the environment in recent decades. Petroleum materials and heavy metals leak into the surrounding environment during drilling and extraction in oil sites and mines or during land and sea transportation, despite the measures taken to control their pollution. The conducted studies show that human industrial activities are the only cause of environmental pollution... 

The power control of horizontal axis wind turbines can affect significantly the vibration loads and fatigue life of the tower and the blades. In this thesis, we are going to consider both the power control and vibration load mitigation of the tower fore-aft vibration. For this purpose, at first, we developed a fully coupled model of the NREL 5MW turbine. This model considers the full aeroelastic behavior of the blades and tower and is validated by experiment results, comparing the time history data with the FAST (Fatigue, Aerodynamics, Structures, and Turbulence ) code which is developed by NREL (National Renewable Energy Lab in the United States). In the next, to estimate EWV, a novel... 

Laboratory studies to investigate the effects of different saline concentrations (such as sodium chloride or calcium chloride) on the soil water retention behavior of clayey soils and their volumetric changes have received much attention recently. However, many previous studies have investigated these effects in only one path of the SWRC (wetting or drying path) and the effects of saline concentration on hydraulic hysteresis have not been considered. In addition, researchers have frequently studied these effects on SWRC on clay samples, and little research has been done on collapsible soils. Therefore, the most important purpose of this study is to investigate the effects of increasing...