Sharif Digital Repository

A high-Q tunable bandpass filtered amplifier structure is proposed which is based on N-path Q enhancement. Using Fourier series analysis, frequency response of an N-path filter and aliasing effect of this filter is achieved. This effect is caused by frequency translation to bandpass frequency as harmonic fold back (HFB). It is shown that using an additional N-path filter with the same clock frequency but different clock phase HFB is reduced. The conditions for fold back elimination are derived from Fourier series expansions for switched signals. In order to realize HFB reduction and increasing stop-band rejection and Q factor, an LNA associated with N-path filter is added to each of the... 

The airport terminal is difficult to plan and design due to the different components and the intricate complexity of its parts. At the airport terminal, we face a queue system which simulation is always a good way to analyze. In addition, computer simulation using modern softwares with the capability to model different types of systems, including the airport terminal, while being less realistic than analytical models, is less costly than operational Exercise.In this study, a supportive approach for better and specific management of Iranian airport terminal buildings with discrete-event simulation is proposed, considering the need for managing the airport terminals building in the country and... 

The increasing growth of marine tourism has strengthened the activities related to this industry. One of the most profitable of these activities is recreational submarines. A traction recreational submarine is an idea in this field, in order to reduce costs, the propulsion force is removed and the submarine is towed by the mother ship. The most important reason for using the traction system and removing the independent drive is to prevent vibration and noise caused by the rotation of the propeller to prevent the escape of aquatic animals and to create a beautiful view from under the sea to watch underwater wonders. Searching for safety and saving people's lives in emergency situations is an... 

Road casualty is the fourth leading cause of death in Iran after cardiovascular disease, cancer, and respiratory disease. Moreover, up to 7% of Iran’s Gross Domestic Product (- GDP) is spent annually on motor vehicle crashes’(MVCs) adverse outcomes. Recent studies have highlighted the role of anger and aggressive behaviors, while driving as two main predicters of MVCs. On the other hand, bus drivers and passengers, compared with the small number of registered buses in Iran, are more prone to fatal crashes than occupants of any other vehicles, based on the last WHO’s report. The aim of current research was to evaluate the influence of aggressive thoughts and behaviors on the road, driver’s... 

Road casualty is the fifth leading cause of death in Iran. To adopt proper countermeasures there is a need to evaluate the consequences of the implemented policies. Despite the development of crash time series models, these methods have not been in accordance with the multivariate, seasonal, and non-linear nature of crash data. On the other hand, the interpretable crash causal analysis frameworks are descriptive and they lack predictive power. Moreover, the unobserved homogeneity between observations has been widely overlooked in the crash causal analysis literature. This thesis introduces a novel causal analysis methodology by combining the interpretability and prediction power of the... 

Limited water resources in Iran have made dams an important part of the country’s infrastructure. As a result of the large number of in-progress and expected dam projects in the country, consideration of sustainability factors during planning, construction and operation phases of dam projects can create significant economical, social and environmental impacts in the long term. To come up with an inclusive sustainable development, new sustainability assessment approaches seek for sustainable development at the entire project’s life-cycle; they are looking for sustainable development at all design, construction, operation, maintenance and even demolition phases. In this research we have... 

Growing production of cement and concrete in developing countries like Iran in addition to high amounts of energy consumption and pollutants formation through production of cement has motivated researchers to partially replace it with suitable additive materials. In this study, the chemo-physical and microstructural properties of rice husk ash as an agricultural waste and its performance in cement mixtures as a pozzolan is experimentally investigated. Parameters influencing the pozzolanic properties of this material that are studied include the effect of acid leaching before pyro-processing, heating rate, temperature, retention time, and cooling rate. Additionally, this material is compared... 

In recent years, the incidence rate of liver cancer has increased sharply and nowadays liver cancer is known as the second leading cause of cancer death in the world. Surgical resection is usually used to treat malignant hepatic tumors. However, in some cases, surgical resection is not possible because of some reasons, such as tumor size and location. In these cases, other minimally invasive ablation methods such as radio-frequency ablation, microwave ablation, and high intensity focused ultrasound (HIFU) can be used. HIFU has some advantages such as noninvasiveness, high penetration depth, and low cost in comparison to the other ablation techniques such as radiofrequency ablation. In HIFU... 

Waveform design for Target identification and classification in MIMO radar systems has been studied in several recent works. While the previous works considered signal independent noise and found optimal signals for an estimation algorithm, here we extend the results to the case where clutter is also present and then we will find the optimum waveform for several estimators differing in the assumptions on the given statistics. Several different approaches to the optimal waveform design are proposed, including minimizing the error of MMSE estimator, minimizing the maximum error of the covariance shaping least square (CSLS) estimator and minimizing the MSE error of scaled least square (SLS)...