Sharif Digital Repository

Nowadays, advanced and inexpensive pre-clinical methods for investigating the effects of anti-cancer drugs are expanding. One of the latest three-dimensional laboratory modeling for evaluating the effects of drugs is the use of tumor-on-chip technology, which actually models the physiological system of the body through three-dimensional scaffolds, multicellular cultures, and shaped vascular systems. In this study, three-dimensional culture of cancer cells was performed in the form of spheroids. A chip of U-shaped microstructures with and without gaps was used to trap cells and form cancer spheroids. We simulated the simultaneous effect of drug and oxygen concentration distribution inside the... 

To actualize and making the outputs of a project effectual, it is necessary to conduct an effective management during a project. This case may not be possible without accurately planning for activities, management and controlling all phases of a project ignoring the risk management of that project. If risks of a project cannot be detected before conducting a project, it is possible to challenge the performance and even effectiveness of the project. In current conditions, the most important problem of managers and executives of construction projects through the country is risk management of projects, not acknowledging with definitions of risk, models of risk management and lack of a model for... 

Optomechanical systems have attracted considerable attention in the last decade. Such a raising prominence is mainly due to its capability in providing new insight into the quantum behavior of macroscopic objects and exploring the interface between quantum and classical mechanics. Alongside this fundamental quest, cavity optomechanics has many other benefits, ranging from very precise measurements on forces and positions to quantum information processing. In this thesis, we investigate quantum properties of such systems. Particularly, we study cooling of the mechanical resonator toward its ground state and the entanglement between this mechanical resonator and the cavity field. Cooling the... 

As the number of processing cores on a single chip continues to grow, the need for a high band width, low power communication structure, will be the most important requirements of next generation chip multiprocessors. Today, a major part of power consumption in multi core architectures belongs to interconnects. Due to these facts, reducing consuming power, as well as supporting high performance, is concerned in these architectures. The concept of “network-on-chip” emerged to improve the performance of CMPs. But now a day, considering the circumstances of power budges, it’s incapable of presenting new strategies to decrease consuming power and delay. However, optical interconnects have the... 

In 1953, Landau expressed the conditions for the existence of tournaments with a prescribed score vector R. Eleven years later, Ryser proposed an algorithm for constructing the tournament matrix with score vector R and showed that any two tournaments with the same score vector can be obtained from one another by a sequence of 3-cycle switches. Last year (2014) Brualdi and Fristcher explained in an article, similar to this process, the existence of, algorithm and switches for loopy tournament and Hankel tournament and similar structure skew-Hankel tournament. This paper is discussed in a chapter of this thesis. In 1991, De Caen found a lower bound for the real rank of a tournament matrix.... 

We design a new algorithm for clustering data streams in any fixed di- mension, that use the framework of core-set to summarize data, in order to reduce the complexity of computation. Clustering is to separate data into distinct sets called clusters, which objects in the same cluster has the most similarity and objects in the different clusters has the least similarity.This problem has many application in the areas such as: machine learning,image processing, financial and stock transactions. Data stream has recently emerged as an important concept because in many applications, data is inherently streaming over a network or the data base is extremely large and sequential access is way faster... 

Condition monitoring of a system refers to the process of measuring and analyzing the aging indicators of critical components of a system that can be harnessed to estimate the system’s health. One of the main interests in condition monitoring is to performing the scheduled maintenance activities for the system. Monitoring the status of the system reduces maintenance costs and prevents unwanted contingencies and outages in the system.
In power electronics, the capacitors are the most critical components of the system from the point of reliability. Capacitors are the leading cause of failure in the power electronic converters so, this essay attempts to attain a solution to monitor the... 

Ethylene-propylene-diene monomer rubber (EPDM) is one of the elastomers that shows non-polar behavior, high elasticity at low temperatures, excellent thermal and ozone resistance, and high electrical resistance. In this respect, it is used in various applications such as sealing materials, conveyor belts, waterproof materials, cables, etc. One of the most important applications of this rubber is its use as a sealing material. In this case, the resilience behavior plays an important role in the sealing behavior of the EPDM rubber. Especially in cases such as the car's hydraulic braking system where high service temperatures and dynamic stresses are applied, resilience behavior will be more... 

The aim of this study was to develop a method to determine the trace residual amounts of nonsteroidal anti-inflammatory drugs in meat-related samples and to study the effect of different cooking methods and storage conditions of meat before cooking as an effective factor on the fate of these drugs. To proceed this goal, a nanocomposite was prepared from polycaprolactone nanofiber/silica mesopores as green sorbent by electrospinning. The synthesized nanocomposite was implemented for micro-solid phase extraction of the desired drugs in conjunction with high performance liquid chromatography. Polycaprolactone, due to its excellent physical properties, availability, biodegradability,... 

In this study, at first modeling of a self-propelled microrobot and its hydrodynamic effects on flow field are investigated. Then, a cascade controller has been designed for the fully actuated microrobot in order to track the desired time trajectories. Next, in order to design an optimal controller to decrease energy consumption, regardless of tracking the desired orientation trajectory compared to the desired position trajectory, the fully actuated microrobot would change to over actuated microrobot. Thus, it would be able to orient freely itself according to the flow field so that reduce the energy consumption. By applying the optimal controller on the over actuated microrobot, it was... 

The retina, a photosensitive area in the central nervous system, is delicate and intricate. It is susceptible to degenerative disorders such as age-related macular degeneration (AMD), retinitis pigmentosa (RP), Stargardt disease (SD), and glaucoma. These diseases can lead to severe vision loss and ultimately irreversible blindness by causing destruction or dysfunction of different types of retinal cells. Unfortunately, there are no proven treatment strategies to cure or reverse these degenerative disorders. However, cell transplantation therapies may be an alternative to replace distorted cells and improve an individual's vision. Recent clinical outcomes show that transplanted cells in the... 

Cardiovascular diseases are one of the leading causes of death worldwide. Despite significant advances in therapeutic interventions for these diseases, the pathophysiology remains incompletely understood. Challenges in drug evaluation include the lack of appropriate clinical trials, such as conventional 2D cell cultures and animal studies, as well as the absence of model systems that can provide complex and patient-specific cardiac functions for diagnosis. Organ-on-a-chip devices have the potential to mimic the body's response to treatments by utilizing microscale cell culture fluid connections and creating realistic models of human organs of interest. Our objective is to develop a... 

Modeling and performance evaluation of the real time distributed systems is a significant problem. Stochastic activity network is one of the high level models used for this purpose. This network is an extension of generalized stochastic Petri net which is more powerful and flexible than other Petri net extensions. Checking the satisfiability of properties such as performance, dependability and user's expected properties is considerable in these models. Thus, using the approaches and generating modeling and model checking tools with the mentioned purpose is attractive. A model checker automatically checks the correctness of the system behaviors as properties against the model by getting the... 

This study has focused on the important problem of landing on a planet as an important current and future space mission. In this regard, dynamics modeling and integrated state estimation and control problems have been investigated in different views. To this aim, first a novel concurrent representation for translational and rotational kinematics has been developed based on the extension of modified Rodrigues parameters to dual space. This parameter set, called dual modified Rodrigues parameters (DMRP), is then utilized to establish an integrated roto-translational dynamic. The proposed DMRP-based kinematics and dynamics have been verified via comparison to traditional methods of... 

Prevalent deployment of Distributed Energy Resources(DERs) in the demand side of electrical energy grids has several advantages such as greenhouse gases emission reduction, mitigation of power losses in the distribution grids and abatement of the dependency on the wholesale generation companies. At the same time, it paves the way for the advent of local interactive energy trading frameworks. In the following thesis, a distributed data-driven algorithm is developed for market-clearing in a community-based local energy market. The social welfare maximization is considered as the objective of the energy trading. The production and demand of electricity are the decision variables of sellers and... 

Understanding biological systems requires extensive knowledge of individual parameters, and to study the processes of cell differentiation and cell behavior, a suitable environment must be created with the physiological conditions of the human body. For this purpose, with the knowledge of microfluidics, a microenvironment can be provided to study the behavior of cells on a small scale. The use of bone tissue model microfluidic chips is an alternative and new method in which it is possible to study the behavior of cells to differentiate into bone and to examine the toxicity of drugs, which in itself can help in the effective and successful treatment of these cases show. Therefore, in this... 

The main topic of this research is the navigation and control of a free-flying satellite with a robot manipulator while transferring and placing cargo on a space station. After connecting the cargo module, astronauts and robots need to deliver the available loads to the desired modules in a space station. Capturing an object or cargo is a critical issue studied extensively so far. However, delivery and placing of the cargo at the target point have not been investigated yet, to the best of the author’s knowledge; hence, this is a primary motivation for conducting the proposed research. After capturing the payload, the position and attitude of the manipulator with respect to the station’s...