Sharif Digital Repository

Recently, advances in the fabrication and integration of sensing, communication technologies and economical deployment of large scale sensor networks which are capable of large scale target tracking, become possible.therfore, the wireless sensor networks are a fast growing and marvelous research area that has attracted considerable research attention in the recent past. The creation of large-scale sensor networks interconnencting several hundered to a few thousand sensor nodes opens-up several wide range of application and technical challenges. Sensor nodes have been deployed to play significant roles in battlefield, disaster-prone area, traffic control, habitat monitoring and intruder... 

In this thesis, the effect of elastodynamic behaviour of an interceptor on it’s trajectory in space and accuracy in desired positioning and situation is investigated. The governing equations of motion are derived and linearized by using the basic equations of motion in the body frame axes and the mode summation method for elastic deformations. In order to control the interceptor, the closed-loop control on the yaw and pitch angles, is considered. The governing equations of motion are solved to determine the time response to investigate the structural effects on the stability, position and situation of interceptor. Finally, the effect of elasticity and vibrations on the interceptor’s... 

Complex networks have recently become a very noticeable subject because of their remarkable theory on real networks such as rumor spreading. This thesis contributes to a prevention strategy which uses a maximal clique algorithm to find overlapping communities and also uses inverse targeting immunization strategy to immune these communities. By the using maximal clique algorithm combined with inverse targeting strategy we have achieved that the TIK method (targeted immunization using k-clique percolation) obtains 10% of better immunization than HD (highest degree) method which is one of the best methods in targeted immunization strategies. The TIK also demonstrates that rumor spreading is... 

The main focus of this thesis is based on surface modification of polystyrene in order to prepare extractive phases appropriate for extraction of analytes with a wide polarity range. This goal was achieved by increasing surface polarity. In fact, improved wettability and the possibility of interaction with polar analytes after addition of functional groups on polystyrene surface were the main reason for increased extraction capacity. In the first research, different functional groups including amine, nitro, carboxyl and acetyl were added on polystyrene particles by chemical bonding and to investigate their influence on extraction process, 22 analytes with a wide polarity range (LogP=-2 to... 

Drug-target binding affinity prediction is one of the most important and vital part of drug discovery. The computational methods to predict binfing affinity is a standing challenge in drug discovery. State-of-the-art models are usually based on supervised machine learning with known label information. It is expensive and time-consuming to collect labeled data. This thesis proposes a semi-supervised model based on convolutional GAN (Generative adversarial networks). The model consists of two Gans and Two CNN blocks for feature extraction and fully connected layers for prediction. Gan can learn protein and drug features from unlabeled data. We evaluate the performance of our method using four... 

There are many methods for direction finding (DF) of radar targets, while the complexity and time elapsed calculation are their main drawbacks, thus the real time implementation of this methods are difficult. Artificial neural network (ANN) for DF is one of the optimum and good ways to implementation that have better result versus other techniques. In this thesis, direction finding problem for radar targets by using artificial neural networks have been studied. A new method is presented to detect the multiple targets simultaneously, that it can be implemented in digital form easily. Here one-dimensional DF by using uniform linear array (ULA) discussed and formulated, then the proposed... 

Behavioral investigation and control of multi-agent systems was one of the most attractive problems in robotics which has been studied since the middle of 20th century. Tracking a target is shown by many organic mechanisms during hunting and etc. and is one of the important topics of researches. In this thesis tracking a target by a multi-agent system has been considered which the agents are wheeled mobile robots and have non-holonomic motion constraints. A sample dimensionless and continuous time synchronous dynamic is proposed for the motion of these agents and the goal is to track a moving target while the agents create and keep a desired formation during their tracking process.... 

In this dissertation, an attempt has been made to prepare a library from most of the inorganic and organic compounds in order to strengthen the use of nanosystems for the purpose of controlled delivery and release of drugs and genetic material. In this regard, a complete set of compounds based on metal nanoparticles, layered double hydroxides, metal-organic frameworks, graphene oxide and carbon nanotubes were designed, synthesized and characterized, and nanocomposites and hybrids of them based on palladium, zinc, copper and nickel were designed as well. The nano-stable system is designed with positive surface potential, very low cytotoxicity, biodegradability and acceptable environment as... 

Ever growing users’ demand for higher mobile data traffic and a rise in the number of communicating devices in the network oblige operators to design novel schemes in order to respond to users’ requirements. The limited available frequency spectrum cannot handle this increased data traffic demand in cellular networks. It is estimated that by 2020 the amount of traffic in mobile networks, grows ten times more than mobile traffic in 2014. Data offloading is an existing approach that enables operators to support users’ demands. In this approach, in addition to utilizing Wi-Fi technology as a means to transfer data as well as conventional cellular communications, opportunistic communications... 

Characterizing cellular states in response to various disease conditions is an important issue which is addressed by different methods such as Large-scale gene expression profiling. One of the most important challenges in front of bioinformaticians is the loss of data because expression profiling is still very expensive. It is understood that profiling a group of selected genes could be enough for understanding all of the gene expression profile.In this research, we propose a fast method for estimation of the missing values inlow-rank matrices. We consider the highly correlated expression profiles as a low-rank matrix. Then, we used this new method in a proposed algorithm which will select... 

In much of the financial economics literature, banks are modeled as financial intermediaries that transfer household deposits to loan applicants. In these models, deposits are obtained from the accumulation of real amounts (household savings). In addition to this, another approach describes banks not as intermediaries of loanable funds, but as money-creators who do not need to accumulate deposit resources to lend. In this study, by modeling the money-creation behavior of the banking network, we try to answer the question that if the bank can create credit and purchasing power for the firm based on its future income, how will the general variables of the economy, including consumption and... 

Today, SAR radars are one of the most practical tools for controlling and monitoring surface targets, and so far, several methods have been proposed to create a profile image of the reflection coefficient of surface targets in these Radars. The main problem in these methods is the ability to simultaneously create a reflection coefficient profile image for stationary and moving targets. To create a profile image of the reflection coefficient of moving targets, first it is necessary to detect and estimate its kinetic parameters.This thesis presents a method for detecting and estimating Ground moving targets parameters using Keystone transfer conversion and also presents a method for creating... 

Today, current methods are used for treatment of cancers. Patient experiences a period of hard treatment during destruction of both healthy and diseased cells. Researchers are following stimulus- response drug delivery systems that they control time and position of drug release. Meanwhile, micellar nanoparticles are important, because it can transport the hydrophobic anticancer drugs from body's physiological barriers. On the other hand, tumour tissue has low pH and high temperature as compared to health tissue. Therefore, using pH and thermosensitive polymer coating could be effective in triggered drug release. In the first study, micellar systems were synthesized which were responsive to... 

In tissue engineering and nerve cell treatments, biocompatible and conductive substrates are needed to stimulate nerve cells. In this project, we fabricated a composite of polyaniline and gelatin along with metal-organic frameworks and graphene quantum dots, which perform this repair process for us. For this purpose, we used polyaniline. Due to its conductivity, this polymer stimulates the nervous tissue and in this way, it can perform the repair work. By conducting UV-Vis and FTIR tests, it was observed that the synthesis of aniline polymer has been achieved successfully. SEM analysis showed that the polymer chains were well formed. The other part of the composite used is MOF (metal-organic... 

Molecular communication (MC) is a new paradigm, in which the molecules or ions are used as information carriers. MC has been proposed as a promising approach for abnormality detection and localization in a variety of micro-scale and macro-scale applications in biotechnology, medicine, and industry; such as air pollutant monitoring, agriculture, abnormality detection in pipelines, and drug delivery. The goal in some of these works is to detect the tumors, viruses, and infectious micro-organisms in the body or leakage and pressure drop in pipelines. If these abnormalities are detected, the next step would be localizing them to finding a solution or treatment, e.g., drug delivery, or targeted... 

In the beginning of the 90’s a new type of robot was introduced by Fukuda. The brachiation is a type of mobile robot that moves from branch to branch like a long-armed ape. Here, as a new innovation, optimal control is used to obtain the optimal trajectories for two different problems. The first problem is “Brachiation between fixed branches with different distance and height” and the second is “Brachiating and catching the moving target branch”. Theoretical results show that the control effort in the proposed method is reduced by 25% in comparison with the “Target Dynamics” method which was proposed in prior articles for this robot. The obtained optimal trajectory also minimizes the... 

Target recognition techniques based on micro Doppler phenomenon are popular because they are applicable even on low resolution radars, in contrast to other techniques such as High Resolution Range Profile (HRRP) which need high resolution in range or angle. Usually, main purpose of such techniques is generating robust features against target initial state, velocity, aspect angle, etc. rather than features which exactly identify a target. Main approaches in the literature are based on time-frequency transforms (TFT) such as spectrogram in order to generate features to classify targets, but in this thesis, we propose a totally different method using Recurrence Plot for generating features... 

One of the most promising strategies for fighting cancer is the drug delivery process using synthetic nanoparticles. Once in biological milieu, the nanoparticle surfaces get covered with a layer of biomolecules called the “Protein Corona”. The protein corona formation changes the nanoparticles interaction with the human body dictating a new fate for them. The protein corona composition is not only dependent on the nanoparticle itself, but also it is affected by the health condition of patients as recently discovered through the experimental studies. Here, the effect of disease on the protein corona formation is discussed through the molecular dynamics simulations. A multiscale simulation... 

Recent drug delivery strategies have attempted to maximize the concentration of chemotherapeutic molecules into the tumors, while minimizing their systemic distribution. Doxorubicin has been widely used for a variety of cancers, successfully producing regression in acute leukaemia, lymphomas, soft-tissue and osteogenic sarcomas, paediatric malignancies and adult solid tumours, in particular breast and lung carcinomas. Common adverse effects of doxorubicin include hair loss, myelosuppression, nausea and vomiting, oral mucositis, oesophagitis, diarrhoea, skin reactions and serious reactions include hypersensitivity reactions, radiation recall, heart damage and liver dysfunction. Chitosan has... 

The oxidation-reduction (redox) responsive micelle system is based on a diselenide-containing triblock copolymer, poly(ε-caprolactone)-bis(diselenide-methoxy poly(ethylene glycol)/poly(ethylene glycol)-folate) [PCL-(SeSe-mPEG/PEG-FA)2]. Resulting in the development of tumor-targeted delivery for hydrophobic anticancer drugs. The diselenide bond, as redox-sensitive linkage, was designed, so it is located at the hydrophilic/hydrophobic hinge to allow complete micelles collapse and efficient drug release, in redox environments. The amphiphilic block copolymers self-assembled into micelles at concentrations above the critical micelle concentration (CMC) in an aqueous environment. Dynamic light...