Sharif Digital Repository

This project presents algorithms for intelligent control of the viral load in a HIV-1 infection model. The first part of thesis was dedicated to the study of the three states model adopted to describe the HIV-1 infection. A sensitivity analysis of the model parameters was described and computer simulations were provided to show the influence of the parameters explicitly. Then, an internal model control based on neural networks was implemented on the introduced infection model with including the RTIs and PIs drugs efficacies as control input. A stable adaptive neuro-control approach was presented for affine in the control nonlinear dynamical systems, whose nonlinearities were assumed to be... 

Porosity and high surface area is a profound concept for creating advance materials. Nanofibers are an important class of nano materials which would be used as novel sorbents because of their high surface to volume ratio as a result of long lengths and nano-to-micro-scale diameters. Electrospining is a simple method for producing fine nanofibers from different meterials such as, polymers, composites and ceramics to prepare highly efficient sorbents. Moreover, electrospining has been developed for fabricating nanofibers with core-shell structures. These structures in compared with conventional fibers have gained higher attentions due to their high aspect ratios and flexiblity in surface... 

One of the most important requirements in deploying a security system is to ensure the effectiveness and absence of bypass patterns. This is especially important for attack-based detection systems. One of the systems that has recently attracted the attention of network administrators is Web Application Firewall (WAF). The purpose of this thesis is to propose a deep learning approach to identify the pattern of SQL Injection (SQLi) attacks which could potentially bypass a WAF. We delve into the problem of detecting SQLi attacks among a very large dataset of existing SQL queries. To this end, we use one of the latest implementation of Recurrent Neural Network (RNN) called Long Short-Term Memory... 

One of the main tools of the developing quantum technology is making the desired quantum gates and processes in the presence of the environmental noises. In this thesis, we first derive a Markovian master equation which defines purely the time evolution of the dynamics (process matrix) of the open system rather than its state (density matrix). This master equation indeed describes the time evolution of the Choi-Jamiolkowsli matrix which is independent of the state of the system at all times including the initial state. The n, by using this master equation we provide a scheme to manipulate optimally and locally the dynamics of the open system by external coherent agents. Such scheme... 

The main purpose in this thesis is the finite element simulation of thermal barrier coatings (TBC), subjected to residual stresses due to the coating process followed by thermo-mechanical fatigue loadings. This finite element modeling is performed in the ABAQUS software. In order to consider the actual condition of thermal barrier coating, models are defined based on a SEM image including real roughness and porosity of coating layers using image processing technique.
Two-step residual stress taking into account both coating process of bond coat and top coat layer is performed. Pre- heating of substrate and bond coat in order to reach comperessive stresses in coating layers has been... 

Phase noise is one of the important parameters in telecommunication systems and its measurement has always been considered. Digital phase noise measurement methods have a simpler implementation and calibration than analog types. Also, in digital methods, amplitude noise and phase noise can be separated and measured both at the same time. Comparing the phase noise of two oscillators with different frequencies is another major advantage of digital methods. The sensitivity of digital methods is limited to the noise of their analog-to-digital converters. Cross-correlation technique is used to reduce the minimum measurable level of phase noise. This method reduces the internal noise of the... 

The evaluation and selection of human resources is one of the most important management issues in organizations, and the importance of this issue increases when the evaluation and selection is related to managerial positions. Among the many methods that exist for evaluating and selecting human resources; The assessment center method is more useful for selecting candidates for management positions. The assessment center includes behavioral simulation exercises and competency where trained assessors observe and record behaviors and score competencies. The purpose of this research is to analyze and examine the fit of the model and the internal structure of the evaluation center in a government... 

Setar is a traditional Persian musical instrument. Nowadays, Setar is one of the most common musical instruments in Persian music. A systematic method for Setar production modification has not been introduced yet. This work is the first scientific work about analysis of this instrument. The aim of this study is to undertake early steps for Setar quality improvement. In this thesis, after analysis of the wood using in Setar construction, numerical and experimental methods have been utilized to analyze this instrument. After that, some works has been performed to extract an objective function which can judge about Setar quality. The results show good agreement between experimental and... 

Human activity recognition is an important and useful area in computer vision that application include surveillance systems, patient monitoring systems, human-computer interaction and analyse video data from big websites.Traditional Human action recognition use the RGB videos as default input that unable describe motion and action as full. On the other hand Kinect camera sendsthe RGB data to output in addition to the Depth Data that allows us to extract skeleton of human easily. Recently Space-time features have been particulary popular in RGB Videos because of their structure. These features are describedby their descriptor and send the good and important information to output.Finally we... 

With the advances in technology, Nowadays digital cameras are everywhere. As a result very large amount of images are on the web. Searching through these images intelligently and purposively is an essential need. Recently the possibility of retrieving images with some conceptual words along side of content based image retrieval has been studied in computer vision. For this purpose it’s required that for each image several words that describe its content be assigned automatically. One of the main problems for this task is semantic gap, meaning that the low level features such as color, texture,… don’t have the ability to describe the high level concepts in images which are comprehensible by... 

Melanoma is a malignant skin cancer which is caused by cancerous growth of melanocytes. If not treated at its early development stages, melanoma is the deadliest form of cancer. The best way to cure melanoma is to treat it in its earliest stage of development. Since a melanoma leasion is similar to benign moles (regaring its shape and appearance) at its early stages of development, it is often mistaken for moles and left untreated. Therefore, automatic melanoma detection can increase the survival rate of patients by detecting melanoma in its early stages. In this thesis, a new method for automatic diagnosis of melanoma using segmented dermoscopic images is provided. Almost all related...