Sharif Digital Repository

Recently, the computational algorithms underlying in the nervous system of vertebrates have been attracting scientists and engineers. Therefore, a number of artificial learning methods are proposed for mathematical interpretation of these algorithms. In this thesis, by investigating the latest findings about the nervous system, and the motor system in particular, a novel machine learning scheme inspired by human motor learning is proposed. Basic theoretical aspects of this method in conjunction with some of state-of-theart artificial learning methods are discussed. Finally, this method is evaluated in a variety of engineering problems ranging from curve fitting and function approximation to... 

How the human nervous system works is one of the most important topics in science and in this topic providing a model of it is scientists' main concern. The human brain that has been formed from a large number of nerve cells lets it do complex computations. The structure of cognition, memorizing and processing which are some of human features are being studied in many fields of science named "brain and cognitive science".
In this study, we will point to modeling of one of the human cognitive phenomena (decision making in problem solving). In this modeling, we aim to connect the microscopic and macroscopic levels of the nervous system to each other.
First, we will give an introduction... 

According to needs for high quality pictures with high compression, in variety of applications such as Satellite communications, in this thesis some parts of JPEG2000 standard with computation and time complexity, have been implemented on FPGA. This parts are:
1- Two dimensional Discrete wavelet transform (2D-DWT)
2- Bit Plan Coding
3- Context-based Adaptive Binary Arithmetic Coding (MQ-Coder)
Each of these parts is implemented on basis of the best architectures in papers with some improvement on its hardware; and the results are compared with other similar works. Other parts, such as “Packet Creation” that are intrinsically software-based, are not implemented and it is... 

The charged particles in space strike the silicon surface of an embedded system in a satellite and cause fault occurrence in its operation. So some methods should be employed to reduce the effects of the faults. The methods that are implemented in system level are widely used because of their low cost and high reliability. The processors are responsible for performing main processes in embedded systems. On the other hand, the ARM processors are good choices for utilizing in satellites because of their low size, low power consumption and high performance. Also, FPGAs have made a major improvement in embedded system design. So with implementing ... 

The main idea in this project is investigation of multidimensional recording brain signal (ECoG) for estimation of 3D arm trajectory. First we introduce a general structure with variable blocks, in this structure we have many ways to estimate hand trajectory and obtain different result. By statistical test we find the best state of this structure and apply it on other dtae set trials. Electrocorticography (ECoG) has seen recent use in this regard because it offers a higher spatiotemporal resolution than non-invasive EEG and is less invasive than intracortical microelectrodes and have been shown to contain reliable information about the direction of arm Trajectory and movements. We using... 

Parkinson's disease is a degenerative disorder of the central nervous system. The motor symptoms of Parkinson's disease result from the death of dopamine-generating cells in the substantia nigra. The cause of this cell death is unknown. Early in the course of the disease, the most obvious symptoms are movement-related. Some of the symptoms are: shaking, rigidity, slowness of movement and difficulty with walking and gait. Modern treatments are effective at managing the early motor symptoms of the disease, mainly through the use of levodopa and dopamine agonists. As the disease progresses these drugs eventually become ineffective and produce a complication called dyskinesia, marked by... 

Face recognition is one of the best biometrics in computer vision. Although researchers introduced this method many years ago, the most important improvement has occurred in the biometrics last decade. Face recognition was employed in areas such as passport checking, security issues and identification. It facilitates our daily life as we use it in our mobile phones and computers for unlocking our devices. Many approaches were employed in the face recognition applications. Some of them were single-modal like PCA, ICA and LDA and some others were multimodal like Visual + 3D or 3D + IR. Still, most of Face recognition methods suffer from environment changes like variations in illumination and... 

Reliable communication has become very crucial in the transmission applications. Hence, to design hardware to handle reliability is the most important part of communication. In this work, we propose a new secured ALU (Arithmetic and Logic Unit) against fault attacks that is used in ARM processor which can correct any 5-bit error in any position of 32-bit input registers of ALU. We also designed a BCH (Bose, Chaudhuri, and Hocquenghem) codec (encoder, decoder) using the prototyping FPGA. Further, in this thesis we designed (63, 36) the BCH encoding and decoding system to tolerate the 5-bit faults. The codec system and ALU system are based on using Verilog description language. Since... 

Growing need for the use of modern technologies in the field of information and communication reveals the necessity to establish an information security management system more than before. It is totally proven that information is an asset which, like other important assets of the organization is so momentous that should be crucially protected. Nowadays, with the proliferation of security threats, which can lead to undesirable events with possible damage to systems or organizations intentionally or inadvertently, by human factors or inhuman cause, existence of a safe structure has become more necessary for all organizations and agencies. One of the most critical areas of information security... 

Cardiovascular diseases are currently the most common disease and the first cause of death in Iran and the world. It will increase in the future due to improper diet and lifestyle. Therefore, the prevention and treatment of these diseases is very important for the health of the country. One of the effective ways to diagnose heart diseases is to analyze the electrical signals of the heart and detect heart rhythm irregularities from it. The electrical signal of the heart called ECG is created by the electro-mechanical activity of the atria, ventricles and the valves between them. Therefore, this signal is useful for detecting the correct functioning of different parts of the heart and... 

To capture what is really done on the computer, we have decided to simulate the behavior of an Intel processor based computer. The main part of a computer is its CPU, so we are have simulated the Intel processors from 8086 to Pentium with MMX, SSEX and 3DNow. To work with hardware and software and going back to these steps for several times, is a time consuming procedure. To avoid falling in such loops, one way is to simulate the hardware and develop the software according to this simulation. This remedy solves time consuming procedure since changing hardware in simulation is quite easy. To simulate the digital systems, we need to have the software codes of the processors. Since the Intel... 

Neural prostheses (NPs) based on capacitive coupling method including sur-face NPs, implanted or subcutaneous NPs and Stimulus Route System (SRS) are the common NPs used for rehabilitation applications. SRS is a kind of capacitive coupling and the latest version of the mentioned neural prosthesis used for restoring sensory and motor functions caused by spinal cord and brain disorders. In addition to some superiorities of capacitive coupling compared to other methods (inductive coupling, batteries, energy harvesters and so on) such as at plates structure and consequently ease of manufacturing, ability to transfer data and power with different operating frequency and hence remov-ing... 

Methamphetamine (meth) abuse and addiction (MA), with its serious medical, psychiatric and social complications, is a growing national disaster in Iran. Response control deficit during exposure to drug related cues is one of the main neurocognitive cores in MA and results in continued drug use and treatment failure. There have been many studies focused on cue exposure, but most of their paradigms required subjects to passively view the cues; this aspect of these paradigms cause a wide gap between reality and experimental studies. Developing a functional and structural neuroimaging protocol to map realistic brain circuits that are involved in craving among meth users is of importance.... 

Diffractive deep neural network is an optical machine-learning framework that uses diffractive surfaces, optical devices, electro-optic devices and engineered matterials to optically perform computational tasks. These diffractive networks, after their desing and train phase by computers and machine learning algorithms, are physically fabricated using 3D printing or lithography, to actualize the model of trained network. Machine learning processes and alghorithms are performed through light-matter interaction and diffraction of light. This procedure is done at the speed of light and without the need of any power, except for the light illumination for the input object. In comparison with... 

Today, the use of radar technology and its various applications in different areas of science is no secret. The developed countries are looking to increase their ability to use new radar tools. Synthetic aperture radar is one of the most modern and efficient equipment imaging of the surface. One of the major advantages of synthetic aperture radar is imaging capabilities at night and bad weather conditions if the imaging methods used in the camera have limitations in night and bad weather conditions. There are different methods for extracting the images, one of the most important algorithms is Range Doppler Algorithm which is used to obtaining images from raw data received. Because of the... 

Positron Emmision Tomography is one of the most important methods in molecular imaging field. One of the challenges over PET imaging is the resolution of reconstructed images. To overcome this problem, one can use more exact image reconstruction methods called, iterative methods. It has been showed that Iterative methods like MLEM have advantages over Analytical ones. Main drawback of iterative methods is time consuming computation. Then you should reduce the image reconstruction’s time for clinical time constraints. Using Graphic Proccessing Unit for accelerating computational works, raised in recent years. In this work, we used GPU for accelerating pet image reconstruction and simulation... 

Advanced control techniques are required to achieve a cost-effective and reliable use of the wind power generation. The wind turbines are generally controlled based on two control objectives: the turbine protection and the generation of acceptable power for the utility grid. These objectives are achieved if the control inputs are applied based on appropriate control logics. In this work, a nonlinear multivariable model of the wind turbine with a DFIG generator is considered. The rotor speed and the d-axis rotor current (as the control outputs) are controlled via manipulation of the two generator voltages (as the control inputs) in low wind velocity condition. For high wind velocity, the... 

One of the important tools that we frequently use in life is the map. In every day movements we can use the maps in order to navigate and find our way. We also utilize the maps to find out more about our surrounding world. GIS is the key technology which can help us reach these goals. In GIS generally there are 2 methods for representing geographic data, these methods are Raster and Vector data representation. In this thesis our purpose is to find another way for representing GIS data by using vector format. In this new representation we can access to information which are not accessible in regular maps. So we generate a new flexible platform for GIS data. Thus in order to represent new... 

According to the World Health Organization, about 35% of deaths worldwide are due to cardiovascular diseases, therefore the evaluation of vascular endothelial function has great prognostic and diagnostic value for cardiovascular diseases. The conventional noninvasive method for endothelial function evaluation is the measurement of flow-mediated dilation in brachial artery using ultrasound imaging (FMD-US). As the accuracy of FMD-US depends on the operator's skill and the resolution of the ultrasound images, this method has not been adopted. In this work, we propose to use a low cost, easily-accessible surrogate signal, the photoplethysmogram (PPG) to implement the FMD test. Whereas previous... 

Development of the fMRI imaging method gives the scientists the opportunity to record functional images from the brain with high spatial resolution and several researches were conducted on this field. Autistic people’s brain has functional differences with normal people. In this paper these differences have been studied. At first fMRI datasets from autistic subjects and control have been recorded and preprocessed. Then the independent components from these datasets have been extracted using group ICA method. Any independent component is an image depicting a brain network. There is a time series for each image which shows the temporal variations of each component. In the next step, the...