Dynamic stability and control of a novel handspringing robot

, Article Mechanism and Machine Theory ; Volume 137 , 2019 , Pages 154-171 ; 0094114X (ISSN) Zabihi, M ; Alasty, A ; Sharif University of Technology

Elsevier Ltd 2019

Abstract

In the field of mobile robotics, legged locomotion plays an essential role in transporting robots over various terrain types. A significant portion of research on legged robots has been focused on one-legged robots. In contrast with different types of locomotion of multi-legged robots, one-legged robots have only one type of motion, called hopping. Hopping motion, as a type of hybrid behavior, is generally comprised of flight and stance phases. Dynamic stabilizing of hopping motion provides a challenging control problem because of its nonlinear and hybrid behavior. The majority of one-legged hopping robots investigated so far are only capable of hopping with one side of their leg. In this...

The Effect of Cementation by Lime on Collapsible Soils Behavior Using Suction Controlled Oedometer Device Case Study: Loess of Gorgan

, M.Sc. Thesis Sharif University of Technology Zabihi, Nina (Author) ; Haeri, Mohsen (Supervisor)

Abstract

Collapsible soils such as loess, which are naturally found unsaturated, are kind of problematic soils that undergo sudden and noticeable decrease in volume under increasing stress at constant moisture, increasing moisture at constant stress, or increase in both of them. This kind of soil can be found in some parts of Iran such as plain of Gorgan. To fulfill the main purpose of this study, evaluating the effect of cementation on collapse behavior of loess of Gorgan, some oedometer tests under controlled matric suction were performed on reconstituted samples without and with lime. The lime was added for stabilizing of the collapsible materials and the amount was chosen to be %3 by weight of...

Design of Fault-tolerance Mechanisms for Soft Multiprocessors

, M.Sc. Thesis Sharif University of Technology Zabihi, Masoumeh (Author) ; Miremadi, Ghasem (Supervisor)

Abstract

Increasing complexity of embedded systems and the need for more computation powerhave directed designers toward using of multiprocessors. SRAM-based FPGAs are suitable platforms for implementation of multiprocessors due to thier low cost, fast time-to-market and re-configurability. FPGA-based multiprocessors are known as soft multiprocessors. The large area of SRAM-based FPGAs is occupied by configuration bits. Configuration bits are vulnerable to high energy particles that can lead to soft errors. In this regards, it is of decisive importance to protect soft multiprocessors against soft errors. This thesis proposes a fault-tolerant method for soft multiprocessors that can detect and...

Design of Power Distribution Network in 3D ICs Thesis Submitted

, M.Sc. Thesis Sharif University of Technology Zabihi, Masoud (Author) ; Sarvari, Reza (Supervisor)

Abstract

Delay of Interconnects in modern digital ICs is several times greater than delay of gates. One proper measure for this problem is to shorten interconnects length by using three dimensional structures instead of conventional two dimensional structures. In these structures TSVs (Through Silicon Vias) make connection between stratums. Power integrity in 3D ICs necessitates power distribution networks to have minimum IR drop and Ldi/dt noise. In this dissertation we design power distribution network considering IR drop and Ldi/dt noise margin. We expand a mathematical model which represents differential equation of power distribution in the surface of each stratum. Using this expanded model we...

Allocation and Determining the Optimal Capacity of Installing Renewable Power Plants in A Region Based on A Global Harmonic Index

, M.Sc. Thesis Sharif University of Technology Zabihi, Alireza (Author) ; Mokhtari, Hossein (Supervisor)

Abstract

Considering the increasing development of renewable power plants including solar and wind power plants in the country, the need to investigate the effects of these power plants on the power grid is more needed and attention than before. Since these power plants are connected to the distribution network by means of power electronics, this problem has caused the injection of harmonics into the network, which can be transferred to higher voltage levels (upper distribution and transmission network). Harmonics in networks cause increased losses and reduced efficiency, false operation of protective relays, and damage to equipment due to the creation of harmonic intensifications. The purpose of...

Modeling and Control of One-legged Somersaulting Robot

, M.Sc. Thesis Sharif University of Technology Zabihi, Mehdi (Author) ; Alasty, Aria (Supervisor)

Abstract

Inspired by the agility of animal and human locomotion, the number of researchers studying and developing legged robots has been increasing at a rapid rate over the last few decades. In comparison to multi-legged robots, single-legged robots only have one type of locomotion gait, i.e., hopping, which represents a highly nonlinear dynamical behavior consisting of alternating flight and stance phases. Hopping motion should be dynamically stabilized and therefore, presents challenging control problems. A large fraction of studies on legged robots have focused on modeling and control of single-legged hopping machines. In this research, somersaulting is introduced as a kind of hopping motion for...

Application of Machine Learning Algorithms in Analysis and Prediction of Football Goalkeepers Performance and their Valuation in the Transfer Market

, M.Sc. Thesis Sharif University of Technology Zabihi, Matin (Author) ; Radman, Maryam (Supervisor)

Abstract

Football transformation into an industry with extraordinary financial flow has made this popular sport an attractive field for sports analysts. The development of the computer science and data science has led to the emergence of a concept called football match analysis. The goalkeepers, as a unique member of football teams and regrading their unique features and characteristics, play a crucial role in the outcome of competitions and the success of the teams. Therefore, analysis of various aspects of their performance is one of the essential issues in the application of data science in football. In this research, three separate parts have been studied. In the first part, by using pre-match...

Studies on the catalyst preparation methods and kinetic behavior of supported cobalt catalysts for the complete oxidation of cyclohexane

, Article Reaction Kinetics, Mechanisms and Catalysis ; Volume 114, Issue 2 , Jan , 2015 , Pages 611-628 ; 18785190 (ISSN) Zabihi, M ; Khorasheh, F ; Shayegan, J ; Sharif University of Technology

Springer Netherlands 2015

Abstract

Low cost dispersed supported cobalt oxide nanocatalysts on activated carbon (AC) were prepared by two different methods: (1) combined impregnation and deposition–precipitation (IMP-DP) and (2) heterogeneous deposition–precipitation (HDP). XRD, TEM, FESEM, BET and Boehm techniques were used for the characterization of the support and the catalysts. Characterization analyses indicated the negative effect of the wet impregnation method on the IMP-DP technique for the preparation of catalysts for the total oxidation of cyclohexane in air. The catalysts prepared by HDP and IMP-DP methods were found to have significant differences in oxidation activity, morphology, particle size, and shape of...

Supported copper and cobalt oxides on activated carbon for simultaneous oxidation of toluene and cyclohexane in air

, Article RSC Advances ; Volume 5, Issue 7 , Dec , 2015 , Pages 5107-5122 ; 20462069 (ISSN) Zabihi, M ; Khorasheh, F ; Shayegan, J ; Sharif University of Technology

Royal Society of Chemistry 2015

Abstract

Copper and cobalt oxides supported on almond shell derived activated carbon (AC) with different loadings were synthesized by sequential and co-deposition-precipitation methods leading to Cu(shell)/Co(core)/AC, Co(shell)/Cu(core)/AC and Cu-Co(mixed)/AC catalysts that were subsequently used for catalytic oxidation of gaseous mixtures of toluene and cyclohexane in air in a tubular flow reactor. The catalysts and the support were characterized by Boehm test, Brunauer-Emmett-Teller (BET) surface area, X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy...

Power delivery solutions in 3-D processor-DRAM systems in presence of hot spots

, Article 2014 IEEE 23rd Conference on Electrical Performance of Electronic Packaging and Systems, EPEPS 2014, 26 October 2014 through 29 October 2014 ; Oct , 2014 , Pages 207-210 ; 9781479936410 (ISBN) Zabihi, M ; Radfar, F ; Sarvari, R ; Sharif University of Technology

Institute of Electrical and Electronics Engineers Inc 2014

Abstract

An important application of 3-D integration technology is stacked processor-DRAM systems. One of the major design issues in 3-D processor-DRAM stacks is power delivery. Presence of hot spots, high density power regions, in processor die poses serious challenges to the design of power distribution network (PDN). In this paper, we investigate solutions to ensure power integrity in the hot spot regions

Nanocapsules based on carbon nanotubes-graft-polyglycerol hybrid materials

, Article Nanotechnology ; Volume 20, Issue 48 , 2009 ; 09574484 (ISSN) Adeli, M ; Mirab, N ; Zabihi, F ; Sharif University of Technology

2009

Abstract

In this work the effect of a conjugated macromolecule on the conformation of CNT was studied. Typically polyglycerol (PG) was covalently grafted onto the surface of multi-wall carbon nanotubes (MWCNTs) and MWCNT-graft-PG (MWCNT- g-PG) hybrid materials were obtained. Dynamic light scattering (DLS) experiments showed an average diameter around 100nm for MWCNT- g-PG hybrid materials in water. The difference between this size and the expected size for MWCNT- g-PG hybrid materials (the length of pristine MWCNTs was several micrometers) was assigned to the effect of the grafted PG on the conformation of MWCNT in the solution state. Transmission electron microscopy (TEM) evaluations showed a change...

Investigating the Effects of Specimen Size and Dimensions Ratio on Compressive Strength of Concrete

, M.Sc. Thesis Sharif University of Technology Zabihi, Alireza (Author) ; Kazemi, Mohammad Tagi (Supervisor)

Abstract

Concrete is one of the most widely used building materials. Compressive strength of concrete is the most important property in designing reinforced concrete structures. Compressive strength test should be carried out on specimens with standard dimensions. In practice, dimensions of structural elements could be different from the dimensions of standard specimen. The dimensions’ ratio influences the strength of concrete specimen and the coefficient of strength variation. In the present study it is tried to obtain a meaningful relationship between size and strength based on the results of the tests on the specimens with different dimension ratios. Specimens examined in this study are C25 grade...

Design and Hardware Implementation of Optical Character Recognition

, M.Sc. Thesis Sharif University of Technology Dezfuli, Sina (Author) ; Hashemi, Matin (Supervisor)

Abstract

The objective of OCR systems is to retrieve machine-encoded text from a raster image. Despite the abundance of powerful OCR algorithms for English, there are not many for Farsi. Our proposed algorithm is comprised of pre-processing, line detection, sub-word detection and segmentation, feature extraction and classification. Furthermore, hardware implementation and acceleration of this system on a GPGPU is presented. This algorithm was tested on 5 fonts including Titr, Lotus,Yekan, Koodak and Nazanin and an average accuracy above 90% was achieved

Design and Efficient Hardware Implementation of Spiking Neural Networks on FPGA

, M.Sc. Thesis Sharif University of Technology Amirshahi, Alireza (Author) ; Hashemi, Matin (Supervisor)

Abstract

Spiking Neural Networks(SNN) are networks which are consisted of layers of neurons, like other typical artificial neural networks. The main difference between SNN and other neural networks is the type of data transportation among neurons which is done by spikes. Spiking neural networks and their models are considered as the nearest networks and neurons to animals’ nervous systems. In aspects of hardware implementation, the type of data transportation in SNN causes them to be ultra-low power. So, implementation of these networks on chips like FPGA and also usage of SNN in applications with high processing load have startling germination, recently. In this work, we have tried to propose some...

Disentangled Representation Learning for Automated Clothe Image Synthesis on the Body

, M.Sc. Thesis Sharif University of Technology Johary, Iman (Author) ; Hashemi, Matin (Supervisor)

Abstract

There have been many works on generative networks and image generation in the past few years, but the problem with this work is that there is no control over the generated images. The goal of disentangled image synthesis is to generate new images with specific detail and have control over the generated images. Image-based virtual try-on aims to synthesize the customer image with an in-shop clothes image to acquire seamless and natural try-on results, which have attracted increasing attention. The main procedures of image-based virtual try-on usually consist of clothes image generation and try-on image synthesis. In contrast, prior arts cannot guarantee satisfying clothes results when facing...

Efficient Implementation of Compressed Deep Convolutional Neural Networks

, M.Sc. Thesis Sharif University of Technology Afshar, Mohammad (Author) ; Hashemi, Matin (Supervisor)

Abstract

Many mobile applications running on smartphones, wearable devices, tiny autonomous robots and IoT devices would potentially benefit from the accuracy and scalability of deep CNN-based machine learning algorithms. However,performance and energy consumption limitations make the execution of such computationally intensive algorithms on embedded mobile devices prohibitive.We present a GPU-accelerated engine, dubbed mCNN, for execution of trained deep CNNs on mobile platforms. The proposed solution takes the trained model as input and automatically optimizes its parallel implementation on the target mobile platform for efficient use of hardware resources such as mobile GPU threads and SIMD units....

Parallel Implementation of Telecommunication Decodings in Real-time

, M.Sc. Thesis Sharif University of Technology Jafarzadeh, Ali (Author) ; Hashemi, Matin (Supervisor)

Abstract

Many chip manufacturers have recently introduced high-performance deep-learning hardware accelerators. In modern GPUs, programmable tensor cores accelerate the heavy operations involved in deep neural networks. This paper presents a novel solution to re-purpose tensor cores in modern GPUs for high-throughput implementation of turbo decoders. Turbo codes closely approach Shannon’s limit on channel capacity, and are widely used in many state-of-the-art wireless systems including satellite communications and mobile communications. Experimental evaluations show that the proposed solution achieves about 1.2 Gbps throughput, which is higher compared to previous GPU-accelerated solutions

Design and Implementation of GPU-based MLOps Cloud Platform

, M.Sc. Thesis Sharif University of Technology Yarian, Abolfazl (Author) ; Hashemi, Matin (Supervisor)

Abstract

In the current era, artificial intelligence and machine learning have become vital and widely used technologies across various industries. These technologies enable companies and organizations to optimize processes, predict trends, and uncover hidden patterns in data with high accuracy and speed. However, fully leveraging the capabilities of AI and ML requires the effective and eﬀicient deployment of ML models in production environments. MLOps, a combination of DevOps and ML concepts, aids in managing the lifecycle of ML models from development to deployment and maintenance. In this research, due to international sanctions and limited access to external services such as Google Vertex AI,...

A partial task replication algorithm for fault-tolerant FPGA-based soft-multiprocessors

, Article CSI Symposium on Real-Time and Embedded Systems and Technologies, RTEST 2015, 7 October 2015 through 8 October 2015 ; October , 2015 , Page(s): 1 - 7 ; 9781467380478 (ISBN) Zabihi, M ; Farbeh, H ; Miremadi, S. G ; Sharif University of Technology

Institute of Electrical and Electronics Engineers Inc 2015

Abstract

FPGA-based multiprocessors, referred as softmultiprocessors, have an increasing use in embedded systems due to appealing SRAM features. More than 95% of such FPGAs are occupied by SRAM cells constructing the configuration bits. These SRAM cells are highly vulnerable to soft errors threatening the reliability of the system. This paper proposes a fault-tolerant method to detect and correct errors in the configuration bits. The main of this method is to analyze the scheduled task graph and select a subset of tasks to be replicated in multiple processors based on the utilization of the processors in different execution phases. To this end, 1) errors are detected by re-executing a subset of tasks...

Viterbi Decoder Implementation on GPGPU

, M.Sc. Thesis Sharif University of Technology Mohammadidoost, Alireza (Author) ; Hashemi, Matin (Supervisor)

Abstract

In this project, a method is emoloyed to implement a Viterbi decoder on GPGPU. This method is based on combining all steps of the algorithm. This combination has some challenges that are related to differences between different steps of the algorithm. So in this project, some solutions are found to handle these challenges and a high-throughput Viterbi decoder is acheived