An introductory course on differentiable manifolds

, Book Shashahani, Siavash

Dover Publications, Inc 2016

Abstract

Based on author Siavash Shahshahani's extensive teaching experience, this volume presents a thorough, rigorous course on the theory of differentiable manifolds. Geared toward advanced undergraduates and graduate students in mathematics, the treatment's prerequisites include a strong background in undergraduate mathematics, including multivariable calculus, linear algebra, elementary abstract algebra, and point set topology. More than 200 exercises offer students ample opportunity to gauge their skills and gain additional insights.
The four-part treatment begins with a single chapter devoted to the tensor algebra of linear spaces and their mappings. Part II brings in neighboring points to...

Multi-objective Route Planning in a Multi-modal Network with Alternative Paths

, M.Sc. Thesis Sharif University of Technology Tabrizian, Siavash (Author) ; Kourosh, Eshghi (Supervisor)

Abstract

In respect of increasing expanse public urban transport, road network complexity as well optimized route planning is necessary in transport network more than ever. Multi-modal network is a transport network which has various means of transportation modes. In that network the presentation a sequence transport mode is essential apart from determining the optimal route. Although choosing the shortest viable path has some limitation the user chooses that. In this paper a modal path planning in multi-modal network has been expressed which two objective functions in addition to minimize the number of change modes have been designed the first is cost and the second is time. Moreover, in this...

An Experimental Study of the Effects of Sweep Wing on the Boundary Layer of 2D Wing

, M.Sc. Thesis Sharif University of Technology Tabrizian, Arshia (Author) ; Soltani, Mohammad Reza (Supervisor) ; Davari, Ali Reza (Co-Advisor)

Abstract

The behavior of boundary layer under the effect of the sweep angle is considered. The measurements were performed by a pitot tube rake. Three models with various sweep angels at angles of attack -2, 0 and 2 degree were tested. Both tip and root of all wings were closed by flat plates in order to prevent the flow to roll-up. However the flow field on the wing was still three-dimensional because of the sweep angle. The velocity on the wing has two components; longitudinal and lateral. The cross flow emerges due to the non-equilibrium of pressure and centrifugal forces. The velocity profiles showed that the magnitude of cross flow was stronger near the leading edge of the wing. The cross flow...

Experimental investigation of a supercritical airfoil boundary layer in pitching motion

, Article Journal of Mechanical Science and Technology ; Volume 31, Issue 1 , 2017 , Pages 189-196 ; 1738494X (ISSN) Masdari, M ; Jahanmiri, M ; Soltani, M. R ; Tabrizian, A ; Gorji, M ; Sharif University of Technology

Korean Society of Mechanical Engineers 2017

Abstract

In this study, the boundary layer velocity profile on the upper surface of a supercritical airfoil in a forced sinusoidal pitching motion was measured and experimentally investigated. Measurements were performed using a boundary layer rake, including total pressure tubes positioned at 25 % of the chord far from the leading edge on the upper surface. For static measurements, the effects of the angle of attack between −3° and 14° and free-stream velocity between 40 m/s and 70 m/s were investigated; for dynamic measurements, the effects of oscillation amplitude variation between ±3° and ±10°, reduced frequency from 0.007 to 0.0313, and mean angle of attack between −3° and 6° were studied during...

Experimental and analytical model analysis of Babolsar's steel arch bridge

, Article 3rd International Conference on Bridge Maintenance, Safety and Management - Bridge Maintenance, Safety, Management, Life-Cycle Performance and Cost, Porto, 16 July 2006 through 19 July 2006 ; 2006 , Pages 235-237 ; 0415403154 (ISBN); 9780415403153 (ISBN) Beygi, M. H. A ; Kazemi, M. T ; Lark, B ; Tabrizian, Z ; Sharif University of Technology

Taylor and Francis/ Balkema 2006

Abstract

The paper presents the experimental and analytical model analysis of a steel-girder arch bridge. The field test is carried out by ambient vibration testing under traffic excitations. Both the peak picking method in the frequency domain and the stochastic subspace identification method in the time domain are used for the output-only model identification. A good agreement in identified frequencies has been found between the two methods. It is further demonstrated that the stochastic subspace method provides better mode shapes. The three-dimensional finite element models are constructed and an analytical model analysis is then performed to generate natural frequencies and mode shapes in the...

The Evolution of a Geometric Space in in the Nineteenth Century

, M.Sc. Thesis Sharif University of Technology Karimi, Ehsan (Author) ; Shahshahani, Siavash (Supervisor)

Abstract

The meaning and the nature of space and it’s essential properties seems to be one of the oldest problems which has been continuing to occupy human’s mind during centuries. It can be counted as a common ground between philosophy, mathematics, physics and even art. However this thesis concentrates on the philosophical and mathematical attitudes, neglecting the other aspects of the issue. Prima facie, it appears that the concept of space is essentially mingled with geometry, the science which seems to investigate the essentials of space. Taking it for granted, Kant regarded space, and so Euclidean geometry which dominates it, as an indispensible and necessary structure of the human’s mind....

P - Adic L Functions

, M.Sc. Thesis Sharif University of Technology Sanjari, Ali (Author) ; Shahshahani, Siavash (Supervisor)

Abstract

Using interpolation and starting with Bernoulli numbers, posed by Leopold and Kubota, the aspect of adic function was constructed as adic analogues of the Dirichlet functions.Studing Galois module theory of ideal class group and his favorite structure extensions and modules related to them,Iwasawa found a new method for constructing adic functions by using Stickelberger’s elements.These results wich established by Iwasawa are known as Iwasawa Theory and they have many application in Algebriac Number Theory. Iwasawa’s most remarkable disconvry is the facet that at least in some important cases, there is a similar deep algebraic and analytic dichotomy in arithmetic of extensions. A...

Exploiting structural information of data in active learning

, Article Artificial Intelligence and Soft Computing: Lecture Notes in Computer Science ; Volume 8468 LNAI, Issue PART 2 , 2014 , Pages 796-808 Shadloo, Maryam ; Beigy, Hamid ; Haghiri, Siavash ; Sharif University of Technology

2014

Abstract

In recent years, the active learning algorithms have focused on combining correlation criterion and uncertainty criterion for evaluating instances. Although these criteria might be useful, applying these measures on whole input space globally may lead to inefficient selected instances for active learning. The proposed method takes advantage of clustering to partition input space to subspaces. Then it exploits both labeled and unlabeled data locally for selection of instances by using a graph-based active learning. We define a novel utility score for selecting clusters by combining uncertainty criterion, local entropy of clusters and the factor of contribution of each cluster in queries....

A Trusted Design Platform for Trojan Detection in FPGA Bitstreams Using Partial Reconfiguration

, M.Sc. Thesis Sharif University of Technology Shekofteh, Nastaran (Author) ; Bayat-Sarmadi, Siavash (Supervisor)

Abstract

Hardware Trojans have emerged as a major concern for integrated circuits in recent years. As a result, detecting Trojans has become an important issue in critical applications, such as finance and health. In this work, a trusted platform for detecting Trojans in FPGA bitstreams is presented. The proposed methodology takes advantage of increased Trojan activation, caused by transition aware partitioning of the circuit, while it benefits partial reconfiguration feature of FPGAs to reduce area overhead. Simulation results, performed for the transition probability thresholds of 〖10〗^(-4) and 〖2×10〗^(-5), show that this method increases the ratio of the number of transitions in the Trojan...

Performance Evaluation of Physical Unclonable Functions and Proposing a Scheme on FPGA

, M.Sc. Thesis Sharif University of Technology Ramezani, Alireza (Author) ; Bayat-Sarmadi, Siavash (Supervisor)

Abstract

In recent years, in addition to traditional cryptographic blocks, a hardware blocks in this work namely PUF, has been used mostly for chip ID generation, authentication and so on. In this work we study recent proposed PUFs and their implementations on FPGA, and the measurement of quality metrics on them. Some of most important characteristics of PUFs are unpredictability, reliability, number of challenge response pairs and area. According to experiments that have been performed in this study and also according to previous work, one high-quality PUF in term of uniqueness and reliability is Ring Oscillator PUF. However, the disadvantage of this PUF is small number of challenge and response...

Increasing BIOS Trust in Personal Computers Using Reconfigurable Devices

, M.Sc. Thesis Sharif University of Technology Eslampanah, Marziye (Author) ; Bayat Sarmadi, Siavash (Supervisor)

Abstract

Due to the expansion of digital system threats, trusted computation with a new approach for countering such threats has emerged. This approach is based on using a hardware module for implementing a trusted platform (TPM). TPM includes a chipset and the trusted systems core. Nowadays many of mobile computers do include this technology. This hardware creates trust using a trust chain and expanding this trust to other parts of the system. The starting point in this chain is the computer BIOS. BIOS is the first code that the system usually executes. One of the most powerful recent attacks on computer systems is to infect the BIOS and other firmware. One of such complicated attacks is the rootkit...

Efficient Implementation of Post-Quantum Cryptography Based on Learning with Errors

, Ph.D. Dissertation Sharif University of Technology Ebrahimi, Shahriar (Author) ; Bayat Sarmadi, Siavash (Supervisor)

Abstract

Public key encryption (PKE) cryptography plays a big role in securing communication channels of internet. The security of every PKE scheme is usually based on a hard problem that has no polynomial time solution using any computational structure. However, widely used classic PKE schemes such as RSA or ECC, are based on hard problems that have polynomial solutions using a quantum computer. Therefore, such PKE schemes will not be secure in post-quantum era. Among quantum-resistant schemes, lattice-based cryptography and especially learning with errors (LWE) problem have gained high attention due to their low computational complexity. In this thesis, different LWE-based cryptosystems are...

Hardware Acceleration of Convolutional Neural Networks by Computational Prediction

, M.Sc. Thesis Sharif University of Technology Sajjadi, Pegahsadat (Author) ; Bayatsarmadi, Siavash (Supervisor)

Abstract

Recently, Convolutional neural networks (CNNs) are widely used in many artificial intelligence applications such as image processing, speech processing and robotics. The neural networks superior accuracy comes at the cost of high computational complexity. Recent studies show that these operations can be performed in parallel. Therefore, as graphic processing units (GPUs) offer the best performance in terms of computational power and throughput, they are widely used to implement and accelerate neural networks. Nevertheless, the high price and power consumption of these processors have resulted in drawing more attraction towards Field-Programmable Arrays (FPGAs). In order to improve resource...

Implementation of an IoT Edge Computing Module in Compliance with TPM Standards

, M.Sc. Thesis Sharif University of Technology Hasanizadeh, Parisa (Author) ; Bayat Sarmadi, Siavash (Supervisor)

Abstract

Cloud computing has a significant role in expanding applications of the Internet of Things (IoT). Currently, applications such as virtual reality and augmented reality require low latency, which is not achievable using traditional cloud computing in some scenarios. Edge computing is a new approach in IoT, which solves some of the limitations of the cloud computing by extending and developing its operations. Reducing response time and network traffic are some of the most important achievements of edge computing. Despite of its numerous advantages over cloud computing, edge computing faces serious challenges such as virtualization, implementation infrastructure, resource allocation and task...

Improving Remote Attestation Techniques for IoT Devices using Physical Model

, M.Sc. Thesis Sharif University of Technology Salehi, Mohsen (Author) ; Bayat Sarmadi, Siavash (Supervisor)

Abstract

Due to the widespread growth in the use of IoT devices, authors consider these devices as an attractive target platform. Several approaches have been proposed to defend IoT devices against various attacks. However, most of them suffer from some shortcomings such as being computationally expensive, not being general, or not being robust enough.Due to the attacks such as firmware modification and the existence of computational limitations, the use of local approaches is inefficient. Another approach is to use remote attestation techniques, which are divided into two categories, static and dynamic. However, static detection techniques are vulnerable to runtime attacks. Furthermore, existing...

Customizing a Privacy-Preserving Blockchain-Based Distributed Ledger for Second-Price Auction Smart Contract

, M.Sc. Thesis Sharif University of Technology Mirzaei, Amir (Author) ; Bayat Sarmadi, Siavash (Supervisor)

Abstract

A distributed ledger is a method of digital data storage and sharing in different places, and the blockchain technology is a way of implementing a distributed ledger. This technology has been employed in many of the cryptocurrencies like Ethereum to store transactions. In addition to storing transactions, Ethereum deploys scripts called smart contracts that are automatically executable. These scripts execute transparently and without preserving the privacy of participants. On the other hand, confidentiality and privacy are among the important components in data, network, and system security. Models such as Hawk and Enigma have been presented to obtain privacy-preserving in smart contracts;...

Network Traffic Reduction in Internet of Things Using Reconfigurable Cache based on Workload Characterization

, M.Sc. Thesis Sharif University of Technology Rezaei, Rezvan (Author) ; Bayat Sarmadi, Siavash (Supervisor)

Abstract

Nowadays, with the advancement of internet of things, The number of nodes within the network has increased and there is huge traffic in these networks despite the small volume of data sent and received each node. The current architecture of the Internet network does not have the functionality required for Internet of things, as a result of designing a new architecture for Internet - based Internet of things. Content - based network is a new architecture introduced to the Internet, and its purpose is to change the network from host-centric to content-centric. One of the features of content-based networks is the use of in network caching that helps increase productivity and reduce the traffic...

High Speed Implementation of Finite Field Multiplier Suitable for Isogeny-Based Protocols

, M.Sc. Thesis Sharif University of Technology Alivand, Armin (Author) ; Bayat Sarmadi, Siavash (Supervisor)

Abstract

Classic public key cryptographic systems are based on difficult mathematical problems that will lose their security with the advent of high-speed quantum computers. Isogeny-based cryptography is one of the five main methods in post-quantum cryptography, the hard problem of which is finding large-degree isogenies between elliptic curves. The most important advantage of isogeny-based protocols is the shorter public key length and the main problem is their low speed and low performance compared to other cryptographic systems. Due to the fact that these protocols are implemented on a finite field using basic operations, such as multiplication, squaring, addition, and subtraction, improving the...

Enhancing A RISC-V Based Processor to Support Lattice-based Post-uantum Cryptography

, M.Sc. Thesis Sharif University of Technology Hadayeghparast, Shahriar (Author) ; Bayat Sarmadi, Siavash (Supervisor)

Abstract

The amount of data over networks are increasing rapidly, and accordingly, smart devices are being encountered severe challenges by the advancement of security threats. In order to create safe communications among smart devices, employing public-key cryptography is needed. But, public-key and classic cryptography, such as RSA, have high computation complexities and are not resistant to quantum attacks. Due to mentioned reasons, using these types of cryptography algorithms in internet-of-things (IoT) devices is unreasonable. In the past decade, lattice-based cryptography has been one of the pioneer post-quantum cryptography members, which benefits from comparatively lower computational...

GPU-based Acceleration of Isogeny-based Cryptography

, M.Sc. Thesis Sharif University of Technology Gheibi, Mir Erfan (Author) ; Bayat Sarmadi, Siavash (Supervisor)

Abstract

Post-quantum cryptography, as one of the newest groups of cryptographic algorithms, is thought to be secure against most sophisticated attacks by the groundbreaking quantum computers. Isogeny-based cryptography is an appealing contender among them due to its exceptional characteristics, especially the shortest public key in key encapsulation, encryption and decryption amid the other nominees of NIST post-quantum standard. However, its high computational complexity is a significant drawback. This research aims to increase the performance of isogeny-based cryptography in the most compute-intensive part, both in throughput and latency perspectives on GPUs and CPUs, which are the most widespread...