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An Alert Correlation System with the Throughput of Multi-Thousands Events per Second
, M.Sc. Thesis Sharif University of Technology ; Jalili, Rasoul (Supervisor)
Abstract
With the growing deployment of host and network intrusion detection systems, analyzing generated alerts from these systems becomes critically important and challenging due to its complexity and high amount of data. Alert Correlation systems are a possible solution for deep analysis of incoming alerts in response to potential attacks against enterprise networks. Although several known alert correlation systems have been proposed for this purpose so far, most of them do not support high amount of input due to their centralized architecture. In this thesis, we propose a system architecture and approach for alert correlation to be extensible, flexible, and modular. The architecture encompasses...
Performance evaluation of shared hosting security methods
, Article Proc. of the 11th IEEE Int. Conference on Trust, Security and Privacy in Computing and Communications, TrustCom-2012 - 11th IEEE Int. Conference on Ubiquitous Computing and Communications ; 2012 , Pages 1310-1315 ; 9780769547459 (ISBN) ; Arshad, S ; Khoshkdahan, S ; Sharif University of Technology
2012
Abstract
Shared hosting is a kind of web hosting in which multiple websites reside on one webserver. It is cost-effective and makes the administration easier for websites' owners. However, shared hosting has some performance and security issues. In default shared hosting configuration, all websites' scripts are executed under the webserver's user account regardless of their owners. Therefore, a website is able to access other websites' resources. This security problem arises from lack of proper isolation between different websites hosted on the same webserver. In this survey, we have examined different methods for handling mentioned security issue. Also we evaluated the performance of mentioned...
Two novel server-side attacks against log file in Shared Web Hosting servers
, Article 2012 International Conference for Internet Technology and Secured Transactions, ICITST 2012 ; 2012 , Pages 318-323 ; 9781908320087 (ISBN) ; Arshad, S ; Khoshkdahan, S ; Jalili, R ; Sharif University of Technology
2012
Abstract
Shared Web Hosting service enables hosting multitude of websites on a single powerful server. It is a well-known solution as many people share the overall cost of server maintenance and also, website owners do not need to deal with administration issues is not necessary for website owners. In this paper, we illustrate how shared web hosting service works and demonstrate the security weaknesses rise due to the lack of proper isolation between different websites, hosted on the same server. We exhibit two new server-side attacks against the log file whose objectives are revealing information of other hosted websites which are considered to be private and arranging other complex attacks. In the...
A comprehensive approach to abusing locality in shared web hosting servers
, Article Proceedings - 12th IEEE International Conference on Trust, Security and Privacy in Computing and Communications, TrustCom 2013, Melbourne, VIC; Australia ; July , 2013 , Pages 1620-1625 ; 9780769550220 (ISBN) ; Arshad, S ; Khoshkdahan, S ; Jalili, R ; Sharif University of Technology
2013
Abstract
With the growing of network technology along with the need of human for social interaction, using websites nowadays becomes critically important which leads in the increasing number of websites and servers. One popular solution for managing these large numbers of websites is using shared web hosting servers in order to decrease the overall cost of server maintenance. Despite affordability, this solution is insecure and risky according to high amount of reported defaces and attacks during recent years. In this paper, we introduce top ten most common attacks in shared web hosting servers which can occur because of the nature and bad configuration in these servers. Moreover, we present several...
Technical English for mechanical engineers
, Book ; Meghdari,Ali
Sharif University Press
2014
Abstract
Local educational institutions produce in-house English for Specific Purpose (ESP) materials according to the curriculum policies designated and developed by the Ministry of Higher Education In Iran. To this end, this book aims to be used in the Iranian setting at the tertiary level for undergraduate students majoring in Mechanical Engineering. Moreover, the style of English usage in this ESP textbook is American.
Regarding the content of the textbook, it has both thematic organizations in which the topics are relevant and includes sufficient treatment of the target language areas necessary for the students. The principle organizing approach of this textbook is theme-based. In addition,...
Regarding the content of the textbook, it has both thematic organizations in which the topics are relevant and includes sufficient treatment of the target language areas necessary for the students. The principle organizing approach of this textbook is theme-based. In addition,...
Feedback control of the neuro-musculoskeletal system in a forward dynamics simulation of stair locomotion [electronic resource]
, Article Proc. of IMechE Part H: Journal of Engineering in Medicine ; 2009, Vol. 223, No. 6, pp. 663-675 Journal of NeuroEngineering and Rehabilitation ; Volume 11, Issue 1, 30 April 2014, Article number 78 ; Meghdari, Ali ; Vossough, Gholam Reza ; Sharif University of Technology
Abstract
The aim of this study is to employ feedback control loops to provide a stable forward dynamics simulation of human movement under repeated position constraint conditions in the environment, particularly during stair climbing. A ten-degrees-of-freedom skeletal model containing 18 Hill-type musculotendon actuators per leg was employed to simulate the model in the sagittal plane. The postural tracking and obstacle avoidance were provided by the proportional—integral—derivative controller according to the modulation of the time rate change of the joint kinematics. The stability of the model was maintained by controlling the velocity of the body's centre of mass according to the desired centre of...
Design and Construction of a Soft Actuated Exoskeleton for Hand Rehabilitation of Stroke Patients
, M.Sc. Thesis Sharif University of Technology ; Ghafari, Ali (Supervisor) ; Meghdari, Ali (Supervisor)
Abstract
The main goal of this thesis is the design and development of a rehabilitation device for helping patients “to improve blood circulation” & retain and recover their abilities if possible that were lost during the stroke or a accident like that (my research in karaj/iran shows that it is possible by just movement of the specific body part). The focus is on hand in this thesis because Injuries to the hand are common and can be very debilitating since our hands are our primary means for interacting with our world. For rehabilitation in case of human hand there are several practices that should be done for patients either in home or in a rehabilitation center, time and money that is supposed to...
Silica chloride/wet SiO2 as a novel heterogeneous system for the deprotection of acetals under mild conditions [electronic resource]
, Article Phosphorus, Sulfur, and Silicon and the Related Elements ; Volume 178:2667-2670, Issue 12, 2003 ; Pourjavadi, Ali ; Zolfigol, Mohammad Ali ; Bamoniri, Abdolhamid
Abstract
A combination of silica chloride and wet SiO2 was used as an effective deacetalizating agent for the conversion of acetals to their corresponding carbonyl derivatives under mild and heterogeneous condition
Earthquake Branch
, M.Sc. Thesis Sharif University of Technology ; Bakhshi, Ali (Supervisor)
Abstract
In the past few decades, shaking tables are widely used to evaluate system response of structures under seismic excitations. These devices are used without any fundamental research performed on a shaking table system as an entity model. In most of these studies for simplicity, it is assumed that there exist no considerable vibration and displacement around the shaking tables, and no attention is paid to the peripheral substances such as soil settled under the foundation.
In this thesis, result of ambient vibration test on shaking table system (solid deck, concrete foundation and soil layer) has been presented. Precise sensors known as low frequency and high accuracy accelerometers have...
In this thesis, result of ambient vibration test on shaking table system (solid deck, concrete foundation and soil layer) has been presented. Precise sensors known as low frequency and high accuracy accelerometers have...
Comparison between Performance of Stone Columns and RAPs from the Bearing Capacity and Settlement Reduction Viewpoints
, M.Sc. Thesis Sharif University of Technology ; Pak, Ali (Supervisor)
Abstract
Out of several ground improvement techniques available, stone columns have been widely used. This technique has been successfully applied to increase the bearing capacity and to reduce the settlement for foundation of structures like liquid storage tanks, earthen embankments, raft foundations, etc., where a relatively large settlement is permissible. This technique has, generally, been proven successful in increasing the stiffness of weak soils, upgrading their safe bearing capacity, and reducing their total and differential settlements, as well as speeding up their consolidation process. The beneficial effects of stone column installation in weak deposits is manifested in the form of...
Improvement of Stability of Haptic Force Interaction with Virtual Environments Using a Haptic Interface with a Separate Tracker
, M.Sc. Thesis Sharif University of Technology ; Meghdari, Ali (Supervisor) ; Nahvi, Ali (Supervisor)
Abstract
In the present study, a new version of haptic devices is presented in which user’s hand is in contact with the device just while collision with virtual surface. In this system, the position of user’s finger can be traced by using a camera and the haptic device follows user’s finger at the distance of about two centimeters. While the haptic device approaches to the virtual surface, gradually reduces its speed and stops about two centimeters distant of virtual plane. Then user’s hand collides with the haptic device which is static. Greater fidelity, transparency, more stability and also no need to large actuators are of the advantages of this system. In this project, first we present a new...
Characterzing Variation of Small Strain Shear Modulus of Unsaturated Sand During Hydraulic Hysteresis with Bender Elements
, M.Sc. Thesis Sharif University of Technology ; Pak, Ali (Supervisor) ; Khosravi, Ali (Supervisor)
Abstract
Results of previous studies on silt and clay indicated that variations in the small strain shear modulus, Gmax, during drying had a non-linear increasing trend with matric suction with greater values upon wetting. However, due to different material properties and inter-particle forces, different behaviour in Gmax is expected for sand. Although considerable research has been devoted in recent years to characterize the behaviour of Gmax of sand during drying, rather less attention has been paid to the effect of hydraulic hysteresis on Gmax and its variations during wetting. In the study presented herein, an effort was made to characterize the variation of Gmax for specimens of sand during...
Simulation of the Biomolecule Imaging and Manipulation Via AFM by Molecular Dynamics Method
, M.Sc. Thesis Sharif University of Technology ; Meghdari, Ali (Supervisor) ; Moosavi, Ali (Supervisor)
Abstract
In this thesis we try to find optimized parameters for imaging and manipulation of a biosample with AFM. For this we have prepared a numerous Molecular Dynamics simulation and find some reliable result. So, first we have focused on imaging process in Non contact mode (the less harmful mode). Then we headed into the manipulation process. The main problem about manipulating a biosample is the environment. In imaging section, the process of imaging a biomolecule by AFM is modeled using molecular dynamics simulations. Since the large normal force exerted by the tip on the biosample in contact and tapping modes may damage the sample structure and produce irreversible deformation, the non-contact...
Sequential Competitive Facility Location In Continuous Geometric Space
, M.Sc. Thesis Sharif University of Technology ; Abam, Mohammad Ali (Supervisor)
Abstract
Abstract The problem of competetive facility location can be defined as follows: There are a number of customers in the form of points in space, and two players arrange a number of facilities in the form of points in space, given some limitations, respectively. Each customer’s connection to each facility has a cost for the customer and an advantage for the facility, and each customer wants to be connected to at most one of the facilities which has the lowest cost for him. The goal is to find the strategy of placing the facilities and determining the cost which the facility receives from the customer, in such a way that the player’s profit is maximised.In this thesis, we first sought to...
Distributed Verifiable Computing: Algorithms and Analysis
, M.Sc. Thesis Sharif University of Technology ; Maddah Ali, Mohammad Ali (Supervisor)
Abstract
Zero knowledge proofs allow a person (prover) to convince another person (verifier) that he has performed a specific computation on a secret data correctly, and has obtained a true answer, without having to disclose the secret data. QAP (Quadratic Arithmetic Program) based zkSNARKs (zero knowledge Succinct Non-interactive Argument of Knowledge) are a type of zero knowledge proof. They have several properties that make them attractive in practice, e.g. verifier's work is very easy. So they are used in many areas such as Blockchain and cloud computing. But yet prover's work in QAP based zkSNARKs is heavy, therefore, it may not be possible for a prover with limited processing resource to run...
Performance of Partially Filled Mini-Channels with Porous Media
, M.Sc. Thesis Sharif University of Technology ; Nouri, Ali (Supervisor) ; Moosavi, Ali (Co-Advisor)
Abstract
Laminar forced convection flow through a channel partially filled with a porous material was numerically studied in this thesis. The Navier-Stokes and Brinkman-Forchheimer equations were used to model the fluid flow in the free and porous regions, respectively. Coupling of the pressure and velocity fields was resolved using the SIMPLEC algorithm. The local thermal equilibrium was adopted in the energy equation. The effects of the thermal conductivity ratio, Darcy number, porosity, Reynolds number and height of the porous insert on velocity and temperature field were investigated. The results show that the flow behavior and its associated heat transfer are susceptible to the variation of the...
Selective preparation of fluorescent 1,8-naphthalimides using acidic alumina under microwave irradiation [electronic resource]
, Article Journal of Chemical Research ; 01/2001; 2001(11):485-487 ; Bagheri Marandi, Gholam
Abstract
7H-benzimidazo[2,1-a]benz[de]isoquinolin-7-one compounds were prepared in a selective manner by reaction between o-phenylenediamines and appropriate 1,8-naphthalenedicarboxylic anhydrides using acidic alumina under microwave irradiation
Selective synthesis of conjugated enynes from α-arylalkynols using LiCl-Acidic Al2O3 under solvent-free conditions [electronic resource]
, Article Journal of Chemical Research ; Volume 2002, Number 8, 1 August 2002, pp. 378-380(3) ; Bagheri Marandi, Gholam
Abstract
Free Content Selective synthesis of conjugated enynes from α-arylalkynols using LiCl-Acidic Al2O3 under solvent-free conditions
Cracked Rotors Modeling for Vibration Analysis and Control
, Ph.D. Dissertation Sharif University of Technology ; Behzad , Mehdi (Supervisor) ; Meghdari, Ali (Supervisor)
Abstract
The main aim of this thesis is to develop a mathematical model for vibration analysis of cracked rotors. This model should be a simple and precise model for prediction of the cracked rotor vibration behavior and suitable for vibration control. In order to create such model, the pure bending of a cracked beam is analyzed at first. This analysis is performed for two different orientations of the crack with respect to the beam and the bending vector. In this section a continuous bending model with continuous model for crack is developed which can predict the full deformation of the cracked beam in bending and can estimate the stress distribution in the beam with good approximation. Comparison...
Coded Computing for Distributed Machine Learning
, Ph.D. Dissertation Sharif University of Technology ; Maddah Ali, Mohammad Ali (Supervisor)
Abstract
Nowadays, we are forced to use distributed computing due to the growth of data, the challenge of storing and processing it, as well as the emergence of new problems in machine learning and the complexity of the models. In distributed computing, the computation is per- formed by a distributed system consisting of several worker nodes such that, the main task is divided into several smaller tasks and assigned to each worker node. Then, different worker nodes will cooperate to accomplish the main task. Although distributed systems are efficient in solving problems and dealing with the mentioned challenges, they are vulnerable to the presence of stragglers, adversarial worker nodes, high...