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Vulnerability take grant (VTG): an efficient approach to analyze network vulnerabilities
, Article Computers and Security ; Volume 26, Issue 5 , 2007 , Pages 349-360 ; 01674048 (ISSN) ; Jalili, R ; Sharif University of Technology
2007
Abstract
Modeling and analyzing information system vulnerabilities help predict possible attacks to computer networks using vulnerabilities information and the network configuration. In this paper, we propose a comprehensive approach to analyze network vulnerabilities in order to answer the safety problem focusing on vulnerabilities. The approach which is called Vulnerability Take Grant (VTG) is a graph-based model consists of subject/objects as nodes and rights/relations as edges to represent the system protection state. Each node may have properties including single vulnerabilities such as buffer overflow. We use the new concept of vulnerability rewriting rule to specify the requirements and...
Using CSP to model and analyze transmission control protocol vulnerabilities within the broadcast network
, Article Proceedings - 2004 International Networking and Communication Conference, INCC 2004, Lahore, 11 June 2004 through 13 June 2004 ; 2004 , Pages 42-47 ; 0780383257 (ISBN) ; Jalili, R ; Sharif University of Technology
2004
Abstract
Spreading networks and increasing their complexity has complicated the task of security analysis. Accordingly, automatic verification approaches have received more attention recently. In this paper, we modeled a network including a set of hosts (clients and servers) using the process algebra CSP in order to verify the Transmission Control Protocol (TCP) behavior against an active intruder. The model is verified using the FDR tool and as a result, some attack scenarios violating the security are found. The scenarios showes how an intruder can compromise the server trust to its clients. As the model is modular, extendable, and scalable, more complex attack scenarios (combination of simple...
Modeling of network security-related behaviours using NVML
, Article 8th International Multitopic Conference, INMIC 2004, 24 December 2004 through 26 December 2004 ; 2004 , Pages 506-511 ; 0780386809 (ISBN); 9780780386808 (ISBN) ; Jalili, R ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2004
Abstract
Nowadays, security has become an important issue for organizations especially in e-commerce applications. The spreading of networks and increasing of their complexity has complicated the task of security analysis, therefore automatic approaches have received more attention recently. This paper proposes a model-based approach to analyze the overall security of a network, based on the interaction of hosts within the network. A simple language is introduced far modeling securityrelated behaviours of networks and systems. Using the language, a case study is described and its formal model and security properties are presented. © 2004 IEEE
RT-UNNID: A practical solution to real-time network-based intrusion detection using unsupervised neural networks
, Article Computers and Security ; Volume 25, Issue 6 , 2006 , Pages 459-468 ; 01674048 (ISSN) ; Jalili, R ; Shahriari, H. R ; Sharif University of Technology
2006
Abstract
With the growing rate of network attacks, intelligent methods for detecting new attacks have attracted increasing interest. The RT-UNNID system, introduced in this paper, is one such system, capable of intelligent real-time intrusion detection using unsupervised neural networks. Unsupervised neural nets can improve their analysis of new data over time without retraining. In previous work, we evaluated Adaptive Resonance Theory (ART) and Self-Organizing Map (SOM) neural networks using offline data. In this paper, we present a real-time solution using unsupervised neural nets to detect known and new attacks in network traffic. We evaluated our approach using 27 types of attack, and observed...
Using description logics for network vulnerability analysis
, Article International Conference on Networking, International Conference on Systems and International Conference on Mobile Communications and Learning Technologies, ICN/ICONS/MCL'06, Morne, 23 April 2006 through 29 April 2006 ; Volume 2006 , 2006 ; 0769525520 (ISBN); 9780769525525 (ISBN) ; Jalili, R ; Abolhassani, H ; Shahriari, H. R ; Sharif University of Technology
2006
Abstract
The distributed nature and complexity of computer networks and various services provided via them, makes the networks vulnerable to numerous attacks. The TCP/IP presumptions which are based on using this protocol to provide a simple, open communication infrastructure in an academic and collaborative environment, causes this protocol lack of built-in mechanisms for authentication, integrity and privacy. Even though in the last few years a more systematic approach to TCP/IP network security problem has been followed, a formal approach to this problem is lacking. In this paper, we propose using Description Logics as a formal model which could be used to analyze TCP/IP networks against attacks....
Network vulnerability analysis through vulnerability take-grant model (VTG)
, Article 7th International Conference on Information and Communications Security, ICICS 2005, Beijing, 10 December 2005 through 13 December 2005 ; Volume 3783 LNCS , 2005 , Pages 256-268 ; 03029743 (ISSN); 3540309349 (ISBN); 9783540309345 (ISBN) ; Sadoddin, R ; Jalili, R ; Zakeri, R ; Omidian, A. R ; Sharif University of Technology
2005
Abstract
Modeling and analysis of information system vulnerabilities helps us to predict possible attacks to networks using the network configuration and vulnerabilities information. As a fact, exploiting most of vulnerabilities result in access rights alteration. In this paper, we propose a new vulnerability analysis method based on the Take-Grant protection model. We extend the initial Take-Grant model to address the notion of vulnerabilities and introduce the vulnerabilities rewriting rules to specify how the protection state of the system can be changed by exploiting vulnerabilities. Our analysis is based on a bounded polynomial algorithm, which generates the closure of the Take-Grant graph...
Topological analysis of multi-phase attacks using expert systems
, Article Journal of Information Science and Engineering ; Volume 24, Issue 3 , 2008 , Pages 743-767 ; 10162364 (ISSN) ; Ganjisaffar, Y ; Jalili, R ; Habibi, J ; Sharif University of Technology
2008
Abstract
With the increasing number and complexity of network attacks, the demand for automatic vulnerability analysis tools has increased. The prerequisite of making these tools is to have a formal and precise model of network configurations and vulnerabilities. Utilizing this model, network administrators can analyze the effects of vulnerabilities on the network and complex attack scenarios can be detected before happening. In this paper, we present a general logic-based framework for modeling network configurations and topologies. Then, a number of important and wide-spread network vulnerabilities are modeled as general inference rules based on the framework definitions. We implemented the...
Tribological characterization of electroless Ni-10% P coatings at elevated test temperature under dry conditions
, Article International Journal of Advanced Manufacturing Technology ; Volume 62, Issue 9-12 , October , 2012 , Pages 1063-1070 ; 02683768 (ISSN) ; Ghasemi, H. R ; Ziaei, A. A ; Shahriari, D ; Sharif University of Technology
Springer
2012
Abstract
An experimental study of wear characteristics of electroless Ni-10% P coating sliding against hard AISI 52100 steel pin is investigated. Experiments are carried out at room and 550°C temperatures. Heat treatment effects on tribological behavior of this coating are studied. The wear surface and the microstructure of the coatings are analyzed using optical microscopy, scanning electron microscopy, energy dispersion analysis X-ray, and microhardness testing equipment. It is observed that the forming of continuous oxide film on contacting surfaces of pin and disk improves wear resistance and decreases friction coefficient of the Ni-10% P coating. The results indicate that the wear resistance of...
Detection of distributed denial of service attacks using statistical pre-processor and unsupervised neural networks
, Article First International Conference on Information Security, Practice and Experience, ISPEC 2005, 11 April 2005 through 14 April 2005 ; Volume 3439 , 2005 , Pages 192-203 ; 03029743 (ISSN) ; Imani Mehr, F ; Amini, M ; Shahriari, H. R ; Sharif University of Technology
Springer Verlag
2005
Abstract
Although the prevention of Distributed Denial of Service (DDoS) attacks is not possible, detection of such attacks plays main role in preventing their progress. In the flooding attacks, especially new sophisticated DDoS, the attacker floods the network traffic toward the target computer by sending pseudo-normal packets. Therefore, multi-purpose IDSs do not offer a good performance (and accuracy) in detecting such kinds of attacks. In this paper, a novel method for detection of DDoS attacks has been introduced based on a statistical pre-processor and an unsupervised artificial neural net. In addition, SPUNNID system has been designed based on the proposed method. The statistical...
Vulnerability analysis of networks to detect multiphase attacks using the actor-based language Rebeca
, Article Computers and Electrical Engineering ; Volume 36, Issue 5 , 2010 , Pages 874-885 ; 00457906 (ISSN) ; Makarem, M. S ; Sirjani, M ; Jalili, R ; Movaghar, A ; Sharif University of Technology
2010
Abstract
Increasing use of networks and their complexity make the task of security analysis more and more complicated. Accordingly, automatic verification approaches have received more attention recently. In this paper, we investigate applying of an actor-based language based on reactive objects for analyzing a network environment communicating via Transport Protocol Layer (TCP). The formal foundation of the language and available tools for model checking provide us with formal verification support. Having the model of a typical network including client and server, we show how an attacker may combine simple attacks to construct a complex multiphase attack. We use Rebeca language to model the network...
An integrated approach for enhancing the quality of the product by combining robust design and customer requirements
, Article Quality and Reliability Engineering International ; Vol. 30, Issue. 8 , 2014 , pp. 1285-1292 ; ISSN: 07488017 ; Haji, M. J ; Eslamipoor, R ; Sharif University of Technology
2014
Abstract
Enhancing the quality of the product has always been one considerable concern of production process management, and this subject gave way to implementing so many methods including robust design. In this paper, robust design utilizes response surface methodology (RSM) considering the mean and variance of the response variable regarding system design, parameter design, and tolerance design. In this paper, customer requirements and robust design are regarded simultaneously to achieve enriched quality. Subsequently, with a non-linear programming, a novel method for integrating RSM and quality function deployment has been proposed to achieve robustness in design. The customer requirements are...
γ' Precipitate dissolution during heat treatment of nimonic 115 superalloy
, Article Materials and Manufacturing Processes ; Volume 24, Issue 5 , 2009 , Pages 559-563 ; 10426914 (ISSN) ; Sadeghi, M. H ; Akbarzadeh, A ; Sharif University of Technology
2009
Abstract
In precipitation hardenable materials, it is desirable to determine the precipitate dissolution temperature for homogenizing the microstructure by controlling the size and distribution of the precipitates. In this research, differential thermal analysis, dilatometry technique, heat treatments followed by microstructure evaluation were used to determine the -γ' dissolution temperature of Nimonic 115. It is assumed that the variation of enthalpy is governed by the changes in y volume fraction and γ concentration with time and temperature, and any contribution of the coarsening of γ' is neglected. The values obtained for the solvus temperature of γ precipitates by the three methods are all in...
The influence of heat treatment and hot deformation conditions on γ′ precipitate dissolution of Nimonic 115 superalloy
, Article International Journal of Advanced Manufacturing Technology ; Volume 45, Issue 9-10 , 2009 , Pages 841-850 ; 02683768 (ISSN) ; Sadeghi, M. H ; Akbarzadeh, A ; Cheraghzadeh, M ; Sharif University of Technology
2009
Abstract
In precipitation hardenable materials, it is desirable to determine the precipitate dissolution temperature for homogenizing the microstructure by controlling the size and distribution of the precipitates. In this research, the influence of various heat treatment and hot deformation conditions on the kinetics of γ ′ dissolution and its morphological evolution in Nimonic 115 was studied. In addition, hot deformation behavior of the material was investigated using hot compression experiments at varying temperature (between 1,050°C and 1,175°C) and strain rates (between 0.01 and 1 s-1) up to a true strain of 0.8. The values obtained for the solvus temperature of γ ′ precipitates by two methods...
The application of proportional hazards and frailty models to multistage processes surveillance
, Article International Journal of Advanced Manufacturing Technology ; Volume 74, Issue 1-4 , September , 2014 , Pages 461-470 ; ISSN: 02683768 ; Aghaie, A ; Shahriari, H ; Niaki, S. T. A ; Sharif University of Technology
2014
Abstract
Monitoring industrial and service processes with the purpose of improving the product reliability has been largely addressed in the literature. The surveillance procedures have been proposed with the concentration on single-stage processes with independent quality characteristics. However, the cascade property in multistage processes entails specific monitoring methods which take into account the dependency structure among quality variables in successive stages of a process. This is referred to as regression-adjustment that justifies the heterogeneity in the study population and thus leads to optimal monitoring of multistage processes. In general, it is not straightforward to adjust a...
Improving reliability in multistage processes with autocorrelated observations
, Article Quality Technology and Quantitative Management ; Volume 12, Issue 2 , 2015 , Pages 143-157 ; 16843703 (ISSN) ; Aghaie, A ; Shahriari, H ; Akhavan Niaki, S. T ; Sharif University of Technology
2015
Abstract
Multistage process surveillance is considered to effectively improve the product reliability in manufacturing or service operations. To this end, the process output is commonly inspected under specific conditions and the values of the reliability-related quality characteristic are measured. However, in some cases, the observations from the process output are autocorrelated. This brings about the situation where the use of existing monitoring schemes is futile. Therefore, a class of survival analysis regression models called the proportional hazards (PH) model has been modified to justify the effect of cascade property in line with the autocorrelation issue. Subsequently, three monitoring...
Vorticity-Bases Adaptive Mesh Refinement for Upscaling of Highly Heterogeneous Porous Media
, M.Sc. Thesis Sharif University of Technology ; Firoozabadi, Bahar (Supervisor)
Abstract
The results of numerical simulation of underground flows are greatly affected not only by the discretization method of flow equations, but also by the way that the geological domain is upscaled. Including the detailed knowledge of heterogeneous permeability distribution is mostly neither feasible nor computationally efficient. So it is important to develop efficient grid generation and upscaling methods to simplify the fine-scale flow model while still including the impact of the heterogeneities as far as possible. Thus regions where parameters of interest have larger values or higher changes require finer grid blocks and regions with lower values or minor changes should have coarser grid...
Analytical modeling of a Minimally Invasive Surgery grasper actuated by shape memory alloy wires
, Article International Conference on Robotics and Mechatronics, ICRoM 2013 ; Feb , 2013 , Pages 147-151 ; 9781467358118 (ISBN) ; Zabihollah, A ; Sharif University of Technology
2013
Abstract
Minimally Invasive Surgery (MIS) is getting common these days. MIS robots using special tools can perform surgery precisely as humans. This is only possible with dexterous end-effectors and a well-controlled system. Local, lightweight and powerful actuators positioned at end-effectors provide the ability to decrease the degrees of freedom and simplify the design. This paper discusses a grasper design actuated by Shape Memory Alloy (SMA) wires that can be used in MIS robotics. The properties of a commercially available shape memory alloy are explored and analytical formulations for the actuation procedure are developed. The grasper actuated by SMA wires is studied and the procedure of...
Consequence Modelling of Ethylene Oxide Reactor of Morvarid Petrochemical Co
, M.Sc. Thesis Sharif University of Technology ; Rashtchian, Davood (Supervisor)
Abstract
As Ethylene Oxide is a highly toxic, flammable, and hazardous material, the consequences of any malfunction in an Ethylene Oxide reactor may be irreparable. The aim of this thesis is to evaluate the probable consequences of an accident in Morvarid Petrochemical Co.’s Ethylene Oxide Reactor in order to find probable hazardous scenarios. In this project, probable accidents were modelled and evaluated by Phast software in different scenarios, and the outcomes were investigated. In addition, if necessary, a set of solutions were proposed to decrease casualties in hazardous scenarios. The results may be used to change layouts according to Consequence Modelling. Results illustrated that...
Constructive Mathematics and Quantum Mechanics
, M.Sc. Thesis Sharif University of Technology ; Ardeshir, Mohammad (Supervisor)
Abstract
In constructive mathematics, one has to construct a mathematical object in order to show that it exists. Consequently, some of classical theorems are not acceptable from a constructive point of view. In particular, the constructive validity of the parts of mathematics that play a role in forming physical theories is of interest. Here, we want to examine the constructive provability of some theorems related to quantum mechanics
Control of Three-phase UPS with Nonlinear Load Using Disturbance Observer Considering Transformer Concerns
, M.Sc. Thesis Sharif University of Technology ; Tahami, Farzad (Supervisor)
Abstract
Nowadays, non-linear loads comprise an important part of electrical grids. One of the most essential sources of nonlinear loads is switching power supplies, which mainly include power electronic rectifiers. When power outage occurs, Uninterruptible Power Supplies (UPS) must be able to supply these loads. The nonlinearity of the load has a significant effect on the Total Harmonic Distortion (THD) of the output voltage, which may not be easily reduced, especially in three-phase inverters. Furthermore, the presence of isolating transformers in these power supplies limits the control of harmonics and intensifies the nonlinear effects of the system.In this Master Thesis, a disturbance observer is...