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    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) Mirheidari, S. A ; 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) Mirheidari, S. A ; 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) Mirheidari, S. A ; 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... 

    An Alert Correlation System with the Throughput of Multi-Thousands Events per Second

    , M.Sc. Thesis Sharif University of Technology Mirheidari, Ali (Author) ; 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... 

    Mathematical study of probe arrangement and nanoparticle injection effects on heat transfer during cryosurgery

    , Article Computers in Biology and Medicine ; Volume 66 , Nov , 2015 , Pages 113-119 ; 00104825 (ISSN) Mirkhalili, S. M ; Ramazani S. A. A ; Nazemidashtarjandi, S ; Sharif University of Technology
    Elsevier Ltd  2015
    Abstract
    Blood vessels, especially large vessels have a greater thermal effect on freezing tissue during cryosurgery. Vascular networks act as heat sources in tissue, and cause failure in cryosurgery and reappearance of cancer. The aim of this study is to numerically simulate the effect of probe location and multiprobe on heat transfer distribution. Furthermore, the effect of nanoparticles injection is studied. It is shown that the small probes location near large blood vessels could help to reduce the necessary time for tissue freezing. Nanoparticles injection shows that the thermal effect of blood vessel in tissue is improved. Using Au, Ag and diamond nanoparticles have the most growth of ice ball... 

    Mechanical, rheological and oxygen barrier properties of ethylene vinyl acetate/diamond nanocomposites for packaging applications

    , Article Diamond and Related Materials ; Volume 99 , 2019 ; 09259635 (ISSN) Amini, M ; Ramazani S. A., A ; Haddadi, S. A ; Kheradmand, A ; Sharif University of Technology
    Elsevier Ltd  2019
    Abstract
    In this work, the effects of the surface-modified nanodiamond particles (NDs) on the barrier, rheological, mechanical and thermal properties of ethylene vinyl acetate (EVA) composites for the packaging applications were investigated. Fourier transform infrared spectroscopy, as well as thermal gravimetric analysis were employed to study the grafting of vinyltriethoxy silane (VTS) on the surface of NDs. Afterwards, EVA samples containing 0, 0.1, 0.5, 1, 1.5 and 2 wt% of surface-modified NDs were prepared by a two-stage process including the solution and injection processes. In order to evaluate the physicochemical, rheological, mechanical and thermal properties of the EVA/NDs samples, field... 

    Effect of bonding parameters on microstructure development during TGTLP bonding of Al7075 alloy

    , Article Philosophical Magazine ; Vol. 94, issue. 11 , Mar , 2014 , pp. 1166-1176 ; ISSN: 14786435 Afghahi, S. S. S ; Ekrami, A ; Farahany, S ; Jahangiri, A ; Sharif University of Technology
    2014
    Abstract
    The effect of temperature, pressure and bonding time on microstructure of temperature gradient transient liquid phase (TGTLP) diffusion bonded Al7075 alloy using liquid gallium interlayer was investigated. The selected bonding method relies on using the minimum amount of liquid gallium on faying surfaces, using a very fast heating rate to reach the joining temperature and imposing a temperature gradient across the bond region. The microstructure of the diffusion bonded joints was evaluated by light optical microscopy, scanning electron microscopy and energy dispersive spectroscopy (EDS). Results show that by increasing the temperature, pressure and time of joining, a more uniform... 

    Kalman filter based packet loss replacement in presence of additive noise

    , Article 2012 25th IEEE Canadian Conference on Electrical and Computer Engineering: Vision for a Greener Future, CCECE 2012 ; 2012 ; 9781467314336 (ISBN) Miralavi, S. R ; Ghorshi, S ; Tahaei, A
    2012
    Abstract
    A major problem in real-time packet-based communication systems, is misrouted or delayed packets which results in degraded perceived voice quality. If packets are not available on time, the packets are considered as lost. The easiest solution in a network terminal receiver is to replace silence for the duration of lost speech segments. In a high quality communication system, to avoid degradation in speech quality due to packet loss, a suitable method or algorithm is needed to replace the missing segments of speech. In this paper, we introduce an adaptive filter for replacement of lost speech segment. In this method Kalman filter as a state-space based method will be used to predict the... 

    Effect of reactive diluent on gas separation behavior of photocurable acrylated polyurethane composite membranes

    , Article Journal of Applied Polymer Science ; Volume 137, Issue 3 , 15 January , 2020 Molavi, H ; Shojaei, A ; Mousavi, S. A ; Ahmadi, S. A ; Sharif University of Technology
    John Wiley and Sons Inc  2020
    Abstract
    In this study, the effects of the type and content of reactive diluents on the permeation/separation of carbon dioxide/nitrogen (CO2/N2) through acrylate-terminated polyurethane (APU)-acrylate/acrylic diluent (APUA) composite membranes was investigated. A series of APUs based on poly(ethylene glycol) (PEG)-1000 g mol−1, toluene diisocyanate, and 2-hydroxyethyl methacrylate was synthesized and then diluted with several reactive diluents. The results obtained from differential scanning calorimetry (DSC) and Fourier transform infrared analyses showed that the microphase interference of hard and soft segments increased with increasing reactive diluent content. Furthermore, with increasing alkene... 

    Study of thermal behavior of α-PbO2, using TG and DSC

    , Article Journal of Thermal Analysis and Calorimetry ; Volume 92, Issue 3 , 2008 , Pages 917-920 ; 13886150 (ISSN) Sajadi, S. A. A ; Alamolhoda, A. A ; Hashemian, S. J ; Sharif University of Technology
    2008
    Abstract
    Using two techniques of thermogravimetry and differential scanning calorimetry under O2 gas atmosphere from 25 to 600°C, the thermal behavior of laboratory-produced compound lead(IV) oxide α-PbO2 was investigated. The identity of products at different stages were confirmed by XRD technique. Both techniques produced similar results supporting the same decomposition stages for the compound. Three distinct energy changes were observed, namely, two endothermic and one exothermic in DSC. The amount of ΔH for each peak is also reported. © 2008 Springer Science+Business Media, LLC  

    Thermal behavior of alkaline lead acetate, a study of thermogravimetry and differential scanning calorimetry

    , Article Scientia Iranica ; Volume 15, Issue 4 , 2008 , Pages 435-439 ; 10263098 (ISSN) Sajadi, S. A. A ; Alamolhoda, A. A ; Hashemian, S. J ; Sharif University of Technology
    Sharif University of Technology  2008
    Abstract
    The compound, alkaline lead acetate, Pb(CH3COO)2·PbO·H2O (ALA), was purchased from the Fluka Company. The X-ray diffraction film and SEM electron microgaph of this compound were obtained and reported in this paper for the first time. The thermal behavior of alkaline lead acetate (ALA) was studied using thermogravimetery (TGA) and Differential Scanning Calorimetery (DSC) techniques under an O2 gas atmosphere from 25 to 600°C. Four distinct energy changes associated with weight changes were observed, all of them being exothermic in the DSC results. The amount of ΔH for each peak is reported. © Sharif University of Technology  

    An investigation into the structure and thermal properties of lead hydroxide

    , Article Scientia Iranica ; Volume 14, Issue 2 , 2007 , Pages 169-173 ; 10263098 (ISSN) Sajadi, S. A. A ; Alamolhoda, A. A ; Hashemian, S. J ; Sharif University of Technology
    Sharif University of Technology  2007
    Abstract
    The compound, lead hydroxide Pb6O4(OH)4, was prepared by a method used for the first time in the authors laboratory. The compound was identified by XRD and it's purity was determined by analytical methods (100%). The thermal characteristics of this compound were investigated by using a thermogravimetry (TGA). This compound was found to be stable at room temperature and at 160°C will decompose completely to produce lead (II) oxide. © Sharif University of Technology, April 2007  

    Mechanical and piezoelectric characterizations of electrospun PVDF-nanosilica fibrous scaffolds for biomedical applications

    , Article 2017 INN International Conference/Workshop on Nanotechnology and Nanomedicine, NTNM 2017, 2 May 2017 through 3 May 2017 ; Volume 5, Issue 7 , 2018 , Pages 15710-15716 ; 22147853 (ISSN) Haddadi, S. A ; Ghaderi, S ; Amini, M ; Ramazani, S. A. A ; Sharif University of Technology
    Elsevier Ltd  2018
    Abstract
    The effects of hydrophilic and hydrophobic nanosilica (SiO2) on the morphology, mean diameter distribution of fibers, mechanical and piezoelectric properties of poly (vinylidene fluoride) (PVDF) nanofibers were studies. We prepared Nanofibers by the electrospinning of PVDF solutions containing 1.5 wt.% both hydrophilic and hydrophobic nano-SiO2 loadings. Morphology and diameter distribution of the electrospun nanofibers were studied using field emission scanning electron microscopy (FE-SEM) analysis. Tensile test was used to study the effect of both types of nanosilica on the tensile strength, young's modulus and strain at break. Piezoelectric characterization of the electrospun fibers were... 

    Determining of the optimized dimensions of the Marinelli beaker containing source with inhomogeneous emission rate by using genetic algorithm coupled with MCNP and determining distribution type by neural networks

    , Article Applied Radiation and Isotopes ; Volume 157 , 2020 Zamzamian, S. M ; Hosseini, S. A ; Feghhi, S. A ; Samadfam, M ; Sharif University of Technology
    Elsevier Ltd  2020
    Abstract
    In order to determine the activity of C137s in soil resulting from nuclear accidents or fallouts, the best choice is to use HPGe detectors due to their best energy resolutions. In this regard, in order to enhance the detection efficiency, the Marinelli beakers have been used to increase the radiation interaction with the sensitive volume of the detector. In previous works, to optimize the dimension of Marinelli beakers, the assumption was that the emission rate of the source is homogeneous in beaker volume. In the present study, to investigate the effect of the inhomogeneous emission rate of the source on the optimum dimensions of the beaker, in a simple case, the beaker was divided into two... 

    Fabrication and characterization of a polysulfone-graphene oxide nanocomposite membrane for arsenate rejection from water

    , Article Journal of Environmental Health Science and Engineering ; Volume 13, Issue 1 , 2015 ; 2052336X (ISSN) Rezaee, R ; Nasseri, S ; Mahvi, A. H ; Nabizadeh, R ; Mousavi, S. A ; Rashidi, A ; Jafari, A ; Nazmara, S ; Sharif University of Technology
    BioMed Central Ltd  2015
    Abstract
    Background: Nowadays, study and application of modified membranes for water treatment have been considered significantly. The aim of this study was to prepare and characterize a polysulfone (PSF)/graphene oxide (GO) nanocomposite membrane and to evaluate for arsenate rejection from water. Materials and methods: The nanocomposite PSF/GO membrane was fabricated using wet phase inversion method. The effect of GO on the synthesized membrane morphology and hydrophilicity was studied by using FE-SEM, AFM, contact angle, zeta potential, porosity and pore size tests. The membrane performance was also evaluated in terms of pure water flux and arsenate rejection. Results: ATR-FTIR confirmed the... 

    Improvement of polymer flooding using in-situ releasing of smart nano-scale coated polymer particles in porous media

    , Article Energy Exploration and Exploitation ; Volume 30, Issue 6 , 2012 , Pages 915-940 ; 01445987 (ISSN) Ashrafizadeh, M ; Ramazani, S. A. A ; Sadeghnejad, S ; Sharif University of Technology
    2012
    Abstract
    The main purpose of this paper is modeling and simulation of in-situ releasing of smart nano-sized core-shell particles at the water-oil interface during polymer flooding. During the polymer flooding process, when these nano-particles reach the water-oil interface, migrate to the oil phase and the hydrophobic layer of them dissolves in this phase. After dissolution of this protective nano-sized layer, the hydrophilic core containing a water-soluble ultra high molecular weight polymer diffuses back into the water phase and with dissolving in this phase, dramatically increases viscosity of flooding water in the neighborhood of the water-oil interface. In this study, two different... 

    Microstructural evolution in damaged IN738LC alloy during various steps of rejuvenation heat treatments

    , Article Journal of Alloys and Compounds ; Volume 512, Issue 1 , January , 2012 , Pages 340-350 ; 09258388 (ISSN) Hosseini, S. S ; Nategh, S ; Ekrami, A. A ; Sharif University of Technology
    2012
    Abstract
    IN738LC is one of the superior nickel base superalloys utilized at high temperatures in aggressive environments. However, experiencing high temperatures and stresses during service causes microstructure deterioration and degradation of mechanical properties in this alloy. To restore the microstructure and mechanical properties of the degraded alloy, rejuvenation heat treatments can be considered. In this study, the evolution of microstructural features in a creep damaged IN738LC superalloy during different stages of rejuvenation heat treatment cycles was investigated. During solution treatment stage, dissolution of coarsened γ′ precipitates, grain boundary films and transition zone around... 

    Changes of γ′ precipitate characteristics in damaged superalloy IN738LC during different stages of rejuvenation heat treatment cycles

    , Article Materials Science and Technology ; Volume 28, Issue 2 , Nov , 2012 , Pages 213-219 ; 02670836 (ISSN) Hosseini, S. S ; Nategh, S ; Ekrami, A. A ; Sharif University of Technology
    2012
    Abstract
    The present study investigates the evolution of γ′ precipitate microstructure in a creep damaged IN738LC superalloy during different stages of rejuvenation heat treatment cycles. Dissolution of coarsened γ′ precipitates in the creep damaged alloy occurred during different solution treatments. The precipitates that did not dissolve completely during solution treatment and those formed during subsequent cooling were considered to be as remnant and cooling precipitates respectively. It was found that higher solution treatment temperatures result in lower volume fraction of remnant precipitates and further formation of cooling precipitates. Slower cooling rates after solution treatment gave the... 

    Fabrication and characterization of conductive chitosan/gelatin-based scaffolds for nerve tissue engineering

    , Article International Journal of Biological Macromolecules ; Volume 74 , 2015 , Pages 360-366 ; 01418130 (ISSN) Baniasadi, H ; Ramazani S. A., A ; Mashayekhan, S ; Sharif University of Technology
    2015
    Abstract
    This paper reports on the development of conductive porous scaffolds by incorporating conductive polyaniline/graphene (PAG) nanoparticles into a chitosan/gelatin matrix for its potential application in peripheral nerve regeneration. The effect of PAG content on the various properties of the scaffold is investigated and the results showed that the electrical conductivity and mechanical properties increased proportional to the increase in the PAG loading, while the porosity, swelling ratio and in vitro biodegradability decreased. In addition, the biocompatibility was evaluated by assessing the adhesion and proliferation of Schwann cells on the prepared scaffolds using SEM and MTT assay,... 

    BOT-MICS: Bounding time using analytics in mixed-criticality systems

    , Article IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems ; Volume 41, Issue 10 , 2022 , Pages 3239-3251 ; 02780070 (ISSN) Ranjbar, B ; Hosseinghorban, A ; Sahoo, S. S ; Ejlali, A ; Kumar, A ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2022
    Abstract
    An increasing trend for reducing cost, space, and weight leads to modern embedded systems that execute multiple tasks with different criticality levels on a common hardware platform while guaranteeing a safe operation. In such mixed-criticality (MC) systems, multiple worst case execution times (WCETs) are defined for each task, corresponding to the system operation mode to improve the MC system's timing behavior at runtime. Determining the appropriate WCETs for lower criticality (LC) modes is nontrivial. On the one hand, considering a very low WCET for tasks can improve the processor utilization by scheduling more tasks in that mode, on the other hand, using a larger WCET ensures that the...