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kermani--ali
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The effect of tricalcium silicate incorporation on bioactivity, injectability, and mechanical properties of calcium sulfate/bioactive glass bone cement
, Article Ceramics International ; Volume 49, Issue 10 , 2023 , Pages 15003-15014 ; 02728842 (ISSN) ; Mashayekhan, S ; Kermani, F ; Abdekhodaie, M. J ; Sharif University of Technology
Elsevier Ltd
2023
Abstract
The conventional Polymethyl methacrylate (PMMA) bone cement is not biodegradable and not bioactive to bond with the native bone and causes tissue necrosis resulting from its high exothermic polymerization. Hence, biodegradable bioactive bone cements with suitable setting time and mechanical properties should be introduced. In this study, novel bioactive bone cements containing Calcium Sulfate Hemihydrate (CSH), Bioactive Glass (BG), and Tricalcium Silicate (TSC) were developed. Firstly, CSH and BG binary system was optimized based on preliminary setting and mechanical tests. Secondly, the composite bioactive bone cements were obtained by adding different quantities of TCS to the optimized...
A novel game theoretic approach for modeling competitive information diffusion in social networks with heterogeneous nodes
, Article Physica A: Statistical Mechanics and its Applications ; Volume 466 , 2017 , Pages 570-582 ; 03784371 (ISSN) ; Fatemi Ardestani, S. F ; Aliahmadi, A ; Barzinpour, F ; Sharif University of Technology
Elsevier B.V
2017
Abstract
Influence maximization deals with identification of the most influential nodes in a social network given an influence model. In this paper, a game theoretic framework is developed that models a competitive influence maximization problem. A novel competitive influence model is additionally proposed that incorporates user heterogeneity, message content, and network structure. The proposed game-theoretic model is solved using Nash Equilibrium in a real-world dataset. It is shown that none of the well-known strategies are stable and at least one player has the incentive to deviate from the proposed strategy. Moreover, violation of Nash equilibrium strategy by each player leads to their reduced...
Distributed Computation of Centrality Measures in Dynamic Complex Networks
, M.Sc. Thesis Sharif University of Technology ; Hematyar, Ali Mohammad Afshin (Supervisor) ; Kavousi, Kaveh (Supervisor)
Abstract
Complex networks represent a wide diversity of systems in nature and human interactions. Networks are graphs that describe the structures of interacting systems and give significant information about the patterns of connections between the nodes in a particular system. In turn, having knowledge about the structure of networks and their arrangements enables one to make certain types of predictions about their behavior of network.Network methods have had profound influence in many domains and fields in the past decade. Centrality measures are very important tool for analysis complex networks, in real-world complex networks are heterogeneous structures, all their components such as nodes...
Secure steganography using Gabor filter and neural networks
, Article Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) ; Volume 4920 LNCS , 2008 , Pages 33-49 ; 03029743 (ISSN); 3540690166 (ISBN); 9783540690160 (ISBN) ; Zahedi Kermani, Z ; Sharif University of Technology
2008
Abstract
The main concern of steganography (image hiding) methods is to embed a secret image into a host image in such a way that it causes minimum distortion to the host; to make it possible to extract a version of secret image from the host in such a way that the extracted version of secret image be as similar as possible to its original version (this should be possible even after usual attacks on the host image), and to provide ways of embedding secret images with larger size into a given host image. In this paper we propose a method that covers all above mentioned concerns by suggesting the idea of finding from an image data base, the most suitable host for a given secret image. In our method,...
A robust steganography algorithm based on texture similarity using Gabor filter
, Article 5th IEEE International Symposium on Signal Processing and Information Technology, Athens, 18 December 2005 through 21 December 2005 ; Volume 2005 , 2005 , Pages 578-582 ; Jamzad, M ; Sharif University of Technology
2005
Abstract
The main concern of steganography (image hiding) methods is to embed a secret image into a host image in such a way that the host should remain as similar as possible to its original version. In addition the host image should remain robust with respect to usual attacks. In this paper we present a method that tries to cover all above mentioned concerns. The secret and host images are divided into blocks of size 4 × 4. Each block in secret image is taken as a texture pattern for which the most similar block is found among the blocks of the host image. The embedding procedure is carried on by replacing these small blocks of the secret image with blocks in host image in such a way that least...
An All-Optical NoC with Multicasting Capability
, M.Sc. Thesis Sharif University of Technology ; Hesabi, Shahin (Supervisor)
Abstract
The importance of power consumption in high performance multiprocessors, combined with power reduction capability of on-chip optical interconnects, offers optical network-on-chip (ONoC) as a new technology solution which can deliver considerably higher bandwidth and lower latencies with significantly lower power dissipation than an interconnection network based only on electronic signaling. An on-chip network should be able to support multicast communications efficiently whether it is an optical or electrical network. On the other hand, multicast communications in optical networks-on-chip has been implemented using shared bus which is not scalable. Moreover, most of optical on-chip...
Inertial Guidance and Control of an Axisymmetric Flying Vehicle with a Spinning Part
, M.Sc. Thesis Sharif University of Technology ; Nobahari, Hadi (Supervisor)
Abstract
In this work, inertial guidance and control of an axisymmetric flying vehicle with a spinning part is performed based on dynamic modeling and seven degree of freedom simulation. Flying vehicle is composed of front and aft bodies and these bodies are connected to each other via a hydrodynamic bearing. Front body is roll isolated from the aft body and includes all necessary guidance and control equipments such as sensors, canard set and so on. The control fins, located on the nose, is used to control the roll angle of the nose and to execute the lateral acceleration commands. Also, the aft body is freely rolling and includes the stabilizing fins. In this project, the translational and...
Macrostructure and Mechanical Properties of Structural Composite of Aluminum and Stainless Steel Net Processed by Casting and Rolling
, M.Sc. Thesis Sharif University of Technology ; Akbarzadeh, Abbas (Supervisor)
Abstract
Having the high strength to weight ratio has been made the composites special materials very important these days. The low density of aluminum and its appropriate corrosion properties make it a good choice for metallic matrix. Also, the high tensile strength of stainless steel fibers can helps as a reinforcement in the composite to improve its mechanical properties. Enhancing the bonding of composite’s components can helps it to develop its properties. Casting is an appropriate process for making an aluminum matrix containing steel fibers as reinforcement in a structural composite. In addition, rolling process can remove so many defects made by casting, and improve joining of fibers and...
Free Vibration Analysis of a Functionally Graded Nanotube Under an Initial Stress Using Nonlocal Elasticity Theory
, M.Sc. Thesis Sharif University of Technology ; Eskandari, Morteza (Supervisor)
Abstract
In this study, flexural vibration of a functionally graded nanotube under an initial stress is investigated. The small scale effect is taken into consideration based on Eringen’s nonlocal elasticity theory. The material properties are assumed to vary exponentially along the depth direction. The complete effect of the initial stress is taken into account in the problem formulation. The governing equations of motion are derived by using the Hamilton’s principle on the basis of the nonlocal Timoshenko beam theory. An analytical solution of the governing equations, for free vibration of a simply-supported nanotube is presented. Numerical results are presented to investigate the effect of the...
Approximation Algorithms for the Matroid-Constraint Maximum Subdeterminant
, M.Sc. Thesis Sharif University of Technology ; Ebrahimi Brojeni, Javad (Supervisor)
Abstract
let Mn n be a positive semmi definite matrix and M:= (U; B) be a matroid. Consider the problem of finding S 2 B such that det(MS;S) is maximized, in witch MS; S is the submatrix of M, restricted to rows and columns of S. This problem has a variety of applications including page ranking algorithms. The problem above is an NP-hard problem in the general case. However, there are several approximating and estimating algorithms for some special cases, which are interesting. Also, exactly solving the problem is NP-hard, even for some special matroids. As an example, one can consider the uniform matroids. Khachiyan introduced a greedy algorithm with dd approximation factor. Afterward, Di summa et...
PAPR reduction of OFDM signals using harmony search algorithm
, Article 2011 18th International Conference on Telecommunications, ICT 2011, 8 May 2011 through 11 May 2011, Ayia Napa ; 2011 , Pages 90-94 ; 9781457700248 (ISBN) ; Salehinejad, H ; Talebi, S ; Sharif University of Technology
2011
Abstract
Orthogonal frequency division multiplexing (OFDM) is one of the widely used multiplexing techniques in wireless communications and especially cognitive radio networks. One of the key challenges of this technique is its high peak to average power ratio (PAPR) of the transmitted signal. This paper, introduces a new approach to PAPR reduction of OFDM signals using harmony search algorithm (HSA) based on the partial transmit sequence (PTS) method. The simulation results demonstrate that the proposed algorithm has better PAPR reduction performance as an accurate and low complexity approach for OFDM systems
Image Enhancement via Sparse Decomposition
, M.Sc. Thesis Sharif University of Technology ; Babaiezadeh, Massoud (Supervisor)
Abstract
Sparse decomposition has recently attracted the attention of many researchers in dierent areas of signal processing. In mathematical viewpoint, sparse decomposition is nding a sparse solution of an Underdetermined System of Linear Equations (USLE). This concept has many applications in dierent signal processing elds including blind sourse separation, optical character recognition and image processing. In this thesis, we investigate the application of sparse decomposition in image denoising. One of the image denoising methods which is related to sparse decomposition concepts is the \transfrom domain method". In this method, the noisy image is rst transformed to another domain, and then noise...
Effect of porosity variation in determination of stagnant and dispersion thermal conductivities in the resin transfer molding process
, Article Heat Transfer Research ; Volume 43, Issue 7 , 2012 , Pages 651-667 ; 10642285 (ISSN) ; Rabani, R ; Kermani, M. J ; Sharif University of Technology
2012
Abstract
A numerical analysis for determination of the stagnant and dispersion thermal conductivities in the Resin Transfer Molding (RTM) process is presented. A solution was obtained for the momentum and energy equations, which are used in this study and which represent the Brinkman- Forchheimer-extended Darcy model, and one-temperature energy equation. Subject to the appropriate boundary conditions, the governing equations are solved by the finite volume method on a collocated grid. In order to satisfy the pressure-velocity coupling in the solution, the SIMPLE algorithm was used and for determining the mass flux flowing past the cell faces, the Rhie-Chow interpolation was applied. Both constant and...
A Robust CVaR Model under Uncertainty for IMRT Treatment Planning
, M.Sc. Thesis Sharif University of Technology ; Najafi, Mehdi (Supervisor) ; Rafiee, Majid (Co-Supervisor)
Abstract
Nowadays, radiation therapy is one of the most common methods for the cancer treatment. Intensity Modulated Radiation Therapy(IMRT) is a novel technique of radiation therapy that aims to delivere sufficient dose to cancerous tissues while sparing healthy organs. There are various uncertainties in radiation therapy problems, including uncertainty about device setup, device errors, interfraction and intrafraction motions. One of the most important uncertainties is the movement of the tumor during the treatment process(intrafraction motion), as this displacement may cause the cancer tissue to not receive sufficient dose and also to damage the healthy tissue due to a violation of their dose...
Experimental Investigation into the Direct Contact of Working Fluid with Phase Change Material and its Effect on the Heat Transfer Rate
, M.Sc. Thesis Sharif University of Technology ; Shafii, Mohammad Behshad (Supervisor)
Abstract
The unique properties of phase change materials (PCMs), such as high latent heat and nearly constant phase change temperature, have made them a suitable option for use in thermal energy storage systems and thermal management systems. However, the low thermal conductivity of these materials has imposed limitations on their widespread use in industries. In this study, for the first time, the effect of injecting a boiling fluid (BF) into the PCM container to enhance heat transfer and accelerate the solidification process has been experimentally investigated. In this regard, paraffin wax and acetone have been selected as the PCM and the BF, and the effects of parameters such as the initial...
Differentially private all-pairs shortest distances for low tree-width graphs
, Article 2023 International Symposium on Networks, Computers and Communications, ISNCC 2023 ; 2023 ; 979-835033559-0 (ISBN) ; Tofighi Mohammadi, A ; Kermani, F ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2023
Abstract
In this paper, we present a polynomial time algorithm for the problem of differentially private all pair shortest distances over the class of low tree-width graphs. Our result generalizes the result of Sealfon [10] for the case of trees to a much larger family of graphs. Furthermore, if we restrict to the class of low tree-width graphs, the additive error of our algorithm is significantly smaller than that of the best known algorithm for this problem, proposed by Chen et. al. in [3]. © 2023 IEEE
On the Effects of Change in the Ownership of Natural Resource Revenues on Government Performance Enhancement and People Welfare
, M.Sc. Thesis Sharif University of Technology ; Nili, Masoud (Supervisor)
Abstract
The poor economic performance of natural resource abundant countries has been studied for a long time and in order to alleviate this problem some different solutions are suggested by economists. One stream among these solutions are those focusing on the distribution mechanism of natural resource revenues and the ownership of these resources. In this study, it is intended to address the effect of change in the ownership of natural resources on politicians’ behavior and people welfare by using political economy approach. Also the optimal share of people from natural resources as a function of political and economic institutions is discussed. In this study, it is shown theoretically that under...
Efficient and concurrent reliable realization of the secure cryptographic SHA-3 algorithm
, Article IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems ; Vol. 33, issue. 7 , July , 2014 , p. 1105-1109 ; 0278-0070 ; Mozaffari-Kermani, M ; Reyhani-Masoleh, A ; Sharif University of Technology
2014
Abstract
The secure hash algorithm (SHA)-3 has been selected in 2012 and will be used to provide security to any application which requires hashing, pseudo-random number generation, and integrity checking. This algorithm has been selected based on various benchmarks such as security, performance, and complexity. In this paper, in order to provide reliable architectures for this algorithm, an efficient concurrent error detection scheme for the selected SHA-3 algorithm, i.e., Keccak, is proposed. To the best of our knowledge, effective countermeasures for potential reliability issues in the hardware implementations of this algorithm have not been presented to date. In proposing the error detection...
Flooding and dehydration diagnosis in a polymer electrolyte membrane fuel cell stack using an experimental adaptive neuro-fuzzy inference system
, Article International Journal of Hydrogen Energy ; Volume 47, Issue 81 , 2022 , Pages 34628-34639 ; 03603199 (ISSN) ; Alasty, A ; Kermani, M. J ; Asghari, S ; Sharif University of Technology
Elsevier Ltd
2022
Abstract
Today the need for fault diagnosis in polymer electrolyte membrane fuel cells (PEMFCs) is felt more than ever to increase the useful life and durability of the cell. The present study proposes an indirect in-situ experimental-based algorithm for diagnosing the moisture content issues in a three-cell stack. Three adaptive neuro-fuzzy inference systems (ANFIS) approximate the system outputs (cells voltages, cathodic and anodic pressure drop) in normal conditions. The values of Pearson's correlation coefficients (0.998, 0.983, and 0.995 for outputs, respectively) show the high quality of the modeling. In unknown operating conditions, the residuals of experimental and ANFIS values are compared...
Fault-resilient lightweight cryptographic block ciphers for secure embedded systems
, Article IEEE Embedded Systems Letters ; Vol. 6, issue. 4 , 2014 , pp. 89-92 ; ISSN: 19430663 ; Tian, K ; Azarderakhsh, R ; Bayat Sarmadi, S ; Sharif University of Technology
2014
Abstract
The development of extremely-constrained embedded systems having sensitive nodes such as RFID tags and nanosensors necessitates the use of lightweight block ciphers. Nevertheless, providing the required security properties does not guarantee their reliability and hardware assurance when the architectures are prone to natural and malicious faults. In this letter, error detection schemes for lightweight block ciphers are proposed with the case study of XTEA (eXtended TEA). Lightweight block ciphers such as XTEA, PRESENT, SIMON, and the like might be better suited for low-resource deeply-embedded systems compared to the Advanced Encryption Standard. Three different error detection approaches...