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mohsenzadeh--milad
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Histogram shift steganography: A technique to thwart histogram based steganalysis
, Article 2nd International Workshop on Computer Science and Engineering, WCSE 2009, 28 October 2009 through 30 October 2009, Qingdao ; Volume 2 , 2009 , Pages 166-170 ; 9780769538815 (ISBN) ; Mohajeri, J ; Ghaemmaghami, S ; Sharif University of Technology
2009
Abstract
We present an image steganographic technique to preserve the first-order and the second-order statistics of the host image. Experimental results show that the proposed method can preserve the image quality and also resists typical statistical analysis based attacks. The new steganography method solves the distortion problem with the HKC algorithm and hence thwarts the Kuo attack. The method is based on the idea of histogram shift, in which two empty bins are produced in the image histogram that are then filled up using their neighboring bins through the embedding process. © 2009 IEEE
Time-Cost efficient scheduling algorithms for executing workflow in infrastructure as a service clouds
, Article Wireless Personal Communications ; Volume 103, Issue 3 , 2018 , Pages 2035-2070 ; 09296212 (ISSN) ; Movaghar, A ; Mohsenzadeh, M ; Sharif University of Technology
Springer New York LLC
2018
Abstract
Cloud Computing enables delivery of IT resources over the Internet and follows the pay-as-you-go billing model. The cloud infrastructures can be used as an appropriate environment for executing of workflow applications. To execute workflow applications in this environment, it is necessary to develop the workflow scheduling algorithms that consider different QoS parameters such as execution time and cost. Therefore, in this paper we focus on two criteria: total completion time (makespan) and execution cost of workflow, and propose two heuristic algorithms: MTDC (Minimum Time and Decreased Cost) which aims to create a schedule that minimizes the makespan and decreases execution cost, and CTDC...
A budget constrained scheduling algorithm for executing workflow application in infrastructure as a service clouds
, Article Peer-to-Peer Networking and Applications ; 2018 , Pages 1-28 ; 19366442 (ISSN) ; Movaghar, A ; Mohsenzadeh, M ; Sharif University of Technology
Springer New York LLC
2018
Abstract
Cloud computing technology, which is a new model of service provisioning in distributed systems, has been raised as a way to execute workflow applications. To profit from this technology for executing workflow applications, it is necessary to develop workflow scheduling algorithms that consider different QoS parameters such as execution time and cost. Therefore, in this paper, we focus on two criteria: makespan (completion time) and execution cost of workflow application and propose a scheduling algorithm named CB-DT (Constrained Budget-Decreased Time) which aims to create a schedule that decreases the makespan while satisfying the budget constraint of the workflow application. In the...
Robusting Series Structure of Semiconductor Switches for High Voltage Applications
, Ph.D. Dissertation Sharif University of Technology ; Kaboli, Shahriyar (Supervisor)
Abstract
The series structure of semiconductor devices has a wide application in the industry and research field. The most critical issue in the series structure of series switches is the safe operating condition provision. Hence many kinds of research have been intensively focused on this topic to overcome this necessity. However, many existing aspects relevant to the series stacking of the semiconductor switches have not been pointed out. These include, the power loss must be accepted for the series devices and recovery of this power, providing balanced voltage for the series devices through a simple and easy implementing structure and providing a safe voltage condition for the series devices under...
A budget constrained scheduling algorithm for executing workflow application in infrastructure as a service clouds
, Article Peer-to-Peer Networking and Applications ; Volume 12, Issue 1 , 2019 , Pages 241-268 ; 19366442 (ISSN) ; Movaghar, A ; Mohsenzadeh, M ; Sharif University of Technology
Springer New York LLC
2019
Abstract
Cloud computing technology, which is a new model of service provisioning in distributed systems, has been raised as a way to execute workflow applications. To profit from this technology for executing workflow applications, it is necessary to develop workflow scheduling algorithms that consider different QoS parameters such as execution time and cost. Therefore, in this paper, we focus on two criteria: makespan (completion time) and execution cost of workflow application and propose a scheduling algorithm named CB-DT (Constrained Budget-Decreased Time) which aims to create a schedule that decreases the makespan while satisfying the budget constraint of the workflow application. In the...
Does the short-term boost of renewable energies guarantee their stable long-term growth? Assessment of the dynamics of feed-in tariff policy
, Article Renewable Energy ; Volume 159 , October , 2020 , Pages 1252-1268 ; Hamed Shakouri, G ; Mashayekhi, A. N ; Kazemi, A ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
Feed-in tariff (FiT) is one of the most efficient ways that many governments throughout the world use to stimulate investment in renewable energies (REs) technology. For governments, financial management of the policy could be challenging as it needs a considerable amount of budget to support RE producers during the long remuneration period. In this paper, it has been illuminated that the early growth of REs capacity could be a temporary boost. And the socio-economic structure of the system will backlash the policy if some social mechanisms are not considered. Social tolerance for paying REs tax and potential investors’ trust emanated from budget-related mechanisms -which have rarely been...
An enhancement in the photocatalytic activity of TiO 2 by the use of Pd: The question of layer sequence in the resulting hierarchical structure
, Article Journal of Coatings Technology Research ; Volume 8, Issue 1 , January , 2011 , Pages 75-81 ; 15470091 (ISSN) ; Ghorbani, M ; Mohsenzadeh, M ; Sharif University of Technology
2011
Abstract
TiO 2 and Pd-modified TiO 2 photocatalysts were prepared by sol-gel method. X-ray diffraction (XRD) data showed that the presence of Pd in TiO 2 catalyst decreases the crystalline size of TiO 2 and stabilizes anatase phase. The study of the photocatalytic activity of the films via Linear Sweep Voltametry (LSV) plots and antibacterial test against Escherichia coli ATCC 25922-a gram negative bacterium-showed that Pd increases the photocatalytic activity of the coatings. Besides, the sequence of layer deposition (TiO 2 and Pd-modified TiO 2) influences the photocatalytic properties. In other words, more photocatalytic activity is obtained when Pd-modified layer is deposited first
Damage detection of L-shaped beam structure with a crack by electromechanical impedance response: analytical approach and experimental validation
, Article Journal of Nondestructive Evaluation ; Volume 39, Issue 2 , 2020 ; Barzegar, M ; Mohsenzadeh, M ; Sharif University of Technology
Springer
2020
Abstract
Damage detection and structural health monitoring using the electromechanical impedance method has been accepted as an effective technique between various approaches of nondestructive evaluation. Many efforts have been made on experimental methods for obtaining the impedance of structures. However, expensive experimental methods encourage researchers to develop theoretical models. In this paper, a new theoretical model is developed for damage detection of L-shaped beams, which are basic components in frame structures, with an embedded piezoelectric wafer active sensor. For this purpose, a chirp signal of voltage is used to activate a piezoelectric patch for inducing local strains that lead...
A novel concentrating photovoltaic/thermal solar system combined with thermoelectric module in an integrated design
, Article Renewable Energy ; Volume 113 , 2017 , Pages 822-834 ; 09601481 (ISSN) ; Shafii, M. B ; Jafari mosleh, H ; Sharif University of Technology
Elsevier Ltd
2017
Abstract
The use of solar energy concentration systems for achieving performance enhancements in the Photovoltaic/thermal hybrid solar systems and reduction of initial costs is an idea that has been studied for years. In this article a new structure for parabolic trough photovoltaic/thermal collector is proposed and its thermal and electrical performances are experimentally investigated. The receiver of this concentrator contains a triangular channel with an outer surface covered with photovoltaic cells and thermoelectric modules with a specific arrangement so that in addition to absorbing heat, a larger portion of the solar radiation is directly converted to electricity. Hence, the performance of...
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...
Experimental Investigation of PVT System Combined with Thermoelectric Module
, M.Sc. Thesis Sharif University of Technology ; shafii, Behshad (Supervisor) ; Saboohi, Yadollah (Supervisor)
Abstract
Photovoltaic phenomena is the base of Photovoltaic cells technology that can transform the solar insolation to electricity directly. In this transformation, the solar insolation intensity is the important factor to increase the performance of the Photovoltaic cells but one of the biggest barriers in the extension way of this technology is its more cost that need to be decrease. Concentration of solar radiation method is the best way to increase the performance of Photovoltaic systems and decrease its initial cost. At this project a novel structure of solar parabolic through concentrator is investigated experimentally and analytically. The usage of Thermoelectric module with Photovoltaic...
Reliable source transmission over relay networks with side information
, Article 2009 IEEE International Symposium on Information Theory, ISIT 2009, Seoul, 28 June 2009 through 3 July 2009 ; 2009 , Pages 699-703 ; 21578102 (ISSN); 9781424443130 (ISBN) ; Akhbari, B ; Mohsenzadeh, V ; Aref, M. R ; Sharif University of Technology
2009
Abstract
In this paper, we consider reliable transmission of a discrete memoryless source over multi-relay networks with correlated Side Information (SI) available at the relay nodes and the final receiver. We obtain a necessary condition for reliable source transmission over a multi-terminal network with SI, which results in a necessary condition for a multi-relay network with SI, as a special case. We also propose a separate source-channel coding scheme, and based on it, a sufficient condition for a multi-relay network with SI is derived. Based on a partitioning method and the nature of a degraded relay network, we propose another coding scheme which results in a sufficient condition for a degraded...
Image Steganography Resistant Against Higher Order statistical Attacks
, M.Sc. Thesis Sharif University of Technology ; Ghaemmaghami, Shahrokh (Supervisor) ; Mohajeri, Javad (Supervisor)
Abstract
A major goal in image steganography is to preserve the statistical properties of the host image to thwart statistical based steganalysis. However, most steganography methods introduce some distortions into the host signal’s statistical properties that have been used, as a certain indication of manipulation of the signal, by steganalysis algorithms. In order to overcome such a methodical vulnerability, a new generation of data hiding algorithms has been proposed in the literature to preserve histogram of the host signal. In this thesis we present a novel image steganographic technique to preserve one-dimensional and two-dimensional histograms of the host image. Experimental results show that...
Analytical model of the electro-mechanical impedance response of frame structures with L-shaped beams
, Article Research in Nondestructive Evaluation ; Volume 31, Issue 3 , 2 January , 2020 , Pages 187-202 ; Hamzeloo, S. R ; Barzegar, M ; Pourkamali Anaraki, A ; Sharif University of Technology
Taylor and Francis Inc
2020
Abstract
The electro-mechanical impedance (EMI) method has been accepted as an effective technique for detecting damages in the Structural health monitoring (SHM). EMI at any point of the structure depends on material properties, geometry and boundary conditions that all appears in dynamic stiffness of the structure. In spite of the expensive experimental methods for measuring the mechanical impedance, or the cheaper one electromechanical impedance, of structures, various analytical methods could be substitutions for them. In this paper, an analytical method is developed to obtain the EMI response of L-shaped beams through calculating the dynamic stiffness of the structure. To verify the model, an...
Microwave-assisted aminomethylation of electron-rich compounds under solvent-free condition
, Article Synthetic Communications ; Volume 30, Issue 1 , 2000 , Pages 69-72 ; 00397911 (ISSN) ; Sharifi, A ; Mohsenzadeh, F ; Saidi, M. R ; Sharif University of Technology
Marcel Dekker Inc
2000
Abstract
Electron-rich aromatic compounds react with formaldehyde and a secondary amine under solvent-free condition, in the presence of acidic alumina in a commercial microwave oven or at room temperature to produce aminomethylated products in good to excellent yields
Essays on Urban and Housing Economics
, Ph.D. Dissertation Sharif University of Technology ; Vesal, Mohammad (Supervisor) ; Mohsenzadeh Kermani, Amir (Supervisor)
Abstract
The challenges of urbanization have been the focus of researchers since the past. With the expansion of urbanization and massive migration of people from villages to cities, these challenges became more important in our country. These issues, which exist in many other countries in a serious manner, are discussed in the branch of urban economy in the world. This thesis is arranged in three chapters, in each of which one of the aspects related to urban economy and housing is discussed. In the first chapter, the effects of the construction of Mehr housing on the value of nearby residential properties are investigated using difference-in-difference method. It is shown that the construction of...