Analyzing the Interplay of Power Management and Communication Reliability of Wireless Networks in Embedded Applications

, M.Sc. Thesis Sharif University of Technology Hosseini, Elahe Sadat (Author) ; Ejlali, Alireza (Supervisor)

Abstract

Due to safety critical applications of the embedded systems, reliability is one of the most important properties of these systems. Wireless networks also have error prone data transmission channels and limited power consumption. Therefore reliability and power conservation are two vital characteristics of the wireless network especially in embedded applications. Since achieving to a desirable level of data reliability is power consuming, we must consider a trade-off between power consumption and data reliability. In wireless networks power consumption can be categorized into: power consumption in wireless devices and power consumption in data transmission. For decrement of wireless devices...

Confidential Access to the Outsourced Relational Data

, M.Sc. Thesis Sharif University of Technology NajmAbadi, Elahe Sadat (Author) ; Jalili, Rasool (Supervisor)

Abstract

In recent years, there has been a trend toward outsourcing data to the cloud provider. These companies must tackle the data security challenges. Generally these parties are assumed to be honest but curious. In past years, the research communities have been investigating different solution to ensure confidentiality.
In addition to data confidentiality access and pattern confidentiality is a high-priority issue in some cases so. potential adversary should be unable to drive information from the observed access pattern to the outsourced data. Despite the fact that there are more investigation in the field of data confidentiality, concern over data security are the rise in outsourcing data,...

Circuit Model for Periodic Plasmonic Nanostructures Used as Light-rapping Back-structures in thin Film Solar Cells

, M.Sc. Thesis Sharif University of Technology Yarmoghaddam, Elahe (Author) ; Mehrany, Khashayar (Supervisor) ; Khavasi, Amin (Co-Advisor)

Abstract

In recent years, thin-film photovoltaic cells with thicknesses of less than 1-2 µm have been developed with potentially lower production costs. Due to the small thickness of the absorbing semiconductor in these cells, the absorption is inevitably low at energies close to the electronic band gap of the semiconductor. This is particularly a problem for thin-film devices. Recently، periodic metallic nanostructures supporting surface plasmons have been introduced as alternative solutions to achieve light trapping in thin-film solar cells.Full numerical methods are usually used for the analysis of these periodic structures. The main drawback of these methods is that they are time-consuming and...

Circuit model for periodic array of slits with multiple propagating diffracted orders

, Article IEEE Transactions on Antennas and Propagation ; Vol. 62, Issue 8 , August , 2014 , pp. 4041-4048 ; ISSN: 0018-926X Yarmoghaddam, E ; Shirmanesh, G. K ; Khavasi, A ; Mehrany, K ; Sharif University of Technology

2014

Abstract

We propose an analytical circuit model for accurate analysis of one-dimensional periodic array of metallic strips. The proposed model is valid not only in subwavelength regime, but also for wavelengths shorter than the period of structure. The working frequency can reach the visible range and thus electromagnetic properties of periodic arrays of nano-slits can be analyzed by the proposed model. The proposed model remains valid for arbitrary incident angles even when nonspecular diffracted orders become propagating. Analytical expressions are derived explicitly in order to describe the parameters of the proposed circuit model. The circuit model is derived by assuming that only one guided mode...

Erratum: Circuit model in design of THZ transparent electrodes based on two-dimensional arrays of metallic square holes (IEEE transactions on terahertz science and technology (2014) 4:3 (383-390))

, Article IEEE Transactions on Terahertz Science and Technology ; Volume 5, Issue 4 , June , 2015 , Pages 655-656 ; 2156342X (ISSN) Khavasi, A ; Mehrany, K ; Shirmanesh, G. K ; Yarmoghaddam, E ; Sharif University of Technology

IEEE Microwave Theory and Techniques Society 2015

Abstract

A circuit model has been proposed for two-dimensional metallic arrays of metallic square holes located on a homogeneous substrate. Although the proposed circuit model holds true, the surface admittance between the metallic hole array and the cover was erroneously calculated since the presence of the cross-polarization terms had been neglected. Furthermore, there have been mistakes in numerical simulation and in analytical calculations based on the presented formulas. The correct formulation is now given, and erroneous figures are replotted

Centrality-based group formation in group recommender systems

, Article 26th International World Wide Web Conference, WWW 2017 Companion, 3 April 2017 through 7 April 2017 ; 2019 , Pages 1187-1196 ; 9781450349147 (ISBN) Mahyar, H ; Khalili, S ; Elahe Ghalebi, K ; Grosu, R ; Mojde Morshedi, S ; Movaghar, A ; Sharif University of Technology

International World Wide Web Conferences Steering Committee 2019

Abstract

Recommender Systems have become an attractive field within the recent decade because they facilitate users' selection process within limited time. Conventional recommender systems have proposed numerous methods focusing on recommendations to individual users. Recently, due to a significant increase in the number of users, studies in this field have shifted to properly identify groups of people with similar preferences and provide a list of recommendations for each group. Offering a recommendations list to each individual requires significant computational cost and it is therefore often not efficient. So far, most of the studies impose four restrictive assumptions: (1) limited number of...

Investigate Laboratory Production of Hydroxyurea

, M.Sc. Thesis Sharif University of Technology Nejati, Poorya (Author) ; Bastani, Dariush (Supervisor) ; Seifkordi, Ali Akbar (Supervisor) ; Zegordi, Elahe (Co-Advisor)

Abstract

Hydroxyurea is an anticancer drug that is commonly used to treat chronic myeloid leukemia (white blood cell cancer in bone marrow), polycythemia vera (red blood cell cancer), sickle cell anemia, solid tumors, and in particular leukemia. In this research, in addition to analyzing all available methods for synthesis of hydroxyurea, the most economical method for synthesis of hydroxyurea which is Hantzsch method was chosen; then we synthesized hydroxyurea crystals using a precipitation or crystallization process. To do so, two hydroxylamine hydrochloride and potassium cyanate reactants have been used in the semi batch reactor. Since the reaction efficiency and purity of the synthesized...