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    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,... 

    Hybrid multiwalled carbon nanotubes and trioxide tungsten nanoparticles for hydrogen gas sensing

    , Article Journal of Physics D: Applied Physics ; Volume 42, Issue 16 , 2009 ; 00223727 (ISSN) Ghasempour, R ; Iraji zad, A ; Sharif University of Technology
    2009
    Abstract
    The WO3/multiwalled carbon nanotubes (MWNTs) hybrid films were fabricated by spin-coating on an alumina substrate. The structure, morphology, chemical composition and quality of the as-prepared WO3 nanoparticles, functionalized MWNTs and WO3/MWNTs hybrid films were studied by SEM, TEM, XRD, XPS, DLS and Raman spectroscopy methods. Results show that WO3 nanoparticles were nucleated on oxygenated functionalized MWNTs in hybrid suspension. After coating and annealing the films at 350 °C, the hybrid WO3/MWNTs films present rather linear gas sensitivity as a function of hydrogen concentrations at 300 °C. Results are discussed based on surface increase as well as development of two types of... 

    Agile web development methodologies: a survey and evaluation

    , Article Studies in Computational Intelligence ; Volume 722 , 2018 , Pages 1-25 ; 1860949X (ISSN) Ghasempour Maleki, N ; Ramsin, R ; Sharif University of Technology
    Springer Verlag  2018
    Abstract
    Dynamic and accessible web systems have gained utmost importance in modern life. Due to the competitive nature of such systems, they need to be superior as to performance, scalability, and security. Web systems typically require short time-to-markets, and it should be possible to easily implement new requirements into working web systems. These ideals have made agile methods especially suitable for developing such systems, as they promote productivity, facilitate continuous interaction with customers, and enhance the flexibility and quality of the software produced. When starting a web development project, selecting the methodology that fits the project situation can be an important factor... 

    Safe Personalized Treatment Recommendation System for Multimorbidity

    , M.Sc. Thesis Sharif University of Technology Ghasempour, Elahe (Author) ; Habibi, Jafar (Supervisor)
    Abstract
    Multimorbidity in an individual is a typical and increasing condition and a major challenge in healthcare. The goal of treatment recommendation for such patients is to decide the most effective combination of treatments. Doctors typically prescribe medication based on their intuition and experience. However, due to knowledge gaps or unintended biases, often times these clinical decisions can be sub-optimal. Broad adoption and usage of electronic health records (EHRs) in the last decade has opened up a great opportunity to leverage healthcare data to improve clinical decisions.In this approach we use EHR and drug-drug interaction (DDI) information to prescribe medications. We use multiple... 

    Design and Implementation of a Watchdog Processor using BMC for Remote Reliability Management

    , M.Sc. Thesis Sharif University of Technology Ghasempour, Amin (Author) ; Ejlali, Alireza (Supervisor)
    Abstract
    Predictive Maintenance (PdM) plays a pivotal role in ensuring the continuous operation and reducing the operational costs of computer servers. The success of this strategy is directly contingent upon the integrity and accuracy of hardware sensor data. The emergence of faults within these sensors provides erroneous information, thereby undermining the integrity of PdM systems. This can lead to costly, unnecessary maintenance decisions or, conversely, the oversight of impending failures. This research introduces a novel, purely software-based solution for concurrent fault detection in server sensors. By intelligently leveraging the Baseboard Management Controller (BMC) as a watchdog processor,... 

    Evaluation the Surface Settlement and Interaction Between Tunnelinline2 and Metro Station Inline1 of Mashhad Metro at Intersection Using 3-D Numerical Modeling

    , M.Sc. Thesis Sharif University of Technology Ghasempour, Hamid (Author) ; Sadaghiani, Mohammad Hossein (Supervisor)
    Abstract
    In this study, the interaction of tunneling of line 2 of Mashhad metro and existing metro station (Shariati station) in line 1 has been investigated. To produce the stress and displacement which is caused by excavation of station, the process of station excavation has been modeled by method of cut and cover.This method is the common method for station construction at Shallow depth and is used in several cases in line 1 of Mashhad metro. The piled-raft system is used in foundation of central part of the station to reduce the settlements and the effects of interactions between the station and new tunnel. The new tunnel under the station is surrounded by two rows of lateral piles with distance... 

    Approximation Approaches for Ontology Alignment

    , M.Sc. Thesis Sharif University of Technology Ghasempour, Rouhollah (Author) ; Abolhassani, Hassan (Supervisor)
    Abstract
    Ontology alignment is a process for selection of a good mapping between entities of two (or more) ontologies. It can be viewed as a two phase process of: 1) Find the similarity of each pair of entities from two ontologies, and 2) Extraction of an optimal or near optimal mapping. Many researches had been down in the first phase, but researches in the second phase are little. Mapping extraction approaches applied in ontology alignment use similarity matrix to extract mapping, and ontologies have not any role in mapping extraction phase. One of the most important components in ontology is its structure which can help us in alignment extraction.
    In this thesis, an approach was proposed that... 

    The moment method for fiber raman amplifier gain ripple minimization

    , Article Optics Communications ; Volume 281, Issue 14 , 2008 , Pages 3673-3680 ; 00304018 (ISSN) Bahrampour, A. R ; Farman, F ; Ghasempour, A ; Sharif University of Technology
    2008
    Abstract
    We aim to propose a novel fiber Raman amplifier modeling based on the moment method, which is previously introduced for modeling the inhomogeneous Erbium doped fiber amplifiers and recently employed to analyze the fiber Raman amplifier with continuous pump spectrum. In this model, the number of governing equations is independent of the number of signals and according to the degree of accuracy it is proportional to the number of pumps. This method is employed to analyze the Raman fiber amplifiers with an arbitrary input signal line shape and to minimize the gain ripple of the fiber Raman amplifier with respect to the pump powers and pump frequencies. © 2008 Elsevier B.V. All rights reserved  

    Stochastic Cauchy Problem in UMD Banach Spaces

    , M.Sc. Thesis Sharif University of Technology Ghasempour, Mohammad (Author) ; Zohuri Zangeneh, Bijan (Supervisor)
    Abstract
    We discuss, in the setting of UMD Banach spaces E, existence, uniqueness and the continuous dependence on the data A, F, G and of mild solutions of semilinear stochastic evolution equations with multiplicative noise of the form dX(t) = [AX(t) + F(t;X(t))]dt + G(t;X(t))dWH(t); t 2 [0; T]; X(0) = ; Where A generates an analytic C0-semigroup on a UMD Banach space E and WH is a cylindrical Brownian motion with values in a Hilbert space H. We can see that if the mappings F : [0; T] E ! E and G : [0; T] E ! L(H;E) satisfy suitable Lipschitz conditions and is F0-measurable and bounded, then this problem has a unique mild solution.And We arw going to review continuous dependence of the solutions... 

    Investigating the Effect of Communication of the Family Nature of Business on the Organizational Reputation, Measuring the Mediating Role of Brand Equity and Corporate Social Responsibility

    , M.Sc. Thesis Sharif University of Technology Ghasempour, Dana (Author) ; Khalili Nasr, Arash (Supervisor)
    Abstract
    According to official statistics, family businesses form the majority of businesses around the world. When we talk about businesses, we are more likely to say that those firms face issues related to family businesses.One of the trending topics that has recently been considered by researchers and a lot of research has been done in this regard, is specific issues related to marketing and branding of family businesses.In this study, we tried to examine the family business brand in terms of reputation. Reputation is the perception in the minds of brand stakeholders about the brand and the organization. So we tried to take as fair and accurate a sample as possible, to seek the opinions of... 

    Csr Effect on Customer Loyalty during a Pandemic: a Case Study of Mobile-Phone Operator Companies in Iran

    , M.Sc. Thesis Sharif University of Technology Ghasempour Negati, Mobin (Author) ; Kiamehr, Mehdi (Supervisor)
    Abstract
    Customer loyalty plays one of the most vital roles in business profitability. This concept gives special prominence to attaining new customers, which is by far less costly than attracting new ones. Therefore, investigating the impact of factors affecting customer retention is of precise significance. In the respect, corporate social responsibility, as an imperative factor impacting customer loyalty, gained more attention by various companies in the last decades.Over the past few months, the world has encountered the hazard of the Coronavirus pandemic. Most aspects of daily life in different parts of the globe have been affected by this disease. Companies are no exception. The coronavirus has... 

    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... 

    Visible light photoinactivation of bacteria by tungsten oxide nanostructures formed on a tungsten foil

    , Article Applied Surface Science ; Volume 338 , May , 2015 , Pages 55-60 ; 01694332 (ISSN) Ghasempour, F ; Azimirad, R ; Amini, A ; Akhavan, O ; Sharif University of Technology
    Elsevier  2015
    Abstract
    Antibacterial activity of tungsten oxide nanorods/microrods were studied against Escherichia coli bacteria under visible light irradiation and in dark. A two-step annealing process at temperatures up to 390 °C and 400-800 °C was applied to synthesize the tungsten oxide nanorods/microrods on tungsten foils using KOH as a catalyst. Annealing the foils at 400 °C in the presence of catalyst resulted in formation of tungsten oxide nanorods (with diameters of 50-90 nm and crystalline phase of WO3) on surface of tungsten foils. By increasing the annealing temperature up to 800 °C, tungsten oxide microrods with K2W6O19 crystalline phase were formed on the foils. The WO3 nanorods showed a strong... 

    In pursuit of a replacement for conventional high-density polyethylene tubes in ground source heat pumps from their composites – a comparative study

    , Article Geothermics ; Volume 87 , September , 2020 Narei, H ; Fatehifar, M ; Ghasempour, R ; Noorollahi, Y ; Sharif University of Technology
    Elsevier Ltd  2020
    Abstract
    Ground-source heat pumps, as the most environmentally friendly and energy-efficient air conditioning technology, suffer from a great required length of ground heat exchanger, partly arising from the low thermal conductivity of high-density polyethylene tubes commonly used in ground heat exchangers. In an attempt to find a replacement with an acceptable thermal conductivity for high-density polyethylene tubes, in this study, first, a comprehensive comparative study on fillers commonly used in thermally conductive polymer composites and resulting high-density polyethylene composites was conducted. Then, based on the advantages and disadvantages presented, an appropriate composite was selected... 

    Tuning of random lasers by means of external magnetic fields based on the Voigt effect

    , Article Optics and Laser Technology ; Volume 47 , April , 2013 , Pages 121-126 ; 00303992 (ISSN) Ghasempour Ardakani, A ; Mahdavi, S. M ; Bahrampour, A. R ; Sharif University of Technology
    2013
    Abstract
    It has been proposed that emission spectrum of random lasers with magnetically active semiconductor constituents can be made tunable by external magnetic fields. By employing the FDTD method, the spectral intensity and spatial distribution of electric field are calculated in the presence of an external magnetic field. It is numerically shown that due to the magneto-optical Voigt effect, the emission spectrum of a semiconductor-based random laser can be made tunable by adjusting the external magnetic field. The effect of magnetic field on the localization length of the laser modes is investigated. It is also shown that the spatial distribution of electric field exhibited remarkable... 

    Design and fabrication of sensitive carbon nanotubes/PMMA film for acetone vapour detection

    , Article International Journal of Nanomanufacturing ; Volume 5, Issue 3-4 , 2010 , Pages 268-277 ; 17469392 (ISSN) Ghasempour, R ; Iraji Zad, A ; Hormozi Nezhad, M. R ; Sharif University of Technology
    2010
    Abstract
    We present gas sensing property of carbon nanotubes (CNTs) polymethylmethacrylate (PMMA) composite as the active element for acetone vapour detection at room temperature. The polymeric films were formed by spin coating method on SiO2 substrates. Then they were activated by dropping the CNTs suspension in acetone on the PMMA films. The CNT/PMMA films were characterised by SEM, TEM and Raman spectroscopy. Variation of film's electrical resistance after exposure polar and non-polar gases is utilised as the principle of gas sensing. The experimental results showed that the samples present chemical selectivity and reversibility toward polar gases especially acetone vapour  

    Pd doped WO3 films prepared by sol-gel process for hydrogen sensing

    , Article International Journal of Hydrogen Energy ; Volume 35, Issue 2 , 2010 , Pages 854-860 ; 03603199 (ISSN) Fardindoost, S ; Iraji zad, A ; Rahimi, F ; Ghasempour, R ; Sharif University of Technology
    2010
    Abstract
    The sol gel method was employed to prepare peroxopolytungstic acid (P-PTA). Palladium chloride salt was dissolved in the sol with different Pd:W molar ratios and coated on Al2O3 substrates by spin coating method. XRD and XPS techniques were used to analyze the crystal structure and chemical composition of the films before and after heat treatment at 500 °C. We observed that Pd can modify the growth kinetic of tungsten trioxide nanoparticles by reducing the crystallite size and as a result can improve hydrogen sensitivity. Resistance-sensing measurements indicated sensitivity of about 2.5 × 104 at room temperature in hydrogen concentration of 0.1% in air. Considering all sensing parameters,... 

    Numerical simulation of a concentrating photovoltaic-thermal solar system combined with thermoelectric modules by coupling Finite Volume and Monte Carlo Ray-Tracing methods

    , Article Energy Conversion and Management ; Volume 172 , 2018 , Pages 343-356 ; 01968904 (ISSN) Shadmehri, M ; Narei, H ; Ghasempour, R ; Shafii, M. B ; Sharif University of Technology
    Elsevier Ltd  2018
    Abstract
    During the last decades, the adoption of more strict safety and environmental regulations, as well as a rise in energy costs, sparked an increasing interest in the design of renewable energies systems, particularly solar systems, to supply both electrical power and heat. Because of their capability to simultaneously supply both electricity and heat, concentrating photovoltaic-thermal and thermoelectric hybrid systems have recently attracted scholarly attention. In this study, a detailed three-dimensional computational model of a novel concentrating photovoltaic-thermal solar system combined with thermoelectric modules in an integrated design with a triangular absorber and corresponding...