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emamy--zahra-sadat
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Characterizing an Environment from Visibility Information
, M.Sc. Thesis Sharif University of Technology ; Zarei, Alireze (Supervisor)
Abstract
Using visual information of an environment is the immediate way of detecting and identifying an unknown environment. These information maybe obtained using straight visibility detecting sensors. One of the formal models of these visual information is the visibility graph which have a vertex for each vertex (corner point) of the environment and two vertices have an edge whenever their corresponding corners see each other. Then, the problem is to characterize such a graph and reconstruct the target environment with equivalent visibility graph. Despite existence of plenty of research results, these are open problems in computational geometry and rigid results exist only for limited special...
Pseudo-triangulating a simple polygon from its visibility graph
, Article 2015 5th International Conference on Computer and Knowledge Engineering, ICCKE 2015, 29 October 2015 ; October , 2015 , Pages 106-111 ; 9781467392808 (ISBN) ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2015
Abstract
Visibility graph of a simple polygon in a plain is a graph in which the number of its vertices corresponds with the number of vertices in the polygon and each of its edges corresponds with a pair of visible vertices in the polygon. Visibility graph reconstruction of a polygon is one of the old and important problems in computational geometry for which no algorithm has been offered yet. Considering that the problem of visibility graph reconstruction of a pseudo-triangle has been solved, we present an O(n2)-time algorithm for pseudo-triangulation of a simple polygon, using the visibility graph corresponding with the polygon (n is number of vertices of the polygon). To do so, first we present a...
Synthesize of Graphene Nanoribbons with a Non-Zero Energy Band Gap for Inactivation of Alive Cells Using Infrared Irradiation
, M.Sc. Thesis Sharif University of Technology ; Akhavan, Omid (Supervisor)
Abstract
Graphene is a one layer atom thickness and zero energy gap so for using it in nano electronic and transistors baised on graphene it's energy gap should be opened.one of the methods for opening graphene band gap is creating nano scale boundaries or synthesize graphene nanoribbons. One of the new methods for graphene nanoribbon synthesize is longitudinal opening of carbon nanotube. In this thesis graphene nanoribbons synthesize with this method and analyze with AFM and Raman spectroscopy. Carbon nanotubes also have energy gap and IR absorption recently they used for living cell destruction. In this thesis we synthesize graphene nanoribbons and analyzing their optical absorption and use it for...
Nontoxic concentrations of PEGylated graphene nanoribbons for selective cancer cell imaging and photothermal therapy
, Article Journal of Materials Chemistry ; Volume 22, Issue 38 , 2012 , Pages 20626-20633 ; 09599428 (ISSN) ; Ghaderi, E ; Emamy, H ; Sharif University of Technology
2012
Abstract
Reduced graphene oxide nanoribbons functionalized by amphiphilic polyethylene glycol (rGONR-PEG) were applied to attach arginine-glycine-aspartic acid (RGD)-based peptide and cyanine dye 3 (cy3) for targeting ανβ3 integrin receptors on human glioblastoma cell line U87MG and its selective fluorescence imaging, respectively. The rGONR-PEG suspension with a concentration of 100 μg mL -1 showed ∼14 and 2.4-fold higher near infrared (NIR) absorption at 808 nm than GONR (with dimensions of ∼80 nm × 1 μm) and rGO-PEG sheets (with lateral dimensions of ∼2 μm), respectively. The rGONR-PEG-cy3-RGD exhibited highly efficient NIR photothermal therapy performance (concentrations ≥1.0 μg mL-1 resulted in...
Genotoxicity of graphene nanoribbons in human mesenchymal stem cells
, Article Carbon ; Volume 54 , 2013 , Pages 419-431 ; 00086223 (ISSN) ; Ghaderi, E ; Emamy, H ; Akhavan, F ; Sharif University of Technology
2013
Abstract
Single-layer reduced graphene oxide nanoribbons (rGONRs) were obtained through an oxidative unzipping of multi-walled carbon nanotubes and a subsequent deoxygenation by hydrazine and bovine serum albumin. Human mesenchymal stem cells (hMSCs) were isolated from umbilical cord blood and used for checking the concentration- and time-dependent cyto- and geno-toxic effects of the rGONRs and reduced graphene oxide sheets (rGOSs). The cell viability assay indicated significant cytotoxic effects of 10 μg/mL rGONRs after 1 h exposure time, while the rGOSs exhibited the same cytotoxicity at concentration of 100 μg/mL after 96 h. The oxidative stress was found as the main mechanism involved in the...
Investigation of the effect of Al-5Ti-1B grain refiner on dry sliding wear behavior of an Al-Zn-Mg-Cu alloy formed by strain-induced melt activation process
, Article Materials and Design ; Volume 46 , 2013 , Pages 766-775 ; 02641275 (ISSN) ; Aghdam, B. G ; Rahnoma, H. E ; Emamy, M ; Sharif University of Technology
2013
Abstract
This study was undertaken to investigate the influence of Al-5Ti-1B master alloy and modified strain-induced melt activation process on the structural characteristics, mechanical properties and dry sliding wear behavior of Al-12Zn-3Mg-2.5Cu aluminum alloy. The optimum amount of Ti containing master alloy for proper grain refining was selected as 2. wt.%. The alloy was produced by modified strain-induced melt activation (SIMA) process. Reheating condition to obtain a fine globular microstructure was optimized. The optimum temperature and time in strain-induced melt activation process are 575. °C and 20. min, respectively. T6 heat treatment was applied for all specimens before tensile testing....
Cluster-based adaptive SVM: a latent subdomains discovery method for domain adaptation problems
, Article Computer Vision and Image Understanding ; Volume 162 , 2017 , Pages 116-134 ; 10773142 (ISSN) ; Jamzad, M ; Sharif University of Technology
2017
Abstract
Machine learning algorithms often suffer from good generalization in testing domains especially when the training (source) and test (target) domains do not have similar distributions. To address this problem, several domain adaptation techniques have been proposed to improve the performance of the learning algorithms when they face accuracy degradation caused by the domain shift problem. In this paper, we focus on the non-homogeneous distributed target domains and propose a new latent subdomain discovery model to divide the target domain into subdomains while adapting them. It is expected that applying adaptation on subdomains increase the rate of detection in comparing with the situation...
Mesoporous silica nanoparticles (MCM-41) coated PEGylated chitosan as a pH-Responsive nanocarrier for triggered release of erythromycin [electronic resource]
, Article International Journal of Polymeric Materials and Polymeric Biomaterials ; 2014, Volume 63, Issue 13, Pages 692-697 ; Mazaheri Tehrani, Zahra ; Sharif University of Technology
Abstract
A pH-responsive drug delivery system based on core shell structure of mesoporous silica nanoparticle (MSN) and chitosan-PEG copolymer was prepared and characterized by Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), scanning electron microscope (SEM), and high-resolution transmission microscope (HR-TEM) techniques. In order to improve compatibility MSN and drug, mesoporous nanosilica was modified by 3-aminopropyl triethoxysilane. The release of erythromycin (a macrolide antibiotic) as a model drug was investigated in two pHs, 7.4 and 5.5
Indoor Noise Pollution Modeling: A Case Study on Resalat Tunnel
, M.Sc. Thesis Sharif University of Technology ; Vaziri, Manouchehr (Supervisor)
Abstract
Noise or noise pollution, is defined as an unwanted sound, produced mostly by motor vehicles in urban areas. If the noise exceeds its limit, adverse effects on users and citizens are expected. Thus the assessment of the noise level and its comparison with allowable values is mandatory. Traffic induced noise depends upon different factors such as traffic, weather, and, sound barriers. Noise pollution study has a long history all over the world. Many studies, mostly representing the outdoor noise pollution models, have been done in recent years. This paper presents an assessment of traffic-induced noise in a heavily traveled tunnel, locally referred to as Resalat tunnel, which is located in...
The Effect of Travel Time Reliability on Morning Peak Travellers route choice in Large Metropolitan Area
, M.Sc. Thesis Sharif University of Technology ; Poorzahedy, Hossein (Supervisor)
Abstract
Data collected from street networks show that travel time in urban street networks is a stochastic variable, whose range of variation increases with the congestion level. Work and school trips comprise the major part of morning peak volumes, whose common characteristic is that they need to be made on time. For this reason, these travelers are pessimistic in their route choice, and try to choose routes which are more reliable. Travel time standard deviation is one of the common measures for estimating travel time reliability that is related to properties of day-to-day travel time distribution on a particular route. Based on the empirical data collected from Tehran street network, this paper...
Design and Implementation of a FlexRay Transceiver
, M.Sc. Thesis Sharif University of Technology ; Atarodi, Mojtaba (Supervisor)
Abstract
With the advancement of automotive industry, the number of electronic systems that need to communicate with each other has increased. An effective strategy to meet these growing demands is using bus-based protocols, which can establish safe communication among numerous nodes with reasonable cost, weight, and space requirements. The objective of this thesis is the design and implementation of a transceiver based on the FlexRay protocol. The significance of this protocol lies in its ability to provide higher data transmission rates compared to other protocols like CAN and LIN, and its role as the foundational communication medium among various domains in modern vehicle architectures. In this...
Using Information Beyond Text to Generate Language Embedding Vectors
, M.Sc. Thesis Sharif University of Technology ; Sameti, Hossein (Supervisor)
Abstract
In this thesis, we introduce a novel Artificial Intelligence (AI) system inspired by the philosophical and psychoanalytical concept of imagination as a ``Re-construction of Experiences". Our AI system is equipped with an imagination-inspired module that bridges the gap between textual inputs and other modalities, enriching the derived information based on previously learned experiences. A unique feature of our system is its ability to formulate independent perceptions of inputs. This leads to unique interpretations of a concept that may differ from human interpretations but are equally valid, a phenomenon we term as ``Interpretable Misunderstanding". We employ large-scale models,...
Entanglement Distillation for Weakly Entangled States
, M.Sc. Thesis Sharif University of Technology ; Mirkamali, Maryam Sadat (Supervisor)
Abstract
Quantum entanglement is an essential resource in quantum information processing, such as quantum communication and quantum computing. Although entanglement is critical for practical implementations in these fields, creating and transmitting entanglement without altering the states is challenging. External noise may destroy or weaken the entanglement. Consequently, there is a need for methods to improve entanglement. Entanglement distillation is an effort to address this issue. It is a process where, probabilistically, a smaller number of strongly entangled states are created from a fixed number of noisy entangled states. This process is carried out using only local operations and classical...
Deformation and Annealing Behavior of an Austenitic Stainless Steel
, M.Sc. Thesis Sharif University of Technology ; Serajzadeh, Siamak (Supervisor)
Abstract
In this research, non-isothermal annealing process at temperatures ranging between 400°C to 830 °C was investigated in warm and cold-rolled austenitic stainless steel 304L. First, the wide variety of austenitic to martensitic structure was produced by the multi-pass rolling process at room temperature -8 °C, 200 °C, and 280°C. The n exponent in Olson-Cohen equation was governed 2.83 after non-linear curve fitting to assess the fraction of deformation-induced martensite as a function of strain. Afterward, Abaqus/Explicit method was utilized to achieve the stored energy and plastic strains distribution through the thickness. Then, Cellular automata and Galerkin-finite element models were...
Theoretical and Computational Investigation of Quantum Plasmonic Properties of Nanocluster Dimers
, M.Sc. Thesis Sharif University of Technology ; Jamshidi, Zahra (Supervisor)
Abstract
In today's era, metal nanoparticles play an important role in technologies emerging from different sciences, such as chemistry, physics, optics, material science, due to their unique characteristics. In the development of nanooptics science, it can be said that metal nanoparticles play an important role. The ability of conductive electrons collective oscillation causes surface charge density fluctuations in nanoparticles, this phenomenon is known as surface plasmons. Surface plasmons are surprisingly coupled with light and cause the significant increase in the intensity of optical fields induced in nanoparticles. Therefore, with the presence of localized surface plasmons or plasmon...
Theoretical Investigation of Ab-initio MD Approach to Increase the Efficiency and Accuracy of VCD Spectrum Calculation
, M.Sc. Thesis Sharif University of Technology ; Jamshidi, Zahra (Supervisor)
Abstract
Understanding of the Molecules is the main purpose of the chemistry. Ab-initio molecular dynamics (AIMD) as a branch of the computational chemistry, tries to give us a deep comprehension of the molecule, and its chemical, physical and optical activities. This comprehension, relies on the accuracy of quantum mechanics, in addition to the speed of the classical mechanics. The mixing of the quantum mechanics and the classical mechanics could simulate activities of the atoms in the time-domain, provided the mixing is done with precaution. This, in turn, helps us to forecast the response of a molecule in different situations, and also translating the macroscopic phenomena in a nanoscopic...
Investigation of Plasmonic Excitation in Carbonic Nanostructures Within Near-IR
, M.Sc. Thesis Sharif University of Technology ; Jamshidi, Zahra (Supervisor)
Abstract
To date, the plasmonic properties of many metallic and semi-conducting materials have been investigated and used in various industries. One of the plasmonic material categories that have always been considered is polycyclic aromatic hydrocarbon or PAH, whose plasmonic resonance energy depends on the charge state of the molecule. In this regard, it is easy to change the plasmonic resonance energy via changing the induced charge, which is a unique feature of the mentioned materials. In addition, plasmonic structures with excitations in the infrared region are able to enhance the vibration intensity of absorbed molecules by increasing the electric field around themselves. Therefore, they have...
Using Nonlinear Effects of Light for Optical Signal Processing
, M.Sc. Thesis Sharif University of Technology ; Kavehvash, Zahra (Supervisor)
Abstract
Ultrafast signal processing in time-domain with high resolution and reconfigura-bility is a challenging task. This paper, for the first time, introduces a time-varying metasurface consisting of graphene microribbon array for implementing time-lens in the terahertz domain. Given that the surface conductivity of graphene is proportional to the Fermi energy level in the THz regime, it is possible to change the phase property of the incident electromagnetic pulse by changing the Fermi level while the Fermi level itself is a function of voltage. Upon this fact, a quadratic temporal phase modulator, namely time-lens has been realized. This phase modulation is applied to the impinging signal in the...
Using Simulation-Optimization Approach for Fire Station Location and Vehicle Assignment Problem: a Case Study in Tehran, Iran
, M.Sc. Thesis Sharif University of Technology ; Amini, Zahra (Supervisor)
Abstract
In this research, the problem of locating fire stations and allocating equipment has been studied and a simulation-optimization approach has been presented to solve the problem. The mathematical models of this research were developed based on the idea of the randomness of the covered demand and the maximum expected coverage model. In these models, the issue of non-availability of equipment to cover accidents, the random nature of accidents, various fire incidents and the equipment needed to cover them are considered. Two mathematical models with deterministic and non-deterministic approach with different scenarios for demand are proposed. The non-deterministic model is developed with the aim...
Introducing An Integrated Framework For Solving The Fleet Planning Problem Using A Simulation-Optimization Approach
, M.Sc. Thesis Sharif University of Technology ; Amini, Zahra (Supervisor)
Abstract
One of the main concerns of industrial companies’ managers is providing an efficient logistics system. To achieve an efficient logistics system, the fleet planning problem is studied by many researchers in recent years. This problem consists of multiple sub-problems at three levels: operational, tactical, and strategic. These sub-problems are closely related to each other and need to be studied and addressed in an integrated manner. In this research, an attempt is made to provide an integrated framework to solve the vehicle routing problem (operational), outsourcing problem (tactical), and fleet composition problem (strategic). These problems have various uncertainties, including customer...