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Design of Plasmonic Systems for Nanobiophotonic Applications
, Ph.D. Dissertation Sharif University of Technology ; Rashidian, Bizhan (Supervisor) ; Vosoughi, Manouchehr (Supervisor) ; Shahrokhian, Saeed (Co-Advisor)
Abstract
In this thesis periodic plasmonic nanostructures are studied for detection of biological specious. The behavior of metal nanostructure arrays under normal incidence has been widely reported. However, simulation of periodic dispersive structures under oblique incidence requires newer formulations. Formulations, and algorithms based on modified split-field finite-difference time-domain (SF-FDTD) method are introduced, permitting analysis of metallic nanostructures arrays under oblique incidence. These novel algorithms are practically implemented on a parallel processing system based on graphics processing unit (GPU). Test and verification of these formulations are done by analyzing referenced...
Analytical Approaches for Soft Error Rate Estimation of Digital Circuits and Circuit Level
, M.Sc. Thesis Sharif University of Technology ; Miremadi, Ghasem (Supervisor)
Abstract
The aggressive device scaling and exponential increase in transistor counts on a chip have increasingly made the modern integrated circuits more susceptible to soft errors. Soft errors are caused by strikes from energetic particles such as neutrons and alpha particles. These errors are making a significant impact in the microelectronics industry. An essential step to design a highly reliable digital system with minimal performance and power penalty is Soft Error Rate (SER) estimation of system components.We propose a very fast and accurate analytical approach to estimate the overall SER and to identify the most vulnerable gates, flip-flops, and paths of a circuit. Our proposed approach fully...
Analysis and Design of Nanoantenna Arrays
, M.Sc. Thesis Sharif University of Technology ; Akbari, Mahmood (Supervisor)
Abstract
If the size of the conventional telecommunication antennas -that are widely used in transmitting broadcasted radio and TV messages- is reduced by a nanometer size these antennas can be used at optical frequencies. Dimensions of these optical nanoantennas -that made of nanoparticles with highly permittivity- can be smaller than half of the wavelength. Based on this capability, optical nanoantennas have some important applications such as optical communication, photovoltaic devices, non-classical light, and optical sensing. After studying on optical nanoantennas and their features, in this project, we present distinctions between optical NAs and MW antennas and then investigate about different...
Design of Plasmonic Nanostructures for Improving the Detection in Raman Spectroscopy
, Ph.D. Dissertation Sharif University of Technology ; Rashidian, Bizhan (Supervisor) ; Shahmansouri, Afsaneh (Co-Advisor)
Abstract
Excitation of Localized Surface Plasmons, which is one of the features of the metal nanostructures, results in the confinement of light in the dimensions smaller than the incidence wavelength, and even lower than the fundamental diffraction limit. This property causes electric field enhancement at surface, helping the occurrence of Surface Enhanced Raman Scattering (SERS). The amount of electric field enhancement and its resonance frequency depend on the type of material, its geometrical properties and its shape, and the arrangement of the scattering particles. Also, properties of surrounding environment material and the type of the excited mode of the structure, and the incidence wave...
Fabrication and Characterization of Novel Metallic Nanostructured Substrates for Surface-Enhanced Raman Scattering
, M.Sc. Thesis Sharif University of Technology ; Hormozi Nezhad, Mohammad Reza (Supervisor)
Abstract
Noble metallic nanostructures based on their localized surface plasmon resonance (LSPR) exhibit a phenomenon known as surface-enhanced Raman scattering (SERS) in which the scattering cross sections are dramatically enhanced for molecules adsorbed thereon. The enhancement factor (EF) in typical cases can reach 106 and in recent years, it has been reported that even single-molecule spectroscopy is possible by SERS, suggesting that the EF can be as much as 1014-1015. In this study, we report a simple method to synthesize nanostructures of Ag and Au on metallic wafers and semiconductor via electroless deposition method. This approaches has been demonstrated to deposit metal nanostructures, thin...
A data modem for GSM adaptive multi rate voice channel
, Article Proceedings of IEEE East-West Design and Test Symposium, EWDTS 2013 ; 2013 ; 9781479920969 (ISBN) ; Hadavi, A. H ; Kazemi, R ; Behnia, F ; Sharif University of Technology
2013
Abstract
This paper considers the problem of digital data transmission through the Global System for Mobile communications (GSM). A data modem is presented that utilizes codebooks of Speech-Like (SL) symbols to transmit data through the GSM Adaptive Multi Rate (AMR) voice codec. Using this codebook of finite alphabet, the continuous vocoder channel is modeled by a Discrete Memory less Channel (DMC). A heuristic optimization algorithm is proposed to select codebook symbols from a database of observed human speech such that the capacity of DMC is maximized. Simulation results show that the proposed data modem achieves higher data rates and lower symbol error rates compared to previously reported...
Power allocation and performance analysis for incremental-selective decode-and-forward cooperative communications over Nakagami-m fading channels
, Article IEICE Transactions on Communications ; Volume E96-B, Issue 6 , 2013 , Pages 1531-1539 ; 09168516 (ISSN) ; Saadat, R ; Aref, M. R ; Sharif University of Technology
2013
Abstract
The focus of this study is the performance of the relaying network with incremental selective decode-and-forward (ISDF) protocol in non-selective slow Nakagami-m fading channels. To enhance bandwidth efficiency, when the direct transmission is not successful the relay is used to retransmit a clean copy of the source signal. The proposed protocol achieves a significant reduction in the power consumption and an improvement in performance compared to the fixed decode-and-forward (DF). The exact symbol error rate (SER) of M-PSK modulation for the ISDF protocol over general fading channels is derived. However, as the exact SER analysis is very complicated, we provide an approximated SER...
Thorough tuning of the aspect ratio of gold nanorods using response surface methodology
, Article Analytica Chimica Acta ; Volume 779 , 2013 , Pages 14-21 ; 00032670 (ISSN) ; Robatjazi, H ; Jalali Heravi, M ; Sharif University of Technology
2013
Abstract
In the present work a central composite design based on response surface methodology (RSM) is employed for fine tuning of the aspect ratios of seed-mediated synthesized gold nanorods (GNRs). The relations between the affecting parameters, including ratio of l-ascorbic acid to Au3+ ions, concentrations of silver nitrate, CTAB, and CTAB-capped gold seeds, were explored using a RSM model. It is observed that the effect of each parameter on the aspect ratio of developing nanorods highly depends on the value of the other parameters. The concentrations of silver ions, ascorbic acid and seeds are found to have a high contribution in controlling the aspect ratios of NRs. The optimized parameters led...
Secure data communication through GSM Adaptive Multi Rate voice channel
, Article 2012 6th International Symposium on Telecommunications, IST 2012 ; 2012 , Pages 1021-1026 ; 9781467320733 (ISBN) ; Hadavi, A. H ; Kazemi, R ; Behnia, F ; Sharif University of Technology
2012
Abstract
This paper considers the problem of digital data transmission through the Global System for Mobile communications (GSM) for security applications. A data modem is presented that utilizes codebooks of Speech-Like (SL) symbols to transmit data through the GSM Adaptive Multi Rate (AMR) voice codec. Using this codebook of finite alphabet, the continuous vocoder channel is modeled by a Discrete Memory less Channel (DMC). A heuristic optimization algorithm is proposed to select codebook symbols from a database of observed human speech such that the capacity of DMC is maximized. Using the DMC capacity, a lower bound on the capacity of the considered voice channel can be achived. Simulation results...
Human cardiac troponin i sensor based on silver nanoparticle doped microsphere resonator
, Article Journal of Optics (United Kingdom) ; Volume 14, Issue 12 , 2012 ; 20408978 (ISSN) ; Bahrampour, A ; Zandi, M. H ; Sharif University of Technology
Abstract
Human cardiac troponin I (cTnI) is a specific biomarker for diagnosis of acute myocardial infarction (AMI). In this paper, a composite sensing system of an optical microsphere resonator and silver nanoparticles based on surface enhanced Raman scattering (SERS) and stimulated Raman scattering (SRS) techniques towards a point of care diagnostic system for AMI using the cTnI biomarker in HEPES buffered solution (HBS) is proposed. Pump and Raman signals enter the optical fiber coupling into the microsphere, and then SRS occurs in the microsphere. The presence of silver nanoparticles on the microsphere surface provides a tremendous enhancement of the resulting Raman signal through an...
Symbol error rate analysis and power allocation for decode and forward relaying with channel estimation error
, Article 2012 19th International Conference on Telecommunications, , 23 April 2012 through 25 April 2012, Jounieh ; 2012 ; 9781467307475 (ISBN) ; Pakravan, M. R ; Sharif University of Technology
IEEE
2012
Abstract
In this paper we study the statistical properties of the Signal to Noise Ratio (SNR) of the dual-hop relaying link in a cooperative wireless communication system in the presence of channel estimation errors for Decode and Forward (DF) relaying protocol. Then for assessment of the system performance the Symbol Error Rate (SER) is considered. Two approaches are introduced for SER calculation from which the second one results in a closed form solution. Finally the second approach is used to find an optimum power allocation scheme for transmission of pilot and data symbols at the source and the relay terminals that results in minimizing the SER and considerable amount of power saving. Also Monte...
Efficient algorithms to accurately compute derating factors of digital circuits
, Article Microelectronics Reliability ; Volume 52, Issue 6 , June , 2012 , Pages 1215-1226 ; 00262714 (ISSN) ; Tahoori, M. B ; Fazeli, M ; Miremadi, S. G ; Sharif University of Technology
2012
Abstract
Fast, accurate, and detailed Soft Error Rate (SER) estimation of digital circuits is essential for cost-efficient reliable design. A major step to accurately estimate a circuit SER is the computation of failure probability, which requires the computation of three derating factors, namely logical, electrical, and timing derating. The unified treatment of these derating factors is crucial to obtain accurate failure probability. Existing SER estimation techniques are either unscalable to large circuits or inaccurate due to lack of unified treatment of all derating factors. In this paper, we present fast and efficient algorithms to estimate SERs of circuit components in the presence of single...
Compute-and-forward two-way relaying
, Article IET Communications ; Volume 9, Issue 4 , 2015 , Pages 451-459 ; 17518628 (ISSN) ; Hejazi, M ; Nasiri Kenari, M ; Sharif University of Technology
Institution of Engineering and Technology
2015
Abstract
In this study, a new two-way relaying scheme based on compute-and-forward (CMF) framework and relay selection strategies is proposed, which provides a higher throughput than the conventional two-way relaying schemes. Two cases of relays with or without feedback transmission capability are considered. An upper bound on the computation rate of each relay is derived, and based on that, a lower bound on the outage probability of the system is presented assuming block Rayleigh fading channels. Numerical results show that while the average sum rate of the system without feedback, named as max-CMF (M-CMF), reaches the derived upper bound only in low SNRs, that of the system with feedback, named as...
Efficient codebook design for digital communication through compressed voice channels
, Article IET Communications ; Volume 10, Issue 18 , 2016 , Pages 2613-2620 ; 17518628 (ISSN) ; Behnia, F ; Sharif University of Technology
Institution of Engineering and Technology
2016
Abstract
The common voice channels existing in cellular communication networks provide reliable, ubiquitously available and top priority communication mediums. These properties make voice dedicated channels an ideal choice for high priority, real time communication. However, such channels include voice codecs that hamper the data flow by compressing the waveforms prior to transmission. This study designs codebooks of speech-like symbols for reliable data transfer through the voice channel of cellular networks. An efficient algorithm is proposed to select proper codebook symbols from a database of natural speech to optimise a desired objective. Two variants of this codebook optimisation algorithm are...
Fabrication of self-organized precisely tunable plasmonic SERS substrates via glancing angle deposition
, Article Physica Status Solidi (A) Applications and Materials Science ; Volume 214, Issue 9 , 2017 ; 18626300 (ISSN) ; Ualibek, O ; Bulfin, B ; Sugurbekova, G ; Duesberg, G. S ; Shvets, I ; Sharif University of Technology
Abstract
Plasmonic nanostructures offer great enhancement of the Raman signal due to the strong confinement of the electromagnetic field. Thus, they are considered as suitable candidates for surface enhanced Raman spectroscopy (SERS). In this work, we present an alternative fabrication route, called the glancing angle deposition (GLAD), for tunable fabrication of plasmonic self-organized Ag nanoparticle arrays aimed at SERS. Using the GLAD technique, the inter-particle distance within the arrays can be made as small as 1 nm. Moreover, the plasmonic resonance can be precisely tuned over the whole visible range. The GLAD method can be up-scaled; and when a transparent substrate is used, it enables...
Node positioning and lifetime optimization for wireless body area networks
, Article IEEE Sensors Journal ; Volume 17, Issue 14 , 2017 , Pages 4647-4660 ; 1530437X (ISSN) ; Jahed, M ; Sharif University of Technology
Abstract
Wireless communication networks may be categorized based on the extent of the geographical area that they cover. The latest trend in this assortment is wireless body area network (WBAN), which is standardized by IEEE 802.15.6 and is defined as a network composed of intelligent, miniaturized, low-power nodes that are implanted in, placed on, or in close proximity to the human body for certain healthcare applications. In this paper, we will start with some assessments on applicable channel models for a typical WBAN. Considering various scenarios with different carrier frequencies, bandwidths, body movements, and transceiver locations, the well-known Bayesian Information Criterion is used to...
Constrained error rate analysis for wireless body area networks
, Article IET Wireless Sensor Systems ; Volume 9, Issue 6 , 2019 , Pages 366-374 ; 20436386 (ISSN) ; Jahed, M ; Sharif University of Technology
Institution of Engineering and Technology
2019
Abstract
Wireless body area network (WBAN) is composed of miniaturised sensors that operate in the vicinity of the human body for recording the vital physiological signals and wirelessly transmitting them to a central hub for further processing. In this study, a statistical approach is applied to an experimental channel data set to extract the models for the squared channel gain that best describe the characteristics of the transmission medium between the sensors and the central hub. The derived models are then utilised to investigate the error rate performance of WBAN sensors. On the basis thereof, an optimisation problem is formed for which the cost function is the symbol error rate (SER) metric....
Chaperones promote remarkable solubilization of salmonella enterica serovar enteritidis flagellin expressed in escherichia coli
, Article Protein and Peptide Letters ; Volume 27, Issue 3 , 2020 , Pages 210-218 ; Sadeghi, Z ; Tarahomjoo, S ; Yaghmaie, S ; Sharif University of Technology
Bentham Science Publishers
2020
Abstract
Background: Flagellin of Salmonella enterica serovar Enteritidis (SEF) stimulates immune responses to both itself and coapplied antigens. It is therefore used in vaccine development and immunotherapy. Removal of pathogenic S. enterica ser. Enteritidis from SEF production process is advantageous due to the process safety improvement. The protein solubility analysis using SDS-PAGE indicated that 53.49% of SEF expressed in Escherichia coli formed inclusion bodies. However, the protein recovery from inclusion bodies requires a complex process with a low yield. Objective: We thus aim to study possibility of enhancing SEF expression in E. coli in soluble form using chemical and molecular...
Theoretical simulation of surface-enhanced resonance Raman spectroscopy of cytosine and its tautomers
, Article Journal of Raman Spectroscopy ; Volume 51, Issue 1 , 2020 , Pages 55-65 ; Mohammadpour, M ; Ramazani, S ; Jamshidi, Z ; Sharif University of Technology
John Wiley and Sons Ltd
2020
Abstract
The primary challenge of spectroscopic techniques in selective detection and characterization of tautomeric structures of DNA and RNA bases, and moreover, the accurate interpretation and explanation of the experimental results are the main motives of theoretical studies. Surface-enhanced Raman spectroscopy (SERS) can be a powerful approach to distinguish cytosine in the presence of its tautomers. For this respect, herein, the theoretical simulation of the SERS spectra of cytosine and its three most stable tautomers adsorbed on silver clusters is carried out. The calculations of SERS spectra is based on the excited-state energy gradient approximation as a well-established approach that gives...
Modified joint channel-and-data estimation for one-bit massive MIMO
, Article 53rd IEEE International Symposium on Circuits and Systems, ISCAS 2021, 22 May 2021 through 28 May 2021 ; Volume 2021-May , 2021 ; 02714310 (ISSN); 9781728192017 (ISBN) ; Rasoulinezhad, Ramin ; Amiri, M ; Gilani, F ; Saadatnejad, S ; Nezamalhosseini, A. R ; Shabany, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2021
Abstract
Centralized and cloud computing-based network architectures are the promising tracks of future communication systems where a large scale compute power can be virtualized for various algorithms. These architectures rely on high-performance communication links between the base stations and the central computing systems. On the other hand, massive Multiple-Input Multiple-Output (MIMO) technology is a promising solution for base stations toward higher spectral efficiency. To reduce system complexity and energy consumption, 1-bit analog-to-digital converters (ADCs) are leveraged with the cost of lowering the signal quality. To recover the lost information, more sophisticated algorithms, like...