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An 8-bit current-mode folding ADC with optimized active averaging network
, Article Scientia Iranica ; Volume 15, Issue 2 , 2008 , Pages 151-159 ; 10263098 (ISSN) ; Sharif Bakhtiar, M ; Sharif University of Technology
Sharif University of Technology
2008
Abstract
In this paper, an 8-bit CMOS current-mode folding-interpolating ADC is presented. A new active averaging-interpolating network is described, which results in a better error correction factor compared to its resistive counterpart. Using novel circuits for fast settling and careful transistor sizing, a fast (>160 Msps) and low power (70 mW in 2.5 V supply voltage) 8-bit ADC, with a total chip area of 1 × 1.4 mm in a 0.25 micron CMOS process, is demonstrated. © Sharif University of Technology, April 2008
An 8-bit 160 MS/s folding-interpolating adc with optimizied active averaging/interpolating network
, Article IEEE International Symposium on Circuits and Systems 2005, ISCAS 2005, Kobe, 23 May 2005 through 26 May 2005 ; 2005 , Pages 6150-6153 ; 02714310 (ISSN) ; Movahedian, H ; Bakhtiar, M. S ; Sharif University of Technology
2005
Abstract
An 8-bit CMOS folding-interpolating analog-todigital converter is presented. A new method for designing optimized averaging circuit is also described. Careful circuit design and layout leads to a high-speed (160 MSPS) and low power (70 mW in 2.5 V supply voltage) ADC. The ADC is successfully implemented in 0.25um CMOS digital process and it takes 1x1.4 mm2 silicon area. © 2005 IEEE
An Online Portfolio Selection Algorithm Using Pattern-matching Principle
, M.Sc. Thesis Sharif University of Technology ; Khedmati, Majid (Supervisor)
Abstract
According to the rise of turnover and pace of trading, accelerating of analysis and making decision is unavoidable. Humans are unable to analyze big data quickly without behavioral biases so, using machines to analyze big data seems critical. Hence, financial markets tend to apply algorithmic trading in which some techniques like data mining and machine learning are notable. OLPS which sequentially allocates capital among a set of assets aiming to maximize the final return of investment in the long run, is the core problem in algorithmic trading. This article presents an online portfolio selection algorithm. The online portfolio selection sequentially selects a portfolio over a set of assets...
Taxing Auto Ownership and Use for Reduction of Urban Air Pollution
, M.Sc. Thesis Sharif University of Technology ; Poorzahedy, Hossein (Supervisor)
Abstract
The purpose of this study is to model the long-term effects of taxes on different aspects of private cars upon auto ownership and use, and thereby auto industries in producing more fit cars, so as to minimize auto emission. It involves used car market, different car demands and auto industry production. The study follows some previous studies in this area and tries to enhance the various aspects of the model by directing it toward a more real situation. In order to visualize the effects of the model, it has been applied on the case of Shiraz in 1378. It has been shown that the model was able to reduce air pollution and fuel consumption by 90% and 50%, respectively, as compared to the “Do...
The prediction of the density of undersaturated crude oil using multilayer feed-forward back-propagation perceptron
, Article Petroleum Science and Technology ; Volume 30, Issue 1 , 2011 , Pages 89-99 ; 10916466 (ISSN) ; Shahkarami, A ; Azin, R ; Sharif University of Technology
2011
Abstract
Crude oil density is an important thermodynamic property in simulation processes and design of equipment. Using laboratory methods to measure crude oil density is costly and time consuming; thus, predicting the density of crude oil using modeling is cost-effective. In this article, we develop a neural network-based model to predict the density of undersaturated crude oil. We compare our results with previous works and show that our method outperforms them
Study of the VAPEX process in fractured physical systems using different solvent mixtures
, Article Oil and Gas Science and Technology ; Volume 63, Issue 2 , 2008 , Pages 219-227 ; 12944475 (ISSN) ; Kharrat, R ; Vossoughi, S ; Ghotbi, C ; Sharif University of Technology
2008
Abstract
In this work, the vapour extraction (VAPEX) process is studied experimentally in a rectangular physical model at moderate-high pressure. The solvent was either pure propane or a mixture of propane/ methane with different compositions. The solvent and carrier gas were totally mixed before injection, so that a solvent with the desired composition flowed through the injector during experiments, and the solvent mixture was in thermodynamic equilibrium before injection into VAPEX cell. Effects of pressure and composition of solvent were studied. Results showed that at a fixed pressure, the process is more effective with pure solvent compared to the use of solvent mixtures. The main feature of...
Effect of fracture spacing on VAPEX performance in heavy oil fracture systems
, Article Iranian Journal of Chemistry and Chemical Engineering ; Volume 27, Issue 1 , 2008 , Pages 35-45 ; 10219986 (ISSN) ; Kharrat, R ; Ghotbi, C ; Vossoughi, S ; Sharif University of Technology
2008
Abstract
The vapor extraction (VAPEX) process; a solvent-based enhanced oil recovery process has been found promising for some heavy oil reservoirs. In this work, the VAPEX process is studied using a compositional simulator on a number of single-block and multiple block fractured systems. PVT data of one of an Iranian heavy oil reservoir are used to tune the equation of state. Effects of fracture spacing on the performance of process were studied. It was found that the fracture network enhances the VAPEX process in low-permeability systems by increasing the contact area between solvent and oil contained in the matrix blocks. Also, the fracture network reduced the instabilities in the system pressure...
Modeling and Simulation of Non-Darcy Gas Flow During Underground Gas Storage in One of Iranian Reservoirs
, M.Sc. Thesis Sharif University of Technology ; Taghikhani, Vahid (Supervisor) ; Azin, Reza (Supervisor)
Abstract
The Darcy’ law is valid for low velocity or low Reynolds number where merely viscous force is responsible for pressure loss in the porous media. At higher velocity, because of inertial forces and turbulency, the pressure loss would be higher than Darcy’ law estimates; therefore at these flow regimes the Darcy’ law is no longer valid. Hence, consideration of Non-Darcy flow effect is necessary to sufficiently model high gas velocity effects. The velocity is high in gas reservoirs especially those ones that are considered for underground gas storage. In this study, the effects of Non-Darcy flow on several parameters such as; estimation of differential pressure, flowing bottom hole pressure,...
The corresponding-states correlation for the prediction of crude Oil undersaturated densities
, Article Energy Sources, Part A: Recovery, Utilization and Environmental Effects ; Volume 33, Issue 18 , Jul , 2011 , Pages 1739-1746 ; 15567036 (ISSN) ; Eslami, H ; Shah Karami, A. R ; Keshavarz, G ; Sharif University of Technology
2011
Abstract
In this work, a corresponding-states correlation is presented for prediction of crude oil density in an undersaturated state. The correlation is the extension of corresponding-states liquid densities correlation. The modified corresponding states liquid densities method for predicting saturated liquid densities was coupled with the Tait equation to predict undersaturated densities. Correlations are proposed for the temperature-dependence of Tait equation parameters. Applying proper mixing and combining rules, we calculated the density of 26 crude-oil samples, mainly from Iranian reservoirs. The mixtures included a variety of compositions including N2, H 2S, CO2, and hydrocarbons. The AAD%...
Automatic Blank Verse Poet Identification Using Linguistic Features
, M.Sc. Thesis Sharif University of Technology ; Bahrani, Mohammad (Supervisor) ; Khosravi Zadeh, Parvaneh (Co-Advisor)
Abstract
Author identification using statistical methods is a branch of authorship attribution which is one of important problems in natural language processing. Using different statistical methods, an anonymous text is attributed to an author. One of the primary parts of the task is to choose the appropriate stylistic features of the text in order to study the significances of style. These features must be quantitatively studied and could be extracted in lexical level, character level, and syntactic or semantic levels. The next step is text classification in which different machine learning methods such as decision tree, Artificial Neural Networks, Naïve Bayes and other methods could be used....
Analysis and Modeling of Air Pollution using Big Data Methods in Tehran City
, M.Sc. Thesis Sharif University of Technology ; Boroushaki, Mehrdad (Supervisor) ; Avami, Akram (Supervisor) ; Nahvijou, Azin (Co-Supervisor)
Abstract
Air pollution is a prevalent and pressing issue in Tehran, with significant impacts on both the environment and human health. this study uses statistical techniques, such as Pearson correlation, to determine the direction of influence of meteorological parameters on air pollutant concentrations, and Convergent Cross Mapping to quantify the causal relationship between meteorological parameters and ambient air pollutant concentrations, as well as feedback effects. Additionally, the research delves into the correlation between consumption of fossil fuels and air pollutants, as well as the relationship between lung cancer incidence and mortality by histological subtype and long-term exposure to...
Agent-Based Modeling to Estimate Exposure to Urban Air Pollution from Transportation to Assess Carcinogenic Effect
, M.Sc. Thesis Sharif University of Technology ; Avami, Akram (Supervisor) ; Boroushaki, Mehrdad (Supervisor) ; Nahvijou, Azin (Co-Supervisor)
Abstract
Air pollution in major cities has been a concern for over half a century, but its impact on public health has grown significantly in recent years, causing severe physical, mental, and financial harm. This project aims to propose effective policies to mitigate air pollution by focusing on the transportation sector. Transportation demand is analyzed through four scenarios, each addressing changes in public transportation usage, the promotion of cycling and walking culture, the penetration of digital solutions, and flexible working hours. The project, using the Huvaal model, forecasts transportation demand in 2050 under various population and climate conditions, based on artificial population...
The online atlas of the languages of Iran: Design, methodology and initial results
, Article Language Related Research ; Volume 12, Issue 2 , 2021 , Pages 231-291 ; 23223081 (ISSN) ; Anonby, E ; Hayes, A ; Azin, Z ; Ebrahimi, Z ; Öpengin, E ; Atabaki, N. A ; Stone, A ; Stilo, D ; Esmaeelpour, E ; Amani Babadi, M ; Ourang, M ; Izadi, E ; Oikle, R ; Bahrani, N ; Borjian, H ; Bahrami, A ; Poshtvan, H ; Piryaee, S ; Pishyardehkordi, P ; Sabethemmatabadi, P ; Jaafari Dehaghi, S ; Doab, M. J ; Jamaleddin, F ; Joulaei, K ; Shabaniyan, H. H ; Khanjani, J ; Dianat, L ; Rashidi, A ; Borujeni, R. R ; Rahnema, Z ; Zamani Gandomani, Z ; Schreiber, L ; Sherafat, N ; Sheyholislami, J ; Salehi, M ; Talebi Dastenaei, M ; Kasgari, A. A. A ; Ghiasian, M. S ; Fattahi, M ; Ghandi, S ; Gheitasi Doolabi, M ; Kamali, R ; Goshtasb, F ; Bahmani, H. M ; Mohammadi, M ; Moradi, R ; Meshkinfam, M ; Khoo, R. M ; Bahram, A. N ; Nemati, F ; Nourzaei, M ; Wang, E ; Hashemi Zarajabad, H ; Sharif University of Technology
Tarbiat Modares University
2021
Abstract
Iran is home to a treasury of languages representing diverse language families: Iranic, Turkic, Semitic, Indic, Dravidian, Armenian, and Kartvelian, as well as sign languages. Despite valuable research carried out by Iranian and western scholars, there is still no comprehensive publication depicting the geographic distribution and linguistic status of language varieties in Iran. In order to work toward this goal, the Atlas of the Languages of Iran (ALI) (www.iranatlas.net) was officially launched in 2015 as an international, online research programme. The present study opens with a historical overview of the research context and underlines the ongoing necessity of constructing such an atlas...
Probability of missed detection as a criterion for receiver placement in MIMO PCL
, Article IEEE National Radar Conference - Proceedings, 7 May 2012 through 11 May 2012, Atlanta, GA ; 2012 , Pages 0924-0927 ; 10975659 (ISSN) ; 9781467306584 (ISBN) ; Chitgarha, M. M ; Radmard, M ; Nayebi, M. M ; Sharif University of Technology
IEEE
2012
Abstract
Using multiple antennas at the transmit and receive sides of a passive radar brings both the benefits of MIMO radar and passive radar. However one of the obstacles arisen in such configuration is the receive antennas placement in proper positions so that the radar performance is improved. Here we just consider the case of positioning one receiver among multiple illuminators of opportunity. Indeed it is a start for the solution of optimizing the geometry of the multiple receivers in a passive radar
An efficient method for the ring opening of epoxides with aromatic amines by Sb(III) chloride under microwave irradiation
, Article Journal of Chemical Research ; Issue 4 , 2008 , Pages 220-221 ; 03082342 (ISSN) ; Hashemi, M. M ; Mottaghi, M. M ; Foroughi, M. M ; Sharif University of Technology
2008
Abstract
SbCl3 supported on montmorillonite K-10 is an efficient catalyst for the ring opening of epoxides with aromatic amines under solvent-free conditions and microwave irradiation to give the corresponding b-amino alcohols in high yields with high regioselectivity
Resource allocation for uav-enabled integrated sensing and communication (isac) via multi-objective optimization
, Article ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings ; Volume 2023-June , 2023 ; 15206149 (ISSN); 978-172816327-7 (ISBN) ; Naghsh, M. M ; Karbasi, M ; Nayebi, M. M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2023
Abstract
In this paper, we consider an integrated sensing and communication (ISAC) system with wireless power transfer (WPT) where an unmanned aerial vehicle (UAV)-based radar serves a group of energy-limited communication users in addition to its sensing functionality. In this architecture, the radar senses the environment in phase 1 (namely sensing phase) and mean-while, the communications users (nodes) harvest and store the energy from the radar transmit signal. The stored energy is then used for information transmission from the nodes to UAV in phase 2, i.e., uplink phase. Performance of the radar system depends on the transmit signal as well as the receive filter; the energy of the transmit...
MIMO radar signal design to improve the MIMO ambiguity function via maximizing its peak
, Article Signal Processing ; Volume 118 , 2016 , Pages 139-152 ; 01651684 (ISSN) ; Radmard, M ; Nazari Majd, M ; Karbasi, S. M ; Nayebi, M. M ; Sharif University of Technology
Elsevier
2016
Abstract
One of the important obstacles in MIMO (Multiple Input Multiple Output) radars is the issue of designing proper transmit signals. Indeed, the capability of signal design is a significant advantage in MIMO radars, through which, the system can achieve much better performance. Many different aspects of this performance improvement have been considered yet, and the transmit signals have been designed to attain such goal, e.g., getting higher SNR or better detector's performance at the receiver. However, an important tool for evaluating the radar's performance is its ambiguity function. In this paper, we consider the problem of transmit signal design, in order to optimize the ambiguity function...
Detection-localization tradeoff in MIMO radars
, Article Radioengineering ; Volume 26, Issue 2 , 2017 , Pages 581-587 ; 12102512 (ISSN) ; Radmard, M ; Chitgarha, M. M ; Bastani, M. H ; Nayebi, M. M ; Sharif University of Technology
2017
Abstract
Two gains play key roles in recently developed MIMO wireless communication systems: "spatial diversity" gain and "spatial multiplexing" gain. The diversity gain refers to the capability to decrease the error rate of the MIMO channel, while the multiplexing gain implicitly refers to the amount of increase in the capacity of the MIMO channel. It has been shown that there is a fundamental tradeoff between these two types of gains, meaning interplay between increasing reliability (via an increase in the diversity gain) and increasing data rate (via an increase in the multiplexing gain). On the other hand, recently, MIMO radars have attracted much attention for their superior ability to enhance...
Antenna placement and power allocation optimization in MIMO detection
, Article IEEE Transactions on Aerospace and Electronic Systems ; Vol. 50, Issue 2 , April , 2014 , pp. 1468-1478 ; Chitgarha, M. M ; Majd, M. N ; Nayebi, M. M ; Sharif University of Technology
2014
Abstract
It is a well known fact that using multiple antennas at transmit and receive sides improves the detection performance. However, in such multiple-input multiple-output (MIMO) configuration, proper positioning of transmitters and receivers is a big challenge that can have significant influence on the performance of the overall system. In addition, determining the power of each transmitter under a total power constraint is a problem that should be solved in order to enhance the performance and coverage of such a system. In this paper, we design the Neyman-Pearson detector under the Rayleigh scatter model and use it to introduce a criterion for the antenna placement at both transmit and receive...
Ambiguity function of MIMO radar with widely separated antennas
, Article Proceedings International Radar Symposium ; 16 -18 June , 2014 ; ISSN: 21555753 ; Chitgarha, M. M ; Nazari Majd, M ; Nayebi, M. M ; Sharif University of Technology
2014
Abstract
There has been much interest, recently, towards exploiting the Multiple-Input Multiple-Output (MIMO) technique in radar. It is shown that using multiple antennas at transmit and receive sides can improve the performance of the system. However, in order to analyze the system's performance, its ambiguity function, i.e. the ambiguity function of a MIMO radar, is needed to be defined. In this paper, beginning from the information theoretic definitions, we derive such function, specifically for a MIMO radar with widely separated antennas