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A new achievable rate for a stochastic two relay network with no interference
, Article 2008 42nd Asilomar Conference on Signals, Systems and Computers, ASILOMAR 2008, Pacific Grove, CA, 26 October 2008 through 29 October 2008 ; June , 2008 , Pages 909-913 ; 10586393 (ISSN); 9781424429417 (ISBN) ; Sharif University of Technology
2008
Abstract
Gastpar and Vetterli named the adhoc networks with one randomly selected source-destination pair as relay networks and they suggested using arbitrary network coding in order to increase the overall efficiency Here, the relay network is investigated with two relays and no interference and a new achievable rate is obtained using a new network coding (decodeand-broadcast). The obtained achievable rate (i) gives the lower bound for the general relay channel, obtained by Cover and El Gamal, but with slight difference due to no interference assumption at the receiver (ii) includes the one relay rates of a two-level relay channel studied by Gupta and Kumar using point to point coding, (iii)...
Capacity of Almost General Relay Channel and Aref Network with Random Links
, Ph.D. Dissertation Sharif University of Technology ; Aref, Mohammad Reza (Supervisor)
Abstract
First, we review in an appropriate way the researches regarding building blocks of a wireless network (Shannon channel, multiple access channel, broadcast channel, interference channel, relay channel) and then: • We consider two cases for a relay and describe the essential role of the relay with three Markovity conditions; define Almost General Relay Channel with Decode-And-Forward (AGRCDAF) strategy and determine its capacity. Then, we prove that our capacity theorem not only includes all known capacity theorems as its special cases but also potentially is applicable to other relay channels and is validated by its consistency with previous results related to special cases of broadcast and...
The capacity region for broadcast channels with conditionally independent message sets
, Article 4th Advanced International Conference on Telecommunications, AICT 2008, Athens, 8 June 2008 through 13 June 2008 ; 2008 , Pages 283-286 ; 9780769531625 (ISBN) ; Sharif University of Technology
2008
Abstract
A more general class of broadcast channels with conditionally independent message sets is defined and its capacity region is determined using Marton's inner bound and the outer bound considered by Nair and El Gamal. The capacity region for this class of channels includes the capacity region for broadcast channels with degraded message sets, semi-deterministic broadcast channels, deterministic broadcast channels with and without common information, less noisy and (special) more capable broadcast channels. © 2008 IEEE
Capacity of a more general class of relay channels
, Article 2008 International Symposium on Information Theory and its Applications, ISITA2008, Auckland, 7 December 2008 through 10 December 2008 ; April , 2008 ; 9781424420698 (ISBN) ; Aref, M. R ; Commemorative Organization for the Japan World; Exposition('70); Support Center for Advanced Telecommunications; Technology Research; REFEC Research Foundation for the; Electrotechnology of Chubu ; Sharif University of Technology
2008
Abstract
Capacity has been found for degraded, reversely degraded, full feedback, semi-deterministic, orthogonal relay channels, also for a class of deterministic relay channels and a class of modulo sum relay channels. We indicate what the relay decodes and forwards with one auxiliary random variable having bounded cardinality and attempt to define a more general class of relay channels in order to unify most of known capacity theorems into one capacity theorem by considering additional assumptions imposed to the definition of those channels. In other words, the relay channel inputs are dependent as in multiple access channel with arbitrarily correlated sources and here we do for the relay channel...
New achievable rate and a certain capacity result for a stochastic two relay network with no interference
, Article IET Communications ; Volume 3, Issue 7 , 2009 , Pages 1153-1162 ; 17518628 (ISSN) ; Aref, M. R ; Sharif University of Technology
2009
Abstract
Gastpar and Vetterli named the ad hoc networks with one randomly selected source-destination pair as relay networks, and they suggested using arbitrary network coding in order to increase the overall efficiency. Here, the relay network is investigated with two relays, no interference and a new achievable rate is obtained using a new network coding (decode-and-broadcast). The obtained achievable rate (i) gives the lower bound for general relay channel, obtained by Cover and El Gamal, but with a slight difference owing to no interference assumption at the receiver, (ii) includes the one relay rates of a two-level relay channel studied by Gupta and Kumar using point-to-point coding, (iii)...
Unified approach to the capacity evaluation of the relay channel
, Article IET Communications ; Volume 3, Issue 7 , 2009 , Pages 1208-1215 ; 17518628 (ISSN) ; Aref, M. R ; Sharif University of Technology
2009
Abstract
The authors indicate the dependence between the inputs of the relay channel with one auxiliary random variable as Cover, El-Gamal and Salehi have done for the multiple access channel with arbitrarily correlated sources. Then, by considering broadcast and multiple access sub-channels in the relay channel, the authors describe the essential role of the relay with special Markovity conditions on the auxiliary random variable and channel input-outputs, and unify most of known capacity theorems into one capacity theorem. The capacity theorem potentially may be applicable to a more general class of relay channels including at least the relay channels with known capacity. © The Institution of...
On the devroye-mitran-tarokh rate region for the cognitive radio channel
, Article IEEE Transactions on Wireless Communications ; Volume 8, Issue 7 , 2009 , Pages 3458-3461 ; 15361276 (ISSN) ; Aref, M. R ; Sharif University of Technology
2009
Abstract
An achievable rate region for the genie-aided cognitive radio channel is obtained using the celebrated HanKobayashi jointly decoding strategy for the interference channel and the Gel'fand-Pinsker coding scheme for channels with side information known at the transmitter. The achievable rate region is then simplified by Fourier-Motzkin elimination. The obtained achievable rate region (i) extends the Chong-Motani-Garg region for the interference channel to the cognitive channel and (ii) is a simplified description of the Devroye-Mitran-Tarokh rate region for the genie-aided cognitive radio channel. © 2009 IEEE
Brain Decoding Across Subjects
, M.Sc. Thesis Sharif University of Technology ; Shamsollahi, Mohammad Bagher (Supervisor)
Abstract
In recent years, techniques in articial intelligence have become an important tool in the analysis of physiological signals. While the application of machine learning techniques has proved useful in other elds, researchers have had difficulty proving its utility for the analysis of physiological signals. A major challenge in applying such techniques to the analysis of physiological signals is dealing effectively with inter-patient differences. The morphology and interpretation of physiological signals can vary dep ending on the patient. This poses a problem, since statistical learning techniques aim to estimate the underlying system that produced the data. If the system (or patient) changes...
Unsupervised cross-subject BCI learning and classification using riemannian geometry
, Article 24th European Symposium on Artificial Neural Networks, Computational Intelligence and Machine Learning, ESANN 2016, 27 April 2016 through 29 April 2016 ; 2016 , Pages 307-312 ; 9782875870278 (ISBN) ; Shamsollahi, M. B ; Jutten, C ; Congedo, M ; Sharif University of Technology
i6doc.com publication
2016
Abstract
The inter-subject variability poses a challenge in cross-subject Brain-Computer Interface learning and classification. As a matter of fact, in cross-subject learning not all available subjects may improve the performance on a test subject. In order to address this problem we propose a subject selection algorithm and we investigate the use of this algorithm in the Riemannian geometry classification framework. We demonstrate that this new approach can significantly improve cross-subject learning without the need of any labeled data from test subjects
The contagion effects of global financial crisis on Tehran Stock Exchange
, M.Sc. Thesis Sharif University of Technology ; Keshavarz Haddad, Gholamreza (Supervisor)
Abstract
US 2008 financial crisis, spread across the international stock markets in the second half of the year 2008. The crisis decreased the returns and increased the volatilities of almost all of the stock indices, however, its effects on Iran’s stock markets were unexplored. Financial limitations create an exclusive situation in Iran’s stock market. Using weekly data on the stock indices from July 2006 through August 2009, this study aims to exam in the contagion effects of the global financial crisis through the main indices such as S&P500 and FTSE100 on Tehran Stock Exchange indices: industrial and financial intermediary indices and The First and the Second indices of Tehran’s Stock Exchange....
Multiuser detector for airborne co-located multiple input/multiple output radar using compressive measurements
, Article IET Radar, Sonar and Navigation ; Volume 11, Issue 2 , 2017 , Pages 260-268 ; 17518784 (ISSN) ; Salehi, J. A ; Hariri, A ; Sharif University of Technology
Institution of Engineering and Technology
2017
Abstract
This study presents and analyses a novel joint detection and parameters estimation of multiple targets using a co-located multiple input/multiple output radar with moving platform, in the presence of clutter and background noise. A notable feature of the proposed approach is that clutter cancellation is independent of received data. Moreover, to decrease the computational load, the authors propose to perform the target detection and parameters estimation by directly processing on the compressive measurements as opposed to Nyquist samples. © The Institution of Engineering and Technology
CFD Simulation and Analysis of Heat Pipe Heat Exchanger Radiator
, M.Sc. Thesis Sharif University of Technology ; Shafii, Mohammad Behshad (Supervisor)
Abstract
Due to the development of heat pipes in different industries and special characteristics of heat pipes, in this study, it has been tried using computational fluid dynamics (CFD) method to simulate a heat pipe heat exchanger that can be a replacement for the normal radiator. The experimental model of this heat exchanger has been tested at past studies and the numerical simulation of the heat exchanger will analyze at present study. The use of heat pipe in the car radiator has many advantages such as reducing fluid pressure drop through the heat exchanger, high reliability due to the particular structure of the heat exchanger (individual performance of each heat pipe) and improving heat...
Discrete scale invariance and its logarithmic extension
, Article Nuclear Physics B ; Volume 655, Issue 3 , 2003 , Pages 342-352 ; 05503213 (ISSN) ; Aghamohammadi, A ; Khorrami, M ; Rahimi Tabar, M. R ; Sharif University of Technology
Elsevier
2003
Abstract
It is known that discrete scale invariance leads to log-periodic corrections to scaling. We investigate the correlations of a system with discrete scale symmetry, discuss in detail possible extension of this symmetry such as translation and inversion, and find general forms for correlation functions. © 2003 Published by Elsevier Science B.V
A new approach to model sensitivity of graphene-based gas sensors
, Article Semiconductor Science and Technology ; Volume 30, Issue 4 , March , 2015 ; 02681242 (ISSN) ; Ismail, R ; Naraghi, B ; Taheri Abed, S ; Kavosi, D ; Fotovatikhah, F ; Sharif University of Technology
Institute of Physics Publishing
2015
Abstract
Carbon-based sensors are attractive because of their excellent sensing capability. In this paper, we propose a new approach to analytically model the sensitivity of these devices based on graphene. The model relies on the surface potential and current of the device. For the first time, we included ionization in the modelling and examined the importance of this effect. In order to validate the model, the results are compared with experimental data from a fabricated device
Development of an esco risk assessment model as a decision-making tool for the energy savings certificates market regulator: a case study
, Article Applied Sciences (Switzerland) ; Volume 10, Issue 7 , 2020 ; Hatami, M ; Rahgozar, P ; Shirkhanloo, S ; Abed, S ; Kamalzadeh, H ; Flood, I ; Sharif University of Technology
MDPI AG
2020
Abstract
This article is focused on developing an Energy Service Company (ESCO) risk assessment model for use by energy savings certificates (ESC) market regulators. This model enables market regulators to determine the appropriate point in time for ESCOs to sell their certificates with the aim of minimizing risk as well as maximizing economic gain yet remain motivated for reducing the cost of energy efficiency technologies. To this end, the interactions between an ESCO and other parties (such as suppliers) in the market in addition to the principles of the energy efficiency performance contract are taken into consideration. Then, appropriate probability distributions have been fitted to the...
Use of Bio-Cementation for Reducing Land Subsidence
, M.Sc. Thesis Sharif University of Technology ; Khosravi, Ali (Supervisor) ; Pak, Ali (Supervisor) ; Ghobadi Nejad, Zahra ($item.subfieldsMap.e)
Abstract
Land subsidence is a gradual settling or sudden sinking of the land surface from changes that take place underground. There are different causes of land subsidence; most notably, groundwater overdraft and severe weather conditions. Subsidence of the land surface due to ground water overdraft is caused by an increase in the intergranular pressure in unconsolidated aquifers, which results in a loss of buoyancy of solid particles in the zone dewatered by the falling water table and accordingly compaction of the aquifer. In this study, an experimental approach was developed to examine applicability of Microbially induced carbonate precipitation (MICP) for land subsidence control under...