Loading...
Search for:
ghani--s
0.107 seconds
Total 10334 records
Correction to: Oseledets Splitting and Invariant Manifolds on Fields of Banach Spaces (Journal of Dynamics and Differential Equations, (2021), 10.1007/s10884-021-09969-1)
, Article Journal of Dynamics and Differential Equations ; 2021 ; 10407294 (ISSN) ; Riedel, S ; Sharif University of Technology
Springer
2021
Abstract
The original version of this article unfortunately contained a typo in co-author name. The author name is “Mazyar Ghani Varzaneh” instead it was published incorrectly as “M. Mazyar Ghani Varzaneh”. © 2021, Springer Science+Business Media, LLC, part of Springer Nature
Oseledets splitting and invariant manifolds on fields of banach spaces
, Article Journal of Dynamics and Differential Equations ; 2021 ; 10407294 (ISSN) ; Riedel, S ; Sharif University of Technology
Springer
2021
Abstract
We prove a semi-invertible Oseledets theorem for cocycles acting on measurable fields of Banach spaces, i.e. we only assume invertibility of the base, not of the operator. As an application, we prove an invariant manifold theorem for nonlinear cocycles acting on measurable fields of Banach spaces. © 2021, The Author(s)
A dynamical theory for singular stochastic delay differential equations i: linear equations and a multiplicative ergodic theorem on fields of banach spaces
, Article SIAM Journal on Applied Dynamical Systems ; Volume 21, Issue 1 , 2022 , Pages 542-587 ; 15360040 (ISSN) ; Riedel, S ; Scheutzow, M ; Sharif University of Technology
Society for Industrial and Applied Mathematics Publications
2022
Abstract
We investigate singular stochastic delay differential equations (SDDEs) in view of their long-time behavior. Using Lyons's rough path theory, we show that SDDEs can be solved pathwise and induce a continuous stochastic flow on the space of (Gubinelli's) controlled paths. In the language of random dynamical systems, this result shows that SDDEs induce a continuous cocycle on random fibers, or, more precisely, on a measurable field of Banach spaces. We furthermore prove a multiplicative ergodic theorem (MET) on measurable fields of Banach spaces that applies under significantly weaker structural and measurability assumptions than preceding METs. Applying it to linear SDDEs shows that the...
Attitude and Deformation Estimation of Flexible Satellite Using Magnetometer and Sun Sensor
, M.Sc. Thesis Sharif University of Technology ; Asadian, Nima (Supervisor)
Abstract
The estimation of attitude and deformation of a flexible satellite using magnetometer and sun sensor data are studied in this thesis. To this end, the dynamical differential equations of the flexible satellite have been derived using Lagrange’s equation. These equations of motion are then utilized for the purpose of simulation and verification. After introducing the measurements equations, the observability of the satellite with flexible panels has been evaluated. Afterward, the attitude of the satellite body and deformation of the flexible panels have been estimated by EKF (Extended Kalman Filter) as well as UKF (Unscented Kalman Filter). The results show that the estimations using UKF are...
Distributed algorithms for power saving optimization in sensor network
, Article Proceedings of the 8th WSEAS International Conference on Data Networks, Communications, Computers, DNCOCO '09, 7 November 2009 through 9 November 2009 ; 2009 , Pages 109-115 ; 9789604741342 (ISBN) ; Mousavi, M ; Movaghar, A ; Sharif University of Technology
2009
Abstract
Sensor networks have a wide range of potential and practical application. A sensor network consists of a large number of tiny, low power and short-living sensors. Some sensor network applications require k-coverage to ensure the quality of surveillance. Meanwhile, energy is another primary concern for sensor networks. In this dissertation, an algorithm proposed which groups sensors in to disjoint subsets. Every subset cans k-cover the whole area. The subsets are scheduled to work successively. Therefore, the network lifetime is prolonged. Furthermore, sensing range is fixed. Also another algorithm, proposed which constructs some non-disjoint subsets, and in each active subset, each sensor...
An internally coded time-hopping spread-time CDMA scheme for UWB systems and its performance analysis
, Article 2007 IEEE Radio and Wireless Symposium, RWS, Long Beach, CA, 9 January 2007 through 11 January 2007 ; 2007 , Pages 511-514 ; 9781424404452(ISBN) ; Nasiri Kenari, M ; Sharif University of Technology
2007
Abstract
We consider an internally coded multiple access technique for Ultra Wide-Band systems which combines time-hopping (TH) and spread-time (ST) techniques using a super-orthogonal encoder. In this method, the duration of each bit is divided into Ns frames. The outputs of a superorthogonal encoder and a PN sequence specify the frame number, in which the data is transmitted in spread-time CDMA form using the second PN sequence. We consider soft decision before Viterbi decoding at the receiver. We obtain the performance of the proposed method. We also consider the uncoded ST-CDMA system and compare its performance with our method. The results indicate that our method has much more better...
Performance analysis of an internally coded MC-FH-CDMA system
, Article 2007 IEEE International Conference on Telecommunications and Malaysia International Conference on Communications, ICT-MICC 2007, Penang, 14 May 2007 through 17 May 2007 ; February , 2007 , Pages 23-28 ; 1424410940 (ISBN); 9781424410941 (ISBN) ; Nasiri Kenari, M ; Sharif University of Technology
2007
Abstract
We consider an internally coded scheme for multicarrier frequency-hopping CDMA (MC-FH-CDMA) communication systems. In this method, the total bandwidth is partitioned into Ns1 disjoint bands and each band is also segmented into Ns2 subbands. Based on the super-orthogonal encoder output and a pseudorandom (PN) sequence, one of the Ns1 bands is selected. Then, the data is transmitted in that band in the form of multicarrier frequency-hopping technique using BPSK modulation. At the receiver front end, we use soft detector, then we apply Viterbi decoding algorithm. We evaluate the performance of the proposed method. The results indicate that our method outperforms the previously presented uncoded...
Attitude and deformation coupled estimation of flexible satellite using low-cost sensors
, Article Advances in Space Research ; Volume 69, Issue 1 , 2022 , Pages 677-689 ; 02731177 (ISSN) ; Assadian, N ; Varatharajoo, R ; Sharif University of Technology
Elsevier Ltd
2022
Abstract
Solar panel flexibility plays an important role in the attitude control of satellites. Therefore, traditionally the deformations of flexible solar panels are measured with a series of sensors along the panels itself. This paper presents a novel maiden attempt to simultaneously estimate the attitude and deformation of a flexible satellite using only 2 low-cost attitude sensors namely the sun sensor and magnetometer measurements. The flexible satellite is considered as a central rigid body with two attached flexible panels in order to derive the governing dynamic equations based on the Lagrange's equation. Both Extended Kalman filter (EKF) and Unscented Kalman Filter (UKF) are employed for the...
Dynamical Properties of Rough Delay Equations
, Ph.D. Dissertation Sharif University of Technology ; Zohuri Zangeneh, Bijan (Supervisor)
Abstract
In this monograph, we investigate the long-time behavior of stochastic delay equations. Our approach is random dynamical systems, and we solve our equation in the rough path point of view. Namely, we deal with the singular case, i.e., when the delay terms also are appearing in the diffusion part. Although we can solve the equation using the classical tools of stochastic analysis, the main obstacle is the lack of flow property. More precisely, the solution does not depend continuously on the initial value. To solve this problem, we define this property differently. We will show how we can generate a flow property on fields of Banach spaces using rough path theory. As a consequence, we prove...
Synthesis of Sr3Fe2O7and Investigation of the Effect of Pr in Sr Site and Co in Fe Site as a Dopant on the Microstructure and its Function as a Solid Oxide Fuel Cathode
, M.Sc. Thesis Sharif University of Technology ; Nemati, Ali (Supervisor) ; Golmohammad, Mohammad (Supervisor)
Abstract
Nowday, one of the important goals of researchers is to develop and improve the properties of intermediate tempreture solid oxide fuel cells with range of 600-800˚C. Therefore, choosing the right material as a cathode with good performance in this temperature range is very important. For this purpose, various materials with ionic and electron conductivity mixtures (MIECs) are used, especially oxides with a Radelsden-Paper structure. These oxides are shown by the formula An+1BnC3n+1, which are actually composed of a combination of perovskite layers (ABO3) that are alternately superimposed between two layers of rock salt (AO). In the present study, Sr3Fe2O7 powder with different amounts...
Improved salinity tolerance in early growth stage of maize through salicylic acid foliar application
, Article Italian Journal of Agronomy ; Volume 16, Issue 3 , 2021 ; 11254718 (ISSN) ; Khan, I ; Chattha, M. U ; Hassan, M. U ; Barbanti, L ; Calone, R ; Ali, M ; Majeed, S ; Ghani, M. A ; Batool, M ; Izzat, W ; Usman, S ; Sharif University of Technology
Page Press Publications
2021
Abstract
Soil salinity threatens agricultural production worldwide by constraining plant growth and final crop yield. The early stages are most sensitive to salinity, in response to which salicylic acid (SA) has demonstrated beneficial effects in various plant species. Based on this, a maize (Zea mays L.) pot experiment was set up combining three levels of soil salinity (0, 6 and 12 dS m–1), obtained through NaCl addition, with three levels of SA (0, 300 and 600 mM), applied by leaf spraying 20 days after seedling emergence. Fifteen days later, the following traits were assessed: morphology (plant height, leaf number), growth (root and shoot dry weight), leaf water status [relative water content...
Characterization of PAHs and metals in indoor/outdoor PM10 /PM2.5 /PM1 in a retirement home and a school dormitory
,
Article
Science of the Total Environment
;
Volume 527-528
,
September
,
2015
,
Pages 100-110
;
00489697 (ISSN)
; Naddafi, K
; Faridi, S
; Nabizadeh, R
; Sowlat, M. H
; Momeniha, F
; Gholampour, A
; Arhami, M
; Kashani, H
; Zare, A
; Niazi, S
; Rastkari, N
; Nazmara, S
; Ghani, M
; Yunesian, M
;
Sharif University of Technology
Elsevier
2015
Abstract
In the present work, we investigated the characteristics of polycyclic aromatic hydrocarbons (PAHs) and metal(loid)s in indoor/outdoor PM10 , PM2.5 , and PM1 in a retirement home and a school dormitory in Tehran from May 2012 to May 2013. The results indicated that the annual levels of indoor and outdoor PM10 and PM2.5 were much higher than the guidelines issued by the World Health Organization (WHO). The most abundant detected metal(loid)s in PM were Si, Fe, Zn, Al, and Pb. We found higher percentages of metal(loid)s in smaller size fractions of PM. Additionally, the results showed that the total PAHs (ΣPAHs) bound to PM were...
Characterization of ionic composition of TSP and PM10 during the Middle Eastern Dust (MED) storms in Ahvaz, Iran
, Article Environmental Monitoring and Assessment ; Volume 184, Issue 11 , November , 2012 , Pages 6683-6692 ; 01676369 (ISSN) ; Naddafi, K ; Jaafarzadeh Haghighifard, N ; Mesdaghinia, A ; Yunesian, M ; Nabizadeh, R ; Arhami, M ; Yarahmadi, M ; Sowlat, M. H ; Ghani, M ; Jonidi Jafari, A ; Alimohamadi, M ; Motevalian, S. A ; Soleimani, Z ; Sharif University of Technology
2012
Abstract
Because of the recent frequent observations of major dust storms in southwestern cities in Iran such as Ahvaz, and the importance of the ionic composition of particulate matters regarding their health effects, source apportionment, etc., the present work was conducted aiming at characterizing the ionic composition of total suspended particles (TSP) and particles on the order of ∼10 μm or less (PM10) during dust storms in Ahvaz in April-September 2010. TSP and PM10 samples were collected and their ionic compositions were determined using an ion chromatography. Mean concentrations of TSP and PM10 were 1,481.5 and 1,072.9 μg/m 3, respectively. Particle concentrations during the Middle Eastern...
The relationship between an EFL teacher's gender and students' willingness to communicate
, Article International Journal of Communication and Linguistic Studies ; Volume 10, Issue 4 , 2013 , Pages 17-29 ; 23277882 (ISSN) ; Pakzadian, S. S
Common Ground Publishing
2013
Abstract
Learning a foreign language encompasses a process of trial and error that can lead to the progression of the learner's interlanguage, meaning that the learners make use of their language knowledge that receives feedback and brings about progress through diagnosis of the problems and being corrected by the teacher. Therefore, there exists a need to analyze the underlying reasons causing the students to remain taciturn with a low willingness to communicate (WTC) during a language class. There has been much work done investigating the role of the learner's stable personal characteristics (traits) along with their situational changes at a specific time (states) that influence the student's...
An automated simple algorithm for realistic pore network extraction from micro-tomography images
, Article Journal of Petroleum Science and Engineering ; Vol. 123, issue , 2014 , pp. 164-171 ; ISSN: 09204105 ; Jamshidi, S ; Salehi, S
2014
Abstract
Using 3-D scanned data to analyze and extract pore network plays a vital role in investigation of porous media's characteristics. In this paper, a new simple method is developed to detect pores and throats for analyzing the connectivity and permeability of the network. This automated method utilizes some of the common and well-known image processing functions which are widely accessible by researchers and this has led to an easy algorithm implementation. In this method, after polishing and quality control of images, using city-block distance function and watershed segmentation algorithm, pores and throats are detected and 3-D network is produced. This method can also be applied on 2-D images...
Discrimination of heart arrhythmias using novel features in heart rate phase space
, Article Computing in Cardiology ; Volume 40 , Sept , 2013 , Pages 1035-1038 ; 23258861 (ISSN); 9781479908844 (ISBN) ; Rezaei, S ; Salavatian, S
2013
Abstract
In this paper, we try to recognize and distinguish different groups of arrhythmia using novel features which have been obtained from the heart rate's phase space in recent years. For this purpose, we used Triangular Phase Space Mapping (TPSM) and Parabolic Phase Space Mapping (PPSM). For recognition, we used three groups of 15 subjects using the Physionet database (Arrhythmia, Congestive Heart Failure (CHF), and Atrial Fibrillation (AF)) with Normal Sinus Rhythm (NSR). The obtained features discriminate arrhythmia from NSR by p
An intelligent hybrid classification algorithm integrating fuzzy rule-based extraction and harmony search optimization: Medical diagnosis applications
, Article Knowledge-Based Systems ; Volume 220 , 2021 ; 09507051 (ISSN) ; Abdullah, S ; Akhavan Niaki, S. T ; Banihashemi, S ; Sharif University of Technology
Elsevier B.V
2021
Abstract
Uncertainty is a critical factor in medical datasets needed to be overcome for increasing diagnosis efficiency. This paper proposes an intelligent classification algorithm comprising a fuzzy rule-based approach, a harmony search (HS) algorithm, and a heuristic algorithm to classify medical datasets intelligently. Two fuzzy approaches, as well as orthogonal and triangular fuzzy sets, are first utilized to define the attributes of data. Then, an HS algorithm is integrated with a heuristic to generate fuzzy rules to select the best rules in the fuzzy rule-based systems. Moreover, to improve the performance of the proposed classification approach, a three-phase parameter tuning approach is...
Performance evaluation of shared hosting security methods
, Article Proc. of the 11th IEEE Int. Conference on Trust, Security and Privacy in Computing and Communications, TrustCom-2012 - 11th IEEE Int. Conference on Ubiquitous Computing and Communications ; 2012 , Pages 1310-1315 ; 9780769547459 (ISBN) ; Arshad, S ; Khoshkdahan, S ; Sharif University of Technology
2012
Abstract
Shared hosting is a kind of web hosting in which multiple websites reside on one webserver. It is cost-effective and makes the administration easier for websites' owners. However, shared hosting has some performance and security issues. In default shared hosting configuration, all websites' scripts are executed under the webserver's user account regardless of their owners. Therefore, a website is able to access other websites' resources. This security problem arises from lack of proper isolation between different websites hosted on the same webserver. In this survey, we have examined different methods for handling mentioned security issue. Also we evaluated the performance of mentioned...
The behaviour of an artificially cemented sandy gravel
, Article Geotechnical and Geological Engineering ; Volume 23, Issue 5 , 2005 , Pages 537-560 ; 09603182 (ISSN) ; Hosseini, S. M ; Toll, D. G ; Yasrebi, S. S ; Sharif University of Technology
2005
Abstract
The major section of the city of Tehran, Iran has been developed on cemented coarse-grained alluvium. This deposit consists of gravely sand to sandy gravel with some cobbles and is dominantly cemented by carbonaceous materials. In order to understand the mechanical behaviour of this soil, a series of undrained triaxial compression tests and unconfined compression tests were performed on uncemented and artificially cemented samples. Portland cement type I was used as the cementation agent for preparing artificially cemented samples. Uncemented samples and lightly cemented samples (1.5% cement) tested at high confining pressure showed contractive behaviour accompanied with positive excess pore...
An imperialist competitive algorithm approach for multi-objective optimization of direct coupling photovoltaic-electrolyzer systems
, Article International Journal of Hydrogen Energy ; Vol. 39, Issue 33 , 11 November , 2014 , pp. 18743-18757 ; ISSN: 03603199 ; Sayedin, F ; Khavas, S. S
2014
Abstract
In the context of sustainable clean hydrogen production pathways, photovoltaic-electrolyzer systems are one of the most promising alternatives for acquiring hydrogen from renewable energy sources. In fact, determining the optimal set of design and operating variables are always a key issue while coupling directly renewable electricity sources to PEM electrolyzers. Few previous studies have attempted to find the optimal size and operational condition of directly coupled photovoltaic-electrolyzer (PV/El) systems in order to maximize the hydrogen production or to minimize energy transfer loss between photovoltaic devices and the electrolyzer. Nevertheless an easy and efficient approach still...