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Are the magnitude and frequency of floods increasing in Iran due to climate change? implications from a 50-year analysis
, Article Hydrological Sciences Journal ; Volume 68, Issue 15 , 2023 , Pages 2243-2261 ; 02626667 (ISSN) ; Danesh Yazdi, M ; Sharif University of Technology
Taylor and Francis Ltd
2023
Abstract
The correlation between extreme precipitation and flood magnitude is still poorly understood because of the complex mechanisms controlling flood generation. In this study, we used 50 years of precipitation and streamflow data across Iran to analyse the spatial distribution, slope, and significance of long-term trends in extreme precipitation compared to the spatial distribution of long-term trends for flood magnitude and frequency. Despite the decreasing trend of extreme precipitation in 60% of Iran’s sub-basins, the flood magnitude showed an increasing trend. In particular, the number of flooding days with a return period of 25~50 years and >50 years in 2010s has increased by 1.3 and 2.2...
An Optical Sensor Based on Manganese Oxide Nanosheets Oxidation Activity for Detection of Bisulfite in Food Samples
, M.Sc. Thesis Sharif University of Technology ; Bagheri, Habib (Supervisor)
Abstract
Bisulfite is a food additive with preservative and antioxidant properties; however, excessive use can severely damage nutritional compounds in food, reducing nutritional value. Moreover, it can lead to the development of sensitivities, asthma, localized heart anemia, and lung cancer. Therefore, it is essential to establish a simple, innovative, fast, and reliable method for bisulfite identification in foodstuffs. In this research, a novel fluorescence sensor based on manganese oxide nanosheets and carbon dots was designed for bisulfite detection in food samples. Initially, manganese oxide nanosheets were synthesized via a bottom-up approach, and carbon dots were produced using a hydrothermal...
Exploring the Impact of Vegetation Type and Plant Growth Cycle on the Evapotranspiration Storage Selection Function Using Particle Tracking Approach
, M.Sc. Thesis Sharif University of Technology ; Danesh Yazdi, Mohammad (Supervisor)
Abstract
StorAge selection (SAS) functions describe the mechanism by which water particles with different ages exit a hydrological system through outfluxes such as streamflow and evapotranspiration (ET). The shape of the ET SAS functions affects the storage residence time distributions, ET travel time distributions, and discharge travel time distributions that control the hydrochemical dynamics of water. They also carry fundamental information to understand the response behavior of the system, and are affected by processes such as precipitation, outflow, ET, as well as the physical properties of the system. To better understand the shape of these functions, other important factors such as the type...
A rapid and simple method based on manganese oxide nanosheets/tetramethyl benzidine system oxidation activity for bisulfite screening in food samples
, Article Journal of Food Composition and Analysis ; Volume 134 , 2024 ; 08891575 (ISSN) ; Tavoussi Shirazi, D ; Bagheri, H ; Sharif University of Technology
2024
Abstract
Bisulfite is a food additive with preservative and antioxidant properties; however, excessive use can severely damage nutritional compounds in food, reducing nutritional value. Moreover, it can lead to the development of sensitivities, asthma, localized heart anemia, and lung cancer. Therefore, it is essential to establish a simple, innovative, fast, and reliable method for bisulfite identification in foodstuffs. In this research, a novel fluorescence method based on manganese oxide nanosheets and carbon dots is designed for bisulfite detection in food samples. Initially, manganese oxide nanosheets were synthesized via a bottom-up approach, and carbon dots are produced using a hydrothermal...
A method for automatic tuning the memristance of memristive devices with the capacity of applying to memristive memories
, Article 2012 International Conference on Computer Systems and Industrial Informatics, ICCSII 2012, 18 December 2012 through 20 December 2012 ; December , 2012 ; 9781467351577 (ISBN) ; Merrikh Bayat, F ; Mirebrahimi, N ; Sharif University of Technology
2012
Abstract
Memristor is the fourth fundamental passive circuit element which has potential applications in development of analog memristive memories, neuroscience, and brain simulation. In all of these applications the memristance of the device should be adjusted to the desired value, which is currently performed by trial and error. The aim of this paper is to propose a new method and develop a circuit for automatic adjustment of the memristance of memristive devices. The proposed method is based on the sliding mode control and numerical simulations show that it can be used for tuning the memristance of such devices with a high accuracy
The neuro-fuzzy computing system with the capacity of implementation on a memristor crossbar and optimization-free hardware training
, Article IEEE Transactions on Fuzzy Systems ; Vol. 22, Issue. 5 , 2014 , Pages 1272-1287 ; ISSN: 10636706 ; Merrikh-Bayat, F ; Shouraki, S. B ; Sharif University of Technology
2014
Abstract
In this paper, first we present a new explanation for the relationship between logical circuits and artificial neural networks, logical circuits and fuzzy logic, and artificial neural networks and fuzzy inference systems. This shows us that neural networks are working in the same way as logical circuits when the connection between them is through the fuzzy logic. However, themain difference between them is that logical circuits can be constructed without using any kind of optimization-based learning methods. Based on these results, we propose a new neuro-fuzzy computing system. As verified by simulation results, it can effectively be implemented on the memristor crossbar structure and...
Memristive fuzzy edge detector
, Article Journal of Real-Time Image Processing ; Vol. 9, issue. 3 , September , 2014 , pp. 479-489 ; Online ISSN: 1861-8219 ; Bagheri Shouraki, S ; Merrikh-Bayat, F ; Sharif University of Technology
2014
Abstract
Fuzzy inference systems always suffer from the lack of efficient structures or platforms for their hardware implementation. In this paper, we tried to overcome this difficulty by proposing a new method for the implementation of the fuzzy rule-based inference systems. To achieve this goal, we have designed a multi-layer neuro-fuzzy computing system based on the memristor crossbar structure by introducing a new concept called the fuzzy minterm. Although many applications can be realized through the use of our proposed system, in this study we only show how the fuzzy XOR function can be constructed and how it can be used to extract edges from grayscale images. One main advantage of our...
Memristor crossbar-based hardware implementation of fuzzy membership functions
, Article Proceedings - 2011 8th International Conference on Fuzzy Systems and Knowledge Discovery, FSKD 2011, 26 July 2011 through 28 July 2011 ; Volume 1 , July , 2011 , Pages 645-649 ; 9781612841816 (ISBN) ; Shouraki, S. B ; Merrikh Bayat, F ; Sharif University of Technology
2011
Abstract
In May 1, 2008, researchers at Hewlett Packard (HP) announced the first physical realization of a fundamental circuit element called memristor that attracted so much interest worldwide. This newly found element can easily be combined with crossbar interconnect technology which this new structure has opened a new field in designing configurable or programmable electronic systems. These systems in return can have applications in signal processing and artificial intelligence. In this paper, based on the simple memristor crossbar structure, we propose new and simple circuits for hardware implementation of fuzzy membership functions. In our proposed circuits, these fuzzy membership functions can...
A novel method in adaptive image enlargement
, Article Eurasip Journal on Advances in Signal Processing ; Volume 2012, Issue 1 , 2012 ; 16876172 (ISSN) ; Kafaie, G ; Ayremlou, A ; Marvasti, F ; Sharif University of Technology
2012
Abstract
This article introduces a new adaptive method for image interpolation. In order to obtain a high resolution (HR) image from its low resolution (LR) counterpart (original image), an interpolator function (array) is used, and the main focus of this manuscript is to formulate and define this function. By applying this interpolator function to each row and column of a LR image, it is possible to construct its HR counterpart. One of the main challenges of image interpolation algorithms is to maintain the edge structures while developing an HR image from the LR replica. The proposed approach overcomes this challenge and exhibits remarkable results at the image edges. The peak signal to noise ratio...
Voltammetric behavior and determination of trace amounts of omeprazole using an edge-plane pyrolytic graphite electrode
, Article Iranian Journal of Pharmaceutical Research ; Volume 14, Issue 2 , Spring , 2015 , Pages 465-471 ; 17350328 (ISSN) ; Ghalkhani, M ; Bayat, M ; Ghorbani Bidkorbeh, F ; Sharif University of Technology
Iranian Journal of Pharmaceutical Research
2015
Abstract
The voltammetric performance of edge-plane pyrolytic graphite (EPG) electrode via adsorptive stripping voltammetry was investigated for study of the electrochemical behavior of omeprazole (OMZ) in aqueous solution. The results revealed that the oxidation of OMZ is an irreversible pH-dependent process that proceeds with the transfer of one electron and one proton in an adsorption-controlled mechanism. The determination conditions, such as the pH values of the supporting electrolyte, accumulation time and scan rate were optimized. Simplicity, high reproducibility and low detection limit (3 nM) of the electrode response as well as wide linear range (0.01 to 4.0 µM) can be stated as significant...
Spatiotemporal registration and fusion of transthoracic echocardiography and volumetric coronary artery tree
, Article International Journal of Computer Assisted Radiology and Surgery ; Volume 16, Issue 9 , 2021 , Pages 1493-1505 ; 18616410 (ISSN) ; Behnam, H ; Fatemizadeh, E ; Faghihi Langroudi, T ; Bayat, F ; Sharif University of Technology
Springer Science and Business Media Deutschland GmbH
2021
Abstract
Purpose: Cardiac multimodal image fusion can offer an image with various types of information in a single image. Many coronary stenosis, which are anatomically clear, are not functionally significant. The treatment of such kind of stenosis can cause irreversible effects on the patient. Thus, choosing the best treatment planning depend on anatomical and functional information is very beneficial. Methods: An algorithm for the fusion of coronary computed tomography angiography (CCTA) as an anatomical and transthoracic echocardiography (TTE) as a functional modality is presented. CCTA and TTE are temporally registered using manifold learning. A pattern search optimization algorithm, using...
Using a memristor crossbar structure to implement a novel adaptive real-time fuzzy modeling algorithm
, Article Fuzzy Sets and Systems ; Volume 307 , 2017 , Pages 115-128 ; 01650114 (ISSN) ; Bagheri Shouraki, S ; Merrikh Bayat, F ; Gholami, M ; Sharif University of Technology
Elsevier B.V
2017
Abstract
Fuzzy techniques can be used for accurate and high-speed modeling as well as for the control of complex systems, but various challenging problems are usually encountered during their actual implementation. For example, the variable parameters need to be optimized iteratively during the training phase, where this process is inspired by crisp domain algorithms. However, in recent years, memristor-based structures have emerged as another promising method for implementing neural network structures and fuzzy algorithms. In this study, we propose a novel adaptive and real-time fuzzy modeling algorithm, which employs the active learning method concept to mimic the functionality of the brain's right...
Early detection of immunization: A study based on an animal model using 1H nuclear magnetic resonance spectroscopy
, Article Pakistan Journal of Biological Sciences ; Volume 14, Issue 3 , 2011 , Pages 195-203 ; 10288880 (ISSN) ; Arjmand, M ; Tafazzoli, M ; Ghohzadeh, A ; Pourfallah, F ; Sadeghi, S ; Mirzazadeh, R ; Mirkham, F ; Tahen, S ; Iravam, A ; Bayat, P ; Vahabi, F ; Sharif University of Technology
2011
Abstract
Vaccines require a period of at least three months for clinical trials, hence a method that can identify elicitation of immune response a few days after the first dose is a necessity. Evolutionary variable selections are modeling approaches for proper manipulation of available data which were used to set up an animal model for classification of time dependent 'HNMR metabolomic profiles and pattern recognition of fluctuations of metabolites in two groups of male rabbits. One group of rabbits was immunized with human red blood cells and the other used as control. Blood was obtained every 48 h from each rabbit for a period of six weeks and the serum monitored for antibodies and metabolites by...
Investigation of the scavenging mechanism of tyrosyl radical by hydroxybenzohydroxamic acid derivatives: A DFT study
, Article Computational and Theoretical Chemistry ; Volume 1018 , 2013 , Pages 35-44 ; 2210271X (ISSN) ; Fattahi, A ; Sharif University of Technology
2013
Abstract
The free radical scavenging activity of a series of hydroxybenzohydroxamic acid derivatives have been studied in gas phase, water and benzene environments, using the density functional theory. Different mechanisms of reactions have been considered: single electron transfer (SET), hydrogen atom transfer (HAT). Rate constants were determined to know if the radical scavenging activity of these compounds proceeds via an H-atom or an electron-transfer mechanism. Calculations showed that the presence of the adjacent hydroxyl groups on phenyl ring increases the radical stability through intramolecular hydrogen bonds. The calculated bond dissociation enthalpy (BDE) values for hydroxyl groups on...
A quantum chemical study on the OH radical quenching by natural antioxidant fisetin
, Article Journal of Physical Organic Chemistry ; Volume 30, Issue 11 , 2017 ; 08943230 (ISSN) ; Fattahi, A ; Sharif University of Technology
2017
Abstract
In this work, the antioxidant ability of fisetin was explored toward hydroxyl (•OH) radical in aqueous and lipid solution using density functional level of theory. Different reaction mechanisms have been studied: hydrogen atom transfer, single electron transfer followed by proton transfer, and radical adduct formation, and sequential proton loss electron transfer. Rate constants for all possible reaction sites have been calculated using conventional transition state theory in conjunction with the Collins-Kimball theory. Branching ratios for the different channels of reaction are reported for the first time. Results show that the reactivity of fisetin toward hydroxyl (•OH) radical takes place...
Influence of remote intramolecular hydrogen bonding on the acidity of hydroxy-1,4-benzoquinonederivatives: A DFT study
, Article Journal of Physical Organic Chemistry ; Volume 32, Issue 4 , 2019 ; 08943230 (ISSN) ; Fattahi, A ; Sharif University of Technology
John Wiley and Sons Ltd
2019
Abstract
In this study, the effects of the remote intramolecular hydrogen bonding on the acidity of hydroxy-1,4-benzoquinone derivatives have been investigated ab initio by employing density functional theory (DFT) methods. The computational studies were performed for both gas and solution (H 2 O, DMSO, and MeCN solutions) phases. Our results indicated that remote hydrogen bonding could play an important role in increasing the acidity of hydroxy-1,4-benzoquinone. Noncovalent interaction reduced density gradient (NCI-RDG) methods were used to visualize the attractive and repulsive interactions in the studied acids and their conjugate bases. Natural bond orbital (NBO) analysis was performed to confirm...
An optimal hybrid nuclear norm regularization for matrix sensing with subspace prior information
, Article IEEE Access ; Volume 8 , 2020 , Pages 130937-130946 ; Daei, S ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2020
Abstract
Matrix sensing refers to recovering a low-rank matrix from a few linear combinations of its entries. This problem naturally arises in many applications including recommendation systems, collaborative filtering, seismic data interpolation and wireless sensor networks. Recently, in these applications, it has been noted that exploiting additional subspace information might yield significant improvements in practical scenarios. This information is reflected by two subspaces forming angles with column and row spaces of the ground-truth matrix. Despite the importance of exploiting this information, there is limited theoretical guarantee for this feature. In this work, we aim to address this issue...
The free radical scavenging activity of lespedezacoumestan toward ˙OH radical: a quantum chemical and computational kinetics study
, Article Journal of Physical Organic Chemistry ; Volume 31, Issue 2 , February , 2018 ; 08943230 (ISSN) ; Fattahi, A ; Sharif University of Technology
John Wiley and Sons Ltd
2018
Abstract
The free radical activity of lespedezacoumestan was investigated toward hydroxyl (˙OH) radical in polar and nonpolar media using density functional theory. Four reaction mechanisms including radical adduct formation, hydrogen atom transfer, sequential single electron-proton transfer (SET-PT), and sequential proton loss electron transfer were considered. The rate constants and branching ratio for all possible sites of reaction were calculated and reported for the first time. According to the obtained results, lespedezacoumestan reacts faster with ˙OH radical in aqueous solution than in nonpolar media. Also, lespedezacoumestan is an excellent ˙OH radical scavenger regardless of the environment...
Transfer of d -level quantum states through spin chains by random swapping
, Article Physical Review A - Atomic, Molecular, and Optical Physics ; Volume 75, Issue 2 , 2007 ; 10502947 (ISSN) ; Karimipour, V ; Sharif University of Technology
2007
Abstract
We generalize an already proposed protocol for quantum state transfer to spin chains of arbitrary spin. An arbitrary unknown d -level state is transferred through a chain with rather good fidelity by the natural dynamics of the chain. We compare the performance of this protocol for various values of d. A by-product of our study is a much simpler method for picking up the state at the destination as compared with the one proposed previously. We also discuss entanglement distribution through such chains and show that the quality of entanglement transition increases with the number of levels d. © 2007 The American Physical Society
Separating radar signals from impulsive noise using atomic norm minimization
, Article IEEE Transactions on Circuits and Systems II: Express Briefs ; Volume 68, Issue 6 , 2021 , Pages 2212-2216 ; 15497747 (ISSN) ; Daei, S ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2021
Abstract
We consider the problem of corrupted radar super-resolution, a generalization of compressed radar super-resolution in which one aims to recover the continuous-valued delay-Doppler pairs of moving objects from a collection of corrupted and noisy measurements. The received signal in this type consists of contributions from objects, outlier and noise. While this problem is ill-posed in general, tractable recovery is possible when both the number of objects and corrupted measurements are limited. In this brief, we propose an atomic norm optimization in order to find the delay-Doppler pairs and the outlier signal. The objective function of our optimization problem encourages both sparsity in the...