Search for: dynamic-range
Total 34 records
The Analysis of HDR Video Reconstruction Methods, M.Sc. Thesis Sharif University of Technology ; Amini, Arash
The conventional cameras and displays do not have the ability to record and display the full brightness of the world around us. These deficiencies have led to the development of methods known as High Dynamic Range Imaging. Most of the work done in this field falls into two groups: compression of the light range and its expansion. In compression, the brightness range is intended to display content with a high dynamic range in simple displays. But the goal of expanding the brightness range is to reconstruct HDR content from a low dynamic range one. In addition to the above classification, this field is also categorized based on the type of content (image or video). In this study, the...
HDR Image Reconstruction from a Single-Exposure LDR Image, M.Sc. Thesis Sharif University of Technology ; Amini, Arash ; Mohammadzadeh, Nargesolhoda
High dynamic range (HDR) images provide more realistic experience in displaying real-world scenes than conventional low dynamic range (LDR) images by providing much more detailed luminance information; However, most imaging content is still available in low dynamic range. Inverse tonemapping is known as the problem of inferring an HDR image from a single-exposure LDR image in which the lost data caused by saturation of bright parts and quantization must be reconstructed.To address this problem, in this thesis, two fully-automatic architectures based on convolutional neural networks, are proposed. Both these architectures utilize a number of convolutional auto-encoders as...
A study of hyperelastic models for predicting the mechanical behavior of extensor apparatus, Article Biomechanics and Modeling in Mechanobiology ; Volume 16, Issue 3 , 2017 , Pages 1077-1093 ; 16177959 (ISSN) ; Karimi Taheri, K ; Narooei, K ; Karimi Taheri, A ; Sharif University of Technology
Springer Verlag 2017
In this research, the nonlinear elastic behavior of human extensor apparatus was investigated. To this goal, firstly the best material parameters of hyperelastic strain energy density functions consisting of the Mooney–Rivlin, Ogden, invariants, and general exponential models were derived for the simple tension experimental data. Due to the significance of stress response in other deformation modes of nonlinear models, the calculated parameters were used to study the pure shear and balance biaxial tension behavior of the extensor apparatus. The results indicated that the Mooney–Rivlin model predicts an unstable behavior in the balance biaxial deformation of the extensor apparatus, while the...
Design and implementation of a high dynamic range C band down-converter, Article Progress in Electromagnetics Research Letters ; Volume 31 , 2012 , Pages 25-33 ; 19376480 (ISSN) ; Tavakoli, Z ; Sharif University ot Technology
PIER Letters 2012
A technique that expands dynamic range (DR) of frequency down-converters in the C band frequency is presented. Primary characteristics of down-converter are evaluated to confirm that it can be used in microwave receivers. The C band down-converter is carried out by the combination of RF mixers, band pass interdigital filter, and X band combline filter which are designed entirely for this project. Attainment of the perfect receiver is the final purpose of this paper, and a method that causes 72 dB dynamic range, high tangential signal sensitivity and fine gain flatness is used for achieving the mentioned purpose. These efforts improve the dynamic range about 19 dB and gain flatness about 3.07...
Performance characterization of a low-cost dual-channel camera-based microarray scanner, Article 24th Iranian Conference on Electrical Engineering, ICEE 2016, 10 May 2016 through 12 May 2016 ; 2016 , Pages 1534-1538 ; 9781467387897 (ISBN) ; Ghobeh, M ; Ghiasvand, E ; Akbari Roshan, K ; Motahari, S. A ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc 2016
In this paper, we have proposed, designed, implemented, and characterized a low-cost camera-based microarray scanner which is capable of imaging fluorescently-labeled DNA or Protein microarrays. The proposed system is designed to simultaneously measure two different fluorescent dyes using two parallel channels which increase the overall scan speed. We have shown that the wide dynamic range of system makes it able to detect fluorophore densities from 100-106 molecule/μm2. In each capture, a 5.6 mm × 3.7 mm field is imaged on a 22.3 mm × 14.9 mm (18 megapixels) CMOS sensor. Therefore, the microarray can be scanned with ∼ 1μm2 spatial resolution which is high enough to distinguish borders of...
A wide dynamic range low power 2× time amplifier using current subtraction scheme, Article 2016 IEEE International Symposium on Circuits and Systems, ISCAS 2016, 22 May 2016 through 25 May 2016 ; Volume 2016-July , 2016 , Pages 462-465 ; 02714310 (ISSN); 9781479953400 (ISBN) ; Khorami, A ; Hajsadeghi, K ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc 2016
The most challenging issue of conventional Time Amplifiers (TAs) is their limited Dynamic Range (DR). This paper presents a mathematical analysis to clarify principle of operation of conventional 2× TA's. The mathematical derivations release strength reduction of the current sources of the TA is the simplest way to increase DR. Besides, a new technique is presented to expand the Dynamic Range (DR) of conventional 2× TAs. Proposed technique employs current subtraction in place of changing strength of current sources using conventional gain compensation methods, which results in more stable gain over a wider DR. The TA is simulated using Spectre-rf in TSMC 0.18um COMS technology. DR of the 2×...
An enhanced dynamic range low-power delta-sigma modulator for portable voice band applications, Article 2003 Southwest Symposium on Mixed-Signal Design, SSMSD 2003, 23 February 2003 through 25 February 2003 ; 2003 , Pages 263-268 ; 0780377788 (ISBN); 9780780377783 (ISBN) ; Aslanzadeh, H. A ; Mehrmanesh, S ; Vahidfar, M. B ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc 2003
A new second order sigma delta modulator with the reduced number of op-amps, to decrease static power consumption and area, is presented for voice band applications such as codecs. This switched capacitor modulator uses reused capacitor technique to reduce the input thermal noise and circuit area. It improves the DR of modulator by almost 0.5 bit. The modulator shows 87 dB DR for voice band while consuming 125 μW from a 2.5 V supply. © 2003 IEEE
A 1.8V high dynamic range CMOS Gm-c filter for portable video systems, Article 14th International Conference on Microelectronics, ICM 2002, 11 December 2002 through 13 December 2002 ; Volume 2002-January , 2002 , Pages 38-41 ; 0780375734 (ISBN) ; Aslanzadeh, H. A ; Vahidfar, M. B ; Atarodi, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc 2002
A 4th order, 5 MHz, lowpass Butterworth Gm-c filter has been combined with a low noise low-voltage amplifier to form a lowpass filter for video applications. In this filter an improved transconductor and a powerful method is used to adjust the transconductance gain for tuning application. A continuous variable gain current-to-current converter is used to tune the transconductor value. The THD of the filter is -77 dB for 1 Vppd input signal. Input referred noise is 40 nV/√Hz in the worst case. All the circuits are designed based on a 0.25 μm CMOS process technology with a single 1.8 V supply. © 2002 IEEE
Beamforming, null-steering, and simultaneous spatial and frequency domain filtering in integrated phased array systems, Article AEU - International Journal of Electronics and Communications ; Volume 110 , 2019 ; 14348411 (ISSN) ; Atarodi, S. M ; Sharif University of Technology
Elsevier GmbH 2019
In the case that phased array systems are not capable of attenuating interferences, Radio Frequency (RF) front-ends and Analog Digital Converters (ADCs) with a large dynamic range are required to avoid saturation of the receiver. This leads to a higher power consumption. In this paper, employing N-path circuits in Mixer-First receivers, a novel method is introduced in which spatial and frequency blockers are eliminated right before entering the system on the antennas input. In fact using this technique, adjustable spatial notch filter and band-pass frequency filter are implemented to suppress spatial and frequency interferences. The proposed method enhances the robustness and effectiveness...
Porous eco–friendly fibers for on–line micro solid–phase extraction of nonsteroidal anti–inflammatory drugs from urine and plasma samples, Article Journal of Chromatography A ; Volume 1574 , 2018 , Pages 18-26 ; 00219673 (ISSN) ; Behkami, S ; Bagheri, H ; Sharif University of Technology
Elsevier B.V 2018
In this study, cellulose acetate (CA) fibers were prepared using different solvent systems in electrospinning. The recorded scanning electron microscopy micrographs indicated that the morphology of the prepared fibers is closely associated with the type of electrospinning solvents. The prepared CA fibers were used as an extractive phase for on–line micro–solid phase extraction (μ-SPE) of nonsteroidal–inflammatory drugs (NSAIDs) in biological samples pursued by HPLC–UV determination. Work conducted on this research ascertained that the use of dichloromethane:acetone (3:1, v/v) solvent system in the CA dissolution for electrospinning, leads to the formation of porous ribbon–like fibers and...
Design and fabrication of an electrochemical aptasensor using Au nanoparticles/carbon nanoparticles/cellulose nanofibers nanocomposite for rapid and sensitive detection of Staphylococcus aureus, Article Bioelectrochemistry ; Volume 123 , 2018 , Pages 70-76 ; 15675394 (ISSN) ; Shahrokhian, S ; Sharif University of Technology
Elsevier B.V 2018
Since that pathogenic bacteria are major threats to human health, this paper describes the fabrication of an effective and durable sensing platform based on gold nanoparticles/carbon nanoparticles/cellulose nanofibers nanocomposite (AuNPs/CNPs/CNFs) at the surface of glassy carbon electrode for sensitive and selective detection of Staphylococcus aureus (S. aureus). The AuNPs/CNPs/CNFs nanocomposite with the high surface area, excellent conductivity, and good biocompatibility was used for self-assembled of the thiolated specific S. aureus aptamer as a sensing element. The surface morphology of AuNPs/CNPs/CNFs nanocomposite was characterized with field emission scanning electron microscopy...
Amine modified magnetic polystyrene for extraction of drugs from urine samples, Article Journal of Chromatography A ; Volume 1602 , 2019 , Pages 107-116 ; 00219673 (ISSN) ; Maleki, M ; Bagheri, H ; Sharif University of Technology
Elsevier B.V 2019
Polystyrene is one of the best candidates as the extracting medium due to its high stability in different media and acceptable extraction capability. However, the hydrophobic nature and low wettability of polystyrene limits its application to non–polar analytes. To resolve this limitation, in this project, amine groups were chemically attached to the surface of magnetic polystyrene. The resulting hydrophilic magnetic particles were expected to be capable of extracting both polar and non–polar analytes. Non–steroidal anti–inflammatory drugs (NSAIDs) were chosen for testing the applicability of modified magnetic polystyrene according to the importance of their analysis and also their wide...
The geometrical characteristics of nickel-based metal organic framework on its entrapment capability, Article Journal of Chromatography A ; Volume 1610 , 2020 ; Abbasi, A ; Bagheri, H ; Sharif University of Technology
Elsevier B.V 2020
Here, a three dimensional nickel–based metal organic framework (MOF) was synthesized via solvothermal and room temperature protocols. In order to study the effects of the synthesis conditions on the physical properties such as pore sizes and shapes of the prepared MOFs, their extraction capabilities were examined. Both MOFs were characterized by Fourier transform infrared spectroscopy, powder X-ray diffraction, scanning electron microscopy, Brunauer–Emmett–Teller and thermogravimetric analyses. Brilliant properties such as porous structure, high surface area and considerable thermal stability make them reasonable candidates to be employed as efficient extractive phases. The efficiency of the...
Electrocatalytic oxidation and nanomolar determination of guanine at the surface of a molybdenum (VI) complex-TiO2 nanoparticle modified carbon paste electrode, Article Journal of Electroanalytical Chemistry ; Volume 624, Issue 1-2 , 2008 , Pages 73-78 ; 15726657 (ISSN) ; Taleat, Z ; Beitollahi, H ; Salavati Niasari, M ; Mirjalili, B. B. F ; Taghavinia, N ; Sharif University of Technology
A modified carbon paste electrode was prepared by incorporating TiO2 nanoparticles with bis[bis(salicylidene-1,4-phenylenediamine)molybdenum(VI)]. A mixture of fine graphite powder with 4 wt% of TiO2 nanoparticles was applied for the preparation of the carbon paste (by dispersing in paraffin) and finally modified with a molybdenum (VI) complex. The electrocatalytic oxidation of guanine (G) was investigated on the surface of the molybdenum (VI) complex-TiO2 nanoparticle modified carbon paste electrode (MCTNMCPE) using cyclic voltammetry (CV), differential pulse voltammetry (DPV), chronoamperometry (CHA) and chronocoloumetry (CHC). Using the modified electrode, the kinetics of G...
Construction of Pt nanoparticle-decorated graphene nanosheets and carbon nanospheres nanocomposite-modified electrodes: Application to ultrasensitive electrochemical determination of cefepime, Article RSC Advances ; Volume 4, Issue 15 , 2014 , Pages 7786-7794 ; ISSN: 20462069 ; Hosseini Nassab, N ; Ghalkhani, M ; Sharif University of Technology
A novel ultrasensitive modified electrode was fabricated with a graphene nanosheets and carbon nanospheres (GNS-CNS)-based nanocomposite film as a powerful platform. Pt nanoparticles (PtNPs) were simply electrodeposited onto the GNS-CNS-coated glassy carbon electrode creating a PtNPs/GNS-CNS hybrid nanocomposite modified electrode. Scanning electron microscopy, energy dispersive X-ray spectroscopy and linear sweep voltammetry (LSV) techniques were used for the characterization of the prepared modified electrode. The results of investigation of electrochemical response characteristics of cefepime (CP) revealed a considerable improvement in the oxidation peak current of CP on PtNPs/GNS-CNS/GCE...
Comparison of two triple-fiber sensor designs for small distance measurements, Article Microwave and Optical Technology Letters ; Vol. 56, issue. 9 , JUN , 2014 , pp. 1997-2001 ; ISSN: 08952477 ; Sharif University of Technology
Operation of two different optical fiber sensor designs for distance measurements with a good sensitivity, resolution, and wide dynamic range is reported. Design is based on the intensity modulation due to reflectance measurement from a target surface. Two reported designs are fabricated with a triple-fiber assembly, in which one uses a double-transmitter, while another one uses a double-receiver fiber design. Reflection signals from different targets are tested with these sensors and results for the mirror and A4 paper surfaces are described. The response curve for both experiments starts from a near zero level, shows a maximum at a certain distance and gradually drops to the background...
Two-dimensional multi-parameter adaptation of noise, linearity, and power consumption in wireless receivers, Article IEEE Transactions on Circuits and Systems I: Regular Papers ; Vol. 61, issue. 8 , July , 2014 , p. 2433-2443 ; Sharif Bakhtiar, M ; Sharif University of Technology
This paper presents a general method for real-time adaptation of wireless receivers according to the prevailing reception conditions. In order to maintain the desired signal quality at the minimum possible power dissipation, the method performs an optimal trade-off between noise, linearity, and power consumption in the building blocks of the receiver. This is achieved by continuously monitoring the signal-to-noise plus interference ratio (SNIR) and accordingly tuning the adaptation parameters embedded in the receiver design. A prototype DVB-H receiver chip, implemented in a standard 0.18-μ m CMOS process, is used as the test vehicle. By properly trading noise with linearity in the receiver,...
Adaptive filtering techniques in passive radar, Article Proceedings International Radar Symposium, Dresden ; Volume 2 , June , 2013 , Pages 1067-1078 ; 21555753 (ISSN) ; 9783954042234 (ISBN) ; Radmard, M ; Majd, M. N ; Nayebi, M. M ; Sharif University of Technology
One of the most important obstacles in passive radar applications is removing the direct signal from the target channel. Otherwise, week echoes from the targets in the target channel would be ignored due to the limited dynamic range of the system. One of the most effective techniques in this field is using adaptive filters. In this paper various adaptive filters are introduced and their performances are shown and compared
Construction of a modified carbon paste electrode based on TiO2 nanoparticles for the determination of gallic acid, Article Journal of Solid State Electrochemistry ; Volume 17, Issue 1 , 2013 , Pages 157-165 ; 14328488 (ISSN) ; Nami Ana, S. F ; Hashemnia, S ; Hormozi Nezhad, M. R ; Sharif University of Technology
A modified carbon paste electrode was prepared by incorporating the TiO2 nanoparticles in the carbon paste matrix. The electrochemical behavior of gallic acid (GA) is investigated on the surface of the electrode using cyclic voltammetry and differential pulse voltammetry. The surface morphology of the prepared electrode was characterized using the scanning electron microscopy. The results indicate that the electrochemical response of GA is improved significantly at the modified electrode compared with the unmodified electrode. Furthermore, the capabilities of electron transfer on these two electrodes were also investigated by electrochemical impedance spectroscopy. Under the optimized...
Electrochemical determinations of 6-mercaptopurine on the surface of a carbon nanotube-paste electrode modified with a cobalt salophen complex, Article Journal of Solid State Electrochemistry ; Volume 16, Issue 4 , April , 2012 , Pages 1643-1650 ; 14328488 (ISSN) ; Ghorbani Bidkorbeh, F ; Mohammadi, A ; Dinarvand, R ; Sharif University of Technology
A mixture of multi-walled carbon nanotube/graphite paste electrode modified with a salophen complex of cobalt was prepared and was applied for the study of the electrochemical behavior of 6-mercaptopurine (MP) using cyclic and differential pulse voltammetry (DPV). An excellent electrocatalytic activity toward the oxidation of MP was achieved, which led to a considerable lowering in the anodic overpotential and remarkable increase in the response sensitivity in comparison with unmodified electrode. Utilizing DPV method, a linear dynamic range of 1-100 μM with detection limit of 0.1 μM was obtained in phosphate buffer of pH 3.0. The electrochemical detection system was very stable, and the...