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Classification of vascular function in upper limb using bilateral photoplethysmographic signals
, Article Physiological Measurement ; Volume 29, Issue 3 , 2008 , Pages 365-374 ; 09673334 (ISSN) ; Zahedi, E ; Jajai, H. M ; Sharif University of Technology
2008
Abstract
Bilateral PPG signals have been used for comparative study of two groups of healthy (free from any cardiovascular risk factors) and diabetic (as cardiovascular disease risk group) subjects in the age-matched range 40-50 years. The peripheral blood pulsations were recorded simultaneously from right and left index fingers for 90 s. Pulses have been modeled with the ARX440 model in the interval of 300 sample points with 100 sample points overlap between segments. Model parameters of three segments based on the highest fitness (higher than 80%) of modeled segments were retained for each subject. Subsequently, principal component analysis (PCA) was applied to the parameters of retained segments...
Evaluation of seismic performance factors for tension-only braced frames
, Article Steel and Composite Structures ; Volume 35, Issue 4 , 2020 , Pages 599-609 ; Lagzian, M ; Maleki, S ; Shariati, A ; Trung, N. T ; Sharif University of Technology
Techno Press
2020
Abstract
The tension-only braced frames (TOBFs) are widely used as a lateral force resisting system (LFRS) in low-rise steel buildings due to their simplicity and economic advantage. However, the system has poor seismic energy dissipation capacity and pinched hysteresis behavior caused by early buckling of slender bracing members. The main concern in utilizing the TOBF system is the determination of appropriate performance factors for seismic design. A formalized approach to quantify the seismic performance factor (SPF) based on determining an acceptable margin of safety against collapse is introduced by FEMA P695. The methodology is applied in this paper to assess the SPFs of the TOBF systems. For...
Intelligent control of an IPMC actuated manipulator using emotional learning-based controller
, Article Metamaterials: Fundamentals and Applications, San Diego, CA, 10 August 2008 through 13 August 2008 ; Volume 7029 , 2008 ; 0277786X (ISSN) ; 9780819472496 (ISBN) ; Meghdari, A ; Shariati, P ; Sharif University of Technology
2008
Abstract
In this research an intelligent emotional learning controller, Takagi- Sugeno- Kang (TSK) is applied to govern the dynamics of a novel Ionic-Polymer Metal Composite (IPMC) actuated manipulator. Ionic-Polymer Metal Composites are active actuators that show very large deformation in existence of low applied voltage. In this research, a new IPMC actuator is considered and applied to a 2-dof miniature manipulator. This manipulator is designed for miniature tasks. The control system consists of a set of neurofuzzy controller whose parameters are adapted according to the emotional learning rules, and a critic with task to assess the present situation resulted from the applied control action in...
Dynamic modeling and sensitivity analysis of atomic force microscope pushing force in nanoparticle manipulation on a rough substrate [electronic resource]
, Article Journal of Advanced Science, Engineering and Medicine ; 2013, Vol. 5, pp. 1-10 ; Mahboobi, Seyed Hanif ; Meghdari, Ali ; Sharif University of Technology
Abstract
An Atomic Force Microscope (AFM) is a capable tool to manipulate nanoparticles by exerting pushing force on the nanoparticles located on the substrate. In reality, the substrate cannot be considered as a smooth surface particularly at the nanoscale. Hence, the particle may encounter a step on the substrate during a manipulation. In this study, dynamics of the nanoparticle on a stepped substrate and critical pushing force in the manipulation are investigated. There are two possible dynamic modes that may happen in the manipulation on the stepped substrate. In one mode, the nanoparticle may slide on the step edge and then climb up to the step which is a desired mode. Another possible mode is...
Alkali-activated slag (AAS) paste: Correlation between durability and microstructural characteristics
, Article Construction and Building Materials ; Volume 267 , 2021 ; 09500618 (ISSN) ; Shariati, A ; Trung, N. T ; Shoaei, P ; Ameri, F ; Bahrami, N ; Zamanabadi, S. N ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
This study was aimed at evaluating the effects of alkali activator solution and utilization of silica fume (SF) on durability and microstructural characteristics of alkali-activated ground granulated blast furnace slag (GGBFS) pastes. The pastes were activated with sodium silicate (SS) blended with NaOH (SH) solution with molar concentrations of 8 M, 12 M, and 16 M and SS:SH ratios of 1.0, 2.5, and 4.0. The same mixes were prepared with SF as partial replacement of GGBFS at a dosage of 10% by weight. The initial and final water absorption as well as the electrical resistivity of the specimens were measured. The optimal paste fabricated with 12 M NaOH solution and SS:SH ratio of 2.5 showed...
Behavior of tilted angle shear connectors
, Article PLoS ONE ; Volume 10, Issue 12 , December , 2015 ; 19326203 (ISSN) ; Maleki, S ; Shariati, M ; Ramli Sulong, N. H ; Sharif University of Technology
Public Library of Science
2015
Abstract
According to recent researches, angle shear connectors are appropriate to transfer longitudinal shear forces across the steel-concrete interface. Angle steel profile has been used in different positions as L-shaped or C-shaped shear connectors. The application of angle shear connectors in tilted positions is of interest in this study. This study investigates the behaviour of tilted-shaped angle shear connectors under monotonic loading using experimental push out tests. Eight push-out specimens are tested to investigate the effects of different angle parameters on the ultimate load capacity of connectors. Two different tilted angles of 112.5 and 135 degrees between the angle leg and steel...
The ITO-capped WO3 nanowires biosensor based on field-effect transistor in label-free protein sensing
, Article Applied Physics A: Materials Science and Processing ; Volume 123, Issue 5 , 2017 ; 09478396 (ISSN) ; Sharif University of Technology
Springer Verlag
2017
Abstract
The fabrication of ITO-capped WO3 nanowires associated with their bio-sensing properties in field-effect transistor diagnostics basis as a biosensor has been reported. The bio-sensing property for manipulated nanowires elucidated that the grown nanostructures were very sensitive to protein. The ITO-capped WO3 nanowires biosensor showed an intensive bio-sensing activity against reliable protein. Polylysine strongly charged bio-molecule was applied as model system to demonstrate the implementation of materialized biosensor. The employed sensing mechanism was ‘label-free’ and depended on bio-molecule’s intrinsic charge. For nanowires synthesis, the vapor–liquid–solid mechanism was used....
The field effect transistor DNA biosensor based on ITO nanowires in label-free hepatitis B virus detecting compatible with CMOS technology
, Article Biosensors and Bioelectronics ; Volume 105 , 15 May , 2018 , Pages 58-64 ; 09565663 (ISSN) ; Sharif University of Technology
Elsevier Ltd
2018
Abstract
In this paper the field-effect transistor DNA biosensor for detecting hepatitis B virus (HBV) based on indium tin oxide nanowires (ITO NWs) in label free approach has been fabricated. Because of ITO nanowires intensive conductance and functional modified surface, the probe immobilization and target hybridization were increased strongly. The high resolution transmission electron microscopy (HRTEM) measurement showed that ITO nanowires were crystalline and less than 50 nm in diameter. The single-stranded hepatitis B virus DNA (SS-DNA) was immobilized as probe on the Au-modified nanowires. The DNA targets were measured in a linear concentration range from 1fM to 10 µM. The detection limit of...
Alkali-activated slag (AAS) paste: Correlation between durability and microstructural characteristics
, Article Construction and Building Materials ; 2020 ; Shariati, A ; Trung, N. T ; Shoaei, P ; Ameri, F ; Bahrami, N ; Narimani Zamanabadi, S ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
This study was aimed at evaluating the effects of alkali activator solution and utilization of silica fume (SF) on durability and microstructural characteristics of alkali-activated ground granulated blast furnace slag (GGBFS) pastes. The pastes were activated with sodium silicate (SS) blended with NaOH (SH) solution with molar concentrations of 8 M, 12 M, and 16 M and SS:SH ratios of 1.0, 2.5, and 4.0. The same mixes were prepared with SF as partial replacement of GGBFS at a dosage of 10% by weight. The initial and final water absorption as well as the electrical resistivity of the specimens were measured. The optimal paste fabricated with 12 M NaOH solution and SS:SH ratio of 2.5 showed...
VoIP users’ Quality of Experience (QoE)Evaluation
, Ph.D. Dissertation Sharif University of Technology ; Jahangir, Amir Hossein (Supervisor)
Abstract
Quality of Experience (QoE) indicates the overall quality of one service such as Voice over IP (VoIP) from users' point of view by considering several systems, human, and contextual factors. QoE measurement and prediction are more challenging than Quality of Service (QoS) which is only related to network parameters. There exist various objective and subjective methods for QoE prediction. This research investigates various features affecting QoE by proposing a comprehensive subjective evaluation by employing a large number of users. We show that many unconsidered factors including speaker specifications and signal properties, such as signal-to-noise ratio (SNR), can affect QoE so that the SNR...
Selecting dryer type using fuzzy logic
, Article CHISA 2006 - 17th International Congress of Chemical and Process Engineering, Prague, 27 August 2006 through 31 August 2006 ; 2006 ; 8086059456 (ISBN); 9788086059457 (ISBN) ; Sharif University of Technology
2006
Abstract
Due to variety of industrial dryers and also importance of selecting appropriate dryer to achieve the required quality of product as well as considering economical aspects, using methods and algorithms which take all effective factors into account and present the best selection is regarded by engineers and researchers. In this paper selection of dryer applying fuzzy logic is presented and the advantages of this method are investigated. For this a program is written using MATLAB programming software and its result compared with real cases. It has been found that there is a good agreement between the prepared program results and industrial experiences. Selection of dryer for a specific...
Shear capacity of C-shaped and L-shaped angle shear connectors
, Article PLoS ONE ; Volume 11, Issue 8 , 2016 ; 19326203 (ISSN) ; Maleki, S ; Shariati, M ; Ramli Sulong, N. H ; Tahir, M. M ; Sharif University of Technology
Public Library of Science
2016
Abstract
This paper investigates the behaviour of C-shaped and L-shaped angle shear connectors embedded in solid concrete slabs. An effective finite element model is proposed to simulate the push out tests of these shear connectors that encompass nonlinear material behaviour, large displacement and damage plasticity. The finite element models are validated against test results. Parametric studies using this nonlinear model are performed to investigate the variations in concrete strength and connector dimensions. The finite element analyses also confirm the test results that increasing the length of shear connector increases their shear strength proportionately. It is observed that the maximum stress...
Toward a comprehensive subjective evaluation of VoIP users’ quality of experience (QoE): a case study on Persian language
, Article Multimedia Tools and Applications ; Volume 80, Issue 21-23 , 2021 , Pages 31783-31802 ; 13807501 (ISSN) ; Jahangir, A. H ; Hosseini, S. M ; Sharif University of Technology
Springer
2021
Abstract
Quality of Experience (QoE) measures the overall quality of a service from users’ point of view by considering several system, human, and contextual factors. There exist various objective and subjective methods for QoE prediction. Although the subjective approach is more expensive and challenging than the objective approach, QoE’s level can be more accurately determined by a subjective test. This paper investigates various features affecting QoE by proposing a comprehensive subjective evaluation. First, we show that many unconsidered factors can significantly affect QoE. We have generated voice samples featuring different values for novel factors related to the speaker, signal, and network....
The laser-assisted field effect transistor gas sensor based on morphological zinc-excited tin-doped in2o3 nanowires
, Article Surface Review and Letters ; Volume 24, Issue 8 , 2017 ; 0218625X (ISSN) ; Khosravinejad, F ; Sharif University of Technology
2017
Abstract
The gas nanosensor of indium oxide nanowires in laser assisted approach, doped with tin and zinc for gas sensing and 1D growth purposes respectively, was reported. The nanowires were very sensitive to H2S gas in low concentration of 20 ppb gas at room temperature. The fast dynamic intensive and sensitive response to gas was in a few seconds with an on/off sensitivity ratio of around 10. The square cross-section indium oxide nanowires were fabricated through physical vapor deposition (PVD) mechanism and annealing approach. The field emission scanning electron microscopy (FESEM) observations indicated that the annealing temperature was vital in nanostructures' morphology. The fabricated...
Exergy analysis of waste heat recovery section in steam-natural gas reforming process
, Article Energy and Fuels ; Volume 29, Issue 5 , April , 2015 , Pages 3322-3327 ; 08870624 (ISSN) ; Farhadi, F ; Sharif University of Technology
American Chemical Society
2015
Abstract
In this work, an exergy analysis is performed for the waste heat recovery section (WHRS) of the steam-natural gas reforming (SNGR) process as a major energy intensive process. Two alternate conditions are investigated to evaluate the required thermodynamic parameters: normal operating condition and increase of C2 + components in the process feed stream. At normal operating condition, the exergy efficiency of WHRS amounts to 0.58 while some 17.2 kJ energy is destructed for each mole of H2 produced. If heavier than methane components are increased in the feed up to 8.5 mole %, despite the increase of H2 production, the exergy efficiency decreases down to 0.54...
Prediction of Rolling Element Bearings Degradation Trend Using Limited Data
, M.Sc. Thesis Sharif University of Technology ; Behzad, Mehdi (Supervisor) ; Arghand, Hesam Al-din (Co-Supervisor)
Abstract
Condition monitoring of machinery is of significant economic importance to mitigate production losses resulting from downtimes. Unforeseen failure of roller element bearings is the most common issue observed in industrial units. However, detecting and tracking the progression of these failures through machine vibration monitoring and predicting the deterioration of these rotating components are viable solutions. Numerous studies have focused on using laboratory accelerated life test data for fault detection and remaining useful life prediction of these components. While online monitoring of all equipment in the industry may not be feasible, and conditions in the field differ from laboratory...
Intelligent Fault Diagnosis using Multiple Sensor Data Fusion for Detecting Misalignment and Unbalance
, M.Sc. Thesis Sharif University of Technology ; Behzad, Mehdi (Supervisor) ; Arghand, Hesam Al-Din (Co-Supervisor)
Abstract
Intelligent predictive maintenance is recognized as a cornerstone of Industry 4.0, where intelligent software is employed for the early detection of faults and the prevention of unexpected failures. Recent research indicates that the integration of multi-sensor data for fault diagnosis of gearboxes and bearings, using artificial intelligence models, has been successful. However, conventional methods face several challenges. These include an over-reliance on the signal characteristics of a single sensor and the impracticality of applying intelligent learning methods, particularly deep learning, despite their high potential, due to the unavailability of sufficiently large and diverse...
Thermal degradation behavior and kinetic analysis of ultra high molecular weight polyethylene based multi-walled carbon nanotube nanocomposites prepared via in-situ polymerization
, Article Journal of Macromolecular Science, Part A: Pure and Applied Chemistry ; Volume 49, Issue 9 , 2012 , Pages 749-757 ; 10601325 (ISSN) ; Saadatabadi, A. R ; Khorasheh, F ; Sharif University of Technology
T&F
2012
Abstract
Thermal degradation behavior of multi-wall carbon nanotubes (MWCNTs)/ultra high molecular weight polyethylene (UHMWPE) nanocomposites, with different nanotubes contents (0.5, 1.5 and 3.5 wt%) prepared via in-situ polymerization technique have been investigated using thermal gravimetric analysis (TGA). TGA spectra revealed that these nanocomposites had enhanced thermal stability and no significant mass loss (<0.4 wt%) occurred up to 350°C. Thermal degradation of these UHMWPE/MWCNT nanocomposites was investigated in terms of parameters such as the onset temperature of degradation (T 10), the decomposition temperature at 50% wt loss (T 50), the degradation temperature of maximum rate of the...
Clock feed-through analysis in switched-capacitor integrator transmission gates switches
, Article 2009 6th International Conference on Electrical Engineering/Electronics, Computer, Telecommunications and Information Technology, ECTI-CON 2009, Chonburi, 6 May 2009 through 9 May 2009 ; Volume 1 , 2009 , Pages 500-503 ; 9781424433889 (ISBN) ; Torkzadeh, P ; Shariati Samani, S ; Sharif University of Technology
2009
Abstract
Sigma-Delta modulator ADCs used in signal processing applications are usually implemented by switched-capacitor (SC) circuits and CMOS transmission gates. Clock feed-through effect is one of the main non-ideal parameters existing in SC integrators degrading modulator total SNDR and its linearity. In this paper, a comprehensive analysis of clock feed-through effect on CMOS transmission gates on both rising and falling edges on output node will be presented. The main interferer parameters such as clock signal timing model, input signal level and switch parameters effect on output error will be analyzed. Finally, circuit simulations using 0.18um CMOS technology in ADS environment show the...
Exergy Analysis on Design of SMR Preheating Exchangers
, M.Sc. Thesis Sharif University of Technology ; Farhadi, Fathollah (Supervisor)
Abstract
With the global oil price increase in recent years and fossil fuel resource scarcity, analyzing of fossil fuel consumer industries and optimization of their fuel consumption is an important rule. Exergy analysis is an efficient tool for this purpose in the chemical and petrochemical processes in recent years more than ever. Therefore, in this work, an exergy analysis is performed for heat recovery section of Steam-Methane Reforming (SMR) process as a major consumer of natural gas.
This work contains five general section. At the first section, exergy and energy concepts, reforming processes and other related basic concepts are described. The second section is about the recent research and...
This work contains five general section. At the first section, exergy and energy concepts, reforming processes and other related basic concepts are described. The second section is about the recent research and...