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A low-cost fault-tolerant technique for carry look-ahead adder
, Article 2009 15th IEEE International On-Line Testing Symposium, IOLTS 2009, Sesimbra-Lisbon, 24 June 2009 through 26 June 2009 ; 2009 , Pages 217-222 ; 9781424445950 (ISBN) ; Sedaghat, Y ; Miremadi, G ; Ejlali, A. R ; Sharif University of Technology
2009
Abstract
This paper proposes a low-cost fault-tolerant Carry Look-Ahead (CLA) adder which consumes much less power and area overheads in comparison with other fault-tolerant CLA adders. Analytical and experimental results show that this adder corrects all single-bit and multiple-bit transient faults. The Power-Delay Product (PDP) and area overheads of this technique are decreased at least 82% and 71%, respectively, as compared to adders which use traditional TMR, parity prediction, and duplication techniques. © 2009 IEEE
Application of fuzzy set modeling in infrastructure visual impact assessment
, Article 10th East Asia-Pacific Conference on Structural Engineering and Construction, EASEC 2010, Bangkok, 3 August 2006 through 5 August 2006 ; Volume 2 , 2006 , Pages 263-268 ; Tolouei, R ; Namazi, S ; Sharif University of Technology
2006
Abstract
Infrastructure visual impact assessment based on an opinion survey and fuzzy set modeling was attempted. Photographs reflecting various transportation infrastructure and environment features were displayed to a group of transportation professionals and users. The group was asked to complete a relevant questionnaire regarding the highway infrastructure appearance acceptability of photographs. A set of visual impact descriptive variables was identified and directly measured from the photographs. Information about the descriptive variables, questionnaire responses and fuzzy set theory was used to develop membership functions of visual acceptability. More than two hundred candidate membership...
A high speed and low cost error correction technique for the carry select adder
, Article International Conference on Availability, Reliability and Security, ARES 2009, Fukuoka, Fukuoka Prefecture, 16 March 2009 through 19 March 2009 ; 2009 , Pages 635-640 ; 9780769535647 (ISBN) ; Miremadi, S. G ; Ejlali, A ; Sharif University of Technology
2009
Abstract
In this paper, a high speed and low cost error correction technique is proposed for the Carry Select Adder (CSA) which can correct both transient and permanent errors and is applicable on all partitioning types of the basic CSA circuit. The proposed error correction technique is compatible with all existing error detection techniques which are proposed for the CSA adder. The synthesized results show that applying this novel error correction technique to a CSA with error detection technique results in up to 18.4%, 3.1% and 14.9%, increase in power consumption, delay and area respectively. © 2009 IEEE
Changing Attitude towards Human in the Renaissance
, M.Sc. Thesis Sharif University of Technology ; Golshani, Mehdi (Supervisor)
Abstract
Natural sciences have philosophical and ideological fundamentals. "The attitude towards human", is one of these philosophic or metaphysical fundamentals of science so that scientists and researchers, attentive or not, take it as a basis for their scientific activities. In the other hand, "the science" also affects "The attitude towards human", and different scientific theories caused various attitudes towards human to take shape. "Renaissance" is one of the most important and sophisticated historical periods of the west`s history, and the changes in this period are among the main basics of entering the modern age. In this thesis, first of all some issues about the fundamentals of the science...
Philosophical Approach of Slamic Thinkers Toward Technology Explanation and Critique Ayatollah Khameneie, Ayatollah Motahari and Dr. Nasr Attituude
, Ph.D. Dissertation Sharif University of Technology ; Hosseini, Hassan (Supervisor)
Abstract
Technology is one of the most important aspects of human life at the present time. It can be said that there is no part of human life that is not affected by technology, that is, the most important aspects of human life, namely economic, social and political issues, are independent of technological technology and technology. Technology is not independent of the social systems in which they are formed. In such a situation, one can expect from Islam as a religion claiming human guidance in the most important aspects of life, which can not be ignored by technology and its place in human life, and can provide a way to interact. Human and technology and technology development in the community. In...
EMBB-URLLC Coexistence with a Multi Connectivity Approach
, M.Sc. Thesis Sharif University of Technology ; Hossein Khalaj, Babak (Supervisor) ; Ravanshid, Azad (Co-Supervisor)
Abstract
In addition to improving on current services, future mobile networks will need to support new services types. Two of the envisioned services are enhanced mobile broadband (eMBB) and ultra-reliable low-latency communication. The unprecedented requirements of the new services are out of the reach of current networks, moreover, the diverse characteristics of the new services poses great challenges to the network designers. One of these challenges is designing an efficient resource allocation algorithm that effectively deals with different timescales that the URLLC and eMBB services operate at. A promising enabling technology is multi-connectivity. Multi connectivity is defined as using spatial...
Stimulation of spinal cord according to recorded theta hippocampal rhythm during rat move on treadmill
, Article Biomedizinische Technik ; Volume 68, Issue 4 , 2023 , Pages 351-360 ; 00135585 (ISSN) ; Rahmani, S ; Shanesazzadeh, F ; Ahmadvand, T ; Namazi, M ; Fardmanesh, M ; Kiani, S ; Sharif University of Technology
De Gruyter Open Ltd
2023
Abstract
Objectives: Several studies have revealed that after spinal cord injury (SCI), in acute and sub-acute phase the spinal cord neurons below the injury are alive and could stimulate by use of electrical pulses. Spinal cord electrical stimulation could generate movement for paralyzed limbs and is a rehabilitation strategy for paralyzed patients. An innovative idea for controlling spinal cord electrical stimulation onset time is presented in current study. Methods: In our method, the time of applying electrical pulse on the spinal cord is according to rat behavioral movement and two movements behaviors are recognized only based on rat EEG theta rhythm on the treadmill line. Briefly, 5 rats were...
Mitigating the performance and quality of parallelized compressive sensing reconstruction using image stitching
, Article 29th Great Lakes Symposium on VLSI, GLSVLSI 2019, 9 May 2019 through 11 May 2019 ; 2019 , Pages 219-224 ; 9781450362528 (ISBN) ; Mohammadi Makrani, H ; Tian, Z ; Rafatirad, S ; Akbari, M. H ; Sasan, A ; Homayoun, H ; ACM Special Interest Group on Design Automation (SIGDA) ; Sharif University of Technology
Association for Computing Machinery
2019
Abstract
Orthogonal Matching Pursuit is an iterative greedy algorithm used to find a sparse approximation for high-dimensional signals. The algorithm is most popularly used in Compressive Sensing, which allows for the reconstruction of sparse signals at rates lower than the Shannon-Nyquist frequency, which has traditionally been used in a number of applications such as MRI and computer vision and is increasingly finding its way into Big Data and data center analytics. OMP traditionally suffers from being computationally intensive and time-consuming, this is particularly a problem in the area of Big Data where the demand for computational resources continues to grow. In this paper, the data-level...
SUT-DAM: An integrated software environment for multi-disciplinary geotechnical engineering
, Article Advances in Engineering Software ; Volume 37, Issue 11 , 2006 , Pages 728-753 ; 09659978 (ISSN) ; Gharehbaghi, S. A ; Azami, A. R ; Tabarraie, A. R ; Sharif University of Technology
Elsevier Ltd
2006
Abstract
As computer simulation increasingly supports engineering design, the requirement for a computer software environment providing an integration platform for computational engineering software increases. A key component of an integrated environment is the use of computational engineering to assist and support solutions for complex design. In the present paper, an integrated software environment is demonstrated for multi-disciplinary computational modeling of structural and geotechnical problems. The SUT-DAM is designed in both popularity and functionality with the development of user-friendly pre- and post-processing software. Pre-processing software is used to create the model, generate an...
Contact friction simulation in powder compaction process based on the penalty approach
, Article Materials and Design ; Volume 29, Issue 6 , 2008 , Pages 1199-1211 ; 02613069 (ISSN) ; Khoei, A. R ; Khaloo, A. R ; Sharif University of Technology
Elsevier Ltd
2008
Abstract
In this paper, the influence of powder-tool friction on the mechanical properties of the final product is investigated in pressing metal powders. A computational algorithm is presented for simulation of frictional contact in the compaction process of powder. The large deformation finite element (FE) formulation is characterized by the use of penalty approach in which a plasticity theory of friction is incorporated to simulate sliding resistance at the powder-tool interface. The constitutive relations for friction are derived from a Coulomb friction law. A double-surface cap plasticity model is employed together with the nonlinear contact friction behavior in numerical simulation of powder...
An atomistic–continuum multiscale analysis for heterogeneous nanomaterials and its application in nanoporous gold foams
, Article Applied Mathematical Modelling ; Volume 107 , 2022 , Pages 353-378 ; 0307904X (ISSN) ; Sameti, A. R ; Khoei, A. R ; Sharif University of Technology
Elsevier Inc
2022
Abstract
In this paper, an atomistic–continuum homogenization multiscale method is developed to study the nonlinear behavior of heterogeneous nanomaterials. The atomistic representative volume element (RVE) with vacancy and/or void defects are analyzed by employing the fully atomistic method, in which the nucleation, migration, and elimination of dislocation, as well as the dislocation-vacancy interaction, are captured. The coarse-scale material domain is modeled within the framework of the nonlinear finite element method, and the impression of nanoscale material defects is investigated by upscaling the stress tensor and tangent modulus from the atomistic RVE based on the Hill-Mandel principle. The...
Improved passivity criterion in haptic rendering: influence of coulomb and viscous friction [electronic resource]
, Article Advanced Robotics ; 2014 Volume 28, Issue 10 ; R. Bozorgmehry, R ; Nahvi, A ; Meghdari, A ; Asgari, P ; Sharif University of Technology
Abstract
In this paper, a new criterion for passivity of haptic devices is obtained. This criterion creates a relationship between Coulomb friction coefficient, viscous friction coefficient, sampling rate, and the maximum simulated stiffness. The process of derivation of the passivity criterion is described in detail. This criterion is improved compared with other existing criteria and predicts passivity in haptic rendering more accurately. In particular, for speeds of less than 5 cm/s, the new passivity criterion should replace the previous criteria to avoid unwanted vibrations of stiff virtual walls. Analytical and numerical investigations are presented to validate the new criterion. A specific...
Growth and field emission study of molybdenum oxide nanostars
, Article Journal of Physical Chemistry C ; Volume 113, Issue 44 , 2009 , Pages 19298-19304 ; 19327447 (ISSN) ; Azimirad, R ; Zavarian, A. A ; Zaker Moshfegh, A. R ; Sharif University of Technology
2009
Abstract
The field emission properties of MoO2 nanostars grown on a silicon substrate and their emission performance in various vacuum gaps are reported in this article. A new structure of molybdenum oxides, named a nanostar, is grown by thermal vapor deposition with a length of ̃1 μm, a thickness of ̃50 nm, and its width in the range of 500-700 nm. The morphology, structure, composition, and chemical states of the prepared nanostars were characterized by scanning electron microscopy, high-resolution transmission electron microscopy, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). According to XRD analysis, the grown nanostructures are composed of both crystalline Mo4O11 and...
Design and control of an assistive exoskeleton with passive toe joint
, Article International Journal of Mechatronics and Automation ; Volume 6, Issue 2-3 , 2018 , Pages 83-93 ; 20451059 (ISSN) ; Shariat, A ; Khezrian, R ; Zibafar, A ; Rashidi, A. R ; Rostami, H ; Vossoughi, G. R ; Selk Ghafari, A ; Sharif University of Technology
Inderscience Enterprises Ltd
2018
Abstract
Several exoskeletons with various configurations and degrees-of-freedoms (DOFs) have been introduced in the literature, but not many have addressed the optimal selection of the mechanism's DOFs. In the proposed system a semi-passive toe joint is introduced to achieve several advantages. The performance of the proposed novel passive toe joint is evaluated experimentally. In addition, the semi-passive abduction/adduction DOFs in the hip joint and eversion/inversion DOFs in ankle joint is proposed to facilitate turning while providing more comfort during normal walking. The effect of passive DoFs existence on the user comfortability is studied with the aid of three kinematic indices. In the...
Theoretical investigation of dielectric corona pre-ionization TEA nitrogen laser based on transmission line method
, Article Optics and Laser Technology ; Volume 39, Issue 5 , 2007 , Pages 1014-1019 ; 00303992 (ISSN) ; Fallah, R ; Ganjovi, A. R ; Bahrampour, A ; Sharif University of Technology
2007
Abstract
This paper models the dielectric corona pre-ionization, capacitor transfer type of flat-plane transmission line traveling wave transverse excited atmospheric pressure nitrogen laser by a non-linear lumped RLC electric circuit. The flat-plane transmission line and the pre-ionizer dielectric are modeled by a lumped linear RLC and time-dependent non-linear RC circuit, respectively. The main discharge region is considered as a time-dependent non-linear RLC circuit where its resistance value is also depends on the radiated pre-ionization ultra violet (UV) intensity. The UV radiation is radiated by the resistance due to the surface plasma on the pre-ionizer dielectric. The theoretical predictions...
A study of the reliability of various types of the electric vehicles
, Article 2012 IEEE International Electric Vehicle Conference, IEVC 2012 ; 2012 ; 9781467315623 (ISBN) ; Ghahnavieh, A. R ; Mobarakeh, A. S
2012
Abstract
The reliability Studies are done in order to determine the probability of functioning or availability of different engineering systems. These studies can also provide a basis for comparing different structures of a system and can be used as a tool to improve the system design. Also, reliability is an important consideration in the planning, design and operation of transit system. Since the issue of the reliability of electric vehicles has not been sufficiently and seriously evaluated yet, so in this paper, the reliability of the various types of these kinds of vehicles will be discussed and then the reliability indices of them will be compared with each other and with the conventional cars
A new wideband MIMO channel model for simulating 5-GHz band indoor WLANs
, Article 2006 IEEE 64th Vehicular Technology Conference, VTC-2006 Fall, Montreal, QC, 25 September 2006 through 28 September 2006 ; 2006 , Pages 2298-2303 ; 15502252 (ISSN); 1424400635 (ISBN); 9781424400638 (ISBN) ; Golparvar Roozbahani, M ; Shishegar, A. A ; Enayati, A. R ; Alihemmati, R ; Sharif University of Technology
2006
Abstract
Considerable interest in the indoor applications of wireless local-area networks (WLANs) demands some powerful simulation methods of these systems. Proper modeling of the physical propagation channel is crucial in this context. A novel simulation method for indoor wideband multi-input multi-output (MIMO) channel at the operating frequency band of IEEE 802.11a, HIPERLAN/2, and the emerging IEEE 802.11n standards is presented in this paper which is suitable for performance analysis of MIMO techniques in these systems. The presented model is developed on the basis of a previously proposed channel representation at the same frequency band. Simulation results for MIMO channel capacity are...
Modified carrageenan. 4. Synthesis and swelling behavior of crosslinked kappa C-g-AMPS superabsorbent hydrogel with antisalt and pH-responsiveness properties [electronic resource]
, Article Journal of Applied Polymer Science ; Vol.98, No.1, 255-263, 2005 ; Hosseinzadeh, H ; Mazidi, R
Abstract
To synthesize a novel biopolymer-based superabsorbent hydrogel, 2-acrylamido-2-methylpropanesulfonic acid (AMPS) was grafted onto kappa-carrageenan (KC) backbones. The graft copolymerization reaction was carried out in a homogeneous medium and in the presence of ammonium persulfate (APS) as an initiator, N,N,N',N'-tetramethyl ethylenediamine (TMEDA) as an accelerator, and N,N'-methylene bisacrylamide (MBA) as a crosslinker. A proposed mechanism for KC-g-AMPS formation was suggested and the hydrogel structure was confirmed using FTIR spectroscopy. The affecting variables on swelling capacity, i.e., the initiator, the crosslinker, and the monomer concentration, as well as reaction temperature,...
Effect of TiO2 nanofiber density on organic-inorganic based hybrid solar cells
, Article International Journal of Engineering, Transactions A: Basics ; Vol. 27, issue. 7 , 2014 , p. 1133-1138 ; Kasaeian, A. B ; Nikfarjam, A. R ; Mohammadpour, R ; Sharif University of Technology
2014
Abstract
In this work, a comparative study of hybrid solar cells based on P3HT and TiO2 nanofibers was accomplished. Electrospinning, a low cost production method for large area nanofibrous films, was employed to fabricate the organic-inorganic hybrid solar cells based on poly (3-hexylthiophene) and TiO2 nanofibers. The performance of the hybrid solar cells was analyzed for four density levels of TiO2 nanofibers which resulted in the average power conversion efficiency of about 0.0134% under AM 1.5 simulated illuminations (100 mWcm-2). It is found that the higher densities of TiO2 lead to more interface area and generating exciton, so the power conversion efficiency will be increased till the active...
Forming limit diagrams by including the M–K model in finite element simulation considering the effect of bending
, Article Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications ; Volume 232, Issue 8 , 2018 , Pages 625-636 ; 14644207 (ISSN) ; Hashemi, R ; Ghazanfari, A ; Naghdabadi, R ; Assempour, A ; Sharif University of Technology
SAGE Publications Ltd
2018
Abstract
Forming limit diagram is often used as a criterion to predict necking initiation in sheet metal forming processes. In this study, the forming limit diagram was obtained through the inclusion of the Marciniak–Kaczynski model in the Nakazima out-of-plane test finite element model and also a flat model. The effect of bending on the forming limit diagram was investigated numerically and experimentally. Data required for this simulation were determined through a simple tension test in three directions. After comparing the results of the flat and Nakazima finite element models with the experimental results, the forming limit diagram computed by the Nakazima finite element model was more convenient...