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BRST quantization of noncommutative gauge theories
, Article Physical Review D ; Volume 68, Issue 10 , 2003 ; 05562821 (ISSN) ; Sharif University of Technology
American Physical Society
2003
Abstract
In this paper, the Becchi-Rouet-Stora-Tyutin (BRST) symmetry transformation is presented for the noncommutative U(N) gauge theory. The nilpotency of the charge associated with this symmetry is then proved. As a consequence of the spacelike noncommutativity parameter, the Hubert space of physical states is determined by the cohomology space of the BRST operator as in the commutative case. Further, the unitarity of the S-matrix elements projected onto the subspace of the physical states is deduced. © 2003 The American Physical Society
BRST quantization of noncommutative gauge theories
, Article Physical Review D - Particles, Fields, Gravitation and Cosmology ; Volume 67, Issue 10 , 2003 ; 15507998 (ISSN) ; Sharif University of Technology
2003
Abstract
In this paper, the Becchi-Rouet-Stora-Tyutin (BRST) symmetry transformation is presented for the noncommutative [Formula Presented] gauge theory. The nilpotency of the charge associated with this symmetry is then proved. As a consequence of the spacelike noncommutativity parameter, the Hilbert space of physical states is determined by the cohomology space of the BRST operator as in the commutative case. Further, the unitarity of the S-matrix elements projected onto the subspace of the physical states is deduced. © 2003 The American Physical Society
Unsteady Analysis of a Slinger Combustion Chamber by the Chemical Reactor Network Model
, M.Sc. Thesis Sharif University of Technology ; Farshchi, Mohammad (Supervisor)
Abstract
Up to early seventies, Gas turbine combustor design was very time consuming and costly process including trial and errors through test rigs. Over the time analytical-experimental relationships take place as one of the key rules in the design processes. With the increasing power of computer calculations, computational fluid dynamics find its way in the procedure. Obtaining a deeper understanding of flow conditions and geometry inside the chamber, a great reduction in production time and cost of revisions to rigs and samples were achieved. Finding a precise prediction of polluting elements like NOx (less than 10 ppm) after many run hours and enormous computing resources, CFD methods must...
Workspace measurement of the surgeon's upper limb during an arthroscopy and three laparoscopy operations using inertial sensor systems
, Article 2013 E-Health and Bioengineering Conference, EHB 2013 ; 2013 ; 9781479923731 (ISBN) ; Farahmand, F ; Sharif University of Technology
2013
Abstract
The aim of this study was to determine the workspace of surgeon's body for designing more efficient surgical robots in the operation rooms. Five wearable inertial sensors were placed near the wrist and elbow joints and also on the thorax of surgeons to track the orientation of upper limb. Assuming that the lengths of five segments of an upper limb were known, measurements of the inertial sensors were used to determine the position of the wrist and elbow joints via an established kinematic model. subsequently, to assess the workspace of surgeon upper body, raw data were collected in the arthroscopy and laparoscopy operations. Experimental results demonstrated that the workspaces of surgeon's...
Modeling and Simulation of Alcoholic Fermentation of Sugarcane Blackstrap Molasses
, M.Sc. Thesis Sharif University of Technology ; Yaghmaee, Sohila (Supervisor)
Abstract
Fed-batch fermentation is a valuable and cost-effective method for bio-based production of various products such as ethanol, which has various applications in various industries.In recent years, bioethanol production has been given special attention in many countries. For this reason, the mathematical modeling of production of these products is very important for their optimal and cost-effective production. Given the transient and dynamic nature of fermentation and its specific complexity, mathematical modeling of fed-batch bioreactors is difficult and complicated. In this research, an unstructured model was used to predict the production of ethanol from blackstrap sugar cane molasses based...
Effect of capillary tube's shape on capillary rising regime for viscos fluids
, Article 2017 International Conference on Nanomaterials and Biomaterials, ICNB 2017, 11 December 2017 through 13 December 2017 ; Volume 350, Issue 1 , 2018 ; 17578981 (ISSN) ; Moosavi, A ; Sharif University of Technology
Institute of Physics Publishing
2018
Abstract
When properties of the displacing fluid are considered, the rising profile of the penetrating fluid in a capillary tube deviates from its classical Lucas-Washburn profile. Also, shape of capillary tube can affect the rising profile in different aspects. In this article, effect of capillary tube's shape on the vertical capillary motion in presence of gravity is investigated by considering the properties of the displacing fluid. According to the fact that the differential equation of the capillary rising for a non-simple wall type is very difficult to solve analytically, a finite element simulation model is used for this study. After validation of the simulation model with an experiment that...
Detection of change to SSVEPs using analysis of phase space topological : a novel approach
, Article Neurophysiology ; Volume 51, Issue 3 , 2019 , Pages 180-190 ; 00902977 (ISSN) ; Maghooli, K ; Pisheh, N. F ; Mohammadi, M ; Soroush, P. Z ; Tahvilian, P ; Sharif University of Technology
Springer New York LLC
2019
Abstract
A novel method based on EEG nonlinear analysis and analysis of steady-state visual evoked potentials (SSVEPs) has been processed. The EEG phase space is reconstructed, and some new geometrical features are extracted. Statistical analysis is carried out based on ANOVA, and most significant features are selected and then fed into a multi-class support vector machine (MSVM). Both offline and online phases are considered to fully address SSVEP detection. In the offline mode, the whole design evaluation, feature selection, and classifier training are performed. In the online scenario, the proposed method is evaluated and the detection rate is reported for both phases. Subject-dependent and...
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
How to synchronize and register an optical-inertial tracking system
, Article Applied Mechanics and Materials ; Volume 332 , 2013 , Pages 130-136 ; 16609336 (ISSN) ; 9783037857335 (ISBN) ; Akbar, M ; Farahmand, F ; Sharif University of Technology
2013
Abstract
Multi-sensor tracking is widely used for augmentation of tracking accuracy using data fusion. A basic requirement for such applications is the real time temporal synchronization and spatial registration of two sensory data. In this study a new method for time and space coordination of two tracking sensor measurements has been presented. For spatial registration we used a body coordinate system and then applied the effect of the level arm. The time synchronization was done based on least mean square (LMS) error method. This method was implemented to synchronize the position and orientation of an object using Inertial (1IMU) and Optical (Optotrak) tracking systems. The results of synchronized...
Design and implementation of an improved real-time tracking system for navigation surgery by fusion of optical and inertial tracking methods
, Article Applied Mechanics and Materials ; Volume 186 , 2012 , Pages 273-279 ; 16609336 (ISSN) ; 9783037854440 (ISBN) ; Farahmand, F ; Salarieh, H ; Sharif University of Technology
2012
Abstract
The fusion of the optical and inertial tracking systems seems an attractive solution to solve the shadowing problem of the optical tracking systems, and remove the time integration troubles of the inertial sensors. We developed a fusion algorithm for this purpose, based on the Kalman filter, and examined its efficacy to improve the position and orientation data, obtained by each individual system. Experimental results indicated that the proposed fusion algorithm could effectively estimate the 2 seconds missing data of the optical tracker
A non-user-based BCI application for robot control
, Article 2018 IEEE EMBS Conference on Biomedical Engineering and Sciences, IECBES 2018, 3 December 2018 through 6 December 2018 ; 2019 , Pages 36-41 ; 9781538624715 (ISBN) ; Shamsollahi, M. B ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2019
Abstract
Steady State Visual Evoked Potential (SSVEP) based Brain Computer Interfaces (BCI) can be great assistance for people suffering from physical disabilities due to their high accuracy, high speed, an acceptable number of possible targets, etc. Many researchers have managed to design such systems. Most of these BCIs utilize methods for frequency detection which cause the system to need a training phase for each new user, making the system a user-based one. That is why our goal was to design a BCI that not only has accuracy and speed comparable to similar systems, but also does not need any training phase and thus can be used by new users right away. Our final design got a mean accuracy of...
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...
Investigation on Seismic Performance of Eccentrically Braced Frames with Vertical Post-tensioned Cables
, M.Sc. Thesis Sharif University of Technology ; Kazemi, Mohammad Taghi (Supervisor)
Abstract
Although the moment frame can show deformable behavior against seismic loads, but its flexibility and low stiffness, especially in tall structures, cause the governance criterion to be designed. The use of eccentrically braced frames was able to solve the displacement problem to some extent, because it has the characteristics of both flexural frame systems and conccentric bracing. Different methods have been proposed to eliminate residual displacements in this type of system, one of which is the use of post tensioned cables. The aim of this study was to investigate the seismic behavior of a steel structure with a eccentrically braced frame system with post tension cable.The cables are anchor...
Induction of fuzzy classification systems using evolutionary ACO-Based algorithms
, Article 1st Asia International Conference on Modelling and Simulation - Asia Modelling Symposium 2007, AMS 2007, 27 March 2007 through 30 March 2007 ; 2007 , Pages 346-351 ; 0769528457 (ISBN); 9780769528458 (ISBN) ; Habibi, J ; Soroush, E ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2007
Abstract
In this paper we have proposed an evolutionary algorithm to induct fuzzy classification rules. The algorithm uses an ant colony optimization based local searcher to improve the quality of final fuzzy classification system. The proposed algorithm is performed on Intrusion Detection as a high-dimensional classification problem. Results show that the implemented evolutionary ACO-Based algorithm is capable of producing a reliable fuzzy rule based classifier for intrusion detection. © 2007 IEEE
Effects of COVID-19-related psychological distress and anxiety on quality of sleep and life in healthcare workers in Iran and three European countries
, Article Frontiers in Public Health ; Volume 10 , 2022 ; 22962565 (ISSN) ; Tahvilian, P ; Koohestani, S ; Maghooli, K ; Jafarnia Dabanloo, N ; Sarhangi Kadijani, M ; Jahantigh, S ; Zangeneh Soroush, M ; Saliani, A ; Sharif University of Technology
Frontiers Media S.A
2022
Abstract
Introduction: The COVID-19 pandemic has considerably affected human beings most of whom are healthcare workers (HCWs) combating the disease in the front line. Methods: This cross-sectional study aims to explore the effects of stress and anxiety caused by COVID-19 on the quality of sleep and life in HCWs, including physicians, nurses, and other healthcare staff. In this global study, we asked 1,210 HCWs (620 and 590 volunteers from Iran and European countries, including Germany, the Netherlands, and Italy, respectively), who age 21–70, to participate in the test. Several measures of COVID-related stress, anxiety, sleep, and life quality, including the 12-item General Health Questionnaire...
Predicting fracture of solder joints with different constraint factors
, Article Fatigue and Fracture of Engineering Materials and Structures ; Volume 42, Issue 2 , 2019 , Pages 425-438 ; 8756758X (ISSN) ; Mirmehdi, S ; Farrahi, G ; Soroush, F ; Sharif University of Technology
Blackwell Publishing Ltd
2019
Abstract
Double cantilever beam (DCB) specimens of 2.5-mm-long SAC305 solder joints were prepared with thickness of copper adherends varying from 8 to 21 mm each. The specimens were tested under mode I loading conditions (ie, pure opening mode with no shear component of loading) with a strain rate of 0.03 second−1. The measured fracture load was used to calculate the critical strain energy release rate for crack initiation, Jci, in each case. Fracture behaviour showed a significant dependence on the adherend thickness; the Jci and plastic deformation of the solder at crack initiation decreased significantly with increase in adherend thickness. This behaviour was attributed to changes in stress...
Investigation of Sintering Behavior of BaTiO3 Nanoparticles Synthesized Via Hydrothermal Method
, M.Sc. Thesis Sharif University of Technology ; Nemati, Ali (Supervisor) ; Simchi, Abdolreza (Supervisor)
Abstract
In the present work, Barium Titanate nanoparticles were synthesized by a facile hydrothermal method at 180oC for 4 hours and their sintering behavior was studied. The characterization tests illustrated that the obtained powder was BaTiO3 single phase with excess Ti content from stoichiometric composition. The average particle size of about 50 nm and a narrow particle size distribution was noticed. SEM investigations showed that the samples sintered at temperatures less than 1250oC had plate-like grains. This behavior resulted from twin plates existed in the grains and facetted grain boundaries. At the temperatures more than 1250oC, the grains became polygonal due to the formation of trace...
A prototype system to measure the trunk angle in sagital plane
, Article Proceedings of the 8th IASTED International Conference on Biomedical Engineering, Biomed 2011, 16 February 2011 through 18 February 2011, Innsbruck ; 2011 , Pages 300-304 ; 9780889868663 (ISBN) ; Ramezanzadeh, M ; Narimani, R ; Soroush, A ; Sharif University of Technology
2011
Abstract
The most prevalent musculoskeletal condition and one of the most disabilities are caused by low back pain. In the low back pain, a large variety of evaluation tools is presented to assess the results of the treatment; therefore, it is important to measure the trunk angle in order to determine the progress during patient's treatment. In this project, we developed a low cost prototype system for flexion-extension movement to measure the angle of the trunk in sagital plane. The system consists of clothing that is stretchable; a Rubbery Ruler sensor (RRs) attached on clothing, data acquisition system. Inertial Magnetic Unit (IMU) sensor installed on spine is used to calibrate the orientation for...