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kohani--fereshteh
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Using Base Isolators in Bridges to Reduce the Dynamic Forces of Piers and Abutments
, M.Sc. Thesis Sharif University of Technology ; Jahanshahi, Mohsen (Supervisor)
Abstract
In recent years, the application of base isolation as a seismic design strategy for reducing the effects of earthquake ground motion has become an advantageous method and much effort has been devoted to base isolation research and there has been a growing acceptance of this approach. In this research, the effect of using base isolators in reducing the dynamic forces of piers and abutments of bridges is studied. More specifically double-span bridges are the target of this research. After modeling a regular bridge in a typical analysis program, it is excited by different earthquake accelerograms and then the effect of using base isolators in dissipating the earthquake energy is investigated
Identifying the tool-tissue force in robotic laparoscopic surgery using neuro-evolutionary fuzzy systems and a synchronous self-learning hyper level supervisor
, Article Applied Soft Computing Journal ; Vol. 14, issue. PART A , January , 2014 , pp. 12-30 ; Behzadipour, S ; Kohani, M ; Sharif University of Technology
2014
Abstract
In this paper, two different hybrid intelligent systems are applied to develop practical soft identifiers for modeling the tool-tissue force as well as the resulted maximum local stress in laparoscopic surgery. To conduct the system identification process, a 2D model of an in vivo porcine liver was built for different probing tasks. Based on the simulation, three different geometric features, i.e. maximum deformation angle, maximum deformation depth and width of displacement constraint of the reconstructed shape of the deformed body are extracted. Thereafter, two different fuzzy inference paradigms are proposed for the identification task. The first identifier is an adaptive co-evolutionary...
Tool-tissue force estimation in laparoscopic surgery using geometric features
, Article Studies in Health Technology and Informatics ; Volume 184 , 2013 , Pages 225-229 ; 09269630 (ISSN) ; Behzadipour, S ; Farahmand, F ; Sharif University of Technology
IOS Press
2013
Abstract
This paper introduces three geometric features, from deformed shape of a soft tissue, which demonstrate good correlation with probing force and maximum local stress. Using FEM simulation, 2D and 3D model of an in vivo porcine liver was built for different probing tasks. Maximum deformation angle, maximum deformation depth and width of displacement constraint of the reconstructed shape of the deformed body were calculated. Two neural networks were trained from these features and the calculated interaction forces. The features are shown to have high potential to provide force estimation either for haptic devices or to assess the damage to the tissue in large deformations of up to 40%
Application of Software-Defined Networking In Network Management
, M.Sc. Thesis Sharif University of Technology ; Pakravan, Mohammad Reza (Supervisor)
Abstract
Software-Defined Networking is a new approach in networking which provides a great opportunity to improve network management. Network policy decisions and reachability policies are one of the main concerns of the network administrators. These policies are traditionally configured in different network devices. The configurations are manually implemented using ACLs in routers, firewalls, VLANs, etc. Network engineers configure every single device on the network with its vendor-specific low level language. As a result, access control policies of the network lie in the configuration files of the network devices or even only in the minds of the network engineers. Moreover, access control policies...
Investigation of hydrogen sensing properties and aging effects of Schottky like Pd/porous Si
, Article Journal of Sensors and Actuators B: Chemical ; Volume 146, Issue 1 , 8 April , 2010 , PP. 53–60 ; Iraji Zad, A. (Azam) ; Rahimi, F. (Fereshteh) ; Sharif University of Technology
2010
Abstract
We prepared porous silicon samples coated by continuous palladium layer in electroless process. Scanning electron microscopy (SEM) showed cauliflower-shape Pd clusters on the surface. I–V curves of Schottky like Pd/porous Si samples were measured in air and in hydrogen. These measurements showed a metal–interface–semiconductor configuration rather than an ideal Schottky diode. Variations of the electrical current in the presence of diluted hydrogen at room temperature revealed that the samples can sense hydrogen in a wide range of concentration (100–40,000 ppm) without any saturation behavior. Hydrogen sensing properties of these samples were investigated at room temperature for a duration...
Real-Time Vision-Based Approach for Estimating Contact Forces on Soft Tissues, with Applications to Laparoscopic surgery
,
M.Sc. Thesis
Sharif University of Technology
;
Farahmand, Farzam
(Supervisor)
;
Behzadipour, Saeed
(Co-Advisor)
Abstract
Lack of force feedback during minimally invasive procedures is one of the downsides of such interventions and might result to excessive damage to surrounding tissues. The goal of the present research is to introduce a vision-based approach to estimate contact forces on soft tissues. In this approach, a model was developed in which, image of deformation of a sample soft tissue, under the jaws of laparoscopic gripper, is the input and the output is the gripper force.
In this method, using finite element simulation, a database from different deformations of a rectangular soft tissue was generated. Accordingly, from the geometric position of nodes of the upper surface of the...
In this method, using finite element simulation, a database from different deformations of a rectangular soft tissue was generated. Accordingly, from the geometric position of nodes of the upper surface of the...
Effects of Mica and Feldspar as partial cement replacement on the rheological, mechanical and thermal durability of self-compacting mortars
, Article Construction and Building Materials ; Volume 263 , December , 2020 ; Fard Samimi, M ; Mohammadi, F ; Talebitaher, P ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
In this experimental study, the impacts of replacing cement by Mica and Feldspar on rheological, mechanical and thermal durability of self-compacting mortars (SCMs) are investigated. The cement was partially replaced by Mica and Feldspar at the substitution rates of 10%, 20% and 30%. In general, 14 mix designs of SCMs were considered in two series with w/b ratios of 0.4 and 0.3. For assessment of rheological properties, mini-cone slump flow test and mini V-funnel tests were performed. The compressive strengths after 3, 7, 28 and 90 days of curing, and the 28-day flexural strength were obtained. All mixes were subjected to water absorption and sorptivity tests. For investigating the thermal...