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An investigation on the torsional sensitivity and resonant frequency of an AFM with sidewall and top-surface probes
, Article ASME 2010 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference, IDETC/CIE2010, Montreal, QC, 15 August 2010 through 18 August 2010 ; Volume 4 , 2010 , Pages 589-599 ; 9780791844120 (ISBN) ; Ahmadian, M. T ; Haghighi, P ; Haghighi, A ; Sharif University of Technology
2010
Abstract
The resonant frequencies and torsional sensitivities of an atomic force microscope (AFM) with assembled cantilever probe (ACP) are studied. This ACP comprises a horizontal cantilever, a vertical extension and two tips located at the free ends of the cantilever and the extension which makes the AFM capable of simultaneous topography at top-surface and sidewalls of microstructures especially microgears which consequently leads to a time-saving swift scanning process. In this work, the effects of the sample surface contact stiffness and the geometrical parameters such as the ratio of the vertical extension length to the horizontal cantilever length and the distance of the vertical extension...
An investigation on the flexural sensitivity and resonant frequency of an AFM with sidewall and top-surface probes
, Article ASME International Mechanical Engineering Congress and Exposition, Proceedings (IMECE), 12 November 2010 through 18 November 2010, Vancouver, BC ; Volume 10 , 2010 , Pages 419-427 ; 9780791844472 (ISBN) ; Ahmadian, M. T ; Haghighi, P ; Haghighi, A ; Sharif University of Technology
2010
Abstract
The resonant frequencies and flexural sensitivities of an atomic force microscope (AFM) assembled cantilever probe which comprises a horizontal cantilever, a vertical extension and two tips located at the free ends of the cantilever and the extension are studied. This probe makes the AFM capable of simultaneous topography at top-surface and sidewalls of microstructures especially microgears which leads to a time-saving swift scanning process. In this work, the effects of the sample surface contact stiffness and the geometrical parameters such as the ratio of the vertical extension length to the horizontal cantilever length and the distance of the vertical extension from clamped end of the...
Sensitivity and resonant frequency of an AFM with sidewall and top-surface probes for both flexural and torsional modes
, Article International Journal of Mechanical Sciences ; Volume 52, Issue 10 , October , 2010 , Pages 1357-1365 ; 00207403 (ISSN) ; Ahmadian, M. T ; Haghighi, P ; Haghighi, A ; Sharif University of Technology
2010
Abstract
The resonant frequencies and flexural sensitivities of an atomic force microscope (AFM) with assembled cantilever probe (ACP) are studied. This ACP comprises a horizontal cantilever, a vertical extension and two tips located at the free ends of the cantilever and the extension, which makes the AFM capable of simultaneous topography at top surface and sidewalls of microstructures especially microgears, which consequently leads to a time-saving swift scanning process. In this work, the effects of the sample surface contact stiffness and the geometrical parameters such as the ratio of the vertical extension length to the horizontal cantilever length and the distance of the vertical extension...
Fabrication of a novel 3D scaffold for cartilage tissue repair: In-vitro and in-vivo study
, Article Materials Science and Engineering C ; Volume 128 , 2021 ; 09284931 (ISSN) ; Shamloo, A ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
Self-repairing is not an advanced ability of articular cartilage. Tissue engineering has provided a novel way for reconstructing cartilage using natural polymers because of their biocompatibility and bio-functionality. The purpose of cartilage tissue engineering is to design a scaffold with proper pore structure and similar biological and mechanical properties to the native tissue. In this study, porous scaffolds prepared from gelatin, chitosan and silk fibroin were blended with varying ratios. Between the blends of chitosan (C), gelatin (G) and silk fibroin (S), the scaffold with the weight per volume ratio of 2:2:3 (w/v) showed the most favorable and higher certain properties than the...
Behran Mehr Peyma's Activities Analysis
, M.Sc. Thesis Sharif University of Technology ; Miremadi, Alireza (Supervisor)
Abstract
Behran Mehr Peyma (BMP) is an elevator equipment producer and trader in Iran which was established in 2004. At first they are producing some regular parts of elevator and then during these years they are trying to improve their work and expand their business till they have the 15% market share in elevator market in Tehran.In this thesis I am trying to use the SWOT and PETS methods to show the exact situation of BMP comparing to the whole market considering the competitors.During this reduction in the market I suggest to BMP to change some policies and use some of its strength to attract some new customers, changing their brand name and find a relation to contribute in some tenders and...
Needle Steering in Soft Tissue
, M.Sc. Thesis Sharif University of Technology ; Jahed, Mehran (Supervisor)
Abstract
Medical needle interventions are a common technique for accessing tissue structures.In these procedures, needles are used, for example, to extract biopsy samples, brachytherapy, and to insert drugs. In TRUS guided prostate brachytherapy application, Physicians used ulterasound imaging to steer the needle and insert radioactive seeds into cancerous tumors to irradiate surrounding tissue over several months. Prostate rotation, deformation, and unavailability of imaging data during part of the insertion path result in misplaced seeds. To overcome these problems, in this research, we modeled the prostate, its membrane and the surrounding fatty tissue as linearly elastic homogenous material, and...
Experimental Investigation on Debonding between FRP sheets and Structures
, M.Sc. Thesis Sharif University of Technology ; Toufigh, Vahab (Supervisor)
Abstract
This study has investigated the effects of different environmental conditions on the bond at the interface between two fiber reinforced polymer (FRP) layers. A total of 945 single lap splice coupons with three bond length were made using wet lay-up technic. There were used three unidirectional fabrics and one type of epoxy resin. A Uniaxial tensile test was performed on samples after 2, 4, 12, 20, 28, 36 and 48 weeks of exposure. Also series of test were conducted in order to determine the minimum lap splice length of single splice FRP samples. The experimental results indicated reduction of bond strength in glass specimens that was 17 % after 48 weeks of exposure while for same amount of...
A Hardware-Software Partitioner for Deep Learning Algorithms
, M.Sc. Thesis Sharif University of Technology ; Hessabi, Shahin (Supervisor)
Abstract
Deep learning, as a subdivision of machine learning, attempts to model high-level concepts by using a deep graph, consisting of several layers of linear and nonlinear transformations. Implementing these algorithms on hardware is a big challenge.¬This project offers a system in which various hardware methodologies can be used to implement deep learning algorithms side by side. The overall structure of the system consists of high-level programming interfaces for implementation and expression of machine learning algorithms by the user, which will be available as libraries in a high-level programming language such as Python, Ruby, and Julia. These interfaces allow the user to evaluate their...
Analysis of Temporal Stability and Transferability of Trip Distribution Models Considering Urban Development Patterns: The Case of Shiraz
, M.Sc. Thesis Sharif University of Technology ; Shafahi, Yousef (Supervisor)
Abstract
Trip distribution is the second step of the four-step travel demand modeling. Like other travel demand models, the most important objective of trip distribution models generation is forecasting the travel data of a year in the future. On the one hand, extensive changes in cities’ urban structures and people’s travel behavior during the years brings up the essential question of how temporally stable and transferable trip distribution models are? This question becomes even more important when the more complex structure of trip distribution models compared to models such as trip generation is considered. On the other hand, it is logical to assume that the consideration of the effects of urban...
Design and Manufacture of an Engineered Scaffold in Order to Repair Tissue Exposed to Mechanical Force, for Tissue Engineering Application
, M.Sc. Thesis Sharif University of Technology ; Shamloo, Amir (Supervisor)
Abstract
Articular cartilage has limited repair capability following traumatic injuries and current methods of treatment remain inefficient. Reconstructing cartilage provides a new way for cartilage repair and natural polymers are often used as scaffold because of their biocompatibility and biofunctionality. The goal of cartilage tissue engineering is to design a scaffold with proper pore structure and similar mechanical properties to the native tissue. In this study Porous scaffolds prepared from silk fibroin, chitosan and gelatin blends with varying ratio of silk fibroin and gelatin by freeze drying method were characterized for physicochemical, mechanical and biological properties. Among the...
Biomechanical Effects of Intervertebral Disc Nucleotomy Surgery on Adjacent Joints Using a Coupled Musculoskeletal Finite Element Model
, M.Sc. Thesis Sharif University of Technology ; Arjmand, Navid (Supervisor)
Abstract
According to studies, low back pain is one of the most common and costly musculoskeletal disorders. Herniation of intervertebral discs exerts pressure on the nerves, causing pain. To alleviate this, physicians perform a procedure called nucleotomy, which removes the disc's nucleus pulposus to reduce pressure, retract the disc, and relieve pain. Accurate estimation of spinal forces during activities is essential for injury prevention, activity correction, and improved surgical techniques. Although laboratory studies on humans or cadavers are valid, they are often invasive and limited to simple scenarios, necessitating precise computational models for comprehensive biomechanical analysis....
Real-time topography and hamaker constant estimation in atomic force microscopy based on adaptive fading extended kalman filter
, Article International Journal of Control, Automation and Systems ; Volume 19, Issue 7 , 2021 , Pages 2455-2467 ; 15986446 (ISSN) ; Nejat Pishkenari, H ; Sharif University of Technology
Institute of Control, Robotics and Systems
2021
Abstract
In this study, a novel technique based on adaptive fading extended Kalman filter for atomic force microscopy is proposed to directly estimate the topography of a sample surface without needing any control system. While in conventional imaging techniques, the scanning speed or the bandwidth is limited due to a relatively large settling time, the method proposed in this research is able to address this issue and estimate the topography throughout transient oscillation of the microcantilever. With this aim, an estimation process using an adaptive fading extended Kalman filter (augmented with forgetting factor) as the system observer is designed and coupled with the system dynamics to obtain...
Towards a calculus for nondeterministic schemas in Z
, Article International Journal of Software Engineering and Knowledge Engineering ; Volume 22, Issue 6 , September , 2012 , Pages 839-865 ; 02181940 (ISSN) ; Mirian Hosseinabadi, S. H ; Sharif University of Technology
World Scientific
2012
Abstract
In our previous work, we presented a Z-based formalism, called NZ, by which one can explicitly specify bounded, unbounded, erratic, angelic, demonic, loose, strict, singular, and plural nondeterminism. The NZ notation is mainly based on a new notion of operation schemas, called multi-schema. Since the operations of the Z schema calculus do not work on multi-schemas anymore, in this paper we augment NZ with a new set of schema calculus operations that can be applied on multi-schemas as well as ordinary operation schemas. To demonstrate the usability of the resulting formalism, we show how this formalism can assist to model game-like situations and concurrent systems as two well-known classes...
A safe stopping protocol to enable reliable reconfiguration for component-based distributed systems
, Article 6th International Conference on Fundamentals of Software Engineering, FSEN 2015, 22 April 2015 through 24 April 2015 ; Volume 9392 , November , 2015 , Pages 100-109 ; 03029743 (ISSN) ; 9783319246437 (ISBN) ; Heydarnoori, A ; Haghighi, H ; Sharif University of Technology
Springer Verlag
2015
Abstract
Despite the need for change, highly available software systems cannot be stopped to perform changes because disruption in their services may consequent irrecoverable losses. Current work on runtime evolution are either too disruptive, e.g., "blackouts" in unnecessary components in the quiescence criterion approach or presume restrictive assumptions such as the "black-box design" in the tranquility approach. In this paper, an architecture-based approach, called SAFER, is proposed which provides a better timeliness by relaxing any precondition required to start reconfiguration. We demonstrate the validity of the SAFER through model checking and a realization of the approach on a component...
A refinement approach for developing probabilistic programs
, Article 2009 14th International CSI Computer Conference, CSICC 2009, 20 October 2009 through 21 October 2009 ; 2009 , Pages 140-145 ; 9781424442621 (ISBN) ; Mirian Hosseinabadi, S. H ; Sharif University of Technology
2009
Abstract
In this paper, we introduce a refinement approach to develop probabilistic programs formally. To achieve this goal, we first present a way to specify probabilistic programs in a Z-based notation. We then use an existing method of translating Z into a refinement calculus to transform our Z-style specifications of probabilistic programs into specification statements of the refinement calculus. We finally add new laws to the refinement calculus helping us to refine the resulting specification statements into probabilistic choice constructs of a probabilistic imperative language. In this way, we will provide a completely formal way for developing probabilistic programs. ©2009 IEEE
A practical approach to networked control design for robust H∞ performance in the presence of uncertainties in both communication and system
, Article Applied Mathematics and Computation ; Volume 381 , 2020 ; Tavassoli, B ; Farhadi, A ; Sharif University of Technology
Elsevier Inc
2020
Abstract
This work presents results on the development of robust H∞ control strategy for Networked Control Systems (NCSs) by involving uncertainties in both communication and controlled plant subsystems. The network-induced delays in both communication links (to and from the controller) are assumed to behave as Markov chains. An analytical approach is presented to calculate the transition probabilities of the Markovian network-induced delays. By employing the augmentation method, the resultant system is converted into a delay-free uncertain singular Markovian jump system with bounded transition probabilities. New conditions are established to assure that the uncertain NCS satisfies an H∞ performance...
Nondeterminism in constructive Z
, Article Fundamenta Informaticae ; Volume 88, Issue 1-2 , 2008 , Pages 109-134 ; 01692968 (ISSN) ; Mirian Hosseinabadi, S. H ; Sharif University of Technology
2008
Abstract
The abstraction inherent in most specifications and the need to specify nondeterministic programs are two well-known sources of nondeterminism in formal specifications. In this paper, we present a Z-based formalism by which one can specify bounded, unbounded, erratic, angelic, demonic, loose, strict, singular, and plural nondeterminism. To interpret our specifications, we use a constructive set theory, called CZ set theory, instead of the classical set theory Z. We have chosen CZ since it allows us to investigate the notion of nondeterminism from the formal program development point of view. In this way, we formally construct functional programs from Z specifications and then probe the...
An approach to nondeterminism in translation of CZ set theory into martin-Löf 's theory of types
, Article Electronic Notes in Theoretical Computer Science ; Volume 159, Issue 1 , 2006 , Pages 117-137 ; 15710661 (ISSN) ; Mirian Hosseinabadi, S. H ; Sharif University of Technology
2006
Abstract
Due to the high level of abstraction involved in formal specification of software systems, nondeterminism comes as an inevitable part of formal specifications. Therefore, support for nondeterminism should be provisioned in developing programs from their formal specifications. In this paper, an existing translation of CZ set theory into Martin-Löf's theory of types is extended to consider nondeterministic specifications in CZ language. © 2006 Elsevier B.V. All rights reserved
OS-level Data Tiering to Improve Performance of RAID Arrays
, M.Sc. Thesis Sharif University of Technology ; Asadi, Hossein (Supervisor)
Abstract
Storage is well-known as the performance bottleneck in I/O intensive programs such as online transaction processing applications; thus designing a cost-effective high performance disk subsystem is a major concern in enterprise applications. Data tiering is an efficient way to optimize cost, performance, and reliability in storage servers. With the promising advantages of Solid State Drives (SSDs) over Hard Disk Drives (HDDs) such as lower power consumption and higher performance , traditional data tiering techniques should be revisited in order to use SSDs in a more efficient way. This thesis presents a data tiering technique at the Operating System (OS) level to enhance system performance...
On Quantification of Seismic Performance Factors for Integral Abutment Bridges
, M.Sc. Thesis Sharif University of Technology ; Maleki, Shervin (Supervisor)
Abstract
Integral abutment bridges (IABs) are bridges in which the deck is cast monolithically with abutment backwalls. These bridges are also jointless through deck length, due to which they act as a frame in their longitudinal direction. These differences with common seat-type bridge construction, have made IABs more economical to build and maintain and superior in seismic performance. As such, in various countries, this method of construction have been prescribed whenever possible. As an instance, integral construction is mandatory for bridges up to 60 meters in total length in England. IABs have become more of a geotechnical problem rather than simple structural problem of conventional bridges in...