Photoactive and self-cleaning TiO 2-SiO 2 thin films on 316L stainless steel

, Article Thin Solid Films ; Volume 520, Issue 20 , 2012 , Pages 6355-6360 ; 00406090 (ISSN) Boroujeny, B. S ; Afshar, A ; Dolati, A ; Sharif University of Technology

2012

Abstract

In this study, TiO 2-SiO 2 nanocomposite films with different amounts of SiO 2 were prepared by sol-gel process and were coated onto stainless steel 316L. The effect of addition of various amount of SiO 2 in the precursor solution on the photocatalysis, photo-generated hydrophilicity and self-cleaning property of TiO 2 thin films was investigated by X-ray diffraction, Fourier transform infrared spectroscopy, water contact angle measurements and UV spectroscopy. In the tested ranges of SiO 2 content and sintering temperature, the highest photocatalytic activity and self-cleaning property were observed in the 15 mol% SiO 2 sample sintered at 750 °C. Addition of less than 30 mol% SiO 2 had a...

Photoactive TiO2–SiO2 Thin Films on 316L Stainless Steel for Self-Cleaning Application, Tribological Properties and Corrosion Protection

, Ph.D. Dissertation Sharif University of Technology Shayegh Boroujeny, Behrooz (Author) ; Afshar, Abdollah (Supervisor) ; Dolati, Abolghasem (Supervisor)

Abstract

In this study, TiO2-SiO2 nanocomposite films with different amount of SiO2 were prepared by sol-gel process and were coated onto stainless steel 316L. The effect of addition of various amounts of SiO2 in the precursor solution on the structure, morphology, photocatalysis, photo-generated hydrophilicity, self-cleaning property and mechanical properties of TiO2 thin films and corrosion behavior of AISI 316L stainless steel substrate, was investigated. For this purpose, X-ray diffraction, Fourier transform infrared spectroscopy, water contact angle measurements, UV spectroscopy, field-emission scanning electron microscopy, atomic force microscopy, depth-sensing indentation technique supporting...

A learning based method for topology control in wireless sensor networks

, Article 5th International Conference on Autonomic and Autonomous Systems, ICAS 2009, Valencia, 20 April 2009 through 25 April 2009 ; 2009 , Pages 51-55 ; 9780769535845 (ISBN) Khasteh, S. H ; Shouraki, S. B ; Sharif University of Technology

2009

Abstract

Topology Control (TC) is one of the most important techniques used in wireless ad hoc and sensor networks to reduce energy consumption and radio interference, The goal of this technique is to control the topology of the graph representing the communication links between network nodes with the purpose of maintaining some global graph property (e.g., connectivity), while reducing energy consumption and/or interference that are strictly related to the nodes' transmitting range. In this paper we present a new distributed learning based method to choose nodes transmitting range, in this method we run a range adjustment mechanism periodically to choose a near optimal transmitting range, we don't...

Interface electromagnetic waves between Kronig-Penney photonic crystals

, Article Aplications of Photonic Technology, Quebec City, 1 June 2002 through 6 June 2002 ; Volume 4833 , 2002 , Pages 535-541 ; 0277786X (ISSN) Mehrany, K ; Momeni, B ; Khorasani, S ; Rashidian, B ; Sharif University of Technology

2002

Abstract

The electromagnetic interface states formed in a heterostructure composed of two semi-infinite Kronig-Penny photonic crystals were studied. Modified transfer matrices were used for the study to show strong similarity between solid-state physics and electromagnetics. The calculations were limited to TE polarization and the numerical examples for both surface and interface states were given

Optimization of dynamic mobile robot path planning based on evolutionary methods

, Article 2015 AI and Robotics, IRANOPEN 2015 - 5th Conference on Artificial Intelligence and Robotics, 12 April 2015 ; April , 2015 , Page(s): 1 - 7 ; 9781479987337 (ISBN) Fetanat, M ; Haghzad, S ; Shouraki, S. B ; Sharif University of Technology

Institute of Electrical and Electronics Engineers Inc 2015

Abstract

This paper presents evolutionary methods for optimization in dynamic mobile robot path planning. In dynamic mobile path planning, the goal is to find an optimal feasible path from starting point to target point with various obstacles, as well as smoothness and safety in the proposed path. Pattern search (PS) algorithm, Genetic Algorithm (GA) and Particle Swarm Optimization (PSO) are used to find an optimal path for mobile robots to reach to target point with obstacle avoidance. For showing the success of the proposed method, first they are applied to two different paths with a dynamic environment in obstacles. The first results show that the PSO algorithms are converged and minimizethe...

Bipolar transistor based on graphane

, Article Journal of Physics: Conference Series, 5 July 2010 through 10 July 2010 ; Volume 248 , 2010 ; 17426588 (ISSN) Gharekhanlou, B ; Tousaki, S. B ; Khorasani, S ; Sharif University of Technology

2010

Abstract

Graphane is a semiconductor with an energy gap, obtained from hydrogenation of the two-dimensional grapheme sheet. Together with the two-dimensional geometry, unique transport features of graphene, and possibility of doping graphane, p and n regions can be defined so that p-n junctions become feasible with small reverse currents. Our recent analysis has shown that an ideal I-V characteristic for this type of junctions may be expected. Here, we predict the behavior of bipolar juncrion transistors based on graphane. Profiles of carriers and intrinsic parameters of the graphane transistor are calculated and discussed

Evolution of multiple states machines for recognition of online cursive handwriting

, Article 2006 World Automation Congress, WAC'06, Budapest, 24 June 2006 through 26 June 2006 ; 2006 ; 1889335339 (ISBN); 9781889335339 (ISBN) Halavati, R ; Shouraki, S. B ; Hassanpour, S ; Sharif University of Technology

IEEE Computer Society 2006

Abstract

Recognition of cursive handwritings such as Persian script is a hard task as there is no fixed segmentation and simultaneous segmentation and recognition is required. This paper presents a novel comparison method for such tasks which is based on a Multiple States Machine to perform robust elastic comparison of small segments with high speed through generation and maintenance of a set of concurrent possible hypotheses, The approach is implemented on Persian (Farsi) language using a typical feature set and a specific tailored genetic algorithm and the recognition and computation time is compared with dynamic programming comparison approach. Copyright - World Automation Congress (WAC) 2006

Use of active learning method to develop an intelligent stop and go cruise control

, Article Proceedings of the IASTED International Conference on Intelligent Systems and Control, Salzburg, 25 June 2003 through 27 June 2003 ; 2003 , Pages 87-90 ; 0889863555 (ISBN) Shahdi, S. A ; Shouraki, S. B ; IASTED ; Sharif University of Technology

2003

Abstract

This paper is concerned with the design and simulation of an intelligent stop and go cruise control system in an automated vehicle. In this paper Active learning method is used to extract driver's behavior and to derive control rules for cruise control system. First, there is a brief introduction to ALM (Active Learning Method) and its specifications. Then a one-line space for driving is assumed and its parameters are extracted. By using IDS, the processing engine of ALM, effective parameters in controller are derived. A simulation program is written to produce learning samples and also to evaluate controller's parameters. To apply controller's output, appropriate acceleration of the...

An optimal hardware implementation for active learning method based on memristor crossbar structures

, Article IEEE Systems Journal ; Vol. 8, issue. 4 , 2014 , pp. 1190-1199 ; ISSN: 19328184 Esmaili Paeen Afrakoti, I ; Shouraki, S. B ; Haghighat, B ; Sharif University of Technology

2014

Abstract

This paper presents a new inference algorithm for active learning method (ALM). ALM is a pattern-based algorithm for soft computing, which uses the ink drop spread (IDS) algorithm as its main engine for feature extraction. In this paper, a fuzzy number is extracted from each IDS plane rather than from the narrow path and the spread, as in previous approaches. This leads to a significant reduction in the hardware required to implement the inference part of the algorithm and real-time computation of the implemented hardware. A modified version of the memristor crossbar structure is used to solve the problem of varying shapes of the ink drops, as reported in previous studies. In order to...

Modified shuffled-frog-leaping algorithm in company with neural networks for harmonic distortion minimisation in real-time control applications of programmed pulse-width modulation inverters

, Article IET Power Electronics ; Volume 4, Issue 8 , 2011 , Pages 943-950 ; 17554535 (ISSN) Alimardani, A ; Mazaheri, B ; Abdi, B ; Hosseinian, S. H ; Sharif University of Technology

2011

Abstract

Harmonic pollution minimisation in voltage-source programmed pulse-width modulation (PPWM) inverters is defined as a time-limited optimisation problem in real-time applications with variable DC sources. In order to obtain minimum total harmonic distortion (THD) as the objective function, shuffled-frog-leaping algorithm (SFLA) is modified and employed to calculate the switching angles and compared with non-linear programming as a traditional optimisation method. In addition, particle swarm optimisation and three of its modified versions as popular evolutionary optimisation algorithms are employed to ensure the capability of the proposed optimisation method. Moreover, modified sinusoidal PWM...

ECG denoising using modulus maxima of wavelet transform

, Article Proceedings of the 31st Annual International Conference of the IEEE Engineering in Medicine and Biology Society: Engineering the Future of Biomedicine, EMBC 2009 ; 2009 , Pages 416-419 ; 1557170X (ISSN) Ayat, M ; Shamsollahi, M. B ; Mozaffari, B ; Kharabian, S ; Sharif University of Technology

2009

Abstract

ECG denoising has always been an important issue in medical engineering. The purposes of denoising are reducing noise level and improving signal to noise ratio (SNR) without distorting the signal. This paper proposes a method for removing white Gaussian noise from ECG signals. The concepts of singularity and local maxima of the wavelet transform modulus were used for analyzing singularity and reconstructing the ECG signal. Adaptive thresholding was used to remove white Gaussian noise modulus maximum of wavelet transform and then reconstruct the signal

ECG denoising using modulus maxima of wavelet transform

, Article Proceedings of the 31st Annual International Conference of the IEEE Engineering in Medicine and Biology Society: Engineering the Future of Biomedicine, EMBC 2009, 2 September 2009 through 6 September 2009, Minneapolis, MN ; 2009 , Pages 416-419 ; 9781424432967 (ISBN) Ayat, M ; Shamsollahi, M. B ; Mozaffari, B ; Kharabian, S ; Sharif University of Technology

2009

Abstract

ECG denoising has always been an important issue in medical engineering. The purposes of denoising are reducing noise level and improving signal to noise ratio (SNR) without distorting the signal. This paper proposes a method for removing white Gaussian noise from ECG signals. The concepts of singularity and local maxima of the wavelet transform modulus were used for analyzing singularity and reconstructing the ECG signal. Adaptive thresholding was used to remove white Gaussian noise modulus maximum of wavelet transform and then reconstruct the signal. ©2009 IEEE

A portable culture chamber for studying the effects of hydrostatic pressure on cellular monolayers

, Article Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science ; Volume 233, Issue 3 , 2019 , Pages 807-816 ; 09544062 (ISSN) Kiyoumarsioskouei, A ; Saidi, M. S ; Mosadegh, B ; Firoozabadi, B ; Sharif University of Technology

SAGE Publications Ltd 2019

Abstract

Hydrostatic pressure is one of the most fundamental and common mechanical stimuli in the body, playing a critical role in the homeostasis of all organ systems. Kidney function is affected by high blood pressure, namely hypertension, by the increased pressure acting on the glomerular capillary walls. This general effect of hypertension is diagnosed as a chronic disease, but underlying mechanistic causes are still not well understood. This paper reports a portable and adaptive device for studying the effects of hydrostatic pressure on a monolayer of cells. The fabricated device fits within a conventional incubation system and microscope. The effects of various pressures and durations were...

Flexibility analysis of a supply chain using design structure matrix

, Article Gain Competitive Advantage by Managing Complexity - Proceedings of the 14th International Dependency and Structure Modelling Conference, DSM 2012, 13 September 2012 through 14 September 2012 ; September , 2012 , Pages 79-88 ; 9783446433540 (ISBN) Yousefi, Z ; Malaek, S. M. B ; Emamipour, S ; Sharif University of Technology

Institution of Engineering Designers 2012

Abstract

Now days supply chain systems operate in an operational environment with high uncertainty. Customer globalization, increase of natural and manmade disasters, outsourcing in far distances have increased uncertainty. Flexibility as a capability can help systems included supply chains respond to uncertainty and deliver value to their users. auto supply chain is the one that has suffered from these disasters. This paper encapsulates operational environment uncertainty through scenario development, then scores the scenarios based on some proxies. Design structure matrix is proposed to show the typical auto supply chain relationships before scenario occurring consequences and after that. in the...

Rate adaptation and power allocation for time-correlated MISO Rayleigh fading channel with delay-limited HARQ

, Article IEEE International Conference on Communications, 10 June 2012 through 15 June 2012 ; 2012 , Pages 3915-3919 ; 15503607 (ISSN) ; 9781457720512 (E-ISBN) Rastegar, S. H ; Vakilinia, S ; Khalaj, B. H ; Sharif University of Technology

2012

Abstract

In this paper, we consider the problem of optimum rate adaptation and power allocation to maximize the delay-limited throughput (DLT) in a time-correlated 2×1 MISO Rayleigh fading channel with Hybrid ARQ in Chase-Combining mode (HARQ-CC). To this aim, we have first formulated the DLT equation based on the outage probability for 2×1 MISO-HARQ channel. We show that exact analytical calculation of the outage probability is not tractable. Therefore, we approximate the outage probability using a log-normal approximation approach. Based on such approximation, optimal rate and power allocations are derived. Finally, using Monte-Carlo simulation, we show that the approximation method provides...

Numerical and 1-D modeling of systemic circulation along with cerebral vasculature

, Article 2012 19th Iranian Conference of Biomedical Engineering, ICBME 2012 ; 2012 , Pages 17-21 ; 9781467331302 (ISBN) Salehi, S. S ; Firoozabadi, B ; Saidi, M. S ; Sharif University of Technology

2012

Abstract

The brain is one of the vital organs in the body. The main cerebral distribution center of blood flow in the brain is the circle of Willis (CoW). In more than 50% of healthy brains and in more than 80% of dysfunctional ones, at least one artery of the circle of Willis is absent or underdeveloped. These variations reduce the collateral flow availability and increase the risk of stroke and transient ischemic attack in patients with atherosclerosis. Thus it is essential to simulate the circle of Willis and investigate the effects of stenosis. In this work the systemic arteries along with the circle of Willis are simulated using the finite volume method and one-dimensional equations of...

Fundamental frequency estimation using modified higher order moments and multiple windows

, Article Proceedings of the Annual Conference of the International Speech Communication Association, INTERSPEECH ; 2011 , Pages 1965-1968 ; 19909772 (ISSN) Pawi, A ; Vaseghi, S ; Milner, B ; Ghorshi, S ; Sharif Univesity of Technology

2011

Abstract

This paper proposes a set of higher-order modified moments for estimation of the fundamental frequency of speech and explores the impact of the speech window length on pitch estimation error. The pitch extraction methods are evaluated in a range of noise types and SNRs. For calculation of errors, pitch reference values are calculated from manually-corrected estimates of the periods obtained from laryngograph signals. The results obtained for the 3 rd and 4 th order modified moment compare well with methods based on correlation and magnitude difference criteria and the YIN method; with improved pitch accuracy and less occurrence of large errors

Numerical and 1-D modeling of pulmonary circulation along with lumped parameter modeling of the heart

, Article 2013 20th Iranian Conference on Biomedical Engineering, ICBME 2013 ; December , 2013 , Pages 93-97 Salehi, S. S ; Firoozabadi, B ; Saidi, M. S ; Sharif University of Technology

IEEE Computer Society 2013

Abstract

A one dimensional model of the pulmonary arterial network along with systemic circulation was introduced to quantify the human pulmonary artery hemodynamics. A lumped parameter model of the right ventricle was used as the inlet boundary condition. A time varying elastance related the volume and pressure of the right ventricle was imposed in the model. By using a four element Windkessel model, blood flow rate throughout the right ventricle was in hand. An asymmetric structured tree was chosen as the outlet boundary conditions. Simulation was based on solving one-dimensional equations of conservation of mass and momentum by using finite volume method. Blood flow rate, pressure and velocity...

Formulation of differential transfer matrix method in cylindrical geometry

, Article Proceedings of SPIE - The International Society for Optical Engineering, 25 January 2010 through 28 January 2010 ; Volume 7597 , January , 2010 ; 0277786X (ISSN) ; 9780819479938 (ISBN) Jiani, M ; Khorasani, S ; Rashidian, B ; Mohammadi, S ; Sharif University of Technology

2010

Abstract

Transfer and scattering matrix methods are widely in use for description of the propagation of waves in multilayered media. When the profile of refractive index is continuous, however, a modified formulation of transfer matrices does exist, which provides a complete analytical solution of the wave phenomena in such structures. Previously reported variations of the so-called Differential Transfer Matrix Method (DTMM) had been limited to Cartesian geometry where layered media form one-dimensional structures and plane waves are used as basis functions. In this work, we extend the formalism to cylindrical geometry with radial symmetry, in which Bessel functions need to be employed as basis...

Fast estimation of space-robots inertia parameters: A modular mathematical formulation

, Article Acta Astronautica ; Volume 127 , 2016 , Pages 283-295 ; 00945765 (ISSN) Nabavi Chashmi, S. Y ; Malaek, S. M. B ; Sharif University of Technology

Elsevier Ltd 2016

Abstract

This work aims to propose a new technique that considerably helps enhance time and precision needed to identify "Inertia Parameters (IPs)" of a typical Autonomous Space-Robot (ASR). Operations might include, capturing an unknown Target Space-Object (TSO), "active space-debris removal" or "automated in-orbit assemblies". In these operations generating precise successive commands are essential to the success of the mission. We show how a generalized, repeatable estimation-process could play an effective role to manage the operation. With the help of the well-known Force-Based approach, a new "modular formulation" has been developed to simultaneously identify IPs of an ASR while it captures a...