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Design a Content-Based Color Image Retrieval Using Attention Driven Saliency Map
, M.Sc. Thesis Sharif University of Technology ; Fatemizadeh, Emadeddin (Supervisor)
Abstract
Content Based Image Retrieval (CBIR) is in fact an image search engine which Operates on image Context . in this thesis (project) the aim was to use the Visual attention of humans in detecting the objects in image. in this ability first a salient image of the most important things in the image would be created And after an initial separation , for the final recognition the other features (details) in the image will be used It’s a while that the use of Visual attention models and saliency maps in designing the interfaces between humans and machines has been considered widely. This fact in the design of CBIR systems has not a good background (satisfying history). In this thesis I have...
Command Increasing in SSVEP based BCI Using Color
, M.Sc. Thesis Sharif University of Technology ; Shamsollahi, Mohamad Bagher (Supervisor)
Abstract
Nowadays, a brain-computer interface (BCI) systems is considered as one of the necessary needs for individuals who are capable of doing their daily tasks. Despite of recent technological developments, such systems are not widely utilized. Spelling vocabularies and controlling wheelchairs are the most useful examples of using BCI. Todays, there has been a wide range of methods for establishing the connection between mind and computer. One of these methods is brain -Computer Interface Applications based on Steady State Visual Evoked Potentials (SSVEP). Although, these applications has a capability of fast responds and data transitions, only a few tasks can be given to the computer. In this...
4D Hand Gesture Recognition on RGB-D Videos
, M.Sc. Thesis Sharif University of Technology ; Kasaei, Shohreh (Supervisor)
Abstract
Hand gesture recognition is one of the most applicable and hot research topics in computer vision community. The recent advances in imaging devices, like Microsoft Kinect, have received a great deal of attention from researchers to reconsider problems such as gesture recognition from depth information. Hand gesture recognition refers to the classification of dynamic hand movements in action videos. Generally, hand gesture recognition includes three main steps: hand detection, feature extraction and classification. The first step plays an important role in hand gesture recognition. The most challenging part of hand gesture recognition is the second step which is the process of extracting high...
Stream-wise and cross-flow vortex induced vibrations of single tapered circular cylinders: An experimental study
, Article Applied Ocean Research ; Volume 42 , 2013 , Pages 124-135 ; 01411187 (ISSN) ; Tamimi, V ; Saeed Seif, M ; Sharif University of Technology
2013
Abstract
Tapered circular cylinders are employed in a variety of ocean engineering applications. While being geometrically simple, this configuration creates a complex flow pattern in the near wake of the structure. Most previous experimental studies on tapered circular cylinders were dealing with stationary cylinders to explore the wake flow field and vortex shedding patterns past the cylinder. Few studies paid attentions to the vortex induced vibration of the tapered cylinders. This paper reports some results from in-water towing-tank experiments on the vortex-excited vibrations of tapered circular cylinders in a uniform flow. Cylinders with different mean diameters (28 and 78 mm), mass ratios (6.1...
Patchwise joint sparse tracking with occlusion detection
, Article IEEE Transactions on Image Processing ; Vol. 23, Issue. 10 , 2014 , Pages. 4496-4510 ; ISSN: 10577149 ; Rabiee, H. R ; Soltani-Farani, A ; Khajenezhad, A ; Sharif University of Technology
Abstract
This paper presents a robust tracking approach to handle challenges such as occlusion and appearance change. Here, the target is partitioned into a number of patches. Then, the appearance of each patch is modeled using a dictionary composed of corresponding target patches in previous frames. In each frame, the target is found among a set of candidates generated by a particle filter, via a likelihood measure that is shown to be proportional to the sum of patch-reconstruction errors of each candidate. Since the target's appearance often changes slowly in a video sequence, it is assumed that the target in the current frame and the best candidates of a small number of previous frames, belong to...
Applications and challenges of wearable visual lifeloggers
, Article Computer ; Volume 50, Issue 3 , 2017 , Pages 60-69 ; 00189162 (ISSN) ; Hosseini, M ; Kanhere, S. S ; Sowmya, A ; Rabiee, H. R ; Sharif University of Technology
IEEE Computer Society
2017
Abstract
Advances in the manufacturing of miniaturized low-power embedded systems are paving the way for ultra-lightweight wearable cameras that can visually log the minute details of people's daily lives. This survey highlights the possible applications of wearable cameras, from industrial to personal, and outlines the main challenges in realizing their full potential. © 2017 IEEE
Visualization of pool boiling heat transfer of magnetic nanofluid
, Article Heat Transfer - Asian Research ; Volume 48, Issue 7 , 2019 , Pages 2700-2713 ; 10992871 (ISSN) ; Ebrahimi Dehshali, M ; Bijarchi, M. A ; Shafii, M. B ; Moosavi, A ; Sharif University of Technology
John Wiley and Sons Inc
2019
Abstract
To increase heat transfer, ferrofluids have been utilized to study the effective parameters of pool boiling. Changes and possible enhancement of pool boiling heat transfer of magnetic fluids is a function of magnetic field and concentration of nanoparticles. To the best knowledge of the authors, no systematic experiments have been conducted to visualize the phenomena during the boiling of ferrofluids with different concentrations. In this study an experimental investigation has been conducted, by designing and fabricating a novel hele-shaw vessel with glass sides, to explore via visualizations some details in the pool boiling of ferrofluids. Boiling patterns of ferrofluids at various...
Computational inverse design for cascaded systems of metasurface optics: comment
, Article Optics Express ; Volume 30, Issue 20 , 2022 , Pages 36966-37005 ; 10944087 (ISSN) ; Khavasi, A ; Sharif University of Technology
Optica Publishing Group (formerly OSA)
2022
Abstract
In a recently published article by Backer [Opt. Express 27(21), 30308 (2019).], a computational inverse design method is developed for designing optical systems composed of multiple metasurfaces. The forward propagation model used in this method was a discretized version of the angular spectrum propagator described by Goodman [Introduction to Fourier Optics, 1996]. However, slight modifications are necessary to increase the accuracy of this inverse design method. This comment examines the accuracy of the results obtained by the above-mentioned method by a full-wave electromagnetic solver and explains the reason of their difference. Thereafter, slight modifications to the method proposed by...
Sensory representation of visual stimuli in the coupling of low-frequency phase to spike times
, Article Brain Structure and Function ; Volume 227, Issue 5 , 2022 , Pages 1641-1654 ; 18632653 (ISSN) ; Jahed, M ; Dezfouli, M. P ; Daliri, M. R ; Sharif University of Technology
Springer Science and Business Media Deutschland GmbH
2022
Abstract
Neural synchronization has been engaged in several brain mechanisms. Previous studies have shown that the interaction between the time of spiking activity and phase of local field potentials (LFPs) plays a key role in many cognitive functions. However, the potential role of this spike–LFP phase coupling (SPC) in neural coding is not fully understood. Here, we sought to investigate the role of this SPC for encoding the sensory properties of visual stimuli. To this end, we measured SPC strength in the preferred and anti-preferred motion directions of stimulus presented inside the receptive field of middle temporal (MT) neurons. We found a selective response in terms of SPC strength for...
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...
Asphaltene deposition during CO 2 injection and pressure depletion: A visual study
, Article Energy and Fuels ; Volume 26, Issue 2 , December , 2012 , Pages 1412-1419 ; 08870624 (ISSN) ; Ayatollahi, S ; Alamdari, A ; Zolghadr, A ; Dashti, H ; Kord, S ; Sharif University of Technology
Abstract
Carbon dioxide miscible flooding has become a popular method for Enhanced Oil Recovery (EOR) because it not only efficiently enhances oil recovery but also considerably reduces green house gas emissions. However, it can significantly cause asphaltene deposition, which leads to serious production problems such as wettability alteration, plugging of the reservoir formation, blocking the transportation pipelines, etc. It is crucial to investigate the effects of different factors on asphaltene deposition. A novel experimental setup was prepared to employ a high-pressure visual cell for investigation of asphaltene deposition on a model rock under typical reservoir conditions. The evolution of...
Introducing a two dimensional measure for watermarking capacity in images
, Article Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), 25 June 2008 through 27 June 2008, Povoa de Varzim ; Volume 5112 LNCS , 2008 , Pages 213-220 ; 03029743 (ISSN) ; 9783540698111 (ISBN) ; Jamzad, M ; Sharif University of Technology
2008
Abstract
One of the most important parameters in evaluating a watermarking algorithm is its capacity. Of course capacity has a paradoxical relation with two other important parameters: image quality and robustness. Generally, watermarking capacity is expressed by bit per pixel (bpp) unit measure. This measure does not show what the side effects would be on image quality and capacity. Therefore, we proposed a two dimensional measure named capacity curve which shows the effects of capacity on visual quality. In this measure we can find the amount of degradation by a numerical value for each modification in pixels. Our experimental results are compatible with previous works in this field. © 2008...
Introducing a new method for estimation image complexity according to calculate watermark capacity
, Article 2008 4th International Conference on Intelligent Information Hiding and Multiedia Signal Processing, IIH-MSP 2008, Harbin, 15 August 2008 through 17 August 2008 ; 2008 , Pages 981-984 ; 9780769532783 (ISBN) ; Jamzad, M ; Sharif University of Technology
2008
Abstract
One of the most important parameters in evaluating a watermarking algorithm is its capacity. In fact, capacity has a paradoxical relation with other two important parameters: image quality and robustness. Some works have been done on watermarking capacity and a few on image complexities. Most works on watermarking capacity is based on information theory and the capacity values which are calculated based on these methods are very tolerate. In this paper we propose a new method for calculating image complexity based on Region Of Interest (ROI) concept. After that we analyze three complexity measures named: Image compositional complexity (ICC), Quad tree and ROI method, with three different...
Efficient generation of self-avoiding, semiflexible rotational isomeric chain ensembles in bulk, in confined geometries, and on surfaces
, Article Computer Physics Communications ; Volume 270 , 2022 ; 00104655 (ISSN) ; Galata, A. A ; Sadeghi, M ; Kröger, A ; Kröger, M ; Sharif University of Technology
Elsevier B.V
2022
Abstract
We provide an efficient ready-to-run code gensaw that generates single or large ensembles of self-avoiding, flexible, semiflexible, rotationally isometric or helical chains in the bulk or subject to arbitrary confinement and tethering conditions, where we allow for arbitrary intramolecular bending and dihedral energy functions. The resulting configuration files are provided in various common formats and can be immediately used to do molecular simulations or statistical analysis. We work out analytic expressions for the mean squared end-to-end distance and gyration radius of the semiflexible, helical and rotational isomeric state models with a finite number of bonds and arbitrary interaction...
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...
INFELT STEP: An integrated and interoperable platform for collaborative CAD/CAPP/CAM/CNC machining systems based on STEP standard
, Article International Journal of Computer Integrated Manufacturing ; Volume 23, Issue 12 , 2010 , Pages 1095-1117 ; 0951192X (ISSN) ; Houshmand, M ; Sharif University of Technology
Abstract
Integrated product development is comprised of CAD, process planning and CNC code generation based on an integrated data structure. To make various CAD/CAM software solutions with different internal product data structures interoperable, it is necessary to realise reliable and robust information exchange capability in a manufacturing environment. To enable interoperability amongst integrated product development processes, management of collaboration of diverse CAD/CAM software packages is of outmost importance. In this article, the fundamental requirements for achieving interoperability and collaboration management in an integrated, enterprise-wide, product development process environment...
A novel algorithm for impulse noise classification in digital images
, Article International Review on Computers and Software ; Volume 4, Issue 6 , 2009 , Pages 627-632 ; 18286003 (ISSN) ; Tork Ladani, B ; Zamanifar, K ; Nematbakhsh, N ; Sharif University of Technology
2009
Abstract
Noise reduction is a major concern in digital image processing systems, which have been investigated by several techniques. One kind of important noises in images is known as Salt & Pepper, which may have different causes. In this paper a new approach for eliminating this type of noise is presented. The approach is different from all previous works in this field, and is based on classification. More precisely, it tries to classify pixels of an image to one of two categories: noisy or not noisy. Afterward, it employs a median filter for pixels which have been classified as noisy, and remains others unchanged; hence, edges and other fine details are kept. Experimental results show this...
Dispersion around a circular cylinder in surface wave motion
, Article Scientia Iranica ; Vol. 21, issue. 3 , 2014 , p. 548-556 ; 10263098 ; Jamali, M ; Sharif University of Technology
Abstract
In this paper, we examine fluid flow and associated dispersion around a circular cylinder under progressive surface wave motion. The flow field and vortex shedding patterns were studied using flow visualization and Particle Image Velocimetry (PIV). Several patterns of vortex shedding were identified around a single cylinder. The vortex shedding patterns under progressive wave motion are similar to those observed in planar oscillatory flow, except in the way the vortices form and in the orientation they take. The observed vortex patterns in progressive wave motion are more unstable than those in planar oscillatory flow. Using particle tracking and the Lagrangian dispersion method, the...
An implementation of a CBIR system based on SVM learning scheme
, Article Journal of Medical Engineering and Technology ; Volume 37, Issue 1 , 2013 , Pages 43-47 ; 03091902 (ISSN) ; Fatemizadeh, E ; Badie, K ; Sharif University of Technology
2013
Abstract
Content-based image retrieval (CBIR) has been one of the most active areas of research. The retrieval principle of CBIR systems is based on visual features such as colour, texture and shape or the semantic meaning of the images. A CBIR system can be used to locate medical images in large databases. This paper presents a CBIR system for retrieving digital human brain magnetic resonance images (MRI) based on textural features and the support vector machine (SVM) learning method. This system can retrieve similar images from the database in two groups: normal and tumoural. This research uses the knowledge of the CBIR approach to the application of medical decision support and discrimination...
An interactive cbir system based on anfis learning scheme for human brain magnetic resonance images retrieval
, Article Biomedical Engineering - Applications, Basis and Communications ; Volume 24, Issue 1 , 2012 , Pages 27-36 ; 10162372 (ISSN) ; Fatemizadeh, E ; Badie, K ; Sharif University of Technology
2012
Abstract
Content-based image retrieval (CBIR) has turned into an important and active potential research field with the advance of multimedia and imaging technology. It makes use of image features, such as color, texture and shape, to index images with minimal human intervention. A CBIR system can be used to locate medical images in large databases. In this paper we propose a CBIR system which describes the methodology for retrieving digital human brain magnetic resonance images (MRI) based on textural features and the Adaptive neuro-fuzzy inference system (ANFIS) learning to retrieve similar images from database in two categories: normal and tumoral. A fuzzy classifier has been used, because of the...