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Enhancing Weakly Supervised Semantic Segmentation through Patch-Based Refinement
, M.Sc. Thesis Sharif University of Technology ; Kasaei, Shohreh (Supervisor)
Abstract
Semantic segmentation, a pivotal topic in computer vision, finds extensive applications across various domains. Leveraging deep networks to tackle this challenge necessitates a large dataset with pixel-level annotations, incurring significant time and cost for preparation. Weakly supervised semantic segmentation utilizes less expensive labels, such as image-level annotations, thereby circumventing the need for costly pixel-level annotations. Consequently, weakly supervised learning has garnered considerable attention. In recent years, vision transformers have achieved significant results compared to convolutional neural networks advancing the state of the art. However, employing vision...
Synthesis and Characterization of Vanadium (IV)-SNO & ONO Tridentate Schiff-Base Complexes and Their Applications in Sulfide and Alcohol Oxidation in Ionic Liquid Media
, M.Sc. Thesis Sharif University of Technology ; Bagherzadeh, Mojtaba (Supervisor)
Abstract
In recent years, application of transition metal biphasic catalytic systems for different reactions is an area of intense research activity. Among these reactions, oxidation of sulfides to sulfoxides and sulfones due to their importance as an intermediate in synthesis of organic compounds is a center of interest. Also, the catalytic conversion of alcohols to the corresponding aldehydes or ketones is a fundamental transformation in both laboratory and industrial synthetic chemistry. From environmental perspectives, the development of new catalytic oxidation systems with molecular oxygen as green oxidant is particularly attractive. In recent years, ionic liquids have been extensively studied...
Agent-based Programming and it's Application Using GOAL
,
M.Sc. Thesis
Sharif University of Technology
;
Ramezanian, Rasoul
(Supervisor)
Abstract
With the significant advances in software engineering and developing complicated systems, it’s important to investigate the interaction between systems. Agentoriented software engineering is a new paradigm for developing distributed intelligent systems. Agent technology currently plays an important role in complex software development. The underlying paradigm offers a large repertoire of original concepts, architectures, interaction protocols, and methodologies for the analysis and the specification of complex systems built as Multi-Agent Systems (MAS). Several efforts, originating from academia, industry, and several standardisation consortium, have been made in order to provide new tools,...
Auto-selection of space-time Interest Points for Action Recognition
Application in Fisherposes Method
,
M.Sc. Thesis
Sharif University of Technology
;
Mohammadzadeh, Narges Hoda
(Supervisor)
Abstract
In this project, a novel action recognition method, named Fisherposes, is proposed, which is improved by several space-time (spatio-temporal) methods afterwards. The proposed method utilizes skeleton data obtained from Kinect sensor. First, pre-processing is performed in which the scales of bodies are canceled and the skeletons become aligned in order to make the method robust to location, orientation, and scale of people. In Fisherposes method, every action is defined as a sequence of body poses. Using the training samples for the poses, a Fisher subspace is created which we name it Fisherposes. Moreover, a novel distance measuring function, named regularized Mahalanobis distance, is...
Numerical evaluation of the ultimate load of concrete funicular shells of circular plan
, Article Proceedings of the Institution of Civil Engineers: Structures and Buildings ; Volume 174, Issue 1 , 2021 , Pages 5-11 ; 09650911 (ISSN) ; Mofid, M ; Sharif University of Technology
ICE Publishing
2021
Abstract
A special type of shell structure - a concrete shallow funicular shell of circular plan - is considered in this paper. Funicular shells carry their dead weight only by in-plane compression forces. Numerical analysis of funicular shells was performed using the non-linear finite-element method, considering both geometric and material non-linearities. A circular-plan concrete funicular shell unit was also constructed and its ultimate central concentrated load is determined. The ultimate load of the shell unit predicted by the numerical model was very close to the experimentally determined ultimate load, thus confirming the validity of the numerical model. The numerical results revealed the...
Linear-Differential Cryptanalysis of Word-Reduced Variants of Cubehash
, M.Sc. Thesis Sharif University of Technology ; Khazaei, Shahram (Supervisor)
Abstract
In this thesis, first we will have a brief review on hash functions and related concepts.Then, we will descibe the hash function, Cubehash, which is one of the competitors in the competition held by NIST for selecting SHA-3 standard. Next, we will describe an attack based on linearization of differential paths in hash functions and apply this attack on Cubehash. At the end, we will discuss the results of this attack on Cubehash
Temporal Analysis of Functional Brain Connectivity Using EEG Signals
, M.Sc. Thesis Sharif University of Technology ; Mohammadzadeh, Narges Hoda (Supervisor)
Abstract
Human has different emotions such as happiness, sadness, anger, etc. Recognizing these emotions plays an important role in human-machine interface. Emotion recognition can be divided into approaches, physiological and non-physiological signals. Non-physiological signals include facial expressions, body gesture, and voice, and physiological signals include electroencephalograph (EEG), electrocardiograph (ECG), and functional magnetic resonance imaging (fMRI). EEG signal has been absorbed a lot of attention in emotion recognition because recording of EEG signal is easy and it is non-invasive. Analysis of connectivity and interaction between different areas of the brain can provide useful...
Thermodynamic Analysis of the Temporal Changes in Salt Concentration in Saline Lakes (the case of Urmia lake)
, M.Sc. Thesis Sharif University of Technology ; Tajrishi, Masoud (Supervisor)
Abstract
Urmia Lake is a strong electrolyte containing various salts, with a thermodynamic identity. Changes in the temperature and volume of lake water cause a change in the concentration of ions in this brine as well as the composition and precipitation of salts in the lake. As a result of these changes, the thermodynamic properties of brine are also changed. The purpose of this study was to investigate the effect of mixing the rivers entering the lake and calculate and analyze the changes in the quality and hydrogeochemical characteristics of Urmia Lake and the amount of precipitation and dissolution of the main minerals in Urmia Lake during the period of 2007-2013 per month. For this purpose,...
Determination and Quantification of Social, Economic, and Climatic Factors in the Uncertainty of Urmia Lake Restoration Program (ULRP)
, M.Sc. Thesis Sharif University of Technology ; Tajrishi, Massoud (Supervisor)
Abstract
Lake Urmia in northwest Iran is an important water body at the national and international level and plays a significant role in the natural, social, and economic aspects of life in the region. Unfortunately, as a result of natural and anthropologic factors, the lake has suffered a severe water decline in recent decades and was even on the verge of complete drying. Being aware of the catastrophic consequences of lake Urmia's desiccation, a megaproject called Urmia Lake Restoration Program (ULRP) aiming to revive the lake was launched in 2013. Failure in megaprojects is common and frequent in which a high level of uncertainty is one of the main contributing factors. The purpose of this study...
Design of multi-service systems with facilities functioning as open Jackson queueing networks: application to online shopping stores
, Article OR Spectrum ; Volume 44, Issue 4 , 2022 , Pages 1255-1286 ; 01716468 (ISSN) ; Fathi, M ; Sharif University of Technology
Springer Science and Business Media Deutschland GmbH
2022
Abstract
This paper considers a realistic multi-service system design problem in which each service type is a stochastic sequence of services provided by different units of facilities where each facility is modeled as a set of open Jackson queueing networks. The problem is first formulated as a mixed-integer nonlinear programming model, which is further simplified to a model with a smaller number of constraints. Three exact solution methods are applied to solve the amended model. The first one is a cutting-plane method, which is based on a piecewise-linear approximation. The second is based on a mixed-integer linear programming formulation, which is enhanced by valid inequalities. The third is to use...
Null Controllability and Stabilizability of Compressible Navier-stokes System in One Dimension
, M.Sc. Thesis Sharif University of Technology ; Hesaraki, Mahmoud (Supervisor)
Abstract
In this thesis we study the exponential stabilization of the one dimensional compressible Navier-Stokes system, in a bounded interval locally around a constant steady state by a localized distributed control acting only in the velocity equation. In fact this is an analysis of a paper that published by Shirshendu Chowdhury, Debayan Maity, Mithily Ramaswamy and Jean-Pierre Raymond in Journal of Differential Equations. We determine a linear feedback law able to stabilize a nonlinear transformed system. Coming back to the original nonlinear system, we obtain a nonlinear feedback law able to stabilize locally this nonlinear system. The result is providing feedback control laws stabilizing...
Qualitative Modeling of Urban Stormwater and Reciever Lakes
, M.Sc. Thesis Sharif University of Technology ; Tajrishi, Masoud (Supervisor)
Abstract
Nowadays, urban storm water management and wastewater reuse are of main concerns of urban managers. Changes in surface specifications such as imperviousness, manning coefficient, pollutant buildup … during catchment transformation of land use from natural to urban can lead to undesirable change in quality and quantity of catchment's outlet runoff that could cause serious damage to receiving bodies. In recent decades, urban designing's approach has been using detention and quality improvement systems in order to manage urban runoff. Urban runoff and its treatment system (BMP: best management practices) and urban lake (as a receiving body) have been modeled in this research. Velenjak stream's...
Chaotic Network Flows in an Evolutionary Model of Traffic Assignment Based on Speed and Density
, M.Sc. Thesis Sharif University of Technology ; Poorzahedy, Hossein (Supervisor)
Abstract
Chaotic Flow in transportation networks has been the subject of several studies. Evolutionary models have been employed to simulate traffic flows. This study takes advantage of an existing evolutionary model of traffic assignment to show that chaotic phenomena arise when the model’s driving force is speed or density, of traffic flow. It has been observed that drivers show higher sensitivity when the network is more loaded.
Minimization Of of Environmental Impacts Of of Educational Buildings Using Life Cycle Analysis . A a Case Study: Building Of of Energy Engineering Faculty
, M.Sc. Thesis Sharif University of Technology ; Avami, Akram (Supervisor)
Abstract
Today, building sectors account for 34% of total energy consumption in Iran. Increasing demand of the comfort level along with population growth necessitates much more attention about energy requirements in the country. Such phenomenon has already raised concerns about the heavy environmental impacts. The present research studies minimization of global warming potential effect for an educational building by developing life cycle optimization model. The Department of Engineering of Sharif University of Technology is selected as the case study and optimal solutions has been achieved for this building. Results state that implementing cogeneration and renewable energies can reduce20 -25% of the...
Deblurring of Hyperspectral Images via Hyperspectral Unmixing
, M.Sc. Thesis Sharif University of Technology ; Amini, Arash (Supervisor)
Abstract
In this thesis, we propose a new compressed-sensing-based algorithm for unmixing of hyperspectral data, and show that the reconstruction quality could be significantly improved. In addition, we illustrate that by utilizing this approach, we can achieve an approximate estimation of the Point Spread Function (PSF) of the hyperspectral images. In this way, we first assume that the PSF belongs to a specific family of functions, such as Gaussian, then, by sweeping the parameters of the assumed PSF, we obtain the abundance coefficient matrix of the reconstructed image. Now, by choosing the sparsest coefficient matrix as the best one, we estimate the corresponding PSF. Then, we further investigate...
A Model for Analysis of Computational Learning
, M.Sc. Thesis Sharif University of Technology ; Daneshgar, Amir (Supervisor)
Abstract
The subject of this thesis is about a certain set of algorithms that try to indirectly solve problems. Instead of a programmer crafting an algorithm to solve a problem, these algorithms learn a solution themselves. These methods are usually studied in the Probably Accurately Correct (PAC) learning model. Although, PAC Learning is a generally accepted model, it falls short to describe certain aspects of learning algorithms. Many learning methods rely on convergence to minimize error, or maximize their fitness, yet the PAC model doesn’t explicitly provide any means to measure these behaviours. In this thesis, we first go through different models related to computational requirements of...
Design Principles of Permeable Pavement in Pollutants Removal from Surface Runoff
,
M.Sc. Thesis
Sharif University of Technology
;
Tajrishi, Agha Mohammad Hossein
(Supervisor)
Abstract
Urbanization increases impervious surfaces and therefore reduces land permeability. As a result, higher amount of runoff is produced which leads to environmental degradation and economic loss. Use of pervious/permeable pavements is an efficient approach to reduce runoff volume and improve the quality. In this study, different design methods of pervious/permeable surface are first described using structural and hydrological modules. Then, a software program for pervious/permeable surface design is put forth. Supported by various available design methods (focusing on pervious surfaces in Iran), the software employs structural, hydrological, economic (cost estimation) and qualitative...
Using Hydraulogical Model and Energy Balance in Estimating Groundwater Table, Case Study: Varamin Plain
, M.Sc. Thesis Sharif University of Technology ; Tajrishi, Masoud (Supervisor)
Abstract
Each country needs water for growing and developing. Water is necessary not only for expansion of cities and industries but also for agricultural development. Agriculture alone uses more than 90 percent of available water in our country. Water limitation and improper and noneconomic use of water are the main factors that limit agricultural development and food production in Iran. So taking appropriate decisions on this issue is necessary to optimize water use. Continuous assessment of water use at different levels in the basin, field and irrigation network is necessary for determining the current status and knowing its strengths and weaknesses and finding practical solutions to improve all...
Management of Dams Release According to Agricultural Water Needs with the Aim of Increasing Water Supply to Environmental Needs (A Case Study of Bukan Dam)
, M.Sc. Thesis Sharif University of Technology ; Tajrishi, Mohammad Massoud (Supervisor)
Abstract
The purpose of this research is to first provide an algorithm to reduce the scale of large-scale microwave soil moisture images and then develop an algorithm based on it to manage the release of dams downstream of which are agricultural lands and wetlands. Considering that providing irrigation needs is the purpose of building dams and agriculture is the main consumer of water in dams, optimizing the related releases has a significant effect on reducing water consumption and the possibility of releasing more water for water needs. It has a downstream environment, also agricultural water management has a direct impact on the production of agricultural products and preservation of natural...
Relationship between Dust Outbreaks and Soil Moisture in the Urmia Lake Periphery
, M.Sc. Thesis Sharif University of Technology ; Tajrishi, Masoud (Supervisor)
Abstract
Desiccation of different salty lakes around the world has been considered as one of the most critical environmental events. Gradual desiccation of the Lake Urmia and retreatment of its shoreline with respect to ecological level (1274.1 meters) have resulted in new hotspots for dust outbreaks, especially in east and south-east peripheries, which were previously under water. These areas, part of which are salty, are now exposed to open air and susceptible to wind-erosion. Soil moisture, as one of the most important parameters for dust prevention, determines the threshold friction wind speed over playa because it increases the cohesion between soil particles. Therefore, compared with dry soil,...