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mirzaei-rashid--javad
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Total 391 records
Analysis of Autonomous Takeoff and Landing of a Tailsitter on Moving Platform
, M.Sc. Thesis Sharif University of Technology ; Banazadeh, Afshin (Supervisor)
Abstract
The purpose of this research is to add automatic landing and takeoff capability to the target drone. To design the automatic landing and takeoff algorithm and analyze and check its performance quality, the target drone must be modeled first. Since this drone has a relatively large blade, the dynamic effects of this large blade are included in the modeling. After modeling the drone, the controller has been designed for three phases of horizontal flight, vertical flight and the transition between these two flight phases. With the preparation of the controllers of different phases of flight, the automatic landing and takeoff algorithm of the flying drone is designed, implemented and its results...
Transient analysis of injection-locked frequency dividers
, Article 2002 45th Midwest Symposium on Circuits and Systems, Tulsa, OK, 4 August 2002 through 7 August 2002 ; Volume 3 , 2002 , Pages III381-III384 ; Sharif University of Technology
2002
Abstract
Injection locked frequency dividers (ILFD) are used for frequency division to reduce the overall power consumption. By injecting a high frequency signal to an LC oscillator, injecting signal gets synchronous with oscillator output. All ILFDs analysis reports are based on steady state solution when locking is reached. At the same time, it is important to consider transient analysis too. In this paper a simple model is developed to study phase transient analysis when injecting signal is small in amplitude. This model can be used for large signal injection as a good approximation
A very low power CMOS, 1.5V, 2.5GHz prescaler
, Article 2002 45th Midwest Symposium on Circuits and Systems, Tulsa, OK, 4 August 2002 through 7 August 2002 ; Volume 3 , 2002 , Pages III378-III380 ; Sharif University of Technology
2002
Abstract
A very low power CMOS, 1.5V, 2.5GHz prescaler was designed. Implemented in 0.25u standard CMOS technology, this prescaler can operate up to 3GHz range. The prescaler consists of three delay flip flops (DFF) that work synchronously with RF sinusoidal clock and divides by 4 or 5 according to control signal
A 5 GHz, 1.5 Volt and very low-power cmos frequency synthesizer for wireless communications
, Article 2002 45th Midwest Symposium on Circuits and Systems, Tulsa, OK, 4 August 2002 through 7 August 2002 ; Volume 3 , 2002 , Pages III536-III539 ; Sharif University of Technology
2002
Abstract
A 5GHz, 1.5 Volt and low power CMOS frequency synthesizer with LC-tuned VCO (voltage controlled oscillator) is presented. The synthesizer consists of an LC-tuned VCO, an injection-lock frequency divider, a very low power prescaler which brings 2.5GHz range frequency to 11 MHz, a phase-frequency detector and charge-pump with improved architecture. Spiral inductors with Q-factor of 9 are used for the LC-tuned 5 GHz VCO. A fixed 2 frequency divider based on injection-locking phenomenon is used to bring 5 GHz VCO frequency to 2.5GHz. Both VCO and injection-locked divider's oscillators are tuned with NMOS varactors with their bodies are grounded, resulting in about 700 MHz tuning range....
Conflation of technology and language: a cognitive artifact
, Article Technology and Language ; Volume 4, Issue 1 , 2023 , Pages 93-110 ; 27129934 (ISSN) ; Sharif University of Technology
St. Petersburg Polytechnic University of Peter the Great
2023
Abstract
We use concepts to make distinctions. Blurring these distinctions results in conflations. So, they are commonly seen as vicious. The claim here is that, by contrast, conflations are virtuous because they can do cognitive work. They enrich our conceptual resources. It is not conflation per se that is destructive but the lack of evaluation. Committing a conflation requires two cognitive acts at once. First, keeping things together and, second, appreciating the gap between them. Conflation thus has a family resemblance with notions like analogy and metaphor. Despite their apparent difference, a shared trait is recognizable in this family: the simultaneous maintenance of similarity and...
The affinity between feedback mechanism and hermeneutical circle
, Article Technology and Language ; Volume 5, Issue 1 , 2024 , Pages 37-52 ; 27129934 (ISSN) ; Sharif University of Technology
2024
Abstract
Hermeneutics traditionally revolves around human experiences and sense-making, often considered distinct from the scientific and technological realms of non-human experimentation and tool-making. This contrast between the humane and the artifactual or the natural, associated with understanding and interpretation on the side of the former and control and experimentation on the other, creates what might be termed a Diltheyan wound. This paper aims to find a remedy for this wound by revealing the affinity between two pivotal concepts in engineering and the humanities: the feedback mechanism and the hermeneutical circle. Investigating their relationship at historical and conceptual levels, we...
A fuzzy random minimum cost network flow programming problem [electronic resource]
, Article Journal of Industrial and Systems Engineering (JISE)-Iranian Institute of Industrial Engineering ; Article 3, Volume 6, Issue 1, Spring 2012, Page 34-47 ; Eshghi, Kourosh ; Sharif University of Technology
Abstract
In this paper, a fuzzy random minimum cost flow problem is presented. In this problem, cost parameters and decision variables are fuzzy random variables and fuzzy numbers respectively. The object of the problem is to find optimal flows of a capacitated network. Then, two algorithms are developed to solve the problem based on Er-expected value of fuzzy random variables and chance-constrained programming. Furthermore, the results of two algorithms will be compared. An illustrative example is also provided to clarify the concept
Special classes of mathematical programming models with fuzzy random variables [electronic resource]
, Article Journal of Intelligent and Fuzzy Systems, Published In: IOS Press ; Volume 19, Number 2, 2008 ; Nematian, Javad ; Sharif University of Technology
Abstract
In this paper, we will discuss two special classes of mathematical programming models with fuzzy random variables. In the first model, a linear programming problem with fuzzy decision variables and fuzzy random coefficients is introduced. Then an algorithm is developed to solve the model based on fuzzy optimization method and fuzzy ranking method. In the second model, a fuzzy random quadratic spanning tree problem is presented. Then the proposed problem is formulated and solved by using the scalar expected value of fuzzy random variables. Furthermore, illustrative numerical examples are also given to clarify the methods discussed in this paper
A special class of fuzzy integer programming model with all different constraints [electronic resource]
, Article Scientia Iranica ; Vol. 16, No. 1, pp. 1-10, 2009 ; Nematian, Javad ; Sharif University Of Technology
Abstract
In this paper, a fuzzy approach is applied to special classes of integer programming problems with all diierent constraints. In the rst model, a fuzzy integer programming model is developed to represent the all-diierent constraints in mathematical programming. In order to solve the proposed model, a new branching scheme for the Branch and Bound algorithm is also presented. In the second model, a special class of large-scale multi-objective fuzzy integer programming problems with all-diierent constraints is introduced. A solution method for the proposed model is also developed by using the decomposition technique, weighting method and Branch and Bound algorithm. An illustrative numerical...
Fuzzy random minimum cost network problem [electronic resource]
, Article Journal of Industrial and Systems Engineering ; Vol. 6, No. 1, pp 34-47, 2012 ; Eshghi, Kourosh ; Sharif University of Technology
Abstract
In this paper, a fuzzy random minimum cost flow problem is presented. In this problem, cost parameters and decision variables are fuzzy random variables and fuzzy numbers respectively. The object of the problem is to find optimal flows of a capacitated network. Then, two algorithms are developed to solve the problem based on Er-expected value of fuzzy random variables and chance-constrained programming. Furthermore, the results of two algorithms will be compared. An illustrative example is also provided to clarify the concept
Prediction of CO2-Brine interfacial tension using a rigorous approach
, Article Journal of Natural Gas Science and Engineering ; Volume 45 , 2017 , Pages 108-117 ; 18755100 (ISSN) ; Harimi, B ; Hamidpour, E ; Sharif University of Technology
Elsevier B.V
2017
Abstract
Geologic sequestration of CO2 in deep saline aquifers is becoming increasingly important as a method with the greatest potential to economically sequester large volumes of anthropogenic CO2. The interfacial tension (IFT) between the formation brine in the aquifer and the injected CO2 phase has a significant influence on the displacement, and its precise determination is essential for accurate modeling and evaluation of such a process. This paper presents two new mathematical models to calculate the brine/CO2 IFT. The two models differ in input parameters; pressure, temperature, and salinity for the first model, and pressure, temperature, and brine composition for the second one. The proposed...
Quality evaluation of Jajrood river (IRAN) by quality indices methods
, Article 2012 International Conference on Advances in Materials Science and Engineering, AMSE 2012, Seoul, 9 December 2012 through 10 December 2012 ; Volume 650 , 2013 , Pages 652-657 ; 10226680 (ISSN); 9783037855997 (ISBN) ; Hasanian, H ; Sharif University of Technology
2013
Abstract
This Regular evaluation and analysis of river quality helps accurate management to reach acceptable quality. In this study, water quality indices (WQI) method applied to evaluate quality of Jajrood River which is one of the main sources of Tehran drinking water. It helps to subsidize management actions in Jajrood watershed. Sampling carried out for 9 years during 2001-2010 in 10 stations along the river in wet and dry stations to identify water quality and the main source of pollution. Results show water quality in all stations classifies as medium according to National Sanitation Foundation (NSF) and water quality index in wet season is better than the corresponding value in dry seasons....
Exception fault localization in android applications
, Article Proceedings - 2nd ACM International Conference on Mobile Software Engineering and Systems, MOBILESoft 2015, 16 May 2015 through 17 May 2015 ; 2015 , Pages 156-157 ; 9781479919345 (ISBN) ; Heydarnoori, A ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2015
Abstract
In software programs, most of the time, there is a chance of error, even though they are tested carefully. Finding error-related pieces of code is one of the most complicated tasks and it can make incorrect results if done manually. Semi-automated and fully-automated methods have been introduced to overcome this issue. The rapid growth of developing Smart Mobile Applications (SMAs) in recent years, competition among the development teams and many other factors have increased the chance of errors, and hence, the quality of these applications have reduced. There are two approaches to test SMAs in order to reach a high degree of quality: (i) using existing traditional methods and adapting them...
Localizing exception faults in Android applications
, Article Scientia Iranica ; Volume 26, Issue 3 D , 2019 , Pages 1567-1588 ; 10263098 (ISSN) ; Heydarnoori, A ; Sharif University of Technology
Sharif University of Technology
2019
Abstract
In software programs, most of the time, there is a chance for occurrence of faults in general, and exception faults in particular. Localizing those pieces of code that are responsible for a particular fault is one of the most complicated tasks, and it can produce incorrect results if done manually. Semi-automated and fully-automated techniques have been introduced to overcome this issue. However, despite recent advances in fault localization techniques, they are not necessarily applicable to Android applications because of their special characteristics such as context-awareness, use of sensors, being executable on various mobile devices, limited hardware resources, etc. To this aim, in this...
Localizing exception faults in Android applications
, Article Scientia Iranica ; Volume 26, Issue 3 D , 2019 , Pages 1567-1588 ; 10263098 (ISSN) ; Heydarnoori, A ; Sharif University of Technology
Sharif University of Technology
2019
Abstract
In software programs, most of the time, there is a chance for occurrence of faults in general, and exception faults in particular. Localizing those pieces of code that are responsible for a particular fault is one of the most complicated tasks, and it can produce incorrect results if done manually. Semi-automated and fully-automated techniques have been introduced to overcome this issue. However, despite recent advances in fault localization techniques, they are not necessarily applicable to Android applications because of their special characteristics such as context-awareness, use of sensors, being executable on various mobile devices, limited hardware resources, etc. To this aim, in this...
Microstructure evolution mechanism and corrosion behavior of transient liquid phase bonded 304l stainless steel
, Article Metals and Materials International ; Volume 27, Issue 9 , 2021 , Pages 3417-3431 ; 15989623 (ISSN) ; Binesh, B ; Sharif University of Technology
Korean Institute of Metals and Materials
2021
Abstract
Abstract: Transient liquid phase (TLP) bonding of 304L austenitic stainless steel was carried out using MBF-20 interlayer at 1070 °C with different holding times. The effect of bonding time on the microstructure and corrosion resistance of the TLP bonded samples was investigated aiming to obtain the optimal bonding time. The results showed that isothermal solidification was completed within 45 min at 1070 °C and shorter holding times gave rise to the formation of intermetallic compounds at the joint centerline. It was found that the solidification sequence in the joint region is as follows: (1) isothermal solidification of γ solid solution, (2) formation of ternary eutectic of γ + Ni boride...
Exception Fault Localization in Smart Mobile Applications
, M.Sc. Thesis Sharif University of Technology ; Heydarnoori, Abbas (Supervisor)
Abstract
In software programs, most of the time, there is a chance of error, even though they are tested carefully. Finding error-related pieces of code is one of the most complicated tasks and it can make incorrect results if done manually. Semi-automated and fully-automated methods have been introduced to overcome this issue. The rapid growth of developing smart mobile applications (SMAs) in recent years, competition among the development teams and many other factors have increased the chance of errors and hence, the quality of these applications have reduced. There are two approaches to test SMAs in order to reach a high degree of quality: (1) using existing traditional methods and adapting them...
Codification of Reliability Evaluation Software in UAVs Industry
, M.Sc. Thesis Sharif University of Technology ; Banazadeh, Afshin (Supervisor)
Abstract
In every modern society, the engineers and technical managers are in charge of planning, designing, manufacturing and utilizing the simplest products to the most complex systems. This shows the importance of reliability management in engineering systems. Inattention to the reliability of such systems leads to the difficulty or even impossibility in planning or utilizing them. Malfunction of products and systems results in disruption in different levels and can be regarded as a severe threat to society and environment.
Therefore, consumers and general public expect products and systems to be durable, reliable and safe. Thus, the main question is how safe and how reliable the system will...
Therefore, consumers and general public expect products and systems to be durable, reliable and safe. Thus, the main question is how safe and how reliable the system will...
Preparation and Characterization of Supercapacitor Nanocomposites Based on Polyaniline and Hybrid of Nano Metal/Metal Oxide Particles
, M.Sc. Thesis Sharif University of Technology ; Shojaei, Akbar (Supervisor)
Abstract
Supercapacitors are one of the most important energy storage devices that have been researched with respect to the development of hybrid cars. Polymer composites have received much attention due to the electrochemical properties of conductive polymers and the synergistic effects of the composite components. In the present Thesis, in order to investigate the synergistic effect of gold nanoparticles with MnO2 nanorods as a metal oxide and polyaniline as a conductive polymer and graphene as a carbon material, two groups of composites were synthesized in the presence and absence of graphene. Characterization of the electrode material is carried out by XRD, FT-IR and FE-SEM tests. The...
Evaluating the Independence and Accountability of the National Competition Council Based on Principal-Agent Theory
, M.Sc. Thesis Sharif University of Technology ; Shadnam, Masoud (Supervisor)
Abstract
Following the rise of the regulatory state and the proliferation of regulatory agencies around the world, Iran is also experiencing such an evolving landscape in the machinery of public sector towards a specific form of regulatory state. The establishment of the National Competition Council in the late 1380s is definitely one of the most prominent points of this evolutionary path; An institution that is the best example of an Independent Regulatory Agency (IRA) in Iran. In general, independence is considered one of the most fundamental institutional features of regulatory agencies, which brings many benefits, but due to the non-election and non-democratic nature of independent regulatory...