Sharif Digital Repository

In the last decade, the developement of Quantum Information theory have created new concepts and methods in the study of quantum many-body systems, that previously weren’t available to physicist involved in areas such as condensed matter and field theory. One of the most important steps is the insight provided by structure of the many body system’s Hilbert space. Although, it is not completed, it leads us to deep results.In fact, we have found out that with high probability, the state of a many-body system is located in a very small corner of the Hilbert space, which requires only a small number of parameteres to describe it, that with respect to the number of particles, it grows linearly... 

In this thesis we are going to improve an ultrasonic flowmeter accuracy by considering the influence of different parameters like temperature, pressure, etc. Firstl of all different cases of flow condition in which ultrasonic flowmeter may work are specified, then velocity and temperature profile of pipe flow are determined using Fluent software. In thr next step ultrasonic pulses transmitted are simulated by the use of code written in Matlab to find wave travel time in the flow. Evetually an accurate relation of calibration for flowmeter is determined by the use of travel time and all other flow properties to evaluate the accuracy of flowmeter in diffent cases. Relation extracted can be... 

Embedded system Project management , because of lots of unstable parameters in design and also diversity of the technical knowledge ,requires a complex and agile project management methodology. Whereas in these projects , different knowledge fields are applied (such as electronics ,telecommunication ,control and robotics) and software is an evitable part of these systems ,project managers can not be familiar with all aspects of the technical and professional in deep manner. Considering that usually ,the project managers of such projects are elected from professionals of hardware or mechanical sections and not in deep inception of software project management , this thesis focus on a new model... 

In this thesis, the value-ladenness or value-neutrality of technology, new social media and as a result Instagram is investigated. It is also discussed whether values can be taken into account during the design process of technical artefacts, including new social media and Instagram, and methods are developed for this purpose. Several methods have been developed for this purpose, some of them and their compatibility with modern social media are explained; including the Value-Sensitive-Design method and the disclosive computer ethics design method. The frameworks of ethical philosophy such as virtue ethics are reviewed and the appropriate ethical framework for the analysis of new social media... 

Injection of liquid fuel in the cross-flowing air provides a means of higher penetration, rapid mixing of liquid fuel and air, and is encountered in many engineering applications. Air-breathing propulsion systems (e.g. gas turbine combustors, ramjets, and scramjets), liquid rocket engines,cooling sprays for turbine blades, and injection of fuel in the afterburners are examples of such applications. The identification of microscopic characteristics is one of the basic methods of atomizer examination, which has not been taken into account due to inadequate experimental equipment. In the present study, droplet mono-frame velocimetry and size distribution of secondary atomization in a pressure... 

Simultaneous development of technology and social networks and universal access to them caused to produce and distribute huge volume of videos that recognition of their content without use of machine vision is very hard. This thesis examine some video classification algorithms to improve them. The algorithm that is used to improve is based on one of local descriptor algorithms. At first with using STIP tools, the local interest point found by Harris3d and describe by HOG/HOF. Then by using Bag of Features, all local descriptors in a video produce a descriptor per videos. Bag of Features divide the domain of all local descriptors from all videos to K cluster and produce a vector per video... 

Considering the high penetration of renewable energy resources in modern power systems, independent system operator faces considerable uncertainty and variability in the system under supervision. In this regard, determining and providing the appropriate amount of operational reserve is critical to overcoming uncertainty and variability to have reliable system performance. In practice, power system operators prefer to use deterministic approaches to schedule operational reserve. Such approaches have benefits in simplicity and fast calculations. Nevertheless, increasing share of renewable resources causes a considerable error in these approaches. Therefore, many researchers have proposed... 

Today, energy crises and the environmental pollution have become serious problems for the human being. To address these problems, extensive efforts have been made to replace fossil fuels with other clean energy resources such as fuel cells. In the meantime, polymer electrolyte fuel cells are very important as they are now commonly used in the field of transportation, and their importance become even more obvious as we consider the fact that the by-products from electricity production by such cells are simply water and heat. This research studies the efficiency of the polymer called “polysulfone” as an electrolyte fuel cell, which has the above named mechanical thermal and chemical... 

Nowadays, according to increasing development of construction industry in the world especially in the building area, the need to use technology and innovation for fabrication and maintenance of this industry has increased. And this fact becomes apparent that the use of traditional systems of construction isn’t tailored the countries’ requirements anymore. One of the construction industry’s limitations is the restrictions on architectural designs reys. The columns are among the most important components of structure and have a major role in bearing all gravity and lateral loads and transferring them to the foundation. The failure or destruction of the components in the structure under applied...