Sharif Digital Repository

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... 

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... 

Reinforced concrete shells are widely used to cover the small to large area with more aesthetics at minimum cost. Shell structures carry load through their shape rather than material strength. Funicular shells are special type of shells that their shape is obtained so that stresses be compressive under a special load (for shell, this load is its dead weight). This study deals with geometrically nonlinear vibration of funicular shells on a rectangular ground plan under impulse loads using nonlinear shallow shells theory. The boundary conditions are considered as clamped edges. Displacement components are product of position and time functions. The analysis is based on the expansion of... 

A swarm robotic is made up of a number of similar robots (identical) that these robots alone do not have any potential, but they can with each other have considerable potential. In recent years, engineers have become more interested in swarm robotic. Swarm robotic allows the use of several colleague robots instead of an advanced robot that eliminates excessive complexity and expensive equipment. The purpose of this study is to provide a method for solving the crossing problem and interfering between robot swarms. In previous studies conducted at the Sharif University of Technology, the main goal was to design algorithms for the swarm behavior of a swarm robotic. In this research, the aim is... 

Software defined networks are developed to provide programmability and a centralized view in networks by decoupling control plane from data plane. Software defined networks are now well received,and these networks are evolving every day. This is while more attention has been paid to widen the application of these networks and eliminating the shortcomings in their performance. On the other hand, in very large networks, the issue of efficiency and processing speed is of great importance. However, performance in these networks is not satisfactory, especially in single controller based SDN due to the complex processing of packets in a unique controller. Security needs are also of great... 

Single molecule magnets due to their magnetic tunneling effect and the interaction they have with an external magnetic field are used widely in quantum computing and also the storage of data with high capacities. Polyoxometalates that are used as counter ions for cationic single molecule magnets, are able to affect their spin-couple nature via a magnetic exchange and also have an influence on the crystal accumulation in order to change the magnetic property of the molecule. In this research the probability of sedimenting a cationic single molecule magnet, [Mn4O2(CH3COO)7(bipy)2]+, with the use of anionic polyoxometalates with Keggin structures has been investigated. Thus, the single... 

For along time, analysis of financial markets is an interesting topic for mankind. There are different statistical methods to analyze financial time series. In this manuscript, financial markets are analyzed from network view point. Inference of hidden structures between companies of a market is merit information so we introduce different methods to infer
hidden network structure of financial markets. In addition, we will show that dynamic of network structure can provide important information about external sources of influence on financial markets. Actually, we show affect of political events on financial market of Iran. At last, we generalize diffusion concept at financial networks...