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Full-Text Articles in Physical Sciences and Mathematics

Traffic Modeling In Lagrangian Coordinates Using Smartphone Apps, Sergio Contreras May 2013

Traffic Modeling In Lagrangian Coordinates Using Smartphone Apps, Sergio Contreras

UNLV Theses, Dissertations, Professional Papers, and Capstones

Traditionally, one of the ways traffic flow has been studied is by using the kinematic wave model. This model is derived in the Eulerian framework by using conservation of the number of vehicles. Recently, the kinematic wave model has been transformed into Lagrangian coordinates. In this framework, the independent variables are unique

vehicles and time. The detailed change in framework, and the properties of the model in the changed framework are reviewed. Numerical results from different traffic cases are explained. Since vehicle trajectory data can be easily collected from smartphones,

a smartphone application is developed for this purpose. This data …


Stochastic Modeling And Time-To-Event Analysis Of Voip Traffic, Imad Al Ajarmeh Mar 2013

Stochastic Modeling And Time-To-Event Analysis Of Voip Traffic, Imad Al Ajarmeh

College of Computing and Digital Media Dissertations

Voice over IP (VoIP) systems are gaining increased popularity due to the cost effectiveness, ease of management, and enhanced features and capabilities. Both enterprises and carriers are deploying VoIP systems to replace their TDM-based legacy voice networks. However, the lack of engineering models for VoIP systems has been realized by many researchers, especially for large-scale networks. The purpose of traffic engineering is to minimize call blocking probability and maximize resource utilization. The current traffic engineering models are inherited from the legacy PSTN world, and these models fall short from capturing the characteristics of new traffic patterns. The objective of this …


Simulation Of Discrete Electromagnetic Propagation Model For Atmospheric Effects On Mobile Communication, Şaban Seli̇m Şeker, Fulya Kunter Jan 2013

Simulation Of Discrete Electromagnetic Propagation Model For Atmospheric Effects On Mobile Communication, Şaban Seli̇m Şeker, Fulya Kunter

Turkish Journal of Electrical Engineering and Computer Sciences

Wireless communication has become an important part of our lives, and atmospheric effects are one of the ultimate factors affecting quality of communication and satellite systems. In this study the attenuation in mobile communication due to atmospheric events like snow and rain is simulated using the discrete propagation model. In this work, spherical raindrop and oblate spheroid raindrop modeling are used. To check the validity of simulations, the commonly used and accepted ITU-R rain model is used. Oblate spheroid raindrop modeling produces results that are more compatible with ITU-R results, especially at frequencies higher than 50 GHz. At lower frequencies, …


Simulation Of A Large Electric Distribution System Having Intensive Harmonics In The Industrial Zone Of Konya, Hasan Eroğlu, Musa Aydin Jan 2013

Simulation Of A Large Electric Distribution System Having Intensive Harmonics In The Industrial Zone Of Konya, Hasan Eroğlu, Musa Aydin

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, measurements were taken at different points of a sample distribution system in order to analyze the levels of harmonics that appear as a day-to-day increasing problem in electrical distribution systems. According to the measurement values, the dominant harmonics have been determined and an electrical model of the system has been prepared using the SimPowerSystems toolbox from MATLAB and Simulink. The accuracy of the electrical model has been verified by the measurement and simulation values. In addition, the transformer connection types' and impedances' simulations have been presented to understand and solve the harmonic problems in electrical distribution systems. …


Simulation Of Transient Processes On Overvoltage In Electric Transmission Lines Using Atp-Emtp, Ahmet Nayi̇r Jan 2013

Simulation Of Transient Processes On Overvoltage In Electric Transmission Lines Using Atp-Emtp, Ahmet Nayi̇r

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, the mathematical modeling and simulation of electromagnetic transient processes is considered, which is of vital importance for examining the overvoltage phenomenon of power transmission systems. In the mathematical models of the AC power transmission systems that contain a power source, the power transformer, transmission line, and power autotransformer block are presented. The mathematical model of each system component is obtained based on the branch voltages, flux linkages, and branch voltages of the magnetic circuits individually. As for the simulation, an alternative transient program (ATP) environment is used to model the electric power system's elements. One of the …