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Full-Text Articles in Science and Technology Studies

The Ocean Thermal Energy Conversion Strategies And Analysis Of Current Challenges, Lasantha Meegahapola, Lanka Udawatta, Sanjeeva Witharana Dec 2013

The Ocean Thermal Energy Conversion Strategies And Analysis Of Current Challenges, Lasantha Meegahapola, Lanka Udawatta, Sanjeeva Witharana

Dr Lasantha G Meegahapola

This paper presents different roots of Ocean Thermal Energy Conversion (OTEC) strategies and challenges faced in terms of efficiency and economy of OTEC plants. The conversion strategies primarily focus on open cycle, closed cycle and hybrid plants. The efficiency studies mainly skew towards the effect of plant distance and thermal gradient towards plant efficiency. The economic analysis is based upon the effect of per unit cost for OTEC plant together with other important considerations such as Plant Factor (PF) and offshore distance, which determine the cost of power generation. Some illustrative examples are also provided using the derived equations under …


Comparative Analysis Of Dynamic Line Rating Models And Feasibility To Minimise Energy Losses In Wind Rich Power Networks, Mathew Simms, Lasantha Meegahapola Dec 2013

Comparative Analysis Of Dynamic Line Rating Models And Feasibility To Minimise Energy Losses In Wind Rich Power Networks, Mathew Simms, Lasantha Meegahapola

Dr Lasantha G Meegahapola

Wind power generation has indicated an exponential increase during last two decades and existing transmission network infrastructure is increasingly becoming inadequate to transmit remotely generated wind power to load centres in the network. The dynamic line rating (DLR) is one of the viable solutions to improve the transmission line ampacity during high wind penetration without investing on an additional transmission network. The main objective of this study is to identify the basic differences between two main line rating standards, since transmission network service providers (TNSPs) heavily depend on these two standards when developing their line rating models. Therefore, a parameter …


Transient Stability Analysis Of A Power System With High Wind Penetration, Lasantha Meegahapola, Damian Flynn, Tim Littler Dec 2013

Transient Stability Analysis Of A Power System With High Wind Penetration, Lasantha Meegahapola, Damian Flynn, Tim Littler

Dr Lasantha G Meegahapola

This paper presents transient stability analysis for a power system with high wind penetration. The transient stability has been evaluated based on two stability criteria: rotor angle stability and voltage stability. A modified IEEE-14 bus system has been used as the main study network and simulations have been conducted at several wind power penetration levels, defined as a fraction of total system generation. A wide range of scenarios have been presented based on the wind farm voltage at the point of connection, i.e. low voltage (LV) distribution level and high voltage (HV) transmission level, and the type of wind generator …


Flicker Propagation Analysis In Distribution Networks With Embedded Generation, D Perera, L Meegahapola, S Perera, P Ciufo Dec 2013

Flicker Propagation Analysis In Distribution Networks With Embedded Generation, D Perera, L Meegahapola, S Perera, P Ciufo

Dr Lasantha G Meegahapola

Embedded generators such as wind generators can produce observable voltage fluctuations during variable wind conditions hence flicker. The flicker produced by such intermittent and fluctuating generating sources can propagate to other parts of the distribution network while creating power quality issues in distribution feeders. This study presents a flicker emission analysis for a doubly-fed induction generator (DFIG) based wind farm and investigate the pertinent factors which influence flicker propagation and attenuation in distribution feeders. Study has shown that voltage fluctuations are significantly influenced by the attenuation characteristics of various load types (i.e. constant power, impedance and current loads) connected to …


Performance Analysis Of Stfc Mb-Ofdm Uwb In Wban Channels, Miftadi Sudjai, Le Chung Tran, Farzad Safaei Jun 2013

Performance Analysis Of Stfc Mb-Ofdm Uwb In Wban Channels, Miftadi Sudjai, Le Chung Tran, Farzad Safaei

Professor Farzad Safaei

This paper investigates the performance of the space-time-frequency coded (STFC) multiband orthogonal frequency division multiplexing ultra-wideband (MBOFDM UWB) system over wireless body area network (WBAN) channels, using the Alamouti code. Different MIMO configurations and different modulations are used for comparison. The effect of body directions is also assessed by simulation in this paper. Simulation results show that the proposed STFC MB-OFDM UWB system provides a significantly better BER performance, compared to the conventional MB-OFDM system, even from a reasonably low Eb/No range. The simulations also confirm that the body direction affects the system performance significantly due to the availability of …


Analysis Combining Survey And Geographically Aggregated Data, David Steel, Mark Tranmer, D Holt Jun 2013

Analysis Combining Survey And Geographically Aggregated Data, David Steel, Mark Tranmer, D Holt

Professor David Steel

This chapter contains sections titled: Introduction and Overview Aggregate and Survey Data Availability Bias and Variance of Variance Component Estimators Based on Aggregate and Survey Data Simulation Studies Using Auxiliary Variables to Reduce Aggregation Effects Conclusions Acknowledgements


Flicker Propagation Analysis In Distribution Networks With Embedded Generation, D Perera, L Meegahapola, S Perera, P Ciufo Feb 2013

Flicker Propagation Analysis In Distribution Networks With Embedded Generation, D Perera, L Meegahapola, S Perera, P Ciufo

Dr Philip Ciufo

Embedded generators such as wind generators can produce observable voltage fluctuations during variable wind conditions hence flicker. The flicker produced by such intermittent and fluctuating generating sources can propagate to other parts of the distribution network while creating power quality issues in distribution feeders. This study presents a flicker emission analysis for a doubly-fed induction generator (DFIG) based wind farm and investigate the pertinent factors which influence flicker propagation and attenuation in distribution feeders. Study has shown that voltage fluctuations are significantly influenced by the attenuation characteristics of various load types (i.e. constant power, impedance and current loads) connected to …


Location And Tracking Of Mobile Devices: Überveillance Stalks The Streets, Katina Michael, Roger Clarke Dec 2012

Location And Tracking Of Mobile Devices: Überveillance Stalks The Streets, Katina Michael, Roger Clarke

Professor Katina Michael

During the last decade, location-tracking and monitoring applications have proliferated, in mobile cellular and wireless data networks, and through self-reporting by applications running in smartphones that are equipped with onboard global positioning system (GPS) chipsets. It is now possible to locate a smartphone-user's location not merely to a cell, but to a small area within it. Innovators have been quick to capitalise on these location-based technologies for commercial purposes, and have gained access to a great deal of sensitive personal data in the process. In addition, law enforcement utilise these technologies, can do so inexpensively and hence can track many …