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Social and Behavioral Sciences Commons

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Selected Works

2013

Science and Technology Studies

Articles 1 - 7 of 7

Full-Text Articles in Social and Behavioral Sciences

Impact Of Wind Generator Control Strategies On Flicker Emission In Distribution Networks, Lasantha Meegahapola, Sarath Perera Dec 2013

Impact Of Wind Generator Control Strategies On Flicker Emission In Distribution Networks, Lasantha Meegahapola, Sarath Perera

Dr Lasantha G Meegahapola

Renewable power generators are increasingly being integrated to electricity networks to achieve future renewable energy targets in power generation. In particular, wind power generation has already reported substantial penetration levels in electricity networks. Traditionally, flicker phenomenon is considered to be one of the power quality issues in power distribution networks due to fluctuating consumer loads connected to the network. Large-scale integration of wind power generators may create significant voltage fluctuations in distribution feeders due to stochastic and intermittent nature of the wind resources. This study aims to investigate and characterize the flicker emission under different control strategies for DFIG based …


Capability Curve Based Enhanced Reactive Power Control Strategy For Stability Enhancement And Network Voltage Management, Lasantha Meegahapola, Tim Littler, Sarath Perera Dec 2013

Capability Curve Based Enhanced Reactive Power Control Strategy For Stability Enhancement And Network Voltage Management, Lasantha Meegahapola, Tim Littler, Sarath Perera

Dr Lasantha G Meegahapola

Reactive power has become a vital resource in modern electricity networks due to increased penetration of distributed generation. This paper examines the extended reactive power capability of DFIGs to improve network stability and capability to manage network voltage profile during transient faults and dynamic operating conditions. A coordinated reactive power controller is designed by considering the reactive power capabilities of the rotor-side converter (RSC) and the grid-side converter (GSC) of the DFIG in order to maximise the reactive power support from DFIGs. The study has illustrated that, a significant reactive power contribution can be obtained from partially loaded DFIG wind …


Dynamic Channel Allocation For Mobile Cellular Systems Using A Control Theoretical Approach, Yaya Wei, Chuang Lin, Raad Raad, Fengyuan Ren Oct 2013

Dynamic Channel Allocation For Mobile Cellular Systems Using A Control Theoretical Approach, Yaya Wei, Chuang Lin, Raad Raad, Fengyuan Ren

Dr Raad Raad

The guard channel scheme in wireless mobile networks has attracted and is still drawing research interest owing to easy implementation and flexible control. Dynamic guard channel schemes have already been proposed in the literature to adapt to varying traffic load. This paper presents a novel control-theoretic approach to dynamically reserve guard channels called PI-Guard Channel (PI-GC) controller that maintains the handoff blocking probability (HBP) to a predefined value; while it still improves the channel resource utilization.


Session Based Differentiated Quality Of Service Admission Control For Web Servers, Yaya Wei, Chuang Lin, Fengyuan Ren, Eryk Dutkeiwicz, Raad Raad Oct 2013

Session Based Differentiated Quality Of Service Admission Control For Web Servers, Yaya Wei, Chuang Lin, Fengyuan Ren, Eryk Dutkeiwicz, Raad Raad

Dr Raad Raad

Recent advance-session based admission control (SBAC) has resulted in protecting the server from entering a regime in which latencies are excessive or session throughput collapses due to dropped requests and aborted sessions. The goal of this work is to introduce differentiated QoS to SBAC. We propose a two-threshold SBAC scheme (QSBAC). It can provide high throughput for preferred clients especially in overload situation. Furthermore, to adapt to varying traffic loads, a dynamic QSBAC (DQSBAC) scheme is also proposed. The experimental results show that comparing with SBAC scheme, both QSBAC scheme and DQSBAC scheme can sustain higher session throughput for preferred …


Inertial Sensing For Human Motor Control Symmetry In Injury Rehabilitation, Matthew Field, David Stirling, Montserrat Ros, Zengxi Stephen Pan, Fazel Naghdy Oct 2013

Inertial Sensing For Human Motor Control Symmetry In Injury Rehabilitation, Matthew Field, David Stirling, Montserrat Ros, Zengxi Stephen Pan, Fazel Naghdy

zengxi pan

This paper proposes a series of methods for representing changes in human motion during injury rehabilitation using Micro-Electro-Mechanical Systems (MEMS) inertial sensors. Tracking the changes over a recovery period requires methods for evaluating the similarity of movement in an impaired state against a non-impaired state. We investigate the use of motion analyses such as the centre of mass (COM) tipping distance, the variance of joint velocity eigenvalues and the cumulative state changes of Gaussian mixture models (GMM) for monitoring the symmetry between the left and right sides of body during rehabilitation exercises. The methods are tested on an injured athlete …


Adaptive Sliding Mode Control Of Tri-Layer Conjugated Polymer Actuators, Xiangjiang Wang, Gursel Alici, Chuc Nguyen Jul 2013

Adaptive Sliding Mode Control Of Tri-Layer Conjugated Polymer Actuators, Xiangjiang Wang, Gursel Alici, Chuc Nguyen

Chuc Huu Nguyen

This paper proposes an adaptive sliding mode control methodology to enhance the positioning ability of conducting polymer actuators typified by tri-layer conjugated polymer actuators. This is motivated by the search for an effective control strategy to command such actuators to a desired configuration in the presence of parametric uncertainties and unmodeled disturbances. After analyzing the stability of the adaptive sliding mode control system, experiments were conducted to demonstrate its satisfactory tracking ability, based on a series of experimental results. Implementation of the control law requires a valid model of the conducting polymer actuator and boundaries of the uncertainties and disturbances. …


Integrated Seat And Suspension Control For A Quarter Car With Driver Model, Haiping Du, Weihua Li, Nong Zhang Feb 2013

Integrated Seat And Suspension Control For A Quarter Car With Driver Model, Haiping Du, Weihua Li, Nong Zhang

Professor Weihua Li

In this paper, an integrated vehicle seat and sus pension control strategy for a quarter car with driver model is proposed to improve suspension performance on driver ride comfort. An integrated seat and suspension model that includes a quarter-car suspension, a seat suspension, and a 4-degree-of freedom (DOM) driver body model is presented first. This in1 tegrated model provides a platform to evaluate ride comfort 1performance in terms of driver head acceleration responses under typical road disturbances and to develop an integrated control of seat and car suspensions. Based on the integrated model, an H∞ state feedback controller is designed …