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Optimisation

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Full-Text Articles in Engineering

Tidal Current Turbine Blade Optimisation With Improved Blade Element Momentum Theory And A Non-Dominated Sorting Genetic Algorithm, Eng Jet Yeo, David Kennedy, Fergal O'Rourke Jan 2022

Tidal Current Turbine Blade Optimisation With Improved Blade Element Momentum Theory And A Non-Dominated Sorting Genetic Algorithm, Eng Jet Yeo, David Kennedy, Fergal O'Rourke

Articles

Tidal current energy has the advantage of predictability over most of the other renewable energy resources. However, due to the harsh operating environment and complicated site conditions, developments in this domain have been gradual. Paramount to these points is device design and optimisation of hydrodynamic performance. Recent developments in the correction models of BEM theory have further improved the accuracy of the prediction model. Using an improved blade element momentum theory model that is capable of accurately capturing the downwash angle and combining it with a well-developed and reliable non-dominated sorting genetic algorithm model, an effective and efficient tidal current …


Evaluation Of Hydrometric Network Efficacy And User Requirements In The Republic Of Ireland Via Expert Opinion And Statistical Analysis, Paul Hynds, Ahmed Nasr, Jean O'Dwyer Jan 2019

Evaluation Of Hydrometric Network Efficacy And User Requirements In The Republic Of Ireland Via Expert Opinion And Statistical Analysis, Paul Hynds, Ahmed Nasr, Jean O'Dwyer

Articles

Decreased funding and shifting governmental priorities have resulted in a contraction of hydrometric measurement in many regions over the past two decades. Moreover, concerns exist with respect to appropriate data usage and (transboundary) exchange, in addition to the compatibility and extent of existing hydrometric datasets. These issues are undoubtedly magnified due to enhanced data demands and increased financial pressures on network managers, thus requiring new approaches to optimising the societal benefits and overall efficacy of hydrometric information for future socio-hydrological resilience. The current study employed a quantitative cross-sectional expert elicitation of 203 respondents to collate, analyse and assess hydrometric network …


Joint Power Allocation In Interference-Limited Networks Via Distributed Coordinated Learning, Roohollah Amiri, Hani Mehrpouyan, David Matolak, Maged Elkashlan Jan 2018

Joint Power Allocation In Interference-Limited Networks Via Distributed Coordinated Learning, Roohollah Amiri, Hani Mehrpouyan, David Matolak, Maged Elkashlan

Electrical and Computer Engineering Faculty Publications and Presentations

Dense deployment of small base stations (SBSs) is one of the main methods to meet the 5G data rate requirements. However, high density of independent SBSs will increase the interference within the network. To circumvent this interference, there is a need to develop self-organizing methods to manage the resources of the network. In this paper, we present a distributed power allocation algorithm based on multi-agent Q-learning in an interference-limited network. The proposed method leverages coordination through simple message passing between SBSs to achieve an optimal joint power allocation. Simulation results show the optimality of the proposed method for a …


Ultra-Wideband Antennas, Max Ammann, Matthias John, Giuseppe Ruvio Jan 2016

Ultra-Wideband Antennas, Max Ammann, Matthias John, Giuseppe Ruvio

Books/Book chapters

The focus of UWB antenna research activity has matured in recent years and currently mainly concentrates on applications such as biomedicine and security. Early UWB antenna designs were driven by the FCC allocation of spectrum in 2002 and focussed on obtaining wide impedance bandwidths with reasonable group delay characteristics. Many of these were simple planar monopoles antennas with canonical geometries. The emergence of new applications channelled the emphasis towards miniaturisation and integration into devices. This required optimisation of the antenna geometries to ensure that good system performance is achieved from the integrated antenna. Many optimisation techniques are available including the …


Shape Optimisation Of Cold-Formed Steel Columns With Manufacturing Constraints Using The Hough Transform, Bin Wang, Benoit P. Gilbert, Adrien M. Molinier, Hong Guan, Lip H. Teh Jan 2016

Shape Optimisation Of Cold-Formed Steel Columns With Manufacturing Constraints Using The Hough Transform, Bin Wang, Benoit P. Gilbert, Adrien M. Molinier, Hong Guan, Lip H. Teh

Faculty of Engineering and Information Sciences - Papers: Part A

This paper introduces manufacturing constraints into a recently developed evolutionary algorithm for shape optimisation of CFS profiles. The algorithm is referred to as "self-shape optimisation" and uses Genetic Algorithm (GA) together with the Augmented Lagrangian (AL) method to avoid ill-conditioned problems. Simple manufacturing rules derived from the limitations of current cold-forming processes, i.e. a limited ability to form continuously curved surfaces without discrete bends, are described in the paper and incorporated into the algorithm. The Hough transform is used to detect straight lines and transform arbitrarily drawn cross-sections into manufacturable ones. Firstly, the algorithm is verified against a known optimisation …


A Heuristic Combinatorial Optimisation Approach To Synthesising A Population For Agent-Based Modelling Purposes, Nam N. Huynh, Johan Barthelemy, Pascal Perez Jan 2016

A Heuristic Combinatorial Optimisation Approach To Synthesising A Population For Agent-Based Modelling Purposes, Nam N. Huynh, Johan Barthelemy, Pascal Perez

SMART Infrastructure Facility - Papers

This paper presents an algorithm that follows the sample-free approach to synthesise a population for agent based modelling purposes. This algorithm is among the very few in the literature that do not rely on a sample survey data to construct a synthetic population, and thus enjoy a potentially wider applications where such survey data is not available or inaccessible. Different to existing sample-free algorithms, the population synthesis presented in this paper applies the heuristics to part of the allocation of synthetic individuals into synthetic households. As a result the iterative process allocating individuals into households, which normally is the most …


The Optimisation Of The Secondary Cooling Water Distribution With Improved Genetic Algorithm In Continuous Casting Of Steels, Yu-Chun Zhai, Ying Li, Beiyue Ma, C Yan, Zhengyi Jiang Jan 2015

The Optimisation Of The Secondary Cooling Water Distribution With Improved Genetic Algorithm In Continuous Casting Of Steels, Yu-Chun Zhai, Ying Li, Beiyue Ma, C Yan, Zhengyi Jiang

Faculty of Engineering and Information Sciences - Papers: Part A

An improved genetic algorithm is presented for the water consumption of the secondary cooling zone based on the heat transfer model of the off-line bloom caster. This study is to control the existing cooling systems and the steel casting practises in order to produce steel with best possible quality. The fitness function of improved genetic algorithm is founded according to the metallurgical criteria. This algorithm coupled with heat transfer model and metallurgical criteria, added dynamic coding method and self-adapting mutation on the original genetic algorithm can increase water distribution adaptively and improve the process efficiency. The simulation results of T91 …


Comparison Of Oncentra ® Brachy Ipsa And Graphical Optimisation Techniques: A Case Study Of Hdr Brachytherapy Head And Neck And Prostate Plans, Michael Jameson, Lucy Ohanessian, Vikneswary Batumalai, Virendra Patel, Lois C. Holloway Jan 2015

Comparison Of Oncentra ® Brachy Ipsa And Graphical Optimisation Techniques: A Case Study Of Hdr Brachytherapy Head And Neck And Prostate Plans, Michael Jameson, Lucy Ohanessian, Vikneswary Batumalai, Virendra Patel, Lois C. Holloway

Faculty of Engineering and Information Sciences - Papers: Part A

There are a number of different dwell positions and time optimisation options available in the Oncentra® Brachy (Elekta Brachytherapy Solutions, Veenendaal, The Netherlands) brachytherapy treatment planning system. The purpose of this case study was to compare graphical (GRO) and inverse planning by simulated annealing (IPSA) optimisation techniques for interstitial head and neck (HN) and prostate plans considering dosimetry, modelled radiobiology outcome and planning time. Four retrospective brachytherapy patients were chosen for this study, two recurrent HN and two prostatic boosts. Manual GRO and IPSA plans were generated for each patient. Plans were compared using dose-volume histograms (DVH) and dose …


Modelling And Identifying The Parameters Of A Magneto-Rheological Damper With A Force-Lag Phenomenon, Gangrou Peng, Weihua Li, Haiping Du, Huaxia Deng, Gursel Alici Jan 2014

Modelling And Identifying The Parameters Of A Magneto-Rheological Damper With A Force-Lag Phenomenon, Gangrou Peng, Weihua Li, Haiping Du, Huaxia Deng, Gursel Alici

Faculty of Engineering and Information Sciences - Papers: Part A

In this study a model based on the Bouc-Wen-Baber-Noori (BWBN) method was proposed to describe the distorted hysteretic behaviour of a self-constructed magneto-rheological (MR) damper whose mechanical performance was measured with an Instron test machine. The experimental results indicated that the MR damper exhibited a force-lag phenomenon. The parameters of the modified BWBN model were identified with the MATLAB SIMULINK Design and Optimisation toolbox. A comparison between the experimental results and modelling predictions revealed that the proposed model could well present the force-lag phenomenon.


Optimisation Of Size-Controllable Centroidal Voronoi Tessellation For Fem Simulation Of Micro Forming Processes, Liang Luo, Zhengyi Jiang, Haina Lu, Dongbin Wei, Kezhi Linghu, Xianming Zhao, Di Wu Jan 2014

Optimisation Of Size-Controllable Centroidal Voronoi Tessellation For Fem Simulation Of Micro Forming Processes, Liang Luo, Zhengyi Jiang, Haina Lu, Dongbin Wei, Kezhi Linghu, Xianming Zhao, Di Wu

Faculty of Engineering and Information Sciences - Papers: Part A

Voronoi tessellation has been employed to characterise material features in Finite Element Method (FEM) simulation, however, a poor mesh quality of the voronoi tessellations causes problems in explicit dynamic simulation of forming processes. Although centroidal voronoi tessellation can partly improve the mesh quality by homogenisation of voronoi tessellations, small features, such as short edges and small facets, lead to an inferior mesh quality. Further, centroidal voronoi tessellation cannot represent all real micro structures of materials because of the almost equal tessellation shape and size. In this paper, a density function is applied to control the size and distribution of voronoi …


On The Application Of Two-Dimensional Chirplets For Resilient Digital Image Watermarking, Jonathan Blackledge, Oleksandr Iakovenko Jan 2013

On The Application Of Two-Dimensional Chirplets For Resilient Digital Image Watermarking, Jonathan Blackledge, Oleksandr Iakovenko

Conference papers

Chirplets (swept-frequency harmonic signals) find applications in several areas, including real and synthetic aperture radar, (Fresnel) optics and image processing. The robustness of chirplets to extreme (additive) noise make them an ideal choice in the role of embedding patterns for resilient digital signal and image watermarking. In this paper we present a new watermarking technique which is based on embedding two-dimensional chirplet coded binary sequences in digital images. This approach provides a pattern embedded recovery algorithm which is robust to a variety of distortions. However, chirplets have certain parameters that need to be specified, and given a set of target …


Application Of Multiple Objective Particle Swarm Optimisation In The Design Of Damaged Offshore Mooring Systems, Zhuo Wang, Timothy J. Mccarthy, M Neaz Sheikh Jan 2013

Application Of Multiple Objective Particle Swarm Optimisation In The Design Of Damaged Offshore Mooring Systems, Zhuo Wang, Timothy J. Mccarthy, M Neaz Sheikh

Faculty of Engineering and Information Sciences - Papers: Part A

The offshore hydrocarbon industry operates in more hostile environments as more of marginal fields become economically viable. This means that more floating production systems and economical mooring systems will be needed. With this increase in the use of marginal fields goes the need to re-use vessels and moorings. Floating production systems, such as FPSO's, need to survive extreme events and extreme damage conditions. When one mooring line is damaged, the remaining ones must be sufficient to avoid a complete failure and still protect critical components such as the riser. This paper looks into applying an evolutionary optimisation technique, namely multiple …


A New Formulation For The Geometric Layout Optimisation Of Flat Slab Floor Systems, Muhammad N. Hadi, Pezhman Sharafi, Lip H. Teh Jan 2012

A New Formulation For The Geometric Layout Optimisation Of Flat Slab Floor Systems, Muhammad N. Hadi, Pezhman Sharafi, Lip H. Teh

Faculty of Engineering and Information Sciences - Papers: Part A

This paper presents a heuristic approach for the optimum layout design of multi-span flat slab floors in order to optimise the total cost. For this purpose, a heuristic methodology is developed in order to achieve a new objective function for the structural optimisation problem. The proposed objective function has the capability to make use of action effects of the structure as the alternative design variables in place of the commonly used cross-sectional ones. Such a feature provides the method with the ability to be easily employed in large and realistic structural optimisation problems. Furthermore, the proposed formulation, in an iterative …


Self-Shape Optimisation Of Cold-Formed Steel Columns, Timothee Savoyat, Benoit Gilbert, Lip H. Teh Jan 2012

Self-Shape Optimisation Of Cold-Formed Steel Columns, Timothee Savoyat, Benoit Gilbert, Lip H. Teh

Faculty of Engineering and Information Sciences - Papers: Part A

One of the main advantages of cold-formed steel profiles is the great flexibility of cross-sectional shapes, attributable to the manufacturing process allowing achievement of almost any desired cross-section. The cross-sectional shape is the key element in enhancing the strength of coldformed steel profiles as it controls the three fundamental buckling modes: local, distortional (for open profiles) and global. However, research on optimisation of cold-formed steel profiles has been mainly restricted to the conventional C, Z or Σ cross-sectional shapes and seldom new crosssectional shapes have been considered. This report presents the optimisation of cold-formed open columns using the recently developed …


Optimisation Of Power Detection Interrogation Methods For Fibre Bragg Grating Sensors, Graham Wild, Steven Richardson Jan 2012

Optimisation Of Power Detection Interrogation Methods For Fibre Bragg Grating Sensors, Graham Wild, Steven Richardson

Research outputs 2012

We present a method to optimise the performance of power detection interrogation systems for fibre Bragg grating sensors. The performance of the different systems can be optimised in terms of their sensitivity and/or dynamic range.


Train Service Timetabling In Railway Open Markets By Particle Swarm Optimisation, T K. Ho, C W. Tsang, K H. Ip, K S. Kwan Jan 2012

Train Service Timetabling In Railway Open Markets By Particle Swarm Optimisation, T K. Ho, C W. Tsang, K H. Ip, K S. Kwan

SMART Infrastructure Facility - Papers

Railway timetabling is an important process in train service provision as it matches the transportation demand with the infrastructure capacity while customer satisfaction is also considered. It is a multi-objective optimisation problem, in which a feasible solution, rather than the optimal one, is usually taken in practice because of the time constraint. The quality of services may suffer as a result. In a railway open market, timetabling usually involves rounds of negotiations amongst a number of self-interested and independent stakeholders and hence additional objectives and constraints are imposed on the timetabling problem. While the requirements of all stakeholders are taken …


Self-Shape Optimisation Application: Optimisation Of Cold-Formed Steel Columns, Benoit P. Gilbert, Timothee J-M Savoyat, Lip H. Teh Jan 2012

Self-Shape Optimisation Application: Optimisation Of Cold-Formed Steel Columns, Benoit P. Gilbert, Timothee J-M Savoyat, Lip H. Teh

Faculty of Engineering - Papers (Archive)

This paper presents the optimisation of cold-formed steel open columns using the recently developed self-shape optimisation method that aims to discover new profile shapes. The strength of the coldformed steel sections is calculated using the Direct Strength Method, and the rules developed in the present work to automatically determine the local and distortional elastic buckling stresses from the Finite Strip and constrained Finite Strip Methods are discussed. The rules are verified against conventional and optimum sections yielded in this research, and found to accurately predict the elastic buckling stresses. The optimisation method is applied to singly-symmetric (mono-symmetric) cold-formed steel columns, …


Self-Shape Optimisation Of Cold-Formed Steel Closed Profiles Using Genetic Algorithms, Benoit Gilbert, Lip H. Teh, Hong Guan Jan 2011

Self-Shape Optimisation Of Cold-Formed Steel Closed Profiles Using Genetic Algorithms, Benoit Gilbert, Lip H. Teh, Hong Guan

Faculty of Engineering and Information Sciences - Papers: Part A

For economical benefits, optimisation of mass-produced structural steel products is widely researched. The objective is to minimise the quantity of material used without sacrificing the strength and practicality of the structural members. Current research focuses on optimising the dimensions of conventional cross-sectional shapes but rarely considers discovering new optimum shapes. This report introduces the concepts of a new optimisation method which enables the crosssection to self-shape to an optimum by using the evolution and adaptation benefits of Genetic Algorithm. The feasibility and accuracy of the method are verified by implementing it to find optimum thin-walled profiles against simple parameters for …


Discrete Element Modelling: Trouble-Shooting And Optimisation Tool For Chute Design, Andrew P. Grima, Thomas Fraser, David B. Hastie, Peter W. Wypych Jan 2011

Discrete Element Modelling: Trouble-Shooting And Optimisation Tool For Chute Design, Andrew P. Grima, Thomas Fraser, David B. Hastie, Peter W. Wypych

Faculty of Engineering and Information Sciences - Papers: Part A

Conveyor transfer stations play a key role in many industries that handle bulk materials. Transfer stations can be rather sensitive to changes in material properties and can lead to relentless problems regarding reliability, wear, bottlenecking and blockages. Wet and sticky ores are typically difficult to handle materials due to their obnoxious ability to form a cohesive arch, adhere to surfaces and poor flow ability. Mines that are situated in areas with seasonal high rainfalls or that have started to exploit newer and more difficult to mine and handle ores, often from below the water table, experience vast difficulty in reliably …


Maximizing The Life Of A Lithium-Ion Cell By Optimization Of Charging Rates, Saeed Khaleghi Rahimian, Sean Rayman, Ralph E. White Jan 2010

Maximizing The Life Of A Lithium-Ion Cell By Optimization Of Charging Rates, Saeed Khaleghi Rahimian, Sean Rayman, Ralph E. White

Faculty Publications

Using a dynamic optimization method, the optimum charge currents as a function of cycle number during cycling for the lithium-ion cell are obtained. A single particle physics-based model, which includes capacity fade, was applied to simulate the cell performance under low earth-orbit (LEO) cycling conditions. Useful cell life is defined as the number of cycles before the end of discharge voltage drops below 3.0 V or the cell discharge capacity becomes less than 20% of the original discharge capacity. The simulated useful cell life can be increased by ∼29.28% by varying the charge current.


Optimisation Of A Floating Oscillating Water Column Wave Energy Converter, Brad Stappenbelt, Paul Cooper Jan 2010

Optimisation Of A Floating Oscillating Water Column Wave Energy Converter, Brad Stappenbelt, Paul Cooper

Faculty of Engineering - Papers (Archive)

The analysis of floating oscillating water column (OWC) wave energy conversion (WEC) devices involves the coupled dynamics of the water column and the floating structure. In the present study, a mechanical oscillator model was used to examine this relationship for the heave motion of a floating wave energy conversion device. Optimal power take-off damping of the system was determined and the effects on maximum power capture examined. The influence of relative OWC and floating structure natural frequencies on OWC WEC device optimisation was also investigated.


Optimisation Methods In Supply Chain Applications: A Review, Amr Arisha, Waleed Abo Hamad Sep 2009

Optimisation Methods In Supply Chain Applications: A Review, Amr Arisha, Waleed Abo Hamad

Conference papers

The competitiveness and dynamic nature of today’s marketplace is due to rapid advances in information technology, short product life cycles and the continuing trend in global outsourcing. Managing the resulting supply chain networks effectively is a complex and challenging task which is imputable to high level of uncertainty in supply-demand, conflict objectives, vagueness of information, numerous decision variables and constraints. With such level of complexity in the environment, supply chain optimisation has a potential to make a significant contribution to resolve the challenges. In this paper, a literature review – based on more than one hundred peer-reviewed articles – of …


A Particle Swarm Optimisation Approach To Reinforced Concrete Beam Design According To As3600, Timothy J. Mccarthy, Sean Mccluskey Jan 2009

A Particle Swarm Optimisation Approach To Reinforced Concrete Beam Design According To As3600, Timothy J. Mccarthy, Sean Mccluskey

Faculty of Engineering - Papers (Archive)

A program has been developed to utilise the Particle Swarm Optimisation Algorithm for the cost optimum design of reinforced concrete beams. Multiple constraints according to Australian Standard 3600 have been implemented along with costing information. A series of tests where conducted to investigate the effect of different parameters of the particle swarm algorithm and some refinement of these parameters was conducted. The value penalty coefficients had a significant effect on the results, causing non-convergence when very large penalty coefficients where used, and convergence on non-viable results when very small penalty coefficients where used.


Bolt Profile Configuration And Load Transfer Capacity Optimisation, Naj Aziz, Jan Nemcik, Chen Cao, Hossein Jalalifar Jan 2009

Bolt Profile Configuration And Load Transfer Capacity Optimisation, Naj Aziz, Jan Nemcik, Chen Cao, Hossein Jalalifar

Faculty of Engineering and Information Sciences - Papers: Part A

Both bolt profile shape and spacing (rib spacing) have been found to influence the bonding capacity of the grouted rock bolt. The bolt surface profile configuration has greater importance to rock bolting in strata reinforcement in mining than the steel rebar used in civil engineering construction. This is because a rock bolt in mining usually is subjected to greater dynamic loading than the steel rebar in civil engineering construction. The increased bonding capacity of a bolt is important when supported ground is either heavily fractured, faulted or the supported ground is of soft formation, typically that of coal measure rocks. …


A Special-Purpose Architecture For Solving The Breakpoint Median Problem, Jason D. Bakos, Panormitis E. Elenis Dec 2008

A Special-Purpose Architecture For Solving The Breakpoint Median Problem, Jason D. Bakos, Panormitis E. Elenis

Faculty Publications

In this paper, we describe the design for a co-processor for whole-genome phylogenetic reconstruction. Our current design performs a parallelized breakpoint median computation, which is an expensive component of the overall application. When implemented on a field-programmable gate array (FPGA), our hardware breakpoint median achieves a maximum speedup of 1005times over software. When the coprocessor is used to accelerate the entire reconstruction procedure, we achieve a maximum application speedup of 417times. The results in this paper suggest that FPGA-based acceleration is a promising approach for computationally expensive phylogenetic problems, in spite of the fact that the involved algorithms are based …


Fpga Acceleration Of Gene Rearrangement Analysis, Jason D. Bakos Apr 2007

Fpga Acceleration Of Gene Rearrangement Analysis, Jason D. Bakos

Faculty Publications

In this paper we present our work toward FPGA acceleration of phylogenetic reconstruction, a type of analysis that is commonly performed in the fields of systematic biology and comparative genomics. In our initial study, we have targeted a specific application that reconstructs maximum-parsimony (MP) phylogenies for gene-rearrangement data. Like other prevalent applications in computational biology, this application relies on a control-dependent, memory-intensive, and non-arithmetic combinatorial optimization algorithm. To achieve hardware acceleration, we developed an FPGA core design that implements the application's primary bottleneck computation. Because our core is lightweight, we are able to synthesize multiple cores on a single FPGA. …


Dynamic Maximum Power Point Tracking Of Photovoltaic Arrays Using Ripple Correlation Control, Trishan Esram, Jonathan W. Kimball, Philip T. Krein, Patrick L. Chapman, Pallab Midya Sep 2006

Dynamic Maximum Power Point Tracking Of Photovoltaic Arrays Using Ripple Correlation Control, Trishan Esram, Jonathan W. Kimball, Philip T. Krein, Patrick L. Chapman, Pallab Midya

Electrical and Computer Engineering Faculty Research & Creative Works

A dynamically rapid method used for tracking the maximum power point of photovoltaic arrays, known as ripple correlation control, is presented and verified against experiment. The technique takes advantage of the signal ripple, which is automatically present in power converters. The ripple is interpreted as a perturbation from which a gradient ascent optimization can be realized. The technique converges asymptotically at maximum speed to the maximum power point without the benefit of any array parameters or measurements. The technique has simple circuit implementations.


Inter-Layer Distance Optimisation For A Light-Based Flowmeter By Means Of Cfd, Ajit Godbole, Buyung Kosasih, Anton Fuchs Jan 2006

Inter-Layer Distance Optimisation For A Light-Based Flowmeter By Means Of Cfd, Ajit Godbole, Buyung Kosasih, Anton Fuchs

Faculty of Engineering - Papers (Archive)

A non-intrusive method to measure the particle velocities in dilute-phase pneumatic conveying is described. The method is based on correlating signals, which are measured in two flow cross-sections. The cross-correlation function generated provides information about the time it takes for a particle to travel between the measurement planes. Knowing the inter-plane distance and the time delay, the particle velocity can be calculated. The two measurement planes must be an optimum distance apart to ensure the best possible signal resolution and sufficient quality of the cross-correlation: If the distance is too small, the resolution is coarse, while for a too large …


Power Transmission Control Using Distributed Max-Flow, Bruce M. Mcmillin, Austin Armbruster, Mariesa Crow, Michael R. Gosnell Jul 2005

Power Transmission Control Using Distributed Max-Flow, Bruce M. Mcmillin, Austin Armbruster, Mariesa Crow, Michael R. Gosnell

Computer Science Faculty Research & Creative Works

Existing maximum flow algorithms use one processor for all calculations or one processor per vertex in a graph to calculate the maximum possible flow through a graph's vertices. This is not suitable for practical implementation. We extend the max-flow work of Goldberg and Tarjan to a distributed algorithm to calculate maximum flow where the number of processors is less than the number of vertices in a graph. Our algorithm is applied to maximizing electrical flow within a power network where the power grid is modeled as a graph. Error detection measures are included to detect problems in a simulated power …


Spectral Characterization Of Broadband Thz Antennas By Photoconductive Mixing: Toward Optimal Antenna Design, Rajind Mendis, C. Sydlo, J. Sigmund, M Feiginov, P. Meissner, H. L. Hartnagel Jan 2005

Spectral Characterization Of Broadband Thz Antennas By Photoconductive Mixing: Toward Optimal Antenna Design, Rajind Mendis, C. Sydlo, J. Sigmund, M Feiginov, P. Meissner, H. L. Hartnagel

Faculty of Engineering - Papers (Archive)

The spectral characterization of a broadband antenna using a pump-probe photomixing continuous-wave (CW) terahertz (THz) system is presented. The high dynamic range of the system, comparable to or better than that of similar pump-probe systems reported in the literature, provides an accurate means of antenna characterization. The planar antenna exhibits a log-periodic behavior at low frequencies, a bow-tie behavior at high frequencies, and a resonance characteristic in between, well in agreement with the antenna geometry. It is predicted that an improved geometry that extends the log-periodic behavior to higher frequencies would contribute significantly in enhancing the broadband performance of antenna-coupled …