Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 28 of 28
Full-Text Articles in Engineering
Dynamic Exergy Analysis For The Thermal Storage Optimization Of The Building Envelope, Valentina Bonetti, Georgios Kokogiannakis
Dynamic Exergy Analysis For The Thermal Storage Optimization Of The Building Envelope, Valentina Bonetti, Georgios Kokogiannakis
Faculty of Engineering and Information Sciences - Papers: Part A
As a measure of energy "quality", exergy is meaningful for comparing the potential for thermal storage. Systems containing the same amount of energy could have considerably different capabilities in matching a demand profile, and exergy measures this difference. Exergy stored in the envelope of buildings is central in sustainability because the environment could be an unlimited source of energy if its interaction with the envelope is optimised for maintaining the indoor conditions within comfort ranges. Since the occurring phenomena are highly fluctuating, a dynamic exergy analysis is required; however, dynamic exergy modelling is complex and has not hitherto been implemented …
Model-Based Optimization Of Ground Source Heat Pump Systems, Zhenjun Ma, Lei Xia
Model-Based Optimization Of Ground Source Heat Pump Systems, Zhenjun Ma, Lei Xia
Faculty of Engineering and Information Sciences - Papers: Part A
This paper presents the development of an optimization strategy for ground source heat pump (GSHP) systems equipped with variable speed pumps in the ground loop system. The optimization problem is formulated using a model-based approach, in which the component models are used to estimate the system performance under various trial settings and an exhaustive search method is used to identify the optimal settings under the search ranges defined. The variable optimized is the outlet water temperature from the ground heat exchangers, which can be used as a set-point to control the operation of the variable speed pumps in the ground …
Optimization Of A Ceiling Ventilation System With Integrated Photovoltaic Thermal Collectors And Phase Change Materials, Zhenjun Ma, Wenye Lin, Mohammed I. Sohel
Optimization Of A Ceiling Ventilation System With Integrated Photovoltaic Thermal Collectors And Phase Change Materials, Zhenjun Ma, Wenye Lin, Mohammed I. Sohel
Faculty of Engineering and Information Sciences - Papers: Part A
This paper presents the performance evaluation and design optimization of a ceiling ventilation system with integrated solar photovoltaic thermal (PVT) collectors and phase change materials (PCMs) by using a hybrid Particle Swarm Optimization and Hooke-Jeeves Pattern search (PSO-HJ) algorithm. In this novel ceiling ventilation system, the PVT collectors are used to generate electricity and provide the low-grade heating energy for buildings by using the winter daytime solar radiation, while the PCM is integrated into the building ceiling as part of the ceiling insulation and at the same time, as a centralized thermal energy storage unit to temporally store the low-grade …
Size Optimization Of A Magnetic System For Drug Delivery With Capsule Robots, Fredy Munoz, Gursel Alici, Weihua Li, Metin Sitti
Size Optimization Of A Magnetic System For Drug Delivery With Capsule Robots, Fredy Munoz, Gursel Alici, Weihua Li, Metin Sitti
Faculty of Engineering and Information Sciences - Papers: Part A
In this paper, we present a methodology for the size optimization of an external magnetic system made of arc-shaped permanent magnets (ASMs). This magnetic system is able to remotely actuate a drug-release module embedded in a prototype of a capsule robot. The optimization of the magnetic system is carried out by using an accurate analytical model that is valid for any arbitrary dimensions of the ASMs. By using this analytical model, we perform parametric studies and conduct a statistical analysis [analysis of variance (ANOVA)] to investigate efficient ways to distribute the volume of the ASMs so that the dimensions and …
Development And Optimization Of An Innovative Hvac System With Integrated Pvt And Pcm Thermal Storage For A Net-Zero Energy Retrofitted House, Massimo Fiorentini, Paul Cooper, Zhenjun Ma
Development And Optimization Of An Innovative Hvac System With Integrated Pvt And Pcm Thermal Storage For A Net-Zero Energy Retrofitted House, Massimo Fiorentini, Paul Cooper, Zhenjun Ma
Faculty of Engineering and Information Sciences - Papers: Part A
This paper describes a novel solar-assisted HVAC system developed for the Team UOW 'Illawarra Flame' Solar Decathlon house, the winner of the Solar Decathlon China 2013 competition. This HVAC system consists of an air-based photovoltaic-thermal (PVT) collector and a phase change material (PCM) thermal storage unit integrated with a reverse cycle heat pump, in a ducted system. The system was designed for operation during both winter and summer using daytime solar radiation and night-time sky radiative cooling, respectively. The PVT collector heats or cools fresh air from ambient and thereby provides heating or cooling either directly to the indoor space, …
Optimization Of The Number Of Rays In Interpolation For Light Field Based Free Viewpoint Systems, Hooman Shidanshidi, Farzad Safaei, Wanqing Li
Optimization Of The Number Of Rays In Interpolation For Light Field Based Free Viewpoint Systems, Hooman Shidanshidi, Farzad Safaei, Wanqing Li
Faculty of Engineering and Information Sciences - Papers: Part A
Light field (LF) rendering is widely used in free viewpoint video systems (FVV). Different methods have been proposed to employ depth maps to improve the rendering quality. However, estimation of depth is often error-prone. In this paper, a new method based on the concept of effective sampling density (ESD) is proposed for evaluating the depth-based LF rendering algorithms at different levels of errors in the depth estimation. In addition, for a given rendering quality, we provide an estimation of number of rays required in the interpolation algorithm to compensate for the adverse effect caused by errors in depth maps. The …
Direct Power Control Of Dfig Based Wind Turbine Based On Wind Speed Estimation And Particle Swarm Optimization, Mehrdad Tarafdar Hagh, S Roozbehani, F Najaty, S Ghaemi, Yingjie Tan, Kashem M. Muttaqi
Direct Power Control Of Dfig Based Wind Turbine Based On Wind Speed Estimation And Particle Swarm Optimization, Mehrdad Tarafdar Hagh, S Roozbehani, F Najaty, S Ghaemi, Yingjie Tan, Kashem M. Muttaqi
Faculty of Engineering and Information Sciences - Papers: Part A
This paper presents a direct power control (DPC) design of a grid connected doubly fed induction generator (DFIG) based wind turbine system in order to track maximum absorbable power in different wind speeds. A generalized regression neural network (GRNN) is used to estimate wind speed and thereby the maximum absorbable power is determined online as a function of wind speed. Finally the proposed DPC strategy employs a nonlinear robust sliding mode control (SMC) scheme to calculate the required rotor control voltage directly. The concept of sliding mode control is incorporated into particle swarm optimization (PSO) to determine inertial weights. The …
Stochastic Modeling And Optimization Of Multi-Plant Capacity Planning Problem, Anoop Verma, Nagesh Shukla, S.K Tyagi, Nishikant Mishra
Stochastic Modeling And Optimization Of Multi-Plant Capacity Planning Problem, Anoop Verma, Nagesh Shukla, S.K Tyagi, Nishikant Mishra
Faculty of Engineering and Information Sciences - Papers: Part A
n this paper the problem of capacity planning under risk from demand and price/cost uncertainty of the finished products is addressed. The deterministic model is extended into a two-stage stochastic model with fixed recourse by means of various expected levels of demand as random. A recourse penalty is also included in the objective for both shortage and surplus in the finished products. The model is analyzed to quantify the risk using Markowitz mean-variance model.
A Structure Optimization Algorithm Of Neural Networks For Large-Scale Data Sets, Jie Yang, Jun Ma, Matthew J. Berryman, Pascal Perez
A Structure Optimization Algorithm Of Neural Networks For Large-Scale Data Sets, Jie Yang, Jun Ma, Matthew J. Berryman, Pascal Perez
Faculty of Engineering and Information Sciences - Papers: Part A
Over the past several decades, neural networks have evolved into powerful computation systems, which are able to learn complex nonlinear input-output relationship from data. However, the structure optimization problem of neural network is a big challenge for processing huge-volumed, diversified and uncertain data. This paper focuses on this problem and introduces a network pruning algorithm based on sparse representation, termed SRP. The proposed approach starts with a large network, then selects important hidden neurons from the original structure using a forward selection criterion that minimizes the residual output error. Furthermore, the presented algorithm has no constraints on the network type. …
Global Optimization Method For Robust Pricing Of Transportation Networks Under Uncertain Demand, Shuaian Wang, Lauren Gardner, S.Travis Waller
Global Optimization Method For Robust Pricing Of Transportation Networks Under Uncertain Demand, Shuaian Wang, Lauren Gardner, S.Travis Waller
Faculty of Engineering and Information Sciences - Papers: Part A
We extend the existing toll pricing studies with fixed demand to stochastic demand. A new and practical second-best pricing problem with uncertain demand is proposed and formulated as a stochastic mathematical program with equilibrium constraints. In view of the problem structure, we develop a tailored global optimization algorithm. This algorithm incorporates a sample average approximation scheme, a relaxation-strengthening method, and a linearization approach. The proposed global optimization algorithm is applied to three networks: a two-link network, a seven-eleven network and the Sioux-Falls network. The results demonstrate that using a single fixed estimation of future demand may overestimate the future system …
Shape Optimization Of Thin-Walled Steel Sections Using Graph Theory And Aco Algorithm, Pezhman Sharafi, Lip H. Teh, Muhammad N. S Hadi
Shape Optimization Of Thin-Walled Steel Sections Using Graph Theory And Aco Algorithm, Pezhman Sharafi, Lip H. Teh, Muhammad N. S Hadi
Faculty of Engineering and Information Sciences - Papers: Part A
This paper presents an intuitive procedure for the shape and sizing optimizations of open and closed thin-walled steel sections using the graph theory. The goal is to find shapes of optimum mass and strength (bi-objectives). The shape optimization of open sections is treated as a multi-objective all-pairs shortest path problem, while that of closed sections is treated as a multi-objective minimum mean cycle problem. The sizing optimization of a predetermined shape is treated as a multi-objective single-pair shortest path problem. Multi-colony ant algorithms are formulated for solving the optimization problems. The verification and numerical examples involving the shape optimizations of …
Distribution Expansion Planning Considering Reliability And Security Of Energy Using Modified Pso (Particle Swarm Optimization) Algorithm, Jamshid Aghaei, Kashem M. Muttaqi, Ali Azizivahed, Mohsen Gitizadeh
Distribution Expansion Planning Considering Reliability And Security Of Energy Using Modified Pso (Particle Swarm Optimization) Algorithm, Jamshid Aghaei, Kashem M. Muttaqi, Ali Azizivahed, Mohsen Gitizadeh
Faculty of Engineering and Information Sciences - Papers: Part A
Distribution feeders and substations need to provide additional capacity to serve the growing electrical demand of customers without compromising the reliability of the electrical networks. Also, more control devices, such as DG (Distributed Generation) units are being integrated into distribution feeders. Distribution networks were not planned to host these intermittent generation units before construction of the systems. Therefore, additional distribution facilities are needed to be planned and prepared for the future growth of the electrical demand as well as the increase of network hosting capacity by DG units. This paper presents a multiobjective optimization algorithm for the MDEP (Multi-Stage Distribution …
Geometric Design Optimization For Dynamic Response Problem Of Continuous Reinforced Concrete Beams, Pezhman Sharafi, Muhammad Hadi, Lip H. Teh
Geometric Design Optimization For Dynamic Response Problem Of Continuous Reinforced Concrete Beams, Pezhman Sharafi, Muhammad Hadi, Lip H. Teh
Faculty of Engineering and Information Sciences - Papers: Part A
This paper presents a computer-aided design method for conceptual geometric layout optimization of multispan RC beams for any type of dynamic responses. A key feature of the paper is the development of a new cost-optimization method for geometric layout problems that take both cost parameters and dynamic responses into account to achieve an optimum design along with acceptable dynamic performance of RC beams. This method takes advantage of employing a new optimization formulation that considerably simplifies the preliminary layout design computations. It focuses on minimizing the structural cost subject to constraints on eigenfrequencies, modal shapes, and the static and dynamic …
Optimization And Application Of Process Parameters In An Az61 Alloy Twin-Roll Strip Casting, Jintao Li, Guangming Xu, Hailiang Yu, Lihong Su, Guanyu Deng, Cheng Lu, Lizi He, Huijun Li
Optimization And Application Of Process Parameters In An Az61 Alloy Twin-Roll Strip Casting, Jintao Li, Guangming Xu, Hailiang Yu, Lihong Su, Guanyu Deng, Cheng Lu, Lizi He, Huijun Li
Faculty of Engineering and Information Sciences - Papers: Part A
Twin-roll strip casting is a concerned technology for economically producing magnesium alloys sheets. In this paper, numerical simulation of the twin-roll strip casting of an AZ61 magnesium alloy was carried out and the optimal process parameters were obtained. Then, under the conditions obtained through simulation, AZ61 strips of good surface quality were successfully manufactured. The microstructure of the alloy by twin-rolled strip casting is obvious refined compared with that by conventional casting.
Control Of Conducting Polymer Actuators Without Physical Feedback: Simulated Feedback Control Approach With Particle Swarm Optimization, Xingcan Xiang, Rahim Mutlu, Gursel Alici, Weihua Li
Control Of Conducting Polymer Actuators Without Physical Feedback: Simulated Feedback Control Approach With Particle Swarm Optimization, Xingcan Xiang, Rahim Mutlu, Gursel Alici, Weihua Li
Faculty of Engineering and Information Sciences - Papers: Part A
Conducting polymer actuators have shown significant potential in articulating micro instruments, manipulation devices, and robotics. However, implementing a feedback control strategy to enhance their positioning ability and accuracy in any application requires a feedback sensor, which is extremely large in size compared to the size of the actuators. Therefore, this paper proposes a new sensorless control scheme without the use of a position feedback sensor. With the help of the system identification technique and particle swarm optimization, the control scheme, which we call the simulated feedback control system, showed a satisfactory command tracking performance for the conducting polymer actuator's step …
Light Reflection Is Nonlinear Optimization, Jiakun Liu
Light Reflection Is Nonlinear Optimization, Jiakun Liu
Faculty of Engineering and Information Sciences - Papers: Part A
In this paper, we show that the near field reflector problem is a nonlinear optimization problem. From the corresponding functional and constraint function, we derive the Monge-Ampère type equation for such a problem.
Synthesis And Optimization Of Pedot:Pss Based Ink For Printing Nanoarrays Using Dip-Pen Nanolithography, Michal Wagner, Cathal O'Connell, David G. Harman, Ryan Sullivan, Ari Ivaska, Michael J. Higgins, Gordon G. Wallace
Synthesis And Optimization Of Pedot:Pss Based Ink For Printing Nanoarrays Using Dip-Pen Nanolithography, Michal Wagner, Cathal O'Connell, David G. Harman, Ryan Sullivan, Ari Ivaska, Michael J. Higgins, Gordon G. Wallace
Faculty of Engineering and Information Sciences - Papers: Part A
Due to the current interest in organic printable electronics, Dip-Pen Nanolithography (DPN) is increasingly being explored as a method to pattern electroactive materials such as conducting polymers (CPs) on the micro- and nanoscale. In general, printing process depends strongly on the ink-substrate properties and fundamental forces required to drive and stabilize the ink transfer to the substrate. Controlling these parameters is especially difficult when operating under the nanometer confinements of the DPN probe. For the printing of CPs, one step towards addressing these challenges is rational ink design, as the use of existing commercial-based inks may not be suitable for …
Sizing Optimization Of Trapezoidal Corrugated Roof Sheeting, Supporting Solar Panels, Under Wind Loading, P Sharafi, Lip H. Teh, Muhammad N. S Hadi
Sizing Optimization Of Trapezoidal Corrugated Roof Sheeting, Supporting Solar Panels, Under Wind Loading, P Sharafi, Lip H. Teh, Muhammad N. S Hadi
Faculty of Engineering and Information Sciences - Papers: Part A
The dimensions of trapezoidal roof sheeting supporting solar panels are optimized so that a minimum amount of steel is required for a specific range of wind loads. Sheets of different grades and different thicknesses along with different ranges of wind speeds are considered. In order to simulate the behavior of the corrugated sheets analysis is carried out for two limit states: strength and serviceability. For both limit states, the objective is to minimize the weight per unit area of the panels. First, optimum cross-section is obtained to meet the strength conditions. Then the deflection is controlled for serviceability. The optimum …
Advances In Whole Abdominal Irradiation: What Protons, Vmat, And Imrt Using Multicriteria Optimization Can Offer, N Rochet, E Batin, N Depauw, K Jee, H M. Kooy, F H. Khan, P J. Paetzold, A H. Russell, T R. Bortfeld, D L. Craft
Advances In Whole Abdominal Irradiation: What Protons, Vmat, And Imrt Using Multicriteria Optimization Can Offer, N Rochet, E Batin, N Depauw, K Jee, H M. Kooy, F H. Khan, P J. Paetzold, A H. Russell, T R. Bortfeld, D L. Craft
Faculty of Engineering and Information Sciences - Papers: Part A
Abtract of paper presented 55th Annual Meeting of the American Society for Radiation Oncology 2013.
A Methodology For Cost Optimization Of The Layout Design Of Multi-Span Reinforced Concrete Beams, Pezhman Sharafi, Muhammad Hadi, Lip H. Teh
A Methodology For Cost Optimization Of The Layout Design Of Multi-Span Reinforced Concrete Beams, Pezhman Sharafi, Muhammad Hadi, Lip H. Teh
Faculty of Engineering and Information Sciences - Papers: Part A
This paper presents a description of a new methodology for the optimum preliminary layout design of reinforced concrete multi-span beams considering the relevant cost elements. First, a new objective function is presented, as an alternative to traditional cost functions for reinforced concrete beams. The ability of being easily employed in layout optimization problems, gives the new cost function a distinct advantage over its alternatives. Examples are included to illustrate the performance of the new methodology.
Design Optimization And Comparative Analysis Of Silicon-Nanowire-Based Couplers, Hongqiang Li, Xiaye Dong, Enbang Li, Zhihui Liu, Yaoting Bai
Design Optimization And Comparative Analysis Of Silicon-Nanowire-Based Couplers, Hongqiang Li, Xiaye Dong, Enbang Li, Zhihui Liu, Yaoting Bai
Faculty of Engineering and Information Sciences - Papers: Part A
Three kinds of highly compact 2 x 2 couplers based on silicon nanowire are designed and optimized for the array waveguide grating (AWG) demodulation integration microsystem in this paper. These couplers are directional (X) coupler, cross gap coupler (CGC), and multimode interface (MMI) coupler. The couplers are simulated using the beam propagation method. The distance between the input/output waveguides is set to 10 μm considering the test of a single device in the following work. The total footprint of X coupler is 10 μmx 300 μm. The length of parallel film waveguide is 1 μm. After optimization, the minimum excess …
Multifactor Optimization Of A Fuzzy-Pid Controller Using Genetic Algorithm, Xiaofeng He, Wei Chen, Bihai Zhu, Zhengyi Jiang, Christopher David Cook
Multifactor Optimization Of A Fuzzy-Pid Controller Using Genetic Algorithm, Xiaofeng He, Wei Chen, Bihai Zhu, Zhengyi Jiang, Christopher David Cook
Faculty of Engineering and Information Sciences - Papers: Part A
The design of a Fuzzy-PID controller involves setting the fuzzy rules, membership functions and its associated scaling factors. How to obtain a better control result and how these scaling factors affect the controller's performance are still a challenge. In this paper, the automatic position control system of a Hille 100 experimental rolling mill was used as a research testbed. Based on the mathematical control model of the rolling mill, a Fuzzy-PID controller was developed, and the process of implementing global optimization considering all these factors simultaneously by using genetic algorithm is introduced in detail. Through simulation, the performance of the …
Optimization Of Welding Parameters For Repairing Nial Bronze Components, Huijun Li, Daniel Grudgings, Nathan P. Larkin, John Norrish, Mark Callaghan, Lenka Kuzmikova
Optimization Of Welding Parameters For Repairing Nial Bronze Components, Huijun Li, Daniel Grudgings, Nathan P. Larkin, John Norrish, Mark Callaghan, Lenka Kuzmikova
Faculty of Engineering and Information Sciences - Papers: Part A
The objective of this study is to determine an optimal welding procedure that can be implemented to repair damaged Nickel Aluminium Bronze (NAB) components. NAB is commonly used in marine applications where components are subject to a constant corrosive environment and high stresses. Research into ideal NAB microstructure for a marine application, was performed in order to gain a baseline for experimental analysis of potential welding procedures. The results indicated that the welding repair can be performed with a wide range of heat input. The effect of post-weld heat treatment (PWHT) on the microstructure and mechanical properties in the heat …
Voltage Security Constrained Reactive Power Optimization Incorporating Wind Generation, L G. Meegahapola, E Vittal, A Keane, D Flynn
Voltage Security Constrained Reactive Power Optimization Incorporating Wind Generation, L G. Meegahapola, E Vittal, A Keane, D Flynn
Faculty of Engineering and Information Sciences - Papers: Part A
This paper presents a comparative analysis between conventional optimal power flow (OPF) and voltage constrained OPF strategies with wind generation. The study has been performed using the New England 39 bus system with 12 doublyfed induction generator (DFIG) based wind farms installed across the network. A voltage security assessment is carried out to determine the critical wind farms for voltage stability enhancement. The power losses and individual wind farm reactive power generation have been compared with and without voltage stability constraints imposed on the OPF simulation. It is shown that voltage constrained OPF leads to much greater active power losses …
Delta Extraction Optimization For View Maintenance In A Limited Collaborative Environment, Zheng Lu, Haijun Liu, Peter Hyland
Delta Extraction Optimization For View Maintenance In A Limited Collaborative Environment, Zheng Lu, Haijun Liu, Peter Hyland
Faculty of Engineering and Information Sciences - Papers: Part A
This work considers maintaining materialized view in a distributed environment where the collaboration from highly autonomous operational database management systems is limited to granting read only access on a set of selected relational tables. In addition, due to possibly large volumes of remote source data involved in the view maintenance process, and consequently enormous overhead associated with data transfer, efficiency issues must been taken into the consideration. This proposal is based on the observation that usually, there is a large amount of static data in relational tables. It is proposed to use some statistical techniques at data warehouse system to …
A Λ-Cut And Goal-Programming-Based Algorithm For Fuzzy-Linear Multiple-Objective Bilevel Optimization, Ya Gao, Guangquan Zhang, Jun Ma, Jie Lu
A Λ-Cut And Goal-Programming-Based Algorithm For Fuzzy-Linear Multiple-Objective Bilevel Optimization, Ya Gao, Guangquan Zhang, Jun Ma, Jie Lu
Faculty of Engineering and Information Sciences - Papers: Part A
Bilevel-programming techniques are developed to handle decentralized problems with two-level decision makers, which are leaders and followers, who may have more than one objective to achieve. This paper proposes a λ-cut and goal-programming-based algorithm to solve fuzzy-linear multiple-objective bilevel (FLMOB) decision problems. First, based on the definition of a distance measure between two fuzzy vectors using λ-cut, a fuzzy-linear bilevel goal (FLBG) model is formatted, and related theorems are proved. Then, using a λ-cut for fuzzy coefficients and a goal-programming strategy for multiple objectives, a λ-cut and goal-programming-based algorithm to solve FLMOB decision problems is presented. A case study for …
Compiler Optimization And Ordering Effects On Vliw Code Compression, Montserrat Ros, Peter Sutton
Compiler Optimization And Ordering Effects On Vliw Code Compression, Montserrat Ros, Peter Sutton
Faculty of Engineering and Information Sciences - Papers: Part A
Code size has always been an important issue for all embedded applications as well as larger systems. Code compression techniques have been devised as a way of battling bloated code; however, the impact of VLIW compiler methods and outputs on these compression schemes has not been thoroughly investigated. This paper describes the application of single- and multipleinstruction dictionary methods for code compression to decrease overall code size for the TI TMS320C6xxx DSP family. The compression scheme is applied to benchmarks taken from the Mediabench benchmark suite built with differing compiler optimization parameters. In the single instruction encoding scheme, it was …
Optimization Of Soliton Amplitude In Dispersion-Decreasing Nonlinear Optical Fibres, Ken I M Mckinnon, Noel Smyth, Annette L. Worthy
Optimization Of Soliton Amplitude In Dispersion-Decreasing Nonlinear Optical Fibres, Ken I M Mckinnon, Noel Smyth, Annette L. Worthy
Faculty of Engineering and Information Sciences - Papers: Part A
The compression of a cw into a periodic train of noninteracting solitons by a dispersion-decreasing fiber is investigated with a variational method. To model the evolution from the cw to the soliton train, an elliptic-function-based expression is used as the trial function in the averaged Lagrangian. Both a continuous dispersion variation and a step dispersion variation in the fiber are considered. By use of an optimization method based on the approximate variational equations, the optimal dispersion profile required for achieving maximum pulse compression in a fixed length of fiber is determined. The solutions of the approximate equations are compared with …