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Full-Text Articles in Engineering
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 …
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.
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. …
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.
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 …
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 …
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 …
Optimization Of The Sequential Polymerization Synthesis Method For Polypyrrole Films, Danial Sangian, Wen Zheng, Geoffrey M. Spinks
Optimization Of The Sequential Polymerization Synthesis Method For Polypyrrole Films, Danial Sangian, Wen Zheng, Geoffrey M. Spinks
Australian Institute for Innovative Materials - Papers
Polypyrrole (PPy) is widely used as an electroactive material and is most often synthesized using electrochemical polymerization. Recently, a new electropolymerization method [1] was introduced that involved preparing the PPy as a sequential series of electrodeposited layers with solvent washing in between each deposited layer. This method enabled high quality PPy free-standing films to be prepared in a relatively short time. The purpose of the present study was to investigate the effect of the polymerization current density on the mechanical and electrical properties of the sequentially polymerized (SEP) PPy films. It was found that a low current density (0.1 mA/cm2) …