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Full-Text Articles in Engineering

Adaptive Sampling Trust-Region Methods For Derivative-Based And Derivative-Free Simulation Optimization Problems, Sara Shashaani Dec 2016

Adaptive Sampling Trust-Region Methods For Derivative-Based And Derivative-Free Simulation Optimization Problems, Sara Shashaani

Open Access Dissertations

We consider unconstrained optimization problems where only “stochastic” estimates of the objective function are observable as replicates from a Monte Carlo simulation oracle. In the first study we assume that the function gradients are directly observable through the Monte Carlo simulation. We propose ASTRO, which is an adaptive sampling based trust-region optimization method where a stochastic local model is constructed, optimized, and updated iteratively. ASTRO is a derivative-based algorithm and provides almost sure convergence to a first-order critical point with good practical performance. In the second study the Monte Carlo simulation is assumed to provide no direct observations of the …


Modelling The Softening Behaviour During Galvanizing Of Various Steel Grades, Kevin Banks, Rorisang Maubane, Thabang Makwena Oct 2016

Modelling The Softening Behaviour During Galvanizing Of Various Steel Grades, Kevin Banks, Rorisang Maubane, Thabang Makwena

The 8th International Conference on Physical and Numerical Simulation of Materials Processing

No abstract provided.


Thermodynamic Simulation For Solidification Path In Die Casting Alloy Development, Mohamad Rusydi Mohamad Yasin, Dongke Sun, Qingyou Han Oct 2016

Thermodynamic Simulation For Solidification Path In Die Casting Alloy Development, Mohamad Rusydi Mohamad Yasin, Dongke Sun, Qingyou Han

The 8th International Conference on Physical and Numerical Simulation of Materials Processing

No abstract provided.


Simulation For Carbon Nanotube Dispersion And Microstructure Formation In Cnts/Mg Composite Fabricated With Ultrasonic Processing, Yuansheng Yang, Fuze Zhao, Shaozhen Zhu, Xiaohui Feng Oct 2016

Simulation For Carbon Nanotube Dispersion And Microstructure Formation In Cnts/Mg Composite Fabricated With Ultrasonic Processing, Yuansheng Yang, Fuze Zhao, Shaozhen Zhu, Xiaohui Feng

The 8th International Conference on Physical and Numerical Simulation of Materials Processing

No abstract provided.


Modelling The Softening Behaviour During Galvanizing Of Various Steel Grades, Kevin Banks, Rorisang Maubane, Thabang Makwena Oct 2016

Modelling The Softening Behaviour During Galvanizing Of Various Steel Grades, Kevin Banks, Rorisang Maubane, Thabang Makwena

The 8th International Conference on Physical and Numerical Simulation of Materials Processing

No abstract provided.


Temperature Distributions Influencing Lateral Spread In Industrial Hot Rolling, Baohui Tian, Siegfried Kleber, Silvia Zinner, Peter Markiewicz Oct 2016

Temperature Distributions Influencing Lateral Spread In Industrial Hot Rolling, Baohui Tian, Siegfried Kleber, Silvia Zinner, Peter Markiewicz

The 8th International Conference on Physical and Numerical Simulation of Materials Processing

No abstract provided.


The Simulation For Ultrasonic Testing Based On Frequency-Phase Coded Excitation, Jiaying Zhang, Wenlong Tian, Tie Gang, Sen Cong, Zhaoyang Sheng Oct 2016

The Simulation For Ultrasonic Testing Based On Frequency-Phase Coded Excitation, Jiaying Zhang, Wenlong Tian, Tie Gang, Sen Cong, Zhaoyang Sheng

The 8th International Conference on Physical and Numerical Simulation of Materials Processing

No abstract provided.


Study On Growth Model Of Cellular Automata Method In Solidification Simulation, Zhao Guo, Jian-Xin Zhou, Ya-Jun Yin, Chang-Chang Liu Oct 2016

Study On Growth Model Of Cellular Automata Method In Solidification Simulation, Zhao Guo, Jian-Xin Zhou, Ya-Jun Yin, Chang-Chang Liu

The 8th International Conference on Physical and Numerical Simulation of Materials Processing

No abstract provided.


Integration Of Advanced Simulation And Visualization For Material Processing, Chenn Zhou Oct 2016

Integration Of Advanced Simulation And Visualization For Material Processing, Chenn Zhou

The 8th International Conference on Physical and Numerical Simulation of Materials Processing

No abstract provided.


Metamodels Of Residual Stress Buildup For Machining Process Modeling, Stuart B. Mccrorie, Michael Sangid Aug 2016

Metamodels Of Residual Stress Buildup For Machining Process Modeling, Stuart B. Mccrorie, Michael Sangid

The Summer Undergraduate Research Fellowship (SURF) Symposium

In the process of machining materials, stresses, called residual stresses, accumulate in the workpiece being machined that remain after the process is completed. These residual stresses can affect the properties of the material or cause part distortion, and it is important that they be calculated to prevent complications from arising due to the residual stresses. However, these calculations can be incredibly computationally intensive, and thus other methods are needed to predict the residual stresses in materials for quick decision-making during machining. By using metamodels - a method of representing data where few data points exist - we can achieve an …


Investigation Of Digital Pump/Motor Control Strategies, Farid El Breidi Aug 2016

Investigation Of Digital Pump/Motor Control Strategies, Farid El Breidi

Open Access Dissertations

A pump is the heart of fluid power systems, it has a significant impact on the efficiency of many fluid power systems. Motors are the most common rotary actuators in fluid power systems. State-of-the-art pump/motor units can achieve efficiencies higher than 90% when operating at maximum displacement; however, as the displacement drops, the efficiency of these units drops to below 50%. A new digital pump/motor design aims at increasing these efficiencies by utilizing two electrically controlled high speed on/off valves per displacement chamber; these valves provide the ability to achieve variable displacement and allow freedom in choosing operating strategies. Such …