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Articles 1 - 13 of 13
Full-Text Articles in Engineering
Reliability-Based Optimization Of Fiber-Reinforced Polymer Composite Bridge Deck Panels, Michel D. Thompson, Christopher D. Eamon, Masoud Rais-Rohani
Reliability-Based Optimization Of Fiber-Reinforced Polymer Composite Bridge Deck Panels, Michel D. Thompson, Christopher D. Eamon, Masoud Rais-Rohani
Civil and Environmental Engineering Faculty Research Publications
A reliability-based optimization (RBO) procedure is developed and applied to minimize the weight of eight fiber-reinforced polymer composite bridge deck panel configurations. The method utilizes interlinked finite element, optimization, and reliability analysis procedures to solve the weight minimization problem with a deterministic strength constraint and two probabilistic deflection constraints. Panels are composed of an upper face plate, lower face plate, and a grid of interior stiffeners. Different panel depths and stiffener layouts are considered. Sensitivity analyses are conducted to identify significant design and random variables. Optimization design variables are panel component ply thicknesses while random variables include load and material …
Design And Fabrication Of Rotationally Tristable Compliant Mechanisms, Tyler M. Pendleton
Design And Fabrication Of Rotationally Tristable Compliant Mechanisms, Tyler M. Pendleton
Theses and Dissertations
The purpose of this research is to develop the tools necessary to create tristable compliant mechanisms; the work presents the creation of models and concepts for design and a demonstration of the feasibility of the designs through the fabrication of tristable compliant mechanism prototypes on the macro scale. Prior methods to achieve tristable mechanisms rely on detents, friction, or power input; disadvantages to these methods include a high number of parts, the necessity for lubrication, and wear. A compliant tristable mechanism accomplishes tristability through strain energy storage. These mechanisms would be preferable because of increased performance and cost savings due …
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
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.
A Damping Constant Limitation Design Of Power System Stabilizer Using Hybrid Differential Evolution, Yung-Sung Chuang, Chi-Jui Wu
A Damping Constant Limitation Design Of Power System Stabilizer Using Hybrid Differential Evolution, Yung-Sung Chuang, Chi-Jui Wu
Journal of Marine Science and Technology
This paper is used to investigate a novel design of lead-lag type power system stabilizers for a multi-machine power system. In the design procedures, the minimum damping constants requirements of all of electromechanical modes can be designated and several typical operating conditions can be considered at the same time. The hybrid differential evolution (HDE) method is used to tune the parameters of power system stabilizers. In the design procedures, a region in the left half complex plane bounded by a line with a given negative real value is given. Thus, at the final step of the HDE, all of electromechanical …
Multiobjective Plan Selection Optimization For Traffic Responsive Control, Montasir M. Abbas, Anuj Sharma
Multiobjective Plan Selection Optimization For Traffic Responsive Control, Montasir M. Abbas, Anuj Sharma
Department of Civil and Environmental Engineering: Faculty Publications
Optimal coordination of traffic signals requires proper activation of timing plans to match current traffic conditions. One of the greatest challenges in configuring a traffic responsive plan selection control mode is how to select only n number of timing plans (restricted by traffic controller memory limitations) to address possibly all traffic conditions/states that can be encountered in the field, for a specific site, but most importantly, how to associate each of these traffic conditions to one of the n timing plans stored in the traffic controller. This paper uses a multiobjective non-dominated sorting genetic algorithm to (1) select the best …
Post Register Allocation Spill Code Optimization, Christopher Lupo, Kent Wilken
Post Register Allocation Spill Code Optimization, Christopher Lupo, Kent Wilken
Computer Science and Software Engineering
A highly optimized register allocator should provide an efficient placement of save/restore code for procedures that contain calls. This paper presents a new approach to placing callee-saved save and restore instructions that generalizes Chow's shrink-wrapping technique (Chow 1988). An efficient, profile-guided, hierarchical spill code placement algorithm is used to analyze the structure of a procedure to calculate the minimum dynamic execution count locations to place callee-saved save and restore code. The algorithm is implemented in the Gnu Compiler Collection and has been tested on the SPEC CPU2000 Integer Benchmark suite. Results show that the technique reduces the number of dynamic …
Doppler-Only Multistatic Radar, Dustin G. Mixon
Doppler-Only Multistatic Radar, Dustin G. Mixon
Theses and Dissertations
In order to estimate the position and velocity of a target, most multistatic radar systems require multiple independent target measurements, such as angle-of-arrival, time-of-arrival, and Doppler information. Though inexpensive and reliable, Doppler-only systems have not been widely implemented due to the inherent nonlinear problem of determining a target’s position and velocity from their measurements. We solve this problem. In particular, we first establish the lack of observability in the Doppler-only bistatic system, thereby demonstrating the need for multiple transmitters and/or receivers. Next, for a multistatic system with a sufficient number of transmitter-receiver pairs, we invoke classical optimization techniques, such as …
Blind Source Separation Based On Time-Domain Optimization Of A Frequency-Domain Independence Criterion, Tiemin Mei, Jiangtao Xi, Fuliang Yin, A. Mertins, Jose F. Chicharo
Blind Source Separation Based On Time-Domain Optimization Of A Frequency-Domain Independence Criterion, Tiemin Mei, Jiangtao Xi, Fuliang Yin, A. Mertins, Jose F. Chicharo
Faculty of Engineering - Papers (Archive)
A new technique for the blind separation of convolutive mixtures is proposed in this paper. Inspired by the works of Amari, Sabala , and Rahbar, we firstly start from the application of Kullback-Leibler divergence in frequency domain, and then we integrate Kullback-Leibler divergence over the whole frequency range of interest to yield a new objective function which turns out to be time-domain variable dependent. In other words, the objective function is derived in frequency domain which can be optimized with respect to time domain variables. The proposed technique has the advantages of frequency domain approaches and is suitable for very …
Design Optimization Of Solid Rocket Motor Grains For Internal Ballistic Performance, Roger Hainline
Design Optimization Of Solid Rocket Motor Grains For Internal Ballistic Performance, Roger Hainline
Electronic Theses and Dissertations
The work presented in this thesis deals with the application of optimization tools to the design of solid rocket motor grains per internal ballistic requirements. Research concentrated on the development of an optimization strategy capable of efficiently and consistently optimizing virtually an unlimited range of radial burning solid rocket motor grain geometries. Optimization tools were applied to the design process of solid rocket motor grains through an optimization framework developed to interface optimization tools with the solid rocket motor design system. This was done within a programming architecture common to the grain design system, AML. This commonality in conjunction with …
An Optimal Dynamic Inversion Approach For Controlling A Class Of One-Dimensional Nonlinear Distributed Parameter Systems, Radhakant Padhi, S. N. Balakrishnan
An Optimal Dynamic Inversion Approach For Controlling A Class Of One-Dimensional Nonlinear Distributed Parameter Systems, Radhakant Padhi, S. N. Balakrishnan
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Combining the principles of dynamic inversion and optimization theory, a new approach is presented for stable control of a class of one-dimensional nonlinear distributed parameter systems, assuming the availability a continuous actuator in the spatial domain. Unlike the existing approximate-then-design and design-then-approximate techniques, here there is no need of any approximation either of the system dynamics or of the resulting controller. Rather, the control synthesis approach is fairly straight-forward and simple. The controller formulation has more elegance because we can prove the convergence of the controller to its steady state value. To demonstrate the potential of the proposed technique, a …
A Comparison Of Agent-Based Optimization Approaches Applied To The Weapons To Targets Assignment Planning Problem, Hitesh Deepak Soneji
A Comparison Of Agent-Based Optimization Approaches Applied To The Weapons To Targets Assignment Planning Problem, Hitesh Deepak Soneji
Browse all Theses and Dissertations
Real-world complex optimization problems are difficult to solve. Agent-based optimization approaches have proved useful in solving a wide variety of problems including optimization problems. Agent-based techniques can be used in military planning for solving allocation problems such as the weapons to targets assignment problem. Classical methods like linear programming (LP) have been used for solving weapons to targets assignment problems. LP approaches provide optimal solutions quickly, but in real-time planning when there are minor changes to input, LP exhibits widely varied solutions. This can be a problem in practice. This research study considers two agent-based optimization approaches, the Stable Marriage …
Robust Shape Design Techniques For Steady-State Metal Forming Processes, Jalaja Repalle
Robust Shape Design Techniques For Steady-State Metal Forming Processes, Jalaja Repalle
Browse all Theses and Dissertations
Metal forming is a process that transforms a simple shape of a workpiece into a predetermined complex shape through the application of compressive/tensile forces exerted by dies. In the design of a forming process, the only factors that are known are the final component shape and the material with which it is to be made. Then the engineer has to design a process to make defect-free product, subject to limitations of shape, material properties, cost, time, and other such factors. The design cycle can be enhanced if performance sensitivity information is available that could be used with any commercially available …
Topology Optimization Of Engine Exhaust-Washed Structures, Mark A. Haney
Topology Optimization Of Engine Exhaust-Washed Structures, Mark A. Haney
Browse all Theses and Dissertations
Aircraft structure subjected to elevated temperature and acoustic loading present a challenging design environment. Thermal stress in a structural component has typically been alleviated by allowing thermal expansion. However, very little work has been done which directly addresses the situation where such a prescription is not possible. When a structural component has failed due to thermally-induced tensile stresses, the answer to the question of how best to stiffen the structure is far from trivial. In this work, we demonstrate that conventional stiffening techniques, for example, those which add material to the thickness of a failing panel, may actually increase the …