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Full-Text Articles in Engineering

Algorithm Development And Analysis For Advanced Enginetechnologies Including Piezoelectric Fuel Injection And Variablevalve Actuation, Bradley W. Pietrzak Oct 2014

Algorithm Development And Analysis For Advanced Enginetechnologies Including Piezoelectric Fuel Injection And Variablevalve Actuation, Bradley W. Pietrzak

Open Access Theses

As vehicle emissions standards and fuel economy constraints become increasingly strict, the automotive industry must employ the use of advanced engine technologies to overcome these challenges. Fuel injection rate shaping and cylinder deactivation (CDA) are two such technologies, and both of them require the design and implementation of algorithms using various hardware and software tools.

Fuel injection rate shaping is one path towards cleaner and more efficient diesel engines. Piezoelectrically-actuated fuel injectors are well-suited for rate shaping operation, but are difficult to control. Control-related challenges arise primarily due to the lack of measurements available in a fuel injection system on-engine, …


System Identification Of An Unmanned Tailsitter Aircraft, Nathan W. Edwards Aug 2014

System Identification Of An Unmanned Tailsitter Aircraft, Nathan W. Edwards

Theses and Dissertations

The motivation for this research is the need to improve performance of the autonomous flight of a tailsitter UAV. Tailsitter aircraft combine the hovering and vertical take-off and landing capability of a rotorcraft with the long endurance flight capability of a fixed-wing aircraft. The particular aircraft used in this research is the V-Bat, a tailsitter UAV with a conventional wing and the propeller and control surfaces located within a ducted-fan tail assembly. This research focuses on identifying the models and parameters of the V-Bat in hover and level flight as a basis for the design of the control systems for …


Overview And Application Of The Model Optimization, Uncertainty, And Sensitivity Analysis (Mouse) Toolbox, James C. Ascough Ii, Christian Fischer, Nathan Lighthart, Olaf David, Timothy R. Green, Sven Kralisch Jun 2014

Overview And Application Of The Model Optimization, Uncertainty, And Sensitivity Analysis (Mouse) Toolbox, James C. Ascough Ii, Christian Fischer, Nathan Lighthart, Olaf David, Timothy R. Green, Sven Kralisch

International Congress on Environmental Modelling and Software

For several decades, optimization and sensitivity/uncertainty analysis of environmental models has been the subject of extensive research. Although much progress has been made and sophisticated methods developed, the growing complexity of environmental models to represent real­ world systems makes it increasingly difficult to fully comprehend model behavior, sensitivities and uncertainties. This paper provides an overview of the Model Optimization, Uncertainty, and SEnsitivity Analysis (MOUSE) software application, an open-source, Java-based toolbox of visual and numerical analysis components for the evaluation of environmental models. MOUSE is based on the OPTAS model calibration system developed for the Jena Adaptable Modeling System framework, is …


An Inverse Pod-Rbf Network Approach To Parameter Estimation In Mechanics, Craig A. Rogers, Alain Kassab, Eduardo Divo, Ziemowit Ostrowski, Ryszard Bialecki May 2014

An Inverse Pod-Rbf Network Approach To Parameter Estimation In Mechanics, Craig A. Rogers, Alain Kassab, Eduardo Divo, Ziemowit Ostrowski, Ryszard Bialecki

Eduardo Divo

An inverse approach is formulated using proper orthogonal decomposition (POD) integrated with a trained radial basis function (RBF) network to estimate various physical parameters of a specimen with little prior knowledge of the system. To generate the truncated POD-RBF network utilized in the inverse problem, a series of direct solutions based on FEM, BEM or exact analytical solutions are used to generate a data set of temperatures or deformations within the system or body, each produced for a unique set of physical parameters. The data set is then transformed via POD to generate an orthonormal basis to accurately solve for …


Speech Enhancement Using Bayesian Estimators Of The Perceptually-Motivated Short-Time Spectral Amplitude (Stsa) With Chi Speech Priors, Marek B. Trawicki, Michael T. Johnson Feb 2014

Speech Enhancement Using Bayesian Estimators Of The Perceptually-Motivated Short-Time Spectral Amplitude (Stsa) With Chi Speech Priors, Marek B. Trawicki, Michael T. Johnson

Electrical and Computer Engineering Faculty Research and Publications

In this paper, the authors propose new perceptually-motivated Weighted Euclidean (WE) and Weighted Cosh (WCOSH) estimators that utilize more appropriate Chi statistical models for the speech prior with Gaussian statistical models for the noise likelihood. Whereas the perceptually-motivated WE and WCOSH cost functions emphasized spectral valleys rather than spectral peaks (formants) and indirectly accounted for auditory masking effects, the incorporation of the Chi distribution statistical models demonstrated distinct improvement over the Rayleigh statistical models for the speech prior. The estimators incorporate both weighting law and shape parameters on the cost functions and distributions. Performance is evaluated in terms of the …


Constant-Stress Accelerated Life Test Of White Organic Light-Emitting Diode Based On Least Square Method Under Weibull Distribution, J Zhang, C Liu, G Cheng, X Chen, J Wu, Q Zhu, Laichang Zhang Jan 2014

Constant-Stress Accelerated Life Test Of White Organic Light-Emitting Diode Based On Least Square Method Under Weibull Distribution, J Zhang, C Liu, G Cheng, X Chen, J Wu, Q Zhu, Laichang Zhang

Research outputs 2014 to 2021

It is currently hard to estimate the reliability parameters of organic light-emitting diodes (OLEDs) when conducting a life test at normal stress, due to the remarkably improved life of OLEDs to thousands hours. This work adopted three constant-stress accelerated life tests (CSALTs) to predict the life of white OLEDs in a short time. The Weibull function was applied to describe the life distribution, and the shape and scale parameters were estimated using the least square method. The experimental test data were statistically analyzed using a self-developed software. The life of white OLEDs predicted via this software is in good agreement …


Multiple-Global-Best Guided Artificial Bee Colony Algorithm For Induction Motor Parameter Estimation, Abdul Ghani Abro, Junita Mohamad Saleh Jan 2014

Multiple-Global-Best Guided Artificial Bee Colony Algorithm For Induction Motor Parameter Estimation, Abdul Ghani Abro, Junita Mohamad Saleh

Turkish Journal of Electrical Engineering and Computer Sciences

An induction motor is the most commonly used motor in industry today. Motor circuit parameters are essential for designing, evaluating performance, and controlling the applications of the motor. However, it is difficult to measure the electric parameters, e.g., resistance and reactance, of induction motors accurately. Therefore, researchers have noted the parameter estimation of induction motors as an essential optimization problem. The artificial bee colony (ABC) algorithm is an efficient element of bioinspired optimization algorithms and has been successfully applied in numerous engineering applications. However, the ABC algorithm suffers from slow convergence and poor exploitation. Additionally, there are bleak chances of …


Metaheuristic Linear Modeling Technique For Estimating The Excitation Current Of A Synchronous Motor, Hamdi̇ Tolga Kahraman Jan 2014

Metaheuristic Linear Modeling Technique For Estimating The Excitation Current Of A Synchronous Motor, Hamdi̇ Tolga Kahraman

Turkish Journal of Electrical Engineering and Computer Sciences

The subject of modeling and estimating of synchronous motor (SM) parameters is a challenge mathematically. Although effective solutions have been developed for nonlinear systems in artificial intelligence (AI)-based models, problems are faced with the application of these models in power circuits in real-time. One of these problems is the delay time resulting from a complex calculation process and thus the difficulties faced in the design of real-time motor driving circuits. Another important problem regards the difficulty in the realization of a complex AI-based model in microprocessor-based real-time systems. In this study, a new hybrid technique is developed to solve the …