Engineering Commons^™

Evaluation Of Prefermentation As A Unit Process Upon Biological Nutrient Removal Including Biokinetic And Wastewater Parameters, Terrence Mccue

Electronic Theses and Dissertations

The objective of this dissertation was to provide a controlled comparison of identical continuous flow BNR processes both with and without prefermentation in order to provide a stronger, more quantitative, technical basis for design engineers to evaluate the potential benefits of prefermentation to EBPR in treating domestic wastewater. In addition, the even less understood effect of prefermentation on denitrification kinetics and anoxic phosphorus (P) uptake was studied and quantified. Other aspects of BNR performance, which might change due to use of prefermentation, will also be addressed, including anaerobic stabilization. Potential benefits to BNR processes derived from prefermentation are compared and …

Quantitative Assessment Of Software Development Project Management Issues Using Process Simulation With System Dynamics Elements, Carolyn Mizell

Electronic Theses and Dissertations

The complexity of software development projects makes estimation and management very difficult. There is a need for improved cost estimation methods and new models of lifecycle processes other than the common waterfall process. This work has developed a new simulation model of the spiral development lifecycle as well as an approach for using simulation for cost and schedule estimation. The goal is to provide a tool that can analyze the effects of a spiral development process as well as a tool that illustrates the difficulties management faces in forecasting budgets at the beginning of a project which may encourage more …

Change Orders And Productivity Loss Quantification Using Verifiable Site Data, Engy Serag

Electronic Theses and Dissertations

Change orders occur frequently in most construction projects, where contract modifications that increase the contract value between 5 to 10% are expected. Changes occur not only because of errors and omissions, but also for other reasons such as scope of work changes, or changes because of unforeseen conditions encountered on the site; a problem which is very common in most heavy construction projects. Changes themselves might not cause productivity losses; in this case the damage calculation will be straightforward. However, changes may cause disruption in unchanged work where the working conditions are impacted, and as a result, lost productivity (inefficiency) …

Finite Element Method Modeling Of Advanced Electronic Devices, Yupeng Chen

Electronic Theses and Dissertations

In this dissertation, we use finite element method together with other numerical techniques to study advanced electron devices. We study the radiation properties in electron waveguide structure with multi-step discontinuities and soft wall lateral confinement. Radiation mechanism and conditions are examined by numerical simulation of dispersion relations and transport properties. The study of geometry variations shows its significant impact on the radiation intensity and direction. In particular, the periodic corrugation structure exhibits strong directional radiation. This interesting feature may be useful to design a nano-scale transmitter, a communication device for future nano-scale system. Non-quasi-static effects in AC characteristics of carbon …

Pipelining Of Double Precision Floating Point Division And Square Root Operations On Field-Programmable Gate Arrays, Anuja Thakkar

Electronic Theses and Dissertations

Many space applications, such as vision-based systems, synthetic aperture radar, and radar altimetry rely increasingly on high data rate DSP algorithms. These algorithms use double precision floating point arithmetic operations. While most DSP applications can be executed on DSP processors, the DSP numerical requirements of these new space applications surpass by far the numerical capabilities of many current DSP processors. Since the tradition in DSP processing has been to use fixed point number representation, only recently have DSP processors begun to incorporate floating point arithmetic units, even though most of these units handle only single precision floating point addition/subtraction, multiplication, …

Sensitivity Analysis Of Aashto's 2002 Flexible And Rigid Pavement Design Methods, Sanjay Shahji

Electronic Theses and Dissertations

Over the years pavement design has been based on empirical equations developed from the American Association of State Highway Transportation Officials (AASHTO) road tests. The various editions of the AASHTO pavement design guide have served well for several decades; nevertheless many serious limitations existed for their continued use as the nation's primary pavement design procedure. For example, the traffic loads and truck sizes have increased over the years, the AASHTO design equations were derived based on the climatic conditions present at the Road Tests site, and the issue of aging materials was not addressed in the design. To overcome these …

Modeling Of Atmospheric Refraction Effects On Traffic Noise Propagation, Ahmed El-Aassar

Electronic Theses and Dissertations

Traffic noise has been shown to have negative effects on exposed persons in the communities along highways. Noise from transportation systems is considered a nuisance in the U.S. and the government agencies require a determination of noise impacts for federally funded projects. There are several models available for assessing noise levels impacts. These models vary from simple charts to computer design models. Some computer models, i.e. Standard Method In Noise Analysis (STAMINA), the Traffic Noise Model (TNM) and the UCF Community Noise Model (CNM), have been used to predict geometric spreading, atmospheric absorption, diffraction, and ground impedance. However, they have …

Polarimetry Of Random Fields, Jeremy Ellis

Electronic Theses and Dissertations

On temporal, spatial and spectral scales which are small enough, all fields are fully polarized. In the optical regime, however, instantaneous fields can rarely be examined, and, instead, only average quantities are accessible. The study of polarimetry is concerned with both the description of electromagnetic fields and the characterization of media a field has interacted with. The polarimetric information is conventionally presented in terms of second order field correlations which are averaged over the ensemble of field realizations. Motivated by the deficiencies of classical polarimetry in dealing with specific practical situations, this dissertation expands the traditional polarimetric approaches to include …

Molecular Structure-Nonlinear Optical Property Relationships For A Series Of Polymethine And Squaraine Molecules, Jie Fu

Electronic Theses and Dissertations

This dissertation reports on the investigation of the relationships between molecular structure and two-photon absorption (2PA) properties for a series of polymethine and squaraine molecules. Current and emerging applications exploiting the quadratic dependence upon laser intensity, such as two-photon fluorescence imaging, three-dimensional microfabrication, optical data storage and optical limiting, have motivated researchers to find novel materials exhibiting strong 2PA. Organic materials are promising candidates because their linear and nonlinear optical properties can be optimized for applications by changing their structures through molecular engineering. Polymethine and squaraine dyes are particularly interesting because they are fluorescent and showing large 2PA. We used …

A Dynamic Heuristic For The Stochastic Unrelated Parallel Machine Scheduling Problem, Jean-Paul Arnaout, Ghaith Rabadi, Ji Hyon Mun

Engineering Management & Systems Engineering Faculty Publications

This paper addresses the problem of batch scheduling in an unrelated parallel machine environment with sequence dependent setup times and an objective of minimizing the total weighted mean completion time. The jobs' processing times and setup times are stochastic for better depiction of the real world. This is a NP-hard problem and in this paper, new heuristics are developed and compared to existing ones using simulation. The results and analysis obtained from the computational experiments proved the superiority of the proposed algorithm PMWP over the other algorithms presented.

An Interval Type-Ii Robust Fuzzy Logic Controller For A Static Compensator In A Multimachine Power System, Salman Mohagheghi, Ganesh K. Venayagamoorthy, Ronald G. Harley

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents a novel fuzzy logic based controller for a Static Compensator (STATCOM) connected to a power system. Type-II fuzzy systems are selected that enable the controller to deal with design uncertainties and the noise associated with the measurements in the power system. Interval type-II fuzzy is computationally more effective than the ordinary type-II fuzzy systems and is more suitable for the power network with fast changing dynamics. Using a proportional-integrator approach the proposed controller is capable of dealing with actual rather than deviation signals. The STATCOM is connected to a multimachine power system in order to provide extra …

Bacteria Foraging: A New Tool For Simultaneous Robust Design Of Upfc Controllers, M. Tripathy, S. Mishra, Ganesh K. Venayagamoorthy

Electrical and Computer Engineering Faculty Research & Creative Works

Robust tuning of lead-lag type controller used for regulating FACTS control signal to improve dynamic stability has been an area of interest in research. This paper presents a new approach based on the foraging behavior of E. coli Bacteria in the human intestine, to optimize simultaneously three constants each of four lead-lag type UPFC controller present in a Single Machine Infinite Bus (SMIB) power system. For the tuning purpose, a multi-objective cost function is formulated that accounts for damping factors and ratios of various system modes for a wide range of operating conditions. Robustness of the proposed tuning method is …

Comparison Of Two Optimal Control Strategies For A Grid Independent Photovoltaic System, Richard L. Welch, Ganesh K. Venayagamoorthy

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents two optimal control strategies for a grid independent photovoltaic system consisting of a PV collector array, a storage battery, and loads (critical and non-critical loads). The first strategy is based on Action Dependent Heuristic Dynamic Programming (ADHDP), a model-free adaptive critic design (ACD) technique which optimizes the control performance based on a utility function. ADHDP critic network is used in a PV system simulation study to train an action neural network (optimal neurocontroller) to provide optimal control for varying PV system output energy and loadings. The second optimal control strategy is based on a fuzzy logic controller …

Posture-Induced Changes In Distortion-Product Otoacoustic Emissions And The Potential For Noninvasive Monitoring Of Changes In Intracranial Pressure, Susan E. Voss, Nicholas J. Horton, Taronne H. P. Tabucchi, Fopefolu O. Folowosele, Christopher A. Shera

Engineering: Faculty Publications

Introduction

Intracranial pressure (ICP) monitoring is currently an invasive procedure that requires access to the intracranial space through an opening in the skull. Noninvasive monitoring of ICP via the auditory system is theoretically possible because changes in ICP transfer to the inner ear through connections between the cerebral spinal fluid and the cochlear fluids. In particular, low-frequency distortion-product otoacoustic emissions (DPOAEs), measured noninvasively in the external ear canal, have magnitudes that depend on ICP. Postural changes in healthy humans cause systematic changes in ICP. Here, we quantify the effects of postural changes, and presumably ICP changes, on DPOAE magnitudes.

Methods …

Development Of A Service-Oriented Communication Platform For Heterogeneous Voice Over Ip Networks., Aisling O'Driscoll

Theses

As broadband services have become more widespread in recent years due to a variety of government initiatives and the establishment of Wireless Internet Service Providers, user requirements have evolved and the market has become more competitive. Whilst this is beneficial for consumers it means that Internet Service Providers must offer a more diverse range of services coupled with standard broadband packages to distinguish themselves from their competitors, generate new revenue and strengthen their competitive advantage. Therefore many providers are looking to Service Oriented Architectures (SOAs) to provide communication platforms, enabling services such as Voice over IP (VoIP) along with other …

A Low Noise Amplifier For An Ultra Wideband Receiver, Tomasz Waliwander

Theses

The Ultra Wideband Technology, although derives from the early works on time-domain electromagnetics, only recently attracted the attention of the research and industrial institutions, mainly thanks to establishing a proper frequency mask by Federal Communication Commission. The FCC regulations allocate the immense 3.1 - 10.6 GHz microwave band that has never been accessible in a one segment before.

The intrinsic features of the UWB radio such as low power, immunity to multipath fading and eavesdropping, high 3D resolution capability and ability of'seeing' through the solid obstacles with addition to achievable very high data rates, makes it very attractive for many …

Linux Based Pda Gateway For Wireless Sensor Networks, Áine Mccarthy

Theses

Recent years have seen a dramatic increase in the development and deployment of intelligent sensors and their use with a plethora of networking protocol technologies. Wireless Sensor Networks (WSN) can be used to monitor the environment, objects in the environment and the interaction of these objects with each other. Examples include environment and habitat monitoring, structural monitoring, disaster management and emergency response. The deployment of such large-scale WSN possess many challenges, the most important being scalability, portability, fault tolerance, adaptability and ubiquitous connectivity. There also exist many challenges when trying to establish communication with WSN. WSN can function as a …

Disappearing User Interface In Ubiquitous Computing: A Pointing And Gesture Sensing System Using An Ultrasonic And Radio Frequency Location Technology, Stephania Yimana Kigadye

Theses

Weiser’s [1] vision of ubiquitous computing presents a different paradigm of computing which attempts to push computers into the background towards invisibility. Therefore “new concepts for human-computer interaction have to be developed when envisioning ubiquitous computing scenarios [1]. Instead of a single screen-based user interface (UI), humans will interact with a number of devices that are distributed and interconnected. These eomputers range from highly personal and mobile applianees to systems that are integrated in everyday environments and are more or less invisible.”[7] As this project suggests, a disappearing user interface in ubiquitous computing can be designed as a gesture recognition …

Forecasting Using The Mahalanobis-Taguchi System In The Presence Of Collinearity, Elizabeth A. Cudney, Kenneth M. Ragsdell

Engineering Management and Systems Engineering Faculty Research & Creative Works

The Mahalanobis Taguchi System is a diagnosis and forecasting method for multivariate data. Mahalanobis distance is a measure based on correlations between the variables and different patterns that can be identified and analyzed with respect to a base or reference group. the issue of multicollinearity is not adequately addressed in the MTS method. in cases where strong relationships exist between variables, the correlation matrix becomes almost singular, and the inverse matrix is not accurate. Multicollinearity can be handled by utilizing the adjoint matrix of the correlation matrix and Gram-Schmidt orthogonalization. This paper presents a case study of the MTS methodology …

Gene Expression Data For Dlbcl Cancer Survival Prediction With A Combination Of Machine Learning Technologies, Rui Xu, Xindi Cai, Donald C. Wunsch

Electrical and Computer Engineering Faculty Research & Creative Works

Gene expression profiles have become an important and promising way for cancer prognosis and treatment. In addition to their application in cancer class prediction and discovery, gene expression data can be used for the prediction of patient survival. Here, we use particle swarm optimization (PSO) to address one of the major challenges in gene expression data analysis, the curse of dimensionality, in order to discriminate high risk patients from low risk patients. A discrete binary version of PSO is used for gene selection and dimensionality reduction, and a probabilistic neural network (PNN) is implemented as the classifier. The experimental results …

Hierarchical Control Scheme For Two Static Compensators In The Brazilian 45-Bus Power System, Salman Mohagheghi, Ganesh K. Venayagamoorthy, Yamille Del Valle, Ronald G. Harley

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.

Identification Of Svc Dynamics Using Wide Area Signals In A Power System, Ganesh K. Venayagamoorthy, Sandhya R. Jetti

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents the design of a wide area monitor (WAM) using remote area signals, such as speed deviations of generators in a power network, for identifying online the dynamics of a static var compensator (SVC). The design of the WAM is studied on the 12 bus FACTS benchmark system recently introduced. A predict-correct method is used to enhance the performance of the WAM during online operation. Simulation results are presented to show that WAM can correctly identify the dynamics of SVC in a power system for small and large disturbances. Such WAMs can be applied in the design of …

Laser Optical In-Circuit Measurement System For Immunity Applications, Chong Ding, David Pommerenke

Electrical and Computer Engineering Faculty Research & Creative Works

During immunity testing (ESD, EFT) of a digital circuit, the waveforms of critical signal nets need to be measured for analyzing the failure mechanism. However, it is difficult to measure the induced voltage in the circuit under test due to the unwanted coupling by the non-ideal shielding of the probe cable, especially, if large common mode currents are present. Fiber optical connection avoids this problem. Semiconductor lasers have frequently been used for converting the voltage into an optical signal. The paper shows novel implementations of powering the laser, leading to a small, low cost optical probe.

Multiple Statcom Allocation And Sizing Using Particle Swarm Optimization, Ganesh K. Venayagamoorthy, J. C. Hernandez, Yamille Del Valle, Ronald G. Harley

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.

Particle Swarm Optimization Based Defensive Islanding Of Large Scale Power System, Wenxin Liu, Ganesh K. Venayagamoorthy, David A. Cartes

Electrical and Computer Engineering Faculty Research & Creative Works

Defensive islanding is an efficient way to avoid catastrophic failures and wide area blackouts. Power system splitting especially for large scale power systems is a combinatorial explosion problem. Thus, it is very difficult to find an optimal solution (if one exists) for large scale power system in real time. This paper proposes to utilize the computational efficiency property of Binary Particle Swarm Optimization (BPSO) to find some efficient splitting solutions in limited timeframe. The solutions are optimized based on a cost function considering the balance between real power generation and consumption, the relative importance of customers, the capacities of distribution …

Real-Time Implementation Of An Optimal Transient Neurocontroller For A Gcsc, Swakshar Ray, Ganesh K. Venayagamoorthy

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents the design of an optimal Auxiliary Transient Neurocontroller (ATNC) for the Gate Controlled Series Capacitor (GCSC) in a multi-machine power system. GCSC is a recent advancement in the family of series FACTS devices. While GCSC regulates power flow through a transmission line, an auxiliary control signal can provide damping to the power oscillations during disturbances. The ATNC has been designed using heuristic dynamic programming to develop an optimal neurocontroller with fixed weights. The ATNC is implemented in real-time using the TMS3206701 DSP and the Real-Time Digital Simulator (RTDS). Results are presented to show the effectiveness of the …

Robustness And Distance Discrimination Of Adaptive Near Field Beamformers, Y. Rosa Zheng, Peng Xie, Steven L. Grant

Electrical and Computer Engineering Faculty Research & Creative Works

A robust adaptive beamformer is proposed using the near field regionally constrained adaptive approach that designs a set of linear constraints by filtering on a low rank subspace of the near field signal over a spatial region and a wide frequency band. This method can accurately control the beam-former response over the designed spatial-temporal region using a small number of linear constraint vectors and improve the robustness against target location errors. Meanwhile, this method enhances the capability of the near field beamformer in distance discrimination without additional constraints so that interference impinging at the same direction as the desired signal …

Vibration Testing Of Repaired Lead-Tin/Lead-Free Solder Joints, Matthew O'Keefe, S. Vetter, D. Murry, J. Smith, P. Amick, Martin G. Perez, D. W. Kleine, Richard S. Colfax

Materials Science and Engineering Faculty Research & Creative Works

No abstract provided.

Effect Of Nozzle Base Material On The Rate Of Clogging During The Continuous Casting Of Aluminum-Killed Steels, Luis Trueba, Kent D. Peaslee, Jeffrey D. Smith, Musa Karakus

Materials Science and Engineering Faculty Research & Creative Works

One approach to solving the problem of nozzle clogging during the continuous casting of aluminum-killed steels is through careful selection of nozzle materials. in this study, the rate of clogging was measured while casting steel through simulated nozzles produced from alumina, zirconia, magnesia, zirconia-graphite, and alumina-graphite - three common base materials and two common carbon-containing nozzle materials. Spent nozzles were characterized using optical and cathodoluminescence microscopy. Interactions between the nozzles and steel were not observed in the alumina, zirconia, and zirconia-graphite nozzles. Slight interactions were observed in the magnesia nozzles as alumina inclusions within the steel interacted with the nozzle …

Regulation Of Powder Mass Flow Rate In Gravity-Fed Powder Feeder Systems, Vishnu Thayalan, Robert G. Landers

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Precise regulation of powder mass flow in laser-based manufacturing processes is critical to achieving excellent part dimensional and microstructure quality. Control of powder mass flow is challenging because low flow rates, where nonlinear effects are significant, are typically required. Also, gravity-fed powder feeder systems have significant material transport delays, making the control of powder mass flow even more challenging. This paper presents a control strategy for regulating the powder mass flow rate in a gravity-fed powder feeder system. A dynamic model of the powder feeder system, including material transport delay, is constructed, and a modified proportional plus integral (PI) controller …