Engineering Commons^™

Text Versus Verbal Real-Time Feedback During Simulation-Based Training Of Higher-Order Cognitive Skills, C L. Fiorella

Electronic Theses and Dissertations

A crucial component of instructional design for simulation-based training systems involves optimizing the presentation of complex material in order to maximize knowledge acquisition and application. One approach toward facilitating the learning of this complex information is to instantiate instructional strategies within the training systems themselves. However, there are few established guidelines in place which are meant specifically for real-time guidance strategies within simulation-based environments. Consequently, this study aims to apply findings from the literature on instructional information presentation to drive decisions for how to most effectively provide real-time feedback during training of simulated decision-making tasks. Research has shown that presenting …

Query Processing In Location-Based Services, Fuyu Liu

Electronic Theses and Dissertations

With the advances in wireless communication technology and advanced positioning systems, a variety of Location-Based Services (LBS) become available to the public. Mobile users can issue location-based queries to probe their surrounding environments. One important type of query in LBS is moving monitoring queries over mobile objects. Due to the high frequency in location updates and the expensive cost of continuous query processing, server computation capacity and wireless communication bandwidth are the two limiting factors for large-scale deployment of moving object database systems. To address both of the scalability factors, distributed computing has been considered. These schemes enable moving objects …

Perceived Service Quality's Impact On Behavioral Intentions In The Timeshare Industry, Leonard Pollar Ii

Electronic Theses and Dissertations

This study created a model using factor analysis and structural equation modeling to investigate the relationship of service quality, word-of-mouth recommendation and price sensitivity of individuals who experienced a timeshare mini vacation at a branded timeshare resort. The constructs of service quality were developed by creating a survey tool. A total of 4,797 surveys were electronically sent resulting in a total of 1,275 of the individuals surveyed who met the criteria of staying at a branded hotel or resort during their mini vacation. Six different variables were created from the ordinal level questions on the survey: Resort Accommodations, Sales Gallery, …

Extreme Ultraviolet Spectral Streak Camera, John Michael Szilagyi

Electronic Theses and Dissertations

The recent development of extreme ultraviolet (EUV) sources has increased the need for diagnostic tools, and has opened up a previously limited portion of the spectrum. With ultrafast laser systems and spectroscopy moving into shorter timescales and wavelengths, the need for nanosecond scale imaging of EUV is increasing. EUV’s high absorption has limited the number of imaging options due to the many atomic resonances in this spectrum. Currently EUV is imaged with photodiodes and X-ray CCDs. However photodiodes are limited in that they can only resolve intensity with respect to time and X-ray CCDs are limited to temporal resolution in …

A Taxonomy Of Lean Six Sigma Success Factors For Service Organizations, Reza N. Hajikordestani

Electronic Theses and Dissertations

Six Sigma is a business improvement strategy that aims to improve process performance using a structured methodology that identifies and removes the causes of defects in manufacturing and business processes, while implementing the lean concepts attempts to remove wasteful activities from those processes. In practice, the Six Sigma strategy and the Lean philosophy are combined and often viewed as one integrated philosophy, where the philosophy of Lean Six Sigma simultaneously removes wasteful activities from a process and reduces the variability of that process. This thesis research reviews the concepts and implementation of Lean thinking, Six Sigma strategy, and the integrated …

Thermally-Induced Motion Of Droplets On A Thin Liquid Layer And Its Application To Droplet Manipulation Platforms, Ehsan Yakhshi-Tafti

Electronic Theses and Dissertations

In the recent years, there has been a growing interest in droplet-based (digital) microfluidic systems due to their ability to handle multiple discrete samples in a self-contained configuration compared to continuous flow systems. Various methods for droplet manipulation are currently available based on hydrodynamic, electrostatic, chemical, photonic and thermal interactions. High speed, controlled response and minimal thermal loading with least contamination are required in practical applications, especially in chemistry and biology. Although, thermal actuation of droplets has been recognized as an attractive choice due to a wide range of thermomechanical properties that can be exploited, the previous studies yielded limited …

Mobility And Safety Evaluation Of Integrated Dynamic Merge And Speed Control Strategies In Work Zones, Syed Muhammad Zaidi

Electronic Theses and Dissertations

In recent years, there has been a considerable increase in the amount of construction work on the U.S. national highways. Most of the work undertaken is the reconstruction and rehabilitation of the existing transportation networks. Work zones in the United States are likely to increase in number, duration and length due to emphasis on repair and highway reconstruction as a significant portion of all federal-aid highway funds are now geared toward highway rehabilitation. The challenge of mobility is particularly acute in work zone areas as road repair and construction intensifies traffic issues and concentrates them in specific locations and at …

A Robust Wireless Mesh Access Environment For Mobile Video Users, Fei Xie

Electronic Theses and Dissertations

The rapid advances in networking technology have enabled large-scale deployments of online video streaming services in today's Internet. In particular, wireless Internet access technology has been one of the most transforming and empowering technologies in recent years. We have witnessed a dramatic increase in the number of mobile users who access online video services through wireless access networks, such as wireless mesh networks and 3G cellular networks. Unlike in wired environment, using a dedicated stream for each video service request is very expensive for wireless networks. This simple strategy also has limited scalability when popular content is demanded by a …

Design Of A Wideband Dual-Polarized Cavity Backed Slot Antenna, Rajesh Paryani

Electronic Theses and Dissertations

A new technique for designing wideband dual-polarized cavity-backed slot antennas is presented. The structure is in the form of a double-resonant, dual-polarized slot antenna backed by a shallow substrate integrated cavity with a depth of approximately one tenth the free space wavelength. The presence of the cavity behind the slot enhances the antenna's directivity and reduces the possibility of surface wave propagation in the antenna substrate when the element is used in an array environment. Moreover, the dual-polarized nature of this radiating element may be exploited to synthesize any desired polarization (vertical, horizontal, RHCP, or LHCP). The double-resonant behavior observed …

High Heat Flux Spray Cooling With Ammonia On Enhanced Surfaces, Huseyin Bostanci

Electronic Theses and Dissertations

Many critical applications today, in electronics, optics and aerospace fields, among others, demand advanced thermal management solutions for the acquisition of high heat loads they generate in order to operate reliably and efficiently. Current competing technologies for this challenging task include several single and two phase cooling options. When these cooling schemes are compared based on the high heat flux removal (100-1000 W/cm2) and isothermal operation (within several oC across the cooled device) aspects, as well as system mass, volume and power consumption, spray cooling appears to be the best choice. The current study focused on high heat flux spray …

Tunable Infrared Metamaterials, David Shelton

Electronic Theses and Dissertations

Metamaterials are engineered periodic composites that have unique refractive-index characteristics not available in natural materials. They have been demonstrated over a large portion of the electromagnetic spectrum, from visible to radiofrequency. For applications in the infrared, the structure of metamaterials is generally defined using electron-beam lithography. At these frequencies, the loss and dispersion of any metal included in the composite are of particular significance. In this regard, we investigate deviations from the Drude model due to the anomalous skin effect. For comparison with theoretical predictions, the optical properties of several different metals are measured, both at room temperature and at …

A Model Integrated Meshless Solver (Mims) For Fluid Flow And Heat Transfer, Salvadore Gerace

Electronic Theses and Dissertations

Numerical methods for solving partial differential equations are commonplace in the engineering community and their popularity can be attributed to the rapid performance improvement of modern workstations and desktop computers. The ubiquity of computer technology has allowed all areas of engineering to have access to detailed thermal, stress, and fluid flow analysis packages capable of performing complex studies of current and future designs. The rapid pace of computer development, however, has begun to outstrip efforts to reduce analysis overhead. As such, most commercially available software packages are now limited by the human effort required to prepare, develop, and initialize the …

An Interval Based Approach To Model Input Uncertainty In Discrete-Event Simulation, Ola Batarseh

Electronic Theses and Dissertations

The objective of this research is to increase the robustness of discrete-event simulation (DES) when input uncertainties associated models and parameters are present. Input uncertainties in simulation have different sources, including lack of data, conflicting information and beliefs, lack of introspection, measurement errors, and lack of information about dependency. A reliable solution is obtained from a simulation mechanism that accounts for these uncertainty components in simulation. An interval-based simulation (IBS) mechanism based on imprecise probabilities is proposed, where the statistical distribution parameters in simulation are intervals instead of precise real numbers. This approach incorporates variability and uncertainty in systems. In …

Impact Of Hurricanes On Structures - A Performance Based Engineering View, Vijay Mishra

Electronic Theses and Dissertations

The magnitude of damage caused to the United States (US) coast due to hurricanes has increased significantly in the last decade. During the period 2004-2005, the US experienced seven of the costliest hurricanes in the country's history (NWS TPC-5, 2007) leading to an estimated loss of ~ $158 billion. The present method for predicting hurricane losses, HAZUS (HAZard US), is solely based on hurricane hazard and damage caused to building envelopes only and not to structural systems (Vickery et al., 2006). This method does not take into account an intermediate step that allows for better damage estimates, which is structural …

The Pdf Of Irradiance For A Free-Space Optical Communications Channel: A Physics Based Model, David Wayne

Electronic Theses and Dissertations

An accurate PDF of irradiance for a FSO channel is important when designing a laser radar, active laser imaging, or a communications system to operate over the channel. Parameters such as detector threshold level, probability of detection, mean fade time, number of fades, BER, and SNR are derived from the PDF and determine the design constraints of the receiver, transmitter, and corresponding electronics. Current PDF models of irradiance, such as the Gamma-Gamma, do not fully capture the effect of aperture averaging; a reduction in scintillation as the diameter of the collecting optic is increased. The Gamma-Gamma PDF of irradiance is …

Processing, Optimization And Characterization Of Fire Retardant Polymer Nanocomposites, Jinfeng Zhuge

Electronic Theses and Dissertations

Fiber reinforced polymeric composites (FRPC) have superior physical and mechanical properties, such as high specific strength, light weight, and good fatigue and corrosion resistance. They have become competitive engineering materials to replace conventional metallic materials in many important sectors of industry such as aircraft, naval constructions, ships, buildings, transportation, electrical and electronics components, and offshore structures. However, since FRPC contain polymer matrix, the polymer composites and their structures are combustible. FRPC will degrade, decompose, and sometimes yield toxic gases at high temperature or subject to fire conditions. The objective of this study is to design and optimize fire retardant nanopaper …

On The Use Of Polyurethane Matrix Carbon Fiber Composites For Strengthening Concrete Structures, Zachary Haber

Electronic Theses and Dissertations

Fiber-reinforced polymer (FRP) composite materials have effectively been used in numerous reinforced concrete civil infrastructure strengthening projects. Although a significant body of knowledge has been established for epoxy matrix carbon FRPs and epoxy adhesives, there is still a need to investigate other matrices and adhesive types. One such matrix/adhesive type yet to be heavily researched for infrastructure application is polyurethane. This thesis investigates use of polyurethane matrix carbon fiber composites for strengthening reinforced concrete civil infrastructure. Investigations on mirco- and macro-mechanical composite performance, strengthened member flexural performance, and bond durability under environmental conditioning will be presented. Results indicate that polyurethane …

Hurricane Wind Speed And Rain Rate Measurements Using The Airborne Hurricane Imaging Radiometer (Hirad), Ruba Amarin

Electronic Theses and Dissertations

This dissertation presents results for an end-to-end computer simulation of a new airborne microwave remote sensor, the Hurricane Imaging Radiometer, HIRAD, which will provide improved hurricane surveillance. The emphasis of this research is the retrieval of hurricane-force wind speeds in the presence of intense rain and over long atmospheric slant path lengths that are encountered across its wide swath. Brightness temperature (Tb) simulations are performed using a forward microwave radiative transfer model (RTM) that includes an ocean surface emissivity model at high wind speeds developed especially for HIRAD high incidence angle measurements and a rain model for the hurricane environment. …

Conventional And Zvt Synchronous Buck Converter Design, Analysis, And Measurement, Mark Cory

Electronic Theses and Dissertations

The role played by power converting circuits is extremely important to almost any electronic system built today. Circuits that use converters of any type depend on power that is consistent in form and reliable in order to properly function. In addition, today's demands require more efficient use of energy, from large stationary systems such as power plants all the way down to small mobile devices such as laptops and cell phones. This places a need to reduce any losses to a minimum. The power conversion circuitry in a system is a very good place to reduce a large amount of …

Probing The Nanoscale Interaction Forces And Elastic Properties Of Organic And Inorganic Materials Using Force-Distance (F-D) Spectroscopy, Abhilash Vincent

Electronic Theses and Dissertations

Due to their therapeutic applications such as radical scavenging, MRI contrast imaging, Photoluminescence imaging, drug delivery, etc., nanoparticles (NPs) have a significant importance in bio-nanotechnology. The reason that prevents the utilizing NPs for drug delivery in medical field is mostly due to their biocompatibility issues (incompatibility can lead to toxicity and cell death). Changes in the surface conditions of NPs often lead to NP cytotoxicity. Investigating the role of NP surface properties (surface charges and surface chemistry) on their interactions with biomolecules (Cells, protein and DNA) could enhance the current understanding of NP cytotoxicity. Hence, it is highly beneficial to …

Development Of A Cloud Solution For Smes In The Irish Construction Industry, Alan V. Hore, Alan Redmond, Roger West

Conference papers

There is a strong emerging trend within the Information Communication Technology (ICT) sector for replacing traditional packaged desktop applications with Web based, outsourced products and services. The drive for this innovative solution is its contribution to enabling software to be developed, delivered and consumed in discrete chunks (known as services) liberating the users from traditional computing and providing services accessible across a range of devices and appliances. The objective of this paper is to report on the progress towards defining this Web based service, commonly known as ‘Cloud computing’, for Small to Medium Size Enterprises (SMEs) in the Irish construction …

Single Channel Vocal Separation Using Median Filtering And Factorisation Techniques, Derry Fitzgerald, Mikel Gainza

Articles

This paper deals with the problem of the extraction of vocals from single channel audio signals containing both vocals and other instruments, including both pitched instruments and percussion instruments. A novel median filtering-based approach for the extraction of vocal tracks is described, which is simple and efficient to implement. Further improvements in separation quality are then obtained by the application of tensor factorisation techniques to further extract residual instruments from the vocal mix. Finally, a novel use of non-negative partial matrix cofactorisation is demonstrated as a means of further improving separation quality. Here the original single channel mixture is partially …

The Fractal Market Hypothesis: Applications To Financial Forecasting, Jonathan Blackledge

Books/Book chapters

No abstract provided.

Connecting Micro-Generators In Parallel To The Low Voltage Distribution Network Utilising Standard En50438 In The Republic Of Ireland, Liam Murphy

Other resources

The green agenda has been much to the fore internationally and has particularly had an influence in Republic of Ireland (ROI) where there are ‘green’ ministers in Government. Mr. Eamon Ryan who is the Minister for Communications, Energy and Natural Resources has particularly championed the idea of self generation. The author’s interest in the subject matter is to investigate the up-take of micro-generation and determine the likely short term future along with the grid tie standard i.e. EN50438.

Issues surrounding micro-generation are considered from the international and national perspective and from a customer and generation utility point of view. The …

The Measurement Of Success In External Engagement Activities, Mike Murphy

Conference papers

Our ambition is to identify, through the presentations and the discussion, a number of key insights and necessary actions for development of more and deeper partnerships between Higher Education Institutions and Employers.

Blind Single Channel Sound Source Separation, Mark Leddy

Masters

In recent years source separation has become an increasingly popular area of research in the signal processing community. The subject has found applications in a variety of fields such as medical imaging, sound and audio, econometrics and geophysics. This document will discuss the application of source separation techniques to the area of audio. Sound source separation is the process of observing a mixture signal made up of a number of sources, and from this mixture estimating the individual source signals. Audio source separation techniques may be crudely split into the following areas; techniques that utilise attributes of the sources, and …

Development Of A Moodle Vle Plug-In To Support Simultaneous Visualisation Of A Collection Of Multi-Media Sign Language Objects, Brian Nolan

Conference Papers

Using Virtual Learning Environments (VLE) to support blended learning is very common in educational institutes. Delivering learning material in a flexible and semi-structured manner to the learner transforms such systems into powerful eLearning tools. However, the presentation and visualisation of individual or multiple learning objects is mostly dictated by the system and cannot be altered easily. This paper reports on a project between Trinity College Dublin (TCD) and the Institute of Technology Blanchardstown (ITB) that aims to improve the simultaneous visualisation of multiple multimedia objects for deaf learners of ISL. The project was implemented using the Open Source VLE Moodle. …

Quantification Of Vascular Parametric Indices Using Dynamic Contrast-Enhanced Magnetic Resonance Imaging, Areen Khaled Al.Bashir

Wayne State University Dissertations

Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) is a non-invasive method used to evaluate the biological activity in early clinical trials of novel drugs targeting the tumor vasculature using gadolinium-DTPA (Gd) as a contrast agent. However, it has some limitations, such as reproducibility, data acquisition times, the presence of noise, extracting contrast concentration, estimating T1 relaxation and estimating pharmacokinetic parameters.

In this work, a new approach to used fixed T1(0) which provides more reproducible DCE results has been introduced. Using this new algorithm to quantify the vascular changes in DCE-MRI, a pre-clinical renal cell carcinoma (RCC) tumor model was used to …

Computational Structural Modelling Of Coronary Stent Deployment: A Review, David Martin, Fergal Boyle

Articles

The finite element (FE) method is a powerful investigative tool in the field of biomedical engineering, particularly in the analysis of medical devices such as coronary stents whose performance is extremely difficult to evaluate in vivo. In recent years, a number of FE studies have been carried out to simulate the deployment of coronary stents, and the results of these studies have been utilised to assess and optimise the performance of these devices. The aim of this paper is to provide a thorough review of the state-of-the-art research in this area, discussing the aims, methods and conclusions drawn from a …

Nebraska Water And Energy Flux Measurement, Modeling, And Research Network (Nebflux), Suat Irmak

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Surface energy and water vapor fluxes play a critical role in understanding the response of agro‐ecosystems to changes in environmental and atmospheric parameters. These fluxes play a crucial role in exploring the dynamics of water and energy use efficiencies of these systems. Quantification of the fluxes is also necessary for assessing the impact of land use and management changes on water balances. Accomplishing these goals requires measurement of water vapor and energy exchanges between various vegetation surfaces and microclimates for long‐enough periods to understand the behavior and dynamics involved with the flux transfer so that robust models can be developed …