Digital Commons Network^™

The Impact Of Communication Medium On Team Performance Patterns, Pilar Pazos, Mario G. Beruvides

Engineering Management & Systems Engineering Faculty Publications

The increased impact of globalization and rapidly changing technologies are some of the biggest challenges facing 21st century organizations. Remote teams supported through computer-based systems have been identified as a key lever to help organizations adapt to this turbulent environment. This study sheds some light on how teams perform and adapt by evaluating performance and synergy over time for teams in two different settings: computer supported and face-to-face. Participants in the study were randomly assigned either to a computer-supported or a face-to face group. Each group met over three sessions to perform a series of tasks that were evaluated using …

Engineering Tool For Temperature, Electric Field And Dose Rate Dependence Of High Resistivity Spacecraft Materials, John R. Dennison, Alec Sim, Jerilyn Brunson, Steven Hart, Jodie Gillespie, Justin Dekany, Charles Sim, Dan Arnfield

All Physics Faculty Publications

An engineering tool has been developed to predict the equilibrium conductivity of common spacecraft insulating materials as a function of electric field, temperature, and adsorbed dose rate based on parameterized, analytic functions derived from physics-based theories. The USU Resistivity Calculator Engineering Tool calculates the total conductivity as the sum of three independent conductivity mechanisms: a thermally activated hopping conductivity, a variable range hopping conductivity, and a radiation induced conductivity using a total of nine independent fitting parameters determined from fits to an extensive data set taken by the Utah State University Materials Physics Group. It also provides a fit for …

A System Model For The Effect Of Polarization Mode Dispersion On Digital Modulated Optical Signals In Single Mode Fibers, Abhijit Shriram Chitambar

Doctoral Dissertations

A comprehensive systems model that retains the discrete nature of the output delay distribution in order to accurately characterize the pulse broadening due to Polarization Mode Dispersion (PMD) is developed in this thesis. PMD in optical channels has been a critical factor limiting high-speed data transmission over long distances in optical networks. PMD is a source of Inter Symbol Interference (ISI) and its impact increases with the transmission data rate. Since economical adaptive compensation schemes are currently unavailable, it is essential to characterize this impairment to completely understand its impact and develop effective countermeasures. An incremental approach has been developed …

Biologically Inspired Feature Extraction For Rotation And Scale Tolerant Pattern Analysis, Dragan Vidacic

Doctoral Dissertations

Biologically motivated information processing has been an important area of scientific research for decades. The central topic addressed in this dissertation is utilization of lateral inhibition and more generally, linear networks with recurrent connectivity along with complex-log conformal mapping in machine based implementations of information encoding, feature extraction and pattern recognition. The reasoning behind and method for spatially uniform implementation of inhibitory/excitatory network model in the framework of non-uniform log-polar transform is presented. For the space invariant connectivity model characterized by Topelitz-Block-Toeplitz matrix, the overall network response is obtained without matrix inverse operations providing the connection matrix generating function is …

Using Virtual Laboratories In Control Engineering Education, Aidan O'Dwyer

Level 3

The twin pressures of the need for students to learn a wider variety of concepts, ideally in a self-learning mode, and the reduction in class contact time has led to the use of increased levels of information technology in control engineering education. This paper reports on, reflects on, and evaluates the author’s use of virtual laboratories (computer based laboratories available on the internet) in control engineering modules at DIT Kevin St. The use of the virtual laboratories helps in the ongoing evolution of the teaching approach from a traditional didactic lecture and laboratory course to a more learner-centred approach. The …

Study Of Additives Used In A Copper Via Filling Chemistry, Sheik Ansar Usman Ibrahim

Master's Theses and Capstones

An experimental study on the effect of additives used in a copper via-filling chemistry is carried out by electroanalytical techniques. These include potential or current pulse reversal deposition and cyclic voltammetry methods. Suppression of electrodeposition caused by polyethylene glycol (PEG) and by a commercial suppressor was examined. Effect of bis-(3-sulfopropyl)-disulfide (SPS) and a combination with the suppressor was also examined. A model based on free accelerant complex formation was used to design the experiments. Contrast in the chemical environment between the bottom and the surface of the vias was simulated on a rotating disk electrode (RDE) by variation of rotation …

Assessing Post Treatment Aeration Variables To Reduce Trihalomethanes For Small Systems, Ethan S. Brooke

Master's Theses and Capstones

Small Public Water Systems face unique challenges in meeting Stage I & II disinfection byproduct rules. Diffused and spray aeration offer significant advantages in installation and O&M costs for small communities that need to lower THMs in finished drinking water. In this study, bench and pilot aeration assessments were undertaken in order to evaluate the importance and interaction of aeration variables associated with Trihalomethane (THM) and specifically chloroform removal. Bench scale experiments to determine the effect of air stripping on free chlorine levels and water pH were also conducted.

Assessing Arsenic Removal By Zero Valent Iron Under Various Water Quality And Precoat Filtration Conditions, Paul T. Pepler

Master's Theses and Capstones

Arsenic contamination in drinking water is a world wide public health concern. Previous studies with zero valent iron (ZVI) have indicated its effectiveness in the removal of arsenic from contaminated waters. This study examined a range of water quality conditions to determine the optimal conditions for As removal while minimizing iron dissolution. This information was used to assess the modification of precoat filtration with ZVI for arsenic removal.

ORP exerts a significant influence on arsenic removal with the greatest removals (>99%) occurring at high ORPs and the smallest removals occurring at low ORPs. ZVI amended precoat filtration studies displayed …

Mathematical And Experimental Analysis Of The Steady States In A Simple Microvascular Network System, Ekta Suman

Master's Theses and Capstones

In this paper, a three node network topology with one inlet and two outlets is studied for the existence of the steady state solutions. Both mathematical stimulation and in-vitro experimental methods are studied. The solution for the steady state is found numerically using MATLAB software. The experimental data are studied to verify the stimulation results.

In-vitro experiments are performed on two different diameter (35 micrometers and 50 micrometers) dimension microchannel devices using red blood cells flow. Closing material balance on the feed hematocrit is successfully attained. The results follow the trend of the results obtained from the numerical stimulation. However, …

Auto-Adaptive Multistage Curing Epoxy Coatings, Mathieu Chirat

Master's Theses and Capstones

Corrosion is an expensive issue for the Navy. Epoxy based protective coatings are used by the Navy to minimize corrosion. The goal of this work is to reduce the cost of corrosion by improving the reliability of the coating application. A better application process decreases defects and reduces early failures. A novel hybrid epoxy coating system composed of two layers has been developed. A first layer with two curing stages (an epoxy/amine polycondensation combined with a vinyl free radical polymerization) and a standard second layer were created and tested. A room temperature free radical initiator system was selected to perform …

Investigation Of Radical Entry And Diffusion Within Latex Particles During Emulsion Polymerization, Brian S. Perry

Master's Theses and Capstones

In the field of aqueous based free radical emulsion polymerization, it has been a long-standing belief that a charged polymer chain end group will exclusively anchor to the surface of a polymer particle. This notion is not intuitive for all cases, particularly in the case of an inverted core-shell composite particle where second stage polymer resides within the interior and is surrounded by first stage polymer. This dissertation describes a plethora of polymerizations and subsequent characterization techniques used to determine the location of polymer chain end groups in a series of seeded batch and semi-batch emulsion polymerizations. The analytical results …

Public Interest, Professional Bargains: Ethical Conflicts Between Lawyers And Professional Engineers, Elizabeth J. Hubertz

Scholarship@WashULaw

Environmental experts come from many fields, including biology, geosciences, ecology, chemistry, engineering, social science, and economics. Each discipline has its own set of norms, practices, ethics, guidelines, and procedures, which differ from those of the legal profession. Wherever the disciplines intersect, there is a potential for disagreement. This Article examines one such set of potential clashes — the conflict between a lawyer‘s duties of loyalty and confidentiality, and the engineer‘s paramount duty to the public health, safety, and welfare.

Modeling The Signal Processing Of A Multi-Sonar System To Determine Interference Solutions, Brian O'Donnell

Master's Theses and Capstones

The quality of a multibeam echo-sounder sonar (ES) signal used in seafloor mapping is degraded by an interfering sidescan sonar (SS) signal. The ES and SS signals occur at approximately the same time, are in the same frequency band, and arrive from approximately the same direction. The ES signal is a 2 ms continuous wave pulse with a first null bandwidth of 1 kHz centered at 187.5 kHz. The interfering SS signal is an 8 ms linear frequency modulated chirp with a bandwidth of 2.5 kHz centered at 183 kHz.

The presence and properties of the interfering SS signal are …

Analysis Of Assessment Strategies Used In A Level 7, Year 1 Engineering Subject, Aidan O'Dwyer

Conference papers

This contribution critically analyses the assessment strategies used on the core Electrical Systems subject in the first year of a three-year, Level 7, degree programme in Electrical Engineering at Dublin Institute of Technology. An evidence-based approach is taken, by analysing the assessment data in detail.

A Framework For Temperature Imaging Using The Change In Backscattered Ultrasonic Signals, Yuzheng Guo

All Theses and Dissertations (ETDs)

Hyperthermia is a cancer treatment that elevates tissue temperature to 40 to 43oC. It would benefit from a non-invasive, safe, inexpensive and convenient thermometry to monitor heating patterns. Ultrasound is a modality that meets these requirements. In our initial work, using both prediction and experimental data, we showed that the change in the backscattered energy: CBE) is a potential parameter for TI. CBE, however, was computed in a straightforward yet ad hoc manner. In this work, we developed and exploited a mathematical representation for our approach to TI to optimize temperature accuracy. Non-thermal effects of noise and motion confound the …

Modeling And Identification Of Differentially Regulated Genes Using Transcriptomics And Proteomics Data, Thanura Elvitigala

All Theses and Dissertations (ETDs)

Photosynthetic organisms are complex dynamical systems, showing a remarkable ability to adapt to different environmental conditions for their survival. Mechanisms underlying the coordination between different cellular processes in these organisms are still poorly understood. In this dissertation we utilize various computational and modeling techniques to analyze transcriptomics and proteomics data sets from several photosynthetic organisms. We try to use changes in expression levels of genes to study responses of these organisms to various environmental conditions such as availability of nutrients, concentrations of chemicals in growth media, and temperature. Three specific problems studied here are transcriptomics modifications in photosynthetic organisms under …

Electrocardiographic Consequences Of Electrical And Anatomical Remodeling In Diabetic And Obese Humans, Shuli Wang

All Theses and Dissertations (ETDs)

Background. Diabetes and obesity are two major risk factors for cardiovascular disease. Both can cause changes due to cardiac sources in body-surface potentials: BSPs), that is, in electrocardiograms: ECGs). By identifying the major effects of diabetes and obesity on BSPs, we hope to reveal the electrical phenotype of diabetes in body-surface ECGs in the presence of obesity. Methods. A Bidomain Platform was constructed to link heart-surface transmembrane potentials: TMPs) and BSPs. The Forward-Problem Module of the platform calculates BSPs from a bidomain-model of myocyte TMPs and torso anatomy. The platform also contains a Cardio-myocyte TMP Estimation Module in which an …

Aerosol Filtration And Separation, Tachih Hsiao

All Theses and Dissertations (ETDs)

ABSTRACT OF THE DISSERTATION Aerosol Filtration and Separation by Ta-Chih Hsiao Doctor of Philosophy in Energy, Environmental, & Chemical Engineering Washington University in St. Louis, 2009 Professor Da-Ren Chen, Advisor Particle control technologies are essential in many manufacturing industries: chemical, electronic, mineral, and food and beverages) as well as in pollution abatement and environmental control: for example, clean rooms and post processing of power plant emissions). A variety of particle control technologies using different physical forces and various collection substrates have been developed over the last 100 or so years. Among these technologies, filtration is known as the most economical …

Contributions To The Methodology Of Electrocardiographic Imaging (Ecgi) And Application Of Ecgi To Study Mechanisms Of Atrial Arrhythmia, Post Myocardial Infarction Electrophysiological Substrate, And Ventricular Tachycardia In Patients, Yong Wang

All Theses and Dissertations (ETDs)

ABSTRACT OF THE DISSERTATION Contributions to the Methodology of Electrocardiographic Imaging: ECGI) and Application of ECGI to Study Mechanisms of Atrial Arrhythmia, Post Myocardial Infarction Electrophysiological Substrate, and Ventricular Tachycardia in Patients by Yong Wang Doctor of Philosophy in Biomedical Engineering Washington University in St. Louis, 2009 Professor Yoram Rudy, Chair Electrocardiographic Imaging: ECGI) is a noninvasive imaging modality for cardiac electrophysiology and arrhythmia. ECGI reconstructs epicardial potentials, electrograms and isochrones from body-surface electrocardiograms combined with heart-torso geometry from computed tomography: CT). The application of a new meshless method, the Method of Fundamental Solutions: MFS) is introduced to ECGI with …

Development And Implementation Of Fully 3d Statistical Image Reconstruction Algorithms For Helical Ct And Half-Ring Pet Insert System, Daniel Keesing

All Theses and Dissertations (ETDs)

X-ray computed tomography: CT) and positron emission tomography: PET) have become widely used imaging modalities for screening, diagnosis, and image-guided treatment planning. Along with the increased clinical use are increased demands for high image quality with reduced ionizing radiation dose to the patient. Despite their significantly high computational cost, statistical iterative reconstruction algorithms are known to reconstruct high-quality images from noisy tomographic datasets. The overall goal of this work is to design statistical reconstruction software for clinical x-ray CT scanners, and for a novel PET system that utilizes high-resolution detectors within the field of view of a whole-body PET scanner. …

Electrocorticographic Neural Correlates Of Arm Movements And Associated Goal Orientation In Humans, Nicholas Anderson

All Theses and Dissertations (ETDs)

This thesis analyzed the cortical representation of arm kinematics, target encoding, and goal encoding using subdural electrocorticographic: ECoG) recordings in humans. Using a joystick-based visuomotor task, subjects performed both a standard, delayed match-to-sample center-out task as well as a circular tracing task. Spectral analyses of the ECoG signals clearly showed significant cosine tuning for hand velocity, direction, position and speed throughout the cortex. In particular, velocity tuning was best represented spectrally in a high gamma band from around 90-150 Hz in the primary motor cortical regions. In dorsolateral prefrontal cortex: DLPFC), cortical activity in the 150-250 Hz band of the …

Reconfigurable End Effector Allowing For In-Hand Manipulation Without Finger Gaiting Or Regrasping, Jacob Ames Ziesmer

Master's Theses (2009 -)

The goal of this thesis is to move a step towards the solution of the bin picking problem. A novel metamorphic end effector is proposed, tested for proof of concept and analyzed using standard techniques of degrees of freedom and graph theory as well as a classical dynamic analysis. Once proof of concept was achieved, the results from the analysis were formed into an optimization program with the hope of finding a more stable, predictable mechanism.

2008 Fall Engr333 Project Final Report, 2008 Fall Engr333

ENGR 333

The Calvin College Engineering 333 class of 2008 was challenged with the question, “What would it take to implement an energy efficiency fund at Calvin?” Before addressing this question, another had to be asked: “What is an energy efficiency fund?” An energy efficiency fund is a revolving fund which takes seed money from donations, tuition, or grants and invests it into projects that save energy. Energy cost savings from the projects are routed back to the fund to help it grow and enable it to finance future projects. In order to begin this, the senior engineering students began organizing and …

Competency-Based Curriculum For A Master's Program In Service Science, Management And Engineering (Ssme): An Online Delphi Study, Rahul Choudaha

Electronic Theses and Dissertations

The overarching purpose of this research was to provide theoretical and conceptual foundations for developing a competency-based curriculum for an interdisciplinary master's program in Service Science, Management and Engineering (SSME). Specifically, the objective was to ascertain the competencies and courses that are relevant for developing a competency model for a service scientist and a curriculum blueprint for SSME. The study employed three rounds of the online Delphi survey to achieve the research objectives. The three rounds were used to identify, prioritize, and define competencies and courses. A panel of industry professionals and university faculty were invited to participate as experts. …

A Systematic Approach Towards Developing A Philosophy Of Engineering: Engineers Dancing With Philosophers, Mike Murphy

Presentations

No abstract provided.

Design And Analysis Of A Positively Engaged Continuously Variable Transmission, Brandon Levi Haupt

Theses and Dissertations

With energy demands at an all time high, mechanical power systems are under great scrutiny. Substantial efforts are being made throughout the world to reduce energy use in common mechanical systems such as the internal combustion engine and transmission system. Eliminating or reducing efficiency losses in the transmission is a potential source of improving the efficiency of the system. To do so, various alternative types of transmissions are being investigated. At Brigham Young University, development of a Positively Engaged Continuously Variable Transmission (PECVT) is progressing. In addition to the efficiency increases that would occur as a result of operating the …

Applications Of Combinatorial Designs In Key Pre-Distribution In Sensor Networks., Dibyendu Chakrabarti Dr.

Doctoral Theses

Key pre-distribution is an important area of research in Distributed Sensor Networks (DSN). Some improved techniques over the existing schemes (employing combinatorial designs) have been proposed in this thesis and detailed mathematical analysis of the schemes has been presented. At first, combinatorial design followed by randomized merging strategy is applied to key pre-distribution in sensor nodes. Our main target is to get more than one pair of common keys between any pair of nodes to provide a robust network in terms of security under adversarial conditions where some nodes may get compromised. A transversal design is used to construct a …

2008 Fall Engr333 Project Assignment, Matthew K. Heun

ENGR 333

The Fall 2008 semester ENGR333 project assessed the feasibility of a Green Revolving Fund for Calvin College. I asked the students “What would it take to implement a Calvin Energy Efficiency Fund (CEEF)?”

The project emerged from the work of the previous year’s students who uncovered the concept of green revolving funds.

Immediately after the Fall 2008 semester, I went on sabbatical to South Africa for all of 2009. While I was away, the Calvin administration established the Calvin Energy Recovery Fund (CERF). Over the next decade, CERF saved hundreds of thousands of dollars in energy costs and was …

Deep Sea Underwater Robotic Exploration In The Ice-Covered Arctic Ocean With Auvs, Clayton Kunz, Chris Murphy, Richard Camilli, Hanumant Singh, John Bailey, Ryan M. Eustice, Chris Roman, Michael Jakuba, Claire Willis, Taichi Sato, Ko-Ichi Nakamura, Robert A. Sohn

Graduate School of Oceanography Faculty Publications

The Arctic seafloor remains one of the last unexplored areas on Earth. Exploration of this unique environment using standard remotely operated oceanographic tools has been obstructed by the dense Arctic ice cover. In the summer of 2007 the Arctic Gakkel Vents Expedition (AGAVE) was conducted with the express intention of understanding aspects of the marine biology, chemistry and geology associated with hydrothermal venting on the section of the mid-ocean ridge known as the Gakkel Ridge. Unlike previous research expeditions to the Arctic the focus was on high resolution imaging and sampling of the deep seafloor. To accomplish our goals we …

Bs News

Building Services Engineering

No abstract provided.