Engineering Commons^™

Impact Of A Localized Lean Six Sigma Implementation On Overall Patient Safety And Process Efficiency, Luvianca G. Gil-Moreno

Engineering Management & Systems Engineering Theses & Dissertations

Continuous quality improvement tools have been widely used in the Healthcare Industry to increase efficiency and patient safety as well as to reduce cost. This research explores the impact of a Lean Six Sigma (LSS) process improvement initiative on the overall process efficiency and patient safety in the Labor and Delivery (L+D) units of a large hospital provider. This study focuses on the application of a modeling and simulation methodology to investigate the influence of a localized process improvement intervention on the overall L+D unit output by considering patient flow, system capacity, and unit performance. The simulation models capacity profiles …

Deposition Of Silicon Thin Films By Ion Beam Assisted Deposition, Tejaswini Miryala

Electrical & Computer Engineering Theses & Dissertations

With the depletion of non-renewable energy sources owing to increasing demands, we need to develop renewable energy sources, which can replace them with cleaner energy sources. The solar industry is one of these renewable energies. In spite of having very high potential, harvesting solar energy has been a challenge due to the cost of solar cells. Silicon dominates the photovoltaic industry, but even this technology can accommodate great improvements. This can be done notably by finding low cost deposition techniques for the silicon. The main aim of this thesis is to form high-quality nanocrystalline silicon thin films with the help …

Low Temperature Plasma For The Treatment Of Epithelial Cancer Cells, Soheila Mohades

Electrical & Computer Engineering Theses & Dissertations

Biomedical applications of low temperature plasmas (LTP) may lead to a paradigm shift in treating various diseases by conducting fundamental research on the effects of LTP on cells, tissues, organisms (plants, insects, and microorganisms). This is a rapidly growing interdisciplinary research field that involves engineering, physics, life sciences, and chemistry to find novel solutions for urgent medical needs. Effects of different LTP sources have shown the anti-tumor properties of plasma exposure; however, there are still many unknowns about the interaction of plasma with eukaryotic cells which must be elucidated in order to evaluate the practical potential of plasma in cancer …

Analysis Of Project Management System Structure Using The Viable System Model (Vsm), Joseph A. Sisti

Engineering Management & Systems Engineering Theses & Dissertations

The purpose of this research was to explore the applicability of the Viable System Model as a framework for structural analysis of Project Management Systems using a case study approach. The research used a modified Viable System Model based on the work of Stafford Beer (1979) for the analysis of systems (organizations). The specific research questions explored in this research were: (1) How can the Viable System Model (VSM) be adapted for analysis of project management structure? And, (2) What results from exploration of the Viable System Model framework application to active project management structures?

The research used an exploratory …

Behavior And Strength Of Rc Spandrel Members Under Unsymmetrical Bending And Torsion Including Cfrp Retrofitting, Muhammad Fahim

Civil & Environmental Engineering Theses & Dissertations

This dissertation presents the outcome of an experimental and theoretical investigation of the behavior and strength of reinforced concrete spandrel members both with and without carbon fiber reinforced polymer (CFRP) retrofitting. Both isolated spandrel members with L-shaped cross section as well as those integrated with reinforced concrete slabs are studied. A series of isolated spandrel members were tested under separate and combined actions of unsymmetrical bending and torsion. Six of these specimens were retrofitted externally with high-strength CFRP strips. Materially nonlinear analysis procedures are also formulated and programmed for the spandrel members with and without CFRP retrofitting. Furthermore, ultimate bending-torsion …

Investigation Of Low Cost Substrate Approaches For Iii-V Solar Cells, Marlene Lydia Lichty

Electrical & Computer Engineering Theses & Dissertations

With the need for cleaner energy sources, which can displace fossil fuel, the solar cell industry is of particular interest due to the abundancy of the Sun. Silicon currently dominates terrestrial applications, but efficiency improvements have saturated. III-V based solar cells have reported the highest efficiencies, however, high costs due to substrates and fabrication processes have limited these devices to specialty applications, such as space. In order to reduce the cost associated with fabricating III-V semiconductor substrate material, two different approaches were taken in this work with a particular focus on making III-Vs more applicable outside of specialty applications, including …

A Household Daily Non-Mandatory Activity Participation And Duration Modeling Accounting For Person Level Budget Constraints, Ivana Vukovic

Civil & Environmental Engineering Theses & Dissertations

A key methodological and behavioral innovative component in recent Activity-Based Models (ABMs) used for transportation planning is the household-level non-mandatory activity participation component. While traditional ABMs use a series of simple models to predict non-mandatory activity participation decisions in a sequential manner (which is often not correct), the Multiple Discrete Continuous Extreme Value (MDCEV) model can model both individual and joint non-mandatory activity participation and time allocation decisions in different out-of-home activities of all household members simultaneously. A key advantage of the MDCEV framework is that it accounts for complex intra-household interactions among different household members by allocating the total …

Behavior And Strength Of Non-Prestressed And Prestressed Hillman Composite Beam Including Cfrp Retrofitting, Wajid Khan

Civil & Environmental Engineering Theses & Dissertations

The Hillman Composite Beam (HCB) is a recent innovation used for the first time in 2008 for a bridge construction in USA. It essentially consists of an FRP outer shell, concrete arch inside the shell and steel strands used to tie the two ends of the arch. Being new in the field, the behavior of HCB has not been thoroughly studied. This dissertation presents a study of the flexural behavior and strength of HCB up to the collapse as well as explores the influence of using carbon reinforced polymer (CFRP) retrofitting and prestressed steel for a further increase in HCB …

Modification Of Deposition Process Parameters For Uniform Indium Layer Deposition, Isaac Butt

Electrical & Computer Engineering Theses & Dissertations

The need for more efficient light to energy converting cells has long been a subject of research and development. With abundant availability of solar energy that the earth receives, the photovoltaic industry has sought materials that could serve the purpose of great energy conversion. The photovoltaic industry is mainly dominated by Silicon owing to its abundant availability, reliability and economic cost. However, due to limitations on efficiency improvements, some focus has shifted toward III-V based solar cells with a great potential for attaining higher efficiency and multi-junction applications. However, the cost of the III-V materials is extremely high due to …

A Predictor Analysis Framework For Surface Radiation Budget Reprocessing Using Design Of Experiments, Patricia Allison Quigley

Engineering Management & Systems Engineering Theses & Dissertations

Earth’s Radiation Budget (ERB) is an accounting of all incoming energy from the sun and outgoing energy reflected and radiated to space by earth’s surface and atmosphere. The National Aeronautics and Space Administration (NASA)/Global Energy and Water Cycle Experiment (GEWEX) Surface Radiation Budget (SRB) project produces and archives long-term datasets representative of this energy exchange system on a global scale. The data are comprised of the longwave and shortwave radiative components of the system and is algorithmically derived from satellite and atmospheric assimilation products, and acquired atmospheric data. It is stored as 3-hourly, daily, monthly/3-hourly, and monthly averages of 1°x1° …

Optimal Ship Maintenance Scheduling Under Restricted Conditions And Constrained Resources, Vi Hong Nguyen

Mechanical & Aerospace Engineering Theses & Dissertations

The research presented in this dissertation addresses the application of evolution algorithms, i.e. Genetic Algorithm (GA) and Differential Evolution algorithm (DE) to scheduling problems in the presence of restricted conditions and resource limitations. This research is motivated by the scheduling of engineering design tasks in shop scheduling problems and ship maintenance scheduling problems to minimize total completion time. The thesis consists of two major parts; the first corresponds to the first appended paper and deals with the computational complexity of mixed shop scheduling problems. A modified Genetic algorithm is proposed to solve the problem. Computational experiments, conducted to evaluate its …

Recurrent Neural Networks And Matrix Methods For Cognitive Radio Spectrum Prediction And Security, Alexander M. Glandon

Electrical & Computer Engineering Theses & Dissertations

In this work, machine learning tools, including recurrent neural networks (RNNs), matrix completion, and non-negative matrix factorization (NMF), are used for cognitive radio problems. Specifically addressed are a missing data problem and a blind signal separation problem. A specialized RNN called Cellular Simultaneous Recurrent Network (CSRN), typically used in image processing applications, has been modified. The CRSN performs well for spatial spectrum prediction of radio signals with missing data. An algorithm called soft-impute for matrix completion used together with an RNN performs well for missing data problems in the radio spectrum time-frequency domain. Estimating missing spectrum data can improve cognitive …

An Investigation Into The Potential Benefits Of Distributed Electric Propulsion On Small Uavs At Low Reynolds Numbers, Engin Baris

Mechanical & Aerospace Engineering Theses & Dissertations

Distributed electric propulsion systems benefit from the inherent scale independence of electric propulsion. This property allows the designer to place multiple small electric motors along the wing of an aircraft instead of using a single or several internal combustion motors with gear boxes or other power train components. Aircraft operating at low Reynolds numbers are ideal candidates for benefiting from increased local flow velocities as provided by distributed propulsion systems.

In this study, a distributed electric propulsion system made up of eight motor/propellers was integrated into the leading edge of a small fixed wing-body model to investigate the expected improvements …

A Study Of The Sensitivity Of Energy Conversion Efficiency To Load Variation In Class-E Resonant Power Inverter, Richard Samuel Jennings

Electrical & Computer Engineering Theses & Dissertations

In this thesis the sensitivity of energy conversion efficiency (ECE) and output power of a class-E resonant inverter under variable resistive and inductive load assignments is examined for wireless power transfer (WPT) applications. By performing simulation and mathematical analysis, it was found that the on-resistance of the switching device has minor effect on the design’s efficiency. Additional comparisons between the simulation and mathematical analysis show reasonable output power and ECE load variation performance for the design, but with unique load impedances where zero voltage switching (ZVS) and zero derivative switching (ZDS) are achieved. These comparisons also expose inaccurate mathematical assumptions. …

Planning And Team Shared Mental Models As Predictors Of Team Collaborative Processes, Zikai Zhou

Engineering Management & Systems Engineering Theses & Dissertations

This study evaluates the role of team planning and the similarity of team shared mental models (TSMMs) as predictors of two types of collaborative behaviors that are known to contribute to team performance. A computer-based Networked Fire Chief (NFC) simulation task was used as a testing environment for emergent and dynamic situations. The relationships among team planning, similarity of task-focused team shared mental models (TASKTSMMs), similarity of team-focused team shared mental models (TEAMTSMMs), team backup behaviors, and implicit coordination were tested. This study provides evidence for the mediation effect of similarity of TASKTSMMs between team planning and team backup behaviors, …

Hydrologic Response Caused By Wetland Expansion At Huntley Meadows Park In Hybla Valley, Virginia, Stephen Fraser Stone

OES Theses and Dissertations

The goal of this study was to understand the effects of wetland expansion across a watershed. The 2013 restoration and expansion of the wetlands at Huntley Meadows Park (Fairfax County, VA) performed by Wetland Studies and Solutions, Inc. provided the opportunity to study this process. The 630 ha park contains more than 364 ha of freshwater emergent and freshwater forested wetlands. The restoration and expansion project used a subsurface vinyl-piling dam that impedes groundwater flow leaving the wetland, thus expanding the existing pond and the surrounding wetland.

This study used a network of more than twenty monitoring instruments making observations …

Development Of An Atlas-Based Segmentation Of Cranial Nerves Using Shape-Aware Discrete Deformable Models For Neurosurgical Planning And Simulation, Sharmin Sultana

Computational Modeling & Simulation Engineering Theses & Dissertations

Twelve pairs of cranial nerves arise from the brain or brainstem and control our sensory functions such as vision, hearing, smell and taste as well as several motor functions to the head and neck including facial expressions and eye movement. Often, these cranial nerves are difficult to detect in MRI data, and thus represent problems in neurosurgery planning and simulation, due to their thin anatomical structure, in the face of low imaging resolution as well as image artifacts. As a result, they may be at risk in neurosurgical procedures around the skull base, which might have dire consequences such as …

Role Of Requirements Engineering In Software Project’S Success, Sujatha Alla

Engineering Management & Systems Engineering Theses & Dissertations

Despite considerable time and resources spent on the initiation phase of software projects, discrepancies often exist between formal project documentation, customer requirements, and final project specifications. Such discrepancies in the requirements management process can have a very negative impact on final project outcomes. A Business Requirements Document (BRD) constitutes the formal software requirements documentation, which typically includes stakeholders’ needs and expectations and project scope while providing a clear project roadmap and project plan. According to IEEE standards, a BRD should be a structured document that includes specific elements such as functional and technical requirements while incorporating certain traits such as …

Quantitative Limits On Small Molecule Transport Via The Electropermeome - Measuring And Modeling Single Nanosecond Perturbations, Esin B. Sözer, Zachary A. Levine, P. Thomas Vernier

Bioelectrics Publications

The detailed molecular mechanisms underlying the permeabilization of cell membranes by pulsed electric fields (electroporation) remain obscure despite decades of investigative effort. To advance beyond descriptive schematics to the development of robust, predictive models, empirical parameters in existing models must be replaced with physics- and biology-based terms anchored in experimental observations. We report here absolute values for the uptake of YO-PRO-1, a small-molecule fluorescent indicator of membrane integrity, into cells after a single electric pulse lasting only 6 ns. We correlate these measured values, based on fluorescence microphotometry of hundreds of individual cells, with a diffusion-based geometric analysis of pore-mediated …

Characterization And Analysis Of Real-Time Capillary Convective Pcr Toward Commercialization, Xianbo Qiu, Shiyin Zhang, Lanju Mei, Di Wu, Ke Li, Shengxiang Ge, Xiangzhong Ye, Ningshao Xia, Michael G. Mauk

Mechanical & Aerospace Engineering Faculty Publications

Almost all the reported capillary convective polymerase chain reaction (CCPCR) systems to date are still limited to research use stemming from unresolved issues related to repeatability, reliability, convenience, and sensitivity. To move CCPCR technology forward toward commercialization, a couple of critical strategies and innovations are discussed here. First, single- and dual-end heating strategies are analyzed and compared between each other. Especially, different solutions for dual-end heating are proposed and discussed, and the heat transfer and fluid flow inside the capillary tube with an optimized dual-end heating strategy are analyzed and modeled. Second, real-time CCPCR is implemented with light-emitting diode and …

6 Field-Observed Cracking Of Paired Lightweight And Normalweight Concrete Bridge Decks, Tara L. Cavalline, Jeremy T. Calamusa, Amy M. Kitts, Brett Q. Tempest

Engineering Technology Faculty Publications

Research has suggested that conventional lightweight concrete can offer durability advantages due to reduced cracking tendency. Although a number of publications exist providing the results of laboratory-based studies on the durability performance of lightweight concrete (with lightweight coarse aggregate) and internally cured concrete (using prewetted lightweight fine aggregate), far fewer field studies of durability performance of conventional lightweight concrete bridge decks in service have been performed. This study was commissioned to provide insight to a highway agency on whether enhanced durability performance, and therefore reduced maintenance and longer lifecycles, could be anticipated from existing lightweight concrete bridge decks that were …

Biophysical Tools To Study Cellular Mechanotransduction, Ismeel Muhamed, Farhan Chowdhury, Venkat Maruthamuthu

Mechanical & Aerospace Engineering Faculty Publications

The cell membrane is the interface that volumetrically isolates cellular components from the cell's environment. Proteins embedded within and on the membrane have varied biological functions: reception of external biochemical signals, as membrane channels, amplification and regulation of chemical signals through secondary messenger molecules, controlled exocytosis, endocytosis, phagocytosis, organized recruitment and sequestration of cytosolic complex proteins, cell division processes, organization of the cytoskeleton and more. The membrane's bioelectrical role is enabled by the physiologically controlled release and accumulation of electrochemical potential modulating molecules across the membrane through specialized ion channels (e.g., Na^⁺, Ca²⁺, K^⁺ channels). …

Preface To Special Topic: A Tribute To John Lumley, Kiran Bhaganagar, Thomas B. Gatski, William K. George

CCPO Publications

This Special Topic Section is dedicated to the life and memory of John Leask Lumley(1930-2015), professor and scientist extraordinaire.

Comment On "Roles Of Bulk Viscosity On Rayleigh-Taylor Instability: Non-Equilibrium Thermodynamics Due To Spatio-Temporal Pressure Fronts" Phys. Fluids 28, 094102 (2016), Robert L. Ash

Mechanical & Aerospace Engineering Faculty Publications

No abstract provided.

Data-Driven Spatial Modeling For Quantifying Networkwide Resilience In The Aftermath Of Hurricanes Irene And Sandy, Yuan Zhu, Kun Xie, Kaan Ozbay, Fan Zuo, Hong Yang

Computational Modeling & Simulation Engineering Faculty Publications

In recent years, the New York City metropolitan area was hit by two major hurricanes, Irene and Sandy. These extreme weather events disrupted and devastated the transportation infrastructure, including road and subway networks. As an extension of the authors' recent research on this topic, this study explored the spatial patterns of infrastructure resilience in New York City with the use of taxi and subway ridership data. Neighborhood tabulation areas were used as the units of analysis. The recovery curve of each neighborhood tabulation area was modeled with the logistic function to quantify the resilience of road and subway systems. Moran's …

Controlling The Error On Target Motion Through Real-Time Mesh Adaptation: Applications To Deep Brain Stimulation, Huu Phuoc Bui, Satyendra Tomar, Hadrien Courtecuisse, M. Audette, Stéphane Cotin, Stéphane P.A. Bordas

Computational Modeling & Simulation Engineering Faculty Publications

We present an error-controlled mesh refinement procedure for needle insertion simulation and apply it to the simulation of electrode implantation for deep brain stimulation, including brain shift.

Our approach enables to control the error in the computation of the displacement and stress fields around the needle tip and needle shaft by suitably refining the mesh, whilst maintaining a coarser mesh in other parts of the domain.

We demonstrate through academic and practical examples that our approach increases the accuracy of the displacement and stress fields around the needle without increasing the computational expense. This enables real-time simulations.

The proposed methodology …

Impact Of Connected Vehicles On Mitigating Secondary Crash Risk, Hong Yang, Zhenyu Wang, Kun Xie

Computational Modeling & Simulation Engineering Faculty Publications

Reducing the risk of secondary crashes is a key goal for effective traffic incident management. However, only few countermeasures have been established in practices to achieve the goal. This is mainly due to the stochastic nature of both primary and secondary crashes. Given the emerging connected vehicle (CV) technologies, it is highly likely that CVs will soon be able to communicate with each other through the ad-hoc wireless vehicular network. Information sharing among vehicles is deemed to change traffic operations and allow motorists for more proactive actions. Motorists who receive safety messages can be motivated to approach queues and incident …

The Long Term Effects Of An Aging Fleet On Operational Availability And Cost: Evidence From The Us Coast Guard, Christopher W. Lavin, Robert M. Mcnab, Ryan S. Sullivan

Economics Faculty Publications

This paper empirically examines whether the aging of a fleet affects operational availability and operating cost using a unique data-set on the 117 47-foot Motor Lifeboats (MLBs) of the United States Coast Guard (USCG). Procured from 1997 to 2003, the 47-foot MLB is the standard lifeboat of the USCG and all 117 MLBs remain in service. The aging of the MLB fleet has resulted in higher annual operating costs and lower operational availability, although the nature of this relationship remains unclear. Our estimation strategy utilizes an error components estimator to examine these issues. We employ three variants of the dependent …

Semantic Inference On Clinical Documents: Combining Machine Learning Algorithms With An Inference Engine For Effective Clinical Diagnosis And Treatment, Shuo Yang, Ran Wei, Jingzhi Guo, Lida Xu

Information Technology & Decision Sciences Faculty Publications

Clinical practice calls for reliable diagnosis and optimized treatment. However, human errors in health care remain a severe issue even in industrialized countries. The application of clinical decision support systems (CDSS) casts light on this problem. However, given the great improvement in CDSS over the past several years, challenges to their wide-scale application are still present, including: 1) decision making of CDSS is complicated by the complexity of the data regarding human physiology and pathology, which could render the whole process more time-consuming by loading big data related to patients; and 2) information incompatibility among different health information systems (HIS) …

Qos Recommendation In Cloud Services, Xianrong Zheng, Li Da Xu, Sheng Chai

Information Technology & Decision Sciences Faculty Publications

As cloud computing becomes increasingly popular, cloud providers compete to offer the same or similar services over the Internet. Quality of service (QoS), which describes how well a service is performed, is an important differentiator among functionally equivalent services. It can help a firm to satisfy and win its customers. As a result, how to assist cloud providers to promote their services and cloud consumers to identify services that meet their QoS requirements becomes an important problem. In this paper, we argue for QoS-based cloud service recommendation, and propose a collaborative filtering approach using the Spearman coefficient to recommend cloud …