Engineering Commons^™

Toward Automated Detection And Diagnosis Of Mammographic Microcalcifications, Imad Mohammad Zyout

Dissertations

Mammographie diagnosis is the most effective technique to detect breast cancer in its infancy when it is most responsive to treatment. An early and a significant indicator of breast cancer is the presence of clustered microcalcifications (MCs). Mammographie MCs greatly vary in their appearance and shape, and become indistinguishable when surrounded by dense breast tissue. This makes radiologist's interpretation of mammograms a tedious and an error prone task.

Although computer aided diagnosis (CAD) methods are being developed to aid radiologist in detecting and analyzing the malignancy of MCs, existing systems have not achieved a satisfactory performance. The specificity of existing …

Bemdec: An Adaptive And Robust Methodology For Digital Image Feature Extraction, Isaac Kueth Gang

Dissertations

The intriguing study of feature extraction, and edge detection in particular, has, as a result of the increased use of imagery, drawn even more attention not just from the field of computer science but also from a variety of scientific fields. However, various challenges surrounding the formulation of feature extraction operator, particularly of edges, which is capable of satisfying the necessary properties of low probability of error (i.e., failure of marking true edges), accuracy, and consistent response to a single edge, continue to persist. Moreover, it should be pointed out that most of the work in the area of feature …

Design Of Novel Drug Delivery System And Optimal Dosage Regimens, Kwang Seok Kim

Dissertations

Three representative drug delivery systems were analyzed to emphasize the roles of mathematical models and computer-aided simulations in pharmaceutical research. In the first project, a protocol was developed so that the optimal regimen, consisting of the intravenous boluses and subsequent infusion of theophylline, could be obtained once information on the pharmacokinetics became available. The method was based on a two-compartment model of the human body. A module was created and posted on a website for free access. The second project dealt with the transdermal heat-assisted delivery of corticosterone. Heat conduction and drug diffusion through the patch and the skin were …

Atomic And Electronic Structure Studies Of Nano-Structured Systems : Carbon And Related Materials, Sumit Saxena

Dissertations

Modeling in the framework of density functional theory has been conducted on carbon nanotubes and graphene nano-structures. The results have been extended to non-carbon systems such as boron nanostructures. Computational studies are complemented by experimental methods to refine the structural models and obtain a better understanding of the electronic structure.

It is observed that the zigzag edged bilayered graphene nanoribbons are highly unstable as compared to their armchair counterparts. A novel approach has been proposed for the patterning of chirality/diameter controlled single walled carbon nanotubes. Nanotube formation is found to be assisted by edge ripples along with the intrinsic edge …

An Automated Framework For Defect Detection In Concrete Bridge Decks Using Fractals And Independent Component Analysis, Fadi Abu-Amara

Dissertations

Bridge decks deteriorate over time as a result of deicing salts, freezing-andthawing, and heavy use, resulting in internal defects. According to a 2006 study by the American Society of Civil Engineers, 29% of bridges in the United States are considered structurally deficient or functionally obsolete. Ground penetrating radar (GPR) is a promising non-destructive evaluation technique for assessing subsurface conditions of bridge decks. However, the analysis of GPR scans is typically done manually, where the accuracy of the detection process depends on the technician's trained eye. In this work, a framework is developed to automate the detection, localization, and characterization of …

Pattern Recognition For Fault Detection, Classification, And Localization In Electrical Power Systems, Qais Hashim Alsafasfeh

Dissertations

The longer it takes to identify and repair a fault, the more damage may result in the electrical power system, especially in periods of peak loads, which could lead to the collapse of the system, causing the power outage to extend for a longer period and larger parts of the electrical network. Reducing the outage time and immediate restoration of service can be achieved if the fault type and location are determined in a timely and precise manner.

An integrated algorithm that is based on generating unique signatures from the electric current signal to detect, classify, and localize a fault …

Development Of A Task Assignment Tool To Customize Job Descriptions And Close Person-Job Fit Gaps, Bryan W. Booker

Dissertations

Does the knowledge worker fit the job or should the job fit the knowledge worker? This research developed a methodology and a tool to customize a knowledge worker’s job design to better fit their knowledge, skills, abilities and characteristics. The research outcomes support the customization of the job design to improve person-job fit, the documentation of the customized job design as a position description, and the use of a structured person-task assignment process. The recommended task assignment process includes a job aid that uses multivariate equations to predict expected task performance. Data were collected from two knowledge worker sub-groups: lean …

Hardware Support For Real-Time Network Security And Packet Classification Using Field Programmable Gate Arrays, Nitesh Bhicu Guinde

Dissertations

Deep packet inspection and packet classification are the most computationally expensive operations in a Network Intrusion Detection (NID) system. Deep packet inspection involves content matching where the payload of the incoming packets is matched against a set of signatures in the database. Packet classification involves inspection of the packet header fields and is basically a multi-dimensional matching problem. Any matching in software is very slow in comparison to current network speeds. Also, both of these problems need a solution which is scalable and can work at high speeds. Due to the high complexity of these matching problems, only Field-Programmable Gate …

Properties And Device Applications Of Silicon And Silicon-Germanium Nanostructures With Different Dimensions, Han-Yun Chang

Dissertations

Defect-free crystalline Si/SiGe(Ge) nanostructures are demonstrated despite the 4% lattice mismatch between Si and Ge. The lattice mismatch-induced strain is sufficiently relaxed through the designed, cluster morphology, or nanowire (NW) structures. Future device applications of these nano structures require complete understanding of their structural, optical, electrical and thermal properties. This study explores these properties in two-dimensional (2D) Si/Si:B delta-doped multilayers, 2D Si/Si_1-xGe_x planar multilayers, three-dimensional (3D) Si/Si_1-xGe_{x cluster multilayers, one-dimensional (1D) Si NWs and 1D Si/Ge NW heterojunctions (HJs).}

Raman scattering and photoluminescence measurements show that by alternating heavily boron-doped layers with layers of …

The Floating Contract Between Risk-Averse Supply Chain Partners In A Volatile Commodity Price Environment, Mojisola Kike Otegbeye

Dissertations

In this dissertation, two separate but closely related decision making problems in environments of volatile commodity prices are addressed. In the first problem, a risk-averse commodity user's purchasing policy and his risk-neutral supplier's pricing decision, where the user can purchase his needs through contract with his supplier as well as directly from the spot market, are analyzed. The commodity user is assumed to be the supplier's sole client, and the supplier can always expand capacity, at a cost to the user, to accommodate the user's demand in excess of initially reserved capacity.

In the more generalized second problem, both parties …

Novel Micron- And Nano-Scale Energetic Materials For Advanced Gun Propulsion, Their Material Properties, And Their Effects On Ballistic Performance, Thelma Gatuz Manning

Dissertations

This dissertation focused on the investigation of novel materials that are both energetic and inert in their micron- and nano-scale crystalline form. The characterization of the materials properties and its effects on the ballistic performance when incorporated into a composite material were evaluated as a gun propellant for application in a future weapon system for the US Army. Some of these materials may find dual use in civilian applications. Applications in small and medium arms, artillery, tank, aircraft, and shipboard gun systems will all benefit from these advancements. Not only will gun system performance be improved for greater stand-off range …

Constitutive Modeling Of Glassy Memory Polymers, Mahesh Khanolkar

Dissertations

The aim of this research is to develop constitutive models for non-linear materials. Here, issues related for developing constitutive model for glassy shape memory polymers are addressed in detail. Shape memory polymers are novel material that can be easily formed into complex shapes, retaining memory of their original shape even after undergoing large deformations. The temporary shape is stable and return to the original shape is triggered by a suitable mechanism such heating the polymer above a transition temperature. Glassy shape memory polymers are called glassy because the temporary shape is fixed by the formation of a glassy solid, while …

Transport Mechanisms And Modeling Of Riser Reactor, Dawei Wang

Dissertations

Riser reactors are extensively employed in various industrial applications. In a riser reactor, the hydrodynamics is closely interacted with kinetic reactions. Common models for the performance prediction of riser reactors overlook this vital coupling effect, which not only miss the important reaction characteristics in the dense-phase transport regime of riser reactors but also misinterpret the kinetic properties via ad hoc adjustments. It is noted that the modeling of hydrodynamics in riser flows has major flaws in its predictability of phase transport in both dense-phase and accelerating regimes where most reactions occur. In addition, with the spray feeding of reactants at …

Formation Of Screen-Printed Contacts On Multicrystalline Silicon (Mc-Si) Solar Cells, Vishal R. Mehta

Dissertations

Commercial multicrystalline silicon (me-Si) solar cells use screen-printing process for depositing both the Ag paste based gridded front and Al based back (whole area) metal contacts.. This thesis relates to experimental and theoretical studies of contact formation mechanisms in silicon solar cells. Temperature distribution studies during optical processing by. attached thermocouples to cells indicates that the maximum temperature reached under the front silver metal is less. than 800°C; this is lower than the eutectic point of Ag-Si (≈835°C). An analysis of the interaction of Ag particles and Si via the constituents of glass is given. This mechanism leaches metallic ions …

Multi-Component Boron Coatings On Low Carbon Steel Aisi 1018, Naruemon Suwattananont

Dissertations

Boronizing and metalizing are thermo-chemical surface hardening treatments in which boron and metal atoms diffuse into the metal substrate forming metallic boride layers, providing complex properties of B-Me-Fe system.

To study multi-component boron coatings on low carbon steel AISI 1018, the simultaneous powder pack method of boronizing and metalizing was selected to perform the coatings. One B-Fe system and eight boron-metal (B-Me-Fe) systems from transition metals group IVB (Ti, Zr, Hf), group VB (Nb, Ta), and group VIB (Cr, Mo, W) were studied. The system specimens were thermo-chemically treated at 950°C for 4 hours in a crucible containing powder mixture …

Optimizing Integrated Service For A Transit Route With Heterogeneous Demand, Yavuz Yusuf Ulusoy

Dissertations

The methodology developed in this dissertation attempts to optimize integrated service that minimizes the total cost, including user and supplier costs, of a transit route with heterogeneous demand. While minimizing total cost, a set of practical constraints, such as capacity, operable fleet size and frequency conservation, are considered.

The research problem is presented in three scenarios, consisting of various service patterns (e.g., all-stop, short-turn and express) under heterogeneous demand. A logit-based model was used to estimate passenger transfer demand. An exhaustive search method was developed to find the optimal solutions for a simplified transit route with six stops, and a …

Mechanisms For Quality-Of-Service Provisioning In Networks With Extended Services, Zhen Qin

Dissertations

The emerging network traffic with various Quality-of-Service (QoS) requirements creates a demand for QoS service provisioning beyond the best effort service that Internet currently provides. QoS provisioning requires a framework that satisfies users' QoS and cost demand while maximizes benefits for network service providers. It is considered that QoS provisioning involves three issues: a) estimations of the network QoS performance, which can be achieved by performing network measurement; b) dissemination of the measured QoS states throughout the network with states exchanged among different network routers; and c) QoS routing. In this dissertation, these three issues are addressed.

In QoS networks, …

Coupled Simulation Of Loading And Response Of Columns Under Extreme Events, Navid H. Allahverdi

Dissertations

Forces imparted to structural columns during blast-induced loading depends on the shape and size of columns as well as on the intensity of the blast. Column's geometry - i.e., shape and size - influences the flow field around the column and consequently the flow field determines forces experienced by the column The main objective of this research is to estimate the forces imparted to columns in a blast event through studying the air flow field around columns

In this study, the physics of shock wave reflection and rarefaction waves are reviewed with application to describing the air flow around columns …

A Decision Model For Nurse-To-Patient Assignment, Ilgin Acar

Dissertations

A critical consequence of the current nurse shortage in the US may be an increase in the workloads on hospital nurses. Heavy workloads have been identified as a major cause of job dissatisfaction among hospital nurses and may ultimately lead to a reduction in the quality of patient care. A focus on the balancing of the workload among scheduled nurses through patient assignments can help to alleviate the chance of assigning excessive workloads to one or more nurses during a shift. Nurse-to-patient assignment, the final stage of the nurse planning was the main intention of this study. It is reasonable …

Design Of Adaptive Collective Foraging In Swarm Robotic Systems, Hanyi Dai

Dissertations

Inspired by the collective behavior observed in biological colonies, swarm robotics is a new approach to design a distributed control algorithm in order to coordinate a group of simple robots performing a complex group task. With only limited computation and communication ability of individual robots, one of the challenges in designing such multi-robotic systems is to understand the effect of individual robots behavior on the group performance. This thesis dedicates the research to designing a set of local interaction and adaptation rule for individual robots so that optimized collective foraging performance can be achieved at group level.

The research starts …

Modeling The Momentum And Mass Transfer Within A Micro-Scale Polymer Electrolyte Membrane Fuel Cell For Flows Within The Slip Flow Regime, Sean Tamarun Goudy

Dissertations

Polymer Electrolyte Membrane (PEM) fuel cell systems are heterogeneous catalytic systems. Although there are many computational models that describe the behavior of PEM fuel cells, few simulate the catalyst surface concentration of reactant gases at the catalyst layer-membrane layer inteface. Most PEM fuel cell models make no distinction between the bulk concentration of reactants and the catalyst surface concentration of reactants. It is the surface concentration that is key when studying PEM fuel cell systems: the reactions occur at the surface of the catalyst.

In addition, few model the dynamics within the non-continuum flow region near the solid surfaces of …

Optimum Failure Truncated Testing Strategies, Erik Kostandyan

Dissertations

Accumulated fatigue damage on mechanical components due to random stress loads eventually causes failure. Therefore products with lower failure rates are more desirable. Testing mechanical components for their intended purpose under predetermined working conditions is a common practice used by industries to prevent failures. Fatigue tests are categorized as Time Truncated or Failure Truncated, known in the literature as Type I and Type II tests, respectively. In failure truncated tests, the mechanical components are tested until the desired number of results is obtained. The parameters of a typical failure truncated test include the capacity of the test facility, the actual …

Optimizing Green Sand Properties Of Fluidized Sand From Aeration And Developing New Green Sand Testing Technique, Ananda Mani Paudel

Dissertations

Aeration sand filling is a new molding technique in foundry. Using this technique, sand with smooth flow can be filled in any orientation and shape using low-pressure air. This is not possible by conventional gravity and high-pressure blow filling techniques. Aeration was introduced as an energy-efficient and environmentally- friendly sand molding technique. In addition, aeration has its niche on quality of molds it could produce. Friability, one of the crucial green properties for the quality mold was significantly low in aeration in comparison to the gravity and high-pressure blow filling. The fluidization action in aeration acted upon the sand clay …

Target Localization In Mimo Radar Systems, Hana Godrich

Dissertations

MIMO (Multiple-Input Multiple-Output) radar systems employ multiple antennas to transmit multiple waveforms and engage in joint processing of the received echoes from the target. MIMO radar has been receiving increasing attention in recent years from researchers, practitioners, and funding agencies. Elements of MIMO radar have the ability to transmit diverse waveforms ranging from independent to fully correlated. MIMO radar offers a new paradigm for signal processing research. In this dissertation, target localization accuracy performance, attainable by the use of MIMO radar systems, configured with multiple transmit and receive sensors, widely distributed over an area, are studied. The Cramer-Rao lower bound …

Operating Characteristics Of Passenger Screening Processes And The Development Of A Paced Inspection System, Geraldine Kelly Leone

Dissertations

The airport checkpoint security screening (ACSS) system is an important line of defense against the introduction of dangerous objects into the U.S. aviation system. Recently, there has been much interest in modeling these systems and to derive operating parameters which optimize performance. In general there are two performance measures of interest (i) the waiting time of the arriving entities, and (ii) the allocated screening resources and its utilization. Clearly, the traveling public would like a zero waiting time, while airports are limited both in terms of space and resource capital. The arrival and exit entity in the ACSS system are …

Service Oriented Networking For Multimedia Applications In Broadband Wireless Networks, Ehsan Haghani Dogaheh

Dissertations

Extensive efforts have been focused on deploying broadband wireless networks. Providing mobile users with high speed network connectivity will let them run various multimedia applications on their wireless devices. In order to successfully deploy and operate broadband wireless networks, it is crucial to design efficient methods for supporting various services and applications in broadband wireless networks. Moreover, the existing "access-oriented" networking solutions are not able to fully address all the issues of supporting various applications with different quality of service requirements. Thus, "service-oriented" networking has been recently proposed and has gained much attention.

This dissertation discusses the challenges and possible …

Optimal Train Control On Various Track Alignments Considering Speed And Schedule Adherence Constraints, Kitae Kim

Dissertations

The methodology discussed in this dissertation contributes to the field of transit operational control to reduce energy consumption. Due to the recent increase in gasoline cost, a significant number of travelers are shifting from highway modes to public transit, which also induces higher transit energy consumption expenses.

This study presents an approach to optimize train motion regimes for various track alignments, which minimizes total energy consumption subject to allowable travel time, maximum operating speed, and maximum acceleration/deceleration rates. The research problem is structured into four cases which consist of the combinations of track alignments (e.g., single vertical alignment and mixed …

Resource Assignment In Short Life Technology Intensive (Slti) New Product Development (Npd), Randy A. Reagan

Dissertations

Enterprises managing multiple concurrent New Product Development (NPD) projects face significant challenges assigning staff to projects in order to achieve launch schedules that maximize financial returns. The challenge is increased with the class of Short Life Technology Intensive (SLTI) products characterized by technical complexity, short development cycles and short revenue life cycles. Technical complexity drives the need to assign staffing resources of various technical disciplines and skill levels. SLTI products are rapidly developed and launched into stationary market windows where the revenue life cycle is short and decreasing with any time-to-market delay. The SLTI-NPD project management decision is to assign …

Inter-Relationship Of Mechanical And Bio-Chemical Processes Governing The Settlement Of Municipal Solid Waste (Msw) Using The (C +H)/L Ratio, Joseph John Lifrieri

Dissertations

This research discusses the results of experimentation that determines the rates and magnitudes of consolidation and settlement of solid waste materials dependent upon their actual state of biodegradation decomposition and time in place. The state of decomposition of waste is determined by measuring its cellulose plus hemicellulose to lignin ratio ((C + H)/L). The samples were collected from bioreactors, at consecutive time intervals, to simulate states of decomposition.

Each sample was tested in consolidation to determine the value of the primary compression index C' _c, the secondary compression index "the inorganic creep rate" coefficient, C' _α, and the …

End-Of-Life Analysis Of Nanotechnology Products, Sun Olapiriyakul

Dissertations

Previous research has shown that thermodynamic properties including melting point and specific heat capacity of nanomaterials may be higher than that of their corresponding bulk materials. The melting point elevation and specific heat capacity enhancement of nanomaterials may result in increased energy consumption and waste gases emission at the end-of-life (EOL) stage where the products containing nanomaterials are recycled by high temperature metal recovery (HTMR) process.

In this dissertation, the effect of physical characteristics of nanomaterials, referred to as physicochemical parameters, on their melting temperature and specific heat capacity was investigated. In addition, physical, chemical, and thermodynamic properties of nanomaterials …