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Full-Text Articles in Operations Research, Systems Engineering and Industrial Engineering

Characterizing The Effects Of Capillary Flow During Liquid Composite Molding, Michael Ray Morgan Dec 2015

Characterizing The Effects Of Capillary Flow During Liquid Composite Molding, Michael Ray Morgan

Theses and Dissertations

As the aerospace industry continues to incorporate composites into its aircraft, there will be a need for alternative solutions to the current autoclaving process. Liquid composite molding (LCM) has proven to be a promising alternative, producing parts at faster rates and reduced costs while retaining aerospace grade quality. The most important factor of LCM is controlling the resin flow throughout the fiber reinforcement during infusion, as incomplete filling of fibers is a major quality issue as it results in dry spots or voids. Void formation occurs at the resin flow front due to competition between viscous forces and capillary pressure. …


Deriving System Vulnerabilities Using Log Analytics, Matthew Somers Higbee Nov 2015

Deriving System Vulnerabilities Using Log Analytics, Matthew Somers Higbee

Theses and Dissertations

System Administrators use many of the same tactics that are implemented by hackers to validate the security of their systems, such as port scanning and vulnerability scanning. Port scanning is slow, and can be highly inaccurate. After a scan is complete, the results of the scan must be cross checked with a vulnerability database to discover if any vulnerabilities are present. While these techniques are useful, they have severe limitations. System Administrators have full access to all of their machines. They should not have to rely exclusively on port scanning them from the outside of their machines to check for …


Integrating Process Mining With Discrete-Event Simulation Modeling, Siyao Liu Nov 2015

Integrating Process Mining With Discrete-Event Simulation Modeling, Siyao Liu

Theses and Dissertations

Discrete-event simulation (DES) is an invaluable tool which organizations can use to help better understand, diagnose, and optimize their operational processes. Studies have shown that for the typical DES exercise, the greatest amount of time is spent on developing an accurate model of the process that is to be studied. Process mining, a similar field of study, focuses on using historical data stored in software databases to accurate recreate and analyze business processes. Utilizing process mining techniques to help rapidly develop DES models can drastically reduce the amount of time spent building simulation models, which ultimately will enable organizations to …


A Simple Method For Evaluating Wear In Different Grades Of Tooling Applied To Friction Stir Spot Welding, Kirtis Frankland Kennard Jul 2015

A Simple Method For Evaluating Wear In Different Grades Of Tooling Applied To Friction Stir Spot Welding, Kirtis Frankland Kennard

Theses and Dissertations

In this study tools consisting of a 5mm cylindrical pin and a 12mm shoulder held by a simple tool holder were used to compare the wear of 11 tooling materials. The objective was to determine if using these tools in a spot welding configuration to simulate friction stir welding could differentiate the potential performance of tooling materials. All tools were made of varying percentages of polycrystalline cubic boron nitride (PCBN), tungsten (W) and rhenium (Re). The materials are referred to herein as GV1, GV2, G1, G2, G3, G4, G5, G6, G7, G8 and G9.

The tools were run to 205 …


Terminological Mediation In Information Technology And Related Fields, Jessica Smith Richards Jul 2015

Terminological Mediation In Information Technology And Related Fields, Jessica Smith Richards

Theses and Dissertations

Terminological dissonance is created by the inherent ambiguity of natural language and compounded by ontological specialization efforts within fields. Terminological dissonance creates high-risk miscommunications in two key areas: within Information Technology as a singular domain, and also between IT and other fields in interdisciplinary projects. A comprehensive literature review revealed a lack of previous effort to acknowledge or solve problems of terminological dissonance within Information Technology. This research provides a comprehensive overview and definition of the terminology mediation space as it relates to Information Technology and adjacent fields. An analysis and verification of the contents and implementation of the terminology …


Friction Bit Joining Of Dissimilar Combinations Of Dp 980 Steel And Aa 7075, Rebecca Hilary Peterson Jun 2015

Friction Bit Joining Of Dissimilar Combinations Of Dp 980 Steel And Aa 7075, Rebecca Hilary Peterson

Theses and Dissertations

Friction Bit Joining (FBJ) is a new technology that allows lightweight metals to be joined to advanced high-strength steels (AHSS). Joining of dissimilar metals is especially beneficial to the automotive industry because of the desire to use materials such as aluminum and AHSS in order to reduce weight and increase fuel efficiency. In this study, FBJ was used to join 7075 aluminum and DP980 ultra-high-strength steel. FBJ is a two-stage process using a consumable bit. In the first stage, the bit cuts through the top material (aluminum), and in the second stage the bit is friction welded to the base …


Void Modeling In Resin Infusion, Mark Wesley Brandley Jun 2015

Void Modeling In Resin Infusion, Mark Wesley Brandley

Theses and Dissertations

Resin infusion of composite parts has continually been reaching to achieve laminate quality equal to, or exceeding, the quality produced with prepreg in an autoclave. In order for this to occur, developers must understand the key process variables that go in to producing a laminate with minimal void content. The purpose of this research is to continue efforts in understanding 1) the effect of process conditions on the resultant void content, with a focus on resin infusion flow rate, 2) applying statistical metrics to the formation, location and size of voids formed, and 3) correlate these metrics with the local …


Service Dependency Analysis Via Tcp/Udp Port Tracing, John K. Clawson Jun 2015

Service Dependency Analysis Via Tcp/Udp Port Tracing, John K. Clawson

Theses and Dissertations

Enterprise networks are traditionally mapped via layers two or three, providing a view of what devices are connected to different parts of the network infrastructure. A method was developed to map connections at layer four, providing a view of interconnected systems and services instead of network infrastructure. This data was graphed and displayed in a web application. The information proved beneficial in identifying connections between systems or imbalanced clusters when troubleshooting problems with enterprise applications.


Experimental And Numerical Study Of High-Speed Friction Stir Spot Welding Of Advanced High-Strength Steel, Utsab Karki Mar 2015

Experimental And Numerical Study Of High-Speed Friction Stir Spot Welding Of Advanced High-Strength Steel, Utsab Karki

Theses and Dissertations

With the desire to lighten the frame while keeping or increasing the strength, Advanced High-Strength Steels (AHSS) have been developed for use in the automotive industry. AHSS meet many vehicle functional requirements because of their excellent strength and acceptable ductility. But joining AHSS is a challenge, because weldability is lower than that of mild steels. Friction stir spot welding (FSSW) is a solid state joining process that can provide a solution to the weldability issues in AHSS, but FSSW has not been studied in great detail for this application. In this work, Si3N4 tools were used for FSSW experiments on …


The Programmatic Generation Of Discrete-Event Simulation Models From Production Tracking Data, Christopher Rand Smith Mar 2015

The Programmatic Generation Of Discrete-Event Simulation Models From Production Tracking Data, Christopher Rand Smith

Theses and Dissertations

Discrete-event simulation can be a useful tool in analyzing complex system dynamics in various industries. However, it is difficult for entry-level users of discrete-event simulation software to both collect the appropriate data to create a model and to actually generate the base-case simulation model. These difficulties decrease the usefulness of simulation software and limit its application in areas in which it could be potentially useful. This research proposes and evaluates a data collection and analysis methodology that would allow for the programmatic generation of simulation models using production tracking data. It uses data collected from a GPS device that follows …


Compressibility Measurement And Modeling To Optimize Flow Simulation Of Vacuum Infusion Processing For Composite Materials, Paul Hannibal Feb 2015

Compressibility Measurement And Modeling To Optimize Flow Simulation Of Vacuum Infusion Processing For Composite Materials, Paul Hannibal

Theses and Dissertations

Out-of-autoclave manufacturing processes for composite materials are increasing in importance for aerospace and automotive industries. Vacuum Infusion processes are leading the push to move out of the autoclave. An understanding of the various process parameters associated with resin infusion is necessary to produce quality product. Variance in compaction, resin, and vacuum pressures are studied, concentrating on developing a compaction pressure profile as it relates to fiber volume fraction. The purpose of this research is twofold: (1) to show and quantify the existence of a resin pressure gradient in compression testing using rigid tooling, and (2) to use measured test data …