Engineering Commons^™

Modeling And Analysis Of Social Networks, Robert S. Renfro Ii

Theses and Dissertations

This dissertation develops new methods for the modeling and analysis of social networks. Social networks describe the complex relationships of individuals and groups in multiple overlapping contexts. Influence in a social network impacts behavior and decision making in every setting in which individuals participate. This study defines a methodology for modeling and analyzing this complex behavior using a Flow-Model representation. Multiple objectives in an influencing effort targeted at a social network are modeled using Goal Programming. Value Focused Thinking is applied to model influence and predict decisions based on the reaction of the psychological state of individuals to environmental stimuli. …

The Effect Of Cockpit Noise On Aircraft Pilot Psychomotor Performance, Kelechi (Kc) Nwabeke

Master's Theses - Daytona Beach

The purpose of this study was to evaluate the effect of cockpit noise on aircraft pilot psychomotor performance on a simulated tracking task. The performance of thirty-two participants was measured on a vertical and horizontal tracking task. In the control group, eight participants were used in a quiet condition. In the experimental group, eight participants were exposed to low intensity cockpit noise (50 dBA), eight participants were exposed to medium intensity cockpit noise (60 dBA) and eight participants were expose to high intensity cockpit noise (70 dBA). The performance of the control and experimental groups was measured in an advanced …

Determination Of The Impact Of A Human Capital Decision Cost Model On The Economic Performance Measures Of A Technical Services Company, Jeffery A. Temple

Engineering Management & Systems Engineering Theses & Dissertations

Human Capital has a major impact on cash flow management decisions in a Technical Services company. Decisions to hire or terminate employees to meet contract requirements affect the company's economic value. The objective of this research is to develop a model that assists management in establishing a starting point in making, as efficiently as possible, those decisions that impact employees' lives. To understand that impact, the operations and economic parameters of a Technical Services company are compared with those of a manufacturing company. This analysis establishes two · essential points for Technical Services organizations; first, that the capital investment decision …

A Decomposition Approach For The Multi-Modal, Resource-Constrained, Multi-Project Scheduling Problem With Generalized Precedence And Expediting Resources, Michael L. Fredley

Theses and Dissertations

The field of project scheduling has received a great deal of study for many years with a steady evolution of problem complexity and solution methodologies. As solution methodologies and technologies improve, increasingly complex, real-world problems are addressed, presenting researchers a continuing challenge to find ever more effective means for approaching project scheduling. This dissertation introduces a project scheduling problem which is applicable across a broad spectrum of real-world situations. The problem is based on the well-known Resource-Constrained Project Scheduling Problem, extended to include multiple modes, generalized precedence, and expediting resources. The problem is further extended to include multiple projects which …

Theater-Level Stochastic Air-To-Air Engagement Modeling Via Event Occurrence Networks Using Piecewise Polynomial Approximation, David R. Denhard

Theses and Dissertations

This dissertation investigates a stochastic network formulation termed an event occurrence network (EON). EONs are graphical representations of the superposition of several terminating counting processes. An EON arc represents the occurrence of an event from a group of (sequential) events before the occurrence of events from other event groupings. Events between groups occur independently, but events within a group occur sequentially. A set of arcs leaving a node is a set of competing events, which are probabilistically resolved by order relations. An important EON metric is the probability of being at a particular node or set of nodes at time …

The Effects Of Sound Cue Characteristics On Overcoming Front/Back Localization Errors In A 3-D Auditory Display, Robert J. Ehmann

Master's Theses - Daytona Beach

The purpose of this study was to investigate the performance effects of adding an additional sound cue characteristic to a 3-D auditory display sound stimulus to increase localization accuracy. Previous literature has provided evidence that localization accuracy for direct front and direct back regions is significantly worse than that of locations in the periphery for virtual 3-D auditory stimuli. In the study conducted, a highpass filter addition or a lowpass filter addition was compared to a "normal" condition for both the front and back locations. Results of the study showed that the best localization performance for the front location occurred …

Effects Of Handedness On Completion Time During Performance Of Multiple Tasks Using “Proper” And “Improper” Tools, Lisnnette M. Nieves Suarez

Master's Theses - Daytona Beach

Handedness is a very critical factor involving single or multiple tasks that are designed for a specific hand. The purpose of this research was to investigate the effect of proper tool design. This research identified the dominant hand and measured task completion time between each of two tasks, 1) the use of left and right-handed scissors using the right hand, and 2) Mouse Manipulation Task using the calculator provided by the computer with a left and right-handed mouse using the right hand. Annett’s (1995) 12-item questionnaire was used to identify the preferred hand. This questionnaire consisted of having the participants …

Effect Of Tactile Feedback On Performance, Darren Paul Wilson

Master's Theses - Daytona Beach

Humans interact with their environment by obtaining information from various modalities of sensing. These various modalities of sensing combine to facilitate manipulation and interaction with objects and the environment. The way humans interact with computers mirrors this environmental interaction with the absence of feedback from the tactile channel. The majority of computer operation is completed visually because currently, the primary feedback humans receive from computers is through the eyes. This strong dependence on the visual modality can cause visual fatigue and fixation on displays, resulting in errors and a decrease in performance. Distributing tasks and information across sensory modalities could …

Simulation Optimization Studies Of Routing And Process Flow Problems, Satish Ravichandran

Electrical & Computer Engineering Theses & Dissertations

Computer aided simulation is emerging as a powerful tool for numerical analysis and in conducting performance evaluations of complex systems that depend on a multitude of variables. The primary objective in such simulation studies is to gauge the performance of the system under a various constraints and operating conditions. The effects of changing the operating parameter space can thus be analyzed without having to implement costly changes. Simulations are also carried out for the baseline scenarios to verity and validate the basic underlying system model. In this thesis research, two practical problems were studied through numerical modeling, and optimized solutions …

A Conceptual Framework Of Cost/Benefit Justification For Ergonomic Projects To Reduce Musculoskeletal Disorders In The Workplace, Nitipong Boon-Long

Dissertations

A framework for justifying ergonomic projects to the overall cost savings is developed which estimates the extent of musculoskeletal disorders (MSDs) exposures to a specific industry. A cost structure is developed to estimate the investment needed for an ergonomics program and the costs related to MSDs problems including workers' compensation costs, work-related costs, and labor turnover costs. Data was adopted from sources including Bureau of Labor Statistics (BLS), the Healthcare Cost and Utilization Project (HCUP-3), and estimates suggested in OSHA's former Ergonomics Standard. Top fifteen manufacturing industries with the highest MSDs rates were selected to apply the framework. Results showed …

Designing Web-Based Adaptive Learning Environment : Distils As An Example, Lilian Cao

Dissertations

In this study, two components are developed for the Web-based adaptive learning: an online Intelligent Tutoring Tool (ITT) and an Adaptive Lecture Guidance (ALG). The ITT provides students timely problem-solving help in a dynamic Web environment. The ALG prevents students from being disoriented when a new domain is presented using Web technology. A prototype, Distributed Intelligent Learning System (DISTILS), has been implemented in a general chemistry laboratory domain.

In DISTILS, students interact with the ITT through a Web browser. When a student selects a problem, the problem is formatted and displayed in the user interface for the student to solve. …

Simulation Modeling For Integrated E-Supply Chain Management, Pornsarun Wirojanagud

Theses

E-supply chain management is an emerging area of interest as companies begin to explore the Internet's potential to restructure supply chain relationships. The environmental impact of e-supply chain management is a critical issue towards sustainability. This thesis discusses and models an integrated e-supply chain network accounting for material and information flows throughout the supply chain in order to analyze the environmental implications and tradeoffis with other system characteristics. The network structure has complex interactions between various entities. In order to understand and analyze dynamic performance, a discrete-event simulation approach is utilized. An integrated tool was developed using the Arena simulation …

A Novel Approach Towards Usability Studies For Visual Search Tasks In Graphical User Interface Applications Using The Activity Theory Approach, Tirthankar Sengupta

Theses

The field of Human Computer Interaction still strives for a generalized model of visual search tasks (icon search, menu search, text search, label search, search through hypertext and feature recognition). The existing models of visual search, in spite of being impressive, are limited under certain perspectives due to lack of generality. The thesis tries to provide a holistic approach for the modeling of visual search tasks in graphical user interfaces from the Activity Theory (AT) perspective with the aim of rendering a theoretical bridge between HCI and Psychology. A detailed review of literature from the variegated discipline contributing to the …

Maximum Acceptable Oral Reading Speed For Voice Input Systems, Nirari M. Oda

Masters Theses

The objective of this thesis was to study the effect of vocal duration period and background noise on psychophysical oral reading speed. Ten healthy white males (21-28 years old) were used as subjects. Experiment one was designed to determine Maximum Acceptable Oral Reading Speed (MAORS) for an 8-hour period using psychophysical methodology. Results indicate that 114 words/min was an acceptable oral reading rate for an 8-hour day. Furthermore, 2 hours and 20 minutes is an acceptable testing period ( equivalent to the 8-hour day). Acoustical and physiological variables support these findings. Experiment two was designed to study the effect of …

Study Of Automotive Hydromount Mechanism, Min Lu

Dissertations

The hydromount mechanism is studied. It was determined that the dynamic characteristics of the hydromounts are related to the rubber static stiffness, rubber damping coefficient, volumetric stiffness, and effectiveness of the oscillating fluid in the inertia track. At high frequencies the motion of the fluid in the inertia track diminishes so that its effect is negligible and may be ignored. It is also concluded that the rubber damping has a minimal effect on the hydromount dynamic properties and may be neglected. The maximum loss angle, which corresponds to the maximum damping coefficient of the hydromount, occurs near the inertia track …

Relating Initial Budget To Program Growth With Rayleigh And Weibull Models, Eric J. Unger

Theses and Dissertations

Previous research on completed defense R&D shows that contract expenditures can be fit well with a Rayleigh model. With fixed outlay rates, as prescribed by the OSD comptroller, the budget profile must have most of the funds in the early years to produce Rayleigh-distributed expenditures. R&D programs with more delayed funding profiles may also produce expenditures that a Rayleigh model fits through schedule slips and cost overruns. This research tests how well the initial funding profile produces Rayleigh-distributed expenditures that can be related to the program's final cost overrun and schedule slips. Based only on the initial budget profile, we …

A Delphi Assessment Of The Digital Rosetta Stone Model, Don M. Kelley

Theses and Dissertations

Information that is stored digitally can only be used if it can be retrieved and interpreted. if the methods to retrieve the information are lost, it may be difficult, if not impossible, to recreate them. The knowledge to interpret the bitstream is also at risk. The Digital Rosetta Stone (DRS) Model was developed as a framework for capturing and maintaining the methods necessary to retrieve and display digital information stored on obsolete media or using obsolete software. However, this conceptual model had not yet been assessed by the community of professionals for its practical efficacy. This thesis began the assessment …

Malicious Hackers: A Framework For Analysis And Case Study, Laura J. Kleen

Theses and Dissertations

Recent years have seen an increase in the number and severity of Information Operations (IO) attacks upon DoD resources. At a higher level, the US as a whole has come under cyber attack by individuals and groups seeking thrills, monetary gain, publicity for their causes, and myriad other goals. This effort develops a first cut model of individual hacker mentality that can be utilized to improve threat assessment, mitigate Information Assurance (IA) vulnerabilities, and improve risk assessment. Further, it is a first step toward automated characterization of Information Warfare (IW) attacks based upon hacker types. All hackers are not the …

Using Statistical Process Control Methods To Classify Pilot Mental Workload, Terence Y. Kudo

Theses and Dissertations

The problem of classifying pilot mental workload is important to the United States Air Force. Pilots are more subject to errors and G-induced loss of consciousness during periods of mental overload and task saturation. Often the result is the loss of aircraft, and in extreme cases, the loss of the pilot's life. Current research efforts use different psychophysiological features to classify pilot mental workload. These include cardiac, ocular, respiratory, and brain activity measures. The focus of this effort is to apply statistical process control methodology on different psychophysiological features in an attempt to classify pilot mental workload. The control charts …

Identifying Demand Indicators For Air Force Recruiting Service With Discriminant Analysis, Jason L. Williams

Theses and Dissertations

A changing public disposition towards military service has all four military branches rethinking recruiting practices. This Air Force is reacting to this new recruiting climate by increasing the bonuses for new recruits, pumping up advertising budgets, and bolstering recruiting personnel levels. This thesis provides a new tool for assessing how to allocate these new resources. Discriminant Analysis is used to identify population characteristics that categorize recruiting locations. A methodology is constructed that can discriminate between communities where interest is high in military service and where recruiting efforts will not be productive.

A Multi-Objective Decision Support Model For The Turkish Armed Forces Personnel Assignment System, Zubeyir Cimen

Theses and Dissertations

The Turkish Armed Forces (TAF) assign more than 25,000 active duty personnel annually. TAF wants to obtain maximum utilization of its personnel by assigning the right person to the right job at the right time, To accomplish this task, decision-makers and personnel assignment staff should consider conflicting multiple objectives that create the widely known problem called "personnel assignment problem". To assist in this complicated task from a quantitative perspective, a preemptive goal programming approach was used to develop an integer programming (IP) model to capture the multiple objectives flexibly and interactively. A realistic size IP problem with random data was …

The Effects Of Budgetary Constraints, Multiple Strategy Selection, And Rationality On Equilibrium Attainment In An Information Warfare Simulation, Steven W. Tait

Theses and Dissertations

Information warfare (IW) has developed into a significant threat to the national security of the United States. Our critical infrastructures, linked together by information systems, are increasingly vulnerable to information attack. This study seeks to understand some of those factors which affect the ability of an individual to make accurate decisions in an IW environment. The study used game theory to analyze the behavior of decision-makers within an IW simulation. The IW game model is based on a set of games known as infinitely repeated games of incomplete information. It uses the Bayesian Nash equilibrium concept to determine the strategy …

Robust Multi-Scenario Optimization Of An Air Expeditionary Force Structure Applying Scatter Search To The Combat Forces Assessment Model, Gokay Bulut

Theses and Dissertations

Modern Times' bring change in all areas of life. Even the rate of change has changed, and is still changing to increase it's enormous speed even more. Newer and more challenging questions face the military analysts everyday putting a question mark at the end of their last answer. Recently, the question of how to structure a robust air force to meet the requirements of competing, uncertain future scenarios has been keeping them busy. The new world order does not tolerate only being able to respond to a single scenario anymore, which once was considered a hard problem. Who knows what …

Utility Of Experimental Design In Automatic Target Recognition Performance Evaluation, James M. Higdon

Theses and Dissertations

This research investigates current practices in test and evaluation of classification algorithms, and recommends improvements. We scrutinize the evaluation of automatic target recognition algorithms and rationalize the potential for improvements in the accepted methodology. We propose improvements through the use of an experimental design approach to testing. We demonstrate the benefits of improvements by simulating algorithm performance data and using both methodologies to generate evaluation results. The simulated data is varied to test the sensitivity of the benefits to a broad set of outcomes. The opportunities for improvement are threefold. First, the current practice of 'one-at-a-time factor variation (only one …

Identification Of Critical Roles Of Program Managers And Contracting Officers, Daniel R. Shingledecker

Theses and Dissertations

The purpose of this research was to identify current disagreement among acquisition professionals in regards to their role and authority; and to identify benefits and risks associated with combining program management and contracting officer roles into a single position. The research questions were answered through a literature review and use of the Delphi technique. The literature review indicated that the DoD has been operating with multiple conflicting perceptions of authority among its key acquisition professionals. The literature also identified the need for complex organizations, such as DoD acquisition offices, to pair high levels of responsibility with equally high levels of …

A Verification And Validation Assessment Of Rapid Availability Prototyping For Testing Operational Readiness, Gurhan Tarman

Theses and Dissertations

Throughout the world, new techniques are developed to test and evaluate systems. The Department of Defense and the US Air Force conduct numerous studies into the reliability and maintainability of current and future weapons systems in an effort to understand the reliability, maintainability, and availability (RM&A) costs of these systems. Furthermore, they must verify RM&A characteristics of systems, which are still in the development phase. The Air Force Operational Test and Evaluation Center (AFOTEC) is responsible for testing new equipment to ensure their RM&A characteristics meet specifications. Rapid Availability Prototyping for Testing Operational Readiness (RAPTOR) is the software tool developed …

A Reactive Tabu Search Metaheuristic Extension Of The Air Refueling Tanker Assignment Problem, Umit Hilmi Tekelioglu

Theses and Dissertations

The Combined Mating and Ranging Planning System (CMARPS) is the system used by AMC to schedule air refueling for deployments from the continental U.S. to other parts of the world. The tool developed by Capehart (2000) got results similar to CMARPS in less time. Capehart's tool allows AMC to input several receiver groups consisting of various aircraft types and numbers. Each receiver group contains a point of origin and destination, with the option of providing one waypoint along the path, a ready to load date (RLD) and required delivery date (RDD). The user is also able to specify the locations …

Minimum Distance Estimation For Time Series Analysis With Little Data, Hakan Tekin

Theses and Dissertations

Minimum distance estimate is a statistical parameter estimate technique that selects model parameters that minimize a good-of-fit statistic. Minimum distance estimation has been demonstrated better standard approaches, including maximum likelihood estimators and least squares, in estimating statistical distribution parameters with very small data sets. This research applies minimum distance estimation to the task of making time series predictions with very few historical observations. In a Monte Carlo analysis, we test a variety of distance measures and report the results based on many different criteria. Our analysis tests the robustness of the approach by testing its ability to make predictions when …

An Analysis Of Total System Performance Responsibility In Air Force Acquisitions, Christopher P. White

Theses and Dissertations

This research examined how well the goals and objectives of total system performance responsibility (TSPR) are being met. The research was sparked by the rise of implementing TSPR as an element of an acquisition strategy in many weapon and information systems. Acquisition professionals use TSPR to decrease total ownership cost, improve system performance, and optimize public-private support capabilities while maintaining operational flexibility. However, while the number of programs that use or plan to implement TSPR or some form of contractor support and sustainment continues to increase, little research has been conducted concerning the effectiveness of TSPR as an element of …

Technology Selection For Enhancing F-16 Capability: An Analysis Using Value Focused Thinking, Cihangir Yay

Theses and Dissertations

This study, with support of the Aeronautical Systems center, builds a scientific decision support system intended for Air Combat Command. Past decision-making techniques are discussed and their limitations are explained. Two multiattribute decision-making techniques, analytical hierarch process and value focused thinking, are studied. Due to limitations of analytical hierarchy process, value focused thinking is accepted as the best fit for our problem. A value hierarchy model is developed using value focused thinking for selecting the most beneficiary F-16 engine modifications depending on Air Combat Command values. Ten modifications are ranked using value model to validate the process. Cost is involved …