Operations Research, Systems Engineering and Industrial Engineering Commons^™

Digital Twin-Based Cooperative Control Techniques For Secure And Intelligent Operation Of Distributed Microgrids, Ahmed Aly Saad Ahmed

FIU Electronic Theses and Dissertations

Networked microgrids play a key role in constructing future active distribution networks for providing the power system with resiliency and reliability against catastrophic physical and cyber incidents. Motivated by the increasing penetration of renewable resources and energy storage systems in the distribution grids, utility companies are encouraged to unleash the capabilities of the distributed microgrid to work as virtual power plants that can support the power systems. The microgrids nature is transforming the grid and their control systems from centralized architecture into distributed architectures. The distributed networked microgrids introduced many benefits to the future smart grids, it created many challenges …

Structural Health Monitoring Of Pipelines In Radioactive Environments Through Acoustic Sensing And Machine Learning, Michael Thompson

FIU Electronic Theses and Dissertations

Structural health monitoring (SHM) comprises multiple methodologies for the detection and characterization of stress, damage, and aberrations in engineering structures and equipment. Although, standard commercial engineering operations may freely adopt new technology into everyday operations, the nuclear industry is slowed down by tight governmental regulations and extremely harsh environments. This work aims to investigate and evaluate different sensor systems for real-time structural health monitoring of piping systems and develop a novel machine learning model to detect anomalies from the sensor data. The novelty of the current work lies in the development of an LSTM-autoencoder neural network to automate anomaly detection …

Online Coordination Mechanism For Road Infrastructure Restoration Using Unmanned Aerial Vehicles, Mohammad Amin Farzaneh

FIU Electronic Theses and Dissertations

The goal of this thesis is to study two barriers of efficient road network restoration, namely, the lack of debris information and the lack of coordination among the restoration operations. We develop an integrative online optimization model with a model-based data diffusion component to coordinate three restoration-interdependent operations in the disaster response phases such as damage assessment, road recovery, and relief distribution. The model developed for the damage assessment operation controls the debris data diffusion speed in the integrative framework. This data is periodically shared with an online model developed to prioritize the recovery process for blocked roads. Road prioritization …

A Mathematical Framework On Machine Learning: Theory And Application, Bin Shi

FIU Electronic Theses and Dissertations

The dissertation addresses the research topics of machine learning outlined below. We developed the theory about traditional first-order algorithms from convex opti- mization and provide new insights in nonconvex objective functions from machine learning. Based on the theory analysis, we designed and developed new algorithms to overcome the difficulty of nonconvex objective and to accelerate the speed to obtain the desired result. In this thesis, we answer the two questions: (1) How to design a step size for gradient descent with random initialization? (2) Can we accelerate the current convex optimization algorithms and improve them into nonconvex objective? For application, …

A System-Of-Systems Framework For Assessment Of Resilience In Complex Construction Projects, Jin Zhu

FIU Electronic Theses and Dissertations

Uncertainty is a major reason of low efficiency in construction projects. Traditional approaches in dealing with uncertainty in projects focus on risk identification, mitigation, and transfer. These risk-based approaches may protect projects from identified risks. However, they cannot ensure the success of projects in environments with deep uncertainty. Hence, there is a need for a paradigm shift from risk-based to resilience-based approaches. A resilience-based approach focuses on enhancing project resilience as a capability to cope with known and unknown uncertainty. The objective of this research is to fill the knowledge gap and create the theory of resilience in the context …

A Multi-Criteria Gis-Based Route Selection Tool For Hazardous Material Transport: Consideration Of Environmental Consequence, Traffic Congestions And Costs, Bahareh Inanloo

FIU Electronic Theses and Dissertations

Hazardous materials are substances that, if not regulated, can pose a threat to human populations and their environmental health, safety or property when transported in commerce. About 1.5 million tons of hazardous material shipments are transported by truck in the US annually, with a steady increase of approximately 5% per year.

The objective of this study was to develop a routing tool for hazardous material transport in order to facilitate reduced environmental impacts and less transportation difficulties, yet would also find paths that were still compelling for the shipping carriers as a matter of trucking cost. The study started with …

An Assessment Of The Performances Of Several Univariate Tests Of Normality, James Olusegun Adefisoye

FIU Electronic Theses and Dissertations

The importance of checking the normality assumption in most statistical procedures especially parametric tests cannot be over emphasized as the validity of the inferences drawn from such procedures usually depend on the validity of this assumption. Numerous methods have been proposed by different authors over the years, some popular and frequently used, others, not so much. This study addresses the performance of eighteen of the available tests for different sample sizes, significance levels, and for a number of symmetric and asymmetric distributions by conducting a Monte-Carlo simulation. The results showed that considerable power is not achieved for symmetric distributions when …

Variable Speed Limit Strategies To Reduce The Impacts Of Traffic Flow Breakdown At Recurrent Freeway Bottlenecks, Ali Darroudi

FIU Electronic Theses and Dissertations

Variable Speed Limit (VSL) strategies identify and disseminate dynamic speed limits that are determined to be appropriate based on prevailing traffic conditions, road surface conditions, and weather conditions. This dissertation develops and evaluates a shockwave-based VSL system that uses a heuristic switching logic-based controller with specified thresholds of prevailing traffic flow conditions. The system aims to improve operations and mobility at critical bottlenecks. Before traffic breakdown occurrence, the proposed VSL’s goal is to prevent or postpone breakdown by decreasing the inflow and achieving uniform distribution in speed and flow. After breakdown occurrence, the VSL system aims to dampen traffic congestion …

A Total Quality Management Methodology For Universities, Jose C. Flores-Molina

FIU Electronic Theses and Dissertations

This research document is motivated by the need for a systemic, efficient quality improvement methodology at universities. There exists no methodology designed for a total quality management (TQM) program in a university. The main objective of this study is to develop a TQM Methodology that enables a university to efficiently develop an integral total quality improvement (TQM) Plan.

Current research focuses on the need of improving the quality of universities, the study of the perceived best quality universities, and the measurement of the quality of universities through rankings. There is no evidence of research on how to plan for an …

Analytical Approximations To Predict Performance Measures Of Manufacturing Systems With Job Failures And Parallel Processing, Maria Hulett

FIU Electronic Theses and Dissertations

Parallel processing is prevalent in many manufacturing and service systems. Many manufactured products are built and assembled from several components fabricated in parallel lines. An example of this manufacturing system configuration is observed at a manufacturing facility equipped to assemble and test web servers. Characteristics of a typical web server assembly line are: multiple products, job circulation, and paralleling processing. The primary objective of this research was to develop analytical approximations to predict performance measures of manufacturing systems with job failures and parallel processing. The analytical formulations extend previous queueing models used in assembly manufacturing systems in that they can …

A Capability Maturity Model To Assess Supply Chain Performance, Heriberto Garcia

FIU Electronic Theses and Dissertations

In an overcapacity world, where the customers can choose from many similar products to satisfy their needs, enterprises are looking for new approaches and tools that can help them not only to maintain, but also to increase their competitive edge. Innovation, flexibility, quality, and service excellence are required to, at the very least, survive the on-going transition that industry is experiencing from mass production to mass customization. In order to help these enterprises, this research develops a Supply Chain Capability Maturity Model named S(CM)2. The Supply Chain Capability Maturity Model is intended to model, analyze, and improve the supply chain …

A Definition And Measure Of Workflow Modularity, Dawn-Marie Chin

FIU Electronic Theses and Dissertations

The purpose of this study is to define and measure workflow modularity. There is an increasing need for organizations to implement processes that can be easily configured to offer distinctive capabilities compared to the competition. The concept of modularity provides the foundation for organizations to design flexible processes.

The Event-Driven Process Chain (EPC) approach is used to model an example workflow to illustrate. Based on the model of atomic tasks, rules are developed to guide the creation of modules with high cohesion between tasks in a module and loose-coupling between modules. Matrices of atomic tasks interdependencies are developed and tasks …

Information Model For Engineering Change Management, Clifford L. Panokarren

FIU Electronic Theses and Dissertations

Managing engineering changes is a critical task for organizations to remain competitive. In a manufacturing organization there are innumerable engineering change requests. This thesis is focused on the development of an information model that defines the engineering change process.

This research developed an activity model in IDEF0, an object model in IDEF1X and a dynamic model using state diagrams. The activity model captures the business process for executing an engineering change in terms of its constituting activities and sub-activities. The object model defines each object and its attributes identified in the activity model. The dynamic model captures the status change …

Using Neural Networks For Goal Driven Simulation, Maria F. Clavijo

FIU Electronic Theses and Dissertations

An integration framework for Neural Networks (NN) and Goal Driven Simulation (GDS) has been designed. It offers no constraints regarding number of variables (n>3) and it does not have domain restrictions. The effectiveness of the framework was tested by observing the computational time required for obtaining responses and for training, and by assessing its accuracy for different scenarios. This framework has achieved the automation objective set by GDS under a shorter time frame, as it reduces the time from more than 42 hours to less than 14. A trained NN generates responses to queries almost instantaneously. However, it requires …

The Effects Of Semantic And Syntactic Instruction On User Performance And Satisfaction In Search User Interface Design, Jennifer M. Bandos

FIU Electronic Theses and Dissertations

The design of interfaces to facilitate user search has become critical for search engines, ecommerce
sites, and intranets. This study investigated the use of targeted instructional hints to improve search by measuring the quantitative effects of users' performance and satisfaction.

The effects of syntactic, semantic and exemplar search hints on user behavior were evaluated in an empirical investigation using naturalistic scenarios. Combining the three search hint components, each with two levels of intensity, in a factorial design generated eight search engine interfaces. Eighty participants participated in the study and each completed six realistic search tasks.

Results revealed that the inclusion …

A Heuristic Algorithm To Generate Test Program Sequences For Moving Probe Electronic Test Equipment, Bertha M. Arteta

FIU Electronic Theses and Dissertations

The electronics industry, is experiencing two trends one of which is the drive towards miniaturization of electronic products. The in-circuit testing predominantly used for continuity testing of printed circuit boards (PCB) can no longer meet the demands of smaller size circuits. This has lead to the development of moving probe testing equipment. Moving Probe Test opens up the opportunity to test PCBs where the test points are on a small pitch (distance between points). However, since the test uses probes that move sequentially to perform the test, the total test time is much greater than traditional in-circuit test. While significant …

A Simulation-Based Heuristic For Fleet Assignment, Sonia Rosario Anorga

FIU Electronic Theses and Dissertations

Integer programming, simulation, and rules of thumb have been integrated to develop a simulation-based heuristic for short-term assignment of fleet in the car rental industry. It generates a plan for car movements, and a set of booking limits to produce high revenue for a given planning horizon.

Three different scenarios were used to validate the heuristic. The heuristic's mean revenue was significant higher than the historical ones, in all three scenarios. Time to run the heuristic for each experiment was within the time limits of three hours set for the decision making process even though it is not fully automated. …

Predicting Employee Compliance With Safety Regulations, Factoring Risk Perception, Yenny Farinas Diaz

FIU Electronic Theses and Dissertations

The purpose of this research was to develop a methodology that would evaluate employees’ personality traits, demographic characteristics, and workplace parameters to predict safety compliance along with the moderating effect of risk perception.

One hundred and twenty five employees of a manufacturing facility were given questionnaires to gather their demographic and perception information. Surveys were also used to measure their personality characteristics, and periodic observations were recorded to document employee’s safety compliance. A significant correlation was found between compliance and the worker's perception of management's commitment to safety (r = 0.27, p < 0.01), as well as with gender (r = -0.19, p < 0.05). Females showed a significantly higher average compliance (78%), than males (69%). These findings demonstrated the value of developing a model to predict safety behavior that would assist companies In maintaining a safe work environment, preventing accidents, ensuring compliance, and reducing associated costs.

A Simulation-Based Decision Support System For Evaluating Operating Policies In An Emergency Room Facility, Adriana M. Alvarez

FIU Electronic Theses and Dissertations

Increased pressure to control costs and increased competition has prompted health care managers to look for tools to effectively operate their institutions. This research sought a framework for the development of a Simulation-Based Decision Support System (SB-DSS) to evaluate operating policies. A prototype of this SB-DSS was developed. It incorporates a simulation model that uses real or simulated data. ER decisions have been categorized and, for each one, an implementation plan has been devised. Several issues of integrating heterogeneous tools have been addressed. The prototype revealed that simulation can truly be used in this environment in a timely fashion because …

Low Vision, Stimulus Encoding And Information Processing: A Characterization Of Performance Of Partially Sighted Users On Computer-Based Tasks, Max A. Dixon

FIU Electronic Theses and Dissertations

This study focuses on the characterization of partially sighted users' performance within a graphical user interface environment. Participants, ranging in visual abilities from fully sighted (FSU) with no visual impairments to partially sighted (PSU) with limited visual abilities, participated in computer-based search and select tasks. It is shown that visual search strategies employed by both PSU and FSU within a graphical user interface can be described by Steinberg's (1969) Additive Factor Model. In addition, selection strategies, measured by mouse movement times, are linearly related and highly correlated to the Index of Difficulty as explained by Fitts' Law. This is the …

Relationship Between Technical Knowledge And Price-Perceived Quality In An Industrial Setting, Jeannie Helen Caicedo

FIU Electronic Theses and Dissertations

As proven by many studies, non-industrial consumers perceive price as a strong quality indicator. However, the applicability of this behavior to an industrial setting has been long questioned. It is hypothesized in this research that the levels of price-perceived quality will decrease in an industrial setting as the technical knowledge of the buyer increases. Judgement Sampling method was used to select the most appropriate sample for this study. Since engineers are particularly important influencers in the purchase decision process in organization, engineering students and professors were chosen as the study population. A survey was administered to a sample population that …