Operational Research Commons^™

Location And Capacity Modeling Of Network Interchanges, Aldo D. Fabregas

USF Tampa Graduate Theses and Dissertations

Network design decisions, especially those pertaining to urban infrastructure, are made by a central authority or network leader, and taking into consideration the network users or followers. These network decision problems are formulated as non-linear bi-level programming problems. In this work, a continuous network design problem (CNDP) and discrete network design problem (DNDP) bi-level optimization programs are proposed and solved in the context of transportation planning. The solution strategy involved reformulation and linearization as a single-level program by introducing the optimality conditions of the lower level problem into the upper level problem. For the CNDP, an alternative linearization algorithm (modified …

Exact And Representative Algorithms For Multi Objective Optimization, Ozgu Turgut

Wayne State University Dissertations

In most real-life problems, the decision alternatives are evaluated with multiple conflicting criteria. The entire set of non-dominated solutions for practical problems is impossible to obtain with reasonable computational effort. Decision maker generally needs only a representative set of solutions from the actual Pareto front. First algorithm we present is for efficiently generating a well dispersed non-dominated solution set representative of the Pareto front which can be used for general multi objective optimization problem. The algorithm first partitions the criteria space into grids to generate reference points and then searches for non-dominated solutions in each grid. This grid-based search utilizes …

Engineering Problem Solving And Sustained Learning: A Mixed Methods Study To Explore The Dynamics Of Engineering Knowledge Creation, Rachel Itabashi-Campbell

Wayne State University Dissertations

This dissertation research explores processes by which engineering problem solving (EPS) results in sustained organizational learning. Approaching from a constructionist perspective, the study empirically examines the knowledge creation dynamics instigated by product-related problems using a mixed methods research approach. The research has identified the Japanese concept of ba, defined in this study as "shared experiential space," as a key construct that explains the phenomena of interest. A new framework that the study has developed, which interprets EPS as an epistemic journey to attain system-wide improvements, is highly complementary to the traditional structured routine based approaches to engineering operations and …

Demand Modeling And Capacity Planning For Innovative Short Life-Cycle Products, Saman Alaniazar

Wayne State University Dissertations

This dissertation focuses on demand modeling and capacity planning for innovative short life-cycle products. We first developed a new model in the class of stochastic Bass formulations that addresses the shortcomings of models from the extant literature. The proposed model considers the common fact that the market potential of a product is not fixed and might change during a life-cycle due to exogenous (e.g., economic- or competitors-related) or endogenous (e.g., quality-related) factors. Allowing this parameter (market potential in the Bass model) to follow a geometric random walk, we have showed that the future demand of a product in each period …

Investigation Into The Measure, Correlate And Predict Methodologies Used In Wind Farm Design Software, Brendan O'Sullivan

Theses

This paper is focused on the Measure Correlate and Predict (MCP) methodologies used to estimate long term wind resource at a prospective site. The first common step in all MCP methodologies is a successful wind measurement campaign at the prospective site. This campaign involves the erection of a wind measurement mast (ideally to the hub height of the proposed turbine) and careful selection of booms, mountings and anemometers. The wind measurement campaign is a vital part of the process as the correlation and prediction analysis is only as accurate as the measured wind data. Correlation is a measure of the …

Evaluating Food Safety Systems Development And Implementation By Quantifying Haccp Training Durability, Marienne A. Anandappa

Theses and Dissertations--Animal and Food Sciences

HACCP-based food safety programs have been widely acclaimed, accepted and implemented as an effective means of managing food safety risks. While HACCP training is a cornerstone of managing HACCP programs, there is little information about the effectiveness of HACCP training and the durability of HACCP knowledge. Findings reveal a link between involvement level in HACCP activities and the accuracy of HACCP knowledge over time. Opportunities for peer training in HACCP, irrespective of overall experience in the food industry provide favorable circumstances for maintaining accuracy of HACCP knowledge. The optimal window for engaging employees in HACCP is directly following the completion …

Novel Models And Algorithms For Uncertainty Management In Power Systems, Long Zhao

USF Tampa Graduate Theses and Dissertations

This dissertation is a collection of previously-published manuscript and conference papers. In this dissertation, we will deal with a stochastic unit commitment problem with cooling systems for gas generators, a robust unit commitment problem with demand response and uncertain wind generation, and a power grid vulnerability analysis with transmission line switching. The latter two problems correspond to our theoretical contributions in two-stage robust optimization, i.e., how to efficiently solve a two-stage robust optimization, and how to deal with mixed-integer recourse in robust optimization. Due to copyright issue, this dissertation does not include any methodology papers written by the author during …

A Methodology For Scheduling Operating Rooms Under Uncertainty, Marbelly Paola Davila

USF Tampa Graduate Theses and Dissertations

An operating room (OR) is considered to be one of the most costly functional areas within hospitals as well as its major profit center. It is known that managing an OR department is a challenging task, which requires the integration of many actors (e.g., patients, surgeons, nurses, technicians) who may have conflicting interests and priorities.

Considering these aspects, this dissertation focuses on developing a simulation based methodology for scheduling operating rooms under uncertainty, which reflects the complexity, uncertainty and variability associated with surgery.

We split the process of scheduling ORs under uncertainty into two main components. First, we designed a …

Experiments To Measure The Effects Of Timber Harvesting Equipment On Surface Lithic Scatters, Douglas J. Baughman

All Master's Theses

The importance of cultural resource preservation cannot be overstated; however local economies are at least as important. Due to conservative archaeological site protection practices in Region 5 of the United States Forest Service, the economy of Northeastern California is being adversely affected. In an attempt to help the Forest Service make more informed management decisions and improve the Northeastern California economy, I undertook experiments on the effects of timber harvesting on lithic scatters on Modoc National Forest. The experiments involved placement of 225 glass tiles (proxy lithics) in each of three plots subject to vehicle traffic and log dragging by …

Nylon Tension Pid Control During Raw Tire Assembly, Yuan-Yu Luo

College of Graduate Studies: Theses & Dissertations

The purpose of this study is to evaluate several control methods to see which one has the best control of nylon tension during raw tire assembly. After nylon application step of the tire building process, the shape of the tire will undergo inflation that causes the nylon layers to expand and produces tension gradient. To overcome such a problem, the process needs to preapply a nylon trip with a gradient of tension so the tension can be balanced after the inflation step. The study evaluated several PID controllers and gathered data to see which controller results in the best nylon …

Optimization Of Biomass Logistics System Using Genetic Algorithm And Particle Swarm Optimization For Biofuel Production, Ethel Regina Martinez-Schabez

Open Access Theses & Dissertations

As time goes by, Renewable Energy keeps proving to be an important and potential replacement for fossil fuels. All the different types of Renewable Energy offer a relief to the environmental aftermaths of the prolonged reliance on fossil fuel energy. Bioenergy is one of the types of Renewable Energy that can help by minimizing the emissions of fossil fuels. The Energy Independence and Security Act mandates the use of 21 billion gallons of advanced biofuels including 16 billion gallons of cellulosic biofuels by the year 2022. Biomass and Biofuels can clearly become a significant aid to sustainably supply energy in …

Supply Chain Optimization Of Blood Products, Serkan Gunpinar

USF Tampa Graduate Theses and Dissertations

Major challenges in the management of blood supply chain are related to the shortage and wastage of the blood products. Given the perishability characteristics of blood which can be stored up to a limited number of days, if hospitals and blood centers keep an excessive number of blood units on inventory, wastages may occur. On the other hand, if sufficient number of blood units are not stored on inventory, shortages of this resource may cause the cancellations of important activities and increase the fatality rates at hospitals. Three mathematical models have been developed with the goal to improve the efficiency …

The Enterprise Aid Methodology: Concepts, Thomas J. Meyers, Patrick T. Hester

Engineering Management & Systems Engineering Faculty Publications

The Enterprise AID − for assessment, improvement, and design − methodology is a systems science-, operational test and evaluation-, and multicriteria decision analysis-based approach to design and deployment of performance measurement systems (PMSs) tailored to specific enterprises pursuing any or all of enterprise assessment, improvement, or design. Its two phases of design and deployment sprang from designers’ inductively generated and now prototyped response to a gap they recognized between performance measurement capabilities required by contemporary enterprises and those offered by contemporary PMSs. This paper illustrates key concepts underlying AID, while a companion document, The Enterprise AID methodology: Application, draws from …

Simulation Modeling And Analysis Of Complex Port Operations With Multimodal Transportation, Mariam Kotachi, Ghaith Rabadi, Mohammad F. Obeid

Engineering Management & Systems Engineering Faculty Publications

World trade has been increasing dramatically in the past two decades, and as a result containers exchange has grown significantly. Accordingly, container terminals are expanding to meet this increase and new container ports have opened. Ports with one or more container terminals are considered complex systems in which many resources, entities and transporters interact to achieve the objective of safely moving containers delivered by ships inland as well as loading containers delivered by trucks and rail onto ships. Ports with multimodal transportation systems are in particular complex as they typically operate with ships arriving to one or more terminals, multiple …

A Theory Of Emergence And Entropy In Systems Of Systems, John J. Johnson Iv, Andreas Tolk, Andres Sousa-Poza

Engineering Management & Systems Engineering Faculty Publications

Systems of Systems (SOS) meet vital needs in our society by providing capabilities that are not possible by their discrete components or subsystems. Some SOS are engineered to produce predictable results, yet they can still display emergent behavior. These behaviors are often considered negative because they are not a function of the design. However, emergent behavior can also be serendipitous and produce unexpected positive results. The authors formalize a theory of emergence based on entropy. The theory has explanatory value for emergence as an ontological and phenomenological concept in systems of systems. © 2013 The Authors.

Accounting For Errors When Using Systems Approaches, Kevin Macg. Adams, Peggy Hester

Engineering Management & Systems Engineering Faculty Publications

Complex systems problems require the use of a formal philosophical construct and dictate the use of a rigorous systems approach. A systems approach may utilize one of a variety of proven methods, but in each case it involves the imposition of order that ranges from the philosophical to the procedural. Independent of the construct or rigor used to address the complex systems problem is the opportunity to commit a number of errors as part of a systems approach. This paper will discuss six classifications for problem solving errors that may be experienced during the application of a systems approach as …

Using Modelling And Simulation To Improve Elderly Care In Ireland: A Case Study, Mohamed Ragab, Wael Rashwan, Waleed Abo-Hamad, Amr Arisha

Articles

Health care services both globally and domestically - are encountering critical issues due to the increasing demand for services at the time of economic recession. Hospital performance is subject to many constraints, and planning is made more difficult by the complexity and uncertainty of demand. Population ageing is creating immense pressures on healthcare facilities across the world, leaving them struggling to cope with the growing demand for elderly healthcare services. Current demand-supply gaps result in prolonged waiting times for patients and substantial cost burdens for healthcare systems due to delayed discharges. This paper reports on a project that uses modelling …

On The Maintenance Modeling And Optimization Of Repairable Systems: Two Different Scenarios, Suzan Alaswad

Graduate Theses and Dissertations

The use of mathematical modeling for the purpose of analyzing and optimizing the performance of repairable systems is widely studied in the literature. In this dissertation, we study two different scenarios on the maintenance modeling and optimization of repairable systems. First, we study the long-run availability of a traditional repairable system that is subjected to imperfect corrective maintenance. We use Kijima's second virtual age model to describe the imperfect repair process. Because of the complexity of the underlying probability models, we use simulation modeling to estimate availability performance and meta-modeling to convert the reliability and maintainability parameters of the repairable …

Capacity Planning For Elderly Care In Ireland Using Simulation Modeling, Mohamed Ragab, Waleed Abo Hamad, Amr Arisha

Conference papers

Global population aging is creating an immense pressure on healthcare facilities making them unable to cope with the growing demand for elderly healthcare services. Current demand-supply gaps result in prolonged waiting times for patients and substantial cost burdens for healthcare systems due to delayed discharges. This paper describes a project aimed at presenting modeling and simulation to address elderly care pathways within the Irish healthcare sector. The management of frail patients admitted to acute hospitals and the introduction of the new intermediate care beds are alternative interventions that healthcare executives are interested in simulating to examine their impact on the …

The Factors Behind A Successful Implementation Of Electronic Health Records Systems, Anjee Gorkhali

Engineering Management & Systems Engineering Theses & Dissertations

This research explores the role that budget for Information System (IS) and technical expertise of healthcare service provider staff play on the successful leap from a partial to exhaustive implementation of Electronic Health Records (EHR) Systems. Technical expertise in Information Systems might not be easily measurable directly, but there are a number of indicators that could be used as a proxy, such as: Information System (IS) Department Budget, number of IS staff and the extent of technical trainings provided by the IS department to the clinical staff. This research study hypothesizes that quality technical trainings conducted by an IS department …