Operational Research Commons^™

Locating Emergency Shelters While Incorporating Spatial Factors, Justin Taylor

Graduate Theses and Dissertations

In the immediate response phase of a natural disaster, local governments and nonprofit agencies often establish shelters for affected populations. Decisions regarding at which locations to open shelters are made ad hoc based on available building inventory, and may result in high travel impedance to reach shelters and congestion. This thesis presents a shelter location optimization model based on the two-step floating catchment area (2SFCA) method. The 2SFCA method creates a shelter accessibility score for each areal unit (e.g., census block group) which represents the ability for persons in the unit to access shelter capacity with low travel impedance, relative …

Joint Location And Inventory Models And Algorithms For Deployment Of Hybrid Electric Vehicle Charging Stations., Jie Zhang

Electronic Theses and Dissertations

This thesis describes a study of a novel concept of hybrid electric vehicle charging stations in which two types of services are offered: battery swapping and fast level-3 DC charging. The battery swapping and fast-charging service are modeled by using the M/G/s/s model and the M/G/s/$\infty$ model, respectively. In particular, we focus on the operations of joint battery swapping and fast charging services, develop four joint locations and inventory models: two for the deployment of battery swapping service, two for the deployment of hybrid electric vehicle charging service. The first model for each deployment system considers a service-level constraint for …

Optimization And Simulation Models To Improve Access To Organ Transplantation In The United States., Fatemeh Karami

Electronic Theses and Dissertations

Organ allocation in the U.S. is administrated by the United Network of Organ Sharing (UNOS). UNOS’s mission is to ensure fair and equitable allocation of organs as stated in the Code of Federal Regulations, which reads "neither place of residence nor place of listing shall be a major determinant of access to transplant". Despite the regulations, there has been endless controversy surrounding the disparity in access to organ transplants. In this context, the primary research goal in this dissertation was to reduce geographic disparity in access to transplants in the U.S., with a focus on heart and kidney transplants. To …

Cardiovascular Surgery Practice Remodel: Increasing Job Satisfaction And Reducing Turnover Rates Of Advanced Practice Providers, Christian Brooks

Doctor of Nursing Practice Scholarly Project

Cardiovascular Surgery Practice Remodel: Increasing Job Satisfaction and Reducing Turnover Rates of Advanced Practice Providers

Background: The CVS practice in a Midwestern state had a shift in morale and job satisfaction in their advanced practice providers (APPs). This shift lead to the high turnover rate of 35% in 2018. In an effort to bring a halt to the high turnover rate, and to continue the excellent patient care for which the hospital is known, hospital administration became involved and set up a committee to guide the development of a new CVS APP practice model. The goal was to develop …

Engineering Management Competencies: A Framework For Present And Future Engineering Environments, Christopher Vaughn Barrett

Engineering Management & Systems Engineering Theses & Dissertations

Managing and directing engineering requires engineering management competencies. Although perspectives may differ concerning competencies for engineering management, identifying competencies can direct and improve management. The purpose of this research is to develop a framework of competencies for engineering managers using an inductive research design. Development of this engineering management competency framework involves an exploration of three primary research questions. The first question is ‘What are the current competencies for engineering managers?’ The response to this question provides a basis for the current state of competencies for engineering managers. The second research question, ‘What are future engineering management competencies based on …

Validation Risk Across Hierarchical Models, John B. Young

Computational Modeling & Simulation Engineering Theses & Dissertations

Modeling and simulation are applied in a great many methods across a variety of topics. Model developers and users alike have a professional duty to understand the complexities of the tools and methods they are used. Oftentimes, models that have been independently constructed and executed are used to inform one another for an analytic purpose and the compatibility of the models is not always addressed. In the literature, great attention has been paid to model validation. When using models constructively with one another, analysts must understand the bounds of model validity and ensure that the combination of models does not …

Game Theory Approaches For Transportation Problems, Mahdi Takalloo

USF Tampa Graduate Theses and Dissertations

This dissertation considers three separate game theory problems in transportation. In the first problem, a combinatorial auction market has been proposed for fractional ownership of autonomous vehicles. The proposed combinatorial auction has two unique features. First, the items are continuous time slots defined by bidders and second, the spatial information of bidders has been incorporated so that sharing becomes a viable plan. A conflict-based formulation of the winner determination problem has been proposed, for which an effective solution approach based on a heuristic and a maximal-clique based relaxation has been presented. The second part of the dissertation examines a pessimistic …

A Metamodel Recommendation System Using Meta-Learning, Megan K. Woods

Theses and Dissertations

The importance and value of statistical predictions increase as data grows in availability and quantity. Metamodels, or surrogate models, provide the ability to rapidly approximate and predict information. However, selection of the appropriate metamodel for a given dataset is often arduous, and the choice of the wrong metamodel could lead to considerably inaccurate results. This research proposes and tests the framework for a metamodel recommendation system. The implementation allows for virtually any dataset and preprocesses data, calculates meta-features, evaluates the performance of various metamodels, and learns how the data behaves via meta-learning, thus preparing and bettering itself for future recommendations. …

Database Analysis To Improve U.S. Transportation Command Forecasting Processes, Maxwell C. Thompson

Theses and Dissertations

The United States Transportation Command (USTRANSCOM) facilitates air, land, and sea transportation for the DOD. On a periodic basis, a myriad of different agencies within USTRANSCOM project future workload to facilitate resource planning, budgeting, and reimbursable rate identification. Within USTRANSCOM, there are a variety of databases and metrics utilized for workload forecasts; neither a standard nor a preferred technique is prescribed. Currently, USTRANSCOM faces challenges in producing accurate workload forecasts [1]. These challenges can lead to unreliable budget requests and, ultimately, hinder the effectiveness and efficiency of USTRANSCOM [1]. For the purpose of routine aircraft movements of cargo and personnel, …

Change Management Processes In Model-Based Systems Engineering, Isabeta Rountree, Victor Lopez

Research Horizons Day Posters

No abstract provided.

Explaining Weapon System Sustainment's Impact To Aircraft Availability, Michael D. Ingram

Theses and Dissertations

This research focused on understanding the phenomena behind the cost growth of Weapon System Sustainment (WSS) and the simultaneous degradation in USAF aircraft system availability. The primary modelling technique used was Ordinary Least Squares (OLS) while incorporating temporal effect. Other studies have looked at cost factors related to the Flying Hour Program, flying conditions and age. This study found empirical relationships between each of the four WSS business processes and the lead time in months it takes to realize improvements in system aircraft availability.

Predicting Upper Atmospheric Weather Conditions Utilizing Long-Short Term Memory Neural Networks For Aircraft Fuel Efficiency, Garrett A. Alarcon

Theses and Dissertations

Aviation fuel is a major component of the Air Force (AF) budget, and vital for the core mission of the AF. This study investigated the viability of LSTMs to increase the accuracy of deterministic NWP models, while also investigating the ability to reduce model generation time. Increased forecast accuracy for wind speeds could be implemented into existing flight path models to further increase fuel efficiency, while reduced modeling times would allow flight planners to generate a flight plan in rapid response situations. The most viable model consisted of an ensemble of six LSTMs trained o six coordinates. The model's error …

Heuristic Approaches For Near-Optimal Placement Of Gps-Based Multi-Static Radar Receivers In American Coastal Waters, Brandon J. Hufstetler

Theses and Dissertations

Narcotics smuggling across the Caribbean Sea is a growing concern for the United States Coast Guard. One vector for this illicit trafficking is via small aircraft. This thesis proposes a multi-static radar architecture using the Global Positioning System (GPS) constellation as a transmission source to detect these aircraft as they transit a detection fence. The system developed in this thesis relies on the forward-scatter phenomenon in which a radar shadow is cast by a target as it crosses in front of a transmitter, creating a measurable difference in the signal amplitude at the receiver. This thesis first develops a mathematical …

Analysis With Dynamic Bayesian Networks Compared To Simulation, Aaron J. Salazar

Theses and Dissertations

This research compares simulations to Dynamic Bayesian Networks in analyzing situations. The research applies models that have known output mean and variance. Queueing systems have theoretical values of the steady-state mean and variance for the number of entities in the system. Monte Carlo simulation development is broken down into two separate approaches: discrete-event simulation and time-oriented simulation. The discrete-event simulation uses pseudo-random numbers to schedule and trigger future events (i.e. customer arrivals and services) and is based on the generated objects.The time-oriented simulation utilizes fixed-width time intervals and updates the system state according to a stochastic process for the set …

Analysis And Forecasting Of The 360th Air Force Recruiting Group Goal Distribution, Tyler Spangler

Theses and Dissertations

This research utilizes monthly data from 2012-2017 to determine economic or demographic factors that significantly contribute to increased goaling and production potential in areas of the 360th Recruiting Groups. Using regression analysis, a model of recruiting goals and production is built to identify squadrons within the 360 RCGs zone that are capable of producing more or fewer recruits and the factors that contribute to this increased or decreased capability. This research identifies that a zones high school graduation rate, the number of recruiters, and the number of JROTC detachments in a zone are positively correlated with recruiting goals and that …

Dual-Axis Solar Tracker, Bryan Kennedy

All Undergraduate Projects

Renewable energies, and fuels that are not fossil fuel-based, are one of the prolific topics of debate in modern society. With climate change now becoming a primary focus for scientists and innovators of today, one of the areas for the largest amount of potential and growth is that of the capturing and utilization of Solar Energy. This method involves using a mechanical system to track the progression of the sun as it traverses the sky throughout the day. A dual-axis solar tracker such as the one designed and built for this project, can follow the sun both azimuthally and in …

Short-Term Truckload Spot Rates' Prediction In Consideration Of Temporal And Between-Route Correlations, Wei Xiao, Chuan Xu, Hongling Liu, Hong Yang, Xiaobo Liu

Computational Modeling & Simulation Engineering Faculty Publications

Truckload spot rate (TSR), defined as a price offered on the spot to transport a certain cargo by using an entire truck on a target transportation line, usually price per kilometer-ton, is a key factor in shaping the freight market. In particular, the prediction of short-term TSR is of great importance to the daily operations of the trucking industry. However, existing predictive practices have been limited largely by the availability of multilateral information, such as detailed intraday TSR information. Fortunately, the emerging online freight exchange (OFEX) platforms provide unique opportunities to access and fuse more data for probing the trucking …

Research On Integration And Optimization Of Cosco Industrial Chain, Xiang Yan

International Transport and Logistics

No abstract provided.

Dynamic Resource Allocation For Coordination Of Inpatient Operations In Hospitals, Najibesadat Sadatijafarkalaei

Wayne State University Dissertations

Healthcare systems face difficult challenges such as increasing complexity of processes, inefficient utilization of resources, high pressure to enhance the quality of care and services, and the need to balance and coordinate the staff workload. Therefore, the need for effective and efficient processes of delivering healthcare services increases. Data-driven approaches, including operations research and predictive modeling, can help overcome these challenges and improve the performance of health systems in terms of quality, cost, patient health outcomes and satisfaction.

Hospitals are a key component of healthcare systems with many scarce resources such as caregivers (nurses, physicians) and expensive facilities/equipment. Most hospital …

แบบจำลองสถานการณ์ของเหตุการณ์ที่ไม่ต่อเนื่องเพื่อประเมินประสิทธิภาพของท่าเรือบก กรณีศึกษาท่าเรือบกลาดกระบัง, พิพัฒน์ พิมพะนิตย์

Chulalongkorn University Theses and Dissertations (Chula ETD)

ท่าเรือบกเป็นหนึ่งในสิ่งอำนวยความสะดวกหลักในเครือข่ายการขนส่งทางทะเล ที่ช่วยให้ผู้ขนส่งสามารถเข้าถึงภูมิภาคต่าง ๆ ของโลกได้ ผ่านการเชื่อมต่อกับท่าเรือ ในขณะที่ผลกระทบของท่าเรือบกต่อประสิทธิภาพของการขนส่งแบบหลายรูปแบบนั้นค่อนข้างมีความชัดเจนในช่วงเวลาที่ผ่านมา การประเมินประสิทธิภาพของท่าเรือบกเองกลับมีความซับซ้อน เนื่องจากมีความเกี่ยวพันกับผู้ให้บริการที่หลากหลาย ซี่งแต่ละผู้ให้บริการต่างก็บริหารจัดการทรัพยากรภายใน หรือ CHE ที่มีจำนวนแตกต่างกันออกไป ด้วยเหตุดังกล่าว ผู้วิจัยจึงได้นำเสนอแบบจำลองสถานการณ์ของเหตุการณ์ที่ไม่ต่อเนื่อง เพื่อใช้ในการประเมินประสิทธิภาพของท่าเรือบกลาดกระบัง (LICD) ในปัจจุบัน และในอนาคต ผ่านโปรเเกรม SIMIO โดยอ้างอิงจากข้อมูลของ LICD ในปัจจุบัน และแผนการปรับปรุง LICD ใหม่ จากการศึกษา ผู้วิจัยพบว่า เมื่อพิจารณาจากประสิทธิภาพการใช้งานของทรัพยากรภายใน LICD ประสิทธิภาพโดยรวมของ LICD ในปัจจุบันมีค่าค่อนข้างต่ำ โดยเฉพาะอย่างยิ่งสำหรับรถบรรทุกหัวลากภายใน นอกจากนี้ผู้วิจัยยังพบว่า ประสิทธิภาพของการใช้งานทรัพยากรภายในมีแนวโน้มที่เปลี่ยนแปลงไปอย่างเห็นได้ชัด เมื่อมีการเปลี่ยนสัดส่วนการขนส่งตามนโยบายการขนส่งใหม่ ในทำนองเดียวกัน ประสิทธิภาพโดยรวมของ LICD ในอนาคตนั้น ส่วนใหญ่ขึ้นอยู่กับจำนวนของทรัพยากรภายในแต่ละประเภทที่ถูกสรรหามาในแต่ละรอบการสรรหา โดยรถเครนขนถ่ายตู้คอนเทนเนอร์ปกติ หรือ FCL Crane จัดเป็นทรัพยากรภายในหลักที่มีแนวโน้มการใช้งานมากสูงสุด ด้วยเหตุดังกล่าว ผู้วางแผนจึงควรจัดหา FCL Crane ในแต่ละรอบการสรรหาให้เหมาะสมกับจำนวนตู้คอนเทนเนอร์ที่มีการขนถ่ายผ่าน LICD เพื่อให้ LICD สามารถดำเนินการได้อย่างมีประสิทธิภาพสูงสุด