Engineering Commons^™

Improving Non-Linear Approaches To Anomaly Detection, Class Separation, And Visualization, Todd J. Paciencia

Theses and Dissertations

Linear approaches for multivariate data analysis are popular due to their lower complexity, reduced computational time, and easier interpretation. In many cases, linear approaches produce adequate results; however, non-linear methods may generate more robust transformations, features, and decision boundaries. Of course, these nonlinear methods present their own unique challenges that often inhibit their use. In this research, improvements to existing non-linear techniques are investigated for the purposes of providing better, timely class separation and improved anomaly detection on various multivariate datasets, culminating in application to anomaly detection in hyperspectral imagery. Primarily, kernel-based methods are investigated, with some consideration towards other …

Effective Multi-Echelon Inventory Systems For Supplier Selection And Order Allocation, Cong Guo

Doctoral Dissertations

Successful supply chain management requires an effective sourcing strategy to counteract uncertainties in both the suppliers and demands. Therefore, determining a better sourcing policy is critical in most of industries. Supplier selection is an essential task within the sourcing strategy. A well-selected set of suppliers makes a strategic difference to an organization's ability to reduce costs and improve the quality of its end products. To discover the cost structure of selecting a supplier, it is more interesting to further determine appropriate levels of inventory in each echelon for different suppliers. This dissertation focuses on the study of the integrated supplier …

Truckload Shipment Planning And Procurement, Neo Nguyen

Graduate Theses and Dissertations

This dissertation presents three issues encountered by a shipper in the context of truckload transportation. In all of the studies, we utilize optimization techniques to model and solve the problems. Each study is inspired from the real world and much of the data used in the experiments is real data or representative of real data.

The first topic is about the freight consolidation in truckload transportation. We integrate it with a purchase incentive program to increase truckload utilization and maximize profit. The second topic is about supporting decision making collaboration among departments of a manufacturer. It is a bi-objective optimization …

Strategic Planning Tool Development Using Portfolio Decision Analysis, Luis B. Vargas Rojas

Graduate Theses and Dissertations

A portfolio decision analysis strategic planning tool was developed for the Facilities Management Office at the University of Arkansas. The tool provides information to support budget allocation decisions based on their Strategic Planning Project List, project attributes (e.g, seat utilization, scheduling preferences, and sustainability rank), and budget constraints. The projects are evaluated using multiobjective decision analysis. We introduce dynamic value functions, which vary the range of the value measures based on the planning horizon, to evaluate the projects). We determine facilities portfolios based on the project values and constraints using Linear Programming. In addition, insightful reports are generated, which provide …

Optimizing Consumer-Centric Assortment Planning Under Cross-Selling Effects, Ameera Ibrahim

Doctoral Dissertations

Central to modern-time, consumer-focused retailing is the ability to provide attractive and reasonably-priced product assortments for different customer profiles. To this end, retailers can benefit from the use of data analytics in order to identify distinct customer segments, each characterized by their buying power, shopping behavior, and preferences. Further, retailers can also benefit from a careful examination of alternative procurement options and cost levers associated with products that are considered for inclusion in the assortment. Issues of assortment planning lie at the interface of operations and marketing. Profitable planning trade-offs can be identified using an optimization methodology and are simultaneously …

Operational Planning In Combined Heat And Power Systems, Hariharan Gopalakrishnan

Doctoral Dissertations

This dissertation presents methodologies for operational planning in Combined Heat and Power (CHP) systems. The subject of experimentation is the University of Massachusetts CHP system, which is a 22 MWe/640 MBh system for a district energy application. Systems like this have complex energy flow networks due to multiple interconnected thermodynamic components like gas and steam turbines, boilers and heat recovery steam generators and also interconnection with centralized electric grids. In district energy applications, heat and power requirements vary over 24 hour periods (planning horizon) due to changing weather conditions, time-of-day factors and consumer requirements. System thermal performance is highly dependent …

Application Of Bayesian Networks In Consumer Service Industry, Yuan Gao

Open Access Theses

Gao, Yuan. M.S.I.E., Purdue University. December 2014. Application of Bayesian Networks in Consumer Service Industry. Major professor: Vincent G. Duffy The purpose of the present study is to explore the application of Bayesian networks in the consumer service industry to model causal relationships within complex risk factor structures using aggregate data. An analysis of the Hawaii tourism market was conducted to find out how visitor characteristics affect their behavior and experience as consumers during the trips, and influence the tourism market outcomes represented by measurable factors. Two hypotheses were proposed regarding the use of aggregate data and the influence of …

Stochastic Models For Capacity Planning In Healthcare Delivery: Case Studies In An Outpatient, Inpatient And Surgical Setting, Asli Ozen

Doctoral Dissertations

U.S. healthcare system has become far too complex and costly to sustain and operations research has much to contribute in improving health systems by addressing a large spectrum of problems. We study capacity planning in healthcare while considering the case-mix of patients, using stochastic modeling in different application areas: primary care, inpatient bed allocation and (spine) surgery scheduling. This body of work was developed over four years of collaborative research with hospitals and healthcare providers. The main objective of our research in primary care is to optimize the patient mix of primary care physicians in a group practice to maximize …

Interpreting, Stephanie Jo Kent

Doctoral Dissertations

What do community interpreting for the Deaf in western societies, conference interpreting for the European Parliament, and language brokering in international management have in common? Academic research and professional training have historically emphasized the linguistic and cognitive challenges of interpreting, neglecting or ignoring the social aspects that structure communication. All forms of interpreting are inherently social; they involve relationships among at least three people and two languages. The contexts explored here, American Sign Language/English interpreting and spoken language interpreting within the European Parliament, show that simultaneous interpreting involves attitudes, norms and values about intercultural communication that overemphasize information and discount …

Runway Operations Management: Models, Enhancements, And Decomposition Techniques, Farbod Farhadi

Doctoral Dissertations

Air traffic loads have been on the rise over the last several decades and are expected to double, and possibly triple in some regions, over the coming decade. With the advent of larger aircraft and ever-increasing air traffic loads, aviation authorities are continually pressured to examine capacity expansions and to adopt better strategies for capacity utilization. However, this growth in air traffic volumes has not been accompanied by adequate capacity expansions in the air transport infrastructure. It is, therefore, predicted that flight delays costing multi-billion dollars will continue to negatively impact airline companies and consumers. In airport operations management, runways …

Xiamen Port Bulk Cargo Collection And Distribution Systems Optimization, Juntao Cai

World Maritime University Dissertations

No abstract provided.

Optimization Waiting Time At Container Terminal In Port Of Tanjung Perak Indonesia, Andry Hernawan Prihananto

World Maritime University Dissertations

No abstract provided.

Storage Space Allocation In Container Terminals With Mixed Storage Mode Under Uncertain Conditions, Jia Hu

World Maritime University Dissertations

No abstract provided.

The Evaluation Of Iron Ore Logistics Efficiency Of The Port Based On The Dea Model, Jiong Yan

World Maritime University Dissertations

No abstract provided.

Research On Optimizing Liner Routing Schedule Of Zhonggu Shipping Company, Jiajun Chen

World Maritime University Dissertations

No abstract provided.

Operating System Optimization In Multipurpose Terminal Of Palembang Port, Dewa Cipta Hadi

World Maritime University Dissertations

No abstract provided.

Function And Design Of Simulation System For The Workload Distribution Among Storage Blocks In A Container Terminal Yard, Dongyuan Ren

World Maritime University Dissertations

No abstract provided.

Automated Image Interpretation For Science Autonomy In Robotic Planetary Exploration, Raymond Francis

Electronic Thesis and Dissertation Repository

Advances in the capabilities of robotic planetary exploration missions have increased the wealth of scientific data they produce, presenting challenges for mission science and operations imposed by the limits of interplanetary radio communications. These data budget pressures can be relieved by increased robotic autonomy, both for onboard operations tasks and for decision- making in response to science data.

This thesis presents new techniques in automated image interpretation for natural scenes of relevance to planetary science and exploration, and elaborates autonomy scenarios under which they could be used to extend the reach and performance of exploration missions on planetary surfaces.

Two …

Optimization Of Healthcare Delivery System Under Uncertainty: Schedule Elective Surgery In An Ambulatory Surgical Center And Schedule Appointment In An Outpatient Clinic, Zhaoxia Zhao

Doctoral Dissertations

This work investigates two types of scheduling problems in the healthcare industry. One is the elective surgery scheduling problem in an ambulatory center, and the other is the appointment scheduling problem in an outpatient clinic.

The ambulatory surgical center is usually equipped with an intake area, several operating rooms (ORs), and a recovery area. The set of surgeries to be scheduled are known in advance. Besides the surgery itself, the sequence-dependent setup time and the surgery recovery are also considered when making the scheduling decision. The scheduling decisions depend on the availability of the ORs, surgeons, and the recovery beds. …

Large-Scale Solution Approaches For Healthcare And Supply Chain Scheduling, Ridvan Gedik

Graduate Theses and Dissertations

This research proposes novel solution techniques for two real world problems. We first consider a patient scheduling problem in a proton therapy facility with deterministic patient arrivals. In order to assess the impacts of several operational constraints, we propose single and multi-criteria linear programming models. In addition, we ensure that the strategic patient mix restrictions predetermined by the decision makers are also enforced within the planning horizon. We study the mathematical structures of the single criteria model with strict patient mix restrictions and derive analytical equations for the optimal solutions under several operational restrictions. These efforts lead to a set …

Production Scheduling In Integrated Steel Manufacturing, Wanxi Li

Theses and Dissertations

Steel manufacturing is both energy and capital intensive, and it includes multiple production stages, such as iron-making, steelmaking, and rolling. This dissertation investigates the order schedule coordination problem in a multi-stage manufacturing context. A mixed-integer linear programming model is proposed to generate operational (up to the minute) schedules for the steelmaking and rolling stages simultaneously. The proposed multi-stage scheduling model in integrated steel manufacturing can provide a broader view of the cost impact on the individual stages. It also extends the current order scheduling literature in steel manufacturing from a single-stage focus to the coordinated multi-stage focus. Experiments are introduced …

Time-Based Collision Risk Modeling For Air Traffic Management, Alan E. Bell

Engineering Management & Systems Engineering Theses & Dissertations

Since the emergence of commercial aviation in the early part of last century, economic forces have driven a steadily increasing demand for air transportation. Increasing density of aircraft operating in a finite volume of airspace is accompanied by a corresponding increase in the risk of collision, and in response to a growing number of incidents and accidents involving collisions between aircraft, governments worldwide have developed air traffic control systems and procedures to mitigate this risk. The objective of any collision risk management system is to project conflicts and provide operators with sufficient opportunity to recognize potential collisions and take necessary …

Multi-Criteria Decision Modeling For Best Value Selections In Target Value Design Integrated Project Delivery, Brent Patrick Griffis

Master's Theses

Integrated Project Delivery (IPD) combined with Target Value Design (TVD) is a better way to deliver value for the client than traditional guaranteed maximum price (GMP) methods. With traditional GMP delivery methods, the interests of the parties are often at odds. The goal of IPD is to align all party interests in order to achieve a win-win scenario. Due to the aligning nature of IPD and the fact that each party’s success is dependent on achieving the project objectives as a whole; a non-biased, transparent, decision-making process is necessary in order to deliver the project objectives within the constraints of …

A Set Union Based Formulation For Course Scheduling And Timetabling, Jesse Paul Bukenberger

Master's Theses

The Course Timetabling Problem is a widely studied optimization problem where a number of sections are scheduled in concert with the assignment of students to sections in order to maximize the desirability of the resulting schedule for all stakeholders. This problem is commonly solved as a linear program with variables for each student or group of students with identical schedules. In this paper we explore an alternative formulation that aggregates binary student variables into integer variables denoting the number of students enrolled in a course. Our solution method assumes decomposition of the general schedule into time blocks, and applies a …

The Feasibility Of Citywide Public Drt: Door-To-Door Bus Service In Tacoma, Nathan Pastor

Honors Program Theses

This paper examines the feasibility of operating Demand Responsive Transit (DRT) as the primary mode of mass transit in Tacoma, WA. With the promise of door-to-door service anywhere within a region, DRT has the potential to attract new discretionary mass transit riders while serving demand more efficiently than fixed-route systems. We present an algorithm for generating realistic datasets of riders based on employment and demographic data at the census tract level, which are fed through a simulated dynamic DRT system in Tacoma (TacDRT). The TacDRT service is considered feasible if it can serve the same volume of demand that the …

Strategic Technology Maturation And Insertion (Stmi): A Requirements Guided, Technology Development Optimization Process, James Brill Clegern

Doctoral Dissertations

This research presents a Decision Support System (DSS) process solution to a problem faced by Program Managers (PMs) early in a system lifecycle, when potential technologies are evaluated for placement within a system design. The proposed process for evaluation and selection of technologies incorporates computer based Operational Research techniques which automate and optimize key portions of the decision process. This computerized process allows the PM to rapidly form the basis of a Strategic Technology Plan (STP) designed to manage, mature and insert the technologies into the system design baseline and identify potential follow-on incremental system improvements. This process is designated …

Detailed Inventory Record Inaccuracy Analysis, Hayrettin Kaan Okyay

Graduate Theses and Dissertations

This dissertation performs a methodical analysis to understand the behavior of inventory record inaccuracy (IRI) when it is influenced by demand, supply and lead time uncertainty in both online and offline retail environment separately. Additionally, this study identifies the susceptibility of the inventory systems towards IRI due to conventional perfect data visibility assumptions. Two different alternatives for such methods are presented and analyzed; the IRI resistance and the error control methods. The discussed methods effectively countered various aspects of IRI; the IRI resistance method performs better on stock-out and lost sales, whereas error control method keeps lower inventory. Furthermore, this …

Operations Research Modeling Of Cyclic Train Timetabling, Cyclic Train Platforming, And Bus Routing Problems, Mojtaba Heydar

Theses and Dissertations

Public transportation or mass transit involves the movement of large numbers of people between a given numbers of locations. The services provided by this system can be classified into three groups: (i) short haul: a low-speed service within small areas with high population; (ii) city transit: transporting people within a city; and (iii) long haul: a service with long trips, few stops, and high speed (Khisty and Lall, 2003). It can be also classified based on local and express services. The public transportation planning includes five consecutive steps: (i) the network design and route design; (ii) the setting frequencies or …

Understanding The Electricity-Water-Climate Change Nexus Using A Stochastic Optimization Approach, Ivan Saavedra Antolinez

Theses and Dissertations

Climate change has been shown to cause droughts (among other

catastrophic weather events) and it is shown to be exacerbated by the

increasing levels of greenhouse gas emissions on our planet. In May 2013, CO₂ daily average concentration over the Pacific Ocean at Mauna Loa Observatory reached a dangerous milestone of 400 ppm, which has not been experienced in thousands of years in the earth's climate. These levels were attributed to the ever-increasing human activity over the last 5-6 decades. Electric power generators are documented by the U.S. Department of Energy to be the largest users of ground and …

Robust Network Interdiction With Invisible Interdiction Assets, Nail Orkun Baycik

Graduate Theses and Dissertations

We study a version of the shortest path network interdiction problem in which the follower seeks to find the shortest path on a given network and the leader seeks to maximize the follower's shortest path length by interdicting arcs. We consider placement of interdictions that are not visible to the follower; however, we seek to locate interdictions in a manner that is robust against the possibility that some interdiction locations become known to the follower. We formulate the problem as a bi-level program, and use the simulated annealing heuristic to identify high quality solutions. We apply our approach to investigate …