Operations Research, Systems Engineering and Industrial Engineering Commons^™

Heuristics For Capacity Allocation And Queue Assignment In Congested Service Systems With Stochastic Customer Demand And Immobile Servers, Adam Colley

Operations Research and Engineering Management Theses and Dissertations

We propose easy-to-implement heuristics for a problem referred to in the literature as the facility location problem with immobile servers, stochastic demand, and congestion, or the service system design problem. The problem is typically posed as one of allocating capacity to a set of M/M/1 queues to which customers with stochastic demand are assigned with the objective of minimizing a cost function composed of a fixed capacity-acquisition cost, a variable customer-assignment cost, and an expected-waiting-time cost. The expected-waiting-time cost results in a non-linear term in the objective function of the standard binary programming formulation of the problem. Thus, the solution …

Exploring The Effects Of Meaningful Tactile Display On Perception And Preference In Automated Vehicles, Kimberly D. Martinez, Gaojian Huang

Mineta Transportation Institute Publications

There is an existing issue in human-machine interaction, such that drivers of semi-autonomous vehicles are still required to take over control of the vehicle during system limitations. A possible solution may lie in tactile displays, which can present status, direction, and position information while avoiding sensory (e.g., visual and auditory) channels overload to reliably help drivers make timely decisions and execute actions to successfully take over. However, limited work has investigated the effects of meaningful tactile signals on takeover performance. This study synthesizes literature investigating the effects of tactile displays on takeover performance in automated vehicles and conducts a human-subject …

Analysis Of A Queueing Model With Map Arrivals And Heterogeneous Phase-Type Group Services, Srinivas R. Chakravarthy

Industrial & Manufacturing Engineering Publications

Queueing models have proven to be very useful in real-life applications to enable the practitioners to optimize the limited resources to conduct their businesses as well as offer services efficiently. In general, we can group such applications into two sectors: manufacturing and service. These two sectors cover everything we deal with on a day-to-day basis. Queues in which the services are offered in blocks (or groups or batches) are well established in the literature and have a wide variety of applications in practice. In this paper, we look at one such queueing model in which the arrivals occur according to …

Ultrafast Laser Direct Writing Of Conductive Patterns On Polyimide Substrate, Ishrat Jahan Biswas, Enrique Contreras Lopez, Farid Ahmed, Jianzhi Li

Manufacturing & Industrial Engineering Faculty Publications and Presentations

Laser direct writing (LDW) is a fast and cost-effective method for printing conductive patterns in flexible polymer substrates. The electrical, chemical, and mechanical properties of polyimide (PI) make it an attractive material choice for laser writing of conductive circuits in such polymer. Electrically insulating PI has shown great potential for flexible printed electronics as LDW enables selective carbonization in the bulk of such material leading to the formation of conductive lines. However, existing studies in this area reveal a few key limitations of this approach including limited conductivity of written structures and fragility of carbonized PI. Therefore, more research is …

A Numerical Study On The Powder Flowability, Spreadability, Packing Fraction In Powder Bed Additive Manufacturing, Yeasir Mohammad Akib, Ehsan Marzbanrad, Farid Ahmed, Jianzhi Li

Manufacturing & Industrial Engineering Faculty Publications and Presentations

The powder bed fusion (PBF) process is widely adopted in many manufacturing industries because of its capability to 3D print complex parts with micro-scale precision. In PBF process, a thermal energy source is used to selectively fuse powder particles layer by layer to build a part. The build quality in the PBF process primarily depends on the thermal energy deposition and properties of the powder bed. Powder flowability, powder spreading, and packing fraction are key factors that determine the properties of a powder bed. Therefore, the study of these process parameters is essential to better understand the PBF process. In …

Synthesizing And Printing Of Tin Oxide Nanoparticles Using A Single Ultrafast Laser System: A Feasibility Study, Enrique Contreras Lopez, Farid Ahmed, Jianzhi Li

Manufacturing & Industrial Engineering Faculty Publications and Presentations

In laser-based manufacturing, processing setup customization is one of the popular approaches used to enhance diversity in material processing using a single laser. In this study, we propose setup design modification of an ultrafast laser system to demonstrate both Tin Oxide (SnO2) nanoparticle synthesis from bulk metal, and post printing of said nanoparticles using Laser Induced Forward Transfer (LIFT) method. Using the Pulse Laser Ablation in Liquid (PLA-L) method, nanoparticles were synthesized from a bulk tin metal cube submerged in distilled water. Such nanoparticles dispersed in water can form colloidal ink that can be used for different printed electronics applications. …

Work Measurement Study, Robert S. Keyser

KSU Distinguished Course Repository

This course consists of an examination of the principles and practices of work analysis and work measurement. Emphasis is on a variety of analytical tools and the development of the student's skill in the use of a video timing device.

Retention Prediction And Policy Optimization For United States Air Force Personnel Management, Joseph C. Hoecherl

Theses and Dissertations

Effective personnel management policies in the United States Air Force (USAF) require methods to predict the number of personnel who will remain in the USAF as well as to replenish personnel with different skillsets over time as they depart. To improve retention predictions, we develop and test traditional random forest models and feedforward neural networks as well as partially autoregressive forms of both, outperforming the benchmark on a test dataset by 62.8% and 34.8% for the neural network and the partially autoregressive neural network, respectively. We formulate the workforce replenishment problem as a Markov decision process for active duty enlisted …

Root-Cause Analysis Of Rsaf Maintenance-Related Flight Safety Mishaps, Heaf H. Alqahtani

Theses and Dissertations

Poor maintenance is a major factor in many aviation mishaps. This is due to the fact that some maintenance activities are carried out improperly or overlooked as a result of human error. It is important to acknowledge that maintenance mistakes are a visible sign of deeper organizational issues. Therefore, adequate solutions to maintenance issues must consider organizational influences. Despite efforts to reduce the accident rate within the Royal Saudi Air Force (RSAF), the RSAF suffers from an increasing trend in mishaps attributed to maintenance. Therefore, safety data was analyzed to examine trends. Additionally, the Human Factors Analysis and Classification System …

Choice-Based Crowdshipping: A Dynamic Task Display Problem, Alp Arslan, Firat Kilci, Shih-Fen Cheng, Archan Misra

Research Collection School Of Computing and Information Systems

This paper studies the integration of the crowd workforce into a generic last-mile delivery setting in which a set of known delivery requests should be fulfilled at a minimum cost. In this setting, the crowd drivers are able to choose to perform a parcel delivery among the available and displayed requests. We specifically investigate the question: what tasks should be displayed to an individual driver, so as to minimize the overall delivery expenses? In contrast to past approaches, where drivers are either (a) given the choice of a single task chosen so as to optimize the platform’s profit, or (b) …

Turning Of Carbon Fiber Reinforced Polymer (Cfrp) Composites: Process Modeling And Optimization Using Taguchi Analysis And Multi-Objective Genetic Algorithm, S. M. Abdur Rob, Anil K. Srivastava

Manufacturing & Industrial Engineering Faculty Publications and Presentations

Carbon Fiber Reinforced Polymer (CFRP) composites have been widely used in aerospace, automotive, nuclear, and biomedical industries due to their high strength-to-weight ratio, corrosion resistance, durability, and excellent thermo-mechanical properties in non-oxidative atmospheres. Machining of CFRP composites has always been a challenge for manufacturers. In this research, a comparative study was performed between the optimal machining parameters of coated and uncoated carbide inserts obtained from the Multi-Objective Genetic Algorithm during turning of CFRP composites. It was found that coated carbide inserts provide lower tool wear and surface roughness, but higher cutting forces compared to those of uncoated carbide inserts …

Automated Posture Positioning For High Precision 3d Scanning Of A Freeform Design Using Bayesian Optimization, Zhaohui Geng, Bopaya Bidanda

Manufacturing & Industrial Engineering Faculty Publications and Presentations

Three-dimensional scanning is widely used for the dimension measurements of physical objects with freeform designs. The output point cloud is flexible enough to provide a detailed geometric description for these objects. However, geometric accuracy and precision are still debatable for this scanning process. Uncertainties are ubiquitous in geometric measurement due to many physical factors. One potential factor is the object’s posture in the scanning region. The posture of target positioning on the scanning platform could influence the normal of the scanning points, which could further affect the measurement variances. This paper first investigates the geometric and spatial factors that could …

Minimax Registration For Point Cloud Alignment, Zhaohui Geng, Mauro Garcia, Bopaya Bidanda

Manufacturing & Industrial Engineering Faculty Publications and Presentations

The alignment, or rigid registration, of three-dimensional (3D) point clouds plays an important role in many applications, such as robotics and computer vision. Recently, with the improvement in high precision and automated 3D scanners, the registration algorithm has become critical in a manufacturing setting for tolerance analysis, quality inspection, or reverse engineering purposes. Most of the currently developed registration algorithms focus on aligning the point clouds by minimizing the average squared deviations. However, in manufacturing practices, especially those involving the assembly of multiple parts, an envelope principle is widely used, which is based on minimax criteria. Our present work …

Evaluating Performance Competencies In The Royal Saudi Air Force Engineering Directorate And Squadrons, Faisal A. Al Dawood

Theses and Dissertations

The effectiveness of tasks performed by the directorate of aeronautical engineering and squadrons in RSAF directly impacts flight safety, which in turn influences the organization either positively or negatively. Therefore, improving engineers' competencies will improve the overall performance of the organization. The study refined and reconstructed a model, namely a T-shape competency model, to assess the engineers' competencies which revealed some management and competency-related deficiencies and concluded with managerial recommendations.

Value Focused Thinking Analysis Of C-Band Australia Radar Operations, Samuel Ray Grothman

Theses and Dissertations

The radars used for Space Domain Awareness (SDA) are inherently all-weather, day/night sensors capable of around the clock operations. Despite this fact, some radars are operated for fewer than their maximum operating capabilities. The decision-making process for selecting the operating hours of a sensor has historically been based on only a few factors or just one. This research uses the techniques in Value Focused Thinking to develop an evaluation process to score possible alternatives and find the alternative with the most value for the decision maker. By investigating the value that is added by operating an SDA radar, it is …

A Methodological Framework For Parametric Combat Analysis, Dustin L. Hayhurst Sr.

Theses and Dissertations

This work presents a taxonomic structure for understanding the tension between certain factors of stability for game-theoretic outcomes such as Nash optimality, Pareto optimality, and balance optimality and then applies such game-theoretic concepts to the advancement of strategic thought on spacepower. This work successfully adapts and applies combat modeling theory to the evaluation of cislunar space conflict. This work provides evidence that the reliability characteristics of small spacecraft share similarities to the reliability characteristics of large spacecraft. Using these novel foundational concepts, this dissertation develops and presents a parametric methodological framework capable of analyzing the efficacy of heterogeneous force compositions …

Ultrafast Laser Ablation Of Inconel 718 For Surface Improvement, Sampson Canacoo, Enrique Contreras Lopez, Oscar Coronel, Farid Ahmed, Jianzhi Li, Anil K. Srivastava

Manufacturing & Industrial Engineering Faculty Publications and Presentations

Inconel 718 is considered difficult to machine because of its ability to maintain its properties at high temperatures. The low thermal conductivity of the alloy causes accelerated tool deterioration when machining. Selective laser melting (SLM) additive manufacturing introduces a possibility of eliminating these difficulties, and producing complex shapes with this difficult-to-machine material. However, high surface roughness and porosity usually occur at the surface of components produced through additive manufacturing. In this study, the surfaces of Inconel 718 samples produced through selective laser melting were treated using laser ablation. The process parameters for the laser ablation process were analyzed in …

Optimizing Incentives For Systems With Heterogeneous Agents, Chen Chen

Dissertations

This dissertation explores new models and applications based on the game theory of incentives. This exploration starts with controlling an invasive insect problem to address one of the most significant challenges facing our forests, the invasion of the Emerald ash borer (EAB), a non-native, wood-boring insect that threatens to kill most ash trees in North America, through designing two new cost-sharing programs between the landowners and local governments. Ash trees are one of North America’s most widely distributed tree genera and a vital part of the green infrastructure of cities, where they provide residents with numerous social, economic, and ecological …

Computation Of Risk Measures In Finance And Parallel Real-Time Scheduling, Yajuan Li

Dissertations

Many application areas employ various risk measures, such as a quantile, to assess risks. For example, in finance, risk managers employ a quantile to help determine appropriate levels of capital needed to be able to absorb (with high probability) large unexpected losses in credit portfolios comprising loans, bonds, and other financial instruments subject to default. This dissertation discusses the computation of risk measures in finance and parallel real-time scheduling.

Firstly, two estimation approaches are compared for one risk measure, a quantile, via randomized quasi-Monte Carlo (RQMC) in an asymptotic setting where the number of randomizations for RQMC grows large, but …

Back And Shoulder Exoskeletons For Occupational Use: A Review, Erkan Ozan

Theses

Work-related musculoskeletal disorders (MSDs) account for a large portion of all work-related injuries according to OSHA. Back and shoulder-related disorders make the most of work-related MSDs according to the Bureau of Labor Statistics (BLS). Exoskeletons emerged in recent years with the potential to reduce the risks of work-related musculoskeletal disorders and injuries. Their use in occupational settings is increasing, and exoskeleton designs are rapidly evolving. This paper reviewed recent scientific articles (2015 and after) that evaluated back and shoulder-support passive industrial exoskeletons. The findings of these articles are summarized and analyzed to assess the benefits of passive upper-body exoskeletons by …