Search Results (1 - 25 of 388 Results)

Sort By  
Sort Dir
 
Results per page  

Bafakeeh, Omar TMicro/Nano Surface Finish Single Side Electrolytic In-Process Dressing (ELID) Grinding with Lapping Kinematics of Sapphire
Doctor of Philosophy, University of Toledo, 2017, Industrial Engineering
The demand for Sapphire ( a-AL2 O3 ) has increased significantly, due to its excellent reliable properties. Sapphire, known for its high hardness and brittleness, has excellent optic, mechanical, and physical properties. Sapphire is used in many different applications such as aerospace, optics, electronics, and in other industries. Machining of sapphire is challenging due to its high hardness and brittleness. The manufacturing of such material is very expensive because the tool wear is very high and longtime machining. Single side grinding is sometimes preferable over conventional grinding because of the ability to provide flat surfaces for ceramic materials. The use of electrolytic in-process dressing (ELID) helps reduce machining time. The use of the kinematics of lapping with the ELID will help reduce machining time in addition to eliminating the use of lapping and polishing. This current study examines five parameters with three levels each. A full factorial design, for both roughness (Ra) and material removal rate (MRR) are be conducted to present mathematical models which predict future results. Three grinding wheels with different mesh sizes are be used. The influence of the grain size on the result will be investigated. The kinematics of the process will be investigated based on the effect of different eccentricities. The parameters used in this study are; different wheel mesh sizes, different pressures, different eccentricities, different spindle speed, and different wheel speed ratios; each of these parameters are in three levels.

Committee:

Ioan Marinescu (Committee Chair); Abdollah Afjeh (Committee Member); Mansoor Alam (Committee Member); Sarit Bhaduri (Committee Member); Matthew Franchetti (Committee Member)

Subjects:

Industrial Engineering; Mechanical Engineering

Keywords:

ELID, Single Side Grinding, Fine Grinding, Sapphire

Merrell, Thomas WilliamEvaluation of Consumer Drone Control Interface
Master of Science in Industrial and Human Factors Engineering (MSIHE) , Wright State University, 2018, Industrial and Human Factors Engineering
The development and use of consumer grade drones is becoming a larger part of our society for many different applications. There has been a great amount of discussion and constant review of proper operation of consumer drones including proper methods of control. In turn, regulation of such devices has been inconsistent. This study aims to better understand the effects of the three primary control interface methods (line of sight, video aided, and first-person view) on flight performance, situational awareness, and perceived mental workload of the operator. Secondarily, this study aims to provide design recommendations for future interfaces. This study shows that the first-person view control interface results in a longer flight time around a course, higher mental workload, and lower situational awareness when compared to line-of-sight and video aided control. The use of line-of-sight control performed superiorly in all areas, and the video-aided interface was very close behind.

Committee:

Subhashini Ganapthy, Ph.D. (Advisor); Mary Fendley, Ph.D. (Committee Member); Sasanka Prabhala, Ph.D. (Committee Member)

Subjects:

Engineering; Industrial Engineering; Neurosciences

Keywords:

usability; mental workload; situational awareness; consumer drone; interface design

Younes Sinaki, RoohollahFinancial Analysis and Global Supply Chain Design : A Case Study of Blood Sugar Monitoring Industry
Master of Science (MS), Ohio University, 2017, Industrial and Systems Engineering (Engineering and Technology)
The main purpose of this thesis is to design a global supply chain network for a pharmaceutical company located in Puerto Rico, which manufactures blood sugar strips products. As a design aspect of supply chain, layered cellular manufacturing systems consist of dedicated, shared and remainder cells are considered. One of the main differences between classical cellular manufacturing systems and layered cellular manufacturing systems is, in layered cellular design, some cells may needed to be utilized by various parts of product families. Depending on the required demand and similarity in essential processes or manufacturing characteristics for each product family, products are grouped together and form a product family. If the product family assigned to one cell and just one product family utilizes that cell, the cell is a dedicated cell. Shared cells and remainder cells are employed by, two families and three or more families, respectively. In the first part of this study, a new heuristic layered-cellular manufacturing design approach is proposed and later in the second part, two mathematical models are proposed. The first one is with the objective of minimizing number of cells and cost of opening cells, and the second one is maximizing Net Present Value considering budget limitations for the whole manufacturing system. In the first step, the required number of cells are determined for a product family to meet an acceptable demand coverage (MADC) percentage. It is assumed that customer demand follows normal distribution with the established parameters mean (µ) and standard deviation (s). An attempt is made to increase the utilization of each cell by combining multiple families (thus creating shared and remainder cells) to increase the utilization of each cell as long as it is economically acceptable. As demand coverage increases, revenue also increases. However, this also increases operational costs. The expected profit is calculated based on the expected cell utilization. Cost analysis approach proposed in this study will allow us to modify cells or open new cells. The results of this heuristic approach and mathematical model are compared. Finally, simulation is employed to verify our proposed layered-cellular system based on evaluating two measurable performance factors: average flow time and work in process inventory.

Committee:

Gursel Suer (Advisor); Tao Yuan (Committee Member); Diana Schwerha (Committee Member); Ashley Metcalf (Committee Member)

Subjects:

Industrial Engineering

Keywords:

Global Supply Chain; Manufacturing System; Cellular Manufacturing; Layered Cellular Design; Integer Programming Model; Heuristic Approach; Simulation Model; Stochastic Demand; Cost Analysis

Martof, Ashley NicoleAnalysis of Business Models for the Use of Additive Manufacturing for Maintenance and Sustainment
Master of Science in Engineering, Youngstown State University, 2017, Department of Mechanical and Industrial Engineering
Aircraft operators must maintain and sustain their aircraft through the platform’s life cycle. The Department of Defense (DoD) is no exception. Many DoD missions may require a time-sensitive production of spare parts. This lends itself to spare parts production by the Department of Defense itself and such an approach could be enabled by additive manufacturing. In order for the government to be able to produce spare parts in-house an entirely new business model between the original equipment manufacturer (OEM) and the government has to be established. A physical spare part would not be the transacted item; instead the technical data package (TDP) would be exchanged. Industry needs to be incentivized to adopt a data focused business model. A key question is can industry achieve equivalent profit similarly to the traditional spare parts production? This research explores business models from the perspective of industry. A survey was provided to both government and industry to identify differences and similarities in assumptions and expectations. Four different business models were developed. The business models were applied to two different case studies to evaluate the pros and cons of the various models. This analysis provides industry and government a reference for discussions on approaches toward future maintenance and sustainment manufacturing operations.

Committee:

Brett Conner, PhD (Advisor); Darrell Wallace, PhD (Committee Member); Martin Cala, PhD (Committee Member)

Subjects:

Business Costs; Engineering; Industrial Engineering; Public Policy

Keywords:

Additive Manufacturing; Business Models; Aerospace and Defense; 3D Printing

Grunden, Eric HansExamination of Rapid Prototype Tooling
Master of Science, The Ohio State University, 2016, Industrial and Systems Engineering
Tooling design is a critical step when designing an injection molding op- eration for a new product. Conventional molds used in injection molding are costly, thus, a considerable amount of detail and time is spent ensuring the tooling will be correct the rst time. In the last three decades rapid prototyping technologies (RP) have become more useful in the product design phase of mold manufacturing. Prototyping components in similar materials and geometries as the nal molded part have seen the lion's share of RP involvement in mold design. Indirect and soft tooling have also bene ted from RP master molds which are manufactured exceedingly faster than traditional physical prototypes. Manufacturing of rapid tool- ing (RT) is expected to be the next signi cant industrial application of RP. Where a traditional mold may take several weeks or even months to machine, a RT mold could be made in hours or days at a fraction of the cost. Signi cantly decreasing the time and cost needed to mold proto- types and or decreasing the cost where only a limited number of parts is required. The objective of this research is to implement a simulation based proce- dure for the validation and analysis of a rapidly prototyped tooling before production. Creating a predictive model will aid in exploring the eld of RT with new materials and various scales of tooling not yet investigated by giving a simple pass/fail critique on designs. To carry out such a model Moldex3D and Dassault's Abaqus were used to simulate the molding pro- cess and internal loading on a RT mold cavity design. By comparing two similar models each with a di erent pass/fail result the simulation results were comparing to experimental results. The comparison of the simula- tion and experimental results demonstrate the validity of the model based approach to establish guidelines to begin the standardization of RT mold designs.

Committee:

jose castro (Advisor); allen yi (Committee Member); rachmat mulyana (Committee Member)

Subjects:

Industrial Engineering

Keywords:

Rapid Prototyping, Rapid Tooling, Additive Manufacturing, FEM, Predictive Model, Moldex3D

Hwang, JaejinTHE DEVELOPMENT OF A PERSONALIZED CURVED MUSCLE MODEL APPLICABLE TO COMPLEX DYNAMIC EXERTIONS
Doctor of Philosophy, The Ohio State University, 2016, Industrial and Systems Engineering
Accurate estimates of trunk muscle geometry including the muscle line of action are essential to the development of biologically-assisted models capable of accurately documenting spinal tissue loads. Currently most biomechanical models of the spine employ straight-line muscle approximations for computational efficiency. However, this straight line of action assumption is thought to violate the physiological reality of the lumbar spine and would provide a wrong estimate of spine tissue loading especially during asymmetric complex exertions. The incorporation of muscle curvature within the biomechanical model has been suggested as a means to more accurately predict spine tissue loads. However, the approach to defining the curved geometry and line of action of the muscle for modeling purposes and the logic associated with integrating this information into current biologically-assisted models have not yet been addressed. Hence, the objective of this study was to develop personalized curved muscle geometry and integrate this information into a biologically-assisted spine model using an individual’s anthropometric measures, trunk kinematics, kinetics, and muscle activities. Four major steps were conducted to meet this goal. First, a systematic literature review was performed and 35 studies met the selection criteria. The most common technique of curved muscle path was the “via-point” method. Curved muscle geometry was commonly developed from MRI/CT database and cadaveric dissections, and inverse dynamics models were typically used to estimate muscle forces. Several models have attempted to examine their results by comparing their approach with previous studies, however, only limited conditions were able to be examined. Second, based on magnetic resonance imaging data from thirty subjects (10 male and 20 female) reported in a previous study, a polynomial regression analysis was conducted to estimate the muscle moment-arms and physiological cross-sectional areas through thoracic/lumbar spine as a function of vertebral level, gender, age, height, and body mass. Third, the model structure was developed to include curved muscle geometry, separation of active and passive muscle forces, and personalization of muscle properties. Lastly, model fidelity of the curved muscle model through the entire lumbar spine was evaluated for 24 subjects (13 males and 11 females) during a wide range of complex dynamic lifting exertions. In general, curved muscle model predicted at least 80% of the variability in spinal moments, and less than 15% of average moment matching error across levels. The compression and anterior-posterior shear load significantly increased as trunk bent more, whereas the lateral shear load significantly increased as trunk twisted more asymmetric during lifting tasks. The results of this study indicate that a curved muscle representation in the biologically-assisted model is an empirically reasonable approach to accurately estimate spinal moments and spinal tissue loads of the lumbar spine. This advancement is expected to help quantify risk exposure more accurately, improve patient health and enable the development of interventions that could mitigate risks in occupational jobs.

Committee:

William Marras (Advisor); Ehud Mendel (Committee Member); Safdar Khan (Committee Member)

Subjects:

Industrial Engineering

Xiao, ZhifuA Comparative Analysis of an Interior-point Method and a Sequential Quadratic Programming Method for the Markowitz Portfolio Management Problem
BA, Oberlin College, 2016, Mathematics
In this paper, I give a brief introduction of the general optimization problem as well as the convex optimization problem. The portfolio selection problem, as a typical type of convex optimization problem, can be easily solved in polynomial time. However, when the number of available stocks in the portfolio becomes large, there might be a significant difference in the running time of different polynomial-time solving methods. In this paper, I perform a comparative analysis of two different solving methods and discuss the characteristics and differences.

Committee:

Robert Bosch (Advisor)

Subjects:

Applied Mathematics; Industrial Engineering; Mathematics; Operations Research

Keywords:

optimization;interior-point method;portfolio optimization;convex optimization;sequential quadratic programming;

Myers, Robert A.Engineering Healthcare Delivery: A Systems Engineering Approach to Improving Trauma Center Nursing Efficacy
Doctor of Philosophy (PhD), Wright State University, 2016, Engineering PhD
The efficacy of nurses is impacted by their availability to their patients and the occurrence of both beneficial and detrimental interruptions. Using system engineering tools, this work addresses open challenges in (i) methods for effective matching of nurse availability to non-stationary stochastic demand, (ii) differentiation of beneficial and detrimental interruptions, and (iii) modeling of nurses’ work with interruptions to provide an objective method of testing interruption interventions. First, we propose both qualitative and quantitative approaches to evaluate and then model the impact of resource scheduling on patient wait time in a Level I trauma center for a highly specialized nurse, the advanced practice provider (APP). Our findings revealed mismatches during evenings and weekends, which prompted the trauma manager to implement a schedule similar to one proposed by our model. This schedule reduced the patent wait time by over 73% at the cost of a 10.5% increase in APP hours. Applying a simulation-optimization approach, we obtained near-optimal schedules that reduced the wait time to over 78% with no increase in APP hours. Second, we proposed a novel patient-centered framework for classifying observed interruptions as detrimental or beneficial. We utilize a mixed-method approach that involved analysis of data collected via direct observation, surveys, and analysis of retrospective data for hands-free devices. With comfort and time as performance measures, we show that beneficial interruptions include those returning the nurse’s focus to the patient, and detrimental interruptions those breaking the delivery of steady treatment or attention to the patient. Finally, using this differentiation, we provide a model of nurse’s workflow with interruptions that captures the underlying stochastic, non-stationary nature of interruptions and their onset through actual observation of trauma center nurses. This model provides a deeper understanding of how interruptions develop from sources with unmet needs, and leads to an objective model based on discrete event simulation for testing interventions. Findings include the dynamics of interruption deferment on other activities, the need for focused interruption interventions rather than across-the-board strategies, and the ratio of beneficial to detrimental interruptions as a novel measure of nurses’ work that may be a useful measure in comparing interventions.

Committee:

Parikh Prakik, Ph.D. (Advisor); Frank Ciarallo, Ph.D. (Committee Member); Jennie Gallimore, Ph.D. (Committee Member); Nan Kong, Ph.D. (Committee Member); Mary McCarthy, M.D. (Committee Member)

Subjects:

Engineering; Health Care; Industrial Engineering; Systems Science

Keywords:

Healthcare delivery; nurse scheduling; interruptions; distractions; stochastic modeling; simulation; patient value; optimization

Saeid, Ali A.Modeling the Progressive Damage in Biomimetic Composite Sandwich T-Joints
Doctor of Philosophy (Ph.D.), University of Dayton, 2016, Mechanical Engineering
Composite sandwich structures are used extensively in aerospace, marine and other industrial applications. This is primarily due to the ability to fabricate lightweight structures with high bending stiffness and strength. A common joint between sandwich panels is a T-Joint, wherein the sandwich panels connect at 90° to each other. Current composite T-joint designs are prone to complex failure modes, including delamination and shear core failure, which significantly reduce the strength of the joints. This dissertation presents a methodology for the design and analysis of composite sandwich T-joints using a biomimetic design approach. It offers unique attributes to optimize the continuous fiber paths for minimum stress concentrations and multi sandwich layers to increase the bending strength. The major attention was to investigate the progressive failure modes in the joints numerically and verify by experiments. Experimental studies were conducted on three different designs of biomimetic composite sandwich T-joints under tension and bending loads. The results show significant improvements to the ultimate load: up to 68% improvement in bending and 40% in pull-off in the biomimetic sandwich T-joints compared to the reference conventional design. Two failure modes were predominant: the initiation and propagation of delamination and core kinking cracks. The finite element models provided important insights into the core failure and delamination. Key parameters of the cohesive zone method for traction-separation laws of multi-interface materials were developed and used to track the crack growth. The results predicted the onset, propagation, and ultimate failure consistent with the experimental observations.

Committee:

Steven Donaldson (Committee Chair)

Subjects:

Design; Engineering; Industrial Engineering; Mechanical Engineering

Keywords:

composite sandwich T-joints; biomimetic approach; multiple delamination; fracture modes; cohesive zone method; finite element analysis

Park, SanghyunInvestigating the Impacts of Barriers and Facilitators Affecting the Adoption of Lifting Devices in Health Care Facilities
Doctor of Philosophy, The Ohio State University, 2015, Industrial and Systems Engineering
The long term goal of this study is to prevent work-related musculoskeletal disorders associated with physically demanding activities through the adoption of an ergonomics intervention. The adoption was considered a process that involves multiple stages of behavioral change towards intervention use based on the Stages of Change Model. Factors believed to affect an individual's adoption stage were examined for their positive impact as a facilitator or negative impact as a barrier. The current study was conducted in the context of health care workers' adoption of a lifting device. The aims of this study were to (1) develop a survey instrument that could be used to assess adoption stages of a lifting device and categorize the barriers and facilitators, (2) identify key factors that differentiate between stages and (3) develop adoption models that classify an individual's adoption stage based upon that individual's response to selected factors. This study used a survey instrument to assess individuals' adoption stages and to assess factors that potentially affect individuals at each adoption stage in specific resident-handling situations where a lifting device with a full-body sling is recommended to use by The National Institute for Occupational Safety and Health. These situations include the following: Situation 1 represented the transfer of a non-cooperative resident that was able to partially bear weight, Situation 2 represented the transfer of a cooperative resident unable to bear weight, and Situation 3 focused on repositioning a patient. Survey data were collected from 297 healthcare professionals in 12 skilled nursing facilities. Based on reported frequency of use and intention to use a lift device, an individual was classified as a full adopter, partial adopter, trial user, contemplator, pre-contemplator, or non-adopter. The results indicate that the distribution of adoption stages varies by resident-handling situation. In Situation 1, participants were evenly distributed over the adoption stages. In Situation 2, a majority of participants were identified as full adopters. In Situation 3, a majority of participants were pre-contemplators with no intention of lift use. A frequency analysis of survey responses indicated that participants' endorsement of factors varied by adoption stage and by situation. In Situations 1 and 2, in comparison to partial adopters and trial users (the PT group), full adopters agreed more with multiple categories of facilitators, including organizational facilitators, colleague behaviors, perceived ergonomic advantages, and how residents would benefit from device use. Barriers affecting the PT group were their perceived physical capability for manual transfer and availability of other, preferred transferring methods. In Situation 1, the PT group (in comparison to contemplators) endorsed the facilitators of personal safety concern, colleague support, and perceived benefits of lift use to a resident. Contemplators were affected by the barriers of resident safety concerns and a conflict between lift use and resident therapy regime. Conversely, in Situation 3, results from a comparison between contemplators and pre-contemplators were demonstrated with multiple categories of facilitators perceived by contemplators. In Situation 1, a discriminant function analyses and a frequency analysis demonstrated consistent results. The predictor that exhibited the greatest effect on differentiating full adopters from the PT group was a combination of physical capability for manual transfer and preference of other transferring methods rather than a lifting device (for the PT group), followed by protocol of lift use and managerial encouragement (for the full adopters). Predictors that exhibited at least moderate effect on differentiating the PT group from contemplators were colleague support (for the PT group) and a combination of concern for resident safety and difficulty in putting a sling under a resident (for the contemplators). A model that differentiated between contemplators and pre-contemplator indicated that the strongest predictor for contemplators was concern for personal safety. In Situations 2 and 3, the adopter group (including full and partial adopters) was differentiated from non-users. The smoothness of resident-handling tasks was a common predictor endorsed by the adopters, while the perception of physical capability for manual transfer and preference of other transferring method rather than lift use were indicated as barriers of non-users (contemplators and pre-contemplators). In conclusion, this study demonstrated the applicability of the Stages of Change Model in illuminating the adoption process of a lifting device. Quantitative approaches were used to indicate key facilitators and barriers in order to classify adoption stages. Overall, the acceptance of manual transfer was a prevalent barrier, while positive attitudes toward lift use appeared to be formed by the combined effect of multiple facilitators.

Committee:

Steven A. Lavender (Advisor); Carolyn M. Sommerich (Committee Member); Emily S. Patterson (Committee Member)

Subjects:

Industrial Engineering

Keywords:

adoption; ergonomics intervention; facilitator; barrier; nursing home; health care facility; Stages of Change Model; Transtheoretical Model; mechanical lifting device; macro ergonomics; discriminant function analysis; patient-handling activity

Church, Donald GlenReducing Error Rates in Intelligence, Surveillance, and Reconnaissance (ISR) Anomaly Detection via Information Presentation Optimization
Master of Science in Industrial and Human Factors Engineering (MSIHE) , Wright State University, 2015, Industrial and Human Factors Engineering
In the ISR domain, time-critical decision-making and dealing with multiple information feeds places high demands on the human. When designing aids and tools, the decision maker must be taken into account. This research looks toward designing a decision aid based the personality type of the operator. The BFI is used to determine the impact of personality and decision aid type (graphical vs. textual) on performance. Results show Openness and Agreeableness to be the strongest single factors for decision aid impact on performance. A model was also developed to show how the human takes the information and relates it to a mental model for use in making an identification. This can assist the ISR community in developing an adaptive aiding system to reduce the cycle time in the decision making process and have the greatest impact on performance.

Committee:

Mary Fendley, Ph.D. (Advisor); Richard Warren, Ph.D. (Committee Member); Pratik Parikh, Ph.D. (Committee Member)

Subjects:

Engineering; Industrial Engineering; Information Technology; Personality Psychology

Keywords:

Personality; BFI; Big Five; ISR; Intelligence; Surveillance; Reconnaissance; SDT; Signal detection; visual aid; graphical aid; textual aid; interface design; perception; cognitive fit; perception model; information processing; human factors

Coral, Melissa PatriciaAnalyzing Cognitive Workload Through Eye-related Measurements: A Meta-Analysis
Master of Science in Industrial and Human Factors Engineering (MSIHE) , Wright State University, 2016, Industrial and Human Factors Engineering
Understanding cognitive workload has become a vital topic for researchers in developing future systems. Existing research has investigated the use of physiological measurements of the eye with cognitive workload, though a quantitative synthesis has yet to be performed. A meta-analysis was conducted to examine the effects of cognitive workload on eye-related measurements. The objective of this meta-analysis is not to determine a difference between the levels of workload, but to identify reliable measurements. Measurements through blinks, saccades, pupils, and fixations were examined. Twenty-two studies, contributing to a total of sixty entries, met the appropriate inclusion criteria for the meta-analysis. Findings conclude the use of specific eye-related measurements as a reliable assessment of cognitive workload. Similar results obtained for moderator variables of task type and eye-tracking system did not indicate significant influences. Further research should be conducted in this domain to identify causal influences and provide an understanding for the results.

Committee:

Mary Fendley, Ph.D. (Advisor); Frank Ciarallo, Ph.D. (Committee Member); Trevor Bihl, Ph.D. (Committee Member)

Subjects:

Engineering; Industrial Engineering

Keywords:

industrial engineering;engineering

McMahon, Connor E.Dynamic Assignment Heuristic Utilizing Patient Transporter Locations in Hospitals
Master of Science (MS), Ohio University, 2015, Industrial and Systems Engineering (Engineering and Technology)
Within a hospital, patients require the assistance of transporters to be moved to and from their scheduled appointments. Requests for transport occur continuously throughout the day in various units of the hospital. If patients arrive late to their appointments, both hospital efficiency and patients’ perceived quality of care could be negatively impacted. The aim of this research is to provide a solution for the problems arising from inefficient transporter assignments in order to reduce patient inconvenience and improve resource utilization. Expected transporter location information is utilized to provide greater accuracy and flexibility for job assignments. The heuristic provides a quick and efficient assignment strategy for transporter requests in a dynamic environment. The model is tested on real data provided by a large medical center in Pennsylvania. For typical staffing levels, the heuristic demonstrated an 8-10% reduction in average patient wait time per request. Results show the heuristic was capable of reducing patient wait time without increasing the number of transporters on staff.

Committee:

Dale Masel (Advisor)

Subjects:

Industrial Engineering

Keywords:

healthcare; transporters; heuristic

Lipkin, IlyaTesting Software Development Project Productivity Model
Doctor of Philosophy in Manufacturing and Technology Management, University of Toledo, 2011, Manufacturing and Technology Management

Software development is an increasingly influential factor in today’s business environment, and a major issue affecting software development is how an organization estimates projects. If the organization underestimates cost, schedule, and quality requirements, the end results will not meet customer needs. On the other hand, if the organization overestimates these criteria, resources that could have been used more profitably will be wasted.

There is no accurate model or measure available that can guide an organization in a quest for software development, with existing estimation models often underestimating software development efforts as much as 500 to 600 percent. To address this issue, existing models usually are calibrated using local data with a small sample size, with resulting estimates not offering improved cost analysis.

This study presents a conceptual model for accurately estimating software development, based on an extensive literature review and theoretical analysis based on Sociotechnical Systems (STS) theory. The conceptual model serves as a solution to bridge organizational and technological factors and is validated using an empirical dataset provided by the DoD.

Practical implications of this study allow for practitioners to concentrate on specific constructs of interest that provide the best value for the least amount of time. This study outlines key contributing constructs that are unique for Software Size E-SLOC, Man-hours Spent, and Quality of the Product, those constructs having the largest contribution to project productivity. This study discusses customer characteristics and provides a framework for a simplified project analysis for source selection evaluation and audit task reviews for the customers and suppliers.

Theoretical contributions of this study provide an initial theory-based hypothesized project productivity model that can be used as a generic overall model across several application domains such as IT, Command and Control, Simulation and etc¿¿¿ This research validates findings from previous work concerning software project productivity and leverages said results in this study. The hypothesized project productivity model provides statistical support and validation of expert opinions used by practitioners in the field of software project estimation.

Committee:

Jeen Su Lim (Committee Chair); James Pope (Committee Member); Michael Mallin (Committee Member); Michael Jakobson (Committee Member); Wilson Rosa (Advisor)

Subjects:

Aerospace Engineering; Armed Forces; Artificial Intelligence; Business Administration; Business Costs; Computer Engineering; Computer Science; Economic Theory; Economics; Electrical Engineering; Engineering; Industrial Engineering; Information Science; Information Systems; Information Technology; Management; Marketing; Mathematics

Keywords:

"Software Estimation"; "Software Cost Model"; "Department of Defense Data"; COCOMO; "Software Project Productivity Model"

Kothawade, Manish A Bayesian Method for Planning Reliability Demonstration Tests for Multi-Component Systems
Master of Science (MS), Ohio University, 2014, Industrial and Systems Engineering (Engineering and Technology)
The objective of this research is to develop a methodology to plan a zero-failure reliability demonstration test (RDT) for multi-component systems. A fully Bayesian hierarchical approach is applied to model multi-level systems, with independent components. The system failure time distribution is expressed according to the component failure time distributions based on the system structure determined by the reliability block diagram. Component-level prior information is incorporated into a joint prior distribution. Markov chain Monte Carlo methods, such as Gibbs sampling, are developed to find the minimum sample size for planning the system RDT.

Committee:

Tao Yuan (Advisor); Diana Schwerha (Committee Member); Gary Weckman (Committee Member); William Young (Committee Member)

Subjects:

Engineering; Industrial Engineering; Mathematics; Statistics

Keywords:

Bayesian method; planning of test; reliability demonstration test; zero failure; quantile life; optimal sample size; RDT; component-level data; hierarchical approach

Lopetegui Lazo, Marcelo AInter-Observer Reliability Assessments in Continuous Observation Time Motion Studies
Master of Science, The Ohio State University, 2014, Public Health
Understanding clinical workflow is critical for researchers and decision makers in healthcare. Continuous observation time motion studies (TMS) enhance clinical workflow studies by providing quantitative data required for in-depth analyses. However, methodological inconsistencies have been reported in continuous observation TMS, potentially reducing the validity of TMS’ data and limiting their contribution to the general state of knowledge. Among the major concerns, the lack of methods to ensure the reliability of human observers stands as a priority. We aimed to contribute to workflow research by studying current Inter-Observer Reliability Assessment (IORA) methods in continuous observation TMS, particularly workflow time studies. We reviewed the current practices, assessed the suitability and limitations, bringing awareness of the limitations of the single-dimensionality evaluation methods. We proposed and validated a first contribution towards a comprehensive and meaningful IORA methodology: a composite IORA protocol evaluating agreement in multiple dimensions (proportion, naming, duration, sequence and timing), providing useful information for observers’ training and a meaningful quantitative IORA report. Applicability in multi-tasking and multi-focus models is the next step in IORA research, finally aiming at a meaningful and valid time motion-driven workflow analysis methodology.

Committee:

Po-Yin Yen, PhD, RN (Committee Co-Chair); Haikady Nagaraja, PhD (Committee Member); Peter Embi, MD, MS (Committee Chair); Philip Payne, PhD (Committee Member)

Subjects:

Health Care; Health Care Management; Industrial Engineering; Medicine; Statistics

Keywords:

Inter-observer reliability; time motion studies; standardization

Steele, Samantha L.Animation as an Effective Tool for Communication: A Digital Prototype for Midwest Alive
Master of Fine Arts, The Ohio State University, 2003, Industrial, Interior Visual Communication Design
This project displays how a designer uses animation to convey multiple complex layers of time-based information concurrently through the use of functional and visually engaging graphics rather than static text and images. This project consists of developing a combination of visual graphics such as a web interface, linear 2D animation and 3D animation, an interactive timeline, and a virtual environment. In order to develop these displays successfully, the project also consists of establishing design criteria that are applied to this project and can be referenced for projects of a similar scope. The visual displays developed are used to better explain early roadway development in the Midwest using computer animation rather than static mediums. This is done to take advantage of the ability to layer and cross-reference pertinent material in order to better communicate the process of how, over time, trails were formed and how those trails became major roads and highways throughout the Midwest. This project also shows how early roads influenced the path direction and development of later roads. The project focuses on the first major thoroughfare in Ohio, called Zane’s Trace, and how that route influenced the development of the National Road, State Route 40, and finally 1-70, all of which opened up the Ohio country and the land west of it to exploration, trade and settlement. This visual representation will be the first in a series of interactive and linear works, used specifically by Midwest Alive, a group responsible for creating graphics for the Encyclopedia for the Midwest. The project can be viewed on the CD-ROM included with this document and online at the existing Encyclopedia of the Midwest website (http://www.allmidwest.org).

Committee:

Maria Palazzi (Advisor); Peter Chan (Committee Member); Christian Zacher (Committee Member)

Subjects:

Industrial Engineering

Gimenez, Jose LuisCorporate visual identity: a graphic design analysis
Master of Arts, The Ohio State University, 1981, Industrial and Systems Engineering

Committee:

Peter Kegert (Advisor)

Subjects:

Industrial Engineering

Milecki, Heather H.Virtual Agent Interaction – Improving Cognitive Abilities and Trust for a Complex Visual Search Task
Master of Science in Industrial and Human Factors Engineering (MSIHE) , Wright State University, 2015, Industrial and Human Factors Engineering
Introduction: This thesis research examined a novel decision support aid ("Spatial Cue + Virtual Agent") on human performance in a simulated complex visual search task. Method: Participants in the “Control” condition did not receive support from an aid. Participants in the “Spatial Cue” condition received support from an aid in the form of a bounding box. Participants in the “Spatial Cue + Virtual Agent” condition received support from an aid in the form of a bounding box and a virtual agent. The aids’ reliability was held constant at one level, 70 percent. Image difficulty was based on clutter; clutter was manipulated by varying image white space. Results: The "Spatial Cue + Virtual Agent" improved participants’ Probability of Detection, sensitivity, trust, and confidence. Discussion: This study indicates that there is a potential to mitigate declines in automation trust by simply increasing aids’ humanness.

Committee:

Jennie Gallimore, Ph.D. (Advisor); Subhashini Ganapathy, Ph.D. (Committee Member); Alissa Golden, Ph.D. (Committee Member)

Subjects:

Cognitive Psychology; Experimental Psychology; Industrial Engineering

Keywords:

cognitive psychology;experimental psychology;industrial engineering

Park, Joon BooTheoretical and Experimental Analysis of Residual Stress Formation after Implant Resistance Welding of Polycarbonate
Doctor of Philosophy, The Ohio State University, 1992, Welding Engineering
Formation of residual stress during thermoplastic welding causes detrimental effects to the joint quality under both dynamic and static loading conditions. Residual stress can reduce the solvent resistance of polymers as well as the tensile strength and fatigue life of the joint. Therefore, it is vital to predict and measure the level of residual stresses. Here, the formation of thermal and residual stresses during implant resistance welding of polycarbonate was studied. Thermocouples and an infrared temperature sensor were used to measure the temperature history and temperature distribution in the parts during welding. Heat flow analysis during implant resistance welding was done using Finite Element Method (FEM) and Finite Difference Method (FDM) which are connected with FEM and a simplified modeling analysis so-called "multi-bar analogy" respectively for stress analysis. FEM and FDM predictions of heat flow analysis were in good agreement with experimental measurements. The formation of thermal and residual stress was predicted using 2-D finite element analysis and multi-bar analogy in conjunction with non-isothermal linear viscoelasticity for a thermorheologically simple material. The residual stresses in the parts were measured using both photoelasticity and moire interferometry. Sectioning method utilizing moire interferometry was used to measure residual stress. FEM prediction of residual stress was in good agreement with photoelasticity measurement and moire interferometry measurement. Residual stress formation in the weld was predicted by multi-bar analogy modeling analysis and multi-bar analogy prediction was in good agreement with FEM prediction. Heat treatment to reduce residual stress after welding was performed. Residual stress distribution after heat treatment was predicted using FEM. The FEM prediction was in good agreement with photoelasticity measurement and moire interferometry measurement. This methodology for prediction, measurement and reduction of residual stress can be incorporated into the design, analysis, and welding procedures for plastic and composite joints. This will result in stronger and more reliable welds.

Committee:

Avraham Benatar (Advisor); C. Tsai (Committee Member); M Liou (Committee Member)

Subjects:

Industrial Engineering

Shaik, Muneeb Ur RahmanGas Dispersion Using an Up-Pumping Maxflo W Impeller
Master of Science (M.S.), University of Dayton, 2014, Chemical Engineering
Despite known advantages of up-pumping wide-blade axial-flow impellers for gas dispersion, little is known about the design guidelines of these impellers. In the present study, the gas dispersion capabilities of the up-pumping axial-flow Maxflo W impeller in low-viscosity liquids have been characterized to incorporate effects of scale and system geometry. Further, a comparison is made with the dispersion performance of an up-pumping pitch-blade turbine and a radial-flow CD-6. This comparison showed that the up-pumping Maxflo W impeller have dispersion speed, torque and power requirements relatively independent of the gas flow rate, providing the ability to handle varying process conditions. Testing at three scales (tank diameters of 0.29 m, 0.44 m and 0.60 m) indicates that the dispersion capabilities of the up-pumping Maxflo W can be described in terms of a scale-independent aeration number - Froude number relationship. Although a minimum impeller rotational speed is required to disperse low gas flows, the increase in dispersion speed is small with increasing gas flow rate. The effects of geometric parameters such as impeller to tank diameter ratio, sparger size and ungassed liquid height on flooded to dispersed conditions have been investigated. Unlike radial-flow gas dispersion impellers that are not strongly affected by some geometric parameters, the up-pumping Maxflo W dispersion performance is strongly dependent on system geometric parameters. Additionally, small impeller to tank diameter ratios of Maxflo W impellers have been found to perform poorly in gas dispersion operations because of their highly axial discharge flow. It was found that the up-pumping pitched-blade turbine exhibits time-dependent dispersion behavior that can permanently fail to disperse gas after appearing to be capable of dispersion for a reasonably long period of time. For this reason, collection of design data required extended and meticulous testing.

Committee:

Kevin Myers, J. (Advisor); Eric Janz, E. (Committee Co-Chair); Robert Wilkens, J. (Committee Member)

Subjects:

Chemical Engineering; Fluid Dynamics; Industrial Engineering

Keywords:

Gas Dispersion; Up-pumping Axial-Flow Impeller Scale Effect and Geometrical Effect; Maxflo W; Mixing Scale-up Creteria

Mehta, Jay PareshUnderstanding Behavioral and Physiological Changes associated with Repetitive Lifting and Vibration Exposure
Doctor of Philosophy, The Ohio State University, 2013, Industrial and Systems Engineering
Repetitive manual lifting and whole body vibration (WBV) exposure encountered in manual handling and delivery type jobs lead to muscle fatigue and are documented risk factors for low back disorder (LBD). In order to compensate for muscle fatigue, people in these occupations may adapt their working strategy to prevent an injury. The goal of this dissertation research was to identify the interactive effects of WBV and repetitive lifting exposures on muscle fatigue and changes in lifting mechanics. Study 1 investigated the effects of prolonged repetitive asymmetric lifting task on behavioral adaptations, measures of tissue oxygenation, and spine kinematics during a controlled flexion-extension motion task. Seventeen healthy volunteers repeatedly lifted a box (15% of the participant’s lifting capacity) positioned in front of them at ankle level to a location on their left side at waist level at the rate of 10 lifts/minute for 60 minutes. The results showed that this prolonged lifting task lead to decrease in tissue oxygenation measures and an increase in the level of perceived exertion over time. Behavioral changes with repetitive lifting task included an increase in forward bending motions and velocities in the sagittal and coronal plane. Behavioral measures that increased over time have also been documented to increase the risk of back injury. Study 2 investigated the interactive effects of seated vibration exposure and lifting task precision demands on behavioral and physiological changes experienced during a repetitive lifting task. This study was a 2 x 2 repeated measures design with two levels of vibration exposure and two levels of lifting task precision demands. The initial analyses showed no significant interaction between WBV exposure and task precision demands during the repetitive lifting task. Thus, the data was separately analyzed to understand changes in the physiological and behavioral responses associated with each of these physical factors. Study 2a focused on the changes in the physiological and behavioral responses to repetitive asymmetric lifting activity after seated exposure to a 5 Hz WBV for one-hour. The changes in muscle physiology and behavioral measures replicated the findings from study 1. Following exposure to WBV, participants showed larger spine twisting motion and movement velocity as they performed the lifting task. The larger spine kinematic response indicated these changes would increase the risk of back injury. Study 2b focused on the effect of task precision demands during a repetitive asymmetric lifting task on muscle physiology and behavioral measures. High precision demands resulted in significantly higher movement times, larger sustained twisting motions and lateral bending moments on the spine. These behavioral changes suggest that the risk to low back injury is elevated while performing a repetitive asymmetric lifting activity under high task precision demands. In summary, this research has shown that the risk of low back injury while performing a repetitive asymmetric lifting activity is likely due to changes in the adopted behavior. Moreover, this risk is further elevated when people are exposed to WBV prior to lifting, and when the lifting requires the object be placed in precise location at its destination.

Committee:

Steven Lavender, PhD (Advisor); Carolyn Sommerich, PhD (Committee Member); Richard Jagacinski, PhD (Committee Member)

Subjects:

Industrial Engineering

Keywords:

Repetiitve Lifting; whole body vibration; fatigue; task precision demands; biomechanics; adaptations; low back pain

You, DanyuRe-engineering the Legacy Software Systems by using Object-Oriented Technologies
Master of Science (MS), Ohio University, 2013, Industrial and Systems Engineering (Engineering and Technology)
A legacy system refers to the software system that was developed a long time ago and is still in service. Due to lack of documentations as well as the outdated structure, it is often costly to maintain the legacy systems. Re-engineering a legacy system mainly focuses on improving quality and maintainability of the existing system by introducing new designs. In this research, object-oriented software technologies based methodology was proposed to re-engineer the legacy system, which was implemented with non-object-oriented structure, to achieve better flexibility and maintainability. Object-oriented design patterns are studied to provide flexible and reliable solution for common problems that are confronted in implementing. The clustering technologies are used to discover similar patterns shared by various functions therefore providing the guidance on class design. Unified Modeling Language (UML) provides standard and graphical representations for describing and documenting system design. In the case study, the proposed methodologies are successfully applied to re-engineer the Multicorp legacy system. Results indicate that objected-oriented methodologies help improve system flexibility, usability, maintainability and extendibility; clustering technologies help detect some structural patterns from existing systems, but did not generate complete and acceptable solutions.

Committee:

Dusan Sormaz, Dr. (Committee Chair); Yuan Tao, Dr. (Committee Member); David Koonce, Dr. (Committee Member); Thom Luce, Dr. (Committee Member)

Subjects:

Industrial Engineering

Keywords:

Software Re-engineering; Legacy System; Object-Oriented Modeling; Clustering Technologies

Demiralp, YurdaerDetermination of Material Properties and Prediction of Springback in Air Bending of Advance High Strength Steel (AHSS) and Commercially Pure Titanium (CP) Sheet Materials
Master of Science, The Ohio State University, 2012, Industrial and Systems Engineering

The design of lightweight sheet metal part components requires an understanding of material characteristics and their manufacturing processes. Increasing use of Advance High Strength Steels (AHSS) and Commercially Pure (CP) titanium sheets accompanied by many challenges due to their unique mechanical properties and low formability. Thus, developing fundamental understanding of mechanical properties is critical for successful process and tool design. FE simulations are powerful tool in identification of challenges in forming of these materials and product realization. Therefore, FE model inputs, including flow stress data, play important role for obtaining accurate results. However, obtaining the flow stress curve near production conditions (state of stress strain) might be challenging and requires material characterization test that emulates near production conditions. In this study, uniaxial tensile and biaxial Viscous Pressure Bulge (VPB) tests were conducted at room temperature to obtained material properties and flow stress for sheet materials:

• DP780 (AHSS) (Thickness= 1 mm) • CP-Ti (Grade: 2) = Material A (Thickness = 1.8 mm and heat lot = HT 884971-02-00) • CP-Ti (Grade: 2) = Material B (Thickness = 0.5 mm and heat lot= KX16EM) • CP-Ti = Material C (Thickness = 1 mm and heat lot = W58KEM) Flow stresses obtained from tensile and VPB tests were compared. The strain ratios (R-values) were determined by conducting tensile tests and they were used to correct flow stress curves that obtained from VPB test for anisotropy. In VPB test, it is obvious that flow stress data can be obtained to higher strain values compared to tensile tests. Therefore, the state of stress strain from VPB test emulates real sheet metal forming conditions where process is almost always biaxial. The objective of this study was to predict springback angles in air bending process by using flow stress curves that obtained from both tensile and VPB tests. Air bending process was successfully simulated using FE software DEFORM2D. The results of actual air bending tests and FE simulations, that were conducted by using flow stress curve obtained from both tensile and VPB tests, were compared. In prediction of inner bending angles after unloading and springback angles, FE simulations using flow stress curve obtained from VPB tests gives better results than flow stress curve obtained from tensile tests.

Committee:

Taylan Altan, Dr. (Advisor); Jerald Brevick, Dr. (Committee Member); Prasad Mokashi, Dr. (Committee Member)

Subjects:

Industrial Engineering

Keywords:

Air bending; Commercially pure titanium sheets; Advanced high strength steel

Goel, SaumyaDynamic Probabilistic Lot-Sizing with Service Level Constraints
Master of Science, The Ohio State University, 2011, Industrial and Systems Engineering
We consider inventory control problems with stochastic demand in which a specific service level must be met. We assume that demand and cost distributions over the planning horizon are finite, discrete and non-stationary. We formulate this problem as a chance-constrained program, whose deterministic equivalent is a large-scale mixed-integer program (MIP). We study the structure of the formulations and develop methods for solving them efficiently. We add mixing cuts to tighten these formulations and propose new valid inequalities. We also decompose these large-scale mixed integer programs using Benders decomposition technique and branch-and-price-and-cut method, both of which could incorporate mixing cuts to improve their performance.

Committee:

Simge Küçükyavuz (Advisor); Marc Posner (Committee Member); Suvrajeet Sen (Committee Member)

Subjects:

Industrial Engineering; Operations Research

Keywords:

Stochastic programming; mixed integer programming; large scale programming; production planning

Next Page