Engineering Commons^™

Behavioral Operations Management In Federal Governance, Frederick Leonard Mobley

Walden Dissertations and Doctoral Studies

The environmental uncertainty of federal politics and acquisition outsourcing in competitive markets requires an adaptive decision-analysis structure. Practitioners oriented toward exclusively static methods face severe challenges in understanding qualitative aspects of organizational governance. The purpose of this grounded theory study was to examine and understand behavioral relationship attributes within intuitive, choice, judgment, or preference decision-making processes. The problem addressed in this study was the detrimental effects of organizational citizenship behavior (OCB), compulsory citizenship behavior (CCB), and social exchange theory (SET) on the acquisition management relationship The OCB, CCB, SET dictates that sound business development, relationship acumen, emotional intelligence and perceptiveness …

Strategies To Minimize The Impact Of Supply Chain Risk On Business Performance, Jonathan Opata

Walden Dissertations and Doctoral Studies

The exposure of companies to turbulence, uncertainty, and vulnerability in their supply chain results in supply chain disruption with an estimate cost of $10 million for each supply chain disruption. The purpose of this case study was to explore the strategies supply chain managers use to mitigate supply chain disruption on business performance in a pharmaceutical company in Maryland. Contingency theory of fit formed the conceptual framework for this study. Participant perceptions were elicited in interviews with 11 supply chain managers regarding strategies to mitigate risks associated with supply chain disruptions. Data from interviews and supporting documents were processed and …

An Agent Based Approach For Simulating Demo Enterprise Models, Mamadou Seck, Joseph Barjis

Engineering Management & Systems Engineering Faculty Publications

DEMO (design and engineering methodology for organization) is a theoretically grounded methodology for rigorous enterprise modeling. It provides relevant concepts from a construction perspective. As the methodology gains a wider audience, there is a growing interest in simulating DEMO models. Most attempts to develop a simulation approach for enterprise models in general, and the DEMO methodology in particular, are based on process oriented conceptualizations that are typically implementation in a discrete event paradigm. In this paper, we propose a conceptual framework for the translation of DEMO models into an agent based simulation. We will describe the DEMO methodology in some …

Designing A Portfolio Of Parameter Configurations For Online Algorithm Selection, Aldy Gunawan, Hoong Chuin Lau, Mustafa Misir

Research Collection School Of Computing and Information Systems

Algorithm portfolios seek to determine an effective set of algorithms that can be used within an algorithm selection framework to solve problems. A limited number of these portfolio studies focus on generating different versions of a target algorithm using different parameter configurations. In this paper, we employ a Design of Experiments (DOE) approach to determine a promising range of values for each parameter of an algorithm. These ranges are further processed to determine a portfolio of parameter configurations, which would be used within two online Algorithm Selection approaches for solving different instances of a given combinatorial optimization problem effectively. We …

Modeling And Analysis Of Automated Storage And Retrievals System With Multiple In-The-Aisle Pick Positions, Faraz Ramtin

Electronic Theses and Dissertations

This dissertation focuses on developing analytical models for automated storage and retrieval system with multiple in-the-aisle pick positions (MIAPP-AS/RS). Specifically, our first contribution develops an expected travel time model for different pick positions and different physical configurations for a random storage policy. This contribution has been accepted for publication in IIE Transactions (Ramtin & Pazour, 2014) and was the featured article in the IE Magazine (Askin & Nussbaum, 2014). The second contribution addresses an important design question associated with MIAPP-AS/RS, which is the assignment of items to pick positions in an MIAPP-AS/RS. This contribution has been accepted for publication in …

Engineered Surface Properties Of Porous Tungsten From Cryogenic Machining, Julius M. Schoop

Theses and Dissertations--Chemical and Materials Engineering

Porous tungsten is used to manufacture dispenser cathodes due to it refractory properties. Surface porosity is critical to functional performance of dispenser cathodes because it allows for an impregnated ceramic compound to migrate to the emitting surface, lowering its work function. Likewise, surface roughness is important because it is necessary to ensure uniform wetting of the molten impregnate during high temperature service. Current industry practice to achieve surface roughness and surface porosity requirements involves the use of a plastic infiltrant during machining. After machining, the infiltrant is baked and the cathode pellet is impregnated. In this context, cryogenic machining is …

Machining Strategies Exploring Reduction In Energy Consumption, Abdullah Al Mamun

All Graduate Theses, Dissertations, and Other Capstone Projects

The main aim of this thesis is to explore machining strategies, analyzing energy consumption using Design of Experiments (DOE) at the material removal rate (MRR), compare to cutting geometrical trajectories according to CNC parameters such as spindle RPM, feed rate, depth of cut per pass and total depth of cut. Spindle RPM, depth of cut per pass, and feed rate are selected as the main three factors and each factor has two levels: low-level (-) and high-level (+). These experiments have been performed at an end-milling machine by using a concept of a constant volume of material removal processes in …

Color Removal From Pulp Mill Effluent Using Coal Ash Produced From Georgia Power Coal Combustion Plants, Christopher B. Willett

College of Graduate Studies: Theses & Dissertations

Two environmental concerns currently face Georgia: coal fly ash (CFA) waste from coal power plants, and the effluent generated by pulp mills. Pulp mill effluent discolors surface waters into which it is discharged, and has been proven to negatively impact the dissolved oxygen and carbon necessary for aquatic life. The proposed solution is a cost-effective adsorption treatment using an inexpensive but abundantly available waste material: CFA. CFA possesses beneficial properties that allow it to effectively remove contaminants, and is available at significantly reduced cost. The primary research objective was to define treatment parameters that would result in the maximum removal …

Clinical Significance Of Response Shift In A Spine Interventional Clinical Trial, Robin Carlson

Walden Dissertations and Doctoral Studies

The effectiveness of treatments for degenerative spine conditions, where the primary symptom is back pain, is typically determined using patient-reported quality of life (QoL) measures. However, patients may adjust their internal standards when scoring QoL based on factors other than their health. This response shift phenomenon could confound the interpretation of study data and impact effectiveness conclusions. In the current study, response shift was examined using structural equation modeling (SEM) and previously collected clinical trial data comparing 2 minimally invasive medical devices in lumbar spinal stenosis patients through 1 year postintervention. In subject QoL results, reprioritization shift between 3 months …

Bus Rapid Transit (Brt) Toolbox: Brt Person Throughput-Vehicle Congestion Tradeoffs, Li Jingquan, H.-S. Jacob Tsao, Ching-Yao Chan, Kun Zhou, Wei-Bin Zhang

Faculty Publications

This report documents a research effort to understand the current practice and issues associated with Bus Rapid Transit (BRT) planning and deployment. It reviewed the design options incorporated into existing BRT deployments across California and the nation. The project team interviewed practitioners of California Department of Transportation (Caltrans) Districts and transit agencies to understand the BRT project approval decision-making process, the impacts of BRT implementation and the Measures of Effectiveness (MOEs) for transit and non-transit system performance. The studies revealed that though Caltrans and transit agencies do use a similar set of MOEs for the evaluation of BRT projects, the …

A General Intuitive Design Pattern For Optimally Sequencing Treatment Combinations In 2k Factorial Experiment And A Simple Estimation Algorithm, H.-S. Jacob Tsao, Minnie Patel

Faculty Publications

The number of model parameters of a 2k factorial design grows exponentially. When the number of factors is large, numerous higher-order interactions constitute a vast majority of the model parameters while many of them do not exist or are insignificant. The classic methods of fractional factorial designs, Plackett–Burman designs, Taguchi designs, etc. seek an already developed and often cataloged design that fits exactly the problem being tackled or select a design that fits it the most. Most, if not all, of these designs were developed in absence of convenient computation tools and enjoy computational simplicity. The necessary number of treatment …

Achieving Reliable Generation \& Delivery Of Energy Through Robust Optimization, Anna Danandeh

USF Tampa Graduate Theses and Dissertations

In this dissertation, we elaborate on the inherent risks and uncertainties in power systems and associated industries, and develop practical solution methods to eliminate their adverse effects.

our research agenda consists of practice-driven problems in different stages of power generation as follows. (1) Affordable fuel procurement through developing a comprehensive fuel supply chain design and operations planning system for electricity generation companies, (2) reliable electricity generation through incorporating dynamic asset rating concept in the unit commitment problem, and (3) efficient demand management through proposing a job scheduling model for effective local generation consumption.

Since reliability cannot be compromised in energy …

Enhancing Safety Management System In An Offshore Aviation Company, Nazmus Saqib

Chulalongkorn University Theses and Dissertations (Chula ETD)

The main aim of the research is to enhance the safety management system through the introduction and tracking of safety performance indicator “non-compliance per flight hour”. All the non-compliances related to the main operational departments were gathered from the data base of the case study company for the year 2014. It was found that the non-compliances per flight hour were highest from the Aircraft Maintenance Department with the exact number being 3.30 non-compliances per flight hour. The scope of this research was therefore focused on the Aircraft Maintenance Department. Aircraft maintenance is a large department so the next step in …

Improvement Of Flat Concrete Roof Tile Manufacturing Process, Korkiat Wiratkapan

Chulalongkorn University Theses and Dissertations (Chula ETD)

The objective of this research is to improve the manufacturing process of a concrete roof tile manufacturing company to solve its problems of low labour productivity, rising labour costs and scarcity of labour. Initial analysis established that press forming was a bottleneck in the overall process and used the most manpower. Process activity mapping and Work study were used as tools to analyse the problems to identify non-value-added activities. The seven wastes technique was then applied to define the wastes in the manufacturing process. Improvement alternatives were identified with the aid of the ECRS technique and Lean tools, and these …

Size Effects In Human Visual Inspection For Micro/Meso Scale Parts, Sri Harsha Kavuri

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Visual inspection has been a major method of quality control in conventional manufacturing processes for the last fifty years. Utilizing trained human inspectors to perform this visual inspection has been the most effective means of maintaining quality control. Extensive research has been performed to understand the factors that influence the human inspection process.

In the recent years, there has been a significant emphasis on manufacturing at the smaller end of the size-spectrum such as Micro and Meso scale manufacturing. Quality control at becomes a challenging task due to the extremely small sizes. Several automated visual inspection techniques have been proposed …

Influence Of Spatial Variations Of Railroad Track Stiffness And Material Inclusions On Fatigue Life, Celestin Nkundineza

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Railroad transportation is very important for economic growth and effective maintenance is one critical factor for its economic sustainability. The high repetitive forces from a moving railcar induce cyclic stresses that lead to rail bending and potential deterioration due to fatigue crack initiation and propagation. Previous research for prediction of fatigue life has been done under the assumptions of a uniform track bed and a homogeneous rail. However the spatial variation of the track stiffness is expected to increase the maximum stresses in the rail and, therefore, accelerate the fatigue process. The research described in this dissertation is focused on …

Systems Approach To Producing Electrospun Polyvinylidene Difluoride Fiber Webs With Controlled Fiber Structure And Functionality, Brian D. Bell

USF Tampa Graduate Theses and Dissertations

Polyvinylidene difluoride (PVDF) is a functional polymeric material that can be used for a wide variety of applications. There are many new future applications that were recently suggested for electrospun PVDF fibers. Electrospinning is a process capable of producing nano to micro sized PVDF fibers in a web. It is important to control the structure of the web during electrospinning because by controlling the structure of the web it is possible for the PVDF fiber web to have increased performance in comparison to other common forms of PVDF.

While past scientific literature focused on applications of PVDF fibers, little was …

A Decision Support Simulation Model For Bed Management In Healthcare, Raja A. Baru

Masters Theses

"In order to provide access to care in a timely manner, it is necessary to effectively manage the allocation of limited resources such as beds. Bed management is key to the effective delivery of high-quality and low-cost healthcare. An efficient utilization of beds requires a detailed understanding of the hospital's operational behavior. It is necessary to understand the behavior of a hospital in order to make necessary adjustments to its resources, and policies, which can improve patient's access to care. The aim of this research was to develop a discrete event simulation to assist in planning and staff scheduling decisions. …

Utilizing Learning Style Preferences And Quality Function Deployment For Curriculum Development, Julie M. Ezzell

Masters Theses

"Workplace requirements continually evolve to keep pace with the developing global market. To meet ever increasing standards, educational institutions have been investigating methods to prepare students for their future employment. Course modifications should be carefully considered to meet the requirements of all stakeholders, including those of the students. The objective of this research was to provide students with an overall better learning experience that tailors the teaching methods to his/her individual learning preferences. To meet this objective, a comprehensive survey was provided to an undergraduate course in quality. The survey documented the student's individuality when learning and made note of …

Preliminary Investigation Into The Cause Of Pinhole Porosity In Aluminum Metal Castings From Serpentine Impurities In Olivine Sand, Brodie J. Biersner

Dissertations and Theses @ UNI

The problem addressed in this study is how contaminates in the foundry molding aggregate olivine, affect aluminum castings during the casting process. This research will concentrate on hydrated contaminates, specifically the mineral serpentine. The purpose of this research is to better understand how hydrated minerals contribute to the generation of pinhole porosity defects during the casting process. Understanding how impurities in foundry aggregates affect the casting process would aid in the reduction of scrap caused by core and molding sands, ultimately providing savings to the casting manufacturer.

A foundry grade olivine was compared to a new source of olivine to …

Quantum Inspired Algorithms For Learning And Control Of Stochastic Systems, Karthikeyan Rajagopal

Doctoral Dissertations

"Motivated by the limitations of the current reinforcement learning and optimal control techniques, this dissertation proposes quantum theory inspired algorithms for learning and control of both single-agent and multi-agent stochastic systems.

A common problem encountered in traditional reinforcement learning techniques is the exploration-exploitation trade-off. To address the above issue an action selection procedure inspired by a quantum search algorithm called Grover's iteration is developed. This procedure does not require an explicit design parameter to specify the relative frequency of explorative/exploitative actions.

The second part of this dissertation extends the powerful adaptive critic design methodology to solve finite horizon stochastic optimal …

The Engagement Of Expert Opinions In The Modeling Of Multi-Attribute Decision Making For The Selection Of Project Delivery Methods In Building Construction, Issam H. Algraiw

Doctoral Dissertations

"Choosing the most appropriate project delivery method (PDM) available is acknowledged as a crucial issue in the construction industry. Both the choice and application of an unsuitable PDM can result in project failure. Likewise, the selection of a suitable PDM can increase the chance for project success. A method of selecting from among the seven PDMs recognized by the Construction Specifications Institute (CSI) was created in an attempt to address this issue.

This research was comprised of three objectives. The first objective was to determine the influential factors needed to select the appropriate PDMs available to the US construction industry. …

Computational Intelligence Based Complex Adaptive System-Of-Systems Architecture Evolution Strategy, Siddharth Agarwal

Doctoral Dissertations

The dynamic planning for a system-of-systems (SoS) is a challenging endeavor. Large scale organizations and operations constantly face challenges to incorporate new systems and upgrade existing systems over a period of time under threats, constrained budget and uncertainty. It is therefore necessary for the program managers to be able to look at the future scenarios and critically assess the impact of technology and stakeholder changes. Managers and engineers are always looking for options that signify affordable acquisition selections and lessen the cycle time for early acquisition and new technology addition. This research helps in analyzing sequential decisions in an evolving …

Risk Based Optimization For Improving Emergency Medical Systems, Sandhya Saisubramanian, Pradeep Varakantham, Hoong Chuin Lau

Research Collection School Of Computing and Information Systems

In emergency medical systems, arriving at the incident location a few seconds early can save a human life. Thus, this paper is motivated by the need to reduce the response time – time taken to arrive at the incident location after receiving the emergency call – of Emergency Response Vehicles, ERVs (ex: ambulances, fire rescue vehicles) for as many requests as possible. We expect to achieve this primarily by positioning the "right" number of ERVs at the "right" places and at the "right" times. Given the exponentially large action space (with respect to number of ERVs and their placement) and …

Modeling Supply Chain Interdependent Critical Infrastructure Systems, Varun Ramachandran

Doctoral Dissertations

"While strategies for emergency response to large-scale disasters have been extensively studied, little has been done to map medium- to long-term strategies capable of restoring supply chain infrastructure systems and reconnecting such systems from a local urban area to national supply chain systems. This is, in part, because no comprehensive, data-driven model of supply chain networks exists. Without such models communities cannot re-establish the level of connectivity required for timely restoration of goods and services. This dissertation builds a model of supply chain interdependent critical infrastructure (SCICI) as a complex adaptive systems problem. It defines model elements, data needs/element, the …

A Cell Formation Algorithm For Sequential Processes With Alternative Machine Selection In The Automotive Lighting Industry, Victor Manuel Loya Garnica

Open Access Theses & Dissertations

At the present time, there are more than 12 big companies dedicated to design and produce OEM lighting systems for cars and trucks. The manufacturing processes for headlamps, tail lamps and any other exterior vehicle lighting are very common in the auto industry. Still, every automotive lamp assembly is different from brand to brand and even between the different vehicle models. Indeed, there are car headlamps with less than 30 sub-components and others with up to 300 elements. This implies creating diverse part numbers which share or hold varying manufacturing methods within a specific facility. Management of the plant resources …

Wind Farm Optimization Using Evolutionary Algorithms, Carlos Marco Ituarte-Villarreal

Open Access Theses & Dissertations

In recent years, the wind power industry has focused its efforts on solving the Wind Farm Layout Optimization (WFLO) problem. Wind resource assessment is a pivotal step in optimizing the wind-farm design and siting and, in determining whether a project is economically feasible or not. In the present work, three (3) different optimization methods are proposed for the solution of the WFLO: (i) A modified Viral System Algorithm applied to the optimization of the proper location of the components in a wind-farm to maximize the energy output given a stated wind environment of the site. The optimization problem is formulated …

Single And Multiple Objective Biomass-To-Biofuel Supply Chain Optimization Considering Environmental Impacts, Claudia Evangelina Valles Sosa

Open Access Theses & Dissertations

Bioenergy has become an important alternative source of energy to alleviate the reliance on petroleum energy. Bioenergy offers diminishing climate change by reducing Green House Gas Emissions, as well as providing energy security and enhancing rural development. The Energy Independence and Security Act mandate the use of 21 billion gallons of advanced biofuels including 16 billion gallons of cellulosic biofuels by the year 2022. It is clear that Biomass can make a substantial contribution to supply future energy demand in a sustainable way. However, the supply of sustainable energy is one of the main challenges that mankind will face over …

Safety Culture Monitoring: A Management Approach For Assessing Nuclear Safety Culture Health Performance Utilizing Multiple-Criteria Decision Analysis, James Harold Warren Jr.

Engineering Management & Systems Engineering Theses & Dissertations

Nuclear power plants are among the most technologically complex of all energy facilities. This complexity reflects the precision needed in design, maintenance and operations to harness the energy of the atom safely, reliably and economically. Nuclear energy thus requires consistent, high levels of organizational performance by the highly skilled professionals who operate and maintain nuclear power plants (Nuclear Energy Institute [NEI], 2014, p. 1).

A key element for achieving consistent, high levels of performance in a nuclear organization is its safety culture. Nuclear safety culture is for an organization what character and personality is for an individual: a feature that …

A Framework And System For A Multi-Model Decision Aid For Sustainable Farming Practices, Kasi Bharath Vegesana

Computational Modeling & Simulation Engineering Theses & Dissertations

Decision support systems (DSS) for farmers address the need for modeling multiple processes and scenarios that affect farmer decision making. Existing DSS have various drawbacks that stop them from being deployed as decision support tools. This research proposes a multi-model simulation framework that can be used to analyze farm management practices at the crop level, individual farm level and at the community level to show the impact and alternatives for smallholder farming practices. A generic crop growth model is proposed, based on existing equations. We run sensitivity analysis on the model to identify important variables. The outputs from the crop …