Operations Research, Systems Engineering and Industrial Engineering Commons^™

Use Of Response Surfaces In The Design Of A Simple Step Stress Accelerated Test Plan, Alexander H. Wong

Graduate Theses and Dissertations

In designing accelerated testing plans, cost is a factor that is missing in much of the literature. This paper explicits considers cost by developing an optimization model with the objective to minimize costs for a simple step stress accelerated test plan. Two methodologies are employed. One is an optimization approach in which an attempt is made to quantify the behavior of a series-parallel hardware system over all stages of testing using a response surface, and then an optimization model is used to determine the settings for stresses and failure mode modifications for all stages of testing prior to the start …

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 …

Reliable Design And Operations Of Infrastructure Systems, Yu An

USF Tampa Graduate Theses and Dissertations

The reliability issue of the infrastructure systems has become one of the major concerns of the system operators. This dissertation is a collection of four published and working papers that address the specific reliable design and operations problems from three different application settings: transportation/telecommunications network, distribution network, and power plant. In these four projects, key random factors like site disruption and uncertain demand are explicitly considered and proper research tools including stochastic programming, robust optimization, and variants of robust optimization are applied to formulate the problems based on which the important and challenging modelling elements (nonlinear congestion, disruption caused demand …

Modeling Preventive Maintenance In Complex Systems, Jessica Rivas

Open Access Theses

This thesis presents an explicit consideration of the impacts of modeling decisions on the resulting maintenance planning. Incomplete data is common in maintenance planning, but is rarely considered explicitly. Robust optimization aims to minimize the impact of uncertainty--here, in contrast, I show how its impact can be explicitly quantified. Doing so allows decision makers to determine whether it is worthwhile to invest in reducing uncertainty about the system or the effect of maintenance. The thesis consists of two parts. Part I uses a case study to show how incomplete data arises and how the data can be used to derive …

Utilizing Atcs Data To Inform A Dynamic Reassignment System For Muni Metro Light Rail Vehicles Departing Embarcadero Station, April M. Hickey

Master's Theses

This is a report of a professional project intended to act as an informational tool for the evaluation of a dynamic dispatch system at Embarcadero Station for the San Francisco Municipal Transportation Agency (SFMTA). Systems that operate dispatch algorithms do so in response to on-time performance and reliability. The optimization problem is documented in many transportation contexts including airline networks, bus dispatch, and freight routing. According to the research, optimizing available options and re-routing based on available options can create a more efficient system that would minimize operating costs and improving service reliability for customers.

The methodology presented here uses …

Reliability Analysis Of Low-Silver Bga Spheres Comparing Failure Detection Criteria, Briana Fredericks

Industrial and Manufacturing Engineering

One of the challenges of solder joint reliability tests is estimating the time of failure of the solder joint. Failure criteria should be able to detect solder joint failure as early as possible, while minimizing the probability of false detection. The failure mechanism under study is cracks due to thermal fatigue. The most common method to estimate failure due to cracks is to monitor the resistance during testing, because solder imaging and cross-sectioning methods are destructive. Current industry failure criteria do not adequately demonstrate the relationship between the size of the crack and the resulting change in resistance. This project …

A Comparison Of American And Asian Automakers' Vehicles In Quality, Reliability, And Safety, Ozge Senoz

Doctoral Dissertations

"Consumer Reports (CR) and J.D. Power and Associates (JDP) are two widely-known agencies that gather data on automobile quality and prepare reports on the data gathered that are related to various aspects of automobiles for different models for each manufacturer. This research has two overarching goals: The first is to determine if there are any clear differences in reliability, between the Japanese and U.S. auto-makers. The second is to determine if there is consistency between JDP and CR in the reliability ratings of vehicles. In order to attain these goals, this dissertation starts with the evaluation of these two major …

Information Quality On The World Wide Web: A User Perspective, Jaikrit Kandari

Department of Industrial and Management Systems Engineering: Dissertations, Theses, and Student Research

Information Quality has emerged as an important measure for the success of Information Systems. At the same time the World Wide Web has established itself as the key infrastructure for information administration, exchange, and publication. Users are getting information from the web at the click of a button however they must filter sub-standard information before they can use quality content. Researchers have aimed to address this problem by suggesting various information quality frameworks. Research till date has seen twenty important Information Quality (IQ) frameworks emerge. These models though varied in their approach and application share a number of characteristics regarding …

Determining A Reliability Factor For Photovoltaic's In San Luis Obispo, Ryan S. Roach

Industrial and Manufacturing Engineering

This project will analyze raw photovoltaic (PV) solar panel performance data in order to determine a reliability factor for solar panels in San Luis Obispo. This project is a subset of a larger project being performed by SLO RESCO, which is funded by a grant from the California Energy Commission. Their project will explore the use of solar, wind, geothermal, and biomass renewable resources. The scope of this project is limited to a small section of RESCO's analysis of solar panel technology and implementation in which a reliability factor will be generated.

The objective is to determine a reliability factor …

Theoretical Exploratory Investigation On Reliability Of Advanced Ceramics By Discrete Element Simulation, Ana Laura Quezada Lara

Open Access Theses & Dissertations

The increasing application of silicon nitride in biomedical and other engineering fields has elevated the necessity to understand its reliability. Due to the complexity of producing pure material researchers have been analyzing the behavior of the material with flaws. In this thesis several scenarios are simulated with the support of PFC2D to analyze microcrack propagation depending on the position, quantity and size of the voids to understand the effect each of the cases have on the material. A four point bending test was applied to each case twice recording the loading force. Having two runs allows doing a statistical analysis …

The Effect Of Ultrasonic Frequency On Gold Wire Bondability And Reliability, Jianbiao Pan, Minh-Nhat Le, Cuong Van Pham

Industrial and Manufacturing Engineering

This paper presents a systematic study on the effect of 120 KHz ultrasonic frequency on the bondability and reliability of fine pitch gold wire bonding to pads over an organic substrate with gold metallizations. The study was carried out on a thermosonic ball bonder that is allowed to easily switch between ultrasonic frequencies of 60 KHz and 120 KHz by changing the ultrasonic transducer and the ultrasonic generator. Bonding parameters were optimized through the design of experimental methodology for four different cases: 25.4 mm wire at 60 kHz, 25.4 mm wire at 120 kHz, 17.8 mm wire at 60 kHz, …

Drop Impact Dynamic Response Study Of Jedec Jesd22-B111 Test Board, Michael Krist, Jianbiao Pan, Andrew Farris, Nicolas Vickers

Industrial and Manufacturing Engineering

Mobile and handheld electronic devices are prone to being dropped. This drop event may result in failure of solder joints inside these devices. The need for RoHS compliant boards coupled with the demand for reliable electronics has resulted in the development of the JEDEC Standard JESD22-B111 to standardize the method of drop testing surface mount electronic components. However, there has been little study on the effects of additional mass on the board and rigidity of the board on drop test reliability. This paper examines the drop impact dynamic responses of the JEDEC JESD22-B111 board. Of interest are the effects of …

The Effect Of Ultrasonic Frequency On Gold Wire Bondability And Reliability, Jianbiao Pan, Minh-Nhat Le, Cuong Van Pham

Industrial and Manufacturing Engineering

This paper presents a systematic study on the effect of 120KHz ultrasonic frequency on the bondability and reliability of fine pitch gold wire bonding. The study was carried out on a thermosonic ball bonder that is allowed to easily switch between ultrasonic frequency of 60KHz and 120 KHz by changing the ultrasonic transducer and the ultrasonic generator. Bonding parameters were optimized through design of experiment methodology for four different cases: 25.4 μm wire at 60 kHz, 25.4 μm wire at 120 kHz, 17.8 μm wire at 60 kHz, and 17.8 μm wire at 120 kHz. The integrity of wire bonds …

Discovering Software Reliability Patterns Based On Multiple Software Projects, Yi Liu, Gerald Adkins, Jeng-Foung Yao, Gita Williams

Journal of International Technology and Information Management

Discovering patterns that indicate software reliability provides valuable information to software project managers. Software Quality Classification (SQC) modeling is a methodology that can be used to discover reliability patterns of large software projects. However, the patterns found by SQC modeling may not be accurate and robust owing to insufficient information used in the training process. This study compares two genetic programming-based SQC models using different volumes of data. These data were extracted from seven different NASA software projects. The results demonstrate that combining data from different projects can produce more accurate and reliable patterns.

Lead-Free Solder Joint Reliability – State Of The Art And Perspectives, Jianbiao Pan, Jyhwen Wang, David M. Shaddock

Industrial and Manufacturing Engineering

There is an increasing demand for replacing tin-lead (Sn/Pb) solders with lead-free solders in the electronics industry due to health and environmental concerns. The European Union recently passed a law to ban the use of lead in electronic products. The ban will go into effect in July of 2006. The Japanese electronics industry has worked to eliminate lead from consumer electronic products for several years. Although currently there are no specific regulations banning lead in electronics devices in the United States, many companies and consortiums are working on lead-free solder initiatives including Intel, Motorola, Agilent Technologies, General Electric, Boeing, NEMI …

Lead-Free Solder Joint Reliability – State Of The Art And Perspectives, Jianbiao Pan, Jyhwen Wang, David M. Shaddock

Industrial and Manufacturing Engineering

There is an increasing demand in replacing tin-lead (Sn/Pb) solders with lead-free solders in the electronics industry due to health and environmental concern. The European Union recently passed a law to ban the use of lead in electronic products. The ban will go into effect in July of 2006. The Japanese electronics industry has worked to eliminate lead from consumer electronic products for several years. Although currently there are no specific regulations banning lead in electronics devices in the United States, many companies and consortiums are working on lead-free solder initiatives including Intel, Motorola, Agilent Technologies, General Electric, Boeing, NEMI …

Using Bayesian Statistics In Operational Testing, Thuan H. Tran

Theses and Dissertations

This research explored the applicability of Bayesian methods to the problem of determining the reliability of a series system, a parallel system, and a bridge system. The time to failure of each component in each system is assumed to be exponentially distributed. A basic exponential case and a basic binomial case are also evaluated. In general, using simulated data and real data when possible, the Bayesian methods produced confidence intervals that were much tighter than the classical inference methods, thus allowing a decision maker to have higher confidence in making a decision. System level data and aggregated component level data …

Estimation Of The Captive-Carry Survival Function For The Advanced Medium Range Air-To-Air Missile (Amraam), David R. Denhard

Theses and Dissertations

This thesis considers the problem of estimating the survival function of an item (probability that the item functions for a time greater than a given time t) from sampling data subject to partial right censoring (a portion of the items in the sampling data have not yet been observed to fail). Specifically the thesis describes several parametric and non-parametric statistical models that can be used when the sampling data is subject to partial right censoring. These models are applied to the case of estimating the captive-carry survival function of the AIM-120A Advanced Medium Range Air-to-Air Missile (AMRAAM).

Reliability Trend Analyses With Statistical Confidence Limits Using The Luke Reliability Trend Chart, Stephen R. Luke

Engineering Management & Systems Engineering Theses & Dissertations

In electronic systems, it is interesting to understand exactly how the reliability is changing with time. Dynamic performance changes when a system passes from infant mortality stage into useful life phase and when the system passes from useful life phase into wearout phase. Dynamic performance also changes when the system is redesigned or when the system is acted on by a number of other outside forces such as a change in maintenance policy, escalation of alignment problems, or a change in training program. It is important to know when a system is changing dynamically in order to assess design, policy …

Software Quality Assurance, Edward C. Soistman

Retrospective Theses and Dissertations

The problems associated with software development and use are investigated from a management point of view. Having identified the critical aspects of effective software management, an approach is suggested for the creation and implementation of a software quality assurance program, Particular attention is focused on the concept of Life Cycle Procurement as currently utilized by the Department of Defense. The research was accomplished in two phases. The first consisted of an extensive literature search, seminar attendance and participation in several working groups assigned the responsibility for establishing software quality assurance guidelines. The second phase involved direct participation in the development …