Engineering Commons^™

Evaluating Safety And Productivity Relationship In Human-Robot Collaboration, Aayush Jain, Shakra Mehak, Philip Long, John D. Kelleher, Michael Guilfoyle, Maria Chiara Leva

Conference papers

Collaborative robots can improve ergonomics on factory floors while allowing a higher level of flexibility in production. The evolution of robotics and cyber-physical systems in size and functionality has enabled new applications which were never foreseen in traditional industrial robots. However, the current human-robot collaboration (HRC) technologies are limited in reliability and safety, which are vital in risk-critical scenarios. Certainly, confusion about European safety regulations has led to situations where collaborative robots operate behind security barriers, thus negating their advantages while reducing overall application productivity. Despite recent advances, developing a safe collaborative robotic system for performing complex industrial or daily …

Efficiently Estimating Survival Signature And Two-Terminal Reliability Of Heterogeneous Networks Through Multi-Objective Optimization, Daniel Bruno Lopes Da Silva

Graduate Theses and Dissertations

The two-terminal reliability problem is a classical reliability problem with applications in wired and wireless communication networks, electronic circuit design, computer networks, and electrical power distribution, among other systems. However, the two-terminal reliability problem is among the hardest combinatorial problems and is intractable for large, complex networks. Several exact methods to solve the two-terminal reliability problem have been proposed since the 1960s, but they have exponential time complexity in general. Hence, practical studies involving large network-type systems resort to approximation methods to estimate the system's reliability. One attractive approach for quantifying the reliability of complex systems is to use signatures, …

Study On New Sampling Plans And Optimal Integration With Proactive Maintenance In Production Systems, Sinan Obaidat

Graduate Theses and Dissertations

Sampling plans are statistical process control (SPC) tools used mainly in production processes. They are employed to control processes by monitoring the quality of produced products and alerting for necessary adjustments or maintenance. Sampling is used when an undesirable change (shift) in a process is unobservable and needs time to discover. Basically, the shift occurs when an assignable cause affects the process. Wrong setups, defective raw materials, degraded components are examples of assignable causes. The assignable cause causes a variable (or attribute) quality characteristic to shift from the desired state to an undesired state.

The main concern of sampling is …

Reliability Estimation Of Reciprocating Seals Based On Multivariate Dependence Analysis And It's Experimental Validation, Chao Zhang, Rentong Chen, Shaoping Wang, Yujie Qian, Mileta M. Tomovic

Engineering Technology Faculty Publications

Accurate reliability estimation for reciprocating seals is of great significance due to their wide use in numerous engineering applications. This work proposes a reliability estimation method for reciprocating seals based on multivariate dependence analysis of different performance indicators. Degradation behavior corresponding to each performance indicator is first described by the Wiener process. Dependence among different performance indicators is then captured using D-vine copula, and a weight-based copula selection method is utilized to determine the optimal bivariate copula for each dependence relationship. A two-stage Bayesian method is used to estimate the parameters in the proposed model. Finally, a reciprocating seal degradation …

Developing Leading And Lagging Indicators To Enhance Equipment Reliability In A Lean System, Dhanush Agara Mallesh

Masters Theses

With increasing complexity in equipment, the failure rates are becoming a critical metric due to the unplanned maintenance in a production environment. Unplanned maintenance in manufacturing process is created issues with downtimes and decreasing the reliability of equipment. Failures in equipment have resulted in the loss of revenue to organizations encouraging maintenance practitioners to analyze ways to change unplanned to planned maintenance. Efficient failure prediction models are being developed to learn about the failures in advance. With this information, failures predicted can reduce the downtimes in the system and improve the throughput.

The goal of this thesis is to predict …

Probabilistic Analysis Of Wear Of Polymer Material Used In Medical Implants, V. Perel, Tarun Goswami

Biomedical, Industrial & Human Factors Engineering Faculty Publications

Probabilistic methods are applied to the study of fatigue wear of sliding surfaces. A variance of time to failure (to occurrence of maximum allowable wear depth) is evaluated as a function of a mean wear rate of normal wear and a size of wear particles. A method of estimating probability of failure-free work during a certain time interval (reliability) is presented. An effect of the bedding-in phase of wear on the reliability is taken into account. Experimental data for Ultra High Molecular Weight Polyethylene (UHMWPE) cups of artificial hip implants is used to make numerical calculations.

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 …

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 …

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 …

Reliability Analysis Of Nanocrystal Embedded High-K Nonvolatile Memories, Chia-Han Yang

Doctoral Dissertations

The evolution of the MOSFET technology has been driven by the aggressive shrinkage of the device size to improve the device performance and to increase the circuit density. Currently, many research demonstrated that the continuous polycrystalline silicon film in the floating-gate dielectric could be replaced with nanocrystal (nc) embedded high-k thin film to minimize the charge loss due to the defective thin tunnel dielectric layer.

This research deals with both the statistical aspect of reliability and electrical aspect of reliability characterization as well. In this study, the Zr-doped HfO₂ (ZrHfO) high-k MOS capacitors, which separately contain the nanocrystalline zinc …

Birnbaum Importance Patterns And Their Applications In The Component Assignment Problem, Qingzhu Yao

Doctoral Dissertations

The Birnbaum importance (BI) is a well-known measure that evaluates the relative contribution of components to system reliability. It has been successfully applied to tackling some reliability problems. This dissertation investigates two topics related to the BI in the reliability field: the patterns of component BIs and the BI-based heuristics and meta-heuristics for solving the component assignment problem (CAP).

There exist certain patterns of component BIs (i.e., the relative order of the BI values to the individual components) for linear consecutive-k-out-of-n (Lin/Con/k/n) systems when all components have the same reliability p. This study summarizes …

A Call Center Simulation Study: Comparing The Reliability Of Cross-Trained Agents To Specialized Agents, Louis Franklin Ali Iii

Masters Theses

Call centers are an important function of most companies’ day to day business activities. They are often the link between a company and its customers and hugely impact the customer’s perspective or point of view (POV) of a company. A call center in the most general sense is a place, representing a business, which receives inbound calls from customers and/or makes outbound calls to customers, the latter being most commonly referred to as telemarketing. There was a time when a typical call center strictly consisted of agents who handled inbound/outbound calls; these agents are considered specialized agents. Generally speaking, a …

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 …

The Optimization Of The Threshold For The Preventive Maintenance Actions In A Condition-Based Maintenance Program Via Dynamic Programming Approach, Kamran Shahanaghi, Mehdi Jafarian, Majid Beikverdi, Zeinab Nezhadbiglari

Mehdi Jafarian

The last step of a condition based maintenance (CBM) program is maintenance decision-making. This step is the most important and the most critical stage of maintenance for executive personnel and management whom work on taking maintenance actions. This decision making would be done according to certain criteria such as risk, cost, reliability and availability. This paper considered a dynamic programming model to optimization of the threshold for the preventive maintenance actions in a condition-based maintenance program. The basis of this modeling is the average cost of maintenance actions, failures and exchanges. In this paper, we improved the memory of the …

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 …

The Optimization Of The Threshold For The Preventive Maintenance Actions In A Condition-Based Maintenance Program Via Dynamic Programming Approach, Mehdi Jafarian, Majid Beikverdi, Kamran Shahanaghi, Zeinab Nezhadbiglari

Mehdi Jafarian

The last step of a condition based maintenance (CBM) program is maintenance decision-making. This step is the most important and the most critical stage of maintenance for executive personnel and management whom work on taking maintenance actions. This decision making would be done according to certain criteria such as risk, cost, reliability and availability. This paper considered a dynamic programming model to optimization of the threshold for the preventive maintenance actions in a condition-based maintenance program. The basis of this modeling is the average cost of maintenance actions, failures and exchanges. In this paper, we improved the memory of the …

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 …

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 …