Engineering Commons^™

Modelling And Analysis Of Dynamic Capacity Complexity In Multi-Stage Production, Ahmed M. Deif, Hoda A. Elmaraghy

Industrial Technology and Packaging

The uncertainty associated with managing dynamic capacity problem is the main source of its complexity. This article presents a system dynamics approach to model and analyse operational complexity of dynamic capacity in multi-stage production. The unique feature of this approach is that it captures the stochastic nature of three main sources of complexity associated with dynamic capacity. These are the demand, internal manufacturing delay and capacity scalability delay. The developed model was demonstrated by an industrial case study of multi-stage printed circuit board assembly line. The analysis of simulation experiments showed that ignoring complexity sources can lead to wrong decisions …

Use Of Oids And Iis In En13606, Damon Berry, Jostein Ven, Gerard Freriks, David Moner

Reports

No abstract provided.

Geometric And Electronic Structure Of Graphene Bilayer Edges, Ji Feng, Liang Qi, Jian Yu Huang, Ju Li

Departmental Papers (MSE)

We present a computational investigation of free-standing graphene bilayer edge (BLE) structures, aka “fractional nanotubes.” We demonstrate that these curved carbon nanostructures possess a number of interesting properties, electronic in origin. The BLEs, quite atypical of elemental carbon, have large permanent electric dipoles of 0.87 and 1.14 debye/Å for zigzag and armchair inclinations, respectively. An unusual, weak AA interlayer coupling leads to a twinned double-cone dispersion of the electronic states near the Dirac points. This entails a type of quantum Hall behavior markedly different from what has been observed in graphenebased materials, characterized by a magnetic field-dependent resonance in the …

Reliability Estimation Of Complex Numerical Problems Using Modified Conditional Expectation Method, Christopher D. Eamon, Bulakorn Charumas

Civil and Environmental Engineering Faculty Research Publications

A simulation-based structural reliability analysis method is presented. It is intended as an alternate approach to estimate reliability for problems for which most-probable point of failure methods fail and when computational resources are limited. The proposed method combines conditional expectation and estimating the PDF or CDF of a selected portion of the limit state. In the proposed approach, complex limit state functions are simplified to two random variable problems. The success of the simplification depends on the quality of the CDF estimate. Results indicate that the method may provide accurate and efficient solutions for some difficult reliability problems.

Application Of An Inverse-Hysteresis Iterative Control Algorithm For Afm Fabrication, Seth Ashley

Theses and Dissertations

An iterative control algorithm (ICA) which uses an approximate inverse-hysteresis model is implemented to compensate for hysteresis to precisely fabricate features on a soft polymer substrate using an atomic force microscope (AFM). The AFM is an important instrument in micro/nanotechnology because of its ability to interrogate, manipulate, and fabricate objects at the micro/nanoscale. The AFM uses a piezoelectric actuator to position an AFM-probe tip relative to the sample surface in three dimensions. In particular, precision lateral control of the AFM-probe tip relative to the sample surface is needed to ensure high-performance operation of the AFM. However, precision lateral positioning of …

Effects Of Thermal Gradient And Fines Content On Frost Heave Of An Alaska Base Material, Adam Ray Homewood

Theses and Dissertations

The objective of this research was to investigate the effects of thermal gradient and fines content and the interaction between these two factors on the frost heave characteristics of a typical Alaska base material. The laboratory frost heave testing involved one type of aggregate base material, three thermal gradients, and three fines contents in a full-factorial experimental design with two replicates. The aggregate was classified in the American Association of State Highway and Transportation Officials soil classification system as A-1-a; the thermal gradients were 0.15, 0.30, and 0.45 ºC/cm; and the fines contents were 6, 8, and 10 percent. After …

Discovering Gene Functional Relationships Using Faun (Feature Annotation Using Nonnegative Matrix Factorization), Elina Tjioe, Michael W. Berry, Ramin Homayouni

Faculty Publications and Other Works -- EECS

Background

Searching the enormous amount of information available in biomedical literature to extract novel functional relationships among genes remains a challenge in the field of bioinformatics. While numerous (software) tools have been developed to extract and identify gene relationships from biological databases, few effectively deal with extracting new (or implied) gene relationships, a process which is useful in interpretation of discovery-oriented genome-wide experiments.

Results

In this study, we develop a Web-based bioinformatics software environment called FAUN or Feature Annotation Using Nonnegative matrix factorization (NMF) to facilitate both the discovery and classification of functional relationships among genes. Both the computational complexity …

Cybersecurity: Growing Like Topsy!, Ibpp Editor

International Bulletin of Political Psychology

This article discusses cybersecurity in an intelligence context – what it is, what it does to us, and the sudden (and somewhat unplanned) increase in financial support for the area.

Quantum Imaging And Inverse Scattering, John C. Schotland

Departmental Papers (BE)

We consider the inverse scattering problem that arises in two-photon quantum imaging with interferometric measurements. We show that the two-point correlation function of the field contains information about the scattering medium at a spatial frequency of twice the Rayleigh bandwidth. The linearized inverse problem, however, yields reconstructions with a resolution of λ=2, where λ is the wavelength of light.

Diseño, Construcción Y Calibración De Un Modelo Físico Para El Estudio De Pérdidas De Energía, Diego Alejandro Fernández Bolaños, Benjamín Perez Cristancho

Ingeniería Civil

No abstract provided.

The Impact Of Multiple Computing And Digital Arts Degrees On Undergraduate Recruitment, Amber Settle, Liz Friedman, Mary Jo Davidson

Amber Settle

Do Surfaces With Mixed Hydrophilic And Hydrophobic Areas Enhance Pool Boiling?, Amy Rachel Betz, Jie Xu, Huihe Qiu, Daniel Attinger

Daniel Attinger

We demonstrate that smooth and flat surfaces combining hydrophilic and hydrophobicpatterns improve pool boiling performance. Compared to a hydrophilicsurface with 7° wetting angle, the measured critical heat flux and heat transfer coefficients of the enhanced surfaces are, up to respectively, 65% and 100% higher. Different networks combining hydrophilic and hydrophobic regions are characterized. While all tested networks enhance the heat transfer coefficient, large enhancements of critical heat flux are typically found for hydrophilic networks featuring hydrophobic islands. Hydrophilic networks indeed are shown to prevent the formation of an insulating vapor layer.

Auxiliary State Variables For Rotor Crack Detection, Zbigniew Kulesza, Jerzy T. Sawicki

Mechanical Engineering Faculty Publications

In the present study, a new model-based method for rotor crack detection and crack location is proposed. The finiteelement model of the rotor-bearing system accounts for the breathing mechanism of the crack. The model of the rotor system is augmented with an auxiliary single-degree-of-freedom oscillator. The observer is designed and the estimates of its two auxiliary state variables are proposed as crack indicators. The crack location along the shaft is determined by designing a set of observers, which calculate the values of these indicators for different possible crack locations along the shaft. The proposed method is validated numerically and the …

A Review Of Zero Discharge Wastewater Treatment Systems Using Reed Willow Bed Combinations In Ireland, Sean O'Hogain, Liam Mccarton, Anna Reid, John Turner

Conference papers

The concept of a reed willow bed combination has the potential to achieve a zero discharge wastewater treatment system. This paper will present results from a two year study to monitor the performance of a reed willow bed facility at Lynches Lane, Co. Dublin, Ireland. Outline design specifications for the facility will be presented. Monitoring results for a two year period including influent and effluent parameters, rainfall, potential evapotranspiration, and soil classification will be presented and discussed. During the two year monitoring period the system achieved a zero discharge. This paper will discuss the potential widespread application of similar systems …

Absolute Blood Velocity Measured With A Modified Fundus Camera, Donald D. Duncan, Paul Lemaillet, Mohamed Ibrahim, Quan D. Nguyen, Matthias Hiller, Jessica C. Ramella-Roman

Electrical and Computer Engineering Faculty Publications and Presentations

We present a new method for the quantitative estimation of blood flow velocity, based on the use of the Radon transform. The specific application is for measurement of blood flow velocity in the retina. Our modified fundus camera uses illumination from a green LED and captures imagery with a high-speed CCD camera. The basic theory is presented, and typical results are shown for an in vitro flow model using blood in a capillary tube. Subsequently, representative results are shown for representative fundus imagery. This approach provides absolute velocity and flow direction along the vessel centerline or any lateral displacement therefrom. …

Perpetual Exploration Of Relational Information And Enhanced Star Glyphs For Multi-Source Data Visualization, Andrew Crowell

Theses and Dissertations

Information Visualization is an area of research concerned with the presentation of abstract data in a visual format. It has many diverse applications in fields of software engineering, information sciences, biology, chemistry, and medical, among others. This thesis is primarily concerned with the application of information visualization to the display of directed graphs and to the display of multivariate data for analysis. Two novel applications will be presented that are both advancements in the field of information visualization. The first application applies to the visualization and navigation of large or infinite graphs and networks. The quality of a graph drawing …

Fpga-Based Fuzzy Inference System For Real-Time Embedded Applications, Philadelphia University

Philadelphia University, Jordan

No abstract provided.

Handling External Events Efficiently In Gillespie's Stochastic Simulation Algorithm, Brad Geltz

Theses and Dissertations

Gillespie's Stochastic Simulation Algorithm (SSA) provides an elegant simulation approach for simulating models composed of coupled chemical reactions. Although this approach can be used to describe a wide variety biological, chemical, and ecological systems, often systems have external behaviors that are difficult or impossible to characterize using chemical reactions alone. This work extends the applicability of the SSA by adding mechanisms for the inclusion of external events and external triggers. We define events as changes that occur in the system at a specified time while triggers are defined as changes that occur to the system when a particular condition is …

Accident In Bhopal: Observations 20 Years Later, Ronald J. Willey, Dennis C. Hendershot, Scott Berger

Ronald J. Willey

The most influential process safety accident passed its 20th anniversary on Dec 3, 2004. At an international symposium to mark the event in Kanpur, India during the week of this anniversary, process safety practitioners from around the world assembled to discuss progress in resolving the Bhopal tragedy and in advancing the practice of process safety worldwide. This paper reports the main conclusions from the conference, and provides insight into the Bhopal site as attendees found it in December 2004. Since 1984, many positive steps worldwide have been made in regards to improvements in process safety and protection of personnel within …

The Virtual Hip: An Anatomically Accurate Finite Element Model Based On The Visible Human Dataset, Jonathan M. Ford

USF Tampa Graduate Theses and Dissertations

The purpose of this study is to determine if element decimation of a 3-D anatomical model affects the results of Finite Element Analysis (FEA). FEA has been increasingly applied to the biological and medical sciences. In order for an anatomical model to successfully run in FEA, the 3-D model’s complex geometry must be simplified, resulting in a loss of anatomical detail. The process of decimation reduces the number of elements within the structure and creates a simpler approximation of the model. Using the National Library of Medicine’s Visible Human Male dataset, a virtual 3-D representation of several structures of the …