Engineering Commons^™

Investigation Of Generalized Dsss Under Multiple Access And Multipath, Indrasena Varakantham

ETD Archive

In this thesis we investigate and compare the average performances of ordinary and generalized direct sequence spread spectrum (DSSS) systems under multi-path fading and multiple-access interference. As part of multiple access performance, we also consider generation of orthogonal and semi-orthogonal codes using various algorithms, and compare cross correlation properties of codes formed by 2-level and 3-level signature sequences. In order to simulate ordinary and generalized DSSS performance under various scenarios, we develop a complete Java library with classes that are well encapsulated with regard to communication modules and loosely coupled so that we can reuse them to create any type …

Effect Of Rib Turbulators On Heat Transfer Performance In Stationary Ribbed Channels, Aravind Rohan Sampath

ETD Archive

The thermal performance was examined computationally for the stationary channels with rib turbulators oriented at 90 degrees. Ribs were placed on opposite walls and the heat transfer coefficients and frictional loss were calculated. Three stationary channels with aspect ratios (W/H) 1, 2 and 4 were considered for the analysis. The thermal performance was measured by calculating the Nusselt number and frictional losses. Square ribs (w/e = 1) were considered as the baseline configuration. The rib width and rib spacing varies while the rib height is maintained constant. Rib spacing (P/e) of 10 and 20 and rib width to rib height …

Dynamic Analysis Of A Rotor Bearing System, Sandi Elhibir

ETD Archive

This thesis presents the results of the finite element analysis (FEA) approach for designing a Permanent Magnet Alternator (PMA). The PMA is configured as a cantilever hollow shaft supported by two identical rolling contact bearings. The performance requirements of the PMA are a maximum operating speed of 16,000 rpm, with a maximum shaft displacement of less than 0.010 in at its free end. The static and dynamic results of a cantilever beam was predicted by closed form solutions and verified to those results obtained from FEA for code validation. A mathematical model of a rotor-bearing system was proposed and analyzed …

Reusable, Interactive, Multilingual Online Avatars, Charlie Cullen, Carl Goodman, Paula Mcgloin, Anna Deegan

Conference papers

This paper details a system for delivering reusable, interactive multilingual avatars in online children’s games. The development of these avatars is based on the concept of an intelligent media object that can be repurposed across different productions. The system is both language and character independent, allowing content to be reused in a variety of contexts and locales. In the current implementation, the user is provided with an interactive animated robot character that can be dressed with a range of body parts chosen by the user in real-time. The robot character reacts to each selection of a new part in a …

A Hierarchical Method Based On Active Shape Models And Directed Hough Transform For Segmentation Of Noisy Biomedical Images; Application In Segmentation Of Pelvic X-Ray Images, Rebecca Smith, Kayvan Najarian, Kevin R. Ward

Computer Science Publications

Background

Traumatic pelvic injuries are often associated with severe, life-threatening hemorrhage, and immediate medical treatment is therefore vital. However, patient prognosis depends heavily on the type, location and severity of the bone fracture, and the complexity of the pelvic structure presents diagnostic challenges. Automated fracture detection from initial patient X-ray images can assist physicians in rapid diagnosis and treatment, and a first and crucial step of such a method is to segment key bone structures within the pelvis; these structures can then be analyzed for specific fracture characteristics. Active Shape Model has been applied for this task in other bone …

Unified Wavelet And Gaussian Filtering For Segmentation Of Ct Images; Application In Segmentation Of Bone In Pelvic Ct Images, Simina Vasilache, Kevin R. Ward, Charles Cockrell, Jonathan Ha, Kayvan Najarian

Computer Science Publications

Background

The analysis of pelvic CT scans is a crucial step for detecting and assessing the severity of Traumatic Pelvic Injuries. Automating the processing of pelvic CT scans could impact decision accuracy, decrease the time for decision making, and reduce health care cost. This paper discusses a method to automate the segmentation of bone from pelvic CT images. Accurate segmentation of bone is very important for developing an automated assisted-decision support system for Traumatic Pelvic Injury diagnosis and treatment.

Methods

The automated method for pelvic CT bone segmentation is a hierarchical approach that combines filtering and histogram equalization, for image …

A Comparative Analysis Of Multi-Level Computer-Assisted Decision Making Systems For Traumatic Injuries, Soo-Yeon Ji, Rebecca Smith, Toan Huynh, Kayvan Najarian

Computer Science Publications

Background

This paper focuses on the creation of a predictive computer-assisted decision making system for traumatic injury using machine learning algorithms. Trauma experts must make several difficult decisions based on a large number of patient attributes, usually in a short period of time. The aim is to compare the existing machine learning methods available for medical informatics, and develop reliable, rule-based computer-assisted decision-making systems that provide recommendations for the course of treatment for new patients, based on previously seen cases in trauma databases. Datasets of traumatic brain injury (TBI) patients are used to train and test the decision making algorithm. …

Brain Mapping And Detection Of Functional Patterns In Fmri Using Wavelet Transform; Application In Detection Of Dyslexia, Soo-Yeon Ji, Kevin R. Ward, Kayvan Najarian

Computer Science Publications

Background

Functional Magnetic Resonance Imaging (fMRI) has been proven to be useful for studying brain functions. However, due to the existence of noise and distortion, mapping between the fMRI signal and the actual neural activity is difficult. Because of the difficulty, differential pattern analysis of fMRI brain images for healthy and diseased cases is regarded as an important research topic. From fMRI scans, increased blood ows can be identified as activated brain regions. Also, based on the multi-sliced images of the volume data, fMRI provides the functional information for detecting and analyzing different parts of the brain.

Methods

In this …

Automated Ventricular Systems Segmentation In Brain Ct Images By Combining Low-Level Segmentation And High-Level Template Matching, Wenan Chen, Rebecca Smith, Soo-Yeon Ji, Kevin R. Ward, Kayvan Najarian

Computer Science Publications

Background

Accurate analysis of CT brain scans is vital for diagnosis and treatment of Traumatic Brain Injuries (TBI). Automatic processing of these CT brain scans could speed up the decision making process, lower the cost of healthcare, and reduce the chance of human error. In this paper, we focus on automatic processing of CT brain images to segment and identify the ventricular systems. The segmentation of ventricles provides quantitative measures on the changes of ventricles in the brain that form vital diagnosis information.

Methods

First all CT slices are aligned by detecting the ideal midlines in all images. The initial …

Whole-Genome Resequencing Of Escherichia Coli K-12 Mg1655 Undergoing Short-Term Laboratory Evolution In Lactate Minimal Media Reveals Flexible Selection Of Adaptive Mutations, Tom M. Conrad, Andrew R. Royce, M. Kenyon Applebee, Christian L. Barrett, Bin Xie, Yuan Gao, Bernhard Ø. Palsson

Computer Science Publications

Background

Short-term laboratory evolution of bacteria followed by genomic sequencing provides insight into the mechanism of adaptive evolution, such as the number of mutations needed for adaptation, genotype-phenotype relationships, and the reproducibility of adaptive outcomes.

Results

In the present study, we describe the genome sequencing of 11 endpoints of Escherichia coli that underwent 60-day laboratory adaptive evolution under growth rate selection pressure in lactate minimal media. Two to eight mutations were identified per endpoint. Generally, each endpoint acquired mutations to different genes. The most notable exception was an 82 base-pair deletion in the rph-pyrE operon that appeared in …

A Realistic Modeling Of Fluid Infiltration In Thin Fibrous Sheets, Sudhakar Jaganathan, Hooman Vahedi Tafreshi, Behnam Pourdeyhimi

Mechanical and Nuclear Engineering Publications

In this paper, a modeling study is presented to simulate the fluid infiltration in fibrous media. The Richards’ equation of two-phase flow in porous media is used here to model the fluid absorption in unsaturated/partially saturated fibrous thin sheets. The required consecutive equations, relative permeability, and capillary pressure as functions of medium’s saturation are obtained via fiber-level modeling and a long-column experiment, respectively. Our relative permeability calculations are based on solving the Stokes flow equations in partially saturated three-dimensional domains obtained by imaging the sheets’ microstructures. The Richards’ equation, together with the above consecutive correlations, is solved for fibrous media …

A Binary Method For Simple And Accurate Two-Dimensional Cursor Control From Eeg With Minimal Subject Training, Turan A. Kayagil, Ou Bai, Craig S. Henriquez, Peter Lin, Stephen J. Furlani, Sherry Vorbach, Mark Hallett

Biomedical Engineering Publications

Background

Brain-computer interfaces (BCI) use electroencephalography (EEG) to interpret user intention and control an output device accordingly. We describe a novel BCI method to use a signal from five EEG channels (comprising one primary channel with four additional channels used to calculate its Laplacian derivation) to provide two-dimensional (2-D) control of a cursor on a computer screen, with simple threshold-based binary classification of band power readings taken over pre-defined time windows during subject hand movement.

Methods

We tested the paradigm with four healthy subjects, none of whom had prior BCI experience. Each subject played a game wherein he or she …

Degradation In Inaln/Gan-Based Heterostructure Field Effect Transistors: Role Of Hot Phonons, J. H. Leach, C. Y. Zhu, M. Wu, X. Ni, X. Li, J. Xie, Ü. Özgür, Hadis Morkoç, J. Liberis, E. Šermukšnis, A. Matulionis, H. Cheng, Ç. Kurdak

Electrical and Computer Engineering Publications

We report on high electric field stress measurements at room temperature on InAlN/AlN/GaN heterostructure field effect transistor structures. The degradation rate as a function of the average electron density in the GaN channel (as determined by gated Hall bar measurements for the particular gate biases used), has a minimum for electron densities around 1×1013 cm−2, and tends to follow the hot phonon lifetime dependence on electron density. The observations are consistent with the buildup of hot longitudinal optical phonons and their ultrafast decay at about the same electron density in the GaN channel. In part because they have negligible group …

On Carrier Spillover In C- And M-Plane Ingan Light Emitting Diodes, J. Lee, X. Li, X. Ni, Ü. Özgür, Hadis Morkoç, T. Paskova, G. Mulholland, K. R. Evans

Electrical and Computer Engineering Publications

The internal quantum efficiency(IQE) and relative external quantum efficiency (EQE) in InGaNlight-emitting diodes(LEDs) emitting at 400 nm with and without electron blocking layers (EBLs) on c-plane GaN and m-plane GaN were investigated in order to shed some light on any effect of polarizationcharge induced field on efficiency killer carrier spillover. Without an EBL the EQE values suffered considerably (by 80%) for both orientations, which is clearly attributable to carrier spillover. Substantial carrier spillover in both polarities, therefore, suggests that the polarizationcharge is not the major factor in efficiency degradation observed, particularly at high injection levels. Furthermore, the m-plane variety with …

Epitaxial Growth Of (001)-Oriented Ba0.5sr0.5tio3 Thin Films On A-Plane Sapphire With An Mgo/Zno Bridge Layer, Bo Xiao, Hongrui Liu, Vitaliy Avrutin, Jacob H. Leach, Emmanuel Rowe, Huiyong Liu, Ü. Özgür, Hadis Morkoç, W. Chang, L.M. B. Allredge, S. W. Kirchoefer, J. M. Pond

Electrical and Computer Engineering Publications

High quality (001)-oriented Ba0.5Sr0.5TiO3 (BST) thin films have been grown on a-plane sapphire(112¯0) by rf magnetron sputtering using a double bridge layer consisting of (0001)-oriented ZnO (50 nm) and (001)-oriented MgO (10 nm) prepared by plasma-assisted molecular beam epitaxy. X-ray diffraction revealed the formation of three sets of in-plane BST domains, offset from one another by 30°, which is consistent with the in-plane symmetry of the MgO layer observed by in situ reflective high electron energy diffraction. The in-plane epitaxial relationship of BST, MgO, and ZnO has been determined to be BST [110]//MgO [110]//ZnO [112¯0] and BST [110]/MgO [110]//ZnO [11¯00]. …

Plasmon-Enhanced Heat Dissipation In Gan-Based Two-Dimensional Channels, A. Matulionis, J. Liberis, I. Matulioniene, M. Ramonas, E. Šermukšnis, J. H. Leach, M. Wu, X. Ni, X. Li, Hadis Morkoç

Electrical and Computer Engineering Publications

Decay of nonequilibrium longitudinal optical (LO) phonons is investigated at room temperature in two-dimensional electron gas channels confined in nearly lattice-matched InAlN/AlN/GaN structures. A nonmonotonous dependence of the LO-phonon lifetime on the supplied electric power is reported for the first time and explained in terms of plasmon–LO-phonon resonance tuned by applied bias at a fixed sheet density (8×1012 cm−2). The shortest lifetime of 30±15 fs is found at the power of 20±10 nW/electron.

Nonpolar M-Plane Gan On Patterned Si(112) Substrates By Metalorganic Chemical Vapor Deposition, X. Ni, M. Wu, J. Lee, X. Li, A. A. Baski, Ü. Özgür, Hadis Morkoç

Electrical and Computer Engineering Publications

The concept of nonpolar (11¯00) m-plane GaN on Si substrates has been demonstrated by initiating growth on the vertical (1¯1¯1) sidewalls of patterned Si(112) substrates using metalorganic chemical vapor deposition. The Si(112) substrates were wet-etched to expose {111} planes using stripe-patterned SiNx masks oriented along the [1¯10] direction. Only the vertical Si(1¯1¯1) sidewalls were allowed to participate in GaNgrowth by masking other Si{111} planes using SiO2, which led to m-plane GaNfilms.Growth initiating on the Si(1¯1¯1) planes normal to the surface was allowed to advance laterally and also vertically toward full coalescence. InGaN double heterostructure active layers grown on these m-GaN …

Nanoelectrospray Aerosols From Microporous Polymer Wick Sources, Gary C. Tepper, Royal Kessick

Electrical and Computer Engineering Publications

Nanoelectrospray aerosols were formed from microporous polymer wick sources. Current-voltage characteristics were measured as a function of solution electrical conductivity and surface tension and two distinct electrospray modes were observed. In the first mode, when the maximum capillary flow rate through the wick exceeds the electrospray flow rate, a single electrospray forms from a droplet at the end of the wick. In the second mode, when the maximum capillary flow rate is less than the electrospray flow rate, a multitude of microscopic nanoelectrospray sources are formed from within the surface of the wick tip.

Retraction: “Observation Of Numerous E2 Mode Phonon Replicas In The Room Temperature Photoluminescence Spectra Of Zno Nanowires: Evidence Of Strong Deformation Potential Electron-Phonon Coupling” [Appl. Phys. Lett.89, 143121 (2006)], S. Ramanathan, Supriyo Bandyopadhyay, L. K. Hussey, M. Muñoz

Electrical and Computer Engineering Publications

No abstract provided.

Effect Of Large Strain On Dielectric And Ferroelectric Properties Of Ba0.5sr0.5tio3 Thin Films, Bo Xiao, Vitaliy Avrutin, Hongrui Liu, Emmanuel Rowe, Jacob H. Leach, Xing Gu, Ü. Özgür, Hadis Morkoç, W. Chang, L. M.B. Alldredge, S. W. Kirchoefer, J. M. Pond

Electrical and Computer Engineering Publications

BaxSr1−xTiO3 is ideally suited as a tunable medium for radio frequency passive component. In this context we have studied the effect of biaxial strain on the dielectric and ferroelectricproperties of Ba0.5Sr0.5TiO3thin filmsgrown epitaxially on SrTiO3 (001) substrates. The lattice parameters of the films determined by high-resolution x-ray diffraction with the thickness varying from 160 to 1000 nm indicated large biaxial compressive strain which decreased from 2.54% to 1.14% with increasing film thickness. Temperature-dependent measurements of the dielectric constant in our strained Ba0.5Sr0.5TiO3thin films revealed a significant increase in the Curie temperature as the film thickness is below 500 nm. Enhanced …

Energy Relaxation Probed By Weak Antilocalization Measurements In Gan Heterostructures, H. Cheng, N. Biyikli, J. Xie, Ç. Kurdak, H. Morkoç

Electrical and Computer Engineering Publications

Energy relaxation and electron-phonon (e-p) interaction are investigated in wurtzite Al0.15Ga0.85N/AlN/GaN and Al0.83In0.17N/AlN/GaN heterostructures with polarization induced two-dimensional electron gases in the Bloch–Grüneisen regime. Weak antilocalization (WAL) and Shubnikov–de Haas measurements were performed on gated Hall bar structures at temperatures down to 0.3 K. We used WAL as a thermometer to measure the electron temperature Te as a function of the dc bias current. We found that the power dissipated per electron, Pe, was proportional to T4e due to piezoelectric acoustic phonon emission by hot electrons. We calculated Pe as a function of Te without any adjustable parameters for both …

Correlated Growth Of Organic Material Tris (8-Hydroxyquinoline) Aluminum (Alq3) And Its Relation To Optical Properties, Bhargava R. Kanchibotla, K. Garre, Deeder Aurongzeb

Electrical and Computer Engineering Publications

We report slow correlated growth mode in energetic cluster vapor deposited organic light emissive material tris(8-hydroxyquinoline) aluminum from 5 to 100 nm. Phase modulated atomic force microscopy shows very slow grain growth with thickness, with very small phase differences within the film.Fractal dimension calculated from correlation function shows growth process above 10 nm consistent with diffusion-limited aggregation. For low thickness (5 nm), photoluminescence measurement shows the emission peak is shifted by ∼0.4 eV toward lower wavelength.

Electron Drift Velocity In Lattice-Matched Alinn/Aln/Gan Channel At High Electric Fields, L. Ardaravičius, M. Ramonas, J. Liberis, O. Kiprijanovič, A. Matulionis, J. Xie, M. Wu, J. H. Leach, H. Morkoç

Electrical and Computer Engineering Publications

Hot-electron transport was probed by nanosecond-pulsed measurements for a nominally undoped two-dimensional channel confined in a nearly lattice-matched Al0.82In0.18N/AlN/GaN structure at room temperature. The electric field was applied parallel to the interface, the pulsed technique enabled minimization of Joule heating. No current saturation was reached at fields up to 180 kV/cm. The effect of the channel length on the current is considered. The electron drift velocity is deduced under the assumption of uniform electric field and field-independent electron density. The highest estimated drift velocity reaches ∼3.2×107 cm/s when the AlN spacer thickness is 1 nm. At high fields, a weak …

Creating Lakes From Open Pit Mines: Processes And Considerations, Emphasis On Northern Environments, Christopher H. Gammons, Les N. Harris, James M. Castro, Peter A. Cott, Bruce W. Hanna

Geological Engineering

Creating Lakes from Open Pit Mines: Processes and Considerations, Emphasis on Northern Environments. This document summarizes the literature of mining pit lakes (through 2007), with a particular focus on issues that are likely to be of special relevance to the creation and management of pit lakes in northern climates. Pit lakes are simply waterbodies formed by filling the open pit left upon the completion of mining operations with water. Like natural lakes, mining pit lakes display a huge diversity in each of these subject areas. However, pit lakes are young and therefore are typically in a non-equilibrium state with respect …

Engineering At San Jose State University, Winter 2009, San Jose State University, Charles W. Davidson College Of Engineering

Engineering at San Jose State University

No abstract provided.

Santa Clara Magazine, Volume 51 Number 3, Winter 2009, Santa Clara University

Santa Clara Magazine

18 - EVERYTHING IS ILLUMINATED By Christine Cole. For the first time since the invention of the printing press, artists have put quill pen to paper to hand-write-in calligraphy-the Bible in its entirety. The result is a wonder to behold. And available to readers and gazers at Santa Clara.

24 - HOLD THE LINE By David McKay Wilson. At Harlem's Frederick Douglass Academy, basketball coach Pat Mangan '84 has built a legendary program by making sure his players have their priorities straight. Family first. School second. Then hoops.

28 - LESSONS IN DIPLOMACY. By Sam Scott '96. How Bob LaMonte …

Development Of A Planarization Process For The Fabrication Of Iii-V On Silicon Esaki Diodes, Michael J. Barth

Journal of the Microelectronic Engineering Conference

Esaki diodes are tunnel diodes with a very abrupt and degenerately doped PN junction. This abrupt junction causes the conduction bands to overlap, thus allowing for tunneling when a small bias is applied. 111-V on silicon Esaki tunnel diodes offer higher performance at lower power supplies compared to silicon. A vertical mesa etch is used to isolate the Esaki devices from each other. The etch results in a significant undercut below the gold contact which can cause issues with electrical testing. When probed the gold contact can short to the substrate. The solution to this is the addition of a …

A Simulator For Euv Lithography Mirrors, Thiago S. Jota

Journal of the Microelectronic Engineering Conference

The design of a simulator for EUV lithography mirrors is presented. A method of computing the expected value of reflectance and transmittance in stratified absorbing media with rough interfaces, based on Jay Eastman’s matrix formalism for scattered fields, was developed. In addition, a proof of principle experiment confirmed process feasibility for EUV mirror research at RIT.

Fabrication And Characterization Of Solar Cells On P-Type Si And P/P+Epitaxial Si, Nathaniel Kane

Journal of the Microelectronic Engineering Conference

Solar cells were fabricated at the Semiconductor and Microsystems Fabrication Laboratory at Rochester Institute of Technology on two different substrates. Standard polished p-type Si and a substrate consisting of a 15 μm p-type epitaxial Si built on a p+ substrate Si wafer. In addition, on the epitaxial Si both diffusion and ion implantation were used for doping. Using both epitaxial Si and ion implantation created solar cells that outperformed the diffusion and p-type Si solar cells.

Band-Pass Saw Filters On 128 Rotated Y-Cut Black Lithium Niobate, Sean M. Dunphy

Journal of the Microelectronic Engineering Conference

128° rotated Y-cut Black Lithium Niobate is used as a substrate material for the creation of simple one pass SAW bandpass filters. Center frequencies between 100 and 300 MHz were designed with varying aperture widths and designed bandwidths. The S₂₁ measurements were made with Agilent Technologies E5071C, two port network analyzer, and were compared to theory. Without considering the effects of the asymmetric coplanar waveguides (ACPW) used to connect the ground-signal-ground probes to the device under test (DUT) the average distance between measured and theoretical data is 0.523dB, near the center frequency.