Engineering Commons^™

Robust And Resilient Finite-Time Bounded Control Of Discrete-Time Uncertain Nonlinear Systems, Mohammad N. Elbsat, Edwin E. Yaz

Electrical and Computer Engineering Faculty Research and Publications

Finite-time state-feedback stabilization is addressed for a class of discrete-time nonlinear systems with conic-type nonlinearities, bounded feedback control gain perturbations, and additive disturbances. First, conditions for the existence of a robust and resilient linear state-feedback controller for this class of systems are derived. Then, using linear matrix inequality techniques, a solution for the controller gain and the maximum allowable bound on the gain perturbation is obtained. The developed controller is robust for all unknown nonlinearities lying in a known hypersphere with an uncertain center and all admissible disturbances. Moreover, it is resilient against any bounded perturbations that may alter the …

Developing A Model To Enhance Labor Productivity Using Bridge Construction Benchmark Data, Seonghoon Kim, Yong Bai

Civil and Environmental Engineering Faculty Research and Publications

The Labor Working Status Monitoring (LWSM) Model that incorporates the WRITE and the industry benchmark data was developed through the five steps to enhance labor productivity in bridge construction operations. The first step of the development process was to conduct a literature review, followed by the second step which was to develop the WRITE. During the development, the authors identified the necessary hardware and software for the WRITE and outlined a schematic to show the connection of major hardware components. The third step was to develop the LWSM Model for monitoring the on-site construction labor working status by comparing data …

Optical Imaging Of Lipopolysaccharide-Induced Oxidative Stress In Acute Lung Injury From Hyperoxia And Sepsis, Reyhaneh Sepehr, Said H. Audi, Sepideh Maleki, Kevin Staniszewski, Annie L. Eis, Girija G. Konduri, Mahsa Ranji

Biomedical Engineering Faculty Research and Publications

Reactive oxygen species (ROS) have been implicated in the pathogenesis of many acute and chronic pulmonary disorders such as acute lung injury (ALI) in adults and bronchopulmonary dysplasia (BPD) in premature infants. Bacterial infection and oxygen toxicity, which result in pulmonary vascular endothelial injury, contribute to impaired vascular growth and alveolar simplification seen in the lungs of premature infants with BPD. Hyperoxia induces ALI, reduces cell proliferation, causes DNA damage and promotes cell death by causing mitochondrial dysfunction. The objective of this study was to use an optical imaging technique to evaluate the variations in fluorescence intensities of the auto-fluorescent …

A Multi-Scale Approach To A Greater Understanding Of The Behavior Of Heterogeneous Materials Under Dynamic Loading, Andrew J. Van Vooren

Master's Theses (2009 -)

The penetration of granular materials is of interest to a variety of different fields, and is an active area of research. The objective of this project is to gain understanding of the dynamics of a projectile penetrating into a granular material. To do this, experiments were run and a numerical model was created.

A dart gun was used to accelerate an aluminum dart to velocities around 100 m/s, which then impacted a target tank filled with Ottawa sand. The dart flew along a view window, which allowed for a recording of the penetration event using a high speed camera. Pressure …

The Effects Of Separating Visual And Motor Workspaces On The Generalization Of Visuomotor Adaptation Across Movement Conditions, Yuming Lei

Master's Theses (2009 -)

Separating visual and proprioceptive information in terms of workspace locations during reaching movement has been shown to disturb transfer of visuomotor adaptation across the arms. Here, we investigated whether separating visual and motor workspaces would also disturb generalization of visuomotor adaptation across movement conditions within the same arm. In our behavioral study, subjects were divided into four experimental groups (plus three control groups). The first two groups adapted to a visual rotation under a "dissociation" condition in which the targets for reaching movement were presented in midline while their arm performed reaching movement laterally. Following that, they were tested in …

Investigating The Possible Sources Of Error Using The Method Of Moments To Solve A Dielectric Scattering Problem, Phillip D. Bishop

Master's Theses (2009 -)

In an electromagnetic scattering problem, an incoming electromagnetic wave interacts with an object. The object is typically located in some medium, such as free space. When this electromagnetic wave becomes incident upon the object, the wave scatters. The goal of this work is to analyze the scattered fields for three different incoming wave types: a plane wave, a monopole line source, and a multipole line source. Each source is incident on an infinitely long circular cylinder of lossless dielectric material. Each source has a unique scattering characteristic.

The volume equivalence principle is used to replace the object geometry with mathematically …

Flame Temperature Imaging Of A Low Nox Burner Via Laser Rayleigh Scattering, Nicholas A. Smith

Master's Theses (2009 -)

Federal and global legislation are requiring increasingly stringent emission regulation on household appliances and in particular water heater burners. Emissions like NOx (NO and NO2) are a growing concern due to their adverse health effects and contribution to tropospheric ozone, acid rain, and smog formation. As NOx is more closely controlled, appliance manufacturers are developing low emission burners for use in water heaters.

Flame temperature is strongly correlated to NOx production. Hence, characterizing flame temperatures in new burners is a key part of improving upon burners used today and the development of future burners. Temperature measurements applied to a new, …

An Fmri Study On Supra-Spinal Contributions To Upper And Lower Limb Motor Control, Shancheng Bao

Master's Theses (2009 -)

The differences in the neural mechanisms contributing to upper and lower extremity movement have not been fully elucidated, and this might be a factor that leads to the ineffectiveness of rehabilitation techniques for most stroke survivors. It is unclear whether therapies designed for upper extremities should also be used for the lower extremities, and vice versa. In this study, fMRI was used to examine the supraspinal control of UE and LE movement in both neurologically intact individuals and people with post-stroke hemiparesis. We compared the location, volume, and intensity of brain activity associated with upper and lower extremity pedaling and …

Triclosan Enriches For Dehalococcoides-Like Chloroflexi In Anaerobic Soil At Environmentally Relevant Concentrations, Patrick J. Mcnamara, Mark J. Krzmarzick

Civil and Environmental Engineering Faculty Research and Publications

Triclosan is an antimicrobial agent that is discharged to soils with land-applied wastewater biosolids, is persistent under anaerobic conditions, and yet its impact on anaerobic microbial communities in soils is largely unknown. We hypothesized that triclosan enriches for Dehalococcoides-like Chloroflexi because these bacteria respire organochlorides and are likely less sensitive, relative to other bacteria, to the antimicrobial effects of triclosan. Triplicate anaerobic soil microcosms were seeded with agricultural soil, which was not previously exposed to triclosan, and were amended with 1 mg kg⁻¹ of triclosan. Triplicate control microcosms did not receive triclosan, and the experiment was run for …

Resonant Characteristics Of Rectangular Hammerhead Microcantilevers Vibrating Laterally In Viscous Liquid Media, Jinjin Zhang, Fabien Josse, Stephen M. Heinrich, Nicholas J. Nigro, Isabelle Dufour, Oliver Brand

Civil and Environmental Engineering Faculty Research and Publications

The resonant characteristics of laterally vibrating rectangular hammerhead microcantilevers in viscous liquid media are investigated. The rectangular hammerhead microcantilever is modeled as an Euler-Bernoulli beam (stem) and a rigid body (head). A modified semi-analytical expression for the hydrodynamic function in terms of the Reynolds number, Re, and aspect ratio, h/b, is proposed to rapidly evaluate the sensing characteristics. Using this expression, the resonance frequency, quality factor and normalized surface mass sensitivity are investigated as a function of the dimensions of the microcantilever and liquid properties. Guidelines for design of hammerhead microcantilever geometry are proposed to achieve efficient sensing platforms for …

Distributed Multichannel Speech Enhancement Based On Perceptually-Motivated Bayesian Estimators Of The Spectral Amplitude, Marek B. Trawicki, Michael T. Johnson

Electrical and Computer Engineering Faculty Research and Publications

In this study, the authors propose multichannel weighted Euclidean (WE) and weighted cosh (WCOSH) cost function estimators for speech enhancement in the distributed microphone scenario. The goal of the work is to illustrate the advantages of utilising additional microphones and modified cost functions for improving signal-to-noise ratio (SNR) and segmental SNR (SSNR) along with log-likelihood ratio (LLR) and perceptual evaluation of speech quality (PESQ) objective metrics over the corresponding single-channel baseline estimators. As with their single-channel counterparts, the perceptually-motivated multichannel WE and WCOSH estimators are functions of a weighting law parameter, which influences attention of the noisy spectral amplitude through …

Extra-Matrix Mg2+ Limits Ca2+ Uptake And Modulates Ca2+ Uptake-Independent Respiration And Redox State In Cardiac Isolated Mitochondria, Age D. Boelens, Ranjan K. Pradhan, Christoph A. Blomeyer, Amadou K.S. Camara, Ranjan K. Dash, David F. Stowe

Biomedical Engineering Faculty Research and Publications

Cardiac mitochondrial matrix (m) free Ca²⁺ ([Ca²⁺]_m) increases primarily by Ca²⁺ uptake through the Ca²⁺ uniporter (CU). Ca²⁺ uptake via the CU is attenuated by extra-matrix (e) Mg²⁺ ([Mg²⁺]_e). How [Ca²⁺]_m is dynamically modulated by interacting physiological levels of [Ca²⁺]_e and [Mg²⁺]_e and how this interaction alters bioenergetics are not well understood. We postulated that as [Mg²⁺]_e modulates Ca²⁺ uptake via the CU, it also alters bioenergetics in a matrix Ca²⁺–induced and …

North American Consortium On Rehabilitation Engineering And Technology For The Individual (Nareti), M. Barbara Silver-Thorn Phd, Karla Bustamante

Biomedical Engineering Faculty Research and Publications

No abstract provided.

Starting A Construction Engineering Program At Marquette University, Mark O. Federle

Civil and Environmental Engineering Faculty Research and Publications

Marquette University decided to start a Construction Engineering and Management program during the 2007 academic year. An endowed chair, titled the McShane Chair in Construction Engineering and Management, was funded by Jim and Kelly McShane to run the program. After a national search, Mark Federle, an executive with a large construction firm and previous academic experience at Iowa State University, was hired to start the program. The first class of students were enrolled in the fall of 2008. This paper will present the opportunities/challenges in starting a Construction Engineering and Management program. Lessons learned, comparisons to other programs, and other …

Conserved Extracellular Cysteines Differentially Regulate The Potentiation Produced By Zn2+ In Rat P2x4 Receptors, Chao-Ying Li, Ke-Ming Xiong, Yu-Xiang Wu, Yu-Wei Liu, Lin Chen, Randall B. Stewart, Robert Peoples, Chu-Li Yi

Biomedical Sciences Faculty Research and Publications

One feature of the amino acid sequence of P2X receptors identified from mammalian species, Xenopus laevis and zebrafish is the conservation of ten cysteines in the extracellular loop. Little information is available about the role of these conserved ectodomain cysteines in the function of P2X receptors. Here, we investigated the possibility that ten conserved cysteine residues in the extracellular loop of the rat P2X4 receptor may regulate zinc potentiation of the receptor using a series of individual cysteine to alanine point mutations and functional characterization of recombinant receptors expressed in Xenopus oocytes. For the C116A, C132A, C159A, C165A, C217A and …

A Novel Batch-Processing Method For Accurate Crystallographic Axis Alignment, Jun Hyun Han, Shankar Radhakrishnan, Chung-Hoon Lee

Electrical and Computer Engineering Faculty Research and Publications

A new method for the accurate alignment of lithographically-defined patterns to the crystallographic axes of substrates is presented. We provide a lower (worst-case) limit of the achievable high aspect ratio using anisotropic wet chemical silicon etch for deep trenches. The method uses the fact that the intensity of light reflected from two sets of gratings, one on the photomask and the other on the substrate, is a sharp function of their relative angular misalignment. By using pre-etched gratings on the substrate formed by wet anisotropic etching, alignment accuracies better than 50 millidegrees with respect to silicon crystallographic axes have been …

Discrimination Of Photon- And Dark-Initiated Signals In Multiple Gain Stage Apd Photoreceivers, George M. Williams, David A. Ramirez, Majeed M. Hayat, Andrew S. Huntington

Electrical and Computer Engineering Faculty Research and Publications

We demonstrate the ability of linear mode single carrier multiplication (SCM) avalanche photodiode (APD)-based optical receivers to discriminate single-photon-initiated avalanche events from dark-current-initiated events. Because of their random spatial origin in discrete regions of the depletion region, in the SCM APD the dark-generated carriers multiply differently than the photon-generated carriers. This causes different count distributions and necessitates different statistical descriptions of the signal contributions from photon- and dark-originating impulse responses. To include dark carriers in the performance models of the SCM APD, we considered the influence of the spatial origin of the ionization chains on a receiver's noise performance over …

Using Micro-Raman Spectroscopy To Assess Mems Si/Sio2 Membranes Exhibiting Negative Spring Constant Behavior, Lavern A. Starman, Ronald A. Coutu Jr.

Electrical and Computer Engineering Faculty Research and Publications

We introduce a novel micro-mechanical structure that exhibits two regions of stable linear positive and negative stiffness. Springs, cantilevers, beams and any other geometry that display an increasing return force that is proportional to the displacement can be considered to have a “Hookean” positive spring constant, or stiffness. Less well known is the opposite characteristic of a reducing return force for a given deflection, or negative stiffness. Unfortunately many simple negative stiffness structures exhibit unstable buckling and require additional moving components during deflection to avoid deforming out of its useful shape. In Micro-Electro-Mechanical Systems (MEMS) devices, buckling caused by stress …

Brief Report: Visuo-Spatial Guidance Of Movement During Gesture Imitation And Mirror Drawing In Children With Autism Spectrum Disorders, Nicole M.G. Salowitz, Petra Eccarius, Audrey Meyer Carson, Kirsten A. Schohl, Sheryl Jayne Stevens, Amy Vaughan Van Hecke, Robert A. Scheidt

Biomedical Engineering Faculty Research and Publications

Thirteen autistic and 14 typically developing children (controls) imitated hand/arm gestures and performed mirror drawing; both tasks assessed ability to reorganize the relationship between spatial goals and the motor commands needed to acquire them. During imitation, children with autism were less accurate than controls in replicating hand shape, hand orientation, and number of constituent limb movements. During shape tracing, children with autism performed accurately with direct visual feedback, but when viewing their hand in a mirror, some children with autism generated fewer errors than controls whereas others performed much worse. Large mirror drawing errors correlated with hand orientation and hand …

Separation Of Visual And Motor Workspaces During Targeted Reaching Results In Limited Generalization Of Visuomotor Adaptation, Yuming Lei, Michelle J. Johnson, Jinsung Wang

Biomedical Engineering Faculty Research and Publications

Separating visual and proprioceptive information in terms of workspace locations during reaching movement has been shown to disturb transfer of visuomotor adaptation across the arms. Here, we investigated whether separating visual and motor workspaces would also disturb generalization of visuomotor adaptation across movement conditions within the same arm. Subjects were divided into four experimental groups (plus three control groups). The first two groups adapted to a visual rotation under a “dissociation” condition in which the targets for reaching movement were presented in midline while their arm performed reaching movement laterally. Following that, they were tested in an “association” condition in …

Wavelength Optimization For Quantitative Spectral Imaging Of Breast Tumor Margins, Justin Y. Lo, J. Quincy Brown, Sulochana Dhar, Bing Yu, Gregory M. Palmer, Nan M. Jokerst, Nirmala Ramanujam

Biomedical Engineering Faculty Research and Publications

A wavelength selection method that combines an inverse Monte Carlo model of reflectance and a genetic algorithm for global optimization was developed for the application of spectral imaging of breast tumor margins. The selection of wavelengths impacts system design in cost, size, and accuracy of tissue quantitation. The minimum number of wavelengths required for the accurate quantitation of tissue optical properties is 8, with diminishing gains for additional wavelengths. The resulting wavelength choices for the specific probe geometry used for the breast tumor margin spectral imaging application were tested in an independent pathology-confirmed ex vivo breast tissue data set and …

Surface Fluorescence Studies Of Tissue Mitochondrial Redox State In Isolated Perfused Rat Lungs, Kevin Staniszewski, Said H. Audi, Reyhaneh Sepehr, Elizabeth R. Jacobs, Mahsa Ranji

Biomedical Engineering Faculty Research and Publications

We designed a fiber-optic-based optoelectronic fluorometer to measure emitted fluorescence from the auto-fluorescent electron carriers NADH and FAD of the mitochondrial electron transport chain (ETC). The ratio of NADH to FAD is called the redox ratio (RR = NADH/FAD) and is an indicator of the oxidoreductive state of tissue. We evaluated the fluorometer by measuring the fluorescence intensities of NADH and FAD at the surface of isolated, perfused rat lungs. Alterations of lung mitochondrial metabolic state were achieved by the addition of rotenone (complex I inhibitor), potassium cyanide (KCN, complex IV inhibitor) and/or pentachlorophenol (PCP, uncoupler) into the perfusate recirculating …

Conditional Spectrum Computation Incorporating Multiple Causal Earthquakes And Ground‐Motion Prediction Models, Ting Lin, Stephen C. Harmsen, Jack W. Baker, Nicolas Luco

Civil and Environmental Engineering Faculty Research and Publications

The Conditional Spectrum (CS) is a target spectrum (with conditional mean and conditional standard deviation) that links seismic hazard information with ground motion selection for nonlinear dynamic analysis. Probabilistic seismic hazard analysis (PSHA) estimates the ground motion hazard by incorporating the aleatory uncertainties in all earthquake scenarios and resulting ground motions as well as the epistemic uncertainties in ground motion prediction models (GMPMs) and seismic source models. Typical CS calculations to date are produced for a single earthquake scenario using a single GMPM, but more precise use requires consideration of at least multiple causal earthquakes and multiple GMPMs that are …

Field Experience As The Centerpiece Of An Integrated Model For Stem Teacher Preparation, Leigh A. Van Den Kieboom, Jill Mcnew-Birren, Ellen Eckman, M. Barbara Silver-Thorn

Biomedical Engineering Faculty Research and Publications

The purpose of this study was to provide a descriptive account of one pathway for preparing high-quality STEM (science, technology, engineering, and mathematics) teachers for work in high-need urban schools. In this account, we discuss the supports that STEM majors need in learning how to think about the content that they know well, through an educational perspective that focuses on teaching and learning. We also describe the approach that we use that integrates content knowledge, pedagogical content knowledge, and three extensive teaching co-op experiences to facilitate the transition from successful STEM undergraduate students to effective teachers of STEM content. We …

Development Of The Chinese Construction Industry After The Cultural Revolution: Administration Framework, Economic Growth, And Market Structure, Yilei Huang, Yi Lan, Yong Bai

Civil and Environmental Engineering Faculty Research and Publications

This paper presents the results of an investigation on the development of the Chinese construction industry after the Cultural Revolution in terms of administration framework, economic growth, and market structure, with the consideration of Chinese currency inflation. The development was divided into three stages based on Chinese government policy changes on the construction industry. In each stage, the reform of administration framework was reviewed, and the market size and market structure in both the domestic and the international markets were analyzed. Value added and gross output value of domestic market, the number of contracts, contracting value, total turnover, and turnover …

Discrimination Of Individual Tigers (Panthera Tigris) From Long Distance Roars, An Ji, Michael T. Johnson, Edward J. Walsh, Joann Mcgee, Douglas L. Armstrong

Electrical and Computer Engineering Faculty Research and Publications

This paper investigates the extent of tiger (Panthera tigris) vocal individuality through both qualitative and quantitative approaches using long distance roars from six individual tigers at Omaha's Henry Doorly Zoo in Omaha, NE. The framework for comparison across individuals includes statistical and discriminant function analysis across whole vocalization measures and statistical pattern classification using a hidden Markov model (HMM) with frame-based spectral features comprised of Greenwood frequency cepstral coefficients. Individual discrimination accuracy is evaluated as a function of spectral model complexity, represented by the number of mixtures in the underlying Gaussian mixture model (GMM), and temporal model complexity, …

Mitochondrial Handling Of Excess Ca2+ Is Substrate-Dependent With Implications For Reactive Oxygen Species Generation, Mohammed Aldakkak, David F. Stowe, Ranjan K. Dash, Amadou K.S. Camara

Biomedical Engineering Faculty Research and Publications

The mitochondrial electron transport chain is the major source of reactive oxygen species (ROS) during cardiac ischemia. Several mechanisms modulate ROS production; one is mitochondrial Ca²⁺ uptake. Here we sought to elucidate the effects of extramitochondrial Ca²⁺ (e[Ca²⁺]) on ROS production (measured as H₂O₂ release) from complexes I and III. Mitochondria isolated from guinea pig hearts were preincubated with increasing concentrations of CaCl₂ and then energized with the complex I substrate Na⁺ pyruvate or the complex II substrate Na⁺ succinate. Mitochondrial H₂O₂ release rates were assessed after …

Multi-Gain-Stage Ingaas Avalanche Photodiode With Enhanced Gain And Reduced Excess Noise, George M. Williams, Madison Compton, David A. Ramirez, Majeed M. Hayat, Andrew S. Huntington

Electrical and Computer Engineering Faculty Research and Publications

We report the design, fabrication, and test of an InGaAs avalanche photodiode (APD) for 950-1650 nm wavelength sensing applications. The APD is grown by molecular beam epitaxy on InP substrates from lattice-matched InGaAs and InAlAs alloys. Avalanche multiplication inside the APD occurs in a series of asymmetric gain stages whose layer ordering acts to enhance the rate of electron-initiated impact ionization and to suppress the rate of hole-initiated ionization when operated at low gain. The multiplication stages are cascaded in series, interposed with carrier relaxation layers in which the electric field is low, preventing avalanche feedback between stages. These measures …

Fatigue Risks In The Connections Of Sign Support Structures, Christopher M. Foley, Joseph A. Diekfuss, Baolin Wan

Transportation Reports with the Wisconsin Department of Transportation

This research effort develops a reliability-based approach for prescribing inspection intervals for mast-arm sign support structures corresponding to user-specified levels of fatigue-induced fracture risk. The resulting level of risk for a particular structure is dependent upon its geographical location, the type of connection it contains, the orientation of its mast-arm relative to north and the number of years it has been in service. The results of this research effort indicate that implementation of state-of-the-art reliability-based assessment procedures can contribute very valuable procedures for assigning inspection protocols (i.e. inspection intervals) that are based upon probabilities of finding fatigue-induced cracking in these …

Computational Fluid Dynamic Simulations For Determination Of Ventricular Workload In Aortic Arch Obstructions, Jessica S. Coogan, Frandics P. Chan, John F. Ladisa, Charles A. Taylor, Frank L. Hanley, Jeffrey A. Feinstein

Biomedical Engineering Faculty Research and Publications

Objective

The cardiac workload associated with various types of aortic obstruction was determined using computational fluid dynamic simulations.

Methods

Computed tomography image data were collected from 4 patients with 4 distinct types of aortic arch obstructions and 4 controls. The categorization of arch hypoplasia corresponded to the “A, B, C” nomenclature of arch interruption; a type “D” was added to represent diffuse arch hypoplasia. Measurements of the vessel diameter were compared against the normal measurements to determine the degree of narrowing. Three-dimensional models were created for each patient, and additional models were created for type A and B hypoplasia to …