Engineering Commons^™

Time-Optimal Control Of Discrete-Time Systems With Known Waveform Disturbances, Jennifer Lynn Riffer

Master's Theses (2009 -)

In this thesis, a discrete-time observer based disturbance accommodation controller is designed that is capable of minimizing the effect of disturbances with known waveform in both the system state and measurement as fast as possible while also driving the state to zero. This control is achieved by designing a single control input to accommodate disturbances in both the system state and measurement. For controller design, the state and measurement equations are augmented, and a least squares minimization technique is used to find a control input that drives the system state and measurement to zero, guaranteeing deadbeat response. During the design …

A Mixed-Dimensionality Modeling Approach For Interaction Of Heterogeneous Steam Reforming Reactions And Heat Transfer, Jeroen Valensa

Master's Theses (2009 -)

Hydrogen is most often produced on an industrial scale by catalytic steam methane reforming, an equilibrium-limited, highly endothermic process requiring the substantial addition of heat at elevated temperatures. The extent of reaction, or conversion efficiency, of this process is known to be heat transfer limited. Scaling the industrial process equipment down to the size required for small, compact fuel cell systems has encountered difficulties due to increased heat losses at smaller scales. One promising approach to effectively scale down the reforming process is to coat the catalyst directly onto the heat exchange surfaces of an integrated reactor/heat exchanger. In this …

Development And Implementation Of Novel Bristle Tool For Surface Treatment Of Metallic Components, Piyush Khullar

Master's Theses (2009 -)

Despite advances in paints and coatings technology, protective coatings are prone to eventual corrosion, degradation and/or failure. Consequently, a corrosive layer will develop that can undermine the performance and integrity of structural components. Therefore, both the corrosive layer and defunct coating must be periodically removed, and an acceptable level of surface cleanliness and texture must be obtained prior to the reapplication of new paint. Currently, an array of processes and equipment are used for efficiently cleaning and conditioning metallic surfaces, such as grit blasting, needle guns, and a variety of non-woven and coated abrasive tools.

This research investigates the method …

Systems Identification Of Sensorimotor Control For Visually Guided Wrist Movements, Chintan Poladia

Master's Theses (2009 -)

The sensorimotor control system is a complicated system in which the neural controller uses the feedback information from sensory modalities (visual, proprioceptive, vestibular, auditory, etc.) to actuate the musculo-skeletal system in order to execute intended movements. It has been an ongoing research to decode this sensorimotor integration. The current study utilized a systems identification approach in conjunction with a one-degree-of-freedom robotic manipulandum to quantify (delays, noises, wrist dynamics and controller parameters) a simplified (linear time-invariant) model of sensorimotor control for visually guided wrist stabilization movements.

Four sensorimotor tasks were used to characterize the parameters of the sensorimotor control model. Open …

An Analytical Model For Transient Deformation Of Viscoelastically Coated Beams: Applications To Static-Mode Microcantilever Chemical Sensors, Stephen M. Heinrich, Michael J. Wenzel, Fabien Josse, Isabelle Dufour

Civil and Environmental Engineering Faculty Research and Publications

The problem governing the transient deformation of an elastic cantilever beam with viscoelastic coating, subjected to a time-dependent coating eigenstrain, is mathematically formulated. An analytical solution for an exponential eigenstrain history, exact within the context of beam theory, is obtained in terms of the coating and base layer thicknesses, the elastic modulus of the base material, the initial coating modulus, the coating relaxation percentage (0%–100%), and the time constants of the coating’s relaxation process and its eigenstrain history. Approximate formulas, valid for thin coatings, are derived as special cases to provide insight into system behavior. Main results include (1) the …

Functional Stability Of Transfemoral Amputee Gait Using The 3r80 And Total Knee 2000 Prosthetic Knee Units, M. Barbara Silver-Thorn, Christine L. Glaister

Biomedical Engineering Faculty Research and Publications

Prosthetic knee designs have become extremely sophisticated compared to early constant friction single axis mechanisms. Today, prosthetists and physicians have a wide variety of components to choose from for their transfemoral amputee patients. Unfortunately, there are little quantitative data comparing the performance of different types of prosthetic components, and prosthetic prescription is often based on empirical knowledge and experience, rather than objective comparison of prosthetic designs. This study used gait analysis to objectively evaluate the stability characteristics of two types of prosthetic knee designs, the polycentric Total Knee 2000 (Ossur, Aliso Viejo, CA) and the single axis 3R80 stance control …

Preliminary Feasibility Of Dedicated Breast Ct With An Inverse Geometry, Taly Gilat-Schmidt

Biomedical Engineering Faculty Research and Publications

In this study we theoretically investigated the minimum scan time of an inverse-geometry dedicated breast CT system that provides sufficient sampling and dose equivalent to mammography without exceeding the limits of source power or detector count rate. The inverse geometry, which utilizes a large-area scanned source and a narrower photon-counting detector, is expected to have improved dose efficiency compared to cone-beam methods due to reduced scatter effects and improved detector efficiency. The analysis assumed the specifications of available inverse-geometry source and detector hardware (SBDX, NovaRay, Inc, Newark CA). The scan time was calculated for a 10, 14, and 18-cm diameter …

A Pilot Study Evaluating Use Of A Computer-Assisted Neurorehabilitation Platform For Upper-Extremity Stroke Assessment, Xin Feng, Jack Winters

Electrical and Computer Engineering Faculty Research and Publications

Background

There is a need to develop cost-effective, sensitive stroke assessment instruments. One approach is examining kinematic measures derived from goal-directed tasks, which can potentially be sensitive to the subtle changes in the stroke rehabilitation process. This paper presents the findings from a pilot study that uses a computer-assisted neurorehabilitation platform, interfaced with a conventional force-reflecting joystick, to examine the assessment capability of the system by various types of goal-directed tasks.

Methods

Both stroke subjects with hemiparesis and able-bodied subjects used the force-reflecting joystick to complete a suite of goal-directed tasks under various task settings. Kinematic metrics, developed for specific …

Mathematical Models For Natural Gas Forecasting, Steven Vitullo, Ronald H. Brown, George F. Corliss, Brian M. Marx

Electrical and Computer Engineering Faculty Research and Publications

It is vital for natural gas Local Distribution Companies (LDCs) to forecast their customers' natural gas demand accurately. A significant error on a single very cold day can cost the customers of the LDC millions of dollars. This paper looks at the financial implication of forecasting natural gas, the nature of natural gas forecasting, the factors that impact natural gas consumption, and describes a survey of mathematical techniques and practices used to model natural gas demand. Many of the techniques used in this paper currently are implemented in a software GasDay^TM, which is currently used by 24 LDCs …

Fatigue Risks In The Connections Of Sign Support Structures: Phase 1, Christopher Foley, Baolin Wan, Mathew Weglarz, Matthew Hellenthal, Jordan Komp, Andrew Smith, Joseph Schmidt

Transportation Reports with the Wisconsin Department of Transportation

Wisconsin sought to assess the risk of fatigue-induced fracture in its existing sign support structures designed before the latest AASHTO specifications that included fatigue design. A framework for assessing fatigue-induced fracture risk is developed and detailed synthesis of fatigue testing of connections is conducted. Statistical analysis of tests conducted since 1970 is made and models for characterizing uncertainty in the fatigue life of these connections are proposed. Recommendations regarding further fatigue testing (specimen configuration, number and stress range) are given. Statistical models for wind speed and direction are developed using historical records obtained through the National Climatic Data Center for …

A Device For Noninvasive Assessment Of Vascular Impairment Risk In The Lower Extremity, Michael J. Hoffmann, Paul E. Knudson, M. Barbara Silver-Thorn

Biomedical Engineering Faculty Research and Publications

The repeatability and resolution of the clinical gold standard of vascular assessment, the ankle-brachial index (ABI), was compared to that of a new device that dynamically assesses tissue perfusion during external loading utilizing laser Doppler flowmetry. Eight subjects of varying levels of vascular impairment were tested in successive weeks using two different sites on the subject's posterior calf. These new measures included the perfusion decrease as well as the unloading delay during cyclic loading. Some new dynamic tissue perfusion measures demonstrated comparable levels of reproducibility with the ABI (e.g., 10%-20%). Only the unloading delay showed potentially enhanced resolution over ABI …

A Reconfigurable Motor For Experimental Emulation Of Stator Winding Inter-Turn And Broken Bar Faults In Polyphase Induction Machines (Journal Article), Chia-Chou Yeh, Gennadi Y. Sizov, Ahmed Sayed-Ahmed, Nabeel Demerdash, Richard J. Povinelli, Edwin E. Yaz, Dan M. Ionel

Electrical and Computer Engineering Faculty Research and Publications

The benefits and drawbacks of a 5-hp reconfigurable induction motor, which was designed for experimental emulation of stator winding interturn and broken rotor bar faults, are presented in this paper. It was perceived that this motor had the potential of quick and easy reconfiguration to produce the desired stator and rotor faults in a variety of different fault combinations. Hence, this motor was anticipated to make a useful test bed for evaluation of the efficacy of existing and new motor fault diagnostics techniques and not the study of insulation failure mechanisms. Accordingly, it was anticipated that this reconfigurable motor would …

Dependence Of The Performance Of Single Photon Avalanche Diodes On The Multiplication Region Width, David A. Ramirez, Majeed M. Hayat, Mark A. Itzler

Electrical and Computer Engineering Faculty Research and Publications

The dependence of the performance of separate-absorption-multiplication (SAM) single-photon avalanche diodes (SPADs) on the width of the multiplication region is theoretically investigated. The theory is applied to SAM SPADs with InP homojunction multiplication regions and InAlAs-InP heterojunction multiplication regions. In both cases the absorber layer is InGaAs. Two scenarios for the dark counts are considered: (i) low-temperature operation, when the number of dark carriers is dominated by field-assisted mechanisms of band-to-band tunneling and tunneling through defects; and (ii) room-temperature operation, when the number of dark carriers in the multiplication region is dominated by the generation/recombination mechanism. The analysis utilizes a …

Minimum Mean-Squared Error Estimation Of Mel-Frequency Cepstral Coefficients Using A Novel Distortion Model, Kevin M. Indrebo, Richard J. Povinelli, Michael T. Johnson

Electrical and Computer Engineering Faculty Research and Publications

In this paper, a new method for statistical estimation of Mel-frequency cepstral coefficients (MFCCs) in noisy speech signals is proposed. Previous research has shown that model-based feature domain enhancement of speech signals for use in robust speech recognition can improve recognition accuracy significantly. These methods, which typically work in the log spectral or cepstral domain, must face the high complexity of distortion models caused by the nonlinear interaction of speech and noise in these domains. In this paper, an additive cepstral distortion model (ACDM) is developed, and used with a minimum mean-squared error (MMSE) estimator for recovery of MFCC features …

Canonical Correlation Feature Selection For Sensors With Overlapping Bands: Theory And Application, Biliana S. Paskaleva, Majeed M. Hayat, Zhipeng Wang, J. Scott Tyo, Sanjay Krishna

Electrical and Computer Engineering Faculty Research and Publications

The main focus of this paper is a rigorous development and validation of a novel canonical correlation feature- selection (CCFS) algorithm that is particularly well suited for spectral sensors with overlapping and noisy bands. The proposed approach combines a generalized canonical correlation analysis framework and a minimum mean-square-error criterion for the selection of feature subspaces. The latter induces ranking of the best linear combinations of the noisy overlapping bands and, in doing so, guarantees a minimal generalized distance between the centers of classes and their respective reconstructions in the space spanned by sensor bands. To demonstrate the efficacy and the …

Treatability Of U.S. Environmental Protection Agency Contaminant Candidate List Viruses: Removal Of Coxsackievirus And Echovirus Using Enhanced Coagulation, Brooke K. Mayer, Hodon Ryu, Morteza Abbaszadegan

Civil and Environmental Engineering Faculty Research and Publications

Enhanced coagulation was evaluated for removal efficacy of coxsackievirus and echovirus (Contaminant Candidate List [CCL] enteroviruses), poliovirus, four potential surrogate bacteriophages, and dissolved organic carbon (DOC). Viruses and DOC were effectively removed using enhanced coagulation, with removals generally improving as dose increased and pH decreased. Optimal enhanced coagulation conditions of 40 mg/L FeCl₃ and pH between 5 and 6.5 resulted in a maximum removal of 3.0 logs of coxsackievirus B6, 1.75 logs of echovirus 12, 2.5 logs of poliovirus 1, 1.8 logs of fr, 1.3 logs of phi-X174, 0.36 logs of MS2, 0.29 logs of PRD1, and 41% DOC. …

Inter-Frequency Bias Estimation For The Gps Monitor Station Network, Donny Holaschutz, Robert H. Bishop, R. Benjamin Harris, Brian Tolman

Mechanical Engineering Faculty Research and Publications

The inter-frequency bias (IFB) is present in all dual frequency combinations of GPS pseudorange and carrier phase observables. It is caused by the path dependent signal delays in both the satellite and receiver. That delay can be directly measured for a space vehicle prior to launch, or for a ground based receiver prior to its being used in the field. However the bias is known to drift, and monitoring the delay estimate by direct measurement is time consuming for ground based receivers and impossible for deployed space vehicles. Hansen (2002) examined the observability of IFB through a global model of …

Enhanced Na+/H+ Exchange During Ischemia And Reperfusion Impairs Mitochondrial Bioenergetics And Myocardial Function, Mohammed Aldakkak, David F. Stowe, James S. Heisner, Marisha Spence, Amadou K.S. Camara

Biomedical Engineering Faculty Research and Publications

Inhibition of Na+/H+ exchange (NHE) during ischemia reduces cardiac injury due to reduced reverse mode Na+/Ca2+ exchange. We hypothesized that activating NHE-1 at buffer pH 8 during ischemia increases mitochondrial oxidation, Ca2+ overload, and reactive O2 species (ROS) levels and worsens functional recovery in isolated hearts and that NHE inhibition reverses these effects. Guinea pig hearts were perfused with buffer at pH 7.4 (control) or pH 8 +/- NHE inhibitor eniporide for 10 minutes before and for 10 minutes after 35- minute ischemia and then for 110 minutes with pH 7.4 buffer alone. Mitochondrial NADH and FAD, [Ca2+], and superoxide …

The Power Flow Angle Of Acoustic Waves In Thin Piezoelectric Plates, Iren E. Kuznetsova, Boris D. Zaitsev, Andrei A. Teplykh, Shrinivas Joshi, Anastasia S. Kuznetsova

Electrical and Computer Engineering Faculty Research and Publications

The curves of slowness and power flow angle (PFA) of quasi-antisymmetric (A0) and quasi-symmetric (S0) Lamb waves as well as quasi-shear-horizontal (SH0) acoustic waves in thin plates of lithium niobate and potassium niobate of X-,Y-, and Z-cuts for various propagation directions and the influence of electrical shorting of one plate surface on these curves and PFA have been theoretically investigated. It has been found that the group velocity of such waves does not coincide with the phase velocity for the most directions of propagation. It has been also shown that S0 and SH0 wave are characterized by record high values …

Low-Flow Perfusion Of Guinea Pig Isolated Hearts With 26°C Air-Saturated Lifor Solution For 20 Hours Preserves Function And Metabolism, David F. Stowe, Amadou K.S. Camara, James S. Heisner, Mohammed Aldakkak, David R. Harder

Biomedical Engineering Faculty Research and Publications

Background

Donor human hearts cannot be preserved for >5 hours between explantation and recipient implantation. A better approach is needed to preserve transplantable hearts for longer periods, ideally at ambient conditions for transport. We tested whether Lifor solution could satisfactorily preserve guinea pig isolated hearts perfused at low flow with no added oxygen at room temperature for 20 hours.

Methods

Hearts were isolated from 18 guinea pigs and perfused initially with oxygenated Krebs–Ringer (KR) solution at 37°C. Hearts were then perfused with recirculated Lifor or cardioplegia (CP) solution (K⁺ 15 mmol/liter) equilibrated with room air at 20% of control …

Materials Characterization And Analysis Of The Marquette Interchange Hma Perpetual Pavement, James Crovetti, Hani Titi, Aaron Coenen, Mohammed Elias, R. Christopher Williams, Xinjun Li

Transportation Research Center: Marquette Interchange Instrumentation

This project focused on the characterization of materials used to construct the Hot Mix Asphalt (HMA) perpetual pavement within the Marquette Interchange and on the analysis of collected pavement response data to investigate the interactions between materials, environment, and traffic loadings. While these pavements are designed for a service life in excess of 50 years, to date there is insufficient field data to confirm this performance expectation. To help bridge this knowledge gap, this study included a mechanistic-empirical appraisal of the HMA perpetual pavement to provide predictions of key performance indicators over a fifty year service period. Laboratory testing was …

Generalized Model Of Resonant Polymer-Coated Microcantilevers In Viscous Liquid Media, Russell Cox, Fabien Josse, Michael J. Wenzel, Stephen M. Heinrich, Isabelle Dufour

Civil and Environmental Engineering Faculty Research and Publications

Expressions describing the resonant frequency and quality factor of a dynamically driven, polymer-coated microcantilever in a viscous liquid medium have been obtained. These generalized formulas are used to describe the effects the operational medium and the viscoelastic coating have on the device sensitivity when used in liquid-phase chemical sensing applications. Shifts in the resonant frequency are normally assumed proportional to the mass of sorbed analyte in the sensing layer. However, the expression for the frequency shift derived in this work indicates that the frequency shift is also dependent on changes in the sensing layer’s loss and storage moduli, changes in …

Distributed Object Tracking Using A Cluster-Based Kalman Filter In Wireless Camera Networks, Henry Medeiros, Johnny Park, Avinash Kak

Electrical and Computer Engineering Faculty Research and Publications

Local data aggregation is an effective means to save sensor node energy and prolong the lifespan of wireless sensor networks. However, when a sensor network is used to track moving objects, the task of local data aggregation in the network presents a new set of challenges, such as the necessity to estimate, usually in real time, the constantly changing state of the target based on information acquired by the nodes at different time instants. To address these issues, we propose a distributed object tracking system which employs a cluster-based Kalman filter in a network of wireless cameras. When a target …

Perceptually Motivated Wavelet Packet Transform For Bioacoustic Signal Enhancement, Yao Ren, Michael T. Johnson, Jidong Tao

Dr. Dolittle Project: A Framework for Classification and Understanding of Animal Vocalizations

A significant and often unavoidable problem in bioacoustic signal processing is the presence of background noise due to an adverse recording environment. This paper proposes a new bioacoustic signal enhancement technique which can be used on a wide range of species. The technique is based on a perceptually scaled wavelet packet decomposition using a species-specific Greenwood scale function. Spectral estimation techniques, similar to those used for human speech enhancement, are used for estimation of clean signal wavelet coefficients under an additive noise model. The new approach is compared to several other techniques, including basic bandpass filtering as well as classical …

Gender Determination Using Fingerprint Features, Jen-Feng Wang, Chen-Liang Lin, Yung-Hsien Chang, Mark L. Nagurka, Chen-Wen Yen, Chinson Yeh

Mechanical Engineering Faculty Research and Publications

Several previous studies have investigated the gender difference of the fingerprint features. However, regarding to the statistical significance of such differences, inconsistent results have been obtained. To resolve this problem and to develop a method for gender determination, this work proposes and tests three fingertip features for gender determination. Fingerprints were obtained from 115 normal healthy adults comprised of 57 male and 58 female volunteers. All persons were born in Taiwan and were of Han nationality. The age range was18-35 years. The features of this study are ridge count, ridge density, and finger size, all three of which can easily …

Irradiation Of Varying Volumes Of Rat Lung To Same Mean Lung Dose: A Little To A Lot Or A Lot To A Little?, Vladimir A. Semenenko, Robert C. Molthen, Chunrong Li, Natalya V. Morrow, Rongshan Li, Swarajit N. Ghosh, Meetha Medhora, X. Allen Li

Biomedical Engineering Faculty Research and Publications

Purpose: To investigate whether irradiating small lung volumes with a large dose or irradiating large lung volumes with a small dose, given the same mean lung dose (MLD), has a different effect on pulmonary function in laboratory animals.

Methods and Materials: WAG/Rij/MCW male rats were exposed to single fractions of 300 kVp X-rays. Four treatments, in decreasing order of irradiated lung volume, were administered: (1) whole lung irradiation, (2) right lung irradiation, (3) left lung irradiation, and (4) irradiation of a small lung volume with four narrow beams. The irradiation times were chosen to accumulate the same MLD of 10, …

Resource-Constrained Load Balancing Controller For A Parallel Database, Z. Tang, J. Douglas Birdwell, J. Chiasson, Chaouki T. Abdallah, Majeed M. Hayat

Electrical and Computer Engineering Faculty Research and Publications

This brief documents experimental results using a deterministic dynamic nonlinear system for load balancing, previously reported by Tang et al. in a cluster of computer nodes used for parallel computations in the presence of time delays and resource constraints. While previous publications by the authors have provided theoretical analysis of this load-balancing strategy using an idealized model, and have documented experiments using a simulated database, experimental results using a complete database for DNA profiles are documented here. Evaluation of the proposed load-balancing strategy using an actual database was critical because of several characteristics of the database that cannot be accurately …

Marquette Interchange Perpetual Pavement Instrumentation Project - Phase Ii, Nicholas Hornyak, James Crovetti

Transportation Research Center: Marquette Interchange Instrumentation

This report presents findings from the second phase of the Marquette Interchange instrumentation project and focuses on the maintenance of data recordation systems, development of computer programs to analyze data, and development of data packages for redistribution. The product of this research is a set of data which includes dynamic pavement response due to live traffic, vehicle information (weight, class, length, et cetera), and environmental data for the test site. The tasks within this project were not oriented for findings regarding pavement performance, but important and helpful conclusions can be drawn for similar future projects. The recordation systems have been …

A Comparative Study For 2d And 3d Computer-Aided Diagnosis Methods For Solitary Pulmonary Nodules, Chinson Yeh, Jen-Feng Wang, Ming-Ting Wu, Chen-Wen Yen, Mark L. Nagurka, Chen-Liang Lin

Mechanical Engineering Faculty Research and Publications

Many computer-aided diagnosis (CAD) methods, including 2D and 3D approaches, have been proposed for solitary pulmonary nodules (SPNs). However, the detection and diagnosis of SPNs remain challenging in many clinical circumstances. One goal of this work is to investigate the relative diagnostic accuracy of 2D and 3D methods. An additional goal is to develop a two-stage approach that combines the simplicity of 2D and the accuracy of 3D methods. The experimental results show statistically significant differences between the diagnostic accuracy of 2D and 3D methods. The results also show that with a very minor drop in diagnostic performance the two-stage …

Bronchial Circulation Angiogenesis In The Rat Quantified With Spect And Micro-Ct, Christian Wieholt, David L. Roerig, John B. Gordon, Steven Thomas Haworth, Robert C. Molthen, Anne V. Clough

Biomedical Engineering Faculty Research and Publications

Introduction

As pulmonary artery obstruction results in proliferation of the bronchial circulation in a variety of species, we investigated this angiogenic response using single photon emission computed tomography (SPECT) and micro-CT.

Materials and methods

After surgical ligation of the left pulmonary artery of rats, they were imaged at 10, 20, or 40 days post-ligation. Before imaging, technetium-labeled macroaggregated albumin (^99mTc MAA) was injected into the aortic arch (IA) labeling the systemic circulation. SPECT/micro-CT imaging was performed, the image volumes were registered, and activity in the left lung via the bronchial circulation was used as a marker of bronchial …