Engineering Commons^™

Adaptive Critic Neural Network-Based Controller For Nonlinear Systems With Input Constraints, Pingan He, Sarangapani Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

A novel adaptive critic-Based multilayer neural network (NN) controller in discrete-time is designed to deliver a desired tracking performance for a class of nonlinear systems in the presence of magnitude constraints on the input. Reinforcement learning scheme in discrete time is proposed for the NN controller, where the action generating NN learning is performed based on a certain performance measure, which is supplied from a critic. using the Lyapunov approach and with a novel weight update, the uniform ultimately boundedness (UUB) of the closed loop tracking error and weight estimates are shown. the adaptive critic NN does not require an …

Mechanical Property Characterization Of Mouse Zona Pellucida, Yu Sun, Kai-Tak Wan, K. P. Roberts, J. C. Bischof, B. J. Nelson

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Previous intracytoplasmic sperm injection (ICSI) studies have indicated significant variation in ICSI success rates among different species. In mouse ICSI, the zona pellucida (ZP) undergoes a "hardening" process at fertilization in order to prevent subsequent sperm from penetrating. There have been few studies investigating changes in the mechanical properties of mouse ZP post fertilization. To characterize mouse ZP mechanical properties and quantitate the mechanical property differences of the ZP before and after fertilization, a microelectromechanical systems-based multiaxis cellular force sensor has been developed. A microrobotic cell manipulation system employing the multiaxis cellular force sensor is used to conduct mouse ZP …

Nonlinear H Infinity Missile Longitudinal Autopilot Design With Θ-D Method, Ming Xin, S. N. Balakrishnan

Mechanical and Aerospace Engineering Faculty Research & Creative Works

In this paper, a new nonlinear control synthesis technique, the theta- D method, is employed to design a missile longitudinal autopilot. The θ-D technique yields suboptimal solutions to nonlinear optimal control problems in the sense that it provides approximate solution to the Hamilton-Jacobi-Bellman (HJB) equation. Semi-global asymptotic stability can be achieved by manipulating the perturbation terms which are added to the cost function in developing a series solution. Furthermore, this method can be used to provide an approximate closed-form solution to the state dependent Riccati equation. The particular θ-D methodology adopted in this paper is referred to as θ-D H …

Rate-Based End-To-End Congestion Control Of Multimedia Traffic In Packet Switched Networks, Mingsheng Peng, S. R. Subramanya, Jagannathan Sarangapani

Electrical and Computer Engineering Faculty Research & Creative Works

This paper proposes an explicit rate-based end-to-end congestion control mechanism to alleviate congestion of multimedia traffic in packet switched networks such as the Internet. The congestion is controlled by adjusting the transmission rates of the sources in response to the feedback information from destination such as the buffer occupancy, packet arrival rate and service rate at the outgoing link, so that a desired quality of service (QoS) can be met. The QoS is defined in terms of packet loss ratio, transmission delay, power, and network utilization. Comparison studies demonstrate the effectiveness of the proposed scheme over New-Reno TCP (a variant …

Guideline Specifications For Construction And Maintenance Equipment For Street And Highway Work, Indiana Ltap

Indiana Local Technical Assistance Program (LTAP) Publications

The purpose of this guide is to provide a useful tool for county engineers and supervisors and city and town street commissioners in purchasing equipment.

Simplified Meta-Analysis Of Clinical Trials In Resuscitation, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Publications

Objective: To present and demonstrate a new simplified method for synthesizing results of multiple clinical trials in resuscitation research. Methods: The mean difference across studies in the proportion of favorable outcomes between experimental and control groups is calculated. This difference is shown to have a t-distribution. Its significance can be ascertained with a simple t-test. The analysis can be implemented in a one-page computer spreadsheet. Results: Simplified meta-analysis provides high sensitivity and can be extended to include weighting of studies according to size or quality, comparison of subgroups of studies, tests for outliers, and calculation of the power of the …

Interposed Abdominal Compression Cpr: A Comprehensive Evidence Based Review, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Publications

Interposed abdominal compression (IAC)-CPR includes all steps of standard external CPR with the addition of manual mid-abdominal compressions in counterpoint to the rhythm of chest compressions. IAC-CPR can increase blood flow during CPR about two fold compared to standard CPR without IAC, as shown by 6 of 6 studies in computer models and 19 of 20 studies in various animal models. The addition of IAC has clinical benefit in humans, as indicated in 10 of 12 small to medium sized clinical studies. The technique increases the frequency of immediate return of spontaneous circulation for in-hospital resuscitations from roughly 25% to …

A Simple Quantum Mechanical Treatment Of Scattering In Nanoscale Transistors, Rajesh Venugopal, Magnus Paulsson, Sebastien Goasguen, Supriyo Datta, Mark S. Lundstrom

Department of Electrical and Computer Engineering Faculty Publications

We present a computationally efficient, two-dimensional quantum mechanical simulation scheme for modeling dissipative electron transport in thin body, fully depleted, n-channel, silicon-on-insulator transistors. The simulation scheme, which solves the nonequilibrium Green’s function equations self consistently with Poisson’s equation, treats the effect of scattering using a simple approximation inspired by the “Büttiker probes,” often used in mesoscopic physics. It is based on an expansion of the active device Hamiltonian in decoupled mode space. Simulation results are used to highlight quantum effects, discuss the physics of scattering and to relate the quantum mechanical quantities used in our model to experimentally measured …

Quantum Mechanical Analysis Of Channel Access Geometry And Series Resistance In Nanoscale Transistors, R. Venugopal, S. Goasguen, Supriyo Datta, Mark S. Lundstrom

Department of Electrical and Computer Engineering Faculty Publications

We apply a two-dimensional quantum mechanical simulation scheme to study the effect of channel access geometries on device performance. This simulation scheme solves the nonequilibrium Green’s function equations self-consistently with Poisson’s equation and treats the effect of scattering using a simple approximation inspired by Büttiker. It is based on an expansion of the device Hamiltonian in coupled mode space. Simulation results are used to highlight quantum effects and discuss the importance of scattering when examining the transport properties of nanoscale transistors with differing channel access geometries. Additionally, an efficient domain decomposition scheme for evaluating the performance of nanoscale transistors is …

An Investigation On Transversely Prestressed Concrete Bridge Decks, J. A. Ramirez, Jhon Paul Smith

JTRP Technical Reports

This study is concerned with the development of design specifications for the use of transverse post-tensioning in concrete bridge decks. The ultimate goal behind this proposal is to improve the durability of concrete bridge superstructures. Experimental results from previous studies are used to validate the analytical models implemented in the development of the design specifications. It is found that the required distribution of transverse post-tensioning is such that different application levels of prestressing are required in regions containing the interior and exterior (or outermost) diaphragms. It is also concluded that the magnitude of such transverse forces is a function of …

Investigation Of Novel Acoustic Barrier Concepts Phase I: Concept Development And Preliminary Evaluation, Luc Mongeau, J. Stuart Bolton, Sanghoon Suh

JTRP Technical Reports

In a previous research project [SPR 2418; "Study of the performance of acoustic barriers for Indiana toll roads,"] the influence of environmental factors and of advanced sound barrier concepts was investigated. The presence of temperature gradients over pavements was found to have a strong influence on sound propagation. Refraction of sound waves emitted by tire-road interactions in the vicinity of the ground also affects sound barrier performance. Modified ray tracing model suggested that prevailing winds have an influence on barrier performance at large distances. Randomized edge configurations were found not to improve barrier performance for traffic noise. Random edges simply …

Maintenance Quality Assurance Program, Bob G. Mccullouch

JTRP Technical Reports

An INDOT maintenance QA program has been developed and implemented at the activity level. Every maintenance activity is checked and evaluated by QA guidelines. One area that has been considered as an ideal candidate for QA is at the management level of maintenance operations. This program uses a random sample population at a certain confidence level to evaluate the maintenance condition of INDOT roads. Five categories are evaluated: pavement, roadside features, shoulder, drainage, and traffic control. A field inspection program utilizes INDOT personnel and resources. A scoring program yields results that provides for category and individual item evaluations. Data collected …

Traffic Signals In School Zones, Kevin S. Lee, Darcy M. Bullock

JTRP Technical Reports

Traffic signals are used to control the right of way at intersections. Strict engineering guidelines are published in the Manual on Uniform Traffic Control Devices (MUTCD) that engineers use to determine if a traffic signal is “warranted”. The warrants provide consistent national balance between mobility, safety, efficiency, and costs. However, signalized intersections are often viewed by the general public as safer then unsignalized intersections. This belief is often heightened when there are personal injuries and even higher when children are involved. Parents, city officials, and local interest groups often vigorously request the installation of a traffic signal. After these requests …

Weigh-In-Motion Data Checking And Imputation, Ting Wei, Jon D. Fricker

JTRP Technical Reports

There are about 46 weigh-in-motion (WIM) stations in Indiana. When operating properly, they provide valuable information on traffic volumes, vehicle classifications, and axle weights. Because there are great amounts of WIM data collected everyday, the quality of these data should be monitor without further delay. The first objective of this study is to develop effective and efficient methods to identify missing or erroneous WIM data. The second objective is to develop a data imputation method to update the missing or erroneous data. This report describes the WIM data checking process on both a monthly and a daily basis. The Weigh-In-Motion …

Feasibility Of Radiographic Absorptiometry Of The Mandible As An Osteoporosis Screening Method, Julie A. Skipper

Browse all Theses and Dissertations

The purpose of this work was to develop and evaluate single- and dual-energy radiographic absorptiometry (RA) for the measurement of mandibular bone mineral density (BMD), using standard dental equipment, that would allow for inexpensive and widespread osteoporosis screening. Accurately measured x-ray tube spectra are important for validating the simulations used in the design of the method. A constrained least-squares deconvolution technique for reducing the detector-induced blurring of the energy spectrum was developed. Application of this analytic correction to spectra acquired with a NaI-photomultiplier detector improved the measured data by 20-60%. Implementation of the screening method is accomplished by simultaneously acquiring …

Innovative Forced Response Analysis Method Applied To A Transonic Compressor, Timothy M. Hutton

Browse all Theses and Dissertations

A set of inlet guide vane (IGV) unsteady surface pressure measurements of a transonic compressor is presented. Using a flexible pressure sensor array, unsteady IGV suction-surface and pressure-surface pressures are acquired for six spanwise by five chordwise locations for various speed lines and throttle settings. Measurements from this sensor array are used to investigate unsteady vane/blade interaction aeromechanical forcing functions in a modern, highly loaded compressor stage. A significant effect is shown on the unsteady forced response of the IGV with changes in compressor operating point and IGV/rotor axial spacing for various span and chord locations. In particular, variations in …

Plastic Dissipation Energy In Mixed-Mode Fatigue Crack Growth On Ductile Bimaterial Interfaces, Jeremy S. Daily

Browse all Theses and Dissertations

A new theory of fatigue crack growth in ductile solids has recently been proposed based on the total plastic energy dissipation per cycle ahead of the crack. This and previous energy-based approaches in the literature suggest that the total plastic dissipation per cycle can be closely correlated with fatigue crack growth rates under Mode I loading. The goal of the current study is to extend the dissipated energy approach to steady-state crack growth under mixed-mode loading conditions, with application to cyclic delamination of ductile interfaces in layered materials. The total plastic dissipation per cycle is obtained by 2-D elastic-plastic finite …

Bs News

Building Services Engineering

No abstract provided.

Simplified Shear Design Of Prestressed Concrete Members, Robert J. Frosch, Tyler S. Wolf

JTRP Technical Reports

Design methods for the shear resistance of reinforced and prestressed concrete beams are based on empirical evidence. Due to different approaches in their development different equations are used to calculate the shear strength of reinforced and prestressed concrete. Recent research conducted by Tureyen has proposed a simplified shear model for reinforced concrete which is primarily based upon mechanics and corresponds well with a wide range of test results. The objective of this research was to determine the applicability of the shear model to prestressed concrete. The applicability of the shear model was evaluated by a comparison of its results with …

Use Of Modulus Of Rupture, Fatigue Resistance And Maturity In Determining Opening To Traffic Time For Concrete Pavements, J. Olek, Menashi D. Cohen, Charles F. Scholer, Deepak R. Mandrekar

JTRP Technical Reports

The main objective of this experimental and analytical research project was to develop maturity-based guidelines for early opening-to-traffic of concrete pavements in the state of Indiana. Currently, the Indiana Department of Transportation (INDOT) specifies that pavements can be opened to traffic when the concrete reaches the strength of at least 3.8 MPa (550 psi). During this study modulus of rupture (MOR) and maturity data were collected and strength gain characteristics were analyzed. Also, fatigue experiments were performed at different stress levels and ages. Based on the experimental results, modulus of rupture of concrete was correlated with corresponding fatigue life for …

Interaction Of Disparity And Accommodative Vergence, Michele Liu Kung

Theses

To fixate on a target that moves from far to near, changes in blur and disparity activate accommodation and disparity vergence. The goal of this study was to experimentally obtain eye movement data from four subjects, and analyze this data using through a new signal processing algorithm known as independent component analysis (ICA). Preliminary data suggest that three underlying neural subcomponents are present where the two components of disparity vergence initiate the movement and the accommodative portion is activated to facilitate the steady state portion of the response.

ICA was used as a blind source separation technique to analyze experimental …

Tcm Decoding Using Neural Networks, Edit J. Kaminsky, Nikhil Deshpande

Electrical Engineering Faculty Publications

This paper presents a neural decoder for trellis coded modulation (TCM) schemes. Decoding is performed with Radial Basis Function Networks and Multi-Layer Perceptrons. The neural decoder effectively implements an adaptive Viterbi algorithm for TCM which learns communication channel imperfections. The implementation and performance of the neural decoder for trellis encoded 16-QAM with amplitude imbalance are analyzed.

Breaking The Silicon Ceiling: Women In Engineering Freshmen Seminar, Aura Ganz, Susannah Howe, Vanessa Rivera, Yuechun Chu

Engineering: Faculty Publications

In this paper we describe a pilot study for freshmen women engineering students we launched at the College of Engineering at UMass Amherst in the fall of 2002. This pilot study, which targeted increased retention of women in engineering, was comprised of the following three main elements: a weekly seminar, use of Pocket PCs and a web-based information and exchange center. The students' feedback to our seminar was very positive. The students noted that the seminar allayed their fears and concerns about pursuing engineering, provided a (classroom and online) forum for networking with their peers and other women engineers. This …

The Bridge Of Roebling And Crane, Joseph T. Bockrath

Journal Articles

No abstract provided.

Processor Microarchitecture For Implementation Of Ephemeral State Processing Within Network Routers, Muthulakshmi Muthukumarasamy

Theses and Dissertations--Electrical and Computer Engineering

The evolving concept of Ephemeral State Processing (ESP) is overviewed. ESP allows development of new scalable end-to-end network user services. An evolving macro-level language is being developed to support ESP at the network node level. Three approaches for implementing ESP services at network routers can be considered. One approach is to use the existing processing capability within commercially available network routers. Another approach is to add a small scale existing ASIC based general-purpose processor to an existing network router. This thesis research concentrates on a third approach of developing a special-purpose programmable Ephemeral State Processor (ESPR) Instruction Set Architecture (ISA) …

Discrete-Event Simulation: Simulation Practices And Trends, Paul Savory

Department of Industrial and Management Systems Engineering: Presentations

Discrete-event computer simulation is one of industry’s most used operations research techniques. Its uses range from answering questions about work-in-process and production feasibility to comparing alternative plans for system routing and scheduling. This presentation offers a brief overview of practices and trends.

Optimization Model Estimates Of Trunk Muscle Forces Do Not Correlate With Emg Activity Of Females As Well As Males, Mark L. Mcmulkin, Jeffrey C. Woldstad, Richard E. Hughes

Department of Industrial and Management Systems Engineering: Faculty Publications

Biomechanical optimization models are often used to estimate muscular and intervertebral disc forces during physical exertions. The purpose of this study was to determine whether an optimization-based biomechanical model predicts torso muscular activity of males and females equally well. The Minimum Intensity Compression (MIC) model, which has been extensively applied in industrial ergonomic task analysis, was used to estimate muscle forces for 3D moments. Participants (6 M, 6 F) performed 18 isometric exertions resisting 3D L3/L4 moments while electomyographic( EMG) activity was recorded for 8 muscles. Overall, model force estimates correlated better with male EMG activity (R² = …

A Shape-Based Approach To Change Detection Of Lakes Using Time Series Remote Sensing Images, Jiang Li, Ram M. Narayanan

Department of Electrical and Computer Engineering: Faculty Publications

Shape analysis has not been considered in remote sensing as extensively as in other pattern recognition applications. However, shapes such as those of geometric patterns in agriculture and irregular boundaries of lakes can be extracted from the remotely sensed imagery even at relatively coarse spatial resolutions. This paper presents a procedure for efficiently retrieving and representing shapes of interesting features in remotely sensed imagery using supervised classification, object recognition, parametric contour tracing, and proposed piecewise linear polygonal approximation techniques. In addition, shape similarity can be measured by means of a computationally efficient metric. The study was conducted on a time …

United States Patent Application Publication: Divide And Conquer System And Method Of Dna Sequence Assembly, Khalid Sayood, Hasan H. Otu

Department of Electrical and Computer Engineering: Faculty Publications

The present invention provides a new algorithm for assembling fragments from a long DNA sequence. The algorithm of the invention Solves simultaneously fragment assembly-related problems. Such as the fragment orientation, overlap and layout phases. This is achieved by clustering fragments with respect to their Average Mutual Information (AMI) profiles using the k-means algorithm.

Antenna Selection Scheme For Wireless Channels Utilizing Differential Space-Time Modulation, Le Chung Tran, Tadeusz A. Wysocki

Department of Electrical and Computer Engineering: Faculty Publications (to 2015)

In this paper, the authors prove that the differential space-time modulation techniques proposed in literature provide a full spatial diversity. Based on that, the authors propose an antenna selection scheme called general N-out-of-M antenna selection technique for wireless communications channels utilizing differential space-time modulation. The simulation shows that differential detection associated with our proposed technique provides much better bit error performance over that without antenna selection, and even over coherent detection without antenna selection at certain signal-to-noise ratios.